Neuromonitoring for spine surgery in children.

Neuromonitoring or electrophysiologic monitoring is now an essential component of pediatric spine surgery due to the high number of spinal deformity indications in asymptomatic patients, for whom any neurological complication would be disastrous. Technological advances have led to the development of compact monitors that allow surgeons themselves to monitor the motor evoked potentials (MEP) perioperatively. This shift happened because it was difficult to always have a neurophysiologist in the operating room. Unfortunately, this also means that multimodal monitoring (sensory, mixed, D-wave, electromyography, pedicle screws) is much more difficult to implement. There are absolute indications, such as any spinal deformity without neurological deficit and relative indications, which are more difficult to interpret. Technical incidents frequently occur before the start of the surgery. If no replacement device is available, the procedure must be cancelled unless the patient's life or function are at risk. At least two monitoring systems should be available at every facility to avoid having to cancel surgery for purely technological reasons. Once the surgical procedure has started, the absence of MEP recruitment curves in the upper and lower limbs is likely due to the anesthesia depth; the surgery should be stopped until this problem is corrected. When there is a true intraoperative alert (MEPs disappear in the lower limbs only), we propose taking the following steps, depending on whether the spine is stable or unstable: remove the causal implant, remove all hardware, preserve any stabilization devices, initiate an intraoperative wake-up test, verify conditions under which the intervention should continue. Level of evidence: V.

Tibia Valga Correction by Extraperiosteal Fibular Release in Multiple Exostosis Disease.

Genu valgum is a frequent deformity encountered in Multiple Hereditary Exostosis (MHE) patients. If left untreated, lower limb deformity leads to poor functional outcomes in adulthood. Our hypothesis was that in some cases, fibular shortening would lead to a lateral epiphysiodesis-like effect on the tibia. We herein report the case of a 6-year-old child with MHE who underwent extraperiosteal resection of the fibula for tibia valga correction. To obtain the lateral release of the calf skeleton, resection included inter-tibio-fibular exostosis along with proximal fibular metaphysis and diaphysis without any osseous procedure on the tibia. Gradual improvement of the valgus deformity occurred during follow-up (HKA from 165° preop to 178° at 27-month follow-up). Lateral release of the fibula led to an increase in the fibula/tibia index (from 93% preop to 96% at follow-up). Studying fibular growth in MHE patients could help understand how valgus deformity occurs in these patients. Even if encouraging, this result is just the report of a unique case. Further research and a larger series of patients are required to assess fibular release as a valuable option to treat valgus deformity in MHE.

Diffusion-weighted imaging in differentiating mid-course responders to chemotherapy for long-bone osteosarcoma compared to the histologic response: an update.

BACKGROUND: Diffusion-weighted imaging (DWI) has been described to correlate with tumoural necrosis in response to preoperative chemotherapy for osteosarcoma. OBJECTIVE: To assess the accuracy of DWI in evaluating the response to neoadjuvant chemotherapy at the mid-course treatment of long-bone osteosarcoma and in predicting survival. MATERIALS AND METHODS: We conducted a prospective single-centre study over a continuous period of 11 years. Consecutive patients younger than 20 years treated with a neoadjuvant regimen for peripheral conventional osteosarcoma were eligible for inclusion. Magnetic resonance imaging (MRI) with DWI was performed at diagnosis, and mid- and end-course chemotherapy with mean apparent diffusion coefficients (ADC) calculated at each time point. A percentage less than or equal to 10% of the viable residual tissue at the histological analysis of the surgical specimen was defined as a good responder to chemotherapy. Survival comparisons were calculated using the Kaplan-Meier method. Uni- and multivariate analyses with ADC change were performed by Cox modelling. This is an expansion and update of our previous work. RESULTS: Twenty-six patients between the ages of 4.8 and 19.6 years were included, of whom 14 were good responders. At mid-course chemotherapy, good responders had significantly higher mean ADC values (P=0.046) and a higher increase in ADC (P=0.015) than poor responders. The ADC change from diagnosis to mid-course MRI did not appear to be a prognosticator of survival and did not impact survival rates of both groups. CONCLUSION: DWI at mid-course preoperative chemotherapy for osteosarcoma should be considered to evaluate the degree of histological necrosis and to predict survival. The anticipation of a response to neoadjuvant treatment by DWI may have potential implications on preoperative management.

