Growth arrest for progressive scoliosis. Combined anterior and posterior fusion of the convexity

Continued deterioration in pulmonary function at average 23-year follow-up from early thoracic fusion in non-neuromuscular scoliosis

PURPOSE

Historically, early-onset scoliosis was treated with early fusion to prevent further deformity at the expense of thoracic growth. This has proven to have a detrimental effect on pulmonary function. The purpose of this study is to evaluate patients' pulmonary and functional status at long-term follow-up after undergoing thoracic fusion at a young age.

METHODS

All patients at a single institution who had undergone thoracic spinal fusion prior to age nine with minimum 13-year follow-up were eligible. Patients underwent pulmonary function testing, radiographic analysis, and functional testing. Results were compared to the patients' previous pulmonary function data at average of 11 years post-surgery.

RESULTS

Fifteen out of twenty-eight eligible patients returned for testing. The average age at the time of surgery was 3.3 years (range 0.9-8.4 years) with follow-up of 23.6 years (range 13.2-33.2 years). There was a statistically significant interval decline in predicted forced vital capacity (42.8% versus 54.7% of normal predicted values, p = 0.0001) and predicted forced expiratory volume in one second (42.2% versus 55.2% of normal predicted values, p = 0.0001) when compared to previous follow-up. There was a strong positive correlation between thoracic height and forced vital capacity (r = 0.925, p = 0.002).

CONCLUSIONS

Pulmonary function in patients who had undergone thoracic spinal fusion for scoliosis prior to the age of six continues to decline into adulthood at a rate that is faster than that of their peers. The majority of these patients have clinically important restrictive lung disease, which can be fatal. Alternative treatment strategies should be considered.

LEVEL OF EVIDENCE

III.

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.

Congenital Etiology Is an Independent Risk Factor for Complications in Adolescents Undergoing Corrective Scoliosis Surgery: Comparison of In-hospital Comorbidities Using Nationwide KID's Inpatient Database

BACKGROUND

Congenital scoliosis (CS) is associated with more rigid, complex deformities relative to adolescent idiopathic scoliosis (AIS) which theoretically increases surgical complications. Despite extensive literature studying AIS patients, few studies have been performed on CS patients. The purpose of this study was to evaluate complications associated with spinal fusions for CS and AIS.

METHODS

A retrospective review of the Kid's Inpatient Database (KID) years 2000 to 2009 was performed. Inclusion: patients under 20 years with ICD-9 diagnosis codes for idiopathic scoliosis (IS-without concomitant congenital anomalies) and CS, undergoing spinal fusion from the KID years 2000 to 2009. Two analyses were performed according to age below 10 years and 10 years and above. Univariate analysis described differences in demographics, comorbidities, intraoperative complications, and clinical values between groups. Binary logistic regression controlling for age, sex, race, and invasiveness predicted complications risk in CS (odds ratios; 95% confidence interval).

RESULTS

In total, 25,131 patients included (IS, n=22443; CS, n=2688). For patients under age 10, CS patients underwent 1 level shorter fusions (P<0.001), had fewer comorbidities (P<0.001), and sustained similar complication incidence. In the 10 and over age analysis, CS patients similarly had shorter fusions, but greater comorbidities, and significantly more complications (odds ratio, 1.6; confidence interval, 1.4-1.8).

CONCLUSIONS

CS patients have higher in-hospital complication rates. With more comorbidities, these patients have increased risk of sustaining procedure-related complications such as shock, infection, and Adult Respiratory Distress Syndrome. These data help to counsel patients and their families before spinal fusion.

LEVEL OF EVIDENCE

Level III-retrospective review of a prospectively collected database.

Posterior hemivertebra resection with unilateral instrumented fusion in children less than 10 years old: preliminary results at minimum 5-year follow-up

Background

The main treatment for congenital hemivertebra is posterior hemivertebrectomy with bilateral transpedicular fixation. To date, studies describing posterior unilateral fusion are few, especially in younger children. The modified method by posterior hemivertebrectomy combined with unilateral transpedicular instrumentation and fusion was described. The purpose was to present the clinical and radiological outcome of children less than 10 years treated for congenital scoliosis with posterior hemivertebrectomy and unilateral instrumented fusion.

Methods

A study of 43 consecutive patients through Jan. 2006 to Mar. 2013 for hemivertebrae in children less than 10 years was performed. Patients undergoing hemivertebrectomy and posterior convex short-segment fusion, which had been followed up for at least 60 months, were included. Coronal main curve, kyphosis, T1-S1 height, fused vertebra height, and concave height were measured at preoperation, immediate postoperation, and final follow-up. The outcome and efficacy of the correction provided and growth of the non-fused concave side of the spine was investigated.

Results

The average follow-up period was 73.88 ± 16.77 months. The mean Cobb angle of the coronal curve was improved from 46.1 to 8.1° (correction rate 82.4%). At final follow-up, there was 7.8% loss of correction. The average concave height, fusion segment height, and T1-S1 height were 60.1 ± 19.7 mm, 56.9 ± 22.9 mm, and 326.6 ± 64.5 mm in immediate postoperation, which improved to 73.1 ± 23.7 mm, 71.2 ± 22.0 mm, and 388.7 ± 78.9 mm at the last follow-up. These parameters were significantly different between the immediate postoperation and at final follow-up. The rate of reoperation was 9.3% (4/43), mainly in PJK and curve progression after surgery.

Conclusions

Despite with some complications, posterior hemivertebrectomy and unilateral instrumented fusion are commendable procedures. We concluded that it is a simple, secure, reliable, less-invasive, and well-tolerated technique that can successfully resolve this kind of congenital scoliosis in children.

3D printing for preoperative planning and surgical training: a review

Surgeons typically rely on their past training and experiences as well as visual aids from medical imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) for the planning of surgical processes. Often, due to the anatomical complexity of the surgery site, two dimensional or virtual images are not sufficient to successfully convey the structural details. For such scenarios, a 3D printed model of the patient's anatomy enables personalized preoperative planning. This paper reviews critical aspects of 3D printing for preoperative planning and surgical training, starting with an overview of the process-flow and 3D printing techniques, followed by their applications spanning across multiple organ systems in the human body. State of the art in these technologies are described along with a discussion of current limitations and future opportunities.

One-stage posterior excision of lumbosacral hemivertebrae: Retrospective study of case series and literature review

Lumbosacral hemivertebrae causes unique problems as early trunk decompensation and long compensatory curve above. There are only a few reports on it. This case series is a fair supplement in the literatures.To evaluate the clinical and radiological outcomes of lumbosacral hemivertebrae resection through 1-stage posterior approach.Between 2005 and 2014, a consecutive series of congenital scoliosis due to lumbosacral hemivertebrae underwent hemivertebrae excision through 1-stage posterior only approach. Demographic, operative, radiological, and quality of life data were reviewed.The mean lumbosacral curve was 29 ± 7° preoperatively, 10 ± 3° postoperatively, and 13 ± 5° at the final follow up. The final correction rate was 55 ± 9%. The gravity trunk shift was 11 ± 3 mm preoperatively, 37 ± 12 mm (range, 6-49 mm) postoperatively, 14 ± 9 mm at final follow up. The rib cage shift was 36 ± 12 mm preoperatively, 19 ± 5 mm postoperatively, and 15 ± 4 mm at the final follow up. The mean blood loss was 527 ± 125 mL and the mean surgery time was 336 ± 98 minutes. The mean follow up period was 41 ± 6 months. Two patients underwent transient neurological complications, 2 had wound bad healing, and 1 got wound infection. No pseudoarthrosis and instrumentation failure was observed.One-stage posterior hemivertebrae excision could gain reasonable outcome. It is crucial to completely resect the hemivertebrae and the Y-shaped disc. Bending the rod to appropriate lordosis is helpful to close the convex side. Early surgical intervene is a preferred choice to restore the trunk balance and avoid extensive fusion. The neurological complication rate is high. Convex radiculopathy is often caused by retraction, it could recover at follow up.

