Sacral-Alar-Iliac Fixation in Children with Neuromuscular Scoliosis: Minimum 5-Year Follow-Up

Frequency and predictors of complication clustering within 30 days of spinal fusion surgery: a study of children with neuromuscular scoliosis

PURPOSE

There is limited information on the clustering or co-occurrence of complications after spinal fusion surgery for neuromuscular disease in children. We aimed to identify the frequency and predictive factors of co-occurring perioperative complications in these children.

METHODS

In this retrospective database cohort study, we identified children (ages 10-18 years) with neuromuscular scoliosis who underwent elective spinal fusion in 2012-2020 from the National Surgical Quality Improvement Program-Pediatric database. The rates of co-occurring complications within 30 days were calculated, and associated factors were identified by logistic regression analysis. Correlation between a number of complications and outcomes was assessed.

RESULTS

Approximately 11% (709/6677 children with neuromuscular scoliosis undergoing spinal fusion had co-occurring complications: 7% experienced two complications and 4% experienced ≥ 3. The most common complication was bleeding/transfusion (80%), which most frequently co-occurred with pneumonia (24%) and reintubation (18%). Surgical time ≥ 400 min (odds ratio (OR) 1.49 [95% confidence interval (CI) 1.25-1.75]), fusion ≥ 13 levels (1.42 [1.13-1.79]), and pelvic fixation (OR 1.21 [1.01, 1.44]) were identified as procedural factors that independently predicted concurrent complications. Clinical risk factors for co-occurring complications included an American Society of Anesthesiologist physical status classification ≥ 3 (1.73 [1.27-2.37]), structural pulmonary/airway abnormalities (1.24 [1.01-1.52]), impaired cognitive status (1.80 [1.41-2.30]), seizure disorder (1.36 [1.12-1.67]), hematologic disorder (1.40 [1.03-1.91], preoperative nutritional support (1.34 [1.08-1.72]), and congenital malformations (1.20 [1.01-1.44]). Preoperative tracheostomy was protective against concurrent complications (0.62 [0.43-0.89]). Significant correlations were found between number of complications and length of stay, non-home discharge, readmissions, and death.

CONCLUSION

Longer surgical time (≥ 400 min), fusion ≥ 13 levels and pelvic fixation are surgical risk factors independently associated with co-occurring complications, which were associated with poorer patient outcomes. Recognizing identified nonmodifiable risk factors might also be important for preoperative planning and risk stratification of children with neuromuscular scoliosis requiring spinal fusion.

LEVEL OF EVIDENCE

Level IV evidence.

Pelvic Fixation Technique Using the Ilio-Sacral Screw for 173 Neuromuscular Scoliosis Patients

Pelvic fixation remains one of the main challenging issues in non-ambulatory neuromuscular scoliosis (NMS) patients, between clinical effectiveness and a high complication rate. The objective of this multicenter and retrospective study was to evaluate the outcomes of a technique that was applied to treat 173 NMS patients. The technique is not well-known but promising; it uses the ilio-sacral screw, combined with either the posterior spinal fusion or fusionless bipolar technique, with a minimum follow-up of two years. The mean operative age of the patients was 13 ± 7 years. The mean preoperative main coronal curve was 64° and improved by a mean of -39° postoperatively. The mean preoperative pelvic obliquity was 23°, which improved by a mean of -14° postoperatively. No decrease in the frontal or sagittal correction was observed during the last follow-up. The sitting posture improved in all cases. Twenty-nine patients (17%) had a postoperative infection: twenty-six were treated with local debridement and antibiotics, and three required hardware removal. Fourteen mechanical complications (8%) occurred: screw malposition (n = 6), skin prominence (n = 1), and connector failure (n = 1). This type of surgery is associated with a high risk for infection. Comorbidities, rather than the surgery itself, were the main risk factors that led to complications. The ilio-sacral screw was reliable and effective in correcting pelvic obliquity in NMS patients. The introduction of intraoperative navigation should minimize the risk of screw misplacement and facilitate revision or primary fixation.

