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Part II of III

Total knee replacement surgery or total knee arthroplasty (TKA) is one of the most commonly performed orthopedic surgeries in the U.S. for individuals older than 40. Given historical trends, these procedures are anticipated to increase in volume by an estimated 143% by 2050.

In part 2, we examine contributing factors that might predispose a patient to an increased likelihood of excessive scar tissue formation after surgery which may lead to a manipulation under anesthesia (MUA) as discussed last week in this column. Along with muscle weakness due to disuse and immobility, scar tissue formation is thought to be a major cause of persistent pain and limited functionality after TKA. We will also consider some risk-reducing strategies.

Scar tissue is described as excessive collagen production and adhesions. Causing contractions in the joint that limits movement and is associated with pain and discomfort. In the knee, symptoms are intensified when walking and standing and are often more debilitating than the original condition. This negatively and severely impacts patients' well-being.

Risk Factors for Scar Tissue Formation

Numerous potential factors have been studied. Still, no clear consensus is reached on which factors increase the likelihood of excessive scar tissue formation after surgery. Some studies indicate that being female or younger in age might suggest a stronger immune response leading to increased scar tissue formation. Similarly, but inconclusively, early-onset osteoarthritis might be a risk factor. A higher body mass index (BMI), previous knee surgery, diabetes, pulmonary disease, depression all have been evaluated to differing degrees, none showing clear causation.

Risk-Reducing Strategies

Surgery outcomes are multifactorial and individual. But, an appropriate risk-reduction strategy is progressive range of motion and strengthening exercises through physical therapy (PT). Physical therapy should ideally be initiated before surgery and continued after surgery to aid better outcomes. This approach is shown to reduce the incidence of additional interventions needed to release scar tissue adhesions, like manipulation under anesthesia (MUA/ Article-1).

Why Start PT Before Surgery

It is important to get a head start on PT. The rationale is that the pre-surgery range of motion and strengthening of the joint is predictive of the final outcome. It also allows you to establish a relationship with your PT healthcare team and understand what the path ahead requires. It helps you set-up your support group and will increase your odds of success. About 25% of patients will fear using the joint after surgery; having established your PT relationship, discussed, and tried out your exercise program beforehand greatly reduces this risk of post-operative complications.

What to Expect From PT

Outpatient physical therapy should be highly individualized and needs to be performed in a clinic under the supervision of a licensed physical therapist, preferably one who specializes in orthopedics. Your program will include strengthening, stretching, and functional exercises with the incorporation of balance training. Stretching and movement allow the range of motion to be increased and helps prevent scar tissue formation. Strengthening addresses the concern of quadriceps' weakening in the first weeks after surgery. Quadriceps strength is a strong predictor of functional performance. Balance training is important to reduce the risk of falls and further injury. Complimentary to outpatient PT is a home program or telerehabilitation, which requires the patient to carry-over their PT program on the days not receiving formal PT or in the case of illness or inclement weather. Hard work, dedication, and compliance are a vital to prevent complications and produce good outcomes.

Final Thoughts

An estimated 82 - 89 percent of first time TKA patients are satisfied with their outcomes. This data suggests that several patients are not achieving their goal of relieving pain and restoring functionality. It is important to establish clear and realistic expectations for your individual outcome. This requires frank and open discussion with your healthcare team, allowing you to be an empowered participant in regaining your best joint functionality. Most patients attain satisfactory recovery in 4-6 months; however, full recovery from total knee replacement surgery can take up to two years for some. The best long-term results are found in those initiating PT for range of motion and strengthening before surgery and continued immediately after surgery. 

This column is a monthly feature of “Health & Exercise Forum” in association with the students and faculty of Geisinger Commonwealth School of Medicine.

Author: Hendrik Marais, MD, MS

Hendrik Marais, MD, MS, received his Doctor of Medicine degree from Geisinger Commonwealth School of Medicine in 2015 and his Master of Science degree in Global Medicine from Keck School of Medicine at USC in 2019. He is passionate about creating positive and empowered patient health outcomes. He grew up in South Africa and currently calls Scranton, PA home – where he enjoys cycling, swimming, and discovering the beauty of NEPA. He is a member of the American Medical Association, American Public Health Association, and the International Society of Physical and Rehabilitation Medicine. He plans to pursue a clinical career in physiatry.

NEXT MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum!” Read Part III of III on Recovery from Knee Surgery “Prehab.”

This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email: drpmackarey@msn.com

Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at Geisinger Commonwealth School of Medicine.

Part I of III

Total knee replacement surgery is one of the most commonly performed orthopedic surgeries in the U.S. for individuals older than 40. Given historical trends, these procedures are anticipated to increase in volume by an estimated 143% by 2050.

Knee replacement surgery is widely considered a safe and effective surgical option for patients with end-stage osteoarthritis or inflammatory arthritis of the knee. The surgery aims to maximize the quality of life for patients by reducing pain and improving joint functionality. Unfortunately, research estimates between 1 and 10 percent of patients may experience persistent pain, limited range of motion and loss of function after surgery. This rare but devastating outcome is thought to be associated with arthrofibrosis or scar tissue build-up around the joint which ultimately has a negative impact on an individual’s daily activities and affecting emotional well-being and satisfaction. Thankfully there are remediation treatment options to consider in this situation. One non-invasive, safe, and effective possibility is manipulation under anesthesia (MUA). 

