Page 3 - Orthofeed_Issue4_Feb2022

ORTHOFEED, Edition 4 02

Clinical evaluation of instability reported to occur in 70% to 85% of patients

Clinical assessment of patients should be with flexion instability. 6
comprehensive and not just limited to the knee. 3
2) The range of motion should be noted as this

1 Examination of all deformities varies significantly between the types of
at the ankle or hip instability encountered.
6
A knee which fails to fully extend may occur
2
Note the range of motion secondary to a tight extension gap. This can

ultimately lead to a flexion contracture of the
3 Thorough assessment of TKR. 6
patellofemoral tracking
If there is any laxity in extension, it may

4 Diagnostic tests produce recurvatum. 6
Tightness in flexion will limit the amount of
deep flexion achieved if any. 6

1) The examination should take into account all 3) A thorough assessment of patellofemoral

deformities at the ankle or hip which may affect tracking should be performed. A routine
overall limb alignment. 5 varus–valgus stress test at full extension, 30°,

The fluidity of the gait pattern may indicate 45° to 60°, and 90° of flexion assists in
any varus or valgus thrust (present in identifying the condition of the surrounding knee

asymmetric extension instability). 6 stabilisers. 3

Malrotation of the femoral component may 4) Diagnostic studies help to assess anatomical
manifest in an abnormal foot progression alignment, presence of malrotation, osteolysis,

angle during gait and patellar mal-tracking. and loosening and residual bone stock. The
7
This may create an asymmetric, tests include:

trapezoidal-shaped flexion gap and flexion
instability. 6

The knee should be systematically palpated Weight-bearing anterior posterior, lateral and
skyline knee radiographs
for evidence of localised tenderness (e.g. pes
anserinus tendonitis and/or iliotibial band
Full-length coronal and sagittal radiographs
(ITB) tendonitis, which can occur in flexion
instability). 6
Computed tomography (CT)

Patients may also present with a

serosanguinous effusion. This has been