What is the association between MRI and conventional radiography in measuring femoral head migration?

Background and purpose - Pelvic radiographs are traditionally used for assessing femoral head migration in residual acetabular dysplasia (RAD). Knowledge of the heightened importance of cartilaginous structures in this condition has led to increased use of MRI in assessing both osseous and cartilaginous structures of the pediatric hip. Therefore, we assessed the relationship between migration percentages (MP) found on MRI and conventional radiographs. Second, we analyzed the reliability of MP in MRI and radiographs.Patients and methods - We retrospectively identified 16 patients (mean age 5 years [2-8], 14 girls), examined for RAD during a period of 2½ years. 4 raters performed blinded repeated measurements of osseous migration percentage (MP) and cartilaginous migration percentage (CMP) in MRI and radiographs. Pelvic rotation and tilt indices were measured in radiographs. Bland-Altman (B-A) plots and intraclass correlation coefficients (ICC) were calculated for agreement and reliability.Results - B-A plots for MPR and MPMRI produced a mean difference of 6.4 with limits of agreement -11 to 24, with higher disagreements at low average MP values. Mean MPR differed from mean MPMRI (17% versus 23%, p < 0.001). MPR had the best interrater reliability with an ICC of 0.92 (0.86-0.96), compared with MPMRI and CMP with ICC values of 0.61 (0.45-0.70) and 0.52 (0.26-0.69), respectively. Intrarater reliability for MPR, MPMRI and CMP all had ICC values above 0.75 and did not differ statistically significantly. Differences inMPMRI and MPR showed no correlation to pelvic rotation index, pelvic tilt index, or interval between radiograph and MRI exams.Interpretation - Pelvic radiographs underestimated MP when compared with pelvic MRI. We propose CMP as a new imaging measurement, and conclude that it has good intrarater reliability but moderate interrater reliability. Measurement of MP in radiographs and MRI had mediocre to excellent reliability.

Pain, osteolysis, and periosteal reaction are associated with the STRYDE limb lengthening nail: a nationwide cross-sectional study.

Background and purpose - Observing serious adverse events during treatment with the Precice Stryde bone lengthening nail (NuVasive, San Diego, CA, USA), we conducted a nationwide cross-sectional study to report the prevalence of adverse events from all 30 bone segments in 27 patients treated in Denmark.Patients and methods - Radiographs of all bone segments were evaluated regarding radiographic changes in February 2021. We determined the number of bone segments with late onset of pain and/or radiographically confirmed osteolysis, periosteal reaction, or cortical hypertrophy in the junctional area of the nail.Results - In 30 bone segments of 27 patients we observed radiographic changes in 21/30 segments of 20/27 patients, i.e., 19/30 osteolysis, 12/30 periosteal reaction (most often multi-layered), and 12/30 cortical hypertrophy in the area of the junction between the telescoping nail parts. Late onset of pain was a prominent feature in 8 patients. This is likely to be a prodrome to the bony changes. Discoloration (potential corrosion) at the nail interface was observed in multiple removed nails. 15/30 nails were still at risk of developing complications, i.e., were not yet removed.Interpretation - All Stryde nails should be monitored at regular intervals until removal. Onset of pain at late stages of limb lengthening, i.e., consolidation of the regenerate, should warrant immediate radiographic examination regarding osteolysis, periosteal reaction, and cortical hypertrophy, which may be associated with discoloration (potential corrosion) of the nail. We recommend removal of Stryde implants as early as possible after consolidation of the regenerate.

Comparison of histomorphometric and radiographic effects of growth guidance with tension-band devices (eight-Plate and FlexTack) in a pig model.

