title: The incidence and outcome of patella fractures after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The study was performed to determine the incidence and eventual outcome of patella fractures after anterior cruciate ligament (ACL) reconstructions using bone-patella tendon-bone autograft.
  
  
  METHODS
  Retrospective review.
  
  
  METHODS
  Between 1989 to 1999, 618 consecutive primary, single-incision bone-patella tendon-bone autograft ACL reconstructive procedures were performed by 3 surgeons at our institution. Of this group, 8 (1.3%) had postoperative patella fracture of the donor knee. The charts of these patients were retrospectively reviewed, and patients were followed with physical examination and outcome questionnaires.
  
  
  RESULTS
  The patella fractures occurred at a mean of 57 days after the ACL reconstruction (range, 24-121 days). Five patients sustained indirect trauma, whereas 3 experienced direct trauma. Three patients had nondisplaced transverse fractures treated nonoperatively. Five patients had displaced fractures (3 transverse and 2 Y-shaped) requiring surgical intervention. All 8 patients have full flexion when compared with their opposite knee. Two patients did not regain 5 degrees of hyperextension but were not symptomatic. The mean length of follow-up for the questionnaire was 4 years (range, 1.5 to 6.5 years). The mean score on the Lysholm knee questionnaire was 89.6 (range, 77-98). The mean Single Assessment Numeric Evaluation score was 85.8 (range, 50-100).
  
  
  CONCLUSIONS
  Most cases of postoperative patella fractures, in our experience, have caused minor changes postoperatively and no differences in the outcome of these patients. Seventy-five percent of our patients had excellent or good Lysholm scores. This study confirms previous reports in the literature that observed minimal residual sequelae from postoperative patella fractures after ACL reconstruction with bone-patella tendon-bone autograft.
authors.affiliation: Department of Orthopaedic Surgery, New York University, Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Drew A
authors.initials: DA
authors.lastname: Stein
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Hunt
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Rosen
authors.forename: Orrin H
authors.initials: OH
authors.lastname: Sherman
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology* / Q000628:therapy*; D006801:Humans; D015994:Incidence; D007718:Knee Injuries / Q000453:epidemiology / Q000628:therapy; D008297:Male; D010329:Patella / Q000293:injuries* / Q000601:surgery; D017847:Patellar Ligament / Q000637:transplantation*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome