Diagnostic performance of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents

Management of osteochondritis dissecans of the knee: current concepts review

Osteochondritis dissecans of the knee is being seen with increased frequency in pediatric and young adult athletes and is thought to be, in part, owing to earlier and increasingly competitive sports participation. Despite much speculation, the cause of both juvenile and adult osteochondritis dissecans remains unclear. Early recognition is essential. Whereas adult osteochondritis dissecans lesions have a greater propensity to instability, juvenile osteochondritis dissecans lesions are typically stable, and those with an intact articular surface have a potential to heal with nonoperative treatment through cessation of repetitive impact loading. The value of adjunctive immobilization, protected weightbearing, and unloader bracing has not been established. Skeletally immature patients with stable lesions that have not healed with nonoperative treatment should have consideration given to arthroscopic drilling to promote healing before the lesion progresses and requires more involved treatment with a less optimistic prognosis. Magnetic resonance imaging may allow early prediction of lesion healing potential. The majority of adult osteochondritis dissecans cases as well as those skeletally immature patients with unstable lesions and secondary loose bodies require fixation and possible bone grafting. Many unstable lesions will heal after stabilization, but long-term prognosis is not clear. Chronic loose fragments can be difficult to fix and have poor healing potential. Results of excision of large lesions from weightbearing zones are poor. Chondral resurfacing techniques have limited long-term data for cases of osteochondritis dissecans in skeletally immature patients.

Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVES

To define the accuracy of clinical tests for assessing anterior cruciate ligament (ACL) ruptures.

BACKGROUND

The cruciate ligaments, and especially the ACL, are among the most commonly injured structures of the knee. Given the increasing injury prevalence, there is undoubtedly a growing need for clinical decision making of health care providers. We reviewed the literature to analyze the diagnostic accuracy of the clinical examination for assessing ACL ruptures.

METHODS AND MEASURES

MEDLINE (1966 to April 2005), EMBASE (1989 to April 2005), and CINAHL (1982 to April 2005) searches were performed. Also reference lists of the included studies were reviewed. Studies selected for data extraction were those that addressed the accuracy of at least 1 physical diagnostic test for ACL rupture and compared the performance of the clinical examination of the knee with a reference standard, such as arthroscopy, arthrotomy, or MRI. Searching was limited to English, German, and Dutch languages.

RESULTS

Twenty-eight studies that assessed the accuracy of clinical tests for diagnosing ACL ruptures met the inclusion criteria. Study results were, however, heterogeneous. The Lachman test is the most valid test to determine ACL tears, showing a pooled sensitivity of 85% (95% confidence interval [CI], 83-87) and a pooled specificity of 94% (95% CI, 92-95). The pivot shift test is very specific, namely 98% (95% CI, 96-99), but has a poor sensitivity of 24% (95% CI, 21-27). The anterior drawer test shows good sensitivity and specificity in chronic conditions, respectively 92% (95% CI, 88-95) and 91% (95% CI, 87-94), but not in acute conditions.

CONCLUSION

In case of suspected ACL injury it is recommended to perform the Lachman test. Because the pivot shift test is very specific both in acute as well as in chronic conditions, it is recommended to perform the pivot shift test as well.

Therapeutische Relevanz der Magnetresonanztomographie bei Gelenkverletzungen im Kindesalter

AIM

In this retrospective study, we assessed whether the use of MRI in children provides additional, therapeutically relevant information to assist in the diagnosis of joint injuries. In addition, we determined whether the usefulness of this approach is dependant on age of the child and localisation of the trauma.

METHOD

MRI of 45 children aged between 3 and 16 years were analysed independently by four different investigators (two radiologists, two trauma surgeons) and assessed for their therapeutic relevance.

