Non-ossifying fibroma: natural history with an emphasis on a stage-related growth, fracture risk and the need for follow-up.

BACKGROUND: The aim of this study was to assess and present the radiological morphology of the non-ossifying fibroma (NOF), to describe the life span according to the Ritschl-stages in an effort to determine critical stages with regard to pathological fractures and discuss the need for a follow-up. METHODS: Reports of a consecutive series of 87 patients with 103 NOFs and a mean follow-up of 27 months were analysed according to the Ritschl-stages with regard to age at time of diagnosis, localisation, duration of stage and symptoms. RESULTS: Mean patient age in our series was 20 years and lesions most frequently affected the long bones of the lower extremity. Nineteen lesions were categorized in stage A, 53 in stage B, 17 in stage C and 14 in stage D. Most lesions were detected incidentally. In six of ten clinically symptomatic patients with an average age of ten years a pathological fracture occurred, and four of them were located in the tibia. All of these were in stage B with a mean length of 44 mm, an average expansion in relation to the bone-diameter of 75 % in transversal and 87 % in sagittal plane. Duration of the stages was variable. In the critical stage B the mean was 21 months. CONCLUSION: The non-ossifying fibroma follows a characteristic radiomorphological course with variable duration of each stage. Stage B lesions were found to be at an increased risk of fracture, and the age range over which fractures occur was wide. No fractures were detected in the other three stages. Follow-up, including clinical survey and imaging, at six to twelve month intervals may therefore be considered in the case of larger stage B lesions until stage C is reached.

Osteoarthritic changes rather than age predict outcome following arthroscopic treatment of femoroacetabular impingement in middle-aged patients.

BACKGROUND: Our purpose was to evaluate outcome following arthroscopic treatment of femoroacetabular impingement (FAI) in middle-aged patients and to define risk factors for conversion to total hip arthroplasty (THA). METHODS: This was a retrospective case series of 79 consecutive patients (40 to 65 years) undergoing arthroscopic treatment of FAI (follow-up ≥12 months). Outcome at follow-up was assessed using Hip outcome score (HOS). Alpha angle, Kellgren Lawrence grade (K-L grade), joint space width (JS), lateral center edge (LCE) angle, caput-collum-diaphysis (CCD) angle and acetabular index (AI) were analysed retrospectively. THA group and Non-THA group were compared. RESULTS: Seventy-nine patients (mean age 48.6 years, mean follow-up 32 months) were included. 18 patients (22.8 %) were converted to THA. Mean HOS score in the Non-THA group at time point of follow-up was 80.2. Non-THA group and THA group showed no significant differences for mean age (48.2 years vs. 49.9 years, p = 0.278), alpha angel (p = 0.541), LCE (p = 0.294), CCD (p = 0.101) and AI (p = 0.661) in contrast to differences for JS (p = <0.001) and K-L grade (p = <0.001). Risk of conversion to THA was higher for patients with K-L grade 3 (p = 0.003) or joint space less or equal 2 mm (p = 0.001). CONCLUSIONS: One fifth of the middle-aged patients required early conversion to THA. Advanced JS narrowing and K-L grade rather than age alone can be considered as risk factor for conversion to THA.

Emergency radiological examination of the externally stabilized pelvis--there is a catch to it: lessons learned from two cases with symphyseal disruption despite initial inconspicuous computed tomography.

BACKGROUND: Preclinical and early clinical external pelvic stabilization using commercially available devices has become common in trauma patient care. Thus, in the emergency department an increasing number of patients will undergo radiographic evaluation of the externally stabilized pelvis to exclude injuries. While reports exist where injuries to the pelvis were elusive to radiological examination due to the pelvic immobilization we elaborate on an algorithm to remove an external pelvic stabilizing device, prevent delayed diagnosis of pelvic disruption and thus increase patient safety. CASE PRESENTATION: We report on two patients with external pelvic stabilization presenting with an inconspicuous pubic symphysis on initial pelvic computed tomography scans. The first patient was an otherwise healthy 51-year old male being run over by his own car. He received external pelvic stabilization in the emergency department. The second patient was a 36-year old male falling from a ladder. In this patient external pelvic stabilization was performed at the scene. In the first patient no pelvic injury was obvious on computed tomography. In the second patient pelvic fractures were diagnosed, yet the presentation of the pubic symphysis appeared normal. Nevertheless, complete symphyseal disruption was diagnosed in both of them upon removal of the external pelvic stabilization and consequently required internal fixation. CONCLUSION: Based on our experience we propose an algorithm to "clear the initially immobilized pelvis" in an effort to minimize the risk of missing a serious pelvic injury and increase patient safety. This is of significant importance to orthopedic trauma surgeons and emergency physicians taking care of injured patients.

