2013 ISAKOS ABSTRACTS e79

ABSTRACT DATAIntroduction: The Purpose of this study was toidentify the relationship between knee flexion angle andfemoral tunnel length, as well as the exit points of guidepins, when using a far anteromedial (FAM) portal tech-nique for posterolateral (PL) femoral tunnel drilling inanatomic double-bundle anterior cruciate ligament (ACL)reconstruction.Methods: Using the FAM portal technique in 8 cadavericknees, femoral tunnel drilling for the PL bundle was per-formed at 3 knee flexion angles: 90�, 110�, and 130�. Wemeasured the femoral tunnel length and the distances fromeach guide pin to the closest relevant structures on thelateral side of the knee.Results: The mean femoral tunnel length of the PLbundle at 90� knee flexion (25.8 mm) was significantlyshorter than the length at 110� and 130� knee flexion (32.1mm and 33.1 mm, respectively). The average distancebetween the exit point of the guide pin and the posteriorarticular cartilage of the lateral femoral condyle was theshortest at 90� knee flexion (3.3 mm). The distancebetween the guide pin and the center of the origin of thelateral collateral ligament (LCL) was the shortest at 130�

knee flexion (8.0 mm). The guide pins penetrated theorigin of the lateral gastrocnemius tendon in 2 cases at 110�

knee flexion and in 1 case each at 90� and 130� kneeflexion.Conclusions: When using the FAM portal technique,more than 110� knee flexion is desirable in terms of thefemoral tunnel length and the articular cartilage injury ofthe lateral femoral condyle. In addition, the risk of damageto the origin of the LCL increases with an increase in theknee flexion angle to 130�.

Paper #73: Increased Risk of ACL Revision AfterAnteromedial Compared to Transtibial Techniquefor Femoral Drillhole Placement During ACLReconstruction. Result from the Danish Registry ofKnee Ligament Reconstruction LENE RAHR-WAGNER, MD,DENMARK PRESENTING AUTHOR

THEIS MUNCHOLM THILLEMANN, MD, PHD, DENMARK

ALMA PEDERSEN, MD, DENMARK

MARTIN LIND, PROF, MD, PHD, DENMARK $ ClinicalEpidemiological Department, Aarhus, Denmark

SUMMARYIncreased risk of revision after primary ACL surgery

using anteromedial technique for femoral drilling.

ABSTRACT DATAObjectives: The concept of anatomical ACL reconstruc-tion (ACLr) has lead to an increasing use of the ante-romedial portal for femoral drill hole placement due tobetter ability to reach the anatomical ACL footprint. Theanteromedial drilling technique is more challenging whichpotentially could impact outcome and failure rate. TheDanish registry of Knee ligament reconstruction (DKRR)has monitored the quality and development in ACLr since2005 and has registered femoral drilling technique since2007.

The objective of this study is to report revision rates andclinical outcome with the transtibial and anteromedialapproach for femoral drilling during ACLr.Methods: Our prospective cohort investigated 10,901primaryACL reconstruction procedures from theDKRR in theperiod from 2005 to 2011. The survival of the two differentfemoral drilling techniques was determined using revisionACLr as primary endpoint. For statistical analysis KaplanMeier and cox regression analysis were used. Instrumentedknee laxity measurements, KOOS and Tegner scores wereused as functional and patient reported outcome measures.Results: The use of anteromedial approach in Denmarkincreased from 13% in 2007 to 66% in 2011. The cumu-lative revision rate after 2 years using anteromedial femoraldrilling and transtibial femoral drilling was 1.8% and 3.2%,respectively. Anteromedial technique was associated withan increased risk of revision of 1.77 (CI: 1.34-2.33).Furthermore, we observed that the patients with AMtechnique for drill-hole placement had an increased risk ofhaving positive pivot shift test compared to the TT groupwith a risk ratio of 1.54 (1.33;1.77), p<0.01. One yearpostoperatively the KOOS and Tegner scores werecomparable between the two groups.Conclusion: The introduction of anteromedial tech-nique femoral drilling for ACLr has in Denmark resulted inan increased risk of revision compared to transtibial tech-nique. The risk of revision is generally low (5 % within 5years). A slight increase in technical failures due to theintroduction of a new and more complex technique mayexplain the presented findings. Ongoing monitoring of theresults with anatomical ACLr is therefore necessary andexemplifies the importance of a national registry.

Paper #74: Transportal Anatomic Anterior Recon-struction Results in Better Stability Than Conven-tional Transtibial Anterior Cruciate Reconstruction:A Brazilian Clinical Study GUILHERME MOREIRA ABREU-E-SILVA, MD, BRAZIL PRESENTING AUTHOR

MARCO ANTONIO PERCOPE DE ANDRADE, MD, PHD, BRAZIL $ MinasGerais Federal University, Belo Horizonte, Minas Gerais,Brazil

SUMMARYAMP technique reestablished better articular stability

function than TT technique. Less extension deficit wasmore related with transtibial group.

ABSTRACT DATABackground: The traditional transtibial (TT) techniqueusually leads to excellent and good results in more than90% of patients. However, in the last years, biomechanicsand anatomic studies had brought into question its abilityto restore knee’s homeostasis. The anatomic reconstructionconcept was developed, as well the transportal (AMP)approach for femoral tunnel creation, placing the graft ina more anatomic position.Purpose: The objective of this study is to evaluate clin-ical results in patients with anterior cruciate ligamentreconstruction with transtibial or transportal technique, inthe last five years.