title: Navigational predictors in determining the necessity for collateral ligament release in total knee replacement.
abstract: The requirement for release of collateral ligaments to achieve a stable, balanced total knee replacement has been reported to arise in about 50% to 100% of procedures. This wide range reflects a lack of standardised quantitative indicators to determine the necessity for a release. Using recent advances in computerised navigation, we describe two navigational predictors which provide quantitative measures that can be used to identify the need for release. The first was the ability to restore the mechanical axis before any bone resection was performed and the second was the discrepancy in the measured medial and lateral joint spaces after the tibial osteotomy, but before any femoral resection. These predictors showed a significant association with the need for collateral ligament release (p < 0.001). The first predictor using the knee stress test in extension showed a sensitivity of 100% and a specificity of 98% and the second, the difference between medial and lateral gaps in millimetres, a sensitivity of 83% and a specificity of 95%. The use of the two navigational predictors meant that only ten of the 93 patients required collateral ligament release to achieve a stable, neutral knee.
authors.affiliation: Bay Pines Orthopaedic Research Institute, Bay Pines Health Care System, Building 100, Office 3A-158, 10 000 Bay Pines Boulevard Bay, Pines, Florida 33744, USA. samhakki@gmail.com
authors.forename: S
authors.initials: S
authors.lastname: Hakki
authors.forename: S
authors.initials: S
authors.lastname: Coleman
authors.forename: K
authors.initials: K
authors.lastname: Saleh
authors.forename: V J
authors.initials: VJ
authors.lastname: Bilotta
authors.forename: A
authors.initials: A
authors.lastname: Hakki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D016916:Joint Deformities, Acquired / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000601:surgery*; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome