Clinical anatomy of the human Achilles subtendons twist - meta-analysis.

PURPOSE: This study aimed to provide a comprehensive and current overview of the anatomy of the Achilles tendon (AT) twisted structure, as there is a discrepancy in the literature regarding its rotating morphology. METHODS: An extensive literature search was conducted across multiple databases to identify all studies that reported relevant data on the AT torsion, with no date or language restrictions applied. Data was extracted and assessed for this meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included articles was examined using the anatomical quality assessment (AQUA) tool. RESULTS: Seven articles (n=690 limbs) were pooled into this meta-analysis. The prevalence of Achilles tendon torsion types was as follows: type II was the most common (46.7%, 95% CI: 31.6-60.9%), followed by type I (44.7%, 95% CI: 29.8-59.0%), and least commonly, type III (8.6%, 95% CI: 1.8-18.8%). Additionally, morphometric analysis, utilizing the method described by van Gils et al., revealed a mean Achilles tendon torsion of 46.5° (95% CI: 25.1-67.9°). CONCLUSIONS: This meta-analysis underscores the prominent and variable twist within the Achilles tendon among individuals, emphasizing the inherent diversity in AT morphology. Furthermore, the study highlights the importance of considering torsion angle as a potential factor influencing AT pathologies and biomechanical function.

Clinical anatomy of the popliteal artery and its implications in total knee arthroplasty: a systematic review and meta-analysis.

The popliteal artery (PA) is a lower extremity arterial vessel, a continuation of the superficial femoral artery. PA may be injured in the majority of total knee arthroplasty (TKA), as well as arthroscopic surgeries which may lead to acute ischemic injury. Our objective was analyzing morphometry of PA in relation to other structures both in flexion and extension of the knee, highlighting discrepancies in the PA's location in varying positions. Literature was reviewed in regards to morphological qualities, prevalence rates, and variants of PA were pooled. Five cadaveric and 14 radiological studies were included, totalling 1473 lower limbs. We found that PA, when nearing bone, was more predictable and fixed as seen in axial plane one and two centimeters distal to joint line at 0 degrees flexion. The distance between PA and posterior tibial cortex was estimated at 3.3 mm with 95% confidence interval (CI) 2.6-4.1 and 7.8 mm (95% CI 5.1-10.5) respectively. Once PA passed over and nearing the joint it had larger discrepancies with distance comparing the knee in 0 vs 90 degree flexion. Due to rise of TKA, arthroscopic surgeries and connected vascular complications PA has been investigated more frequently, and while majority of publications describes relationships between vessels of popliteal area and specific landmarks conducted with knee in extension, our study also implemented data regarding knee flexion thus encompassing the problem in a more dynamic manner. We believe this provides superior data for identification of PA, especially during knee surgery.

The twisted Achilles tendon microvasculature.

The Achilles tendon (AT) is reportedly the most vulnerable to rupture at the midportion, a section of relative hypovascularity. It has been postulated that the twisted structure of this tendon may constitute a critical factor contributing to increased propensity to vascular compromise, decreased regenerative capacity, and rupture in the midsection of the AT. In this review, we will give an overview of the most relevant research on AT vasculature and twist, and delve into the interplay between the two elements in the context of AT disorders. The pertinent body of research suggests a considerable variability in tendon twist among individuals, which likely constitutes a determining factor in the extent to which vessels coursing along and between AT fibers are compressed during contraction-induced elongation of the tendon. Consequently, further research is necessary to investigate the precise association between tendon torsion and blood flow within the AT.

Gluteal Complex is important in External Snapping Hip: intraoperative identification of syndrome origin and endoscopic stepwise release-a case series.