Identification of a blood-borne miRNA signature of synovial sarcoma.

BACKGROUND: Synovial sarcoma account for approximately 10 % of all soft-tissue tumors and occur most frequently in young adults. A specific translocation in this sarcoma induces fusion of the SYT gene on chromosome 18 to the SSX genes on chromosome X, leading to proliferation of the tumor cells. The need for non-invasive biomarkers indicating recurrence and activity of this disease has sparked research into short non-coding RNA known as microRNA (miRNA). METHODS: Blood samples of patients with active synovial sarcoma and of synovial sarcoma patients in complete remission as well as of healthy donors and patients with active leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma were collected. Whole blood RNA was extracted and samples of patients with active synovial sarcoma and of healthy donors were analyzed using an Affymetrix GeneChip miRNA Array v. 4.0. qRT-PCR was carried out to confirm a panel of miRNAs which where differentially expressed in the miRNA array. This miRNA-panel was further evaluated in patients with synovial sarcoma in complete remission and patients with active leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma as well as in an independent cohort of synovial sarcoma patients. RESULTS: Unsupervised hierarchical clustering of the miRNA arrays separated patients with active synovial sarcoma from healthy controls. A panel of seven miRNAs (miR-99a-5p, miR-146b-5p, miR-148b-3p, miR-195-5p, miR-223-3p, miR-500b-3p and miR-505-3p) was further validated by qRT-PCR to be significantly upregulated in synovial sarcoma patients. Moreover, most of the analyzed miRNAs were shown to be significantly upregulated in synovial sarcoma patients compared to leiomyosarcoma, MPNST, Ewing sarcoma and liposarcoma patients. Validation of the miRNA panel in an independent cohort of synovial sarcoma patients confirmed higher expression levels compared to healthy controls and patients in complete remission. CONCLUSION: Our results have identified a specific whole blood miRNA signature that may serve as an independent biomarker for the diagnosis of local recurrence or distant metastasis of synovial sarcoma. It even distinguishes synovial sarcoma from other sarcoma subtypes, thus potentially serving as a specific biomarker for synovial sarcoma.

Diagnosis of prosthetic joint infections using UMD-Universal Kit and the automated multiplex-PCR Unyvero i60 ITI(®) cartridge system: a pilot study.

BACKGROUND: Prosthetic joint infections (PJI) are associated with high morbidity and costs. Various efforts have been made to improve the diagnosis of PJI over the past years, but only few studies have assessed the diagnostic utility of nucleic acid amplification test (NAAT) techniques in this context. Here, we report our experience with a commercial 16S rRNA gene PCR and an automated multiplex-PCR cartridge system in identifying pathogens causing PJI. MATERIALS AND METHODS: A prospective single-centre study was performed including 54 patients with either septic or aseptic prosthetic joint replacement or surgical revision between February 2012 and April 2013. Conventional cultures of periprosthetic tissue samples were compared with the results of broad-range 16S rRNA gene real-time PCR (UMD-Universal Pathogen DNA Extraction and PCR Analysis, Molzym GmbH, Germany) and the multiplex-PCR Unyvero ITI(®) cartridge system (U-ITI; Curetis AG, Germany). Conventional culture and broad-range 16S rRNA gene real-time PCR were performed on all samples. U-ITI was used in a subgroup of 28 cases including all culture-positive cases. The agreement of the results from the methods was assessed. RESULTS: Of 54 cases, seven were culture-positive. Broad-range 16S rRNA gene real-time PCR gave 6, U-ITI 3 concordant positive results. Of the 47 culture-negative samples, 46 were also negative by broad-range 16S rRNA gene real-time PCR resulting in a 96 % (52/54) agreement between 16S rRNA gene PCR and culture. Of the 21 culture-negative samples analysed with U-ITI, 20 gave negative results, including the single 16S rRNA gene PCR-positive/culture-negative specimen. The rate of agreement between U-ITI and culture results was 82 % (23/28). CONCLUSION: This pilot study gave no indication of superiority of the used NAATs over conventional culture methods for the microbiological diagnosis of PJI. Drawbacks are susceptibility to contamination in the case of 16S rRNA gene real-time PCR, labour-intensive DNA extraction and limited pathogen panel in the case of the multiplex cartridge PCR system. More prospective trials are needed to evaluate the diagnostic performance of NAATs and their impact on the clinical management of PJI.

