bluuebunny/crossref_metadata_2025 huggingface dataset:
Supine Position after a Major Spine Surgery: A Bad Position
Authors: Costa Camelo Rafael , Valdeci Worm Paulo , Vincent Berthier Brasil Albert
Published: May 2015

Introduction

Patients undergoing spine surgery by the posterior approach are subjected to excessive and constant pressure on the operative site, because decubitus adopted (dorsal) in most procedures, including lying on his back on the injury held recently. The increased pressure on the wound after surgery may lead to tissue ischemia and this fact may explain why patients operated on by posterior approach have higher rates of pain and infection postoperatively. This prospective, controlled study was designed to demonstrate the excess pressure on the muscle of the wound in patients submitted to surgery in the spine by the posterior approach when they assume supine position.

Patients and Methods

A total of 22 patients undergoing major surgery in the thoracic and lumbar regions had a fiber optic catheter (Codman ICP Monitoring System, Jonhson and Jonhson) inserted in to the body (right or left) of the paraspinal muscles. The catheter was inserted 3 cm lateral to the incision and 5 cm deep. The pressure was measured and recorded hourly obeying the order of dorsal decubitus, right and left lateral decubitus for 24 hours postoperatively with the patient at bed rest. After this period the catheter was removed.

Results

Patients had a mean age of 55.9 ± 4.2 years (11 men and 11 women); height of 167.8 ± 2 cm; weight and BMI (body mass index) was 73.0 ± 2 (kg), and 25.3 ± 0.8, respectively. The average abdominal circumference was 93.7 ± 2.7 cm. ANOVA showed a significant difference in mean pressure (24 hours) from the supine position (24.7 ± 2.0 mm Hg) with left or right lateral decubitus (4.92 ± 2.3 mm Hg and 4.77 ± 2.83 mm Hg). There was no significant correlation between weights, sex, BMI, and waist circumference with the pressure of decubitus adopted by the patient, or with the side that the catheter was inserted.

Conclusion

The supine position adopted in the postoperative period of major spine surgery through the posterior approach can be a factor implicated in postoperative complications. The pressure difference is significant enough to exceed capillary pressure.
Cauda Equina Syndrome (CES) Secondary to Lumbar Disc Herniation: Retrospective Clinical Study in 13 Cases with in Progression Symptoms
Authors: Marotta Nicola , Maiola Vincenza , Gregori Fabrizio , Landi Alessandro , Delfini Roberto
Published: May 2015

Introduction

A compression of nerve roots of cauda equina (CE) is responsible for cauda equina syndrome (CES). The nine pairs of CE nerve roots provide motor and sensory innervation to the lower extremity muscles, the pelvic floor, and the bowel and bladder sphincters. CES caused by a massive herniated lumbar disc, has rarely been described in literature. We report 13 cases of massive lumbar disc herniation causing CES which underwent surgical intervention after 48 hours or more from the trauma.

Material and Methods

Between September 2010 and June 2014, 13 cases of CES by lumbar disc herniation were treated in our department. In eight patients the herniated disc level was L4–L5, in one patient was L3–L4, and in four cases was L5–S1. The patients admitted to our hospital had lumbosciatic pain and worsening progressive: motor weakness (seven cases), hypoesthesia to lower limbs (nine cases), sexual dysfunction (two cases), hypo/areflexia (five cases). All the patients before surgery referred sphincter disorders (SD). The surgery was performed in a range from 48 hours to 8 days by the onset of symptomatology. Magnetic resonance imaging (MRI) of the lumbosacral region was performed in all cases before surgery; other postsurgical studies include electromyography (EMG), urodynamic study, RigiScan, and GSA.

Results

The MRI examinations showed a herniated lumbar disc determining a compression on CE. Of 13 patients, 11 had a complete recovery of sphincter disturbances and 8 had a recovery of neurological symptoms in the first day after surgery. Eight patients were discharged in the 3rd day after surgery and had a complete clinical recovery after 1 month from surgery.

Conclusion

CES is characterized by the following symptoms: low back pain, saddle anesthesia, hypo/areflexia, motor weakness or sensory disturbances to lower limbs, sphincter disorders, and sexual disorders. We classified CES according to the onset of symptoms in an acute (symptoms occur within 24 hours) and an in progression form (more than 24 hours). According to the clinical features CES can be classified in a complete (sphincter disorders plus at least four other criteria) and an incomplete form (sphincter disorders and three or less symptoms). Our study is aimed to elaborate a score to better define the preoperative symptomatology and give a prognostic evaluation about neurological recovery. In our experience, despite the fact that surgery has been performed at least 48 hours after the symptoms occurred, we had a complete neurological recovery in 10 out of 13 cases. In case of in progression CES, the surgical intervention, even if it is not performed within 12 hours, can allow a complete neurological recovery, depending on the severity of the clinical features at the time of surgery.
Adjacent Segment Degeneration after Cervical Disc Surgery: Comparison of One-Level Cervical Disc Arthroplasty versus Anterior Cervical Interbody Fusion: 7-Year Radiological Follow-Up
Authors: Szollosi Balazs , Klemencsics Istvan , Lazáry Áron
Published: May 2015

Introduction

Cervical disc arthroplasty and anterior cervical interbody fusion provide the same clinical result in the surgical treatment of degenerative disc disease. The main theoretical advantage of motion preservation is its preventive effect on the adjacent disc degeneration. The aim of our study was to compare the radiological results at the 7-year follow-up after disc replacement and after fusion.

