Conversion arthrodesis for failed first metatarsophalangeal joint hemiarthroplasty

Area of Science:

• Orthopedic surgery
• Foot and ankle reconstruction
• Joint replacement revision

Background:

• Arthrodesis is the standard surgical treatment for first metatarsophalangeal (MTP) joint arthritis.
• First MTP joint hemiarthroplasty demonstrates inferior clinical results and higher revision rates.
• Failed hemiarthroplasty necessitates salvage procedures to restore function and alleviate pain.

Purpose of the Study:

• To evaluate the clinical outcomes of converting failed first MTP joint hemiarthroplasty to arthrodesis.
• To assess the efficacy of salvage surgery in improving pain and function.
• To compare the results of revision arthrodesis with primary arthrodesis outcomes.

Main Methods:

• Retrospective review of 21 patients undergoing conversion of first MTP joint hemiarthroplasty to arthrodesis.
• Preoperative and postoperative assessment using Visual Analog Pain (VAP) scale, AOFAS Hallux Metatarsophalangeal Interphalangeal (AOFAS-HMI) score, and Foot and Ankle Ability Measure (FAAM).
• Analysis of bone grafting techniques, including local autologous and tricortical iliac crest grafts.

Main Results:

• Successful fusion achieved in all 18 patients with available follow-up (mean 4.3 years).
• Significant reduction in average VAP score from 7.8 to 0.75.
• Mean AOFAS-HMI score improved from 36.2 to 85.3; FAAM ADL/sports scores averaged 97.3/91.3.
• Bone grafting was necessary in 18 cases, with 6 requiring structural grafts for extensive bone loss.

Conclusions:

• Conversion of failed hallux hemiarthroplasty to arthrodesis is a successful salvage procedure.
• Outcomes are comparable to primary arthrodesis, particularly with regional bone graft use for smaller defects.
• Fusion time may be prolonged compared to primary arthrodesis, and structural grafting may be required.