The posterior epidural ligament in the thoracic region: a cadaveric and histological study.

The existence of posterior epidural ligaments (PEL) has been established in the lumbar region, but they have hitherto not been shown to exist in the thoracic vertebral column. Their identification is of clinical significance in respect to incidental durotomy and the circulation of cerebrospinal fluid (CSF). Fourteen thoracic spine sections were dissected by cutting through the intervertebral disc and separating the ligamentum flavum from the vertebra above. The dural sheath was gently retracted anteriorly to identify macroscopic connections between the ligamentum flavum and the dura. Macroscopic connections observed were dissected out, retaining some dural sheath and ligamentum flavum. Histological staining with haematoxylin and eosin and Miller's elastin stain was used to investigate cellular connections. Thoracic PELs were positively identified in 5 of the 14 cadavers (35.7%). Histology showed similarities between the thoracic and lumbar PELs. Fifteen separate PELs were identified within these five thoracic sections. The thoracic PEL has sufficient tensile strength to present a risk to the integrity of the dural sheath during surgery, and surgeons should be aware of these connections when operating on the thoracic spine. PELs may also contribute to the circulation of CSF in the spinal subarachnoid space.

The innominate tubercle of the femur: Application to anterior surgical approaches to the hip.

There has recently been an increase in popularity of the direct anterior approach (DAA) hip arthroplasty, due to the muscle sparing nature of its interneural intervals, with the innominate tubercle being used as a lateral reference point for the femoral neck osteotomy. However, there is very little information in the literature on this rather enigmatic structure, with no evidence as to whether it is a consistent and reliable marker, or if it varies significantly in the population. In this study, data were gathered from 79 pairs of adult, post-medieval skeletal femora to investigate the effects of sex, age, femoral side, femoral length, femoral neck length, and femoral neck-shaft angle on the width, length, and height of the innominate tubercle. The sex, age, and date of death of the individuals had been recorded. Statistical analysis included canonical correlation and multivariate multiple regression. We found that there was no statistical significance or correlation between the width, length, or height of the tubercle with respect to any of the variables investigated. These results suggest that the innominate tubercle does not differ markedly between individuals in the Caucasian population, and, is therefore, a reliable landmark for femoral neck osteotomy during DAA hip arthroplasty. We present what we believe to be a definitive survey of the variability of the innominate tubercle in a Caucasian population. Clin. Anat. 30:578-584, 2017. © 2017 Wiley Periodicals, Inc.

Langer's axillary arch: a rare variant, and prevalence among Caucasians.

During the dissection of a 79-year-old Caucasian female cadaver, a variant of Langer's axillary arch was found unilaterally in the left axilla. While Langer's axillary arches are not uncommon, this particular variant, attaching to the biceps brachii, is much rarer with a reported prevalence of only 0.25%. The case reported here, however, is only the third example of a Langer's axillary arch that has been found in the last 14 years in the Dissecting Room at St. George's, University of London, giving it an overall prevalence of approximately 1.0% amongst a population of around 280 Caucasian cadavers, much lower than the reported frequency of 7%. Langer's axillary arches can be completely asymptomatic in life, but may also cause a variety of issues both clinically and surgically.

The effect of exercise on vastus medialis oblique muscle architecture: An ultrasound investigation.

The vastus medialis oblique (VMO) is thought to be implicated in patellofemoral pain (PFP), and weakness in this portion of the vastus medialis muscle may lead to PFP. Management includes physiotherapy to strengthen the VMO. Although this intervention has been shown to be effective, the effects on the architecture of the muscle have not been investigated. This study aims to determine the changes in VMO architecture following a program of strengthening exercises. Twenty-one male participants underwent an initial ultrasound scan to measure the fiber angle and the insertion level of the VMO on the patella. Each subject then undertook a 6-week quadriceps femoris strengthening program; the scan and measurements were then repeated. A significant increase in VMO fiber angle and insertion length was observed. Average fiber angle increased by 5.24°; average insertion length increased by 2.7 mm. There was found to be a significant negative correlation between the initial values and the degree of change. Pearson's coefficient of correlation for measurements of patella length taken before and after exercise was 0.921, indicating a high degree of reliability. There was a significant positive correlation between fiber angle change and declared level of compliance (R(2) = 0.796). The results reported here indicate that physiotherapy leads to a significant change in VMO morphology. Given the inverse correlation noted between initial architectural parameters and the degree of change, we suggest that patients who would benefit most from physiotherapy can be identified in clinic using a simple ultrasound technique. Clin. Anat. 29:752-758, 2016. © 2016 Wiley Periodicals, Inc.

