Anatomical Structures

Hip joint anatomy and morphological variations, focusing on the impact of version and coverage on FAI, dysplasia, and degenerative joint disease.

Overview

Anatomical reduction is not necessary for good function in slipped femoral epiphysis with severe displacement [1]. Patients treated conservatively can remain symptom-free for many years [1]. However, additional studies are needed to determine protective or adaptive factors in patients with abnormal hip anatomy who do not develop early osteoarthritis [2]. Further research is also required to determine whether joint-preserving hip surgery extends the life of the native hip joint [2].

Comprehensive knowledge of regional anatomy is essential for safe and effective aspiration and injection of the lower extremity [15]. Knowledge of procedural indications and appropriate techniques is equally essential for these procedures [15]. Surgical approaches to the hip joint and femur respect basic functional anatomy to afford adequate exposure and good results [6]. These approaches describe basic anatomical features, problems, and danger points to minimize complications [6].

Precise knowledge of anatomy can minimize complications in the direct anterior approach to the hip joint [70]. Clear goals in the surgical approach can facilitate visualization and instrumentation placement in this approach [70]. For anterior cruciate ligament reconstruction, thorough knowledge of anatomy is imperative to ensure optimal patient outcomes if cortical blowout occurs [20]. Knowledge of alternative fixation techniques is also imperative in this scenario [20].

Standard anterior, anterolateral, and posterolateral portals in hip arthroscopy allow proper accessibility of the central compartment [25]. These portals have slight limitations in the posteromedial corner [25]. The range of knee anatomy in patients scheduled for total knee arthroplasty is wide [71]. Proximal femoral osteotomies have different indications and treatment strategies in adolescents [24].

Localized acetabular bone density distributions are altered in unilateral femoral acetabular impingement [4]. Detailed density maps of bony anatomy may assist surgical providers in planning interventions for this condition [4]. The obturator neurovascular bundle has a high prevalence of 'venous corona mortis' in South Indian cadavers [3]. Individual evaluation of the obturator neurovascular bundle should be performed prior to surgical interventions [3]. Easily identifiable anatomic landmarks allow safe, reproducible physeal-sparing, anatomic anterior cruciate ligament reconstructions without intra-operative x-ray [23].

Anatomy & Pathophysiology

Biomechanics and Kinematics

Hip joint biomechanics are governed by both osseous and soft tissue constraints, which vary in importance depending on the direction of the applied force [35]. Healthy hips exhibit activity-dependent kinematics characterized by coordinated pelvic and femoral dynamic movements during weight-bearing activities [38]. The hip center of rotation trajectory under common movements highlights the critical role of hip translation in the physiologic range of motion [48]. Furthermore, the hip abductor moment arm varies substantially throughout the hip's range of motion in the coronal plane [42].

The distinctive phase-dependent biomechanical response of the hip demonstrates a coordinated control strategy for balance recovery due to gait perturbations [43]. Subject-specific gait combined with inverse dynamic analysis provides pre-processing parameters for finite element simulation, enabling more accurate biomechanical analysis of the hip joint [39]. A six degree-of-freedom robot is appropriate to reproduce the physiological range of motion of the hip joint [47].

Pathophysiology and Clinical Implications

Degenerative hips experience more abnormal hip kinematics that lead to higher articulating surface forces and stresses within the acetabulum compared to normal hips [44]. Abnormal hip kinematics in women with patellofemoral pain appears to be the result of diminished hip-muscle performance as opposed to altered femoral structure [45]. Increased stress and a shift in contact location were observed in simulated models of femoroacetabular impingement despite simulating lower degrees of hip flexion and internal rotation [51].

Abnormal hip and knee joint loading during walking after total hip replacement has a biomechanical background originating from hip geometry reconstruction [33]. Objective gait analysis failed to show a benefit of individualized reconstruction of the biomechanical hip geometry in customized femoral components for total hip arthroplasty [34]. Patients reported significant improvement in function and pain at 1 year postoperatively after arthroscopy for femoroacetabular impingement syndrome, but these improvements did not correlate with improvements in hip kinematics [49].

Soft Tissue and Capsular Considerations

The acetabular labrum bears a direct mechanical role during hip motion, and resecting the labrum might be detrimental for hip joint biomechanics by modifying strain distribution between the acetabulum and femur [40]. Capsular management during hip arthroscopy must allow for improved exposure without compromising stability and kinematics of the hip [7].

Assessment and Identification

An understanding of hip joint biomechanics allows clinicians to assimilate the effects of motions and deformations resulting from forces acting on the joint to guide appropriate medical interventions [32]. Identifying biomechanical mechanisms that place young athletes at risk for hip injury enables anticipatory guidance and preventative strategies [36]. A normative database of hip and knee kinematics utilized by football athletes was developed [41]. Smartphone applications are practical measurements for hip rotational angles when compared with three-dimensional motion analysis [50].

Classification

Obturator Neurovascular Bundle: Individual evaluation of the obturator neurovascular bundle, specifically the high prevalence of venous corona mortis, should be performed prior to surgical interventions [3].

Medial Knee Anatomy: The medial knee exhibits a consistent three-layered anatomical pattern [5]. Specific nomenclature for the superficial medial ligament and posteromedial capsule is suggested over the term 'posterior oblique ligament' based on this consistent three-layered anatomical pattern [5].

Psoas Valley: The psoas valley is a consistent bony landmark [11].

Femoral Torsion vs. Anteversion: Accurate anatomic localization enables precise terminology distinguishing femoral torsion from anteversion [18].

Hip Deformity (THA): A classification system enabled repeatable distinction of 5 types of architectural hip deformities in pre-operative templating for total hip arthroplasty [37].

Pes Anserinus Morphology: A proposed classification of pes anserinus morphology may improve the planning of surgical procedures [53].

Paediatric Hip Ultrasound: Geometric measurements in paediatric hip ultrasound are reliably interpreted and may be useful as a further measurement of quality [55]. Morphological features in paediatric hip ultrasound are generally poorly interpreted but improve with simpler binary classification [55].

Condylar-Stabilized TKA: A classification system developed for condylar-stabilized designs in total knee arthroplasty allows for appropriate grouping and comparison of distinct CS implants [57].

Medial Meniscus Ramp Tears: A surgically relevant classification system for medial meniscus ramp tears based on tear morphology allows for the evaluation of differing repair patterns and their effects on postoperative clinical outcomes [58].

Developmental Dysplasia of the Hip (DDH): A classification method for developmental dysplasia of the hip based on the greater trochanter of the femur could distinguish various types of DDH and aid in making surgical strategies [59].

Lower-Extremity Length Discrepancy: The classification of developmental patterns illustrates the varying directional changes that can occur in lower-extremity length discrepancies and their dependence on underlying biological phenomena [60].

Sourcil Types: Type II and III sourcil types account for the majority of cases, to which a modified approach to measuring the femoro-epiphyseal acetabular roof index is better suited [64]. The modified approach to measuring the femoro-epiphyseal acetabular roof index has better intraobserver and interobserver reliability compared with the original index [64].

Medial Patellofemoral Ligament (MPFL): The medial patellofemoral ligament (ME) demonstrates variable and elongated morphology, differentiating it from the adductor tubercle (AT) and Gerdy’s tubercle (GT), which demonstrated the most consistent morphology [65].

Other Considerations: Detailed density maps of bony anatomy may assist surgical providers in planning interventions for unilateral femoral acetabular impingement [4].

