Why this operation has been suggested¶
The operation means cutting and reshaping the main bone of the lower leg, the tibia, so your weight shifts away from the worn part of the knee. We usually suggest it for people who are younger and active, often under 60, with arthritis in one part of the knee rather than the whole joint. It suits people with physical jobs or those who want to keep playing sport.
The aim is to relieve pain and let you stay active while keeping your own knee. The operation has a survival rate of over 96% at 5 years. We will talk through whether it suits you and decide together.
Before the operation¶
Once surgery is decided, we plan it carefully. You will need X-rays taken while you are standing, and sometimes an MRI scan, which uses magnets to show the soft parts of the knee. These pictures show where the worn cartilage is and help us work out exactly how much to reshape the bone. Most people need nothing more. If you have other medical conditions, you may need blood tests or a review with the anaesthetist, the doctor who puts you to sleep. In the days before surgery, we will tell you which medicines to stop and when. Do not eat or drink for seven hours before your operation; we ask for a little longer than usual so your time can be brought forward if the theatre list runs early. Arrange for someone to drive you home, and wear loose, comfortable clothing.
On the day¶
You arrive at the hospital's surgical admissions unit, where you are checked in and prepared for theatre. You meet the anaesthetist, the doctor who puts you to sleep. This operation is done under general anaesthetic. A regional nerve block is sometimes added for post-operative pain relief; the anaesthetist will discuss this with you on the day. You are then taken into the operating theatre, where the operation is performed.
You wake up in the recovery area, where nurses watch over you while the anaesthetic wears off. Once you are stable, you either go to the ward or go home, depending on the procedure and your recovery.
What the operation involves¶
The operation is done through a cut on the inner side of your knee, over the upper part of the tibia, the main bone of your lower leg. Your surgeon cuts most of the way through this bone and then gently opens the gap, which changes the angle of the bone below your knee. This shifts your body weight onto the healthier, less worn side of the joint.
Once the bone is in the planned position, a metal plate with screws holds it in place while it heals. The plate stays inside your knee. In some cases it is removed later through the same area, which can ease symptoms for some people. The cut is then closed and covered with a dressing.
The aim of all this is to unload the worn part of your knee, which is what eases the pain. Your surgeon plans the correction carefully before the operation using your standing X-rays, so the bone is opened by exactly the amount worked out for your leg.
After the operation¶
You wake up in the recovery ward, where nurses watch over you while the anaesthetic wears off. Your knee will be covered with a dressing, and you may feel some pain as the numbness fades. The nurses will give you medicine to keep you comfortable. A physiotherapist may help you stand and take a few steps, with crutches, on the day of surgery or the next morning. Someone should stay with you for the first 24 hours after you get home. Your team will tell you whether you go home the same day or stay one night in hospital. We leave the dressing on for about 10 days; please do not take it off before then unless we tell you to. We change or remove it when we see you.
Recovery¶
The first days are about comfort. Your knee will be sore and swollen, and the skin near the cut may feel tight. Pain medicine keeps this manageable, and resting with your leg raised helps the swelling settle. Some people notice the swelling is worse in the evenings at first. Ice packs, used in a towel, can ease this.
You will walk with crutches at first, putting only part of your weight through the leg while the bone heals. A physiotherapist will guide your exercises. These start gently, moving the knee and keeping the thigh muscles working, then build up as the bone knits. The dressing stays on for about 10 days; we change or remove it when we see you.
Day to day, you will need help with stairs and shopping for a while. You can move around the house, rest with your leg up, and do your exercises several times a day. Sleeping on your back with the leg supported is usually easiest. You can shower once we say the dressing can come off.
The milestones are about events, not dates. Once the bone has healed enough to take full weight, walking gets steadier and crutches are gradually left behind. As strength returns, you can start longer walks, then return to work and sport as your knee allows. Most people get back to sport at a level similar to or better than before the operation.
Recovery varies from person to person. Your surgeon and physiotherapist will guide your timeline.
What can go wrong¶
Most patients do well, but problems can occasionally happen. Your surgeon and the team monitor you closely to spot any issue early.
The bone may be slow to knit, or in rare cases may not join at all. You might notice pain at the cut site that does not settle, or a feeling that the knee is giving way. If this happens, bring it up at your next review.
The metal plate can sometimes irritate you. This often feels like aching or tenderness over the plate, especially in cold weather or after activity. If it bothers you, the plate can be removed later through a small cut in the same area. Mention it at your review.
