Vitamin C as a Potential Prophylactic Measure Against Frozen Shoulder in an In Vivo Shoulder Contracture Animal Model.

BACKGROUND: Frozen shoulder is a common, painful, and movement-restricting condition. Although primary frozen shoulder is idiopathic, secondary frozen shoulder can occur after trauma or surgery. Prophylactic and therapeutic options are often unsatisfactory. Vitamin C (ascorbic acid) is a potent physiological antioxidant and likely inhibits the activation of nuclear factor κB, which plays a decisive role in inflammatory reactions. HYPOTHESIS: Because of its anti-inflammatory effects, vitamin C may be valuable in the prevention of secondary frozen shoulder. STUDY DESIGN: Controlled laboratory study. METHODS: An in vivo shoulder contracture model was conducted by fixation of the right proximal limb of Sprague-Dawley rats. A treatment group (n = 8) receiving vitamin C orally was compared with a control group (n = 9) without vitamin C. The primary outcome was capsular thickness at the shoulder joint measured on magnetic resonance imaging (MRI) examination. Further histological examination was performed but was not statistically analyzed because of variability of the cutting plane through the glenoid. RESULTS: Vitamin C treatment resulted in less thickening of the axillary fold of the operated shoulder at 2 of the 3 locations measured on MRI compared with untreated controls (insertion to the glenoid, P = .074; insertion to the humerus, P = .006; middle of the axillary recess, P = .008). The observed structural changes in histological examination corroborated the significant changes obtained from the MRI measurements. CONCLUSION: Prophylactic vitamin C seemed to reduce the thickening of the axillary recess in secondary frozen shoulder in this preclinical study. CLINICAL RELEVANCE: Vitamin C may be helpful as a noninvasive therapeutic measure to prevent secondary frozen shoulder (eg, within the context of surgery in the shoulder region or immobilization) or to treat primary frozen shoulder at an early stage. Further studies are required to evaluate the effect of this treatment in humans and the necessary dosage in humans.

Platelet-rich plasma as a potential prophylactic measure against frozen shoulder in an in vivo shoulder contracture model.

INTRODUCTION: Frozen shoulder (adhesive capsulitis) is a common painful and functionally-limiting disease affecting around 2% of the population. So far, therapeutic options are limited and often unsatisfactory. Platelet-rich plasma (PRP) has been used as a treatment option in other orthopedic diseases since it contains growth factors that stimulate tissue repair. So far, the effect of PRP on frozen shoulder lacks evidence. We hypothesized that PRP may be valuable in the prophylaxis and treatment of secondary frozen shoulder due to capsular remodeling. MATERIALS AND METHODS: An experimental study of an in vivo frozen shoulder model was conducted. Twenty Sprague-Dawley rats underwent surgery in which the body of the scapula was connected to the humerus with a high-strength suture. Two groups of 8 weeks survival time were allocated; a treatment group with one intraoperative injection of PRP into the glenohumeral joint (n = 10) and a control group without PRP (n = 10). The primary outcome was the structural change in the posterior synovial membrane of the posterior and inferior part of the glenohumeral joint using a semi-quantitative grading from 0 (lowest) to 3 (highest). RESULTS: The posterior synovial membrane structural changes were significantly lower in the PRP group (median = 1 [interquartile range (IQR) = 0-1]) compared to controls (median = 2 [IQR = 1-3]) (p = 0.028). There were no differences for the remaining synovial membrane changes and fibrous capsule responses between groups. CONCLUSIONS: In this in vivo shoulder contracture model, PRP injections seem to reduce the histological severity grade of some parts (i.e., posterior synovial membrane changes) of the secondary frozen shoulder without causing any side effects. It may be considered to investigate this effect further in future studies as a potential prophylaxis of secondary frozen shoulder (e.g., in operated or immobilized shoulders) or as a treatment option for patients with frozen shoulder in the early stage.

Are the rib fracture score and different computed tomography measures of obesity predictors for mortality in patients with rib fractures? A retrospective cohort study.

