Sublaminar Wires Research Articles

Severe Rigid Scoliosis Deformity Correction Using Extended Posterior Release and Instrumentation: A Retrospective Study.

Sever rigid scoliotic deformity (magnitude of the curve >80° and <25% correction on bending film) correction is a great challenge to spine surgeons. Severe scoliosis when untreated or not treated properly, may lead to severe complications due to curve progression. The aim of operative management is to achieve significant correction of sagittal, coronal, and rotational deformity to avoid neurodeficit, maintain sagittal balance, and improve cardiopulmonary function. In this retrospective study, eight patients with severe rigid scoliosis who underwent through single-staged extended posterior release and spinal fusion between March 2022 and November 2023. The surgical procedures were the excision of the posterior ligament and spinous process, laminectomy, excision of ligament flavum, facetectomy, and posterior spinal fusion utilizing pedicle screws, rods, and sub-laminar wires. Patients were evaluated radiologically using posteroanterior and lateral X-rays of the whole spine and computed tomography scans. Demographic data, pre- and post-operative cobbs angle, osteotomized segment, instrumentation segments, blood loss, operation duration, follow-up duration, and complications were recorded. Pre-operative mean cobbs angle was 94.1° (range 83-110°) and post-operative mean cobbs angle was 33.3° (range 28-42°) with 64.6% scoliosis correction. The mean estimated blood loss was 517 mL (range 300-580 mL). The mean operation duration was 272.5 min (210-340 min). Mean spinal fixation fusion segments were 11.1 (range 8-14). No major complications were noted. Our study concluded that extended posterior-only release, facetectomy, and posterior spinal fusion by utilizing pedicle screws and pre-contoured rods significantly corrected severe and rigid scoliosis with a high correction rate and avoid complications of anterior release. Hence, we can achieve remarkable correction in rigid scoliosis using the proper choice of levels, proper implant, and extended posterior release.

Instrumentation of hypoplastic pedicles with patient-specific guides

PurposeHypoplastic pedicles of the thoracolumbar spine (<5 mm diameter) are often found in syndromic deformities of the spine and pose a challenge in pedicle screw instrumentation. 3D-printed patient-specific guides might help overcome anatomical difficulties when instrumenting pedicles with screws, thereby reducing the necessity for less effective fixation methods such as hooks or sublaminar wires. In this study, the surgical feasibility and clinical outcome of patients with hypoplastic pedicles following pedicle screw instrumentation with 3D-printed patient-specific guides were assessed.MethodsHypoplastic pedicles were identified on preoperative computed tomography (CT) scans in six patients undergoing posterior spinal fusion surgery between 2017 and 2020. Based on these preoperative CT scans, patient-specific guides were produced to help with screw instrumentation of these thin pedicles. Postoperatively, pedicle-screw-related complications or revisions were analyzed.Results93/105 (88.6%) pedicle screws placed with patient-specific guides were instrumented. 62/93 (66.7%) of these instrumented pedicles were defined as hypoplastic with a mean width of 3.07 mm (SD ±0.98 mm, 95% CI [2.82–3.32]). Overall, 6 complications in the 62 hypoplastic pedicles (9.7%) were observed and included intraoperatively managed 4 cerebrospinal fluid leaks, 1 pneumothorax and 1 delayed revision due to 2 lumbar screws (2/62, 3.3%) impinging the L3 nerve root causing a painful radiculopathy. The mean follow-up time was 26.7 (SD ±11.7) months. Complications were only noted when the pedicle-width-to-screw-diameter ratio measured less than 0.62.ConclusionPatient-specific 3D-printed guides can aid in challenging instrumentation of hypoplastic pedicles in the thoracolumbar spine, especially if the pedicle-width-to-screw-diameter ratio is greater than 0.62.

