A Comparison of Outcomes of Treatment with Resection Prosthesis of the Hip in Revision and Oncological Surgery.

Introduction: The introduction of resection prostheses paved the way for the development of limb-sparing surgery in patients with primary or metastatic bone tumours. After some time, the developing possibilities of treatment of extensive bone defects allowed for the use of resection prostheses as an emergency procedure in patients undergoing revision surgery due to hip implant loosening. The aim of this paper is to compare treatment outcomes in patients receiving the Modular Universal Tumour and Revision System (MUTARS) resection prosthesis during arthroplasty performed for different indications: treatment of a tumour metastasis and revision surgery in cases of implant loosening.

Material And Methods: A total of 34 MUTARS femoral resection prostheses were implanted in 34 patients at the Cracow Centre of Rehabilitation and Orthopaedics between December 2008 and January 2016. The procedure was indicated due to the presence of a tumour metastasis (in 13 cases) or due to implant loosening that required revision arthroplasty with a resection prosthesis (in 21 cases). Femoral bone defects were classified according to Paprosky and Katthagen in all operated patients. Clinical assessment was conducted with the modified Harris Hip Score before the surgery and at one year after the procedure. In addition, pain intensity was assessed with a Visual Analogue Scale (VAS).

Results: No statistically significant differences were observed between the groups with respect to the length of the femoral bone resected, perioperative blood loss and the number of packed red blood cell (PRBC) units required. A statistically significant difference was found in duration of the surgery and hospital stay, which were longer in the revision arthroplasty group. No statistically significant differences were observed between the groups in the post-operative HHS scores and pain assessment in the VAS scale. The revision arthroplasty group showed significantly more dislocations (8 vs. 2) and cases of surgical site infection.

Conclusions: 1.The use of the MUTARS modular resection prosthesis allows for fast clinical improvement that meets the patient's expectations both in oncological treatment and in revision arthroplasty. 2. The extent of bone resection, procedure duration and perioperative blood loss associated with the surgical placement of a resection prosthesis are similar in oncological treatment and in revision arthroplasty. 3. The use of a resection prosthesis in revision arthroplasty is associated with a high risk of implant dislocation.