PURPOSE: External snapping hip syndrome (ESHS) was historically attributed to isolated iliotibial band (ITB) contracture. However, the gluteus maximus complex (GMC) may also be involved. This study aimed to intraoperatively identify the ESHS origin and assess the outcomes of endoscopic treatment based on the identified aetiological type. METHODS: From 2008-2014, 30 consecutive patients (34 hips) with symptomatic ESHS cases refractory to conservative treatment underwent endoscopic stepwise "fan-like" release, gradually addressing all known reasons of ESHS: from the isolated ITB, through the fascial part of the GMC until a partial release of gluteus maximus femoral attachment occurred. Snapping was assessed intra-operatively after each surgical step and prospectively recorded. Functional outcomes were assessed via the MAHORN Hip Outcome Tool (MHOT-14). RESULTS: Twenty seven patients (31 hips) were available to follow-up at 24-56 months. In all cases, complete snapping resolution was achieved intra-operatively: in seven cases (22.6%) after isolated ITB release, in 22 cases (70.9%), after release of ITB + fascial part of the GMC, and in two cases (6.5%) after ITB + fascial GMC release + partial release of GM femoral insertion. At follow-up, there were no snapping recurrences and MHOT-14 score significantly increased from a pre-operative average of 46 to 93(p<0.001). CONCLUSION: Intraoperative identification and gradual addressing of all known causes of ESHS allows for maximum preservation of surrounding tissue during surgery while precisely targeting the directly involved structures. Endoscopic stepwise "fan-like" release of the ITB and GMC is an effective, tailor-made treatment option for ESHS regardless of the snapping origin in the patients with possibility to manually reproduce the snapping.

Complete Arthroscopic Posterior Knee Capsulotomy in Patients With Knee Extension Deficit: Preliminary Results of a Clinical Trial.

Background: Guided physiotherapy and surgical arthrolysis are effective in most patients with knee extension deficit. However, in refractory cases, posterior knee capsulotomy may be needed. Purpose: To assess extension restoration, pain reduction, and functional improvement after arthroscopic complete posterior knee capsulotomy in patients with extension deficit refractory to guided physiotherapy and surgical arthrolysis. Study Design: Case series; Level of evidence, 4. Methods: Included were patients with symptomatic asymmetric extension deficit >3° refractory to at least 6 months of guided physiotherapy and initial arthrolysis (15 patients with 12-month follow-up and 8 patients with 24-month follow-up). The mean duration of extension deficit was 24.6 months. An arthroscopic complete posterior knee capsulotomy was performed with transection of the posteromedial, posterolateral and central capsule, and the posterior septum. The primary outcome measure was knee extension, with hyperextension denoted as negative knee extension values. Secondary outcome measures included visual analog scale (VAS) for pain during maximum effort and exercise, International Knee Documentation Committee (IKDC) score, and Knee injury and Osteoarthritis Outcome Score (KOOS). Results: The mean patient age was 40.0 years (range, 26-70 years); 6 out of 15 patients had developed knee contracture after isolated anterior cruciate ligament reconstruction. The mean knee extension deficit decreased from 16.9° (range, 7° to 45°) preoperatively to -0.2° (range, -5° to 5°) at 12-month follow-up (P = .003) and to -0.3° (range, -5° to 5°) at 24-month follow-up (P = .035). The mean VAS pain score decreased from 3.5 (range, 1-6) preoperatively to 1.1 (range, 0-2) at 12-month follow-up (P = .004) and to 1.5 (range, 0-4) at 24-month follow-up (P = .005). The mean IKDC increased from 37.9 (range, 21-62) preoperatively to 63.9 (range, 46-87) at 12-month follow-up (P < .001) and to 60.9 (range, 39-80) at 24-month follow-up (P = .003). The mean KOOS increased from 45.0 (range, 30-62) preoperatively to 75.3 (range, 49-94) at 12-month follow-up (P < .001) and to 72.3 (range, 49-92) at 24-month follow-up (P = .003). There were no significant differences between 12- and 24-month follow-up in extension deficit or functional outcomes. One patient had a midcalf subcutaneous hematoma 5 weeks postoperatively, requiring evacuation. Conclusion: Arthroscopic complete posterior knee capsulotomy was able to restore knee extension, reduce pain, and improve function, with 12-month follow-up results sustained at 24-month follow-up. Registration: NCT05385393 (ClinicalTrials.gov identifier).