Clinical Presentation

A directed history and physical examination, combined with an understanding of normal and abnormal gait, facilitates the development of a differential diagnosis based on limp type, patient age, and likely anatomic site [12]. Concurrent hip and spine pathological processes present a substantial diagnostic challenge due to overlapping symptomatology, with no consensus on which condition to address first [52]. Extra-articular etiologies of hip pain can be accurately identified through physical examination and imaging [54].

Plain radiographic evaluation remains the initial diagnostic modality for femoroacetabular impingement [9]. Three-dimensional imaging such as MRI and CT is often obtained for the evaluation of labral and cartilage pathology, definition of bony anatomy, and surgical planning in femoroacetabular impingement [9]. Advanced imaging studies have enhanced understanding of hip vascular anatomy and its clinical implications for orthopaedic treatment [10].

Femoroacetabular impingement morphologic features and labral injuries are common in asymptomatic patients [14]. Both acetabular and femoral morphology are critical to understanding femoroacetabular impingement and developing patient-specific treatments [16]. The complex interplay of femoral and acetabular versions influences outcomes and the presence of asymptomatic lesions in femoroacetabular impingement [16]. The prevalence of morphological variations associated with femoroacetabular impingement varies according to age and sex in the general population [17]. Females with femoroacetabular impingement have more profound symptomatology and milder morphologic abnormalities [56]. Males with femoroacetabular impingement have a higher activity level, larger morphologic abnormalities, more common combined-type morphologies, and more extensive intra-articular disease [56].

A thorough appreciation of the anatomy of the abductor musculature, specific clinical signs, and imaging findings leads to appropriate diagnosis and management of lateral hip pain [46]. Extensive knowledge of hip anatomy and normal function is critical to identifying pathologies and developing successful treatment strategies [8]. The goal of treatment for hip disease in young, active patients is to establish a clear diagnosis, assess severity, and plan a surgical strategy to make the hip as structurally normal as possible [13].

Additional studies are needed to determine protective or adaptive factors in patients with abnormal hip anatomy who do not develop early osteoarthritis [2]. Additional studies are needed to determine whether joint-preserving hip surgery extends the life of the native hip joint [2].

Investigations

Plain radiography: Plain radiographic evaluation remains the initial diagnostic modality for femoroacetabular impingement [9].

MRI: Three-dimensional imaging such as MRI is often obtained for the evaluation of labral and cartilage pathology, definition of bony anatomy, and surgical planning in femoroacetabular impingement [9]. Advanced imaging studies have enhanced understanding of hip vascular anatomy and its clinical implications for orthopaedic treatment [10]. MRI scanning is necessary to establish whether some patients have an occult hip fracture [66]. Magnetic resonance imaging is effective in localizing neurilemoma of the saphenous nerve presenting as pain in the knee [74]. Pathologic changes seen on MRI were symptomatic in less than two thirds of elite female ballet dancers [82]. A novel hip MRI sequence provides consistent osseous morphology dimensions for FAI evaluation as CT imaging, but ioMRI cannot yet replace CT scans for thorough evaluation, though it may be considered when CT is contraindicated [83]. Magnetic resonance imaging-based 3-dimensional models of the pelvis and hip using machine learning for automatic bone segmentation in a dynamic hip impingement simulation are feasible with routine MRI and a short image acquisition time [63]. Patient-specific 3-dimensional MRI-based dynamic simulation of hip impingement and range of motion can replace 3-dimensional CT-based simulation for patients with femoroacetabular impingement for planning open hip preservation surgery and hip arthroscopy [72]. Several consistent anatomical levels were identified for single axial MR slice to facilitate muscle size and fatty infiltration measures at the hip, providing the basis for reliable and accurate data synthesis and improvements in the validity of future between studies analyses [61]. Measurements of femoral version on CT strongly correlated with those on MRI in adolescent patients [87].

CT: Computed tomography provides a noninvasive method for studying anatomy in live subjects, allowing for the detailed mapping of position, size, and orientation of the abductor muscles of the hip [79]. CT has higher interobserver reliability than MRI for measuring femoral anteversion [62]. Low-radiation dose 3-dimensional computed tomography scan reconstruction is the best way to visualize the anterior inferior iliac spine for now, as standard MRI scans cannot replicate the appropriate level of detail for AIIS morphology classification compared to 3D CT [68]. Preoperative planning CT scans should not be eliminated from the patient pathway, although future refinements in 3D MRI techniques may eventually allow them to replace low-dose 3D CT scans [68].

Other Considerations: Extensive knowledge of anatomy and normal function of the hip is critical to identifying pathologies and developing successful treatment strategies [8]. Accurate anatomic localization enables precise terminology distinguishing femoral torsion from anteversion [18]. Diagnosis of femoral anteversion should not rely exclusively on either physical examination or radiologic criteria [62]. Imaging for osteonecrosis is recommended in athletes with hip dislocation and subluxation, with evidence suggesting 4- to 6-week magnetic resonance imaging and follow-up at 3 months for those with suspicious findings in the femoral head [75]. MRI documentation should be established as a standard examination post-reduction for congenital dislocation of the hip [69].

Treatment

Non-Operative

Non-surgical management is the primary approach for many hip and knee pathologies. Most patients with peritrochanteric space disorders or lateral hip pain resolve symptoms with non-surgical management in the mid-term, but surgical options should be evaluated when non-surgical management fails [84]. Non-operative treatments for lower-extremity rotational problems in children are usually ineffective [97]. Non-operative management of proximal rectus femoris avulsion injuries is associated with highly variable periods of convalescence, poor return to preinjury level of function, and high risk of injury recurrence [93]. Operative management of fragility fractures of the pelvis should be considered for patients failing a brief period of non-operative management, although prospective randomised trials are needed to provide improved evidence [85].

Operative

Indications: Surgical treatment for osteochondritis dissecans following Legg-Calve-Perthes disease is indicated when bone fragments fail to heal and symptoms progress despite conservative treatment [27]. Surgical management of coxa vara in childhood is indicated for progressive, painful, unilateral deformity or leg-length discrepancy, while moderate nonprogressive deformity often does not require surgery [92]. Proximal femoral osteotomies in adolescents have various indications and treatment strategies [24]. Preoperative roentgenographic evaluation for osteotomies about the hip in children helps confirm adequacy of coverage and guides surgical decision-making, though exact criteria are not yet established [80]. In non-elite patients, persistent grade 2 or 3 medial collateral ligament laxity beyond 12 weeks in the setting of anterior cruciate ligament rupture should prompt combined anterior cruciate ligament reconstruction with medial collateral ligament repair and reconstruction [95].

Surgical Approach / Technique: Surgical approaches to the hip joint and femoral shaft should respect basic functional anatomy to ensure adequate exposure and good results while minimizing complications [6]. The anterior intrapelvic approach requires a comprehensive understanding of its historically 'nonorthopaedic' surgical anatomy and associated risks [29]. Standard anterior, anterolateral, and posterolateral portals in hip arthroscopy allow proper accessibility of the central compartment, with slight limitations in the posteromedial corner [25]. Capsular management during hip arthroscopy must allow for improved exposure without compromising hip stability and kinematics [7]. Capsular thickness and intra-substance changes of the anterior capsule vary in dysplastic hips, which could alter capsular management strategies [67]. Using easily identifiable anatomic landmarks allows for safe, reproducible physeal-sparing, anatomic anterior cruciate ligament reconstruction without the need for intra-operative x-ray [23]. Anatomical reduction is not necessary for good function in slipped femoral epiphysis with severe displacement, as the procedure allows patients to remain symptom-free for many years [1]. Individual evaluation of the obturator neurovascular bundle, including the high prevalence of venous corona mortis, should be performed prior to surgical interventions [3].

