Evaluating Outcomes of THA Surgical Approaches with a Portable Gait Analysis System

    Researchers at Hospital for Special Surgery (HSS) have launched a study using a portable gait analysis mat to determine if there are any differences in early outcomes between the posterior and direct anterior approaches to total hip arthroplasty (THA).

    Investigators will test patients’ walking patterns both before and after THA to measure their progress following:

    • Posterior approach THA with small incisions
    • Direct anterior approach THA
    • Robotic-assisted posterior approach THA
    • Robotic-assisted direct anterior approach THA

    The researchers are seeking to determine if a specific technique leads to a quicker recovery in terms of pain relief and walking patterns.

    “There are various surgical approaches for a physician to consider when performing hip replacement, and among those, the direct anterior and traditional posterior have been compared extensively to determine if one approach may be superior to the other,” said Michael Alexiades, MD, an orthopedic surgeon at Hospital for Special Surgery and principal investigator.

    “But there is currently no literature that explores the outcomes of robotic-assisted hip replacement compared to the anterior and posterior approaches. To the best of our knowledge, this study will be the first to compare all 4 approaches in 1 study.”

    The research will focus on how patients fare early in the healing process. They will be evaluated for pain and function before surgery and again 6 weeks after THA.

    Although pain relief may be the number 1 priority for most hip replacement patients, their walking patterns after surgery are also an important indicator of progress. The mobile gait analysis system is a key feature of the study.

    “Patients’ walking patterns are very important. If they are not walking symmetrically or have abnormal patterns because of weakness or another issue, they may be compensating by putting pressure on their spine or other joints,” said Rupali Joshi, PT, PhD, study co-investigator.

    “In addition to objectively analyzing functional outcomes after hip replacement, the system will allow us to tailor a physical therapy program or provide specific exercises to help patients overcome weaknesses and develop a normal walking pattern.”

    Howard Hillstrom, PhD, director Leon Root, MD Motion Analysis Laboratory at HSS, note, “We expect almost everyone to walk without pain in a relatively symmetrical manner 6 to 12 months after hip replacement.

    “By looking at outcomes 6 weeks after hip replacement, we are seeking to determine if one surgical technique enables patients to achieve a more pain-free, natural and symmetrical gait pattern more quickly.”

    The mobile gait analysis system consists of an electronic walkway – the mat – that contains thousands of sensors to analyze various aspects of the way a person walks. It is connected to a laptop computer with special software that measures cadence, speed, step length, and other gait parameters. Data and images of the gait pattern are processed, recorded and stored in the computer. The walking test takes less than 5 minutes.

    Not only is it an exciting technology, but the mobile system is also very convenient, facilitating the collection of data for research studies, according to Dr. Joshi.

    Traditional gait analysis at HSS entailed a trip to the hospital’s Motion Analysis Laboratory at a location outside of physicians’ offices. Because the mat is portable, it can be available right in the physician’s office.

    Investigators seek to recruit a total of 80 patients, with 20 participants in each group for the study. Dr. Alexiades said researchers will seek to launch a larger study at a later date.