Joint Registries

How do 3D-printed primary uncemented acetabular components compare with established uncemented acetabular cups? The experience of the New Zealand National Joint Registry

BACKGROUND

3D-printed or additive manufactured acetabular implants are an exciting new technology being used in hip surgery with increasing frequency especially in complex acetabular reconstructions. However, the performance of acetabular components produced by this method for primary THR is unknown.

METHODS

41,272 uncemented cups in primary THR for OA were identified in the NZJR for the purposed of this study. There were 39,080 uncemented cups in the control group (15,798 Pinnacle cups, 12,724 Trident cups and 10,558 RM Pressfit cups) compared to 2192 3D-printed uncemented implants (1397 Delta TT cups, 640 Ti Por and 155 Polymax cups). All-cause revision rates and reasons for revision were examined. Kaplan-Meier survival analysis was performed.

RESULTS

3D-printed cups were inserted into younger, fitter patients with a higher mean BMI compared to those in the control group (p < 0.001). The overall all-cause revision rate for 3D-printed cups was not significantly different to the controls: 0.77/100 cys (95% CI 0.59-1) compared to 0.55/100 cys (95% CI 0.52-0.58) in the control group (p = 0.058, Hazards ratio 1.29, 95% CI 0.992-1.678). There was no difference in aseptic cup loosening or deep infection rates between either group or indeed individual implant designs.

CONCLUSIONS

3D-printed uncemented cups provide reliable survivorship and clinical results in primary THR comparable to established designs manufactured by traditional means. The theoretical concerns of increased rates of fatigue failure or deep infection are unsubstantiated.

Trajectories of pain and function in the first five years after total hip and knee arthroplasty : an analysis of patient reported outcome data from the National Joint Registry

AIMS

To determine the trajectories of patient reported pain and functional disability over five years following total hip arthroplasty (THA) or total knee arthroplasty (TKA).

METHODS

A prospective, longitudinal cohort sub-study within the National Joint Registry (NJR) was undertaken. In all, 20,089 patients who underwent primary THA and 22,489 who underwent primary TKA between 2009 and 2010 were sent Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires at six months, and one, three, and five years postoperatively. OHS and OKS were disaggregated into pain and function subscales. A k-means clustering procedure assigned each patient to a longitudinal trajectory group for pain and function. Ordinal regression was used to predict trajectory group membership using baseline OHS and OKS score, age, BMI, index of multiple deprivation, sex, ethnicity, geographical location, and American Society of Anesthesiologists grade.

RESULTS

Data described two discrete trajectories for pain and function: 'level 1' responders (around 70% of cases) in whom a high level of improvement is sustained over five years, and 'level 2' responders who had sustained improvement, but at a lower level. Baseline patient variables were only weak predictors of pain trajectory and modest predictors of function trajectory. Those with worse baseline pain and function tended to show a greater likelihood of following a 'level 2' trajectory. Six-month patient-reported outcome measures data reliably predicted the class of five-year outcome trajectory for both pain and function.

CONCLUSION

The available preoperative patient variables were not reliable predictors of postoperative pain and function after THA and TKA. Reviewing patient outcomes at six months postoperatively is a reliable indicator of outcome at five years. Cite this article: Bone Joint J 2021;103-B(6):1111-1118.

How do cemented short Exeter stems perform compared with standard-length Exeter stems? The experience of the New Zealand National Joint Registry

Background

The standard Exeter (Stryker) cemented stem is 150 mm long with standard offsets ranging from 37.5 mm to 56 mm. Exeter short stems of 125 mm are also available in the offsets of 37.5 mm, 44 mm, and 50 mm. In addition, smaller (125 mm or shorter) Exeter cemented stems with offsets of 35.5 mm or less are available. The aim of this study was to examine the New Zealand Joint Registry (NZJR) comparing medium-term survival rates and functional outcomes of standard-length stems with Exeter short stems of various offsets in patients undergoing primary total hip replacement.

Methods

Using the NZJR, we compared the results of 3 separate groups of patients with Exeter stems. Patients with standard 150 mm length Exeter stems (Standard) were compared with patients with Exeter 125 mm stems with regular 37.5 mm, 44 mm, and 50 mm offsets (Short 37+) and Exeter 125 mm stems with offsets of 35.5 mm and below (Short 37−). Demographic data, preoperative diagnosis, patient-reported outcome measures, and reasons for revision were compared between groups. Kaplan-Meier survival analysis and Cox multivariate regression analysis were used to examine implant survival and the influence of stem group on revision rates adjusting for gender, age, diagnosis, and surgical approach.

