[Dysplasia in the development of the hip]. / Displasia del desarrollo de la cadera.

Developmental dysplasia of the hip (DDH) causes anatomical changes that cause early coxarthrosis. Although risf factors have been determined, the aetiology and physiopathology remains exactly unknown. Neonatal screening with physical examination and ultrasound have been stablished in order to diagnose this disease early in life. A diagnosis in the first months of life is essential as it enables a normal hip to form and prevent the appearance of early coxarthrosis. Treatment principles are to be able to reduce the hip without provoking avascular necrosis of the femoral head, and to normalize the acetabular development. Knowledge of the orthopaedic and surgical options is essential in order to achieve success in the treatment.

Acetabular dysplasia after treatment for developmental dysplasia of the hip. Implications for secondary procedures.

Untreated acetabular dysplasia following treatment for developmental dysplasia of the hip (DDH) leads to early degenerative joint disease. Clinicians must accurately and reliably recognise dysplasia in order to intervene appropriately with secondary acetabular or femoral procedures. This study sought early predictors of residual dysplasia in order to establish empirically-based indications for treatment. DDH treated by closed or open reduction alone was reviewed. Residual hip dysplasia was defined according to the Severin classification at skeletal maturity. Future hip replacement in a subset of these patients was compared with the Severin classification. Serial measurements of acetabular development and subluxation of the femoral head were collected, as were the age at reduction, type of reduction, and Tonnis grade prior to reduction. These variables were used to predict the Severin classification. The mean age at reduction in 72 hips was 16 months (1 to 46). On the final radiograph, 47 hips (65%) were classified as Severin I/II, and 25 as Severin III/IV (35%). At 40 years after reduction, five of 43 hips (21%) had had a total hip replacement (THR). The Severin grade was predictive for THR. Early measurements of the acetabular index (AI) were predictive for Severin grade. For example, an AI of 35 degrees or more at two years after reduction was associated with an 80% probability of becoming a Severin grade III/IV hip. This study links early acetabular remodelling, residual dysplasia at skeletal maturity and the long-term risk of THR. It presents evidence describing the diagnostic value of early predictors of residual dysplasia, and therefore, of the long-term risk of degenerative change.

Pediatric stress fractures.

Stress fractures in children are uncommon. This report describes the findings of 8 cases in 6 children. One patient had 3 stress fractures: 2 consecutive midshaft stress fractures of the same tibia associated with one of the fibula. Signs and symptoms may be misdiagnosed as malignant tumors or osteomyelitis. Serial radiographs and computed tomography scans are the key to the diagnosis, although bone scan and magnetic resonance imaging can be helpful. Biopsy is unnecessary and might even be misleading.

Unusual finding after contrast injection of a solitary bone cyst. A case report.

Injection of radiopaque contrast into a solitary bone cyst (SBC) prior to methylprednisolone acetate (MPA) injection has been previously reported. We report an unusual finding during the injection of radiopaque contrast in the treatment of one case of SBC of the femur: a bicameral appearance of the cyst was observed; no filling of the proximal cavity occurred and immediate perfusion of the femoral vein with contrast was noted. In cases of SBC such as this one, percutaneous autologous marrow or corticosteroid injection may fail to be effective. Furthermore there exists the potential risk of fat embolus secondary to bone marrow injection. Based on these findings in the case reported, we suggest that contrast injection should be performed prior to bone marrow or corticosteroid injection in order to evaluate both the venous drainage of the cyst and its degree of loculation.

Correlative study between arthrograms and surgical findings in congenital dislocation of the hip.

The arthrogram plays an important role in the diagnosis and treatment of congenital dislocation of the hip (CDH), because congrous reduction has been related with hip outcome. We have reviewed 29 children younger than 1 year of age (34 hips) diagnosed and treated in our hospital for CDH, and we have recorded three radiologic parameters: acetabular index, acetabular floor thickness, and grade of dislocation. We also have evaluated three surgical and arthrogram findings (limbus, ligamentun teres, and transverse ligament) in order to study their statistical correlation, and consequently, to evaluate arthrogram usefulness. Results show a significantly high acetabular index and floor thickness as secondary to absence of femoral head.

Five additional cases of local fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia has previously been described as an etiology of genu varum deformity in children at about walking age. We have found 20 cases in the literature, and all of them were located in the medial proximal tibial metaphysis. We report five additional cases of this entity. The patients had a genu varum deformity, and the angulation was at the site of the bone lesion. Four cases were in the tibia, and one case was in the distal medial femoral metaphysis. Age at diagnosis ranged from 13 to 24 months. A cortical defect with surrounding sclerosis was observed on radiographs. The angulation usually progressed initially, and spontaneous resolution was observed in two cases at last follow-up. Open biopsy and tibial valgus osteotomy were performed in two cases. The unusual femoral case was also treated with open biopsy and medial hemicircumferential periosteal release. Spontaneous remodeling of varus angulation and resolution of bony defect may be expected in most cases, and osteotomy can be avoided.

