Lateral Dislocation Research Articles

Distalization of the Tibial Tubercle for Patellar Stabilization Combined With Medial Patellofemoral Ligament Reconstruction: Length of Distalization or Residual Patella Alta and its Affect on Outcome

Background: Previous research supports that distal translation of the tibial tubercle osteotomy (dTTO) for patients with recurrent lateral patellar dislocation (R-LPD) and patella alta is effective for surgical patellar stabilization. Hypothesis/Purpose: The main purpose of this article is to evaluate (1) the results of modifying the surgical threshold and postoperative goal of patellar height measurements for surgical stabilization originated in the “menu à la carte” approach to patellar surgical stabilization and (2) the relationship between the distance distalized in millimeters and postoperative complications. Our hypothesis was that dTTO with medial patellofemoral ligament reconstruction (MPFL-R) will successfully stabilize the patella with improvement in outcome scores and few complications, using a modification of the original menu à la carte as our surgical algorithm. Study Design: Case series; Level of evidence, 4. Methods: A total of 68 consecutive patients with R-LPD underwent dTTO and MPFL-R for surgical patellar stabilization by a single surgeon between May 2009 and September 2015. Surgical indications were R-LPD combined with patella alta. The surgical threshold for dTTO was Caton-Deschamps index (CDI) or Insall-Salvati ratio ≥1.4 and/or a patellar trochlear index <0.15. The postoperative surgical goal for patellar height was a CDI of 1.1 to 1.2. Length of the distalization was computed by using the CDI measurement as the primary intraoperative guide and measured intraoperatively with a ruler. Clinical, radiographic, and patient outcome measures were reviewed. Results: The mean CDI preoperatively was 1.40 and postoperatively it was 1.09. The mean distalization was 9.9 mm (range, 4-15 mm). Three patients (4.4%) had frank R-LPD postoperatively. Ten patients had residual patella alta (CDI >1.2), with 1 redislocation. Mean postoperative CDI in the recurrent dislocation group was 1.13 (range, 1.06-1.25) as compared with 1.09 (range, 0.92-1.35) in the nonrecurrent group (P = 0.65). Complications included 3 tibial fractures (4.4%) and postoperative knee arthrofibrosis in 6 patients (8.8%), with mean distalization greater in the arthrofibrosis group (P = .04). Knee injury and Osteoarthritis Outcome Score (KOOS) values improved in all domains, including a 31–point increase in Quality of Life. Conclusion: dTTO with MPFL-R for patients with patella alta leads to a high rate of normalization of patellar height measurements (87%) and patellar stabilization (95.6%). Residual patella alta is not associated with an increased risk of recurrence. The length of dTTO up to 15 mm is not associated with an increase in postoperative complications, except for an increased prevalence of arthrofibrosis (8.8%).

Isolated medial patellofemoral ligament reconstruction is valid to stabilize patellofemoral joint but uncertain to reduce patellar height in setting of lateral patellar dislocation and patella alta.

Medial patellofemoral ligament reconstruction (MPFLR) is the most commonly used surgical treatment for patients with lateral patellar dislocation (LPD). It is still poorly understood whether or not MPFLR has a contributory effect on decreasing patellar height. Forty-five patients who underwent isolated MPFLR for LPD and patella alta were evaluated with a mean follow-up period of 24months (22-25months). Knee joint functionswere evaluated by Banff patellofemoral instability instrument (BPII) 2.0 scores and Kujala scores. Patellofemoral engagement and stability were assessed by the patella tilt angle (PTA) and patellar congruence angle (PCA) measured by CT scans, and the patellar-glide test. Patellar height was calculated on lateral radiographs according to three methods: Caton-Deschamps ratios (CDR), Insall-Salvati ratios (ISR), and Blackburne-Peel ratios (BPR). A threshold value of p < 0.05 denoted a statistically significant difference. Significant improvements were found in both BPII 2.0 scores, which increased from 41.7 to 77.8 (p < 0.001) and Kujala scores, which increased from 49.2 to 85.5 (p < 0.001). Post-operative PTAs and PCA decreased from 19.6 ± 8.8 to -3.4 ± 6.2, and from 24.6 ± 7.3 to 13.1 ± 3.8 degrees respectively (p < 0.001). No patients showed lateral translation more than grade II in the patellar-glide test. Regarding patellar height, a tiny reduction (Δ = 0.02, Δ max = 0.09) was discovered in using CDR (p = 0.027), rather than ISR or BPR. All measurements of radiographic indices had an excellent intra- and inter-rater reliability (ICC > 0.75). Isolated anatomic MPFLR is sufficient to achieve good clinical outcomes, as well as patellofemoral stability and high rates of return-to-sport. However, it is unclear if the reconstructed MPFL has a contributory effect on reducing patellar height.

