Dorsal Column Research Articles

Outcomes of acetabular fractures.

Acetabular fractures are prognostic relevant fractures in terms of function and daily activities. Open reduction and internal fixation (ORIF) is still the gold-standard in treating these injuries. Over recent years, several reports are dealing with outcome evaluations but have the main disadvantage of combining several fracture types., Thus, it remains unclear to discuss a fracture-based prognosis. This analysis evaluated fracture-type specific results in terms of clinical and radiological outcome. Analyzing elementary fracture types, pure transverse and isolated posterior column fractures are associated with relevant functional impairments. Except for posterior column fractures all other elementary fracture types were associated with degenerative changes in nearly 20%. Anterior column fractures seems to be "forgiving fractures" as they are associated with the longest median time until hip joint failure occurs. In associated fracture-types T-shaped fractures are still demanding fractures with < 60% anatomic reductions and a high rate of functional impairments. All associated fracture types are associated with a relevant rate of secondary degeneration of the hip joint between 20 and 40% of patients. Early hip joint failure (THR, Femoral head necrosis, severe heterotopic ossification) within the 1st year is frequently seen in associated posterior column and posterior wall fractures, but with a relative good prognosis, if the joint survived the first year after ORIF. The highest survival rates of the hip joint is observed with ABC-fractures. Also, these fractures seem to be "forgiving fractures".

Relationship of Fracture Morphological Characteristics with Posterolateral Corner Injuries in Hyperextension Varus Tibial Plateau Fractures.

Hyperextension varus tibial plateau fracture (HVTPF) is known to present with concomitant injuries to the posterolateral corner (PLC). However, the exact rate and characteristics of these injuries remain unclear. The primary objective of this study was to explore the rate and characteristics of PLC injuries in HVTPFs. The secondary objective was to investigate the relationship between the fracture morphological features and the associated PLC injuries. Patients with HVTPFs were subdivided into 2 groups: group I (without fracture of the posterior column cortex) and group II (with fracture of the posterior column cortex). Fracture characteristics were summarized qualitatively based on fracture maps and quantitatively based on the counts of morphological parameters. Knee ligamentous and meniscal injuries were assessed using magnetic resonance imaging. The association between fracture characteristics and PLC injuries was analyzed. We included a total of 50 patients with HVTPFs in our study: 28 in group I and 22 in group II. The rate of PLC injuries was 28.6% in group I and 27.3% in group II. In group I, patients with PLC injuries showed fracture lines closer to the anterior rim of the medial plateau and had smaller fracture areas. Furthermore, 6 of the 8 patients with PLC injuries in group I also had posterior cruciate ligament injuries. The rate of PLC injuries is relatively high in HVTPFs. In HVTPFs without fracture of the posterior column cortex, a small fracture area strongly suggests an accompanying PLC injury, and PLC injury is frequently combined with posterior cruciate ligament injury. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

AI-assisted 3D analysis of grasping and reaching behavior of squirrel monkeys during recovery from cervical spinal cord injury

We have previously demonstrated that machine learning-based video analysis, conducted via DeepLabCut, is more sensitive for detecting subtle deficits in hand grasping behavior than traditional end-point performance assessments. This superiority was observed in a nonhuman primate (NHP) model of cervical spinal cord injury, specifically a dorsal column lesion (DCL). The current study aims to further characterize the kinematic aspects of the deficits in hand reaching, grasping, and retrieving behavior from a 3D perspective following a DCL. Squirrel monkeys were trained to retrieve sugar pellets from eight wells, which were located either on a flat plate or a raised tube with varying well depths. This setup was designed to require coordinated finger movements during the task. Immediately after the DCL, the animals exhibited measurable behavioral deficits. These were characterized by significant increases in grasping speed squared and trial completion time, markedly widened movement trajectories of individual fingers, and abnormalities in inter-finger distance and orientation. Increased task difficulty was associated with more pronounced behavioral deficits. By three months post-DCL, video-based measurements indicated no significant recovery, even though global end-point performance had returned to baseline levels. Our findings demonstrate that deprivation of tactile information results in impaired dexterous hand behavior involving coordinated finger movements, and the impairment is sustained for 20 weeks. This spinal cord injury (SCI) model, along with DeepLapCut analysis, provides a valuable platform for separately evaluating sensory and motor functions and their contributions to dexterous hand behavior and may be used for evaluating therapeutic interventions using more sensitive behavioral outcome readouts.

