Correlation of arthroscopic and clinical examinations with magnetic resonance imaging findings of injured knees in children and adolescents

Feasibility and efficacy of ultrasound in the diagnosis of discoid lateral meniscus and its classification in children: protocol for a prospective, multicentre, diagnostic test study

INTRODUCTION

Although ultrasound can reportedly diagnose discoid lateral meniscus (DLM) in children, its widespread application is challenging because the diagnostic criteria are based on qualitative descriptions of DLM morphology rather than quantitative parameters. Additionally, no studies have applied ultrasound in classifying DLM. Therefore, this study aims to establish the quantitative ultrasound parameters that reflect DLM morphology, evaluate the feasibility and validity of these parameters for identifying DLM and their classification, and develop the quantitative ultrasound diagnostic criteria for DLM and their classification in children.

METHODS AND ANALYSIS

Patients will be recruited from the outpatient clinics of the orthopaedics department at West China Hospital, Sichuan University, the Fourth Medical Center of the Chinese People's Liberation Army General Hospital, Xinhua Hospital affiliated with Shanghai Jiao Tong University School of Medicine, Yibin Hospital affiliated with West China Hospital Sichuan University, Suining Central Hospital and the Third Hospital of Mianyang from August 2022 to July 2024. Eligible patients are those aged ≤14 years, with knee symptoms such as pain, locking and limited extension, and who planned to undergo arthroscopic surgery. Exclusion criteria are patients with contraindications to ultrasound examination, such as severe skin damage or fracture around the knee. The sample size is estimated to be 576 cases with a power of 0.9 for hypothesis testing, a two-sided α of 0.05, and an expected sensitivity and specificity of 95%. Three days before surgery, ultrasound will be used to observe the morphology of the lateral meniscus and measure its width, angle α formed by the chord of upper and lower arc-shaped articular surface at the free edge, and the movement distance of the peripheral rim. Participants will be categorised according to the arthroscopy results for the DLM and its classification. The diagnostic performance of each parameter will be assessed and compared in terms of the area under the curve, sensitivity, specificity, and positive and negative predictive values.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of West China Hospital, Sichuan University (approval no. 2022-923), and this approval covers all study hospitals. Written informed consent is required from all participants before enrolment in the study. The study's findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2200062000).

Validity of the McMurray Test for Meniscal Tear in Pediatric and Adolescent Patients

OBJECTIVE

The aim of this study was to identify the accuracy of the McMurray test in the adolescent and pediatric population.

DESIGN

Retrospective case series.

SETTING

Tertiary care, institutional.

PATIENTS

Inclusion criteria included patients who presented with unilateral knee pain and were seen by pediatric sports medicine physicians. Patients were excluded if their knee pain was related to any underlying conditions. Three hundred patient charts were reviewed, and 183 patients (age range: 8-18 years, mean: 14 years; 74 male) met the inclusion criteria.

INTERVENTIONS

Symptoms at initial visit (knee pain).

MAIN OUTCOME MEASURES

Presence of a meniscal tear using the McMurray test.

RESULTS

Eighty-four percent (160/191) of patients had a McMurray test documented as performed by the physician, and 17% (27/160) elucidated a positive response. Of 26 patients who had a positive McMurray and underwent magnetic resonance imaging (MRI), 16 (62%) showed a meniscal tear on their MRI. However, of the 87 patients who had a negative McMurray and still underwent MRI, 25 (29%) had a positive meniscal tear. The sensitivity, specificity, positive predictive value, and negative predictive value were 39%, 86%, 62%, and 71%, respectively.

CONCLUSION

In a pediatric and adolescent population, the McMurray test was negative for 61% (23/38) of meniscal tears identified on MRI.

CLINICAL RELEVANCE

Although the test can be a useful tool as a part of a thorough evaluation, combining it with mechanical symptoms, patient history and imaging may be more helpful to diagnose a meniscus tear.

Diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect anterior cruciate ligament injuries in children and adolescents: a prospective diagnostic study

Background

Diagnosing anterior cruciate ligament (ACL) injuries in children and adolescents are more challenging compared to adults. Delayed diagnosis may result in meniscal or chondral injuries. The aim of this study was to determine the diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect ACL injuries in children and adolescents.

Methods

In this prospective diagnostic study, all children and adolescents (< 18 years) with post-traumatic knee complaints presenting at the out-patient department of the Máxima MC were eligible for inclusion. One experienced knee specialised orthopaedic surgeon was blinded and performed history taking, physical examination and KT-1000 arthrometer measurement. All patients had a magnetic resonance imaging (MRI) for the final diagnosis. Diagnostic values of interest were sensitivity, specificity, positive and negative predictive values (PPV and NPV). The outcomes of the KT-1000 arthrometer were drafted in a relative operating characteristics (ROC) curve to determine the optimal cut-off points.

Results

Sixty-six patients were included, of which 50 had an ACL rupture and 16 had no ACL rupture on MRI. Report of a popping sensation during trauma had a specificity and PPV of 100% for diagnosing ACL injuries. The PPV and NPV of the Lachman test (in case of describing end-feel) were 95 and 82%, of the anterior drawer test 87 and 90% and of the pivot shift test 95 and 81% respectively. The optimal cut-off point of the KT-1000 arthrometer at 133 N force was an absolute translation of ≥7 mm with a PPV and NPV of 97 and 88% respectively.

Conclusions

Report of a popping sensation during trauma has a specificity and PPV of 100% for diagnosing ACL injuries in children and adolescents. Although potentially difficult in children, the Lachman test, anterior drawer test and pivot shift test have a high PPV and NPV when performed by an experienced orthopaedic surgeon. An absolute anterior translation of ≥7 mm of the injured knee in the KT-1000 arthrometer at 133 N has the highest diagnostic values of all tests for diagnosing ACL injuries.

Level of evidence

3

Diagnostic Performance of MRI Versus CT in the Evaluation of Intra-articular Osteochondral Fracture in Pediatric Patients With Acute Traumatic Lateral Patellar Dislocation

Background:

Evaluation of intra-articular osteochondral fractures in children with acute traumatic lateral patellar dislocation (LPD) is important for determining treatment options.

Purpose:

To (1) compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for evaluating intra-articular osteochondral fractures; (2) compare the interpretation of CT and MRI images between radiologists and pediatric orthopaedic surgeons (POS); and (3) investigate any clinical factors influencing the accuracy of CT and MRI evaluations.

