Post OP Knee Replacement Comlications

I had a partial knee replacement on Nov 23 and I’ve run into some complications. I have numbness on the side of the knee surgery and now the numbness has spread over to the right side. In addition after the surgery I had nerve numbness and tingling on the lateral side of my leg and down to the third and fourth toe. So I wanted to do some research and this is what I found.


After partial knee replacement should there be numbness in the knee and what percentage of people have numbness their whole life?

Numbness around the knee after a partial knee replacement is a relatively common experience due to the surgical procedure. Here’s a detailed explanation:

Causes of Numbness After Partial Knee Replacement

  1. Surgical Incision:
    • During the surgery, incisions are made in the skin, and nerves in the area can be affected. This can lead to temporary or permanent numbness.
  2. Nerve Damage:
    • Small sensory nerves that supply the skin over the knee can be cut or stretched during surgery. The infrapatellar branch of the saphenous nerve is particularly susceptible to injury.
  3. Swelling and Inflammation:
    • Postoperative swelling and inflammation can compress nerves, contributing to a sensation of numbness.

Duration and Prevalence of Numbness

  1. Temporary Numbness:
    • In many cases, numbness is temporary. It may gradually diminish over weeks to months as the nerves heal and regenerate.
  2. Permanent Numbness:
    • Some patients may experience permanent numbness. The extent and location of numbness can vary.
    • Prevalence: Studies suggest that a significant proportion of patients experience some degree of numbness after knee replacement surgery. Approximately 50-70% of patients report some numbness initially.
    • Long-term Numbness: About 10-20% of patients may have persistent numbness that lasts their entire life.

Management and Considerations

  1. Postoperative Care:
    • Follow your surgeon’s postoperative care instructions carefully to minimize swelling and inflammation.
    • Physical therapy can aid in recovery and improve overall function, although it may not directly affect numbness.
  2. Monitoring and Consultation:
    • Regular follow-up with your surgeon is important. Report any changes or concerns, including persistent numbness or other unusual sensations.
    • If numbness persists or worsens, your surgeon might evaluate for any complications.
  3. Adaptation:
    • Patients with permanent numbness generally adapt over time. The numbness typically does not interfere significantly with the function of the knee or overall mobility.


Numbness after a partial knee replacement is common due to the nature of the surgery and potential nerve involvement. While most patients experience some degree of numbness initially, it often diminishes over time. However, a minority of patients (approximately 10-20%) may have permanent numbness. Regular follow-up with your healthcare provider and adherence to postoperative care can help manage and monitor this condition effectively.

Can a partial knee replacement cause Baker’s cyst?

A Baker’s cyst, also known as a popliteal cyst, is a fluid-filled swelling that develops at the back of the knee. It is usually associated with underlying knee conditions such as arthritis, meniscal tears, or other joint problems that lead to an overproduction of synovial fluid. Here’s how a partial knee replacement might be related to the development of a Baker’s cyst:

Connection Between Partial Knee Replacement and Baker’s Cyst

  1. Underlying Knee Conditions:
    • The primary reasons for undergoing a partial knee replacement—such as osteoarthritis or other degenerative joint diseases—are also common causes of Baker’s cysts. The persistent or recurrent inflammation associated with these conditions can lead to the formation of a Baker’s cyst.
  2. Post-Surgical Inflammation:
    • After a partial knee replacement, the knee joint may experience inflammation as part of the healing process. This inflammation can increase the production of synovial fluid, potentially leading to the formation or exacerbation of a Baker’s cyst.
  3. Altered Joint Mechanics:
    • Changes in the mechanics of the knee joint following surgery might contribute to an uneven distribution of joint fluid or increased pressure in certain areas, which could contribute to cyst formation.
  4. Synovial Fluid Dynamics:
    • The surgery itself can alter the dynamics of synovial fluid within the knee joint. If the fluid cannot be adequately absorbed or drained, it might accumulate and form a cyst.