BACKGROUND: There is missing knowledge about the association of obesity and mortality in patients with rib fractures. Since the global measure of obesity (body mass index [BMI]) is often unknown in trauma patients, it would be convenient to use local computed tomography (CT)-based measures (e.g., umbilical outer abdominal fat) as a surrogate. The purpose of this study was to assess (1) whether local measures of obesity and rib fractures are associated with mortality and abdominal injuries and to evaluate (2) the correlation between local and global measures of obesity. MATERIALS AND METHODS: A retrospective cohort study included all inpatients with rib fractures in 2013. The main exposure variable was the rib fracture score (RFS) (number of rib fractures, uni- or bilateral, age). Other exposure variables were CT-based measures of obesity and BMI. The primary outcome (endpoint) was in-hospital mortality. The secondary outcome consisted of abdominal injuries. Sex and comorbidities were adjusted for with logistic regression. RESULTS: Two hundred and fifty-nine patients (median age 55.0 [IQR 44.0-72.0] years) were analyzed. Mortality was 8.5%. RFS > 4 was associated with 490% increased mortality (ORadjusted = 5.9, 95% CI 1.9-16.6, p = 0.002). CT-based measures and BMI were not associated with mortality, rib fractures or injury of the liver. CT-based measures of obesity showed moderate correlations with BMI (e.g., umbilical outer abdominal fat: r = 0.59, p < 0.001). CONCLUSIONS: RFS > 4 was an independent risk factors for increased mortality. Local and global measures of obesity were not associated with mortality, rib fractures or liver injuries. If the BMI is not available in trauma patients, CT-based measures of obesity may be considered as a surrogate.

Diurnal T2-changes of the intervertebral discs of the entire spine and the influence of weightlifting.

The purpose was to study if (1) diurnal changes occur in the entire spine and if (2) intervertebral discs (IVDs) of weightlifters (WL) have decreased baseline T2-values in the morning as well as (3) increased diurnal changes throughout the day. This prospective cohort study investigated healthy volunteers between 2015 and 2017. WL were required to have participated in weightlifting ≥ 4×/week for ≥ 5 years, while non-weightlifters (NWL) were limited to < 2×/week for ≥ 5 years. Both groups underwent magnetic resonance imaging (MRI) of the entire spine in the morning and evening. WL were requested to perform weightlifting in-between imaging. IVD regions of interest (nucleus pulposus) were defined and T2-maps were measured. Analysis consisted of unpaired t-test, paired t-test, propensity-score matching (adjusting for age and sex), and Pearson correlation. Twenty-five individuals (15 [60.0%] males) with a mean age of 29.6 (standard deviation [SD 6.9]) years were analyzed. Both groups (WL: n = 12 versus [vs.] NWL: n = 13) did not differ demographic characteristics. Mean IVD T2-values of all participants significantly decreased throughout the day (95.7 [SD 15.7] vs. 86.4 [SD 13.9] milliseconds [ms]) in IVDs of the cervical (71.8 [SD 13.4] vs. 64.4 [SD 14.1] ms), thoracic (98.8 [SD 19.9] vs. 88.6 [SD 16.3] ms), and lumbar (117.0 [SD 23.7] vs. 107.5 [SD 21.6] ms) spine (P < 0.001 each). There were no differences between both groups in the morning (P = 0.635) and throughout the day (P = 0.681), even after adjusting for confounders. It can be concluded that diurnal changes of the IVDs occurred in the entire (including cervical and thoracic) spine. WL and NWL showed similar morning baseline T2-values and diurnal changes. Weightlifting may not negatively affect IVDs chronically or acutely.

Comparison of intraoperative 2D vs. 3D imaging in open reduction and fixation of distal radius fractures.

