Eccentric Hamstring Strength Imbalance among Football and Soccer Athletes

OBJECTIVES

Hamstring strain injuries (HSI) are common among football and soccer athletes. Eccentric strength imbalance is considered a contributing factor for HSI. There is, however, a paucity of data on hamstring imbalances of soccer and American football athletes as they age and advance in skill level. High school athletes will display greater interlimb discrepancies compared with collegiate and professional athletes. In addition, soccer athletes will exhibit greater hamstring asymmetry than American football athletes.

METHODS

Hamstring testing was performed on soccer and American football athletes using the NordBord Hamstring Testing System (Vald Performance, Albion, Australia). Age, sex, weight, sport specialization, and sport level were recorded. Maximum hamstring forces (N), torque (N · m), and work (N · s) were measured. Hamstring imbalance (%) was calculated by dividing the absolute value of the difference in leg forces divided by their sum. One-way analysis of variance and independent sample t tests compared measurements between athlete groups.

RESULTS

A total of 631 athletes completed measurements, including 88 high school male soccer, 25 college male soccer, 23 professional male soccer, 83 high school female soccer, 28 college female soccer, 288 high school football, and 96 college football athletes. High school soccer players displayed significantly greater imbalances for torque (P = 0.03) and work (P < 0.01) than football athletes. Imbalances for maximum force (P = 0.035), torque (P = 0.018), and work (P = 0.033) were significantly higher for male soccer athletes in high school compared with college- and professional-level athletes. Female high school soccer players had significantly higher imbalance in torque (P = 0.045) and work (P = 0.001) compared with female collegiate soccer players. Football athletes did not experience significant changes in force imbalances between skill levels.

CONCLUSIONS

High school soccer athletes exhibit greater hamstring imbalances than football athletes. Higher levels of play in soccer, for both male and female athletes, correlate with less hamstring asymmetry.

Suspensory fixation for bone transfer procedures in shoulder instability is superior to screws in an angled construct: a biomechanical analysis

Background

The Latarjet procedure is a common bony augmentation procedure for anterior shoulder instability. Historically, screw fixation is used to secure the coracoid graft to the anterior glenoid surface; however, malpositioning of the graft leads to oblique screw insertion that contributes to complications. Suture buttons (SBs) are a more recent fixation technique that have not been studied alongside standard screw fixation in the context of biomechanical models of angulated fixation. This study aims to compare the biomechanical strength of single and double, screw and SB fixation at various levels of angulation.

Methods

Testing was performed using polyurethane models from Sawbones. The graft piece was secured with screw fixation (Arthrex, Naples, FL, USA) or suspensory button (ABS Tightrope, Arthrex, Naples, FL, USA). Single or double constructs of screws and SBs were affixed at 0°, 15°, and 30° angles to the face of the glenoid component. An aluminum testing jig held the samples securely while a materials testing system applied loads. Five constructs were used for each condition and assessed load to failure testing.

Results

For single fixation constructs, suspensory buttons were 60% stronger than screws at 0° (P < .001), and 52% stronger at 15° (P = .004); however, at 30°, both were comparable (P = .180). Interestingly, single suspensory button at 15° was equivalent to a single screw at 0° (P = .310). For double fixation, suspensory buttons (DT) were 32% stronger than screws at 0° (P < .001) and 35% stronger than screws at 15° (P < .001). Both double fixation methods were comparable at 30° (P = .061). Suspensory buttons at 15° and 30° were equivalent to double screws at 0 (P = .280) and 15° (P = .772), respectively.

Conclusion

These measurements indicate that the suspensory button has a significantly higher load to failure capacity over the screw fixation technique, perpendicularly and with up to 15° of angulation. These analyses also indicate that the suspensory button fixation offers superior strength even when positioned more obliquely than the screw fixation. Therefore, suspensory button fixation may confer more strength while offering greater margin for error when positioning the graft.

Patient Self-Reported Allergies and Their Correlation with Thoracic Outlet Syndrome Outcomes

OBJECTIVES

Thoracic outlet syndrome (TOS) is an uncommon neurovascular disorder that presents as neck and upper extremity pain secondary to brachial plexus trunk or subclavian vasculature compression. The orthopedic literature has correlated patient-reported allergies to postoperative patient-reported outcome (PRO) scores for a variety of surgical procedures. We sought to evaluate patient-reported allergies and PROs following surgical decompression for TOS.

METHODS

A chart review was conducted after identifying patients who underwent surgical thoracic outlet decompression by a single surgeon. Patients were contacted and administered five PRO questionnaires via telephone: the QuickDASH Outcome Measure questionnaire (disabilities of the arm, shoulder, and hand [DASH]), the Cervical Brachial Symptom Questionnaire, the Single Assessment Numeric Evaluation, the 12-Item Short Form Survey, and the Numeric Rating Scale (a visual analogue scale). A bivariate analysis of Pearson's correlation coefficient (r) was used to determine the associations of allergies with questionnaires and demographic variables.

RESULTS

Of the 393 patients (128 males and 265 females) identified in the study, 75 (24%) responded and completed all of the questionnaires, 18 (24%) males and 57 (76%) females. A significant correlation was found between the number of allergies reported and the QuickDASH Outcome Measure questionnaire (r = 0.375, P < 0.001), the Cervical Brachial Symptom Questionnaire (r = 0.295, P = 0.01), change in the Single Assessment Numeric Evaluation score (r = -0.310, P < 0.01), change in the visual analogue scale (r = 0.244, P = 0.035), sex (r = 0.245, P = 0.034), and the number of medications (r = 0.642, P < 0.001).

CONCLUSIONS

The increased frequency of patient-reported allergies is significantly associated with worse PRO scores for women undergoing TOS surgical decompression. Better understanding this association can help physicians counsel patients on expected outcomes.

Comparing the Intensity of Pain and Incidence of Flare Reaction Following Trigger Finger Injections Using Betamethasone and Methylprednisolone: A Double-Blinded, Randomized Controlled Trial

BACKGROUND

Considerable evidence supports corticosteroid injection as an effective treatment for trigger finger. One common side effect, the flare reaction, is a well-documented phenomenon of increased pain following steroid injections. Its incidence and intensity may be related to steroid composition. The purpose of this study was to determine whether betamethasone and methylprednisolone injections for trigger fingers have differing intensity of pain or incidence flare reaction.

METHODS

Patients with symptomatic trigger finger were recruited during their hand surgery visits. Patients were randomized into 2 treatment groups: betamethasone (40 mg) and methylprednisolone (6 mg) mixed with lidocaine 1%. Treatment group assignment was blinded to the patients and investigators. Visual analog scale pain measurements were taken prior to injection, 5 minutes postinjection, and daily thereafter for 7 days.

RESULTS

Sixty-four patients were randomized into the 2 treatment groups. Patients in the betamethasone group reported slightly higher baseline pain compared with the methylprednisolone group, but lower pain on day 1. None of the following days showed a statistically significant difference.

CONCLUSIONS

The incidence of flare and severe flare reactions of betamethasone injections for trigger finger management was roughly double that of methylprednisolone, but this difference was not statistically significant. Further studies are required to evaluate the relative course of nonflare postinjection pain for different corticosteroid injections for trigger finger injections.

Orthopedic consequences of modern gladiators: a systematic review of lower extremity musculoskeletal issues in retired NFL players

OBJECTIVES

The stressors that National Football League (NFL) athletes face are well-described and documented with regard to multisystem afflictions and injury prevalence. However, the majority of literature discusses the short-term effects rather than long-term outcomes of playing professional football. The purpose of this study was to characterize the long-term musculoskeletal issues in the retired NFL population.

