EFFECT ON KNEE STABILITY IF FULL HYPEREXTENSION IS RESTORED IMMEDIATELY AFTER AUTOGENOUS BONE-PATELLAR TENDON-BONE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

We sought to determine if knee stability after autogenous bone-patellar tendon-bone anterior cruciate ligament reconstruction was adversely affected by obtaining immediate full hyperextension. We selected patients based on degree of knee hyperextension. Group 1 (46 men and 51 women), with an average of 10 degrees (range, 8 degrees to 15 degrees) hyperextension, was compared with the randomly selected control Group 2 (70 men and 27 women), which had an average of 2 degrees (range, 0 degrees to 5 degrees) hyperextension. The operative knee in both groups, which underwent similar reconstruction of the injured knee, achieved full passive extension equal to the noninvolved knee during the immediate postoperative course. The average KT-1000 arthrometer manual maximum side-to-side differences were 2.4 mm for Group 1 and 2.1 mm for Group 2 (P = 0.13). Seventy-nine patients in Group 1 had KT-1000 arthrometer differences of less than or equal to 3 mm as compared with 85 patients in Group 2. Fourteen patients in Group 1 had KT-1000 arthrometer differences of 4 or 5 mm as compared with eight patients in Group 2. Four patients in each group had KT-1000 arthrometer differences >5 mm. Evidence suggests that restoring and maintaining immediate full knee hyperextension after this type of reconstruction does not adversely affect the ultimate stability of the knee.