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Osteoarthritic Knee Pain

Red Flags

History of trauma followed by pain
Sudden onset severe pain
Persistent aching pain not related to activity
Weight bearing not possible due to the pain
Patient systemically ill with a fever, and knee movement severely painful on minimal movement

If red flags, Urgent Telephonic Consult With Orthopaedic Registrar or Consultant

Contact the Orthopaedic Registrar on call at Tauranga Public Hospital at 07 5798044 and paging the registrar.

Contact the Orthopaedic Consultant at Whakatane Hospital on 07 306 0777.


  1. History

    • Past history of injury, knee joint abnormality, knee joint surgery, or malignancy.
    • Pain - where (can be referred from hip, low back, and ankle) , how severe, how often, when straightening knee fully, when bending knee fully, when walking on the flat, when walking up or down stairs, in bed at night, sitting or lying, standing upright, walking on a hard surface, walking on an uneven surface.
    • Stiffness - morning stiffness and later in the day after resting.
    • Giving way.
    • Locking.
    • Joint sounds/sensations - grinding, clicking, or other noise.
    • Functions of daily living - going up or down stairs, standing from from sitting, standing, bending, walking on flat or uneven surface, getting in and out of a car, going shopping, putting on or taking off socks/stockings, getting out of bed, lying and turning over in bed, getting in or out of a bath, sitting, getting on and off a toilet, domestic chores, kneeling, squatting, running, twisting on loaded leg.
    • Quality of life - degree to which knee pain interferes with confidence and ability to live usual life.
    • Knee assessment (history and examination) (
  2. Examination

    • Look at the patient - note if patient pyrexial or unwell. Measure weight and BMI.
    • Look at the patient's gait - note any limp.
    • Look at the joint - note joint swelling and deformity (valgus/varus).
    • Look at the muscles - note muscle wasting or contracture and compare sides.
    • Examine for an effusion using patellar tap and the massage (bulge) test.
    • Feel for site(s) of tenderness including the patellofemoral joint, medial and lateral joint including MCL and LCL.
    • Examine the popliteal fossa - note sites of tenderness, Baker's cyst, or vascular abnormality.
    • Assess range of movement (active and passive and compare both knees):
      • Knee flexion normally 3 to 140 degrees (115 degrees required for most activities of daily living).
      • Feel for crepitus with a hand on the knee cap.
      • Note fixed flexion deformity.
      • Note clicks or grinding on movement.
    • Examine the knee ligaments for laxity:
      • MCL and LCL - look for adduction and abduction movement with knee flexed to 30 degrees.
      • ACL - Anterior Drawer test (pull tibia forward when sitting on the patient's foot with patient prone with knee flexed to 90 degrees), Lachman's test (pull/push tibia forward and push/pull thigh backward with knee flexed to 15 to 20 degrees), and Pivot Shift test (best done by Orthopaedic surgeon).
      • PCL - Posterior Drawer test (as for Anterior Drawer test but push tibia backwards), Posterior Sag test (observe knees with patient prone and knees flexed to 90 degrees. Look for posterior sag).
    • Other tests: Vascular examination of lower limb.
      • Patellar apprehension test (apply pressure to medial patella when patient prone with knee extended - then, flex the knee to 30 degrees and note lateral patella movement and any patient apprehension).
      • Knee joint aspiration if there is an effusion.
      • Examine the patient's hips, ankles and lumbar spine. Note evidence of OA elsewhere and any referred pain.
    • Neurological examination of lower limb.
    • Knee assessment (history and examination) -
    • Embed video:
  3. Xray Knee

