Evaluating Changes to the Modified K-Line Using Kinematic MRIs.

STUDY DESIGN: Retrospective cross-sectional review of a large database. OBJECTIVE: Little is known regarding extension K-lines for treatment of cervical myelopathy. Therefore, this study seeks to examine differences between K-lines drawn in neutral and extension. SUMMARY OF BACKGROUND DATA: The modified K-line is a radiological tool used in surgical planning of the cervical spine. As posterior cervical decompression and fusion often results in patients being fused in a more lordotic position than the preoperative neutral radiograph, a K-line measured in the extension position may offer better utility for these patients. MATERIALS AND METHODS: Total of 97 patients were selected with T2-weighted, upright cervical magnetic resonance imaging taken in neutral and extension. For each patient, the K-line was drawn at the mid-sagittal position for both neutral and extension. The distance from the most posterior portion of each disk (between C2 and C7) to the K-line was measured in neutral and extension and the difference was calculated. Paired t test was used to assess significant differences. RESULTS: Across all levels between C2 and C7 there was an increase in the distance between the dorsal aspect of the disk and K-line when comparing neutral and extension radiographs. The average change in difference (extension minus neutral) at each cervical spinal level was 0.9 mm (C2-C3), 2.5 mm (C3-C4), 2.6 mm (C4-C5), 2.0 mm (C5-C6), and 0.9 mm (C6-C7). A paired t test showed that the K-line increase from neutral to extension was statistically significant across all disk levels ( P <0.001). CONCLUSION: When positioned in extension, patients experience a significant increase in distance from the dorsal aspect of a disk to the K-line compared to when positioned in neutral, especially between C3 and C6. This is clinically relevant for surgeons considering a posterior cervical decompression and fusion in patients with a negative modified K-line on preoperative magnetic resonance imaging, as these patients may have enough cervical cord drift back when fused in an extended position, maximizing likelihood of improving postoperative DSM functional outcomes.

Shoulder Balance in Adult Spinal Deformity Patients Undergoing Selective Lumbar Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: To analyze if shoulder balance continues to change in the postoperative period in patients undergoing selective lumbar fusion for adult spinal deformity (ASD), and secondarily, analyze if shoulder balance correlates with health-related quality of life (HRQOL) outcomes. SUMMARY OF BACKGROUND DATA: Shoulder balance in patients with ASD is poorly understood and has largely been extrapolated from adolescent scoliosis literature. MATERIALS AND METHODS: Adult patients who underwent selective lumbar fusion (upper instrumented vertebra: Τ9-Τ12, lower instrumented vertebra: L4-Pelvis) for thoracolumbar or lumbar scoliosis (cobb angle > 30°) or sagittal plane deformity with thoracic compensatory curves (cobb angle > 10°) were identified. The clavicular angle (CA) was used to quantify shoulder balance. Shoulder balance was categorized into three groups postoperatively (balanced: CA <2°, mild imbalance: CA 2°-4°, severe imbalance: CA >4°). The average CA and proportion of patients in each shoulder balance group were compared at each postoperative period. Patients with 1-year postoperative HRQOL scores were identified. RESULTS: Eighty-six patients were included. The preoperative CA was 2.7 ±â€Š2.3° and did not significantly change at discharge (2.9 ±â€Š2.4°), 6-weeks (2.5 ±â€Š2.1°), 6-months (2.4 ±â€Š2.2°), 1-year (2.4 ±â€Š2.5°), or 2-years (2.3 ±â€Š1.5°) postoperatively. The proportion of patients in each shoulder balance group did not significantly change from discharge to 6-weeks, 6-months, 1-year or 2-years postoperatively (P > 0.1). At 1-year follow-up, the CA demonstrated no significant correlation with Oswestry Disability Index, Scoliosis Research Society (SRS)-22 score, or SRS-22 subscores. There was no significant association between shoulder balance group and Oswestry Disability Index, SRS-22 score, or SRS-22 subscores. CONCLUSIONS: In patients with ASD undergoing selective lumbar fusion, shoulder balance did not change over the postoperative period. From a functional standpoint, shoulder balance demonstrated no correlation with HRQOL scores. In patients undergoing selective lumbar fusion for ASD, shoulder balance may not spontaneously correct over the postoperative period, but this may not be of functional consequence.Level of Evidence: 4.

