Comparison between Pin Fixation and Combined Screw Fixation in Proximal Chevron Metatarsal Osteotomy for Hallux Valgus Deformity Correction

Background: Problems associated with hallux valgus deformity correction using Kirschner-wire (K-wire) fixation include pin pull-out and loss of stability. These complications are pronounced in the osteopenic bone, and few reports have focused on pin versus screw fixation. We examined the use of additional screw fixation to avoid these problems. The aim of this study was to compare outcomes of K-wire fixation (KW) and a combined K-wire and screw fixation (KWS). Methods: Two groups with hallux valgus deformity, who were treated with a proximal chevron metatarsal osteotomy (PCMO), were compared based on the fixation method used. The KW group included 117 feet of 98 patients, and the KWS group included 56 feet of 40 patients. Clinically, the preoperative and final follow-up visual analog scale (VAS) pain score, American Orthopedic Foot & Ankle Society (AOFAS) hallux score, and patient satisfaction score were evaluated. Radiographically, hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured. Results: The mean VAS score decreased from 6.3 preoperatively to 1.6 postoperatively in the KW group and from 5.7 preoperatively to 0.5 postoperatively in the KWS group (p < 0.001). The mean AOFAS scores of the KW and KWS groups improved from 59.4 and 58.2, respectively, to 88.9 and 95.3, respectively (p < 0.001). Eighty-five percent in the KW group and 93% in the KWS group were satisfied with surgery. Clinical differences were not significant. The mean HVAs decreased from 34.7 degrees to 9.1 degrees in the KW group and from 38.5 degrees to 9.2 degrees in the KWS group (p < 0.001). The mean IMA decreased from 14.5 degrees (range, 11.8 degrees-17.2 degrees) to 6.4 degrees (range, 2.7 degrees-10.1 degrees) in the KW group and from 18.0 degrees (range, 14.8 degrees-21.2 degrees) to 5.3 degrees (range, 2.5 degrees-8.1 degrees) in the KWS group (p < 0.001). When IMA values at the 3-month postoperative and the final follow-up were compared, the IMA was significantly increased only in the KW group (p < 0.001) and no difference was found in the KWS group (p = 0.280). Conclusions: We found a statistically significant difference in the decrease in IMA between the 2 groups. We recommend the combined pin and screw fixation in PCMO to enhance fixation stability and prevent potential hallux valgus correction loss.