Modified Rib Sparing Direct Lateral Minimally Invasive Vertebrectomy for Treatment of Metastatic Spinal Cord Compression

Objective Metastatic spinal cord compression (MSCC) is a common complication of metastatic disease with neurological morbidity in the thoracic and upper lumbar spine. We describe a modified rib-sparing direct lateral minimally invasive (MIS) approach. for the purpose of vertebrectomy. This technique obviates the need for rib resection and chest drain, facilitating early mobilisation. This is especially applicable to a sub-group of patients who may not be well enough for an open approach. Method Technical note and retrospective case series in a single centre over a 5 year period. Results 14 patients were identified who underwent the MIS approach vertebrectomy for MSCC. 12/14 underwent posterior fixation, and 2 underwent vertebroplasty. 11/14 (79%) had less than 1L blood loss during the procedure. The mean duration of the procedure was 5 hours 51 minutes. 5/14 (36%) avoided high dependency unit (HDU) care, and the median duration of time spent in HDU was 1.5 days. The median length of stay in hospital was 16 days, and 4/14 (29%) were discharged within 1 week. There were 1/14 major complications requiring revision surgery. Conclusion A modified rib-sparing MIS approach for vertebrectomy is well tolerated in the treatment of MSCC and is associated with low blood loss and short hospital stays. This may be an option in patients who otherwise may not be considered for an anterior reconstruction

Surgical Treatment of Spinal Stenosis in Achondroplasia:Literature Review Comparing Results in Adults and Paediatrics

BACKGROUND: This study aims to assess the quantity and quality of available literature on surgical treatment outcomes of spinal stenosis in adult and paediatric achondroplasia patients through a systematic review of literature and to investigate the suitability of conducting a meta-analysis on outcomes of surgical treatment. METHODS: Online databases were searched according to PRISMA guidelines. No restrictions regarding study design, sample size, previous treatment, or publication date were implemented. The following terms: “Spinal stenosis”, “Spinal Decompression”, “Spinal fusion”, each term separately combined with the term “Achondroplasia” were used. Quality of the included studies were assessed used the Modified Coleman method. RESULTS: Five adult and four paediatric single-sample non-comparative studies were identified for inclusion (176 adult and 102 paediatric patients). Meta-analyses assessed the proportion of patients achieving full resolution of symptoms to be 0.51 (95% CI 0.00 to 1.00); the proportion of patients achieving full or partial resolution of symptoms to be 0.90 (95% CI 0.84 to 0.97); the proportion of procedures requiring re-operation to be 0.42 (95% CI 0.34 to 0.50; and the proportion of procedures involving dural tears to be 0.20 (95% CI 0.02 to 0.39). Statistical heterogeneity was very high for full resolution of symptoms and requirement for dural repair; and very low for other outcomes. CONCLUSIONS: The available literature on this population and condition is sparse, highly heterogenous, and is generally of low quality limiting the value of meta-analysis. Overall, outcomes of surgical decompression of symptomatic spinal stenosis in achondroplasia patients show consistent degree of resolution of symptoms. Duration of symptoms prior to surgical treatment appears to play an important role in the overall outcome of treatment. Therefore, a delay in diagnosis and treatment can potentially be detrimental in achieving a better outcome

Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

The posterior longitudinal ligament and peridural (epidural) membrane

The posterior longitudinal ligament (PLL) is described as having deep and superficial layers, though recent studies have suggested that there may be three layers. Additional membranous structures have been reported, although there is no consensus as to their presence or morphology. The vertebral canal and dural sac were opened and the spinal nerve roots and spinal cord removed. The anterior dural ligaments were sectioned at their attachment to the PLL and the dura mater freed from the posterior surface of the vertebral bodies. The borders of the PLL were identified and the superficial and deep layers separated. The PLL is a wide band in the cervical region becoming more denticulate inferiorly, the widest parts being attached to the intervertebral discs (IVD) and adjacent vertebral body where the superficial and deep layers could not be separated. A continuous well developed peridural membrane attaching to the pedicles was present anterior to the deep PLL as well as a separate, thin, incomplete layer in 6 of 18 cadavers, covering the posterior surface of the superficial PLL

Tibiofibula Transposition in High-Energy Fractures

We report two cases of failed attempts at closed reduction of high-energy tibial fractures with an associated fibula fracture. The first case was a 39-year-old male involved in high-speed motorbike collision, while the second was a 14-year-old male who injured his leg following a fall of three metres. Emergency medical services at the scenes of the accidents reported a 90-degree valgus deformity of the injured limb and both limbs were realigned on scene and stabilized. Adequate alignment of the tibia could not be achieved by manipulation under sedation or anaesthesia. Open reduction and exposure of the fracture sites revealed that the distal fibula fragment was “transposed” and entrapped in the medulla of the proximal tibial fragment. Reduction required simulation of the mechanism of injury in order to disengage the fragments and allow reduction. Tibiofibula transposition is a rare complication of high-energy lower limb fractures which has not previously been reported and may prevent adequate closed reduction. Impaction of the distal fibula within the tibial medulla occurs as the limb is realigned by paramedic staff before transfer to hospital. We recommend that when this complication is identified the patient is transferred to the operating room for open reduction and stabilization of the fracture

IL-17A and TNF Modulate Normal Human Spinal Entheseal Bone and Soft Tissue Mesenchymal Stem Cell Osteogenesis, Adipogenesis, and Stromal Function

Objective: The spondylarthritides (SpA) are intimately linked to new bone formation and IL-17A and TNF pathways. We investigated spinal soft tissue and bone mesenchymal stem cell (MSC) responses to IL-17A and TNF, including their osteogenesis, adipogenesis, and stromal supportive function and ability to support lymphocyte recruitment. Methods: Normal spinal peri-entheseal bone (PEB) and entheseal soft tissue (EST) were characterized for MSCs by immunophenotypic, osteogenic, chondrogenic, and adipogenic differentiation criteria. Functional and gene transcriptomic analysis was carried out on undifferentiated, adipo- differentiated, and osteo-differentiated MSCs. The enthesis C-C Motif Chemokine Ligand 20-C-C Motif Chemokine Receptor 6 (CCL20-CCR6) axis was investigated at transcript and protein levels to ascertain whether entheseal MSCs influence local immune cell populations. Results: Cultured MSCs from both PEB and EST displayed a tri-lineage differentiation ability. EST MSCs exhibited 4.9-fold greater adipogenesis (p < 0.001) and a 3-fold lower osteogenic capacity (p < 0.05). IL-17A induced greater osteogenesis in PEB MSCs compared to EST MSCs. IL-17A suppressed adipogenic differentiation, with a significant decrease in fatty acid-binding protein 4 (FABP4), peroxisome proliferator-activated receptor gamma (PPARγ), Cell Death Inducing DFFA Like Effector C (CIDEC), and Perilipin-1 (PLIN1). IL-17A significantly increased the CCL20 transcript (p < 0.01) and protein expression (p < 0.001) in MSCs supporting a role in type 17 lymphocyte recruitment. Conclusions: Normal spinal enthesis harbors resident MSCs with different in vitro functionalities in bone and soft tissue, especially in response to IL-17A, which enhanced osteogenesis and CCL20 production and reduced adipogenesis compared to unstimulated MSCs. This MSC-stromal-enthesis immune system may be a hitherto unappreciated mechanism of “fine tuning” tissue repair responses at the enthesis in health and could be relevant for SpA understanding