Study Design:

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

Methods:

We reviewed 35 knees in 35 patients (mean age, 12.2 ± 1.2 years; 12 boys and 23 girls) who were treated arthroscopically for acute traumatic LPD; 71% of the patients had patellar fractures, 54% had femoral fractures, and 60% had free osteochondral fracture fragments. All presurgical MRI and CT images were reviewed by POS who were blinded to both the reports of the radiologists and surgical records. We compared the accuracy of CT and MRI in diagnosing intra-articular osteochondral fractures against the arthroscopic findings and compared the interpretation of the images by the POS (MRI-O, CT-O) with those of the radiologists (MRI-R, CT-R).

Results:

There was no significant difference in diagnostic accuracy between CT and MRI for overall intra-articular osteochondral fractures by the POS or the radiologists; however, the CT-O images had a higher diagnostic specificity (84.2% vs 69.6%; P < .001) and sensitivity (88.1% vs 70.1%; P < .001) versus the MRI-R images. Regarding free fracture fragments, the CT-R images had a higher diagnostic accuracy than the MRI-R images (73.5% vs 47.1%; P = .026). When backed by clinical data, the MRI-O images had greater diagnostic accuracy (78.7% vs 60.3%; P = .001) and sensitivity (88.1% vs 30.7%; P = .021) but lower specificity compared with the MRI-R images, and the CT-O images had similar diagnostic accuracy but greater sensitivity than the CT-R images (70.1% vs 52.2%; P < .001). The diagnostic accuracy of MRI-O images was lower for children under 12 years versus children 12 years and over (67.5% vs 83.3%; P = .040).

Conclusion:

Compared with MRI, CT scans had better diagnostic performance in the evaluation of intra-articular osteochondral fractures in pediatric patients with acute traumatic LPD. Clinical data enhanced the diagnostic sensitivity of MRI and CT but decreased the specificity of MRI. MRI evaluations remain challenging for both POS and radiologists.

Isolated meniscus injuries in skeletally immature children and adolescents: state of the art

The prevalence of isolated meniscal injuries in children and adolescents is low; however, we see an increase mainly due to intensified sports-related activities at an early age. A meniscal repair should be attempted whenever possible as children present with increased meniscal healing potential. The diagnosis and management of meniscal tears involve both patient factors and tear characteristics: size, anatomical location and associated injuries. Special attention should be given to the feature of discoid menisci and related tears as they require a specific management plan. This state-of-the-art review highlights the most recent studies on clinical evaluation, surgical techniques, tips and tricks, pitfalls, outcomes, return-to-sports, geographical differences and future perspectives related to meniscal injuries in children and adolescents.

Tibial Spine Fractures: How Much Are We Missing Without Pretreatment Advanced Imaging? A Multicenter Study

BACKGROUND

There is a high rate of concomitant injuries reported in pediatric patients with tibial spine fractures, ranging from 40% to 68.8%. Many tibial spine fractures are treated without initial magnetic resonance imaging (MRI).

PURPOSE

To understand rates of concomitant injury and if the reported rates of these injuries differed among patients with and without pretreatment MRI.

STUDY DESIGN

Cross-sectional study; level of evidence, 3.

METHODS

We performed an institutional review board-approved multicenter retrospective cohort study of patients treated for tibial spine fractures between January 1, 2000, and January 31, 2019, at 10 institutions. Patients younger than 25 years of age with tibial spine fractures were included. Data were collected on patient characteristics, injury, orthopaedic history, pretreatment physical examination and imaging, and operative findings. We excluded patients with multiple trauma and individuals with additional lower extremity fractures. Patients were categorized into 2 groups: those with and those without pretreatment MRI. The incidence of reported concomitant injuries was then compared between groups.

RESULTS

There were 395 patients with a tibial spine fracture who met inclusion criteria, 139 (35%) of whom were reported to have a clinically significant concomitant injury. Characteristics and fracture patterns were similar between groups. Of patients with pretreatment MRI, 79 of 176 (45%) had an identified concomitant injury, whereas only 60 of 219 patients (27%) without pretreatment MRI had a reported concomitant injury (P < .001). There was a higher rate of lateral meniscal tears (P < .001) in patients with pretreatment MRI than in those without. However, there was a higher rate of soft tissue entrapment at the fracture bed (P = .030) in patients without pretreatment MRI. Overall, 121 patients (87%) with a concomitant injury required at least 1 treatment.

CONCLUSION

Patients with pretreatment MRI had a statistically significantly higher rate of concomitant injury identified. Pretreatment MRI should be considered in the evaluation of tibial spine fractures to improve the identification of concomitant injuries, especially in patients who may otherwise be treated nonoperatively or with closed reduction. Further studies are necessary to refine the indications for MRI in patients with tibial spine fractures, determine the characteristics of patients at highest risk of having a concomitant injury, define the sensitivity and specificity of MRI in tibial spine fractures, and investigate patient outcomes based on pretreatment MRI status.

Discoid lateral meniscus: importance, diagnosis, and treatment

Discoid lateral meniscus (DLM) is a common anatomic variant in the knee typically presented in young populations, with a greater incidence in the Asian population than in other populations. As DLM is a congenital anomaly, the ultrastructural features and morphology differ from those of the normal meniscus, potentially leading to meniscal tears. Snapping and pain are common symptoms, with occasional limitations of extension, in patients with DLM. Examination of the contralateral knee is necessary as DLM affects both knees. While simple radiographs may provide indirect signs of a DLM, magnetic resonance imaging (MRI) is essential for diagnosis and treatment planning. Although DLM was traditionally classified into three categories, namely, complete, incomplete, and Wrisberg DLM, a recent MRI classification provides useful information for surgical planning because the MRI classification was based on the peripheral detachment in patients with DLM, as follows: no shift, anterocentral shift, posterocentral shift, and central shift. Asymptomatic patients require close follow-up without surgical treatment, while patients with symptoms often require surgery. Total or subtotal meniscectomy, which has been traditionally performed, leads to an increased risk of degenerative arthritis; thus, partial meniscectomy is currently considered the treatment of choice for DLM. In addition to partial meniscectomy, meniscal repair of peripheral detachment is recommended for stabilization in patients with DLM to preserve the function of the meniscus. Previous studies have reported that partial meniscectomy with or without meniscal repair is effective and shows superior clinical and radiological outcomes to those of total or subtotal meniscectomy during the short- to long-term follow-up. Our preferred principle for DLM treatment is reduction, followed by reshaping with reference to the midbody of the medial meniscus and repair as firm as possible.

