Hip Osteoarthritis

History: groin pain is the most typical site - deep, aching, often poorly localised, with the patient cupping the anterior groin (the C-sign). Pain is worse with weight-bearing, walking, stairs (especially ascending), getting in and out of cars, and putting on shoes and socks. Eased by rest in a mechanical pattern. Morning stiffness is typically under 30 minutes (longer suggests inflammatory arthritis). Walking distance progressively reduces. Referred pain follows the femoral (anterior thigh), obturator (medial thigh and knee), and sciatic (buttock and posterior thigh) territories - knee pain as the presenting complaint is a classic exam scenario. Ask about childhood hip conditions (DDH, Perthes, SUFE), previous injury, inflammatory joint disease, corticosteroid use, and alcohol excess (AVN risk).

Examination: antalgic or Trendelenburg gait, muscle wasting (gluteal, quadriceps), leg length discrepancy. Range of movement is the most important part of the examination - internal rotation is typically the first movement lost and the most sensitive indicator of intra-articular hip pathology. Assess with the hip flexed to 90 degrees. The capsular pattern is most restriction of internal rotation, then flexion, then abduction.

• •Thomas test: detects fixed flexion deformity, a feature of advanced OA
• •Trendelenburg test: positive if the pelvis drops on the unsupported side (gluteus medius weakness on the stance side)
• •FABER and FADIR: FABER stresses hip and SIJ; FADIR provokes anterior groin pain from impingement or labral pathology
• •Always examine the knee and lumbar spine - hip OA refers to the knee, and lumbar pathology mimics hip pain. Oxford Hip Score is the standard UK outcome measure

Red flags: acute inability to weight-bear (fracture); hot swollen joint with fever (septic arthritis emergency); night pain unrelieved by rest with weight loss (malignancy); sudden severe pain with corticosteroid or alcohol exposure (AVN); hip OA in a young patient (secondary causes).

Differentials: FAI, labral tear, greater trochanteric pain syndrome (lateral, not groin), lumbar radiculopathy (L2-L3), spinal stenosis, SIJ dysfunction, femoral neck stress fracture, AVN, inflammatory arthritis, and inguinal or adductor pathology.

Per NICE NG226, hip OA is usually a clinical diagnosis. In adults aged 45 or over with activity-related joint pain and morning stiffness of 30 minutes or less, OA can be diagnosed clinically without investigations.

Plain radiographs (AP pelvis with or without lateral hip): not routinely required for diagnosis. Indicated when diagnosis is uncertain, presentation is atypical, a secondary cause is suspected, or pre-operative planning is needed. The four cardinal radiographic features are joint space narrowing (superolateral in primary hip OA), subchondral sclerosis, osteophytes, and subchondral cysts.

Radiographic severity correlates poorly with symptoms.

Bloods are not required for typical OA; reserve for suspected inflammatory arthritis or AVN risk. MRI is not routinely required and is reserved for suspected AVN (where it detects disease before plain X-ray turns positive), femoral neck stress fracture, labral tear, or an unclear clinical picture. Ultrasound has a limited role - effusion detection and aspiration guidance. Joint aspiration is performed when an acute hot swollen joint requires exclusion of septic arthritis or crystal arthropathy.

Per NICE NG226 (Osteoarthritis: care and management, 2022). Hip OA is one of three joints (hip, knee, shoulder) for which the joint-replacement referral recommendation directly applies.

Core treatments offered to all per NG226:

• •Education and self-management: explain OA is manageable; avoid "wear and tear" or "bone on bone" language; explain exercise is beneficial and will not damage the joint
• •Therapeutic exercise: gluteal strengthening is the most important target (gluteus medius and maximus). Add quadriceps strengthening, range-of-movement exercises, and aerobic fitness. Progressive resistance training is the evidence-based approach
• •Weight management: a core treatment for people living with overweight or obesity. Modest weight loss (5-10%) produces clinically meaningful improvement

Manual therapy: consider only alongside therapeutic exercise, not as a standalone treatment.

Pharmacological per NG226:

• •Consider topical NSAID before oral. Hip depth limits absorption but NICE recommends considering topical first
• •If topical is ineffective or unsuitable, consider oral NSAID at the lowest effective dose for the shortest period, with gastroprotection
• •Do not routinely offer paracetamol or weak opioids except infrequently for short-term relief when other options are unsuitable
• •Do not offer strong opioids, glucosamine, chondroitin, acupuncture, dry needling, intra-articular hyaluronan, or electrotherapy

Intra-articular corticosteroid injection: consider when other pharmacological treatments are ineffective or unsuitable or to support exercise. Provides short-term relief. UK hip injections are image-guided (USS or fluoroscopy). Evidence is more limited than for knee OA. Warn diabetic patients about transient hyperglycaemia.

