Stiffness after Knee Replacement
If knee pain becomes more severe, disrupts daily life, or occurs alongside swelling and redness, it’s essential to seek medical advice. At Complete Orthopedics, our specialists are dedicated to treating injuries to the posterior cruciate ligament with tailored treatment plans and surgical interventions. We aim to thoroughly understand your symptoms, pinpoint the root causes, and offer the appropriate treatments or surgeries.
Our locations cover both New York City and Long Island and include affiliations with six leading hospitals, providing high-quality care for knee conditions.You can make an appointment with our orthopedic surgeons either online or by phone. Explore the reasons behind knee pain and learn when surgical intervention might be necessary.
Overview
Knee replacement surgery is a highly technical procedure which has successfully resulted in alleviation of knee pain due to a variety of reasons in patients worldwide.
The knee replacement surgery is the most common non-emergent surgery performed by orthopaedic surgeons. Complications after knee replacement surgery are rare but stiff knees remain one of the common complications after knee replacement surgery.
A human knee may normally bend from 0 degrees to 135-140 degrees. About 65 degrees of movement is needed for walking, about 90 degrees for day to day activities, about 95 degrees for navigating stairs, and about 100-105 degrees for comfortably sitting and rising from a chair.
Patients are generally discharged from the hospital after they can bend their knees to about 80 to 90 degrees and are medically stable. Patients are then advised home based exercises as well as participation in physical therapy.
X-ray showing a total knee replacement.
Stiffness after knee replacement may be graded as mild when there is inability to bend more than 90-100 degrees, moderate 70-89 or severe <70 degrees.
Similarly stiffness may be defined as inability to straighten the knee with an extension gap of 5-10 degrees or more than 20 degrees in severe cases. The knee stiffness after replacement surgery may occur due to a number of different reasons.
Causes of Stiffness After Knee Replacement
Stiffness after knee replacement can be attributed to various factors, both intrinsic and extrinsic. Intrinsic factors are those related to the patient’s own body and health condition, such as the presence of fibrosis (excessive fibrous tissue formation), the patient’s inflammatory response, and underlying health conditions like diabetes or rheumatoid arthritis. Extrinsic factors involve elements of the surgical procedure itself, including the type of prosthetic used, the accuracy of implant placement, and the surgical technique.
Preoperative Factors
- History of prior surgery of the knee has been associated with higher rates of stiffness of the knee after replacement surgery. Patients who had prior unicompartmental knee replacement (UKA) or high tibial osteotomy (HTO) who now require a total knee replacement may have higher incidence of stiffness.
- Patients with decreased range of motion of the knee prior to the surgery also may experience stiffness of the knee after replacement.
- Patients with multiple medical comorbidities may experience increased incidence of stiffness post surgery.
A low threshold of pain may play a role in post knee replacement stiffness. Patients with a low pain threshold may not participate in the post replacement physical therapy.
Intraoperative Factors
- Implant mal-positioning is the most common intraoperative factor.
- A wrong size of implant may affect the bending and straightening of the knee leading to stiffness.
- Excessive or inadequate cutting of the bone while preparing the bone for implant placement may also lead to postoperative stiffness.
- Inadequate removal of bone spur (osteophytes) may play a role in postoperative stiffness.
Postoperative Factors
- Infection of the joint may lead to swelling and inflammation that may lead to postoperative knee stiffness. The infection may also lead to formation of fibrosis tissue.
- Delayed participation in physical therapy is the most common cause of knee stiffness following replacement surgery. The delayed participation may be a result of patient selection, patient motivation, low pain threshold or a history of medical comorbidities.
- Heterotrophic ossification is formation of abnormal bone tissue in place where it is not normally present such as muscles. Formation of bone tissue in muscles may lead to postoperative stiffness.
- Excessive use of blood thinners may lead to formation of blood collections in the knee that may contribute to knee stiffness.
The range of motion of the knee continues to rapidly improve in the first 4 weeks of the surgery. The range of motion further improves in the first 3 months and continues till the first 6 months. Rarely some patients may show improvement in range of motion even after 6 months to 2 years.
Exercise therapy is started the day after surgery and the therapy in the first 4 weeks plays an important role in preventing stiffness. However patients who have inadequate range of motion despite optimal therapy may need further evaluation. Patients with limited range of motion complain of difficulty sitting and rising from the chair as well as difficulty in navigating stairs.
Intraoperative image of total knee replacement.
The physician may request radiological studies in the form of X-ray or CT after a thorough physical examination. Blood tests may be done to rule out infection of the prosthetic joint.
Symptoms and Diagnosis
The primary symptom of stiff TKA is a reduced ability to move the knee through its full range of motion. This can be quantitatively assessed using the “range of motion” (ROM) metric, which measures the degrees through which the knee can be flexed and extended. A normal knee joint typically has a ROM between 0 degrees (fully extended) and 135 degrees (fully bent). Postoperative stiffness is often defined as having less than 80-90 degrees of flexion.
Diagnosis
Diagnosis of stiff TKA is typically made based on the patient’s clinical symptoms and a physical examination. Imaging tests like X-rays or MRIs may be used to assess the alignment of the knee implant and the presence of any obstructions or abnormal tissue growth.
Treatment
The treatment for stiff TKA involves a combination of non-invasive and invasive approaches depending on the severity of the stiffness and the underlying causes. Initial treatments often include physical therapy to enhance flexibility and strength. If non-invasive methods are insufficient, procedures such as manipulation under anesthesia (MUA) or revision surgery might be considered.
Physical therapy plays a crucial role, focusing on exercises that promote range of motion, strength, and overall knee function. MUA, on the other hand, involves the mechanical breaking of scar tissues while the patient is under anesthesia, which can help improve mobility.
For cases where physical therapy and MUA do not yield the desired outcomes, surgical interventions might be necessary. These could include removing excessive scar tissue or revising the knee prosthesis itself.
Nonoperative management is tried first in the form of physical therapy if the initial therapy was not optimal. Continuous passive motion machines (CPM) may help the patients achieve an optimal range of motion.
Manipulation under Anaesthesia (MUA)
Manipulation under anesthesia is a non operative technique to manage knee stiffness following surgery. The manipulation is performed in patients who are unable to bend their knees less than 90 degrees. The manipulation has best results if performed in the first 3 months of the surgery.
During manipulation, the patient is put under general anesthesia. In general anesthesia, the patient sleeps while his/her muscles are relaxed. The surgeon then tries to physically bend or straighten the knee with an aim to break the fibrosis tissue adhesions.
Not all patients are candidates for manipulation under anesthesia as excessive manipulation may carry a risk of fracture or rupture of extensor mechanism (patella fracture, patellar tendon rupture, etc).
Other operative
In rare cases, where non operative methods have failed, some patients may benefit from arthroscopic lysis (cutting) of the fibrous adhesions. A small miniature camera along with miniature instruments are introduced in the knee joint and the surgeon uses the instruments to cut the fibrous adhesions.
In some cases, especially where the stiffness is a result of implant mal-position, a revision knee replacement surgery may be done.
Do you have more questions?
What exactly causes scar tissue to form excessively after knee replacement surgery?
Excessive scar tissue can form due to a combination of the body’s natural healing process and factors such as the patient’s individual inflammatory response, prolonged immobility, or suboptimal surgical technique. Keeping the joint moving and ensuring proper alignment during surgery can help minimize this risk.
Are there specific risk factors that increase the likelihood of developing stiff TKA?
Yes, risk factors include advanced age, obesity, diabetes, smoking, and previous knee surgeries. Patients with inflammatory joint diseases like rheumatoid arthritis are also at higher risk.
How is the range of motion (ROM) measured clinically?
ROM is measured using a device called a goniometer, which assesses the degree of knee flexion and extension during physical examination.
What is considered a normal range of motion after knee replacement?
A normal range of motion after knee replacement is typically 0 degrees of extension to at least 115 degrees of flexion, though individual outcomes can vary.
Can stiffness resolve on its own without intervention?
In some mild cases, stiffness might improve with regular activity and exercises. However, persistent stiffness usually requires professional intervention
What are the first steps in treating stiffness after TKA if noticed early?
Early treatment typically involves physical therapy focused on mobility exercises, possibly combined with anti-inflammatory medications to reduce pain and facilitate movement.
