Predicting Failure After Primary Arthroscopic Bankart Repair: Analysis of a Statistical Model Using Anatomic Risk Factors.

PURPOSE: The purpose of this study was to establish and analyze a simplified scoring system based on anatomic imaging measurements to predict recurrent instability after primary arthroscopic shoulder capsulolabral repair. METHODS: All patients undergoing primary arthroscopic anterior capsulolabral repair of the shoulder were reviewed. Patients were contacted and charts were reviewed for endpoint of recurrent instability and return to prior level of activity. Predictive variables for recurrent instability studied included age, sex, amount of glenoid bone loss, intact anterior articular arc (IAAA), glenohumeral tracking (off-track), contact sports and overhead sports participation. RESULTS: 540 patients met inclusion criteria and follow-up data with magnetic resonance imaging data were available for 337 shoulders. Average follow-up was 6.2 years(range 3.4-9.3 years). Symptomatic recurrent instability occurred in 102 patients (30.3%) and 68% of contacted patients returned to pre-injury activities. In univariate analysis, age under 21 years, off-track lesions, IAAA <150°, and glenoid bone loss (GBL) of 10% or greater displayed an increased risk of recurrent instability. Multivariable analysis showed these factors remained significant: age <21 (odds ratio [ratio] 2.37), off-track glenoid (OR 2.86), IAAA <150 (OR 3.90), and GBL ≥10% (OR 7.47). A scoring system assigning 1 point each for age and off-track lesions, 2 points for IAAA <150, and 4 points for GBL >10% yielded 79% sensitivity, 75% specificity, 58% positive predictive value, and 89% negative predictive value using a probability value of 20 percent for recurrent instability. CONCLUSION: At mid-term follow-up, recurrent shoulder instability following primary arthroscopic anterior capsulolabral repair was 30% in this series. Younger age, glenoid bone loss of 10% or more, IAAA <150° and off-track glenoid lesion conferred the greatest risk for postoperative instability. We propose a scoring system assigning 1 point for age, 1 point for off-track lesions, 2 points for IAAA <150, and 4 points for GBL >10%. This schema demonstrated moderate accuracy for predicting recurrent instability when using a cutoff threshold score above 2 points for failure. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Comparison of Intraoperative Fluoroscopic Dunn View With Magnetic Resonance Imaging to Determine Femoral Version.

PURPOSE: To compare femoral version measured with a fluoroscopic Dunn view taken at the time of hip arthroscopy with values derived from axial magnetic resonance imaging (MRI) scans. METHODS: Of 159 hip arthroscopies performed from January 2014 through March 2015, 50 patients had magnetic resonance imaging (MRI) scans with a protocol that incorporates femoral version analysis. Dunn views are performed as a routine part of the preoperative fluoroscopic examination at the time of arthroscopy. Femoral version was measured from the fluoroscopic views and compared with values calculated from axial MRI images. The measurements were compared with a paired t test for difference in means, the intraclass correlation coefficient (ICC) for reliability, and the limits of agreement method of Bland and Altman. RESULTS: There was a very small but statistically significant difference between the measurement on fluoroscopic Dunn view and the value on axial MRI (mean difference, 1.4°, P = .03). The ICC was 0.809 (P < .0001), indicating substantial agreement. By the Bland and Altman method, the 95% limits of agreement for fluoroscopic versus MRI measurement were -7.6 to 10.4, with no significant difference in variance by Pitman test (P = .526). CONCLUSIONS: With careful attention to technique, the fluoroscopically simulated Dunn view can be used to measure femoral version with acceptable accuracy and obviates the need for repeat 3-dimensional imaging for patients who already have an MRI scan without version analysis. LEVEL OF EVIDENCE: Level II, testing of previously developed diagnostic criteria with a gold standard.

Volar plate fixation failure for volar shearing distal radius fractures with small lunate facet fragments.

PURPOSE: To determine the percentage of AO B3 distal radius fractures that lose reduction after operative fixation and to see whether fracture morphology, patient factors, or fixation methods predict failure. We hypothesized that initial fracture displacement, amount of lunate facet available for fixation, plate position, and screw fixation would be significant risk factors for loss of reduction. METHODS: A prospective, observational review was conducted of 51 patients (52 fractures) with AO B3 (volar shearing) distal radius fractures treated operatively between January 2007 and June 2012. We reviewed a prospective distal radius registry to determine demographic data, medical comorbidities, and physical examination findings. Radiographs were evaluated for AO classification, loss of reduction, length of volar cortex available for fixation, and adequacy of stabilization of the lunate facet fragment with a volar plate. Preoperative data were compared between patients who maintained radiographic alignment and those with loss of reduction. A multivariate logistic regression analysis was completed to determine significant predictors of loss of reduction. RESULTS: Volar shearing fractures with separate scaphoid and lunate facet fragments (AO B3.3), preoperative lunate subsidence distance, and length of volar cortex available for fixation were significant predictors for loss of reduction; the latter was significant in multivariate analysis. Plate position and number of screws used to stabilize the lunate facet were not statistically different between groups. CONCLUSIONS: Patients with AO B3.3 fractures with less than 15 mm of lunate facet available for fixation, or greater than 5 mm of initial lunate subsidence, are at risk for failure even if a volar plate is properly placed. In these cases, we recommend additional fixation to maintain reduction of the small volar lunate facet fracture fragments in the form of plate extensions, pins, wires, suture, wire forms, or mini screws. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Detection of pars injury by SPECT in patients younger than age 10 with low back pain.

BACKGROUND: Evaluation of extension-based low back pain in young athletes with suspected pars injury may include a referral for skeletal single photon emission computed tomography (SPECT). However, the diagnostic yield of this technique in children with low back pain before the age of 10 years remains uncertain. We examined a series of consecutive SPECT scans to address this question. MATERIALS AND METHODS: A retrospective review of department databases revealed 107 consecutive skeletal Tc-99m MDP SPECT scans performed between January 1, 2007 and December 31, 2009 in children less than 10 years of age. Of these, 72 studies were performed for a referral diagnosis of back pain. There were 43 girls (44 studies) and 28 boys (28 studies). The mean age was 7.2 years (range, 1.9 to 9.9 y). All SPECT scans were reviewed and positive findings documented. In addition, all available anatomic imaging, imaging reports (computed tomography, magnetic resonance, and x-ray) and clinical notes were reviewed, and results were compared with those of SPECT studies. RESULTS: Of the 72 SPECT studies, 35 (49%) identified a focal area in the spine of abnormal increased uptake, with 17 in the region of the pars interarticularis. With additional imaging, 1 case was demonstrated not to be a pars injury (computed tomography showed a transverse process fracture) and 2 patients with negative SPECT scans were shown to have pars injuries that SPECT scan had not detected, for a total of 18 pars injuries (25%) in this cohort. Reported participation in gymnastics or football was related to pars injury (odds ratio 4.3, P=0.04). CONCLUSIONS: Pars injury was found in 25% of children referred for SPECT scan with back pain below 10 years of age. SPECT scan was highly sensitive for this injury as well as in identifying other potential sites of pathology, and should be considered in the workup of persistent low back pain in young children. LEVEL OF EVIDENCE: Level II, diagnostic study.

Communication for all your patients.

Because communication is something that is often taken for granted, many people do not consciously think about communication habits and behaviors. When patients are questioned concerning important attributes of a doctor, they say they want someone who respects and listens to them. In a time of increasing malpractice litigation, physicians need to examine their communication skills. In an increasingly more diverse world, social and cultural beliefs, attitudes, and behaviors have a considerable effect on the health of communities. Patient safety, satisfaction, and successful outcomes rely on understanding the patient's medical and cultural needs. The concept of becoming a "cultural anthropologist" is improbable, but becoming aware of the demographics of the community in which the physician serves will improve communication and lead to improved patient and physician satisfaction, better patient compliance, and improved health outcomes.

Type II supracondylar humerus fractures: can some be treated nonoperatively?

