Vascularization Strategies in the Prevention of Nonunion Formation.

Delayed healing and nonunion formation are major challenges in orthopedic surgery, which require the development of novel treatment strategies. Vascularization is considered one of the major prerequisites for successful bone healing, providing an adequate nutrient supply and allowing the infiltration of progenitor cells to the fracture site. Hence, during the last decade, a considerable number of studies have focused on the evaluation of vascularization strategies to prevent or to treat nonunion formation. These involve (1) biophysical applications, (2) systemic pharmacological interventions, and (3) tissue engineering, including sophisticated scaffold materials, local growth factor delivery systems, cell-based techniques, and surgical vascularization approaches. Accumulating evidence indicates that in nonunions, these strategies are indeed capable of improving the process of bone healing. The major challenge for the future will now be the translation of these strategies into clinical practice to make them accessible for the majority of patients. If this succeeds, these vascularization strategies may markedly reduce the incidence of nonunion formation. Impact statement Delayed healing and nonunion formation are a major clinical problem in orthopedic surgery. This review provides an overview of vascularization strategies for the prevention and treatment of nonunions. The successful translation of these strategies in clinical practice is of major importance to achieve adequate bone healing.

NSM00158 Specifically Disrupts the CtBP2-p300 Interaction to Reverse CtBP2-Mediated Transrepression and Prevent the Occurrence of Nonunion.

Carboxyl-terminal binding proteins (CtBPs) are transcription regulators that control gene expression in multiple cellular processes. Our recent findings indicated that overexpression of CtBP2 caused the repression of multiple bone development and differentiation genes, resulting in atrophic nonunion. Therefore, disrupting the CtBP2-associated transcriptional complex with small molecules may be an effective strategy to prevent nonunion. In the present study, we developed an in vitro screening system in yeast cells to identify small molecules capable of disrupting the CtBP2-p300 interaction. Herein, we focus our studies on revealing the in vitro and in vivo effects of a small molecule NSM00158, which showed the strongest inhibition of the CtBP2-p300 interaction in vitro. Our results indicated that NSM00158 could specifically disrupt CtBP2 function and cause the disassociation of the CtBP2-p300-Runx2 complex. The impairment of this complex led to failed binding of Runx2 to its downstream targets, causing their upregulation. Using a mouse fracture model, we evaluated the in vivo effect of NSM00158 on preventing nonunion. Consistent with the in vitro results, the NSM00158 treatment resulted in the upregulation of Runx2 downstream targets. Importantly, we found that the administration of NSM00158 could prevent the occurrence of nonunion. Our results suggest that NSM00158 represents a new potential compound to prevent the occurrence of nonunion by disrupting CtBP2 function and impairing the assembly of the CtBP2-p300-Runx2 transcriptional complex.

Risk Factors for Tibial Plafond Nonunion: Medial Column Fixation May Reduce Nonunion Rates.

OBJECTIVES: To identify the incidence and risk factors for development of tibial plafond nonunion. DESIGN: Retrospective comparative study. SETTING: Two Level 1 academic trauma centers. PATIENTS/PARTICIPANTS: Seven hundred forty tibial plafond fractures (OTA/AO 43B3 and 43C) treated January 2006 to December 2015. INTERVENTION: Open reduction and internal fixation. MAIN OUTCOME MEASUREMENT: Nonunion. RESULTS: Five hundred eighteen patients with a mean age of 43 years (range, 18-81 years) and mean follow-up of 27 months (range, 12-115 months) were involved. Seventy-two patients (72/518, 14%) were identified as having a nonunion. Surgical approach was not associated with nonunion in univariate analysis. Multiple regression model 1 identified OTA/AO 43C [odds ratio (OR) = 4.43; 95% confidence interval (CI), 1.01-19.41; P = 0.048], tobacco use (OR = 2.02; 95% CI, 1.10-3.71; P = 0.024), both minimal and substantial bone loss (P = 0.006 and P < 0.001, respectively), and open fracture (OR = 1.96; 95% CI, 1.10-3.48; P = 0.022) as risk factors for tibial plafond nonunion. Model 2 identified locking plate (OR = 1.97; 95% CI, 1.13-3.40; P = 0.016) and failure to treat the medial column (vs. screw P = 0.047, or plate P = 0.038) as risk factors. CONCLUSIONS: The tibial plafond nonunion rate was 14%. Bone loss, open fracture, failure to treat the medial column, locking plates, and tobacco use were all significant risk factors for developing tibial plafond nonunion. Equally important, surgical approach was not significantly associated with plafond nonunion. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Hyperglycaemia is an under-appreciated but modifiable risk factor in managing people with type 1 diabetes and fragility fractures.

