TREATMENT OF IRRECOVERABLE RADIAL NERVE PALSY USING THE MODIFIED MERLE D'AUBIGNÉ TENDON TRANSFER METHOD.

Background: Irrecoverable radial nerve palsy (RNP) leads to the inability to extend the wrist and fingers and significant reduction in grip strength. The aim was to assess the outcomes of treating non-recovering motor RNP using the modified Merle d'Aubigné tendon transfer method. Materials and Methods: A descriptive prospective study involved 33 patients between January 2017 and March 2019. Results: Males constituted the majority (32/33 cases, 97%). The ratio of radial nerve and posterior interosseous nerve injuries was nearly equivalent (16/17). The mean extension range of the wrist was 48.6° ± 14.9° during finger extension and 30.9° ± 14.4° during finger flexion. The mean flexion range of the wrist was 34.8° ± 15.8° during finger extension and 42.6° ± 14.8° during finger flexion. 93.9% of patients achieved full finger extension when the wrist joint was extended beyond 10°. The mean angulation range of the index finger was 55.3° ± 7.4°. The Kapanji score achieved was 8.4 ± 1.2. The achieved grip strength was 65.4% compared to the unaffected side. The surgery did not induce radial deviation deformities of the wrist joint. 32/33 patients were satisfied with the surgical outcomes. 31/33 patients returned to their previous professions. 93.9% of patients achieved very good and good results, while 6.1% achieved fair results. Conclusion: Treating irrecoverable radial nerve palsy using the modified Merle d'Aubigné tendon transfer method yields very good results. The utilization of the pronator teres for wrist extensor transfer and the flexor carpi radialis for finger extensor transfer is appropriate and contributes to limiting wrist joint radial deviation deformities. This modified technique has been researched and recommended by various authors worldwide.

Neuralgic Amyotrophy and Hourglass Nerve Constriction/Nerve Torsion: Two Sides of the Same Coin? A Clinical Review.

Neuralgic amyotrophy, also called Parsonage-Turner syndrome, in its classic presentation is a brachial plexopathy or a multifocal neuropathy, involving mainly motor nerves of the upper limb with a monophasic course. Recently, a new radiological entity was described, the hourglass constriction, which is characterized by a very focal constriction of a nerve, or part of it, usually associated with nerve thickening proximally and distally to the constriction. Another condition, which is similar from a radiological point of view to hourglass constriction, is nerve torsion. The pathophysiology of neuralgic amyotrophy, hourglass constriction and nerve torsion is still poorly understood, and a generic role of inflammation is proposed for all these conditions. It is now widely accepted that nerve imaging is necessary in identifying hourglass constrictions/nerve torsion pre-surgically in patients with an acute mononeuropathy/plexopathy. Ultrasound and MRI are useful tools for diagnosis, and they are consistent with intraoperative findings. The prognosis is generally favorable after surgery, with a high rate of good motor recovery.

Distal biceps tendon rupture: a comprehensive overview.

Distal biceps tendon (DBT) is a relatively rare injury mainly occurring in middle-aged men while in eccentric biceps muscle contraction. Clinical appearance with proximal avulsion of the muscle and specific clinical tests are most of the time sufficient for diagnosing DBT, but if needed ultrasonography and MRI, most often in FABS view, can be used to ensure diagnosis of DBT and partial DBT. Surgical anatomical reinsertion has shown to be a successful method of treatment, although conservative treatment can be initiated in older patients. Two different approaches are described in literature: single- and double-incision techniques with different fixation methods proving to have similarly good results. Major complications of surgical intervention are posterior interosseous nerve palsy and symptomatic heterotropic ossification. Overall outcome of surgical intervention has shown high subjective satisfaction with slight weakness in flexion and supination but mostly without loss in range of motion.

A Case of Posterior Interosseous Nerve Palsy Associated With Robotic Low Anterior Resection.

A peripheral nerve compression injury associated with surgical positioning is an important complication that might compromise quality of life. We report a rare case of posterior interosseous nerve (PIN) palsy after robotic rectal cancer surgery. A 79-year-old male with rectal cancer underwent robotic low anterior resection in a modified lithotomy position with both arms tucked at his sides with bed sheets. Following surgery, he felt difficulty moving his right wrist and fingers. A neurological examination revealed muscle weakness in the area innervated by the PIN alone without sensory disturbance, and he was diagnosed with PIN palsy. The symptoms improved with conservative treatment in about a month. The PIN is a branch of the radial nerve and controls dorsiflexion of the fingers, and intraoperative continuous pressure on the upper arm by right lateral rotation position or by the robot arm was considered to be the cause.

