Background: Tarsal navicular bone stress injuries (BSIs) are considered "high risk" because of prolonged healing times and higher rates of nonunion in adult populations but, to our knowledge, have not been comprehensively examined in adolescent athletes.
Purpose: To describe the characteristics of tarsal navicular BSIs in adolescents.
Study design: Case series; Level of evidence, 4.
Methods: A retrospective analysis of patients aged 10 to 19 years with a radiographically diagnosed tarsal navicular BSI was performed at 8 academic centers over a 9-year study period. Age, sex, body mass index (BMI), primary sport, physical examination findings, imaging, treatment, surgical technique, return-to-sport time, and complications were analyzed.
Results: Among 110 patients (mean age, 14.7 ± 2.7 years; 65% female), common primary sports were cross-country/track and field (29/92 [32%]) and gymnastics/dance (25/92 [27%]). Grade 4 BSIs were identified in 44% (48/110) of patients, with fracture lines present on radiography or magnetic resonance imaging. Nonoperative treatment (mean age, 14.4 ± 2.6 years), consisting of protected weightbearing and either a protective boot (69/88 [78%]) or a cast (19/88 [22%]), was trialed in all patients and was successful in 94 patients (85%). Operative treatment (mean age, 17.1 ± 1.4 years) was ultimately pursued for 16 patients (15%). Patients who required surgery had a higher BMI and a higher percentage of fracture lines present on imaging (nonoperative: 36/94 [38%]; operative: 14/16 [88%]). The median time to return to weightbearing, running, and full sport was significantly longer in duration for the operative group than the nonoperative group (P <.05). Complications associated with surgery included 1 case each of delayed union, nonunion, and painful implants, the latter of which required secondary surgery.
Conclusion: Adolescent tarsal navicular BSIs were identified most commonly in female patients in leanness sports. Adolescents who required surgery were more likely to be older, have higher BMIs, and have grade 4 BSIs, and they returned to sport within a median of 5 months after single- or double-screw fixation with a low risk of postoperative complications. A better understanding of the presenting signs and symptoms and appropriate diagnostic imaging of navicular BSIs may lead to an earlier diagnosis and improved outcomes.
Keywords: BSI; adolescent athlete; bone stress injury; overuse injuries.