Advantages of Combined Use of Claw Hooks and Sublaminar Wires as the Upper Foundation of Long Fixation from the Thoracic Spine to the Pelvis in Osteoporotic Cases: A Finite Element Analysis of Proximal Junction Stress

Advantages of Combined Use of Claw Hooks and Sublaminar Wires as the Upper Foundation of Long Fixation from the Thoracic Spine to the Pelvis in Osteoporotic Cases: A Finite Element Analysis of Proximal Junction Stress

C1–C2 Transarticular Screw with Sublaminar Wiring for Reducible Atlantoaxial Dislocation: Operative Technique and Surgical Nuances

Abstract Transarticular screw provides rigid C1 C2 fixation. It is associated with robust implant construct and high fusion rates. Combining sublaminar wiring provides rigid three point fixation. This technique can be safely considered in reducible AAD where a wide C2 isthmus along with a normal Vertebral artery course is present. Authors describe the technique in detail with indications, benefits over other similar procedures, short falls and detailed operative steps. “Pearls and Pitfalls” adds a fresh perspective to this less often considered procedure.

Kyphectomy in myelomeningocele revisited: risk factors for failure.

Lumbar kyphosis occurs in approximately 8-20% of patients with myelomeningocele (MMC). The purpose of this article is to analyze the risks and benefits of vertebrectomy and spinal stabilization in MMC children with severe lumbar kyphosis and to establish treatment guidelines. This is an IRB-approved retrospective analysis of 59 patients with MMC who underwent kyphectomy and posterior instrumentation in three centers. Average age at surgery was 7.9years (2weeks-17years). Sitting trunk position, skin status, kyphosis angle, and thoracic lordosis were analyzed preoperatively, postoperatively, and at an average follow-up of 8.2years (range 2.5-16). The correction was maintained by applying a short posterior instrumentation in 6 patients, and extending to the pelvis in 53 cases. Pelvic fixation was achieved using the Warner and Fackler technique in 24 patients, the Dunn-McCarthy in 8, Luque-Galveston in 8, sacral screws in 2, and ilio-sacral screws in 11. Sitting position improved postoperatively in 47 of the 53 patients who underwent pelvic fixation and only in one patient with short instrumentation. All 6 patients with long instrumentation and poor postoperative sitting balance were in the Dunn-McCarthy fixation group. Skin sores at the apex of the deformity disappeared postoperatively in all patients but recurred in two patients with short instrumentations. Kyphosis angle improved from 109° (45°-170°) preoperatively to 10° (0°-45°) postoperatively and 21° (0°-55°) at last follow-up. The best results were seen in cases where a cross-k-wire fixation of the kyphectomy site was used, augmented with a long thoraco-pelvic instrumentation consisting of Luque sublaminar wires in the thoracic region and a Warner-Fackler type of pelvic fixation. Good results were also found with the bipolar technique and ilio-sacral screw fixation. Six over 24 patients with the Warner and Fackler technique showed gradual dislodgment or hardware failure, with subsequent nonunion of the kyphectomy site in four. Infection, with or without wound dehiscence and/or hardware exposure, occurred in 17 cases, necessitating hardware removal in 9 patients. Lumbar kyphosis in MMC children is best managed by resection of enough vertebrae from the apex to produce a flat lumbar spine, with perfect bone-to-bone contact and long thoraco-pelvic instrumentation using the Warner and Fackler technique through the S1 foramina or the bipolar technique with ilio-sacral screw fixation. Additional local fixation of the osteotomy site using cross-wires with or without cerclage increases the stability of the construct. The majority of complications occurred in patients with short instrumentations or where residual kyphosis persisted postoperatively regardless of the type of pelvic fixation or hardware density. The Dunn-McCarthy technique for pelvic fixation following kyphectomy in MMC was less successful in producing stable pelvic fixation and should not be considered in this patient category.

Delayed myelopathy after remote C1-2 sublaminar wire fixation: illustrative case.

