MRI as the optimal imaging modality for assessment and management of osteochondral fractures and loose bodies following traumatic patellar dislocation: a systematic review

Abstract

PurposeTo assess the imaging modalities used for diagnosis, as well as the management decisions of patients with osteochondral fractures (OCF) and loose bodies following traumatic patellar dislocation. MethodsAccording to the Preferred Reporting Items for Systematic Review and Meta‐analyses (PRISMA), MEDLINE, EMBASE, Web of Science, and PubMed were searched for results from January 1, 2000, to May 18, 2021, in two subsequent searches for English language studies that presented data on traumatic patellar dislocation. Quality of selected papers was assessed using the Methodological Index for Non‐Randomised Studies (MINORS) and the Risk of Bias (RoB) 2.0 protocol. Results were qualitatively synthesised, and descriptive statistics were calculated. ResultsForty studies totalling 3074 patients (1407 females) were included for the analysis. The mean age was 18.9 years (range 0–69). The population included 2446 first‐time dislocations. The imaging modalities used were: 71.1% MRI, 52.6% plain radiography, 12.1% CT, and 0.68% ultrasound. In the 25 studies that reported the number of OCF, a total of 38.3% of patients were found to have OCF. 43.3% of patients with a first‐time dislocation, and 34.7% of patients with previous dislocations, had at least one OCF. In the included paediatric studies (maximum age ≤ 18), the presence of OCF was detected by plain radiography in 10.1% of patients, MRI in 76.6% of patients, and CT in 89.5% of patients. For management of an OCF, the surgical options include fixation for larger pieces, excision for smaller pieces, and conservative management on a case‐by‐case basis. ConclusionsBased on the current available evidence, assessment and management of patellar dislocations and subsequent OCFs vary, with radiography and MRI as the main imaging modalities on presentation and particular benefit for MRI in the paediatric population. Findings from this study suggest the highest rate of OCF detection with MRI, and thus, surgeons should consider routinely ordering an MRI in patients with first‐time patellar dislocation. Regarding management of OCFs, the main indication for fixation was large fragments, while smaller and poor‐quality fragments are excised. Few studies choose conservative management of OCFs due to later requirements for surgical management. Future work should focus on large, high‐quality studies, and implementation of randomised control trials to form guidelines for imaging patellar dislocations and management of OCFs. Level of evidenceLevel IV.

Consensus-Based Guidelines for Management of First-Time Patellar Dislocation in Adolescents

“…Though a computed tomography scan is an option for assessment, it is not recommended in the pediatric population due to the increased risk of radiation, inferior soft tissue contrast, and limited additional information compared with an MRI. 18,11 After an acute episode of first-time patellar dislocation, the type and duration of immobilization is controversial. 9,10,17,19 Rigid and long-term immobilization can allow injured tissues to heal but can lead to muscle atrophy, joint stiffness, and cartilage degeneration.…”

“…In the presence of traumatic hemarthrosis of the knee, an MRI evaluation is justified to evaluate for osteochondral fractures and associated injuries. Though a computed tomography scan is an option for assessment, it is not recommended in the pediatric population due to the increased risk of radiation, inferior soft tissue contrast, and limited additional information compared with an MRI 18,11 …”

Management of the first episode of traumatic patellar dislocation: an international survey

“…The recurrence rate following conservative management is approximately 25%; therefore, receiving proper treatment after the first episode of patellar dislocation has a considerable impact on the outcome [7, 20, 22, 24]. Although patellar dislocation is amongst the most prevalent first‐time knee disorders, the management of patients following the first patellar dislocation condition remains unclear and controversial [2, 17, 18].…”

Ultrasound is more reliable than clinical tests to both confirm and rule out pathologies of the long head of the biceps: a systematic review and meta-analysis

“…The disadvantages of clinical tests and ultrasound are that they depend on the experience of the observer [11], and unlike 3D imaging, cannot be reinterpreted by other observers if the patient is not physically present [37]. As such, inexperienced clinicians may struggle to correctly classify test results as positive or negative in borderline cases [42], or to differentiate between a tendinopathy or partial tear.…”