Carpal tunnel decompression through the flexor carpi radialis approach: a cadaveric comparative study

Carpal tunnel syndrome may occur in association with distal radial fractures, and decompression is sometimes considered at the time of fixation. The flexor carpi radialis approach used for anterior plating may allow decompression without extending the incision into the palm. This study compared intracarpal canal pressure reduction achieved through this approach and the standard technique.

Twelve fresh-frozen upper extremities were studied. Within each pair, one limb underwent carpal tunnel release through the flexor carpi radialis approach and the contralateral limb through a standard open palmar incision. A balloon-tipped catheter connected to a pressure transducer was inserted proximal to the wrist crease and advanced distally to measure pressure at 5 mm intervals. The peak-pressure site was identified and used for measurements in the neutral position and during wrist flexion and extension. Measurements were obtained before and after release. Final dissection assessed completeness of release and iatrogenic injury.

Pressure increased distally, peaking at 114 (SD 70) mmHg approximately 29 (SD 5) mm distal to the wrist crease, near the hook of the hamate. Pressure increased with both flexion and extension, with higher values in extension (201 (SD 12) mmHg) than flexion (133 (SD 17) mmHg,). Both techniques reduced pressure in the neutral position by approximately 75-85 mmHg. Complete release was confirmed in all specimens without tendon or nerve injury.

The flexor carpi radialis approach provides pressure reduction comparable to the standard open technique and may allow decompression without a separate palmar incision.