Absence Of Dislocation Research Articles

Risk Factors for Iliopsoas Tendinopathy After Anterior Approach Total Hip Arthroplasty

BackgroundIliopsoas tendinopathy is a cause of groin pain following total hip arthroplasty (THA). With the anterior approach becoming increasingly popular, our aim was to determine the prevalence of iliopsoas tendinopathy following anterior approach THA, to identify risk factors and to determine an influence on patient-reported outcomes. MethodsThis is a retrospective case-control study of prospectively recorded data on 2,120 primary anterior approach THA (1,815 patients). The diagnosis of iliopsoas tendinopathy was based on (1) persistent postoperative groin pain, triggered by hip flexion; (2) absence of dislocation, infection, loosening, or fracture; and (3) decrease of pain after fluoroscopy-guided iliopsoas tendon sheet injection with xylocaine and corticosteroid. Outcomes included hip reconstruction (inclination/anteversion and leg-length), complication rates, reoperation rates, and patient-reported outcomes including Hip disability and Osteoarthritis Outcome Score. ResultsForty four patients (46 THAs) (2.2%) were diagnosed with iliopsoas tendinopathy. They were younger than patients who did not have iliopsoas tendinopathy (51 years [range, 27-76] versus 62 years [range, 20-90]; P < .001). Logistic regression analyses demonstrated that younger age (P < .001) and presence of a spine fusion (P = .008) (odds ratio 4.6) were the significant predictors of iliopsoas tendinopathy. These patients had lower Hip disability and Osteoarthritis Outcome scores, reported more often low back pain (odds ratio 4.8), and greater trochanter pain (odds ratio 5.4). ConclusionWe found an incidence of 2.2% of iliopsoas tendinopathy patients after anterior approach THA that compromised outcomes. Younger age and previous spine fusion were identified as most important risk factors. These patients were 5 times more likely to report low back pain and greater trochanter pain post-THA.

Dual Mobility Cups as the Routine Choice in Total Hip Arthroplasty.

Background and Objectives: Total hip arthroplasty (THA) is considered the most successful surgical procedure in orthopedics. However, dislocation remains the main indication for surgical revision. New designs of dual mobility cups (DMC) have lowered the classical complications and have extended the indications of DMC in elective surgeries. Our aim is to assess the trend of DMC indications in THA as well as the incidence of their dislocation. Materials and Methods: We retrospectively reviewed all patients undergoing THA with DMC during the years 2015 and 2021. The original indication for DMC included patients sustaining neck of femur fractures (NOF#) and associated risk factors for dislocations. Five years later, DMC was considered our standard of care in total hip arthroplasty. The approach (anterolateral or posterolateral) was chosen by the surgeon according to his/her preferences, as was the implant. Data collected included patients’ demographics, diagnosis, admission time, surgical approach, cup models, and inclination and complications. Patients sustaining a hip dislocation were prospectively reviewed and assessed for treatment received, new dislocations, and need for surgical revision. Two groups were created for the analysis according to the presence or absence of dislocation during follow-up. Results: In the analysis, 531 arthroplasties were included (mean age 72.2 years) with a mean follow-up of 2.86 years. The trend of indications for DMC increased from 16% of THA in 2015 to 78% of THA in 2021. We found a total of 8 dislocations (1.5%), none of them associated with elective surgery. Closed reduction was unsatisfactory in four cases (50%). There was one case of intraprosthetic dislocation. Dislocations were associated to smaller heads (22 mm) (1.5% vs. 25%, p = 0.008) and cups (51.2 mm vs. 48.7 mm, p = 0.038) and posterior approach (62.5% vs. 37.5%, p = 0.011). Conclusion: Dual mobility cups are a great option to reduce the risk of dislocation after a THA both in the neck of femur fractures and elective cases. The use of an anterolateral approach in THA after a neck or femur fracture might considerably decrease the risk of dislocation.

