What is the best next step in managing a 14-year-old boy with progressive right groin pain, limp, and muscle atrophy, without fever, night sweats, or weight loss, and with normal vital signs, including hyperlordosis (increased inward curvature of the lower back) and Trendelenburg gait (abnormal gait with pelvis drop), and impaired strength on knee extension?

From the Guidelines

The best next step in management for this 14-year-old boy with right groin pain is bilateral hip x-rays (option A). This patient presents with classic signs of slipped capital femoral epiphysis (SCFE), a common hip disorder in adolescents, as described in the consensus recommendations on the classification, definition, and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018 1. The clinical findings strongly support this diagnosis: progressive groin pain exacerbated by activity, limping, outward rotation of the affected foot, positive Trendelenburg sign (dropping of the pelvis when standing on the affected leg), and quadriceps atrophy. SCFE typically occurs during periods of rapid growth in adolescence, and the patient's height tracking along the 75th percentile suggests he is in a growth phase. The absence of systemic symptoms like fever or weight loss makes infectious or malignant causes less likely. Bilateral hip x-rays are essential as the initial imaging study because they can directly visualize the slippage of the femoral head relative to the femoral neck. Early diagnosis is crucial as delayed treatment can lead to avascular necrosis, chondrolysis, and early osteoarthritis. Some key points to consider in the diagnosis of hip-related pain in young and middle-aged active adults include:

• Excluding non-musculoskeletal and serious hip pathological conditions, such as tumors, infections, stress fractures, and slipped capital femoral epiphysis, as well as competing musculoskeletal conditions, such as lumbar spine conditions 1.
• Considering the most common hip conditions in young and middle-aged active adults presenting with hip-related pain, including femoroacetabular impingement (FAI) syndrome, acetabular dysplasia, and other conditions without a distinct osseous morphology (labral, chondral, and/or ligamentum teres conditions) 1. While other tests like MRI, nerve conduction studies, creatine kinase measurement, or muscle biopsy might be considered for different conditions, they would not be appropriate first steps given the clinical presentation strongly suggesting a hip disorder rather than a neurological, muscular, or spinal condition. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define, and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom 1. In the context of hip-related pain, it is essential to consider the classification of hip pain, patient-reported outcomes, standardized measurement of physical capacity, and physiotherapist-led treatment, as outlined by the International Hip-related Pain Research Network 1. Additionally, the management of chondral injuries of the hip is complex and challenging, and joint-preserving surgical options, such as microfracture, articular cartilage repair, autologous chondrocyte implantation, mosaicplasty, and osteochondral allograft transplantation, may be considered in certain cases 1. However, in this patient's case, the clinical presentation and age suggest that SCFE is the most likely diagnosis, and bilateral hip x-rays are the best next step in management.

From the Research

Diagnosis and Management of Hip Disorder

The patient's symptoms, such as intermittent right groin pain, limp, and difficulty climbing stairs, are consistent with a hip disorder. The physical examination findings, including mild atrophy of the right quadriceps and gluteal muscles, and the patient's gait, suggest a possible diagnosis of slipped capital femoral epiphysis (SCFE) 2, 3, 4, 5, 6.

Diagnostic Imaging

The best next step in management of this patient would be to confirm the diagnosis using bilateral hip radiography, which should include anteroposterior and frog-leg views in patients with stable SCFE, and anteroposterior and cross-table lateral views in unstable SCFE 2. This is because:

• SCFE is a common hip disorder in adolescents, and early diagnosis is crucial to prevent complications 2, 3, 4, 5, 6.
• Bilateral hip radiography is the initial modality used to evaluate patients with painful hip joints 3.
• Ultrasonography and magnetic resonance imaging (MRI) can also be used, but plain radiograph is the most commonly used initial modality 3.

Treatment Options

The treatment of SCFE aims to prevent slip progression and avoid complications such as avascular necrosis, chondrolysis, and femoroacetabular impingement 2, 4, 5, 6. The treatment options include:

• In situ screw fixation for stable SCFE 2, 5.
• Urgent hip joint aspiration followed by closed reduction and single- or double-screw fixation for unstable SCFE 5.
• Osteotomy or recontouring of the femoral neck to reduce the resulting cam-deformity 6.

Best Next Step

Based on the patient's symptoms and physical examination findings, the best next step in management would be to order bilateral hip x-rays to confirm the diagnosis of SCFE. This is because bilateral hip radiography is the most commonly used initial modality to evaluate patients with painful hip joints, and it can help confirm the diagnosis of SCFE 2, 3.

Some key points to consider are:

• The patient's age and symptoms are consistent with SCFE 2, 3, 4, 5, 6.
• The physical examination findings suggest a possible diagnosis of SCFE 2, 3, 4, 5, 6.
• Bilateral hip radiography is the initial modality used to evaluate patients with painful hip joints 3.