Knee

What Actually Prevents Knee Pain in Young Athletes: The Growing Knee, Osgood-Schlatter, Osteochondritis Dissecans and the Case Against Early Specialisation

Most knee pain in adolescents is the growing skeleton reacting to load, and most of it settles on its own. Here is what the evidence says about the growth-plate conditions, the one that can damage the joint surface, the kneecap that dislocates at 15, and why early single-sport specialisation keeps appearing as a risk factor.

Written by Dr Isa Waheed, MBBS MFSEM

Published 7 September 2026Last reviewed 7 September 202611 min read29 studies reviewed

The adolescent knee is not a small adult knee. It has open growth plates, a kneecap whose lower pole is still maturing, cartilage that is still forming, and a skeleton growing faster than the muscles and tendons attached to it. Load it hard, as young athletes do, and it complains in ways that adults' knees do not.

Most of that complaint is benign and self-limiting. One condition is not. This is the fourth of four detailed guides under our knee hub, and it covers the growing knee: Osgood-Schlatter disease, Sinding-Larsen-Johansson disease, osteochondritis dissecans, the adolescent kneecap, and what the sports injury evidence means when the athlete is 15. The degenerative knee guide, the overloaded knee guide and the sports knee injury guide each cover their own ground.

Key takeaways

Osgood-Schlatter disease affects about one in five sports-active adolescents and around one in ten in football academies. It is roughly five times more common in active than inactive teenagers, and it is a load condition of the growing skeleton.
It resolves. The natural course is about 19 months, with half pain-free by 16 months, and skeletal maturity ends it.
Early single-sport specialisation quadrupled the risk of both Osgood-Schlatter and Sinding-Larsen-Johansson in adolescent girls.
Stretching is widely recommended for Osgood-Schlatter but has never been shown in a trial to prevent it.
Osteochondritis dissecans is the one to take seriously, because it can damage the joint surface and about 39% of people with it develop osteoarthritis. Two thirds of stable juvenile lesions heal with activity modification within six months.
Kneecap dislocation peaks at 14 to 18, and skeletal immaturity is one of the two strongest predictors of it happening again.

Osgood-Schlatter disease: the commonest growing pain of the knee

In general practice the incidence is about 3.8 per 1,000 children per year, peaking at age 12 in boys and 11 in girls [1]. It follows sport. Osgood-Schlatter was about five times more common in sports-active than inactive adolescents (21% versus 4.5%), the standing kicking-support leg was affected in about 70% of footballers, 68% of those with Sever's disease also had it, and siblings were more often affected [2]. Point prevalence in youth football academies is around 10% [3], and in one academy cohort 17%, with 80% reporting no time lost from training [4].

It is a condition of the open growth plate. Osgood-Schlatter was far more common in skeletally immature than mature knees, about 25% versus 5% [5], which is why it ends when growth does.

Osgood-Schlatter: what raises the risk and what does not

Two findings stand out. Adolescent girls who specialised early in a single sport had about four times the risk of Osgood-Schlatter compared with those who played multiple sports [6]. And a previous Sever's disease, the equivalent condition at the heel, carried nearly 17 times the odds [4], pointing to a shared vulnerability of the growing attachment sites rather than anything specific to the knee.

Much of what is commonly blamed does not hold up. Growth rate, BMI and muscle imbalance were not predisposing factors [7], and growth, maturity, flexibility and strength were not associated when compared at the same age [4]. Tight and strong quadriceps and tight hamstrings were associated in one study, though the association is inconsistent across the literature [8].

That matters for the standard advice. Quadriceps and hamstring stretching is widely recommended but has not been shown in a trial to prevent Osgood-Schlatter, and the historical male predominance is narrowing [9].

Osgood-Schlatter: the course, and the one thing to watch

The natural course is about 19 months, with half of children pain-free by 16 months [7]. It is a load condition that runs its course as the skeleton matures, and the practical lever is managing training and match volume through the growth spurt rather than treating the knee.

One downstream risk is worth knowing. Children with Osgood-Schlatter had roughly 15 times the rate of tibial tubercle avulsion fracture, about 627 versus 43 per 100,000 per year, with male sex and obesity adding further risk [10]. It remains rare, but it is the reason a sudden severe pain at the front of the knee in an adolescent with known Osgood-Schlatter deserves assessment rather than reassurance.

Sinding-Larsen-Johansson disease: the same story at the kneecap

Sinding-Larsen-Johansson affects the lower pole of the kneecap rather than the shin bone, and it behaves the same way. Together with Sever's and Osgood-Schlatter it made up over 99% of lower-limb apophysitis in a schoolchild cohort followed for over five years, children playing soccer, handball, basketball and jumping gymnastics had roughly two to nearly three times the risk (RR 2.07 to 2.74), incidence was about 3 to 7 per 1,000 sport-participations, and extra physical education did not raise risk [11]. Organised jumping and pivoting sport drives it; general activity does not.

