Gluteal contracture syndrome is a clinical syndrome caused by degeneration and contracture of the gluteal muscle and its fascial fibers, resulting in a restricted function of the hip joint, with characteristic gait and signs. Since Valderrama’s report in 1970, many cases have been reported at home and abroad, but the etiology is not clear.
I. Etiology
1, injection factors: most scholars agree that the disease is related to repeated hip injections, and the local formation of hard masses after muscle injection is the manifestation of myofibrositis.
2. Susceptibility factors in children
Immune factors. A large number of children receive intramuscular injections, but only a minority of them develop the disease. It was found that children with gluteal muscle contracture have immune regulation disorder, with significantly low TS cells and relatively hyperactive TH cells; the immune response caused by the semi-antigen of the drug cannot be suspended in time after receiving benzyl alcohol injection in children, which easily causes immune damage. Indirect evidence of this is provided by the observation of elevated serum IgG and decreased C3 in the children. Human erythrocyte membrane has a receptor, which is a glycoprotein, and erythrocytes can recognize and capture immune complexes in the body through the adhesion of the receptor on their membrane. Ninety-five percent of the receptors in circulating blood are located on the red blood cell membrane, so the primary cells from which people remove immune complexes are red blood cells. The test showed that the erythrocyte receptor activity and the level of erythrocyte membrane immune complexes in children with gluteal contracture were significantly lower than normal, suggesting that the children’s erythrocytes are immunocompromised and cannot effectively adhere to and clear the immune complexes generated after drug injection in a timely manner. Conjugate sectioning revealed deposits of immune complexes in the walls of the small vessels of the contracted gluteal muscles. The immune complexes can cause damage to the vessel wall, causing intravascular coagulation resulting in a hypoxic state of the tissue, which in turn leads to myocyte damage, fibroblast activation and eventually gluteal muscle fibrosis.
Scarring
Genetic factors
Trauma, infection and other factors
Pathological changes
Intraoperatively, the red muscle fibers were replaced by grayish-white fibrous tissue, which was more obvious on the greater trochanter of the femur. The thickened fascia was contracted and penetrated into the gluteus maximus and gluteus medius muscle fibers, which became grayish-yellow and could be interspersed with normal muscle fibers, and less normal muscle fibers in severe cases. The outer upper part of the gluteus maximus muscle was seen to have a fibrous contracture band with inconsistent width, usually 2-7 cm, involving the whole layer of the gluteus maximus muscle, with a pale color and inelastic, tendon-like tissue.
Microscopic examination: most of the contracted gluteus muscles showed myocyte atrophy, mostly focal or peripheral to the muscle bundle, and the closer to the fibrosis site the more obvious the atrophy was. The myocyte transverse lines disappeared, the nuclei crinkled and dissolved, and some formed homogeneous structureless material. The inter-myocyte and inter-myofascicular fiber intervals are enlarged and form fiber bundles, within which many fibroblasts are visible. The number of intermyocardial vessels was reduced, the walls were thickened, the lumen was small and irregular, some were occluded, and neutrophil and lymphocyte infiltration was seen around the vessels.
Clinical typing
According to the different clinical appearance, they are classified as follows
①mass type: nodular hard masses can be found on the buttocks.
(2) Membranous type: gluteal muscle fascia is contracted in sheets.
(3) Banding type: gluteal fascia becomes fasciculated contracture.
According to the muscles involved, they can be classified as
①solely gluteus maximus contracture type.
(ii) simple gluteus medius contracture type.
③Compound contracture of gluteus maximus and gluteus medius (including contracture of gluteus minimus).
Clinical manifestations
The disease is often bilateral, unilateral is rare, and there are reports of more males than females. Hip joint dysfunction? Patients have limited internal rotation and retraction of the hip joint. When standing, the lower limbs are externally rotated and cannot come together completely. When walking, there is often an outward eight, swaying gait and a jumping state when walking fast. When sitting, the legs cannot come together, the hips are separated in frog position, and it is difficult to rest one thigh on the other thigh (cross-leg test). When squatting, the lighter person squats with both knees apart, then squats and then comes together (circle sign). In heavy cases, the hip joints can only squat in the abducted and externally rotated position, and when squatting, the knees cannot come together, and the heels do not touch the ground, in a frog-like manner. On physical examination, it can be found that there is skin depression in the upper part of the outer hip, and the depression is more obvious when the hip is inwardly retracted, and there is a sense of tightness in the hip, and the lower limb is in the abducted and externally rotated position, and the hip is restricted in internal retraction and internal rotation, and the hip flexion is restricted in the neutral position of the lower limb, and the affected hip must be abducted and externally rotated, so that the affected side of the hip can draw a semicircle outward before it can be fully flexed back into the original sagittal plane. Ober’s sign is positive. Children with bilateral asymmetric hip contracture may have pelvic tilt and secondary lumbar scoliosis. The anterior superior iliac spine is lower on the severe side than on the mild side, and the umbilical-ankle distance is longer on the severe side than on the mild side, while the distance from the greater trochanter to the ankle is equal on both sides.
V. Surgical treatment
Local anatomy: The gluteus maximus muscle fibers are oblique from the inner superior to the outer inferior, the upper half of its fibers extend into the iliotibial bundle, the lower superficial half also extends the iliotibial bundle, and the deeper fibers end at the thick line of the musculoskeletal gluteus muscle, whose proximal edge is connected to the iliotibial bundle. A gap parallel to the longitudinal axis of the femur exists in the posterior aspect of the greater trochanter, where the fibers of the superior gluteus maximus extend deep into the iliotibial bundle, and can be used as a marker for release. During surgery, the proximal border of the gluteus maximus and the iliotibial bundle can be revealed by incision, and the sciatic nerve is located deep under the medial fascia. It is safer and easier to perform gluteus maximus release on its superficial surface.
