Evidence / Sources / E5
Flanigan DC, Sherman SL, Chilelli B, et al. Consensus on rehabilitation guidelines among orthopedic surgeons in the United States following use of third-generation articular cartilage repair (MACI). Cartilage 2021;13(1 Suppl):1782S-1790S. Vericel-sponsored; two sponsor employees are co-authors. Milestone timing only — no exercise dose of any kind. Full text held
Evidence strength 2 of 5
Modified Delphi consensus · n = 12 surgeons, 4 patient profilesMACI ITSELFDOI / full text →What it can tell you
What experienced US surgeons actually converge on for weight-bearing, range of motion, daily activity, and return to sport after MACI — stratified by lesion location, size, age, and activity. The clearest statement of the patellofemoral/tibiofemoral inversion in print.
What it cannot
Whether any of it is optimal — this is expert opinion formalized by Delphi rounds, not tested protocols. The panel explicitly excluded patients needing osteotomy, so its timelines do not apply to a large fraction of real patellofemoral patients.
Everything on this site that leans on E5 — 143 claims
Stage I · Before [patellofemoral]“Set expectations against the right cohort: patellofemoral repairs recover pain and daily function well, but sport and quality-of-life scores run lower than femoral condyle repairs …”Stage II · Protection“In the first weeks the graft's fixation is mechanically vulnerable; shear is the threat. Studied protocols began passive motion within the first day — protection here means protect…”Stage II · Protection“Continuous passive motion appears in roughly three-quarters of published protocols and the US consensus initiates it within the first day at 0–30°. But no trial has isolated CPM as…”Stage II · Protection [patellofemoral]“Patellofemoral protocols in the consensus permit immediate weight-bearing in a brace locked in extension — the patellofemoral joint is barely loaded near full extension. What gets …”Stage II · Protection [patellofemoral]“Quadriceps activation sufficient for a straight-leg raise without lag.”Stage II · Protection [patellofemoral]“Swelling, catching, locking, or pain — the consensus panel's red flags mandating slower progression.”Stage II · Protection [tibiofemoral]“Tibiofemoral protocols restrict weight-bearing and free up motion — the inverse of patellofemoral. Studied protocols graduated weight over 6–9 weeks while allowing early, comparati…”Stage II · Protection [tibiofemoral]“Swelling, catching, locking, or pain — the consensus panel's red flags mandating slower progression.”Stage III · Loading“The graft is entering its soft maturation window — repair tissue is still measurably changing on imaging at 24 months, and this is the period where progressive compression is thoug…”Stage III · Loading [patellofemoral]“For patellofemoral grafts the consensus progressed unloaded motion toward full active range at six to ten weeks, averaging seven to nine across its patient profiles, while loading …”Stage III · Loading [patellofemoral]“Full passive flexion with no swelling response.”Stage III · Loading [patellofemoral]“Level walking 30 minutes without limp or next-day effusion.”Stage III · Loading [patellofemoral]“The consensus named four signals that mandate a slower progression: swelling, catching, locking, or pain. It set no window for judging them — reading swelling the next morning, rat…”Stage III · Loading [tibiofemoral]“Tibiofemoral readers in this window are still progressing off crutches toward full weight — the studied protocols reached full weight-bearing between 6 and 9 weeks (the accelerated…”Stage III · Loading [tibiofemoral]“Full weight-bearing with a normal gait pattern and confidence walking without crutches — the consensus panel ranked gait quality above pain reduction as the milestone.”Stage III · Loading [tibiofemoral]“The consensus named four signals that mandate a slower progression: swelling, catching, locking, or pain. It set no window for judging them — reading swelling the next morning, rat…”Stage III · Loading · Questions“Is my loaded-flexion cap your judgement for my knee specifically, or the clinic default?”Stage IV · Strength [patellofemoral]“Loaded flexion depth remains the progression variable — patellofemoral pressure climbs steeply as the knee bends under load, so strength work deepens its arc gradually rather than …”Stage IV · Strength [patellofemoral]“Controlled single-leg work through the currently permitted flexion arc with no next-day effusion — depth advances only