Identifying 'avoidable harm' in family practice: a RAND/UCLA Appropriateness Method consensus study

Background

Health care-related harm is an internationally recognized threat to public health. The United Kingdom’s national health services demonstrate that upwards of 90% of health care encounters can be delivered in ambulatory settings. Other countries are transitioning to more family practice-based health care systems, and efforts to understand avoidable harm in these settings is needed.

Methods

We developed 100 scenarios reflecting a range of diseases and informed by the World Health Organization definition of ‘significant harm’. Scenarios included different types of patient safety incidents occurring by commission and omission, demonstrated variation in timeliness of intervention, and conditions where evidence-based guidelines are available or absent. We conducted a two-round RAND / UCLA Appropriateness Method consensus study with a panel of family practitioners in England to define “avoidable harm” within family practice. Panelists rated their perceptions of avoidability for each scenario. We ran a k-means cluster analysis of avoidability ratings.

Results

Panelists reached consensus for 95 out of 100 scenarios. The panel agreed avoidable harm occurs when a patient safety incident could have been probably, or totally, avoided by the timely intervention of a health care professional in family practice (e.g. investigations, treatment) and / or an administrative process (e.g. referrals, alerts in electronic health records, procedures for following up results) in accordance with accepted evidence-based practice and clinical governance. Fifty-four scenarios were deemed avoidable, whilst 31 scenarios were rated unavoidable and reflected outcomes deemed inevitable regardless of family practice intervention. Scenarios with low avoidability ratings (1 s or 2 s) were not represented by the categories that were used to generate scenarios, whereas scenarios with high avoidability ratings (7 s 8 s or 9 s) were represented by these a priori categories.

Discussion

The findings from this RAND/UCLA Appropriateness Method study define the characteristics and conditions that can be used to standardize measurement of outcomes for primary care patient safety.

Conclusion

We have developed a definition of avoidable harm that has potential for researchers and practitioners to apply across primary care settings, and bolster international efforts to design interventions to target avoidable patient safety incidents that cause the most significant harm to patients.

Electronic supplementary material

The online version of this article (10.1186/s12875-019-0990-z) contains supplementary material, which is available to authorized users.

Clinical effectiveness and cost-effectiveness of issuing longer versus shorter duration (3-month vs. 28-day) prescriptions in patients with chronic conditions: systematic review and economic modelling

BACKGROUND

To reduce expenditure on, and wastage of, drugs, some commissioners have encouraged general practitioners to issue shorter prescriptions, typically 28 days in length; however, the evidence base for this recommendation is uncertain.

OBJECTIVE

To evaluate the evidence of the clinical effectiveness and cost-effectiveness of shorter versus longer prescriptions for people with stable chronic conditions treated in primary care.

DESIGN/DATA SOURCES

The design of the study comprised three elements. First, a systematic review comparing 28-day prescriptions with longer prescriptions in patients with chronic conditions treated in primary care, evaluating any relevant clinical outcomes, adherence to treatment, costs and cost-effectiveness. Databases searched included MEDLINE (PubMed), EMBASE, Cumulative Index to Nursing and Allied Health Literature, Web of Science and Cochrane Central Register of Controlled Trials. Searches were from database inception to October 2015 (updated search to June 2016 in PubMed). Second, a cost analysis of medication wastage associated with < 60-day and ≥ 60-day prescriptions for five patient cohorts over an 11-year period from the Clinical Practice Research Datalink. Third, a decision model adapting three existing models to predict costs and effects of differing adherence levels associated with 28-day versus 3-month prescriptions in three clinical scenarios.

REVIEW METHODS

In the systematic review, from 15,257 unique citations, 54 full-text papers were reviewed and 16 studies were included, five of which were abstracts and one of which was an extended conference abstract. None was a randomised controlled trial: 11 were retrospective cohort studies, three were cross-sectional surveys and two were cost studies. No information on health outcomes was available.

