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Autologous Tissues

The use of autologous tissues about the knee has been commonplace for several years, and has included the transplantation of local tissue, transfer of remote tissue, and finally the genetic production of cloned tissue from knee cartilage cells .

A technique that has been used in the knee is transfer of autologous tissue from other areas to reconstruct the articular cartilage; this technique has been termed mosaicplasty. Likewise in the humerus, the technique is certainly applicable. In one study, Scheibel et al. They have prospectively analyzed a series of autologous osteochondral plugs from the knee to the humerus in eight patients. The lesions were all Outerbridge grade IV and averaged 150mm2.

Standard radiographs, MRI, and second-look arthroscopy (in two patients) were used to assess the transplanted tissue. After a mean of 32.6 months MRI revealed good osteointegration and congruent articular cartilage in all but one patient. Second-look arthroscopy in two cases revealed good integration macroscopically with an intact articular surface. The Constant scores also increased significantly. The study certainly lends credence to the use of the procedure in the cases of limited lesions of the humeral head.

In cases where the lesion is larger or the availability of normal cartilage from another autogenous source precludes mosaicplasty, periosteal tissue has been employed. Basic science studies have shown that neochondrogenesis can be seen in animal models where a free autogenous periosteal graft is applied to full thickness articular cartilage lesions.

Periosteum contains pluripotential mesenchymal stem cells with the cambium layer being responsible for many growth factors that regulate chondrocytes and cartilage development including transforming growth factor β1, insulin-like growth factor 1 and others . In a limited series of patients, a tissue quite similar to articular cartilage was observed in the knee .

In the shoulder, a prospective series of five patients treated with an autogenous periosteal flap following microfracture of the defect has shown satisfactory short-term results . The technique included the use of the technique of Steadman et al. Where perforations into the subchondral bone at a distance of 3 to 4 mm between perforations were created. A periosteal flap harvested from the proximal humeral metaphysis (with the cambium layer facing the cartilage lesion) was then applied to the defect and sutured into place .

The size of the defects in these patients averaged 311 mm2 (range 225 to 400 mm). With a mean follow-up of 25.8 months, it was found that the Constant scores improved significantly from 43.4 to 81.8. Second-look arthroscopy in three patients revealed a significantly reduced cartilage lesion.

Follow-up MRI revealed that the area of the chondral defect was covered with a thin layer of regenerated cartilage tissue in all patients, but there were still signs of edema in the underlying subchondral bone plate. It was felt that this is a viable technique for larger defects not amenable to treatment with osteochondral plugs.

Although the findings did not show a completely normal cartilaginous surface, the authors were encouraged by the improvement in clinical symptomatology. Certainly, further follow-up is indicated in these patients before the technique can be espoused for most defects.

An additional autogenous technique that has been extensively analyzed with respect to the knee is that of autogenous chondrocyte implantation (ACI) . The technique involves the use of cells that are harvested from the articular cartilage surface, subsequently cultured in vitro, and reimplanted under a periosteal patch. In the shoulder, the technique has been reported in the form of a case report.

The patient in this case sustained a lesion that, following preparation for the ACI procedure, measured 3.3 × 1.5 cm. At one year follow-up the patient demonstrated a full range of painless motion with no complaints of rest or weather change pain.

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