Influence of leg length inequalities on pelvis and spine in patients with total hip arthroplasty

Abstract

Background Leg length inequalities (LLIs) are a common finding in patients with a total hip arthroplasty (THA). Therefore, we compared the effects of simulated LLIs in patients with total hip arthroplasty (THA) with a matched control group. Research question Do LLIs lead to different effects on the musculoskeletal apparatus of patients with a THA then in a control group? Methods In 99 patients with a THA the effects of simulated LLIs were compared to a matched control group of 101 subjects without a hip arthroplasty. First, we compared methods for LLI quantification (tape measurements, pelvic x- ray and rasterstereography). Second, the effects of simulated LLIs on the spine and pelvis were evaluated in both groups using surface topography. LLIs of 5, 10, 15, 20 and 30 mm were simulated on both sides with a simulation platform. The changes of pelvic position (pelvic obliquity & pelvic torsion) and the effects on spinal posture (surface rotation & lateral deviation) were measured and analysed using a surface topography system. Results Mean LLI measured with a tape was 0.9 mm (SD +/- 14.8). Mean pelvic obliquity measured on x-rays was 1.2 mm (SD +/- 11.6) and with surface topography 0.9 mm (SD +/- 7.9). Simulated LLIs resulted in significant changes of pelvic position and spinal posture in the patient and control group. Interestingly, our study showed that simulated LLIs lead to greater changes in pelvic position (p<0.05) in patients with a THA. Significance This is the first study to demonstrate that LLIs might have a greater impact on the pelvic position of THA patients than in native hips, which could indicate that LLIs do need to be compensated differently in patients with THA than in patients without a THA.

Morphological consistency of bilateral hip joints in adults based on the X-ray and CT data

“…LLD is a common complication of THA, which may cause short-term hip pain and discomfort that result in lameness, compensatory pelvic tilt or scoliosis, and even aseptic loosening of the prosthesis in the long term [ 4 , 11 ]. Previous literature has shown that it is clinically acceptable to have unequal leg length of less than 10 mm in terms of imaging [ 1 ]. In our study, more than 1/4 patients had LLD after bilateral hip replacement, even 18 of them were larger than 10 mm.…”

Robotic Arm–Assisted Total Hip Arthroplasty to Correct Leg Length Discrepancy in a Patient With Spinopelvic Obliquity

“…It is known that differences in limb lengths can introduce spinopelvic obliquity as a compensatory mechanism [14]. Total hip arthroplasty resulting in a limb length discrepancy can invite rotational compensatory changes in the spinopelvic complex [15]. The prolonged consequences of these mechanisms are commonly sacroiliac [16] and back pain [17].…”

Systematic changes of the static upper body posture with a symmetric occlusion condition

“…In order to achieve optimum measurement of the back surface, for each test person six anatomical landmarks (light-reflecting markers of 1 cm diameter) were necessary. The ABW-BodyMapper has already been used successfully in studies to determine representative standard values for young men (18-35 years) [32] and middle-aged men [41][42][43][44][45][46][47][48][49][50] [33] as well as women (21-30 years) [59]. Formula or algorithm used to calculate the evaluation parameters are published by Ohlendorf et al [33].…”

“…The clear benefit to a 2 dimensional photography [46] or video analysis [47,48] is the depth information calculated from the projected lines onto a curvature. With progress in image reconstruction algorithms, surface parameters of the upper body can be calculated [32,34,41,49]. Obviously, it cannot measure below the surface, therefore a quantification of spinal parameters is not possible.…”