Associated Injuries Are Frequent and Severe Among Geriatric Patients With Zygomatico-Orbital Fractures

Associated injuries (AIs) are hypothesized to be frequent in geriatric zygomatico-orbital (ZMO) fractures. The study aim was to determine the relation between ZMO fractures and AIs in geriatric patients compared with younger adult patients. A retrospective case-and-control study was carried out on geriatric patients at least 65years of age (n=93) and younger adult patients 20 to 30years of age (n=68) diagnosed with pure unilateral ZMO fractures. The main exposure was age, the primary outcome was AI outside the face, and the secondary outcomes were type and severity of AI, ocular injuries, restriction of mandibular movement, and ZMO buttress asymmetry. The confounding variables were gender, trauma mechanism, type of ZMO fracture, and dislocation. Statistical analyses included χ2 tests, risk evaluation with 2×2 tables, and logistic regression analysis. AIs outside the face, and particularly brain injuries, were significantly more frequent in the geriatric group than in the control group (P<.001). The significant predictors of AIs outside the face were fall from a height (66.7%), motor vehicle accidents (66.7%), and absence of ZMO dislocation (59.5%; P<.001). The adjusted risk of brain injury was 2.5-fold in the absence of dislocation. The geriatric group had a more than 5-fold higher risk of brain injuries compared with the younger control group (P=.003). AIs in general, and particularly brain injuries, are frequent in geriatric ZMO fractures. Intracranial injuries should be ruled out, particularly in geriatric patients diagnosed with a non-dislocated ZMO fracture.

172 Musculoskeletal Ultrasound to Diagnosis Dislocated Shoulders Study

Shoulder dislocations are common, and most practitioners order pre- and post-reduction plain films. There is evidence that point-of-care shoulder ultrasound (SUS) accurately diagnoses shoulder dislocations and humeral fractures. We determined the accuracy and timeliness of a point-of-care SUS from a posterior approach to detect shoulder dislocations and fractures compared with plain radiography. We performed a multi-center, prospective, observational study at 2 academic EDs with fellowship-trained ED ultrasonographers. We included all adult patients presenting to the ED for suspected shoulder dislocation or humerus fracture. The SUS was performed from a posterior approach by an ultrasound-trained physician with a curvilinear or high-frequency linear transducer in the transverse plane. Probe choice was at the discretion of the sonographer. Presence or absence of dislocation was determined by measuring the displacement of the humeral head either anteriorly or posteriorly relative to the glenoid rim. Plain radiographs served as the criterion standard and were interpreted by board-certified radiologists blinded to SUS results. We compared continuous variables between radiographs and SUS using paired t-tests. ROC analysis with Youden’s Index was used to identify displacement cutoffs for diagnosing dislocations. Of 37 subjects enrolled, 21 (57%) were male, 11 (30%) had a history of shoulder dislocation, and 18 (49%) sustained injuries from ground level falls. We excluded 2 subjects who declined radiography. Of 35 included patients, 23 (66%) had shoulder dislocations on radiography and of these, 21 (91%) were correctly diagnosed by SUS. Compared to the criterion standard, SUS had 91% sensitivity (95% CI 70-98%), 100% specificity (70-100%), 100% positive predictive value (PPV) (81-100%), and 86% negative predictive value (NPV) (56-97%). All 12 of 35 patients (34%) without dislocations were correctly identified by SUS. Thirteen of 35 subjects (37%) had fractures, of which 7 (54%) were detected by SUS, and all 22 (63%) without fractures were correctly ruled-out. Five of 6 missed fractures were Hill-Sachs deformities. For detecting fractures as compared to radiography, SUS had a 54% sensitivity (26-80%), 100% specificity (82-100%), 100% PPV (56-100%), and 79% NPV (59-91%). The optimal cut point for displacement distance was 0.875, resulting in 89% sensitivity (64-98%), 100% specificity (68-100%), 100% PPV (76-100%), and 85% NPV (54-97%). The mean time from triage to SUS was 62 minutes versus 100 minutes for radiography (p < 0.001). Sonographers’ confidence in their SUS diagnosis was high. SUS from the posterior approach is a highly accurate method to diagnose shoulder dislocations and humeral fractures. It can be performed faster than radiographs, and sonographers have high confidence levels in their diagnoses. All missed fractures were clinically insignificant, and all patients without dislocations and fractures were correctly identified. SUS should be considered as a routine diagnostic tool for the detection of shoulder dislocation in the ED.

