Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study

BACKGROUND

Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture.

METHODS

A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out.

OUTCOMES

A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95%CI: 1.07-111.50; P=.007), thrombocytopenia (OR: 27.72; 95%CI: 3.48-221.01; P=.002), history of thromboembolism event (OR: 8.80; 95%CI: 1.31-59.38; P=.026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95%CI: 3.65-125.12; P=.001) and liver disease (OR: 32.04; 95%CI: 2.59-396.29; P=.007).

CONCLUSIONS

Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

[Translated article] Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study

BACKGROUND

Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture.

METHODS

A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out.

OUTCOMES

A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95% CI: 1.07-111.50; P = .007), thrombocytopenia (OR: 27.72;95% CI: 3.48-221.01; P = .002), history of thromboembolism event (OR: 8.80; 95% CI: 1.31-59.38; P = .026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95% CI: 3.65-125.12; P = .001) and liver disease (OR: 32.04; 95% CI: 2.59-396.29; P = .007).

CONCLUSIONS

Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

Neurological complications in critical patients with COVID-19

Introduction

We analysed the neurological complications of patients with severe SARS-CoV-2 infection who required intensive care unit (ICU) admission.

Patients and methods

We conducted a retrospective, observational, descriptive study of consecutive patients admitted to the ICU due to severe respiratory symptoms secondary to SARS-CoV-2 infection between 1 April and 1 June 2020.

Results

We included 30 patients with neurological symptoms; 21 were men (72.40%), and mean age (standard deviation [SD]) was 57.41 years (11.61). The mean duration of ICU stay was 18.83 days (14.33). The neurological conditions recorded were acute confusional syndrome in 28 patients (93.33%), neuromuscular disease in 15 (50%), headache in 5 (16.66%), cerebrovascular disease in 4 (13.33%), and encephalopathies/encephalitis in 4 (13.33%). CSF analysis results were normal in 6 patients (20%). Brain MRI or head CT showed alterations in 20 patients (66.6%). EEG was performed in all patients (100%), with 8 (26.66%) showing abnormal findings. In 5 of the 15 patients with clinical myopathy, diagnosis was confirmed with electroneuromyography. We found a correlation between older age and duration of ICU stay (P = 0.002; 95% CI, 4.032–6.022; OR).

Conclusions

Severe COVID-19 mainly affects men, as observed in other series. Half of our patients presented acute myopathy, and almost all patients left the ICU with acute confusional syndrome, which fully resolved; no correlation was found with EEG or neuroimaging findings. Older age is associated with longer ICU stay.

[Neurological complications in critical patients with COVID-19]

Introduction

We analysed the neurological complications of patients with severe SARS-CoV-2 infection who required intensive care unit (ICU) admission.

Patients and methods

We conducted a retrospective, observational, descriptive study of consecutive patients admitted to the ICU due to severe respiratory symptoms secondary to SARS-CoV-2 infection between 1 April and 1 June 2020.

Results

We included 30 patients with neurological symptoms; 21 were men (72.40%), and mean age (standard deviation [SD]) was 57.41 years (11.61). The mean duration of ICU stay was 18.83 days (14.33). The neurological conditions recorded were acute confusional syndrome in 28 patients (93.33%), neuromuscular disease in 15 (50%), headache in 5 (16.66%), cerebrovascular disease in 4 (13.33%), and encephalopathies/encephalitis in 4 (13.33%). CSF analysis results were normal in 6 patients (20%). Brain MRI or head CT showed alterations in 20 patients (66.6%). EEG was performed in all patients (100%), with 8 (26.66%) showing abnormal findings. In 5 of the 15 patients with clinical myopathy, diagnosis was confirmed with electroneuromyography. We found a correlation between older age and duration of ICU stay (P = .002; 95% CI: 4.032-6.022; OR: 3,594).

Conclusions

Severe COVID-19 mainly affects men, as observed in other series. Half of our patients presented acute myopathy, and almost all patients left the ICU with acute confusional syndrome, which fully resolved; no correlation was found with EEG or neuroimaging findings. Older age is associated with longer ICU stay.

[Non-functioning pituitary adenomas: epidemiology, clinical and postoperative outcome]

INTRODUCTION

Non-functioning pituitary adenomas are the most frequent tumor group in the sellar region. They are usually benign neoplasms diagnosed after visual or hormonal symptoms, although it is not uncommon to detect them as a casual finding.

AIM

To analyze the clinical aspects found in this disease and its response after surgical treatment.

