1983-1984

1. 1983-1984 • Carlos Pineda • Roger Kerr

2. Roger Kerr, Los Angeles, CA • 49 year old male with 6 month history of wrist pain and swelling. • Past medical history is negative. • PE: exquisite tenderness over distal ulna with loss of extension of 4th and 5th fingers. • Routine laboratory studies are negative.

3. 49 year old male with 6 month history of wrist pain and swelling. PA view of wrist: Enlargement of ulnar styloid with lytic/erosive change and soft tissue swelling.

4. 49 year old male with 6 month history of wrist pain and swelling. Coronal T1-weighted image: intermediate signal intensity mass surrounds and engulfs ECU tendon with erosion of distal ulna.

5. 49 year old male with 6 month history of wrist pain and swelling. Sagittal T1-weighted image: intermediate signal intensity mass surrounds and infiltrates ECU tendon.

6. 49 year old male with 6 month history of wrist pain and swelling. Consecutive axial T1-weighted images at level of ulnar styloid: ECU tendon is replaced by predominantly intermediate signal intensity mass that erodes distal ulna.

7. 49 year old male with 6 month history of wrist pain and swelling. Axial T1-weighted and axial T2-weighted images, respectively, at level of tip of ulnar styloid: mass of predominantly intermediate signal intensity has replaced ECU tendon and erodes ulna.

8. 49 year old male with 6 month history of wrist pain and swelling. • Bone scan revealed increased uptake of radionuclide at both 1st MTP joints, ankles and knees and at left midfoot and left shoulder.

9. Differential diagnosis • Tophaceous gout • Tendon sheath lesions: giant cell tumor, fibroma , xanthoma • Tuberculous tenosynovitis • Rheumatoid arthritis with fibrous pannus • Amyloidosis • Clear cell sarcoma

10. Dx: Tophaceous gout of tendon • At surgery ECU and EDC (4th,5th) tendons were debrided of chalky material and crystalline deposits. • Histology: crystals with strong negative birefringence, dense fibrous connective tissue and mild chronic synovitis.

11. Dx: Tophaceous gout of tendon • Gout of tendon: usually in patient with established diagnosis of gout. Tendon infiltration, tenosynovitis, tendon rupture, entrapment neuropathy. Often mis-diagnosed clinically as tumor or tumor-like lesion. • Gout: usually heterogeneous intermediate to low signal intensity on T2-weighted images related to fibrous tissue and urate crystals. Intense gadolinium enhancement.

12. Roger Kerr, Los Angeles, CA • 5 year old male presents with a 2 day history of pain and swelling of left knee. • Vague history of knee pain 4 weeks ago treated with NSAIDS. • No history of trauma or recent infection. • No other joint problems. • WBC=9.4; ESR=44; Febrile (up to 102)

13. 5 year old male presents with a 2 day history of pain and swelling of left knee. Lateral radiograph of the knee

14. 5 year old male presents with a 2 day history of pain and swelling of left knee. AP radiograph of the knee

15. 5 year old male presents with a 2 day history of pain and swelling of left knee. A B Immediate (A) and delayed (B) 99mTcMDP images were interpreted as consistent with septic arthritis with no evidence of osteomyelitis.

16. 5 year old male presents with a 2 day history of pain and swelling of left knee. • Joint aspiration yielded cloudy fluid with 80,000 WBC/mm3 (99% PMNs) and 100,000 RBC/mm3. • Arthroscopic drainage and debridement of the joint was performed on the third hospital day. • Patient was treated with IV antibiotic (Ceftazidine, then Vancomycin) but knee swelling and pain and fever persisted. On day 10, an MRI was obtained.

17. 5 year old male presents with a 2 day history of pain and swelling of left knee. A sagittal T2-weighted image reveals a large joint effusion, synovial hypertrophy, intra-articular debris and a large high signal intensity lesion of the patella c/w septic arthritis and osteomyelitis/bone abscess.

18. 5 year old male presents with a 2 day history of pain and swelling of left knee. B B A Successive axial intermediate-weighted images reveal extension of this lesion through the anterior cortex of the patella. C

19. Diagnosis: septic arthritis of the knee and osteomyelitis/bone abscess of the patella • Incision anddrainage of the patella was performed and purulent fluid was removed. • Histology revealed acute and chronic inflammation and Staph aureus was cultured. • The patient recovered following a course of IV, followed by oral, antibiotics.

20. Osteomyelitis of the patella • Rare – usually due to direct implantation from a break in the skin, puncture wound, septic bursitis or septic arthritis. • Hematogenous spread to patella is exceedingly rare; rich blood supply and no physeal plate with its sluggish hemodynamics. • Acute or insidious onset. • Local signs or symptoms vs. systemic illness. • Diagnosis is often delayed or overlooked as clinician assumes patient only has joint, bursal or soft tissue infection.

21. Osteomyelitis of the patella • Clue to diagnosis: pt. not responding to standard management of septic arthritis. • Surgical debridement indicted for subperiosteal/bone abscess or chronic osteomyelitis. • In this patient, radiographs and bone scan were negative for osteomyelitis due to immaturity of patellar development. MRI was definitive. • Roy DR et al: Osteomyelitis of the patella in children. J Ped Orthop 1991;11:364-366.