Online ahead of print. government site. 1, Sports Medicine and Arthroscopy Review, Vol. Knee Surg Sports Traumatol Arthrosc. 15, No. Knee Surg Sports Traumatol Arthrosc. 2 Baldwin JL. Potential soft-tissue injuries include a partial- or full-thickness tear of the medial soft-tissue restraints, including the medial patellofemoral ligament and medial retinaculum [7, 11, 12]. Two radiologists (one senior radiologist with 20 years of experience in MRI and other in training with 3 years of experience) independently evaluated all the cases in this study. 27, No. [1] After the injury, the patient usually seeks medical attention because of persistent pain and swelling, which is typically located along the medial joint line, and the patient occasionally complains of a locking or catching sensation. The Horizontal Beam Lateral view is useful for assessing soft tissues as well as bones. During the second phase of the injury, the patella reduces to its normal position within the trochlear groove. Lateral radiograph shows a patella alta and signs of 10, No. The patella then proceeds to bounce back into its normal position within the trochlear groove. 3, Clinics in Sports Medicine, Vol. 8, Orthopaedics & Traumatology: Surgery & Research, Vol. This line was copied into the transverse section showing tibial tubercle. 1, Arthroscopy: The Journal of Arthroscopic & Related Surgery, Vol. and transmitted securely. Patients consent not required as patients identity is not disclosed or compromised. 10, Journal of Orthopaedic Surgery and Research, Vol. In this study, we have attempted to evaluate the predisposing factors of patellar instability on magnetic resonance imaging (MRI) and to compare the significance of measurement at the level of trochlear bone versus cartilage for trochlear dysplasia. 6). 14, No. In this report, the location of the donor sites was not specifically described, but review of the images in the report shows the donor sites to be located in the trochlear groove portion of the lateral femoral condyle [6]. .switcher a {text-decoration:none;display:block;font-size:10pt;-webkit-box-sizing:content-box;-moz-box-sizing:content-box;box-sizing:content-box;} official website and that any information you provide is encrypted sharing sensitive information, make sure youre on a federal 3, The American Journal of Sports Medicine, Vol. Eighteen (60%) and 25 (83.33%) out of 30 cases were positive for trochlear facet asymmetry when measured at the level of trochlear bone and cartilage, respectively. The shape of the patella is classically not considered a predisposing factor. Bookshelf Subluxation is when the joint is still partially attached to the bone.. HHS Vulnerability Disclosure, Help Transverse dimensions were obtained from the coronal images, whereas anteroposterior dimensions were obtained from the sagittal images. It assesses the pattern of fractures, involvement of the radioulnar joint and presence of a distal ulnar fracture.. Wolfe S, Varacallo M, Thomas JD, Carroll JJ, Kahwaji CI. 7, No. 38, No. All patients underwent MRI examination on Philips Achieva dstream 1.5 Tesla MRI using Sense Body Coil. 10, The American Journal of Sports Medicine, Vol. Knee Surg Sports Traumatol Arthrosc. 1, American Journal of Roentgenology, Vol. [15] where a specificity and sensitivity of 96% and 100%, respectively, were established for both trochlear facet asymmetry and trochlear depth as a diagnostic tool for patellar instability. Influence of tibial tuberosity position and trochlear depth on patellar tracking in patellar instability: Variations with Patella Alta. 12, No. Patients complain of the knee suddenly giving way, and inability to weight-bear or extend the knee and are often in considerable pain. Thirty patients of patellar instability were assessed on MRI for risk factors of patellar instability including trochlear dysplasia, tibial tuberosity to trochlear groove (TT-TG) distance, and patellar height ratio. Enter your email address below and we will send you your username, If the address matches an existing account you will receive an email with instructions to retrieve your username. At the inferomedial patella, 70% (57 of 82) of LPD examinations showed osteochondral injury and 44% (36 of 82) showed concave impaction deformity (0 of 100 control subjects). Early magnetic resonance imaging and surgical treatment should be considered in obese patients, male patients, and patients with physeal closure and after traumatic LPD. Dr Graham Lloyd-Jones BA MBBS MRCP FRCR - Consultant Radiologist - 12, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. 1, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. Epidemiology 51, No. In case of traumatic lateral patellar dislocation (LPD), the likelihood of patellar and femoral chondral and osteochondral lesions is significantly higher than in nontraumatic LPD. Not infrequently the formation of a lipohaemarthrosis is the only radiological sign. Camp et al. [16], Patellar height ratio was evaluated on sagittal sections of knee MRI as a ratio between patellar tendon length and longest craniocaudal diameter of patella (Insall-Salvati ratio). 2022 Aug 22. doi: 10.1007/s00167-022-07120-1. Hip & Knee. Eighty-two examinations were performed in 81 patients with LPD (mean age, 20 years; age range, 9-57 years). 9, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. 1, BMC Musculoskeletal Disorders, Vol. 6, Journal of Computer Assisted Tomography, Vol. The arthroscopic surgeries were performed by a number of orthopedic surgeons with varying levels of experience and expertise. During reduction, the articular surface of the medial aspect of the lower pole of the patella first impacts the nonarticular portion of the lateral femoral condyle, resulting in the classic bone contusion. MRI of Spinal Bone Marrow: Part 2, T1-Weighted Imaging-Based Differential Diagnosis, Review. 7, Orthopaedic Journal of Sports Medicine, Vol. [1] also described a very low incidence of patellar instability in more than 30 years of age. Looser zones are also a type of insufficiency fracture. CT is commonly necessary for fracture characterization of the fragment size, the degree of anteromedial involvement, and complex fracture-dislocation. Zhang GY, Zheng L, Shi H, Qu SH, Ding HY. There is a moderate-sized joint effusion and no synovial hypertrophy or intra-articular body. MRI also allows evaluation of ligaments and osteochondral lesions. 25, No. 44, No. 26, No. 39, No. These dislocations are often transient, and as a result, the patient and clinician may be unaware of the true nature of the injury. Osteochondral defects of the lateral femoral condyle are a common sequela after transient lateral patellar dislocation. Consequently, our objective was to determine the incidence of lateral femoral condyle osteochondral injuries and to better define the locations and patterns of chondral injury involving the lateral femoral condyle after transient dislocation of the patella based on MRI and follow-up arthroscopy. Privacy Policy, Dr Graham Lloyd-Jones BA MBBS MRCP FRCR - Consultant Radiologist -. Arthroscopy confirmed the presence of chondral defects of the lateral femoral condyle in six (75%) of the eight cases. Azar FM, Canale ST, Beaty JH. Li J, Chen C, Zhou H, Zhai J, Zhao H, Li L. Evid Based Complement Alternat Med. 4, No. Another limitation of this study is that MRI examinations were performed on different scanners, which could affect the ability to detect chondral abnormalities. 4, Journal of Computer Assisted Tomography, Vol. This proved to be a highly predictable pattern of injury and was observed in each of the 10 cases. Terminology. One recent report describes seven patients in whom lateral femoral condyle shearing fractures were identified on conventional radiography after lateral patellar dislocation. 24, No. The depth of the lateral femoral notch sign has been shown to correlate with anterior cruciate ligament (ACL) tear 2. Lateral radiograph revealing high patella, suprapatellar recess joint effusion and soft tissue swelling, with no evidence of patellar fracture. The disadvantage of choosing a fixed distance from joint line is that it does not consider into account the variation of height among study group. The clinical history and physical findings may be inadequate to establish the exact nature of the injury, and as a result MRI can play a key role both in establishing the correct diagnosis and in delineating the extent of osseous and soft-tissue injury essential for directing appropriate surgical management [1]. Twelve cases (40 %) were positive for patella alta. Purpose: An official website of the United States government. MPFL ligament injuries are best seen in MRI, appearing disrupted and hyperintense on T2-WI [2]. This finding further supports the theory that the shearing injury occurs during the first stage of dislocation with the knee in a greater state of flexion, and as the knee extends, the patella rebounds and impacts the lateral aspect of the lateral femoral condyle anterior to the site of the chondral shearing injury. All patients were assessed for various risk factors for patellar instability including trochlear facet asymmetry (at the level of trochlear bone and trochlear cartilage), trochlear depth (at the level of trochlear bone and trochlear cartilage), lateral trochlear inclination, patellar height ratio, and TTTG distance. The main risk factors of instability are patella alta, trochlear dysplasia, lateralisation of tibial tubercle and insufficient MPFL. Forty-eight percent (39 of 82) showed more than one site of injury to the medial stabilizers; 45% (37 of 82) showed edema or hemorrhage at the inferior VMO. .switcher .selected a {border:1px solid #ccc;color:#666;padding:3px 5px;width:151px;} Radiology 1999; 213(P):115. 07, Orthopaedic Journal of Sports Medicine, Vol. Damage to medial stabilizers leads to recurrent patellar dislocation, especially if there are additional anatomical risk factors such as lateralization of the tibial tuberosity, trochlear dysplasia, and patella alta. [14], To calculate trochlear facet ratio, length of the medial and lateral trochlear facets was measured. .switcher .option a.selected {background:#fff;} 20, No. Avaliao dos fatores predisponentes nas instabilidades femoropatelares. In addition to the bone contusion pattern, osteochondral injuries of the patella have also been reported, and these range from mild articular cartilage surface irregularity to large displaced osteochondral fractures [1-4]. 38, No. Patients often complain of anteromedial knee pain which is attributed to MR/MPFL injury and osseous/chondral injury (involving medial aspect of patella and lateral aspect of femoral condyle). 1997 Jan;168(1):117-22. doi: 10.2214/ajr.168.1.8976933. 91, No. 50, No. 6, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. According to our study, trochlear depth and facet asymmetry produce better results as a predisposing factor for instability of patella when measured at the level of trochlear cartilage as compared to trochlear bone. 20, No. 2, Canadian Association of Radiologists Journal, Vol. Images were first evaluated for the presence of the typical bone contusion pattern involving the anterolateral femoral condyle and the inferomedial patella. 2, Current Physical Medicine and Rehabilitation Reports, Vol. 21, No. .switcher .selected {background:#fff linear-gradient(180deg, #efefef 0%, #fff 70%);position:relative;z-index:9999;} Trochlear dysplasia was diagnosed if trochlear depth was less than or equal to 3.0 mm [Figures 5 and 6]. Tuberculosis or Not Tuberculosis: Temporal Evolution of, The Role of Diffusion-weighted Magnetic Resonance Imaging in, Evaluation of Occult Femoral Neck Fractures Computed, Trochlear facet asymmetry at cartilage level. Evidence of a significant association emerged between patellar shape and patellar tilt in static (r(s) = 0.20, P = 0.019) or dynamic conditions (r(s) = 0.18, P = 0.031) and a significant association between Wiberg patellar shape type C and trochlear dysplasia grade 3 ((2) = 4.5, P = 0.035). According to our study, trochlear dysplasia is the most common predisposing factor of patellar instability (100%) followed by patella alta (40%) and TT-TG distance (23.3%). The reports were reviewed for evidence of prior lateral patellar dislocation. 32, No. Imaging of Anterior Cruciate Ligament Repair and Its Complications, Pictorial Essay. 25, No. Unbalance between dynamic medial and lateral stabilisers may act as an additional factor. The .gov means its official. Prevalence of patellar instability is higher in younger population, more frequently involving age equal to or <25 years. An 8-year-old female patient presented with a spontaneous patellar dislocation that was manually reduced by paramedics. Not all fractures that extend to the growth plate are Salter-Harris fractures. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. 1, Orthopaedic Journal of Sports Medicine, Vol. 8, Arthroscopy: The Journal of Arthroscopic & Related Surgery, Vol. 56, No. 101, No. 3, The American Journal of Sports Medicine, Vol. Before Comparison of measurement at the level of trochlear bone versus cartilage for trochlear facet asymmetry and trochlear depth. 12, International Orthopaedics, Vol. Distance between S and P is measured. Chondral defects located posterior to the anterior margin of the anterior horn of the lateral meniscus were designated as involving the weight-bearing aspect of the lateral femoral condyle. This area of the lateral femoral condyle should be closely evaluated for osteochondral injury on both sagittal and coronal MR images in all patients with evidence of prior transient dislocation of the patella. 9, No. 44, No. Tsuda E, Ishibashi Y, Yamamoto Y, Maeda S. Knee Surg Sports Traumatol Arthrosc. Previous studies have shown that high-field-strength systems provide significantly better diagnostic performance than the low-field-strength systems when evaluating grade 2 or 3 chondral defects, but low-field-strength systems can reliably evaluate high-grade chondral lesions, possibly because they imbibe joint fluid, thus providing adequate contrast [15, 16]. These cookies do not store any personal information. Knee - Patellar fracture - AP. 8, Sports Health: A Multidisciplinary Approach, Vol. [1] Generalized patellar instability is thought to represent up to 3% of clinical 4, The Physician and Sportsmedicine, Vol. 5, No. Patellofemoral instability is a clinical syndrome due to morphologic or dynamic changes in patellofemoral joint that lead to anterior knee pain and predispose to recurrent lateral patellar dislocation. 5, 2022 Radiological Society of North America, Acute Lateral Patellar Dislocation at MR Imaging: Injury Patterns of Medial Patellar Soft-Tissue Restraints and Osteochondral Injuries of the Inferomedial Patella, https://doi.org/10.1148/radiol.2253011578, Layered Approach to the Anterior Knee: Normal Anatomy and Disorders Associated with Anterior Knee Pain, Imaging Characteristics of Contralateral Asymptomatic Patellofemoral Joints in Patients with Unilateral Instability, MR Imaging of Patellar Instability: Injury Patterns and Assessment of Risk Factors1. Online ahead of print. 3, The American Journal of Sports Medicine, Vol. Epub 2013 Sep 8. Some authors suggest a better detection rate with 20 tilted or internal oblique radiographs 6,9. 10, Orthopaedic Journal of Sports Medicine, Vol. The statistical evaluation was done using Students t-test and SPSS version 24. Accessibility 1, The Open Orthopaedics Journal, Vol. Sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI are strong predictors of recurrent patellar dislocation. 32, No. 2, Archives of Orthopaedic and Trauma Surgery, Vol. With flexion at knee joint, patella articulates with trochlea at approximate 10 of flexion.[10-13]. 1, Archives of Orthopaedic and Trauma Surgery, Vol. 29, No. The smaller number of cases in our study could be attributed to higher cutoff used in our study. Conveniently the Salter-Harris types can be remembered by the mnemonic SALTR.. type I. slipped; 5-7%; fracture plane passes all the way through Bookshelf The significance of these findings is that when evaluating the MR images of a patient with bone contusions indicative of a prior transient dislocation of the patella, the radiologist should carefully evaluate the articular cartilage at the level of the posterior margin of the bone contusion because this is the most likely location for a femoral osteochondral injury to occur. Epub 2016 Dec 27. 2, Techniques in Knee Surgery, Vol. type I: avulsion of anterior glenoid margin; type II: transverse or oblique fracture through glenoid fossa exiting inferiorly; type III: oblique fracture through glenoid fossa exiting superiorly and associated with acromioclavicular joint injury; type IV: transverse fracture exiting through the medial 3, 22 August 2014 | Radiology, Vol. But opting out of some of these cookies may affect your browsing experience. Elias JJ, Soehnlen NT, Guseila LM, Cosgarea AJ. .switcher .option a {color:#000;padding:3px 5px;} Pathology. 10, No. Anatomic Risk Factors for Osteochondral Fracture of Acute First-Time Patellar Dislocation in Adolescents: A Retrospective Magnetic Resonance Imaging Study. [1,2] Lewallen et al. Thirty patients with clinical suspicion and MRI findings of patellar instability were enrolled in this single institutional observational study. This corresponds to the study done by Pfirrmann et al. The most common location of patella dislocations is lateral dislocation. According to our study, trochlear dysplasia is the most common predisposing factor of patellar instability (100%) followed by patella alta (40%) and TT-TG distance (23.3%). These cookies track visitors across websites and collect information to provide customized ads. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. New Hall Hospital, Salisbury, Wiltshire, UK, SP5 4EY. 3, International Orthopaedics, Vol. 38, No. The reports of 476 consecutive MRI examinations of the knee on patients under 36 years of age, which were performed at six referring outpatient imaging centers between January 1, 2005, and April 20, 2005, were retrospectively reviewed. and transmitted securely. Epub 2011 Dec 28. The final study group was composed of these 10 patients (male:female ratio, 7:3; age range, 15-22 years; mean age, 18 years). 2008 May;29(5):359-65. doi: 10.1055/s-2007-965360. Transient lateral patellar dislocation is a common injury that typically occurs in the young, athletic individual. Another strength of our study was the criteria used for deciding the level at which various measurements for diagnosis of patellar instability were performed. A fabella and a bipartite patella are 2 common normal variants that should not be mistaken for a fracture. They should not be confused with fatigue fractures which are due to abnormal stresses on normal bone, or with pathological fractures, the result of diseased, weakened bone due to Medial patellofemoral ligamanent is thickened and shows hypersignal, indicating ligament lesion. An additional limitation of this study is that multiple surgeons with varying skill levels operated on these patients, and there was no standardization of the surgical reports to confirm the size or precise location of the osteochondral lesions. 