It’s not all that uncommon to have some knee pain after a hip replacement. Changes in the length of your leg can put some additional pressure or stress on your knee joint. Another common cause is that the sensory nerves that lie over your hip also provide sensation to your knee. This can cause perceived knee pain when it’s really coming from your hip.
Additionally, a total hip replacement may cause pain at first until your bone and the implant unite, which can be felt around your knees.
But you may want to get medical attention if your knee pain continues longer than a few months after surgery.
Read on to learn what can cause knee pain after a hip replacement, how long this type of pain typically lasts, and what you can do to help ease knee pain.
The main cause of knee pain after a hip replacement is the change in the length of your leg.
Before a hip replacement, your leg may have shortened in length due to a reduction or erosion in hip cartilage and bone mass in your hip joint’s socket and in the head of your femoral bone, which inserts into your hip socket.
Knee pain may happen due to the new components of your hip that have been placed in the area around your hip joint, including a:
- new socket made of metal
- new ball made of ceramic or metal that replaces the head of your femur bone
- lining within the socket that helps the ball of your joint move smoothly
- rod made of metal that steadies the thighbone connected to the ball
After a hip replacement, you may still walk the way you did before the hip replacement for some time. This can cause your knee to experience extra pressure when you step down and hit the ground with more force while you adjust to your new gait, resulting in pain and inflammation.
A 2020 study also suggests that you might experience some pain in the opposite knee after a total hip replacement because you might walk differently to accommodate your new hip. This study showed no significant knee pain in the leg affected by the hip replacement, but a much more noticeable risk of pain in the opposite knee.
Pain in both your knee and thigh are also relatively common after a hip replacement. This is likely because of the swelling and inflammation that affects your thigh after a hip replacement due to the insertion of the new ball and metal rod into the upper part of your thighbone.
Shin pain after a hip replacement can result in changes to your leg length that cause you to walk differently.
In this case, you may compensate for the change in leg length by reducing how much pressure you put on the front of your foot when you take a step. This can weaken your calf muscles and cause your heel bone to hit the ground too hard as it takes more force when you step.
Over time, this change in your walk can cause pain and injury to your shin — often called
In addition to some of the causes we’ve discussed above, ankle and knee pain after a hip replacement can happen due to:
- damage to nerves around your hip that run to your ankle
- swelling down your leg to your ankle (typical after surgery)
- the use of a traction boot before or after surgery
- change in leg alignment
- infections around the surgical site
- components in the replaced hip coming loose
- inflammation in the tissue around your hip
- rubbing of your hip components on surrounding tendons
Knee pain after a hip replacement isn’t typically as severe as the pain around your hip itself. But the pain may be dull and aching when you’re not putting weight on your knee and feel much more severe when you’re walking, crouching, kneeling, or doing any other activities that require pressure on your knee joint.
The exact amount of knee pain can also depend on whether you’re following recovery and physical therapy recommendations after surgery. Knee pain should become less noticeable as you heal and learn to walk with your new hip
How long knee pain lasts after a hip replacement can differ from person to person.
You’ll likely experience knee pain for about 2 weeks and up to 1 month after surgery. But several factors can influence how long your knee pain lasts, including:
- how much activity you do while you’re recovering
- how closely you’re following physical therapy recommendations
- how much stretching you’re doing each day
- how regularly you’re taking prescribed pain medications
- the position you sleep in at night
There are many options to treat knee pain after a hip replacement. Physical therapy and temporary lifestyle changes can help reduce knee pain caused by the surgery. Additionally, the following may help.
Over-the-counter (OTC) pain medications are available at most pharmacies to help you quickly relieve knee pain. Common OTC pain medications include:
Try these home treatments to relieve knee pain:
- Use the rest, ice, compression, and elevation (RICE) method to reduce swelling and stress.
- Alternate between applying heat and cold to your knee every 20 minutes.
- Adjust your posturewhen you stand or sit to reduce pressure on your hip and legs.
- Gently massage your knee and the surrounding areas of your leg.
- Use a heateror move to a warmer environment during healing.
- Use alternative pain relievers, such as cannabidiol (CBD), under guidance from a doctor or healthcare professional. Please note that CBD isn’t legal federally or in all states in the United States, and it’s not currently recommended for pregnant/breastfeeding people or those younger than 25 years old. Check the National Conference of State Legislatures (NCSL)‘s site to review your state’s laws.
- Wear compression stockings.
Exercises for knee pain after hip replacement
Here are some exercises you can try to relieve knee pain after a hip replacement, especially as your hip heals and you’re permitted to do light physical activity:
Prescription-strength medications containing acetaminophen and other pain relievers, such as hydrocodone, may be recommended if your pain is severe or unmanageable.
A doctor likely won’t recommend most prescription-strength opioids, such as oxycodone or fentanyl, unless your pain is extreme and there’s no other immediate way to treat or relieve it. These medications should only be used for a short time and in limited doses because they pose a high dependance risk.
In some cases, a doctor may recommend surgery if your knee is injured and needs repair or replacement. Some causes of pain may be treated using an arthroscope, a thin lighted tube that can be easily inserted into your knee, and small instruments to treat your knee.
Other, more extensive injury or damage may require a knee replacement. As with a hip replacement, this involves inserting new metal or ceramic components into your knee to replace damaged or missing bone and cartilage.
Get immediate medical attention if you notice any of the following:
- pain that’s severe and isn’t getting better over time
- swelling that doesn’t go down over time
- unusual bruising around your knee or other areas of your leg
- pain in your body not close to your knee or hip
- not being able to walk without extreme pain
- an unusual deformity in your knee or leg
Knee pain after a hip replacement is common. You may also experience pain in your groin, thigh, shin, and ankle.
Most knee pain goes away on its own and can be relieved at home with rest and home treatments. See a doctor if your pain isn’t getting any better or if you’re unable to walk without severe pain in your knee or hip.