Surgical treatment of Lenke 5 adolescent idiopathic scoliosis: Comparison of anterior vs posterior approach.

AIM: To compare the posterior vs anterior approaches for fusion of Lenke 5 adolescent idiopathic scoliosis curves, matched for curve magnitude and for the distal level of fixation (dLOF) standardized to the third lumbar vertebrae (L3). METHODS: A prospectively collected multicenter database was used for this retrospective comparative study. Our dependent variables included sagittal and coronal radiographic measurements, number of fused vertebrae, estimated blood loss, length of hospitalization and SRS total and individual domain scores at the two-year follow-up. Subject demographics were similar for all group comparisons. Independent t-test was used to compare groups for all analyses at P < 0.01. RESULTS: For all matched cases of Lenke 5 curves, a selective approach was used only 50% of the time in cases undergoing a posterior fusion. When comparing a posterior selective approach to an anterior selective approach, surgeons utilizing a posterior approach fused significantly more levels than surgeons using an anterior approach with no other significant differences in radiographic or SRS outcomes (Ant = 4.8 ± 1.0 levels vs post = 6.1 ± 1.0 levels, P < 0.0001). When the dLOF was standardized to L3, the anterior approached provided significantly greater lumbar Cobb percent correction than the posterior approach (Ant = 69.1% ± 12.6% vs post = 54.6% ± 16.4%, P = 0.004), with no other significant radiographic or SRS score differences between approaches. CONCLUSION: Surgeons treating Lenke 5c curves with a posterior instrumentation and fusion vs an anterior approach include more motion segments, even with a selective fusion. When controlled for the distal level of fixation, the anterior approach provides greater correction of the thoracolumbar curve.

Comparative effects of multilevel muscle tendon surgery, osteotomies, and dorsal rhizotomy on functional and gait outcome measures for children with cerebral palsy.

OBJECTIVE: To compare the impact of common surgical interventions (selective dorsal rhizotomy, muscle-tendon surgery, and osteotomies) for patients with cerebral palsy (CP) on Gross Motor Function Measure and temporal, kinematic, and kinetic gait variables as assessed via 3-dimensional motion analysis. DESIGN: Retrospective cohort study. SETTING: Motion analyses laboratory. PARTICIPANTS: Ninety-four patients with CP, 56 of whom underwent surgery (37, muscle-tendon surgery; 11, osteotomy; and 8, selective dorsal rhizotomy) and 38 of whom did not have surgery; the patients were ages 4-18 years, with a Gross Motor Function Classification System classification of I, II, or III. INTERVENTIONS: Single-event, multilevel muscle tendon surgery, selective dorsal rhizotomy, and osteotomy. MAIN OUTCOME MEASURES: Change scores (postintervention - preintervention) in Gross Motor Function Measure and temporal, kinematic, and kinetic gait variables. RESULTS: No statistically significant differences in change scores were found between groups in the Gross Motor Function Measure, velocity, or stride length measures after the observation period. The selective dorsal rhizotomy group had greater improvements in knee extension when compared with the nonsurgical group and greater hip and knee total range of motion during the gait cycle when compared with nonsurgical group and the muscle-tendon surgery and osteotomy cohorts. Lastly, the muscle-tendon surgery group had greater improvements in total knee range of motion compared with the nonsurgical group. CONCLUSIONS: Patients who undergo selective dorsal rhizotomy and, to a lesser extent, muscle tendon procedures demonstrate greater improvements in kinematic gait variables compared with nonsurgical interventions in patients with spasticity resulting from CP.

Manual therapy directed at the knee or lumbopelvic region does not influence quadriceps spinal reflex excitability.

