Minimally Invasive Endoscopic Palmaris Longus Abductorplasty for Severe Carpal Tunnel Syndrome and Thenar Muscle Paralysis Reconstruction

Functional deficits in severe carpal tunnel syndrome arise from a combination of persistent diminished sensation and thenar muscle paralysis, leading to the disruption of thumb kinematics. Decompression alone does not address thenar atrophy. To restore thumb function, tendon transfers from donors, such as the palmaris longus, have been described. However, palmaris longus abductorplasty has disadvantages, including extensive dissection and large wounds, which increase the risk of higher morbidity, scarring, increased pain, and delayed rehabilitation. We introduce a minimally invasive endoscopic technique of tendon harvest for thenar abductorplasty to minimize morbidity. This technique can be used with a simultaneous endoscopic carpal tunnel decompression. The average surgical time was 47 minutes for combined endoscopic carpal tunnel decompression and tendon transfer procedures. The final outcomes at 6 months showed a pinch strength of 1-3.5 kgF, or 74.8% of the contralateral side. The introduction of the endoscopic technique for tendon transfer heralds a new direction in minimally invasive surgery.