Intraoperative Image Intensifier Research Articles

Unilateral neurostimulation-assisted cervical epidural anesthesia for upper limb surgeries—a case series

BackgroundThe role of neurostimulation-aided cervical epidural anesthesia (CEA) in shoulder surgery has been described in the literature. The use of nerve stimulators and the infusion of local anesthetic (LA) in the cervical epidural space has also been mentioned. Epidural needle rotation prior to insertion of the catheter is not described, and it is not clear if general anesthesia was administered in these cases.Case presentationIn this case series, we performed CEA at the level of C7-T1 in 12 patients undergoing various surgeries on the proximal open shoulder and mid humerus after informed consent. Ipsilateral motor responses elicited by continuous electrical stimulation were used to identify lateralization of the epidural catheter tip. The placement of catheters was confirmed under an intraoperative image intensifier. Using the median approach at the level of C7-T1, an ipsilateral twitch was noted in all patients. Neurostimulation persisted with an advancement of stimulating catheter 3–4 cm in the cervical epidural space in all patients. A cervical radiograph confirmed the placement of an ipsilateral catheter and contrast injection there upon revealing the spread of the LA agent. All patients had successful awake shoulder and mid-humerus surgeries under sole cervical epidural anesthesia as evidenced by the absence of pain response at the surgical incision.ConclusionsIpsilateral CEA can be offered for unilateral upper limb surgeries. Low volumes of LA can be injected after precise placement of the tip of the catheter corresponding to the level of surgical incision.

An Analysis of 50 Consecutive Total Ankle Replacements Undergoing Preoperative Computerized Tomography Scan-Based, Engineer-Provided Planning From a Single Noninventor, Nonconsultant Surgeon

Preoperative computerized tomography (CT) scan-based, engineer-provided alignment plans and patient-specific pinning blocks for total ankle replacement (TAR) are available for use in the United States. However, nonbiased studies that justify the additional expense associated with this technology through support of the marketed benefits of less procedural complexity, less intraoperative radiation and reduced surgical time, are lacking. Therefore, to verify the manufacturer's proposed benefits, we sought to investigate our experience with this preoperative CT scan-based, engineer-provided plan and patient-specific pinning blocks during primary TAR. In review of our 50 TAR patients, we found that “perfect” radiographic alignment was not consistently achieved and the accuracy of component prediction was modest. Furthermore, the preoperative plans and patient-specific pinning blocks did not simplify the complexity of our operations since the operative time, intraoperative image intensification time and radiation dose per case all exceeded published historical TAR controls. Interestingly, we identified a significant difference in placement accuracy between the arced and flat-top talar component types that were implanted with the arced being more frequently malaligned. We did not find associations between preoperative deformity severity and accuracy of postoperative alignment. These findings suggest that it is imperative to have surgeons continue to rely on their own surgical planning and experience to achieve optimum radiographic alignment rather than depending on engineer-based recommendations or “surface matched” pinning blocks. Ultimately, we were unable to support the purported benefits of this CT scan-based, engineer-provided alignment plan and patient-specific pinning blocks for this manufacturer's primary TAR systems.

Importancia del uso de la imagenología pre e intraoperatoria como herramienta para la planificación de remoción de cuerpo extraño en piso de boca. Presentación de un Caso

Introduction: Body piercings consist of small holes made with a needle in different parts of the skin or body to introduce a jewel or decorative element. In the oral cavity, most piercings are placed in the tongue. However, some complications may occur, and surgical techniques must be used for their removal. These complications present a certain degree of difficulty due to their position and may challenge the ability of the clinician to access the specific anatomical location. The different imaging techniques, from simple radiography to intraoperative techniques such as image intensifiers, have become an extremely useful tool for locating an object in the three dimensions of space, allowing safe location and extraction. Objective: The aim of this study is to report the case of a complication of a body piercing in the oral cavity and how the use of imaging was decisive for surgical planning and for the quick and effective resolution of the case. Material and Methods: A 14-year-old female patient came looking for treatment. Her mother reported the onset of the condition after the insertion of a needle-like metallic object while performing an artistic perforation in the lingual region. Since the girl was unable to extract the object, she sought medical advice at the Carlos Arvelo Military Hospital in Caracas, Venezuela. Subsequently, an imaging study was performed by means of a Computed Tomography to locate the metallic object. It was observed that the foreign body had migrated to the floor of the mouth/sublingual region, requiring the area to be surgically approached. It was also decided to use an intraoperative image intensifier. The removal of the object was performed satisfactorily. Conclusion: The extraction of foreign bodies placed in the lingual and sublingual region represents a challenge for the clinician due to the number of important anatomical structures that pass through that area. This makes clinicians plan their surgical removal using pre- and intraoperative imaging, to find a less traumatic location, reduce surgical time as well as the risk of damaging adjacent anatomical structures.

