Medial Para patellar versus Sub vastus approach in Total Knee Arthroplasty R.Kattimani, A.Sinha, T.Kumar, I.Smith Glan Clwyd hospital , Rhyl, United Kingdom. Background Component alignment is one of the most important factors for long term survival after total knee arthroplasty. The medial para patellar and sub vastus are two surgical approaches used in knee arthroplasty. A retrospective study was undertaken to analyse which of these two surgical approaches had better component alignment. Results Sub vastus approach had better component alignment in sagittal plane of tibia, coronal plane of femur and tibia (p<0.01). No difference in component alignment at sagittal plane of femur (p>0.05).   Operative time was more in sub vastus group (p<0.05). There was no difference between the two groups in terms of blood loss, duration of stay and complications (p>0.05). Pain was better controlled in sub vastus approach on post-operative day three (p<0.01). Methods A retrospective study of age and gender matched 60 knee arthroplasty operated by either medial para patellar (30) or sub vastus approach (30) from January 2009 to December 2010 by two surgeons. Revision knee arthroplasty and total knee arthroplasty operated by other surgeons were excluded. Student’s t test was used for statistics. Conclusions Sub vastus can be considered as an alternative surgical approach along with standard medial para patellar approach for primary total knee arthroplasty. Acknowledgments Health records department , Glan Clwyd Hospital ,Rhyl. for retrieving the clinical notes Dr.Umesh.Dixit, Associate Professor, Community Medicine, SDM College of Medical Sciences Dharwad. India. for statistics. Dr Sowmya .Sadananadappa for helping in review of literature.