title: A "sandwich" method of reconstruction of the medial patellofemoral ligament using a titanium interference screw for patellar instability in skeletally immature patients.
abstract: BACKGROUND
  No standard surgical procedure for medial patellofemoral ligament (MPFL) reconstruction exists in skeletally immature patients with patellar instability. This study aimed to evaluate the clinical effectiveness of a novel reconstruction technique for the MPFL in patients with patellar instability because of non-closure of the epiphyseal line.
  
  
  METHODS
  The "sandwich" method was fixation of the patella between a double-stranded semitendinosus tendon through the posterior third of the femoral insertion of the medial collateral ligament (MCL) as a pulley with a titanium interference screw in a single patellar tunnel. Five knees in five patients were studied: four with recurrent and one with habitual patellar dislocations. Subjects underwent MPFL reconstruction with or without lateral release. Patients were evaluated using pre-operative and post-operative physical and radiographic examinations, including apprehension testing, assessment of tilting and congruence angles, medial and lateral shift ratios under stress measured using X-ray imaging, and Kujala and Lysholm scores.
  
  
  RESULTS
  No patient experienced recurrent post-operative episodes of dislocation or subluxation. By the final follow-up, patellar apprehension had disappeared in all patients. In addition, all patients showed significant improvement in the following: tilting angle, congruence angle, lateral shift ratio, Kujala score, and Lysholm score.
  
  
  CONCLUSIONS
  The MPFL reconstruction methods, using a double-stranded semitendinosus autograft and sparing the femoral physeal line in non-closure of the epiphyseal line, provide acceptable short-term results for the treatment of patellar instability.
authors.affiliation: Department of Orthopaedics, Shimane University, School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan. n-kuma@med.shimane-u.ac.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kumahashi
authors.forename: Suguru
authors.initials: S
authors.lastname: Kuwata
authors.forename: Taku
authors.initials: T
authors.lastname: Tadenuma
authors.forename: Masaru
authors.initials: M
authors.lastname: Kadowaki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uchio
mesh_terms: D000293:Adolescent; D001863:Bone Screws; D002648:Child; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007719:Knee Joint; D008023:Ligaments, Articular / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods; D010329:Patella; D012189:Retrospective Studies; D014025:Titanium
chemical_list: D014025:Titanium