Infection is uncommon but can happen. Watch for redness spreading out from the wound, warmth, swelling that gets worse rather than better, or fluid leaking from the cut. You may feel feverish. If you notice any of these, call the clinic straight away.
A blood clot can form in the deep veins of the leg. This feels like sudden swelling and tenderness in the calf, sometimes with the skin feeling hot. If you notice this, contact the clinic the same day. If you become short of breath or have chest pain, go to the emergency department.
Nerves near the knee can be bruised during surgery. This may feel like numbness, tingling or weakness in the foot or toes, or difficulty lifting the foot. Many of these settle on their own. Tell your surgeon at the next review if you notice it.
The corrected bone can rarely slip back toward its old position. You might notice the knee gradually feeling out of line again, or pain returning on the worn side. Bring this up at your review.
Other problems can include a fracture during the operation, stiffness in the knee, or a rare pain condition that causes burning, sensitivity and swelling well beyond the normal healing period. Your team will pick these up and manage them with you.
The complications table on this page lists typical rates if you want the specifics.
When to call us¶
Most problems show up early, and we would rather hear about them sooner than later. Call us if you have a fever, if the redness around the wound is spreading, or if fluid is leaking from the cut. Call us the same day if your calf becomes suddenly swollen and tender. Go to emergency if you become short of breath or have chest pain. Go to emergency if you lose feeling in your leg or foot, or you cannot move it. Call us if pain suddenly gets much worse, or the swelling keeps growing after the first few days.
Evidence & references
This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.
Anatomy & Pathophysiology¶
Complications and Pathology¶
- Recurrence of varus deformity is reported to occur in 5% to 30% of patients with proximal tibial osteotomy [1].
- Recurrence of varus deformity was the most common complication in Coventry's report of 213 proximal tibial osteotomies [1].
- Coventry attributed the recurrence of varus deformity to inadequate correction at the time of surgery [1].
- Overcorrection beyond the normal 5 degrees of anatomic valgus decreased the frequency of recurrent varus deformity [1].
- Peroneal nerve injury is most often related to fibular osteotomy performed in conjunction with proximal tibial osteotomy [1].
- The peroneal nerve is most at risk during osteotomy of the proximal fibula, where the nerve wraps around the neck of the fibula before dividing into deep and superficial branches [1].
- Popliteal artery injury is rare but devastating [1].
- At 90 degrees of flexion, the distance between the osteotomy blade and the popliteal artery averaged 10.6 mm in a cadaver study [1].
- Most patients develop significant patella baja after proximal tibial osteotomy [1].
- Shortening of the patellar tendon after prolonged immobilization is a factor that may cause patella baja [1].
- New bone formation at the site of the osteotomy in the area of the insertion of the patellar tendon is a factor that may cause patella baja [1].
- Fibrosis of the patellar tendon is a factor that may cause patella baja [1].
- The decrease in the height of the patella has no appreciable effect on the success or failure of the osteotomy or the need for subsequent total joint replacement [1].
- Patella baja is likely to make a subsequent total knee arthroplasty more technically demanding [1].
Comparative Outcomes¶
- A meta-analysis by Fu et al. showed better knee function in the arthroplasty group compared to high tibial osteotomy [1].
- A meta-analysis by Fu et al. showed no difference in knee score between the arthroplasty group and high tibial osteotomy [1].
- The 10-year survival rate for medial compartment arthroplasty reported by Pandit et al. was 91% [1].
- The 10-year survival rate for high tibial osteotomy was 60% [1].
- Unicompartamental arthroplasty is less stressful for the patient than total knee arthroplasty [1].
- Unicompartamental arthroplasty is more likely to be “forgotten” by the patient according to Zuiderbaan et al. [1].
- Patients with the varus morphotype may be better served with an osteotomy to unload the already overloaded medial compartment according to Becker and Hirschmann [1].
- Osteotomy may be preferred if the underlying cause is significant malalignment [1].
- Unicompartamental arthroplasty may be best suited for true medial compartment arthritis [1].
- Total knee arthroplasty may be the best choice if the problem is an undiagnosed early inflammatory arthritis [1].
Investigations¶
Radiographic Evaluation¶
- Plain radiographs are appropriate initial imaging studies for most knee conditions because they allow the assessment of traumatic injury, arthritis, patellofemoral alignment, osteochondral injury, bone neoplasm, and surgical implants [7].
- Orthogonal views for knee imaging should include at least two perpendicular views: AP and lateral [7].
