True scaphoid fractures of the wrist are difficult to diagnose in children. In 5–40% of cases, a scaphoid fracture may not be detectable on initial X-ray, some fractures may take up to six weeks to become evident. Since missing a scaphoid fracture may have serious implications, many children with a suspected or “clinical” scaphoid fracture, but normal radiographs, may be over-treated. The purpose of this study was to identify predictors of true scaphoid fractures in children.

A retrospective cohort study was performed using electronic medical records for all patients over a two-year period presenting to a tertiary paediatric hospital with hand or wrist injury. Charts were identified by ICD-10 diagnostic codes and reviewed for pre-specified inclusion and exclusion criteria. Patients with either a clinical or true scaphoid fracture were included. When a scaphoid fracture was suspected, but imaging was negative for fracture, the diagnosis of a clinical scaphoid fracture was made. True scaphoid fractures were diagnosed when a fracture was evident on any modality of medical imaging (X-ray, CT, MRI) at any time post-injury.

Over the two-year study period, 148 patients (60 scaphoid fractures, 88 non-fractures) met inclusion and exclusion criteria for review. Mean (±SD) age was 13±2 years and 52% were male. The left wrist was injured in 61% of cases. Of the 60 true scaphoid fractures, mean age was 14±2 years, and 69% were male. Fracture location was primarily at the waist (48%) or distal pole (45%) of the scaphoid. Sports were the prevailing mechanism of injury. Six (11%) underwent surgery. Multivariate logistic regression demonstrated that older age, male gender, and right-sided injury were predictors of scaphoid fracture with odds ratios of 1.3 (95% CI: 1.1–1.6, p=0.005), 2.8 (95% CI: 1.3–6, p=0.007), and 2.4 (95% CI: 1.1–5.2, p=0.025).

Older age, male gender, and right-sided injury may be predictors of scaphoid fractures in children. Further evidence to support this may enable the formulation of clinical guidelines or rules to reduce the overtreatment of children presenting with a clinical scaphoid fracture.

The diagnosis of a clinical scaphoid fracture is made when a scaphoid fracture is suspected, but radiographs are normal. Standard treatment in this scenario involves immobilization and repeat x-rays in 10–14 days. When repeat x-rays are also normal but a scaphoid fracture is still suspected clinically, the optimal management in children is unknown. Our objective was to characterize these patients and evaluate their management and outcomes.

A retrospective study was performed of all patients presenting to a tertiary paediatric center over a two year period with a diagnosis of wrist or hand pain. Charts were identified by ICD-10 diagnostic codes and reviewed for inclusion and exclusion criteria. Patients were included if they had clinical suspicion of a scaphoid fracture but two sets of x-rays negative for fracture within 14 days of injury.

Ninety-one children (mean age 13.2 years, SD: 2.2) were identified with a clinical scaphoid fracture. Mean follow-up was 7.1 weeks. Most patients (60%) were injured either from a fall while ambulating or from sports. Sixteen (18%) patients received CT or MRI at an average of 8.4 weeks post-injury (95%CI:5–15.3). All patients were immobilized for a mean of 5.4 weeks. No patients underwent surgery. Five patients (5.5%) were found to have a scaphoid fracture diagnosed by X-ray or CT at a mean of 5.7 weeks post-injury (range 4.3–6.6). Other carpal fractures or ligamentous injuries were identified in three patients (3%) by MRI or CT. Seventy percent of patients healed within 6 weeks of injury.

The majority of children presenting with clinical suspicion of a scaphoid fracture but 2 sets of X-rays negative for fracture healed with immobilization. While the incidence of true scaphoid fracture may be low in children, MRI or CT may be warranted for patients where clinical suspicion persists.

Aims

The aim of this study was to evaluate the long-term inducible displacement of cemented tibial components ten years after total knee arthroplasty (TKA).

Summary

A promising approach to stimulate in vivo bone formation by using our newly developed magnesium-based bone substitutes, which can be an alternative to treat the patients with bone loss in addition to the anticatabolic drugs and growth factors.

