Hip dysplasia in children: diagnosis

Developmental hip dysplasia (DDH) is the most common congenital pathology of the musculoskeletal system. Pathology is detected in 5-16 cases per 1000 newborns. Therefore, after the birth of a child, it is very important not to ignore regular examinations by a pediatric orthopedist. In the first year of life, examinations should be carried out every 3 months to monitor the formation of joints. For diagnosis, a clinical examination, x-ray and ultrasound are used, which can be done in Minsk; we have a high level and extensive experience in the treatment of this pathology.

Degrees of hip dysplasia in children

The degree of pathology is determined by the relationship between the head of the femur and the acetabulum: preluxation, subluxation and dislocation. The norm is shown in picture (A).

• Pre-dislocation (B) – the joint capsule is stretched, the femoral head is easily dislocated/reduced during adduction/abduction. Typically, by 7-10 days after birth, this symptom disappears.
• Subluxation (C) - the head of the femur is displaced outward and upward; due to this displacement and increased pressure, the limbus can shift.
• Dislocation (D) – the head loses contact with the socket, moving beyond the limbus. It provokes volvulus and even fusion.

Clinical symptoms

• asymmetry of folds (often);
• increased mobility in the hip joint;
• abduction restrictions;
• shortening of one of the limbs (rare).

An ultrasound of the hip joint provides a more accurate picture. Compared to x-rays, which are difficult to perform with a newborn because the baby must be in an even position (successful only in 5-10% of cases), the ultrasound technique displays cartilage components that are not normally visible with the x-ray method.

What does it look like in the photo?

To determine pathology from X-ray images and ultrasound, various schemes and approaches are used.
To do this, it is necessary to set the angle of inclination of the roof (acetabular angle), in newborns it is on average 25-29. To do this, draw a vertical line through the middle of the sacrum. Then a horizontal line is drawn perpendicularly through the Y-shaped cartilages, through the lower points of the ilium (Hilgenreiner's line). Then a Perkin line is drawn perpendicular to the horizontal line through the outer upper edge.

When studying the displacement of the femoral head, 2 values ​​are used: “angle α” - the position of the acetabulum, characterizing the bony roof, and angle β, indicating the development of the cartilaginous roof. Author: Serdyuchenko Sergey Nikolaevich Orthopedic traumatologist of the highest category

Correction of pathological antetorsion and neck-shaft angle of the femur in the treatment of residual hip dysplasia

Key words: hip dysplasia, femoral osteotomy
Introduction. As is known, with clear organization of early detection of congenital hip dislocation (CDH) and the beginning of its treatment in the maternity hospital, the need for surgical treatment almost completely disappears. Unfortunately, from 0.11 to 26% of dislocations remain untreated by the second half of life, most often in children who can stand and walk, and 2-14% of patients are admitted for surgical treatment. Of these, only 50% are operated on due to the ineffectiveness of previously carried out conservative treatment, the rest - due to late recognition [1-3,8].

One of the reasons for insufficient centering of the femoral head in the socket, as is known, is deformation of the proximal femur, manifested in the form of an increase in the neck-shaft angle (CHA) and antetorsion angle. Most authors propose to eliminate it through various corrective osteotomies of the femur, which are performed both as independent operations and in combination with operations on the acetabular component of the joint [4-7,9,10].

Material and methods. Our data are based on the observation of 60 patients with VHF who underwent extra-articular surgical correction of the femoral component (corrective VDO) for residual subluxation of the femoral head. Our contingent consists of children with late diagnosed hip dislocation - 24 (40%) and 36 (60%) - as a result of unsuccessful previous treatment (Table 1).

