Posterior Ligamentous Complex Research Articles

The trapeziometacarpal screw home torque mechanism as a clinical indicator of the posterior joint ligament complex integrity: A cadaveric investigation

BackgroundTo date, no clinical test provides specific objective information on the integrity of key ligamentous support of the trapeziometacarpal (TMC) joint. PurposeTo examine the potential of the TMC joint screw home torque mechanism (SHTM) in estimating the integrity of the posterior ligament complex in older adult population. Study DesignCross-sectional laboratory-based study. MethodsTwenty cadaver hands presenting with various degrees of TMC joint degradation ranging from none to severe osteoarthritis (OA) were radiographed in multiple positions to establish their degeneration status, joint mobility, and amount of dorsal subluxation at rest and with the application of the SHTM. Comparisons and correlations between degeneration status, joint mobility, subluxation reduction and ligament status obtained from dissection were calculated. ResultsNo significant statistical correlation was demonstrated with the subluxation reduction ratio of the SHTM and the combined ligament complex value however, a moderate negative correlation was found with dorsal central ligament injury at 21 Nm (τb = −0.46, p < 0.05) and 34 Nm (τb = −0.45, p < 0.05). A statistically significant reduction of radial subluxation of the TMC joint was observed between the subluxation at rest (M = 5.2, SD = 1.9) and subluxation with SHTM of 21 Nm (M = 4.4, SD = 2.4), t (19) = 3.2, p = 0.01, 95% CI [0.3, 1.4] and subluxation with SHTM of 34 Nm (M = 4.3, SD = 2.6), t (19) = 2.6, p = 0.02, 95% CI [0.2, 1.5]. ConclusionOur results did not support the SHTM as indicator of the TMC posterior ligament complex integrity however, it demonstrated 100% stabilization effect with non-arthritic TMC population.

The influence of ligament biomechanics on proximal junctional kyphosis and failure in patients with adult spinal deformity.

It is unknown whether the biomechanics of the posterior ligamentous complex (PLC) are impaired in individuals undergoing surgery for adult spinal deformity (ASD). Characterizing these properties may improve our understanding of proximal junctional kyphosis (PJK; defined as proximal junctional angle [PJA] of >10 deg from UIV-1 to UIV + 2), as well as proximal junctional failure (PJF; symptomatic PJK requiring revision). The purpose of this prospective observational study is to compare biomechanical properties of the PLC in individuals with ASD who do, and do not develop PJK or PJF within 1 year of spinal fusion surgery. Intraoperative biopsies of PLC were obtained from 32 consecutive patients undergoing spinal fusions for ASD (>4 levels). Ligament peak force, tensile stress, tensile strain, and elastic modulus (EM) were measured with a materials testing system. Biomechanical properties and tissue dimensions were correlated with age, gender, BMI, vitamin D level, osteoporosis, sagittal alignment, PJA and change in PJA preoperatively, within 3 months, and at 1 year postoperatively. Longer ligaments were associated with greater PJA change at 3 months (p = 0.04), and thinner ligaments were associated with greater PJA change at 1 year (r = 0.57, p = 0.01). Greater EM was associated with greater PJA at both 3 months and 1 year (p = 0.03). Five participants had a change in PJA of >10 1 year postoperatively, and three participants demonstrated PJF. EM was significantly higher in individuals who required revision surgery (p = 0.003), and ligament length was greater (p = 0.03). Preoperative sagittal alignment was not related to incidence of revision surgery (p > 0.10). The biomechanical properties of the PLC may be associated with higher risk for proximal failure. Ligaments that are longer, thinner, and less elastic are associated with higher postoperative PJA. Furthermore stiffer EM of the ligament is associated with the need for revision surgery.

Laminectomy with Laminar Reconstruction for Resection of Intradural Tumors at the Thoracolumbar Junction: A Technical Note

To introduce a new laminar reconstruction technique to treat primary spinal cord tumors. Laminectomy and laminoplasty techniques have been used to treat intradural spinal tumors. The advantage of laminectomy is its superior exposure of the spinal cord, whereas the advantage of laminoplasty is the reconstruction of the dorsal roof of the spine. In this technical note, we present a technique that combines a full laminectomy to maximize exposure, with a reconstructive technique to repair the lamina. This technique restores the posterior ligamentous complex to preserve spinal biomechanics. In this illustrative case, a 55-year-old woman with severe back pain radiating to the right lower extremity was found to have an intradural tumor at the T12-L1 spinal level. Given the transitional level of the spine and potentially high biomechanical stresses on the posterior support structures, we used a T12 laminectomy to resect the tumor, followed by reconstruction using miniplates. The patient tolerated the surgery well, without any complications. She was discharged home and was doing well during the 3 months follow-up visit. Appropriate patient consent was obtained. Laminectomy and laminar reconstruction allow maximum visualization and manipulation of the tumor, followed by restoration of the dorsal roof of the spinal ring, and is an effective technique for treating spinal cord tumors.