RESULT

MRI of the knee (n=18) gave additional information in 11 patients (61%) and led to a change in the recommended therapy involving arthroscopy in seven patients (39%). MRI of the ankle (n=21) provided additional information in 12 patients (57%) and the decision for further therapy was influenced in six patients (29%), however, the indication for surgery was not influenced. The diagnosis of injuries of the elbow (n=6) was changed in four patients (67%), but the therapeutic decision was not influenced.

CONCLUSION

MRI additional to conventional x-ray provides relevant information on the therapeutic procedure to be used for the knee, whereas for the ankle and the elbow MRI it rarely delivers additional information relevant to therapeutic decision making.

Magnetic resonance imaging of the knee in children and adolescents. Its role in clinical decision-making

BACKGROUND

Recent studies have questioned the utility of magnetic resonance imaging in the diagnosis of pediatric knee disorders because of the morphologic changes during growth and the low accuracy of the formal interpretation of the magnetic resonance imaging scan by a radiologist. The purpose of this study was twofold: (1) to report the accuracy of formal interpretations of magnetic resonance imaging scans of the knee in children and adolescent patients by a radiologist, and (2) to determine the benefit, if any, of a personal review of the magnetic resonance imaging scan of the knee by the orthopaedic surgeon, as a routine part of the diagnostic evaluation.

METHODS

A three-year prospective study of all patients who underwent knee arthroscopy performed by a single surgeon, at two children's hospitals, was completed. The analysis focused on the six most common diagnoses: anterior cruciate ligament tear, lateral meniscal tear, medial meniscal tear, osteochondritis dissecans, discoid lateral meniscus, and osteochondral fracture. The preoperative diagnosis of the surgeon was determined by integrating the history and the findings on the clinical examination, plain radiographs, and magnetic resonance imaging scans (including the radiologist's interpretation).

RESULTS

Ninety-six patients with ninety-six abnormal knees were included. The mean age was 14.6 years at the time of surgery. Relative to operative findings, kappa values for the formal interpretations of the magnetic resonance imaging scans by a radiologist were 0.78 for an anterior cruciate ligament tear, 0.76 for a medial meniscal tear, 0.71 for a lateral meniscal tear, 0.70 for osteochondritis dissecans, 0.46 for discoid lateral meniscus, and 0.65 for osteochondral fracture. Relative to operative findings, kappa values for the preoperative diagnoses by the surgeon were 1.00 for an anterior cruciate ligament tear, 0.90 for a medial meniscal tear, 0.92 for a lateral meniscal tear, 0.93 for osteochondritis dissecans, 1.00 for discoid lateral meniscus, and 0.90 for osteochondral fracture. The preoperative diagnosis by the surgeon was better (p < 0.05) than the formal interpretation of the magnetic resonance imaging scans by the radiologist with respect to an anterior cruciate ligament tear, lateral meniscal tear, osteochondritis dissecans, and discoid lateral meniscus.

CONCLUSIONS

Integration of patient information with an orthopaedic surgeon's review of the magnetic resonance imaging scan of the knee in children and adolescent patients improves the identification of pathological disorders in four of the six categories evaluated. This study questions the necessity for and appropriateness of a routine interpretation of a magnetic resonance imaging scan of the knee in children and adolescents by a radiologist.

Anterior and posterior cruciate ligament injuries

Knee pain is a common complaint in the primary care setting, and ACL and PCL injuries are common causes of knee pain. Therefore, it is important for the primary care physician to be skilled in the diagnosis and initial management of these injuries and to be aware of potential associated knee injuries. By understanding the history, mechanism of injury, physical examination maneuvers, and imaging modalities related to ACL and PCL injuries, primary care physicians can prepare themselves to make an accurate diagnosis. Then they can counsel the patients on the available treatments, initiate conservative treatment if appropriate, and facilitate an effective referral to a primary care sports medicine physician or orthopedic surgeon.

