Prognostic Factors for Outcome of Fusion Surgery in Patients With Chronic Low Back Pain - A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: This systematic review aims to identify prognostic factors, encompassing biomedical and psychosocial variables, linked to outcome of fusion surgery for chronic low back pain (CLBP) in single or two-level lumbar degenerative spinal disorders. Identifying these factors is crucial for decision making and therefore long-term treatment outcome. METHODS: A systematic search (PROSPERO ID: CRD4202018927) from January 2010 to October 2022 was conducted, utilizing Medline, Embase, and the Cochrane Database of Systematic Reviews (CDSR, CENTRAL). Prognostic factors associated with various outcomes, including functional status, back and leg pain, health-related quality of life, complications, return to work, and analgesic use, were assessed. Risk of bias was determined using QUIPS, and the quality of evidence was evaluated using GRADE approach. RESULTS: Of the 9852 initially screened studies, eleven studies (n = 16,482) were included in the analysis. In total, 161 associations were identified, with 67 prognostic factors showing statistical significance (P < 0.05). Thirty associations were supported by two or more studies, and only eight associations were eligible for meta-analyses: female gender remained statistically significant associated with decreased postoperative back pain, but negatively associated with complication rates and functional status, and smoking with increased postoperative back pain. CONCLUSION: Only female gender and smoking were consistently associated with outcome of fusion for CLBP. Most of the included studies exhibited low to moderate methodological quality, which may explain the relatively weak associations identified for the assessed prognostic factors.

[A man with acute, painless swelling of the hand]. / Een man met acute, pijnloze zwelling van de hand.

A 48-year-old man visited the hand surgery outpatient clinic with acute, painless swelling of the dorsal side of the right hand and fingers. We found erythema and crepitations of the skin. Laboratory tests showed no signs of infection. After X-ray and echography of the hand we made the diagnosis subcutaneous emphysema. It was caused by a microtrauma with high pressure air.

A biomechanical analysis of the self-retaining pedicle hook device in posterior spinal fixation.

Regular hooks lack initial fixation to the spine during spinal deformity surgery. This runs the risk of posterior hook dislodgement during manipulation and correction of the spinal deformity, that may lead to loss of correction, hook migration, and post-operative junctional kyphosis. To prevent hook dislodgement during surgery, a self-retaining pedicle hook device (SPHD) is available that is made up of two counter-positioned hooks forming a monoblock posterior claw device. The initial segmental posterior fixation strength of a SPHD, however, is unknown. A biomechanical pull-out study of posterior segmental spinal fixation in a cadaver vertebral model was designed to investigate the axial pull-out strength for a SPHD, and compared to the pull-out strength of a pedicle screw. Ten porcine lumbar vertebral bodies were instrumented in pairs with two different instrumentation constructs after measuring the bone mineral density of each individual vertebra. The instrumentation constructs were extracted employing a material testing system using axial forces. The maximum pull-out forces were recorded at the time of the construct failure. Failure of the SPHD appeared in rotation and lateral displacement, without fracturing of the posterior structures. The average pull-out strength of the SPHD was 236 N versus 1,047 N in the pedicle screws (P < 0.001). The pull-out strength of the pedicle screws showed greater correlation with the BMC compared to the SPHD (P < 0.005). The SPHD showed to provide a significant inferior segmental fixation to the posterior spine in comparison to pedicle screw fixation. Despite the beneficial characteristics of the monoblock claw construct in a SPHD, that decreases the risk of posterior hook dislodgement during surgery compared to regular hooks, the SPHD does not improve the pull-out strength in such a way that it may provide a biomechanically solid alternative to pedicle screw fixation in the posterior spine.