Analysis of factors associated with proximal junctional kyphosis after surgery for Lenke type 5 adolescent idiopathic scoliosis

Objective: To investigate the risk factors associated with the development of proximal junctional kyphosis (PJK) after posterior spinal fusion for in children with Lenke type 5 adolescent idiopathic scoliosis (AIS). Methods: It was a retrospective case-control study that included medical records of 98 children with Lenke type 5 AIS who underwent posterior orthopedic surgery under general anesthesia at the Honghui Hospital Affiliated to Xi'an Jiaotong University from January 2013 to December 2018. There were 23 males and 75 females with a mean age of (14.5±2.2) years (10-18 years). Patients were divided into PJK and non-PJK groups according to whether the posterior junctional angle (PJA) was greater than 10° and increased for more than 10° from the preoperative period at the the last follow-up. Univariate analysis was used to analyze the correlation of general data of the children with occurrence of PJK after the operation. Multivariate logistic regression analysis was used to analyze the risk factors of postoperative PJK. Results: There were 35 cases in the PJK group and 63 cases in the non-PJK group. The PJK and non-PJK groups were followed up for (35.6±7.3) months and (36.4±7.5) months, respectively, and the difference was not statistically significant (P=0.637). There was no statistically significant difference between the two groups in general data such as gender, age, and body mass index (all P>0.05), while there were statistically significant differences between the two groups in upper instrumented vertebrea (UIV) location and junctional area posterior ligamentous complex (PLC) injury (all P<0.05). The results of univariate analysis showed that UIV location at T10-T12, junctional area PLC injury, preoperative coronal thoracic curve (TC), preoperative and final follow-up PJA, and preoperative and final follow-up pelvic incidence-lumbarlordosis (PI-LL) were correlated with postoperative PJK (OR=2.50, 5.37, 0.92, 1.12, 1.32, 1.06, 3.35, all P<0.05). Multifactorial logistic regression analysis showed that UIV located at T10-T12 (OR=2.346, 95%CI: 1.582-3.481, P=0.001), junctional area PLC injury (OR=5.112, 95%CI: 1.283-20.418, P=0.023) and last follow-up PI-LL (OR=1.826, 95%CI: 1.558-24.745, P=0.012) were risk factors for the occurrence of postoperative PJK in children with Lenke type 5 AIS. Conclusions: Postoperative UIV fixation to the thoracolumbar segment, PLC injury in the junctional area and excessive postoperative PI-LL in children with Lenke type 5 AIS may be the risk factors for the occurrence of PJK after the operation. It is suggested that avoidance of UIV selection to the thoracolumbar segment, intraoperative protection of the PLC located near the UIV and restoration of a good PI-LL relationship may reduce the incidence of PJK.

Biomechanical evaluation of different semi-rigid junctional fixation techniques using finite element analysis

BackgroundProximal junctional failure is a common complication attributed to the rigidity of long pedicle screw fixation constructs used for surgical correction of adult spinal deformity. Semi-rigid junctional fixation achieves a gradual transition in range of motion at the ends of spinal instrumentation, which could lead to reduced junctional stresses, and ultimately reduce the incidence of proximal junctional failure. This study investigates the biomechanical effect of different semi-rigid junctional fixation techniques in a T8-L3 finite element spine segment model. MethodsFirst, degeneration of the intervertebral disc was successfully implemented by altering the height. Second, transverse process hooks, one- and two-level clamped tapes, and one- and two-level knotted tapes instrumented proximally to three-level pedicle screw fixation were validated against ex vivo range of motion data of a previous study. Finally, the posterior ligament complex forces and nucleus pulposus stresses were quantified. FindingsSimulated range of motions demonstrated the fidelity of the general model and modelling of semi-rigid junctional fixation techniques. All semi-rigid junctional fixation techniques reduced the posterior ligament complex forces at the junctional zone compared to pedicle screw fixation. Transverse process hooks and knotted tapes reduced nucleus pulposus stresses, whereas clamped tapes increased nucleus pulposus stresses at the junctional zone. InterpretationThe relationship between the range of motion transition and the reductions in posterior ligament complex and nucleus pulposus stresses was complex and dependent on the fixation techniques. Clinical trials are required to compare the effectiveness of semi-rigid junctional fixation techniques in terms of reducing proximal junctional failure incidence rates.

Quantitative Evaluation of the Influence of Posterior Malleolus Fracture and Fixation on the Rotational Stability of the Ankle

BackgroundThis study aimed to analyze quantitative correlation between the posterior malleolus fracture and fixation and the rotational stability of the ankle and to explore supplementary surgical indications for posterior malleolus fracture.MethodsTwenty fresh frozen cadaver specimens were selected and dissected. Based on the tibial insertion of the ligament complex, the model for the supination external rotation stage 3 ankle fracture with a posterior malleolar fragment and syndesmosis diastasis was created. The area threshold of the posterior tibial insertion of posterior malleolus fracture was biomechanically assessed and the difference of the antirotating ability stiffness of the ankle between simple posterior malleolus fixation and simple syndesmotic fixation was analyzed statistically.ResultsThe tibial insertion of posterior inferior tibiofibular ligament and inferior transverse tibiofibular ligament complex was relatively broad, and its width decreased as the distance from the joint line increased. Biomechanical analysis showed that: the threshold of posterior area of posterior malleolus fracture was 1/4S; posterior malleolus fixation provided better rotational stability than syndesmotic fixation (P < 0.01).ConclusionThe surgical indications for posterior malleolus fracture should consider simultaneously the restoration of the axial and rotational stability of the ankle. Simple posterior malleolus fracture fixation is recommended when the syndesmosis is unstable and the area ratio of posterior tibial insertion of posterior malleolus fracture is greater than or equal to 1/4. Syndesmotic fixation is proposed to restore and maintain the rotational stability of the ankle when the syndesmosis is unstable and the area ratio is less than 1/4. Regardless of the area ratio, the surgical indication only depends on the impact of the posterior malleolus fracture on the axial stability of tibiotalar joint, the involved articular surface area, and the displacement degree of posterior malleolus fragment, when the syndesmosis is stable.

The difference and clinical application of modified thoracolumbar fracture classification scoring system in guiding clinical treatment

ObjectiveThis study aimed to evaluate the feasibility of the modified thoracolumbar injury classification and severity score system in guiding clinical treatment.MethodsA retrospective study was conducted on a cohort of 120 patients with thoracolumbar fractures who were admitted to the Department of Spinal Surgery at Ningbo Sixth Hospital between December 2019 and June 2021. The study population consisted of 68 males and 52 females, with an average age of 36.7 ± 5.7 years. The severity of the fractures was assessed based on comprehensive scores incorporating fracture morphology, neurological function, posterior ligament complex integrity, and disc injury status. The evaluation was performed using the total score T, which guided the formulation of the clinical treatment strategy. Furthermore, the study compared the treatment options, imaging data, and clinical efficacy between two classification systems.ResultsThe analysis of 120 patients revealed no statistically significant difference in the total score or treatment method between the TLICS system and the modified TLICS system. However, the operation rate for the modified TLICS system (73.3%) was slightly lower compared to the TLICS system (79.2%). All patients were followed up for a mean duration of 19.2 ± 4.6 months, ranging from 11 to 27 months. At the last follow-up, the visual analogue scale score was 1.94 ± 0.52, and the modified Japanese Orthopaedic Association score was 28.8 ± 4.5, indicating a significant improvement compared to the scores obtained prior to treatment. The neurological status exhibited varying degrees of improvement. Notably, the anterior vertebral height ratio was 87.10 ± 7.17%, the sagittal index was 90.35 ± 7.72%, and the Cobb angle was 3.05 ± 0.97 degrees at the last follow-up. All these measurements demonstrated statistically significant differences compared to the values observed prior to treatment (P < 0.05). Additionally, two cases of pedicle screw breakage and seven cases of pedicle screw wear and cutting in the vertebral body were observed at the last follow-up, resulting in varying degrees of low back pain. However, no instances of rod breakage were reported.ConclusionThe modified TLICS system is a practical tool for the classification and assessment of thoracolumbar fractures. It has guiding significance for clinical treatment, and the operation rate was slightly lower than that of TLICS system.

Ultrasound Shear Wave Elastography Quantitatively Assesses Tension Changes of Supraspinous/Interspinous Ligament Complex Under Varied Loads.

Although interspinous and supraspinous ligaments of the lumbar spine are thought to contribute to spinal stability, little is known about their dynamic biomechanics. We demonstrate that shear wave elastography (SWE) offers a novel technique to noninvasively and quantitatively evaluate posterior spinous ligament complex functional loading and stiffness in different physiologic positions. We performed SWE and measured the length of the interspinous/supraspinous ligament complex in cadaveric torsos (N = 5), isolated ligaments (N = 10), and healthy volunteers (N = 9) to obtain length and shear wave velocity measurements. For cadavers and volunteers, SWE was utilized in 2 lumbar positions: lumbar spine flexion and extension. In addition, SWE was performed on isolated ligaments undergoing uniaxial tension to correlate shear wave velocities with experienced load. Average shear wave velocity in cadaveric supraspinous/interspinous ligament complexes increased for lumbar levels (23%-43%) and most thoracic levels (0%-50%). This corresponded to an average increase in interspinous distance from extension to flexion for the lumbar spine (19%-63%) and thoracic spine (3%-8%). Volunteer spines also demonstrated an average increase in shear wave velocity from extension to flexion for both the lumbar spine (195% at L2-L3 to 200% at L4-L5) and thoracic spine (31% at T10-T11). There was an average increase in interspinous distance from extension to flexion for the lumbar spine (93% at L2-L3 to 127% at L4-L5) and thoracic spine (11% at T10-T11). In isolated ligaments, there was a positive correlation between applied tensile load and average shear wave velocity. This study creates a foundation to apply SWE as a noninvasive tool for assessing the mechanical stiffness of posterior ligamentous structures and has potential applications in augmenting or evaluating these ligaments in patients with spine pathology. The interspinous and supraspinous ligaments are critical soft tissue supports of the posterior lumbar spine. Disruption of these structures is thought to have a negative impact on spinal stability in trauma and spine deformities.

A Retrospective Cohort Study of a Modified Open-Door Laminoplasty With Reconstruction of The Cervical Posterior Ligamental Complex to Decrease Axial Pain in Cervical Spondylotic Myelopathy

Background: Cervical spondylotic myelopathy patients with multiple segments are usually treated with surgery via the posterior approach, but expansive open laminoplasty (ELAP) often results in heavy, rigid, and acid bilge feelings in the neck, shoulder, and back, collectively known as axial symptoms. To evaluate the effect of modified posterior cervical ligament complex reconstruction and single-door laminoplasty with titanium plate fixation on postoperative axial symptoms in patients. Methods: We conducted a retrospective study including 132 cases of cervical spondylotic myelopathy at our institute from June 2016 to March 2018. The patients who conformed to the inclusion criteria were randomly divided into two different surgical groups by by the surgeons. Gender, age, operation time, intraoperative blood loss, post-operative drainage volume, and follow-up time, Visual analogue scoring (VAS), cervical curvature index (CCI) and the cross-sectional area of the posterior cervical muscles of the two groups were recorded. Results: There was statistical significance in the incidence of axial pain 3 months after surgery (P = 0.001), 6 months after surgery (P = 0.006), and 1 year after surgery (P = 0.015). Compared to group b, the VAS score in group A was decreased one month (P &lt;0.0001), 3 months (P=0.0001), 6 months(P=0.0076), and 1 year(P=0.0085) after surgery. The CCI and the posterior cervical muscle area also differed significantly between the two groups (P &lt; 0.0001). Conclusions: Modified single open-door laminoplasty could relieve cervical axial pain in patients with cervical spondylotic myelopathy

