Minor change in the sulcus angle during the first six years of life: a prospective study of the femoral trochlea development in dysplastic and normal knees.

PURPOSE: The aetiology of femoral trochlear dysplasia is unknown. The aim of this prospective cohort study was to describe trochlear development in a newborn population during the first six years of life. METHODS: In an earlier study, the femoral trochlea was examined by ultrasound in 174 newborns. A dysplastic trochlea was defined with a sulcus angle (SA) above 159°. Two groups were defined, one group of 15 knees with SA > 159° (dysplastic group), and one group of 101 knees with SA < 159° (non-dysplastic group). In the present follow-up study, the children were further examined at six, 18 and 72 months. RESULTS: There was a statistically significant difference in the SA between the dysplastic and the non-dysplastic group at all follow-ups (p < 0.001). A small but statistically significant change in the SA between 0 to 72 months was detected for the dysplastic knees (p = 0.032) and for the controls (p < 0.001). CONCLUSION: Only minor changes in the anatomy of the femoral trochlea from newborn to age six years were found. A dysplastic trochlea at birth remains shallow and the anatomy does not change from normal to dysplastic during the same time span. LEVEL OF EVIDENCE: II.

Universal or selective screening of the neonatal hip using ultrasound? A prospective, randomised trial of 15,529 newborn infants.

The aim of this study was to evaluate whether universal (all neonates) or selective (neonates belonging to the risk groups) ultrasound screening of the hips should be recommended at birth. We carried out a prospective, randomised trial between 1988 and 1992, including all newborn infants at our hospital. A total of 15 529 infants was randomised to either clinical screening and ultrasound examination of all hips or clinical screening of all hips and ultrasound examination only of those at risk. The effect of the screening was assessed by the rate of late detection of congenital or developmental hip dysplasia in the two groups. During follow-up of between six and 11 years, only one late-detected hip dysplasia was seen in the universal group, compared with five in the subjective group, representing a rate of 0.13 and 0.65 per 1,000, respectively. The difference in late detection between the two groups was not statistically significant (p = 0.22). When clinical screening is of high quality, as in our study, the effect of an additional ultrasound examination, measured as late-presenting hip dysplasia, is marginal. Under such circumstances, we consider that universal ultrasound screening is not necessary, but recommend selective ultrasound screening for neonates with abnormal or suspicious clinical findings and those with risk factors for hip dysplasia.

Good results after treatment with the Frejka pillow for hip dysplasia in newborns: a 3-year to 6-year follow-up study.

Because there is no consensus with regard to the efficiency of the Frejka pillow in the treatment of hip joint dysplasia in newborns, the aim of the present study was to evaluate our results with this device. During the 3-year period 1988 to 1990, the Frejka pillow was used in 108 newborns with clinically unstable hips verified by ultrasonography. There were three treatment failures (2.8%), defined as infants who needed additional treatment with an abduction splint or hip-spica cast. Avascular necrosis of the femoral head occurred in one patient (0.9%). At an age of 3 years to 6 years, 85 of the children attended a follow-up examination. An intoeing gait was observed in 17% and slightly reduced hip mobility in 20% of the patients. Compared with normal children, the patients had somewhat lower coverage of the femoral head by radiography, indicated by a lower centre-edge angle and a higher migration percentage, but the coverage was within the normal range in all cases. The mean anteversion angle was larger than that of normal children but only three patients had abnormally high anteversion angles. In conclusion, the results with the Frejka pillow were good, with few treatment failures and complications, and it is the most simple abduction device for the parents to handle. More rigid devices like the von Rosen splint seem to involve a slightly lower failure rate, but a higher risk of avascular necrosis. Therefore, we recommend the Frejka pillow when treatment is started within a few days of birth.

The natural history of hip abnormalities detected by ultrasound in clinically normal newborns: a 6-8 year radiographic follow-up study of 93 children.

Ultrasound screening for hip dysplasia or dislocation has revealed a group of children with clinically normal hips, but with abnormal or suspicious ultrasound. During the 3-year period 1988-90, we found 170 children with this combination. We evaluated the natural history of these hips. 93 children were examined clinically and with standard radiography 6-8 years after birth. The center edge (CE) angle of Wiberg and migration percentage (MP) were measured on the radiographs. 87 children had not undergone any treatment, whereas treatment with an abduction orthosis had been initiated at approximately 4 months of age because of persisting dysplasia in 6 cases. All hips were radiographically normal at this follow-up. The mean CE value was 24 degrees (SD 6.5) and the mean MP was 13% (SD 5.2). 73 children had no complaints in their lower extremities, whereas 12 had intoeing gait, 1 had outtoeing gait, 2 had hip or knee pain, and 5 had other complaints not relevant to hip dysplasia. We conclude that infants with sonographically abnormal or suspicious hips, but with normal clinical findings, do not need immediate treatment because spontaneous resolution occurs in most of them. Postponement of treatment in the few with persistent dysplasia does not seem to affect the outcome.

