Objectives: Advances in drug therapy for rheumatoid arthritis (RA) have been encouraging us to preserve the metatarsopharangeal (MTP) joint in correction of forefoot deformities, and original metatarsal shortening offset osteotomy was recommended as one of the conventional surgical options for forefoot deformities in RA cases. The objective of this study was to evaluate short- to mid-term outcomes of modified metatarsal shortening offset osteotomy.
Methods: A retrospective observational study was completed for 80 RA cases (mean follow-up period: 3.2 years) who underwent modified metatarsal shortening offset osteotomy. Both lesser toe scales and RA foot ankle scales were administered using the Japanese Society for Surgery of the Foot (JSSF) standard rating system, and a postoperative self-administered foot evaluation questionnaire (SAFE-Q) at final follow-up was also checked to evaluate clinical outcomes.
Results: This procedure significantly improved clinical scores of both the JSSF [lesser toes and RA foot and ankle] scales. Of 80 feet, 24 (30%) showed recurrence of MTP joint subluxation/dislocation. Furthermore, the feet in the recurrence group showed significant varus hindfoot. On the other hand, valgus foot in the recurrence group more frequently included midfoot bony ankyloses. All of the affected feet showed the limitation of MTP joints (<70°) after surgery.
Conclusions: Modified metatarsal shortening offset osteotomy was recommended for RA forefoot disorders as one of the joint preservation surgeries in short- to mid-term follow-up. However, some modifications to avoid limitation of ROM in the MTP joint are required. It must be borne in mind that varus hindfoot and/or bony ankyloses in the mid-hindfoot can cause recurrence of dorsal dislocation/subluxation of the lesser toe MTP joint.
Keywords: Forefoot deformity; hindfoot deformity; metatarsal shortening offset osteotomy; rheumatoid arthritis.