BACKGROUND: The range of injury severity that can be seen within the category of type II supracondylar humerus fractures (SCHFs) raises the question whether some could be treated nonoperatively. However, the clinical difficulty in using this approach lies in determining which type II SCHFs can be managed successfully without a surgical intervention. METHODS: We reviewed clinical and radiographic information on 259 pediatric type II SCHFs that were enrolled in a prospective registry of elbow fractures. The characteristics of the patients who were treated without surgery were compared with those of patients who were treated surgically. Treatment outcomes, as assessed by the final clinical and radiographic alignment, range of motion of the elbow, and complications, were compared between the groups to define clinical and radiographic features that related to success or failure of nonoperative management. RESULTS: During the course of treatment, 39 fractures were found to have unsatisfactory alignment with nonoperative management and were taken for surgery. Ultimately, 150 fractures (57.9%) were treated nonoperatively, and 109 fractures (42.1%) were treated surgically. At final follow-up, outcome measures of change in carrying angle, range of motion, and complications did not show clinically significant differences between treatment groups. Fractures without rotational deformity or coronal angulation and with a shaft-condylar angle of >15 degrees were more likely to be associated with successful nonsurgical treatment. A scoring system was developed using these features to stratify the severity of the injury. Patients with isolated extension deformity, but none of the other features, were more likely to complete successful nonoperative management. CONCLUSIONS: This study suggests that some of the less severe pediatric type II SCHFs can be successfully treated without surgery if close follow-up is achieved. Fractures with initial rotational deformity, coronal malalignment, and significant extension of the distal fragment are likely to fail a nonoperative approach. An algorithm using the initial radiographic characteristics can aid in distinguishing groups.

Bone mineral density and functional measures in patients with arthrogryposis.

BACKGROUND: Patients with arthrogryposis often report decreased ambulation and physical activity. Given that skeletal mineralisation is responsive to force, we identified the need to characterize bone mineral density and functional measures in this population, and conducted a cross-sectional study to establish a reference for future investigations. METHODS: Thirty consecutive patients aged 5 to 18 years with either the diagnosis of amyoplasia or nonsyndromic arthrogryposis with predominantly lower extremity involvement underwent bone densitometry testing, and lumbar spine Z-scores were calculated against an age and sex-matched control population as is customary in children. Pediatric outcomes data collection instrument (PODCI) and functional independence measure for Children (WeeFIM) assessment forms were completed. Mean Z-scores, PODCI, and WeeFIM scores were calculated. Statistical analysis was performed to compare lumbar spine Z-scores between patients divided by ambulatory status and to correlate WeeFIM and PODCI scores. RESULTS: Mean lumbar spine Z-score was -0.47, with 73% of Z-scores being <0. Mean Z-score among nonambulators or home ambulators was -1.05, as compared to a mean Z-score among limited and unlimited community ambulators of -0.14 with a trend toward significance (P=0.10), and a dose-response relationship between higher bone density and increasing ambulatory function. Mean WeeFIM self-care and mobility quotient scores were 67.5/100 and 70.9/100, respectively. PODCI normative scores were decreased for upper extremity (10/50), transfer/basic mobility (-17/50), and sports/physical function (4/50), but normal in pain/comfort (45/50) and happiness (49/50). A linear relationship was noted between functional ambulation level and WeeFIM quotient and PODCI normative scores. There was good correlation between WeeFIM mobility and PODCI transfers and basic mobility standardised scores (R=0.86). CONCLUSIONS: This is the first study to measure bone mineral density in children with arthrogryposis, and shows it to be lower than age-matched means, especially in patients with limited ambulation. Objective measures of functional ability (WeeFIM and PODCI) are decreased and demonstrate a linear relationship with ambulatory level. Further investigation is needed to quantify long-term effects of entering adulthood with below average bone mineral density in patients with arthrogryposis. LEVEL OF EVIDENCE: Level II.

The effects of surgical delay on the outcome of pediatric supracondylar humeral fractures.