RESULTS

An exploratory meta-analysis based on six retrospective cohort studies suggested that lower adherence was associated with 28-day prescriptions (standardised mean difference -0.45, 95% confidence interval -0.65 to -0.26). The cost analysis showed that a statistically significant increase in medication waste was associated with longer prescription lengths. However, when accounting for dispensing fees and prescriber time, longer prescriptions were found to be cost saving compared with shorter prescriptions. Prescriber time was the largest component of the calculated cost savings to the NHS. The decision modelling suggested that, in all three clinical scenarios, longer prescription lengths were associated with lower costs and higher quality-adjusted life-years.

LIMITATIONS

The available evidence was found to be at a moderate to serious risk of bias. All of the studies were conducted in the USA, which was a cause for concern in terms of generalisability to the UK. No evidence of the direct impact of prescription length on health outcomes was found. The cost study could investigate prescriptions issued only; it could not assess patient adherence to those prescriptions. Additionally, the cost study was based on products issued only and did not account for underlying patient diagnoses. A lack of good-quality evidence affected our decision modelling strategy.

CONCLUSIONS

Although the quality of the evidence was poor, this study found that longer prescriptions may be less costly overall, and may be associated with better adherence than 28-day prescriptions in patients with chronic conditions being treated in primary care.

FUTURE WORK

There is a need to more reliably evaluate the impact of differing prescription lengths on adherence, on patient health outcomes and on total costs to the NHS. The priority should be to identify patients with particular conditions or characteristics who should receive shorter or longer prescriptions. To determine the need for any further research, an expected value of perfect information analysis should be performed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015027042.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Donaldson L, Carson-Stevens A. Sources of unsafe primary care for older adults: a mixed-methods analysis of patient safety incident reports

Background

older adults are frequent users of primary healthcare services, but are at increased risk of healthcare-related harm in this setting.

Objectives

to describe the factors associated with actual or potential harm to patients aged 65 years and older, treated in primary care, to identify action to produce safer care.

Design and Setting

a cross-sectional mixed-methods analysis of a national (England and Wales) database of patient safety incident reports from 2005 to 2013.

Subjects

1,591 primary care patient safety incident reports regarding patients aged 65 years and older.

Methods

we developed a classification system for the analysis of patient safety incident reports to describe: the incident and preceding chain of incidents; other contributory factors; and patient harm outcome. We combined findings from exploratory descriptive and thematic analyses to identify key sources of unsafe care.

Results

the main sources of unsafe care in our weighted sample were due to: medication-related incidents e.g. prescribing, dispensing and administering (n = 486, 31%; 15% serious patient harm); communication-related incidents e.g. incomplete or non-transfer of information across care boundaries (n = 390, 25%; 12% serious patient harm); and clinical decision-making incidents which led to the most serious patient harm outcomes (n = 203, 13%; 41% serious patient harm).

Conclusion

priority areas for further research to determine the burden and preventability of unsafe primary care for older adults, include: the timely electronic tools for prescribing, dispensing and administering medication in the community; electronic transfer of information between healthcare settings; and, better clinical decision-making support and guidance.

Understanding the implementation and adoption of an information technology intervention to support medicine optimisation in primary care: qualitative study using strong structuration theory

OBJECTIVES

Using strong structuration theory, we aimed to understand the adoption and implementation of an electronic clinical audit and feedback tool to support medicine optimisation for patients in primary care.

DESIGN

This is a qualitative study informed by strong structuration theory. The analysis was thematic, using a template approach. An a priori set of thematic codes, based on strong structuration theory, was developed from the literature and applied to the transcripts. The coding template was then modified through successive readings of the data.

SETTING

Clinical commissioning group in the south of England.

PARTICIPANTS

Four focus groups and five semi-structured interviews were conducted with 18 participants purposively sampled from a range of stakeholder groups (general practitioners, pharmacists, patients and commissioners).

