Knee Pain (Adults)

Acute Knee Injury Pathway

Common acute knee injury differential diagnoses:

Ligament injury (most commonly anterior cruciate ligament)

• Clear history of significant twisting injury
• Audible “pop” at time of injury
• Rapid swelling < 1 hour
• Instability symptoms
• Difficulty weight bearing
• Ligamentous laxity on examination (Lachman Test, Anterior Drawer test, Collateral ligament stress tests)

Acute meniscus injury (non degenerative)

• Recent twisting injury
• Swelling (slower than in cruciate ligament rupture >1 hour)
• May present with true locking or “giving way”
• May have block to knee extension
• Localised joint line pain and tenderness

Patella instability

• Clear history of patella dislocation (usually lateral)
• Quick swelling
• Patella apprehension test positive
• J-tracking

Overload knee pain

• Triggered by an increase in activity levels/ joint loading
• No trauma/ injury as such
• May have muscle weakness
• Common in degenerative/ OA knee (not for acute knee clinic)

Referral to Acute Knee Clinic if below criteria satisfied:

• Acute injury with instability (within last six weeks)
• Significant injury, likely to require surgical intervention/use of a brace
• Suspected ligament injury from history or examination
• Suspected meniscal tear with locking (inability to fully extend)
• First time traumatic patella dislocation

Acute Knee Clinic:

• The Acute Knee Clinic is held every Thursday morning at Rugby St Cross
• Contact the orthopaedic secretaries by phone, mark your referral letter “Urgent – Acute Knee Clinic”.
• Alternatively, you can phone the consultant on duty in Fracture Clinic, open seven days a week.
• These referrals can be sent through the NHS eReferral system, using the dedicated service (ACUTE- Trauma and Orthopaedics RAS- (Shoulder, Elbow, Hand, Wrist, Knee) UHCW- RKB).

Please note this service is not for degenerative knee conditions

Referrals will be reviewed by a Clinician and an appointment will be allocated to the patient or in some circumstances the referral may be redirected to a more suitable service

Referral to routine elective knee clinic if below criteria satisfied (chronic soft tissue knee conditions (> 6-8 weeks old)

• Chronic instability impacting on patient’s functional ability, refractory to GP and self-management
• Suspected meniscal injury – symptoms interfere with the ability to work or persist despite 6–8 weeks of rehabilitation by a physiotherapist
• Suspected medial or lateral collateral ligament injury – symptoms interfere with the ability to work or persist despite 4–6 weeks of rehabilitation by a physiotherapist
• Suspected ACL injury impacting functional ability or intention to return to pivoting sports, e.g. football, rugby, netball, squash etc.
• Suspected PCL injury impacting functional ability
• Suspected meniscal injury impacting functional ability
• Recurrent patella dislocation
• Patient amenable to surgical intervention where relevant

Non-traumatic Knee Pain Pathway

Red Flags

Septic arthritis

• Acute hot, painful, swollen knee +/-
• Skin discolouration
• Fever
• Feeling unwell
• Recent surgery
• Requires immediate A+E referral

Spontaneous Osteonecrosis of Knee (SONK)

• Minimal/ no trauma
• Constant severe pain
• Increased with weight bearing
• Night pain
• Most commonly affects females > 55
• Medial condyle most affected

Rheumatological (gout/ pseudogout)

• See rheumatology homepage
• FBC, ESR, CRP, RA screen, anti CCP and uric acid
• If rheumatological condition strongly suspected, consider urgent referral to rheumatology hot clinic 

Knee Osteoarthritis

• Include links for prior approvement TKR
• Useful links and documents – Trek knee health https://trekeducation.org/knee-health/ (patient and clinician)
• NICE guideline link https://www.nice.org.uk/guidance/ng226/resources/visual-summary-on-the-management-of-osteoarthritis-pdf-11251842157

GP management and self-management

For adult knee pain where likely diagnosis is osteoarthritis

Pharmacological management

• Offer a topical non-steroidal anti-inflammatory drug (NSAID) for knee osteoarthritis as per drug formulary
• Consider an oral NSAID if topical medicines are ineffective or unsuitable and offer a gastroprotective treatment alongside
• Do not offer paracetamol or weak opioids routinely, unless used infrequently for short-term pain relief or all other treatments are ineffective or unsuitable

Exercise

• Consider strengthening exercises to include gluteal, quads, hamstring and calf muscle strengthening
• Encourage general aerobic fitness

Weight management (for people living with obesity or overweight):

• Advise that weight loss will improve quality of life and physical function, and reduce pain
• support them to choose a weight loss goal
• Explain that any weight loss is likely to be beneficial but losing 10% is likely to be better than 5%.