There are two major musculoskeletal effects of Type 1 diabetes mellitus (T1DM) - fragility fractures and impaired fracture union. Fractures in these patients are a significant and limb threatening injury. Traditionally, they have been treated with prolonged immobilisation and as rigid as possible internal fixation. Recently, hyperglycaemia has been recognised as the most significant modifiable risk factor in treating patients with T1DM and fractured limbs. This article reviews this association further and outlines the role of orthopaedic surgeons in minimising orthopaedic-related complications.

How common are vascular injuries in open tibial fractures? A prospective longitudinal cohort study.

BACKGROUND: Tibial fractures have an incidence of 15% of all adult fractures. They have been shown to have the highest incidence of non-union in long bone fractures and the highest incidence of vascular injury. Evidence from the literature suggests that a good vascular supply is important to ensure bone union. The aim of our study was to prospectively assess the incidence of vascular injuries in open tibial fractures and determine whether they were associated with an increased risk of non-union. METHODS: We performed a prospective study to investigate the incidence of arterial injuries with computed tomography angiography (CTA) in patients with Gustilo-Anderson grade I-III open tibial fractures between 2013 and 2015. CTA was performed with the trauma series at acute admission and reported by two independent musculoskeletal radiologists. Patients were followed up with clinical and radiographic assessment for 1 year. RESULTS: We recruited 77 patients into the study, and 56 patients (47 males, 9 females) were available for the final analysis, between 16 and 90 years of age. At the initial assessment, 29% had signs of arterial injury with active extravasation in 5%. The most common site of injury was in the diaphysis (87.5%), and the commonest mechanism was a road traffic accident. We found no significant relation between occult vascular injury and non-union (p > 0.05). CONCLUSION: The incidence of vascular injury in open tibial fractures is 29%, and CTA is therefore a useful test in identifying vascular injuries that may require vascular intervention.

Vitamin D and Metabolic Supplementation in Orthopedic Trauma.

Active assessment and management of hypovitaminosis D among orthopedic patients is low-risk and low-cost while retaining significant potential to improve patient care. Vitamin D has an established role in musculoskeletal development and calcium homeostasis, and vitamin D deficiency is pervasive in orthopedic trauma populations. Clinical guidelines for screening and supplementation for hypovitaminosis D are lacking. Literature on the effects of vitamin K on bone health is limited. Anabolic hormone analogues may have a future role in delayed union or nonunion treatment. Vitamin D deficiency and other endocrine abnormalities should be considered in orthopedic trauma patients presenting with fracture nonunion of uncertain cause.

Is dynamic locking plate superior than other implants for intracapsular hip fracture: A meta-analysis.

BACKGROUND: We studied the safety and efficacy of dynamic locking plate vs. other implants (cannulated cancellous screws [CCS] or sliding hip screw [SHS]) in patients undergoing intracapsular hip fracture (ICHF). METHODS: We searched Pubmed, Embase, Web of Science, Cochrane library and Google database from inception to March 25, 2018. We selected any studies comparing dynamic locking plate for treatment ICHF. Non-union rate, osteonecrosis rate, cutout rate, revision rate, the replacement rate, and Harris hip scores were the outcomes. Stata 12.0 was used for meta-analysis. RESULTS: Four studies involving 419 patients (143 patients in the dynamic locking plate group and 276 patients in the other implants group) were finally included. Compared with CCS or SHS, dynamic locking plate was associated with a reduction of nonunion rate, revision rate, replacement rate (P <.05). Furthermore, dynamic locking plate was also associated with an increase of the Harris hip scores (P <.05). There was no significant difference between the osteonecrosis rate and cutout rate (P >.05). CONCLUSIONS: Current meta-analysis revealed that dynamic locking plate has a benefit role in improving postoperative clinical outcome than CCS or SHS in ICHF patients. Further high quality and large-scale randomized controlled trials (RCTs) are needed to further identify the efficacy of dynamic locking plate for ICHF.

