Tendons adapt in response to sports‐specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium‐term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi‐annual ultrasound and clinical examinations (average follow‐up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P = 0.07) while quadriceps tendon thickness increased (P = 0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7–11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness.

Female soccer has become increasingly popular during the last two decades. According to the International Football Association (FIFA) there are approximately 40 million registered female soccer players in the world. Three studies in elite soccer have shown an injury incidence during games ranging from 12.6 to 23.3 injuries per 1,000 h. A very high incidence of ACL-injuries ranging from 0.31 to 2.2 per 1,000 game hours has also been shown. We followed the Norwegian female elite series during the 2001 season to estimate the incidence and characteristics of injuries. A total of 181 female soccer players on ten teams were followed during the 2001 elite season in Norway. We recorded baseline data, match and training exposure and injury data as type of injury, location and severity of injury. The mean age of the players was 23 years (range 17-34). A total of 189 injuries were recorded and 19 (10%) of these were overuse injuries; 89 (47%) occurred during games and 100 (53%) during training sessions. The incidence of acute injuries was 23.6 per 1,000 game hours and 3.1 per 1,000 training hours. The majority of the injuries occurred in the lower extremities (81%), but there were also a significant number of head injuries (6.3%). The most common injury type was ankle sprain (17.2%). Half of the injuries were minor, with training or game absence of less than 7 days. Midfielders sustained the most injuries (32.6%) with an incidence of 42.4 per 1,000 game hours. We recorded two ACL-injuries and two PCL-injuries during the season. They all occurred during games, and the incidence was therefore calculated to 0.6 per 1,000 game hours for both injury types. The incidences of injuries reported for female soccer varies considerably, with the highest numbers reported from Germany and the present study. These studies have also the highest incidence of minor injuries registered. The location of the injuries is quite similar compared to other reports, but the number of ankle sprains seems to be higher in our study, whereas the number of knee and thigh injuries is lower. There has been much attention to ACL injuries in team handball and hamstring injuries in soccer in Norway, and this could have influenced the team's pre-season training, resulting in a reduction in the incidence of these injury types. The high number of ankle injuries has to be addressed to see whether this is a result of inadequate rehabilitation routines leading to re-injuries, or other factors. The high number of ACL-injuries in these reports is alarming and needs special attention in the future.

Purpose: The purpose of the study was to evaluate the biocompatibility of polylactide (PLLA) screws in comparison with standard metal screws for fixation of the patellar tendon graft in human anterior cruciate ligament (ACL) reconstruction.Methods: A total of 41 patients (22 women and 19 men) were prospectively randomized for the use of metal interference screws (20 patients) or biologically resorbable PLLA screws from Linvatec, Largo, FL (21 patients). Average age at the time of surgery was 26 years (15 to 51 y). Synovial fluid and plasma were collected preoperatively and after 6 weeks in both groups. Plasma was analyzed for C5a and synovial fluid, as well as for terminal SC5b-9 complement complex (TCC) and interleukin (IL)-8. At 1 year after surgery, serum was incubated with metal, PLLA, and no screws; this was followed by analysis of C5a after 1 and 6 hours of incubation. Inflammatory mediators were measured through enzyme-linked immunosorbent assay (ELISA).Results: In the BioScrew group, 4 patient samples showed high C5a concentration in synovial fluid after 6 weeks, but no statistically significant difference was observed between the 2 groups (P = .11). One patient in the BioScrew group had a high TCC value after 6 weeks, but no statistically significant difference was seen between the 2 groups (P =.20). In the in vitro study, no increased C5a generation was observed in sera incubated with a BioScrew or a metal screw compared with controls.Conclusions: No statistically significant difference was observed between the BioScrew and metal screw groups concerning C5a, TCC, and IL-8 formation. However, some patients in the BioScrew group showed elevated values.Level of Evidence: Level II, prospective randomized trial.

Background During the past decade, bioabsorbable interference screws have become increasingly popular in endoscopic reconstructions of the anterior cruciate ligament. With these screws, there is no need for a second operation for removal and no complicating factor if later revision surgery is necessary. Several pullout studies have found similar results between metal and bioabsorbable interference screws; however, few studies have investigated the clinical outcome. Hypothesis There is no difference in the clinical outcome of bioabsorbable interference screws compared with metal screws. Study Design Randomized controlled clinical trial; Level of evidence, 1. Methods Forty-one patients were randomized for the use of either metal interference screws (20 patients) or bioabsorbable poly-L-lactic acid screws (21 patients). The patients were followed with clinical examinations at 6, 12, and 24 weeks and at 1 and 2 years postoperatively. Results Subjective knee function was better in the patients in the metal screw group; they had less pain at rest, a higher Tegner score, a higher Lysholm score, and better subjective knee function at 2 years compared to the bioabsorbable screw group. However, there was no difference in stability between the groups. Conclusion and Clinical Relevance Because of the inferior results in the bioabsorbable screw group in our study, and until larger studies show otherwise, we do not find the advantages of using bioabsorbable screws sufficient to warrant the routine use of poly-L-lactic acid screws in anterior cruciate ligament reconstructions.

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.

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.

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.

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.

