Hip replacement patients can skip hip precautions, study suggests

"The majority of patients we see are low risk; 90% of patients probably qualify for minimized precautions," said Peter Sculco, MD, the study's lead author and an orthopedic surgeon specializing in hip and knee replacement at HSS.

In the last ten years, surgeons have started favoring the anterior approach for total hip replacement over the posterior approach, because it doesn't involve standard hip precautions. Little data, however, backs the standard hip precautions recommended for the posterior approach. For a posterior approach, standard precautions are not flexing your hip past 90 degrees, not internally rotating your hip more than 10 degrees, using an elevated seat cushion at all times and a grabber for anything that is on the ground, and sleeping on your back for six weeks.

"The precautions can be limiting and cause fear in patients," said Dr. Sculco. "Sleeping on your back is very uncomfortable for many people. You often hear from physical therapists that patients are relieved when they can finally cross their legs and sleep on their side."

The literature showing that hip precautions make a difference in hip dislocation is poor. "The current precautions are based on hip replacements done 25 years ago, and we have changed a lot in terms of improving how we do hip replacements that has given us more confidence in the stability of our hips," said Dr. Sculco. "Our understanding of the dynamic movement of the pelvis and how we put the parts in is much different. The quality of our soft tissue repair and closure at the end of surgery is much more robust."

When patients are on stringent precautions, they are not as active, which can hamper recovery. "If you minimize the hip precautions in an appropriate way, patients focus more on their mobility and recovery and less on the fear of how they turn their leg ten degrees," said Dr. Sculco.

In the new study, researchers retrospectively reviewed all patients undergoing a posterior primary uncemented total hip replacement (total hip arthroplasty) from January 2014 to June 2016 at HSS. Surgeons had the choice to put patients on standard precautions or a pose avoidance protocol, to avoid a single pose, a flexed external rotation position that occurs when a person puts on their shoe or shaves their leg. A total of 1,311 patients met the inclusion criteria for the pose avoidance cohort, and the minimum followup was six weeks. Researchers then matched patients 1:1 in this group to a historical cohort of patients based on age, gender, and body mass index that were treated with standard posterior hip precautions.

Within the first six postoperative weeks, six dislocations occurred in the pose avoidance group (0.46%) compared with seven in the matched group (0.53%), a difference that was not statistically or clinically significant. "Our results suggest that the standard postoperative precautions in patients undergoing total hip arthroplasty through the posterior approach without known risk factors for instability are unnecessary," said Dr. Sculco. "We may find that precautions don't make sense for any of our patients, but we need to look at in a stepwise fashion." Risk factors include neuromuscular issues, such as stroke, Parkinson's disease and lumbar spine fusions.

The study was limited in that it is not a randomized controlled trial, usually the gold standard for dictating a change in practice. "The bottom line of the study is in recent years, we have learned more about interventions that matter after joint replacement and those that don't really have efficacy. In most patients, we got rid of powerful anticoagulants, for example, and we are moving toward a shorter stay and even outpatient arthroplasty for total hip replacement," said Dr. Sculco. "Minimizing precautions and simplifying the postoperative recovery is part of the larger simplification of surgery where we are using more selected resources and interventions for people, instead of blanketing everyone with the same kind of protocols."

Dr. Sculco noted that there is an increasing demand for hip replacement in the United States. "In 2010, there were 310,000 hip replacements in the United States and that number is increasing. Its probably 350,000 if not more now," said Dr. Sculco.