Louisiana Research Day Program Book 2025

Anatomy and Epidemiology

Anatomy and Epidemiology

Phillip Lyons; Jenna Dittmar, PhD VCOM-Louisiana 54 MORPHOMETRIC ANALYSIS OF THE TALUS AND CALCANEUS: EVALUATING LEFT-RIGHT SYMMETRY AND WITHIN-GROUP VARIANCES IN A CADAVERIC SAMPLE

Nicholas Wong, OMS-II; Kaitlin Phillips, OMS-II; Nicholas Villar, OMS-II; Jenna M Dittmar, PhD VCOM-Louisiana 53 AN EXAMINATION OF HALLUX VLAGUS AND ARTICULAR CHONDRAL DAMAGE OF THE METATARSOPHALANGEAL JOINT

Context: Hallux valgus (HV), the lateral deviation of the great toe, is associated with structural and functional changes that can have an impact on quality of life. Objective: The purpose of this study is to examine if there is a relationship between HV and chondral damage within the first metacarpophalangeal joints and on the sesamoid bones. Materials: A total of 31 first metatarsophalangeal (MTP) joints from formalin fixed cadavers (M= 14, F=17) were radiographed and dissected to assess chondral damage on each articular surface. Methods: Chondral damage was macroscopically recorded on each articular surface of each MTP joint and sesamoid bones using a previously published grading system (0-4). Plain radiographs were taken of each foot to assess the hallux valgus angle (HVA) and the Manchester scale was used to assess the severity of HV deformity. HV was considered present if the lateral deviation of the first proximal phalanx (PP1) was greater than 20

degrees. These data were analyzed using chi squared or Fisher’s exact tests, as appropriate.

Context: The talus and calcaneus bones play critical roles in load-bearing and locomotion. Variations in their morphometric characteristics can have implications for clinical diagnosis, surgical planning, and prosthetic design. This study aims to contribute to understanding of these bones’ anatomical variations with an eye to potential clinical significance. Objective: To analyze and compare morphometric measurements of the talus and calcaneus bones, assessing group and within group variance from a sample of cadavers. Measurements of talus and calcaneus bones were obtained from 26 cadavers (52 calcanei and 52 tali) in the VCOM-LA anatomy lab. Additionally measurements will be obtained at the end of this year’s first-year anatomy course, when more cadavers become available. Morphometric parameters for the calcaneus included maximum length, body height, load arm width, and load arm length. Parameters for the talus included maximum body height, width of trochlea, maximum length of trochlea, and maximum talus length. Measurements were collected for both left and right sides using digital calipers and a bone board. Statistical

analyses included within-group variance calculations and paired comparisons of left and right measurements. Values were not recorded for measurements in which a fracture prevented accurate data collection (N=18). Results: Preliminary analysis revealed minimal mean variances between left and right measurements for most parameters, indicating symmetry. For example, the mean variance in maximum width of trochlea was 0.49 mm, while the mean variance in maximum talus length was 0.36 mm. Further analyses are ongoing to refine statistical significance and explore correlations between measurements. Additionally, results may change as we incorporate more cadavers into the study.

Results: In this sample, 13 individuals had HV on at least on MT1, though no severe cases (grade 4 on the Manchester scale) were observed. Eburnation, indicative of osteoarthritis, was present on the head of at least one MT1 in 42% (n=13) of the sample. Osteophytic lipping accompanied eburnation in 69% (9/13) of these cases. No relationship between eburnation and mild or moderate HV was found within this sample. Conclusions: There is no evidence to suggest that chondral damage within the first MTP joint is associated with mild or moderate HV. Future research will seek to increase the sample size of this study to include those with severe HV deformity (>40 degrees of lateral deviation). Limitation: This research was conducted on formalin-fixed cadavers. As such, it was not possible to acquire weight-bearing radiographs.

Conclusions: As this study is ongoing, we cannot make conclusions at this time.

66

67

2025 Research Recognition Day