Abstract
Aim
The saddle prosthesis was originally developed for reconstruction of large acetabular defects in hip revision arthroplasty. Later on the saddle prosthesis was also used for hip reconstruction after resection of peri-acetabular tumours. In case of patient survival a long-term good hip function is required of the saddle prosthesis. The goal of this study is the measurement of long-term clinical results of saddle prosthesis after reconstruction of peri-acetabular tumours.
Method
Between 1987 and 2003 a total of 17 patients were treated in the Leiden University Medical Center with saddle prosthesis after resection of peri-acetabular tumours (12 chondrosarcoma, 3 osteosarcoma, 1 malignant fibrous histiocytoma, 1 metastasis). 11 of the 17 patients died, the mean survival was 37 months (range 2-59 months), and 6 patients were still alive (follow-up 12.1 year, range 8.3–16.8 year). The outcome was measured with the SF-36 questionnaire, the Toronto Extrimity Salvage Score (TESS) and the Musculo Skeletal Tumour Society (MSTS) score. In 1 patient the saddle prosthesis was removed already after 3 months because of luxation and infection.
Results
In 13 of the 17 patients the use of walking devices was known: 54% required two crutches, 38% one crutch, and 8% no walking aids. The mean hip flexion was 60 degrees (range 40-100 degrees). Local complications were seen in 14 of the 17 patients: 9 wound infections, 7 luxations, and 2 leg length discrepancies requiring additional surgery. In the 5 surviving patients the MSTS score at long-term follow up was 47%, the mean TESS score was 53%, the mean composite SF-36 physical and mental scores were 43.92 and 50.64 respectively.
Conclusion
Reconstruction with saddle prosthesis after peri-acetabular tumour surgery has a high risk of complications, and poor long term functional outcome with limited flexion of the hip.