Cost Analysis of All-Polyethylene Compared to Metal-Backed Implants in Total Knee Arthroplasty.

INTRODUCTION: The growing trends of total knee arthroplasty (TKA) foreshadow an inevitable increase in the financial burden on healthcare expenditure estimated to almost nine billion dollars annually. This study aims to demonstrate the potential savings when using all-polyethylene (AP) compared to metal-backed (MB) tibial components and describes the cost variability amongst three major commercially available implants. MATERIALS AND METHODS: The cost of AP versus MB implants was analyzed using a large nationwide database, Emergency Care Research Institute (ECRI). Cost of femoral components and patellar buttons were excluded. The three manufacturers included in the study were DePuy, Smith&Nephew, and Stryker (Zimmer data was not available for analysis). RESULTS: Our results show that AP components were significantly less costly in comparison to other manufacturers, and the average AP price was $1,009. The average MB (baseplate plus liner) price was $2,054 (p<0.01). Analysis of variance (ANOVA) of the means of the AP components showed no significant difference in prices among the three studied manufacturers (p=0.946). DISCUSSION: Our results demonstrate that, regardless of the manufacturing company, AP tibial components are significantly cheaper than their MB counterparts. A literature review revealed that, when indicated, AP implants are not inferior to MB in terms of survivorship or outcome. The average savings was more than $1,000 per TKA when multiplied even by a small portion of the large volume of TKAs completed annually. This can translate into millions of dollars in savings in healthcare expenditures. With the impending legislation of the bundled-payment initiative, orthopaedic surgeons should be aware of less costly implant options that can positively impact outcomes and/or quality of care.

Hypoalbuminemia and Elevated CRP are Risk Factors for Deep Infections and Urinary Tract Infections After Lumbar Spine Surgery in a Large Retrospective Patient Population.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVES: To determine if pre-operative albumin and CRP can predict post-operative infections after lumbar surgery. METHODS: Patients who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lumbar discectomy were identified using a patient record database (PearlDiver) and were included in this retrospective study. Patients were stratified by Charlson Comorbidity Index (CCI) scores and pre-operative albumin and CRP status. Post-operative complications included deep infections and urinary tract infections within 3 months of the surgery and revisions within 1 year of the surgery. RESULTS: 74,280 patients were included in this study. 21,903 had pre-operative albumin or CRP lab values. 7,191 (33%), 12,183 (56%), and 2,529 (12%) patients underwent an ALIF, PLIF, and a lumbar discectomy, respectively. 16,191 did not have any complication (74%). The most common complication was UTI (16%). Among all patients, hypoalbuminemia was a significant risk factor for deep infection and UTI after ALIF, deep infection, UTI, and surgical revision after PLIF, and deep infection after lumbar discectomy. Elevated CRP was a significant risk factor for deep infection after ALIF, UTI after PLIF, and deep infection after lumbar discectomy in patients with a CCI ≤ 3. CONCLUSIONS: Pre-operative hypoalbuminemia and elevated CRP were significant risk factors for deep infection, UTI, and/or revision, after ALIF, PLIT, and/or lumbar discectomy. Future studies with a larger population of patients with low albumin and high CRP values are needed to further elaborate on the current findings.

Delayed quadriparesis after posterior spinal fusion for scoliosis: a case series.

STUDY DESIGN: A multicenter retrospective IRB exempt case series analyzing clinical and radiographical data of patients treated by three surgeons over the past two decades was conducted. OBJECTIVE: To examine the factors involved in the development of quadriparesis in patients who underwent posterior spinal fusion for scoliosis. Delayed spinal cord infarcts usually present at the region of instrumentation according to reports from the Scoliosis Research Society. Nonetheless, there is a lack of data regarding factors associated with delayed quadriparesis following posterior spinal fusion METHODS: Evaluated variables were age, Cobb angle, blood loss, and curve correction percentage. Postoperative imaging was also evaluated to determine factors indicative of the etiology of the quadriparesis. RESULTS: Eight patients presented delayed postoperative quadriparesis. All patients had a postoperative examination equal to that of baseline. The first patient deteriorated at 6 h postoperatively and the most delayed patient presented 4 days postoperatively. Six patients had neuromuscular disorders and 2 had adolescent idiopathic scoliosis. Mean age was 13.7, mean curve magnitude was 78.7°, mean percent curve correction was 71% and the mean estimated blood loss was 1185 cc. Seven of eight patients had documented peri- or postoperative hypotension. CONCLUSIONS: Cervical infarction is the likely cause of delayed quadriparesis after posterior spinal fusion. Even though the underlying etiology continues to be unclear, postoperative hypotension, curve magnitude, percent curve correction, and the presence of cervical kyphosis/stenosis may be contributory and need to be closely evaluated. LEVEL OF EVIDENCE: IV, Case Series.

