The Last Touched Vertebra on Supine Radiographs Can Be the Optimal Lower Instrumented Vertebra in Adolescent Idiopathic Scoliosis Patients

Postoperative Coronal Imbalance in Lenke 5C Adolescent Idiopathic Scoliosis: Evolution, Risk Factors, and Clinical Implications

OBJECTIVE

To explore the changes in coronal imbalance (CIB) in Lenke 5C adolescent idiopathic scoliosis (AIS) after posterior selective fusion surgery and determine their implications for surgical decision-making.

METHODS

One hundred twenty patients were categorized according to the preoperative coronal pattern (type A, coronal balance distance [CBD]<20 mm; type B, CBD≥20 mm and coronal C7 plumbline [C7PL] shifted to the concave side of the curve; type C, CBD≥20 mm and C7PL shifted to the convex side of the curve). CIB group (CIB+) was defined as having a CBD≥20 mm at the 2-year follow-up.

RESULTS

Compared to type A patients, the prevalence of postoperative CIB was higher in type C patients both immediately postoperative (22% vs. 38%, p<0.05) and at the final follow-up (5% vs. 29%, p<0.05), whereas type A patients showed a greater improvement in CBD (9 of 12 vs. 6 of 24, p<0.05) at the final follow-up. The majority of patients in all groups had recovered to type A at the final follow-up (96 of 120). The proximal Cobb-1 strategy reduced the incidence of postoperative CIB (1 of 38) at the 2-year follow-up, especially in preoperative type C patients. Multivariate logistic regression analysis revealed that type C and overcorrection of the thoracolumbar curve were risk factors for CIB at the 2-year follow-up (p=0.007 and p=0.026, respectively).

CONCLUSION

Patients with type C CIB in AIS exhibited unsatisfactory restoration, with 29% of them exhibiting CIB at the final follow-up. The selective fusion strategy of proximal Cobb-1 may reduce the risk of postoperative CIB especially when the preoperative coronal pattern is type C.

What Is the Role of Traction Test Radiographs in the Preoperative Planning of Adolescent Idiopathic Scoliosis?

Lower instrumented vertebra (LIV) selection is critical to avoid complications like adding-on. This study aims to determine the usefulness of the traction test (TR) in selecting the LIV during surgery for adolescent idiopathic scoliosis (AIS). We analyzed 42 AIS patients with Lenke 1 curves who had preoperative, postoperative, and at least 12-month follow-up X-rays, as well as preoperative side bending (SB) and TR radiograms. Neutral vertebra (NV), stable vertebra (SV), lower instrumented vertebra (LIV), and Cobb angles were identified and compared on all radiographic images. In 23 cases, the TR resulted in SV proximalization compared to the preoperative X-rays, while in 8 cases, SV-TR was more distal. This distalization occurred in 50% of Lenke 1C curves, where a greater correction of the distal curve was found. NV-TR was proximal to NV-preop in 9 cases, while NV-SB was proximal in 22 cases. LIV was proximal to SV-TR in 8 cases, while it was proximal to SV-preop in 22. One patient with LIV proximal to SV-TR developed adding-on. In conclusion, the TR is crucial in AIS preoperative planning as it provides information distinct from that of standard X-rays and SB: (1) it better assesses gravitational stability than rotational stability; and (2) choosing LIV equal to or proximal to SV-TR may prevent adding-on, except in 'flexible' Lenke 1C curves where LIV should be equal or distal to SV-preop.

Adolescent idiopathic scoliosis with concomitant spondylolysis: choice of fusion levels and evaluation of the outcomes obtained leaving the lytic level not instrumented

PURPOSE

7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.

METHODS

Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-year follow-up. Demographic data, instrumented levels, and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage, and pain levels were evaluated.

RESULTS

Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1-2 and 4 Lenke 3-6. 5 patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients, the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for 2, LIV was distal to the LTV; for 2, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.

CONCLUSION

The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis.

Selection of Optimal Lower Instrumented Vertebra for Adolescent Idiopathic Scoliosis Surgery

Adolescent idiopathic scoliosis (AIS) affects approximately 2% of adolescents across all ethnicities. The objectives of surgery for AIS are to halt curve progression, correct the deformity in 3 dimensions, and preserve as many mobile spinal segments as possible, avoiding junctional complications. Despite ongoing development in algorithms and classification systems for the surgical treatment of AIS, there is still considerable debate about selecting the appropriate fusion level. In this study, we review the literature on fusion selection and present current concepts regarding the lower instrumented vertebra in the selection of the fusion level for AIS surgery.

Surgical and Clinical Outcomes Associated With the Use of Barbed Sutures and Self-Adhering Mesh System and Polymeric Glue for Wound Closure in Multilevel or Revision Spinal Surgery: A Matched Cohort Comparative Study With Conventional Wound Closure Procedure

OBJECTIVE

Multilevel or revisional posterior spinal surgery is prone to infection and delayed wound healing, related with the wound closure time and suture strength. Knotless barbed suture is an innovative self-locking, multianchor suture. This study aims to evaluate the safety and efficacy of the knotless barbed suture and self-adhering mesh with polymeric glue in multilevel or revisional posterior spinal surgery.

