Knee Cartilage Repair Technique Spurs Regeneration

A natural tissue graft can stimulate regeneration and improve symptoms in patients who have cartilage damage to their knee, according to a new study.

Researchers at the Hospital for Special Surgery (HSS; New York, NY, USA) conducted a study that examined use of the De Novo natural tissue (NT) graft to treat 17 patients who suffered from focal patella-femoral cartilage lesions with an average lesion size of 203 millimeters. The researchers compared symptom assessment and subjective survey scores of international knee documentation committee (IKDC) evaluation forms and magnetic resonance imaging (MRI) data at baseline and at two years of follow-up.

At follow-up, the patients had roughly a 30% improvement in IKDC health evaluation form scores, a 20% improvement in the IKDC subjective form, and a 25% improvement in the Knee Outcome Survey form. The patients also showed improvements on MRI scans, in both traditional MRI technology as well as quantitative T2 mapping. The improvement was demonstrated in both superficial and deep components of the repair tissue, demonstrating that it still differed from normal cartilage. The study was presented at the annual meeting of the American Orthopedic Society for Sports Medicine (AOSSM), held during July 2013, in Chicago (IL, USA).

The De Novo NT Graft, a product of Zimmer (Warsaw, IN, USA) is made of minced cartilage from organ donors under the age of 13. Unlike cartilage in adults, the younger tissue has a high proliferative capacity. Cells from the transplanted cartilage escape or migrate into surrounding area tissues, multiply, and form a new cartilage tissue matrix that integrates with the surrounding host tissue. The technique eliminates the need for tissue harvesting and requires less suturing, since the product uses a fibrin sealant to secure the particulated tissue pieces into the lesion.

“The small pieces of juvenile cartilage are less than a millimeter in size, and what happens is the cells can migrate out of these small pieces of cartilage,” said lead author and study presenter orthopedic surgeon Scott Rodeo, MD, co-chief of the sports medicine and shoulder service at the HSS. “De Novo NT compares favorably to our existing techniques, given that it is easy to do and involves a one-step procedure. We are cautiously optimistic. It clearly regenerates tissue, but we need further long-term follow up.”

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