Development of new cartilage lesions after ACL reconstruction is associated with abnormal knee rotation.

PURPOSE: The purpose of this study is to examine the association between the development of articular cartilage pathology and knee rotation after single-bundle anterior cruciate ligament (ACL) reconstruction. METHODS: Seventeen patients that underwent single-bundle ACL reconstruction and did not have any cartilage lesions at the time of surgery based on the Outerbridge classification or meniscal injury that required meniscectomy > 20% were examined by MRI and in the biomechanics laboratory at a 6-year minimum follow-up. Cartilage lesions that occurred after reconstruction were graded on MRI according to a modified Noyes scale. For cartilage evaluation, the lateral and medial femoral condyles were divided into 9 segments each (lateral, central, and medial third and each third was divided into anterior, central, and posterior segment). Tibial rotation during a pivoting task was measured with optoelectronic motion analysis system and side-to-side differences of tibial rotation between the reconstructed and contralateral intact knees were calculated. The association between the total modified Noyes scale score (outcome variable) and side-to-side differences of tibial rotation after controlling for meniscectomy and meniscal repair was investigated with hierarchical regression models. RESULTS: Side-to-side difference of tibial rotation was associated with total modified Noyes scale score (p = 0.015, ß = 0.667, adjusted R2 = 42.1%). All patients developed new cartilage lesions in MRI located mainly at the central region of the lateral femoral condyle and less frequently in the central and anterior regions of the medial femoral condyle. CONCLUSION: Abnormally increased tibial rotation that persists after ACL-R is significantly associated with the development of new articular cartilage lesions at mean 8.4 years after reconstruction which were located mainly at the central region of the LFC and secondarily in the central and anterior regions of the MFC (more superficial lesions). These findings suggest that there is emerging evidence that abnormal rotational kinematics is a potential risk factor for the pathogenesis and onset of posttraumatic articular cartilage degeneration after ACLR. LEVEL OF EVIDENCE: IV.

Intra-Articular Application of Sluijter-Teixera Poisson Pulsed Radiofrequency in Symptomatic Patients with Knee Osteoarthritis: Focus upon Clinical Efficacy and Safety.

Purpose: To retrospectively evaluate the effectiveness of intra-articular application of Sluijter-Teixera Poisson pulsed radiofrequency (STP PRF) in knee osteoarthritis symptomatic patients with chronic pain refractory to conservative therapies. Materials and Methods: Institutional database research of two centers identified 39 cases of knee osteoarthritis patients treated with intra-articular STP PRF. Pain prior and one-week and one-, three-, six-, and twelve-month post-STP PRF was compared by means of a numeric visual scale (NVS) questionnaire. Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system was used for complications reporting. Mean patient age was 71.59 ± 11.99 years, mean body mass index was 30.23 ± 4.69, and male/female ratio was 9/30. Results: Mean baseline pain score was 8.31 ± 1.70 NVS units. This was reduced to a mean value of 0.90 ± 1.50 NVS units one-week post-RF, 1.08 ± 1.53 at one month, 1.54 ± 1.88 at three months, 2.33 ± 2.17 at six months, and 3.23 ± 2.23 at 12 months of follow-up (p < 0.01). Pain decrease of more than 4 NVS units was noticed in 35/39 knees (89.7%) at first week, 36/39 knees (92.3%) at first month, 35/39 knees (89.7%) at three months, 32/39 knees (82.1%) at six months, and 25/39 knees (64.1%) at one year. There was no recurrence during the follow-up. No complication was observed. Conclusions: Percutaneous, intra-articular application of STP PRF is an effective and safe technique for chronic pain reduction in patients with knee osteoarthritis. Results seem to be reproducible and long lasting with significant patient satisfaction at 12-month follow-up.

Percutaneous computed tomography-guided radiofrequency ablation of a spinal osteoid osteoma abutting the dura: a case report and review of the literature.