Periprosthetic joint infection--effect on quality of life.

PURPOSE: Relatively little is known about the extent to which periprosthetic joint infections (PJI) affect the patient's long-term quality of life (QoL). Our study aim was to assess the effect of a periprosthetic infection on our patients' QoL. METHODS: We collected data retrospectively of patients who had undergone surgery in our institution between 2006 and 2011. To capture their overall QoL, we telephoned the patients who could be reached and asked them the questions on the SF-12 questionnaire. RESULTS: In 84 patients (53 male, 31 female, 43 TKA and 41 THA), 88 % of the hip infections and 62 % of the knee infections had been successfully treated. The hip infections' cure rate was significantly higher than that of the knee joint infections. The average SF-12 score was 36.2 points on the physical scale and 52 on the mental scale. The difference in QoL between patients with and without successful infection therapy was not significant, nor did the site of the infection (knee or hip) influence QoL significantly. Comparison of our patients' QoL data to that from the general population revealed a significant difference in the physical scale but not the mental scale. CONCLUSION: From these results QoL is substantially reduced after a prosthetic infection. We did however observe that post-Girdelstone procedure patients or those with an arthrodesis attained an acceptable QoL, and that those methods remain therapeutic alternatives as far as patient-perceived QoL is concerned.

Vitamin E-enriched medium cross-linked polyethylene in total knee arthroplasty (VIKEP): clinical outcome, oxidation profile, and wear analysis in comparison to standard polyethylene-study protocol for a randomized controlled trial.

BACKGROUND: The gliding surface of total knee endoprostheses is exposed to high loads due to patient weight and activity. These implant components are typically manufactured from ultra-high molecular weight polyethylene (UHMWPE). Crosslinking of UHMWPE by ionizing radiation results in higher wear resistance but induces the formation of free radicals which impair mechanical properties after contact with oxygen. Medium-crosslinked UHMWPE enriched with vitamin E (MXE) provides a balance between the parameters for a sustainable gliding surface, i.e., mechanical strength, wear resistance, particle size, and oxidation stability. Therefore, a gliding surface for knee endoprostheses made up from this material was developed, certified, and launched. The aim of this study is to compare this new gliding surface to the established predecessor in a non-inferiority design. METHODS: This multicenter, binational randomized controlled trial will enroll patients with knee osteoarthritis eligible for knee arthroplasty with the index device. Patients will be treated with a knee endoprosthesis with either MXE or a standard gliding surface. Patients will be blinded regarding their treatment. After implantation of the devices, patients will be followed up for 10 years. Besides clinical and patient-related outcomes, radiological data will be collected. In case of revision, the gliding surface will be analyzed biomechanically and regarding the oxidative profile. DISCUSSION: The comparison between MXE and the standard gliding surface in this study will provide clinical data to confirm preceding biomechanical results in vivo. It is assumed that material-related differences will be identified, i.e., that the new material will be less sensitive to wear and creep. This may become obvious in biomechanical analyses of retrieved implants from revised patients and in radiologic analyses. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04618016. Registered 27 October 2020, https://clinicaltrials.gov/study/NCT04618016?term=vikep&checkSpell=false&rank=1 . All items from the World Health Organization Trial Registration Data Set can be found in Additional file 1.

Computer-assisted navigation for the intraoperative assessment of lower limb alignment in high tibial osteotomy can avoid outliers compared with the conventional technique.

