William C. Lippert

Optimal Intramuscular Needle-Penetration Depth

OBJECTIVE. The US Centers for Disease Control and Prevention has needle-length recommendations for intramuscular vaccinations in the thigh and shoulder on the basis of the age of the child. Underpenetration of the intramuscular layer with short needles has been documented; however, few studies have focused on the risk for overpenetration of the intramuscular level with needles that are too long. The purpose of this study was to determine the optimal needle length for intramuscular vaccination of children of various ages and sizes at the shoulder and thigh levels by using MRI and computed tomography scan measurements. METHODS. A total of 250 MRI and computed tomography scans of shoulders and thighs of children who were 2 months to 18 years of age at a large childrens hospital were reviewed. The thicknesses of the subcutaneous fat tissue and muscle layers were measured. Measurements were correlated with age and weight, and regression analysis was performed. RESULTS. Use of the Centers for Disease Control and Preventions recommended 1- and 1 ¼-in needles for intramuscular vaccination in the thigh of children ≥1 year of age would result in 11% (11 of 100) and 39% (34 of 88) overpenetration, respectively, with a minimal risk for underpenetration at 2% (2 of 100). Patients with vaccinations in the shoulder with the Centers for Disease Control and Prevention–recommended \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({5}/{8}\) \end{document}-, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({7}/{8}\) \end{document}-, and 1-in needles would experience 11% (16 of 150), 55% (83 of 150), and 61% (92 of 150) overpenetration, respectively. CONCLUSIONS. There is a substantial risk for overpenetration of the intramuscular layer when using current Centers for Disease Control and Prevention recommendations for vaccination needle lengths. We recommend a revision of the needle-length guidelines for thigh and shoulder injections to minimize the risk for needle overpenetration on the basis of the variability observed in the fat thickness.

Quantification of humeral head deformity following neonatal brachial plexus palsy.

BACKGROUND Neonatal brachial plexus palsy frequently leads to glenohumeral dysplasia if neurological recovery is incomplete. Although glenoid retroversion and glenohumeral subluxation have been well characterized, humeral head deformity has not previously been quantified. Nonetheless, humeral head flattening is described as a contraindication to joint contracture release and external rotation tendon transfers. This study describes a novel technique for objectively quantifying humeral head deformity with use of magnetic resonance (MR) imaging and correlates the humeral head deformity with clinical and radiographic outcomes following joint rebalancing surgery. METHODS Magnetic resonance images of thirty-two children (age, 0.7 to 11.5 years) with neonatal brachial plexus palsy were retrospectively reviewed. Passive shoulder external rotation and Mallet scores were reviewed before joint rebalancing surgery and at a minimum clinical follow-up interval of two years. The humeral head skewness ratio on preoperative and postoperative axial MR images was defined as the ratio of anterior to posterior humeral head area, and this ratio was compared between affected and unaffected shoulders and with the glenoid version angle, posterior subluxation of the humeral head, and clinical parameters before and after surgery with use of paired t tests and Spearman correlation. Intraobserver and interobserver reliability of MR image measurements was determined. RESULTS Measurements of the skewness ratio on the affected side had moderate to substantial intraobserver reliability (0.53 to 0.72) and substantial interobserver reliability (0.65 to 0.71). Preoperatively, the skewness ratio of the affected humeral head (mean, 0.76; range, 0.54 to 1.03) differed significantly from the ratio in the contralateral shoulder (p<0.05) and was significantly associated with the glenoid version angle (p<0.05) and posterior subluxation of the humeral head (p<0.05). Remodeling of the affected humeral head was observed postoperatively, with a significant improvement in the skewness ratio (p<0.05). However, there were no significant correlations between the preoperative skewness ratio and postoperative clinical outcomes. CONCLUSIONS Humeral head deformity in neonatal brachial plexus palsy correlated with other measures of glenohumeral dysplasia and could be reliably and objectively quantified on MR imaging with use of the skewness ratio. The humeral head deformity can remodel following joint rebalancing surgery, and such a deformity alone does not preclude a successful outcome after surgical attempts to restore glenohumeral congruity.

The intrarater and interrater reliability of glenoid version and glenohumeral subluxation measurements in neonatal brachial plexus palsy.

