Comparison of outcomes according to fixation technique following the modified Ludloff osteotomy for hallux valgus in patients with rheumatoid arthritis

BACKGROUND Clinical and radiological outcomes including fixation stability of osteotomy site were compared in rheumatoid arthritis (RA) patients who underwent modified Ludloff osteotomy to correct hallux valgus with osteotomy site fixation using two screws versus those who underwent additional fixation using a plate. METHODS The fixation technique performed with two screws was used to fix the osteotomy sites following modified Ludloff osteotomy in 15 patients (15 feet, Group S), while the augmented plate fixation technique was used in 14 patients (16 feet, Group P). Surgical outcomes were analysed using the American Orthopedic Foot and Ankle Society (AOFAS) scores, and radiologic parameters measured before surgery and during follow-up examinations. To evaluate the stability of each osteotomy site fixation technique, the 1-2 inter-metatarsal angle (IMA) and angle of the altered margin of the lateral cortex (AMLC) were measured immediately and 6 weeks after surgery, and variations in the angles were compared. In addition, bone mineral density (BMD) values were compared between patients with correction loss at the osteotomy site and those with no loss of correction. RESULTS No significant differences between groups were found for total AOFAS scores before surgery and at the final follow-up. However, significant differences were observed in the 1-2 IMA, beginning at 6 weeks postoperatively and continuing through the final follow-up. The 1-2 IMA and angle of AMLC measured immediately after and 6 weeks after surgery showed significantly greater variation in Group S than in Group P. In Group S, patients with correction loss (5 feet) at osteotomy site showed significantly lower BMD values than those with no loss of correction (10 feet). Despite the lower BMD values of patients in Group P than in Group S, a loss of correction did not occur in these patients. CONCLUSIONS Correction loss occurred at the osteotomy site within 6 weeks postoperatively in patients who underwent fixation using only the two-screw fixation technique following modified Ludloff osteotomy; such loss could be reduced using the augmented plate fixation technique even in patients with osteoporosis.