Summary

Silver nanoparticles improve the tensile property of the repaired Achilles tendon by modulating the synthesis and deposition of collagen. This makes silver nanoparticles a potential drug for tendon healing process with less undesirable side effect.

Despite the myriad new spinal instrumentation systems, scoliosis can rarely be fully corrected, especially when the curves are stiff. A novel superelastic nickel-titanium (nitinol) rod that maximises the ability to slowly correct spinal deformities by utilising the viscoelastic properties of the spine has been developed. This parallel, double-blinded, randomised controlled trial compared the safety and efficacy of these new rods to conventional titanium rods in 23 patients with adolescent idiopathic scoliosis. The superelastic nitinol rods were found to be safe, could gradually correct scoliosis curves, and ultimately resulted in better coronal and sagittal alignments compared to traditional rods.

Despite the myriad new spinal instrumentation systems, scoliosis can rarely be fully corrected, especially when the curves are stiff. A novel superelastic nickel-titanium (nitinol) rod that maximises the ability to slowly correct spinal deformities by utilising the viscoelastic properties of the spine has been developed. This parallel, double-blinded, randomised controlled trial compared the safety and efficacy of these new rods to conventional titanium rods in 23 patients with adolescent idiopathic scoliosis. The superelastic nitinol rods were found to be safe, could gradually correct scoliosis curves, and ultimately resulted in better coronal and sagittal alignments compared to traditional rods.

Introduction

With the use of each pedicle screw for surgical correction of adolescent idiopathic scoliosis (AIS), there is an increase in instrumentation-related costs, operative time, risk of neural injury, and overall health-care expenses. As such, alternate level screw strategy (ALSS) has been reported as a potential alternative to contiguous multilevel screw strategy (CMSS). Moreover, studies have shown the importance in accounting for the flexibility of the curve based on the fulcrum bending radiograph when assessing postoperative curve correction. Therefore, this study addressed a radiographic and cost analysis comparing CMSS with ALSS for the treatment of thoracic AIS with titanium screws and rod application.

Unicompartment knee arthroplasty (UKA) was proven to be one of the standard treatments of medial compartment osteoarthritis. The key to success was restoration of pre-operative alignment. Overcorrection of coronal (AP) alignment may predispose to early osteoarthritis in the contralateral compartment, change in post-operative tibial slope may predispose to proximal tibial bone collapse and loosening of tibial prosthesis. Minimally invasive surgery (MIS) in UKA was developed quickly in the last ten years. However, MIS has limited access to visualize the surgical field and limb alignment. Computer navigation may help the surgeon to place the component in more accurate position. We aim to study the radiological alignment of computer assisted MIS UKA.

Eighteen patients with UKA (PreservationTM, all poly tibia, DePuy Orthopaedics Inc, Warsaw, IN) implanted using MIS technique were studied prospectively. The CiTM system (DePuy International Ltd, Warsaw IN) were used for computer navigation. Five male and 13 female patients were studied. The mean age of the patients was 58.2 (range, 45 to 70). All patients had medial compartment osteoarthritis with varus deformity. The postoperative coronal (AP) alignment and tibial slope of the operated limb were compared with the pre-operative alignment for any significant difference.

The mean pre-operative and post-operative radiographic coronal (AP) alignment of the operated limb were 8.4° varus (range, 2° to 12°) and 7.2° varus (range, 1° to 15°) respectively, the difference was not significant (p = 0.537). The mean pre-operative and post-operative tibial slope were 6.8° (range, 3° to 11°) and 5.8° (range, 3° to 10°) respectively, the difference was not significant (p = 0.066). The post-operative tibial slope correlated well with the intra-operative tibial slope recorded by computer after bone cut was made (Cronbach’s Alpha = 0.771). The mean tourniquet time was 124 minutes (range, 94 to 140 minutes).

