Knee Osteoarthritis (KOA) is a common chronic disease, which often leads to joint pain
and limited function in the elderly, and thus affects participants' quality of life.
Total knee arthroplasty (TKA) has been developed as a mature surgical procedure to
relieve end-stage osteoarthritic joint pain and improve limb function. Although more than
80% of the patients reported in the literature are satisfied with the postoperative
efficacy of TKA, there are still a large number of patients whose daily life is affected
by persistent knee pain and limited function after the operation of the affected limb.
The IPFP is a fat mass located behind the patellar ligament, between the lower part of
the patella and the tibial tubercle. The function of IPFP is controversial at present. It
is reported that IPFP can provide blood supply for anterior cruciate ligament, patella
and patellar ligament through the arterial network of the knee joint. In addition, it can
fill the joint gap to lubricate the surface of the joint, reduce friction and absorb
impulse so as to play a physiological protective role. On the contrary, studies have
pointed out that abnormal IPFP could produce various pro-inflammatory cytokines such as
interleukin (IL)-1β, tumour necrosis factor (TNF)-α, IL-6 and IL-8, as well as adipokines
such as leptin and resistin, and thus might play a detrimental role in knee OA.
Traditionally, the IPFP has been removed in order to improve surgical exposure and to
prevent interposition during baseplate implantation. Despite the significant evolution of
TKA technology which no longer requires the resection of IPFP for better surgical access,
IPFP is still partially or totally resected in around 88% of TKAs.
The investigators' previous population-based cohort study revealed that IPFP maximal area
and volume were associated with reduced knee pain, decreased loss of cartilage volume and
reduced risks of cartilage defect progression, indicating a beneficial effect of IPFP
size. On the other hand, the investigators' further investigation demonstrated that IPFP
signal intensity alteration was negatively associated with maximum area of IPFP, and
moreover, associated with increased knee cartilage defects, subchondral bone marrow
lesion (BML) and knee pain, suggesting IPFP with abnormal quality may play a detrimental
role in knee OA. Based on these findings, the investigators proposed that IPFP with
normal quality should be preserved or not damaged during TKA, while IPFP with abnormal
quality should be resected. This multicentre randomised controlled trial is designed to
test the investigators' hypotheses: in patients with normal IPFP quality, preservation of
IPFP during TKA procedure will reduce postoperative knee symptoms and improve joint
function, comparing with IPFP resection during TKA procedures; in patients with abnormal
IPFP quality, resection of IPFP during TKA procedure will reduce postoperative knee
symptoms and improve joint function, comparing with IPFP preservation during TKA
procedures. The results would provide evidence-based recommendations on clinical practice
to improve OA patients' postoperative outcomes.
Three hundred and sixty eligible participants will be recruited and identified as having
normal IPFP quality (signal intensity alteration score ≤ 1) or abnormal IPFP quality
(signal intensity alteration score ≥ 2). Participants in each site will be randomly
allocated to IPFP resection group or preservation group using computer-generated block
randomisation.