RESULTS

Using the system could lead to improved medication safety, but use was determined by broad institutional contexts; by the perceptions, dispositions and skills of users; and by the structures embedded within the technology. These included perceptions of the system as new and requiring technical competence and skill; the adoption of the system for information gathering; and interactions and relationships that involved individual, shared or collective use. The dynamics between these external, internal and technological structures affected the adoption and implementation of the system.

CONCLUSIONS

Successful implementation of information technology interventions for medicine optimisation will depend on a combination of the infrastructure within primary care, social structures embedded in the technology and the conventions, norms and dispositions of those utilising it. Future interventions, using electronic audit and feedback tools to improve medication safety, should consider the complexity of the social and organisational contexts and how internal and external structures can affect the use of the technology in order to support effective implementation.

Patient Safety Incidents Involving Sick Children in Primary Care in England and Wales: A Mixed Methods Analysis

BACKGROUND

The UK performs poorly relative to other economically developed countries on numerous indicators of care quality for children. The contribution of iatrogenic harm to these outcomes is unclear. As primary care is the first point of healthcare contact for most children, we sought to investigate the safety of care provided to children in this setting.

METHODS AND FINDINGS

We undertook a mixed methods investigation of reports of primary care patient safety incidents involving sick children from England and Wales' National Reporting and Learning System between 1 January 2005 and 1 December 2013. Two reviewers independently selected relevant incident reports meeting prespecified criteria, and then descriptively analyzed these reports to identify the most frequent and harmful incident types. This was followed by an in-depth thematic analysis of a purposive sample of reports to understand the reasons underpinning incidents. Key candidate areas for strengthening primary care provision and reducing the risks of systems failures were then identified through multidisciplinary discussions. Of 2,191 safety incidents identified from 2,178 reports, 30% (n = 658) were harmful, including 12 deaths and 41 cases of severe harm. The children involved in these incidents had respiratory conditions (n = 387; 18%), injuries (n = 289; 13%), nonspecific signs and symptoms, e.g., fever (n = 281; 13%), and gastrointestinal or genitourinary conditions (n = 268; 12%), among others. Priority areas for improvement included safer systems for medication provision in community pharmacies; triage processes to enable effective and timely assessment, diagnosis, and referral of acutely sick children attending out-of-hours services; and enhanced communication for robust safety netting between professionals and parents. The main limitations of this study result from underreporting of safety incidents and variable data quality. Our findings therefore require further exploration in longitudinal studies utilizing case review methods.

CONCLUSIONS

This study highlights opportunities to reduce iatrogenic harm and avoidable child deaths. Globally, healthcare systems with primary-care-led models of delivery must now examine their existing practices to determine the prevalence and burden of these priority safety issues, and utilize improvement methods to achieve sustainable improvements in care quality.

Multicentre, prospective, randomised, open-label, blinded end point trial of the efficacy of allopurinol therapy in improving cardiovascular outcomes in patients with ischaemic heart disease: protocol of the ALL-HEART study

INTRODUCTION

Ischaemic heart disease (IHD) is one of the most common causes of death in the UK and treatment of patients with IHD costs the National Health System (NHS) billions of pounds each year. Allopurinol is a xanthine oxidase inhibitor used to prevent gout that also has several positive effects on the cardiovascular system. The ALL-HEART study aims to determine whether allopurinol improves cardiovascular outcomes in patients with IHD.

METHODS AND ANALYSIS

The ALL-HEART study is a multicentre, controlled, prospective, randomised, open-label blinded end point (PROBE) trial of allopurinol (up to 600 mg daily) versus no treatment in a 1:1 ratio, added to usual care, in 5215 patients aged 60 years and over with IHD. Patients are followed up by electronic record linkage and annual questionnaires for an average of 4 years. The primary outcome is the composite of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death. Secondary outcomes include all-cause mortality, quality of life and cost-effectiveness of allopurinol. The study will end when 631 adjudicated primary outcomes have occurred. The study is powered at 80% to detect a 20% reduction in the primary end point for the intervention. Patient recruitment to the ALL-HEART study started in February 2014.