Classifications in Brief: Regan-Morrey Classification of Coronoid Fractures.

Classifications in Brief: Regan-Morrey Classification of Coronoid Fractures.

Oriented ordering near line defects in crystals

General properties of directed ordering near line defects, in particular an edge dislocation, in elastic crystals undergoing phase transition are studied using the two-component time-dependent Ginzburg–Landau equation in two dimensions or 2D-XY model. The associated Landau potential comprises a sixth-order term, cubic anisotropy terms and the field of the dislocation. In thermodynamic equilibrium, the phase diagram for the model is delineated. Upon quenching the system below its transition point, the temporal evolution of the order parameter components in the vicinity of the defect is numerically evaluated. The development of vortices, emanated from the model, is explored and their interaction with the dislocation is examined. The dislocation produced a vortex free circular region whose diameter grew almost linearly with time. The time-dependence of vortex density for various settings of the Landau potential coefficients are evaluated. The vortex density (in 2D) decreased inversely with time, albeit faster in the absence of dislocation. By computing the two-point correlation function, we established that the dynamic scaling law is satisfied for the considered model if the distance is scaled by or by its half-width for a dislocation free crystal. Finally, phase transitions in improper ferroelectrics in the context of the model are discussed.

Evora® chromium–cobalt dual mobility socket: Results at a minimum 10 years’ follow-up

The Evora chromium-cobalt alloy dual mobility socket claims to display a large articulation tribology different from that of stainless steel models, limiting the risk of intraprosthetic dislocation and wear. The present study reports a minimum of 10years' follow-up in a multicenter prospective series of 200 sockets previously reported on at 5years. The use of chromium-cobalt in dual mobility sockets provides a low rate of failure at 10years, especially as regards to osteolysis and intraprosthetic dislocation. Two hundred hydroxyapatite-coated molded chromium-cobalt sockets without titanium interface were implanted without cement in 194 patients with a mean age of 70 years (range, 32-91 years). Clinical results were assessed on Postel Merle d'Aubigné and Harris scores, plain radiographs and survival analysis. At a mean 11 years' follow-up (10-13 years), 56 patients had died and 31 were lost to follow-up. Four underwent surgical revision (3 femoral components, and 1 socket for migration at 9 years with complete disappearance of the hydroxyapatite). A total of 109 implants were analyzable in 107 patients with a mean age of 81 years (55-93 years). At follow-up, the mean Harris score was 90 (75-96) and the PMA score 16.3 (14-18). There were no cases of loosening (except for the case reoperated on at 9 years) and no acetabular radiolucency or cysts. There were 2 cases of non-evolutive femoral radiolucency and 10 of femoral granuloma, involving head size > 22 mm (P<0.0001) and a cemented titanium stem (P=0.004) as risk factors. There were no dislocations in the large or small articulation. Ten-year survival was 99% (95% CI: 97.3%-100%) with socket revision as censorship criterion. The absence of dislocation in both small and large articulations confirmed the efficacy of the dual mobility concept and suggested an advantage for chromium-cobalt sockets in reducing the rate of intraprosthetic dislocation and preventing blockage of the large articulation by a better performance in the friction couple. Granulomas were associated with wear in cemented titanium stems and with heads greater than 22 mm in diameter. Ten-year survival was 99% (censorship criterion: revision for socket failure); there was, however, one case of socket loosening with disappearance of the hydroxyapatite, indicating that surveillance should be continued in this cohort.

