Meta-analysis topic ideas in orthopaedics and sports medicine

Orthopaedics produces a lot of small randomized trials and many cohort studies, and a large number of systematic reviews, so the field is crowded in the obvious places (joint replacement, fracture fixation). The gaps are in comparisons that were only recently studied, in rehabilitation, and in injection and device treatments.

Patient-reported outcome measures dominate orthopaedic research, and each joint has its own set. Pooling them needs a decision about standardization, and the minimal clinically important difference matters more than a p-value.

Find a orthopaedics and sports medicine topic that has not been done

SynthGap searches the published literature, checks each candidate against existing systematic reviews, and proposes topics with the primary studies behind them. Start on the Free plan: no card needed, and every run shows every topic it finds.

Where gaps tend to hide in orthopaedics

Injection and biologic treatments

Platelet-rich plasma, hyaluronic acid, corticosteroid and other injections for osteoarthritis and tendinopathy are tested in many small trials with different preparations. Reviews that separate preparations and conditions are more informative.

Rehabilitation protocols

Timing of weight-bearing, supervised versus home-based programmes and blood-flow-restriction training after surgery are compared in trials of varying quality.

Fracture care

Surgical versus non-surgical management of particular fractures, fixation constructs and timing of surgery produce a stream of trials that may reverse earlier observational findings.

Paediatric and adolescent orthopaedics

Fewer trials exist in children, and reviews rely mostly on cohort studies and case series. Growth, skeletal maturity and long follow-up make outcomes harder to define and compare, so a review should state the age bands it covers.

Return to sport and prevention

Injury prevention programmes in different sports and return-to-play criteria after anterior cruciate ligament reconstruction are studied with varying definitions.

Outcomes and effect measures that pool well in orthopaedics

Patient-reported outcome scores (KOOS, Oxford Hip Score, DASH, WOMAC): standardized mean differences when scales differ. Compare against the minimal clinically important difference rather than judging by significance alone.
Pain on a 0 to 10 visual analogue or numerical scale: mean difference, at a stated time point such as 6 weeks or 12 months.
Revision, re-operation, non-union and infection: risk ratios or odds ratios over a stated follow-up. For implants, survival analysis from registers needs its own approach (hazard ratios).
Range of motion and function tests (for example, the timed up and go test): mean differences, noting the measurement method.
Return to sport or return to work: risk ratios at a defined time, with the definition of 'return' (to any level, to the previous level) specified.

Common traps in orthopaedic reviews

Pooling different injection products as 'PRP' when the preparations differ in platelet concentration and leucocyte content.
Using the contralateral limb as a control in a way the trials did not.
Comparing implants using register data without accounting for case mix and surgeon.
Short follow-up that misses late complications of implants and fixation.
A large placebo response in pain outcomes, so an uncontrolled improvement after an injection means little.

Check before you commit

Before committing months to a topic, check that nobody has beaten you to it. Search PubMed with its systematic review filter, the Cochrane Library, the PROSPERO register (for reviews that are registered but not yet published) and Epistemonikos. Look at how recent the latest review is and whether new trials have appeared since its search date. Step-by-step guide.

Starting points to try in SynthGap

These are areas to explore, not claims that they are open. Some may already be well covered, and finding that out quickly is the point.

Blood-flow-restriction training in rehabilitation after knee surgery
Hyaluronic acid versus platelet-rich plasma injections for hip osteoarthritis
Early weight-bearing after ankle fracture surgery

Questions

What is the minimal clinically important difference and why does it matter?

It is the smallest change in a score that patients feel is worth having. A pooled difference can be statistically significant but smaller than this threshold; the review should compare the estimate against it and say so.

How do I check whether an orthopaedic meta-analysis already exists?

Search PubMed with the systematic review filter, the Cochrane Library (Cochrane Musculoskeletal), PROSPERO and Epistemonikos. Many topics have several reviews, so check what is new in the primary evidence since the last search.

Can I mix knee and hip osteoarthritis?

Only if the question is about osteoarthritis in general and you have a reason to expect a similar effect. Report them separately as well, because treatments often work differently by joint.

Other specialties

This page is general methodological guidance, not medical advice, and it does not list specific unreviewed topics. SynthGap's suggestions are AI-generated from the published literature, so verify them before registering a protocol.