Lunate implant arthroplasty. Evaluation of 19 patients

Long-term outcome (22-36 years) of silicone lunate arthroplasty for Kienbock's disease

Silicone lunate arthroplasty for Kienböck's disease was abandoned several years ago due to severe silicone cyst formation. We identified 53 patients and retrospectively evaluated short-term radiological and clinical results, as well as long-term radiological outcome, pain relief, range of motion, strength, and functional results, a mean 27 years after surgery. The incidence of silicone cysts was 78%. Twelve implants were removed - three due to implant dislocation and nine due to silicone synovitis - and six wrist joints were fused. Pain on the visual analogue scale averaged 2.2 at rest and 5.4 during heavy exertion. Range of motion of those wrists not fused reached 65% of that of the contralateral wrist, and strength of all wrists reached 72%. Those few patients who developed no silicone cysts by 10 years post-operatively will not form cysts and will retain their satisfactory clinical, functional, and radiological result. These very long-term results confirm that silicone lunate arthroplasty should not be used for Kienböck's disease.

External fixation and cancellous bone grafting for Kienböck's disease: a preliminary report

Between 1985 and 1990, 17 patients with histologically proven Kienböck's disease (Lichtman stages I, II, and III) underwent a combination of cancellous bone grafting to the lunate and external fixation across the wrist. All 17 patients were available for review with a minimum follow-up of 2 years (average, 47 years). Based on pain, functional status, range of motion, and grip strength (Mayo wrist score), there were 6 excellent, 6 good, 2 fair, and 3 poor results (2 of whom required further surgery). An overall success rate of 71% (12 of 17) was achieved. Ten patients underwent postoperative magnetic resonance scanning, and in 5, some improvement in signal intensity was demonstrated. The combination of cancellous bone grafting and external fixation is an alternative treatment for Kienböck's disease.

Silastic Replacement of the Trapezium for Arthrosis—A Twelve Year Follow-Up Study

Thirty-three patients with 39 Swanson silastic trapezium implants have been studied. Three years after operation no dislocation or evidence of implant wear was found, but re-examination at an average of 12 years after operation revealed dislocations and implant wear in about half of the cases. Cyst formation in surrounding carpal bones was found in twenty cases. The result in terms of pain relief and thumb function was good and comparable to the three-year follow-up. A significant correlation was found between weakness of the pinch grip and dislocation of the implant. No correlation was found between pain and dislocation of the implants, nor between pain and presence of intraosseous cysts.

Deterioration of temporary silicone implant in the temporomandibular joint: a clinical and arthroscopic follow-up study

Dacron-reinforced silicone material was used as a temporary disk replacement implant in twenty-seven consecutive patients who underwent diskectomy. Symptoms and the status of the implants were recorded when the implants were removed 1 to 19 months postoperatively (median, 4 months). At the time of removal of the implants, eleven patients showed mechanical dysfunction, which was associated with pain in four patients. All but one of the implants showed wearing facets, and fifteen implants were cracked or perforated. Arthroscopic examination was performed when the implant was removed in the last six patients. This revealed that the extension of the joint compartment corresponded well to the dimension of the implant. Arthroscopy also disclosed that initially even and shiny articular surfaces remained so, articular surfaces in joints with fibrous ankylosis became shiny but uneven, and arthrotic articular surfaces showed no changes. It was concluded that disk-replacement implants can prevent postoperative ingrowth of fibrous tissue and development of intra-articular adhesions and that the implant has the capacity to protect the articular surfaces as long as the material is intact. Since more than half of the implants were cracked or perforated, an implant material with mechanical properties superior to those of Dacron-reinforced silicone would be preferable.

Silicone carpal implants: risk or benefit?

The present report is based on assessment of 48 patients who underwent carpal Silastic H.P. implant arthroplasty (trapezium, condylar, scaphoid, lunate and scapholunate implants). Mean follow-up period was 29 months (range 6-82). Recurrent pain and/or evidence of wrist synovitis and lytic lesions made early subsequent surgery necessary in 10 patients. In the remaining 38 patients the post-operative course was followed for an average period of 33 months (range 8-82). Severe giant-cell silicone synovitis combined with isolated or disseminated osteolytic lesions were found in 17/30 (56%) patients with scaphoid or lunate implants and in 2/18 (11%) with other types of Silastic carpal implants. Well-defined cysts were observed within 8 months of insertion of the implant. Morphologically, an erosive giant-cell synovitis was regularly seen, with large quantities of intra- and extracellular silicone debris. Abraded material was also observed in central parts of normal bone and in lymph node tissue distant from the implant. The ultimate tissue response to this propagation of silicone particles is unknown. The situation is of great concern and the continued use of proximal carpal Silastic H.P. implants should at present be seriously questioned.