UNLABELLED: Manual therapies, directed to the knee and lumbopelvic region, have demonstrated the ability to improve neuromuscular quadriceps function in individuals with knee pathology. It remains unknown if manual therapies may alter impaired spinal reflex excitability, thus identifying a potential mechanism in which manual therapy may improve neuromuscular function following knee injury. AIM: To determine the effect of local and distant mobilisation/manipulation interventions on quadriceps spinal reflex excitability. METHODS: Seventy-five individuals with a history of knee joint injury and current quadriceps inhibition volunteered for this study. Participants were randomised to one of five intervention groups: lumbopelvic manipulation (grade V), lumbopelvic manipulation positioning (no thrust), grade IV patellar mobilisation, grade I patellar mobilisation, and control (no treatment). Changes in spinal reflex excitability were quantified by assessing the Hoffmann reflex (H-reflex), presynaptic, and postsynaptic excitability. A hierarchical linear-mixed model for repeated measures was performed to compare changes in outcome variables between groups over time (pre, post 0, 30, 60, 90 min). RESULTS: There were no significant differences in H-reflex, presynaptic, or postsynaptic excitability between groups across time. CONCLUSIONS: Manual therapies directed to the knee or lumbopelvic region did not acutely change quadriceps spinal reflex excitability. Although manual therapies may improve impairments and functional outcomes the underlying mechanism does not appear to be related to changes in spinal reflex excitability.

Sagittal plane kinematics during the transition run in triathletes.

OBJECTIVES: Epidemiological evidence indicates more than 70% of all injuries that occur while training for or competing in triathlon happen during running. Maintaining an aerodynamic position on a bicycle during a triathlon places triathletes in a prolonged trunk flexed position which may affect lower extremity running biomechanics following cycling and influence both injury risk and performance in these athletes. The aim of this study was to compare sagittal plane running kinematics after a 30-min cycling protocol to a baseline run without prior exercise. DESIGN: Descriptive laboratory study. METHODS: Healthy participants with prior triathlon experience (n=28; height=1.73±0.09m; mass=63.0±7.7kg; age=24.6±5.8years) ran at a self-selected speed on a custom-built treadmill surrounded by a 12-camera motion analysis system before and after a 30-min cycling protocol (RPE 12-14). Three-dimensional kinematics were measured before, and at 2-min, 6-min, 10-min, and 14-min post-cycling. A 1×5 series of repeated measures univariate ANOVAs were used to determine changes in kinematic parameters resulting from the cycling protocol. Statistical significance was set a priori at (p<0.05). RESULTS: Peak angles for anterior pelvic tilt (p<0.001), hip flexion (p<0.001), and spine extension (p<0.001) increased and hip extension decreased (p<0.001) at all time points while running following cycling compared to baseline. CONCLUSIONS: Cycling in an aerodynamic position for 30min induces changes in sagittal plane running kinematics of the spine, pelvis, and hip for at least 14min following cycling. Alterations in kinematics may increase the risk for lower extremity injuries and affect running performance in triathletes.

Effects of a proximal or distal tibiofibular joint manipulation on ankle range of motion and functional outcomes in individuals with chronic ankle instability.

STUDY DESIGN: Randomized clinical trial. OBJECTIVES: To determine whether manipulation of the proximal or distal tibiofibular joint would change ankle dorsiflexion range of motion and functional outcomes over a 3-week period in individuals with chronic ankle instability. BACKGROUND: Altered joint arthrokinematics may play a role in chronic ankle instability dysfunction. Joint mobilization or manipulation may offer the ability to restore normal joint arthrokinematics and improve function. METHODS: Forty-three participants (mean ± SD age, 25.6 ± 7.6 years; height, 174.3 ± 10.2 cm; mass, 74.6 ± 16.7 kg) with chronic ankle instability were randomized to proximal tibiofibular joint manipulation, distal tibiofibular joint manipulation, or a control group. Outcome measures included ankle dorsiflexion range of motion, the single-limb stance on foam component of the Balance Error Scoring System, the step-down test, and the Foot and Ankle Ability Measure sports subscale. Measurements were obtained prior to the intervention (before day 1) and following the intervention (on days 1, 7, 14, and 21). RESULTS: There was no significant change in dorsiflexion between groups across time. When groups were pooled, there was a significant increase (P<.001) in dorsiflexion at each postintervention time interval. No differences were found among the Balance Error Scoring System foam, step-down test, and Foot and Ankle Ability Measure sports subscale scores. CONCLUSIONS: The use of a proximal or distal tibiofibular joint manipulation in isolation did not enhance outcome effects beyond those of the control group. Collectively, all groups demonstrated increases in ankle dorsiflexion range of motion over the 3-week intervention period. These increases might have been due to practice effects associated with repeated testing. LEVEL OF EVIDENCE: Therapy, level 2b-.

