Hallux valgus surgery : epidemiological aspects and clinical outcome

Abstract

Hallux valgus is a common condition that accounts for a significant number of visits to foot and ankle specialists. Surgery is the standard treatment but there is insufficient evidence from randomized trials to determine which method of treatment is the most appropriate. Furthermore the prevalence of forefoot and hallux valgus surgery has not been well documented.

We have investigated the prevalence of forefoot surgery in Sweden (Study I) and obtained data for the surgical treatment of hallux valgus in a geographically defined population. We also determined (Study II) the reliability of radiographic measurements, used as criterions for the choice of procedures and surgical failure or success. Moreover, we used a system to evaluate the appearance of the hallux. We tested, in a prospective randomized controlled trial (Study III) the hypothesis that the differences between the surgical procedures would affect the outcome. The quality of life (Study IV) before and after hallux valgus surgery was evaluated. Finally, the plantar pressure distribution and pain after two distal first metatarsal osteotomies were assessed (Study V).

In study I, the investigated population included patients of any age and sex who underwent forefoot surgery in both ambulatory (2000) or inpatient settings (1997- 2000). Epidemiologic data was retrieved from the National Swedish Patient Register (NSPR). Clinical data was extracted from medical records of hallux valgus surgery in the Stockholm region. In studies II, III and IV, 100 prospective randomized cases were included. In study II, radiographs and photographs from 100 patients undergoing hallux valgus surgery were evaluated by two independent observers. In study III, 100 hallux valgus patients were randomized to a Lindgren (n= 50) or a distal chevron osteotomy (n= 50). We employed measures such as the American Orthopaedic Foot and Ankle Society (AOFAS) clinical rating for the hallux, EuroQol (EQ-5D) for health-related quality of life and visual analogue scales (VAS) for pain in addition to radiographic and clinical parameters. In study IV, the measures used were the quality of life (QoL) according to SF-36, a disease specific score (AOFAS), the severity of the deformity, the possibility of wearing the preferred choice of shoes and satisfaction with the treatment. The pre- and postoperative QoL scores were compared with the score in the general population. In study V, twenty-two patients randomly assigned to either a distal chevron or a Lindgren first metatarsal osteotomy were evaluated prospectively with dynamic plantar pressure measurement, quality of life scores, clinical and radiographic measurements.

Study I, provides comprehensive data on the prevalence of forefoot surgery in Sweden. The number of operations in relation to the population was not evenly distributed in the 6 major regions in Sweden. The procedures were more common in urban areas than in rural regions. We also found that in-patient surgery was more common in private clinics than in community hospitals. Study II showed that the intraobserver reliability was higher than the interobserver reliability for the intermetatarsal distance, the appearance of the hallux and the sesamoid positions. Angular measurements were more accurate than linear measurements. Evaluation of appearance was less reliable than the radiographic measurements except for the sesamoid position measurements. In study III, the clinical outcome of the two procedures was similar but patients operated with Lindgren’s osteotomy showed better correction as judged by radiological measurements. Loss of correction was noted in both groups after 3-6 years. Neither osteotomy was recommended for patients with a HVA > 30° and/or an IMA > 15°. Study IV showed that pain affected the quality of life in these patients. Surgery produced a significant improvement. The severity of the deformity did not influence the quality of life; however a free choice of shoe ware and satisfaction with the surgery was associated with a better quality of life. SF-36 is a relevant instrument for evaluating outcome in hallux valgus surgery. Study V demonstrated that both surgical techniques used resulted in significant clinical and radiographic improvement and reduced the level of pain, although the foot pressure recordings demonstrated no biomechanical effect of the treatment.