Osteoarthritis occurs when the cartilage that covers the opposing bones at a joint erodes away and the bare opposing bones smash into each other causing the bone to crack, fragment and chip. The result is extensive inflammation of the joint and further destruction of the bone, which prompts a knee replacement.
Because knee replacement surgeries are so painful and because they only last about two decades at the most, replacing the lost cartilage is a better option. One surgical treatment for osteoarthritis is microfracture surgery. Microfracture surgery involves the drilling of small holes in the tips of the bones of the joint to serve as conduits for stem cells in the bone to come to the surface and make cartilage.
Unfortunately, there are some problems with microfacture surgery, the most prominent of which is that it works better in younger patients than in older patients. Patients older than 40 years old show a precipitous drop in success after microfracture surgery. Thus, finding some way to increase the activity of cartilage production by endogenous stem cells would be a welcome finding for orthopedic surgeons.
Platelet-rich plasma (PRP) has been used to augment the cartilage-making activities of mesenchymal stem cells from bone marrow. Therefore, some surgeons from South Korea decided to try adding PRP to the knees of patients who had just had microfracture surgery. They examined 49 patients with early arthritis. All of these patients were subjected to arthroscopic microfracture surgery for a cartilage lesion that was less than four cubic centimeters in size. These patients were all between the ages of forty to fifty years old, which means that they were outside the age range for successful microfracture surgery.
These 49 patients were randomly divided into two groups. The first group was a control group of 25 patients that only had arthroscopic microfracture surgery. The second group consisted of 24 patients and they had arthroscopic microfracture surgery and injections of PRP into the knee. 10 patients from each group had follow-up arthroscopies four to six months after the procedure to determine the extent of cartilage restoration. Further evaluations were also done 2 years after the procedure.
The results? There were significant improvements in clinical results between preoperative evaluation and postoperative at 2 years post surgery in both groups (p = 0.017). However in the group that received PRP injections plus microfracture surgery the results were significantly better than those of the control group. These patients had better range of motion and less pain (p = 0.012). In the 2nd look arthroscopies, the cartilage of the patients that received PRP and microfracture surgery was harder and showed increased elasticity than the cartilage of patients that received only microfracture surgery.
The conclusion of these authors: “The PRP injection with arthroscopic microfracture would be improved the results in early osteoarthritic knee with cartilage lesion in 40-50 years old, and the indication of this technique could be extended to 50 years.” (Lee GW et al., “Is platelet-rich plasma able to enhance the results of arthroscopic microfracture in early osteoarthritis and cartilage lesion over 40 years of age? European Journal of Orthopedic Surgery. 2012 Jul 5., epub ahead of publication) If PRP could improve the outcomes of microfracture surgery, then maybe such a technique could extend the groups of patients who are successfully served by this procedure.
While this is an exciting result, we must temper our excitement with the realization that this is a small study and MRIs were not used to measure cartilage thickness. Therefore, while this study is useful and frankly, ingenious, it has its limitations.