Cartilaginous tibial eminence fractures in children: which recommendations for management of this new entity?

PURPOSE: Cartilaginous tibial eminence fracture (CTEF) is a new pattern of ACL rupture in children under the age of nine. MRI signs have been recently reported, but no series gave information about outcomes. It was hypothesized that primary treatment gave better results than delayed management due to frequent misdiagnosis. METHOD: This retrospective study focused on 15 patients, managed acutely (n = 7) or delayed (n = 8). The patients' median age at the time of initial injury was 6.5 years (range 5-9). Lysholm, IKDC 2000 subjective scores, and the measurement of the residual laxity by a side-to-side difference with a KT-1000 junior arthrometer were used at the time of revision. RESULTS: After a mean follow-up of 9.8 years (range 1-18.5), the mean Lysholm and IKDC subjective scores were, respectively, 97.7 ± 2.6 and 97 ± 3.4. The median residual laxity was 2 mm (range 0-4). Non-operative treatment lead to 2 failures: intermeniscal ligament entrapment and combined avulsion fracture at the femoral site. Suture fixation of the avulsed fragment allows regularly good results when performed acutely or even 4 years after the injury. The hypothesis that primary treatment gives better result than delayed treatment tends to be wrong as 2 failures were reported in each group. An ACL reconstruction was performed in 3 out of the 4 treatment failures. Progressive resorption of the avulsed fragment was noticed in 3 of the 4 failures suggesting an associated ACL resorption. CONCLUSION: CTEF has a good prognosis even after misdiagnosis and treatment at the time of non-union; this could be due to low-energy mechanism of injury and low rate of associated lesion. Orthopaedic treatment for acute minimally displaced fractures is only indicated under strict MRI control, and suture fixation is the recommended strategy in other situations. Conservative management of non-union could expose to ACL involution and cannot be recommended. LEVEL OF EVIDENCE: Retrospective case series, Level IV.