Abstract
Category:
Bunion; Midfoot/Forefoot
Introduction/Purpose:
Distal 1st metatarsal chevron osteotomy is one of the most frequently performed procedures for treatment of mild to moderate hallux valgus, though the optimal method of fixation remains in question. The use of Kirschner wires (K-wires) is an established technique of temporary internal fixation that offers a simple and cost-effective strategy. Previous studies have reported removal of K-wires ranging from 4-8 weeks following a chevron osteotomy, though even earlier removal may be acceptable and serve to decrease the risk of complications. The purpose of this study was to determine if early removal of K-wires is adequate to maintain correction of a hallux valgus deformity following distal 1st metatarsal chevron osteotomy.
Methods:
We conducted a retrospective review of patients who had their 1st metatarsal K-wire removed at their first (2week) postoperative visit after undergoing primary chevron osteotomy for treatment of a hallux valgus deformity with a single foot and ankle fellowship-trained orthopaedic surgeon from 2010-2018. Exclusion criteria consisted of revision osteotomies, K-wire removal >=21 days postoperatively, concomitant midfoot or hindfoot procedures, and lack of preoperative or at least 3-month postoperative radiographs. Preoperative, 6-week, 3-month, and longer-term intermetatarsal angles (IMA) were measured on weightbearing anteroposterior (AP) radiographs by an individual blinded to and not involved in the care of the patients. The pre- and postoperative tibial sesamoid position according to the Hardy and Clapham classification (grades 1-7) was also recorded on those with longer-term AP radiographs on file. From 2010-2018, 275 patients underwent 295 primary chevron osteotomies by the senior author, with 72 osteotomies (24.4%) excluded, leaving 223 (75.6%) available for analysis.
Results:
Patients had a mean preoperative IMA of 11.4 +- 2.0 degrees. At 6 weeks, 3 months, and longer-term follow-up averaging 24.6 months, patients had mean IMA of 3.8 +- 1.7, 4.6 +- 1.7, and 4.6 +- 2.2 degrees, respectively, all of which were significantly less (P<0.0001) than the mean preoperative IMA. Of those with longer-term follow-up (n=56, 25.1%), the tibial sesamoid position decreased from 4.6 +- 0.8 preoperatively to 2.3 +- 0.7 at 6 weeks, 2.4 +- 0.8 at 3 months, and 2.6 +- 0.9 at final follow-up. All 3 postoperative time points of tibial sesamoid positions were significantly less (P<0.0001) than the mean preoperative position.
Conclusion:
Our findings demonstrate that removal of K-wires less than 3 weeks following a distal 1st metatarsal chevron osteotomy is sufficient to maintain correction of hallux valgus deformity. The loss of correction in this study is in line with previous studies, where K-wires were removed at later postoperative time points. Delayed wire removal has been shown to lead to increased complications, such as pin tract infection and bending or breakage of the K-wire, which can require not only additional office visits but also potential revision procedures. Removing the K-wire in the early postoperative period should be considered effective and safe.