Patients and Methods

Since January 2006 to December 2007, 17 patients underwent one-level cervical disc arthroplasty (group A), and 17 patients were operated with one-level interbody fusion (group B). ROM of the adjacent segment, dimensions of the adjacent intervertebral disc space, ROM and alignment of the whole cervical spine, and presence of heterotopic ossification were evaluated preoperatively and at 7-year follow-up. All the measurements were done by independent radiologist on the digital anteroposterior, lateral, and flexion/extension X-rays.

Results

The adjacent disc height decreased in both groups, but the decrease was more significant in the fusion group. Mean disc height was 4.13 mm (preoperative) and 4.03 mm (postoperative) in group A, and 4.02 mm (preoperative) and 3.83 mm (postoperative) in group B. The sagittal ROM of the adjacent segment was higher in the arthroplasty group (group A: 10.89 degrees, group B: 9.5 degrees). The cervical lordosis was significantly higher in the fusion group (group A: 11.81 degrees, group B: 18.59 degrees, p < 0.05). In the arthroplasty group, the mean ROM of the operated level was 11.4 degrees preoperatively and 11.12 degrees postoperatively ( p > 0.05). A total of 64.7% of the patients had any sign of heterotopic ossification.

Conclusion

The segment of the prosthesis ultimately showed preservation of the preoperative motion. The decrease of the intervertebral disc height, and the ROM (flexion/extension) in the adjacent segments was more significant in the fusion group, so the disc degeneration process seems to be faster after fusion than arthroplasty. The restoration of the lordosis is more effective with fusion than arthroplasty. The early experience is promising but long-term follow-up studies are required to prove the theoretical advantages of the arthroplasty in the prevention of the adjacent segment degeneration.
Long-Term Results after Cervical Disc Replacement using Bryan Prosthesis
Authors: Amro Nahed , Badke Andreas , Jarrar Dina , Schätz Christoph
Published: May 2015

Study Design

Retrospective clinical study.

Objective

To study the outcome of cervical disc replacement with a Bryan prosthesis in 60 to 91 months follow-up duration through analyzing the motion of index segments and associated heterotopic ossification (HO), and adjacent segment degeneration using their motion, patient satisfaction, and pain as indicators.

Summary of Background Data

Cervical disc replacement is considered to be equivalent if not superior to discectomy and fusion because it allows for decompression while maintaining segmental motion and has the potential to minimize adjacent segment disease. However, long-term results of motion and degeneration of adjacent segments after cervical disc replacement are rare.

Methods

Data of 47 patients with cervical disc prolapse, treated with cervical disc replacement with a Bryan disc between January 28, 2002 and October 31, 2003 in the orthopädische Klinik Markröningen, Germany were analyzed. Cobb angles of the exchanged segment, and the adjacent segments were measured on pre- and postoperative radiographic pictures. The grade of heterotopic ossification was examined. The postoperational functionality of the cervical spine was examined via active range of motion. Patients' satisfaction and pain were assessed using; the neck disability index (NDI), Odom criteria, and visual analog scale (VAS).

Results

At follow-up no postoperative complications or revision were recorded. No HO formation was present in 34 patients (72.3%), grade I and grade III HO was present in 10 patients (21.3%) five of each grade. Segmental fusion (grade IV) was observed in three patients (6.4%). Most patients showed improved motion and high satisfaction. Mean NDI was 12.3% (SD = 13.12). Mean VAS score was 1.8 (SD = 2.1). Using Odom criteria all patients were classified as a clinical success.

Conclusions

Preserving stability (as a nonresorbable stable place holder) and the goals of decompression, cervical disc replacement preserved motion, and decreased related degeneration clinically and radiologically.
Improvement in Disc Height after Lumbar Arthroplasty with Mobidisc and Minimum 3 Years of Follow-Up
Authors: Vujadinovic Aleksandar , Hrustic Asmir , Dakheel Aldakheel Dakheel
Published: May 2015

Introduction

Degenerative disc disease (DDD) is one of the most common reasons for low back pain in active population. During process of degeneration disc loose water content that leads diminishing of disc height. Disc degeneration is characterized by loosening of water content. These leads to diminishing of disc height, higher stress to facet joints and narrowing neural foramina. The aim of this study is to evaluate improvement in disc height after total lumbar arthroplasty at L4–L5 and L5–S1 segments with a Mobidisc prosthesis.

Patients and Methods

We analyzed 63 patients in which Mobidisc lumbar prosthesis were implanted at L4–L5 and L5–S1 segments during period of January 2008 to January 2011 in Civil Hospital in Strasbourg, France. Full standing X-rays have been done preoperatively and postoperatively after 6 weeks, 3, 6, 12, and 36 months. X-rays were digitalized and measurement were performed by using Spineview software. Measurement was statistically significance at p < 0.05.