Physical examination of the knee

Regardless of whether knee pain is acute or chronic in presentation, the primary care physician must be confident and practiced in his or her musculoskeletal examination skills to perform a thorough assessment. Keeping in mind the types of problems that tend to occur in different age groups and in certain patient populations with particular risk factors, a preconceived differential diagnosis list should be present in the physician's mind. In most cases, the history and physical examination findings are sufficient to formulate a definitive diagnosis. Plain radiography (multiple views) and laboratory studies if indicated may narrow the differential. Advanced imaging studies will affirm the clinical findings. Referral may be necessary for surgical management, particularly in pediatric and unstable orthopedic cases (eg, suspected growth plate injury, compartment syndromes, displaced or intra-articular fractures). Consultation should always be readily available if questions arise on preliminary clinical work-up and management.

A locked knee in an adolescent boy: resolving meniscal pathology in young athletes

A young athlete presenting with a locked knee is an uncommon occurrence in most outpatient clinics. Locked knees in children are primarily caused by meniscal tears, a discoid meniscus, or osteochondritis dissecans. When diagnosing meniscal tears, the history, physical examination, MRI, and/or arthroscopy are used to support a definitive diagnosis. Arthroscopic surgery is performed with the intention to preserve as much of the nontraumatized meniscus as possible, as in this case of an adolescent whose knee required surgical repair. However, in some cases, a total menisectomy is inevitable.

[Osteochondritis dissecans of the knee joint]

BACKGROUND

Osteochondritis dissecans (OD) is an affection of the subchondral bone involving progressive detachment of an osteochondral fragment.

METHODS

This article describes the epidemiology, etiology, clinical appearance, possibilities for radiological diagnostics, and classification of OD and presents conservative and surgical therapeutic techniques.

RESULTS

Treatment of OD depends on the size, location, stability of the fragment, and skeletal maturity. The majority of young patients can be treated conservatively. Surgical interventions include antegrade or retrograde drilling with optional refixation and osteochondral transplantation as well as autologous chondrocyte transplantation.

CONCLUSION

The results of surgical intervention are quite promising; nevertheless, further prospective comparative studies are necessary to evaluate effectivity.

Acute Injury of the Articular Cartilage and Subchondral Bone:A Common but Unrecognized Lesion in the Immature Knee

OBJECTIVE

We studied the prevalence of injuries of the articular cartilage and subchondral bone after acute trauma in skeletally immature knees using high-resolution MRI.

MATERIALS AND METHODS

We reviewed knee MRIs of 126 young children and adolescents suspected to have internal knee derangement, including 82 with open physes and a control group of 44 who were skeletally mature. High-resolution proton density and T2-weighted pulse sequences were used in all patients. The prevalence of common injuries in the two groups was compared using chi-square analysis. Levels of interobserver agreement for evaluation of chondral lesions in the skeletally immature group were determined using the kappa statistic.

RESULTS

In the skeletally immature group, chondral lesions were the most prevalent injuries (prevalence = 0.34, p = 0.009) followed by meniscal and anterior cruciate ligament injuries (prevalence = 0.23 and 0.24, respectively). No significant difference in the prevalence of chondral injury before and after physeal closure was seen (p = 0.45). There was no significant difference in the prevalence of anterior cruciate ligament injuries between the two groups, but meniscal injuries were more prevalent in the skeletally mature patients (prevalence = 0.41, p = 0.037). Interobserver agreement for chondral injuries in the group with open physes was good (weighted kappa = 0.45-0.51).

CONCLUSION

The most common injuries occurring as a result of acute trauma to the immature knee were chondral. In patients with open physes, chondral injuries were significantly more prevalent than anterior cruciate ligament and meniscal injuries.

Tumors about the knee misdiagnosed as athletic injuries

BACKGROUND

Musculoskeletal tumors may originally mimic a traumatic condition, and, on the basis of an erroneous diagnosis of an athletic injury, an invasive diagnostic or therapeutic procedure may be performed. We determined the number of such cases treated at our institution, and we analyzed the initial and final diagnoses as well as the changes in the indicated oncologic surgical technique due to the initial erroneous diagnosis.