ROLES OF SPINAL OSTEOTOMIES ON CORRECTION OF POST-TRAUMATIC THORACOLUMBAR KYPHOSIS

Thoracolumbar (T–L) fracture may create focal kyphosis accompanied by altered sagittal alignment, instability and potential neurological deficits. Surgical intervention for post-traumatic T–L kyphosis aims to restore sagittal balance, release compromised neural structures, and to improve the symptoms related to the malalignment. It is best indicated when there is a progression of kyphotic deformity, and/or when there are new or progressive neurological deficits. A kyphotic deformity [Formula: see text] is susceptible to persistent chronic pain in the kyphotic region and surgical correction is often required. Those with posterior ligamentous complex injury may also warrant surgical correction as there is a higher risk of kyphosis progression. A number of surgical procedures could be employed to correct post-traumatic T–L kyphosis. Spinal osteotomies are often needed to improve global, sagittal or coronal balance including in the late and fixed post-traumatic kyphosis. Based on different extent of focal kyphosis and global malalignment, surgical options may include posterior column osteotomy (PCO), pedicle subtraction osteotomy (PSO), disc-bone osteotomy (DBO), vertebral column resection (VCR) or closing opening wedge osteotomy (COWO). The type of spinal osteotomy utilized to correct post-traumatic T–L kyphosis should be chosen based on the severity of the deformity, the alignment of the spine, and the surrounding structures. In the meantime, potential complications should be reduced with novel techniques and proper constructs. When all associated factors are considered, surgical correction composing a suitable spinal osteotomy can be a beneficial and rewarding procedure for patients with post-traumatic T–L kyphosis.

Bone-to-Bone Ligament Preserving Laminoplasty with Ultrasonic Osteotome Assistance for Intraspinal Tumors: A Technical Note and Clinical Follow-Up.

Laminectomy has been widely used for intraspinal tumor resection. However, the tilted spinous process and narrow lateral laminae of the thoracic spine along with the hypertrophic ligamentum flavum of the lumbar spine pose certain problems for the laminae removal of the traditional laminectomy. We improved the laminectomy method with ultrasonic osteotome to treat thoracolumbar tumors and assessed its safety and superiority. A retrospective analysis was performed in 86 patients with thoracolumbar (T4-L5) spinal tumors treated by resection, including 44 with the lamina removed using the traditional method and 42 with the lamina removed using the bone-to-bone ligament preserving (BLP) laminoplasty, which preserves the posterior ligament complex. Age, sex, and tumor size, location, and depth were compared between the two groups. The length of incision and bone window, time to remove the vertebral lamina, and epidural effusion volume were recorded at 2 weeks after surgery in the two groups. Postoperative reexamination by magnetic resonance imaging (MRI) at 2 weeks and 3 months after surgery was compared with preoperative MRI to assess the change in vertebral lamina displacement. There were no statistical differences in age, sex, and tumor size, depth, or location between the two groups. The BLP laminectomy did not increase the risk of dural, spinal cord, or nerve injuries. The difference between the incision and tumor length, as well as the difference between the bone window and tumor length in the BLP laminectomy group, were smaller than those in the traditional laminectomy group, and the BLP laminectomy took less time compared to that of the traditional laminectomy (p < 0.05). There was no significant difference in the volume of epidural effusion between the two groups at 2 weeks postoperatively, or in the displacement of the returned vertebral plate observed in sagittal and axial positions. The same was true for the displacement at 3 months postoperatively in the axial position. However, the sagittal displacement in the BLP laminectomy group was smaller than that in the traditional laminectomy group (p < 0.05). The BLP laminectomy is safe for the resection of thoracolumbar spinal canal tumors. It is less traumatic and faster, with less displacement of the returned lamina, resulting in a stable repair of the spine.

Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture

ObjectiveThough magnetic resonance imaging (MRI) is the primary modality of investigation for determining the extent of PLC injuries in lower lumbar fractures (L3-L5), the reliability of computed tomography (CT) has not been well defined. The main objective of this study is to analyze the diagnostic accuracy of combined CT findings for detecting posterior ligamentous complex injury in patients with lower lumbar fractures. MethodsWe retrospectively analyzed data from 108 patients who presented with traumatic lower lumbar fractures. CT parameters like loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interlaminar distance (ILD), interspinous distance (ISD), supraspinous distance (SSD), interpedicular distance (IPD), canal compromise, facet joint diastasis in axial images (FJDA) and sagittal images (FJDS), presence of lamina and spinous process fracture were calculated using axial and sagittal CT images. The presence or absence of PLC injury was determined using MRI as a reference standard. ResultsAmong 108 patients PLC injury was identified in 57 (52.8%). On univariate analysis local kyphosis, retropulsion of fracture fragment, ILD, IPD, FJDS, FJDA, and the presence of spinous process fracture were found to be significant (P < 0.05) in predicting PLC injury. Whereas on multivariate logistic regression analysis, FJDS (P= 0.039), and FJDA (P= 0.003) were found to be variables independently associated with PLC injury. ConclusionAmong the various CT parameters, facet joint diastasis (FJDS > 4.2 mm and FJDA > 3.5 mm) is the most reliable factor in determining PLC injury.

