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Romano F, Rossi R, Cottino U, Bruzzone M, Pirato F, Rosso F. Medial Congruent and Medial Pivot Inserts in Total Knee Arthroplasty: A Scoping Review. MEDICINA (KAUNAS, LITHUANIA) 2025; 61:844. [PMID: 40428802 PMCID: PMC12113639 DOI: 10.3390/medicina61050844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2025] [Revised: 03/30/2025] [Accepted: 04/09/2025] [Indexed: 05/29/2025]
Abstract
Background and Objectives: Total knee arthroplasty (TKA) is one of the most common medical procedures worldwide. However, 10 to 20% of patients are still dissatisfied despite implants and surgical technique advancements. Recently, several medial-stabilized TKAs have been developed in attempts to replicate the native kinematics of the knee. The aim of this scoping review on medial-stabilized TKA inserts-medial congruent (MC) and medial pivot (MP)-is to focus on their clinical outcomes and the role of the posterior cruciate ligament (PCL), aiming to systematically map the existing research and highlight current knowledge gaps. Materials and Methods: A search of the PubMed, Embase and Cochrane databases was performed to identify relevant studies on the kinematics and outcomes of medial pivot (MP) or medial congruent (MC) inserts. The following Mesh terms were used in combination with the Boolean operators "AND" and "OR": "total knee arthroplasty", "total knee replacement", "medial pivot", "medial congruence", "outcomes" and "kinematic". Original studies reporting on clinical outcomes assessed with validated patient-reported scales, surgical techniques and reoperation rates for any reason with a minimum follow-up of 18 months were included. Results: A total of 39 articles met the inclusion criteria, accounting for 6143 total knee replacements. The overall reoperation-free survivorship rate was 98.4% (6047 out of 6143 knees) at a weighted average follow-up of 6.3 years (range 1.5-15.2 years, SD 0.7). Both MP and MC inserts demonstrated good outcomes, with no differences between groups. Few studies evaluated the role of the PCL in MP and MC inserts, with no differences in terms of clinical outcomes between retaining and sacrificing the PCL. Conclusions: MS-TKA demonstrated good outcomes in the literature independently of the specific design (medial pivot or medial congruent). Different possible biases may be present when evaluating the outcomes of these inserts, including different types of alignment and soft tissue balancing philosophies.
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Affiliation(s)
- Francesco Romano
- Department of surgery, Università degli Studi di Torino, Via Po 8, 10100 Torino, Italy; (F.R.); (F.P.)
| | - Roberto Rossi
- AO Ordine Mauriziano, Department of Orthopaedics and Traumatology, University of Torino, Largo Turati 62, 10128 Torino, Italy; (R.R.); (U.C.); (M.B.)
| | - Umberto Cottino
- AO Ordine Mauriziano, Department of Orthopaedics and Traumatology, University of Torino, Largo Turati 62, 10128 Torino, Italy; (R.R.); (U.C.); (M.B.)
| | - Matteo Bruzzone
- AO Ordine Mauriziano, Department of Orthopaedics and Traumatology, University of Torino, Largo Turati 62, 10128 Torino, Italy; (R.R.); (U.C.); (M.B.)
| | - Francesco Pirato
- Department of surgery, Università degli Studi di Torino, Via Po 8, 10100 Torino, Italy; (F.R.); (F.P.)
| | - Federica Rosso
- AO Ordine Mauriziano, Department of Orthopaedics and Traumatology, University of Torino, Largo Turati 62, 10128 Torino, Italy; (R.R.); (U.C.); (M.B.)
