Adaptive Proximal Scaphoid Implant: Indications and Long-Term Results

Area of Science:

• Orthopedic Surgery
• Hand and Wrist Surgery
• Musculoskeletal Research

Background:

• Scaphoid nonunion advanced collapse (SNAC) and scapholunate advanced collapse (SLAC) stages I-II often lead to significant wrist dysfunction.
• Arthroplasty of the scaphoid proximal pole (APSI) is a surgical option for managing these conditions.
• Long-term outcomes and indications for APSI require further definition.

Purpose of the Study:

• To define the indications for APSI in treating wrist conditions.
• To evaluate the long-term functional results and radiographic outcomes of APSI.
• To assess the impact of APSI on the natural progression of carpal collapse and osteoarthritis.

Main Methods:

• A monocentric study included patients who underwent APSI between 1994 and 2010.
• Patient assessment involved autoquestionnaires, range of motion, key pinch, and grip strength measurements.
• Radiographs were used to evaluate implant mobility and the evolution of carpal collapse and osteoarthritis.

Main Results:

• Nineteen patients with a mean follow-up of 11 years were analyzed.
• Functional outcomes included mean range of motion at 65-78% of the contralateral side and mean grip strength at 72%.
• After 10 years, 32% of patients developed osteoarthritis, progressing to involve the capitolunate articulation, with no radiolunate involvement.

Conclusions:

• APSI is a viable treatment for SNAC and SLAC I-II, preserving wrist strength and mobility with good functional results.
• APSI does not halt the natural progression towards carpal collapse over 20 years.
• Despite potential long-term carpal collapse, the condition appears clinically well-tolerated in patients treated with APSI.