Threaded Intramedullary Nails Are Biomechanically Superior to Crossed K-wires for Metacarpal Neck Fractures.

BACKGROUND: Intramedullary nail (IMN) fixation of metacarpal fractures is an alternative to Kirschner wire (K-wire) fixation. The goal of this study was to compare the biomechanical properties of K-wire fixation with a threaded IMN (InNate; ExsoMed, Aliso Viejo, California). METHODS: The study design was based on previously described biomechanical models for evaluating metacarpal fractures. Sixteen fresh frozen small finger-matched and ring finger-matched pairs were randomized to either IMN or 0.045 in K-wire fixation after receiving a standardized neck osteotomy. Proper implant placement was confirmed with plain radiographs. Specimens then underwent loading in a 3-point bend configuration. Load to failure (LTF), stiffness, and fracture displacement were recorded. Mechanical failure was defined by a sharp change in the load-displacement curve. RESULTS: Age, sex, sidedness (left or right), and digit (ring or small finger) were evenly distributed between groups. The IMN had a significantly higher LTF than K-wires (546 N vs 154 N, P < .001). The K-wire fixation demonstrated plastic deformation between 75 and 150 N. Intramedullary nail stiffness was higher than that of K-wires (155.89 N/mm vs 59.28 N/mm, P < .001). CONCLUSIONS: When surgical fixation is indicated for metacarpal neck and shaft fractures, the threaded IMN is biomechanically superior to crossed K-wires with the application of 3-point bend.

Surgical strategies for spinal infections: A narrative review.

The successful operative management of spinal infections necessitates a thoughtful approach. Ideal treatment combines the universal goals of any spine operation, which are decompression of the neural elements and stabilization of instability, with source control and eradication of infection. Techniques to treat infection have evolved independently and alongside advances in implant technology and surgical techniques. This review will seek to outline current thinking on approaches to both primary and secondary spinal infections.

Treatment of Chronic Femoral Neck Fracture With Cemented Bipolar Hemiarthroplasty and Management of Intraoperative Fracture With Cerclage Cabling.

SUMMARY: We cover the operative treatment of a neglected chronic femoral neck fracture nonunion treated at 6 months. We begin with a description of the case and concomitant injuries. The operative portion includes the direct lateral approach with the patient in lateral decubitus position, exposure of the fracture site, osteotomy of the neck, debridement of the nonunion site, broaching, trialing, recognition and treatment of an intraoperative proximal femur fracture using cerclage cabling above and below the lesser trochanter, cementation of final components, and reduction. We conclude with the patient's radiographs at 2 weeks and clinical outcome at 6-week follow-up.

Decreasing Trend in Complications for Patients With Obesity and Metabolic Syndrome Undergoing Total Knee Arthroplasty From 2006 to 2017.

BACKGROUND: To describe longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing total knee arthroplasty (TKA) and the impact on complications. METHODS: We identified primary TKA patients between 2006 and 2017 within the National Surgical Quality Improvement Program database. We recorded patient demographics and 30-day complications. We labeled those with an obese Body Mass Index (BMI ≥30), hypertension, and diabetes as having MetS. We used regression to evaluate trends in BMI and complications over time and variables associated with the odds of complication. RESULTS: We identified 270,846 TKA patients, 63.71% of which were obese (n = 172,333), 15.21% morbidly obese (n = 41,130), and 12.37% met the criteria for MetS (n = 33,470). Mean BMI increased by 0.03 per year (0.02-0.05). Despite this, the odds of adverse events in obese patients decreased: major complications by 0.94 (0.93-0.96) and minor complications by 0.94 (0.93-0.95). The proportion of patients with MetS remained stable; however, we found improvements in major (0.94 [0.91-0.97]) and minor complications (0.97 [0.94-1.00]) over time. MetS components (hypertension, diabetes, and BMI ≥40) were associated with major and minor complications in obese patients, while neuraxial anesthesia lowered the odds of major complications in obese patients (0.87 [0.81-0.92]). CONCLUSION: Mean BMI in primary TKA patients increased from 2006 to 2017. MetS components diabetes and hypertension elevated the odds of complications in obese patients. Rates of complications in patients with obesity and MetS exhibited a longitudinal decline. These findings may reflect increased awareness and improved management of these patients.