PURPOSE: Longterm outcomes after valgization high tibial osteotomy (HTO) to treat varus osteoarthritis seem to depend mainly on correction precision. Intraoperative assessment of leg alignment based on radiological visualization of the mechanical axis is difficult and its precision is limited. A promising approach to improving precision is to make use of navigation systems. The case-control study reported here involved the evaluation of patients whose varus osteoarthritis had been treated by open-wedge high tibial ostoetomy, and an analysis of the effect of computer-guided navigation on postoperative leg alignment. METHODS: Forty patients with medial varus osteoarthritis managed by open-wedge high tibial osteotomy using a surgical navigation system were included in the present study (Group 1). They were compared with a retrospective control group (Group 2) of 40 patients with respect to postoperative leg alignment, correlation of planned and definitive correction, and postoperative deviation from the Fujisawa point. RESULTS: The mean values for planned and definitive correction showed no significant differences for identical demographic data. As a percentage of the width of the tibial plateau the postoperative weight-bearing radiographs showed a mechanical line that intersected with the knee base line at the desired value of 62% (Fujisawa point) in 58.8% (SD ± 6.1) in Group 1 and in 58.6% (SD ± 8.1) in Group 2. Despite similar mean values a significantly higher number of corrections were outside the reference area (n = 7) in the non-navigated group, whereby all corrections were within the desired range in the navigated group. There were no significant differences in operation time. CONCLUSIONS: This study showed that the use of a navigation system can not increase the precision of the open-wedge HTO procedure in patients with varus osteoarthritis but it can eliminate the outliers of a well defined range. LEVEL OF EVIDENCE: Case-control study, Retrospective comparative study, Level III.

Rotational limb alignment changes following total knee arthroplasty.

PURPOSE: The aim of the present study was to assess the changes in rotational alignment introduced by total knee arthroplasty (TKA) and the reproducibility of pre- and postoperative CT measurements of rotational limb alignment. METHODS: For this purpose we analyzed data from 196 consecutive cruciate-retaining, fixed bearing Columbus TKA procedures. Both pre- and postoperative scans torsion difference CT scans were available for measurements in 89 cases. Using these CT scans the neck-malleolar angle (NMA), the femoral posterior condylar angle (fPCA), the tibial posterior condylar axis (tPCA) and the tibial torsion angle (TTA) were independently assessed by three raters. CT scans were re-evaluated 8 weeks later by the most experienced rater for assessment of intraobserver agreement. RESULTS: Measurements of all angles were prone to high standard deviations reflecting interindividual variability. Mean fPCA changed from 1.3° to 2.7° internal rotation preoperatively to 0.1°-1.9° internal rotation postoperatively. Based on a relative external rotation of the tibial base plate as compared to the preoperative situation, we found a relative internal rotation of the postoperative NMA and tibial torsion of 3°-5.4° and 6°-7.5°, respectively. Intra- and interobserver agreement was strong for all angles assessed (ICCs 0.7-1.0) except for fPCA (ICC 0.2-0.6). However, mean absolute measurement differences for fPCA were clinically acceptable (1.2°-2.6°). CONCLUSIONS: Reproducibility of CT rotational limb alignment measurements was found to be clinically acceptable. Rotational alignment of the femoral and even more so of the tibial component will ultimately affect the rotational alignment of the entire limb-at least when fixed bearings are used. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Modular sleeves with ceramic heads in isolated acetabular cup revision in younger patients-laboratory and experimental analysis of suitability and clinical outcomes.

PURPOSE: One possibility in hip arthroplasty revisions is to combine a modular ceramic head with an adapter or sleeve in isolated acetabular cup replacement. This study consisted of an experimental part to analyse the reliability of taper damage predictions, and a clinical part to analyse the outcomes of modular ceramic head implantation in a case series of isolated cup replacements. METHODS: Analysis of scratch size on 11 explanted hip stems were examined macroscopically and by stereomicroscopy to classify damage to the conical taper. The second part consisted of a prospective analysis of isolated cup revisions using a modular ceramic head, performed in two orthopedic centres. RESULTS: Analysis of scratch size on the taper yielded inter-observer correlations of 0.545-0.909; comparison with stereomicroscopic data recordings yielded a moderate correlation, with values between 0.545 and 0.090. The clinical study included 47 isolated acetabular cup revisions involving modular ceramic heads. Ceramic head failure did not occur during the average clinical and radiological observation period of 26 months. Mean Harris Hip Score (HHS) at follow-up was 70 points. CONCLUSION: From these results, it can be concluded that damage to the implanted stem taper cannot be reliably predicted intraoperatively. Nevertheless, the clinical outcomes did show that there were no problems with the ceramic heads over the short observation period. The application of modular ceramic heads in younger patients requiring isolated cup replacement requires proper risk-benefit analysis, but is possible and appears to be a safe procedure.