The use of ultrasound in determining the initiation of treatment in instability of the hip in neonates.

We have evaluated the effect of the use of ultrasound in determining the initiation of treatment in neonatal instability of the hip. A total of 99 newborn infants (1.5% of all live births) with neonatal hip instability did not have treatment from birth, but were re-examined at eight to 15 days. In the 31 who had persisting clinical instability and ultrasound abnormality, treatment was then started with a Frejka pillow. The hips in the remaining 68 infants showed spontaneous clinical stabilisation and improvement of the ultrasound findings. Treatment was therefore withheld. There was a marked trend towards normal development in mildly unstable hips, whereas no hips with severe instability did so spontaneously. Further follow-up showed normal development in all the hips which had been treated, and in all except five of the 68 untreated infants. These five infants showed persistent hip dysplasia on both ultrasound and radiological examination at four to five months of age. Treatment with an abduction splint was then started and their hips developed normally. Ultrasound is very useful in deciding on treatment if the examiners have adequate experience with the method. Its use substantially reduces the rate of treatment. Spontaneous resolution occurred in more than half of the unstable hips. Since five of the untreated infants developed hip dysplasia a strict follow-up is essential to identify and treat these cases.

Ultrasonography of clinically unstable hips. A prospective study of 143 neonates at birth and early follow-up.

We evaluated the ability of ultrasonography to reduce the treatment rate of hips with clinical instability or uncertain findings at birth. Among 9,514 live births during the period 1988-1990, unstable hips were detected in 143 neonates by the Ortolani and Barlow tests, whereas the physical examination was inconclusive in 59 cases. These 202 neonates were also examined by ultrasound and instability was confirmed in 108 neonates who were treated with the Frejka pillow. The mean femoral head coverage (FHC) was 37%, indicating slight subluxation in the majority of unstable hips. The remaining 94 infants had normal ultrasonographic findings and were not treated. Their mean FHC was 53% and all these hips developed normally, except in 2 girls, who were treated with an abduction splint from age 4-5 months because subluxation developed. We conclude that ultrasound improved the reliability of the neonatal hip evaluation, thus markedly reducing the number of treated infants. Sonography also reduced the use of radiography during followup.

Relationship between symptoms of jumper's knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players.

This study assessed the ultrasound characteristics of the patellar tendon in two groups of volleyball players, one group without knee symptoms and one group with symptoms of jumper's knee. Of 47 male elite players, 25 were diagnosed to have current and seven to have had previous symptoms of jumper's knee, as determined by clinical examination. Since some players had bilateral problems, there were 34 knees with current problems and nine with previous problems. Seven of the 30 knees with a clinical diagnosis of jumper's knee in the patellar tendon had normal ultrasound findings, and ultrasound changes believed to be associated with jumper's knee (tendon thickening, echo signal changes, irregular paratenon appearance) were observed in 12 of 51 knees without symptoms. Specific ultrasound findings such as paratenon changes, hypoechoic zones or pathological tendon thickness proximally did not correlate significantly with the degree or the duration of symptoms. This study suggests that the specificity and sensitivity of ultrasonography is low in the evaluation of patients with mild symptoms of jumper's knee.

Hip abnormalities detected by ultrasound in clinically normal newborn infants.

We have followed the natural progress of newborn infants in whom ultrasound examination showed abnormalities in hips which appeared to be clinically normal. Over six years we saw 306 such children out of 9952 examined (31 per 1000 live births). The examination was repeated at two to three months and those who still showed an abnormality were followed up further. At four to five months a standard radiograph was obtained, and treatment began if this and another ultrasound scan were both abnormal. At this stage, 291 infants had normal hips. In the 15 infants with abnormal hips there was no pronounced deterioration, none developed a frank dislocation, and all became normal after treatment in an abduction splint. Newborn infants with abnormal and suspicious ultrasound findings who are normal on clinical examination do not need treatment from birth; most of these hips will settle spontaneously. Treatment can be postponed until the age of four to five months unless clinical instability develops or ultrasound shows dislocation. The criteria for treatment should be based on measurements by both ultrasound and radiography: both should show an abnormality before intervention is considered necessary.

Ultrasonographic evaluation of breech presentation as a risk factor for hip dysplasia.

