Spinal cord cross-sectional area during flexion and extension in the patients with cervical ossification of posterior longitudinal ligament

Purpose

The pathomechanism of cervical myelopathy due to cervical ossification of posterior longitudinal ligament (C-OPLL) remains unclear. No previous literature has quantified the influence of dynamic factors on cervical myelopathy due to C-OPLL. The purpose was to investigate the influence of dynamic factors on the spinal column in the patients with C-OPLL using CT scan after myelography (MCT).

Methods

The study included 41 patients with cervical myelopathy due to C-OPLL. An MCT was done during neck flexion and extension, and spinal cord cross-sectional areas (SCCSA) were measured at each disc level between C2/3 and C7/T1. Ossification morphology at each segment was divided into three groups, connection department, coating part, and non-connection department of OPLL group. Dynamic changes of SCCSA in each group of ossification morphology were calculated. The relationship between clinical results and SCCSA at the narrowest level was investigated.

Results

MCT showed SCCSA changes during neck extension; 7.4 ± 5.1 mm² in the connection department, 5.8 ± 6.0 mm² in the coating part, and 6.7 ± 6.4 mm² in the non-connection department of OPLL group. There difference was not statistically significant. There was a weak correlation between the JOA score and SCCSA at the narrowest level (R = 0.49). There was no significant correlation between the recovery rate of JOA score and SCCSA at the narrowest level (R = 0.37).

Conclusion

Dynamic factors are seen both in cervical myelopathy patients with the continuous type of OPLL and others. Deterioration of myelopathy could be induced by motion effects even in the connection department of OPLL.     

Cervical curvature, spinal cord MRIT2 signal, and occupying ratio impact surgical approach selection in patients with ossification of the posterior longitudinal ligament

Objective

Factors impacting surgical options and outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) were explored.

Methods

A retrospective analysis was conducted of 127 eligible cervical OPLL patients (61 males, 66 females) aged 41–70 years (mean 55.2 years) selected from 152 total OPLL patients treated from 2002 to 2006, with 5–10-year (mean 6.8 years) follow-up. Patients underwent anterior subtotal corpectomy with ossification ligament resection (anterior surgery, n = 68) or posterior cervical double-door laminoplasty (posterior surgery, n = 59). Radiographic assessments of cervical curvature, T2-weighted MRI (MRIT2) signal, and OPLL occupying ratio were correlated with surgical strategy before surgery and at 1, 5 weeks, and 5 years.

Results

Lordosis increased following anterior surgery, though kyphosis improved by 10.3 %. The canal stenosis occupying ratio was >50 %, and short-term improvement following anterior surgery was significantly higher than posterior surgery (P > 0.0001). Superior neurological function was observed in patients with unchanged versus high spinal MRIT2 signals (P = 0.0434). No significant differences were observed in short-term outcomes between anterior and posterior surgeries in high spinal MRIT2 signal patients, but anterior surgery produced significantly better long-term outcomes at 1 week (P = 0.7564) and 1 year (P = 0.0071). Complications occurred in five anterior and three posterior surgeries.

Conclusion

Preoperative assessment of cervical curvature, MRIT2 signal, and occupying ratio can be used to guide clinical surgical approach selection to potentially produce better long-term outcomes in patients with OPLL.     

Prevalence and progression of radiographic ossification of the posterior longitudinal ligament and associated factors in the Japanese population: a 3-year follow-up of the ROAD study

Summary

The prevalence of radiographic cervical ossification of the posterior longitudinal ligament (OPLL) in 1,562 Japanese from a population-based cohort was 1.9 %. The presence of OPLL showed a significant association with the femoral neck bone mineral density (BMD), presence of diffuse idiopathic skeletal hyperostosis (DISH) and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects.

Introduction

The purpose of this study was to clarify the prevalence and progression of radiographic OPLL and the associated factors, using the population-based cohort Research on Osteoarthritis/osteoporosis Against Disability (ROAD).

