Osteochondral Allograft Transplantation: Identifying the Biomechanical Impact of Using Shorter Grafts and Pulsatile Lavage on Graft Stability

Abstract

This study seeks to identify the ability of shorter osteochondral allografts (OCAs) to resist displacement/failure. Additionally, this study seeks to evaluate the effect of pulsatile lavage (PL) on the biomechanical stability of the OCA. Fifteen-millimeter diameter, human cadaveric, OCAs of 4, 7, and 10 mm in depth were harvested for comparison of resistance to compressive and tensile loads. For each group, seven specimens were subjected to tensile loads and three specimens subjected to compressive loads until failure (pullout or subsidence). An additional study group of 10 pulsatile-lavaged OCAs of 15 mm in diameter and 7 mm in depth were introduced for comparison to the original 7 mm depth OCA group. The average tensile forces for failure for the 4, 7, and 10 mm plugs were 23.74, 199.57, and 197.69 N, respectively (p = 1.5 × 10−5). After post hoc analysis of the tensile groups, significant differences in the mean tensile force to failure were appreciated between the 4 and 7 mm groups (p = 4.12 × 10−5) and the 4 and 10 mm groups (p = 1.78 × 10−5) but not between the 7 and 10 mm groups (p = 0.9601). There were no significant differences between the average tensile forces resulting in failure for the 7 mm and 7 mm PL groups (199.57 and 205.2 N, p = 0.90) or compressive forces to failure, respectively (733.6 and 656 N, p = 0.7062). For OCAs of 15 mm in diameter, a commonly used size in practice, plugs of 7 mm in depth showed comparable resistance to pull out and subsidence as 10 mm plugs and significantly better resistance to pull out than 4 mm grafts. PL of allografts prior to insertion did not take away from the structural integrity and stability of the plug.

Metrics of OsteoChondral Allografts (MOCA) Group Consensus Statements on the Use of Viable Osteochondral Allograft

“…A more recent article evaluating OCA bone depth concluded that 7 and 10 mm--length plugs had significantly better resistance to pullout and subsidence than the 4 mm--deep plugs. 4 …”

“…A more recent article evaluating OCA bone depth concluded that 7 and 10 mm-length plugs had significantly better resistance to pullout and subsidence than the 4 mm-deep plugs. 4 With regard to pulsatile lavage, several articles have evaluated the effectiveness of using pulse lavage on allografts to remove marrow elements and debris, 38,41,75 which is considered important to decreasing their potential immunogenicity and bioburden. Ibrahim et al 41 demonstrated that pulse lavage removed a significant amount of marrow content from morselized allograft bone-protein (70.5%), fat (95.2%), and DNA content (68.4%).…”

“…0 0 0 0 0 0 D The ideal depth of a femoral OCA recipient site is 6-10 mm. 4,86 0 0 0 1 1 2 D The osseous component of OCAs should be pulse lavaged with sterile irrigation fluid with or without antibiotics before implantation. 4,38,41,75,81 0 0 0 0 5 5 D…”

Comparison of Initial Stability of Oblong, Large Circular, and Multiple-Plug “Snowman” Osteochondral Autografts for Elongated Focal Cartilage Lesions: A Biomechanical Study in a Porcine Model

“…Specimens were then fixed in an upright orientation in the tensile test machine. A load perpendicular to the articular surface was applied at a rate of 10 mm displacement/minute—the rate chosen based on the methodology from prior studies 3 , 5 —and force-displacement curves were generated to determine pull-out strength (maximum load in newtons) and displacement at maximum load.…”

Osteochondral Allografts in Knee Surgery: Narrative Review of Evidence to Date

“…In a cadaveric study, Babu et al demonstrated that 15 mm diameter OCAs that were 7 mm in thickness were superior to those 4 mm in thickness in mean tensile force to failure and resistance to pull-out. 41 Furthermore, they showed 7 mm thick donor plugs had a mean resistance to pull-out and subsidence comparable to 10 mm thick donor plugs. 41 Ackermann et al reported that OCAs <5 mm in depth were 4.9 times more likely to have subchondral cystic changes at the host-graft junction compared to thicker grafts.…”