Multi-rod posterior correction only with halo-femoral traction for the management of adult neuromuscular scoliosis (> 100°) with severe pelvic obliquity: a minimum 5-year follow-up

BACKGROUND

Many patients with neuromuscular scoliosis (NMS) experience a variety of difficult medical problems that aggravate the development effects of progressive scoliosis and pelvic obliquity (PO). The objective of the current study was to assess the safety and effectiveness of multi-rod posterior correction only (MRPCO) with halo-femoral traction (HFT) for the management of adult NMS (> 100°) with severe PO.

METHODS

From 2012 to 2017, 13 adult patients who suffered from NMS (> 100°) with severe PO underwent MRPCO with HFT. The radiography parameters in a sitting position, such as the coronal Cobb angle of the main curve, the PO and the trunk shift (TS), were measured at the preoperative, postoperative and final follow-up stages. The preoperative and final follow-up assessment of the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) was taken.

RESULTS

The average follow-up span was 68.15 ± 6.78 months. There was decreased postoperative coronal Cobb angle with an average mean of 125.24° ± 11.78° to 47.55° ± 12.10°, with a correction rate of 62.43%; the PO was reduced to 6.25° ± 1.63° from 36.93° ± 4.25° with a correction rate of 83.07%; the TS was reduced to 2.41 cm ± 1.40 cm from 9.19 cm ± 3.07 cm. There was significant improvement in all parameters compared to the preoperative data. The VAS score reduced from 4.77 ± 0.93 to 0.69 ± 0.75, and the ODI score reduced from 65.38 ± 16.80 to 28.62 ± 12.29 at the final follow-up.

CONCLUSIONS

Treatment of adult NMS (> 100°) with severe PO could be safe and effective with MRPCO with HFT. In order to obtain the optimum sitting balance, this could reduce the prevalence of complications and rectify the curvature and the correction of PO.

Clinical and radiological efficacy of spino-pelvic fixation in the treatment of neuromuscular scoliosis

Pelvic fixation is performed to obtain proper coronal and sagittal alignment when the pelvic obliquity is more than 15º in patients with neuromuscular scoliosis (NMS). Since many NMS patients were wheelchair or bed-ridden status, there has been controversy on the effect of pelvic fixation. Therefore, the purpose of this study is to analyze the effects of pelvic fixation on correction of spinal deformity and quality of life (QoL) in NMS patients. A total of 77 NMS patients who underwent deformity correction were divided into three groups and retrospectively analyzed preoperatively, postoperatively, and at 2-year follow-up: pelvic fixation group (Group A, n = 16), fixed to S1 (Group B, n = 33), and fixed to L5 (Group C, n = 28). The correction rate of scoliosis was 60.0%, 58.0%, and 56.7% in groups A, B, and C, respectively, with no statistical difference (P > 0.05). The correction rate of pelvic obliquity was 61.3%, 42.8%, and 57.5% in respective groups A, B, and C, with no significance (P > 0.05). The correction loss of scoliosis and pelvic obliquity showed no statistical significance between three groups for 2-year follow-up (all Ps > 0.05). There were no significant differences regarding clinical outcomes and postoperative complications among the three groups (all Ps > 0.05). Therefore, pelvic fixation using iliac screws is not substantially influencing radiological and clinical outcomes in the patients with NMS.

Neuromuscular Scoliosis: A Dual-Surgeon Approach

OBJECTIVE

Neuromuscular Scoliosis (NMS) causes severe deformity and operative correction for these patients carries high complication rates. We present a retrospective study comparing a series of consecutive patients who underwent posterior fusion via a single-surgeon (SS) approach with a consecutive series of patients treated via a dual-surgeon (DS) approach.

METHODS

Patients with NMS who underwent posterior fusion via a SS approach from 2019 to 2022 were analyzed and compared to a series of patients with NMS who underwent posterior fusion via a DS approach.

