Video Prehab Before Knee Replacement: Faster Early Recovery

A video call can deliver useful prehab before knee replacement. In a 2021 randomized trial, patients awaiting bilateral total knee arthroplasty who completed three weeks of remote exercise improved muscle strength, knee range of motion, and functional performance before surgery and at six weeks afterward. The finding matters for people who cannot easily get to a physical therapy clinic.

It also needs a boundary: prehab appears to speed the first phase of recovery, not improve where patients finish. Across the broader trial literature, control groups caught up by three months after surgery. Think of prehab as arriving at the starting line better prepared, not as buying a different finish line.

What the video-based trial actually tested

Jungae An and colleagues' 2021 randomized controlled trial enrolled 60 adults aged 65 to 75 who were awaiting bilateral total knee arthroplasty. The single-blind study assigned participants to telerehabilitation, patient education, or standard care, leaving about 20 people in each group.

The telerehabilitation program was demanding but short: 30-minute sessions twice daily, five days per week, for three weeks—a total of 30 sessions delivered remotely. Researchers assessed strength, range of motion, and functional performance at baseline, one day before surgery, and six weeks after surgery. The telerehabilitation group improved on these measures relative to the control groups.

This is direct evidence that structured preoperative exercise can work through a remote format. It does not prove that video prehab equals in-person prehab. The trial was too small to establish non-inferiority, and participants had to be familiar with smartphone apps. That requirement leaves out some older adults who may have the most trouble accessing conventional care and digital care alike.

The larger evidence supports early gains

The video trial fits a larger pattern. A 2021 systematic review and meta-analysis by Dun Wang et al. pooled 12 randomized trials with 889 participants. Compared with control conditions, preoperative exercise improved knee-flexion range of motion by 4.28 degrees (95% confidence interval [CI], 2.28 to 6.28; P<0.0001). It improved quadriceps strength by 1.86 units (95% CI, 0.58 to 3.15; P=0.005).

The pooled analysis also found lower WOMAC pain and function scores by 10.59 points (95% CI, −11.88 to −9.29; P<0.00001), faster timed standing and walking performance by 1.29 seconds (95% CI, −1.90 to −0.67; P<0.001), and higher quality-of-life scores by 1.66 points (95% CI, 1.13 to 2.20; P<0.00001). These are statistically significant pooled differences across several related measures.

Statistical significance does not automatically settle clinical importance for every patient. The studies used different exercise programs, durations, intensities, supervision levels, and outcome measures. The meta-analysis combined programs lasting roughly three to eight or more weeks, so it cannot identify a minimum effective dose or declare one exact routine best. The available summary also does not report a publication-bias assessment, which limits confidence in any evidence base dominated by relatively small trials.

The benefit has an expiration date

The most useful corrective comes from a 2022 systematic review by Dimitrios Vasileiadis et al., which examined 24 randomized trials of preoperative physiotherapy before total knee arthroplasty. It found early improvements in functional performance and reductions in hospital length of stay. But every included study that assessed outcomes between three and 12 months found no lasting advantage for prehab in knee motion or patient function.

That does not erase the early benefit. The first several weeks after knee replacement are hard, and better quadriceps strength, motion, and basic function can make that period more manageable. But a claim that prehab improves one-year function would go beyond the evidence. The best-supported claim is narrower: it accelerates early recovery.

Can an unsupervised home program help?

A small 2025 study offers a useful but weaker clue. Monika Mets and colleagues followed 18 women with severe knee osteoarthritis, defined as Kellgren-Lawrence grade III or IV, through an eight-week unsupervised home exercise program before arthroplasty. Participants showed improvements before surgery in leg-extensor strength, WOMAC scores, visual analog scale pain ratings, gait timing measures, ground-reaction forces, and knee-extension moment during the loading-response phase of walking.

The instrumented gait findings are interesting because they measure how the leg loads during walking rather than relying only on questionnaires. Still, this was a pre-post study with no randomized control group. Symptoms and performance can fluctuate; regression to the mean and measurement variation remain possible explanations. The all-female sample and severe-osteoarthritis population also limit how broadly the results apply.

In other words, home exercise is plausible and may help, but this study cannot establish that the program caused each observed improvement. The randomized evidence carries more weight for the core conclusion that prehab improves early outcomes.

Why remote delivery is plausible, but not fully settled before surgery

Evidence after surgery supports the idea that remote exercise can work for knee-replacement patients. A 2025 randomized trial by Akın Süzer et al. tested telerehabilitation-delivered core stability exercises after total knee arthroplasty and found improvement in patient-reported and performance-based outcomes. Its postoperative design means it cannot answer the prehab question directly, but it shows that this population can use remote exercise programs.

A 2025 systematic review and meta-analysis by Shaoyang Zhai et al. similarly found that smart device-assisted telerehabilitation after total knee arthroplasty matched or exceeded conventional rehabilitation across key outcomes. And 2021 activity recommendations by Luc Fortier and colleagues advise a formal unsupervised activity program for all patients recovering from knee or hip arthroplasty; some patients do as well with unsupervised as supervised rehabilitation, while others still need direct support.

Those postoperative findings strengthen the case for remote prehab when travel, cost, or clinic access is a barrier. They do not fill the central preoperative gap. No study here directly compares adherence to video or home prehab with adherence to supervised clinic prehab, and only An et al.'s small trial directly tests telerehabilitation before surgery.

What to do with this evidence

If you are scheduled for total knee arthroplasty, discuss a structured preoperative exercise plan with your surgeon or physical therapist. The evidence supports three to eight weeks of prehab as a way to improve strength, motion, and function before surgery and during early recovery. A video-based program is a reasonable access option, especially when in-person therapy is impractical.

Prehab earns its place if your goal is a better first six weeks after knee replacement. It has not shown that it changes knee motion or function three to 12 months later.

Choose the delivery format you can safely follow and that fits your clinical needs. People with poor independent function, difficulty using technology, or complications that limit exercise may need closer supervision. The evidence supports preparation, not a promise of superior long-term outcomes.