Convex Hemiepiphysiodesis: Posterior/anterior in-situ Versus Posterior-only With Pedicle Screw Instrumentation: An Experimental Simulation in Immature Pigs

STUDY DESIGN

Experimental study.

BACKGROUND

Convex growth arrest (CGA) has been commonly used in the treatment of long-sweeping congenital deformities of the immature spine. As there are major drawbacks about the anterior procedure in the conventional CGA method, a new modification has been documented that using only posterior spinal approach with pedicle screw instrumentation. The aim of the study was to compare posterior-only CGA using pedicle screws with combined anterior/posterior in-situ CGA for the findings in histologic, radiologic, and manual palpation examinations in an immature pig model.

METHODS

Twelve 10-weeks old pigs were grouped into 2. In group 1, posterior-only, pedicle screw instrumented CGA was performed on the left side of L1-L4 vertebrae. In group 2, conventional combined posterior and anterior CGA was performed to the left side of L1-L4 vertebrae without instrumentation. All animals were killed twelve weeks after surgery. T11-L5 segments were en-bloc resected and radiologic, histologic, and manual palpation examinations were done.

RESULTS

Marked scoliotic (12.2±2.5 and 9.2±1.3 in group 1 and 2, respectively) and kyphotic (11.2±1.0 degrees for the group 1 and 12±5.2 degrees for the group 2, respectively) deformities were noted in both groups, which were caused by hemiepiphysiodesis effect. Anterior and posterior parts of group 2 and posterior part of group 1 demonstrated fusion in histologic and radiologic analyzes. In anterior part of the group 1, marked narrowing on the disk spaces and thinning of growth plates were noted in radiologicg examination, chondrocyte degeneration, and newly-formed bone trabeculae in disk-space were noted in histological examination. In manual palpation, no motion was detected in group 1 and motion was detected in only one segment of one animal in group 2.

CONCLUSIONS

Anterior growth of the vertebrae can be controlled by application of posterior transpedicular screws and rod. Such an effect can eliminate the need for anterior surgical intervention in convex hemiepiphysiodesis procedures.

CLINICAL RELEVANCE

The instrumented CGA technique provides a satisfactory epiphysiodesis effect both anteriorly and posteriorly, as previously demonstrated by clinical studies.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

Congenital scoliosis treated with posterior vertebral column resection in patients younger than 18 years: longer than 10-year follow-up

OBJECTIVE

There have been no reports on the long-term radiographic outcomes of posterior vertebral column resection (PVCR) in patients with congenital scoliosis. The purpose of this study was to evaluate the surgical outcomes and complications after PVCR and its long-term effects on correcting this deformity in children with congenital scoliosis.

METHODS

The authors retrospectively analyzed the medical records of 45 patients with congenital scoliosis who were younger than 18 years at the time of surgery and who underwent PVCR and fusion with pedicle screw fixation (PSF). The mean age of the patients at the time of surgery was 11.3 years (range 2.4–18.0 years), and the mean length of follow-up was 12.8 years (range 10.1–18.2 years).

RESULTS

The mean Cobb angle of the main curve was 46.5° before PVCR, 13.7° immediately after PVCR, and 17.6° at the last follow-up. For the compensatory cranial curve, PVCR corrected the preoperative Cobb angle of 21.2° to 9.1° postoperatively and maintained it at 10.9° at the last follow-up. For the compensatory caudal curve, the preoperative Cobb angle of 23.8° improved to 7.7° postoperatively and was 9.8° at the last follow-up. The authors noted 22 complications, and the overall incidence of complications was 48.9%.

CONCLUSIONS

Posterior vertebral column resection is an effective procedure for managing congenital scoliosis in patients younger than 18 years. Use of PVCR and fusion with PSF for congenital scoliosis achieved rigid fixation and satisfactory deformity correction that was maintained over the long term. However, the authors note that PVCR is a technically demanding procedure and entails risks for major complications and excessive blood loss.

An initial biomechanical investigation of fusionless anterior tether constructs for controlled scoliosis correction

BACKGROUND CONTEXT

Conservative treatment for adolescent idiopathic scoliosis is often unsuccessful and requires surgical intervention. Theoretically, anterior fusionless surgery can achieve correction as the patient grows to skeletal maturity.

PURPOSE

The objective of the present study was to determine differences in range of motion (ROM) between multiple anterior tether constructs and tensioning techniques. Coronal plane Cobb angles were evaluated.

STUDY DESIGN/SETTING

This is a cadaveric biomechanical study.

METHODS

Cadaveric spines underwent biomechanical testing to investigate two factors relevant to anterior tether reconstruction: (1) effect of fixation at the T4, superior, and T12, inferior, levels (S-I), as opposed to fixation at all T4-T12 continuous levels (Cont.); and (2) tensioning of the tether sequentially (SEQ T) or only at terminal points (T). Reconstructions were conducted at Cont., and ROM and coronal plane Cobb angles were measured. Rigid rods (R) were used as control for the tether. Funding for the present study was provided by Globus Medical, Inc., and three of five authors are employees of Globus Medical, Inc.

RESULTS

Normalized lateral bending ROM for intact was 100(±33)%. The S-I R construct reduced motion to 39(±8)%. Tethering at terminal points resulted in ROM for S-I T and S-I No T of 61(±21)% and 70(±17)%, respectively. Screws placed at every level resulted in motion of 28(±9)% for the Cont. R construct, and a stepwise increase in motion to 44(±15)%, 47(±18)%, and 71(±19)%, respectively, for Cont. SEQ T, Cont. T, and Cont. No T. These relative trends were the same in all loading modes. Average change in overall coronal plane Cobb angle from intact was 4.6(±3.2)° and 9.9(±5.5)° for Cont. T and Cont. SEQ T constructs, respectively.

CONCLUSIONS

Tensioned tether constructs allowed greater ROM than rigid constructs, and no significant difference in ROM was noted between tensioning techniques. Sequential tensioning can produce greater correction with no biomechanical advantage.

Safety and efficacy of instrumented convex growth arrest in treatment of congenital scoliosis

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

Therapeutic level IV study.

Posterior hemivertebra resection and short segment fusion with pedicle screw fixation for congenital scoliosis in children younger than 10 years: greater than 7-year follow-up

STUDY DESIGN

A retrospective study.

OBJECTIVE

To evaluate the surgical outcomes of posterior hemivertebra resection and short segment fusion with segmental pedicle screw fixation in congenital scoliosis in children younger than 10 years.

SUMMARY OF BACKGROUND DATA

This is the first long-term follow-up on surgical outcomes of posterior hemivertebra resection and short segment fusion using segmental pedicle screw fixation in children younger than 10 years with congenital scoliosis.

METHODS

Patients with congenital scoliosis (n = 18) younger than 10 years at the time of the surgery were treated by posterior hemivertebra resection and bilateral pedicle screw fixation. The mean age at the time of surgery was 6.6 years (range, 2.6-9.8 yr). They were retrospectively studied with a mean follow-up of 11.4 years (range, 7.1-17.3 yr).

