First Carpometacarpal Joint Anatomy and Osteoarthritis: MR Imaging Overview

The first carpometacarpal (CMC) joint consists of seven ligaments. The magnetic resonance imaging (MRI) examination of the first CMC joint should be performed in a high field 1.5/3 T MRI with a dedicated hand coil for high-resolution images. Degeneration of anterior oblique ligament (AOL) is the most important cause for the development of osteoarthritis of first CMC joint. Since the AOL undergoes a predictable pattern of alteration at its metacarpal attachment as degeneration proceeds, MRI imaging can provide an accurate assessment of this ligament.

Functional outcome of ligament reconstruction with tendon interposition after failed first carpometacarpal joint prosthesis

The purpose is to determine if ligament reconstruction with tendon interposition (LRTI) is a recommendable salvage option for failed total joint prosthesis of the first carpometacarpal joint. Twenty-two patients in our database met the in- clusion criteria for this retrospective study, with at least 6 months follow-up. Fourteen participated and were invited for a clinical examination and asked to fill out two questionnaires. They were evaluated for pain (VAS), impairment (NHS), disability (Quick DASH), opposition (Kapandji test) and grip strength (hydraulic dynamometer). Results of the questionnaires were compared to a cohort study of primary LRTI’s. Kapandji test and grip strength were compared to the contralateral side. Compared to primary LRTI’s, revision surgery showed mild deterioration of impairment and disability. The average VAS score was 2.9 out of 10. Twelve patients mentioned a sense of strength loss, which could be quantified with the dynamometer : a mean of 15.1 kg (operated thumb) versus 20.5 kg (contralateral). There was a relatively small decline of opposition with Kapandji 8.6 versus 9.9. The overall satisfaction was good for 8 patients, fair for 3 and poor for the remaining 3 (mainly based on strength loss). One patient needed a second revision. Failed first carpometacarpal joint replacement can be salvaged by ligament reconstruction with tendon interposition, providing an acceptable functional outcome in 79% of cases studied. However, compared to the functional outcome of primary LRTI’s, mild aggravation of impairment and disability should be taken into account.

Mechanical thumb pain in a systemic sclerosis patient: simple first carpometacarpal osteoarthritis?

A 70-year-old female patient treated with methotrexate for diffuse cutaneous systemic sclerosis (SSc) came up with mechanical pain over the left thumb for several months. SSc was diagnosed based on a clinical picture associating puffy fingers, skin sclerosis, wrist arthralgia, pulmonary hypertension, presence of antinuclear factors and antibodies against Topoisomerase-I. Her complaint was attributed to first carpometacarpal joint osteoarthritis and treated with orthesis, which did not provide pain relief after 5 months of regular use. Hand radiograph showed first carpometacarpal arthropathy with joint space narrowing and marked sclerosis of the first proximal metacarpal (A). MRI showed an area of very low signal intensity on T1- and T2-weighted images (B) within the proximal metacarpal, distal trapezium and medial joint recess surrounded by bone marrow edema. Mild peripheral enhancement was present after gadolinium injection. CT-scan (C) showed that the low signal intensity material visible at MRI consisted of calcium. These aspects are suggestive of scleroderma arthropathy rather than common first carpometacarpal osteoarthritis. Though involvement of the first carpometacarpal joint is long time known in SSc [1], it remains exceptional when looking at cross-sectional studies [2]. Carefully analyzing imaging exams is the key point in order not to miss this rare scleroderma feature.

The influence of K-wire transfixation on proximalization of the first metacarpal after resection suspension interposition arthroplasty

Introduction Osteoarthritis of the first carpometacarpal joint is a common degenerative disease and surgical treatment includes resection suspension interposition arthroplasty (RSIA) with or without temporary transfixation of the first metacarpal. One major drawback includes proximalization of the first metacarpal during the postoperative course. Specific data comparing different transfixation techniques in this context is sparse. Materials and methods In this retrospective study, we measured the trapezial space ratio (TSR) in 53 hands before and after RSIA to determine the proximalization of the first metacarpal depending on the type of Kirschner (K)-wire transfixation. We, therefore, compared transfixation of the first metacarpal to the scaphoid with one K-wire (1K) to transfixation of the first metacarpal with two K-wires (2K), either to the carpus (2Ka), or to the second metacarpal (2Kb), or to both second metacarpal and carpus (2Kc). Results While preoperative TSR did not differ between group 1K and 2K (p = 0.507), postoperative TSR was significantly higher in group 2K compared to 1K (p = 0.003). Comparing subgroups, postoperative TSR was significantly higher in group 2Kc than 1K (p = 0.046), while we found no significant difference comparing either group 2Ka or 2Kb to 1K (p = 0.098; p = 0.159). Neither did we find a significant difference within 2K subgroups, comparing group 2Ka and 2Kb (p = 0.834), 2Ka and 2Kc (p = 0.615), or 2Kb and 2Kc (p = 0.555). Conclusions The results of our study suggest that transfixation with two K-wires should be preferred to transfixation with one K-wire after RSIA. Specifically, transfixation from first to second metacarpal and from first metacarpal to carpus resulted in least proximalization of the first metacarpal postoperatively.