Methods

In the ROAD study, 1,690 participants underwent X-ray examination of the entire spine and both knees. Radiographic OPLL, lumbar spondylosis, knee osteoarthritis and DISH were diagnosed by a single, well-experienced orthopaedic surgeon. An interviewer-administered questionnaire and tests for anthropometric measurements were administered, and the BMDs of the lumbar spine and proximal femur were determined. A new OPLL case was considered if heterotopic ossification in the posterior longitudinal ligament was absent at baseline but present during follow-up. Progression was defined as an increase in the maximum length or width of the ossification at follow-up over that at baseline.

Results

Radiographic OPLL was detected in 30 (17 men, 13 women) of 1,562 individuals who underwent X-ray examination of the cervical spine (prevalence?=?1.9 %). Its prevalence was significantly higher in men than in women (p?=?0.007), but no association with age was observed. In a logistic regression analysis, OPLL showed a significant association with the femoral neck BMD, presence of DISH and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects.

Conclusion

This population-based study clarified the prevalence of radiographic OPLL in the Japanese population as well as its progression. OPLL showed significant association with plasma pentosidine levels, BMD and DISH.     

Prevalence and symptom of ossification of posterior longitudinal ligaments in the Japanese general population

Background

Ossification of the posterior longitudinal ligaments (OPLL) causes myelopathy with progression or trauma. Most OPLL patients visit the hospital after severe symptoms occur, and surgery did not supply complete relief in severe symptoms related to OPLL. While it is necessary to diagnose OPLL early and observe carefully, the nature of symptoms and asymptomatic OPLL have been unclear. The purposes of this study were to investigate the prevalence and symptoms of ossification of the posterior longitudinal ligaments (OPLL) of the cervical spine in the general population.

Methods

The subjects were 1291 Japanese general residents. Radiographic OPLL was detected by lateral view of the cervical spine, and subjects were classified into OPLL and non-OPLL groups. Visual analog scales of neck stiffness, neck pain, arm pain, and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire were examined. Neck and arm symptoms were compared among the presence of OPLL, and among subtypes (continuous, segmental, and mixed types) statistically.

Results

Prevalence of OPLL was 3.7 % in overall participants, 3.9 % in symptomatic participants, and 2.2 % in asymptomatic participants. While 86.7 % of participants with OPLL had symptoms, the consultation rate was only 6.7 %. The female OPLL group had higher neck pain than the non-OPLL group, and neck function of JOACMEQ in the continuous type of OPLL was significantly restricted compared to those without OPLL and with the mixed type of OPLL.

Conclusions

Prevalence of OPLL was 3.7 %, and most of them had neck and arm symptoms; however, they did not visit hospitals. Asymptomatic OPLL had the potential risk for spinal cord injury and myelopathy. Early detection and careful observation would prevent the severe symptoms induced by OPLL.     

New classification system for ossification of the posterior longitudinal ligament using CT images

Background

Ossification of the posterior longitudinal ligament (OPLL) is most frequently seen in the cervical spine. The types of cervical OPLL are classified into continuous, mixed, segmental, and other based on plain lateral X-ray. Computed tomography (CT) imaging is often used in clinical practice for evaluating ossified lesions as it can detect their precise location, size, and shape. However, to date, no CT classification of OPLL lesions has been proposed.

Methods

One hundred and forty-four patients diagnosed with cervical OPLL by plain radiograph were included in this study. Sagittal and axial CT images of the cervical spine were obtained. We propose three classification systems: A, B, and axial. Classification A comprises two lesion types: bridge and nonbridge. Classification B requires examiners to describe all vertebral and intervertebral levels where OPLL exits in the cervical spine. Axial classification comprises central and lateral lesions identified on axial CT images. Seven observers evaluated CT images using this classification system, and intra- and interrater reliability were examined.

Results

Averaged Fleiss’ kappa coefficient of interrater agreement was 0.43 ± 0.26 among the seven observers, averaged intrarater reliability for the existence of OPLL was 72.4 ± 8.8 % [95 % confidence interval (CI) 67.5–76.8]. Fifty-four patients (37.5 %) had the bridge type and 90 the nonbridge type according to Classification A; 102 (70.8 %) had central and 42 (29.2 %) lateral OPLL in the axial classification. Four representative cases defined according to the three classification types are reported here.

Conclusion

Subcommittee members of the Investigation Committee on the Ossification of the Spinal Ligaments of the Japanese Ministry of Public Health and Welfare propose three new classification systems of cervical OPLL based on CT imaging: A, B, and axial.     

Can Microcomputed Tomography Measure Retrieved Polyethylene Wear? Comparing Fixed-bearing and Rotating-platform Knees

Background

Wear of total knee polyethylene has been quantified gravimetrically with thickness measurements and evaluation of surface wear modes. However, these techniques do not localize volumetric wear.

Questions/Purposes

We used micro-CT scans of retrieved total knee liners and unworn, new liners to determine the volume and location of wear.

Methods

We retrieved 12 fixed and 12 rotating-platform bearings after a mean 52 months of use. Inserts were weighed and thickness was measured. Micro-CT scans of retrieved and matched new liners were superimposed to compare the location and magnitude of wear.

Results

The average total wear was 254 ± 248 mm³. The average wear rate was 58 ± 41 mm³/year. Wear was 69% of penetration, demonstrating the contribution of deformation to knee wear. Rotating-platform wear rate was 43 ± 25 mm³/year and the fixed-bearing rate was 74 ± 49 mm³/year. Five percent of the rotating-platform wear rate came from the backside compared with 14% of the fixed-bearing wear rate.

Conclusions

Micro-CT can determine the volume and location of wear of retrieved tibial liners. Because the magnitude of the manufacturing tolerances was approximately half the magnitude of the total wear on average, accounting for the potential influence of tolerances is important to accurately measure volumetric wear if the unworn (preimplantation) geometry of the insert is unknown. Without accounting for tolerances, this technique may not be applicable for retrievals with a short followup that have low wear. However, application of micro-CT could be of value in determining the exact location of wear in knee simulator studies in which the same insert is measured repeatedly and manufacturing tolerances are not a concern.     

Effect of posterior instrumented fusion on three-dimensional volumetric growth of cervical ossification of the posterior longitudinal ligament: a multiple regression analysis

Background Context

Despite the fact that ossification of posterior longitudinal ligament (OPLL) is a three-dimensional disease, conventional studies have focused mainly on a two-dimensional measurement, and it is difficult to accurately determine the volume of OPLL growth and analyze the factors affecting OPLL growth after posterior decompression (laminoplasty or laminectomy and fusion).

A low-radiation exposure protocol for 3D QCT of the spine

Summary

Cadaver and phantom measurements and simulations confirmed that radiation exposure in 3D QCT of the spine can be reduced if 80 kV instead of 120 kV protocols are used; 120 mAs and slice thicknesses of 1–1.3 mm should be usable but obese patient will require higher milliampere-second settings.

Purpose

To develop a low-radiation exposure CT acquisition protocol for 3D QCT of the thoracolumbar spine.

Methods

Twenty-six cadavers were scanned with a standard protocol of 120 kV, 100 mAs and with a low-dose protocol using 90 kV, 150 mAs. The scan range included the vertebrae T6 to L4. Each vertebra was segmented and the integral volume and BMD of the total vertebral body were determined. Effective dose values were estimated. The impact of milliampere-second reduction on image quality was simulated by adding noise.

Results

One hundred ninety-six vertebrae were analyzed. Integral volume as well as integral BMD correlated significantly (p?<?0.001) between standard and low-dose protocols (volume, r ²?=?0.991, residual root mean square (RMS) error, 0.77 cm³; BMD, r ²?=?0.985, RMS error, 4.21 mg/cm³). The slope significantly differed from 1 for integral BMD but not for volume hinting at residual field inhomogeneity differences between the two voltage settings that could be corrected by cross-calibration. Compared to the standard protocol, effective dose was reduced by over 50 % in the low-dose protocol. Adding noise in the 90 kV images to simulate a reduction from 150 to 100 mAs did not affect the results for integral volume or BMD.