Implant Selection: Comprehensive knowledge of regional anatomy, procedural indications, and appropriate techniques is essential for safe and effective aspiration and injection of the lower extremity [15]. Thorough knowledge of anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes if cortical blowout occurs during anterior cruciate ligament reconstruction [20].

Alignment / Balancing Strategy: The goal of treatment for hip disease in young, active patients is to establish a clear diagnosis, assess severity, and plan a surgical strategy to make the hip as structurally normal as possible [13]. Both acetabular and femoral morphology are critical to understanding femoroacetabular impingement and developing patient-specific treatments, as the complex interplay of versions influences outcomes and the presence of asymptomatic lesions [16]. Surgical treatment limited to localized recontouring of the head-neck profile may fail to address significant components of the underlying abnormality in cam impinging femurs [73]. Anatomic anterolateral ligament reconstruction did not reduce anterolateral rotational laxity in biomechanical analysis [81].

Pain Management: Subchondroplasty for post-traumatic bone marrow lesions of the medial femoral condyle showed no difference in the progression of medial compartment post-traumatic gonarthrosis compared to controls, despite improvements in clinical outcomes and bony histology [77].

Adjuncts: Repair of horizontal cleavage meniscus tears results in substantial improvements in patient-reported outcomes, with acceptable midterm clinical healing rates and low reoperation/failure rates [76].

Other Considerations: When nonoperative treatment fails, patient-reported outcomes after operative management for soft tissue cam impingement in adolescents are comparable to those in patients with osseous cam lesions [88].

Complications

Infection (PJI): The provided evidence does not contain specific data regarding infection rates or management protocols for periprosthetic joint infection.

Aseptic loosening: Long-term follow-up is required to determine whether the excellent results of isolated polyethylene insert exchange for flexion instability after primary total knee arthroplasty are durable over time [28]. Anatomic femoral attachment is critical to a well-functioning medial patellofemoral ligament reconstruction and minimizes complications, while nonanatomic placement can cause significant changes in graft isometry [99].

Instability: FAI is defined as a pathologic mechanical process involving morphologic abnormalities and vigorous motion that damages soft-tissue structures [21]. FAI morphology predisposes to later osteoarthritis [21].

Periprosthetic fracture: Reconstruction of neglected developmental dysplasia by total hip arthroplasty with subtrochanteric shortening osteotomy is a demanding technique with a high rate of related complications [90].

Thromboembolism: The provided evidence does not contain specific data regarding thromboembolic events.

Patellar / Extensor-mechanism: Anatomic femoral attachment is critical to a well-functioning medial patellofemoral ligament reconstruction and minimizes complications, while nonanatomic placement can cause significant changes in graft isometry [99].

Stiffness / Arthrofibrosis: Functional deficits persist due to soft tissue damage from arthrosis requiring longer recovery time independent of the surgical approach (minimalinvasive vs transgluteal) for total hip arthroplasty [30].

Nerve palsy: Individual evaluation of the obturator neurovascular bundle, including the high prevalence of venous corona mortis, should be done prior to any surgical interventions to avoid this risky anatomical structure [3]. The use of medial hip arthroscopy portals did not cause any damage to the neurovascular structures evaluated [100].

Wound complications: The provided evidence does not contain specific data regarding wound healing complications.

Polyethylene wear: Although no detrimental clinical effect was found in this intermediate-term follow-up of cementless total hip replacement with a modular femoral head with an extended flange-reinforced neck, the findings warrant concern for adverse effects after more long-term follow-up [78].

Other Considerations: Anatomical reduction is not necessary for good function in slipped femoral epiphysis with severe displacement, and the procedure allows patients to remain symptom-free for many years [1]. Additional studies are needed to determine protective or adaptive factors in patients with abnormal anatomy who do not develop early osteoarthritis [2]. Additional studies are needed to determine whether joint preserving hip surgery extends the life of the native hip joint [2]. The study delineated a consistent three-layered anatomical pattern of the medial knee, suggesting the use of specific nomenclature for the superficial medial ligament and posteromedial capsule rather than the term 'posterior oblique ligament' [5]. Surgical approaches to the hip joint and femoral shaft describe basic anatomical features, problems, and danger points to ensure adequate exposure and good results while minimizing complications [6]. More long-term data are needed to define the natural history of pincer deformities and FAI in younger cohorts [21]. Long-term follow-up will be necessary to evaluate any differences in long-term durability between gap balancing and measured resection techniques in simultaneous bilateral total knee arthroplasty [19]. Femoral component coronal alignment may affect long-term clinical outcomes in fixed-bearing unicompartmental knee arthroplasty, but not short-term clinical outcomes nor 10-year survivorship [26]. The anterior intrapelvic approach review focuses on historically 'nonorthopaedic' surgical anatomy and associated risks [29]. Reconstruction of the original joint center with subtrochanteric femoral shortening for severe developmental dysplasia of the hip demonstrates good mid-term results [31]. Once anatomic reconstruction of the hip is achieved in neglected developmental dysplasia, patients have a remarkably good functional capacity and implant survival during long follow-up periods [90]. Porous implants are effective in tackling metaphyseal bone defects showing good survivorship outcome at midterm follow-up in revision arthroplasty of the knee with severe bone loss [98].

Recovery

Light activity (weeks): Functional recovery timelines vary significantly by procedure. In slipped femoral epiphysis, patients may remain symptom-free for many years without anatomical reduction [1]. For hip total endoprosthesis implantation, functional deficits persist due to soft tissue damage from arthrosis, requiring a longer recovery time independent of the surgical approach (minimally invasive vs transgluteal) [30].

Full activity (months): Long-term outcomes depend on specific surgical techniques and patient factors. In ACL reconstruction, a structured preoperative exercise program resulted in better postoperative functional outcomes at the long term [22]. Thigh muscle changes at long-term evaluation differ from early changes associated with ACL injury and reconstruction, suggesting treatment strategies may need adjustment to preserve long-term function [91]. For femoroacetabular impingement (FAI) surgery with residual bony prominence, clinical and functional results, activity, and quality of life improved statistically with an average follow-up time of 12 months [89].

Complete recovery / outcome plateau (months): Durability and natural history assessments extend beyond immediate postoperative periods. In fixed-bearing unicompartmental knee arthroplasty, femoral component coronal alignment may affect long-term clinical outcomes, but not short-term clinical outcomes nor 10-year survivorship [26]. Current evidence suggests modular bicompartmental knee arthroplasty provides comparable functional outcome to total knee arthroplasty at short-term to midterm follow-up, however, with poor long-term survivorship [94]. Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip demonstrates good mid-term results [31].

Rehabilitation protocol: Specific rehabilitation considerations include the need for further studies to determine if two-incision technique femoral tunnel placement in anterior cruciate ligament reconstruction can ameliorate proprioception as well as clinical outcome at a long-term follow-up [96]. Biomechanical and long-term clinical studies will continue to be performed to better understand the importance of the labrum and how to restore its function in labral base refixation [86].

Functional milestones: Prognosis is heavily influenced by age and anatomical characteristics. The natural history of Legg-Calvé-Perthes Disease is often favorable for children younger than 6 years and poor for children older than 8 to 10 years [102]. Specific morphological characteristics on pelvis radiographs of avascular necrosis hips were predictive for poor outcome at a very young age in developmental dysplasia of the hip [105]. Recognition of femoroacetabular impingement and early intervention before the degenerative process is advanced is likely to have a considerable impact on the natural history of the disease, delaying the onset of end-stage arthritis in young patients [101].