Adjuncts: walking stick in the contralateral hand reduces hip joint loading. Cushioned footwear. NG226 advises against routine insoles, braces, tape, splints, or supports unless specifically indicated.

Referral for joint replacement: per NG226, consider referral when quality of life is substantially affected despite non-surgical management. Do not use any specific X-ray grade, pain score, or BMI as a threshold or barrier. Do not exclude based on age, sex, smoking, comorbidities, or obesity. Scoring tools may support but not override shared decision-making.

Surgical options:

• •Total hip replacement (THR) is the standard option and highly cost-effective. NJR data shows a 15-year cumulative revision rate now below 5%. Risks include infection, dislocation, VTE, periprosthetic fracture, leg length discrepancy, nerve injury, and revision
• •Hip resurfacing is bone-conserving, usually used in younger active males with good bone stock. Metal-on-metal bearing concerns have significantly reduced its use; existing MoM device holders need ongoing MHRA surveillance. Not suitable for women of childbearing age
• •Hip arthroscopy is not for established OA per NG226; it has a role in pre-arthritic conditions (FAI, labral tear)

Prehabilitation per GIRFT principles: pre-operative optimisation improves outcomes. Strengthening (gluteal and quadriceps with progressive resistance training), aerobic fitness, weight optimisation, smoking cessation, anaemia correction, diabetic optimisation.

Non-surgical exercise therapy: progressive resistance training for gluteal strengthening (side-lying abduction, clamshells, standing hip abduction, single-leg stance) is the most important target. Add quadriceps strengthening, hip range-of-movement, functional exercises (sit-to-stand, step-ups), and a walking programme. Aquatic exercise is useful when land-based is too painful.

Walking aid: stick in the contralateral hand, correct height, correct technique.

Post-THR: UK enhanced recovery pathways are standard. Day-of-surgery mobilisation, weight-bearing as tolerated. Hip precautions vary by approach - posterior approach restricts flexion over 90 degrees, adduction, and internal rotation; anterior approach is less restrictive. Progressive strengthening, range-of-movement, and gait retraining. Return to driving at 4-6 weeks, light work 6-12 weeks, manual work at 12+ weeks.

Falls prevention: balance, strength, environmental hazards, medication review, vision assessment.

• •NICE NG226 Osteoarthritis: care and management (2022): UK pathway covering core treatments (education, exercise, weight management), pharmacology (topical NSAID first, oral NSAID with gastroprotection second), and joint-replacement referral without age, BMI, or comorbidity exclusions.
• •National Joint Registry annual reports: real-world UK THR survival data with the 15-year cumulative revision rate now below 5%.
• •GIRFT Best Practice Guide for Hip Replacement: NHS framework for prehabilitation, surgery, and enhanced recovery in elective hip surgery.
• •Kellgren-Lawrence radiographic grading (1957): standard 0-4 OA radiographic severity scale; correlates poorly with symptoms.
• •Oxford Hip Score (Dawson et al., 1996): UK patient-reported outcome measure for hip pain and function.
• •MHRA Metal-on-Metal hip surveillance guidance: ongoing follow-up requirements for patients with relevant MoM implants.

• •Internal rotation is the first movement lost in hip OA and the most sensitive indicator of intra-articular hip pathology. Reduced painful internal rotation plus groin pain = hip OA until proven otherwise.
• •Hip OA refers pain to the knee. If a patient presents with knee pain and a normal knee examination, examine the hip - a classic exam scenario.
• •GTPS is lateral hip pain over the trochanter. Hip OA is groin pain with the C-sign. The distinction is tested constantly.
• •NICE NG226 do-not-offer list is heavily examined: no paracetamol or weak opioids routinely, no strong opioids, no glucosamine or chondroitin, no acupuncture or dry needling, no intra-articular hyaluronan, no electrotherapy, and no routine insoles or braces. Manual therapy only alongside exercise.
• •Do NOT exclude patients from joint-replacement referral because of age, BMI, smoking, or comorbidities (NG226).
• •Hip OA in a patient under 50 = always look for secondary causes (DDH, Perthes, SUFE, FAI, AVN, previous fracture or infection).