Preliminary Evidence of an Association Between ADHD Medications and Diminished Bone Health in Children and Adolescents.

BACKGROUND: The US Centers for Disease Control and Prevention estimate that 3.5 million children use psychotropic drugs for attention-deficit hyperactivity disorder (ADHD). With an increase in use of these types of drugs, thorough understanding of their potential side effects on the growing skeleton is needed. The purpose of this study was to determine whether there is an association between use of ADHD medication and diminished bone health. METHODS: Three waves of the National Health and Nutrition Examination Survey public-use data set, collected from 2005 through 2010, were compiled for this study (N=5315). Bone health was measured using dual-energy x-ray absorptiometry scans, which were performed for participants aged 8 to 17 years to determine bone mineral density (BMD) for 3 regions: (1) total femur; (2) femoral neck; and (3) lumbar. Use of ADHD medications was determined by self-reported responses to questions regarding prescription drug use, which were answered by either the respondent or the respondent's parent or guardian. Multiple statistical techniques were used to produce estimates of association between ADHD medication use and z score age and sex standardized BMD measures, including survey adjusted univariate, survey adjusted multiple linear regression, and generalized estimating equations with a propensity-matched subsample (N=1967). Multivariate models adjusted for covariates including time period, age, sex, race/ethnicity, family income to poverty ratio, and total number of prescription medications. RESULTS: Conservative estimates of the difference in standardized BMD measures between the ADHD medication group and the nonmedicated group range from -0.4855 (±0.27; P<0.001) for total femoral, -0.4671 (±0.27; P<0.001) for femoral neck, and -0.3947 (±0.29; P<0.01) for lumbar. Significantly more children on ADHD medications versus match subjects on no medication had BMDs with in osteopenic range (38.3% vs. 21.6%, P<0.01). DISCUSSION: The findings suggest that there are real and nontrivial differences in BMD for children and adolescents taking ADHD medications, as compared with similar children not taking any prescription medications. Prescribing physicians and parents should be aware of potential bone health risks associated with these medications. LEVEL OF EVIDENCE: Level III-case-control study.

Cast saw burns: evaluation of simple techniques for reducing the risk of thermal injury.

BACKGROUND: Although a routine practice in all orthopaedic clinics, the use of cast saws is not without risk of thermal and abrasive injury to patients. This study investigates the use of readily available supplies for reducing oscillating saw blade operating temperatures. METHODS: An oscillating cast saw blade and an adhesive thermocouple fixed to the blade were uniformly heated and subsequently cooled from 70 °C to 45 °C using 6 different methods. Variables tested included the use of water applied with cotton cast padding or gauze dressing, 70% isopropyl alcohol applied with cotton cast padding, gauze dressing, or commercially available alcohol pads, and ultrasound gel applied with gauze dressing. All methods were tested with either the cast saw off or the saw and vacuum running. Statistical analysis included a 2-way analysis of variance to compare conditions with the cast saw off versus on and Tukey-adjusted pairwise comparisons of individual variables within each group. RESULTS: Cast saw blade cooling in ambient air required 114.2 seconds, whereas oscillating the blade and using the vacuum reduced the time to 14.6 seconds. Applying 70% isopropyl alcohol with a commercially available pad or ultrasound gel on a gauze dressing only required 9.0 and 10.2 seconds, respectively. Cooling with water or 70% isopropyl alcohol applied with either gauze dressing or cotton cast padding ranged from 4.8 to 7.4 seconds. CONCLUSIONS: At rest, the cast saw blade required almost 2 minutes to return to safe operating temperatures after being heated to 70 °C. Running the saw and vacuum resulted in significantly faster cooling across all measured variables. Of all methods tested, cooling with 70% isopropyl alcohol using gauze or cast padding or cooling with water on gauze resulted in the fastest responses. As a result, this study suggests that the routine use of any of these 3 methods would significantly decrease the risk of patient discomfort and thermal injury during cast cutting. CLINICAL RELEVANCE: Provide simple method for decreasing risk of thermal injury when removing casts.

Functional results after surgical treatment for congenital knee dislocation.

