The irritable hip: immediate ultrasound guided aspiration and prevention of hospital admission

Paediatric acute non-traumatic limp presenting to the emergency department: a retrospective observational study

BACKGROUND

Acute non-traumatic limp in children has many causes, ranging from common benign and self-limiting disease to serious time-sensitive emergencies such as septic arthritis. We aimed to (1) describe the epidemiology and workup of paediatric acute non-traumatic limp presentation in three Australian EDs and (2) compare investigations and treatment between a tertiary paediatric centre and two non-tertiary centres.

METHODS

A retrospective chart review of children aged 0-16 years, with an initial presentation of non-traumatic limp to three EDs in Melbourne, Australia. Data on presentation, management and outcomes was systematically collected on all eligible patients.

RESULTS

Of 63 941 presentations over a 12-month period, 475 (0.7%) met inclusion criteria. The median (IQR) age of presentation was 5 (3-8) years, with a male predominance (61%). Blood tests and imaging were performed in 39% and 51%, respectively. 34% of presentations had no investigations. The most frequent ED diagnoses were transient synovitis (37%) and viral myositis (16%). 84% were discharged home after ED evaluation. Compared with the two non-tertiary hospitals, children who presented to the tertiary centre were less likely to have any investigation performed (OR=0.41, 95% CI: 0.27 to 0.62, p<0.001) and more likely to be discharged home after evaluation (OR=4.67, 95% CI: 2.79 to 7.81, p<0.001).

CONCLUSION

Although mostly due to benign disorders, an important number of limping children who presented to the ED had serious disease, with approximately one-third of these not diagnosed at the initial ED visit. There is large variation in workup including blood test, imaging and decisions regarding ED disposition.

Non-traumatic limping in Paediatric Emergencies: Epidemiology, evaluation and results

INTRODUCTION

Non-traumatic limping is a common reason for consultation in paediatric emergencies. Although transient synovitis of the hip (TS) is the most frequent diagnosis, there are cases of limping secondary to serious pathologies. The aim of this review is to describe the variables related to non-traumatic limp that come to the paediatric emergency department to establish the best management protocol, making the most of resources and speeding up emergency care.

MATERIAL AND METHOD

A prospective study was conducted, selecting all children less than 15 years old who consulted aspaediatric emergencies for non-traumatic limping during the 2014. Clinical variables, complementary examinations and diagnoses were collected in the emergency room consultation and 6 months after the consultation RESULTS: During 2014, 146 patients (0.69% of the emergencies) were included in the non-traumatic limping study. Four cases of severe limping were diagnosed: 2 leukaemias, 1 septic arthritis and 1 acetabular bone tumour. The most frequent diagnosis was TS (53.16%). At 6 months, 135 children (92.4%) had resolved lameness. The diagnosis was changed in 9 children (6.1%). Children with TS had fewer days of evolution, and 77% were between 3 and 10 years old. Children with a final diagnosis of severe pathology had a limp for longer, fever and did not weight bear on ambulation.

CONCLUSIONS

In limping of probable hip origin, at the ages of between 3 and 10, without fever or systemic symptoms and of less than one week's onset, it is possible to make a clinical diagnosis of TS limiting the use of complementary examinations.

Ultrasound-guided hip arthrocentesis in a child with hip pain and Fever

Children presenting to the emergency department with hip pain and fever are at risk for significant morbidity due to septic arthritis. Distinguishing between septic arthritis and other causes of hip pain may be challenging. Sonographic visualization of the hip with real-time ultrasound-guided arthrocentesis may allow faster differentiation between etiologies, hastening definitive therapy and improving analgesia. This report describes the use of hip sonography in a case of Lyme arthritis. The authors review the medical literature in support of bedside hip sonography and discuss how to perform ultrasound-guided hip arthrocentesis. Clinical findings in septic and Lyme arthritis are also described.