Kinematic features in patients with lateral discoid meniscus injury during walking

At present, there few studies on the kinematic features of lateral discoid meniscus injury. In this study, a motion capture system was used to investigate the motion characteristics of knees with lateral discoid meniscus after injury, and the differences between the knees with lateral meniscus and intact knees were compared. Fourteen patients diagnosed with unilateral lateral discoid meniscus injury, fourteen patients diagnosed with unilateral lateral meniscus injury, and fourteen normal subjects with healthy knees were recruited and grouped. Through kinematic gait analysis, it was found that the subjects in the two groups with meniscus injuries exhibited significantly smaller ranges of rotation and translation than those with healthy knees on the sagittal, coronal, and horizontal planes, but not in proximal-distal translation. Maximum lateral tibial translation and maximum internal tibial rotation in the knees with lateral discoid meniscus injury were significantly decreased compared to those with lateral meniscus injury. The results show that the kinematic features of knees with lateral discoid meniscus injury are statistically different than those of healthy knees and knees with lateral meniscus injury. This study provides an important reference for the dynamic function of knees with lateral discoid meniscus injury.

Diagnosis and Treatment of Discoid Meniscus

There is a greater incidence of discoid meniscus in Asian countries than in Western countries, and bilateral discoid menisci are also common. The discoid meniscus may be a congenital anomaly, and genetics or family history may play a role in the development of discoid menisci. Because the histology of discoid meniscus is different from that of normal meniscus, it is prone to tearing. Individuals with a discoid meniscus can be asymptomatic or symptomatic. Asymptomatic discoid menisci do not require treatment. However, operative treatment is necessary if there are symptoms. Total meniscectomy leads to an increased risk of osteoarthritis. Therefore, total meniscectomy is generally reserved for rare unsalvageable cases. Partial meniscectomy (saucerization) with preservation of a stable peripheral rim combined with or without peripheral repair is effective, and good short-, mid-, and long-term clinical results have been reported.

Is posterior tibial slope associated with noncontact anterior cruciate ligament injury?

PURPOSE

This study aimed to: (1) examine whether the association between posterior tibial slope and noncontact ACL injury exists in Chinese population; (2) compare the reliability and consistency of the three methods (longitudinal axis, posterior and anterior tibial cortex axis) in lateral radiograph.

METHODS

Case-control study contained 146 patients in total (73 noncontact ACL injuries and 73 meniscus injuries, matched for age and gender), which were verified by arthroscopy, MRI and physical examination.

RESULTS

For the total population and the male subgroup, the mean posterior tibial slope of the ACL-injured group was significantly higher than that of the control group (P < 0.001). In addition, the longitudinal axis method exhibited the highest inter-rater (0.898) and intrarater reliability (0.928), whereas the anterior tibial cortex was the most variable (inter-rater reliability, 0.805; intrarater reliability, 0.824). The anterior tibial cortex method produced largest posterior tibial slope measurements (13.8 ± 3.3 for injury group; 11.6 ± 2.7 for control group), while the posterior tibial cortex method was the smallest (9.1 ± 3.1 for injury group; 7.2 ± 2.6 for control group). All three methods were not affected by age, sex, height, weight and BMI (n.s.).

CONCLUSIONS

The results of this study suggested that an increased posterior tibial slope was associated with the risk of noncontact ACL injury in Chinese population. Meanwhile, the longitudinal axis method is recommended for measuring posterior tibial slope in lateral radiograph in future studies. Posterior tibial slope measured by longitudinal axis method may be used as predictor of ACL injury.

LEVEL OF EVIDENCE

Case-control study, Level III.

Risk factors for noncontact anterior cruciate ligament injury: Analysis of parameters in proximal tibia using anteroposterior radiography

Objective

To investigate the relationship between the proximal tibial parameters of tibia width (TW), eminence width (EW), and eminence width index (EWI), and noncontact anterior cruciate ligament (ACL) injury, in a Chinese population.

Methods

A retrospective case–control study was conducted of all ACL reconstructions (ACL group) and meniscal surgeries (control group) undertaken at two Chinese hospitals. Patients in the ACL group were age- and sex-matched with controls. Anteroposterior knee radiographs were used to measure the TW, EW and EWI.

Results

A total of 73 pairs of patients who were verified by knee arthroscopy, magnetic resonance imaging and physical examination were included in the study. There was no significant difference between the ACL group and the control group in terms of TW in the total population and in the two sex subgroups. The ACL group had a significantly smaller EW and EWI compared with the control group in the total population and in the two sex subgroups.

Conclusion

Decreased EW and EWI are associated with increased risk of noncontact ACL injury in a Chinese population.

The Clinical Effectiveness of the Extended-Scope Physiotherapist Role in Musculoskeletal Triage: A Systematic Review

BACKGROUND

Extended-scope physiotherapists (ESPs) are working in musculoskeletal (MSK) triage clinics to assess, diagnose and refer patients for appropriate management. However, there is inadequate appraisal of their clinical effectiveness.

OBJECTIVES

The aim of the present systematic review was to appraise the evidence on the diagnostic ability of ESPs in MSK triage, and patient and general practitioner (GP) satisfaction when seen by an ESP in a MSK clinic.

METHOD

CINAHL, AMED, MEDLINE and EMBASE databases were searched from 1989 to February 2014 using the keywords 'physiotherapy', 'extended practitioner' and 'musculoskeletal disease'. Data extraction was compiled using the Centre for Reviews and Dissemination (2009) method. Diagnostic accuracy studies were assessed for methodological quality using the Scottish Intercollegiate Guideline Network (SIGN). Patient/GP satisfaction was assessed using a tool adapted by Desmeules et al. (2012).

RESULTS

From 146 studies initially identified, 14 were eligible for review. Only one diagnostic study was of high quality, and satisfaction study scores ranged from 40% to 73%. All studies reported favourable outcomes for ESPs in MSK triage clinics, with ESPs demonstrating a good level of diagnostic ability in comparison with a gold standard such as surgery. In addition, patients and GPs were satisfied with the overall performance and service provided by ESPs.

CONCLUSION

The evidence suggests that ESPs are clinically effective. However, there were methodological shortcomings in the reviewed studies, and further research, using larger sample sizes, multiple locations and comparisons of the same patient cohorts, would strengthen the evidence available to influence future commissioning of these services. Copyright © 2015 John Wiley & Sons, Ltd.