METHODS

Publications from CENTRAL, Scopus, Medline, PubMed, Embase, and Google Scholar were searched from database inception to February 2021. A total of 9 cohort studies evaluating lower extremity arthritis in retired NFL athletes were included for review. Two reviewers extracted data from the individual studies, including demographic information (age, body mass index, length of career, position), injury descriptions (location of injury, number of injuries, diagnoses), and procedure (total knee and or hip arthroplasty) frequency.

RESULTS

Arthritis in retired NFL players was more than twice as prevalent than the general United States male population (95% CI: 2.1-2.3). Ankle osteoarthritis was directly correlated with the number of foot and ankle injuries. Players <50 years of age had a 16.1 and 13.8 times higher risk of undergoing TKA and THA, respectively, when compared to the general population. In older age groups, this trend held with retired NFL players being at least 4.3 and 4.6 times more likely than members of the general population to undergo TKA and THA, respectively.

CONCLUSION

This review demonstrates that the effects of NFL-related lower extremity injuries extend beyond the players' careers and present a higher risk for early-onset osteoarthritis and overall frequency of undergoing total knee and hip arthroplasty.

A Systematic Review of Screw and Suture Button Glenoid Augmentation Constructs

Background

Glenohumeral dislocations often lead to glenoid bone loss and recurrent instability, warranting bony augmentation. While numerous biomechanical studies have investigated fixation methods to secure a graft to the glenoid, a review of available constructs has yet to be performed.

Purpose

To synthesize the literature and compare the biomechanics of screw and suture button constructs for anterior glenoid bony augmentation.

Study Design

Systematic review.

Methods

A systematic review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. There were 2 independent reviewers who performed a literature search using the PubMed, Embase, and Google Scholar databases of studies published between 1950 and 2020. Studies were included that compared the biomechanical outcomes of fixation for the treatment of anterior shoulder instability with glenoid bone loss.

Results

Overall, 13 of the 363 studies screened met the inclusion criteria. The included studies measured the biomechanical strength of screws or suture buttons on a cadaveric or synthetic Latarjet construct. Screws and suture buttons were biomechanically similar, as both constructs exhibited comparable loads at failure and final displacement. Screw type (diameter, threading, or composition) did not significantly affect construct strength, and double-screw fixation was superior to single-screw fixation. Additionally, 2 screws augmented with a small plate had a higher load at failure than screws that were not augmented. Unicortical double-screw fixation was inferior to bicortical double-screw fixation, although construct strength did not significantly decrease if 1 of these screws was unicortical. Further, 2 screws inserted at 15° off axis experienced significantly higher graft displacement and lower ultimate failure loads than those inserted at 0° parallel to the glenoid.

Conclusion

Suture buttons provided comparable strength to screws and offer an effective alternative to reduce screw-related complications. Augmentation with a small plate may clinically enhance construct strength and decrease complications through the dispersion of force loads over a greater surface area. Differences in screw type did not appear to alter construct strength, provided that screws were placed parallel to the articular surface and were bicortical.

Variability in physical therapy protocols following total shoulder arthroplasty

BACKGROUND

Physical therapy (PT) plays an important role in the recovery of function following anatomic total shoulder arthroplasty (aTSA). While several PT protocols have been published for these patients, there is no standardized protocol for aTSA rehabilitation. This lack of standardization may lead to confusion between patients and physicians, possibly resulting in suboptimal outcomes. This study examines how PT protocols provided by academic orthopedic surgery programs vary regarding therapeutic goals and activities following aTSA.

METHODS

PT protocols for aTSA available online from the Accreditation Council for Graduate Medical Education accredited orthopedic surgery programs were included for review. Each protocol was analyzed to evaluate it for differences in recommendation of length of immobilization, range of motion (ROM) goals, start time for and progression of therapeutic exercises, and timing for return to functional activity.

RESULTS

Of 175 accredited programs, 25 (14.2%) had protocols publicly available, programs (92%) recommended sling immobilization outside of therapy for an average of 4.4±2.0 weeks. Most protocols gave recommendations on starting active forward flexion (24 protocols, range 1-7 weeks), external rotation (22 protocols, range 1-7 weeks), and internal rotation (18 protocols, range 4-7 weeks). Full passive ROM was recommended at 10.8±5.7 weeks, and active ROM was 13.3±3.9 weeks, on average. ROM goals were inconsistent among protocols, with significant variations in recommended ROM and resistance exercise start times. Only 13 protocols (52%) gave recommendations on resuming recreational activities (mean, 17.4±4.4 weeks).

CONCLUSIONS

Publicly available PT protocols for aTSA rehabilitation are highly variable. Level of evidence: IV.

Increased Risk of Surgical Field Contamination from Acute Pre-operative Treatment of Pediculosis Capitis (Lice) Infestation - A Case Report of Two Twin Pediatric Patients

Introduction

Little is known about the perioperative management of Pediculus capitis (lice) infestations, including risk of contamination to the sterile field, whether to delay surgery, and optimal time to treat and/or operate.

Case Report

Two identical twin patients presented for elective in situ percutaneous pinning of chronic slipped capital femoral epiphyses. Active pediculosis capitis was noted intraoperatively by the anesthesia team during the first patient's surgery. Meticulous examination of the sterile field at that time demonstrated no organisms or other sources of contamination. The second patient's surgery was delayed to discuss her case with the infectious disease team. Scant literature exists to guide recommendations. Ultimately, a single permethrin treatment immediately before surgery was recommended and followed by our team. After careful prepping and draping, a louse was observed on the sterile field near the planned pin insertion site. The case was immediately canceled and delayed indefinitely. After two additional treatments over the next 4 days, only eggs (but no active insects) were observed in the patient's hair. We elected to proceed to surgery at that time, which concluded without issue.

Conclusion

The surgical implications of an active lice infestation are numerous. Administration of antiparasitic medication in the immediate pre-operative period causes increased movement in pediculosis capitis, which may increase risk of sterile field contamination. Elective procedures should be postponed to complete multiple rounds of permethrin. In cases of urgent/emergent surgery, or in which treatment delay is unfeasible, foregoing delousing treatment in the immediate pre-operative period may be recommended.

Factors and Radiographic Findings Influencing Patient-Reported Outcomes Following Maisonneuve Fractures

BACKGROUND

This research adds to the literature by providing prognostic information for physicians and patients regarding the outcomes of operative management of Maisonneuve fractures (MFs). To date, this is the only cohort study of patient-reported outcomes measurement information systems (PROMIS) scores following surgical fixation of MF. Patient outcomes were compared focusing on the mean population with an inter-analysis using basic demographic information, radiographic findings, and patient comorbidities and their respective impact on PROMIS scores.

METHODS

A total of 24 patients between 2012 and 2020 met the inclusion criteria and completed PROMIS surveys at a minimum of 18 months postoperatively. Patient charts were reviewed through the electronic medical record (EMR) for demographic information and comorbidities as well as operative variables. PROMIS scores for physical function (PF), pain interference (PI), and depression were obtained via follow-up visits and phone calls. The impact of categorical variables on complications was compared using Chi-Squared tests. Variables were analyzed with a type 3 SS test to stratify independent risk factors' effect on PROMIS scores and to account for confounding variables.

