Defining the popliteal fossa by bony landmarks and mapping of the courses of the neurovascular structures for application in popliteal fossa surgery

Surgical access to the posterior knee poses a high-risk for neurovascular damage. The study aimed to define the popliteal fossa by reliable bony landmarks and comprehensively mapping the neurovascular structures for application in posterior knee surgery. Forty-five (20 male, 25 female) embalmed adult cadaveric knees were included. The position of the small saphenous vein (SSV), medial cutaneous sural nerve (MCSN) and lateral cutaneous sural nerv (LCSN), tibial nerve (TN) and common fibular nerve (CFN) nerves, and popliteal vein (PV) and popliteal artery (PA) were determined in relation to either medial (MFE) or lateral (LFE) femoral epicondyles, medial (MTC) and lateral (LTC) tibial condyles and the midpoint between the MFE and MTC and LFEF and LTC. The distance between the MFE and the PA, PV, TN, MCSN, and SSV was 38.4±12.1 mm, 38.4±12.9 mm, 39.4±10.2 mm, 39.2±14.0 mm and 37.6±12.5 mm respectively for males and 34.6±4.9 mm, 32.8±5.6 mm and 38.0±8.1 mm 38.8±10.1 mm and 37.9±8.2 mm respectively for females. The distance between LFE and the CFN and LCSN was 13.4±8.2 mm and 24.9±7.3 mm respectively for males and 8.4±9.1 mm and 18.4±10.4 mm respectively in females. This study defined the popliteal fossa by reliable bony landmarks and provided a comprehensive map of the neurovascular structures and will help to avoid injuries to the important neurovascular structures.https://acbjournal.org/main.htmlhj2021Anatom

An anatomical investigation into the blood supply of the proximal humerus : surgical considerations for rotator cuff repair

BACKGROUND : The purpose of this study was to investigate the blood supply of the humeral head (HH) originating from the anterior (ACHA) and posterior circumflex humeral arteries (PCHA). METHODS : Formalin preserved specimens were used to measure ACHA length, ACHA length in the bicipital groove (BG), the length of the ascending branch of the ACHA, the penetration point of the ascending branch of the ACHA at the greater tuberosity (GT), and the penetration point of the ascending branch PCHA at the GT. Fresh specimens were used to identify the intraosseous vascular network by both the ACHA and PCHA by injecting a contrast medium using a high-resolution microfocus computed tomography. Specimens were then dissected to expose where the branches of the ACHA and PCHA penetrate the bone, and a small section of the medial head was removed to visualize dye penetration of the cancellous bone. RESULTS : Seven variations for the course of the ACHA were observed. In 36%, the ACHA runs posterior to the BG and posterior to the long head of biceps tendon, and splits into the anterolateral ascending and descending branch. The ascending branch enters the medial wall of the GT. Microfocus computed tomography demonstrated that the intraosseous branch of the ascending branch of the ACHA runs within the GT in a medial direction from its penetration point just along the lateral edge of the BG. Intraosseous accumulation of contrast within the GT supply occurs more toward the inferior aspect of the HH, and the anterior-superior and superior-medial aspect of the HH is not perfused. This region is a high-risk zone for avascular necrosis. CONCLUSION : The results of this study suggest that 7 variations for the course of the ACHA exist. These variations and the interruption of the intraosseous arterial network in the GT with surgery and suture anchor placement result in a high-risk zone in the superomedial aspect of the humeral head overlapping with the area where early aseptic necrosis is identified.The National Research Foundation, South Africahttp://www.elsevier.com/locate/jseshj2020AnatomyOral Pathology and Oral BiologyOrthopaedic Surger

The determination of safe zones for arthroscopic portal placement into the posterior knee by mapping the courses of neurovascular structures in relation to bony landmarks

