Lacertus syndrome: a ten year analysis of two hundred and seventy five minimally invasive surgical decompressions of median nerve entrapment at the elbow.

PURPOSE: This study aims to assess the clinical presentation and surgical outcomes of lacertus syndrome (LS) and concomitant median nerve entrapments. METHODS: A retrospective study of prospectively collected data was conducted on patients undergoing lacertus release (LR) from June 2012 to June 2021. Available DASH (Disability of the Arm Shoulder Hand questionnaire) scores and post-operative Visual Analogue Scale (VAS) of pain, numbness, subjective satisfaction with surgical outcome, and intra-operative return of strength were analyzed. RESULTS: Two-hundred-seventy-five surgical cases were identified of which 205 cases (74.5%) underwent isolated LR, and 69 cases (25.1%) concomitant lacertus and carpal tunnel release. The three most common presenting symptoms in LS patients were loss of hand strength (95.6%), loss of hand endurance/fatigue (73.3%), and forearm pain (35.4%). Numbness in the median nerve territory of the hand was found in all patients with combined LS and carpal tunnel syndrome. Quick-DASH significantly improved (pre-operative 34.4 (range 2.3-84.1) to post-operative 12.4 (range 0-62.5), p < 0.0001) as did work and activity DASH (p < 0.0001). The postoperative VAS scores were pain VAS 1.9 and numbness VAS 1.8. Eighty-eight percent of patients reported good/excellent satisfaction with the surgical outcome. Intra-operative return of strength was verified in 99.2% of cases. CONCLUSION: LS is a common median nerve compression syndrome typically presenting with loss of hand strength and hand endurance/fatigue. Minimally invasive LR immediately restores hand strength, significantly improves DASH scores, and yields positive outcomes regarding VAS pain, numbness, and subjective satisfaction with surgery in patients with proximal median nerve entrapment at a minimum six month follow-up.

Median nerve entrapments in the forearm - a case report of rare anterior interosseous nerve syndrome.

Nowadays, median nerve entrapment is a frequent issue. Many physicians are familiar with the most common median entrapment, which is the carpal tunnel syndrome (CTS). By contrast, less frequent entrapments, historically called "pronator syndrome" are still misdiagnosed as overuse syndrome, flexor tendinitis or other conditions. This article is meant to introduce proximal median nerve entrapments, followed by a case report of the rarest example - anterior interosseous nerve syndrome (AIN syndrome).

Proximal Median Nerve Compression: Pronator Syndrome.

Pronator syndrome (PS) is a compressive neuropathy of the median nerve in the proximal forearm, with symptoms that often overlap with carpal tunnel syndrome (CTS). Because electrodiagnostic studies are often negative in PS, making the correct diagnosis can be challenging. All patients should be initially managed with nonsurgical treatment, but surgical intervention has been shown to result in satisfactory outcomes. Several surgical techniques have been described, with most outcomes data based on retrospective case series. It is essential for clinicians to have a thorough understanding of median nerve anatomy, possible sites of compression, and characteristic clinical findings of PS to provide a reliable diagnosis and treat their patients.

Distal nerve transfer for thenar palsy: A cadaveric study.

INTRODUCTION: Severe proximal median nerve palsies often result in irreversible thenar atrophy and thumb abduction function loss. Tendon transfer involves substantial limitations and challenges; but, distal nerve transfer may provide an alternative treatment. Our goal was to validate the anatomical suitability of two distal ulnar nerve branches for thenar muscle reanimation. MATERIALS AND METHODS: We assessed nerve transfer to the recurrent branch of median nerve (RMN) in 16 embalmed cadaveric hands. The ulnar motor branch to the flexor digiti minimi brevis (FDMBn) and the ulnar motor branch to the third lumbrical (3rdLn) were assessed for transfer. Coaptation success was measured by the overlap of the nerve donor with the RMN and correspondence of nerve diameters. RESULTS: The mean transferable length and width of the RMN were 20.7 ± 4.5 and 1.0 ± 0.3 mm, respectively. We identified an average of three branches in the branching anatomy from the ulnar nerve to the hypothenar muscles. The maximal transferable lengths and widths of the FDMBn and the 3rdLn were 13.8 ± 4.4 and 0.5 ± 0.1 mm and 24.1 ± 6.4 and 0.4 ± 0.1 mm, respectively. The overlap with the RMN of the FDMBn and 3rdLn was 9.0 ± 3.6 (2.0-15.3) and 17.8 ± 6.0 (4.7-27.5) mm, respectively. CONCLUSIONS: This anatomical study demonstrates the feasibility of distal nerve transfers between the ulnar and median nerves in the hand for reanimation of thenar muscles. Ulnar motor donors of the BrFDMBn and 3rdLn likely represent the least morbid donors with short distances for regeneration and a single coaptation repair.

