1. Tumors About the Knee Misdiagnosed as Athletic Injuries by D. Luis Muscolo, Miguel A. Ayerza, Arturo Makino, Matías Costa-Paz, and Luis A. Aponte-Tinao J Bone Joint Surg Am Volume 85(7):1209-1214 July 1, 2003 ©2003 by The Journal of Bone and Joint Surgery, Inc.

2. Figs. 1-A and 1-B Case 12, a forty-three-year-old male soccer player who was finally diagnosed with an osteosarcoma after having been initially treated as if he had an athletic injury. D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.

3. Fig. 1-B Sagittal magnetic resonance image, made at the time of admission to our institution, shows an osteosarcoma of the distal part of the femur with cortical destruction and soft-tissue extension (arrow). D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.

4. Figs. 2-A, 2-B, and 2-C Case 15, a sixteen-year-old girl who had had knee pain for six months and was treated for that period of time as if she had a meniscal lesion. D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.

5. After several weeks of physical therapy, an arthrogram was performed. D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.

6. Lateral radiograph made at the time of admission to our institution, showing a tumor mass with gross periosteal reaction (arrows). D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.

7. Case 23, a forty-year-old woman with knee pain who had poor-quality initial radiographs and underwent a diagnostic arthroscopy at another institution. D. Luis Muscolo et al. J Bone Joint Surg Am 2003;85:1209- 1214 ©2003 by The Journal of Bone and Joint Surgery, Inc.