Magnetic resonance imaging of the knee

The Role of Magnetic Resonance Imaging in the Evaluation of Knee Pain

Objectives This study aimed to characterize and compare the features of traumatic and non-traumatic lesions causing knee pain through magnetic resonance imaging (MRI). Method The study was conducted at a tertiary care center, with data sourced from patients visiting the outpatient and in-patient departments. It involved a descriptive cross-sectional research design focusing on patients referred for knee MRI scanning. The sample size was calculated using Cochran's formula as 112 for symptomatic patients with knee pain with a 95% confidence interval. The MRI findings in 112 patients were analyzed and associated with a history of trauma. Results The average age recorded was 35.38 years. Females made up 41.07% (n=46) of the sample, while males accounted for 58.93% (n=66). Among the participants, the majority (n=82; 71.43%) had a history of trauma, and the most common MRI finding was joint effusion (n=74; 66.1%). The second most common was anterior cruciate ligament (ACL) injuries (n=71; 63.4%), followed by meniscus injury (n=40; 35.71%). The study confirms that those with history of trauma are at a higher risk (p<0.05) of sustaining injuries like meniscus and ACL tears, collateral ligament damage, bone contusions, chondromalacia patella, and joint effusion. Conclusion In conclusion, the consistency of our findings with existing studies reinforces the pivotal role of MRI in the evaluation of knee pain. Despite its limitations, including cost and accessibility, MRI remains a gold standard for diagnosing a wide range of knee pathologies, offering unparalleled detail and accuracy that significantly enhance clinical decision-making and patient outcomes.

Should We Prefer Magnetic Resonance Imaging to Physical Examination in Meniscal Tears

The aim of this study was to compare the sensitivity, specificity, accuracy, positive and negative predictive values of magnetic resonance imaging (MRI), and clinical examination in the diagnosis of meniscus tears with the findings obtained from the knee joint arthroscopy. A retrospective study was made of 452 patients who underwent knee arthroscopy due to meniscus tears between 2012 and 2017. Physical examination was performed using the Thessaly's, McMurray's, and Joint line tenderness tests (JLTT). On preoperative MRI, medial meniscal tears were observed in 292 patients, lateral meniscal tears in 96 patients, and medial and lateral meniscal tears in 64 patients. According to the arthroscopy results, 284 patients had medial meniscal tears, 108 patients had lateral meniscal tears, and 60 patients had medial and lateral meniscal tears. Sensitivity and specificity of the JLTT was determined as 93 and 86% respectively for medial meniscal tears and 94 and 89% for lateral meniscal tears. The McMurray's test was 60% sensitive, 68% specific for medial meniscal tears (MMT), and 73% sensitive and 68% specific for lateral meniscus tears (LMT). The Thessaly's test was 93% sensitive and 87% specific for medial meniscal tears; and 94% sensitive and 88% specific for LMT. Compared with the arthroscopic findings, MRI was observed to have sensitivity of 94% for MMT and 84% for LMT. For specificity, the values were 89% for MMT and 91% for LMT. Accuracy was 89% for MMT and 86% for LMT. In comparison with the arthroscopic findings, the triple test was determined to have sensitivity of 92% for MMT and 89% for LMT. The specificity was 88% for MMT and 91% for LMT. The results of this study showed that a combination of selected physical examination methods is as sensitive as MRI in the diagnosis of meniscus tears.

Management of traumatic meniscus tears: the 2019 ESSKA meniscus consensus

PURPOSE

The importance of meniscus integrity in the prevention of early osteoarthritis is well known, and preservation is accepted as the primary goal. The purpose of the ESSKA (European Society for Sports Traumatology, Knee Surgery and Arthroscopy) European consensus on traumatic meniscus tears was to provide recommendations for the treatment of meniscus tears based on both scientific evidence and the clinical experience of knee experts.

