gms | German Medical Science

Objectives/Interrogation: Osteophyte formation is a critical part of the degeneration of a joint with osteoarthritis (OA). While often qualitatively described, few studies have succeeded in quantifying osteophyte growth over time. In a longitudinal, observational study of thumb carpometacarpal (CMC) OA, our aim was to quantity osteophyte growth volume and location over a three-year period in men and women.

Methods: Ninety patients with early thumb OA were recruited and assessed at baseline, 1.5 years and 3 years. CT volume images were collected and the osteophyte volume and location on the trapezium and metacarpals were determined using 46 healthy controls as a reference database.

Changes in growth over time and between sexes were assessed with two-way repeated ANOVA.

Results and Conclusions: There was a significant increase in osteophyte volume in both women and men over the three-year follow-up. At year three, after accounting for the larger bones, men still had larger osteophyte growth than women. The location of osteophyte growth initiation was consistent and non-opposing on each bone. Osteophyte growth occurred on the radial and ulnar margins of the trapezial facet, while on the MC1, growth occurred principally on the volar and dorsal margins of the facet.

Osteophyte growth occurred in early thumb osteoarthritis over three years. Growth was localized in non-opposing regions on the trapezium and on the metacarpal, raising questions about the etiology underlying osteophyte initiation and growth in osteoarthritis. Men having greater osteophyte growth may cause motion constraint and thereby less pain when compared to women (Figure 1 [Fig. 1]).