Arthroplasty in the
spondyloarthropathy (SPOND) of
alkaptonuria (AKU) in incompletely characterised. The aim was to improve the understanding of
arthroplasty in AKU through a study of patients attending the National
Alkaptonuria Centre (NAC). Eighty-seven patients attended the NAC between 2007 and 2020. Seven only attended once. Fifty-seven attended more than once and received
nitisinone 2 mg daily. Twenty-three attended at least twice without receiving
nitisinone. Assessments including questionnaire analysis eliciting details of
arthroplasty and other surgical treatments for SPOND, 18 FPETCT and CT densitometry at the neck of hip and lumbar spine, as well as photographs of the eyes and ears were acquired from patients attending the National
Alkaptonuria Centre (NAC) at baseline when 2 mg
nitisinone was commenced, and yearly thereafter. Photographs were scored to derive
ochronosis scores. Blood and urine samples were collected for chemical analyses. The prevalence of
arthroplasty was 36.8%, similar in males and females, occurring especially in the knees, hips and shoulders. Multiple
arthroplasties were found in 29 patients (33.3%) in this cohort. Incident
arthroplasty was 6.5% in the
nitisinone group and 7.1% in the no-
nitisinone group. Incident
arthroplasty was 11.3% in the group with baseline
arthroplasty and 3.51% in the group without. A strong association of
arthroplasty with SPOND (R = 0.5; P << .0001) and
ochronosis (R = 0.54; P < .0001) was seen.
Nitisinone had no significant effect on incident
arthroplasty.
Arthroplasty due to
ochronosis and SPOND is common in AKU.
Nitisinone decreased
ochronosis but had no effect on
arthroplasty in this cohort.