Fibrosis is a common outcome following total knee arthroplasty

Abstract

Total knee arthroplasty (TKA) is one of the most successful orthopaedic procedures that alleviates pain and restores function in patients with degenerative knee joint diseases. Arthrofibrosis, abnormal scarring in which dense fibrous tissue prevents normal range of motion, develops in ~3–10% of TKA patients. No prophylactic intervention is available and treatment is restricted to aggressive physiotherapy or revision surgery. Tissue was collected from patients undergoing primary (n = 30) or revision (n = 27) TKA. Revision patients were stratified as non-arthrofibrotic and arthrofibrotic. Tissue was macroscopically and histologically compared to improve our understanding of the pathophysiology of arthrofibrosis. Macroscopically, tissue from primary TKA presents as homogenous, fatty tissue whereas tissue from revision TKA presents as dense, pigmented tissue. Histologically, there was dramatic tissue remodelling, increased collagen deposition and increased (myo)fibroblast staining in tissue from revision TKA. Significantly, tissue architecture was similar between revision patients regardless of clinically diagnosis. There are significant differences in architecture and composition of tissue from revision TKA over primary TKA. Surprisingly, whether revision TKA were clinically diagnosed as arthrofibrotic or non-arthrofibrotic there were still significant differences in fibrotic markers compared to primary TKA suggesting an ongoing fibrotic process in all revision knees.

Chronic, Active Inflammation in Patients With Failed Total Knee Replacements Undergoing Revision Surgery

“…Stiffness and joint fibrosis is a significant problem following TKA. We have previously shown that fibrotic, dense collagenous scar tissue is found in all patients undergoing aseptic revision surgery for failed primary TKA . The fibrotic tissue is characterized by the deposition of a dense, disorganized extracellular matrix of collagen populated by myofibroblasts .…”

“…Data presented in this report suggest that the levels of key biologically active pro‐inflammatory mediators are locally elevated at time of revision surgery many years after the initial procedure in failed TKAs. The painful, fibrotic post‐TKA joint acquires a state of unresolved inflammation with a signature resembling that of a chronic allergic reaction . Markers with this temporal regulation include those involved in matrix formation (VEGF, Flt‐1) and the inflammatory cytokines GM‐CSF, IL‐5 and IL‐8, and cell recruitment chemokines CCL2, CCL3 and CCL4.…”

“…We and others have previously shown that the post‐TKA joint is associated with the persistence of myofibroblasts and extensive fibrotic remodeling . More recently, we have investigated the expression of 39 soluble inflammatory proteins in SF, fat pad (FP), and synovial membrane (SM) from patients undergoing either primary or revision surgery .…”

Increased symptoms of stiffness 1 year after total knee arthroplasty are associated with a worse functional outcome and lower rate of patient satisfaction

“…There are multiple post-operative interventions suggested to prevent stiffness from occurring [6]. However, with greater understanding of fibrosis pathways there may be inhibitors that may stop the post-operative stiffness from developing [1], which may improve the patients functional outcome and satisfaction.…”

Sulfasalazine Resolves Joint Stiffness in a Rabbit Model of Arthrofibrosis

“…Fibrosis often develops after joint trauma or major surgical procedures such as total knee arthroplasty (TKA) and anterior cruciate ligament (ACL) reconstruction . Approximately, 3–10% of TKA patients are treated for arthrofibrosis, while 2–35% of ACL reconstruction patients and 14.5% of patients with knee intra‐articular fractures require intervention . The standard‐of‐care is limited to arthroscopic debridement, capsule‐release, and manipulating limbs under anesthesia.…”