Sarcopenia and Its Association With Change of Bone Mineral Density and Functional Outcome in Old-Aged Hip Arthroplasty Patients

Aim This study aimed to investigate the relationship between sarcopenia and change in bone mineral density (BMD) and functional outcome in hip arthroplasty patients. Methods: Among the 221 patients who had undergone hip arthroplasty, 147 patients were enrolled. All patients were divided into 2 groups according to presence of sarcopenia. Bone mineral density (BMD) at hospitalization and 1-year after surgery and Barthel index was measured at the time of before injury, hospitalization, 3 months and 1-year after surgery. Results: BMD at hospitalization showed .627 ± .082 (g/cm2) in Sarcopenia and .726 ± .059 (g/cm2) in Non-sarcopenia at femur (total) site ( P < .001), .531 ± .085 (g/cm2) vs .629 ± .057 (g/cm2) at femur neck site (P=.002), .715 ± .084 (g/cm2) vs .807 ± .058 (g/cm2) at lumbar (L1-L4) site ( P < .001). BMD at 1-year follow-up period, Sarcopenia showed .626 ± .082 (g/cm2) and Non-sarcopenia showed .725 ± .060 (g/cm2) at femur (total) site ( P < .001), .530 ± .085 (g/cm2) vs .629 ± .058 (g/cm2) at femur neck site ( P < .001), .715 ± .084 (g/cm2) vs .806 ± .058 (g/cm2) at lumbar (L1-L4) site ( P < .001). Change of BMD showed −.01 ± .25% for Sarcopenia and −.15 ± .47% for Non-sarcopenia in femur (total) site (P=.089), −.08 ± .63% vs −.01 ± 1.01% in femur neck site ( P = .058), .00 ± .09% vs −.12 ± .33% for each group in lumbar (L1-L4) site ( P = .052). Barthel index score showed 79.94 ± 5.66 for Sarcopenia and 84.74 ± 5.36 for Non-sarcopenia at pre-injury status ( P < .001), 33.89 ± 4.94 vs 33.87 ± 5.36 at the time of hospitalization ( P = .977), 57.42 ± 7.19 vs 60.06 ± 5.39 at 3 months follow up ( P = .015), 73.86 ± 5.94 vs 80.71 ± 4.81 for each group at 1-year follow up ( P < .001). Conclusions: Our study found that the sarcopenia showed lower BMD than the non-sarcopenia, but there was no significant difference of BMD change in the follow-up period. In addition, the sarcopenia showed poor functional results at all points except at the time of hospitalization.