Patellar Tendinitis

The patellar tendon connects the kneecap (patella) to the shin bone (tibia). It plays an important role in the way you use your legs. It helps your thigh muscles (quadriceps) straighten your knee.

The patellar tendon is made of tough string-like bands which are surrounded by a membrane that helps it to glide.

Patellar tendinitis is a condition that occurs when the tendon and membrane become inflamed.

It is usually an overuse injury, commonly associated with jumping activities, which is why it is often called “jumper’s knee”. It is most common in athletes whose sports involve frequent jumping — for example, basketball and volleyball players. However, anyone can suffer from patellar tendinitis.

Alternate name

  • jumper’s knee
Side-on diagram of the knee labelling the femur, quadriceps muscle and tendon, patella, patellar tendon, tibia and fibula

Diagram of the Knee looking from the side

Symptoms

  • Pain at the front of the knee, felt directly over the tendon just below the kneecap. Pressing on it reproduces the pain clearly.
  • Pain brought on by jumping, landing, sprinting, deep squatting or going down stairs
  • Pain at the start of activity that eases as you warm up, then returns afterwards — this pattern is characteristic
  • Stiffness in the knee first thing in the morning or after sitting for a while
  • Pain when kneeling
  • In more advanced cases, pain during everyday activity rather than only during sport

The tendon is not usually swollen, red or warm. If the knee itself is swollen or hot, something else is going on and it should be assessed.

Causes

This condition arises mainly due to overuse of the patella tendon. The causes include:

  • Repetitive or frequent exercise which involves jumping
  • Tight muscles (especially thigh muscles) resulting in extra strain on the patella tendon
  • Anatomical variation in the patella position, in particular a high patella
  • Being overweight puts more force through the tendons

Risk Factors

  • Sports involving repeated jumping and landing — basketball, volleyball, netball, high jump
  • A sudden increase in training volume, intensity or frequency
  • A change in training surface, particularly onto something harder
  • Tight or weak quadriceps, hamstrings or calf muscles
  • Reduced ankle flexibility, which changes how force is absorbed on landing
  • Higher body weight, which increases the load through the tendon on landing
  • A previous episode of patellar tendinopathy — recurrence is common where the tendon was never fully reloaded

Investigations

X-ray looking down on a normal patella where it sits against the femur

An X-ray of a normal Knee looking from the side

X-ray of a normal knee from the side, labelling the femur, tibia, patella and the knee joint

An X-ray of a normal Knee showing the kneecap (patella)

Usually investigations are not required and the doctor can diagnose your condition via physical examination. However, X-rays may be taken to exclude other conditions involving the bones, and an MRI can be done to take a closer look at your tendons.

Complications

Playing on through pain that is worsening risks further damage to the tendon, including, rarely, complete rupture. This is different from the controlled discomfort that is expected during a rehabilitation programme — see Treatment below.

Left unaddressed, the other problems that can arise are persistent knee pain, loss of strength in the quadriceps, and an inability to return to sport at the previous level.

Treatment

Patellar tendinopathy responds to loading, not to rest. The tendon needs to be worked in a controlled, progressive way to recover its capacity. Prolonged rest settles the pain in the short term but leaves the tendon and the thigh muscle weaker, which is why the problem so often returns on going back to sport.1,2

Load management

Reduce the activities that spike the load through the tendon — jumping, sprinting, deep squatting, changing direction — rather than stopping altogether. Cycling, swimming and straight-line walking can usually continue. Reducing training volume is more useful than eliminating training.2

Progressive strengthening

This is the core of treatment and the part that changes the outcome. A physiotherapist will usually take you through stages: isometric holds early on, which often reduce the pain in themselves;3 then slow, heavy strength work;4 then adding speed, and finally jumping and landing before returning to sport.2,5 This takes months rather than weeks, and it has to be done consistently.

