Quality, Patient Safety and Healthcare Improvement
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Quality at AAMC

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Hip Replacement

Total Hip Replacement (THR) is an elective surgery. About 180,000 THR procedures are performed annually. With the aging population and the increase in arthritic disease and joint failure, the number of THRs continue to increase. The goals for THR are to relieve pain and improve function.

According to the latest statistics from the Agency for Healthcare Research and Quality (AHRQ), about 60 percent of all of the total hip replacement procedures in the US were performed on women and two-thirds of all of the procedures were performed on individuals older than 65 years of age.

There are two types of total hip replacement performed: primary total hip replacement and revision total hip replacement.

Please note: There is no recommended minimum hospital volume, but some studies have found a direct relationship between hospital volume and quality outcomes.

Several volume-related studies to date have failed to separate elective primary hip replacements from revision operations and emergency procedures for acute fractures of the hip. The expected rate of adverse outcomes depends in part on the age of the patient, severity of the disease, and comorbid conditions.

However, studies have suggested significant relationships between surgeons who averaged fewer than 10 hip replacements annually and outcomes. Patients managed by the low-volume surgeons tended to have higher mortality rates, more infections, higher rates of revision operations, and more serious complications during the hospitalization.

Post-operative complications, such as infections and deep venous thrombosis, have been significantly reduced because of the use of prophylactic antibiotics, anticoagulants, and early mobilization.

Hip Replacement Quality Measures

Annual hospital volume

Studies have shown that there is a relationship between the number of total hip replacement (primary and revision) procedures performed at a hospital and quality outcomes. One study of 70,000 Medicare patients indicated that at hospitals in which more than 100 of the procedures were performed per year, patients had a lower risk of death and selected complications than those treated in hospitals in which ten or fewer procedures were performed per year. (The Journal of Bone and Joint Surgery, November 2001: 83; 1622-1629).

In addition, The 100 Top Hospitals: Orthopedic Benchmarks for Success study, conducted by HCIA-Sachs, found that hospitals that perform the most orthopaedic procedures appear to be doing a better job controlling patient complications and have the lowest death rates. (For 2000 study: Modern Healthcare, February 26, 2001: 14-20).

Some complications are inevitable and hospitals can reach a plateau where additional procedure volume does not reduce the number of complications (Journal of Arthroplasty, September 2004: 19 (6): 694-699).

AAMC performed 406 total hip replacement (primary and revision) procedures in 2008.

Annual surgeon volume

Studies have suggested that the volume of procedures performed by the individual surgeon, rather than the hospital as a whole, has more bearing on the outcomes of total hip replacement. These studies have shown that patients treated by surgeons who perform more than 10 total hip replacement procedures per year had lower rates of mortality and complications, such as deep wound infections and hip dislocations (Arthritis & Rheumatism, September 2002: 46(9); 2436-2444) (Journal of Arthroplasty, 1995: 10(2); 133-140).

Total hip replacement is a safe and effective procedure, however, complications may occur regardless of surgeon or hospital volume and may have more to do with patient characteristics than surgeon or hospital volume (The Journal of Bone and Joint Surgery, September 2005; 87-A: 2133-2146).

66% of AAMC’s orthopaedic surgeons performed more than 10 total hip replacement procedures in 2008.

Board certification of orthopaedic surgeons

A board-certified physician has completed an approved educational training program and an evaluation process including an examination designed to assess the knowledge, skills, and experience necessary to provide quality patient care in that specialty. A specialty certificate is issued by a medical specialty certifying board, which is valid nationwide.

Although certification is not required for an individual physician to practice medicine, most hospitals and managed care organizations require that at least a certain percentage of their staff be “board certified.“ (American Board of Medical Specialties)

All of AAMC’s orthopaedic surgeons are board certified in Orthopaedic Surgery by the American Board of Orthopaedic Surgery.

Average length of stay for total hip replacement

According to the most recent national data from the Healthcare Cost and Utilization Project’s (HCUP) Nationwide Inpatient Sample from the Agency for Healthcare Research and Quality (AHRQ), the average length of stay (ALOS) for total hip replacement was 5.2 days.

In 2008, AAMC’s average length of stay (ALOS) for total hip replacement was 2.92 days, which was better than the ALOS for total hip replacement in the most recent HCUP data.

Antibiotic prophylaxis

According to the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) Surgical Infection Prevention Core Performance Measures patients undergoing hip arthroplasty should receive a prophylactic antibiotic within one hour prior to the surgical incision being made.

Surgical site infections affect approximately 500,000 persons per year according to a Centers for Disease Control and Prevention report. Numerous factors such as age and general health status of persons undergoing surgery can affect rates of infection at any given hospital. One of the National Patient Safety Goals from the Joint Commission on Accreditation of Healthcare Organizations is prevention of health care associated infection.

The Medicare Quality Improvement Community (MedQIC), a national knowledge forum for healthcare and quality improvement professionals, encourages careful selection and use of antibiotics for surgical procedures. The benefits of selective peri-operative antibiotic use have been repeatedly demonstrated since the 1960?s (Archives of Surgery, February 2005;140(2): 174-182).

Also prophylactic antibiotics should be discontinued within 24 hours after the surgery end time.

In the year spanning April, 2005 to March, 2006, 77.03% of AAMC’s total hip replacement patients received prophylactic antibiotics within one hour prior to the surgical incision. 87.47% of AAMC’s total hip replacement patients had their antibiotics discontinued within 24 hours after the surgery end time.

