In varus knees with bifocal or mixed deformities (tibial + femoral), a single-level osteotomy may lead to sub-optimal alignment or excessive joint line obliquity. This study investigates whether using patient-specific cutting guides (PSCGs) in a double-level osteotomy (DLO) improves alignment accuracy compared to conventional techniques — without compromising clinical outcomes. Accuracy of correction is a key driver for long-term joint preservation.
Study overview: design, patients & outcome focus
The paper is a comparative/observational study assessing DLO in varus knees with PSCGs vs conventional DLO. Key points:
- Measurement of alignment accuracy (hip-knee-ankle (HKA) correction, medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA))
- Assessment of joint line obliquity (JLO) preservation
- Clinical outcomes at follow-up (PROMs such as KOOS)
The authors found that PSCGs improved the achievement of planned angular correction (i.e., fewer alignment outliers) yet clinical outcomes were comparable to conventional methods.
Key findings: improved accuracy, similar clinical results
- The PSCG group achieved smaller deviation from planned correction in HKA, MPTA, and LDFA compared with conventional group.
- Joint line obliquity was preserved similarly in both groups, indicating that accuracy gains did not come at the expense of JLO integrity.
- At mid-term follow-up, PROMs improved significantly in both groups, with no significant difference in functional scores between PSCG-DLO and conventional DLO. This suggests that better alignment precision did not necessarily translate into superior short-term clinical outcomes.
Clinical implications & surgeon take-home messages
- For varus knees requiring double-level correction (i.e., both femoral and tibial components), using PSCGs can improve the accuracy of the correction plan execution — which may reduce malalignment or over-correction risk.
- While better accuracy is desirable, surgeons should note that this study did not show a clinically superior outcome (in the short-term) when using PSCGs vs conventional. Thus, costs, logistics and case-selection remain important.
- Joint line obliquity preservation remains critical — regardless of tool choice. Surgeons must still perform rigorous deformity analysis and ensure that JLO and mechanical axis are both addressed.
- The decision to use PSCGs should consider surgical complexity, cost-benefit, availability of technology, and the surgeon’s learning curve.
Link to full paper: Double-level osteotomy for varus knees using patient-specific cutting guides: allow more accurate correction but similar clinical outcomes as compared to conventional techniques
Sources used in report overview:
- https://www.researchgate.net/publication/382347995_Double-level_osteotomy_for_varus_knees_using_patient-specific_cutting_guides_allow_more_accurate_correction_but_similar_clinical_outcomes_as_compared_to_conventional_techniques
- https://pubmed.ncbi.nlm.nih.gov/39029793/
- https://www.sciencedirect.com/science/article/pii/S1877056824002056
