Orthopedics · Medical Literature
Glenoid reconstruction with screw-type implant versus iliac crest bone grafting for anterior shoulder instability: study protocol for a prospective, multicentre, non-inferiority, randomised controlled trial.
Abstract
Anterior shoulder instability is a common condition, frequently seen in young and active individuals. For patients with critical glenoid bone defects (≥15%), Bankart repair has limited effectiveness and bony augmentation surgery is often required. However, traditional bone grafts carry the risk of graft resorption, while 3D-printed personalised implants aimed at anatomical reconstruction face limitations in accessibility, cost and production time. In this multicentre, randomised controlled trial, anterior shoulder instability patients with critical glenoid bone loss will be screened across five centres. Individuals with multidirectional shoulder instability, concomitant ipsilateral shoulder injuries, concurrent diseases that may affect the joint or those ineligible for surgical intervention will be excluded.Randomisation will be performed in a 1:1 ratio, stratified by age, physical activity level and trial centre. Participants will receive either iliac crest bone grafting (ICBG) or glenoid reconstruction with screw-type implant. The primary analysis will be the difference of the Rowe score between ICBG and glenoid reconstruction patients at 1 year postoperatively. We set the non-inferiority margin at 6 points, corresponding to 60% of the MCID to ensure the clinical relevance of the non-inferiority test. Funded by the Medical Scientific Research Project of the First Affiliated Hospital of Chongqing Medical University (2025QDLXZX-07); Ethics Committee of the First Affiliated Hospital of Chongqing Medical University approved (ZZ2025-938-01). Final results will be updated on trial registries and submitted to a peer-reviewed journal and provide a novel treatment option for patients with anterior shoulder instability and offer a theoretical foundation and evidence base for the development of treatment strategies for similar cases in the future. ChiCtr2500115163.
Clinical relevance
In patients with anterior shoulder instability and critical glenoid bone loss (≥15%), is glenoid reconstruction with a screw-type implant non-inferior to iliac crest bone grafting (ICBG) as measured by the Rowe score at 1 year postoperatively? __SNAPSHOT__ {"studyDesign":"Prospective, multicentre, non-inferiority randomised controlled trial (study protocol publication)","setting":"Five centres; country not explicitly reported in the abstract","sampleSize":"Not reported in the abstract (sample size calculation details not provided in the excerpt supplied)","population":"Adults with anterior shoulder instability and critical glenoid bone loss (≥15%); excluding patients with multidirectional shoulder instability, concomitant ipsilateral shoulder injuries, concurrent diseases that may affect the joint, or those ineligible for surgical intervention","intervention":"Glenoid reconstruction with a screw-type implant","comparator":"Iliac crest bone grafting (ICBG)","primaryOutcome":"Rowe score difference between groups at 1 year postoperatively","followUp":"Minimum 1 year (primary endpoint); longer-term follow-up not specified in the abstract excerpt provided","fundingSource":"Not reported in the abstract"}
Key findings
This is a protocol publication; no outcome data are yet available. The abstract describes trial design, eligibility criteria, and analytic framework only. Randomisation is planned in a 1:1 ratio, stratified by age, physical activity level, and trial centre. The primary analysis will compare Rowe scores at 1-year postoperatively using a pre-specified non-inferiority margin, the numerical value of which is not fully disclosed in the abstract excerpt provided. No p-values, confidence intervals, effect sizes, NNT, NNH, or adverse event rates are reported, as the trial has not yet reported results.
Practice implications
This publication establishes a methodologically structured protocol to address a clinically meaningful gap: whether a screw-type glenoid implant can achieve functional outcomes equivalent to ICBG in patients with critical glenoid bone defects (≥15%), a group in whom isolated Bankart repair has well-documented limitations. The rationale is clinically sound — ICBG carries risks of graft resorption and donor-site morbidity, while 3D-printed patient-specific implants face barriers of cost, accessibility, and lead time; a standardised screw-type implant could offer a more scalable alternative if proven non-inferior. However, no efficacy or safety conclusions can be drawn at this time. The findings, when reported, will apply specifically to the enrolled population (critical bone loss ≥15%, anterior instability, no multidirectional instability, no concomitant ipsilateral injury); they may not generalise to patients outside these criteria, including those with failed prior stabilisation surgery, revision settings, or bone loss thresholds below the trial's inclusion threshold. Critically, this is a protocol paper only, and all clinical conclusions are contingent on successful execution and results reporting. Only the abstract was available for this summary. __LIMITATIONS__ Protocol publication only — no results available; all interpretation is prospective and contingent.,Sample size and statistical power parameters are not disclosed in the abstract excerpt, precluding assessment of whether the trial is adequately powered.,The non-inferiority margin for the Rowe score is not fully stated in the abstract, making it impossible to evaluate the clinical meaningfulness of the threshold chosen.,Blinding: patient and surgeon blinding is inherently unfeasible in surgical trials; assessor and analyst blinding status is not described in the abstract.,The screw-type implant is not named or characterised in the abstract, limiting generalisability across different implant systems.,Exclusion of multidirectional instability and concomitant ipsilateral injuries restricts generalisability to a selected, less complex surgical population.,The Rowe score, while widely used, is a composite scale with ceiling effects and variable responsiveness; patient-reported outcomes such as WOSI or ASES are not mentioned as co-primary or secondary endpoints in the provided excerpt.,Geographic setting and healthcare system context are not reported, limiting assessment of external validity.,Funding source is not disclosed, precluding evaluation of potential industry bias.,One-year follow-up may be insufficient to capture late complications such as implant loosening, progressive osteoarthritis, or graft resorption, which may manifest over longer time horizons. __BOTTOM_LINE_CATEGORY__ not_ready_for_clinical_application __BOTTOM_LINE__ This is a well-framed RCT protocol comparing screw-type glenoid implantation to iliac crest bone grafting for anterior shoulder instability with critical bone loss (≥15%); no results are yet available. The trial addresses a genuine clinical equipoise, as both ICBG donor-site morbidity and implant-specific concerns (resorption, accessibility) remain unresolved in this population. Clinicians should monitor this trial for results before drawing any practice-informing conclusions.