Outcomes Transverse Acetabular Fractures Treated with Posterior Column Plate Fixation and Anterior Column Screw Fixation

Outcomes Transverse Acetabular Fractures Treated with Posterior Column Plate Fixation and Anterior Column Screw Fixation

Experiences with the infra-acetabular screw placement technique in acetabular fracture surgery

To investigate the application experiences and effectiveness of the infra-acetabular screw (IAS) placement technique in acetabular fracture surgery. A clinical data of 34 patients with complex acetabular fractures with anterior and posterior columns separation, who were admitted between January 2019 and October 2023 and treated with IAS fixation, was retrospectively analyzed. There were 23 males and 11 females with an average age of 55.3 years (range, 18-78 years). The acetabular fractures caused by traffic accident in 20 cases, falling from height in 12 cases, crushing injury in 1 case, and bruising with a heavy object in 1 case. According to the Letournel-Judet classification, there were 7 cases of anterior column fracture, 8 cases of anterior wall/column plus posterior hemi-transverse fracture, 2 cases of T-shaped fracture, and 17 cases of both-column fracture. The time from injury to surgery was 4-21 days (mean, 8.6 days). The time of IAS placement and the intraoperative blood loss were recorded. After surgery, the X-ray film and CT scan were re-examined, and the modified Matta score was used to assess the quality of fracture reduction. The trajectory of IAS in the channel was analyzed based on CT scan, and the screw length was measured. During follow-up, the fracture healing was observed and the hip function was assessed according to the modified Merle d'Aubigné-Postel scoring system at last follow-up. The IAS was successfully implanted in all 34 patients. The length of IAS ranged from 70 to 100 mm (mean, 86.2 mm). The time of IAS placement ranged from 10 to 40 minutes (mean, 20.7 minutes). The intraoperative blood loss ranged from 520 to 820 mL (mean, 716.8 mL). All patients were followed up 8-62 months (mean, 21.8 months). After surgery, 4 patients developed lateral femoral cutaneous nerve injury, 2 developed popliteal vein thrombosis of the lower extremity, 3 developed incision infection, and no surgical complication such as arteriovenous injury or obturator nerve palsy occurred. At last follow-up, the hip function was rated as excellent in 14 cases, good in 13 cases, fair in 4 cases, and poor in 3 cases according to the Merle d'Aubigné-Postel scoring system, with an excellent and good rate of 79.41%. Imaging re-examined showed that the quality of fracture reduction was rated as excellent in 9 cases, good in 19 cases, and poor in 6 cases according to the modified Matta score, with an excellent and good rate of 82.35%; and 25 (73.53%) IAS trajectories were located in the channel. All fractures obtained bony union, and the healing time was 12-24 weeks (mean, 18 weeks). During follow-up, there was no loosening or fracture of the plate and screws. IAS placement technique can effectively strengthen internal fixation and prevent fracture re-displacement, making it a useful adjunct for treating complex acetabular fractures with anterior and posterior columns separation.

Anatomical Posterior Acetabular Plate Versus Conventional Reconstruction Plates for Acetabular Posterior Wall Fractures: A Comparative Study.

