A 540° posterior-anterior-posterior approach for 360° fused rigid severe cervical kyphosis: patient series

BACKGROUND Treatment of severe rigid 360° fused cervical kyphosis (CK) is challenging and often requires a combined approach for ankylosis release, establishment of sagittal balance, and fixation with fusion. OBSERVATIONS Four patients with iatrogenic 360° fused severe rigid CK (Cobb angle ≥40°) were enrolled for this retrospective analysis. All patients in the case series were female, with an average age of 27 years. All patients previously underwent posterior laminectomy/laminoplasty and cervical tumor resection when they were children (13–17 years). They underwent correction surgery with a 540° posterior-anterior-posterior approach. Preoperative and final follow-up radiography and computed tomography (CT) were used to evaluate kyphosis correction, internal fixation implants, and bone fusion. The preoperative and final follow-up average C2–7 Cobb angles were −32.4° ± 12.0° and 5.3° ± 7.1°, respectively. Preoperative and final follow-up CK angles averaged −47.2° ± 7.4° and −0.9° ± 16.1°, respectively. The mean correction angle was 46.3° ± 9.6°. At final follow-up, CT showed stable fixation and solid bone fusion. LESSONS The rare iatrogenic severe kyphosis with 360° ankylosis requires a combined approach. The 540° posterior-anterior-posterior approach can completely release the bony fusion, and the CK can be corrected using an anterior plate. This technique can achieve good results and is an effective strategy.

Postoperative alterations of sagittal cervical alignment and risk factors for cervical kyphosis in 124 Lenke 1 adolescent idiopathic scoliosis patients

Background This study aims to analyze postoperative changes of cervical sagittal curvature and to identify independent risk factors for cervical kyphosis in Lenke type 1 adolescent idiopathic scoliosis (AIS) patients. Methods A total of 124 AIS patients who received all-pedicle-screw instrumentation were enrolled. All patients were followed up for at least 2 years. The following parameters were measured preoperatively, immediately after the operation, and at the last follow-up: pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), global thoracic kyphosis (GTK), proximal thoracic kyphosis (PrTK), T1-slope, cervical lordosis (CL), McGregor slope (McGS), sagittal vertical axis (SVA), C2–7 SVA (cSVA), and main thoracic angle (MTA). Statistical analysis was performed to evaluate postoperative alterations of and correlations between the parameters and to identify risk factors for cervical kyphosis. Statistical significance was set at P < 0.05. Results After the operation, PrTK and T1-slope significantly increased (3.01 ± 11.46, 3.8 ± 10.76, respectively), cervical lordosis improved with an insignificant increase (− 2.11 ± 13.47, P = 0.154), and MTA, SS, and LL decreased significantly (− 33.68 ± 15.35, − 2.98 ± 8.41, 2.82 ± 9.92, respectively). Intergroup comparison and logistic regression revealed that preoperative CK > 2.35° and immediate postoperative GTK < 27.15° were independent risk factors for final cervical kyphosis, and △T1-slope < 4.8° for a kyphotic trend. Conclusions Postoperative restoration of thoracic kyphosis, especially proximal thoracic kyphosis, and T1-slope play a central role in cervical sagittal compensation. Preoperative CK, postoperative small GTK, and insufficient △T1-slope are all independent risk factors for cervical decompensation.

Halo traction combined with posterior-only approach correction for cervical kyphosis with Neurofibromatosis-1: minimum 2 years follow-up

Background Surgical management of cervical kyphosis in patients with NF-1 is a challenging task. Presently, anterior-only (AO), posterior-only (PO) and combined anterior-posterior (AP) spinal fusion are common surgical strategies. However, the choice of surgical strategy and application of Halo traction remain controversial. Few studies have shown and recommended posterior-only approach for cervical kyphosis correction in patients with NF-1. The aim of this study is to evaluate the safety and the effectiveness of halo Traction combined with posterior-only approach correction for treatment of cervical kyphosis with NF-1. Methods Twenty-six patients with severe cervical kyphosis due to NF-1 were reviewed retrospectively between January 2010 and April 2018. All the cases underwent halo traction combined with posterior instrumentation and fusion surgery. Correction result, neurologic status and complications were analyzed. Results In this study, cervical kyphosis Cobb angle decreased from initial 61.3 ± 19.7 degrees to postoperative 10.6 ± 3.7 degrees (P<0.01), with total correction rate of 82.7%, which consist of 45.8% from halo traction and 36.9% from surgical correction. JOA scores were improved from preoperative 13.3 ± 1.6 to postoperative 16.2 ± 0.7 (P<0.01). Neurological status was also improved. There was no correction loss and the neurological status was stable in mean 43 months follow-up. Three patients experienced minor complications and one patient underwent a second surgery. Conclusion Halo traction combined with PO approach surgery is safe and effective method for cervical kyphosis correction in patients with NF-1. A satisfied correction result, and successful bone fusion can be achieved via this procedure, even improvement of neurological deficits can also be obtained. Our study suggested that halo traction combined with PO approach surgery is another consideration for cervical kyphosis correction in patients with NF-1.

