Ultrasound imaging of tissue overlying the ischial tuberosity: Does patient position matter?

BACKGROUND: Deep Tissue Pressure Injury (DTI) occurs in the tissues underlying the skin that may not have visible signs of skin breakdown and may be detected by ultrasound. The optimal position for ischial region ultrasound image acquisition to facilitate assessment of the tissue proximal to the ischias not been determined. OBJECTIVE: To evaluate the mean difference in geometric and grey scale measures of tissues overlying the ischial tuberosity (IT) acquired from ultrasound images in supine and lateral recumbent simulated sitting positions from adults with spinal cord impairment (SCI). METHODS: Nine individuals (3 acute and 6 chronic) with SCI or disease with neurological level of injury C4-T12 and AIS A-D and who used a wheelchair for mobility were recruited and underwent ultrasound acquisition in the supine and lateral recumbent positions. One participant was imaged twice on a separate day. Three images from the left (n = 8) and right (n = 2) IT were scanned using a 6 - 18 MHz linear ultrasound probe (Acuson S2000) with participants' hips and knees flexed to 90° in both the supine and lateral recumbent positions using a single rater protocol. MATLAB Image Processing Toolbox with a customized script was used to obtain mean and maximal thickness, echogenicity and contrast of skin, subcutaneous tissue and muscle. Wilcoxon Signed Rank Test and Bland Altman analysis was used to determine if there were differences between the two image acquisition positions and to construct limits of agreement. RESULTS: Thickness and contrast measures were similar in the supine and lateral recumbent positions (p > 0.05). Muscle echogenicity was lower in the supine position (p = 0.04). CONCLUSION: There is agreement in geometric and grey scale measures of tissues over the IT between the supine and lateral recumbent positions with the exception of muscle echogenicity, which was lower in the supine position. Since DTI is thought to originate in the muscle and echogenicity plays in a role in abnormal tissue imaging diagnosis, further studies are recommended to determine the impact of body position on muscle echogenicity prior to being used in prospective studies.

Wheelchair Tilt-in-Space and Recline Functions: Influence on Sitting Interface Pressure and Ischial Blood Flow in an Elderly Population.

Pressure ulcers (PUs) result from localised injury to the skin and underlying tissue and usually occur over a bony prominence as a result of pressure, often in combination with shear forces. Both pressure magnitude and duration are thought to be key risk factors in the occurrence of PUs, thus exposing wheelchair-bound subjects to high risk of PU development. As a result, wheelchairs that incorporate tilt-in-space and recline functions are routinely prescribed to redistribute pressure away from their ischial tuberosities. The goal of this study was to analyse the role of full-body tilt and recline angles in governing sitting interface pressure and blood circulation parameters in elderly subjects and thereby investigate the efficacy of tilt-in-space wheelchairs for aiding pressure relief activity. Sitting interface pressure and ischial blood flow parameters were examined in 20 healthy elderly subjects while seated in a tilt-in-space and recline wheelchair. Five different angles of seat tilt (5°, 15°, 25°, 35°, and 45°) were assessed in combination with three different angles of backrest recline (5°, 15°, and 30°). The results of the study show that when compared to the upright reference posture, every position (except 15°T/5°R) resulted in a significant decrease in sitting interface pressure. Ischial blood flow also showed significant increases at four different positions (45°T/15°R, 15°T/30°R, 35°T/30°R, and 45°T/30°R) but only at larger tilt-in-space and recline angles. The results therefore suggest that small tilt-in-space and recline angles are indeed able to reduce sitting interface pressures, whereas changes in ischial blood flow only occur at larger angles. In the literature, cell deformation is thought to be dominant over tissue ischemia in the development of tissue necrosis and PUs. Therefore, together with our findings it can be concluded that frequently undertaking small adjustments in tilt-in-space and recline angle might be important for preventing cell deformation and any associated cell necrosis. Larger angles of tilt-in-space and recline seem to support blood flow returning to the tissues, which is likely to play a positive role in healing damaged tissue.

