Instability in Patients with Lumbar Spine Disease or Fusion Undergoing Posterior Approach vs. Lateral Approach Primary Total Hip Arthroplasty

Background and Hypothesis: Dislocation rates after total hip arthroplasty (THA) in patients with fixed spinopelvic motion due to lumbar spine disease or fusion have been reported as high as 20%. Few studies exist that compare dislocation rates in patients with spine pathology undergoing THA via different surgical approaches. The purpose of this study was to compare postoperative dislocation rates in patients with lumbar spine disease or fusion between those undergoing a primary THA using a posterior versus direct lateral surgical approach. Experimental Design or Project Methods: With IRB approval, 1,205 primary THAs performed by two surgeons were retrospectively reviewed. One surgeon routinely performs THAs with a posterior approach while the other surgeon routinely uses a direct lateral approach. Chart review from the electronic medical record was conducted to identify patients who have lumbar spine disease or a lumbar spine fusion. Dislocations for patients with and without lumbar spine disease were compared by posterior approach and direct lateral approach. Results: 767 posterior approach and 431 direct lateral approach THAs were available for analysis. 43.6% of all THAs had lumbar spine pathology (337/767 posterior and 185/431 direct lateral). The overall dislocation rate was 1.26% (15/1195). The main predictors of dislocation in binary logistic regression were the presence of lumbar spine pathology (OR 5.24, 95% CI: 1.47–18.69, p=0.018) and posterior surgical approach (OR 7.93, 95% CI: 1.04–60.6, p=0.046). The dislocation rate for direct lateral approach THAs with lumbar spine pathology was significantly lower compared to posterior approach THAs with lumbar spine pathology (0.0% vs 3.6%, p=0.011). Conclusion and Potential Impact: Although there were few dislocations, the study results suggest a direct lateral approach for primary THA may be beneficial to reduce postoperative dislocation for patients with limited spinopelvic motion due to lumbar spine pathology.

Cervical Spine Pathology Increases the Risk of Rotator Cuff Tear: A Population-Based Cohort Study

Background: Patients with cervical radiculopathy typically present with shoulder pain and weakness; these symptoms are similar to those of rotator cuff disease. Studies investigating cervical spine pathology (CSP) as an independent risk factor for rotator cuff tear (RCT) are lacking in the literature. Purpose: To investigate the risk of RCT among patients with CSP who have undergone cervical diskectomy (CD) and to determine whether CD reduces this risk. Study Design: Cohort study; Level of evidence, 3. Methods: The authors queried the Taiwan National Health Insurance Research Database for patients diagnosed with CSP between 2004 and 2008 and followed up until the end of 2010. A control cohort comprised patients without CSP who were age- and sex-matched in a 4-to-1 ratio with patients with CSP through propensity score matching. A Cox multivariate proportional hazards model was applied to analyze the risk factors for RCT. After adjustment for confounders, the authors calculated the hazard ratio (HR) and adjusted HR (aHR) between the study and control cohorts. The effects of CD on the risk of RCT were also analyzed. Results: The study included 3245 patients and 12,980 matched controls. A higher RCT incidence rate was found in the CSP cohort, with an aHR of 1.52 (95% CI, 1.22-1.89; P < .001). Patients with CSP who underwent CD had a risk of RCT similar to that of the controls, with an aHR of 1.65 (95% CI, 0.90-3.03; P > .05). Conclusion: Patients with CSP had a 1.52-fold higher risk of RCT than healthy controls. Patients with CSP with CD did not have a high risk of RCT, possibly indicating a protective effect of diskectomy against RCT.

Acute thoracic disc heralded by change in spinal cord stimulation pattern: illustrative case

BACKGROUND Spinal cord stimulation (SCS) uses unique electric stimulation parameters to selectively treat specific regions of chronic or refractory back pain. Changing these parameters can lead to spreading paresthesia and/or pain beyond the desired region. OBSERVATIONS A patient with a history of stable, successful SCS treatment presented with acute development of paresthesias that were relieved by reduction of stimulation parameters. The patient required paradoxically lower SCS settings for control of chronic back pain. This presentation prompted further investigation, which revealed a new disc protrusion and cord compression at the level of the paddle lead. LESSONS In patients with SCS, a new onset of back pain accompanied by acute paresthesia that is reversible by reducing the SCS amplitude warrants investigation for new spine pathology.