RESULTS

The mean Cobb angle of the main curve was 34.4° before surgery, 8.6° after surgery, and 12.9° at last follow-up. In the compensatory cranial curve, the preoperative Cobb angle of 14.5° was corrected to 5.9° postoperatively and was 8.4° at last follow-up. In the compensatory caudal curve, the preoperative Cobb angle of 17.4° improved to 4° postoperatively and 6.6° at last follow-up. There were no crankshaft phenomena and no clinical and radiographical features suggestive of spinal stenosis during follow-up. There were no major vascular or neurological complications related to the pedicle screws.

CONCLUSION

Posterior hemivertebra resection after pedicle screw fixation in congenital scoliosis is a safe and effective procedure that can achieve rigid fixation and deformity correction and restore spinal balance. This study showed that early posterior hemivertebra resection of congenital scoliosis before structural changes occur above or below can reduce fusion length, prevent curve progression, and effectively achieve a more satisfactory correction without hazardous iatrogenic spinal stenosis, crankshaft phenomena, or neurological complications.

LEVEL OF EVIDENCE

3.

Convex short segment instrumentation and hemi-chevron osteotomies for Putti type 1 thoracic hemivertebrae: a simple treatment option for patients under 5 years old

STUDY DESIGN

A case series depicting the results of a novel surgical technique.

OBJECTIVE

To prove that a minimally invasive surgical technique can effectively control and even correct congenital scoliosis caused by a fully segmented hemivertebra.

SUMMARY OF BACKGROUND DATA

Congenital hemivertebrae have been treated by anterior and posterior growth arrest with/without fusion, anterior and posterior hemivertebrectomy, transpedicular hemivertebra excision, and transpedicular hemiepiphysiodesis. These approaches are complex and require experience. There is a need for a simple treatment method to treat these deformities.

METHODS

Twelve patients under 5 years of age with Putti type1 hemivertebrae were treated by posterior convex short segment instrumentation, partial chevron osteotomies, and fusion. Scoliosis, segmental scoliosis, kyphosis, segmental kyphosis, trunk shift were measured both preoperatively and postoperatively.

RESULTS

The mean correction of the segmental curve was 6 degrees (21%) which was maintained at the latest follow-up. The average final correction of the main curve was 23%. The trunk shift was 1.8 cm (range, 1-3 cm) preoperative and 1.4 cm (range, 0-2.5 cm) at the latest follow-up. The segmental angle of kyphosis averaged 11 degrees (range, -12 to 20 degrees) preoperative, and 14 degrees (range, 0-29 degrees) at the latest follow-up assessment. The values of the total thoracic kyphosis (T2-T12) were 29.5 degrees (range, 10-46 degrees) preoperative, 31 degrees (range, 10-44 degrees) postoperative, and 32 degrees (range, 16-45 degrees) at the last follow-up resulting in a mean improvement of 2 degrees. This improvement continued at the latest follow-up with a mean increase of 3 degrees.

CONCLUSIONS

Transpedicular instrumentation is ideal for early correction in young children. The new posterior approach is much less invasive than the combined approaches or other posterior vertebrectomies and is well tolerated even in very young patients. The fusion segment is kept short. The deformities seem to stop progressing and this can avoid development of severe local deformities and secondary curves.

Ossifications after vertical expandable prosthetic titanium rib treatment in children with thoracic insufficiency syndrome and scoliosis

STUDY DESIGN

Retrospective analysis of 1328 spinal radiographs of 57 patients after vertical expandable prosthetic titanium rib (VEPTR) implantation with an average follow-up of 30 months.

OBJECTIVE

To evaluate the incidence, time of onset, as well as the underlying factors influencing the occurrence of ossifications in children treated with VEPTR.

SUMMARY OF BACKGROUND DATA

Spontaneous spinal fusions and ossifications are well known in children treated with spinal implants. In theory, children with spinal deformity and VEPTR implantation are less likely to develop these complications because of either little or no implant contact to the spine.

METHODS

Fifty-seven patients had a primary VEPTR implantation due to spinal deformity and thoracic insufficiency syndrome and repeated lengthening procedures. The mean age at the time of primary surgery was 7.7 years, the mean duration of follow-up was 29.8 months, and the mean number of operations was 5.9. A total of 1328 spinal radiographs were analyzed with respect to the occurrence and growth of ossifications, implant migration, and other complications.

RESULTS

Overall, 24% of the patients (n = 13) had ossifications, which affected in 92% the main load sharing VEPTR implant. The fusions involved in 54% of cases the lumbar spine and in each 23% the ribs and the iliac crest. Ossifications developed in 11% of children within the first year of treatment and increased by about the same rate per annum. After 53 months, 48% of the radiographs showed some ossifications. There was a significant correlation to the stiffness of the deformity and the number of surgical procedures.

CONCLUSION

Contrary to previous assumptions, it was shown that in children treated with the VEPTR system, 48% of children showed ossifications after 53 months. Ossifications were observed significantly more often in children with stiff deformities and after multiple surgical procedures. It is a much more common problem than previously thought.

LEVEL OF EVIDENCE

3.

Convex instrumented hemiepiphysiodesis with concave distraction: a preliminary report

BACKGROUND

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.

QUESTIONS/PURPOSES

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.

PATIENTS AND METHODS

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).

RESULTS

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.

CONCLUSIONS

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 OF EVIDENCE

Level IV, therapeutic study. See the guidelines online for a complete description of level of evidence.

Computer-assisted hemivertebral resection for congenital spinal deformity

BACKGROUND

No studies have reported on osteotomies utilizing a navigation system in congenital scoliosis surgery. This study aimed to evaluate the surgical outcomes of eight patients with congenital scoliosis or kyphoscoliosis due to hemivertebrae treated by computer-assisted hemivertebral resection using only a posterior approach.

METHODS

Eight consecutive patients (two scoliotics and six kyphoscoliotics) managed by computer-assisted hemivertebral resection using only a posterior approach with transpedicular instrumentation were investigated retrospectively. A CT-based navigation system was used to confirm the positions of the vertebra, spinal cord and aorta in real-time when we inserted a pedicle screw and conducted the osteotomy. The mean patient age at surgery was 18 years (range 11-41 years). The mean follow-up was 46 months (range 18-84 months).

RESULTS

Before surgery, the mean kyphotic curve was 55.8° (range 26-83°), and the mean scoliotic curve was 50.0° (range 36-62°). At the final follow-up period, the curves averaged 23.2° (range 15-40°) and 31.6° (range 21-44°), respectively, yielding kyphotic angle corrections of 32.7° (range 11-58°) and Cobb angle correction rates of 36.8% (range 24.1-48.3%). A total of 72 pedicle screws were inserted with the navigation system, and two screws revealed a perforating pedicle. No neurovascular complications occurred. The perforation rate was 2.8%.

CONCLUSIONS

Hemivertebral resection via a single posterior approach is less invasive than combined anterior and posterior approaches; however, this procedure increases the risk of spinal cord and vascular injuries. Computer-assisted hemivertebral resection enables safe and accurate performance of a hemivertebral resection via a single posterior approach.

Preoperative medical and surgical planning for early onset scoliosis

STUDY DESIGN

A review of current medical and surgical preoperative planning knowledge and protocols for children with early-onset scoliosis (EOS; onset less than 5 years of age).

OBJECTIVE

To describe the preoperative planning process to undertake safe and effective treatment for the EOS patient.

SUMMARY OF BACKGROUND DATA

Children with EOS present with a myriad of medical and orthopedic conditions associated with their specific diagnosis, and frequently require intensive preoperative evaluation and nutritional, pulmonary, and other support to prepare them for safe and effective treatment of the spinal/chest wall deformity. Such patients are among the most difficult and complex to treat effectively.