Sensory perturbations using suture and sutureless repair of transected median nerve in rats.

The effects of changes to cold, mechanical, and heat thresholds following median nerve transection with repair by sutures (Su) or Rose Bengal adhesion (RA) were compared to sham-operated animals. Both nerve-injured groups showed a transient, ipsilateral hyposensitivity to mechanical and heat stimuli followed by a robust and long-lasting hypersensitivity (6-7 weeks) with gradual recovery towards pre-injury levels by 90 days post-repair. Both tactile and thermal hypersensitivity were seen in the contralateral limb that was similar in onset but differed in magnitude and resolved more rapidly compared to the injured limb. Prior to injury, no animals showed any signs of aversion to cold plate temperatures of 4-16 °C. After injury, animals showed cold allodynia, lasting for 7 weeks in RA-repaired rats before recovering towards pre-injury levels, but were still present at 12 weeks in Su-repaired rats. Additionally, sensory recovery in the RA group was faster compared to the Su group in all behavioural tests. Surprisingly, sham-operated rats showed similar bilateral behavioural changes to all sensory stimuli that were comparable in onset and magnitude to the nerve-injured groups but resolved more quickly compared to nerve-injured rats. These results suggest that nerve repair using a sutureless approach produces an accelerated recovery with reduced sensorimotor disturbances compared to direct suturing. They also describe, for the first time, that unilateral forelimb nerve injury produces mirror-image-like sensory perturbations in the contralateral limb, suggesting that the contralateral side is not a true control for sensory testing. The potential mechanisms involved in this altered behaviour are discussed.

Reappraisal of Clinical Deficits Following High Median Nerve Injuries.

PURPOSE: To describe clinically apparent motor and sensory deficits in a cohort of 11 patients with isolated injury of the median nerve above the elbow and compare them against similar cases reported in the literature. METHOD: Eleven patients of mean age 30 years (SD ± 14 years; 6 males, 5 females) were examined a mean of 21 weeks (SD ± 16 weeks) after an isolated high median nerve injury. Pronation, wrist flexion, and finger flexion range of motion and strength (British Medical Research Council scale) were evaluated. Grasp and lateral pinch strength were assessed bilaterally using a dynamometer. Thumb opposition was evaluated using the Kapandji score. Sensory impairment was considered significant when there was no perception of a 2.0-g Semmes-Weinstein filament. RESULTS: Pronation was largely preserved in all patients to a mean range of motion of 52° (SD ± 13°), and pronation strength was M4 in 10 of 11 patients. Wrist flexion scored M5 in all patients. Thumb and index distal interphalangeal joint flexion were absent in all patients. In all patients, middle, ring, and little finger flexion was complete and scored M5. Thumb function scored above 5 in all patients, averaging 7.5 (SD ± 1.2) on the Kapandji scale. Grasp and pinch strength were 43% (SD ± 12%) and 36% (SD ± 11%) of the contralateral (normal) limb, respectively. Impaired sensation of a 2.0-g monofilament was found only in the palmar region over the middle and distal phalanges of the index and middle fingers and the distal phalanx of the thumb. CONCLUSIONS: Noteworthy discrepancies were identified between the clinical motor and sensory deficits described in the literature and those observed in our patients. CLINICAL RELEVANCE: In most patients with a high median nerve injury, only thumb and index flexion and palmar sensation warrant surgical reconstruction. Decreased grasp and pinch strength was a major finding that should also be addressed by surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Brachialis syndrome: a rare consequence of patient positioning causing postoperative median neuropathy.

BACKGROUND: Poor positioning of patients can result in devastating permanent neurologic deficits. We describe a previously unreported cause of median nerve compression that we have termed the brachialis syndrome, associated with patient positioning that results in permanent median nerve damage. METHODS: We identified this condition affecting 6 median nerves. All patients underwent surgical decompression of the proximal median nerve at the level of the antecubital fossa. RESULTS: Five patients presented with symptoms of median nerve compression; 6 affected median nerves manifested brachialis syndrome after a lengthy index surgery. Every patient had a similar presentation characterized by a mixed sensory and motor deficit. Average time to symptom presentation postoperatively was 1 hour. Two patients had delayed time to decompression, one of 25 days and one of 92 days. In the additional patients, the average time to decompression was 19.7 hours. At median nerve decompression, the brachialis was found to have varying degrees of muscle necrosis. In the patients whose decompression was delayed, there was only partial neurologic recovery at follow-up to 1 year. In the patients expeditiously decompressed, full neurologic recovery occurred in 1 to 14 days. CONCLUSIONS: This is the first description of the brachialis syndrome. During surgery, arms were placed into full extension, compressing the brachialis against the trochlea. The brachialis reliably developed necrosis, resulting in swelling, compressing the median nerve against the lacertus fibrosus. Two patients with delayed decompression had poor neurologic outcomes. This supports modification of patient positioning, postoperative vigilance, and timely surgical management of brachialis syndrome.

