The diagnostic validity of magnetic resonance imaging in acute knee injuries with hemarthrosis. A single-blinded evaluation in 69 patients using high-field MRI before arthroscopy

1H NMR Metabolic Profiling of Synovial Fluid from Patients with Anterior Cruciate Ligament Tears and Hemarthrosis

OBJECTIVE

To compare the metabolic profiles of synovial fluid (SF) from patients with anterior cruciate ligament tears and hemarthrosis (HA) with that of normal controls, using ¹H NMR spectroscopy (NMRS).

METHODS

Synovial fluid was collected from eleven patients undergoing arthroscopic debridement within fourteen days following an anterior cruciate ligament (ACL) tear and hemarthrosis. Ten additional SF samples were obtained from the knees of osteoarthritis-free volunteers to serve as normal controls. The relative concentrations of twenty-eight endogenous SF metabolites (hydroxybutyrate, acetate, acetoacetate, acetone, alanine, arginine, choline, citrate, creatine, creatinine, formate, glucose, glutamate, glutamine, glycerol, glycine, histidine, isoleucine, lactate, leucine, lysine, phenylalanine, proline, pyruvate, threonine, tyrosine, valine, and the mobile components of glycoproteins and lipids) were evaluated using NMRS and quantified using CHENOMX metabolomics analysis software. Mean differences between groups were evaluated with t-tests controlling for multiple comparisons at an overall error rate of 0.10.

RESULTS

Statistically significant increases in the levels of glucose, choline, the branched-chain amino acids leucine, isoleucine, and valine, and the mobile components of N-acetyl glycoproteins and lipids were observed in ACL/HA SF as compared with normal controls; lactate levels were reduced.

CONCLUSIONS

Marked changes occur in the metabolic profiles of human knee fluid following ACL injury and hemarthrosis, suggestive of increased demand and accompanying inflammatory response; potentially increased lipid and glucose metabolism; and possible hyaluronan degradation within the joint following trauma.

Imaging of the medial collateral ligament of the knee: a systematic review

INTRODUCTION

The primary aim of this investigation was to systematically review relevant literature of various imaging modalities (magnetic resonance imaging (MRI), stress radiography and ultrasonography) in the assessment of patients with a medial collateral ligament (MCL) injury.

MATERIALS AND METHODS

A systematic literature review of articles indexed in PubMed and Cochrane library was performed. Original research reporting data associated with medial gapping, surgical, and clinical findings associated with MCL injuries were considered for inclusion. The methodological quality of each inclusion was also assessed using a verified tool.

RESULTS

Twenty-three imaging studies (magnetic resonance imaging (MRI) n = 14; ultrasonography n = 6; radiography n = 3) were ultimately included into the review. A total of 808 injured, and 294 control, knees were assessed. Interobserver reliabilities were reported in radiographic and ultrasonographic investigations with almost perfect agreement. MRI studies demonstrated agreement ranging between substantial to almost perfect. Intraobserver reliability was only reported in radiographic studies pertinent to medial gapping and was found to be almost perfect. Correlation of MRI with clinical findings was moderate to strong (65-92%). Additionally, MRI imaging was more sensitive in the detection of MCL lesions when compared to clinical examination. However, when compared to surgical findings, MRI underestimated the grade of instability in up to 21% of cases. Furthermore, MRI showed relatively inferior performance in the identification of the exact MCL-lesion location when compared to surgical findings. Interestingly, preoperative clinical examination was slightly inferior to stress radiography in the detection of MCL lesions. However, clinical testing under general anaesthesia performed similar to stress radiography. The methodological quality analysis showed a low risk of bias regarding patient selection and index testing in each imaging modality.

CONCLUSION

MRI can reliably diagnose an MCL lesion but demonstrates limitations in its ability to predict the specific lesion location or grade of MCL instability. Ultrasonography is a widely available, radiation free modality, but is rarely used in clinical practice for detecting MCL lesions and clinical or surgical correlates are scarce. Stress radiography findings correlate with surgical findings but clinical correlations are missing in the literature.

LEVEL OF EVIDENCE

IV.

Treatment of Combined Injuries to the ACL and the MCL Complex: A Consensus Statement of the Ligament Injury Committee of the German Knee Society (DKG)

Background:

Different indications and treatment options for combined injuries to the anterior cruciate ligament (ACL) and medial collateral ligament complex (MCL) are not clearly defined.

Purpose:

To perform a modified Delphi process with the Committee for Ligament Injuries of the German Knee Society (DKG) in order to structure and optimize the process of treating a combined injury to the ACL and MCL.

Study Design:

Consensus statement.

Methods:

Scientific questions and answers were created based on a comprehensive literature review using the central registers for controlled studies of Medline, Scopus, and Cochrane including the terms medial collateral ligament, anterior cruciate ligament, MCL, ACL, and outcome used in various combinations. The obtained statements passed 3 cycles of a modified Delphi process during which each was readjusted and rated according to the available evidence (grades A-E) by the members of the DKG Ligament Injuries Committee and its registered guests.

Results:

The majority of answers, including several questions with >1 graded answer, were evaluated as grade E (n = 16) or C (n = 10), indicating that a low level of scientific evidence was available for most of the answers. Only 5 answers were graded better than C: 3 answers with a grade of A and 2 answers with a grade of B. Only 1 answer was evaluated as grade D. An agreement of >80% (range, 83%-100%) among committee members was achieved for all statements.

Conclusion:

The results of this modified Delphi process offer a guideline for standardized patient care in cases of combined injuries to the ACL and MCL.

Ultrasound-based examination of the medial ligament complex shows gender- and age-related differences in laxity

PURPOSE

Ultrasound (US) examination of the medial joint space of the knee has played a subordinate diagnostic role up till now. The purpose of the present study was to describe mean values of medial joint width and to investigate the impact of gender, age, and body mass index (BMI) on medial joint laxity in healthy knees using modern, dynamic US in a standardized fashion in unloaded and standardized loaded conditions.