PURPOSE: In the volar plating of distal radius fractures, intraoperative three-dimensional (3D) imaging is designed to allow better judgment regarding screw and implant positioning compared with conventional intraoperative two-dimensional (2D) imaging. We evaluated the impact of these two imaging modalities on the rates of intraoperative revision and secondary surgery, as well as the need for implant removal during follow-up. METHODS: A retrospective analysis of consecutive patients who underwent volar plate osteosynthesis for isolated distal radius fractures between January 2008 and April 2016 was performed. Patient files were evaluated for intraoperative imaging findings, intraoperative and postoperative revision rates, and implant removal during follow-up. Additional analyses of radiation exposure, operation time, and hospitalization time were performed. RESULTS: A total of 314 patients were analyzed (mean age: 54 ± 19 years; 210 females). For 246 patients, only 2D imaging was performed, while the remaining 68 patients underwent both 2D and 3D imaging (O-Arm, Medtronic). The intraoperative revision rate was significantly (p < 0.001) higher with 3D imaging (32.4%) compared with 2D imaging (2.0%). The postoperative revision rates were similar between both the groups (2.9% vs. 2.0%; p = 0.674). Compared with 2D imaging, the use of the Medtronic O-Arm resulted in a significantly lower implant removal rate (8.8% vs. 18.7%; p = 0.036) during follow-up. CONCLUSION: Compared with conventional 2D imaging, the use of intraoperative 3D imaging significantly increased the intraoperative revision rate and has the potential for positive long-term effects for lowering the risk of requiring an implant removal.

Implementation of new standard operating procedures for geriatric trauma patients with multiple injuries: a single level I trauma centre study.

BACKGROUND: The demographic changes towards ageing of the populations in developed countries impose a challenge to trauma centres, as geriatric trauma patients require specific diagnostic and therapeutic procedures. This study investigated whether the integration of new standard operating procedures (SOPs) for the resuscitation room (ER) has an impact on the clinical course in geriatric patients. The new SOPs were designed for severely injured adult trauma patients, based on the Advanced Trauma Life Support (ATLS) and imply early whole-body computed tomography (CT), damage control surgery, and the use of goal-directed coagulation management. METHODS: Single-centre cohort study. We included all patients ≥65 years of age with an Injury Severity Score (ISS) ≥ 9 who were admitted to our hospital primarily via ER. A historic cohort was compared to a cohort after the implementation of the new SOPs. RESULTS: We enrolled 311 patients who met the inclusion criteria between 2000 and 2006 (group PreSOP) and 2010-2012 (group SOP). There was a significant reduction in the mortality rate after the implementation of the new SOPs (P = .001). This benefit was seen only for severely injured patients (ISS ≥ 16), but not for moderately injured patients (ISS 9-15). There were no differences with regard to infection rates or rate of palliative care. CONCLUSIONS: We found an association between implementation of new ER SOPs, and a lower mortality rate in severely injured geriatric trauma patients, whereas moderately injured patients did not obtain the same benefit. TRIAL REGISTRATION: Clinicaltrials.gov NCT03319381, retrospectively registered 24 October 2017.

Feasibility of iliosacral screw placement in patients with upper sacral dysplasia.

BACKGROUND: Exact knowledge of the sacral anatomy is crucial for the percutaneous insertion of iliosacral screws. However, dysplastic anatomical patterns are common. In addition to a preoperative computed tomography (CT) analysis, conventional radiographic measures may help to identify upper sacral dysplasia and to avoid damage to surrounding structures. Aiming to further increase safety in percutaneous iliosacral screw placement in the presence of sacral dysmorphism, this study examined the prevalence of previously established radiographic signs and, in addition, defined the "critical SI angle" as a new radiographic criterion. METHODS: Pelvic CT scans of 98 consecutive trauma patients were analysed. Next to assessment of established signs indicating upper sacral dysplasia, the critical sacroiliac (SI) angle was defined in standardized pelvic outlet views. RESULTS: The critical SI angle significantly correlates with the presence of mammillary bodies and an intraarticular vacuum phenomenon. With a cut-off value of - 14.2°, the critical SI angle detects the feasibility of a safe iliosacral screw insertion in pelvic outlet views with a sensitivity of 85.9% and a specificity of 85.7%. CONCLUSIONS: The critical SI angle can support the decision-making when planning iliosacral screw fixation. The clinical value of the established signs of upper sacral dysplasia remains uncertain.

Early Operative Versus Nonoperative Treatment of Fragility Fractures of the Pelvis: A Propensity-Matched Multicenter Study.

