Validation of forearm fracture diagnoses in administrative patient registers.

The validity of forearm fracture diagnoses recorded in five Norwegian hospitals was investigated using image reports and medical records as gold standard. A relatively high completeness and correctness of the diagnoses was found. Algorithms used to define forearm fractures in administrative data should depend on study purpose. PURPOSE: In Norway, forearm fractures are routinely recorded in the Norwegian Patient Registry (NPR). However, these data have not been validated. Data from patient administrative systems (PAS) at hospitals are sent unabridged to NPR. By using data from PAS, we aimed to examine (1) the validity of the forearm fracture diagnoses and (2) the usefulness of washout periods, follow-up codes, and procedure codes to define incident forearm fracture cases. METHODS: This hospital-based validation study included women and men aged ≥ 19 years referred to five hospitals for treatment of a forearm fracture during selected periods in 2015. Administrative data for the ICD-10 forearm fracture code S52 (with all subgroups) in PAS and the medical records were reviewed. X-ray and computed tomography (CT) reports from examinations of forearms were reviewed independently and linked to the data from PAS. Sensitivity and positive predictive values (PPVs) were calculated using image reports and/or review of medical records as gold standard. RESULTS: Among the 8482 reviewed image reports and medical records, 624 patients were identified with an incident forearm fracture during the study period. The sensitivity of PAS registrations was 90.4% (95% CI: 87.8-92.6). The PPV increased from 73.9% (95% CI: 70.6-77.0) in crude data to 90.5% (95% CI: 88.0-92.7) when using a washout period of 6 months. Using procedure codes and follow-up codes in addition to 6-months washout increased the PPV to 94.0%, but the sensitivity fell to 69.0%. CONCLUSION: A relatively high sensitivity of forearm fracture diagnoses was found in PAS. PPV varied depending on the algorithms used to define cases. Choice of algorithm should therefore depend on study purposes. The results give useful measures of forearm fracture diagnoses from administrative patient registers. Depending on local coding practices and treatment pathways, we infer that the findings are relevant to other fracture diagnoses and registers.

Trochanteric stabilizing plate in the treatment of trochanteric fractures: a scoping review.

Background and purpose - The trochanteric stabilizing plate (TSP) may be used as an adjunct to a sliding hip screw (SHS) in the treatment of trochanteric fractures to increase construct stability. We performed a scoping review of the literature to clarify when and how the TSP may be useful.Methods - A systematic search was performed in 5 databases and followed by a backwards-and-forwards citation search of the identified papers. 24 studies were included.Results - 6 biomechanical studies and 18 clinical studies were included in the review. The studies presented mainly low-level evidence. All studies were on unstable trochanteric fractures or fracture models. Due to the heterogeneity of methods and reporting, we were not able to perform a meta-analysis. In the biomechanical trials, the TSP appeared to increase stability compared with SHS alone, up to a level comparable with intramedullary nails (IMNs). We identified 1,091 clinical cases in the literature where a TSP had been used. There were 82 (8%) reoperations. The rate of complications and reoperations for SHS plus TSP was similar to previous reports on SHS alone and IMN. It was not possible to conclude whether the TSP gave better clinical results, when compared with either SHS alone or with IMN.Interpretation - The heterogeneity of methods and reporting precluded any clear recommendations on when to use the TSP, or if it should be used at all.

Evidence of impaired bone quality in men with type 1 diabetes: a cross-sectional study.