Tendon Transfer for Correction of the Radial Deviation Deformity of the Wrist and Centralization in Posterior Interosseous Nerve Palsy.

There are very few descriptions of tendon transfers designed specifically to address the reconstruction of posterior interosseous nerve palsy (PINP). Unlike a radial nerve palsy (RNP), a patient with a PINP is able to extend their wrist but in radial deviation, because of the preserved innervation of the extensor carpi radialis longus (ECRL). Tendon transfers to restore finger and thumb extension in PINP have been extrapolated from tendon transfers to restore these functions in RNP, specifically using flexor carpi radialis, not flexor carpi ulnaris, so as not to further exacerbate the distinctive radial deviation deformity of the wrist. However, the standard pronator teres to extensor carpi radialis brevis transfer for a RNP fails to address or correct the radial deviation deformity in PINP. We present a simple tendon transfer specifically to address this radial deviation deformity in a PINP, by performing a side-to-side tenorrhaphy of the ECRL tendon to the extensor carpi radialis brevis tendon, followed by transection of the ECRL insertion onto the base of the index finger metacarpal distal to the tenorrhaphy. This technique converts a functioning ECRL from a radially deforming force, transferring its vector of pull onto the base of the middle finger metacarpal and so producing centralization of wrist extension in axial alignment with the forearm.

Study of Short-Term Outcome of Surgically Managed Displaced Pediatric Radial Neck Fractures: A Case Series.

INTRODUCTION: Pediatric radial neck fractures are relatively rare elbow injuries commonly seen in children between eight to 12 years of age. Judet type III and Judet type IV radial neck fractures require surgical intervention for optimal functional outcomes. The present study evaluates the functional results of Judet type III and IV radial neck fractures operated at a single center. MATERIALS AND METHODS: This is a retrospective study conducted by using medical records of nine patients who had displaced radial neck fractures (Judet type III and type IV) treated at our institute which is a tertiary trauma care center between January 2012 and December 2021. Patients were assessed for functional outcome by Mayo elbow performance score (MEPS), the Tibone and Stoltz functional criteria, and for complications with the average follow-up of four years (range: six months to seven years).  Results: The mean age of the patients was 9.14 ± 2.2 years (range: four to 11 years). Seven (77.8%) patients were males and two (22.2%) patients were females. The right side was the most commonly injured side (right at 67%, left at 33%). Five (55%) cases were of Judet type III and four (45%) cases were of Judet type IV. Three cases treated with closed reduction and intramedullary nailing by the Metaizeau technique had excellent functional results. Among two patients treated with percutaneous pin leverage and intramedullary nailing by the Metaizeau technique, one patient had an excellent outcome, and the other had a good outcome. Among four cases treated with open reduction and K-wire fixation, two patients had good outcomes, one patient had a fair outcome, and one patient had a poor outcome. CONCLUSION: The majority of moderately to severely displaced pediatric radial neck fractures which need intervention can be managed by the closed reduction technique of Metaizeau with or without pin leverage with excellent to good functional outcomes at short-term follow-up. Some cases need open reduction which also has good to fair outcomes. Initial trauma and associated injuries seem to play a role in the outcome rather than the treatment method per se. However, a larger sample size and longer follow-up are needed for comparisons and for arriving at better and definitive conclusions.

Brachioradialis to Extensor Carpi Ulnaris Transfer - An Additional Transfer to Prevent Radial Deviation Deformity of the Wrist following Tendon Transfers for Posterior Interosseous Nerve Palsy.

The usual recommendation in posterior interosseous nerve (PIN) palsy is to use the flexor carpi radialis instead of the flexor carpi ulnaris (FCU) for restoration of digital extension. The use of FCU takes away the only remaining ulnar deviator of the wrist. Although preserving the FCU prevents severe radial deviation deformity, we found that some patients still develop a radial deviation deformity, especially during wrist extension. We have used a brachioradialis (BR) to extensor carpi ulnaris (ECU) transfer to prevent the development of a radial deviation deformity and find that it restores the normal radio-ulnar balance of the wrist by providing a dynamic ulnar stabiliser. It is a simple addition to the standard two tendon transfers for PIN palsy with minimal donor morbidity. We have used this triple transfer for PIN palsy in seven patients with satisfactory results and no complications. Level of Evidence: Level V (Therapeutic).

