Mameri, Enzo S.

Background: The microvasculature of the human meniscus has been previously described by Arnoczky and Warren. However, to date, the qualitative and quantitative extra-articular vascular anatomy of the medial meniscus has not been characterized. Purposes: To perform a qualitative and quantitative anatomic study of the extra-articular medial meniscal vasculature and to introduce the novel “medial meniscal artery” (MMA), potentially providing future guidelines for the treatment of meniscal abnormalities. Study Design: Descriptive laboratory study. Methods: A total of 33 unpaired, frozen human cadaveric knees were dissected. The femoral artery was identified and cannulated using an angiocatheter. The arteries were perfused with a red acrylic paint solution, allowing for improved visualization. Artery dimensions and distances were measured using a digital caliper. Perfused specimens were imaged using computed tomography and segmented using 3D reconstruction software to identify vessels and repeat artery measurements digitally. Results: The MMA was consistently identified in all specimens. In 27 (82%) of 33 specimens, the MMA branched directly from the popliteal artery; in 5 (15%), the MMA shared a common trunk with the inferior medial genicular artery; and in 1 specimen (3%), the MMA shared a common branch with the inferior lateral genicular artery. The MMA was easily distinguishable from the superior, inferior, and middle genicular arteries, given its direct course to the medial joint line with terminal branches to the posterior horn of the medial meniscus and deep to the semimembranosus tendon. The MMA exhibited a consistently smaller vessel diameter relative to the genicular arteries. Conclusion: This is the first study to identify and quantitatively describe the MMA in the human knee. The MMA can be identified consistently on gross anatomic dissection in cadaveric donors of varying demographics. Further research is needed to identify and characterize the artery in vivo and to determine the MMA’s role in meniscus preservation surgery. Clinical Relevance: The findings of this study will provide future avenues of research toward understanding medial meniscus vascularization and the genesis of potential degenerative changes when vascularization is poor. This will help to further refine diagnostic and treatment options for meniscus revascularization and compartment preservation. Additionally, this study may help define safe zones in the knee during posterior approaches and expand the base of knowledge for emerging vascular procedures such as genicular artery embolization.

Objectives: The microvasculature of the human meniscus has been previously described by Arnoczky and Warren. However, to date the qualitative and quantitative extra-articular vascular anatomy of the medial meniscus has not yet been characterized. Therefore, the purpose of our study was to perform a qualitative and quantitative anatomic study of the extra-articular medial meniscal vasculature and to introduce the novel “medial meniscal artery” (MMA), potentially providing future guidelines for the treatment of meniscal pathology. Methods: Thirty-three unpaired frozen human cadaveric knees were dissected. The popliteal artery was identified and cannulated with an angiocatheter. The arteries were perfused with a red acrylic paint solution allowing for improved visualization. Artery dimensions and distances were measured using a digital caliper. Perfused specimens were imaged with Computed Tomography scanning and segmented using software to identify vessels and repeat artery measurements. Results: The MMA was consistently identified in all specimens. In 26 of 33 (82%) specimens, the MMA branched directly from the popliteal artery, while in 6, the MMA shared a common trunk with the inferior medial genicular artery (IMGA). The MMA was easily distinguishable from the superior MGA, inferior MGA, and MGA, given its direct course to the medial joint line with terminal branches to the posterior horn of the medial meniscus and deep to the semimembranosus tendon. The MMA exhibited a consistently smaller vessel diameter relative to the genicular arteries. Conclusions: This is the first study identifying and quantitively describing the MMA in the human knee. The MMA can be identified consistently on gross anatomic dissection in patients of varying demographics. The findings of this study will provide future avenues of study toward understanding the medial meniscus vascularization and the genesis of potential degenerative changes when vascularization is poor. This will help to further refine diagnostic and treatment options for meniscus revascularization and compartment preservation. Additionally, this study may help define safe zones in the knee during posterior approaches, as well as furthering the base of knowledge for emerging vascular procedures such as genicular artery embolization. Further research is needed to identify and characterize the artery in vivo and to determine the MMA’s role in meniscus preservation.

Context: Many clinicians, trainers, and athletes do not have a true understanding of the effects of commonly used performance-enhancing drugs (PEDs) on performance and health. Objective: To provide an evidence-based review of 7 commonly used pharmacological interventions for performance enhancement in athletes. Data Sources: PubMed and Scopus databases were searched on April 8, 2022. Study Selection: Systematic reviews (SRs) and meta-analyses (MAs) assessing the performance-enhancing effects of the following interventions were included: androgenic anabolic steroids (AAS), growth hormone (GH), selective androgen receptor modulators (SARMs), creatine, angiotensin-converting enzyme (ACE)-inhibitors, recombinant human erythropoietin (rHuEPO), and cannabis. Study Design: Umbrella review of SRs and MAs. Level of Evidence: Level 4. Data Extraction: Primary outcomes collected were (1) body mass, (2) muscle strength, (3) performance, and (4) recovery. Adverse effects were also noted. Results: A total of 27 papers evaluating 5 pharmacological interventions met inclusion criteria. No studies evaluating SARMs or ACE-inhibitors were included. AAS lead to a 5% to 52% increase in strength and a 0.62 standard mean difference in lean body mass with subsequent lipid derangements. GH alters body composition, without providing a strength or performance benefit, but potential risks include soft tissue edema, fatigue, arthralgias, and carpel tunnel syndrome. Creatine use during resistance training can safely increase total and lean body mass, strength, and performance in high-intensity, short-duration, repetitive tasks. Limited evidence supports rHuEPO benefit on performance despite increases in both VO 2 max and maximal power output, and severe cardiovascular risks are documented. Cannabis provides no performance benefit and may even impair athletic performance. Conclusion: In young healthy persons and athletes, creatine can safely provide a performance-enhancing benefit when taken in controlled doses. AAS, GH, and rHuEPO are associated with severe adverse events and do not support a performance benefit, despite showing the ability to change bodily composition, strength, and/or physiologic measures. Cannabis may have an ergolytic, instead of ergogenic, effect.