Background: Functional recovery following the surgical fixation of acetabular posterior wall fractures remains a challenge. This study compares outcomes of posterior wall fracture reconstruction using an anatomical posterior acetabular plate (APAP) versus conventional reconstruction plates. Methods: Forty patients with acetabular fractures involving the posterior wall or column underwent surgery, with 20 treated using APAPs (APAP group) and 20 with conventional pelvic reconstruction plates (control group). Baseline patient characteristics, intraoperative blood loss and time, reduction quality, postoperative function, and postoperative complications were compared using appropriate non-parametric statistical tests. A general linear model for repeated measures analysis of variance was employed to analyze trends in functional recovery. Results: No significant differences were observed in baseline characteristics. APAP significantly reduced surgical time by 40 min (186.5 ± 51.0 versus 225.0 ± 47.7, p =0.004) and blood loss (695 ± 393 versus 930 ± 609, p = 0.049) compared to conventional plates. At 3 and 6 months following surgery, the APAP group exhibited higher functional scores (modified Merle d'Aubigné scores 10 ± 1.8 versus 7.8 ± 1.4, p < 0.001; 13.4 ± 2.8 versus 10.1 ± 2.1, p = 0.001), converging with the control group by 12 months (modified Merle d'Aubigné scores 14.2 ± 2.6 versus 12.7 ± 2.6, p = 0.072; OHS 31.6 ± 12.3 versus 30.3 ± 10.1, p = 0.398). Radiologically, the APAP group demonstrated superior outcomes (p = 0.047). Complication and conversion rates to hip arthroplasty did not significantly differ between groups (10% versus 15%, p = 0.633). Conclusions: The use of an APAP in reconstructing the posterior acetabulum significantly reduces surgical time, decreases intraoperative blood loss, and leads to earlier functional recovery compared to conventional reconstruction plates. The APAP provides stable fixation of the posterior wall and ensures the durable maintenance of reduction, ultimately yielding favorable surgical outcomes.

The Lateral Corticospinal Tract Sign: An MRI Marker for Amyotrophic Lateral Sclerosis.

Background Radially sampled averaged magnetization inversion-recovery acquisition (rAMIRA) imaging shows hyperintensity in the lateral corticospinal tract (CST) in patients with motor neuron diseases. Purpose To systematically determine the accuracy of the lateral corticospinal tract sign for detecting patients with amyotrophic lateral sclerosis (ALS) at rAMIRA MRI. Materials and Methods This study included prospectively acquired data from participants in ALS and other motor neuron disease imaging studies at the University Hospital Basel, Switzerland. All participants underwent 3-T axial two-dimensional rAMIRA imaging at four cervical intervertebral disk levels. The lateral CST sign was defined as spinal cord white matter hyperintensity dorsolateral to the anterior horns, with higher signal intensity than in the dorsal columns on axial rAMIRA images. Marker accuracy was assessed in a study data set and in an independent validation data set. Postmortem rAMIRA imaging and histopathologic analysis were performed in one participant who died during the study. Results Participants with ALS (study data set: 38 participants [mean age, 61 years; IQR, 15 years], 22 male participants; validation data set: 10 participants [mean age, 61 years; IQR, 21 years], seven male participants), post-polio syndrome (study data set: 25 participants [mean age, 68 years; IQR, 8 years], 12 male participants), spinal muscular atrophy (study data set: 10 participants [mean age, 43 years; IQR, 14 years], eight male participants; validation data set: five participants [mean age, 38 years; IQR, 19 years], two male participants), and healthy control participants (study data set: 60 participants [mean age, 57 years; IQR, 20 years], 36 male participants; validation data set: 10 participants [mean age, 44 years; IQR, 17 years], seven male participants) were included. The sensitivity and specificity of rAMIRA for ALS were 60% (23 of 38) and 97% (91 of 94) in the study data set and 100% (10 of 10) and 93% (14 of 15) in the validation data set, respectively. Histopathologic analysis showed distinct loss of myelinated axons in the localization of the hyperintensities observed at rAMIRA imaging performed in situ and after organ extraction. Conclusion The recently defined marker at rAMIRA MRI may be a promising tool for assessing upper motor neuron degeneration in the lateral CST in patients with ALS. Clinical trials registration no. NCT03561623, NCT05764434, NCT06137612 © RSNA, 2024 Supplemental material is available for this article.