Knee extension contracture with fixed anterior tibia subluxation treated with PCL release and quadricepsplasty: a case report.

58-year-old male presented with knee extension contracture (25°) with iatrogenic fixed anterior tibial subluxation. Consecutive arthroscopic arthrolysis, manipulation under anesthesia, and quadriceps-Z-plasty during one surgery failed to restore flexion. Therefore, shortened posterior cruciate ligament was released, which eliminated subluxation and allowed 115° flexion. Despite physiotherapy, flexion progressively decreased to 70° postoperatively. Revision quadricepsplasty by transverse incisions restored 120° of flexion maintained at 31-months follow-up. International Knee Documentation Committee increased 4/87- > 50/87, Knee injury and Osteoarthritis Outcome 7/100- > 68/100 at follow-up. Posterior cruciate ligament release and repeated quadricepsplasty could be a viable salvage option in severe extension contracture with fixed anterior tibial subluxation.

ACL Mucoid Degeneration-Anterior and Posterior Arthroscopic Decompression for Combined Knee Flexion-Extension Deficit.

Mucoid degeneration of the ACL (MDACL, ACL ganglion cysts) is a disease involving ACL thickening due to accumulation of mucoid substance and fiber degeneration with possible formation of "ganglions". Clinically, it leads to anteroposterior impingement and painful limitation of knee range of motion due to impingement of the anterior portion of the thickened ACL with the intercondylar notch during knee extension and the thickened posterior part of the ligament with posterior structures of the knee in flexion. Different treatment methods have been described, including total or partial resection of the ACL degenerative fibers. However, these techniques do not allow for ACL preservation and are associated with a risk of postoperative instability. Also, most procedures treat anterior impingement only. Therefore, the aim of this technical note is to present an arthroscopic technique allowing for minimally invasive anteroposterior ACL decompression. The technique is focused on evacuation of the interfibrous mucoid substance, ganglions, and bony decompression, as well as maintenance of ligament integrity. Its greatest advantage is that it is safe and ACL-preserving yet allows for comprehensive treatment of all intra- and extra-ligamentous possible reasons of MDACL origin and promoting good healing conditions.

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

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.

Arthroscopic cystectomy and valve excision of popliteal cysts complemented with management of intra-articular pathologies: a low recurrence rate and good functional outcomes in a series of ninety seven cases.

PURPOSE: Arthroscopy in popliteal cyst surgery enables addressing all components of its pathomechanism: the cyst wall, valvular mechanism, and concomitant intra-articular pathologies. Techniques differ as to the management of the cyst wall and the valvular mechanism. This study aimed to assess the recurrence rate and functional outcomes of a cyst wall and valve excising arthroscopic technique with concurrent intra-articular pathology management. The secondary purpose was to assess cyst and valve morphology and concomitant intra-articular findings. METHODS: Between 2006 and 2012, 118 patients with symptomatic popliteal cysts refractory to at least three months of guided physiotherapy were operated on by a single surgeon using a cyst wall and valve excising arthroscopic technique with intra-articular pathology management. Patients were evaluated preoperatively and at a mean follow-up of 39 months (range 12-71) by ultrasound, Rauschning and Lindgren, Lysholm, and VAS of perceived satisfaction scales. RESULTS: Ninety-seven out of 118 cases were available for follow-up. Recurrence was observed on ultrasound in 12/97 cases (12.4%); however, it was symptomatic only in 2/97 cases (2.1%). Mean scores improved: Rauschning and Lindgren from 2.2 to 0.4, Lysholm from 54 to 86, and VAS of perceived satisfaction from 5.0 to 9.0. No persistent complications occurred. Arthroscopy revealed simple cyst morphology in 72/97 (74.2%) and presence of a valvular mechanism in all cases. The most prevalent intra-articular pathologies were medial meniscus (48.5%) and chondral lesions (33.0%). There were significantly more recurrences in grade III-IV chondral lesions (p = 0.03). CONCLUSIONS: Arthroscopic popliteal cyst treatment had a low recurrence rate and good functional outcomes. Severe chondral lesions increase the risk of cyst recurrence.