Malposition and revision rates of different imaging modalities for percutaneous iliosacral screw fixation following pelvic fractures: a systematic review and meta-analysis.

INTRODUCTION: Percutaneous iliosacral screw placement following pelvic trauma is associated with high rates of revisions, screw malpositioning, the risk of neurological damage and inefficient stability. The correct entry point and the small target corridor may be difficult to visualize using only an image intensifier. Therefore, 2D and 3D image-based navigation and reconstruction techniques could be helpful tools. The aim of this systematic review and meta-analysis was to evaluate the best available evidence regarding the rate of malpositioning and revisions using different techniques for screw implantation, i.e., conventional, 2D and 3D image-based navigation and reconstruction techniques, CT navigation. METHODS: A systematic review and meta-analysis were performed using the data available on Ovid Medline. 430 studies published between 1/1948 and 2/2011 were identified by two independent investigators. Inclusion criteria were percutaneous iliosacral screw fixation after traumatic pelvic fractures with included revision rate or positioning of the screw, language of the article English or German. Exclusion criteria were osteoporotic fracture, tumor, reviews, epidemiological studies, biomechanical/cadaveric studies, studies about operative technique. For statistical analysis the random effect model was used. RESULTS: A total of 51 studies fulfilled the inclusion requirements describing 2,353 percutaneous screw implantations following pelvic trauma in 1,731 patients. The estimated rate of malposition was 0.1 % for 262 screws using CT navigation. This rate was significantly lower (p < 0.0001) than for the conventional technique with malposition rate of 2.6 % (total 1,832 screws). Using 2D and 3D image-based navigation and reconstruction techniques, the malposition rate was 1.3 % (total 445 screws). No significance was observed between the conventional and the 2D and 3D image-based navigation and reconstruction techniques. The rates of revision were not statistically significant with 2.7 % (1,832 implantations) in the conventional group, 1.3 % (445 implantations) in the group of 2D and 3D image-based navigation and reconstruction techniques and 0.8 % (262 implantations) using the CT navigation. CONCLUSIONS: CT navigation has the lowest rate of screw malposition, but on the other hand it could not be used for all type of fractures where surgical procedures (reduction maneuvers, additional osteosynthetic procedures) are necessary. The 2D and 3D image-based navigation and reconstruction techniques provide encouraging results with slightly lower rate of complications compared to the conventional technique and are additional tools to enhance the precision and decrease the rate of revision.

Paediatric acetabular fractures. Data from the German Pelvic Trauma Registry Initiative.

The aim of this study was to present an analysis of acetabular fractures during childhood as compared to those in adults. Within a multicenter register study, data of 3 time periods (1991-93, 1998-2000, 2004-2008) were pooled and analyzed for incidence, epidemiology, classification, outcome and treatment of acetabular fractures in children (< 15 years). One hundred fifty three children (2.1%) among 7360 patients with pelvic fractures were included in the study. Only 15 children sustained an acetabular fracture (9.8%). Simple fracture types according to Letournels' classification were more frequent in paediatric patients (p < 0.01), receiving less often operative treatment. Multiple injuries were present in 36% of children, the average Injury Severity Score (ISS) of all children was 17 points. Clinical results were good with an average Merle d'Aubigné score of 16.4 points and a Karnofsky performance of 90%. Fractures of the acetabulum in childhood remain a rare injury with distinct fracture characteristics, usually caused by high impact accidents.

Open-wedge osteotomy using an internal plate fixator in patients with medial-compartment gonarthritis and varus malalignment: 3-year results with regard to preoperative arthroscopic and radiographic findings.