METHODS

A total of 65 subjects with 79 healthy knees were enrolled in this study. All volunteers underwent clinical examination of the knee. The medial knee joint width was determined using US in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton, daN) conditions using a specific device. Mean values were described and correlations between medial knee joint width and gender, age, and BMI were assessed.

RESULTS

Thirty-two females and 33 males were enrolled in this study. The mean medial joint width in 0° unloaded was 5.7 ± 1.2 mm and 7.4 ± 1.4 mm loaded. In 30° of knee flexion, the mean medial joint width was 6.1 ± 1.1 mm unloaded and 7.8 ± 1.2 mm loaded. The average change between unloaded and loaded conditions in 0° was 1.7 ± 1.0 mm and in 30° 1.7 ± 0.9 mm. A significant difference between genders was evident for medial joint width in 0° and 30° of flexion in unloaded and loaded conditions (p < 0.05). With rising age, a significant increased change of medial joint space width between unloaded and loaded conditions could be demonstrated in 0° (p = 0.032). No significant correlation between BMI and medial joint width in US could be found.

CONCLUSION

Mean values of medial joint width in unloaded and standardized loaded conditions using a fixation device could be demonstrated. Based on the results of this study, medial knee joint width in US is gender- and age-related in healthy knees. These present data may be useful for evaluating patients with acute or chronic pathologies to the medial side of the knee.

LEVEL OF EVIDENCE

III.

Lateral meniscus posterior root tear in anterior cruciate ligament injury can be detected using MRI-specific signs in combination but not individually

PURPOSE

The purpose of this study was to evaluate (1) the diagnostic value of using single and multiple magnetic resonance imaging (MRI) findings for lateral meniscus posterior root tear (LMPRT) detection in anterior cruciate ligament (ACL) injury and (2) the influence of time from ACL injury to MRI assessment on LMPRT detection. Finally, we investigated the relationship between LMPRT and bone bruising.

METHODS

In all, 231 knees with ACL injury, 32 with LMPRT, were retrospectively assessed. Cases were evaluated for LMPRT based on the cleft, ghost, and truncated triangle signs, used individually or in combination. To assess the influence of the timing of the MRI assessment on LMPRT detection, we also evaluated the overall sensitivity, specificity, and accuracy in cases in which MRI was performed within 2 weeks of injury. The number of condyles with bone bruising was assessed and then compared between patients with and without LMPRT.

RESULTS

Although the sensitivity and specificity of the three signs individually were 34.4-65.6% and 94.0-97.0%, when at least one of these signs was positive, the sensitivity and specificity were 84.4% and 90.5%, respectively. However, the diagnostic value of each sign when MRI was performed within 2 weeks of injury was lower than the overall value. There was a significant difference in the number of condyles with bone bruising between the LMPRT (3 ± 1) and non-LMPRT (2 ± 2) groups.

CONCLUSIONS

Although the sensitivity of each sign for LMPRT was low, LMPRT could be detected adequately if these signs were used in combination. Therefore, surgeons should detect LMPRT using these three signs in combination, not individually.

LEVEL OF EVIDENCE

IV.

Is Diagnostic Arthroscopy at the Time of Medial Patellofemoral Ligament Reconstruction Necessary?

Background:

Although medial patellofemoral ligament (MPFL) reconstruction is well described for patellar instability, the utility of arthroscopy at the time of stabilization has not been fully defined.

Purpose:

To determine whether diagnostic arthroscopy in conjunction with MPFL reconstruction is associated with improvement in functional outcome, pain, and stability or a decrease in perioperative complications.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients who underwent primary MPFL reconstruction without tibial tubercle osteotomy were reviewed (96 patients, 101 knees). Knees were divided into MPFL reconstruction without arthroscopy (n = 37), MPFL reconstruction with diagnostic arthroscopy (n = 41), and MPFL reconstruction with a targeted arthroscopic procedure (n = 23). Postoperative pain, motion, imaging, operative findings, perioperative complications, need for revision procedure, and postoperative Kujala scores were recorded.

Results:

Pain at 2 weeks and 3 months postoperatively was similar between groups. Significantly improved knee flexion at 2 weeks was seen after MPFL reconstruction without arthroscopy versus reconstruction with diagnostic and reconstruction with targeted arthroscopic procedures (58° vs 42° and 48°, respectively; P = .02). Significantly longer tourniquet times were seen for targeted arthroscopic procedures versus the diagnostic and no arthroscopic procedures (73 vs 57 and 58 min, respectively; P = .0002), and significantly higher Kujala scores at follow-up were recorded after MPFL reconstruction without arthroscopy versus reconstruction with diagnostic and targeted arthroscopic procedures (87.8 vs 80.2 and 70.1, respectively; P = .05; 42% response rate). There was no difference between groups in knee flexion, recurrent instability, or perioperative complications at 3 months. Diagnostic arthroscopy yielded findings not previously appreciated on magnetic resonance imaging (MRI) in 35% of patients, usually resulting in partial meniscectomy.

Conclusion:

Diagnostic arthroscopy with MPFL reconstruction may result in findings not previously appreciated on MRI. Postoperative pain, range of motion, and risk of complications were equal at 3 months postoperatively with or without arthroscopy. Despite higher Kujala scores in MPFL reconstruction without arthroscopy, the relationship between arthroscopy and patient-reported outcomes remains unclear. Surgeons can consider diagnostic arthroscopy but should be aware of no clear benefits in patient outcomes.

Comparison of clinical, MRI and arthroscopic assessments of chronic ACL injuries, meniscal tears and cartilage defects

PURPOSE

The aim of this study was to compare the accuracy of clinical examination to that of MRI evaluated by two independent radiologists for the diagnosis of meniscal tears and chronic anterior cruciate ligament injuries and to assess the MRI accuracy in the diagnosis of cartilage defects.