Transformation induced toughening and flaw tolerance in pure nanocrystalline aluminum

Pure bulk metals do not exhibit solid–solid phase transformation since they deform and fail far below the required stress levels for phase transformation, which exceeds hundreds of GPa. We propose that for certain grain size, thickness and notch geometry, classical deformation modes can be suppressed to induce phase transformation in pure metal films at stresses few orders of magnitude lower than the theoretical values. For the first time, we present in situ transmission electron diffraction evidence of face-centered cubic (FCC) to hexagonal ω phase transformation in 99.99% pure nanocrystalline aluminum at room temperature and only 2.5GPa of tensile stress. For 60nm average grain size, the aluminum films did not show any appreciable diffusion-based processes such as grain growth, rotation and sliding. At the same time, the 200nm thick specimens are thin enough for the dislocations to escape through the surface. With no active dislocation sources, in situ microscopy did not show any dislocation-based deformation either. Facilitated by the absence of dislocation and diffusion based processes, the uniaxial nature of specimen loading results in phase transformation at stresses two orders of magnitude lower than that predicted for aluminum. We also propose that phase transformation can result in a flaw tolerance in the material.

Displaced medial epicondyle fractures of the humerus: surgical treatment and results. A report of 139 cases

Elbow instability is a common feature after medial epicondyle fractures, displaced or not, even in the absence of dislocation. Undisplaced or minimally displaced fractures often have an underestimated degree of instability secondary to unrecognised capsuloligamentous and muscular injuries. The purpose of this retrospective study was to analyze and to assess objectively the results of the surgical treatment of these acute injuries. One hundred and thirty-nine displaced medial epicondyle fractures were surgically treated and reviewed. A valgus stress test was performed on each child under general anesthesia or sedation. Functional outcome was assessed using a scoring system based on a series of clinical and radiographic criteria. The mean age of patients at the time of accident was 11.9 years. Mean follow-up was 3.9 years. All fractures had associated with instability of the elbow. A posterolateral elbow dislocation was associated in 80 fractures. The medial epicondylar fragment was anatomically reduced and fixed in all cases. The final result was excellent in 130 cases and good in 9 cases. Elbow were stable and pain free in all patients. Normal elbow range of motion was reported in 133 cases. Union was achieved in all cases. Among these cases, nine had presented a <<fibrous>> union with no change on valgus stress views. No cases of cubitus valgus >/=10 degrees were observed. Anatomical abnormalities of the elbow were present in 28 cases: periarticular calcification in 18 cases, medial condyle groove formation in 4 cases, moderate hypertrophy and fragmentation of the medial epicondyle, respectively, in 3 cases. The positive valgus stress test performed at the time of surgery for all epicondyle fractures without associated dislocation regardless of there degree of displacement justified our operative approach. Operative intervention is a good management of these fractures and results in an anatomic reduction, a solid bone union and prevents valgus instability. Even with postoperative immobilization of the elbow (mean of 4 weeks), stiffness is rare. Damage to the medial stabilizing structure of the elbow rather than the extent of medial epicondyle displacement has a far greater influence on joint stability and outcome.

Complete Cervical Intervertebral Disc Extrusion with Spinal Cord Injury in the Absence of Facet Dislocation

