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Pronator and AIN Release

40 citationsUpdated Aug 2026

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Overview

Pronator syndrome and anterior interosseous nerve (AIN) syndrome are managed initially with conservative measures, including activity modification, rest, and anti-inflammatory medication [5]. Surgical decompression is reserved for cases where symptoms persist despite these nonoperative interventions [5]. The timing for operative intervention differs by diagnosis: pronator syndrome warrants surgery after persistent symptoms for more than 6 months [1], whereas AIN syndrome requires a minimum of 12 months with no signs of motor improvement [1]. In most cases, surgical decompression of the median or anterior interosseous nerve in the forearm is rarely indicated, and a prolonged nonsurgical approach is warranted [8].

Diagnostic clarity remains a challenge, as the diagnosis of pronator syndrome lacks objective pathophysiology and is supported only by subjective operative findings and relief after surgery [4]. There is a paucity of controlled trials demonstrating that operative treatment for pronator syndrome is more effective than other treatments or sham surgery [4]. Terminology is evolving; the term pronator syndrome should be replaced with superficialis-pronator syndrome, and lacertus syndrome and superficialis-pronator syndrome should be clearly presented as distinct targets for surgical release [11].

Minimally invasive techniques offer favorable outcomes with reduced morbidity. Pronator teres symptoms disappeared in 93% of cases following a mini-invasive decompression technique [2]. An endoscopically assisted approach adequately and safely decompressed all anatomical points of compression and improved DASH scores [6]. This endoscopic technique is associated with minimal damage and is foreseen to have wide indication in the future for pronator syndrome [3]. In contrast, the pronator teres release is more invasive, requiring more complicated surgical skills, deeper dissection, and more invasive anesthetic preparation compared to other techniques [9]. Specific anatomical anomalies also dictate surgical strategy; resection of a segment of the persistent median artery is the recommended treatment for pronator syndrome associated with this anomaly [7]. Additionally, surgical release of lacertus fibrosis can effectively relieve pressure over the pronator and allow the patient to resume previous activities [14].

Anatomy & Pathophysiology

Pronator syndrome and anterior interosseous nerve syndrome involve compression of the median nerve and its branches [1]. Pronator syndrome is characterized by proximal median nerve compression [10], whereas anterior interosseous nerve syndrome is typified by hourglass-like fascicular constrictions [24]. These fascicular constrictions are predominantly located in the posterior or posteromedial region proximal to the elbow joint line [24]. Clinically, the hand in anterior interosseous nerve syndrome exhibits a typical appearance with a characteristic disturbance of pinch [26].

Six potentially compressive structures neighboring or crossing the median nerve have been inventoried and mapped at the elbow and proximal forearm [36]. These compressive structures are located at precise proximal-to-distal locations with variations of 0.5 to 1.5 cm [36]. The ulnar head of the pronator teres muscle is fibrotic or fibromuscular in 71.5% of cases [38]. The morphology and location of the ulnar head of the pronator teres relative to the median nerve are important for surgical treatment of pronator syndrome [38]. Dissection along the ulnar side of the median nerve can possibly decrease the chance of injury to the anterior interosseous nerve during decompression [12].

Ligamentous and Fibrous Structures: Struthers ligament is a non-osseous fibrous ligament that can cause median nerve entrapment at the elbow [40]. A palmaris longus variant with a central muscle belly and both distal and proximal tendinous insertions can cause dynamic median nerve compression in the mid forearm [41].

Osseous and Heterotopic Factors: Heterotopic ossification outside the joint capsule can rarely cause median nerve neuropathy [39].

Diagnostic Considerations: Concurrent carpal tunnel syndrome and pronator syndrome are rarely considered, leading to proximal compression sites being easily overlooked [22].

Classification

Pronator Syndrome: Characterized by forearm pain ascribed to median nerve compression, this condition lacks objective tests capable of verifying the diagnosis [17].

