title: TKA outcomes after prior bone and soft tissue knee surgery.
abstract: OBJECTIVE
  Bone surgery around the knee joint could represent a more traumatic prior surgical procedure compared to soft tissue knee surgery and may predispose to differing postoperative total knee arthroplasty (TKA) outcomes. The objective of this study was to analyse the postoperative results as well as complications and failures in two groups of patients that had undergone knee surgery prior to primary TKA (bone surgery and soft tissue surgery) when compared to the no prior surgery group.
  
  
  METHODS
  A retrospective and cohort series of 1,474 primary TKA were evaluated at minimum follow-up period of 2 years: 1,119 primary TKA underwent no prior surgery (1,119 patients) (group A), 85 primary TKA (85 patients) (group B) had prior bone procedure [high tibial osteotomy (n = 64), tibial plateau fracture (n = 10) and patellar realignment (n = 11)], and third group of 146 primary TKA (146 patients) (group C) had undergone a soft tissue procedure [arthroscopy (n = 60) and menisectomy (n = 86)] before primary TKA. All the patients underwent a clinical and radiological evaluation as well as International Knee Society (IKS) scores.
  
  
  RESULTS
  Preoperatively, group B had 40 % of cases classified as stage IV knee arthritis (p < 0.02); while 57 % of cases in group A showed higher levels of knee malalignment (p = 0.001) and group C had lower BMI (p = 0.001). Intraoperative complications revealed no difference. Although group B had the poorest postoperative mean values of knee flexion, TKA procedure improved the preoperative mean values of knee flexion in all the study groups. The postoperative complications were more prevalent in group C (p < 0.001), while the percentage of revision TKA was similar for all study groups (p = 0.5). At 120-month follow-up, the Kaplan-Meier survival curve rates showed no difference (p = 0.29).
  
  
  CONCLUSIONS
  This study confirms that prior knee surgery could be considered a clinical condition predisposed to higher postoperative complication rate in primary TKA compared to the no prior surgery group. After analysing the three study groups, group C showed a higher rate of postoperative local complications and lower IKS knee scores, while the group B showed the poorest postoperative mean values of knee flexion as well as the need for extended surgical approach (TTO approach) was more prevalent in this study group. However, statistical analysis did not reveal a direct correlation between the type of prior knee surgery and TKA failures.
authors: Department of Orthopedics and Traumatology, Exercise and Sports Medicine Group, School of Medical Sciences, State University of Campinas, UNICAMP, Campinas, Brazil, piedade@unicamp.br.
authors: Sérgio Rocha
authors: SR
authors: Piedade
authors: Alban
authors: A
authors: Pinaroli
authors: Elvire
authors: E
authors: Servien
authors: Philippe
authors: P
authors: Neyret
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D053208:Kaplan-Meier Estimate; D007717:Knee / Q000601:surgery; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010027:Osteotomy; D011183:Postoperative Complications / Q000601:surgery; D016059:Range of Motion, Articular / Q000502:physiology; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome