Arthroscopically assisted reduction and internal fixation of a femoral anterior cruciate ligament osteochondral avulsion fracture in a 14-year-old girl via transphyseal inside-out technique

Ronny Langenhan 0 1 2 3 Matthias Baumann 0 1 2 3 Bernd Hohendorff 0 1 2 3 Axel Probst 0 1 2 3 Per Trobisch 0 1 2 3 0 M. Baumann Berufsgenossenschaftliche Unfallklinik, Eberhard-Karls-Universitat Tubingen , Schnarrenbergstr. 95, 72076 Tubingen, Germany 1 R. Langenhan (&) A. Probst Klinik fur Orthopadie, Unfall- und Handchirurgie, Hegau-Bodensee-Klinikum Singen, Virchowstr. 10, 78224 Singen, Germany 2 P. Trobisch Orthopadische Universitatsklinik Magdeburg , Leipziger Str. 44, 39120 Magdeburg, Germany 3 B. Hohendorff Elbe Kliniken Stade Buxtehude, Abteilung fur Hand-, A sthetische und Plastische Chirurgie, Bremervorder Strae 111, 21682 Stade, Germany Femoral avulsion fracture of the anterior cruciate ligament (ACL) in children and adolescents is rare, and its arthroscopic treatment is even more so. A femoral avulsion fracture of the ACL of a 14-year-old girl was arthroscopically reduced and fixed by a Kirschner wire (Kwire) via an inside-out technique. A 1.4-mm K-wire was drilled inside-out into the osseous defect of the lateral femoral condyle under arthroscopic visualization. The avulsed fragment was reduced and then drilled retrograde by the wire. After bending the intra-articular visible end of the K-wire by a knot pusher, the fragment was gently fixed by pulling the wire from outside. At 24 months, both knee stability and range of motion were the same in the operated and the healthy opposite leg. Magnetic resonance imaging evaluation and conventional radiographs showed an intact ACL without detectable disturbance in the growth plate. Only seven cases of a proximal avulsion of the ACL in children and adolescents have been published. Six were treated by open reduction and internal fixation, one by arthroscopic reduction without fixation. - Anterior cruciate ligament (ACL) injuries in children and adolescents are rare, comprising about 0.5 % of all ACL tears [1]. Bone avulsions are more frequent due to weaker epiphyseal insertion compared to strong elastic ligaments [2]. A tibial avulsion of the ACL is the most common form and also the most common osseous lesion in knee injuries of the growing skeleton [3]. In contrast, femoral osteochondral avulsion fracture of the ACL in children is a rarity. To our knowledge, only seven cases have been reported so far [28]. We present a 14-year-old girl with a femoral osteochondral avulsion fracture of the ACL, which was arthroscopically reduced and fixed by a Kirschner wire (K-wire) via an inside-out technique. Patient and methods A 14-year-old girl suffered a distortion of her left knee during school sports. At initial investigation, passive Fig. 1 Anteroposterior (a) and lateral (b) view of the left knee with a femoral osteochondral avulsion fracture of the ACL (black arrow) Fig. 2 Arthroscopic visualization of the 1.4-mm K-wire (a), drilled inside-out into the center of the osseous defect of the lateral femoral condyle. Schematic of surgical technique (b) motion of the knee was restricted due to pain and swelling (extension/flexion, 0/20/70 ). The Lachman and pivot shift tests were positive. Evaluation of conventional radiographs (Fig. 1) and magnetic resonance imaging (MRI) showed a femoral osteochondral avulsion fracture of the ACL without injury of other structures. An arthroscopic reduction and internal fixation was performed. A 1.4-mm K-wire was drilled inside-out into the center of the osseous defect of the lateral femoral condyle under arthroscopic visualization (Fig. 2). The avulsed fragment was reduced anatomically and then drilled retrograde by the K-wire, while the knee was positioned in 20 of flexion. After bending the visible intra-articular end of the K-wire by a knot pusher, the fragment was gently fixed by pulling the wire from outside. Figure 3 shows the instruments and bending technique of the K-wire. The proximal end of the K-wire was cut under the fascia of the M. vastus lateralis (Fig. 4). After operation, the knee was immobilized in a brace in 20 of flexion for 6 weeks. Three months postoperatively, the K-wire was removed by pulling it gently from the proximal end. The bent intra-articular part of the wire straightened upon pulling, and the whole wire was removed without any complication. An elective diagnostic arthroscopy confirmed a stable ACL. Upon follow-up at 24 months, clinical examination revealed no effusion and no passive motion deficit (extension/flexion, 5/0/150 , comparable to the opposite healthy leg). The knee ligaments were stable (negative Lachman, reverse pivot shift, and pivot shift tests). Neither patellofemoral nor medial or lateral compartment crepitation was detectable. The girl performed a one-leg hop three times for both legs without limitation. She also had no limitations in sports activities. Both MRI evaluation and conventional radiographs showed an intact ACL without detectable disturbance in the growth plate of the distal femur (Fig. 5). Grade A was noted using the IKDC Knee Examination Form [9]. To our kn (...truncated)