Anterior Interosseous Nerve (AIN) Palsy: In contrast to pronator syndrome, AIN palsy presents with objective weakness and electrophysiological abnormalities [17]. The hand exhibits a typical appearance with a characteristic disturbance of pinch [26].

AIN Syndrome: This entity is considered a multifocal mononeuropathy that selectively involves the motor fascicles of the main median nerve trunk, rather than a surgically treatable entrapment neuropathy [20].

Lacertus Syndrome: The term 'lacertus syndrome' should refer specifically to intermittent median nerve compression at the level of the lacertus fibrosus [35].

Bennett’s Syndrome: The pathology originally described by Bennett should be termed chronic exertional compartment syndrome of the pronator teres or 'Bennett's syndrome' [35].

Clinical Presentation

Pronator syndrome is characterized by forearm pain ascribed to median nerve compression [17]. Clinical manifestations of proximal median nerve entrapment in the forearm include aching pain in the anterior forearm [28]. In the absence of motor paralysis, this condition is a clinical diagnosis supported by pain drawings, pain quality, and provocative tests [30]. Clinical suspicion for anterior interosseous nerve (AIN) syndrome should arise in the presence of isolated paralysis of the AIN-supplied muscles [19].

Motor deficits in proximal median nerve entrapment vary substantially in severity and completeness [28]. Patients may present with loss of key and tip pinch strength [28], the typical inability to make an 'OK' sign [28], and loss of fine motor skills accompanied by a sense of clumsiness, including dropping objects [28]. Less frequently, paresthesias in the median nerve innervated region of the hand, similar to carpal tunnel syndrome, may be present [28].

Diagnostic evaluation faces significant limitations. Nerve conduction studies are usually normal and thus unhelpful in the diagnosis of proximal median nerve entrapment [28]. Ultrasound may identify the site of compression by virtue of a change in the diameter of the nerve [28]; however, in the absence of a mass or hematoma, ultrasonography may not be easy to use for diagnosis because fibrous bands or scar tissue may be too small to visualize [28]. There are no objective tests to verify the diagnosis of pronator syndrome, so clinical examination must be relied upon [28].

Differentiation from other pathologies remains challenging. The diagnostic process to differentiate pronator syndrome from carpal tunnel syndrome is difficult due to overlapping symptoms and limited reliable information in the literature [29]. Electrodiagnostic, ultrasound, and MRI are not helpful in making a diagnosis of pronator syndrome concurrent with carpal tunnel syndrome when clinical evaluation is the reference standard [21]. Concurrent carpal tunnel syndrome and pronator syndrome are rarely considered, and proximal compression sites are easily overlooked [22]. Furthermore, there was no correlation between entrapment site and clinical signs on examination in a 55-case surgical series of median nerve entrapment syndrome in the elbow and proximal forearm [23].

The existence of anterior interosseous nerve syndrome, pronator syndrome, superficialis tunnel syndrome, and lacertus tunnel syndrome as individual syndromes has been questioned [28]. Up to four different situations have been identified in proximal median nerve entrapment: anterior interosseous nerve syndrome, pronator syndrome, superficialis tunnel syndrome, and lacertus tunnel syndrome [28]. It is essential for clinicians to have a thorough understanding of median nerve anatomy, possible sites of compression, and characteristic clinical findings of pronator syndrome to provide a reliable diagnosis [10]. It is important to take a complete history and perform a careful examination to avoid confirmation bias when evaluating throwers with medial elbow pain [15].

Investigations

Clinical Evaluation: Clinical suspicion for anterior interosseous nerve syndrome should arise in the presence of isolated paralysis of the AIN-supplied muscles [19]. Surgical indications for nerve decompression in pronator syndrome include persistent symptoms for >6 months [1]. Surgical decompression of the median nerve or the AIN in the forearm is rarely indicated, and a prolonged nonsurgical approach is warranted in most cases [8]. Conservative treatment for at least 6 months is recommended for anterior interosseous nerve syndrome before considering surgery, as compression by normal surrounding tissues may not exist or is very rare [37].