Other Considerations: Several areas require additional long-term data to define natural histories and durability. Additional studies are needed to determine protective or adaptive factors in patients with abnormal anatomy who do not develop early osteoarthritis [2]. Additional studies are needed to determine whether joint preserving hip surgery extends the life of the native hip joint [2]. More long-term data are needed to define the natural history of pincer deformities and femoroacetabular impingement (FAI) in younger cohorts [21]. Long-term follow-up is necessary to evaluate any differences in long-term durability between gap balancing and measured resection techniques in simultaneous bilateral total knee arthroplasty [19]. Longer-term follow-up is required to determine whether the excellent results of isolated polyethylene insert exchange for flexion instability after primary total knee arthroplasty are durable over time [28]. The study aimed to determine the long-term objective and subjective outcome of untreated articular cartilage defects observed at the time of ACL reconstruction [103]. Surgical treatment indications for osteochondritis dissecans following Legg-Calve-Perthes disease include failure of bone fragments to heal and progression of symptoms despite conservative treatment [27].

Key Evidence

• [L4] Additional studies are needed to determine protective or adaptive factors in patients with abnormal anatomy who do not develop early OA and to determine whether joint preserving hip surgery extends the life of the native hip joint. (10.5435/jaaos-d-16-00532)
• [Paper] Individual evaluation of this risky anatomical structure should be done prior to any surgical interventions. (10.1016/j.injury.2016.04.032)
• [L4] Providing detailed density maps of the bony anatomy may also assist surgical providers in planning interventions. (10.1177/2325967124s00187)
• [L5] The study delineated a consistent three-layered anatomical pattern of the medial knee, suggesting the use of specific nomenclature for the superficial medial ligament and posteromedial capsule rather than the term 'posterior oblique ligament'. (10.2106/00004623-197961010-00011)
• [L5] The management of the capsule is critical and must allow for improved exposure without compromising stability and kinematics of the hip. (10.1016/j.arthro.2011.08.288)
• [L5] Plain radiographic evaluation remains the initial diagnostic modality, while three-dimensional imaging such as MRI and CT is often obtained for the evaluation of labral and cartilage pathology, definition of bony anatomy, and surgical planning. (10.5435/00124635-201300001-00006)
• [L5] Advanced imaging studies have enhanced understanding of this vascular anatomy and its clinical implications for orthopaedic treatment. (10.5435/jaaos-d-15-00237)
• [L4] This review highlights the importance of the anatomy of the psoas valley which is a consistent bony landmark. (10.1186/s12891-020-03241-1)
• [L5] With an understanding of normal and abnormal gait, a directed history and physical examination, and the development of a differential diagnosis based on the type of limp, the patient's age, and the anatomic site that is most likely affected, the orthopaedist can take a selective approach to diagnostic testing. (10.5435/00124635-200103000-00003)
• [L5] The goal of treatment is to establish a clear diagnosis, assess severity, and plan a surgical strategy to make the hip as structurally normal as possible. (10.5435/00124635-200812000-00002)
• [L4] FAI morphologic features and labral injuries are common in asymptomatic patients. (10.1016/j.arthro.2014.11.042)
• [L5] Comprehensive knowledge of regional anatomy, procedural indications, and appropriate techniques are essential for safe and effective aspiration and injection. (10.5435/jaaos-d-16-00762)
• [L5] Both acetabular and femoral morphology are critical to understanding femoroacetabular impingement and developing patient-specific treatments, as the complex interplay of versions influences outcomes and the presence of asymptomatic lesions. (10.1016/j.arthro.2021.09.033)
• [L3] This study provides information to determine the prevalence of these anatomic variants in the general population. (10.1177/2325967120977892)
• [L4] Accurate anatomic localization enables precise terminology distinguishing femoral torsion from anteversion. (10.1007/s11999-014-4000-4)
• [L1] Long-term follow-up will be necessary to evaluate any differences in long-term durability. (10.1016/j.arth.2019.10.002)
• [L5] A thorough knowledge of the anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes if cortical blowout occurs despite careful planning and adherence to proper surgical technique. (10.1177/2325967116652122)
• [L5] FAI is defined as a pathologic mechanical process involving morphologic abnormalities and vigorous motion that damages soft-tissue structures; while FAI morphology is common in young adults and predisposes to later OA, more long-term data are needed to define the natural history of pincer deformities and FAI in younger cohorts. (10.5435/00124635-201300001-00004)
• [L2] A structured preoperative exercise program resulted in better post operative functional outcomes at the long term. (10.1016/j.arthro.2013.07.252)
• [L4] Using these easily identifiable landmarks allows safe, reproducible anatomic ACL reconstructions without the need for intra-operative x-ray. (10.1016/j.arthro.2011.03.072)
• [L4] The aim of this review is to show the different ways of proximal femoral osteotomies and their indications after having done a selective literature research. (10.1055/a-1023-4679)
• [L5] In hip arthroscopy, the use of the standard anterior, anterolateral, and posterolateral portals allows proper accessibility of the central compartment, with slight limitations in the posteromedial corner. (10.1016/j.arthro.2013.05.017)
• [L3] Femoral component coronal alignment may affect long-term clinical outcomes, but not short-term clinical outcomes nor 10-year survivorship. (10.1016/j.arth.2020.07.070)
• [L4] Longer-term follow-up is required to determine whether these results are durable over time. (10.1016/j.arth.2020.01.006)
• [L5] This review aims to provide an in-depth understanding of the AIP approach with a focus on the historically 'nonorthopaedic' surgical anatomy and associated risks. (10.5435/jaaos-d-24-01050)
• [L3] Functional deficits persist due to soft tissue damage from arthrosis requiring longer recovery time independent of the surgical approach. (10.1055/s-0030-1250590)
• [Paper] A reconstruction of the original joint center and good mid-term results are demonstrated. (10.1007/s00402-003-0554-4)
• [L5] An understanding of hip joint biomechanics constitutes an important background for the diagnosis and treatment of hip disorders, allowing clinicians to assimilate the effects of motions and deformations resulting from forces acting on the joint to guide appropriate medical interventions. (10.1016/j.arthro.2010.01.027)
• [L2] Abnormal hip and knee joint loading during walking after THR has a biomechanical background originating from hip geometry reconstruction. (10.1016/j.arth.2019.07.027)
• [L3] Despite the individualized reconstruction of the biomechanical hip geometry, objective gait analysis failed to show a benefit. (10.1007/s00402-008-0717-4)
• [L5] Both osseous and soft tissue constraints are important to hip biomechanics depending upon the direction of applied force. (10.1007/s00167-012-2255-4)
• [L3] Identifying biomechanical mechanisms that place young athletes at risk for hip injury enables anticipatory guidance and preventative strategies for these patients. (10.1177/2325967113s00059)
• [L4] The classification system enabled repeatable distinction of 5 types of architectural hip deformities. (10.1007/s00402-019-03298-1)
• [L4] This study revealed activity dependent kinematics of healthy hip joints with coordinated pelvic and femoral dynamic movements. (10.1155/2014/457573)
• [L5] Subject-specific gait combined with inverse dynamic analysis provides pre-processing parameters for FE simulation to enable more accurate biomechanical analysis of the hip joint. (10.1186/s13018-022-03094-5)
• [L5] The acetabular labrum bears a direct mechanical role during hip motion, thus resecting the hip's labrum during surgery might be detrimental for hip joint's biomechanics as it might modify strains distribution between the acetabulum and femur. (10.1007/s00167-017-4524-8)
• [L4] A normative database of hip and knee kinematics utilized by football athletes was developed. (10.1177/2325967114534591)
• [L5] Hip abductor moment arm varies substantially throughout the hip's range of motion in the coronal plane. (10.1186/1749-799x-6-6)
• [L5] The distinctive phase-dependent biomechanical response of the hip demonstrated its coordinated control strategy for balance recovery due to gait perturbations. (10.1186/s12891-023-06897-7)
• [L4] Current analysis revealed trends that degenerative hips experience more abnormal hip kinematics that leads to higher articulating surface forces and stresses within the acetabulum. (10.1016/j.arth.2019.08.057)
• [L3] Abnormal hip kinematics in women with patellofemoral pain appears to be the result of diminished hip-muscle performance as opposed to altered femoral structure. (10.1177/0363546508326711)
• [L4] A thorough appreciation of the anatomy of the abductor musculature, specific clinical signs and imaging findings will lead to an appropriate diagnosis being made and management plan instituted. (10.1007/s00167-020-06354-1)
• [L5] A six degree-of-freedom robot is appropriate to reproduce the physiological range of motion of the hip joint. (10.1186/s13018-023-03601-2)
• [L4] This study is the first to map the hip center of rotation trajectory under common movements in a large cohort, highlighting the importance of hip translation on physiologic range of motion. (10.1177/2325967124s00166)
• [L4] Additionally, patients reported significant improvement in function and pain at 1 year postoperatively, but these improvements did not correlate with improvements in hip kinematics. (10.1177/23259671251339777)
