Objective: To investigate the association between muscle mass and functional recovery in women with hip fracture.
Design: A total of 200 of 230 women with hip fracture admitted consecutively to a rehabilitation hospital were investigated in this survey study. Lean mass (LM) was assessed by dual-energy x-ray absorptiometry, 23.1 +/- 7.9 (mean +/- SD) days after fracture occurrence. Appendicular LM (aLM) was calculated as the sum of LM in arms and legs. Because metal implants (prostheses and nails) affect the regional assessment of body composition, aLM was corrected by substituting LM in the unfractured leg for LM in the fractured leg: corrected aLM = (LM in unfractured leg x 2) + LM in arms. We used two approaches to adjust corrected aLM for body size: corrected aLM divided by height squared (aLM/ht), and corrected aLM adjusted for height and fat mass (residuals). Functional recovery was assessed by using Barthel index scores.
Results: After adjustment for body size, corrected aLM was neither significantly correlated with Barthel index scores nor with the change in Barthel index scores after rehabilitation. Also, after stratification for quintiles of aLM/ht and residuals, no significant differences in functional recovery were found among the five groups.
Conclusions: LM assessed after hip fracture is not associated with functional outcome in women.