A case report of lateral subtalar dislocation

Introduction: Subtalar or peritalar dislocation is defined as simultaneous dislocation of talocalcaneal and talonavicular joint. Most injuries are caused by moderate to high energy trauma including motor vehicle accidents and falls from height. This case is operated for lateral subtalar dislocation treated with open reduction.Case: A 35 year old male patient came to Emergency Department of C U Shah Medical College And Hospital, Surendranagar with complaints of pain and tenderness over left ankle after history of road traffic accident between patient and bike. On clinical examination, it revealed tenderness and eversion deformity of the foot. Dorsalis pedis and Posterior Tibial pulses were intact. Sensation in the foot was preserved.Conclusion: Subtalar dislocations are rare but serious injuries of the talus this injury is usually due to high energy trauma. Early diagnosis and urgent reduction are the prerequisites for a satisfactory functional outcome. The prognosis is generally good, although long-term monitoring is required to combat the appearance of subtalar arthrosis.

Medial patellofemoral ligament reconstruction is superior to active rehabilitation in protecting against further patella dislocations

PurposeIsolated reconstruction of the medial patellofemoral ligament (MPFL-R) has become the predominant stabilizing procedure in the treatment of recurrent lateral patellar dislocation (LPD). To minimize the risk of re-dislocations, isolated MPFL-R is recommended in patients with no significant trochlea dysplasia and tibial tuberosity trochlear groove distance < 20 mm on computed tomography (CT). Incidentally, these criteria are the same that are used to identify first time LPD patients where conservative treatment is recommended. The purpose of this study was therefore to compare MPFL-R with active rehabilitation for patients with recurrent LPD (RLPD) in absence of the above mentioned underlying anatomical high-risk factors for further patellar dislocations.MethodsRLPD-patients aged 12–30 without underlying anatomical high-risk factors for further LPD were randomized into treatment either with isolated MPFL-R or active rehabilitation provided and instructed by a physiotherapist. All patients underwent diagnostic arthroscopy for concomitant problems. The main outcome measure was persistent patellar instability at 12 months. Knee function at baseline and 12 months was asses using the following patient reported outcomes measures (PROMS); KOOS, Kujala, Cincinnati knee rating, Lysholm score and Noyes sports activity rating scale.ResultsBetween 2010 and 2019, 61 patients were included in the study (MPFL-R, N = 30, Controls, N = 31). Persistent patellar instability at 12 months was reported by 13 (41.9%) controls, versus 2 (6.7%) in the MPFL-group (RR 6.3 (95% CI 1.5–25.5). No statistically significant differences in activity level were found between the MPFL-group and the Controls at neither baseline nor follow up. The patients with persistent instability at 12 months did not score significantly lower on any of the PROMs compared to their stable peers, regardless of study group.ConclusionPatients with recurrent patellar dislocations have a six-fold increased risk of persistent patellar instability if treated with active rehabilitation alone, compared to MPFL-R in combination with active rehabilitation, even in the absence of significant anatomical risk factors. Active rehabilitation of the knee without MPFL-R improves patient reported knee function after one year, but does not protect against persistent patellar instability.Level of evidence1.

Diagnostic Performance of MRI Versus CT in the Evaluation of Intra-articular Osteochondral Fracture in Pediatric Patients With Acute Traumatic Lateral Patellar Dislocation.