Can the TrueLok Hexapod System™ be used to accurately correct lower limb deformity in children?

INTRODUCTION: Progressive bone lengthening in children can be done using an external fixator, a lengthening nail, or plate with screws. The TrueLok Hexapod System™ (TL-HEX™) is the newest hexapod external fixator on the market. We hypothesized that the TL-HEX™ can accurately correct lower limb deformities in children. The goal of this study was to evaluate the clinical and radiographic outcomes after correcting lower limb deformities in children using the TL-HEX™ system. MATERIAL AND METHODS: Data from 58 limbs that underwent bone lengthening with the TL-HEX™ were analyzed for this retrospective, single-center study. The average patient age was 11.4 years. The femur was lengthened in 23 limbs and the tibia in 35. The outcomes were evaluated using long leg standing radiographs preoperatively and at the final assessment. The variables of interest were the mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), mechanical lateral proximal tibia angle (mMPTA), healing index (HI) and accuracy of the correction. The complications were graded on a 4-point scale summarizing three broad goals: planned correction, duration of treatment and sequelae. The accuracy of the correction was defined as the difference between the planned correction and the actual correction achieved. RESULTS: The mean HI was 37 days/cm. Significant correction was achieved for leg length discrepancy (LLD) (60 mm vs. 20 mm; p<0.01) and mLDFA (88.6° vs. 89.9°; p=0.04) but not the MAD (17.7 vs. 14.7; p= 0.17) or mMPTA (87.3 vs. 88.1; p=0.08). In the entire cohort, the difference from planned was 12.5 mm (p<0.01) for lengthening, 1.3° for the mLDFA (p=0.5) and 3° for the mMPTA (p=0.02). Relative to the initial goal, the mean lengthening achieved was 118%. In the sub-group where the plan did not need to be modified, the accuracy of the correction was better. There were 40 complications (69%). CONCLUSION: The TL-HEX™ is an effective and accurate system. The complication rate associated with its use is the same as other hexapod external fixators. Surgeons and patients must be aware of the high complication rate, which may require the plan to be modified and could potentially compromise the outcome.

First Sternal Cleft Repair Using a Porous Alumina Ceramic Prosthesis in a 9-Year-Old Child.

Sternal cleft is a rare congenital abnormality, often associated with other congenital defects. We present the case of a 9-year-old child with complete sternal cleft, treated with an innovative sternal prosthesis. Surgery was performed to protect the heart and also, as pulsations was visible, leading to serious esthetical concerns, to enhance school integration, which was difficult. The porous alumina device used was initially designed for sternal reconstruction after refractory deep sternal wound infection or carcinoma. Surgery and early follow-up were simple. There was no complication and the follow-up of more than 1 year reveals a good healing without breath discomfort and a correct development of the chest wall. In this rare indication, the alumina ceramic sternal prosthesis offers a reliable alternative to classical methods, such as muscle flap, autogenous tissue transfer, costal homograft, and other prosthetic materials like mesh or synthetic patch.

Knee function after limb salvage surgery for malignant bone tumor: comparison of megaprosthesis and distal femur allograft with epiphysis sparing.

PURPOSE: Limb salvage surgery is increasingly used for the treatment of distal femur bone sarcomas. Total knee replacement using megaprosthesis and epiphysis-sparing biologic reconstruction using an allograft are widely used in order to preserve joint motion. We aimed to compare the results of these procedures using gait analysis in patients undergoing limb salvage surgery. METHODS: Fifteen patients were included, nine undergoing allograft with epiphysis sparing (Allograft group) and six undergoing megaprosthesis (Megaprosthesis group). Every patient underwent a gait analysis using the Plug-in-Gait protocol. Spatiotemporal parameters, knee kinematics, and kinetics were compared between the two groups and a cohort of ten asymptomatic subjects. Knee function was assessed by the Gait Deviation Index (GDI) and the Gilette Gait Index (GGI). RESULTS: Both treatment groups showed decreased knee flexion during the loading response phase. Megaprosthesis patients showed a decreased knee flexion all along stance phase. There was no difference in gait pattern between the treatment groups. GDI was significantly lower in Megaprosthesis and Allograft patients when compared to controls (86.4 and 84.3 vs 94, all p < 0.05). This difference was not clinically relevant. CONCLUSION: Our study reveals that Megaprosthesis and Allograft patients did not show differences in gait patterns and global function. Even though Allograft and Megaprosthesis patients have significant changes in gait pattern, knee function is acceptable with effective gait mechanisms. Changes occur during stance phase and are due to the quadriceps weakness. The particular pattern of gait in Megaprosthesis patients could be a concern for prosthesis wear and should be investigated on this specific aspect. LEVEL OF EVIDENCE: 4.

