All-Inside Meniscal Implant Placement and Risks of Neurovascular Injury: An Arthroscopic, Pediatric Anatomic Study

Background: Pediatric meniscal injury rates and their arthroscopic repair are on the rise. With the growing popularity of all-inside devices used in this potentially higher-risk population, studies examining the proximity of these devices to neurovascular structures are needed. Purpose/Hypothesis: The purpose of this study was to provide distances to neurovascular structures from all-inside devices placed arthroscopically at both high-risk approach angles and zones of the lateral menisci of pediatric cadaveric specimens. It was hypothesized that the neurovascular structures would be situated closely to arthroscopically placed all-inside lateral meniscal devices, particularly the popliteal artery (PA), popliteal vein (PV), and tibial nerve (TN) to devices placed at the posterior root when placed via a lateral portal, as well as the peroneal nerve (PN) to devices placed just medial to the popliteal hiatus via a medial portal. Study Design: Descriptive laboratory study. Methods: The study involved 12 fresh-frozen cadaveric knee specimens (6 matched pairs) between the ages of 6 and 10. Two all-inside meniscal repair implants were placed in the lateral meniscus: 1 via a medial port just medial to the popliteal hiatus and 1 via a lateral port at the visible edge of the posterior root. Specimens were then dissected posteriorly to expose the posterior knee capsule and meniscal implants. The distance measurements between the implants and the PA, PV, TN, and PN were recorded. Results: The distances from the anchors to the PA, PV, TN, and PN ranged from 2.3 to 59.8 mm, 3.5 to 58.0 mm, 5.3 to 63.0 mm, and 6.3 to 40.1 mm, respectively. Implants at the meniscus root were closer to the PA, PV, and TN than implants at the popliteal hiatus (P≤ .001 for all). There was no statistically significant difference in distances to the PN between the 2 implant positions (P = .06). Conclusion: This study illustrates the proximity of neurovascular structures to all-inside devices in pediatric knee specimens, particularly those directed at the posterior horn using the anterolateral portal. Under the conditions of this study, all-inside devices appeared to be safe. Clinical Relevance: This study provides much-needed data to the growing body of knowledge regarding meniscal injuries and repair in the pediatric population.