Surgical incision: Nowadays, the surgery is mostly performed along the posterior superior curved incision of the greater trochanter, which clearly shows the location of the main contracture site and ensures smooth operation; moreover, the release at this site is mainly for tendon contracture, which is less traumatic and less bleeding; it is safer to perform the release on the superficial side of the interstitial space above the femur and can avoid damaging the sciatic nerve; the incision can also be appropriately extended downward. In the early days, small incisions, incisions along the iliac spine, and straight incisions were used, but they were rarely used because of unsatisfactory exposure and difficulties in complete release, and S-shaped incisions were rarely used because of excessive trauma, bleeding, and lack of aesthetics. Nowadays, arthroscopic release of gluteus contracture has become a popular trend, with a small incision of only 1 cm.
Surgical approaches (which can be briefly divided into the following categories)
(1) Excision of gluteus maximus contracture band: this surgery is traumatic, bleeding, easy to damage the sciatic nerve, residual cavity after surgery, and incomplete release, especially in heavy cases, where the gluteus maximus contracture band is large, and the medial contracture band is not completely excised due to the fear of damaging the sciatic nerve, which affects the efficacy. Therefore, it is now rarely used.
②Cutting off the contracture band of gluteus maximus: the operation is simple and less traumatic. For heavy cases, the effect is often unsatisfactory because the tense part of the gluteus maximus tendon plate is not released. Arthroscopic surgery is now feasible.
(3) Gluteus contracture band excision plus gluteus maximus stop release: using a curved incision above the posterior ramus, the posterior edge of the broad fascia, the lower edge of the gluteus contracture band and the lower part of the gluteus maximus tendon plate can be exposed, the surgical incision is small, the trauma is small, and the pathogenic factors can be fully resolved in the field, and the efficacy is satisfactory.
Postoperative complications
①Local hematoma formation: it is related to incomplete hemostasis and poor postoperative drainage. Local elevation and persistent pain after hematoma formation can easily lead to infection; hematoma compression can lead to ischemic necrosis of the skin at the incision margin. Therefore, intraoperative hemostasis should be complete, rotational drainage and local pressure dressing should be applied after surgery; necessary hemostatic drugs should be used after surgery. Early treatment of hematoma formation is found.
②Infection: associated with poor handling of aseptic principles and postoperative hematoma formation.
③ Incomplete relief or recurrence of symptoms: Incomplete relief of symptoms is related to incomplete release or soft tissue tension. Recurrence can be related to the contracture tissue not being completely cut off and becoming relatively shorter with development, or not performing functional exercise in time after surgery and scar re-adhesion.
(4) Incisional scars: Although the skin margin is well aligned during surgery, most children have large scars at the postoperative incision. This is considered to be related to their scarring quality. Therefore, it is believed that scarring should be considered as a manifestation of gluteal muscle contracture syndrome.
⑤ gluteus medius weakness: postoperative swaying gait can occur in those with a large portion of the gluteus medius severed, and the gluteus medius weakness will eventually disappear as the scar tissue connects the severed ends of the gluteus medius over time postoperatively.
Postoperative functional exercise: contracture release can recur after surgery due to re-adhesion of the gluteus medius muscle, so it is important to use active exercise and functional exercise after surgery to overcome the popping sign and frog leg sign, lengthen the remaining contracture tissue, improve the limb inequality barrier, prevent re-adhesion of the severed end of the iliotibial bundle of the superficial broad fascia tensor, and consolidate the release effect.
Steps.
Good limb position 6 hours after surgery: depillowed and lying flat, wrapping both knees together with bandages, soft pillow under the knee, flexing the hip 60° and flexing the knee 30°, fixed for 24 hours. Observe the wound bleeding, and remove the drainage when there is not much bleeding or drainage, and start functional exercise. Within 24-48 hours after surgery, assist and guide the patient to do cross-motion of both lower extremities in bed, flex the hip joints and practice sitting up and down, 3 times/day, 30 minutes/time. Forty-eight hours after surgery, assist the patient to get out of bed and walk in a straight line: chest up, head up, shoulders level, and both lower limbs crossed in a straight line. 3 times/day, 30 minutes/time. On postoperative day 3 to 4, gradually add tight hip abduction and knee squat exercises on the basis of one-step walking: feet together, hands flat, heels not off the ground, waist and back straight. 3 times/day, 200 repetitions. On the 7th postoperative day, on the basis of correcting abnormal gait, leg exercises (crossed legs) were performed, sitting on a reclining chair with the back close to the backrest, one leg over the knee, crossed over the other leg, left and right legs crossed, and left and right hip swinging active extension exercises. 3 times/day, 30 minutes/time. The above functional exercises should be performed gradually to prevent the wound from bleeding and incision from excessive activities.
On the basis of consolidation of the above functional exercises, after discharge from the hospital, functional exercises for the knee joint were performed by.
Sitting position, bend both hips and knees, then separate both hips outward to the maximum, and bring both feet together in front of the body, press the knee joint medially with both hands, bring both legs together as far as possible, and restore. Repeat 5 times.
② lying down, one side of the affected limb hip and knee flexion, tilt inward to the maximum position, and then tilt outward to the maximum position, restore. Repeat left and right alternately for 5 times.
③Standing position, separate the feet front and back, flex the knee in front, straighten the knee behind, press the hands on the front knee, slowly lean the body forward, maintain for 5 seconds. Return. Repeat 5 times alternately left and right, and insist on doing it for 6 to 2 months after discharge, and take squatting and sitting up freely as the standard of self-care.