For decades, researchers have been investigating different methods of cartilage repair, but no approach has yet risen to “gold standard” status. In the June 24, 2015 edition of JBJS Case Connector, “Case Connections” looks at three different restorative/replacement approaches to cartilage defects.
In the springboard case by Ramirez et al., a high school athlete’s full-thickness glenoid osteochondral defect was filled arthroscopically with particulated juvenile cartilage allograft (see image below).
In an earlier case report by Convery et al., the authors recommended placing additional autogenous bone beneath allografts to augment the host bed and enhance incorporation of the allograft’s osseous shell.
Welsch et al. alert surgeons to the possibility of hypertrophic cartilage opposite a defect that’s treated with a matrix-associated autologous chondrocyte transplant (MACT). And finally, Adachi et al. report on osteonecrosis of the femoral condyles that was treated with tissue-engineered cartilage combined with a hydroxyapatite scaffold enhanced with mesenchymal stem cells.
Although prospective studies with suitable control groups will be needed to prove the efficacy of these and other restorative techniques, early intervention with biologic restoration of the articular surface could eventually have a profound influence on patients with cartilage damage.
The article “Adult human mesenchymal stem cells delivered via intra-articular injection to the knee following partial medial menisectomy” is an interesting report of a randomized, double-blind, controlled study carried out over a 2-year period following subtotal medial menisectomy.
While the positive impact of mesenchymal stem cells (MSCs) on both the meniscus and articular cartilage has been demonstrated in animal models, this study looks at the potentially beneficial effects in humans after partial menisectomy. MSC injection in this setting resulted in no apparent complication secondary to these injections. Pain in patients with osteoarthritis was also improved over 2 years compared to those patients treated only with hyaluronate injection. Most intriguing, though, was that in 24% of patients with lower dose MSC and in 6% with higher dose MSC, there was an increase in meniscal volume on MRI by > 15%. None in the control group showed any volume change.
With the large number of meniscal injuries treated surgically in all age groups, MSC injection following partial menisectomy may prove to be a safe method to decrease osteoarthritic pain and potentially increase the volume of the remaining meniscus.
Osteogenesis imperfecta, also known as brittle-bone disease, is a genetic bone disorder that stunts growth and causes bones to break easily. Doctors recently found that this disease can be treated by injecting babies in utero with bone-forming mesenchymal stem cells. An international team of researchers has treated two babies this way with some success.
The stem cells were extracted from the livers of donors, and the genetically unmatched transplanted cells were accepted by the recipient as their own. “We believe that the stem cells have helped to relieve the disease since none of the children broke bones for a period following the grafts, and both increased their growth rate,” says study leader Dr. Cecilia Götherström, researcher at Karolinska Institute’s Department of Clinical Sciences, Intervention and Technology. “Today, the children are doing much better than if the transplantations had not been given.”