Arthroscopic Proximal Trapeziotrapezoid Resection for STT Osteoarthritis

Background: The most common treatment for scaphotrapeziotrapezoid joint (STTj) osteoarthritis (OA) is resection arthroplasty of the distal scaphoid, with or without prosthetic interposition. However, this procedure shows a considerable amount of unsatisfactory results related to the progression of dorsal intercalated segment instability (DISI) carpal malalignment. Similar complications result even when an arthroscopic approach is used, which is also a technically demanding procedure. To overcome these drawbacks and reduce ligamentous damage around the STTj, we developed an arthroscopic technique that consists of resection of the proximal aspect of trapezium and trapezoid: distal STTj resection arthroplasty (dSTT/RA)

Methods: The dSTT/RA technique was used in 12 cases (1 bilateral) from 2009 to 2013. Average age was 62 years (range 32–73). Patients were 2 males and 9 female. The technique was performed using midcarpal radial (MCR) and STT portals with standard setup for midcarpal arthroscopy. After extensive synovectomy and osteophyte resection, 3 to 4 mm of resection was performed using a motorized burr to expose the subchondral bone and preserve the ligamentous attachments around the STTj. Patients were evaluated for wrist range of motion (ROM), pain (10-point visual analog scale [VAS]), grip and pinch strength, Modified Mayo Wrist Score (MMWS), and DISI evolution. Subjective outcome was investigated with quickDASH (Disabilities of the Arm, Shoulder, and Hand) and Patient-Rated Wrist/Hand Evaluation (PRWHE).

Results: No intraoperative complications were recorded. Resection of the palmar aspect of the trapezium allowed visualization of the flexor carpi radialis (FCR) tendon sheath. FRC synovectomy was performed in nine cases up to the trapezial groove. FRC was débrided for partial laceration in three cases and resected, due to massive laceration, in two cases. After a mean follow-up of 2.7 years, all patients reported a functional improvement of their hand. ROM was 96% of the contralateral side. Mean pain VAS score was 3 (occasional pain in three cases). Grip and pinch strength accounted for 85% and 90% of the contralateral side, respectively. MMWS was excellent in 10 patients (including bilateral) and fair in one. DISI increased in nine patients, though less than 10°, and was not related to any clinical impairment. QuickDASH and PRWHE scored 27.8% and 5%, respectively. Transient irritation of the dorsal branch of the radial nerve was observed in two cases.

Concusions: The dSTT/RA technique shows itself to be a valuable option to relieve symptoms and restore normal hand function in STTj OA. The arthroscopy overcomes the difficulties of an open approach to the proximal aspect of the trapezium and trapezoid and allows the surgeon to shape the resected surfaces along the contour of the distal scaphoid. Furthermore, due to different bone characteristics, resection of the trapezium and trapezoid is an easier and faster procedure than distal scaphoid resection. Approach to the distal aspect of the STT also allows débridement and decompression of the FCR. Early results are encouraging, though larger series and longer long-term follow-up are needed.