Ultrasound in the selective screening of developmental dysplasia of the hip.

INTRODUCTION: Developmental dysplasia of the hip (DDH) can result in chronic pain, gait abnormalities and degenerative arthritis. Infants with a family history, Breech delivery or unstable/"clicking" of the hip on examination are at higher risk. The goal is to detect cases early enough for normal hip development and function by the end of adolescence, but clinical examination alone is ineffective. MATERIALS AND METHODS: All infants born at the West Middlesex University Hospital, Isle-worth, U.K., between 3/3/2005 and 21/10/2006 underwent prospective clinical screening to reveal risk factors of unstable hip on examination, family history of DDH and Breech delivery. Infants with risk factors underwent static and dynamic ultrasound of the hips (Harke's method with Terjesen measurements), performed by a consultant radiologist or sonographer. The infant was then examined by an Orthopaedic Surgeon who was blinded to the ultrasound findings until after creating a management plan. RESULTS: 5772 infants were born during the study period. 200 (3.5%) at-risk infants were identified, resulting in 400 hip ultrasounds. Following review of ultrasound findings, the majority of cases (163/200, 81.5%) lead to no change in management. Change in timing or type of clinical follow up occurred in 31 cases with normal ultrasounds and 20 cases with abnormal (immature hip) ultrasounds. Dysplasia was demonstrated in 6 infants (3%) on ultrasound, who were treated with Parvlik Harness. Of these, only 5 were detected on examination. Therefore, the ultrasound findings lead to 1 intervention with Parvlik Harness which would have otherwise gone undiagnosed from clinical examination. CONCLUSION: Whereas type and timing of follow up was adjusted in 18.5% of the at-risk infants, targeted screening of at-risk with ultrasound lead to only one intervention. This encourages discussion on the resource implication and viability of ultrasound screening, as only one from two hundred lead to an intervention.

Test of stability as an aid to decide the need for osteotomy in association with open reduction in developmental dysplasia of the hip.

After open reduction for developmental dysplasia of the hip (DDH), a pelvic or femoral osteotomy may be required to maintain a stable concentric reduction. We report the clinical and radiological outcome in 82 children (95 hips) with DDH treated by open reduction through an anterior approach in which a test of stability was used to assess the need for a concomitant osteotomy. The mean age at the time of surgery was 28 months (9 to 79) and at the latest follow-up, 17 years (12 to 25). All patients have been followed up until closure of the triradiate cartilage with a mean period of 15 years (8 to 23). At the time of open reduction before closure of the joint capsule, the position of maximum stability was assessed. A hip which required flexion with abduction for stability was considered to need an innominate osteotomy. If only internal rotation and abduction were required, an upper femoral derotational and varus osteotomy was carried out. For a 'double-diameter' acetabulum with anterolateral deficiency, a Pemberton-type osteotomy was used. A hip which was stable in the neutral position required no concomitant osteotomy. Overall, 86% of the patients have had a satisfactory radiological outcome (Severin groups I and II) with an incidence of 7% of secondary procedures for persistent dysplasia including one hip which redislocated. The results were better (p = 0.04) in children under the age of two years. Increased leg length on the affected side was associated with poor acetabular development and recurrence of joint dysplasia (p = 0.01). The incidence of postoperative avascular necrosis was 7%. In a further 18%, premature physeal arrest was noted during the adolescent growth spurt (Kalamchi-MacEwen types II and III). Both of these complications were also associated with recurrence of joint dysplasia (p = 0.01). Studies with a shorter follow-up are therefore likely to underestimate the proportion of poor radiological results.

Uncemented total hip arthroplasty with subtrochanteric derotational osteotomy for severe femoral anteversion.

