Anterior cruciate ligament (ACL) fractures are rare and occur most frequently at the tibial insertion in skeletally immature patients [1-6]. Femoral-sided avulsion fractures are exceptionally rare, and no consensus exists on management ^[1,6,11] Misinterpretation as tibial eminence fractures on plain radiographs may delay definitive diagnosis, making advanced imaging essential ^[4,6]. Preserving the femoral physis is critical to avoid growth disturbance.

Computed tomography (CT) imaging demonstrated a displaced femoral-sided avulsion fragment without comminutionse. See Fig. 1.

Figure 1: Pre-operative 3D computed tomography reconstruction demonstrating displaced femoral-sided anterior cruciate ligament avulsion fragment.

Intraoperative arthroscopy confirmed intact ACL midsubstance and tibial insertion, supporting primary fixation rather than ligament reconstruction ^[6,7].

Surgical technique

Two loop sutures were placed at the ligament–bone junction. See Fig. 2.

Figure 2: Arthroscopic intraoperative view showing displaced femoral avulsion fragment (red arrow) and suture passage beneath fragment (black arrow).

Two parallel 2.4-mm femoral tunnels were drilled under direct visualization and deliberately positioned distal to the femoral physis to avoid physeal violation. Anatomic reduction was maintained during tensioning to ensure stable bone-to-bone compression at the native ACL footprint.

Figure 3: Six-week post-operative 3D computed tomography reconstruction demonstrating maintained fragment position.

Post-operative outcome

Radiographic evaluation at 6 weeks demonstrated maintained reduction and anatomical restoration. See figure 3. At 6-month follow-up, clinical examination revealed a full symmetric range of motion and stable knee ligaments. No radiographic signs of growth plate disturbance were observed.

Conservative treatment has been associated with persistent instability and inferior outcomes ^[1,8]. Primary fixation in cases with intact ACL substance preserves native ligament biology and proprioceptive function. The principal technical concern is the protection of the femoral physis. Small-diameter tunnels positioned distal to the growth plate minimize theoretical risk of growth disturbance while providing stable fixation ^{[2,6,7,8,9,10]}. Limitations include a single-case design and a limited follow-up duration.

Arthroscopic physeal-sparing fixation can safely restore knee stability and allow bone-to-bone healing in femoral ACL avulsion injuries among skeletally immature patients.

Clinical Message: In skeletally immature patients with femoral-sided ACL avulsion fractures, arthroscopic physeal-sparing fixation provides stable anatomical restoration while minimizing the risk of growth plate injury.