Conclusions

For 3D QCT of the spine, depending on scanner type, 80 or 90 kV instead of 120 kV protocols may be considered as an important option to reduce radiation exposure; 120 mAs and slice thicknesses of 1–1.5 mm are usable if segmentation is robust to noise. In obese patients, higher milliampere-second settings will be required.     

Three-Dimensional Metabolic and Radiologic Gathered Evaluation Using VR-RENDER Fusion: A Novel Tool to Enhance Accuracy in the Localization of Parathyroid Adenomas

Background

The aim of this study was to assess the accuracy of a novel imaging modality, three-dimensional (3D) metabolic and radiologic gathered evaluation (MeRGE), for localizing parathyroid adenomas (PAs).

Methods

Consecutive patients presenting with primary hyperparathyroidism who underwent both thin-slice cervical computed tomography (CT) and ^99mTc-sestamibi (MIBI) scanning were included. 3D-CT reconstruction was obtained using VR-RENDER, which was used to perform 3D virtual neck exploration (3D-VNE). The MIBI scan was then fused with the 3D reconstruction to obtain 3D-MeRGE. Sensitivity, specificity, and accuracy were assessed. Parathyroid gland volume and preoperative parathormone (PTH) levels were analyzed as predictive factors of correct localization (i.e., correct quadrant).

Results

A total of 108 cervical quadrants (27 patients) were analyzed. Sensitivities were 79.31, 75.86, 65.51, and 58.61 % with 3D-MeRGE, 3D-VNE, MIBI, and CT, respectively. Specificity was highest with CT (94.93 %) followed by 3D-VNE (92.4 %). MIBI and 3D-MeRGE had the same specificity (88.6 %). 3D-MeRGE and 3D-VNE achieved higher accuracy than MIBI or CT alone. Mean PTH values were significantly higher in patients with lesions that were correctly identified (true positive, TP) than in those whose lesions were missed (false negative, FN) with 3D-VNE (219.60 ± 212.77 vs. 98.75 ± 12.76 pg/ml; p = 0.01) and 3D-MeRGE (217.69 ± 213.76 vs. 09.75 ± 20.48 pg/ml; p = 0.02). The mean parathyroid gland volume difference between TP and FN was statistically significant with all modalities except CT.

Conclusions

3D-MeRGE and 3D-VNE showed high accuracy for localization of PAs. 3D-MeRGE performed better than MIBI or CT alone for detecting small adenomas and those with a low PTH level.     

Significance of segmental instability in cervical ossification of the posterior longitudinal ligament and treated by a posterior hybrid technique

Study design

Retrospective cohort case study.

Objective

To evaluate significance of segmental instability (SI) in cervical ossification of the posterior longitudinal ligament (OPLL) myelopathy and effectiveness of a posterior hybrid technique in the treatment of OPLL associated with SI.

Summary and background data

Some studies suggested both static and dynamic compression factors accounted for the pathogenesis of myelopathy in the OPLL patients.

Method

Between May 2005 and August 2007, 15 patients with multilevel cervical OPLL, diagnosed to be associated with SI, were treated by a posterior hybrid technique including laminoplasty and fusion at instable levels with lateral mass screw fixation. Another 15 cohort patients without SI treated by laminoplasty in the same period were included in the control group. Radiological and clinical data were compared between two groups.