Ultrasound-guided hip arthrocentesis in the ED

In patients presenting with atraumatic joint pain and swelling, diagnosis is typically made by synovial fluid analysis. Management of an acute suspected hip joint arthritis can present a challenge to the emergency physician (EP). Hip joint effusions are somewhat more difficult to identify and aspirate than effusions in other joints that are commonly managed by EPs. Identification and aspiration of a hip joint effusion under ultrasound guidance is a well-established procedure in the fields of orthopedic surgery and interventional radiology. Here, we report 4 cases of ultrasound-guided hip arthrocentesis at the bedside by EPs; relevant technical details of the procedure are reviewed. These cases demonstrate the feasibility of ultrasound-guided hip arthrocentesis in the emergency department (ED) by EPs. With increasing availability of bedside ultrasound in the ED, suspected hip joint arthritis or infection may be evaluated and managed by the trained EP in a fashion similar to other joint arthritides.

Échographie pédiatrique ostéo-articulaire

Ultrasound examination is often the most effective and sometimes the only practical means of examining children with soft tissue, tendon and joint diseases. This review will cover the important application of diagnostic ultrasound in children musculoskeletal disorders. We will consider topics where ultrasound is the only sensible means of examination such as developmental dysplasia of the hip, where it is the best choice of several possible methods such as painful hip and when it provides an alternative or adjunct to other imaging such as the examination of soft tissue masses.

Differentiation between septic arthritis and transient synovitis of the hip in children with clinical prediction algorithms

BACKGROUND

Differentiation between septic arthritis and transient synovitis of the hip in children can be difficult. Kocher et al. recently developed a clinical prediction algorithm for septic arthritis based on four clinical variables: history of fever, non-weight-bearing, an erythrocyte sedimentation rate of >or=40 mm/hr, and a serum white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L). The purpose of this study was to apply this clinical algorithm retrospectively to determine its predictive value in our patient population.

METHODS

A retrospective review was performed to identify all children who had undergone a hip arthrocentesis for the evaluation of an irritable hip at our institution between 1992 and 2000. One hundred and sixty-three patients with 165 involved hips satisfied the criteria for inclusion in the study and were classified as having true septic arthritis (twenty hips), presumed septic arthritis (twenty-seven hips), or transient synovitis (118 hips).

RESULTS

Patients with septic arthritis (true and presumed; forty-seven hips) differed significantly (p < 0.05) from patients with transient synovitis (118 hips) with regard to the erythrocyte sedimentation rate, differential of serum white blood-cell count, total white blood-cell count and differential in the synovial fluid, gender, previous health-care visits, and history of fever. If the four independent multivariate predictors of septic arthritis proposed by Kocher et al. were present, the predicted probability of the patient having septic arthritis was 59% in our study, in contrast to the 99.6% predicted probability in the patient population described by Kocher et al. Statistical analyses demonstrated that the best model to describe our patient population was based on three variables: a history of fever, a serum total white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L), and a previous health-care visit. When all three variables were present, the predicted probability of the patient having septic arthritis was 71%.

CONCLUSIONS

Although the use of a clinical prediction algorithm to differentiate between septic arthritis and transient synovitis may have improved the utility of existing technology and medical care to facilitate the diagnosis at the institution at which the algorithm originated, application of the algorithm proposed by Kocher et al. or of our three-variable model does not appear to be valid at other institutions.

Ultrasound-guided aspiration of the hip in children: a new technique

Evaluation of the child presenting with an irritable hip often requires aspiration of the hip. There are various methods for doing this procedure. We present a new technique for hip aspiration using high-resolution ultrasound imaging with color Doppler and a needle guide. This technique maximizes chances for a successful aspiration, minimizes risks to the child, avoids radiation exposure, and is easy to do and teach.

A randomized clinical trial: should the child with transient synovitis of the hip be treated with nonsteroidal anti-inflammatory drugs?

STUDY OBJECTIVES

The diagnosis of transient synovitis of the hip ("irritable hip") is made frequently in the pediatric emergency department. We hypothesized that an anti-inflammatory agent (ibuprofen syrup) would shorten the duration of symptoms.

METHODS

Patients who were clinically diagnosed with transient synovitis of the hip in the ED between July 1997 and July 1998 were randomized in a double-blind, placebo-controlled trial to receive either ibuprofen syrup (10 mg/kg 3 times a day for 5 days) or placebo. There were stringent exclusion criteria, and patients were only included if there was a low index of suspicion of more serious pathology. All patients had a hip ultrasonography performed at enrollment and at day 7. Symptoms were monitored by the use of a parental diary and clinical review.