OBJECTIVE: Type 1 diabetes (T1D) is associated with substantial fracture risk. Bone mineral density (BMD) is, however, only modestly reduced, suggesting impaired bone microarchitecture and/or bone material properties. Yet, the skeletal abnormalities have not been uncovered. Men with T1D seem to experience a more pronounced bone loss than their female counterparts. Hence, we aimed to examine different aspects of bone quality in men with T1D. DESIGN AND METHODS: In this cross-sectional study, men with T1D and healthy male controls were enrolled. BMD (femoral neck, total hip, lumbar spine, whole body) and spine trabecular bone score (TBS) were measured by dual x-ray absorptiometry, and bone material strength index (BMSi) was measured by in vivo impact microindentation. HbA1c and bone turnover markers were analyzed. RESULTS: Altogether, 33 men with T1D (43 ± 12 years) and 28 healthy male controls (42 ± 12 years) were included. Subjects with T1D exhibited lower whole-body BMD than controls (P = 0.04). TBS and BMSi were attenuated in men with T1D vs controls (P = 0.016 and P = 0.004, respectively), and T1D subjects also had a lower bone turnover. The bone parameters did not differ between subjects with or without diabetic complications. Duration of disease correlated negatively with femoral neck BMD but not with TBS or BMSi. CONCLUSIONS: This study revealed compromised bone material strength and microarchitecture in men with T1D. Moreover, our data confirm previous studies which found a modest decrease in BMD and low bone turnover in subjects with T1D. Accordingly, bone should be recognized as a target of diabetic complications.

Health care services and costs after hip fracture, comparing conventional versus standardised care: A retrospective study with 12-month follow-up.

AIMS: To compare costs related to a standardised versus conventional hospital care for older patients after fragility hip fracture and determine whether a shift in hospital care led to cost-shifts between specialists and primary health care. METHODS: We retrospectively collected and calculated volumes of care and accompanying costs from fracture time until 12 months after hospital discharge for 979 patients. All patients aged ≥ 65 years had fragility hip fractures. The data set had few missing data points because of the patient registry, administrative databases, and a low migration rate. RESULTS: Total costs per patient at 12 months were EUR 78 164 (standard deviation [SD] 58 056) and EUR 78 068 (SD 60 131) for conventional and standardised care, respectively (p = 0.480). Total specialist care costs were significantly lower for the standardised care group (p < 0.001). Total primary care costs were higher for the standardised care group (p = 0.424). Total costs per day of life for the conventional and standardised care groups were EUR 434 and EUR 371, respectively (p = 0.003). Patients in the standardised care group had 17 more days of life. CONCLUSIONS: Implementation of a standardised care to improve outcomes for patients with hip fracture caused lower specialist care costs and higher primary care costs, indicating care- and cost-shifts from specialist to primary health care.

Virus transmission during orthopedic surgery on patients with COVID-19 - a brief narrative review.

Background and purpose - COVID-19 is among the most impactful pandemics that the society has experienced. Orthopedic surgery involves procedures generating droplets and aerosols and there is concern amongst surgeons that otherwise rational precautionary principles are being set aside due to lack of scientific evidence and a shortage of personal protective equipment (PPE). This narrative review attempts to translate relevant knowledge into practical recommendations for healthcare workers involved in orthopedic surgery on patients with known or suspected COVID-19.Patients and methods - We unsystematically searched in PubMed, reference lists, and the WHO's web page for relevant publications concerning problems associated with the PPE used in perioperative practice when a patient is COVID-19 positive or suspected to be. A specific search for literature regarding COVID-19 was extended to include publications from the SARS epidemic in 2002/3.Results - Transmission of infectious viruses from patient to surgeon during surgery is possible, but does not appear to be a considerable problem in clinical practice. Seal-leakage is a problem with surgical masks. Due to the lack of studies and reports, the possibility of transmission of SARS-CoV-2 from patient to surgeon during droplet- and aerosol-generating procedures is unknown.Interpretation - Surgical masks should be used only in combination with a widely covering visor and when a respirator (N95, FFP2, P3) is not made available. Furthermore, basic measures to reduce shedding of droplets and aerosols during surgery and correct and consistent use of personal protective equipment is important.

Preventing spread of SARS-CoV-2 and preparing for the COVID-19 outbreak in the surgical department: perspectives from two Scandinavian countries.