OBJECTIVE: To compare early operative treatment with nonoperative treatment of fragility fractures of the pelvis regarding mortality and functional outcome. DESIGN: Retrospective. SETTING: Two trauma centers. PATIENTS AND METHODS: Two hundred thirty consecutive patients 60 years of age or older with an isolated low-energy fracture of the pelvis and with a follow-up of at least 24 months. In center 1, treatment consisted of a nonoperative attempt and early operative fixation if mobilization was not possible. In center 2, all patients were treated nonoperatively. MAIN OUTCOME MEASUREMENTS: Primary outcome was mortality. Secondary outcomes were in-hospital complications. Patients who survived were contacted by phone, and a modified Majeed score was obtained to assess functional outcome at the final follow-up. RESULTS: At the final follow-up (mean 61 months, SD 24), 105/230 (45.7%) patients had died. One year after the initial hospitalization, 34/148 patients [23%, 95% confidence interval (CI): 17%-31%] of the early operative group and 14/82 patients (17%, 95% CI: 10%-27%) of the nonoperative group had died (P = 0.294). Nonoperative treatment had a protective effect on survival during the first 2 years (hazard ratio of the nonlinear effect: 2.86, 95% CI: 1.38-5.94, P < 0.001). Patients in the early operative treatment group who survived the first 2 years had a better long-term survival. The functional outcome at the end of follow-up as measured by a modified Majeed score was not different between the 2 groups (early operative: 66.1, SD 12.6 vs. nonoperative: 65.7, SD 12.5, P = 0.910). CONCLUSION: Early operative fixation of patients who cannot be mobilized within 3-5 days was associated with a higher mortality rate and complication rate at 1 year but with a better long-term survival after more than 2 years. Hence, patients with a life expectancy of less than 2 years may not benefit from surgery with regard to survival. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Rate of intraoperative problems during sacroiliac screw removal: expect the unexpected.

BACKGROUND: The indications for sacroiliac screw (SI) removal have been under debate. Data on complication rates of SI screw removal is missing in the current literature. The objective of this study was to compare the rate of intra- and perioperative problems and complications during SI screw removal to those with SI screw fixation. METHODS: A retrospective observational study with two interventions in the same cohort was performed. Consecutive patients who underwent both sacroiliac screw fixation for an isolated fracture of the pelvic ring and removal of the same implants between November 2008 and September 2015 (n = 19; age 57.3, SD 16.1 years) were included. Intraoperative technical problems, postoperative complications, duration of surgery, and radiation dose were analysed. RESULTS: Intraoperative technical problems occurred in 1/19 patients (5%) during SI screw fixation and in 7/19 cases (37%) during SI screw removal (p = .021). Postoperative complications were seen in 3/19 patients after SI screw fixation and in 1/19 patients after SI screw removal (p = 0.128). The surgical time needed per screw was longer for screw removal than for implantation (p = .005). The amount of radiation used for the whole intervention (p = .845) and per screw (p = .845) did not differ among the two interventions. CONCLUSIONS: Intraoperative technical problems were more frequent with SI screw removal than with SI screw fixation. Most of the intraoperative technical problems in this study were implant-related. They resulted in more surgical time needed per screw removed but similar radiation time.

Correlation of radiographic variables to guide safe implant positioning during acetabular surgery and hip replacement: a retrospective observational study.

BACKGROUND: Knowledge of periacetabular anatomy is crucial for prosthetic cup placement in total hip arthroplasty and for screw placement in anterior fixation with acetabular fractures. It is known that degree of hip dysplasia correlates with medial bone stock and that medial bone stock shows a weak correlation to Lequesne's acetabular index (AI). Aim of this study was to investigate a possible correlation between AI and the newly proposed medial safe zone. METHODS: AI and the medial save zone were measured on 419 hips using a computed-tomography scan of the pelvis. AI was assessed on a 2D reconstructed anterior-posterior view of the pelvis using VOXAR™. Correlation was measured using the Pearson correlation coefficient. RESULTS: Mean AI was 4.2 degrees (SD 4.9 degrees). Mean medial safe zone was 8.1 mm (SD 1.9 mm). There was a significant correlation between AI and medial save space with a Pearson correlation coefficient r = 0.33 (p = .001). CONCLUSION: There is a weak correlation between AI and medial safe zone. AI should not be used to predict medial safe zone. Due to the weakness in correlation AI is not suited for predicting medial safe zone. However, a low or negative AI can be a warning sign for less medial safe zone, prompting surgeons to take care when reaming in THA or placing periacetabular screws.