Atlantoaxial sublaminar wiring complications, both early and delayed, have been documented. However, delayed neurological compromise 27 years after successful fusion is a rare but possible occurrence. A 76-year-old male, who had undergone C1-2 sublaminar wire fusion for atlantoaxial instability in 1995, presented with symptoms of progressive right arm weakness, falls, and incontinence of bowel and bladder over a 1-week period. Initial imaging workup revealed bowing of the C1-2 sublaminar wires resulting in cervical spinal cord compression and T2-weighted signal changes. A C1-2 laminectomy was performed to remove the wires and decompress the spinal cord with improvement in the patient's neurological status. This rare case highlights the potential for delayed cervical myelopathy and cord compression from sublaminar wires, even after a successful fusion. In patients with a history of sublaminar wiring who experience new neurological deficits, it is essential to evaluate the hardware for migration.

Case Report: posterior approach with sub-laminar wiring as management of comminuted fracture of the odontoid process of the axis

Background: Odontoid fractures (OF) account for 5-18% and 10-19% of all injuries at C2 and in the cervical region, respectively. According to the Anderson and D'Alonzo classification, there are three main types of OF: Type I, II and III. Most cases involving OF of the axis by high impact trauma result in death. Case presentation: A 21-year-old male patient, with comminuted OF caused by a high impact traffic accident. On admission, the patient reported moderate to severe pain in the posterior craniocervical junction, with significant limitation to lateral rotation of the head and severe cervical muscle spasm. There was evidence of comminuted OF of C2 without apparent displacement in the cervical region. The patient underwent surgery via a posterior approach with double sub-laminar wiring between C1 and C2. The procedure was considered to be completely resolutive with no postoperative complications or sequelae, with total recovery of the patient's functionality. Discussion: The posterior approach is a viable option when the anterior approach is not possible due to the nature of the comminuted fracture and risks of complications, even when it involves a degree of compromise in the rotation of the C1-C2 joint. OF is a medical emergency, requiring individualized treatment tailored to the characteristics of the patient. There are currently no standardized treatment guidelines for OF.

A Modified Self-Growing Rod Technique for Treatment of Early-Onset Scoliosis.

The patient is positioned prone on a radiolucent table, and the spine is prepared and draped in a standard fashion. A posterior midline skin incision is made from the upper to the lower instrumented level. Subperiosteal exposure of the spine is carried out, ensuring that capsules of the facet joints are spared. Pedicle screws are inserted bilaterally at the cranial and caudal ends of the instrumentation. Fixation with pedicle screws of at least 3 levels at the top and bottom end is usually advised; in nonambulatory patients with pelvic obliquity, caudal fixation can be extended to the pelvis with bilateral iliac screws. Sublaminar wires are positioned bilaterally at every level between the cranial and caudal ends of the instrumentation and are passed as medially as possible to avoid damage to the facet joints. Four 5-mm cobalt-chromium rods are cut, contoured, and inserted at each end of the construct. Ipsilateral rods are secured with use of sublaminar wires, making sure that they overlap over a sufficient length to allow for the remaining spinal growth. Correction of the deformity is achieved with use of a combination of cantilever maneuvers and apical translation by progressive and sequential tightening of the sublaminar wires. The wound is closed in layers over a subfascial drain. The patient is allowed free mobilization after surgery. No postoperative brace is required. Nonoperative alternative treatment for EOS includes serial cast immobilization and bracing4. Alternative surgical treatments include traditional growing rods5, magnetically controlled growing rods6, the vertical expandable prosthetic titanium rib-expansion technique7, and the Shilla technique8. The use of compression-based systems (i.e., staples or tether)9 or early limited fusion has also been reported by other authors. The main advantage of our technique is that it relies on physiological spinal growth and does not require surgery or external devices for rod lengthening, which is particularly beneficial in frail patients with a neuromuscular disease in whom repeated surgery is not advised. Segmental fixation by sublaminar wires allows good control of the deformity apex during growth. Concerns regarding early fusion of the spine have not been confirmed in our mid-term follow-up study10. This technique allows correction of the deformity and continuous spinal growth in the years following surgery. At 6.0 years postoperatively, the average main curve correction was reported to be 61% and the average pelvic obliquity correction was 69%. The spine was reported to lengthen an average of 40.9 mm (range, 14.0 to 84.0 mm) immediately postoperatively, and the T1-S1 segment was reported to continue growing at 10.5 mm/year (range, 3.6 to 16.5 mm/year) thereafter10. The most common complication is rod breakage at the thoracolumbar junction, which seems to be more common in patients with idiopathic or cerebral palsy EOS and during the pubertal growth spurt10. Subperiosteal exposure of the spine should be carried out, making sure to preserve facet joints in the unfused area of the spine.Achieve segmental fixation with use of sublaminar wires at every level and pedicle screws at the top and bottom ends of the instrumentation.If pelvic imbalance is present and the patient is nonambulatory, pelvic fixation with iliac screws is advised.First round correction of the deformity is achieved with a cantilever technique; correction fine-tuning can be performed by tightening sublaminar wires.Consider utilizing thicker rods in cases of idiopathic or cerebral palsy EOS. EOS = early-onset scoliosisAP = anteroposteriorEV = end vertebraSSEP = somatosensory evoked potentialsMEP = motor evoked potentialsPJK = proximal junctional kyphosisSMA = spinal muscular atrophyCP = cerebral palsyPACU = post-anesthesia care unit.

