Arthrofibrosis of Knee
Conditions
Keywords
arthrofibrosis, stiffness, revision knee, low dose irradiation, hinged knee prosthesis
Brief summary
Acquired idiopathic stiffness (AIS) is a common complication following total knee arthroplasty (TKA). It is caused by excessive scar formation, which leads to pain, loss of motion, and functional impairment. When early noninvasive treatments fail, some patients require more surgery. In these cases, surgeons often use a special type of replacement called a hinged prosthesis, which allows more thorough removal of scar tissue and stiffened ligaments. Unfortunately, even after more surgery, many patients continue to struggle with stiffness, pain, and impaired function. Low-dose irradiation (LDI) is a safe, established therapy for conditions with abnormal scar formation. Its role in the setting of AIS has not been defined. The goal of this study is to compare outcomes of revision TKA with or without the addition of LDI. The primary outcome is range of motion at one year following surgery. Secondary outcomes include patient-reported functional scores, repeat surgeries, and complications like wound breakdown or infection. This project has the potential to address a common, debilitating complication after TKA, improve outcomes, reduce repeat interventions and healthcare costs, and broader implementation and standardization of care.
Detailed description
Acquired idiopathic stiffness (AIS), or arthrofibrosis, is a rare but potentially devastating complication after total knee arthroplasty (TKA), occurring in approximately 1-6% of cases. It is characterized by pathological fibroblast and myofibroblast proliferation leading to excessive scar tissue deposition within and around the knee joint, resulting in restricted range of motion (ROM), pain, and functional impairment. When conservative management (physiotherapy, manipulation under anesthesia) fails, operative intervention is required. Full component revision to a hinged prosthesis - which permits complete synovectomy, posterior capsule release, and debridement of fibrosed collateral ligaments - has demonstrated superior ROM outcomes compared to partial revision strategies. Perioperative low-dose irradiation (LDI) has an established role in the prophylaxis of heterotopic ossification following total hip arthroplasty and is used as adjunctive therapy for keloid prevention. Mechanistically, LDI at 700-800 cGy inhibits myofibroblast proliferation and modulates fibrotic signaling pathways, addressing the underlying pathophysiology of arthrofibrosis. A retrospective review of 60 patients undergoing hinged revision TKA with LDI demonstrated a median ROM improvement of 60°, with acceptable complication rates. Despite this evidence, no prospective randomized controlled trial has compared hinged revision TKA with and without LDI.
Interventions
RADIATIONLow-Dose External Beam Irradiation
A single session of external beam irradiation (800 cGy) delivered to the operative knee on post-operative day 1 (or post-operative day 2 if medically necessary). At Mount Sinai Hospital and Humber River Hospital, LDI is delivered at Princess Margaret Cancer Centre. US sites coordinate through local radiation oncology departments.
PROCEDUREHinged Revision Total Knee Arthroplasty
Full component revision to a rotating hinge knee prosthesis, including synovectomy, posterior capsule debridement, and release of fibrosed collateral ligaments, performed by the treating orthopaedic surgeon at each participating site.
Sponsors
Mount Sinai Hospital, Canada
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adults (≥18 years) undergoing revision TKA with a hinged prosthesis for AIS after primary TKA * Patient with a ROM arc \<70 degrees or flexion contracture of \>20 degrees without any identifiable cause for stiffness (e.g. component oversizing, malrotation, infection, or periprosthetic fracture).
Exclusion criteria
* Revision for causes other than AIS (e.g., component malposition, infection, periprosthetic fracture) * Prior ipsilateral knee infection * Revision to non-hinged prosthesis * Medical contraindications to surgery * Medical contraindications to irradiation * Currently pregnant or planning to become pregnant during the study period
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total arc of knee range of motion (ROM) | Baseline (pre-operative), intraoperative, 2 weeks, 6 weeks, 3 months, and1 year post-operatively. | Goniometric measurement of total arc of motion (flexion minus extension deficit) performed by treating surgeon at each follow-up visit, per standard clinical protocol. |
Secondary
| Measure | Time frame |
|---|---|
| Medical complications | 2 weeks, 6 weeks, 3 months, 1 year |
| Oxford Knee Score (OKS) | Pre-op, 2 weeks, 6 weeks, 3 months, 1 year |
| EQ-5D-5L (health-related quality of life) | Pre-op, 2 weeks, 6 weeks, 3 months, 1 year |
| Visual Analogue Scale (VAS) - Pain | Pre-op, 2 weeks, 6 weeks, 3 months, 1 year |
| Patient Satisfaction (numeric rating) | 6 weeks, 3 months, 1 year |
| Wound complications (requiring intervention) | 2 weeks, 6 weeks, 3 months, 1 year |
| Reoperation Rate | 2 weeks, 6 weeks, 3 months, 1 year |
| Infection rate | 2 weeks, 6 weeks, 3 months, 1 year |
Countries
Canada, United States
Contacts
CONTACTJesse Wolfstadt, MD, MSc
CONTACTRavianne Tuazon, BSc
PRINCIPAL_INVESTIGATORJesse Wolfstadt, MD, MSc
MOUNT SINAI HOSPITAL
Outcome results
None listed