Standards for external fixation application: national survey under the auspices of the German Trauma Society.

INTRODUCTION: External fixation is widely accepted as a provisional or sometimes definitive treatment for long-bone fractures. Indications include but are not limited to damage control surgery in poly-traumatized patients as well as provisional bridging to definite treatment with soft tissue at risk. As little is known about surgeon's habits in applying this treatment strategy, we performed a national survey. METHODS: We utilized the member database of the German Trauma Society (DGU). The questionnaire encompassed 15 questions that addresses topics including participants' position, experience, workplace, and questions regarding specifics of external fixation application in different anatomical regions. Furthermore, we compared differences between trauma centre levels and surgeon-related factors. RESULTS: The participants predominantly worked in level 1 trauma centres (42.7%) and were employed as attendings (54.7%). There was widespread consensus for planning and intra-operative radiographical control of external fixation. Surgeons appointed at a level I trauma centre preferred significantly more often supra-acetabular pin placement in external fixation of the pelvis rather than the utilization of iliac pins (75.8%, p = 0.0001). Moreover, they were more likely to favor a mini-open approach to insert humeral pins (42.4%, p = 0.003). Overall, blunt dissection and mini-open approaches seemed equally popular (38.2 and 34.1%). Department chairmen indicated more often than their colleagues to follow written pin-care protocols for minimization of infection (16.7%, p = 0.003). CONCLUSION: Despite the fact that external fixation usage is widespread and well established among trauma surgeons in Germany, there are substantial differences in the method of application.

Sacral Dysmorphism and its Implication on the Size of the Sacroiliac Joint Surface.

STUDY DESIGN: This is a retrospective data analysis. OBJECTIVE: The aim of this study was to analyze the prevalence of sacral dysmorphism and its correlation to the size of the sacroiliac joint (SIJ) surface based on computed tomography (CT) scans. SUMMARY OF BACKGROUND DATA: Sacroiliac screw fixation is a widely accepted technique for stabilization of posterior pelvic ring injuries. Safe sacral screw placement may be impaired by sacral dysmorphism. The prevalence and impact of sacral dysmorphism on the size of the SIJ surface is unknown. MATERIALS AND METHODS: In total, 269 CT scans were evaluated for the presence of the 5 signs of sacral dysmorphism (mammillary bodies, tongue-in-groove, residual upper sacral disk space, colinearity, and dysmorphic sacral neural foramina). The size of the SIJ surface was calculated by measuring the sacral joint line of the SIJ on each axial CT slice. Logistic regression analyses were conducted to reveal sex-related or age-related differences and correlations between the presence of the dysmorphic signs and the size of the SIJ surface. RESULTS: Prevalence rates of the dysmorphic signs ranged from 5% (colinearity) to 70% (residual sacral disk space). Only 15% did not show any sign of sacral dysmorphism. The average size of the SIJ surface was 7.36 cm; it was significantly larger in male (8.46 cm) than in female (6.11 cm) patients (P<0.001). The presence of tongue-in-groove morphology was associated with a significantly larger SIJ surface (P<0.001), the presence of a residual upper sacral disk space with a significantly smaller joint surface (P=0.006). CONCLUSIONS: The prevalence of sacral dysmorphism is remarkably high in a normal population and it is questionable if the respective signs should be called dysmorphic after all. The possibility of a smaller joint surface in female patients and patients with a residual upper sacral disk space should be considered in the planning of iliosacral screw placement.

Arthroscopic and open treatment of cartilage lesions with BST-CARGEL scaffold and microfracture: A cohort study of consecutive patients.