Vascular anatomical relationships of the retropubic space and the sacrospinous ligament, using three-dimensional imaging.

INTRODUCTION AND HYPOTHESIS: Pelvic anatomy is complex and intimate knowledge of variabilities in anatomical relationships is critical for surgeons to safely perform surgical procedures. Three-dimensional Imaging provides the opportunity to analyze undisturbed anatomical relationships. The authors hypothesized that three-dimensional models created from pelvic computed tomography angiograms could be used to obtain vascular anatomical measurements, and that the measurements obtained from three-dimensional models would be similar to those from cadaver studies. METHODS: We included all pelvic computed tomography angiograms that were acquired in female patients older than 18 years at our institution within the previous 5 years. Three-dimensional models were created using the Invivo5 software based on the Digital Imaging and Communications in Medicine files. Structures of interest were virtually dissected and measured replicating previous cadaver studies. Statistical analysis of demographics and measurements was performed. RESULTS: The final analysis included 87 studies. The average age of the subjects was 66.9 years and their average BMI was 26.1 kg/m2. Of the 87 subjects, 12.6% had a history of hysterectomy, 2.3% a history of a continence procedure, and 1.1% a history of a prolapse procedure. The range of distance between the ischial spine and the pudendal artery was 3-17 mm. The closest vessels to the lower edge of the symphysis pubis were the obturator vessels. The aberrant corona mortis vessel was present in 27.9% of the subjects. Prior hysterectomy was associated with changes in the measurements of the obturator arteries with minimal changes in other measurements. CONCLUSIONS: Our results indicate that this technology provides similar measurements to those found in previous unembalmed cadaver studies. This technology offers a great opportunity to study anatomical relationships in a native undisturbed state.

Benign Vascular Malformation at the Ischial Tuberosity.

A 31-year-old female student was referred to physical therapy with a chief complaint of proximal, posterior left thigh pain that began insidiously 12 months prior, and progressively worsened while training for a half-marathon. A mobile, soft mass was identified just inferior to the ischial tuberosity that was tender and painful to palpation, recreating the patient's chief complaint. Radiographic findings were negative for a suspected avulsion fracture at the ischial tuberosity. Therefore, the physician performed musculoskeletal ultrasonography, which revealed a superficial hypoechoic mass with vascular flow. Magnetic resonance imaging and a subsequent biopsy led to the diagnosis of a benign vascular malformation. J Orthop Sports Phys Ther 2016;46(7):607. doi:10.2519/jospt.2016.0410.

Anatomical Variations of the Blood Vascular System in Veterinary Medicine. The Internal Iliac Artery of the Dog. Part Two.

The aim of this study was to investigate the variability of the internal pudendal artery. Two hundred and thirty-two pelvic halves from 116 adult dogs were examined. Twenty-six anatomical variations were found, thirteen occurring in more than 5% of the dogs. Anatomical variations were grouped in relation to the origin of the prostatic/vaginal arteries, middle rectal artery, urethral artery, ventral perineal and caudal rectal arteries. The chi-squared test was used to analyse differences in sex, side of the body, profile and size, and the results were considered statistically significant when P ≤ 0.05. An identical vascular pattern in both hemipelvises was found for most of the anatomical variations described.

Effects of wheelchair cushions and pressure relief maneuvers on ischial interface pressure and blood flow in people with spinal cord injury.

