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Pain, fatigue & chronic conditions

Where you do rehab matters less than most people think

Randomized trials on knee replacement and ACL tears tested inpatient stays, video therapy, prehab and rehab-first plans. Here is what held up, what didn't, and what to ask.

By the Health Research USA editorial team

Published Last updated October 2026

Written from the sources listed below; links checked October 2026. It touches on medicines, doses or health conditions and has not yet been reviewed by a licensed clinician, so use it to prepare for a conversation with yours. How we research and review

Sources22, listed below Reading time16 minutes
On this page
  1. Inpatient, home or a screen: what the setting trials found
  2. Prehab: a head start that fades
  3. ACL tears: the trials that tested rehab first
  4. Back to sport: time, strength and tests nobody has validated
  5. Questions to ask about a rehab plan
  6. When to get help now, not at the next visit
  7. The one thing to take away

The knee replacement went well, the surgeon says. Then comes the question families argue about in the hospital corridor: should Mom spend ten days in an inpatient rehab unit, where therapists can watch her every step, or go straight home with an exercise program?

Most people assume more supervision is the safer bet. A trial in Sydney, Australia, tested that. Among 165 people recovering from an uncomplicated knee replacement, ten days of inpatient rehab changed how far they could walk in six minutes, half a year later, by about one meter. Statistically, that is indistinguishable from no difference.

That result sums up a lot of the rehabilitation research after joint surgery and knee injuries. Where rehab happens tends to matter less than people expect. What gets done, how it progresses and when the next step comes may matter more, but those are also the places where the evidence is thinnest.

Medicare’s rules and price tags for each rehab setting are laid out in our overview of what rehabilitation covers, and the normal ups and downs of healing in our piece on recovery after injury. This one is about what the trials found.

Inpatient, home or a screen: what the setting trials found

The Sydney study, called HIHO and published in JAMA in 2017, ran at two public hospitals. Of the 165 patients randomly assigned, 81 got ten days of inpatient rehabilitation followed by an eight-week home program that clinicians monitored. The other 84 went home with the monitored program alone. Their average age was about 67.

At 26 weeks, the two groups walked the same distance on the six-minute walk test. Their scores on a knee pain and function questionnaire differed by about 2 points, under the 5-point change patients can feel. The inpatient group logged 12 complications after discharge, against 9 in the home group. The authors’ conclusion was blunt: “These findings do not support inpatient rehabilitation for this group of patients.”

Note the last four words. HIHO enrolled people with uncomplicated knee replacements. It says nothing about recovery from a stroke, a hip fracture or a complicated operation, or about someone who lives alone with stairs and no help.

The American Academy of Orthopaedic Surgeons points the same way on weaker evidence. Its knee replacement guideline, adopted in December 2022, includes an option statement that going home, with or without home services, is associated with fewer adverse events than discharge to an acute rehabilitation facility or skilled nursing facility. The academy rates the evidence low and the statement limited, and it is an association: people sent to facilities are often sicker to begin with. None of the guideline’s 16 recommendations and 7 options addresses prehab or how therapy after surgery should be delivered.

Video and remote rehab

The VERITAS trial, run at four sites in North Carolina and published in 2020 in the Journal of Bone and Joint Surgery, tested a newer idea. After knee replacement, 306 patients were randomly assigned either to standard physical therapy at home or in a clinic, or to a virtual program: an on-screen avatar coach, 3-D motion tracking at home, and a physical therapist overseeing progress remotely.

The virtual program held its own on a standard knee questionnaire at 6 and 12 weeks. Median costs in the 12 weeks after the hospital were $1,050, against $2,805 for usual care, and there were 12 rehospitalizations against 30. But 19.4% of the virtual group reported a fall, compared with 14.6% of the usual-care group. That gap was not statistically significant, but the trial could not rule out a higher fall risk with virtual rehab, and falls were not among the outcomes on which it was shown to be no worse. Two of the authors listed affiliations with a private health technology company, a potential conflict of interest.

The broadest look so far arrived in August 2026. A meta-analysis in the Journal of Medical Internet Research, led by orthopedic researchers at West China Hospital of Sichuan University, pooled 23 randomized trials with 2,607 people comparing two-way remote rehab after knee replacement with conventional care. Across pain, function, mobility and quality of life, remote rehab showed no statistically significant advantage, apart from a very small early gain in straightening the knee. Nine of the 23 trials were at high risk of bias, and certainty was mostly low to very low. The authors’ framing is the useful one: remote rehab has not been shown to be superior, but it may be a workable model where in-person care is hard to reach.

For Medicare patients the calendar matters. The telehealth FAQ from the Centers for Medicare & Medicaid Services, updated in October 2026, says physical therapists, occupational therapists and speech-language pathologists can bill Medicare for telehealth through December 31, 2027, and that patients can receive those visits at home. Starting January 1, 2028, the FAQ says, therapists can no longer furnish Medicare telehealth services. The current window comes from a two-year extension Congress passed in February 2026, according to the American Physical Therapy Association.