BACKGROUND: Occasionally, the treatment of a pediatric supracondylar humeral fracture is delayed owing to lack of an available treating physician, necessitating transfer of the child, or delay in availability of an operating room. The purpose of this study is to prospectively evaluate whether delayed pinning of these fractures affects the outcome or number of complications. METHODS: We reviewed information that was prospectively collected on 145 pediatric supracondylar humeral fractures that were treated by closed reduction and percutaneous pinning, with a minimum follow-up of 8 weeks. To determine the effect of delayed treatment, we compared a group of fractures that was treated within the first 21 hours after their presentation to our urgent care center (Group A) with a group that was treated after more than 21 hours (Group B). We compared the following variables: need for open reduction, length of surgery, length of hospitalization, the presence of neurologic complications, vascular complications including compartment syndrome, pin tract infection, loss of fixation, final carrying angle, range of motion, and outcome. RESULTS: Overall, the mean time from presentation to surgery for both groups was 52 hours. This interval was greater for Gartland type II fractures (65 h) than for Gartland type III fractures (19 h) (P=0.00001). There was no need for an open reduction in either group. There were no significant differences between the groups regarding iatrogenic nerve injuries, vascular complications, compartment syndromes, surgical time, final carrying angle, range of motion, and outcome. CONCLUSIONS: The results of this prospective study found that a delay in pinning closed supracondylar humeral fractures in children did not lead to a higher incidence of open reduction or a greater number of complications. Although the urgency of treating any child with a supracondylar fracture should be individualized, our study suggests that most of these injuries can be managed safely in a delayed fashion without compromising the clinical outcome. We recommend careful monitoring of any patient with type 3 injury whose treatment is delayed. LEVEL OF EVIDENCE: II.

Beta-blocker subtypes and risk of low birth weight in newborns.

Beta-blockers are one of the most commonly prescribed classes of antihypertensive medications during pregnancy. Previous studies reported an association between beta-blocker exposure and intrauterine growth restriction. Whether some beta-blocker subtypes may be associated with higher risk is not known. This is a retrospective cohort study of pregnant women exposed to beta-blockers in the Kaiser Permanente Southern California Region between 2003 and 2014. Logistic regression models were used to evaluate association between exposure to different beta-blocker agents and risk of low fetal birth weights. In a cohort of 379 238 singleton pregnancies, 4847 (1.3%) were exposed to beta-blockers. The four most commonly prescribed beta-blockers were labetalol (n = 3357), atenolol (n = 638), propranolol (n = 489), and metoprolol (n = 324). Mean birth weight and % low birth weight (<2500 g) were 2926 ± 841 g and 24.4% for labetalol, 3058 ± 748 g and 18.0% for atenolol, 3163 ± 702 g and 13.3% for metoprolol, 3286 ± 651 g and 7.6% for propranolol, and 3353 ± 554 g and 5.2% for non-exposed controls. Exposure to atenolol and labetalol were associated with increased risks of infant born small for gestational age (SGA) (atenolol: adjusted OR 2.4, 95% CI: 1.7-3.3; labetalol: adjusted OR 2.9, 95% CI: 2.6-3.2). Risk of SGA associated with metoprolol or propranolol exposure was not significantly different from the non-exposed group (metoprolol: adjusted OR 1.5, 95% CI: 0.9-2.3; propranolol: adjusted OR 1.3, 95% CI: 0.9-1.9). Association between beta-blocker exposure and SGA does not appear to be a class effect. Variations in pharmacodynamics and confounding by indication may explain these findings.

Maximal Force Generated by Magnetically Controlled Growing Rods Decreases With Rod Lengthening.