METHODS

Three groups of surgeons and scientists elaborated and ratified the so-called formal consensus process to define the recommendations for the management of traumatic meniscus tears. A traumatic meniscus tear was defined as a tear with an acute onset of symptoms caused by a sufficient trauma. The expert groups included a steering group of eight European surgeons and scientists, a rating group of another nineteen European surgeons, and a peer review group. The steering group prepared twenty-seven question and answer sets based on the scientific literature. The quality of the answers received grades of A (a high level of scientific support), B (scientific presumption), C (a low level of scientific support) or D (expert opinion). These question and answer sets were then submitted to and evaluated by the rating group. All answers were scored from 1 (= totally inappropriate) to 9 (= totally appropriate) points. Thereafter, the comments of the members of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the finalized question and answer sets were submitted for final review by the peer review group composed of representatives of the ESSKA-affiliated national societies. Eighteen representatives replied.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the treatment of traumatic meniscus tears. Of the 27 questions, only one question received a grade of A (a high level of scientific support), and another received a grade of B (scientific presumption). The remaining questions received grades of C and D. The mean rating of all questions by the rating group was 8.2 (95% confidence interval 8.1-8.4). A general agreement that MRI should be performed on a systematic basis was not achieved. However, MRI was recommended when arthroscopy would be considered to identify concomitant pathologies. In this case, the indication for MRI should be determined by a musculoskeletal specialist. Based on our data, stable left in situ lateral meniscus tears appear to show a better prognosis than medial tears. When repair is required, surgery should be performed as early as possible. Evidence that biological enhancement such as needling or the application of platelet-rich plasma would improve healing was not identified. Preservation of the meniscus should be considered as the first line of treatment because of an inferior clinical and radiological long-term outcome after partial meniscectomy compared to meniscus repair.

DISCUSSION

The consensus was generated to present the best possible recommendations for the treatment of traumatic meniscus tears and provides some groundwork for a clinical decision-making process regarding the treatment of meniscus tears. Preservation of the meniscus should be the first line of treatment when possible, because the clinical and radiological long-term outcomes are worse after partial meniscectomy than after meniscus preservation. The consensus clearly states that numerous meniscus tears that were considered irreparable should be repaired, e.g., older tears, tears in obese patients, long tears, etc. LEVEL OF EVIDENCE: II.

The popliteal fibular ligament in acute knee trauma: patterns of injury on MR imaging

OBJECTIVE

To describe the patterns of injury associated with injury to the popliteofibular ligament injury.

MATERIALS AND METHODS

A retrospective review was performed of 180 MRI scans undertaken for acute knee trauma. Scans were excluded if the time of injury was over 4 weeks from the time of the scan, or if there was a history of septic arthritis, inflammatory arthropathy, previous knee surgery, or significant artefact. An agreed criterion for assessing the structures of the posterolateral ligamentous complex was defined and in each scan, the popliteofibular ligament (PFL) was scored as normal or injured. The menisci, ligaments, and tendons of each knee were also assessed.

RESULTS

The mean age was 25.7 years (range, 9-65 years) and 72.2% (n = 130) patients were male. The PFL was injured in 36 cases (20%). There is a significant association between PFL injury and ACL rupture (p = 0.0001), ITB injury (p = 0.0001), PCL injury (p = 0.0373), in addition to associations with injury to other posterolateral corner structures including the lateral collateral ligament (p = 0.0001), biceps femoris tendon (p = 0.0014), and popliteus tendon (p = 0.0014). Of our series of PFL injuries, nine cases (25%) were associated with further injuries of posterolateral corner structures and in 27 cases (75%) the PFL was the only posterolateral corner structure torn.

CONCLUSIONS

PFL injury is not uncommon in acute knee trauma and is associated with significant internal derangement of the knee, especially anterior cruciate ligament rupture, ITB sprain, and injury to other structures within the posterolateral corner.

The iliotibial band in acute knee trauma: patterns of injury on MR imaging

OBJECTIVE

To delineate the spectrum of knee injuries associated with sprains and tears of the distal iliotibial band (ITB).

MATERIALS AND METHODS

A retrospective review of 200 random MRI scans undertaken for acute knee trauma was performed. Scans were excluded if there was a history of injury over 4 weeks from the time of the scan, septic arthritis, inflammatory arthropathy, previous knee surgery, or significant artefact. In each scan, the ITB was scored as normal, minor sprain (grade 1), severe sprain (grade 2), and torn (grade 3). The menisci, ligaments, and tendons of each knee were also assessed.

RESULTS

The mean age was 27.4 years (range, 9-69 years) and 71.5% (n = 143) of the patients were male. The ITB was injured in 115 cases (57.5%). The next most common soft tissue structure injured was the anterior cruciate ligament (ACL) in 53.5% of cases (n = 107). Grade 1 ITB injury was seen in 90 of these 115 cases (45%), grade 2 injury in 20 cases, and grade 3 injury in only five cases. There is a significant association between ITB injury and ACL rupture (p < 0.05), as well as acute patellar dislocation (p < 0.05). There were ten cases of significant posterolateral corner injury, and all were associated with ITB injury, including four ITB tears. Only two cases of isolated ITB injury were seen (1%).

CONCLUSIONS

ITB injury is common in acute knee trauma and is associated with significant internal derangement of the knee, especially cruciate ligament rupture, posterolateral corner injury, and patellar dislocation.