Diagnostic performance of magnetic resonance imaging and pre-surgical evaluation in the assessment of traumatic intra-articular knee disorders in children and adolescents: what conditions still pose diagnostic challenges?

BACKGROUND

Diagnosis of intra-articular lesions in children based on clinical examination and MRI is particularly challenging.

OBJECTIVE

To evaluate the diagnostic performance of MRI and pre-surgical evaluation of the knee in pediatric patients relative to arthroscopic evaluation as the gold standard. We report diagnoses frequently missed or inaccurately diagnosed pre-operatively.

MATERIALS AND METHODS

We conducted a retrospective review of MRI and pre-surgical evaluation in children and adolescents ages 1-17 years who were treated by knee arthroscopy during a 2½-year period. All MRIs were reviewed by a pediatric radiologist blinded to clinical findings. Pediatric orthopedic clinic notes were reviewed for pre-surgical evaluation (based on physical exam, radiograph, MR images and radiologist's MRI report). Arthroscopic findings were used as the gold standard. We calculated the percentages of diagnoses at arthroscopy missed on both MRI and pre-surgical evaluation. Diagnostic accuracy between children and adolescents and in patients with one pathological lesion vs. those with >1 lesion was analyzed. We performed a second review of MR images of the missed or over-called MRI diagnoses with knowledge of arthroscopic findings.

RESULTS

We included 178 children and adolescents. The most common diagnoses missed on MRI or pre-surgical evaluation but found at arthroscopy were: discoid meniscus (8/30, or 26.7% of cases); lateral meniscal tears (15/80, or 18.8% of cases); intra-articular loose bodies (5/36, or 13.9% of cases), and osteochondral injuries (9/73, or 12.3% of cases). Overall diagnostic accuracy of MRI and pre-surgical evaluation was 92.7% and 95.3%, respectively. No significant difference in diagnostic accuracy between children and adolescents was observed. When multiple intra-articular lesions were present, lateral meniscal tears were more likely to be inaccurately diagnosed (missed or over-called) on both MRI (P = 0.009) and pre-surgical evaluation (P < 0.001).

CONCLUSION

Overall diagnostic accuracy of MRI and pre-surgical evaluation was quite high. The traumatic intra-articular knee lesions that still pose a diagnostic challenge for MRI and pre-surgical evaluation are lateral discoid meniscus, lateral meniscal tears, intra-articular loose bodies and osteochondral injuries. Special attention should be given to those diagnoses when evaluating a pediatric knee MRI. In children with multiple intra-articular injuries, there is significantly more inaccuracy in pre-arthroscopic diagnosis of lateral meniscal tears on both MRI and pre-surgical evaluation.

The use of magnetic resonance imaging in acute knee injuries can be reduced by non-physician expert clinics

INTRODUCTION

The routine use of magnetic resonance imaging (MRI) for the assessment of acute knee injuries is controversial. The goal of this study is to present an audit of patients seen in a dedicated Acute Knee Injury Clinic (AKIC) to determine the frequency and appropriateness of MRI utilization.

METHODS

A retrospective review identified all patients who had an MRI and a randomly selected control group without MRI. The MRI was classified based on whether it was ordered by the AKIC team or by an external clinician. The consensus-based 'Indications for Urgent MRI in Acute Soft Tissue Knee Problems' were applied to both groups. An MRI was considered appropriate if any of the indications were met.

RESULTS

The overall MRI utilization rate was 23% (142/611). Of the MRIs performed, 32% (46/142) met the indications. About 94% (33/35) of the MRIs ordered by the AKIC experts met the indications, compared to only 12% (13/107) of those ordered externally. No patients in the control group met the indications. Diagnoses were similar between groups.

DISCUSSION

These results suggest that application of guidelines by experts in knee evaluation can significantly reduce expensive MRI utilization in patients with acute knee injuries without negatively impacting the appropriate diagnosis and disposition.

Occult Intra-articular Knee Injuries in Children With Hemarthrosis

BACKGROUND

Hemarthrosis after acute knee trauma is a sign of a potentially serious knee injury. Few studies have described the epidemiology and detailed injury spectrum of acute knee injuries in a general pediatric population.

PURPOSE

To document the current injury spectrum of acute knee injuries with hemarthrosis in children aged 9 to 14 years and to describe the distribution of sex, age at injury, type of activity, and activity frequency in this population.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All patients in the Stockholm County area aged 9 to 14 years who suffered acute knee trauma with hemarthrosis were referred to Astrid Lindgren Children's Hospital, Karolinska University Hospital, from September 2011 to April 2012. The patients underwent clinical examination, radiography, and magnetic resonance imaging (MRI). The type of activity when injured, regular sports activity/frequency, and patient sex and age were registered. The diagnoses were classified into minor and serious injuries.

RESULTS

The study included 117 patients (47 girls and 70 boys; mean age, 13.2 years). Seventy percent had a serious knee injury. Lateral patellar dislocations, anterior cruciate ligament ruptures, and anterior tibial spine fractures were the most common injuries, with an incidence of 0.6, 0.2, and 0.1 per 1000 children, respectively. The sex distribution was equal up to age 13 years; twice as many boys were seen at the age of 14 years. The majority of injuries occurred during sports. Forty-six patients (39%) had radiographs without a bony injury but with a serious injury confirmed on MRI.

CONCLUSION

Seventy percent of the patients aged 9 to 14 years with traumatic knee hemarthrosis had a serious intra-articular injury that needed specific medical attention. Fifty-six percent of these patients had no visible injury on plain radiographs. Physicians who treat this group of patients should consider MRI to establish the diagnosis when there is no or minimal radiographic findings. The most common serious knee injury was a lateral patellar dislocation. This should be taken into consideration to improve prevention strategies and treatment algorithms in pediatric knee injuries.

Epidemiology of hospitalised osteochondritis dissecans in young people: incidence, geographical variation and trends over time in England from 2002 to 2010

BACKGROUND

Osteochondritis dissecans (OCD) is an important cause of knee pain in physically active adolescents, but its aetiology remains controversial. Modern data on its epidemiology are lacking. The aim of this study was to analyse the hospitalised incidence, age and sex distribution, trends over time and geographical variation in OCD in the whole of England.

METHODS

Hospital episode statistics (HES) data were analysed for OCD over the period 2002/3 to 2010/11 for England. HES datasets were record-linked so that anyone with multiple admissions for OCD was counted once only.

