Fracture

• Post-operative falls cause fractures.

• The risk of a post-operative fracture after a fall is ~1%.

• Be careful getting in and out of the shower.

• Do not walk on slippery surfaces (icy sidewalks, wet floors, slippery grass).

• Use a walker until your balance has returned to normal.

• Walkers prevent falls.

• Ask for help from your support people.

• Intra-operative Fracture

• The risk of a fracture occurring during surgery is about ~0.25%

Dislocation

• The risk of a dislocation after anterior hip replacement is ~0.25% and ~0.5% after a posterior hip replacement.

• Posterior hip dislocations occur through flexion and internal rotation of the hip.

• Anterior hip dislocations occur through extension and external rotation of the hip.

• Spine fusion greatly increase the risk of a hip dislocation.

• Roughly a third of normal bending motion occurs through the spine/pelvic joints and two thirds through the hip joint.

• After a large spine fusion, 100% of bending motion occurs through the hip joint.

• Proper implant positioning, leg length, and offset can reduce the risk of dislocation.

• Larger femoral head balls and dual mobility can also reduce the risk of dislocation.

Leg Length Inequality

• The risk of a leg length inequality is ~0.5%

• Sometimes the leg has to be lengthened a bit to increase stability, and prevent dislocation

• If a patient is unhappy with their leg length after surgery, the patient can wear a shoe lift or reoperate to change the modular hip components

Infection

• The risk of a post-operative infection is about 0.25% for healthy patients.

• The risk of a post-operative infection is about ~3-4% for smokers.

• The risk of a post-operative infection is about 2-3% for poorly controlled diabetics.

• The risk of a post-operative infection in obese patients range from about 1% with a BMI of 45 to 2-3% with a BMI of 55.

• Additional material from AAOS:

• https://orthoinfo.org/en/diseases--conditions/joint-replacement-infection/

• https://orthoinfo.org/en/treatment/preventing-infection-after-joint-replacement-surgery-video/

Blood Clots

• Patients without a history of blood clots are asked to take a baby aspirin twice a day for 4 weeks

• Low risk patients have a ~0.5% risk of a blood clot while on aspirin.

• Low risk patients have a ~2-3% risk of a blood clot if they do not take their aspirin.

• Patients with a history of blood clots are asked to take a strong blood thinner (Xarelto, Eliquis, etc) for 4 weeks or longer

• High risk patients have a ~2-3% risk of a blood clot while on a strong blood thinner.

• High risk patients can have a very high risk of a blood clot if they do not take their strong blood thinner. (not advisable)

• A blood clot is associated with calf pain, swelling and pain with ankle flexion.

• Early motion, ambulation and ankle pumps can help prevent blood clots.

• Ultrasound can be used to diagnose a blood clot.

• A blood clot can break off and move to your lungs (Pulmonary Embolus).

• Pulmonary Embolus can cause chest pain and difficulty breathing. In rare cases, pulmonary emboli can be fatal.

• Additional material from AAOS:

• https://orthoinfo.org/en/diseases--conditions/deep-vein-thrombosis/

• https://orthoinfo.org/en/recovery/preventing-blood-clots-after-orthopaedic-surgery-video/

Nerve Injury

• Injuries to the Sciatic and Femoral nerve are exceedingly rare.

• Injury to the lateral femoral cutaneous nerve often causes a temporary skin numbness on the side of the thigh in some patients with an anterior hip replacement. This numbness does not

• typically bother patients and returns to normal in a few months

Medical complication

• Although rare, sometimes the stress of having any surgery can trigger medical issues.

• Heart arrhythmias, stroke, GI bleeds, post op ileus and even death have rarely happened after some hip replacements

Implant Loosening

• Orthopedic hip implants are designed with rough surfaces (porous) to allow the bone to grow into these surfaces.

• If recurring motion occurs between the implants and the bone, then fibrous tissue may grow between the implant and bone which can prevent the bone from growing into the implant.

• If implant loosening occurs (micro motion), patients may have “startup” pain.

• Patients with startup pain may have temporary pain with weight bearing after prolonged sitting.

Implant Wearing Out

• Modern hip replacements can last 5-6 decades, but there are no assurances that they will last that long.

• Most hip replacement prior to 2000 had standard plastic polyethylene that would typically wear out after 1-2 decades, cause osteolysis, lead to bone resorption around the implant.

• All modern polyethylene since 2005 has been highly cross linked and does not seem to cause osteolysis

Chronic Pain

• Hip replacements are very successful at relieving hip and groin pain, but few patients can have continued pain after their hip replacement.

• Any patient with continued hip pain more than 12 months after their surgery should consider a complete work up including x-rays, infection work-up (labs), metal suppressed MRI of the hip,

and/or nuclear bone scan.

Functional Problems

• Hip replacements are very successful at returning function, but few patients can have functional difficulty including limping, stiffness, difficulty putting on their shoes, difficulty with stairs,

and/or weakness.

Abnormal Bone Formation

• Abnormal bone formation (heterotopic ossification - HO) can slowly form around a hip replacement over 1-2 years after a patient’s surgery.

• The risk of HO is ~0.25% of hip replacements.

• HO is usually painless but can restrict hip motion.

• Occasionally, we will have to surgically remove the HO years after a hip replacement.

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The risk percentages discussed above are estimates for primary hip replacements. The risks for revision hip surgeries are often double those of primary hip replacements.