Polyurethane versus silicone for endoprosthetic replacement of the metacarpophalangeal joints in rheumatoid arthritis.

In a prospective study 12 patients with rheumatoid arthritis underwent arthroplasty of four metacarpophalangeal joints. Two different implant materials were randomly used in each hand, polyurethane (Pellethane) or silicone (Silastic). Eleven patients with 44 (21 silicone; 23 polyurethane) implants were re-examined 4.5 years (range 3-5) postoperatively. No difference was found between the implant materials regarding pain, stability of the joint or recurrence of the ulnar drift. The mean range of motion was 41 degrees (range 20 degrees-70 degrees) in the polyurethane joints compared with 42 degrees (range 15 degrees-90 degrees) in the silicone joints. The extension deficit was more pronounced in the silicone (mean 11.4 degrees) than in the polyurethane (mean 5.8 degrees) joints, and clinical signs of synovitis around the implants were more common with the silicone arthroplasties. Radiographic analysis, performed with conventional radiography and computed tomography (CT) showed one implant fracture in each group. There was a more pronounced bone resorption around silicone implants, but more sclerosis around polyurethane implants. Bony spurs interfering with function of the implant were common with both materials.

The correlation between controlled range of motion with dynamic traction and results after flexor tendon repair in zone II.

This prospective study investigated the extent to which the range of interphalangeal joint motion during early mobilization with dynamic traction influences the results after flexor tendon repair in zone II. The controlled interphalangeal joint range of motion within the splint was measured 3 weeks postoperatively in 51 digits (48 patients). The active range of motion was measured 4 weeks, 6 weeks, and 1 year postoperatively. Linear regression analysis showed that controlled interphalangeal range of motion had a significant effect on both early and late results. The results provide, for the first time, firm clinical evidence to support the rationale for early mobilization programs designed to maximize controlled interphalangeal joint range of motion.

Controlled mobilization after flexor tendon repair in zone II: a prospective comparison of three methods.

A new controlled-motion program that incorporates dynamic flexion traction to all four digits, a short splint leaving the interphalangeal joints free, and a nighttime extension splint was prospectively compared with a modification of the Kleinert technique and a combination of the modified Kleinert technique and passive movements. Each program was applied to approximately one third of 178 consecutively treated digits with tendon injuries in zone II. The mean total active interphalangeal joint range of motion 6 weeks and 1 year postoperatively was significantly better and extension deficits were significantly less frequent in the digits mobilized with the new program. The postoperative treatment input, in terms of frequency of reviews and time spent in therapy sessions, is not greater than with more traditional controlled-motion programs. Our results indicate that the new program is a safe, reliable, and cost-effective method that produces very good results in a general population.