Correlation of patient-perceived leg length discrepancy with radiographic measurements after total hip arthroplasty

Introduction: Leg length discrepancy (LLD) is a common complication after total hip arthorplasty (THA).One should minimize the occurrence of LLD to avoid patient dissatisfaction. One method to minimize the risk and to radiographically decrease LLDs is to have accurate pre-operative planning. It is uncertain; however, if the resulting radiographic measurements correlate with the patient’s perception of LLD and ultimately, their satisfaction. This uncertainty lies in the various studies worldwide that show dissenting conclusions. The objective of this study is to determine if there is such a correlationbetween the said radiographic measurements with patients’ perception of leg length and secondarily, to determine the impact of the patient-perceived LLD after THA.

Methods:All patients who underwent THA from2009 to 2013 in a tertiary institution were considered. The leg lengths on routine postoperative radiographs were measured according to the techniques of Woolson7 and Clark8. Patients were then asked about their leg length perception and to evaluate their THA on a subjective grading scale.  The interviewer was blinded from the measurements. Correlation of the leg length radiographic measurements with patient perception and satisfaction was measured through Pearson’s correlation coefficient.

Results: (132) patients were studied. On measurements,53% of the legs were longer with a mean LLD of 3.2mm (SD± 2.5),29.5% had shorter measurementswith mean LLD of 4.9mm (SD± 5.5) and 17.5% had equal leg lengths. (66%) perceived equal leg lengths. (58%) were “very satisfiedwith their operation while 41% were “satisfied. Only 1 graded theTHA as satisfactory”. There is no correlation between the radiographic measurements of leg length and patients’ subjective evaluation. Patient satisfaction was also not correlated with LLD (Pearson’s correlation coefficient, P = 0.08).

Conclusion: LLDs are not always perceived accurately as this study shows no correlation between the measured outcomes. Patient satisfaction also did not correlate with LLD. Although LLDs are commonafter THA, careful preoperative planningmay help minimize this problem.Though there is no correlation between the minimized radiographic measurements and the patient’s ultimate perception of satisfaction, it is still worthwhile to ensure good-quality surgery.