Addition of the Sartorius Tendon Improves Biomechanics of a Four-Strand Hamstring Anterior Cruciate Ligament Autograft.

PURPOSE: The purpose of this study was to quantify and compare the biomechanical properties and change in graft size when adding the sartorius tendon as a fifth strand to a four-strand ST-G hamstring autograft. Additionally, the sartorius tendon was tested individually to quantify its independent biomechanical properties. METHODS: Four-strand and five-strand hamstring tendon grafts were harvested from matched cadaveric knees (mean age: 81.6 ± 9.8). These matched grafts were biomechanically tested using a MTS servohydraulic test system at a rate of testing representative of physiologic tears. The mean diameter, cross-sectional area, and ultimate load to failure were quantified and compared with a one-sided, paired Student's t-test. A P < .05 was considered statistically significant. RESULTS: The mean diameter of the five-strand graft was significantly larger than the four-strand graft (9.30 ± .84 mm vs 8.10 ± .42 mm; P = .002). The average ultimate load to failure of the five-strand graft was 65.3% higher than the four-strand graft (2984.05 ± 1085.11 N vs. 1805.03 ± 557.69 N; P = .009) and added 14.8% to the diameter of the four strand ST-G autograft. CONCLUSIONS: The addition of the sartorius tendon to a four-strand hamstring autograft significantly increased ultimate load to failure by 65%, graft cross-sectional area by 32%, and graft diameter by 15% compared to a traditional four-strand ST-G autograft. This information can be helpful to surgeons who wish to improve the strength of a four-strand ST-G autograft and for undersized grafts as an alternative to allograft supplementation. CLINICAL RELEVANCE: The addition of the sartorius to the four-strand ST-G hamstring autograft significantly increases the ultimate load to failure and overall graft diameter, which can be particularly helpful in undersized autografts as an alternative to allograft supplementation.

Midterm Safety of Carbon Dioxide Insufflation of the Knee During Arthroscopic Cartilage-Based Procedures.

BACKGROUND: When compared with fluid arthroscopy, carbon dioxide (CO2) insufflation offers an increased scope of view and a more natural-appearing joint cavity, and it eliminates floating debris that may obscure the surgeon's view. Despite the advantages of CO2 insufflation during knee arthroscopy and no reported cases of air emboli, the technique is not widely used because of concerns of hematogenous gas leakage and a lack of case series demonstrating safety. PURPOSE/HYPOTHESIS: To investigate the safety profile of CO2 insufflation during arthroscopic osteochondral allograft transplantation of the knee and report the midterm clinical outcomes using this technique. We hypothesized that patients undergoing CO2 insufflation of the knee joint would have minimal systemic complications, allowing arthroscopic cartilage work in a dry field. STUDY DESIGN: Case series; level of evidence, 4. METHODS: A retrospective chart review was performed of electronic medical records for patients who underwent arthroscopic osteochondral allograft transplantation of the knee with the use of CO2 insufflation. Included were patients aged 18 to 65 years who underwent knee arthroscopy with CO2 insufflation from January 1, 2015, to January 1, 2021, and who had a minimum follow-up of 24 months. All procedures were performed by a single, fellowship-trained and board-certified sports medicine surgeon. The patients' electronic medical records were reviewed in their entirety for relevant demographic and clinical outcomes. RESULTS: We evaluated 27 patients (14 women and 13 men) with a mean age of 38 and a mean follow-up of 39.2 months. CO2 insufflation was used in 100% of cases during the placement of the osteochondral allograft. None of the patients sustained any systemic complications, including signs or symptoms of gas embolism or persistent subcutaneous emphysema. CONCLUSION: The results of this case series suggest CO2 insufflation during knee arthroscopy can be performed safely with minimal systemic complications and provide an alternative environment for treating osteochondral defects requiring a dry field in the knee.