Results

The mean follow-up was 44 months; 45 females and 18 males were analyzed with average 41.3 year of age. Prosthesis was implanted at L4–L5 in 19 cases and at L5–S1 in 44 cases. Preoperative anterior disc height at L4–L5 was significantly improved, from 6.30 to 9.03 mm (2.73 mm) postoperatively ( p < 0.01). Posterior disc height at same level was also improved, from 2.82 mm preoperatively to 3.90 mm postoperatively (1.08 mm) ( p < 0.05). At level L5–S1 anterior and posterior disc height were improved as well. From 4.99 mm to 7.53 mm (2.54 mm) ( p < 0.05) and from 2.52 mm to 4.66 mm (2.14 mm), respectively, ( p < 0.05).

Conclusion

During lumbar disc arthroplasty the size of prosthesis may have a significant role in a final postoperative result. Oversize prosthesis may produce too much distraction to posterior ligaments and muscles of lumbar spine. On the other hand, too small implants will not reduce stress enough on facet joints nor will adequately open neural foramina. In both cases, this would probably result in painful syndromes of lumbar spine.
Sacroiliac Joint Syndrome 10 Years after Lumbar Arthroplasty: The Importance of Spinopelvic Alignment
Authors: Ciarpaglini Riccardo , Maestretti Gianluca
Published: May 2015

Introduction

Sagittal balance is an independent predictor of outcomes in spinal care and several authors focused their attention on the lumbar lordosis restoration as the key point to prevent secondary sacroiliac joint dysfunction (SIJD) after fusion. On the other hand, lumbar disc arthroplasty allows preservation of motion avoiding increased stress on the spinopelvic junction and preventing iatrogenic sagittal imbalance.

Methods

We analyze the incidence of a secondary SIJD and the spinopelvic alignment on a series of 31 consecutive lumbar disc prosthesis with a 10-year follow-up.

Results

Sagittal balance assessment showed no significant variation of preoperative spinopelvic parameters. Four patients (12%) presented a symptomatic SIJD. Only two of them required a percutaneous SIJ fixation. Both of them presented a fused L5–S1 prosthesis.

Conclusions

Very few studies are focused on the topic of SIJ deterioration after lumbar arthroplasty and, at the best of our knowledge, the present article is the first with such a long follow-up. After 10 years of the surgery 12% of our patients presented a symptomatic SIJ dysfunction, less than the percentage reported in the literature after lumbosacral fusion. The low rate of SIJD 10 years after lumbar arthroplasty might be explained by the preservation of the spinopelvic balance.
Early Results of Magnetically Controlled Growing Rods in the Management of Early-Onset Scoliosis
Authors: La Rosa Guido , Ruzzini Laura , Oggiano Leonardo
Published: May 2015

Introduction

To present a series of nine patients with early-onset scoliosis (EOS) managed with magnetically controlled growing rods (Ellipse TM MAGEC System).

Material and Methods

We implanted magnetically controlled growing rods in nine patients affected by early-onset scoliosis. Scoliosis and Kyphosis angles, T1–T12, and T1–S1 distances were evaluated preoperatively, postoperatively, and at the last follow-up. A visual analogue scale score was used to evaluate pain during outpatient rod distraction procedures. The mean follow-up is 24.5 months. All patients attended distractions of the magnetic rod through an external remote control every 3 months.

Results

The mean Cobb angle value was 66.3 ± 17.6 degrees (range, 45–100 degrees) preoperatively and 30 ± 13.8 degrees (range, 15–59 degrees) at the latest follow-up. The mean T1–S1 length value was 27.2 ± 5.7 cm (range, 16–34.8 cm) preoperatively and 33.2 ± 4 cm (range, 26.5–39 cm) at the latest follow-up. The mean T1–T12 length value was 16.3 ± 2.9 cm (range, 10–19 cm) preoperatively and 20.9 ± 2.9 cm (range, 15.5–23.5 cm) at the latest follow-up. The average monthly T1–T12 height increase was 0.8 mm while the average monthly T1–S1 increase was 0.9 mm. Two patients experienced a rod breakage and one patient had a pullout of the apical hooks.

Conclusion

Although implant-related complications could occur, magnetically controlled growing rods can be effectively used in patients with EOS. This spinal instrumentation can overcome many of the complications related with the traditional growing rods implants. This procedure can be effectively used in outpatient settings, minimizing surgical scarring, and psychological distress due to multiple surgeries needed in the traditional growing rods system, improving quality of life, and saving health care costs.
XLIF-Related Postoperative Events versus Psoas Muscle Dimension and Ratio: A Possible Preoperative Evaluation Factor
Authors: Buric Josip
Published: May 2015

Introduction

Advanced intraoperative neuromonitoring (IONM) is used to attenuate postoperative complications and side effects of extreme lateral interbody fusion (XLIF). Specific factors relate to the presence of postoperative injury are not well understood. This study aims to identify intraoperative variables with correlations to new postoperative anterior thigh/groin sensory changes.

