Neuroarthropathy of the Wrist in Paraplegia: A Case Report

Abstract

Background/Objective:

Neuroarthropathy, also known as Charcot joint, is most commonly seen in the spine and other weight-bearing joints in individuals with spinal cord injury (SCI). It is rarely seen in the joints of the upper extremities because the pathophysiology of the neuroarthropathy is thought to be significant repetitive trauma such as with weight bearing in an insensate joint.

Methods:

Case report of neuroarthropathy in the wrist of a 46-year-old man with a 30-year history of T4 paraplegia caused by ependymoma.

Results:

The patient recently developed a nonpainful swelling in the left wrist, which had decreased sensation since the time of his initial SCI. Radiological evaluation showed marked degenerative changes consistent with neuroarthropathy. A magnetic resonance image of the spine showed spinal cord atrophy at the cervicothoracic junction.

Conclusions:

This case shows an unusual presentation of a neuroarthropathy in a wrist in an individual with functional paraplegia. Because the treatment options for neuroarthropathy in the upper extremity in individuals with SCI are limited, early diagnosis is crucial to implement conservative management before significant destruction of the joint occurs.

INTRODUCTION

Neuroarthropathies, also known as Charcot joints, have been commonly reported in medical and neurological conditions such as diabetic neuropathy, tertiary syphilis, congenital indifference to pain, leprosy, multiple sclerosis, peripheral nerve lesions, pernicious anemia, poliomyelitis, cerebral palsy, syringomyelia, and spinal cord injury (SCI) (1–5). The common factor is recognized as sensory deficit in the affected extremity (2). More recently, as individuals with SCI age and remain active, neuroarthropathies of the spine, shoulders, knees, and elbows have been reported in these individuals (5–9). Neuroarthropathy of the spine in SCI is felt to be caused by the lack of “protective sensation” and uninhibited progression of normal inflammatory responses, ultimately resulting in joint destruction (10). Because of the lack of sensation, there may be repetitive trauma, fractures, and progressive instability, resulting in kyphotic deformities, retrolisthesis, and joint dislocation of the spine (5). Severe gross instability with the formation of a ball-and-socket pseudoarthrosis has been reported (5,7). Usual clinical manifestation of a neuroarthropathy is a pain-free joint or mild discomfort, if any, and the symptom is disproportionately mild in relation to the degree of destructive joint changes seen radiographically (1).

Other unusual neuroarthropathies have been reported in individuals with SCI. Yoshimura and Toyonaga (9) reported a case of an ambulatory individual with SCI who developed a neuroarthropathy in his right knee and ankle. This individual required below-knee amputation after developing an infection in his right ankle. Barber et al (6) reported a case of neuroarthropathy in a shoulder joint in an individual with tetraplegia and secondary syringomyelia. We are not aware of any report of a neuroarthropathy of the wrist in the SCI population. We report a case of neuroarthropathy of the wrist in an individual with paraplegia for almost 30 years.

CASE REPORT

The patient is a 42-year-old white man with T4 ASIA A SCI secondary to ependymoma at the age of 18 years. Although he had been given a diagnosis of T4 ASIA A paraplegia, he noted that he had decreased sensation in the left arm since the time of his initial diagnosis. Several of his physicians speculated as to the reason for impaired sensation in his left arm. One of his neurosurgeons speculated that he may have had partial ischemic injury at the time of his tumor removal, which may have extended to the midcervical level only on his left side. Magnetic resonance imaging (MRI) was not available at that time to further delineate the cause of the patient's left upper extremity numbness.

The patient has been living alone and has been independent with all activities of daily living. As for complications of SCI, the patient had neurogenic bladder, neurogenic bowel, and spasticity. Ten years ago, the patient noted that, although he has always had impaired sensation in the left upper extremity, he began to experience worsening of numbness in his left hand and weakness in his left hand grip. He was diagnosed with left carpal tunnel syndrome by a nerve conduction study, which showed a severe median mononeuropathy with acute denervation, and he underwent a left endoscopic carpal tunnel release. After the carpal tunnel release, his numbness returned to baseline impaired sensation.

