Daily PubMed evidence board
Patient-specific implants for joint-sparing reconstruction of segmental tibial and femoral defects : systematic literature review and introduction of a classification framework.
This systematic review looked at studies using custom-made (patient-specific) metal implants, produced with 3D imaging and additive manufacturing, to repa…
Signal score52Research triage score
CertaintyModerateVerify in full text
PMID42246229Source identifier
Research triage, not medical advice
Do not use this summary, score, or benefit-cost estimate to diagnose, treat, prescribe, or change care without reviewing the full study and consulting qualified professionals.
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Plain-English signal
This systematic review looked at studies using custom-made (patient-specific) metal implants, produced with 3D imaging and additive manufacturing, to repair large segments of the femur or tibia while keeping the knee or hip joint intact. The review included 53 studies with 299 patients. Most implants used titanium with porous/lattice regions to encourage bone growth. Different ways of attaching the implants were compared: hybrid fixation (a combination of methods), stems, plates, and nails. Reported five-year implant survival was highest for hybrid fixation (about 97% reported), followed by stems (95%) and plates or nails alone (around 90% each). The authors also introduced a classification system to describe where defects occur and how implants are fixed, to help standardize reporting and communication. The abstract notes many studies came from China, which may affect how generalizable the results are elsewhere.
Why it matters
- Segmental femoral and tibial bone defects are difficult to manage while preserving the native joint; the review summarizes outcomes of patient-specific implants (PSIs), which are increasingly feasible with 3D imaging and additive manufacturing.
- The review reports mechanical (implant) survival across fixation methods, a clinically relevant outcome for reconstructive surgeons planning joint-sparing procedures.
- The proposed classification framework could standardize reporting and design communication, which matters for comparative evaluation, clinical decision-making, and implant development.
- Regional concentration of studies (noted predominance from China) may affect generalizability and regulatory/implementation considerations in other jurisdictions.
Primary outcomes
- Mechanical (implant) survival (five-year Kaplan-Meier survival) for joint-sparing segmental femoral and tibial reconstruction using patient-specific implants; introduction of a classification framework for defect location and fixation type.
Effect summary
Abstract-reported signal: Across 53 studies (299 patients) using titanium patient-specific implants for segmental femoral and tibial reconstruction, hybrid fixation showed the highest reported five-year implant survival (97%), followed by stems (95%) and plate- or nail-only fixation (each ~90%). Structural failure was the most common complication. A new classification scheme was proposed to standardize descriptions of defect location and fixation.
Benefit-cost lens
| Quick take | Systematic-review evidence that hybrid fixation PSIs had higher five-year mechanical survival versus plate/nail alone may influence prioritization of PSI designs; however, implementation/value claims require local baseline failure risks, costs, and feasibility data. |
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| BCR anchor | 2 |
| Time horizon | 3 |
| Discount rate | 0.03 |
| Assumptions | Assessment based on PubMed metadata and abstract only; full-text review may change subgroup counts, event definitions, and survival estimates. |
Benefit-cost fields are assumptions-based unless explicitly source-derived. Treat them as prompts for deeper economic review.
Risk of bias
| Tool | rapid-abstract-screen |
|---|---|
| Verdict | Some concerns |
| Notes | Assessment based solely on PubMed metadata and the abstract. The abstract does not report methods for bias assessment, study-level quality, heterogeneity, or details on how Kaplan-Meier analyses accounted for censoring and variable follow-up. Publication bias and differences in case mix, indication (oncologic vs traumatic), and concurrent biological augmentation are not detailed. |
Harms, equity, conflicts & implementation
| Implementation | Full-text review to extract detailed methods, patient characteristics, follow-up completeness, and failure definitions; cost and capacity assessment for in-house or outsourced PSI manufacturing; regulatory compliance checks; multidisciplinary surgical planning and training; prospective data collection aligned with the proposed classification. |
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| Equity impact | Unclear from abstract. Access to PSI technology, manufacturing capacity, and regulatory pathways likely vary by region and could widen disparities unless addressed. |
| Harms | Abstract reports structural failure as the commonest complication; details on rates, severity, infection, neurovascular injury, or need for revision are not provided in the abstract and require full-text verification. |
| Replication | Unknown from automated PubMed triage; replication would require re-extraction from included studies and assessment of pooled estimates in full text. |
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