PURPOSE: Our purpose was to evaluate the 3-year clinical results of patients with medial-compartment osteoarthritis of the knee and varus malalignment who underwent open-wedge high tibial osteotomy (HTO) with an internal plate fixator (TomoFix; Synthes, Solothurn, Switzerland). Clinical results are correlated with arthroscopic and radiographic findings at the time of surgery. METHODS: This study included 69 patients with a minimum follow-up of 36 months who underwent open-wedge HTO for medial-compartment osteoarthritis of the knee. Knee function was assessed before surgery and at 6, 12, 24, and 36 months after HTO by use of subjective International Knee Documentation Committee and Lysholm scores. Arthroscopic findings before HTO and radiographic assessment of the metaphyseal deformity of the proximal tibia (tibial bone varus angle) were correlated with clinical outcome. RESULTS: A significant continuous increase in International Knee Documentation Committee score from 47.25 ± 18.71 points before surgery to 72.72 ± 17.15 points at 36 months after HTO was found (P < .001). Grade of cartilage damage of the medial compartment and partial-thickness defects of the lateral compartment did not significantly influence clinical outcome (P > .05 at all time points). The tibial bone varus angle was correlated significantly with greater improvement and better clinical outcome after HTO (P < .01). The overall complication rate of 8.6% was mostly related to surgical causes; nevertheless, a high proportion of patients reported discomfort related to the implant at some point during the follow-up period (40.6%). CONCLUSIONS: Open-wedge osteotomy by use of the TomoFix system leads to reliable 3-year results. Results do not depend on the severity of medial cartilage defects, whereas partial-thickness defects of the lateral compartment seem to be well tolerated. The prognostic relevance of patellofemoral cartilage defects remains unclear. Local irritation of the implant was observed in a significant number of patients. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Correlation of radiographic and navigated measurements of TKA limb alignment: a matter of time?

Valid and reproducible measurements of limb alignment are prerequisites for planning, performing and evaluating TKAs. Although navigation systems have been shown to be reproducible tool for intraoperative TKA alignment measurements, particular doubt has been raised on the correlation with postoperative radiographic measurements. The aim of the present study was to evaluate whether the association of postoperative radiographic and navigation measurements of limb alignment was dependent on the time of acquisition. For this purpose, we retrospectively compared two groups of patients who underwent computer-assisted cemented TKA for osteoarthritis of the knee. Intraoperative navigation measurements (OrthoPilot™, Aesculap, Tuttlingen, Germany) were recorded before any cuts were made and again after implants had been placed. Long leg standing radiographs were acquired preoperatively in both the groups and either 2 weeks or 3 months postoperatively and AP limb alignment measurements were correlated with those of the respective navigation assessments. Preoperative deformity was similar in both the groups and correlation between radiographic and navigation measurements was excellent in both groups (ρ = 0.845 and 0.945, respectively). However, both mean and maximum discrepancies between radiographic and navigation measurements of leg alignment were significantly larger when radiographs were obtained 2 weeks (2.6° ± 2.1°, max. 10°) when compared with 3 months (1.8° ± 1.4°, max. 5°) postoperatively (P = 0.026). Accordingly, correlation between radiographic and navigation measurements was poor when radiographs were obtained 2 weeks postoperatively (ρ = 0.26, n.s.) but in the range of preoperative assessments when obtained 3 months postoperatively (ρ = 0.841, P < 0.001). Radiographic and navigation measurements of TKA limb alignment correlate well preoperatively. Equally good correlations can only be achieved when postoperative radiographic measurements are delayed to a time when more patients achieve full or near-full extension and are able to bear full weight leading to more valid radiographs.

Reliability of leg alignment using the OrthoPilot system depends on knee position: a cadaveric study.

Despite the increase in clinical use of navigation systems in total knee arthroplasty, few studies have focused on the reproducibility of these systems. The aim of the present study was to assess the influence of knee position and observer experience on intra- and inter-observer agreement in limb alignment assessment with the OrthoPilot system. Limb alignment in the coronal plane and extension range of the knee were assessed in four embalmed cadaveric specimens by five independent observers and measurements were repeated four times to determine intra- and inter-observer agreement, expressed as intraclass correlation coefficients (ICCs). Additionally, navigation results were compared against figures from conventional measurement of leg alignment (ground truth). Intra- and inter-observer agreements were excellent for assessing the extension range (ICC, 0.97 and 0.95) and the coronal femuro-tibial axis in knee extension (ICC, 0.92 and 0.88) but were generally worse in knee flexion (ICC, 0.62 and 0.55). There was an increased tendency of intraobserver errors in observers with less clinical experience. Mean correlation with conventional measurements was fair (Spearman's rho 0.61). The OrthoPilot system showed excellent reproducibility for assessment of extension range and coronal limb alignment. However, assessments of coronal limb alignment in flexion were prone to error and caution should be taken when relying on these measurements.

Mortality in patients with pelvic fractures: results from the German pelvic injury register.

