Spinal Neurenteric Cyst of the Ventral Cervicothoracic Junction With Klippel-Feil Syndrome as a Symptom of Progressive Myelopathy: A Case Report

Neurenteric cysts are rare and account for only 0.7%-1.3% of all spinal tumors. Spinal neurenteric cysts are associated with spina bifida, split-cord malformations, and Klippel-Feil syndrome, a rare congenital disorder characterized by fusion of two or more cervical vertebrae. Klippel-Feil syndrome is rarely accompanied by neurenteric cysts. In this case report, we describe a cervicothoracic junction neurenteric cyst associated with Klippel-Feil syndrome in a 30-year-old man who presented with a 2-month history of neck pain with radiation of pain into both arms and a 1-month history of weakness in the left arm. Magnetic resonance imaging (MRI) of the spine revealed an expansive intradural extramedullary cystic lesion anterior to the spinal cord at the cervicothoracic junction. The neurenteric cyst was removed using an anterior approach, accompanied by C5-C6 corpectomy. The patient's condition improved postoperatively, and he was discharged after postoperative MRI. Spinal neurenteric cysts should be considered in the differential diagnosis in cases of vertebral developmental abnormalities concurrent with intraspinal cysts.

Bone Substitute Options for Spine Fusion in Patients With Spine Trauma-Part II: The Role of rhBMP

In Part II, we focus on an important aspect of spine fusion in patients with spine trauma: the pivotal role of recombinant human bone morphogenetic protein-2 (rhBMP-2). Despite the influx of diverse techniques facilitated by technological advancements in spinal surgery, spinal fusion surgery remains widely used globally. The persistent challenge of spinal pseudarthrosis has driven extensive efforts to achieve clinically favorable fusion outcomes, with particular emphasis on the evolution of bone graft substitutes. Part II of this review aims to build upon the foundation laid out in Part I by providing a comprehensive summary of commonly utilized bone graft substitutes for spinal fusion in patients with spinal trauma. Additionally, it will delve into the latest advancements and insights regarding the application of rhBMP-2, offering an updated perspective on its role in enhancing the success of spinal fusion procedures.

Effect of Furosemide on Prevertebral Soft Tissue Swelling after Anterior Cervical Fusion: A Comparative Study with Dexamethasone

STUDY DESIGN

Retrospective cohort study.

PURPOSE

This study aimed to investigate the effect of furosemide on prevertebral soft tissue swelling (PSTS) after anterior cervical fusion (ACF) and compare it with the effect of dexamethasone.

OVERVIEW OF LITERATURE

Postoperative PSTS is a common complication of ACF. Dexamethasone has been used for its treatment; however, its efficacy remains controversial. Furosemide may reduce PSTS if it is soft tissue edema; however, no studies have demonstrated the effect of furosemide on PSTS after ACF.

METHODS

The symptomatic PSTS group received intravenous (IV) administration of dexamethasone or furosemide. The asymptomatic PSTS group did not receive any medication. Patients were divided into the control (no medication, n=31), Dexa (IV dexamethasone, n=25), and Furo (IV furosemide, n=28) groups. PSTS was checked daily with simple radiographs and medication-induced reductions in PSTS from its peak or after medication.

RESULTS

The peak time (postoperative days) of PSTS in the control (2.27±0.47, p<0.05) and Dexa (1.91±0.54, p<0.01) groups were significantly later than that in the Furo group (1.38±0.74). PSTS was significantly lower in the Furo group than in the Dexa group from postoperative days 4 to 7 (p<0.05). PSTS reduction after the peak was significantly greater in the Furo group than in the control (p<0.01) and Dexa (p<0.01) groups. After starting the medication therapy, the Furo group showed a significantly greater reduction in PSTS than the Dexa group (p<0.01). No difference was found in symptom improvement among the three groups.

CONCLUSIONS

If furosemide is used to reduce PSTS after ACF, it can effectively reduce symptoms.

Clinical impact of craniectomy on shunt-dependent hydrocephalus after intracerebral hemorrhage: A propensity score-matched analysis

PURPOSE

A consensus on decompressive craniectomy for intracerebral hemorrhage (ICH) has not yet been established. We aimed to investigate the development of shunt-dependent hydrocephalus based on the method of ICH surgery, with a focus on craniectomy.

METHODS

We retrospectively enrolled 458 patients with supratentorial ICH who underwent surgical hematoma evacuation between April 2005 and December 2021 at two independent stroke centers. Multivariate analyses were performed to characterize risk factors for postoperative shunt-dependent hydrocephalus. Propensity score matching (1:2) was undertaken to compensate for group-wise imbalances based on probable factors that were suspected to affect the development of hydrocephalus, and the clinical impact of craniectomy on shunt-dependent hydrocephalus was evaluated by the matched analysis.

