Greater Trochanter Tip as an Anatomical Reference to Minimize Leg Length Discrepancy following Hip Arthroplasty

The objective of the current study is to introduce a proposed method and evaluate its efficacy using the greater trochanter (GT) tip rather than the lesser trochanter (LT) as an anatomical landmark to reduce leg length discrepancy (LLD) during performance of hip arthroplasty.

Thirty-two patients who underwent hip arthroplasty were divided according to the GT group (n=17) and the LT control group (n=11); four patients were excluded. LLD was determined by assessing the vertical lengths parallel to the line connecting the lower margin of the teardrop to the most prominent part of the LT on a standing anteroposterior pelvic X-ray taken 30 days after the procedure. The mean and median LLD of the two groups were compared. Analysis of planning for femoral stem depth insertion and postoperative results was also performed.

No significant differences in characteristics including age, sex, or body mass index were observed between the two groups. However, the type of arthroplasty differed significantly between groups (P=0.016). The mean postoperative LLD was significantly smaller in the GT group compared with the control group (P=0.004). The results of linear regression of femoral stem depth showed a significant association between intraoperative planning and postoperative measurement (t=2.705, r²=0.672, P=0.016).

Preoperative measurement in determining femoral stem depth insertion using the GT tip as an anatomical reference can effectively minimize LLD in patients who underwent hip arthroplasty.