Jean-Luc Jouve

Reciprocal sagittal alignment changes after posterior fusion in the setting of adolescent idiopathic scoliosis

PurposeSurgical adolescent idiopathic scoliosis (AIS) management can be associated with loss of thoracic kyphosis and a secondary loss of lumbar lordosis leading to iatrogenic flatback. Such conditions are associated with poorer clinical outcomes during adulthood. The aim of this study was to evaluate sagittal plane reciprocal changes after posterior spinal fusion in the setting of AIS.MethodsThirty consecutive adolescents (mean age 14.6xa0years) with AIS Lenke 1, 2 or 3 were included in this retrospective study with 2xa0year follow-up. Full-spine standing coronal and lateral radiographs were obtained preoperatively, at 3 and 24xa0months postoperatively. Coronal Cobb angle, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured. Surgical procedure was similar in all the cases, with use of pedicular screws between T11 and the lowest instrumented vertebra (≥L2), sublaminar hooks applied in compression at the upper thoracic level and sub-laminar bands and clamps in the concavity of the deformity. Statistical analysis was done using t test and Pearson correlation coefficient.ResultsBetween preoperative and last follow-up evaluations a significant reduction of Cobb angle was observed (53.6° vs. 17.2°, pxa0<xa00.001). A significant improvement of the instrumented thoracic kyphosis, TK (19.7° vs. 26.2°, pxa0<xa00.005) was noted, without difference between 3 and 24xa0months postoperatively. An improvement in lumbar lordosis, LL (43.9° vs. 47.3°, pxa0=xa00.009) was also noted but occurred after the third postoperative month. A significant correlation was found between TK correction and improvement of LL (Rxa0=xa00.382, pxa0=xa00.037), without correlation between these reciprocal changes and the amount of coronal correction.ConclusionResults from this study reveal that sagittal reciprocal changes occur after posterior fusion when TK is restored. These changes are visible after 3xa0months postoperatively, corresponding to a progressive adaptation of patient posture to the surgically induced alignment. These changes are not correlated with coronal plane correction of the deformity. In the setting of AIS, TK restoration is a critical goal and permits favorable postural adaptation. Further studies will include pelvic parameters and clinical scores in order to evaluate the impact of the noted reciprocal changes.

Dynamic equinus with hindfoot valgus in children with hemiplegia.

In children with hemiplegia, it is important to distinguish between equinus with hindfoot varus (equinovarus) or valgus (equinovalgus). Premature onset of medial gastrocnemius (GM) EMG in individuals with equinus is well documented. Premature onset of Peroneus longus (PL) EMG has been described in neurologically impaired adults with equinovalgus, but not in children. Our aim was to record the onset of PL and GM activity on the hemiplegic side of children with equinovalgus deformity. Fifteen children GMFCS 1 (3.8 yrs ± 2) with hemiplegia had a goniometric assessment of passive ankle range of motion and assessment of ankle function from video and surface EMG recording during gait. The clinical and video observations were used to determine the equinovalgus, as defined by Wren, at initial contact (IC). The premature onset of muscle activity was normalised as a swing (SW) percentage prior to IC of the following stance (ST). A paired T-test compared the onset of muscle activity between PL and GM. The ankle passive dorsiflexion was 13° ± 12° (hemiplegic side) versus 18° ± 10° (non-involved side) (p<0.05). For the non-involved limb, the onset of GM activity was at 14% of the gait cycle (midstance), the onset of PL activity was at 19% (p<0.05). For the hemiplegic limb with equinovalgus, there was a premature onset activity of PL (-24%) and GM(-8%) (p<0.001). On the non involved side, the onset of PL activity occurred, as in adults, after the onset of GM activity, during ST. On the hemiplegic side, there was no triceps surae contracture and the onset of PL activity occurred prior to the onset of GM activity, during terminal SW. This study confirmed the overactivity of PL in hemiplegic children with equinovalgus.

