Do On-Table Radiographs Predict Postoperative Sagittal Alignment after Posterior Lumbar Fusion?

STUDY DESIGN

Retrospective Cohort Study OBJECTIVE: To determine if intraoperative on-table lumbar lordosis and segmental lordosis correlate with postoperative lordosis following single-level posterolateral decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF).

METHODS

Electronic medical records were reviewed for patients ≥18 years old who underwent PLDF or TLIF between 2012 and 2020. Lumbar lordosis and segmental lordosis were compared between pre-, intra-, and post-operative radiographs using paired t-tests. Significance was set at p<0.05.

RESULTS

A total of 200 patients met inclusion criteria. No significant differences in preoperative, intraoperative, or postoperative measurements were found between groups. Patients who underwent PLDF experienced less disc height loss over one year postoperatively (PLDF: 0.45 + 0.9 mm vs TLIF: 1.2 + 1.4 mm, p<0.001). Lumbar lordosis significantly decreased between intraoperative to postoperative radiographs at 2-6 weeks for PLDF (Δ: -4.0°, p<0.001) and TLIF (Δ: -5.6°, p<0.001), but no change was identified between the intraoperative and >6 month postoperative radiographs for PLDF (Δ: -0.3°, p=0.634) or TLIF (Δ: -1.6°, p=0.087). Segmental lordosis significantly increased from the preoperative to post-instrumentation intraoperative radiographs for PLDF (Δ: 2.7°, p<0.001) and TLIF (Δ: 1.8°, p<0.001), but it subsequently decreased at the final follow up for PLDF (Δ: -1.9°, p<0.001) and TLIF (Δ: -2.3°, p<0.001).

CONCLUSION

Subtle decreases in lumbar lordosis may be noticed in the early postoperative radiographs compared to intraoperative images on Jackson operative tables. However, these changes are not present at one-year follow-up as lumbar lordosis increases to a similar level as intraoperative fixation.

Neural Crest-Like Stem Cell Transcriptome Analysis Identifies LPAR1 in Melanoma Progression and Therapy Resistance

Metastatic melanoma is challenging to clinically address. Although standard-of-care targeted therapy has high response rates in patients with BRAF-mutant melanoma, therapy relapse occurs in most cases. Intrinsically resistant melanoma cells drive therapy resistance and display molecular and biologic properties akin to neural crest-like stem cells (NCLSC) including high invasiveness, plasticity, and self-renewal capacity. The shared transcriptional programs and vulnerabilities between NCLSCs and cancer cells remains poorly understood. Here, we identify a developmental LPAR1-axis critical for NCLSC viability and melanoma cell survival. LPAR1 activity increased during progression and following acquisition of therapeutic resistance. Notably, genetic inhibition of LPAR1 potentiated BRAFi ± MEKi efficacy and ablated melanoma migration and invasion. Our data define LPAR1 as a new therapeutic target in melanoma and highlights the promise of dissecting stem cell-like pathways hijacked by tumor cells. SIGNIFICANCE: This study identifies an LPAR1-axis critical for melanoma invasion and intrinsic/acquired therapy resistance.