Rhodri Williams1, Amal Thomas2, Stefan Bajada3, Tony Antonios4, Rhidian Morgan-Jones5, Jelena Bekvalac6, Philip Adds2. 1. Department of Trauma and Orthopaedics, Hywel Dda University NHS Health Board, Carmarthen, Wales, UK. 2. Institute of Medical and Biomedical Education (Anatomy), St George's University of London, London, UK. 3. Department of Trauma and Orthopaedics, Hywel Dda University NHS Health Board, Carmarthen, Wales, UK. Electronic address: stefan_bajada@yahoo.com. 4. Department of Trauma and Orthopaedics, Guy's & St Thomas' NHS Foundation Trust, London, UK. 5. Department of Trauma and Orthopaedics, Cardiff and Vale NHS University Health Board, Cardiff, Wales, UK. 6. Centre for Human Bioarchaeology, Museum of London, London, UK.
Abstract
BACKGROUND: This large osteology study examined the reliability, reproducibility and correlation between previously described tibial tray rotation alignment lines (including Akagi and Dalury lines). In addition, it described a novel inter-eminence line utilising the tibial plateau inter-condylar eminences as a landmark. METHODS: A total of 214 post-medieval (18-19th centuries) skeletal tibia were examined. The inter/intra-observer variation and correlation between reference lines were measured. RESULTS: Inter-observer reproducibility was excellent and there were no differences between Akagi, Dalury, and inter-eminence lines. Similarly, intra-observer reliability was excellent for Akagi, Dalury, and inter-eminence lines. Qualitative review of tibial inter-condylar eminences suggested that these could be easily identifiable. When taking the medial angle from a medial-lateral reference line, the Akagi line showed a mean of 96.90° (±10.27), inter-eminence line 94.52° (±12.84), and Dalury line 88.06° (±11.75). The angle produced by the Dalury line was significantly different from both the Akagi and inter-eminence lines (P≤0.001). The Akagi line and inter-eminence line showed a strong correlation (r=0.74). The Dalury line showed a weaker correlation with both the Akagi line (r=0.69) and inter-eminence line (r=0.40). CONCLUSION: This study suggested that tibial rotation lines showed excellent intra/inter-observer reliability and reproducibility. The novel and easily drawn inter-eminence line showed strong correlation with the Akagi line and could be used for tibial tray rotational alignment in total knee arthroplasty.
BACKGROUND: This large osteology study examined the reliability, reproducibility and correlation between previously described tibial tray rotation alignment lines (including Akagi and Dalury lines). In addition, it described a novel inter-eminence line utilising the tibial plateau inter-condylar eminences as a landmark. METHODS: A total of 214 post-medieval (18-19th centuries) skeletal tibia were examined. The inter/intra-observer variation and correlation between reference lines were measured. RESULTS: Inter-observer reproducibility was excellent and there were no differences between Akagi, Dalury, and inter-eminence lines. Similarly, intra-observer reliability was excellent for Akagi, Dalury, and inter-eminence lines. Qualitative review of tibial inter-condylar eminences suggested that these could be easily identifiable. When taking the medial angle from a medial-lateral reference line, the Akagi line showed a mean of 96.90° (±10.27), inter-eminence line 94.52° (±12.84), and Dalury line 88.06° (±11.75). The angle produced by the Dalury line was significantly different from both the Akagi and inter-eminence lines (P≤0.001). The Akagi line and inter-eminence line showed a strong correlation (r=0.74). The Dalury line showed a weaker correlation with both the Akagi line (r=0.69) and inter-eminence line (r=0.40). CONCLUSION: This study suggested that tibial rotation lines showed excellent intra/inter-observer reliability and reproducibility. The novel and easily drawn inter-eminence line showed strong correlation with the Akagi line and could be used for tibial tray rotational alignment in total knee arthroplasty.