Blood clot prevention

Because of the body?s normal response to surgery and the reduction in activity that usually follows surgery, blood clot (thrombus) formation can be a common complication. A thrombus is a blood clot that blocks a blood vessel and reduces blood flow. A thrombus can also dislodge and travel to other parts of the body, such as the heart, lungs, or brain, causing serious health problems.

Preventive or prophylactic steps can be taken to decrease the chance of developing a blood clot (thrombosis). The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) recommends that a venous thromboembolism (VTE) risk assessment be performed within 24 hours of admission to the hospital or intensive care unit. Treatment options should be evaluated for patients who are at high risk for a thrombus or VTE.

Effective venous thromboembolism prevention options include blood thinning medications, early mobilization and physical therapy, range-of-motion exercises, elastic stockings, and intermittent pneumatic compression devices (The Journal of Bone and Joint Surgery, September, 2005: 87-A; 2097-2112).

At AAMC, one or more types of treatments, such as blood thinning medications, early mobilization and physical therapy, range-of-motion exercises, elastic stockings, and intermittent pneumatic compression devices are available for patients having total hip replacement to help prevent blood clots.

Dedicated orthopaedic services: availability and type

Hospitals programs, processes, and services can have an effect on the length of stay, can prevent complications, and can contribute to improved outcomes for persons undergoing total hip replacements. (Arthritis & Rheumatism, September 2002: 46(9); 2436-2444; Journal of Nursing Care Quality, December 1998: 13(2); 67-76)

AAMC offers a comprehensive program of services for patients undergoing total hip replacements. The following programs and services are available:

  • Dedicated operating room for orthopaedic surgery
  • Dedicated orthopaedic unit
  • Clinical pathways of care/ guidelines for THR
  • Physical therapy available more than once a day
  • Prehospital assessment and patient education programs
  • Discharge planning and coordination with home health programs
  • Dedicated case manager for THR

Inpatient mortality rate for total hip replacement

The mortality rate (measured as a percentage) provides general information about the quality of care delivery, and can be an important quality indicator. However, some hospitals care for patients with a greater severity of illness and therefore may have a higher mortality rate.

Total hip replacement, an elective surgery, has a relatively low mortality rate. The known predictors of in-patient mortality include age, presence or type of hip fracture, and the presence of any significant coexisting conditions.

According to the most recent data available from the Healthcare Cost and Utilization Project's (HCUP) Nationwide Inpatient Sample from the Agency for Healthcare Research and Quality (AHRQ), the inpatient mortality rate for total hip replacement (partial and total) was 1.13 percent.

The inpatient mortality rate for total hip replacement at AAMC was 0.2% in 2007, which is better than the rate for total hip replacement in HCUP's Nationwide Inpatient Sample.

Correct patient, procedure and site

Wrong-patient, wrong-procedure, or wrong-site hip surgeries are uncommon, but they can be avoided altogether by following careful procedures prior to surgery. The following procedures cover broad areas of concern in preventing surgical mishaps; however, there are additional safeguards used by surgical teams that are not listed here.

The first procedure involves review of relevant medical records prior to surgery. These records may contain information that will prevent the need for additional tests, saving time and money. They may also provide vital facts about your health history that your surgical team needs to know. Secondly, according to the Joint Commission Universal Protocol for Prevention of Wrong Site, Wrong Procedure, Wrong Person Surgery, it is recommended that the operating surgeon mark the operative site using a signature or other approved mark.

Extra care should be taken with moist areas that can smear onto another site such as the inside of the thigh, according to a report in Anesthesia and Analgesia (January 2005; 100 (1): 300). Smearing can occur where marked skin touches unmarked skin and the unintended marks may cause confusion about the correct site for surgery.

Lastly, just prior to surgery a final review is performed to ensure that the right patient is having the right procedure on the right body part, with all necessary patient information available. The armband may be checked several times during this process to verify that the team has the correct patient. An opportunity for speaking up is provided during this final review; it is a built-in pause (time-out) to provide an opportunity for anyone on the surgical team to speak up about anything related to the procedure or patient that is questionable.

At AAMC, the following steps are taken to ensure correct-patient, correct-procedure and correct-site for hip surgery: (list steps)

Surgical options for hip replacement

Various materials are used to manufacture hip prosthetics, so patients and surgeons have a wide array of hip implant choices. Likewise, there are options for the surgical approach.

Hip prosthesis (implant) wear and hip socket damage (osteolysis) are common causes for hip replacement revision, so choosing the best artificial hip implant can potentially reduce the need for additional hip surgery and complications. Studies indicate that implants made of ?highly cross-linked polyethylene? (a type of plastic) have superior wear rates when compared to ceramic and metal types of implants (The Journal of Bone and Joint Surgery, September 2005: 87-A (9); 2133-2146).

Each type of implant material may have a specific advantage in particular circumstances. Age and activity level may influence implant selection along with other factors that you and your surgeon can discuss.

Minimally invasive (smaller incision) and computer assisted techniques are also being used by some surgeons. Estimated blood loss has been shown to be significantly lower with the minimally invasive technique. Pain, functional status, and length of hospital stay were not significantly different when minimally invasive surgery was compared in a clinical trial of 219 patients (The Journal of Bone and Joint Surgery, April 2005: 87; 701-710).

At AAMC, the following options are available for hip surgery: (list options)