Injury types

ACL Tears: Surgery, the 9–12 Month Road Back, and Return to Form

Published 2026-10-26 · Daily IL team

This article is general information, not medical advice. For any individual player’s return date, follow the club’s official announcements.

Few injury headlines land as heavily as “torn ACL, out for the season.” An anterior cruciate ligament tear usually means surgery, close to a year of rehabilitation, and often a further adjustment period after the player is back on the field. Here is what fans should know when they see those three letters on an injury report.

What the ACL does

The knee is held together by four main ligaments. The medial and lateral collateral ligaments (MCL and LCL) control side-to-side movement, while the anterior and posterior cruciate ligaments (ACL and PCL) cross in the middle of the joint and control front-to-back movement.

The ACL runs diagonally through the centre of the knee. Its job is to stop the shinbone from sliding forward under the thighbone and to provide rotational stability. Without it, athletes in cutting and pivoting sports often feel the knee “give way” when they change direction.

How it tears

Many fans picture a crunching tackle, but most ACL injuries happen without contact to the knee. The American Academy of Orthopaedic Surgeons (AAOS) describes the typical scenarios as:

stopping suddenly or changing direction at speed,
landing from a jump with the knee nearly straight,
planting the foot and twisting the body over it.

Direct blows, such as a tackle to the side of the knee, cause the rest. Players frequently report a pop, and the knee usually swells within hours. Damage to the meniscus or the MCL often comes along with it; AAOS notes that about half of ACL injuries are combined injuries. Female athletes have been reported to tear the ACL at two to eight times the rate of male athletes.

Surgery or not?

ACL injuries are graded like other sprains: grade 1 (stretched), grade 2 (partially torn) and grade 3 (completely torn). A completely torn ACL rarely heals back together on its own, so most professional athletes undergo reconstruction. Instead of stitching the torn ligament, the surgeon builds a new one from a tendon graft — usually the player’s own patellar, hamstring or quadriceps tendon, or donor tissue.

Non-surgical treatment is a legitimate option for some people: those with partial tears and no instability, or those whose daily life and sport do not involve much pivoting. For athletes in football, basketball, American football and similar sports, however, continuing to play on an unstable knee raises the risk of further damage to cartilage and the meniscus, so surgery is the usual choice.

Timing matters as well. For an isolated ACL tear, AAOS says a 12-week trial of non-operative care is reasonable, and that if surgery is needed it should ideally happen within five months to limit damage to the meniscus and cartilage. For professional athletes, the medical staff weigh swelling, knee motion and any additional injuries when choosing the date.

Path	Usually suits	Typical timeline (rough)
Rehab without surgery	Partial tear, no instability, lower demands	At least about 3 months of rehab
Reconstruction, general patients	Active adults, pivoting sports	6–12 months to full sport
Reconstruction, professional athletes	Most pro players	Commonly 9–12+ months

Why it takes 9–12 months or longer

The operation itself is over in a day, but the new graft needs time to anchor into bone and start behaving like a ligament. Rehab typically moves from controlling swelling and regaining full knee straightening, to rebuilding strength, then running, then cutting and jumping, and finally full team training.

Modern rehab increasingly relies on passing objective tests rather than simply counting months. The Delaware-Oslo ACL Cohort Study, which followed about 100 athletes after reconstruction, found that those who returned to demanding sports before nine months had a reinjury rate of roughly 40%, about double the rate (roughly 19%) for those who returned later. Up to the nine-month mark, each month of delay was associated with a 51% lower reinjury rate. Athletes whose thigh-muscle strength on the operated side was below 90% of the healthy side also reinjured more often. The study is small, but it helps explain why clubs are rarely in a hurry.

Return to play is not return to form

Getting back on the field and getting back to your best are two different milestones.

A meta-analysis of 69 studies and over 7,500 patients (Ardern and colleagues, 2014) found that 81% returned to some form of sport, but only 65% returned to their pre-injury level and 55% to competitive sport. Elite athletes were far more likely than recreational players to make it back to competition.
A 15-year study of men’s professional football clubs (Waldén and colleagues, 2016) found that the return-to-play rate within a year was very high, yet only about two-thirds were still playing at the top level three years later.
A 2020 systematic review of American football players, mostly NFL and top college level, reported a return-to-play rate of about 67% at an average of 11.6 months, with many returning players showing larger performance declines than uninjured peers over the same period.

In practice, the first season after an ACL reconstruction is often treated as a transition year. Explosiveness and confidence in cutting can take time to return, and the risk of a second ACL injury — in either knee — is higher than for players who have never had one.

On Daily IL

On Daily IL, every injury entry lists the body part and injury type — for example “right knee · tear (ACL)” — alongside the status the team has announced: OUT, DOUBTFUL, QUESTIONABLE, PROBABLE, IL (injured list), SUSPENDED or RETURNED. See our status guide for what each one means.

For long-term injuries like an ACL tear, teams often give only a broad window such as “out for the season” or “early next year.” Daily IL reports what the club has said and does not guess at return dates.

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