BACKGROUND: Congenital knee dislocation (CDK) is a rare congenital deformity, which often requires surgery for treatment. Little objective data exist characterizing the outcome of patients who require operative treatment for this condition. The purposes of this study were to objectively evaluate the functional, clinical, and gait outcomes of patients who underwent surgical treatment of CDK; and compare the results of outcome between 2 surgical approaches for this condition: quadricepsplasty and femoral shortening. METHODS: We performed a retrospective review of all patients (7) treated surgically for CDK. Patients were evaluated at an average follow-up of 12+6 years. Each patient underwent a clinical examination, functional evaluation using the Lysholm Knee Questionnaire and Pediatric Outcomes Data Collection Instrument, and a 3-dimensional gait evaluation. The results of the total group were compared with normal controls. Additionally, results of the patients treated with quadricepsplasty were compared with patients treated with femoral shortening. RESULTS: Total knee range of motion for the entire group averaged 112 degrees, with 8 of the 9 knees having flexion>90 degrees. Seven of the 9 knees were found to have some degree of instability on examination, yet none of the patients reported using any form of brace for ambulation. Functional evaluation showed good knee specific and overall function, comparable to normal controls. There were no differences in clinical or functional outcomes between the 2 surgical approaches. Gait analysis revealed a stiff-knee gait pattern to the congenital knee dislocation group, as compared with normal controls, and subtle differences in knee function between the surgical approaches. CONCLUSIONS: The function of patients after surgical treatment for CDK seems to be quite good compared with normal controls. Good knee specific and overall function scores are reported with limitations seen only in higher demand activities. Despite instability of the knee noticed on clinical examination, patients ambulate without braces and have a functional knee range of motion. Little difference in outcome was seen between the 2 surgical approaches used to treat this condition. LEVEL OF EVIDENCE: Therapeutic Study, Level III.

Neuropathic lower extremity pain following Dunn-McCarthy instrumentation.

STUDY DESIGN: Retrospective review of all patients with intact spinal cords, who had posterior spinal fusion (PSF) to the pelvis with Dunn-McCarthy instrumentation. Inclusion criteria were communicative patients with Dunn-McCarthy instrumentation, functioning spinal cords, and sensate lower extremities. We excluded patients with myelomeningocele or spinal cord injury because they are physiologically unable to develop neuropathic lower extremity pain. We distinguished neuropathic lower extremity pain from positional discomfort by eliminating patients whose symptoms resolved in the first postoperative month and patients whose pain persisted greater than a month but did not require treatment or further investigation. OBJECTIVE: To determine the incidence and clinical course of neuropathic lower extremity pain following PSF with Dunn-McCarthy instrumentation. SUMMARY OF BACKGROUND DATA: The Dunn-McCarthy technique for instrumented PSF to the pelvis places a rod in close proximity to the L5 nerve root and anterior neurovascular structures. We have treated several patients who developed neuropathic lower extremity pain following PSF with Dunn-McCarthy instrumentation. RESULTS: Seven of 49 patients developed neuropathic pain in a lower extremity after PSF to the pelvis with Dunn-McCarthy instrumentation. Six patients were managed with Neurontin, and 1, with Valium. Two patients were offered removal of their implants, but their symptoms resolved before resection was performed. CONCLUSION: Pelvic fixation with Dunn-McCarthy instrumentation was associated with a 14% incidence of severe, unilateral neuropathic lower extremity pain.

Changes in intraocular pressure due to surgical positioning: studying potential risk for postoperative vision loss.

STUDY DESIGN: Parallel group design. OBJECTIVE: Compare the intraocular pressure responses in the prone flat versus prone Trendelenburg's position. SUMMARY OF BACKGROUND DATA: Postoperative vision loss (PVL) complicates approximately 0.05% of spine surgeries. Prone positioning is considered a risk factor because it increases intraocular pressure, which may decrease perfusion pressure to the optic nerve (perfusion pressure = mean arterial pressure - intraocular pressure [IOP]). The prone Trendelenburg's position is often used during spine surgery; however, its effect on optic nerve perfusion is unknown. The purpose of this study is to compare the IOP responses in the prone flat versus prone Trendelenburg's positions to determine if prone Trendelenburg's position also risks PVL. METHODS: Twenty subjects randomized into 2 groups. Group 1 lay in the prone flat position (0 degrees). Group 2 lay in the prone Trendelenburg's position (-7 degrees). IOPs were measured with a hand-held applanation tonometer while seated, 1 minute after assuming the group's position (Time 0), and at 10-minute intervals for 60 minutes. RESULTS: The differences in mean IOPs with respect to positions and time were significant (P = 0.0001, P = 0.000). There was a significant difference between sitting and all other times for both groups. In Group 1, there was a significant difference in IOP between Time 0 and all other times prone flat (P < 0.05). In Group 2, there was a significant difference in IOP between Time 0 all other times prone Trendelenburg (P < 0.05). CONCLUSION: IOP increases in the prone Trendelenburg's position, and when combined with other factors, may be a risk factor for PVL. The pathophysiology is discussed and suggestions for clinicians are made.