Hybrid versus total sublaminar wires in patients with spinal muscular atrophy undergoing scoliosis surgery

BackgroundEarly versions of spinal muscular atrophy (SMA) scoliosis correction surgery often involved sublaminar devices. Recently, the utilization of pedicle screws has gained much popularity. Pedicle screws are generally believed to provide additional deformity correction, but pedicle size and rotational deformity limit their application in the thoracic spine, resulting in a hybrid construct involving pedicle screws and sublaminar wire. Studies of the efficacy of hybrid instrumentation in SMA scoliosis are often limited by the scarcity of the disease itself. In this study, we aimed to compare the surgical outcomes between hybrid constructs involving pedicle screws and sublaminar wire and sublaminar wire alone in patients with SMA scoliosis.MethodsWe retrospectively reviewed the clinical records and radiographic assessments of patients with SMA scoliosis who underwent corrective surgery between 1993 and 2017. The radiographic assessments included deformity correction and progressive changes in the major curve angle, pelvic tilt (PT) and coronal balance (CB). The correction of deformities was observed postoperatively and at the patient’s 2-year follow-up to test the efficacy of each type of construct.ResultsThirty-three patients were included in this study. There were 14 and 19 patients in the wiring and hybrid construct groups, respectively. The hybrid construct group demonstrated a higher major curve angle correction (50.5° ± 11.2° vs. 36.4° ± 8.4°, p < 0.001), a higher apical vertebral rotation correction (10.6° ± 3.9° vs. 4.8° ± 2.6°, p < 0.001), and a reduced progression of the major curve angle at the 2-year follow-up (5.1° ± 2.9° vs. 8.7° ± 4.8°, p < 0.001). A moderate correlation was observed between the magnitude of correction of the apical vertebral rotation angle and the major curve (r = 0.528, p = 0.002).ConclusionThis study demonstrated that hybrid instrumentation can provide a greater magnitude of correction in major curve and apical rotation as well as less major curve progression than sublaminar wire instrumentation alone in patients with SMA scoliosis. Level of evidence III

Atlantoaxial wiring hardware failure resulting in intracranial hemorrhage and hydrocephalus: illustrative case

