Histological characterization and biochemical analysis of paraspinal muscles in neuromuscularly healthy subjects.

INTRODUCTION: There are no generally accepted histopathological reference values in paraspinal skeletal muscle biopsies. METHODS: We examined multifidii muscle biopsies from 20 neuromuscularly healthy subjects using routine histological stains and biochemical analyses of respiratory chain enzymes. RESULTS: Staining showed incomplete myopathic features, such as increased variability in fiber size, type 1 hypertrophy, rounded fiber shape, endomysial fibrosis, and replacement by adipose tissue. Acid phosphatase reaction was positive in up to 35% of the selected muscle fibers. Mitochondrial changes were obvious but revealed no selective age dependence. Reduced complex I, cytochrome c oxidase (COX), and citrate synthase (CS) could be observed. CONCLUSIONS: Because the increased variability in morphological details can easily be misinterpreted as myopathic changes, analysis of paraspinal muscles should take into consideration that incomplete myopathic features and reduced oxidative enzyme activities for complex I, COX, and CS are normal variations at this location.

Predictive value of preoperative clinical examination for subacromial decompression in impingement syndrome.

PURPOSE: Subacromial decompression is the standard surgical treatment of subacromial impingement syndrome. Unsatisfactory results have been reported for concomitant lesions as well as inadequate diagnosis. We sought to determine the predictive value of the preoperative examination for the results of arthroscopic subacromial decompression in impingement syndrome. METHODS: Forty-nine shoulder joints in 47 patients receiving arthroscopic subacromial decompression were prospectively followed for a mean 3.7 ± 0.4 years. Prior to surgery, the impingement tests according to Neer, Hawkins-Kennedy (in the neutral as well as abducted position), and the Jobe test (empty can position) were evaluated as well as the presence of a painful arc. The association between the presence of these sings, success of the operation, and improvement in Constant scores as well as WORC indices was analysed. RESULTS: Pre- to postoperative improvement in Constant scores as well as WORC indices was greater in case of a positive test result for every test studied. With the numbers available, significant greater improvements in Constant scores were observed only for patients with a positive Hawkins-Kennedy sign in the neutral position, Neer and Jobe tests, compared to patients with negative signs, respectively. No significant differences were observed for the improvement in WORC indices. Patients with at least four positive tests out of the five studied had greater improvement in Constant scores than patients with three or less positive test results. Five patients went on to receive subsequent shoulder surgery. There was no association between the necessity for revision surgery and the presence or absence of impingement signs. CONCLUSION: The impingement tests according to Hawkins-Kennedy, Neer, and Jobe are valid predictors of outcome after subacromial decompression, as is the presence of multiple impingement tests. This study may aid in improving patient outcome and especially patient selection for subacromial decompression. LEVEL OF EVIDENCE: Prognostic, Level I.

Circumferential dynamic stabilization of the lumbar spine: a biomechanical analysis.

PURPOSE: To assess segmental angulation and mobility following implantation of the Charité artificial disc in combination with the posterior dynamic fixation device dynamic stabilization system (DSS) and the interspinous spacer Coflex at the L4-L5 segment, respectively. METHODS: Six human L4-L5 specimens were loaded with pure moments of ±7.5 Nm in flexion/extension, lateral bending, and axial rotation in a custom-made spine tester. The testing protocol was as follows: (a) intact condition, (b) destabilization by resection of the anterior longitudinal ligament (ALL), (c) implantation of the Charité with retained posterior longitudinal ligament (PLL), (d) supplemental DSS implantation, (e) removal of DSS rods and PLL resection, (f) DSS rod re-implantation, (g) enlargement of rod length, and (h) removal of DSS and implantation of Coflex. Range of motion (ROM), neutral zone, and segmental angulation were determined. RESULTS: ALL resection did not influence significantly ROM. TDR increased lateral bending and axial rotation only after resection of the PLL, whereas flexion/extension remained unchanged. DSS limited all degrees of freedom prior to and after PLL resection. Rod length enlargement had no significant effect. Coflex limited significantly flexion/extension compared to the intact state and TDR, whereas lateral bending and axial rotation remained unchanged. TDR increased lordosis, whereas Coflex had a substantial kyphosing effect. CONCLUSIONS: This study demonstrates that posterior dynamic stabilization in combination with TDR reduces flexion/extension ROM and segmental lordosis in a monosegmental biomechanical model.

Reliability of radiologic glenohumeral osteoarthritis classifications.

