Convex Growth Arrest Research Articles

The Efficiency of Epiphysiodesis for Growth Modulation in Patients with Congenital Scoliosis: A Systematic Review

Purpose: Congenital scoliosis (CS) is a challenging entity in spinal surgery. Convex growth arrest (CGA) is a therapeutic method aiming at inhibiting growth on the curve convexity while remained growth of concavity corrects the scoliotic curve over time. In the view of controversies in current clinical studies for efficiency of CGA in CS patients, we performed a systematic review of the literature to clarify the debate. Methods: A comprehensive literature search was performed to identify studies assessing CGA outcome in CS patients, in following databases and search engines: Ovid MEDLINE, PubMed, Scopus, Cochrane Central Register of Controlled Trials (CCTR), EMBASE, Google Scholar, and Web of Science. Two authors screened the search results and selected the studies by the supervision of senior authors.Results: In 19 studies, enrolling 363 patients, age at surgery was 58.76 months ranging from 4 to 216 months. Anterior and posterior hemiepiphysiodesis was the most common approach. Eight studies added instrumentation to CGA. Follow-up mean was 64.57 months. Nine studies reported true epiphysiodesis effect (postoperative and final follow-up CCA difference): of 162 patients, 69 improved, 59 stabilized, and 34 progressed. Other studies reported preoperative and final follow-up CCA difference: of 88 patients, 49 improved, 32 stabilized, and 7 progressed. Preoperative curve magnitude, sagittal plane deformities, age <5 years, and type of spinal anomalies did not affect CGA outcome. Instrumentation was preferred in complicated spinal anomalies and older ages.Conclusion: CGA alone or with instrumentation is a feasible CS treatment, however criteria for choosing suitable candidates need reconsideration.

Assessing the unique characteristics associated with surgical treatment of dystrophic lumbar scoliosis secondary to neurofibromatosis type 1: a single-center experience of more than 10 years.

Dystrophic lumbar scoliosis secondary to neurofibromatosis type 1 (DLS-NF1) may present an atypical, unique curve pattern associated with a high incidence of coronal imbalance and regional kyphosis. Early surgical intervention is complicated and risky but necessary. The present study aimed to assess the unique characteristics associated with the surgical treatment of DLS-NF1. Thirty-nine consecutive patients with DLS-NF1 treated surgically at a mean age of 14.4 ± 3.9 years were retrospectively reviewed. Patients were stratified into three types according to the coronal balance classification: type A (C7 translation < 30 mm), 22 patients; type B (concave C7 translation ≥ 30 mm), 0 patients; and type C (convex C7 translation ≥ 30 mm), 17 patients. Types B and C were considered to be coronal imbalance. The diversity of surgical strategies, the outcomes, and the related complications were analyzed. The posterior-only approach accounted for 79.5% in total; the remaining 20.5% of patients received either additional anterior supplemental bone grafting (12.8%) to strengthen the fixation or convex growth arrest (7.7%) to reduce growth asymmetry. The lower instrumented vertebra (LIV) being L5 accounted for the largest share (41%), followed by L4 and above (35.9%), the sacrum (15.4%), and the pelvis (7.7%). Type C coronal imbalance was found in 23 patients (59%) postoperatively, and the incidence was significantly higher in the preoperative type C group (14/17 type C vs 9/22 type A, p = 0.020). All the patients with postoperative coronal imbalance showed ameliorative transition to type A at the last visit. The rate of screw malposition was 30.5%, including 9.9% breached medially and 20.6% breached laterally, although no serious neurological impairment occurred. The incidence of rod breakage was 16.1% (5/31) and 0% in patients with the posterior-only and combined approaches, respectively. Four revisions with satellite rods and 1 revision with removal of iliac screw for penetration into the hip joint were performed. Surgical strategies for DLS-NF1 were diverse across a range of arthrodesis and surgical approaches, being crucially determined by the location and the severity of dystrophic changes. The LIV being L5 or lower involving the lumbosacral region and pelvis was not rare. Additional posterior satellite rods or supplementary anterior fusion is necessary in cases with insufficient apical screw density. Despite a high incidence of postoperative coronal imbalance, improvement of coronal balance was frequently confirmed during follow-up. Neurological impairment was scarce despite the higher rate of screw malposition.

Is There Still a Place for Convex Hemiepiphysiodesis in Congenital Scoliosis in Young Children? A Long-Term Follow-up.