RESULTS

PROMIS PF averaged 44.84 and was significantly affected by BMI>30 (p=.033), hypertension (HTN) (p=.026), patients with clinical anxiety or depression (p=.047), and subsequent screw removal (p=.041). PROMIS PI averaged a score of 54.57 and was significantly affected by BMI>30 (p=.0046), coronary artery disease (CAD) (p=.0123), patients with clinical anxiety or depression (p=.0206), and subsequent screw removal (p=.0039). PROMIS depression scores averaged 46.03 and were significantly affected by the presence of CAD (p=.049) and subsequent screw removal (p=.023).

CONCLUSION

Patient-reported outcomes following MF surgery demonstrated PROMIS scores within +/- 1 standard deviation of the population-based control, and thus many patients can reasonably expect to return to a level of function comparable to the general population. Nonetheless, the significant effects of patient comorbidities and surgical variables ought to be evaluated and utilized as prognostic indicators when managing patient expectations prior to operative treatment of an MF injury.

The incidence of shoulder arthroplasty infection presents a substantial economic burden in the United States: a predictive model

Background

Periprosthetic joint infections (PJIs) are a major cause of morbidity after shoulder arthroplasty. Prior national database studies have estimated the trends of shoulder PJI up to 2012.²¹ Since 2012, the landscape of shoulder arthroplasty has changed drastically with the expanding popularity of reverse total shoulder arthroplasty. The dramatic growth in primary shoulder arthroplasties is likely paralleled with an increase of PJI case volume. The purpose of this study is to quantify the rise in shoulder PJIs and the economic stress they currently place on the American healthcare system as well as the toll they will incur over the coming decade.

Methods

The Nationwide Inpatient Sample database was queried for primary and revision anatomic total shoulder arthroplasty, reverse total shoulder arthroplasty, and hemiarthroplasty from 2011-2018. Multivariate regression was used to predict cases and charges through the year 2030 adjusted to 2021 purchasing power parity.

Results

From 2011 to 2018, PJI was found to be 1.1% shoulder arthroplasties, from 0.8% (2011) to 1.4% (2018). Anatomic total shoulder arthroplasty experienced the greatest proportion of infections at 2.0%, followed by hemiarthroplasty at 1.0% and reverse total shoulder arthroplasty at 0.3%. Total hospital charges grew 324%, from $44.8 million (2011) to $190.3 million (2018). Our regression model projects 176% growth in cases and 141% growth in annual charges by 2030.

Conclusion

This study demonstrates the large economic burden that shoulder PJIs pose on the American healthcare system, which is predicted to reach nearly $500 million in charges annually by 2030. Understanding trends in procedure volume and hospital charges will be critical in evaluating strategies to reduce shoulder PJIs.

Home-Based Physical Therapy Results in Similar Outcomes to Formal Outpatient Physical Therapy after Reverse Shoulder Arthroplasty: a Randomized Control Trial

INTRODUCTION

Outcomes following reverse total shoulder (RTSA) arthroplasty are influenced by surgical indications, surgical technique, implant design and patient variables. The role of self-directed postoperative physical therapy (PT) is poorly understood following RTSA. The purpose of this study was to compare the functional and patient reported outcomes (PRO) of a formal physical therapy program to a home therapy program after undergoing a reverse total shoulder arthroplasty.

METHODS

One hundred patients were prospectively randomized into two groups: formal PT (F-PT) and home-based PT (H-PT). Patient demographic variables along with range of motion (ROM), strength measurements and SST, ASES, SANE, VAS, PHQ-2 outcomes were collected preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Patient perceptions regarding their individual group, F-PT versus H-PT, were also assessed.

RESULTS

Sixty-eight patients were included for analysis with 37 in the H-PT group and 33 in the F-PT group. Thirty patients in both groups had a minimum of 6 months follow-up. Average follow-up was 20.8 months. Forward flexion, abduction, internal rotation and external rotation ROM did not differ between groups at final follow-up. Strength did not differ between groups with the exception of external rotation, which was greater with formal physical therapy by 0.8 kg/f (p=0.04). PRO at final follow-up did not differ between therapy groups. Patients receiving home-based therapy appreciated the convenience and cost-savings and the majority felt this was less burdensome.

CONCLUSION

Formal physical therapy and home-based physical therapy programs after reverse shoulder arthroplasty result in similar improvements in range of motion, strength, and PRO scores.

LEVEL OF EVIDENCE

Level I; Randomized Controlled Trial; Treatment Study.

Elective Hand Surgery Is Delayed among Private Insurance Holders

OBJECTIVES

Patients with private healthcare plans often defer nonemergent or elective procedures toward the end of the year once they have met their deductible. No previous studies have evaluated how insurance status and hospital setting may affect surgical timing for upper extremity procedures. Our study aimed to evaluate the influence of insurance and hospital setting on end-of-the-year surgical cases for elective carpometacarpal (CMC) arthroplasty, carpal tunnel, cubital tunnel, and trigger finger release, and nonelective distal radius fixation.

METHODS

Insurance provider and surgical dates were gathered from two institutions' electronic medical records (one university, one physician-owned hospital) for those undergoing CMC arthroplasty, carpal tunnel release, cubital tunnel release, trigger finger release, and distal radius fixation from January 2010 to December 2019. Dates were converted into corresponding fiscal quarters (Q1-Q4). Using the Poisson exact test, comparisons were made between the case volume rate of Q1-Q3 and Q4 for private insurance and then for public insurance.

RESULTS

Overall, case counts were greater in Q4 than the rest of the year at both institutions. There was a significantly greater proportion of privately insured patients undergoing hand and upper extremity surgery at the physician-owned hospital than the university center (physician owned: 69.7%, university: 50.3%; P < 0.001). Privately insured patients underwent CMC arthroplasty and carpal tunnel release at a significantly greater rate in Q4 compared with Q1-Q3 for both institutions. Publicly insured patients did not experience an increase in carpal tunnel releases during the same period at both institutions.

CONCLUSIONS

Privately insured patients underwent elective CMC arthroplasty and carpal tunnel release procedures in Q4 at a significantly greater rate than publicly insured patients. This finding suggests private insurance status, and potentially deductibles, influence surgical decision making and timing. Further work is needed to evaluate the impact of deductibles on surgical planning and the financial and medical impact of delaying elective surgeries.

The Relationship Between Posterior Tibial Slope and Pediatric Tibial Eminence Fractures

BACKGROUND

Tibial eminence fractures are bony avulsions of the anterior cruciate ligament from its insertion on the intercondylar eminence. Numerous anatomic factors have been associated with anterior cruciate ligament injuries, such as posterior tibial slope, but there are few studies evaluating the association with tibial eminence fracture.

PURPOSE

To compare posterior tibial slope of pediatric patients with and without tibial eminence fractures. We hypothesized that a steeper posterior tibial slope would be associated with tibial eminence fracture.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent surgical treatment of tibial eminence fracture were retrospectively identified between January 2000 and July 2021. Adults aged >20 years and those without adequate imaging were excluded. Controls without gross ligamentous or osseous pathology were identified. Descriptive information and Meyers and McKeever classification were recorded. Posterior tibial slope measurements were obtained by 2 independent orthopaedic surgeons twice, with measurements separated by 3 weeks. Chi-square tests and independent-samples t tests were used to compare posterior tibial slope and patient characteristics. Inter- and intrareviewer variability was determined via the intraclass correlation coefficient.