• [L3] The smartphone application is one of the practical measurements in hip rotational angles. (10.1186/s12891-021-03995-2)
• [L5] Despite simulating lower degrees of hip flexion and internal rotation, increased stress and a shift in contact location were observed in the simulated models of FAI. (10.1016/j.arthro.2017.03.018)
• [L5] The proper diagnosis and treatment of patients with concurrent hip and spine pathological processes can present a substantial challenge due to overlapping symptomatology and no consensus on which condition to address first. (10.2106/jbjs.20.01728)
• [L5] The planning of surgical procedures may be improved by the proposed classification. (10.1007/s00167-018-5318-3)
• [L4] Geometric measurements are reliably interpreted and may be useful as a further measurement of quality, while morphological features are generally poorly interpreted but improve with simpler binary classification. (10.1302/0301-620x.105b10.bjj-2023-0143.r1)
• [L1] Females had more profound symptomatology and milder morphologic abnormalities, while males had a higher activity level, larger morphologic abnormalities, more common combined-type FAI morphologies, and more extensive intra-articular disease. (10.2106/jbjs.m.01320)
• [L4] The classification developed allows for appropriate grouping and comparison of distinct CS implants. (10.1016/j.arth.2025.05.039)
• [L4] This classification system allows for the ability to evaluate differing repair patterns and their effects on postoperative clinical outcomes. (10.1177/2325967125s00101)
• [L3] The greater trochanter classification system based on the anatomy and biomechanics could distinguish various types of DDH and aid in making surgical strategies. (10.1016/j.arth.2025.08.013)
• [L4] The classification of developmental patterns illustrates the varying directional changes that can occur in lower-extremity length discrepancies and their dependence on underlying biological phenomena. (10.2106/00004623-198264050-00001)
• [L4] Several consistent anatomical levels were identified for single axial MR slice to facilitate muscle size and fatty infiltration muscle measures at the hip, providing the basis for reliable and accurate data synthesis and improvements in the validity of future between studies analyses. (10.1186/s12891-022-05439-x)
• [L3] CT was found to have higher interobserver reliability than MRI, and diagnosis should not rely exclusively on either examination or radiologic criteria. (10.1016/j.arthro.2011.10.021)
• [L3] The method was feasible with routine MRI and a short image acquisition time. (10.1177/23259671251334138)
• [L2] Type II and III sourcil types account for the majority, to which the modified approach is better. (10.1016/j.arthro.2023.11.024)
• [L5] Specifically, the variability and elongated morphology of the ME differentiated this landmark from the AT and GT, which demonstrated the most consistent morphology. (10.1016/j.asmr.2022.09.003)
• [Paper] MRI scanning is necessary to establish whether some patients have an occult fracture. (10.1016/j.injury.2007.04.023)
• [L3] The clinical relevance of this study is that capsular thickness and intra-substance changes of the anterior capsule vary which could alter capsular management strategies. (10.1007/s00167-022-07022-2)
• [L5] Based on data showing that standard MRI scans cannot replicate the appropriate level of detail for AIIS morphology classification compared to 3D CT, the author concludes that the preoperative planning CT scan should not be eliminated from the patient pathway, although future refinements in 3D MRI techniques may eventually allow them to replace low-dose 3D CT scans. (10.1016/j.arthro.2021.08.012)
• [Paper] This MRI documentation should be established as a standard examination post-reduction. (10.1007/s00402-003-0518-8)
• [L4] A precise knowledge of anatomy and clear goals in the surgical approach can minimize complications and facilitate visualization and instrumentation placement in the direct anterior approach to the hip joint. (10.1186/s12891-023-06254-8)
• [L1] The range of knee anatomy in patients scheduled for TKA is wide. (10.1016/j.arth.2017.02.028)
• [L2] On the basis of these excellent results, the authors intend to change their clinical practice to use MRI-based 3D models for future clinical practice instead of CT-based 3D models. (10.1177/0363546519869681)
• [L4] Surgical treatment limited to localized recontouring of the head-neck profile may fail to address significant components of the underlying abnormality. (10.1016/j.arth.2011.04.028)
• [Case_report] Magnetic resonance imaging is effective in localizing this type of lesion. (10.2106/00004623-198971090-00022)
• [L4] Imaging for osteonecrosis is recommended, with evidence suggesting 4- to 6-week magnetic resonance imaging and follow-up at 3 months for those with suspicious findings in the femoral head. (10.1177/03635465211036104)
• [L3] There were substantial improvements in patient-reported outcomes, showing acceptable midterm clinical healing rates and low reoperation/failure rates. (10.1016/j.arthro.2020.12.150)
• [L3] Despite improvements in clinical outcomes and bony histology, there were no difference detected in the progression of medial compartment post-traumatic gonarthrosis between groups. (10.1016/j.arthro.2017.08.096)
• [L4] Computed tomography provides a noninvasive method for studying anatomy in live subjects, allowing for the detailed mapping of position, size, and orientation of the abductor muscles of the hip. (10.2106/00004623-198769070-00010)
• [L4] Experience is currently insufficient to establish exact criteria, but the method helps confirm adequacy of coverage and guides surgical decision-making. (10.2106/00004623-198163020-00016)
• [L5] Anatomic ALL reconstruction did not reduce anterolateral rotational laxity. (10.1177/2325967116s00027)
• [L4] Pathologic changes seen on MRI were symptomatic in less than two thirds of the dancers. (10.1016/j.arthro.2012.10.012)
• [L3] However, ioMRI cannot yet replace CT scans for thorough evaluation, though it may be considered when CT is contraindicated. (10.1177/2325967125s00090)
• [L5] Most patients tend to resolve GTPS or lateral hip pain with non-surgical management in the mid-term but when everything failed, surgical options should be evaluated. (10.1007/s00167-020-06366-x)
• [L2] Operative management of fragility fractures of the pelvis should be considered for patients failing a brief period of non-operative management, however prospective randomised trials need to be performed to provide improved evidence for this intervention. (10.1186/s12891-021-04579-w)
• [L5] Biomechanical and long-term clinical studies will continue to be performed to better understand the importance of the labrum and how to restore its function. (10.1016/j.arthro.2010.12.004)
• [L3] Measurements of femoral version on CT strongly correlated with those on MRI. (10.5435/jaaos-d-25-01274)
• [L4] When nonoperative treatment fails, the PROs in these patients after operative management are comparable with those in patients with osseous cam lesions. (10.1177/03635465231206815)
• [L4] With an average follow-up time of 12 months, all clinical and functional results as well as activity and quality of life improved statistically. (10.1016/j.arthro.2013.09.021)
• [L5] Although a demanding technique with a high rate of related complications, once anatomic reconstruction of the hip is achieved, patients have a remarkably good functional capacity and implant survival during long follow-up periods. (10.1302/2058-5241.1.000026)
• [L3] Treatment strategies may need to be adjusted to preserve long-term function. (10.2106/jbjs.25.01271)
• [L5] Surgical management is indicated for progressive, painful, unilateral deformity or leg-length discrepancy, while moderate nonprogressive deformity often does not require surgery. (10.5435/00124635-199803000-00003)
• [L4] Non-operative management is associated with highly variable periods of convalescence, poor return to preinjury level of function and high risk of injury recurrence. (10.1302/2058-5241.5.200055)
• [L2] Current evidence suggests that modular BKA provides comparable functional outcome to TKA at short-term to midterm follow-up, however, with poor long-term survivorship. (10.1016/j.arth.2019.09.042)
• [L5] In non-elite patients, persistent grade 2 or 3 laxity beyond 12 weeks should prompt combined anterior cruciate ligament reconstruction with MCL repair and reconstruction. (10.1002/arj.70105)
• [L5] Further studies are required to understand if this kind of reconstruction can ameliorate proprioception as well as clinical outcome at a long-term follow-up. (10.1186/1749-799x-2-10)
• [L4] Non-operative treatments are usually ineffective, and while rotational osteotomies are effective, they are associated with significant complication rates. (10.2106/00004623-198567050-00027)
• [L1] Porous implants are effective in tackling metaphyseal bone defects showing good survivorship outcome at midterm follow-up. (10.1016/j.arth.2022.02.103)
• [L5] The study emphasizes that anatomic femoral attachment is critical to a well-functioning reconstruction and minimizes complications, while nonanatomic placement can cause significant changes in graft isometry. (10.1177/2325967115569198)
• [L5] The use of the medial portals did not cause any damage to the neurovascular structures evaluated. (10.1016/j.arthro.2013.09.004)
• [L5] Recognition of femoroacetabular impingement and early intervention before the degenerative process is advanced is likely to have a considerable impact on the natural history of the disease, delaying the onset of end-stage arthritis in young patients. (10.1016/j.arth.2007.05.039)
• [L4] The natural history is often favorable for children younger than 6 years and poor for children older than 8 to 10 years. (10.5435/jaaos-d-24-01469)
• [L3] The study aimed to determine the long-term objective and subjective outcome of untreated articular cartilage defects observed at the time of ACL reconstruction. (10.1016/j.arthro.2014.04.071)
• [L3] Specific morphological characteristics on pelvis radiographs of AVN hips were predictive for poor outcome, at a very young age. (10.1302/0301-620x.103b5.bjj-2020-1485.r1)

