title: Femoral marrow cavity bone harvesting used for arthroscopic refilling of misplaced or enlarged bone tunnels in revision ACL surgery: an arthroscopically supported technique with antegrade intramedullary bone harvesting by a reamer-irrigator-aspirator (RIA) system.
abstract: OBJECTIVE
  In anterior cruciate ligament (ACL) revision surgery, refilling of misplaced or enlarged tunnels frequently requires bone harvesting from the iliac crest. Unfortunately, donor-site pain displays a relevant complication. In order to optimize patients' comfort, we developed a procedure combining minimally invasive intramedullary bone harvesting from the femur with arthroscopic tunnel refilling.
  
  
  METHODS
  Patients with ACL reconstruction failure that were not eligible for one-step revision surgery but required tunnel refilling prior to the next ACL reconstruction were enrolled prospectively. Cancellous bone was harvested intramedullarily from the ipsilateral femur using the reamer-irrigator-aspirator system in a minimally invasive manner. Afterwards, the femoral and tibial tunnels were arthroscopically refilled using cones and push rods. Computer tomography (CT) analyses were carried out before and after the filling procedure. Pain levels were assessed during the entire follow-up. Patients undergoing iliac crest bone harvesting for other reasons served as a control group. Finally, the quality of the newly formed bone stock was evaluated in the subsequent ACL reconstruction procedure.
  
  
  RESULTS
  Five patients were included during a 6-month period. Prior to refilling, tunnel analysis revealed a mean tunnel volume of 7.9 cm(3) at the femur [SD ± 5.3 cm(3)] and of 6.7 cm(3) [SD ± 5.1 cm(3)] at the tibia. The CT analyses further revealed that graft failure was predominantly caused by tunnel misplacement. Post-operatively, pain levels due to intramedullary bone harvesting were significantly lower compared to iliac crest bone harvesting at every analysed time point. Three to five months after tunnel filling, CT analyses showed sufficiently incorporated bone stocks with filling rates of 75 % femoral and 94 % tibial. ACL revision surgery was performed 4-5 months after tunnel filling without any complication.
  
  
  CONCLUSIONS
  Intramedullary bone harvesting from the ipsilateral femur combined with arthroscopic refilling of the bone tunnels ensures a high-quality bone stock for further ACL reconstruction. The clinical relevance is shown by the feasibility of this technique and the significantly reduced pain levels during post-operative recovery.
authors.affiliation: Section of Arthroscopic Surgery, Department of Trauma Surgery, Ludwig-Maximilians-University Munich, Campus Innenstadt, Nußbaumstr. 20, 80336, Munich, Germany, sgrote@med.lmu.de.
authors.forename: S
authors.initials: S
authors.lastname: Grote
authors.forename: T
authors.initials: T
authors.lastname: Helfen
authors.forename: F
authors.initials: F
authors.lastname: Mück
authors.forename: M
authors.initials: M
authors.lastname: Regauer
authors.forename: W C
authors.initials: WC
authors.lastname: Prall
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy / Q000295:instrumentation / Q000379:methods*; D001853:Bone Marrow; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D008297:Male; D012086:Reoperation; D020858:Tissue and Organ Harvesting / Q000379:methods*; D014057:Tomography, X-Ray Computed