RESULTS

A total of 51 patients with tibial eminence fractures and 57 controls were included. By sex, tibial eminence fractures occurred among 34 male and 17 female patients with a mean age of 10.9 years. The posterior tibial slope among those with tibial eminence fractures (9.7°) was not significantly greater than that of controls (8.8°; P = .07). Male patients with a tibial eminence fracture had significantly steeper slopes compared with controls (10.0° vs 8.4°; P = .006); this difference was not observed between female patients and female controls. Patients with a slope ≥1 SD above the mean (12.0°) had 3.8 times greater odds (95% CI, 1.3-11.6; P = .017) of having a tibial eminence fracture. Male patients with a posterior tibial slope >12° had 5.8 times greater odds (95% CI, 1.1-29.1; P = .034) of having a tibial eminence fracture compared with male controls.

CONCLUSION

Male patients undergoing surgical fixation of a tibial eminence fracture had an increased posterior tibial slope as compared with case-controls. Increased posterior tibial slope may be a risk factor for sustaining a tibial eminence fracture, although the clinical significance of this deserves further investigation.

Allograft reconstruction for humeral head defects in the setting of shoulder instability: a systematic review

Background

Glenohumeral joint instability and dislocation are common orthopedic pathologies that can produce osseous humeral head defects such as Hill-Sachs (HS) or Reverse Hill-Sachs (RHS) lesions. Numerous reconstruction techniques have been reported in the literature, including remplissage, disimpaction, and allograft reconstruction. No group has previously assessed the outcomes of allograft reconstruction for RHS lesions, nor compared the outcomes of allograft reconstruction for HS and RHS lesions. In this study, we aim to provide a comprehensive assessment of osteochondral allograft reconstruction for the distinct pathologies of RHS lesions and HS lesions by comparing postreconstruction patient-reported outcomes, complications, and radiographic assessments for each lesion.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review was performed to identify and include studies that reported patient outcomes after the use of osteochondral allografts in the reconstruction of HS or RHS lesions of the humeral head. A comprehensive search of the Google Scholar, PubMed, and Embase databases was conducted with the key terms "allograft," "Hill-Sachs," and "reverse Hill-Sachs."

Results

Eight studies, with a total of 84 patients, were included for review. Of the 84 allograft-treated patients, there were 44 patients with HS lesions and 40 patients with RHS lesions. The average patient age was 27.3 years for HS lesions and 43.0 years for RHS lesions. Postoperative range of motion and average Constant-Murley score (87.9 for HS and 80.1 for RHS) appeared to be greater for those with HS lesions. In addition, 20.5% of HS patients experienced postoperative complications, whereas 42.5% of RHS patients had postoperative complications (P = .03). HS and RHS patients experienced similar proportions of graft resorption or collapse rate (22.7% for HS and 12.5% for RHS; P = .2).

Conclusion

Patient-reported outcomes indicate that osteochondral allograft reconstruction for large RHS and HS lesions is an acceptable intervention. RHS patients had lower rates of graft resorption and collapse but worse postoperative range of motion and functional outcomes, although these differences were not statistically significant. HS patients experienced significantly fewer complications than those with RHS lesions.

A Complicated Case of Postpartum Myasthenic Crisis

Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction (NMJ) of voluntary skeletal muscle. This disease is characterized by ptosis, diplopia, facial muscle weakness, bulbar muscle involvement including dysphagia and difficulty chewing, dysarthria, hypophonia, respiratory muscle fatigue, and sometimes generalized weakness. A myasthenic crisis (MC) is a complication of MG. MC is defined as severe worsening of respiratory function necessitating the need for mechanical ventilation. Precipitating factors include infection, certain drugs, pregnancy, childbirth, surgery, discontinuation of medical therapy, or even spontaneously with no inciting event. Here we present a complicated case of a 24-year-old patient with a long history of controlled who encounters many events that lead to an MC necessitating mechanical intubation, plasmapheresis, and high dose immunosuppressive therapy. She recently gave birth to a child, had an occult perforated appendicitis with multiple abscesses needing emergent exploratory laparotomy, and had an overlying COVID-19 infection. The complexity of this disease and its complications warrants careful consideration by physicians in any branch of specialty.

Massive hemoperitoneum without peritoneal signs: An unusual presentation of omental ectopic rupture. A case report

Background

Extrauterine ectopic pregnancy is a rare form of ectopic pregnancy, accounting for roughly 1:10,000–30,000 of all pregnancies. Primary omental pregnancy is the least common form of abdominal ectopic pregnancies, making it extremely rare. Typical presentation includes pelvic pain, secondary amenorrhea, with or without vaginal bleeding. Atypical presentations range from nonspecific pain to asymptomatic.

Case

A 19-year-old woman presented to the emergency department after several syncopal episodes. She had a positive urine pregnancy test (serum hCG 446 IU/L). Her hemoglobin level was 10.6 g/dL. Due to lack of pain or bleeding, abdominal imaging was not indicated. A head CT scan rendered negative results. She was subsequently diagnosed with idiopathic headaches and anemia and was discharged. She returned to hospital 48 h later with vaginal bleeding and additional syncopal episodes. She was not experiencing any abdominal pain or discomfort. Her anemia worsened (hemoglobin 7.5 g/dL). For this reason, imaging was performed. It was significant for massive hemoperitoneum. Due to the imaging findings and worsening anemia, diagnostic exploratory laparoscopy was recommended to evaluate for ruptured ectopic pregnancy. Laparoscopic findings revealed large hemoperitoneum and a 10-week gestational sac attached to the greater omentum near the transverse colon. This exceedingly rare presentation of extrauterine ectopic pregnancy offered few clinical clues other than worsening anemia until imaging later revealed the abnormality. Ruptured ectopic pregnancy, a potentially fatal complication of pregnancy, should be included into the differential diagnosis of any gravid patient with syncope and anemia unexplained by extensive diagnostic workup.

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Primary omental ectopic pregnancy is exceedingly rare.

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Ectopic pregnancy with massive hemoperitoneum can present as painless, occult bleeding.

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Hemodynamic instability is often overlooked in early pregnancy due to expectation of low blood pressure.

Penetrating Thoracoabdominal Trauma With a Cryptic Diaphragmatic Injury in a 23-Year-Old Male

Traumatic diaphragmatic injuries are a rare entity and can occur in relation to penetrating thoracic and abdominal trauma. The most common clinical features of diaphragm rupture include chest or abdominal bruising, decreased breath sounds, and signs of bowel obstruction. However, the classic signs and symptoms of diaphragmatic injury are not always present and can be obscured even in the highest resolution imaging. This highlights the importance for maintaining a high index of suspicion to make the diagnosis and properly manage these patients. Here, we present a rare case of a 23-year-old male who experienced a laceration to his left thorax and was later discovered to have concurrent diaphragmatic injury despite an initially noncontributory physical exam and imaging findings. The patient subsequently underwent robotic repair of the injury and reduction of herniated contents.