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.

Transient spontaneous osteonecrosis of the knee (SONK) shortly after SARS-CoV-2 infection: A report of 2 cases.

BACKGROUND: This article describes 2 cases of post-coronavirus disease 2019 (COVID-19) transient spontaneous osteonecrosis of the knee (PCT-SONK) observed in patients who had previously recovered from COVID-19 without corticosteroid administration. OBJECTIVES: The possible pathomechanisms by which a recent SARS-CoV-2 infection may contribute as a causative factor for osteonecrosis are reviewed, and the differential diagnosis and treatment are discussed. MATERIAL AND METHODS: Two patients (males, 45- and 47-year-old) presented with sudden onset knee pain with no trauma history. The pain persisted during rest and at night. On magnetic resonance imaging (MRI), no subchondral bone thickening was observed; bone edema was diffusely distributed in the whole femoral condyle, in contrast to the more focal edema that is typically concentrated mainly around the subchondral region in classic SONK. Both patients were treated nonoperatively with no weight bearing and pharmacological agents, and complete resolution of symptoms was achieved. RESULTS: A follow-up MRI 10 weeks after presentation revealed a near-complete loss of signal in the medial femoral condyle in both patients. CONCLUSION: Orthopedic surgeons should be cautious when sudden knee pain without concurrent trauma or a history of injury occurs shortly after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, even with mild COVID-19 illness. While some studies report the development of post-COVID-19 osteonecrosis after lower doses of corticosteroids and sooner after their administration than in comparable non-COVID-19 cases, our study is the first to report 2 cases with no corticosteroid administration at all. Therefore, the authors believe it adds to the body of knowledge on the potential connections between COVID-19 and PCT-SONK. The transient nature of symptoms and radiological findings suggest that aggressive surgical treatment of non-injury local bone edema occurring shortly after SARS-CoV-2 infection should be avoided.

Cam Impingement of the Knee: Arthroscopic Correction of Posteromedial Tibiofemoral Incongruence.

One of the anatomic variations observable within the knee joint is a reduction in the posterior curvature of the femoral metaphysis proximal to the medial femoral condyle. This curvature is usually concave enough to fit the posterior horn of the medial meniscus (PHMM) during full knee flexion. A reduction in curvature may result in posteromedial tibiofemoral incongruence, a condition characterized by compression of the PHMM in full knee flexion, similar to cam incongruence in the hip joint. Clinical symptoms may occur in deep knee flexion, and progressive degeneration of the PHMM can be observed if this position is not prohibited. For patients in whom activity modification and conservative treatment have failed, surgery may be indicated. We describe arthroscopic treatment allowing for final intraoperative confirmation of the clinical indication for posteromedial tibiofemoral incongruence correction, as well as allowing for the least possible, yet sufficient, amount of correction.

Vitamin D receptor gene polymorphism influence on lumbar intervertebral disc degeneration.

Intervertebral disc (IVD) degeneration is a multifaceted pathology that is the main morphological cause of lower back pain. This study aimed to determine the link between the vitamin D receptor gene single nucleotide polymorphisms (SNPs) and degenerative processes of the lumbar spine. The complete lumbar spinal columns were collected from 100 Caucasian cadavers via ventral dissection. The specimens for the histological analysis were harvested from the L5/S1 IVDs and endplates. Then, the tissues were cut into slices, inserted into paraffin blocks, and stained. The histology was evaluated according to the Boos' protocol. Moreover, TaqI(rs731236), FokI(rs2228570), and ApaI(rs7975232) genotyping were performed. Lastly, the histological scores for different genotypes were analyzed. The overall Boos' score in the study group was 12.49. It consisted of a mean IVD score of 7.46 and endplate score of 5.39. The determination of the SNPs was successful in 99 specimens and had a distribution of all alleles in accordance with the Hardy-Weinberg equilibrium. No significant differences in overall histological degeneration scores were found between samples from donors with different genotypes. However, in subgroup analysis of specific regions on the IVD, the significant difference was found in posterior inner anulus fibrosus for ApaI. The results of this study suggest that one must be careful when interpreting the results of the clinical and/or radiological studies on vitamin D receptor gene polymorphisms and lumbar spine degeneration risk, because such a relationship, if present, is likely to be very subtle.