Role of thoracoscopy for the sagittal correction of hypokyphotic adolescent idiopathic scoliosis patients

PurposeThoracic adolescent idiopathic scoliosis (AIS) curves (Lenke 1–4) are often characterized by hypokyphosis. Sagittal alignment remains challenging to correct, even with recent posterior segmental instrumentation. Some authors recommend anterior endoscopic release (AER) to reduce anterior column height, and facilitate thoracic kyphosis correction. The aim of this study was to assess the contribution of AER to sagittal correction in hypokyphotic AIS.MethodsFifty-six hypokyphotic (T4T12<20°) AIS patients were included. In group 1 (28 patients), patients first underwent AER, followed by posterior instrumentation and correction 5–7xa0days later. In group 2 (28 patients), patients underwent the same posterior procedure without AER. Posterior correction was performed in all cases using posteromedial translation and hybrid constructs consisting of lumbar pedicle screws and thoracic sublaminar bands. From radiological measurements performed using low-dose EOS radiographs, the correction of thoracic kyphosis was compared between the two groups.ResultsGroups 1 and 2 were comparable regarding demographic data and preoperative thoracic kyphosis (group 1: 11.7°xa0±xa06.9° vs group 2: 12.1°xa0±xa06.3°, pxa0=xa00.89). Postoperative thoracic kyphosis increase averaged 18.3°xa0±xa013.6° in group 1 and 15.2°xa0±xa09.0° in group 2. The benefit of anterior release was not statistically significant (pxa0=xa00.35).ConclusionAlthough previous studies have suggested that thoracoscopic release improved correction compared to posterior surgery alone, the current study did not confirm this finding. Moreover, results of the current series showed that no significant benefit can be expected from AER in terms of sagittal plane improvement when the posteromedial translation technique is used, even in challenging hypokyphotic patients.

Sublaminar bands: are they safe?

AbstractBackgroundSublaminar bands (SB) are frequentlyn used as implants in spine deviation correction.PurposeOur purpose is to demonstrate their safety on a large series of patients.Study designThis is a retrospective study.MethodsOur department treated 378 spine deviations on children and adolescents via a hybrid posterior technique (lumbar screws, hook and thoracic SB). Each surgery was undertaken using anesthesiologic and a neurophysiologic monitoring using somatosensory evoked potentials (SSEP) and neurogenic mixed evoked potentials (NMEP). An alert was described as an amplitude decrease of 50xa0% and/or a latency increase of 10xa0%. Data were analyzed using Student or Wilcoxon tests.ResultsWe used 2,223 SB in 378 operative procedures. We described ten neurophysiologic alerts during the passage of the band under the lamina. There were no significative differences between the two groups concerning the age and the severity of the deformation (pxa0>xa00.05). These neurophysiologic alerts were associated with a dysautonomic trouble (hypertension and bradycardia). The lesional level was determined using a spinal electrode. In six cases, the responsible SB was removed. Three patients had post-operative neurologic deficiency (0.8xa0%) without complete recovery for one of them (localized incomplete sensitive deficiency). Within the group of 378 patients, 21 alerts were reported due to a screw or a hook, or during the correction manoeuver, without dysautonomic trouble.ConclusionSB neurologic complications rate is as high as other implants’ complication rate. Simultaneous hemodynamic and neurophysiologic change is an argument for vegetative response due to SB passage. Their optimal use requires a strict learning of their insertion under the lamina to be as less traumatic as possible. SB are as safe as any other spine implants.

Circumferential fusion using a custom-made screw in the management of high-grade spondylolisthesis

PurposeManagement of high-grade spondylolisthesis is challenging and to date no therapeutic consensus is available. Various surgical procedures have been described using unique or double approach. The aim of the study is to describe an original technique using a posterior-only approach to achieve a circumferential lumbosacral fusion with a custom-made screw.MethodsIn our experience, eight patients (mean age 15xa0years old) were treated for grade III or IV slipping without instrumental reduction. Surgical technique included a laminectomy from L5 to S2, then after mobilization of neural elements a guide wire was inserted from the posterior side of S2 to the antero-superior corner of L5. A specific drill was used and the 10-mm screw was then inserted under fluoroscopic guidance. Further steps included a discectomy, lumbosacral interbody graft and posterolateral graft to obtain a circumferential fusion. Clinical and radiological evaluations were obtained.ResultsOn the whole series, solid fusion was achieved after 6xa0months on average. Sagittal realignment was observed with a regression of pelvic retroversion and hip flessum, a lumbarization of the lumbar lordosis and an improvement of the thoracic kyphosis. For one patient, a postoperative S1 deficit was observed.ConclusionThis technique provides satisfactory results in the management of high-grade spondylolisthesis. This concept is based on a double spine instability considering viscoelastic properties of the disc and postoperative sagittal reciprocal changes as prerequisite. This posterior-only approach represents a valuable alternative to other procedures.

