scholarly journals Radiographic and Clinical Evolution of the Oxford Unicompartmental Knee Arthroplasty

Author(s):  
Riccardo D'Ambrosi ◽  
Manuel J. de S.V. da Silva ◽  
João L. M. Moura ◽  
Ilaria Mariani ◽  
Luca D. Serrao ◽  
...  

AbstractThe aim of the study is to evaluate whether the use of the new instrumentation Microplasty (MP) improves component positioning and the reliability of the surgical technique, reducing the implant outliers from the recommended range and providing a more accurate resection, while avoiding insufficient or excessive tibial resection and clinical scores. We prospectively analyzed clinical and radiographic outcomes of three consecutive cohorts for a total of 227 implants at a minimum follow-up of 36 months. The first cohort consisted of 67 Oxford unicompartmental knee arthroplasty (OUKA), using the phase III (Ph-III). The second cohort consisted of 136 OUKA, with the MP instrumentation. The third cohort consisted of 24 hypoallergenic OUKA, using the MP instrumentation (TiNbN). Postoperative alignment of the knee in the coronal and sagittal plane was measured using radiographs. No clinical differences were found among the three groups (p > 0.05). A significant difference was found on the slope between Ph-III and MP (p = 0.0005). Moreover, a significant difference was found in tibial angle and in tibial slope in arthroplasty with femoral size small (S), compared with size medium (M) or large (Ly) (tibia varus/valugs angle: p = 0.0484; tibial slope: p = 0.04). Similar results were found between small (AA, A, B) tibial size and large (C, D, E, F) tibial size for tibial varus/valgus (p = 0.03) angle and tibial slope (p = 0.003). A significant difference was found between Ph-III and MP in tibial slope in patients with body mass index (BMI) ≥25 kg/m2 (p = 0.0003). A positive correlation was noted between the femoral and tibial sizes and the tibial angle and the slope, and a negative correlation between weight and the tibial slope; furthermore, a positive correlation was found between Oxford knee score and radiographic angles. The MP instrumentation seems to be effective in determining the tibial cut and, particularly, improving the tibial slope, compared with Ph-III. The tibial slope is directly affected by the weight and measurements of the components, regardless of the instruments or the number of pegs, while clinical outcomes are correlated with implant position. This prospective comparative study reflects level of evidence II.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guangzhong Yang ◽  
Xufeng Jiao ◽  
Qianli Li ◽  
Zheng Li ◽  
Shuai An ◽  
...  

Abstract Background Hybrid Oxford unicompartmental knee arthroplasty (OUKA) consists of cementless femoral prostheses and cemented tibial prostheses. Although a hybrid OUKA has been used in clinical practice, the clinical outcome has not been reported. The purpose of this study was to compare the short-term clinical outcomes and rate of residual bone cement extrusion between hybrid and cemented prostheses and analyse the possible reasons for differences between outcomes. Methods A total of 128 knees (118 patients) with end-stage osteoarthritis were included in this study, of which underwent consecutive operations using unicondylar Oxford phase 3 implants from July 2017 and September 2019 in our centre. Follow-up was performed at 6 weeks, 3 and 6 months, 1 year and every year after operation, and complications and changes in the Oxford knee score (OKS) were recorded. The OKS of the two groups was analysed by the generalized estimating equation approach. Prosthesis-based standard fluoroscopy was performed in a timely manner after each operation, and the rate of residual cement extrusion of the two groups was estimated using T-tests and a multivariate regression analysis. Results Excluding the cases that lost follow-up, a total of 120 knees (65 in hybrid group and 55 in cemented group) were included in the analysis. There was no statistically significant difference in patient characteristics between the two groups (p > 0.05). The average follow-up time was 23.4 months (and ranged from 12 to 38 months). As of the last follow-up, there were no complications, such as dislocation, fracture, prosthesis loosening and subsidence, but one patient in the cemented group experienced symptoms caused by residual loose cement. Postoperative OKS in both groups improved significantly (p < 0.001). There was no significant difference in the OKS at any point during the follow-up or in the improvement of the OKS between the two groups (p > 0.05). Residual cement was mainly extruded behind the tibial prosthesis. The rate of hybrid periprosthetic residual cement extrusion was significantly lower in the hybrid group than in the cemented group, and the difference was statistically significant (OR = 3.38; p = 0.014). Conclusions Hybrid OUKA is as effective as cemented OUKA in the short term after operation and can significantly reduce the residual cement extrusion rate around the tibial prosthesis.