RESULTS

In the SS group, the average estimated blood loss (EBL) was 675 mL, average length of stay (LOS) was 6.3 days, average operative time (OT) was 6.5 hours, average packed red blood cell transfusion was 1.5 units, with a complication rate of 30%. The DS group had an average EBL of 400 mL, a LOS of 4.8 days, an OT of 4.75 hours, an average packed red blood cell transfusion of 0.8 units, with a complication rate of 20%. The DS approach was significant for a lower EBL, OT (P < 0.001), and LOS (P < 0.03).

CONCLUSIONS

This study suggests that for patients with NMS the DS approach decreases OT, EBL, complication rates, and LOS. This further supports that this approach may benefit outcomes in NMS patients.

S2-Alar-iliac screw fixation for paediatric neuromuscular scoliosis: Preliminary results after two years

BACKGROUND

Correcting pelvic obliquity is among the main goals of surgery for neuromuscular scoliosis. Spino-pelvic fixation must be stable and capable of withstanding the considerable mechanical forces applied at the lumbo-sacral junction. Selection of the best anchoring option is therefore crucial. S2-alar-iliac (S2AI) screws, which are used in adults, are less often chosen in the French paediatric spinal-surgery community. The objective of this study was to report our preliminary experience with S2AI screws used in the treatment of paediatric patients with neuromuscular scoliosis.

HYPOTHESIS

Pelvic anchoring by means of S2AI screws is reliable and technically feasible in non-ambulatory children with neuromuscular scoliosis.

MATERIALS AND METHODS

Consecutive non-ambulatory patients who underwent scoliosis surgery with S2AI screw fixation to the pelvis between 2016 and 2018 were retrospectively included. The surgical procedure consisted in either posterior spinal fusion (PSF) or magnetic growing rod (MGR) implantation. In all patients, radiographs were obtained before surgery, within 3 months after surgery, and at last follow-up; and low-dose computed tomography (CT) was performed before and after surgery.

RESULTS

We included 25 patients with a mean age of 13.8±4.0 years, 18 managed by PSF and 7 by MGRs. Screw diameters ranged from 7.5 to 9.5mm and all screws were at least 60mm in length. The diameters and lengths were the same on both sides in 16 (89%) patients in the PSF group and in all patients in the MGR group. At last follow-up after a mean of 35.5±3.0 months, pelvic obliquity was corrected in all 23 patients with this abnormality before surgery. Complications consisted of lateral cortical screw breakthrough in 8 (32% of screws) patients and screw malposition in 2 (8% of screws) patients. No clinically significant complications related to the fixation material were recorded.

DISCUSSION

The results of our study demonstrate the feasibility of S2AI screw fixation in paediatric patients with neuromuscular scoliosis. Pelvic asymmetry and dysmorphism do not contra-indicate the procedure but must be evaluated before surgery. Further work is needed to assess the potential long-term consequences on pain and growth of screw passage through the sacro-iliac joints.

LEVEL OF EVIDENCE

IV, retrospective study.

Sacral-Alar-Iliac (SAI) Fixation in Children With Spine Deformity: Minimum 10-Year Follow-Up

INTRODUCTION

Sacral-alar-iliac (SAI) screws are utilized to achieve pelvic fixation in spine deformity patients. The primary purpose of this study is to investigate the long-term outcomes of pediatric patients with scoliosis treated with posterior spinal fusion and SAI fixation at 10-year clinical and radiographic follow-up.

METHODS

We reviewed the clinical and radiographic records of patients aged 18 years or below treated for scoliosis with posterior spinal fusion using SAI fixation. Pelvic obliquity and the major coronal curve were determined at the preoperative visit and 6-week, 1-year, 5-year, and 10-year postoperative visits. SAI screw-specific data collected included screw dimensions, rate of screw revision, pain at the SAI screw sites, presence of lucency >2 mm around the screw, screw loosening or breaking, and deep surgical site infections.

