We reviewed the medical records and radiographs of six patients (seven shoulders) with neuropathic arthropathy of the shoulder who were referred to the senior one of us (C. A. R., Jr.) during a twenty-eight-year period (from 1969 through 1997). All six patients were men, and the average age was forty-seven years (range, twenty-nine to sixty-six years). The dominant extremity was involved in three patients, and one patient had bilateral involvement.
The presence or absence of pain, swelling, loss of function, stiffness, grinding, popping, weakness, paresthesias, and dysesthesias was noted. Physical examination focused on atrophy, the active and passive ranges of motion, muscle strength, sensory function, and deep tendon reflexes. Overall function of the shoulder was assessed with the shoulder-rating scale of the University of California at Los Angeles5.
The radiographs of all six patients were reviewed to assess, when possible, the rate of osseous destruction of the humeral head and the proximal aspect of the humerus. The time from presentation to diagnosis was also recorded as were any previous operative procedures involving the affected shoulder.
CASE 1. A sixty-six-year-old man was seen because of mild pain in the right arm and shoulder after a fall from a chair in May 1981. The medical history was positive for cervical disc disease, which had necessitated an anterior arthrodesis of the fifth, sixth, and seventh cervical vertebrae in 1972. The initial radiographs of the right shoulder revealed mild degenerative changes that involved only the acromioclavicular joint (Fig. 1-A). Radiographs that were made three weeks later showed resorption of nearly 50 per cent of the humeral head (Fig. 1-B). Physical examination revealed generalized swelling about the shoulder and a slight decrease in active forward elevation, with pain at the extremes of motion. An incisional biopsy was performed, and gram stains and routine cultures were negative. The biopsy revealed necrotic bone, hypervascularity, and degenerative articular cartilage. Routine laboratory tests, including serum chemistry studies and a complete blood-cell count with differential, revealed normal findings. The patient was managed with a program of physical therapy as well as with anti-inflammatory medication and analgesics. Three months after the initial presentation, radiographs revealed complete resorption of the humeral head, the proximal humeral metaphysis, and the glenoid (Fig. 1-C).
When the patient was referred to our institution, nearly five years after the initial presentation, the main symptom was loss of function of the right shoulder with slight pain. Active forward elevation was to 40 degrees on the right and to 160 degrees on the left, active external rotation was to 30 degrees on the right and to 50 degrees on the left, and active internal rotation was to the level of the sacrum on the right and to the eighth thoracic level on the left. The biceps reflex was decreased. A diagnosis of neuropathic arthropathy was considered, and magnetic resonance images of the spine revealed a large syrinx of the caudad portion of the cervical cord.
CASE 2. A twenty-nine-year-old man who had no history of medical problems was seen because of pain in the left shoulder and the neck as well as swelling of the shoulder after lifting heavy scaffolding at work. Radiographs that were made eleven days after the injury showed mild resorption of the humeral head as well as a pathological fracture of the proximal aspect of the humerus. An incisional biopsy revealed no evidence of malignant tumor, and gram stains and routine cultures of intraoperative specimens were negative. Repeat radiographs, made four weeks after the injury, revealed complete resorption of the humeral head with osseous debris about the glenohumeral joint.
During the next eighteen months, the patient began to have neurological symptoms, including weakness and atrophy of the upper extremities, absence of deep tendon reflexes in the upper extremities, and clonus of the left lower extremity. Magnetic resonance imaging, performed approximately eighteen months after the injury, demonstrated a large syrinx extending from the level of the third cervical vertebra to the level of the third thoracic vertebra. The patient refused neurosurgical intervention to treat the syringomyelia.
On referral to our institution, eighteen months after the injury, the patient reported pain, weakness, and decreased function of the left shoulder. Active forward elevation was to 40 degrees on the left and to 155 degrees on the right, active external rotation was to 25 degrees on the left and to 45 degrees on the right, and active internal rotation was to the fifth lumbar level on the left and to the seventh thoracic level on the right. Passive forward elevation was to 90 degrees on the left, with pain. The strength of the deltoid was grade 4 (of 5), and the strength of the muscles of the rotator cuff was grade 3. There was decreased sensation to light touch involving the entire left upper extremity. The biceps, triceps, and brachioradialis reflexes were absent. Radiographs revealed complete resorption of the humeral head.
