Knee replacement surgery is generally very safe and effective, but it is a major operation. For unknown reasons, scar tissue formation within the knee joint may be excessive in some patients (a condition known as athrofibrosis). This can result in joint pain and stiffness and reduced range of motion (ROM).
This stiffness is sometimes addressed by a forcible, closed manipulation of the knee joint by an orthopedic surgeon. In a recent study in the journal Orthopedics, the authors looked at the effectiveness of manipulation and sought to determine if any patient factors could be used to predict range of motion improvements following this procedure.
In this study the authors describe how manipulation following knee replacement is performed. Patients are given either epidural or general anesthesia. An assistant holds the heel while the surgeon gently extends or straightens the leg.
While straitening the leg, the surgeon applies pressure to the anterior (front) of the knee joint. The knee is then flexed or bent with the assistant holding the thigh while the surgeon applies pressure with his chest on the anterior of the tibial (shin) area to, as they say “allow slow, steady stretching and tearing of the intra-articular scar tissue” (“intra-articular” means within the joint).
This process is repeated until full Range of motion is achieved or until the surgeon “no longer feels creptiation” (crepitation is the dry, crackling sound or sensation resulting from rubbing bones or irregular cartilage surfaces together as in arthritis).
Some interesting findings and observations from this study:
- The surgeons looked at a consecutive series of 767 patients. Forty-six required manipulation. So this condition was observed in 6% of patients.
- On average, patient’s ROM increased significantly after manipulation. Patients were able to bend or flex their knee 22 degrees further, and extend or straighten their knee 4 degrees more.
- The flexion achieved after manipulation was similar to that which the patient had before having knee replacement. (Pre-operative ROM is often a predictor of post-op ROM).
- Several patient factors were not associated with the effectiveness of manipulation. These included patient sex, BMI and alignment of the knee joint before surgery (i.e. the amount of knock-kneed (valgus) or bow-legged (varus) deformity).
- The authors used several different types of implants. Implant design or type did not influence the effectiveness of manipulation.
- Patients manipulated less that 8 weeks after surgery gained more flexion than those manipulated after 8 weeks following their knee replacement.
- The patients were followed for 1 year, and those whom had full extension before manipulation wound up with more flexion at 1 year post-op.
- To avoid the need for manipulation (and presumably the formation of excessive, debilitating scar tissue), the authors suggest aggressive pain management for the first few days after surgery followed by ambulation and some exercise.
This study can be found in the June 2009 issue of Orthopedics.
1.Cates HE, Schmidt, JM. Closed Manipulation after Total Knee Arthroplasty: Outcome and Affecting Variables. Orthopedics. 2009; 32:398.
2.Arthritis of the Knee Joint. Complications of Knee Replacement Surgery. http://www.hipsandknees.com/knee/kneesurgerycomplications.htm#scar. 28-Feb-10