PATIENTS AND METHODS

In a series of 100 cases, epidemiological, clinical, endocrinological, visual and radiological data were analyzed before and after surgical treatment, as well as the complications related to surgery and long-term follow-up.

RESULTS

The most frequent symptom at the time of diagnosis was visual field involvement (62%), and only the 7% of adenomas were a casual finding. The most common hormonal deficit was hypogonadotropic hypogonadism (48%). After surgery, complete recovery of the visual field defect was observed in 54.8% of the patients, only 1% worsening after surgery, and the incidence of diabetes insipidus was 4%. The resection was superior to 95% in 63% of cases, although the percentage of adenomas with invasion of the cavernous sinus in Knosp grades 3 and 4 it was high (45%).

CONCLUSIONS

Although the most frequent symptom of non-functioning pituitary adenomas is campimetric involvement, it has an excellent response to surgery if it is performed within the appropriate time. The grade of invasion of the cavernous sinus is the most limiting factor for a complete surgical resection.

Estimating bradykinesia severity in Parkinson's disease by analysing gait through a waist-worn sensor

Bradykinesia is a cardinal symptom of Parkinson's disease (PD) and describes the slowness of movement revealed in patients. Current PD therapies are based on dopamine replacement, and given that bradykinesia is the symptom that best correlates with the dopaminergic deficiency, the knowledge of its fluctuations may be useful in the diagnosis, treatment and better understanding of the disease progression. This paper evaluates a machine learning method that analyses the signals provided by a triaxial accelerometer placed on the waist of PD patients in order to automatically assess bradykinetic gait unobtrusively. This method employs Support Vector Machines to determine those parts of the signals corresponding to gait. The frequency content of strides is then used to determine bradykinetic walking bouts and to estimate bradykinesia severity based on an epsilon-Support Vector Regression model. The method is validated in 12 PD patients, which leads to two main conclusions. Firstly, the frequency content of the strides allows for the dichotomic detection of bradykinesia with an accuracy higher than 90%. This process requires the use of a patient-dependant threshold that is estimated based on a leave-one-patient-out regression model. Secondly, bradykinesia severity measured through UPDRS scores is approximated by means of a regression model with errors below 10%. Although the method has to be further validated in more patients, results obtained suggest that the presented approach can be successfully used to rate bradykinesia in the daily life of PD patients unobtrusively.

Kaposi sarcoma secondary to endogenous adrenocorticotropic hormone-dependent Cushing syndrome

Kaposi sarcoma (KS) is an angioproliferative tumour that develops as a result of an infection by human herpesvirus 8, which is considered a necessary cause but not sufficient. Other factors - genetic, immunological and environmental - might play a role in the development of the disease. We report a case of KS secondary to endogenous Cushing syndrome (ECS) due to a pituitary adenoma, an association that has been reported only once. We also conducted a search through the Medline and PubMed databases for cases involving KS and ECS, finding only three additional cases that shared common clinical and prognostic features with ours. ECS might favour the development of KS due to immunosuppression. Dermatologists and other clinicians should be aware of this association, as it might be an underdiagnosed condition. It also has an important impact on the management of KS, and based on this review it relies on a good prognosis when ECS is well controlled.

[Solitary fibrous tumors of the meninges: report of three cases and literature review]

We report 3 patients with fibrous solitary tumor of meningeal location where we described the histological study, as well as evolution after the surgical treatment. The described patients presented ages of 37, 52 and 65 years, after the resection has not appeared an objective sign of recurrence in any case after 4, 6 and 7 years of follow-up respectively. Checking the literature the tumor is indistinguishable clinical and radiolocally of the typical meningioma, doing necessary the use of inmunohistochemistry to do the differential diagnosis, where positiveness for CD34 and the negativeness for EMA define the fibrous solitary tumor. It is about a benign tumor, where total removing is the principal factor in prognosis, nevertheless there are cases of local recurrences and long-distance metastasis. We can find all these characteristics in the showed cases of the present article, having the uncertainty of its local or systemic relapse ability in the future.

[Causes of reoperations in patients with lumbar spinal stenosis treated with instrumentations]

OBJECTIVE

In present study we analyze the causes leading to reoperation patients treated for lumbar spinal stenosis with laminectomy and lumbar instrumentation.

MATERIAL AND METHODS

74 patients operated between January of 1996 and December of 2000 with a minimum 4 year follow-up were seleted for the study.

