Case 1 (Fig. 3 )
Soft tissue infection - Buttock Abscess
2 year old,
non weight bearing on left leg. Recent chickenpox infection became increasingly irritable and febrile.
Reluctant with both active and passive leg movements.
CRP 209 (<5),
wbc 30.1 (4-11)
Fig. 3: Case 1
(A)XR – soft tissue swelling left gluteal region
US – No hip joint effusion.
MRI – (B) Coronal STIR , (C) Coronal T1 + gad, (D) Axial T1FS + gad
Left gluteal abscess with oedema in adjacent muscles and soft tissues. No bone, lower spine, SIJ or hip joint involvement.
Diagnosis - Left gluteal abscess with oedema in adjacent muscles and soft tissues.
No bone,
lower spine,
SIJ or hip joint involvement.
Open surgical drainage.
Growth of Beta-Haemolytic Streptococcus.
Treated with Flucloxacillin and Clindamycin.
Case 2 (Fig. 4)
Septic Arthritis
5 year old limping after a fall,
swollen,
painful right knee,
fever.
Wbc 12.3 CRP 44.
Radiograph – Nothing Abnormal Detected.
US - effusion and aspiration.
MRI - to exclude associated osteomyelitis.
Fig. 4: Case 2
MRI – (A) cor STIR (B) ax T2 (C-D) sag and ax T1FS+gad;moderate synovial thickening and an effusion, no associated osteomyelitis.
Diagnosis – septic arthritis.
Knee aspirate & blood cultures - Beta-Haemolytic Streptococcus (A) & Gram +ve cocci
Underwent arthroscopic washout (x2).
Received 3/12 antibiotics.
Case 3 (Fig. 5)
Brodies Abscess with Soft Tissue Extension
14 year old; painful swollen right knee for 3/52 on 1 year background.
Febrile/night sweats with rigors.
Fixed flexion deformity
Pyrexial,
Wbc 18.6 CRP 184
Aspiration from knee effusion sterile.
Fig. 5: XR (A) – Brodie’s abscess - well defined distal femoral metaphyseal lucency abutting growth plate. Soft tissue swelling posterior to knee.
MRI – (B-D) Intraosseous Brodie’s abscess with extension through growth plate into epiphysis. Breach in posterior cortex extending into large, loculated soft tissue abscess in postero-medial distal thigh. Reactive synovitis/joint effusion,
Diagnosis – Brodies abscess with posterior cloaca and extra-articular soft tissue abscess.
Blood cultures negative.
Underwent incision and drainage of distal femur – grew staph aureus.
Had 8/52 post-op flucloxacillin.
Case 4 ( Fig. 6)
Sacro-ileitis
2 year old presented with high fever,
irritability,
anorexia.
CRP 147,
wbc 23,
LP and BC normal.
Given meningococcal prophylaxis.
Abdominal and hip US normal.
On ward began to refuse to weight bear and pain on sitting.
Fig. 6: MTWS Sag STIR- normal apart from high signal inflammation around left SIJ
MRI pelvis cor & ax STIR - Fluid within the L SIJ with adjacent bone marrow oedema and soft tissue inflammation.
Diagnosis - Sacroileitis - Fluid within left sacroiliac joint with adjacent bone marrow oedema and surrounding soft tissue inflammation.
No pathogen identified.
Treated with 2/52 IV Ceftriaxone and 2/52 oral Co-Amoxiclav.
Case 5 (Fig. 7)
Talar Osteomyelitis
18month old.
1/12 limping & apparent pain in right foot
Afebrile.
Normal WBC & CRP.
Fig. 7: XR (A) – bony erosion lateral talus
USS - fluctuance at posteromedial subtalar joint
MRI – (B) coronal STIR (C) axial T2 (D) axial STIR; oedema throughout talus with more fluid component lateral aspect. Generalised post-contrast enhancement.
Diagnosis – osteomyelitis.
Blood cultures negative
Treated with IV ceftriaxone then PO cefalexin
Case 6 (Fig. 8)
Discitis
3 year old presented with low back/buttock pain and reluctance to walk
ESR 76 (1-15),
CRP 15,
wbc normal,
negative blood cultures.
XR – normal
Fig. 8: MRI (A) sag T1, (B) sag T1 + gad, (C) sag STIR, (E) axial T1, (F) ax T1 + gad L4/5 discitis. Pocket of fluid in disc space extending into adjacent vertebral bodies. Oedematous bone marrow. Small extradural collection. Avid enhancement after contrast.
Diagnosis - discitis.
No pathogen identified.
Improved with 6/52 Flucloxacillin.
Case 7 (Fig. 9)
Septic Arthritis/Osteomyelitis
13 year old presented with painful,
swollen left knee.
Joint effusion on XR.
Aspirate grew staph aureus,
started on flucloxacillin.
Remained pyrexial and symptoms worsened.
Raised inflammatory markers.
MRI - confirmed bone,
joint and soft tissue involvement.
Fig. 9: MRI (A) Sag T1, (B) ax T2, (C) Cor T2, (D) Cor T1FS + gad. Enhancing sepiginous cavities in distal femur with posteromedial subperiosteal abscess . Large soft tissue abscess and joint effusion/synovitis.
References: Scarborough Hospital, York Hospitals, UK
Diagnosis - septic athritis and osteomyelitis with intra-osseous and soft tissue abscesses.
Multiple washouts and open debridements.
Several courses of intravenous and oral antibiotics.
Differential Diagnoses to consider:
Developmental Dysplasia of the Hip (Fig. 10)
Perthes (Fig. 11)
Transient Synovitis (Fig. 12)
Slipped Upper Femoral Epiphysis (Fig. 13)
Case A (Fig. 14)
Osteoid osteoma
3 year old presented with painful limp. CRP,
wbc normal.
Aypyrexial.
Fig. 14: (A) US – left hip effusion. Initially treated as transient synovitis but symptoms continued. (B) GA MRI with US guided aspiration – sterile effusion. Coronal STIR shows left hip effusion and diffuse femoral neck oedema. Some medial cortical thickening so (C) multiplanar CT obtained which confirmed osteoid osteoma (arrow), later readmitted for (D) ablation therapy by CT guided thermocoagulation,
Case B (Fig. 15)
Chronic Relapsing Multifocal Osteomyelitis
10 year old boy presented with left hip pain and limp.
Mildly raised inflammatory markers.
Fig. 15: (A)2008 Normal FLL XR for left hip pain(B)MRI cor STIR in 2009 3/12 left hip pain , abnormal oedematous marrow signal in roof of left acetabulum, right greater trochanter and both ischia. Opinion and biopsy from Birmingham Bone Tumour Unit. Diagnosed CRMO. ESR 16, CRP 21. No pathogen. Treated with non steroidals and occasional antibiotics.(C)2011 cortical thickening and sclerosis right subtrochanteric region.
(D)2013 thickening and sclerosis medial 2/3 right clavicle, typical for CRMO
Case C (Fig. 16)
Idiopathic Chondrolysis
14 year old girl presented with an acutely painful,
stiff left hip and limp.
Rapidly developed a flexion deformity.
Inflammatory markers and wbc normal.
Fig. 16: Idiopathic chondrolysis
XR 2013 - joint space narrowing and flexion deformity. US - Left hip joint effusion, aspirated and found to be sterile. MRI - Left hip joint effusion and synovitis with widespread cartilage loss. Bone marrow oedema in the femur and acetabulum, with characteristic band of high signal in the central weight bearing portion of the epiphysis. Diagnosed as idiopathic chondrolysis. XR at 1year follow up showed no significant improvement in degree of cartilage loss.