OBJECTIVES: To evaluate the maximal force generated by magnetically controlled growing rods (MCGRs) at three different lengthened positions. SUMMARY OF BACKGROUND DATA: The introduction of MCGRs has been met with great enthusiasm by surgeons managing early-onset scoliosis. These devices offer the potential to decrease the cost and morbidity associated with repeated surgeries, compared to traditional growing rods. One potential negative consequences of growing rod treatments is the law of diminishing returns, where the spine length gained decrease with each subsequent lengthening. The cause of this phenomenon is unknown and probably multifactorial, yet it may be affected by the strength of the lengthening mechanism in the MCGRs. METHODS: Twelve MCGRs (90-mm actuator length) were obtained and tested to evaluate the maximal force generated at different lengths. The maximal lengthening force measured in pounds-of-force generated by each rod was recorded at expansion lengths of 0, 25, and 40 mm. Longitudinal analysis was performed using mixed effects linear regression to account for repeated measures and variability between individual implants. RESULTS: At 0 mm of actuator lengthening, the mean maximum force was 46.8 lb (standard deviation [SD] 2.06, range 43-50). At 25 mm of expansion, the mean maximum force was 44.9 lb (SD 2.48, range 39.4-49.5). At 40 mm of lengthening, the mean maximum force was 43.2 lb (SD 5.56, range 27.3-49.1). In the mixed effects linear model, there was a statistically significant decrease in the maximal force generated with progressive MCGR lengthening, at an average decrease of 0.089 lb of force (95% CI, 0.030-0.148; p = .003) per millimeter of lengthening. CONCLUSION: There is a small but statistically significant decrease in the maximal force generated by MCGR as the rods are lengthened. The decrease in force generated may result in diminished spine length gained with each subsequent MCGR lengthening. LEVEL OF EVIDENCE: Level IV.

Maternal and fetal outcomes in pregnant women with heart failure.

OBJECTIVES: The goal of this study is to report the prevalence, aetiology and clinical outcome of pregnant women with heart failure. METHODS: This is a retrospective community-based cohort study that included pregnant women in the Kaiser Permanente Health System between 2003 and 2014. Women with heart failure were identified using International Classification of Disease, Ninth Revision codes. Medical records were manually reviewed to confirm diagnosis and adjudicate outcomes. RESULTS: In a cohort of 385 935 pregnancies, 488 (0.13%) had a diagnosis of heart failure, corresponding to 126 cases per 100 000 pregnancies. Peripartum cardiomyopathy was the most common cause of heart failure, accounting for 333 (68.2%) cases. Preterm birth and caesarean delivery were more common in patients with heart failure. Neonatal death rate was higher in the heart failure group (1.0% vs 0.4%, p=0.03). Infants delivered to women with heart failure had lower birth weights (3112.0±774.0 g vs 3331.9±575.5 g, p<0.001) and lower Apgar score at 1 min (7.9±1.5 vs 8.3±1.1, p<0.001). Median follow-up was 6.2 years (IQR 3.2-9.2). During follow-up, 7 (1.4%) in the heart failure group and 423 (0.11%) in the control group died. Heart failure was associated with a 7.7-fold increase risk of death (adjusted HR 7.7, 95% CI 3.6 to 16.4, p<0.001). CONCLUSION: Heart failure during pregnancy is associated with unfavourable fetal outcomes including prematurity and low birth weight. While the overall mortality rate was low, pregnant women with heart failure carried an excess risk of death compared with controls.

Paper #26: Maximal Force Generated by Magnetically Controlled Growing Rods Decreases with Rod Lengthening.

The use of magnetically controlled growing rods (MCGR) has the potential to decrease the morbidity associated with repeated surgeries, yet, strength of the lengthening mechanism as it lengthens may have an impact on the length gained with each lengthening.We evaluated the maximal force generated by MCGR at 3 different lengthened positions and found an average decrease of 0.089 pounds per mm of additional length. This decrease may result in diminished spine length gained with each subsequent MCGR lengthening.

Warfarin use and the risk of mortality, stroke, and bleeding in hemodialysis patients with atrial fibrillation.