The Safety Profile of Percutaneous Minimally Invasive Sacroiliac Joint Fusion.

STUDY DESIGN: Literature review. OBJECTIVES: Systematic review of the existing literature to determine the safety of minimally invasive (MI) sacroiliac (SI) joint fusion through the determination of the rate of procedural and device-related intraoperative and postoperative complications. METHODS: All original studies with reported complication rates were included for analysis. Complications were defined as procedural if secondary to the MI surgery and device related if caused by placement of the implant. Complication rates are reported using descriptive statistics. Random-effects meta-analysis was performed for preoperative and postoperative Visual Analog Score (VAS) pain ratings and Oswestry Disability Index (ODI) scores. RESULTS: Fourteen studies of 720 patients (499 females/221 males) with a mean follow-up of 22 months were included. Ninety-nine patients (13.75%) underwent bilateral SI joint arthrodesis resulting in a total of 819 SI joints fused. There were 91 reported procedural-related complications (11.11%) with the most common adverse event being surgical wound infection/drainage (n = 17). Twenty-five adverse events were attributed to be secondary to placement of the implant (3.05%) with nerve root impingement (n = 13) being the most common. The revision rate was 2.56%. MI SI joint fusion reduced VAS scores from 82.42 (95% confidence interval [CI] 79.34-85.51) to 29.03 (95% CI 25.05-33.01) and ODI scores from 57.44 (95% CI 54.73-60.14) to 29.42 (95% CI 20.62-38.21). CONCLUSIONS: MI SI joint fusion is a relatively safe procedure but is not without certain risks. Further work must be done to optimize the procedure's complication profile. Possible areas of improvement include preoperative patient optimization, operative technique, and use of intraoperative real-time imaging.

Endoscopic Lumbar Surgery: The State of the Art in 2019

This study was aimed to provide a brief historical perspective to facilitate appreciation of current techniques, describe outcomes of endoscopic lumbar surgery relative to those of existing techniques, and identify topics in need of study and future directions for the field of endoscopic lumbar surgery. Using the PubMed database, a comprehensive search was conducted to identify peer-reviewed English language articles pertaining to endoscopic lumbar surgery. Lack of focus on pertinent techniques or lack of outcome measures constituted exclusion criteria. A majority of included articles were published from 2015­2019. A context with which to appreciate the application of endoscopic lumbar techniques is established. An abundance of case series and several recent comparison studies have documented the benefits and potential pitfalls of these methods in the past two decades. The advantages of endoscopic lumbar spine surgery are widely touted to include reduced perioperative morbidity, including blood loss, operative time and immediate postoperative recovery, minimal structural trauma resulting from surgery, generally positive patient report outcome scores and the potential to contain costs. Additional high-quality research assessing outcomes of endoscopic lumbar surgery are certainly needed and currently expected given the rapid expansion of the field in recent years.

The Arrival of Robotics in Spine Surgery: A Review of the Literature.