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Fujii R, Takahashi T, Iguchi M, Takeshita K, Nakanishi K. Comparative outcomes of kinematically aligned TKA with medial stabilized design vs. mechanically aligned TKA with bi-cruciate stabilized design: A propensity score-matched analysis. J Orthop 2025; 63:196-200. [PMID: 40291606 PMCID: PMC12019026 DOI: 10.1016/j.jor.2025.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2025] [Accepted: 04/11/2025] [Indexed: 04/30/2025] Open
Abstract
Purpose Patient dissatisfaction after total knee arthroplasty (TKA) is often linked to altered knee kinematics and stability. This study compared the short-term clinical outcomes of kinematically aligned TKA (KA-TKA) and mechanically aligned TKA (MA-TKA) using bi-cruciate stabilized (BCS) implants. Methods In this propensity score-matched study, 60 patients who underwent either KA-TKA or MA-TKA (30 per group) with BCS implants were analyzed. Baseline characteristics, including age, sex, preoperative range of motion (ROM), and hip-knee-ankle alignment, were matched. ROM and clinical outcomes were evaluated preoperatively and at 1 year postoperatively using the 2011 Knee Society Score (KSS) subscales and Forgotten Joint Score-12 (FJS). Results At 1 year, the KA group achieved higher scores in KSS subscales for symptoms (23.2 vs. 20.0, p < 0.001), satisfaction (28.1 vs. 22.5, p < 0.001), functional activities (82.1 vs. 74.2, p = 0.011), and FJS (83.8 vs. 62.5, p < 0.001). No significant differences were observed in maximum extension, flexion, or KSS expectations. Conclusions KA-TKA demonstrated superior satisfaction and functional recovery than MA-TKA with BCS implants in the short term. These results suggested that KA-TKA, which reconstructs patient-specific alignment, may provide a more natural knee feel, leading to higher patient satisfaction compared to implant-driven BCS-TKA.
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Affiliation(s)
- Ryota Fujii
- Department of Orthopedic Surgery, Kobari General Hospital, Noda, Japan
- Department of Orthopedic Surgery, Nihon University Itabashi Hospital, Tokyo, Japan
| | - Tsuneari Takahashi
- Department of Orthopaedics, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Masaki Iguchi
- Department of Orthopedic Surgery, Miyazaki Prefectural Nobeoka Hospital, Nobeoka, Japan
| | - Katsushi Takeshita
- Department of Orthopaedics, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Kazuyoshi Nakanishi
- Department of Orthopedic Surgery, Nihon University Itabashi Hospital, Tokyo, Japan
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Anjiki K, Nakano N, Ishida K, Takayama K, Fujita M, Kamenaga T, Tsubosaka M, Kuroda Y, Hayashi S, Kuroda R, Matsumoto T. Comparison of short-term clinical results between modified kinematically-aligned and guided motion bicruciate stabilized total knee arthroplasty. ARTHROPLASTY 2024; 6:40. [PMID: 38961515 PMCID: PMC11223350 DOI: 10.1186/s42836-024-00257-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/22/2024] [Indexed: 07/05/2024] Open
Abstract
BACKGROUND Both kinematically-aligned (KA) total knee arthroplasty (TKA) and bicruciate stabilized (BCS) TKA aim to reproduce the physiological knee kinematics. In this study, we compared the femoro-tibial component rotational mismatch between patients who underwent modified KA-TKA and those who received guided-motion BCS-TKA, and its influence on the clinical outcomes. METHODS In this retrospective study, 77 consecutive patients were included and divided into two groups: subjects who underwent modified KA-TKA with Persona (KA Group; n = 42) and those who received BCS-TKA with JOURNEY II (BCS group; n = 35). Range of motion, the 2011 Knee Society Score (KSS), the rotational alignment of the femoral and tibial components, and the correlations between the rotational mismatch and the 2011 KSS subscales were examined. RESULTS The postoperative objective knee indicators (P = 0.0157), patient satisfaction (P = 0.0039) and functional activity scores (P = 0.0013) in the KA group were significantly superior to those in the BCS group 1 year postoperatively. There was no significant difference between the two groups observed in the rotational mismatch. In the BCS group, significant negative correlations were identified between the rotational mismatch and objective indicators, patient satisfaction, and functional activity scores but not in the KA group. CONCLUSIONS The short-term clinical results following KA-TKA showed superior objective knee indicators, patient satisfaction and functional activity scores. A negative correlation was observed between component rotational mismatch and the 2011 KSS subscales in the BCS group, compared to no relationship found between the two in the KA group. These findings suggested that KA-TKA has a relatively higher tolerance for rotational mismatch than BCS-TKA.