BACKGROUND: This study was conducted to determine the intraobserver and interobserver reliability of glenohumeral osteoarthritis classification schemes. MATERIALS AND METHODS: The plain radiographs of 108 shoulder joints from 96 consecutive patients with glenohumeral osteoarthritis treated at our institution were graded into 6 classification systems by 2 observers on 2 occasions. The intraobserver and interobserver reliability of the classification schemes were determined by using Cohen's κ coefficient and weighted according to Landis and Koch. RESULTS: The intraobserver and interobserver reliabilities were 0.907 (observer 1), 0.965 (observer 2), and 0.851 (interobserver) for the Samilson-Prieto grading system; 0.954, 0.948, and 0.869 for the Allain modification; 0.936, 0.830, and 0.791 for the Gerber modification; 0.887, 0.892, and 0.744 for the Kellgren and Lawrence classification; 0.873, 0.964, and 0.935 for the Weinstein; and 0.854, 0.934, and 0.797 for the Guyette grading system. CONCLUSION: The classification systems according to Weinstein and Guyette and the modifications of the Samilson-Prieto classification according to Allain and Gerber showed a comparable reliability with the commonly used glenohumeral osteoarthritis grading systems according to Samilson-Prieto and Kellgren-Lawrence. Thus, they are recommended for clinical and especially scientific purposes.

The role of prosthesis design on segmental biomechanics: semi-constrained versus unconstrained prostheses and anterior versus posterior centre of rotation.

The purpose of this study was to evaluate the influence of different implant designs of total lumbar disc replacements on the segmental biomechanics of the lumbar spine. The unconstrained Charité, the semi-constrained Prodisc and a semi-constrained Prototype with more posterior centre of rotation than the Prodisc were tested in vitro using six human, lumbar spines L2-L5. The segmental lordosis was measured on plain radiographs and the range of motion (ROM) for all six degrees of freedom with a previously described spine tester. All prostheses were implanted at level L3-L4. Compared with the intact status all prostheses resulted in a significant increase of segmental lordosis (intact 5.1°; Charité 10.6°, p = 0.028; Prodisc 9.5°, p = 0.027; Prototype 8.9°, p = 0.028), significant increase of flexion/extension (intact 6.4°, Charité 11.3°, Prodisc 12.2°, Prototype 12.2°) and axial rotation (intact 1.3°, Charité 5.4°, Prodisc 3.9°, Prototype 4.2°). Lateral bending increased significantly only for the Charité (intact 7.7°; Charité 11.6°, p = 0.028; Prodisc 9.6°, Prototype 9.8°). The segmental lordosis after Prototype implantation was significantly lower compared with Charité (p = 0.024) and Prodisc (p = 0.044). No significant difference could be observed for segmental lordosis between Charité and Prodisc and for ROM between the two semi-constrained prosthesis Prodisc and Prototype. The axial rotation for the unconstrained Charité was significantly higher than for the semi-constrained prosthesis Prodisc and Prototype, flexion/extension and lateral bending did not differ. Summarizing, the unconstrained prosthesis design increased segmental lordosis and showed a tendency towards higher ROM for axial rotation/lateral bending and lower ROM for flexion/extension than a semi-constrained prosthesis. A more anterior centre of rotation in a semi-constrained prosthesis resulted in a higher increase of segmental lordosis after TDR than a semi-constrained prosthesis with more posterior centre of rotation. The location of the centre of rotation in a semi-constrained prosthesis did not alter the magnitude of ROM. Despite the different alterations of ROM and segmental lordosis due to implant design, these differences were negligible compared with the overall increase of ROM and segmental lordosis by the implantation of a TDR compared with the physiologic state.

Resect or not to resect: the role of posterior longitudinal ligament in lumbar total disc replacement.

