Outcomes of Thumb Metacarpophalangeal Joint Arthrodesis Using the XMCP Intramedullary Interlocking Device

Abstract

Purpose: The intramedullary interlocking device for metacarpophalangeal (MCP) joint arthrodesis (XMCP, Extremity Medical, Parsippany, NJ) has been shown to promote union at a precise angle, provide strong fixation without the need for prolonged immobilization, and lower the incidence of hardware irritation and revision surgery. In this study, we evaluated the clinical outcomes of patients undergoing MCP joint arthrodesis with the XMCP system using a retrospective chart review, patient reported outcomes, and radiographic analysis. Methods: A retrospective chart review and phone survey was conducted on 57 patients (58 cases) from a single institution between 2017 and 2022. The primary outcome was patient satisfaction, including pre- and postoperative Numeric Rating Scale (NRS) pain scores, Disabilities of Arm Shoulder and Hand (QuickDASH) outcomes, perceived grip strength, and willingness to undergo the procedure again. Secondary outcomes included the need for revision procedures, successful fusion of arthrodesis, and postoperative complications. Results: Of the 57 patients who underwent MCP joint arthrodesis of the thumb using the XMCP fusion device, a total of 43 (75%) completed the phone survey. The average age of patients was 67 years with an average clinical follow-up of 9 months (range 1–65 months). Patients who participated in the phone survey questionnaire had an average QuickDASH score of 24.7 ± 20.5. Average perceived NRS scores were 6.2 ± 3.5 and 1.2 ± 2.1 before and after surgery, respectively. Average perceived grip strength of patients was 3 ± 1.3 out of 5. When evaluating for concurrent procedures, there was no statistically significant difference in pre- or postoperative NRS scores. In total, 38 (88%) patients were satisfied with the procedure, and 39 (91%) patients would undergo the procedure again. Conclusion: Metacarpophalangeal joint arthrodesis of the thumb with the intramedullary fusion device is reproducible, allows for immediate use without immobilization, has a low number of complications, and provides improved function and pain relief. Level of Evidence: Therapeutic III.

Keywords

• Arthrodesis
• Fusion
• Intramedullary
• Metacarpophalangeal
• Thumb