Biomechanical comparison of a 3.5 mm anterior locking plate to cannulated screws with anterior tension band wiring in comminuted patellar fractures.

PURPOSE: To date, surgically treated multifragmentary patellar fractures are still associated with high rates of complications, such as i.e. secondary fracture displacement. Osteosynthesis is most frequently performed with screws and cerclages. To increase primary stability, locking plates have been introduced. However, there is still a lack of biomechanical data supporting the superiority of plate fixation compared to screw fixation with cerclages in these cases. The goal of the present study was to conduct biomechanical comparison of these two techniques under dynamic loading conditions. METHODS: A standardized 34-C3 fracture was created in eight pairs of human cadaveric knee joints. Following a randomization protocol, they were fixed with a 3.5 mm anterior locking plate (LP) or cannulated screws with anterior tension band wiring (hybrid osteosynthesis, HO).Subsequently, all constructs were tested for 100 cycles from 90° of knee-flexion to full extension by applying a pulling force to the quadriceps tendon. Outcome parameters were fracture displacement after one cycle, after 100 cycles and implant loosening. Failure was defined as fracture displacement > 2 mm. RESULTS: Biomechanical testing showed significantly less fracture displacement following LP compared to HO both after the first (p = 0.042) and after 100 cycles (p = 0.025). The difference in loosening was significant as well (p = 0.017). Following HO, 5/8 constructs failed during cyclic loading. There was no failure in the LP group. In the HO group, loosening correlated with bone mineral density (R = - 0.857) which was not observed in the LP group (R = - 0.429). CONCLUSION: Anterior locking plate osteosynthesis of comminuted patellar fractures biomechanically provides better primary stability compared to cannulated screws with anterior tension band wiring.

Pelvic fractures in severely injured children: Results from the TraumaRegister DGU.

Injuries in the pelvic region in children and adolescents are very rare and often associated with a high energy trauma. Aim of this prospective multicenter study was, by analyzing the data from the TraumaRegister Deutsche Gesellschaft für Unfallchirurgie (TR-DGU), to evaluate any correlation between the severity of pelvic fractures and resulting mortality in different age groups.These study findings are based on a large pool of data retrieved from the prospectively-setup pelvic trauma registry established by the German Trauma Society (DGU) and the German Section of the Association for Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) International in 1991. The registry provides data on all patients suffering pelvic fractures within a 14-year time frame at any 1 of the 23 level 1 trauma centers contributing to the registry. The analysis covers 4 age groups ranging from 0 to 17 years, covering different factors regarding pelvic fractures and their treatment.We identified a total of 9684 patients including 1433 pelvic fractures in children aged ≤17 years. Those patients were divided into 4 subgroups according to the patients' age (groups A-D) and according to the fracture severity (group 1 =  Abbreviated Injury Scale (AIS) score pelvis ≤2, and group 2 = AIS pelvis ≥3). The mortality in group 1 was 8.8% with a RISC (Revised Injury Severity Score) II of 8.6%, standard mortality rate (SMR) of 1.02 and 7.2% in group 2 with an RISC II of 9.9% (SMR 0.73). In pelvic factures of Type A (Tile classification of pelvic fractures), an SMR of 0.76 was recorded, in Type B fractures the SMR was 0.65, and in Type C fractures 0.79. Severe pelvic injuries (AIS pelvis ≥2) were associated with a higher rate of whole body computer tomograph (CT) scans (1-5 years: 80%, 6-10 years 81.8%, 11-14 years 84.7%, and 15-17 years 85.6%). The rate of pelvic surgery rose with the pelvic injury's severity (AIS 2: 7.6%, AIS 3: 35%, AIS 4: 65.6%, AIS 5 61.5%). We observed higher rates of preclinical and initial clinical hypotension defined as Riva-Rocci (RR) <90 mmHG) as well as of preclinical fluid application in all age groups. The presence of a pelvic injury was associated with a higher rate of severe abdominal injuries with an AIS of ≥3 (25.1% vs. 14.6%) and of severe thorax injuries with an AIS≥3 (43.6% vs. 28.6%).We have been able to analyze an enormous number of pelvic fractures in children and adolescents including different age groups by relying on data from the TR-DGU. Mortality seems to be associated with the severity of the pelvic injury, but is lower than the RISC II score's prognosis.

[Differences in the outcome of seriously injured children depending on treatment level]. / Unterschiede im Outcome schwerverletzter Kinder in Abhängigkeit von der Versorgungsstufe.

