Pyrocarbon interposition arthroplasty for proximal capitate avascular necrosis

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomaterials Science

Background:

• Avascular necrosis of the capitate head is rare, often managed with partial wrist fusion, which can lead to stiffness.
• This study presents an alternative treatment using pyrocarbon interposition arthroplasty.

Purpose of the Study:

• To evaluate the medium-term outcomes of pyrocarbon interposition arthroplasty for avascular necrosis of the capitate head in a young athlete.
• To assess the technique's efficacy in restoring function, range of motion, and enabling return to high-demand activities.

Main Methods:

• A 15-year-old rugby player with capitate avascular necrosis underwent pyrocarbon interposition arthroplasty (PI(2) implant).
• A custom concave socket was created to secure the implant.
• Follow-up included subjective and objective functional assessments.

Main Results:

• The patient experienced rapid pain relief and regained functional range of motion and grip strength within 3 months.
• Return to rugby was achieved at 1 year, with sustained asymptomatic status at 2 years.
• At 3.5 years, the patient had no limitations in heavy manual labor and maintained good wrist function, including dart-thrower's motion.

Conclusions:

• Pyrocarbon interposition arthroplasty provides favorable medium-term results for capitate avascular necrosis, enabling return to demanding activities and preserving functional range of motion.
• While long-term implant survival is uncertain, this technique is a viable option, with midcarpal fusion as a potential salvage procedure.