BACKGROUND: The optimal management of stroke prophylaxis in hemodialysis patients with atrial fibrillation is controversial. OBJECTIVE: The purpose of this study was to determine the risk of mortality, stroke, and bleeding associated with the use of warfarin in hemodialysis patients with atrial fibrillation. METHODS: This was a retrospective, population-based study of hemodialysis patients with atrial fibrillation between January 1, 2006, and September 30, 2015. Association of warfarin use with mortality, stroke, and bleeding was determined by propensity score-matched, Cox proportional hazard models. RESULTS: Among the 4286 patients with atrial fibrillation on hemodialysis, 989 (23%) were prescribed warfarin. Propensity score matching was used to identify 888 matched pairs with similar baseline characteristics. Warfarin use was associated with lower risk of all-cause death (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.69-0.84) and lower risk of ischemic stroke (HR 0.68, 95% CI 0.52-0.91). Warfarin use was not associated with a higher risk of hemorrhagic stroke (HR 1.2, 95% CI 0.6-2.2) or gastrointestinal bleeding (HR 0.97, 95% CI 0.77-1.2). The treatment effect was largest in the group with the best international normalized ratio control as measured by time in therapeutic range. Subgroup analyses showed warfarin use was associated with survival benefit in most subgroups. The 2 subgroups that did not benefit were patients with a history of hemorrhagic stroke and patients with concurrent aspirin use. CONCLUSION: Warfarin use is associated with lower all-cause mortality and ischemic stroke, without significantly increasing the risk of bleeding in hemodialysis patients with atrial fibrillation.

Femoral cam deformity due to anterior capsular force: A theoretical model with MRI and cadaveric correlation.

BACKGROUND: Cam deformity is associated with epiphyseal extension onto the anterosuperior femoral head-neck before physeal closure. A century ago, anatomists speculated that this femoral prominence acts as a pulley bar to withstand capsular compression in hip extension with pressure concentrated where the zona orbicularis (ZO) joins the iliofemoral ligament (IFL). An animal model has shown that growth plates deflect laterally and distally when exposed to forces perpendicular to growth. These observations raise the question of whether capsular pressure against the epiphysis can stimulate cam formation. PURPOSE: The purposes are to measure: (1) the distance from the ZO/IFL confluence to the maximal epiphyseal extension (MEE) and cam apex; and (2) acetabular depth at this location, since less coverage increases capsular contact on the physis. METHODS: MRI scans of 39 subjects (47 hips) were measured. Acetabular depth was compared between those with and without a cam deformity. Secondarily, anatomic findings were correlated on a cadaveric specimen. RESULTS: The cam apex and MEE were adjacent to the ZO/IFL confluence in all subjects (mean, 6.3 mm). Controlling for sex, acetabular depth was less (12.5%, p = 0.012) in the group with cam deformity. Contact points were confirmed in the specimen. CONCLUSIONS: The cam apex and MEE occur at the ZO/IFL confluence in the thickest region of the anterosuperior capsule and vary with acetabular depth. This supports a theoretical model postulating that capsular forces against an immature epiphysis may induce cam formation, particularly in individuals who repetitively tension the anterior capsule.

Atrial Fibrillation and Atrial Flutter in Pregnant Women-A Population-Based Study.

BACKGROUND: The goal of this study was to determine the prevalence of atrial fibrillation and atrial flutter (AF) in pregnant women and to examine the impact of AF on maternal and fetal outcomes. METHODS AND RESULTS: Between January 1, 2003 and December 31, 2013, there were 264 730 qualifying pregnancies (in 210 356 women) in the Kaiser Permanente Southern California hospitals, among whom AF was noted in 157 pregnancies (129 women; 61.3 per 100 000 women, or 59.3 per 100 000 pregnancies). Prevalence of AF (per 100 000 women) in white, black, Asian, and Hispanic women was 111.6, 101.7, 45.0, and 34.3, respectively. Older age was associated with higher odds of having AF. Compared to women <25 years of age, the odds ratio (OR) of AF was 4.1 in women age 30 to 34 years, 4.9 in women age 35 to 39 years, and 5.2 in women age ≥40. Odds of AF episodes were higher during the third trimester compared to the first trimester (OR, 3.2; 95% CI: 1.5-7.7). Among AF patients, adverse maternal cardiac events were rare-2 women developed heart failure and there were no strokes or systemic embolic events and no maternal death. There were 156 live births (99.4% of all pregnancies). Compared to women without AF, fetal birth weights were similar, but rate for neonates' admission to the neonatal intensive care unit was higher (10.8% vs 5.1%; P=0.003). CONCLUSIONS: AF is rare in pregnant women. Certain factors such as increased maternal age and white race increase the odds of having AF. Major maternal and fetal complications are infrequent, albeit a source of concern.