Intra-epidermal electrically evoked potentials are sensitive to detect degenerative cervical myelopathy suggesting their spinothalamic propagation

ObjectiveDegenerative cervical myelopathy (DCM) is a centromedullary spinal cord disorder mainly affecting crossing fibers. While contact heat evoked potentials (CHEPs) are sensitive in detecting DCM by testing spinothalamic integrity, somatosensory evoked potentials (dSSEPs) show unaffected dorsal column conduction. Intra-epidermal electrically evoked potentials (IEEPs) have unknown spinal propagation after noxious stimulation. We investigated (1) the spinothalamic tract propagation and (2) the discriminative power in detecting spinal pathology of IEEPs compared to CHEPs and dSSEPs in DCM. MethodsDCM was diagnosed by neurological examination regarding stenosis (MRI). Stimulation of C6, C8, and T4 dermatomes yielded dSSEPs, CHEPs, and IEEPs. (1) Spinal propagation was assessed through concordant or discordant responses, and (2) discriminative power was determined using receiver operating characteristic curves (ROC). ResultsTwenty-seven patients (8F, 56 ± 12yrs) with DCM were analyzed and compared to age-matched healthy controls. IEEPs were abnormal in 43–54%, CHEPs in 37–69%, and dSSEPs in 4–12%. IEEPs showed high concordance with abnormalities of CHEPs (62–69%). ROC analyses showed good discriminative power of CHEPs and IEEPs contrary to dSSEPs. ConclusionsThe concordance of abnormal responses of CHEPs and IEEPs contrary to dSSEPs suggests spinothalamic propagation of IEEPs. SignificanceMinimal differences between CHEPs and IEEPs suggest complementary potential by the combined testing of spinothalamic tract integrity.

Necessity of posterior osteotomies for mild flexible cervical deformity correction.

Correction of mild flexible cervical deformity (CD) via the posterior approach has been described with and without the use of posterior osteotomies (POs), despite a lack of clarity regarding their necessity or risks. The purpose of this study was to determine whether the use of POs when correcting mild flexible CD leads to improved clinical or radiographic outcomes, as well as defining the relative risks in utilizing them. A prospective multicenter registry of operative CD patients was analyzed. Inclusion criteria were cervical kyphosis > 10°, cervical scoliosis > 10°, cervical sagittal vertical axis (cSVA) > 4 cm, or chin-brow vertical angle > 25°. Mild deformity was defined by a cSVA of 3-5 cm and/or kyphosis < 15°. Flexibility was defined by a C2-7 angular change > 5° on preoperative flexion/extension radiographs. Patients who received a posterior column osteotomy (PCO) (Ames grades 1 and 2) were compared with patients who did not undergo a PCO (noPCO) as well as those who underwent a three-column osteotomy (3CO) (Ames grades 3-6). Ninety-five patients (33 PCO, 49 noPCO, 13 3CO) met the inclusion criteria. Both the number of levels fused (9.2 vs 7.7, p = 0.001) and the estimated blood loss (EBL) (1027 vs 486 mL, p = 0.012) were higher in the PCO cohort. Patients in the noPCO group were more likely to have a cervical apex of kyphosis (71.1%, p = 0.046), while those undergoing 3COs were more likely to have a thoracic apex (58.3%, p = 0.005). Preoperative cSVA (PCO vs noPCO: 45.4 vs 37.9 cm, p = 0.084), T1 slope (32.5° vs 29.6°, p = 0.376), C2-7 lordosis (-8.9° vs -9.2°, p = 0.942), and modified Japanese Orthopaedic Association (mJOA) score (13.4 vs 13.5, p = 0.854) were similar; however, both Neck Disability Index (NDI) (55.6 vs 42, p = 0.002) and numeric rating scale (NRS) neck (7.2 vs 5.8, p = 0.028) scores were higher in the PCO group before surgery. When adjusting for the use of an anterior approach, there was no significant difference in 1-year postoperative cSVA (35.7 and 35.6 cm, respectively; p = 0.969), C2-7 lordosis (13.7° and 10.1°, respectively; p = 0.393), and patient-reported outcome measures (NRS, NDI, and mJOA) between the PCO and noPCO groups. Two-year radiographic outcomes were largely similar, except for C2 slope, which was higher in the PCO group (29.1° vs 18°, p = 0.026). The overall complication rates progressively increased with more complex osteotomy use (noPCO 68.8% vs PCO 71.9% vs 3CO 75%) but did not reach significance (p = 0.063). The use of POs for mild flexible adult CD may not be necessary to achieve desirable radiographic correction. They are associated with greater EBL and fusion burden. Further studies are needed to fully delineate the risks of adverse events for various types of osteotomies.

Management of Intraoperative Acetabular Fractures in Total Hip Arthroplasty: A Current Concept Review.