METHODS

A literature review of known conditions associated with EOS, and a summary of current surgical techniques to maintain deformity control while promoting spine and thoracic growth, was undertaken. Current recommendations for preoperative support and postoperative management of these complex patients are summarized, drawn from the experiences of the author and members of study groups focusing on EOS.

RESULTS

Preoperative assessment of respiratory function, potential for respiratory failure, and determination of objective criteria to indicate surgical management (deformity progression, lack of growth of spine and/or thoracic volume, lack of weight gain) are weighed against the potential for development of thoracic insufficiency syndrome. Magnetic resonance imaging evaluation for neuraxis abnormalities is considered on the basis of diagnosis. Nutritional status, osteopenia, and airway management are evaluated to minimize postoperative complications. Current general recommendations for implants and constructs for specific deformities are reviewed.

CONCLUSION

Thorough preoperative evaluation of EOS patients provides the surgeon with the knowledge to produce a sound surgical plan for this difficult and complex to treat patient population.

Congenital thoracolumbar spine deformities

Congenital thoracolumbar spinal deformities are a common and frequent reason for referral to spine surgeons. Neurosurgeons also treat many neurological diagnoses which may result in a progressive spinal deformity, such as scoliosis. Here we review a variety of congenital anomalies and address the maldevelopments associated with each, as well as the appropriate evaluation of such patients including nonoperative and operative approaches. Advances in the field of spinal deformity correction now allow us to better treat individuals with these types of deformities. It is important for the practicing neurosurgeon to be knowledgeable of surgical and nonsurgical treatments of patients with congenital thoracolumbar spinal deformities in order to better understand which patients will ultimately progress and necessitate surgical treatment.

Treatment of congenital scoliosis with single-level hemivertebrae

INTRODUCTION

The natural history of congenital scoliosis with hemivertebrae is unpredictable and the management is also controversial.

MATERIALS AND METHODS

Between 1986 and 2004, 22 patients (eight male and fourteen female, mean 19.3 years old) with single-level hemivertebrae related congenital scoliosis underwent non-operative or operative treatment at our institution with an average follow-up period of 8.8 years.

RESULTS

Only a 5 degrees curve progression was noted in upper thoracic hemivertebrae after followed up 6 years. By one stage combined anterior hemivertebrae excision, posterior instrumentation, and arthrodesis, up to 61% curve correction can be achieved. Posterior instrumentation, correction and arthrodesis showed a 25% correction. The result of pain relief is promising in skeletal-matured patients.

CONCLUSIONS

Surgical instrumentation, correction and arthrodesis showed good results. The optimal treatment of choice may differed from one to the other.

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.

Hemivertebra resection for the treatment of congenital lumbarspinal scoliosis with lateral-posterior approach

STUDY DESIGN

A retrospective review of patient records was conducted.

OBJECTIVE

To evaluate the results of a lumbar hemivertebra resection and short-segment fusion through a lateral-posterior approach.

SUMMARY OF BACKGROUND DATA

Few reports have been reported describing a procedure consisting of one-stage lateral-posterior lumbar hemivertebra resection and correction of the deformity by segmental anterior instrumentation to date.

METHODS

From 1998 to 2006, a consecutive series of twenty-four patients with congenital scoliosis or kyphoscoliosis due to a lumbar hemivertebra were managed by resection of the hemivertebra through a lateral-posterior approach and with the use of a short anterior convex-side fusion. RESULTS.: The mean age at the time of surgery was 9.4 years (range, 6 years and 8 months-16 years and 9 months). The mean follow-up period was 43 months (5-94). There was a mean improvement of 61.5% in the segmental scoliosis curve from a mean angle of 45.2 degrees before surgery to 17.4 degrees at the time of the latest follow-up assessment, and a mean improvement of 60.9% in the total main scoliosis curve from 47.6 degrees to 18.6 degrees at the same periods. The mean final lordosis was within normal values. There were no major complications and no neurologic damage.

CONCLUSION

Excision of a lumbar hemivertebra through lateral-posterior approach is safe and provides stable correction when combined with a short-segment fusion.

Evidence basis for management of spine and chest wall deformities in children

STUDY DESIGN

: Review of relevant studies, including levels of evidence.

OBJECTIVE

: To review research on growth of the spine and chest wall and treatment of deformities. To place this knowledge in context of evidence-based assessment.

SUMMARY OF BACKGROUND DATA

: Knowledge of the growth of the spine, chest wall, and lung in the normal and deformity states has evolved among independent specialties over the past 60 years. Interest in the interrelationship has blossomed as more tools for assessment and treatment have developed. Spine-based and chest wall-based treatment options now exist, as well as options of resection versus gradual distraction.

METHODS

: Peer-reviewed research published on the growth of the spine, lung, chest wall, and treatment of their deformities was reviewed. Treatment methods and outcomes were compared. Ranking of the levels of evidence was performed where possible.

RESULTS

: Most studies of these topics are Level III and IV studies, consisting of case-control studies and case series. This limitation arises because of the rarity and heterogeneity of the disorders affecting the growing spine and chest wall. The natural history of most types of spinal/chest wall deformities is not known with accuracy. Some experimental evidence informs the treatments which involve modulation of the growth of the spine. However, accurate models of the deformities themselves are lacking. Improvements in imaging and measurement offer options for more accurate patient comparison.

CONCLUSION

: The natural history and results of treatment of deformities of the spine and chest wall offer much opportunity for further evidence-based research.

Transpedicular hemiepiphysiodesis and posterior instrumentation as a treatment for congenital scoliosis

Anterior and posterior hemiepiphysiodesis using a transpedicular approach is an effective alternative treatment when compared with the traditional convex hemiepiphysiodesis or hemivertebrae excision. No study has reported the results of instrumentation with transpedicular hemiepiphysiodesis. Our study was a retrospective radiographic evaluation to assess the efficacy of transpedicular convex hemiepiphysiodesis with short segment instrumented posterior spinal fusion for congenital scoliosis. Ten hemivertebrae in 9 patients were evaluated. The average patient age was 10.5 years (range, 2.9-14.5 years). The average follow-up was 29.7 months. Cobb angles were recorded for the instrumented segment (segmental main curve) and the global or entire curve (total main curve). These values were compared preoperatively, postoperatively, and at 2-year follow-up. The average total main curve improved in 6 of 10 curves, from 35.0 to 29.6 degrees (15.4%). The average segmental main curve improved in 8 of 10 curves, from 30.0 to 21.5 degrees (28.3%). Seven of 10 curves demonstrated either no progression or improvement at the average 2-year follow-up. Two curves in older patients (greater than 9 years, 10 months) progressed until a comprehensive posterior spinal fusion was required. Multiple surgical techniques have been developed to provide treatment for progressive congenital scoliosis. Transpedicular hemiepiphysiodesis with a short segment instrumented posterior spinal fusion is a safe and effective treatment method to halt the progression of congenital scoliosis due to a hemivertebra in patients who are skeletally immature.

Safety and efficacy of posterior instrumentation for patients with congenital scoliosis and spinal dysraphism

OBJECTIVE

Instrumentation and correction of severe congenital scoliosis, particularly in patients with spinal dysraphism, has been reported to cause a high potential rate of neurological compromise after instrumentation. The aim of this study was to evaluate the safety and efficacy of posterior instrumentation and correction of congenital scoliosis with accompanying spinal dysraphism.

LEVEL OF EVIDENCE

Level IV therapeutic studies.

