title: Complications involving the extensor mechanism after total knee arthroplasty.
abstract: OBJECTIVE
  To overview the complications involving extensor apparatus of the knee following total knee arthroplasty (TKA) and to summarize which are the lines of treatment available and their reported outcomes in literature.
  
  
  METHODS
  A comprehensive search of several databases was performed using as basic keywords "complications after TKA", "extensor mechanism disruption", "periprosthetic patellar fracture", "quadriceps tendon rupture", "quadriceps tendon rupture" isolated or combined with other terms by using Boolean operators. The methodological quality of each article was also evaluated using the Coleman methodology score (CMS).
  
  
  RESULTS
  Twenty-nine studies were evaluated. The mean CMS of the studies selected was 33.1/100. Patellar fractures, requiring surgical treatment when there is rupture of the extensor mechanism or loosening of the patellar component, were treated surgically in 28.1 % of patients. The patellar and quadriceps tendon ruptures were surgically treated with reconstruction or augmented repair, respectively, in 98.6 and 76.5 %.
  
  
  CONCLUSIONS
  Complications involving the extensor apparatus of the knee following a TKA need early and appropriate management to avoid their devastating influence on joint functionality. Management has to be evaluated very carefully based on the site of the lesion, integrity of the prosthetic components and surrounding tissue to restore, and the patients' individual characteristics. The surgical approach for comminuted periprosthetic fractures and reconstruction of torn tendons of the extensor apparatus are needed to restore function and decrease pain, but, given the poor methodological quality of the studies published so far, it is not clear which surgical technique or graft leads to better outcomes. Therefore, there is an absolute need for better designed comparative trials producing clearer and stronger evidence on this critical matter.
  
  
  METHODS
  IV.
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, Rome, Italy. r.papalia@unicampus.it.
authors: Rocco
authors: R
authors: Papalia
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, Rome, Italy. s.vasta@unicampus.it.
authors: Sebastiano
authors: S
authors: Vasta
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, Rome, Italy. ste.dadamio@gmail.com.
authors: Stefano
authors: S
authors: D'Adamio
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, Rome, Italy. erika.albo@gmail.com.
authors: Erika
authors: E
authors: Albo
authors: Department of Musculoskeletal Disorders, Faculty of Medicine and Surgery, University of Salerno, 84081, Baronissi, Salerno, Italy. n.maffulli@qmul.ac.uk.|Centre for Sports and Exercise Medicine, Barts and The London School of Medicine and Dentistry, Mile End Hospital, 275 Bancroft Road, London, E1 4DG, UK. n.maffulli@qmul.ac.uk.
authors: Nicola
authors: N
authors: Maffulli
authors: Department of Orthopaedic and Trauma Surgery, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 200, Rome, Italy. denaro@unicampus.it.
authors: Vincenzo
authors: V
authors: Denaro
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D050723:Fractures, Bone / Q000601:surgery; D006801:Humans; D007718:Knee Injuries / Q000601:surgery; D010329:Patella / Q000293:injuries / Q000601:surgery; D012421:Rupture / Q000601:surgery; D013710:Tendons / Q000601:surgery
keywords: Extensor mechanism; Periprosthetic fractures; Post-operative complications; TKA; Tendon tear