RESULTS

Ninety-seven of 151 patients (75%) were included. The average age at index surgery was 13.5±3.1 years, and the most common diagnosis was cerebral palsy (67%). The mean duration of follow-up was 11±3 years. The mean pelvic obliquity measured 20±8.0 degrees preoperatively, and 8.7±4.0 degrees at the 10-year follow-up. There were no significant difference in pelvic obliquity when comparing the 10-year follow-up visit with the 6-week postoperative follow-up. Average screw dimensions were 8.4×68.8 mm. By the 10-year follow-up, 4 patients (4%) had at least 1 SAI screw-related complication. Of these patients, 2 (2%) had pain at 1 SAI screw, 4 (4%) had lucency around the screw, and 3 (3%) had broken or loose screws. Two (2%) required SAI screw revision because of late deep wound infection, and underwent exchange with a longer screw. There were no intrapelvic protrusions, vascular, or neurological complications.

CONCLUSIONS

SAI screws are a safe and effective method for pelvic fixation in children with spinal deformity. The outcomes at ≥10 years are satisfactory, with low rates of long-term complications and excellent postoperative correction and subsequent maintenance of coronal curvature and pelvic obliquity over time.

LEVEL OF EVIDENCE

Level IV.

Short-term surgical complications of spinal fusion in myelomeningocele

STUDY DESIGN

Retrospective review of a prospective database.

PURPOSE

To determine the rate of short-term surgical complications in the 3-month postoperative period in patients with myelomeningocele (MMC) who underwent surgical correction of spine deformities.

METHODS

This study reviewed the medical records of MMC patients, aged ≤ 18 years, who underwent spine deformity correction between 2012 and 2018. Clinical, radiological, and surgical variables were considered.

RESULTS

Forty-six patients with primary preoperative curve, pelvic obliquity, and kyphosis mean values of 84.9º, 21.5º, and 76.1º, respectively, were included. Thirty-four (74%) patients underwent scoliosis correction and 12 (26%), kyphectomy. A trend in reduction of %EBV (estimated blood volume) loss with antifibrinolytic use from 50.2 ± 32.3 to 33.8 ± 17.2% was observed (p = 0.103). Simultaneous detethering was performed in 13 (27.7%) patients and was not associated with higher short-term complication rates. There were 12 cases of short-term surgical complications (26.1%); among them, six had deep wound infection requiring surgical debridement, and one a superficial wound infection. Drainage time longer than 4 days was significantly associated with wound infection (OR = 15.8, p = 0.01).

CONCLUSIONS

The surgical treatment of neuromuscular scoliosis in MMC patients is challenging because of the high comorbidity rate. Still, we found an admissible rate of short-term surgical complications with a multidisciplinary approach in a setting with extensive spine deformity surgery experience.

Intraoperative traction in neuromuscular scoliosis surgery improves major curve correction when fusing to L5

BACKGROUND

Intraoperative traction has shown improved curve correction in neuromuscular scoliosis surgery. It is found to be superior to anterior release in terms of correction of both main curve and pelvic obliquity. No previous study has examined the effect of intraoperative traction in patients without pelvic fixation.

METHOD

This retrospective study included 40 non-ambulatory (GMFCS 4 or above) patients with neuromuscular scoliosis undergoing surgery with bilateral segmental pedicle screw instrumentation to L5. Twenty-two consecutive patients had intraoperative Gardner-Wells tongs and skin traction (traction group), while the remaining did not (non-traction group). Inclusion criteria were minimum 2-year follow-up, complete medical records and radiographs. Main curve (MC), pelvic obliquity (POB), T1 tilt, kyphosis, rotation, coronal and sagittal balance and preoperative bending radiographs were measured and analyzed in all patients.