Background and purpose - Temporary hemiepiphysiodesis for growth modulation in skeletally immature patients is a long-known technique. Recently the use of tension-band devices has become popular. This study compares 2 tension-band implants (eight-Plate and FlexTack) regarding their effects on the growth plate.Animals and methods - 12 pigs in 2 equally sized groups (A and B) were investigated. The right proximal medial tibia was treated with either eight-Plate or FlexTack. The left tibia of the same pig was treated with the opposite implant. After 9 weeks all implants were removed. Animals in group B were then hosted for another 5 weeks. Histomorphometric analysis of the growth plate was carried out after 9 and 14 weeks, respectively. Radiographs were taken at implantation, removal, and after 14 weeks.Results - Both tension-band devices achieved a statistically significant and clinically relevant growth inhibition, whereas the effect appeared to be more distinct after the use of FlexTack. Implant-related complications or physeal damage was not observed. After implant removal, rebound phenomenon was radiologically observed in all cases. The growth plates treated with eight-Plate showed a paradox reversal of the zonal distributions, with an increase of the proliferative zones at the previously arrested medial aspect of the physis and a decrease laterally.Interpretation - Both eight-Plate and FlexTack proved to be appropriate devices for growth-guiding treatment. The radiographic evaluation showed a change in angular axes after treatment with each implant, while the correction appeared to be faster with FlexTack. The paradox cartilaginous reaction observed after removal of the eight-Plate might be a histopathological correlate for rebound phenomenon.

Is casting of displaced paediatric distal forearm fractures non-inferior to reduction under general anaesthesia? Study protocol for a pragmatic, randomized, controlled non-inferiority multicentre trial (the casting trial).

BACKGROUND: Treatment of displaced distal forearm fractures in children has traditionally been closed reduction and pin fixation, although they might heal and remodel without surgery with no functional impairment. No randomized controlled trials have been published comparing the patient-reported functional outcome following non-surgical or surgical treatment of displaced paediatric distal forearm fractures. METHODS: A multicentre non-inferiority randomized controlled trial. Children aged 4-10 years with a displaced distal forearm fracture will be offered inclusion, if the on-duty orthopaedic surgeon finds indication for surgical intervention. They will be allocated equally to non-surgical treatment (intervention) or surgical treatment of surgeon's choice (comparator). Follow-up will be 4 weeks and 3, 6, and 12 months. The primary outcome is the between-group difference in 12 months QuickDASH score. We will need a sample of 40 patients to show a 15-point difference with 80% power. DISCUSSION: The results of this trial may change our understanding of the healing potential of paediatric distal forearm fractures. If non-inferiority of non-surgical treatment is shown, the results may contribute to a reduction in future surgeries on children, who in turn can be treated without the risks and psychological burdens associated with surgery. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (ID: NCT05736068). Date of registry: 17 February 2023.

Hemiepiphysiodesis: similar treatment time for tension-band plating and for stapling: a randomized clinical trial on guided growth for idiopathic genu valgum.

BACKGROUND: In children with angulating deformities of the lower limbs, hemiepiphysiodesis can be used to guide growth to achieve better alignment at skeletal maturity. Traditionally, this has been performed with staples. The tension-band plating technique is new and it has been advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling. The benefit of the tension-band plating technique has not yet been proven in experimental or randomized clinical studies. METHODS: We performed a randomized clinical trial in which 26 children with idiopathic genu valgum were allocated to stapling or tension-band plating hemiepiphysiodesis. Time to correction of the deformity was recorded and changes in angles on long standing radiographs were measured. Pain score using visual analog scale (VAS) was recorded for the first 72 h postoperatively. Analgesics taken were recorded by the parents. RESULTS: Mean treatment times for stapling hemiepiphysiodesis (n = 10) and for tension-band plating hemiepiphysiodesis (n = 10) were similar. Postoperative VAS scores and consumption of analgesics were also similar in both groups. No hardware failure or wound-related infection was observed. INTERPRETATION: Treatment time for the 2 treatment modalities was not significantly different in this randomized clinical trial. Tension-band plating and stapling appeared to have a similar effect regarding correction of genu valgum. We cannot rule out type-II error and the possibility that our study was underpowered. ClinicalTrials.gov Identifier: NCT01641354.

MRI May Be More Valuable than Pelvic Radiographs in the Assessment of Paediatric Borderline Acetabular Dysplasia.

The osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) is often used in diagnosing acetabular dysplasia (AD) in children. We examined the reliability of OAI and CAI in AD diagnostics and compared OAI measurements obtained from radiographs versus MRI. Four raters performed retrospective repeated measurements of the OAI and CAI on pelvic radiographs and MRI scans of 16 consecutive patients (mean age 5 years (2-8)) examined for borderline AD during a period of 2½ years. In MRI, the image selected for analysis by the raters was also registered. Spearman's correlation, scatter plots, and Bland-Altman (BA) plots were analysed for correlation between OAI on pelvic radiographs (OAIR) and MRI scans (OAIMRI), while intra- and interrater reliability was assessed for OAIR, OAIMRI, CAI, and MRI image selection using intraclass correlation coefficients (ICC). ICC values for inter- and intrarater reliability of OAIR, OAIMRI, and CAI were all above 0.65, with no significant differences observed. ICC values (CI) for individual raters' MRI image selection was 0.99 (0.998-0.999). The mean difference (95% CI) between OAIR and OAIMRI was -0.99 degrees (-1.84; -0.16), while the mean absolute difference (95% CI) between OAIR and OAIMRI was 3.68 degrees (3.17; 4.20). Absolute differences between OAIR and OAIMRI was independent of pelvic positioning or time interval between radiographs and MRI scans. OAI and CAI had high Intrarater reliability but mediocre interrater reliability. There was an absolute difference of 3.7 degrees in OAI between pelvic radiographs and MRI scans.

Guideline for management of septic arthritis in native joints (SANJO).

This clinical guideline is intended for use by orthopedic surgeons and physicians who care for patients with possible or documented septic arthritis of a native joint (SANJO). It includes evidence and opinion-based recommendations for the diagnosis and management of patients with SANJO.

[Paediatric femoral fractures].

Femoral fractures in children are not common injuries, and the treating physicians should master non-operative and operative treatment options. Non-accidental injury is frequently seen in children below two years of age. In this review, we describe a range of techniques for treatment of the injuries, and the current treatment trends and matters of discussion are early spica casting, age and weight guidance for use of flexible and rigid intramedullary nails. We advocate early consultation with a tertiary care centre for guidance and planning of the best treatment modality.

[Safe surgical dislocation of the hip to treatment of injuries after traumatic hip injury in children].

Traumatic dislocation of the hip in children is rare. Immediately closed reduction is important but contains a risk of tissue becoming intertwined in the joint space, and a risk of development of avascular femoral head necrosis. In this case report, we present two cases of traumatic hip luxation in an 11-year-old boy and a nine-year-old boy, where intertwined labral tears were recognised immediately following closed reduction in one case and after two weeks in the other. They were treated with safe surgical dislocation of the femoral head. Blood flow to the femoral head was ensured by perioperative monitoring, and both boys had complete recovery.

Comparison of Temporary Epiphysiodesis With RigidTacks™ and Blount-Staples in a Porcine Animal Model Using Magnetic Resonance Imaging.

RigidTack™ is a newly developed implant for total temporary epiphyseodesis. The implant combines the technical advantages of the traditionally used rigid Blount-staples and the newer flexible eight-plates™. Thus, the implant is rigid like the Blount-staples, which may be a biomechanical advantage in temporary epiphyseodesis, and has an easy and guided implantation technique like the eight-plate™. As in eight-plates™, supposedly only two RigidTacks™ are sufficient for temporary epiphyseodesis compared to six Blount-staples in traditional treatment. The goal of this study was to compare Blount-staples and RigidTacks™ in regard to the total potential of growth arrest, the occurrence of postoperative implant-associated complications, secondary angular deformities, and central joint deformations. Twelve pigs were allocated in two groups (n = 6) for treatment of the proximal tibia. Total temporary epiphysiodesis was performed with either four Blount-staples or two RigidTacks™. Magnetic resonance imaging (MRI)-scans were performed before and 14 weeks after surgery, and the amount and distribution of growth arrest were evaluated by measuring the interphyseal distance in nine defined zones. Total temporary epiphysiodesis with two RigidTacks™ resulted in a similar amount of growth arrest as that of four Blount-staples. No significant coronal or sagittal angular deformities or joint deformities were observed in either group; however, one secondary loosening of a Blount-staple occurred. The study concluded that Blount-staples and RigidTacks™ are adequate implants for total temporary epiphysiodesis. Whether or not the precise implant-placement through the guided implantation technique of RigidTacks™ and a reduced number of implants indeed lead to a reduction of secondary angular deformities has to be investigated in further clinical trials. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:946-953, 2020.

Correlation of radiological and clinical measurement of genu valgum in children.

