The Role of Clinical Examination in Predicting Relevant MRI Findings in Acute Knee Injuries: A Retrospective Study

Abstract

The objective of this study was to delineate the usefulness of clinical examination and magnetic resonance imaging (MRI) in acute knee injuries. We aim to establish whether the time period post acute knee injury is related to the diagnostic accuracy of clinical examination and to investigate the strength of specific clinical examination findings in predicting a clinically relevant MRI abnormality. Seventy patients were referred to fracture clinic with an acute knee injury who subsequently went on to be investigated with MRI over 12 months. These patients were retrospectively analyzed looking at the time period they were reviewed, the components that were assessed at physical examination, and the results of their eventual MRI scan looking for any correlation. A greater proportion of patients who were examined at 2 weeks had relevant positive findings on MRI scan, = 0.03. Range of movement and lateral joint line tenderness were not associated with a positive MRI scan at any period after injury. The presence of a moderate to large effusion wasnot associated with an MRI abnormality if the examination was within 2 weeks of injury but was if present 2 weeks after injury, = 0.0001. Range of movement should not form part of the decision making on whether an injury should be investigated with MRI. Joint effusion in isolation within 2 weeks after injury should not be an indication for MRI but a repeat clinical examination in 2 weeks, where if still present, should be investigated with MRI.

The diagnostic accuracy of clinical tests for anterior cruciate ligament tears are comparable but the Lachman test has been previously overestimated: a systematic review and meta-analysis

“…Isolated ACL tears were analysed in seven studies [ 6 , 9 , 11 , 20 , 25 , 42 , 49 ], whereas ten studies recruited patients with an isolated ACL tear or combined ACL tear and meniscal injury [ 8 , 18 , 20 , 22 , 26 , 39 , 41 , 62 , 72 , 75 ]. The spectrum of conditions was not specified or unclear in eight studies [ 12 , 18 , 33 , 38 , 43 – 45 , 57 ]. Patient cohorts with complete ACL tears only were analysed by ten studies [ 6 , 8 , 11 , 12 , 20 , 25 , 39 , 42 , 44 , 75 ], partial ACL tears only were analysed in two studies [ 22 , 42 ], combined complete and partial ACL tears in nine studies [ 9 , 18 , 22 , 26 , 38 , 43 , 45 , 49 , 75 ].…”

“…The average age of patients ranged from 21 [ 8 ] to 45 [ 6 , 39 ] with seven studies including patients below 16 years of age [ 8 , 9 , 20 , 33 , 45 , 49 , 62 ]. Time from injury was not defined in three studies [ 38 , 45 , 72 ] while acute, subacute and/or chronic injuries were included in the same cohort in six studies [ 9 , 33 , 41 , 43 , 57 , 75 ]; three studies described patients as acute yet did not specify time from injury [ 8 , 49 ] or provided only the average time [ 62 ].…”

“…Screening of previous systematic reviews identified 24 additional citations. Screening titles and abstracts of the citations against the inclusion and exclusion criteria identified 80 studies for potential inclusion with in‐depth scrutiny of each article generating 24 studies for final inclusion in this review [6, 8, 9, 11, 12, 18, 20, 22, 25, 26, 33, 38, 39, 41–45, 49, 54, 57, 62, 72, 75]. Selection of studies is summarised in the PRISMA flow diagram (Fig.…”

“…Only two studies [6, 8] were not considered at risk of bias (Table 3). One study was an RCT [6], seven studies had a prospective design [8, 42, 43, 49, 54, 72, 75] and 14 assessed patients retrospectively [9, 12, 18, 20, 22, 26, 33, 38, 39, 41, 44, 45, 57, 62]. Arthroscopy and/or arthrotomy was used as a gold standard in 17 studies [6, 8, 9, 11, 12, 18, 20, 22, 25, 38, 39, 43, 44, 54, 57, 62, 72] with MRI reported as a reference standard in seven studies [26, 38, 41, 42, 45, 49, 75].…”

“…The number of patients in cohorts extracted from studies ranged from six [22] to 217 [22]. The average age of patients ranged from 21 [8] to 45 [6,39] with seven studies including patients below 16 years of age [8,9,20,33,45,49,62]. Time from injury was not defined in three studies [38,45,72] while acute, subacute and/or chronic injuries were included in the same cohort in six studies [9,33,41,43,57,75]; three studies described patients as acute yet did not specify time from injury [8,49] or provided only the average time [62].Each study has been screened for risk of bias based on 4 criteria of patient selection, index test, reference standard and flow and timing.…”