Background:Evaluation of intra-articular osteochondral fractures in children with acute traumatic lateral patellar dislocation (LPD) is important for determining treatment options.Purpose:To (1) compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for evaluating intra-articular osteochondral fractures; (2) compare the interpretation of CT and MRI images between radiologists and pediatric orthopaedic surgeons (POS); and (3) investigate any clinical factors influencing the accuracy of CT and MRI evaluations.Study Design:Cohort study (diagnosis); Level of evidence, 2.Methods:We reviewed 35 knees in 35 patients (mean age, 12.2 ± 1.2 years; 12 boys and 23 girls) who were treated arthroscopically for acute traumatic LPD; 71% of the patients had patellar fractures, 54% had femoral fractures, and 60% had free osteochondral fracture fragments. All presurgical MRI and CT images were reviewed by POS who were blinded to both the reports of the radiologists and surgical records. We compared the accuracy of CT and MRI in diagnosing intra-articular osteochondral fractures against the arthroscopic findings and compared the interpretation of the images by the POS (MRI-O, CT-O) with those of the radiologists (MRI-R, CT-R).Results:There was no significant difference in diagnostic accuracy between CT and MRI for overall intra-articular osteochondral fractures by the POS or the radiologists; however, the CT-O images had a higher diagnostic specificity (84.2% vs 69.6%; P < .001) and sensitivity (88.1% vs 70.1%; P < .001) versus the MRI-R images. Regarding free fracture fragments, the CT-R images had a higher diagnostic accuracy than the MRI-R images (73.5% vs 47.1%; P = .026). When backed by clinical data, the MRI-O images had greater diagnostic accuracy (78.7% vs 60.3%; P = .001) and sensitivity (88.1% vs 30.7%; P = .021) but lower specificity compared with the MRI-R images, and the CT-O images had similar diagnostic accuracy but greater sensitivity than the CT-R images (70.1% vs 52.2%; P < .001). The diagnostic accuracy of MRI-O images was lower for children under 12 years versus children 12 years and over (67.5% vs 83.3%; P = .040).Conclusion:Compared with MRI, CT scans had better diagnostic performance in the evaluation of intra-articular osteochondral fractures in pediatric patients with acute traumatic LPD. Clinical data enhanced the diagnostic sensitivity of MRI and CT but decreased the specificity of MRI. MRI evaluations remain challenging for both POS and radiologists.

The Patellar Instability Probability Calculator: A Multivariate-Based Model to Predict the Individual Risk of Recurrent Lateral Patellar Dislocation

Background: Predicting the risk of recurrence is of great interest when counseling patients after primary lateral patellar dislocation (LPD). Purpose: To investigate a multivariate model to predict the individual risk of recurrent LPD. Study Design: Case-control study; Level of evidence, 3. Methods: The study population included patients with primary LPD, knee imaging, and a minimum 2-year follow-up after nonoperative treatment. Data including patient characteristics and anatomic patellar instability risk factors were collected retrospectively from 7 national study centers. Bivariate and multivariate regression analyses were carried out to identify risk factors for recurrent LPD and to generate an accuracy-optimized model for out-of-sample prediction. Results: In total, 115 of 201 patients (57%) experienced recurrent LPD within 2 years after primary LPD. Age ≤16 years at primary LPD (odds ratio [OR], 5.0), history of contralateral instability (OR, 2.4), and trochlear dysplasia (Dejour type B-D: OR, 2.5; lateral trochlear inclination ≤12°: OR, 2.7) were significant risk factors for recurrent LPD (P < .05). The prediction accuracy including these 3 risk factors was 79%. Patella alta, an increased tibial tubercle to trochlear groove distance, and patellar tilt had neither an association with increased recurrence rates nor an influence on prediction accuracy of recurrent LPD. Conclusion: Young age and trochlear dysplasia are major risk factors for early recurrent LPD. A multivariate model including age at primary LPD, lateral trochlear inclination, and history of contralateral LPD achieved the highest prediction accuracy. Based on these findings, the patellar instability probability calculator is proposed to estimate the individual risk of early recurrence when counseling patients after primary LPD.

