Scientists have identified a remarkably simple yet powerful indicator for predicting how well a patient will recover from hip replacement surgery: their walking speed. A new study suggests that the pace at which someone can walk before their operation is a key determinant of their surgical outcome and long-term satisfaction.
The Link Between Pace and Post-Op Success
Researchers from Kyushu University in Japan conducted a study involving 483 patients with osteoarthritis, a condition affecting joint cartilage that impacts millions worldwide. All participants were scheduled for total hip arthroplasty, where a damaged hip joint is replaced with an artificial implant. Before surgery, physical therapists measured various factors including pain levels, hip range of motion, lower-limb strength, and crucially, a 10-metre self-selected gait speed under standardised conditions.
The surgeries took place between 2012 and 2018. Years later, in August 2023, researchers followed up with questionnaires to assess long-term results. They used tools like the Oxford Hip Score and the Forgotten Joint Score-12, which measures how aware patients are of their artificial joint in daily life.
Walking Speed Emerges as Top Predictor
Using a machine-learning algorithm to analyse the data impartially, the team sorted patients based on recovery scores. This revealed a distinct ‘excellent outcome’ group who experienced minimal pain, high function, and rarely thought about their new hip. When analysing pre-surgery data to find predictors of belonging to this top group, walking speed was the only significant factor.
Patients who could walk faster than one metre per second (about 2.2 miles per hour) before their operation were nearly six times more likely to achieve an excellent long-term outcome. A speed of 0.7 metres per second was linked to acceptable pain relief and function, but the one metre per second threshold was associated with patients largely ‘forgetting’ about their artificial joint—the hallmark of the best possible result.
A 'Vital Sign' for Surgical Planning
Dr Yuki Nakao, an orthopaedic surgeon and the study's lead author, emphasised the utility of this finding. ‘Its simplicity also makes it a practical measure that clinicians can easily incorporate into their routine preoperative assessment,’ he stated. Walking speed is considered a composite vital sign, reflecting overall leg strength, balance, pain tolerance, and cardiovascular health.
The study further identified that better hip flexibility, stronger hip muscles, and lower pre-operative pain levels were each independently linked to a quicker gait. This highlights modifiable factors that patients and clinicians can work on to improve the chances of meeting the key recovery target.
‘We hope that bringing this knowledge into clinical practice will support better recovery and ultimately improve outcomes for patients undergoing hip replacement surgery,’ added Dr Nakao. The research was published in the Journal of Bone & Joint Surgery.
This finding adds to a growing body of evidence on pre-surgery preparation. A separate 2020 Italian study found that patients who took a brisk walk on the morning of their surgery achieved functional independence days earlier than those who started walking post-operatively, with no added downsides like increased pain.
With over 30 million adults in the US alone affected by osteoarthritis, and hip replacement procedures rising, this simple pre-operative test could become a standard tool for setting recovery expectations and guiding pre-habilitation efforts.