RESULTS

The annual incidence rate for hospitalised OCD was 1.58 (95% CI 1.51-1.64) cases per 100,000 population. The peak age at diagnosis was 15-19 years for both sexes, and boys were affected more commonly than girls in the ratio 2:1. The hospitalised incidence of OCD varied significantly across England by government office region, from 1.05 (0.91-1.20) in London to 1.89 (1.70-2.09) in the North West Region.

CONCLUSIONS

These data on the epidemiological features and trends over time in OCD provide new information about its basic epidemiological distribution. Its annual hospitalised incidence is about 1.6 cases per 100,000 population under 25 years, but varies significantly across England. These results have implications for planning rheumatology and orthopaedic services for both children and adults.

Stress-vs-time signals allow the prediction of structurally catastrophic events during fracturing of immature cartilage and predetermine the biomechanical, biochemical, and structural impairment

OBJECTIVE

Trauma-associated cartilage fractures occur in children and adolescents with clinically significant incidence. Several studies investigated biomechanical injury by compressive forces but the injury-related stress has not been investigated extensively. In this study, we hypothesized that the biomechanical stress occurring during compressive injury predetermines the biomechanical, biochemical, and structural consequences. We specifically investigated whether the stress-vs-time signal correlated with the injurious damage and may allow prediction of cartilage matrix fracturing.

METHODS

Superficial and deeper zones disks (SZDs, DZDs; immature bovine cartilage) were biomechanically characterized, injured (50% compression, 100%/s strain-rate), and re-characterized. Correlations of the quantified functional, biochemical and histological damage with biomechanical parameters were zonally investigated.

RESULTS

Injured SZDs exhibited decreased dynamic stiffness (by 93.04±1.72%), unresolvable equilibrium moduli, structural damage (2.0±0.5 on a 5-point-damage-scale), and 1.78-fold increased sGAG loss. DZDs remained intact. Measured stress-vs-time-curves during injury displayed 4 distinct shapes, which correlated with histological damage (p<0.001), loss of dynamic stiffness and sGAG (p<0.05). Damage prediction in a blinded experiment using stress-vs-time grades was 100%-correct and sensitive to differentiate single/complex matrix disruptions. Correlations of the dissipated energy and maximum stress rise with the extent of biomechanical and biochemical damage reached significance when SZDs and DZDs were analyzed as zonal composites but not separately.

CONCLUSIONS

The biomechanical stress that occurs during compressive injury predetermines the biomechanical, biochemical, and structural consequences and, thus, the structural and functional damage during cartilage fracturing. A novel biomechanical method based on the interpretation of compressive yielding allows the accurate prediction of the extent of structural damage.

Usefulness of knee arthroscopy for diagnosis of knee pain in pediatric patients: comparison with preoperative clinical diagnosis

PURPOSE

To investigate the knee arthroscopic findings of pediatric patients with knee pain.

SUBJECTS

Ninety-five knees of 94 patients (46 males and 48 females) aged 15 years or younger who underwent knee arthroscopy during a 4-year period from January 2007 were studied. The mean age at surgery was 13.5 (7-15) years. The mean interval from symptom onset to arthroscopic examination was 6.8 months (5 days to 2 years 10 months).

RESULTS

The most common cause of knee pain was sports-related activities (64 knees). Other causes included falling from a moving bicycle (5 knees), while knee pain appeared with no defined reason in 14 knees. The most frequent final diagnosis based on knee arthroscopic findings was anterior cruciate ligament (ACL) injury (35 knees), followed by discoid lateral meniscus (16 knees), lateral meniscal tear (11 knees), and medial plica syndrome (9 knees), while no arthroscopic abnormality was observed in 8 of 95 knees. Among the 95 knees, the diagnosis based on preoperative physical tests and imaging findings was different from the arthroscopic diagnosis in 16 knees, 8 of which were diagnosed preoperatively as medial meniscal tear.

CONCLUSION

ACL injury and discoid lateral meniscus were the predominant conditions in pediatric patients who underwent knee arthroscopic surgery for knee pain. Knee arthroscopy is useful to provide a definitive diagnosis for knee pain in pediatric patients. Preoperative evaluations had a diagnostic accuracy of only 83.2 % and failed to diagnose conditions such as medial plica syndrome and chondral injury. Therefore, diagnosis before knee arthroscopy has to be interpreted with caution.

Marginal value of radiographs in the interpretation of MR images obtained for pediatric knee pain

OBJECTIVE

Radiographs are often obtained before MRI in the evaluation of pediatric knee pain, but the value of these radiographs is undefined. The purpose of this study was to determine the marginal value of knee radiographs in the interpretation of knee MR images requested by pediatric sports medicine and orthopedic subspecialists.

MATERIALS AND METHODS

Knee MRI examinations of 194 pediatric patients (mean age, 14 [SD, 3.1] years; range 4-18 years) performed over a 3-year period were reviewed retrospectively. Patients were separated into groups based on MRI findings: normal, ligamentous injury, osteochondral injury, or both ligamentous and osteochondral injury. Two pediatric radiologists blinded to the MRI findings reviewed the knee radiographs in consensus and categorized the findings into the same groups. Radiographic and MRI findings were compared, and the influence of radiographic findings on MRI interpretation was designated as noncontributory if radiographic findings did not aid MRI interpretation, erroneous for false-negative and false-positive radiographic findings, or helpful if radiographs aided MRI interpretation.

RESULTS

Radiographic findings were normal in 166 of 194 cases (86%). Among the 166, MRI findings were normal in 73 (44%) cases and abnormal in 93 (56%). Twenty-five of 28 patients (89%) with abnormal radiographic findings had abnormal MRI findings. Radiographs were deemed helpful in 14 of the 25 cases (56%) and noncontributory in 11 (44%). Overall, radiographs were helpful in 14 of 194 cases (7%), noncontributory in 84 (43%), and erroneous in 96 (50%).

CONCLUSION

In the interpretation of knee MRI studies requested by pediatric sports medicine and orthopedic subspecialists for knee pain, radiographs provide limited marginal value. Reliable clinical predictors are needed to identify which subset of pediatric patients with knee pain referred for MRI will benefit from the acquisition of knee radiographs.