Background: Progressive and disabling glenohumeral dysplasia commonly occurs as a secondary deformity in children with neonatal brachial plexus palsy (NBPP). A number of methods for quantifying glenohumeral dysplasia are currently in use; however, the most commonly reported quantitative measures have yet to be validated. The present study assesses the intrarater and interrater reliability of the glenoid version angle (GVA) and percent of the humeral head anterior to the scapular line (PHHA) measurements on axial magnetic resonance images. Methods: Axial magnetic resonance images of the shoulder girdle of 25 children with NBPP were selected to represent a wide range of glenohumeral dysplasia severity. An axial image was preselected for each measurement. Six examiners (3 orthopaedic surgeons, 2 musculoskeletal radiologists, and an epidemiologist) digitally measured the GVA and PHHA on each image twice, with each measurement separated by 2 to 14 days and the order of image presentation placed in a different arrangement for each measurement set. Intrarater and interrater reliability was assessed with the intraclass correlation coefficient (ICC). Measurement errors for the GVA and PHHA measurements and the variances associated with the scapular and glenoid lines were calculated. Results: Using the Fleiss criteria, intrarater reliability was excellent, with ICCs averaging 0.909 (95% CI: 0.840, 0.940) for GVA and 0.891 (95% CI: 0.815, 0.921) for PHHA. Interrater reliability was excellent, with ICCs of 0.848 (95% CI: 0.788, 0.909) for GVA and 0.874 (95% CI: 0.815, 0.934) for PHHA. The GVA and PHHA measurement errors were ±6.4 degrees and ±7.2%, respectively. In a subset of 141 images measured, the between-image variance in the scapular line was greater than the glenoid line by a 1.61:1 ratio. Conclusions: The present study demonstrates excellent intrarater and interrater reliability of standard measurements of glenohumeral dysplasia in NBPP. The measurement errors for both measurements were comparable with other standard measures (eg, Cobb angle). The scapular line exhibited a greater variance than the glenoid line, which identifies an opportunity for improvement in the GVA measurement. Level of Evidence: Diagnostic study; level III.

Salter-Harris type III fractures of the distal femur: plain radiographs can be deceptive.

Background Salter-Harris (SH) III fractures of the distal femur, although rare, can have devastating effects. The purposes of this study were to: (1) compare the intra-articular fracture displacement measured on plain x-ray and magnetic resonance imaging (MRI) or computed tomography (CT) scan and (2) report the outcomes of patients with a SH III fracture of the distal femur. Methods All SH III distal femur fractures treated at a large Childrens Hospital with a Level I Pediatric Trauma Center between 1995 and 2006 were retrospectively reviewed. A total of 14 patients (average age: 13 y, 11 mo; range: 7 y, 8 mo to 17 y, 11 mo) with an average follow-up time of 21.50 months (range: 2 to 47 mo) were included in this study. Fracture displacement on plain x-ray was compared with the fracture displacement measured on MRI or CT scan. The average time between the initial plain x-ray and MRI or CT scan was 37.48 days (range: 3 h to 6 mo). Results Plain x-rays significantly underestimated the displacement of SH III fractures versus MRI or CT scan. Six patients who had both plain x-ray and MRI or CT scan had a measured displacement of 0.42 mm and 2.70 mm, respectively (paired Student t test, P=0.005). Ten of the 14 patients (71%) had no physical limitations and full knee motion at their most recent follow-up visit. The treatment of 4 patients (29%) was changed based on the findings of the additional MRI or CT scan. Conclusions This study and earlier studies have shown a high rate of poor results with SH III fractures of the distal femur. This type of fracture pattern is extremely unstable and the true displacement is often underestimated by x-rays. Thus, it is strongly recommended that an MRI or CT scan be obtained on every SH III fracture of the distal femur. Moreover, any SH III fracture visible on plain radiographs should be treated with open reduction, internal fixation. Level of Evidence Level IV.

Meta-analysis of function after secondary shoulder surgery in neonatal brachial plexus palsy.