INTRODUCTION: Many publications, mainly from other countries, suggest that the treatment of seriously injured children might be better in specialised paediatric trauma centres than in general trauma centres. Data from Germany are not available yet, but those from abroad were used for the recommendations made by the German Association for Trauma Surgery (DGU) on the topic of paediatric trauma in the "White Paper on Trauma Care". The goal of this study was to analyse whether the outcome of severely injured children is dependent on treatment level and on the availability of a paediatric surgeon based on the given data. MATERIALS AND METHODS: Data from the "TraumaRegister DGU" between 2002 and 2012 were used. Children aged 1-15 years treated during the period 2002-2012 were included. Severity had to reach a minimum Injury Severity Score (ISS) of 9 and the treatment had to involve a stay at an Intensive Care Unit. Patients with an ISS ≥9 who died were also included to take into consideration children with particularly severe injuries. RESULTS: Hospitals without a paediatric surgeon transferred the patients significantly more frequently (p < 0.001). Mean hospital stay was shorter in centres with a paediatric surgeon, with slightly longer median stays at an Intensive Care Unit. Hospitals without a paediatric surgeon performed slightly more frequent surgical interventions on injured children (barely significant at p = 0.045). The death rate and the calculated Revised Injury Severity Classification (RISC) II prognosis were the same with or without the presence of a paediatric surgeon. No difference was found in the Glasgow Outcome Score (GOS) between the group with and the group without involvement of a paediatric surgeon. DISCUSSION: Overall, the medical care of seriously injured and polytraumatised children in Germany is good at all levels of treatment whether a paediatric surgeon is involved or not.

Early mechanical stimulation only permits timely bone healing in sheep.

Bone fracture healing is sensitive to the fixation stability. However, it is unclear which phases of healing are mechano-sensitive and if mechanical stimulation is required throughout repair. In this study, a novel bone defect model, which isolates an experimental fracture from functional loading, was applied in sheep to investigate if stimulation limited to the early proliferative phase is sufficient for bone healing. An active fixator controlled motion in the fracture. Animals of the control group were unstimulated. In the physiological-like group, 1 mm axial compressive movements were applied between day 5 and 21, thereafter the movements were decreased in weekly increments and stopped after 6 weeks. In the early stimulatory group, the movements were stopped after 3 weeks. The experimental fractures were evaluated with mechanical and micro-computed tomography methods after 9 weeks healing. The callus strength of the stimulated fractures (physiological-like and early stimulatory) was greater than the unstimulated control group. The control group was characterized by minimal external callus formation and a lack of bone bridging at 9 weeks. In contrast, the stimulated groups exhibited advanced healing with solid bone formation across the defect. This was confirmed quantitatively by a lower bone volume in the control group compared to the stimulated groups.The novel experimental model permits the application of a well-defined load history to an experimental bone fracture. The poor healing observed in the control group is consistent with under-stimulation. This study has shown early mechanical stimulation only is sufficient for a timely healing outcome. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1790-1796, 2018.

Complications after surgical management of distal lower leg fractures.

BACKGROUND: Osseous healing of distal lower leg fractures can be prolonged and is often associated with wound healing problems because of the marginal soft - tissue and vascular supply in this area. Postoperative complications are frequent, and according to the literature, open reduction and plate fixation is thought to be associated with higher complication rates. The objective of this study was to evaluate the most common postoperative complications following intramedullary nailing or plate osteosynthesis of distal lower leg injuries with a focus on combined tibio-fibular fractures. The outcomes of patients with and without complications associated the two surgical techniques were compared. METHODS: During a 5-year period, all surgically treated distal tibiofibular fractures were retrospectively collected from the clinical database and were evaluated for the presence of postoperative complications which included compartment syndrome, wound infection, delayed union and non-union, synostosis and rotational malalignment. Postoperative complications were reviewed and correlated with patient risk factors. RESULTS: A total of 199 patients were included in the study, and 75 complications were reported. The majority of complications were associated with closed fracture types treated with intramedullary nailing, delayed union being the most frequent. For open fractures, surgical treatment with plate fixation had a complication rate of 12% compared with 25% after intramedullary nailing. DISCUSSION: In general, distal lower leg fractures are associated with a high risk of postoperative complications. Distal diaphyseal tibial fractures that have been treated with intramedullary nailing devices have a higher risk of delayed union or non - union. CONCLUSION: Plate fixation in distal metaphyseal fractures has a higher risk of problems related to wound healing and postoperative wound infections.

Intra-articular tibial plateau fracture characteristics according to the "Ten segment classification".

