The present study indicates that a modified chevron osteotomy can improve all outcome assessments (e.g. VAS score, AOFAS score, HVA and IMA) in patients with HV and that these improvements can persist for at least five years postoperatively.
Risk factors for HV include gender, connective tissue disorders, pes planus and hypermobility of the first ray(14). A higher prevalence of HV is seen in women, which may indicate that the habit of wearing constricting shoes is an additional risk factor(7). Of the 20 patients with symptomatic HV enrolled in this study, only 2 were men, i.e. the gender ratio was 9:1; this is consistent with previous studies(15). Dysfunction of the first MTP joint, pain and transfer metatarsalgia are the main symptoms of HV. Irritation of the dorsal cutaneous nerve and inflammation of the bursa over the medial eminence contribute to the development of pain(16).
Chevron osteotomy is usually used in patients with mild or moderate HV. However, the traditional chevron osteotomy was associated with complications such as malunion, delayed healing, necrosis of the metatarsal head and shortening of the first metatarsal(7); modifications have therefore been made to the technical part of this surgical procedure to allow early rehabilitation and weight bearing (17). In this study, 27 feet in 20 patients with HV were corrected by modified chevron osteotomy. This surgery achieved good stability. There was no recurrence of HV in the present study during the five postoperative years and no complications, such as transfer metatarsalgia, stiffness of first MTP joint or necrosis of part or all of the metatarsal head; this demonstrates that this technique is safe. In a previous study, Deenik et al. reported a recurrence rate for HV of 7% after distal chevron osteotomy(18). Additionally, the results of Seo’s study indicate a 9% recurrence rate after distal chevron osteotomy in patients with HV aged 60 years or older(11). Comparison between our study and these two previous studies may suggest the conclusion that the modified chevron osteotomy we employed had improved stability over the traditional chevron osteotomy; this conclusion is supported by other studies(7, 19). Verdu-Roman et al. found that a modified chevron osteotomy mitigated the shortcomings of the traditional chevron osteotomy(19). The modified procedure was able to alter foot biomechanics to reduce pain and improve foot activity(19).
The AOFAS score is widely used to evaluate pain, function and alignment (20). In the present study, the AOFAS score improved from 54.40 (± 4.58) preoperatively to 94.30 (± 2.15) six weeks postoperatively and 96.95 (± 1.54) five years postoperatively; i.e. the AOFAS score was significantly improved postoperatively. These improvements indicate that modified chevron osteotomy for HV increased patients’ quality of life (QoL)(21). A recently published study including 591 cases showed that HV corrective surgery significantly improved the QoL of patients after a follow up of two years(22). Our study confirms this result. More importantly, our study employed a much longer follow-up period, indicating that patients’ long-term QoL may be improved by HV surgery. The evaluation of VAS scores in this study further confirms this conclusion.
Radiological evaluation was also performed in this study. As expected, the HVA and IMA were significantly improved after surgery. These improvements persisted at the five-year follow up. A study conducted by Giotis et al. enrolled female athletes who had undergone modified chevron osteotomy(7). At two-year postoperative follow up, the mean HVA and IMA were significantly decreased(7). Vasso et al. conducted a study in which 184 consecutive patients with symptomatic HV who had undergone modified chevron osteotomy were enrolled(23). At 24–56-month follow up, the mean HVA had significantly decreased, from 34.1° preoperatively to 6.2° postoperatively, and the mean IMA had improved from 18.5° preoperatively to 4.1° postoperatively(23). In the present study, the mean HVA and IMA decreased from 32.7° and 16.0° preoperatively to 5.2° and 4.4° five years postoperatively, indicating an excellent clinical outcome for the modified chevron osteotomy.
The present study has several limitations. First, it is a retrospective study with a very small sample size, and all patients were from a single centre. This could cause selection bias. Second, this study did not involve a control group. Third, limited assessments were used to evaluate clinical efficacy (VAS score, AOFAS score, HVA and IMA). Other indicators, such as first metatarsal bone shortening value and sesamoid grade(11) should also be used. Furthermore, the computed tomography of the patients with HV was not routinely examined. Finally, it is not clear from this study whether a modified chevron osteotomy could mitigate the complications caused by the traditional chevron osteotomy. A further study with a larger sample size on this topic should therefore be conducted.