High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge

Abstract Background In-silico and in-vitro studies have revealed an appropriate posterior tibial slope (PTS) is critical for normal anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tension and knee biomechanical behavior of unicompartmental knee arthroplasty (UKA). However, the...

Full description

Saved in:
Bibliographic Details
Main Authors: Nan Zheng, Chunjie Xia, Huiyong Dai, Diyang Zou, Yubin Long, Zhiyong Hou, Qi Wang, Tsung-Yuan Tsai
Format: Article
Language:English
Published: BMC 2025-04-01
Series:BMC Musculoskeletal Disorders
Subjects:
Online Access:https://doi.org/10.1186/s12891-025-08335-2
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850172375584210944
author Nan Zheng
Chunjie Xia
Huiyong Dai
Diyang Zou
Yubin Long
Zhiyong Hou
Qi Wang
Tsung-Yuan Tsai
author_facet Nan Zheng
Chunjie Xia
Huiyong Dai
Diyang Zou
Yubin Long
Zhiyong Hou
Qi Wang
Tsung-Yuan Tsai
author_sort Nan Zheng
collection DOAJ
description Abstract Background In-silico and in-vitro studies have revealed an appropriate posterior tibial slope (PTS) is critical for normal anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tension and knee biomechanical behavior of unicompartmental knee arthroplasty (UKA). However, the effects of PTS on in-vivo elongation of ACL and PCL in UKA remains unknown. The study aimed to quantify in-vivo ACL and PCL elongations during lunge and analyze their relations with PTS. Methods Thirteen fixed-bearing (FB) and 11 mobile-bearing (MB) UKA patients were recruited. The postoperative medial PTS was defined as the angle between the tibial transverse plane (perpendicular to mechanical axis) and cut plane. Accurate knee spatial postures of UKA and contralateral native knees during single-leg lunge were measured by the dual fluoroscopic imaging system. The ACL (AM, PL bundles) and PCL (AL, PM bundles) footprints were determined based on anatomical features on femoral and tibial 3D surface model reconstructed from CT. A validated 3D wrapping method was used to measure ligament bundle length. The paired Wilcoxon signed-rank test was used to analyze the ligament elongation difference between bilateral knees. The Spearman correlation between PTS and average ligament elongation difference (ACL during 0–30° early-flexion, PCL during 60–100° deep-flexion) was calculated. Results The elongation of FB UKA PCL double-bundle was larger than contralateral sides in most flexion range of lunge (Max-Difference: AL 7.6 ± 8.7%, PM 8.2 ± 5.1%, p < 0.05). In contrast, ACL double-bundle elongations of MB UKA in mid-flexion were larger than contralateral sides (Max-Difference: AM 8.0 ± 8.1%, PL 7.6 ± 9.8%, p < 0.05). The increased PTS was significantly relevant to the increased ACL double-bundle elongation difference of bilateral knees for both FB and MB UKA patients (R > 0.6, p < 0.05). Conclusion There was abnormal in-vivo elongation of PCL in FB UKA and ACL in MB UKA during lunge and cause over-constraints to the contralateral knee. There was a positive correlation between PTS and ACL elongation difference for both FB and MB UKA, indicating excessive PTS should be avoided to preserve native ACL function in further UKA implantation. Levels of Evidence III.
format Article
id doaj-art-000029be378143349e7376da1908bc2c
institution OA Journals
issn 1471-2474
language English
publishDate 2025-04-01
publisher BMC
record_format Article
series BMC Musculoskeletal Disorders
spelling doaj-art-000029be378143349e7376da1908bc2c2025-08-20T02:20:06ZengBMCBMC Musculoskeletal Disorders1471-24742025-04-0126111210.1186/s12891-025-08335-2High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lungeNan Zheng0Chunjie Xia1Huiyong Dai2Diyang Zou3Yubin Long4Zhiyong Hou5Qi Wang6Tsung-Yuan Tsai7School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong UniversitySchool of Mechanical Engineering, Shanghai Jiao Tong UniversityDepartment of Orthopedics, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University School of MedicineSchool of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong UniversityDepartment of Orthopaedics Surgery, Third Hospital of Hebei Medical UniversityDepartment of Orthopaedics Surgery, Third Hospital of Hebei Medical