Preclinical therapies to prevent or treat fracture non-union: A systematic review.

BACKGROUND: Non-union affects up to 10% of fractures and is associated with substantial morbidity. There is currently no single effective therapy for the treatment or prevention of non-union. Potential treatments are currently selected for clinical trials based on results from limited animal studies, with no attempt to compare results between therapies to determine which have the greatest potential to treat non-union. AIM: The aim of this systematic review was to define the range of therapies under investigation at the preclinical stage for the prevention or treatment of fracture non-union. Additionally, through meta-analysis, it aimed to identify the most promising therapies for progression to clinical investigation. METHODS: MEDLINE and Embase were searched from 1St January 2004 to 10th April 2017 for controlled trials evaluating an intervention to prevent or treat fracture non-union. Data regarding the model used, study intervention and outcome measures were extracted, and risk of bias assessed. RESULTS: Of 5,171 records identified, 197 papers describing 204 therapies were included. Of these, the majority were only evaluated once (179/204, 88%), with chitosan tested most commonly (6/204, 3%). Substantial variation existed in model design, length of survival and duration of treatment, with results poorly reported. These factors, as well as a lack of consistently used objective outcome measures, precluded meta-analysis. CONCLUSION: This review highlights the variability and poor methodological reporting of current non-union research. The authors call for a consensus on the standardisation of animal models investigating non-union, and suggest journals apply stringent criteria when considering animal work for publication.

Comparison of early complications between the use of a cannulated screw locking plate and multiple cancellous screws in the treatment of displaced intracapsular hip fractures in young adults: a randomized controlled clinical trial.

BACKGROUND: The incidence of early postoperative complications of displaced intracapsular hip fractures is high. The purpose of this study was to compare the early postoperative complications and assess the incidence of femoral neck shortening on using a newly designed proximal femoral cannulated screw locking plate (CSLP) versus multiple cancellous screws (MCS) in the treatment of displaced intracapsular hip fractures in young adults. METHODS: Sixty-eight young adult patients with displaced intracapsular hip fractures were randomly assigned to either the CSLP group or the MCS group and treated routinely by internal fixation with either the CSLP or the MCS. Harris Hip Score, nonunion, failure of fixation, overall complications, and femoral neck shortening were recorded and compared. RESULTS: Two patients (5.88%) in the CSLP group and eight (23.53%) in the MCS group had postoperative nonunion (P < 0.05). There was one case (2.94%) of fixation failure in the CSLP group and three cases (8.82%) in the MCS group (P > 0.05). Three patients (8.82%) in the CSLP group and 11 (32.35%) in the MCS group had overall complications (P < 0.05). Mean femoral neck shortening was 5.10 mm in the vertical plane and 5.11 mm in the horizontal plane in the CSLP group and 11.14 mm in the vertical plane and 10.51 mm in the horizontal plane in the MCS group. Severe femoral neck shortening (≥ 10 mm) did not occur in either the vertical or the horizontal plane in any patient of the CSLP group but occurred in 10 patients (28.57%) in the vertical plane and in 8 (22.86%) patients in the horizontal plane in the MCS group. CONCLUSIONS: Compared with MCS, the use of CSLP in the treatment of displaced intracapsular hip fractures in young adults can reduce the rates of postoperative nonunion and overall complications and minimize femoral neck shortening. TRIAL REGISTRATION: ChiCTR1800016032 . Registered 8 May 2018. Retrospectively registered.

Dorsal closing wedge calcaneal osteotomy for the treatment of Insertional Achilles Tendinopathy: A technical tip to optimize its results and reduce complications.

BACKGROUND: Dorsal closing wedge calcaneal osteotomy is a technique for the treatment of Haglund's triad, which is considered a safe procedure with good results. However, one of the complications that could lead to revision operation is the nonunion of the osteotomy and failure of osteosynthesis. This is attributed to instability of the osteotomy site and proximal migration of the posterior calcaneal process due to breakage of plantar bone-bridge at the apex of the wedge osteotomy. METHODS: This study presents a technical tip that helps the surgeon to avoid the breakage of the plantar hinge of the os calcis which is believed that causes instability of the osteotomy. RESULTS: After the utilization of that technical tip, no proximal migration of posterior calcaneal process or subsequent nonunion and failure of the osteosynthesis was noted. CONCLUSION: Dorsal closing wedge osteotomy is a technique for the treatment of IAT, which is considered a safe procedure with good results. The proposed technical tip helps to avoid the breakage of the plantar hinge which is believed that causes instability of the osteotomy with proximal migration of the posterior calcaneal process and subsequent nonunion and failure of the osteosynthesis.