when the shallower arc is boringly tolerated.”Stage IV · Strength [patellofemoral]“Swelling, catching, locking, or pain — and the opposite error. Cartilage atrophies under unloading in the animal models; excessive self-imposed protection is a real failure mode, n…”Stage IV · Strength [tibiofemoral]“Closed-chain quadriceps work was already established — every protocol in the practice-pattern review that reported it had started by week seven — and this window progresses it towa…”Stage IV · Strength [tibiofemoral]“Unrestricted daily activities carried without swelling response — the consensus placed this as early as three months — before loading progresses toward heavier or longer efforts.”Stage IV · Strength [tibiofemoral]“Swelling, catching, locking, or pain — and the opposite error. Cartilage atrophies under unloading in the animal models; excessive self-imposed protection is a real failure mode, n…”Stage V · Impact“The consensus put running evaluation at 6 months for less complex cases and 8 for more complex; running clearance at 7–9 versus 10–12 months; contact sport at 10–12 months and beyo…”Stage V · Impact [patellofemoral]“Loaded flexion through functional range — stairs, decline walking, controlled landing patterns — without next-day effusion, before any running evaluation.”Stage V · Impact [patellofemoral]“Swelling or pain that climbs after impact sessions rather than settling by morning. And a quieter trap: feeling good at six months is not proof of durable success — mean time to gr…”Stage V · Impact [tibiofemoral]“A quiet knee under full strength loads — normal gait, full motion, no effusion response — before the running evaluation the consensus placed from month six.”Stage V · Impact [tibiofemoral]“Swelling or pain that climbs after impact sessions rather than settling by morning. And a quieter trap: feeling good at six months is not proof of durable success — mean time to gr…”Stage V · Impact · Questions“What specifically do you want to see before you clear me to run — and how much of it is measured rather than dated?”Stage VI · Long horizon [patellofemoral]“A new effusion, catching, locking, or a step-change in pain in a previously settled knee. Failure clusters around the second year, not the first months — late change is a reason to…”Stage VI · Long horizon [tibiofemoral]“A new effusion, catching, locking, or a step-change in pain in a previously settled knee. Failure clusters around the second year, not the first months — late change is a reason to…”Program · Stage II (patellofemoral)“Straight-leg raise, in the brace — The patellofemoral joint is barely loaded with the knee straight; a locked brace keeps it that way while the leg works.”Program · Stage II (patellofemoral)“Passive motion, staged arcs — Gained, never forced. CPM appears in about three-quarters of published protocols; no trial has isolated its dose.”Program · Stage II (patellofemoral)“Active short-arc motion, from weeks 2–4 — Active means your muscles move it; loaded means body weight bends it. Only the first is on the menu this stage.”Program · Stage II (patellofemoral)“Walking in the brace, locked in extension — The near-opposite of the tibiofemoral rule on which variable is rationed. If your surgeon restricted your weight-bearing, theirs wins — …”Program · Stage II (patellofemoral) · Gates“Straight-leg raise with no extension lag”Program · Stage II (patellofemoral) · Gates“Active short-arc motion established on schedule without a swelling response”Program · Stage II (patellofemoral) · Gates“Walking in the brace through the day without escalating pain or effusion”Program · Stage II (patellofemoral) · Slow down if“Swelling, catching, locking, or pain — the consensus red flags mandating slower progression. And calf pain or swelling, fever, or the knee locking are red-flag territory, not slow-…”Program · Stage II (tibiofemoral)“Passive motion, from the first day — Gained, never forced. CPM appears in about three-quarters of published protocols; no trial has isolated its dose.”Program · Stage II (tibiofemoral)“Active flexion, early and unloaded — The near-opposite of the patellofemoral rule: flexion was never the protected variable here; weight was.”Program · Stage II (tibiofemoral) · Gates“Each rung of the weight-bearing ladder carried without a swelling response before the next”Program · Stage II (tibiofemoral) · Gates“Active flexion at 90° by the early weeks and approaching full by week six, gained rather than forced”Program · Stage II (tibiofemoral) · Gates“Straight-leg raise with no extension lag”Program · Stage II (tibiofemoral) · Slow down if“Swelling, catching, locking, or pain — the consensus red flags mandating slower progression. And calf pain or swelling, fever, or the knee locking are red-flag territory, not slow-…”Program · Stage III (patellofemoral)“Passive flexion toward full range — Gained, never forced. Heel slides and wall slides; stop at resistance, not at pain.”Program · Stage III (patellofemoral)“Walking, unaided, level ground — Distance before speed. A limp means the dose was too high, not that you need to push through.”Program · Stage III (patellofemoral) · Gates“Full passive flexion, no swelling response”Program · Stage III (patellofemoral) · Gates“Level walking 30 min without limp or next-day effusion”Program · Stage III (patellofemoral) · Slow down if“The consensus named four signals that mandate a slower progression: swelling, catching, locking, or pain. It set no window for judging them — reading swelling the next morning, rat…”Program · Stage III (tibiofemoral)“Gait, made boring again — A limp is information — the dose was too high, not a thing to push through. Distance before speed.”Program · Stage III (tibiofemoral)“Active flexion to full range — The near-opposite of the patellofemoral rule. Flexion here was never the protected variable; weight was.”Program · Stage III (tibiofemoral)“Cycling, recumbent then upright — Recumbent before upright because it asks less flexion and less compression of the same knee.”Program · Stage III (tibiofemoral)“Closed-chain quadriceps work begins — Weight-bearing exercise produces lower tibiofemoral shear than open-chain — the biomechanical reason protocols start here.”Program · Stage III (tibiofemoral) · Gates“Full weight-bearing with a normal gait pattern and confidence walking without crutches”Program · Stage III (tibiofemoral) · Gates“Full active range of motion, without a swelling response”Program · Stage III (tibiofemoral) · Slow down if“The consensus named four signals that mandate a slower progression: swelling, catching, locking, or pain. It set no window for judging them — reading swelling the next morning, rat…”Program · Stage IV (patellofemoral)“Leg press, deepening the arc — Patellofemoral pressure climbs steeply as the knee bends under load. Depth is earned in this stage, never assumed.”Program · Stage IV (patellofemoral)“Single-leg work through the permitted arc — Symmetry against the other leg flatters both — the uninvolved leg detrains too.”Program · Stage IV (patellofemoral)“Cycling, stationary then outdoor — Seat height sets the flexion arc. High seat, shallow arc; that is the patellofemoral-friendly direction.”Program · Stage IV (patellofemoral) · Gates“Controlled single-leg work through the currently permitted flexion arc with no next-day effusion”Program · Stage IV (patellofemoral) · Gates“Unrestricted daily activities carried without a swelling response”Program · Stage IV (patellofemoral) · Slow down if“Swelling, catching, locking, or pain that climbs through a session — and the opposite error. Cartilage atrophies under unloading in the animal models; excessive self-imposed protec…”Program · Stage IV (tibiofemoral)“Leg press, squats, lunges — the strength block — The patellofemoral program guards flexion depth in this window; this side guards load. Same stage, different dial.”Program · Stage IV (tibiofemoral)“Single-leg work under building load — Symmetry against the other leg flatters both — the uninvolved leg detrains too.”Program · Stage IV (tibiofemoral)“Outdoor cycling, rowing, ellipticals — The canonical protocol moves cardio outdoors here. Its week numbers are convention, not tested doses.”Program · Stage IV (tibiofemoral)“Work and daily load, by demand tier — The canonical protocol places return to work in this window; the demand tiers are the consensus panel's.”Program · Stage IV (tibiofemoral) · Gates“Unrestricted daily activities carried without a swelling response”Program · Stage IV (tibiofemoral) · Gates“Single-leg strength work progressing with a knee that is quiet by the next morning”Program · Stage IV (tibiofemoral) · Slow down if“Swelling, catching, locking, or pain that climbs through a session — and the opposite error. Cartilage atrophies under unloading in the animal models; excessive self-imposed protec…”Program · Stage V (patellofemoral)“Stairs, decline walking, controlled landings — Stair descent under full load is among the highest patellofemoral pressures daily life