Background: Shoulder internal rotation contracture, active abduction, and external rotation deficits are common secondary problems in neonatal brachial plexus palsy (NBPP). Soft tissue shoulder operations are often utilized for treatment. The objective was to conduct a meta-analysis and systematic review analyzing the clinical outcomes of NBPP treated with a secondary soft-tissue shoulder operation. Methods: A literature search identified studies of NBPP treated with a soft-tissue shoulder operation. A meta-analysis evaluated success rates for the aggregate Mallet score (≥4 point increase), global abduction score (≥1 point increase), and external rotation score (≥1 point increase) using the Mallet scale. Subgroup analysis was performed to assess these success rates when the author chose arthroscopic release technique versus open release technique with or without tendon transfer. Results: Data from 17 studies and 405 patients were pooled for meta-analysis. The success rate for the global abduction score was significantly higher for the open technique (67.4%) relative to the arthroscopic technique (27.7%, P<0.0001). The success rates for the global abduction score were significantly different among sexes (P=0.01). The success rate for external rotation was not significantly different between the open (71.4%) and arthroscopic techniques (74.1%, P=0.86). No other variable was found to have significant impact on the external rotation outcomes. The success rate for the aggregate Mallet score was 57.9% for the open technique, a nonsignificant increase relative to the arthroscopic technique (53.5%, P=0.63). Data suggest a correlation between increasing age at the time of surgery and a decreasing likelihood of success with regards to aggregate Mallet with an odds ratio of 0.98 (P=0.04). Conclusions: Overall, the secondary soft-tissue shoulder operation is an effective treatment for improving shoulder function in NBPP in appropriately selected patients. The open technique had significantly higher success rates in improving global abduction. There were no significant differences in the success rates for improvement in the external rotation or aggregate Mallet score among these surgical techniques. Level of Evidence: Level IV—meta-analysis.

Documentation of postoperative pain in the neonatal brachial plexus palsy population.

AIMS AND OBJECTIVES To assess postoperative pain management in neonatal brachial plexus palsy children who underwent a primary nerve repair, release only and/or a release and transfer procedure. BACKGROUND Previous studies have noted pain management inadequacies in postoperative pain management in certain paediatric populations. However, this is the first study to focus on postoperative pain management in this particular population. METHODS Seventy-five patients, who underwent a primary nerve repair, release only and/or a release and transfer procedures at our institution, were reviewed. Postoperative pain management was assessed on a patient and drug administration level through appropriate pain scale use; appropriate dosage for the medication prescribed; appropriate reassessment of pain following medication administration; and complications leading to a longer hospital stay. RESULTS Based on our institutions guidelines following drug administration, 64 patients were not appropriately reassessed for pain. Based on the drugs duration following drug administration, 40 patients were not appropriately reassessed for pain. Twenty-eight per cent of all medication administrations were not properly reassessed for pain based on the drugs duration and 62% of the time based on our institutions guidelines. Fifty per cent of all medication administrations were not properly dosed and 51 patients were not appropriately dosed at least once during their hospital stay. Pain scales were documented incorrectly 20% of the time and administered improperly to 13 patients. CONCLUSIONS Opportunities for improvement in postoperative pain management in the paediatric population - particularly those with neonatal brachial plexus palsy - exist. RELEVANCE TO CLINICAL PRACTICE Findings from this study demonstrate that healthcare professionals may have (1) insufficient knowledge regarding pain and/or (2) inadequate direction and guidance to appropriately assess and document pain in the paediatric population. Improvements for these individual healthcare professionals and clinical settings are needed to overcome postoperative pain management issues in the future.

Methemoglobinemia in an HIV patient

He had restarted his home dapsone prophylaxis, but his dyspnea worsened and his urine became dark.

Risk Factors for Brachial Plexus Birth Injury

Over the course of decades, the incidence of brachial plexus birth injury (BPBI) has increased despite advances in healthcare which would seem to assist in decreasing the rate. The aim of this study is to identify previously unknown risk factors for BPBI and the risk factors with potential to guide preventative measures. A case control study of 52 mothers who had delivered a child with a BPBI injury and 132 mothers who had delivered without BPBI injury was conducted. Univariate, multivariable and logistic regressions identified risk factors and their combinations. The odds of BPBI were 2.5 times higher when oxytocin was used and 3.7 times higher when tachysystole occurred. The odds of BPBI injury are increased when tachysystole and oxytocin occur during the mother’s labor. Logistic regression identified a higher risk for BPBI when more than three of the following variables (>30 lbs gained during the pregnancy, stage 2 labor >61.5 min, mother’s age >26.4 years, tachysystole, or fetal malpresentation) were present in any combination.