Study Design:Retrospective cohort.Objectives:To evaluate the long-term effect of convex growth arrest (CGA) on coronal deformity correction in congenital scoliosis.Methods:Twenty-two patients with congenital scoliosis operated by 1-staged double approach hemiephysiodesis by bone grafting of the convex side without instrumentation are included. Eighteen curves had an isolated hemivertebra while 4 curves had congenital bar. Subgroup analysis was performed according to age at surgery (3 years cutoff), type of malformation (hemivertebra vs congenital bar), and severity of curve (35° cutoff).Results:Patients’ mean age at surgery was 3 years (range 0.5-8 years), with a mean frontal Cobb angle of 40.59°. Mean follow-up is 10.7 years (range 5.5-25 years). Overall results showed mean frontal Cobb angle reduction of 35.47% (40.59° to 27.41°). Detailed analysis showed that 15 curves had a mean correction of 51.8%, 5 stabilized and 2 had a mean aggravation of 25.11%. Subgroup analysis revealed that patients operated ≤3 years of age had mean cobb angle correction of 43.1% versus 21.49% in patients operated >3 years (P = .140). Mean correction of 44.5% was gained in curves with isolated hemivertebra compared with 1.3% in curves with congenital bar (P = .004). A 58.17% mean correction was reached in curves ≤35° versus 23.68% in curves >35° (P = .032).Conclusions:A limited convex hemiepiphysiodesis still has a place in congenital scoliosis care when it is performed in patients ≤3 years old, with curves ≤35°, and with isolated hemivertebra. It spares patients the risks of vertebral resection and instrumentation, while fusing the same number of levels.

Convex Instrumented Hemiepiphysiodesis With Concave Distraction: A Treatment Option for Long Sweeping Congenital Curves.

Convex hemiepiphysiodesis has been reported to have mixed results in the treatment of congenital spine deformities. Multiple modifications of the original technique were suggested to improve the results. The purpose of this study is to report the results and complications of an instrumented convex growth arrest procedure modified with concave distraction. The records of 11 patients with long sweeping congenital curves (involving multiple anomalous vertebrae) who underwent convex instrumented hemiepiphysiodesis with concave distraction were evaluated. Mean age at index operation was 58 months (range, 29 to 101 mo). Lengthening of the concave distraction rod was done every 6 months. The magnitude of coronal/sagittal deformity and T1-T12 height were measured on the preoperative, postoperative, and latest follow-up radiographs. Average follow-up was 44.9 months (range, 24 to 89 mo). In the coronal plane, the convex hemiepiphysiodesis segment was corrected from an average of 60.5 to 40.4 degrees postoperatively and further improved to 35.5 degrees at the latest follow-up. The distracted segment was corrected from 33.4 to 15.2 degrees postoperatively and to 12.7 degrees at the latest follow-up. Sagittal plane alignment was minimally affected. The average T1-T12 height was 157.1 mm in the early postoperative period and 181.1 mm at last follow-up. During follow-up, we identified partial pull-out of screws on the distraction side in 5 of the 11 patients and rod breakages in 3 patients. These were revised during planned lengthenings. There were no unplanned surgeries, deep wound infections, nor neurological complications. Convex instrumented hemiepiphysiodesis with concave distraction resulted in good curve correction while maintaining the growth of thorax. The correction of the anomalous segment improved over time, proving the effectiveness of the hemiepiphysiodesis. Addition of a concave distraction construct appears to enhance spinal growth, thereby augmenting the hemiepiphysiodesis effect.

Early diagnosis and treatment of congenital hemivertebra malformation

Hemivertebra (HV) is a congenital spinal abnormality due to a defection of formation of one side vertebral.It is divided into 3 types according to whether it fusion with adjacent vertebral: fully segmented, semi-segmented and incarcerated.HV deformity is diagnosed depending on clinical symptoms, X rays, CT and other examine.Preoperative magnetic resonance imaging of the spine, genitourinary and cardiac ultrasound should be performed at the same time.Congenital scoliosis due to HV especially fully segmented is nonresponsive to bracing, operative treatment is the mainstay of care.The 3 basic operations are fusion in situ, convex growth arrest(epiphysiodesis), and HV resection.The single posterior approach or combined anterior and posterior approach of HV resection with instrumentation is the main method now. Key words: Hemivertebra malformation; Operation treatment; Child

Safety and Efficacy of Instrumented Convex Growth Arrest in Treatment of Congenital Scoliosis