Jaw Pain and Profound Bradycardia – An Atypical Presentation of Lyme Carditis

In 2018, 23,558 confirmed cases and 10,108 probable cases of Lyme disease were reported in the United States, with 96% of all cases coming from 14 states. Lyme carditis is well described, occurring in less than 1% of Lyme disease. High-grade heart block is uncommon in early disseminated Lyme disease. In Lyme carditis due to sinus node dysfunction and/or high grade atrioventricular block, the pulse rates are significantly lower which can lead to syncope. This can happen in the setting of an unstable ventricular escape rhythm with pulse rates ranging around 30 beats per minute or lower. In patients with low cardiovascular reserve, high-degree AV block can cause sudden death. Here we describe a rare case of profound bradycardia in disseminated Lyme disease. The patient’s only two symptoms are bradycardia and jaw pain. He lacks erythema migrans, neurological symptoms or syncope - despite having high-degree AV block. Initially prescribed doxycycline 100mg BID, his PR interval begins to normalize, but once a Lyme titre was positive for IgM (p41, p39, p23) and IgG (p66, p45, p41, p39, p23, p18), the patient was switched to 2g ceftriaxone IV Q 24h, per Infectious Disease Society of America (IDSA) guidelines. After several days he feels better and was discharged home to complete antibiotics and wear a cardiac event monitor. Lyme disease has three distinct stages that include early localized infection, early disseminated disease, and late infection. At the time of Lyme carditis diagnosis, common symptoms include erythema migrans, malaise, polyarthritis, Bell’s palsy and other neurological symptoms - all of which were lacking in our patient. The prognosis for Lyme carditis is generally good, despite disagreement over the incidence of persistent B. burgdorferi infection. This patient’s unique presentation of Lyme carditis is further evidence of variability in cardiac symptoms depending on one’s immunological and physiological ability to combat acute spirochete infection.

Ventricular and Periventricular Anomalies in the Aging and Cognitively Impaired Brain

Ventriculomegaly (expansion of the brain’s fluid-filled ventricles), a condition commonly found in the aging brain, results in areas of gliosis where the ependymal cells are replaced with dense astrocytic patches. Loss of ependymal cells would compromise trans-ependymal bulk flow mechanisms required for clearance of proteins and metabolites from the brain parenchyma. However, little is known about the interplay between age-related ventricle expansion, the decline in ependymal integrity, altered periventricular fluid homeostasis, abnormal protein accumulation and cognitive impairment. In collaboration with the Baltimore Longitudinal Study of Aging (BLSA) and Alzheimer’s Disease Neuroimaging Initiative (ADNI), we analyzed longitudinal structural magnetic resonance imaging (MRI) and subject-matched fluid-attenuated inversion recovery (FLAIR) MRI and periventricular biospecimens to map spatiotemporally the progression of ventricle expansion and associated periventricular edema and loss of transependymal exchange functions in healthy aging individuals and those with varying degrees of cognitive impairment. We found that the trajectory of ventricle expansion and periventricular edema progression correlated with degree of cognitive impairment in both speed and severity, and confirmed that areas of expansion showed ventricle surface gliosis accompanied by edema and periventricular accumulation of protein aggregates, suggesting impaired clearance mechanisms in these regions. These findings reveal pathophysiological outcomes associated with normal brain aging and cognitive impairment, and indicate that a multifactorial analysis is best suited to predict and monitor cognitive decline.

Novel Microscalpels for Removing Proximal Composite Resin Overhangs on Class II Restorations

Introduction:

Limited access to interdental spaces complicates removal of excess material when placing class II composite resin restorations. Evidence-based recommendations on interproximal finishing are rare. We present novel microscalpels for this indication. The aim of the study was to test their fracture strength and cutting ability and to compare microscalpels with the use of a scaler, oscillating devices (G5-ProShape, G5-Proxocare), finishing strips and scalpels of sizes 12, 15, and 21 in a standardized in vitro model.

Methods and Materials:

Fracture strength (LOAD) and cutting forces (CUT) of microscalpels were evaluated at different angles (15, 30, 60, and 75 degrees; n=30 each) in a universal testing machine. Devices were compared in vitro using standardized composite overhangs. Marginal quality (QUAL; n=30) and quantity of excess/deficit (QUAN; n=30) were evaluated using scanning electron microscopy (SEM) for each device (explorative data analysis, Student t-test or analysis of variance; post hoc Scheffé).

Results:

Microscalpels showed the highest LOAD (95.8 [5.0] N) (mean [standard deviation]) and easiest cutting (CUT) (7.6 [1.5]) at 15 degrees. At all angles, LOAD was significantly higher than CUT (p&lt;0.001). Perfect margins were seen most often with scalpel size 12 (QUAL: 37% relative frequency), while most excess (73.4%) was observed with finishing strips. QUAN was lowest with microscalpels (19.3 [4.4] μm) and highest with finishing strips (116.0 [18.8]). Use of scalers led to fractures and crack formation.

Conclusion:

Microscalpels are able to cut composite at a lower force than necessary to fracture the blades at all angles. Small and/or curved scalpels yield the best-quality margins.

Taxonomy of the super-cryptic Hyperolius nasutus group of long reed frogs of Africa (Anura: Hyperoliidae), with descriptions of six new species

Specimens from across the range of the Hyperolius nasutus species group were sequenced for two mitochondrial genes and one nuclear gene. Advertisement calls were recorded from the same specimens where possible, and morphological characters were compared. Bayesian inference and maximum likelihood produced a tree indicating 16 clades. The clades show little or no overlap in combinations of 16S sequence difference, shared tyr haplotypes, advertisement call parameters, snout profiles and webbing. On the basis of these data we recognise H. acuticeps, H. adspersus, H. benguellensis, H. dartevellei, H. igbettensis, H. nasutus, H. nasicus, H. poweri, H. viridis and describe six new species: Hyperolius friedemanni sp. nov. Mercurio & Rödel, Hyperolius howelli sp. nov. Du Preez & Channing, Hyperolius inyangae sp. nov. Channing, Hyperolious jacobseni sp. nov. Channing, Hyperolius rwandae sp. nov. Dehling, Sinsch, R6del & Channing, and Hyperolius lupiroensis sp. nov. Channing. Hyperolius lamottei is confirmed to be outside the H. nasutus group clade. Hyperolius granulatus, H. oxyrhynchus, H. punctulatus and H. sagitta are assigned as junior synonyms. As our results are based on a small number of specimens, these hypotheses await testing with larger sample sizes and more characters. A species distribution model suggests where outlier populations might be found.

Muscle pathologies after cervical spine distortion-like exposure--a porcine model

OBJECTIVE

Histological evaluation of porcine posterior cervical muscles after a forceful translational and extensional head retraction simulating high-speed rear end impact.

METHODS

Four anesthetized pigs were exposed to a cervical spine distortion (CSD)-like motion in a lying position. After 2 different survival times of 4 and 6 h (posttrauma), the pigs were euthanized and tissue sampling of posterior cervical muscles was performed. A standard histological staining method involving paraffin-embedded sections was used to analyze the muscles, focusing on injury signs like hemorrhage and inflammatory cell reaction. A pig that was not subjected to impact was used as a control pig and was subjected to the same procedure to exclude any potential artifacts from the autopsy.

RESULTS

The differentiation of 8 different posterior neck muscles in the dissection process was successful in more than 50 percent for each muscle of interest. Staining and valid analysis was possible from all extracted samples. Muscle injuries to the deepest posterior neck muscles could be found, especially in the musculus obliquus samples, which showed laminar bleedings in 4 out of 4 samples. In addition, in 4 out of 4 samples we were able to see increased cellular reactions. The splenius muscle also showed bleeding in all 4 samples. All animals showed muscle injury signs in more than three quarters of analyzed neck muscles. Differences between survival times of 4 and 6 h in terms of muscular injury were not of primary interest and could not be found.

CONCLUSIONS

By simulating a CSD-like motion we were able to confirm injuries in the posterior cervical muscles under severe loading conditions. Further studies need to be conducted to determine whether these muscle injuries also occur under lower exposure forces.