Intraoperative acetabular fractures (IAFs), a complication seldomly encountered in total hip arthroplasty, are typically a result of the impact of insertion of a cementless press-fit cup. Factors that contribute to the risk of these types of fractures include poor bone quality, highly sclerotic bone, and the use of a press-fit cup that is excessively large. The approach to management of these fractures is dependent on when they are identified. Immediate stabilization measures should be implemented for management of fractures detected during surgery. When fractures are detected postoperatively, the decision regarding conservative treatment is dependent on the stability of the implant and the specific fracture pattern. In the majority of cases, effective treatment of an acetabular fracture detected intraoperatively can be administered using a multi-hole revision cup along with anchoring screws in the various regions of the acetabulum. Selection of plate osteosynthesis of the posterior column is recommended when there is a large posterior wall fragment or pelvic discontinuity. In cases where anatomical dimensions allow, cup-cage reconstruction may offer a promising alternative to a combined hip procedure. The number of reports addressing the management of IAFs is limited. This review focuses on outlining the strategies that are currently available for management of this seldomly encountered complication.

Osteotomies At The Time of Graduation Surgery: How Much Do We Get from Them?

Retrospective, Multicenter. Determine if posterior column osteotomies (PCO) at time of conversion from growth friendly instrumentation (GFI) to definitive fusion in early onset scoliosis (EOS) graduates impacts outcomes. Increasing spinal rigidity following treatment of EOS with GFI can limit curve correction at time of conversion to definitive spinal fusion. PCO are often employed at the time of fusion to improve flexibility. This technique's efficacy has not been studied. EOS patients with GFI undergoing conversion to fusion were grouped by those that did or did not have PCO. Patients with inadequate radiographs, <2 years follow-up, or three-column osteotomies at time of fusion were excluded. 832 patients met inclusion criteria. 175 (21%) patients had PCO. Age at index surgery was younger (6.6 vs. 7.4y, P =0.0009) and the mean duration of GFI was greater (6.2 vs. 5.5y, P =0.009) in the PCO group. Prior to fusion, curve magnitude was similar between the groups (PCO=61.9 degrees, no PCO=59.3 degrees, P=0.18). On average 4.4 osteotomies (range: 1 - 12) were performed for the PCO group and EBL (PCO=820cc vs no PCO=752cc, P<0.01) and surgical time (PCO=403min vs no PCO=349min, P<0.01) were greater. Postoperatively, mean curve correction (PCO=16.6, no PCO=14.4 degrees, P=0.18) was similar. Accounting for preoperative curve magnitude, there was a relationship between number of PCOs and curve correction (P=0.04). There was no relationship between degrees of correction per osteotomy and duration of GFI (P=0.12). Postoperative complications at 2 years were similar (PCO=25% vs no PCO=27%, P=0.63). EOS graduates achieve minimal correction at time of conversion regardless of whether PCOs are performed. PCOs increase EBL and operative time but have a similar complication rate. More PCOs resulted in more correction, though less than that anticipated in a previously uninstrumented spine. III.

Ventral posteromedial nucleus of the thalamus gates the spread of trigeminal neuropathic pain

BackgroundWidespread neuropathic pain usually affects a wide range of body areas and inflicts huge suffering on patients. However, little is known about how it happens and effective therapeutic interventions are lacking.MethodsWidespread neuropathic pain was induced by partial infraorbital nerve transection (p-IONX) and evaluated by measuring nociceptive thresholds. In vivo/vitro electrophysiology were used to evaluate neuronal activity. Virus tracing strategies, combined with optogenetics and chemogenetics, were used to clarify the role of remodeling circuit in widespread neuropathic pain.ResultsWe found that in mice receiving p-IONX, along with pain sensitization spreading from the orofacial area to distal body parts, glutamatergic neurons in the ventral posteromedial nucleus of the thalamus (VPMGlu) were hyperactive and more responsive to stimulations applied to the hind paw or tail. Tracing experiments revealed that a remodeling was induced by p-IONX in the afferent circuitry of VPMGlu, notably evidenced by more projections from glutamatergic neurons in the dorsal column nuclei (DCNGlu). Moreover, VPMGlu receiving afferents from the DCN extended projections further to glutamatergic neurons in the posterior insular cortex (pIC). Selective inhibition of the terminals of DCNGlu in the VPM, the soma of VPMGlu or the terminals of VPMGlu in the pIC all alleviated trigeminal and widespread neuropathic pain.ConclusionThese results demonstrate that hyperactive VPMGlu recruit new afferents from the DCN and relay the extra-cephalic input to the pIC after p-IONX, thus hold a key position in trigeminal neuropathic pain and its spreading. This study provides novel insights into the circuit mechanism and preclinical evidence for potential therapeutic targets of widespread neuropathic pain.

