A three-headed piriformis muscle: an anatomical case study and narrative review of literature

Introduction: The piriformis muscle (PM) is found in the gluteal region, exiting the pelvis through the greater sciatic foramen and dividing it into the suprapiriform and infrapiriform foramina. The piriformis works as part of the hip external rotator muscle group, and is responsible for rotation of the femur upon hip extension and abduction of the femur during flexion of the hip joint. The aim of the present report is to describe a very rare case of the primary three-headed piriformis muscle. To the best knowledge of the authors, the said variant has not yet been described in the existing literature. Case report: The 71-year-old male formalin-fixed cadaver was subjected to routine dissection. After careful removal of the connecting tissue, three separate, primary heads of the PM were identified. The lower head of the PM arose from the middle part of the sacral bone; 87.56 mm long and 9.73 mm wide. The medial head was attached to the internal part of the posterior inferior iliac spine; 121.6 mm long and 20.97 mm wide. The upper head was attached to the external part of the posterior inferior iliac spine; 78.89 mm long and 23.94 mm wide. All heads converged into a common tendon which inserted onto the greater trochanter. Conclusions: The clinical importance of this work comes down to the fact that the aberrant PM may be the reason behind the piriformis syndrome and its associated symptoms. Moreover, knowledge regarding the variant anatomy of the PM is of immense importance to, e.g., anesthesiologists performing CT- or ultrasound-guided SN injection for local anesthesia, radiologists interpreting imaging studies, and surgeons, especially during posterior approaches to the hip and pelvis

The meta-analysis and systematic review of prevalence and clinical anatomy of the arc of Buhler

Abstract The arc of Buhler (AOB) is a direct anastomosis of the celiac axis and superior mesenteric artery. This paper reviews the literature on the AOB and provides accurate and up-to-date data on its prevalence, anatomy, and clinical significance. The main scholarly online databases were carefully searched for relevant studies related to the AOB. Information was gathered and formed the basis of the analysis of this study. In total, 11 studies were used in this meta-study, consisting of 3685 total patients tested and 50 cases of the AOB presented. The pooled prevalence estimate of the AOB was determined to be 1.7% (95% CI 0.9, 2.9). By imaging type, the prevalence of the AOB was 1.8% for radiological studies (n = 3485; 95% CI 0.9, 3.0), 1.4% for computed tomography (CT) studies (n = 1417; 95% CI 0.4, 3.0), and 1.9% for angiography studies (n = 2068; 95% CI 0.5, 4.0). The AOB is sufficiently significant and should be considered when planning surgeries or radiological procedures involving the abdomen

Aluminum Nanoparticles Affect Human Platelet Function In Vitro

Endoprostheses are prone to tribological wear and biological processes that lead to the release of particles, including aluminum nanoparticles (Al NPs). Those particles can diffuse into circulation. However, the toxic effects of NPs on platelets have not been comprehensively analyzed. The aim of our work was to investigate the impact of Al NPs on human platelet function using a novel quartz crystal microbalance with dissipation (QCM-D) methodology. Moreover, a suite of assays, including light transmission aggregometry, flow cytometry, optical microscopy and transmission electron microscopy, were utilized. All Al NPs caused a significant increase in dissipation (D) and frequency (F), indicating platelet aggregation even at the lowest tested concentration (0.5 µg/mL), except for the largest (80 nm) Al NPs. A size-dependent effect on platelet aggregation was observed for the 5–20 nm NPs and the 30–50 nm NPs, with the larger Al NPs causing smaller increases in D and F; however, this was not observed for the 20–30 nm NPs. In conclusion, our study showed that small (5–50 nm) Al NPs caused platelet aggregation, and larger (80 nm) caused a bridging–penetrating effect in entering platelets, resulting in the formation of heterologous platelet–Al NPs structures. Therefore, physicians should consider monitoring NP serum levels and platelet activation indices in patients with orthopedic implants

Arthroscopic Trans-septal Portal of the Knee With Direct Visualization and No Need for Posterolateral Portal Creation

Arthroscopic visualization and access of the posterior knee are limited when using standard anterior and posterior portals. The creation of a trans-septal portal allows for complete access to the posterior compartment as arthroscopic instruments are able to be passed back and forth between the posteromedial and posterolateral compartments. Due to the close proximity of the popliteal artery and its branches, precise portal placement and safe orientation of arthroscopic instruments are critical to avoid iatrogenic injury. The conventional technique of trans-septal portal creation, involving a posterolateral portal, can be difficult in some cases. To overcome these obstacles, a posteromedial technique of trans-septal portal creation is presented. By using the medial parapatellar portal as the viewing portal, our technique allows for direct visualization of the posterior septum on each step of creation of the trans-septal portal, eliminating the need for “blind” maneuvers. What is more, no posterolateral portal is needed, decreasing the risk of potential complications. Using the posterior cruciate ligament fibers as a main landmark for trans-septal portal placement, preservation of the posterior part of the septum is achieved. This ensures optimal safe-margin distance away from the popliteal neurovascular bundle and making the technique safe and reproducible

Patellar Base Support Technique During Manipulation Under Anesthesia for Knee Arthrofibrosis Limits the Risk of Iatrogenic Complications

Knee extension contracture is a common postinjury and postsurgical complication, which decreases knee joint flexion. Many techniques have been described in the literature to restore knee flexion, with the most common one being an arthroscopic lysis of adhesions. However, in severe cases, additional intra- and extra-articular procedures are needed to restore full knee flexion. Manipulation under anesthesia (MUA) is one of them. Unfortunately, it may lead to devastating complications, such as iatrogenic rupture of the patellar tendon or fractures of the patella or tibial tuberosity. Therefore, the purpose of this report is to present a safer modification of MUA for knee extension contracture in cases in which excessive force is demanded to achieve flexion. The key aim of the “patellar base support” technique (PBS technique) is to stretch the contracted quadriceps muscle with controlled and decreased tension on the patella, patellar tendon, and tibial tuberosity