BACKGROUNDAtlantoaxial sublaminar wiring has many known complications related to hardware failure, but intracranial hemorrhage is a rare complication.OBSERVATIONSA 61-year-old female patient with prior atlantoaxial sublaminar wiring for odontoid fracture nonunion experienced decreased level of consciousness due to a subarachnoid and subdural hemorrhage of the posterior fossa with intraventricular extension and hydrocephalus. Rupture of the sublaminar wire with intramedullary protrusion was the cause of the hemorrhage. The patient was treated with ventriculostomy for hydrocephalus and occipital cervical fusion for spinal instability, along with removal of the broken wire and drainage of a hematoma.LESSONSThis uncommon cause of intracranial hemorrhage highlights an additional risk of atlantoaxial sublaminar wiring compared with other atlantoaxial fusion techniques. In addition, this case suggests cervical instrumentation failure as a differential diagnosis of subarachnoid and subdural hemorrhage of the posterior fossa when a history of prior instrumentation is known.

C1-C2 Wiring With Timed Self-Obsolescence for Complex C2 Body Fracture.

Fractures of C2 are typically managed nonoperatively with good rates of healing. Management decisions are complicated, however, when there are additional fractures in the axis possibly leading to increased instability. Additionally, the techniques used for treating these unstable axis fractures can have either significant complications or permanent loss of range of motion. Here, we present a novel technique for the reduction and stabilization of complex C2 body fracture. A 34-yr-old woman with a complex C2 body fracture, which included a right pars and left lateral mass fracture, presented after a water slide accident. It was felt that this fracture was both unstable and would not heal in an anatomically acceptable way so an open surgical reduction was needed. After consideration of more traditional fusion and osteosynthesis techniques, we chose to perform a C1-C2 internal stabilization with C1 sublaminar and C2 spinous process wiring. The patient was then instructed to wear a Miami J collar for 3 mo. The outcome was favorable with good approximation and healing with preserved range of motion.

Anatomical changes in vertebra in dystrophic scoliosis due to neurofibromatosis and its implications on surgical safety.

Detailed radiological analysis by multimodality imaging. To document anatomical changes jeopardizing instrumentation safety in Neurofibromatosis deformity correction surgeries. The apical and 3 adjacent vertebral segments above and below amounting to 70 segments in 10 NF scoliosis were studied by radiographs, CT and MRI. The changes in lamina, pedicle and vertebral body that could jeopardize pedicle screw and sublaminar wire placement were documented and changes were appropriately classified. Extensive anatomical changes were noted. These changes were more severe at the apex and independent of the curve severity. Both laminae were normal in only 36 (Type 1), rest had either gross asymmetry in length and shape (Type 2; 21) or also in sloping (Type 3; 13). Of the 140 pedicles, normal pedicles were found only in 48 (Type 1); while they were divergent (Type 2; 4) or abnormally elongated with only thinning (Type 3a; 26); or with sclerosis (3b; 34); or very curved and wavy (3c; 23) and even fractured or indistinct (Type 4; 5). It was notable that 92 of the 140 pedicles were unsuitable for pedicle screws. A unique phenomenon of body drift was identified in 29 segments which could jeopardize screw placement and rib dislocation into the canal was found in 18 segments. Gross anatomical changes jeopardizing both sublaminar wire strength and trajectory of pedicle screws were common in NF and independent of curve severity. Therefore, detailed preoperative assessment and planning by a 3D CT are essential.

Supplementation of Screw-Rod C1-C2 Fixation With Posterior Arch Femoral Head Allograft Strut.