RESULTS

Forty patients were initially enrolled, but 4 patients were subsequently excluded, leaving 17 patients in the ibuprofen group and 19 in the placebo group. Although symptoms resolved in more than 80% (30 of 36) of patients in both groups by 7 days, the median duration of symptoms was shorter in the ibuprofen group (2 days compared with 4.5 days in the placebo group; P =.05 on Wilcoxon-Breslow test). The medication was well tolerated, with only minor gastrointestinal side effects being reported by 6 patients (4 ibuprofen and 2 placebo).

CONCLUSION

In this small study, ibuprofen shortened the duration of symptoms in children with a clinical diagnosis of transient synovitis of the hip.

Review article: diagnostic ultrasonography: applications in orthopaedic surgery

Diagnostic ultrasonography of musculoskeletal diseases in the United States has been used most often for detection of rotator cuff tears or developmental dysplasia of the hip. Diagnostic ultrasonography also is useful in imaging the periarticular soft tissues about the knee, hip, ankle, occult pediatric fractures, muscle injury, bone healing, and foreign bodies. Recent technologic improvements have made this imaging modality increasingly more accurate while providing significant benefits over traditional modalities such as magnetic resonance imaging, particularly regarding cost, patient satisfaction, and ease of usage. Increasing use in the future of diagnostic ultrasonography for musculoskeletal conditions is likely as acceptance grows. This review focuses on recent, practical applications of diagnostic ultrasonography of the musculoskeletal system.

Transient synovitis: is there a need to aspirate hip joint effusions?

There is debate as to the optimal management of children with hip joint effusions especially regarding the decision to aspirate. The objective of this study was to determine whether there is a need to aspirate hip joint effusions detected on ultrasound in patients with clinical transient synovitis (TS) and to identify the natural history of these effusions. Twenty-five children with proven hip joint effusions were followed up sequentially by clinical and radiological examination until symptom free. The mean age was 6 years with equal right/left distribution. No child underwent hip aspiration and no cases of sepsis were missed. The median size of hip effusion detected on ultrasound at presentation was 9 mm. At 7 days 60% (15/25) of patients had a normal clinical examination with no detectable effusion on ultrasound. At 14 days 16% (4/25) had an effusion detectable on ultrasound but they were all pain and limp free and their effusions were reducing in size. These results support the known benign nature of TS and that it will settle with conservative treatment.

Magnetic resonance imaging as the primary imaging modality in children presenting with acute non-traumatic hip pain

The role of magnetic resonance imaging (MRI) in children presenting with acute non-traumatic hip pain was evaluated prospectively. Hip MRI was performed in addition to standard investigations (arthrosonography +/- hip radiographs) in 50 children presenting to the accident and emergency department of a paediatric hospital. MRI was performed on an open 0.23T system and comprised gradient echo T1 weighted coronal, fast spin echo T2 weighted coronal and inversion recovery spin echo (IRSE) axial sequences. Diagnostic quality MRI examinations were obtained in 94% of children. The IRSE sequence was the most reliable at determining underlying disorder (p<0.002). Interobserver agreement on the MRI examinations was very good with unweighted kappa value of 0.89, 95% confidence intervals 0.79, 0.99. Sensitivity of MRI was 0.79 (0.68, 0.90, specificity 1.00 (0.89, 1.00), accuracy 0.81 (0.70, 0.92), PPV 1.00 (0.89, 1), NPV 0.36 (0.25, 0.47). Sensitivity of standard imaging was 0.70 (0.54-0.86), specificity 0.57 (0.41, 0.73), accuracy 0.72 (0.56, 0.88), PPV 0.91 (0.75, 1.00), NPV 0.24 (0.08, 0.40). MRI correctly identified all seven children with serious underlying disorder whereas conventional imaging correctly diagnosed only two. Pelvic musculoskeletal infection was associated with the combination of marked alteration in signal in tissues adjacent to a symptomatic hip and an erythrocyte sedimentation rate of >20 mm 1st h (p<0.0001). In conclusion, MRI is a practical, well accepted and accurate non-invasive imaging technique in children presenting with acute non-traumatic hip pain. Combined with inflammatory markers MRI can be used to determine those children who require aggressive management. Where it is available, MRI is the imaging modality of choice in this condition.