Intraoperative spinal cord monitoring in children under 4 years old

PurposeThe purpose was to study intraoperative spinal cord monitoring (IOM) particularities and performances in children under 4xa0years old with congenital spinal deformities. IOM is characterized by specific difficulties due to the immaturity of sensory-motor pathways in such young patients. To the best of our knowledge, this study is the largest dedicated to IOM in this challenging population.MethodsThis study was retrospective and monocentric. 78 IOM in children under 4xa0years old were analyzed. Somatosensory evoked potentials (SSEP), neurogenic mixed evoked potentials (NMEP) and D waves were performed. Patients were classified into one of four categories with respect to IOM data and clinical outcome: true positive, false positive, true negative and false negative. Sensitivity and specificity were then calculated accordingly.ResultsThere were 6 true positive, 3 false positive, 67 true negative and 1 false negative outcomes. One patient was characterized by unreliable baseline IOM data. IOM sensitivity was 86xa0%. IOM specificity was 96xa0%. The false negative case was monitored using SSEP alone. IOM was difficult in 10/77 cases, being unilateral because of a planned fibular graft harvest. NMEP were characterized by higher signal-to-noise ratio than SSEP.ConclusionsImmaturity of sensory-motor pathways predominates in the central rather than the peripheral nervous system in young children. MEP and D waves could thus be difficult to obtain. Although non-specific to motor pathways, it could be useful to “by-pass” the brain, using NMEP. In regard to maturational particularities, IOM in children under 4xa0years old should be performed by experienced neurophysiologists, avoiding in these cases surgeon-guided devices.

Planovalgus foot deformity in cerebral palsy corrected by botulinum toxin injection in the peroneus longus: Clinical and radiological evaluations in young children

BACKGROUNDnIn children with cerebral palsy (CP), overactivity of the peroneus longus (PL) muscle is a major contributor to pes planovalgus. This retrospective study assessed whether abobotulinumtoxinA injections into a PL showing premature activity on electromyography (EMG) clinically improved foot morphology in children with CP.nnnMETHODSnStudy participants were <6 years old, had a diagnosis of CP, good functional abilities (Gross Motor Function Classification System level 1 or 2), equinovalgus (initial contact with the hallux or head of the first metatarsal) and overactive PL on EMG. The fore-, mid- and hindfoot were evaluated clinically and radiologically before and after injection of abobotulinumtoxinA (6-7 U/kg) into the PL. Radiological data were compared with reference values for children without pes planovalgus.nnnRESULTSnIn total, 16 children (8 males; 10 hemiplegia, 6 diplegia; mean age: 3.2±1.5 years) received treatment. Mean pre-and post-treatment angles in clinical assessment of dorsiflexion of the talocrural articulation did not differ with both knees flexed (24.4±7.5 vs. 22.2±8.0 degrees; P=0.19) or extended (17.2±8.0 vs. 16.6±6.8 degrees; P=0.36). Radiographic data pre-treatment versus reference data revealed forefoot pronation (metatarsal stacking angle 2.1±8.3 vs. 8.0±2.9 degrees; P=0.002), midfoot planus (lateral talo-first metatarsal 28.5±15.0 vs. 13.0±7.5 degrees; P<0.001; talocalcaneal angle 54.6±8.6 vs. 49.0±6.9 degrees; P=0.004) and significantly decreased calcaneus dorsiflexion, without hindfoot equinus (calcaneal pitch angle 7.9±6.0 vs. 17.0±6.0 degrees; P<0.001). After treatment, the metatarsal stacking angle did not differ from reference values (P=0.15). As compared with before treatment, treatment improved mean angles for metatarsal stacking (2.1±8.3 vs. 7.1±3.9 degrees, respectively, P=0.002), lateral talo-first metatarsal and talocalcaneal (both P<0.001), with no change in the hindfoot.nnnCONCLUSIONnPL may be an early target for abobotulinumtoxinA treatment in pes planovalgus associated with premature PL activity in children with CP.

