Question
A 65 year old woman can only flex her knee to 70 degrees 10 weeks after a total knee arthroplasty.
- What are the causes of stiffness after knee replacement?
- How would you assess her?
- What are the treatment options?
Answer
Causes
- Poor preoperative range of motion, the strongest predictor
- Pain, poor rehabilitation and complex regional pain syndrome
- Arthrofibrosis
- Technical errors such as overstuffing the patellofemoral joint, a tight flexion gap, raised joint line, malrotation and inadequate posterior osteophyte removal
- Infection must always be excluded
- Heterotopic ossification
Assessment
- Pain history, timing and rehabilitation progress
- Examination for effusion, patellar tracking and flexion contracture
- Radiographs for component size, position, joint line and patellar height
- CT for component rotation
- CRP, ESR and aspiration to exclude infection
Treatment options
- Intensive physiotherapy and analgesia
- Manipulation under anaesthesia within about 12 weeks of surgery, with care to avoid fracture and extensor mechanism injury
- Arthroscopic or open arthrolysis after 3 months
- Revision when a technical cause is found, as results are poor without a clear cause
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.