BACKGROUND: Currently existing classifications of tibial plateau fractures do not help to guide surgical strategy. Recently, a segment-based mapping of the tibial plateau has been introduced in order to address fractures with a fracture-specific surgical approach. The goal of the present study was to analyze incidence and fracture specifics according to a new 10-segment classification of the tibial plateau. METHODS: A total of 242 patients with 246 affected knees were included (124 females, 118 males, mean age 51.9±16.1years). Fractures were classified according to the OTA/AO classification. Fracture pattern was analyzed with respect to a 10-segment classification based on CT imaging of the proximal tibial plateau 3cm below the articular surface. RESULTS: 161 Patients suffered an OTA/AO type 41-B and 85 patients an OTA/AO type 41-C tibial plateau fracture. Females had an almost seven times higher risk to suffer a fracture due to low-energy trauma (OR 6.91, 95% CI (3.52, 13.54), p<0.001) than males. In 34% of the patients with affection of the medial tibial plateau, a fracture comminution, primarily due to low-energy trauma (p<0.001), was observed. In type B fractures, the postero-latero-lateral (65.2%), the antero-latero-lateral (64.6%) and the antero-latero-central (60.9%) segment were most frequently affected. Every second type C fracture showed an unique fracture line and zone of comminution. The tibial spine was typically involved (89.4%). A typical fracture pattern of high-energy trauma demonstrated a zone of comminution of the lateral plateau and a split fracture in the medial plateau. The most frequently affected segments were the postero-latero-central (85.9%), postero-central (84.7%), and antero-latero-central (78.8%) segment. CONCLUSION: Posterior segments were the most frequently affected in OTA/AO type B and C fractures. Acknowledging the restricted visibility of posterior segments, whose reduction and fixation is crucial for long-term success, our findings implicate the use of posterior approaches more often in the treatment of tibial plateau fractures. Also, low-energy trauma was identified as an important cause for tibial plateau fractures.

Current profile of cycling injuries: A retrospective analysis of a trauma centre level 1 in Queensland.

OBJECTIVES: One out of 50 injury-related presentations to an ED is a transport-related cycling injury. Detailed information about the most frequent mechanism of cycling injuries, sustained injuries and patterns are under-reported. The objective of this research was to examine the pattern of injuries sustained by cyclists at a level 1 trauma centre. METHODS: A retrospective review of data of injured cyclists admitted and treated at a level 1 trauma centre between 2011 and 2012 evaluated demographic data, mechanism of injury, injury pattern, economic costs and outcome. RESULTS: Data of 261 patients (mean age of 39 years) were reviewed, of which 88% was male patients with an average age of 38 years. Non-collision cycling injuries were reported in 55% of cases followed by collisions with other motor vehicles in 25.6% of cases. The mean injury severity score (ISS) was 9, but an ISS ≥ 12 was documented in 24%. Predominantly upper limb injuries (24.8%) were found, followed by injuries to the head and lower limb (each with 16.8%). Traumatic brain and chest injuries were equally seen in 8%. The overall length of stay was 4 days, and survival rate was 98%. CONCLUSION: This current data review reveals that non-collision traffic crashes accounted for the majority of injuries in cyclists treated in this facility, and the upper limb has replaced the head as the most injured body part. With a growing number of cyclists, this information contributes to considerations to improve road safety and trauma management.

Pelvic Fractures in Children Results from the German Pelvic Trauma Registry: A Cohort Study.

As pelvic fractures in children and adolescents are very rare, the surgical management is not well delineated nor are the postoperative complications. The aim of this study using the prospective data from German Pelvic Trauma Registry study was to evaluate the various treatment approaches compared to adults and delineated the differences in postoperative complications after pelvic injuries.Using the prospective pelvic trauma registry established by the German Society of Traumatology and the German Section of the Arbeitsgemeinschaft für Osteosynthesefragen (AO), International in 1991, patients with pelvic fractures over a 12-year time frame submitted by any 1 of the 23 member level I trauma centers were reviewed.We identified a total of 13,525 patients including pelvic fractures in 13,317 adults and 208 children aged ≤14 years and compared these 2 groups. The 2 groups' Injury Severitiy Score (ISS) did not differ statistically. Lethality in the pediatric group was 6.3%, not statistically different from the adults' 4.6%. In all, 18.3% of the pediatric pelvic fractures were treated surgically as compared to 22.7% in the adult group. No child suffered any thrombosis/embolism, acute respiratory distress syndrome (ARDS), multiorgan failure (MOF), or neurologic deficit, nor was any septic MOF detected. The differences between adults and children were statistically significant in that the children suffered less frequently from thrombosis/embolism (P = 0.041) and ARDS and MOF (P = 0.006).This prospective multicenter study addressing patients with pelvic fractures reveals that the risk for a thrombosis/embolism, ARDS, and MOF is significant lower in pediatric patients than in adults. No statistical differences could be found in the ratios of operative therapy of the pelvic fractures in children compared to adults.