PURPOSE: Osteoid osteomas in the spine constitute a challenging group for both surgical and percutaneous approaches. Purpose of the present study is to report a case report of a spinal osteoid osteoma in a challenging spinal location and review literature for safety and efficacy of the technique. METHODS: We report a case of spinal osteoid osteoma extending in the epidural space and abutting the dura in a pediatric patient treated by percutaneous computed tomography-guided radiofrequency ablation. This is not a systematic review of the literature. A number of separate literature searches were performed. Non-English studies and case reports were excluded from the study. All references of the obtained articles were also evaluated for any additional information. RESULTS: Although all prophylactic measures were taken (hydrodissection, thermocouples and neurophysiologic monitoring) and the procedure was uneventful, patient within three hours, was unable to raise or bend the unilateral lower extremity below the knee. Pain reduction was significant from the first morning post-ablation and during the follow-up period of 18 months. MR scan was within normal limits. Dexamethasone was iv injected for 24 h and prescribed per os for 7 days. At follow-up 1 week later mobility of the lower extremity had returned to normal. CONCLUSION: As far as spine ablation is concerned, all prophylactic measures should be taken; neurophysiologic monitoring seems to be more sensitive than temperature measurement. Intravenous and per os corticosteroids are extremely useful in case of nerve damage.

A Technical Report on the Performance of Percutaneous Cryoneurolysis of Splanchnic Nerves for the Treatment of Refractory Abdominal Pain in Patients with Pancreatic Cancer: Initial Experience.

PURPOSE: To report our preliminary results upon feasibility, efficacy and safety of percutaneous splanchnic nerves cryoneurolysis for the treatment of abdominal pain refractory to conservative medication in patients with pancreatic cancer MATERIALS METHODS: Institutional database research (retrospective review of prospectively collected data from April 2019 till August 2020) identified 5 patients with pancreatic cancer and pain refractory to conservative medication who underwent percutaneous cryoneurolysis of splanchnic nerves. In all patients, percutaneous cryoneurolysis was performed with posterolateral paravertebral approach using a 17 Gauge cryoprobe under computed tomography guidance and local anesthesia. Self-reported pain scores were assessed before and at the last follow-up using a pain inventory with visual analog scale (VAS) units. RESULTS: Mean patient age was 63.81 years (male-female: 3-2). Mean pain score prior to cryoanalgesia of splanchnic nerves was 9.4 VAS units. This score was reduced to a mean value of 2.6, 2.6 and 3 VAS units at 1, 3 and 6 months of follow-up, respectively. All patients reported significantly reduced analgesic usage. No complication was reported according to the CIRSE classification system. The mean procedure time was 44.4 min (range 39-50 min), including local anesthesia, cryoprobe(s) placement, ablation and post-procedural CT evaluation. CONCLUSION: Percutaneous cryoanalgesia of the splanchnic nerves is a minimally invasive, safe and effective procedure for pancreatic cancer pain relief. A larger, randomized trial is justified to substantiate these findings.

Percutaneous imaging-guided techniques for the treatment of benign neuropathic pain.

To date, conservative management including physical and/or systemic pharmacologic therapy is considered as the first line approach for the management of neuropathic pain syndromes. In the era of an opioid overdose crisis with an increased concern upon the risks and harms arising from the misuse of medicines for pain management, percutaneous minimally invasive techniques such as nerve infiltrations as well as neurolysis or neuromodulation techniques can be proposed to control pain and improve life quality. Computed tomography can serve as an ideal guiding technique due to its specific characteristics including precise anatomic delineation, high spatial resolution and good tissue contrast. The purpose of this review is to make the reader familiar with the most common indications for minimally invasive imaging-guided techniques in patients with neuralgia and provide current evidence regarding technical considerations.

Percutaneous cryoanalgesia for pain palliation: Current status and future trends.

Cryoanalgesia, otherwise termed cryoneurolysis, refers to application of extreme cold upon peripheral nerves for palliation of pain associated to nerve lesions or biomechanical syndromes of neoplastic and non-neoplastic substrate. Application of cryoanalgesia initiates a cascade of pathophysiologic events interrupting nerve conduction of painful stimuli without irreversible nerve damage. Cryoanalgesia is considered a safe procedure with minimal risk of complications when performed with percutaneous approaches under imaging guidance. In the era of an opioid overdose crisis, cryoanalgesia can be proposed as an alternative aiming at controlling pain and improving life quality. Imaging guidance has substituted open surgical and nerve stimulation approaches in nerve identification, significantly contributing to the minimally invasive character of percutaneous approaches. Ultrasound or computed tomography can serve as low cost, ideal guiding techniques due to their abilities for precise anatomic delineation, high spatial resolution and good tissue contrast. The purpose of this review is to become familiar with the most common imaging guided percutaneous cryoanalgesia indications, to learn about different technical considerations during performance providing the current evidence. Controversies concerning products will be addressed.