Using the radiocoronoid line for diagnosis of elbow dislocation.

The radiocapitellar line (RCL) has been widely used to diagnose elbow dislocation. However, there are limitations to the RCL, with the cartilaginous portion of bone making interpretation of radiographs difficult. The study aims to show that the radiocoronoid line, which connects two points on the medial aspect of the radius, proximal to the radial tuberosity, is more suited to diagnose elbow dislocations in the anterior-posterior projection. This study also observes factors affecting accuracy of the radiocapitellar line. The radiographs of 50 normal and 17 laterally dislocated elbows were obtained. An unbiased independent reviewer drew the radiocoronoid and radiocapitellar line (RCL). Four other blinded independent reviewers drew the RCL and the radiocoronoid line for 20 radiographs and repeated the process a week later. The accuracy of the RCL was assessed using distance away from bisection point of capitellum, and ratio (distance from the point where line crosses capitellum to lateral aspect of capitellum over the total width of capitellum). The relationship of the radio-coronoid line and the lateral aspect of coronoid fossa was assessed, with dislocation being the line lateral to it and normal being medial to or on it. The radiocoronoid line had a higher accuracy (95.5%) compared to RCL (32.8%), higher specificity (94%) compared to RCL (10%) as well as higher positive predictive value (85%) compared to RCL (27.4%). There was no intra- or inter-observer variability for the radio-coronoid line. Skeletal age statistically predicted the ratio for the male population ( P < 0.05), however, the independent variables did not statistically predict the dependent variables for the female and total population. The radiocoronoid line serves as an additional method to assess radiocapitellar joint lateral dislocation. It is more accurate and reliable than the radiocapitellar line in the anterior-posterior projection. Sex and skeletal age also influence the accuracy of the radiocapitellar line with the radiocapitellar line nearing the bisection point as skeletal age in males increases.

What are the Risk Factors for Infection after Operative Treatment of Subtalar Fracture Dislocations?

Category:Ankle; TraumaIntroduction/Purpose:Subtalar fracture dislocations are a rare hindfoot injury with relatively little evidence to inform surgeons about outcomes and risk factors for complications. Some previously documented poor prognostic factors include lateral and complicated dislocations, total talar extrusions, and concomitant fractures. The mechanism of injury often results from high energy trauma and has been reported as severe inversion (medial dislocation) or eversion (lateral dislocation) of the foot. The purpose of this study was to assess the risk factors associated with deep infection after operative treatment of subtalar fracture dislocations.Methods:A retrospective cohort study at a single level 1 trauma center was performed to identify patients who had operative treatment of a subtalar fracture dislocation over an 11 year period (2008-2019). Patients were identified by review of the electronic health record and data collected included patient demographics, injury characteristics, and treatment choices. Deep infection was defined as return to the operating room for debridement. Minimum follow-up for inclusion was 3 months. Descriptive analyses (means, medians, standard deviations, ranges, frequency distributions) were used to assess and describe the group. Chi-square tests of association and independent-sample t tests were used to assess differences between the infected group and those without infection.Results:A total of 154 met criteria for this study. The most common associated fractures were talus (47%) and calcaneus (33%). Approximately every 1 in 8 patients (12.3%) patients developed a deep infection. The infected group was older (47.2 vs 39.5 years, p=0.03). Tobacco users were found to have a significantly higher rate of postoperative deep infection (74 vs 34%, aOR=7.4, 95% CI, 2.3-24.1, p=0.001). There was a significantly higher proportion of infection in patients with Gustilo-Anderson type 3 open fractures (32 vs 12%, aOR=5.7, 95% CI, 1.6-20.3, p=0.007). The infected group had a higher proportion of below the knee amputation (47 vs 1%, p<0.001).Conclusion:Infection after operative management of subtalar fracture dislocations can be devastating, with 47% of infected patients requiring amputation. Risk factors for infection after subtalar fracture dislocation include older age, smoking, type 3 open fracture, and freshwater contamination. Ultimately demographic and injury characteristics seem to drive the risk of infection in subtalar fracture dislocations.

