Despite the clinical relevance of back pain and intervertebral disc herniation, the lack of reliable models has strained their molecular understanding. We characterized the lumbar spinal phenotype of C57BL/6 and SM/J mice during aging. Interestingly, old SM/J lumbar discs evidenced accelerated degeneration, associated with high rates of disc herniation. SM/J AF's and degenerative human's AF transcriptomic profiles showed altered immune cell, inflammation, and p53 pathways. Old SM/J mice presented increased neuronal markers in herniated discs, thicker subchondral bone, and higher sensitization to pain. Dorsal root ganglia transcriptomic studies and spinal cord analysis exhibited increased pain and neuroinflammatory markers associated with altered extracellular matrix regulation. Immune system single-cell and tissue level analysis showed distinctive T-cell and B-cell modulation and negative correlation between mechanical allodynia and INF-α, IL-1β, IL2, and IL4, respectively. This study underscores the multisystemic network behind back pain and highlights the role of genetic background and the immune system in disc herniation disease.
Slipped capital femoral epiphysis (SCFE) is associated with a spectrum of proximal femoral deformity and femoroacetabular impingement (FAI). Little attention has been given, however, to the possible effect of SCFE on remaining hip growth. Our observation that some acetabula in hips with SCFE have various dysmorphology led us to evaluate the growth of the hip in our patients with SCFE. We performed an IRB-approved retrospective study of our intramural SCFE database which identified 108 hips with unilateral SCFE, at least 2 years of radiographic followup, and closure of triradiate cartilage, greater trochanter and proximal femoral physis. The contralateral non-SCFE hip was used as control. Average age at presentation was 12.3 y. 49 patients were male, 59 female. Statistically significant differences were noted between SCFE and control hip both at both presentation and last followup(FU): Mean LCEA lower in SCFE hip at presentation by 0.97 degree; increasing to 4.36 degrees at last FU(p<0.0001). No difference noted in mean Tonnis roof angle at presentation, but at last FU SCFE hips had mean roof angle difference of 3.2 degrees higher than control(p<.0001). In some of our SCFE patients, acetabular deformity has impacted treatment. Ongoing studies may clarify risk factors for the development of problematic acetabular deformity associated with SCFE and perhaps allow prevention of secondary acetabular deformity.
The intra-epiphyseal growth of the proximal femur has been focus of studies because of the potential relationship with the development of slipped capital femoral epiphysis and cam deformity in femoroacetabular impingement. We aimed to evaluate the developmental pattern of the epiphyseal tubercle and extension in normal boys and girls from eight to fifteen years, without hip conditions. We performed three-dimensional (3D) analysis of pelvic computed tomographic scans of 80 subjects with suspect of appendicitis, consisting of five boys and five girls for each age, from eight to 15 years old. Images were segmented slice by slice at the level of the growth plate using biplanar orientation. The 3D-segmented epiphyses were used to measure the location and height of the tubercle, the height of the epiphyseal extension, and the epiphyseal diameter. We found that the epiphyseal tubercle was eccentrically located at the posterolateral quadrant of the physeal surface. The absolute height of the epiphyseal tubercle did not vary between ages (R2=0.04; p=0.101). The epiphyseal diameter increased with age (R2=0.74; p<0.001), making the tubercle height proportionally smaller with the epiphyseal growth (9% reduction in tubercle height normalised by the epiphyseal diameter). The normalised epiphyseal extension height significantly increased by 160% from 8 to 15 years of age. Our observation validates the hypothesis of the cupping mechanism provided by the peripheral growth of the epiphyseal extension, while the epiphyseal tubercle relatively decreases in size during the skeletal growth. Further research will be important to determine the role of these structures in the epiphyseal stability.