Unilateral biportal endoscopic supralaminar, posterior spinous process sparing approach for en bloc cervical laminectomy in case of cervical osteochondroma causing myelopathy: A case report

Background ContextCervical osteochondroma is a rare cause of myelopathy. Traditional treatment is open laminectomy with or without fusion. There is limited literature on unilateral bi-portal endoscopic en-bloc resection of cervical osteochondroma. Study DesignWe describe a case of a 39-year-old male diagnosed with cervical compressive myelopathy. The pathologic site is located on the ventral surface of C4 lamina. Herein we describe a step-by-step method of unilateral biportal endoscopy (UBE) en-bloc resection of extra-dural sublaminar osteochondroma for patient who had cervical myeloradiculopathy. Spinous process sparing osteotomy was performed to conserve the spinous process and supraspinous ligament.. Outcome MeasuresThe patient was successfully treated via UBE and the operative time was 50 minutes with no intra-operative complications. Patient symptoms improved in the immediate postoperative period and by 3 months he regained fine motor functions of hand. ConclusionsUnilateral biportal endoscopic en bloc cervical laminectomy can effectively decompress cervical spine and remove posterior benign cervical tumor. UBE preserves musculature and posterior ligamentous complex and thus reduces postoperative neck pain and postlaminectomy kyphosis.

Evaluation of Posterior Ligamentous Complex Injury in Thoracolumbar Burst Fractures: Correlation Analysis of CT and MRI Findings.

The goal of this study is to perform correlation analysis of Computed tomography (CT) and magnetic resonance imaging (MRI) results in posterior ligament complex (PLC) injury and define the morphological traits of thoracolumbar (TL) burst fractures connected to PLC injury. Forty patients with surgically repaired TL burst fractures between January 2013 and December 2020 were retrospectively analyzed. The patients were split into two groups for comparison based on MRI (Group P: patients with a confirmed or suspected PLC injury; Group N: patients with PLC injury denied). The radiographic morphological examination based on CT scans and clinical evaluation was performed and compared between two groups. The thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores, and the number of patients with neurological impairments were considerably greater in Group P. Loss of height of the fracture (loss height), local kyphosis of the fracture (local kyphosis), and supraspinous distance were significantly higher in Group P and significantly associated with PLC injuries indicating severe vertebral body destruction and traumatic kyphosis in multivariate logistic analysis [odds ratio: 1.90, 1.06, and 1.13, respectively]. Cutoff value for local kyphosis obtained from the receiver operating characteristic curve was 18.8. If local kyphosis is greater than 18.8 degrees on CT scans, we should take into account the probability of the highly damaged burst fracture associated with PLC injury. In this situation, we should carefully assess MRI to identify the spinal cord injury or spinal cord compression in addition to PLC injury because these instances likely present with neurological abnormalities.

Role of magnetic resonance imaging features in diagnosing and localization of disc rupture related to cervical spinal cord injury without radiographic abnormalities.