RESULTS

Overall, 43 of the 458 participants (9.4%) underwent shunt procedures as part of the management of hydrocephalus after ICH. Multivariate analysis revealed that intraventricular hemorrhage (IVH) and craniectomy were associated with shunt-dependent hydrocephalus after surgery for ICH. After propensity score matching, there were no statistically significant intergroup differences in participant age, sex, hypertension status, diabetes mellitus status, lesion location, ICH volume, IVH occurrence, or IVH severity. The craniectomy group had a significantly higher incidence of shunt-dependent hydrocephalus than the non-craniectomy group (28.9% vs. 4.3%, p < 0.001; OR 9.1, 95% CI 3.7-22.7), craniotomy group (23.2% vs. 4.3%, p < 0.001; OR 6.6, 95% CI 2.5-17.1), and catheterization group (20.0% vs. 4.0%, p = 0.012; OR 6.0, 95% CI 1.7-21.3).

CONCLUSION

Decompressive craniectomy seems to increase shunt-dependent hydrocephalus among patients undergoing surgical ICH evacuation. The decision to perform a craniectomy for patients with ICH should be carefully individualized while considering the risk of hydrocephalus.

Bone Substitute Options for Spine Fusion in Patients With Spine Trauma-Part I: Fusion Biology, Autografts, Allografts, Demineralized Bone Matrix, and Ceramics

Spinal trauma accounts for a large portion of injuries to the spine area, particularly as societies are entering an era of aging populations. Consequently, spine fractures accompanied by osteoporosis are becoming more prevalent. Achieving successful fusion surgery in patients with spine fractures associated with osteoporosis is even more challenging. Pseudarthrosis in the spine does not yield clinically favorable results; however, considerable effort has been made to achieve successful fusion, and the advancement of bone graft substitutes has been particularly crucial in this regard. Autograft bone is considered the best fusion material but is limited in use due to the quantity that can be harvested during surgery and associated complications. Accordingly, various bone graft substitutes are currently being used, although no specific guidelines are available and this mainly depends on the surgeon's choice. Therefore, the purpose of this review, across part I/II, is to summarize bone graft substitutes commonly used in spine surgery for spine fusion in patients with spine trauma and to update the latest knowledge on the role of recombinant human bone morphogenetic protein-2.

Effect of Mixture of Recombinant Human Bone Morphogenic Protein-2 and demineralized Bone Matrix in Lateral Lumbar Interbody Fusion

Objective

This study aims to determine the optimal dose of recombinant-human Bone Morphogenic Protein-2 (rhBMP-2) for successful bone fusion in minimally invasive Lateral Lumbar Interbody Fusion (MIS LLIF). Previous studies show that rh-BMP is an effective alternative to autologous iliac crest bone graft, but the optimal dose remains uncertain. The study analyzes the fusion rates associated with different rh-BMP doses to provide a recommendation for the optimal dose in MIS LLIF.

Methods

93 patients underwent MIS LLIF using demineralized bone matrix (DBM) or a mixture of rhBMP-2 and DBM as fusion material. The group was divided into the following three groups according to the rhBMP-2 usage. Group A (only DBM was used, n: 27). Group B (1mg of rhBMP-2 per 5cc of DBM paste, n: 41). Group C (2mg of rhBMP-2 per 5cc of DBM paste, n: 25). Demographic data, clinical outcomes, postoperative complication and fusion were assessed.

Results

At 12 months post-surgery, the overall fusion rate was 92.3% according to Bridwell fusion grading system. Group B and C, who received rhBMP-2, had significantly higher fusion rates than group A, who received only DBM. However, there was no significant increase in fusion rate when the rhBMP-2 dosage was increased from group B to group C. The group B and C showed significant improvement in back pain and ODI compared to the group A. The incidence of screw loosening was decreased in group B and C, but there was no significant difference in the occurrence of other complications.

Conclusion

Usage of rhBMP-2 in LLIF surgery leads to early and increased final fusion rates, which can result in faster pain relief and return to daily activities for patients. The benefits of using rhBMP-2 were not significantly different between the groups that received 1mg/5cc and 2mg/5cc of rhBMP-2. Therefore, it is recommended to use 1mg of rhBMP-2 with 5cc of DBM, taking both economic and clinical aspects into consideration.

Kummell's Disease is Becoming Increasingly Important in an Aging Society: A Review

Kummell's disease (KD) is referred to as delayed posttraumatic vertebral collapse, avascular necrosis of vertebrae, or ischemic vertebral collapse. KD is no longer rare in an aging society. It is mainly caused by minor trauma, and nonunion occurs secondary to avascular necrosis at the vertebral body fracture site, which can lead to vertebral kyphosis or intravertebral instability. Clinical symptoms of KD range from no symptoms to severe paralysis due to nerve injury. KD is considered a complication of osteoporotic vertebral compression fractures, and conservative treatment, including osteoporosis treatment, is important. Timely interventions such as vertebral augmentation or surgery, with active regular follow-up are necessary before the onset of neurological deficits due to osteonecrotic collapse in patients with suspected KD. In this study, we summarize the pathogenesis, diagnosis, and treatment of KD, which is showing increasing prevalence in an aging society. We have presented a literature review and discussed clinical guidelines and therapeutic strategies to reduce the morbidity and mortality associated with KD.