There was no significant difference in pre-operative and post-operative coronal alignment of the operated limb. Computer assisted MIS UKA could reproduce the pre-operative coronal alignment and tibial slope. Restoration of the pre-operative limb alignment in coronal plane and tibial slope was crucial to the survival of UKA. Computer navigation could help the surgeon to position the component during minimally invasive surgery. However, the learning curve of computer assisted MIS UKA was steep.

Malalignment of more than three degrees in coronal plane was associated with poor outcome. Most of the alignment occurred in the tibial coronal plane alignment. Computer assisted surgery (CAS) in total knee arthroplasty (TKA) aimed to minimize malalignment. Most of the CAS-TKA results were using infrared tracking system. Electromagnetic navigation in total knee arthroplasty was developed in recent years. It aimed at high accuracy and easy signal detection. However, there was limited result being published.

From August, 2006 to March, 2008, 50 patients had TKA performed with Medtronic electromagnetic navigation (EM CAS-TKA). The results were compared with 50 matched patients who had TKA performed with conventional technique. The post-operative limb alignments were compared. More than three degrees deviation from neutral alignment was defined as outliers.

There was no significant difference in the age, sex distribution, pre-operative range of motion and pre-operative deformity between the two groups. EM-CAS TKA group had significantly less deviation from neutral in the tibial coronal plane (p < 0.001) and femoral sagittal plane (p = 0.006) plane than conventional group. There was no significant difference in femoral coronal plane and tibial sagittal plane alignment between the two groups (p = 0.069 and 0.185 respectively). There were significantly more outliers (> 3 malalignment) in tibial coronal plane (p = 0.004) and femoral sagittal plane (p = 0.049) in conventional group than EM-CAS TKA group. There was no significant difference in the outliers in femoral coronal plane, and tibial sagittal plane (p = 1 and 0.1 respectively). The mean tourniquet time of the EM-CAS TKA group, 95.7 minutes (range, 65 to 126 minutes), was significantly higher than the conventional group, mean 72.1 minutes (range, 45 to 120 minutes), p value < 0.001. There was no pin tract complication and infection in the electromagnetic navigation group.

Electromagnetic navigation had improved the tibial coronal plane and femoral sagittal plane alignment in total knee arthroplasty with less outlier. Better alignment may improve the survival of the prosthesis. The learning curve is short and it is easy to handle. Electromagnetic navigation has the potential application in minimally invasive total knee arthroplasty.

Idiopathic osteoarthritis (OA) is a complex, late-onset disease whose causes are still unknown. In spite of tremendous efforts, the search for the genes pre-disposing towards osteoarthritis has so far met with little success. We hypothesize that epigenetic changes play a major role in the pathology of OA. Epigenetics refers to stable, heritable, but potentially reversible modifications of gene expression that do not involve mutations in the DNA sequence, for example DNA methylation or histone modification. Epigenetic changes are gene and cell-type specific, may arise sporadically with increasing age or be provoked by environmental factors. To investigate whether epigenetic changes are significant factors in OA, we examined the DNA methylation status of the promoter regions of three genes that are expressed by OA, but not by normal, articular chondrocytes, namely MMP-3 (stromelysin-1), MMP-9 (gelatinase B) and MMP-13 (collagenase3). We hypothesized that these genes are silenced in normal chondrocytes by methylation of the cytosines of CpG dinucleotides in the respective promoter regions, but that abnormal expression is associated with a de-methylation, leading to eunsilencing f of gene expression. Cartilage was obtained from the femoral heads of 16 OA and 10 femoral neck fracture (#NOF) patients, which served as controls due to the inverse relationship between osteoporosis and OA. The cartilage was milled in a freezer mill with liquid nitrogen, DNA was extracted with a Qiagen kit, digested with methylation sensitive restriction enzymes, followed by PCR amplification. These enzymes will cut at their specific cleavage sites only if the CpGs is not methylated and thus allow us to determine methylation status of specific CpG sites.