Table 1

Distribution of patients depending on treatment received before admission

The average age of patients at the time of surgery was 5 years. There were 20 boys, 40 girls. Damage to the right joint was observed in 14 children, the left – in 31, and both joints – in 15 (Table 2).

table 2

Distribution of patients by gender, age and side of lesion

In our practice, to adapt the pathologically oriented proximal femur to the acetabulum, we performed intertrochanteric, shortening, detorsion-varrising osteotomy of the femur. If necessary, it was supplemented with medializing components. The angle of pathological antetorsion and the required degree of detorsion produced were determined using the Strzyzewski method using anteroposterior radiographs in the normal position and in the position of abduction and internal rotation of the hips [2]. The bone fragments of the femur were fixed with an L-shaped plate. Such surgical tactics of interventions allow one-step centering of the femoral head into the socket, reducing the load on the articular surfaces, which creates optimal biomechanical conditions for the development of elements of the hip joint (HJ) and reduces the risk of aseptic necrosis, and in some cases, in the presence of necrosis, its partial regression occurred ( wedge example).

Clinical example. We present the following observation: Patient I., I/B 10109/1071, dated December 11, 2007, was admitted to us at the age of 5.7 years. Diagnosis: bilateral congenital dislocation of the hips. Condition after conservative treatment. aseptic necrosis of the head of the right femur.

From the anamnesis - tight swaddling for 8 months, after the start of walking we went to the clinic, where after an x-ray at the age of 1 year. a diagnosis was made of congenital dislocation of the right hip, but no treatment was received (Fig. 1a). At the age of 1.9m. They went to the doctors with a complaint about their gait. An X-ray was taken, a diagnosis of bilateral congenital dislocation was made, and surgical treatment was proposed, which the patient’s parents refused (Fig. 1.b). After 7 months, we went to another clinic, where, after another X-ray confirmation of bilateral congenital dislocation, at the age of 2 years and 4 months, after 1 year and 2 months. After the diagnosis of bilateral VVB was established, conservative treatment according to Ter-Egiazarov was started (Fig. 1).

Rice. 1. Radiographs of the patient before the start of treatment:

A. 07/29/2003 – the pathology was first identified at the age of 1 year 2 months,

b. 02/20/2004 – surgical treatment was proposed at the age of 1 year 9 months,

V. 09/30/2004 – treatment started at the age of 2 years and 4 months.

As can be seen from a series of radiographs (Fig. 1), as the child grows and the dislocation is not eliminated, the degree of hip dysplasia increases. Radiologically, this is manifested in an increase in the bevel of the roof of the acetabulum, a decrease in its depth, an increase in coxa valga and anteversion of the proximal femur, as well as a continuing cranial displacement of the femoral head towards the wing of the ilium. As can be seen from the example, late diagnosis of VVB leads to aggravation of the initial condition of the hip joints. If at the age of 1 year. 2 m. the child had only a state of dislocation of the 3rd degree on the right, and 2 on the left according to Tönnies, then a year later by the time the treatment began, a high dislocation of both hips had formed (4th degree according to Tönnies). In this case, there was a disruption in the development of the pelvic and femoral components of the joint and further cranial displacement of the femoral head.

Rice. 2. Radiographs of the patient during treatment:

A. 02/03/2005 – control after 3m. after the start of treatment, on the right the head is at the level of the acetabulum, on the left – 3rd degree of dislocation according to Tönnies,

b. 03/03/2005 – control in an abductor splint of unknown design, the femoral heads are centered in the cavity,

V. 05/16/2005 – control in an abductor splint of unknown design, the femoral heads are centered in the socket, but a certain lateroposition is determined on the right,

June 24, 2005 – control in abduction splint of unknown design, femoral heads are centered in the socket, the roofs of the acetabulum are still sloping,

d. 07/10/2006 – control photograph after removal of the splints and completion of treatment, on the right is determined by the 2nd degree of dislocation according to Tönnies and the initial phenomena of aseptic necrosis.

According to the parents, over the next 1 year 8 months. the patient was treated with abducting plaster casts and splints until the age of 4 years. Treatment was carried out on an outpatient basis, without the use of physiotherapy procedures. The plaster casts were changed and examined by doctors, according to the parents, once a month. After control radiography on July 10, 2006. the abduction splint was removed and over the next 8 months the patient received rehabilitation treatment (Fig. 2).

We first came for a consultation on March 14, 2007. After radiography, surgical treatment was proposed, which the parents refused (Fig. 3).

