Scientific Literature Review - September 2009
Dennis Patrick Claire
Reference:
Strauss, E., Schachter, A., Frenkel, S., Rosen, J. (2009). The Efficacy of Intra-Articular Hyaluronan Injection After the Microfracture Technique for the Treatment of Articular Cartilage Lesions. The American Journal of Sports Medicine 37(4): 720-726.
Scientific Literature Reviews
Reviewed by: Dennis Patrick Claire, DPM
Residency Program: Saint Vincent Hospital/Worcester Medical Center
Podiatric Relevance:
Hyaluronan-based injections, such as Synvisc, have been routinely used and shown promise in the treatment of knee pathology, but have yet to be established for use in the foot and ankle. The microfracture technique, on the other hand, is commonly used in rearfoot and forefoot surgery. This study provides evidence that the combination of these two techniques may be beneficial for the repair of cartilaginous defects.
Methods:
The study cohort consistedof 36 female white rabbits. A cartilaginous defect was created in the weightbearing area of the medial femoral condyle using a 3 mm biopsy punch and manual excision, exposing the subchondral bone. Microfracture technique was then performed with a 0.035 inch k-wire. One week after surgery, the rabbits were divided into 3 and 6-month cohorts. In each cohort, 6 rabbits were randomly assigned to 3 treatment groups including weekly injections of hyaluronic acid (5mg/0.50mL) for 3 weeks, and another treatment group for 5 weeks, and a final control group of injections of an equivalent volume (0.50mL) of saline for 5 weeks. The cohort groups were sacrificed after their respective courses of 3 and 6 months. Gross and histopathologic evaluations were performed by blinded observers. Gross assessment was made using the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment scoring scale, and histologic assessment was scored via the O’Driscoll histologic system.
Results:
There were no adverse reactions to the injections (treatment or control) noted. The 3-month cohort receiving 3 weekly injections demostrated statistically significant improve in the outcomes measures compared to the control group. The 3-month cohort receiving 5 weekly injections were not significantly different from the 3 weekly injections or control groups. In the 6-month cohort, there were no statistically significant changes. On gross comparison, a greater extent of degenerative changes were noted at 6 months in the control group than either treatment groups. The 5 weekly injection treatment group had a lower incidence of degenerative change, but this did not demonstrate statistical significance. Histologic repair proved significantly better in the 3 weekly injection treatment group at 3 months only.
Conclusions:
Microfracture technique with the addition of hyaluronic acid injections in this rabbit model showed statistically significant repair of a cartilaginous defect over the short term (3 months) with weekly injections over 3 weeks. Although improvement trends were noted in the other treatment groups, they were not statistically significant. The results support the potential for the use of hyaluronic acid injections in combination with microfracture surgical technique in the repair of cartilaginous defects.