Risks of Total Hip Replacement

1. Infection
(0.5% in first time hips, 1% in revisions, higher in immune compromised patients)
SYMPTOMS: Pain, swelling, redness, drainage, fever.
CAUSE: bacteria entering wound either at surgery or later via blood stream
TREATMENT: If detected early, within several months, and implants are well fixed, an attempt is made to surgically debride the hip, retain the prostheses and treat with intravenous antibiotics for six weeks.
If not detected early, the implants are loose or the infection is recurrent, the implants are removed, intravenous antibiotics are used for six weeks or longer, and the prosthesis is then reimplanted. In severe cases it may not be possible to reimplant, the patient then develops a false joint usually with some pain and weakness requiring crutches or a walker for life.
PREVENTION: Many efforts are used to minimize the risks of infection: prophylactic antibiotics, use of a “laminar air flow” operating room and use of body exhaust suits by the surgical team.

2. Loosening
(First time hips: approximately 3% in first ten years, 10% by 15 years and 20- 30% by 20 years)
HIGH RISK CASES: Young (< 65 years old), very active patients. Revision cases have higher risk of loosening.
SYMPTOMS: Weight bearing pain.
CAUSE: Cemented Hips: debonding of implant from cement, cement cracking and loss of fixation at the cement bone interface due to poor cement technique or osteolysis (see below item #9).
Cementless Hips: Failure of bone attachment to the implant or loss of bone support due to osteolysis.
TREATMENT: Revision surgery.
PREVENTION: Efforts to decrease wear and therefore osteolysis, as well as efforts to improve bonding of cement or implant to bone.

3. Dislocation
(0.5% in first time hips, 5-10% in revisions)
SYMPTOMS: Sudden severe pain, inability to move leg, abnormal position of leg.
CAUSES: Patient non-compliance with motion restrictions, component malposition, impingement, soft tissue laxity, infection.
TREATMENT: Brace for six weeks. If recurrent, may need revision surgery.
PREVENTION: Strict compliance with motion restrictions.

4. Intraoperative Fracture of Bone
(< 1% in first time cemented hips, 5% first time cementless hip cases,
approximately 10% in revision cases).
CAUSES: Poor bone quality, anatomic variation, problems with fit of cementless implants, difficulty of removal of well fixed implants in revision surgery.
TREATMENT: fixation of the fracture with wires, cables, screws, plates and/or bone grafts.

5. Intraoperative Damage to Blood Vessels, Nerves and Other Soft Tissues
(< 1% in all cases except leg lengthening of >2cm when risk is < 10%)
CAUSES: Stretch, direct injury from surgical tools or implants.
RESULT: Severe. If blood vessel, may cause loss of circulation to limb resulting in amputation or excessive blood loss which can be life threatening. If a nerve, can result in loss of feeling or function of the extremity possibly on a permanent basis.
TREATMENT: Surgical repair may be necessary.

6. Blood Clots (With prophylaxis risk of clinically detected blood clot is
(<5% and risk of pulmonary embolus is <1%, fatal pulmonary embolus is 1 in 5000).
SYMPTOMS: Blood clots: swelling in lower leg not relieved by elevation, pain in calf. Embolus (clot going to lung): shortness of breath, chest pain/tightness.
CAUSE: Increased state of coagulation of blood post surgery, decreased ambulation,
decreased mobility.
TREATMENT: Hospitalization with intravenous and oral anti-coagulation.
PREVENTION: Use of prophylactic agents such as blood thinners, pneumatic compression stockings, exercises, early ambulation, spinal or epidural anesthesia.

7. Leg Length Inequality
(90% of the time leg lengths are within 1/4 inch of being equal,
10% chance of> 1/4 inch inequality)
CAUSES: Anatomic variations, soft tissue laxity, pre-existing large inequalities.
TREATMENT: Use of a shoe lift on short leg if > 1/4 inch inequality. Rarely, revision surgery.

8. Bone Formation in Soft Tissues
(approximately 20% mild, approximately 2% severe).
SYMPTOMS: None unless severe.
CAUSE: Stimulation of surgery or trauma causes cells in soft tissues (mainly muscle) to form bone. Pre-disposed individuals are persons who have formed this before, patients with other diseases such as DISH syndrome or ankylosing spondylolysis and patients with large bone spurs.
TREATMENT: If mild, no treatment because this causes no symptoms. If severe, this can cause pain and decreased motion. In this case, surgical removal and post operative radiation may be indicated.
PREVENTION: In pre-disposed individuals, a single dose of radiation given within the first few days after surgery, is usually preventative.

9. Osteolysis bone loss around implants
(< 1% in first 5 years, 10% by 10 years, 20% by 15 years, 50% by 20 years. Much higher in high risk patients: young, active and overweight).
SYMPTOMS: None until very severe.
CAUSE: Particulates of polyethylene, metal or cement dissect between implant and bone resulting in cellular reaction and bone resorption.
TREATMENT: If detected early, observation with decreased activity, possible surgical debridement with change of head and liner. If detected late, probable revision of implants.
PREVENTION: Avoid excessive high risk activities.

10. Decreased Bowel Function in early Post-Operative Period
(common, but complete shut down - so called “ileus”- is < 5%).
CAUSE: Pain medications, decreased mobility, anesthesia, “stress of surgery”.
TREATMENT: Laxative, stool softener, enema (rarely). If entire bowel shuts down (“ileus”), remove food, IV fluids, possible naso-gastro suction. Rarely is abdominal surgical decompression required.
PREVENTION: Stool softener, laxatives, early mobilization.

11. Post Operative Transient Confusion/Disorientation
(<5%)
CAUSE: Pain medication, anesthesia medication, pre-existing conditions such as dementia and Alzheimer’s.
TREATMENT: Decrease or change medications, protection from self-harm, time, return to familiar surroundings. Usually clears in 2-3 days.
PREVENTION: Judicious use of pain and other medications
.
12. Post Operative Pneumonia
(< 1% unless pre-disposed due to chronic lung problems)
CAUSE: Decreased ventilation.
TREATMENT: Antibiotics and breathing treatment.
PREVENTION: Use of incentive spirometer, coughing/deep breathing, early mobilization.

13. Early Post Operative Decreased Respiration
(< 1%)
CAUSE: Usually pain medication.
TREATMENT: Narcotic antagonist medication, oxygen, rarely intubation and respirator.
PREVENTION: Oxygen, use of oxygen saturation monitor, frequent nursing checks.

14. Heart Attacks and Strokes
(approximately 1 in 1000)
CAUSE: Stress of surgery on pre-disposed individuals.
TREATMENT: Care by cardiologist or neurologist.
PREVENTION: Screening pre-operatively for pre-disposing condition.

15. Fat/Marrow Embolism
(< 1% clinically detected)
SYMPTOMS: Shortness of breath, heart rhythm disturbances, mental confusion, very rarely respiratory failure, coma and death (very rare).
CAUSE: Increased pressure inside the bone during surgical instrumentation causes fat and marrow to be pushed into the venous system going to lungs, heart and brain.
TREATMENT: Oxygen and breathing support.

DISCLAIMER
It is not possible to review all the known risks of total hip replacement surgery. The foregoing is a discussion of the commonly known risks.