Childhood Limp
Red Flags — the limping child you cannot miss
| Red flag | Why dangerous | Action |
|---|---|---|
| Septic arthritis / osteomyelitis — won't weight-bear/move joint, fever, systemically unwell | Joint destruction within days; sepsis; an emergency at any age. | Same-day paediatric/orthopaedic admission; aspiration + IV antibiotics (Kocher to support) |
| SUFE — overweight adolescent, hip/thigh/knee pain, externally rotated leg, ↓ internal rotation | Delay causes avascular necrosis and permanent damage; can be bilateral. Acute limp over 9 with painful/restricted hip movement → urgent same-day assessment; hip X-ray AP pelvis + frog-lateral of both hips, or cross-table lateral if an unstable slip is suspected (Am Fam Physician 2017 SCFE review, international). | Same-day orthopaedics · non-weight-bearing |
| 🟣 Leukaemia — persistent bone pain/limp + pallor, bruising/petechiae, hepatosplenomegaly, lymphadenopathy, fever, night pain | Haematological malignancy presenting as bone/joint pain. NICE NG12: any one feature (bone pain alone counts) → very urgent FBC within 48 h; unexplained petechiae or hepatosplenomegaly → immediate specialist assessment; unexplained bone pain/swelling → consider very urgent X-ray within 48 h (bone sarcoma). | Very urgent FBC ≤48 h · NG12 |
| Non-accidental injury — inconsistent/changing history, other injuries, non-mobile child with fracture | Child protection. | Safeguarding assessment per local child-protection pathway |
| Perthes' / DDH — insidious limp, restricted hip movement (Perthes' 3–10y); infant asymmetry/limited abduction (DDH) | Femoral head/hip joint damage if missed. | Orthopaedic referral; hip X-ray/USS |
| Atraumatic limp under 3 / unable to localise | Young children localise poorly; serious causes (septic, NAI, malignancy) easily missed. Transient synovitis is rare under 3 and septic arthritis more common. | Same-day paediatric assessment |
🦵 "It's just his knee"
Explain why the hip matters, without dismissing.
"You're right that the pain's in his knee — but in growing children the hip often sends its pain to the knee, so checking the hip is exactly how we avoid missing something important."🏥 Reframing to urgent care
If SUFE, explain the change of plan calmly.
"From examining his hip, I'm concerned about a condition where the top of the thigh bone slips. It needs the hospital to see him urgently today, and he shouldn't put weight on that leg in the meantime — treating it quickly protects the hip."🚫 Not physiotherapy
Explain why physio would be wrong here.
"I know you were hoping for physio, but if this is what I think, exercises could make it worse — this needs an orthopaedic surgeon, not physiotherapy, and quickly."🛡️ Honest reassurance
Balance seriousness with calm.
"This is treatable, and we've caught it at the right time by checking properly. I'll arrange everything now and explain each step so you know what's happening."- Examining only the knee; missing SUFE / not examining the hip
- Not screening for septic arthritis (weight-bearing/fever) or leukaemia red flags
- Referring to physiotherapy / reassuring as a knee problem
- Not considering safeguarding / age-based differential
Same day / 48 h
Don't delay- Septic arthritis / osteomyelitisWon't weight-bear + fever/unwell → admit
- SUFE (suspected)Same-day orthopaedics; non-weight-bearing until seen (Kyle)
- Acute limp under 3Same-day paediatric assessment
- 🟣 Suspected leukaemiaAny NG12 feature → very urgent FBC (48 h); petechiae/HSM → immediate
- Safeguarding / NAIChild-protection pathway
Orthopaedics
Days- JIA (suspected)Paediatric rheumatology — seen within 4 weeks of referral (BSPAR)
- Perthes'Orthopaedic referral; X-ray
- DDH (infant)Hip USS/X-ray; orthopaedics
Primary care
After exclusion- Transient synovitisWell child; rest/analgesia; safety-net; review
- Minor trauma/soft-tissueConservative; review
- Growing pains (exclusion)Reassure if classic & normal exam
- Routing SUFE to physiotherapy/routine care
- Missing septic arthritis or leukaemia red flags
- Examining only the knee; not testing hip internal rotation
- No systemic exam for leukaemia/safeguarding signs
- Forgetting the frog-lateral view for SUFE
- Not arranging urgent FBC when leukaemia features are present
- Waiting for tests instead of admitting suspected septic arthritis
🚩 The one rule that saves the case
Examine the hip in a child with knee pain. Kyle's formulation is SUFE — an overweight 13-year-old with knee/thigh pain, an externally rotated leg, restricted hip internal rotation and a normal knee — needing urgent orthopaedic referral and non-weight-bearing to prevent avascular necrosis, NOT physiotherapy. The same discipline (reason by age, screen the emergencies, examine the joint above) catches the septic hip, Perthes', DDH and the leukaemia/safeguarding red flags.