PURPOSE : Minimally invasive surgery in the posterior knee is high risk for iatrogenic injury to popliteal neurovascular neurovasculature structures. This study aimed to use reliable landmarks to define safe zones for arthroscopic portal placement into the posterior knee. METHODS : Distances were measured between bony landmarks and neurovascular structures within the popliteal fossa using 45 formalin-embalmed cadavers: small saphenous vein (SSV), medial (MCSN) and lateral (LCSN) cutaneous sural nerves, tibial nerve (TN), common fibular nerve (CFN), popliteal vein (PV) and artery (PA). The structures were measured in relation to medial (MEF) and lateral (LEF) femoral epicondyle, medial (MCT) and lateral (LCT) tibial condyle and the midpoint between the landmarks. RESULTS : The mean distance (mm) between MEF and structures was, male and female, respectively: SSV 37.6 + 12.5, 37.9 + 8.2; MCSN 39.2 + 14, 38.8 + 10.1; TN 39.4 + 10.2, 38.0 + 8.1; PV 38.4 + 12.9, 32.8 + 5.6; PA 38.4 + 12.1, 34.6 + 4.9. At midpoint and MCT all structures medialized between 5 and 28%. The mean distance between LEF and structures was, male and female, respectively: CFN 13.4 + 8.2, 8.4 + 9.1; LCSN 24.9 + 7.3, 18.4 + 10.4. At midpoint and LCT the CFN lateralized by 37–42% and the LCSN medialized by 8–9%. CONCLUSIONS : Results suggest posteromedial portal placement can be safely established < 20 mm from the medial femoral epicondyle, tibial condyle or the midpoint between the two landmarks. Posterolateral portal placement is of higher risk, and entry point is 18 mm from the lateral femoral epicondyle, tibial condyle or the midpoint between the two landmarks in males and 12 mm in females. These landmarks will allow safe portal placement in 99% of cases.https://link.springer.com/journal/5902022-01-03hj2021Anatom

A state-wide education program on opioid use disorder: influential community members\u27 knowledge, beliefs, and opportunities for coalition development

Background: Deep South states, particularly Alabama, experience disproportionately higher opioid prescribing rates versus national rates. Considering limited opioid use disorder (OUD) providers in this region, collaborative efforts between non-healthcare professionals is critical in mitigating overdose mortality. The Alabama Opioid Training Institute (OTI) was created in 2019 to empower community members to take action in combatting OUD in local regions. The OTI included: 1) eight full-day in-person conferences; and 2) an interactive mobile-enabled website ( https://alabamaoti.org ). This study assessed the impact of the OTI on influential community members\u27 knowledge, abilities, concerns, readiness, and intended actions regarding OUD and opioid overdose mitigation. Methods: A one-group prospective cohort design was utilized. Alabama community leaders were purposively recruited via email, billboards, television, and social media advertisements. Outcome measures were assessed via online survey at baseline and post-conference, including: OUD knowledge (percent correct); abilities, concerns, and readiness regarding overdose management (7-point Likert-type scale, 1 = strongly disagree to 7 = strongly agree); and actions/intended actions over the past/next 6 months (8-item index from 0 to 100% of the time). Conference satisfaction was also assessed. Changes were analyzed using McNemar or Marginal Homogeneity tests for categorical variables and two-sided paired t-tests for continuous variables (alpha = 0.05). Results: Overall, 413 influential community members participated, most of whom were social workers (25.7%), female (86.4%), and White (65.7%). Community members\u27 OUD knowledge increased from mean [SD] 71.00% [13.32] pre-conference to 83.75% [9.91] post-conference (p \u3c 0.001). Compared to pre-conference, mean [SD] ability scale scores increased (3.72 [1.55] to 5.15 [1.11], p \u3c 0.001) and concerns decreased (3.19 [1.30] to 2.64 [1.17], p \u3c 0.001) post-conference. Readiness was unchanged post-conference. Attendees\u27 intended OUD-mitigating actions in the next 6 months exceeded their self-reported actions in the past 6 months, and 92% recommended the OTI to others. Conclusions: The Alabama OTI improved community leaders\u27 knowledge, abilities, and concerns regarding OUD management. Similar programs combining live education and interactive web-based platforms can be replicated in other states

Inter- and intraclass correlations for three standard foot radiographic measurements for plantar surface angles. Which measure is most reliable?

Background: The purpose of this study was to evaluate the reliability and reproducibility of three commonly used radiographic measures for plantar surface angles. Methods: The calcaneal angle (CA), calcaneal pitch angle (CPA), and length-height index (LHI) was measured by three independent examiners on two occasions on lateral foot radiographs. Intra- and inter-rater correlations were calculated using a general linear estimate model and post-hoc tests for repeated measures. Bland–Altman's plots with limits of agreement were used for observer differences in scores. Results: The intra-class correlations for the CA ranged from 0.91 to 0.94, for the CPA from 0.93 to 0.98, and for the LHI from 0.96 to 0.97. The inter-class correlations were 0.80 for CA, 0.83 for CPA and 0.93 for LHI. Conclusions: The results of this study strongly suggest that the length-height index was the most consistent and reliable measure for arch height. Level of evidence: Diagnostic Level II, validity

The anatomical relationship of the common peroneal nerve to the proximal fibula and its clinical significance when performing fibular-based posterolateral reconstructions