Pilot study of compliance with healthcare facility smoking laws in Georgia

In 2003 Georgian Parliament restricted smoking in all healthcare facilities to designated smoking areas. Observed compliance has been low. This quantitative study of airborne nicotine and particulate concentrations in nine healthcare facilities in Tbilisi and Region Kakheti in February, 2007 was a pilot to assess the degree of noncompliance with the law and to identify potential strategies for increasing compliance. Passive sampling of nicotine and active sampling of PM(2.5) in selected healthcare facilities. None of the facilities we monitored had designated smoking areas that met the legal requirements. Fifty of the 51 samplers registered concentrations of nicotine above the level of detection. Of these, 52% showed concentrations below 1 microg/m(3) nicotine, 27% showed concentrations between 1 and 5 microg/m(3) and 20% were above 5 microg/m(3). The highest nicotine levels were found in medical staff offices, and in undesignated "informal smoking areas". These data support qualitative observations that the law restricting smoking in Georgian healthcare facilities to designated areas is poorly enforced and does not protect patients and employees from secondhand smoke. These findings suggest that Georgian law should be changed to make all healthcare institutions smoke free environments and that there is a need for tobacco control programs targeted at medical professionals in Georgia.

Philip Morris toxicological experiments with fresh sidestream smoke: more toxic than mainstream smoke

BACKGROUND

Exposure to secondhand smoke causes lung cancer; however, there are little data in the open literature on the in vivo toxicology of fresh sidestream cigarette smoke to guide the debate about smoke-free workplaces and public places.

OBJECTIVE

To investigate the unpublished in vivo research on sidestream cigarette smoke done by Philip Morris Tobacco Company during the 1980s at its Institut für Biologische Forschung (INBIFO).

METHODS

Analysis of internal tobacco industry documents now available at the University of California San Francisco Legacy Tobacco Documents Library and other websites.

RESULTS

Inhaled fresh sidestream cigarette smoke is approximately four times more toxic per gram total particulate matter (TPM) than mainstream cigarette smoke. Sidestream condensate is approximately three times more toxic per gram and two to six times more tumourigenic per gram than mainstream condensate by dermal application. The gas/vapour phase of sidestream smoke is responsible for most of the sensory irritation and respiratory tract epithelium damage. Fresh sidestream smoke inhibits normal weight gain in developing animals. In a 21 day exposure, fresh sidestream smoke can cause damage to the respiratory epithelium at concentrations of 2 microg/l TPM. Damage to the respiratory epithelium increases with longer exposures. The toxicity of whole sidestream smoke is higher than the sum of the toxicities of its major constituents.

CONCLUSION

Fresh sidestream smoke at concentrations commonly encountered indoors is well above a 2 microg/m3 reference concentration (the level at which acute effects are unlikely to occur), calculated from the results of the INBIFO studies, that defines acute toxicity to humans. Smoke-free public places and workplaces are the only practical way to protect the public health from the toxins in sidestream smoke.

DBH*444G/A polymorphism of the dopamine-β-hydroxylase gene is associated with alcoholism but not with severe alcohol withdrawal symptoms

As the enzyme dopamine-beta-hydroxylase (DbetaH) converts dopamine to norepinephrine and both transmitters seem to be involved in the pathology of alcoholism and severe alcohol withdrawal symptoms, the gene encoding DbetaH (DBH) was applied to explore the genetic background of alcoholism and severe withdrawal symptoms. 102 healthy control subjects and 208 alcoholics, including 97 patients with a history of mild withdrawal symptoms, 57 with a history of alcohol withdrawal seizure (AWS) and 82 with a history of delirium tremens (DT) were genotyped for the DBH*444G/A polymorphism revealing a significantly elevated frequency of genotypes carrying the A-allele (p = 0.02; after Bonferroni adjustment for multiple tests) in alcoholics compared to healthy controls. Frequencies of alleles and genotypes of individuals with mild withdrawal symptoms did not differ significantly from those of patients with DT or AWS.

Severity of alcohol withdrawal symptoms and the T1128C polymorphism of the neuropeptide Y gene

Neuropeptide Y (NPY) modulates ethanol drinking in rodents. The C-allele of the T1128C polymorphism of the human NPY gene has been previously associated with elevated alcohol consumption in a Finn population study. The present study tested the hypothesis that the T1128C polymorphism is associated with the diagnosis of alcoholism or with severe forms of alcohol withdrawal and with the daily consumption of alcohol in alcoholic patients. After PCR-RFLP genotyping, two groups of alcoholics with severe withdrawal symptoms (delirium tremens, n = 83; withdrawal seizures, n = 65) were compared to alcoholics with mild withdrawal symptoms (n = 97). An elevated frequency of the C-allele in the individuals with severe withdrawal symptoms was found, however not reaching statistical significance. Further a group of healthy controls (n = 102) was compared to all included alcoholics (n = 216) revealing no significant result. Alcoholics carrying the C-allele reported a non significantly elevated daily consumption of alcohol compared to alcoholics with the TT genotype. All alcohol dependent subjects with severe withdrawal symptoms revealed a significantly elevated daily consumption of alcohol compared to alcoholics with only mild withdrawal symptoms. More studies on different ethnic groups are needed to further elucidate the influence of the NPY gene on alcoholism.

Muir-Torre syndrome: a case for surveillance of the ampulla of Vater

A 64-year-old man with Muir-Torre syndrome (MTS), a condition characterized by the association of multiple sebaceous tumours and kerato-acanthomas with internal malignancies, developed a carcinoma of the ampulla of Vater. This is the 2nd reported ampullary carcinoma in 205 reported cases of MTS, suggesting a higher prevalence in MTS patients than in the general population. As an ampullary carcinoma is potentially amenable to surgical resection, particularly when detected early, patients with MTS should undergo regular endoscopic surveillance of the ampulla of Vater.

Cortical responses to object-motion and visually-induced self-motion perception

We investigated the spatiotemporal cortical dynamics during the perception of object-motion and visually-induced self-motion perception in six normal subjects, using a 143-channel neuromagnetometer. Object-motion specific tasks evoked early transient activity over the right temporooccipital cortex, while self-motion perception, or vection, additionally was followed by sustained bilateral activity in the temporoparietal area. The specific signal distributions suggest to represent the different perceptual modes of object-motion and self-motion sensation.

Lingual vascular canals of the mandible: evaluation with dental CT

PURPOSE

To evaluate whether dental computed tomography (CT) can depict the frequency, diameter, position, and direction of vessels entering the mandible through lingual bone canals.

MATERIALS AND METHODS

Thirty-two consecutive patients underwent preimplantation CT of the lower jaw and examination for the presence, number, location, diameter, and direction of lingual canals entering the mandible. In addition, three cadaver mandibles were investigated with dental CT and subsequently dissected to confirm the CT findings.

RESULTS

All patients demonstrated at least one lingual vascular canal, and 20 (63%) had multiple (two to five) canals. The typical lingual canal locations were the midline of the mandible and the premolar region. The mean diameter of the lingual canals was 0.7 mm +/- 0.3 (SD) (range, 0.4--1.5 mm) in the midline and 0.6 mm +/- 0.2 (range, 0.3--1.2 mm) in both premolar regions of the mandible. Examination results in the three cadaver mandibles confirmed the CT findings in those mandibles.

CONCLUSION

Dental CT can depict the occurrence, position, and size of the lingual vascular canals of the mandible. Radiologists should be aware of this anatomic feature and its possible implications.

