title: Femoral lengthening over an intramedullary nail using the external fixator: risk of infection and knee problems in 22 patients with a follow-up of 2 years or more.
abstract: BACKGROUND
  The time for femoral lengthening is shortened if external fixation is combined with intramedullary nailing. However, several complications have been reported with this procedure.
  
  
  METHODS
  We retrospectively reviewed the outcome of femoral lengthening performed over an intramedullary nail using external fixation in 22 patients. These patients were followed for a mean of 3.2 (2-5.2) years. The mean age was 22 (13-35) years at the time of the index procedure. The mean lengthening was 5 (2.7-8.1) cm and the external fixator was removed after median 20 (8-30) weeks. The mean external fixation index was 24 (11-35) days/cm and the mean consolidation index was 43 (26-55) days/cm of lengthening.
  
  
  RESULTS
  3 patients who had a past history of infection or open trauma developed osteomyelitis which required removal of the nail. There were 4 knee joint complications when the lengthening was over 20%, including posterior knee subluxation and patella subluxation. In 1 patient, the lengthened segment collapsed with breakage of locking screws.
  
  
  CONCLUSIONS
  Although lengthening over a nail can reduce the duration of external fixation, caution is required to prevent major complications.
authors.affiliation: Korea University Medical Center, Kuro Hospital, Seoul.
authors.forename: Hae-Ryong
authors.initials: HR
authors.lastname: Song
authors.forename: Chang-Wug
authors.initials: CW
authors.lastname: Oh
authors.forename: Rakesh
authors.initials: R
authors.lastname: Mattoo
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Park
authors.forename: Sung-Jung
authors.initials: SJ
authors.lastname: Kim
authors.forename: Il-Hyung
authors.initials: IH
authors.lastname: Park
authors.forename: In-Ho
authors.initials: IH
authors.lastname: Jeon
authors.forename: Joo-Chul
authors.initials: JC
authors.lastname: Ihn
mesh_terms: D000293:Adolescent; D000328:Adult; D001852:Bone Lengthening / Q000009:adverse effects / Q000379:methods; D001858:Bone Nails; D016267:External Fixators; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D031221:Knee Dislocation / Q000000981:diagnostic imaging / Q000209:etiology; D007870:Leg Length Inequality / Q000601:surgery*; D008297:Male; D010019:Osteomyelitis / Q000000981:diagnostic imaging / Q000209:etiology; D031222:Patellar Dislocation / Q000000981:diagnostic imaging / Q000209:etiology; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors