They found that the mean thickness of PA in knees with osteoarthritis was significantly greater than the controls and that higher PA thicknesses were associated with higher osteoarthritis scores on a visual analog scale (VAS). A Turkish study performed an ultrasonographic assessment of the PA tendon and bursa in patients with knee osteoarthritis (6). Some researchers have proposed that PA tendon pathology is much more likely in those who are older and with osteoarthritic co-morbidities. Mexican researchers evaluated 22 patients with PA bursitis and found valgus knee deformity, alone or in association with medial collateral instability, to be a risk factor for PA injury (5). Because gait patterns most significantly tax the medial knee, it is unsurprising that PA tendonitis and bursitis affect long-distance runners more than other athletes (4). Movements that can precipitate a PA injury are those involving valgus (eg as a result of excessive pronation in running gait ) or rotatory stresses at the knee (3).
The underlying factors increasing the risk of PA injury are often multifactorial, but typically involve high hamstring loading combined with sub-optimal biomechanics. Having said that, evidence suggests that a PA bursitis occurs more frequently and responds more quickly to treatment than tenosynovitis (2). Fortunately, the treatment is the same for both conditions. Clinically, it is difficult to distinguish these two pathologies. Pain as a result of PA pathology can arise as a result of 1) tenosynovitis of the PA tendon, 2) inflammation of the PA bursa, or 3) a combination of the above. Additionally, three types of insertion were noted (short, band-shaped, and fan-shaped). However, six distinct types of PA were distinguished based on the presence of accessory bands. The researchers found that in all cases, the PA consisted of the sartorius, gracilis, and semitendinosus tendons.
For example, a recent study examined PA structure in 102 cadaveric limbs (1). Representation of the medial aspect of the left knee.Īlthough not especially relevant in a clinical context, it’s worth appreciating that the structure of the PA differs among individuals. The pes anserinus aids knee stability by helping the medial ligament resist valgus forces. Under the conjoined tendons lies the pes anserine bursa, a sac which provides smooth movement of the conjoined hamstring tendons over the medial collateral ligament. Visually, these conjoined tendons form a structure reminiscent of a goose’s webbed foot and were named from the Latin roots, pes for foot and anserinus for goose. Each of these three muscles is innervated by a different nerve: the femoral, obturator and tibial nerves respectively. The pes anserinus (PA) – also known as pes anserine or the ‘goose’s foot’ – refers to a conjoined insertion of the sartorius, gracilis and semitendinosus muscles along the proximal medial aspect of the tibia ( see figure 1). Because these injuries are comparatively rare, missed diagnosis is common and can result in unnecessary knee surgery. However, in athletes with vigorous and repetitive hamstring use, there is another possibility – pes anserinus injury. When medial knee pain presents, there are several possible causes, including an injury to the medial ligament, medial cartilage/meniscus, or medial tibial stress fracture.
Knee injuries are prevalent in athletes due to the loads transmitted through the knee joint during sport. The time it takes to heal the condition varies, but results can be achieved in 6 to 8 weeks or less when a proper stretching and strengthening program is implemented.XVIII Pan American Games – Lima 2019 – Roller Speed Skating REUTERS/Susana Vera Physical therapy will help you return to your normal lifestyle and activities. Certain positions, motions, or disease processes can cause constant friction or stress on the bursa, leading to the development of bursitis. This pain usually leads to difficulty walking, sitting down, rising from a chair, or climbing stairs.
Pain may also be experienced when bending or straightening the knee. Pain and swelling are usually felt on the inner lower side of the knee. Bursitis occurs when the bursa has become irritated and inflamed, and this condition is usually painful. It lies beneath 3 tendons of the hamstring muscle, and it prevents the tendons from rubbing on the shinbone of the lower leg. Pes anserine bursitis is a painful knee condition that occurs most commonly in young people involved in sports, middle-aged women who are obese, and people aged 50-80 who have osteoarthritis of the knee.The pes anserine bursa is a small, fluid-filled sac located 2–3 inches below the inner side of the knee.