Posterior (Boyd) approach to terrible triad injuries.

BackgroundA ‘terrible triad injury of the elbow’ (TTIE) refers to an injury pattern involving posterior dislocation of the ulnohumeral joint, fracture of the radial head, and fracture of the coronoid process of the ulna. It is a complex injury to the elbow joint and can result in long-term elbow instability, pain, stiffness, and arthritis. In specific cases, it may be treated conservatively, but in most circumstances, surgical stabilization is advised.The ‘drop sign’ is an objective static radiographically measured ulnohumeral distance of ≥4 mm seen intraoperatively and postoperatively. Although controversial, it may portend postoperative instability and arthritis. The senior author repairs these injuries in a standardized fashion through a modified Boyd rather than a lateral approach. Our aim was to assess the number of cases demonstrating an intraoperative drop sign after surgical treatment of a TTIE with this approach.MethodsWe retrospectively analyzed 22 consecutive patients with 23 acute TTIEs. These injuries were treated by a single surgeon using a modified Boyd (posterior) approach to the elbow. Intraoperative image intensifier x-rays were analyzed by the two authors to assess for a ‘drop sign’.ResultsNone of the 23 cases had ‘drop signs’ on intraoperative imaging after stabilization. No patient has redislocated, underwent reoperation, or had symptoms of instability at follow-up.ConclusionNone of our patient cohort had an intraoperative ‘drop sign’ after standardized stabilization for a TTIE injury using a modified Boyd approach.

A PROSPECTIVE STUDY ANALYSIS OF LIMB LENGTH DISCREPANCY FOLLOWING TOTAL HIP ARTHROPLASTY

Objective: The present study was designed and implemented to assess the incidence and occurrence of LLD in post-hip arthroplasty and also to evaluate the causes of limb length discrepancy both intra- and post-operative period to manage total hip arthroplasty effectively. Methods: It is a prospective study involving 52 patients underwent for THA and conducted in the Department of Orthopedics, Tertiary Care Hospital, Visakhapatnam, India from the period of January 2013 to December 2019. The study used Southern approach or “Moore” approach. All the patients are assessed for limb length discrepancy immediately after the surgery and followed at 6 weeks, 3 months, and after 6 years. Results: Three patients had significant limb length discrepancy among the 52 patients (5.77%) while the remaining had no significant discrepancies in all X-rays which assess the radiological discrepancies in length. The study yields a satisfactory result as very few patients reported LLD during follow-up period and outcomes such as pain alleviation, walking capacity, limping, and patient satisfaction were insignificantly influenced by leg lengthening (p≤0.05). Conclusion: A combination of pre-operative templating, intra-operative marking and usage of intra-operative image intensifier and an understanding of anatomy, biomechanics of hip, and implant design would reduce the error of limb length discrepancy.

Usefulness of intraoperative C-arm image intensifier in reducing errors of acetabular component during primary total hip arthroplasty: an application of Widmer\u2019s method

