Abstract
Background
Short term results of silastic implant of first MTPJ are successful. However reservations exist regarding long term results. The aim of this study is to evaluate long term outcome of silastic implant prosthesis in treatment of hallus rigidus.
We reviewed 108 feet in 83 patients who were operated on between 1988 and 2003. Mean age at operation = 55(SD 8.1). Mean follow up = 8.31 years (SD 3.3). Patients were assessed using the American Orthopaedic Foot and Ankle Scoring system (AOFAS). Passive and active arc of motion were measured. To assess patients' satisfaction they are asked if they would repeat the procedure and also using a visual analogue scale (VAS) to express their overall satisfaction with the outcome. All the patients had anteroposterior and oblique views. Radiographs were assessed for loosening and osteolysis.
Results
Median AOFAS = 81(IQR = 15). Median VAS = 8(IQR = 3). Median active arc of motion = 35(IQR 18). Passive arc of motion = 46(IQR = 23). No significant difference in results was found in patients with associated hallux valgus (p value = 0.6). There was significant correlation between the AOFAS and VAS (Pearson correlation = 0.58, p value <.0001). No correlation was found between AOFAS, VAS and radiological changes (P value = 0.8 and 0.9 respectively). In 83 feet (76.9%) patients reported “yes” that they would repeat the procedure and in 22(20.4%) feet patients reported “no”. Prosthesis were removed in three feet at three, five and seven years respectively because of persistent pain. Radiologically, 58% showed cyst formation but didn't correlate with functional outcome.
Discussion and Conclusion
This study provides the largest cohort in the literature and the longest follow up. We can conclude that silastic implant arthroplasty is an effective procedure in hallux rigidus management with satisfactory functional outcome and high patient satisfaction.