MRI: Pre- and post-exercise MRI can aid in the diagnosis and treatment of lacertus syndrome [14]. With clinical evaluation as the reference standard, electrodiagnostic, ultrasound, and MRI are not helpful in making a diagnosis of pronator syndrome concurrent with carpal tunnel syndrome [21].

Treatment

Non-Operative

Conservative management, including rest, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids, usually suffices and has been effective in 50 - 70% of patients with pronator syndrome [33]. Surgical decompression of the median nerve or the AIN in the forearm is rarely indicated; a prolonged nonsurgical approach is warranted in most cases [8].

Operative

Indications: Surgical indications for nerve decompression include persistent symptoms for >6 months in patients with pronator syndrome [1]. Surgical indications for nerve decompression include a minimum of 12 months with no signs of motor improvement in patients with anterior interosseous nerve syndrome [1].

Surgical Approach / Technique: The endoscopically assisted, minimally invasive approach to treat pronator syndrome adequately and safely decompressed all anatomical points of compression and improved DASH scores [6]. The author is a proponent of the endoscopic technique for pronator syndrome due to minimal damage and foresees its wide indication in the future [3]. Minimally invasive endoscopic decompression for anterior interosseous nerve syndrome can lead to clinical improvement beginning on the first postoperative day, with normalization of thumb and index finger range of movement at nearly 2 years postoperatively [18].

Surgical release in local anesthesia allows for a safe, ambulatory, and cost-efficient procedure with low morbidity for proximal median nerve entrapment at the elbow [32]. The pronator teres release was more invasive, required more complicated surgical skills, deeper dissection, and more invasive anesthetic preparation compared to other techniques [9]. The authors recommend taking a more aggressive approach to lacertus release or resection in chronic cases where chronic scar tissue is encountered or significant postoperative swelling is expected [31].

Anatomical Considerations: Dissection along the ulnar side of the median nerve can possibly decrease the chance of injury to the AIN during decompression [12]. There was no correlation between entrapment site and clinical signs on examination in a 55-case surgical series with a mean 7 years’ follow-up [23].

Complications

Surgical Complexity: Pronator teres release is more invasive than alternative techniques and requires more complicated surgical skills, deeper dissection, and more invasive anesthetic preparation [9].

Inadequate Decompression / Misdiagnosis: Failure of pronator syndrome surgery is attributed to inadequate decompression or misdiagnosis [46].

Patient Dissatisfaction: A substantial proportion of patients treated surgically for nerve entrapments in the proximal forearm were not satisfied with the outcome [48].

Recovery

Light activity (weeks): Operative treatment is indicated if no signs of spontaneous recovery appear within 12 weeks in anterior interosseous nerve syndrome [43]. Following mini-invasive decompression, pronator teres symptoms disappeared in 93% of cases [2]. Surgical release of the lacertus fibrosis effectively relieves pressure over the pronator, allowing the patient to resume previous activities [14]. Acute compression of the median nerve from a proximally displaced and tethered lacertus fibrosus is well treated by surgical release of the lacertus fibrosus [25].

Full activity (months): The pronator teres release is more invasive, requiring more complicated surgical skills, deeper dissection, and more invasive anesthetic preparation compared to other approaches [9].

Complete recovery / outcome plateau (months): Clinical resolution of pronator teres symptoms occurs in 93% of cases following mini-invasive decompression [2].

Rehabilitation protocol: Specific rehabilitation protocols, immobilisation durations, or weight-bearing restrictions are not detailed in the current evidence base.

Functional milestones: Outcome data is limited to symptom resolution rates; validated PROM trajectories or specific outcome-measure benchmarks are not provided.

Other Considerations: The choice of surgical approach impacts invasiveness; the pronator teres release requires more complex skills and deeper dissection than alternative approaches [9].