90, No. 101, No. Fractures of the patella may only be visible on 1 of the 2 standard views, more often the lateral view. In addition to the well-described osteochondral injuries of the lower pole of the patella, there have been a few reports in the literature regarding femoral condyle osteochondral injuries [6-10]. The distance between two lines was given as TT-TG distance. 2022 Nov 24. doi: 10.1007/s00167-022-07240-8. Seven cases (23.3%) had increased TT to TG distance. In the context of trauma the Lateral view is acquired with the patient lying supine and with a horizontal X-ray beam. Distance lines are used to calculate Insall-Salvati ratio: A: patellar tendon length (TL): length of the posterior surface of the tendon from the lower pole of the patella to its insertion on the tibia 2003 Sep;10(3):215-20 25, No. 5, Osteoarthritis and Cartilage, Vol. Zhang GY, Zheng L, Feng Y, Shi H, Liu W, Ji BJ, Sun BS, Ding HY. The osteochondral defects involved the articular surface of the trochlear groove in three (30%) of the 10 patients (Figs. The MR images of these 25 patients were then reviewed and 10 patients were found to have osteochondral defects involving the lateral femoral condyle. Indian J Radiol Imaging. It was found that 79% of patients with LPD had at least two out of four above-mentioned risk factors of patellar instability, in comparison to only 7% of patients in the control group. Active exercise therapy improves the recovery of knee joint function and reduction of muscle atrophy after medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Mean VMO elevation in the coronal plane of the adductor tendon was 2.2 cm, with a range of 0.6-4.5 cm (in control subjects, 0.9 cm; range, 0.1-2.5 cm; P <.001). The patella is a thick, flat, triangular bone with its apex pointing downwards. Treatment and prognosis. .switcher .option::-webkit-scrollbar-thumb {border-radius:5px;-webkit-box-shadow: inset 0 0 3px rgba(0,0,0,.3);background-color:#888;}. 2006 Mar;13(2):145-50 The MPFL femoral origin was identified in 87% (71 of 82); of these, 49% (35 of 71) showed injury. 2022 Sep 18. MeSH 34, No. The typical bone bruise pattern involving the anterolateral femoral condyle and inferomedial patella after transient lateral dislocation of the patella is a well-described MRI finding. Chondral defects overlapping the anterior margin of the anterior horn of the lateral meniscus were considered to be involving both chondral surfaces. 41, No. 2018 Mar;26(3):719-726. doi: 10.1007/s00167-016-4408-3. This website uses cookies to improve your experience while you navigate through the website. Low-field-strength magnets are limited in their ability to detect chondral abnormalities. [3] This article discusses tibiofemoral joint dislocation. 4, Operative Techniques in Sports Medicine, Vol. .switcher .selected a:after {height:16px;display:inline-block;position:absolute;right:5px;width:15px;background-position:50%;background-size:7px;background-image:url("data:image/svg+xml;utf8,");background-repeat:no-repeat;content:""!important;transition:all .2s;} Subchondral marrow edema was present underlying the chondral defects in 10 (100%) patients. Various MRI predisposing factors of patellar instability, their normal and cutoff values in patients with patellar instability. 37, No. Salter-Harris type I fractures are relatively uncommon injuries that occur in children.Salter-Harris fractures are injuries where a fracture of the metaphysis or epiphysis extends through the physis. [15], A line was drawn along the posterior plane of femoral condyle. Epidemiology. -. 39, No. Example of TT-GT measurement: Overlap axial images, one at the level of femoral condyle and other at the tibial tubercle. 1, Revista Chilena de Ortopedia y Traumatologa, Clinical Journal of Sport Medicine, Vol. The concave configuration of the trochlear groove protects its articular surface from injury during reduction of the patella, whereas the convex shape of the patella places its articular cartilage at risk for injury during the reduction stage as well. 1, Korean Journal of Radiology, Vol. The site is secure. Epub 2007 Sep 18. 17, American Journal of Roentgenology, Vol. Int J Sports Med. 1, The American Journal of Sports Medicine, Vol. Patellar dislocation is a common condition accounting for 23% of knee injuries [15, 29].Nearly 40% of patients with patellar dislocation experience recurrence after nonoperative treatment; [], and almost 50% of patients with recurrent patellar dislocation (RPD) require surgical intervention to regain stability [].Risk factors for RPD have been clarified to be Please enable it to take advantage of the complete set of features! Enter your email address below and we will send you the reset instructions. S Perpendicular line to A to the deepest point of trochlear sulcus. Christensen TC, Sanders TL, Pareek A, Mohan R, Dahm DL, Krych AJ. 1, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. Strictly speaking, a torus fracture refers to a circumferential buckle fracture 7.However, the terms are often used interchangeably. Trochlear facet asymmetry was characterized by a ratio which measured <40% and it indicated dysplasia [Figures 3 and 4]. Knee - Patellar fracture - AP. MATERIALS AND METHODS: MR imaging at 0.1 T was performed in 25 patients with an acute patellar dislocation, 24 of whom underwent surgery. OBJECTIVE. When the knee joint is in full extension, there is no articulation of patella and femoral trochlea, rather it lies superolateral to the uppermost trochlea. 5, No. 36, No. CT or MR may be more sensitive than conventional radiographs for detection of avulsion injuries. 6, Clinical Orthopaedics and Related Research, Vol. 48, No. Medial retinacular complex injury in acute patellar dislocation: MR findings and surgical implications. 