A retrospective study. Traumatic cervical spinal cord injury (TSCI) is often associated with disc rupture. It was reported that high signal of disc and anterior longitudinal ligament (ALL) rupture on magnetic resonance imaging (MRI) were the typical signs of ruptured disc. However, for TSCI with no fracture or dislocation, there is still difficult to diagnose disc rupture. The purpose of this study was to investigate the diagnostic efficiency and localization method of different MRI features for cervical disc rupture in patient with TSCI but no any signs of fracture or dislocation. Affiliated hospital of University in Nanchang, China. Patients who had TSCI and underwent anterior cervical surgery between June 2016 and December 2021 in our hospital were included. All patients received X-ray, CT scan, and MRI examinations before surgery. MRI findings such as prevertebral hematoma, high-signal SCI, high-signal posterior ligamentous complex (PLC), were recorded. The correlation between preoperative MRI features and intraoperative findings was analyzed. Also, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these MRI features in diagnosing the disc rupture were calculated. A total of 140 consecutive patients, 120 males and 20 females with an average age of 53 years were included in this study. Of these patients, 98 (134 cervical discs) were intraoperatively confirmed with cervical disc rupture, but 59.1% (58 patients) of them had no definite evidence of an injured disc on preoperative MRI (high-signal disc or ALL rupture signal). For these patients, the high-signal PLC on preoperative MRI had the highest diagnostic rate for disc rupture based on intraoperative findings, with a sensitivity of 97%, specificity of 72%, PPV of 84% and NPV of 93%. Combined high-signal SCI with high-signal PLC had higher specificity (97%) and PPV (98%), and a lower FPR (3%) and FNR (9%) for the diagnosis of disc rupture. And combination of three MRI features (prevertebral hematoma, high-signal SCI and PLC) had the highest accuracy in diagnosing traumatic disc rupture. For the localization of the ruptured disc, the level of the high-signal SCI had the highest consistency with the segment of the ruptured disc. MRI features, such as prevertebral hematoma, high-signal SCI and PLC, demonstrated high sensitivities for diagnosing cervical disc rupture. High-signal SCI on preoperative MRI could be used to locate the segment of ruptured disc.

Technical note–in situ laminotomy: preserving posterior tension band in surgery of pediatric multilevel spinal tumor

BackgroundLaminotomy has been introduced in surgical practice to reduce complications of laminectomy after surgery of tumors in the spinal canal. However, the posterior ligament complex, which is routinely interrupted to remove the laminoplasty segment and gain access to the spinal canal, has a tendency not to heal and can lead to progressive kyphosis and collapse.Case presentationA 5-month-old boy affected by a thoracolumbar extradural tumor extending along seven spinal levels was operated on. The tumor was exposed and completely resected by a one-piece laminotomy with preservation of the integrity of the posterior tension band at both extremities. After 1-year radiological examination ruled out spinal deformity.ConclusionThe technique herein presented, which we named in situ laminotomy, allows to fully preserve the posterior tension band without reducing the exposure of the spinal canal in multilevel tumors. Additionally, the technique makes also the reconstruction of the spine elements very easy and rapid. However, longer follow-up is necessary to prove the effectiveness of this procedure in preventing long-term deformity and instability.

Hooks Versus Pedicle Screws at the Upper Instrumented Level: An In Vitro Biomechanical Comparison.

Controlled laboratory study. The aim was to compare motions at the upper instrumented vertebra (UIV) and supra-adjacent level (UIV+1) between two fixation techniques in thoracic posterior spinal fusion constructs. We hypothesized there would be greater motion at UIV+1 after cyclic loading across all constructs and bilateral pedicle screws (BPSs) with posterior ligamentous compromise would demonstrate the greatest UIV+1 range of motion. Proximal junctional kyphosis is a well-recognized complication following long thoracolumbar posterior spinal fusion, however, its mechanism is poorly understood. Twenty-seven thoracic functional spine units were randomly divided into three UIV fixation groups (n=9): (1) BPS, (2) bilateral transverse process hooks (TPHs), and (3) BPS with compromise of the posterior elements between UIV and UIV+1 (BPS-C). Specimens were tested on a servohydraulic materials testing system in native state, following instrumentation, and after cyclic loading. functional spine units were loaded in flexion-extension (FE), lateral bending, and axial rotation. After cyclic testing, the TPH group had a mean 29.4% increase in FE range of motion at UIV+1 versus 76.6% in the BPS group ( P <0.05). The BPS-C group showed an increased FE of 49.9% and 62.19% with sectioning of the facet joints and interspinous ligament respectively prior to cyclic testing. BPSs at the UIV led to greater motion at UIV+1 compared to bilateral TPH after cyclic loading. This is likely due to the increased rigidity of BPS compared to TPH leading to a "softer" transition between the TPH construct and native anatomy at the supra-adjacent level. Facet capsule compromise led to a 49.9% increase in UIV+1 motion, underscoring the importance of preserving the posterior ligamentous complex. Clinical studies that account for fusion rates are warranted to determine if constructs with a "soft transition" result in less proximal junctional kyphosis in vivo .

Role of Posterior Longitudinal Ligament Complex in Spinal Deformity Secondary to Surgical Resection of the Intradural Tumor.