Arthroscopic versus open cam resection in the treatment of femoroacetabular impingement.

PURPOSE: The purpose of this study was to evaluate if osseous correction of the femoral neck achieved arthroscopically is comparable to that achieved by surgical dislocation. METHODS: We retrospectively analyzed all patients who were treated with hip arthroscopy or surgical dislocation for cam or mixed type femoroacetabular impingement (FAI) in our institution between 2006 and 2009. Inclusion criteria were complete clinical and radiologic documentation with standardized radiographs. Group 1 consisted of 66 patients (49 female patients, mean age 33.8 years) treated with hip arthroscopy. Group 2 consisted of 135 patients (91 male patients, mean age 31.2 years) treated with surgical hip dislocation. We compared the preoperative and postoperative alpha and gamma angles, as well as the triangular index. Mean follow-up was 16.7 months (range, 2 to 79 months). RESULTS: In group 1, the mean alpha angle improved from 60.7° preoperatively to 47.8° postoperatively (P < .001) and the mean gamma angle improved from 47.3° to 44.5° (P < .001). Over time, the preoperative mean alpha angle increased from 56.3° in 2006 to 67.5° in 2009, whereas the postoperative mean alpha angle decreased from 51.2° in 2006 to 47.5° in 2009. In group 2, the mean alpha angle improved from 75.3° preoperatively to 44.8° postoperatively (P < .001), and the mean gamma angle improved from 65.1° to 52.2° (P < .001). Arthroscopic revision of intra-articular adhesions was performed in 4 patients (6.1%) in group 1 and 16 patients (12%) in group 2. Three patients (2.2%) in group 2 underwent revision for nonunion of the greater trochanter. CONCLUSIONS: Osseous correction of cam-type FAI with hip arthroscopy is comparable to the correction achieved by surgical hip dislocation. There is a significant learning curve for hip arthroscopy, with postoperative osseous correction showing improved results with increasing surgical experience. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Impingement-free hip motion: the 'normal' angle alpha after osteochondroplasty.

Femoroacetabular impingement is considered a cause of hip osteoarthrosis. In cam impingement, an aspherical head-neck junction is squeezed into the joint and causes acetabular cartilage damage. The anterior offset angle alpha, observed on a lateral crosstable radiograph, reflects the location where the femoral head becomes aspheric. Previous studies reported a mean angle alpha of 42 degrees in asymptomatic patients. Currently, it is believed an angle alpha of 50 degrees to 55 degrees is normal. The aim of this study was to identify that angle alpha which allows impingement-free motion. In 45 patients who underwent surgical treatment for femoroacetabular impingement, we measured the angle alpha preoperatively, immediately postoperatively, and 1 year postoperatively. All hips underwent femoral correction and, if necessary, acetabular correction. The correction was considered sufficient when, in 90 degrees hip flexion, an internal rotation of 20 degrees to 25 degrees was possible. The angle alpha was corrected from a preoperative mean of 66 degrees (range, 45 degrees - 79 degrees) to 43 degrees (range, 34 degrees - 60 degrees) postoperatively. Because the acetabulum is corrected to normal first, the femoral correction is tested against a normal acetabulum. We therefore concluded an angle alpha of 43 degrees achieved surgically and with impingement-free motion, represents the normal angle alpha, an angle lower than that currently considered sufficient.

Osteocalcin enhances bone remodeling around hydroxyapatite/collagen composites.

The effect of osteocalcin (OC), an extracellular bone matrix protein, on bone healing around hydroxyapatite/collagen composites was investigated. Cylindrical nanocrystalline hydroxyapatite implants of 2.5-mm diameter containing 2.5% biomimetically mineralized collagen type I were inserted press-fit into the tibial head of adult Wistar rats. To one implant group, 10 mug/g OC was added. Six specimens per group were analyzed at 2, 7, 14, 28, and 56 days. After 14 days, newly formed woven bone had reached the implant surface of the OC implants whereas a broad fibrous interface could still be observed around controls. Woven bone was formed directly around both implant groups after 28 days and had been replaced partially by lamellar bone around the OC implants only. No significant differences in total bone contact were seen between both groups after 56 days. The higher number of phagocytosing cells and osteoclasts characterized immunohistochemically with ED1, cathepsin D, and tartate-resistant alkaline phosphatase around the OC implants at the early stages of bone healing suggests an earlier onset of bone remodeling. The earlier and increased expression of bone-specific matrix proteins and multifunctional adhesion proteins (osteopontin, bone sialoprotein, CD44) at the interface around the OC implants indicates that OC may accelerate bone formation and regeneration. This study supports the observations from in vitro studies that OC activates both osteoclasts and osteoblasts during early bone formation.