Diana M. Perriman

Validation of the flexible electrogoniometer for measuring thoracic kyphosis.

Study Design. Three experiments to validate the use of the flexible electrogoniometer (FEG) as a tool to measure thoracic kyphosis. Objective. To investigate the accuracy, test-retest reliability, and concurrent validity of the FEG as applied to the thoracic spine. Summary of Background Data. Thoracic kyphosis is commonly measured by the Cobb angle from lateral radiograph. Other less-invasive tools have been developed, but all yield only static measurements or are restricted to the laboratory. The FEG, which can record joint angles over time outside the laboratory, has been used to measure other joints but has not yet been validated for measurement of the thoracic spine. Methods. First, the FEG was bench-tested against a plurimeter for accuracy. Second, 12 subjects performed 7 functional activities 1 week apart to assess the test-retest reliability. Finally, to examine concurrent validity, 12 subjects underwent radiography in “upright” and “slumped” standing with the FEG attached to the skin over their thoracic spine. Three Cobb angles, which corresponded with the inner, mid, and outer margins, respectively, of the overlying FEG end blocks were compared with the FEG angles. Results. The correlation between the FEG and the plurimeter was excellent (r > 0.99, P < 0.0001), although some accuracy was lost at extremes of range. The mean correlation between the first and second measurements was very strong (intraclass correlation coefficient2,1 0.92, P < 0.0001; range, 0.89–0.95). The mid-Cobb angle showed the least absolute angular difference from, and was highly correlated with, the FEG angle (r = 0.81, P < 0.01). Conclusion. The FEG demonstrated excellent accuracy and test-retest reliability and correlated very well with the Cobb angle. The FEG measurement seemed to correspond most closely with the Cobb angle measured between the middle of the FEG end blocks.

Monitoring and Controlling Intramedullary Pressure Increase in Long Bone Instrumentation : A Study on Sheep

Intramedullary reamed nailing causes elevation in intramedullary pressure and extravazation of intramedullary contents into the venous blood system. This study investigated the effect of an intramedullary suction system, recently developed in our laboratory, on the pressure and fat extravazation in isolated bovine bone and a sheep model. During reaming, the pressure with and without suction was recorded at each step of the procedure. Hemodynamic parameters of mean arterial blood pressure, pulmonary artery pressure, pulmonary arterial CO2 (PaCO2), heart rate, and oxygen saturation were monitored. Blood and lung tissue samples were collected for the examination of medullary fat intravazation. The increases of intramedullary pressure were dramatically reduced in the suction group (p < 0.05) in both in vitro and in vivo experiments. PaCO2 was significantly lower in the suction group than nonsuction group (32 vs. 40 mmHg, respectively, p = 0.02), while oxygen saturation was higher in the suction group (99 vs. 91 mmHg, respectively, p = 0.009). Histological data revealed a significant higher count of fat emboli in sheep lung tissue in the nonsuction group. Total lipids in lung specimens was lower in the suction group (7.6 mg/g tissue) than in the nonsuction group (13.6 mg/g, p = 0.04). The suction system appears to control the surge in intramedullary pressure and therefore prevent fat embolism.

Standing or supine x-rays after total hip replacement - when is the safe zone not safe?

An acetabular prosthesis orientated outside the ‘safe zone’ is one of the key contributing factors in increasing complications after total hip replacement (THR). Although acetabular orientation is routinely assessed using supine x-rays, standing x-rays have been proposed because a change in body position alters pelvic tilt and therefore acetabular orientation. This study aimed to assess whether acetabular components orientated within the ‘safe zone’ in supine can also be outside the ‘safe zone’ in standing. Thirty patients (12M, 18F) had lateral and antero-posterior pelvic x-rays taken in standing and supine positions six weeks post THR. Pelvic tilt and acetabular orientation (anteversion and inclination) were measured and compared with respect to the limits of the ‘safe zone’. In standing, the pelvis was relatively posteriorly tilted and both acetabular anteversion and inclination increased (p<0.0001). In 16 patients the acetabulum was orientated within the ‘safe zone’ in supine but outside the ‘safe zone’ in standing. Patients were significantly more likely to be outside the ‘safe zone’ in standing than when supine (p<0.0001).