Abnormal rib count in scoliosis surgery: impact on the reporting of spinal fusion levels.

PURPOSE: Variation in rib numbering has been noted in adolescent idiopathic scoliosis (AIS), but its effect on the reporting of fusion levels has not been studied. We hypothesized that vertebral numbering variations can lead to differing documentation of fusion levels. METHODS: We examined the radiographs of 161 surgical AIS patients and 179 control patients without scoliosis. For AIS patients, the operative report of fusion levels was compared to conventional vertebral labeling from the first thoracic level and proceeding caudal. We defined normal counts as 12 thoracic (rib-bearing) and five lumbar (non-rib-bearing) vertebrae. We compared our counts with data from 181 anatomic specimens. RESULTS: Among AIS patients, 22 (14 %) had an abnormal number of ribs and 29 (18 %) had either abnormal rib or lumbar count. In 12/29 (41 %) patients, the operative report differed from conventional labeling by one level, versus 3/132 (2 %) patients with normal numbering (p < 0.001). However, there were no cases seen of wrong fusion levels based on curve pattern. Among controls, 11 % had abnormal rib count (p = 0.41) compared to the rate in AIS. Anatomic specimen data did not differ in abnormal rib count (p = 1.0) or thoracolumbar pattern (p = 0.59). CONCLUSIONS: The rate of numerical variations in the thoracolumbar vertebrae of AIS patients is equivalent to that in the general population. When variations in rib count are present, differences in numbering levels can occur. In the treatment of scoliosis, no wrong fusion levels were noted. However, for both scoliosis patients and the general population, we suggest adherence to conventional labeling to enhance clarity.

Gain in spinal height from surgical correction of idiopathic scoliosis.

BACKGROUND: A relationship between spinal distraction and correction of the curvature of scoliosis has long been recognized. While attempts have been made to define the height that is lost with progression of scoliosis, much less information is available to define the height that is gained as a result of surgical correction of the curve and to quantify additional spinal growth after spine fusion. METHODS: The present study included 116 patients (mean age, 14.8 years) who underwent spinal instrumentation and fusion for the treatment of idiopathic scoliosis. The study group included ninety-one female patients and twenty-five male patients; all Lenke curve types were represented. The Cobb angle and the T1-L5 spinal height were evaluated on preoperative, postoperative, and two-year follow-up radiographs. Kyphosis, lordosis, and T1-L5 spinal length were measured on lateral radiographs. The Scoliosis Research Society (SRS) questionnaire was completed prior to surgery and at each visit. Multivariate linear regression defined the relationship between spinal height gain, Cobb angle correction, and other variables as well as final spinal height. RESULTS: The mean spinal height gain due to surgery was 27.1 mm (median, 25.1 mm; interquartile range, 14.5 to 37.9 mm; range, -3.8 to 66.1 mm). The magnitude of curve correction (mean, 38.2°; range, 6° to 67°), the number of vertebral levels fused (mean, 9.9; range, three to sixteen), and the preoperative stature (standing height) of the patient were all significant predictors (p < 0.01) of spinal height gain (R2 = 0.8508 for multivariate model). The mean changes in kyphosis and lordosis were small and were not significant predictors. An additional 4.6 mm of mean spinal height was gained at the time of the two-year follow-up; this increase was significantly related to young age, male sex, shorter fusions, and a Risser stage of ≤2 at the time of surgery (p < 0.01 for all in multivariate analysis). The SRS-30 scores improved significantly (p < 0.0001), independent of spinal height gain. CONCLUSIONS: Patients undergoing surgical correction of idiopathic scoliosis gain substantial height related to the magnitude of surgical correction, the number of levels fused, and preoperative stature. Continued spine growth by two years after surgery is associated with shorter fusions, skeletal immaturity, young age, and male sex. Height gain is a quantifiable outcome of the surgical correction of scoliosis.

