Control of laxity in knees with combined posterior cruciate ligament and posterolateral corner deficiency: comparison of single-bundle versus double-bundle posterior cruciate ligament reconstruction combined with modified Larson posterolateral corner reconstruction.
BACKGROUND
Although many posterior cruciate ligament (PCL) injuries are in combination with posterolateral corner (PLC) injuries, there has been little research on combined injury reconstruction; the literature includes differing recommendations.


OBJECTIVE
Combined PCL plus PLC reconstruction corrects the abnormal posterior translation, varus, and external rotation laxities caused by combined PCL plus PLC deficiency. Furthermore, double-bundle PCL plus PLC reconstruction restores laxity closer to normal than single-bundle PCL plus PLC reconstruction.


METHODS
Controlled laboratory study.


METHODS
Cadaveric knee kinematics were measured electromagnetically in 9 knees with posterior drawer, external rotation, and varus rotation loads applied at sequential stages: intact, PCL-deficient, PCL plus PLC-deficient, double-bundle PCL plus modified Larson PLC reconstruction, and single-bundle PCL plus modified Larson PLC reconstruction. Each graft was tensioned using a laxity-matching protocol.


RESULTS
There was no significant difference between single-bundle and double-bundle PCL reconstruction, in combination with the modified Larson reconstruction, at any angle of flexion. Both combined reconstructions restored posterior drawer, external rotation, and varus laxity so that they did not differ significantly from normal.


CONCLUSIONS
In combined PCL plus PLC deficiency, combined PCL plus PLC reconstruction restored all major laxity limits to normal across the range of knee flexion examined. Double-bundle PCL reconstruction was not better than single-bundle reconstruction in this context.


CONCLUSIONS
The added complexity of double-bundle reconstruction does not seem to be justified by these results. In combined PCL plus PLC-deficient knees, combined single-bundle PCL plus modified Larson PLC reconstruction was sufficient to restore posterior drawer, external rotation, and varus laxity to normal.
Apsingi
Sunil
S
Freeman Hospital, Newcastle, United Kingdom.
Nguyen
Trung
T
Bull
Anthony M J
AM
Unwin
Andrew
A
Deehan
David J
DJ
Amis
Andrew A
AA
D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D012399:Rotation