Absent posterior interventricular artery.

During the dissection of the thorax of a 79-year-old Caucasian male cadaver, the posterior interventricular coronary artery was found to be completely absent. Congenital heart abnormalities are frequent but absent arteries are uncommon and when occurring are often associated with replacement vessels from the existing circulation, making complete absence rare. This condition may well have been asymptomatic in life, but such variations could have serious implications in patients with underlying heart pathology.

An investigation into the architecture of the vastus medialis oblique muscle in athletic and sedentary individuals: an in vivo ultrasound study.

There is thought to be a relationship between the vastus medialis oblique muscle (VMO) and patellofemoral pain syndrome (PFPS), a condition that has a high prevalence in young athletic individuals. Following a suggestion that there may be a link between the architecture of the VMO and an individual's activity level, the aim of this study was to determine any differences in two measurable parameters of the VMO between two populations with widely differing activity levels. The parameters measured were VMO fiber angle and insertion ratio, which is the proportion of the medial patellar border with VMO fibers inserting onto it (%). Eighty-two knees from 26 athletic volunteers and 15 sedentary volunteers (aged 20-28 years) were assessed using ultrasound. Activity level was defined using the Tegner scoring system. The mean VMO angle (°) for the athletic group was significantly higher than for the sedentary group at 67.8° and 53.6°, respectively. There was no significant difference in insertion ratio between the athletic group, 43.0%, and the sedentary group, 39.5%. This study found that greater VMO fiber angles were seen in individuals with higher activity levels, exerting a stronger medial stabilizing force on the patella. This has important implications for the treatment of PFPS, particularly in athletic patients, which frequently focus on VMO strengthening exercises.

Ultrasound investigation of vastus medialis oblique muscle architecture: an in vivo study.

There is thought to be a link between vastus medialis oblique (VMO) architecture and patellofemoral pain syndrome (PFPS). Historical data are largely derived from older populations, whereas PFPS commonly affects younger populations. The aim of this study was to gather data on VMO architecture in young asymptomatic adults, to provide baseline values for comparison with symptomatic sufferers. VMO maximum fiber angle and insertion ratio were measured with ultrasound. The insertion ratio represents the proportion (%) of the patella which has the muscle fibers attaching to its medial border. Eighty knees from 40 healthy young subjects (18 males, 22 females, and age 20-30) were assessed. Individual Tegner scores were recorded to assess participants' level of physical activity. Results were compared with data in the literature for PFPS sufferers and normal older individuals. Mean fiber angle and insertion ratio were 56.6° and 57.8%, respectively. There was no significant difference between age groups. The insertion ratio was higher among females (61.2% F:53.6% M). There was some evidence of increased fiber angle and decreased insertion ratio with increased Tegner score. There was some overlap in fiber angle between healthy knees in this study and values reported elsewhere for pathological knees. VMO fiber angle and insertion ratio are not age-related. The overlap in fiber angle values between healthy and pathological knees suggests that the cause of PFPS is multifactorial. An individual's VMO architecture may be affected by their physical activity level, which could have important implications for PFPS.

The posterior epidural ligaments: a cadaveric and histological investigation in the lumbar region.

