Evaluation of a fiber-optic technique for recording intramuscular pressure in the human leg

Novel Insights Into the Intratendinous Pressure Behavior of the Achilles Tendon in Athletes

BACKGROUND

In contrast to other musculoskeletal tissues, the normal pressure behavior of the Achilles tendon is poorly understood. This study aimed to explore the normal intratendinous and perfusion pressures of the Achilles tendon at rest and during exercise, and investigate potential correlations with tendon load and morphology.

HYPOTHESIS

Intratendinous and perfusion pressures of the Achilles tendon exhibit similarities to other musculoskeletal tissues and depend on tendon load and morphology.

STUDY DESIGN

Observational study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 22 recreational athletes were enrolled. Demographics, activity level, and blood pressures were recorded. Achilles tendon thickness and echogenicity were assessed 25 mm proximal to the posterosuperior calcaneal border. In this region, intratendinous and perfusion pressures of the Achilles tendon were measured at rest and during isometric plantarflexion up to 50 N, using the microcapillary infusion technique. Linear mixed models were used to investigate the effects of plantarflexion force, tendon thickness, and echogenicity on intratendinous and perfusion pressures.

RESULTS

At rest, intratendinous and perfusion pressures of the Achilles tendon were 43.8 ± 15.2 and 48.7 ± 18.4 mmHg, respectively. Intratendinous pressure increased linearly with plantarflexion force, reaching 101.3 ± 25.5 mmHg at 50 N (P < 0.01). Perfusion pressure showed an inverse relationship, dropping below 0 mmHg at 50 N (P < 0.01). Neither intratendinous nor perfusion pressures of the Achilles tendon correlated with tendon thickness or echogenicity.

CONCLUSION

The normal intratendinous resting pressure of the Achilles tendon is higher than other musculoskeletal tissues, making it more susceptible to ischemia. During exercise, intratendinous pressure increases significantly to a level that lowers perfusion pressure, thereby compromising blood supply at already low plantarflexion forces.

CLINICAL RELEVANCE

Given the potential role of ischemia in Achilles tendinopathy, our findings caution against intratendinous injections, as they may exacerbate high intratendinous resting pressure, and against prolonged postexercise tendon stretching, as the associated rise in intratendinous pressure may impair the required hyperemic response.

Comparison and convergence of compartment syndrome techniques: a narrative review

INTRODUCTION

Compartment syndrome (CS) continues to be a legitimate orthopedic emergency as it leads to thousands of amputations and permanent nerve and tissue damage to undiagnosed patients for more than eight hours. In CS, intracompartmental pressure is elevated, causing reduced blood flow inside the limb compartments. An erroneous diagnosis may result in unnecessary fasciotomies, the only treatment for this condition.

AREAS COVERED

This review examines the previous and current diagnostic and therapeutic practices for compartment syndrome. It also performs a comparative analysis of each diagnostic technique and its foresights.

EXPERT OPINION

Currently, most clinicians rely on a physical examination of the patient to diagnose CS. The primary reason for the physical examination is the lack of a gold-standard device. The invasive intracompartmental pressure (ICP) measurement technique is still the most commonly used. On the other hand, many non-invasive approaches have the potential to be used as diagnostic tools; however, more research is needed before they can be accepted as standard clinical approaches.

Application of Simulated Arms with Real-Time Pressure Monitor in Casting and Splinting by Physiological Sensors

In the real condition, the small sensor found it difficult to detect the position of the pressure sore because of casting displacement clinically. The large sensor will detect the incorrect pressure value due to wrinkles without close to arm. Hence, we developed a simulated arm with physiological sensors combined with an APP and a cloud storage system to detect skin pressure in real time when applying a short arm cast or splint. The participants can apply a short arm cast or splint on the simulative arm and the pressure in the cast or splint could be immediately displaced on the mobile application. The difference of pressure values from six pressure detection points of the simulated arm between the intern and the attending physician with 20-year working experience were 22.8%, −7.3%, 25.0%, 8.6%, 38.2%, 49.6%, respectively. It showed that the difference of pressure values in two farthest points, such as radius stab and ulnar styloid, was maximal. The pressures on the skin surface of the short arm cast were within acceptable range. Doctors would obtain reliable reference data and instantly understand the tightness of the swathed cast which would enable them to adjust it at any time to avoid complications.

Journal of clinical monitoring and computing 2016 end of year summary: anesthesia

Clinical monitoring and computing are essential during general anesthesia. As a result it would be impossible to review all the articles published in the Journal of Clinical Monitoring and Computing that are relevant to anesthesia. We therefore will limit this summary to those articles that are uniquely related to anesthesia. The topics include: anesthesia machines; ensuring the airway; anesthetic depth; neuromuscular transmission monitoring; locoregional anesthesia; ultrasound; and pain.