METHODS

Retrospective x-ray measurements to analyze the efficacy and the evaluation of hospital charts to document the intraoperative and postoperative complications were performed for a consecutive patient series. Scoliosis Research Society-22 questionnaire was used to analyze the health-related quality of life.

RESULTS

Twenty-two patients (18 girls and 4 boys) formed the basis of the study. The average age was 12 years (range, 7-18 years) and the average follow-up period was 3.2 years (range, 2-10 years). The types of spinal dysraphism were diastematomyelia in 20 patients and syringomyelia with tethered cord in 2 patients. Twelve patients had previous surgery and 3 patients had simultaneous surgeries for spinal dysraphism. Posterior instrumentation with/without anterior release and fusion was performed in all patients. Major curve was corrected from an average of 71 degrees to 40 degrees (correction rate, 43.6%). The compensatory curve was corrected from an average of 47 degrees to 25 degrees (correction rate, 46.8%). The average loss of correction at final follow-up was 2.2 degrees for major curve and 3.5 degrees for the compensatory curve. The average scores for the 5 domains of Scoliosis Research Society-22 questionnaire were 3.5 for function, 3.9 for pain, 3.5 for self-image, 3.6 for mental health, 3.9 for satisfaction, and 3.6 for total. Neurological monitoring was conducted by using the wake-up test in all patients. The overall complication rate was 31%, including neurological compromise in 2 patients (9%).

CONCLUSIONS

Spinal instrumentation was effective for the control of deformity with a relatively higher rate of complications. However, with respect to high complication rate, the ideal solution for managing the congenital cases is still to prevent the progression of the curve with early intervention by using the optimal surgical approach for that particular patient.

Segmental vessel sparing during convex growth arrest surgery--a modified technique

BACKGROUND CONTEXT

Further evidence of the importance of segmental vessel ligation in the development of neurological complications has been recently published. The more levels the ligation encompasses, the higher the risk of spinal cord damage. Therefore, caution should be taken when several segmental arteries are to be ligated in the clinical setting.

PURPOSE

To prevent ligation of segmental vessels during convex growth arrest surgery and thus decrease the risk of spinal cord ischemia and neurological injury.

STUDY DESIGN

A report of a modified technique of convex growth arrest surgery used in two consecutive patients in our unit.

METHODS

In two consecutive patients the segmental vessels were mobilized, elevated, and protected by using surgical slings. The rib graft was then slid beneath the elevated vessels into the prepared vertebral body channel and punched into place. The pleura then closed over the rib graft and spared vessels.

RESULTS

Three of the five segmental vessels in the first patient were spared. All five segmental vessels were spared in the second patient. No neurological complications occurred.

CONCLUSION

We report a straightforward technique, which obviates the need for segmental vessel ligation, and therefore decreases the risk of neurological injury in an already high-risk group.

Thoracolumbar hemivertebrae resection by double approach in a single procedure: long-term follow-up

STUDY DESIGN

Retrospective review of patients records with clinical and radiographic assessment.

OBJECTIVE

To evaluate the long-term result of thoracolumbar hemivertebrae resection using a double approach in a single procedure.

SUMMARY OF BACKGROUND DATA

Thoracolumbar hemivertebrae resection by a combined posterior and anterior approach has been previously described, but this is the largest series of hemivertebrae reported.

METHODS

From 1987 to 2003, a consecutive series of 34 congenital scoliosis or kyphoscoliosis due to thoracolumbar hemivertebrae were managed by hemivertebra resection using a combined posterior and anterior approach and short anterior and posterior convex fusion in the same day/same anesthesia.

RESULTS

The mean age at surgery was 3.5 years. The mean follow-up period was 6.0 years. There was a mean improvement of 69.3% in the segmental curve from a mean angle of 34.8 degrees before surgery to 10.7 degrees at the latest follow-up assessment. The global scoliosis curve improved of 33.4% from 40.4 degrees to 26.9 degrees, respectively. Trunk shift was significantly improved. The mean final kyphosis was within normal values.

CONCLUSIONS

This procedure is safe and offers a persistent correction with a short segment fusion. Surgery should be performed as early as possible to avert severe local deformities and prevent secondary structural deformities in order to avoid extensive fusions.

Lumbosacral hemivertebrae resection by combined approach: medium- and long-term follow-up

STUDY DESIGN

Retrospective review of patients records with clinical and radiographic assessment.

OBJECTIVES

To evaluate the long-term result of lumbosacral hemivertebrae resection using a combined approach.

SUMMARY OF BACKGROUND DATA

Lumbosacral hemivertebrae resection by a combined posterior and anterior approach have been previously described, but only one study is concerning such a large series of hemivertebrae.

METHODS

From 1980 to 2001, a consecutive series of 17 congenital scolioses due to lumbosacral hemivertebrae were managed by hemivertebrae resection using a combined approach and short anterior and posterior convex fusion.

RESULTS

The mean age at surgery was 4.9 years. The mean follow-up period was 7.6 years. One postoperative complication was encountered: a patient had motor deficit and recovery was incomplete. The mean segmental scoliosis curve was 27.5 degrees before surgery, 10.7 degrees after surgery, and 8.9 degrees at the latest follow-up assessment. This represents a mean improvement of 61.1% after surgery and of 67.6% at the latest follow-up. The total main scoliosis curve improved from 28.4 degrees to 12.7 degrees and 11.4 degrees , respectively. It represents a mean improvement of 55.3% and 59.9%, respectively. The mean final lordosis was within normal values.

CONCLUSIONS

This procedure offers a persistent correction with a short-segment fusion. The early surgery is able to avert severe local deformities and prevent secondary structural deformities in order to avoid extensive fusions.

Résultats à maturité osseuse après résection d’hémivertèbres par double abord

PURPOSE OF THE STUDY

The natural history of congenital scoliosis or kypho-scoliosis resulting from a hemivertebra is well documented. The spinal deformation generally worsens in children with a free or semi-segmented hemivertebra situated in the thoraco-lumbar, lumbar or lumbosacral region.

MATERIAL AND METHODS

From 1982 to 1997, fifteen pediatric patients with 15 hemivertebrae causing progressive scoliosis or kypho-scolisosis underwent hemivertebral resection via a double posterior and anterior approach associated with convex fusion. Mean age at surgery was 4.4 years. The fifteen patients were reviewed at bone maturity (Risser 4 or 5) to assess outcome.

RESULTS

Genitourinary tract anomalies were associated in five of the 15 patients and intrathecal anomalies in two. Mean follow-up was 12.1 years. Segmental scoliosis was 30.2 degrees preoperatively, 12.3 degrees postoperatively and 8.9 degrees at last follow-up. The values for total scoliosis were 30.5 degrees, 12.3 degrees and 12.6 degrees respectively. This was a 70.5% improvement at last follow-up for segmental scoliosis and 58.7% for total scoliosis. The real trunk imbalance improved from 31% preoperatively to 9% at last follow-up. All these differences were significant.

DISCUSSION

The main objective of surgical treatment for congenital scoliosis due to hemivertebra is to prevent the development of severe deformation which would necessitate a dangerous and difficult procedure to achieve correction. Resection of the hemivertebra via a double approach is the ideal method for early correction. The procedure not only corrects the spinal deformation but also prevents later deterioration. Correction should be performed as early as possible. The result is sustained over time if there is no other associated spinal anomaly. The procedure is safe and the technique well controlled in experimented hands. Patients need to wear a corset for only six months after resection of the hemivertebra.

