What causes a sharp pain on the outside-inside of my knee?
Written by:
Dr. Chinmay Gupte, PhD, FRCS(Tr&Orth)
Dr. Chinmay Gupte is a leading knee specialist, consultant orthopaedic surgeon, and Clinical Reader at Imperial College London. He directs the Wellington Knee Unit, London’s first dedicated knee clinic, and specializes in meniscal and ligament injuries, ACL reconstruction, knee arthritis, and robotic knee replacement surgery.
Dr. Gupte combines extensive clinical expertise with patient-centered care, treating both adults and children with complex knee conditions.
Sharp knee pain, whether on the inside or outside, can feel overwhelming and disruptive. The exact cause can differ from person to person, but it often appears during leg workouts, while climbing stairs, or even when simply standing up.
Identifying the root cause is important, as the pain might signal anything from a minor strain to a more serious ligament injury. If you are experiencing this discomfort and looking for clear insights into possible causes, treatment options, and prevention strategies, this guide will walk you through everything you need to know.However, it is always best to consult a qualified healthcare professional for a proper diagnosis and personalized treatment plan.
Common Symptoms of Sharp Knee Pain
Knee pain is often accompanied by other symptoms that can provide important clues about the underlying issue. Along with sharp discomfort, you might experience:
· Swelling or stiffness around the joint
· Popping or clicking sounds when moving the knee
· Locking or difficulty fully bending or straightening the knee
· A feeling of instability, as if the kneecap might give way while walking
· Pain that worsens with activity such as running, squatting, or climbing stairs
Sharp Knee Pain on the Inside or Outside of the Knee: What Could Be the Cause?
Sharp knee pain can be triggered by several different conditions, ranging from mild to more serious. Understanding the possible causes is the first step toward effective treatment and prevention. Here are some of the most common reasons:
1. Meniscus Tear (Cartilage Injury)
The meniscus, a C-shaped cartilage, works like a cushion around the knee and helps to protect the knee joint. A sudden pressure and twist can tear it, causing sharp pain, often inside the knee.
● Pain becomes worse when squatting, twisting, or turning quickly
● A"pop" may be felt or heard at the moment of injury
● Swelling and inflammation often appear within 24 hours
If the pain or swelling does not improve with rest and ice, it is important to consult a healthcare professional for proper diagnosis and treatment.
2. Ligament Injuries (ACL, MCL, LCL)
Depending on which ligament is affected, the location and severity of pain can differ:
Medial Collateral Ligament (MCL) injury:Pain is usually felt on the inside of the knee. It often occurs in athletes during contact sports.
Lateral Collateral Ligament (LCL) injury:Pain is typically felt on the outside of the knee, often after a blow to the knee or a twisting injury.
Anterior Cruciate Ligament (ACL) tear:Causes sudden, sharp pain along with instability or a “giving way” sensation in the knee.
3. Osteoarthritis of the Knee
Osteoarthritis is a degenerative condition where knee cartilage wears down over time, reducing the joint’s ability to absorb shock. Common symptoms include:
● Sharp or dull pain inside or outside the knee
● Stiffness or pain after long-term sitting
● Symptoms that gradually worsen with age or activity
4. Iliotibial Band (IT Band) Syndrome
IT Band Syndrome is especially common in runners and cyclists. It occurs when the iliotibial band, a thick band of tissue running along the outside of the thigh, rubs against the knee joint.
● Pain is usually sharp and located on the outside of the knee
● Symptomsworsen with repetitive activities such as running, cycling, or climbing
Rest, stretching, and physiotherapy can help, but persistent cases should be evaluated by a doctor.
5. Bursitis
Bursae are small, fluid-filled sacs that cushion and protect the knee joint. When they become inflamed, the condition is called bursitis. Bursitis may cause:
● Sharp pain near the joint line
● Swelling or warmth over the knee
● Discomfort when kneeling or climbing stairs
6. Patellar (Kneecap) Issues
Dislocation or misalignment of the kneecap can trigger sudden, sharp pain felt on either the inside or outside of the knee. This may also cause visible deformity, swelling, and difficulty straightening the leg. Prompt medical care is important to reposition the kneecap and prevent further damage.
What to Expect During a Consultation for Sharp Knee Pain?
A typical evaluation may include:
Diagnostic Steps:
● Detailed medical history (Reviewing patterns in sports participation, past injuries, and lifestyle habits)
● Physical examination (Checking for swelling, tenderness, stability, and range of motion)
Imaging tests:
● X-raysdetect bone changes or signs of arthritis
● MRIscansto identify ligament or cartilage injuries
● Ultrasound to evaluate soft tissue damage around the knee
Treatment Options for Sharp Pain Inside/ Outside the Knee
The right treatment depends on the underlying cause. Options include both non-surgical and surgical approaches:
1. Non-Surgical Treatments
· RICE Treatment - Rest, Ice, Compression, and Elevation for minorinjuries.
· Anti-inflammatory and mild pain medications to manage pain and swelling
· Physiotherapy to strengthen muscles and restore mobility
· Knee braces or supports for stability and protection
2. Surgical Treatments
If conservative methods don’t provide relief, surgical interventions may be considered, including:
● Arthroscopic, or Keyhole, Meniscus Repair or Removal
● Ligament Reconstruction (e.g., ACL, MCL surgery)
● Partial or Total Knee Replacement (for advanced arthritis)
Lifestyle & Prevention Tips for Sharp Knee Pain
Lifestyle habits play an important role in knee health. Adopting healthy routines can lower the risk and support stronger, more resilient joints
Exercise & Stretching
● Warm-up with 5 to 7 minutes of light cardio
● Stretch the hamstrings, quadriceps, and glutes for improved stability
● Focus on strength training to support the knee joint
Nutrition for Healthy Knees
● Add Omega-3-rich foods like salmon, flaxseeds, and walnuts to help reduce inflammation and support joint health.
● Include foods high in calcium and vitamin D such as dairy, leafy greens, or fortified cereals to keep bones strong and knees resilient.
Lifestyle Habits
● Wear well-cushioned footwear when running or walking
● Avoid sudden increases in workout intensity
● Maintain a healthy body weight to reduce stress on the knees
Tip: Small lifestyle changes can make a big difference in preventing sharp knee pain and keeping your joints healthy with growing age.
When Exercise Can Worsen Pain?
Exercise is generally good for your joints, but in certain situations, it can do more harm than good
● High-impact movements like running on hard surfaces, jumping, or doing heavy, deep squats may put extra strain on the knees and worsen pain.
● Existing ligament or cartilage injuries can flare up during exercise, often requiring rest or medical attention before resuming activity.
● Pushing through pain instead of listening to your body can aggravate the injury and slow down recovery
Comparing Inside vs. Outside Knee Pain for Better Understanding
Understanding whether pain occurs on the inside or outside of the knee can help narrow down possible causes. Here’s how they differ:
1. Common Causes
Inner Knee Pain - Meniscus tear, MCL injury, or early arthritis
Outer Knee Pain - IT band syndrome, LCL injury, and overuse from running
2. Typical Patients
Inner Knee Pain -More common in middle-aged adults and athletes in contact sports
Outer Knee Pain -Often affects runners, cyclists, and those doing repetitive knee-bending activities
3. Pain Triggers
Inner Knee Pain - Mainly twisting, squatting or climbing stairs.
Outer Knee Pain - Prolonged running, repetitive knee-engaged activity, or walking downhill
4. Associated Symptoms
Inner Knee Pain - Locking, swelling, or tenderness on the inner side
Outer Knee Pain - Sharp stabbing pain or tenderness on the outer surface of the knee
5. Duration of Pain
Inner Knee Pain - Often persistent, especially with arthritis or chronic injuries
Outer Knee Pain - Often intermittent, appearing during repetitive activities like running or cycling
When Should You See a Doctor?
Seek medical care immediately if you experience
:● Severe swelling or inability to bear weight
● A popping sound followed by instability
● Persistent pain lasting more than two weeks
● Visible deformity in the knee
Early diagnosis and treatment from a qualified healthcare professional can prevent further damage and help speed up recovery.
FAQ – Sharp Knee Pain
Q1. Why do I feel sharp pain only when climbing stairs?
This often happens due to cartilage wear, early arthritis, or patellar maltracking. These conditions put extra stress on the joint when the knee bends.
Q2. Can sharp knee pain heal on its own?
Some mild strains may improve naturally with rest, ice, and activity modification. However, cartilage damage, ligament injuries, and arthritis usually need professional assessment and treatment.
Q3. Is sharp knee pain always a sign of surgery?
Not necessarily. Many cases improve with non-surgical treatments such as physiotherapy, medications, or bracing. Surgery is usually considered only for severe injuries or long-term pain that doesn’t respond to conservative care.
Q4. Why do I get pain outside my knee when I run?
This is often caused by iliotibial band (IT band) syndrome, where the tissue on the outside of the thigh rubs against the knee. It can result from overtraining, tight muscles, or improper footwear.
Q5. When should I see a doctor for sharp knee pain?
If pain is severe, lasts longer than two weeks, or is accompanied by swelling, instability, or difficulty moving, it’s important to consult a knee specialist for timely diagnosis and treatment.