The teardrop in congenital dislocation of the hip diagnosed late. A quantitative study.

We retrospectively reviewed the radiographs of the pelvis and hips of forty-five patients who had unilateral congenital dislocation of the hip treated with closed reduction and application of a cast without subsequent operations. The radiographs were made at the time of the initial diagnosis, two years after the reduction, when the child was ten years old, and at skeletal maturity. The width, shape, and type of the teardrop; the thickness of the acetabular floor; the acetabular index; the center-edge angle; the articulotrochanteric distance; and the Severin class at maturity were measured in the dislocated and contralateral, normal hips. At the time of the initial diagnosis, a well defined teardrop was seen in thirty-six (80 per cent) of the normal hips and in seven (16 per cent) of the dislocated hips. There was no difference in the width of the teardrop in the seven dislocated hips compared with that in the normal hips, although the v-shaped and crossed types of teardrops were more frequent in the dislocated hips. The v shape was not observed in the normal hips but was seen in sixteen dislocated hips two years after the reduction and in twelve dislocated hips when the children were ten years old. The superior and inferior widths of the teardrop of the dislocated hips were significantly greater than those of the normal hips (p < 0.001 and p < 0.05, respectively) when the children were ten years old. The hips with residual acetabular dysplasia had a v-shaped teardrop, widening of the superior width of the teardrop, and thickening of the acetabular floor. These hips, which were usually Severin class IV at the time of skeletal maturity, had a poor prognosis in adult life.

Radiologic pelvic asymmetry in unilateral late-diagnosed developmental dysplasia of the hip.

Eighty-three cases of unilateral late-diagnosed (older than 4 months of age) developmental dysplasia of the hip (DDH) were studied to evaluate pelvic shape and innominate bone relationships in the initial anteroposterior radiograph. To be included, each initial radiograph had to have no lumbar pedicle rotation, lumbar scoliosis, gas shadows, or metallic protectors. Measurements were done using as reference a medial pelvic line, which divides the pelvis into two innominate bones. Lineal parameters were defined to assess pelvic radiologic shape; angular parameters defined the relationship between the ilium, ischium and pubis, and sacrum. Statistically significant differences were observed in most cases, and pelvis asymmetry was evident. The asymmetry was more obvious in cases in which the teardrop had a negative value and in low dislocations. Similar changes have been observed in experimental dislocation of the hip secondary to a triplane pelvic deformity. We suggest that similar alterations of pelvic shape occur in DDH, possibly secondary to growth disturbance in the triradiate cartilage.

Femoral head avascular necrosis associated with metaphyseal aneurysmal bone cyst.

A 12-year-old girl had an aneurysmal bone cyst in the proximal femoral metaphysis simultaneously with an avascular necrosis of the femoral head, as seen on radiological examination. No extension of the lesion across the growth plate into the femoral epiphysis was observed. The expansive behavior of this lesion (ABC) could have compromised the posterosuperior vascular supply of the femoral epiphysis, since no radiographic signs of fractures could be found. Vascular anomalies within the lesion that increase venous pressure could be another factor responsible for the decrease in the blood supply of the femoral epiphysis and could cause necrosis, hence compromising the morphology of the hip joint at maturity.

Children at high risk for congenital dislocation of the hip: late presentation.

Several studies of risk factors and screening for congenital dislocation of the hip (CDH) have been reported, but some children are diagnosed too late and poor prognosis can be expected even with selective screening programs. The frequency of risk factors in late CDH presentation is not known.

Problems encountered in leg shortening.

We reviewed 46 leg-shortening operations (37 femoral and nine tibial), performed by different methods, to assess the incidence of complications and permanent disability. Shortening of as much as 7.5 cm in the femur and 5 cm in the tibia was achieved in men of normal height without any loss of function. Complications were seen with all surgical techniques despite the use of modern implants. Most problems arose from inadequate stabilisation of the osteotomy. The most reliable method of femoral shortening was open subtrochanteric osteotomy with preservation of the isthmus, and fixation with an intramedullary nail locked at its proximal end. In tibial shortening, bone excision should be at the level of the flare in the lower diaphysis in order to achieve reliable bone healing. Simple intramedullary nail fixation should be supplemented with a long-leg cast for six weeks or the nail should be locked at both ends to prevent postoperative distraction or rotation.