DEVELOPMENTAL DISORDERS OF THE HIP TREATED AT THE CLINIC FOR ORTHOPAEDIC DISEASES – IN A PERIOD OF 10 YEARS (2009-2018)

All of the patients were treated with conservative treatment-closed reducation and spica casting. Left-sided dislocations were more common than right sided dislocations with predominance in the female patients. The main treatment in follow-up patients was closed reduction with or without adductor muscle tenotomy (m. add. longus). In cases with unsuccessful attempt of closed reduction, open reduction was performed with or without adductor muscle tenotomy. Depending on the residual dysplasia, patients were additionally treated with pelvic osteotomies (Salter ‚s inominate osteotomy), varus derotation osteotomy, valgus osteotomy, proximal femoral resection, and trochanter major transposition. 167 patients were treated with closed reduction and 3 with open reduction. The remaining patients were treated with closed reduction and additional surgery or with open reduction and additional surgery. Out of all treated patients, only 10 patients had recurrent dislocation of the hip, 7 female and 3 male patients. Closed reduction was performed again on two patients, and open reduction of the hip was performed on one patient. The average age of patients was 21.5 months. By presenting the cases in a period of 10 years, it was conclud that most cases were diagnosed later. Also, the standard closed reduction treatment was successful even after the first year in said patients. Depending on the residual dysplasia of the hip, in order to achieve better congruence of the joint, additional surgeries were performed. Abstract


DEVELOPMENTAL DISORDERS OF
If the closed reduction is unsuccessful, open reduction of the hip is performed. Depending on the condition of the dislocated hip and the subsequent dysplasia, several surgical treatments are sometimes needed in order to obtain a congruent joint. 1 There are many complications that can arise from the treatment of developmental dysplasia. One of the most serious complications is avascular necrosis (AVN) of the femoral head in children who are inadequately treated with maximal hip abduction. AVN is most often caused iatrogenically. 3 The main iatrogenic causes of AVN are disorders of the circulation of the head, necrosis of the head due to pressure thereon, traction, the force with which the reposition is performed, the position of the immobilization after the "frog leg position" reposition, the ossification of the nucleus and the position of the femoral head, as well as the use of the Hilgenreiner brace. 7 The аim of this paper is to present the treatment of developmental disorders of the hip at the Clinic for Orthopedic Diseases in Skopje.

Materials and methods
In the period 2009-2018, a total of 242 patients were included and treated in our study, whereas 44 male and 198 female patients were noted. The patients were treated at the Clinic for Orthopedic Diseases in Skopje.

Discussion
The papers of Sewell, Clarke N. M et al., show that the ultrasound examination is the most reliable method for describing the anatomical characteristics of the hips of the children under 3 months of age. 8, 9 Screening is crucial for the early diagnosis and treatment of the developmental disorders of the hip, and it should begin in the maternity ward where clinical examination must be performed and advice for orthopedic examination must be given. AP radiography is important in diagnosing and confirming the diagnosis in children above 3 months of age; it is not necessary before the age of 3 months due to the fact that ossification nuclei of the femoral head begin to appear at the age of 4-6 months. 10 Acceptable manner of treatment of developmental dysplasia of the hip in the literature is graded from the least invasive treatment to increasing the invasiveness of the treatment. 2 Pavlik harness remains the most acceptable and the most used method in children with developmental dysplasia under 6 months of age, with a high success rate. Should the Pavlik harness fail to provide stability of the hip, the next step is closed reduction of the hip under general anesthesia and placement of abduc-tion plaster cast with flexion in the hips with or without arthrography. 10 The safe zone of Ramsey is the range between maximal passive abduction of the hip and the angle of abduction where the femoral head becomes unstable. Immobilization must not be placed in maximal abduction, because this increases the chances of AVN of the hip. 3,11 . The plaster cast immobilization is placed in 90-100 degrees of hip flexion and controlled abduction which is less than 70 degrees. 3 If the safe zone of Ramsey is wide, the hip is considered stably repositioned, while if greater abduction and internal rotation greater than 10-15 degrees are required to keep the hip in the acetabulum, it is considered unstable repositioning. 11 In order to increase safe zone that would allow greater abduction, an open or closed tenotomy of m. adductor longus was performed depending on the size of the adductor contracture. 11 After the successful closed reduction, the residual dysplasia of the hips, when necessary, is usually treated with Salter innominate osteotomy and, less frequently, with Pemberton osteotomy or Dega acetabuloplasty.
Varus derotation osteotomy is performed in cases of severe femoral anteversion. 12 If the closed reduction failed, then the next solution was open reduction of the hip, if necessary, with pelvic osteotomy or femoral osteotomy. 10

VRDO (Varus Derotation Osteotomy) 2
Derotation osteotomy+Salter innominate osteotomy 2 Salter innominate osteotomy 12 Extractio OSM (there is no data on the type of the performed operation) 10 The purpose of the treatment of developmental dysplasia of the hip is to keep the reduced hip in order to obtain a concentric shape of the femoral head for better congruence of the joint which will reduce the risk of early AVN which leads to early osteoarthrosis of the joint. 10 The rate of osteonecrosis of the femoral head after treatment with Pavlik harness ranged from 1% to 30% in the study of Al-Essa's. S. R et al. 10 The risk of developing osteonecrosis is high in Graf type IV hips or in patients where the dislocation was proven with an anterior-posterior view radiograph (AP). Initial treatment above 3 months of age, delay in ossification of femoral head at the beginning of the treatment, prolonged treatment accompanied by strong adductor contracture of the hip are risk factors for development of AVN of the femoral head. The rate of development of osteonecrosis of the contralateral healthy hip in cases where the dislocation is unilateral and that are treated with Pavlik harness is 2.9%. 6 According to the literature, after beginning to walk, i.e., above 2 years of age, direct open reduction of the dislocated hip should be performed.
The metacentric study of Morina C et al. shows results from 15 centers where a total of 222 cases were treated with closed reduction in the last 20 years. In 5.3% of patients the reduction was unsuccessful, 8% of the had recurrent dislocation or subluxation, and 4.7% of them had post-reduction osteochondritis. Successful open reductions of the hip were performed on 120 patients. 7% of them had recurrent dislocations and subluxations and 13% of them had post-reduction osteochondritis. 12 The study of Hayazi M Al Shehri et al. shows that the successful closed reduction in congenitally dislocated hips within the recommended age (4-15 months of age) results in improved acetabular development, i.e., formation of the acetabulum within a minimum of 12 months after the closed reduction. 13 Screening as a method of choice is confirmed by the fact that if abandoned, the rate of late detection will increase and there will be a significantly increased expected risk of avascular necrosis of the hips and less successful results, because the surgical treatment, i.e., the open reduction of the hips will be more common.

Conclusion
By presenting the cases within a period of 10 years in this study, we can conclude that most of the cases are diagnosed later, but also that the standard treatment of closed reduction is successful even in patients above one year of age. Surgical procedure of the acetabulum and the proximal femur is used to correct residual dysplasia. Open reduction can give rise to complications such as avascular necrosis of the femoral head (AVN).