The patient was advised to continue passive stretching exercises to maintain a maximum range of motion of the left shoulder.
CASE 3. A fifty-five-year-old man was seen because of a painless anterior dislocation of the right shoulder after being struck by an opening door. The dislocation was reduced in the local emergency room. Twenty-eight years previously, the patient had sustained a fracture of the cervical spine, which was treated with traction and a body cast. This injury had left the patient with mild weakness of the upper extremities; the weakness gradually worsened, and, by two years before the injury of the shoulder, it had progressed to the lower extremities. At the time of the dislocation, the patient was using a motorized wheelchair for transportation.
Radiographs that were made eight days after the index injury revealed resorption of 30 per cent of the humeral head. An incisional biopsy, performed to rule out malignant disease, revealed necrotic bone, abundant osteoclastic resorption, and degenerative articular cartilage. Intraoperative gram stains and routine cultures were negative. Serum chemistry studies and a complete blood-cell count with differential revealed normal findings. The patient began a rehabilitation program of exercises. Complete resorption of the humeral head was noted on radiographs that were made two months after the injury.
On referral to our institution, nine months after the injury, the main symptom was loss of function of the right shoulder. Active forward elevation was to 50 degrees on the right and to 130 degrees on the left, active external rotation was to 40 degrees bilaterally, and active internal rotation was to the fourth lumbar level on the right and to the ninth thoracic level on the left. The right shoulder was grossly unstable anteriorly, inferiorly, and posteriorly; there was no pain or apprehension. Motor strength of the deltoid and the muscles of the rotator cuff was grade 3 on the right compared with grade 4 on the left. The strength of the biceps and the triceps was grade 4 bilaterally. Magnetic resonance imaging demonstrated a cervical syrinx, which was treated with a shunting procedure. This procedure did not result in improved function, although the shoulder remained pain-free at the latest follow-up examination, approximately eleven years after the initial injury.
CASE 4. A forty-seven-year-old man was initially seen because of persistent swelling and mild pain around the left shoulder after falling off a bicycle. Eight weeks after the injury, active forward elevation was to 120 degrees on the left and to 155 degrees on the right, active external rotation was to 40 degrees on the left and to 50 degrees on the right, and internal rotation was to the level of the sacrum on the left and to the twelfth thoracic level on the right. The findings of the neurological examination were normal. Mild swelling was noted about the shoulder. Radiographs revealed resorption of the left humeral head and a normal-appearing right shoulder.
Four months after the initial injury, the patient was referred to a neurologist because of numbness involving both hands. A diagnosis of multiple sclerosis was made, and the patient continued to have symptoms of neurological deterioration, including weakness of all four extremities and clonus of the lower extremities, over the course of the next fifteen years. Magnetic resonance imaging of the spine, performed fourteen years after the initial presentation, revealed a cervicothoracic syrinx.
After neurosurgical decompression and shunting, the patient was referred to our institution for evaluation and treatment of the left shoulder. Physical examination revealed that the ranges of active and passive motion were remarkably similar to those that had been recorded at the initial examination. However, marked weakness of both upper extremities had developed, and no reconstructive operation was offered. At the latest follow-up examination, approximately twenty years after the inital presentation, the function of the shoulder was still poor secondary to muscle weakness.
CASE 5. A fifty-three-year-old man who had a history of chronic alcoholism initially was seen one year after a spontaneous onset of painless swelling and diminished function of the right shoulder. Active forward elevation was to 40 degrees on the right and to 150 degrees on the left, active external rotation was to 20 degrees on the right and to 45 degrees on the left, and active internal rotation was to the fifth lumbar level on the right and to the eleventh thoracic level on the left. Passive forward elevation was to 100 degrees and passive external rotation was to 30 degrees on the right. The strength of the deltoid, rotator cuff, and biceps was grade 3, and the strength of the triceps was grade 4. Sensory examination revealed decreased sensation to light touch and pinprick throughout the entire upper extremity. The biceps, triceps, and brachioradialis reflexes were present, but only at a trace level. Neurological examination of the left upper extremity revealed normal findings. Radiographs of the right shoulder revealed complete resorption of the humeral head and the proximal humeral metaphysis. Resorption of the glenoid was also noted, and osseous debris was evident in the periarticular soft tissues. The diagnosis of neuropathic arthropathy was made on the basis of the presenting symptoms as well as the clinical and radiographic findings. A subsequent magnetic resonance image of the spine, made two years after the initial presentation, was unremarkable. The patient began a rehabilitation program that emphasized painless passive stretching and strengthening exercises for the deltoid, the rotator cuff, and the scapular stabilizers.