METHODS

Seventy-six consecutive patients with suspected intra-articular knee pathology were prospectively evaluated by objective examination, 1.5 T MRI, re-examined by trained radiologist and arthroscopy. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value were calculated. Agreement analysis with kappa (К) coefficient values was performed for meniscal and ACL tears.

RESULTS

No differences were found between diagnostic accuracy of clinical examination, the first and second MRI reports in diagnosis of medial meniscus (84 vs 96 vs 97 %) and anterior cruciate ligament injuries (93 vs 78 vs 89 %). For the lateral meniscal tears, the accuracy of the second radiologist was significantly higher than those of the first (96 vs 75 %; p < 0.01) and clinical examination (96 vs 86 %; p = 0.02). High diagnostic values were obtained for the diagnosis of full-thickness chondral defects with sensitivity of 100 %, specificity of 95 % and accuracy of 95 %.

CONCLUSION

Clinical and MRI evaluations have no differences in the diagnosis of medial meniscus and anterior cruciate ligament injuries. A trained radiologist obtained better sensitivity, specificity and accuracy in the diagnosis of lateral meniscus. 1.5 T MRI does not represent the technique of choice in the evaluation of chondral defect but demonstrated high diagnostic accuracy for detection of full-thickness chondral defects.

LEVEL OF EVIDENCE

Diagnostic prospective study, Level II.

Risk Factors of False-Negative Magnetic Resonance Imaging Diagnosis for Meniscal Tear Associated With Anterior Cruciate Ligament Tear

PURPOSE

To identify risk factors that predict false-negative magnetic resonance imaging (MRI) diagnosis for meniscal tear coincident with anterior cruciate ligament injury using multivariate logistic regression.

METHODS

We reviewed the medical records of consecutive patients who underwent arthroscopic anterior cruciate ligament reconstruction from January 2006 through December 2014. Exclusion criteria were no meniscal tear or incomplete tear less than 10 mm in length, delay to surgery from initial injury more than 1 year, delay to surgery from preoperative MRI more than 4 weeks, revisions, fracture histories, and multiple ligament injuries. According to preoperative MRI diagnosis, the meniscal tears were sorted into true-positive MRI and false-negative MRI groups. Multivariate logistic regression was used to analyze risk factors including age, gender, body mass index, time from injury to MRI, knee instability, concomitant ligament injury, intra-articular effusion, bone contusion, cartilage injury, meniscal tear location, and meniscal tear pattern.

RESULTS

Enrolled 249 meniscal tears (159 medial and 90 lateral menisci) were sorted into true-positive MRI (n = 136) and false-negative MRI (n = 113) groups. As time from injury to MRI diagnosis increased, the risk of the false-negative MRI diagnosis decreased (adjusted odds ratio [OR], 0.859; 95% confidence interval [CI], 0.802-0.921). Meniscal tear location within the posterior one-third was a significant risk factor compared with tear within the anterior one-third (adjusted OR, 11.823; 95% CI, 2.272-61.519). Peripheral longitudinal tear pattern was also a significant risk factor (adjusted OR, 3.522; 95% CI, 1.256-9.878).

CONCLUSIONS

Significant risk factors for false-negative MRI included short time from injury to MRI diagnosis, meniscal tear location within the posterior one-third, and peripheral longitudinal tear pattern.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Diagnostic Characteristics of Standard Radiographs and Magnetic Resonance Imaging of Ruptures of the Tibialis Posterior Tendon

The present study aimed to diagnose complete rupture (CR) and longitudinal rupture (LR) of the posterior tibial tendon (PTT) from the magnetic resonance imaging findings in patients with PTT dysfunction and to analyze and compare the radiographs from each group to identify radiographic indicators related to the progression of PTT injury that would allow the radiographic diagnosis of CR. We evaluated 32 feet in 27 patients with PTT dysfunction (mean age 66.5, range 49 to 82, years). Radiographs were used to acquire weightbearing anteroposterior images of the foot, which were used to measure the talonavicular coverage angle. Lateral images of the foot were also acquired with the patients in the standing position. These were used to measure the lateral talometatarsal angle, calcaneal pitch angle, and medial cuneiform-fifth metatarsal height. From the axial MRI findings, the patients were divided into a CR group and an LR group, and the radiographic attributes of the CR group were analyzed. Of the 32 feet in 27 patients, 12 feet (37.5%) in 11 patients displayed CR and 20 feet (62.5%) in 18 patients displayed LR. The talonavicular coverage angle was 48.3° ± 17.3° in the CR group and 33.6° ± 13.6° in the LR group (p = .012), and the talometatarsal angle was -28.8° ± 22.5° in the CR group and -25.4° ± 14.4° in the LR group (p = .596). The calcaneal pitch angle was 10.4° ± 6.7° in the CR group and 10.2° ± 8.0° in the LR group (p = .935). Finally, the medial cuneiform-fifth metatarsal height was -4.2 ± 7.1 mm in the CR group and 2.1 ± 4.7 mm in the LR group (p = .005). When a medial cuneiform-fifth metatarsal height of ≤0 mm or talonavicular coverage angle of ≥50° was used as the diagnostic criterion for CR on weightbearing radiographs, the sensitivity was 71.4%, specificity 88.9%, and diagnostic accuracy 81.3%; hence, we believe these to be satisfactory diagnostic criteria for CR.

Diagnostic value of the clinical investigation in acute meniscal tears combined with anterior cruciate ligament injury using arthroscopic findings as golden standard

INTRODUCTION

The main purpose of our study was to evaluate the accuracy of clinical investigation for meniscal tears associated with ACL injuries. We hypothesized that combined ACL injury can decrease the accuracy of clinical examination in acute onset.