Occlusion of Both Vertebral Arteries With Development of Collateral Circulation From the Deep Cervical Artery After Cervical Spine Trauma

Careful evaluation of vertebral artery injuries is important after cervical translation injuries or transverse foramen fractures. Treatment of trauma can be complicated in cases of concomitant vertebral artery injuries. A 76-year-old woman was admitted to our hospital with left hemiparesis (Motor grade 3) after a motorcycle accident. Cervical spine magnetic resonance imaging (MRI) and computed tomography (CT) revealed a C3 burst fracture and a left C3 lateral mass and lamina fracture. CT angiography revealed fracture fragments that predisposed the vertebral artery to injury throughout its course in the area. CT angiography confirmed that both vertebral arteries were occluded at the C3 fracture site. Subsequent brain MRI revealed acute infarction in the right occipital area. Although both vertebral arteries were occluded, the infarction site did not correspond to the territory supplied by these vessels; therefore, we performed transfemoral cerebral angiography, which revealed collateralization of the bilateral vertebral arteries by the deep cervical artery.. The deep cervical arteries are located between the posterior muscles; therefore, a fixation operation performed using the posterior approach may have affected the collateral circulation and led to exacerbation of the infarction site. Therefore, surgery was performed using an anterior approach and it was possible to minimize the risk of cerebral infarction through preservation of collateral circulation.

An Anatomical Clue for Minimizing Iliac Vein Injury During the Anterolateral Approach at L5-S1 Level: A Cadaveric Study

Objective

The injury to the common iliac vein (CIV) seems to be the most important concern during the anterior approach to the spine at L5–S1 level. We investigated the anatomy of the L5–S1 vertebral structures related to the CIV through a cadaveric study to find an anatomical clue for safe dissection of CIV.

Methods

Ten cadavers were prepared for this study. After removing the peritoneum and the presacral fascia, the section from the lower part of the L5 to the upper part of the S1 vertebral body was removed with the CIV attached. After decalcification, 2 sections in the vertical and horizontal directions were made for histological study.

Results

An adipose tissue layer was present between the intervertebral disc and CIV. The adipose tissue layer in 6 cadavers was thin, and in 3 of these cadavers, the CIV was attached to the vertebral body and the disc. In the other 4 cadavers, the CIV was clearly separated from the vertebral body and the disc by the intervening adipose tissue layer (IATL). Under the microscope, a thin layer surrounding the anterior longitudinal ligament, periosteum, and disc was observed, and we named this structure the ‘perivertebral membrane.’ The perivertebral membrane was attached to the CIV when there was no IATL, but a potential space was detected under the membrane.

Conclusion

There was a thin membrane, perivertebral membrane, between the CIV and L5–S1 disc. In cases with CIV adhesion to the disc due to the absence of IATL, the CIV may be mobilized indirectly through the perivertebral membrane.

Importance of Surgical Order for Minimizing Vascular Injury During the L5-S1 Approach in Multilevel Oblique Lateral Interbody Fusion Surgery

Objective

In oblique lateral interbody fusion (OLIF) surgery at the L5-S1 level (OLIF51), anatomical complexity and the possibility of vascular injury during retraction of the common iliac vein (CIV) make the surgery challenging. We radiologically evaluated patients who underwent OLIF surgery to determine approaches that can make OLIF51 surgery easier during multilevel OLIF.

Methods

We retrospectively analyzed 275 consecutive patients who underwent OLIF surgery between September 2014 and December 2019. The distance between the left and right CIVs (dCIV) was measured using an axial image at the L5 lower endplate level, and the height of the iliocaval junction (hCIV) was measured from the L5 lower endplate to the iliocaval junction in the sagittal image. The sum of anterior disc height of each level (sADH) was calculated.

Results

Eighty-two patients (33 males and 49 females) were enrolled. The number of three- (L2-3-4-5), two- (L3-4-5), and one-level (L4-5) fusions was 13, 21, and 48, respectively. Changes between the pre- and postoperative sADH, dCIV, and hCIV values were 17.1±4.7, 7.7±3.5, and 13.1±4.7 mm in three-level fusion; 10.6±4.1, 5.6±3.7, and 7.0±3.1 in two-level fusion; and 4.3±2.5, 3.3±2.7, and 3.0±2.0 mm in one-level fusion, respectively. As the number of surgical levels increased, the changes in sADH, dCIV, and hCIV significantly increased.

Conclusions

The dCIV and hCIV values increased when the upper segment underwent surgery before OLIF51 during multilevel OLIF.

Relationship between Increased Intracranial Pressure and Mastoid Effusion

Objective

This study aimed to assess the relationship between increased intracranial pressure (ICP) and mastoid effusions (ME).

Methods

Between January 2015 and October 2018, patients who underwent intracranial surgery and had ICP monitoring catheters placed were enrolled. ICP was recorded hourly for at least 3 days. ME was determined by the emergence of opacification in mastoid air cells on follow-up brain imaging. C-reactive protein (CRP) levels, presence of endotracheal tube (ETT) and nasogastric tube (NGT), duration of intensive care unit (ICU) stay, duration of mechanical ventilator application, diagnosis, surgical modalities, and presence of sinusitis were recorded. Each factor’s effect on the occurrence of ME was analyzed by binary logistic regression analyses. To analyze the independent effects of ICP as a predictor of ME a multivariable logistic regression analysis was performed.

