• The term developmental dysplasia of the hip (DDH); It includes all forms of the disease such as complete dislocation, incomplete dislocation (subluxation), and dysplasia.
• In DDH, the relationship between the femoral head and the acetabulum is impaired or disappeared.
• Therefore, defective structural formation in the acetabulum and proximal femur worsens as treatment is delayed.
• Factors that play a role in the etiology of DDH:
Mechanical structural factors
Connective tissue laxity
Capsular structure and acetabular structures such as labrum, pulvinar, ligamentum teres, transverse acetabular ligament
First born baby
Baby girl
Mechanical factors
breech birth
Oligohydramnios
Multiple pregnancy
postpartum position
Positive family history
• Other accompanying musculoscleteal anomalies such as torticollis, metatarsus adductus, pes calcaneovalgus
• Any situation where hips are forced to extension and adduction such as swaddling (physiological position for newborn baby hips is flexion and abduction)
Clinical Evaluation
• Restriction of abduction is a very reliable imaging method and is a very important finding encountered in all age groups, especially in unilateral DDH cases. However, abduction limitation may be misleading in bilateral dislocations.
Newborn Period
In the neonatal period, Ortolani tests, which show the reducibility of the hip, and Barlow tests, which show its removability, can be used.
Post-Newborn Period
It should be checked whether there is asymmetry in the thigh and inguinal pleats.
The Galeazzi-Allis (Ruler) sign is defined as an unevenness in the height of the knees and a lower knee on the dislocated side when viewed from the opposite side while the patient is lying on his back and the hips and knees are flexed .
In bilateral dislocations, pili asymmetry or Galeazzi-Allis sign may be misleading.
In a walking child
Recent studies have shown that there is no delay in walking in children with DDH.
In unilateral dislocation in a walking child, the affected side is short and the trunk tilts to the opposite side (Trendelenburg gait).
When standing on the dislocated side, the pelvis tilts to the opposite side due to the relative weakness of the gluteus medius muscle on the dislocated side (Trendelenburg sign).
The walking child has bilateral Trendelenburg gait (ducklike gait) and increased lumbar lordosis in bilateral dislocation.
Radiology
• In the first 4 weeks of life (in the neonatal period), ligament laxity can be seen physiologically.
• Since USG evaluation alone can be misleading in this period, evaluation together with physical examination findings will be more accurate.
• Since the newborn hip is predominantly cartilaginous, it is difficult to evaluate with direct radiography as a radiological examination.
• Hip ultrasonography (USG) reveals the acetabulum-femoral head relationship best in this period, and hip USG is the gold standard for radiological diagnosis, especially in the first 6 months of life.
• The most important aspects of hip USG are that it allows rapid and accurate diagnosis and is not harmful to the baby since it does not contain x-rays.
• The negative aspects are that it is a method that requires experience and because it is sensitive, it may cause extra treatment, especially in the early neonatal period.
• Anteroposterior pelvic X-ray is extremely important and is the gold standard after 6 months.
• Shenton Menard's line, evaluated on the pelvic X-ray, is an arc-shaped line starting from the lesser trochanter and continuing with the femoral neck and the upper border of the obturator foramen (internal border of the pubis).
• Normally, this line should be in the form of a continuous arc, but in cases with DDH, the continuity of this line is disrupted.
Treatment
• Especially the first 2-3 months of life are very important in treatment.
• In the first 6 months, dynamic or static orthoses (Pavlik bandage) that keep the hip in abduction and flexion are treated.
• There is no place for abundant tweezers in current DDH treatment.
• Pavlik bandage application (Figure 6) or Pavlik method, which is a dynamic method, is primarily preferred.
• Ilfeld-Craig and Von Rosen static orthoses have high success and low complications.
• After 6 months, treatment with conservative methods has a lower chance of success, and the child's treatment is often done in the hospital and in the operating room.
• Closed or open reduction of the hips is performed primarily between 7-18 months, or in the first 6 months when conservative methods fail.
• Plaster application (hyperabduction plaster) is performed under general anesthesia for closed reduction of the hip and subsequent preservation of reduction.
• Open reduction is performed after unsuccessful closed reduction.
• In open reduction, extra-articular and intra-articular soft tissue barriers that prevent the femoral head from entering the acetabulum are surgically removed.
• The limit for osteotomy surgery is 18 months in cases that do not benefit from open reduction.
• Avascular necrosis (AVN) is the most important complication that causes problems in the long term after treatment and leads to degenerative joint disease in the long term.
• AVN is a completely treatment-related complication and can be prevented.