Biomechanical and geometric characterization of peroneus longus allografts with respect to age.

BACKGROUND: Anterior cruciate ligament injuries are among the most common injuries in high impact sports, and reconstruction is the standard surgical procedure for these ruptures. Reconstructions are often performed using allografts rather than autografts on a case-by-case basis. Controversy exists as to whether or not age of donor tissue plays a factor in the mechanical properties of allografts. METHODS: 38 peroneus longus (PL) tendons were prepared using the two-strand graft technique and then subjected to a cyclic loading test regimen of 1000 cycles to determine material properties. Specimens were grouped based on age to ascertain whether donor age affects the material properties of PL tendons. FINDINGS: Secant modulus of the first cycle was determined to be 150.43 (SD 40.24) MPa. The average magnitude of the dynamic modulus was determined to be 82.81 (SD 24.65) MPa. Specimens were grouped into three distinct groups for analysis (x < 40 yo, 40 yo ≤ x < 60 yo, 60 yo < x). INTERPRETATION: The need for using intrinsic material properties is highlighted. There is no significant difference in any intrinsic material property with respect to age or the fatigue of the tendon as the cycle count increases. Conversely, the measured stiffness of a tendon decreased as function of age with a large effect size. Based on analysis of graft geometries, it was determined that PL tendons become significantly more slender with increased age which result in the observed decrease in stiffness.

Lesión osteocondral extensa de cóndilo femoral; tratamiento en un tiempo con matriz colágena y concentrado de médula ósea: reporte de un caso / Big osteochondral lesion; treatment with collagen scaffold and bone marrow concentrate: case report

El tratamiento de las lesiones osteocondrales de gran tamaño y profundidad resultan un desafío debido a que las técnicas habituales (microfractura o transplante osteocondral autólogo), son insuficientes para cubrir el defecto; eso es particularmente importante en pacientes jóvenes, pues se debe intentar técnicas que generen la menor comorbilidad posible. Presentamos un caso de un paciente de 18 años con una lesión osteocondral de 6 cm2 por 14 mm de profundidad, tratado mediante autoinjerto óseo, concentrado de médula ósea y matriz colágena, con resultados satisfactorios tanto en lo funcional como en lo imagenológico. Esa técnica presenta la ventaja de realizarse en un tiempo y con una fuente de células troncales mesenquimáticas (Médula ósea), validada en la literatura y altamente reproducible.

The treatment of large osteochondral defects represent a challenge, because the common techniques used (micro fracture or osteochondral autologous transplantation) are insufficient to cover the defect; this is particularly important in young patients where we expect the least comorbidity. We report a case of an 18-year-old patient with an ostechondral injury of 6 cm2 and 14 mm deep, treated with bone autograft, bone marrow concentrate and a matrix of collagen with satisfactory functional and images results. This technique has the advantage to be performed in one single time and with a source of mesenchymal stem cells (bone marrow) validated in the literature.