Elective Spinal Transpedicular Ablation of the Basivertebral Nerve of the Vertebral Segment in Adult Spinal Deformity Patients.

Ablation of the basivertebral nerve (BVNA) innervating the vertebral endplate has become a standard treatment of vertebrogenic chronic low back pain (CLBP) arising from vertebral endplate damage. BVNA treatment of CLBP in clinical trials was successful and durable for pain relief and return to daily activities. This case review adds new information about older patients with adult degenerative spinal deformity (ASD) and associated comorbidities not previously described in clinical trials. One hundred and eighteen ASD patients with vertebrogenic CLBP in a community practice setting underwent 503 levels of BVNA (average 4.3 levels). Forty-one patients with minimal comorbidities (Group A) were compared to 77 patients with significant comorbidities (Group B). Visual analog scale (VAS 10 cm) and Oswestry Disability Index (ODI 100-point scale) were obtained before BVNA and at a last follow-up (LFU). Group A VAS at LFU was an average of 2 cm, a 7 cm improvement. Group B VAS at LFU was 3 cm, a 6 cm improvement. At LFU, Group A ODI mean was 14 points or minimal disability, with a 39-point improvement, and Group B improved 28 points to 29 but remained moderately disabled. At LFU, the lumbar stenosis with laminectomy and BVNA subgroup of 26 had mean VAS 2 cm and ODI 28-point improvement but remained on average 21 points with a final low moderate disability. Eleven laminectomy and BVNA patients had continued posterior column pain related to radiculopathy, and or peripheral neuropathy, and sacroiliac joint pain in 30%. Mobile spondylolisthesis in 21 patients in Group B at LFU had a 6 cm improvement of VAS and 25-point improvement of ODI but remained moderately disabled on ODI. At LFU in group B, there was a 20% incidence of continued stenosis and radiculopathy symptoms. At LFU, Lumbar fusion was recommended in 9. Vertebral compression fracture (VCF) occurred in 9 after BVNA (10%) of Group B. These patients were older (mean 78 years), and all had significant osteoporosis. Eight fractures were within the area of the BVNA, and 1 was an S2 sacral fracture. These VCF patients were treated with vertebroplasty or kyphoplasty and continued preventive care with added teriparatide. At LFU, the VCF subgroup had a modest 6 cm improvement in VAS to 4 cm and continued to have significant severe to moderate disability (Oswestry Disability Index average of 38 points). Clinical trials of BVNA treatment of CLBP found success and durability for pain relief and daily activities. Patients with ASD without comorbidities showed durable pain relief of vertebrogenic CLBP and return of daily activities similar to clinical trials. In those with comorbidities, the result was an improvement in pain and disability that could be diminished by the complications related to the comorbidities. This is new information about BVNA for older patients with spinal deformity and other comorbidities. This study could impact research practice and policy to expand indications of BVNA to patients with adult spinal deformity. This case series represents the only literature regarding patients with adult spinal deformity treated with BVNA. The results were predictable and reproducible. Many patients were satisfied, would have the procedure again and would recommend BVNA to friends and family. This finding should encourage acceptance of patients with ASD for BVNA and, in fact, BVNA should probably be done before any fusion to limit and choose levels for inclusion in fusion.

