Hip arthroscopy for arthritis associated with unacceptably high conversion to total hip replacement and significantly worse outcomes

May 18, 2020

The percentage of patients with hip arthritis who had a hip replacement within two years of hip arthroscopy was unacceptably high at 68%, according to a new study of more than 2,600 patients by investigators at Hospital for Special Surgery (HSS). Prior hip arthroscopy was also associated with significantly worse outcomes after hip replacement. 

The researchers found that within two years of having had arthroscopy, about two-thirds of patients with hip arthritis had undergone a total hip replacement. They also found that prior hip arthroscopy was associated with significantly higher risks of revision hip replacement surgery, joint implant loosening and joint infection after hip replacement. 

“Our study is the first to quantify the clinical outcomes and risks of complications from having hip arthroscopy before total hip replacement in patients with osteoarthritis,” says senior author Alexander S. McLawhorn, MD, MBA, a hip and knee surgeon at HSS. “Our results suggest that arthroscopy should be avoided in patients with hip arthritis, especially in those over the age of 65.” 

This study is available online as part of the AAOS 2020 Virtual Education Experience and is currently published online on HIP International.  

The use of hip arthroscopy has increased by more than 600% in the past 10 years. It is a minimally invasive surgical technique that involves the use of an arthroscope, a small fiber-optic tube attached to a camera that allows surgeons to view the hip joint. Surgeons use hip arthroscopy to diagnose joint problems and perform repairs, such as fixing a labral tear, correcting hip impingement or removing loose fragments of cartilage resulting from an injury. 

Some surgeons have also used arthroscopy to treat patients with hip arthritis in an attempt to delay or eliminate the need for a hip replacement. “From previous patient-reported outcomes studies, we have been increasingly recognizing that these ‘clean-out procedures’ are not successful in patients with osteoarthritis. They tend to lead to joint replacements relatively soon after the arthroscopy because they do not solve the underlying problem,” says Dr. McLawhorn. 

For their study, the investigators examined Medicare data from a large national insurance database called the PearlDiver Patient Records Database. They identified more than 5,200 patients with hip arthritis who had undergone a total hip replacement procedure between 2005 and 2016 and grouped them according to whether they had received hip arthroscopy before hip replacement. After matching to ensure there were no differences between groups in age, sex, smoking status, obesity or other health conditions, each group contained data for 2,600 patients. A majority, 82%, were over the age of 65. 

Overall, a total of 1,790 (68%) patients who had received hip arthroscopy to treat osteoarthritis had undergone a total hip replacement procedure within two years. Patients who had a prior hip arthroscopy had 3.7 times greater risk of needing revision hip replacement surgery, 2.8 times greater risk of implant loosening and 1.9 times higher risk of joint infection after hip replacement, compared to patients who had not had hip arthroscopy prior to their hip replacement. 

Within two years of total hip replacement, 3.4% of patients in the arthroscopy group required revision surgery compared to 2.1% in the non-arthroscopy group. In the same period, rates of complications were higher for the arthroscopy group compared to the non-arthroscopy group as follows: dislocation 3.2% versus 2.3%; joint infections 2.9% versus 1.6%; and joint loosening 2.3% versus 1.0%, respectively. 

“These risk percentages may seem small, but they are critically important. The goal is to drive complications down to as close to zero as possible,” says Dr. McLawhorn. “No patient should undergo an unnecessary procedure, even if the downstream risk of a complication is small. A joint replacement infection, for example, is a life-altering event.” 

HSS has the report