Operative Korrektur des 1. Strahls am Fuß – Evaluation des verwendeten Implantats und des klinisch-funktionellen Outcomes

Introduction: The treatment of foot disorders has undergone significant changes in recent years. Reconstructive joint sparing procedures have gained popularity. The aim of treatment is a painless foot, which allows physiological function. Modern angular stable anatomically adapted titanium plates and various hardware are available today. The current literature lacks studies concerning patient’s satisfaction after surgical intervention on the first ray of the foot and safety of the used implants. Material and methods: In a retrospective study, patients who had undergone surgery on hallux valgus and / or hallux rigidus with internal fixation (three different titanium implants made by Merete Medical GmbH, Berlin) in the period from 05/2012 to 08/2015 at the University Hospital Marburg were sent a standardised patient questionnaire. The documents were posted off in December 2016 via the hospital post office. On the one hand, subjective satisfaction with the outcome of the operation using the visual analogue scale for the foot and ankle joint (VAS FA) was evaluated. On the other hand, the influence of the hardware with regard to late complications, material conflicts and hardware removal was monitored by means of a specially created questionnaire. The design of this questionnaire was based on the Foot and Ankle Outcome Score and the Foot Function Index. The survey ended at April 30th, 2017. Furthermore all patient records were checked regarding hardware removal rate, causes of implant removal and changes of relevant radiological angles on the loaded a.-p. Xrays. Results: In 104 patients surgery on the first ray of the foot was performed with the selected implants during the study period. 54 patients (11 men, 43 women) could be evaluated more thoroughly after return of the questionnaires. These patients referred to the following surgical procedures and implants: arthrodesis of the first metatarsophalangeal joint (implant: MetaFixTM MTP-plate [n = 7]), arthrodesis of the first metatarso-cuneiforme joint according to a Lapidus procedure (implant: MetaFixTM Plantar BG10-plate [n = 17]), modified Chevron osteotomy [n = 28] and Scarf osteotomy [n = 2] (implant: DuoThreadTMScarf-screw). Hardware removal was performed on a total of ten patients (18.5%). The main reason was pain in 60%, followed by swelling and irritation of soft tissues. Of the 44 patients who did not undergo implant removal at the time of follow-up, 18.2% considered this procedure. One patient without any complications wished to remove the material. Two patients underwent fracture of the compression screw implanted together with the MetaFix Plantar BG10-plate following Lapidus arthrodesis. After hardware removal patients showed significantly lesser pain and higher functional scores in relation to the patients with the implant left (p < 0.05). VAS FA and subjective cosmetic results correlated significantly (p < 0.05). Arthrodesis of the first metatarsophalangeal joint was evaluated best with regard to the cosmetic result. The modified Chevron osteotomy was evaluated with the highest score concerning VAS FA. Discussion: The implant removal rate we have collected is in line with the results in the international literature. Material removal on the first ray of the foot should be individually and thoroughly weighed out for each patient. Our study data demonstrate that patients should be informed preoperatively about the respective implant, its possible influence on the functionality and the probability of further surgery to remove the implant. The examined implants of the company Merete®Medical GmbH (Berlin) are to be regarded as safe.