Effects of Acetabular Screws on the Initial Stability of Porous Coated Acetabular Implants in Revision Total Hip Arthroplasty.

INTRODUCTION: Revision total hip arthroplasty in the setting of acetabular bone loss remains a challenging clinical entity. Deficiencies of the acetabular rim, walls, and/or columns may limit the bony surface area and initial acetabular construct stability necessary for osseointegration of cementless components. Press-fit acetabular components with supplemental acetabular screw fixation represent a common technique aimed to minimize implant micromotion and allow for definitive osseointegration. Although acetabular screw fixation is commonly practiced in revision hip arthroplasty, few studies to date have examined the screw properties associated with maximal acetabular construct stability. The purpose of the present report is to examine acetabular screw fixation in a pelvis model mimicking Paprosky IIB acetabular bone loss. METHODS: Measuring bone-implant interface micromotion as a surrogate for initial implant stability, experimental models assessed the effect of screw number, screw length, and screw position on construct stability subject to a cyclic loading protocol designed to replicate joint reaction forces of two common daily activities. RESULTS: Trends towards increasing stability were demonstrated with increasing screw number, increasing screw length, and concentrating screws in the supra-acetabular dome. All experimental constructs yielded micromotion levels sufficient for bone ingrowth, except when screws in the dome were moved to the pubis and ischium. CONCLUSIONS: When using a porous coated revision acetabular implant to treat Paprosky IIB defects, screws should be used, and furthermore, increasing number, length, and position within the acetabular dome may help further stabilize the construct.

Civilian Gun Shot Wounds Associated With Spinal Injuries.

STUDY DESIGN: Retrospective. OBJECTIVE: To evaluate functional outcomes and characteristics associated with gunshot wound (GSW) to the spine. METHODS: Patients with GSW to the spine managed at a Level 1 Trauma Center from January 2003 to December 2017 were enrolled. Patient demographics, diagnoses, level of injury, American Spinal Injury Association (ASIA) score, ambulatory status at follow-up, bowel and bladder function, clinical improvement, and mortality were evaluated. Clinical improvement was defined as a progression in ambulatory status category at latest follow up. RESULTS: 51 patients with GSW of the spine were identified. 48 (94.1%) were male and 3 (5.9%) were female, with a mean age of 27 years-old (range 15-56). 38 (74.5%) were Caucasian, 7 (13.7%) were African American, 1 (2.0%) Asian-American, and 5 (9.8%) were Other/Unknown. 46 (90.2%) patients had GSW related spinal fractures and 44 (86.3%) had neurological deficits. Among patients with neurologic deficits, 5 (9.8%) had Cauda Equina Syndrome, 1 (2%) had Brown-Sequard Syndrome, and 38 (74.5%) spinal cord injuries: ASIA A 26 (68.4%); ASIA B 3 (7.9%); ASIA C 7 (18.4%); ASIA D 2 (5.3%). At mean follow-up time of 4.2 years (SD 3.9), 27 (52.9%) patients were wheelchair bound, 11 (21.6%) were ambulating with assistance, and 13 (25.5%) had normal ambulation. ASIA grade (A or B) was significantly, P < 0.00001, associated with being wheelchair bound and having neurogenic bowel or bladder at follow-up. CONCLUSIONS: Most spinal GSW patients (70.6%) did not have any clinical improvement in ambulatory status and most injuries were ASIA A.

Readability of the Most Commonly Accessed Online Patient Education Materials Pertaining to Surgical Treatments of the Spine.

OBJECTIVE: The American Medical Association and National Institutes of Health have recommended that patient education materials should be written at the sixth-grade reading level to maximize patient comprehension. The objective of the present study was to evaluate the readability of Internet information for the 9 most common spinal surgeries. METHODS: We reviewed 90 online patient educational materials regarding the 9 most common spinal surgeries as reported by the North American Spine Society. A Google search was performed on March 23, 2019 for each surgery, and the top 10 most visited websites for each surgery were assessed for reading level using the Flesch-Kincaid formula. RESULTS: Using the Flesch-Kincaid formula, the average grade reading level of the 90 websites included was 12.82, with a reading ease of 37.04 ("difficult college"). Only 6 websites relayed information to patients at or below the national average of an eighth-grade reading level. The websites for bone morphogenic protein had the highest average grade reading level at 15.88 ± 2.6. Lumbar microscopic discectomy had the lowest average grade reading level at 10.37 ± 2.89. All surgical options discussed had an average readability above the recommended sixth-grade reading level. CONCLUSIONS: The most accessed online materials for common spinal surgeries, not only exceeded the readability limits recommended by both the American Medical Association and the National Institutes of Health, but they also exceeded the average reading ability of most adults in the United States. Patients, therefore, might not fully comprehend the information from commonly accessed websites regarding surgical spine treatment options.

