Abstracts Presented at the 7th Biennial Congress of the International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine| Volume 28, ISSUE 9, SUPPLEMENT , e389-e390, September 01, 2012

Paper 94: Is High Flexion Important in Post Operative Total Knee Arthroplasty?



      One of the main shifts in attitude by surgeons is towards obtaining high flexion in knee athroplasty. Surgical techniques, prosthesis design and post operative rehabiliation all contribute to increased knee flexion.
      This study aims to compare functional outcome scores and patient satisfaction rating against post operative knee flexion.


      This is a prospective study of a cohort of 233 patients. Follow up was 4.5 years with 3.2% lost to follow up. The patients' primary diagnosis was osteoathritis.
      The patients were interviewed for the study at 6 weeks, 3 months,6 months, 1 year and then every 2 years.
      Pre-operative scores taken included the KSS, OXFORD, WOMAC, SF12 and VAS Pain Score.
      Post operatively the same scores were taken along with the patient satisfaction questionnaire and compared with knee flexion.
      Orthowave Statistics software was used to generate results.


      57% of the study group were female with an average of 70 years.
      The preoperative data obtained are as follows: Flexion 117° +/− 13°; KS knee Score 41/100; VAS 7/10; SF 12 Mental- 7!, SF 12 Physical – 28.6; Womac 27; Oxford 38.7.
      The Post operative data obtained included.
      Flexion 128° +/− 10°; KS knee Score 95/100; VAS 1/10; SF 12 Mental- 88, SF 12 Physical – 93; Womac 1.07; Oxford 13.17.
      There were no correlations between knee flexion and post operative knee functional scores. However the patient satisfaction questionaire generated statistical correlations with increased flexion. These include: Regular activities, Heavy work, Expectation met (all P<0.05).


      As noted in the results, high flexion(>120) knees do not have a statistically significant difference in validated knee functional scores. However patient satisfaction is statistically higher in the high flexion group.
      This may indicate that validated functional scores are not designed to give better scores for higher flexion. Perhaps modern patients have different functional expectations to patients at the time of inception of these functional scores.


      Our cohort study demonstrates that high flexion does play a role in patient satisfaction and that it does not necessarily correlate with better functional scores. More importantly the high flexion knees have better post operative pain scores, return to regular and heavy activities.