title: Reduction Osteotomy vs Pie-Crust Technique as Possible Alternatives for Medial Release in Total Knee Arthroplasty and Compared in a Prospective Randomized Controlled Trial.
abstract: To compare the gap change between the pie-crust technique and reduction osteotomy to determine their effects on flexion and extension gaps and their success rates in achieving ligament balancing during total knee arthroplasty.
  
  
  
  In a prospective randomized controlled trial, 106 total knee arthroplasties were allocated to each group with 53 cases. If there was a narrow medial gap with an imbalance of ≥3 mm after the initial limited medial release, either reduction osteotomy or pie-crust technique was performed. The changes of extension and flexion medial gaps along with the success rate of mediolateral balancing were compared.
  
  
  
  There was a significant difference in the change of medial gap in knee extension with mean changes of 3.5 ± 0.5 mm and 2.3 ± 0.8 mm in the reduction osteotomy and pie-crust groups, respectively (P < .001). For flexion gap, greater change was found in the pie-crust group compared with the reduction osteotomy group; the mean medial gap changes in knee flexion were 1.1 ± 0.5 mm and 2.3 ± 1.2 mm in the reduction osteotomy and pie-crust groups, respectively. The success rates were 90.6% and 67.9% in reduction osteotomy and pie-crust groups, respectively (P = .007).
  
  
  
  As an alternative medial release method, reduction osteotomy was more effective in extension gap balancing, and pie-crust technique was more effective in flexion gap balancing. The overall success rate of mediolateral ligament balancing was higher in the reduction osteotomy group than in the pie-crust group.
authors: Department of Orthopedic Surgery, Dongguk University Ilsan Hospital, Goyang-si, Gyeonggi-do, Korea.
authors: Ji Hyun
authors: JH
authors: Ahn
authors: Department of Orthopedic Surgery, Dongguk University Ilsan Hospital, Goyang-si, Gyeonggi-do, Korea.
authors: Tae Yeong
authors: TY
authors: Yang
authors: Department of Orthopedic Surgery, Dongguk University Ilsan Hospital, Goyang-si, Gyeonggi-do, Korea.
authors: Jang Yun
authors: JY
authors: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008022:Ligaments / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009985:Orthopedics / Q000379:methods; D010027:Osteotomy; D011446:Prospective Studies; D016059:Range of Motion, Articular
keywords: flexion and extension gaps; ligament balancing; pie-crust technique; reduction osteotomy; total knee arthroplasty