Complete cervical disc complex extrusion, defined as the extrusion of both cartilaginous end-plates, the entire nucleus pulposus, and portions of the anulus fibrosus, is rare. A case of complete cervical disc complex extrusion with spinal cord injury in the absence of facet dislocation or subluxation in an obtunded patient is reported. To report an unusual presentation of spinal cord injury and the occurrence of complete traumatic cervical disc complex extrusion in the absence of facet dislocation and normal plain radiographic findings. Traumatic cervical disc herniation occurs in 54% to 80% of patients with facet dislocation. A report of complete extrusion of a cervical intervertebral disc complex (cartilaginous endplate, anulus, and nucleus pulposus) with spinal cord injury in the absence of dislocation has not been described, to the best of the authors' knowledge. A clinical and radiographic review of such a case of complete traumatic cervical disc complex herniation in the absence of dislocation was performed. Plain radiographic imaging did not show any injury. A nondisplaced fracture of the left inferior facet joint was evident on computed tomography. The diagnosis of C4-C5 intervertebral disc extrusion was made only after magnetic resonance imaging. The vacuum effect of complete disc extrusion created a "white-out" appearance to the disc space on the sagittal T2 magnetic resonance image. The patient underwent anterior cervical discectomy and fusion with additional posterior cervical fusion. He subsequently regained functional strength against gravity in two of four limbs. He remains completely paraparetic in the left upper extremity and partially paraparetic in the left lower extremity. The case report highlights the occurrence of complete traumatic cervical disc extrusion in the absence of facet dislocation with normal plain radiographic findings and consequent spinal cord injury, which can accompany such an injury.

The microscopic pathoanatomy of acute anterior shoulder dislocations in a simian model

Purpose: The purpose of this study was to determine the extent of capsular injury that occurs at a microscopic level in association with acute anterior shoulder dislocations. Type of Study: The study was an anatomic, cadaveric study using a simian model. The microscopic slide review was blinded regarding the presence or absence of dislocation. Methods: Three cadaveric monkey shoulder specimens were dissected free of muscle tissue but left undislocated as controls. Eleven cadaveric monkey shoulder specimens were dislocated with an abduction and external rotation force and subsequently evaluated grossly and histologically for the presence and direction of gross and microscopic injury. Results: All dislocated specimens had an associated Bankart lesion. In addition, all dislocated specimens had histologic evidence of capsular microtearing. The tears were in no specific location or direction and were at times located perpendicular to, obliquely to, or between the longitudinal orientation of the fibers. Conclusions: Based on this model, a Bankart lesion is a common and usual occurrence with acute anterior shoulder dislocations. In these specimens, the Bankart lesion was never an isolated pathology. Microscopic capsular injury was always associated. Additionally, the direction of the capsular injury is highly variable.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 6 (July-August), 2002: pp 618–623

Ｈａｒｒｉｓ／Ｇａｌａｎｔｅ型セメントレスＴＨＡ術後脱臼症例の検討

From 1987 to 1993, 76 primary total hip arthroplasties (THA) with cementless porous-coated hip prostheses were performed in our hospital.Of these, dislocation after THA occurred in only 4 hips (5.3%).Many reports show that the factors which seem to influence dislocation after THA are acetabular cup position, femoral neck length, head size and position of the femoral head.We investigated the relationship between these factors and dislocation after THA.There was no significant difference between the presence or absence of dislocation after THA and these factors.This study suggested that the factors that were most likely to influence dislocation after THA were acetabular cup malposition and soft tissue weakness or imbalance.

Expandable biliary metal stents for malignancies: endoscopic insertion and diathermic cleaning for tumor ingrowth

Seventeen patients with malignant biliary strictures have been treated by endoscopic insertion of self-expandable metallic prostheses. Two patients received two prostheses inserted simultaneously in both the left and right hepatic ducts for Klatskin tumor type III. Immediate results were satisfactory despite an operative mortality of 18%, and neither early nor late clogging was observed even in patients who presented previously with sludge above plastic stents that were removed. However, among five patients followed for more than 4 months, two presented with obstruction due to tumor ingrowth into the stent through the metallic mesh. Accordingly, initial enthusiasm concerning long-term patency of these stents has decreased. However, we describe a technique of "diathermic cleaning" of tumor ingrowth which can easily restore the stent patency. The advantages of these wire mesh 30 F stents are their easier insertion, better immediate drainage, and absence of dislocation or perforation.