Trauma dentoalveolar induzido por intubação em cirurgia bucomaxilofacial de urgência: relato de caso

ABSTRACT Dental trauma is a common complication in general anesthesia, especially when using nasotracheal intubation during the classic laryngoscopy. Risk factors range from difficult intubation through difficult airways to occlusal changes in the patient, with incisors being widely affected by dental elements. Tooth avulsion is the most frequent type of trauma, followed by lateral dislocation and root fracture. Male patient, 39 years old, presented at the Emergency and Trauma Hospital in Caruaru/PE, a motorcycle accident victim with a bilateral jaw fracture. Given the need to fix fractures, the patient underwent a surgical procedure under general anesthesia. During laryngoscopy, heavy bleeding was observed in the oral cavity. After inspection, root fracture of lateral incisor and avulsion of right central incisor were noted. The avulsionated tooth was not found. An orthopedic image intensifier was used to locate the dental element in the thoracic region. However, it was not possible to determine its location. Therefore, an upper gastrointestinal (UGI) endoscopy was requested, and the dental element was in the digestive tract at the esophagus level. The tooth was removed, and the surgical procedure for osteosynthesis of bilateral mandible fracture was carried on. Dentoalveolar traumas induced by general anesthesia are frequent and require preventive measures since they can directly affect the patient’s physical, economic, and medical conditions, along with anesthesiologists and maxillofacial surgeon’s risk of receiving a civil lawsuit.

Patellofemoral Instability in Children: Imaging Findings and Therapeutic Approaches

Patellofemoral instability (PFI) is common in pediatric knee injuries. PFI results from loss of balance in the dynamic relationship of the patella in the femoral trochlear groove. Patellar lateral dislocation, which is at the extreme of the PFI, results from medial stabilizer injury and leads to the patella hitting the lateral femoral condyle. Multiple contributing factors to PFI have been described, including anatomical variants and altered biomechanics. Femoral condyle dysplasia is a major risk factor for PFI. Medial stabilizer injury contributes to PFI by creating an imbalance in dynamic vectors of the patella. Increased Q angle, femoral anteversion, and lateral insertion of the patellar tendon are additional contributing factors that affect dynamic vectors on the patella. An imbalance in the dynamics results in patellofemoral malalignment, which can be recognized by the presence of patella alta, patellar lateral tilt, and lateral subluxation. Dynamic cross-sectional images are useful for in vivo tracking of the patella in patients with PFI. Therapeutic approaches aim to restore normal patellofemoral dynamics and prevent persistent PFI. In this article, the imaging findings of PFI, including risk factors and characteristic findings of acute lateral patellar dislocation, are reviewed. Non-surgical and surgical approaches to PFI in pediatric patients are discussed.

Comparative study between quadriceps tendon sling and semitendinosus graft for medial patellofemoral ligament reconstruction

Background Acute patellar dislocation is a common knee injury. The main injured structure is the medial patellofemoral ligament (MPFL). This ligament is the main static stabilizer against lateral patellar dislocation. Many surgical techniques have been described for the management of MPFL tear. The gold standard graft used for reconstruction is the hamstring. This study was done to compare the results of quadriceps tendon sling with semitendinosus graft for MPFL reconstruction (MPFLR). Patients and methods A prospective comparative study was held on 62 patients in El-Hadra University hospital between March 2018 and November 2019. Patients were divided into two groups. Group A had quadriceps graft and group B had semitendinosus graft for MPFLR. Patients were matched for age, sex, and body mass index. All cases were assessed clinically and functionally over 12 months of follow-up. Results There was no statistically significant difference between the 2 groups regarding Lysholm, Tegner, International Knee Documentation Committee, Visual Analog Scale, and Kujala scores. However, there was a statistically significant difference regarding the SCAR score. Conclusion Quadriceps tendon sling is a reliable alternative for MPFLR, especially in patients with small patellae or previous anterior cruciate ligament reconstruction.