Results

Total of 61 (53%) out of 115 patients had ME. Among the patients who had unilateral brain lesions, 94% of subject (43/50) revealed the ipsilateral development of ME. ME developed at a mean of 11.1±6.2 days. The variables including mean ICP, peak ICP, age, trauma, CRP, ICU stays, application of mechanical ventilators and presence of ETT and NGT showed statistically significant difference between ME groups and non-ME groups in univariate analysis. Sex and the occurrence of sinusitis did not differ between two groups. Adding the ICP variables significantly improved the prediction of ME in multivariable logistic regression analysis.

Conclusion

While multiple factors affect ME, this study demonstrates that ICP and ME are probably related. Further studies are needed to determine the mechanistic relationship between ICP and middle ear pressure.

Preservation of Deep Cervical Extensor Muscle Volume: Comparison Between Conventional Open-Door and Muscle Preserving Laminoplasty Approaches in the Same Patients

BACKGROUND

Surgical laminoplasty techniques have been developed to reduce cervical kyphosis and postoperative axial neck pain and preserve the posterior cervical extensor muscles. We compared a unilateral conventional open approach (OA) and a contralateral muscle preserving approach (MPA) for laminoplasty in the same patients to determine differences in the preservation of the posterior cervical muscles after the 2 approaches.

METHODS

This study was a prospective observational study involving 44 patients who underwent laminoplasty with unilateral OA and contralateral MPA for cervical myelopathy from January 2005 to December 2013. The cross-sectional area (CSA) changes in the posterior cervical extensor muscles (multifidus, semispinalis cervicis, and semispinalis capitis muscles) were measured on computed tomography scan, both pre- and postoperatively.

RESULTS

Using an OA, the multifidus and semispinalis cervicis muscle preservation was 58.2% and 67.0%, but using an MPA, muscle preservation was 97% and 90.8% (P < 0.001 and P = 0.042), respectively. However, the CSA of the semispinalis capitis muscle did not differ significantly between the 2 groups. In terms of the level, conservation of the multifidus muscle was significantly different according to the approach at all levels, and the conservation of the deep extensor muscles was significantly different at the C3-4 level.

CONCLUSIONS

MPA was effective in preserving the volume of deep cervical extensor muscles and helping minimize postoperative musculoskeletal complications. In addition, muscle preservation was more effective at the C3-4 level.

An Intramuscular Epidermal Cyst of Erector Spinae Muscles: A Case Report

An intramuscular epidermal cyst without subcutaneous involvement is extremely rare. The patient presented with low back pain. Spinal magnetic resonance imaging indicated spindle-shaped mass in the right erector spinae muscles located at L3 to L5 level without any connection with subcutaneous tissue. The patient underwent operation for removal of intramuscular cystic lesion. The tumor was totally removed and pathologically confirmed with epidermal cyst. Unlike typical epidermal cyst, the patient had a characteristic clinical manifestation of mild low back pain without palpable mass and local tenderness.

Correction of marked sagittal deformity with circumferential minimally invasive surgery using oblique lateral interbody fusion in adult spinal deformity

BACKGROUND

Spinal surgery performed entirely with minimally invasive surgery is referred to as circumferential MIS (cMIS). However, cMIS still has a limited sagittal correction capability for adult spinal deformity (ASD) with a marked sagittal deformity. We investigated the effectiveness of cMIS using oblique lateral interbody fusion (OLIF) and percutaneous posterior spine fixation in correcting marked sagittal deformity.

METHODS

This study retrospectively evaluated 23 patients with ASD with marked sagittal deformity who underwent cMIS using OLIF without osteotomy and were followed-up for at least 24 months (whole group). The whole group was divided into the following two groups according to the type of interbody fusion at L5-S1: the OLIF51 group (n = 13) underwent OLIF at L1-L5 and L5-S1 and the TLIF51 group (n = 10) underwent OLIF at L1-L5 and transforaminal lumbar interbody fusion (TLIF) at L5-S1.

RESULTS

Sagittal vertebral axis (SVA; 125.7 vs. 29.5 mm, p < 0.001), lumbar lordosis (LL; 18.2° vs. 51.7°, p < 0.001), and pelvic incidence-LL mismatch (PI-LL, 35.5° vs. 5.3°) significantly improved postoperatively in the whole group. The OLIF51 group showed significantly higher postoperative LL than the TLIF51 group (55.5° vs. 46.9°, p < 0.001). OLIF yielded a significantly greater disc angle at L5-S1 than did TLIF (18.4° vs. 6.9°, p < 0.001). Proximal junctional kyphosis occurred significantly earlier in the OLIF51 group than in the TLIF51 group (8.6 vs. 26.3 months, p < 0.001).