METHODS

Twenty-five patients who had a bone or soft-tissue tumor about the knee that originally had been diagnosed as an athletic injury were referred to our institution. The complete clinical, radiographic, and pathological records were reviewed. Studies that had been performed prior to the invasive procedure and at the time of admission to our institution were evaluated to determine differences in the tumor stage and the oncologic treatment that was indicated at each time.

RESULTS

Of 667 knee tumors diagnosed in our institution, twenty-five (3.7%) previously had been treated with an intra-articular procedure as a result of a misdiagnosis of an athletic injury. The final diagnoses made at our institution were a benign tumor in eleven patients and a malignant tumor in fourteen. Oncologic surgical treatment was affected in fifteen of the twenty-five patients.

CONCLUSIONS

When a knee tumor is initially misdiagnosed as an athletic injury, treatment may be adversely affected by the delay in diagnosis or an inappropriate invasive procedure that results in extension of the tumor. Initial poor-quality radiographs and an unquestioned original diagnosis despite persistent symptoms were the most frequent causes of an erroneous diagnosis.

Meniscal disorders: normal, discoid, and cysts

Meniscal injuries in children and adolescents are being seen with increased frequency. Meniscal tears are typically traumatic injuries in adolescents. Because of increased healing potential and the younger age of these patients, attempts at meniscal preservation should be emphasized for outer and middle third tears. Discoid meniscus typically presents as a snapping knee in younger children or as a meniscal tear in older children. Again, meniscal preservation by saucerization is emphasized. Careful attention should be given to the need for additional meniscal repair. Popliteal cysts typically present as a painless mass. Because they are usually not associated with an internal pathology and often resolve spontaneously, the preferred treatment is observation.

Discoid lateral meniscus: diagnosis and results of arthroscopic treatment

We evaluated the results of arthroscopic meniscectomy in patients with discoid lateral menisci of the knee. Discoid lateral menisci were detected in 308 patients, of whom 197 (124 males, 73 females; mean age 34.5 years, range 6-67) were clinically, radiologically, and arthroscopically found to be symptomatic and underwent partial meniscectomy. The average period between injury and operation was 13.2 months (range 6-52). The results were evaluated according to the Ikeuchi and Lysholm criteria. The mean follow-up was 57.8 months (range 24-138). The most common complaints were pain (66%) and joint line tenderness (61%). Widening of lateral joint space was the most common radiological finding (25%). The confirmation of diagnosis by magnetic resonance imaging was not congruent with arthroscopic results for some patients (31%). According to the Ikeuchi criteria, the results were excellent in 110 patients (56%), good in 53 (27%), fair in 26 (13%), and poor in 8 (4%). On the other hand, according to the Lysholm scale, the results were excellent in 119 patients (60%), good in 57 patients (29%), fair in 16 (8%), and poor in five (3%) patients. Clinical and radiological findings were not congruent with arthroscopic results for all patients. Therefore arthroscopic evaluation has more value for discoid lateral meniscus. Moreover, tear pattern and degenerative changes in lateral compartment may effect outcomes without relation to the type of surgery. We concluded that arthroscopic partial meniscectomy should be the preferred method for the surgical treatment for discoid lateral menisci, due to it's minimal traumatic effects, possibilities of early mobilization, a lower complication rate, and easy and short rehabilitation period.

