Effects of a Home-Based Physical Rehabilitation Program on Tibial Bone Structure, Density, and Strength After Hip Fracture: A Secondary Analysis of a Randomized Controlled Trial

Weight-bearing physical activity may decrease or prevent bone deterioration after hip fracture. This study investigated the effects of a home-based physical rehabilitation program on tibial bone traits in older hip fracture patients. A population-based clinical sample of men and women operated for hip fracture (mean age 80 years, 78% women) was randomly assigned into an intervention (n = 40) and a standard care control group (n = 41) on average 10 weeks postfracture. The intervention group participated in a 12-month home-based rehabilitation intervention, including evaluation and modification of environmental hazards, guidance for safe walking, nonpharmacological pain management, motivational physical activity counseling, and a progressive, weight-bearing home exercise program comprising strengthening exercises for the lower legs, balance training, functional exercises, and stretching. All participants received standard care. Distal tibia (5% proximal to the distal end plate) compressive bone strength index (BSI; g(2)/cm(4)), total volumetric BMD (vBMD(TOT); mg/cm(3)), and total area (CSA(TOT); mm(2)), as well as midtibia (55%) strength-strain index (SSI; mm(3)), cortical vBMD (vBMD(CO); mg/cm(3)), and ratio of cortical to total area (CSA(CO)/CSA(TOT)) were assessed in both legs by pQCT at baseline and at 3, 6, and 12 months. The intervention had no effect (group x time) on either the distal or midtibial bone traits. At the distal site, BSI of both legs, vBMD(TOT) of the fractured side, and CSA(TOT) of the nonfractured side decreased significantly over time in both groups 0.7% to 3.1% (12 months, p < 0.05). At the midshaft site, CSA(CO)/CSA(TOT) and SSI of both legs, and vBMD(CO) of the fractured leg, decreased significantly over time in both groups 1.1% to 1.9% (12 months, p < 0.05). Trabecular and cortical bone traits of the tibia on the fractured and the nonfractured side deteriorated throughout follow-up. The home-based physical rehabilitation intervention aimed at promoting mobility recovery was unable to prevent bone deterioration in older people after hip fracture. (C) 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.