CONCLUSION

Successful sagittal correction in ASD patients with marked sagittal deformity was achieved with cMIS using OLIF. OLIF at L5-S1 showed a synergistic effect in sagittal deformity correction by cMIS.

Locating the Instant Center of Rotation in the Subaxial Cervical Spine with Biplanar Fluoroscopy during In Vivo Dynamic Flexion-Extension

Background

Recently, biplanar fluoroscopy is used to evaluate the cervical kinematics, especially to locate the instant center of rotation (ICR) during in vivo motion. This study aims to ascertain the ICR at each cervical segment in the sagittal plane during dynamic motion and assess the differences from previous studies.

Methods

While three healthy subjects were performing full flexion-extension, two oblique views aligned horizontally and angled at approximately 55° were obtained by biplanar fluoroscopy. The minimum degree to detect significant movement in a helical axis model was set at 2°, and anterior-posterior and superior-inferior locations of each ICR were defined. To evaluate the possible distribution area and overlapping area of the ICR with disc space, we drew a circle by using the calculated distance between each coordination and the mean coordination of ICR as the radius.

Results

During flexion-extension motion, the mean superior-inferior location of the ICR became progressively more superior, except the C5–6 segment (p = 0.015), and the mean anterior-posterior location of the ICR became progressively more anterior without exception from C2–3 to C6–7 segments, but anterior-posterior ICR locations were not significantly different among segments. The overlapping area with the distribution circle of ICR was mainly located in the posterior half in the C3–4 segment, but the overlapping area was about 80% of the total disc space in C4–5 and C6–7 segments. The overlapping was more noticeable in the lower cervical segments after exclusion of the outlier data of the C5–6 segment in subject 1.

Conclusions

The ICR in the cervical spine showed a trend of moving progressively more superiorly and anteriorly and the disc space overlapping the distribution circle of ICR increased along the lower motion segments except the C5–6 segment. These findings could provide a good basis for level-specific cervical arthroplasty designs.

A New Shielding Curtain for Protection of Intraoperative Radiation During Minimally Invasive Spine Surgery

Objective

Gradually increasing number of minimally invasive spine surgery (MISS), there is an increasing risk of radiation exposure to medical personnel during the surgery. We measured the radiation exposure of the operating room personnel during MISS, tried to find the riskiest person, and checked the effectiveness of a new lead-composite shielding curtain.

Methods

Radiation exposure of medical staffs (operator, first assistant, anesthesiologist, and scrub nurse) involved in MISS procedures of 35 patients without shielding curtain (nonshield group) and 35 patients with shielding curtain (shield group). The shielding curtain had 0.25-mm nominal lead equivalent and was mounted on 2 frame bars fixed on the operating table.

Results

In the nonshield group, radiation exposure was significantly higher in the order of operator > first assistant > scrub nurse > anesthesiologist (p < 0.001) during both anteroposterior (AP) and lateral views. In the shield group, the radiation exposure of the operator and the scrub nurse decreased significantly by 94.1% and 76.4% in AP view (p < 0.001), and by 96.3% and 73.9% in lateral view (p < 0.001), respectively.

Conclusion

Since the radiation dose of the operator was highest in a C-arm-guided MISS, there is a high priority need to protect the operator from the radiation exposure. The shielding curtain could most effectively reduce the radiation exposure of the operator.

Usefulness of Oblique Lateral Interbody Fusion at L5-S1 Level Compared to Transforaminal Lumbar Interbody Fusion

Objective

The use of oblique lateral interbody fusion at the L5–S1 level (OLIF51) is increasing, but no study has directly compared OLIF51 and transforaminal lumbar interbody fusion (TLIF) at the L5–S1 level. We evaluated the usefulness of OLIF51 by comparing clinical and radiologic outcomes with those of TLIF at the same L5–S1 level.

Methods

We retrospectively reviewed and compared 74 patients who underwent OLIF51 (OLIF51 group) and 74 who underwent TLIF at the L5–S1 level (TLIF51 group). Clinical outcomes were assessed with the visual analogue scale for back pain and leg pain and the Oswestry Disability Index. Mean disc height (MDH), foraminal height (FH), disc angle (DA), fusion rate, and subsidence rate were measured for radiologic outcomes.

Results

The OLIF51 group used significantly higher, wider, and larger-angled cages than the TLIF51 group (p<0.001). The postoperative MDH and FH were significantly greater in the OLIF51 group than in the TLIF51 group (p<0.001). The postoperative DA was significantly larger in the OLIF51 group than in the TLIF51 group by more than 10º (p<0.001). The fusion rate was 81.1% and 87.8% at postoperative 6 months in the OLIF51 and TLIF51 groups, respectively, and the TLIF51 group showed a higher fusion rate (p<0.05). The subsidence rate was 16.2% and 25.3% in the OLIF51 and TLIF51 groups, respectively, and the OLIF51 group showed a lower subsidence rate (p<0.05).

Conclusion

OLIF51 was more effective for the indirect decompression of foraminal stenosis, providing strong mechanical support with a larger cage, and making a greater lordotic angle with a high-angle cage than with TLIF.