[Nerve injuries after elbow luxation fractures in childhood : Indication and timing for surgical revision]. / Nervenverletzungen nach Ellenbogenluxationsfraktur im Kindesalter : Indikation und Zeitpunkt zur operativen Revision.

BACKGROUND: Supracondylar humerus fractures are very common in pediatric populations. In cases of dislocated fractures, closed reduction and percutaneous K­wire fixation is recommended. Initially, 10-16 % of the patients also present lesion of the ulnar nerve as well as median nerve palsy in 6.4% and radial nerve palsy in 2.6 % of cases, respectively. METHOD: We present the case of a 10-year-old boy with a dislocation of the elbow and fracture of the medial epicondyle. After closed reduction and K­wire fixation from medial, he presents a median nerve palsy. That a lesion of the ulnar nerve is also present is only noticed 3½ years posttraumatically. A surgical decompression and neurolysis of the ulnar and median nerve is performed and the postoperative grip and key strength presented. DISCUSSION: With the help of the presented case we discuss the indication and the point of surgical revision. Clinical assessment and neurosonography are essential for an exact diagnosis.

Neurovascular compromise due to true brachial artery aneurysm at the site of a previously ligated arteriovenous fistula: Case report and review of literature.

True arterial aneurysms of the upper extremity are rare. The case described is that of a 48-year-old man presenting with median neuropathy and distal vascular compromise 4 years after ligation of a brachiocephalic arteriovenous fistula. We describe our approach and present a review of the relevant literature.

Transfer of the radial nerve branch to the extensor carpi radialis brevis to the anterior interosseous nerve to reconstruct thumb and finger flexion.

PURPOSE: To report our experiences reconstructing thumb and finger flexion in patients with extensive palsy of the upper limb by transferring the radial nerve branch to the extensor carpi radialis brevis (ECRB) to the anterior interosseous nerve (AIN). METHODS: Within 8 months after injury, 4 patients with either a combined high median/ulnar nerve palsy or C7-T1 brachial plexus root avulsion underwent surgical reconstruction for thumb and finger flexion. As part of the reconstructive procedure, the branch of the radial nerve to the ECRB was transferred to the AIN. RESULTS: At final evaluation, which averaged 13 months postoperatively, all patients had recovered full finger and thumb flexion, scoring M4 per Medical Research Council guidelines. Average grasp strength was 5 kg, and pinch strength was 2 kg. Even in anesthetic fingers and with their eyes closed, patients could correctly identify passive extension of their distal interphalangeal joints. Wrist extension was preserved in all patients. CONCLUSIONS: In 4 patients, transfer of the branch of the radial nerve to the ECRB to the AIN predictably reconstructed thumb and finger flexion. Finger flexion also recovered in those fingers in which the flexor digitorum profundus was primarily innervated by the ulnar nerve. Despite extended sensory deficits, patients ultimately were able to use their hands regularly in daily life. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Cervical radiofrequency neurotomy reduces central hyperexcitability and improves neck movement in individuals with chronic whiplash.

OBJECTIVE: This study aims to determine if cervical medial branch radiofrequency neurotomy reduces psychophysical indicators of augmented central pain processing and improves motor function in individuals with chronic whiplash symptoms. DESIGN: Prospective observational study of consecutive patients with healthy control comparison. SETTING: Tertiary spinal intervention centre in Calgary, Alberta, Canada. SUBJECTS: Fifty-three individuals with chronic whiplash associated disorder symptoms (Grade 2); 30 healthy controls. METHODS: Measures were made at four time points: two prior to radiofrequency neurotomy, and 1- and 3-months post-radiofrequency neurotomy. Measures included: comprehensive quantitative sensory testing (including brachial plexus provocation test), nociceptive flexion reflex, and motor function (cervical range of movement, superficial neck flexor activity during the craniocervical flexion test). Self-report pain and disability measures were also collected. One-way repeated measures analysis of variance and Friedman's tests were performed to investigate the effect of time on the earlier measures. Differences between the whiplash and healthy control groups were investigated with two-tailed independent samples t-test or Mann-Whitney tests. RESULTS: Following cervical radiofrequency neurotomy, there were significant early (within 1 month) and sustained (3 months) improvements in pain, disability, local and widespread hyperalgesia to pressure and thermal stimuli, nociceptive flexor reflex threshold, and brachial plexus provocation test responses as well as increased neck range of motion (all P < 0.0001). A nonsignificant trend for reduced muscle activity with the craniocervical flexion test (P > 0.13) was measured. CONCLUSIONS: Attenuation of psychophysical measures of augmented central pain processing and improved cervical movement imply that these processes are maintained by peripheral nociceptive input.