Effect of Blocking Screws on Union of Infraisthmal Femur Fractures Stabilized With a Retrograde Intramedullary Nail.

OBJECTIVE: To investigate the effect of blocking screws (BS) on the union rate and stability of infraisthmal femur fractures treated with retrograde intramedullary nail (RIMN) insertion. DESIGN: Retrospective cohort study. SETTING: A single level 1 trauma center. PATIENTS/PARTICIPANTS: All patients with an infraisthmal femur fracture treated with a RIMN from 2005 to 2012 were included. INTERVENTION: All fractures were treated with a RIMN. BS were used at the discretion of the treating surgeon. MAIN OUTCOME MEASUREMENTS: (1) Radiographic time to union, (2) initial postoperative sagittal and coronal angulation, and (3) final sagittal and coronal angulation. RESULTS: Neither the average time to union (BS 21.1 weeks vs. 21.8 weeks), nor union rates (BS 61% vs. 77%) were statistically different between BS and non-BS constructs. No significant alignment differences existed whether BS were used or not. CONCLUSIONS: In this study, we were not able to verify our hypothesis. In fact, we did not find any significant advantages when BS were added to a RIMN construct for distal femur fractures with respect to union time, union rate, or improvements in alignment. Additional studies are needed to determine the actual benefit of BS in the treatment of infraisthmal femoral shaft fractures treated with retrograde intramedullary nailing. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Preoperative CT planning of screw length in arthroscopic Latarjet.

PURPOSE: The Latarjet procedure has shown its efficiency for the treatment of anterior shoulder dislocation. The success of this technique depends on the correct positioning and fusion of the bone block. The length of the screws that fix the bone block can be a problem. They can increase the risk of non-union if too short or be the cause of nerve lesion or soft tissue discomfort if too long. Suprascapular nerve injuries have been reported during shoulder stabilisation surgery up to 6 % of the case. Bone block non-union depending on the series is found around 20 % of the cases. The purpose of this study was to evaluate the efficiency of this CT preoperative planning to predict optimal screws length. The clinical importance of this study lies in the observation that it is the first study to evaluate the efficiency of CT planning to predict screw length. METHODS: Inclusion criteria were patients with chronic anterior instability of the shoulder with an ISIS superior to 4. Exclusion criteria were patients with multidirectional instability or any previous surgery on this shoulder. Thirty patients were included prospectively, 11 of them went threw a CT planning, before their arthroscopic Latarjet. Optimal length of both screws was calculated, adding the size of the coracoid at 5 and 15 mm from the tip to the glenoid. Thirty-two-mm screws were used for patients without planning. On a post-operative CT scan with 3D reconstruction, the distance between the screw tip and the posterior cortex was measured. A one-sample Wilcoxon test was used to compare the distance from the tip of the screw to an acceptable positioning of ±2 mm from the posterior cortex. RESULTS: In the group without planning, screw 1 tended to differ from the acceptable positioning: mean 3.44 mm ± 3.13, med 2.9 mm, q1; q3 [0.6; 4.75] p = 0.1118, and screw 2 differed significantly from the acceptable position: mean 4.83 mm ± 4.11, med 3.7 mm, q1; q3 [1.7; 5.45] p = 0.0045. In the group with planning, position of screw 1 or 2 showed no significant difference from the acceptable position: mean 2.45 mm ± 2.07 med 1.8 mm, q1; q3 [1; 3.3] p = 1; mean 2.75 mm ± 2.32 med 2.3 mm, q1; q3 [1.25; 3.8] p = 0.5631. CONCLUSION: Unplanned Latarjet can lead to inaccurate screw length especially in the lower screw and can increase the risk of non-union and nerve damage. The clinical relevance of this article is that CT planning of screw length before surgery showed good results on post-operative CT.

The effect of a single early high-dose vitamin D supplement on fracture union in patients with hypovitaminosis D: a prospective randomised trial.