RESULTS

Both groups demonstrated roughly 60% MC correction. Preoperative MC was larger in the traction group [97° (49-126) vs. 83° (40-134); P = 0.03]. The measured correction index was almost twice as large in the traction group (1.9 vs. 1.1; P = 0.001). Mean [IQR] 2-year POB was 14° [7-40] in the traction group compared to 16° [4-60] in the non-traction group (P = 0.59). Eleven patients (50%) in the traction group compared to only four (22%) in the non-traction group had a POB within 10° at 2-year follow up (RR: 2.1; 95% CI 0.8-5.2). We found no difference in kyphosis or remaining radiographic parameters. No traction-related complications were recorded.

CONCLUSION

In patients with neuromuscular scoliosis undergoing instrumented fusion to the L5, we found that intraoperative traction increased the degree of MC correction and patients were more likely to achieve POB below 10° without any effects on sagittal parameters or without any detectable significant reduction on rotation.

Clinical Effectiveness of S2-Alar Iliac Screws in Spinopelvic Fixation in Pediatric Neuromuscular Scoliosis: Systematic Literature Review

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To comprehensively review the S2-alar iliac (S2-AI) screw technique for pelvic fixation in pediatric neuromuscular scoliosis.

METHODS

Articles identified from the PubMed and EMBASE databases were reviewed for relevance and applicability, and the studies were summarized.

RESULTS

Eight articles met the inclusion criteria. A total of 277 pediatric patients underwent spinopelvic fixation using S2-AI fixation for neuromuscular scoliosis; the mean follow-up was 3 years (range = 0.75-6 years). Six articles had level III evidence (5 retrospective cohort studies, 1 observational study), and 2 articles had level IV evidence (case series). Wound complications occurred in 34 (12.2%) patients. Instrumentation complications occurred in 36 patients (13.0%), including lucency around the screw (6.5%), screw fracture (3.6%), disengaging of the set/screw or rod from the tulip head (2.8%), and screw displacement (0.7%). Three patients (1.1%) required reoperation for instrumentation failures. The overall reoperation rate-including 3 hardware replacements and 3 cases of L5-S1 pseudarthrosis-was 2.1%. The mean Cobb angle correction was 51.4°, and the mean pelvic obliquity correction was 14.8°; deformity correction was maintained at 3- and 5-year follow-ups. There were 10 (3.6%) cases of implant prominence/implant-related pain, 1 case of sacroiliac joint pain (resolved with longer screw placement), and no major neurological or vascular complications secondary to S2-AI screw placement.

CONCLUSIONS

This review suggests that the use of S2-AI screws in pediatric neuromuscular scoliosis is efficacious with a reasonable safety profile and provides a useful technique for pelvic fixation in children with scoliosis.

Should instrumented spinal fusion in nonambulatory children with neuromuscular scoliosis be extended to L5 or the pelvis?

Aims

It is uncertain whether instrumented spinal fixation in nonambulatory children with neuromuscular scoliosis should finish at L5 or be extended to the pelvis. Pelvic fixation has been shown to be associated with up to 30% complication rates, but is regarded by some as the standard for correction of deformity in these conditions. The incidence of failure when comparing the most caudal level of instrumentation, either L5 or the pelvis, using all-pedicle screw instrumentation has not previously been reported. In this retrospective study, we compared nonambulatory patients undergoing surgery at two centres: one that routinely instrumented to L5 and the other to the pelvis.

Methods

In all, 91 nonambulatory patients with neuromuscular scoliosis were included. All underwent surgery using bilateral, segmental, pedicle screw instrumentation. A total of 40 patients underwent fusion to L5 and 51 had their fixation extended to the pelvis. The two groups were assessed for differences in terms of clinical and radiological findings, as well as complications.