In order to gain more information of breech position as a risk factor for congenital hip dysplasia or dislocation, the hips of 408 newborns delivered in the breech position were examined by ultrasound. Clinical examination was performed by both experienced paediatricians and orthopaedic surgeons. The infants were re-examined by ultrasound at 2-3 months of age. Twenty-five newborns (6.1%) had neonatal hip instability. Breech presentation as a risk factor was confirmed, with first borns, breech position with extended knees, and high birthweight as special high-risk groups. Ultrasound showed subluxation in most of the unstable hips. The main benefit of using ultrasound was that direct visualization permitted more reliable evaluation, especially when the clinical findings were uncertain. Normal ultrasound findings in false positive and uncertain Ortolani tests reduced the frequency of unnecessary treatment. Because ultrasound was used in follow-up, the need of radiography was reduced. There were no late-detected cases of hip dysplasia or dislocation, indicating that routine follow-up is not necessary in breech infants with normal hips at birth, provided that the neonatal screening is optimal.

Surgical treatment of medial tibial stress syndrome (shin splint) by fasciotomy of the superficial posterior compartment of the leg.

From September 1988 to June 1990, 35 athletes were treated for medial tibial stress syndrome (shin splint) by fasciotomy of the superficial posterior compartment of the leg. Thirty-two patients were available for the follow-up, including self-assessment, clinical examination and activity scoring. The mean postoperative observation time was 16 months. Thirteen patients were performing sports at top international or top national level; 19 patients were competing at different lower levels. Twenty-three patients improved, 7 were unchanged and 2 had poor results.

Intercondylar notch width and the risk for anterior cruciate ligament rupture. A case-control study in 46 female handball players.

We measured the intercondylar notch of the femur in female handball players from radiographs of 20 players with previous unilateral anterior cruciate ligament injury, and 26 controls without injury. The groups were comparable regarding age, height, weight and level of performance. Intercondylar fossa radiographs were obtained in a posteroanterior axial position. The anterior opening of the intercondylar notch was narrower in the healthy knee of the injured group compared to the controls. There was an increased risk of anterior cruciate ligament injury associated with decreasing notch opening: female handball players with 17 mm or less anterior notch width were 6 times more susceptible to anterior cruciate ligament injury compared to players with wider notch width.

Ultrasound screening for hip dysplasia in newborns.

We evaluated risk factors for neonatal hip instability (NHI) at birth using ultrasonography and assessed the reliability of our ultrasound method by means of an interobserver study. The hips of 4,459 newborns were examined by ultrasound from 1988 to 1990. The ultrasound evaluation was based mainly on measurement of femoral head coverage (FHC) by the bony acetabular roof. The mean FHC was 56% in boys and 54% in girls (a significant difference). Fifty-five newborns with unstable hips had a mean FHC of 37%, which was significantly lower than that of the normal hips. Known risk factors for NHI were confirmed (breech position, family history of hip dysplasia, increased birth weight), but no new risk factors were detected. The interobserver study included 200 hips. The 95% confidence limit for interobserver variation in FHC (+/- 2 SD) was +/- 8%. Because of this moderate interobserver variation, and because the incidence of late-detected hip dysplasia was low (0.2 per 1,000), we conclude that our method for ultrasound examination is sufficiently reliable for screening of hips in newborns.

Activation of the complement system and adverse effects of biodegradable pins of polylactic acid (Biofix) in osteochondritis dissecans.

Biodegradable pins of polyglycolic acid (PGA) or polylactic acid (PLA) have been used in the treatment of fractures and osteotomies during the past 5 years. Adverse effects reported have included swelling at the implantation site and sinus formation, considered to represent nonspecific foreign-body reactions. Recent reports, however, have shown severe reactions after intraarticular fracture fixation. Reactions in 2 patients, treated with polylactic pins for osteochondritis dissecans (OCD) in our hospital, prompted the present clinical investigation and further evaluation of the complement-activating potential of polylactic pins. 10 knees underwent arthroscopic fixation of an OCD-lesion with Biofix (PLA) pins. Clinical follow-ups were carried out at 2, 6, and 12 weeks and at 6 and 12 months. Blood samples were collected from 5 patients 9-24 months postoperatively for biocompatibility tests. Quantification of human C5a des Arg was performed with a recently developed sandwich ELISA technique, using neoepitope-specific monoclonal antibodies. 6 knees developed diffuse swelling and a prolonged postoperative course. 2 patients had a particularly prolonged course which could not be attributed to infection. Levels of C5a des Arg in plasma incubated in the presence of polylactic acid were higher than in plasma incubated in the absence of PLA. The high frequency of long-term postoperative inflammatory signs in these knees treated for OCD and the demonstration of a complement activation potential of PLA pins warrant further studies on the biocompatibility of this material. Until more information is available, we do not recommend intraarticular use of PLA pins.