Abstract: Introduction: Total knee Arthroplasty (TKA/TKR) is frequently performed surgery in patients with osteoarthritis, above 50 years age. TKR decreases pain, increases patient ability to walk independently. This decreases dependency on others in elderly age. This will help them to carry-out daily activities of living, at times daily activities of earning in that old age.
Aim: To study variability of alpha angle post-operatively in knee, with same preset 5o valgus cut angle.
Null Hypothesis: We propose that preset 5o valgus cut angle (distal femur cut) will have same alpha angle of 95o in all knee post-operatively.
Materials and methods: Patients admitted into BIRRD (T) Hospital for TKR during the March 2017 to March 2018 were included into study, after satisfying inclusion and exclusion criteria. Radiological evaluation was done pre and post-operatively. Varus (pre and post-operative), alpha angle and other angles were calculated. Results were tabulated and statistical evaluation done.
Results: Sixty-two patients were included in the study. Average age was 60 years. There were twenty six male and thirty six female patients. Average pre-operative Varus was 183o and post-operative correction obtained was 177o. Average alpha angle was 94.9o, beta angle 89.4o. Alpha angle varied from 90o-99o while beta angle varied 80o-94o in our study.
Conclusion: Preset 5o valgus distal femur cut cannot determine alpha angle. Alpha angle is dependent upon many factors like entry-point of intramedullary guide, over-reaming of entry point, isthmus diameter of femur, cutting difference of medial and lateral condyles in distal femur cut. Null hypothesis remains rejected.