Patients and Methods

A total of 29 patients with various degenerative lumbar conditions were treated with XLIF at a single institution. Mean age was 59 years, 69% were females, and 21% had undergone previous lumbar surgery. A total of 47 levels (mean 1.6, range 1–3) were treated with XLIF. Supplemental pedicle screw and rod fixation was used in 24 patients (83%). Dynamically evoked electromyography was used in all cases. Analysis of baseline demographic and treatment variables were performed at a per patient basis ( n = 29), whereas analysis of intraoperative variables were performed at a per levels treated basis ( n = 47).

Results

Within 24 hours postoperative, 10 (34%) patients experienced anterior thigh/groin sensory changes (4 reported pain only, 5 reported pain plus other sensory changes, and 1 paresthesia without pain). Symptom resolution occurred at 1 month postoperative for four patients, at 3 months postoperative for two patients. At 3 months postoperative, six patients had complete symptom resolution, three patients had symptom improvements, and one patient had no change in perioperative symptoms. Psoas dimension in the lateral–latero direction were significantly smaller for patients with postoperative sensory changes ( p = 0.025), and similarly, patients with postoperative sensory changes had a significantly higher ratio of psoas muscle in the anterior–posterior to lateral–latero directions ( p = 0.026).

Conclusion

In addition to IONM, MRI evaluation of psoas shape, position, and dimension may be of help in preoperative planning of a safe XLIF access and eventually, predict those cases with higher risk of approach-related postoperative events.
Comparative Analysis about Efficacy, Security, and Manageability of Gelified Hemostatic Matrix in Bleeding Control during Thoracic and Lumbar Spine Surgery: Floseal versus Surgiflo
Authors: Gregori Fabrizio , Landi Alessandro , Marotta Nicola , Delfini Roberto
Published: May 2015

Introduction

An accurate hemostasis in surgical practice is as important as reduced the dimensions of the operating field are. The need of an optimal, atraumatic hemostasis has become impelling in neurosurgery. Gelified hemostatic matrix has been employed very often because of their simple and safe use. This prospective study is aimed to comparatively evaluate two different hemostatics, Floseal and Surgiflo, in the bleeding control during spine surgery, considering their efficacy, security, and ease of use.

Material and Methods

From January 2012 to December 2013, 149 patients were recruited for this study. Inclusion criteria were: age between 25 and 80 years, diagnosis of arthrosic or traumatic pathology of lumbar or thoracolumbar spine, persistent bleeding not responding to standard hemostatic techniques. All patients required laminectomy or laminoartrectomy, with exposure of the perivertebral venous plexus. Aim of our study was to reach a complete stop of the bleeding in the operatory field after the application of hemostatic gel. All patients have been evaluated during the follow-up period with clinical and neurological examination after the intervention. All patients underwent a CT scan 3 months after the intervention.

Results

We included 149 patients in our study: 98 men and 51 women. A total of 92 patients were affected by a degenerative condition, 57 by traumatic pathology. A total of 42 patients assumed anticoagulant and/or antiaggregant therapy preoperatively. In all cases, a massive bleeding originated from the epidural venous plexus. Floseal was used in 86 cases, Surgiflo in 63. A complete hemostasis was achieved in all patients in a time included between 3 minute 30 second and 7 minute (Floseal 5 minute 35 second ± 52 second, Surgiflo 5 minute 32 second ± 54 second). Statistical analysis did not show any association between coagulation time and hemostatic, age, sex, pathology treated. A previous therapy with antiaggregants and/or anticoagulants determined a slight increase in time of hemostasis without any statistical difference. The clinical and radiological follow-up showed no evidence of postsurgical hematomas.

Conclusion

Comparative analysis of the two products did not show any relevant difference in terms of efficacy and ease of use, showing their effectiveness in the bleeding control. Their use has been valid even in patients who made use of antiaggregant/anticoagulant drugs preoperatively. Both Floseal and Surgiflo can be considered a valid instrument in controlling bleedings in thoracic and lumbar spine surgery.
C2 Subfacetal Body Screw in Posterior Atlantoaxial Fixation (Goel–Harm Technique) to Avoid the Vertebral Artery
Authors: Sushil Patkar
Published: May 2015

Introduction

Axis (C2) pedicle/pars screw fixation has a definite risk of injury to the vertebral artery. An alternative trajectory 3 mm below the midpoint of the C2 facet surface, directed, downwards and medially into the C2 body, bypasses the vertebral artery altogether, and still offers adequate bone stock for rigid fixation of the C2 vertebra.

Material and Methods

Overall, 65 patients, 40 males and 25 females, aged 12 to 82 years, underwent posterior C1–C2 fixation from February 2007 to June 2014. Reducible atlantoaxial instability due to trauma (35), rheumatoid arthritis (20), and infection (tuberculosis) (10), magnetic resonance imaging (MRI), dynamic lateral X-rays of craniovertebral junction (CVJ), 3D CT scan of the craniovertebral region along with dynamic study and CT angiography. The entry point for the C2 screw was 2 to 3 mm below the midpoint of superior facet of the C2 which is also the midpoint C1–C2 joint and directed 10–to 15 degrees medially and downwards into the body of the axis. The same 3-mm drill bit was used incrementally till a depth of 5 mm and, 3.5 mm and 18 to 24mm length self-tapping screw with polyaxial head was used in most cases.

