Early Radiological Outcome of Minimally Invasive Bunion Correction Using a Guided Trajectory System

Category: Bunion; Other Introduction/Purpose: Hallux Valgus correction with Minimally Invasive Surgery (MIS) is a popular procedure due to its potential advantages such as shorter operative time and quicker recovery than open surgery. Third-generation Minimally Invasive Chevron Akin (MICA) osteotomy has shown excellent clinical and radiological outcomes. The optimal fixation criteria are 3-point fixation (medial cortex, lateral cortex, and the lateral half of the 1st metatarsal head) for the proximal screws and 2-point fixation (medial cortex and central position in the 1st metatarsal head) for the distal one. To address the steep learning curve of the free hand technique, we describe a new guided trajectory system for third-generation MICA to increase precision and reduce the risk of suboptimal K-wire or screw placement. Early radiological outcomes and complications were reported. Methods: From April 2022 to January 2023, 13 consecutive MICAs were performed on 11 female patients (bilateral in 2 patients) with an average age of 61 by a single fellowship-trained foot and ankle orthopaedic surgeon who developed the device. These were the 13 first cases performed with the new device. Preoperative and postoperative intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular angle (DMAA) and tibial sesamoid position (TSP) were measured in all patients using weight-bearing radiographs. Also evaluated in the postoperative radiographs were the number of cortical purchase of the screws and their position in the metatarsal head. Additionally, any difficulties or intraoperative complications and operative time were reported. All parameters were analysed with the one-tailed non-parametric Wilcoxon test. Results: All the radiographic parameters improved significantly. The median IMA improved from 14.5 degrees (interquartile range [IQR]: 11.5-16) to 5 degrees (IQR: 4.0-6.0) (p < 0.005). The median HVA also decreased from 27.5 degrees (IQR: 25.3-34.5) to 7.0 degrees (IQR: 4.0-8.5) (p < 0.005). The median DMAA fell from 15.5 degrees (IQR: 13.3-19.3) to 6.0 degrees (IQR: 6.0-8.0) (p < 0.005). The median TSP was 2 (IQR: 2-3) pre-operatively and 0 (IQR : 0-1) (p < 0.005) post-operatively. All the proximal screws for Chevron osteotomy had 3-point fixation and the distal anti-rotation screws had 2-point fixation No intraoperative complications were reported. The mean operative time was 52 (SD:10,4) minutes. Conclusion: Our study demonstrates the successful use of a guided trajectory system for minimally invasive bunion correction with optimal screw placement, good early radiological outcomes, and without extensive operating time. The absence of intraoperative complications or difficulties further confirms the efficacy of this system. Our findings suggest that the use of a guided trajectory system can potentially improve the consistency and success of third-generation MICA procedures. These results emphasize the benefits of incorporating guided trajectory systems in bunion correction surgeries and their potential to improve patient outcomes

Significant Early Loss of Correction in Modified Lapidus Compared to Original Lapidus for Hallux Valgus

Category: Bunion; Other Introduction/Purpose: The Lapidus procedure (first tarsometatarsal joint (TMT1) fusion) is an established treatment for correcting hallux valgus with 1st ray hypermobility. The original Lapidus (OL) technique involves fusing the TMT1 joint and first metatarsal base to the second, while the modified Lapidus (ML) technique involves fusing only the TMT1 joint. The purpose of this study was to investigate whether the ML procedure results in an early loss of correction. Methods: This retrospective study analyzed the outcomes of 45 feet in 40 patients with hallux valgus who underwent either the ML (21 feet) or OL (24 feet) procedure between 2014 and 2022 at a single center. All fixations were performed with 3.5 cortical screws, except for 9 cases that were fixed with a plantar locking plate. Differences in the immediate postoperative (6 weeks) and postoperative (6 months) intermetatarsal angle (IMA) and hallux valgus angle (HVA) were analyzed using Mann-Whitney tests, and complications were reported. Results: The mean preoperative IMA and HVA for the OL were 15.8° ± 3.5° and 36.4° ± 9.5°, respectively, and 14.5° ± 2.3° and 33.0° ± 7.0° for the ML. The immediate postoperative IMA and HVA were similar for both procedures (7.2° ± 2.0° and 7.7° ± 4.3° for OL, 7.3° ± 2.1° and 8.5° ± 5.5° for ML). Although from 6 weeks to 6 months postoperatively, the loss of correction of the HVA did not differ between both procedures (4.2° for OL, 5,6° for ML), the IMA loss of correction was significantly higher in the ML (1.1° ± 1.4° vs 0.5° ± 1.1°) (p < 0.05). One case of delayed union was reported in the OL group, but it did not require revision. Conclusion: The study results suggest that the ML procedure does not provide the same stability as the OL procedure in the early postoperative period, as there was a significantly greater early loss of correction of the IMA at 6 months postoperatively in the ML group compared to the OL group. Although there were no differences in the loss of correction of the HVA angle (HVA), an observed loss of 5 degrees remains a concern. Further studies are necessary to better understand the indications of the modified and original procedures