Experience and volume are determinantive factors for operative management of supracondylar humeral fractures in children.

BACKGROUND: We compared radiographic and operative results of pediatric patients undergoing surgical treatment of displaced supracondylar humeral fracture (SCHF) according to the surgeon's experience. METHODS: During an 11-year period (2006-2016), we reviewed the medical records of 236 patients operated on for Gartland III SCHF in our institution. Operative (operative time, time to implants removal) and radiographic parameters (Baumann and lateral capitellohumeral angles) were assessed. A malalignment was defined if there was a difference in the Baumann angle or lateral capitellohumeral angles >15° or if malrotation existed compared with normative values. We compared surgeon experience and volume (number of patients operated on by year). RESULTS: In patients operated on by less experienced surgeons (<1 year, n = 69), operative time (61 vs. 41 minutes) and time to implant removal (48 vs. 40 days) were significantly longer (P < .001). Radiographic parameters did not differ between less and more experienced surgeons. Operative parameters improved through the 20 first cases of the younger surgeons. In surgeons managing fewer than 5 patients per year, malalignment and conversion to open reduction were more frequent (all P < .05). CONCLUSION: Experience and volume are 2 crucial parameters influencing the quality of management of pediatric patients undergoing surgical treatment for displaced SCHF. They should be taken into account in daily practice, especially when making the decision to operate on these patients out of day time.

Bone substitutes in adolescent idiopathic scoliosis surgery using sublaminar bands: is it useful? A case-control study.

INTRODUCTION: In order to avoid pseudarthrosis in adolescent idiopathic (AIS) patients, it is recommended to bring additional bone graft or substitute. Modern rigid instrumentations have been shown to provide less pseudarthroses even without bone substitutes. The aim of our study was to determine the impact of using bones substitutes on fusion rates in adolescent idiopathic scoliosis patients undergoing PSF with sublaminar bands. METHOD: AIS patients scheduled to undergo PSF with sublaminar bands were prospectively enrolled into this study and not given any bone substitutes (no-substitute group). Data were collected and analyzed in patients with at least two years of follow-up. Pseudarthrosis was diagnosed if at least one of the following was present: persistent back pain, hardware failure, loss of correction greater than 10°. The results were compared to a control group who received bone substitutes for the same surgical procedure. RESULTS: Eighty-eight patients were included. For the whole cohort, the mean age was 14.8 years old and the mean follow-up was 30.9 months. For the 'no-substitute' group (n = 44), the mean Cobb angle was 56° pre-operatively, 20.1° post-operatively, and 22° at final follow-up. The fusion rate was not statistically different between the two groups (97.7% vs 95.5%, p = 0.56). At last follow-up, one pseudarthrosis occurred in the 'no substitute' group and two in the control group. DISCUSSION: This is the first study to determine the impact of bone substitutes in AIS fusion using sublaminar bands. In our study, the use of local autologous bone graft alone resulted in a fusion rate of 97.7% despite the use of more flexible instrumentation. The high rate of fusion in AIS patients is more probably due to the healing potential of these young patients rather than to the type of instrumentation. CONCLUSION: The use of additional bone graft or bone substitutes may not be mandatory when managing AIS. LEVEL OF EVIDENCE: 4.

Spinal alignment evolution with age: A prospective gait analysis study.

