A 13-year-old girl had noticed pain for six months when she ran, but no pain while she walked. She also noticed snapping at the medial site of the proximal leg on knee flexion. Her height and body weight were 150cm and 42kg, respectively. She had no past medical history related to the lesion. On physical examination, a small hard lesion was palpable. Tenderness at the medial side of the proximal tibia was observed. The snapping phenomenon was reproduced on knee flexion. Plain radiographs showed a small 0.5 cm osseous lesion on the antero-posterior radiographic view (Fig. ). CT depicted a small protuberant bone lesion with continuity to normal bone (Fig. ). Surgically, the lesions were approached posterior to the conjoint tendon, and resected with a curved chisel while retracting the attachment of the pes anserinus. The lesion was composed of a hyaline cartilaginous cap and underlying lamellar bone trabeculae and fatty marrow (Fig. ). There was no evidence of malignancy. Six months after the surgery, the symptoms had disappeared.
The third child was a 12-year-old male presenting to the outpatient department with complaints of swelling located in the medial aspect of right knee for the last three months. The swelling was insidious in onset without any history of trauma or fever. It was of the size of a lemon, as described by the patient’s guardian. There was associated vague pain in the same area, without any aggravating factor. There was no history of rapid increase in the size of swelling or the intensity of pain. Similar to the other two cases, there was no other swelling or pain elsewhere in the body. On examination, it was found that there was a bony hard, spherical, nodular, tender swelling on the medial aspect of right proximal tibia measuring 3 x 3 cm in size. The overlying skin was normal. Range of motion of knee joint was comparable to the other side. Plain radiograph of the right knee showed the presence of a bony outgrowth from the medial aspect of right proximal tibial metaphysis suggestive of an osteochondroma (Figure ). There was no evidence of malignant transformation on the plain radiograph. The patient was advised rest from exertional activities along with analgesic medications for three weeks causing reduction in pain. However, soon the pain started again gradually over a few days, for which the patient was injected with injection hydrocortisone and 2% xylocaine at the most tender point in the pes anserinus area. After this intervention, the patient became pain-free. The patient was regularly followed-up to check malignant transformation of the swelling. At the last follow-up of one-and-a-half years, there was no increase in the size of swelling or recurrence of pain.