Results

There were 43,427 Exeter cemented stems in the NZJR between January 1, 1999 and 31, May 2018; 41,629 Standard, 657 Short 37+, and 1501 Short 37−. In all 3 groups, the posterior surgical approach was preferred (Standard, 76.1%; Short 37+, 94.6%; Short 37−, 76.6%; P < .001). In the Short 37− group, 94.1% were female, while in the other 2 groups, there was an equal gender ratio (P < .001). The Short 37- group was also significantly younger than the other 2 groups with 41.6% younger than 65 years compared with Short 37+ (37.2%) and Standard groups (36.9%) (P < .01). There was no difference in American Society of Anesthesiologists grade between groups. Body mass index (BMI) was significantly higher in both the Short 37− and Short 37 + groups compared with the Standard group (Standard BMI, 28.71; SD 5.72; Short 37+ BMI, 29.69; SD, 6.67; Short 37− BMI, 29.09; SD 7.07; P < .001). The all-cause revision rate for standard stems was 0.55/100 component years (cy) (95% CI: 0.52 to 0.58). The Short 37− group had a higher rate of revision compared with the Standard group (hazard ratio 1.6; 95% CI: 1.3 to 1.98; P < .001), while the Short 37+ group had a hazard ratio of 0.84 (95% CI: 0.38 to 1.88; P = .674) compared with the Standard group. Cox regression analysis controlling for age, gender, diagnosis of OA, and surgical approach did not affect these findings. However, no clinically meaningful difference between Oxford hip scores was observed.

Conclusions

There was a significant difference in revision rates for aseptic loosening with standard-length Exeter stems having a lower revision rate than short Exeter stems with offsets 35.5 mm or less. The Short 37+ groups, despite comprising relatively small numbers, performed similarly to the Standard stem group.

Safety of single-anaesthetic versus staged bilateral primary total knee replacement: experience from the New Zealand National Joint Registry

BACKGROUND

Surgical management options for bilateral knee osteoarthritis comprise staged or single-anaesthetic bilateral total knee replacements (SABTKRs). We examined the New Zealand Joint Registry hypothesizing there would be no difference between these practices compared to unilateral total knee replacement (TKR) examining 30-day mortality, all-cause revision rate and function.

METHODS

For this study, 84 946 primary TKRs were identified. We compared three groups: unilateral TKRs, all SABTKRs and all staged bilateral TKRs with intervals of 1 to 90 days, 91 days to 1 year and >1 year. Cumulative revision rates were calculated (Kaplan-Meier method). Mortality risks were compared to unilateral TKR and hazard ratios (HRs) calculated. Six-month Oxford scores were compared using analysis of variance.

RESULTS

Thirty-day mortality for SABTKR was 0.219%: unilateral TKR 0.236% (HR 0.43; 95% confidence interval (CI) 0.38-0.48; P < 001). Staged TKR had lower mortality than unilateral TKR at three time interval groups unless performed within 90 days (adjusting for age and American Society of Anesthesiologists grade) TKR (<90 days HR 0.92; 95% CI 0.703-1.371; P = 0.915; 91-365 days HR 0.783; 95% CI 0.687-0.891; P < 0.001; >365 days HR 0.394; 95% CI 0.344-0.451; P < 0.001). Revision risk with SABTKR was lower at 0.43/100 component years (95% CI 0.37-0.49/100 component years) compared to unilateral 0.56/100 component years (95% CI 0.53-0.59; P < 0.05). Six-month Oxford scores were superior in SABTKR versus unilateral TKR (38.6 (95% CI 38.2-39) versus 36.9 (95% CI 36.8-37.1); P < 0.001).

CONCLUSIONS

SABTKR is at least as safe as unilateral TKR or staged bilateral TKR in appropriately selected cases. Surgeons should wait at least 90 days before the second procedure.

Is single-anaesthetic bilateral primary total hip replacement still safe? A 16-year cohort study from the New Zealand Joint Registry

BACKGROUND

The surgical management options for bilateral hip osteoarthritis comprise staged or single-anaesthetic bilateral total hip replacements (THRs). The key issue of contention in performing the latter remains safety. We compared unilateral, staged bilateral and single-anaesthetic bilateral THR with the hypothesis that there would be no difference between these three practices using mortality risk, functional outcome and revision rate as the primary outcome measures.

