There has been few published on arthroscopy of metacarpophalangeal joint (MCPJ) despite increasingly being used worldwide. The purpose of this study was to investigate the effectiveness of arthroscopy for pathologies around MCPJ of the thumb.

Between September 2007 and June 2015, 56 patients (56 thumb) who underwent arthroscopy of the MCPJ were retrospectively studied. Preoperative diagnoses, which were made through physical examination, plain radiograph, stress radiography, ultrasound, and magnetic resonance images (MRI), were compared with arthroscopic findings. Therapeutic arthroscopic surgeries were performed according to the needs of each patient. Functional outcomes were assessed with physical examination as well as disabilities of the arm, shoulder and hand (DASH) score and Michigan Hand outcomes Questionnaire (MHQ) score at an average 7.3 months follow-up.

Six patients who suspected with collateral ligament injuries in MRI confirmed different diagnoses under arthroscopy. At final follow-up, the mean range of flexion contracture of the MCPJ was 5°, and the mean range of further flexion was 52.7°. Grip and pinch strength averaged 87.2% and 79.3% of contralateral side. Mean DASH and MHQ score were improved from 48.1 and 44.6, preoperatively to 14.9 and 26.3, postoperatively (p<0.001, p=0.012, respectively). All patients were satisfied with their outcomes at final follow-up, except 4 patients who noted joint stiffness or chronic pain around the thumb.

Our results revealed that arthroscopy is helpful for both diagnostic and therapeutic purposes of acute and chronic painful MCPJ of the thumb. However, further studies are needed to expand the applications of arthroscopy of MCPJ of the thumb.