In most cases, complete resection of the intradural tumor is accompanied by long-term neurological complications. Postoperative spinal deformity is the most common complication after surgical resection of intradural tumors, and posterior longitudinal ligament complex (PLC) plays an important role in postoperative spinal deformity. In this study, we investigated the role of PLC in spinal deformity after the surgical treatment of intradural tumors. We analyzed the data of 218 consecutive patients who underwent intradural tumor resection from 2000 to 2018 in this retrospective study. Before 2010, patients underwent laminoplasty without maintaining the integrity of PLC (laminoplasty group, n=155). After 2010, patients performed single-port laminoplasty to maintain the integrity of PLC (laminoplasty retain posterior ligament complex group, n=63). The score of quality of life, painful cortex, spinal cord movement, progressive kyphosis or scoliosis, perioperative morbidity, and neurological results were analyzed in the laminoplasty group and laminoplasty retain posterior ligament complex group. The distributed variable was shown as mean ± standard deviation and an independent t-test or one-way analysis of variance was calculated. There are 155 patients (71.1%) included in the laminoplasty group, and 63 patients (28.9%) in the laminoplasty retain posterior ligament complex group. The average age of patients was 42 ± 2.3 years, and the average modified McCormick score was 2. There were 158 (72.4%) patients with intramedullary tumors and 115 (52.7%) patients with extramedullary tumors. The length of hospital stays (8 days vs. 6 days; p=0.023) and discharge to inpatient rehabilitation (48.4% vs. 26.9%; p=0.012) were significantly lower in the laminoplasty retain posterior ligament complex group than the laminoplasty group. There was no significant difference in the risk of progressive deformity between the two groups at 18months after surgery (relative risk 0.12; 95% confidence interval [CI] 0.43-1.25; p=0.258) and at 20months after surgery (relative risk 0.24; 95% CI 0.21-2.1). Laminoplasty retains posterior ligament complex showed no impact on the spinal deformities compared with laminoplasty, but significantly improved the postoperative spinal activity, alleviated pain symptoms, and reduced hospital recovery time.

Imaging parameters and clinical significance of posterior ligament complex injury in thoracolumbar fracture.

This study aims to investigate whether the combination of radiographs and computed tomography (CT) images can be used as an alternative means of magnetic resonance imaging examination or a preliminary screening method before examination, so as to improve the accuracy of determining the degree of posterior ligament complex injury in thoracolumbar fracture patients. From May 2011 to May 2019, the patients with thoracolumbar fracture were collected. A total of 150 patients were enrolled. The reference standard was 1.5T magnetic resonance imaging examination and lipid suppression sequence was applied. All radiographs and CT imaging results were measured in the Picture Archiving and Communication System workstation. The upper endplate angle and lower endplate angle, the percentage of vertebral height drop, the difference of inter-spinous process distance on CT images and the translation distance were statistically significant between the 2 groups (P < .05). Receiver operating characteristic curve showed that the diagnostic performance was excellent (all area under the curve > 0.7). To sum, the results showed that endplate angle + inter-spinous process distance on CT images combination had relatively high-quality diagnostic value for posterior ligamentous complex injury in thoracolumbar fracture patients.

Full-Endoscopic Decompression for Thoracic Ossification of the Ligamentum Flavum Combined with Dural Ossification

Ossification of the ligamentum flavum (OLF) can result in spinal stenosis. Thoracic spinal cord compression due to spinal stenosis is a common cause of progressive thoracic myelopathy in Asian countries. The incidence of complications is high in open decompression surgeries for thoracic OLF. With dural ossification (DO), the risk of complications is even higher in thoracic OLF. We introduce a full-endoscopic decompression surgery for thoracic OLF combined with DO under local anesthesia. Hemilaminectomy is performed using a high-speed burr under the endoscopy first, and then decompression of the contralateral spinal canal is completed using an "over the top" technique. DO resection uses the eggshell technique; after the base of the DO is cut from the lamina, forceps or lamina rongeurs are typically used for removal. The dural defect left after resection does not need repair. Neurological function was improved, and no complications such as hematoma or neck pain occurred. On imaging, no pseudodural cyst, cerebrospinal fluid leakage, or wound complications were observed after the operation. Endoscopic surgery causes less damage to the posterior ligament complex, so no cases of persistent back pain complaints or secondary internal fixation requirements were found in this study. Full-endoscopic decompression can achieve good imaging and clinical effects in the treatment of thoracic OLF with DO.