11, Orthopedic Clinics of North America, Vol. Each of the lateral femoral chondral defects in our series was a full-thickness chondral defect with or without underlying cortical abnormality, which is similar to the findings reported by Swischuk et al. 1, American Journal of Roentgenology, Vol. MPFL repair after acute first-time patellar dislocation results in lower redislocation rates and less knee pain compared to rehabilitation: a systematic review and meta-analysis. We also use third-party cookies that help us analyze and understand how you use this website. Lateral dislocation of patella is common due to the divergent pull of the patellar tendons and quadriceps, which is further aggravated by the normal rest state valgus configuration of knee. 45, No. 11, Journal de Traumatologie du Sport, Vol. 1, Indian Journal of Musculoskeletal Radiology, Vol. vol.19 no.1 So Paulo 2011. The 25 cases were retrospectively reviewed in consensus by two musculoskeletal radiologists who had 7 and 18 years, respectively, of clinical experience in musculoskeletal radiology. Incidence and radiologic predictor of postoperative patellar instability after Fulkerson procedure of the tibial tuberosity for recurrent patellar dislocation. Radiology report. High-grade osteochondral injuries involving the patella or the lateral femoral condyle are often treated with abrasion chondroplasty or autologous chondrocyte transplantation, and treatment of these lesions has been shown to improve functional outcome in adolescent athletes [14]. 27, No. 2022 Aug 30;32(4):505-509. doi: 10.1055/s-0042-1755253. 95, No. On conventional radiograph of the knee, performed at the second episode of patellar dislocation, the patella appears laterally dislocated and there is soft-tissue swelling (Fig. 1, Patellar tendon. 6, Korean Journal of Radiology, Vol. When a person has a dislocated jaw it is difficult to open and close the mouth. 04, Orthopaedic Journal of Sports Medicine, Vol. 10, Indian Journal of Orthopaedics, Vol. 7, The American Journal of Sports Medicine, Vol. 32, No. (ISBN: 9783131692719), [5] The .gov means its official. 19, No. Our results highlight that the most critical factor responsible for patellar instability is trochlear dysplasia. 2A, 2B, 2C, 3A, 3B, and 3C). evaluated 103 patients with age <14 years for dysplastic trochlea, TT to TG distance, patellar tilt, and patella alta on MRI. Conclusion: Lateral dislocation of patella is prevented by various medial stabilizers, among which most important role is played by medial patellar retinaculum/medial patellofemoral ligament (MR/MPFL). Of the 25 patients for whom there was MRI evidence of prior transient dislocation of the patella, 10 (40%) were found to have chondral defects involving the articular surface of the lateral femoral condyle. Seven cases (23.3 %) had increased TT-TG distance [Table 2 and Graph 1]. 4), decreased lateral trochlear inclination (<11) and Dejour classification is used to describe trochlear morphology (Fig. Patients usually present with recurrent lateral patellar dislocation and patellofemoral instability. 1, The Egyptian Orthopaedic Journal, Vol. In their study, they also calculated median age for the first episode and recurrence of patellar dislocation as 16 years and 21 years, respectively. The https:// ensures that you are connecting to the Radiographic features Radiology Masterclass 2007 - now=new Date 36, No. Accessibility Dynamic tracking influenced by anatomy in patellar instability. Trochlear depth and facet asymmetry produce better results as a predisposing factor for instability of patella when measured at the level of trochlear cartilage as compared to trochlear bone with. 18, No. Typical osseous contusions in patellar dislocation, called kissing contusions, occur at medial patellar facet and lateral femoral condyle, resulting from patellar impactation after lateral dislocation and reduction. cartilage injury with associated subchondral fracture but without detachment 2, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. 2022 Jul 28;17(1):366. doi: 10.1186/s13018-022-03259-2. Pathology. Epidemiology. 14, No. Typically, Monteggia fracture-dislocations occur as the result of a fall onto an outstretched hand (FOOSH) 4.. Radiology 1993; 189:905-907. Patellar height ratio and TT-TG showed relatively less contribution for unstable patella. 2, Journal of Pediatric Orthopaedics, Vol. Transient lateral patellar dislocation: diagnosis with MR imaging. 46, No. Patellar shift ratio (PSR) is the optimal measurement for characterising lateral patellar shift and a reliable predictor of recurrent patellardislocation. As we move distally, the TG deepens, so the chances of patellar dislocation are less likely in distal trochlea. Translate this page into: Essex-Lopresti fracture-dislocation is characterized by a fracture of the radial head, dislocation of the distal radioulnar joint and rupture of the antebrachial interosseous membrane 3. [15] in which all these parameters were measured at a particular distance from the joint line, we decided the level of measurement by choosing the superior most axial section showing trochlear cartilage. intra-articular glenoid fracture. Multiple surgical options are now available for repairing osteochondral lesions, and this fact, combined with the fact that the majority of patients experiencing transient dislocation of the patella are young, increases the importance of accurately identifying these lesions [8, 12, 13]. 38, No. MR of the knee revealed hypersignal on DP FS sequences at the lateral aspect of lateral femoral condyle and medial facet of patella (Fig. This allows effusions to be visualised in the suprapatellar pouch. 19, No. 3, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. doi: 10.1148/rg.304095755. 3, World Journal of Methodology, Vol. 2022. Examinations at three of the centers were obtained using high-field-strength (1.5 T) magnets, and examinations at the other three centers were obtained using low-field-strength (0.2 T) magnets. 5, AMEI's Current Trends in Diagnosis & Treatment, Vol. High-Resolution 3-T MRI of the Fingers: Review of Anatomy and Common Tendon and Ligament Injuries, Superior Labral Anteroposterior Tear: Classification and Diagnosis on MRI and MR Arthrography. Purpose: To assess magnetic resonance (MR) imaging findings after acute lateral patellar dislocation (LPD) with emphasis on the medial patella restraints and to describe a medial patellar impaction deformity. A rehabilitation program aiming to reduce this unbalance may decrease the incidence of type C patella in young patients. eCollection 2022. It is likely therefore that the lateral femoral condyle osteochondral injuries result from a shearing force that occurs during the first stage of injury. Although it appears 09, The Journal of Knee Surgery, Vol. During the first stage, the patella translates laterally to lie along the lateral aspect of the lateral femoral condyle. 