RADIATION DOSES TO THE EYE LENS AND FOREHEAD OF INTERVENTIONAL RADIOLOGISTS: HOW HIGH AND ON WHAT GROUNDS?

The aim of the study was to measure and evaluate the radiation dose to the eye lens and forehead of interventional radiologists (IRs). The study included 96 procedures (lower-limb percutaneous transluminal angioplasties, embolisations/chemoembolisations and vertebroplasties) performed by 6 IRs. A set of seven thermoluminescence dosemeters was allocated to each physician. The highest dose per procedure was found for the left eye lens of the primary operator in vertebroplasties (1576 µSv). Left and right eye doses were linearly correlated to left and right forehead doses, respectively. A workload-based estimation of the annual dose to participating IRs revealed that the occupational dose limit for the eye lens can be easily exceeded. The left eye dose of ΙRs must be routinely monitored on a personalised basis. Τhe left eye dose measurement provides a reliable assessment of the ipsilateral forehead dose, along with valid estimations for the right eye and right forehead doses.

Computed Tomography-Guided Percutaneous Infiltrations for Piriformis Syndrome: A Single-Center Retrospective Study.

Piriformis syndrome (PS), first described by Yeoman in 1928, is a general term referring to low back pain, sciatica, and instability. PS has a 6% incidence rate worldwide. In this study, we aim to retrospectively evaluate the effectiveness of computed tomography (CT)-guided percutaneous infiltration in a series of consecutive PS patients who have symptoms that are refractory to conservative therapies. An institutional database search identified 20 such consecutive patients who underwent infiltration with a mixture of long-acting corticosteroid and local anesthetic. Preoperational evaluation included physical examination and magnetic resonance imaging. The correct position of the 22-gauge spinal needle was verified with CT scan after contrast medium injection. Pain measured before the procedure and at 1 wk and 1, 6, and 12 mo after the procedure was compared by means of a numeric visual scale (NVS) questionnaire. The mean pain score before CT-guided percutaneous infiltration was 8.95 ± 1.432 NVS units. This score was reduced to a mean value of 0.85 ± 0.933 units at 1 wk, 0.90 ± 0.852 at 1 mo, 1.10 ± 1.165 at 6 mo, and 1.20 ± 1.399 at 12 mo follow-up (p < 0.001). Two patients of 20 (10%) underwent a second infiltration that was performed at 7 and 10 d after the first, respectively. No complications were observed. CT-guided infiltration seems to be a feasible, efficacious, and safe approach for pain reduction and mobility improvement in patients with symptomatic PS.

Five-Years Outcome Analysis of 142 Consecutive Hepatocellular Carcinoma Patients Treated with Doxorubicin Eluting Microspheres 30-60 µm: Results from a Single-Centre Prospective Phase II Trial.

PURPOSE: To assess prospectively long-term results of doxorubicin-loaded HepaSphere 30-60 µm in consecutive patients with hepatocellular carcinoma (HCC) not amenable to curative treatments. PATIENTS AND METHODS: Single-center study from June 2011 to December 2015 in 151 patients treated with 75 mg of doxorubicin per HepaSphere vial. Baseline: Barcelona Clinic Liver Cancer BCLC A/B was 49.3%/50.7%, and median diameter 6.1 cm (mean 6.7 ± 2.0). Liver function, local response (mRECIST), liver time to progression (LTTP), progression-free survival (PFS), overall survival (OS) and adverse events (AEs) were recorded. RESULTS: Final analysis included 142 patients with median follow-up of 46.8 months (range 4-72) without grade 4/5 AEs, and 30-day mortality was 0%. Mean number of scheduled treatments was 2.6 (range 1-3) and on demand 3 (range 1-8). Complete response for single tumor ≤ 5 cm was 75.0% and 66.7% for Child A and Child B, while for > 5 cm was 28.6% and 11.8%, respectively. OS was 31.0 months (mean 33.3 ± 15.2; range 8-69), notably for BCLC A 41 months (mean 41.1 ± 15.3; range 13-69) and for BCLC B 26.0 (mean 26.0 ± 10.5; range 8-51). OS at 1, 3 and 5 years: 95.8%, 75.7% and 21.4% for BCLC A, and 94.4%, 36.1% and 2.7% for BCLC B. Median LTTP for BCLC A was 11 months (mean 11.9 ± 4.7; range 3-24) and 7.5 for BCLC B (mean 7.9 ± 2.9). Local response was significant for OS and LTTP (p < 0.0001), while size and lesion number affected LPFS and OS (p < 0.001). CONCLUSIONS: HepaSphere 30-60 µm loaded with doxorubicin provides a safe and effective treatment option for patients with HCC.