Purpose: the aim of the present study was to assess whether ultrasonography (US) was reliable in the follow-up of children above 2 years of age who had previously been treated for congenital or developmental hip dislocation or dysplasia (HD). Material and Methods: As part of the routine follow-up, we examined 53 children (106 hips), aged 2–12 years (mean 6 years). Using US, the coverage of the femoral head was assessed by the distance from the lateral tangent of the ossified femoral head to the lateral bony acetabular rim (lateral head distance, LHD). the corresponding distance was measured on radiographs (LHDR). the radiographic femoral head coverage was assessed by the migration percentage (MP) and the center-edge (CE) angle. Results: We found a good accordance between sonographic LHD and the radiographic parameters MP and CE in all age groups, indicating that femoral head coverage was reliably assessed by US. There was also a high correlation between LHD and LHDR (r=0.85). All hips with subluxation were detected by US. In 11 hips that appeared normal on US, but with dysplasia or uncertain findings by radiography, the condition spontaneously normalized in 9 out of 9 examined hips with further follow-up. Conclusion: Because a reliable assessment of the hip is obtained, we recommend that US should be used as the primary imaging technique in the routine follow-up of children above 2 years of age with previous HD. Radiography should be omitted when US shows normal findings and is only needed when the US LHD is above the upper normal limit or the hip looks abnormal or suspicious by subjective evaluation.

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.

OBJECTIVE:To assess the effects of intra-articular injections of hyaluronan on symptoms of knee osteoarthritis (OA). METHODS:Two hundred and forty patients with symptomatic, radiological knee OA were randomly assigned to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were evaluated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (pain, function, motion, activity), algofunctional index, and global evaluation by patient and investigator. Analysis was by "intention to treat', "per protocol', and area under the curve principles on unstratified patient groups and for patients stratified into four groups of equal size by age and baseline algofunctional index. RESULTS:No serious side effects were reported. At 20 weeks both treatment groups were improved compared with baseline, with no difference between unstratified groups treated with placebo or hyaluronan. Comparison of treatment groups stratified by age and baseline algofunctional index revealed a significant difference in favour of hyaluronan over placebo (pain, activity, algofunctional index, global evaluations by patient and investigator) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference between the two treatments for the other three stratified subgroups of younger age or fewer symptoms. Similar results were obtained by area under the curve, intention to treat, and per protocol analysis. CONCLUSIONS:Patients older than 60 years with knee osteoarthritis and with significant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most likely to benefit from treatment with intra-articular hyaluronan injections.

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.

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.

In order to find the limits of normal variation of ultrasound measurements in children over 2 years of age, we examined 116 children and adolescents with normal hip joints. The children had been referred for various complaints from their lower extremities. Longitudinal ultrasound scanning from the lateral and anterior aspects was performed by the orthopedic surgeon as an integral part of the clinical examination. The most relevant parameters regarding hip dysplasia are those assessing the coverage of the femoral head: the lateral head distance (LHD, the distance from the lateral tangent of the bony epiphysis to the lateral bony acetabular rim) and the anterior head distance (AHD, measured as LHD, but from the anterior scan). The LHD increased with age; the upper normal limit (mean + 2 SD) increased from 4 mm at age 2-3 years to 7 mm at age 12-16 years. The AHD was larger in adolescents 12-16 years of age than in younger patients. The upper normal limit was 1 mm in the youngest and 2 mm in the oldest children. The mean (SD) differences (right minus left) in LHD and AHD were 0.3 (1.1) mm and 0.2 (1.0) mm, respectively. Radiographs were available in 15 of the patients and confirmed the ultrasound findings regarding femoral head coverage. Our findings should be of value in interpreting ultrasound measurements in older children.

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.

We compared the effectiveness of different approaches to hip screening in newborns. Three groups were studied: children born in our hospital from 1980 through 1985 who were clinically examined by pediatricians (group A), children born in 1986 and 1987 who were examined by ultrasound (US) in addition to clinical examination (group B), and children born in three district hospitals where neonatal clinical screening had not been performed by pediatricians (group C). There were significant differences between the three groups in the incidence of late-diagnosed hip dysplasia (HD): 2.6 in 1,000, 0.7 in 1,000, and 5.3 in 1,000, respectively. We conclude that US screening of hips in newborns was more effective than clinical screening alone and that clinical screening by pediatricians was superior to screening by doctors with less experience in examining children. US appears to have the potential to eradicate late-diagnosed dislocations, but milder degrees of HD still occur. With regard to the US method, measurement of femoral head coverage appears to be more adequate than subjective evaluation only.

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.

Summary: A review of reports on nonoperative treatment of acute, isolated anterior cruciate ligament (ACL) tears shows a large variability in results. This may be caused by variations in study designs. To our knowledge, no prospective study on isolated ACL tears diagnosed through arthroscopy has been published. We are reporting the short-term results of a prospective study of 29 nonoperatively treated acute ACL injuries. All patients had a history of trauma, with contact sports resulting in 20 of 29 injuries. The mean age was 25 years. The mean follow-up was 33 months. Of the 29 patients, 11 required ligament reconstruction in the follow-up period because of considerable instabilities. Only two patients kept their activity level. All but two patients had a positive pivot shift. The reconstructed group was younger than the nonoperated group, had a higher preinjury level of activity both in sports and daily life, and in general had a desire to stay at the preinjury level. The nonreconstructed group had a lower preinjury activity level and was willing to reduce their postinjury level. When suggesting nonoperative treatment to a young patient with an isolated ACL tear, the surgeon should emphasize the importance of abandoning contact sports and obtaining good muscle strength. A young patient in a knee-demanding profession or insisting on continuing knee-demanding sports should have an early reconstruction carried out.