Module 25, General Orthopaedist Level

This 9 year old female presented to the emergency room with a four day history of mild right knee pain. She limps on the affected extremity when ambulating but has minimal to no pain at rest. No history of trauma was reported. She has had mildly elevated temperatures over the past several days according to the mother. There is no history of joint stiffness or chronic fatigue. No other joints are involved. There is no history of tic exposure. She has been otherwise healthy in the past. On physical examination of the right knee there is no limitation in flexion or extension. There is mild diffuse tenderness that is poorly localized over the medial femoral condyle. There is no soft tissue swelling or joint effusion noted. No pain is elicited with ROM of the knee. The remaining extremities are without tenderness or swelling. Temperature is 38.8* C. LABS: WBC 13,400 Differential-- 73% polys, 8% lymphs, 1% bands, Sed rate 41 mm/hr. The patient was discharged home and re-checked the following day persistent tenderness over the knee and new physical findings of swelling and pain with decreased Range Of Motion of the knee, temperature was 39.2. She says she feels no different than yesterday.

Question 25A

Further work up now should include a bone scan.

Question 25B

The child should now be admitted to hospital and started on IV Dicloxacillin.

Question 25C

An ultrasound of this painful knee will provide useful information.

Question 25D

The best test to evaluate the possibility of a small lesion in the epiphysis which you think may be seen on x-ray is by MRI.

Question 25E

The knee is aspirated and the fluid has a WBC count of 27,000. You can reassure the parents that there is no bacterial infection and start the child on doxicycline.