Interventional radiology techniques for pain reduction and mobility improvement in patients with knee osteoarthritis.

Osteoarthritis of the knee is the most common cause of chronic knee pain being more prevalent in middle-aged and elderly patients. Symptomatic patients complain of pain and mobility impairment. Therapeutic armamentarium includes physical therapy, oral pharmacologic therapy, intra-articular injections, nerve ablation or modulation, trans-catheter arterial embolization, minimally invasive arthroscopic treatment and partial or total knee arthroplasty. Interventional radiology therapies for knee osteoarthritis include intra-articular injections, neurotomy and neuromodulation techniques as well as transcatheter intra-arterial therapies. These therapies aim to control pain and inflammation, improve mobility and function whilst the novel cell-based therapies have the potential for bone and cartilage regenerative repair facilitating the delay to surgery. The purpose of this review is to illustrate the technical aspects, the indications and the methodology of local therapies for knee osteoarthritis performed by interventional radiologists and provide current evidence.

Intra-articular application of pulsed radiofrequency combined with viscosupplementation for improvement of knee osteoarthritis symptoms: a single centre prospective study.

OBJECTIVES: To prospectively evaluate the effectiveness of intra-articular application of pulsed radiofrequency (PRF) combined with viscosupplementation in patients with knee osteoarthritis suffering from chronic pain refractory to conservative therapies. METHODS: During a 30-month period, PRF combined with viscosupplementation was performed on 53 cases of knee osteoarthritis (45 patients, 8/45 with bilateral knee osteoarthritis). Pre-operational imaging included standard knee X-rays on anterior-posterior and lateral views used to evaluate patients according to the Kellgren-Lawrence classification. Pain, prior, one week/one, 6 and 12 months post were compared by means of a numeric visual scale (NVS) questionnaire. RESULTS: Mean pain score prior to PRF was 8.19 ± 1.4 NVS units. This score was reduced to a mean value of 2.47 ± 2.5 NVS units at 1 week after, 2.55 ± 2.6 at 1 month, 3.1 ± 2.8 at 6 months and 5.02 ± 3.09 at 12 months of follow-up (p < 0.01). Overall mobility improved in 47/53 (88.6%) patients. No complication was observed. CONCLUSIONS: Combining PRF with viscous supplementation is an effective and safe technique for palliative management of chronic pain in patients with knee osteoarthritis. Results seem to be reproducible and long lasting. There seems to be a need of repeating the session at 1 year.

Percutaneous microwave ablation of renal cell carcinoma using a high power microwave system: focus upon safety and efficacy.

OBJECTIVES: Percutaneous ablation is an expanding, minimally invasive approach for small- to medium-sized renal masses. The purpose of this study is to review safety, and mid-term efficacy of percutaneous microwave ablation (MWA) for Renal Cell Carcinoma (RCC) treatment using a high power microwave system. METHODS AND MATERIALS: Institutional database research identified 50 consecutive patients with a single lesion resembling renal cell carcinoma in CT and MRI who underwent percutaneous microwave ablation using a high power microwave system. All patients underwent biopsy on the same session with ablation using an 18G semi-automatic soft tissue biopsy needle. Contrast-enhanced computed tomography or magnetic resonance imaging was used for post-ablation follow-up. Patient and tumour characteristics, microwave technique, complications and pattern of recurrence were evaluated. RESULTS: Mean patient age was 74 years (male-female: 31-19). Average lesion size was 3.1 cm (range 2.0-4.3 cm). Biopsy results report RCC (n = 48), inflammatory myofibroblastic tumour (n = 1), and non-diagnostic sample (n = 1). The 3-year overall survival was 95.8% (46/48). Two patients died during the 3-year follow-up period due to causes unrelated to the MW ablation and to the RCC. Minor complications including haematomas requiring nothing but observation occurred at 4% (2/50) of the cases. Local recurrence of 6.25% (3/48) was observed with 2/3 cases being re-treated achieving a total clinical success of 97.9% (47/48 lesions). CONCLUSIONS: Percutaneous microwave ablation of RCC using a high power microwave system is a safe and efficacious technique for the treatment of small- to medium-sized renal masses.