Duplication and Fenestration of the Inferior Petrosal Sinus: Cadaveric Study with Application to Imaging, Skull Base Surgery, and Neurointerventional Procedures.

BACKGROUND: Reports of a duplicated or fenestrated inferior petrosal sinus (IPS) are scarce or not found in the literature, respectively. To our knowledge, there are no cadaveric reports of the latter. METHODS: This study used 20 adult cadaveric heads (40 sides). After removal of the brain, the IPS was dissected using a surgical microscope. Specimens with duplication or fenestration of the IPS anywhere along its course were photographed and measured. RESULTS: On 2 (5%) left sides, a fenestration was identified in the IPS. One of these was found to have 2 fenestrations. The mean length and width of the 3 fenestrations were 2.3 mm and 0.95 mm, respectively. The 3 fenestrations were located at the middle to terminal parts of the IPS. On 2 (5%) left sides and 1 (2.5%) right side, the IPS was duplicated over a part of its course. The mean length and width of the duplicated parts of the IPS were 25.9 mm and 3.1 mm, respectively. No statistical significance was found for fenestrations or duplications comparing males versus females, but fenestrations were statistically significant (P < 0.05) for occurring on left sides. CONCLUSIONS: Unfamiliarity with a duplicated or fenestrated IPS could increase risk of iatrogenic injury and misinterpretation of imaging. Further radiological imaging studies are required to substantiate more accurately the mechanisms by which a duplicated or fenestrated IPS affects clinical outcomes. Nonetheless, anatomical awareness of such lesser known variations of the IPS is crucial for promoting safe and effective interventional approaches at the skull base.

Anatomical features of the iliocapsularis muscle: a dissection study.

PURPOSE: Iliocapsularis (IC) overlies the anteromedial hip capsule and is an important landmark in anterior approaches to hip arthroplasty. Previously believed to be part of iliacus, few publications describe the prevalence, attachments, fibre direction, blood supply, innervation, and size of IC. This study was aimed to determine these anatomical features using embalmed bodies and whether they vary between sides, sex, and age. METHODS: Thirty-eight formalin-fixed adult bodies were dissected and the prevalence, presence of a connective tissue raphe, attachments, fibre direction, blood supply, and innervation, were documented. Length and width were measured, and significant differences were investigated with t tests. RESULTS: Iliocapsularis was present in all bodies examined, originating from the inferior border of the anterior inferior iliac spine, and inserting 20 mm distal to the lesser trochanter in 54 muscles (71%). Iliocapsularis was supplied by a thin branch from the femoral nerve and by branches of the lateral circumflex femoral and deep femoral arteries and veins. Muscle fibre direction was from superolateral to inferomedial. Mean length was 116.8 ± 11.2 mm and width was 12.8 ± 3.1 mm, with no significant differences between sides, sex, and age. CONCLUSION: This was the first study to document the venous drainage and compare the dimensions with sides, sex, and age, using adult bodies. However, the true function of IC is still unknown. Iliocapsularis is a constant muscle, distinct from iliacus, which is relevant to orthopaedic surgeons and physical rehabilitation specialists, particularly for postoperative patient care.

The Forgotten Intermediate Condylar Canal: Anatomic Study with Application to Skull Base Surgery.

