Anna-Katharina Calek1, Andreas Ladurner1, Lukas Jud1, Vilijam Zdravkovic1, Henrik Behrend2. 1. Department of Orthopaedic Surgery and Traumatology, Kantonsspital St. Gallen, Rorschacherstrasse 95, CH-9007, St. Gallen, Switzerland. 2. Department of Orthopaedic Surgery and Traumatology, Kantonsspital St. Gallen, Rorschacherstrasse 95, CH-9007, St. Gallen, Switzerland. henrik.behrend@kssg.ch.
Abstract
PURPOSE: Joint line orientation (JLO) plays an important role in total knee arthroplasty (TKA), but its influence on patient-reported outcomes (PROs) is unclear. The purpose of this study was to examine JLO impact as measured by the forgotten joint score (FJS-12). The hypothesis was that restoring the joint line (JL) parallel to the floor would influence joint awareness favorably, i.e., allow the patient to forget about the joint in daily living. METHODS: All computer-navigated primary TKAs using a cemented, cruciate-retaining (CR) design implanted between January 2018 and September 2019 were reviewed in this retrospective single-center analysis. Primary endpoints were: clinical [range of motion (ROM)], and patient-reported (FJS-12) and radiographical outcomes [tibia joint line angle (TJLA), hip knee axis (HKA), mechanical medial proximal tibia angle (mMPTA) as well as mechanical lateral distal femoral angle (mLDFA)]. RESULTS: Seventy-six patients (mean age: 70.3 ± 9.7 years, mean BMI: 29.7 ± 5.2 kg/m2) were included. Postoperative ROM averaged 118.7 ± 9.6°. The mean FJS-12 improved from 16.4 ± 15.3 (preoperatively) to 89.4 ± 16.9 (1-year follow-up; p < 0.001). Clinical outcomes and PROs did not correlate with JLO (p = n.s.). Cluster analysis using six measures revealed that a medially opened TJLA was associated with significantly better postoperative FJS-12. CONCLUSION: Tibial JLO was found to have no effect on PROs. Considering the JLO in the coronal plane alone probably has questionable clinical relevance. Lower limb alignment should be assessed in all three planes and correlated with the clinical outcome. LEVEL OF CLINICAL EVIDENCE: Level IV.
PURPOSE: Joint line orientation (JLO) plays an important role in total knee arthroplasty (TKA), but its influence on patient-reported outcomes (PROs) is unclear. The purpose of this study was to examine JLO impact as measured by the forgotten joint score (FJS-12). The hypothesis was that restoring the joint line (JL) parallel to the floor would influence joint awareness favorably, i.e., allow the patient to forget about the joint in daily living. METHODS: All computer-navigated primary TKAs using a cemented, cruciate-retaining (CR) design implanted between January 2018 and September 2019 were reviewed in this retrospective single-center analysis. Primary endpoints were: clinical [range of motion (ROM)], and patient-reported (FJS-12) and radiographical outcomes [tibia joint line angle (TJLA), hip knee axis (HKA), mechanical medial proximal tibia angle (mMPTA) as well as mechanical lateral distal femoral angle (mLDFA)]. RESULTS: Seventy-six patients (mean age: 70.3 ± 9.7 years, mean BMI: 29.7 ± 5.2 kg/m2) were included. Postoperative ROM averaged 118.7 ± 9.6°. The mean FJS-12 improved from 16.4 ± 15.3 (preoperatively) to 89.4 ± 16.9 (1-year follow-up; p < 0.001). Clinical outcomes and PROs did not correlate with JLO (p = n.s.). Cluster analysis using six measures revealed that a medially opened TJLA was associated with significantly better postoperative FJS-12. CONCLUSION: Tibial JLO was found to have no effect on PROs. Considering the JLO in the coronal plane alone probably has questionable clinical relevance. Lower limb alignment should be assessed in all three planes and correlated with the clinical outcome. LEVEL OF CLINICAL EVIDENCE: Level IV.
Authors: Michael T Hirschmann; Silvan Hess; Henrik Behrend; Felix Amsler; Vincent Leclercq; Lukas B Moser Journal: Knee Surg Sports Traumatol Arthrosc Date: 2019-04-09 Impact factor: 4.342
Authors: Michael T Hirschmann; Lukas B Moser; Felix Amsler; Henrik Behrend; Vincent Leclercq; Silvan Hess Journal: Knee Surg Sports Traumatol Arthrosc Date: 2019-04-12 Impact factor: 4.342
Authors: Silvan Hess; Lukas B Moser; Felix Amsler; Henrik Behrend; Michael T Hirschmann Journal: Knee Surg Sports Traumatol Arthrosc Date: 2019-04-15 Impact factor: 4.342
Authors: Michael T Hirschmann; Lukas B Moser; Felix Amsler; Henrik Behrend; Vincent Leclerq; Silvan Hess Journal: Knee Surg Sports Traumatol Arthrosc Date: 2019-04-11 Impact factor: 4.342
Authors: Stephen M Howell; Stacey J Howell; Kyle T Kuznik; Joe Cohen; Maury L Hull Journal: Clin Orthop Relat Res Date: 2012-09-21 Impact factor: 4.176