Effect of Cage in Radiological Differences between Direct and Oblique Lateral Interbody Fusion Techniques

Objective

Few studies have reported direct comparative data of lumbar spine angles between direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF). The purpose of this study was to investigate the clinical and radiological outcomes of DLIF and OLIF, and determine influential factors.

Methods

The same surgeon performed DLIF from May 2011 to August 2014 (n=201) and OLIF from September 2014 to September 2016 (n=142). Radiological parameters, cage height, cage angle (CA), cage width (CW), and cage location were assessed. We checked the cage location as the distance (mm) from the anterior margin of the disc space to the anterior metallic indicator of the cage in lateral images.

Results

There were significant differences in intervertebral foramen height (FH; 22.0±2.4 vs. 21.0±2.1 mm, p<0.001) and sagittal disc angle (SDA; 8.7±3.3 vs. 11.3±3.2˚, p<0.001) between the DLIF and OLIF groups at 7 days postoperatively. CA (9.6±3.0 vs. 8.1±2.9˚, p<0.001) and CW (21.2±1.6 vs. 19.2±1.9 mm, p<0.001) were significantly larger in the OLIF group compared to the DLIF group. The cage location of the OLIF group was significantly more anterior than the DLIF group (6.7±3.0 vs. 9.1±3.6 mm, p<0.001). Cage subsidence at 1 year postoperatively was significantly worse in the DLIF group compared to the OLIF group (1.0±1.5 vs. 0.4±1.1 mm, p=0.001). Cage location was significantly correlated with postoperative FH (β=0.273, p<0.001) and postoperative SDA (β=-0.358, p<0.001). CA was significantly correlated with postoperative FH (β=-0.139, p=0.044) and postoperative SDA (β=0.236, p=0.001). Cage location (β=0.293, p<0.001) and CW (β=-0.225, p<0.001) were significantly correlated with cage subsidence.

Conclusion

The cage location, CA, and CW seem to be important factors which result in the different-radiological outcomes between DLIF and OLIF.

Correction of Spondylolisthesis by Lateral Lumbar Interbody Fusion Compared with Transforaminal Lumbar Interbody Fusion at L4-5

Objective

In an aging society, the number of patients with symptomatic degenerative spondylolisthesis (DS) is increasing and there is an emerging need for fusion surgery. However, few studies have compared transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) for the treatment of patients with DS. The purpose of this study was to investigate the clinical and radiological outcomes between TLIF and LLIF in DS.

Methods

We enrolled patients with symptomatic DS at L4–5 who underwent TLIF with open pedicle screw fixation (TLIF group, n=41) or minimally invasive LLIF with percutaneous pedicle screw fixation (LLIF group, n=39) and were followed-up for more than one year. Clinical (visual analog scale and Oswestry disability index) and radiological outcomes (spondylolisthesis rate, segmental sagittal angle [SSA], mean disc height [MDH], intervertebral foramen height [FH], cage subsidence, and fusion rate) were assessed. And we assessed the changes in radiological parameters between the postoperative and the last follow-up periods.

Results

Preoperative radiological parameters were not significantly different between the two groups. LLIF was significantly superior to TLIF in immediate postoperative radiological results, including reduction of spondylolisthesis rate (3.8% and 7.2%), increase in MDH (13.9 mm and 10.3 mm) and FH (21.9 mm and 19.4 mm), and correction of SSA (18.9° and 15.6°) (p<0.01), and the changes were more stable from the postoperative period to the last follow-up (p<0.01). Cage subsidence was observed significantly less in LLIF (n=6) than TLIF (n=21). Fusion rate was not different between the two groups. The clinical outcomes did not differ significantly at any time point between the two groups. Complications were not statistically significant. However, TLIF showed chronic mechanical problems with screw loosening in four patients and LLIF showed temporary symptoms associated with the surgical approach, such as psoas and ileus muscle symptoms in three and two cases, respectively.

Conclusion

LLIF was more effective than TLIF for spondylolisthesis reduction, likely due to the higher profile cage and ligamentotactic effect. In addition, LLIF showed mechanical stability of the reduction level by using a cage with a larger footprint. Therefore, LLIF should be considered a surgical option before TLIF for patients with unstable DS.

The Effect of Postoperative Use of Teriparatide Reducing Screw Loosening in Osteoporotic Patients

Objective

The loosening of pedicle screws (PS) is one of the frequent problems of spinal surgery in the patients with osteoporosis. Previous studies had revealed that intermittent injection of teriparatide could reduce PS loosening by improving bone mass and quality when their patients took parathyroid hormone for a considerable duration before surgery. However, although the teriparatide is usually used after spine surgery in most clinical situations, there was no report on the efficacy of teriparatide treatment started after spine surgery. The purpose of this retrospective study was to examine the efficacy of teriparatide treatment started immediately after lumbar spinal surgery to prevent pedicle screw loosening in patients with osteoporosis.