Rice. 3. Radiographs of the patient dated March 14, 2007, which reveal the phenomenon of severe aseptic necrosis of the right femoral head

8 months after the consultation, on December 11, 2007, the patient was admitted for surgical treatment. In order to measure the neck-shaft angle and the angle of pathological antetorsion, the patient underwent radiography in the anteroposterior projection in the neutral position and in the position of abduction and internal rotation (Fig. 4).

Rice. 4. Radiographs of the patient dated November 13, 2007. in anteroposterior projection:

A . in neutral position. Black indicates the neck-shaft angles (angles b) before surgery (right – 127o and left – 145o). White indicates the acetabular angles (angles a) before surgery (right – 34o and left – 19o). The black dotted line indicates (angles in) the Wiberg angles (right – 5o and left – 11o).

b . in abduction and internal rotation. Black indicates the neck-shaft angles (angles b) before surgery (right – 115o and left – 131o).

In order to more fully identify the nature and extent of the spread of aseptic necrosis, identify the most congruent articular surfaces of contact between the femoral head and the acetabulum, as well as clarify the angle of pathological antetorsion, a CT scan with multiplanar reconstruction was performed (Fig. 5).

Rice. 5. CT scan with multiplanar reconstruction dated November 20, 2007.

As a result of a comprehensive study of the patient, the following characteristics were identified: acetabular index (right – 340 and left – 190), neck-shaft angles (right – 1270 and left – 1450), antetorsion (right – 500 and left – 540), angle Viberga (right - 00 and left - 110). In connection with this first stage (December 18, 2007), surgical correction of the pelvic and femoral components of the joint was performed - DVO of the right femur and Salter pelvic osteotomy on the right, with additional fixation with a plaster cast. After 3 months, the bandage was removed (Fig. 6), metal structures were removed after 6 months.

Rice. 6. Dynamic series of radiographs of the patient in the anteroposterior projection:

A . 04/30/2008 – control after 4m. after DVO of the right hip and pelvic osteotomy according to Salter on the right,

b. 05/24/2008 – control after 5m. before removing the spokes

Rice. 7. Radiographs of the patient dated September 23, 2008. in anteroposterior projection:

A. in neutral position

b. in abduction and internal rotation

In the process of preparing for surgery on the left hip joint, the following characteristics were identified: acetabular index (right – 17o and left – 19o), neck-shaft angles (right – 114o and left – 145o), antetorsion (right –25o and left – 53o), Wiberg angle (right – 31o and left – 11o).

10/18/2008 The second stage involved surgical correction of the femoral component – ​​the VAD of the left hip, with additional fixation with a plaster cast. Considering that after correction of the femoral component the acetabulum completely covered the femoral head and the satisfactory value of the acetabular index, pelvic osteotomy was not performed (Fig. 7). After 1.5 months, the bandage was removed (Fig. 8). The patient received intensive rehabilitation treatment and went swimming. The observation continued until the end of 2009, but was stopped due to moving to permanent residence abroad.

Rice. 8. Dynamic series of radiographs of the patient in the anteroposterior projection in a neutral position:

A. Radiographs of the patient dated December 15, 2008. – 2 months after the second operation.

b. Radiographs of the patient dated October 27, 2009. – in 1 year.8m. after surgery on the right hip joint and 1g. after surgery on the left hip joint

Rice. 9. Dynamic series of radiographs of the patient in the anteroposterior projection:

A. 11/13/2007 – in a neutral position at the time of arrival.

b. October 27, 2009 – in neutral position, after 1g.8m. after surgery on the right hip joint and 1g. after surgery on the left hip joint.

As can be seen from the clinical example, in a patient with bilateral dislocation of the hips on the right, grade 3, and on the left, grade 2 according to Tönnies, in the absence of treatment, the dislocation progressed over the course of a year on both sides to grade 4 according to Tönnies; after inadequate treatment, the condition was complicated by aseptic necrosis of the right femoral head .