RESULTS

16 patients (21.1%) underwent a new surgical intervention. The main cause for reoperation was stenosis of the adjacent level superiorly to the instrumentation (in 50%). Other causes were radicular fibrosis, persistence of stenosis after the surgery, neuropatic pain, failure of the instrumentation system, transpedicular screws misplacement and break of screws.

CONCLUSIONS

Complications related with the initial surgical procedure are low, as half of the reoperations were due to stenosis of the segment superior to the fixation.

[Intramedullary spinal cord metastasis as the first manifestation of a renal carcinoma]

We present the case of a 69 year-old male without known antecedente who presented a clinical loss of distal force in his lower limbs during the last two months. Magnetic resonance imaging (MRI) showed an intramedullary spinal cord mass at the level of the medullaris cone. The patient was operated on; the histological diagnosis was clear cells carcinoma suggestive of metastasis from an unsuspected renal tumor that was later confirmed with an abdominal CT. When the patient's state is good, surgery can correct the neurological deficit produced by an intramedullary spinal cord lesion. The neurological state of our patient improved after the intervention, and 14 months after surgery, he has no neurological deficit in the lower limbs.

[Spinal epidural abscess caused by Acinetobacter baumannii mimicking a herniated lumbar disc]

INTRODUCTION

A vertebral epidural abscess usually offers a very varied clinical picture of systemic involvement with signs of infection, general malaise and neurological focus. It is diagnosed by means of magnetic resonance imaging, which reveals large lesions with frequent involvement of soft tissues and peripheral contrast enhancement.

CASE REPORT

A 35-year-old male with lumbar-radicular pain in the right S1 with Lasègue's sign at 20 degrees on the right side and abolition of the Achilles' reflex. Magnetic resonance imaging showed an extradural lesion in L5-S1, dependent on the disc space, which suggested a herniated disc. The rest of the anamnesis, explorations and analyses were normal except for a slightly high erythrocyte sedimentation rate. The patient was submitted to surgery and an epidural abscess was observed from which an Acinetobacter baumanii was recovered. Treatment was established with antibiotics and a rigid lumbosacral orthosis. At three months clear signs of discitis were observed in magnetic resonance images; these were completely resolved at eight months, when the patient was asymptomatic.

CONCLUSIONS

Epidural abscess must be included in the differential diagnosis of a herniated disc because in the early phases it can give rise to symptoms of lumbar-radicular pain that are identical to those caused by a herniated lumbar disc. This is the first case of an epidural abscess produced by A. baumanii.

[Anterior approach in low cervical fractures prodited by hyperflexion or tear drop]

Hyperflexion or teardrop fracture of low cervical vertebrae is characterised by ligament affectation of the entire intervertebral segment, the vertebral body, primarily its anteroinferior third and, frequently, spinal medullar affectation. This series presents the clinical symptoms, diagnosis, surgical approach, and post surgical evolution in 30 patients with tear drop fractures. Over the last 30 years, thirty patients with tear drop fractures at the low cervical spine (C3-C7) were admitted to our Neurosurgical Service. Diagnostic studies included simple radiographs, computerised axial tomography (CT), and magnetic resonance imaging (MRI), all of which evidenced the instability of the damaged segment due to osteoligamentous affectation, and a primarily vertebral body fracture. Patients' neurological status was according to the Frankel' scale adapted to the American Spinal Injury Association scale (ASIA). 11 patients were included in grade A, 5 in B, 3 in grade C, 2 in grade D and 9 grade E of neurological affectation. Surgery through an anterior approach was performed, an average of 5 days after placement of halo traction, which had been placed on admission to the hospital. Surgery consisted in vertebral corporectomy and placement of a plate and a graft from the iliac crest. The patients' neurological evolution was favourable in all cases with incomplete medullar lesions. There were 11 patients with complete lesions, or Frankel grade A affectation; two died due to other associated lesions and the other nine showed no neurological improvement after surgery. The degree of arthrodesis was good and only one patient required an a combined anterior-posterior approach. We conclude that teardrop fractures were associated with severe neurological affectation in more than 50% of our patients, and that these fractures provoke instability requiring arthrodesis, generally via an anterior approach.