2021 ◽  
Author(s):  
Jirayu Paugchawee ◽  
Chaturong Pornrattanamaneewong ◽  
Pakpoom Ruangsomboon ◽  
Rapeepat Narkbunnam ◽  
Keerati Chareancholvanich

Abstract Background: Oxford unicompartmental knee arthroplasty (OUKA) yields favorable outcomes in patients with medial compartmental knee osteoarthritis; however, it remains unknown whether cemented or cementless OUKA fixation delivers better outcomes in Asian population. Accordingly, this study aimed to investigate the complications, reasons for reoperation, and 5-year prosthesis survival compared between cemented and cementless OUKA in Thai patients.Methods: A total of 466 cemented and 36 cementless OUKA that were performed during 2011-2015 with a minimum follow-up of five years were included. With reoperation for any reason as the endpoint, Kaplan-Meier analysis was performed to compare 5-year implant survival between groups. Complications, reasons for reoperation, and 90-day morbidity and mortality were compared between groups. Cox proportional hazards model was used to identify independent predictors of implant survival.Results: There was no significant difference in 5-year implant survival between the cemented and cementless groups (96.4% vs. 94.4%, p=0.375). The mean implant survival time was 113.0±0.8 and 70.8±1.9 months in the cemented and cementless groups, respectively (p=0.383). The most common reason for reoperation was bearing dislocation, and only one patient had 90-day morbidity. There was no significant difference between groups for complications or reasons for reoperation. No independent predictors of implant survival were identified in multivariate analysis.Conclusions: OUKA was shown to be a safe and durable reconstructive procedure in Thai patients with medial compartmental knee osteoarthritis. There was no significant difference in implant survival between the cemented and cementless groups during the 5-year follow-up, and no independent predictors of implant survival were identified. Trial registration: Thai Clinical Trials Registry, TCTR20200427004. Registered 27 April 2020 – Retrospectively registered.


Author(s):  
Magaly Iñiguez ◽  
Roberto Negrín ◽  
Jaime Duboy ◽  
Nicolás O. Reyes ◽  
Rodrigo Díaz

AbstractUnicompartmental knee arthroplasty (UKA) represents 10% of knee arthroplasties. Advantages are better functional results, quicker recovery, shorter hospitalization time, and lower blood loss, among others. However, revision rates are larger than total knee arthroplasty. Among the most important factors that explain this are the implant position and alignment, and the correct surgical indication. Greater accuracy in the implant placement may improve clinical results and increase the rate of implant survival. The objective of this study is to evaluate the precision of the Navio robot-assisted system in the position and alignment of medial UKA compared with the conventional technique. This is an experimental pilot study. Twenty-six cadaveric models were randomized into 2 groups: Robot-Assisted surgery (R) and Conventional Surgery (C). Radiological study was performed pre- and post-surgery, evaluating the medial distal femoral angle (MDFA), medial proximal tibial angle (MPTA), tibial slope, tibiofemoral angle (TFA), sagittal femoral angle (SFA), and size of the femoral and tibial components. The main result measurement was the change in postoperative angulation. The results of this study are MDFA median of 1.07° (0.19–4.5) for group R and 0.12° (0.03–10.4) with a significant difference in variances; a Welch t-test of p = 0.013; and an MPTA of 1.28° (0.05–5.87) for R and 1.3°(0.08–14.1) for C with significantly different variances (p = 0.0064). Size of the femoral component has a difference of p < 0.05 between groups. No differences for dispersion of TFA nor for the size of the tibial component were observed. In conclusion, using robot-assisted UKA allows for greater accuracy in the positioning of the implants and in the prediction of the size of the femoral component.