The Clinical Impact of Image Guidance and Robotics in Spinal Surgery: A Review of Safety, Accuracy, Efficiency, and Complication Reduction.

Image guidance (IG) and robotic-assisted (RA) surgery are modern technological advancements that have provided novel ways to perform precise and accurate spinal surgery. These innovations supply real-time, three-dimensional imaging information to aid in instrumentation, decompression, and implant placement. Although nothing can replace the knowledge and expertise of an experienced spine surgeon, these platforms do have the potential to supplement the individual surgeon's capabilities. Specific advantages include more precise pedicle screw placement, minimally invasive surgery with less reliance on intraoperative fluoroscopy, and lower radiation exposure to the surgeon and staff. As these technologies have become more widely adopted over the years, novel uses such as tumor resection have been explored. Disadvantages include the cost of implementing IG and robotics platforms, the initial learning curve for both the surgeon and the staff, and increased patient radiation exposure in scoliosis surgery. Also, given the relatively recent transition of many procedures from inpatient settings to ambulatory surgery centers, access to current devices may be cost prohibitive and not as readily available at some centers. Regarding patient-related outcomes, much further research is warranted. The short-term benefits of minimally invasive surgery often bolster the perioperative and early postoperative outcomes in many retrospective studies on IG and RA surgery. Randomized controlled trials limiting such confounding factors are warranted to definitively show potential independent improvements in patient-related outcomes specifically attributable to IG and RA alone. Nonetheless, irrespective of these current unknowns, it is clear that these technologies have changed the field and the practice of spine surgery. Surgeons should be familiar with the potential benefits and tradeoffs of these platforms when considering adopting IG and robotics in their practices.

Inferior tilt of the glenoid leads to medialization and increases impingement on the scapular neck in reverse shoulder arthroplasty.

BACKGROUND: In reverse shoulder arthroplasty, Inferior tilt was originally promoted to decrease rates of baseplate failure. However, the literature is conflicting regarding the effect of tilt on scapular neck impingement, which has been associated with an increased risk of notching, increased risk of impingement-related instability, and decreased range of motion. We hypothesized that inferior tilt of -10° would lead to increased medialization and increased scapular neck impingement compared with 0° of tilt. METHODS: Twenty patients without glenoid bone loss undergoing reverse shoulder arthroplasty (RSA) at a single institution underwent computed tomography scans of the entire scapula and proximal humerus for preoperative planning. For each patient, we digitally implanted a 25-mm glenoid baseplate flush with the inferior rim of the glenoid. We then simulated impingement-free range of motion with 16 different implant configurations: glenoid tilt (0° vs. -10°), baseplate lateralization (0 mm vs. +6 mm), glenosphere size (36 mm vs. 42 mm), and neck-shaft angle (135° vs. 145°). The primary endpoint was external rotation with the arm at the side (ERS), which is the primary mode of both notching and impingement-related instability, and the secondary endpoint was adduction (ADD). We recorded the RSA angle, preoperative scapular neck length (SNL), and postoperative SNL. Data were compared by paired t tests and a multivariable regression analysis. RESULTS: In every simulation, inferior tilt led to more impingement on the scapular neck. Inferior tilt of the glenoid component was associated with a mean 27% decrease in impingement-free external rotation (P < .01 in all cases) and a mean 32% decrease in impingement-free ADD (P < .01 in all cases). Inferior tilt removed 3.2 mm of additional SNL (P < .001). Multivariable regression analysis showed that lateralization had the most impact on impingement-free external rotation and ADD (P < .001), followed by glenosphere size (P < .001), neck-shaft angle (P < .001), postoperative SNL (P < .001), glenoid tilt (P = .001), inclination (P < .001), and RSA angle (P = .023 for ERS and P = .025 for ADD). CONCLUSION: Relative to 0° of tilt of the baseplate, inferior tilt of -10° was associated with increased scapular neck impingement in ERS and ADD, likely a result of the increased medialization necessary to seat an inferiorly tilted implant, which shortens the scapular neck and brings the humerus closer to the scapula. This scapular neck impingement increases the risk of notching and impingement-related instability.