Cervical epidural hematoma without fracture in a patient with ankylosing spondylitis. A case report

Ankylosing spondylitis (AS) is an inflammatory disease involving the axial spine. Alterations in vertebral biomechanics leave the spine sensitive to traumas which, though minimal, may cause serious neurological lesions, particularly in long term AS patients with a completely ankylosed spine, who are more prone to suffer spine fractures. A 62-year-old man with a long-term AS suffered a minor trauma resulting in a cervical epidural hematoma from C2 to C7, leading to paraplegia. On the diagnosis of hematoma, he underwent C3-C7 left hemilaminectomies, to remove the hematoma. We could find no cause for the hematoma. The patient's condition improved, and he was eventually able to perform all his activities independently. Even though traumatic spinal epidural hematoma (SHE) of the ankylosed spine may occur in the absence of fracture, it is commonly associated with traumatic fracture or dislocation of the spine, particularly the cervical spine. In all the published series of SEH in AS, we could only find one more case of this pathology at the cervical spine without a fracture. Neurologic recovery can be successful if decompression is performed early. SHE must be considered after trauma to an ankylosed spine when there is neurological deterioration despite the absence of fracture. A good outcome depends on the early diagnosis and surgery.

Detection of biological tissue in gels using pulsed digital holography

An out of plane optical sensitive configuration for pulsed digital holography was used to detect biological tissue inside solid organic materials like gels. A loud speaker and a shaker were employed to produce a mechanical wave that propagates through the gel in such a way that it generates vibrational resonant modes and transient events on the gel surface. Gel surface micro displacements were observed between the firing of two laser pulses, both for a steady resonant mode and for different times during the transient event. The biological tissue sample inserted approximately 2 cm inside the gel diffracts the original mechanical wave and changes the resonant mode pattern or the transient wave on the gel surface. This fact is used to quantitatively measure the gel surface micro displacement. Comparison of phase unwrapped patterns, with and without tissue inside the gel, allows the rapid identification of the existence of tissue inside the gel. The results for the resonant and transient conditions show that the method may be reliably used to study, compare and distinguish data from inside homogeneous and in-homogeneous solid organic materials.

Paragangliomas de la cauda equina: a propósito de dos casos

Extraadrenal paragangliomas involving the spinal cord are not common and usually take the compression of the cauda equine. Two cases of paraganglioma of the cauda equina with a different presentation are reported, and the clinical and histopathology findings of this tumor, as well as diagnosis, treatment and prognosis are review. We stress the importance of the high tumor vascularization form of intradural that can make impossible achieve a complete resection. Laminotomy and intraoperatory echography are very useful in the approach to intradural tumors, such as paraganglioma.

Reconstrucción craneal mediante malla de titanio y cemento de apatita carbonatada

We report the case of a 45 year old patient who was affected by an infectious disease of the temporal bone, after the surgical treatment of a meningioma in the greater sphenoid wing. This infection healed after the resection of the craniotomy flap. The remaining bone defect was reconstructed using a titanium mesh covered by hydroxyapatite cement (Norian). The result was excellent due to the strength of the titanium mesh and the volume and contour offered by the hydroxyapatite cement.

[Brain aneurysms: an infrequent cause of transient ischemic stroke]

INTRODUCTION

Ischemic symptomatology related to the presence of saccular brain aneurysms is infrequent, and this makes it difficult to reach a widespread agreement about the most suitable treatment.

CASE REPORT

A 17-year-old male with symptoms of little stroke produced by distal embolisation of an aneurysm in the middle cerebral artery. The patient was treated by endovascular aneurysm exclusion.

CONCLUSIONS

In patients with no other identifiable cause of ischemic attacks, the possible presence of a brain aneurysm must be taken into account. First choice treatment is the obliteration of the aneurysm using endovascular techniques. If the approach to the aneurysm (either endovascular or surgical) entails a high risk for the patient, another possibility is to use antiplatelet drugs.

[A comparative study of the treatment of high grade gliomas]

INTRODUCTION

The influence of surgery, radiotherapy and/or chemotherapy on the outcome on the results in patients with malignant gliomas is controversial.

PATIENTS AND METHODS

We studied 44 patients (26, women; 18 men; age 38 72 years) diagnosed with grades III and IV astrocytoma who had been operated and then received adjuvant radiotherapy and either BCNU or temozolamyde chemotherapy. Survival time and adverse effects of the chemotherapy were analysed.

CONCLUSION

Aggressive surgery associated with radiotherapy and temozolamyde chemotherapy prolonged survival in our patients with malignant astrocytomas.

[Usefulness of tranexamic acid in cranial remodeling surgery]

OBJECTIVES

To assess the usefulness of tranexamic acid (TA) in pediatric cranial remodeling surgery, by analyzing its effects on bleeding and transfusion requirements, number of days of cranial drainage required, and time spent in the postoperative recovery unit.