The vertical expandable prosthetic titanium rib implant for the treatment of thoracic insufficiency syndrome associated with congenital and neuromuscular scoliosis in young children

Expansion thoracoplasty and vertical expandable prosthetic titanium rib (VEPTR; Synthes Spine Co., West Chester, Pennsylvania, USA) implantation is a new method for the treatment of thoracic insufficiency syndrome and congenital spinal deformity in children. The longitudinal rib implant expands the thorax and indirectly corrects spinal deformity, thus allowing spinal, thoracic and probably lung growth. VEPTR has been used since 1989 in San Antonio, USA, and was introduced to Europe in 2002. This paper describes the preliminary experience with the European patients. Fifteen children with progressive scoliosis had a VEPTR implantation at a mean age of 6 years (11 months to 12 years). Nine children had thoracic insufficiency syndrome due to unilateral unsegmented bars (n = 4), absent ribs (n = 1), hemivertebrae (n = 2) or bilateral fused ribs (n = 2). Six children had severe thoracolumbar scoliosis and pelvic obliquity due to neuromuscular scoliosis. After VEPTR implantation, families and patients reported improvement of the thoracic insufficiency syndrome and better sitting abilities in the neuromuscular patients, as well as radical cosmetic improvement. There were three complications (skin breakage, lumbar hook displacement, rib fracture) after performing fifteen primary VEPTR implantations and 13 expansion surgeries in eight patients. Our experience suggests that expansion thoracoplasty and VEPTR implantation is a safe and efficient method for the treatment of thoracic insufficiency syndrome in young children with severe scoliosis.

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.

Endoscopic mechanical spinal hemiepiphysiodesis modifies spine growth

STUDY DESIGN

An in vivo porcine model of progressive scoliosis as an inverse analog of a proposed method of early surgical treatment.

OBJECTIVES

To test the hypothesis that scoliotic curvatures may be repeatedly created using anatomically based vertebral staples and thoracoscopic surgical procedures.

SUMMARY OF BACKGROUND DATA

Staple hemiepiphysiodesis is an established method for treating knee deformities. Similar procedures have so far failed to arrest or correct deformities of the spine. While experimental studies continue to suggest that spine growth is modifiable, no prior clinically translatable method has been shown to clearly and consistently alter vertebral growth.

METHODS

Custom spine staples were implanted into midthoracic vertebrae of seven skeletally immature normal pigs. Each staple spanned an intervertebral disc and two growth plates and was fixed to adjacent vertebrae with screws. The animals were anesthetized biweekly for radiography during the 8-week study period. Final radiographs were taken after spine harvest. Initial and final postoperative Cobb angles were compared statistically.

RESULTS

Five animals completed the protocol with a weight increase of 142% in 8 weeks. Coronal plane curvatures increased significantly with time, from 0.8 (+/-1.8) to 22.4 (+/-2.8; P = 0.0001). On average, sagittal plane curvatures did not increase with time.

CONCLUSIONS

Spinal hemiepiphysiodesis using an anatomically based implant and minimally invasive procedures repeatedly induced spine curvature in a normal porcine model. These techniques may slow, and perhaps even correct, early progressive spine deformity without long rod instrumentation or fusion.

Hemivertebra excision in children via simultaneous anterior and posterior exposures

This study evaluates the effectiveness of hemivertebra excision in children via simultaneous anterior and posterior operative exposures. This study was a retrospective review of patients treated with this technique over a 5-year period with minimum 2-year follow-up. Eighteen patients were studied, all of whom had undergone hemivertebra excision and deformity correction using unilateral compression instrumentation. The average age of the patients at the time of operation was 3 years 2 months and the average preoperative coronal curve measured 40 degrees. There were no neurologic complications. At an average follow-up of 35 months all patients had obtained bony fusion; the average coronal curve measured 11 degrees for an average percentage correction of 71%. Hemivertebra excision by simultaneous exposure is an effective and safe way of managing congenital hemivertebra, and the correction is similar to staged anterior-posterior procedures or posterior-only procedures.

[Treatment of congenital scoliosis with the vertical expandable prosthetic titanium rib implant]

Children with congenital thoracic scoliosis associated with fused ribs and unilateral unsegmented bars adjacent to convex hemivertebrae will invariably have curve progression without treatment. It is assumed that the unilateral unsegmented bars do not grow and therefore early spinal fusion has been performed in the past with consecutive short thoracic spines and loss of lung volume. A new surgical technique is based on an indirect deformity correction and enlargement of the thorax via a longitudinal implant, the vertical expandable prosthetic titanium rib (VEPTR). The length of the thoracic spine after VEPTR implantation was analyzed in 21 children with an average follow-up of 4.2 years. Eighteen children did not have any prior surgery while three had already undergone spinal fusion. Using a 3-D analysis of computed tomography, a significant growth of the concave (7.9 mm/7.1% increase per year) and convex (8.3 mm/6.4%) side of the thoracic spine was found with no significant difference between sides. Unilateral unsegmented bars showed significant growth as well. Contrary to common knowledge, we were able to demonstrate the growth of the concave side of the thoracic spine and of the unilateral unsegmented bars after expansion thoracoplasty and VEPTR implantation.

The safety and efficacy of spinal instrumentation in children with congenital spine deformities

STUDY DESIGN

A retrospective radiographic and chart review of patients who underwent operative treatment with the use of reduced size spinal instrumentation for congenital spine deformities

OBJECTIVE

To assess the safety and efficacy of spinal instrumentation in young patients who were operated on for a congenital spine deformity.

SUMMARY OF BACKGROUND DATA

The use of spinal instrumentation has been shown to improve curve correction and arthrodesis rates in spinal deformity surgery. The advent of reduced-size implants has allowed surgeons to expand the use of instrumentation in pediatric patients. The use of reduced-size spinal instrumentation in children with congenital spine deformities has not been well documented.

METHODS

We retrospectively investigated the use of spinal instrumentation in 40 patients younger than 8 years with a congenital spine deformity. The review of radiographs and medical records was performed to assess the complications associated with instrumentation, the curve correction, and the arthrodesis rate in this patient population.

RESULTS

The complications associated with the use of instrumentation in this group of patients were infrequent. Curve correction was excellent, and the sagittal profile was maintained in all patients at an average follow-up of greater than 3 years. All patients obtained a solid arthrodesis.

CONCLUSIONS

The use of reduced-size spinal instrumentation in young patients is safe and efficacious. Curve correction, length of immobilization, and fusion rate are improved compared to similar patients in the literature treated without instrumentation.

Congenital scoliosis

Congenital scoliosis is caused by early embryologic errors in vertebral column formation. Defining the deformity, predicting the natural history, and applying the correct treatment can help ensure successful management. Most congenital spine anomalies can be classified, and many have a predictable natural history. Because the deformities are associated with other organ system anomalies in more than half of patients, the surgeon should look for cardiac, auditory, genitourinary, and renal anomalies. Intraspinal abnormalities are present in approximately one third of patients with congenital spine deformities. Curve progression is best documented by measuring identical landmarks on sequential radiographs. Magnetic resonance imaging is warranted when curve progression is established or when surgical intervention is planned. Management of progressive deformity is generally by early in situ fusion because orthotic treatment is rarely appropriate. Other surgical techniques include combined anterior and posterior epiphysiodesis, hemivertebra resection, and reconstructive osteotomies.

The course of sagittal plane abnormality in the patients with congenital scoliosis managed with convex growth arrest

SUMMARY OF BACKGROUND DATA

Patient age; localization, length, and magnitude of the curve; and sagittal plane alignment are reported to be the major determinants in the selection of patients for convex growth arrest. Although the existence of sagittal plane abnormality (kyphosis or lordosis) is accepted as a contraindication for convex growth arrest, this issue has not been discussed in detail.