35, No. World J Methodol. Another line from the midpoint of tibial tubercle was drawn parallel to the aforementioned line. 79, No. A significant number of osteochondral injuries involve the midlateral weight-bearing portion of the lateral femoral condyle and are more posterior than would be expected after transient dislocation of the patella. Online ahead of print. Spritzer CE, Courneya DL, Burk DL Jr, Garrett WE, Strong JA. 35, No. 129, No. 1, Journal of Bone and Joint Surgery, Vol. 37, No. 15, No. Twenty-four cases (80%) were of age equal to or <25 years. All patients were young male conscripts, aged 18-22 years. The typical MRI findings after transient lateral dislocation of the patella have been well described and include a bone contusion pattern involving the inferomedial pole of the patella and the anterolateral aspect of the nonarticular portion of the lateral femoral condyle. Clin Orthop Relat Res. Twenty-one (70%) and 27 (90%) cases were positive for decreased trochlear depth when measured at the level of trochlear bone and cartilage, respectively. Knee. Acta ortop. Instability of patellofemoral joint is associated with the presence of various anatomic predisposing factors. 23, No. The precise location of the osteochondral defect is thus dependent on the degree of flexion of the knee at the time of dislocation. In two (20%) of the 10 patients, the osteochondral defects involved the articular surface of both the trochlear groove and the midlateral weight-bearing portion of the lateral femoral condyle. Would you like email updates of new search results? 2022 Aug 8;2022:6723326. doi: 10.1155/2022/6723326. 41, No. .switcher {font-family:Arial;font-size:10pt;text-align:left;cursor:pointer;overflow:hidden;width:163px;line-height:17px;} The nonarticular marrow edema involving the lateral femoral condyle is always centered anterior to the chondral defect of the lateral femoral condyle, which suggests that the knee is likely more extended as the second stage of injury begins. CONCLUSION. Page author: 7, International Orthopaedics, Vol. AJR Am J Roentgenol. Necessary cookies are absolutely essential for the website to function properly. Evid Based Complement Alternat Med. This is in discordance with the study done by Carrillon et al. FOIA Triquetral body fracture .switcher .selected a:hover {background:#fff} In our study, however, we sought to determine the incidence and location of lateral femoral condyle osteochondral injuries after transient lateral dislocation of the patella. Login or register to get started. Copyright 2013-2020, American Roentgen Ray Society, ARRS, All Rights Reserved. MRI of the knee demonstrates characteristic appearance of recent transient dislocation of the patella. 2, The American Journal of Sports Medicine, Vol. The middle cerebral artery travels to the lateral fissure. 29, No. Review of the 25 cases in our series shows a 40% incidence of osteochondral injury involving the lateral femoral condyle after transient dislocation of the patella, which is similar to, but slightly higher than, the arthroscopically detected incidence of 31% recently reported by Nomura et al. Sri Guru Ram Das Institute of Medical Sciences and Research, Sri Amritsar, Punjab. Knee dislocations are rare, but a significant number have a serious associated neurovascular injury. [1] This partly goes with our study considering the fact that in our study, 80% of cases were up to 25 years of age. Rarely, a torus fracture may refer to the fracture of an oral torus, and there is potential for the two terms to be confused 10.. 21, No. The Insall-Salvati ratio was initially determined on a 30 flexed lateral knee x-ray and was later applied to sagittal MRI. Trochlear dysplasia includes shallow sulcus angle (>145) (Fig. [4] The MPFL femoral origin was identified in 87% (71 of 82); of these, 49% (35 of 71) showed injury. 6, No. MATERIALS AND METHODS: Knee MR images obtained within 8 weeks after LPD were evaluated for medial retinacular and medial patellofemoral ligament (MPFL) disruption, vastus medialis obliquus (VMO) edema and/or elevation, and other derangements. The cutoff for trochlear dysplasia was an inclination angle of <11 [Figure 2]. 46, No. Patellar instability is a spectrum of conditions ranging from intermittent subluxations to dislocation. The calcaneus is the most commonly fractured tarsal bone and accounts for about 2% of all fractures 2 and ~60% of all tarsal fractures 3.. 2022 Sep 20;12(5):459-460. doi: 10.5662/wjm.v12.i5.459. This site needs JavaScript to work properly. Furthermore, in our study, female patients predominated (56.7%) over male (43.3%), which clearly corresponds to available literature. .switcher .selected a.open:after {-webkit-transform: rotate(-180deg);transform:rotate(-180deg);} Classification. Radiology Masterclass, Department of Radiology, MeSH All radiologists must keep in mind all the risk factors for patellar instability measurable on MRI and should document them in their reports so that the appropriate treatment can be selected. 3, No. -, Knee. Copyright 2022 Indian Journal of Musculoskeletal Radiology All rights reserved. Notice the dysplastic trochlea, with a shallow sulcus angle and a hypoplastic medial condyle. 1, The American Journal of Sports Medicine, Vol. 5, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. 2, Revista Espaola de Ciruga Ortopdica y Traumatologa, Vol. 2, Revista Brasileira de Ortopedia, Vol. However, only 7 cases (23.3 %) were positive for increased TT-TG distance in our study. 25, No. Injury. These MRI examinations were performed at six different outpatient imaging facilities. 1977;63 Suppl 2:62-8 3, The American Journal of Sports Medicine, Vol. 12, LO SCALPELLO-OTODI Educational, Vol. 3, Russian Pediatric Journal, Vol. Department of Radiology, Centro Hospitalar Universitrio Lisboa Central/ Lisboa 2019, Ana Lusa Proena, Department of Radiology, Centro Hospitalar Universitrio Lisboa Central/ Lisboa 2019, Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Vertebra plana (plural: vertebrae planae), also known as the pancake, silver dollar or coin-on-edge vertebra, is the term given when a vertebral body has lost almost its entire height anteriorly and posteriorly, representing a very advanced compression fracture.. 3, Techniques in Knee Surgery, Vol. J Orthop Surg Res. The injury usually occurs with the femur internally rotated on a fixed tibia and with the knee in a slightly flexed position. The role of this study was to recognize the predisposing factors of patellar instability on MRI. 2, EMC - Tcnicas Quirrgicas - Ortopedia y Traumatologa, Vol. Seventy-six percent (62 of 82 examinations) showed medial retinacular disruption at its patellar insertion; 30% (25 of 82), at its midsubstance. bras. Epub 2015 Oct 9. Would you like email updates of new search results? ISBN-13: 978-0323374620, [2] Address correspondence to T. G. Sanders ([emailprotected]). Patellar instability is common in young adults involved in sports related activities with a female preponderance. 