The Effect of Hyaluronan on Tendon Healing in Rabbits

Purpose: Enhancement of the healing of the tendon-bone junction is important for anterior cruciate ligament reconstruction using the hamstring tendon. We examined the effect of hyaluronan injection into the bone tunnel on the healing of the tendon-bone junction. Type of Study: Experimental study. Methods: The medial half of the patella tendon of Japanese white rabbits was detached from the tibial insertion and transplanted into a drill hole in the tibial tuberosity with a pullout fixation. The bone tunnel was filled with 0.5 mL of hyaluronan (MW, 0.8 million) or without hyaluronan in the contralateral knee as the control. Biomechanical testing was performed at 3 (n = 6) and 6 weeks (n = 4) with histologic analysis (n = 3). Results: Maximum failure load of the patella-patellar tendon-tibia complex in the knee treated with hyaluronan was higher than that in the control side in each rabbit at 3 weeks: 98 ± 6 N in the hyaluronan group and 76 ± 12 N in the control group (P < .01). Histologic analysis showed that hyaluronan improved tendon healing. Although maximum failure load increased in both groups, the failure load was not significant at 6 weeks. Conclusions: Our study found improved tendon healing to bone in the first 3 weeks for Japanese white rabbits treated with hyaluronan. Clinical Relevance: Because hyaluronan treatment produces a clinical effect, even in only the early phase after ligament surgery, it could improve rehabilitation and produce a better outcome for ligament reconstruction.