ETHICS AND DISSEMINATION

The study received ethical approval from the East of Scotland Research Ethics Service (EoSRES) REC 2 (13/ES/0104). The study is event-driven and results are expected after 2019. Results will be reported in peer-reviewed journals and at scientific meetings. Results will also be disseminated to guideline committees, NHS organisations and patient groups.

TRIAL REGISTRATION NUMBER

32017426, pre-results.

Characterising the nature of primary care patient safety incident reports in the England and Wales National Reporting and Learning System: a mixed-methods agenda-setting study for general practice

Background

There is an emerging interest in the inadvertent harm caused to patients by the provision of primary health-care services. To date (up to 2015), there has been limited research interest and few policy directives focused on patient safety in primary care. In 2003, a major investment was made in the National Reporting and Learning System to better understand patient safety incidents occurring in England and Wales. This is now the largest repository of patient safety incidents in the world. Over 40,000 safety incident reports have arisen from general practice. These have never been systematically analysed, and a key challenge to exploiting these data has been the largely unstructured, free-text data.

Aims

To characterise the nature and range of incidents reported from general practice in England and Wales (2005–13) in order to identify the most frequent and most harmful patient safety incidents, and relevant contributory issues, to inform recommendations for improving the safety of primary care provision in key strategic areas.

Methods

We undertook a cross-sectional mixed-methods evaluation of general practice patient safety incident reports. We developed our own classification (coding) system using an iterative approach to describe the incident, contributory factors and incident outcomes. Exploratory data analysis methods with subsequent thematic analysis was undertaken to identify the most harmful and most frequent incident types, and the underlying contributory themes. The study team discussed quantitative and qualitative analyses, and vignette examples, to propose recommendations for practice.

Main findings

We have identified considerable variation in reporting culture across England and Wales between organisations. Two-thirds of all reports did not describe explicit reasons about why an incident occurred. Diagnosis- and assessment-related incidents described the highest proportion of harm to patients; over three-quarters of these reports (79%) described a harmful outcome, and half of the total reports described serious harm or death (n = 366, 50%). Nine hundred and ninety-six reports described serious harm or death of a patient. Four main contributory themes underpinned serious harm- and death-related incidents: (1) communication errors in the referral and discharge of patients; (2) physician decision-making; (3) unfamiliar symptom presentation and inadequate administration delaying cancer diagnoses; and (4) delayed management or mismanagement following failures to recognise signs of clinical (medical, surgical and mental health) deterioration.

Conclusions

Although there are recognised limitations of safety-reporting system data, this study has generated hypotheses, through an inductive process, that now require development and testing through future research and improvement efforts in clinical practice. Cross-cutting priority recommendations include maximising opportunities to learn from patient safety incidents; building information technology infrastructure to enable details of all health-care encounters to be recorded in one system; developing and testing methods to identify and manage vulnerable patients at risk of deterioration, unscheduled hospital admission or readmission following discharge from hospital; and identifying ways patients, parents and carers can help prevent safety incidents. Further work must now involve a wider characterisation of reports contributed by the rest of the primary care disciplines (pharmacy, midwifery, health visiting, nursing and dentistry), include scoping reviews to identify interventions and improvement initiatives that address priority recommendations, and continue to advance the methods used to generate learning from safety reports.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Setting targets leads to greater long-term weight losses and 'unrealistic' targets increase the effect in a large community-based commercial weight management group

Background

Setting personal targets is an important behavioural component in weight management programmes. Normal practice is to encourage ‘realistic’ weight loss, although the underlying evidence base for this is limited and controversial. The present study investigates the effect of number and size of weight‐loss targets on long‐term weight loss in a large community sample of adults.

Methods

Weight change, attendance and target weight data for all new UK members, joining from January to March 2012, were extracted from a commercial slimming organisation's electronic database.

