From the Guidelines
Crepitance in a knee replacement after 1 year is most likely caused by aseptic loosening or osteolysis, which can occur due to mechanical stresses, particle debris, or poor bone stock. This is supported by a recent study published in the Journal of the American College of Radiology in 2023 1, which highlights the importance of considering loosening as a potential cause of knee pain and periprosthetic lucency after total knee arthroplasty. The study notes that aseptic loosening is a common cause of TKA failure, and osteolysis is a leading cause of late TKA revision.
Some key factors that contribute to crepitance in knee replacement include:
- Mechanical stresses on the implant
- Particle debris from polyethylene, cement, or metal components
- Poor bone stock
- Osteolysis, also known as particle disease or aggressive granulomatosis
- Instability, which can occur due to surgical error, poor prosthesis selection, or ligamentous imbalance
It is essential to note that crepitance can be a symptom of an underlying issue that requires prompt attention. If you are experiencing crepitance in your knee replacement, it is crucial to consult your orthopedic surgeon for a thorough evaluation, which may include physical examination, imaging studies, and blood tests to determine the exact cause and appropriate treatment 1.
From the Research
Causes of Crepitance in Knee Replacement
- Crepitance in a knee replacement after 1 year can be caused by several factors, including peripatellar fibrosynovial hyperplasia, implant design, and previous knee surgery 2.
- The incidence of patellofemoral crepitus and clunk syndrome after total knee arthroplasty has been reported to be 0%-18% 2.
- Femoral component designs with a high intercondylar box ratio, reduced patellar tendon length, thinner patellar components, and smaller femoral components have been proposed as potential etiologies for crepitance 2.
Prevention and Treatment
- Preventative measures for crepitance include choosing femoral components with a reduced intercondylar box ratio, using thicker patellar components, avoiding over-resection of the patella, and debridement of the fibrosynovial tissue at the time of knee arthroplasty 2.
- Arthroscopic debridement of the fibrosynovial hyperplasia is a effective treatment option for patients with significant symptoms, with high patient satisfaction and low recurrence rates 3.
- Arthroscopic excision of the supra-patellar lesion has been shown to be an effective treatment option for painful patellar clunk and crepitance, with 79% of patients reporting being extremely satisfied or very satisfied with the outcome 3.
Association with Implant Design
- Posterior-stabilized designs have been associated with a higher incidence of patellofemoral crepitus and clunk syndrome 3, 4.
- The Sigma PS design has been shown to have a relatively low incidence of crepitance requiring arthroscopic excision, at 1.2% of patients 3.
- Resurfacing of the patella has been shown to have a significant impact on the incidence of post-operative patellofemoral pain, clunk, and crepitus, with a higher incidence of post-op clunk in patients with pre-op patellofemoral pain who underwent resurfacing 5.