Biomechanical testing of pin configurations in supracondylar humeral fractures: the effect of medial column comminution.

OBJECTIVES: We measured biomechanical stability in simulated supracondylar humeral fractures fixed with each of 6 pin configurations, 2 with associated medial comminution, and developed a technique for reproducible pin placement and divergence. METHODS: A transverse supracondylar osteotomy was performed on 36 biomechanical humerus models. Of these, 24 (4 groups of 6 specimens each) were fixed with pins in 1 of 4 lateral entry configurations. The remaining 12 (2 groups of 6 specimens each) had a 30-degree medial wedge removed from the distal humerus and were fixed with 1 of 2 configurations. Half of each group was tested under axial rotation and the other half under varus bending. The distal humerus was divided into 4 equal regions from lateral to medial (1-4). Lateral entry pins were inserted through regions 1-3, whereas the medial pin was inserted through region 4. RESULTS: Without comminution, 3 widely spaced, divergent lateral entry pins resulted in higher torsional stiffness (0.36 Nm/degree) than 2 pins in adjacent regions (P < 0.055), but similar to 2 pins in nonadjacent regions (P = 0.57). Three lateral entry pins had higher bending stiffness (79.6 N/mm) than 2 pins, which ranged from 46.7 N/mm (P < 0.01) to 62.5 N/mm (P = 0.21). With comminution, adding a third medial entry pin increased torsional stiffness (0.13-0.24 Nm/degree, P < 0.01) and increased bending stiffness (38.7-44.7 N/mm, P = 0.10). CONCLUSIONS: For fractures without medial column comminution, fixation using 3 lateral entry pins may provide the greatest combination of torsional and bending stiffness. With medial comminution, adding a third medial pin increased torsional stiffness (P < 0.01) and bending stiffness (P = 0.10).

Intraoperative anaphylaxis to gelatin in topical hemostatic agents during anterior spinal fusion: a case report.

BACKGROUND CONTEXT: The use of topical hemostatic agents is widespread and has been shown to reduce bleeding during a wide variety of surgical procedures. Nonetheless, as biologically active agents, there is potential for allergic reactions to these products. PURPOSE: This is a report of intraoperative anaphylaxis to gelatin associated with the use of two topical hemostatic agents. STUDY DESIGN: Case report. There is no outside funding or potential conflict of interest. PATIENT SAMPLE: A patient with anaphylaxis during anterior spinal fusion. OUTCOME MEASURES: Laboratory assays for tryptase, gelatin-specific immunoglobulin E (IgE), and total IgE. METHODS: A 14-year-old male with myelomeningocele and scoliosis was treated with anterior spinal fusion from T12 to L3. Gelfoam sponges were applied during the preparation of the disc spaces. Approximately 1 hour later, Floseal hemostatic matrix was applied to a briskly bleeding screw hole in the L3 vertebral body, and the patient experienced an abrupt onset of hypotension and ventilatory difficulty. Epinephrine, dexamethasone, and blood products were administered for hemodynamic support while the surgical site was closed. Removal of the drapes revealed a widespread erythematous rash, and the patient was then transferred to the intensive care unit. When stable 3 days later, he returned to the operating room for completion of the spinal fusion. RESULTS: Postoperative laboratory assays were sent that revealed elevated levels of tryptase, total IgE, porcine, and bovine gelatin-specific IgE. The patient was counseled to avoid gelatin-containing products. At 6-month follow-up, his instrumented spine was radiographically fused and he reported no further allergic issues. CONCLUSIONS: Anaphylaxis may occur because of animal gelatin components of topical hemostatic agents. Previous reports have focused on the thrombin components. Care should be taken in the administration of these products, particularly in the atopic individual.