A COVID-19 pandemic was declared on March 11 by the World Health Organization (WHO). The first cases of COVID-19 were confirmed on January 31 in Sweden and on February 26 in Norway. Despite being similar countries with universal healthcare systems, the governmental approaches to mitigation of the epidemic have varied considerably. Norway initiated a societal lockdown effective from March 12, the same day as the first confirmed death. Sweden has initiated a more laxed and gradual strategy based on the appeal for a strong personal sense of responsibility to mitigate the viral spread. In both countries, the first weeks of preparation has seen a strong reduction in elective surgery, with several implemented principles to mitigate SARS-CoV-2 spread and prepare for surgical care for COVID-19 diseases as needed. This invited leading article gives a brief overview of some of the early experiences of the outbreak in two Scandinavian countries.

Post-fracture Risk Assessment: Target the Centrally Sited Fractures First! A Substudy of NoFRACT.

The location of osteoporotic fragility fractures adds crucial information to post-fracture risk estimation. Triaging patients according to fracture site for secondary fracture prevention can therefore be of interest to prioritize patients considering the high imminent fracture risk. The objectives of this cross-sectional study were therefore to explore potential differences between central (vertebral, hip, proximal humerus, pelvis) and peripheral (forearm, ankle, other) fractures. This substudy of the Norwegian Capture the Fracture Initiative (NoFRACT) included 495 women and 119 men ≥50 years with fragility fractures. They had bone mineral density (BMD) of the femoral neck, total hip, and lumbar spine assessed using dual-energy X-ray absorptiometry (DXA), trabecular bone score (TBS) calculated, concomitantly vertebral fracture assessment (VFA) with semiquantitative grading of vertebral fractures (SQ1-SQ3), and a questionnaire concerning risk factors for fractures was answered. Patients with central fractures exhibited lower BMD of the femoral neck (765 versus 827 mg/cm2 ), total hip (800 versus 876 mg/cm2 ), and lumbar spine (1024 versus 1062 mg/cm2 ); lower mean TBS (1.24 versus 1.28); and a higher proportion of SQ1-SQ3 fractures (52.0% versus 27.7%), SQ2-SQ3 fractures (36.8% versus 13.4%), and SQ3 fractures (21.5% versus 2.2%) than patients with peripheral fractures (all p < 0.05). All analyses were adjusted for sex, age, and body mass index (BMI); and the analyses of TBS and SQ1-SQ3 fracture prevalence was additionally adjusted for BMD). In conclusion, patients with central fragility fractures revealed lower femoral neck BMD, lower TBS, and higher prevalence of vertebral fractures on VFA than the patients with peripheral fractures. This suggests that patients with central fragility fractures exhibit more severe deterioration of bone structure, translating into a higher risk of subsequent fragility fractures and therefore they should get the highest priority in secondary fracture prevention, although attention to peripheral fractures should still not be diminished. © 2019 American Society for Bone and Mineral Research. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Endoscopic Treatment of Greater Trochanteric Pain Syndrome - A Case Series of 11 Patients.

INTRODUCTION: Greater trochanteric pain syndrome (GTPS) includes patients with symptoms of peritrochanteric pain, gluteus medius/minimus tendinopathy, and external snapping hip. Non-operative treatment includes iliotibial band (ITB) stretching, gluteal exercises and cortisone injections. When surgery is indicated due to the failure of non-operative strategies, open Z-plasty at the level of the greater trochanter has been the traditional procedure. Endoscopic release of the ITB and bursectomy at the level of the greater trochanter has over the last decades evolved and is established as an alternative method of surgery. CASE REPORTS: We here present a case series with 11 consecutive patients who have undergone endoscopic release of the ITB and bursectomy at the level of the greater trochanter due to GTPS. The patients were all Caucasians, 43-years of age, and six were female. The patients retrospectively scored their pre-operative function and pain during follow-up at 28 months (range 15-42). Post-operative pain and function were scored at follow-up. In this paper, we discuss investigation, differential diagnoses, surgical options, and outcomes in the treatment of GTPS. All patients reported significant reduction of pain, and 10 of 11 patients reported an improvement in function. We observed no complications. CONCLUSIONS: Endoscopic release of the ITB and bursectomy at the level of the greater trochanter appears to be an effective and safe procedure when conservative treatment options for GTPS have failed.