Results and discussion. After osteotomy of the pelvis and femur, the congruence of the articular surfaces on the right increased significantly, and the pressure on the head of the right femur began to be distributed more evenly. As a result, the phenomena of aseptic necrosis not only did not progress, but partially regressed over time (Fig. 9). As can be seen on the radiographs, the heads of both femurs are centered in the acetabulum, and the anatomical relationships of the elements of the hip joint are restored. At the time of the last observation, after 1 year. 8m. after surgery on the right hip joint and 1g. after surgery on the left hip joint, the following radiological characteristics were revealed: acetabular index (right – 16o and left – 150o), neck-shaft angles (right – 115o and left – 114o, Wiberg’s angle (right – 29o and left – 27o) (Fig. 8b).

All patients after DVO showed changes in the neck-shaft angle within 5-10o over the next 5 years after surgery. This is due to the fact that in preschool children the likelihood of revalgization and its degree is much higher, which is most likely due to the active growth of the body during this period. Correction of the joint motion to 90°, as recommended by other authors [2,6], was not performed, since with pronounced overcorrection, in our opinion, a violation of the biomechanics of the joint occurs, which subsequently affects the development of an incorrect walking stereotype. Long-term results from 1 year to 5 years were studied in 44 (73.3%) patients. Good and satisfactory results were obtained in 38 (86.3%).

Conclusions. As a result of the analysis of our work, we came to the conclusion that the indications for corrective osteotomy of the femur are: patient age over 3-4 years, decentration of the femoral head (femoral head coverage ratio 0.6 or lower, Wiberg angle less than 15o), severe valgus deformity femoral neck (140o or more), pathological anteversion more than 40o. At the same time, in preschool children, hypercorrection of the neck-shaft angle (valgization) to 105-115o and correction of the anteversion angle to 10o-15o are biomechanically most justified.

As our observations show, the fear of many doctors and parents about surgical intervention and excessive reliance on self-development and additional development of articular elements in the process of growth can be detrimental to the health of patients. Despite the presence of a positive functional state in the patient, over time the body’s compensatory abilities are exhausted, and the patient’s functional state worsens, equal to the data of the radiation study. And it is this factor that often leads to the loss of the golden time of surgical intervention. As a result, in most cases, surgical treatment is carried out in patients who already have persistent and significant deformities of the hip joint, which sharply reduces the effectiveness and efficiency of surgical interventions, casts a shadow on the method itself and does not allow one to correctly assess its real significance.

Literature

1. Erofeev V.N. Early ultrasonographic diagnosis and treatment of hip dysplasia in children in the first months of life. Dis…. Ph.D. honey. Sci. Rostov-on-Don, 2004.
2. Kralina S.E. Treatment of congenital hip dislocation in children from 6 months to 3 years. Dis…. Ph.D. honey. Sci. M., 2002.
3. Chirkova N.G. Treatment of congenital dysplasia and hip dislocation in young children. Dis…. Ph.D. honey. Sci. Kurgan, 2006.
4. Sharpar V.D. Features of surgical treatment of congenital hip dislocation in children in different age groups. Pediatric surgery. 2005, No. 1., p. 8-15.
5. Salter R., Hansson G., Thompson G. Innominatae osteotomy in the management of residual congenital subluxation of the hip in young adults. Clin. orthop. 1984, Vol. 182, P.53-68.
6. Spence G., Hocking R., Wedge JH and Roposch A. Effect of innominate and femoral varus derotation osteotomy on acetabular development in developmental dysplasia of the hip. J. Bone Joint Surg. Am. 2009, Vol. 91, pp. 2622-2636.
7. Tonnis D. and Heinecke A. Current concepts review—acetabular and femoral anteversion. Relationship with osteoarthritis of the hip. J. Bone Joint Surg. Am. 1999, Vol. 81, pp. 1747-70.
8. Weinstein SL, Mubarak SJ and Wenger DR Developmental hip dysplasia and dislocation: Part I J. Bone Joint Surg. Am. 2003. Vol. 85, p.1824-1832.
9. Williamson DM, Glover SD, Benson MK D'a. Congenital dislocation of the hip presenting after the age of three years. J. Bone Joint Surg. Br. 1989, Vol. 7l, P.745-751.
10. Zadeh HG, Catterall A., Hashemi-Nejad A., Perry RE Test of stability as an aid to decide the need for osteotomy in association with open reduction in developmental dysplasia of the hip. A long-term review. J. Bone Joint Surg. Br. Vol. 82, p.17-27, 2000.

