Arthrodesis versus Arthroplasty of the First Metatarsophalangeal Joint in the Treatment of Hallux Rigidus – A Comparative Study of Appropriately Selected Patients

Objective Historical results of arthroplasty of the first metatarsophalangeal joint (1MTP) are relatively poor; however, improvements in the understanding of the normal foot biomechanics, implant materials and design currently make arthroplasty a reasonable option in appropriately selected patients. The present study aimed to compare the clinical and radiographic results of 1MTP arthrodesis and arthroplasty in the treatment of hallux rigidus and to present a rationale for patient selection for arthroplasty. Methods A total of 36 patients (38 feet) with hallux rigidus submitted to surgery (12 arthrodesis and 26 arthroplasties) were prospectively included in the study. Pain was assessed using the visual analogue scale (VAS) and the functional status was assessed using the American Orthopedic Foot and Ankle Society Hallux Metatarsophalangeal-Interphalangeal (AOFAS-HMI) scale. Complications and radiographic results were also analyzed, and survival rates were calculated for both procedures. Results All of the patients reported significant improvement in pain and functional status after surgery. Patients submitted to arthroplasty had better functional results on the AOFAS-HMI scale (89.7 versus 65.7 points; p < 0.001) and better pain relief (VAS 1.6 versus 3.9 points; p = 0.002) when compared with the group submitted to arthrodesis. There was one case of infection in the arthroplasty group and 2 cases of pseudarthrosis in the arthrodesis group. Conclusion Arthrodesis provides pain relief and satisfactory results but alters the biomechanics of gait. Like arthrodesis, arthroplasty improves pain significantly, being a more physiological alternative to preserve the biomechanics of the foot. While the two surgical methods yielded good clinical results, selected patients submitted to arthroplasty had better clinical scores and lower revision rates.