Preoperative fast MRI of brain tumors using three-dimensional segmented echo planar imaging compared to three-dimensional gradient echo technique

The purpose of this study was to compare the diagnostic efficacy of a newly developed T(1)-weighted three-dimensional segmented echo planar imaging (3D EPI) sequence versus a conventional T(1)-weighted three dimensional spoiled gradient echo (3D GRE) sequence in the evaluation of brain tumors. Forty-four patients with cerebral tumors and infections were examined on a 1.0 T MR unit with 23 mT/m gradient strength. The total scan time for the T(1) 3D EPI sequence was 2 min 12 s, and for a conventional 3D GRE sequence it was 4 min 59 s. Both sequences were performed after administration of a contrast agent. The images were analyzed by three radiologists. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, signal-to-noise and contrast-to-noise-ratio (C/N) were calculated. The gray-white differentiation and C/N ratio of 3D EPI were found to be inferior to conventional 3D GRE images, but the difference was not statistically significant. In the qualitative comparison, lesion detection and conspicuity of 3D EPI images and conventional 3D GRE images were similar, but a tow-fold reduction of the scanning time was obtained. With the 3D EPI technique, a 50% scan time reduction could be achieved with acceptable image quality compared to conventional 3D GRE. Thus, the 3D EPI technique could replace conventional 3D GRE in the preoperative imaging of brain.

Detection of focal hepatic lesions: comparison of unenhanced and SHU 555 A-enhanced MR imaging versus biphasic helical CTAP

The purpose of this study was to compare the diagnostic sensitivity of unenhanced magnetic resonance (MR) imaging, and MR imaging with a new superparamagnetic iron oxide (SPIO)-enhanced contrast agent (SHU 555 A) with biphasic helical computed tomography during arterial portography (CTAP) in patients with focal liver lesions. Eighteen patients with a total of 91 (78 malignant, 13 benign) proven liver lesions underwent unenhanced short tau inversion recovery (STIR), T2-weighted (T2-w) TSE, and SHU 555 A-enhanced T2-w turbo spin-echo (TSE) MR imaging and biphasic helical CTAP. The standard of reference was histopathologic analysis of resected specimens in 59 lesions, intraoperative ultrasound with biopsy in 20 lesions, and CT-guided biopsy and follow-up in 12 lesions. Diagnostic performance of the imaging modalities was compared quantitatively and qualitatively by assessing lesion involvement in liver segments. There were 68 lesions detected on unenhanced T2-w TSE, which resulted in a sensitivity of 75%. With the STIR sequence, 76 lesions were detected, for a sensitivity of 84%, and with SHU 555 A-enhanced MRI, 84 lesions were detected, for a sensitivity of 92%. CTAP detected 88 lesions, for a sensitivity of 97%. The accuracy for unenhanced T2-w TSE was 98%, for STIR 99%, for enhanced-MRI 100%, and for CTAP 95%. The specificity was 100% for SHU 555 A-enhanced MRI and 95% for CTAP. SHU 555 A-enhanced MRI was superior to nonenhanced MRI (P < 0.05) and equivalent to CTAP in terms of sensitivity. Due to the absence of false-positive results on SHU 555 A-enhanced MRI, the specificity and accuracy of enhanced MRI were higher than those of CTAP, but the difference was not statistically significant (P = 0.134).

Ultrafast magnetic resonance imaging of the brain

The purpose of this study was to compare the diagnostic efficacy of single shot fast spin echo sequence (SSh-FSE), and single shot GRASE-sequence (SSh-GRASE) to the conventional T(2)-weighted fast spin echo-sequence (T(2)-FSE) in the imaging of brain disorders. Thirty three patients with high signal intensity lesions on T(2)-weighted images (n = 28), or intracerebral hemorrhage (n = 5), were examined on a 1.0 T MR scanner, with 23 mT/m gradient strength. The scan time for the conventional T(2)-FSE-sequence was 2 min 57 s, the scan time for the single shot-FSE-, and single shot-GRASE-sequences was 11 sec, and 17 sec, respectively. Twenty-one patients remained still during the examination, whereas 12 could not stay still with consecutive marked motion artifacts. Images were reviewed by three radiologists. Lesion conspicuity, image quality, and artifacts were scored on a subjective scale. Signal-to-noise ratios of lesions and normal tissue and contrast-to-noise ratios (CNR) were measured by region of interest (ROI). In the patient group without motion artifacts conspicuity for lesions > or =5 mm did not show a significant difference on conventional T(2)-FSE, single shot-FSE and single shot-GRASE. Detectability of the smaller lesions was significantly inferior on single shot-FSE-, and single shot-GRASE-sequences in artifact free images. For the patient group with motion artifacts SSh-FSE and SSh-GRASE were markedly superior to the conventional T(2)-FSE. Grey-white differentiation was better on conventional T(2)-FSE. Physiologic ferritin as well as pathologic hemosiderin depositions were slightly darker and therefore better visible on SSh-GRASE than on SSh-FSE. Conventional T(2)-FSE showed significantly more artifacts. In conclusion, SSh-FSE and SSh-GRASE imaging can be used for rapid imaging of the brain in those patients who are claustrophobic or in patients with involuntary movements due to extrapyramidal disorders, as well as in children in whom anesthesia is contraindicated or sedation is not possible.

Atypical appearance of elastofibroma dorsi on MRI: case reports and review of the literature

Three patients with histologically proven elastofibroma dorsi underwent MRI, using T1-weighted, T2-weighted, STIR (short inversion time inversion recovery), and contrast-enhanced SE sequences. All lesions typically displayed low signal intensity masses interspersed with areas of high signal intensity on T1- and T2-weighted SE images. Contrary to prior reports, two patients showed marked enhancement of the mass after administration of Gd-DTPA. Although the characteristic signal intensity on conventional T1- and T2-weighted images may lead to the early diagnosis of this rare tumor, radiologists should be aware that marked contrast enhancement may be representative in elastofibroma dorsi.

[Magnetic resonance tomography in dental radiology (dental MRI)]

PURPOSE

To demonstrate the usefulness of Dental-MRT for imaging of anatomic and pathologic conditions of the mandible and maxilla.

METHODS

Seven healthy volunteers, 5 patients with pulpitis, 9 patients with dentigerous cysts, 5 patients after tooth transplantation and 12 patients with atrophic mandibles were evaluated. Studies of the jaws using axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been to performed. The acquired images were reconstructed with a standard dental software package on a workstation as panoramic and cross sectional views of the mandible or maxilla.

RESULTS

The entire maxilla and mandibula, teeth, dental pulp and the content of the mandibular canal were well depicted. Patients with inflammatory disease of the pulp chamber demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media application marked enhancement of the dental pulp can be found.

CONCLUSION

Dental-MRT provides a valuable tool for visualization and detection of dental diseases.

Elastofibroma dorsi. Study of two cases and magnetic resonance imaging findings

Two cases of elastofibroma dorsi (one bilateral, one unilateral) in the periscapular and infrascapular region of two male patients are described. Magnetic resonance imaging revealed a tumorous mass of typical low signal intensity with interspersed areas of high signal intensity on T1 and T2 weighted spin echo sequences. In contrast to previous studies that reported mild enhancement within elastofibromas after administration of intravenous contrast agent, marked enhancement in one of two elastofibromas was found. This is considered to be atypical for benign lesions. After biopsy and histopathologic examination, an intended marginal resection was performed in both cases. Laboratory values, radiographs, and computed tomography may not be helpful in differentiating elastofibroma from malignant tumors. In addition to careful clinical investigation, magnetic resonance imaging is the method of choice leading to a presumptive diagnosis. Because marked enhancement on contrast agent images was observed, which is characteristic for malignant tumors, one should be aware that this feature does not exclude the presence of elastofibroma. Accurate diagnosis should be made preferably by biopsy and histopathologic evaluation before additional treatment is administered. Marginal resection is curative in patients with symptoms. Despite its low incidence, this pseudotumoral lesion should be known generally to differentiate it from malignant tumors and to avoid unnecessary wide or radical surgery.