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Affiliation(s)
- Kensuke Anjiki
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Naoki Nakano
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Kazunari Ishida
- Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, 657-0068, Japan
| | - Koji Takayama
- Department of Orthopaedic Surgery, Takayama Orthopedic Clinic, Kobe, 654-0049, Japan
| | - Masahiro Fujita
- Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, 657-0068, Japan
| | - Tomoyuki Kamenaga
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Masanori Tsubosaka
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Yuichi Kuroda
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Shinya Hayashi
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Ryosuke Kuroda
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan
| | - Tomoyuki Matsumoto
- Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, 650-0017, Japan.
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Hernandez L, Shichman I, Christensen TH, Rozell JC, Meftah M, Schwarzkopf R. Comparing Outcomes of Bicruciate-Stabilized and Cruciate-Retaining Total Knee Arthroplasty. Clin Orthop Surg 2024; 16:66-72. [PMID: 38304221 PMCID: PMC10825256 DOI: 10.4055/cios22268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 01/23/2023] [Accepted: 02/13/2023] [Indexed: 02/03/2024] Open
Abstract
Background Bicruciate-stabilized (BCS) total knee arthroplasty (TKA) aims to restore normal kinematics by replicating the function of both cruciate ligaments. Conventional cruciate-retaining (CR) design in TKA has shown previous clinical success with lower complication rates. This study compared the patient-reported outcomes between the BCS and CR TKA designs. Methods This retrospective study examined patients who underwent primary TKA using a CR or a BCS implant. Patient demographics, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), and Forgotten Joint Score (FJS) were compared between two cohorts. Patient-reported outcome measures were analyzed using independent samples t-tests. Results There were no significant preoperative demographic differences between groups. The CR cohort (n = 756) had significantly higher average KOOS, JR Scores compared to the BCS cohort (n = 652) at 3 months (59.7 ± 3.8 vs. 53.0 ± 3.9, p < 0.001) and 2 years (62.6 ± 8.0 vs. 53.8 ± 6.7, p = 0.001) after TKA. Within the cohort, KOOS, JR delta differences were not significant for CR when comparing patient scores 3 months to 1 year after surgery. Meanwhile, the BCS patients did show significant delta improvement (4.1 ± 1.9, p = 0.030) when compared 3 months to 1 year after surgery. One year postoperatively, the BCS cohort (n = 134) showed a significantly higher average FJS score (49.5 ± 31.4, vs. 36.8 ± 28.5, p = 0.028) than the CR cohort (n = 203). Both cohorts displayed a significant difference in delta improvements within their respective cohort when measuring FJS from 3 months to 1 year, 2 years, and 3 years after surgery. Conclusions The CR cohort performed better on average, compared to the BCS cohort in measures of KOOS, JR scores at the 2-year follow-up. The BCS cohort performed marginally better regarding FJS only at 1-year follow-up.