Dependence of angles on the age of the child

After birth, children regularly undergo preventive examinations by an orthopedist. An increase in the acetabular index with age increases the risk of pathology of the femoral head. However, at an early stage of improper formation of the musculoskeletal system, the disorder can be corrected without surgery in a short time.

Table of normal hip joint angles in children by month:

If the angle is 5 degrees greater than normal, a subluxation is diagnosed, if the angle is 10 degrees greater than the norm, a dislocation is diagnosed, and if the angle is more than 15 degrees, a high dislocation is diagnosed.

There are 3 types of coxarthrosis:

• Type I - dysplasia of the acetabulum is manifested by an increase in the entrance to the cavity, the head is subluxated;
• Type II - subluxation, or low dislocation. The head is displaced higher, there is a true cavity and neoarthrosis, between which the connection is maintained, so that together they form a figure similar to a figure eight. The head is in contact with the false cavity;
• Type III - high, or complete dislocation. There are true and false depressions delimited from each other. The head of the femur is in contact with the false socket.

The main treatment method for dysplastic coxarthrosis in adults is surgery . In this case, organ-preserving operations and hip replacement are used.

For many years, the main methods of surgical treatment of CD were corrective osteotomies (pelvic, femoral, combined), arthroplasty and arthrodesis. Of the organ-preserving operations previously most often used:

• triple pelvic osteotomy,
• intertrochanteric osteotomy of the femur,
• plastic roof of the acetabulum.

Triple osteotomy is performed while maintaining congruence of the femoral head and acetabulum and has a positive effect on the biomechanics of the hip joint by improving the coverage of the femoral head and reducing the resulting forces acting on it.

Intertrochanteric osteotomy changes the biomechanical conditions of the functioning of the hip joint, which is manifested in a change in the load axis, redistribution of the lengths of the arms of body weight and traction of the muscles surrounding the joint, a decrease and more uniform distribution of intra-articular pressure per unit area of ​​the cartilage surface, muscle decompression, and eliminates the vicious position of the limb.

The idea of ​​creating a bone canopy to provide support for the head of the femur and prevent its subluxation during THA was first proposed by F. Konig in 1891.

Subsequently, the operation was significantly improved. Nowadays, periacetabular osteotomy is more often used, sometimes in combination with osteotomy of the proximal femur.

Periacetabular osteotomy (PAO) was first described by Professor Reinhold Ganz about 30 years ago and has become the treatment of choice for symptomatic acetabular dysplasia in adult patients.

PAO allows for complete reorientation of the acetabulum to provide greater lateral and anterior coverage of the femoral head by the acetabulum, reduce hip subluxation and medialize the center of the hip joint, redistribute high contact stresses from the edge of the acetabulum to the entire articular surface, and transform dysplastic femoral shear stresses through the articular cartilage into compressive stresses, which are more favorable to the longevity of the cartilage.

Short-term results after PAO show that up to 71% of patients can achieve the same or higher level of physical activity after surgery. Novais et al demonstrated that at 2 years of follow-up, UCLA activity scores were on average higher and WOMAC pain scores lower than preoperatively.

In the RNIITO named after R.R. Vreden, 61 PAOs were performed in the period from 2000 to 2021. The average age of patients is 31 years (from 18 to 48 years), women - 52, men - 9. Outcome in total endoprosthetics in 6 patients (9.8%): 4 patients in the first 2 years, 1 patient after 5 years and one after 11 years. Among the complications, 2 cases of sciatic nerve neuropathy, 2 intra-articular osteotomies and 1 fracture of the posterior column of the pelvis were identified.

Reconstructive surgical interventions are effective only in the early stages of the disease and give positive results only within 5–10 years.