Purpose. Incidental durotomy is a relatively common complication for patients undergoing posterior spinal surgery. Delineating anatomical variants in the posterior lumbar spinal canal is crucial in reducing future rates of incidental durotomy. Materials and Methods. The ligamentous attachments between the dura mater and ligamentum flavum in the lumbar region of 17 soft-fixed cadavers were investigated. The lumbar vertebral columns were removed, and cross-sectional dissection was performed at levels L1-S1. Anterior retraction of the dorsal dura mater identified attachments between the dorsal surface of the dura mater and the ligamentum flavum. Histological staining of the ligamentous attachments was carried out with hematoxylin and eosin (H&E) and elastic van Gieson (EVG). Results. Posterior epidural ligaments were present in 9 (52.9%) cadavers. Nine (9) separate ligaments were identified in these cadavers, with 3 (33.3%) at L3/L4, 5 (55.5%) at L4/L5, and 1 (11.1%) at L5/S1. Histology confirmed the presence of poorly differentiated collagen-based connective tissue, distinct from the normal anatomy. Conclusions. This study confirms the presence of multiple dorsomedial posterior epidural ligaments at the main sites for posterior spinal surgery (L3-S1). An intraoperative awareness of the variability of such connections may be an important step in reducing static rates of incidental durotomy.

The potential complications of open carpal tunnel release surgery to the ulnar neurovascular bundle and its branches: A cadaveric study.

This study investigated the ulnar artery and the ulnar nerve and its branches in the palm to assess how frequently they may be at risk of damage during open carpal tunnel release surgery. Twenty-one formalin-embalmed cadaveric hands were dissected, and the proximity of the ulnar neurovascular bundle to two different lines of incision, the 3rd and 4th interdigital web space axis and the ring finger axis, was assessed and compared. It was found that an incision in the latter (ring finger) axis put the ulnar artery at risk in 12 of 21 specimens, whereas an incision in the former axis (3rd/4th interdigital web space) put the ulnar artery at risk in only two specimens. In 15 hands at least one structure (the ulnar artery or a branch of the ulnar nerve) was at risk in the ring finger axis compared to only seven hands in the axis of the 3rd/4th interdigital web space. We conclude that the ulnar artery and branches of the ulnar nerve are at increased risk of damage with an incision in the axis of the ring finger. The importance of using a blunt dissection technique under direct vision during surgery to identify and preserve these structures and median nerve branches is emphasized.

Amniotic membrane grafts, "fresh" or frozen? A clinical and in vitro comparison.

BACKGROUND/AIMS: The use of "fresh" (hypothermically stored) and frozen amniotic membrane (AM) was compared in a patient with cicatricial pemphigoid with stem cell failure. The viability of both "fresh" and frozen AM epithelial cells was assessed after storage. METHODS: AM was stored at either +4 degrees C ("fresh") or at -80 degrees C (frozen). A "fresh" graft was applied to the cornea following superficial keratectomy. Subsequently, a further frozen graft was applied to the same eye. Viability of the stored AM epithelium was assessed by investigating membrane integrity and mitochondrial activity. RESULTS: In both cases the cornea re-epithelialised and visual acuity improved. Improvement, however, was not sustained. CONCLUSION: Although both procedures led to an improvement in visual acuity, "fresh" tissue performed no better than frozen in promoting re-epithelialisation. The authors suggest that logistical, safety, and cost considerations outweigh any benefits of using "fresh" as opposed to frozen graft material.

Bacterial contamination of amniotic membrane.

AIM: In the light of interest being shown in amniotic membrane grafts for use in ocular surgery, this study aims to identify the bacterial contaminants commonly found on placental membranes from both caesarean and vaginal deliveries. METHODS: Samples of placental membrane were taken following both elective caesarean and normal vaginal deliveries. Bacterial contaminants were identified. RESULTS: All samples were contaminated. A greater number of different species were recovered from the vaginal deliveries, including several which were actually or potentially pathogenic. CONCLUSION: There is a greater risk of contamination from pathogenic bacteria on placentas from vaginal deliveries. It is recommended that amnion for use in ocular surface procedures should be retrieved only from placentas following elective caesarean deliveries.