A 16 year and 7-month-old African American female, who participates in multiple sports including cheer, softball, and competitive volleyball, presents with 5 months of worsening atraumatic bilateral anterior leg pain. She normally trains 6 h per day and 4 days per week. Initially, her pain only occurred with sports-related activities; however, after a recent 3-day volleyball tournament, her pain acutely worsened, yet improved with rest.
She denied prior history of stress fractures, multiple previous fractures, and a family history of bone diseases, such as osteogenesis imperfecta. She is otherwise healthy with menarche at age 11 and reported normal cycles. The mother reported the patient had no dietary concerns but could be eating healthier. The patient had a normal BMI, with no concerning signs of metabolic or hormonal abnormalities.
After obtaining radiographs and a physical exam, the patient was found to have bilateral multiple anterior cortex mid-tibial diaphyseal stress fractures. Three focal lucencies were noted over the anterior cortex of the right mid-tibial diaphysis and one over the left with bilateral cortical thickening and periosteal reaction (Figure 1).
Bone metabolic labs and bilateral lower extremity CT scans were obtained. The patient's serum calcium was normal at 9.4 mg/dL, but her 25-hydroxy vitamin D resulted low at 17 ng/mL, and she was diagnosed with vitamin D deficiency. All other labs were noted to be within normal limits. She was started on high-dose vitamin D at 50,000 IU weekly for 8 weeks, and was referred to a registered dietician for consultation. CT scan of the bilateral lower extremities demonstrated additional smaller lucent defect in the left anterior cortex proximal to the stress fracture noted on x-ray.
The atypical nature of multiple stress fractures and a low vitamin D level were concerning for possible prolonged healing. After extensive discussion with the patient and parents regarding activity level and risks of operative management, they wished to proceed with surgery for a potentially faster return to competitive volleyball in hopes of obtaining collegiate scholarships. She first underwent a transpatellar tendon reamed intramedullary nailing of the more symptomatic left tibia with proximal and distal locking screws. She underwent IM nailing of the contralateral tibia 6 weeks later. She attended physical therapy shortly after the right tibial procedure, focusing on a sport-specific return to play. Three and a half months after surgery, she reported the pain had dramatically improved and was cleared to gradually return to sports. Improvement in radiographic appearance of the linear lucencies was appreciated. At the 1-year post-operative follow-up, the patient had returned to full sports (HSS Pedi-FABS = 23) and reported minimal anterior knee pain with impact-related activities. She transitioned her vitamin D supplements to 1,000 IU QD, and her most recent 25-hydroxy vitamin D level was noted to be normal at 41 ng/mL (Figure 2).