METHODS

We performed a retrospective cohort analysis of the New Zealand Joint Registry identifying all primary THRs performed between 1 January 1999 and 31 December 2015. We report this study in accordance with STROBE and RECORD guidelines. We identified all unilateral THRs, all single-anaesthetic bilateral THRs and all staged bilateral THRs and compared the mortality risk, all-cause revision risk with Kaplan-Meier survival analysis and reasons for revision and functional outcome using the Oxford 12 scores. Analysis was adjusted for age, gender, American Society of Anesthesiologists rating score and body mass index.

RESULTS

The mortality risk for single-anaesthetic bilateral THR within 3 months was 0.26% and for unilateral THR 0.75% (hazard ratio 0.35 (95% confidence interval (CI) 0.30-0.41, P < 0.001). The risk of revision in the single-anaesthetic bilateral THR group was 0.69/100 component years (95% CI 0.59-0.79/100 component years) versus 0.74/100 component years (95% CI 0.72-0.77/100 component years) in unilateral THR. Mean Oxford 12 scores at 6 months post-arthroplasty was 41.7 (95% CI 41.2-42.2) in the single-anaesthetic bilateral THR group. The best results in the staged bilateral THR group were obtained if the second procedure was delayed by at least 90 days from the first THR.

CONCLUSIONS

Single anaesthetic bilateral THR is at least as safe as unilateral THR or staged bilateral THR in appropriately selected cases. Experienced surgeons can expect predictable survival rates and functional scores.

The effectiveness of ultra-clean air operating theatres in the prevention of deep infection in joint arthroplasty surgery

Deep infection was identified as a serious complication in the earliest days of total hip arthroplasty. It was identified that airborne contamination in conventional operating theatres was the major contributing factor. As progress was made in improving the engineering of operating theatres, airborne contamination was reduced. Detailed studies were carried out relating airborne contamination to deep infection rates.

In a trial conducted by the United Kingdom Medical Research Council (MRC), it was found that the use of ultra-clean air (UCA) operating theatres was associated with a significant reduction in deep infection rates. Deep infection rates were further reduced by the use of a body exhaust system. The MRC trial also included a detailed microbiology study, which confirmed the relationship between airborne contamination and deep infection rates.

Recent observational evidence from joint registries has shown that in contemporary practice, infection rates remain a problem, and may be getting worse. Registry observations have also called into question the value of “laminar flow” operating theatres.

Observational evidence from joint registries provides very limited evidence on the efficacy of UCA operating theatres. Although there have been some changes in surgical practice in recent years, the conclusions of the MRC trial remain valid, and the use of UCA is essential in preventing deep infection.

There is evidence that if UCA operating theatres are not used correctly, they may have poor microbiological performance. Current UCA operating theatres have limitations, and further research is required to update them and improve their microbiological performance in contemporary practice.

Cite this article: Bone Joint J 2018;100-B:1264–9.

Temporal trends and survivorship of total hip arthroplasty in very young patients

Aims

The aim of this study was to describe temporal trends and survivorship of total hip arthroplasty (THA) in very young patients, aged ≤ 20 years.

Patients and Methods

A descriptive observational study was undertaken using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man between April 2003 and March 2017. All patients aged ≤ 20 years at the time of THA were included and the primary outcome was revision surgery. Descriptive statistics were used to summarize the data and Kaplan–Meier estimates calculated for the cumulative implant survival.

Results

A total of 769 THAs were performed in 703 patients. The median follow-up was 5.1 years (interquartile range (IQR) 2.6 to 7.8). Eight patients died and 35 THAs were revised. The use of metal-on-metal (MoM) bearings and resurfacing procedures declined after 2008. The most frequently recorded indications for revision were loosening (20%) and infection (20%), although the absolute risk of these events occurring was low (0.9%). Factors associated with lower implant survival were MoM and metal-on-polyethylene (MoP) bearings and resurfacing arthroplasty ( vs ceramic-on-polyethylene (CoP) and ceramic-on-ceramic (CoC) bearings, p = 0.002), and operations performed by surgeons who undertook few THAs in this age group as recorded in the NJR ( vs those with five or more recorded operations, p = 0.030). Kaplan–Meier estimates showed 96% (95% confidence interval (CI) 94% to 98%) survivorship of implants at five years.