Median nerve neuropraxia by a large false brachial artery aneurysm.

Peripheral nerve compression is a rare complication of an iatrogenic false brachial artery aneurysm. We present a 72-year-old patient with median nerve compression due to a false brachial artery aneurysm after removal of an arterial catheter. Surgical exclusion of the false aneurysm was performed in order to release traction of the median nerve. At 3-month assessment, moderate hand recovery in function and sensibility was noted. In the case of neuropraxia of the upper extremity, following a history of hospital stay and arterial lining or catheterization, compression due to pseudoaneurysm should be considered a probable cause directly at presentation. Early recognition and treatment is essential to avoid permanent neurological deficit.

Free anterolateral thigh flap with vascularized lateral femoral cutaneous nerve for the treatment of neuroma-in-continuity and recurrent carpal tunnel syndrome after carpal tunnel release.

Treatment of recurrent carpal tunnel syndrome (CTS) is challenging, especially in a case with recurrent CTS and a neuroma formation. Resection of the neuroma causing the syndrome, reconstruction of the nerve gap of the median nerve, and covering up the reconstructed median nerve with well-vascularized soft tissue for prevention of CTS re-recurrence are the essential procedures. We report a case of recurrent CTS with severe pain due to a neuroma-in-continuity successfully treated using a free anterolateral thigh (ALT) flap with a vascularized lateral femoral cutaneous nerve (LFCN). A 2 cm neuroma existed in the median nerve and was resected. The nerve gap was repaired using a vascularized LFCN included in the ALT flap. The ALT flap was transferred to the wrist to cover the median nerve. The severe pain disappeared completely and the sensory and motor impairment of the median nerve improved 5 months after the free flap surgery, as the Tinel's sign moved distally away from the wrist and disappeared. The result of the Semmes-Weinstein test improved from 5.08 to 4.31 and she was able to flex and extend the right wrist and fingers without pain. CTS did not recur 15 months after the surgery. A free ALT flap with vascularized LFCN allows nerve reconstruction for the median nerve gap created after neuroma resection and coverage of the median nerve with well-vascularized soft tissue to prevent adhesion and CTS recurrence.

[A rare tumor of the median nerve in a young child: Intraneural perineurioma. About one clinical case]. / Une tumeur rare du nerf médian chez le jeune enfant : le périneuriome intraneural. À propos d'un cas clinique.

Intraneural perineurioma is a rare benign peripheral sheath tumor, which is most prevalent in adolescents and young adults. It is characterized by focal perineural cell proliferation infiltrating the endoneurium leading to the macroscopic aspect of hypertrophic nerve. It typically presents a loss of motor function in the involved nerve. We report the case of a 3-year-old boy presented with painless, subcutaneous mass on the palmar aspect of his right hand without loss of motor function. Imaging studies showed a large mass within the median nerve suggesting schwannoma. Surgical exploration was undertaken. The tumor could not be removed without leading to motor and sensitive loss. Neurolysis of the hypertrophic fascicles was performed. Microbiopsies ruled out malignant tumor and could make the diagnosis of intraneural perineurioma of the median nerve. An annual clinical follow-up has been decided in order to detect any functional trouble such as loss of motor function.

[The quadriga syndrome: a rarely recognized alteration in hand surgery]. / Quadrigaszindróma: Ritkán felismert tünetegyüttes a kézsebészetben.

The tendons of flexor digitorum profundus are most often interconnected and making them less able to move independently than the superficial tendons. The reason for this is the cross connective tissue-ligamentous connection between the tendons of the profundus. The recognition of this so called quadriga phenomenon is important in the clinical practice, when the presence of this syndrome hinders the strength and the movement of the tendons after operative reconstruction. In his work the author describes the anatomical foundation, the biomechanical correlations and the clinical importance of the quadriga syndrome in the mirror of literature data.

Visualization of Median Nerve Entrapment After Reduction of an Elbow Fracture Dislocation Using 3-Dimensional Magnetic Resonance Imaging: A Case Report.