AIM: To describe, using gait analysis, the development of spinal motion in the growing child. METHODS: Thirty-six healthy children aged from 3 to 16 years old were included in this study for a gait analysis (9 m-walk). Various kinematic parameters were recorded and analyzed such as thoracic angle (TA), lumbar angle (LA) and sagittal vertical axis (SVA). The kinetic parameters were the net reaction moments (N.m/kg) at the thoracolumbar and lumbosacral junctions. RESULTS: TA and LA curves were not statistically correlated to the age (respectively, P = 0.32 and P = 0.41). SVA increased significantly with age (P < 0.001). Moments in sagittal plane at the lumbosacral junction were statistically correlated to the age (P = 0.003), underlining the fact that sagittal mechanical constraints at the lumbosacral junction increase with age. Moments in transversal plane at the thoracolumbar and lumbosacral junctions were statistically correlated to the age (P = 0.0002 and P = 0.0006), revealing that transversal mechanical constraints decrease with age. CONCLUSION: The kinetic analysis showed that during growth, a decrease of torsional constraint occurs while an increase of sagittal constraint is observed. These changes in spine biomechanics are related to the crucial role of the trunk for bipedalism acquisition, allowing stabilization despite lower limbs immaturity. With the acquisition of mature gait, the spine will mainly undergo constraints in the sagittal plane.

How Sublaminar Bands Affect Postoperative Sagittal Alignment in AIS Patients with Preoperative Hypokyphosis? Results of a Series of 34 Patients with 2-Year Follow-Up.

Hypokyphosis is currently observed in thoracic idiopathic scoliosis. The use of sublaminar bands allows a good restoration of sagittal balance of the spine. The aim of the study was to provide a middle-term radiographic analysis of patients with adolescent idiopathic scoliosis with preoperative hypokyphosis treated by posterior arthrodesis with sublaminar bands. This retrospective study included 34 patients with Lenke 1 scoliosis associated with hypokyphosis (TK < 20°). A radiographic evaluation was performed with a 2-year follow-up. Cobb angle, cervical lordosis, thoracic kyphosis, lumbar lordosis, and pelvic parameters were measured preoperatively, postoperatively, and at 6-month and 2-year follow-up. The mean preoperative thoracic kyphosis was 10.5° versus 24.1° postoperatively (p < 0.001), representing a mean gain of 13°. Cobb angle ranged from 59.3° to 17.9° postoperatively (mean correction 69%, p < 0.001). Cobb angle increased between the immediate postoperative measurement and the 6-month follow-up (17.9 versus 19.9, p = 0.03). Cervical curvature changed from a 5.6° kyphosis to a 3.5° lordosis (p = 0.001). Concerning lumbar lordosis, preoperative measurement was 39.7° versus 41.3° postoperatively (p = 0.27). At 6-month follow-up, lumbar lordosis significantly increased to 43.6° (p = 0.03). All parameters were stable at final follow-up. Correction performed by sublaminar bands is efficient for both fontal and sagittal planes. Moreover, the restoration of normal thoracic kyphosis is followed by an adaptation of the adjacent curvatures with improved cervical lordosis and lumbar lordosis.

Small bowel entrapment and ureteropelvic junction disruption associated with L3 Chance fracture-dislocation.

Paediatric Chance fracture are rare lesions but often associated with abdominal injuries. We herein present the case of a seven years old patient who sustained an entrapment of small bowel and an ureteropelvic disruption associated with a Chance fracture and spine dislocation following a traffic accident. Initial X-rays and computed tomographic (CT) scan showed a Chance fracture with dislocation of L3 vertebra, with an incarceration of a small bowel loop in the spinal canal and a complete section of the left lumbar ureter. Paraplegia was noticed on the initial neurological examination. A posterior L2-L4 osteosynthesis was performed firstly. In a second time she underwent a sus umbilical laparotomy to release the incarcerated jejunum loop in the spinal canal. An end-to-end anastomosis was performed on a JJ probe to suture the left injured ureter. One month after the traumatism, she started to complain of severe headaches related to a leakage of cerebrospinalis fluid. Three months after the traumatism there was a clear regression of the leakage. One year after the trauma, an anterior intervertebral fusion was done. At final follow-up, no neurologic recovery was noticed. In case of Chance fracture, all physicians should think about abdominal injuries even if the patient is asymptomatic. Initial abdominal CT scan and magnetic resonance imaging provide in such case crucial info for management of the spine and the associated lesions.

Experience in Perioperative Management of Patients Undergoing Posterior Spine Fusion for Neuromuscular Scoliosis.