STUDY DESIGN: Systematic review. OBJECTIVE: The authors aim to review comparative outcome measures between robotic and free-hand spine surgical procedures including: accuracy of spinal instrumentation, radiation exposure, operative time, hospital stay, and complication rates. SUMMARY OF BACKGROUND DATA: Misplacement of pedicle screws in conventional open as well as minimally invasive surgical procedures has prompted the need for innovation and allowed the emergence of robotics in spine surgery. Before incorporation of robotic surgery in routine practice, demonstration of improved instrumentation accuracy, operative efficiency, and patient safety are required. METHODS: A systematic search of the PubMed, OVID-MEDLINE, and Cochrane databases was performed for articles relevant to robotic assistance of pedicle screw placement. Inclusion criteria were constituted by English written randomized control trials, prospective and retrospective cohort studies involving robotic instrumentation in the spine. Following abstract, title, and full-text review, 32 articles were selected for study inclusion. RESULTS: Intrapedicular accuracy in screw placement and subsequent complications were at least comparable if not superior in the robotic surgery cohort. There is evidence supporting that total operative time is prolonged in robot-assisted surgery compared to conventional free-hand. Radiation exposure appeared to be variable between studies; radiation time did decrease in the robot arm as the total number of robotic cases ascended, suggesting a learning curve effect. Multilevel procedures appeared to tend toward earlier discharge in patients undergoing robotic spine surgery. CONCLUSION: The implementation of robotic technology for pedicle screw placement yields an acceptable level of accuracy on a highly consistent basis. Surgeons should remain vigilant about confirmation of robotic-assisted screw trajectory, as drilling pathways have been shown to be altered by soft tissue pressures, forceful surgical application, and bony surface skiving. However, the effective consequence of robot-assistance on radiation exposure, length of stay, and operative time remains unclear and requires meticulous examination in future studies. LEVEL OF EVIDENCE: 4.

Variation in tibial tubercle-trochlear groove measurement as a function of age, sex, size, and patellar instability.

BACKGROUND: The tibial tubercle-trochlear groove (TT-TG) measurement was developed to quantify morphologic abnormalities about the knee associated with patellar instability and to help guide surgical decision making. PURPOSE: To assess variations in TT-TG as a function of patient age and size in a population of patients with patellar instability compared with those with no instability. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: All patients younger than 20 years who underwent surgery for patellar instability from 2010 to 2012 were included in this retrospective study. A total of 180 patients with no history of patellar instability or patellofemoral complaints were used as a control group. The TT-TG was measured on magnetic resonance axial images using the centers of the tibial tubercle and the trochlear groove. Data were normalized based on patient height, weight, body mass index (BMI), and femur width. Alpha was set at P < .05 to declare significance. RESULTS: The average age of the 45 patellar instability patients was 15.4 years (range, 10-18 years), their mean TT-TG was 16.3 mm (range, 6.5-26 mm), and 51% were male. By comparison, the mean age of the control group was 16 years (range, 10-19 years), the mean TT-TG was 11.7 mm (range, 3-22 mm), and 58% were male. The TT-TG and the normalized TT-TG for height, weight, BMI, and femur width were all greater in the patellar instability group compared with the control group (P ≤ .001). Thirty-one percent of patients had a TT-TG greater than 20 mm in the instability group compared with 3% in the control group (P < .05, specificity 97%, sensitivity 31%). The TT-TG was found to increase as a function of height in both groups (r = 0.14, P = .04) and decreased with age only in the instability group (r = -0.3, P = .04). CONCLUSION: An elevated TT-TG is associated with patellar instability both in pediatric and adolescent patients. However, this measurement varies as a function of patient age and height, with each centimeter in height increasing the TT-TG by 0.12. Normalization of TT-TG to patient height may control for size variations and should be undertaken in the work-up and management of patients with patellar instability.

Deep Surgical Site Infection Following 2344 Growing-Rod Procedures for Early-Onset Scoliosis: Risk Factors and Clinical Consequences.

