Myocele

Myocele refers to a hernia formed when muscle tissue protrudes outward through a defect or weak area in the fascial sheath. It usually presents as a painless subcutaneous mass, is relatively rare clinically, and commonly occurs in the lower leg; most myocele masses are below 0.6cm, and sometimes they are multiple or bilateral. Its symptoms are mild and disappear after rest or at rest, so it is often ignored or missed.

Common Symptoms

Fatigue; Tu Youbao

Causes

(1) Etiology. Local myofascia of the lower limb becomes defective or weakened due to developmental abnormalities, surgical injury or trauma, and long-term chronic strain; this is the pathological basis of the disease, while increased local muscle pressure in the lower limb is the precipitating factor. (2) Pathogenesis. 1. Fascial defect or weakness. The common causes of fascial defect or weakness are as follows: (1) Under normal conditions, muscle fascia has normal physiological defects or weak areas; when muscle pressure increases, the muscle herniates through them. For example, the superficial peroneal nerve arises from the common peroneal nerve on the outer side of the fibular neck and descends between the peroneus longus and brevis muscles; its terminal branch pierces the fascia at the junction of the middle and lower 1/3 of the lower leg to become a cutaneous branch, causing a local defect or weakness through which lower-leg myocele can herniate. Muscle herniating through the fascial nerve exit can cause nerve injury and entrapment, in turn leading to a series of symptoms. (2) Surgical injury or sharp cutting can cause muscle injury and fascial rupture; for example, if only the skin is sutured during debridement and suture, when the muscle swells and pressure rises, it can bulge outward through the fascia. Likewise, blunt injury or fracture can damage the muscle and puncture the fascia; as the muscle swells and pressure rises, it bulges outward through the fascia to form a myocele. (3) Strenuous exercise or heavy physical labor, uncoordinated movement or excessive load, incorrect landing posture, and unstable lower-limb weight-bearing can cause extreme contraction of the lower-limb muscles, damaging the muscle structure; at this time the muscle belly markedly shortens and the epimysium tears longitudinally, forming a gap through which the muscle bulges; the herniated tissue may become incarcerated with a small amount of oozing, secondarily causing traumatic inflammatory reactions such as edema and exudation, as well as spasm of surrounding muscle groups. (4) Long-term chronic injury weakens or ruptures the lower-limb fascia. (5) Primary fascial disease causes weakness of the fascia at a certain site. 2. Increased muscle pressure. (1) After strenuous exercise or overactivity of the muscle, local metabolism increases, blood oxygen concentration decreases, and metabolic products accumulate, increasing microcirculatory exudation and interstitial fluid; the muscle can swell and hypertrophy; however, the fascial wall restricts expansion of the hypertrophied muscle, raising the pressure in the muscle compartment and in turn prompting the muscle to protrude through weak or defective areas to form a myocele. (2) Trauma, surgery, or the muscle's own disease can cause muscle swelling and increased pressure, bulging outward through the weak area of the surgical or injured fascia to form a myocele. In recent years, some have regarded myocele as a compensatory manifestation of chronic myofascial compartment syndrome; Zhang Yongfu and others also found that nearly half of patients with chronic lower-leg myofascial compartment syndrome have a myocele.

Treatment

Surgical treatment

Prevention

Local myofascia of the lower limb becomes defective or weakened due to developmental abnormalities, surgical injury or trauma, and long-term chronic strain; this is the pathological basis of the disease, while increased local muscle pressure in the lower limb is the precipitating factor. The main prevention is to ensure surgical asepsis and disinfection, prevent surgical accidents, rest and avoid overexertion, actively prevent chronic strain, and abstain from bad habits such as smoking and alcohol.

Recommended Department

It is recommended to visit the orthopedic surgery department; before the visit you may first book an appointment and connect with experts through this platform.

Warm reminder: The above information is provided for health education reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek care at a regular hospital in time.