Surgical treatment of residual dysplasia after previous surgery in childhood may be more difficult than treatment of acetabular dysplasia without prior surgical treatment.

Hips that have had previous surgery may have scar tissue that alters the anatomy and complicates surgical technique, compromising both the patient's preoperative and postoperative function. Following pelvic osteotomy surgery in early childhood, there is evidence from gait analysis studies that patients experience hip muscle weakness, gait deviations, and increased peak axial forces within the joint itself.

The main and most effective method of treating dysplastic coxarthrosis is hip replacement. The determination of the tactics for hip replacement is influenced by various factors: the degree of dysplasia, the severity of arthrosis, the presence of a history of previous operations, etc.

Hip replacement in grades I–II according to Crowe is performed as during a “standard” surgical intervention. The acetabular component is implanted into the true (anatomical) acetabulum. Any available cemented or cementless fixation components can be used that match the shape of the femoral canal and provide reliable primary fixation. The most difficult task is endoprosthetics for dysplasia of III–IV degrees according to Crowe .

Surgical treatment of patients in this category requires high professionalism and sufficient experience from the surgeon. The acetabulum is rudimentary, the femur is in a position of high dislocation. The acetabular component must be placed in its true position, restoring the anatomical center of rotation.

Based on the analysis of CT data in patients with hip dysplasia, it was established that a cranial displacement of the acetabular component by more than 2.5 cm leads to protrusion of the femoral component into the pelvic cavity. Cranial displacement of the component is possible by no more than 2 cm, and the risk of early instability of the component is much higher than when installed in an anatomical position. Various methods are used to install endoprosthetic components in cases of severe dysplasia (Bicanic G. et al. Modern concept of dysplastic hip arthroplasty.

Acetabular reconstruction methods:

• standard metal augments,
• custom acetabular augments (3D printing),
• roof reconstruction using vascularized bone,
• roof reconstruction with transplanted iliac graft, roof reconstruction using autologous bone,
• roof reconstruction using allograft,
• reinforcing ring in combination with autograft,
• cranial displacement of the acetabulum,
• medial displacement technique (cotyloplasty) with or without bone grafting.

An important point in installing the acetabular component, along with changing the center of rotation, is the degree of undercoverage of the upper part of the implant.

Hip reconstruction methods:

• lowering the hip with external devices,
• shortening of the femur through a modified lateral approach,
• transtrochanteric osteotomies, osteotomy according to Paavilainen,
• double chevron osteotomy,
• subtrochanteric osteotomies, distal femoral osteotomies.

The shortening osteotomy according to Paavilainen is most often used for hip reconstruction at the R.R. Vreden Russian Research Institute of Traumatology and Orthopedics. When analyzing mid- and long-term results, mean Harris Scores increased from 41.6 (95% CI 40.3 to 43.5) to 79.3 (95% CI 77.9 to 82.7). Early complications amounted to 9% (the most common were cracks of the proximal femur), late complications - 16.7% (falsearthrosis and delayed consolidation of the greater trochanter - 13.9%; dislocations - 1.1%; aseptic loosening of components - 1.7 %), repeated surgical interventions were performed in 8.3% of cases.

General recommendations

Children with a high risk factor for dysplasia are recommended to visit an orthopedist once every six months or according to an individual schedule prescribed by a doctor. During this period, you should engage in physical therapy and make full use of the capabilities of the hip joints.

Other recommendations for the prevention of dysplasia in children:

• Use special backpacks, slings, car seats. In them, the child’s torso takes the correct position and is not deformed.
• For newborns, special wide swaddling techniques are used. They can be mastered at courses for expectant mothers or at a consultation with a pediatrician or orthopedist.
• Massage or lightly exercise your baby regularly. Knead all joints and bones by performing flexion, extension, rotation and abduction movements.
• To securely fix your baby’s legs, discuss with your doctor an orthopedic device, for example, Pavlik stirrups.

Swimming lessons, visiting a gymnastics group, breathing techniques, and children's yoga are also suitable for prevention.