High prevalence of vertebral fractures and low trabecular bone score in patients with fragility fractures: A cross-sectional sub-study of NoFRACT.

PURPOSE: Norway has among the highest incidence rates of fractures in the world. Vertebral fracture assessment (VFA) and trabecular bone score (TBS) provide information about fracture risk, but their importance have not been studied in Norwegian patients with fragility fractures. The objectives of this study were to examine the clinical characteristics of a cohort of women and men with fragility fractures, their prevalence of vertebral fractures using VFA and prevalence of low TBS, and explore the differences between the sexes and patients with and without vertebral fractures. METHODS: This cross-sectional sub-study of the Norwegian Capture the Fracture Initiative (NoFRACT) included 839 patients with fragility fractures. Of these, 804 patients had bone mineral density (BMD) of the total hip, femoral neck and/or spine assessed using dual energy x-ray absorptiometry, 679 underwent concomitant VFA, 771 had TBS calculated and 696 responded to a questionnaire. RESULTS: Mean age was 65.8 (SD 8.8) years and 80.5% were women. VFA revealed vertebral fractures in 34.8% of the patients and 34.0% had low TBS (≤ 1.23), with no differences between the sexes. In all patients with valid measures of both VFA and TBS, 53.8% had either vertebral fractures, low TBS, or both. In the patients with osteopenia at the femoral neck, 53.6% had either vertebral fractures, low TBS, or both. Femoral neck BMD T-score ≤ -2.5 was found in 13.8% of all patients, whereas the corresponding figure was 27.4% using the skeletal site with lowest T-score. Women exhibited lower BMD at all sites and lower TBS than men (1.27 vs. 1.29), (all p < 0.05). Patients with prevalent vertebral fractures were older (69.4 vs. 64.0 years), exhibited lower BMD at all sites and lower TBS (1.25 vs.1.29) than those without vertebral fractures (all p < 0.05). Before assessment, 8.2% were taking anti-osteoporotic drugs (AOD), and after assessment, the prescription rate increased to 56.2%. CONCLUSIONS: More than half of the patients with fragility fractures had vertebral fractures, low TBS or both. The prescription of AOD increased seven fold from before assessment to after assessment, emphasizing the importance of risk assessment after a fragility fracture.

Effect of a Fracture Liaison Service on the Rate of Subsequent Fracture Among Patients With a Fragility Fracture in the Norwegian Capture the Fracture Initiative (NoFRACT): A Trial Protocol.

Importance: Fragility fracture is a major health issue because of the accompanying morbidity, mortality, and financial cost. Despite the high cost to society and personal cost to affected individuals, secondary fracture prevention is suboptimal in Norway, mainly because most patients with osteoporotic fractures do not receive treatment with antiosteoporotic drugs after fracture repair. Objectives: To improve secondary fracture prevention by introducing a standardized intervention program and to investigate the effect of the program on the rate of subsequent fractures. Design, Setting, and Participants: Trial protocol of the Norwegian Capture the Fracture Initiative (NoFRACT), an ongoing, stepped wedge cluster randomized clinical trial in 7 hospitals in Norway. The participating hospitals were cluster randomized to an intervention starting date: May 1, 2015; September 1, 2015; and January 1, 2016. Follow-up is through December 31, 2019. The outcome data were merged from national registries of women and men 50 years and older with a recent fragility fracture treated at 1 of the 7 hospitals. Discussion: The NoFRACT trial is intended to enroll 82 000 patients (intervention period, 26 000 patients; control period, 56 000 patients), of whom 23 578 are currently enrolled by January 2018. Interventions include a standardized program for identification, assessment, and treatment of osteoporosis in patients with a fragility fracture that is led by a trained coordinating nurse. The primary outcome is rate of subsequent fracture (per 10 000 person-years) based on national registry data. Outcomes before (2008-2015; control period) and after (2015-2019; intervention period) the intervention will be compared, and each hospital will act as its own control. Use of outcomes from national registry data means that all patients are included in the analysis regardless of whether they are exposed to the intervention (intention to treat). A sensitivity analysis with a transition window will be performed to mitigate possible within-cluster contamination. Results: Results are planned to be disseminated through publications in peer-reviewed journals and presented at local, national, and international conferences. Conclusions: By introducing a standardized intervention program for assessment and treatment of osteoporosis in patients with fragility fractures, we expect to document reduced rates of subsequent fractures and fracture-related mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02536898.

