Biceps Tendon Rupture of the Lower Limb

What is Biceps Tendon Rupture of the Lower Limb?

The biceps femoris muscle is one of the three muscles at the back of your thigh, joining two other muscles (the semimembranosus and semitendinosus muscles) to form what you know as the hamstring complex. It’s the strongest of these three muscles and plays a big role in bending and rotating your knee, and also in keeping your knee stable when it moves in certain ways.

This muscle essentially has two parts: a long head and a short head. In some people, the short part may naturally be absent. The long part begins from areas on your buttock bone and a nearby ligament, while the short part arises from areas on your thighbone and a separating tissue in your thigh. The two parts come together to form a tendon on your calf bone, ankle, and top part of your shinbone.

Interestingly, these two parts of the biceps femoris muscle are controlled by different branches of the same nerve – the sciatic nerve. This unique nerve supply might make the muscle more likely to get injured during sports activities.

If this muscle gets injured, it can greatly reduce your knee’s bending strength and stability. For instance, research has found that the bending force can reduce by 75% if the tendon of this muscle is transferred to a ligament on your fibula (a bone in your lower leg). This transfer is done to resist instability in your knee that often occurs due to an injury to your knee’s ligament and its outer covering. On the other hand, another study showed that this muscle was more active in people with damaged knee ligaments and its activity increased with certain exercises done to strengthen the thigh muscles.

If the tendon of this muscle tears, it can be treated either non-surgically or surgically, depending on how severely it has pulled away. Generally, patients recover well, and can return to high-leveled sports activities if diagnosed and treated effectively and in time. However, recurrence is fairly common.

What Causes Biceps Tendon Rupture of the Lower Limb?

The biceps femoris is a muscle in the back of your thigh that can sometimes get injured, most often in athletes who suddenly straighten their knee while bending their hip – a movement typical in running. The injury is most commonly seen in soccer players, but it can also happen in other sports like hockey, jogging, and water skiing.

There are several risk factors that can increase the chances of a biceps femoris tendon injury:

• If you’ve had a previous injury to the biceps femoris tendon, your chances of a new injury are six times higher. This is mainly because the healed injury leaves a weak scar tissue which increases the chances of re-injury.
• Rushing into training without adequate warm-up.
• If your hamstrings (the muscles at the back of your thighs) are weak compared to your quadriceps (the muscles at the front), specifically if the strength ratio is less than 0.6.
• If there is a big difference in hamstring strength between your two legs, especially if it’s greater than 15%.
• If your hip isn’t as flexible in extending backwards.
• If one of your legs is shorter than the other causing the muscles in the back of your thigh to be tighter.

Risk Factors and Frequency for Biceps Tendon Rupture of the Lower Limb

The biceps femoris is a muscle in the back of the thigh, and it’s rare for the tendon connecting this muscle to the bone of the pelvis, called the ischial tuberosity, to tear or get pulled away (avulsion). This type of injury tends to happen to young individuals who are still growing and is frequently seen in water skiers.

In adults, a more common injury is a tear at the point where the muscle and tendon connect, known as the myotendinous junction. This is typically the most damaged part of the hamstring complex, which is a group of muscles and tendons at the back of the thigh. The reason for this is that it’s responsible for flexing the leg and helps stabilize the knee. Injuries often happen while sprinting or playing sports that involve quick starts, usually during the sudden take-off phase of running.

Signs and Symptoms of Biceps Tendon Rupture of the Lower Limb

People who have injured their biceps femoris tendon, a tendon in the back of the thigh, may feel sharp pain in the back of the knee and the thigh, especially when they straighten the affected knee. They might also report hearing a popping sound in the knee during this movement. Certain activities such as soccer, running, or water skiing are common causes of this injury. In severe cases, the patient might walk with a stiff-legged gait to avoid bending their hip and knee due to pain.

A doctor examining such a patient might be able to feel a gap at the site where the tendon has ruptured, or even a lumpy area of bleeding under the skin. The patient may also feel pain on the outside of the injured knee or around the bony lump you can feel if you run your hand up the back side of your thigh to where it meets your buttock (ischial tuberosity). In some severe cases, patient’s knee flexing force might decrease and even experience foot drop due to weakness in the peroneal nerve. The doctor will assess the strength and movement of the affected leg and compare it with the non-affected one.

