Management of Knee Pain After Total Knee Replacement

Initial Evaluation

Plain radiographs (X-rays) of the knee should be obtained first in all patients with pain after total knee arthroplasty (TKA) to assess component positioning, alignment, and potential complications, as recommended by the American College of Radiology 1, 3
Joint aspiration should be performed after reviewing the X-ray if infection is suspected, as this is the most serious complication of TKA (occurring in 0.8-1.9% of cases), according to the American College of Radiology 4
Clinical assessment should focus on differentiating between common causes of post-TKA pain, including infection (may present with night pain, pain at rest, warmth, erythema) and aseptic loosening (typically pain on weight bearing), as suggested by the American College of Radiology 5
Periprosthetic fracture is another potential cause of post-TKA pain, and CT without IV contrast is recommended for definitive evaluation, as per the American College of Radiology 3

When infection is suspected, obtain knee radiographs followed by joint aspiration for cell count, culture, and sensitivity, and proceed to surgical management as per AAOS guidelines if aspiration cultures are positive for infection 4, 7
When aseptic loosening is suspected, obtain CT of the knee without IV contrast, and consider fluoroscopy or Tc-99m 3-phase bone scan to evaluate for loosening, as recommended by the American College of Radiology 9
When component rotation issues are suspected, CT scan without IV contrast is the imaging modality of choice, and MRI without contrast may be considered as an alternative, according to the American College of Radiology 6

For asymptomatic patients with TKA, routine follow-up with knee radiographs is appropriate, as recommended by the American College of Radiology 1
For patients with persistent pain despite initial management, consider referral back to the orthopedic surgeon for further evaluation, as suggested by the American College of Radiology 7
Annual weight-bearing radiographs are recommended for detecting subclinical wear in the prosthesis, as per the American College of Radiology 5