- Weight-bearing AP (extension) views are used to assess cartilage loss from the distal femur and tibial plateau [7].
- Weight-bearing PA (Rosenberg; flexion) views are used to assess cartilage loss from the posterior femur and tibial plateau [7].
- Patellofemoral views are used to assess patellofemoral alignment (tilt/subluxation), patellar and trochlear morphology, osteochondral injury, and patellofemoral arthritis [7].
- A notch view is used to assess posterior femoral cartilage, notch width, and osteophytes [7].
- Radiographs may identify subchondral sclerosis, joint space narrowing, subchondral cysts (variable), osteophytes (variable), and joint subluxation in osteoarthritis [7].
- Radiographs may identify joint space loss and peripheral bone erosion in inflammatory arthropathy [7].
- Radiographs may identify subchondral radiolucency, most common in the medial femoral condyle, in osteochondral defects [7].
- Radiographs may identify linear radiolucency or radiodensity, most common in the proximal medial tibia, in stress fractures [7].
- Radiographs may identify a mixed sclerotic pattern with a subchondral, epiphyseal, or metaphyseal location in osteonecrosis [7].
- Radiographs may identify malalignment, osteophytes, cysts, and joint space loss in patellofemoral disease [7].
- Radiographs can underestimate isolated chondral lesions but may demonstrate joint space narrowing, osteophytes, sclerosis, and cysts [9].
- Weight-bearing AP and lateral views and an axial view of the patellofemoral joint should be reviewed for articular cartilage evaluation [9].
- The ability to detect subtle narrowing or an isolated chondral defect on the flexion surface may be improved with a semiflexed PA view [9].
- Long leg alignment views are used to determine the mechanical axis [9].
- If the mechanical axis traverses the involved compartment (varus knees with medial compartment lesions or valgus knees with lateral compartment lesions), realignment may need to be considered as an initial procedure or as an adjunct to a cartilage restorative procedure [9].
- Radiographs are still the standard for initial evaluation of knee arthritis [13].
- Images for knee arthritis evaluation should include weight-bearing AP and lateral views [13].
- Images for knee arthritis evaluation should include a view of the weight-bearing knee flexed at 45-degree angle, imaged posterior to anterior [13].
- Images for knee arthritis evaluation should include a sunrise view (i.e., Merchant view) [13].
- Images for knee arthritis evaluation should include extension and flexion lateral views [13].
- A standing full-length AP radiograph from hip joint to ankle joint is used to evaluate limb alignment and knee deformity [13].
- A standing full-length AP radiograph is used to identify femoral and/or tibial bone deformity (developmental or traumatic) [13].
- The KL rating grades extent of OA based on review of AP knee radiograph [13].
- Primary features used for KL rating include osteophytes (periarticular and tibial spine) and joint space narrowing [13].
- KL Grade 0 indicates normal knee features with no OA [13].
- KL Grade 1 indicates OA possibly present [13].
- KL Grade 2 indicates OA present with minimal severity [13].
- KL Grade 3 indicates OA present with moderate severity [13].
- KL Grade 4 indicates OA present with severe severity [13].
- Knee arthroplasty is recommended when Grade 4 findings are present [13].
Computed Tomography¶
- Three-dimensional CT study provides enhanced bone detail [7].
- Imaging in the axial, sagittal, and coronal planes may help visualize fracture lines and displacement, osteolytic lesions around joint arthroplasty, and cortical disruption in cases of infection or neoplasia [7].
- Three-dimensional reconstructions may help with preoperative planning for complex intra-articular fractures, multiplanar osteotomy for limb malalignment, and reconstitution of bone loss in joint arthroplasty [7].
- Axial plane imaging of the hip and knee can help assess the rotational alignment of components of a total knee arthroplasty in cases of patellar maltracking [7].
- Three-dimensional CT with remodeling is used for preoperative planning for reconstruction associated with dysplasia, post-trauma planning, and complex total knee arthroplasty (TKA) planning [13].
Magnetic Resonance Imaging¶
- Increasing strength of the magnetic field (measured in Tesla units) increases the resolution of images [7].
- An injected contrast agent (intravenous or intra-articular) may help delineate specific tissues of interest in MRI [7].
- MRI may identify the presence of edema, intra-articular fluid, disruption of ligament fibers, and an atypical ligament contour to suggest cruciate ligament injury [7].
- MRI can identify patterns of meniscal injury by location (anterior, midbody, posterior, peripheral, articular), pattern (horizontal, longitudinal, radial, complex), and displacement [7].