Six months before his presentation to our clinic, the patient began to develop a nonpainful swelling in the left wrist. He also reported gradual decrease in the range of motion to a point where he discontinued using a hand cycle exercise machine. He continued to play a flute, but with more difficulty. He did not report any significant changes in his activities of daily living in the previous year. He also denied any specific trauma such as a fall. He was evaluated by multiple physicians, including his primary care physician, a rheumatologist, an orthopedic surgeon, and a hand surgeon.

On physical examination 6 months after the symptoms started, increased soft tissue swelling without erythema around the left wrist was observed (Figure 1). Range of motion of the left wrist was painless and severely restricted in all planes. The left wrist range of motion was as follows: wrist extension, 40 degrees; wrist flexion, 26 degrees; abduction, 6 degrees; adduction, 30 degrees. The left thumb range of motion was also limited to 45 degrees of flexion at the interphalangeal joint. Neurological examination was consistent with T4 ASIA A complete paraplegia, but in addition, the patient had impaired light touch sensation from left C3 to T3 and no pinprick sensation in the left C4 to T3 distribution. He had intact position sense in the left index finger and in the left wrist. Left upper extremity strength was normal. There was a slight warmth at the left wrist compared with the right wrist. Left wrist circumference was 22.5 cm compared with the right wrist circumference of 18 cm. The examination of the right wrist was completely normal.

Figure 1. Left wrist with nonpainful swelling.

The laboratory and radiological examination findings included the following:

• (a) Normal CBC, chemistry, and liver function tests except for elevated alkaline phosphatase = 149 IU/L (reference range, 20–125 IU/L).

• (b) Westergren sedimentation rate of 17 mm/h (reference range, 0–15 mm/h).

• (c) Radiograph of the wrist showed severe osteoarthritis.

• (d) MRI of the cervical spine showed atrophy of the spinal cord at the cervicothoracic juncture involving the upper thoracic cord with no extension of ependymoma. A mild disk bulge was noted at C5–C6 without central spinal or neuroforaminal stenosis (Figure 2).

• (e) MRI of the left wrist showed marked degenerative changes (Figure 3), including the following:

  • Erosive changes involving the ulnar half of the distal articular surface of the radius.
  • Several synovial cysts in the styloid process of the radius.
  • Synovial cysts in the navicular, capitate, and distal ulnar head.
  • Marked joint space narrowing between the radius and the navicular.
  • Narrowing and irregularities between the lunate, the distal radius, and the ulna.
  • Synovial cyst in the proximal articular head of the metacarpal of the thumb.

Figure 2. MRI of the cervical spine showing atrophy of the spinal cord at the cervicothoracic junction.

Figure 3. MRI of the left wrist showing multiple cysts in the capitate and radius and narrowing of joint spaces with erosive changes involving the ulnar half of the distal articular surface of the radius.

He was further evaluated by an interdisciplinary team of hand surgeons specializing in SCI, a physiatrist, and an occupational therapist. Differential diagnosis included osteoarthritis and other rheumatoid disorders and infectious processes such as septic arthritis and osteomyelitis. The patient remained afebrile, and the normal white blood cell count and borderline high sedimentation rate ruled out infection or rheumatoid condition. The patient did not have a history of diabetes mellitus, and the MRI of the spine was negative for syringomyelia. Because the patient had decreased sensation in his left hand since the onset of his SCI and considering that the patient was wheelchair dependent because of paraplegia, the most appropriate diagnosis seemed to be neuroarthropathy caused by overuse and continuous micro-trauma that the patient was probably sustaining while using his manual wheelchair and with transfers. The treatment recommendations were to avoid repetitive movement of his wrist as much as possible, to wear a wrist splint, to consider use of either a power-assist manual wheelchair or a power wheelchair, and to use a van to avoid multiple car transfers during the day. To date, the patient has chosen to wear a static wrist splint and not pursue further intervention.

DISCUSSION

Neuroarthropathies are felt to be more common in weight-bearing joints, such as the knee, hip, foot, and ankle (1,4). The most common joints to be affected in diabetes mellitus are the tarsometatarsal and metatarsophalangeal joints, whereas the non–weight-bearing hand and wrist joints are rarely affected (1). Bayne and Lu (1) reported one case of neuroarthropathy in the wrist in an individual with diabetes mellitus who was using crutches after a lower extremity amputation. This individual was felt to have developed neuroarthropathy in his wrist because of weight bearing in his upper extremity as he used crutches. Deirmengian et al (3) reported 5 cases of neuroarthropathy of the elbow in individuals with syringomyelia, renal disease, and polyneuropathy. In the SCI population, there are very few reports of neuroarthropathies in the upper extremity (6). Barber et al (6) reported a case of neuroarthropathy in the shoulder in an active individual with tetraplegia who had developed syringomyelia.