Thoracic Hyperkyphosis: A Survey of Australian Physiotherapists

BACKGROUND Age-related thoracic hyperkyphosis can lead to poor health outcomes including pain and dysfunction. Physiotherapists are fundamentally involved in the assessment and treatment of this problem but there is no published data that details assessment and treatment strategies or the attitudes of practitioners with respect to hyperkyphosis. PURPOSE The purpose of the study is to ascertain current physiotherapy practice for, and attitudes to, the assessment and treatment of thoracic hyperkyphosis in Australia. METHOD A stratified random sample (N = 468) of Australian physiotherapists in all states and territories working in hospitals, outpatient clinics and community clinics were sent an anonymous cross-sectional postal survey. The survey had six sections identifying clinical profile, prevalence, measurement strategy, treatment frequency, treatment strategy and evidence source. RESULTS A response rate of 47% with anonymity preserved was achieved. The majority of respondents had a musculoskeletal practice profile (75%). Seventy-eight per cent encountered hyperkyphosis at least weekly, and three treatment sessions were most commonly given (35%). Visual inspection was almost universally used to assess the degree of hyperkyphosis (98%), and for 64% it was their only measurement tool. Postural re-education was the most common treatment strategy (90%) but the range of treatments reported was diverse. The primary source of evidence used by the majority of respondents was their undergraduate education, and there was concern expressed that physiotherapists lack good evidence upon which to make therapeutic decisions about hyperkyphosis. CONCLUSIONS Thoracic hyperkyphosis is commonly encountered by physiotherapists. Measurement of treatment efficacy is highly subjective, and the treatment modalities employed are diverse. Many physiotherapists based their management of hyperkyphosis on their undergraduate education alone.

Magnetic resonance imaging atlas of the cervical spine musculature.

The anatomy of the cervical spine musculature visible on magnetic resonance (MR) images is poorly described in the literature. However, the correct identification of individual muscles is clinically important because certain conditions of the cervical spine, for example whiplash associated disorders, idiopathic neck pain, cervical nerve root avulsion and cervical spondylotic myelopathy, are associated with different morphological changes in specific muscles visible on MR images. Knowledge of the precise structure of different cervical spine muscles is crucial when comparisons with the contralateral side or with normal are required for accurate description of imaging pathology, management and assessment of treatment efficacy. However, learning the intricate arrangement of 27 muscles is challenging. A multi‐level cross‐sectional depiction combined with three‐dimensional reconstructions could facilitate the understanding of this anatomically complex area. This paper presents a comprehensive series of labeled axial MR images from one individual and serves as a reference atlas of the cervical spine musculature to guide clinicians, researchers, and anatomists in the accurate identification of these muscles on MR imaging. Clin. Anat. 29:643–659, 2016.

An In Vivo Comparison of the Orientation of the Transverse Acetabular Ligament and the Acetabulum

Aligning the acetabular component with the Transverse Acetabular Ligament (TAL) to ensure optimal anteversion has been reported to reduce dislocation rates. However, to our knowledge in vivo measurement of the TAL angle has not yet been reported in a large cohort of normal hips. CT scans of 218 normal hips were analyzed. The TAL and four acetabular rim anteversion angles were measured (superiorly to inferiorly) relative to the anterior pelvic plane. The mean TAL anteversion angle was 20.5° ± 7.0°, and the acetabular rim angles from superior to inferior were 11.0° ± 12.9°, 19.9° ± 8.8°, 20.9° ± 6.2° and 25.1° ± 6.2° respectively. Both the TAL and the acetabular rim were significantly more anteverted in females than in males. The TAL anteversion angle was comparable to the predominant orientation (central rim section) of the native acetabulum while the superior acetabulum was comparatively retroverted and the inferior was relatively more anteverted.

Contrast agent comparison for three-dimensional micro-CT angiography: A cadaveric study

Barium sulfate and lead oxide contrast media are frequently used for cadaver-based angiography studies. These contrast media have not previously been compared to determine which is optimal for the visualisation and measurement of blood vessels. In this study, the lower limb vessels of 16 embalmed Wistar rats, and four sets of cannulae of known diameter, were injected with one of three different contrast agents (barium sulfate and resin, barium sulfate and gelatin, and lead oxide combined with milk powder). All were then scanned using micro-computed tomography (CT) angiography and 3-D reconstructions generated. The number of branching generations of the rat lower limb vessels were counted and compared between the contrast agents using ANOVA. The diameter of the contrast-filled cannulae, were measured and used to calculate the accuracy of the measurements by comparing the bias and variance of the estimates. Intra- and inter-observer reliability were calculated using intra-class correlation coefficients. There was no significant difference (mean difference [MD] 0.05; MD 95% confidence interval [CI] -0.83 to 0.93) between the number of branching generations for barium sulfate-resin and lead oxide-milk powder. Barium sulfate-resin demonstrated less bias and less variance of the estimates (MD 0.03; standard deviation [SD] 1.96 mm) compared to lead oxide-milk powder (MD 0.11; SD 1.96 mm) for measurements of contrast-filled cannulae scanned at high resolution. Barium sulfate-resin proved to be more accurate than lead oxide-milk powder for high resolution micro-CT scans and is preferred due to its non-toxicity. This technique could be applied to any embalmed specimen model. Copyright