- MRI may identify the degree of articular cartilage injury (chondrosis, full-thickness cartilage loss), the presence of associated bone marrow edema, and the location (medial condyle, lateral condyle, trochlea, patella; anterior, posterior) [7].
- MRI may identify edema, avulsion, or discontinuity for the MCL/lateral collateral ligament (LCL) or associated posteromedial and posterolateral ligamentous complexes [7].
- MRI may be used to assess the continuity of the quadriceps or patellar tendon [7].
- MRI may be used to assess the margin of resection for a neoplasm, identify vascular malformation, or define the location of nerves or vessels relative to popliteal cysts [7].
- MRI can be used to evaluate articular cartilage morphology [9].
- MRI is grossly overused in the arthritic patient population [13].
- If the joint space is significantly narrowed on radiograph, then MRI is not indicated [13].
- MRI is used when osteonecrosis is suspected [13].
- MRI can be helpful in confirming MCL diagnosis and helping to rule out concomitant meniscal injury [3].
- MRI is useful for confirming MCL injury and identifying the site of injury [3].
- MRI is useful to detect the presence of meniscal and other injuries to the knee [3].
- Relative indications for an MRI include an uncertain ACL status despite multiple examinations, evaluation of a suspected meniscal tear, or preoperative evaluation for a planned MCL reconstruction or repair [3].
- MRI should be obtained as a useful adjunct to help diagnose posterolateral corner injuries in LCL injuries [14].
- MRI is often a useful adjunct for diagnosing posterolateral corner and LCL injuries in the severely injured knee [14].
- MRI findings can refocus the examination to the posterolateral structures when posterolateral injury can often go unnoticed during an initial evaluation [14].
- MRI can prove to be an extremely valuable adjunct in diagnosis when pain and guarding at the time of injury can often obscure posterolateral injury [14].
Nuclear Medicine¶
- Nuclear medicine involves labeled radionuclide injection followed by delayed imaging of gamma radiation [7].
- Areas of increased radionuclide concentration appear bright or “hot” in nuclear medicine imaging [7].
- Nuclear medicine provides a nonspecific study that does not define the etiology of an abnormality but rather the presence of an abnormality that may correlate with a clinical concern [7].
- Increased radionuclide activity in bone may be a normal postoperative finding for up to 6 to 12 months after a fracture repair or arthroplasty [7].
- Technetium-99 (Tc-99) is a radionuclide that may help identify infection, neoplasia, occult fracture, bone healing, active phases of heterotopic ossification, implant loosening, or failure of osseointegration [7].
- Gallium-67 (Ga-67) is a radionuclide that may help differentiate between aseptic and septic prosthetic loosening [7].
- 24 to 72 hours are needed for a complete Gallium-67 (Ga-67) study [7].
Physical Examination¶
- Physical examination along with radiographic or advanced imaging findings must be used concomitantly to determine the source of each patient’s symptoms and to determine appropriate surgical intervention when nonsurgical measures have failed [2].
- The physical examination for knee injury begins with observation of the patient’s gait [5].
- The uninjured knee is examined as a basis of comparison with the injured knee [5].
- Any swelling or effusion should be noted during physical examination [5].
- A small effusion will cause obliteration of the recesses on the medial and lateral aspects of the patellar tendon [5].
- With a larger effusion, diffuse swelling is present in the region of the suprapatellar pouch [5].
- A fluid wave can be palpated on the sides of the patella with a larger effusion [5].
- Active and then passive range of motion is tested carefully during physical examination [5].
- The knee is palpated to define areas of localized tenderness [5].
- The joint lines are located at the level of the inferior pole of the patella when the knee is flexed to 90 degrees [5].
- To determine varus and valgus stability, the patient’s foot is held between the examiner’s elbow and hip [5].
- Medial knee pain and instability at 30 degrees of flexion is diagnostic for MCL injury [3].
- Laxity to valgus stresses is assessed by the amount of medial joint space opening that occurs at 30 degrees of flexion [3].
- It is important to stress the knee at 30 degrees of flexion because with the knee in full extension the posterior capsule and PCL will stabilize the knee to valgus stress [3].
- Zero opening is considered normal for MCL injury grading [3].
- 1–4 mm of medial joint space opening indicates a grade I MCL injury [3].
- 5–9 mm of medial joint space opening indicates a grade II MCL injury [3].
- 10–15 mm of medial joint space opening indicates a complete or grade III MCL injury [3].
- Grade I and II MCL injuries typically have a firm end point to valgus stress [3].