The objective of this investigation was to determine the outcome of spine fusion for neuromuscular (NM) scoliosis, using Unit Rod technique, with emphasis on complications related to preoperative general health. Between 1997 and 2007, 96 consecutive patients with neuromuscular scoliosis operated on with Unit Rod instrumentation were retrospectively reviewed. The inclusion criteria were diagnosis of NM scoliosis due to cerebral palsy (CP) and muscular dystrophy (DMD). Patient's preoperative general health, weight, and nutrition were collected. Different radiographic and clinical parameters were evaluated. There were 66 CP patients (59 nonwalking) and 30 DMD patients (24 nonwalking). Mean age at surgery was 16.5 years and 13.9 years, respectively. All radiographic measurements improved significantly. Wound infection rate was 16.7% (11% of reoperation rate in CP; 10% in DMD; 3 hardware removal cases). No pelvic fracture due to rod irritation was observed. Unit Rod technique provides good radiographic and clinical outcomes even if this surgery is associated with a high complication rate. It is a quick, simple, and reliable technique. Perioperative management strategy should decrease postoperative complications and increases outcome. A standardized preoperative patient evaluation and preparation including respiratory capacity and nutritional, digestive, and musculoskeletal status are mandatory prior to surgery.

Corpectomy and Vertebral Body Reconstruction with Expandable Cage Placement and Osteosynthesis via the single stage Posterior Approach: a Retrospective Series of 34 Patients with Thoracic and Lumbar Spine Vertebral Body Tumors.

BACKGROUND: Metastatic disease of the spine requires a multidisciplinary and comprehensive approach to patient care, especially, for patients in a lot of pain with neurological deficit or spinal instability requiring surgical stabilization. OBJECTIVES: The purpose of the study is to report our experience on 34 patients who underwent spinal metastasis resection. We used a single-stage posterior approach with vertebral body reconstruction by an expandable titanium cage and a posterior instrumentation. The parameters assessed were neurologic status, OMS score, angle of sagittal deformity, and morbidity. METHODS: Between January 2011 and June 2014 we performed a monocentric consecutive case review of 34 patients with vertebral body tumor. All of them underwent a single-stage vertebrectomy with circumferential reconstruction and an arthrodesis by posterior approach. RESULTS: 34 patients underwent a single stage surgery by posterior approach, including 30 thoracic lesions and 4 lumbar lesions. Pre operatively, sixteen patients presented a neurologic impairment. The mean follow-up was 13.7 months [1-32 m]. No neurologic impairment was observed in the 34 cases. At the last term of follow-up, neurologic status was improved in 23 cases. OMS score was improved in 23 cases (67.6 %), and worsened in one case. Before surgery, the average of visual analogic scale was 8.94/10 [7-10] and decreased to 2.62/10 [1-5] after surgery. Single posterior approach surgery significantly reduced the average sagittal deformity to 10.0° (0.01-19.96; P = 0.013, Mann-Whitney test). CONCLUSION: Our outcomes suggest that it will be more efficient to perform an aggressive approach in spinal metastatic treatment in order to improve quality of life.

Percutaneous cement-augmented screws fixation in the fractures of the aging spine: is it the solution?

INTRODUCTION: Management of elderly patients with thoracolumbar fractures is still challenging due to frequent osteoporosis and risk of screws pull-out. The aim of this study was to evaluate results of a percutaneous-only procedure to treat these fragile patients using cement-augmented screws. METHODS: 12 patients diagnosed with a thoracolumbar fracture associated with an important loss of bone stock were included in this prospective study. Surgical procedure included systematically a percutaneous osteosynthesis using cemented fenestrated screws. When necessary, additional anterior support was performed using a kyphoplasty procedure. Clinical and radiographic evaluations were performed using CT scan. RESULTS: On the whole series, 15 fractures were diagnosed and 96 cemented screws were inserted. The difference between the pre- and postoperative vertebral kyphosis was statistically significant (12.9° versus 4.4°, P = 0.0006). No extrapedicular screw was reported and one patient was diagnosed with a cement-related pulmonary embolism. During follow-up period, no infectious complications, implant failures, or pull-out screws were noticed. DISCUSSION: Aging spine is becoming an increasing public health issue. Management of these patients requires specific attention due to the augmented risk of complications. Using percutaneous-only screws fixation with cemented screw provides satisfactory results. A rigorous technique is mandatory in order to achieve best outcomes.