How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis
Aims: While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) re...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
The British Editorial Society of Bone & Joint Surgery
2024-02-01
|
| Series: | Bone & Joint Open |
| Subjects: | |
| Online Access: | https://online.boneandjoint.org.uk/doi/epdf/10.1302/2633-1462.52.BJO-2023-0122 |
| _version_ | 1797289636840603648 |
|---|---|
| author | Luke E. Corban Victor A. van de Graaf Darren B. Chen Jil A. Wood Ashish D. Diwan Samuel J. MacDessi |
| author_facet | Luke E. Corban Victor A. van de Graaf Darren B. Chen Jil A. Wood Ashish D. Diwan Samuel J. MacDessi |
| author_sort | Luke E. Corban |
| collection | DOAJ |
| description | Aims: While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. Methods: A retrospective cohort study was undertaken of 700 primary MA TKAs (643 patients) performed between 2014 and 2017. Lateral distal femoral and medial proximal tibial angles were measured pre- and postoperatively to calculate the arithmetic hip-knee-ankle angle (aHKA), JLO, and Coronal Plane Alignment of the Knee (CPAK) phenotypes. The primary outcome was the magnitude and direction of aHKA, JLO, and CPAK alterations. Results: The mean aHKA and JLO increased by 0.1° (SD 3.4°) and 5.8° (SD 3.5°), respectively, from pre- to postoperatively. The most common phenotypes shifted from 76.3% CPAK Types I, II, or III (apex distal JLO) preoperatively to 85.0% IV, V, or VI (apex horizontal JLO) postoperatively. The proportion of knees with apex proximal JLO increased from 0.7% preoperatively to 11.1% postoperatively. Among all MA TKAs, 60.0% (420 knees) were changed from their constitutional alignments into CPAK Type V, while 40.0% (280 knees) either remained in constitutional Type V (5.0%, 35 knees) or were unintentionally aligned into other CPAK types (35.0%; 245 knees). Conclusion: Fixed MA targets in TKA lead to substantial changes from constitutional alignment, primarily a significant increase in JLO. These findings enhance our understanding of alignment alterations resulting from both unintended changes to knee phenotypes and surgical resection imprecision. Cite this article: Bone Jt Open 2024;5(2):109–116. |
| first_indexed | 2024-03-07T19:07:59Z |
| format | Article |
| id | doaj.art-ffaeade49ac64b05a65ad8170e335a59 |
| institution | Directory Open Access Journal |
| issn | 2633-1462 |
| language | English |
| last_indexed | 2024-03-07T19:07:59Z |
| publishDate | 2024-02-01 |
| publisher | The British Editorial Society of Bone & Joint Surgery |
| record_format | Article |
| series | Bone & Joint Open |
| spelling | doaj.art-ffaeade49ac64b05a65ad8170e335a592024-03-01T06:37:37ZengThe British Editorial Society of Bone & Joint SurgeryBone & Joint Open2633-14622024-02-015210911610.1302/2633-1462.52.BJO-2023-0122How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysisLuke E. Corban0https://orcid.org/0009-0009-2561-1506Victor A. van de Graaf1https://orcid.org/0000-0001-5119-8887Darren B. Chen2https://orcid.org/0000-0003-1101-7871Jil A. Wood3https://orcid.org/0000-0001-6635-1661Ashish D. Diwan4https://orcid.org/0000-0003-1037-8421Samuel J. MacDessi5https://orcid.org/0000-0002-1578-7614Sydney Knee Specialists, Sydney, AustraliaSydney Knee Specialists, Sydney, AustraliaSydney Knee Specialists, Sydney, AustraliaSydney Knee Specialists, Sydney, AustraliaUniversity of NSW, Medicine and Health, St George and Sutherland Campus, St George Hospital Clinical School, Sydney, AustraliaSydney Knee Specialists, Sydney, AustraliaAims: While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. Methods: A retrospective cohort study was undertaken of 700 primary MA TKAs (643 patients) performed between 2014 and 2017. Lateral distal femoral and medial proximal tibial angles were measured pre- and postoperatively to calculate the arithmetic hip-knee-ankle angle (aHKA), JLO, and Coronal Plane Alignment of the Knee (CPAK) phenotypes. The primary outcome was the magnitude and direction of aHKA, JLO, and CPAK alterations. Results: The mean aHKA and JLO increased by 0.1° (SD 3.4°) and 5.8° (SD 3.5°), respectively, from pre- to postoperatively. The most common phenotypes shifted from 76.3% CPAK Types I, II, or III (apex distal JLO) preoperatively to 85.0% IV, V, or VI (apex horizontal JLO) postoperatively. The proportion of knees with apex proximal JLO increased from 0.7% preoperatively to 11.1% postoperatively. Among all MA TKAs, 60.0% (420 knees) were changed from their constitutional alignments into CPAK Type V, while 40.0% (280 knees) either remained in constitutional Type V (5.0%, 35 knees) or were unintentionally aligned into other CPAK types (35.0%; 245 knees). Conclusion: Fixed MA targets in TKA lead to substantial changes from constitutional alignment, primarily a significant increase in JLO. These findings enhance our understanding of alignment alterations resulting from both unintended changes to knee phenotypes and surgical resection imprecision. Cite this article: Bone Jt Open 2024;5(2):109–116.https://online.boneandjoint.org.uk/doi/epdf/10.1302/2633-1462.52.BJO-2023-0122total knee arthroplastymechanical alignmentjoint line obliquitycpakconstitutional alignmentkneesjoint line obliquitytotal knee arthroplasty surgerycoronal alignmentmedial proximal tibial angleship-knee-ankle angledistal femoralsurgical resectionlimb alignmentretrospective cohort study |
| spellingShingle | Luke E. Corban Victor A. van de Graaf Darren B. Chen Jil A. Wood Ashish D. Diwan Samuel J. MacDessi How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis Bone & Joint Open total knee arthroplasty mechanical alignment joint line obliquity cpak constitutional alignment knees joint line obliquity total knee arthroplasty surgery coronal alignment medial proximal tibial angles hip-knee-ankle angle distal femoral surgical resection limb alignment retrospective cohort study |
| title | How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis |
| title_full | How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis |
| title_fullStr | How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis |
| title_full_unstemmed | How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis |
| title_short | How often do we alter constitutional limb alignment, joint line obliquity, and Coronal Plane Alignment of the Knee (CPAK) phenotype when performing mechanically aligned TKA?: a large single-institution retrospective radiological analysis |
| title_sort | how often do we alter constitutional limb alignment joint line obliquity and coronal plane alignment of the knee cpak phenotype when performing mechanically aligned tka a large single institution retrospective radiological analysis |
| topic | total knee arthroplasty mechanical alignment joint line obliquity cpak constitutional alignment knees joint line obliquity total knee arthroplasty surgery coronal alignment medial proximal tibial angles hip-knee-ankle angle distal femoral surgical resection limb alignment retrospective cohort study |
| url | https://online.boneandjoint.org.uk/doi/epdf/10.1302/2633-1462.52.BJO-2023-0122 |
| work_keys_str_mv | AT lukeecorban howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis AT victoravandegraaf howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis AT darrenbchen howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis AT jilawood howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis AT ashishddiwan howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis AT samueljmacdessi howoftendowealterconstitutionallimbalignmentjointlineobliquityandcoronalplanealignmentofthekneecpakphenotypewhenperformingmechanicallyalignedtkaalargesingleinstitutionretrospectiveradiologicalanalysis |