Knee Problems: Overuse Injuries
Overuse Injuries are caused by chronic, repetitive microtrauma usually related to sport, causing damage to local tissues and resulting in onset of discomfort and pain.
Patella Tendinosis (Jumper's knee)
Overuse tendinopathies are common. Painful overuse tendon conditions
have a non-inflammatory pathology and therefore tendinitis is
not a correct term. Numerous investigators worldwide have shown
that the pathology underlying these conditions is tendinosis
or collagen degeneration.
The term tendinosis was first used in this context by Puddu et al. implying tendon degeneration without clinical or histological signs of intratendinous inflammation. The finding that the pathological bases of overuse tendon conditions in athletes are due to tendinosis is not new. In 1986, Perugia et al. noted the ‘remarkable discrepancy between the terminology generally adopted for these conditions (which are obviously inflammatory since the ending ‘-itis’ is used) and their histopathological substratum, which is largely degenerative’.
Patellar Tendinopathy in a Nutshell*
The clinical implications of patellar tendon research can be summarized as follows:
- We should adopt the term "patellar tendinopathy" or tendinosis rather than the misnomer tendinitis when referring to patellar tendon overuse injury. The key pathology is tendinosis - collagen degeneration and its sequelae.
A patient who presents with patellar tendinopathy for the first time may require 2 to 3 months to recover. A patient who has a long-standing injury may require 4 to 6 months to return to competition pain free and without recurrence.
Imaging has not been shown to be a useful guide to the choice of management or prognosis. A focal hypoechoic region on ultrasound or a region of high signal on MRI is certainly no indication, per se, for surgery.
Relative tendon unloading is critical for treatment success. This can be achieved by activity modification and by biomechanical correction. Biomechanical abnormalities may be anatomic (static and dynamic) or functional (from regional dysfunction).
Progressive strengthening graduating to eccentric exercises are the treatment of choice. To prescribe exercise effectively requires thorough assessment of the patient's functional capacity and a skilful approach to gradually increasing the demand that the athlete imposes on the tendon.
MRI of proximal patella tendinosis
Surgery has been considered the treatment of last resort for tendinopathies, and this certainly applies, if not more so, for a confirmed case of tendinosis. Surgery can be used to excise tissue affected by tendinosis, but surgery has not been proven to stimulate collagen synthesis or maturation. Thus, the tendon that has had surgery requires time for repair and strengthening. Reviews suggest that surgery in tendinosis has a 75% to 85% success rate, and for some tendons this figure may well be a very-best-case estimate. Therefore, an important implication of tendinopathy's underlying pathology being tendinosis is that conservative management must progress slowly. If the initial prognosis the patient receives is realistic, it is less likely that the patient will attempt to return to sport prematurely, suffer re-injury, and thus, "fail" conservative management. Because surgical treatment of tendinosis is not without failure, and recovery takes a minimum of 4 to 6 months, this treatment should be reserved for failure of a high-quality program of conservative management.
- K M Khan, J L Cook, J E Taunton, F Bonar. Overuse Tendinosis, Not Tendinitis. Part 1: A New Paradigm for a Difficult Clinical Problem. The Physician and Sportsmedicine, May 2000. Please note that free access to this article is no longer available.
- J L Cook, K M Khan, N Maffulli, C Purdam. Overuse Tendinosis, Not Tendinitis. Part 2: Applying the New Approach to Patellar Tendinopathy*. The Physician and Sportsmedicine, June 2000. Please note that free access to this article is no longer available.
- K M Khan, J L Cook, P Kannus, N Maffulli, and S F Bonar. Time to abandon the "tendinitis" myth - painful, overuse tendon conditions have a non-inflammatory pathology. BMJ 16 March 2002.
- Rees J, et al.: Management of Tendinopathy. AJSM
PreView February 2, 2009.
