A Genetic Test Predicts Providence Brace Success for Adolescent Idiopathic Scoliosis When Failure Is Defined as Progression to >45 Degrees.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To determine whether a genetic test is associated with successful Providence bracing for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Genetic factors have been defined that predict the risk of progression of AIS in a polygenic fashion. From these data, a commercially available genetic test, ScoliScore, was developed. It is now used in clinical practice for counseling and to guide clinical management. Bracing is a mainstay of treatment for AIS. Large efforts have been made recently to reduce potential confounding across studies of different braces; however, none of these have considered genetics as a potential confounder. In particular, ScoliScore has not been evaluated in a population undergoing bracing. METHODS: We conducted a retrospective cohort study in which we identified a population of AIS patients who were initiated with Providence bracing and followed over time. Although these patients did not necessarily fit the commercial indications for ScoliScore, we contacted the patients and obtained a saliva sample from each for genetic analysis. We then tested whether ScoliScore correlated with the outcome of their bracing therapy. RESULTS: We were able to contact and invite 25 eligible subjects, of whom 16 (64.0%) returned samples for laboratory analysis. Patients were followed for an average of 2.3 years (range, 1.1-4 y) after initiation of the Providence brace. Eight patients (50.0%) progressed to >45 degrees, whereas the other 8 patients (50.0%) did not. The mean ScoliScore among those who progressed to >45 degrees was higher than that among those who did not (176 vs. 112, P=0.030). CONCLUSIONS: We demonstrate that a genetic test correlates with bracing outcome. It may be appropriate for future bracing studies to include analysis of genetic predisposition to limit potential confounding.

Patient compliance with postoperative lower extremity touch-down weight-bearing orders at a level I academic trauma center.

After lower extremity fracture or surgery, physicians often prescribe limited weight bearing. The current study was performed to evaluate teaching and compliance of touch-down weight bearing (defined as 25 lb) at a level I academic trauma center. A survey was distributed to physical therapists (PTs) from the orthopedic ward to gauge their training methods and their confidence in patients' ability to comply. Patients with recommended touch-down weight bearing were then evaluated on the day of discharge and again at their first follow-up appointment using the SmartStep weight-bearing measurement device (Andante Medical Devices, Inc, White Plains, New York). Fifteen PTs completed the survey (average of 14 years in practice). Inconsistency was observed in weight-bearing teaching methods: verbal cues were used 87% of the time, tactile methods were used 41%, demonstration was used 23%, and a scale was used only 1%. Limited confidence was found in the instruction efficacy by those surveyed. Twenty-one patients were seen the day of discharge and 18 of those were seen at first follow-up. At discharge, average minimum and maximum weight bearing were 3.2 and 30.2 lb, respectively. Only 31% of steps were within an acceptable range of 15 to 35 lb. At first follow-up, average minimum and maximum weight bearing were 12.2 and 50.8 lb, respectively. Only 27% of steps were within the acceptable range. The majority of steps were less than the prescribed weight at discharge, whereas the majority of steps were greater than the prescribed weight at first follow-up. These data suggest that more uniform and effective teaching methods for prescribed weight-bearing orders are warranted assuming compliance is an important clinical objective.

Oswestry Disability Index is a better indicator of lumbar motion than the Visual Analogue Scale.

BACKGROUND CONTEXT: Lumbar pathology is often associated with axial pain or neurologic complaints. It is often presumed that such pain is associated with decreased lumbar motion; however, this correlation is not well established. The utility of various outcome measures that are used in both research and clinical practice have been studied, but the connection with range of motion (ROM) has not been well documented. PURPOSE: The current study was performed to assess objectively the postulated correlation of lumbar complaints (based on standardized outcome measures) with extremes of lumbar ROM and functional ROM (fROM) with activities of daily living (ADLs) as assessed with an electrogoniometer. STUDY DESIGN/SETTING: This study was a clinical cohort study. PATIENT SAMPLE: Subjects slated to undergo a lumbar intervention (injection, decompression, and/or fusion) were enrolled voluntarily in the study. OUTCOME MEASURES: The two outcome measures used in the study were the Visual Analogue Scale (VAS) for axial extremity, lower extremity, and combined axial and lower extremity, as well as the Oswestry Disability Index (ODI). METHODS: Pain and disability scores were assessed with the VAS score and ODI. A previously validated electrogoniometer was used to measure ROM (extremes of motion in three planes) and fROM (functional motion during 15 simulated activities of daily living). Pain and disability scores were analyzed for statistically significant association with the motion assessments using linear regression analyses. RESULTS: Twenty-eight men and 39 women were enrolled, with an average age of 55.6 years (range, 18-79 years). The ODI and VAS were associated positively (p<.001). Combined axial and lower extremity VAS scores were associated with lateral and rotational ROM (p<.05), but not with flexion/extension or any fROM. Similar findings were noted for separately analyzed axial and lower extremity VAS scores. On the other hand, the ODI correlated inversely with ROM in all planes, and fROM in at least one plane for 10 of 15 ADLs (p<.05). CONCLUSIONS: Extremes of lumbar motion and motions associated with ADLs are of increasing clinical interest. Although the ODI and VAS are associated with each other, the ODI appears to be a better predictor of these motion parameters than the VAS (axial extremity, lower extremity, or combined) and may be more useful in the clinical setting when considering functional movement parameters.