The evidence base is thinner than for Osgood-Schlatter. It comes mainly from case reports and is limited and at times conflicting; the condition concentrates in physically active boys aged 9 to 17 during the window when the lower pole of the kneecap is still maturing, and is self-limiting over about two to eight months [12]. As with Osgood-Schlatter, adolescent girls who specialised early in a single sport had about four times the risk [6].

Osteochondritis dissecans: the one that can damage the joint

This is where the growing knee stops being benign. Osteochondritis dissecans is a multifactorial subchondral bone disorder combining genetic predisposition with acquired factors, chiefly repetitive sporting microtrauma; it mainly affects children, adolescents and young adults, most often the medial femoral condyle [13].

Incidence in 6 to 19 year olds was about 9.5 per 100,000, far higher in boys (15.4) than girls (3.3) and concentrated in adolescence, with the 12 to 19 age group about 3.3 times the 6 to 11 group, and the medial femoral condyle involved in about two thirds of cases [14]. Moderately obese children had about 1.8 times the risk versus normal-weight children, though overweight, underweight and extreme obesity were not significantly associated [15]. About 14% of children with it had a relative with the condition, far above the general-population rate, supporting a genetic predisposition, though a positive family history did not predict more severe lesions [16]. Identical twins developing lesions in their dominant knees point to repetitive sporting overuse as the environmental trigger [17].

Osteochondritis dissecans: why early management matters

The good news first. About two thirds of stable juvenile lesions healed within six months of activity modification and bracing, with smaller lesions far more likely to heal, and age did not predict healing [18]. Among children cleared to return to activity, some still needed surgery, those who returned sooner tended to progress, and medial femoral condyle lesions were less likely to progress [19]. Patience with return to sport is the prevention here.

The reason it matters is the long-term picture. About 39% of people with knee osteochondritis dissecans develop osteoarthritis; a BMI above 25 raised the risk, fragment excision rather than preservation raised it (RR 1.89), and larger lesions over 4 cm raised it (RR 2.29), while gender, location, stability and surgical versus non-surgical management were not significant [20]. Over 12 years about 45% of knees showed arthritis progression, linked to greater lesion depth, higher BMI and older age, with progression in turn linked to worse knee function [21].

Two of those three modifiable levers are in the family's hands: keep the fragment rather than excise it if surgery is needed, and keep body weight down. The third, lesion size, is why catching it early matters.

The adolescent kneecap and front-of-knee pain

Front-of-knee pain is not confined to the growth plates. Patellofemoral pain has an annual prevalence of around 28.9% in adolescents, with point prevalence reaching about 22.7% in female adolescent athletes [22]. The adolescent risk profile has a twist: across prospective studies, greater hip abduction strength was associated with higher risk in adolescents, while age, height, weight, BMI, body fat and Q angle were not risk factors [23]. That counterintuitive finding is a caution against assuming the adult hip-strength story applies to a growing athlete. The overloaded knee guide covers patellofemoral pain in full.

Kneecap dislocation peaks in exactly this age group. General-population incidence is about 23 per 100,000 per year, rising roughly sixfold in adolescents aged 14 to 18 to about 148 per 100,000 [24]. There is no established primary prevention. In young patients recurrence was about 31% after non-operative care versus 22% after surgery, and skeletal immaturity and trochlear dysplasia particularly raised recurrence [25]. The immature skeleton is itself a risk factor for a second dislocation, which is why a 15-year-old's first dislocation deserves a proper plan rather than a wait-and-see approach. The sports knee injury guide covers dislocation in adults.

Where the sports injury evidence meets the young athlete

The strongest prevention evidence in the knee applies directly to adolescents. Neuromuscular training reduced ACL injury risk in female athletes (OR 0.40), and it worked best when started under age 18, sustained across pre-season and in-season, and built around plyometrics and strengthening rather than balance alone [26]. The largest trial was in 4,564 adolescent female footballers, where a 15-minute neuromuscular warm-up twice weekly reduced ACL injuries by 64%, from 0.67% of players to 0.28% [27]. Starting young is not a compromise. It is when the programmes work best.

The cost of not preventing is also highest in the young. After an ACL injury, the second-injury rate rises to 21% in those under 25 and 23% in young athletes who return to sport, roughly 30 to 40 times the rate of uninjured adolescents [28]. And load counts from the start: in young elite volleyball players, each extra hour of weekly training raised the risk of jumper's knee (OR 1.72), each extra match set per week nearly quadrupled it (OR 3.88), and young males had three to four times the risk of females [29]. The sports knee injury guide has the full ACL evidence.