Anterior and posterior convex hemiepiphysiodesis is a widely used surgical alternative in the treatment of congenital scoliosis. This procedure has the disadvantage of the need for both anterior and posterior approaches. Furthermore, outcomes may be unpredictable. Posterior convex growth arrest (CGA) with pedicle screws at each segment on the convex side may obviate the need for anterior surgery and provides more predictable outcomes. This study retrospectively evaluates the safety and efficacy of instrumented posterior CGA in congenital scoliosis. Patients who had posterior CGA with convex pedicle screw instrumentation for congenital scoliosis were evaluated retrospectively. Thirteen patients (6 male, 7 female) were included in the study. Preoperative, early postoperative, and last follow-up standing posteroanterior and lateral x-rays were evaluated. Cobb angles were recorded for the instrumented segment (main curve). Global thoracic kyphosis was measured between T2 and T12 on sagittal plane. These values were compared preoperatively, postoperatively, and at last follow-up. The T1-S1 vertical height and the height between the concave side pedicles of the upper and lower end vertebra of the main curve was also determined and recorded as the concave height. The average follow-up was 56.1±10 months (range, 36 to 74 mo) and the average age of the patients at the time of operation was 64.5±30.1 months (range, 15 to 108 mo). All patients were Risser zero at the time of surgery. The average curve magnitude was 49±10.9 degrees (range, 34 to 68 degrees) preoperatively, 38.3±9.7 degrees (range, 28 to 58 degrees) early postoperatively, and 33.5±12.4 degrees (16 to 52 degrees) at last follow-up. There was a significant difference between the preoperative and early postoperative main curve Cobb angle measurements (P=0.001). The average concave height was 94.2±20.2 mm in the early postoperative period and 104.7±21.7 mm at last follow-up (P=0.003). The average T1-S1 height was 292.1±67.1 mm in the early postoperative period and 363.9±94.5 mm at last follow-up (P=0.005). There was at least ≥5 degrees improvement in 9 of the 12 patients in the follow-up period after the index procedure. In 3 patients, the curve did not change and the correction was maintained. Curve progression was observed in 1 patient due to a technical error. There were no wound infections or instrumentation failures during follow-up. Instrumented CGA can safely be used in long sweeping curves of immature spines. Using this technique; thoracotomy, anterior procedure, and 2-stage surgery can be avoided. Moreover, it guarantees some degree of correction in all patients because of the instrumentation effect, eliminating the unpredictable nature of classic CGA. Therapeutic level IV study.

Circumferential convex growth arrest by posterior approach for double cervicothoracic curves in congenital scoliosis

Hemivertebra resection is a standard treatment for congenital scoliosis due to an isolated hemivertebra. There is no well-defined treatment for hemivertebra associated with an opposite concave bar. Vertebral column resection, concave distraction and epiphysiodesis are possible options. The goal of convex epiphysiodesis is to stop the spinal growth at the convex side anteriorly and posteriorly. This is usually done with combined anterior and posterior approaches. The use of pedicle screws and rigid posterior instrumentation enable posterior and anterior growth arrest by blocking the vertebral body cartilage as it is used to be in long bone metaphysis by Blount staple. We report a case requiring growth arrest at two segments to stop the progression of two congenital spinal curves.

Convex Instrumented Hemiepiphysiodesis with Concave Distraction: A Preliminary Report

The convex growth arrest (CGA) procedure has been well accepted for treatment of congenital scoliosis as it is a simpler procedure with successful results. However, unpredictability of curve behavior, slow and usually inadequate correction, and necessity of anterior surgery for completeness of the epiphysiodesis are its shortcomings. In a preliminary study we asked whether a modification of the CGA procedure using convex instrumented hemiepiphysiodesis with concave distraction would correct the coronal plane Cobb angles and would correct or maintain sagittal plane local and global kyphosis angles. We also identified complications. We retrospectively reviewed five female patients who underwent the modified procedure. Their mean age at the index operation was 40 months (range, 17-55 months). The patients underwent concave distractions every 6 months. The magnitude of the convex instrumented and concave distracted curves and sagittal plane parameters were determined on the preoperative and most recent followup radiographs. Minimum followup was 26 months (mean, 34 months; range, 26-40 months). In the coronal plane, the preoperative magnitude of the convex instrumented congenital curve averaged 48°. It was corrected to 36° (25%) postoperatively and was further improved to 27° (44%) at the latest followup. For the distracted segment, the mean preoperative curve was 35°, corrected to 16° postoperatively and to 8° at the latest followup, for an average correction of 77%. Sagittal plane alignment was minimally affected from the procedure. In four of the five patients we identified partial pullout of screws for the concave distraction; these were revised at the time of planned lengthening. This procedure may obviate the need for multiple osteotomies and long thoracic fusions in young children with long sweeping thoracic deformities involving multiple anomalous vertebrae. Implant-related complications on the concave side may be avoided using paired pedicle screws at the proximal and distal anchor sites. Level IV, therapeutic study. See the guidelines online for a complete description of level of evidence.

