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Single versus Double Ball Interposition Arthroplasty with Trapeziectomy for Basal Thumb Arthritis : Retrospective Radiological Outcome Follow Up

Carpometacarpal (CMC) joint or Trapeziometacarpal (TMC) joint is the second most common site of hand osteoarthritis. Following trapeziectomy, ligament reconstruction with tendon interposition (LRTI) is considered a “gold standard” treatment. Currently, there is no objective radiographic study to determine whether single ball (SB) or double ball (DB) flexor carpi radialis (FCR), under ligament reconstruction with tendon interposition, whichever is more effective against atrophy of metacarpal bone of thumb.

This study is a retrospective review of 20 patients (10 SB, 10 DB) interposition with FCR ligament reconstruction that had at least 1 year of radiographic follow-up following thumb CMC arthroplasty. Posteroanterior radiographs at timepoint were evaluated for actual preoperative height of the trapezial void (HT1) vs height of the trapezial void at 1 year (HT2), preoperative first metacarpal subluxation (MS1) vs first metacarpal subluxation at 1 year (MS2), as well as preoperative first metacarpal migration (MM1) vs first metacarpal migration at 1 year (MM2).

Patients undergoing DB interposition with FCR ligament reconstruction had significantly improved for height of the trapezial void at 1 year (HT2) (mean difference -2.98 [-5.22 to -0.74], P < 0.05). However, there were no significant differences for first metacarpal subluxation at 1 year (MS2) (mean difference -0.6 [-3.45 to 2.25], P = 0.663) as well as first metacarpal migration at 1 year (MM2) (mean difference 2.80 [-1.43 to 7.02], P  = 0.181).

Thumb basal joint arthritis performed with a DB interposition with FCR ligament reconstruction versus SB interposition yielded short-term improved height of the trapezial void, and no difference in first metacarpal subluxation and first metacarpal migration.

thumb basal joint, arthritis, ligament reconstruction, tendon interposition, ball, single, double