THE RELATIONSHIP BETWEEN TUNNEL PLACEMENT AND CLINICAL-RESULTS AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

To correlate clinical results after anterior cruciate ligament reconst ruction with tunnel placement measured radiographically, we prospectiv ely studied 128 patients who had arthroscopically assisted bone-patell ar tendon-bone reconstructions. Patients with bilateral anterior cruci ate ligament reconstructions, other significant knee ligament injuries , or those undergoing chondroplasty or meniscal repairs were excluded, leaving 42 patients. The relationship between radiographic tunnel pos ition and clinical results was determined using the Lysholm score, KT- 1000 arthrometer testing, the Tegner activity level, and the pivot shi ft and Lachman tests. Clinical results correlated positively with post erior femoral tunnel placement on lateral radiographs and negatively w ith excessive anterior tibial tunnel placement. Specifically, when fem oral tunnels were placed at least 60% posterior along Blumensaat's lin e and tibial tunnels were at least 20% posterior along the tibial plat eau, 69% of patients had good or excellent Lysholm scores and 79% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. When the above criteria were not met, 50% of patients had good or excellent Lysholm scores and 22% had KT-1000 arthrometer maximum ma nual side-to-side differences of 3 mm or less. This close correlation indicates that satisfactory radiographic tunnel position influences ou tcome after anterior cruciate ligament reconstruction.