Results. Less than 5% of the chondrocytes in superficial layer from #NOF cartilage expressed degradative enzymes, whereas all cloned chondrocytes from advanced-stage OA cartilage were immunopositive. The overall % of CpG demethylation in the promoters of control patients (whose chondrocytes did not express the enzymes) was 20.1%, whereas 48.6% of CpG sites were demethylated in degradative chondrocytes of OA patients (p< 0.001). For MMP-13, the increase in demethylation between control and OA was from 4 ^..20%; for MMP-9 from 47 ^..81% and for MMP-3 from 30 ^..57%. However, not all available CpG sites were equally demethylated. Some sites were uniformly methylated in both OA and controls, others were demethylated even in controls. However, there was at least one crucial site for each degradative enzyme, where the differences in the degree of methylation were greatest and statistically different. These sites were at −110 for MMP-13; −36 for MMP-9; −635 for MMP-3. There was no relation between the % demethylation and the patient fs age and no apparent difference between males and females.

Conclusions: We have demonstrated an association between abnormal gene expression of MMP-3, MMP-9 and MMP-13 and promoter DNA demethylation. This epigenetic dysregulation of genes appeared to be clonally inherited by daughter cells and may be typical for osteoarthritis and other complex, late-onset diseases.

Introduction: Anterior convex epiphysiodesis and posterior concave distraction has not been previously described in the literature for the treatment of thoracolumbar hemivertebrae. We describe our experience with long-term follow-up.

Method: Six consecutive patients with a mean age of 3.4 years were operated on with this technique. Levels of fusion extended two levels above and below the hemi-vertebra, while the instrumentation span the full length of the curve. Further concave distraction was carried out when there was evidence of loosening of the hooks.

Results: The average follow-up was 10.8 years (range 8 to 14). The mean Cobb angle before surgery was 49°, and at the latest follow-up was 26°. There was a mean 41% improvement in the scoliosis. In 5 of these cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction.

Conclusion: The addition of concave distraction provided better correction than convex epiphysiodesis alone. It is technically easier and safer than hemivertebra excision in the correction of such deformities. This method of treatment is recommended for patients with single fully segmented hemivertebrae located at the thoracolumbar junction that has a significant deformity.

Introduction: Anterior convex epiphysiodesis and posterior concave distraction has not been previously described in the literature for the treatment of thoracolumbar hemivertebrae. We describe our experience with long-term follow-up.

Methods: Six consecutive patients with a mean age of 3.4 years were operated on using this technique. The levels of fusion extended two levels above and below the hemivertebra, while the instrumentation spanned the full length of the curve. Further concave distraction was carried out when there was evidence of loosening of the hooks.

Results: The average follow-up was 10.8 years (range: eight to 14 years). The mean Cobb angle before surgery was 49 degrees, and at the latest follow-up was 26 degrees. There mean improvement in the scoliosis was 41%. In five of these cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction.

Conclusions: The addition of concave distraction provided better correction than convex epiphysiodesis alone. This method of treatment is recommended for patients with single fully segmented hemivertebrae located at the thoracolumbar junction associated with a significant deformity. This method is technically easier and safer than excision of the hemivertebra in the correction of such deformities.

The FBCI has been shown to be a better method for describing scoliosis correction because it takes spinal flexibility into consideration. 1

Objective: To use FBCI prospectively to compare the efficacy of four different posterior instrumentations in the correction of thoracic scoliosis.

Method: 123 idiopathic scoliosis patients with thoracic curves were surgically treated prospectively using 4 different posterior instrumentations: TSRH (n=35); ISOLA (n=33); CD-Horizon (CD-H: n=32); and Moss-Miami (MM: n=23). All the operations were performed by the same team of surgeons using standard techniques. The curve was measured using the Cobb’s method on the pre-operative PA standing, fulcrum bending and 1-week post-operative PA standing radiographs. The conventional correction rate and the FBCI were calculated. One-way ANOVA and independent sample t-test were used for statistical analysis.

Results: (1) There were no significant differences between any of the 4 instrumentations when assessed using the FBCI, however, the correction rate was better in CD-H than in ISOLA and TSRH (Table 1). (2) Higher FBCIs were observed in the stiff curve group (fulcrum flexibility £ 50%) compared with those in the flexible group (fulcrum flexibility > 50%), while the correction rates were lower in the former than in the latter (Table 2).