- Diagnosing a knee problem; missing SUFE
- Calling it transient synovitis/growing pains without exclusion
- Referring SUFE to physiotherapy/routine
- Not admitting septic arthritis / not escalating leukaemia features
Validate — name the expectation and the reasoning behind it
Her request is reasonable on the information she has: the pain is in the knee, Kyle is sporty-ish, and physiotherapy is what friends were offered for knee pain. She is frustrated that it has dragged on for weeks. Acknowledging the frustration and her logic before changing the plan stops the change from feeling like a dismissal — and it gives Kyle permission to hear the explanation without feeling blamed for his weight or for "making a fuss".
"You came in hoping for physio for his knee, and I can completely see why — that's where he feels it, and it's been going on for weeks now. I'm glad you brought him, because I've found something important that changes what we need to do."Explain — the hip sends pain to the knee, and the growth plate has slipped
Use one clear picture: the ball at the top of the thigh bone sits on a growth plate, like a scoop of ice cream on a cone, and in some teenagers during a growth spurt the ball starts to slide off. The nerves that supply the hip also supply the skin around the knee, so the brain reads it as knee pain. The knee exam is normal; the hip exam is not — his hip will not turn inwards and his leg rolls out. Explain why physiotherapy is wrong: exercise and weight-bearing load the slipping growth plate. Explain why speed matters: a slip that becomes unstable risks cutting off the blood supply to the ball of the hip (avascular necrosis), which is permanent.
"When I examined his knee, it was completely normal. But when I turned his hip inwards it was stiff and sore, and his leg rolls outwards. That pattern makes me think the growth plate at the top of his thigh bone has slipped — it's called a slipped upper femoral epiphysis. Hip problems often show up as knee pain, which is why it's been so confusing."Negotiate — offer a concrete, practical plan today
The non-negotiables are same-day orthopaedic assessment and no weight on the right leg until he is seen. What is negotiable is how you make that happen: you phone the on-call orthopaedic team, write the referral letter, advise on how he travels (carried or by wheelchair to the car, crutches only if he is already confident and told not to put the foot down), and you help with the school and work fallout. Offer analgesia now. Tell her what to expect at hospital — X-rays, likely admission and an operation to hold the hip with a screw, usually soon after diagnosis.
"Here's what I'd like to do: I'll ring the orthopaedic team at the hospital now so they're expecting him today. Until they've seen him he mustn't put any weight on that right leg — not even to hop to the car if you can avoid it. I'll give him something for the pain and a letter to take. Does that feel doable, and what would make getting there today easier?"In SUFE the femoral head slips posteriorly and medially on the weakened proximal femoral physis. Loading through the leg drives further slip; a stable slip that becomes unstable (the child cannot bear weight even with crutches) carries a much higher risk of avascular necrosis because the retinacular vessels supplying the head can be torn or kinked.
From the consulting room: wheelchair to the car if available, no hopping or walking "just to the door". Crutches only if he can already use them safely with the right foot off the ground. Hospitals will usually admit and fix promptly. Do not send him for a routine outpatient X-ray and home to wait.
Transient synovitis is a self-limiting, usually post-viral, sterile inflammation of the hip synovium with a small effusion. Rest reduces intra-articular pressure and pain; anti-inflammatory analgesia may shorten symptoms. The natural history is improvement over days — which is exactly why failure to improve is itself a red flag.