With regard to the literature, several factors are considered to have an impact on postoperative mobility after lumbar total disc replacement (TDR). As TDR results in a distraction of the ligamentous structures, theoretically the postoperatively disc height and ligamentous integrity have also an influence on biomechanics of a treated segment. The purpose of the study was to evaluate the influence of posterior longitudinal ligament (PLL) resection and segmental distraction on range of motion (ROM). Six human, lumbar spines (L2-L3) were tested with pure moments of ±7.5 Nm in a spine loading apparatus. The ROM was determined in all three motion planes. Testing sequences included: (1) intact state, (2) 10 mm prosthesis (PLL intact), (3) 10 mm prosthesis (PLL resected), (4) 12 mm prosthesis (PLL resected). The prosthesis used was a prototype with a constrained design using the ball-and-socket principle. The implantation of the 10 mm prosthesis already increased the disc height significantly (intact: 9.9 mm; 10 mm prosthesis: 10.6 mm; 12 mm prosthesis: 12.7 mm). Compared to the intact status, the implantation of the 10 mm prosthesis resulted in an increase of ROM for flexion/extension (8.6° vs 10.8°; P = 0.245) and axial rotation (2.9° vs 4.5°; P = 0.028), whereas lateral bending decreased (9.0° vs 7.6°; P = 0.445). The resection of the PLL for the 10 mm prosthesis resulted in an increase of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 11.4°, P = 0.046; axial rotation: 5.1°, P = 0.046; lateral bending: 8.6°, P = 0.028). The subsequent implantation of a 12 mm prosthesis, with resected PLL, resulted in a significant decrease of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 8.4°, P = 0.028; axial rotation: 3.3°, P = 0.028; lateral bending: 5.1°, P = 0.028). Compared to the intact status, the 12 mm prosthesis with resected PLL only decreased lateral bending significantly while the 10 mm prosthesis with intact PLL increased axial rotation significantly. The resection of the PLL during TDR results in a significant increase of ROM in all three principle motion planes. But it still remains unclear if this increase which is in median not more than 1° may alter the clinical results. Moreover, the destabilizing effect of PLL resection can be reversed using a higher implant. The prosthesis height seems more crucial than PLL preservation to maintain the primary stability after TDR.

Reliability of radiologic classification for cuff tear arthropathy.

BACKGROUND: Several classification schemes have been proposed for cuff tear arthropathy and used for scientific and clinical purposes, even though their reliability has not been established and compared as of yet. MATERIALS AND METHODS: Two observers (O1 and O2) twice independently classified 52 shoulder radiographs into the cuff arthropathy schemes of Favard, Visotsky-Seebauer, Hamada, and Sirveaux. The schemes of Samilson and Prieto as well as Kellgren and Lawrence, commonly used for osteoarthritis of the shoulder, were also used for comparison. Reliability was tested with the κ coefficient. RESULTS: The intraobserver and interobserver reliabilities were 0.812 for O1, 0.710 for O2, and 0.305 for O1 versus O2 for the Favard classification; 0.868, 0.583, and 0.551, respectively, for the Visotsky-Seebauer classification; 1.000, 0.491, and 0.407, respectively, for the Hamada classification; and 0.852, 0.602, and 0.598, respectively, for the Sirveaux classification. For comparison, the Samilson-Prieto classification reached 0.815, 0.710, and 0.507, respectively, and the Kellgren-Lawrence scheme reached 0.815, 0.713, and 0.430, respectively. DISCUSSION: Of the classification schemes tested, the Sirveaux classification displayed the best reliability overall. The Sirveaux classification only respects alterations of the glenoid, however. Among the schemes respecting both the glenoid and the humerus, the Hamada and Visotsky-Seebauer schemes showed similar reliability compared with the Samilson-Prieto and Kellgren-Lawrence systems, whereas the Favard classification was not as reliable. We therefore recommend the Visotsky-Seebauer or Hamada classification scheme.

Intraarticular lesions in calcifying tendinitis: incidence and association with the acromion index.

INTRODUCTION: Intraarticular pathologies are a common finding during arthroscopy for rotator cuff lesions. Both rotator cuff tears as well as cartilage lesions have been described as correlating with the acromion index. METHODS: In the current study, we aimed to determine the incidence of intraarticular lesions in calcifying tendinitis, to compare the incidence in patients with partial- and full-thickness tears of the rotator cuff, and to determine the acromion index in these groups. The incidence and type of accompanying intraarticular lesions were compared between three consecutive, age-matched groups of 64 patients each: those with calcifying tendinitis (group A), and those with partial- (group B) and full-thickness rotator cuff tears (group C). Also, the acromion index was measured from plain radiographs and compared between the groups. RESULTS: The incidence of intraarticular pathology was 43% in group A, 41% in group B and 84% in group C. The differences between groups A and C as well as B and C were significant (p < 0.0001), but not between groups A and B (p = 0.858). Even though the acromion index was larger in group C than in the other two groups, the difference was not significant (A vs. B, p = 0.505; A vs. C, p = 0.180; and B vs. C p = 0.446). The incidence and type of intraarticular lesions in calcifying tendinitis are comparable to age-matched shoulders with partial- rather than full-thickness rotator cuff tears. CONCLUSION: The acromion index is not different between shoulders with calcifying tendinitis, and partial- or full-thickness rotator cuff tears.