Key Evidence

  • [Paper] Surgical indications for nerve decompression include persistent symptoms for >6 months in patients with pronator syndrome or for a minimum of 12 months with no signs of motor improvement in those with anterior interosseous nerve syndrome. [1] (10.5435/jaaos-21-05-268)
  • [L4] Pronator teres symptoms disappeared in 93% of cases following the mini-invasive technique. [2] (10.1016/j.jhsa.2012.05.033)
  • [L4] The author is a proponent of the endoscopic technique with minimal damage and foresees its wide indication in the future for pronator syndrome. [3] (10.1177/17531934221076298)
  • [L5] The diagnosis of pronator syndrome lacks objective pathophysiology and is supported only by subjective operative findings and relief after surgery, with a paucity of controlled trials demonstrating that operative treatment is more effective than other treatments or sham surgery. [4] (10.1016/j.jhsa.2011.02.014)
  • [L5] Conservative management, including avoidance of aggravating activities, rest, and anti-inflammatory medication, is recommended for pronator syndrome and anterior interosseous nerve syndrome; surgery is appropriate if symptoms persist. [5] (10.1016/j.jhsa.2009.10.017)
  • [L4] The endoscopically assisted, minimally invasive approach to treat pronator syndrome adequately and safely decompressed all anatomical points of compression and improved DASH scores. [6] (10.1016/j.jhsa.2012.02.023)
  • [Case_report] Resection of a segment of the persistent median artery is the recommended treatment for pronator syndrome associated with this anomaly. [7] (10.2106/00004623-198769020-00026)
  • [L5] Surgical decompression of the median nerve or the AIN in the forearm is rarely indicated; a prolonged nonsurgical approach is warranted in most cases. [8] (10.5435/jaaos-d-16-00010)
  • [L4] The pronator teres release was more invasive and required more complicated surgical skills, deeper dissection, and more invasive anesthetic preparation. [9] (10.1051/sicotj/2016006)
  • [L5] It is essential for clinicians to have a thorough understanding of median nerve anatomy, possible sites of compression, and characteristic clinical findings of pronator syndrome to provide a reliable diagnosis and treat their patients. [10] (10.1016/j.jhsa.2020.07.006)
  • [L5] Lacertus syndrome and superficialis-pronator syndrome should be clearly presented as distinct targets for surgical release, and the term pronator syndrome should be replaced with superficialis-pronator syndrome. [11] (10.1177/17531934211024092)
  • [L5] Dissection along the ulnar side of the median nerve can possibly decrease the chance of injury to the AIN during decompression. [12] (10.1007/s11552-014-9639-5)
  • [L5] Surgical release of the lacertus fibrosis can effectively relieve the pressure over the pronator and allow the patient to resume previous activities. [14] (10.1016/j.radcr.2021.02.022)
  • [L5] It is important to take a complete history and perform a careful examination to avoid confirmation bias when evaluating throwers with medial elbow pain. [15] (10.1016/j.csm.2020.03.004)
  • [L5] [17] (10.1016/j.jhsa.2010.08.018)
  • [L4] [18] (10.1016/j.jhsa.2013.07.026)
  • [L5] Clinical suspicion should arise in the presence of isolated paralysis of the AIN-supplied muscles. [19] (10.1016/j.ijscr.2016.02.021)
  • [L4] Our data strongly support that AINS in the majority of cases is not a surgically treatable entrapment neuropathy but a multifocal mononeuropathy selectively involving, within the main trunk of the median nerve, the motor fascicles that continue distally to form the anterior interosseous nerve. [20] (10.1212/wnl.0000000000000128)
  • [L4] With clinical evaluation as the reference standard, electrodiagnostic, ultrasound, and MRI are not helpful in making a diagnosis of pronator syndrome concurrent with carpal tunnel syndrome. [21] (10.1016/j.jhsa.2020.06.006)
  • [L4] Concurrent carpal tunnel syndrome and pronator syndrome are rarely considered and proximal compression sites are easily overlooked. [22] (10.1016/j.otsr.2016.10.009)