Conclusion

Within the NJR, the overall survival for very young patients undergoing THA exceeded 96% during the first five postoperative years. In the absence of studies that can better account for differences in the characteristics of the patients, surgeons should consider the association between early revision and the type of implant, the number of THAs performed in these patients, and the bearing surface when performing THA in very young patients. Cite this article: Bone Joint J 2018;100-B:1320–9.

Outcomes and early revision rate after medial unicompartmental knee arthroplasty: prospective results from a non-designer single surgeon

Background

This prospective study evaluates outcomes and reoperation rates for unicompartmental knee arthroplasty (UKA) from a single non-designer surgeon using relatively extended criteria of degenerative changes of grade 2 or above in either or both non-operated compartments.

Methods

187 consecutive medial mobile bearing UKA implants were included after history, clinical assessment and radiological evaluation. 91 patients had extended clinical outcomes. Post-operative assessment included functional scoring with the Oxford Knee Score (OKS) and radiographic review. Survivorship curves were constructed using the life-table method, with 95% confidence intervals calculated using Rothman’s equation. Separate endpoints were examined: revision for any reason and revision for confirmed loosening.

Results

The mean follow-up was 3.5 years. The pre-operative OKS improved from a mean of 21.2 to 38.9 (Mann-Whitney U Test, p = < 0.001). Twelve Patients required further operations including 9 revisions. No patients developed deep infection and no surviving implants were loose radiographically. Survivorship at 7 years with endpoints of re-operation, revision and aseptic loosening at surgery or radiographically was 88.4% (95% CI 79.6–93.7), 93.1% (95% CI 85.5–96.9) and 97.3% (95% CI 91.2–99.2) respectively. The presence of pre-operative mild contralateral tibiofemoral or any extent of patellofemoral joint degeneration was of no consequence.

Discussion

The indications for UKA are being expanded to include patients with greater deformity, more advanced disease in the patellofemoral joint and even certain features in the lateral compartment indicative of an anteromedial pattern of osteoarthritis (OA). However, much of the supporting literature remains available only from designer centres. This study represents a group of patients with what we believe to be wider indications, along with decisions to treat made on clinical grounds and radiographs alone.

Conclusion

This study shows comparable clinical outcomes of UKA for extended indications from a high volume, high-usage non-designer unit.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2099-2) contains supplementary material, which is available to authorized users.

Trends in hip replacements between 1999 and 2012 in Sweden

National Registers document changes in the circumstance, practice, and outcome of surgery with the passage of time. In the context of total hip replacement (THR), registers can help elucidate the relevant factors that affect the clinical outcome. We evaluated the evolution of factors related to patient, surgical procedure, socio-economy, and various outcome parameters after merging databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length-of-stay, mortality rate, adverse events, re-operation and revision rates, and Patient Reported Outcome Measures (PROMs). Throughout this time period the majority of patients were operated on with a diagnosis of primary osteoarthritis. Comorbidity indices increased each year observed. The share of all-cemented implants has dropped from 92% to 68%. More than 88% of the bearings were metal-on-polyethylene. Length-of-stay decreased by 50%. There was a reduction in 30- and 90-day mortality. Re-operation and revision rates at 2 years are decreasing. The post-operative PROMs improved despite the observation of worse pre-operative pain scores getting over time. The demographics of patients receiving a THR, their comorbidities, and their primary diagnosis are changing. Notwithstanding these changes, outcomes like mortality, re-operations, revisions, and PROMs have improved. The practice of hip arthroplasty has evolved, even in a country such as Sweden that is considered to be conservative with regard taking on new surgical practices. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:432-442, 2018.

The myths of ‘big data’ in health care

‘Big data’ is a term for data sets that are so large or complex that traditional data processing applications are inadequate. Billions of dollars have been spent on attempts to build predictive tools from large sets of poorly controlled healthcare metadata. Companies often sell reports at a physician or facility level based on various flawed data sources, and comparative websites of ‘publicly reported data’ purport to educate the public. Physicians should be aware of concerns and pitfalls seen in such data definitions, data clarity, data relevance, data sources and data cleaning when evaluating analytic reports from metadata in health care.

Cite this article: Bone Joint J 2017;99-B:1571–6.