produces. It is trained here, deliberately, no…”Program · Stage V (patellofemoral)“Heavy strength work, continued — Impact weeks are not a reason to stop lifting. The strength base is what the new load lands on.”Program · Stage V (patellofemoral)“Running, by evaluation then intervals — The consensus explicitly excluded osteotomy patients. If your surgery included one, these timelines apply to you even less — for the most co…”Program · Stage V (patellofemoral)“Sport, tier by tier — Pooled return to sport across cartilage procedures runs about 80% — but in pivoting sports the range is 33–96% returned, and most studies never defined "retur…”Program · Stage V (patellofemoral) · Gates“Loaded flexion through functional range — stairs, decline walking, controlled landings — without next-day effusion, before any running evaluation”Program · Stage V (patellofemoral) · Gates“Running at steady interval volumes with a knee that is quiet by the next morning”Program · Stage V (patellofemoral) · Gates“Each sport tier entered on clearance that was measured, not dated”Program · Stage V (patellofemoral) · Slow down if“Swelling or pain that climbs after impact sessions rather than settling by morning. And a quieter trap: feeling good at six months is not proof of durable success — mean time to gr…”Program · Stage V (tibiofemoral)“Heavy strength work, continued — Impact weeks are not a reason to stop lifting. The strength base is what the new load lands on.”Program · Stage V (tibiofemoral)“Running, by evaluation then intervals — The 9–12-month caution rests on an anecdote the authors label as such: patients running at 6–9 months often reported graft-site pain with mo…”Program · Stage V (tibiofemoral)“Sport, tier by tier — Pooled return to sport across cartilage procedures runs about 80% — but in pivoting sports the range is 33–96% returned, and most studies never defined "retur…”Program · Stage V (tibiofemoral) · Gates“A quiet knee under full strength loads — normal gait, full motion, no effusion response — before any running evaluation”Program · Stage V (tibiofemoral) · Gates“Running at steady interval volumes with a knee that is quiet by the next morning”Program · Stage V (tibiofemoral) · Gates“Each sport tier entered on clearance that was measured, not dated”Program · Stage V (tibiofemoral) · Slow down if“Swelling or pain that climbs after impact sessions rather than settling by morning. And a quieter trap: feeling good at six months is not proof of durable success — mean time to gr…”Program · Stage VI (patellofemoral) · Slow down if“A new effusion, catching, locking, or a step-change in pain in a previously settled knee. Failure clusters around the second year, not the first months — late change is a reason to…”Program · Stage VI (tibiofemoral) · Slow down if“A new effusion, catching, locking, or a step-change in pain in a previously settled knee. Failure clusters around the second year, not the first months — late change is a reason to…”Exercise Library · Straight-leg raise, in the brace“Straight-leg raises in a brace locked in extension appear across published patellofemoral protocols and in the US expert consensus as early-stage extensor work.”Exercise Library · Passive motion, staged arcs“Continuous passive motion appears in roughly three-quarters of published cartilage-repair protocols, beginning at 0–30° within the first day in the US expert consensus and the cano…”Exercise Library · Active short-arc motion“The US expert consensus begins patellofemoral active range of motion at 2–4 weeks as a short 0–30° arc, widening stepwise week by week.”Exercise Library · Active flexion, early and unloaded“The canonical tibiofemoral protocol works active-assisted flexion within 30° in the first week, 90° by weeks 2–3, and beyond 125° by weeks 4–6, with full active flexion generally p…”Exercise Library · Walking in the brace, locked in extension“Immediate weight-bearing as tolerated, in a brace locked in extension, is the patellofemoral position in the US expert consensus and the published protocol literature.”Exercise Library · Walking in the brace, locked in extension · Cautions“Where a surgeon has restricted weight-bearing after a patellofemoral repair, that instruction outranks the consensus position — concomitant procedures and how the graft was fixed a…”Exercise Library · Passive flexion toward full range“Recovering unloaded flexion through weeks 6–12, while loaded flexion stays restricted, is the patellofemoral pattern in the US expert consensus and the