Clinical and radiological outcomes of total joint arthroplasty in patients with ochronotic arthropathy.

PURPOSE

Alkaptonuria is a rare metabolic disorder, and only a few case reports of total joint arthroplasty (TJA) for ochronotic arthropathy are described in the literature. We aim to analyse the functional and radiological outcomes of TJA in patients with ochronotic arthropathy.

METHODS

We retrospectively collected the data of twenty-seven TJA in sixteen patients with ochronotic arthropathy from April 2007 to December 2017. We assessed the functional outcome through pre- and post-operative modified Harris hip score (HHS) and knee society score (KSS). The hip radiographs were analysed for migration and radiolucent zones, and the knee radiographs were assessed using knee society roentgenographic evaluation and scoring system.

RESULTS

The mean follow-up was 39.4 months (12-132 months). Two patients died before the final follow-up. There was a statistically significant improvement in mean HHS from 17.8 preoperatively to 78 at the final follow-up (p < 0.001). Similarly, there was a significant improvement in mean KSS, following the surgery, from 27.2 preoperatively to 89.4 (p < 0.001). One patient developed deep infection, and another patient presented with aseptic loosening of the acetabular component after 7 years. In the radiological evaluation at the final follow-up, signs of lysis or loosening were not noted in any of the other patients.

CONCLUSION

End-stage arthritis in ochronotic arthropathy is not uncommon. These patients can have multiple joint involvements, and the need for multiple surgeries should be considered. TJA in ochronotic arthropathy leads to a significant improvement in the functional outcome compared with the preoperative disability.