RETROSPECTIVE FOLLOW-UP OF 50 ANKLE FRACTURE PATIENTS TREATED WITH A BIODEGRADABLE PLATING SYSTEM

Abstract

Introduction: Conventional metal ankle plates often require secondary removal due to problems such as discomfort or pain. Biodegradable ankle plates and screws have been developed to avoid the need for hardware removal. However, only limited clinical data exists with these new devices. The aim of this study was to retrospectively followup ankle fracture patients treated with biodegradable ankle plates and screws at the Seinäjoki Central Hospital (Finland), and to evaluate clinical outcome and occurrence of postoperative complications in these patients.

Materials and Methods: After ethical committee approval, 57 ankle fracture patients treated with the biodegradable ankle plates and screws (Inion OTPS™, Inion Oy, Tampere, Finland) at the Seinäjoki Central Hospital between March 2004 and September 2006 were invited for a follow-up visit at a private outpatient clinic. Totally 50 patients participated (21 female, 29 male) in the study. There were 36 lateral malleolar fractures (2 with syndesmosis rupture) and 14 bimalleolar fractures (3 with syndesmosis rupture). The average age of the patients was 45 years (SD ± 14, range 18–65) and average weight was 80 kg (SD ± 18, range 45–150). Postoperatively, a cast was applied for 6 weeks. The patients were instructed as follows: First no weight bearing for 2 weeks, then half body weight bearing for 2 weeks, and thereafter gradually towards full weight bearing (with pain restriction). The follow-up included review of each patient’s medical records, evaluation of radiographs (preoperative, postoperative, and the ones taken at the follow-up visit) and fracture reduction classification according to Cedell (anatomic, good, poor), and functional scoring according to Olerud and Molander (0–100). All complications were recorded. In addition, duration of return to work and normal daily activities were asked from each patient.

Results: Average follow-up time was 17 months (SD ± 6.2, range 7–36). No perioperative complications occurred. All fractures healed. Fracture alignment was classified as anatomic in 49 patients and good in 1 case. Average Olerud and Molander ankle score was 86 (SD ± 20, range 15–100). Average duration of return to work was 2.8 months (SD ± 1.3, range 1.5–6), and average duration of return to normal daily activities 3.1 months (SD ± 1.3, range 1.5–6). Postoperative complications: 1 delayed wound healing, 3 cases of deep venous thrombosis, and 4 soft tissue reactions.

Discussion and Conclusions: According to the results of this retrospective study, biodegradable ankle plates and screws provide comparable fracture healing and functional results as those previously reported after use of conventional metal fixation (Lehtonen et al. 2003). Also postoperative complications and their occurrence rates are similar to those seen with metal.