Effect of different positions of splinting on flexor tendon relaxation: a cadaver study.

We performed a cadaver study to evaluate how six different static heat-moulded splints affect flexor tendon relaxation. Each splint positioned the wrist and metacarpophalangeal (MCP) joints in different positions. We evaluated the tendon relaxation in 12 fresh adult cadaver forearms by measuring the flexor tendon displacement between two solid markers for each splint. The wrist position ranged from 30° flexion to 45° extension and the MCP joints from 30° to 60° flexion. For each splint, tendon relaxation was achieved relative to the neutral reference position. Tendon relaxation was greatest when the MCP joints were positioned in 60° flexion. We also noted the persistence of tendon relaxation when the wrist was positioned in extension (30° or 45°) as long as MCP joint flexion was maintained (30° or 60°). We conclude that the wrist extension with the MCP joints flexion may optimize tendon relaxation during immobilization after flexor tendon repairs.