Comparison of three patellar tendon anterior cruciate ligament reconstruction techniques with emphasis on tunnel location and outcome. Are our results improving?

In order to determine if recent changes in tunnel placement during anterior cruciate ligament reconstruction are producing better outcomes, the results of three different "bone-patellar tendon-bone" anterior cruciate ligament reconstruction techniques were compared. These techniques were: two-incision with the tibial tunnel at the anterior "footprint" of the anterior cruciate ligament (group I), two-incision with freehand placement of the tibial tunnel in the central or posterior "footprint" (group II), and endoscopic single incision utilizing a guide keying on the posterior cruciate ligament to achieve posterior tibial tunnel location (group III). The femoral tunnel was established with a rear-entry guide for the two-incision techniques. A guide keying off the posterior intercondylar shelf or roof was used for femoral tunnel placement with the endoscopic technique. Subjective rating, Lysholm scores, range of motion, manual and instrumented laxity, and radiographic tibial and femoral tunnel location in the sagittal plane were studied for 33 patients (twelve in group I, nine in group II, twelve in group III) at minimum follow-up of two years. Patients had uniform rehabilitation programs. Statistically significant differences were found between the groups for a number of the variables: the mean maximum manual KT-1000 score was 3.7 millimeters for group I compared to 1.4 millimeters for group III; the mean flexion deficit was 0.5 degrees for group I and 8.3 degrees for group III; tibial tunnels were located 31% posteriorly along the sagittal tibial articular length for group I, while groups II and III were 38% and 43% respectively. Femoral tunnels for groups I and II were located 83% and 79% posteriorly along Blumensaat's line respectively, where as the mean for group III was 69%. Recent techniques (group III) for anterior cruciate ligament reconstruction successfully achieved "posterior" tibial tunnel placement. This was associated with superior results as judged by instrumented laxity measurements. The significance of the endoscopic technique's anterior femoral tunnel location relative to that of the two-incision techniques is uncertain but warrants further study.