BackgroundAcetabular prosthesis positioning in total hip arthroplasty (THA) is crucial in reducing the risk of dislocation. There has been minimal research on the proper way to put the acetabular components into the safe zone intraoperatively. Assessment of version by intraoperative imaging intensifier is very valuable. The value of Widmer’s method, using the intraoperative C-arm available to determine cup anteversion was assessed.MethodsOne hundred one hips in 91 patients who underwent primary THA were eligible for inclusion. Utilizing intraoperative C-arm images, measurement was performed using the technique described by Widmer. The values obtained using 3D computed tomography postoperatively, which determined the anteversion of the acetabular component, were regarded as the reference standard.ResultsThe method of Widmer obtained values similar to those obtained using 3D computed tomography and was considered accurate (n.s.). All 101 hips were positioned in the set target zone. Among the 101 hips, the cup position in nine hips (8.9%) was changed. The dislocation rate in our study was 1.0% with all dislocations occurring in hips placed in the target zone. The mean Harris hip score after THA in 1 year was 94.2 (82-98).ConclusionsThe method of Widmer was accurate using intraoperative imaging intensifier for the measurement of the anteversion of the acetabular component during THA, with reference to the anteversion obtained from the 3D computed tomography. Also, utilizing intraoperative C-arm imaging was very useful because it allowed for correction of the position of the acetabular cup.

859 Follow up of distal radius volar plating – No role for post-operative radiographs

Abstract Aim There is no consensus on the follow up for distal radius fractures after fixation. All patients receive intra-operative image intensifier screening to check the adequacy of reduction and implant position. We propose that if a patient is asymptomatic, you do not require post-operative radiographs. Method We conducted a retrospective review of all distal radius fractures operated in our hospital over the last 10 years. Data was collected from electronic records for revision surgery or metalwork removal. Records were assessed for patient symptoms, radiographic findings, and indications for implant removal. Patients had a minimum follow up of 6 months. Results 900 distal radius fixations were performed over a 10-year period, of which 747 were volar plating. 49 patients had volar plates removed. 14 patients had metal work removal and joint release for stiffness. 6 had the plate removal and carpal tunnel neurolysis with release. 11 implant removals for screw prominence. Other operative indications included reduction failure (n = 2), infection (n = 2) and removal in paediatric patients (n = 3). 47 of the 49 patients for implant removal were symptomatic at follow up. Only two patients had implant removal following isolated radiographic evidence of metalwork mal position. Conclusions Intra-operative intensifiers reduce the risk of implant and fixation errors. Routine post-operative radiographs altered the management of only 2 out of 700 (0.3%) patients. We suggest that radiographs have no role in routine post-operative care of distal radius fractures, where patients are asymptomatic with appropriate intra-operative intensifier images.

Endonasal Endoscopic Approach to Sphenoid Sinus Lesion

Background: Anatomical position of sphenoid sinus, sellar and parasellar regions are located in the skull base having difficulty to approach due to presence of vital structures in its proximity. The presence of carotid artery and optic nerve in its lateral wall make the situation difficult due to lack of illumination and visual limitation. In the past traditional techniques to approach this region like external ethmoidectomy, transseptal transsphenoidal routes were used causing significant trauma, bleeding and risk of possible complication in skull base region. Aim: to access the efficacy and safety of the endonasal endoscopic approach to the sphenoid sinus Method: This study was done in the department of ENT Shaikh Zayed hospital Lahore, 33 patients who were diagnosed to have lesions involving sphenoid sinus. Detailed history, thorough ENT examination, relative investigations were done and all were managed naso-endoscopically. Results: The review of these cases showed that the endoscopic technique was found to have the advantages of being minimally invasive with no external incisions. There is less trauma to the patient, no need for operating microscope or intraoperative image intensifier. Conclusion: The conclusion of our study showed that naso-endoscopes are excellent tools for better visualization due to availability of different angled scopes and good illumination. The disease is better assessed and cleared identifying landmarks with quicker postoperative recovery and lesser overall morbidity. Over the last few years, endoscopic approach to these regions has gained much popularity because of advances in optics, endoscopes and illumination. Keywords: Endoscopic sinus surgery, sphenoid sinus

Tibial condylar valgus osteotomy (TCVO): Surgical technique and clinical results for knee osteoarthritis with varus deformity

