Recurrently Infected Rheumatoid Nodule Causing Posterior Interosseous Nerve Palsy: A Report of a Rare Case

Radial head fractures are common injuries which can be managed conservatively in the absence of instability or mechanical block at the elbow. We report a case of radial head and neck fracture which uniquely incorporates two rare complications: posterior interosseous nerve (PIN) palsy, and locking of the proximal radio-ulnar joint. The causative mechanisms are described with review of the relevant literature.

We present 3 cases with peripheral neuropathies of the median, posterior interosseous, and ulnar nerves associated with rheumatoid synovial cysts of the elbow joint. Magnetic resonance imaging and electrophysiological examination led to the final diagnosis of the relation to synovial cysts of the elbow joint. All patients underwent surgical decompression of these nerves and synovectomy of the elbow joint. Functional recovery was excellent in the 2 patients with median and posterior interosseous nerve palsy but incomplete in the patient with ulnar nerve palsy. Such neuropathies require consideration in the differential diagnosis of wrist and hand disability in patients with rheumatoid arthritis. This awareness should enhance early diagnosis and treatment by surgical decompression.

Isolated posterior interosseous nerve palsy is an uncommon condition and its management is controversial. Existing literature is sparse and a treatment algorithm based on existing best evidence is absent. A comprehensive review was undertaken to elucidate the causes of spontaneous posterior interosseous nerve palsy and suggest a management strategy based on the current evidence. Posterior interosseous nerve palsy can be broadly categorized as compressive and non-compressive, and the existing evidence supports surgical intervention for compressive palsy. For posterior interosseous nerve pathology with no compressive lesion on imaging, conservative management should be tried first. Surgery is therefore reserved for compressive lesions and for failure of conservative management. The commonly performed operative procedures include decompression and neurolysis, neurorrhaphy and nerve grafting, and tendon transfers with or without nerve grafting performed as a salvage procedure. The prognosis is poorer in patients aged > 50 years, those with a delay to surgery, and those who have had long-standing compression with severe fascicular thinning.

Posterior interosseous nerve palsy (PINP) is a rare complication of rheumatoid arthritis of the elbow. A 58-year-old woman with rheumatoid arthritis, who complained of an inability to extend her left fingers, was referred to our hospital. After a series of studies, extensor tendon ruptures were excluded, and PINP was diagnosed. By means of the Henry anterolateral approach, the radial nerve was exposed, which was compressed by swollen synovial membrane at the Frohse arcade. Elbow synovectomy was performed, and the arcade was opened to release the nerve. The PINP has been recovered completely within 2 weeks after surgery. Various examinations other than magnetic resonance imaging have been reported for the adjunctive diagnosis of PINP, but MR imaging was most useful as an adjunctive examination in this case.

Posterior interosseous nerve palsy caused by ganglions of the proximal radioulnar joint

Introduction:Monteggia fracture-dislocations are rare in children can often go undiagnosed, especially when initial treatment is provided by non-specialists. Missed injuries can result in chronic instability, pain, and limited function of the elbow joint.Case Report:We report the case of an 8-year-old girl who sustained an injury to her left elbow after falling while escaping a monkey attack. She initially received only bandaging from a local practitioner and presented to us 1 month later with ongoing pain and restricted elbow movement with posterior interosseous nerve (PIN) palsy. Radiographs revealed a neglected Monteggia fracture-dislocation. She was treated surgically with ulnar osteotomy and fixation with a 3.5 mm dynamic compression plate without reduction of the Radial head. The radial head was found to be reduced after ulnar osteotomy and plate fixation. PIN was not explored. Over a 15-month follow-up, the fracture united well, the radial head remained anatomically positioned, and the patient regained a full range of motion without pain with complete recovery of PIN palsy.Conclusion:This case highlights the potential for Monteggia lesions to be overlooked when not properly assessed at the time of injury. It underscores the importance of early diagnosis and appropriate orthopedic intervention to prevent long-term complications. Even in delayed cases, satisfactory outcomes can be achieved with timely surgical management.