What changes a young athlete's knee risk

Factor	Condition	Direction	Effect	Can you change it?	Evidence
Sporting activity during growth	Osgood-Schlatter	Raises risk	About 5x inactive peers	Partly	Tier 3
Early single-sport specialisation	Osgood-Schlatter, Sinding-Larsen-Johansson	Raises risk	About 4x multisport peers	Yes	Tier 3
Previous Sever's disease	Osgood-Schlatter	Raises risk	Nearly 17x	No	Tier 3
Open growth plate	Osgood-Schlatter	Raises risk	About 25% vs 5% mature knees	No	Tier 3
Growth rate, BMI, muscle imbalance	Osgood-Schlatter	No effect	Not predisposing	-	Tier 3
Quadriceps and hamstring stretching	Osgood-Schlatter	No proven effect	Not shown in any trial	-	Tier 3
Jumping and pivoting sports	Sinding-Larsen-Johansson	Raises risk	RR 2.07 to 2.74	Partly	Tier 2
Extra physical education	Sinding-Larsen-Johansson	No effect	Did not raise risk	-	Tier 2
Male sex	Osteochondritis dissecans	Raises risk	15.4 vs 3.3 per 100,000	No	Tier 3
Moderate obesity	Osteochondritis dissecans	Raises risk	About 1.8x	Yes	Tier 3
Activity modification (stable lesion)	Osteochondritis dissecans	Promotes healing	Two thirds heal in 6 months	Yes	Tier 2
Early return to sport	Osteochondritis dissecans	Raises progression	Sooner return tended to progress	Yes	Tier 3
Fragment excision rather than preservation	Osteochondritis dissecans	Raises later OA	RR 1.89	Partly	Tier 2
Skeletal immaturity	Patellar dislocation (recurrence)	Raises risk	Recurrence 31% non-op vs 22% surgery	No	Tier 2
Neuromuscular warm-up started under 18	ACL	Lowers risk	OR 0.40; 64% in adolescent footballers	Yes	Tier 1
Match and training load	Patellar tendinopathy	Raises risk	Each extra match set per week OR 3.88	Yes	Tier 2

Where the evidence runs thin

Almost everything on the growth-plate conditions is observational and much of it is small or single-sport. The Sinding-Larsen-Johansson literature rests largely on case reports. No trial has tested stretching, load management or any other measure for preventing Osgood-Schlatter, so the load story is inferred from who gets it rather than proven by changing it. The osteochondritis dissecans evidence is stronger on prognosis than on primary prevention. And the early-specialisation finding comes from adolescent girls in a single cohort, so its size in boys and other populations is not established, even though the direction is consistent with everything else here.

What we would actually do

Let children play more than one sport for as long as possible, because early specialisation is the one modifiable factor that shows up across two conditions. Manage training and match load through the growth spurt rather than treating the knee, and expect Osgood-Schlatter to run its course. Do not rely on stretching to prevent it. Take osteochondritis dissecans seriously: follow the activity modification, be patient with return to sport, and if surgery is ever needed, preserve the fragment. Treat a first kneecap dislocation in a growing athlete as the start of a plan, not a one-off. Start neuromuscular warm-ups before 18, because that is when they work best and the cost of an ACL injury is highest. And take a sudden severe front-of-knee pain in a child with known Osgood-Schlatter seriously, because the rare avulsion fracture is fifteen times more likely in that group.

References

Frequently asked questions

Will Osgood-Schlatter disease go away on its own?

Almost always. The natural course is about 19 months, with half of children pain-free by 16 months, and it ends when the growth plate closes. It is far more common in skeletally immature knees, about 25% versus 5% once mature.

Should my child stretch to prevent Osgood-Schlatter?

Stretching is widely recommended but has never been shown in a trial to prevent it. Growth rate, BMI and muscle imbalance were also not predisposing factors in cohort data. The factors that do show up are sporting load and early single-sport specialisation.

Is it bad for a child to specialise in one sport early?

The evidence points that way. Adolescent girls who specialised early in a single sport had about four times the risk of both Osgood-Schlatter and Sinding-Larsen-Johansson compared with those who played multiple sports. It is the one modifiable factor that appears across two growing-knee conditions.

What is osteochondritis dissecans and why does it matter more?

It is a disorder of the bone just beneath the cartilage, usually on the inner side of the knee, driven by repetitive sporting load on a genetically predisposed joint. It matters because it can damage the joint surface, and about 39% of people with it develop osteoarthritis. Two thirds of stable juvenile lesions heal with activity modification, and preserving rather than removing the fragment lowers later arthritis risk.

Are young athletes too young for ACL prevention programmes?

The opposite. Neuromuscular training worked best when started under age 18, and the largest trial was in adolescent female footballers, where a 15-minute warm-up twice a week cut ACL injuries by 64%. Young athletes also carry the highest second-injury rates after an ACL tear, so the case for starting early is strong.

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About the author

Dr Isa Waheed

MBBSMFSEMBSc (Hons)DipMSKDipExMedDipTCPGCertFHEA

NHS doctor and sport and exercise medicine clinician, translating injury prevention research into guidance people can act on.

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Educational information only. Not medical advice and not a substitute for assessment by a qualified clinician. Seek prompt medical assessment for a knee that locks, gives way, swells significantly, or cannot bear weight, or for any sudden or severe knee injury.