Factors contributing to glenoid baseplate micromotion in reverse shoulder arthroplasty: a biomechanical study.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is typically performed in patients with cuff tear arthropathy. A common type of RSA baseplate has a central peg and 4 peripheral screws inserting into the glenoid surface. Baseplate failure is a significant postoperative complication that reduces prosthetic longevity and usually requires revision surgery. This study evaluated the contribution of mechanical factors on initial baseplate fixation. MATERIALS AND METHODS: This study simulated glenoid baseplate loading in a RSA. A half-fractional factorial design was used to test 5 factors: bone density (160 or 400 kg/m3), screw length (18 or 36 mm), number of screws (2 or 4), screw angle (neutral or diverging), and central peg length (13.5 or 23.5 mm). Trials were cyclically loaded at a 60° angle with 500 N for 1000 cycles. Micromotion at 4 peripheral screw positions was analyzed using a multifactorial analysis of variance (P < .05). RESULTS: We found an increase in micromotion with 3 scenarios: (1) lower bone density at all screw positions; (2) shorter central peg length at the inferior, superior and anterior screws; and (3) shorter screw length at the inferior and anterior screws. There were interactions between bone density and screw length at the inferior and anterior screws and between bone density and central peg length at the inferior, superior, and anterior screws. DISCUSSION: Greater bone density, a longer central peg, and longer screws provide improved initial glenoid fixation in an RSA, whereas the number of screws, and the angle of screw insertion do not. These findings may help minimize baseplate failure and revision operations.

Cardiovascular Comorbidities Do Not Impact Prostate Artery Embolisation (PAE) Outcomes: Retrospective Analysis of the National UK-ROPE Registry.

PURPOSE: Prostate artery embolisation (PAE) is a key treatment for the management of symptomatic benign prostatic hyperplasia (BPH). Common cardiovascular risk factors might be associated with suboptimal outcomes and thus influence patient treatment selection. The aim of the study was to evaluate whether cardiovascular comorbidities affect PAE outcomes. METHODS: Retrospective subset analysis of the UK Registry of Prostate Artery Embolisation (UK-ROPE) database was performed with patients who had a full documented past medical histories including hypertension, diabetes, coronary artery disease (CAD), diabetes and smoking status as well as international prostate symptom score (IPSS) at baseline and at 12 months. Multiple regression was performed to assess for any significant predictors. RESULTS: Comorbidity data were available for 100/216 patients (mean age 65.8 ± 6.4 years), baseline IPSS 20.9 ± 7.0). Regression analysis revealed that the presence of hypertension (53.7% IPSS reduction vs. absence 51.4%, p = 0.94), diabetes (52.6% vs. absence 52.1%, p = 0.6), CAD (59.2% vs. absence 51.4%, p = 0.95), no comorbidities (49.8% vs. any comorbidity present 55.3%, p = 0.66), smoking status (non-smoker, 52.6%, current smoker, 61.5%, ex-smoker, 49.8%, p > 0.05), age (p = 0.52) and baseline Qmax (p = 0.41) did not significantly impact IPSS reduction at 12 months post-PAE. Baseline prostate volume significantly influenced IPSS reduction (≥ 80 cc prostates, 58.9% vs. < 80 cc prostates 43.2%, p < 0.05). CONCLUSION: The presence of cardiovascular comorbidities/smoking history does not appear to significantly impact PAE symptom score outcomes at 12 months post procedure. Our findings suggest that if the prostatic artery can be accessed, then clinical success is comparable to those without cardiovascular comorbidities.

Percutaneous cryoablation of renal tumours: outcomes from 171 tumours in 147 patients.

