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Primary Constrained-condylar-knee Designs Outperform Posterior-stabilized and Cruciate-retaining Designs in High-grade Varus Osteoarthritic Knees During Short-term Follow-up: a Pilot Study

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Date 2022 Apr 29
PMID 35486158
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Abstract

Introduction: High-grade varus osteoarthrosis (OA) is characterized by a pronounced intra-articular varus deformity and associated insufficiency of the lateral ligamentous complex. When performing a total knee arthroplasty (TKA) in such a knee, traditionally the alignment is restored to neutral, and the medial soft tissue structures are released to compensate for the lateral laxity and balance the joint. However, another option would be to leave the medial soft tissues untouched and accept the lateral laxity but to compensate for it using an ML-stabilized constrained-condylar knee (CCK) design. Our aim was to prove our hypothesis that such knees would demonstrate better clinical stability and better functionality as well as subjective outcome scores.

Materials And Methods: We searched our bicenter database of 912 primary TKAs (from 2016 to 2019) for primary TKA patients with a preoperative varus alignment of > 8°. After inclusion, 60 patients were divided into three groups by implant design: CCK (n = 21), posterior-stabilized (PS) (n = 20) and cruciate-retaining (CR) (n = 19). Oxford Knee Score (OKS), Forgotten Joint Score (FJS), Knee Society Score (KSS), UCLA-activity score, ML instability scores and both radiographic and clinical data were compared between groups.

Results: ML stability was significantly better in CCK designs (86% grade 0) compared to CR (37% grade 0) (p = 0.004) but not PS (70% grade 0) designs. No grade II instability was present in CCK and PS implants compared to 16% of CR implants. KSS and UCLA-activity score were higher in CCK designs compared to PS (p = 0.027, p = 0.041) and CR designs (p < 0.001, p = 0.007). OKS and FJS were higher in CCK designs compared to CR (p = 0.025, p = 0.008) but not to PS.

Conclusion: The use of a CCK design to compensate for the lateral laxity in high-grade varus OA knees allowed to refrain from a medial release. CCK designs displayed improved clinical stability and better functionality as well as subjective outcome scores compared to less-constrained designs.

Citing Articles

Modern Total Knee Arthroplasty Bearing Designs and the Role of the Posterior Cruciate Ligament.

Movassaghi K, Patel A, Ghulam-Jelani Z, Levine B Arthroplast Today. 2023; 21:101130.

PMID: 37151403 PMC: 10160699. DOI: 10.1016/j.artd.2023.101130.

References
1.
Noyes F, Barber-Westin S, Hewett T . High tibial osteotomy and ligament reconstruction for varus angulated anterior cruciate ligament-deficient knees. Am J Sports Med. 2000; 28(3):282-96. DOI: 10.1177/03635465000280030201. View

2.
Chang A, Hayes K, Dunlop D, Hurwitz D, Song J, Cahue S . Thrust during ambulation and the progression of knee osteoarthritis. Arthritis Rheum. 2004; 50(12):3897-903. DOI: 10.1002/art.20657. View

3.
Thienpont E, Parvizi J . A New Classification for the Varus Knee. J Arthroplasty. 2016; 31(10):2156-60. DOI: 10.1016/j.arth.2016.03.034. View

4.
Bellemans J, Vandenneucker H, Vanlauwe J, Victor J . The influence of coronal plane deformity on mediolateral ligament status: an observational study in varus knees. Knee Surg Sports Traumatol Arthrosc. 2009; 18(2):152-6. DOI: 10.1007/s00167-009-0903-0. View

5.
Benjamin J . Component alignment in total knee arthroplasty. Instr Course Lect. 2006; 55:405-12. View