Transient synovitis as a cause of painful limps in children

Transient synovitis of the hip is one of the most common causes of hip pain and limp in young children. Its cause is still largely unknown, but its natural history is that of a self-limiting disorder with no residual sequelae, although recurrences are possible. Because this benign condition is similar to more significant disorders, such as septic arthritis, the diagnosis should remain one of exclusion. Once transient synovitis is diagnosed, treatment consists of rest, anti-inflammatory agents, and a tincture of time.

Ultrasound guided reduction of pediatric forearm fractures in the ED

Reducing badly displaced or angulated pediatric forearm fractures in the emergency department can be difficult. Multiple attempts at reduction may be required, with repeated trips to the radiology department, before an adequate reduction is achieved. We have recently found that bedside ultrasound by emergency physicians is very helpful in guiding the reduction of difficult forearm fractures, allowing the physician to assess the adequacy of the reduction at the patient's bedside. In this report, we describe the technique we have developed for ultrasound-guided fracture reduction and present three case histories showing the usefulness of this technique.

Seven year follow up of children presenting to the accident and emergency department with irritable hip

OBJECTIVE

To assess an established protocol for managing children with irritable hip in the accident and emergency department.

METHODS

Retrospective seven year follow up of all children managed under an established hip pain protocol. The main outcome measure was of failure of the protocol to identify serious pathology.

RESULTS

A total of 103 children met the criteria for assessment using the protocol. Sixty were allowed home, and outpatient follow up arranged. All of these children except one were diagnosed as having transient synovitis. This child had Perthes' disease and was diagnosed at first presentation. Forty three children were admitted, with eight subsequently having a diagnosis other than transient synovitis of the hip. It was possible to review 80 children seven years later. Of these children no long term problems were encountered.

CONCLUSION

The protocol used in the department for children with irritable hip is successful in identifying those children with transient synovitis of the hip, or other benign causes, and therefore not requiring hospital admission. Long term follow up showed that no serious pathology was missed.

Pediatric hip sonography. Diagnosis and differential diagnosis

As with any sonographic study, the accuracy of the examination is related to the skill and experience of the examiner. In this review of pediatric hip sonography, we have reviewed pitfalls and differential diagnoses for the infant suspected of DDH and for the older child presenting with a painful hip. The learning process for DDH evaluation is prolonged and more difficult than learning to assess the hip for effusion.

Common hip injuries in sport

As a major weight-bearing joint, normal hip function is fundamental to successful sporting participation. Not only is it important in running-, jumping- and kicking-based activities, it also contributes to the generation and transference of forces in upper limb-dominated activities. Injuries to the hip do not account for a large proportion of the sports physician's workload, but may result in significant morbidity. The wide variety of acute, subacute and chronic injuries, affecting both the joint and surrounding soft tissues, can prove a diagnostic dilemma. The predisposition and the types of injuries around the hip vary with the age of the athlete. The young child rarely sustains a significant injury but one should be aware of orthopaedic conditions common in this age group that may manifest themselves through exercise. The immature skeleton of the adolescent is relatively injury prone and the demands of sport often exceed the capacity of the growing musculoskeletal system. In adults and older athletes, a further spectrum of injury exists, along with the effects of aging tissues and the concerns of degenerative joint disease. Rational treatment is based on a clear diagnosis developed through sound knowledge and a thorough history and examination. For the sports physician, treatments are typically early physical therapy and structured, progressive rehabilitation programmes which are individualised to the needs of the athlete. The spectrum of hip injuries is reviewed with current recommended diagnoses and management.

Hip pain in an adolescent

We have described a case of osteomyelitis of the ischium with extension into the adjacent soft tissues and abscess formation. Diagnosis and treatment were initially delayed due to the assumption that edema in the thigh muscles seen on initial MRI represented polymyositis. Subsequent radiographs demonstrated a destructive lesion containing a sequestrum within the ischium, indicative of osteomyelitis. It was, however, the MRI imaging that dramatically demonstrated the full extent of the complicating abscess which extended downward to mid-thigh and upward under the gluteal muscles almost to the top of the iliac crest. This proved to be an invaluable guide for the surgeon.