OBJECTIVES

The purposes of this study are to investigate the effect of sagittal plane abnormality on the control of coronal plane deformity and to evaluate the course of sagittal plane abnormality of the patients with congenital scoliosis who were satisfactorily managed with convex growth arrest.

STUDY DESIGN

Retrospective analysis.

METHODS

Inclusion criteria are: 1) a diagnosis of congenital scoliosis in a patient younger than 6 years of age, 2) treatment with convex growth arrest, 3) follow up for more than 2 years, 4) stabilized or improved coronal plane deformity, and 5) abnormal sagittal plane alignment within the scoliotic segment before surgery. The patients were evaluated with anteroposterior and lateral radiographs, and segmental measurements were compared according to the normal of their corresponding age.

RESULTS

A total of 38 patients with congenital scoliosis treated with convex growth arrest were reviewed. Among 13 patients with segmental sagittal plane deformity, 2 were excluded because of insufficient control of the scoliosis. Eleven patients (8 girls, 3 boys) with a mean age of 35 months (range 6-72 months) and mean follow-up of 40 months (range 24-76 months) fulfilled these criteria. The coronal plane deformities were 58 degrees (range 36 degrees-105 degrees) before surgery and 52 degrees (13 degrees-107 degrees) at the final follow-up. While six of the curves improved, the remaining ones stabilized. Sagittal segmental alignments within the scoliotic segments were hyperkyphotic in 9 patients and hypokyphotic in 1 and lordotic in 1. At the end of the follow-up, sagittal Cobb angle of the abnormal segments remained stable in 7 patients and deteriorated in 4. None of the 4 patients required any reconstructive spine procedure for kyphosis during follow-up.

CONCLUSION

Sagittal segmental abnormality does not have a negative effect on the control of scoliosis in the majority of the patients (11 of 13). If the coronal curve stabilizes or improves, then sagittal segmental abnormality could also be stabilized (in 7 of 11 patients).

Pediatric spinal deformities

Pediatric spinal deformity results from multiple conditions including congenital anomalies, neuromuscular disorders, skeletal dysplasia, and developmental disorders (idiopathic). Pediatric spinal deformities can be progressive and cause pulmonary compromise, neurological deficits, and cardiovascular compromise. The classification and treatment of these disorders have evolved since surgical treatment was popularized when Harrington distraction instrumentation was introduced.

The advent of anterior-spine instrumentation systems has challenged the concepts of length of fusion needed to arrest curvature progression. Segmental fixation revolutionized the surgical treatment of these deformities. More recently, pedicle screw–augmented segmental fixation has been introduced and promises once again to shift the standard of surgical therapy. Recent advances in thoracoscopic surgery have made this technique applicable to scoliosis surgery.

Not only has surgical treatment progressed but also the classification of different forms of pediatric deformity continues to evolve. Recently, Lenke and associates proposed a new classification for adolescent idiopathic scoliosis. This classification attempts to address some of the shortcomings of the King classification system.

In this article the authors review the literature on pediatric spinal deformities and highlight recent insights into classification, treatment, and surgery-related complications.

Ten-year follow-up study of lower thoracic hemivertebrae treated by convex fusion and concave distraction

STUDY DESIGN

A retrospective review of patient records with recent clinical and radiologic assessment was conducted.

OBJECTIVE

To evaluate the long-term results of fully segmented hemivertebrae treated by convex fusion combined with instrumented concave subcutaneous distraction.

SUMMARY OF BACKGROUND DATA

Convex fusion has been described for the treatment of hemivertebrae in children, whereas distraction without fusion has been shown to enhance spinal growth. No long-term follow-up studies have combined these two methods.

METHODS

Between 1986 and 1994, six consecutive patients (5 males and 1 female) with hemivertebrae located at T11 or T12 underwent convex anterior and posterior fusion as well as concave subcutaneous distraction without fusion.

RESULTS

The mean age at surgery was 3.4 years. The mean follow-up period was 10.8 years (range, 8-14 years). There was a mean improvement of 41% in the coronal deformity, from a mean angle of 49 degrees before surgery to 29 degrees at the latest follow-up assessment. In four of the cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction. The kyphosis improved in three cases, remained unchanged in one case, and deteriorated in two cases. In these two cases, an adjacent wedge vertebra contributed to the kyphotic deformity.

CONCLUSIONS

Although growth-mediated correction was seen in only two cases, this procedure could be recommended for children with severe deformities and decompensation in the lower thoracic spine. It is safer than hemivertebra excision, with less risk of spinal cord injury. The concave distraction produces immediate improvement in the coronal balance, such that there is no need to wait for uncertain growth-mediated correction in patients who undergo convex fusion only.

Long-term results from in situ fusion for congenital vertebral deformity

STUDY DESIGN

Retrospective review of long-term outcome of fusion in situ for congenital vertebral anomaly with particular emphasis on cosmesis and the incidence of reoperation.

OBJECTIVE

Examination of the success rate of this procedure and of risk factors for failure.

BACKGROUND

Fusion in situ is the accepted prophylactic treatment to prevent deformity in congenital vertebral anomalies that have a high risk of progression or have been shown to be deteriorating.

METHODS

Records of patients who were at least 15 years of age at last examination were reviewed retrospectively. Consideration was given to cosmetic outcome and to the incidence of reoperation.

RESULTS

There were 43 patients in this category, 19 boys and 24 girls, who were at least 15 years of age when last seen. Reoperation had been performed in 11 cases (25.6%). The main finding was that, although the Cobb angle of the fused segment of spine remained constant after fusion, a curve sometimes developed in the whole spine, sometimes (but by no means always) centered on that fused segment. Cosmetic deformity continued to progress in a number of cases.

CONCLUSIONS

Localized fusion, whether posterior alone or anterior and posterior combined, was effective in preventing progression of the Cobb angle of the congenitally malformed area but did not control the overall deformity that developed or progressed with growth. Current concepts of the pathomechanism of deformity do not adequately explain the observations, and a more biologic approach is suggested.

Single-stage excision of hemivertebrae via the posterior approach alone for congenital spine deformity: follow-up period longer than ten years

STUDY DESIGN

Evaluation of the long-term results for single fully segmented hemivertebrae were subjected to single-stage excision via posterior approach alone.

OBJECTIVES

To describe the long-term results of this procedure.

SUMMARY OF BACKGROUND DATA

In the case of congenital spinal deformity caused by a single, full hemivertebra, excision of the hemivertebra is ideal for obtaining a good correction percentage even in short segments. Recently, single-stage excision of a hemivertebra using a combined anterior and posterior approach has been reported.

METHODS

Five patients with a hemivertebra underwent surgery. The hemivertebra involved the thoracolumbar region in three cases and the lumbosacral region in two cases. After removal of a lamina of the hemivertebra, the body of the hemivertebra was visualized easily because the spinal cord had deviated to the concave side of the curve. The vertebral body, along with its cranial and caudal discs, was curetted with this approach. Thereafter, bone chips were grafted into the defect created by vertebrectomy. The results of this surgical procedure, especially those observed during long-term follow-up evaluation, were investigated.

RESULTS

For patients with a thoracolumbar hemivertebra, scoliosis improved from 49 degrees +/- 6 degrees to 22.3 degrees +/- 3.5 degrees, for a 54.3% correction. The correction ratio for kyphosis was 67.4%. Over an average 12.8-year follow up period, loss of scoliotic curvature correction was only 3.7 degrees. In contrast, the hemivertebral correction ratio for patients with a lumbosacral hemivertebra remained 32.5% because of difficulty using internal fixation associated with patient age. At the most recent follow-up assessment, one patient exhibited deterioration of coronal spinal balance.