Tibial condylar valgus osteotomy (TCVO) is an intra-articular proximal tibial osteotomy developed in 1989 and has since been used for the treatment of knee osteoarthritis (OA) associated with genu varum. This article describes the surgical technique and clinical results of TCVO. TCVO can be used for all grades of varus knee OA in patients of any age. he preoperative range of movement should be at least 90°. Preoperative screening showed varus-valgus instability due to an intra-articular deformity of the proximal tibia. Using intraoperative image intensification, a sagittally oriented “L”-shaped osteotomy is made from the medial to the tibial tuberosity to the center of the tibial plateau between the medial and lateral tibial spines. The separation of the osteotomy using the lamina spreader is gradually increased using an image intensifier guidance until the articular surface of the lateral tibial plateau comes in contact with the articular surface of the lateral femoral condyle. Adequate correction is indicated by parallelism of the lateral tibial plateau and a line tangential to the distal convexity of the lateral femoral condyle on an anteroposterior (AP) image and the elimination of the valgus instability with the knee in extended position. A “T”-plate (locking or non-locking plate or circular external fixator) is used to fix the osteotomy in the corrected position. Synthetic or autologous bone grafts can be used. We used the Japanese Orthopaedic Association score to evaluate the patient's function and also measured the %MAD, medial plateau opening angle, medial plateau angle, and lateral plateau opening angle on an AP view of the long length roentgenogram of the lower limb (standing position). The JOA score, radiologically measured values, and instability of the knee joint remarkably improved.

A COMPARATIVE STUDY OF SURGICAL AND FUNCTIONAL OUTCOMES IN PATIENTS TREATED WITH INTRAMEDULLARY NAILING AND PLATING FOR MID-SHAFT CLAVICULAR FRACTURES

Introduction: Traditionally, mid-shaft clavicular fractures were treated non-operatively; however, they have been associated with higher non-union rates and poor functional outcomes in certain types of fractures. We aimed to objectively compare the surgical outcomes in patients with mid-shaft clavicular fracture treated either with nailing or plating and assess their functional outcomes over a follow up period of one year.
 Methodology: Our prospective sample was chosen from a pool of patients visiting casualty of our Hospital for fracture clavicle between March 2015 and March 2017. Patients either underwent open reduction and plate fixation with a 3.5 mm superior clavicular plate or a 2.0 mm to 3.5 mm titanium nail. Intraoperative parameters and postoperative functional outcomes over a period of 12 months were compared between the two patient groups. 
 Results: During the study period 65 patients with clavicular fracture were operated in our department, 35 patients with dynamic compression plating and rest intramedullary fixation and nailing. Patients undergoing nailing had a significantly lesser operative time, incision length, blood loss and hospital stay as compared to plating (p value < 0.001). Mean Constant Murley score throughout the follow up period was higher in the group of patients undergoing plating, though the difference was not significant at any follow up point. Nailing was associated with more frequent implant migration and irritation of skin and there was need of significantly more number of intraoperative image intensifier shoots, resulting in higher radiation exposure, as compared to plating. Nailing and plating resulted in mean shortening of clavicle length by 0.5 cm (range 0.4 to 2.1 cm) and 0.2 cm (range 0.2 to 1.8 cm) respectively.
 Conclusions: We found no difference in the functional outcome and nonunion rates between nails and plates fixation for displaced midshaft clavicular fractures but nailing was associated with higher rates of complications.
 Keywords: Clavicle fracture, midshaft, intramedullary fixation, plate fixation, osteosynthesis, trauma

Surgical management of diaphyseal fractures of shaft of humerus by IMIL nailing in adults

Fractures of diaphyseal fracture humerus shaft in adults is itself a great dilemma and becomes more difficult to treat. So in this new era of fast paced technologies, an aggressive approach is required to treat such fractures in view of early rehabilitation and return to occupation. This prospective randomized study was conducted at department of Orthopedics in Jagadguru Jayadeva Murugarajendra medical college Davanagere Karnataka to evaluate outcomes of intramedullary interlocking nail as primary fixation method in diaphyseal fracture shaft of humerus in adults. Surgery duration was less in intramedullary nail because in most of the cases fractures were easily reduced, minimal surgical exposure and associated less closure time. Intra operative image intensifier use was significantly more because of distal screw locking and determination of naillength. Post operatively aim of the treatment was to do early mobilization and early fracture union due to preservation of fracture hematoma. In follow up of cases at 6 week, 3, 6, 12 month as per functional outcomes patients had very mild difficulty in performing activities of daily living. On concluding the outcome as per Rommen et al. Criteria at 23.5 weeks excellent score was found in 76.6% cases of interlocking nail while it was poor in 3.3% cases and remaining had moderate outcomes.

