Abstract
To determine the effect of altering tibial slope on the two-year range of motion (ROM) of patients undergoing condylar total knee replacements (TKR).
A single surgeon performed 74 primary cemented posterior stabilised tri-compartmental TKR’s on 56 patients (19 male, 37 female) with mean age of 67.1 years, height 66.7in., weight 187.4 lb, and BMI 29.58 kg/m2. 51 had osteoarthritis, and five had rheumatoid arthritis. A standard surgical technique was employed utilising flexion axis localisation to position the femoral components. Patients were followed for two years minimum using outcome measures and x-rays. Knees where tibial slope was restored to a degree angle equal to, or slightly greater than, their pre-op slope (group 1) were compared to knees where tibial slope was decreased (group 2).
The average 2 year post-op ROM in Group 1 was significantly greater than that of Group 2 (129.3 degrees vs. 120.5 degrees, p=.001). The average pre-op to post-op increase in ROM in Group 1 was significantly greater than Group 2 (38.1 degrees vs.27.7 degrees, p=.003). Correlational analysis revealed that restoration of pre-op tibial slope was the primary determinant of post-op ROM, followed by pre-op ROM, then weight and BMI (each to significance of p< 0.05).
Restoration of tibial slope clearly produced increased ROM in this study. Using one standard slope cut for every tibia may prevent many patients from achieving their maximum potential ROM.
The abstracts were prepared by Nico Verdoschot. Correspondence should be addressed to him at Orthopaedic Research Laboratory, Universitair Medisch Centrum, Orthopaedie / CSS1, Huispost 800, Postbus 9101, 6500 HB Nijmegen, Th. Craanenlaan 7, 6525 GH Nijmegen, The Netherlands.