Results

The main curve (MC) was a mean of 90° (40° to 141°) preoperatively and 46° (15° to 82°) at two-year follow-up in the L5 group, and 82° (33° to 116°) and 19° (1° to 60°) in the pelvic group (p < 0.001 at follow-up). Correction of MC and pelvic obliquity (POB) were statistically greater in the pelvic group (p < 0.001). There was no statistically significant difference in the operating time, blood loss, or complications. Loss of MC correction (> 10°) was more common in patients fixated to the pelvis (23% vs 3%; p = 0.032), while loss of pelvic obliquity correction was more frequent in the L5 group (25% vs 0%; p = 0.007). Risk factors for loss of correction (either POB or MC) included preoperative coronal imbalance (> 50 mm, odds ratio (OR) 11.5, 95%confidence interval (CI) 2.0 to 65; p = 0.006) and postoperative sagittal imbalance (> 25 mm, OR 11.0, 95% CI1.9 to 65; p = 0.008).

Conclusion

We found that patients undergoing pelvic fixation had a greater correction of MC and POB. The rate of complications was not different. Preoperative coronal and postoperative sagittal imbalance were associated with increased risks of loss of correction, regardless of extent of fixation. Therefore, we recommend pelvic fixation in all nonambulatory children with neuromuscular scoliosis where coronal or sagittal imbalance are present preoperatively. Cite this article: Bone Joint J 2020;102-B(2):261–267.

Occiput-to-Pelvis Spinal Arthrodesis: A Case Series

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To describe the indications, operative course, and outcomes in eight pediatric patients who underwent occiput-to-pelvis (O-P) spinal arthrodesis.

SUMMARY

Spinal arthrodesis from the occiput to pelvis is needed for some children with extensive spine deformity. There are few reports of patients with O-P arthrodesis.

METHODS

We reviewed records of pediatric patients who underwent spinal arthrodesis to treat spine deformity between 1987 and 2017 at one institution. Eight patients (six girls) who underwent staged O-P arthrodesis were identified. Underlying conditions, indications for surgery, medical comorbidities, operative courses, complications, and imaging of these patients were recorded.

RESULTS

Diagnoses were neuromuscular disorders in five patients and syndromic disorders in three patients. Mean ages were 9.7 ± 4.1 years at index surgery and 16.8 ± 4.6 years at completion of O-P arthrodesis. Patients underwent a mean of three operations (range, two to five). Occipitocervical arthrodesis was the final operation in six of eight patients (all but the two patients with Loeys-Dietz syndrome). Mean follow-up after the last procedure was 8.5 ± 7.1 years. Two patients underwent revision for protruding occipital implants, and one patient underwent revision for thoracic pseudarthrosis. No patients developed postoperative infections or new neurologic deficits. At final follow-up, Scoliosis Research Society-22r questionnaire scores were lowest for Function (2.6 ± 1.0 of 5 possible points) and highest for Satisfaction (4.1 ± 1.4).

CONCLUSIONS

O-P arthrodesis can benefit patients with extensive spine deformity from neuromuscular or syndromic causes. Patients were young at first operation, which may suggest that younger patients are at higher risk than older patients of major progression of deformity in other spinal regions after deformity correction. Health-related quality of life and radiographic outcomes suggest that patients who underwent O-P arthrodesis had satisfactory outcomes and maintenance of correction during a mean of 8.5 years of follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

A comprehensive biomechanical analysis of sacral alar iliac fixation: an in vitro human cadaveric model

In BriefIn this in vitro investigation, we compared the multidirectional flexibility properties of sacral alar iliac fixation with conventional methods of sacral and sacroiliac fixation using nondestructive and destructive investigative methods. The study demonstrated that S1-2 sacral fixation alone significantly increases sacroiliac motion under all loading modalities, while sacral alar iliac fixation reduced motion in axial rotation at the sacroiliac joint and offers potential advantages of a lower instrumentation profile and ease of assembly compared to conventional sacroiliac screw instrumentation.

