Assessment of Physical Performance and Early Treatment Outcomes after Implantation of Modular Prostheses of Femoral and Tibial Shaft

BACKGROUND: Tumours of bone diaphyses often require resection followed by bone reconstruction. The use of modular pro-sthe-ses permits early limb loading and rapid improvement in physical performance. The aim of this study was to evaluate the func-tioning of patients and early treatment outcomes after the implantation of modular prostheses. The analysis covered the correlation between the extent of resection, physical performance and the number of perioperative complications. MATERIAL AND METHODS: 10 patients (5 women and 5 men) with diaphyseal tumours who had modular prostheses implanted were treated at the Orthopaedic Oncology Department in Brzozow between 2014 and 2018. The mean age of the patients was 51.1 years (range: 26-63 years). Functional outcomes were assessed using the MSTS and the Karnofsky scoring system. A VAS was used to evaluate pain intensity. the extent of resection was also analysed, considering bone length and tumour weight. RESULTS: The mean tumour weight was 374g (150-700g). The length of the implants varied from 10 to 25 cm. The mean dura-tion of hospitalisation was 16 days (14-19 days). At 3 months following the surgery, the intensity of pain had decreased from a mean of 6.8 points to 4.2 points (a decrease of 26% from the pre-operative baseline). The MSTS showed improvement of functional performance from a mean of 10.8 points (36%) to 22.9 points (76%). The Karnofsky scores demonstrated an increase in physical performance from 47 to 67 points (20 points on average). Superficial infection of the wound developed in 1 patient. CONCLUSIONS: 1. The treatment of diaphyseal tumours with modular prostheses produces good functional outcomes. 2. The extent of the resection and the size of the implant have an effect on the post-operative physical performance of the patients. 3. Pre-operative evaluation of the weight of the tumour may be helpful in predicting the patient's post-operative functional status. 4. Phy-sical perfor-mance is better after the resection of femoral vs tibial tumours.