    • A Knee Xray (weight-bearing AP and lateral) is required before referring the patient for consideration of a Total Knee Replacement.
      • As patients require an Xray within 6 months of their surgery if a recent Xray confirming OA exists it is not necessary to repeat this.
      • Always attach the knee Xray report to any referral as reports and films are not routinely available at grading.
    • An Urgent Knee Xray is required for:
    • Other indications for Knee Xray:
      • Pain and functional impairment are significant.
      • Pain when the patient has had a previous knee joint replacement.
      • Recurrent presentation with same symptoms.
      • Suspected bone malignancy (primary or metastatic).
      • Knee locking, restricted movement, or deformity.
    • Xray signs of osteoathritis:
      • Joint space narrowing
      • Subchondral sclerosis
      • Subchondral cysts
      • Osteophytes
    • Note that when a septic arthritis or osteomyelitis is suspected or where there is a haemarthrosis then refer urgently to the Orthopaedic Registrar on call.
  4. Additional investigations

    • To exclude alternative diagnoses. These may include:
      • CRP
      • ESR
      • FBC
      • Rheumatoid Factor
      • Anti-CCP


  1. If red flags, Urgent Telephonic Consult with Orthopaedic Registrar or Consultant

    • Tauranga: Contact the Orthopaedic Registrar on call at Tauranga Public Hospital at 07 5798044 and paging the registrar.
    • Whakatane: Contact the Orthopaedic Consultant at Whakatane Hospital on 07 306 0777.
  2. If the patient is not likely to meet criteria for knee replacement, conservative management of Osteoarthritis Pain and Function

  3. If the patient is likely to meet criteria for knee replacement, refer to orthopaedic clinic

      • Moderate to severe persistent pain not relieved by a course of conservative management (e.g. paracetamol + NSAID and including weight management when appropriate).
        • Pain severe when present constantly and interferes with most activities of daily living despite analgesia.
      • Severe functional limitation.
        • Walking capacity of less than 15 minutes.
        • Needs a walking aid.
        • Employment restricted.
        • Independence at risk.
        • No longer able to act as a carer if caring for someone else in need.
      • Radiographic evidence of joint damage.
      • Fit for List Health Screen assessment
      • A patient is considered unfit for surgery when they have had:
        • Myocardial infarction in the last 6 months.
        • Cardiac surgery in the last 6 months.
        • Unstable angina pectoris or angina pectoris at rest or on minimal effort (class 3 or 4).
        • Crescendo TIAs.
        • Uncontrolled hypertension (> 160/90).
        • Unexplained anaemia.
        • Chronic skin sepsis (refer to Infectious Diseases Specialist).
        • BMI > 40
    • How to refer to Orthopaedic Clinic
      • Use the referral form available as an option on the Best Practice eReferral form or refer the patient by faxing or posting a referral to the Tauranga Hospital Referral Centre for processing.
    • Referral Assessment Process
      • Referral assessed by orthopaedic team member
      • Patient and GP/referrer sent a letter identifying expected wait or declining if referral does not meet access criteria.
      • Physio appointment preceding FSA.
        • Physio appointment purpose: To provide a Musculo-skeletal assessment of the patients who are referred for Hip or Knee Joint surgery which will inform the Surgeon seeing the patient at their clinic appointment and enable appropriate selection of patients for surgery.    It will help to prioritise patients who score similar subjective scores but who may have very different functional scores. It will assist us to provide a fairer system by having an independent person performing the assessment. The assessment will also provide alternative options for some patients such as Physiotherapy classes and potentially allow some of these patients to return to Primary care without having a Surgical treatment.
      • Orthopaedic Specialist FSA appointment within 4 months of referral -decision regarding treatment made and it is determined whether the funding criteria has been met.
    • Funding criteria:
      • The BOPDHB has a threshold level which allows equity of access to patients ensuring those with the greatest need will be the ones who are offered Surgical treatment.
      • If the patient does not meet funding criteria, they are referred back to the patient's GP for conservative management. The patient may be given treatment recommendations, referred for physiotherapy and given a review appointment.
      • When the patient is likely to meet the criteria, the patient's GP will need to refer the patient back to the Orthopaedic Clinic for reassessment.
  4. If the patient is accepted for surgery, patient on Treatment List

