Arthrofibrosis after Knee Replacement – Revision Knee Replacement (Revision Arthroplasty):
Revision knee replacement (revision knee arthroplasty) is the last resort in treating arthrofibrosis. Revision is considered in patients with long standing, severe arthrofibrosis (chronic severe arthrofibrosis) and in patients who failed to improve with (resistant arthrofibrosis) or redeveloped arthrofibrosis (recurrent arthrofibrosis) following other treatment approaches like prolonged physical therapy, manipulation under anesthesia, arthroscopic lysis of adhesions or open lysis of adhesions.
Revision knee replacement is usually performed 1 year after the initial knee replacement. Revision knee replacement could be considered after 6 months and better outcomes are reported if it is done within 2 years.
In this procedure, the existing knee replacement prosthetic components are removed and replaced with with new prosthetic components.
1. Preoperative Evaluation:
In addition to arthrofibrosis and heterotopic ossification of the knee, stiffness following knee replacement can arise from many other causes. Before making a diagnosis of arthrofibrosis, the knee has to be thoroughly evaluated by an arthrofibrosis specialist experienced in “arthrofibrosis following knee replacement” to find out the exact cause of stiffness following knee replacement. As the first step, low-grade infection as well as painful knee conditions causing muscle spasm should be excluded. Following this, all other possible causes of knee stiffness following knee replacement have to be excluded. After excluding all the possible causes of stiffness following total knee replacement, the diagnosis of arthrofibrosis is considered. Arthrofibrosis may also coexist with other causes of stiffness. Once a specific diagnosis is made, the treatment is planned.
2. Revision Knee Replacement for Arthrofibrosis:
Revision knee replacement for arthrofibrosis is complex and is technically demanding. The goals of revision surgery in arthrofibrosis are to improve flexion contracture, range of flexion, arc of motion, pain, functional outcome and patient satisfaction. This is achieved by various combinations of different surgical steps depending on the specific circumstance in each patient. The surgical steps could be categorized into the following categories.
(A). Soft Tissue Releases / Lengthening:
The scarred soft tissues are released / lengthened as needed to improve motion. The literature regarding the extent of soft tissue release is controversial. Some authors consider “limited soft tissue release” for the fear of further scar tissue formation in response to surgery. Others suggest “radical soft tissue release” with the goal of improving the range of motion.
(B). Removal of Arthrofibrosis Scar Tissue and Heterotopic Ossification:
The scar tissue and heterotopic ossification that obstruct restoration of the knee motion is removed. Again, the literature regarding the extent of lysis of adhesions and removal of the newly formed bone is controversial. Some authors consider “limited arthrolysis” for the fear of further scar tissue formation in response to surgery. Others suggest “radical arthrolysis” with the goal of improving the range of motion.
(C). Additional Bone Resection:
Additional bone could be resected to improve motion depending on individual circumstances to improve flexion contracture and range of flexion.
(D). Revision of Knee Prosthesis:
Different partial as well as complete revision procedures have been described by various authors for arthrofibrosis. Also the use of prosthesis with different level of constraint (freedom of prosthetic motion) have been described. A prosthesis with higher level of constraint may be necessary to maintain the stability of the knee. A prosthesis of the same size as the removed one or a smaller size (component downsizing) is used depending on specific circumstance in each knee.
(E). Treating Identifiable Cause of Stiffness:
If a co-existent “identifiable cause of stiffness” following knee replacement is found in addition to arthrofibrosis, the specific cause is also addressed appropriately.
3. Postoperative Management:
The main objective of postoperative management after revision knee replacement for arthrofibrosis is prevention of recurrence of arthrofibrosis. This is achieved by the following measures.
1. There are published articles in the literature regarding the use of postoperative or preoperative irradiation to the knee with the hops of preventing the recurrence of scarring, arthrofibrosis and heterotopic ossification.
2. Postoperative physical therapy is prescribed immediately after the surgery on the same day or the next morning. The therapy is focused on improving the extension as well as flexion. Mechanical devices like flexionator / extensionator are useful. Some authors prefer CPM (continuous passive motion).
3. If the flexion and extension do not improve progressively as expected over time, manipulation under anesthesia (MUA) is utilized. MUA can be repeated as needed. Patients may need serial manipulation and casting. Splints or braces can also be used as needed.
4. There is no adequate evidence in the published medical literature to consider arthroscopic lysis of adhesions or open lysis of adhesions after revision knee replacement.
5. If the patient develops stiffness again despite all these measures, a second revision knee replacement can be considered but the results are not as good as the first revision.