MATERIALS AND METHODS

One hundred and thirty-seven patients with a mean age of 28.5 years (from 12 to 55) were prospectively examined for acute combined ACL and meniscal injuries, between March and November 2012 at our department. For meniscal tears, clinical examination was performed using McMurray test, Apley test and medial and lateral joint line tenderness. The diagnoses of ACL tear were made using Lachman test, jerk test and pivot-shift test, anterior drawer test and KT-2000 side-to-side difference. Each patient was examined using X-ray and MRI. All the patients underwent arthroscopic surgery performed by the same surgeon within 6 weeks after the injury. Finally, using the arthroscopic findings as gold standard, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of clinical investigation and MRI were evaluated.

RESULTS

The specificity of clinical investigation was 63.5 and 46.0 % and the sensitivity was 74.4 and 77.3 % for the medial meniscus and the lateral meniscus, respectively. Overall, the accuracy of the clinical investigation was 70.3 % for the MM and 65.5 % for the lateral meniscus. The accuracy of MRI investigation was 76.4 and 69.5 % for medial and lateral meniscus, respectively.

DISCUSSION

In combined acute ACL injury and meniscal tears, we have found a decreased accuracy of the clinical investigation. The remnants of the torn ACL and the synovitis increased the rate of false positives, and it could simulate meniscal tears. However, clinical investigation can provide sufficient information for the treatment decision and MRI can be avoided as a routine diagnostic tool.

LEVEL OF EVIDENCE

Level II, prospective study.

Efficacy of magnetic resonance imaging evaluation for meniscal tear in acute anterior cruciate ligament injuries

PURPOSE

The objective of this study was to compare the preoperative magnetic resonance imaging (MRI) diagnostic rates of meniscal injuries combined with acute anterior cruciate ligament (ACL) injuries, as well as traumatic meniscal injuries without ACL injuries.

METHODS

From January 2005 through April 2013, 208 patients who underwent ACL reconstruction and 1,334 patients with traumatic meniscal tear injuries were examined by MRI and arthroscopy. Patients with chronic ACL injuries, revisions, fracture histories, or multiple-ligament injuries and patients with Outerbridge degenerative changes of grade 3 or greater were excluded, yielding 159 patients and 621 patients in the 2 groups, respectively. The medial meniscus (MM) and lateral meniscus (LM) examined by MRI and arthroscopy for findings of tears were compared in each group. The sensitivity, specificity, positive predictive value, and negative predictive value for MM and LM tears by MRI were compared and analyzed statistically.

RESULTS

The diagnostic sensitivity of MRI in the group with ACL injury was significantly lower than that in the ACL-intact group for the MM (P < .001) and LM (P = .040). The negative predictive value was also lower in the group with ACL injury for both the MM (P = .008) and LM (P < .001). There was no statistical difference in specificity and positive predictive value between the 2 groups.

CONCLUSIONS

This study showed that if a patient had an acute ACL tear, the sensitivity and negative predictive value of MRI for a meniscal tear were less than if there was no ACL tear, which led to the low diagnostic accuracy of MRI.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Ligamentous injuries of the knee: anterior cruciate, medial collateral, posterior cruciate, and posterolateral corner injuries

This article discusses athletic injuries of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and posterolateral corner. Best evidence to date validates that conservative management of ACL ruptures is a reasonable strategy. Current data also seem to advocate nonoperative management of PCL injuries. All isolated MCL injuries, regardless of grade, are usually treated with a brief period of immobilization and symptomatic management. Although the surgical literature often advocates surgical treatment of posterolateral corner injuries, there have been no randomized trials substantiating that these injuries are best treated surgically.

Early magnetic resonance imaging in acute knee injury: a cost analysis

PURPOSE

Acute knee injury is common, and MRI is often only used when non-operative management fails because of limited availability. We investigated whether early MRI in acute knee injury is more clinically and cost-effective compared to conventional physiotherapy and reassessment.

METHODS

All patients with acute indirect soft tissue knee injury referred to fracture clinic were approached. Recruited patients were randomised to either the MRI group: early MRI within 2 weeks or the control group: conventional management with physiotherapy. Patients were assessed in clinic initially, at 2 weeks and 3 months post-injury. Management costs were calculated for all patients until surgical treatment or discharge.

RESULTS

Forty-six patients were recruited: 23 in the MRI and 23 in the control group. Male sex and mean age were similar in the two groups. The total management cost of the MRI group was £16,127 and control group was £16,170, with a similar mean cost per patient (NS). The MRI group had less mean physiotherapy (2.5 ± 1.9 vs. 5.1 ± 3.5, p < 0.01) and outpatient appointments (NS). Median time to surgery and time off work was less in the MRI group (NS). The MRI group had less pain (p < 0.05), less activity limitation (p = 0.04) and better satisfaction (p = 0.04).

CONCLUSIONS

Early MRI in acute knee injury facilitates faster diagnosis and management of internal derangement at a cost comparable to conventional treatment. Moreover, patients had significantly less time off work with improved pain, activity limitation and satisfaction scores.

LEVEL OF EVIDENCE

II.

History, clinical findings, magnetic resonance imaging, and arthroscopic correlation in meniscal lesions

PURPOSE

The aim of this prospective study was to compare the accuracy of clinical examination and magnetic resonance imaging (MRI) versus arthroscopic findings and to determine the value of an experienced examiner in clinical decision making.

METHODS

A total of 30 patients with a preoperative MRI underwent arthroscopy over a 5-month period. All patients had a clinical examination performed by an experienced knee surgeon, a specialist in general orthopedics, a senior resident, and a fourth-year resident. These examiners recorded and evaluated the results of seven tests: the medial and lateral joint line tenderness test, the McMurray test, the Apley test, the Stienmann I test, the Payr's test, Childress' sign, and the Ege's test. The injury was classified as a meniscal tear if there were two positive tests. Clinical history, physical examination, and MRI findings were compared with the arthroscopic findings. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these methods of evaluation were then calculated.

