1. Outcome Following Pelvic Sarcoma Resection Reconstructed With Saddle Prosthesis Outcome Following Pelvic Sarcoma Resection Reconstructed With Saddle Prosthesis F.Aljassir MD, FRSCC. G.Beadel MB ChB. R.Turcotte MD, FRSCC. A.Griffin BSc. R.S.Bell MD, FRSCC. J.S.Wunder MD, FRSCC. M.H.Isler MD, FRSCC.

2. Introduction. Pelvic sarcomas remain a difficult problem. Classically, hemipelvectomy was the primary means of surgical intervention. With the advent of aggressive chemotherapy, better imaging studies and more advanced surgical techniques, limb-sparing resections have been increasingly used.

3. Techniques of surgical reconstruction include: 1- Ischiofemoral arthrodesis or pseudoarthrosis. 2-Iliofemoral arthrodesis or pseudoarthrosis. 3-Massive allograft or autoclaved autograft with hip arthroplasty. 4-Flail extremity. 5-Custom made metallic prostheses. 6-Saddle prosthesis.

4. The saddle is free to rotate on the body component. The entire prosthesis can abduct, adduct, flex, and extend through the saddle and iliac “articulation”. 1-stem1-stem 2-body 3-Saddle

5. In the literatures there are few clinical studies of the saddle prosthesis 1-Nieder et al ( seven:ISOLS, 313, 1993]. - 72 patients (failed of hip arthroplasty). -1 excellent, 14 good, 36 fair, and 21 poor. -Infection in 15 patients lead to poor results. 2-Aboulafia et al : ( Clin Orthop 314:203-213,1995). -17 patients, -mean follow up of (33 mon). -Favorable results: (excellent in 10, good in 2, fair in 1, and poor in 4.

6. 3- Windhager et al ( Clinical ortho (1996) 331:265-276. ) -22 patients (6 had saddle prosthesis) -Custom-made pelvic had better functional results. -Eccentric new hip centre { limited motion}. 4-Renard et al (Arch Orthop Trauma Surg(2000) 120:188-194) -15 patients. -Satisfactory results in short term follow up. 5-Cottias et al (Journal of surgical oncology 2001;78:90-100.) -17 patients, with mean follow up of 42 months -early pain free weight bearing, -minimal limb shortening -functional results remained fair in most patients.

7. Objectives: To evaluate the outcome after resection of pelvic sarcoma and reconstruction with a saddle prosthesis.

8. Material & Methods. Retrospective study, 27 patients (1991 to 2001). (Maisonneuve- Rosemont Hospital (Montreal) and Mt Sinai Hospital (Toronto). Functional outcome was assessed with MSTS 1987 & 1993 and the Toronto Extremity Salvage Score (TESS). Oncological outcome parameters and complications were recorded.

9. Patients Demographic Gender: 18 male (67%) / 9 female (33%). Age: ( 24 to 75 years ), mean (SD) (53 (16)). Follow up: ( 12 to 120 months), mean (45 months). Operative time: ( 300 to 900 minutes ), mean (SD) ( 600 (98 )). Blood transfusions: from 4 to18 units, mean (SD) (10 (6)).

10. ChSA OSA EHE mGCT EWSA MFH

12. Enneking WF. The anatomic considerations in tumor surgery: pelvis. In: Enneking WF, editor. Musculoskeletal Tumor Surgery, Vol. 2. New York: Churchill Livingstone.1983: 483–529. TYPE I (ilium) TYPE II (periacetabular) TYPE III (pubis) Musculoskeletal Cancer Surgery(2001). Martin Malawar Musculoskeletal Cancer Surgery(2001). Martin Malawar

13. (Enneking WF, Spanier SS, Goodman MA. Asystem for the surgical staging of musculoskeletal sarcoma: Clinical Orthop. 1980 Nov- Dec;(153): 106-20).

14. No radiation therapy given to any patient

15. Complications. Infection in 10 (37%) 4 were superficial and 6 (22%) were deep. Heterotropic ossification in 10 (37%). One year post op. post op.

16. Complications. Dislocations in 6 (22.2%). Fractures in 6 (22.2%) Nerve Injuries in 5 (18.5%). Others (2 dissociations, 3 DVT, and one MI).

17. Vertical migration 1 1 2 2 4 4 3 3 2 2

19. Oncological Outcome. DCDDCD At mean f/u (45 months). AWOD AWD

20. Oncological Outcome. At mean f/u (45 months).

21. Oncological Outcome. Local recurrence in our study : 6/27 (22.2%) 4/6 (67%) had positive resectional margins. Survival rate is (60%) At mean f/u (45 months).

22. Functional Outcomes. *is similar to other study : 1- mean =17, ( 11to 23). { functional evaluation of 17 Saddle) Cottias et al Journal of surgical oncology 2001; 78:90-100. 2-Mean=17.6, (13 to 26). (endoprosthetic pelvic replacement) Bruns et al (Arch Orthop Trauma Surg(1997)116:27-31). *And lower compare to prox - imal femoral replacement : Mean =23.2 (13 to 33) Ogilivie et al clinical orthopedic and related research 2004;426:44-48 Mean (15)

23. Functional Outcomes. Custom made prosthetic reconstruction: mean( 70%) Abudu et al ( JBJS Br. 1997;79- B:773-9). Endoprosthetic pelvic replacement, (51%). Bruns et al (Arch Orthop Trauma Surg(1997)116:27-31). Proximal femoral replacement: Mean=67.7% (40-93%) Ogilivie et al clinical orthopedic and related research 2004;426:44-48 Mean (51%)

24. Functional Outcomes. TESS of limb sparing for lower limb sarcoma (distal thigh): mean (85%) Davis et al, Arch Phys Med Rehabbil. 1999 jun ;80960:615-8. For proximal femoral replacement: Mean = 76%, (40-98) Ogilivie et al clinical orthopedic and related research 2004;426:44- 48 Mean = 58%, (39-95) { functional evaluation of 17 Saddle) Cottias et al (Journal of surgical oncology 2001; 78:90-100). Mean (64%)

25. Functional Outcome Work Status: *Full time 5 patients (18.5%). *Early retirement 5 (18.5%). *Disabled 6 (22.2%). *Deceased 11(40.6%). Gait aids: L.L.D: range between 1 and 6 cm, with a mean of 3cm. L.L.D: range between 1 and 6 cm, with a mean of 3cm. A cane in 8 patients (30%). A cane in 8 patients (30%). Crutches in 5 (18.5%). Crutches in 5 (18.5%). Walker in 3 patients (11.1%). Walker in 3 patients (11.1%). Shoe lift in 5 patients. Shoe lift in 5 patients. A.F.O in 3 patients. A.F.O in 3 patients.

26. Discussion. In pelvic sarcoma goals are to cure the patient and to preserve the best function and quality of life. Treatment of pelvic sarcoma remains difficult. Limited data exists to compare functional outcome. The most common complications are infection and heterotopic ossification.

27. Conclusion. Like with other implants, the oncological and functional outcome in limb salvage procedures using a saddle prosthesis remain difficult to predict, and is associated with significant risk of morbidity and complications. However, the functional results appear to confer an advantage compared to the expected disability following hemipelvectomy.