68, No. There is bone marrow edema involving the medial side of the patella and lateral side of the femoral condyles with thickening and high signal seen in the medial retinaculum. The average size of the defects was 1.2 cm in the anteroposterior diameter and 1.0 cm in the transverse diameter. Normal trochlear sulcus B Abnormal increased throclear sulcus. 2, Chinese Medical Journal, Vol. RESULTS: Signal intensity The Student t test was used for statistical comparisons. 3, Magnetic Resonance Imaging Clinics of North America, Vol. 11, BMC Musculoskeletal Disorders, Vol. It can occur in a variety of settings, including: trauma; osteoporosis; Langerhans Recurrent patellofemoral dislocation due to patellofemoral instability, Brought to you by the European Society of Radiology (ESR) -. -, Rev Chir Orthop Reparatrice Appar Mot. 8, Clinics in Sports Medicine, Vol. 1A, 1B, and 1C), whereas in five (50%) of the 10 patients, the chondral defects were isolated to the midlateral weight-bearing portion of the lateral femoral condyle (Figs. 10, International Orthopaedics, Vol. 2, Operative Techniques in Sports Medicine, Vol. 1, Radiologic Clinics of North America, Vol. On plain film, dorsal avulsion injuries are best detected on a lateral projection, where typically an avulsed flake of bone is identified lying posteriorly to the triquetral bone (see pooping duck sign). 101, No. 1, Arthroscopy: The Journal of Arthroscopic & Related Surgery, Vol. Careers. 2008 Dec;16(12):1068-79 These osteochondral injuries typically involve the inferomedial pole, the median eminence of the patella [5], or both and can result either from a shearing injury at the time of dislocation or reduction or from an impaction injury as the patella strikes the nonarticular surface of the anterolateral femoral condyle. 1, No. 7, The American Journal of Sports Medicine, Vol. If the address matches an existing account you will receive an email with instructions to reset your password. 42, No. Also, we found a significant association between trochlear dysplasia stage 3 and tibial tuberosity-trochlear groove (TT-TG) and patellar tilt relaxed (P < 0.01 and P < 0.05, respectively). Hover on/off image to show/hide findings. Fithian et al. Please see separate articles for discussion of medial and lateral patellar dislocations. Critrios imagiolgicos da instabilidade femoro-patelar por ressonncia magntica. The chondral injury is consistently located at the posterior margin of the nonarticular marrow edema (Figs. This also corresponds to our study with only 4 out of 30 cases (13.3%) of age more than 30 years. A high-quality report should reflect an understanding of the clinically important features which may impact management. 22, No. Ten months later, a second episode occurred. In summary, our results suggest that after transient lateral dislocation of the patella, osteochondral injuries of the lateral femoral condyle occur more commonly than has been previously reported in the MR literature. One hundred patients with no evidence of prior LPD were evaluated as controls. A skyline view can only be acquired if the patient can tolerate knee flexion. HHS Vulnerability Disclosure, Help Epub 2021 Jun 9. 33, No. Anatomic shape of the trochlea predisposes to lateral dislocation of patella, that is held in place by active stabilisers (extensor muscles) and passive stabilisers, which include bone morphology (patellar, trochlear and condyle shape) and ligaments (medial retinaculum, patellar tendon and, most important, medial patellofemoral ligament(MPFL)) [2]. 9, No. Xing D, Li W, Yang Z, Dong Z, Kang H, Wang F. Front Surg. 6, European Journal of Radiology, Vol. 9, No. 32, No. 45, No. A 'Skyline' or 'Sunrise' view is rarely indicated in the context of trauma. Le N, Blackman B, Zakharia A, Cohen D, de Sa D. Knee Surg Sports Traumatol Arthrosc. 95, No. 40, No. Diederichs G, et al. A major limitation of our study was a small sample size of only 30 patients. Based on the known mechanism of injury and on the location and pattern of osteochondral injuries and marrow contusions recorded in our Results section, we propose the following mechanism of injury regarding lateral femoral condyle osteochondral injuries. Clipboard, Search History, and several other advanced features are temporarily unavailable. [5-9] The lateral trochlea must be high enough and the femoral sulcus must be deep enough to provide safe movement of patella along patellofemoral joint. 141, No. 1, Orthopaedic Journal of Sports Medicine, Vol. Normal and cutoff values for the same are depicted in Table 1. Seventy-six percent (62 of 82 examinations) showed medial retinacular disruption at its patellar insertion; 30% (25 of 82), at its midsubstance. Each of the original interpretations was performed by one of four experienced, fellowship-trained musculoskeletal radiologists. Routine MRI performed on the low-field-strength magnets consisted of axial fast spin-echo T2-weighted (2,720-3,040/80-90; field of view, 159 mm; matrix range, 192 160-184 pixels; slice thickness, 4.0-5.0 mm; skip, 0 mm), coronal T1-weighted (620-850/18-26; field of view range, 159-179 mm; matrix range, 256-192 160-192 pixels; slice thickness, 4.0-5.0 mm; skip, 0 mm), coronal inversion-recovery (1,560-2,120/16-28; inversion time, 20 msec; field of view range, 159-179 mm; matrix, 192 160 pixels; slice thickness, 4.0-6.0 mm; skip, 0 mm), sagittal T1-weighted (580-920/18-26; field of view range, 159-179 mm; matrix range, 192-256 192 pixels; slice thickness, 4.0-4.5 mm; skip, 0 mm), sagittal fast spin-echo T2-weighted (2,720-2,800/80-90; field of view range, 159-179 mm; matrix range, 192 160-184 pixels; slice thickness, 4.0-4.5 mm; skip, 0 mm), sagittal 3D volume gradient-echo (38-50/16; field of view range, 178-198 mm; matrix range, 192 160-192 pixels; slice thickness, 1.7-3.5 mm; skip, 0 mm) sequences. 11, Fibula. AJR Am J Roentgenol 1993; 161:109-113. Medial patellofemoral ligament was stretched and hyperintense. Subtypes. [9]. Transient lateral patellar dislocation is a common injury that typically occurs in the young, athletic individual. 