Federica Rosso1, Roberto Rossi1,2, Francesco Benazzo3,4, Matteo Ghiara5, Davide Edoardo Bonasia1, Stefano Marco Paolo Rossi6. 1. Dipartimento di ortopedia e Traumatologia Largo, AO Ordine Mauriziano, Turati 62, 10128, Turin, Italy. 2. Dipartimento di Scienze Chirurgiche, Università degli Studi di Torino, Via Po 8, 10100, Turin, Italy. 3. Sezione di Chirurgia Protesica ad Indirizzo Robotico-Unità di Traumatologia dello Sport, U.O Ortopedia e Traumatologia Fondazione Poliambulanza, Via Bissolati 57, Brescia, Italy. 4. IUSS, Istituto Universitario di Studi Superiori, Pavia, Italy. 5. Clinica Ortopedica e Traumatologia, Università degli Studi di Pavia Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 6. Sezione di Chirurgia Protesica ad Indirizzo Robotico-Unità di Traumatologia dello Sport, U.O Ortopedia e Traumatologia Fondazione Poliambulanza, Via Bissolati 57, Brescia, Italy. rossi.smp@gmail.com.
Abstract
BACKGROUND: Total knee arthroplasty (TKA) in major deformities with ligament insufficiency may require a higher constraint, with bone sacrifice and concerns about long-term survivorship. Mid-level constraint liners have been recently introduced, but few studies described their outcomes. The aim of this study is to evaluate the short to mid-term outcomes of a constrained postero-stabilized (CPS) insert for primary TKA in moderate to severe deformities. METHODS: All patients who underwent TKA using a CPS liner in two centers between 2015 and 2017 were included in the study. The indications were: (1) valgus deformity type 2-3 partially correctable; (2) severe varus deformity with varus thrust; (3) post-traumatic deformity with major ligamentous insufficiency and any case of intra-operative ligament insufficiency. Patients were evaluated according to the Knee Society Scoring System (KSS), the Hospital for Special Surgery score (HSS), the Western Ontario and Mc Master University (WOMAC) and the Oxford Knee score (OKS). X-rays were evaluated according to the Knee Society Roentgenographic Evaluation System. RESULTS: Forty-seven TKA were included, with an average age of 66.1 ± 10.3 years and an average follow-up of 68.4 ± 6 months. All patients demonstrated a moderate to severe pre-operative mediolateral instability. All the scores significantly improved (p < 0.0001). In 71.4% of cases, the outcomes were excellent or very good. There were no failures due to aseptic loosening but one failure due to a traumatic ligament rupture. The cumulative survivorship was 97.9% ± 2.1% at 84 months. CONCLUSIONS: This mid-range constraint total knee replacement demonstrated promising outcomes and survival at mid-term follow-up. LEVEL OF EVIDENCE: IV (case series).
BACKGROUND: Total knee arthroplasty (TKA) in major deformities with ligament insufficiency may require a higher constraint, with bone sacrifice and concerns about long-term survivorship. Mid-level constraint liners have been recently introduced, but few studies described their outcomes. The aim of this study is to evaluate the short to mid-term outcomes of a constrained postero-stabilized (CPS) insert for primary TKA in moderate to severe deformities. METHODS: All patients who underwent TKA using a CPS liner in two centers between 2015 and 2017 were included in the study. The indications were: (1) valgus deformity type 2-3 partially correctable; (2) severe varus deformity with varus thrust; (3) post-traumatic deformity with major ligamentous insufficiency and any case of intra-operative ligament insufficiency. Patients were evaluated according to the Knee Society Scoring System (KSS), the Hospital for Special Surgery score (HSS), the Western Ontario and Mc Master University (WOMAC) and the Oxford Knee score (OKS). X-rays were evaluated according to the Knee Society Roentgenographic Evaluation System. RESULTS: Forty-seven TKA were included, with an average age of 66.1 ± 10.3 years and an average follow-up of 68.4 ± 6 months. All patients demonstrated a moderate to severe pre-operative mediolateral instability. All the scores significantly improved (p < 0.0001). In 71.4% of cases, the outcomes were excellent or very good. There were no failures due to aseptic loosening but one failure due to a traumatic ligament rupture. The cumulative survivorship was 97.9% ± 2.1% at 84 months. CONCLUSIONS: This mid-range constraint total knee replacement demonstrated promising outcomes and survival at mid-term follow-up. LEVEL OF EVIDENCE: IV (case series).
Authors: Adolph V Lombardi; Keith R Berend; Joseph R Leith; Gerardo P Mangino; Joanne B Adams Journal: J Bone Joint Surg Am Date: 2007-10 Impact factor: 5.284