  • [Paper] There was no correlation between entrapment site and clinical signs on examination. [23] (10.1016/j.otsr.2021.102825)
  • [L4] These constrictions were identified in all MRN cases and 88% of ultrasound cases, predominantly in the posterior/posteromedial region proximal to the elbow joint line. [24] (10.1002/mus.26768)
  • [L4] Acute compression of the median nerve from the proximally displaced and tethered lacertus fibrosus appears to cause the resultant dynamic compression of the median nerve and is well treated by surgical release of the lacertus fibrosus. [25] (10.1016/j.jse.2006.04.005)
  • [L4] [28] (10.1177/1753193417726214)
  • [L4] The diagnostic process to differentiate pronator syndrome from carpal tunnel syndrome remains a challenge due to overlapping symptoms and limited reliable information in the literature; this review provides a comprehensive clinical comparison to aid in establishing appropriate diagnosis and treatment. [29] (10.3390/diagnostics12102433)
  • [L4] Median nerve entrapment in the forearm without motor paralysis is a clinical diagnosis supported by pain drawings, pain quality, and provocative tests. [30] (10.1177/1558944719874137)
  • [Case_report] The authors recommend taking a more aggressive approach to lacertus release or resection in chronic cases where chronic scar tissue is encountered or significant postoperative swelling is expected. [31] (10.1016/j.xrrt.2024.08.009)
  • [L4] Surgical release in local anesthesia allows for a safe, ambulatory, and cost-efficient procedure with low morbidity. [32] (10.1007/s11552-012-9483-4)
  • [L5] Conservative management, including rest, non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids, usually suffice and has been effective in 50 - 70% of patients. [33] (10.1097/phm.0000000000000973)
  • [L5] The authors recommend that the term 'lacertus syndrome' refer to intermittent median nerve compression at the level of the lacertus fibrosus, while the pathology originally described by Bennett should be termed chronic exertional compartment syndrome of the pronator teres or 'Bennett's syndrome' to resolve current terminology confusion. [35] (10.1177/17531934231170347)
  • [Paper] The study inventoried and mapped 6 potentially compressive structures neighboring or crossing the median nerve, showing precise proximal-to-distal locations with variations of 0.5 to 1.5 cm. [36] (10.1016/j.otsr.2021.102813)
  • [L5] Compression of the anterior interosseous nerve by normal surrounding tissues may not exist or is very rare, with most cases likely representing neuritis; conservative treatment for at least 6 months is recommended before considering surgery. [37] (10.1177/17531934221074903)
  • [L5] The ulnar head of the pronator teres is fibrotic or fibromuscular in 71.5% of cases, and its morphology and location relative to the median nerve are important for surgical treatment of pronator syndrome. [38] (10.1016/j.otsr.2016.08.016)
  • [Case_report] Although heterotopic ossification is a common complication of elbow injuries, it rarely causes compressive neuropathy; this case reports a unique instance of median nerve neuropathy caused by heterotopic ossification outside the joint capsule. [39] (10.1177/1753193413518692)
  • [L5] A case of median nerve entrapment at the elbow by a non-osseous fibrous ligament (Struthers) is presented. [40] (10.3171/jns.1973.38.6.0778)
  • [L5] This case describes the first reported case of a palmaris longus variant with a central muscle belly and both distal and proximal tendinous insertions causing median nerve compression in a dynamic fashion at the mid forearm level. [41] (10.1016/j.bjps.2012.03.023)
  • [L4] If no signs of spontaneous recovery appear within 12 weeks, operative treatment should be performed. [43] (10.1007/s00402-011-1322-5)
  • [L4] Although the majority of the patients benefited from the operation, a substantial proportion was not satisfied. [48] (10.4061/2011/727689)