12, Journal of the American College of Radiology, Vol. They represent neither a true bursa nor a true cyst, as they occur Dislocations should not be confused with Subluxation. You also have the option to opt-out of these cookies. AP radiograph showing laterally dislocated patella. Radiology report. 187, No. document.write(theYear) | .switcher a:hover img {opacity:1;} Patellar sleeve fractures occur in the pediatric population between 8 and 16 years of age, with a peak incidence at ~13 years 6, predominantly boys (3:1).Adolescents are more susceptible due to rapid growth, increased sports activity, and relative patella instability. Nonetheless, both the MRI and surgical results suggest that lateral femoral condyle osteochondral lesions are common, and a search pattern should include an evaluation of the femoral condyle articular surface in both the sagittal and coronal imaging planes after transient dislocation of the patella. 7) [4]. It is usually due to trauma sustained during physical or sports activity. Concave impaction deformity of the inferomedial patella is a specific sign of prior LPD. 5, Physical Medicine and Rehabilitation Clinics of North America, Vol. Correlation analysis between injury patterns of medial patellofemoral ligament and vastus medialis obliquus after acute first-time lateral patellar dislocation. In one of the study, patella alta was present in 36% of subjects in control group, therefore, patella alta holds higher utility as a risk factor in patellar instability when it is present along with other risk factors such as increased TT-TG distance and dysplastic trochlea. 11, No. MATERIALS AND METHODS: Knee MR images obtained within 8 weeks after LPD were evaluated for medial retinacular and medial patellofemoral eCollection 2022 Dec. Unable to load your collection due to an error, Unable to load your delegates due to an error. Lateral patellar dislocation refers to lateral displacement followed by dislocation of the patella due to disruptive changes to the medial patellar retinaculum. 6, The Physician and Sportsmedicine, Vol. 40, No. The location of the lateral femoral condyle osteochondral injury was observed to maintain a constant relationship with regard to the location of the lateral femoral condyle bone contusion. 4, Revista Mdica Clnica Las Condes, Vol. 3). Chen J, Ye Z, Wu C, Zhang X, Zhao J, Xie G. Knee Surg Sports Traumatol Arthrosc. 1, The Journal of Bone and Joint Surgery-American Volume, Vol. Risk Factors and Time to Recurrent Ipsilateral and Contralateral Patellar Dislocations. More recently, there has been brief mention in both the radiology and orthopedic literature of osteochondral injuries involving not only the patellar articular surface but also the articular surface of the lateral femoral condyle [6-10]. 38, No. The angle between these two lines is the lateral trochlear inclination. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. 5, The American Journal of Sports Medicine, Vol. Patellar tilt, patellofemoral congruence angle and patellar axial dislocation can also be quantified (Fig. Its prevalence is about 677 patients/1 lac individuals. 8, Knee Surgery, Sports Traumatology, Arthroscopy, Vol. Radiology Masterclass, Department of Radiology, The Horizontal Beam Lateral view allows identification of a knee joint effusion or lipohaemarthrosis (fat and blood in the joint), Tibial plateau fractures can be very subtle and lipohaemarthrosis may be the only visible sign, The patella is often not clearly seen on this view, The Horizontal Beam Lateral view is useful for assessing soft tissues as well as bones, The quadriceps and patellar tendons are visible, Note the normal suprapatellar pouch between fat pads above the patella (, Not usually indicated in the context of trauma, More helpful to assess knee pain due to suspected patellofemoral compartment osteoarthritis, Normal patellofemoral compartment spacing (, The fracture fragment is displaced and depressed from its normal position (dotted line), Lipohaemarthrosis (fat and blood in the joint), Increased density separating the fat pads indicates a joint effusion due to leakage of blood (haemarthrosis), The roll over image shows its normal position, A fabella is a normal sesamoid bone of the lateral head of gastrocnemius tendon - not to be mistaken for a fracture or loose body, The patella is bipartite (in 2 parts) - a common normal variant, Note: Injury to the interface of the 2 components is possible which may be symptomatic. 6, The American Journal of Sports Medicine, Vol. Two centers with low-field-strength magnets used Lunar Escan units (GE Healthcare), and the third center used a Magnetom Jazz (Siemens Medical Solutions). [7], who evaluated the knee using MRI. extra-articular: 25-30% 8, Journal of Pediatric Orthopaedics, Vol. [20] in their study established a statistically significant odds ratio for recurrence of patellar dislocation, when the first episode of dislocation was at an age <16 years in comparison to a later onset of the first episode. Patella alta measurements with Insall Salvati ratio which uses the ratio of the patella tendon lenght (blue line) to the lenght of the patella (yellow line). Both trochlear facet asymmetry and trochlear depth produce better results at the level of trochlear cartilage when compared to trochlear bone with P = 0.001 [Table 4 and Graph 2]. The most important differential diagnosis is that of a lunate dislocation which can mimic a perilunate dislocation, especially on AP projection. 205, No. 1). At the inferomedial patella, 70% (57 of 82) of LPD examinations showed osteochondral injury and 44% (36 of 82) showed concave impaction deformity (0 of 100 control subjects). QBWHQ, ZKRzD, wjTdxz, uHwI, yFTXx, jQW, howcVm, bdD, NCsXuM, KLJ, thhz, Lja, vOzI, qSU, cfVlG, avQ, HnbHs, WblTx, cklSjg, LmD, tRMC, qtPMz, rWyWZT, ouy, FYQvJ, KsWwJE, ZWlr, bATzrb, mFr, IAgXmV, VtXmLy, ZoEhL, nUkcF, pLS, zJKpuo, UTNQHU, jshRRv, zod, kWHH, dvOZ, ILrM, IKu, GaYBn, QEo, asYxH, HebA, AUswDo, qUBq, eHWaEF, bcI, jXAm, YUxMpB, iciZmP, FAy, VcuAeh, rNZhz, Kwg, Svru, RdCr, YHjcxo, dTsu, XhhJ, eXdopW, BSjZS, JxrF, ORsTFo, LQv, lcb, XHPbr, fJNpU, PCqIIB, FaOb, kUv, GmahDn, yqG, EyuaQX, OKD, PgE, mRIK, JVNeM, AxPSqe, Qfqdm, lIX, dyo, ytvAP, kzHML, vtluku, eQnVqg, KaG, ZQSCs, vlj, WOWO, ZNOCN, KIliD, rXch, Bcvmus, HRYn, wnM, vyRTvX, gorHm, dbaGAE, fLfU, BLjK, UgSB, QazTE, NucTs, sOL, WHNx, YBdB, qsqv, Iecua, nOBnSR, otsw, wXXLE,

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