Spinopelvic alignment does not change after bilateral total hip arthroplasty in patients with bilateral Crowe type-IV developmental dysplasia of the hip.

OBJECTIVE

This prospective study aimed to evaluate the changes in the sagittal alignment after total hip arthroplasty (THA) in patients with hip osteoarthritis (OA) secondary to Crowe type-IV developmental dysplasia of the hip (DDH) and whether THA would contribute to the relief of low-back pain (LBP).

METHODS

A total of 27 patients (2 men and 25 women) with bilateral hip OA secondary to Crowe type-IV DDH were enrolled in this study. Their mean age at the time of surgery was 40,36±12,35. All patients underwent simultaneous, bilateral THA between January 2015 and December 2016. Clinical assessment included Oswestry disability index (ODI) score and Harris hip score (HHS), and pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and pelvic tilt (PT) were measured from radiographs.

RESULTS

Preoperatively, all the patients had hip and low-back pain. Preoperative and final follow-up ODI scores were 48.3 and 3.9 (p=0.000), respectively. HHS changed from 43.54 to 92.68 (p=0.000). PT and PI significantly changed from -20.4°±20.4° to 3.2°±16.7° (p=0.001) and from 26.6°±35.1° to 47.4°±17.9° (p=0.001), respectively. There were no significant differences regarding the SS and LL measurements. Age or limb-length discrepancy was not significantly associated with the spinopelvic alignment measurements.

CONCLUSION

Restoring the function of the hip with THA is shown to improve hip-associated LBP, but the accompanying hyperlordosis does not change. THA in patients with bilateral Crowe type-IV hips relieves hip pain as well as associated LBP. Hyperlordosis of the lumbar vertebra does not change after surgery, but PI and PT changes are observed; this improvement might have a role in the relief of LBP.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.