Advantages and limitations of national arthroplasty registries. The need for multicenter registries: the Rempro-SBQ

While the value of national arthroplasty registries (NAR) for quality improvement in total hip arthroplasty (THA) has already been widely reported, some methodological limitations associated with observational epidemiological studies that may interfere with the assessment of safety and efficacy of prosthetic implants have recently been described in the literature.

Among the main limitations of NAR, the need for at least 80% compliance of all health institutions covered by the registry is emphasized; completeness equal or greater than 90% of all THA performed; restricted data collection; use of revision surgery as the sole criterion for outcome; and the inability of establishing a definite causal link with prosthetic dysfunction.

The present article evaluates the advantages and limitations of NAR, in the light of current knowledge, which point to the need for a broader data collection and the use of more structured criteria for defining outcomes.

In this scenario, the authors describe of idealization, conceptual and operational structure, and the project of implantation and implementation of a multicenter registry model, called Rempro-SBQ, which includes healthcare institutions already linked to the Brazilian Hip Society (Sociedade Brasileira de Quadril [SBQ]). This partnership enables the collection of more reliable and comprehensive data at a higher hierarchical level, with a significant reduction in maintenance and financing costs. The quality improvement actions supported by SBQ may enhance its effectiveness and stimulate greater adherence for collecting, storing, interpreting, and disseminating information (feedback).

Risk factors for failure of the 36 mm metal-on-metal Pinnacle total hip arthroplasty system: a retrospective single-centre cohort study

Aims

To determine ten-year failure rates following 36 mm metal-on-metal (MoM) Pinnacle total hip arthroplasty (THA), and identify predictors of failure.

Patients and Methods

We retrospectively assessed a single-centre cohort of 569 primary 36 mm MoM Pinnacle THAs (all Corail stems) followed up since 2012 according to Medicines and Healthcare Products Regulation Agency recommendations. All-cause failure rates (all-cause revision, and non-revised cross-sectional imaging failures) were calculated, with predictors for failure identified using multivariable Cox regression.

Results

Failure occurred in 97 hips (17.0%). The ten-year cumulative failure rate was 27.1% (95% confidence interval (CI) 21.6 to 33.7). Primary implantation from 2006 onwards (hazard ratio (HR) 4.30; 95% CI 1.82 to 10.1; p = 0.001) and bilateral MoM hip arthroplasty (HR 1.59; 95% CI 1.03 to 2.46; p = 0.037) predicted failure. The effect of implantation year on failure varied over time. From four years onwards following surgery, hips implanted since 2006 had significantly higher failure rates (eight years 28.3%; 95% CI 23.1 to 34.5) compared with hips implanted before 2006 (eight years 6.3%; 95% CI 2.4 to 15.8) (HR 15.2; 95% CI 2.11 to 110.4; p = 0.007).

Conclusion

We observed that 36 mm MoM Pinnacle THAs have an unacceptably high ten-year failure rate, especially if implanted from 2006 onwards or in bilateral MoM hip patients. Our findings regarding implantation year and failure support recent concerns about the device manufacturing process. We recommend all patients undergoing implantation since 2006 and those with bilateral MoM hips undergo regular investigation, regardless of symptoms.

Cite this article: Bone Joint J 2017;99-B:592–600.

Is There Anything to Learn from a National Joint Registry?

National joint registries (NJRs) have been established in Northern Europe for over 20 years. Since then, many other countries have begun collecting and reporting national data for total ankle arthroplasty (TAA). With relatively small numbers implanted, a large variety of available designs, and with any long-term reports dominated by designer groups, TAA is ideally placed to benefit from large national or even pooled national registries. This article reviews the existing registry-based literature with respect to what is already known. The potential positives and down sides of registry data also are highlighted.

When is the ideal time to operate on a patient with a fracture of the hip?

Fractures of the hip are common, often occurring in frail elderly patients, but also in younger fit healthy patients following trauma. They have a significant associated mortality and major social and financial implications to patients and health care providers. Many guidelines are available for the management of these patients, mostly recommending early surgery for the best outcomes. As a result, healthcare authorities now put pressure on surgical teams to ‘fast track’ patients with a fracture of the hip, often misquoting the available literature, which in itself can be confusing and even conflicting.

This paper has been written following an extensive review of the available literature. An attempt is made to clarify what is meant by early surgery (expeditious versus emergency), and we conclude with a personal view for the practical management of these patients of variable age, fitness and type of surgery performed within services that are often under considerable pressure of finance and available operating theatres and qualified staff.