Intra-articular corticosteroid injection:

• Intra-articular steroid injection/s (moderate to severe pain) – most suitable for acute flare-up of pain and swelling
• Consider intra-articular corticosteroid injections for short-term relief when other pharmacological treatments are ineffective or unsuitable or to support therapeutic exercise

Investigations:

Chronic knee pain – suspecting diagnosis of Osteoarthritis

• Primary investigation OA series x-ray (not MRI)
• Otherwise MSK physio service will decide on whether imaging is appropriate
• If patient <40 with recent history of fever – consider FBC, ESR, CRP and urgent synovial fluid analysis

Anterior Knee Pain

Characteristics of anterior knee pain:

• It is common (annual prevalence in general population males = 15.5% females = 29.2%
• Pain is usually at the front of or all over knee
• Often bilateral
• Exacerbated by stairs/hills/squatting/sitting long time
• Pseudo-mechanical symptoms (regular, transient)
• Usually no history of injury

Primary care management of anterior knee pain:

• Analgesics/NSAIDs, walking aid, weight management (especially if BMI >30)
• Advise to stay active, continue low impact activities
• Radiology usually not required
• No need for MRI
• Consider plain X-ray if age > 45
• Consider referral to physiotherapy if no improvement after 6 weeks

Painful Arthroplasty Pathway

Post arthroplasty infection concern

If systemically well and procedure done locally to discuss with secretary of consultant (on discharge summary) to arrange urgent outpatient appointment.

If systemically unwell (raised temperature/ heart rate), or procedure not done locally to discuss with ortho SPR on call.

References:

Horga, L.M., Hirschmann, A.C., Henckel, J. et al. Prevalence of abnormal findings in 230 knees of asymptomatic adults using 3.0 T MRI. Skeletal Radiol 49, 1099–1107 (2020). https://doi.org/10.1007/s00256-020-03394-z

Smith BE, Selfe J, Thacker D, Hendrick P, Bateman M, Moffatt F, Rathleff MS, Smith TO, Logan P. Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. PLoS One. 2018 Jan 11;13(1):e0190892. doi: 10.1371/journal.pone.0190892. PMID: 29324820; PMCID: PMC5764329.

Steroid Injections

Community Physiotherapy are now injecting all patients, both high and low risk, leaving 2 weeks before or after Covid vaccination

Steroid joint injections are not currently being performed at UHCW in Musculo-Skeletal / Orthopaedics / Radiology. Please do not currently refer to UHCW for this purpose

GP Gateway Information

Please note GP Gateway has separate pages on:

Knee Arthroscopy

Knee Instability

Referral to Adult Physiotherapy Service – Coventry

If patients have ongoing musculoskeletal knee pain and have not improved with relative rest or analgesic advice, refer to the Adult Physiotherapy Service – Coventry. Here they will be assessed and treated with the following:

• Advice and education
• Specific Exercises
• Classes – for Patello-Femoral Pain and Osteoarthritis of the knee
• Manual therapy/ soft tissue technique
• Provision of walking aids
• Taping
• Acupuncture
• Injection – Blind or Ultrasound Guided – Intra-articular only. No soft tissue injections

Referral to Secondary Care (Total Knee Replacement TKR)

Where Primary Knee Replacement is strongly indicated Prior Approval for Treatment (using the appropriate referral form – see right) will be required.

Referral Criteria:

Patients shall be eligible for surgery if the following criteria is met in either Section A B or C:

Section A :All boxes in section A need to be ticked to meet the criteria for referral

Patients shall be eligible for surgery if ALL of the following criteria are met:

• The patient has been referred to and managed by a musculoskeletal (MSK) service AND
• The patient has a BMI below 35 AND
• Please confirm that the patient is supported by a primary care and/or community service referral      AND
• Please confirm that conservative means (e.g. Analgesics, NSAIDS, physiotherapy, advice on walking aids, home adaptations, curtailment of inappropriate activities and general counselling as regards to the potential benefits of joint replacement) have been exhausted and failed to alleviate the patient’s pain and disability AND
• Please confirm that the patient’s pain and disability is sufficiently significant to interfere with the patients’ daily life and or ability to sleep AND
• Please confirm that the patient accepts and wants surgery                                  

Section B

Patient has a BMI of 35 or over but mobility is so compromised that they are in immediate danger of losing their independence and that joint replacement would relieve this threat

Loss of Independence – Unable to maintain activities of daily living. Activities of daily living- 4 out of 6 needed to require assistance 

• Dressing
• Walking
• Transferring from Chair
• Bathing
• Climbing Stairs
• Driving

Section C

Patient has a BMI of 35 or over but the destruction of their joint is of such severity that delaying surgical correction would increase technical difficulty of the procedure (Recent x-ray report required)

If the patient does not meet any of the above criteria and has a BMI of 35 or over:                                                                                                                

 If the patient does not meet any of the above criteria and has a BMI of 35 or over they will be referred by their GP to weight management services and will be expected to engage with the services to achieve the required BMI.

Should the patient’s BMI fall below 35 then the patient would be eligible for surgery in line with the policy criteria.

If this weight loss cannot be achieved the patient will be eligible for referral for surgery from two years after the documented date of the GP referral to weight management services for the purpose of weight loss prior to surgery.

Smoking cessation

Smoking is the biggest cause of post-operative complications. Please encourage smokers to stop, at least eight weeks before their operation.