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[A male with black cartilage].
David Visser1,2, Jan A N Verhaar1
1Erasmus MC, afd. Orthopedie, Rotterdam.
Nederlands Tijdschrift Voor Geneeskunde
|March 2, 2021
Summary
Alkaptonuria, a metabolic disorder causing homogentisic acid buildup, can lead to early knee cartilage degeneration. This case highlights the characteristic black cartilage observed during knee replacement surgery in affected individuals.
Area of Science:
- Biochemistry
- Orthopedics
- Genetics
Background:
- Osteoarthritis is a common degenerative joint disease.
- Alkaptonuria is a rare inherited metabolic disorder.
Observation:
- A 52-year-old male patient presented with osteoarthritis of the knee.
- During knee replacement surgery, the remaining articular cartilage exhibited a distinct black discoloration.
Findings:
- The observed black cartilage and early degeneration are pathognomonic for alkaptonuria.
- Alkaptonuria is characterized by the accumulation of homogentisic acid due to a deficiency in the enzyme homogentisate 1,2-dioxygenase.
Implications:
- This case underscores the importance of recognizing clinical signs of rare metabolic disorders in orthopedic settings.
- Early diagnosis of alkaptonuria can guide management and potentially mitigate long-term complications affecting cartilage and other tissues.
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