Hip Ankylosis in Young Children: Osteo-Arthroplasty Reconstruction Versus Cephalobturator Neoacetabuloplasty and Classification

Abstract

Background and context. The appearance of a bony ankylosis in a preschool child, located at the level of the hip, is a disabling, extremely severe complication. In the medical literature, this problem was not addressed directly, and in medical practice, the therapeutic conduct is limited to subtrochanteric directional osteotomies to correct the position of the pelvic limb and hip endoprosthesis (replacement) surgery in teenagers.

Purpose. The paper compares and presents the effectiveness of surgical treatment in children with complex forms and severe complications following operated developmental dislocation of the hip. It proposes a differentiated approach to hip ankylosis and the choice of reconstruction technique, either through reconstitution of the acetabulum or by constructing a new joint.

Also this communication is to make known two innovative surgical interventions, hip osteoarthroplasty reconstruction (HOR) and cephalobturator neoacetabuloplasty (CN), useful in the treatment of hip ankylosis in young children.

The two interventions present some data on indications and intra- and postoperatively beneficial effects. The paper also includes the classification of hip ankylosis, as a useful tool in the choice of HOR versus CN.

There is an indissoluble link between the two surgical interventions and the classification of ankylosis. Knowing them allows a better understanding of this subchapter and extends the indications for CN.

The classification serves as a guide for practitioners and provides notions about the type and incidence rate of ankylosis in diseases that affect the hip.

Study design. Analysis and synthesis of data observed in a period of 49 years of practice in paediatric orthopaedic surgery.

Patient sample. The study sets out the knowledge gathered from the medical literature and the experience acquired during the years 1990-2023, on a group of 143 patients (164 hips).

HOR was performed on 138 patients (164 hips) and CN was performed on 5 patients, 3 presenting hip dislocation amid cerebral palsy with spastic paraparesis and 2 with developmental dislocation of the hip after two reluxations. Extensive chondrolysis at the level of the femoral head or the acetabulum revealed that plastic osteoarthroplasty reconstruction was contraindicated. In these cases, replacing the dislocation would have been equivalent to arthrodesis of the hip, an inadmissible attitude in young children.

Method. All patients underwent radiological and imaging investigations and benefited from physical therapy to determine the real limits of movement. Before the surgical intervention, the range of hip motion was assessed, and the type of ankylosis was determined. All types of ankylosis found in the patients were included in the general classification of ankylosis.

Results. After the first open reduction surgery and first relaxation, no patient had a second reluxation, femoral head necrosis or ankilosis. After the second reluxation (third intervention), 12 patients (16 hips), 9 years after the surgery, had signs of limited ankylosis and 3 hips had other complications with minor clinical manifestations; discomfort during intense and prolonged exertion, oblique pelvis without limping, and painless lumbar scoliotic deviation.

Conclusion. HOR corrects all deformities in complex forms of developmental dislocation of the hip in a single surgical stage: acetabular dysplasia, femoral head anteversion and deformation, muscle imbalance, and allows the transposition of the acetabular portion with minimal hyaline cartilage in the weight-bearing surface. 

CN configures a new hip joint.

The classification of ankylosis is a guide for the choice of subtrochanteric osteotomy, osteoarthroplasty reconstruction or cephalobturator neoacetabuloplasty as a therapeutic solution in the treatment of ankylosis in preschool children.