1. Revision Total Knee Arthroplasty Using Femoral Head Structural Allograft Corey J. Richards, MD, MASc, FRCSC Luke Pugh, MD Donald S. Garbuz, MD, MHSc, FRCSC Nelson V. Greidanus, MD, MPH, FRCSC Bassam A. Masri, MD, FRCSC AORI Classification FHSACohort(N=24)ControlCohort(N=48)1012 2 – Tibia 03 2 – Femur 027 2 – Femur & Tibia 06 3 – Cavitary – Tibia 10 3 – Cavitary – Femur 50 3 – Segmental – Tibia 120 3 – Segmental - Femur 60 Management of Bone Defects FHSA Cohort (N=24) Control Cohort (N=48) Morsellized Allograft 02 A Single FHSA 19- Two FHSA 5- No Metal Augments 214 Isolated Metal Femoral Augments 1427 Isolated Metal Tibial Augments 12 Metal Femoral and Tibial Augments 75 Results Introduction Institutional support from Zimmer, DePuy and Stryker Presented at the 2010 COA Annual Meeting in Edmonton, AB Methods Conclusions 5 validated quality of life outcome scores were used for patient assessment Oxford Hip Score WOMAC Osteoarthritis Index Short Form 12 (SF-12) Hip and Knee Arthroplasty Satisfaction Questionnaire UCLA Activity Score No significant difference in preoperative baseline scores for 16 (67%) study cohort patients and 25 (52%) control cohort patients Quality of life mean scores were analyzed with a paired t-test Chi-squared test was used for testing significance of proportions, such as Charnley Classification and preoperative diagnosis Cross-sectional, cohort comparison Two cohorts generated from a database consisting of all patients who had undergone revision TKR at our center between January 2000 and August 2005 Minimum 2 year follow-up Study cohort Patients who underwent revision TKR using FHSA for AORI type 3 defect of distal femur, proximal tibia, or both Control cohort Patients who underwent revision TKR with AORI type 1 or 2 defects Exclusion criteria for control group: Infection Inadequate follow-up (< 2 years) Isolated polyethylene liner exchange AORI type 3 defect treated with structural allograft other than FHSA or with tumor prosthesis 24 patients in study cohort (25 eligible with 1 deceased) 48 patients in control cohort Both groups statistically similar in mean age, gender, body mass index (BMI), and Charnley class Preoperative diagnosis also not statistically different with aseptic loosening predominating Intra-operative goal of revision total knee replacement (TKR) is to reconstruct bony defects to restore the anatomic joint line in order to ensure: properly tensioned collateral ligaments balanced flexion and extension gaps correct patellar height Long-term goal is a well-fixed, stable knee joint that improves the patient’s functional status and quality of life Achieving these goals in the setting of massive femoral and/or tibial bone loss continues to be a challenge during revision TKR FHSA superior to revision without allograft WOMAC, Oxford, Satisfaction (p<.05) Despite more severe defects Possibly due to improved interdigitation of cement in the allograft FHSA has the potential for longer survivorship as shown by Hockman et al. To evaluate the clinical outcomes of patients undergoing revision TKR with AORI type 3 defects managed with a FHSA and compare this patient population to a control cohort consisting of aseptic revision TKR patients with AORI type 1 or 2 defects where structural allograft was not used Preoperative Diagnosis FHSACohort(N=24)ControlCohort(N=48) Aseptic Loosening 1931 Polyethylene Wear/Failure 22 Implant Fracture 03 Patellar Failure & Osteolysis 01 Instability210 Arthrofibrosis11 All measured outcomes except for the UCLA Activity Score and the SF-12 Mental Component were significantly higher for the FHSA cohort There was a trend towards a higher score in the UCLA Activity Score Quality of Life Measure FHSA Cohort (N=24) Control Cohort (N=48) p Value WOMAC Function 76610.011 WOMAC Stiffness 77610.002 WOMAC Pain 85660.001 WOMAC Global 79620.004 Oxford Score 80630.001 SF-12 Physical Component 40330.027 SF-12 Mental Component 52480.337 Satisfaction Pain 9368<0.001 Satisfaction Function 9466<0.001 Satisfaction Recreation 8655<0.001 Satisfaction Overall 93710.001 UCLA Activity Score 4.94.00.052 The surgical management of bony defects during revision TKR depends on the size of the defect and whether or not it is contained The Anderson Orthopaedic Research Institute (AORI) classification categorizes bony defects based on preoperative radiographs: F for femur and T for tibia Type 1: Minimal cancellous bone loss Type 2: Substantial cancellous bone loss but rim intact Type 3: Loss of rim and ligamentous support The choice of surgical treatment depends on: size and location of the defect patient’s age and life expectancy surgeon’s preference and experience Options include: Cement, Metal (Ti vs Porous Metals), Morsellized Allograft, Structural Allograft, and Tumor Prosthesis Structural allograft reconstruction is an attractive alternative for younger patients in whom potential bone restoration, for possible future operations is a priority The successful use of FHSA for managing bony defects during revision TKR is well documented Hockman and associates recently published a study demonstrating improved survivorship for patients managed with a structural allograft during their revision TKR compared to those managed without allograft, despite worse preoperative bony defects for the structural allograft group Purpose References 1.Engh, G. A., and Ammeen, D. J.: Use of structural allograft in revision total knee arthroplasty in knees with severe tibial bone loss. J Bone Joint Surg Am, 89(12): 2640-7, 2007. 2.Engh, G. A.; Herzwurm, P. J.; and Parks, N. L.: Treatment of major defects of bone with bulk allografts and stemmed components during total knee arthroplasty. J Bone Joint Surg Am, 79(7): 1030-9, 1997. 3.Hockman, D. E.; Ammeen, D.; and Engh, G. A.: Augments and allografts in revision total knee arthroplasty: usage and outcome using one modular revision prosthesis. J Arthroplasty, 20(1): 35-41, 2005. 4.Scuderi, G. R.; Tria Jr, A. J.: Knee Arthroplasty Handbook Techniques in Total Knee and Revision Arthroplasty. 2006, New York: Springer, p. 119- 132.