Total hip joint arthroplasty (THA) in the presence of severe femoral anteversion (>50 degrees) is technically demanding. This problem is often encountered in patients with osteoarthritis secondary to hip joint dysplasia or congenital dislocation. We describe a method of THA in which an uncemented femoral prosthesis is used in conjunction with subtrochanteric derotational osteotomy. This technique allows the restoration of the normal proximal femoral anatomy, including the abductor muscle lever arm without resorting to greater trochanteric transfer. Correction of the excessive femoral anteversion avoids the tendency for postoperative anterior instability. The osteotomy site may also serve as the site for femoral shortening or angular correction when required, which preserves the normal femoral flare. The prostheses used were custom CAD/CAM (computer-assisted design/computer-assisted manufacturer) in design and had the following features: a close intramedullary proximal fit, with collar, lateral flare, and hydroxyapatite coating to achieve early proximal fixation, and longitudinally cutting fluted stem to provide immediate rotational stability across the osteotomy site. Although we used CAD/CAM custom prostheses, off-the-shelf uncemented hip prostheses with similar design features have become available. We report on 7 patients who underwent THA using this technique. The average patient age was 49 years (range, 34-61 years) with a mean follow-up period of 31 months (range, 16-60 months). To date, all cases have had a satisfactory outcome with evidence of union at the osteotomy site. Harris hip scores improved from an average of 44 preoperatively to 91 by the end of follow-up period. One case was complicated by delayed union at the osteotomy site, which was successfully corrected with bone grafting and temporary plate stabilization.

Ionising radiation: are orthopaedic surgeons' offspring at risk?

The hazards of exposure to ionising radiation are well documented. Fears have been raised that occupational exposure to ionising radiation by orthopaedic surgeons may have detrimental effects on the future health of their unborn offspring. The current members of the British Orthopaedic Trainees' Association and orthopaedic consultants appointed during the last 5 years in the United Kingdom were contacted using a postal questionnaire. Obstetricians and gynaecologists of a similar age group were also contacted to act as the control group. The collected data were compared with the latest national data as published by the Office of Population Censuses and Surveys for England and Wales (OPCS, 1991). In all, 504 questionnaires were posted to orthopaedic surgeons and 1597 to obstetricians and gynaecologists. Reply rates were 334 (66%) and 986 (62%), respectively. Our data reveal a higher rate of congenital abnormalities as compared with the normal population in both groups (P < 0.001). However, there were no statistically significant differences in the rate of congenital abnormalities between the offspring of orthopaedic surgeons and obstetricians and gynaecologists (P = 0.78). These findings suggest that the increased rate of congenital abnormalities observed in both groups is more likely to be associated with factors other than exposure to X-rays. In this study, male surgeons had a higher incidence of female children compared with the normal population (P = 0.01). The incidence of childhood malignancies does not appear to be raised in either group. These findings suggest that the current levels of occupational exposure to X-rays by orthopaedic surgeons is unlikely to be associated with an increased risk of congenital abnormalities or childhood malignancies in their children.

Absent superficial abdominal reflexes in children with scoliosis. An early indicator of syringomyelia.

We describe 12 children with idiopathic scoliosis who had a persistent absent superficial abdominal reflex (SAR) on routine neurological examination. MRI showed syringomyelia to be present in ten. The average age at detection of the scoliosis was 4.3 years and at diagnosis of syringomyelia 6.6 years. In all ten children the SAR was consistently absent on the same side as the convexity of the curve. In two it was the only abnormal neurological sign. An absent SAR in patients with scoliosis is an indication for investigation for underlying syringomyelia. In the children with syringomyelia, six had thoracic and four thoracolumbar curves. The clinical features differed in the two groups. Patients with thoracic curves were generally asymptomatic. Their neurological signs were subtle and none had any motor signs. By contrast, patients with thoracolumbar curves had symptoms and neurological signs. Abnormal gait was present in all four patients with thoracolumbar curves. In three this was due to considerable motor weakness. In eight children syringomyelia was associated with a Chiari-I malformation. In seven the syrinx was treated surgically by decompression of the foramen magnum.