Inpatient Outcomes in Dialysis Dependent Patients Undergoing Elective Cervical Spine Surgery for Degenerative Cervical Conditions.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate inpatient outcomes in dialysis dependent patients undergoing elective cervical spine surgery. METHODS: A total of 1605 dialysis dependent patients undergoing elective primary or revision cervical spine surgery for degenerative conditions were identified from the National Inpatient sample from 2002 to 2012 and compared to 1 450 642 nondialysis-dependent patients undergoing the same procedures. The National Inpatient Sample is a de-identified database; thus, no institutional review board approval was needed. RESULTS: Dialysis dependence was associated with higher inpatient mortality rates (7.5% vs 1.9%; P < .001) as well as both major (17.3% vs 0.6%; P < .001) and minor (36.8% vs 10.5%; P < .001) complication rates as compared with nondialysis-dependent patients. Dialysis-dependent patients had substantially increased mean lengths of stay (9.8 days compared with 2.0 days; P < .001) and total hospital charges ($141 790 compared with $46 562; P < .001). CONCLUSION: Dialysis-dependence is associated with drastically increased complication rates, risk of mortality, and represent a significant financial and psychosocial burden to patients undergoing elective cervical spine surgery. Both surgeons and patients should be aware of these risks while planning elective surgeries.

Operative Fixation of a Displaced Midshaft Clavicle Fracture.

Midshaft clavicle fractures are frequently encountered orthopaedic injuries. Significant displacement portends a higher likelihood of nonunion and symptomatic malunion after nonoperative treatment. Surgical fixation has been shown to reduce the rate of these adverse outcomes. However, the benefit of surgery is narrowly defined and the decision to offer operative treatment involves a careful analysis of patient clinical factors, expectations, and concomitant injuries. In North America, fixation is most commonly performed with a precontoured plate and screw construct. Frequently, fracture patterns are amenable to direct reduction and primary bone healing, but the plate may also be used as a bridging construct for comminuted fractures. This video demonstrates the superior approach to clavicular plating. We detail the exposure, reduction, and fixation using lag screws and stabilization with a plate and screw construct.

Inpatient Outcomes in Dialysis-dependent Patients Undergoing Elective Lumbar Surgery for Degenerative Lumbar Disease.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate hospital outcomes in dialysis-dependent patients undergoing elective lumbar surgeries. SUMMARY OF BACKGROUND DATA: Because of their overall poor health status and concomitant comorbidity burden, spinal surgery in dialysis-dependent patients represents a significant challenge to spine surgeons. Large studies evaluating their immediate postoperative outcomes in elective lumbar surgery are lacking. METHODS: Utilizing the National Inpatient Sample, an estimated 1834 dialysis-dependent patients undergoing elective lumbar spine surgery for degenerative lumbar conditions were compared to an estimated 2,522,594 non-dialysis-dependent patients undergoing the same procedures between 2002 and 2012. Our primary outcomes measures included postoperative complication rates, hospital length of stay, and total hospital costs. RESULTS: Mean age of dialysis-dependent patients was 64.2 years compared to 59.9 in the non-dialysis-dependent cohort (P < 0.001). Dialysis-dependent patients had substantially higher inpatient mortality rates (1.8% vs 0.1%; P < 0.001), major complication rates (8.1% vs 1.1%; P < 0.001), and an increased need for blood transfusion (18.3% vs 12.5%; P < 0.001). Multivariate analysis revealed that dialysis dependence independently increased odds of in-hospital mortality (odds ratio = 8.30; 95% confidence interval 5.78-11.93; P < 0.001) and odds of a major postoperative complication (odds ratio = 3.63; 95% confidence interval 3.49-3.89; P < 0.001). Dialysis dependence was associated with an increased mean length of stay of 3.3 days (P < 0.001) and a significant increase in hospital costs when stratified by procedure type. CONCLUSION: Dialysis dependence is associated with poorer immediate postoperative outcomes and increased hospital costs when compared to non-dialysis-dependent patients. In addition, an increased need for postoperative transfusion should be anticipated in this patient population. Further studies are warranted to confirm these findings. LEVEL OF EVIDENCE: 3.

Noninvasive image texture analysis differentiates K-ras mutation from pan-wildtype NSCLC and is prognostic.