Numerous C1-C2 fixation techniques exist for the treatment of atlantoaxial instability. Limitations of screw-rod and sublaminar wiring techniques include C2 nerve root sacrifice and dural injury, respectively. We present a novel technique that utilizes a femoral head allograft cut with a keyhole that rests posteriorly on the arches of C1 and C2 and straddles the C2 spinous process, secured by sutures. To offer increased fusion across C1-C2 without the passage of sublaminar wiring or interarticular arthrodesis. A total of 6 patients with atlantoaxial instability underwent C1-C2 fixation using our method from 2015 to 2016. After placement of a C1-C2 screw/rod construct, a cadaveric frozen femoral head allograft was cut into a half-dome with a keyhole and placed over the already decorticated dorsal C1 arch and C2 spinous process. Notches were created in the graft and sutures were placed in the notches and around the rods to secure it firmly in place. The femoral head's shape allowed for creation of a graft that provides excellent surface area for fusion across C1-C2. There were no intraoperative complications, including dural tears. Postoperatively, no patients had sensorimotor deficits, pain, or occipital neuralgia. 5 patients demonstrated clinical resolution of symptoms by 3 mo and radiographic (computed tomography) evidence of fusion at 1 yr. One patient had good follow-up at 1 mo but died due to complications of Alzheimer disease. The posterior arch femoral head allograft strut technique with securing sutures is a viable option for supplementing screw-rod fixation in the treatment of complex atlantoaxial instability.

The use of sublaminar wires to create semi-rigid junctional fixation in surgical correction of adult degenerative scoliosis

The use of sublaminar wires to create semi-rigid junctional fixation in surgical correction of adult degenerative scoliosis

Ultra-high-molecular-weight polyethylene sublaminar tape as semirigid fixation or pedicle screw augmentation to prevent failure in long-segment spine surgery: an ex vivo biomechanical study.

Complications after adult spinal deformity surgery are common, with implant-related complications occurring in up to 27.8% of cases. Sublaminar wire fixation strength is less affected by decreasing trabecular bone density in comparison to pedicle screw (PS) fixation due to the predominant cortical bone composition of the lamina. Sublaminar fixation may thus aid in decreasing implant-related complications. The goal of this study was to compare fixation characteristics of titanium sublaminar cables (SCs), ultra-high-molecular-weight polyethylene (UHMWPE) tape, PSs, and PSs augmented with UHMWPE tape in an ex vivo flexion-bending setup. Thirty-six human cadaver vertebrae were stratified into 4 different fixation groups: UHMWPE sublaminar tape (ST), PS, metal SC, and PS augmented with ST (PS + ST). Individual vertebrae were embedded in resin, and a flexion-bending moment was applied that closely resembles the in vivo loading pattern at transitional levels of spinal instrumentation. The failure strength of PS + ST (4522 ± 2314 N) was significantly higher compared to the SC (2931 ± 751 N) and PS (2678 ± 827 N) groups, which had p values of 0.028 and 0.015, respectively (all values expressed as the mean ± SD). Construct stiffness was significantly higher for the PS groups compared to the stand-alone sublaminar wiring groups (p = 0.020). In contrast to SC, ST did not show any case of cortical breach. The higher failure strength of PS + ST compared to PS indicates that PS augmentation with ST may be an effective measure to reduce the incidence of screw pullout, even in osteoporotic vertebrae. Moreover, the lower stiffness of sublaminar fixation techniques and the absence of damage to the cortices in the ST group suggest that ST as a stand-alone fixation technique in adult spinal deformity surgery may also be clinically feasible and offer clinical benefits.

Advancements in osteoporotic spine fixation

With the global rise in the population of elderly along with other risk factors, spine surgeons have to encounter osteoporotic spine more often. Osteoporotic spine, however, causes problems in management, particularly where instrumentation is involved, resulting in screw loosening, pull out, pseudoarthroses or adjacent segment kyphosis. Osteoporosis alters the bio mechanics at the bone implant interface resulting in various degrees of fixation failure. Various advancements have been made in this field to deal with such issues in addition to modification of basic surgical techniques such as increasing the diameter and length of the screw, smaller pilot hole, under tapping, longer constructs, supplemental anterior fixation, sublaminar wires or laminar hooks, use of transverse connectors and triangulation techniques, among others. They include novel surgical techniques such as cortical bone trajectory, superior cortical trajectory, double screw technique, cross trajectory technique, bicortical screw technique or prophylactic vertebroplasty. Advances in the screw design include expandable screws, fenestrated screws, conical screws and coated screws. In addition to PMMA cement augmentation, other biodegradable cements have been introduced to mitigate the side effects of PMMA such as calcium phosphate, calcium apatite and hydroxyapatite. Pharmacotherapy with teriparatide can aid fusion and lower the rate of pedicle screw loosening. Many of these strategies have only bio mechanical evidence and require well designed clinical trials to establish their clinical efficacy. Though no single technique is fool proof, little modifications in the existing techniques or utilizing a combination of techniques without adding to the cost of the surgery may help to achieve a near-ideal result. Surgeons have to equip their armamentarium with all the recent advances, and should be open to novel thoughts and techniques.