Results

No case of intraoperative vertebral artery injury. No patient required per operative blood transfusion. Follow-up visits were scheduled at 2, 6 to 8 weeks, and 3 months. Dynamic X-ray imaging was done in all patients at 6 to 8 weeks before discontinuing the collar and after 3 months since the operation. All patients followed up for 3 months. Telephonic follow-up of 30 patients was available for 24 months, 12 patients for 6 months, and remaining 7 patients have not reported and are not contactable after the 3 month visit. One postoperative mortality due to myocardial infarction on 7th day. Seven patients complained of occipital numbness and paresthesia which was not disturbing and responded to reassurance and supportive medication (pregabalin). Two patients had superficial wound infection which responded to appropriate antibiotics. There was no case of implant failure or loss of rigidity of fixation up to 3 months.

Conclusion

The new entry point offers rigid fixation and avoids the vertebral artery altogether nullifying the chance of arterial injury. Divergent screws (bridge vs. tension band construct) have a greater pull out strength. The new technique of C2 screw fixation allows rigid immobilization of the C1–C2 joint without any risk of vertebral artery injury.
Observation of Intraoperative Visual Evoked Potential Monitoring during Prostrate Spinal Surgery
Authors: Cui Zhiming , Bao Guofeng
Published: May 2015

Introduction

In order to provide the theoretical basis and practical guidance of eye protection during the prone spinal surgery under the general anesthesia, visual evoked potential (VEP) was monitored before and after surgery.

Patients and Methods

A total of 82 patients were involved in our study and grouped into three groups, S, M, and L groups, respectively, according to the operation time. The P100's latency and amplitude changes and the visual function of preoperative, postanesthetic, and postoperative spots were analyzed to understand their relationship.

Results

(1) The waveforms of VEP in 78 cases were monitored stably and repeatedly and the other four cases failed. (2) Difference of P100's latency and amplitude at preoperative, postanesthetic time was not statistically significant in all groups. (3) Postoperatively, difference of P100's latency was statistically significant in M and L groups, and no statistically significant difference was observed in S and M groups. Difference in P100's amplitude was statistically significant in all groups. (4) Recovery time of P100's latency has statistically significant differences in all three groups. (5) Two patients in the L group had conjunctival edema, pupillary light reflex obstacles, and visual acuity descending. After receiving positive symptomatic treatment, symptoms disappeared and vision recovered.

Conclusion

VEP can provide the stable and on-time electrophysiological conductive evidence needed to judge the optical pathway function. The operator should pay close attention to the change in VEP and visual performance if prone spinal surgery continues for more than 4 hours.
Locomotor Improvement after Spinal Cord Injury by Multiple Injections of Bone Marrow Mononuclear Cells without Local Inflammatory Modulation
Authors: Bonatto Francine , Falavigna Asdrubal , DaCosta Jaderson
Published: May 2015

Introduction

Currently, the recovery of neurological functions after spinal cord injury (SCI) still relies on the host's neural plasticity and compensatory mechanisms. Unfortunately, many of these patients are permanently paralyzed. The objective of the study was to compare the results of treatment groups with 3 and 5 applications of bone marrow mononuclear cells (BMMC) in the subarachnoid space through a lumbar puncture in a rat SCI model. Subsequently, the motor function and inflammatory rate at the site of injury were analyzed.

Materials and Methods

The study design was an experimental animal study of SCI, using a stem cell (SC) delivery system. The experiment was done using an animal model of thoracic SCI with aneurysm clip compression. Afterwards, these animals were treated with 3 (BMMC3) or 5 (BMMC5) applications of BMMC directly into the subarachnoid space using a lumbar puncture. The control group received saline solution (SS) that was injected at the same time and frequency (SS3 and SS5) used for BMMC delivery. The animals were sequentially evaluated for motor function using the BBB scale for the presence of BMMC in the lesion by PCR, and the local inflammatory rate through interleukin (IL-1β) and tumor necrosis factor α (TNF-α), which were analyzed by immunohistochemistry.

Results

The BMMC5 group showed significant differences in motor scores over the entire study when compared with their SS5 control group. At the end of the treatment, there was a similar motor performance when both treatment groups (CMM3 vs. BMMC5) were analyzed. In both treatment groups and their control there was no difference in the inflammatory rate. The PCR could not detect the presence of BMMC at the injury site.

Conclusion

Multiple administration of BMMC in the subarachnoid space through lumbar puncture improves locomotion without showing local inflammatory modification.
The Influence of Spinal Deformity on Acetabular Orientation in Total Hip Arthroplasty
Authors: Phan Duy , Bederman Samuel S. , Schwarzkopf Ran
Published: May 2015

Introduction

The interaction between the lumbosacral spine and the pelvis is complex. This interface is further complicated by preexisting pathology and by positional change. Our study examines the influence of spinal deformity on positioning of total hip arthroplasty (THA). A guideline is provided to assist in preoperative planning and improved communication between hip and spine subspecialists.

Materials and Methods

A comprehensive literature review was conducted investigating the relationship at the spinopelvic junction. Specific topics examined included methodology to measure acetabular and spinal orientation, acetabular anteversion (AA) with spinal imbalance and rigidity, hip functional range of motion with positional change, and hip functional range of motion after THA. Information and results that were consistently sourced were used to create specific recommendations for the hip and spine subspecialists. Both schematic and visual representations of the different recommendations were constructed.