References

[1] Slipped Femoral Epiphysis with Severe Displacement: A Conservative Operative Treatmenmt.. The Journal of Bone and Joint Surgery. American Volume. 1957.

[2] Natural History of Structural Hip Abnormalities and the Potential for Hip Preservation. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-16-00532

[3] A South Indian cadaveric study on obturator neurovascular bundle with a special emphasis on high prevalence of ‘venous corona mortis’. Injury. 2016. DOI: 10.1016/j.injury.2016.04.032

[4] Poster 218: Localized Acetabular Bone Density Distributions Are Altered in Unilateral Femoral Acetabular Impingement. Orthopaedic Journal of Sports Medicine. 2024. DOI: 10.1177/2325967124s00187

[5] The supporting structures and layers on the medial side of the knee. The Journal of Bone & Joint Surgery. 1979. DOI: 10.2106/00004623-197961010-00011

[6] i surgical approaches to the hip joimmt amid femur have been advocated and used duritig the past cemmtury. From them we have selected a few which, be cause they respect basic fummctiommal ammatonmy, appeal to us as the muost likely to afford adequate surgical exposure amid good results.. 1963.

[7] Capsular Management During Hip Arthroscopy: From Femoroacetabular Impingement to Instability. Arthroscopy. 2011. DOI: 10.1016/j.arthro.2011.08.288

[8] Chapter 34 Anatomy and Biomechanics, Evaluation, Clinical Examination, and Imaging of the Hip. 2020.

[9] Diagnostic Imaging of Femoroacetabular Impingement. Journal of the American Academy of Orthopaedic Surgeons. 2013. DOI: 10.5435/00124635-201300001-00006

[10] Hip Vascularity: A Review of the Anatomy and Clinical Implications. Journal of the American Academy of Orthopaedic Surgeons. 2016. DOI: 10.5435/jaaos-d-15-00237

[11] Anatomical variation of the Psoas Valley: a scoping review. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-03241-1

[12] The Limping Child: Evaluation and Diagnosis. Journal of the American Academy of Orthopaedic Surgeons. 2001. DOI: 10.5435/00124635-200103000-00003

[13] Hip Disease in the Young, Active Patient: Evaluation and Nonarthroplasty Surgical Options. Journal of the American Academy of Orthopaedic Surgeons. 2008. DOI: 10.5435/00124635-200812000-00002

[14] Prevalence of Femoroacetabular Impingement Imaging Findings in Asymptomatic Volunteers: A Systematic Review. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2014.11.042

[15] Aspiration and Injection Techniques of the Lower Extremity. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-16-00762

[16] Editorial Commentary: Both Femoral Acetabular Anteversion and Retroversion May Contribute to the Effect of Femoroacetabular Impingement: What’s Your Version?. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2021.09.033

[17] Prevalence of Morphological Variations Associated With Femoroacetabular Impingement According to Age and Sex: A Study of 1878 Asymptomatic Hips in Nonprofessional Athletes. Orthopaedic Journal of Sports Medicine. 2021. DOI: 10.1177/2325967120977892

[18] Can Femoral Rotation Be Localized and Quantified Using Standard CT Measures?. Clinical Orthopaedics & Related Research. 2015. DOI: 10.1007/s11999-014-4000-4

[19] Comparison of Gap Balancing vs Measured Resection Technique in Patients Undergoing Simultaneous Bilateral Total Knee Arthroplasty: One Technique per Knee. The Journal of Arthroplasty. 2020. DOI: 10.1016/j.arth.2019.10.002

[20] Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction. Orthopaedic Journal of Sports Medicine. 2016. DOI: 10.1177/2325967116652122

[21] Femoroacetabular Impingement: Defining the Condition and its Role in the Pathophysiology of Osteoarthritis. Journal of the American Academy of Orthopaedic Surgeons. 2013. DOI: 10.5435/00124635-201300001-00004

[22] Paper #248: Does Preoperative Exercise Influence the Outcome of ACL Reconstruction?. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2013.07.252

[23] Anatomic Landmarks Utilized for Physeal‐Sparing, Anatomic Anterior Cruciate Ligament Reconstruction: An MRI‐Based Study (SS‐68). Arthroscopy. 2011. DOI: 10.1016/j.arthro.2011.03.072

[24] Proximal Femoral Osteotomies in the Adolescence: Indications and Treatment Strategies. Zeitschrift für Orthopädie und Unfallchirurgie. 2019. DOI: 10.1055/a-1023-4679

[25] Access to the Hip Joint From Standard Arthroscopic Portals: A Cadaveric Study. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2013.05.017

[26] Coronal Alignment of Fixed-Bearing Unicompartmental Knee Arthroplasty Femoral Component May Affect Long-Term Clinical Outcomes. The Journal of Arthroplasty. 2021. DOI: 10.1016/j.arth.2020.07.070

[27] Osteochondritis Dissecans Following Legg-Calve-Perthes Disease: A Report of One Case.. The Journal of Bone and Joint Surgery. American Volume. 1960.

