title: Selective Medial Release Technique Using the Pie-Crusting Method for Medial Tightness During Primary Total Knee Arthroplasty.
abstract: The pie-crusting method is popular in releasing lateral tightness during primary total knee arthroplasty (TKA) but is not well described for medial release. We established a selective medial release technique using the pie-crusting technique and investigated the effectiveness and safety of the technique during primary TKA.
  
  
  
  We retrospectively reviewed 729 primary TKAs with varus deformity between October 2009 and June 2012. Medial tightness in flexion was released by traditional subperiosteal stripping for the anterior portion of the medial collateral ligament (aMCL). Medial tightness in extension was released by the pie crusting for the tight fibers in the posterior portion of the MCL and/or posteromedial corner structures (pMCL/PMCS). Clinical outcomes were evaluated by Knee Society (KS) scores and the Western Ontario and McMaster Universities Osteoarthritis Index. Any complications, including late medial instability that may be related to our surgical technique, were carefully inspected.
  
  
  
  Among the 729 knees, 170 (23.3%) required subperiosteal stripping for balancing in flexion only, 186 (25.5%) required the pie-crusting for balancing in extension only and 142 (19.5%) required subperiosteal stripping and the pie-crusting for balancing in flexion and extension. The KS knee score was improved from 52.5 to 83.4, KS function score from 58.2 to 91.9, and Western Ontario and McMaster Universities Osteoarthritis Index from 42.7 to 21.8 (P < .001, all). No specific complications related to our technique were identified.
  
  
  
  The selective medial release technique appears to be an effective and safe method to obtain a balanced mediolateral gap in primary TKA.
authors.affiliation: Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Chul-Won
authors.initials: CW
authors.lastname: Ha
authors.affiliation: Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Yong-Beom
authors.initials: YB
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Choong-Hee
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Soo-Ik
authors.initials: SI
authors.lastname: Awe
authors.affiliation: Department of Orthopedic Surgery, Jeju National University Hospital, Jeju National University School of Medicine, Jeju, South Korea.
authors.forename: Yong-Geun
authors.initials: YG
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000601:surgery*; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies
keywords: medial collateral ligament; pie crusting; selective release; total knee arthroplasty; varus knee