Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities
Abstract Restricted kinematically aligned total knee arthroplasty (rKA-TKA) for severe deformity in the preoperative hip–knee–ankle angle (HKAA) has gained considerable interest. However, the widespread adoption of rKA-TKA has been limited by its requirement for expensive equipment such as navigatio...
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Nature Portfolio
2025-07-01
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| Series: | Scientific Reports |
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| Online Access: | https://doi.org/10.1038/s41598-025-13195-w |
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| author | Masahiro Ishikawa Masaaki Ishikawa Hideaki Nagashima Takafumi Hiranaka |
| author_facet | Masahiro Ishikawa Masaaki Ishikawa Hideaki Nagashima Takafumi Hiranaka |
| author_sort | Masahiro Ishikawa |
| collection | DOAJ |
| description | Abstract Restricted kinematically aligned total knee arthroplasty (rKA-TKA) for severe deformity in the preoperative hip–knee–ankle angle (HKAA) has gained considerable interest. However, the widespread adoption of rKA-TKA has been limited by its requirement for expensive equipment such as navigation and robotic surgery systems. In this study, we developed manual rKA-TKA with modified soft tissue-respecting technique and investigated its surgical effects on postoperative HKAA. To achieve this, we examined factors affecting postoperative HKAA. Subsequently, the safe zone-related cut-off values of preoperative HKAA were calculated using the receiver operating characteristic curve, and postoperative HKAA was predicted using a linear regression model (LRM) and generalized additive model (GAM). Preoperative HKAA was identified as a factor influencing postoperative HKAA. The cut-off values of preoperative HKAA were −14 and −15° when the safe zones were defined as ± 1–3 and ± 4–5°, respectively. The GAM was more accurate in predicting the postoperative HKAA than the LRM. Additionally, the GAM showed a potential of falling within ± 5° of the postoperative HKAA, even in patients with preoperative HKAA ≤ − 19°. These findings suggest that manual rKA-TKA can be effective even for patients with severe deformities, providing an accessible alternative to conventional TKA for surgeons at resource-limited institutions. |
| format | Article |
| id | doaj-art-abd4a765f14e46d4b45a8e9be74bcc99 |
| institution | DOAJ |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Nature Portfolio |
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| spelling | doaj-art-abd4a765f14e46d4b45a8e9be74bcc992025-08-20T03:04:39ZengNature PortfolioScientific Reports2045-23222025-07-0115111210.1038/s41598-025-13195-wManual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformitiesMasahiro Ishikawa0Masaaki Ishikawa1Hideaki Nagashima2Takafumi Hiranaka3Department of Orthopedic Surgery, Nagahama Red Cross HospitalDepartment of Otolaryngology, Head and Neck Surgery, Hyogo Prefectural Amagasaki General Medical CenterDepartment of Orthopedic Surgery, Nagahama Red Cross HospitalDepartment of Orthopedic Surgery and Joint Surgery Centre, Takatsuki General HospitalAbstract Restricted kinematically aligned total knee arthroplasty (rKA-TKA) for severe deformity in the preoperative hip–knee–ankle angle (HKAA) has gained considerable interest. However, the widespread adoption of rKA-TKA has been limited by its requirement for expensive equipment such as navigation and robotic surgery systems. In this study, we developed manual rKA-TKA with modified soft tissue-respecting technique and investigated its surgical effects on postoperative HKAA. To achieve this, we examined factors affecting postoperative HKAA. Subsequently, the safe zone-related cut-off values of preoperative HKAA were calculated using the receiver operating characteristic curve, and postoperative HKAA was predicted using a linear regression model (LRM) and generalized additive model (GAM). Preoperative HKAA was identified as a factor influencing postoperative HKAA. The cut-off values of preoperative HKAA were −14 and −15° when the safe zones were defined as ± 1–3 and ± 4–5°, respectively. The GAM was more accurate in predicting the postoperative HKAA than the LRM. Additionally, the GAM showed a potential of falling within ± 5° of the postoperative HKAA, even in patients with preoperative HKAA ≤ − 19°. These findings suggest that manual rKA-TKA can be effective even for patients with severe deformities, providing an accessible alternative to conventional TKA for surgeons at resource-limited institutions.https://doi.org/10.1038/s41598-025-13195-wTotal knee arthroplastyRestricted kinematically aligned TKAKinematic alignmentHip–knee–ankle angle |
| spellingShingle | Masahiro Ishikawa Masaaki Ishikawa Hideaki Nagashima Takafumi Hiranaka Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities Scientific Reports Total knee arthroplasty Restricted kinematically aligned TKA Kinematic alignment Hip–knee–ankle angle |
| title | Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| title_full | Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| title_fullStr | Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| title_full_unstemmed | Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| title_short | Manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| title_sort | manual restricted kinematic alignment technique restores postoperative limb alignment in severe knee deformities |
| topic | Total knee arthroplasty Restricted kinematically aligned TKA Kinematic alignment Hip–knee–ankle angle |
| url | https://doi.org/10.1038/s41598-025-13195-w |
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