Three intraoperative methods to determine limb-length discrepancy in THA.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Clinical Research

Background:

• Limb-length discrepancy (LLD) is a frequent challenge in total hip arthroplasty (THA), impacting patient and surgeon satisfaction.
• Optimal intraoperative measurement techniques for LLD and minimizing postoperative discrepancies remain incompletely defined.

Purpose of the Study:

• To prospectively evaluate and compare three distinct intraoperative methods for measuring LLD during THA.
• To determine which method demonstrates the strongest correlation with postoperative radiographic LLD.

Main Methods:

• A prospective, randomized, double-blinded study involving 81 patients undergoing primary or revision THA.
• Intraoperative LLD was measured using three methods: abductor shuck (AS), tranosseous pins with caliper (TP), or patella EKG leads (PL).
• Measurements were compared to postoperative clinical and radiographic LLD assessments, calculating correlation coefficients and absolute differences.

Main Results:

• The abductor shuck (AS) method exhibited the highest correlation with postoperative radiographic LLD (R=0.360, P<.05).
• Tranosseous pins (TP) and patella EKG leads (PL) showed statistically insignificant positive correlations (R=0.275 and R=0.301, respectively).
• Clinical LLD measurements demonstrated poor correlation with radiographic findings, suggesting limited utility.

Conclusions:

• The abductor shuck (AS) method is the most reliable intraoperative technique for predicting postoperative LLD in THA among the evaluated methods.
• While all tested methods showed some positive correlation, AS provides superior accuracy for intraoperative LLD assessment.
• Reliance on clinical measurements for LLD assessment in THA may be unreliable compared to radiographic evaluations.