Clunking Knee after Knee Replacement
It’s normal for people to experience knee pain from time to time. But, if the pain becomes severe, disrupts your daily life, or is accompanied by swelling, redness, or warmth, it’s wise to see a doctor.
At Complete Orthopedics, our team of knee specialists offers a range of treatments for knee pain, including surgery when needed. We have locations in New York City and Long Island and operate in six hospitals, providing top-notch surgical and orthopedic care. To make an appointment with one of our surgeons, you can either book online or call us.
Learn about the common causes of knee pain and the treatments available, including when surgery is the best option.
Overview
Some patients may experience a painful clunking of the knee on straightening the knee after a knee replacement. The symptom may be a sign of patellar clunk syndrome. Patellar clunk syndrome occurs as a result of the formation of a fibrous nodule on the undersurface of the lower end of thigh muscles. The symptom is associated with the use of older implants and is rare with the designs of modern implants.
During knee replacement surgery, the surgeon replaces the diseased/arthritic parts of the knee joint with prosthetic parts. The lower end of the thigh bone (femur) is replaced with a metallic component fixed with bone cement. Similarly, the upper part of the shin bone (tibia) is replaced with a metallic component fixed similarly with bone cement.
X-ray showing total knee replacement and the site of fibrous tissue in patellar clunk syndrome.
The undersurface of the kneecap (patella) is replaced with a high-grade plastic component. The femoral component has a groove on the upper surface for the patella to glide smoothing as the knee bends and straightens.
The thigh muscles (quadriceps) in front of the thigh are attached to the shin bone (tibia) with the patellar tendon. The quadriceps muscle is attached to the patella and the patellar tendon extends from the patella to the tibial tuberosity.
The exact cause of the formation of fibrous tissue underneath the quadriceps muscle near the patella is unknown. The scar formation has been hypothesized due to direct injury to the quadriceps muscle during patellar cutting and as a result of the small size of the patellar component.
The patellar clunk syndrome occurs exclusively in posterior stabilized implants as the fibrosis tissue is prone to get engaged in box shaped wedge of the femoral component.
Causes
A clunking sensation or noise after a knee replacement can be concerning, but it is relatively common and often benign. Here are several potential causes:
Scar Tissue or Fibrous Nodule Formation: One of the most common reasons for a clunking sensation is the formation of scar tissue or fibrous nodules around the knee joint. As you move, this tissue can snap over the prosthetic components of the knee, creating a clunking or clicking sound.
Implant Malposition or Loosening: If the knee replacement components are not properly aligned or become loose, they might not move smoothly, causing a clunking sensation. This could be due to issues during the surgery or changes over time.
Patellar Issues: Problems with the kneecap (patella), such as maltracking or instability, can lead to noises when the knee is bent or straightened. This could be due to the way the patella interacts with the rest of the knee joint.
Soft Tissue Impingement: Soft tissues (like tendons or muscles) around the knee can sometimes become trapped between the components of the implant during movement, leading to a clunking noise.
Wear of Components: Over time, the components of the knee implant can wear down, leading to misalignment and increased movement between parts, which can cause clunking or other noises.
Symptoms
Symptoms of clunking in the knee after a replacement surgery can vary depending on the underlying cause and individual factors. Here are some common symptoms that patients might experience:
Clunking Sensation: The most obvious symptom is a noticeable clunking or clicking sensation within the knee joint when straightening or bending the knee. This sensation may occur intermittently or consistently, and patients often describe it as feeling like something is moving or catching within the joint.
Pain or Discomfort: Clunking in the knee may be accompanied by pain or discomfort, particularly if it is due to issues such as implant loosening, misalignment, or soft tissue irritation. The pain may range from mild to severe and may be localized to the knee joint or radiate to surrounding areas.
Swelling: In some cases, clunking in the knee may be associated with swelling or inflammation around the joint. This swelling may be visible as increased size or fullness around the knee, and the skin over the joint may feel warm to the touch.
Stiffness or Limited Range of Motion: Clunking in the knee may contribute to stiffness or a limited range of motion in the joint. Patients may find it difficult to fully straighten or bend the knee, and there may be a sensation of tightness or resistance during movement.
Instability or Feeling of Giving Way: Clunking in the knee can sometimes lead to feelings of instability or a sensation that the knee is giving way. This can be particularly concerning when walking, standing, or engaging in physical activities, as it may increase the risk of falls or injury.
Audible Sounds: In addition to the sensation of clunking, patients may also hear audible sounds such as clicking, popping, or grinding coming from the knee joint during movement. These sounds may be present along with the clunking sensation or independently.
