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Nicolas Theumann

Publications and source records attributed to Nicolas Theumann.

16 recordsLinked to original sources
PubMed2006

[Indications to complementary radiological exams for pathologies of the shoulder].

Plain Xrays should stay in pole position for the evaluation of shoulder's pathologies. They allow frequently to make a diagnosis of the lesion. Indications to complementary exams are well established. CT-scan and MRI have to give responses to precise questions, which then will permit to manage the treatment. CT-scan allows to evaluate accurately bone structures. It is very useful for analysing complex fractures of the proximal humerus. It allows also to evaluate the amount of glenoid wear to correct before implanting a prosthesis. Arthro-MRI is used to study soft tissues, cartilage and bone. Therefore, it is the first choice exam to evaluate the rotator cuff tendons, as well as the labrum and ligaments in case of shoulder instability.

Humans↗
PubMed2006

Inserting pedicle screws in the upper thoracic spine without the use of fluoroscopy or image guidance. Is it safe?

Several studies have looked at accuracy of thoracic pedicle screw placement using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1-T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of upper thoracic screw placement without the use of fluoroscopy or image guidance, and report on implant related complications. A single surgeon inserted 60 screws in 13 consecutive non-scoliotic spine patients. These were the first 60 screws placed in the high thoracic spine in our institution. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post-operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Implant related complications were prospectively noted. No pedicle screw misplacement was found in 61.5% of the patients. In the remaining 38.5% of patients some misplacements were noted. Fifty-three screws out of the total 60 implanted were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and two lateral violations were noted in the seven misplaced screws. One of the seven misplaced screws was considered to be questionable in terms of pedicle perforation. No implant related complications were noted. We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies using image-guided navigation at the thoracic level.

Adolescent↗
PubMed2006

A new, easy, fast, and safe method for CT-guided sacroplasty.

Sacral insufficiency fractures constitute clinical challenges because no effective surgical techniques can be applied and only a conservative treatment is currently performed. Sacroplasty is increasingly used to treat sacral insufficiency fractures. A computed tomography (CT)-guided technique concerning the placement of the sacroplasty needles within the sacral wings by using a laser alignment light guidance associated with a CT gantry tilt in a plane parallel to the sacral bone is presented. This method allowed a fast and precise placement of the needle in and along the sacral wings, thus preventing the use of multiple needles to reach the fracture sites.

Aged↗
PubMed2006

Observer reliability in evaluating pedicle screw placement using computed tomography.

Pedicle screw insertion in spinal surgery is a demanding technique with potential risks to neurological structures, for example, within the spinal canal. Assessing screw placement in clinical practice has been performed using plain radiographs and/or mainly axial computed tomography (CT) images. Screw placement using CT image reconstructions in multiple planes has been described, but its reliability has yet to be studied. This study aimed at addressing the clinical issue of interobserver and intraobserver reliability in the use of axial and coronal CT images for the assessment of pedicle screw placement. Fifty nine pedicle screws were studied by two experienced radiologists on two separate occasions. Screw placement was classified as "in", "out" or "questionable". On average, 88% and 92% of the screws were classified as "in" by the first and second radiologist, respectively. Intraobserver agreement strength was almost perfect for both observers using either axial or coronal images. Interobserver agreement strength was almost perfect (axial) and substantial (coronal) in the first reading and substantial (axial, coronal) in the second reading. Assessing screw placement in more than one CT imaging plane is not only useful but reliable. Routine use may enhance reporting quality of screw placement by surgeons and radiologists.

Adult↗
PubMed2006

Computer tomography assessment of pedicle screw insertion in percutaneous posterior transpedicular stabilization.

Percutaneous insertion of cannulated pedicle screws has been recently developed as a minimally invasive alternative to the open technique during instrumented fusion procedures. Given the reported rate of screw misplacement using open techniques (up to 40%), we considered it important to analyze possible side effects of this new technique. Placement of 60 pedicle screws in 15 consecutive patients undergoing lumbar or lumbosacral fusion, mainly for spondylolisthesis, were analyzed. Axial, coronal, and sagittal reformatted computer tomography images were examined by three observers. Individual and consensus interpretation was obtained for each screw position. Along with frank penetration, we also looked at cortical encroachment of the pedicular wall by the screw. Thirteen percent of the patients (2/15) had severe frank penetration from the screws, while 80% of them (12/15) had some perforation. On axial images the incidence of severe frank pedicle penetration was 3.3% while the overall rate of screw perforation was 23%. In coronal images the overall screw perforation rate rose to 30% while the rate of severe frank pedicle penetration remained unchanged. One patient (6.6%) suffered S1 root symptoms due to a frankly medially misplaced screw, requiring re-operation. This study has shown that percutaneous insertion of cannulated pedicle screws in the lumbar spine is an acceptable procedure. The overall rate of perforation in axial images is below the higher rates reported in the literature but does remain important. Frank penetration of the pedicle was nevertheless low. It remains a demanding technique and has to be performed with extreme care to detail.

Bone Screws↗
PubMed2006

Impact of the introduction of 16-row MDCT on image quality and patient dose: Phantom study and multi-centre survey.