PURPOSE : The common peroneal nerve (CPN) can be injured during fibular-based posterolateral reconstructions due to its close relationship to the neck of the fibula. Therefore, the purpose of this study was to observe the course of the CPN and its branches around the fibular head and neck and quantify the position in relation to relevant bony landmarks and observe the relation between tunnel drilling for posterolateral corner reconstruction and both the tunnel entry and exit at the proximal fibula and the CPN and its branches was observed. METHODS : In 101 (mean age = 70.6 ± 16 years) embalmed cadaver knees, the relationship between bony landmarks (tibial tuberosity, styloid process of fibula (APR)) and the CPN and its branches were established and 8 (M1–M8) distances from these landmarks measured; mean, SD and 95% CI were recorded. In 21 of these knees, a fibula tunnel was drilled as in PLC reconstruction and the association of the CPN and its branches to the tunnel entry and exit were judged by two independent observers. Fisher’s exact test of independence was used to determine significant differences between genders. Tunnel intersection was analysed in a binary yes/no fashion and was described in frequencies and percentages. RESULTS : The mean distance from the APR to where the CPN reaches the fibula neck (M1) was 31.4 ± 8.9 mm (CI:29.8–33.0); from the apex of the styloid process (APR) to where the CPN passes posterior to the broadest point of the fibular head (M3) was 21.7 ± 12.6 mm (CI:19.4–24.0); from the apex of the APR to the most proximal point of the CPN/CPN first branch in the midline of the fibular head (M2) was 37.0 ± 6.7 mm (CI: 35.4–37.7). Out of the 21 randomly selected knees for drilling, the first branch of the CPN was damaged at the tunnel entry point in 7 (33%), and in 5 knees (24%), the CPN was damaged at the tunnel exit. In one knee, at both the tunnel entry and exit, the first branch of the CPN and the CPN were intersected, respectively. CONCLUSION : The results of this study strongly suggest that the CPN is at risk when drilling the fibula tunnel performing fibula-based posterolateral corner reconstructions. The total injury rate was 57% with a 33% incidence of injury to the first branch of the nerve at the tunnel entry and 24% to the CPN at the tunnel exit. CLINICAL RELEVANCE : Due to the high incidence of injury, percutaneous placement of guide pins and tunnel drilling is not recommended. The nerve should be visualized and protected by either a traditional open approach or minimally invasive techniques. With a minimally invasive approach, the nerve should be identified at the fibula neck and then followed ante- and retrograde.https://link.springer.com/journal/402hj2022Anatom

Transcoracoid drilling for coracoclavicular ligament reconstructions in patients with acromioclavicular joint dislocations result in eccentric tunnels

PURPOSE : To determine the location of coracoid inferior tunnel exit with superior-based tunnel drilling and coracoid superior tunnel exit with inferior-based tunnel drilling. METHODS : Fifty-two cadaveric embalmed shoulders (mean age 79 years, range 58-96 years) were used. A transcoracoid tunnel was drilled at the center of the base. Twenty-six shoulders were used for the superior-to-inferior tunnel drilling approach and 26 shoulders for the inferior-to-superior tunnel drilling approach. The distances to the margins of the coracoid process, from both the entry and exit points of the tunnel, were measured. Paired Student t-tests were used to compare the distance from the center of the tunnel and the medial and lateral coracoid border and the apex. RESULTS : The mean difference for the distances between superior entry and inferior exit from the apex was 3.65 ± 3.51 mm (P = .002); 1.57 ± 2.27 mm for the lateral border (P = .40) and 5.53 ± 3.45 mm for the medial border (P = .001). The mean difference for the distances between inferior entry and superior exit from the apex was 16.95 ± 3.11 mm (P = .0001); 6.51 ± 3.2 mm for the lateral border (P = .40) and 1.03 ± 2.32 mm for the medial border (P = .045). Inferior-to-superior drilling resulted in 4 (15%) cortical breaks. CONCLUSIONS : Both superior-to-inferior and inferior-to-superior tunnel drilling directed the tunnel from a more anterior and medial entry to a posterior–lateral exit. Superior-to-inferior drilling resulted in a more posteriorly angled tunnel. When using a 5-mm reamer and inferior-to-superior tunnel drilling, cortical breaks were observed at the inferior and medial margin of the tunnel exit. CLINICAL RELEVANCE : Arthroscopic-assisted acromioclavicular joint reconstruction using conventional jigs may result in an eccentric coracoid tunnel, possibly introducing stress risers and fractures. To avoid cortical breaks and eccentric tunnel placement, open drilling from superior-to-inferior with a superiorly centered guide pin and arthroscopic visualization of a centered inferior exit should be considered.https://www.sciencedirect.com/journal/arthroscopy-sports-medicine-and-rehabilitationhj2023Anatom