RESULTS

Clinical examination performed by an experienced knee surgeon had better specificity (90% vs. 60%), positive predictive value (95% vs. 83%), negative predictive value (90% vs. 86%), and diagnostic accuracy (93% vs. 83%) than MRI for medial meniscal tears. These parameters showed only a marginal difference in lateral meniscal tears. The experienced knee surgeon had better sensitivity, specificity, predictive values, and diagnostic accuracy parameters for medial meniscus tears in comparison with the other three examiners.

CONCLUSION

These results indicate that clinical examination by an experienced examiner using multiple meniscus tests is sufficient for a diagnosis of a meniscal tear.

LEVEL OF EVIDENCE

II.

The clinical utility and diagnostic performance of magnetic resonance imaging for identification of early and advanced knee osteoarthritis: a systematic review

BACKGROUND

Current diagnostic strategies for detection of structural articular cartilage abnormalities, the earliest structural signs of osteoarthritis, often do not capture the condition until it is too far advanced for the most potential benefit of noninvasive interventions.

PURPOSE

To systematically review the literature relative to the following questions: (1) Is magnetic resonance imaging (MRI) a valid, sensitive, specific, accurate, and reliable instrument to identify knee articular cartilage abnormalities compared with arthroscopy? (2) Is MRI a sensitive tool that can be utilized to identify early cartilage degeneration?

STUDY DESIGN

Systematic review.

METHODS

A systematic search was performed in November 2010 using PubMed MEDLINE (from 1966), CINAHL (from 1982), SPORTDiscus (from 1985), SCOPUS (from 1996), and EMBASE (from 1974) databases.

RESULTS

Fourteen level I and 13 level II studies were identified that met inclusion criteria and provided information related to diagnostic performance of MRI compared with arthroscopic evaluation. The diagnostic performance of MRI demonstrated a large range of sensitivities, specificities, and accuracies. The sensitivity for identifying articular cartilage abnormalities in the knee joint was reported between 26% and 96%. Specificity and accuracy were reported between 50% and 100% and between 49% and 94%, respectively. The sensitivity, specificity, and accuracy for identifying early osteoarthritis were reported between 0% and 86%, 48% and 95%, and 5% and 94%, respectively. As a result of inconsistencies between imaging techniques and methodological shortcomings of many of the studies, a meta-analysis was not performed, and it was difficult to fully synthesize the information to state firm conclusions about the diagnostic performance of MRI.

CONCLUSION

There is evidence in some MRI protocols that MRI is a relatively valid, sensitive, specific, accurate, and reliable clinical tool for identifying articular cartilage degeneration. Because of heterogeneity of MRI sequences, it is not possible to make definitive conclusions regarding its global clinical utility for guiding diagnosis and treatment strategies.

CLINICAL RELEVANCE

Traumatic sports injuries to the knee may be significant precursor events to early onset of posttraumatic osteoarthritis. Magnetic resonance imaging may aid in early identification of structural injuries to articular cartilage as evidenced by articular cartilage degeneration grading.

Approach to knee effusions

The presence of an intra-articular knee effusion requires an extensive differential diagnosis and a systematic diagnostic approach. Pediatric knee effusions occur most commonly as acute hemarthroses after traumatic injury. However, the knee joint is susceptible to effusions secondary to a wide variety of atraumatic causes. Special attention is required in the atraumatic effusion to distinguish features of infectious, postinfectious, rheumatologic, hematologic, vasculitic, and malignant disease. This review discusses the various etiologies of both traumatic and atraumatic pediatric knee effusions highlighting the historical, physical examination, and laboratory characteristics to aid the emergency provider in diagnosis and initial management.

Magnetic resonance imaging in acute traumatic and chronic meniscal tears of the knee: a diagnostic accuracy study in young adults

BACKGROUND

No previous research has investigated the diagnostic validity of magnetic resonance imaging for acute versus chronic meniscal tears using comparable materials and methods.

HYPOTHESIS

There is no difference in the diagnostic validity of magnetic resonance imaging for acute versus chronic meniscal tears in young adults.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

A total of 628 young adult military personnel underwent magnetic resonance imaging and arthroscopy of the knee over a 6-year period. Inclusion criteria were met by 82 patients with acute knee trauma (magnetic resonance imaging within 30 days from trauma) and 40 patients with chronic knee symptoms (symptoms lasting over 6 months before magnetic resonance imaging). The original magnetic resonance imaging and arthroscopy records were reviewed twice by a musculoskeletally trained radiologist, blinded to previous magnetic resonance imaging and arthroscopy findings. Interobserver correlations and intraobserver reliability were calculated and reported. Arthroscopy served as the gold standard when calculating the diagnostic values of magnetic resonance imaging for acute and chronic meniscal tears.

RESULTS

The median age of the patients was 20 years (range, 18-25). Magnetic resonance imaging detected acute meniscal tears with sensitivity of 67%, specificity of 93%, and diagnostic accuracy of 88% and chronic meniscal tears with 64%, 91%, and 86%, respectively. There was no statistically significant difference in magnetic resonance imaging results between the 2 groups.

CONCLUSION

The diagnostic validity of magnetic resonance imaging is similar for meniscal tears in acute knee trauma and in knee symptoms lasting over 6 months in young adults. The results also suggest that effusion or hemarthrosis do not weaken the diagnostic validity of magnetic resonance imaging. The magnetic resonance imaging sensitivity achieved in the present study was relatively poor, but the specificity was good for both acute and chronic meniscal tears. Despite negative magnetic resonance imaging findings at the acute stage of knee trauma, patient monitoring and readiness for arthroscopy should be considered if justified by the patient's symptoms.

The anterior cruciate ligament injury controversy: is "valgus collapse" a sex-specific mechanism?