CASE 6. A thirty-four-year-old man was seen because of a painless anterior dislocation of the right shoulder that had occurred when he attempted to catch an object that had fallen from a shelf. Radiographs that were made at the time of the initial examination were unremarkable. Nine months after the initial injury, the patient was managed with a Bristow procedure because of a number of recurrent episodes of anterior dislocation of the right shoulder. He continued to have instability and intermittent swelling. Arthroscopy revealed degeneration of the articular cartilage of the humeral head and the glenoid.
Five years after the patient was first seen, he noticed painless swelling and asymmetry of the left shoulder and was unable to use the left upper limb to shave, bathe, or dress. Radiographs revealed a fracture of the left scapular body, which was treated with open reduction and internal fixation with use of a four-hole AO 3.5-millimeter reconstruction plate (Synthes, Paoli, Pennsylvania). Three weeks later, a revision was performed with use of two reconstruction plates because the original hardware had failed. Radiographs of the right shoulder that were made during the second hospital stay revealed complete resorption of the humeral head and the glenoid. Radiographs of the left shoulder also demonstrated resorption of the humeral head.
When the patient was seen by us, six years after the onset of the initial symptoms, the main symptom was loss of function in both shoulders. The patient also had occasional mild aching pain in the right shoulder. Physical examination revealed moderate swelling about the right shoulder as well as gross anterior, posterior, and inferior instability. Active forward elevation was to 120 degrees on the right and to 145 degrees on the left, active external rotation was to 40 degrees on the right and to 45 degrees on the left, and active internal rotation was to the third lumbar level on the right and to the sacrum on the left. The neurological examination revealed dissociative sensory loss involving the fifth, sixth, and seventh cervical dermatomes bilaterally.
The diagnosis of neuropathic arthropathy was made, and magnetic resonance imaging revealed a cervical syrinx. The patient was referred to the neurosurgical service, but decompression of the syrinx was not performed.
The onset of symptoms related to the shoulder was acute in five of the six patients. These five patients were able to recall a traumatic injury, usually minor, involving a previously normal shoulder. Three patients (three shoulders) had pain in the shoulder, and two of these three also had pain in the arm or the neck. The pain was relatively mild in all shoulders; only one patient (Case 2) had a pain score of 6 of 10 points (pain during heavy or particular activities only) according to the rating scale of the University of California at Los Angeles5. The other four shoulders were painless (Table I).
All six patients had neurological symptoms (Table I). Five patients had motor weakness. All six patients had sensory changes: five patients had decreased sensation to light touch and one had dissociative sensory loss. Asymmetrical reflexes involving the upper extremities were noted in five patients, with two patients having absent reflexes in the involved limb. Two patients had symptoms involving the lower extremities, including weakness and clonus. Both of these patients had documented syringomyelia.
Radiographs revealed resorption of the humeral head in all seven shoulders. The patient (Case 2) who had a pathological fracture of the proximal aspect of the humerus had radiographic evidence of proliferation of bone at the fracture site. The average time between the onset of symptoms and radiographic evidence of resorption of the humeral head was thirteen days (eight, eleven, and twenty-one days) in the three patients for whom serial radiographs were available. With the available radiographs, resorption of the humeral head was noted in the three remaining patients, at eight weeks (Case 4), one year (Case 5), and five years and three weeks after the injury (Case 6). Resorption of the glenoid or osseous debris about the soft tissues, or both, was noted in four of the six patients.
Five patients (six shoulders) had evidence of a syrinx on magnetic resonance images. The average time between the onset of symptoms and the diagnosis of syringomyelia was sixty-seven months (range, ten to 180 months).
Four patients had had at least one operative procedure involving the shoulder before the diagnosis of neuropathic arthropathy. Three patients had had an incisional biopsy and one had had a Bristow procedure, arthroscopy of the shoulder, and two procedures for open reduction and internal fixation of the scapula.