Let the child choose their level of activity; avoid sport and trampolining until walking normally. Keep them off nursery or school only while they cannot walk comfortably. Give a written sheet with the return criteria and the 48-hour review time. If not fully resolved by around a week, or it recurs, reassess and consider imaging for Perthes'.
Perthes' is idiopathic avascular necrosis of the femoral epiphysis followed by fragmentation and slow re-ossification over years. Outcome depends on keeping the femoral head "contained" in the acetabulum and spherical as it remodels; stiffness (especially loss of abduction) and a younger age at onset influence prognosis — younger children generally do better.
Management is led by paediatric orthopaedics: observation, physiotherapy to keep range, activity modification (swimming and cycling rather than running and jumping), and surgery for some older children. The GP role is recognition, prompt referral, analgesia, school letters and supporting a family through a condition that can last several years.
After SUFE fixation or during Perthes' or JIA, children face weeks to months on crutches or with restricted activity. Missed school and exclusion from PE and friendships drive low mood and social withdrawal — particularly for a teenager who may already feel self-conscious about his weight.
Schools in England have a statutory duty to support pupils with medical conditions (DfE, Supporting pupils at school with medical conditions). Ask for an individual healthcare plan: lift pass, leaving lessons early to avoid crowded corridors, a buddy to carry bags, ground-floor rooms, and an adapted PE role (scoring, coaching) rather than exclusion. Exam access arrangements if exams fall during recovery.
Obesity increases the shear force across the proximal femoral physis during the pubertal growth spurt and is the strongest modifiable risk factor for SUFE, including slips of the other hip. Weight also affects anaesthetic risk and later hip health. But raising weight on the day of an urgent diagnosis risks shame and disengagement.
NICE NG246 (2025) favours respectful, non-stigmatising conversations and multicomponent, family-based interventions for children and young people living with obesity (diet, activity, behaviour change), tailored to the family. Plot BMI centile, ask permission, and focus on the whole family's habits and on activities Kyle can do while recovering (upper-body work, swimming once the surgeon allows).
Physiotherapy is central after SUFE fixation (gait retraining, strengthening, graded return), in Perthes' (range of movement), in JIA (joint protection, strength, function) and in Osgood-Schlatter (load management and strengthening). It is harmful as a first step in undiagnosed hip pathology because it delays diagnosis and loads a slipping physis.
Say it plainly to the parent who asked for physio: "Physio will very likely be part of his recovery — after the surgeons have made the hip safe." For an adolescent with typical Osgood-Schlatter and a normal hip exam, activity modification and strengthening are first-line, with physiotherapy if not settling (see the Reasoning GP Osgood-Schlatter page).
Dose per children’s SPC and local paediatric formulary (by age/weight)
- Ibuprofen is a sensible first choice for probable transient synovitis — its anti-inflammatory action may shorten symptoms (Kermond et al., Ann Emerg Med 2002: RCT of 36 children, median symptom duration 2 vs 4.5 days with placebo)
- Paracetamol if NSAIDs are unsuitable (e.g. dehydration, NSAID-sensitive asthma, chickenpox — see children’s SPC cautions)
- Check what has already been given today before advising the next dose
- Weight-based dosing: record the child's weight
Treat distress, not the number
- NG143: use paracetamol or ibuprofen for a febrile child who appears distressed, not simply to lower the temperature
- Do not give both at the same time; consider alternating only if distress persists or recurs before the next dose is due
- Antipyretics do not prevent febrile seizures
- A febrile child who won't weight-bear or use a limb has an amber NG143 feature, and NG143 asks you to consider septic arthritis/osteomyelitis → same-day assessment for septic arthritis/osteomyelitis
- Codeine under 12: contraindicated for pain (MHRA Drug Safety Update, July 2013); for 12–18-year-olds only for acute moderate pain not relieved by paracetamol or ibuprofen, short course
- Aspirin under 16: avoid (Reye's syndrome — children’s SPC)
- Oral antibiotics "just in case" for a hot joint or febrile limp — send for assessment instead; antibiotics before cultures can obscure the diagnosis
- Oral steroids for an undiagnosed swollen joint — can mask infection and leukaemia; JIA steroids are specialist-directed
"Give this with food or milk, at the dose on the bottle for his age and weight. It helps the pain and the inflammation in the hip. If he's still not walking properly in two days, or he gets a temperature, bring him back straight away — don't just keep giving more medicine."