The role of sacral laminoplasty in the management of spina bifida and sacral cystic lesions: case series

OBJECTIVE

Although laminae are not viewed as essential structures for spinal integrity, in the sacrum the anatomical weakness and gravity makes it a vulnerable area for CSF accumulation and expansion. The congenital or postoperative defects of sacral laminae, such as in patients with spina bifida, make this area more susceptible to forming progressive dural ectasia, pseudomeningocele, or expansile arachnoid cyst (Tarlov cyst). In addition, adhesions between the dura and surrounding soft tissue after laminectomy can cause some local symptoms, which are difficult to relieve. The authors propose that sacral laminoplasty with titanium mesh can provide a rigid support and barrier to resolve these sacral lesions and local symptoms.

METHODS

From January 2016 to December 2017, patients with progressive CSF-containing lesions in the sacral area and defective sacral laminae were included in the study. After repair of the lesion, the authors performed sacral laminoplasty with titanium mesh in each patient. Subsequently, the soft tissue and skin were closed primarily.

RESULTS

A total of 6 patients were included. Four patients with repaired myelomeningocele had progressive dural ectasia. One patient with lipomyelomeningocele previously underwent detethering surgery and developed postoperative pseudomeningocele. One patient had a symptomatic Tarlov cyst. Four of these 6 cases presented with low-back pain and local tenderness. During follow-up, ranging from 13 to 37 months, all 6 patients experienced no recurrence of dural ectasia or pseudomeningocele and were free from local symptoms.

CONCLUSIONS

Sacral laminoplasty with titanium mesh is a safe and effective procedure for treating progressive sacral dural ectasia and refractory pseudomeningocele, preventing CSF leakage as well as relieving local symptoms that may occur years after previous surgery for spina bifida.

USE OF ALAR-ILIAC S2 SCREW TECHNIQUE IN SCOLIOSIS SECONDARY TO MYELOMENINGOCELE

ABSTRACT Objective: To evaluate retrospectively the results related to the use of pelvic fixation with alar-iliac S2 screw in individuals with myelomeningocele. Methods: Retrospective study of cases surgically treated with this technique, between January 2015 and March 2018 at the Pequeno Principe Children's Hospital. Radiographic images and clinical records were analyzed in search of complications. Results: Twelve patients with mean age of 13.3 years were treated at the time of surgery. The mean follow-up was 11.5 months. The mean of the highest magnitude curve measured by the Cobb angle in the preoperative period was 83.8°; while in the last postoperative follow-up was 29.5° (correction of 65%). The mean pelvic obliquity was 23.1° in the preoperative period and in the postoperative was 7.1° (correction of 69%). Only 2 cases (17%) with complications associated with material failure at the level of sacroiliac fixation, due to the unilateral release of the head of the polyaxial S2 iliac screw. Conclusions: The technique of pelvic fixation in the scoliosis secondary to myelomeningocele with the use of S2 alar-iliac screws has shown satisfactory results, with only two complications (17%) directly related to pelvic fixation in the operated cases. Level of Evidence IV; Series of Cases.

Current concepts in neuromuscular scoliosis

PURPOSE OF REVIEW

Spinal deformity is a common issue in pediatric patients with an underlying neurological diagnosis or syndrome. Management of neuromuscular scoliosis (NMS) is a major part of the orthopedic care of such patients, as the deformity is often progressive, and may affect gait, seating and positioning. In addition, untreated large spinal deformities may be associated with pain and/or cardiopulmonary issues over time.

RECENT FINDINGS

Recent changes in medical management of the underlying disease process appears to alter the natural history of certain neuromuscular conditions, and in the case of patients with Duchenne's muscular dystrophy significantly diminish the incidence of spinal deformity. In the most common diagnosis associated with NMS, cerebral palsy, there is evidence that despite a high complication rate, surgical management of spinal deformity is associated with measurable improvements in validated health-related quality-of-life measures. Spinal deformity is a common finding in patients with neurological diagnoses. It is important for those involved in the care of these patients to understand the natural history of NMS, as well as the potential risks and benefits to the patient and caregivers, of surgical and non-surgical interventions.