Results

Of the 35 380 members who had weight data available at 12 months after joining, 69.1% (n = 24 447) had a starting body mass index (BMI) ≥30 kg m^–2. Their mean (SD) weight loss was 12.9% (7.8%) and, for both sexes, weight loss at 12 months was greater for those who set targets (P < 0.001). Those that set ≥4 targets achieved the greatest loss (P < 0.001). The odds ratio for weight loss ≥10% at 12 months was 10.3 (95% confidence interval = 9.7–11.1, P < 0.001) where targets had been set compared to none. At the highest quintile of target size, the size of the first target explained 47.2% (P < 0.001) of the variance in weight loss achieved at 12 months. The mean (SD) BMI reduction in those with a target >25% was 7.6 (4.0) kg m^–2. A higher percentage of obese members did not set targets (P < 0.001) compared to those with a BMI <30 kg m^–2.

Conclusions

Much of the variance in weight loss achieved in this population was explained by the number of targets set and the size of the first target. Although obese people were less likely to set targets, doing so increased the likelihood of achieving clinically significant weight loss and, for some ‘unrealistic’ targets, improved the results.

Primary Care Medication Safety Surveillance with Integrated Primary and Secondary Care Electronic Health Records: A Cross-Sectional Study

Introduction

The extent of preventable medication-related hospital admissions and medication-related issues in primary care is significant enough to justify developing decision support systems for medication safety surveillance. The prerequisite for such systems is defining a relevant set of medication safety-related indicators and understanding the influence of both patient and general practice characteristics on medication prescribing and monitoring.

Objective

The aim of the study was to investigate the feasibility of linked primary and secondary care electronic health record data for surveillance of medication safety, examining not only prescribing but also monitoring, and associations with patient- and general practice-level characteristics.

Methods

A cross-sectional study was conducted using linked records of patients served by one hospital and over 50 general practices in Salford, UK. Statistical analysis consisted of mixed-effects logistic models, relating prescribing safety indicators to potential determinants.

Results

The overall prevalence (proportion of patients with at least one medication safety hazard) was 5.45 % for prescribing indicators and 7.65 % for monitoring indicators. Older patients and those on multiple medications were at higher risk of prescribing hazards, but at lower risk of missed monitoring. The odds of missed monitoring among all patients were 25 % less for males, 50 % less for patients in practices that provide general practitioner training, and threefold higher in practices serving the most deprived compared with the least deprived areas. Practices with more prescribing hazards did not tend to show more monitoring issues.

Conclusions

Systematic collection, collation, and analysis of linked primary and secondary care records produce plausible and useful information about medication safety for a health system. Medication safety surveillance systems should pay close attention to patient age and polypharmacy with respect to both prescribing and monitoring failures; treat prescribing and monitoring as different statistical processes, rather than a combined measure of prescribing safety; and audit the socio-economic equity of missed monitoring.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-015-0304-x) contains supplementary material, which is available to authorized users.

Safety climate in English general practices: workload pressures may compromise safety

OBJECTIVES

Although most health care interactions in the developed world occur in general practice, most of the literature on patient safety has focused on secondary care services. To address this issue, we have constructed a patient safety toolkit for English general practices. We report how practice and respondent characteristics affect scores on our safety climate measure, the PC-Safequest, and address recent concerns with high levels of workload in English general practices.

METHODS

We administered the PC-Safequest, a 30-item tool that was designed to measure safety climate in primary care practices, to 335 primary care staff members in 31 practices in England. Practice characteristics, such as list size and deprivation in the area the practice served, and respondent characteristics, such as whether the respondent was a manager, were also collected and used in a multilevel analysis to predict PC-Safequest scores.

RESULTS

Managers gave their practices significantly higher safety climate scores than did non-managers. Respondents with more years of experience had a more negative perception of the level of workload in their practice. Practices with more registered patients and in areas of higher deprivation provided lower safety climate scores.