Medial three-finger drop in high-energy forearm trauma: An unrecognized peripheral nerve injury. A report of two cases.

CASE: Absent active extension at metacarpophalangeal (MCP) joints of medial three fingers with intact extension of index finger and thumb following high energy forearm trauma due to recurrent branch of posterior interosseous nerve (RBPIN) injury has not been reported yet. The aim is to highlight an unrecognized sequel of a commonly encountered forearm trauma in two patients who sustained fractures around the elbow and forearm. CONCLUSION: In the acute traumatic setting, medial three-finger drop due to RBPIN injury can be missed or misdiagnosed. This has medico-legal and prognostic implications.

The Window Test: A Simple Bedside Method to Detect Radial Deviation of the Wrist Commonly Seen in Posterior Interosseous Nerve Palsy.

BACKGROUND: Posterior interosseous nerve palsy (PINP) is a disorder caused by damage to the posterior interosseous nerve, resulting in weak extension of the wrist and fingers as well as radial deviation of the wrist. METHODS: This study analyzed a new type of evaluation for PINP in hopes of increasing ease of diagnosis and earlier detection of the disorder. The window test is performed by the examiner laying hands on the ulnar aspect of the patient's pronated forearm while the patient tries to extend the wrist. A positive test is obtained when a gap (window) appears between the examiner's forearm and the patient's hand. Laypeople, medical students, residents, and practicing providers were assessed prospectively on their ability to correctly diagnose PINP by observing one hand, by observing both hands and by using the window test. RESULTS: The window test was consistently found to be the most effective method of evaluation, as it increased the accuracy of diagnosis in all groups surveyed. Additionally, case studies were performed using the window test on patients, further demonstrating the efficacy of the test by confirming wrist radial deviation. CONCLUSIONS: The window test introduces a reference frame making it easier to assess wrist radial deviation and offering a simple evaluation that can be administered by virtually anyone. These findings indicate that the implementation of the window test will increase the accuracy and effectiveness of PINP diagnosis, thus allowing early diagnosis and better management.

A rare case of posterior interosseous nerve palsy due to ganglion cyst arising from supinator muscle.

Here we present a rare case of ganglion cyst of the elbow joint arising from supinator muscle causing posterior interosseous nerve (PIN) palsy in a 40-year-old female who presented with weakness in finger extension and carrying out routine activities with right hand since 2 weeks. Patient had pain over the right forearm radiating to the right hand since 3 months. She also noted a swelling in the right forearm, which was gradually increasing in size since last 1 month. Atraumatic PIN compression is uncommon and is usually caused by compression of PIN in the arcade of Frohse, by radial recurrent artery, and fibrous band around the radiocapitellar joint. Reports of PIN palsy caused by ganglionic cyst in the elbow joint are rare and case reports regarding the same are sparingly reported. Here we report a case of PIN palsy secondary to ganglion cyst arising from supinator muscle, which recovered completely after excision of the ganglion cyst.

Pathological Findings of Hourglass-Like Constriction in Spontaneous Posterior Interosseous Nerve Palsy.

We report the pathological findings of hourglass-like fascicular constriction (HLFC) under optical and electron microscopy. A 24-year-old man with spontaneous posterior interosseous nerve palsy was treated by interfascicular neurolysis at 29 weeks after onset. One fascicle in the radial nerve presented severe HLFC with torsion at 5 cm proximal to the elbow. Functional recovery was achieved by resection of the enlarged fascicle including HLFC and sural nerve grafting. Proximal to the HLFC, the endoneurium was filled with clusters of regenerating nerve fibers. At the level of the HLFC, a complete loss of myelinated nerve fibers and vascular occlusion of endo- and perineurial vessels were found. Few regenerating nerve fibers were observed. Distal to the HLFC, severe endoneurial edema, a complete loss of myelinated and unmyelinated nerve fibers, and bands of Büngner were noted. These electron microscopic findings demonstrated a detailed pathology of the nerve around the HLFC.

Posterior interosseous nerve palsy caused by synovial osteochondromatosis of the elbow analyzed by three-dimensional reconstruction: a case report.

