Harold M. Aberman

Symptomatic articular cartilage degeneration: the impact in the new millennium.

The symptomatic degeneration of articular cartilage and associated arthritis is among the most prevalent chronic conditions in the United States and the population most at risk is increasing. It is the leading cause of limitations in activities of daily living and is second to heart disease in causing work disability. The current and future socioeconomic impact of chronic articular cartilage disease on the healthcare system will be magnified by increasing numbers of patients who will seek relief of their symptoms and their disability to remain active. Because these individuals live longer and remain active, the proportion of their life living with symptoms and disability from articular cartilage degeneration increases. The economic, psychologic, and social impact of degenerative articular cartilage can be enormous for these individuals but it also impacts their family and society. The direct traditional medical costs and indirect economic and wage loss from arthritis in individuals the United States has reached in excess of

Comparison of pullout strength for seven- and nine-millimeter diameter interference screw size as used in anterior cruciate ligament reconstruction☆

65 billion annually and is expected to increase as the population ages. In addition, the expenditures for complementary and alternative professional services and therapies for arthritis is increasing and is also in the billions of dollars annually. Because of these escalating costs, documenting the value of the patient and cost effectiveness to society of prevention and treatment programs for symptomatic articular cartilage degeneration will be required.

Evaluation of early-stage osteochondral defect repair using a biphasic scaffold based on a collagen-glycosaminoglycan biopolymer in a caprine model.

This study compares biomechanical properties of 7- and 9-mm diameter screws providing interference fixation in anterior cruciate ligament reconstruction. Sixteen pairs of fresh-frozen bovine knees were evaluated. Uniaxial load to failure was performed at a deformation rate of 30 mm/s along the mechanical axis of the ligament graft with the knees secured at 45 degrees of flexion in a custom jig. A video analyzer was used to measure ligament strain and bone-to-bone deformation. Ultimate force, deformation, and failure mode were recorded and compared. The 7-mm screws provided 98% yield strength, and 95% ultimate force compared with the 9-mm screws. The average femoral pullout strength was 1161 +/- 93 N in the 7-mm group and 1198 +/- 142 N in the 9-mm group. Failure mode was similar in both groups. Clinically, the usage of 7-mm screws may reduce iatrogenic injuries to the patellar tendon graft compared with larger screws. This study shows that the biomechanical advantages of 9-mm screws compared with 7-mm screws are minimal.

Association of 3-Dimensional Cartilage and Bone Structure with Articular Cartilage Properties in and Adjacent to Autologous Osteochondral Grafts after 6 and 12 months in a Goat Model.

The aim of this study was to evaluate a new collagen-GAG-calcium phosphate biphasic scaffold for the repair of surgically created osteochondral defects in goats. Comparison of morphological, histological and mechanical performance of the repair tissue was made with defects repaired using a synthetic polymer scaffold. Defects were created in the medial femoral condyle (MFC) and lateral trochlear sulcus (LTS) of Boer Cross goats and evaluated at 12 and 26 weeks. It was found that the total histology score of the collagen-GAG based biomaterial (23.8; SD 1.7) provided a significant improvement (p<0.05) over the biphasic PLGA material (19;3) and the empty control defect (17.3;1.2) in the LTS. The overall trajectory of histological and morphological improvement between 12 and 26 weeks was found to be higher for the collagen-GAG scaffold compared to the PLGA material. The occurrence of sub-chondral bone cysts was lower for the collagen-GAG scaffold with an incidence of 17% of defects, compared to 67% for the PLGA material at 26 weeks. The cartilage repair tissue for both materials evaluated was superior after 26 weeks implantation than the empty control with 75% of the collagen-GAG-treated defects showing markedly more hyaline-like cartilage and 50% of the PLGA sites exhibiting hyaline-like appearances, compared to 17% for the empty control. These early stage data indicate biphasic scaffolds based on collagen-GAG and PLGA both provide indications of satisfactory development of a structural repair to surgically prepared osteochondral defects. Furthermore, the biomaterial composition of the collagen-GAG may provide a more favourable environment for osteochondral repair.

Spontaneous repair of full-thickness defects of articular cartilage in a goat model: A preliminary study

Objective: The articular cartilage of autologous osteochondral grafts is typically different in structure and function from local host cartilage and thereby presents a remodeling challenge. The hypothesis of this study was that properties of the articular cartilage of trochlear autografts and adjacent femoral condyle are associated with the 3-dimensional (3-D) geometrical match between grafted and contralateral joints at 6 and 12 months after surgery. Design: Autografts were transferred unilaterally from the lateral trochlea (LT) to the medial femoral condyle (MFC) in adult Spanish goats. Operated and contralateral nonoperated joints were harvested at 6 and 12 months and analyzed by indentation testing, micro–computed tomography, and histology to compare 1) histological indices of repair, 2) 3-D structure (articular surface deviation, bone-cartilage interface deviation, cartilage thickness), 3) indentation stiffness, and 4) correlations between stiffness and 3-D structure. Results: Cartilage deterioration was present in grafts at 6 months and more severe at 12 months. Cartilage thickness and normalized stiffness of the operated MFC were lower than the nonoperated MFC within the graft and proximal adjacent host regions. Operated MFC articular surfaces were recessed relative to the nonoperated MFC and exhibited lower cartilage stiffness with increasing recession. Sites with large bone-cartilage interface deviations, both proud and recessed, were associated with recessed articular surfaces and low cartilage stiffness. Conclusion: The effectiveness of cartilage repair by osteochondral grafting is associated with the match of 3-D cartilage and bone geometry to the native osteochondral structure.