Appendicular skeletal muscle mass assessment in dogs: a scoping literature review

Abstract

Background Monitoring changes in appendicular skeletal muscle mass is frequently used as a surrogate marker for limb function. The primary objective of this study was to review scientific information related to the assessment of appendicular skeletal muscle mass in dogs. The secondary objective was to develop practical recommendations for serial evaluation of muscle mass. Methods A scoping review was conducted with a systematic search of PubMed, Web of Science, CAB abstract, and Cochrane from inception to June 2021. The following modalities were included in the search: limb circumference, diagnostic ultrasound, computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry. Results A total of 62 articles that measured appendicular skeletal muscle mass in dogs were identified. Limb circumference (55 articles) was the most commonly used modality. Its reliability was investigated in five studies. Several factors, including measuring tape type, body position, joint angles, and the presence of hair coat, were reported as variables that can affect measurements. Diagnostic ultrasound (five articles) was validated in three articles, but there is scarce information about observer reliability and variables affecting the measurement. Computed tomography (four articles) and magnetic resonance imaging (one article) have been used to validate other modalities at a single time point rather than as a clinical tool for serial muscle mass monitoring. Dual-energy x-ray absorptiometry (two articles) has been used to quantify specific skeletal muscle mass but was mainly used to evaluate body composition in dogs. Conclusion Limb circumference and ultrasound are likely the main modalities that will continue to be used for serial muscle mass measurement in the clinical setting unless a new technology is developed. The reliability of limb circumference is questionable. Several key factors, including measuring tape type, body position, joint angles, and coat clipping, need to be controlled to improve the reliability of limb circumference measurements. Ultrasound may provide a reasonable alternative, but further studies are required to evaluate the reliability of this modality and identify factors that influence ultrasound measurements.

Comparative analysis of post-operative rehabilitation approaches for medial patellar luxation in small-breed dogs

“…TMC measurement was used to assess limb muscle mass, reflecting the extent of limb usage and muscle development [29,30]. A higher TMC indicates a greater muscle mass, indicating a limb in better condition.…”

Evaluation of a method to measure the ratio of pelvic limb to thoracic limb girth in dogs

“…Limb girth measurement reliability overall has been considered questionable due to intra-and interobserver variation, patient positioning, or the variability in measurement devices used (Kim et al, 2022). To the authors' knowledge, although a landmark-incorporated limb girth measurement has been discussed by Kramer et al (2018), there are currently no peer-reviewed studies that have evaluated a landmark-incorporated limb measurement for evaluation of muscle mass in dogs.…”

“…Therefore, an economical, non-invasive, and reproducible measurement that can be performed in a clinical setting within a short amount of time, like limb girth measurements, would be optimal for veterinary clinicians. However, a recent literature review reported that current techniques for limb girth measurements have been shown to be of questionable reliability (Kim et al, 2022). Previous studies have utilised landmarks, however, anatomical landmarks were used to identify the proximal and distal points to then calculate a percentage of distance at which the actual circumferential limb measurement will be obtained (Smith et To achieve a reproducible limb girth measurement, a technique with excellent reliability would be required.…”