Biceps Femoris is one of the three hamstring muscles forming the posterior portion of the thigh. A condition where a tendon gets completely pulled away from the bone is termed as an avulsion.
The term avulsion fracture is given to a condition where a fragment of a bone also gets pulled away along with the tendon.
About Biceps Femoris Tendon
Biceps Femoris muscle is a combination of two individual muscles which originate from different regions of the body. These two individual muscles are called the long head and the short head. The long head originates from an area which is posterior to the hip bone called the ischial tuberosity. The short head originates from the back of the thigh bone. Both these muscle bellies join together, pass through the knee joint, and insert into the superior external surface of the two shin bones i.e., the tibia and the fibula. It performs dual function of bending the knee and extending the hip.
Biceps Femoris Tendon Avulsion
Biceps Femoris muscle usually gets injured when there is vigorous bending of the knee like in sports such as sprinting. One of the main reasons for hamstring strain or rupture is if the sportsman is not adequately warmed up or is tired.
As stated above, biceps femoris tendon avulsion is the term given to a condition where the tendon completely pulls away from its bone. The most common site where this can take place at the attachment of the long head and the ischial tuberosity. The biceps femoris is more prone to injuries when a comparison is made with the other hamstring tendons. The reason for it is felt to be the innervation of the two heads by different branches of the sciatic nerves. When there is fatigue or improper warm-up of the muscle, firing of the nerves takes place in an uncoordinated fashion causing the muscle to contract in an inappropriate way resulting in an injury.
Avulsion fracture may also occur along with biceps femoris tendon avulsion. The term avulsion fracture is given to a condition in which a fragment of a bone also gets pulled away along with the tendon.
Symptoms of Biceps Femoris Tendon Avulsion
- Onset of immediate pain after a forceful motion.
- Excruciating pain due to avulsions normally occurring during forceful movement involving flexion of the hip and extension of the knee.
- The affected area swells up.
- There may be bruising noticed.
- Hamstring weakness i.e., decreased ability for resisted flexion of the joint of the knee.
- The detached bone fragment is able to be felt through the skin in the case of an avulsion fracture.
Treatment of Biceps Femoris Tendon Avulsion
- Rest, Ice, Compression, Elevation technique should be used at once.
- Compression using elasticized bandage should be used for support.
- A sports injury physician consultation is imperative.
- Strengthening and proprioception exercises are beneficial.
- Deep tissue massage is beneficial to improve the elasticity of the muscle.
- Ultrasound and TENS unit is helpful.
- An X-ray is used for confirmatory diagnosis of an avulsion fracture.
- For severe injuries or an avulsion fracture, surgery may become a necessity in order to reattach the tendon and the bone fragment.
- Comprehensive rehabilitation program should be started.
- Post surgery, the knee should be kept at a right angle using a knee brace for a few weeks.
- Recovery time post surgery is a bit prolonged.