Surgical Outcomes of Selective Laminectomy for Patients With Cervical Kyphosis: A Retrospective Study of 379 Cases

Study Design A retrospective study. Objectives This study aimed to investigate the impact of cervical kyphosis on patients with cervical spondylotic myelopathy (CSM) following selective laminectomy (SL) regarding posterior spinal cord shift (PSS), and a number of SLs. Methods We evaluated 379 patients with CSM after SL. The patients with kyphosis (group K) were compared with those without kyphosis (group L). Moreover, groups K and L were divided into subgroups KS and KL (SLs ≤ 2) and LS and LL (SLs ≥ 3), respectively, and analyzed. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of the C2–C7 angle for satisfactory surgical outcomes, which was defined as a Japanese Orthopaedic Association (JOA) recovery rate of ≥50% in group KS. Results The average PSS (mm) in group K was smaller than that in group L (.8 vs 1.4; P < .01), but the JOA recovery rate was comparable between the 2 groups. Meanwhile, the mean PSS and JOA recovery rate (%) in group KS was lower than those in group KL, respectively (.3 vs 1.0; P < .01, 35.1 vs 52.3; P = .047). Moreover, the average PSS of group KS (.6) was smaller than those of other subgroups ( < .01). In addition, the ROC curve analysis showed that the C2–C7 angle of −14.5° could predict satisfactory surgical outcomes in group KS. Conclusion Selective laminectomy is not contraindicated for patients with kyphosis, but a larger number of SLs may be indicated for the patients with C2–C7 angles of ≤ −14.5°.

Increased Neck Tilt/T1 slope ratio may play an important role in patients with cervical kyphosis

Background In previous studies, we demonstrated that the T1 slope (T1s) is associated with clinical outcomes, but the results were not specific for individuals. A recent study suggested that an increased pelvic tilt (PT)/sacral slope (SS) ratio may play an important role in the degeneration of lumbar scoliosis and pathogenesis of lumbar spondylolisthesis. Therefore, we aimed to explore the role of neck tilt (NT)/T1s in patients with cervical kyphosis. Methods In total, the data of 36 kyphosis patients who underwent anterior cervical hybrid decompression and fusion (ACHDF) for multilevel (3 levels) cervical spondylotic myelopathy were retrospectively analyzed. The radiographic measurements included the T1s, NT, C2–7 Cobb angle, and C2–7 sagittal vertical axis (SVA). The visual analog scale (VAS) and neck disability index (NDI) scores were used to determine the clinical prognosis. Pearson’s correlation coefficient was calculated to assess the relationships among preoperative imaging examination parameters. Results The mean C2–7 Cobb angle was − 5.93 ± 3.00° before surgery, 9.67 ± 6.61° after surgery, and 7.91 ± 8.73° at the follow-up. The preoperative NT/T1s ratio was positively correlated with the ΔC2–7 Cobb angle (r = 0.358, p < 0.05) and negatively correlated with the preoperative C2–7 Cobb angle (r = -0.515, p < 0.01) and preoperative C2–7 SVA (r = -0.461, p < 0.01). The linear regression model indicated a positive correlation between the preoperative NT/T1s ratio and the ΔC2–7 Cobb angle (R2 = 0.122). Conclusions The preoperative NT/T1s ratio may be positively correlated with changes in postoperative cervical spine curvature (Cobb angle). The NT/T1s ratio may be worthy of increased attention among sagittal parameters.

Front-Back Cervical Deformity Correction by Anterior Cervical Discectomy and Fusion With Posterior Instrumentation: 2-Dimensional Operative Video

Front-back procedures for cervical deformity permit the correction of cervical kyphosis in the setting of unfused facets. Here, we highlight the operative treatment of a 65-yr-old female entailing a 4-level anterior cervical discectomy and fusion (ACDF) at C3-C4, C4-C5, C5-C6, and C6-C7 with hyperlordotic interbody implants, supplemented by a posterior C2-T2 instrumented fusion. The patient initially presented with symptoms of treatment-refractory neck pain while neurologically intact on examination. Her imaging demonstrated significant cervical kyphosis measuring 46° as the Cobb angle between C2 and C7 without neural compression. The patient consented to the procedure and publication of their image. After 2 d of traction, the operation proceeded with the patient initially in a supine position with dissection medial to the sternocleidomastoid muscle down to the vertebral bodies. Discectomies were performed at each level followed by installation of the interbody implants. After closure of this access wound, the patient was turned to a prone position for the posterior element of the operation. The posterior bony elements were exposed and a C2-T2 instrumented fusion performed. Postoperative imaging demonstrated improvement of her sagittal cervical curvature and the patient described improvement in her neck pain.