Prevalence and Incidence

  • While it is not very common, some patients may develop a Baker’s cyst after a knee replacement surgery, including partial knee replacements. This occurrence is generally considered a complication and not a direct result of the surgical procedure.

Symptoms and Diagnosis

  • Symptoms: A Baker’s cyst can cause swelling behind the knee, a feeling of tightness, pain, and limited range of motion.
  • Diagnosis: Diagnosis is typically made through clinical examination and confirmed with imaging studies such as ultrasound or MRI.

Management and Treatment

  1. Observation:
    • If the cyst is not causing significant symptoms, it may be monitored over time.
  2. Non-Surgical Treatment:
    • Aspiration: Removing excess fluid from the cyst with a needle can provide temporary relief.
    • Corticosteroid Injections: Reducing inflammation in the knee joint can help decrease cyst size and symptoms.
    • Physical Therapy: Exercises to strengthen the muscles around the knee can improve joint function and reduce fluid buildup.
  3. Surgical Treatment:
    • In cases where the cyst causes significant symptoms or complications, surgical removal may be considered. This is less common and typically a last resort.


While a partial knee replacement does not directly cause a Baker’s cyst, the underlying knee conditions that necessitate the surgery, as well as postoperative changes and inflammation, can contribute to the development or exacerbation of a Baker’s cyst. If you experience symptoms of a Baker’s cyst after knee replacement surgery, it is important to consult with your healthcare provider for appropriate diagnosis and management.

If a baker’s cyst keeps returning in the right knee what are my options to correct the problem?

Recurrent Baker’s cysts, also known as popliteal cysts, can be frustrating and painful. Addressing the underlying cause of the cysts is crucial for effective treatment. Here are several options to consider for managing and potentially correcting recurrent Baker’s cysts:

1. Conservative Management

a. Physical Therapy

  • Exercises: Strengthening the muscles around the knee (e.g., quadriceps, hamstrings) can help stabilize the joint and reduce stress.
  • Flexibility: Stretching exercises can improve the range of motion and reduce stiffness.

b. Medication

  • Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): These can help reduce pain and inflammation.
  • Corticosteroid Injections: Injections into the knee joint can reduce inflammation and fluid production.

c. Aspiration

  • Fluid Drainage: A doctor can use a needle to aspirate (drain) the excess fluid from the cyst, providing temporary relief.

2. Addressing Underlying Conditions

a. Arthritis Management

  • Medication: Disease-modifying antirheumatic drugs (DMARDs) or biologics for rheumatoid arthritis.
  • Joint Injections: Corticosteroids or hyaluronic acid injections can help reduce inflammation and pain.

b. Meniscal Tears

  • Physical Therapy: Exercises to strengthen the knee and improve stability.
  • Surgery: Arthroscopic surgery to repair or remove the damaged part of the meniscus.

3. Surgical Options

a. Cyst Removal (Cystectomy)

  • Open Surgery: Removing the cyst through a surgical incision.
  • Arthroscopic Surgery: A minimally invasive option that uses small incisions and a camera to guide the removal.

b. Joint Repair

  • Meniscal Repair: If a meniscal tear is causing the cyst, repairing the meniscus may prevent recurrence.
  • Synovectomy: Removing inflamed synovial tissue if there is chronic inflammation contributing to cyst formation.

4. Minimally Invasive Procedures

a. Endoscopic Procedures

  • Endoscopic Cyst Drainage: Using an endoscope to drain and remove the cyst with minimal incisions.

5. Lifestyle Modifications

  • Weight Management: Maintaining a healthy weight to reduce stress on the knee joint.
  • Low-Impact Exercise: Activities like swimming or cycling that do not strain the knee as much as running or jumping.

6. Alternative Therapies

  • Acupuncture: Some people find relief from symptoms through acupuncture.
  • Manual Therapy: Techniques such as massage or manipulation by a trained therapist.