References

[1] Pronator Syndrome and Anterior Interosseous Nerve Syndrome. Journal of the American Academy of Orthopaedic Surgeons. 2013. DOI: 10.5435/jaaos-21-05-268

[2] New Mini-invasive Decompression for Pronator Teres Syndrome. The Journal of Hand Surgery. 2012. DOI: 10.1016/j.jhsa.2012.05.033

[3] Re: Tang JB. Median nerve compression: lacertus syndrome versus superficialis-pronator syndrome. J Hand Surg Eur. 2021, 46: 1017–22. Journal of Hand Surgery (European Volume). 2022. DOI: 10.1177/17531934221076298

[4] Pronator Syndrome. The Journal of Hand Surgery. 2011. DOI: 10.1016/j.jhsa.2011.02.014

[5] Unusual Compression Neuropathies of the Forearm, Part II: Median Nerve. The Journal of Hand Surgery. 2009. DOI: 10.1016/j.jhsa.2009.10.017

[6] Endoscopically Assisted Decompression for Pronator Syndrome. The Journal of Hand Surgery. 2012. DOI: 10.1016/j.jhsa.2012.02.023

[7] Pronator syndrome associated with a persistent median artery. A case report.. The Journal of Bone & Joint Surgery. 1987. DOI: 10.2106/00004623-198769020-00026

[8] Ulnar Tunnel Syndrome, Radial Tunnel Syndrome, Anterior Interosseous Nerve Syndrome, and Pronator Syndrome. Journal of the American Academy of Orthopaedic Surgeons. 2017. DOI: 10.5435/jaaos-d-16-00010

[9] Role of pronator release in revision carpal tunnel surgery. SICOT-J. 2016. DOI: 10.1051/sicotj/2016006

[10] Proximal Median Nerve Compression: Pronator Syndrome. The Journal of Hand Surgery. 2020. DOI: 10.1016/j.jhsa.2020.07.006

[11] Median nerve compression: lacertus syndrome versus superficialis-pronator syndrome. Journal of Hand Surgery (European Volume). 2021. DOI: 10.1177/17531934211024092

[12] Median Nerve Compression at the Fibrous Arch of the Flexor Digitorum Superficialis: An Anatomic Study of the Pronator Syndrome. HAND. 2014. DOI: 10.1007/s11552-014-9639-5

[14] Lacertus syndrome: Use of pre- and post-exercise MRI to aid in diagnosis and treatment. Radiology Case Reports. 2021. DOI: 10.1016/j.radcr.2021.02.022

[15] The Lacertus Syndrome of the Elbow in Throwing Athletes. Clinics in Sports Medicine. 2020. DOI: 10.1016/j.csm.2020.03.004

[17] Anterior Interosseous Nerve Syndrome. The Journal of Hand Surgery. 2010. DOI: 10.1016/j.jhsa.2010.08.018

[18] Minimally Invasive Endoscopic Decompression for Anterior Interosseous Nerve Syndrome: Technical Notes. The Journal of Hand Surgery. 2013. DOI: 10.1016/j.jhsa.2013.07.026

[19] Anterior interosseous nerve syndrome diagnosis and intraoperative findings: A case report. International Journal of Surgery Case Reports. 2016. DOI: 10.1016/j.ijscr.2016.02.021

[20] Anterior interosseous nerve syndrome. Neurology. 2014. DOI: 10.1212/wnl.0000000000000128

[21] Clinical, Radiological, and Electrodiagnostic Diagnosis of Pronator Syndrome Concurrent With Carpal Tunnel Syndrome. The Journal of Hand Surgery. 2020. DOI: 10.1016/j.jhsa.2020.06.006

[22] Concurrent carpal tunnel syndrome and pronator syndrome: A retrospective study of 21 cases. Orthopaedics & Traumatology: Surgery & Research. 2017. DOI: 10.1016/j.otsr.2016.10.009