[28] Isolated Polyethylene Insert Exchange for Flexion Instability After Primary Total Knee Arthroplasty Demonstrated Excellent Results in Properly Selected Patients. The Journal of Arthroplasty. 2020. DOI: 10.1016/j.arth.2020.01.006

[29] Anterior Intrapelvic Approach: A Comprehensive Understanding of the Anatomy. Journal of the American Academy of Orthopaedic Surgeons. 2025. DOI: 10.5435/jaaos-d-24-01050

[30] Vergleich von minimalinvasivem und transglutealem Zugang zur Implantation von Hüfttotalendoprothesen. Klinik und Ganganalyse. Zeitschrift für Orthopädie und Unfallchirurgie. 2011. DOI: 10.1055/s-0030-1250590

[31] Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip. Archives of Orthopaedic and Trauma Surgery. 2003. DOI: 10.1007/s00402-003-0554-4

[32] A Clinically Relevant Review of Hip Biomechanics. Arthroscopy. 2010. DOI: 10.1016/j.arthro.2010.01.027

[33] Influence of Hip Geometry Reconstruction on Frontal Plane Hip and Knee Joint Moments During Walking Following Primary Total Hip Replacement. The Journal of Arthroplasty. 2019. DOI: 10.1016/j.arth.2019.07.027

[34] Is there a need of custom-made prostheses for total hip arthroplasty? Gait analysis, clinical and radiographic analysis of customized femoral components. Archives of Orthopaedic and Trauma Surgery. 2008. DOI: 10.1007/s00402-008-0717-4

[35] A biomechanical analysis of the soft tissue and osseous constraints of the hip joint. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-2255-4

[36] The Demographics of High-level and Recreational Athletes With Intra-articular Hip Injury. Orthopaedic Journal of Sports Medicine. 2013. DOI: 10.1177/2325967113s00059

[37] Pre-operative templating in THA. Part I: a classification of architectural hip deformities. Archives of Orthopaedic and Trauma Surgery. 2019. DOI: 10.1007/s00402-019-03298-1

[38] Kinematic Analysis of Healthy Hips during Weight-Bearing Activities by 3D-to-2D Model-to-Image Registration Technique. BioMed Research International. 2014. DOI: 10.1155/2014/457573

[39] Changes in hip joint contact stress during a gait cycle based on the individualized modeling method of “gait-musculoskeletal system-finite element”. Journal of Orthopaedic Surgery and Research. 2022. DOI: 10.1186/s13018-022-03094-5

[40] Mechanical strains passing through the acetabular labrum modify its shape during hip motion: an anatomical study. Knee Surgery, Sports Traumatology, Arthroscopy. 2017. DOI: 10.1007/s00167-017-4524-8

[41] Position-Specific Hip and Knee Kinematics in NCAA Football Athletes. Orthopaedic Journal of Sports Medicine. 2014. DOI: 10.1177/2325967114534591

[42] Hip abductor moment arm - a mathematical analysis for proximal femoral replacement. Journal of Orthopaedic Surgery and Research. 2011. DOI: 10.1186/1749-799x-6-6

[43] A neuromusculoskeletal modelling approach to bilateral hip mechanics due to unexpected lateral perturbations during overground walking. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06897-7

[44] In Vivo Determination and Comparison of Total Hip Arthroplasty Kinematics for Normal, Preoperative Degenerative, and Postoperative Implanted Hips. The Journal of Arthroplasty. 2020. DOI: 10.1016/j.arth.2019.08.057

[45] Predictors of Hip Internal Rotation during Running. The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546508326711

[46] Pathogenesis and contemporary diagnoses for lateral hip pain: a scoping review. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06354-1

[47] Calibration procedure and biomechanical validation of an universal six degree-of-freedom robotic system for hip joint testing. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-03601-2

[48] Poster 197: A 3D Analysis of Hip Center of Rotation Trajectory and its Effects on Impingement-Free Range of Motion: A Dynamic Analysis of 1222 Hips. Orthopaedic Journal of Sports Medicine. 2024. DOI: 10.1177/2325967124s00166

[49] Restoration of Hip Kinematics After Arthroscopy for Femoroacetabular Impingement Syndrome: A 1-Year Evaluation of Gait and Stair Performance. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/23259671251339777

[50] Validity and reliability of smartphone applications for measurement of hip rotation, compared with three‐dimensional motion analysis. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-03995-2

[51] The Influence of Squat Kinematics and Cam Morphology on Acetabular Stress. Arthroscopy. 2017. DOI: 10.1016/j.arthro.2017.03.018

[52] The Hip-Spine Challenge. Journal of Bone and Joint Surgery. 2021. DOI: 10.2106/jbjs.20.01728

[53] A proposal for a new classification of pes anserinus morphology. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5318-3

[54] Chapter 13 Extra-articular Hip Disorders. 2019.

[55] Paediatric hip ultrasound. The Bone & Joint Journal. 2023. DOI: 10.1302/0301-620x.105b10.bjj-2023-0143.r1

[56] Clinical Presentation and Disease Characteristics of Femoroacetabular Impingement Are Sex-Dependent. Journal of Bone and Joint Surgery. 2014. DOI: 10.2106/jbjs.m.01320

[57] Condylar-Stabilized Designs in Total Knee Arthroplasty: A Classification System and Review of Outcomes. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2025.05.039

[58] Paper 44: Medial Meniscus Ramp Tears: An Internationally Developed Surgically Relevant Classification System Based on Tear Morphology. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/2325967125s00101

[59] A Novel Classification Method for Developmental Dysplasia of the Hip Based on the Greater Trochanter of the Femur. The Journal of Arthroplasty. 2025. DOI: 10.1016/j.arth.2025.08.013

[60] Developmental patterns in lower-extremity length discrepancies.. The Journal of Bone & Joint Surgery. 1982. DOI: 10.2106/00004623-198264050-00001

[61] Towards defining muscular regions of interest from axial magnetic resonance imaging with anatomical cross-reference: a scoping review of lateral hip musculature. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05439-x

[62] Femoral Anteversion in the Hip: Comparison of Measurement by Computed Tomography, Magnetic Resonance Imaging, and Physical Examination. Arthroscopy. 2012. DOI: 10.1016/j.arthro.2011.10.021

[63] Magnetic Resonance Imaging–Based 3-Dimensional Models of the Pelvis and Hip Using Machine Learning for Automatic Bone Segmentation in a Dynamic Hip Impingement Simulation. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/23259671251334138

[64] A Modified Approach to Measuring Femoro‐Epiphyseal Acetabular Roof Index Has Better Intraobserver and Interobserver Reliability Compared With the Original Femoro‐Epiphyseal Acetabular Roof Index. Arthroscopy. 2023. DOI: 10.1016/j.arthro.2023.11.024