The tansen technique – A new, easy, reliable, safe and cost effective, technique in closed reduction and percutaneous fixation of type 3 supracondylar fracture of the humerus in children

Introduction: Closed reduction and internal fixation with K wires is the standard of care for Gartland type III supracondylar fractures of children since they are too unstable for nonoperative treatment. Occasionally closed reduction of these fractures could be difficult using standard technique warranting open reduction which is associated with additional complications. We report a new intrafocal reduction technique and its results which can be used to reduce difficult supracondylar fractures reliably thus avoiding open reduction and its complications in most instances. Materials and Methods: Consecutive series of twenty-one patients who were treated successfully using intrafocal reduction (Tansen) technique from January 2014 to December 2015 were followed up for minimum of 6 months. Duration of operation, any intraoperative technique-related complication, and number of intraoperative image intensifier images were reviewed. Children were followed up at 3 weeks, 6 weeks, 3 months, and 6 months for the adequacy of reduction, for loss of reduction of fixation and fracture healing as well as a range of motion, complications, and functional outcome using Flynn's criteria. Results: The average operation time was 30.5 ± 10.5 min. The average number of intraoperative images was 15 ± 5. The average time and number of intraoperative images were not affected by the experience of the surgeon. Average healing was 6.1 ± 2 weeks. All patients achieved a satisfactory cosmetic and functional result. There was no significant loss of initial reduction on follow up. The minor complication rate was 16%. There was no technique-specific complication. Conclusion: Our simple intrafocal technique using artery forceps – “Tansen Technique” – gives an acceptable reduction in difficult supracondylar fractures which would otherwise require open reduction. It is cost-effective, consistent, has a short learning curve, and is a safe technique with potential use in day-to-day practice.

Prospective randomized study of outcome of intramedullary interlocking nail as primary fixation method in grade 1 & 2 compound fractures of tibia

Fractures of tibia shaft is itself a great dilemma and becomes more difficult to treat when it becomes a compound fracture. So in this new era of fast paced technologies, an aggressive approach is required to treat such fractures in view of early rehabilitation and return to occupation. This prospective randomized study was conducted at department of Orthopedics in Mahatma Gandhi Medical College and Hospital, Sitapura, Jaipur to evaluate outcomes of intramedullary interlocking nail as primary fixation method in compound fractures of tibia. Surgery duration was less in intramedullary nail because in most of the cases fractures were easily reduced, minimal surgical exposure and associated less closure time. Intra operative image intensifier use was significantly more because of distal screw locking and determination of nail length.Post operatively aim of the treatment was to make the patient upright, and start weight bearing as early as possible as per the personality of fracture. In follow up of cases at 12 and 24 weeks as per functional outcomes patients had very mild difficulty in performing activities of daily living. On concluding the outcome as per Johner and Wruhs Criteria at 24 weeks excellent score was found in 70% cases of ILN while it was poor in 5% cases and remaining had good to fair outcomes.

Tensioned Wire-Assisted Intramedullary Nail Treatment of Proximal Tibia Shaft Fractures: A Technical Trick.

Proximal tibia shaft fractures are often challenging to manage because of their intrinsic tendency toward valgus and apex anterior deformity. In recent years, intramedullary nailing (IMN) has become more frequently used to treat these injuries, allowing for biologic advantages such as load-sharing, immediate weight-bearing, and avoidance of disruption of periosteal blood supply. Several adjunctive techniques, such as semiextended positioning, blocking screws, and external fixation, have been developed to assist with fracture reduction during IMN. We describe a new adjunctive reduction technique-tensioned wire-assisted IMN-for the treatment of proximal tibia shaft fractures. We have found that tensioned wire assistance facilitates fracture reduction during IMN, does not interfere with intraoperative image intensification, and is compatible with both standard nailing instrumentation and additional adjunctive techniques. We present tensioned wire nailing as a technical trick for anatomic and stable reduction of proximal tibia fractures and compare a cohort of proximal tibia shaft fractures managed with and without tensioned wire assistance.