    • Pre-admission assessment aims to identify any problems that could increase the risk of surgery/anaesthesia or interfere with the patient's recovery after surgery:
      • Lifestyle risks e.g. smoking, excessive alcohol use
      • Obesity
      • Skin sepsis
      • Check urine for infection. A MSU will be requested 2 weeks before surgery
      • Treat bacteriuria as well as overt Urinary Tract Infections
      • Undiagnosed or poorly controlled hypertension
      • Undiagnosed or untreated anaemia
      • Undiagnosed or poorly controlled atrial fibrillation
      • Undiagnosed or poorly controlled diabetes mellitus
      • Undiagnosed or poorly controlled congestive heart failure
      • Undiagnosed or poorly controlled ischaemic heart disease
      • Poor oral health
      • Poor cognitive function (low MMSE or Abbreviated Mental Test Score)
      • Other problems e.g. renal impairment, liver impairment, obstructive sleep apnoea, and cervical spinal spondylosis/arthritis
    • The GP is involved as necessary to manage any outstanding issues that may delay surgery.
    • GP ongoing review:
    • Specific concerns
      • Overweight patients (BMI > 35): send dietitians referral via BPAC ereferrals
      • Underweight patients (BMI < 20): refer to dietitian at BOPDHB
        • The target for joint replacement surgery is a BMI of < 40
        • Dietitian referral
        • Exercise prescription (Green prescription)
        • Dietitian referral
      • Smoking cessation (Quitline)
  5. Inpatient Stay

  6. Post-Discharge Care

    • After knee replacement surgery, notify the Orthopaedic Registrar on call or the operating Consultant if one of the following complications occur:
      1. Thromboembolism
        • Suspected DVT should be diagnosed and managed in the community via CPO where available.
        • Please advise the orthopaedic team preferably using the referral for advice option in eReferrals that a DVT has occurred and is being managed in the community.
        • If the patient is at high risk for PE or there are other issues precluding community management, please refer to the Medical Registrar on call.
      2. Infection
        • If there is any suggestion of deep infection requiring antibiotics the patient should be referred for review by the Orthopaedic registrar on call or the Consultant concerned.
        • Distant cellulitis including on the limb distal to the replacement can be managed by the GP.
        • CRP is not considered a useful diagnostic tool to exclude infection in the 6 weeks post-operatively.
      • Analgesia:
        • Patients are discharged from hospital with advice to continue with Regular Paracetamol and with a short-term opiate such as Oxynorm/Oxycontin for 3 -4 days.
      • Wound Care:
        • Patients being discharged with staples in their wound will have these removed by the District Nurse, or at the GP.
        • If the patient has dissolvable sutures, the wound is left covered with an occlusive dressing. The patient is given instruction to remove the dressing after 7 days.
        • The patient is advised to see their GP if there is any bleeding, redness or heat at the wound site, severe pain, increased wound ooze or increased swelling at the wound site.
      • District Nurse:
        • A patient is only referred to a District Nurse for wound care, or if they are having input into home help or personal cares.
        • If after 6 weeks ongoing support is required regards home and personal assistance, the DN advises Support Net who will provide an assessment and if the patient qualities, this will be provided and funded by Support Net.
      • Physiotherapy:
        • Physiotherapy post TKHJR is case dependent rather than routine as most do not require.
      • Consultant follow-up:
        • Some patients will be called back at 2 - 3 weeks by the Consultant but those are progressing as expected will be sent an appointment for a follow-up clinic visit 6 weeks post-operatively.
      • Longer term follow-up:
        • Following the 6-week clinic appointment, patients are recalled at one year post-op for a check with an x-ray. After 5 years they are sent a scoring sheet to complete and depending on these results they will be discharged or recalled for consultation.


Disclaimer: These pathways, for the care and management of patients within Bay of Plenty, have been developed jointly by primary and secondary care clinicians. They provide guidance for General Practice teams to diagnose and manage patients suffering from a number of different conditions, and contain patient information resources. The pathways are maps of publicly-funded services accessed by referral from the community, and are strongly evidence based, but are not full clinical guidelines. As the pathways are suggested guidance only, while using them you must exercise your own clinical judgement and pertinent clinical data when treating your patient. This site is intended to be flexible and frequently updated. While every effort has been made to ensure accuracy, all information should be verified.