published protocol literatur…”Exercise Library · Active flexion to full range“Full active flexion is generally permitted from week 6 in the canonical tibiofemoral protocol, with unweighted rowing-ergometer work as its published assist.”Exercise Library · Walking, unaided, level ground“Unaided walking on level ground in weeks 6–12 is the patellofemoral pattern across the consensus and the published cohorts.”Exercise Library · Gait, made boring again“The US expert consensus ranked a normal gait pattern and crutch-free confidence above pain reduction as the milestone for this window.”Exercise Library · Cycling, recumbent then upright“Stationary cycling begins at 3–6 weeks in the US expert consensus. The canonical tibiofemoral protocol starts recumbent on a modified crank once 90° of active flexion allows a full…”Exercise Library · Leg press, deepening arc“The expert consensus progressed patellofemoral loading by opening restricted flexion in steps rather than lifting the restriction at a date, and published protocols describe the sa…”Exercise Library · Leg press toward functional load“Terminal knee extension, leg press, and functional squats and lunges are the canonical tibiofemoral protocol's strength block for the three-to-six-month window.”Exercise Library · Single-leg work“Knee extensor deficits were still measurable five years after the operation, and the authors reporting limb symmetry values cautioned that symmetry can overestimate knee function.”Exercise Library · Cycling, progressive“The expert consensus permitted stationary cycling well before outdoor cycling, and placed outdoor cycling later for more complex patellofemoral profiles than for single lesions.”Exercise Library · Low-impact cardiovascular work“The canonical tibiofemoral protocol introduces outdoor cycling, rowing and elliptical work from around twelve weeks, in the same window it stops relying on hydrotherapy.”Exercise Library · Returning to work“The expert consensus placed sedentary work at two to four weeks, unrestricted daily activities from around three months, and heavy labour at three to six months for less complex ca…”Exercise Library · Stairs, decline and landing“The expert consensus ordered patellofemoral re-entry by joint demand, placing loaded-flexion patterns before any running evaluation rather than alongside it.”Exercise Library · Running progression“The expert consensus placed running evaluation at six months for less complex cases and eight for more complex and clearance at seven to nine months for less complex cases and ten …”Exercise Library · Returning to sport“Pooled return to sport after cartilage repair procedures is about eighty per cent, but in pivoting sports the reported range runs from a third to nearly all patients returning, wit…”Benchmarks · flexion milestones“Short 0–30° arc begins — patellofemoral, active”Benchmarks · flexion milestones“90° by week 4, widening ~15°/week — patellofemoral, active”Benchmarks · flexion milestones“Full active range, 6–10 weeks — patellofemoral, active”What we don't know · № 01“There is no randomized rehabilitation evidence for patellofemoral lesions.”What we don't know · № 13“No formal consensus statement on cartilage repair rehabilitation exists.”What we don't know · № 14“No study ever compared an earlier return — to running, work, or sport — against a later one.”What we don't know · № 17“There is no data on driving after cartilage repair — and the borrowed numbers probably run optimistic here.”What we don't know · № 19“No rehabilitation protocol of any kind addresses a knee with grafts in both compartments at once.”Multifocal disease · lesions in both compartments — why this site has a combined mode“The two locations' rehabilitation programs protect opposite things: the tibiofemoral protocols restrict weight-bearing while allowing motion, and the patellofemoral consensus allow…”Week ruler · week 2 (patellofemoral)“Active range starts later on this side than on the other one, and starts small — a 0–30° arc, widening stepwise rather than all at once.”Week ruler · week 4 (patellofemoral)“The consensus widens the arc by roughly fifteen degrees a week to ninety by week four, and then stops giving week numbers — from here it is as tolerated.”Week ruler · week 7 (tibiofemoral)“Twelve surgeons agreed a tibiofemoral reader reaches full weight across these three weeks. It lands between the two randomized arms without settling them — and the panel excluded a…”Week ruler · week 6 (patellofemoral)“The consensus