Bone morphogenic protein-2 signaling in human disc degeneration and correlation to the Pfirrmann MRI grading system.

BACKGROUND CONTEXT: Back and neck pain secondary to disc degeneration is a major public health burden. There is a need for therapeutic treatments to restore intervertebral disc (IVD) composition and function. PURPOSE: To quantify ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression in IVD specimens collected from patients undergoing surgery for disc degeneration, to correlate ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression in IVD specimens to the 5-level Pfirrmann MRI grading system, and to compare ALK3, BMP-2, pSMAD1/5/8 and MMP-13 expression between cervical and lumbar degenerative disc specimens. STUDY DESIGN: An immunohistochemical study assessing ALK3, BMP-2, pSMAD1/5/8, and MMP-13 expression levels in human control and degenerative IVD specimens. METHODS: Human IVD specimens were collected from surgical patients who underwent discectomy and interbody fusion at our institution between 1/2015 and 8/2017. Each patient underwent MRI prior to surgery. The degree of disc degeneration was measured according to the 5-level Pfirrmann MRI grading system. Patients were categorized into either the 1) control group (Pfirrmann grades I-II) or 2) degenerative group (Pfirrmann grades III-V). Histology slides of the collected IVD specimens were prepared and immunohistochemical staining was performed to assess ALK3, BMP-2, pSMAD1/5/8, and MMP-13 expression levels in the control and degenerative specimens. Expression levels were also correlated to the Pfirrmann criteria. Lastly, the degenerative specimens were stratified according to their vertebral level and expression levels between the degenerative lumbar and cervical discs were compared. RESULTS: Fifty-two patients were enrolled; however, 2 control and 2 degenerative patients were excluded due to incomplete data sets. Of the remaining 48 patients, there were 12 control and 36 degenerative specimens. Degenerative specimens had increased expression levels of BMP-2 (p=.0006) and pSMAD1/5/8 (p<.0001). Pfirrmann grade 3 (p=.0365) and grade 4 (p=.0008) discs had significantly higher BMP-2 expression as compared to grade 2 discs. Pfirrmann grade 4 discs had higher pSMAD1/5/8 expression as compared to grade 2 discs (p<.0001). There were no differences in ALK3 or MMP-13 expression between the control and degenerative discs (p>.05). Stratifying the degenerative specimens according to their vertebral level showed no significant differences in expression levels between the lumbar and cervical discs (p>.05). CONCLUSIONS: BMP-2 and pSMAD1/5/8 signaling activity was significantly upregulated in the human degenerative specimens, while ALK3 and MMP-13 expression were not significantly changed. The expression levels of BMP-2 and pSMAD1/5/8 correlate positively with the degree of disc degeneration measured according to the Pfirrmann MRI grading system. CLINICAL SIGNIFICANCE: BMP-SMAD signaling represents a promising therapeutic target to restore IVD composition and function in the setting of disc degeneration.

Evaluating Social Media Use Among Active American Members of the Cervical Spine Research Society.

STUDY DESIGN: Observational study. OBJECTIVES: The objectives of this study are (1) to quantify social media use among active American Cervical Spine Research Society (CSRS) members; (2) to determine if there is an association between practice setting, region, or years of active membership and social media use. SUMMARY OF BACKGROUND DATA: Many patients now seek health and physician information online, including on social media. Indeed, social media use by orthopedic surgeons has been shown to be associated with more and improved ratings on physician review websites. Further, social media can provide a means for improved doctor-patient relationships, educational endeavors, and professional networking. However, there is a paucity of literature examining social media use among spine surgeons. MATERIALS AND METHODS: In January 2019, the CSRS membership directory was used to identify all active American spine surgeon members. Through a Google search, social media use of each spine surgeon on the following platforms was identified: provider page/official website; Facebook; Twitter; Instagram; LinkedIn; and YouTube. In addition, surgeon characteristics were recorded. The percentage of spine surgeons using each social media platform was reported. Bivariate analysis was used to compare social media use by practice setting, region, and years of active CSRS membership. RESULTS: Nearly all spine surgeons have a provider page/official website (98%) and over half (56%) have a LinkedIn presence. Less than one third of spine surgeons are on any of the remaining social media platforms analyzed. The least frequently used social media platform was Instagram (3.2%). There was no difference in any social media platform use by practice setting, region, and years of active CSRS membership. CONCLUSIONS: As social media becomes even more common place and the role of it in medical care continues to be better defined, there is notable room for increased social media use among active American members of the CSRS. LEVEL OF EVIDENCE: Level IV-observational study.

