A Review of Symptomatic Leg Length Inequality following Total Hip Arthroplasty

Abstract

Leg length inequality (LLI) following total hip replacement is a complication which features increasingly in the recent literature. The definition of LLI is complicated by lack of consensus regarding radiological measurement, clinical measurement and the incomplete relationship between LLI and associated symptoms. This paper reviews 79 reports relating to LLI post hip replacement, detailing definitions and classification and highlighting patient populations prone to symptomatic LLI. While there is no universal definition of LLI, there is a broad consensus that less than 10 mm of difference on AP view plain radiographs is clinically acceptable. There are few techniques described that consistently produce a postoperative LLI of less than this magnitude. Where postoperative LLI exists, lengthening appears to cause more problems than shortening. In cases of mild LLI, non-surgical management produces adequate outcomes in the majority of cases, with functional LLI cases doing better than those with true LLI. Operative correction is effective in half of cases, even where nerve palsy is present, and remains an important option of last resort. Poor outcomes in patients with LLI may be minimised if individuals at risk are identified and counselled appropriately.

Total Hip Arthroplasty via Lateral Approach in Supine Position

“…However, if this type of stem is not available, a larger stem or ball can be used to maintain the stability of the joint. Under these circumstances, the limb will be longer than the contralateral limb; however, stability is always more important than length.…”

Limb length discrepancy after total hip arthroplasty: a systematic review

“…In the methods described by Williamson and Reckling distance between most inferior point of Ischia and lesser trochanter is measured, whereas in method described by Woolson et al distance between inferior point of acetabular tear drop and lesser trochanter is measured. 14,18 Neither Woolson's nor Williamson's method takes account of hip flexion or abduction deformity at the time of the x-ray (which tends to reduce the measured LLD) or any causes of LLD which does not involves the hip. 14 Heaver et al reported that inter ischial line was best pelvic landmark for measurement of LLD, whereas Meermans et al reported teardrop line to be better.…”

“…14,18 Neither Woolson's nor Williamson's method takes account of hip flexion or abduction deformity at the time of the x-ray (which tends to reduce the measured LLD) or any causes of LLD which does not involves the hip. 14 Heaver et al reported that inter ischial line was best pelvic landmark for measurement of LLD, whereas Meermans et al reported teardrop line to be better. 17,19 Meermans et al further reported that centre of femoral head should be taken as femoral reference point instead of lesser trochanter.…”

“…This can be further complicated when using an uncemented femoral stem or in the obese patients. 14 In the patients with short, varus neck of femur and short abductor muscles, abductor are sensitive to stretching and thus result in a tilted hemi-pelvis and apparent lengthening of operated leg. 3 Short stature patients and obesity are other notable risk factors.…”

“…3 Short stature patients and obesity are other notable risk factors. 14 Preoperative template technique <10 mm -20 to+20 Jasty et al 12 Use of Jigs and calipers 5.4 -0.5 to+40…”