Die postoperative Kontroll-CT nach Acetabulumfraktur

Iatrogenic Venous Compression Syndrome Following Bilateral Hip Arthroplasty: A Unique Case of Bilateral Femoral Vein Compression in a Patient With May-Thurner Syndrome

Iatrogenic venous compression syndrome is defined by extrinsic vein compression due to medical hardware, particularly relevant after joint replacement surgeries. Inserting medical hardware can lead to immediate risks such as deep vein thrombosis and pulmonary embolisms due to local tissue inflammation. The long-term issues include venous insufficiency due to chronic vessel irritation, subsequently causing intimal proliferation and thickening. Despite the existing knowledge of venous compression syndromes, iatrogenic cases are severely underreported. Here, we present a unique case of bilateral common femoral vein compression in a patient with May-Thurner syndrome and prior bilateral hip arthroplasty. An 85-year-old man with a history of venous insufficiency and bilateral hip arthroplasty for osteoarthritis presented with bilateral leg edema. Unsuccessful sclerotherapy and radiofrequency ablation led to a referral to a vascular specialist for venous duplex scans, venograms, and intravascular ultrasound. May-Thurner syndrome was revealed in the left common iliac vein, prompting the deployment of an 18 mm × 16 mm stent. Subsequently, during a venogram, what initially appeared to be a vasospasm in the left common femoral vein was diagnosed as extrinsic iatrogenic venous compression due to acetabular hip screws. This was found after two IV injections of 400 mg nitrogen and one balloon angioplasty could not resolve the compression. After advancement over a 0.35" microwire and accurate positioning over the center of the left common femoral vein lesion, a 16 mm × 90 mm stent was deployed. The venogram and intravascular ultrasound also showed a similar compression in the right common femoral vein. Another 400 mg IV nitrogen did not expand the lesion, so it was concluded that there was similarly an iatrogenic venous compression of the right common femoral vein, also due to acetabular hip screws in the right femur. A follow-up was scheduled a couple of weeks later to address the issue in the right common femoral vein. The underreported issue of iatrogenic venous compression following joint replacements highlights the need for better recognition and management of vascular complications due to inflammation and intimal proliferation. This is especially the case in high-risk patients, such as those with May-Thurner syndrome.

Periarticular screws: what's in and what's out of the joint?

Periarticular hardware placement can be challenging and a source of angst for orthopaedic surgeons due to fear of penetrating the articular surface and causing undue harm to the joint. In recent years, many surgeons have turned to computed tomography (CT) and other intraoperative or postoperative modalities to determine whether hardware is truly extraarticular in areas of complex anatomy. Yet, these adjuncts are expensive, time consuming, and often unnecessary given the advancement in understanding of intraoperative fluoroscopy. We present a review article with the goal of empowering surgeons to leave the operating room, with fluoroscopy alone, assured that all hardware is beneath the articular surface that is being worked on. By understanding a simple concept, surgeons can extrapolate the information in this article to any joint and bony surface in the body. While targeted at both residents and surgeons who may not have completed a trauma fellowship, this review can benefit all orthopaedic surgeons alike.

The accuracy of gap and step-off measurements in acetabular fracture treatment

The assessment of gaps and steps in acetabular fractures is challenging. Data from various imaging techniques to enable accurate quantification of acetabular fracture displacement are limited. The aim of this study was to assess the accuracy of pelvic radiographs, intraoperative fluoroscopy, and computed tomography (CT) in detecting gaps and step-offs in acetabular fractures. Sixty patients, surgically treated for acetabular fractures, were included. Five observers (5400 measurements) measured the gaps and step-offs on radiographs and CT scans. Intraoperative fluoroscopy images were reassessed for the presence of gaps and/or step-offs. Preoperatively, 25% of the gaps and 40% of the step-offs were undetected on radiographs compared to CT. Postoperatively, 52% of the gaps and 80% of the step-offs were missed on radiographs compared to CT. Radiograph analysis led to a significantly smaller gap and step-off compared to the CT measurements, an underestimation by a factor of two. Approximately 70% of the residual gaps and step-offs was not detected using intraoperative fluoroscopy. Gaps and step-offs that exceed the critical cut-off indicating worse prognosis often remained undetected on radiographs compared to CT scans. Less-experienced observers tend to overestimate gaps and step-offs compared to the more-experienced observers. In acetabular fracture treatment, gaps and step-offs were often undetected and underestimated on radiographs and intraoperative fluoroscopy in comparison with CT scans. This means that CT is superior to radiographs in detecting acetabular fracture displacement, which is clinically relevant for patient counselling regarding treatment decisions and prognosis.

Outcomes of Surgical Management of Acetabular Fractures Treated with Anterior Approaches

Objective

In this study we aimed to evaluate the outcomes of anterior and combined approaches for treatment of acetabular fractures.

