Elbow Locking in a 14-Year-Old: Evaluation and Management
This 14-year-old boy most likely has a loose body or osteochondritis dissecans (OCD) causing mechanical locking, and you should obtain plain radiographs of the elbow as the initial imaging study, followed by MRI without contrast if radiographs are normal or indeterminate, with referral to orthopedic surgery for definitive treatment.
Initial Diagnostic Approach
Plain Radiographs First
Start with standard elbow radiographs (AP, lateral, and oblique views). The ACR Appropriateness Criteria 1 establishes radiographs as the initial imaging modality for elbow pathology. While this guideline focuses on acute trauma, the principle of starting with plain films applies to mechanical symptoms.
Key Clinical Features to Assess
- True mechanical locking (inability to move through full range without manipulation) versus pseudo-locking (pain-limited motion)
- Specific position where locking occurs (typically extension with loose bodies)
- History of trauma (even remote injury can lead to loose bodies or post-traumatic arthrofibrosis)
- Associated symptoms: pain, swelling, clicking, catching
- Duration and frequency of locking episodes
Most Likely Diagnoses
Osteochondritis Dissecans (OCD)
This is the most common cause of true mechanical locking in this age group. OCD accounts for 60% of elbow arthroscopy indications in pediatric patients 2. The capitellum is the typical location, and loose fragments can cause intermittent locking.
Loose Bodies
These can result from:
- Previous undiagnosed trauma
- OCD lesions that have detached
- Post-traumatic cartilage or bone fragments
Post-Traumatic Arthrofibrosis
Less likely given the intermittent nature, but consider if there's history of elbow injury. This typically presents with progressive stiffness rather than episodic locking 3, 4.
Advanced Imaging When Needed
If radiographs are normal or indeterminate, proceed directly to MRI without contrast 1. The ACR guidelines note that noncontrast MRI is appropriate for soft tissue and ligamentous assessment, and this applies equally to intra-articular pathology like OCD and loose bodies.
- Do not order CT unless evaluating complex fracture patterns
- Do not order ultrasound for this indication—while US can assess some elbow pathology 5, it cannot adequately visualize intra-articular loose bodies or OCD lesions
- Do not order bone scan—no role in this clinical scenario 1
Management Algorithm
If OCD or Loose Bodies Confirmed:
Refer to pediatric orthopedic surgery for definitive management
Arthroscopic removal is the standard approach:
Activity modification until surgical evaluation—avoid repetitive throwing or impact activities that could worsen fragment displacement
If Post-Traumatic Stiffness Without Loose Bodies:
This is less consistent with the described "locking" but if present:
- Conservative management first: physical therapy, serial casting, or dynamic splinting
- Closed manipulation under anesthesia if conservative measures fail after 6 months 3
- Surgical contracture release only if manipulation fails 6
Critical Pitfalls to Avoid
Do not dismiss this as "just stiffness"—true mechanical locking indicates an intra-articular mechanical block (loose body or unstable OCD fragment) that requires surgical removal. Conservative management will not resolve this.
Do not delay imaging—while some pediatric elbow conditions can be managed conservatively, mechanical locking suggests a surgical lesion. Early diagnosis prevents further cartilage damage from the loose fragment.
Do not attempt manipulation without imaging—unlike nursemaid's elbow (pulled elbow) which occurs in younger children (typically <5 years) and has a distinct mechanism 7, 8, this presentation in a 14-year-old with positional locking requires imaging before any manipulation.
Recognize the 12% reoperation rate in pediatric elbow arthroscopy 2—counsel families that while initial surgery is usually successful, some patients require subsequent procedures for recurrent or new problems.
Age-Specific Considerations
At 14 years old, this patient is in the higher-risk age group for elbow pathology. Older pediatric patients (15-18 years) show greater improvements with surgical intervention compared to younger children 6, but they also have different injury patterns than younger children. The AAOS guidelines acknowledge that adolescents require specific consideration but lack strong evidence for treatment protocols 9.