gives a four-week window rather than a week, averaging seven to nine across its patient profiles — and never says what full range is in degrees. Arriving at the late …”Week ruler · weeks 6–10 (patellofemoral)“Full active range, somewhere across weeks 6 to 10”Hard limits · stage 1 (patellofemoral)“Nothing bends the knee while it is carrying you”Hard limits · stage 1 (patellofemoral)“Weight through this leg is authorised, never assumed”Hard limits · stage 1 (patellofemoral)“No stairs under load, no deep sitting, no rising from low chairs on this leg”Hard limits · stage 2 (patellofemoral)“Full weight is a clearance, not a date”Hard limits · stage 2 (patellofemoral)“Loaded bending stays shallow; unloaded range does not”Hard limits · stage 3 (patellofemoral)“The arc opens in steps, and loaded work stays behind it until it does”Hard limits · stage 1 (tibiofemoral)“Never more weight than the percentage you were given”Hard limits · stage 4 (patellofemoral)“No running, no repetitive impact, until it is cleared”Hard limits · stage 4 (tibiofemoral)“No running, no repetitive impact, until it is cleared”Hard limits · stage 4 (patellofemoral)“No pivoting or cutting”Hard limits · stage 4 (tibiofemoral)“No pivoting or cutting”Why this · Why you can walk on it almost immediately, and still not bend it under load“For a patellofemoral graft the consensus allowed immediate full weight-bearing in a brace locked in extension, while staging range of motion more slowly than the tibiofemoral side …”Why this · Why the joint is moved from the first day, and why nobody knows how much“Continuous passive motion appears in roughly three-quarters of published protocols and the consensus starts it within the first day at a short arc, moving the joint without asking …”Why this · Why you are on crutches for weeks, and bending freely the whole time“On the tibiofemoral side weight was graduated over roughly six to nine weeks in the studied protocols, while range of motion started immediately and progressed comparatively freely…”Why this · Why the joint is moved from the first day, and why nobody knows how much“Continuous passive motion appears in roughly three-quarters of published protocols and the consensus starts it within the first day at a short arc, with early active range beginnin…”Why this · Why depth is the thing being rationed here, and weight is not“The patellofemoral joint is barely loaded with the knee near full extension, and the load rises steeply as the knee bends under weight — which is the opposite of the tibiofemoral s…”Why this · Why the cap here is on load, not on depth“Full active flexion is generally permitted from week six in the canonical protocol, while closed-chain work stays shallow and two-legged — load advances before depth does, which is…”Why this · Why walking normally is a milestone, and ranked above pain“The consensus panel ranked a normal gait pattern and confidence walking without crutches above pain reduction among the milestones it prioritised.”Why this · Why the arc opens in steps rather than lifting on a date“The consensus progressed patellofemoral loading by opening restricted flexion in steps rather than by lifting the restriction at a fixed point, and the canonical protocol places it…”Why this · Why the strength gets measured, and why work comes back by demand rather than by date“The consensus placed unrestricted daily activities from around three months and heavy labour at three to six months for less complex cases against nine to twelve for more complex o…”Why this · Why impact is the last thing to come back, and why the two timelines disagree“The consensus placed running evaluation at six months for less complex cases and eight for more complex, with clearance at seven to nine months against ten to twelve — while the ca…”Why this · Why impact is the last thing to come back, and why the two timelines disagree“The consensus placed running evaluation at six months for less complex cases and eight for more complex, with clearance at seven to nine months against ten to twelve — while the ca…”
Read it like a sceptic
Twelve surgeons, one country, >75% agreement threshold — consensus measures convergence, not correctness.
Tier 1 as consensus statements go; still opinion at the bottom of the evidence pyramid for any specific number.
Population
MACI, knee
Selection policy
Sources enter the registry through docs/research — the evidence table records design, population, and size for every entry, and pages cannot cite anything outside it.