BACKGROUND

Anterior cruciate ligament (ACL) injury is a devastating injury that puts an athlete at high risk of future osteoarthritis. Identification of risk factors and development of ACL prevention programmes likely decrease injury risk. Although studies indicate that sagittal plane biomechanical factors contribute to ACL loading mechanisms, it is unlikely that non-contact ACL injuries occur solely in a sagittal plane. Some authors attempt to ascribe the solely sagittal plane injury mechanism to both female and male ACL injuries and rebuff the concept that knee "valgus" is associated with isolated ACL injury. Prospective studies that utilise coupled biomechanical and epidemiological approaches demonstrated that frontal knee motions and torques are strong predictors of future non-contact ACL injury risk in female athletes. Video analysis studies also indicate a frontal plane "valgus collapse" mechanism of injury in women. As load sharing between knee ligaments is complex, frontal as well as sagittal and transverse plane loading mechanisms likely contribute to non-contact ACL injury. The purpose of this review is to summarise existing evidence regarding ACL injury mechanisms and to propose that sex-specific mechanisms of ACL injury may occur, with women sustaining injuries by a predominantly "valgus collapse" mechanism.

CONCLUSION

Prevention programmes and interventions that only target high-risk sagittal plane landing mechanics, especially in the female athlete, are likely to be less effective in ameliorating important frontal and transverse plane contributions to ACL injury mechanisms and could seriously hamper ACL injury prevention efforts. Programmes that target the reduction of high-risk valgus and sagittal plane movements will probably prove to be superior for ACL injury prevention.

Sonographic evaluation of the injuries after traumatic patellar dislocation in adolescents

BACKGROUND

Traumatic patellar dislocation (TPD) may be associated with other injuries requiring additional treatment. The superficial localization of the knee extensor apparatus and knee articular cartilage make them accessible to sonographic evaluation (ultrasonography [USG]).

PURPOSE OF THE STUDY

Prospective analysis of the value of USG in TPD.

METHODS

In 21 patients, 22 knees were examined by USG after clinical and routine radiographic evaluations. Based on USG findings, operative or nonoperative treatment was done (15 and 7 cases, respectively).

RESULTS

In 17 knees, lesions of the medial patellofemoral ligament (MPFL) fibers were visible. In 16 knees, avulsion fractures of the patellar insertion of the MPFL were identified. Injuries of the femoral attachment of the MPFL or intramuscular hematoma of the vastus medialis obliquus (VMO) were present in 7 knees. Eleven osteochondral loose bodies and 1 nondisplaced osteochondral fracture were detected in 11 knees. Corresponding osteochondral lesions were localized in all cases. An osteochondral loose body that was identified by USG was confirmed intraoperatively or by computed tomographic scan in 91.6%, the osteochondral lesion localization in 81.8%, and avulsion fracture of the patellar attachment of the MPFL in 100% of knees. Overall, the USG findings were confirmed by these methods in 88.2% of knees.

CONCLUSIONS

Ultrasonography is highly efficient in determining the extent of injuries after TPD in adolescents. Ultrasonography allows visualization of loose bodies, localization of osteochondral lesions, and, using a dynamic modification, allows precise assessment of the functional status of the MPFL.

LEVEL OF EVIDENCE

II.

Clinical, MRI, and arthroscopic correlation in meniscal and anterior cruciate ligament injuries

The aim of this prospective study was to compare and correlate clinical, magnetic resonance imaging (MRI), and arthroscopic findings in cases of meniscal tear and anterior cruciate ligament (ACL) injuries. MRI scan results and clinical diagnosis are compared against the arthroscopic confirmation of the diagnosis. One hundred and thirty-one patients had suspected traumatic meniscal or anterior cruciate ligament (ACL) injury. Clinical examination had better sensitivity (0.86 vs. 0.76), specificity (0.73 vs. 0.52), predictive values, and diagnostic accuracy in comparison to MRI scan in diagnosis for medial meniscal tears. These parameters showed only marginal difference in lateral meniscal and anterior cruciate ligament injuries. We conclude that carefully performed clinical examination can give equal or better diagnosis of meniscal and ACL injuries in comparison to MRI scan. MRI may be used to rule out such injuries rather than to diagnose them.

[Evaluation of cartilage defects in the knee: validity of clinical, magnetic-resonance-imaging and radiological findings compared with arthroscopy]

BACKGROUND

The study was aimed to evaluate the validity of clinical, radiological and MRI examination for cartilage defects of the knee compared with arthroscopic finding.

METHODS

Seven-hundred seventy-two patients who were suffering from knee pain over more than 3 months were evaluated clinical (grinding-sign) and with radiography and magnetic resonance imaging (MRI) and subsequent arthroscopy.

RESULTS

The grinding sign had a sensitivity of 0.39. The association of a positive grinding test with high grade cartilage defects was significant (p<0.000). In 97.4% an intact chondral surface correlated with a normal radiological finding. Subchondral sclerosis, exophytes and a joint space narrowing was significantly associated with high grade cartilage defects (p<0.000). The accuracy of MRI was 59.5%. The MRI resulted in an overestimation in 36.6% and an underestimation in 3.9%. False-positive results were significant more often assessed in low-grade cartilage defects (p<0.000).

CONCLUSIONS

Clinical signs, x-ray imaging and MRI correlate with arthroscopic findings in cases of deep cartilage lesions. In intact or low-grade degenerated cartilage often results an overestimating of these findings.

Traumatic knee extension deficit (the locked knee): can MRI reduce the need for arthroscopy?

In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery. Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one pathological synovial plica). MRI of the knee with acute, traumatic extension deficit is in the acute or subacute phase a safe method to identify the patients that have a mechanical reason for locking and therefore can benefit from arthroscopic treatment.