2017 ◽  
Vol 5 (2_suppl2) ◽  
pp. 2325967117S0010
Author(s):  
Tolga Tüzüner ◽  
Ayşe Esin Uygur ◽  
Esra Çirçi ◽  
Murat Eren ◽  
Ziya Demirci

Purpose: Unicompartmental knee arthroplasty is developed for the treatment of unicompartment arthrosis. Participation of multi compartments to the disease and patello-femoral arthrosis classically form a contraindication for this surgery. Different opinions were reported in literature on this subject. In this study, the effects of the presence of patello-femoral arthrosis on post-operative clinical and functional outcomes and revision process were investigated. Method: Pre-operative magnetic resonance (MR) images of 52 patients undergone medial unicompartmental knee arthroplasty between the years of 2011-2016 who completed minimum 6 months of follow-up period were evaluated. According to the presence of patello-femoral arthrosis, patients were classified into groups as non-arthrosis, grade 1-2 and grade 3-4. Statistical comparison were performed on knee society score (KSS), functional knee society score (fKSS), Oxford knee score (OKS), visual analog scale (VAS) score and post-operative joint range of motion (ROM) results. Results: 24 of 52 patients had no patello-femoral arthrosis. 13 patients were diagnosed with grade 1-2 and 15 patients were diagnosed with grade 3-4 patello-femoral arthrosis. No statistically significant difference was observed in patello-femoral arthrosis groups in average post-operative KSS, fKSS, OKS, VAS values. No revision proceeding was demonstrated in regression analysis. Conclusion: The results obtained from this study demonstrated that patello-femoral arthrosis has no effect on clinical and functional results. Yet, it is also considered that there is no factor to affect the implant survival rate. Having that said, when the number of patients and relatively short follow-up periods are considered, it is our opinion that new studies are required in this matter. [Figure: see text]


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Roberto Negrín ◽  
Jaime Duboy ◽  
Nicolás O. Reyes ◽  
Maximiliano Barahona ◽  
Magaly Iñiguez ◽  
...  

Abstract Purpose To compare joint line restoration after unicompartmental knee arthroplasty (UKA) between conventional and robotic-assisted surgery. Previous studies have shown that joint line distalization can lead to higher failure rates. The hypothesis was that robotic-assisted UKA is associated with less femoral component distalization and a precise tibial cut, which allows a more anatomical restitution of the knee joint line. Methods Retrospective cohort study of patients undergoing medial or lateral UKA between May 2018 and March 2020. Preoperative and postoperative radiologic assessment of the joint line was performed by two observers, using three different methods, one for tibial slope and one for tibial resection. Robotic assisted UKA and conventional UKA groups were compared. Results Sixty UKA were included, of which 48 (77.42%) were medial. Robotic-assisted UKA were 40 (64.52%) and 22(35.48%) were conventional The distalization of the femoral component was higher in the conventional group despite the method of measurement used In both Weber methods, the difference was statistically different: Conventional 2.3 (0.9 to 5.6) v/s Robotic 1.5 (− 1.1 to 4.1) (p =0.0025*). A higher proportion of patients achieved a femoral component position ≤ two millimeters from the joint line using robotic-assisted UKA compared to the conventional technique . No statistical difference between robotic-assisted and conventional UKA was found in tibial resection and slope. Conclusion Robotic-assisted UKA shows a better rate of joint line restoration due to less femoral component distalization than conventional UKA. No difference was found in the amount of tibial resection between groups in this study. Level of evidence III


2015 ◽  
Vol 4 (4) ◽  
pp. 22-26
Author(s):  
Christopher Ironside ◽  
Simon Coffey ◽  
Guy Eslick ◽  
Rami Sorial

