Reevaluation of the topographical anatomy of the mid-thigh: A magnetic resonance and ultrasound imaging study.

Adductor canal (AC) and sciatic nerve (SN) blockades are commonly used during total knee arthroplasties for postoperative pain control. Medical professionals have begun to utilize single injection combined regional anesthesia methods due to increased patient comfort. In this study, we examined the topographical anatomy of the mid-thigh, which is recommended as the appropriate intervention level for combined AC and SN blockades, in order to provide a safe approach for clinicians. We examined 184 thigh magnetic resonance images (MRI) from 98 patients. We measured the diameter of the mid-thigh, anterior thigh muscle thickness, subcutaneous adipose tissue thickness, and SN depth on the MRIs. We obtained ultrasound (US) images of the vastoadductor membranes (VAM) of 26 volunteers, and measured the vertical distances between the greater trochanter and the adductor tubercle (A) and the greater trochanter and the upper edge of the VAM (B). We then proportioned B to A in order to determine in which part of the thigh the AC was located. The AC was in the distal third of the thigh, and the SN's depth was located in the third quarter of the thigh's diameter. Only the adductor magnus, and no neurovascular structure, was at risk of injury between the AC and the SN. The upper edge of the VAM was 6.5 cm below the mid-thigh, therefore it is not appropriate to suggest performing an AC blockade at mid-thigh. We think that it is safe to perform a combined AC and SN blockade in a single injection in selected patients.

Is lumbosacral transitional vertebra associated with lumbar disc herniation in patients with low back pain?

PURPOSE: To evaluate lumbosacral transitional vertebrae (LSTV) frequency in patients with low back pain and lumbar disc herniation (LDH) and to analyze correlations between LSTV presence and intervertebral disc degeneration. METHODS: This retrospective study included patients with low back pain applying between January 2021 and August 2021. Inclusion criteria were age of 18-65, presence of a standing lumbosacral Xray and a lumbar MRI taken within 2 weeks of the indexed symptoms. Patients with a history of spondylolisthesis, spondylodiscitis, scoliosis and vertebral neoplasia were excluded. A total of 1821 patients met the inclusion criteria. Radiographs and MRIs were evaluated by 2 radiologists. RESULTS: Of all patients, 61.4% were female and the mean age was 43.2 ± 12.2. LDH was detected in 57.7% of patients while a LSTV was present in 43.3%. Sacralization and LSTV were significantly different between the patients with and without an LDH. Patients with LSTV had a higher incidence of a LDH affecting 3 or more intervertebral disc levels (p < 0.001). There was a significant difference in-between LSTV and non-LSTV groups regarding the M1 and M2 intervertebral disc degeneration levels. CONCLUSION: A LDH is more common in the presence of a LSTV. Female sex is highly correlated with herniation. Three or more intervertebral disc levels are affected in the presence of an LSTV. Significantly higher degeneration incurs at the M1 and M2 intervertebral levels. Sacralization is a risk factors for a lumbar disc herniation.