Anterior Cervical Discectomy and Fusion Versus Cervical Disc Replacement in Patients With Significant Cervical Spondylosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim was to compare clinical outcomes in patients with significant cervical spondylosis treated with cervical disc replacement (CDR) compared with anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: As CDR utilization has increased over the past decade, recent studies have investigated the outcomes of CDR in patients with more significant spondylotic changes and demonstrated improved postoperative patient-reported outcomes (PROs). However, no prior study has investigated clinical outcomes of patients with significant spondylotic changes treated with CDR in comparison to ACDF. METHODS: Patients who underwent 1-level or 2-level CDR or ACDF with significant cervical spondylosis, quantified using a validated grading scale, were identified, and prospectively collected data was retrospectively reviewed. The following PROs were analyzed: Neck Disability Index (NDI), visual analog scale-Neck, visual analog scale-Arm, and PROMIS Physical Function (PROMIS-PF) Computer Adaptive Test Score. Demographic, operative, and radiographic variables, and achievement of minimum clinically important difference (MCID) for each PRO were compared between the 2 groups. RESULTS: A total of 66 patients were included in the present study, of which 35 (53%) were treated with CDR and 31 (47%) with ACDF. The preoperative cervical spondylotic grade was similar between the 2 groups (1.8 vs. 2.2, P=0.27). At final follow-up, there was no significant difference in the absolute value for each PRO between the 2 groups (P>0.19) and both groups demonstrated significant improvement in each PRO compared with preoperative values (P<0.01). There was no significant difference in the percentage of patients achieving the MCID for each PRO when comparing CDR to ACDF (P>0.09). CONCLUSIONS: A similar percentage of patients with significant degenerative cervical spondylosis achieved the MCID across multiple PROs when treated with CDR or ACDF. Patients in both treatment groups demonstrated significant improvement in all PROs assessed when compared with preoperative values. LEVEL OF EVIDENCE: Level III.

Single Versus Dual Headless Compression Screw Fixation of Scaphoid Nonunions: A Biomechanical Comparison.

BACKGROUND: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. METHODS: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. RESULTS: Stiffness during load to failure was not significantly different between single- and double-screw configurations (P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct (P = .029). CONCLUSIONS: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

A Survey to Assess Agreement Between Pelvic Surgeons on the Outcome of Examination Under Anesthesia for Lateral Compression Pelvic Fractures.

OBJECTIVES: To assess agreement among pelvic surgeons regarding the interpretation of examination under anesthesia (EUA), the methodology by which EUA should be performed, and the definition of a positive examination. DESIGN: Survey. PATIENTS/PARTICIPANTS: Ten patients who presented to our Level 1 trauma center with a pelvic ring injury were selected as clinical vignettes. Vignettes were distributed to 15 experienced pelvic surgeons. INTERVENTION: Examination under anesthesia. MAIN OUTCOME MEASUREMENTS: Agreement regarding pelvic fracture stability (defined as >80% similar responses), need for surgical fixation, definition of an unstable EUA, and method of performing EUA. RESULTS: There was agreement that a pelvic fracture was stable or unstable in 8 (80%) of 10 cases. There was agreement that fixation was required or not required in 6 (60.0%) of 10 cases. Seven (46.7%) surgeons endorsed performing a full 15-part EUA, whereas the other 8 (53.3%) used an abbreviated or alternative method. Eight (53.3%) surgeons provided a definition of what constitutes a positive EUA, whereas the remaining 7 did not endorse adhering to a strict definition. CONCLUSIONS: Pelvic surgeons generally agree on what constitutes a positive or negative EUA but not necessarily the implications of a positive or negative examination. There is no clear consensus among surgeons regarding the method of performing EUA nor regarding the definition of a positive EUA. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Risk Factors and Complications Following Arthroscopic Tenotomy of the Long Head of the Biceps Tendon.

BACKGROUND: Controversy exits regarding performing a tenotomy versus a tenodesis of the long head of the biceps tendon (LHBT). PURPOSE: To evaluate the complications after arthroscopic tenotomy of the LHBT and characterize the incidence of cosmetic deformity, cramping, subjective weakness, and continued anterior shoulder pain (ASP). Additionally, to identify patient-related factors that may predispose a patient to these complications. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Records of patients who underwent an arthroscopic LHBT tenotomy at an integrated health care system under the care of 55 surgeons were retrospectively reviewed. Exclusion criteria included LHBT tenodesis, arthroplasty, neoplastic, or fracture surgery; age younger than 18 years; incomplete documentation of physical examination; or incomplete operative reports. Characteristic data, concomitant procedures, LHBT morphology, and postoperative complications were recorded. Patients with and without postoperative complications-including cosmetic deformity, subjective weakness, continued ASP, and cramping-were analyzed by age, sex, dominant arm, body mass index (BMI), smoking status, workers' compensation status, and intraoperative LHBT morphology to identify risk factors for developing these postoperative complications. RESULTS: A total of 192 patients who underwent LHBT tenotomy were included in the final analysis. Tenotomy was performed with concomitant shoulder procedures in all but 1 individual. The mean ± SD patient age was 60.6 ± 9.5 years, and 55% were male. The overall complication rate was 37%. The most common postoperative complications include cosmetic (Popeye) deformity (14.1%), subjective weakness (10.4%), cramping (10.4%), and continued postoperative ASP over the bicipital groove (7.8%). Every 10-year increase in age was associated with 0.52 (95% CI, 0.28-0.94) times the odds of continued ASP and 0.59 (95% CI, 0.36-0.98) times the odds of cramping pain. Male patients had 3.9 (95% CI, 1.4-10.8) times the odds of cosmetic (Popeye) deformity. Patients who had active workers' compensation claims had 12.5 (95% CI, 2.4-63.4) times the odds of having continued postoperative ASP. Tenotomy on the dominant arm, BMI, and active smoking status demonstrated no statistically significant association with postoperative complications. CONCLUSION: Patients experiencing complications after tenotomy were significantly younger and more likely to be male and to have a workers' compensation injury. LHBT tenotomy may best be indicated for elderly patients, female patients, and those without active workers' compensation claims.