BACKGROUND: Non-invasive characterization of a tumor's molecular features could enhance treatment management. Quantitative computed tomography (CT) based texture analysis (QTA) has been used to derive tumor heterogeneity information, and the appearance of the tumors has been shown to relate to patient outcome in non-small cell lung cancer (NSCLC) and other cancers. In this study, we examined the potential of tumoral QTA to differentiate K-ras mutant from pan-wildtype tumors and its prognostic potential using baseline pre-treatment non-contrast CT imaging in NSCLC. METHODS: Tumor DNA from patients with early-stage NSCLC was analyzed on the LungCarta Panel. Cases with a K-ras mutation or pan-wildtype for 26 oncogenes and tumor suppressor genes were selected for QTA. QTA was applied to regions of interest in the primary tumor. Non-parametric Mann Whitney test assessed the ability of the QTA, clinical and patient characteristics to differentiate between K-ras mutation from pan-wildtype. A recursive decision tree was developed to determine whether the differentiation of K-ras mutant from pan-wildtype tumors could be improved by sequential application of QTA parameters. Kaplan-Meier survival analysis assessed the ability of these markers to predict survival. RESULTS: QTA was applied to 48 cases identified, 27 had a K-ras mutation and 21 cases were pan-wildtype. Positive skewness and lower kurtosis were significantly associated with the presence of a K-ras mutation. A five node decision tree had sensitivity, specificity, and accuracy values (95% CI) of 96.3% (78.1-100), 81.0% (50.5-97.4), and 89.6% (72.9-97.0); respectively. Kurtosis was a significant predictor of OS and DFS, with a lower kurtosis value linked with poorer survival. CONCLUSIONS: Lower kurtosis and positive skewness are significantly associated with K-ras mutations. A QTA feature such as kurtosis is prognostic for OS and DFS. Non-invasive QTA can differentiate the presence of K-ras mutation from pan-wildtype NSCLC and is associated with patient survival.

Mechanical strain applied to human fibroblasts differentially regulates skeletal myoblast differentiation.

Cyclic short-duration stretches (CSDS) such as those resulting from repetitive motion strain increase the risk of musculoskeletal injury. Myofascial release is a common technique used by clinicians that applies an acyclic long-duration stretch (ALDS) to muscle fascia to repair injury. When subjected to mechanical strain, fibroblasts within muscle fascia secrete IL-6, which has been shown to induce myoblast differentiation, essential for muscle repair. We hypothesize that fibroblasts subjected to ALDS following CSDS induce myoblast differentiation through IL-6. Fibroblast conditioned media and fibroblast-myoblast cocultures were used to test fibroblasts' ability to induce myoblast differentiation. The coculture system applies strain to fibroblasts only but still allows for diffusion of potential differentiation mediators to unstrained myoblasts on coverslips. To determine the role of IL-6, we utilized myoblast unicultures ± IL-6 (0-100 ng/ml) and cocultures ± α-IL-6 (0-200 µg/ml). Untreated uniculture myoblasts served as a negative control. After 96 h, coverslips (n = 6-21) were microscopically analyzed and quantified by blinded observer for differentiation endpoints: myotubes per square millimeter (>3 nuclei/cell), nuclei/myotube, and fusion efficiency (%nuclei within myotubes). The presence of fibroblasts and fibroblast conditioned media significantly enhanced myotube number (P < 0.05). However, in coculture, CSDS applied to fibroblasts did not reproduce this effect. ALDS following CSDS increased myotube number by 78% and fusion efficiency by 96% vs. CSDS alone (P < 0.05). Fibroblasts in coculture increase IL-6 secretion; however, IL-6 secretion did not correlate with enhanced differentiation among strain groups. Exogenous IL-6 in myoblast uniculture failed to induce differentiation. However, α-IL-6 attenuated differentiation in all coculture groups (P < 0.05). Fibroblasts secrete soluble mediators that have profound effects on several measures of myoblast differentiation. Specific biophysical strain patterns modify these outcomes, and suggest that myofascial release after repetitive strain increases myoblast differentiation and thus may improve muscle repair in vivo. Neutralization of IL-6 in coculture significantly reduced differentiation, suggesting fibroblast-IL-6 is necessary but not sufficient in this process.