Image intensifier distortion influences a surgeon's ability to aim guidewires during orthopaedic procedures.

Accurate insertion of a guidewire under image intensifier guidance is a fundamental skill required by orthopaedic surgeons. This study investigated how image intensifier distortion, which is composed of pin-cushion and sigmoidal components, changed the apparent trajectory of a guidewire, and the resulting deviation between the intended and actual guidewire tip position. Intraoperative image intensifier images for 220 consecutive patients with hip fractures were retrospectively corrected for distortion using a global polynomial method. The deviation between the intended and actual guidewire tip positions was calculated. Additional distortion parameters were tested using an image intensifier produced by a different manufacturer, and a flat-panel c-arm. Deviation was approximately 1cm if the guidewire was aimed from the extremity of the image and almost 0 if the entry point was only 20% from the centre (p < 0.001). The direction of deviation was different for left and right hips, with average deviations measuring 3mm proximal and 5mm distal respectively (p < 0.001). The flat-panel c-arm almost completely eliminated distortion. Image intensifier distortion significantly altered the intended trajectory of a guidewire, with guidewires aimed from the image periphery more affected than guidewires aimed from the centre. Furthermore, for right hips, guidewires should be aimed distal to their intended position, and for left hips they should be aimed proximal to achieve their desired position. The flat-panel c-arm eliminated the effect of distortion; hence, it may be preferable if precision in guidewire positioning is vital.

Minimally invasive percutaneous plate osteosynthesis of distal femur fractures using a tibial distraction support

Objective To introduce an indirect reduction technique using a modified tibial distraction support in minimally invasive percutaneous plate osteosynthesis (MIPPO) of distal femur fractures and investigate its clinical effect. Methods Between April 2014 and March 2016, 26 distal femur fractures treated with MIPPO technique using a modified tibial distraction-support were reviewed. There were 18 males and 8 females with an average age of (50±10.1) years (25-76 years). Among them, nineteen patients were type A and 7 patients were type C according to AO classification. Operations were performed on an average of (5.6±3.1) d (2-14 d) after the trauma. All the patients were performed indirect reduction with a modified tibial distraction support before using the MIPPO technique. Angular deformity was obtained from preoperative and postoperative for all subjects. In each case, intraoperative image intensification shots to confirm reduction and the operating time were recorded. Functional outcome was evaluated using the Schatzker-Lambert criteria 1 year postoperative. Results All the patients completed closed reduction using the modified tibial distraction support. Preoperative anteroposterior radiographs revealed amean of 8.0°±3.1° (0-16°) angulation in the coronal plane. Lateral radiographs revealed a mean of 16.8°±8.4° (5°-8.6°) angulation in the sagittal plane. Postoperative anteroposterior and lateral radiographs showed a mean angulation of 1.8°±0.6° (0-3.2°) and 2.5°±0.6° (0-3.8°) of varus/valgus and apex posterior angulation, respectively. The mean operating time was (100±11.6) min (80-120 min). No intraoperative or postoperative complications were encountered. Twenty-five patients were followed up and the mean follow up time was (18±3.9) months (12-28 months). There were one delayed union and one non-union. The average time of radiographic evidence of bridging callous was present at (4±0.7) months (3-6 months) in the remained patients. There were 22 excellent patients and 3 good patients according to Schatzker-Lambert criteria one year postoperative. The excellent rate was 100%. Conclusion The modified tibial distraction support is simple and easy to manipulate which is a good option in MIPPO for distal femur fractures and has good clinical effects. Key words: Femoral fractures; Skeletal tracting reposition; Surgical procedures, minimally invasive

Prospective randomized study of outcome of proximal femur nail (PFN) in proximal femur fractures