Mortality and readmission following hip fracture surgery: a retrospective study comparing conventional and fast-track care.

OBJECTIVE: To compare the efficacies of two pathways-conventional and fast-track care-in patients with hip fracture. DESIGN: Retrospective single-centre study. SETTING: University hospital in middle Norway. PARTICIPANTS: 1820 patients aged ≥65 years with hip fracture (intracapsular, intertrochanteric or subtrochanteric). INTERVENTIONS: 788 patients were treated according to conventional care from April 2008 to September 2011, and 1032 patients were treated according to fast-track care from October 2011 to December 2013. PRIMARY AND SECONDARY OUTCOME: Primary: mortality and readmission to hospital, within 365 days follow-up. Secondary: length of stay. RESULTS: We found no statistically significant differences in mortality and readmission rate between patients in the fast-track and conventional care models within 365 days after the initial hospital admission. The conventional care group had a higher, no statistical significant mortality HR of 1.10 (95% CI 0.91 to 1.31, p=0.326) without and 1.16 (95% CI 0.96 to 1.40, p=0.118) with covariate adjustment. Regarding the readmission, the conventional care group sub-HR was 1.02 (95% CI 0.88 to 1.18, p=0.822) without and 0.97 (95% CI 0.83 to 1.12, p=0.644) with adjusting for covariates. Length of stay and time to surgery was statistically significant shorter for patients who received fast-track care, a mean difference of 3.4 days and 6 hours, respectively. There was no statistically significant difference in sex, type of fracture, age or Charlson Comorbidity Index score at baseline between patients in the two pathways. CONCLUSIONS: There was insufficient evidence to show an impact of fast-track care on mortality and readmission. Length of stay and time to surgery were decreased. TRIAL REGISTRATION NUMBER: NCT00667914; results.

Reoperations and mortality in 383 patients operated with parallel screws for Garden I-II femoral neck fractures with up to ten years follow-up.

INTRODUCTION: The objective of this study was to identify indications and predictors for subsequent surgeries in the same hip and to evaluate life expectancy following screw fixation of undisplaced femoral neck fractures (FNF). The study further aimed to determine the necessary follow-up time for future studies aiming to evaluate the treatment of such fractures. MATERIALS AND METHODS: This is a single-center retrospective cohort study with prospectively collected data including skeletally mature patients with undisplaced FNFs operated between 2005 and 2013. Gender, age at fracture, American Society of Anesthesiologists score, smoking status and excess use of alcohol were retrieved from electronical medical records. Further, complications leading to all consecutive reoperations were registered along with time from primary operation to all reoperations, type of procedure during subsequent surgeries and time of death. RESULTS: 383 patients with a median (range) follow-up of 77 (23-125) months were identified. Within 1, 2 and 5 years from primary surgery, 8%, 17% and 21% respectively, had at least one subsequent surgery in the same hip. 10% of the patients underwent salvage arthroplasty, however, in long time survivors; conversion to arthroplasty was estimated in one out of four. Posterior tilt of the femoral head was a predictor for new surgeries due to instability of the bone-implant construct, but not for later avascular necrosis. For patients 70 years or older, the one-year mortality in men was 32% with an expected survival of approx. 2.5 years, compared to 17% and 5.5 years in women. CONCLUSIONS: Screw fixation of undisplaced femoral neck fractures appears to be a safe procedure in particular in the absence of a posterior tilt of the femoral head. Conversion to arthroplasty was estimated to occur in one out of four of long time survivors. Men have a particularly poor medical prognosis and should receive careful medical attention. In order to capture 80% of reoperations, clinical studies and register studies must have a follow-up time of at least two years.