Introduction and importancePosterior interosseous nerve syndrome secondary to compression by a synovial cyst at the elbow is a rare and often unrecognized pathology. Early management relies on complete neurolysis to achieve satisfactory functional recovery. Increasing awareness among the orthopedics will help in the early diagnosis of the disease and in the initiation of early and proper treatment. Case presentationIn this article, we report the case of a 32-year-old patient with posterior interosseous nerve syndrome secondary to compression by a synovial cyst of the elbow. Surgical management combined with post-operative rehabilitation resulted in indolence with good functional recovery. Clinical discussionPosterior interosseous nerve syndrome secondary to compression by a synovial cyst at the elbow is a rare entity. Anatomically, the deep branch of the radial nerve or posterior interosseous nerve passes through the Fröhse's arch or arch of the supinator muscle at the elbow, then travels between the two heads of this muscle. Several anatomical structures may compress the NIOP. Clinically, it presents as paralysis or paresis of the extensor muscles of the fingers and the abductor muscle of the thumb. Limitation of the ulnar extensor carpi may be responsible for radial deviation of the carpus in some cases. MRI is the radiological examination of choice. Electromyography plays a contributory role in diagnosis prior to surgical exploration. Surgical excision is the treatment of choice. It may be combined with radial neurolysis for better recovery. Progression after surgical treatment is generally favourable. ConclusionIgnorance of posterior interosseous nerve palsy syndrome frequently leads to misdiagnosis. Early management relies on complete neurolysis to achieve satisfactory functional recovery.

Intramedullary, unicortical repair of distal biceps tendon rupture

Paralysis of posterior interosseous nerve caused by parosteal lipoma

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.

A 47-year-old healthy male was treated for his tennis elbow with a steroid injection elsewhere. In the affected forearm, he was surgical treated for a forearm fracture, thirty years previously. After the injection, he developed posterior interosseous nerve palsy. He was treated with neurolysis of the nerve from the radial tunnel and distal to the supinator, where it was found to be adherent to the healed fracture site. Most of the motor nerve function returned within two years. We believe this to be an example of a “double crush” phenomenon of the radial nerve. Injection of steroids to treat lateral epicondylitis is extremely common and previous injury or surgery to the extremity should be considered before its administration.

Keegan (1965) reported a patient who presented with "dissociated motor loss," an acute paralysis of the upper extremity with minimal sensory signs and no long tract signs, and documented an anterior root lesion following autopsy. Sobue et al. (1975) reported similar cases using the term "cervical spondylotic amyotrophy (CSA)," but postulated pathology of the anterior horn. Although Keegan's "dissociated motor loss" surely referred to isolated motor paresis with no or minimal sensory signs, contrary to existing criticism, a more general term, CSA, should be preferred. CSA is divided into proximal and distal types. Distal CSA often presents with a drop finger, and thus may be misdiagnosed as posterior interosseous nerve palsy. Documentation of the involvement of ulnar muscles by clinical signs and EMG would lead to the diagnosis of distal CSA. Proximal CSA may be confused with neuralgic amyotrophy (NA), although the sparing of the serratus anterior and the stereotypic involvement of deltoid, infraspinatus, biceps brachii, and brachioradialis suggest CSA. Cervical MRI is not diagnostic in around half of CSA cases, and denervation in paraspinal EMG is a more sensitive test that can exclude NA. Amyotrophic lateral sclerosis is another important differential diagnosis for CSA.

Some tumors or tumorous conditions causing posterior interosseous nerve palsy are well documented, but myositis ossificans causing the palsy of this nerve has not been described. We present a case of posterior interosseous nerve palsy caused by myositis ossificans of the supinator muscle.

Two patients presented with a posterior interosseous nerve palsy with supinator weakness. In each case an intraneural neurofibroma was found proximal to the supinator tunnel with no other stigmata of von Recklinghausen's disease. Both tumours showed a whorl-like histological pattern that has been previously confused with onion-bulb structures in hypertrophic polyneuropathy. Electron-microscopy was useful for the pathological diagnosis. The prognosis and treatment of the lesions are discussed.

Dislocation of the head of the radius associated with fracture of the upper end of the ulna is a common elbow injury in children. The literature on diagnosis, however, is relatively limited. The injury can be misdiagnosed and consequently mismanaged. In the present series of 46 children, the age range was from 2.5 to 12 years. The dislocation of the radial head was lateral in 50% of the cases, posterolateral in 28.2%, anterolateral in 17.4%, and anterior in 4.3%. Thorough clinical and radiological examinations are essential. Simple bending of the upper end of the ulna may help to avoid missing an associated subluxation or dislocation of the radial head. The lower end of the forearm bones should be included in the roentgenographic examination; in 11 out of 46 children (26%) the dislocation of the elbow was associated with a fracture of the lower end of the ipsilateral radius and ulna. Closed reduction is the treatment of choice but if this fails, operative treatment should follow without delay. Posterior interosseous nerve palsy was noted in eight patients (17%), but recovered fully in all of the treated cases.