Results

There is a predictable change in sagittal acetabular orientation that is influenced by lumbosacral balance and flexibility as well as by positional change. Preoperatively, patients in need of THA can be screened with sitting and standing lumbar radiographs into four categories based on flexibility and sagittal balance of the spine: flexible/balanced, flexible/unbalanced, rigid/balanced, and rigid/unbalanced. Patients in the flexible/balanced category should have AA during THA in the standard safe zone of 5 to 25 degrees. Patients with spinal rigidity will require adjustment of AA to limit impingement and dislocation. Patients with spinal imbalance, whether rigid or flexible, will be best addressed by spinal realignment or alternatively may require adjustment of AA to accommodate for compensatory pelvic retroversion.

Conclusion

Sagittal imbalance of the lumbar spine, combined with spinal fusion or ankylosis from degenerative changes, influences AA during THA. Patients can be preoperatively screened into four different categories based on lumbosacral balance and flexibility. Acetabular cup placement can be optimized based on the type and significance of coexisting spinal deformity to increase hip functional range of motion. Spinal realignment should be considered primarily for unbalanced patients before THA to ensure ideal placement of the acetabular cup.
The Efficacy and Accuracy of Cone Beam CT (O-Arm) Navigation (StealthStation) on Screw Position in Adult Scoliosis Surgery
Authors: Strelzow Jason , Mendelsohn Danny , Dea Nicolas , Fisher Charles , Dvorak Marcel , Street John
Published: May 2015

Introduction

Intraoperative CT and navigation systems may provide an opportunity to improve precision and accuracy of pedicle screw placement, and in so doing, improve patient outcomes. Adult spinal deformity provides unique anatomical challenges potentially amenable to spinal navigation. Our study aimed to examine the efficacy and safety of intraoperative cone beam CT navigation for pedicle screw placement in complex spinal deformity cases.

Material and Methods

We identified all patients treated at our institution with spinal fusion for the primary diagnosis of major adult deformity between January 2008 and December 2012 in whom O-arm and StealthStation navigation was used (NAV). A historic control cohort (non-NAV) was matched based on age, number of levels, curve type and size, and previous fusion. The number and timing (intraoperative, early symptomatic postoperative, late symptomatic postoperative, and incidental) of screw malposition and the need for revision screw placement were recorded. All patients had a minimum follow-up of 1 year. Any screw with pedicle breach greater than 0 mm was recorded as misplaced. The direction and anatomical level of misplaced screws were also determined. Quantitative statistical analysis compared screw placement between NAV and non-NAV cases.

Results

A total of 56 patients met the inclusion criteria in both cohorts (112 patients). The mean number of screws placed in each group was not significantly different (17.29 in NAV and 17.71 in non-NAV, p = 0.75). Thirty-eight (34%) patients in the non-NAV group had misplaced screws compared with 21 (19%) in the NAV group ( p = 0.002). The detection of incidental screw malposition was significantly higher in the non-NAV cases (44.6 vs. 23.2%, p < 0.05) and the need for intraoperative screw revision favored navigation ( p < 0.03). Six cervical screws, 16 cervicothoracic, 90 thoracic, and 112 lumbar screws were placed. Early postoperative screw revision rates approached significance ( p < 0.06) favoring navigation. The number of adverse events and length of stay (mean 17 vs. 20.4 days in NAV and non-NAV groups, respectively) were not significantly different. The mean number of postoperative CT scans was significantly fewer in the NAV group (9 vs. 22 in non-NAV group, p = 0.004), while mean OR time was statistically different between groups (492 minutes in the NAV group vs. 408 minutes in the non-NAV, p = 0.002).

Conclusion

Our results demonstrate that intraoperative CT-guided navigation provides an equally safe and more accurate and precise tool for pedicle screw placement than traditional techniques in adult spinal deformity surgery. There were more intraoperative screws adjusted and fewer postoperative screws revised with NAV. Far fewer patients required postoperative CT examination with the use of NAV.
Laser Modified PEEK Implants as an Adjunct to Interbody Fusion: A Sheep Model
Authors: Briski David C. , Zavatsky Joseph M. , Cook Brandon W. , Ganey Timothy
Published: May 2015

Introduction

Advances in laser technology have been used to imprint mimetic surface patterns on PEEK implants that mirror isotropic bone in an attempt to enhance fusion. In vitro cell culture analysis suggests that laser surface etching enhances the deposition of matrix and preferentially encourages the attachment of bone. We evaluated the effect of mimetic patterning on PEEK cages on fusion in a sheep model. The aim of the study is to evaluate mimetic patterning on a polyether ether ketone (PEEK) cage as an innovative and alternative method to achieve solid interbody fusion in a sheep model.