The posterior horn of the medial and lateral meniscus both reduce the effective posterior tibial slope : a radiographic MRI study

PURPOSE : The purpose of this study was to quantify the posterior horn meniscal slope and determine its contribution to the reduction in posterior tibial slope. METHODS : Patients aged between 16 and 60 years and had intact menisci with no evidence of previous injury or surgery were included. Patients with radiological evidence of osteoarthritis Grade II–IV, any acute or chronic meniscus injuries, fractures, and ligamentous injuries were excluded. The posterior bony slope (PTS) and the meniscus slope (MS) of the posterior horns were measured at 25, 50, and 75% from the medial and lateral borders of the tibial plateau. RESULTS : 325 MR images (mean age 37.1 ± 10.9 years) were included. There were 194 males and 131 females, with 162 left and 163 right knees. The PTS in the medial compartment ranged from (−) 2.8° to 3.7° and from (−) 1.3° to 1.9° in the lateral compartment (p = 0.0001). The MS in the medial compartment ranged from 27.4° to 28.2°, and from 27.8° to 28.7° in the lateral compartment (p > 0.05). The differences between the medial and lateral knee compartment were statistically significant. At the 25% interval the p level was 0.037, at 50% p = 0.00001, and at 75% p = 0.0001. There were no significant between gender differences. CONCLUSIONS : The results of this study demonstrated a significant reduction in posterior tibial bone slope by the posterior horns of both the medial and lateral meniscus, from a mean of (−) 1° to 2° to a more horizontal anterior slope. The posterior bone slope was larger in the medial compartment by 1°, resulting in a smaller slope reduction in the lateral compartment.https://link.springer.com/journal/276hj2022AnatomyOrthopaedic Surger

A posteromedial portal allows access to the posteromedial knee, while a posterolateral portal risks common fibular nerve injury : a cadaveric analysis

To investigate the safety and accessibility of direct posterior medial and lateral portals into the knee. This study was a controlled laboratory study that comprised a sample of 95 formalin-embalmed cadaveric knees and 9 fresh-frozen knees. Cannulas were inserted into the knees, 16 mm from the vertical plane between the medial epicondyle of the femur and the medial condyle of the tibia, and 8 (females) and 14 mm (males) from the vertical plane connecting the lateral femoral epicondyle and lateral tibial condyle. Landmarks were identified in full extension, and cannula insertion was completed with the formalin-embalmed knees in full extension and the fresh-frozen knees in 90 degrees of flexion. The posterior aspects of the knees were dissected from superficial to deep to assess potential damage caused by the cannula insertion. The incidence of neurovascular damage was 9.6% (n = 10): 0.96% for the medial cannula and 8.7% for the lateral cannula. The medial cannula damaged 1 small saphenous vein (SSV). The lateral cannula damaged 1 SSV, 7 common fibular nerves (CFNs), and both the CFN and lateral cutaneous sural nerve in 1 specimen. All incidences of damage occurred in formalin-embalmed knees. The posterior horns of the menisci were accessible in all specimens. A direct posterior portal into the knee with reference to the medial bony landmarks of the knee proved safe in 99% of the cadaveric sample and allowed access to the posterior horn of the medial meniscus. A direct posterior portal with reference to the lateral bony landmarks demonstrated a higher risk of neurovascular damage in the embalmed sample but no damage in the fresh-frozen sample. Given the severe consequences of common fibular nerve injury, recommending this approach at this stage is not advisable. Direct posterior arthroscopy portals are understudied but may allow safe visualization of the posterior knee compartments and may also assist to manage repair of ramp lesions and posterior meniscus pathology

The mechanical properties of fresh versus fresh/frozen and preserved (Thiel and Formalin) long head of biceps tendons : a cadaveric investigation

Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n = 7) with fresh-frozen (n = 8), formalin embalmed (n = 15), and Thiel-preserved (n = 6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12 N/mm2 in the fresh group, increasing to 40.1 N/mm2 in the fresh-frozen group, 50.3 N/mm2 in the formalin group, and 52 N/mm2 in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6 MPa), to fresh-frozen (55.3 MPa), to Thiel (82.5 MPa), with the stiffest being formalin (510.6 MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Young’s modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.http://www.elsevier.com/locate/aanat2019-06-04hj2018AnatomyOrthopaedic Surger