Results

There were no significant differences in Preop. lordotic angle, extent of OPLL, type of OPLL and occupying rate, but more patients tended to present high-intensity zone (HIZ) on MRI in the group with SI. In 15 patients with SI, 17 intervertebral levels had SI, which were distributed at the noncontinuous levels of mixed-type OPLL or the adjacent levels of continuous-type OPLL. They were also consistent with the presence of HIZ levels in the major of patients. After operation, the lordotic angle was maintained well by the posterior hybrid technique in the OPLL with SI group, and was significantly greater than that in the OPLL without SI at the 3- and 4-year follow-up point. Postoperative kyphotic change of the cervical spine and postoperative progression of the ossified lesion were not observed in the OPLL with SI group, but they were respectively observed in four cases (26.7 %) and two cases (13.3 %) in the OPLL without SI group at the 4-year follow-up point. The preoperative C-JOA score in the OPLL with SI group was lower than that in the OPLL without SI group. The average C-JOA score and improvement rate were comparable in the first 2 years after operation between two groups, but there was a decrease in C-JOA score and improvement rate in the following 2 years in the OPLL without SI group. At the 3- and 4-year follow-up points, both postoperative C-JOA score improvement rate in the OPLL with SI group were superior to those in the OPLL without SI group. Each group had one case developing C5 palsy, but three cases in the OPLL without SI group developed late neurological deterioration due to postoperative kyphotic change or progression of the ossified lesion.

Conclusions

Segmental instability, a degenerative dynamic factor, is important to the OPLL myelopathy. The posterior hybrid technique seemed to be effective and safe in the treatment of selective OPLL patients associated with SI. The benefits may include providing stabilization environment for spinal cord recovery, and preventing progressive kyphotic change and progression of OPLL.     

Anterior corpectomy and fusion to C2 for cervical myelopathy: clinical results and complications

Purpose

Anterior cervical corpectomy and fusion (ACCF) to C2 (ACCF-C2) for multilevel lesions is a challenging procedure that is indicated for massive ossification of the posterior longitudinal ligament (OPLL) extending to C2 or stenosis at the upper cervical region accompanied by kyphosis. However, there is little information on the effectiveness of and complications related to ACCF-C2. The purpose of this study was to investigate the overall surgical results and postoperative complications of ACCF-C2 for cervical myelopathy.

Methods

Sixteen patients who underwent ACCF-C2 for OPLL and cervical spondylotic myelopathy were evaluated. An iliac bone or a fibular strut was grafted using a cervical plate. The mean fusion level was 3.8, and the mean follow-up period was 36 months. Patients’ charts, clinical results assessed using the Japanese Orthopedic Association (JOA) scale, and radiographs were retrospectively reviewed.

Results

The average preoperative JOA score was 11.5 ± 3.5, and improved significantly to 13.1 ± 3.2 at 24 months after surgery (P < 0.01). The postoperative cervical alignment was significantly improved at the last follow-up (P < 0.05). Seven patients experienced complications, including neurological complications in three, graft-related complications in three, cerebrospinal fluid leakage in two, late retropharyngeal perforation in one, and dysphasia in one. Three of 16 patients experienced upper airway obstruction in this series, and 2 of 473 patients who underwent anterior cervical decompression and fusion at lower levels in the same period (P < 0.001).

Conclusions

ACCF-C2 is effective for massive OPLL and stenosis accompanied by kyphosis. To avoid complications, skilled decompression and bone grafting technique are necessary, and delayed extubation for upper airway obstruction is preferable.     

Diagnostic value of 18F-FDG PET/CT for lymph node metastasis of esophageal squamous cell carcinoma

Purpose

This study investigated the diagnostic accuracy of hybrid positron-emission tomography/computed tomography (PET/CT) for lymph node (LN) metastasis of esophageal cancer. We also investigated the correlation between the size of metastatic nests and the detection by PET/CT.

Methods

Two hundred and fifty-eight patients with esophageal squamous cell carcinoma who underwent esophagectomy with two- or three-field radical lymphadenectomy were analyzed retrospectively. We compared the diagnosis of preoperative PET/CT to the postoperative histopathological examination by each anatomical field (n = 1,231) in all 258 patients. The metastatic LNs resected from PET/CT positive fields were classified as belonging to the PET/CT-N-positive group (n = 229) and those from negative fields as belonging to the PET/CT-N-negative group (n = 352). The cross-sectional areas of metastatic nests were measured in each metastatic LN.