Supervised or Unsupervised Rehabilitation After Total Hip Replacement Provides Similar Improvements for Patients: A Randomized Controlled Trial

OBJECTIVE To determine whether patients do better with unsupervised (home-based) physiotherapy or in an outpatient setting. SETTING Acute care public hospital in the region, supporting a population of ∼540,000. DESIGN Single-blind randomized controlled trial. PARTICIPANTS Adult patients (N=98) after unilateral elective total hip replacement (THR) were randomly assigned to a supervised (center-based) exercise (n=56) or a unsupervised (home-based) exercise (n=42) program and followed for 6 months postsurgery. INTERVENTIONS The supervised group attended a 4-week outpatient rehabilitation program supervised by a physiotherapist. The unsupervised group was given written and pictorial instructions to perform rehabilitation independently at home. MAIN OUTCOME MEASURES Western Ontario and McMaster Universities Osteoarthritis Index; Short-Form 36-item Health Questionnaire (SF-36) mental and physical component summary measures; University of California, Los Angeles activity scale; and timed Up and Go test. RESULTS There were no differences between the groups for any measure. The overall differences between the adjusted means were as follows: Western Ontario and McMaster Universities Osteoarthritis Index, 0.50 (95% confidence interval [CI], -6.8 to 5.7); SF-36 physical component summary, 0.8 (95% CI, -6.5 to 8.1); SF-36 mental component summary, 1.7 (95% CI, -4.1 to 7.4); University of California, Los Angeles activity scale, 0.3 (95% CI, 5.2 to 6.1); and timed Up and Go test, 0 seconds (95% CI, -1.4 to 1.3s). CONCLUSIONS The results demonstrated that outcomes in response to rehabilitation after THR are clinically and statistically similar whether the program was supervised or not. The results suggest that early rehabilitation programs can be effectively delivered unsupervised in the home to low-risk patients discharged home after THR. However, the relative effect of late-stage rehabilitation was not tested.

Vertical stiffness is not related to anterior cruciate ligament elongation in professional rugby union players

Background Novel research surrounding anterior cruciate ligament (ACL) injury is necessary because ACL injury rates have remained unchanged for several decades. An area of ACL risk mitigation which has not been well researched relates to vertical stiffness. The relationship between increased vertical stiffness and increased ground reaction force suggests that vertical stiffness may be related to ACL injury risk. However, given that increased dynamic knee joint stability has been shown to be associated with vertical stiffness, it is possible that modification of vertical stiffness could help to protect against injury. We aimed to determine whether vertical stiffness is related to measures known to load, or which represent loading of, the ACL. Methods This was a cross-sectional observational study of 11 professional Australian rugby players. Knee kinematics and ACL elongation were measured from a 4-dimensional model of a hopping task which simulated the change of direction manoeuvre typically observed when non-contact ACL injury occurs. The model was generated from a CT scan of the participants knee registered frame by frame to fluoroscopy images of the hopping task. Vertical stiffness was calculated from force plate data. Results There was no association found between vertical stiffness and anterior tibial translation (ATT) or ACL elongation (r=−0.05; p=0.89, and r=−0.07; p=0.83, respectively). ATT was related to ACL elongation (r=0.93; p=0.0001). Conclusions Vertical stiffness was not associated with ACL loading in this cohort of elite rugby players but a novel method for measuring ACL elongation in vivo was found to have good construct validity.

Non-rigid registration of cervical spine MRI volumes

Whiplash is the colloquial term for neck injuries caused by sudden extension of the cervical spine. Patients with chronic whiplash associated disorder (WAD) can experience neck pain for many years after the original injury. Researchers have found some evidence to suggest that chronic whiplash is related to the amount of intra-muscular fat in the cervical spine muscles. Hence, an important step towards developing a treatment for chronic WAD is a technique to accurately and efficiently measure the amount of intra-muscular fat in the muscles of the cervical spine. Our proposed technique for making this measurement is to automatically segment the cervical spine muscles using a fused volume created from multi-modal MRI volumes of the cervical spine. Multiple modes are required to enhance the boundaries between the different muscles to assist the following automatic segmentation process. However, before these multiple modes can be fused it is first necessary to accurately register these volumes. Hence, in this paper, we have proposed a new non-rigid multi-modal registration algorithm using the sum of conditional variance (SCV) with partial volume interpolation (PVI) similarity measure and Gauss-Newton (GN) optimization for the accurate registration of multi-modal cervical spine MRI volumes. The performance of the proposed approach is compared with the existing SCV based registration algorithm and the sum of the conditional squared deviation from the mode (SCSDM) method. The experimental results demonstrate that the proposed approach provides superior performance than the best existing approaches.