BACKGROUND: Deep surgical site infection may change the course of growing-rod treatment of early-onset scoliosis. Our goal was to assess the effect of this complication on subsequent treatment. METHODS: A multicenter international database was retrospectively reviewed; 379 patients treated with growing-rod surgery and followed for a minimum of two years were identified. Deep surgical site infection was defined as any infection requiring surgical intervention. RESULTS: Forty-two patients (11.1%; twenty-five males and seventeen females) developed at least one deep surgical site infection. The mean age at the initial growing-rod surgery was 6.3 years (range, 0.6 to 13.2 years) and the mean duration of follow-up was 5.3 years (range, 2.2 to 14.3 years). The mean interval between the initial surgery and the first deep surgical site infection was 2.8 years (range, 0.02 to 7.9 years). Ten (2.6%) of the 379 patients developed deep surgical site infection before the first lengthening. Twenty-nine patients (7.7%) developed the infection during the course of the lengthening procedures, and three patients (0.8%) developed it after final fusion surgery. Thirty (13.6%) of 221 patients with stainless-steel implants had at least one deep surgical site infection compared with twelve (8%) of 150 patients with titanium implants (p < 0.05). (The remaining patients were treated with chromium-cobalt implants.) Twenty-two (52.4%) of the forty-two patients with deep surgical site infection underwent implant removal, which was complete in thirteen and partial in nine. Growing-rod treatment was terminated in two patients with partial removal and six patients with complete removal. An increased risk of deep surgical site infection was associated with stainless-steel implants (odds ratio [OR] = 5.7), non-ambulatory status (OR = 2.9), and the number of revisions before the development of deep surgical site infection (OR = 3.3). Neuromuscular etiology and non-ambulatory status increased the possibility of implant removal to treat infection (p < 0.05). CONCLUSIONS: The prevalence of deep surgical site infection associated with growing-rod surgery is higher than that associated with standard pediatric spinal fusion (historical data). Non-ambulatory status, more revisions, and stainless-steel implants increased the risk of deep surgical site infection. After eight surgical procedures, the risk of deep surgical site infection increased to approximately 50%. When patients have implant removal, efforts should be made to retain one longitudinal implant to continue treatment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Are Thoracic Curves With a Low Apex (T11 or T11/T12) Really Thoracic Curves?

STUDY DESIGN: Multicenter; review of prospectively collected data. OBJECTIVES: To determine whether curves with an apex at T11 or T11/T12 represent a combination of thoracic and thoracolumbar curves or constitute their own class of curves. SUMMARY OF BACKGROUND DATA: Curves with an apex at T11 and T11/T12 are classified by the Scoliosis Research Society and Lenke classification as thoracic curves. METHODS: We reviewed 1,835 adolescent idiopathic scoliosis cases from a multicenter database. Based on the most common curve apex levels (thoracic [TH] curves, T9; thoracolumbar/lumbar [TL/L] curves, L1), we created 2 comparison groups that represented classic examples of TH and TL/L curves. We identified 66 cases with an apex at T11-T11/T12 and compared them with 320 cases with a T9 apex, and 126 cases with an L1 apex. We compared characteristics of these 3 groups (p < .05) and completed a radiographic review of the T11-T11/T12 group. RESULTS: The curve direction of the 3 groups was significantly different (TL/L, 84% left; TH, 3% left; and T11-T11/T12, 16% left) (p < .001). The mean number of vertebrae in curves for the T11-T11/T12 group (7.1 ± 1.2) fell between the value for the TL/L (5.7 ± 0.8) and TH (7.3 ± 1.0) groups. The T11-T11/T12 curves had a greater trunk shift than TL/L (p = .002) and TH (p = .011) curves. There was no difference among the 3 groups in terms of major curve Cobb magnitude (p = .09) or age at surgery (p = .76). Radiographic review of the T11-T11/T12 curves revealed 3 curve patterns: 21 long single curves (32%), 28 short single curves (42%), and 17 double thoracic curves (26%). CONCLUSIONS: We suggest caution in lumping curves with an apex at T11 or T11-12 disc together with other thoracic apices in studies involving primary thoracic curves, because some of these curves have features much more typical of thoracolumbar curves.

Breastfeeding and helicobacter pylori infection in children with digestive symptoms.

OBJECTIVE: This study aims to evaluate the role of breastfeeding in the acquisition of Helicobacter pylori (H. pylori) infection in Iran and to compare the histopathologic changes occurring in children feeding on breast milk with those in infants feeding on formula. METHODS: In a case-control study parents of children with and without H. pylori infection who had undergone endoscopic survey and gastric biopsy in the Children's Medical Center, Tehran, were asked about their feeding practices during the first 6 months after birth, the duration of breastfeeding period, the symptoms, and the duration of symptoms and concomitant diseases. FINDINGS: A total of 154 children were included in this study. From this sample, 77 children formed the case group and 77 children formed the control group. A significant difference was found between H. pylori infection and feeding with formula (P=0.045). In case group, a significant difference was found between breastfeeding and age of the infected child (P=0.034), shorter duration of symptoms (P=0.016), and finally degree of H. pylori colonization (P=0.021). CONCLUSION: It appears that breastfeeding in the first 6 months after birth can decrease the degree of H. pylori colonization, postpone infection until older age, shorten the duration of symptoms, and be concomitant with milder gastritis.