Laboratory Workup for a 17-Year-Old Girl with Non-Healing Bone Bruise and Meniscal Tear
For a 17-year-old girl with a non-healing bone bruise and meniscal tear, comprehensive laboratory testing should include serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone, 25-hydroxyvitamin D, and a urinary calcium/creatinine ratio to evaluate for underlying metabolic bone disease.
Initial Laboratory Evaluation
The following laboratory tests should be ordered:
Basic Metabolic Panel
- Serum calcium
- Phosphorus
- Alkaline phosphatase (may be elevated with healing fractures)
Bone Metabolism Assessment
- Parathyroid hormone (PTH)
- 25-hydroxyvitamin D
- Urinary calcium excretion (random urinary calcium/creatinine ratio)
Additional Tests to Consider
- Complete blood count (CBC) to assess for underlying inflammatory conditions
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to evaluate for inflammation
- Thyroid function tests (TSH, free T4) as thyroid disorders can affect bone healing
Rationale for Testing
The American Academy of Pediatrics recommends that in children with fractures or injuries that are not healing properly, serum calcium, phosphorus, and alkaline phosphatase should be reviewed 1. Additionally, serum concentrations of parathyroid hormone and 25-hydroxyvitamin D, as well as urinary calcium excretion should be assessed, particularly if there is radiographic evidence of poor healing or metabolic bone disease 1.
Non-healing bone injuries in adolescents may indicate underlying metabolic bone disease that could be contributing to delayed healing. Studies have shown that bone bruises in adolescents are often associated with meniscal tears 2, but persistent non-healing suggests potential metabolic factors that require investigation.
Imaging Considerations
While laboratory testing is being performed, additional imaging may be warranted:
MRI is the preferred second-line imaging modality when evaluating persistent bone bruises and meniscal tears, with near 100% sensitivity for detecting bone marrow contusions and occult fractures 3.
Follow-up MRI can help assess healing progress and identify any additional soft tissue injuries that may be contributing to delayed recovery.
Clinical Implications
Research has demonstrated that bone bruises, particularly when located at the tibial plateau, are significantly associated with meniscal tears 4. A study by Bone et al. found that bone bruising at the lateral tibial plateau (LTP) was significantly associated with lateral meniscus tears (odds ratio 4.0), while bone bruising at the medial tibial plateau (MTP) was strongly associated with medial meniscus tears (odds ratio 40.5) 4.
The presence of both a bone bruise and meniscal tear in this 17-year-old suggests a more complex injury pattern that may require additional evaluation beyond standard approaches.
Treatment Considerations
While laboratory results are pending:
- Activity modification should be implemented
- Weight management is recommended if the patient is overweight to reduce knee load
- Cryotherapy (ice application through a wet towel for 10-minute periods) can provide short-term pain relief and reduce swelling
- Consider acetaminophen as first-line medication, with NSAIDs as second-line if acetaminophen is insufficient 3
When to Consider Referral
Orthopedic referral should be considered if:
- Laboratory tests reveal metabolic abnormalities
- Conservative management fails after 6-8 weeks
- Persistent mechanical symptoms are present
- Progressive instability occurs despite rehabilitation
Pitfalls to Avoid
Don't assume normal healing timeframes apply to all patients - Adolescents with bone bruises typically recover within 7 months 5, but metabolic factors can significantly delay this process.
Don't overlook vitamin D deficiency - This is common in adolescents and can significantly impact bone healing.
Don't focus solely on the meniscal tear - The non-healing bone bruise may indicate an underlying systemic issue that requires addressing for successful recovery.
Don't rush to surgical intervention - Most isolated bone bruises resolve with conservative management 5, and addressing any metabolic abnormalities may improve healing without surgery.