Difficulty with Activities: Clunking in the knee can interfere with daily activities and functional movements such as walking, climbing stairs, or getting up from a seated position. Patients may find that certain movements exacerbate the clunking sensation or increase pain and discomfort.
Risk factors
Preoperative patient factors such as low lying patella, a history of prior knee surgery, scar tissue/fibrous prior to knee replacement, knock knee deformity before surgery, etc. are risk factors for the development of patellar clunk syndrome.
A smaller patellar component or low placement of the patellar component also increases the risk of patellar clunk syndrome.
Mal-position of the femoral component and large size of polyethylene insert may also increase the risk of patellar clunk syndrome.
Diagnosis
If you suspect you have Patellar Clunk Syndrome, your doctor will likely conduct a physical examination of your knee and may order imaging tests such as X-rays or MRI scans. These tests help assess the alignment of the artificial joint and identify any abnormalities or rough surfaces that could be causing the patella to catch.
Treatment
The good news is that Patellar Clunk Syndrome is usually treatable, and several options are available depending on the severity of your symptoms:
Physical Therapy: Your doctor may recommend specific exercises to strengthen the muscles around your knee and improve its stability. Physical therapy can also help improve your range of motion and reduce the likelihood of the patella catching on the joint.
Medications: Over-the-counter pain relievers such as ibuprofen or acetaminophen can help alleviate any discomfort associated with Patellar Clunk Syndrome. In some cases, your doctor may prescribe stronger pain medications or anti-inflammatory drugs to manage pain and swelling.
Corticosteroid Injections: If conservative measures fail to provide relief, your doctor may recommend corticosteroid injections directly into the knee joint to reduce inflammation and alleviate symptoms.
Surgical Intervention: In severe cases where conservative treatments are ineffective, surgical intervention may be necessary. This could involve arthroscopic surgery to remove any bony overgrowths or scar tissue causing the patella to catch, or even revision surgery to replace the artificial joint with a different design or positioning.
Recovery
The recovery process after a knee replacement surgery is critical to achieving a good functional outcome and minimizing issues such as clunking. Here’s an overview of what this process typically involves, particularly addressing the concerns related to unusual sounds like clunking:
Initial Recovery Phase (0-6 Weeks)
- Pain Management: Immediately following surgery, managing pain is crucial. Pain relief measures, including medications, ice, and elevation, are employed to reduce swelling and discomfort.
- Physical Therapy: Starting physical therapy early is essential. The initial exercises focus on gentle knee movements to regain motion and prevent stiffness.
- Careful Mobilization: Patients are encouraged to start walking with support (like crutches or a walker) soon after surgery. This helps in strengthening the muscles around the knee.
Intermediate Recovery Phase (6-12 Weeks)
- Progressive Rehabilitation: As healing progresses, physical therapy sessions gradually become more intensive. Exercises aimed at strengthening the quadriceps, hamstrings, and other muscles around the knee are emphasized.
- Addressing Clunking: If clunking or clicking is noticed, it is usually monitored during this phase. Most often, these sounds diminish as muscle strength improves and the knee mechanism stabilizes.
Long-Term Recovery (3-6 Months)
- Continued Strengthening: Full recovery can take several months. Continuous physical therapy is important to regain complete functionality and reduce any mechanical sounds like clunking.
- Regular Follow-Ups: Regular check-ups with the orthopedic surgeon are necessary to ensure the prosthesis is functioning properly and to address any persistent issues.
Prevention
While it’s not always possible to prevent Patellar Clunk Syndrome entirely, there are steps you can take to minimize your risk:
- Follow your doctor’s post-operative instructions carefully, including any prescribed exercises or physical therapy.
- Attend all follow-up appointments to monitor the healing process and address any concerns promptly.
- Inform your doctor if you experience any unusual symptoms such as persistent pain, swelling, or clicking noises in your knee.
Conclusion
Patellar Clunk Syndrome may sound intimidating, but with the right knowledge and treatment, you can manage its symptoms effectively. If you’re experiencing any unusual noises or sensations in your knee after a replacement surgery, don’t hesitate to consult your doctor. By working together, you can identify the cause of your symptoms and develop a personalized treatment plan to get you back on your feet comfortably.
Do you have more questions?
How common is Patellar Clunk Syndrome after knee replacement surgery?
Patellar Clunk Syndrome occurs in a small percentage of patients undergoing knee replacement surgery, estimated to be around 1% to 3%.
Can Patellar Clunk Syndrome occur immediately after surgery, or does it develop over time?
It can happen either immediately after surgery or develop gradually over time as scar tissue forms around the joint.