Discussion: Better correction rate obtained in the CD-H group was attributed to the more flexible curves rather than the instrumentation itself. In the flexible curve group, the instrumentations have been able to take up all the flexibility revealed by the fulcrum-bending radiograph. Although the correction rate was less in the stiff curve group, the FBCI showed that the deformity correction was actually more than that indicated by the fulcrum bending radiographs. One possible explanation of this phenomenon may be that the fulcrum-bending radiograph is less effective in eliciting all the flexibility in the stiff curves.

Conclusion: All 4 instrumentations were EQUALLY effective in correction of thoracic scoliosis when the curve flexibility was taken into consideration.

In scoliosis, it is well known that lateral deformity is coupled with vertebral axial rotation. Coupled motion in the sagittal plane, however, has not been investigated.

Objective: To investigate the behavior of the sagittal alignment changes when coronal deformity was corrected in idiopathic thoracic scoliosis.

Method: 36 idiopathic scoliosis patients with thoracic curves were examined before surgery. Coronal deformity was corrected using the Fulcrum Bending technique1, and biplane radiographs were taken to monitor the correction of the deformity, as well as the coupled sagittal alignment changes. Sagittal alignment was measured from T4/T5 to T12 using Cobb’s method. Difference of less or equal to 3 degrees between two measurements was treated as no change. Results were compared with those measured from standing lateral radiographs prior to and at 1 week after surgery (Posterior correction and fusion with ISOLA: n=15; CD-Horizon: n=8; Moss-Miami: n=11, USS: n=2). Pearson correlation was used for statistical analysis.

Results: (A) When scoliosis was corrected under fulcrum bending, the coupled changes in the thoracic kyphosis were decreased if it was greater than 20 degrees (n= 18), increased if less than 20 degrees (n= 2), and kept no change if it was around 20 degrees (n= 16). These changes were not related to the amount of deformity or flexibility in the coronal plane (Table I). (B) There was strong relationship between the sagittal alignment measured on the pre-operative fulcrum bending and postoperative lateral radiographs (P< 0.01). However, the final sagittal alignment was neither correlated with the magnitude or flexibility of the coronal deformity, nor the instrumentation applied (P> 0.05)

Discussion: A coupling exists between the coronal lateral deformity and the sagittal alignment in thoracic scoliosis. It seems that the sagittal alignment in a scoliotic spine tends to “normalize” with correction of the deformity: a “hyper-kyphotic” spine tends to reduce, and a “hypo-kyphotic” one tends to increase the kyphosis. Post-operative sagittal alignment seems to be decided by the coupling motion and the amount of curvature of the pre-bent rod, as neither the nature (degree or flexibility or curve pattern) of the coronal deformity nor the choice of instrumentation were related to the post-operative sagittal alignment.

Introduction: Collagen type X is secreted by hypertrophic chondrocytes during fracture repair. Its precise role is uncertain. This study uses a knockout mouse model in which the collagen X gene is removed to examine its function.

Method: Bilateral femoral fractures were created in type X collagen knockout mice (mutant) and normal mice (wild type), and were stabilized using an external fixator. The mice were sacrificed 7, 10, 14, 21, 28 and 60 days after fracture. Fracture healing was followed by x-rays, histology, gene expression studies, immuno-histochemistry and mechanical testing.

Results: In the mutant mice, bony union was delayed, there was abnormal persistence of aggrecan up to 60 days after fracture. Histology reviewed amorphous acellular areas surrounded by osteoclasts at 21 and 28 days, while mechanical testing revealed that at 14 days after fracture, mutant callus was stiffer than the wild type, but the trend is reversed at 28 and 60 days.

Discussion: This study contributes to the understanding of the basic mechanisms involved in fracture repair. The data suggest that collagen type X plays a significant role in bone remodeling during fracture healing. Its absence results in delayed union and abnormalities within the fracture callus.