UniversityDepartment of Orthopedics, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University School of MedicineSchool of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong UniversityAbstract Background In-silico and in-vitro studies have revealed an appropriate posterior tibial slope (PTS) is critical for normal anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tension and knee biomechanical behavior of unicompartmental knee arthroplasty (UKA). However, the effects of PTS on in-vivo elongation of ACL and PCL in UKA remains unknown. The study aimed to quantify in-vivo ACL and PCL elongations during lunge and analyze their relations with PTS. Methods Thirteen fixed-bearing (FB) and 11 mobile-bearing (MB) UKA patients were recruited. The postoperative medial PTS was defined as the angle between the tibial transverse plane (perpendicular to mechanical axis) and cut plane. Accurate knee spatial postures of UKA and contralateral native knees during single-leg lunge were measured by the dual fluoroscopic imaging system. The ACL (AM, PL bundles) and PCL (AL, PM bundles) footprints were determined based on anatomical features on femoral and tibial 3D surface model reconstructed from CT. A validated 3D wrapping method was used to measure ligament bundle length. The paired Wilcoxon signed-rank test was used to analyze the ligament elongation difference between bilateral knees. The Spearman correlation between PTS and average ligament elongation difference (ACL during 0–30° early-flexion, PCL during 60–100° deep-flexion) was calculated. Results The elongation of FB UKA PCL double-bundle was larger than contralateral sides in most flexion range of lunge (Max-Difference: AL 7.6 ± 8.7%, PM 8.2 ± 5.1%, p < 0.05). In contrast, ACL double-bundle elongations of MB UKA in mid-flexion were larger than contralateral sides (Max-Difference: AM 8.0 ± 8.1%, PL 7.6 ± 9.8%, p < 0.05). The increased PTS was significantly relevant to the increased ACL double-bundle elongation difference of bilateral knees for both FB and MB UKA patients (R > 0.6, p < 0.05). Conclusion There was abnormal in-vivo elongation of PCL in FB UKA and ACL in MB UKA during lunge and cause over-constraints to the contralateral knee. There was a positive correlation between PTS and ACL elongation difference for both FB and MB UKA, indicating excessive PTS should be avoided to preserve native ACL function in further UKA implantation. Levels of Evidence III.https://doi.org/10.1186/s12891-025-08335-2Unicompartmental knee arthroplastyIn-vivo ligament elongationCruciate ligamentFluoroscopy2D-to-3D registration
spellingShingle Nan Zheng
Chunjie Xia
Huiyong Dai
Diyang Zou
Yubin Long
Zhiyong Hou
Qi Wang
Tsung-Yuan Tsai
High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
BMC Musculoskeletal Disorders
Unicompartmental knee arthroplasty
In-vivo ligament elongation
Cruciate ligament
Fluoroscopy
2D-to-3D registration
title High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
title_full High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
title_fullStr High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
title_full_unstemmed High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
title_short High posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early-flexion of lunge
title_sort high posterior tibial slope increases anterior cruciate ligament elongation in unicompartmental knee arthroplasty during early flexion of lunge
topic Unicompartmental knee arthroplasty
In-vivo ligament elongation
Cruciate ligament
Fluoroscopy
2D-to-3D registration
url https://doi.org/10.1186/s12891-025-08335-2
work_keys_str_mv AT nanzheng highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT chunjiexia highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT huiyongdai highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT diyangzou highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT yubinlong highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT zhiyonghou highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT qiwang highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge
AT tsungyuantsai highposteriortibialslopeincreasesanteriorcruciateligamentelongationinunicompartmentalkneearthroplastyduringearlyflexionoflunge