INTRODUCTION: Genu valgus is a condition characterised by a lateral shift of the knee's mechanical axis. The deformity can be characterised using clinical examinations and long hip-knee-ankle (HKA) angles, but it is unclear how these investigations correlate with each other. Our aim was to examine the correlation between clinical and radiographic measurements of the lower extremities in children. METHODS: A total of 49 children between 5.9 and 16.7 years of age who had been referred with genu valgum deformity were included. They all had their intermalleolar (IM) distance measured and a standardised anterior-posterior radiograph of the lower extremities taken. IM distance was adjusted for the mean tibial and femoral length to adjust for differences in leg length. We calculated the Spearman's rank correlation coefficient to study the reliability between radiographs and clinical examinations. RESULTS: We found no correlation between clinical IM distance and the HKA angles. Spearman's rho for comparison between adjusted clinical IM distance measurements and HKA angles on radiographs was found to be 0.36. CONCLUSIONS: We found a poor correlation between clinical examinations and HKA angles as data were corrected for leg length. More studies are needed to provide clear recommendations for following children with malalignment. FUNDING: none. TRIAL REGISTRATION: The study was registered with the Danish Data Protection Agency.

Guided growth: mechanism and reversibility of modulation.

In paediatric orthopaedics, deformities and discrepancies in length of bones are key problems that commonly need to be addressed in daily practice. An understanding of the physiology behind developing bones is crucial for planning treatment. Modulation of the growing bone can be performed in a number of ways. Here, we discuss the principles and mechanisms behind the techniques. Historically, the first procedures were destructive in their mechanism but reversible techniques were later developed with stapling of the growth plate being the gold standard treatment for decades. It has historically been used for both angular deformities and control of overall bone length. Today, tension band plating has partially overtaken stapling but this technique also carries a risk of complications. The diverging screws in these implants are probably mainly useful for hemiepiphysiodesis. We also discuss new minimally invasive techniques that may become important in future clinical practice.

Similar growth plate morphology in stapling and tension band plating hemiepiphysiodesis: a porcine experimental histomorphometric study.

The tension band plating technique for hemiepiphysiodesis is new and advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling. The benefit of the tension band plating technique has not yet been proven in experimental or randomized clinical studies. Ten weeks old domestic pigs in two randomized, paired studies were used. Right proximal tibia was randomized to medial epiphysiodesis by either stapling or tension band plating. Left side received the opposite treatment. Study A (n = 10): 9 weeks treatment. Study B (n = 8): implant removal after 9 weeks of treatment and 5 weeks of housing. Fractions of the chondrocyte layers were determined using quantitative histomorphometry. Mean heights of the growth plates were measured. No significant changes were observed between histomorphometric parameters in neither study A or B. Areas with disorganized cartilage tissue were abundant in 13/16 samples from study B and observed after both treatment with tension band plating and staples. Chondrocyte zone fractions did not differ between tension band plating and staple treatment in this randomized, paired animal study. The growth plate responded to release of hemiepiphysiodesis with abundant disorganized cartilage tissue in both groups. The histological response to hemiepiphysiodesis by tension band plating and staples appear to be similar.

Superior 11-year survival but higher polyethylene wear of hydroxyapatite-coated Mallory-Head cups.

Hydroxyapatite (HA) coating of implant surfaces is believed to improve longevity of uncemented total hip arthroplasty (THA). However; it is speculated that HA particles may cause third body wear of the polyethylene (PE) liner with subsequent osteolysis and aseptic loosening of implants. We performed a retrospective comparison of two patient populations with cementless Mallory-Head acetabular components. The patients were identified in the Danish hip arthroplasty Registry (DHR); 77 patients had HA-coated cups and 73 patients had non-HA coated cups. Anteroposterior (AP) radiographs were analysed for PE wear, osteolysis was quantified and survival of the acetabular components was compared. The mean follow-up was 11 years. There were no cup revisions in the HA group and 7 cup revisions in the non-HA group (P<0.01). The reason for revision in all cases was aseptic loosening of both stem and cup. The amount of osteolysis was significantly increased around cups in the non-HA group. The two-dimensional linear PE wear-rate of 0.18 mm/year was higher (P<0.001) in the group with HA coated cups compared with 0.12 mm/year in the group with non-HA coated cups. The mean age was lower (P=0.001) in the HA group (57 years) compared with the non-HA group (63 years). After 11.1 years of follow-up non-HA coated cups had a higher revision rate. Increased PE wear with HA-coated cups did not have a negative influence on the revision rate, but may result in a need for revision surgery over time.