BACKGROUND: CARGEL (Smith & Nephew Inc.), a chitosan-based polymer scaffolding biomaterial, has been used since 2012 for treating articular cartilage lesions. Limited data are available on patient outcomes following CARGEL treatment. This study aimed to describe short-term clinical and radiographic outcomes in a cohort of patients treated with CARGEL and microfracture surgery for articular cartilage defects in the knee. METHODS: A retrospective cohort study was conducted of consecutive patients with articular cartilage defects who had undergone microfracture surgery with CARGEL, or in patellar lesions microfracture and CARGEL plus Chondro-Gide (at SportsClinic Zurich). Study outcomes included reoperations, infections, allergic reactions, pain, swelling, range of motion, and tissue quality and quantity. Ethics approval was obtained from the local ethics committee on 05/09/2017 (Basec. Nr: 2017-01441). RESULTS: A total of 91 participants, with 93 treated lesions, consenting to chart review were included. No participants required reoperation due to complications on the index lesion. Fifteen participants had second-look surgery on the index knee for other reasons, allowing for visual confirmation of cartilage repair. No study participants experienced a post-surgical infection or suffered an allergic reaction. No significant changes in range of motion or T2 values were observed from pre-treatment to post-treatment follow-up. However, significant decreases were found in pain (P < 0.001) and swelling (P < 0.001), along with significant increases in MOCART II scores (P < 0.001). Similar results were found in a subgroup of patients with patellar lesions. CONCLUSIONS: Patients treated with CARGEL experienced few postoperative complications and reported promising reductions in pain and swelling after treatment. LEVEL OF EVIDENCE: IV.

Mid-term follow-up after surgical treatment of fragility fractures of the pelvis.

INTRODUCTION: Early operative treatment of fragility fractures of the pelvis (FFP) has been suggested to reduce pain and allow for earlier mobilization. The aim of this study was to determine mortality and functional outcome after operative treatment. PATIENTS AND METHODS: Patients aged ≥60 years (n = 60; mean age 79 years, 53 female) who had operative treatment of a FFP and a follow-up of at least 2 years were identified and mortality was assessed using a national social insurance database. Those who had survived were contacted by phone and a modified Majeed Score was obtained. RESULTS: At final follow up (62 months, range, 29-117), 32 patients (53.3%) had deceased. One-year-mortality rate was 28.3% and 2-year mortality was 36.7%. Mortality was not linked to fracture type (p > .05). Complications during hospitalization occurred in 26/60 patients (43.3%). Patients with a bilateral FFP had a longer hospitalization (18 vs. 11 days; p = .021). The mean modified Majeed score of surviving patients was 65 points (85.5% of achievable maximum). CONCLUSION: Mortality and in-hospital complications remain high among patients with FFP even when treated operatively. A longer hospitalization can be expected in patients with posterior bilateral fractures.

Medial acetabular wall breach in total hip arthroplasty - is full-weight-bearing possible?