The purpose was to compare the image quality and patient dose between 4- and 16-row MDCT units and to evaluate the dispersion of the dose delivered for common clinical examinations. Four 4- and 16-row MDCT units were used in the study. Image noise levels from images of a CatPhan phantom were compared for all units using a given CTDI(vol) of 15.0+/-1.0 mGy. Standard acquisition protocols from ten centres, shifted from 4- to 16-row MDCT (plus one additional centre for 16-row MDCT), were compared for cerebral angiography and standard chest and abdomen examinations. In addition, the protocols used with 16-row MDCT units for diagnosis of the unstable shoulder and for cardiac examinations were also compared. The introduction of 16-MSCT units did not reduce the performance of the detectors. Concerning the acquisition protocols, a wide range in practice was observed for standard examinations; DLP varied from 800 to 5,120 mGy x cm, 130 to 860 mGy x cm, 410 to 1,790 mGy x cm and 850 to 2,500 mGy x cm for cerebral angiography, standard chest, standard abdomen and heart examinations, respectively. The introduction of 16-row MDCT did not, on average, increase the patient dose for standard chest and abdominal examinations. However, a significant dose increase has been observed for cerebral angiography. There is a wide dispersion in the doses delivered, especially for cardiac imaging.

Cerebral Angiography↗
PubMed2006

Posttraumatic coccygeal instability.

PURPOSE: To report the middle term results of partial coccygectomy in a consecutive series of 15 patients with chronic coccygodynia. METHODS: Fifteen patients with chronic coccygodynia were referred to our outpatient clinics. The patients were investigated with dynamic lateral radiography and magnetic resonance imaging (MRI). We diagnosed a posttraumatic coccygodynia with instability of the coccygeal segment and performed a partial coccygectomy after failure of the conservative treatment. RESULTS: All patients underwent subjective and objective assessment after a mean time of 2.8 years from surgery. There were 11 excellent, 3 good, and 1 fair results. The mean time of improvement was 15 weeks, and no further improvement was observed after 6 months. CONCLUSION: Partial coccygectomy is a good therapeutic option for posttraumatic coccygodynia. Dynamic radiography is a useful tool to differentiate posttraumatic from idiopathic coccygodynia. MRI may be useful for further evaluation of the patients after inconclusive dynamic radiography.

Adult↗
PubMed2005

An unusual natural history of a L5-S1 spondylolisthesis presenting with a sacral insufficiency fracture.

Sacral insufficiency fractures have been described in association with conditions leading to osteoporosis. No association with spondylolisthesis has been described to date. A 60-year-old patient with known lumbosacral isthmic spondylolisthesis presented with exacerbation of symptoms initially thought to be linked to her known spinal pathology. Plain radiography, computer tomography, MRI and bone scan confirmed the presence of a recent sacral insufficiency fracture with anterior angulation. Conservative treatment resulted in improvement of symptoms after 6 months. Care should be taken when considering older patients for more aggressive treatment if they present with exacerbation of back pain and sciatica in the presence of a pre-existing spondylolisthesis. A suspicion of insufficiency fracture should be raised if risk factors exist and further investigations ordered in particular if plain radiography is normal. Lumbosacral fusion might be inappropriate in this setting.

Female↗
PubMed2005

Arthroscopic treatment of anterior shoulder instability using knotless suture anchors.

PURPOSE: In this study, we evaluated the results of arthroscopic stabilization of the shoulder using knotless anchors and the lesions associated with anterior-inferior labrum avulsion. TYPE OF STUDY: Retrospective clinical study. METHODS: Twenty consecutive patients affected with anterior unidirectional post-traumatic shoulder instability were treated with arthroscopic reconstruction using knotless anchors. During the surgical procedure, associated lesions such as superior labrum anterior posterior (SLAP) (15%) and rotator interval (15%) were repaired. The patients were evaluated at a mean follow-up of 43 months. RESULTS: Eighty percent of patients resumed sports activity without any limitation and 90% of patients were satisfied with the results of surgery. One patient (5%) had a recurrent dislocation; this patient resumed a contact sport activity despite medical advice. One patient (5%) related signs of shoulder insecurity at the extreme degree of abduction and external rotation; this patient had resumed sports activity with a moderate limitation and was the only patient who was not completely satisfied with the results of surgery. No significant difference was observed between the operated and the contralateral shoulder according to the Rowe and Constant scores. The mean loss of external rotation was 3 degrees . We did not have any cases of anchor loosening, nor did we find signs of shoulder degenerative osteoarthritis on the radiographs. CONCLUSIONS: The knotless anchor seems to be a viable alternative for arthroscopic labrum repair, allowing a good capsular shift. Arthroscopic management of shoulder instability allows us to diagnose and treat associated lesions, thus improving the success rate of this type of surgery. LEVEL OF EVIDENCE: Level IV, case series.

Accidents↗
PubMed2005

Leg pain due to bilateral focal recurrent myositis in a hemodialysis patient.