METHODS

This is a single-center retrospective matched cohort study. Patients were divided into 2 groups based on the wound closure method: barbed suture group with novel wound closure, and conventional suture group with conventional wound closure, 1:1 matched by the level of surgery and sex, resulting in 120 subjects each. Total operation time and wound closure time were measured intraoperatively, and perioperative clinical outcome parameters including postoperative wound complication were investigated for the first 3 months postoperatively. The distribution of continuous variables was assessed for normality by Shapiro-Wilk test, then parametric or nonparametric tests were applied accordingly (paired t-test or Wilcoxon signed-rank test).

RESULTS

Wound closure time was significantly shorter with the novel barbed suture than with conventional suture in all subgroups divided by the level of spinal surgery: 3-5, 6-9, ≥ 10 levels (p < 0.001). The 2 groups showed no significant differences in surgical complications (p = 1.000). Specially, total operation time and wound-closing time were significantly shorter in revisional subgroup.

CONCLUSION

Absorbable knotless barbed suture and self-adhering mesh with polymeric glue can shorten spinal wound closure time with noninferiority in complications for multilevel or revisional spinal surgery.

Clinical Impact and Correlations of Odontoid Parameters Following Multilevel Posterior Cervical Fusion Surgery

OBJECTIVE

C2 slope (C2S), a cervical parameter mathematically approximated as T1 slope minus cervical lordosis (T1S-CL), predicts functional improvement in cervical deformity patients. Nonetheless, C2S is a positional parameter based only on the horizontal axis. The current study aims to introduce novel odontoid parameters and establish their relationships with patient-reported health-related quality of life (HRQoL).

METHODS

Lateral plain radiographs of 32 adults who underwent multilevel posterior cervical fusion were analyzed. The odontoid parameters included odontoid incidence (OI), C2S, odontoid tilt (OT), and gravity line-C2 distance (GL-C2), while the cervical parameters were the Cobb angle at C0-1, C1-2, C0-2, C2-7, C2-7 sagittal vertical axis (cSVA), T1 slope, and T1S-CL. The range of motion (ROM) of the occipito-atlantoaxial complex was measured in flexion and extension plain radiographs. Scores on the Neck Disability Index (NDI) and visual analogue scale (VAS) for axial neck (VASn) and arm pain were measured.

RESULTS

Compared to asymptomatic subjects, patients had larger C2S, cSVA, and T1S-CL, and smaller OT. Preoperatively, OI was significantly correlated with the ROM of C1-2 (r = 0.37, p < 0.05) and C0-2 (r = 0.46, p < 0.01). OT and C2S had significant correlations with the C0-1, C1-2, and C0-2 angles, GL-C2, and T1S-CL. Postoperative NDI scores were significantly correlated with OI (r = -0.40, p < 0.05) and OT (ρ = -0.37, p < 0.05). VASn was significantly correlated with GL-C2 (r = -0.35, p < 0.05).

CONCLUSION

The odontoid parameters were significantly correlated with established cervical parameters and HRQoL measures. OI is a constant parameter representing the individual's compensatory reservoir at the upper cervical spine.

Apical region correction and global balance: a 3-rods surgical strategy for the treatment of severe and rigid scoliosis

Background

The treatment of severe and rigid scoliosis is challenging. We developed a surgical strategy for severe and rigid scoliosis since 2014. This study aimed to retrospectively analyze the safety and efficacy of apical region correction and global balance with 3 rods as a surgical strategy for the treatment of severe and rigid scoliosis.

Methods

A retrospective study was performed for patients with severe and rigid scoliosis who underwent one-stage posterior corrective operation using the apical region correction and global balance with 3 rods surgical strategy between February 2014 and April 2020. The inclusion criteria were as follows: [1] Cobb angle > 90°; [2] flexibility < 30%; [3] a minimum 2-year follow-up. Patients were excluded if they had a history of traction or spinal surgery. Coronal and sagittal parameters, including Cobb angle, flexibility, apex vertebra translation, trunk shift (TS), thoracic kyphosis, lumbar lordosis, and sagittal vertical axis (SVA) were measured preoperatively, postoperatively and at the final follow-up. The Scoliosis Research Society 22-item questionnaire was administered preoperatively and at the final follow-up. During the operation, one slightly-bent short rod was placed into the concave side of apical region and correction was achieved by rod-rotation and distraction. Two pre-bent long rods were placed into both sides of the scoliosis and global balance was improved by leveling the proximal thoracic vertebrae and distal lumbar vertebrae.

Results

A total of 41 patients were included, with an average age of 20 years (range, 12–49 years) and follow-up of 34 months (range, 24–58 months). Postoperative correction rate was 53% for scoliosis. There were 14 patients with normal kyphosis before surgery, and 28 patients with normal kyphosis at the last follow-up. 88% of the patients (23/26) with preoperative coronal imbalance (TS > 20 mm) restored coronal balance at the final follow-up. 87% of the patients (14/16) with preoperative sagittal imbalance (SVA > 40 mm) restored sagittal balance at the final follow-up. The mean operation time and blood loss were 286 min and 941 mL, respectively. No patients had neurological complications or implant failure.

Conclusion

The surgical strategy of apical region correction and global balance with 3 rods is a safe and effective alternative for the surgical treatment of severe and rigid scoliosis.