Results

Of the 1,231 fields, 275 (22 %) were positive for metastasis, including 581 LNs from 408 regional LN stations. The sensitivity and specificity of PET/CT examined by each anatomical field were 25.8 and 97.8 %, respectively. The median area of metastatic nests was 17.7 mm² in the PET/CT-N-positive group, and 7.7 mm² in the PET/CT-N-negative group (p < 0.001).

Conclusions

A significant correlation was suggested between the nest size and detection by PET/CT. Because of its low sensitivity, PET/CT alone is insufficient to determine the surgical procedures, especially when considering reduction surgery.     

Virtual Liver Resection and Volumetric Analysis of the Future Liver Remnant using Open Source Image Processing Software

Background

After extended liver resection, a remnant liver that is too small can lead to postresection liver failure. To reduce this risk, preoperative evaluation of the future liver remnant volume (FLRV) is critical. The open-source OsiriX^® PAC software system can be downloaded for free and used by nonradiologists to calculate liver volume using a stand-alone Apple computer. The purpose of this study was to assess the accuracy of OsiriX^® CT volumetry for predicting liver resection volume and FLVR in patients undergoing partial hepatectomy.

Methods

Preoperative contrast-enhanced liver CT scans of patients who underwent partial hepatectomy were analyzed by three observers. Two surgical trainees measured the total liver volume, resection volume, and tumor volume using OsiriX^®, and a radiologist measured these volumes using CT scanner-linked Aquarius iNtuition^® software. Resection volume was correlated with prospectively determined resection weight, and differences in the measured liver volumes were analyzed. Interobserver variability was assessed using Bland–Altman plots.

Results

25 patients (M/F ratio: 13/12) with a median age of 61 (range, 34–77) years were included. There were significant correlations between the weight and volume of the resected specimens (Pearson’s correlation coefficient: R² = 0.95). There were no major differences in total liver volumes, resection volumes, or tumor volumes for observers 1, 2, and 3. Bland–Altman plots showed a small interobserver variability. The mean time to complete liver volumetry for one patient using OsiriX^® was 19 ± 3 min.

Conclusions

OsiriX^® liver volumetry performed by surgeons is an accurate and time-efficient method for predicting resection volume and FLRV.     

Neurological manifestations of thoracic myelopathy

Introduction

Investigation of preoperative manifestations of thoracic myelopathy in a large population has not been reported. The aim of this study was to identify symptoms specific to anatomical pathology or compressed segments in thoracic myelopathy through investigation of preoperative manifestations.

Materials and methods

Subjects were 205 patients [143 men, 62 women; mean age, 62.2 (range 21–87 years)] with thoracic myelopathy who underwent surgery at our affiliate institutions from 2000 to 2011. The disease distribution included ossification of the ligamentum flavum (OLF) in 106 patients, ossification of the posterior longitudinal ligament (OPLL) in 17, OLF with OPLL in 17, intervertebral disc herniation (IDH) in 23, OLF with IDH in 3, and spondylosis in 39. We assessed (1) initial and preoperative complaints, (2) neurological findings, (3) Japanese Orthopaedic Association scores (JOA, full score, 11 points), (4) the compressed segments, and (5) preoperative duration. Multivariate analyses were performed to examine potential relationships between preoperative manifestations and anatomical pathology or compressed segments.

Results

The multivariate analyses revealed relationships between lower limb muscle weakness and T10/11 anterior compression; lower limb pain and T11/12 anterior compression; low back pain and T11/12 compression; and hyporeflexia in the patellar tendon reflex/foot drop and T12/L1 anterior compression.

Conclusion

This study elucidated symptoms specific to anatomical pathology or compressed segments in thoracic myelopathy. These relationships can be helpful in the initial investigation of thoracic diseases, although additional measures such as MRI or CT are necessary for definitive diagnosis.     

Laparoscopic splenectomy with peginterferon and ribavirin therapy for patients with hepatitis C virus cirrhosis and hypersplenism

Background

This study aimed to evaluate whether laparoscopic splenectomy (Lap-Sp) contributes to the completion and curability of combined peginterferon and ribavirin (peg-IFN + RIB) therapy for cirrhotic patients with pancytopenia due to hypersplenism.

