title: Surgical technique: articulated external fixator for treatment of complex knee dislocation.
abstract: BACKGROUND
  Knee dislocation is a severe but relatively uncommon injury caused by violent trauma that can result in long-term complications, such as arthrofibrosis, stiffness, instability, and pain. Perhaps owing in part to its rarity, treatment of this injury is controversial. We therefore describe a treatment approach for these complex cases involving a novel dynamic knee external fixator.
  
  
  METHODS
  We performed open PCL reconstruction when possible and/or repair of other associated lesions. At the end of the surgical procedure, the surgeon applied an external fixator that reproduced normal knee kinematics, allowing early motion exercises and reducing the risk of joint stiffness while protecting the bony and soft tissue structures involved in the repair during the first healing phase.
  
  
  METHODS
  We retrospectively reviewed eight patients treated with this approach, four of whom had the PCL reconstructed and four of whom had only associated injuries reconstructed. We evaluated all patients with clinical scores (subjective International Knee Documentation Committee form, Lysholm score, and Tegner level), physical examination (objective International Knee Documentation Committee form), and KT-1000™ arthrometer for AP laxity. Minimum followup was 10 months (mean, 26 months; range, 10-45 months).
  
  
  RESULTS
  One patient had manipulation under anesthesia. The median Lysholm score was 76, Tegner level was 4, and subjective International Knee Documentation Committee was 73. All patients recovered to their preinjury work activity, except one unemployed patient. Stability was normal or nearly normal in five patients; the mean side-to-side difference in AP displacement with manual maximum force was 2.9 mm.
  
  
  CONCLUSIONS
  This approach with an external fixator allowed staged reconstruction and early motion and provided reasonable stability, ROM, and activity level at followup in patients with complex injuries.
  
  
  METHODS
  Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors: 3rd Orthopaedics and Traumatologic Clinic, Rizzoli Orthopaedic Institute, Via Pupilli 1, 40136 Bologna, Italy.
authors: Maurilio
authors: M
authors: Marcacci
authors: Stefano
authors: S
authors: Zaffagnini
authors: Tommaso
authors: T
authors: Bonanzinga
authors: Andrea
authors: A
authors: Pizzoli
authors: Mario
authors: M
authors: Manca
authors: Enzo
authors: E
authors: Caiaffa
mesh_terms: D001696:Biomechanical Phenomena; D004867:Equipment Design; D016267:External Fixators; D006801:Humans; D031221:Knee Dislocation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology; D008023:Ligaments, Articular / Q000293:injuries; D015915:Motion Therapy, Continuous Passive; D011859:Radiography; D019651:Plastic Surgery Procedures / Q000379:methods; D012189:Retrospective Studies