Accuracy of 3-Tesla magnetic resonance imaging for the diagnosis of intra-articular knee injuries in children and teenagers

BACKGROUND

Magnetic resonance imaging (MRI) is a commonly used tool for the diagnosis of intra-articular knee pathologies. Although many studies have reported the accuracy of MRI in the adult population, fewer studies have investigated these tests in younger patients. Furthermore, these studies have shown a higher variability in both the sensitivity and the specificity of MRI for these knee injuries in this age group. Advancements in MRI technology, such as the 3-Tesla (3T) MRI magnet, have shown promising results for musculoskeletal injury diagnosis in adults. This study aims to evaluate 3 T MRI for the diagnosis of intra-articular knee pathologies in a pediatric and adolescent patient population.

METHODS

The records of 116 patients (119 knees) under the age of 20 years who underwent 3 T MRI studies of the knee and subsequent knee arthroscopy were reviewed retrospectively. The MRI report from the musculoskeletal radiology staff, the interpretation from the staff orthopedic surgeon, and the operative note dictations were compared, with a focus on meniscus and anterior cruciate ligament (ACL) pathologies. Seventeen orthopedic staff reads were not obtainable. Arthroscopy was used as the gold standard for diagnosis.

RESULTS

The average age at MRI exam was 16.0 years and at surgery was 16.2 years. Using the musculoskeletal radiologist interpretation, the sensitivity and the specificity of 3 T MRI were 81.0% and 90.9% for medial meniscus injuries, 68.8% and 93% for lateral meniscus injuries, and 97.9% and 98.6% for ACL injuries, respectively. The orthopedic surgeon's interpretation of 3 T MRI had a sensitivity and specificity of 75.7% and 92.4% for medial meniscus injuries, 69.8% and 98.3% for lateral meniscus injuries, and 100% and 98.6% for ACL injuries, respectively. Posterior horn tears had the greatest discrepancies.

CONCLUSIONS

When performed on pediatric and adolescent patients, newer 3 T MRI studies have excellent accuracy for diagnosing ACL tears. These studies also show a higher accuracy for the diagnosis of medial meniscal tears than lateral meniscal tears.

LEVEL OF EVIDENCE

Diagnostic study--Level 2.

MRI findings in adolescent patients with acute traumatic knee hemarthrosis

BACKGROUND

Physical examination may be inconclusive in adolescents presenting with an acute traumatic knee effusion because of pain and guarding. The purpose of this study was to describe the magnetic resonance imaging (MRI) findings in adolescents with traumatic knee effusions and to compare injuries based on age, sex, and physeal maturity.

METHODS

All MRIs using a knee trauma protocol performed at our institution over a 2-year period were evaluated. One hundred thirty-one patients between the ages of 10 to 18 years of age with a clinical history of acute knee trauma and an effusion confirmed on MRI met our study inclusion criteria. They were divided into 2 age groups: 10 to 14 and 15 to 18 years old. Pathology was confirmed using clinical history, MRI, and any available surgical reports.

RESULTS

Of the 131 patients with an acute knee effusion, there were 59 patients in the younger group (10 to 14 y old) and 72 patients in the older group (15 to 18 y old). In the younger group, patellar dislocations (36%), anterior cruciate ligament (ACL) tears (22%), and isolated meniscus tears (15%) were the most common injuries. In the older group, ACL tears (40%), patellar dislocations (28%), and isolated meniscus tears (13%) were the most common injuries. ACL injuries represented 28% of injuries in males and 38% of injuries in females, whereas patellar dislocations represented 28% of injuries in males and 37% of injuries in females. There was a trend toward adolescents with active growth plates sustaining more patellar dislocations and adolescents with closed growth plates sustaining more ACL injuries. Forty-one percent of patients in this study underwent surgery.

CONCLUSIONS

Patellar dislocation is a common injury in children who present with a traumatic knee effusion, especially in young adolescents and females. Adolescents presenting with a traumatic knee effusion should undergo MRI because of the high rate of positive findings missed by physical examination and plain radiographs that may warrant surgical repair or reconstruction.

LEVEL OF EVIDENCE

Level III.

Acute traumatic and sports-related osteochondral injury of the pediatric knee

Adolescents are predisposed to osteochondral (OC) injuries in the knee. The medial facet of the patella, the femoral trochlea, and the lateral femoral condyle are the most common sites of injury. Most of these injuries are classically traumatic but noncontact injuries. Surgery is warranted in most cases of OC fracture. Depending on size, condition, and location of the lesion, options include OC fragment reduction and internal fixation or excision and cartilage resurfacing. Understanding of how to diagnose and treat OC fractures will help optimize outcomes.

Review of discoid meniscus

Discoid lateral meniscus is an intra-articular knee disorder that typically presents in children and adolescents. The natural history depends on the type of anomaly and the nature and presence of symptoms. Management of this disorder should be directed toward resolution of the symptoms while preserving meniscal tissue and function. Modern surgical techniques make suturing and preservation of meniscal tissue feasible. In the present article, the clinical manifestations, diagnostic criteria and practical management considerations are reviewed.

The concordance of MRI and arthroscopy in traumatic meniscal lesions in children

INTRODUCTION

Traumatic meniscal lesions in children must be diagnosed quickly and efficiently as a priority in order to conserve the meniscus and safeguard the future of the knee. They are often isolated and difficult to identify clinically. In the diagnostic work up stage, an excessive resort to diagnostic arthroscopy has given way to increasing use of MRI by radiologists without pediatric specialization. The present study examined the agreement between MRI aspect and arthroscopic exploration in traumatic meniscal lesions in children.

PATIENTS AND METHODS

Sixty-nine knees in children aged 9 to 16 years having undergone MRI followed by arthroscopy for knee trauma between 1995 and 2008 were included in a retrospective design. Discoid meniscus was excluded. Files were reviewed by a single clinician and MRI scans by a radiologist specialized in pediatric pathology. Cases of epiphyseal fusion were excluded. All files were analyzable. Agreement with arthroscopic findings as reference was assessed for presence, location and type of meniscal lesion.

RESULTS

Overall agreement with arthroscopy was respectively 78% and 82% on first and second MRI readings: 77% and 80% for the medial, and 78% and 84% for the lateral meniscus. On the first reading, there were 13 false positives for the medial and 5 for the lateral meniscus, versus 9 and 0 respectively on second reading. Overall sensitivity was 70% on first reading and 64% on second, and overall specificity 81% and 90%, respectively.

DISCUSSION

The present results, in line with the literature, may appear encouraging, but hide considerable disparity between analysis of the medial and of the lateral meniscus: MRI overestimated medial and underestimated lateral meniscus lesions.