Address the cause, not the effect: C1-2 joint manipulation and not odontoidectomy in congenital atlantoaxial dislocation and basilar invagination

The C1-2 joints in cases of congenital atlantoaxial dislocation are often oblique in both sagittal and coronal planes giving rise to anteroposterior and vertical slip of C1 over C2. Asymmetry on either side gives rise to coronal/lateral angular tilt along with rotational component. The dislocation is a dynamic process though it may appear to be fixed. The compressing dens is effect of dislocation and not the cause. The treatment should be directed towards C1-2 joint manipulation that would realign the joints as well as the dens. The facetal osteotomies coupled with manipulation for realignment in all planes provides a composite solution for even the complex lateral dislocation or complete spondyloptosis with severely deformed C1–2 joints, obviating the need for transoral decompression.

Polarization Interference and Modulation in the Low-Frequency Range

Conventional polarized light interference is realized by using the natural crystals sandwiched between two linear polarizers, which has applications in optical signal modulation and photomechanics. However, due to a shortage of suitable birefringent materials, a similar effect has not been reported in the low-frequency range. In this paper, a compact and tunable polarization interference system working in the microwave band has been proposed, employing artificially structured planar materials, i.e., two metal screens perforated with subwavelength apertures. One screen splits the incident linear polarization into two orthogonal electric components and the other combines the parallel electric components (in a certain direction) to induce an interference. We find that the near-field coupling between the two metal screens plays a crucial role and the polarization interference effect is strongly dependent on the lateral dislocation of the system. The theory and experiment demonstrated that, by laterally displacing one metal screen (at the millimeter scale), a nearly linear modulation of transmission intensity (93.1%--1.4%) can be achieved. The proposed effect can be extended to the THz range and may be valuable for constructing the microwave or THz modulators.

Medial patellofemoral ligament MRI abnormalities in the setting of MCL injuries: are they clinically relevant?

To assess MRI abnormalities of the medial patellofemoral ligament (MPFL) in patients with clinically and MRI-proven superficial medial collateral ligament (sMCL) injuries and determine the clinical significance. High-field strength knee MRI examinations were selected which demonstrated sMCL injuries. These cases were retrospectively reviewed for the presence, location, and severity of MPFL abnormality. The MPFL was divided into a more superior transverse component arising from a femoral attachment (tMPFL), and a broader more inferior oblique decussation component (odMPFL) arising from the anterior margin of the upper sMCL. Chart review was performed to determine the clinical relevance of any MPFL findings. One hundred patients with MCL injury were identified. These included 37 grade I sprains, 33 partial tears, 20 high-grade partial tears, and 10 full thickness tears. Abnormal edema was present at the femoral attachment of the tMPFL in 83%. The odMPFL was abnormal in 90%, most commonly involving the femoral third. No patients had imaging evidence of concurrent lateral patellar dislocation on the initial MRI study. No patients had documented patellofemoral instability at the time of original injury or upon follow-up. No patients required MPFL reconstruction. The MRI appearance of the MPFL is abnormal in the majority of patients with clinically and MRI-documented sMCL sprains and tears. These cases had no evidence of concurrent lateral patellar dislocation on the initial MRI and did not develop patellar instability symptoms.

Subtalar Dislocations.

Subtalar dislocations are uncommon injuries that involve disruption of the talocalcaneal and talonavicular joints. Whereas medial subtalar dislocations are usually caused by low-energy mechanisms and are reducible by closed means, lateral subtalar dislocations occur due to high-energy trauma, have associated foot injuries, and may require open reduction. Good outcomes can be expected for low-energy medial dislocations, whereas high-energy dislocations have guarded outcomes. Hindfoot deformity and chronic instability can result from nonanatomic reduction and inadequate stabilization. Arthrosis of the subtalar joint can occur despite anatomic reduction and is attributable to the cartilage damage at the time of injury.

TT-TG: où se trouve la déformation?