SCA: pair the prescription with the safety-net. "Ibuprofen and review at 48 hours" scores; "ibuprofen and see how he goes" does not.
"This is for comfort, not a cure. Use the syringe that comes with the bottle and stick to the dose for his weight. Don't give it at the same time as ibuprofen — if you're using both, space them out."
Stating "dose per children’s SPC, by weight" is safer than quoting a number from memory in the exam.
"I'd rather not use stronger painkillers — if paracetamol and ibuprofen aren't enough, that tells me the hip needs looking at again today, not a stronger tablet."
Reaching for codeine for a limping child is a Tasks deduction: severe or escalating pain should trigger reassessment and referral.
"I'm not going to start antibiotics here, because the hospital needs to test the joint first to find the right one — that's why I'm sending him in now rather than giving tablets."
Explaining why you are not giving antibiotics scores in both Tasks and Relating to Others.
"This is taken once a week, on the same day each week — never daily. If she gets a sore throat, fever, mouth ulcers or unusual bruising, contact us for a blood test the same day."
JIA variant: recognising morning stiffness and a limp that improves through the day, and referring within BSPAR timescales, is the GP task — not starting DMARDs.
School & Exams
Post-operative crutches mean stairs, crowded corridors and heavy bags become hazards. Missed lessons accumulate quickly. A letter to school and a request for an individual healthcare plan (DfE statutory guidance on supporting pupils with medical conditions) turns an ad-hoc problem into an organised one.
"Would it help if I wrote to school explaining what's happened and what he'll need — like a lift pass and leaving lessons a few minutes early — so you don't have to argue for it?"Sport, Friends & Identity
For many adolescents, sport is where friendships happen. Being told "no PE" for months can feel like exclusion. Offer a role (scorer, coach's assistant) and a realistic timeline set by the surgeon, and name the good news: most children return to full activity after a stable slip is fixed.
"Kyle, the surgeons will tell you when you can play again — it's usually months, not years. In the meantime, is there a way you can still be part of the team?"Weight, Shame & Stigma
Kyle may already be teased about his weight. Linking his hip directly to his size in the first conversation risks shame and disengagement. NICE NG246 emphasises respectful, non-stigmatising language and family-based approaches. Deal with the hip today; ask permission to talk about weight at follow-up, framed as health and the other hip, not blame.
"At a later appointment, would it be OK to talk as a family about things that can help protect his other hip — like activity and food? No one's to blame for this."Parental Guilt & Family Logistics
"Should I have brought him sooner?" is a common unspoken worry. Knee-presenting SUFE is frequently missed by clinicians too. Acknowledge that and move to the practical: time off work, siblings, transport, parking, how long the admission might be.
"Lots of people — doctors included — are caught out because it feels like the knee. You've done the right thing. What do you need to sort out today to get him to the hospital?"Driving & Transport
Kyle is too young to drive, so the DVLA question does not arise for him — but transport does: he should be taken by car or wheelchair, not walk or cycle. For an older adolescent who drives (17+) and has hip surgery, the DVLA does not set a fixed no-driving period after limb surgery; the driver must be able to control the car safely, including an emergency stop, and should follow the surgeon's advice and check with their insurer.
"Please drive him there rather than letting him walk or get the bus — every step on that leg matters until the surgeons have seen him."Safeguarding Without Accusation
In other variants — a toddler with a fracture, a non-mobile infant with bruising, a story that changes — NICE CG89 requires you to consider maltreatment. The skill is to be open and non-accusatory while following the local pathway: discuss with the safeguarding lead or on-call paediatrician and document the explanation given verbatim.