Normal anatomical variants of the menisci and cruciate ligaments that may mimic disease

There are many normal anatomical variants of the knee joint. Some are common and others are rare. With continuing improvements in the spatial resolution of MRI, smaller variants are more clearly demonstrated and can be mistaken for disease. They can all be differentiated from pathological conditions by understanding their anatomy and key differentiating features. This review compares normal variants of the menisci and cruciate ligaments with the pathological disorders that can mimic them.

Manual khalifa therapy improves functional and morphological outcome of patients with anterior cruciate ligament rupture in the knee: a randomized controlled trial

Rupture of the anterior cruciate ligament (ACL) is a high incidence injury usually treated surgically. According to common knowledge, it does not heal spontaneously, although some claim the opposite. Regeneration therapy by Khalifa was developed for injuries of the musculoskeletal system by using specific pressure to the skin. This randomized, controlled, observer-blinded, multicentre study was performed to validate this assumption. Thirty patients with complete ACL rupture, magnetic resonance imaging (MRI) verified, were included. Study examinations (e.g., international knee documentation committee (IKDC) score) were performed at inclusion (t 0). Patients were randomized to receive either standardised physiotherapy (ST) or additionally 1 hour of Khalifa therapy at the first session (STK). Twenty-four hours later, study examinations were performed again (t 1). Three months later control MRI and follow-up examinations were performed (t 2). Initial status was comparable between both groups. There was a highly significant difference of mean IKDC score results at t 1 and t 2. After 3 months, 47% of the STK patients, but no ST patient, demonstrated an end-to-end homogeneous ACL in MRI. Clinical and physical examinations were significantly different in t 1 and t 2. ACL healing can be improved with manual therapy. Physical activity can be performed without pain and nearly normal range of motion after one treatment of specific pressure.

Use of knee magnetic resonance imaging by primary care physicians in patients aged 40 years and older

BACKGROUND

Criteria are needed for primary care providers such that they can evaluate age-related knee pain in a cost-effective manner. This study examined (1) in what percentage of patients are appropriate radiographic views of the knee ordered before magnetic resonance imaging (MRI) for knee pain, (2) specialists' retrospective evaluation for appropriate utilization of MRI in knee pain, and (3) in what manner would the MRIs have altered diagnosis and management of knee disorders.

HYPOTHESIS

Primary care providers underuse appropriate radiographs-especially, flexion weightbearing posteroanterior films-and overuse MRIs when evaluating older patients with knee pain.

STUDY DESIGN

Case control.

METHODS

The authors performed a retrospective analysis of 100 patients older than 40 years with knee MRIs. Patient encounters with primary care physicians were reviewed. Given available information, specialists then formulated a pre- and post-MRI diagnosis and treatment plan and indicated whether the MRI would have altered their treatment.

RESULTS

Only 12 of 100 MRIs would have been ordered by an orthopaedist given the documented data. No MRIs would have been ordered in the 19 patients aged 60 years or older. Among 44 radiographs ordered, only 7 were flexion weightbearing. The most common pre-MRI diagnoses made by primary care providers were joint pain (22%) and meniscus injury (24%); the most common post-MRI diagnoses were osteoarthritis (40%) and degenerative meniscus injury (23%). In contrast, the 2 most common pre- and post-MRI diagnoses by specialists were osteoarthritis (28% and 37%, respectively) and degenerative meniscus injury (23% and 24%, respectively). Also, referrals to specialists increased from 9% pre-MRI to 76% post-MRI.

CONCLUSION

Primary care providers may be overusing knee MRIs and underusing flexion weightbearing posteroanterior radiographs in patients older than 40 years with knee pain.

CLINICAL RELEVANCE

Primary care providers should strongly consider not ordering knee MRI in patients with radiographic evidence of degenerative changes.

Accuracy of routine magnetic resonance imaging in meniscal and ligamentous injuries of the knee: comparison with arthroscopy

The aim of this study was to detect the accuracy of routine magnetic resonance imaging (MRI) done in different centres and its agreement with arthroscopy in meniscal and ligamentous injuries of the knee. We prospectively examined 70 patients ranging in age between 22 and 59 years. History taking, plain X-ray, clinical examination, routine MRI and arthroscopy were done for all patients. Sensitivity, specificity, accuracy, positive and negative predictive values, P value and kappa agreement measures were calculated. We found a sensitivity of 47 and 100%, specificity of 95 and 75% and accuracy of 73 and 78.5%, respectively, for the medial and lateral meniscus. A sensitivity of 77.8%, specificity of 100% and accuracy of 94% was noted for the anterior cruciate ligament (ACL). We found good kappa agreements (0.43 and 0.45) for both menisci and excellent agreement (0.84) for the ACL. MRI shows high accuracy and should be used as the primary diagnostic tool for selection of candidates for arthroscopy.

LEVEL OF EVIDENCE

4.