Biology subjects

Spang, J. T.

Publications and source records attributed to Spang, J. T..

3 recordsLinked to original sources

bioRxiv2022

Degenerative changes are associated with severity of anterior cruciate ligament injury within the skeletally immature joint

Anterior cruciate ligament (ACL) injuries are a major problem in the pediatric and adolescent populations. Some of these injuries extend only partially through the tissue cross-section; yet, there is limited data to inform clinical treatment of such partial tears. In particular, it is unknown how injury severity impacts long-term degenerative changes in the joint. Here, we leverage a skeletally immature preclinical porcine model to evaluate joint biomechanics and degeneration after partial (isolated anteromedial (AM) or posterolateral (PL) bundle) or complete ACL injury. Six months after injury, joint laxity increases were minimal after PL bundle injury, minor after AM bundle injury, and major after ACL injury. Joint degeneration (evaluated in the cartilage and meniscus) was minimal after PL bundle injury, moderate after AM bundle injury, and substantial after ACL injury. With subjects grouped by clinical Lachman grade (indicating the extent of joint destabilization), degeneration was associated with increasing grade, irrespective of injury type. These findings point to the importance of considering joint laxity as a factor when treating young patients, particularly those with partial ACL injuries.

bioengineering↗

bioRxiv2021

Sex-Specific Function and Morphology of the Anterior Cruciate Ligament During Skeletal Growth in a Porcine Model

Pediatric anterior cruciate ligament (ACL) injuries are on the rise, and females experience higher ACL injury risk than males during adolescence. Studies in skeletally immature patients indicate differences in ACL size and joint laxity between males and females after the onset of adolescence. However, functional data regarding the ACL and its anteromedial and posterolateral bundles in the pediatric population remain rare. Therefore, this study uses a porcine model to investigate the sex-specific morphology and function of the ACL and its bundles throughout skeletal growth. Hind limbs from male and female Yorkshire pigs aged early youth to late adolescence were imaged using magnetic resonance imaging to measure the size and orientation of the ACL and its bundles, then biomechanically tested under anterior-posterior drawer using a robotic testing system. Joint laxity decreased (p<0.001) while joint stiffness increased (p<0.001) throughout skeletal growth in both sexes. The ACL was the primary stabilizer against anterior tibial loading in all specimens, while the functional role of the anteromedial bundle increased with age (p<0.001), with an earlier shift in males. ACL and posterolateral bundle cross-sectional area and ACL and anteromedial bundle length were larger in males than females during adolescence (p<0.01 for all), while ACL and bundle sagittal angle remained similar between sexes. Additionally, in situ ACL stiffness correlated with cross-sectional area across skeletal growth (r2=0.75, p<0.001 in males and r2=0.64, p<0.001 in females), but not within age groups. This study has implications for age and sex-specific surgical intervention strategies and suggests the need for human studies.

bioengineering↗

bioRxiv2019

Tissue-specific changes in size and shape of the ligaments and tendons of the porcine knee during post-natal growth

Prior studies have analyzed growth of musculoskeletal tissues between species or across body segments; however, little research has assessed the differences in similar tissues within a single joint. Here we studied changes in the length and cross-sectional area of four ligaments and tendons, (anterior cruciate ligament, patellar tendon, medial collateral ligament, lateral collateral ligament) in the tibiofemoral joint of female Yorkshire pigs through high-field magnetic resonance imaging throughout growth. Tissue lengths increased by 4-to 5-fold from birth to late adolescence across the tissues while tissue cross-sectional area increased by 10-20-fold. The anterior cruciate ligament and lateral collateral ligament showed allometric growth favoring change in length over change in cross-sectional area while the patellar tendon and medial collateral ligament grow in an isometric manner. Additionally, changes in the length and cross-sectional area of the anterior cruciate ligament did not increase as much as in the other ligaments and tendon of interest. Overall, these findings suggest that musculoskeletal soft tissue morphometry can vary within tissues of similar structure and within a single joint during post-natal growth.

bioengineering↗