The influence of spinal position on imaging findings: an observational study of thoracolumbar spine upright MRI in elite gymnasts

Purpose To investigate whether upright magnetic resonance imaging (MRI) has a role in defining thoracolumbar spine pathology in elite gymnastics. Methods A prospective cross-sectional observational study of National Senior and Junior Artistic gymnasts in three MRI positions (standard supine, upright flexed and extended positions). Two specialist musculoskeletal radiologists independently analysed images with neutral as a baseline with the effects of flexion and extension reported in line with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Results Forty (18 males) gymnasts aged 13–24 years with a mean (SD) of 32 (5.3) training hours per week consented with 75% showing MRI abnormalities. Degenerative disc disease (DDD) was evident in 55% participants with vertebral end plate (VEP) changes in 42.5%. Spondylolysis was present in 40% with an additional 17% showing chronic bilateral complete L5 pars defects. 23% participants demonstrated different MRI findings in upright flexion compared to neutral. Conclusion Findings suggest a high levels of MRI abnormalities in elite gymnastics including altered disc morphology and posterior element abnormalities. High prevalence of T11/12 DDD and VEP changes reflects the thoracolumbar junction being a transition zone. Upright MRI and varying spine position offer promise for enhanced visualisation of posterior element abnormalities.

Dynamics of pathomorphological changes in the structural organization of the intervertebral disc at the end of the seventh and fourteenth day of experimental opioid exposure at the ultrastructural level

In general, the modern literature pays attention to the issues of spine pathology and intervertebral discs. A significant percentage of vertebral disorders - scoliosis, osteochondrosis, spinal disc herniation, etc., occur as a result of exposure to various factors and manifest in changes of the intervertebral discs. The aim of our work was to study at the ultrastructural level the features of pathomorphological manifestations in the structural components of the intervertebral disc at the end of the seventh and fourteenth days of experimental opioid exposure. Materials and methods of research. The objects of the study were 32 sexually mature, white, male rats, weighing 92 - 103 g, aged 4.5 months. Animals were injected with nalbupine intramuscularly once daily (at 10-11 a.m.) for 14 days. The initial dose of nalbuphine was 8 mg/kg during the first week, 15 mg/kg during the second week. It created the conditions of chronic opioid exposure. Before sampling, the animals were withdrawn from the experiment using dibutyl ether. Intervertebral discs of rats were used as a material for ultrastructural study. Ultrastructural specimens were prepared according to the accepted methods. The results of the study. As a result of the sampling after 7 days of opioid exposure we found inhomogeneous osmiophilicity and compaction of the nucleus pulposus matrix in which intensively accumulated osmiophilic grains of glycogen proteoglycans, increased the number of collagen fibers, some of them were heterogeneous. It was also noted the development of moderate degenerative changes in some notochondral cells, which was accompanied by increased vacuolization of the cytoplasm by inhomogeneous compaction of the nucleus and an increase of heterochromatin there. After 14 days necrotic changes in the cells of the nucleus pulposus, as well as the destruction of collagen fibers of the annulus fibrosus were found. In particular, an increase in the amount of heterochromatin in the nucleui of notochondral cells, which was accompanied by a decrease in the volume of the nucleui and inhomogeneous swelling of the cytoplasm. Active fibroblasts were often visualized in the annulus fibrosus. Intense osmiophilicity and thickening of collagen fibers of the annulus fibrosus were observed in some areas of the fibrous ring. Focal destruction of collagen fibers was also noted. In the areas of destruction the fibrils of collagen fibers disintegrated into an inhomogeneous fine-grained stratified mass and were located loosely. Conclusions. At the end of the first week we found that the cytoplasmic processes of chondrocytes decreased in volume, shortened, underwent fragmentation and destruction, some of them detached from the surface of the plasmolemma. At the end of the second week signs of opioid exposure progressed and manifested by an increase in the destruction of cytoplasmic processes in chondrocytes. Also focal destruction of collagen fibers was noted.