Low-back pain in transfemoral amputees: is there a correlation with static or dynamic leg-length discrepancy?

Abstract

Low-back pain (LBP) is an important cause of secondary disability in transfemoral amputees (TFA). The correction of leg-length discrepancy (LLD) is a common clinical approach to the treatment of LBP in this population. The aim of our study is to assess the relationship of static and dynamic LLD and LBP in a sample TFA population. Nine TFA with LBP and eight TFA without LBP were studied. Static leg length was measured with subjects standing in a self-selected comfortable position. Dynamic leg length was measured during the single-limb support and double-limb support phases of the gait cycle. There were no statistically significant differences between the pain and no pain groups in terms of static LLD (P = 1.0; 95% confidence interval, -6.8 to 6.6 mm); dynamic LLD during single-limb support (P = 0.3; 95% confidence interval, -27.3 to 7.3 mm); dynamic LLD during double-limb support with either the prosthetic limb leading (P = 0.3; 95% confidence interval, -4.0 to 12.2 mm) or the intact foot leading (P = 0.8, 95% confidence interval, -6.4 to 7.8 mm). This study calls into question whether LLD plays a significant role in persistence of LBP in TFA. Further study of the effects of LLD and its possible relationship to causation of LBP in amputees is needed.