Cite this article: Bone Joint J 2016;98-B:1573–81.

The manufacture of generic replicas of implants for arthroplasty of the hip and knee

Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results.

The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies.

Cite this article: Bone Joint J 2016;98-B:892–900.

Are all metal-on-metal hip revision operations contributing to the National Joint Registry implant survival curves? : a study comparing the London Implant Retrieval Centre and National Joint Registry datasets

AIMS

The National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records.

METHODS

We analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included.

RESULTS

We were able to link 716 (77.1%) revision procedures on the NJR to the LIRC. This meant that 213 (22.9%) revision procedures at the LIRC could not be identified on the NJR. We found that 349 (37.6%) explants at the LIRC completed the full linkage process to both NJR primary and revision databases. Data completion was excellent (> 99.9%) for revision procedures reported to the NJR.

DISCUSSION

This study has shown that only approximately one third of retrieved components at the LIRC, contributed to survival curves on the NJR. We recommend prospective registry-retrieval linkage as a tool to feedback missing and erroneous data to the NJR and improve data quality.

TAKE HOME MESSAGE

Prospective Registry - retrieval linkage is a simple tool to evaluate and improve data quality on the NJR.

A Community-Based Hip Fracture Registry: Population, Methods, and Outcomes

Cases of hip fracture recorded from 1/2009 to 12/2011 were ascertained using the Kaiser Permanente Hip Fracture Registry. The registry collects information on patient, procedure, surgeon, facility, and surgical outcomes. The population (N = 12,562) was predominantly white, women, and older (≥ 75 years), and 32% had at least 5 comorbidities. The average length of follow-up was 1.1 years. Hemiarthroplasty was the most common procedure (33.1%). Most fractures were treated by medium-volume surgeons at high-volume facilities. The 90-day readmission rate was 22.1%, and the mortality rate was 12.3%.

Evaluation of the foot and ankle outcome score in patients with osteoarthritis of the ankle

The foot and ankle outcome score (FAOS) has been evaluated for many conditions of the foot and ankle. We evaluated its construct validity in 136 patients with osteoarthritis of the ankle, its content validity in 37 patients and its responsiveness in 39. Data were collected prospectively from the registry of patients at our institution.

All FAOS subscales were rated relevant by patients. The Pain, Activities of Daily Living, and Quality of Life subscales showed good correlation with the Physical Component score of the Short-Form-12v2. All subscales except Symptoms were responsive to change after surgery.

We concluded that the FAOS is a weak instrument for evaluating osteoarthritis of the ankle. However, some of the FAOS subscales have relative strengths that allow for its limited use while we continue to seek other satisfactory outcome instruments.

Cite this article: Bone Joint J 2015; 97-B:662–7.

The rise of big clinical databases

BACKGROUND

The routine collection of large amounts of clinical data, 'big data', is becoming more common, as are research studies that make use of these data source. The aim of this paper is to provide an overview of the uses of data from large multi-institution clinical databases for research.

METHODS

This article considers the potential benefits, the types of data source, and the use to which the data is put. Additionally, the main challenges associated with using these data sources for research purposes are considered.

RESULTS

Common uses of the data include: providing population characteristics; identifying risk factors and developing prediction (diagnostic or prognostic) models; observational studies comparing different interventions; exploring variation between healthcare providers; and as a supplementary source of data for another study. The main advantages of using such big data sources are their comprehensive nature, the relatively large number of patients they comprise, and the ability to compare healthcare providers. The main challenges are demonstrating data quality and confidently applying a causal interpretation to the study findings.

CONCLUSION

Large clinical database research studies are becoming ubiquitous and offer a number of potential benefits. However, the limitations of such data sources must not be overlooked; each research study needs to be considered carefully in its own right, together with the justification for using the data for that specific purpose.

‘Big data’ reporting guidelines

The extent and depth of routine health care data are growing at an ever-increasing rate, forming huge repositories of information. These repositories can answer a vast array of questions. However, an understanding of the purpose of the dataset used and the quality of the data collected are paramount to determine the reliability of the result obtained.

This Editorial describes the importance of adherence to sound methodological principles in the reporting and publication of research using ‘big’ data, with a suggested reporting framework for future Bone & Joint Journal submissions.

Cite this article: Bone Joint J 2014;96-B:1575–7.