BACKGROUND: A breach of the medial acetabular wall is a phenomenon seen frequently due to over-reaming during total hip arthroplasty (THA). The consequences of this issue are not fully understood particularly in cementless THA. A retrospective study was performed to answer whether: immediate postoperative full-weight-bearing in the presence of a medial acetabular wall breach after THA results in more short-term revisions of the acetabular component, and increases the risk for migration of the acetabular component? HYPOTHESIS: Immediate full-weight-bearing in the presence of a medial breach is not associated with an increased likelihood for acetabular-related revision surgery or migration of the cup. PATIENTS AND METHODS: In this retrospective cohort study, consecutive patients (n=95; mean age 68±13 years; 67 female) who underwent THA with an uncemented acetabular component were identified and a retrospective chart review was performed (follow-up 23±17 months, range 6 to 79 months). The presence of a postoperative radiographic medial acetabular breach was documented and the need for revision surgery and the rate of acetabular component migration were assessed during follow-up. RESULTS: Some extent of radiographic medial acetabular wall breach was seen in 26/95 patients (27%). With regard to the primary outcome, 2/95 patients (2%) required revision surgery during follow-up. All revision surgeries occurred in the group without a medial breach (p=0.280) for causes related to the femoral or the head components. Persistent pain was present in 1/26 patients (3.8%) in the medial breach group and 8/69 patients in the control group (11.6%; p=0.436). In the radiographic follow-up (n=81), there was no significant difference between the control group and the medial breach group with regard to cup migration (Δ ilio-ischial overlap [distance between the ilio-ischial line and a parallel line tangential to the acetabular cup on AP views]: -0.5±0.9mm [range, -2.9 to 0.8] vs. -0.3±1.7mm [range, -1.9 to 2.2], Δ overlap tangent [defined as the distance between the two crossings of ilio-ischial line and the acetabular component on AP views]: -2.2±6.1mm [range, -21.4 to 0.0] vs. 0.4±6.9mm [range, -6.2 to 17.6]). Similarly, according to variation in the ilio-ischial overlap distance between postoperative and follow-up on pelvic AP views, 0/56 hips (0%) had cup migration ≥ 5mm in the control group versus 1/25 (4%) in the medial breach cohort (p=0.3). DISCUSSION: In this retrospective observation of patients with immediate postoperative full-weight-bearing after THA, a radiographic breach of the medial acetabular wall was not associated with an increased risk for short-term revision surgery or radiographic migration at follow-up. According to the findings of this study and in the light of previous biomechanical studies, there is no clear evidence for postoperative partial weight-bearing in case of a medial breach as far as the surgeon feels that the acetabular component is stable. LEVEL OF EVIDENCE: IV, Retrospective cohort study.

Is rivaroxaban associated with higher morbidity and mortality in patients with traumatic head injuries? A retrospective cohort study comparing rivaroxaban, no anticoagulation, and phenprocoumon.

OBJECTIVES: The use of new anticoagulants potentially carries the risk of increased intracranial bleeding, but there is a lack of evidence. The aim of this study was to investigate whether the morbidity and mortality differs in head trauma patients depending on the type of anticoagulation. PATIENTS AND METHODS: A retrospective cohort study was conducted in 2009-2014. Based on sex, age, and Glasgow-Coma Scale (GCS), patients that received rivaroxaban were matched to two control groups, one that received no anticoagulant and another one that received phenprocoumon. The primary outcome was mortality. Among others, secondary outcome variables were the length of stay (LOS) at the hospital and presence of an intracranial injury. RESULTS: Sixty-nine patients (23 patients per group) were analyzed. The characteristics of patients did not differ significantly across groups. There were no significant differences between groups for the primary and secondary outcomes. Two patients died in the rivaroxaban group (one of them likely due to head trauma), while one patient died in the phenprocoumon group (likely not due to head trauma), and no patient died in the no anticoagulatoin group (p = 0.36). The LOS at the hospital was similar (5.0, 4.0, and 5.0 days; p = 0.94). An intracranial injury was observed in a similar number of patients in all groups (n = 11, n = 10, and n = 8; p = 0.75). CONCLUSION: Although limited in size, this study did not observe significant outcome differences in patients with traumatic head injuries, who received rivaroxaban, no anticoagulant or phenprocoumon. Although not significant, the only death likely due to head trauma in the study occurred in the rivaroxaban group. Larger studies are needed before clinical application of these findings.

Local effect of zoledronic acid on new bone formation in posterolateral spinal fusion with demineralized bone matrix in a murine model.