Is Patellar Clunk Syndrome more common in certain types of knee replacement surgeries or implant designs?
Yes, certain factors like implant design, surgical technique, and patient-specific anatomy can influence the likelihood of developing Patellar Clunk Syndrome.
How long after knee replacement surgery does Patellar Clunk Syndrome typically develop?
It can vary from patient to patient, but symptoms typically arise within the first few months to a year after surgery.
Are there any specific risk factors that predispose someone to develop Patellar Clunk Syndrome?
Factors such as a history of knee trauma, previous surgeries, or underlying conditions like rheumatoid arthritis may increase the risk.
Can Patellar Clunk Syndrome lead to complications or further damage to the knee joint?
While it’s uncommon, severe cases of Patellar Clunk Syndrome can potentially lead to complications such as implant wear or instability if left untreated.
Is Patellar Clunk Syndrome more common in younger or older patients?
There’s no definitive age correlation, but younger patients with more active lifestyles may be at a slightly higher risk due to increased knee joint stress.
Are there any lifestyle modifications or activities that patients with Patellar Clunk Syndrome should avoid?
It’s generally advisable to avoid activities that exacerbate symptoms, such as high-impact sports or activities that involve repetitive knee bending.
Corticosteroid injections are generally safe but carry a small risk of complications such as infection, bleeding, or damage to surrounding tissues. Your doctor will discuss these risks with you before administering the injection.
Conservative treatments can be very effective, especially when combined with lifestyle modifications and medications. However, their success depends on the individual patient’s condition and response to treatment.
: What are the potential risks or side effects associated with corticosteroid injections for Patellar Clunk Syndrome?
Corticosteroid injections are generally safe but carry a small risk of complications such as infection, bleeding, or damage to surrounding tissues. Your doctor will discuss these risks with you before administering the injection.
Are there any alternative treatments or complementary therapies that can help manage Patellar Clunk Syndrome?
Some patients find relief from complementary therapies such as acupuncture, chiropractic care, or herbal supplements. However, the effectiveness of these treatments can vary, and it’s essential to discuss them with your doctor before trying them.
How long does it take to recover from surgical interventions for Patellar Clunk Syndrome?
Recovery time varies depending on the type of surgery performed and the individual patient’s healing process. In general, patients can expect several weeks to months of rehabilitation and recovery.
Are there any long-term implications of Patellar Clunk Syndrome on knee function or mobility?
With proper treatment and management, most patients can regain full function and mobility in their knees. However, some individuals may experience persistent symptoms or limitations, especially if complications develop.
Can Patellar Clunk Syndrome recur after successful treatment?
While recurrence is uncommon, it’s possible for symptoms to return if the underlying cause is not adequately addressed or if new issues arise.
Are there any specific exercises or stretches that can help prevent Patellar Clunk Syndrome from recurring?
Yes, your physical therapist can recommend specific exercises to strengthen the muscles around your knee and improve joint stability, reducing the risk of recurrence.
How often should patients with a history of Patellar Clunk Syndrome follow up with their healthcare provider?
It’s essential for patients to attend regular follow-up appointments with their doctor to monitor their knee health and address any concerns promptly.
Are there any dietary or nutritional recommendations that can help manage Patellar Clunk Syndrome?
While there are no specific dietary guidelines for Patellar Clunk Syndrome, maintaining a healthy weight and eating a balanced diet can support overall joint health and recovery.
Can Patellar Clunk Syndrome affect other activities of daily living, such as walking or climbing stairs?
Yes, depending on the severity of symptoms, Patellar Clunk Syndrome can impact various activities of daily living. Physical therapy and lifestyle modifications can help minimize these effects.
Are there any assistive devices or braces that can help alleviate symptoms of Patellar Clunk Syndrome?
In some cases, a knee brace or orthotic device may provide additional support and stability, reducing the likelihood of the patella catching on the joint.
How soon after knee replacement surgery can patients resume normal activities like driving or returning to work?
The timeline for returning to normal activities varies depending on the individual patient’s recovery process and the type of surgery performed. Your doctor will provide specific guidelines based on your unique situation.
Are there any advancements in surgical techniques or implant designs that can reduce the risk of Patellar Clunk Syndrome?
Yes, ongoing research and advancements in orthopedic surgery continue to improve implant designs and surgical techniques, reducing the incidence of complications like Patellar Clunk Syndrome.
What should patients do if they experience a sudden increase in pain or swelling in their knee after surgery?
Sudden increases in pain or swelling should be promptly evaluated by a healthcare provider to rule out complications such as infection or implant failure.
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.