Second Sacral Alar Screw Fixation: Anatomic Study of Three-Dimensional Computed Tomography and Case Report

OBJECTIVE

S2 alar screw would be an alternative choice without breaking the sacroiliac joint. The aim of this study was to measure radiographic parameters for optimal placement of posterior S2 alar screw for instrumentation and fusion.

METHODS

Three-dimensional computed tomography scans of the pelvis of 60 normal adults were used to map the S2 alar screw. Entry point was typically chosen lateral and superior to the S2 dorsal foramen. Ideal S2 alar screw trajectories were explored by rotating the three-dimensional pelvis, while ensuring trajectories were of maximum length and width. After identification of an optimal trajectory, related linear anatomic parameters and sagittal and transverse angles were determined.

RESULTS

Ideal S2 alar screw trajectories were identified in each computed tomography scan. According to this morphometric study, trajectories for female patients were more lateral in the transverse plane (female 33.73 ± 5.99° vs. male 29.82 ± 4.11°, P < 0.001). Maximal length of trajectory in male patients was significantly longer than in female patients (female 40.82 ± 4.29 mm vs. male 43.42 ± 4.02 mm, P = 0.001). Fourteen S2 alar screws were used in 7 patients with high-grade spondylolisthesis, scoliosis, or nonunion at lumbosacral site. No complications occurred during S2 alar screw placement. One S2 screw failed owing to severe local osteoporosis. No patient developed local pain or wound-related problems.

CONCLUSIONS

S2 alar screw is an alternative sacral fixation point to provide additional biomechanical stability of lumbosacral constructs. A trajectory with maximum length through the S2 ala can be determined using three-dimensional computed tomography.

Anatomic Trajectory for Iliac Screw Placement in Pediatric Scoliosis and Spondylolisthesis: An Alternative to S2-Alar Iliac Portal

STUDY DESIGN

Single-center retrospective study.

OBJECTIVE

To analyze two-year postoperative outcomes following spinopelvic fixation in pediatric patients using the anatomic trajectory (AT) portal for iliac screws.

SUMMARY

Iliac fixation is crucial in situations requiring fusion to sacrum. Challenges include complex anatomy, pelvic deformation, severe deformity, and previous surgery. The PSIS portal requires significant dissection, rod connectors, and complex bends. The SAI portal requires navigating the screw across the SI joint to the ilium. The anatomic trajectory (AT), first reported in 2009, is between the PSIS and SAI portal, without prominence, connectors, or complex bends.

METHODS

Fifty-four patients aged ≤18 years requiring instrumentation to the Ilium with minimum follow-up of two years (mean 44 months) were clinically and radiographically evaluated. Changes in coronal curve magnitude and pelvic obliquity were assessed using paired t test for patients with cerebral palsy. Spondylolisthesis reduction was assessed in patients with moderate- to high-grade spondylolisthesis (Meyerding grade 3 and 4).

RESULTS

A total of 108 iliac screws were inserted using AT portal in 54 patients. Twenty-eight neuromuscular and syndromic patients had an initial mean coronal curve of 85° corrected to 23° at two years (p < .001) and a pelvic obliquity of 22° corrected to 4° (p < .001). Twenty patients with moderate- to high-grade spondylolisthesis treated with reduction and interbody fixation improved significantly with respect to their slip angles (7° ± 14.7° to -7.9° ± 6.1°, p = .003). In the neuromuscular group, two surgical site infections occurred, two had implant fractures, and 12 had asymptomatic iliac screw loosening, none requiring revision. In the spondylolisthesis group, there were no neurologic complications and one had prominent screw requiring removal. Of 108 iliac screws, 2 rod connectors were employed.

CONCLUSION

Iliac screw insertion using the AT portal is a safe and effective method of pelvic fixation in pediatric patients with satisfactory radiographic correction and minimal complications.

LEVEL OF EVIDENCE

Level 4.