SLR - September 2015 - Tamer Younan

Proximal Opening Wedge Osteotomy with Wedge-Plate Fixation Compared with Proximal Chevron Osteotomy for the Treatment of Hallux Valgus

Reference: Glazebrook M, Copithorne P, Boyd G, Daniels T, Lalonde KA, Francis P, Hickey M. J Bone Joint Surg Am. 2014 October 1; 96-A(19):1585-1592.

Scientific Literature Review

Reviewed By: Tamer Younan, DPM, PGY2
Residency: Cedars-Sinai Medical Center, Los Angeles, CA

Podiatric Relevance:
Numerous operative procedures and techniques have been described for the treatment of hallux valgus, which is a very common and potentially painful and debilitating podiatric condition. Proximal metatarsal osteotomies combined with a distal soft tissue procedure and exostectomy are widely used in the treatment of moderate to severe hallux valgus. The authors of this publication aimed to compare the clinical and radiographic outcomes of the proximal opening wedge osteotomy with the use of a custom low-profile wedge plate with the outcomes of the proximal chevron osteotomy for the treatment of hallux valgus.

Methods: This study was a prospective randomized, controlled trial performed at three different centers in Canada. Included patients had persistent, incapacitating symptoms despite non-operative treatment (shoe-wear modification, orthotics, non-steroidal anti-inflammatory medications, and restricted activity) with a hallux valgus (HAV) angle of >20° and an intermetatarsal (IM) angle of >10°. Patients with degenerative arthritis of the first metatarsophalangeal joint, neuropathy, diabetes mellitus, peripheral vascular disease, or previous surgery on the ipsilateral first metatarsal, hallux, or metatarsophalangeal joint were excluded from the study.
       
One cohort underwent a proximal opening wedge osteotomy (n = 39) of the first metatarsal with wedge-plate fixation, and the other cohort underwent a proximal chevron osteotomy (n = 35) fixed with two mini-fragment screws only and no plate. Both cohorts also underwent a distal soft tissue procedure and exostectomy. All three surgeons performed both procedures according to the randomization designation.

Clinical outcome measures consisted of scores from the Short Form-36, the American Orthopedic Foot & Ankle Society (AOFAS) forefoot questionnaire, and the visual analog scale (VAS) for pain, activity, and patient satisfaction. Subjects were assessed prior to surgery and at three, six, and twelve months postoperatively. In addition, the radiographic outcome measures consisted of evaluating the HAV and IM angles, the relative first metatarsal length (% relative to length of second metatarsal) and radiographic union post-surgery.

Results: No significant differences were found for any of the patients’ clinical outcome measurements between the two treatment groups. Furthermore, at one-year follow-up, the proximal opening wedge osteotomy was found to lengthen, and the proximal chevron osteotomy was found to shorten, the first metatarsal. The IM angles improved (decreased) significantly, from 14.8° to 9.1° after a proximal opening wedge osteotomy and from 14.6° to 11.3° after a proximal chevron osteotomy. HAV angles improved significantly, from 33.9° to 19.9° after a proximal opening wedge osteotomy and from 35.2° to 17.7° after a proximal chevron osteotomy. The mean length of the first metatarsal was significantly increased in the proximal opening wedge osteotomy cohort, from 83.8 percent to 86.0 percent. In contrast, the mean length of the first metatarsal was significantly shortened in the proximal chevron osteotomy cohort, from 84.2 percent to 81.6 percent.

Conclusions: Based on their findings, the authors of the publication concluded that both procedures were effective in improving clinical outcomes and scores for pain and activity as well as offering predictably successful results in patients with moderate to severe hallux valgus. In addition, they concluded that the radiographic results in this study were comparable with previously published results as outlined in their publication. The average IM angle correction was significantly greater in the proximal opening wedge osteotomy group, which may have been the result of a combination of the stable fixation and the precision of inserting a larger wedge to provide greater correction.

As the results of the superiority trial indicated equivalence in overall clinical outcomes between each treatment group there was still an apparent lack of commentary on indications for choosing one procedure over the other. Also absent from the study were the implications of performing each procedure in terms of consequences of lengthening or shortening of the first metatarsal as well as addressing tri-planar correction and assessing post-procedure 1st MPJ range of motion. Given the known findings of shortening when performing a proximal chevron osteotomy, comparing this procedure to other proximal procedures which also have potential to shorten the first ray (such as a closing base wedge osteotomy) may be of more utility for practicing podiatrist when deciding what type of procedure to choose. 

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