Virchow-Robin spaces in childhood migraine

Virchow-Robin spaces (VRS) are pia-lined extensions of the subarachnoid space which surround penetrating arteries as they enter the brain on its surface. Using high-resolution MRI, which shows small penetrating arteries, we studied a possible association of accentuated VRS in children with tension-type headache (TTH) or migraine. We studied 58 children aged 3-14 years (mean 10.8 years) with a clinical diagnosis of migraine (31) or TTH (27), who underwent cerebral MRI, and 30 headache-free patients of the same age (mean 10.2 years) and 30 adult migraineurs with postpubertal onset of symptoms, who served as controls. The images were reviewed for structural abnormalities in the regions of the small penetrating arteries. Accentuated VRS were found in 61% of the children with migrainous headaches and in 22% of children of those with TTH. Prominent VRS were seen in 27% of the control children and in only 13% of the adults. Small infarcts and gliosis were rare in children with or without headache, but were seen in 30% of the adult migraineurs. Our findings show that accentuated VRS are significantly more common in children with migraine than in those with TTH or headache-free controls. Detection of accentuated VRS may therefore enhance differential diagnosis of primary headaches in children, contributing to an improvement in management.

Dry versus conventional laser imagers: film properties and image quality

The authors compared image quality and stability with a dry laser imager versus a conventional wet laser imager. Hard copies of 56 magnetic resonance imaging and computed tomographic studies were analyzed for gray-scale distribution and temperature stability. Results with the dry laser imager did not reach the quality of results with a wet laser imager, but the performance and ecologic criteria were sufficient to make use of this technique advantageous.

[Occult fractures of the wrist joint: high resolution image magnification roentgen versus MRI]

PURPOSE

To compare the diagnostic value of high definition macroradiography and MRI in patients with the suspicion of occult wrist fractures.

MATERIALS AND METHODS

In a prospective study, 23 patients with clinically suspected wrist fractures and normal initial plain radiographs underwent high resolution macroradiography and MR imaging shortly after trauma. Macroradiographs were taken with a microfocus tube using an anode of 0.03-0.3 mm providing a 4x magnification of the wrist, which was obtained in 4 projections. MR images were performed on a 1.0 T MR unit in coronal planes using T1 weighted SE, T2.-weighted 3D GE, and Turbo-STIR sequences. Follow-up radiographs after 6 weeks were used to confirm the diagnosis of a primary occult wrist fracture.

RESULTS

Macroradiography depicted 5 wrist fractures: 4 fractures of the scaphoid bone and 1 fracture of the capitate bone. MRI demonstrated 11 fractures (one of them false-positive): 9 fractures of the scaphoid bone and two fractures of the capitate bone. Using macroradiography, the sensitivity for the detection of occult fractures of the wrist was 50% with a specificity of 100%, using MRI the sensitivity was 100% with a specificity of 92%.

CONCLUSION

MRI seems to be superior to high resolution macroradiography in the detection of occult scaphoid fractures and thus is recommended in the management of patients with clinically suspected scaphoid fractures not evident on initial plain films.

[MRI arthrography of the ankle joint]

Due to its superior soft tissue contrast conventional MRI is the imaging method of choice in the evaluation of ankle joint disorders. Conventional MR imaging can accurately demonstrate normal or acutely injured ligaments; however, in subacute and chronic injury joint fluid necessary for delineation of injured ligaments is absent and MR arthrography should be performed. MR arthrography uses the intraarticular injection of contrast material to distend the joint, yielding improved discrimination of intraarticular structures. This joint distension with MR arthrography is also helpful in the staging of osteochondritis dissecans, since in cases of unstable lesions tracking of contrast material into the interface can be more easily demonstrated. Finally, high contrast and joint distension by MR arthrography improves the detection of intraarticular loose bodies, which often require surgery. MR arthrography, although invasive, may provide additional information in various ankle joint disorders.

Differentiation of benign and malignant tumors of the parotid gland: value of pulsed Doppler and color Doppler sonography

To establish criteria for the differentiation of benign and malignant tumors of the parotid gland using color Doppler sonography (CDS) and pulsed Doppler sonography (PDS) we examined 37 patients with parotid tumors by gray-scale ultrasound, CDS, and PDS. Tumor vascularization displayed by CDS was graded subjectively on a 4-point scale (0 = no vascularization, 3 = high vascularization). From the Doppler spectrum, the highest systolic peak flow velocity, the resistive index (RI), and the pulsatility index (PI) were calculated. There were 11 malignant and 26 benign tumors. Tumor vascularization by CDS was grade 0 or 1 in 88.5% of benign lesions, whereas it was grade 2 or 3 in 82% of malignant lesions (P < 0.0001). The highest systolic peak flow velocity was statistically significantly higher in malignant lesions than in benign lesions. Using a threshold systolic peak flow velocity of 25 cm/s, sensitivity was 72% and specificity was 88% for the detection of a malignant tumor. Evaluation of tumor vascularization by CDS and PDS cannot differentiate between benign and malignant parotid tumors with certainty. However, high vascularization and high systolic peak flow velocity in tumor vessels should raise the suspicion of malignancy, even if tumor morphology on gray-scale sonography indicates a benign lesion.

[Dental magnetic resonance tomography (dental MRI) as a method for imaging maxillo-mandibular tooth retention structures]

PURPOSE

To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla.

METHODS

Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a work-station as panorama and cross-sectional views of the mandible or maxilla.

RESULTS

The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated.

CONCLUSION

Dental-MRT promises to provide a new tool for visualization and detection of dental diseases.

Coaxial technique: approach to breast core biopsies

PURPOSE

To assess the feasibility of the coaxial core breast biopsy technique performed under stereotactic and ultrasound (US) guidance in vitro and in vivo.

MATERIALS AND METHODS

Biopsies were performed in vitro and in vivo with a coaxial technique. In vitro, the true needle-tip deviation was measured with a breast phantom on a stereotactic device with alteration of x and y axes. In vitro US studies were performed to evaluate the optimal technique for harvesting sufficient material for histologic work-up. In 205 patients, coaxial biopsy was performed in 210 suspicious lesions under US (61 lesions) or stereotactic (patient in the sitting position, n = 67; patient in the prone position, n = 82) guidance. In addition, the coaxial system was used for preoperative localization. Surgery and histologic work-up were performed in all cases.

RESULTS

In vitro, the true needle-tip deviation was found to be less than indicated on the stereotactic device. A factor was introduced to correct this error. For US guidance, angulation or rotation of the coaxial needle within the lesion proved to be the best technique to increase the size of histologic specimen. Of the 210 lesions, 112 were benign and 98 were malignant. Agreement between biopsy results and final postsurgical histologic analysis was found in 205 cases (98%).

CONCLUSION

The coaxial breast biopsy technique is an accurate, simple, and time-saving method performed under stereotactic or US guidance.