CASE: A 10-year-old girl presented after closed reduction of an elbow fracture dislocation. She demonstrated intact vascularity but a dense median nerve palsy. Preoperative magnetic resonance neurography (MRN) precisely mapped the median nerve entrapped within the medial epicondylar fracture. Intraoperatively, the median nerve was freed preceding reduction and fracture fixation. Postoperatively, neurological symptoms completely resolved, and she regained full elbow function. CONCLUSION: Median nerve injury can present without associated vascular injury. In this case, MRN was helpful in preoperatively illustrating the spatial relationship between the median nerve and the medial epicondyle.

Entrapment of Median Nerve After Pediatric Elbow Dislocation with a Brief Review of Literature: A Case Study.

CASE: We present a case of type II (intraosseous) entrapment of the median nerve in a patient who was diagnosed based on clinical examination and magnetic resonance imaging and who was treated with medial epicondyle osteotomy, neurolysis, and transposition of the nerve to its anatomical position within a month of injury. Our patient made a complete motor and sensory recovery at 5 months with complete functionality and grip strength. CONCLUSION: Median nerve entrapment after posterolateral elbow dislocation is a rare complication with roughly 40 cases reported in the literature. This case illustrates the importance of prompt diagnosis and treatment.

Pronator syndrome and anterior interosseous nerve syndrome.

Dysfunction of the median nerve at the elbow or proximal forearm can characterize two distinct clinical entities: pronator syndrome (PS) or anterior interosseous nerve (AIN) syndrome. PS is characterized by vague volar forearm pain, with median nerve paresthesias and minimal motor findings. AIN syndrome is a pure motor palsy of any or all of the muscles innervated by that nerve: the flexor pollicis longus, the flexor digitorum profundus of the index and middle fingers, and the pronator quadratus. The sites of anatomic compression are essentially the same for both disorders. Typically, the findings of electrodiagnostic studies are normal in patients with PS and abnormal in those with AIN syndrome. PS is a controversial diagnosis and is typically treated nonsurgically. AIN syndrome is increasingly thought to be neuritis and it often resolves spontaneously following prolonged observation. Surgical indications for nerve decompression include persistent symptoms for >6 months in patients with PS or for a minimum of 12 months with no signs of motor improvement in those with AIN syndrome.

Tendon transfers for radial, median, and ulnar nerve palsy.

Tendon transfers are used to restore balance and function to a paralyzed, injured, or absent neuromuscular-motor unit. In general, tendon transfer is indicated for restoration of muscle function after peripheral nerve injury, injury to the brachial plexus or spinal cord, or irreparable injury to tendon or muscle. The goal is to improve the balance of a neurologically impaired hand. In the upper extremity, tendon transfers are most commonly used to restore function following injury to the radial, median, and ulnar nerves. An understanding of the general principles of tendon transfer is important to maximize the outcome.

Split flexor pollicis longus tendon transfer to A1 pulley for correction of paralytic Z deformity of the thumb.

PURPOSE: To test the hypothesis that split flexor pollicis longus (FPL) transfer to the A1 pulley will correct a thumb paralytic Z deformity and that the transfer can be subjected to early postoperative active mobilization protocol. METHODS: In a prospective trial, 19 consecutive thumbs with ulnar or combined ulnar and median nerve paralysis received split FPL transfer to the thumb A1 pulley and active mobilization of transfer after 48 hours. Outcomes were assessed by correction of Z deformity during pinch, tendon transfer insertion pullout during early active mobilization, range of motion at the thumb metacarpophalangeal and interphalangeal joints, and postoperative treatment time. Data from historical records of 20 thumbs with split FPL to extensor pollicis longus (EPL) and 3 weeks' immobilization, treated before the prospective trial in the same institution, were used for comparison. RESULTS: All 19 thumbs with split FPL to A1 pulley achieved Z deformity correction at discharge from rehabilitation. There was no incidence of transfer insertion pullout during active mobilization, and patients were discharged 22 days earlier than the controls who received transfer of FPL to EPL insertion. Seventeen thumbs were available for follow-up more than 1 year after the index procedure. Fifteen thumbs retained deformity correction, and 2 had recurrence of Z deformity. The interphalangeal joint had considerably greater active motion following split FPL to A1 pulley compared with transfer of split FPL to EPL insertion. CONCLUSIONS: This study supports the hypothesis. Split FPL tendon transfer to thumb A1 pulley can correct paralytic thumb Z deformities and be mobilized early for transfer re-education. Improved interphalangeal joint active motion and reduced treatment time are added advantages over FPL transfer to the EPL insertion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.