BACKGROUND: The intermediate condylar canal, which lies lateral to the occipital condyles and medial to the jugular foramen, is rarely mentioned in textbooks, even those devoted to the skull base. Therefore the present anatomic study was performed to better elucidate these structures. METHODS: We studied 100 adult skulls (200 sides) to better understand the prevalence and anatomy of the intermediate condylar canal. RESULTS: An intermediate canal was found on 6 of 200 sides (3%). On average, these canals traveled 7.1 mm lateral to the occipital condyle and had a mean of 2.2 mm posteromedial to the jugular foramen. Anteriorly, these canals opened into the external surface of the hypoglossal canal and, when present, were just medial to a paracondylar process for which there was a strong positive correlation. The length of the canals ranged from 5 to 7.8 mm. In all, there were 3 partial canals and 3 complete canals. One left canal communicated anteriorly at the confluence of the inferior opening of a septated (bifurcated) hypoglossal canal and an unnamed foramen medial to the jugular foramen. These canals were distinct from posterior condylar canals when the latter was present. CONCLUSIONS: Knowledge of the anatomic variants at the base of the skull may help minimize complications during surgical procedures that employ a paracondylar or transcondylar approach or approaches to the jugular foramen.

The popliteofibular ligament: a cadaveric ultrasound study.

OBJECTIVE: The popliteofibular ligament (PFL) is an important stabilizer of the knee found within the posterolateral corner (PLC) of the joint. Injuries to the PLC can cause substantial patient morbidity. Accurate PFL visualization has been historically challenging, impeding injury diagnosis and treatment. The gold standard for in vivo PFL visualization is magnetic resonance imaging (MRI), but this procedure has slice thickness limitations, is costly, and is subject to longer wait times. Ultrasonographic (US) PFL assessment is a potentially viable alternative to MRI. This study aimed to determine the viability of US PFL assessment. MATERIALS AND METHODS: Ten fresh-frozen lower limb specimens were evaluated for the presence and morphometric characteristics of the PFL via US using an 18.0-MHz linear transducer. The cadavers were then dissected and reassessed for the presence and morphometric characteristics of the PFLs for comparison with US findings. Moreover, the fracture of the fibular styloid process near the site of the insertion of the PFL (the arcuate sign) was simulated and assessed via US. RESULTS: The PFL was visualized and measured in all ten knees via both US and cadaveric assessments. There were no statistically significant differences in PFL morphometric characteristics determined via US examination and dissection. The fibular styloid fracture was easily identified in US examination. CONCLUSION: US imaging is a viable alternative for accurate and effective assessment of the normal PFL. Moreover, the arcuate sign can be evaluated via US.

The persistent median artery and its vascular patterns: A meta-analysis of 10,394 subjects.

The presence of a persistent median artery (PMA) has been implicated in the development of compression neuropathies and surgical complications. Due to the large variability in the prevalence of the PMA and its subtypes in the literature, more awareness of its anatomy is needed. The aim of our meta-analysis was to find the pooled prevalence of the antebrachial and palmar persistent median arteries. An extensive search through the major databases was performed to identify all articles and references matching our inclusion criteria. The extracted data included methods of investigation, prevalence of the PMA, anatomical subtype (antebrachial, palmar), side, sex, laterality, and ethnicity. A total of 64 studies (n = 10,394 hands) were included in this meta-analysis. An antebrachial pattern was revealed to be more prevalent than a palmar pattern (34.0% vs. 8.6%). A palmar PMA was reported in 2.6% of patients undergoing surgery for carpal tunnel syndrome when compared to cadaveric studies of adult patients in which the prevalence was 8.6%. Both patterns of PMA are prevalent in a considerable portion of the general population. As the estimated prevalence of the PMA was found to be significantly lower in patients undergoing surgery for carpal tunnel syndrome than those reported in cadaveric studies, its etiological contribution to carpal tunnel syndrome is questionable. Surgeons operating on the forearm and carpal tunnel should understand the anatomy and surgical implications of the PMA and its anatomical patterns.