Enlarged posterior column osteotomy plus intervertebral cage strutting for lumbosacral nerve bowstring disease

BackgroundTo explore the surgical outcome of enlarged posterior column osteotomy (EPCO) plus intervertebral cage strutting (ICS) for patients with lumbosacral nerve bowstring disease (BSD).MethodsThe clinical data of 27 patients with BSD that surgically treated with EPCO plus ICS from January 2018 to March 2021 were retrospectively reviewed. Patient demographics including age, gender, body mass index (BMI), duration, length of hospital stay, SF-36 were recorded. Surgical data including operation time, blood loss, surgical level, and complications were recorded. Inter-pedicle distance and regional lumbar lordosis was measured at lateral X-ray at both pre- and postoperative.ResultsAll patients underwent the operation successfully. EPCO plus ICS was performed at L4-L5 in 9 patients, at L5-S1 in 7 patients, at L4-S1 in 6 patients, at L3-L5 in 5 patients. The mean operation time was 96.3 ± 18.0 min, mean blood loss was 350.0 ± 97.9 mL. Relaxation of thecal sac was noticed after pedicle screw-rod compression bilaterally. The mean decrease of inter-pedicle distance was 0.57 ± 0.18 cm, the mean increase of regional lumbar lordosis was 17.6 ± 6.7 degrees. Relaxation of cauda equina within the thecal sac was noticed at intra-operative after pedicle screw-rod compression bilaterally in all the patients. Most patients achieved neurological function improvement at two-year follow up.ConclusionsEPCO plus ICS procedure is an effective surgical method for lumbosacral nerve BSD through restoring the coordination between column and cord, visual relaxation of cauda equina within the thecal sac at intraoperative is the key factor in determining the relief of neurological function at postoperative.

A novel technique for posterior lumbar interbody fusion to obtain a good local lordosis angle: anterior-release posterior lumbar interbody fusion.

Herein, we describe a novel posterior lumbar interbody fusion (PLIF) technique with annulus fibrosus (AF) release and the use of expandable cages (called "anterior-release PLIF" [ARPLIF]). In this technique, posterior column osteotomy (PCO) and AF release provide excellent intervertebral mobility. AF release involves circumferentially peeling off the AF above or below the endplate between the fixed vertebrae under radiographic guidance without cutting the AF and anterior longitudinal ligament. Subsequently, high-angle variable-angle expandable cages are used to simultaneously expand both sides before inserting the percutaneous pedicle screws and correcting to achieve good local lumbar lordosis. PCO and AF release achieve excellent intervertebral mobility. Intervertebral mobility and simultaneous expansion of both cages disperse the force on the endplates, reducing cage subsidence, and the high-angle cages facilitate high intervertebral angle creation. The novel ARPLIF intervertebral manipulation technique can promote good local lumbar lordosis formation.

Multiple guidance mechanisms control axon growth to generate precise T-shaped bifurcation during dorsal funiculus development in the spinal cord.

The dorsal funiculus in the spinal cord relays somatosensory information to the brain. It is made of T-shaped bifurcation of dorsal root ganglion (DRG) sensory axons. Our previous study has shown that Slit signaling is required for proper guidance during bifurcation, but loss of Slit does not affect all DRG axons. Here, we examined the role of the extracellular molecule Netrin-1 (Ntn1). Using wholemount staining with tissue clearing, we showed that mice lacking Ntn1 had axons escaping from the dorsal funiculus at the time of bifurcation. Genetic labeling confirmed that these misprojecting axons come from DRG neurons. Single axon analysis showed that loss of Ntn1 did not affect bifurcation but rather altered turning angles. To distinguish their guidance functions, we examined mice with triple deletion of Ntn1, Slit1, and Slit2 and found a completely disorganized dorsal funiculus. Comparing mice with different genotypes using immunolabeling and single axon tracing revealed additive guidance errors, demonstrating the independent roles of Ntn1 and Slit. Moreover, the same defects were observed in embryos lacking their cognate receptors. These in vivo studies thus demonstrate the presence of multi-factorial guidance mechanisms that ensure proper formation of a common branched axonal structure during spinal cord development.

30. Posterior column osteotomies and not lumbar decompressions alone improve lower extremity motor strength in adult spinal deformity patients with preoperative motor impairment

30. Posterior column osteotomies and not lumbar decompressions alone improve lower extremity motor strength in adult spinal deformity patients with preoperative motor impairment

Combining Innovative Techniques: Total Extraperitoneal Approach in Orthopedic Surgery (O-TEP) and Percutaneous Both Column Screw (BCS) Fixation Technique in a Geriatric Acetabular Fracture Case.