Methods

We included 84 patients with osteoporosis and degenerative lumbar disease who underwent transforaminal interbody fusion and PS fixation and received parathyroid hormone or bisphosphonate (BP) postoperatively. They were divided into teriparatide group (daily injection of 20 μg of teriparatide for 6 months, 33 patients, 172 screws) and BP group (weekly oral administration of 35 mg of risedronate, 51 patients, 262 screws). Both groups received calcium (500 mg/day) and cholecalciferol (1000 IU/day) together. The screw loosening was evaluated with simple radiographic exams at 6 and 12 months after the surgery. We counted the number of patients with PS loosening and the number of loosened PS, and compared them between the two groups. Clinical outcomes were evaluated using visual analog scale (VAS) and Oswestry disability index (ODI) preoperatively, and at 12 months after surgery.

Results

There was no significant difference in the age, sex, diabetes, smoking, bone mineral density, body mass index, and the number of fusion levels between the two groups. The number of PS loosening within 6 months after surgery did not show a significant difference between the teriparatide group (6.9%, 12/172) and the BP group (6.8%, 18/272). However, during 6-12 months after surgery, it was significantly lower in the teriparatide group (2.3%, 4/172) than the BP group (9.2%, 24/272) (p&lt;0.05). There was no significant difference in the number of patients showing PS loosening between the teriparatide and BP groups. The teriparatide group showed a significantly higher degree of improvement of the bone mineral density (T-score) than that of BP group (p&lt;0.05). There was no significant difference in the pre- and post-operative VAS and ODI between the groups.

Conclusion

Our data suggest that the teriparatide treatment starting immediately after lumbar spinal fusion surgery could reduce PS loosening compared to BP.

Unusual clinical presentations of cervical or lumbar dorsal ramus syndrome

OBJECTIVE

Patients with cervical (CDRS) or lumbar dorsal ramus syndrome (LDRS) are characterized by neck or low back pain with referred pain to upper or lower extremities. However, we experienced some CDRS or LDRS patients with unusual motor or bladder symptoms. We analyzed and reviewed literatures on the unusual symptoms identified in patients with CDRS or LDRS.

METHODS

This study included patients with unusual symptoms and no disorders of spine and central nervous system, a total of 206 CDRS/LDRS patients over the past 3 years. We diagnosed by using double diagnostic blocks for medial branches of dorsal rami of cervical or lumbar spine with 1% lidocaine or 0.5% bupivacaine for each block with an interval of more than 1 week between the blocks. Greater than 80% reduction of the symptoms, including unusual symptoms, was considered as a positive response. The patients with a positive response were treated with radiofrequencyneurotomy.

RESULTS

The number of patients diagnosed with CDRS and LDRS was 86 and 120, respectively. Nine patients (10.5%) in the CDRS group had unusual symptoms, including 4 patients with motor weakness of the arm, 3 patients with tremors, and rotatory torticollis in 2 patients. Ten patients (8.3%) in the LDRS group showed unusual symptoms, including 7 patients with motor weakness of leg, 2 patients with leg tremor, and urinary incontinence in 1 patient. All the unusual symptoms combined with CDRS or LDRS were resolved after treatment.

CONCLUSION

It seems that the clinical presentationssuch as motor weakness, tremor, urinary incontinence without any other etiologic origin need to be checked for unusual symptoms of CDRS or LDRS.

Superconducting properties of hole doped Ba(0.6)Li(0.4)Fe2As2 single crystal

We report the emergence of superconductivity in Li doped Ba-122 single crystals grown by the Bridgman method. The superconducting transition temperature Tc,onset is around 19 K. The specific heat capacity C/T shows a weak anomaly near Tc. The value of ΔC/γnTc is smaller than the value predicted in BCS theory indicating a multigap nature of the sample. The magnetic measurements show that the lower critical field Hc1(T) exhibits a linear temperature dependence, with a pronounced change of the Hc1(T) curvature around 0.4Tc and Hc1(0) ≈ 430 Oe in the Ba0.6Li0.4Fe2As2 single crystal. Furthermore, temperature dependence of the penetration depth λ(T) follows a power law (~T(n)) below 0.4Tc which predicts possible S±-wave pairing in a Ba0.6Li0.4Fe2As2 superconductor. Over a wide range of temperatures, the Jc(H) exhibits a relation J(c)[proportionality] H(-α) with α = 0.5 ~ 0.6 for H || c and H || ab which indicates random defects in the sample. We found that the temperature dependence of the critical current density Jc(T) can be fitted well with the δl-type pinning model, whose origin is attributed to spatial variations of charge carrier mean free path l. We suggest that the large mismatch in the ionic radius of Ba and Li can affect the irreversible magnetic properties of the Ba0.6Li0.4Fe2As2 single crystal without any structural transition.