OBJECTIVE: To investigate the effectiveness and interactions of 2 methods of pressure ulcer prevention, wheelchair cushions and pressure relief maneuvers, on interface pressure (IP) and blood flow of the buttocks. DESIGN: Within-subject repeated measures. SETTING: Rehabilitation center. PARTICIPANTS: Wheelchair users with a spinal cord injury or disorder (N=17). INTERVENTIONS: Participants performed 3 forward leans and 2 sideward leans with different degrees of lean while seated on each of 3 different wheelchair cushions. MAIN OUTCOME MEASURES: IP measured with a custom sensor and blood flow measured with laser Doppler flowmetry were collected at the ischial tuberosity. RESULTS: Pressure relief maneuvers had a significant main effect on the ischial IP (P<.001); all maneuvers except for the small frontward lean resulted in a significant reduction in IP compared with upright sitting. Blood flow significantly varied across postures (P<.001) with flow during upright sitting and small forward leans being significantly lower than during the full and intermediate leans in both the forward and sideward directions. CONCLUSIONS: The results of the study highlight the importance of positioning wheelchair users in a manner that facilitates in-seat movement. Regardless of the cushion being used, the pressure relief maneuvers resulted in very large reductions in IPs and significant increases in buttock blood flow. Only the small frontward lean was shown to be ineffective in reducing pressure or increasing blood flow. Because these pressure relief maneuvers involved postural changes that can occur during functional activities, these pressure relief maneuvers can become a part of volitional pressure relief and functional weight shifts. Therefore, clinical instruction should cover both as a means to impart sitting behaviors that may lead to better tissue health.

Physical activity and transcutaneous oxygen pressure in men with spinal cord injury.

This pilot study proposed a method for assessing the status of vascular flow measured by transcutaneous oxygen pressure (TcPO2) in the area of the ischium in people with spinal cord injury (SCI). In a sample of 38 men (two groups: 12 physically active and 26 sedentary) with thoracic SCI, the distribution of the physiological response of the tissues under load during sitting was assessed through analysis of ischium TcPO2 values obtained by an oximeter. TcPO2 baseline, recovery time of TcPO2 after sitting (Trec), the percentage of TcPO2 (%TcPO2) of maximum pressure TcPO2, and mechanic maximal pressure (Pmax) were evaluated. Trec in the physically active group was significantly lower (p < 0.05) than in the sedentary group. Likewise, significant differences in %TcPO2 between groups (p < 0.05) were also found. We concluded that the physiological response of the tissues under an individual with SCI's own weight resulting from prolonged sitting is better in those who are physically active.

Is the obturator artery safe when performing ischial osteotomy during periacetabular osteotomy?

The purposes of this study were (1) to evaluate the actual distance between the obturator artery and the ischial osteotomy site when performing periacetabular osteotomy via an anterior approach and (2) to determine a safe method to avoid injuring the obturator artery during this procedure. Twenty-nine hemipelves from cadavers were used in this study. The mean distance between the obturator artery and the ischial osteotomy site was 35.6 ± 7.5 mm and always exceeded 20 mm. Therefore, the procedure can be performed safely when a chisel blade of 20 mm or shorter is used.

Morphological architecture and distribution of blood capillaries and elastic fibres in the human skin.

This study was undertaken to clarify the morphological features in the blood capillary and elastic fibre distribution of the human skin in terms of susceptibility to pressure sore development. Skin tissues were obtained from bony areas: the sacrum and ischial tuberosity and non-bony area: the centre of the gluteus maximus of 5 aged subjects post mortem for examination using light and scanning electron microscopy. It was observed that the sacral skin had finger-like papillae and underneath the blood capillary loops were most numerous. In the ischial skin the dermal papillae consisted of a combination of finger-like and trapezoid shapes having moderate density of blood capillaries. In contrast, the dermal papillae in the gluteal skin were almost flat, so that the blood capillaries were scattered. The size of elastic bundles in the papillary layer of the sacral, ischial and gluteal skin ranged from 2 to 3 microns, 5 to 10 microns, and 3 to 5 microns, respectively. The elastic fibres were densely distributed in the ischial skin while less so in the sacral skin.

[A case of the persistent sciatic artery].

During the dissecting practice of students at Gifu University School of Medicine in 1989, a rare developmental anomaly showing the sciatic artery was found in the left lower limb of a cadaver of 88-year-old Japanese female. The left sciatic artery (5 mm in diameter) arose from the internal iliac artery and appeared at the buttock between the piriformis and superior gemellus muscles through foramen infrapiriforme. The femoral artery (6 mm in diameter) of the left lower limb was normal in distribution and belonged to the type III by Adachi's classification (1928). The terminal vessel of the femoral artery was joined to the sciatic artery at the popliteal fossa.