The tibial tubercle trochlear groove distance (TT-TG) is one of the major risk factors for patellar instability. This distance can be increased in case of medialized trochlear groove (TG), lateralized tibial tubercle (TT) or intra-articular torsion. The aim of this study is to define the origin of an increased TT-TG. Seventy MRI performed for lateral patellar dislocation (PFD) and trochlear dysplasia were retrospectively analysesd and compared with an age and gender matched control group without trochlear dysplasia (Ctrl, n = 70). TT-TG distance was measured on the most proximal image where the TG was first seen, to the center of the patellar tendon tibial on its tibial insertion. The medialization of the TG was measured in percentages along the posterior condylar line, with the maximal condylar width of the distal femur as reference. The position of the TT was measured using the TT-PCL distance. Intra-articular femoro-tibia torsion was measured using the angle between the posterior condylar lines of the femur and tibia (pcl-a). The mean TT-TG was 15.9 ± 4.9 mm in PFD and 8.2 ± 3.8 mm in Ctrl (P < 0.564) than in Ctrl. Forty-one knees of the PFD had a TT-TG > 15 mm (PFD+), and 29 below (PFD−). TG in PFD+ was 3.1 mm more medialized (P < 0.123) than in PFD−. In the PFD+ with a TT-PCL > 21 (n = 27), TG was 3.4 mm more lateralized (P < 0.035) than in PFD+ with a TT-PCL < 21 (n = 14). The pcl-a showed an increased tibial internal rotation in Ctrl (9.4° ± 5.5°) compared to PFD (2.6° ± 5.7°, P < 0.001), whereas no difference in the pcl-a between PFD+ and PFD− was found. Increased TT-TG in PFD can only partially be explained by osseous measurement on the femur and the tibia. Intra-articular rotation might play an important role. In PFD with increased TT-TG, medialized trochlear groove might be the most important factor. Indication for TT osteotomy should be evaluated carefully when using TT-TG.

Visualization of osteochondral fragments in the cavity of the knee joint in case of patellar dislocation in children

The objective was to assess the capabilities of MRI and CT in visualizing free bone and cartilage fragments in the knee cavity after lateral dislocation of the patella. Materials and methods. CT and MRI were performed in 220 patients, including 127 girls and 93 boys aged 12 to 18 years (mean age 14.5 years), with acute lateral patellar dislocation. Results. Lateral dislocation of the patella in 25% of cases led to the appearance of osteochondral fragments. CT scan revealed and confirmed osteochondral fragments surgery in 55 people (100%), MRI scan - in 50 people (90%). The sites of the detachment of the osteochondral fragments were: a medial facet of the patella in 22 (38.8%), the outer edge of femur lateral condyle in 33 (58.2%), t patella and lateral condyle of the femur in 2 patients (3%). Free cartilage fragments not detected by CT were detected by MRI in 2 patients. Conclusion. Patellar dislocation is an injury that is likely to require surgery. The volume of osteochondral and soft tissue lesions can be established with the maximum degree of probability by MRI while detecting small osteochondral fragments is most reliable with CT. Combining these two observation methods provides the complete possible information about the extent of damage, which allows timely resolution of treatment tactics.

Lateral subtalar dislocation associated with a lateral malleolus and a nutcracker cuboid fracture: Case report of a rare pattern of lesion.

Introduction and importanceCombined fracture of the lateral malleolus and cuboid due to a lateral subtalar dislocation is an uncommon injury. Literature is scarce on this trauma association. To the best of our knowledge, this represents a new lesion pattern. Hereby we describe its mechanism, management and outcomes.Case presentationWe report a case of a 58-year-old woman, who fell from the stairs and presented with pain and an acute deformity of the left foot and ankle. Plain radiographs and CT scan revealed a lateral subtalar dislocation with a lateral malleolus and cuboid fractures. After a failed closed reduction, the patient underwent an open reduction and fixation of the talonavicular joint. An external fixator was applied to address the cuboid fracture. The lateral malleolus was treated conservatively with 5.5 weeks of immobilization. At 38 months of follow-up, the patient scored 87% on the AOFAS ankle-hindfoot scale and returned to normal daily activity. Radiographs demonstrate signs of posttraumatic arthritis at the subtalar and talonavicular joints.Clinical discussionAfter reduction of the lateral subtalar dislocation, addressing the nutcracker cuboid fracture was essential, since it can contribute to a flatfoot deformity. Although the patient progressed to posttraumatic arthritis, the sequelae are usually well tolerated and a good outcome was achieved.ConclusionThe rarity of this pattern of lesion is related to the necessary multidirectional forces. Correct management of the associated fractures is essential.Our study demonstrates a new lesion pattern of lateral subtalar dislocations, its mechanism, management and outcomes.