There are also specific tests that can cause pain in the affected areas and help to confirm the injury:

• Puranen-Orava Test: The patient places the heel of the affected side on a raised surface, to bring their hip to 90 degrees flexed, and then they try to touch their toes with the knee fully extended.
• Bent-knee stretch test: When lying on their back (supine position), with their hip and knee as flexed as possible, the doctor slowly straightens the patient’s knee.
• Modified bent-knee stretch test: It’s the same as the previous test, but in this scenario, the knee is extended quickly.

These tests are regarded as positive if the patient experiences pain at the back of thigh or knee during the test.

Testing for Biceps Tendon Rupture of the Lower Limb

Imaging techniques can be used to figure out how serious a biceps femoris tendon injury is and to what extent it affects the body.

X-rays, specifically an anteroposterior view of the pelvis and anteroposterior and side views of the femur, could reveal a bone fragment that has been pulled away from the ischial tuberosity (the curved bone at the base of the spine on the pelvis). This would be a sign of an injury.

Magnetic Resonance Imaging (MRI), can help quickly diagnose the injury because tendon injuries can vary a lot. An MRI can be used to evaluate how much the tendon has pulled back and check the condition of the bone structure around it. You might find a higher than normal signal intensity in T2 weighted images if there are partial tendon tears. Conversely, increased signal intensity in T1 weighted images is typically seen in cases of tendinopathy (a disease of the tendon).

Ultrasounds has the advantage that it doesn’t use radiation and is reasonably priced. Plus, an ultrasound allows a real-time evaluation, which can be used to observe the movement of the biceps femoris tendon compared to the soft tissues around it. A color or power Doppler ultrasound can also be employed to check for unusual blood vessel formation or inflammation in the injured tendon. Comparing the results to the healthy side may be useful for diagnosis.

Treatment Options for Biceps Tendon Rupture of the Lower Limb

When dealing with a biceps femoris tendon injury – that’s one of the tendons in the back of your thigh – there are both non-surgical and surgical ways to treat it.

Non-surgical approaches may include rest, applying ice to the area, taking anti-inflammatory medicine, gentle stretching, and therapeutic exercises over a 4 to 6 week period. This type of treatment is typically used for minor injuries like isolated ruptures of the biceps femoris tendon or ruptures at the connection between muscle and tendon. Research has found that athletes, including professional football players, are often able to resume high-intensity sports about six weeks after the injury. Over time, the ruptured tendon slowly heals, and the knee regains its strength. Adding in exercises to strengthen and stretch your stomach, hip, and quadriceps muscles may help to prevent further injury. One goal of these exercises is to balance the strength in your hamstring and quadriceps muscles.

An initial treatment within 48 hours of the injury may involve a special injection, guided by ultrasound, of what is known as Platelet Rich Plasma (PRP). Platelets are part of your blood and they can help with healing.

If the injury is more severe, or symptoms persist despite non-surgical treatment, surgery may be needed. Surgical repair usually allows about 80% recovery back to the pre-injury level, and generally allows a return to sports about six months after the surgery. Surgery may be considered in these cases:

• The tendon has torn off the bone at the top.
• Persistent symptoms after six months of non-surgical treatment.
• If another hamstring tendon is also torn, especially with young patients who are still quite active.

One surgical technique is open reduction and internal fixation. This is recommended for cases where a piece of bone has been pulled away by the injury and is out of place by more than 2 cm, or if the bone fragments continue causing symptoms. The surgery generally involves repositioning the bone fragments and fixing them in place with screws or washers. Special sutures or stitches may also be used to secure the tendon back to the bone. The rate of success for this procedure is good.

Another surgical approach is to repair the biceps tendon, usually done with the patient lying on their stomach. The surgeon makes a horizontal incision over the buttock crease and careful measures are taken to avoid injuring the sciatic nerve. The tendon is then reattached to the ischial tuberosity, a bony part of your pelvis, using special stitches. In some cases, a tissue graft may be needed.

