Knee OSCE Examination

1. Introduction
2. General Inspection
3. Gait Assessment
4. Look (Standing)
5. Look (Lying)
6. Knee Anatomy
7. Feel (Temperature and Palpation)
8. Feel (Effusion Tests)
9. Move (Range of Movement)
10. Patellofemoral Assessment
11. Special Tests – Cruciate Ligaments
12. Special Tests – Collateral Ligaments
13. Special Tests – Menisci
14. Completing the Examination
15. Quiz

Wash your hands and don personal protective equipment if appropriate.

Introduce yourself to the patient and ensure to mention your grade e.g. 3rd year medical student/junior doctor/consultant.

Confirm the patient’s details taking 3 points of identification usually; full name, date of birth and NHS/hospital number.

Briefly explain the examination and gain consent, for example: “I’d like to examine your knees today. This will involve looking at and feeling both knees, moving them, and doing some specific tests. Is that alright?”

Ask the patient if they have any pain anywhere before you begin, and reassure them you will stop if they become uncomfortable. This is both courteous and clinically important, as pain often localises the underlying pathology.

Adequately expose both lower limbs from the groin down so that the knees, thighs and lower legs can be compared directly. The patient should ideally be in shorts. Begin with the patient standing so you can assess alignment and gait.

Take a moment to look at the patient as a whole and at the area around the bed. Look for mobility aids such as walking sticks, crutches, a frame or a wheelchair, which suggest reduced weight-bearing ability or instability. Note any knee braces, splints or supports, and look for prescriptions or analgesia that hint at chronic pain.

Assess whether the patient appears comfortable or in distress, and whether they look systemically well. Note the patient’s body habitus: a raised body weight loads the knee heavily and is an important risk factor for both osteoarthritis and slower recovery from injury. Generalised features such as a rheumatoid hand deformity or a psoriatic rash may point towards an inflammatory arthropathy affecting the knee.

Ask the patient to walk a short distance, turn, and walk back, while you observe the whole gait cycle. The normal cycle moves through heel strike, foot flat, mid-stance, heel off and toe off; pain or weakness disrupts these phases.

An antalgic gait, where the patient spends as little time as possible bearing weight on the painful leg (a shortened stance phase), is the classic finding of a painful knee, for example in osteoarthritis or following injury. Look also for an unstable or ‘giving way’ gait, which suggests ligamentous injury or quadriceps weakness, and for a stiff knee that the patient swings out to the side (circumduction) because they cannot flex it.

Note any leg-length discrepancy, which may be either the cause or the consequence of knee pathology, and watch how confidently the patient turns, as turning slowly often reflects pain or instability.

Glance at the patient’s footwear as well: uneven sole wear can betray an abnormal gait pattern or chronic deformity, and orthotic insoles suggest an attempt to correct alignment or offload a painful compartment.

With the patient still standing, inspect both knees from the front, the side and behind, always comparing one side with the other.

From the front, assess the coronal alignment of the legs. Genu varum (‘bow legs’) describes knees that bow outwards and is commonly seen in medial compartment osteoarthritis, where loss of medial cartilage collapses the joint into varus. Genu valgum (‘knock knees’) describes knees that angle inwards and is more typical of lateral compartment disease or rheumatoid arthritis.

From the side, look for genu recurvatum (hyperextension of the knee), which may reflect ligamentous laxity. From behind, inspect the popliteal fossa for any swelling, in particular a Baker’s cyst – a fluid-filled distension of the bursa behind the knee that communicates with the joint and is associated with effusions and osteoarthritis.

Throughout, look for scars (suggesting previous surgery such as arthroscopy or joint replacement), swelling, muscle wasting and redness.

Ask the patient to lie on the couch with their legs straight and re-inspect the knees up close.

Look for an effusion, seen as a loss of the normal dimples either side of the patella and a generally ‘full’ appearance to the joint. An effusion represents extra fluid within the joint – this may be synovial fluid (osteoarthritis, inflammatory arthritis), blood (a haemarthrosis following an acute ACL rupture or intra-articular fracture) or pus (septic arthritis).

Assess the quadriceps, particularly the vastus medialis, for wasting. Because the quadriceps rapidly atrophies with disuse, wasting is a useful sign of chronic knee pathology or pain that has limited activity.

Look again for scars, erythema (which may indicate infection or active inflammation) and any obvious deformity.

A quick recap of the relevant anatomy makes the special tests much easier to understand. The knee is stabilised by four key ligaments. The anterior cruciate ligament (ACL) prevents anterior translation of the tibia on the femur. The posterior cruciate ligament (PCL) prevents posterior translation. The medial collateral ligament (MCL) resists valgus (inward-angulating) force, and the lateral (fibular) collateral ligament (LCL) resists varus (outward-angulating) force. The two menisci are C-shaped fibrocartilage discs that cushion and distribute load across the joint.

Image - Anatomy of the right knee showing the cruciate ligaments, collateral ligaments and menisci. Understanding these structures explains the logic behind each special test

Creative commons source by Mysid [Public domain]

Image - The knee joint viewed from behind, demonstrating the cruciate and collateral ligaments that the special tests are designed to isolate

Creative commons source by Henry Vandyke Carter [Public domain]

Before palpating, ask again about pain and watch the patient’s face throughout.

Using the back of your hand, assess and compare the temperature over both knees and the thigh above. An increased temperature over the joint suggests an active inflammatory or infective process such as septic arthritis, gout or a flare of inflammatory arthritis. The back of the hand is used because it is more temperature-sensitive than the palm.

Measure and compare quadriceps bulk by measuring the thigh circumference a fixed distance (e.g. 15 cm) above the tibial tuberosity on each side; a measurable difference confirms quadriceps wasting.

With the knee extended, palpate systematically for tenderness over the borders of the patella, the quadriceps and patellar tendons, the tibial tuberosity and the joint lines. Joint-line tenderness is an important sign of meniscal injury or osteoarthritis. Tenderness at the tibial tuberosity in an adolescent suggests Osgood–Schlatter disease.

Then flex the knee to 90° and palpate the joint lines again, along with the collateral ligaments, the head of the fibula and the popliteal fossa. A soft swelling in the popliteal fossa supports a Baker’s cyst.

Preview the Knee OSCE Examination quiz