We developed a protocol for the review (in German), which is available from the corresponding author. It was written following the structure of PROSPERO and finalized on the 30th of April 2018. We did not register the protocol anywhere. Reporting on the findings of this scoping review we followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for scoping reviews).15 Previously we reported this scoping review to the Swiss Federal Office of Public Health. Considering this to be the feasibility test of performing HTA we also sighted the other domains of an HTA like costs, legal, social and organisational issues.16 We did not find any evidence on these issues. Which is why we only concentrate on effectiveness in this manuscript. Please refer to the report provided to the Swiss Federal Office of Public Health for any detail regarding the results for other domains than effectiveness. That publication contains results from the systematic search conducted in October 2018 (containing 10 studies) only. 16
We included studies analysing asymptomatic patients with an internal fixation in the lower or upper extremities. All age groups were eligible. We considered the elective (without medical indication) removal of the internal fixation device/s as experimental intervention and non-removal of the internal fixation as control intervention. All types of health outcomes were considered. This includes mortality, morbidity (pain, satisfaction, physical functioning and clinical events), clinical measures (e.g. range of motion), health-related quality of life and adverse events/complications. The inclusion was limited to studies in WHO Stratum A. This covers states with very low child and very low adult mortality including western Europe, North-America and various Western-Pacific states.(16) We chose this criterion for two reasons. First, access to and health services are comparable in these countries as is morbidity and mortality. Transferability of technological appraisals might be restricted from countries which are non WHO Stratum A.17 Second is a pragmatic reason, elective removal of asymptomatic implants seems to be a novel trend in recent years in less developed countries and we did not expect many research yet.18 We did not define any other exclusion criteria regarding the population. We considered the following comparative study designs: Randomized controlled trials, non-randomized controlled trials, cohort studies, case-control studies, before-after studies, interrupted-time-series, controlled before-after studies. We did not make any restrictions regarding publication date. We only included studies written in German or English as the reviewers could only ensure to review these languages in duplicate.
We performed a systematic literature search in Pubmed, Embase, EconLit and CINAHL (all from inception) in October 2018 and updated in November 2019. The search strategy for Pubmed is displayed in box 1. The search strategies for the other databases can be found in appendix I. The strategy was developed by our information specialist and checked by another reviewer by consulting the Peer Review of Electronic Search Strategies (PRESS) criteria.19 Deviating from the protocol, intending to search the database CENTRAL, we decided to perform another search in CINAHL instead, due to the high number of overlapping literature in the databases Pubmed, Embase and CENTRAL.
We performed the literature search without limiting the publication date. We applied search limitations to English and German articles and excluded comments, editorials, letters and research on animals in our electronic database search. We cross-checked all references of included articles and systematic reviews on similar topics known to us.
Box 1: search strategy for Pubmed.
osteosynthesis[tiab] OR osteosyntheses[tiab] OR osteosynthetic[tiab] OR orthopedic[tiab] OR orthopaedic[tiab] OR osteotomy[tiab] OR osteotomies[tiab] OR "Fractures, Bone"[Mesh] OR fracture[tiab] OR fractures[tiab]
AND ("Fracture Fixation, Intramedullary"[Mesh] OR "Fracture Fixation, Internal"[Mesh] OR "Fracture Fixation"[Mesh] OR "Surgical Fixation Devices"[Mesh] OR "Orthopedic Fixation Devices"[Mesh] OR "Internal Fixators"[Mesh] OR "Bone Nails"[Mesh] OR "Bone Plates"[Mesh] OR "Bone Screws"[Mesh] OR "Bone Wires"[Mesh] OR material[tiab] OR materials[tiab] OR implant[tiab] OR implants[tiab] OR implantation[tiab] OR implantations[tiab] OR internal fixator*[tiab] OR intramedullary nail*[tiab] OR intramedullary fixation[tiab] OR internal fixation[tiab] OR hardware[tiab] OR plate[tiab] OR plates[tiab] OR nail[tiab] OR nails[tiab] OR screw[tiab] OR screws[tiab] OR wire[tiab] OR wires[tiab] OR pin[tiab] OR pins[tiab])
AND ("Device Removal"[Mesh] OR remov*[tiab])
NOT ("Comment" [Publication Type] OR "Letter" [Publication Type] OR "Editorial" [Publication Type])
NOT (animals[mh] NOT humans[mh])
Selection of sources of evidence
Records identified through the searches were added to an Endnote X7 database and duplicates were removed. All titles/abstracts identified in the electronic databases were screened by one reviewer and a second reviewer screened all excluded titles/abstracts (liberal acceleration). All articles judged to be potentially relevant were obtained. The full-texts off all potentially relevant articles were screened by two reviewers independently. Any disagreement in the study selection process was resolved in a discussion until consensus.
Data charting process and data items
Data was collected in an a priori-piloted abstraction table by one reviewer, the other reviewer monitored all entries for completeness and accuracy.
We extracted following study characteristics: author, publication year, region, setting, study design, recruitment period, inclusion/exclusion criteria, patient characteristics (age, body-mass index, comorbidities, fracture characteristics, surgery characteristics), time points measured, outcomes.
Critical appraisal of individual sources of evidence
As this is a scoping review, there was no risk of bias assessment. This is consistent with guidance on the conduct of scoping reviews.20
Synthesis of results
We used Arksey and O’Malley’s methods and provide a descriptive analysis of the extent, nature, and distribution of the studies included in the review as well as a narrative, thematic summary of the data collected.20 For this we summarized the literature considering study types, location/type of the material and outcomes. On this basis we analyzed similarities and differences within and in between studies to identify patterns and themes and postulate explanations for findings. Furthermore we developed an evidence map illustrating the type of evidence, indications and outcomes.