Infections after bone allograft surgery: a prospective study by a hospital bone bank using frozen femoral heads from living donors.

In the advent of the EU guidelines 2004/23/EG and 2006/17/EG requiring extensive safety and quality steps in bone banking, the prevalence and risk of infection disease transmission from bone allograft needs to be reconsidered. Therefore, we prospectively reviewed the screening process of bone donations and the outcome of surgeries utilizing bone allografts from our internal hospital bone bank with regard to infections according to CDC criteria. One-hundred and eighty-eight allogenic bone transplantation procedures in 160 patients were followed-up for 12-64 months (mean 32 months). Bacterial infection occurred in 11 patients, the overall infection rate therefore was 6.9%. After review of the clinical and intraoperative findings, none of the infections were likely to have been caused by the bone graft. Although no follow-up serologic testing was performed, no HIV of hepatitis infections were observed. Frozen bone allografts derived from live donors and provided by hospitals can generally be considered safe. However, without new and relevant clinical expertise, continuing this technique will be impeded by the new EU guidelines and their national implementations.

Dynamic stabilization of the lumbar spine.

This study analyzed the outcome of patients treated with total disk replacement and posterior dynamic stabilization. For pathologies of different origin, dynamic stabilization of the lumbar spine is a novel alternative to fusion surgery. Although a physiological reconstruction of the sagittal profile was not always achieved, improvement was seen in all subscales of the clinical outcome measures in both treatment groups. Posterior dynamic stabilization and total disk replacement are promising alternatives to fusion with acceptable morbidity for strictly defined indications.

The impact of total lumbar disc replacement on segmental and total lumbar lordosis.

BACKGROUND: One of the goals of total lumbar disc replacement is restoration of the physiological sagittal alignment. There is little evidence if this goal is reached in vivo and further affects the clinical outcome. METHODS: In 29 patients segmental lordosis and total lumbar lordosis were measured on X-rays pre- and postoperatively. The functional outcome was evaluated prospectively with the Visuell Analogue Scale, Oswestry Low Back Pain Disability Questionnaire and Short Form 36 Health Survey Questionnaire. FINDINGS: Total disc replacement increased segmental lordosis significantly while total lumbar lordosis remained unchanged. Preoperative segmental/total lumbar lordosis was physiological in 52%/91% of the patients. Postoperatively these values changed to 72% for segmental- and 94% for total lumbar lordosis. No difference could be observed in clinical outcome measures in patients with physiological and unphysiological segmental lordosis. INTERPRETATION: Monosegmental total disc replacement increases the segmental lordosis in most of the cases while preserving the total lumbar lordosis which produces a decrease of lordotic angle in the adjacent segment(s). Although short term clinical results are not affected, the segmental lordosis increase and adjacent segment(s) alteration may influence long term outcome.

Posterior stabilisation of a malignant cervico-thoracic vertebral bone defect.

Oesophageal cancer is frequently complicated by malignant fistulae. Necrosis of the tumour following radiotherapy or chemotherapy may lead to the development of fistulae between the oesophagus and adjacent tissues and organs. We report the expansion of an extra-luminal oesophageal cancer after resection, invading the cervico-thoracic spine, fortunately without neurological deficit, and leading to instability and formation of a malignant fistula linking the tracheo-bronchial tree to the subarachnoidal space. To prevent imminent paraplegia and to alleviate severe pain, we rigidly stabilised the spine at the cervico-thoracic junction using an angle-stable system through a single posterior approach. Further postoperative follow-up revealed no signs of neurological deterioration. Cervico-thoracic stability was preserved until the patient died nearly five months postoperatively. This case shows that posterior stabilisation and decompression may be a palliative option for patients with imminent paraplegia and severe pain due to advanced tumour infiltration of the cervico-thoracic spine.

Distractible vertebral body replacement for the thoracic and lumbar spine.

We retrospectively evaluated the results after corporectomy and vertebral body replacement in 40 patients with thoracic or lumbar spine collapse due to tumour osteolysis, unstable fractures, spondylodiscitis and Paget's disease. They underwent posterior transpedicular instrumentation followed 7 to 21 days later by vertebral body replacement with a distractible device, the "Obelisc" cage, filled up with autogenous/allogeneic bone graft. The mean residual kyphosis after surgery was only 13.8 degrees. After a mean follow-up period of 16.3 months, there was a mean loss of correction of 1.1 degrees. Perioperative complications occurred in 25 patients (62.5%); one died of septic shock, and the others were treated conservatively. Postoperatively, neurological improvement was noted in 8 patients. Using this in situ distractible vertebral body replacement system to achieve intraoperative stabilisation, neurological improvement and minimal postoperative displacement were achieved with an acceptable perioperative risk.