Most people recover well after either non-surgical treatment or a timely surgical repair. However, there is still considerable debate regarding the exact circumstances under which surgery should be the preferred method of treatment. Some individual case studies suggest that a complete rupture of the biceps femoris tendon should be treated surgically.

What else can Biceps Tendon Rupture of the Lower Limb be?

When a doctor is trying to understand the cause of back thigh pain, there are several conditions they might consider to pinpoint the exact cause. These include:

• Diseases that affect the ‘sitting’ bone, or Ischial tuberosity
• Damage to the area where the hamstring muscle connects to the bone, also known as Hamstring enthesopathy
• Pain that feels like it’s in the back of the thigh, but is actually coming from areas like sacroiliac joints (the joints in your lower back), your lumbar spine, your pubic bones, or your gluteal muscles
• Sciatica (a condition that causes pain down the back of the leg)
• Stress fractures or small cracks in the pelvis or the neck of the fibula bone

It’s important to remember that not all pain in the back of the thigh is caused by injury to the biceps femoris tendon— one of the large tendons located at the back of the thigh. In addition to this, when an injury does occur in this tendon, it often affects the whole set of hamstring muscles.

What to expect with Biceps Tendon Rupture of the Lower Limb

The outlook for an injury to the biceps femoris tendon, a major muscle in the leg, is generally positive if it is quickly and properly diagnosed and treated. Many athletes can return to their professional sports activities after receiving treatment.

Possible Complications When Diagnosed with Biceps Tendon Rupture of the Lower Limb

: Rupturing the proximal biceps femoris tendon is quite rare, but if it isn’t treated correctly, the patient may experience weakness, pain, and a condition called sciatic neuralgia. Surgical treatment of these injuries can be quite complicated, especially if they are chronic rather than acute (happening more than six weeks ago).

Here are some of the complications that have been reported:

• Recurrence: This is the most common complication. It’s more likely to happen if the patient’s hamstring is weak, there’s an imbalance in strength between the hamstring and quadriceps muscles, or the patient goes back to their regular activities too soon.
• Peroneal nerve injury: This usually happens with more distal injuries and tends to resolve on its own over time.
• Sciatic nerve injury: This tends to occur in chronic cases where the nerve has become scarred. It’s a sign that the nerve needs to be examined more closely.
• Hamstring syndrome: This can complicate cases where avulsion injuries are being managed without surgery. The patient will experience pain in specific spots, like the back of the buttock and the ischial tuberosity (part of the hip bone). It’s usually treated with surgery and in some instances, may lead to injury of the sciatic nerve.
• Nonunion of the ischial tuberosity: This can occur when displaced bony avulsion fractures of over 2 cm are managed without surgery. The usual treatment is surgical repositioning and fixation, occasionally with a bone graft.

Recovery from Biceps Tendon Rupture of the Lower Limb

After surgery, doctors usually advise patients to only put some weight on their leg for about 4 to 6 weeks. This is done while keeping the knee bent at a 40-degree angle. This approach is crucial to ensure the protection and healing of the repaired area.

Preventing Biceps Tendon Rupture of the Lower Limb

As more people take part in high-intensity workouts, it’s important that everyone, especially athletes and younger, active individuals, understand how to avoid injuries. Your doctor, nurse, or other healthcare professional should provide advice about safe workout routines. For instance, a popular exercise called the “Nordic hamstring exercise” helps to protect your hamstrings, the muscles at the back of your thighs. During this exercise, someone needs to hold your heels to the ground while you slowly lean forward and then back. This can reduce the risk of a hamstring injury by up to 70%.

In addition, exercises that target specific muscles in your hamstrings are also beneficial. For example, hip extension exercises focus on the ‘long head of the biceps femoris’ and ‘semitendinosus’ – these are specific parts of your hamstring muscles located in your thighs and near your buttocks. Knee flexion exercises, on the other hand, primarily target ‘semitendinosus’ and the ‘short head of the biceps femoris’, which are also crucial parts of your hamstrings. By incorporating these exercises into your routine, you can help to prevent hamstring injuries and stay fit and healthy.