[Clinical comparative study on resection and non-resection of the fifth metatarsal to rheumatoid forefoot deformity]

To explore clinical effect of the fifth metatarsal head excision and non-excision in rheumatoid arthritis (RA) forefoot deformity reconstruction.

Retrospective analysis was performed on 50 patients (76 feet) with moderate to severe forefoot deformity caused by RA treated from May 2015 to January 2019. According to degeneration of the fifth metatarsophalangeal joint,the fifth metatarsal head was retained or excised by wind-like forefoot reconstruction,and divided into the fifth metatarsal head preservation group (preservation group) and the fifth metatarsal head resection group (resection group). Twenty-four female patients in preservation group,aged from 47 to 81 years old with an average of (60.37±8.60) years old;the course of disease ranged from 13 to 22 years with an average of (19.00±3.06) years;body mass index (BMI) ranged from 21 to 28 kg·m^-2 with an average of (23.53±2.47) kg·m^-2;six patients (6 feet) with moderate hallux valgus deformity and 18 patients (30 feet) with severe hallux valgus deformity;treated with the first metatarsophalangeal joint fusion combined with the second th the fourth metatarsophalangeal joint arthroplasty and the fifth metatarsophalangeal joint cleanup. Twenty-six female patients in resection group were female,aged from 30 to 80 years old with an average of (58.53±13.70) years old;the course of disease ranged from 8 to 25 years with an average of (17.94±3.92) years;BMI raged from 20 to 28 kg·m^-2 with an average of (24.60±2.03) kg·m^-2;4 patients (4 feet) with moderate bunion valgus deformity and 22 patients (36 feet) with severe bunion valgus deformity;treated by the first metatarsophalangeal joint fusion combined with the second th the fifth metatarsophalangeal joint resection of the metatarsophalangeal head. Operation time and postoperative complications between two groups were observed,hallux valgus angle (HVA),intermetatarsal angles between the first and the second metatarsals (IMAFS),intermetatarsal angles between the first and fifth metatarsals (IMAFF),Japanese Society for Surgery of Foot (JSSF) score before surgery and at the latest follow-up were compared.

Fifty patients were followed-up from 14 to 46(25.30±8.83) months in resection group and 12 to 48 with an average of (24.30±11.12) months in preservation group,while no significant difference between two groups (P>0.05). There were no significant difference in operation time and postoperative complications between two groups (P>0.05). JSSF scores,HVA,IMAFS and IMAFF in fesection group were improved from (45.09±3.35) points,(38.90±13.67) °,(12.88±1.72) °,(32.50±2.99) ° before operation to (81.60±3.27) points,(15.40±0.90),(9.06±2.27) °,(22.20±1.98) ° at the latest follow-up (P<0.05);preservation group were improved from (47.09±3.96) points,(43.30±12.65) °,(13.99±3.13) °,(33.20±6.14) ° to (83.10±3.66) points,(15.20±1.54) °,(8.99±1.02) °,(24.70±1.88) °,respectively. There were no significant difference in JSSF score,HVA,IMAFS and IMAFF between two groups before operation and the latest follow-up (P>0.05). At the latest follow-up,there were statistically significant differences in pain and deformity in JSSF scores between two groups (P<0.05).

Both rheumatoid anterior foot reconstruction and anterior foot reconstruction fifth metatarsophalangeal joint debridement showed significant improvement in clinical efficacy and imaging results. Compared with rheumatoid prefoot reconstruction,the fifth metatarsophalangeal joint reconstruction for the treatment of moderate and severe deformity of rheumatoid prefoot showed better improvement in pain,but worse improvement in deformity. For the moderate to severe deformity of the forefoot caused by rheumatoid disease,patients with mild to moderate degenerative deformity of the articular surface of the fifth metatarsal phalanges may be considered for use.