Growth modulation in the management of growing spine deformities.

The Hueter-Volkmann law explains the physiological response of the growth plate under mechanical loading. This law mainly explains the pathological mechanism for growing long-bone deformities. Vertebral endplates also show a similar response under mechanical loading. Experimental studies have provided information about spinal growth modulation and, now, it is possible to explain the mechanism of the curvature progression. Convex growth arrest is shown to successfully treat deformities of the growing spine and unnecessary growth arrest of the whole spine is prevented. Both anterior and posterior parts of the convexity should be addressed to achieve a satisfactory improvement in the deformity, albeit epiphysiodesis effect cannot be stipulated at all times. Anterior vertebral body stapling without fusion yielded better results with new shape memory alloys and techniques. This method can be used with minimally invasive techniques and has the potential advantage of producing reversible physeal arrest. Instrumented posterior hemiepiphysiodesis seems to be as effective as classical combined anterior and posterior arthrodesis, where it is less invasive and morbid. Convex hemiepiphysiodesis with concave-side distraction through growing rod techniques provide a better control of the curve immediately after surgery. This method has the advantages of posterior instrumented hemiepiphysiodesis, but necessitates additional surgeries. Concave-side rib shortening and/or convex-side lengthening is an experimental method with an indirect effect on spinal growth. To conclude, whatever the cause of the spinal deformity, growth modulation can be used to manage the growing spine deformities with no or shorter segment fusions.

Convex Growth Arrest in the Treatment of Congenital Spinal Deformities, Revisited

The authors studied 32 patients to delineate the reliability of well-defined but frequently extended indications to define the ideal patient who will benefit from convex growth arrest. Mean age at the time of convex growth arrest was 29 (range 6-72) months, and average follow-up was 40 (24-120) months. Mean Cobb angle was 55 degrees (31-105 degrees) before surgery and 50 degrees (13-107 degrees) at final follow-up. Thirteen patients (41%) had a true epiphysiodesis effect, while 15 (47%) had fusion and 4 (12%) had progression. The age at surgery, magnitude, length and location of the curve, presence of intraspinal anomaly, and presence of sagittal plane or rib deformity were investigated in terms of the outcome, but none of these parameters was found to have an effect on the outcome. In conclusion, convex growth arrest is a safe and effective method in the management of the young patients with congenital spinal deformities. It can be performed for the balanced and cosmetically acceptable deformities of patients younger than 5 years of age regardless of the type, length, magnitude, and location of the curve, the existence of associated rib fusion, or the presence of sagittal plane abnormality.

Convex Growth Arrest in the Treatment of Congenital Spinal Deformities, Revisited

The authors studied 32 patients to delineate the reliability of well-defined but frequently extended indications to define the ideal patient who will benefit from convex growth arrest. Mean age at the time of convex growth arrest was 29 (range 6-72) months, and average follow-up was 40 (24-120) months. Mean Cobb angle was 55 degrees (31-105 degrees) before surgery and 50 degrees (13-107 degrees) at final follow-up. Thirteen patients (41%) had a true epiphysiodesis effect, while 15 (47%) had fusion and 4 (12%) had progression. The age at surgery, magnitude, length and location of the curve, presence of intraspinal anomaly, and presence of sagittal plane or rib deformity were investigated in terms of the outcome, but none of these parameters was found to have an effect on the outcome. In conclusion, convex growth arrest is a safe and effective method in the management of the young patients with congenital spinal deformities. It can be performed for the balanced and cosmetically acceptable deformities of patients younger than 5 years of age regardless of the type, length, magnitude, and location of the curve, the existence of associated rib fusion, or the presence of sagittal plane abnormality.

Convex Growth Arrest for Progressive Congenital Scoliosis Due to Hemivertebrae

Thirteen patients with progressive congenital scoliosis due to hemivertebrae or hemivertebrae associated with other spinal anomalies were treated by convex anterior and posterior hemiarthrodesis and hemiepiphysiodesis. The average curve prior to operation was 46 degrees, average age was 3 years 6 months, and average followup was 6 years 6 months. One patient failed because of an inadequate length of anterior surgery which was successfully salvaged by further surgery. Twelve patients were successes: Seven had only cessation of the progressive curve, and five had progressive curve improvement greater than or equal to 5 degrees due to the arrested convex and persistent concave growth. This procedure is a valuable treatment modality for selected patients with congenital scoliosis.