Review of Internal Radiocarpal Distraction Plating for Distal Radius Fracture Fixation.

Internal radiocarpal distraction plating is a versatile tool in the treatment of distal radius fractures that are not amenable to nonoperative treatment or operative fixation with standard volar or dorsal implants. Internal distraction plates may also be indicated in the setting of polytrauma or osteopenic bone. The plate functions as an internal fixator, using ligamentotaxis to restore length and alignment while providing relative stability for bony healing. The plate can be fixed to either the second or the third metacarpal, and anatomic and biomechanical studies have assessed the strengths and weaknesses of each strategy. This operative fixation technique leads to acceptable radiographic results and functional outcomes. Following fracture union, the plate is removed, and wrist range of motion is resumed.

Increasing Rate of Surgical Fixation in Four- and Five-year-old Children With Femoral Shaft Fractures.

BACKGROUND: The purpose of this study was to identify temporal trends in the management of pediatric femoral shaft fractures in 4- and 5-year-old children. METHODS: The Kids' Inpatient Database was used to extract data on patients aged 4 and 5 years with closed femoral shaft fractures. The frequency of nonsurgical and surgical management was calculated, and temporal trends were evaluated. RESULTS: Between 1997 and 2012, the absolute increase in surgical fixation was 35% and 58% in 4- and 5-year-old patients, respectively. The surgical rate increased every 3 years by 13.8% in 4-year-old patients and 7.6% in 5-year-old patients. Significant associations were noted based on demographics, comorbidities, and hospital characteristics with management decisions. CONCLUSIONS: A clear and significant increase was noted in internal fixation for pediatric femoral shaft fractures in 4- and 5-year-old children, and the lower age limit for surgical management of these fractures is decreasing. LEVEL OF EVIDENCE: Level III. Retrospective comparative study.

Effect of Insurance on Rates of Total Ankle Arthroplasty Versus Arthrodesis for Tibiotalar Osteoarthritis.

BACKGROUND: Several studies have examined the effect of insurance on the management of various orthopedic conditions. The purpose of our study was to assess the effect of insurance and other demographic factors on the operative management of tibiotalar osteoarthritis. METHODS: The National Inpatient Sample (NIS) database was used to identify patients who underwent a total ankle arthroplasty (TAA) or tibiotalar arthrodesis (TTA) for tibiotalar osteoarthritis. Insurance status was identified for each patient, and the proportions of each insurance type were computed for each operative modality. A multivariate analysis was performed to account for confounding variables to isolate the effect of insurance type on operative treatment. RESULTS: From 2007 to 2012, a total of 10 010 patients (35.6%) were identified who underwent a total ankle replacement (TAR) procedure and 18 094 patients (64.4%%) who underwent TTA for tibiotalar osteoarthritis. Patients receiving a TAR were older (65.8 vs 64.2, P < .001), more likely to be female (54% vs 51%, P < .001), and had fewer comorbidities (4.2 vs 4.5, P < .001) than patients who underwent a TTA. After controlling for baseline differences, patients with Medicare (odds ratio [OR] 3.00, P < .001), and private insurance (OR 3.19, P < .001) were approximately 3 times more likely to undergo TAR than patients with Medicaid. CONCLUSIONS: Patients with tibiotalar osteoarthritis were more likely to receive a TAR procedure if they had Medicare or private insurance compared with patients who had Medicaid. Further research should be done to better understand the drivers of this phenomenon if equitable care is to be achieved. LEVEL OF EVIDENCE: Level II, prognostic study.

A randomized controlled trial of high-fidelity simulation versus lecture-based education in preclinical medical students.

PURPOSE: The purpose of this study was to compare the efficacy of simulation versus lecture-based education among preclinical medical students. METHODS: Twenty medical students participated in this randomized, controlled crossover study. Students were randomized to four groups. Each group received two simulations and two lectures covering four different topics. Students were administered a pre-test, post-test and delayed post-test. The mean percentage of questions answered correctly on each test was calculated. The mean of each student's change in score across the three tests was used to compare simulation- versus lecture-based education. RESULTS: Students in both the simulation and lecture groups demonstrated improvement between the pre-test and post-test (p < 0.05). Students in the simulation group demonstrated improvement between the immediate post-test and delayed post-test (p < 0.05), while students in the lecture group did not demonstrate improvement (p > 0.05). When comparing interventions, the change in score between the pre-test and post-test was similar among both the groups (p > 0.05). The change in score between the post-test and delayed post-test was greater in the simulation group (p < 0.05). CONCLUSIONS: High-fidelity simulation may serve as a viable didactic platform for preclinical medical education. Our study demonstrated equivalent immediate knowledge gain and superior long-term knowledge retention in comparison to lectures.