Is an individually tailored programme of intense leg resistance and dynamic exercise acceptable to adults with an acute lateral patellar dislocation? A feasibility study

BackgroundLateral patellar dislocations mainly affect active teenagers and young adults. To help people recover, non-surgical exercise-based treatment is often recommended but the optimal exercise-based treatment is unknown. Currently, treatment outcomes after this injury are variable. Common problems include recurrent dislocation, reduced activity levels, and later surgery. A programme of intense leg resistance exercises, and dynamic exercises related to participants’ activity-related goals, has rationale, but has not been previously reported. In line with the Medical Research Council guidance, this study aimed to assess the acceptability of a novel evidence-based exercise programme for adults after acute lateral patellar dislocation and the feasibility of future research evaluating this treatment.MethodsA single-group prospective study was conducted at the John Radcliffe Hospital, Oxford, UK. Participants were 16 years or older with an acute first-time or recurrent lateral patellar dislocation. Participants received up to six face-to-face, one-to-one, physiotherapy sessions, over a maximum of 3 months, and performed intensive home exercises independently at least three times per week. Strategies to increase exercise adherence were used. Primary objectives were to determine the number of eligible patients, the recruitment rate (proportion of eligible patients that provided written informed consent), participant adherence to scheduled physiotherapy sessions and self-reported adherence to prescribed exercise, and intervention acceptability to participants measured by attrition and a study-specific questionnaire. Data were analysed using descriptive statistics.ResultsFifteen of 22 (68%) patients with a lateral patellar dislocation were eligible. All eligible (100%) were recruited. Two of 15 (13%) participants provided no outcome data, 2/15 (13%) provided partial outcome data, and 11/15 (73%) provided all outcome data. Questionnaire responses demonstrated high intervention acceptability to participants. Participants attended 56/66 (85%) physiotherapy sessions and 10/11 (91%) participants reported they ‘always’ or ‘often’ completed the prescribed exercise. One participant redislocated their patella; another experienced knee pain or swelling lasting more than one week after home exercise on three occasions.ConclusionThe intervention appeared acceptable to adults after acute lateral patellar dislocation, and a future randomised pilot trial is feasible. This future pilot trial should estimate attrition with increased precision over a longer duration and assess participants’ willingness to be randomised to different treatments across multiple centres.Trial registrationClinicalTrials.govNCT03798483, registered on January 10, 2019

Peak shear strength criterion for mismatched rock joints: Revisiting JRC-JMC criterion

Rock joints with different matching conditions are widely existing in nature. The safety of engineering structure is significantly affected by the peak shear strength of mismatched rock joints; however, the available criteria do not work well for evaluating the peak shear strength of mismatched rock joints. In this study, the mismatched rock-like joints are first simulated by imposing various lateral dislocations along the shear direction, and then a series of direct shear tests are performed to investigate the influence of lateral dislocation on the peak shear strength. Experimental results show that the peak shear strength decreases with the increase in the lateral dislocation, even the specimens have identical single surface morphology. An empirical peak shear strength criterion with the inclusion of normalized lateral dislocation is developed to evaluate the peak shear strength of mismatched rock joint, which is further validated by tri-angular rock-like joints with various openings and natural mismatched rock joints. Compared to the available criterion in the literature, the developed one is in line with the achieved experimental results better. Finally, the limitations of the developed criterion are preliminarily discussed.