|Beitragstitel||Clinical and Radiological Outcome of Metatarsophalangeal Hemi-Arthroplasty for the Treatment of Hallux Rigidus|
Driven by the patients request for reliable pain relief while preserving a mobile first metatarsophalangeal joint (MTP-I) several prosthetic designs were developed. Early MTP-I prosthetic designs resulted in high failure rates. The purpose of this study is to examine the function, pain, satisfaction, return to sports, and radiological outcome after MTP-I hemiarthroplasty.
After approval by the Cantonal Ethical Committee we identified 15 patients that underwent MTP-I hemiarthroplasty (Arthrosurface, HemiCAP®) in our institution between January 2011 and February 2016. Two patients were excluded from the study because an additional TMT-I arthrodesis was performed. Patients were invited to participate in an outcome study by questionnaires for subjective/objective outcome, and clinical/radiographic follow-up (FU). Two patients were lost to FU.
11 patients (11 feet; 56 ± 15 years) returned the questionnaires. The mean follow-up was 17.8 ± 14 months. 7/11 patients were satisfied with the postoperative result. The visual analog scale for pain (VAS, 0-10) decreased significantly from 7 ± 2.4 preoperative to 3.7 ± 3.1 postoperative (P=0.042). Four patients were taking pain medication at the last FU. The mean passive range-of-motion (ROM, degrees) of the MTP-I preoperative was 31 ± 10, intraoperative after implantation of the hemiarthroplasty and closing of the joint capsule 93 ± 18, at the 6 weeks FU 28 ± 15, at the 3 months FU 37 ± 16, and at the final FU 37 ± 18 (P=0.26). During the FU period a therapeutic infiltration of the MTP-I was performed in 5 patients, mainly for loss of range of motion. In one patient an additional open adhesiolysis of the MTP-I was performed. The mean American Orthopaedic Foot & Ankle Society (AOFAS) forefoot score increased significantly from 48.9 ± 14.3 preoperative to 71.5 ± 15 points at the last FU (P=0.033). Seven patients were able to perform sport at the same or higher level at the final FU compared to preoperative. In none of the patients radiological loosening of the implant was observed at the final FU. The sagittal and coronal alignment of the first ray was not significantly changed from pre- to postoperative.
Although MTP-1 hemiarthroplasty demonstrates a significant pain reduction at a mean follow-up of 17.8 months the ROM of the MTP-I was not restored to anticipated levels and in half of all patients a therapeutic infiltration had to be performed postoperative.