"With any injury in a young child we always make sure we fully understand how it happened, and sometimes that means the children's team taking a look too. It's a routine part of keeping children safe."Today (Day 0) — Same-Day Orthopaedic Assessment
Phone the on-call orthopaedic registrar; send a referral letter with history, examination (restricted internal rotation, externally rotated gait, normal knee), weight and analgesia given. Non-weight-bearing advice given and understood by Kyle and his mother. Transport arranged. Documented: safety-net, SUFE suspected, parent's physiotherapy request discussed and plan agreed. For other scenarios: septic → emergency admission; under 3 → same-day paediatrics; NG12 features → very urgent FBC or X-ray within 48 h; safeguarding → discuss with lead the same day.
Days 1–7 — Check the Outcome
Confirm Kyle was seen (a quick check of the hospital record or a phone call closes the loop — referrals get lost). Read the discharge letter: stable vs unstable slip, fixation, plan for the other hip, weight-bearing status, follow-up clinic. Update the problem list. Offer a school letter and a fit note for the parent if needed (for her own absence, discuss options). For transient synovitis: the 48-hour review falls here — if improving, see again at about a week; if not, same-day assessment.
2–6 Weeks — Recovery and Coping
Wound healing, pain, crutch use and falls; mood, sleep and school attendance; how the family is coping. Ask specifically about any pain in the other hip, groin, thigh or knee — a contralateral slip can occur and may again present as knee pain. Reinforce physiotherapy and surgeon's activity advice. For suspected JIA: has rheumatology seen the child within the BSPAR 4-week standard? Has eye screening been arranged?
3–6 Months — Return to Activity & Weight Conversation
Graded return to sport per orthopaedics. With permission, the weight conversation as a family: plot BMI centile, explore activity, food and sleep, and offer local family-based weight management services in line with NICE NG246. Screen for low mood or bullying. For Perthes': ongoing orthopaedic surveillance; GP supports activity modification and school letters.
Until Skeletal Maturity — Keep the Hip on the Radar
Orthopaedics usually follow SUFE until the growth plates close. Code the diagnosis so any clinician seeing Kyle with new hip, thigh or knee pain examines both hips and has a low threshold for same-day referral. Longer term, SUFE is associated with femoroacetabular impingement and earlier hip osteoarthritis — relevant if he re-presents with hip pain as a young adult.
Memory rule — "Walk, Warm, Well, Weight, Watch"
At every review of a limping child: Walk — is the gait normalising, and can they weight-bear? Warm — any fever? Well — any new systemic features (pallor, bruising, night pain, weight loss)? Weight — record it (for dosing and, where relevant, BMI centile). Watch — the other hip, the joint above and below, and the safeguarding picture.
| Condition / treatment | Monitor | Timing | Action threshold |
|---|---|---|---|
| Transient synovitis (provisional) | Weight-bearing, gait, temperature, general wellbeing | 48 h after onset; then ~1 week if improving | Worse, febrile, unwell, not weight-bearing, or not settling → same-day hospital assessment. Recurrent or persistent limp → consider Perthes' (hip X-ray, orthopaedics) |
| SUFE — after fixation | Pain in either hip/thigh/knee; gait; weight-bearing status | Each contact until skeletal maturity (orthopaedic follow-up) | New pain on the other side → same-day orthopaedics. Persistent stiffness or limp → orthopaedic review (AVN, chondrolysis, impingement) |
| Perthes' | Hip range (abduction, internal rotation), pain, activity, school | Per orthopaedic plan; GP at each flare | Increasing stiffness or pain → bring forward orthopaedic review |
| JIA | Joint swelling, morning stiffness, function; uveitis screening attendance | Rheumatology within 4 weeks of referral (BSPAR); eye screening per BSPAR/RCOphth schedule | Red or painful eye, photophobia or blurred vision → same-day ophthalmology. Missed eye screening → chase — JIA uveitis is often asymptomatic |
| Methotrexate (JIA) | FBC, LFTs, U&E | Per shared-care protocol | Cytopenia, rising transaminases or intercurrent severe infection → withhold and discuss with specialist. Confirm once-weekly dosing at every issue (MHRA 2020) |
| NG12 investigations | FBC and film; X-ray report | Result reviewed within 48 h | Abnormal FBC/blast cells → same-day paediatric haematology discussion. X-ray suggests sarcoma → very urgent referral (appointment within 48 h). Normal result but symptoms persist → re-examine and reconsider |
| Safeguarding concern | Outcome of strategy discussion; attendance; new injuries | As agreed with children's social care | Any new unexplained injury → repeat referral; record in the child's and linked family records per local policy |
⚠ Three scenario-specific phrases — use these verbatim
Why safety-netting matters beyond clinical care — document it
- Allowing weight-bearing in SUFE; physio referral
- No safety-net for transient synovitis
- Over-labelling "growing pains" without exclusion
Who you are (Kyle's mother)
You've brought your son Kyle, 13, with several weeks of right knee and thigh pain and a limp that's got worse this past week. No clear injury. He's a bit overweight for his age. You're convinced it's a knee problem and want a physiotherapy referral so he can get back to sport. You're slightly impatient and feel it's "obviously his knee".
