case_images: PMC11735375_01
case_images: Radiographs of right (R) knee showing eccentric juxta-articular osteolytic lesion in proximal tibial: Anteroposterior (A) and lateral (B) views.
case_images: OS-17-295-g011.jpg
case_images: PMC11735375_01_OS-17-295-g011.jpg
case_images: os14287-fig-0001
case_images: Radiographs revealed a well-defined radiolucent lesion with sclerotic margins in the tibia intercondylar eminence of the right knee (Figure 1). T2-weighted image. The presence of adjacent marrow edema is evident, while no involvement is detected in the tibial epiphyseal region (Figure 3). The patient underwent 18F-FDG PET/CT imaging at our hospital, the SUVmax = 8.1, suggesting a primary bone tumor (Figure A1).
case_images: CT scans and three-dimensional reconstruction showing osteolytic lesion in proximal tibial physis of right knee: axial view (A); sagittal view (B); coronal view (C); and three-dimensional reconstruction of the lesion (D).
case_images: OS-17-295-g009.jpg
case_images: PMC11735375_01_OS-17-295-g009.jpg
case_images: os14287-fig-0002
case_images: Subsequent computed tomography (CT) scans and three-dimensional film revealed an eccentric osteolytic lesion located posterior to the tibial intercondylar eminence, exhibiting a well-defined lucency and marginal sclerosis (Figure 2). These findings confirm the diagnosis of chondroblastoma (Figure A2).
case_images: Magnetic resonance images of proximal tibial lesion in right knee: coronal T1-weighted image (A), coronal T2-weighted image view (B), sagittal T1-weighted image (C), and sagittal T2-weighted image (D). A well-circumscribed septate lesion is seen, consisting of lobules with evidence of neighboring marrow edema.
case_images: OS-17-295-g010.jpg
case_images: PMC11735375_01_OS-17-295-g010.jpg
case_images: os14287-fig-0003
case_images: T2-weighted image. The presence of adjacent marrow edema is evident, while no involvement is detected in the tibial epiphyseal region (Figure 3). The patient underwent 18F-FDG PET/CT imaging at our hospital, the SUVmax = 8.1, suggesting a primary bone tumor (Figure A1). During the one-month postoperative follow-up, the radiographs showed no evidence of recurrence (Figure A3) and the Lysholm score of the right knee was 67 (Figure A4).
case_images: Arthroscopic procedures under direct vision: a vascular traction band is utilized to pull the anterior cruciate ligament (A, B); and the location of the lesion in knee (C), the red arrow represents the anterior cruciate ligament, the blue arrow represents the posterior cruciate ligament. The red circle indicates the location of the lesion; the lesion was exposed after soft tissues were cleaned (D).
case_images: OS-17-295-g001.jpg
case_images: PMC11735375_01_OS-17-295-g001.jpg
case_images: os14287-fig-0004
case_images: The lesion was partly concealed by the anterior cruciate ligament and a vascular traction band is utilized to pull the anterior cruciate ligament and thereby expose the lesion (Figure 4A,B). After synovium was resected, the location of the lesion was confirmed by probing the hyperemic area with a finger pin that pierced through the thinned out cortex forming the roof of the lesion (Figure 4D). After debriding the surrounding soft tissue, the lesion was de-roofed using a shaver and curette (Figure 5A). During the one-month postoperative follow-up, the radiographs showed no evidence of recurrence (Figure A3) and the Lysholm score of the right knee was 67 (Figure A4).
case_images: Arthroscopic procedures under direct vision: confirmed by probing the lesion area (A), thinned out cortex forming the roof of the lesion (B), complete debridement of tumor tissue is performed and healthy cancellous subchondral bone is reached (C) and graft bone was fitted into the defect and stabilized Kirschner wires (D).
case_images: OS-17-295-g003.jpg
case_images: PMC11735375_01_OS-17-295-g003.jpg
case_images: os14287-fig-0005
case_images: After synovium was resected, the location of the lesion was confirmed by probing the hyperemic area with a finger pin that pierced through the thinned out cortex forming the roof of the lesion (Figure 4D). After debriding the surrounding soft tissue, the lesion was de-roofed using a shaver and curette (Figure 5A). Under direct vision, a lesion sharply separated from the adjacent bone and contains a mixture of soft, friable, gray material and hemorrhage was observed (Figure 5B). The remnants of the lesion were excised with a shaver under and the periphery was debrided under the arthroscopy until healthy cancellous bone became visible (Figure 5C). Finally, the graft bone was fitted into the defect and stabilized Kirschner wires and absorbable screw (Figure 5D).
case_images: A shaver with a 90  bent angle was employed in surgery (C). A straight shaver cannot reach the anterior wall of the lesion (A). A shaver with a 90  bent angle can reach the anterior wall of the lesion (B).
case_images: OS-17-295-g008.jpg
case_images: PMC11735375_01_OS-17-295-g008.jpg
case_images: os14287-fig-0006
case_images: The curettage of the anterior aspect of the lesion presents challenges due to its location; therefore, a shaver with a 90  bent angle was employed (Figure 6).
case_images: Radiographs of right knee showing a good osteointegration of the bone graft 3 months after surgery: anteroposterior (A) and lateral (B) views.
case_images: OS-17-295-g006.jpg
case_images: PMC11735375_01_OS-17-295-g006.jpg
case_images: os14287-fig-0007
case_images: Three months after surgery, the patient was able to walk while weight-bearing, the radiographs showed a good bone fusion (Figure 7) and the Lysholm score of the right knee was 87 (Figure 8).
case_images: The 3-months follow-up after surgery demonstrated an excellent functionality of the knee joint: anterior (A) and lateral (B) view.
case_images: OS-17-295-g014.jpg
case_images: PMC11735375_01_OS-17-295-g014.jpg
case_images: os14287-fig-0008
case_images: Three months after surgery, the patient was able to walk while weight-bearing, the radiographs showed a good bone fusion (Figure 7) and the Lysholm score of the right knee was 87 (Figure 8).
case_images: CT scan showing at 12 months of follow-up of a good osteointegration of the bone graft: axial view (A), sagittal view (B), and coronal view (C).
case_images: OS-17-295-g015.jpg
case_images: PMC11735375_01_OS-17-295-g015.jpg
case_images: os14287-fig-0009
case_images: At 12 months post-surgery, CT scans revealed good fusion of the bone graft without any evidence of recurrence (Figure 9).
case_images: The 12-months follow-up after surgery demonstrated an excellent functionality of the right knee: flexed position of right knee (A) and Crouch of the patient (B).
case_images: OS-17-295-g004.jpg
case_images: PMC11735375_01_OS-17-295-g004.jpg
case_images: os14287-fig-0010
case_images: The right knee joint can flex up to 130 , returning to the normal level of flexibility. (Lysholm score = 100, Figure 10).