The Effect of Pressurized Carbon Dioxide Lavage on Osteochondral Allograft

Background: Osteochondral allograft (OCA) transplantation is often utilized for treating osteochondral lesions of the knee due to limited cartilage regenerative capabilities. The use of liquid orthobiologic agents such as bone marrow aspirate concentrate has gained traction as a method to enhance OCA incorporation and healing. Pulse lavage and pressurized carbon dioxide (CO 2 ) lavage are cleaning methods used during OCA preparation to remove native marrow elements, but their isolated and combined effects are not fully understood. Purpose/Hypothesis: This study aimed to assess the impact of incorporating pressurized CO 2 lavage as an adjunct to pulse lavage during OCA preparation. It was hypothesized that adding pressurized CO 2 lavage would enhance the OCA absorption capacity for liquid-based materials such as host-derived marrow constituents. Study Design: Controlled laboratory study. Methods: OCA plugs were harvested from medial hemicondyles. The plugs were divided into 2 groups: one group underwent pulse lavage alone, and the other group underwent pulse lavage followed by pressurized CO 2 lavage (sequential group). The plugs were weighed before and after each cleaning step, and a water-based dye solution was added by dripping. Next, the liquid content was determined by centrifugation and spectrophotometry. Results were analyzed statistically. Results: A total of 34 OCA plugs with a 14 to 18 mm–diameter were harvested. After the cleaning phase, the sequential group showed a significant mean reduction in aqueous weight of 0.253 ± 0.110 g (107% ± 21%) ( P < .0001) and a subsequent mean gain in aqueous weight of 0.231 ± 0.107 g (96% ± 19%) ( P < .0001), after the cleaning and dye-dripping procedures. In contrast, the pulse lavage–only group exhibited a small mean weight gain of 0.028 ± 0.010 g (11% ± 4%) after the dye-dripping procedure. Conclusion: Adding pressurized CO 2 lavage to pulse lavage improved OCA cleaning and increased uptake of an aqueous dye solution used as a surrogate for liquid orthobiologic agents in this ex vivo model. Clinical Relevance: The study findings highlight the potential of incorporating pressurized CO 2 lavage as an adjunct to pulse lavage during OCA preparation. These findings could enhance OCA preparation techniques by improving the removal of donor marrow elements and facilitating the subsequent ingress of fluid into the graft's cancellous portion.