An in vivo model for overloading-induced soft tissue injury

Reliability and Validity of Shore Hardness in Plantar Soft Tissue Biomechanics

Shore hardness (SH) is a cost-effective and easy-to-use method to assess soft tissue biomechanics. Its use for the plantar soft tissue could enhance the clinical management of conditions such as diabetic foot complications, but its validity and reliability remain unclear. Twenty healthy adults were recruited for this study. Validity and reliability were assessed across six different plantar sites. The validity was assessed against shear wave (SW) elastography (the gold standard). SH was measured by two examiners to assess inter-rater reliability. Testing was repeated following a test/retest study design to assess intra-rater reliability. SH was significantly correlated with SW speed measured in the skin or in the microchamber layer of the first metatarsal head (MetHead), third MetHead and rearfoot. Intraclass correlation coefficients and Bland-Altman plots of limits of agreement indicated satisfactory levels of reliability for these sites. No significant correlation between SH and SW elastography was found for the hallux, 5th MetHead or midfoot. Reliability for these sites was also compromised. SH is a valid and reliable measurement for plantar soft tissue biomechanics in the first MetHead, the third MetHead and the rearfoot. Our results do not support the use of SH for the hallux, 5th MetHead or midfoot.

Supersonic shear wave elastography of human tendons is associated with in vivo tendon stiffness over small strains

Supersonic shear wave (SW) elastography has emerged as a useful imaging modality offering researchers and clinicians a fast, non-invasive, quantitative assessment of tendon biomechanics. However, the exact relationship between SW speed and in vivo tendon stiffness is not intuitively obvious and needs to be verified. This study aimed to explore the validity of supersonic SW elastography against a gold standard method to measure the Achilles tendon's in vivo tensile stiffness by combining conventional ultrasound imaging with dynamometry. Twelve healthy participants performed maximal voluntary isometric plantarflexion contractions (MVC) on a dynamometer with simultaneous ultrasonographic recording of the medial gastrocnemius musculotendinous junction for dynamometry-based measurement of stiffness. The tendon's force-elongation relationship and stress-strain behaviour were assessed. Tendon stiffness at different levels of tension was calculated as the slope of the stress-strain graph. SW speed was measured at the midportion of the free tendon and tendon Young's modulus was estimated. A correlation analysis between the two techniques revealed a statistically significant correlation for small strains (r(10) = 0.604, p =.038). SW-based assessments of in vivo tendon stiffness were not correlated to the gold standard method for strains in the tendon>10 % of the maximum strain during MVC. The absolute values of SW-based Young's modulus estimations were approximately-three orders of magnitude lower than dynamometry-based measurements. Supersonic SW elastography should be only used to assess SW speed for the detection and study of differences between tissue regions, differences between people or groups of people or changes over time in tendon initial stiffness (i.e., stiffness for small strains).

Understanding occipital pressure sores in UK military casualties: a pilot study in healthy military personnel

INTRODUCTION

The high prevalence of occipital ulcers in UK military casualties observed during the conflict in Afghanistan is a multifactorial phenomenon. However, the consensus is that ulceration is triggered by excessive pressure that is maintained for too long during the use of the general service military stretcher. Thresholds for capillary occlusion are accepted benchmarks to define excessive pressure, but similar thresholds for safe/excessive duration of pressure application do not exist. To address this gap in knowledge, we propose to use the time it takes for a healthy person to feel pain at the back of the head as an initial indication of safe exposure to pressure.

METHODS

Healthy military personnel (16 male/10 female) were asked to lie motionless on a typical general service stretcher until they felt pain. Time-to-pain and the location of pain were recorded. To support the interpretation of results, baseline sensitivity to pain and pressure distribution at the back of the head were also measured. Independent samples t-test was used to assess differences between genders.

RESULTS

Twenty participants felt pressure-induced soft-tissue pain at the back of the head. The remaining six participants terminated the test due to musculoskeletal pain caused by poor ergonomic positioning. On average, pain at the occiput developed after 31 min (±14 min). Female participants were significantly more sensitive to pain (t(24)=3.038,p=0.006), but time-to-pain did not differ significantly between genders (p>0.05).

CONCLUSIONS

When people lie motionless on a typical military stretcher, the back of the head is the first area of the body that becomes painful due to pressure. The fact that pain develops in ≈30 min can help healthcare providers decide how frequently to reposition their patients who are unable to do this on their own. More research is still needed to directly link time-to-pain with time-to-injury.

Effect of Vacuum Sealing Drainage on Soft Tissue Injury of Traumatic Fracture and Its Effect on Wound Recovery

Purpose

The current work is mainly to explore the effect of vacuum sealing drainage (VSD) on soft tissue injury (STI) caused by traumatic fractures (TFs) and its effect on wound recovery.

Methods

We first selected 90 patients with TF STI from May 2019 to May 2021, of which 40 patients (control group) received routine treatment, and the other 50 patients (observation group) were treated with VSD. The curative effect, rehabilitation (changing dressing frequency, healing time, and hospitalization time), pain severity, patient comfort, and complications were evaluated and compared.

Results

The observation group exhibited a higher total effective rate, lower dressing change frequency, complication rate, and shorter healing time and hospital stay than the control group, which are statistically significant. Statistically milder pain sensation and better patient comfort were also determined in the observation group.

Conclusions

VSD is effective and safe in the treatment of TF-induced sexually transmitted infections, which can effectively accelerate wound recovery while reducing pain sensation and improving patient comfort, with clinical promotion value.