CONCLUSION

MRI serves only as a support and does not provide sure diagnosis of meniscus lesion. Interpretation should take account of the clinical examination and the pediatric orthopedic specialist's experience.

Pediatric anterior cruciate ligament reconstruction

An increasing number of anterior cruciate ligament (ACL) injuries are seen in children now than in the past due to increased sports participation. The natural history of ACL deficient knees in active individuals, particularly in children is poor. Surgical management of ACL deficiency in children is complex due to the potential risk of injury to the physis and growth disturbance. Delaying ACL reconstruction until maturity is possible but risks instability episodes and intra-articular damage. Surgical options include physeal-sparing, partial transphyseal and complete transphyseal procedures. This article reviews the management of ACL injured skeletally immature patients including the functional outcome and complications of contemporary surgical techniques.

Increase in outpatient knee arthroscopy in the United States: a comparison of National Surveys of Ambulatory Surgery, 1996 and 2006

BACKGROUND

This study was proposed to investigate the changes in the utilization of knee arthroscopy in an ambulatory setting over the past decade in the United States as well as its implications.

METHODS

The National Survey of Ambulatory Surgery, last carried out in 1996, was conducted again in 2006 by the Centers for Disease Control and Prevention. We analyzed the cases with procedure coding indicative of knee arthroscopy or anterior cruciate ligament reconstruction. To produce estimates for all arthroscopic procedures on the knee in an ambulatory setting in the United States for each year, we performed a design-based statistical analysis.

RESULTS

The number of arthroscopic procedures on the knee increased 49% between 1996 and 2006. While the number of arthroscopic procedures for knee injury had dramatically increased, arthroscopic procedures for knee osteoarthritis had decreased. In 1996, knee arthroscopies performed in freestanding ambulatory surgery centers comprised only 15% of all orthopaedic procedures, but the proportion increased to 51% in 2006. There was a large increase in knee arthroscopy among middle-aged patients regardless of sex. In 2006, >99% of arthroscopic procedures on the knee were in an outpatient setting. Approximately 984,607 arthroscopic procedures on the knee (95% confidence interval, 895,999 to 1,073,215) were performed in an outpatient setting in 2006. Among those, 127,446 procedures (95% confidence interval, 95,124 to 159,768) were for anterior cruciate ligament reconstruction. Nearly 500,000 arthroscopic procedures were performed for medial or lateral meniscal tears.

CONCLUSIONS

This study revealed that the knee arthroscopy rate in the United States was more than twofold higher than in England or Ontario, Canada, in 2006. Our study found that nearly half of the knee arthroscopic procedures were performed for meniscal tears. Meniscal damage, detected by magnetic resonance imaging, is commonly assumed to be the source of pain and symptoms. Further study is imperative to better define the symptoms, physical findings, and radiographic findings that are predictive of successful arthroscopic treatment.

Intraarticular stabilization following anterior cruciate ligament injury in children and adolescents

PURPOSE

Significant controversy exists regarding the potential harm to the growth plate following reconstruction of the anterior cruciate ligament in skeletally immature patients. This study was performed to evaluate the results of a transepiphyseal replacement of the anterior cruciate ligament in skeletally immature patients.

METHODS

Ninety-four skeletally immature patients (56 male and 38 female) with median age 13.7 years (range, 11.6-15.9 years) who underwent arthroscopic transphyseal reconstruction of anterior cruciate ligament with four-strand medial hamstring autograft between 1999 and 2006 were reviewed. All patients had been followed up until skeletal maturity was confirmed.

RESULTS

The average follow-up was 38 months (range 24-60 months). Neither leg length discrepancy nor angular deformities were noted on radiological or clinical measurement. Two patients had radiographic evidence of mild arthrosis at final follow-up. New traumatic injuries occurred in 4 patients, in whom surgical revision was performed. Ligament laxity testing with a KT 1000/2000 arthrometer showed no significant difference between the normal and the operated legs. At follow-up, the median Lysholm score was 89 (range 77-100), and the median Tegner activity score was increased from 3 to 6. The International Knee Documentation Committee score was A in 79 patients (84%) and B in 6 patients (6%) and C in 9 patients (9%). Of the 94 patients, 73 (78%) returned to their similar preoperative sport activities and 90% returned to their preoperative level of daily activities.

CONCLUSIONS

ACL reconstruction with medial hamstring autograft via transepiphyseal drilling and grafting yielded satisfactory clinical results with no growth defects in skeletally immature patient. The preliminary results of this series demonstrated that this surgical technique can be performed in prepubescent patients with efficacy and safety.

LEVEL OF EVIDENCE

IV.

Magnetic resonance imaging of the meniscus

Magnetic resonance imaging has evolved into a highly accurate modality in detecting meniscal injuries and provides the essential anatomic detail to help guide treatment options in this age of meniscal preservation. Accurate interpretation requires a thorough understanding of meniscal anatomy and function, anatomic variants, technical factors, typical appearance of tear patterns on magnetic resonance imaging, associated ligamentous injuries, causes of misdiagnoses, and the importance of correlation with the clinical examination.

Current Concepts of Diagnosis and Management of ACL Injuries in Skeletally Immature Athletes

Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are encountered with increasing frequency. The management of such injuries is controversial. Nonsurgical management often results in functional instability and a higher risk of meniscal and chondral injury to the knee. Conventional methods of ACL reconstruction carry the risk of growth disturbance because of iatrogenic damage to the physes around the knee. Multiple cases of growth disturbance have been reported. This article discusses the relevant anatomy, natural history, risk factors, treatment, and prevention of ACL injuries in skeletally immature patients. Surgical treatment is based on physiologic age. For prepubescent patients, we recommend physeal-sparing combined intra-articular/extra-articular reconstruction with autogenous iliotibial band. In adolescent patients with significant growth remaining, we recommend transphyseal ACL reconstruction with hamstrings autograft and fixation away from the physes. In older adolescent patients, we recommend conventional adult ACL reconstruction with autogenous hamstrings or patellar tendon.

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.