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Affiliation(s)
- Lorena Hernandez
- Department of Orthopedic Surgery, NYU Langone Health, New York, NY, USA
| | - Ittai Shichman
- Department of Orthopedic Surgery, NYU Langone Health, New York, NY, USA
| | | | - Joshua C. Rozell
- Department of Orthopedic Surgery, NYU Langone Health, New York, NY, USA
| | - Morteza Meftah
- Department of Orthopedic Surgery, NYU Langone Health, New York, NY, USA
| | - Ran Schwarzkopf
- Department of Orthopedic Surgery, NYU Langone Health, New York, NY, USA
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Cinotti G, Ripani FR, Perciballi B, La Torre G, Giannicola G. Higher rates of fully preserved posterior cruciate ligament in total knee arthroplasty using a double tibial cut: a prospective randomized controlled trial. Knee Surg Relat Res 2024; 36:2. [PMID: 38200548 PMCID: PMC10777558 DOI: 10.1186/s43019-023-00208-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
PURPOSE In cruciate retaining total knee arthroplasty, posterior cruciate ligament damage may occur during tibial cutting. A prospective randomized study was conducted to investigate whether a novel tibial cutting technique was more effective than the currently used techniques. MATERIALS AND METHODS Patients undergoing cruciate retaining total knee arthroplasty were recruited in a prospective, randomized, controlled trial. In 25 patients (group 1) the tibial cut was performed using a double tibial cut technique; in 25 (group 2) and 25 (group 3) patients, the bone island and en bloc resection techniques were performed, respectively. Posterior cruciate ligament integrity and femoral rollback were assessed at the end of surgery. The Oxford Knee Score, WOMAC score and range of motion were assessed postoperatively. RESULTS Posterior cruciate ligament was completely preserved in 92% of patients in group 1 and in 64% in group 2 and 3, respectively (p = 0.03). The Oxford Knee Score and WOMAC scores did not differ between groups (p = 0.4). The mean knee flexion was 126.4°, 121.5° and 123.9° in groups 1, 2 and 3, respectively (p = 0.04). The femoral rollback at 120° flexion was 80.7%, 72.2% and 75.4% in groups 1, 2 and 3, respectively (p = 0.01). CONCLUSIONS The double cut technique preserves the posterior cruciate ligament at significantly higher rates than the bone island or en bloc resection techniques. Better posterior cruciate ligament preservation may improve the femoral rollback and knee flexion. LEVEL OF EVIDENCE Prospective randomized controlled trial, Level I.
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Affiliation(s)
- Gianluca Cinotti
- Department of Anatomical, Histological, Forensic Medicine and Orthopaedic Sciences, University La Sapienza, Piazzale Aldo Moro, Rome, Italy.
| | | | - Beatrice Perciballi
- Department of Anatomical, Histological, Forensic Medicine and Orthopaedic Sciences, University La Sapienza, Piazzale Aldo Moro, Rome, Italy
| | - Giuseppe La Torre
- Department of Public Health and Infectious Diseases, University La Sapienza, Piazzale Aldo Moro, Rome, Italy
| | - Giuseppe Giannicola
- Department of Anatomical, Histological, Forensic Medicine and Orthopaedic Sciences, University La Sapienza, Piazzale Aldo Moro, Rome, Italy
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Rossi SMP, Sangaletti R, Jannelli E, Bova D, Montagna A, Benazzo F. PCL preservation or sacrifice does not influence clinical outcomes and survivorship at mid-term follow-up of a J-curve CR total knee replacement with a medial congruent liner and a functional coronal alignment. Arch Orthop Trauma Surg 2024; 144:307-313. [PMID: 37612567 DOI: 10.1007/s00402-023-05033-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023]
Abstract
BACKGROUND In recent years, increasing interest has arisen for medial pivoting TKA implants, designed to mimic the physiological knee kinematics, maximizing the contact area on the medial compartment of the knee, increasing anterior-posterior stability, and contributing to a ball-in-socket effect that allows the posterior cruciate sacrifice without a post-CAM mechanism. The medial congruent liner works with a J-curve cruciate-retaining (CR) femur without a real ball-in-socket design. The aim of this study was to evaluate the clinical outcomes and survival of these implants, with or without PCL sparing, at a medium follow-up. METHODS Between October 2016 and October 2018, 165 TKRs were performed in 161 patients (69.2% females and 30.8% males) and prospectively followed. Mean follow-up was 72 ± 12 months. All surgeries were performed using an extramedullary device and the same prosthetic implant. Patients were matched in two groups: in 80 patients, the PCL was preserved; in 85 patients, the PCL was sacrificed with a reduction of the tibial slope. RESULTS The OKS and KSS improved in both groups. The difference between the two groups at the final follow-up was not statistically significant. Good-to-excellent clinical results according to the KSS were achieved in 93% of the knees in the PCP group and in 95% in the PCS group. At final follow-up, the Forgotten Joint Score (FJS) was 73.6 in the PCP group and 74.1 in the PCS group with no statistical difference between the two groups (P > 0.05). CONCLUSIONS TKA with a medially congruent insert, showed promising results at mid-term follow-up, PCL preservation or sacrifice did not affect the clinical outcomes and survival. Further follow-up will be needed to evaluate these results at long term.
