Do you feel pain on the inside of the knee? Could you be experiencing Pes Anserine Bursitis?
What is it?
Pes Anserine Bursitis is a painful irritation of the pes anserine bursa of the medial (inside) knee. The pes anserine bursa is usually sandwiched between the conjoined tendons of the hamstring muscle and the tibia. The pes anserine bursa functions as a friction reducer between the SGT tendons (Sartorius, Gracillis, and Semitendinosis) and the tibia.
Trauma, degeneration, or overuse may trigger the synovial lining of the bursa to produce excessive fluid, resulting in a painful inflammation. Repetitive valgus or rotational stressors to the knee are the main cause of this issue.
Bursae throughout the body communicate therefore if the pes anserine bursa is irritated then there may be diffused swelling in other bursae.
Risk factors for the development of pes anserine bursitis include obesity, knee osteoarthritis, diabetes, and female gender. Pes anserine bursitis is present in up to one third of diabetics with symptoms in their knees. The increased incidence in women is thought to result from anatomically wider pelvis and increased Q-angles, which amplifies the valgus stress. Up to 75% of patients with knee osteoarthritis may suffer from pes anserine bursitis.
The prevalence of pes anserine bursitis is higher among distance runners, breaststroke swimmers, and athletes participating in sports that require cutting or rapid side-to-side movement which include sports like football, baseball, or soccer.
Some functional risk factors for the development of pes anserine bursitis include hamstring tightness, lack of knee extension, and improper or rapid changes in training.
This condition often coexists with other knee disorders such as osgood-schlatter disease, plica irritation, meniscus injury, and degeneration. Biomechanical deficits including pes planus or valgus knee deformity appears to increase one’s risk of the disorder.
The disorder should be considered in any patient with pain inferior to the medial joint line of the knee. The classic clinical finding of pes anserine bursitis is mild to moderate pain over the medial tibia near the insertion of the conjoint tendons. Pain often intensifies when ascending or descending stairs or when arising from a seated position. The pain may be provoked by activities that require side-to-side movement but is generally not aggravated by walking on level surfaces.
Local swelling may be possible in early stages of this condition.
Clinicians should assess hamstring flexibility because tightness in this muscle is associated with pes anserine bursitis. Hip abductor weakness and pes planus must be identified as functional deficits that increase valgus stress of the knee.
Plain films provide little value in the assessment of pes anserine bursitis but can help rule out any other bony pathologies like osteoarthritis. Ultrasonography may help identify bursal swelling. When necessary, MRI may be used to confirm the diagnosis and differentiate from current knee pathologies.
Treatment of pes anserine bursitis includes anti-inflammatory measures, activity modification, stretching, strengthening, and corrections of biomechanical deficits. Early onset symptoms may be eased with ice and NSAIDs.
Myofascial release and stretching may be utilized to help release adhesions and restore flexibility to the calf and hamstring muscles. Manipulation is appropriate to help restrictions in the lumbosacral spine and lower extremities.
Patients with fallen arches (pes planus) will benefit from arch supports or custom orthotics.
Patients with pes anserine bursitis will benefit from home-based stretching and strengthening exercises. Stretching exercises should focus on the hamstring, adductors, quadriceps, and calf muscles. Strengthening exercises should be directed toward the hip abductors to establish hip stability and control of femoral internal rotation.
Pes anserine bursitis, by itself, is generally considered a self-limiting condition but many of its pairing conditions are not so responsive.