Iliotibial Band Syndrome (ITBS)
Iliotibial band syndrome (ITBS) is the most common cause of lateral knee pain in runners, with an incidence as high as 12% of all running-related overuse injuries. ITBS is believed to result from recurrent friction of the iliotibial band (ITB) sliding over the lateral femoral epicondyle. The ITB is a dense fibrous band of tissue that originates from the anterior superior iliac spine region and extends down the lateral portion of the thigh to the knee. The ITB has insertions on the lateral tibial condyle (the Gerdy tubercle) and the distal portion of the femur. When the knee is extended, the ITB is anterior to the lateral femoral condyle. When the knee is flexed more than 30°, the ITB is posterior to the lateral femoral condyle. Runners with iliotibial band syndrome often demonstrate tenderness on palpation of the lateral femoral condyle approximately 2 cm above the joint line. Tenderness is frequently worse when the patient is in a standing position and the knee is flexed to 30 degrees. At this angle, the iliotibial band slides over the femoral condyle and is at maximal stress, thus reproducing the patient's symptoms Clinically, increased or noticeable tightness of the ITB also may be noted upon examination and performing the Ober's test (the patient lies down on the unaffected side down with the unaffected hip and knee at a 90-degree angle. If the iliotibial band is tight, the patient will have difficulty adducting the affected leg beyond the midline and may experience pain at the lateral knee). A modified Thomas test (which is also called the rectus femoris contraction test or Kendall test) can be performed to assess flexibility of the hip flexors, hamstrings, and the ITB. This test is commonly used to assess rectus femoris muscle flexibility about the knee joint, but the reliability of this test is questioned by several researchers (5).
In patients with iliotibial band syndrome, MRI is very useful diagnostically and shows a thickened iliotibial band over the lateral femoral epicondyle. MRI often detects a fluid collection deep to the iliotibial band in the same region (iliotibial bursa).
This overuse injury occurs with repetitive flexion and extension of the knee. Inflammation and irritation of the iliotibial band also may occur because of a lack of flexibility of the ITB, which can result in an increase in tension on the ITB during the stance phase of running. Other causes or factors that are believed to predispose an athlete to ITBS include excessive internal tibial rotation, genu varum, and increased pronation of the foot.
The main symptom of ITBS is sharp pain or burning on the lateral aspect of the knee. Runners often note that they start out running pain free but develop symptoms after a reproducible time or distance. Early on, symptoms subside shortly after a run, but return with the next run. If ITBS progresses, pain can persist even during walking, particularly when the patient ascends or descends stairs.
Low mileage, recreational runners usually improve with a simple regimen of anti-inflammatory medication and appropriate stretches. However, higher mileage, competitive runners typically require a more comprehensive treatment approach. Treating the condition can be a challenge because underlying myofascial restrictions can significantly contribute to the patient's pain and disability. After acute symptoms are alleviated with activity restriction and modalities, problematic trigger points can be managed with massage therapy or other treatments. A stepwise stretching and strengthening program can expedite patients' return to running. The keys to success for the more resistant cases are myofascial therapy after acute inflammation has been addressed and progression to weight-bearing strengthening exercises, with particular attention to the gluteus medius muscle, before return to running. Corticosteroid injections should be considered if visible swelling or pain with ambulation persists for more than three days after initiating treatment. A small number of patients will not respond to conservative treatment and may require surgical release of the iliotibial band.
- John M Martinez, et al. Iliotibial Band Syndrome. eMedicine, December 6, 2006.
- Stephen M Pribut: Iliotibial Band Syndrome. Dr Stephen M Pribut's Sports Pages.
- Owen Anderson and Walt Reynolds: Common knee injuries and runners knee. Sports Injury Bulletin.
- Razib Khaund and Sharon H Flyyn: Iliotibial Band Syndrome: A Common Source of Knee Pain (pdf download). Am Fam Physician, 15 April 2005;71:1545-50.
- Jason D. Peeler and Judy E. Anderson: Reliability limits of the modified Thomas test for assessing rectus femoris muscle flexibility about the knee joint. Journal of Athletic Training, Sept-Oct, 2008.
- M Fredericson, M Guillet, L DeBenedictis. Quick Solutions for Iliotibial Band Syndrome. The Physician and Sportsmedicine, February 2000. Please note that free access to this article is no longer available.
Page updated on: 29 January 2017
Site last updated on: 28 March 2014
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