Materials and Methods

Thirty-seven acetabular fractures in 35 patients treated with an anterior approach were evaluated retrospectively. Fractures were classified according to Judet-Letournel. Early and final radiological evaluation was based on Matta's criteria. Modified Merle d'Aubigne and Postel criteria were used for functional assessment.

Results

Eleven (30%) fractures were simple type and 26 (70%) were mixed type. Two (18%) of the simple fractures were transverse and 9(82%) were anterior column fractures. Fourteen (54%) of the mixed type fractures were both column fractures, 5 (19%) were transverse+posterior wall, 5 (19%) were T shaped and 2 (8%) were anterior column+posterior hemitransverse fractures. Surgical approach was ilioinguinal in 15 (43%) patients, Stoppa in 9 (26%) and combined11 (31%). Our functional outcomes were perfect in 10 (27%) hips, good in 20 (54%), moderate in 4 (10%) and poor in 3 (8%). Our radiological results were perfect in 15 (40.5%) hips, good in 15 (40.5%), moderate in 4 (11%) and poor in 3 (8%).

Conclusion

Anterior surgical approaches provide satisfactory outcomes in appropriate fracture types. Posterior approach can be combined in certain fracture types. We think that rate of the requirement for a concomitant posterior approach for certain fractures of the acetabulum will decrease as experience increases.

Arthroscopic Management of Intraarticular Screw Perforation after Surgical Treatment of an Acetabular Posterior Wall Fracture: A Case Report

Although surgical techniques for treating acetabular fracture are evolving, the use of periacetabular screws is common, and their placement in acetabular surgery is still technically demanding. For instance, intraarticular screw perforation is a serious complication that may occur during surgical treatment of an acetabular fracture. Here, we describe the case of a 50-year-old female who experienced an intraarticular screw perforation after surgical treatment of a posterior acetabular wall fracture. Removal of the perforated screw was performed arthroscopically based on its ability to offer minimally invasive access to the hip joint. One year after removal of the screw, no radiological signs of osteoarthritic changes were observed. The patient regained normal ambulation without limitations to range of motion or hip pain. To our knowledge, this is the first report on the use of arthroscopy to treat intraarticular screw perforation after surgical treatment of an acetabular fracture.

Insertion of psoas minor tendon at pelvic brim, a novel anatomic landmark for extra-articular, screw placement through Stoppa approach

BACKGROUND

The psoas minor partially inserted to the superior pelvic brim. And the plate used to fix the acetabular fracture has always been positioned at the pelvic brim after reduction through the Stoppa approach. However, there are few studies depicting the clinical significance of the psoas minor. The purpose of this paper was to explore the relationship between the insertion of the psoas minor tendon at the pelvic brim (IPMTPB) and screw placement through the Stoppa approach.

MATERIALS AND METHODS

Fifteen cadavers were dissected for adequate exposure to IPMTPB in our study. However, not all specimens had a psoas minor. For the specimens with IPMTPB, the posterior and anterior edges were used as the first and second entry points, dividing the area from the sacroiliac joint to the pubic symphysis into three zones (d1, d2 and d3). The average proportion of each zone was obtained after measurement the three zones, to locate the two entry points for the specimens without a psoas minor. From the longitudinal Stoppa incision, the first wire was inserted horizontally, and the second wire was placed vertical to the bone surface. Fluoroscopy and computed tomography (CT) were conducted to examine the relationship between the wires and the acetabulum.

RESULTS

There was a psoas minor in sixteen hemipelvises (53.33%). After measurement and calculation, we determined that the average proportions of zones d1, d2, and d3 were 28.03%, 29.14%, and 42.83%, respectively. For all specimens, the wires were successfully inserted, and the trajectories of the wires were outside the hip joint cavity.

CONCLUSIONS

IPMTPB could be used as an anatomic landmark of safe zones for screw placement through the Stoppa approach. For cases without a psoas minor, the zones for extra-articular screw placement could be determined through the measurements in this paper.

Utility of intraoperative three-dimensional imaging at the hip and knee joints with and without navigation

