Purpose The purpose of this study was to evaluate whether removing the proximal trapezoid from the scaphotrapezoid joint (STJ) and interposing tendon when performing a ligament reconstruction and tendon interposition (LRTI) for pan trapezial arthritis resulted in any clinical or radiographic compromise compared with LRTI alone in isolated carpometacarpal joint arthritis.

Methods In a prospective consecutive cohort, 122 thumbs were selected to generate two matched cohorts and a cross-sectional review was completed at an average of 24 months (range: 5–203 months). Fifty-six thumbs had LRTI alone and 66 thumbs also had resection of the proximal portion of the trapezoid with tendon interposition in the residual gap.

Results The cohorts showed no significant differences in subjective and objective outcome measures and imaging. Excision of the STJ was not associated with poorer clinical outcomes or the development of a dorsal intercalated segment instability deformity.

Conclusions The management of pan trapezial arthritis with LRTI and proximal trapezoid excision and STJ interposition appears satisfactory on short- to medium-term clinical and radiographic follow-up.