Methods

From December 2004 to September 2007, 21 patients underwent Lap-Sp before treatment with peg-IFN + RIB. All the patients were Child-Pugh class A or B with a mean platelet count of 5.7 × 10⁴/mm³ and a mean leukocyte count of 2,830/mm³. The hepatitis C virus (HCV) genotype was 1b for 18 patients and 2b for 3 patients. Of the 21 patients, 17 had a viral load exceeding 100 KIU/ml, and 4 had a load of less than 100 KIU/ml.

Results

All the patients underwent Lap-Sp without severe complications. The average hospital stay was 12.7 days (range, 6–23 days). Platelet counts increased from a mean of 5.7 ± 2.2 × 10⁴/mm³ preoperatively to 19.6 ± 7.6 × 10⁴/mm³ postoperatively and remained above 7.0 × 10⁴/mm³ during the subsequent peg-IFN + RIB therapy. The full course of therapy was completed for nine patients, with five obtaining a sustained virologic response and one obtaining a biologic response. The five patients who obtained a sustained virologic response had either HCV type 2b or 1b with a low viral load (<100 KIU). At this writing, treatment is ongoing for the remaining 12 patients.

Conclusions

Laparoscopic splenectomy allows patients with HCV cirrhosis and hypersplenism to receive full-dose peg-IFN + RIB therapy. Patients with HCV, genotype 2 or 1b and a low viral load, and hypersplenism may be good candidates for Lap-Sp.     

Passform eines neuen auf Basis einer anatomischen Knochendatenbank entwickelten Klavikula-Osteosyntheseplattensystems (VariAx Clavicle) im Vergleich zu individuell von Chirurgen gebogenen Rekonstruktionsplatten

Background

The aim of this study was the comparison of the plate to bone fit of manually bent reconstruction plates with two industrial prebent clavicle midshaft plates (VariAx Clavicle, Stryker, Duisburg, Germany). The precontoured plates were developed using an anatomical 3D computed tomography (CT)-bone database.

Methods

From an anatomical database of 334 clavicles 8 were randomly chosen and manufactured from artificial bone as physical 3D models using a rapid prototyping system and three surgeons of various qualification levels performed manual bending. The plate to bone fit of the manually bent plates was then compared to the fit of the VariAx midshaft plates.

Results

The industrially manufactured precontoured plates showed a high rate of plate fit with a fit error of less than 1.5 mm² and with a significant difference in comparison to the manually bent plates.

Conclusions

The development of osteosynthesis plates using anatomic 3D databases led to a higher degree of plate fit when compared to manually bent plates even for bones with a variable structure, such as the clavicle.     

Prevalence of renal disease within an urban HIV-infected cohort in northern Italy

Background

Renal disease is an increasingly recognized noninfectious comorbidity associated with human immunodeficiency virus (HIV) infection.

Methods

Our retrospective, cross-sectional study evaluated prevalence of nephropathy among HIV-infected patients followed up in our outpatient clinic during the year 2011. Renal dysfunction and chronic kidney disease (CKD) were defined as estimated glomerular filtration rate (eGFR) <90 ml/min per 1.73 m² and as renal damage or eGFR <60 ml/min per 1.73 m² over a 3-month or greater period, respectively.

Results

We enrolled 894 HIV-infected patients with a mean age of 44.2 years and a mean current CD4 lymphocyte count of 508 cells/mm³. The prevalence of renal dysfunction and CKD was 27.4 and 21.3 %, respectively. Older age, male gender, hypertension, diabetes, proteinuria, hypertriglyceridemia, lower nadir CD4 cell count, current use of tenofovir or tenofovir plus a ritonavir-boosted protease inhibitor were independently associated with renal dysfunction.

Conclusion

Renal dysfunction is a frequent comorbidity among HIV-infected persons and requires a careful clinical and laboratory monitoring of renal function.