[23] Median nerve entrapment syndrome in the elbow and proximal forearm. Anatomic causes and results for a 55-case surgical series at a mean 7 years’ follow-up. Orthopaedics & Traumatology: Surgery & Research. 2021. DOI: 10.1016/j.otsr.2021.102825

[24] Fascicular constrictions above elbow typify anterior interosseous nerve syndrome. Muscle & Nerve. 2019. DOI: 10.1002/mus.26768

[25] Acute compression of the median nerve at the elbow by the lacertus fibrosus. Journal of Shoulder and Elbow Surgery. 2007. DOI: 10.1016/j.jse.2006.04.005

[26] The Anterior Interosseous-Nerve Syndrome: WITH SPECIAL ATTENTION TO ITS VARIATIONS.. The Journal of Bone and Joint Surgery. American Volume. 1970.

[28] The scratch collapse test in the diagnosis of compression of the median nerve in the proximal forearm. Journal of Hand Surgery (European Volume). 2017. DOI: 10.1177/1753193417726214

[29] How to Differentiate Pronator Syndrome from Carpal Tunnel Syndrome: A Comprehensive Clinical Comparison. Diagnostics. 2022. DOI: 10.3390/diagnostics12102433

[30] Median Nerve Compression in the Forearm: A Clinical Diagnosis. HAND. 2019. DOI: 10.1177/1558944719874137

[31] Acute median nerve compression secondary to lacertus fibrosis syndrome following distal biceps tendon reconstruction: a case report. JSES Reviews, Reports, and Techniques. 2025. DOI: 10.1016/j.xrrt.2024.08.009

[32] Clinical Diagnosis and Wide-Awake Surgical Treatment of Proximal Median Nerve Entrapment at the Elbow: A Prospective Study. HAND. 2013. DOI: 10.1007/s11552-012-9483-4

[33] Pronator Syndrome: An Uncommon Median Nerve Entrapment Syndrome. American Journal of Physical Medicine & Rehabilitation. 2019. DOI: 10.1097/phm.0000000000000973

[35] Lacertus syndrome: one term – two different pathologies. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231170347

[36] Topographic anatomy of structures liable to compress the median nerve at the elbow and proximal forearm. Orthopaedics & Traumatology: Surgery & Research. 2021. DOI: 10.1016/j.otsr.2021.102813

[37] Compression to the anterior interosseous nerve is very rare: compression by the normal tissues surrounding it may not exist. Journal of Hand Surgery (European Volume). 2022. DOI: 10.1177/17531934221074903

[38] Morphology and morphometry of the ulnar head of the pronator teres muscle in relation to median nerve compression at the proximal forearm. Orthopaedics & Traumatology: Surgery & Research. 2016. DOI: 10.1016/j.otsr.2016.08.016

[39] Early treatment of anterior interosseous nerve palsy with hourglass-like fascicular constrictions by interfascicular neurolysis due to early diagnosis using ultrasonography: A case report. Journal of Hand Surgery (European Volume). 2014. DOI: 10.1177/1753193413518692

[40] Struthers ligament: a source of median nerve compression above the elbow. Journal of Neurosurgery. 1973. DOI: 10.3171/jns.1973.38.6.0778

[41] The dual tendon palmaris longus variant causing dynamic median nerve compression in the forearm. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2012. DOI: 10.1016/j.bjps.2012.03.023

[43] Anterior interosseous nerve syndrome: retrospective analysis of 14 patients. Archives of Orthopaedic and Trauma Surgery. 2011. DOI: 10.1007/s00402-011-1322-5

[46] The pronator teres syndrome: compressive neuropathy of the median nerve.. The Journal of Bone and Joint Surgery. American Volume. 1981.

[48] Patient-Reported Outcome of Surgical Treatment of Nerve Entrapments in the Proximal Forearm. Advances in Orthopedics. 2011. DOI: 10.4061/2011/727689

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a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.