Peripheral tears of the meniscus. The effect of open versus arthroscopic repair on intraarticular contact stresses in the human knee.

The mechanical properties of the repaired meniscus may affect its ability to heal and to protect the articular surface against degenerative changes. We compared the immediate biomechanical consequences of open versus arthroscopic repair in the human cadaver knee. Additionally, having measured postoperative stresses at various degrees of knee flexion, we have addressed the effect of tethering of the meniscus, a question relevant to both meniscus repair and replacement. Peak stresses were measured by the Pressensor system. Fresh human cadaver knees were subjected to loading in an Instron unit, on an unconstrained base. Instantaneous loads were applied with the knee in 0 degree, 30 degrees, or 60 degrees of flexion, and stress distributions were measured after repair of a 2 cm peripheral tear, by an open or arthroscopic approach. The results of loading experiments on five knees revealed no statistically significant differences between stresses after the two repairs. Similarly, there was no statistically significant difference between the normal and repaired menisci. In our model, this suggests that the immediate biomechanical consequences of open and arthroscopic repair are equivalent and that the "tethered" meniscus distributes loads as well as the normal meniscus.

Pronator syndrome.

Although pronator syndrome is often misdiagnosed and does not occur as frequently as carpal tunnel syndrome, its clinical features are well described, and the diagnosis should be made if the clinical features are understood and reasonable suspicion exists. The differentiating features between carpal tunnel syndrome and pronator syndrome should be understood, and evaluation for one site of compressive neuropathy of the median nerve always should include the other potential sites. When the correct diagnosis is made, pronator syndrome can be successfully treated nonoperatively or surgically, if necessary.

A comparison of plate and pin fixation for arthrodesis of the rheumatoid wrist.

This retrospective study compared plate fixation versus pin fixation in 57 patients with rheumatoid arthritis who underwent wrist arthrodesis. Fixation was achieved by using plates in 32 patients and longitudinal pins in 25 patients. Clinical follow-up averaged 29 months (range: 12-57 months) and radiographic follow-up averaged 16 months (range 12-39 months). Union occurred in 97% of the wrists fixed with plates and in 96% of the wrists fixed with pins. There were 6 (19%) complications in the plate group and 7 (28%) complications in the pin group. Three (12%) wrists fixed with pins moved from the immediate postoperative position to a position of relative volar flexion, while radiographs showed no changes in wrist position in the plate group. With both methods, successful arthrodesis stabilized the wrist in a high percentage of patients. Plate fixation offers an excellent alternative method for arthrodesis of the rheumatoid wrist.

The Mitek bone anchor: application to the hand, wrist and elbow.

Mitek (Norwood, MA) bone anchors were used to attach soft tissue to the bones of the hand, wrist, and elbow in 66 procedures (166 anchors). The technical difficulties, initial fixation, long-term stability, and postoperative complications were retrospectively reviewed. The technique was easy to learn and to use. Intraoperatively, secure fixation of soft tissue to bone was accomplished in every case, and follow-up x-ray films showed that 65 of the implants remained securely anchored in bone. The far cortex was penetrated six times, resulting in two complications. The Mitek bone anchor is an excellent technique for achieving soft-tissue fixation in the hand and upper extremity, but penetration of the far cortex should be avoided.