Rebalancing of forces as an adjunct to resection suspension arthroplasty for trapezial osteoarthritis.

Overview

The carpometacarpal (CM) joint of the thumb is commonly affected by osteoarthritis. The strength required for a first CM ligament reconstruction depends on the forces across the joint. If these forces are rebalanced to reduce the requirements necessary to prevent subluxation, reconstructive requirements are lowered and surgical dissections reduced. A method to achieve this goal based on Landsmeer's zig-zag compression concept is presented. Fifteen consecutive patients (11 women; mean age, 63 years) with pantrapezial osteoarthritis were selected over a 2-year period to undergo this novel procedure. After standard trapezial resection, trapezoidal hemiresection was performed, allowing for medial movement of the first metacarpal base. Following the zig-zag concept, the first metacarpophalangeal joint reciprocally fell into flexion, decreasing forces causing subluxation of the first metacarpal base. A saddle-like suspension under the metacarpal base was created using the trapezial capsule. All 15 patients had excellent outcomes with elimination of pain, early recovery of mobility and power, and no recurrent subluxations. The durability of the procedure was confirmed clinically and radiologically. The medial relocation of the first metacarpal base rebalances and attenuates the normal deforming forces thereby eliminating the need for a strong CM ligament reconstruction.