Neuropathic arthropathy involving the shoulder joint is a relatively rare disorder. In a series of thirty-nine neuropathic joints, Floyd et al. recorded only two cases (5 per cent) involving the shoulder. Johnson studied 118 cases of neuropathic joint disease and found that ten were associated with syringomyelia, with involvement predominantly of the joints of the upper extremity. Meyer et al. stated that arthropathies develop in 25 per cent of cases of syringomyelia and that 80 per cent of syringomyelic arthropathies involve the upper limb. (Exact numbers were not reported in that study.) Neuropathic arthropathy of the shoulder often presents in a striking fashion, producing extensive and rapid destruction of the proximal aspect of the humerus and the glenoid. The differential diagnosis often includes primary and metastatic malignant tumor, tuberculous and microbial infection, and Gorham disease (vanishing bone disease)2,9.
Delay in the diagnosis of this condition is common, and the average time to diagnosis in the present study was sixty-seven months. This entity may coexist with infection of the joint7,23. Our review of the literature identified nineteen studies with a total of twenty-eight patients (thirty-one shoulders) who had a documented history of neuropathic arthropathy of the shoulder (Table II)1,4,8,10,12-14,16-27. The most frequent presenting symptom was swelling, which was present in twenty-nine of the thirty-one shoulders1,4,8,10,12-14,16,18-27. Twenty-five of the thirty-one shoulders had pain at presentation1,4,8,10,12-14,16-18,20-22,24,26,27. Skall-Jensen noted pain in three of six cases; this rate is similar to the pattern observed in the present study, in which three of the seven shoulders were painful. After swelling and pain, stiffness or loss of motion is the most frequent presenting symptom in these patients; nineteen of the thirty-one shoulders reported on in the literature1,4,10,12-14,16,17,20-25,27 and all seven of the shoulders in the present study had diminished motion at the time of presentation.
Syringomyelia may present as instability of the shoulder21, and instability or frank dislocation is not unusual in the neuropathic shoulder4,8,12,13,18. Two patients (Cases 3 and 6) in the present study were initially seen for painless anterior dislocation. This finding differs somewhat from the pattern observed by Richards and Delaney, who reported on three patients who had either painful instability or a painful fixed dislocation of the shoulder at the time of presentation.
The symptomatic shoulder is often treated operatively before the diagnosis of underlying neuropathic arthropathy is made12,13,16,17,19,21,24,26. Incisional biopsy is frequently performed in an effort to exclude neoplasm or infection as the cause of the destruction of the joint as seen on plain radiographs12,16,19,24,26. In the present study, four patients had had at least one operative procedure before the neuropathic arthropathy was diagnosed; specifically, three patients had an incisional biopsy and one patient had a Bristow procedure, arthroscopy of the shoulder, and two procedures for open reduction and internal fixation of a scapular fracture.
We are aware of the cases of two patients with known neuropathic arthropathy of the shoulder who were managed successfully with either arthrodesis12 or total shoulder arthroplasty17. However, whereas the patient who had had the arthrodesis was followed for fourteen years, the patient who had had the arthroplasty was followed for only two years. Mau and Nebinger reported failure when arthrodesis was performed to treat neuropathic arthropathy of the shoulder and concluded that this condition is a contraindication to arthrodesis. Those authors also stated that synovectomy is not helpful and that a neuropathic shoulder should be treated non-operatively, with an emphasis on the maintenance of function. We concur with these conclusions and agree that the maintenance of function, rather than immobilization, is the keystone of treatment.
Magnetic resonance imaging of the spine demonstrated the presence of a syrinx in five of the six patients in the present study. The remaining patient had normal findings at the time of magnetic resonance imaging, one year after the onset of symptoms in the shoulder. This patient had a history of chronic alcohol abuse and did not recall any pain or antecedent traumatic injury. It is likely that the neuropathic disease was secondary to an alcoholic neuropathy, much as Charcot changes in the lower extremity can be secondary to diabetic neuropathy.
Our series includes two patients who were seen for neuropathic arthropathy of the shoulder and were subsequently found to have syringomyelia tarda. One patient (Case 3) had sustained a cervical fracture nearly thirty years before the onset of the symptoms in the shoulder; the fracture had been treated with traction and a body cast. This patient also had progressive neurological deterioration involving both the upper and the lower extremities, which predated the neuropathic symptoms in the shoulder by two years. The other patient (Case 1) had had an anterior cervical arthrodesis fourteen years previously. To our knowledge, this is the first reported case of syringomyelia tarda presenting with neuropathic disease of the shoulder after elective cervical arthrodesis.