OBJECTIVE: To evaluate the technical and oncological efficacy of an image-guided cryoablation programme for renal tumours. PATIENTS AND METHODS: A prospective analysis of technical and radiological outcomes was undertaken after treatment of 171 consecutive tumours in 147 patients. Oncological efficacy in a subset of 125 tumours in 104 patients with >6 months' radiological follow-up and a further subset of 62 patients with solitary, biopsy-proven renal carcinoma was also analysed. Factors influencing technical success, as determined by imaging follow-up, and complication rates were statistically analysed using a statistics software package and logistic regression analyses. RESULTS: No variables were found to predict subtotal treatment, although gender (P = 0.08), tumour size of >4 cm (P = 0.09) and central location of tumour (P = 0.07) approached significance. Upper pole location was the single variable that was found to predict complications (P = 0.006). Among the 104 patients (125 tumours), radiologically assessed at ≥6 months and with a mean radiological follow-up of 20.1 months, we found a single case of unexpected late local recurrence. CONCLUSION: Percutaneous image-guided cryoablation, at a mean of 20.1 months' follow-up, appears to provide a safe and effective treatment option with a low complication rate. Anteriorly sited tumours should not be considered a contraindication for percutaneous image-guided cryoablation.

Trabecular bone density distribution in the scapula of patients undergoing reverse shoulder arthroplasty.

BACKGROUND: To improve implant survival after reverse shoulder arthroplasty (RSA), surgeons need to maximize screw fixation. However, bone density variation and distribution within the scapula are not well understood as they relate to RSA. The three columns of bone in the scapula surrounding the glenoid fossa are the lateral border, the base of the coracoid process, and the spine of the scapula. In our previous study by Daalder et al on cadaveric specimens, the coracoid column was significantly less dense than the lateral border and spine. This study's objective was to verify whether these results are consistent with computer tomography (CT) scan information from patients undergoing RSA. METHODS: Two-dimensional axial CT images from twelve patients were segmented, and a three-dimensional digital model of the scapula was subsequently created using Mimics 17.0 Materialise Software (Leuven, Belgium). Hounsfield unit (HU) values representing cortical bone were filtered out to determine the distributions of trabecular bone density. An analysis of variance with post hoc Bonferroni tests determined the differences in bone density between the columns of bone in the scapula. RESULTS: The coracoid superolateral (270 ± 45.6 HU) to the suprascapular notch was significantly less dense than the inferior (356 ± 63.6 HU, P = .03, ds = 1.54) and anterosuperior portion of the lateral border (353 ± 68.9 HU, P = .04, ds = 1.42) and the posterior (368 ± 70 HU, P = .007, ds = 1.65) and anterior spine (370 ± 78.9 HU, P = .006, ds = 1.54). DISCUSSION/CONCLUSION: The higher-density bone in the spine and lateral border compared with the coracoid region may provide better bone purchase for screws when fixing the glenoid baseplate in RSA. This is in agreement with our previous study and indicates that the previous cadaveric results are applicable to clinical CT scan data. When these studies are taken together, they provide robust evidence for clinical applications, including having surgeons aim screws for higher-density regions to increase screw fixation, which may decrease micromotion and improve implant longevity.

The First 48 Consecutive Patients with 3-Year Symptom Score Follow-Up Post-Prostate Artery Embolization (PAE) at a Single-Centre University Hospital.

INTRODUCTION: Few studies on prostate artery embolization (PAE) follow patients up after 12 months. We aimed to evaluate the symptomatic efficacy of PAE in our patient cohort at 3 years. METHOD: A total of 48 consecutive patients undergoing PAE from June 2012 to August 2014 were included in this retrospective study. All patients underwent formal urodynamics to confirm bladder outflow obstruction prior to PAE. International Prostate Symptom Score (IPSS) was performed at baseline, 3 months, 12 months and 3 years post-PAE. RESULTS: Mean patient age was 65.6 ± 7.4, prostate volume 99.1 ± 56.6 cm3, IPSS 23.5 ± 6.0, quality-of-life score 4.6 ± 0.9, Qmax 8.4 ± 2.8 ml/s, post-void residual volume 185.8 ± 55.6 ml. Technical success (bilateral embolization) was achieved in 43 out of 48 cases (89.6%). 11/39 bilateral PAE patients completing follow-up (2 died, 2 lost to follow-up) underwent surgery, indicating a 71.8% clinical success rate at 3 years. No significant change was demonstrated in IPSS or QOL between 1 and 3 years for patients free from surgical intervention (IPSS 8.3 vs 10.0, p = 0.09 and QOL 1.3 vs 1.5, p = 0.23). 3/11 patients undergoing surgery had a prominent 'ball-valve' median lobe, and 1/11 patients had a high bladder neck elevation contributing to symptoms. CONCLUSION: Clinical success post-PAE remains high with few patients opting for surgery or experiencing a worsening of symptoms after 12 months.