AIMS: To evaluate the effect of a single early high-dose vitamin D supplement on fracture union in patients with hypovitaminosis D and a long bone fracture. PATIENTS AND METHODS: Between July 2011 and August 2013, 113 adults with a long bone fracture were enrolled in a prospective randomised double-blind placebo-controlled trial. Their serum vitamin D levels were measured and a total of 100 patients were found to be vitamin D deficient (< 20 ng/ml) or insufficient (< 30 ng/mL). These were then randomised to receive a single dose of vitamin D3 orally (100 000 IU) within two weeks of injury (treatment group, n = 50) or a placebo (control group, n = 50). We recorded patient demographics, fracture location and treatment, vitamin D level, time to fracture union and complications, including vitamin D toxicity. Outcomes included union, nonunion or complication requiring an early, unplanned secondary procedure. Patients without an outcome at 15 months and no scheduled follow-up were considered lost to follow-up. The t-test and cross tabulations verified the adequacy of randomisation. An intention-to-treat analysis was carried out. RESULTS: In all, 100 (89%) patients had hypovitaminosis D. Both treatment and control groups had similar demographics and injury characteristics. The initial median vitamin D levels were 16 ng/mL (interquartile range 5 to 28) in both groups (p = 0.885). A total of 14 patients were lost to follow-up (seven from each group), two had fixation failure (one in each group) and one control group patient developed an infection. Overall, the nonunion rate was 4% (two per group). No patient showed signs of clinical toxicity from their supplement. CONCLUSIONS: Despite finding a high level of hypovitaminosis D, the rate of union was high and independent of supplementation with vitamin D3. Cite this article: Bone Joint J 2017;99-B:1520-5.

Technical considerations to avoid delayed and non-union.

For many years intramedullary nails have been a well accepted and successful method of diaphyseal fracture fixation. However, delayed and non unions with this technique do still occur and are associated with significant patient morbidity. The reason for this can be multi-factorial. We discuss a number of technical considerations to maximise fracture reduction, fracture stability and fracture vascularity in order to achieve bony union.

When Is a Fracture Not "Fresh"? Aligning Reimbursement With Patient Outcome After Treatment With Low-Intensity Pulsed Ultrasound.

OBJECTIVE: The clinical value of low-intensity pulsed ultrasound (LIPUS) for fresh fracture is known. Yet, in the absence of a definition of what "fresh" is, payers have adopted study inclusion criteria drawn from randomized clinical trials as de facto definitions of which patients should be treated, with "fresh" defined as <1 week old. Patients with fracture may thus be ineligible for LIPUS treatment after week 1, which potentially denies access to patients who could benefit from LIPUS. We seek to characterize the inflection point at which heal rate declines. DESIGN: Prospective cohort. SETTING: Food and Drug Administration-mandated nationwide postmarketing surveillance registry. PATIENTS: Observational cohort of 5983 registry enrollees. INTERVENTION: LIPUS, 20 min/d. MAIN OUTCOME MEASURE: Fracture heal rate. Logistic regression was used to model the odds ratio of nonunion from week 1 to week 12. Covariates in the model included age, gender, body mass index, open fracture, and smoking. RESULTS: We estimated the time point at which a fracture responds to LIPUS as well as during the first week after fracture. There was significant bone-to-bone variation; metatarsal was "fresh" until week 7, ankle until week 9, humerus until week 10, and femur and radius until week 12. Healing was significantly impacted by patient age, body mass index, and open fracture (all, P ≤ 0.02). CONCLUSIONS: Our results suggest that fractures of the metatarsal, femur, humerus, ankle, and radius respond to LIPUS treatment, as if they were still fresh at least 6 weeks longer than the eligibility allowed under current coverage policies. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Metformin Prevents Nonunion after Three-Cannulated-Screw Fixation in Displaced Femoral Neck Fractures: A Retrospective Study.