Golden Wires and Rectangle: A Cost-Effective Treatment for Tuberculosis of the Thoracic Spine.

Study Design:This was a retrospective study.Purpose:The purpose of this study was to compare the functional outcome and cost of surgery for tuberculosis (TB) of the thoracic spine between two commonly used fixation modalities “pedicular screws and rods” and “Hartshill loop rectangle and sublaminar wires.”Overview of Literature:TB is a common ailment in Asia. Surgical indications have remained almost unchanged since the middle-path regimen was advocated by Tuli. Pedicle screws and Hartshill loop rectangle with sublaminar wires are the two common fixation techniques used.Materials and Methods:This retrospective observational study was performed at a single tertiary center. Patients were divided into two groups depending on the method of fixation (pedicle screw rod/Hartshill loop rectangle and sublaminar wires). All patients were evaluated preoperatively by X-rays and magnetic resonance imaging. Patients were assessed clinically by preoperative and postoperative neurology and Visual Analog Scale score and radiologically assessed by the K angle. These variables were separately compared in both the groups.Results:The functional outcomes of Hartshill loop rectangle and sublaminar wire fixation and that of pedicular screw fixation were comparable. Hartshill loop rectangle and sublaminar wire fixation was found to be more cost-effective.Conclusion:Hartshill loop rectangle and sublaminar wire fixation gets purchase over the posterior column structures alone when compared to pedicle screws which have a 3-column hold. However, when combined with meticulous neural decompression and skillful preparation of osteogenic bed with autologous strut grafting and additional onlay grafting, it gives overall adequate stabilization of the column with functional outcome comparable to pedicular screw and rod fixation with additional benefit of cost-effectiveness. Although Hartshill loop rectangle and sublaminar wire fixation is less commonly used now, it has a special place in the management of TB, especially in a resource-poor setting like some countries of Asia.

The Use of Metal Sublaminar Wires in Modern Growth-Guidance Scoliosis Surgery: A Report of 4 Cases and Literature Review

To avoid early fusion and allow residual growth of the spine in early onset scoliosis (EOS) treatment, growth-guided scoliosis surgery can be performed. Four patients with EOS are presented in which a growth-guidance instrumentation is used with sliding titanium (Ti) sublaminar cables. Residual growth of the spine can be preserved using metal sublaminar wiring; however, several drawbacks of this technique and type of material are illustrated. Four patients with progressive neuromuscular scoliosis were treated with a posterior stabilization. A fusionless growth-guidance instrumentation was used consisting of a combination of lumbar pedicle screws and sliding Ti sublaminar cables along cobalt chrome rods. In 2 cases, the described growth-guidance technique provided sufficient stability and correction of the curvature with preservation of growth. In 2 patients, the instrumentation failed due to upper thoracic sublaminar wire breakage. The ongoing abrasion of the rod-wire interface caused severe metallosis. In these cases, a debridement and revision surgery was performed with partial fusion of the spine. Growth-guidance techniques with sliding metal sublaminar wires seem to be a valuable solution for the preservation of spinal growth in EOS surgery. High curvatures, however, have a higher chance of failure and demand for more corrective strength and support of the instrumentation. The use of metal sublaminar wires in a "sliding" instrumentation can lead to early breakage and metallosis. 4, case series. Surgeons should be aware of possible complications associated with the use of metal laminar wires in spinal fusion and growth-guidance scoliosis surgery. The implementation of materials containing higher fatigue strength and lower friction properties (eg, UHMWPE wires) may avoid these potential complication risks.