Proximal Femur fractures are common injuries occurring predominantly as low-energy injuries in the elderly, mostly due to direct injury to hip (e.g. fall). These days intramedullary nails are becoming the implant of choice for unstable proximal femur fractures, as it offer certain distinct advantages in proximal femur fractures. This prospective randomized study was conducted at department of Orthopedics in Mahatma Gandhi Medical College and Hospital, Sitapura, Jaipur to compare outcomes of proximal femur nail. Surgery duration was less in PFN because most of the cases were reduced closed, less exposure was done and associated less closure time. Intra operative image intensifier use was significantly more in PFN group because of requirement of accurate placement of lag screw, distal locking and identification of nail length. Post operatively sole aim of the treatment was to make the patient upright, mobilize as early as possible. In follow up of cases at 16 and 24 weeks as per activity of daily living Patients had very little restriction in Activity of Daily Living. On concluding the outcome as per Salvati-Wilson Score at 24 weeks excellent score was found in 50% cases of PFN while it was fair in 50% cases.

CUSTOMIZED GUIDE FOR FEMORAL COMPONENT POSITIONING IN HIP RESURFACING ARTHROPLASTY.

ABSTRACTObjective: To prove the accuracy of a customized guide developed according to our method. Methods:This customized guide was developed from a three-dimensional model of proximal femur reconstructed using computed tomography data. Based on the new technique, the position of the guide pin insertion was selected and adjusted using the reference of the anatomical femoral neck axis. The customized guide consists of a hemispheric covering designed to fit the posterior part of the femoral neck. The performance of the customized guide was tested in eight patients scheduled for total hip arthroplasty. The stability of the customized guide was assessed by orthopedic surgeons. An intraoperative image intensifier was used to assess the accuracy. Results: The customized guide was stabilized with full contact and was fixed in place in all patients. The mean angular deviations in relation to the what was planned in anteroposterior and lateral hip radiographs were 0.5º ± 1.8º in valgus and 1.0º ± 2.4º in retroversion, respectively. Conclusion: From this pilot test, the authors suggest that the proposed technique could be applied as a customized guide to the positioning device for hip resurfacing arthroplasty with acceptable accuracy and user-friendly interface. Level of Evidence IV, Cases Series.

The Use of Contrast in Caudal Epidural Injections under Image Intensifier Guidance: Is It Necessary?

BackgroundWe investigated the value of using contrast as an additional aid to confirm the accuracy of needle placement for caudal epidural injections under intraoperative image intensifier guidance.MethodsA total of 252 consecutive patients were included in this study. Their mean age was 46.7 years (range, 32 to 76 years). There were 133 males (53%) and 119 females (47%) over a 12-month period.ResultsOf the 252 consecutive procedures, the contrast enhanced image intensifier confirmed accurate needle placement on first attempt in 252 cases (100%). Needle resiting following the infiltration of contrast was required in 0 case.ConclusionsThe results from this study demonstrate that a surgeon beyond the learning curve can accurately place caudal epidural injections using image intensification only, without the use of contrast.

Percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion: a radiological and cadaveric study.

To design and investigate a novel technique of percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion. CT scans of 45 patients were collected and imported into Mimics software for three-dimensional (3D) reconstruction. Cylinders were drawn to simulate the trajectory of the oblique screw. Six measurements were obtained for each unit to design a right size cage: a the distance between the intersection of the simulated trajectory of the screw with the inferior border of the upper vertebra and its anteroinferior corner; b the distance between the intersection of the simulated trajectory of the screw with the superior border of the inferior vertebra and its anterosuperior corner; h the height of the intervertebral space; θ the angle between simulated trajectory of screw and the upper endplate of inferior vertebra; uw: the width of the inferior endplate of upper vertebra; iw: the width of upper endplate of inferior vertebra. Three intact adult fresh-frozen cadaveric specimens were obtained, percutaneous posterior transdiscal oblique screw fixation was performed under X-ray apparatus, and interbody cage was implanted by assistance with special self-retaining retractor system and endoscope. According to the results of data measured from 3D images, trapezoid shape interbody cages with suitable size were designed. Percutaneous posterior oblique screw fixation with lateral interbody fusion was performed on three cadaveric specimens successfully. Using specially designed trapezoid shape interbody cages, assisted by intra-operative image intensification and endoscope, it is feasible to perform percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion technique.