title: [Patellar tendon injuries after total knee arthroplasty : Classification and management].
abstract: BACKGROUND
  Ruptures of the patellar tendon after total knee arthroplasty represent a rare but severe complication, which in general requires surgical therapy.
  
  
  OBJECTIVE
  To implement a classification and correspondent therapy algorithm in consideration of the current literature for the treatment of patellar tendon ruptures after TKA.
  
  
  METHODS
  A review of the recent literature and the author's experience are summarized in a classification and correspondent therapy algorithm for the treatment of patellar tendon ruptures after TKA.
  
  
  RESULTS
  Ruptures of the patella tendon can be classified as avulsions (Type I), acute (Type II) and chronic ruptures (Type III). Avulsions are often of iatrogenic nature and can be sufficiently treated by transosseous refixation prior to implantation of the revision TKA. Acute ruptures of the patellar tendon can originate from trauma or intraoperative injury. The rupture can be restored by primary suture in combination with a wire cerclage in the case of good tendon quality and the absence of patient comorbidities (Type IIA). In the case of poor tendon quality or existing comorbidities (Type IIB) additional augmentation of the ruptured tendon, utilizing the autologous semitendinosus/gracilis tendon, is recommended. Chronic ruptures revealing a good patellar bone stock (Type IIIA) can be treated by a combination of a semitendinosus augmentation and a turndown quadriceps tendon flap. In the case of a poor patellar bone stock (Type IIIB) transpatellar fixation of the semitendinosus tendon is virtually impossible, so that an allograft augmentation or the use of a soft tissue muscle flap (i. e. the gastrocnemius flap) has to be considered. A failed complex reconstruction with or without infection (Type IIIC) is an invidious surgical task and needs to be addressed by the utilization of a muscle flap, an allograft or a patellectomy with or without arthrodesis.
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland. u.noeth@waldkrankenhaus.com.
authors.forename: U
authors.initials: U
authors.lastname: Nöth
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Trojanowski
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: J C
authors.initials: JC
authors.lastname: Reichert
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Niels-Stensen-Kliniken, Franziskus-Hospital, Georgsmarienhütte, Deutschland.
authors.forename: O
authors.initials: O
authors.lastname: Rolf
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: L
authors.initials: L
authors.lastname: Rackwitz
mesh_terms: D000465:Algorithms; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003131:Combined Modality Therapy / Q000379:methods; D019317:Evidence-Based Medicine; D006801:Humans; D010329:Patella / Q000293:injuries* / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods; D012421:Rupture / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy; D013709:Tendon Transfer / Q000379:methods*; D058971:Tenotomy / Q000379:methods*; D016896:Treatment Outcome
keywords: Arthrodesis; Homografts; Knee arthroplasty, total; Patellar tendon; Rupture