MATERIAL AND METHOD

A single-blind, controlled study was designed with 20 patients (10 cases and 10 controls) randomly assigned to receive or not receive 15 mg/kg of intravenous TA upon anesthetic induction, every 4 hours during surgery, and every 8 hours throughout the 48 hours after surgery. Variables analyzed were results of blood tests, blood loss, volume transfused, time in the recovery unit, and complications related to TA infusion.

RESULTS

The group treated with TA experienced less bleeding during surgery than did the controls (199 +/- 60 vs 290 +/- 43 mL) and had less need of intraoperative (176 +/- 104 vs 206 +/- 70 mL) and postoperative transfusion (9 +/- 28 vs 52 +/- 72 mL) 24 hours after surgery. TA group patients also spent less time in the recovery unit (60 +/- 14 vs 72 +/- 11 hours). Blood test variables in TA-treated children were also better 24 hours after surgery with regard to hemoglobin (12.1 +/- 2 vs 11.6 +/- 1.3 mg/dL) and platelet (261 +/- 68.5 vs 181.6 +/- 58.1 platelets/mm3) concentrations, and cephalin time (33 +/- 12 vs 49 +/- 16 seconds). No complications related to TA treatment were observed.

CONCLUSIONS

TA can reduce perioperative bleeding in the context of pediatric cranial remodeling surgery. TA-treated patients have less need of transfusion and this may reduce the rate of related complications as well a make care more efficient.

[Update in neurocysticercosis treatment]

INTRODUCTION

Neurocysticercosis is the most frequent central nervous system parasitosis, although quite infrequent in our country. Its rising incidence can be explained by immigration from regions of the world where this disease is endemic.

OBJECTIVE

This paper reviews treatment options for this condition. PATIENTS AND METHODS. Eight patients have been diagnosed with neurocysticercosis in the last three years in our hospital. Patient age, sex, origin, symptoms, CT and MR images, diagnostic tests, treatment and duration of medical treatment and clinical and neuroradiological evolution are examined.

RESULTS

Patient age ranged from 25 to 33 years, all eight came from South America and the most frequent initial symptom was an epileptic crisis. Two patients had a single lesion, six had multiple lesions and all eight showed the lesion in the parenchyma. Only 50% showed a positive serum ELISA test for Taenia solium. Initial treatment was surgical in only one patient and the other seven received albendazol. In one of the latter the drug was ineffective and surgery was undertaken. A ten month follow up period has found a favorable evolution in all the patients, who are all also asymptomatic at the present time.

DISCUSSION AND CONCLUSIONS

Neurocysticercosis is more common among immigrants than the local population in Spain. The initial treatment should be medical, with surgery as an option for non responders. We believe that duration of the medical treatment will depend on the patient and the clinico radiological evolution of his/her disease.

[Management of multiple cerebral cavernomatosis]

INTRODUCTION

Cavernous angiomas are angiographically occult vascular malformations that are present in 0.4% of people, and represent 5 13% of all cerebrovascular malformations. They can be alone or multiple, and sporadic or familial. The presence of multiple lesions is more frequent in familial cavernomatosis.

OBJECTIVES

Improve our knowledge of the natural history of multiple cavernomatosis in order to improve our diagnostic and therapeutic management of this entity.

PATIENTS AND METHODS

We have retrospectively reviewed 18 cases of multiple cerebral cavernomatosis; 4 of them belonged to the same family and 2 belonged to another family. Number, size, characteristics and evolution of the lesions, symptoms, treatment and clinical outcome have been analysed during a follow up period longer than 5 years.

RESULTS

31.5% of the cavernous angiomas reviewed by our department were multiple (at least three lesions). During the 5 year follow up period only four (4/18) patients underwent surgical treatment. 50% of patients suffered at least one hemorrhagic event with clinical impairment, and the most frequent manifestations were headache, focal deficit and seizures. The hemorrhagic rate per lesion per year was under 1%, for the more than 200 lesions and the low frequency of hemorrhagic events with clinical impairment in the time.

CONCLUSIONS

Surgical treatment must be considered in patients with accessible lesions that have produced symptoms several or progressive symptoms. The non surgical patients should be followed with yearly MRI. When more than one first degree relative has a cavernous malformation or familial antecedent with cerebral hemorrhage or epilepsy, serial follow up monitoring consisting of physical examinations and MRI should be suggested to family members.