Pain management: The rising role of interventional oncology.

Patients with early or metastatic cancer may suffer from pain of different origins. The vast majority of these patients are not adequately treated by means of systemic analgesia and radiotherapy. Percutaneous neurolysis is performed using chemical agents or thermal energy upon sympathetic nervous system plexus for pain reduction and life quality improvement. Ablation and vertebral augmentation are included in clinical guidelines for metastatic disease. As far as the peripheral skeleton is concerned bone augmentation and stabilization can be performed by means of cement injection either solely performed or in combination to cannulated screws or other metallic or peek implants. This review describes the basic concepts of interventional oncology techniques as therapies for cancer pain management. The necessity for a tailored-based approach applying different techniques for different cases and locations will be addressed.

Computed tomography-guided radiofrequency ablation of intra-articular osteoid osteoma: a single centre's experience.

OBJECTIVE: To evaluate safety and efficacy of radiofrequency ablation (RFA) in the treatment of painful intra-articular osteoid osteoma. MATERIALS AND METHODS: During the last 3 years, 15 patients underwent computed tomography (CT)-guided biopsy and RFA of symptomatic intra-articular osteoid osteoma. In order to assess and sample the nidus, a coaxial bone biopsy system was used. Biopsy was performed and followed by ablation session with osteoid osteoma protocol in all cases. Procedure time (i.e. drilling including local anaesthesia and ablation), amount of scans, the results of biopsy and pain reduction during follow-up period are reported. RESULTS: Access to the nidus through normal bone, biopsy and electrode insertion was technically feasible in all cases. Median procedure time was 54 min. Histologic verification of osteoid osteoma was performed in all cases. Median amount CT scans, performed to control correct positioning of the drill and precise electrode placement within the nidus was 9. There were no complications or material failure reported in our study. There was no need for protective techniques of the articular cartilage. Pain reduction was significant from the first morning post ablation and complete at the one week and during the follow-up period. No recurrences were noted. CONCLUSIONS: RFA under CT guidance is a safe and efficient technique for the treatment of painful intra-articular osteoid osteoma. Imaging guidance, extra-articular access through normal bone and exact positioning of the needle-electrode inside the nidus facilitate safety of the technique and prevention of damage to the articular cartilage.

Percutaneous Biopsy and Radiofrequency Ablation of Osteoid Osteoma with Excess Reactive New Bone Formation and Cortical Thickening Using a Battery-Powered Drill for Access: A Technical Note.

PURPOSE: To report our experience with the use of a battery-powered drill in biopsy and radiofrequency ablation of osteoid osteoma with excess reactive new bone formation. The battery-powered drill enables obtaining the sample while drilling. MATERIALS AND METHODS: During the last 18 months, 14 patients suffering from painful osteoid osteoma with excess reactive new bone formation underwent CT-guided biopsy and radiofrequency ablation. In order to assess and sample the nidus of the osteoid osteoma, a battery-powered drill was used. Biopsy was performed in all cases. Then, coaxially, a radiofrequency electrode was inserted and ablation was performed with osteoid osteoma protocol. Procedure time (i.e., drilling including local anesthesia), amount of scans, technical and clinical success, and the results of biopsy are reported. RESULTS: Access to the nidus through the excess reactive new bone formation was feasible in all cases. Median procedure time was 50.5 min. Histologic verification of osteoid osteoma was performed in all cases. Radiofrequency electrode was coaxially inserted within the nidus and ablation was successfully performed in all lesions. Median amount CT scans, performed to control correct positioning of the drill and precise electrode placement within the nidus was 11. There were no complications or material failure reported in our study. CONCLUSIONS: The use of battery-powered drill facilitates access to the osteoid osteoma nidus in cases where excess reactive new bone formation is present. Biopsy needle can be used for channel creation during the access offering at the same time the possibility to extract bone samples.

