Monsef, Jad Bou

Study Design: This was a multicenter retrospective cohort study. Objective: The purpose of this study was to compare the surgical and radiographic outcomes of patients undergoing posterior cervical fusion (PCF) with constructs extending from C2 to T2 to patients with constructs extending from C3 to T1. Summary of Background Data: Limited evidence exists regarding the appropriate level of proximal and distal extension of PCF constructs. Methods: A multicenter retrospective cohort study of patients who underwent PCF between 2012 and 2020 was performed. Surgical and radiographic outcomes were compared between those who had C3–T1 or C2–T2 constructs. Results: A total of 155 patients were included in the study (C2–T2: 106 patients, C3–T1: 49 patients). There were no significant differences in demographics or preoperative symptoms between cohorts. Fusion rates were significantly higher in the C2–T2 (93%) than the C3–T1 (80%, P=0.040) cohort. When comparing the C2–T2 to the C3–T1 cohort, the C3–T1 cohort had a significantly greater rate of proximal junctional failure (2% vs. 10%, P=0.006), distal junctional failure (1% vs. 20%, P<0.001) and distal screw loosening (4% vs. 15%, P=0.02). Although ∆C2–C7 sagittal vertical axis increased significantly in both cohorts (C2–T2: 6.2 mm, P=0.04; C3–T1: 8.4 mm, P<0.001), correction did not significantly differ between groups (P=0.32). The C3–T1 cohort had a significantly greater increase in ∆C2 slope (8.0 vs. 3.1 degrees, P=0.03) and ∆C0–C2 Cobb angle (6.4 vs. 1.2 degrees, P=0.04). Conclusion: In patients undergoing PCF, a C2–T2 construct demonstrated lower rates of pseudarthrosis, distal junctional failure, proximal junctional failure, and compensatory upper cervical hyperextension compared with a C3–T1 construct.

Transdiscal screw fixation through the Boachie screw technique at the lumbosacral junction is a well-accepted procedure in the treatment of high-grade spondylolisthesis. This technique allows for partial reduction of the spondylolisthesis, decompression of the neural elements, and reliable posterior lumbosacral fixation. When performed properly, this procedure produces reliable results and high rates of arthrodesis with relief of preoperative neurological symptoms.

» Bearing materials that are used in total hip arthroplasty have undergone major developments in structure and durability since the 1960s. » Osteolysis and aseptic loosening associated with ultra-high molecular weight polyethylene had been a major concern; this led to the development of the first generation of highly cross-linked polyethylene (HXLPE), which was followed by a second generation of HXLPE. » The second generation of HXLPE was introduced with the aim of providing oxidative stability while maintaining high wear resistance. » Oxidative stabilization methods include mechanical deformation and annealing, incorporation of antioxidant-containing materials, high-pressure crystallization after melting, and polyethylene surface-grafting with a biocompatible polymer. » Results of clinical studies with ≤5 years of follow-up have shown that second-generation HXLPE acetabular liners are superior to any of the previous generation with regard to wear rates; however, additional studies are needed to compare second-generation materials among each other.