Hidden concerns (reveal if explored)
Frustration: you feel it's been going on too long and just want it sorted with physio.
Worry (if the doctor seems concerned): you become anxious if told it might be serious — you'll need clear, calm explanation and reassurance it's treatable.
Practicalities: you worry about him missing school and how you'll get to hospital.
Clinical details if asked
- Knee/thigh pain several weeks, worsening; limp; no injury; can still bear weight (limping)
- Overweight; around pubertal age; otherwise well
- No fever, no recent illness, no night pain, no pallor/bruising/lumps, no weight loss/night sweats
- Walks with the right leg/foot turned outwards (you've noticed he "walks funny")
- On examination: knee is normal; the hip is stiff and uncomfortable when rotated inwards
Reactions at key moments
- If the doctor only examines the knee & offers physio: you're satisfied — so a strong candidate must examine the hip and NOT do this.
- On "I need to check his hip": mildly surprised ("but it's his knee"), accepting when explained.
- On the SUFE explanation & urgent referral: anxious but reassured by calm clarity and that it's treatable.
- On non-weight-bearing: you accept it once you understand why.
- Challenge line: "Are you sure? It really seems like it's just his knee — can't he just have physio?"
Resolution: The consultation succeeds if the GP: (1) reasons by age and applies the rule that the hip refers to the knee — examining the hip despite a knee complaint; (2) recognises SUFE (overweight adolescent, externally rotated leg, restricted hip internal rotation, normal knee) and arranges urgent orthopaedic referral with non-weight-bearing, NOT physiotherapy; (3) screens and excludes septic arthritis (weight-bearing/fever) and the NG12 leukaemia red flags, and considers safeguarding; (4) reframes the mother's expectation calmly and clearly, conveying urgency without alarm; (5) safety-nets and supports the family practically. It fails if the GP examines only the knee and refers to physiotherapy, missing SUFE.
0–3y: DDH, septic arthritis, toddler's fracture, NAI. 3–10y: transient synovitis, septic arthritis, Perthes'. 10–16y: SUFE, septic arthritis, Perthes'. Any age: septic arthritis, malignancy (leukaemia), osteomyelitis, JIA, NAI. Always examine the hip in knee pain (SUFE/Perthes' refer to the knee).
🔴 Same-day: won't weight-bear + fever/unwell → septic arthritis (admit, aspirate, IV abx; Kocher); bone pain + pallor/bruising/lymphadenopathy/fever → very urgent FBC within 48 h (NG12; petechiae/hepatosplenomegaly → immediate); acute limp under 3 → same-day paediatrics; suspected NAI → safeguarding (NICE CG89); suspected SUFE → same-day orthopaedics, non-weight-bearing, AP pelvis + frog-lateral X-ray of both hips (cross-table lateral if unstable). 🟠 Urgent specialist: Perthes', DDH, JIA (BSPAR ≤4 weeks). 🟢 Routine: transient synovitis (exclusion; well child; rest/analgesia/safety-net/review). Don't over-label "growing pains".