The concepts of both column fixation corridor (BCFC) and both column screws (BCS) along with the orthopedic total extraperitoneal approach (O-TEP) are highly innovative approaches in orthopedic surgery. However, the orthopedic literature lacks sufficient studies on these topics, indicating a significant gap. This case report aims to highlight how combining these innovative techniques can facilitate the use of BCFC and BCS in the treatment of acetabular fractures with O-TEP, thereby enhancing the feasibility of endoscopic techniques. Furthermore, we aim to discuss the potential advantages of BCFC and BCS concepts when used in O-TEP.For this purpose, we present a case of a 74-year-old geriatric patient with a transverse acetabular fracture involving the posterior column. The quadrilateral surface was exposed using the O-TEP approach, and the fracture was reduced using a fully endoscopic approach. The fixation was achieved using BCS and a Magic screw through percutaneous screw placement.The patient's clinical condition was followed for at least 13 months. The clinical outcomes demonstrated the effectiveness of combining these innovative techniques in the treatment of acetabular fractures, with satisfactory healing and functional recovery observed.This case report illustrates that combining BCFC and BCS with the O-TEP approach can facilitate the treatment of acetabular fractures with minimally invasive techniques and enhance the feasibility of endoscopic procedures. These findings suggest potential advantages of using BCFC and BCS concepts in O-TEP, warranting further investigation and study.

High incidence of femoroacetabular impingement deformity in bi-column acetabular fractures.

Dynamic interaction of cam and pincer deformities can result in pathological contact forces in femoroacetabular impingement (FAI) syndrome. Similar deformities were noted during acetabular fracture reconstruction. We hypothesise that the prevalence of FAI deformity is higher in patients sustaining acetabular fractures than in a control group. This retrospective radiographic study compared the parameters that define FAI deformity in 100 patients consecutively admitted to a trauma unit with an acetabular fracture and a control group of 100 patients with lateral compression pelvic fracture without acetabular injury. Both underwent identical clinical imaging. Centre-edge angles (CEA) and alpha angles were used to define patients with pincer, cam, or mixed FAI deformity. There were significantly more patients with FAI deformity in the acetabular fracture group than in the control group (71% vs. 18%, p < 0.0001). There were considerably more fractures involving both anterior and posterior acetabular columns in patients with 'pincer' sockets (p = 0.02, OR = 2.95, 95% CI, 1.12-7.78). There is a high prevalence of cam and pincer deformities in patients with acetabular fractures, particularly bi-column fractures.

Atlas-guided brain projection tracts: From regions of interest to tractography 3D rendering.

The use of diffusion tensor imaging (DTI) has seen significant development over the last two decades, in particular with the development of the tractography of association tracts for preoperative planning of surgery. However, projection tracts are difficult to differentiate from one another and tractography studies have failed to reconstruct these ascending/descending pathways from/to the spinal cord. The present study proposes an atlas of regions of interest (ROIs) designed specifically for projection tracts tractography. Forty-nine healthy subjects were included in this prospective study. Brain DTI was acquired using the same 3 T MRI scanner, with 32 diffusion directions. Distortions were corrected using the FSL software package. ROIs were drawn using the anterior commissure (AC)-posterior commissure (PC) line on the following landmarks: the pyramid for the corticospinal tract, the medio-caudal part of the red nucleus for the rubrospinal tract, the pontine reticular nucleus for corticoreticular tract, the superior and inferior cerebellar peduncles for, respectively, the anterior and posterior spinocerebellar tract, the gracilis and cuneatus nucleus for the dorsal columns, and the ventro-posterolateral nucleus for the spinothalamic tract. Fiber tracking was performed using a deterministic algorithm using DSI Studio software. ROI coordinates, according to AC-PC line, were given for each tract. Tractography was obtained for each tract, allowing tridimensional rendering and comparison of tracking metrics between tracts. The present study reports the accurate design of specific ROIs for tractography of each projection tract. This could be a useful tool in order to differentiate projection tracts at the spinal cord level.