Hip replacement surgery, also known as total hip arthroplasty, is a common procedure done to replace a damaged or diseased hip joint with an artificial one. The hip joint is a ball and socket joint, where the round head of the femur (thigh bone) rotates within the cup-shaped socket of the pelvis. This allows a wide range of motion in the hip joint for activities like walking, climbing stairs, sitting and squatting.
After a total hip replacement, patients are usually advised by their surgeon to avoid bending their hip more than 90 degrees during the initial recovery period. This is to prevent dislocation of the new hip joint while the soft tissues heal and scarring develops around the joint to add stability. Excessive hip flexion beyond 90 degrees places more stress on the hip joint and can pop the ball out of the socket if done too early after surgery.
What defines bending more than 90 degrees?
The 90 degree safe zone refers to not flexing the hip joint greater than a right angle. Common activities that involve bending more than 90 degrees include:
– Tying shoes or picking up objects on the floor
– Getting in and out of low chairs or toilets
– Getting in or out of low vehicles
– Squatting or kneeling
– Doing exercises like yoga, pilates or dance moves requiring deep flexion
Sitting in a chair is usually fine, but getting up from a very low or soft chair requires more hip flexion. Sleeping on your side in a fetal position with knees drawn up higher than waist level can also bend the hip past 90 degrees.
Timeframe to avoid bending hip after surgery
The 90 degree hip flexion precautions are usually in place for around 6-12 weeks after surgery. The exact timeframe will vary based on factors like:
– Surgical approach – Anterior, posterior or lateral approaches have different healing times
– Use of minimally invasive or less invasive surgical techniques
– Patient health and bone quality
– Type of implants and fixation used
– Progress of post-op recovery and physical therapy
Your surgeon will assess your hip flexibility and stability at follow-up visits after surgery and advise you when it is safe to resume activities requiring greater hip bending. Listen to your surgeon or physical therapist’s guidelines on hip precautions.
Risks of bending more than 90 degrees
Bending past 90 degrees too soon after a hip replacement risks:
Dislocation:
– The hip ball can pop out of the socket if hip is flexed too far
– Dislocation rates within first 3 months after surgery range from 1% to 3%
– Greatest risk during activities like bending down, turning incorrectly, or falling
Soft tissue damage:
– Can overstretch tissues, muscles and ligaments healing around new joint
– Causes increased pain and swelling around the hip joint
– May slow down rehabilitation progress
Implant loosening:
– Excessive hip flexing applies more force and strain on components
– Can weaken bone-implant interfaces and cause loosening over time
– Higher risk of requiring early revision surgery
Fractures:
– Forceful bending can fracture hip bones weakened by surgery
– Pelvic fractures more common with anterior hip replacement approaches
– Stress fractures around implants also possible
Precautions to avoid bending hip too far
To avoid bending past 90 degrees and protect your new hip after replacement surgery:
– Use elevated toilet seats and chairs with armrests to avoid low sitting
– Avoid low beds and chairs – sleep on your back with a pillow between knees
– Pick up objects using a grabber tool instead of bending down
– Use a long shoehorn or slip-on shoes to put shoes on while seated
– Enter and exit vehicles leading with your non-operated leg
– Don’t cross your ankles or knees when sitting
– Don’t pivot or twist on your operated leg when standing up
Your physical therapist can recommend hip positioning techniques and devices like abduction pillows to help keep your hip safe. Listen to your body and stop any activity causing excessive hip discomfort.
Exercises to improve hip flexion
As healing progresses, your surgeon will clear you to start gradually improving your hip flexion. This is an important part of rehabilitation to restore range of motion. Initial exercises may include:
– Supine pelvic tilts – gently rock your hips to flatten lower back to floor
– Heel slides – slide operated heel towards buttocks, bending knee and hip
– Assisted knee to chest – use a strap to gently pull knee up to chest
– Prone hip extension – lying on stomach, lift leg up with knee straight
Your physical therapist can tailor flexibility and strengthening exercises to gradually allow for greater hip flexion. Avoid forcing any painful movements and stop if you feel any popping. Use ice and pain meds after exercises to manage discomfort.
When can I resume deeper bending after hip replacement?
Your surgeon will evaluate hip mobility at follow-up visits around 6-12 weeks post-op. Once adequate healing and joint stability are confirmed via x-ray and physical exam, they may clear you to progress beyond 90 degree precautions.
Timeline examples:
Time after Surgery | Activities Typically Allowed |
---|---|
6 weeks | Sitting in low chairs |
8-12 weeks | Bending over to tie shoes |
3 months | Getting in and out of bath |
4-6 months | Squatting and kneeling |
9-12 months | Yoga, dance, pilates |
Follow your surgeon’s specific instructions on gradually increasing hip flexion once adequate joint stability and healing allows. Avoid rushing return to deep bending activities before cleared.
Outcomes of bending too early
While the occasional brief slip of flexing too far may just cause some pain, repeatedly bending the hip beyond 90 degrees too soon after replacement can result in:
– Hip dislocation requiring an ER visit to reposition the joint
– Significant setbacks in hip recovery, requiring more restrictions
– Extra physical therapy to regain lost progress
– Higher risk of hip implant loosening or other complications
– Need for revision surgery if complications like dislocations recur
Some patients may require precautions for longer than typical if healing is delayed. Listen to your surgeon’s advice and take it slow to avoid complications. Notify your surgeon about any unusual hip pain with activity. With proper precautions during the hip replacement recovery period, you can successfully return to fuller mobility.
Conclusion
Avoiding excessive hip flexion beyond 90 degrees after hip replacement surgery is crucial to allow the tissues to heal properly around the implant. Typically hip bending precautions are in place for 6-12 weeks post-operatively. Slowly progressing hip flexibility under your surgeon’s guidance is key to regaining mobility without damaging the new joint or risking dislocation. With patience and by following activity restrictions, you can successfully bounce back from hip replacement and enjoy your new joint.