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Affiliation(s)
- Stefano Marco Paolo Rossi
- Sezione di Chirurgia Protesica ad Indirizzo Robotico, Unità di Traumatologia dello Sport, UOC Ortopedia e Traumatologia, Fondazione Poliambulanza, Via Bissolati, 57, 25124, Brescia, Italy.
| | - Rudy Sangaletti
- Sezione di Chirurgia Protesica ad Indirizzo Robotico, Unità di Traumatologia dello Sport, UOC Ortopedia e Traumatologia, Fondazione Poliambulanza, Via Bissolati, 57, 25124, Brescia, Italy
| | - Eugenio Jannelli
- Clinica Ortopedica e Traumatologica, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Davide Bova
- U.O. Ortopedia e Traumatologia, Humanitas Mater Domini, Castellanza, Italy
| | - Alice Montagna
- Sezione di Chirurgia Protesica ad Indirizzo Robotico, Unità di Traumatologia dello Sport, UOC Ortopedia e Traumatologia, Fondazione Poliambulanza, Via Bissolati, 57, 25124, Brescia, Italy
- Clinica Ortopedica e Traumatologica, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Francesco Benazzo
- Sezione di Chirurgia Protesica ad Indirizzo Robotico, Unità di Traumatologia dello Sport, UOC Ortopedia e Traumatologia, Fondazione Poliambulanza, Via Bissolati, 57, 25124, Brescia, Italy
- IUSS, Istituto Universitario di Studi Superiori, Pavia, Italy
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Trepczynski A, Moewis P, Damm P, Schütz P, Dymke J, Hommel H, Taylor WR, Duda GN. Dynamic Knee Joint Line Orientation Is Not Predictive of Tibio-Femoral Load Distribution During Walking. Front Bioeng Biotechnol 2021; 9:754715. [PMID: 34820363 PMCID: PMC8607168 DOI: 10.3389/fbioe.2021.754715] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 01/23/2023] Open
Abstract
Some approaches in total knee arthroplasty aim for an oblique joint line to achieve an even medio-lateral load distribution across the condyles during the stance phase of gait. While there is much focus on the angulation of the joint line in static frontal radiographs, precise knowledge of the associated dynamic joint line orientation and the internal joint loading is limited. The aim of this study was to analyze how static alignment in frontal radiographs relates to dynamic alignment and load distribution, based on direct measurements of the internal joint loading and kinematics. A unique and novel combination of telemetrically measured in vivo knee joint loading and simultaneous internal joint kinematics derived from mobile fluoroscopy ("CAMS-Knee dataset") was employed to access the dynamic alignment and internal joint loading in 6 TKA patients during level walking. Static alignment was measured in standard frontal postoperative radiographs while external adduction moments were computed based on ground reaction forces. Both static and dynamic parameters were analyzed to identify correlations using linear and non-linear regression. At peak loading during gait, the joint line was tilted laterally by 4°-7° compared to the static joint line in most patients. This dynamic joint line tilt did not show a strong correlation with the medial force (R 2: 0.17) or with the mediolateral force distribution (pseudo R 2: 0.19). However, the external adduction moment showed a strong correlation with the medial force (R 2: 0.85) and with the mediolateral force distribution (pseudo R 2: 0.78). Alignment measured in static radiographs has only limited predictive power for dynamic kinematics and loading, and even the dynamic orientation of the joint line is not an important factor for the medio-lateral knee load distribution. Preventive and rehabilitative measures should focus on the external knee adduction moment based on the vertical and horizontal components of the ground reaction forces.