How effective is manipulation under anesthesia, and what are the risks?
Manipulation under anesthesia is generally effective in improving ROM when conservative measures fail. Risks include fractures, ligament injuries, or increased pain, although these are rare.
When is surgical revision considered necessary?
Surgical revision is considered if both physical therapy and manipulation under anesthesia do not adequately improve ROM or if there are structural problems with the prosthesis itself.
Can changes in lifestyle improve outcomes after experiencing stiffness?
Yes, maintaining a healthy weight, staying active, and adhering to a regular stretching and strengthening routine can improve outcomes and possibly prevent worsening stiffness.
What long-term care is recommended for someone with stiff TKA?
Long-term care includes regular follow-up visits with the orthopedic surgeon, ongoing physical therapy as needed, and continuous monitoring of knee function.
Are there any alternative therapies for treating stiffness?
Some patients find relief through acupuncture, hydrotherapy, or massage, though these should complement, not replace, traditional treatments.
How soon after surgery can stiffness begin to develop?
Stiffness can begin to develop as early as a few weeks post-surgery, particularly if the knee is not mobilized early or adequately.
Is there a genetic predisposition to developing stiffness?
There is some evidence suggesting genetic factors might influence the healing process and scar tissue formation, though research is ongoing.
What advancements in surgical techniques have reduced the incidence of stiff TKA?
Advances include improved prosthetic designs, better precision in implant placement, and minimally invasive surgical techniques that preserve muscle and tissue integrity.
How does patient psychology affect recovery from stiff TKA?
Patient motivation and mental health significantly affect recovery. Depression or anxiety can hinder participation in rehabilitation and negatively impact outcomes.
What are the indicators that a revision surgery might be successful in resolving stiffness?
Good indicators include identifiable mechanical issues with the implant, localized scar tissue that can be removed, or correctable misalignments
Are certain types of knee implants less likely to cause stiffness?
Yes, implants that more closely mimic the natural knee mechanics and those designed for high flexion tend to have lower rates of stiffness.
What role does diet play in recovery from knee surgery and preventing stiffness?
A healthy diet rich in vitamins, minerals, and anti-inflammatory foods can promote healing and reduce inflammation, aiding in the recovery process.
Can stiffness after knee replacement be completely cured?
While it may not always be possible to completely restore the original range of motion, significant improvements can often be achieved through appropriate interventions.
What are the complications of untreated stiff TKA?
Untreated stiffness can lead to chronic pain, decreased mobility, and deterioration of muscle function around the knee. This can severely impact the patient’s ability to perform daily activities and may lead to further surgical interventions.
How can stiffness after knee replacement impact a patient’s mental health?
Limited mobility and chronic pain associated with stiffness can lead to frustration, anxiety, and depression, significantly impacting the patient’s overall well-being and quality of life.
Is stiffness more common in older adults?
Yes, older adults may be more prone to stiffness due to decreased tissue elasticity and slower recovery rates, as well as more common pre-existing conditions such as osteoarthritis.
How does the rehabilitation program differ for patients with stiff TKA compared to typical post-knee replacement patients?
Rehabilitation programs for stiff TKA often require more intensive physiotherapy focused on increasing range of motion. These programs may also be longer and more aggressive, involving more frequent sessions.
What preventive measures can be taken before knee replacement surgery to reduce the risk of stiffness?
Preoperative measures include optimizing the patient’s health through weight management, strengthening exercises, and controlling blood sugar levels in diabetic patients. Pre-surgical physiotherapy can also prepare the tissues and improve outcomes.
What should patients expect during the recovery period to minimize the risk of developing stiffness?
Patients should expect to actively participate in a rigorous physiotherapy regimen, adhere to pain management strategies, and keep regular follow-up appointments with their surgeon. Immediate postoperative mobilization, as guided by the healthcare team, is crucial to minimize stiffness.
My name is Dr. Suhirad Khokhar, and am an orthopaedic surgeon. I completed my MBBS (Bachelor of Medicine & Bachelor of Surgery) at Govt. Medical College, Patiala, India.
I specialize in musculoskeletal disorders and their management, and have personally approved of and written this content.
My profile page has all of my educational information, work experience, and all the pages on this site that I've contributed to.