A ressonância magnética para o diagnóstico das lesões condrais, meniscais e dos ligamentos cruzados do joelho

OBJETIVO: Avaliar o valor diagnóstico da ressonância magnética (RM) do joelho. MATERIAIS E MÉTODOS: Setenta e dois pacientes foram submetidos a RM previamente à artroscopia do joelho realizada por um único cirurgião e considerada como método padrão. Verificou-se a sensibilidade, a especificidade, os valores de verossimilhança e a concordância entre o radiologista e o ortopedista em classificar as lesões. RESULTADOS: O coeficiente de concordância kappa entre a RM e a artroscopia, em classificar as lesões, foi muito bom para lesões de ligamento cruzado anterior (0,84), bom para o menisco lateral (0,75), razoável para o menisco medial (0,50) e baixo para lesões condrais (menor que 0,50). A RM mostrou ter alta sensibilidade para rupturas de ligamento cruzado anterior (94%) e menisco medial (92%), boa sensibilidade para lesões de menisco lateral (80%) e baixa sensibilidade para lesões em todas as zonas condrais (menor que 50%), enquanto a especificidade foi excelente para todas as estruturas condrais, ligamentares e para o menisco lateral estudadas (maior que 97%) e razoável para o menisco medial (65%). CONCLUSÃO: A RM é uma ferramenta útil para subsidiar o diagnóstico clínico de lesões intra-articulares do joelho, como já foi mostrado em resultados semelhantes encontrados na literatura produzida no Brasil e no exterior.

Near-infrared (NIR) spectroscopy. A new method for arthroscopic evaluation of low grade degenerated cartilage lesions. Results of a pilot study

BACKGROUND

Arthroscopy is a highly sensitive method of evaluating high-grade cartilage lesions but the detection of low-grade lesions is often is unreliable. Objective measurements are required. A novel NIRS (near-infrared-spectroscopy) device for detection of low-grade cartilage defects was evaluated in a preliminary clinical study.

METHODS

In 12 patients who had undergone arthroscopy, the cartilage lesions within the medial knee compartment were classified according to the ICRS protocol. With a NIR spectrometer system and an optical probe, similar in design to a hook used for routine arthroscopy, the optical properties of cartilage were measured during arthroscopy.

RESULTS

The mean ratio of 2 NIR absorption bands of intact cartilage 3.8 (range 2.3 to 8.7).was significantly lower than that of cartilage with grade 1 lesions (12.8, range 4.8 to 19.6) and grade 2 lesions (13.4, range 10.4 to 15.4).No differences were observed between grade 1 and grade 2 lesions.

CONCLUSION

NIRS can be used to distinguish between ICRS grade 1 lesions and healthy cartilage during arthroscopic surgeries. The results of this clinical study demonstrate the potential of NIRS to objectify classical arthroscopic grading systems.

Acute rotational trauma to the knee: poor agreement between clinical assessment and magnetic resonance imaging findings

OBJECTIVES

To determine the incidence of anterior cruciate ligament (ACL) injuries in the general population; the pathology associated with a knee sprain verified by magnetic resonance imaging (MRI); and the agreement between clinical findings and MRI.

MATERIAL AND METHODS

Inclusion criterion was an acute rotational trauma to the knee associated with effusion. One hundred and fifty-nine consecutive patients, mean age 27 years and 36% women, were included after clinical assessment at the orthopedic emergency unit. Patients were referred to an MRI examination (1.0 or 1.5 T) performed within a median of 8 days of the initial visit.

RESULTS

The annual incidence of MRI verified ACL injuries was 0.81/1000 inhabitants aged 10-64 years. Fifty-six percent (n=89) of those included had sustained an ACL injury of whom 38% had an associated medial meniscus tear. There was a poor agreement between initial clinical antero-posterior laxity and MRI verified presence of an ACL tear (kappa 0.281). Every second patellar dislocation was diagnosed as a ligament injury.

CONCLUSION

Our findings indicate that the incidence of ACL injuries is higher than previously described. We also show that the first clinical examination after an acute knee trauma has a low diagnostic value. Further assessment with MRI improves the chances of a correct diagnosis of intraarticular pathology and is recommended in the early phase after a rotational knee trauma.

The diagnosis of meniscus tears: the role of MRI and clinical examination

Magnetic resonance imaging (MRI) and clinical examination are tools commonly used in the diagnosis of meniscus tears. It has been suggested routine MRI before therapeutic arthroscopy for clinically diagnosed meniscus tears will reduce the number and cost of unnecessary invasive procedures. We designed a systematic review of prospective cohort studies comparing MRI and clinical examination to arthroscopy to diagnosis meniscus tears. Thirty-two relevant studies were identified by a literature review. Careful evaluation by an experienced examiner identifies patients with surgically treatable meniscus lesions with equal or better reliability than MRI. MRI is superior when indications for arthroscopy are solely diagnostic. However, the methods by which such a clinician arrives at a conclusion have not been identified. To create an evidence-based algorithm for the diagnosis of a meniscus tear future investigations should prospectively assess the value of commonly used aspects of the patient history and meniscus tests. MRI is useful, but should be reserved for situations in which an experienced clinician requires further information before arriving at a diagnosis. Indications for arthroscopy should be therapeutic, not diagnostic in nature.

Magnetic resonance imaging for investigation of the knee joint: A clinical and economic evaluation

Objectives:The aim of the study reported here was to investigate whether the use of magnetic resonance imaging (MRI) impacts on the clinical management of patients presenting with chronic knee problems, reduces costs, and improves patient outcome.

Methods:A single-center randomized controlled trial was conducted. Patients attending with knee problems in whom surgery was being considered were randomized either to investigation using an MRI scan or to investigation using arthroscopy. The study investigated benefits in terms of avoidance of surgery and patient health-related quality of life (using SF-36 and EQ-5D). Costs were assessed from the perspectives of the National Health Service and patients. All analyses were by intention to treat.

Results:The trial recruited 118 patients. No statistically significant differences were found between groups in terms of health outcome. However, the use of MRI was associated with a positive diagnostic/therapeutic impact: a significantly smaller proportion of patients in the MRI group underwent surgery (MRI=0.41, No-MRI=0.71;pvalue=.001). There was a similar mean overall cost for both groups.