Methods

PEEK implants were developed using advanced laser technology to produce a surface mimetic that was analogous to isotropic bone. Following IACUC approval, identical implants were placed in 20 sheep using an anterior approach to C3–4 with supplemental plating. Sheep were divided into four groups: Group 1, mimetic patterning without autograft; Group 2, mimetic with autograft; Group 3, no mimetic patterning with autograft; Group 4, no patterning without autograft. Sheep were analyzed at 3 and 6 months by radiography, CT, MRI, and histopathology. Nine sheep were sacrificed at 3 months for micro-CT and histological analysis. At 6 months, the remaining 11 sheep were analyzed.

Results

Radiographs and viable CT scans of all 20 sheep at 3 months demonstrated the greatest radiographic evidence of fusion in Group 1 (mimetic without autograft). Micro-CT and histological data were available in the nine sheep that were sacrificed at 3 months. Group 1 demonstrated more abundant mineralized matrix and bony attachments at the implant's mimetic surface interface consonant with fusion. The 11 sheep available for analysis at 6 months sustained evidence of lamellar bone formation adjacent to the implant, reduction in fibrosis, and a more cellular and highly vascularized bone.

Conclusion

Surface modification of PEEK spinal implants with a pattern and topography that mirrored isotropic bone enhanced fusion in a large animal model. In vitro cell culture analysis had suggested that laser surface etching boosted the deposition of mineralized matrix and preferentially encourages the attachment of bone cells. Three-month micro-CT and histological data, extended to additional corroboration at 6 months by both radiography and histology, confirmed these findings in the sheep model. Abundant mineralized matrix and bony attachment were found at the mimetic surface interface of the implant suggesting fusion in Group 1 in this sheep model.
The Specific Features of Logistic Regression Curves That Can be Used for Classification of Cases and Decision-Making
Authors: Bokov Andrey
Published: May 2015

Introduction

Logistic regression analysis is frequently used to estimate the relationships between dichotomized dependent variable and continuous independent variable; however, even an evidence of highly significant relationship could be insufficient for the decision-making. Thorough analysis of event probability growth patterns could be helpful to classify cases and to determine cut-off criterions that could be based on critical points of the graph corresponding to the changes in the velocity of event probability growth per unit of predictive variable. The objective is to study the specific features of logistic regression curves to evaluate those critical points.

Materials and Methods

A total of 15 logistic regression functions estimated during scientific studies were analyzed. Points in the graph that correspond to the changes in velocity of probability growth per unit of predictive variable were estimated using second, third, and fourth derivatives of estimated logistic regression functions. The calculated values were then used for predictive variables corresponding to zero points of derivatives to calculate the respective probability values applying estimated previous logistic regression function. Finally, the structure of logistic regression graphs was analyzed and divided into several parts as shown in Fig. 1.

Results

Typical logistic regression curve is shown in Fig. 1. It was revealed that logistic regression function graphs have the same structure. Point A corresponds to zero point of second derivative, the value of corresponding probability is 0.5. B and B1 points correspond to zero values of third derivative, the values of probability are 0, 21132 and 0, 0.788675, respectively. C and C1 correspond to zero points of fourth derivative and the corresponding probability values are 0.091751 and 0.90824, respectively. Up to point C, there is a baseline of the event with a minor velocity of probability growth. Part of the graph (from point B to C) represents the initial increase in velocity of probability growth, while the one from B to B1 represents maximal velocity of probability growth per unit of predictive variable.

Conclusions

This type of analysis can be applied to decision-making, while it is possible to reveal borders for part of the graph that is indicated as B–C part in Fig. 1. This part of the graph corresponds to the initial acceleration in probability of event growth per unit of predictive variable (e.g., the onset of the disease); consequently, those patients should be put under observation. Further shifts of predictive variable value to the B–B1 part of the graph should be taken under consideration and appropriate treatment should be applied as the velocity of probability growth becomes maximal. The example for this analysis application could be a relationship between low energy vertebra fractures rate and bone density.
Radiographic and Functional Evaluation of the Iliac Bone Graft in the Treatment of Adolescent Idiopathic Scoliosis
Authors: Fernando Franzin , Gotfryd Alberto , Neto Nicola , Poletto Patricia , Milani Carlo , Mattar Thiago , Rodrigues Luciano
Published: May 2015

Introduction

This study aimed to assess the impact of the use of an additional iliac bone graft on functional and radiographic results after thoracic spine arthrodesis with pedicle screws in patients with adolescent idiopathic scoliosis.

Patients and Methods

Participants were divided into two groups: a control group that received only local bone (CG; n = 19) and a second group that, in addition to this procedure, received an iliac graft (IG; n = 22). The evaluations were performed on preoperative, immediate postoperative, and last follow-up (mean 29.7 months; minimum 12 months). Radiographic evaluations included the loss of correction and the presence of nonunion. The functional outcome was evaluated using the Scoliosis Research Society-30 questionnaire. Surgical complications and the presence of iliac donor site pain were also described.

Results

There were no significant differences between groups in the pseudoarthrosis rate, loss of correction over time, and quality of life. The loss of correction was 5.9% in IG and 7.5% in CG ( p = 0.504). There was one case of pseudoarthrosis on IC and consolidation rate was 95.4% in IG and 100% in the CG ( p = 0.537). Functional evaluation, using the SRS-30 questionnaire, showed no differences between groups. At the end of follow-up, all the patients of both groups presented good scores regarding satisfaction with the treatment.