Osteoarthritis--a rare indication for atlantoaxial fusion. A case report and review of the literature.

The authors report a case of C1-C2 fusion which was performed in a 64-year-old woman with unilateral atlantoaxial osteoarthritis, who consulted because of incapacitating occipital pain and decreased cervical rotation without neurological deficit. The diagnosis of unilateral C1-C2 osteoarthritis was confirmed by an open-mouth radiograph, a bone-scan, a computerised tomography scan, and magnetic resonance imaging. C1-C2 fusion was performed using a computer assisted navigation system and posterior instrumentation. This resulted in marked relief of pain, and distinct improvement in quality of life. The prevalence of atlantoaxial osteoarthritis is about four per cent in patients suffering from peripheral or spinal osteoarthritis. However, many primary-care providers are not familiar with this entity. C1-C2 fusion remains rare, due to the difficulties related to the diagnosis of atlantoaxial osteoarthritis, its established non-operative treatment options, and the fact that it has not received adequate attention in the orthopaedic literature. However, based on review of the literature, it can be stated that C1-C2 fusion is an effective and safe procedure providing distinct reduction of pain and increased quality of life in case of failure of conservative treatment.

Prevalence of sleep deprivation in patients with chronic neck and back pain: a retrospective evaluation of 1016 patients.

BACKGROUND: Chronic low back pain (CLBP) and chronic neck pain (CNP) have become a serious medical and socioeconomic problem in recent decades. Patients suffering from chronic pain seem to have a higher prevalence of sleep disorders. PURPOSE: To calculate the prevalence of sleep deprivation in patients with CLBP and CNP and to evaluate the factors that may contribute to sleep impairment. METHODS: This study was a retrospective evaluation of 1016 patients with CNP and CLBP who consulted an orthopedic department at a university hospital. Factors assessed were gender, age, diagnosis, grade of sleep deprivation, pain intensity, chronification grade, and migrational background. Pearson's chi-squared test was performed to calculate the relationship between these factors and the grade of sleep deprivation. Regression analysis was performed to explore the correlation between the grade of sleep deprivation and age, pain intensity, and chronification grade. RESULTS: A high prevalence of sleep deprivation (42.22%) was calculated in patients with CNP and CLBP, even when analgesics had been taken. About 19.88% of the patients reported serious sleep impairments (ie, <4 hours of sleep per night). The grade of sleep deprivation did not correlate with the gender or age distribution. A significant relationship was found between the grade of sleep deprivation and pain intensity, failed back surgery syndrome, and patients with a migrational background. There was a moderate relationship with intervertebral disc disease and no relationship with spinal stenosis. CONCLUSION: Sleep disturbance should be assessed when treating patients with CNP or CLBP, especially in patients with higher pain intensity, failed back surgery syndrome, and a migrational background. Further research is needed to explore the complex relationship of sleep disturbance and chronic pain.

Does the diagnosis influence the outcome in a multimodal outpatient pain management program for low back pain and sciatica? A comparative study.

The literature describes multimodal pain-management programs as successful therapy options in the conservative treatment of chronic low back pain. Yet, the intensity and inclusion criteria of such programs remain debatable. In many studies, the pain originating from spinal structures is described as nonspecific low back pain - a diffuse diagnosis without serious implications. The purpose of this study is to compare the short-term outcomes between patients suffering from sciatica due to a discus intervertebralis herniation and those suffering from low back pain caused by facet joint disease after 3 weeks of treatment in an intense multimodal outpatient program in the Department of Orthopaedic Surgery at the university hospital.

Radiation dose reduction in CT-guided periradicular injections in lumbar spine: Feasibility of a new institutional protocol for improved patient safety.