Impaired skeletal health in patients with chronic atrophic gastritis.

OBJECTIVE: In chronic atrophic gastritis (CAG), destruction of gastric parietal cells causes anacidity and hypergastrinemia. Use of proton pump inhibitors, which also induces gastric anacidity, is associated with increased fracture rates. Our objectives were to study possible differences in bone mineral density (BMD) and bone quality in patients with CAG compared to controls. MATERIAL AND METHODS: We performed a cross-sectional study on 17 CAG patients aged 54 ± 13 years and 41 sex- and age-matched controls. Lumbar and femoral BMD and bone quality assessed by lumbar trabecular bone score (TBS) were measured by DXA, and bone material strength (BMS) by microindentation of the tibia. Serum bone markers (CTX, P1NP, sclerostin, osteocalcin, OPG, RANKL) were analyzed. RESULTS: We found lower lumbar BMD Z-score (-0.324 ± 1.096 versus 0.456 ± 1.262, p = 0.030), as well as a higher frequency of osteoporosis at the lumbar spine (p = 0.046) and osteopenia at total hip (p = 0.019) in patients compared to controls. In a post hoc subgroup analysis, we observed that the differences were confined to the male patients. TBS also tended to be lower in male patients (p = 0.059), while BMS did not differ between the groups. Osteocalcin, sclerostin, OPG, and OPG/RANKL ratio were lower in patients compared to controls, while CTX and P1NP did not differ between the groups. CONCLUSIONS: We observed lower lumbar BMD, increased frequency of osteopenia and osteoporosis in male, but not female patients with CAG. Bone markers suggest a decrease in bone formation and increased bone resorption in CAG patients compared to controls.

A biomechanical comparison of composite femurs and cadaver femurs used in experiments on operated hip fractures.

Fourth generation composite femurs (4GCFs, models #3406 and #3403) simulate femurs of males <80 years with good bone quality. Since most hip fractures occur in old women with fragile bones, concern is raised regarding the use of standard 4GCFs in biomechanical experiments. In this study the stability of hip fracture fixations in 4GCFs was compared to human cadaver femurs (HCFs) selected to represent patients with hip fractures. Ten 4GCFs (Sawbones, Pacific Research Laboratories, Inc., Vashon, WA, USA) were compared to 24 HCFs from seven females and five males >60 years. Proximal femur anthropometric measurements were noted. Strain gauge rosettes were attached and femurs were mounted in a hip simulator applying a combined subject-specific axial load and torque. Baseline measurements of resistance to deformation were recorded. Standardized femoral neck fractures were surgically stabilized before the constructs were subjected to 20,000 load-cycles. An optical motion tracking system measured relative movements. Median (95% CI) head fragment migration was 0.8mm (0.4 to 1.1) in the 4GCF group versus 2.2mm (1.5 to 4.6) in the cadaver group (p=0.001). This difference in fracture stability could not be explained by observed differences in femoral anthropometry or potential overloading of 4GCFs. 4GCFs failed with fracture-patterns different from those observed in cadavers. To conclude, standard 4GCFs provide unrealistically stable bone-implant constructs and fail with fractures not observed in cadavers. Until a validated osteopenic or osteoporotic composite femur model is provided, standard 4GCFs should only be used when representing the biomechanical properties of young healthy femurs.

Locking plates and their effects on healing conditions and stress distribution: A femoral neck fracture study in cadavers.