Phonological milestones for African American English-speaking children learning mainstream American English as a second dialect.

PURPOSE: This study provides milestones for phonological development in African American English (AAE) speakers who are learning Mainstream American English (MAE) as a second dialect. METHOD: The Dialect Sensitive Language Test (DSLT; H. Seymour, T. Roeper, & J. G. de Villiers, 2000) was administered to a nationwide sample of typically developing children ages 4 through 12: 537 speakers of AAE as a first dialect and 317 speakers of MAE as a first dialect. DSLT items tested all consonant segments and many clusters of MAE in initial and final position. The age at which each dialect group reached 90% criterion for each segment in each position was compared. RESULTS: Several phonetic elements that are contrastive between the dialects (i.e., differentiate the dialects) in word-final position were found to be similar in the 2 groups in word-initial position. Only /eth/ was contrastive in both positions. We confirm the later acquisition of certain phonological segments and structures by AAE speakers compared to MAE speakers and report their earlier mastery of other elements of MAE phonology. CONCLUSION: Both segmental and phonotactic development show different trajectories for AAE and MAE. Thus, initial diagnosis of impairment for AAE children should focus only on mastery of noncontrastive segments and structures that share a similar developmental profile for the 2 dialect groups.

Acute-onset abdominal pain in a woman in her 30s.

CLINICAL INTRODUCTION: A woman in her 30s presented to the emergency department with sudden-onset abdominal pain with hypotension and tachycardia. She gave a history of congenital heart disease for which she had previously undergone multiple operations. On examination she demonstrated right upper quadrant tenderness. She underwent an urgent multiphase CT (figure 1A-C).heartjnl;105/4/275/F1F1F1Figure 1(A) Arterial phase coronal CT. (B) Arterial phase axial CT. (C) Portal venous phase axial CT. QUESTION: What is the underlying liver pathology?Hepatocellular adenomaCholangiocarcinomaHepatocellular carcinomaFocal nodular hyperplasiaHepatoblastoma.

Mathematical and empirical proof of principle for an on-body personal lift augmentation device (PLAD).

In our laboratory, we have developed a prototype of a personal lift augmentation device (PLAD) that can be worn by workers during manual handling tasks involving lifting or lowering or static holding in symmetric and asymmetric postures. Our concept was to develop a human-speed on-body assistive device that would reduce the required lumbar moment by 20-30% without negative consequences on other joints or lifting kinematics. This paper provides mathematical proof using simplified free body diagrams and two-dimensional moment balance equations. Empirical proof is also provided based on lifting trials with nine male subjects who executed sagittal plane lifts using three lifting styles (stoop, squat, free) and three different loads (5, 15, and 25kg) under two conditions (PLAD, No-PLAD). Nine Fastrak sensors and six in-line strap force sensors were used to estimate the reduction of compressive and shear forces on L4/L5 as well as estimate the forces transferred to the shoulders and knees. Depending on lifting technique, the PLAD applied an added 23-36Nm of torque to assist the back muscles during lifting tasks. The peak pelvic girdle contact forces were estimated and their magnitudes ranged from 221.3+/-11.2N for stoop lifting, 324.3+/-17.2N for freestyle lifts to 468.47+/-23.2N for squat lifting. The PLAD was able to reduce the compression and shear forces about 23-29% and 7.9-8.5%, respectively.