[Obturator shunting in suppuration of vascular prostheses]. / Obturatornoe shuntirovanie pri nagnoenii sosudistykh protezov.

An experience with using obturatory shunts in 10 patients with suppurations of vascular prostheses after reconstructive operations on the aorto-iliac segment for its occlusive lesion is presented. The authors have come to a conclusion that extra-anatomical shunting through the closing inlet of the pelvis when combined with resection or removal of the infected vascular prosthesis, local and general antibacterial therapy is an effective method of treatment of the pathology in question. The modified method of shunting facilitates performing the operation in most critical patients. Good results were obtained in 7 of 10 patients operated upon. Two patients died. The amputation of the extremity was fulfilled in 1 patient.

Soft tissue augmentation as a method of reducing the liability to pressure sores in spinal injured patients.

The development of a procedure designed to reduce the liability to pressure sores over bony prominences is described. This employs the properties of a particular type of carbon fibre pad implanted surgically over the bony prominence. The mechanical response of the pad to loading has been examined. The host tissue response to the pad involves penetration of the interstices between the carbon fibres with organised fibrous tissue. The host-tissue--carbon fibre pad complex has been found to be highly vascular. An 'ischiobarograph' has been developed and used in order to evaluate the alteration in pressure profile produced by the presence of the implanted prosthesis (the patient being in a sitting position).

Aneurysmal bone cyst of the ischium.

The treatment of a patient with an aneurysmal bone cyst involving the pelvis by selective arterial embolism is described. After one year pain relief is complete and radiologically the lesion is healing with increased density of the cyst wall and intracystic trabecular bone formation.

[Ischio-popliteal artery trunk, persistence of the axial artery]. / Tronc artériel ischio-poplité, persistance de l'artère axiale.

The authors studied two cases of persistent axial artery of the lower limb, a classic but exceptional variation (42 cases in the literature). It is well explained by embryology and is a recapitulation of anatomy in the animal series. By the systematic study of the literature, we can isolate four distinct types: Type I: Complete axial artery, normal femoral artery. Type II: Id., but incomplete femoral artery, with two subdivisions: II a: Femoral artery is present but incomplete. II b: Femoral artery is absent. Type III: Axial artery only in the proximal zone. Type IV: Axial artery only in the distal zone. In these two last types, the femoral artery is complete. The I, III and IV types correspond to organogenetic perturbation at the stage 21 of Streeter. The type II implies a more early disturbance, prior to stage 18.

Adjuvant arterial embolization in the treatment of benign primary bone tumors in children.

This report presents an initial clinical experience with arterial embolization as adjuvent therapy in the surgical treatment of selected benign primary bone tumors in childhood. Embolization was dramatically effective in 4 children with spinal or pelvic vascular tumors. This technique facilitated local surgical resection and/or curettage. No child had evidence of local recurrence. Three of the 4 children had spinal cord or nerve root compression resulting in various degrees of paralysis prior to surgery. All treated patients had complete recovery from their paralysis. There were no complications of embolization or surgery. The treatment of benign primary bone tumors of the spine and pelvis is immeasurably improved by the adjuvant arterial embolization procedure. The immediate surgical treatment of these difficult tumors now becomes feasible with the greatly diminished blood flow resulting from embolization.

[The anatomic and radiologic picture of the acetabulum (author's transl)]. / Zum anatomischen und röntgenologischen Bild der Hüftpfanne

The basic shape of the facies lunata shows at the inner margin of each of the three participating bones a dell into which the floor of the acetabulum progresses. These dells originate in nutritive vessels which enter the bone and claim this place. There always are groups of vessels and wide channels which may be visible on radiographs. The so far unexplained picture of a vascular canal in the roof of the acetabulum corresponds to the canal leading into the body of the ilium. Due to its position there is often restructuring leading to filling or covering of the canal. The entrance to this canal is shown as a gap in the arc of the acetabular cavity which would have to be added to that of the "tear figure" known so far. The closed arc, as always drawn, reults only when this entry has been filled up.