BACKGROUND: Image guided spinal injections are successfully used in the management of low back pain and sciatica. The main benefit of CT-guided injections is the safe, fast and precise needle placement, but the radiation exposure remains a serious concern. The purpose of the study was to test a new institutional low-dose protocol for CT-guided periradicular injections in lumbar spine to reduce radiation exposure while increasing accuracy and safety for the patients. METHODS: We performed a retrospective analysis of a prospective database during a 4-month period (Oct-Dec 2011) at a German University hospital using a newly established low-dose-CT-protocol for periradicular injections in patients suffering from lumbar disc herniation and nerve root entrapment. Inclusion criteria were acute or chronic nerve root irritation due to lumbar disc hernia, age over 18, compliance and informed consent. Excluded were patients suffering from severe obesity (BMI > 30), coagulopathy, allergy to injected substances, infection and non-compliant patients. Outcome parameters consisted of the measured dose length product (mGycm2), the amount of scans, age, gender, BMI and the peri-interventional complications. The results were compared to 50 patients, treated in the standard-interventional CT-protocol for spinal injections, performed in June-Oct 2011, who met the above mentioned inclusion criteria. RESULTS: A total amount of 100 patients were enrolled in the study. A significant radiation dose reduction (average 85.31%) was achieved using the institutional low-dose protocol compared to standard intervention mode in CT-guided periradicular injections in lumbar spine. Using the low-dose protocol did not increase the complications rate in the analyzed cohort. CONCLUSIONS: Low-dose-CT-protocols for lumbar perineural injections significantly reduce the exposure to radiation of non-obese patients without an increase of complications. This increases long-time patient safety of stochastic radiation effects.

Intensive interdisciplinary outpatient pain management program for chronic back pain: a pilot study.

BACKGROUND: Chronic back pain is relatively resistant to unimodal therapy regimes. The aim of this study was to introduce and evaluate the short-term outcome of a three-week intensive multidisciplinary outpatient program for patients with back pain and sciatica, measured according to decrease of functional impairment and pain. METHODS: The program was designed for patients suffering from chronic back pain to provide intensive interdisciplinary therapy in an outpatient setting, consisting of interventional injection techniques, medication, exercise therapy, back education, ergotherapy, traction, massage therapy, medical training, transcutaneous electrical nerve stimulation, aquatraining, and relaxation. RESULTS: Based on Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) scores, a significant improvement in pain intensity and functionality of 66.83% NRS and an ODI of 33.33% were achieved by our pain program within 3 weeks. CONCLUSION: This paper describes the organization and short-term outcome of an intensive multidisciplinary program for chronic back pain on an outpatient basis provided by our orthopedic department, with clinically significant results.

Effective Dose of CT-Guided Epidural and Periradicular Injections of the Lumbar Spine: A Retrospective Study.

Spinal injection procedures can be performed blindly or, more accurately, with fluoroscopic or computed tomography (CT) guidance. Radiographic guidance for selective nerve root blocks and epidural injections allows an accurate needle placement, reduces the procedure time and is more secure for the patient, especially in patients with marked degenerative changes and scoliosis, resulting in a narrowing of the interlaminar space. Limiting factors remain the availability of scanners and the radiation dose. Interventional CT scan protocols in axial CT-acquisition mode for epidural and periradicular injections help to limit the radiation dose without a significant decrease of image quality. The purpose of this retrospective study was to analyze the effective radiation dosage patients are exposed during CT-guided epidural lumbar and periradicular injections. A total amount of n=1870 datasets from 18 months were analyzed after multiplying the dose length product with conversion factor k for each lumbar segment. For lumbar epidural injections (n=1286), a mean effective dose of 1.34 mSv (CI 95%, 1.30-1.38), for periradicular injections (n=584) a mean effective dose of 1.38 mSv (CI 95%, 1.32-1.44) were calculated.

Effective radiation dose reduction in computed tomography-guided spinal injections: a prospective, comparative study with technical considerations.

Despite the good general patient acceptance, high patient comfort, safety and precision in the needle placement, exposure to radiation in computed tomography (CT)-guided spinal interventions remains a serious concern, and is often used to argue against its use. The aim of this study was to determine the technical possibilities of reducing the radiation dose in CT-guided epidural and periradicular injections in lumbar spine. We evaluated the possibilities of reducing radiation dose to the patient and operator during CT-guided injections on the lumbar spine using the following steps: significant reduction of the tube current and energy used for the topogram-acquisition, narrowing the area of interest in spiral CT-mode and reduction of tube current and radiation energy in the final intervention mode. Fifty-three CT-guided spinal injections were performed in the lumbar spine (34 epidural lumbar, 19 lumbar periradicular) using a low-dose protocol in non-obese patients and compared with 1870 CT-guided injections from the year 2010, when a standard dose protocol was used. Technical considerations on radiation dose reduction were provided. An average dose reduction of 85% was achieved using the low-dose protocol in CT-guided epidural and periradicular injections in lumbar spine without showing any effect on safety or precision.