[Anterior cruciate ligament reconstruction: patellar tendon autograft versus four-strand hamstring tendon autografts. A comparative study at one year follow-up].

PURPOSE OF THE STUDY

The purpose of our study was to compare outcome at one year after anterior cruciate ligament reconstruction for chronic laxity using the patellar tendon autograft or four-strand hamstring tendon autografts.

MATERIAL AND METHOD

This non-randomized study included 129 consecutive patients operated on between October 1996 and September 1998. Ninety patients were available for assessment at one year: 50 in the patellar tendon group and 40 in the hamstring tendon group. The two groups were comparable for all criteria except sex. A single operator assessed all patients using the IKDC 93 chart. Laxity was measured by comparison with the healthy knee using the KT1000 at maximal manual tension. Preoperative laxity was 8.0 +/- 3.0 mm in the patellar tendon group and 7.6 +/- 3.0 in the hamstring tendon group. All ligamentoplasties were performed arthroscopically using a blind femoral tunnel. The patellar tendon was fixed with two metallic interference screws and the four-strand hamstring autografts with two different methods: an RCI(R) interference screw or a cortical system associating a femoral Endobutton(R) and tibial fixation with a bicortical tibial screw. Lateral tendonesis was performed with the fascia lata in 60% of the patients in the patellar tendon group and in 45% of those in the hamstring tendon group. Rehabilitation exercises were initiated early and were the same in the two groups.

RESULTS

Overall results were satisfactory in more than 80% of the patients in both groups. The final IKDC score was significantly better in the patellar tendon group and subjective patient satisfaction was better in the hamstrings group. Residual pain was significantly less pronounced in the hamstrings tendon group (p=0.004). Laxity was improved significantly better in the patellar tendon group: average residual laxity=2.7 +/- 2.1 mm versus 4.5 +/- 2.8 mm (p=0.03) in the hamstrings tendon group; hard stop at the Lachman test in 96% of the patellar tendon group and 78% in the hamstrings tendon group (p=0.007). Residual laxity was significantly less pronounced in the women in the patellar tendon group. There was no significant difference in laxity by type of fixation in the hamstrings tendon group. Recovery in terms of level of activity and type of sport was the same in the two groups.

DISCUSSION

These two surgical techniques provide good functional outcome at one year with better control of laxity with patellar tendon autografts and better relief of pain with four-strand hamstrings autografts. Longer follow-up would be useful to assess laxity long after hamstring reconstruction. We compared the type of transplant and the fixation method together as a single unity, but progress in four-strand hamstring autograft fixation will certainly allow even more optimal results and improved correction of laxity. In our opinion, the patellar tendon autograft remains the gold standard for high-performance athletes practicing a contact-pivot sport, but both types of ACL reconstruction are most useful. We select patients for four-strand hamstring tendon reconstruction as a function of age, sex, and type of sports activities.