Correction of hypokyphosis in thoracic adolescent idiopathic scoliosis using sublaminar bands: a 3D multicenter study

IntroductionThe comparison of implants and correction methods remain controversial in AIS. Excellent frontal and axial correction rates have been reported with all-screw constructs, but at the expense of sagittal alignment, which has a tendency to flatten postoperatively. Posteromedial translation using hybrid constructs seems to preserve and improve thoracic kyphosis (TK), but no series exist to date with a significant number of hypokyphotic patients. In addition, the measures of TK in 2D are often wrong in severe AIS due to axial rotation. The goals of this study were therefore to analyze the 3D radiological outcomes of a group of hypokyphotic AIS patients operated with sublaminar bands.Methods35 consecutive AIS hypokyphotic patients (T4T12 <15°) operated in three centers were included, with a minimum 2-year follow-up. The surgical technique was similar in all centers, associating lumbar pedicle screws and thoracic sublaminar bands. Posteromedial translation was the main correction technique, and no patient underwent prior anterior release. 3D spinal reconstructions were performed preoperatively, postoperatively and at the latest follow-up by an independent observer using SterEOS (EOS imaging, Paris, France), and 2D and 3D measurements were compared. In addition, a new 3D parameter [sagittal shift of the apical vertebra (SSAV)], reflecting the translation of the apical vertebra of the main curve in the patient sagittal plane, was described and reported.ResultsThe age of the cohort was 16xa0years and the number of sublaminar bands used for correction averaged 6 (±1.5). T1T12 and T4T12 sagittal Cobb angles appeared to be overestimated on 2D postoperatively (3°, pxa0=xa00.002 and 4°, pxa0<xa00.001, respectively). Hence, only 3D measurements were kept for the quantitative analysis of the postoperative correction. T4T12 TK significantly increased after surgery (average 8°xa0±xa07°, pxa0<xa00.001), but 11 patients (31.4%) remained hypokyphotic. Seven out of the eight patients (87.5%) who presented a thoracic lordosis (i.e., T4T12 <0°) preoperatively were corrected after surgery (mean gain 16°xa0±xa04°). A posterior shift (positive SSAV) of the apical vertebra was reported in 24 patients (68.6%). In this subgroup, the mean SSAV was +2xa0cm (±1). Good correlation was found between the SSAV and the postoperative change in 3D T4T12 kyphosis (rxa0=xa00.62).ConclusionMeasures in 2D tend to overestimate sagittal alignment and are not sufficient to evaluate postoperative correction. SSAV is a new 3D parameter reflecting the TK change that needs to be further investigated and used in the future. This series confirms that sublaminar bands should be considered in hypokyphotic patients, since thoracic sagittal alignment was restored in 68.6% of the cases.

Sagittal spine posture assessment: Feasibility of a protocol based on intersegmental moments

Evaluation of spinal posture has recently benefited from the contribution of three-dimensional reconstruction technologies that have helped improve our understanding of this dynamic balance. The aim of this study was to present the preliminary results of a three-dimensional protocol to analyze postural balance. This analytical method is not limited by certain constraints of the radiological approach and evaluates postural balance using a new approach taking into account the net efforts of different intersegmental centers. These preliminary results show the technical feasibility of the protocol. Its future development and clinical use could provide a better understanding of postural balance disorders, and help evaluate the impact of surgical correction on spinal balance.

Medial patellofemoral ligament reconstruction in children: do osseous abnormalities matter?

PurposeManagement of post-traumatic patellar instability in children with osseous abnormalities is challenging because of the presence of an open physis. The aim of our study was to compare the rate of recurrence after isolated reconstruction of the medial patellofemoral ligament (MPFL) in children with or without osseous abnormalities.MethodsThe medical records of 25 children (27 knees) with recurrent patellar dislocation were reviewed. Each child underwent an isolated reconstruction of the MPFL using a hamstring graft. At the last follow-up, a clinical and radiographic evaluation was performed, including assessment of functional outcomes based on the Kujala score. Patients were compared in terms of the occurrence of a pre-existing osseous abnormality.ResultsThe mean age at the time of the surgery was 13.8xa0years. Eleven patients had trochlear dysplasia (40%), three had a patella alta (11%) and seven had an increased TT-TG (26%). The recurrence rate was 3.7% (one patient), after a mean follow-up of 41.1xa0months. Recurrence was not more frequent in patients with preoperative anatomical predisposing factors. The mean Kujala score was 95. The mean time to return to practicing sports was 7.1xa0months.ConclusionsIsolated MPFL reconstruction is an effective option for the management of post-traumatic patellofemoral instability in skeletally immature patients. The results of this technique seem to be independent on either proximal or distal misalignments such as trochlear dysplasia, patella alta, or increased TT-TG.