Case presentation

Case 1

Patient 1 was a 13-year-old boy who sustained a right knee injury while jumping during rugby. He developed acute pain and functional incapacity immediately after the injury. Physical examination showed swelling over the tibial tubercle, patella alta, and inability to raise the leg with the knee extended. He had no relevant comorbidities or antecedent apophysitis. Radiographs and CT 3D reconstruction demonstrated an Ogden type IIB tibial tubercle fracture with complete rotational displacement of the fragment (Figure 1). The lesion consisted of an avulsion fracture of the tibial tubercle with fragment rotation and complete distal patellar tendon avulsion without an attached osseous fragment. He underwent open reduction and internal fixation with 3.5 mm Dart-Fire cannulated screws, and the tendon was repaired with two suture anchors and high-strength sutures using Krackow configuration. Fracture union was achieved by four months (Figure 2), and he returned to rugby by eight months. At final follow-up, 20 months after surgery, he had full active extension, no complications, a Lysholm score of 100, and a Tegner score of 9 both before injury and at final follow-up.

Figure 1: Preoperative lateral radiograph and three-dimensional computed tomography reconstruction of case 1.(A) Lateral radiograph demonstrating an Ogden type IIB tibial tubercle fracture with complete rotational displacement of the fragment. Small osseous fragments within the patellar tendon region (arrow) are consistent with the sign described by Kramer et al. [5] as a clue to associated patellar tendon avulsion. (B) Three-dimensional CT reconstruction confirming complete fragment rotation and the small osseous fragments within the patellar tendon region (arrow).

Figure 2: Postoperative anteroposterior and lateral radiographs of case 1.(A) Anteroposterior and (B) lateral radiographs obtained four months postoperatively, demonstrating maintained reduction, stable fixation, and fracture union following open reduction and internal fixation of the tibial tubercle with concomitant patellar tendon repair.

Case 2

Patient 2 was a 16-year-old boy who sustained a right knee injury during a jumping mechanism while playing sports. He presented with pain and inability to continue activity. On physical examination, the patient presented with knee swelling, inability to perform a straight-leg raise, loss of active knee extension, and a palpable defect over the patellar tendon. He had no comorbidities or antecedent apophysitis. Radiographs demonstrated an Ogden type IB tibial tubercle fracture with complete rotation of the fragment (Figure 3). The injury consisted of a tibial tubercle fracture with fragment rotation and complete distal patellar tendon avulsion. He underwent open reduction and internal fixation of the tibial tubercle, followed by patellar tendon repair with four suture anchors and Krackow sutures (Figure 4). Advanced fracture consolidation was documented by four months, and he returned to sports by seven months. At final follow-up, 27 months after surgery, he had full active extension and no complications. His Lysholm score was 89, and his Tegner score remained 8 before injury and at final follow-up. He returned to the same sport, although he still reported mild residual discomfort.

Figure 3: Preoperative imaging of case 2.(A) Lateral radiograph, (B) sagittal CT image, and (C) three-dimensional CT reconstruction demonstrating an Ogden type IB tibial tubercle fracture with complete rotational displacement of the fragment (arrows), suggestive of an associated patellar tendon avulsion.

Figure 4: Intraoperative photographs of case 2.(A) Exposure of the bifocal extensor mechanism injury following reduction of the tibial tubercle fragment. (B) Patellar tendon repair using suture anchors and Krackow sutures. (C) Final construct after tibial tubercle fixation and patellar tendon repair.

Case 3

Patient 3 was a 17-year-old boy who sustained a left knee injury after a ground-level fall with direct trauma to the knee. He developed pain, swelling, and functional limitation. Physical examination showed ecchymosis and increased volume around the tibial tubercle, and he was unable to activate the extensor mechanism. He had no comorbidities or antecedent apophysitis. Preoperative radiographs demonstrated an Ogden type IIB tibial tubercle fracture without fragment rotation, and magnetic resonance imaging confirmed the associated distal patellar tendon avulsion (Figure 5). The lesion consisted of an avulsion fracture of the tibial tubercle with moderate comminution and complete distal patellar tendon avulsion with an attached 17 mm osseous fragment. He underwent open reduction and internal fixation with one cannulated screw and washer, followed by tendon repair with a suture anchor and high-strength sutures using a Krackow technique. Radiographs obtained at six months postoperatively demonstrated maintained reduction and fracture union (Figure 6). At final follow-up, 14 months after surgery, he had recovered full range of motion, was asymptomatic, and had no functional limitation or complications. His Lysholm score was 99, and his Tegner score improved from 6 before injury to 7 at final follow-up. He had full active extension and reported a higher activity level than before injury.

Figure 5: Preoperative lateral radiograph and sagittal magnetic resonance image of case 3.(A) Lateral radiograph, (B) sagittal T1-weighted MRI, and (C) sagittal fat-suppressed T2-weighted MRI demonstrating an Ogden type IIB tibial tubercle fracture without complete rotational displacement of the fragment. The distal patellar tendon avulsion (arrows) is evident on MRI despite the absence of fragment rotation, demonstrating that this radiographic sign is not universally present in bifocal extensor mechanism injuries.

Figure 6: Postoperative radiographs of case 3.(A) Anteroposterior and (B) lateral radiographs obtained six months postoperatively demonstrating maintained reduction, stable fixation, and fracture union following open reduction and internal fixation of the tibial tubercle with concomitant patellar tendon repair.

A summary of the clinical characteristics, surgical management, and outcomes of the three patients is presented in Table 1.

Variable | Case 1 | Case 2 | Case 3
Age/sex | 13/Male | 16/Male | 17/Male
Injury mechanism | Jumping during rugby | Jumping injury | Fall with direct knee trauma
Ogden classification | IIB | IB | IIB
Key physical findings | Patella alta, inability to perform straight-leg raise | Patella alta, inability to perform straight-leg raise | Swelling/ecchymosis, extensor mechanism deficit
Radiographic clue | Complete fragment rotation | Complete fragment rotation | No fragment rotation
Patellar tendon injury | Complete distal avulsion | Complete distal avulsion | Complete distal avulsion with bony fragment
Surgical treatment | ORIF + suture anchors + Krackow repair | ORIF + suture anchors + Krackow repair | ORIF + suture anchor + Krackow repair
Clinical outcome | Union, returned to sports | Union, returned to sports | Full ROM, asymptomatic
Follow-up | 20 months | 27 months | 14 months