Long-term follow-up of bilateral hip and knee arthroplasty secondary to ochronotic arthropathy

Abstract

Alkaptonuria is a rare metabolic disorder caused by the deficiency of homogentisic acid oxidase enzyme, which is responsible for eliminating homogentisic acid from the body through the renal system. Excessive accumulation of homogentisic acid leads to ochronosis and ochronotic arthritis. Owing to the rarity of the disease, long-term functional outcomes of joint replacements of the hips and knees in ochronosis arthropathy are unconfirmed, and only a limited number of case reports are available on this. We present a case of a 45-year-old man with ochronosis and advanced osteoarthritis of both the hips and knees. He underwent bilateral hip and knee replacements as staged procedures. At a follow-up of more than 12 years, the man had full mobility with no loosening of implants.

Keywords: Arthroplasty; Follow-up; Long-term; Ochronosis; Osteoarthritis.

Figure 1

Preoperative radiograph images of the hips showing gross loss of joint space suggesting features of osteoarthritis, whereas the last postoperative radiograph images (September 2019) showing the implantation of bilateral hip prosthesis.

Figure 2

Intraoperative images of the hip (left) and one of the knees (right) showing severe ochronotic involvement with blackish discoloration of the joint.

Figure 3

Preoperative radiograph images of the knees suggesting features of severe osteoarthritis, whereas the last postoperative radiograph images (September 2019) showing implantation of bilateral knee prosthesis.