BACKGROUND: Synovial osteochondromatosis, a benign tumor consisting of cartilage and bone, generally presents as multiple osteochondral or chondral nodules. Peripheral nerve palsy caused by synovial osteochondromatosis is rare. Three-dimensional reconstruction based on magnetic resonance imaging shows the specific shape and location of the tumor and its relation to the nerve. CASE PRESENTATION: We describe a case of posterior interosseous nerve palsy caused by synovial osteochondromatosis of the elbow in a 66-year-old Japanese man. A three-dimensional reconstructed image based on magnetic resonance imaging was used to determine the location and shape of the giant tumor, which was composed of bone and cartilage. After surgical resection of the giant tumor and neurolysis of the posterior interosseous nerve, he fully recovered from nerve palsy 9 months postoperatively. There was no recurrence of the lesion 1 year postoperatively. CONCLUSION: Synovial osteochondromatosis that causes posterior interosseous nerve palsy has a characteristic morphology and location, that is, a giant tumor located anterior to the humeroradial joint, as revealed by three-dimensional magnetic resonance image reconstruction.

Hourglass-Like Constriction of the Brachial Plexus in the Posterior Cord: A Case Report.

BACKGROUND AND IMPORTANCE: Hourglass-like constrictions are fascicular conditions confirmed definitively by interfascicular neurolysis. Certain peripheral nerves have vulnerable areas such as around the elbow in the posterior interosseous nerve. We report the first hourglass-like constriction in the brachial plexus supplying the radial innervated forearm musculature. Preoperative magnetic resonance imaging (MRI) findings of the brachial plexus were consistent with neuralgic amyotrophy (NA). CLINICAL PRESENTATION: A 9-yr-old boy experienced worsening left arm pain and difficulty in elevating the shoulder. Sequentially, severe palsy emerged when extending the wrist, thumb, and fingers. Based on the clinical picture, we diagnosed him with NA. The oblique coronal T2-weighted short-tau inversion recovery images showed mildly diffuse enlargement and hyperintensity of the brachial plexus. He showed few signs of improvement and interfascicular neurolysis was performed 11 mo after the onset. One of the fascicles in the posterior cord had developed an hourglass-like constriction. Electrical stimulation confirmed that the fascicle supplied forearm muscles. His wrist and finger extension had almost recovered at the 12-mo postoperative visit. CONCLUSION: Hourglass-like constrictions can occur in the brachial plexus. Although surgical approaches for the constrictions are still controversial, several reports demonstrated their effectiveness. Meanwhile, concerning NA treatment, evidence on the surgical intervention is lacking. Brachial plexus MRI might help in discerning the lesion and planning treatment options including surgical interventions. Hourglass-like constrictions are a possible etiology for certain NA patients with residual symptoms or paresis.

Posterior Interosseous Nerve Palsy Caused by a Ganglion of the Arcade of Frohse.

A 51-year-old male who is right-handed visited the outpatient for right fingers-drop. The patient's fingers, including thumb, were not extended on metacarpophalangeal joint. The active motion of the right wrist was available. The electromyography and nerve conduction velocity study were consistent with the posterior interosseous neuropathy. Further evaluation was done with the magnetic resonance imaging for finding the space-occupying lesion or any possible soft tissue lesion around the radial nerve pathway. On magnetic resonance imaging, the ganglion cyst, which was about 1.8 cm in diameter, was observed on the proximal part of the superficial layer of the supinator muscle (Arcade of Frohse). The surgical excision was done on the base of ganglion cyst at the base of stalk of cyst which looked to be connected with proximal radioulnar joint capsule. The palsy had completely resolved when the patient was observed on the outpatient department a month after the operation.

Posterior Interosseous Nerve Palsy Caused by a Ganglion of the Arcade of Frohse

A 51-year-old male who is right-handed visited the outpatient for right fingers-drop. The patient's fingers, including thumb, were not extended on metacarpophalangeal joint. The active motion of the right wrist was available. The electromyography and nerve conduction velocity study were consistent with the posterior interosseous neuropathy. Further evaluation was done with the magnetic resonance imaging for finding the space-occupying lesion or any possible soft tissue lesion around the radial nerve pathway. On magnetic resonance imaging, the ganglion cyst, which was about 1.8 cm in diameter, was observed on the proximal part of the superficial layer of the supinator muscle (Arcade of Frohse). The surgical excision was done on the base of ganglion cyst at the base of stalk of cyst which looked to be connected with proximal radioulnar joint capsule. The palsy had completely resolved when the patient was observed on the outpatient department a month after the operation.

Anterior Dislocation of Elbow with Neurovascular Injury: A Rare Case Report.

