The excursion resistance between the tendon and pulley is an important factor contributing to the limitation of function after surgery to the hand. The administration of hyaluronic acid (HA) in the early rehabilitation after tendon grafting may help to prevent adhesions. We evaluated changes in the excursion resistance between potential sources of flexor tendon grafts and the annular pulley in a canine model after administration of HA.

The intrasynovial and extrasynovial tendons were soaked in 10 mg/ml of HA for five minutes. The excursion resistance between these tendons and the annular pulley of an intact proximal phalanx and that of the same tendons of the opposite foot without administration of HA were evaluated. The tendon of flexor digitorum profundus of the second toe without administration of HA was used as a control.

The gliding resistance of canine tendons was significantly decreased after the administration of HA especially in the extrasynovial tendons. Our findings suggest that the administration of HA may improve the gliding function of a flexor tendon graft.

Purpose: To evaluate repair of articular cartilage.

Methods: Ten cases of ten knees (6 males and 4 females) were evaluated in the current study. Seven knees treated by osteochondral graft including six receiving mosaic plasty and one receiving Pasteurization. Four knees treated by periosteal graft. One knee received both mosaicplasty and periosteal graft. Mean patient age at surgery was 31 years old. Eight knees underwent follow-up MRI, 6 knees underwent follow-up arthroscopy, and 4 knees underwent needle biopsy after informed consent was obtained. The mean period from the surgery to final follow-up was 21 months. The mean period from surgery to follow-up arthroscopy was 10 months.

Results: Seven cases of osteochondral graft presented good regeneration of articular surface by MRI and arthroscopic examination. Two knees receiving mosaic plasty demonstrated regeneration of hyaline cartilage even between the gaps in mosaicplasty. However, the structure of hyaline cartilage differed from that of normal cartilage. Pasteurization in one case also demonstrated good regeneration of hyaline cartilage. One knee treated by periosteal graft demonstrated regeneration of hyaline cartilage. However, the graft area in another such knee was covered by fibrous tissue. One periosteal graft became detached 14 days after surgery. There were no cases showing ossification after periosteal graft.

Conclusion: Periosteal graft could cover a wide defect of articular surface. However, induction of cartilage was not good. Osteochondral graft is a sure method of repairing hyaline cartilage where there is a small defect in the articular surface. Our results from needle biopsy demonstrated hyaline cartilage in the gaps among mosaicplasty areas, but the structure of hyaline cartilage was not good. There is a risk of re-degeneration due to the poor structure of hyaline cartilage. Careful observation is needed in both periosteal graft and mosaic plasty cases.