CONCLUSIONS

Managers rated their practices more positively on our safety climate measure, so the differences between the perceptions of managers and other staff may need to be reduced in order to build a strong safety culture. Excessive workload for more experienced staff and lower safety climate scores for larger practices may reflect 'burnout'. Concerns that pressures in primary care could affect patient safety are discussed.

A cross-sectional mixed methods study protocol to generate learning from patient safety incidents reported from general practice

INTRODUCTION

Incident reports contain descriptions of errors and harms that occurred during clinical care delivery. Few observational studies have characterised incidents from general practice, and none of these have been from the England and Wales National Reporting and Learning System. This study aims to describe incidents reported from a general practice care setting.

METHODS AND ANALYSIS

A general practice patient safety incident classification will be developed to characterise patient safety incidents. A weighted-random sample of 12,500 incidents describing no harm, low harm and moderate harm of patients, and all incidents describing severe harm and death of patients will be classified. Insights from exploratory descriptive statistics and thematic analysis will be combined to identify priority areas for future interventions.

ETHICS AND DISSEMINATION

The need for ethical approval was waivered by the Aneurin Bevan University Health Board research risk review committee given the anonymised nature of data (ABHB R&D Ref number: SA/410/13). The authors will submit the results of the study to relevant journals and undertake national and international oral presentations to researchers, clinicians and policymakers.

Clinical characteristics of persistent frequent attenders in primary care: case-control study

BACKGROUND

Most frequent attendance in primary care is temporary, but persistent frequent attendance is expensive and may be suitable for psychological intervention. To plan appropriate intervention and service delivery, there is a need for research involving standardized psychiatric interviews with assessment of physical health and health status.

OBJECTIVE

To compare the mental and physical health characteristics and health status of persistent frequent attenders (FAs) in primary care, currently and over the preceding 2 years, with normal attenders (NAs) matched by age, gender and general practice.

METHODS

Case-control study of 71 FAs (30 or more GP or practice nurse consultations in 2 years) and 71 NAs, drawn from five primary care practices, employing standardized psychiatric interview, quality of life, health anxiety and primary care electronic record review over the preceding 2 years.

RESULTS

Compared to NAs, FAs were more likely to report a lower quality of life (P < 0.001), be unmarried (P = 0.03) and have no educational qualifications (P = 0.009) but did not differ in employment status. FAs experienced greater health anxiety (P < 0.001), morbid obesity (P = 0.02), pain (P < 0.001) and long-term pathological and ill-defined physical conditions (P < 0.001). FAs had more depression including dysthymia, anxiety and somatoform disorders (all P < 0.001).

CONCLUSIONS

Persistent frequent attendance in primary care was associated with poor quality of life and high clinical complexity characterized by diverse and often persistent physical and mental multimorbidity. A brokerage model with GPs working in close liaison with skilled psychological therapists is required to manage such persistent complexity.

Safety incidents in the primary care office setting

BACKGROUND

In the United Kingdom, 26% of child deaths have identifiable failures in care. Although children account for 40% of family physicians' workload, little is known about the safety of care in the community setting. Using data from a national patient safety incident reporting system, this study aimed to characterize the pediatric safety incidents occurring in family practice.

METHODS

We undertook a retrospective, cross-sectional, mixed methods study of pediatric reports submitted to the UK National Reporting and Learning System from family practice. Analysis involved detailed data coding using multiaxial frameworks, descriptive statistical analysis, and thematic analysis of a special-case sample of reports. Using frequency distributions and cross-tabulations, the relationships between incident types and contributory factors were explored.

RESULTS

Of 1788 reports identified, 763 (42.7%) described harm to children. Three crosscutting priority areas were identified: medication management, assessment and referral, and treatment. The 4 incident types associated with the most harmful outcomes are errors associated with diagnosis and assessment, delivery of treatment and procedures, referrals, and medication provision. Poor referral and treatment decisions in severely unwell or vulnerable children, along with delayed diagnosis and insufficient assessment of such children, featured prominently in incidents resulting in severe harm or death.