CONCLUSION

The described procedure was less invasive because it avoided an anterior approach, yet it yielded satisfactory long-term results for thoracolumbar hemivertebrae.

Transpedicular eggshell osteotomies for congenital scoliosis using frameless stereotactic guidance

STUDY DESIGN

Three cases of multiplanar congenital scoliosis corrected by a transpedicular eggshell osteotomy using frameless stereotactic guidance are reported.

OBJECTIVE

To show an alternative surgical technique for correcting and fusing complex congenital spinal curves.

SUMMARY OF BACKGROUND DATA

Children with congenital scoliosis can have progressive curves causing significant multiplanar deformities. In older children, traditional approaches to spinal corrective surgery including fusion in situ, convex growth arrest, and hemivertebra excision can achieve only limited corrections.

METHODS

Three older patients who had congenital scoliosis with significant multiplanar curves underwent one-stage posterior transpedicular eggshell osteotomy. Three-dimensional reconstructive images and frameless stereotactic guidance were used for preoperative selection of osteotomy levels and accurate placement of pedicle screws. After completion of the osteotomy, closure was obtained with extension of the hips.

RESULTS

The average coronal correction of the major curve was 28.7 degrees (range, 22-33 degrees ). The average correction of the plumb line or lateral displacement from the center of the trunk was 4.8 cm (range, 3-7.5 cm). A significant kyphotic deformity was corrected 38 degrees, and a pelvic tilt was reduced from 7 to 3 cm.

CONCLUSIONS

One-stage posterior reduction eggshell osteotomy can be used to correct a sagittal and/or coronal congenital spinal curve imbalance. Frameless stereotactic guidance for solid pedicle screw fixation was essential to the achievement of rigid spinal stabilization before arthrodesis. Transpedicular eggshell osteotomy is a technique that should be considered for older patients who have congenital scoliosis with multiplanar spinal abnormalities.

Simultaneous anterior-posterior thoracolumbar spine surgery

The purpose of this article is to report our experience with simultaneous anterior and posterior approach spine surgery. The patient is placed in the decubitus position. Two teams of spine surgeons simultaneously perform surgical approaches, decompression, arthrodesis, and instrumentation. No repositioning, repreparing, or redraping is necessary. Twelve patients with varying lesions underwent this procedure. This technique is presented as an alternative to the sequential single-staged anterior and posterior procedure and the two-staged procedures performed under separate anesthetics. Although no statistical significance can be concluded, we believe a larger series will demonstrate that operative time is decreased, potential risks of repositioning are avoided, and superior exposure and mobilization of spinal elements are afforded. Exposure, decompression, and stabilization posteriorly is feasible in the decubitus position.

One-stage posterior hemivertebra resection and correction using segmental posterior instrumentation

STUDY DESIGN

A retrospective study of 12 patients with congenital kyphoscoliosis caused by a single hemivertebra who underwent one-stage posterior hemivertebra resection and correction by posterior segmental instrumentation.

OBJECTIVES

To evaluate the surgical outcomes of 12 patients with hemivertebra treated by hemivertebra resection by single posterior approach and correction with segmental posterior instrumentation.

SUMMARY OF BACKGROUND DATA

Congenital scoliosis caused by hemivertebra causes extremely severe curves in some patients. Posterior fusion or posterior and anterior hemi-epiphysiodesis is performed to prevent progression of the deformity. The results of these procedures have been variable and not promising, especially in an adolescent patient with fixed kyphoscoliotic deformity. Hemivertebra resection offers more certain results and better correction of the deformity. To date, hemivertebra resection is performed by anterior and posterior approaches either by one-stage or two-stage operation. Few reports have been published describing a procedure consisting of one-stage posterior hemivertebra resection and correction of the deformity by segmental posterior instrumentation.

METHODS

A total of 12 patients with a single hemivertebra between the ages 8-24 years who underwent operative treatment were evaluated for a minimum of 2 years. All patients had a single nonincarcerated hemivertebra [T9 (1 patient), T10 (2), T11 (2), T12 (4), and L1 (3)]. After posterior hemivertebra resection, segmental posterior instrumentation was used for correction of the kyphoscoliotic deformity [CD (4 patients), Kaneda SR (2), and ISOLA (6)]. Radiographic evaluations were conducted on the preoperative, postoperative, and follow-up standing posteroanterior and lateral radiographs.

RESULTS

All 12 patients had kyphoscoliotic deformity. Preoperative scoliosis averaging 49 degrees was corrected to 18 degrees (correction rate, 64%). Preoperative kyphosis of 40 degrees was corrected to 17 degrees of kyphosis. Trunk shift of 23 mm was improved to 3 mm. Correction loss was 2 degrees in the frontal plane and 3 degrees in the sagittal plane, and no patients showed more than 5 degrees of correction loss. No intraoperative complications were noted. Solid fusion was obtained in all patients, and no implant failure was verified at the final radiographic evaluations.

CONCLUSIONS

This study indicated that correction of kyphoscoliosis caused by a single hemivertebra can be effectively conducted by one-stage posterior hemivertebra resection and correction using segmental posterior instrumentation. The operation was safe, and no associated adverse complications were noted. This procedure is best indicated for adolescent patients with a structural kyphoscoliotic deformity caused by a thoracic or thoracolumbar single hemivertebra.

Congenital scoliosis

Congenital scoliosis is a deformity of the developing spine that results from defects in vertebral development. The developmental etiologies may be classified as either a failure of formation, a failure of segmentation, or a mixture of these two modes of maldevelopment. Early detection and close surveillance of congenital scoliosis is critical, as a rapidly progressive curve may lead to significant deformity, pulmonary restriction, and neurologic problems if not treated. Early surgical treatment is often necessary for rapidly progressive curves.

Luque trolley and convex epiphysiodesis in the management of infantile and juvenile idiopathic scoliosis

STUDY DESIGN

Retrospective analysis of 5-year follow-up data from patients instrumented with Luque trolley with or without convex epiphysiodesis for management of progressive infantile and juvenile idiopathic scoliosis.

OBJECTIVE

To assess results, establish predictors of outcome, and suggest more effective surgical interventions.

SUMMARY OF BACKGROUND DATA

Initial results have been reported. There are no long-term follow-up studies.

METHODS

Luque trolley instrumentation was used in eight patients with idiopathic scoliosis between 1983 and 1984. Luque trolley with convex epiphysiodesis was used in 18 patients between 1984 and 1990.

RESULTS

Changes in Cobb angle from 8-week to 5-year follow-up are as follows. For Luque trolley alone, Cobb angle worsened for all patients. For progressive infantile scoliosis managed with Luque trolley and convex epiphysiodesis, Cobb angle worsened in seven, remained unchanged in four, and improved in two patients. Mean age at operation was 3.1 years (range, 1.5-7.4 years), and instrumented spinal growth was 32% of expected growth. Preoperation Cobb angle was 65 degrees (range, 40-95 degrees). Cobb angle at 5-year follow-up was 32 degrees (range, 0-86 degrees), which is predicted by preoperation apical concave rib-spinal angle (P = 0.002) and upper end vertebral tilt (P = 0.04). For juvenile idiopathic scoliosis managed with Luque trolley and convex epiphysiodesis, Cobb angle worsened in three patients and improved in one.

CONCLUSIONS

Luque trolley instrumentation alone does not prevent curve progression. Additional convex epiphysiodesis results in curve resolution in some patients, which suggests a growth effect. Both spine and rib factors predict Cobb angle at 5-year follow-up.