[65] Landmarks Used in Medial Patellofemoral Ligament Reconstruction Have Variable Topography. Arthroscopy, Sports Medicine, and Rehabilitation. 2022. DOI: 10.1016/j.asmr.2022.09.003

[66] Is magnetic resonance imaging (MRI) necessary to exclude occult hip fracture?. Injury. 2007. DOI: 10.1016/j.injury.2007.04.023

[67] The anterior hip capsule is thinner in dysplastic hips: a study comparing different young adult hip patients. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07022-2

[68] Editorial Commentary: Low–Radiation Dose 3‐Dimensional Computed Tomography Scan Reconstruction Is the Best Way to Visualize the Anterior Inferior Iliac Spine—For Now. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2021.08.012

[69] Magnetic resonance imaging after reduction for congenital dislocation of the hip. Archives of Orthopaedic and Trauma Surgery. 2003. DOI: 10.1007/s00402-003-0518-8

[70] Hybrid of Smith-Peterson and Watson-Jones minimally invasive direct anterior approach to the hip joint. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06254-8

[71] The Impact of Mechanical and Restricted Kinematic Alignment on Knee Anatomy in Total Knee Arthroplasty. The Journal of Arthroplasty. 2017. DOI: 10.1016/j.arth.2017.02.028

[72] Patient-Specific 3-D Magnetic Resonance Imaging–Based Dynamic Simulation of Hip Impingement and Range of Motion Can Replace 3-D Computed Tomography–Based Simulation for Patients With Femoroacetabular Impingement: Implications for Planning Open Hip Preservation Surgery and Hip Arthroscopy. The American Journal of Sports Medicine. 2019. DOI: 10.1177/0363546519869681

[73] The Cam Impinging Femur Has Multiple Morphologic Abnormalities. The Journal of Arthroplasty. 2011. DOI: 10.1016/j.arth.2011.04.028

[74] Neurilemoma of the saphenous nerve presenting as pain in the knee. A case report.. The Journal of Bone & Joint Surgery. 1989. DOI: 10.2106/00004623-198971090-00022

[75] Hip Dislocation and Subluxation in Athletes: A Systematic Review. The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211036104

[76] Repair of Horizontal Cleavage Meniscus Tears. Results from a Prospective Multi-Center STITCH Trial. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2021. DOI: 10.1016/j.arthro.2020.12.150

[77] Paper #121: Subchondroplasty for the Treatment of Post‐Traumatic Bone Marrow Lesions of the Medial Femoral Condyle in a Pre‐Clinical Canine Model. Arthroscopy. 2017. DOI: 10.1016/j.arthro.2017.08.096

[78] Polyethylene Wear After Total Hip Arthroplasty: The Effect of a Modular Femoral Head with an Extended Flange-Reinforced Neck.. The Journal of Bone and Joint Surgery. American Volume*. 1998.

[79] Anatomy of the abductor muscles of the hip as studied by computed tomography.. The Journal of Bone & Joint Surgery. 1987. DOI: 10.2106/00004623-198769070-00010

[80] Preoperative roentgenographic evaluation for osteotomies about the hip in children.. The Journal of Bone & Joint Surgery. 1981. DOI: 10.2106/00004623-198163020-00016

[81] Biomechanical Analysis of Simulated Clinical Testing and Reconstruction of the Anterolateral Ligament of the Knee. Orthopaedic Journal of Sports Medicine. 2016. DOI: 10.1177/2325967116s00027

[82] Correlation of Clinical and Magnetic Resonance Imaging Findings in Hips of Elite Female Ballet Dancers. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2012.10.012

[83] Paper 33: Novel Hip MRI Sequence Provides Consistent Osseous Morphology Dimensions for FAI Evaluation as CT Imaging. Orthopaedic Journal of Sports Medicine. 2025. DOI: 10.1177/2325967125s00090

[84] Non‐surgical treatment as the first step to manage peritrochanteric space disorders. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06366-x

[85] Operative management of fragility fractures of the pelvis – a systematic review. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04579-w

[86] Comments on “Labral Base Refixation in the Hip: Rationale and Technique for an Anatomic Approach to Labral Repair”. Arthroscopy. 2011. DOI: 10.1016/j.arthro.2010.12.004

[87] The Relationship Between Prone Range of Motion and Measured Femoral Version on Advanced Imaging in Adolescent Patients. Journal of the American Academy of Orthopaedic Surgeons. 2026. DOI: 10.5435/jaaos-d-25-01274

[88] Soft Tissue Cam Impingement in Adolescents: MRI Reveals Impingement Lesions Underappreciated on Radiographs. The American Journal of Sports Medicine. 2023. DOI: 10.1177/03635465231206815

[89] Proximal Alpha Angle Persists Abnormal in Patients with a Residual Bony Prominence after Surgery for Femoroacetabular Impingement. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2013.09.021

[90] Reconstruction of neglected developmental dysplasia by total hip arthroplasty with subtrochanteric shortening osteotomy. EFORT Open Reviews. 2016. DOI: 10.1302/2058-5241.1.000026

[91] Thigh Muscle Changes at Long-Term Evaluation Following ACL Injury Differ from Early Changes Associated with ACL Injury and Reconstruction. Journal of Bone and Joint Surgery. 2026. DOI: 10.2106/jbjs.25.01271

[92] Coxa Vara in Childhood: Evaluation and Management. Journal of the American Academy of Orthopaedic Surgeons. 1998. DOI: 10.5435/00124635-199803000-00003

[93] The management of proximal rectus femoris avulsion injuries. EFORT Open Reviews. 2020. DOI: 10.1302/2058-5241.5.200055

[94] Systematic Review of Modular Bicompartmental Knee Arthroplasty for Medio-Patellofemoral Osteoarthritis. The Journal of Arthroplasty. 2020. DOI: 10.1016/j.arth.2019.09.042

[95] Treatment of Medial Collateral Ligament Injuries in the Setting of Anterior Cruciate Ligament Rupture. Arthroscopy. 2026. DOI: 10.1002/arj.70105

[96] Femoral tunnel placement in anterior cruciate ligament reconstruction: rationale of the two incision technique. Journal of Orthopaedic Surgery and Research. 2007. DOI: 10.1186/1749-799x-2-10

[97] Lower-extremity rotational problems in children. Normal values to guide management.. The Journal of Bone & Joint Surgery. 1985. DOI: 10.2106/00004623-198567050-00027

[98] Comparison of Different Strategies in Revision Arthroplasty of the Knee with Severe Bone Loss: A Systematic Review and Meta-Analysis of Clinical Outcomes. The Journal of Arthroplasty. 2022. DOI: 10.1016/j.arth.2022.02.103

[99] Troubleshooting the Femoral Attachment During Medial Patellofemoral Ligament Reconstruction. Orthopaedic Journal of Sports Medicine. 2015. DOI: 10.1177/2325967115569198

[100] Medial Hip Arthroscopy Portals: An Anatomic Study. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2013.09.004

[101] Hip Pain in Young Adults. The Journal of Arthroplasty. 2007. DOI: 10.1016/j.arth.2007.05.039

[102] Legg-Calvé-Perthes Disease. Journal of the American Academy of Orthopaedic Surgeons. 2025. DOI: 10.5435/jaaos-d-24-01469

[103] Distal Femoral Condyle Osteochondral Allograft Topography: Medial Versus Lateral Condyle. Arthroscopy. 2014. DOI: 10.1016/j.arthro.2014.04.071

[105] Morphological variants to predict outcome of avascular necrosis in developmental dysplasia of the hip. The Bone & Joint Journal. 2021. DOI: 10.1302/0301-620x.103b5.bjj-2020-1485.r1