Patellar tendon rupture in systemic lupus erythematosus.

We investigated the frequency of patellar tendon rupture in our patients with systemic lupus erythematosus (SLE) in order to characterize the features that might predict rupture and compared our experience to that described in the literature. Four of 180 patients with lupus seen in the last 10 years had patellar tendon rupture. Duration of disease ranged between 7-20 years. Each patient was in clinical remission at the time of rupture. Each patient also had deforming arthritis of the hands. All had been taking prednisone from 7 to 15 years and all had side effects associated with prednisone therapy, such as moon facies, compression fractures and osteonecrosis. Review of the literature reveals 17 patients with tendon rupture. All had disease of long duration, had been taking corticosteroids for prolonged periods and had minimal or no disease activity at the time of rupture. Deforming hand arthropathy was present in all patients, when mentioned. No cases of tendon rupture had been reported in patients not taking chronic corticosteroid therapy. Therefore, tendon rupture in SLE appears to be associated with extended disease duration, chronic corticosteroid therapy, evidence of steroid induced musculoskeletal complications, minimal disease activity and deforming hand arthropathy.