Inhibition of BRCA1 in breast cell lines causes the centrosome duplication cycle to be disconnected from the cell cycle

BRCA1-dependent ubiquitination activity regulates centrosome number in several tissue culture cell lines derived from breast cells. In these experiments, we asked how BRCA1 inhibits centrosome amplification. In general, supernumerary centrosomes can accumulate by three mechanisms: (1) failed cytokinesis and the accumulation of centrosomes by duplication in a repeated S-phase of the cell cycle, (2) disruption of the licensing of centrosome doubling such that they duplicate at inappropriate times in the cell cycle, or (3) fragmentation of the centrosomes. In this study, we found that inhibition of BRCA1 caused premature separation of centrioles and reduplication. By blocking cells in early S-phase before centrosome amplification secondary to BRCA1 inhibition could occur and then releasing, we found that inhibition of BRCA1 caused centrosome amplification between late S-phase and G2/M before the cell divided. These results suggest that normal BRCA1 function is critical in these cell lines to prevent centriole separation and centrosome reduplication before mitosis.

Closure of chronic abdominal wall defects: a long-term evaluation of the components separation method

Incisional hernias and abdominal wall defects are frequently iatrogenic problems that have been found to complicate as many as 11% of all abdominal operations. Current techniques for closure of large, chronic abdominal wall defects have limitations. The use of local musculofascial flaps rather than fascial patches (i.e., the tensor fascia lata) or synthetic material for the repair of chronic abdominal wall defects is preferable. The superiority of innervated muscle flaps that provide dynamic abdominal support has been demonstrated. This report focuses on patients with chronic abdominal wall defects in whom previous techniques have failed. An algorithmic approach to planned reconstruction is presented utilizing the "components separation" technique as its foundation. Thirty-seven patients who underwent abdominal reconstruction following this algorithm are reviewed and their clinical course is outlined. The components separation technique provides a compound innervated and vascularized muscle flap for dynamic support of the reconstructed abdominal wall. The experience documented here and by others suggests that this technique is a safe and effective method for reconstructing the abdominal wall in patients with recurrent herniation. Enterocutaneous fistulas, however, continue to present a challenge to the surgeon.

Plastic ankle-foot orthoses: evaluation of function

Plastic ankle-foot orthoses (PAFOs) are worn by persons with hemiplegia to correct gait abnormalities such as foot drop during swing and insufficient pushoff during stance. A PAFO should resist plantarflexion sufficiently to provide toe clearance during the swing phase of gait without excessively increasing the knee bending moment during heelstrike. It should resist dorsiflexion during late stance to raise the heel to simulate gastrocnemiussoleus muscle group function. Five PAFOs were evaluated as to the amount of plantarflexion-dorsiflexion resistance that was provided when worn by hemiplegic and able-bodied subjects. A self-aligning goniometer measured ankle angle as the subject walked, and a gait event marker system recorded occurrences of gait events. The Seattle design polypropylene orthosis which enclosed the malleoli was the least flexible; it provided the greatest plantarflexion resistance to ensure against toe drag during swing for patients with severe plantarflexion spasticity. It offered the greatest dorsiflexion resistance to provide a good substitute for the gastrocnemiussoleus during the latter part of stance as required by patients with flaccid plantarflexors and full ankle range of motion. Progressive trimming of the Seattle design polypropylene orthosis made it more flexible and comparable in function to the commercially available Engen and Teufel orthoses. The latter 2 orthoses did not provide a pushoff substitute as well as the Seattle design orthosis which enclosed the malleoli, but they did provide an adequate amount of toe clearance during swing. The more flexible orthoses would be appropriate for subjects with mild to moderate plantarflexor spasticity.

Knee moments: origin in normal ambulation and their modification by double-stopped ankle-foot orthoses

While the primary function of an ankle-foot orthosis is to stabilize the ankle complex, these devices often cause an unstable knee joint. The effect of a double upright ankle-foot orthosis on knee stability was evaluated during the stance phase of the walking cycle. The external moments applied to the knee in the anteroposterior plane were determined by measuring the ground reaction forces and the position of the knee with respect to these forces. Total knee moment and individual moment contributions of the fore/aft shear and vertical ground reaction forces were analyzed. Moments generated during normal ambulation were compared with those generated by an ankle-foot orthosis with an adjustable double stop. Knee moment components due to fore/aft shear and vertical ground reaction forces tended to counterbalance each other, minimizing the magnitudes of total knee moment. Fore/aft shear moment was most affected by the magnitude of the fore/aft shear force and had the major effect on total knee moment when the fore/aft shear force was peaking during the heel-strike and push-off phases. The vertical force moment was most affected by the length of the moment arm (position of knee center with respect to force) rather than magnitude of force, and had the major effect on total knee moment during midstance phase.

Double-stopped ankle-foot orthosis in flaccid peroneal and tibial paralysis: evaluation of function

This study was undertaken to evaluate how effectively an ankle-foot orthosis can substitute for paralyzed musculature, and to determine the forces it sustains in so doing. Timing of the events of gait, the ground reaction forces, their magnitude and location, and the brace moments were studied. Midstance phase was found lengthened at the expense of push-off phase. During push-off, vertical loading and posterior shear were markedly reduced by tibial block. Also, the dorsiflexion moment in the orthosis was correspondingly increased. The orthosis was found to substitute for muscle function in that it approximates the foot-ankle motion of heel-strike and allows a push-off substitute.