Reasoning GP · Algorithm · 1-page summary
Hip pain
For: adults and young people with hip, groin, lateral hip or buttock pain in primary care (assessment, first treatment, referral). Not for: ongoing care of the limping child (screen here, then the paediatric pathway). PMR, gout and bone-health follow-up are in the full algorithm.
Core rule: groin pain with restricted internal rotation is the hip joint; lateral pain is usually trochanteric and buttock pain often spinal. A shortened, externally rotated leg after a fall is a hip fracture until X-rayed, and a febrile child who will not weight-bear needs same-day assessment whatever the score.
0Stop — emergency now — history alone is enough to act
- Hip fracture — fall, cannot weight-bear, shortened, externally rotated leg → urgent ambulance to ED; 999 if unstable, major trauma, uncontrolled pain, neurovascular compromise or unsafe transfer. Do not ask them to walk.
- Pale, cold, pulseless leg with sudden severe pain; septic arthritis with shock or instability; open fracture → 999
- Cauda equina — urinary retention or incontinence, saddle anaesthesia, progressive bilateral leg deficit → Immediate ED / spinal; 999 if severe deterioration or cannot transfer. MRI is arranged by the receiving service.
- While waiting: analgesia, immobilise; blood cultures if infection suspected; no antibiotics before aspiration unless septic or unstable. No imaging delay.
1Triage by age, then site — the strongest filter
| Age | Think of |
|---|---|
| <18 | Septic hip, transient synovitis, Perthes (4–10), SUFE, DDH → block 2 |
| 18–40 | FAI, labral tear, inflammatory arthritis, stress fracture, iliopsoas |
| 40–60 | Early OA, FAI, trochanteric pain (GTPS), inflammatory arthritis |
| >60 | OA, hip fracture after trauma, AVN, referred lumbar or vascular pain |
| Site | Groin = joint · lateral = GTPS · buttock = spine/SI joint · knee pain → examine the hip |
2Screen — one row is enough
- Septic hip (any age): acute severe pain ± fever, cannot weight-bear → Same-day ED/orthopaedics. Child with fever and limp → Same-day paediatrics, whatever the Kocher score.
- SUFE — adolescent, hip or knee pain, restricted movement (obesity not required) → no weight-bearing, Same-day orthopaedics.
- Pain after a fall, even if walking → Same-day X-ray. X-ray normal, suspicion high → MRI (CT if not within 24 h).
- AVN risk (steroids, alcohol, sickle cell) + sudden severe pain → Urgent MRI, orthopaedics; cannot weight-bear → Same-day ED.
- Bone pain at rest or night, swelling, or cancer + new focal pain → X-ray; pathological fracture → Same-day. Child: consider Very urgent X-ray; adult X-ray suggests sarcoma → consider suspected cancer pathway.
3Assess — only once blocks 0–2 are answered
☐ Gait and weight-bearing (never force) ☐ Internal rotation and flexion vs other side; log roll ☐ Greater trochanter tenderness ☐ Spine, SLR, SI joints, knee ☐ Abdomen, hernia, genitals if indicated ☐ Leg length, pulses, neurology if trauma or vascular
OA is clinical (45+, activity-related, no or ≤30 min stiffness): no imaging. X-ray if atypical, trauma, SUFE, Perthes, AVN or malignancy. Not routine: MRI for OA, X-ray for GTPS, blanket HLA-B27 or PSA.
4Classify — only if the screen is negative
- Hip OA — 45+, groin pain on activity, reduced internal rotation → block 5.
- GTPS — lateral, tender trochanter, worse lying on that side.
- FAI / labral — young, active; groin pain on deep flexion, catching → physio first.
- Lumbar referred — buttock ± posterior thigh, positive SLR, normal hip movement → spinal, not hip OA.
- PMR — over 50, bilateral shoulder and hip girdle, stiffness >45 min; exclude mimics. GCA features → Same-day specialist.
- Uncertain — say so; image per block 3, set a review, re-check spine.
5Treat today — doses: NICE/SPC, BNF, local formulary
- Hip OA: exercise and weight loss are core; stick in the opposite hand. Consider topical, then oral NSAID + PPI (check eGFR, BP, CV risk); consider steroid injection short-term. Not routine paracetamol or opioids; no hyaluronan.
- GTPS: no leg crossing or lying on that side; gluteal loading physio, no ITB stretching; steroid injection short-term, selected only.
- PMR: prednisolone 15 mg; no response in 1 week → rethink. 12.5 mg at 3 weeks, 10 mg at 6, then −1 mg every 4–8 weeks. Assess bone protection; never stop suddenly.
6Refer routinely
- Orthopaedics: OA substantially affecting quality of life, non-surgical care ineffective or unsuitable; no score threshold.
- Urgent rheumatology: persistent synovitis — do not wait for RF, anti-CCP or CRP (NG100); axial SpA per NG65; atypical PMR.
- MSK: GTPS, FAI or labral pain persisting despite physio. Suspected Perthes, normal X-ray → paediatric orthopaedics.
- After a hip fracture: Fracture Liaison Service, falls service, bone health per NOGG.
7Never reassure by
- Walking after a fall — impacted or occult fractures can weight-bear.
- A normal X-ray in occult fracture, early AVN, Perthes.
- Normal temperature, WCC or CRP, or a low Kocher score, in a possible septic hip.
- Knee pain in a child or adolescent without examining the hip (SUFE).
- Calling lateral or buttock pain "hip OA".
- Antibiotics before aspiration for a painful hip replacement.
8Safety-net — say it, then document it
999 “Call 999 if you fall and cannot stand or your leg looks short or turned out — don't try to walk; sudden severe pain with a pale, cold leg; both legs weak with trouble passing urine or a numb bottom; or fever, severe hip pain and feeling very unwell.”
Same day: “A hot, very painful hip with fever, or you can't put weight on it; new hip pain after a fall even if you can walk; a child with a limp and fever; worse pain if you have cancer; sudden severe groin pain on long-term steroids; new pain, swelling or fever after a hip replacement — contact us today.” Return if worse, locking, giving way, night sweats or weight loss.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies; weight-bearing checked
Site localised; hip, spine and knee examined
One diagnosis fits, or uncertainty and imaging plan stated
NSAID or steroid risks checked; PMR: GCA asked
Safety-net given; review owner and date set
Summary of the full Reasoning GP hip pain algorithm, which holds the history, examination tests, investigations, PMR and inflammatory arthritis detail, follow-up schedule and evidence. Sources: NICE NG226, CG124, NG12 (updated April 2026), NG100, NG65, NG219; BSR PMR guideline; NOGG; MHRA. Clinical reference — follow local pathways and check doses: NICE/SPC, BNF.