Manipulation under anaesthesia (MUA) of the knee is a procedure to break down scar tissue (adhesions) inside a stiff knee joint, restoring range of motion. It is performed when physiotherapy alone has not achieved adequate movement after knee surgery.
Under general or spinal anaesthesia, the surgeon gently but firmly flexes and extends the knee through its full range, breaking the adhesions that are restricting movement. An audible and palpable release is usually felt. The entire procedure takes 10–15 minutes. Arthroscopic lysis of adhesions may be performed at the same time if needed.
MUA is recommended when knee flexion is inadequate (typically less than 90 degrees) at six to twelve weeks after total knee replacement, ACL reconstruction, or other knee surgery, despite dedicated physiotherapy. The timing is important — too early risks damaging healing structures, too late allows adhesions to mature.
Intensive physiotherapy, serial splinting (static progressive or dynamic), and time. Many stiff knees improve with persistent rehabilitation.
Day-case procedure. Assessment of current range of motion. X-ray to confirm implant position if post-arthroplasty.
Immediate improvement in range of motion. Most patients gain 20–40 degrees of additional flexion. The gains must be maintained with intensive physiotherapy in the following weeks.
Significant soreness and swelling for several days after manipulation.
Adhesions may reform if physiotherapy is not maintained. Risk approximately 10–20%.
Bleeding into the joint from torn adhesions.
Supracondylar femur or proximal tibia fracture, particularly in osteoporotic bone. Risk approximately 1%.
Very rare. Risk is higher with excessive force.
If performed too early after surgery, the wound may open.
Extremely rare.
Theoretical risk with excessive force around an implant.
General or spinal anaesthesia with muscle relaxation. The knee must be fully relaxed to allow safe manipulation.
Intensive physiotherapy begins immediately — ideally while the anaesthetic is still providing pain relief. CPM machine may be used. Daily exercises at home. Ice and elevation for swelling. The first two weeks after manipulation are critical for maintaining the gained range.
Physiotherapy from day one. Surgeon review at two weeks and six weeks.
Usually between six and twelve weeks after surgery. Earlier risks disrupting healing; later allows adhesions to mature and become resistant to manipulation.
Most patients gain significant range of motion. However, some knees are resistant, particularly if the stiffness is caused by complex regional pain syndrome or severe arthrofibrosis. Arthroscopic release may be needed.