Graded with the library’s five verdicts, inpatient rehab as a way to improve walking after an uncomplicated knee replacement was tested and not supported. Remote rehab as an equal to in-person care has positive evidence with a contested interpretation, given low-certainty data and the open question about falls.

Prehab: a head start that fades

Prehabilitation, or prehab, means exercise and sometimes education in the weeks before an operation. Some of the benefit is real. It is smaller and shorter-lived than most people expect.

A 2025 overview in the Journal of Orthopaedic & Sports Physical Therapy gathered 3 systematic reviews and 21 meta-analyses of prehab before hip and knee replacement, covering 19 hip trials with 1,110 patients and 46 knee trials with 3,362. Prehab was linked to fewer complications and better strength, function and quality of life. But the effects shrank over time and were generally confined to the first six months after surgery. More training volume did not bring better results, and the underlying evidence ranged from critically low to moderate quality.

Two 2026 analyses are more cautious still. A network meta-analysis from Radboud University Medical Centre in the Netherlands compared eight kinds of prehab across 20 trials and 1,095 knee-replacement patients. At three months after surgery, none beat standard care on function, quadriceps strength, pain or quality of life. Leg strength training did improve quadriceps strength at four to eight weeks, on low-confidence evidence.

A second review of 38 trials and 2,332 people, published in October in Research in Nursing & Health, found no clear benefit on patients’ own ratings of early function. Performance tests of early function leaned toward prehab on average, though that estimate was unstable. Prehab patients were 1.57 seconds faster on the Timed Up and Go, a timed test of rising from a chair, walking a short distance and sitting back down. Only two of the trials measured frailty with a validated tool, so whether frail patients gain more is simply unknown.

Then there is the long view. In a US trial cohort analyzed in the Journal of Arthroplasty in October 2026, 135 knee-replacement patients wore activity monitors before surgery and for two years after. Daily steps rose about 8% on average. Yet only 53% to 56% got back to their own pre-surgery activity levels, and the people who had been most active beforehand were the least likely to get there. It was an exploratory analysis, but the team, led from the University of Colorado, drew a pointed conclusion: knee replacement and current rehab may not fully address physical activity.

The trade-off: prehab costs time, travel and sometimes copays before surgery, in exchange for a modest, early edge. Whether that is worth it for one person depends on fitness, frailty and the wait for surgery, a question for the surgeon and physical therapist together.

ACL tears: the trials that tested rehab first

The anterior cruciate ligament, or ACL, runs through the middle of the knee and keeps the shinbone from sliding forward and twisting. Many people assume a torn ACL means reconstruction surgery, full stop. Two randomized trials say the choice is wider.

In the Swedish KANON trial, 121 active adults aged 18 to 35, average age 26, with a fresh ACL tear all got the same structured rehabilitation. Half were assigned reconstruction within ten weeks. The other half did rehab alone, with surgery offered later if the knee became symptomatically unstable and a pivot-shift test, an exam that checks for rotational slipping, confirmed it. After two years, both groups had improved by nearly identical amounts on a knee symptom and function score: 39.2 versus 39.4 points out of 100.

At five years, reported in the BMJ in 2013, there was still no difference in symptoms, function, activity level, arthritis on X-ray or meniscus surgery. Thirty of the 59 people in the rehab-first group, 51%, had eventually chosen reconstruction, seven of them between years two and five. The other 29 never had it.

Two details from the full five-year report rarely make headlines. Knees in the rehab-first group were often looser on exam: only a third had a normal Lachman test, which checks how far the shin slides forward, against about three-quarters in the early-surgery group. That looseness did not show up in how people rated their knees. And in both groups, only about one person in five was back at their pre-injury activity level.

The Dutch COMPARE trial, published in the BMJ in 2021, enrolled 167 people aged 18 to 65, average age 31. Early reconstruction was compared with three months of rehab followed by surgery if needed. Half the rehab group, 41 people, had reconstruction within two years. The rehab group scored better at three months; by nine months the early-surgery group had pulled ahead. At two years the early-surgery group’s knee score was 5.3 points higher on a 100-point scale, a statistically significant gap whose clinical importance the authors called unclear.

The surgeons’ professional body weighs timing differently. The American Academy of Orthopaedic Surgeons’ 2022 ACL guideline says that when surgery is indicated for an acute isolated ACL tear, early reconstruction is preferred, because the risk of additional cartilage and meniscus damage starts to rise within three months. It rates that evidence high and the recommendation strong. KANON, for its part, found no difference over five years in the number of knees that needed meniscus surgery, though in an exploratory count that included repeat operations on the same meniscus, the early-surgery group had fewer meniscus procedures. The same guideline notes that older, less active patients may do well without surgery.

What this adds up to: rehab first, with surgery if needed, is a legitimate strategy for many adults with an ACL tear, and about half of those who try it have surgery anyway. KANON excluded professional athletes and people who were less than moderately active, so it says little about either group. Which path fits a particular knee, sport and tolerance for a possible second decision later is a conversation for an orthopedic surgeon and a physical therapist together.