Pulsed digital holographic interferometry for dynamic measurement of rotating objects with an optical derotator

A method for measuring dynamic deformations of rotating objects with pulsed digital holography is described. An optical derotator is used to compensate for the rotation. A CCD camera is used to record two holograms with a short time separation (20 mus). Results of deformations between the recordings are obtained after subtraction of the phase distribution between the two digital holograms. Fringe phase maps of the phase subtraction of two holograms compensated by the derotator and recorded with a Q-switched double-pulsed ruby laser are presented. A flat disk and the blades of a fan were investigated. We used an optical arrangement that allowed us to improve laser illumination and energy efficiency. Experimental results on quantitative evaluation of dynamical out-of-plane deformations are presented.

[Efficacy of arthrodesis in the posterior approach of cervical myelopathy: comparative study of a series of 36 cases]

OBJECTIVE

The effectiveness of arthrodesis associated to laminectomy as a treatment for cervical myelopathy has been retrospectively evaluated analysing the clinical evolution of 36 patients as well as the change in cervical column saggittal curvature comparing a group of patients with a simple laminectomy to another in whom laminectomy was accompanied by posterior arthrodesis.

MATERIAL AND METHODS

36 posterior approaches were performed to treat patients diagnosed of spondyloartrosic myelopathy between 1992 and 1999; 19 cases were treated with a simple laminectomy and other 17 also underwent arthrodesis with posterior instrumentation. The clinical evolution (using grades 0-5 on the Nurick scale) and cervical curvature have been evaluated for an average time interval of 40 months.

RESULTS

Patients treated with laminectomy plus arthrodesis showed an average 1.24 point improvement on the Nurick scale in comparison to the 0.84 point improvement observed in patients treated with laminectomy alone. The cervical curvature attained a more physiological angulation in 53% of the patients with an arthrodesis and in 29% of the patients with simple laminectomy; curvature worsened in 7% of the patients with arthrodesis and in 24 degrees/a of those with laminectomy alone.

CONCLUSION

Cervical myelopathy cases requiring a posterior approach for laminectomy obtain a better clinical evolution when an arthrodesis with posterior instrumentation is associated with the laminectomy. These patients also present improved cervical curvature as compared to the group without instrumentation.

Inflammatory pseudotumor of the median nerve. Case report and review of the literature

The authors report the presence of an inflammatory pseudotumor of the median nerve in a young woman who presented with a sensorimotor deficit in the median nerve area. Magnetic resonance (MR) images revealed a fusiform mass in the nerve, and the patient underwent surgery for a suspected peripheral nerve-sheath tumor. Her clinical condition improved slowly and notably. Histological study revealed a heterogeneous lymphoid infiltration with mononuclear cells, lymphocytes (mostly T cells), and plasmocytoid cells. Because of the unknown significance of this infiltration, the patient was examined to exclude the possible diagnosis of a systemic tumoral process. All the studies yielded negative results and no systemic disease was found. Later, control MR imaging revealed no tumoral remains, and electromyography demonstrated progressive improvement of median nerve function. The follow-up period has been 8 years. The cause of the lesion is unknown. The differential diagnosis includes benign and malignant peripheral nerve-sheath tumors, lymphoma, and all tumorlike lesions of peripheral nerves.

Transient deformation measurement with electronic speckle pattern interferometry by use of a holographic optical element for spatial phase stepping

We have used a computer-generated holographic optical element (HOE) with electronic speckle pattern interferometry to calculate the interference phase corresponding to the deformation of a test object from a single TV frame. The HOE is a modified crossed phase grating that introduces a known phase change between the +/-1 diffracted orders, without being translated. The progressive propagation of transient mechanical waves was measured with an rms precision of 2pi/30.

Transient deformation analysis by a carrier method of pulsed electronic speckle-shearing pattern interferometry

The introduction of a pulsed laser into an electronic speckle-shearing pattern interferometer allows high-speed transient deformations to be measured. We report on a computerized system that permits automatic data reduction by introducing carrier fringes through the translation of a diverging lens. The quantitative determination of the phase map that is due to deformation is carried out by the spatial synchronous detection method. Experimental results obtained for a metal plate transiently deformed by an electromagnetic hammer illustrate the advantages of the proposed system.

Study of transient deformations with pulsed TV holography: application to crack detection

We report the measurement of reproducible transient deformations with single-pulsed-subtraction and double-pulsed-addition TV holography with both in-plane and out-of-plane optical configurations. An original synchronization system (controlling mechanical excitation of the object, firing the laser pulses, and image acquisition) used to obtain the subtraction and the addition correlation fringes is described. Experimental results are presented for the propagation of mechanical shock waves in a cantilever specimen and their subsequent diffraction by a crack in the specimen. These preliminary results show that the technique may be used for crack detection.