Stiffness after total knee replacement is difficult for patients and greatly affects their quality of life. With improved surgical techniques and aggressive rehabilitation following surgery, however, the incidence of stiffness after total knee arthroplasty (TKA) is uncommon, with an incidence of 8% to 12%.

The greatest risk factor for postoperative knee stiffness is poor preoperative motion. Knee stiffness can generally be defined as flexion contracture >10- to 15-degrees and flexion <90 degrees. Activities of daily living require a certain level of motion, including 67 degrees of flexion for gait, 80 to 100 degrees of flexion to climb up and down stairs, and 105 degrees of flexion to rise from a chair.1

Arthrofibrosis is defined as excessive scar tissue that occurs as a result of a surgical procedure (TKA in this patient). The scar tissue leads to painful restriction in the patient’s range of motion. This man has very limited flexion at 70 degrees despite physical therapy for 6 weeks postoperatively. The best recommendation for this patient is manipulation under anesthesia.

There is no consensus on timing and degree of motion or stiffness for a manipulation. However, manipulation at 6 weeks is common if patients are not able to achieve >75 degrees of flexion. Manipulation involves flexing and extending the knee firmly and progressively until tearing of adhesions can no longer be heard or a firm end point is felt.

Patients with knee stiffness after TKA have better outcomes if the manipulation is performed within 3 months of surgery, and therefore, continuing physical therapy in this patient would not be recommended. An intra-articular injection should be avoided as it would increase the risk for periprosthetic infection. Arthroscopic debridement of adhesions with manipulation has not shown improved outcomes over manipulation alone for early stiffness after TKA and is not performed routinely. Those with late stiffness (>3 months after surgery) may be considered for arthroscopic lysis of adhesions with manipulation.1,2

Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA). 


  1. Bong MR, Cesare PE. Stiffness after total knee arthroplasty. J Am Acad Orthop Surg. 2004;12:164-171.
  2. Karadsheh M. TKA Stiffness. Updated May 14, 2016. Accessed September 12, 2016.
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