INTRODUCTION: Anterior elbow dislocation is an infrequent lesion, produced by direct trauma to the proximal ulna after a fall on the elbow in flexion and injury to the neurovascular bundle is not infrequent. Authors report a case of acute anterior dislocation of the elbow joint with neurovascular injury. CASE REPORT: A 30-year-old male admitted with a history of accidental fall followed by pain, swelling over his left elbow. Clinical, radiological, Doppler investigations revealed anterior dislocation of the elbow with brachial artery injury with posterior interosseous nerve palsy without any bony injury. Immediate closed reduction, primary vascular repair with fasciotomy was done following which elbow function improved. CONCLUSION: Anterior dislocations of elbow joint are among the rarest of injuries. Because the dislocation is anterior, injury to nerve and vessel can occur frequently. Therefore, a careful assessment for neurovascular injury mandatory. Early proper reduction and management of neurovascular injury if any is necessary for good elbow function.

Nontraumatic "isolated" posterior interosseous nerve palsy: Reinterpretation of electrodiagnostic studies and MRIs.

INTRODUCTION: Different hypotheses have been proposed for the pathophysiology of posterior interosseous nerve (PIN) palsy, namely compression, nerve inflammation, and fascicular constriction. We hypothesized that critical reinterpretation of electrodiagnostic (EDX) studies and MRIs of patients with a diagnosis of PIN palsy could provide insight into the pathophysiology and treatment. MATERIALS AND METHODS: We retrospectively reviewed patients with a diagnosis of nontraumatic PIN palsy and an upper extremity EDX and MRI. The original EDX studies and MRIs were reinterpreted by a neuromuscular neurologist and musculoskeletal radiologist, respectively, both blinded to our hypothesis. RESULTS: Fifteen patients met the inclusion criteria, i.e., having an "isolated" PIN palsy. Four patients (27%) had a defined mass compressing the PIN. The remaining 11 patients (73%) presented with at least one finding incompatible with the compression hypothesis: physical examination revealed that weakness in muscles was not innervated by the PIN in 4 patients (36%); EDX abnormalities not related to the PIN were found in 4 patients (36%); and reinterpretation of the MRIs showed muscle atrophy or nerve enlargement beyond the territory of the PIN in 9 patients (82%), without any evidence of compression of the PIN in the proximal forearm. CONCLUSION: The eleven patients in our series with presumed isolated and idiopathic PIN palsy had evidence of a more diffuse nerve-muscle involvement pattern, without any radiologic signs of nerve compression of the PIN itself. These data would favor an inflammatory pathophysiology when a structural lesion compressing the nerve is ruled out with imaging.

Posterior interosseous nerve palsy associated with neglected pediatric Monteggia fracture-dislocation: A case report.

INTRODUCTION: The main goal of the treatment is the anatomical reduction of the ulna fracture and the radial head dislocation in acute and chronic Monteggia cases. Acute pediatric Monteggia lesions are generally treated non-surgically; however, the treatment of chronic Monteggia is challenging. The aim of this article is to share our experiences about treatment of neglected Monteggia lesion. PRESENTATION OF CASE: A 6-year-old girl who underwent a surgery in our clinic for a missed Bado type-III Monteggia fracture-dislocation of the right elbow with concomitant posterior interosseous nerve (PIN) palsy, which resolved spontaneously after the operation. The operation consisted of open reduction of the radial head, transverse ulnar osteotomy and fixation with an intramedullary Kirchner wire, and annular ligament repair without exploring PIN. The patient was seen in routine follow-up periods until the postoperative first year using plain radiographies. At 16th week follow-up, all functions of the PIN were returned. At first-year follow-up, full range of elbow motion was observed; plain radiographies showed radiocapitellar joint congruency, and Mayo Elbow Performance Index was one hundred. DISCUSSION: Treatment planning for chronic, neglected or missed Monteggia fractures is challenging. There is no consensus about the definitive treatment in the literature. CONCLUSION: We recommend anatomic and stable restoration of radiocapitellar joint by correcting ulna deformity. Radiocapitellar fixation and PIN exploration may not be necessary in all neglected Monteggia lesions.

Interfascicular Neurolysis for Incomplete Spontaneous Posterior Interosseous Nerve Palsy with a Surgical Delay of 17 Years: Is It Still Effective?

A 55-year-old woman with incomplete spontaneous posterior interosseous nerve (PIN) palsy underwent interfascicular neurolysis and tendon transfer, 17 years after its onset. After one year, her nerve function partially recovered electrophysiologically. This case suggests that incomplete spontaneous PIN palsy may recover by interfascicular neurolysis, even with a long preoperative delay.