CONCLUSION

This is the first analysis of nationally collected, family practice-related pediatric safety incident reports. Recommendations to mitigate harm in these priority areas include mandatory pediatric training for all family physicians; use of electronic tools to support diagnosis, management, and referral decision-making; and use of technological adjuncts such as barcode scanning to reduce medication errors.

A systematic review investigating interventions that can help reduce consumption of sugar-sweetened beverages in children leading to changes in body fatness

BACKGROUND

Both the prevalence of childhood obesity and the consumption of sugar-sweetened beverages (SSBs) have increased globally. The present review describes interventions that reduce the consumption of SSBs in children and determines whether this leads to subsequent changes in body fatness.

METHODS

Three databases were searched from 2000 to August 2013. Only intervention control trials, ≥6 months in duration, which aimed to reduce the consumption of SSBs in >100 children aged 2-18 years, and reporting changes in body fatness, were included. The quality of selected papers was assessed.

RESULTS

Eight studies met inclusion criteria. Six interventions achieved significant (P < 0.05) reductions in SSB intake, although this was not always sustained. In the two interventions providing replacement drinks, significant differences in body mass index (12- or 18-month follow-up) were reported (P = 0.001 and 0.045). The risk of being overweight/obesity was reduced (P < 0.05) in three of the five education programmes but in one programme only for girls who were overweight at baseline and in one programme only for pupils perceived to be at greater risk at baseline. In the one study that included both provision of water and education, the risk of being overweight was reduced by 31% (P = 0.04) in the intervention group.

CONCLUSIONS

The evidence suggests that school-based education programmes focusing on reducing SSB consumption, but including follow-up modules, offer opportunities for implementing effective, sustainable interventions. Peer support and changing the school environment (e.g. providing water or replacement drinks) to support educational programmes could improve their effectiveness. Home delivery of more suitable drinks has a big impact on reducing SSB consumption, with associated reductions in body weight.

Effectiveness of low-profile supplemental fixation in anterior cruciate ligament reconstructions with decreased bone mineral density

PURPOSE

The purpose of this study was to compare anterior cruciate ligament (ACL) fixation using a bioabsorbable interference screw (BIS) and a supplemental low-profile suture anchor (PushLock 4.5-mm polyetheretherketone anchor; Arthrex, Naples, FL) with a standard BIS fixation to determine if fixation methods were dependent on tibial bone mineral density (BMD).

METHODS

Ten matched pairs of fresh-frozen human female knee specimens (20 total) were harvested with specimen ages ranging from 40 to 65 years. The BMD for each specimen was determined with a dual-energy x-ray absorptiometry scanner. The specimens were divided into 2 groups, 1 with a BIS and the other with a BIS plus a PushLock. Tibial-sided ACL fixation with hamstring tendon grafts was performed on all the specimens. Then, load to failure and stiffness were biomechanically tested.

RESULTS

The BIS-plus-PushLock specimens had a significantly higher mean yield load compared with specimens with the BIS alone (702 N v 517 N, P = .047). However, in samples with lower bone density, there was no statistically significant difference in failure loads between fixation techniques (P = .8566 at BMD of 0.5 g/cm(2)). As the bone density of the samples increased, the failure loads increased for both techniques (P < .0001 for PushLock and P = .0057 for BIS). This BMD-associated increase was greater for the PushLock (P = .0148), resulting in a statistically significant difference in failure load at the upper range tested (P = .0293 at BMD of 0.9 g/cm(2)).

CONCLUSIONS

Supplemental fixation of ACL reconstructions with a PushLock is beneficial in persons with a normal BMD of the proximal tibia, but at a lower BMD, there was no difference in our study.

CLINICAL RELEVANCE

Individuals with normal BMDs may benefit from this supplemental fixation. However, caution should be used in postmenopausal women or individuals with chronic ACL injuries when using this fixation strategy.