Summary

A randomized controlled trial found no significant difference in healing, measured by tendon gap, between partial and total thickness repair techniques for patellar tendon donor sites in ACL reconstruction.

Abstract

This study compares healing outcomes of the patellar tendon donor site in anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft. We focuses on partial repair (PR group) versus total repair (TR group) of the patellar tendon.

Objective

The primary objective is to evaluate the healing gap of the patellar tendon donor site six months postoperatively using MRI. Secondary objectives include assessing changes in patellar tendon dimensions (length, width, thickness) and functional outcomes using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) score.

Study Design:
This randomized study initially enrolled 75 patients, divided into two groups through block randomization. Two patients were excluded: one due to an iatrogenic patellar fracture and another due to undiagnosed cardiomegaly, leaving 73 patients. These were split into two groups: 38 in the PR group and 35 in the TR group. During follow-up, five patients from the PR group and three patients from the TR group were lost to follow-up.

Intervention:
In the PR group, the donor site was partially repaired, with only the inner one-third of the patellar thickness sutured using absorbable polyfilament sutures. In the TR group, the entire thickness of the patellar tendon was repaired. In both groups, the paratenon was meticulously repaired, and bone grafting was performed at the patellar bone and tibial tubercle donor sites. Other procedures, postoperative care, and rehabilitation protocols were identical for both groups.

Results

Demographic data showed no significant differences between the two groups in terms of age (29.87 ± 1.61 years in PR vs. 26.41 ± 1.51 years in TR, p = 0.12), sex (87.89% male in PR vs. 100% male in TR, p = 0.35), or BMI (25.16 ± 0.64 in PR vs. 23.98 ± 0.55 in TR, p = 0.17).
The primary outcome, the mean tendon gap, was nearly identical between the PR group (2.08 mm) and the TR group (2.20 mm), with no significant difference (p = 0.86, 95%CI -1.50 to 1.26). Similarly, there were no significant differences between the groups in changes to the patellar tendon’s length (p = 0.85, 95%CI -1.82 to 2.19), width (p = 0.38, 95%CI -0.56 to 1.45), or thickness (p = 0.39, 95%CI -0.56 to 1.41).
Functional outcomes, measured by KOOS and IKDC scores, showed no significant differences between the PR and TR groups (KOOS symptom p = 0.73, KOOS pain p = 0.80, KOOS ADL p = 0.57, KOOS Sport p = 0.82, KOOS QOL p = 0.90, IKDC p = 0.37).

Conclusion

The study concludes that there is no significant difference in patellar tendon donor site healing between partial and total repair techniques following ACLR with a BPTB autograft. Patellar tendon dimensions and functional outcomes also did not differ significantly between the groups. The study recommends repairing the paratenon and performing bone grafting to promote donor site healing, regardless of the repair technique used. This suggests that less invasive repair may achieve outcomes comparable to more extensive repair.