BACKGROUND: Posterolateral spinal fusion is a common orthopaedic surgery performed to treat degenerative and traumatic deformities of the spinal column. In posteriolateral spinal fusion, different osteoinductive demineralized bone matrix products have been previously investigated. We evaluated the effect of locally applied zoledronic acid in combination with commercially available demineralized bone matrix putty on new bone formation in posterolateral spinal fusion in a murine in vivo model. METHODS: A posterolateral sacral spine fusion in murine model was used to evaluate the new bone formation. We used the sacral spine fusion model to model the clinical situation in which a bone graft or demineralized bone matrix is applied after dorsal instrumentation of the spine. In our study, group 1 received decortications only (n = 10), group 2 received decortication, and absorbable collagen sponge carrier, group 3 received decortication and absorbable collagen sponge carrier with zoledronic acid in dose 10 µg, group 4 received demineralized bone matrix putty (DBM putty) plus decortication (n = 10), and group 5 received DBM putty, decortication and locally applied zoledronic acid in dose 10 µg. Imaging was performed using MicroCT for new bone formation assessment. Also, murine spines were harvested for histopathological analysis 10 weeks after surgery. RESULTS: The surgery performed through midline posterior approach was reproducible. In group with decortication alone there was no new bone formation. Application of demineralized bone matrix putty alone produced new bone formation which bridged the S1-S4 laminae. Local application of zoledronic acid to demineralized bone matrix putty resulted in significant increase of new bone formation as compared to demineralized bone matrix putty group alone. CONCLUSIONS: A single local application of zoledronic acid with DBM putty during posterolateral fusion in sacral murine spine model increased significantly new bone formation in situ in our model. Therefore, our results justify further investigations to potentially use local application of zoledronic acid in future clinical studies.

Current concepts in locking plate fixation of proximal humerus fractures.

Despite numerous available treatment strategies, the management of complex proximal humeral fractures remains demanding. Impaired bone quality and considerable comorbidities pose special challenges in the growing aging population. Complications after operative treatment are frequent, in particular loss of reduction with varus malalignment and subsequent screw cutout. Locking plate fixation has become a standard in stabilizing these fractures, but surgical revision rates of up to 25% stagnate at high levels. Therefore, it seems of utmost importance to select the right treatment for the right patient. This article provides an overview of available classification systems, indications for operative treatment, important pathoanatomic principles, and latest surgical strategies in locking plate fixation. The importance of correct reduction of the medial cortices, the use of calcar screws, augmentation with bone cement, double-plate fixation, and auxiliary intramedullary bone graft stabilization are discussed in detail.

Anterior subcutaneous internal fixation of the pelvis - what rod-to-bone distance is anatomically optimal?

INTRODUCTION: Anterior fixation of the pelvis using subcutaneous supra-acetabular pedicle screw internal fixation (INFIX) has proven to be a useful tool by avoiding the downsides of external fixation in patients where open fixation is not suited. The purpose of this study was to find a rod-to-bone distance for the INFIX that allows for minimal hazard to the inguinal neuro-vascular structures and, at the same time, as little as possible interference with the soft tissues of the proximal thigh when the patient is sitting. METHODS: An INFIX was applied to 10 soft-embalmed cadaver pelvises with three different rod-to-bone distances. With each configuration, the relations of the rod to the neuro-vascular and the muscular surroundings were measured in supine and sitting position. RESULTS: Except for the femoral artery, vein and nerve, all investigated anatomical structures of the groin were under compression with a rod-to-bone distance of 1cm. With a rod-to-bone distance of 2cm most of the anatomical structures were safe in supine position, although less than with 3cm. With hip flexion some structures got under compression, especially the lateral femoral cutaneous nerve (LFCN, 80%) and the anterior cutaneous branches of the femoral nerve (ACBFN, 35%). With a rod-to-bone distance of 3cm almost all anatomical structures were safe in supine position, while with hip flexion most superficial structures of the proximal thigh got under compression, especially the LFCN (75%) and the ACBFN (60%). CONCLUSIONS: Aiming for a rod-to-bone distance of 2cm is the safest way with regard to compression of the femoral neuro-vascular bundle and at the same time leads to the least compression of more superficial structures like the LFCN, the ACBFN, or the sartorius and the rectus femoris muscles in sitting position.

Guide wire insertion for percutaneous LC2 screws in acetabular and pelvic ring fixation using a transpedicular working cannula.

Closed reduction and percutaneous screw fixation (CRIF) of iliac crescent fractures and fractures of the anterior column of the acetabulum has become an established method in the treatment of these injuries. After reduction, safe insertion of a guide wire is a key step during this procedure. We present a technique that can facilitate introducing the guide wire under fluoroscopic guidance and allow for decreased radiation exposure.