Osteolysis with detritic synovitis: Appearance in a patient with connective tissue disease

Authors


Introduction

Osteolysis is defined as the destruction of bone, particularly by bone resorption, with the removal or loss of calcium. Osteolysis has been reported in countless metabolic, traumatic, vascular, neoplastic, congenital, articular, and infectious disorders. The syndrome of osteolysis with detritic synovitis was first described in 1978 as an idiopathic, destructive, and mutilating arthropathy with widespread resorption of bone, accompanied by minimal evidence of inflammatory response on bone biopsy (1). We report another patient with a similar clinical, radiologic, and pathologic picture that developed parallel to the progressive course of a connective tissue disease.

Case report

A 58-year-old white woman presented in 1996 with a 1-year history of pain, morning stiffness, symmetric swelling, and decreased range of motion of the proximal interphalangeal joints (PIPs) of both hands, wrists, shoulders, and knees. Her evaluation was positive for both rheumatoid factor (RF) and antinuclear antibody (ANA) with hand radiographs reported as negative for erosions and calcifications. With the presumed diagnosis of rheumatoid arthritis (RA), treatment with methotrexate (7.5 mg/week), hydroxychloroquine, and nonsteroidal antiinflammatory drugs was initiated. The patient felt better but developed small subcutaneous nodules on the extensor surfaces of the elbows, which resolved over the next 2 years. In 1998, she noted for the first time progressive deformity of the distal phalanges of all her fingers on both hands, accompanied by persistent pain. Hand radiographs revealed osteolysis of the distal and middle phalanges of the fingers as well as dystrophic calcification (Figure 1). Radiographs of her feet demonstrated a single erosion of the right 5th metatarsophalangeal (MTP) joint.

Figure 1.

Osteolysis of finger phalanges with calcific debris.

On reevaluation, mild Raynaud's phenomenon, normal nailfold capillaroscopy, and xerophthalmia with a positive Schirmer's test result were documented. No sclerodactyly, other skin changes, nor signs of esophageal dysmotility were noted. The patient did not have evidence of active synovitis at the time and her RF had turned negative. ANA in a speckled pattern, positive anti-Ro (SSA), low C4 levels, and diffuse hypergammaglobulinemia were found. Complete blood count, renal and liver function test results, thyroid stimulating hormone level, serum electrolyte level (including calcium and phosphorus), echocardiography, and chest and abdominal computed tomography scans (CT) were all within normal limits. A technetium bone scan revealed increased uptake in the distal interphalangeal joints (DIPs) of both hands, right talus, and 1st MTP. A higher dose of methotrexate and, later, azathioprine were administered but were ineffective in controlling bone pain.

Due to progression of osteolysis, as assessed by radiographs, a biopsy of the distal phalanx of the left 3rd finger was performed. It revealed a fragment of remodeled bone with intertrabecular fibrosis, no evidence of increased osteoclastic activity (Figure 2), but intimal thickening of small arteries with luminal stenosis (Figure 3), along with foci of calcinosis in adjacent soft tissue. After administration of alendronate (for concomitant osteoporosis) and colchicine, the patient reported cessation of finger pain. However, radiographs performed in 2003 still showed progression of osteolysis. At that time, esophageal dysmotility and scleroderma-like reduced oral aperture, without skin thickening, were noted. Fine interstitial lung disease was confirmed by high-resolution chest CT. No evidence of sclerodactyly has been noted.

Figure 2.

Remodeled bone with intertrabecular fibrosis. Hematoxylin and eosin stain; original magnification ×40.

Figure 3.

Distorted small arteries with intimal thickening and luminal stenosis. Stain for elastic fibers; original magnification ×25.

Discussion

The entity of osteolysis with detritic synovitis was first described in 1978 (1). Since that initial report, no additional cases have been published in the English literature. We report a patient with a similar pattern of clinical, radiologic, and pathologic findings with followup of 8 years. Though starting with an RA-like disease, our patient gradually developed severe, painful extensive deformities of DIPs and PIPs of both hands with findings unusual for RA osteolysis. Of interest, with the development of osteolysis, her arthritis was in reasonable control with no clinical evidence of active synovitis. Although immunosuppressive treatment was ineffective in attenuating our patient's symptoms, the administration of alendronate and colchicine brought some measure of pain relief. Eventually, the patient began showing other signs of connective tissue disease, particularly some features compatible with systemic sclerosis.

As in the first described case (1), no evidence of hyperparathyroidism, multicentric reticulohistiocytosis, trauma, or vinyl chloride exposure has been found. Different from the first described case, there is exclusive involvement of hands and feet along with evidence of connective tissue disease in our patient. Unfortunately, no synovial tissue analysis was documented by pathology. However, our patient presented with clinically active synovitis, and both the radiologic and pathologic picture (bone remodeling with intratrabecular fibrosis, paucity of inflammatory infiltrate) strikingly resemble the case of Resnick et al (1). In our case, intimal thickening of arteries, causing luminal stenosis, was demonstrated in the soft tissue close to the foci of osteolysis. We can thus speculate that chronic ischemic damage may have triggered the severe osteolysis. The finding of luminal stenosis of the digital arteries was unexpected because the patient did not have significant Raynaud's phenomenon, soft tissue ulcerations, finger tuft loss, nor sclerodactyly at the time. On the other hand, the pathogenic hypothesis of putative vasculopathy goes along well with some of the other clinical features of systemic sclerosis that appeared later: reduced oral aperture, esophageal dysmotility, and interstitial lung disease. The whole picture may be considered as one of undifferentiated connective tissue disorder, evolving into systemic sclerosis. The question as to whether patients such as this should be classified as having “systemic sclerosis sine scleroderma” has been raised recently (2). It is notable that osteolysis has been reported extensively in systemic sclerosis (3) but is rarely seen in other connective tissue disorders. The possibility that systemic sclerosis sine scleroderma manifested with extensive osteolysis in our patient is an interesting one and has not yet been reported to our knowledge. However, the simultaneous involvement of both distal and middle phalanges in contrast to distal acroosteolysis characteristic for systemic sclerosis and, especially the absence of significant Raynaud's phenomenon while bone resorption is so severe, would be unusual for systemic sclerosis.

Finally, our case demonstrates that a vasculopathy of hand arteries may lead to severe osteolysis in the absence of ischemic soft tissue changes and may be a potential explanation for the mysterious entity of osteolysis with detritic synovitis.

Acknowledgements

The authors highly appreciate the kind consultation of Prof. Donald Resnick in 2000.

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