Clinical examination, MRI and arthroscopy in meniscal and ligamentous knee Injuries - a prospective study

Data from 565 knee arthroscopies performed by two experienced knee surgeons between 2002 and 2005 for degenerative joint disorders, ligament injuries, loose body removals, lateral release of the patellar retinaculum, plica division, and adhesiolysis was prospectively collected. A subset of 109 patients from the above group who sequentially had clinical examination, MRI and arthroscopy for suspected meniscal and ligament injuries were considered for the present study and the data was reviewed. Patients with previous menisectomies, knee ligament repairs or reconstructions and knee arthroscopies were excluded from the study. Patients were categorised into three groups on objective clinical assessment: those who were positive for either meniscal or cruciate ligament injury [group 1]; both meniscal and cruciate ligament injury [group 2] and those with highly suggestive symptoms and with negative clinical signs [group 3]. MRI was requested for confirmation of diagnosis and for additional information in all these patients. Two experienced radiologists reported MRI films. Clinical and MRI findings were compared with Arthroscopy as the gold standard. A thorough clinical examination performed by a skilled examiner more accurately correlated at Arthroscopy. MRI added no information in group 1 patients, valuable information in group 2 and was equivocal in group 3 patients. A negative MRI did not prevent an arthroscopy. In this study, specificity, positive and negative predictive values were more favourable for clinical examination though MRI was more sensitive for meniscal injuries. The use of MRI as a supplemental tool in the management of meniscal and ligament injuries should be highly individualised by an experienced surgeon.

The discoid meniscus

Discoid lateral meniscus is an intra-articular knee disorder typically presented in the young population and during adolescence. Different types of meniscal disorders and varied forms of presentation have been reported. The natural history depends on the type of anomaly and the presence of symptoms. Management of the disorder should be directed toward the resolution of the symptoms while preserving meniscal tissue and function. Modern surgical techniques enable suturing and preservation of meniscal tissue. The clinical manifestations, diagnostic modalities and criteria, accompanying conditions and practical management considerations are reviewed.

Lower extremity injuries in the skeletally immature athlete

The heightened intensity of training and competition among young athletes places them at increased risk for both acute and chronic injuries. Prompt recognition and treatment of such injuries are critical to prevent long-term functional disability and deformity. These injuries occur in patterns unique to the skeletally immature athlete, given their developing epiphyses and ossification centers and supporting ligamentous structures. Children and adolescents who participate in recreational and organized sports are particularly susceptible to a broad spectrum of lower extremity injuries involving both the osseous and soft-tissue structures. Fundamental knowledge of the pathophysiology of injury helps the clinician in determining management. Early recognition of acute traumatic injuries, along with preventive regimens and knowledge of both nonsurgical and surgical treatment protocols, has helped to restore and maintain normal lower extremity function in the skeletally immature athlete.

Surgical management of anterior cruciate ligament injuries in patients with open physes

Because of the increasing number of skeletally immature athletes who compete in highly demanding sports, more children than previously are sustaining anterior cruciate ligament injuries. Treatment and patient compliance with treatment recommendations are problematic. Pediatric issues include those specific to evaluation, projected growth, and surgery. Strict activity modification can protect the knee from further injury and delay surgery, sometimes until maturity. Surgical options include physeal-sparing, partial transphyseal, and complete transphyseal procedures. Surgical procedures are demanding because typical drilling and fixation techniques can affect the physis and possibly lead to growth disturbances. A wide range of growth disturbances has been reported; these must be understood to perfect surgical technique and avoid potential growth concerns. Surgical challenges, options regarding delayed surgery, and possible outcomes all need to be clearly communicated to the patient and parents.

Accuracy of 3-T MRI Using Fast Spin-Echo Technique to Detect Meniscal Tears of the Knee

OBJECTIVE

The purpose of this study was to evaluate the accuracy of the fast spin-echo technique in detecting meniscal tears of the knee using a 3-T MRI system.

CONCLUSION

We concluded from this study that 3-T MRI using fast spin-echo sequences is highly accurate in the detection of medial and lateral meniscal tears of the knee.

3T MR Imaging of the Musculoskeletal System (Part II): Clinical Applications

The gain in SNR that is afforded by 3T MR imaging systems has tremendous clinical applications in the musculoskeletal system. The potential for demonstrating and enhancing the visibility of normal osseous, tendinous, cartilaginous, and ligamentous structures is exciting. Furthermore, harnessing this added signal to increase spatial resolution may improve our diagnostic abilities in various joints dramatically. Radiologists have enjoyed great success in assessing joint disease with current MR imaging field strengths; however, many intrinsic joint structures remain poorly evaluated, which leads to a golden opportunity for 3T MR imaging. The articular cartilage of the knee, the glenoid labrum of the shoulder, the intrinsic ligaments and TFC of the wrist, the collateral ligaments of the elbow, the labrum and articular cartilage of the hip, and the collateral ligaments of the ankle have been evaluated suboptimally on 1 .5T systems using routine nonarthrographic MR images. Because of the enhanced SNR, the higher spatial resolution, and the greater CNR of intrinsic joint structures at higher field strengths, 3T MR imaging has the potential to improve diagnostic abilities in the musculoskeletal system vastly, which translates into better patient care and management. The author's 2 years of clinical experience with musculoskeletal MR imaging on 3T systems has met and exceeded his expectations, and has bolstered the confidence of his orthopedic surgeons in his diagnoses. As coil technology advances and as the use of parallel imaging becomes more available in the extremities, the author expects to see even more dramatic improvements in image quality.

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.

Injury-related causes of acute knee pain

This detailed overview covers the anatomy, function, and examination of the knee and describes the phases of treatment for acute knee pain secondary to injury.

Intra-articular traumatic disorders of the knee in children and adolescents

Intra-articular knee injuries in children traditionally have been considered rarer than injuries in adults. Few studies establish the prevalence of knee injuries before skeletal maturity, but arthroscopic studies suggest an increased frequency of anterior cruciate ligament ruptures, meniscal tears, and osteochondral fractures. We report our experience with 15 anterior cruciate ligament injuries and 38 meniscus injuries treated between 1996 and 2001. The treatment of anterior cruciate ligament injuries is determined by Tanner's maturity criteria. In the three cases of Stage II injuries, surgery was delayed for up to 24 months in the 12 older patients, an immediate reconstruction was done using hamstring tendons in the three youngest patients, and patellar tendon treatment was done in the remaining cases. We had only one complication caused by the fracturing of the bone plug. The most frequent meniscus injuries were the traumatic tears (23 cases), 80% of which were peripheral and longitudinal. Whenever possible, the entire meniscus (suture in 4 cases) or the greater part of it (economic resection in 19 cases) should be conserved. Despite the satisfactory results, the average followup of the meniscal series (26.1 months) is too short a period to evaluate thoroughly the deterioration of the joint after a meniscectomy.

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.

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.