BACKGROUND: Pelvic and acetabular fractures are rare injuries and account for approximately 3% to 8% of all fractures. Often the result of high energy blunt trauma, most of the patients sustaining pelvic injuries are at high risk of associated injuries strongly influencing outcome and survival rates. Because of anatomic differences it has been suggested that pediatric pelvic fractures are different injuries as compared with that of adults. However, this has been controversially discussed. Aim of this multicenter register study was to identify similarities and differences between pediatric and adult pelvic trauma and evaluate the influence of changes in medical treatment by comparison of two treatment periods. METHODS: In this multicenter register study, data of 4,291 patients treated from 1991 to 1993 (n = 1,723) or 1998 to 2000 (n = 2,568) for pelvic fractures in one of the 23 participating hospitals were evaluated for age, gender, Injury Severity Score (ISS), Hannover Polytrauma Score (PTS), fracture type (using Tile's classification), peripelvic soft tissue injury, need for emergency measures, mortality, cause of death, and need for operative stabilization. We compared the patients' characteristics of the two treatment periods and pediatric with adult pelvic injuries. Statistical analysis was performed using SAS software. RESULTS: There was no difference in terms of ISS, PTS, and presence of peripelvic soft tissue injuries between the two observation periods. Mortality rate dropped significantly from 7.9% to 5% (p < 0.0001) in the latter treatment period. Death was directly attributed to the pelvic injury in 11% from 1991 to 1993. This rate dropped significantly to 7% in the period from 1998 to 2000 (p = 0.020). A type fractures decreased from 61.1% (1991-1993) to 57.1% (1998-2000) of patients (p = 0.028) and except for these simple fractures there was a significant overall trend toward surgical treatment. Multivariate analysis revealed ISS, PTS, concomitant soft tissue injuries, and need for emergency measures as independent risk factors for death whereas surgical stabilization and treatment in the latter treatment period were associated with an increased survival rate. We found no difference between the adult and the pediatric group in terms of ISS and concomitant peripelvic soft tissue injuries. Children were less likely to receive surgical treatment (19.4% vs. 34.5%, p < 0.0001) but requirement for emergency measures was higher in the pediatric group (17.9% vs. 11.1%, p = 0.033). Moreover, we found no significant differences in mortality between both groups (6.1% vs. 8.2%, p = 0.28). Multivariate analysis showed age

Oblique Axis Body Fracture: An Unstable Subtype of Anderson Type III Odontoid Fractures-Apropos of Two Cases.

Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced Anderson type III fractures with a characteristic fracture pattern that we refer to as "oblique type axis body fracture." Results. The female patients aged 90 and 72 years, respectively, were both diagnosed with minimally displaced Anderson type III fractures. Both fractures had a characteristic "oblique type" fracture pattern. The first patient was treated conservatively with cervical spine immobilization in a semirigid collar. However, gross displacement was noted at the 6-week follow-up visit. The second patient was therefore treated operatively by C1-C3/4 posterior fusion and the course was uneventful. Conclusions. Oblique type axis body fractures resemble a highly unstable subtype of Anderson type III fractures with the potential of severe secondary deformity following conservative treatment, irrespective of initial grade of displacement. The authors therefore warrant a high index of suspicion for this injury and suggest early operative stabilization.

Effect of Rotational Component Alignment on Clinical Outcome 5 to 7 Years After TKA With the Columbus Knee System.

The aim of the study was to examine the effects of rotational component alignment on outcome after total knee arthroplasty (TKA) with a minimum follow-up of 5 years. For this study, 96 patients were available for follow-up at a mean of 5.7 years after TKA. Computed tomography scans were available in 55 patients. Outcome (Oxford Knee Score [KSS], Knee Injury and Osteoarthritis Outcome Score [KOOS], 36-item Short Form Health Survey) was correlated with postoperative femoral and tibial component malrotation or femorotibial rotational alignment mismatch. Results showed that femoral or tibial component malrotation or femorotibial mismatch were present in 15.5%, 38.2%, and 29.1% of patients, respectively. Although femoral componoent malrotation was associated with significantly poorer, KSS and KOOS scores, outcome was comparable for patients with or without tibial component malrotation or femorotibial mismatch. In conclusion, both internal and external rotational femoral malalignment exceeding 3° is associated with significantly poorer subjective and objective outcome 5 to 7 years after TKA. Tibial component malrotation and femorotibial mismatch were more common, but did not significantly compromise outcome. [Orthopedics. 2016; 39(3):S50-S55.].