BACKGROUND: Implants are used to stabilize femoral neck fractures to achieve successful fracture healing, but there is still a high rate of fracture non-unions. We compared micromotions in femurs with fractured femoral necks stabilized with three screws with or without a locking plate. We also investigated whether osteoporosis was associated with micromotion magnitudes, and explored the influence of implants on load distribution in the upper femur. METHODS: Twelve pairs of human cadaver femurs with femoral neck fractures (AO/OTA 31-B1) were allocated to fracture fixation by three locked screws or three individual screws. All femurs underwent dual energy X-ray absorptiometry. Physiological subject-specific axial load and torque was applied for 10,000cycles. Micromotion of the head fragment was measured every 100cycles with high-resolution optical motion detection. Load distribution was measured with strain-gauge rosettes attached to the lateral and medial proximal diaphysis. FINDINGS: The locking plate group showed reduced micromotion about the femoral neck axis (P=0.035, effect size=0.62). No differences were found in valgus-varus or antegrade-retrograde rotations, or in the three translations. Micromotion magnitudes were not associated with osteoporosis. The overall micromotions of the upper femur and the load distribution in the proximal diaphysis were not influenced by fixation type. INTERPRETATION: The locking plate group showed increased resistance to shear forces compared with the screw group. This effect was not associated with a diagnosis of osteoporosis. The locking plate did not affect the load distribution in the proximal femur.

The effect of interlocking parallel screws in subcapital femoral-neck fracture fixation: a cadaver study.

BACKGROUND: A new locking-plate for femoral-neck fractures that provides angular stability to three screws in an inverted triangle configuration was evaluated. The plate is not fixed to the lateral cortex and therefore represents a new treatment principle. METHODS: Twelve pairs of cadaver femurs (mean T-score -1,95 (range -4,5-0)) with subcapital femoral-neck fractures angulating 60° were randomly allocated to fracture-fixation using either three individual screws or three interlocked screws. Subject-specific axial force and torque were applied by a hip simulator and three-dimensional migrations were recorded. The femurs underwent 10,000 cycles of simulated partial weight-bearing, followed by 10,000 cycles of simulated full weight-bearing and stair climbing. FINDINGS: On average interlocking reduced femoral-head centre migrations 1.6mm (95% CI 0.1-3.1, P = 0.04). The intra-pair correlation of migration was 0.953 (Pearson's r). Interlocking did not change rotational stability (P = 0.87). Adding a locking plate did not affect the risk of failure, however all failed femurs were fixed using the smallest-sized aiming guide. INTERPRETATIONS: Adding a lateral interlocking plate to three screws might improve the fracture stability. However, none of the implants were able to resist the unwanted deformation of the proximal femur. Regardless of the fixation, female sex, reduced bone quality and small sized femurs appear to increase risk of failure.

Biomechanical femoral neck fracture experiments--a narrative review.

INTRODUCTION: Orthopaedic implants can be introduced in clinical practice if equivalency to an already approved implant can be demonstrated. A preclinical laboratory test can in theory provide the required evidence. Due to the lack of consensus on the optimum design of biomechanical experiments, setups vary considerably. This review aims to make femoral neck fracture models more accessible for evaluation to orthopaedic surgeons without any particular background in biomechanics. Additionally, the clinical relevance of the different setups is discussed. METHODS: This is a narrative review based on a non-systematic search in PubMed, Scopus and Cochrane. SUMMARY: Biomechanical femoral neck fracture experiments should aim at optimizing the recreation of the in vivo situation. The bone quality of the experimental femurs should resemble the hip fracture population, hence cadaveric bones should be preferred to the available synthetic replica. The fracture geometry must be carefully selected to avoid bias. The load applied to the specimen should result in forces within the range of in vivo measured values and the magnitude should be related to the actual weight of the donor. A well designed biomechanical experiment can prevent harmful devices from being introduced in clinical practice, however, positive results can never exclude the necessity of subsequent clinical studies.