Leg pain is a common symptom in dialysis patients. In most cases, the cause is easily identified, but some rare causes have been recognized. We describe a case of focal myositis as the source of recurrent leg pain in a hemodialysis patient. This disease usually is self-limited and has a spontaneously favorable outcome. We review the differential diagnosis of leg pain in this patient population.

Female↗
PubMed2004

[Prevention of heterotopic ossification following prosthetic total hip replacement].

Heterotopic ossification, mostly of the hip, is a frequent complication after reconstructive surgery. Most common prophylactic therapies are non-steroidal anti-inflammatory medication (AINS) applied post-operatively and external radiotherapy (RT) administered in the pre- or post-operative setting. Both treatments proved to be efficient in several randomised clinical trials. Prevailing trend regarding RT is a treatment prior to surgery. It is appreciated by both physician and the patient because it is simple and comfortable. In this article, we present the literature linked to the subject together with the benefit and the inconvenience of both therapeutic methods.

Arthroplasty, Replacement, Hip↗
PubMed2004

[Biopsy and surgical treatment of soft tissue tumors].

When a soft tissue tumor is initially misdiagnosed as a simple trauma or a mass, treatment may be adversely affected by the delay in diagnosis or an inappropriate invasive procedure that results in extension of a probable malignant tumor. Patients with soft tissue tumors present a diagnostic challenge to the clinician. A systematic approach to the evaluation and biopsy is necessary in order to minimize diagnostic errors and biopsy complications. With a multidisciplinary approach and adequate surgical management, the prognosis with a five-year survival rate can be excellent.

Biopsy↗
PubMed2004

[The role of diagnostic imaging in sarcoma].

A radiologist should be included in the multidisciplinary approach which will allow optimal diagnostic evaluation and treatment of sarcoma. The appropriate use of ultrasound, computed tomography and magnetic resonance imaging plays a significant role in the evaluation of these tumors and their recurrences. The potential role of dynamic magnetic resonance imaging has also been evaluated. A review of diagnostic imaging and their clinical utility is discussed.

Bone Neoplasms↗
PubMed2003

Thoracolumbar spine fractures in patients who have sustained severe trauma: depiction with multi-detector row CT.

PURPOSE: To determine if multi-detector row computed tomography (CT) can replace conventional radiography and be performed alone in severe trauma patients for the depiction of thoracolumbar spine fractures. MATERIALS AND METHODS: One hundred consecutive severe trauma patients who underwent conventional radiography of the thoracolumbar spine as well as thoracoabdominal multi-detector row CT were prospectively identified. Conventional radiographs were reviewed independently by three radiologists and two orthopedic surgeons; CT images were reviewed by three radiologists. Reviewers were blinded both to one another's reviews and to the results of initial evaluation. Presence, location, and stability of fractures, as well as quality of reviewed images, were assessed. Statistical analysis was performed to determine sensitivity and interobserver agreement for each procedure, with results of clinical and radiologic follow-up as the standard of reference. The time to perform each examination and the radiation dose involved were evaluated. A resource cost analysis was performed. RESULTS: Sixty-seven fractured vertebrae were diagnosed in 26 patients. Twelve patients had unstable spine fractures. Mean sensitivity and interobserver agreement, respectively, for detection of unstable fractures were 97.2% and 0.951 for multi-detector row CT and 33.3% and 0.368 for conventional radiography. The median times to perform a conventional radiographic and a multi-detector row CT examination, respectively, were 33 and 40 minutes. Effective radiation doses at conventional radiography of the spine and thoracoabdominal multi-detector row CT, respectively, were 6.36 mSv and 19.42 mSv. Multi-detector row CT enabled identification of 146 associated traumatic lesions. The costs of conventional radiography and multi-detector row CT, respectively, were 145 and 880 US dollars per patient. CONCLUSION: Multi-detector row CT is a better examination for depicting spine fractures than conventional radiography. It can replace conventional radiography and be performed alone in patients who have sustained severe trauma.

Adult↗
PubMedDate not supplied

Multimodality imaging evaluation of the pediatric neck: techniques and spectrum of findings.

Neck masses are a common finding in children and can present a difficult diagnostic challenge. These masses may represent a variety of conditions having a congenital, acquired inflammatory, neoplastic, or vascular origin. The fascial spaces and compartments of the neck provide an approach to differential diagnosis, and extensive knowledge of the anatomy and contents of each cervical compartment is mandatory in the diagnosis of pediatric neck lesions. Several imaging techniques, including radiography, gray-scale and Doppler ultrasonography, conventional and three-dimensional computed tomography, magnetic resonance (MR) imaging, and MR angiography, have been proposed for the evaluation of such lesions, and each has its own advantages and limitations. The imaging findings in 120 children who had been referred or treated for cervical lesions were retrospectively reviewed, and a systematic multimodality imaging approach to pediatric neck lesions based on the involvement of anatomic compartments of the cervical region was developed to increase diagnostic efficiency. Careful attention to clinical history and physical examination findings, along with knowledge of the embryologic features and anatomy of the cervical region and a multimodality imaging approach, is very helpful in the diagnosis and management of pediatric neck lesions.

Adolescent↗