What is Manipulation Under Anesthesia (MUA)?

Manipulating the knee joint under anesthesia aims to forcefully release fibrous adhesions formed after surgery. It is considered a simple and effective medical procedure performed under general or regional anesthesia, ensuring complete muscle relaxation without any pain experienced. The procedure uses force to overcome adhesions in a controlled manner. While lying on their back, the patient's hip is flexed to a 90-degree angle, and the lower leg is used as a lever to bend the knee until a firm endpoint is reached. Force is also applied to the kneecap to free adhesions found there. These movements are repeated several times until the best range of joint motion is achieved.

A Patient's Experience: Pre-MUA

Sam, a 44-year old mother and second-grade school teacher suffers from painful osteoarthritis. She underwent knee replacement surgery for both knees. However, 3 months after her surgery, she continued to experience intractable pain, swelling, and an inability to fully bend her knee. She was using a walker to assist her and could not tolerate long periods of standing. She struggled with basic daily activities and became increasingly despondent. Clinical evaluation showed that Sam was not able to bend either knee to 90 degrees. At this point, the healthcare team suggested Sam consider the MUA procedure to release the scar tissue to help move her recovery forward.

When is the Best Time to Consider MUA?

Over time, we know that adhesive tissue tends to increase in quantity and maturity. This leads to progressively worsening pain and loss of joint mobility. Literature suggests that earlier MUA intervention provides better outcomes and is more effective. Still, there is no clear consensus on the timing, and MUA may still be effective when performed later. Because clinical improvement after replacement surgery should occur between 6-12 weeks — orthopedic practices often apply a generic 90 by 90 rule of thumb. The rule signifies the ability to bend your knee to 90 degrees within 90 days after surgery. If unable to attain the 90 by 90 goal, MUA is often recommended. This is not a hard and fast rule, and each patient is individually assessed throughout the recovery period.

Risks Associated with MUA

Not everyone will be a candidate for MUA, and there are risks involved. Since force is being applied to the joint during the procedure, there is a possibility of bone fracture. Patients with osteoporosis or any other bone-weakening illness might be cautioned against the procedure. Other risks include bleeding into the joint and wound rupture. It is also important to recognize that any procedure involving anesthesia is taxing on the body and carries additional risks. It is prudent to discuss all risks and benefits with your surgeon and healthcare team fully.

Expected MUA Outcomes

MUA intends to relieve pain and discomfort and help further increase the functional range of motion in the knee joint. Biomechanically we require a knee to flex or bend, ranging from 67 degrees for walking through to 105 degrees to rise from a low chair; and 115 degrees to squat or kneel. Immediately following the procedure, joint mobility is notably improved. Research studies have recorded an average increase in flexion of 29 degrees immediately after MUA, with continued improvements over time. Individual outcomes do vary. Current literature indicates having had two or more prior knee surgeries or injury to the joint, or a stiffer knee with less than a 70-degree bend 90 days after your replacement surgery, might yield less favorable outcomes.

A Patient's Experience: Post-MUA

Sam underwent her MUA 4 months after her initial knee replacement surgery. Physical therapy is started immediately following the MUA to ensure the best outcomes. During her initial evaluation less than 24 hours after the procedure, Sam could bend both knees by herself to 90-95 degrees, something she could not do before. Less than a month after her MUA, and with continued physical therapy, she reached a 115/120 degree bend. Sam had several risk factors; early-onset osteoarthritis, high body mass index (BMI) and previous knee surgeries. These factors complicate Sam's recovery and may have lead to her failure to attain the 90 by 90 goal. Still, she told me if given a choice again; she would make the same decision. Sam smiled and told me she no longer relies on her cane to walk, can walk up and down stairs almost normally and she is eager to start driving again.

Final Thoughts

The American poet Sheldon Silverstein wrote in his poem "Stop Thief!", "...Help me please. Someone went and stole my knees. I'd chase him down but I suspect my feet and legs just won't connect." Our knee forms such an integral part of daily life and activities— yet we seldom appreciate that it is one of our most stressed and complex joints, needing 10 muscles for movement and stability, and requires varying degrees of flexibility to get us through the day.

Next Monday, in part 2 of this article, we examine factors that might predispose a patient to scar tissue induced persistent pain and limited functionality after knee replacement surgery; and possible steps to avoid this.

This column is a monthly feature of “Health & Exercise Forum” in association with the students and faculty of Geisinger Commonwealth School of Medicine.

Author: Hendrik Marais, MD, MS

Hendrik Marais, MD, MS, received his Doctor of Medicine degree from Geisinger Commonwealth School of Medicine in 2015 and his Master of Science degree in Global Medicine from Keck School of Medicine at USC in 2019. He is passionate about creating positive and empowered patient health outcomes. He grew up in South Africa and currently calls Scranton, PA home – where he enjoys cycling, swimming, and discovering the beauty of NEPA. He is a member of the American Medical Association, American Public Health Association, and the International Society of Physical and Rehabilitation Medicine. He plans to pursue a clinical career in physiatry.

NEXT MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum!” Part II of III on Recovery From Knee Surgery

This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email: drpmackarey@msn.com

For all of Dr. Mackarey's articles visit: https://mackareyphysicaltherapy.com/forum/

Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at Geisinger Commonwealth School of Medicine.