Does Three-Dimensional Printed Patient-Specific Templates Add Benefit in Revision Surgeries for Complex Pediatric Kyphoscoliosis Deformity with Sublaminar Wires in Situ? A Clinical Study.

Study DesignCase-control study.PurposeTo evaluate the accuracy of three-dimensional (3D) printed patient-specific templates (PSTs) for placement of pedicle screws (PAs) in patients undergoing revision surgeries for complex kyphoscoliosis deformity with sublaminar wires in situ.Overview of LiteratureRevision kyphoscoliosis correction surgery in pediatric patients is a challenging task for the treating surgeon. In patients with sublaminar wires in situ, the native anatomical landmarks are obscured, thus making the freehand screw placement technique a highly specialized task. Hence, the concept of using PSTs for insertion of PAs in such surgeries is always intriguing and attractive.MethodsFive consecutive patients undergoing revision deformity correction with sublaminar wires in situ were included in this study. Patients were divided in two groups based on the technique of PA insertion. A total of 91 PAs were inserted using either a freehand technique (group A) or 3D printed templates (group B) (34 vs. 57). The placement of PAs was classified according to a postoperative computed tomography scan using Neo’s classification. Perforation beyond class 2 (>2 mm) was termed as a misplaced screw. The average time required for the insertion of screws was also noted.ResultsMean age, surgical time, and blood loss were recorded. The change in mean Cobb’s angle in both groups was also recorded. The difference in rates of misplaced screws was noted in group A and group B (36.21% vs. 2.56%); however, the mean number of misplaced PAs per patient in group A and group B was statistically insignificant (6.5±3.54 vs. 4.67±1.53, p=0.4641). The mean time required to insert a single PA was also statistically insignificant (120±28.28 vs. 90±30 seconds, p=0.3456).ConclusionsAlthough 3D printed PSTs help to avoid the misplacement of PAs in revision deformity correction surgeries with sublaminar wires in situ, the mean number of misplaced screws per patient using this technique was found to be statistically insignificant when compared with the freehand technique in this study.

Fusion rates support wired allograft combined with instrumented craniocervical fixation in the paediatric population

BackgroundOccipitocervical and atlantoaxial instability in the pediatric population is a rare and challenging condition to treat. Variable surgical techniques have been employed to achieve fusion. The study aimed to assess bony fusion with rigid craniocervical fixation using an allograft bone block to serve as scaffold for bony fusion.MethodsThis is a single center case series from a tertiary referral neurosurgical center. The series includes 12 consecutive pediatric patients with rigid craniocervical fusion between 2006 and 2014. The primary outcome was bony fusion as assessed by computed tomography and flexion-extension radiographs. The authors did not receive external funding for this study.ResultsTwelve patients (age 1–15 years) were operated with a median imaging follow-up time of 22 months (range 6–69 m). A modified Gallie fusion technique with a tightly wired allograft bone block was used in 10 of 13 procedures. One patient underwent re-fixation due to screw breakage. Eleven out of 13 procedures resulted in a stable construct with bony fusion. All 10 patients operated with the modified Gallie fusion technique with sublaminar wiring of allograft bone block had bony fusion. No post-operative complications of the posterior fixation procedure were noted.ConclusionsThe modified Gallie fusion technique with allograft bone block without post-operative immobilization achieved excellent fusion. We conclude there is no need to use autograft or BMPs in craniocervical fusion in the pediatric population, which avoids related donor-site morbidity.Level of evidenceLevel IV—case series; therapeutic.