Slovenská chirurgia 3/2019
Clinical results of METHA short femoral stem, 5 to 12 years evaluation
Introduction: The current situation in endoprothetics points not only to the ever-increasing number of alloplastic surgeries, but also to a shift to increasingly younger age groups, which implies an increased number of revision operations. This trend is pushing manufacturers and surgeons to develop more stable and durable implants in order to extend the life of prostheses to the limits of physical and biological properties. The concept of shortened stems is based mainly on the idea of saving bone, soft tissues and vascular supply while minimizing blood loss using a miniinvasive event. selecting any of the standard operating approaches. Aim of study: The aim of our study was to evaluate clinical and radiological results after implantation of total hip replacement using a short femoral stem Metha. Methodology: We evaluated patients after implantation of short femoral stem Metha operated in our department between 2007 and 2014. Implant results were assessed by questionnaire, Harris Hip Scores clinical examination, visual analogue scale of hip and thigh pain, and we assessed the rate of revision. We radiologically evaluated signs of osteointegration, release and rate of revision. Results: In the clinical evaluation, the mean Harris score was 42,2 ±9,1 (29-57) preoperatively and 93,1 ±5,1 (60-100) in the last follow-up. The average value of visual analogue scale of hip and thigh pain changed from a preoperative value of 7,51 ±2,1 (5-10) to 0,58 ±1 (0-5). Stress-shielding, therefore bone atrophy in the region of calkar and bone hypertrophy under the tip of the stem, was not recorded in either case. We did not found any evidence of radiolucent hem or cystic lesions suggesting signs of deliberation. At the last inspection, all shafts showed good osteointegration. These results support the concept of implantation of short stems with metaphyseal anchorage, especially in younger patients whose overall survival of alloplasty is shorter than in older patients. There was no revision of the Metha implant. Conclusion: There are no long-term clinical trials using short femoral stems, but published mid-term studies show promising results in terms of primary stability, early osteointegration and absence of thigh pain. Our results confirm that the Metha implant provides an adequate alternative to conventional shafts, with good osteointegration and lower incidence of stress shielding. In the absence of longterm results, it is necessary to continue to monitor and evaluate the results after implantation of Metha short stems.
Keywords: short femoral stem, metaphyseal anchorage, stress shielding, osteointegration, bone and soft tissue conservation
