Mesenchymal Stem Cell Therapy Regenerates the Native Bone-Tendon Junction after Surgical Repair in a Degenerative Rat Model

BACKGROUND: The enthesis, which attaches the tendon to the bone, naturally disappears with aging, thus limiting joint mobility. Surgery is frequently needed but the clinical outcome is often poor due to the decreased natural healing capacity of the elderly. This study explored the benefits of a treatment based on injecting chondrocyte and mesenchymal stem cells (MSC) in a new rat model of degenerative enthesis repair. METHODOLOGY: The Achilles' tendon was cut and the enthesis destroyed. The damage was repaired by classical surgery without cell injection (group G1, n = 52) and with chondrocyte (group G2, n = 51) or MSC injection (group G3, n = 39). The healing rate was determined macroscopically 15, 30 and 45 days later. The production and organization of a new enthesis was assessed by histological scoring of collagen II immunostaining, glycoaminoglycan production and the presence of columnar chondrocytes. The biomechanical load required to rupture the bone-tendon junction was determined. PRINCIPAL FINDINGS: The spontaneous healing rate in the G1 control group was 40%, close to those observed in humans. Cell injection significantly improved healing (69%, p = 0.0028 for G2 and p = 0.006 for G3) and the load-to-failure after 45 days (p<0.05) over controls. A new enthesis was clearly produced in cell-injected G2 and G3 rats, but not in the controls. Only the MSC-injected G3 rats had an organized enthesis with columnar chondrocytes as in a native enthesis 45 days after surgery. CONCLUSIONS: Cell therapy is an efficient procedure for reconstructing degenerative entheses. MSC treatment produced better organ regeneration than chondrocyte treatment. The morphological and biomechanical properties were similar to those of a native enthesis

The use of hydroxyapatite-coated CAD-CAM femoral components in adolescents and young adults with inflammatory polyarthropathy: ten-year results

Between June 1991 and January 1995, 42 hydroxyapatite-coated CAD-CAM femoral components were inserted in 25 patients with inflammatory polyarthropathy, 21 of whom had juvenile idiopathic arthritis. Their mean age was 21 years (11 to 35). All the patients were reviewed clinically and radiologically at one, three and five years. At the final review at a mean of 11.2 years (8 to 13) 37 hips in 23 patients were available for assessment. A total of four femoral components (9.5%) had failed, of which two were radiologically loose and two were revised. The four failed components were in patients aged 16 years or less at the time of surgery. Hydroxyapatite-coated customized femoral components give excellent medium- to long-term results in skeletally-mature young adults with inflammatory polyarthropathy. Patients aged less than 16 years at the time of surgery have a risk of 28.5% of failure of the femoral component at approximately ten years

The use of hydroxyapatite-coated CAD-CAM femoral components in adolescents and young adults with inflammatory polyarthropathy: ten-year results

Between June 1991 and January 1995, 42 hydroxyapatite-coated CAD-CAM femoral components were inserted in 25 patients with inflammatory polyarthropathy, 21 of whom had juvenile idiopathic arthritis. Their mean age was 21 years (11 to 35). All the patients were reviewed clinically and radiologically at one, three and five years. At the final review at a mean of 11.2 years (8 to 13) 37 hips in 23 patients were available for assessment. A total of four femoral components (9.5%) had failed, of which two were radiologically loose and two were revised. The four failed components were in patients aged 16 years or less at the time of surgery. Hydroxyapatite-coated customized femoral components give excellent medium- to long-term results in skeletally-mature young adults with inflammatory polyarthropathy. Patients aged less than 16 years at the time of surgery have a risk of 28.5% of failure of the femoral component at approximately ten years