A gender comparison of central and peripheral neuromuscular function after exercise.

CONTEXT: Central and peripheral muscle fatigue during exercise may exacerbate neuromuscular factors that increase risk for noncontact anterior cruciate ligament injury. OBJECTIVE: To compare lower extremity motor-evoked potentials (MEPs), muscle strength, and electromyography (EMG) activation after an exercise protocol. DESIGN: Pretest, posttest group comparison. SETTING: University laboratory. PARTICIPANTS: 34 healthy volunteers (17 female, age = 21.9 ± 2.3 years, weight = 77.8 ± 3.0 kg, height = 171.1 ± 6.6 cm, and 17 male, age = 23.4 ± 6.5 years, weight = 81.6 ± 3.3 kg, height = 179.6 ± 7.3 cm). INTERVENTION: A standardized 30-min exercise protocol that involved 5 repeated cycles of uphill walking, body-weight squatting, and step-ups. MAIN OUTCOME MEASURES: Quadriceps and hamstring MEP amplitude (mV) and transmission velocity normalized to subject height (m/s) were elicited via transcranial magnetic stimulation and measured via surface EMG. Quadriceps and hamstring peak EMG activation (% MVIC) and peak torque (Nm/kg) were measured during MVICs. Separate ANCOVAs were used to compare groups after exercise while controlling for baseline measurement. RESULTS: At baseline, males exhibited significantly greater knee-extension torques (males = 2.47 ± 0.68 Nm/kg, females = 1.95 ± 0.53 Nm/kg; P = .036) and significantly higher hamstring MEP amplitudes (males = 223.5 ± 134.0 mV, females = 89.3 ± 77.6 mV; P = .007). Males exhibited greater quadriceps MEP amplitude after exercise than females (males = 127.2 ± 112.7 mV, females = 32.3 ± 34.9 mV; P = .016). CONCLUSIONS: Males experienced greater peripheral neuromuscular changes manifested as more pronounced reductions in quadriceps torque after exercise. Females experienced greater central neuromuscular changes manifested as more pronounced reduction in quadriceps MEP amplitude. Reduced central neural drive of the quadriceps coupled with knee-extension torque preservation after exercise may increase risk of knee injury in females.

Immediate effects of a tibiofibular joint manipulation on lower extremity H-reflex measurements in individuals with chronic ankle instability.

Persistent muscle inhibition of the fibularis longus and soleus muscles and altered joint arthrokinematics may play a role in chronic ankle instability (CAI). Joint mobilization has been shown to improve ankle joint motion, but effects on surrounding musculature is unknown. The purpose of this study was to determine the change in fibularis longus and soleus activation following tibiofibular joint manipulation in individuals with CAI. Forty-three subjects were randomized to one of three groups (proximal tibiofibular manipulation, distal tibiofibular manipulation, or control). A two-way mixed model ANOVA was used to compare changes in the ratio of the maximum H-reflex and maximum M-wave measurements (H/M ratio) of the fibularis longus and soleus between groups over time (pre, post 0, 10, 20, 30 min). The distal tibiofibular joint manipulation group demonstrated a significant increase (P<.05) in soleus H/M ratio at all post-intervention time periods except 20 min post-intervention (P=.48). The proximal tibiofibular joint manipulation and control groups did not demonstrate a change in soleus H/M ratios. All groups demonstrated a decrease (P<.05) from baseline values in fibularis longus (10-30 min post-intervention) and soleus (30 min post-intervention) H/M ratios. Interventions directed at the distal tibiofibular joint acutely increase soleus muscle activation.

Selective versus nonselective fusion for idiopathic scoliosis: does lumbosacral takeoff angle change?