When to See a Specialist

If conservative treatments are not effective and the Baker’s cyst keeps recurring, it is advisable to consult with an orthopedic specialist. They can assess the underlying causes in more detail and recommend the most appropriate treatment plan, which may include surgical options.


Managing recurrent Baker’s cysts involves a combination of addressing the underlying cause, conservative treatments, and potentially surgical interventions. Working closely with your healthcare provider to identify the best course of action based on your specific condition and symptoms is essential for effective management and long-term relief.

8 months after a partial knee replacement my knee is numb, in pain, and swollen. What could be the causes and why?

Experiencing numbness, pain, and swelling in your knee eight months after a partial knee replacement can be concerning. Several potential causes could contribute to these symptoms. Here are some common reasons and their explanations:

1. Nerve Damage or Impingement

  • Surgical Impact: Nerves around the knee, particularly the infrapatellar branch of the saphenous nerve, can be damaged during surgery. This can result in persistent numbness and sometimes pain.

  • Scar Tissue: Postoperative scar tissue can form around nerves, causing pain or numbness.

2. Infection

  • Postoperative Infection: Infections can occur after knee replacement surgery, leading to pain, swelling, redness, and warmth around the knee. This can happen immediately post-surgery or develop months later.
  • Symptoms: Fever, chills, and drainage from the surgical site, in addition to pain and swelling, may indicate an infection.

3. Prosthesis Issues

  • Loosening: The prosthetic components may become loose over time, leading to pain and instability.
  • Misalignment: Misalignment of the prosthesis can cause abnormal wear and pain.

4. Inflammation

  • Persistent Inflammation: Chronic inflammation in the joint can lead to ongoing pain and swelling. Conditions like arthritis can exacerbate this.
  • Bursitis: Inflammation of the bursa (fluid-filled sacs) around the knee can cause pain and swelling.

5. Hematoma

  • Blood Accumulation: A hematoma, or collection of blood, can form around the surgical site, causing pain and swelling.

6. Joint Effusion

  • Fluid Accumulation: Excess fluid within the joint can cause swelling and pain. This can be a reaction to the surgery or due to other underlying conditions.

7. Mechanical Problems

  • Wear and Tear: Over time, the components of the knee replacement can wear out, leading to pain and swelling.
  • Fracture: A fracture around the implant can cause severe pain and swelling.

8. Complex Regional Pain Syndrome (CRPS)

  • Chronic Pain Condition: CRPS is a chronic pain condition that can develop after surgery, leading to severe pain, swelling, and changes in skin color, and temperature.

Diagnostic Steps and Management

  1. Medical Evaluation:
    • Physical Examination: A thorough physical examination by your orthopedic surgeon or healthcare provider.
    • Imaging Studies: X-rays, MRI, or CT scans to check the position of the prosthesis, signs of loosening, misalignment, or fractures.
    • Blood Tests: To check for signs of infection or inflammation.
  2. Possible Treatments:
    • Medication: Anti-inflammatory drugs, pain relievers, or antibiotics if an infection is present.
    • Physical Therapy: To improve mobility, and strength, and reduce pain.
    • Aspiration: Draining excess fluid from the knee joint if there is significant swelling.
    • Surgical Revision: In cases where the prosthesis is loose, misaligned, or there is an infection that cannot be controlled with antibiotics.

When to Seek Immediate Medical Attention

  • Signs of Infection: Fever, chills, increased redness, warmth, and drainage from the surgical site.
  • Severe Pain: Pain that significantly limits your ability to move or bear weight.
  • Significant Swelling: Swelling that is persistent and worsening despite rest and medication.


Persistent numbness, pain, and swelling eight months after a partial knee replacement can have various causes, including nerve damage, infection, prosthesis issues, inflammation, hematoma, joint effusion, mechanical problems, and complex regional pain syndrome. A thorough evaluation by your healthcare provider is essential to determine the underlying cause and appropriate treatment. Early intervention can help prevent further complications and improve your overall outcome.