title: Medial patellotibial ligament (MPTL) reconstruction for patellar instability.
abstract: OBJECTIVE
  To evaluate mid-term clinical and radiographic outcomes after an original medial patellotibial ligament reconstruction in patients with patellar dislocation.
  
  
  METHODS
  Twenty-nine knees (27 patients, 8 males and 19 females) treated for patellar dislocation with medialization of the patellar tendon medial third combined with medial and lateral release were evaluated clinically and radiographically at a mean follow-up of 6.1±2.5 years. Trochleoplasty was performed in case of severe flat trochlea (6 knees, 21%). Aetiology of patellofemoral instability was traumatic in 6 (21%) and atraumatic in 23 (79%) knees. The mean age at first dislocation was 19.2±10.1 years. WOMAC, subjective and objective IKDC, Kujala, VAS for pain, Tegner activity and EQ-5D scores were used. Anteroposterior, lateral and 30° axial views were performed for radiographic monitoring.
  
  
  RESULTS
  There was a significant improvement of all clinical scores and significant reduction in knee pain. Twenty-four knees (83%) were normal or nearly normal by objective IKDC score at final follow-up. Radiographs showed a higher incidence of patella alta and flat trochlea in the atraumatic group. Severe signs of patellar osteoarthritis were found in 1 knee (3%). A higher body mass index (BMI) was correlated with worse pre-operative scores. Four knees (14%) were considered failures (2 further dislocations, 2 revision surgeries). The overall survival rate at 6 years was 0.811.
  
  
  CONCLUSIONS
  The presented techniques produced good clinical and radiographic results at mean 6.1 years follow-up, with 14 % failures. Signs of patellofemoral dysplasia were found in patients with atraumatic patellar dislocation. BMI was related to worse pre-operative clinical status.
  
  
  METHODS
  Retrospective study, Level IV.
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica, ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via di Barbiano, 1/10, 40136, Bologna, Italy, s.zaffagnini@biomec.ior.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zaffagnini
authors.forename: Alberto
authors.initials: A
authors.lastname: Grassi
authors.forename: Giulio Maria
authors.initials: GM
authors.lastname: Marcheggiani Muccioli
authors.forename: William F
authors.initials: WF
authors.lastname: Luetzow
authors.forename: Vittorio
authors.initials: V
authors.lastname: Vaccari
authors.forename: Andrea
authors.initials: A
authors.lastname: Benzi
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000293:Adolescent; D000328:Adult; D001178:Arthroplasty / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D010146:Pain / Q000601:surgery; D010329:Patella / Q000000981:diagnostic imaging; D031222:Patellar Dislocation / Q000601:surgery*; D017847:Patellar Ligament / Q000601:surgery; D011859:Radiography; D019651:Plastic Surgery Procedures / Q000379:methods; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult