METHODS: Ten fresh-frozen cadaver specimens were randomly assigned to undergo joint preparation using either an osteotome (n=5) or saw (n=5). Sample size was determined by cadaver availability. Fusion was performed using a cross-screw construct through the dorsal aspect of the proximal phalanx and the medial cuneiform. Pre- and post-operative X-rays were taken with a radiopaque ruler in the field, and changes in length in the first metatarsal and first cuneiform were compared between osteotome and sawblade groups.
RESULTS: The average change in metatarsal length was significantly smaller in the osteotome group (1.6mm) as compared to the saw group (4.4mm) (p=0.031). The average percent change in metatarsal length was also significantly smaller in the osteotome group (3.0%) compared to the saw group (8.4%) (p=0.025). There was no significant difference between the two groups with respect to change in cuneiform length. The osteotome group demonstrated a significantly smaller average measured change (3.0mm vs. 6.9mm, p=0.001) and percent change (4.1% vs. 9.3%, p<0.001) in total length (cuneiform plus metatarsal) in comparison to the saw group.
CONCLUSIONS: In first TMT fusion, joint preparation with an osteotome may prevent over-shortening of the first ray in comparison to preparation with a saw.