Conclusion

We concluded that the addition of bone graft from the iliac yielded no benefit in terms of the fusion rate and functional outcomes. The appropriate facetectomy, bed preparation, and filling with a local bone graft must be adequate to achieve an adequate fusion on surgical treatment of adolescent idiopathic scoliosis.
Determinants of Lumbar Curve Behavior in Lenke Type IA and B Thoracic Adolescent Idiopathic Scoliosis Treated by Posterior Spinal Fusion
Authors: Elmalky Mahmoud , Arealis George , Grevitt Michael
Published: May 2015

Introduction

Study design: prospective.

Objectives

To assess lumbar curve behavior in Lenke IA and B curves treated by selective thoracic posterior fusion. Test hypotheses were that spontaneous lumbar curve correction (SLCC) would be better with smaller initial deformities, in more flexible curves, and of greater magnitude with higher metal density.

Summary of Background Data

There are different and often conflicting recommendations regarding selection of lowest instrumented vertebra and best approach which provides the greatest SLCC. All-pedicle-screw constructs and increasing metal density are recent trends. However, few reported the fate of the residual unfused lumbar curve.

Material and Methods

Thirty-three patients with AIS Lenke 1A/B (single surgeon) were included with a minimum follow-up of 2 years. Mean age was 14.2 years (9–19 years). All had all-pedicle-screw constructs with mean metal density of 58% (36–75%). The mean fused level was 10.3.

Results

The mean thoracic Cobb angle for preoperative, immediate postoperative, at 1-year, and final follow-ups were 60.6, 15.5, 15.9, and 17.2 degrees, respectively (mean flexibility 49.4% [10–96%]). Lumbar curve preoperative mean Cobb angle was 29.6 degrees (14–53 degrees) (mean curve flexibility 79% [40–96%]). Cobb angle at immediate postoperative, 1-year, and 2-year follow-ups were 9.2, 8.9, and 9.4 degrees, respectively. The mean lumbar lordosis angle preoperatively and at final follow-up was 57.3 and 55.9 degrees. Maximum SLCC was achieved within 6 weeks and maintained throughout. No lumbar decompensation was noted. There was significant correlation between the percentage correction of the thoracic curve and SLCC percentage ( p = 0.027). There was no significant correlation between SLCC and the preoperative thoracic curve magnitude ( p = 0.16). Similarly, there was no correlation between metal density and SLCC ( p = 0.62). The patients were divided into two groups according to the flexibility (< 40 and ≥ 40%). There was no correlation between the SLCC and curve flexibility.

Conclusion

Our results demonstrate that in Lenke IA and B curves treated with selective pedicle-only posterior fusion, there were no decompensation, lumbar curve was corrected significantly, and SLCC was completed within 6 weeks and maintained. Lumbar lordosis remained normal. The percentage of lumbar curve correction was neither associated with its initial Cobb angle magnitude nor flexibility. Finally, magnitude of preoperative thoracic curve, latter curve percentage correction, and metal density did not affect SLCC.
Efficacy of Electromyography in Identification of Pedicle Screw Position in Adolescent Idiopathic Scoliosis
Authors: Pratali Raphael , Barsotti Carlos Eduardo , Gavassi Bruno , Ferreira Ricardo , Oliveira Carlos Eduardo
Published: May 2015

Introduction

Pedicular screw has become the most popular device in spine surgeries, especially in the treatment of adolescent idiopathic scoliosis (AIS). They lead to better curve correction in coronal, sagittal, and rotational planes, shorter constructions, and better pulmonary function compared with other devices. Despite those advantages, this technique is potentially dangerous. Intraoperative neuromonitoring is frequently used to detect the misplacement of screw and reverse possible neurological complications. The aim of this study is to analyze the relation between electromyographic records of the inserted screws and their position by postoperative CT scan.

Materials and Methods

This is an observational prospective study which includes 16 patients undergoing AIS surgical correction between March and December 2013 at one institution. All procedures were monitored with electromyography (EMG) of the inserted screws and the stimulation threshold of each screw was recorded. Those values were compared with the position of the screws, based on the postoperative CT scan, according to the classification proposed by Abul-Kasim et al.

Results

Included were 16 patients with 281 pedicles instrumented (17.5 per patient). No patient presented with any neurological deficit or complaints after surgery. In the axial plane, 195 screws were ideally inserted in the pedicles (69.4%) and in the sagittal plane, 226 screws were ideally inserted in the pedicles (80.4%). Considering both the axial and sagittal planes, 166 (59.1%) did not breach any pedicular cortical wall. No statistical correlation was observed between EMG threshold and screw position in the axial CT-scan position, as in the medial or lateral misplacement ( p = 0.425), but statistical significant correlation was observed between EMG threshold and screw position in the sagittal CT-scan position, with smaller results when the screws were misplaced inferiorly, closer to the foraminal roots ( p = 0.017).

Conclusion

Pedicular screws were safe in this AIS surgery series, even with misplaced position. EMG monitoring has shown to be efficient in identifying misplacement of pedicle screws in the sagittal plane (inferior foraminal perforation) but not so much in identifying the axial plane misplacement (lateral or medial).