STUDY DESIGN: Retrospective review of a prospective, multicentered database. OBJECTIVE: To determine the relationship between preoperative lumbosacral takeoff angle (LSTOA) and postoperative thoracolumbar/lumbar Cobb angle (TL/L Cobb angle) in patients undergoing selective thoracic fusions SUMMARY OF BACKGROUND DATA: Selective fusion of the thoracic curve can improve the lumbar curve inpatients with idiopathic thoracic scoliosis and a compensatory lumbar curve. Predicting improvement is controversial and determining whether to perform a selective fusion or nonselective fusion can be difficult. METHODS: Patients had undergone either nonselective or selective spinal fusion for adolescent or juvenile idiopathic scoliosis (Lenke 1B/3B/1C/3C). Outcome measures were: coronal and sagittal thoracic Cobb angle, TL/L Cobb angles, lumbar apical vertebral translation, LSTOA and coronal decompensation. Analyses compared relationships between preoperative and postoperative radiographic measures. RESULTS: Positive, significant correlations were found between preoperative LSTOA and preoperative TL/L Cobb angle in the nonselective (r=0.7; P<0.001) and selective (r=0.5; P<0.001) fusion groups. Mean two-year postoperative coronal TL/L Cobb angles were significantly improved in nonselective and selective fusion groups (32° and 20°, respectively, P<0.001). In the nonselective fusion group, LSTOA significantly decreased by 11° (P<0.001), and in the selective group, the LSTOA had a modest but significant decrease of 2° (P<0.001). The nonselective fusion also resulted in more lordosis between T10 and L2 (7.5° of lordosis) than the selective approach (2.7° kyphosis, P<0.001). For both groups, upper thoracic kyphosis increased after surgery (P<0.001, P<0.001). For nonselective fusions, regression modeling predicted TL/L Cobb angle at two-year follow-up based on preoperative TL/L Cobb angle and preoperative LSTOA (r=0.4, P<0.001). CONCLUSION: Collectively, these data demonstrate the preoperative TL/L Cobb angle and LSTOA can be useful predictors of postoperative TL/L Cobb angle after a selective instrumented fusion. Analyses of distal fixation levels demonstrated that to appreciably change the LSTOA using a posterior instrumented fusion, the distal level of fixation must be beyond the lumbar apex.

Increased in-shoe lateral plantar pressures with chronic ankle instability.

BACKGROUND: Previous plantar pressure research found increased loads and slower loading response on the lateral aspect of the foot during gait with chronic ankle instability compared to healthy controls. The studies had subjects walking barefoot over a pressure mat and results have not been confirmed with an in-shoe plantar pressure system. Our purpose was to report in-shoe plantar pressure measures for chronic ankle instability subjects compared to healthy controls. METHODS: Forty-nine subjects volunteered (25 healthy controls, 24 chronic ankle instability) for this case-control study. Subjects jogged continuously on a treadmill at 2.68 m/s (6.0 mph) while three trials of ten consecutive steps were recorded. Peak pressure, time-to-peak pressure, pressure-time integral, maximum force, time-to-maximum force, and force-time integral were assessed in nine regions of the foot with the Pedar-x in-shoe plantar pressure system (Novel, Munich, Germany). RESULTS: Chronic ankle instability subjects demonstrated a slower loading response in the lateral rearfoot indicated by a longer time-to-peak pressure (16.5% +/- 10.1, p = 0.001) and time-to-maximum force (16.8% +/- 11.3, p = 0.001) compared to controls (6.5% +/- 3.7 and 6.6% +/- 5.5, respectively). In the lateral midfoot, ankle instability subjects demonstrated significantly greater maximum force (318.8 N +/- 174.5, p = 0.008) and peak pressure (211.4 kPa +/- 57.7, p = 0.008) compared to controls (191.6 N +/- 74.5 and 161.3 kPa +/- 54.7). Additionally, ankle instability subjects demonstrated significantly higher force-time integral (44.1 N/s +/- 27.3, p = 0.005) and pressure-time integral (35.0 kPa/s +/- 12.0, p = 0.005) compared to controls (23.3 N/s +/- 10.9 and 24.5 kPa/s +/- 9.5). In the lateral forefoot, ankle instability subjects demonstrated significantly greater maximum force (239.9N +/- 81.2, p = 0.004), force-time integral (37.0 N/s +/- 14.9, p = 0.003), and time-to-peak pressure (51.1% +/- 10.9, p = 0.007) compared to controls (170.6 N +/- 49.3, 24.3 N/s +/- 7.2 and 43.8% +/- 4.3). CONCLUSION: Using an in-shoe plantar pressure system, chronic ankle instability subjects had greater plantar pressures and forces in the lateral foot compared to controls during jogging. CLINICAL RELEVANCE: These findings may have implications in the etiology and treatment of chronic ankle instability.