Patients aged from 40 to 60 with displaced fractures of the femoral neck (Garden III or IV) who received fixation with three cannulated screws from January 2005 to December 2012 were evaluated retrospectively for the development of nonunion. Plasma HbA1C, a marker for long-term plasma glucose level, anti-T2DM medication, and other potential risk factors were recorded for the purpose of this study. There were no differences between the union and nonunion groups with respect to age, gender, Garden classification, Pauwel's angle, reduction quality, and T2DM presence. There were significant differences in reduction quality and preoperative plasma HbA1C level between patients with and those without union. The odds ratio (OR) for fracture nonunion was 2.659 (95% confidence interval [CI], 1.530-4.620) in subjects with anatomical reduction compared with those without anatomical reduction, 4.797 (95% CI, 1.371-16.778), in subjects with poor blood glucose control (HbA1C > 10%). The metformin usage showed a preventive effect on nonunion development (OR: 0.193 and CI: 0.060-0.616). The nonunion rate of metformin group (6.7%, 6/89) was even much lower than that of patients without T2DM (17.4%, 80/460).

Injectable Recombinant Human Platelet-derived Growth Factor in Collagen Carrier for Hindfoot Fusion.

Arthrodesis of the hindfoot is a common procedure for degenerative joint disease and/or severe deformity. Nonunion is a common complication from this procedure, causing an increased burden to the patient and health care system, often resulting in the need for revision surgery. Recombinant human platelet-derived growth factor (rhPDGF) has been shown to be a safe and effective tool to enhance arthrodesis rates in hindfoot surgery while avoiding the potential morbidity of bone grafting. This article provides a review of the role of rhPDGF in hindfoot fusions, and the surgical technique for performing an rhPDGF enhanced double-arthrodesis through a medial approach.

Role of Recombinant Human Bone Morphogenetic Protein-2 on Hindfoot Arthrodesis.

Despite advances in understanding bone healing physiology and surgical techniques, delayed union and nonunion still occur after the treatment of hindfoot arthrodesis. There is increasing appeal of bone morphogenetic proteins (BMPs) owing to the innate osteoinductive abilities of BMPs. Effective treatment with BMPs has been shown in animal studies. Human clinical studies have also shown success. The only study investigating the use of recombinant human BMP (rhBMP)-2 in hindfoot arthrodesis found a significant increase in fusion rate. Treatment cost effective. Complications from their use remain low. rhBMP-2 is a safe and effective bone-healing adjunct in hindfoot arthrodesis surgery.

[Fractures of carpal bones]. / Frakturen der Handwurzelknochen.

Fractures of the carpal bones are uncommon. On standard radiographs fractures are often not recognized and a computed tomography (CT) scan is the diagnostic method of choice. The aim of treatment is to restore pain-free and full functioning of the hand. A distinction is made between stable and unstable carpal fractures. Stable non-displaced fractures can be treated conservatively. Unstable and displaced fractures have an increased risk of arthritis and non-union and should be stabilized by screws or k­wires. If treated adequately, fractures of the carpal bones have a good prognosis. Unstable and dislocated fractures have an increased risk for non-union. The subsequent development of carpal collapse with arthrosis is a severe consequence of non-union, which has a heterogeneous prognosis.

Fixation of displaced femoral neck fractures in young adults: Fixed-angle devices or Pauwel screws?

BACKGROUND: We sought to compare the incidence of complications after fixation of displaced femoral neck fractures in young adults treated with fixed-angle devices versus multiple cancellous screws and a trochanteric lag screw (Pauwel screw). METHODS: We conducted a retrospective cohort study at a level I trauma centre. Sixty-two skeletally mature patients (age range, 16-60 years) with displaced femoral neck fractures were included in the study. Forty-seven were treated with a fixed-angle device (sliding hip plate with screw or helical blade) and 15 with multiple cancellous screws placed in a Pauwel configuration. The main outcome measure was postoperative complication of osteonecrosis or nonunion treated with a surgical procedure. RESULTS: Significantly fewer failures occurred in the fixed-angle group (21%) than in the screws group (60%) (p=0.008). Osteonecrosis was rare in the fixed-angle group, occurring in 2% of cases versus 33% of cases in the screws group (p=0.002). Consistent with previous studies, good to excellent reductions were associated with a failure rate of 25% and fair to poor reductions were associated with a failure rate of 55% (p=0.07). The best-case scenario of a good to excellent reduction stabilised with a fixed-angle device yielded a success rate of 85%. CONCLUSION: In young patients with displaced high-energy femoral neck fractures, fixed-angle devices resulted in fewer treatment failures than did Pauwel screws.