Intraoperative three-dimensional imaging in orthopaedic trauma care has achieved greater importance over the last few years in some specialized hospital centers. For various types of peripheral-extremity trauma, clinical studies have confirmed, on the basis of three-dimensional information, an intraoperative revision rate ranging from 7% to 19%. Three-dimensional C-arm imaging may be used to achieve adequate intraoperative information about the quality of fracture reduction, residual steps, and correct implant placement, and this technique has been described for use in both the hip joint (for acetabular fractures, isolated femoral head [Pipkin-type] fractures, three-dimensional navigated sacroiliac screw or acetabular column screw placements, and, less frequently, for navigated drilling of tumors or osteochondral lesions) and the knee joint (for tibial plateau fractures, complex distal femoral condylar fractures, and navigated targeting of osteochondral lesions in combination with the use of preoperative magnetic resonance imaging scans). Major limitations of this technology include increased intraoperative time requirements, limited image quality compared with that of computed tomographic scans, cost, specific positioning techniques, and the need for radiolucent operating-room tables. Although prospective studies have yet to be conducted, the ways in which the surgeon will benefit from the use of intraoperative three-dimensional imaging are apparent, but indications for combined three-dimensional C-arm navigated procedures at the hip and knee joint are still limited. Future directions may include the use of digital flat-panel detectors and even robotic-controlled C-arm motion.

Improved intra-operative reduction control using a three-dimensional mobile image intensifier - a proximal tibia cadaver study

This study aimed to analyse whether the precision of a three-dimensional mobile image intensifier (ISO-C 3D) differs from conventional two-dimensional fluoroscopy and high resolution CT scan in a fracture model of the proximal tibia. A depression fracture of the medial plateau (AO/OTA 41-B2.3) was created in 12 formalin-fixed, human cadaver knees. The cartilage of the depression could be positioned above (+1mm, +2mm), below (-1mm, -2mm), or in line with the joint surface. Fluoroscopy, computed tomography (CT) scans, and ISO-C 3D scans (four different protocols: 100 images, 66 images, 50 images, and 33 images) were done for each fracture level. Three independent observers assessed each imaging set. The difference between the estimated reduction and the real reduction was used for statistical analysis. Our hypothesis was that no differences in the precision exist between the imaging techniques (p<0.05). The conventional image intensifier group (0.7 mm+/-0.67) showed significantly higher deviations than the CT group (0.3 mm+/-0.43; p<0.001) and significantly higher deviations than all ISO-C 3D groups (0.4-0.5 mm; p<0.001). Of the ISO-C 3D groups, only the scan protocol with the lowest number of images (0.5 mm+/-0.51) showed significantly lower precision than the CT group (p<0.001). It was concluded that the three-dimensional mobile image intensifier showed higher precision in reduction assessment in a fracture model of the tibial plateau compared to fluoroscopy. High resolution CT scans should remain the standard for post-operative assessment of reduction outside the operating theatre.

Value of 3D fluoroscopic imaging of acetabular fractures comparison to 2D fluoroscopy and CT imaging

PURPOSE

Intraoperative two-dimensional (2D) fluoroscopy of acetabular fractures is difficult due to the complex three-dimensional (3D) anatomy. Intraoperative 3D fluoroscopy may have particular utility in the evaluation of acetabular fractures. We compared the accuracy of 3D fluoroscopic imaging in evaluating acetabular fracture displacement and implant placement with fluoroscopy and computed tomography (CT) scans.

METHODS

In 24 cadaveric acetabuli, a transverse acetabular fracture was created. First a 2 mm step-off of the articular surface was created and reconstruction plates placed on the anterior and posterior columns. In 12 specimens, two screws were placed intraarticularly, protruded by 2 mm. In the remaining 12 specimens, the same constructs were used but the screws remained extraarticular. Second tests were designed to simulate an impaction injury. After hardware removal, a hollow trephine (diameter of 14.9 mm) was used to core a bone cylinder on the dome of the acetabulum, and impacted until it was recessed into the articular surface by 2 mm. Plates were placed, and screws were placed intraarticularly in 12 specimens, as in the first set of tests. All cadavers were imaged with standard 2D-, 3D fluoroscopy and CT. Three observers randomly evaluated all imaging studies for all specimens.

RESULTS

For detection of intraarticular screws, both the Iso-C3D and the CT scans were significantly more sensitive (96 and 96%, respectively) and specific (96 and 100%, respectively) in detecting the intraarticular position compared to 2D fluoroscopy (75%; P < 0.05). Sensitivity of articular step-off detection was no different between the Iso-C3D (83%), CT (79%), and 2D fluoroscopy (87%). Articular impaction was correctly identified in 79% of specimens with the Iso-C 3 D technique, while the CT was accurate in 92%. 2D fluoroscopy was accurate in 62% for the impactions (P < 0.05 vs. CT).

CONCLUSIONS

3D-fluoroscopic imaging appears to be extremely accurate in evaluating acetabular fracture constructs. Its sensitivity and specificity for evaluating intraoperative hardware was greater than with 2D fluoroscopy and equivalent to CT scan. Volumetric impactions were also reliably demonstrated on both of the 3D modalities, which were both superior to 2D fluoroscopy. Overall, Iso-C3D multiplanar imaging yields information regarding implant placement and articular reduction that is more detailed and accurate than standard fluoroscopy and is comparable to CT.