Do Surgical Site Infection Rates Differ Among Microscope-assisted Versus Loupe-assisted Lumbar Discectomies?

STUDY DESIGN: Retrospective study. OBJECTIVE: The objective of this study was to compared surgical site infection (SSI) rates between patients under lumbar discectomy with an operative microscope versus surgical loupes. SUMMARY OF BACKGROUND DATA: Lumbar decompressions for herniated disks or lumbar stenosis are common spine procedures. Some studies have raised the concern that drape contamination of the operative microscope may be an additional risk for SSIs. We hypothesize that the use of the operative microscope for lumbar decompression procedures does not increase infection rates. METHODS: A retrospective cohort analysis was performed on patients undergoing lumbar spinal decompressions via microscopic assistance (MA) or loupe assistance (LA) by 2 orthopedic spine surgeons at a tertiary academic medical center. Patients treated from November, 2012 to October, 2016 were enrolled. Variables including age, sex, race, body mass index, smoking status, length of surgery, intraoperative complications, estimated blood loss, and postoperative SSIs within 30 days were collected. RESULTS: A total of 225 patients were included in the study. Sixty-three patients underwent LA lumbar decompression, and 162 underwent MA lumbar decompression. There were 72 female individuals/90 male individuals in the MA group and 31 female individuals/33 male individuals in the LA group. The MA was significantly older 45.2 versus 40.4 in LA, P-value of 0.02 and had a significantly higher body mass index (30.64 vs. 27.79, P<0.002). SSI rates were not significantly different, MA 3.7% (6/162) and LA 7.9% (5/63), P-value of 0.14. The MA group had a significantly longer operative time (92 vs. 50 min, P<0.001). Dural tears rates were 3.1% in MA and 1.6% in LA, P-value of 0.3 and were associated with longer operative time in the MA group, 162.2 versus 90.2 minutes, P-value of <0.0001. Multivariate regression analysis did not identify any significant differences between the 2 groups. CONCLUSIONS: The use of the operative microscope had similar infection rates as LA microdiscectomies. In academic institutions, the operative microscope may allow more opportunities for residents or fellows to partake/assist in the procedure as compared with LA procedures.

Pharmacological mechanisms involved in the analgesia induced by ethanol extract of Hybanthus enneaspermus leaves.

BACKGROUND: Hybanthus enneaspermus (HE) leaves are being used traditionally to relieve pain, and scientific studies have demonstrated their analgesic potential. This study attempted to elucidate the pharmacological mechanism(s) involved in the analgesic action of ethanol extract of H. enneaspermus leaves (EEHE). MATERIALS AND METHODS: Forty-two male Wistar rats were separately randomized into seven groups (n=6 rats in each group) for tail immersion and formalin tests. Group I (control) received distilled water (10 mL/kg) while groups II and III received acetaminophen (the reference drug, 100 mg/kg ip) and EEHE (1000 mg/kg po), respectively. Groups IV-VII were pretreated with cimetidine (50 mg/kg ip), naloxone (5 mg/kg ip), propranolol (0.15 mg/kg ip), and prazosin (0.15 mg/kg ip), respectively, 1 hour before EEHE (1000 mg/kg po) treatment. RESULTS: The EEHE-induced increase in tail-flick latency was reduced by blockade of histamine and adrenergic receptors but prevented by blockade of opiate receptor in the tail-flick test. However, the EEHE-induced decrease in paw licking time was prevented only by blockade of opiate receptor but unaffected by histamine and adrenergic receptors blockers. CONCLUSION: These findings suggest that the analgesic effect of EEHE in different pain types may involve different neural mechanisms and that the opioidergic pathway contributes more to EEHE-induced analgesia than the other pathways.