Anterior cruciate ligament injury in children: update of current treatment options

As our society's interest in competitive athletics has grown, so has the participation of our youth. Unfortunately, along with this increase in participation has come a predictable increase in rate of injury. More specifically, anterior cruciate ligament injury in the skeletally immature individual is being recognized with increasing frequency and currently poses an unsolved clinical problem. Conservative management of midsubstance anterior cruciate ligament tears in the skeletally immature population has been shown to have an unfavorable prognosis related to functional knee instability, subsequent meniscal tears, and the development of early degenerative arthritis. Despite poor outcomes following conservative treatment, many orthopaedic surgeons have been reluctant to perform anterior cruciate ligament reconstructions in skeletally immature patients due to the potential for physeal injury and resultant growth disturbance. Although there is growing evidence in the literature suggesting that anterior cruciate ligament reconstruction in the adolescent population may be safely performed using anatomic, transphyseal techniques, there are insufficient data to provide concrete guidelines in treatment of anterior cruciate ligament injuries in the prepubescent population. Management of these injuries, therefore, must be based on the physiologic and skeletal maturity of the child. Anterior cruciate ligament reconstruction in the skeletally immature individual still poses a clinical problem with the safest and most effective techniques still evolving.

Osteochondritis dissecans of the knee in children

Osteochondritis dissecans is a term used to describe the separation of an articular cartilage subchondral bone segment from the remaining articular surface. Juvenile osteochondritis dissecans describes an osteochondritis dissecans lesion found in skeletally immature children with a maximum incidence occurring between the ages of 10 and 20. It is found more frequently in children who are active athletically and involved in organized sports and is twice as common in males as in females. Although the etiology of these lesions is unclear, it is believed that repetitive microtrauma may interrupt the already tenuous epiphyseal blood supply in the growing child and contribute to the development of osteochondritis dissecans lesions. Treatment is dependent upon age at presentation, fragment size, fragment location, and fragment stability. Stable lesions in skeletally immature patients are generally amenable to conservative management. Failed conservative management or unstable lesions will more likely require surgical intervention. Lesions in skeletally mature patients have a more unpredictable course and may require surgery. This review article discusses the anatomy, etiology, evaluation, classification, treatment, and expected outcome of osteochondritis dissecans lesions.

Partial tears of the anterior cruciate ligament in children and adolescents

BACKGROUND

The functional outcome after partial anterior cruciate ligament tears in children and adolescents treated without reconstruction has not been established.

HYPOTHESIS

Nonreconstructive management of partial anterior cruciate ligament tears can be effective in certain pediatric patients.

STUDY DESIGN

Prospective cohort study.

METHODS

We studied 45 skeletally mature and immature patients 17 years of age or less who had an acute hemarthrosis, magnetic resonance imaging signal changes, grade A or B Lachman and pivot shift result, and an arthroscopically documented partial anterior cruciate ligament tears. All patients were treated without reconstruction, underwent a structured rehabilitation program, and were followed up for a minimum of 2 years.

RESULTS

Fourteen patients (31%) underwent subsequent reconstruction. Significant associations with subsequent reconstruction included tears that were greater than 50%, predominantly posterolateral tears, a grade B pivot shift test result, and older chronologic and skeletal age. Among patients who did not require reconstruction, those with tears that were greater than 50% or predominantly posterolateral had significantly lower Lysholm, satisfaction, and Cincinnati Knee Scale scores.

CONCLUSIONS

Nonreconstructive management is recommended for partial anterior cruciate ligament tears in children and adolescents 14 years of skeletal age or younger with normal or near-normal Lachman and pivot shift results. Reconstruction is recommended in older athletes or in those with greater than 50% or predominantly posterolateral tears.

Magnetic resonance imaging of the pediatric knee

Magnetic resonance imaging (MRI) is an excellent modality for imaging the pediatric knee because of its superb soft-tissue contrast, multiplanar capability, and lack of ionizing radiation. The knee is the most common joint imaged by MRI in the pediatric population. The majority of studies are performed on older children or adolescents with pain and/or known trauma. There are variations of injury and patterns of injury that are unique to children. The knee of a child also may be studied by MRI for other indications, including tumor, inflammatory disease, and developmental abnormalities. It is important to have a systematic approach to analysis of the knee MR images. Analysis should include individual attention to bones, articular cartilage, muscles and tendons, soft tissues, neurovascular bundle, joint space, fluid collections, ligaments, and menisci.