Whether physical therapy can stand in for surgery for worn meniscus tears, narrowed spinal canals and arthritic knees rests on a different set of trials, which our physical therapy article weighs.

Back to sport: time, strength and tests nobody has validated

The most repeated number in ACL recovery is six months. The reinjury evidence points later.

A 2016 meta-analysis in the American Journal of Sports Medicine, from University of Cincinnati researchers, pooled 19 studies of people who had ACL reconstruction. Overall, 15% went on to a second ACL injury, 7% in the same knee and 8% in the other one. Among athletes younger than 25 who returned to sport, the figure was 23%, nearly one in four.

The Delaware-Oslo ACL cohort followed 106 people from pivoting sports for two years after reconstruction. Those who went back to the most knee-demanding level of sport had a knee reinjury rate 4.3 times higher than those who did not. For each month that return was delayed, up to nine months after surgery, the reinjury rate fell by about half. After nine months, waiting longer brought no further drop. More even quadriceps strength between the two legs before returning also lowered reinjury.

That study’s title advertises that simple decision rules can cut reinjury risk by 84%. Behind it: 38.2% reinjured among people who failed the return-to-sport tests, against 5.6% among those who passed, with a p-value of 0.075, short of the usual bar for statistical significance. The time and strength findings were significant; the headline number was not.

At Aspetar, a sports medicine hospital in Qatar, researchers followed 158 male professional athletes after reconstruction. Twenty-six, or 16.5%, ruptured the graft, on average 105 days after returning. Those who had not met all six of the hospital’s discharge criteria had about four times the risk. The authors opened by noting that commonly used return-to-sport criteria have not been validated, and a group of professional men cannot validate them for anyone else.

Guidelines say the same in their own words. Aspetar’s 2023 clinical practice guideline on ACL rehab calls exercise the mainstay, names return to running and return to training as key milestones, and states that “there is no evidence on which progression or discharge criteria should be used.” The AAOS guideline says a hop test may be considered as one factor in deciding return to sport, on low-quality evidence, and advises against routine functional bracing after a standard reconstruction because braces confer no clinical benefit. A 2016 consensus of 17 sports clinicians in Bern, Switzerland, called return to sport a continuum rather than a single test day, and the supporting research scarce.

So “cleared at six months” is a calendar date, not a finding. The signals with the best support are time since surgery, about nine months for pivoting sports in one cohort, and how close the injured leg’s strength is to the other leg’s.

After meniscus surgery

The same logic now shapes rehab after meniscus surgery. A 2025 consensus of 67 experts from 14 countries, run by ESSKA, a European society for knee surgery, sports traumatology and arthroscopy, with the American Orthopedic Society for Sports Medicine and the American Academy of Sports Physical Therapy, said rehab after removing part of a meniscus should follow milestones rather than a fixed timetable. After a meniscus repair or reconstruction, both time and milestones should guide progress. The panel was candid about its footing: of 29 statements, 17 earned only the lowest grade.

Questions to ask about a rehab plan

Bring these to the first visit, and again whenever the plan changes.

  1. What milestone moves me to the next phase, and how will we measure it? A good answer names a test or a strength target, not just a week number.
  2. Which parts can happen at home or by video, and what would bring me back in person?
  3. If prehab is on offer, what specific gain is it meant to produce before surgery, and how will we check it?
  4. For an ACL tear: if I try rehab first, what would tell us the knee needs surgery, and when would we decide?
  5. Before cutting or pivoting sport: how strong is my injured leg compared with the other one, and how many months will it have been since surgery?
  6. Who answers questions between visits, and how quickly?

When to get help now, not at the next visit

  • A fall during a home or video program, or a near-fall that shakes your confidence. The VERITAS fall numbers are reason enough to report it promptly; whether to switch to in-person sessions is the supervising therapist’s call.
  • A knee that keeps giving way in ordinary life after an ACL tear managed with rehab. In KANON, symptomatic instability was what triggered the offer of surgery, and it is a question for the orthopedic surgeon.
  • No progress on agreed milestones for several weeks. That is a reason to ask the therapist and surgeon to reassess the plan, not to push harder alone.
  • Signs of infection or a blood clot after surgery, such as fever, a red or draining wound, or a newly swollen and painful leg. Our recovery article covers these in detail. The Centers for Disease Control and Prevention lists trouble breathing, chest pain that gets worse when you breathe deeply or cough, and coughing up blood among the possible signs of a clot in the lungs, and says to seek medical help immediately. Calling 911 is the fastest way to get it.

The one thing to take away

Ask for the milestones. Where rehab happens, how much is supervised in person and whether it starts before surgery have all been tested, and the differences are smaller than most people assume. What no trial can settle is whether your own knee or hip is ready for the next step. That gets measured, not dated, so the most useful question at every stage is how it will be measured.

Sources

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