What to expect during rehabilitation

Some discomfort while loading the tendon is normal and does not mean damage is being done. The usual guide is that pain should settle within 24 hours and should not be increasing week to week. Pain that is worsening, or that is still high the following morning, means the load was too great for that stage — it is a signal to adjust the programme rather than to stop it.2

Other measures

  • Ice and anti-inflammatory medication can take the edge off a painful flare, but they treat the symptom rather than the tendon and should not replace the loading programme. Long-standing tendinopathy is predominantly a degenerative rather than an inflammatory problem.1
  • Straps and braces give some people symptomatic relief. The evidence for them is limited, but they are harmless to try.
  • Stretching the quadriceps, hamstrings and calves helps if those muscles are tight, but it is not a treatment for the tendon by itself.

If it does not settle

Most people improve with a properly supervised loading programme carried out for long enough. Treatment usually fails because the programme was stopped early rather than because it was the wrong programme. Injections and surgery are considered only in persistent cases that have not responded to a genuine trial of rehabilitation. Corticosteroid injection into the tendon is generally avoided: it relieves pain in the short term but results deteriorate over the following months compared with loading, and it carries a risk of tendon rupture.4

Seeking Advice

Your Family Doctor (GP)

Your Family Doctor will be able to diagnose and help treat your problem. He or she will be able to

  • tell you about your problem
  • advise you of the best treatment methods
  • prescribe you medications
  • and if necessary, refer you to Specialists (Consultants) for further treatment

Prevention

There are a few simple steps you can take to prevent yourself from getting patellar tendinitis.

  • If you are having knee pain don’t play through it. This may just make it worse
  • Use proper technique when playing sport
  • Stretch before exercise
  • Strengthen your leg muscles, in particular your quadriceps muscles

F.A.Q. | Frequently Asked Questions

Should I rest it completely?

No. Complete rest settles the pain but leaves the tendon weaker, and the pain usually returns when you go back to sport. Reducing the activities that load the tendon hardest, while continuing a structured strengthening programme, gives a better long-term result.1,2

How long does it take to get better?

Usually months rather than weeks, and longer if it has been present for a while. This is the part people find hardest, but a loading programme abandoned after six weeks is the commonest reason treatment fails.

Is it normal for it to hurt while I’m doing the exercises?

Yes, within limits. Discomfort during and shortly after loading is expected. It should settle within 24 hours and should not be getting worse from week to week. If it is, the load needs adjusting rather than stopping altogether.2

Can I keep playing?

Often yes, at a reduced volume, provided the pain is stable rather than escalating and you are doing the rehabilitation alongside it. This is worth planning with a physiotherapist rather than deciding week by week.2

Would an injection help?

Corticosteroid injection into the tendon itself is generally avoided. It can give quick relief, but in a trial comparing it with two loading programmes the injected group had deteriorated by six months while the exercise groups had maintained their improvement.4 It also carries a risk of weakening the tendon. Other injections are sometimes used in stubborn cases, but none is a substitute for the loading programme.

Why is it called tendinitis if there is no inflammation?

The name has stuck. What is happening in most long-standing cases is degeneration and disorganisation of the tendon fibres rather than inflammation, which is why the condition is increasingly called patellar tendinopathy, and why anti-inflammatory treatment on its own does not resolve it.1

Does it help to warm up first?

Yes. The characteristic pattern is pain that eases as the tendon warms up, so a proper warm-up before training makes the session more comfortable. It does not treat the underlying problem, and feeling better once warm is not a reason to increase the load.

References

  1. Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British Journal of Sports Medicine. 2009;43(6):409–416.
  2. Malliaras P, Cook J, Purdam C, Rio E. Patellar tendinopathy: clinical diagnosis, load management, and advice for challenging case presentations. Journal of Orthopaedic & Sports Physical Therapy. 2015;45(11):887–898.
  3. Rio E, Kidgell D, Purdam C, Gaida J, Moseley GL, Pearce AJ, Cook J. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. British Journal of Sports Medicine. 2015;49(19):1277–1283.
  4. Kongsgaard M, Kovanen V, Aagaard P, Doessing S, Hansen P, Laursen AH, Kaldau NC, Kjaer M, Magnusson SP. Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. Scandinavian Journal of Medicine & Science in Sports. 2009;19(6):790–802.
  5. Breda SJ, Oei EHG, Zwerver J, Visser E, Waarsing E, Krestin GP, de Vos RJ. Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial. British Journal of Sports Medicine. 2021;55(9):501–509.