Percutaneous Augmented Peripheral Osteoplasty in Long Bones of Oncologic Patients for Pain Reduction and Prevention of Impeding Pathologic Fracture: The Rebar Concept.

PURPOSE: To evaluate clinical efficacy/safety of augmented peripheral osteoplasty in oncologic patients with long-term follow-up. MATERIALS AND METHODS: Percutaneous augmented peripheral osteoplasty was performed in 12 patients suffering from symptomatic lesions of long bones. Under extensive local sterility measures, anesthesiology care, and fluoroscopic guidance, direct access to lesion was obtained and coaxially a metallic mesh consisting of 25-50 medical grade stainless steel micro-needles (22 G, 2-6 cm length) was inserted. PMMA for vertebroplasty was finally injected under fluoroscopic control. CT assessed implant position 24-h post-treatment. RESULTS: Clinical evaluation included immediate and delayed follow-up studies of patient's general condition, NVS pain score, and neurological status. Imaging assessed implant's long-term stability. Mean follow-up was 16.17 ± 10.93 months (range 2-36 months). Comparing patients' scores prior (8.33 ± 1.67 NVS units) and post (1.42 ± 1.62 NVS units) augmented peripheral osteoplasty, there was a mean decrease of 6.92 ± 1.51 NVS units. Overall mobility improved in 12/12 patients. No complication was observed. CONCLUSION: Percutaneous augmented peripheral osteoplasty (rebar concept) for symptomatic malignant lesions in long bones seems to be a possible new technique for bone stabilization. This combination seems to provide necessary stability against shearing forces applied in long bones during weight bearing.

Percutaneous treatment of cervical and lumbar herniated disc.

Therapeutic armamentarium for symptomatic intervertebral disc herniation includes conservative therapy, epidural infiltrations (interlaminar or trans-foraminal), percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments for intervertebral disc herniation which can be performed as outpatient procedures. They can be classified in 4 main categories: mechanical, thermal, chemical decompression and biomaterials implantation. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. Indications include the presence of a symptomatic, small to medium sized contained intervertebral disc herniation non-responding to a 4-6 weeks course of conservative therapy. Contraindications include sequestration, infection, segmental instability (spondylolisthesis), uncorrected coagulopathy or a patient unwilling to provide informed consent. Decompression techniques are feasible and reproducible, efficient (75-94% success rate) and safe (>0.5% mean complications rate) therapies for the treatment of symptomatic intervertebral disc herniation. Percutaneous, imaging guided, intervertebral disc therapeutic techniques can be proposed either as an initial treatment or as an attractive alternative prior to surgery for the therapy of symptomatic herniation in both cervical and lumbar spine. This article will describe the mechanism of action for different therapeutic techniques applied to intervertebral discs of cervical and lumbar spine, summarize the data concerning safety and effectiveness of these treatments, and provide a rational approach for the therapy of symptomatic intervertebral disc herniation in cervical and lumbar spine.

Effective and ovarian dose in PA conventional and rotational 3D hysterosalpingography examinations.

The purpose of this study was to compare effective and ovarian doses (E and OD, respectively) in hysterosalpingography (HSG) examinations performed with conventional posterioanterior (PA) projections and rotational 3D (3D) techniques. 29 HSG examinations (11 conventional and 18 3D), were performed using a digital C-arm angiographic system. In the conventional technique, we used posterioanterior (PA) instead of an anterioposterior (AP) projection normally used according to the international literature. All information concerning exposure conditions for each patient, were recorded. Thermoluminescent dosimeters (TLDs) were attached on the skin of each patient over the ovaries. In conventional HSGs, average values were for Dose Area Product (DAP) 0.41 Gycm(2), for Effective Dose (E) 0.15 mSv and for Ovarian Dose (OD) 0.24 mGy. In 3D-HSGs, they were 14.4 Gycm(2), 2.29 mSv and 3.96 mGy correspondingly. Patient doses in 3D-HSGs are of the same order of magnitude with those reported in the literature for conventional technique. However, they are larger compared to the conventional HSG performed with the technique we use in this specific X-ray system. E and OD are much lower with our technique where PA projection and the specific C-arm system are used in comparison with the corresponding values published in the literature for the conventional technique where the AP projection is used.