Recovery room radiographs not found to have incremental utility above intraoperative images after lumbar fusion procedures.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To characterize the clinical utility of imaging in the recovery room after lumbar fusion procedures. SUMMARY OF BACKGROUND DATA: Two sets of images are commonly obtained at the end of lumbar fusion procedures: intraoperative fluoroscopic images near the time of wound closure and plain film images after the procedure in the recovery room. The latter may have low clinical utility. METHODS: We identified a consecutive series of lumbar fusion procedures. A panel of 3 reviewers assessed intraoperative and recovery room series both for radiographical adequacy and for issues with the surgical construct. RESULTS: One hundred ninety cases were reviewed, of which 92 were posterolateral lumbar fusions, 42 were anterior lumbar interbody fusions, 24 were transforaminal lumbar interbody fusions, and 32 were anterior-posterior fusions. All intraoperative series were adequate, whereas only 90% of recovery room series were adequate. Recovery room series had visible issues with construct placement in 4 cases. In each of these cases, however, the issue was also clearly visible on the intraoperative series, was found to be acceptable clinically, and did not alter management in any way. CONCLUSION: This study demonstrates that recovery room images are inferior to intraoperative images and offer little or no incremental clinical utility for detecting issues with surgical constructs after lumbar fusion procedures. In settings where it is still performed, recovery room imaging might be discontinued to realize savings in cost, radiation exposure, and time. LEVEL OF EVIDENCE: 4.

Routine imaging for elective lumbar spine surgery: a questionnaire study.

STUDY DESIGN: Cross-sectional, questionnaire study. OBJECTIVE: To characterize imaging practices for 3 common lumbar spine procedures. SUMMARY OF BACKGROUND DATA: As lumbar surgical procedures are performed with increasing frequency, it becomes incrementally more important to optimize patient care, minimize risk, and reduce associated costs. Imaging is an area for potential improvement; however, little has been done to characterize current imaging practices, compare imaging practices with current evidence, or establish a standard of care. METHODS: We distributed a single-page questionnaire to all attending spine surgeons at a United States spine conference (The Spine Study Group) in 2012. RESULTS: Forty-one of 74 surgeons (55.4%) completed and returned the questionnaire. All results are given for posterior lumbar decompression, posterior lumbar fusion, and anterior lumbar fusion, respectively.Intraoperatively, 75%, 90%, and 95% of surgeons use fluoroscopy, whereas 25%, 10%, and 5% use plain film; 80%, 59%, and 54% take images prior to skin incision; 59%, 98%, and 100% always take final images at the end of the procedure while still in the operating room. Postoperatively, 13%, 54%, and 54% of surgeons take images after patients have left the operating room but before they have been discharged. Interestingly, 10%, 50%, and 51% of surgeons not only take intraoperative images of their final constructs, but also take additional images before discharge.Surgeons follow their postoperative outpatients with imaging for a mean of 0.4, 1.5, and 1.5 years. Fifty-four percent, 98%, and 100% follow with anterior-posterior views; 56%, 93%, and 95% with lateral views; and 15%, 39%, and 39% with flexion-extension films. For both anterior and posterior fusion, 26% routinely follow with computed tomographic scan to assess fusion. CONCLUSION: Findings highlight extreme variability in practice associated with a notable lack of standard of care and provide a baseline for utility studies that may lead to more evidence-driven care.

Balancing with vibration: a prelude for "drift and act" balance control.

Stick balancing at the fingertip is a powerful paradigm for the study of the control of human balance. Here we show that the mean stick balancing time is increased by about two-fold when a subject stands on a vibrating platform that produces vertical vibrations at the fingertip (0.001 m, 15-50 Hz). High speed motion capture measurements in three dimensions demonstrate that vibration does not shorten the neural latency for stick balancing or change the distribution of the changes in speed made by the fingertip during stick balancing, but does decrease the amplitude of the fluctuations in the relative positions of the fingertip and the tip of the stick in the horizontal plane, A(x,y). The findings are interpreted in terms of a time-delayed "drift and act" control mechanism in which controlling movements are made only when controlled variables exceed a threshold, i.e. the stick survival time measures the time to cross a threshold. The amplitude of the oscillations produced by this mechanism can be decreased by parametric excitation. It is shown that a plot of the logarithm of the vibration-induced increase in stick balancing skill, a measure of the mean first passage time, versus the standard deviation of the A(x,y) fluctuations, a measure of the distance to the threshold, is linear as expected for the times to cross a threshold in a stochastic dynamical system. These observations suggest that the balanced state represents a complex time-dependent state which is situated in a basin of attraction that is of the same order of size. The fact that vibration amplitude can benefit balance control raises the possibility of minimizing risk of falling through appropriate changes in the design of footwear and roughness of the walking surfaces.