Refusing to bear weight on left leg x2 days
Two year-old girl brought in by mom for refusal to bear weight on left leg for the past 2 days. Mom noticed two “bug bites” on the pt’s left knee with surrounding erythema and swelling three days ago. Two days ago, the patient started refusing to bear weight on her L leg. The following day, the pt was seen by pediatrician who prescribed Keflex with improvement in erythema but she is still refusing to bear weight prompting presentation to the ED. Denies any trauma, fever, vomiting, other rashes, tick bites, similar previous episodes.
PMH / PSH
Vitals: 98.4, HR 121, RR 24, SpO2 100% on RA
General: well-developed, NAD, alert and appropriate
CV: rrr, no m/r/g
Pulm: CTA b/l
Abd: Soft, ntnd
No swelling/ecchymosis/rashes over head/torso/abd/back/legs.
L hip: no skin breaks/erythema/swelling, passive FROM, not TTP, no pain w/ log roll
L knee: 2cm area of erythema over patella with mild swelling, no effusion/warmth, not TTP over patella/joint lines, passive FROM, refused to actively range
L ankle: no skin breaks/erythema/swelling/ecchymosis, no TTP, FROM
SILT SU/SA/SP/DP/T nerves
Unable to bear weight on L leg
No labs drawn.
L hip and knee ultrasound showed no effusions or synovitis.
What is the differential diagnosis for refusal to walk in a toddler?
- Septic arthritis
- Transient synovitis
- Vasculitis, serum sickness
- Fractures, i.e. spiral, buckle, stress
- Non-fractures: Sprains, sprains, contusions
- Always consider child abuse.
- Soft tissue and boney tumors
- Developmental dysplasia of the hip
- Legg–Calvé–Perthes disease
- Intra-abdominal pathology, i.e. appendicitis
- Inguinoscrotal disorders, i.e. testicular torsion
What do the radiographs show?
A non-displaced buckle fracture of the distal left tibial metaphysis is best visualized in Figure 4 with mild overlying soft tissue swelling. No additional fracture is visualized. The hip appears appropriately located.
Torus or “buckle” fractures occur in long bones when axial loads compress and disrupt the trabecular framework. These fractures are often seen in children and commonly involve the distal radius. On radiograph, a “buckle” of the cortex may be evident; however, the only clue may be a subtle angulation of the bone, i.e. note the slight angulation of the medial distal tibia in our patient.
Spiral or “Toddler’s” fractures are distinct from torus fractures. Spiral fractures are most prevalent in patients aged 9 months to 3 years when they are just beginning to ambulate. Even small rotational forces on the tibia, such as during a twisting fall, can cause the bone to fracture in the spiral pattern. The fracture line is often faint and not apparent during the initial evaluation (up to 1/3 of cases). Repeat x-rays, often taken one week after the initial trauma, will reveal sclerosis and peri-steal reaction at the fracture site. Non-malicious spiral fractures in toddlers almost exclusively occur occur along the distal tibial shaft. A spiral fracture found in an upper extremity, proximal tibia, or in non-mobile children should raise concern for child abuse.
What is the management for this patient?
Buckle fractures generally heal well without complications. The patient’s left leg was placed in a non-weight bearing long leg splint with her knee placed in 30 degrees of flexion and her ankle in a neutral position. The cellulitis over her patella was a red herring. Nevertheless, the patient was instructed to complete her antibiotic course.
Proper healing is typically monitored with repeat x-rays, often every 2-4 weeks. Our patient saw an orthopedic surgeon 10 days after her initial presentation; at that time, her splint was removed and she was placed in a walking CAM boot. Her cellulitis had completely resolved. At her 1 month follow-up, she was doing well and walking in her CAM boot without pain. Repeat x-rays showed interval sclerosis with periosteal reaction at the fracture site with proper alignment. The CAM boot was discontinued and she was allowed to resume her normal activity.
- Chapman, J and Cohen, J. Tibial and fibular shaft fractures in children. In: uptodate.com 2015 October, UpToDate, Waltham, MA. (Accessed 30 October 2015).
- Clark, M. Overview of the causes of limp in children. In: uptodate.com 2015 October, UpToDate, Waltham, MA. (Accessed 30 October 2015).
- Souder, C. Tibia shaft fractures – pediatric. In: orthobullets.com 2015 October 11, Lineage Medical, LLC, Cambridge, MA. (Accessed 30 October 2015).