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Affiliation(s)
- Adam Trepczynski
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany
| | - Philippe Moewis
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany
| | - Philipp Damm
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany
| | - Pascal Schütz
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Jörn Dymke
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany
| | - Hagen Hommel
- Krankenhaus Märkisch-Oderland, Wriezen, Germany
- Medizinische Hochschule Brandenburg, Theodor Fontane, Neuruppin, Germany
| | | | - Georg N. Duda
- Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Julius Wolff Institute, Berlin, Germany
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Moewis P, Kaiser R, Trepczynski A, von Tycowicz C, Krahl L, Ilg A, Holz J, Duda GN. Patient-specific resurfacing implant knee surgery in subjects with early osteoarthritis results in medial pivot and lateral femoral rollback during flexion: a retrospective pilot study. Knee Surg Sports Traumatol Arthrosc 2021; 31:1247-1266. [PMID: 34601628 PMCID: PMC10050034 DOI: 10.1007/s00167-021-06749-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Metallic resurfacing implants have been developed for the treatment of early, small, condylar and trochlear osteoarthritis (OA) lesions. They represent an option for patients who do not fulfill the criteria for unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA) or are too old for biological treatment. Although clinical evidence has been collected for different resurfacing types, the in vivo post-operative knee kinematics remain unknown. The present study aims to analyze the knee kinematics in subjects with patient-specific episealer implants. This study hypothesized that patient-specific resurfacing implants would lead to knee kinematics close to healthy knees, resulting in medial pivot and a high degree of femoral rollback during flexion. METHODS Retrospective study design. Fluoroscopic analysis during unloaded flexion-extension and loaded lunge was conducted at > 12 months post-surgery in ten episealer knees, and compared to ten healthy knees. Pre- and post-operative clinical data of the episealer knees were collected using a visual analog scale (VAS), the EQ 5d Health, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaires. RESULTS A consistent medial pivot was observed in both episealer and healthy knees. Non-significant differences were found in the unloaded (p = 0.15) and loaded (p = 0.51) activities. Although lateral rollback was observed in both groups, it was significantly higher for the episealer knees in both the unloaded (p = 0.02) and loaded (p = 0.01) activities. Coupled axial rotation was significantly higher in the unloaded (p = 0.001) but not in the loaded (p = 0.06) activity in the episealer knees. Improved scores were observed at 1-year post-surgery in the episealer subjects for the VAS (p = 0.001), KOOS (p = 0.001) and EQ Health (p = 0.004). CONCLUSION At 12 month follow-up, a clear physiological knee kinematics pattern of medial pivot, lateral femoral rollback and coupled axial external femoral rotation during flexion was observed in patients treated with an episealer resurfacing procedure. However, higher femoral rollback and axial external rotation in comparison to healthy knees was observed, suggesting possible post-operative muscle weakness and consequent insufficient stabilization at high flexion.
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Affiliation(s)
- Philippe Moewis
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Julius Wolff Institute, Augustenburger Platz 1, 13353, Berlin, Germany.
| | - René Kaiser
- OrthoCentrum Hamburg, Hansastrasse 1-3, 20149, Hamburg, Germany
| | - Adam Trepczynski
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Julius Wolff Institute, Augustenburger Platz 1, 13353, Berlin, Germany
| | | | - Leonie Krahl
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Julius Wolff Institute, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Ansgar Ilg
- OrthoCentrum Hamburg, Hansastrasse 1-3, 20149, Hamburg, Germany
| | - Johannes Holz
- OrthoCentrum Hamburg, Hansastrasse 1-3, 20149, Hamburg, Germany
| | - Georg N Duda
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Julius Wolff Institute, Augustenburger Platz 1, 13353, Berlin, Germany
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