Conclusions:The use of MRI in patients with chronic knee problems, in whom surgery was being considered, did not increase costs overall, was not associated with worse outcomes, and avoided surgery in a significant proportion of patients.

MR imaging of the menisci and cruciate ligaments: a systematic review

PURPOSE

To systematically review and synthesize published data on the diagnostic performance of magnetic resonance (MR) imaging of the menisci and cruciate ligaments and to assess the effect of study design characteristics and magnetic field strength on diagnostic performance.

MATERIALS AND METHODS

Articles published between 1991 and 2000 were included if at least 30 patients were studied, arthroscopy was the reference standard, the magnetic field strength was reported, positivity criteria were defined, and the absolute numbers of true-positive, false-negative, true-negative, and false-positive results were available or derivable. Pooled weighted and summary receiver operating characteristic (ROC) analyses were performed for tears of both menisci and both cruciate ligaments separately and for the four lesions combined, by using random effects models. Differences were assessed according to lesion type.

RESULTS

Twenty-nine of 120 retrieved articles were included. Pooled weighted sensitivity was higher for medial meniscal tears than that for lateral meniscal tears. However, pooled weighted specificity for the medial meniscus was lower than that for the lateral meniscus. In summary ROC analyses performed per lesion, various study design characteristics were found to influence diagnostic performance. Higher magnetic field strength significantly improved discriminatory power only for anterior cruciate ligament tears. When all lesions were combined in one overall summary ROC analysis, magnetic field strength was a significant but modest predictor of diagnostic performance.

CONCLUSION

Diagnostic performance of MR imaging of the knee is different according to lesion type and is influenced by various study design characteristics. Higher magnetic field strength modestly improves diagnostic performance, but a significant effect was demonstrated only for anterior cruciate ligament tears.

Dynamic magnetic resonance imaging

Among the devices helping with an accurate diagnosis, neither MRI nor arthroscopy is perfect; both delineate pathology in the knee joint with reasonable sensitivity and specificity. MRI, as a noninvasive and nonionizing modality, has made a significant contribution to the understanding of musculoskeletal disturbances. Static images through the patellofemoral joint in different degrees of flexion reveal only the degree of patellar tilt or subluxation, parameters that can be measured also on the axial view of conventional radiography. The accuracy of patellar position on static axial MRI is limited by the absence of muscle contraction, movement, and loading. Dynamic axial images of patellofemoral articulation can demonstrate the degree of flexion where patellar malalignment is maximal and assess whether or not it reduces. Arthroscopy, aside from its diagnostic values, provides the opportunity for treatment of intra-articular changes contributing to knee joint disturbances, but it is an invasive technique with potential risks of complications. The performed cost-effectiveness analysis of MRI is based mainly on estimation of intra-articular pathology of the acutely-injured knee [49,52,56]. There are scarce data on the cost-effectiveness of MRI of patellofemoral alignment in patellofemoral pain knees. Total examination time for active movement dynamic MRI procedure is approximately 8 to 10 minutes, thus it can be performed during routine MRI examination of the knee. In cases of suspected patellofemoral malalignment with symptoms that mimic other types of internal derangement of the knee joint, dynamic MRI can be a procedure of choice for detection of transient patellar dislocation, whereas a single clinical examination cannot differentiate from other internal knee pathologies. Dynamic MRI, although in an experimental phase, gives us a new perspective for dynamic study of the patellofemoral joint.

Clinical decision making in the acutely injured knee based on repeat clinical examination and MRI

To determine the correlation between Magnetic Resonance Imaging (MRI) and clinical examination of the knee after an acute injury, and to see to what extent MRI affected the planned treatment, we examined 90 consecutive patients in a prospective study, clinically and with an extremity Magnetic Resonance (MR) scanner. The number of meniscal lesions, bone bruises and osteochondral lesions found on MRI was significantly higher than the clinical examinations indicated. Despite this, the treatment was only changed in 6 cases. In no case did MRI prevent a planned arthroscopy. MRI may reveal many clinically silent changes in the knee, also after minor injuries. The significance of these MRI findings must await long-term follow-up.

The use of MRI scan of knee injuries in an emergency department

We present a retrospective study of the number of arthroscopically verified total meniscus and cruciate ligament tears seen in our Emergency department one year before, and one year after introducing magnetic resonance imaging (MRI) as a diagnostic tool. The number of total ruptures of the anterior cruciate ligament increased from 34 (1.7% of total 2003 patients) to 67 (2.9% of total 2277). The number of ruptures of the medial meniscus increased from 42 (2.1%) to 87 (3.8%). The number of ruptures of the lateral meniscus remained unchanged. In the first 12 months after introducing MRI we ordered 513 (23%) scans of the total number of 2277 patients with an acute knee condition. Thirty-nine (8%) of these were described with no pathology, 227 (44%) showed total meniscus or cruciate ligament tears. The remaining 247 (48%) were mainly degenerative or partial injuries. The cost per additional new diagnosis was approximately USD 800. The introduction of MRI has enabled us to identify a larger number of patients with meniscus and cruciate ligament injuries.

Current status of imaging procedures in the diagnosis, prognosis and monitoring of osteoarthritis

X-ray, magnetic resonance imaging (MRI) and arthroscopy are the methods most widely used to assess the status of osteoarthritic joints. How do these methods compare? As diagnostic tools, what is the relative sensitivity of X-ray versus MRI, arthroscopy versus MRI and arthroscopy versus X-ray? Which imaging modalities can be used for predicting progression? Scintigraphy and MRI can assess the degree of cellular activity in the tissues of a joint, which may help in prognosis. Are the methods proven and are they reliable? Recommendations for clinical trials in knee osteoarthritis, state it is essential that reproducible radiographs are obtained for reliable assessment of progression. Two radiographic views of the knee have been proposed; which provides the more reliable assessment, the knee in extension or semi-flexed? Compared with standard radiography, does microfocal radiography make a difference to patient numbers required for drug trials?