- A grade III MCL injury tends to have a soft end point to valgus stress [3].
- Varus stress to the knee with opening at 30 degrees of flexion is diagnostic for an isolated LCL injury [14].
- The integrity of the LCL is assessed by placing a varus stress, with the knee in full extension and 30 degrees of flexion [14].
- Baseline varus opening is widely variable and should be compared to the contralateral leg [14].
- The average baseline for varus opening is 7 degrees [14].
- Exam findings with an isolated LCL injury should include varus laxity at 30 degrees of flexion and no instability in full extension [14].
- The dial test is the most useful test to evaluate for posterolateral instability [14].
- The dial test is performed at 30 and 90 degrees of flexion with a significant difference being an angle 5 degrees or greater than the contralateral leg [14].
- Injury to the posterolateral capsule alone is confirmed with greater external rotation at 30 degrees [14].
- An isolated PCL injury is confirmed with greater external rotation at 90 degrees [14].
- Injury to both posterolateral capsule and PCL is confirmed when there is greater rotation at 30 and 90 degrees compared to the uninjured leg [14].
- Patients commonly present with a history of a precipitating traumatic event or previous surgery for articular cartilage defects [9].
- An effusion, motion deficits, or limb malalignment may be observed in patients with articular cartilage defects [9].
- Knee stability should be compared with the normal side in patients with articular cartilage defects [9].
- Pain with weight bearing is a clinical presentation of knee arthritis [13].
- Pain with weight bearing is aggravated by stairs, inclines, and transition from sit to stand [13].
- Bowing deformity and instability are seen later in the clinical presentation of knee arthritis [13].
- Knee thrust is seen later in the clinical presentation of knee arthritis [13].
- A varus thrust indicates ligament stretch-out on the convex side of the thrust [13].
- A varus thrust overloads the medial compartment [13].
- A varus thrust accelerates cartilage degeneration in the medial compartment [13].
- A valgus thrust overloads the lateral compartment [13].
- A valgus thrust accelerates cartilage degeneration in the lateral compartment [13].
Complications¶
General Complications¶
- Reported complications of proximal tibial osteotomy include recurrence of deformity, peroneal nerve palsy, nonunion, infection, knee stiffness or instability, intraarticular fracture, deep vein thrombosis, compartment syndrome, patella infra, and osteonecrosis of the proximal fragment [1].
- Inadequate correction and recurrent varus deformity have been reported to occur in 5% to 30% of patients with proximal tibial osteotomy [1].
- Recurrence of a varus deformity was the most common complication in Coventry's report of 213 proximal tibial osteotomies [1].
- Coventry suggested that overcorrection beyond the normal 5 degrees of anatomic valgus decreased the frequency of recurrent varus deformity [1].
Neurovascular Injury¶
- The peroneal nerve is most at risk with osteotomy of the proximal fibula, where the nerve wraps around the neck of the fibula before dividing into deep and superficial branches [1].
- A cadaver study demonstrated that at 90 degrees of flexion, the distance between the osteotomy blade and the popliteal artery averaged only 10.6 mm [1].
- Authors of a cadaver study recommended keeping something substantial between the proximal tibia and the popliteal artery, especially when using an oscillating power saw [1].
Patellar Position¶
- Factors that may cause patella baja include shortening of the patellar tendon after prolonged immobilization, new bone formation at the site of the osteotomy in the area of the insertion of the patellar tendon, and fibrosis of the patellar tendon [1].
References¶
[1] Campbell S Operative Orthopaedics 4 Volume Set. SOFT-TISSUE PROCEDURES AND OSTEOTOMIES ABOUT THE KNEE > GENERAL COMPLICATIONS OF HIGH TIBIAL OSTEOTOMY.
[2] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Knee Arthroscopy and Preservation, Knee Reconstruction > Introduction.
[3] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 3Sports Medicine > 1. Medial Collateral Ligament Injuries.
[5] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 3Sports Medicine > Image KNEE INJURIES.
[7] Aaos Comprehensive Orthopaedic Review 3. Radiographic Evaluation and Surgical Anatomy of the Knee > I. Radiographic Evaluation.
[9] Aaos Comprehensive Orthopaedic Review 3. Articular Cartilage Injury and Treatment > IV. Full-Thickness Outerbridge Grade IV Defects.
[13] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > SECTION 11 KNEE ARTHRITIS ASSESSMENT.
[14] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 3Sports Medicine > 2. Lateral Collateral Ligament Injuries.