The leading causes of sterile arthrofibrosis are injury and surgery
Unfortunately, surgery is frequently the initiating event that leads to arthrofibrosis . We therefore have a cautionary approach to surgery (and manipulation under anaesthesia) as a treatment for arthrofibrosis, and believe that it should not be the first treatment approach. Surgery and MUA always involve some bleeding, hypoxia, inflammation and wound healing, and all of these are powerful fibrotic stimuli. These procedures therefore carry the real risk of permanently worsening symptoms due to the reactivation of wound healing processes and inflammation .
Nonetheless, arthroscopic lysis of scar tissue can reduce the symptoms of restricted range of motion and pain, allowing better quality of life , but there are currently no methods for determining who will benefit. Minimally invasive, shorter duration surgical procedures with good control of bleeding and pain carry less risk compared to open procedures, but there is significant physical stress with any surgery . In our opinion it is important to choose a careful surgeon who is experienced in operating on fibrotic joints and who understands the pathology of arthrofibrosis.
A revision total knee replacement (TKR), often using a rotating hinge prosthesis, is the standard surgical approach for treating TKR problems; however, revisions are associated with significantly increased risks compared to the first TKR  with only a 60 % survival rate at 8 years post operation. In our opinion a revision TKR should not be performed unless there are significant and clearly identifiable problems with the original TKR that must be corrected. From a common sense perspective, repeating the surgery that caused the problem is unlikely to help, even if the type of prosthesis used is different.
The practices of an experienced arthrofibrosis surgeon are:
No use of a tourniquet during surgery unless absolutely necessary. Hypoxia (lack of oxygen) is a powerful driver of fibrosis and the use of a tourniquet (or not) during surgery as standard practice is likely to be an important difference between surgeons. However, a tourniquet may sometimes be necessary, for example, during a TKR.
“Releasing” scar tissue not “removing” it with very little use of the arthroscopic shaver, preferring the use of a cautery tool to release scar tissue and prevent bleeding.
Preserving the fat pad. Cutting the fat pad strongly promotes further fibrosis.
Liberal use of local pain anaesthetics to ensure adequate post-op pain control.
The following is an example procedure by an experienced arthrofibrosis surgeon. Indwelling local pain catheters were placed pre-op by the anaesthesiologist under ultrasound guidance for a continuous ropivacaine infusion that was taken home and controlled by a button press, lasting for 3 days (when pain is usually at its worst). One was an adductor canal block and the other a sciatic block. In addition, a genicular local block was placed during surgery that theoretically lasts 24 hours. Not recommended are femoral nerve blocks (a one-time shot) placed pre-op since these have the disadvantage of causing some motor blockade / quad weakness, and they also only last about 1 day, leaving days 2 and 3 painful. The adductor canal block and genicular/sciatic block only block sensory nerves, sparing the motor function of the quads.
The following information is from a nurse practitioner:
“Having worked with many different surgeons in the operating room I can attest that there is a wide variety of operative styles. Even though the operative report might read nearly identical between doctors, their hand movements, how they handle tissues and with what, how much attention they pay to hemostasis (control of bleeding) as they go, how much “extra” stuff they do, how fast they are, where they put their incisions, whether they close certain layers individually, whether they sprinkle antibiotic powder, do interrupted or running sutures, what instrument they use for dissecting, what local/anaesthesia is used, if any, what materials they use for suturing or implants, whether they preserve the fat pad or not during a primary total knee replacement, etc, etc.”
For somebody who is borderline (has genetics that don’t strongly predispose them to arthrofibrosis), one very small mistake (e.g. exercising too much) or unavoidable factor (e.g. the flu) can push them over the edge towards fibrosis, or they may escape it. However, if a person has strong genetic drivers then it may be difficult or impossible to avoid arthrofibrosis after surgery.
Usher, K. M. et al. Pathological mechanisms and therapeutic outlooks for arthrofibrosis. Bone Research 7, doi:10.1038/s41413-019-0047-x (2019).
Dobson, G. P. Trauma of major surgery: A global problem that is not going away. Int J Surg 81, 47-54, doi:10.1016/j.ijsu.2020.07.017 (2020).
Neuhaus, H. J. & Maier, K. Rotating Hinge Prosthesis for Primary and Revision Knee Arthroplasty: Comparison and Indications. Biomed Res Int 2022, 9930675, doi:10.1155/2022/9930675 (2022).
The materials presented in this site are provided voluntarily as a public service. It is of a general nature, based on the scientific literature. The information and advice provided is made available in good faith but is provided solely on the basis that readers will be responsible for managing their own assessment of the matters discussed herein and that they should verify all relevant representations, statements and information. Please consult your doctor.