Alkaptonuria with extensive ochronotic degeneration of the Achilles tendon and its surgical treatment: a case report and literature review
, , , , , e | 30 giu 2021
Article Category: Clinical report
Pubblicato online: 30 giu 2021
Pagine: 129 - 136
DOI: https://doi.org/10.2478/abm-2021-0016
Parole chiave
© 2021 Nesrin Mwafi et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Background
Alkaptonuria is a rare genetic metabolic disorder due to deficiency of homogentisate 1,2-dioxygenase (HGD), an enzyme catalyzing the conversion of homogentisate to 4-maleylacetoacetate in the pathway for the catabolism of phenylalanine and tyrosine. HGD deficiency results in accumulation of homogentisic acid and its pigmented polymer. Ochronosis is a bluish-black discoloration due to the deposition of the polymer in collagenous tissues. Extensive ochronotic involvement of the Achilles tendon in alkaptonuria and its surgical treatment is rarely reported.
Case report
A 43-year-old man presented to our clinic in March 2019 with sudden onset of left Achilles tendon pain with no history of prior trauma. Surgical exploration revealed a complete disruption of the tendon at its attachment to the calcaneus. Black pigmentation was extensive and reached the calcaneal tuberosity, extending about 7 cm from the insertion.
Discussion
Achilles reconstruction was performed using flexor hallucis longus tendon transfer. The patient experienced uncomplicated healing with satisfactory functional results.
Conclusion
Orthopedic surgeons should be aware of the progressive nature of alkaptonuria. Extensive degenerative changes of the ruptured tendon should be suspected so that physicians can plan tendon repair and facilitate prompt surgical intervention.