The exact pathogenesis of neuroarthropathies is unclear. One theory, the “neurotraumatic” theory, postulates that the normal pain mechanism is deactivated by articular denervation, allowing repetitive trauma to occur (1). If the joint remains unprotected, it sustains rapid destruction, hemarthrosis, synovial thickening, and secondary ligament laxity (11). The second, and less accepted, theory is the “neurovascular” theory, which postulates that the underlying neurologic changes lead to hypervascularity in subchondral bone (1). There may be extensive erosion of the bone, increased bone resorption, bone weakening, microfractures, and subchondral collapse and destruction of the joint (12).

Three stages of neuroarthropathy progression have been described (12). The initial developmental or hyper-vascular stage is defined by joint laxity, subluxation, osteochondral fragmentation, and debris formation. The second stage, “coalescence,” is characterized by absorption of debris, fusion of large bone fragments, subchondral sclerosis, eventual avascular necrosis, and formation of new bone over the dead trabeculae (12). During the third phase, reconstruction and remodeling, the joint shows restoration of the joint structure with fusion after revascularization in the area. By the first time this patient reported his symptoms to our clinic, his clinical presentation was most consistent with the second stage. Because he is developing contracture of his wrist with decreased swelling and warmth with the most recent examination, his current clinical presentation may now be more consistent with the third phase, with gross joint fusion.

Radiographically, neuroarthropathies have been described as “atrophic” or “proliferative” (1). The atrophic form has substantial bone resorption and near disintegration of the joint, and these changes are often asymptomatic (12). The proliferative form, which is the more common type, is characterized by significant joint destruction, periarticular new bone formation, bony fragmentation and fracture, osteophyte formation, and ultimately fusion (12). The presence of cartilaginous and osseous debris deep in the synovium differentiates neuroarthropathy from the more common osteoarthritis, in which debris is usually found below the synovial lining (13). In this case, given that the patient's presentation was most consistent with neuroarthropathy, further evaluation with biopsy was considered but not felt to be clinically indicated nor would change the management of the patient. The MRI and radiological findings with the given medical history in this case suggested neuroarthropathy, presumed secondary to repetitive trauma to the left wrist, which had decreased sensation, consistent with the “neurotraumatic” theory.

The incidence of neuroarthropathy is thought to be about 0.1% in individuals with diabetes mellitus, and the onset occurs approximately 15 years after the diagnosis of diabetes (12). The incidence of neuroarthropathy in individuals with SCI is unknown. The incidence of symptomatic posttraumatic syringomyelia in SCI is reported to be about 1.3%, and it is estimated that 20% to 25% of the patients with syringomyelia develop neuroarthropathies (6). The shoulder joint is expected to be more susceptible to repetitive trauma injuries than the elbow or wrist joints, which are considered more stable joints than the shoulder. In this case, the patient did not have syringomyelia but had an atrophy of the spinal cord at the cervicothoracic junction.

In general, treatment is aimed at reducing further articular damage while retaining a functional joint. This may involve orthotics, weight-bearing reduction techniques, and patient education to minimize mechanical trauma (6). For the elbow, an internal fixation has been performed with some success (3), but it is usually not recommended for neuroarthropathy of the feet in diabetes (12). Surgical repair and combined anterior and posterior stabilization of the spine is recommended for Charcot spine in individuals with SCI (5). Previous treatment options that have been considered for the shoulder include humeral head prosthetic replacement (6). Treatment recommendations that were made in this case were to avoid repetitive movement of the wrist by wearing a wrist splint, to consider either a power-assist manual wheelchair or a power wheelchair, and to use a van to avoid multiple car transfers during the day. Because the treatment options for neuroarthropathy in the upper extremity in individuals with SCI are limited, early diagnosis is crucial to implement conservative management before significant destruction of the joint occurs.