Introduction: Unicompartmental knee arthroplasty (UKA) can be used to treat medial compartment osteoarthritis of the knee. Some of these knees will eventually fail, and need to be revised. There is controversy about using UKA in younger patients as a definitive procedure or as a means to delay total knee arthroplasty (TKA) because the outcomes of subsequent revision surgery may be inferior to a primary TKA. Methods: We retrospectively reviewed a series of 46 revision TKA patients following failed UKA (UKA revisions) using functional outcomes questionnaires and compared the results with a cohort of age and gender matched primary TKA patients. Our hypothesis was that UKA revision surgery would be inferior to primary TKA surgery. Results: Data was collected on 33 knees after a mean follow-up period of five years. There was no significant difference in the Oxford Knee Score (33.7 vs 37.1, p = 0.09) or the Western Ontario and MacMasters Universities Arthritis Index (WOMAC) (24.8 vs. 19.1, p = 0.22). A subgroup analysis demonstrated that UKAs, which fail early, are more likely to produce an inferior outcome following revision surgery than those that survive more than five years. Discussion: We conclude that UKA can be used effectively in appropriately selected patients, as the functional outcome of their subsequent revision to TKA is not significantly inferior to a primary TKA.Keywords: unicompartmental knee arthroplasty, revision knee arthroplasty


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Feifan Lu ◽  
Yan Yan ◽  
Weiguo Wang ◽  
Qidong Zhang ◽  
Wanshou Guo

Abstract Purpose The argument that patellofemoral osteoarthritis (PFOA) is a contraindication to unicompartmental knee arthroplasty (UKA) remains to be resolved. The purpose of this study was to perform a meta-analysis to determine whether PFOA affects functional outcomes and survivorship after medial UKA. Methods A literature search was performed in PubMed, Medline, Cochrane Library and Web of science to identify studies published in English (the last search was updated on June 1, 2020). The primary outcome measure was the Oxford Knee Score (OKS), whereas the secondary outcomes included range of motion (ROM) and the revision rate. Patients with patellofemoral joint narrowing or cartilage lesions as assessed intraoperatively or by radiography were assigned to the PFOA group. Results A total of 8 studies involving 3504 patients and 3975 knees were included in this meta-analysis. No patients had a severe lateral patellar groove. The results showed that there was no significant difference in the OKS, revision rate and ROM between PFOA patients and patients without PFOA. Conclusions No significant difference in functional outcomes and survivorship was found between patients with and without PFOA. Patients with PFOA assessed by radiographs or intraoperatively but without a lateral patellar groove should be considered candidates for medial UKA.


2021 ◽  
Vol 10 (18) ◽  
pp. 4284
Author(s):  
Cheng-Pang Yang ◽  
Ying-Chieh Lai ◽  
Chen-Te Wu ◽  
Kung-Tseng Hung ◽  
Yi-Sheng Chan ◽  
...  

Unicompartmental knee arthroplasty (UKA) can achieve better kinematics and faster recovery than total knee arthroplasty. The Phase III Oxford UKA system has five sizes of femoral components to approximate the normal knee geometry. However, these different sizes may also induce problems, such as the misselection of component size. Different criteria have been proposed to predict the ideal size preoperatively. However, no single method can be applied universally. Therefore, this study aimed to develop a preoperative measurement using knee magnetic resonance imaging (MRI) to predict femoral component size. A total of 68 patients who underwent UKA were investigated from June 2019 to April 2020. 16 knees using a different MRI protocol were excluded. We developed an MRI measurement method to determine femoral size instead of gender- and height-based methods. The accuracy of different methods was compared using postoperative true lateral view radiographs. Three different kinds of gender- and height-based criteria, preoperative templating and intraoperative spoon measurement were compared. The accuracy of MRI measurement was 90.3%. Therefore, a significant difference was found between MRI measurements and all other methods, such as templating or gender- and height-based methods. In conclusion, the MRI measurement method can be concluded to accurately predict femoral component size in UKA. This method could be used regardless of different ethnic groups, individual knee geometry, or soft tissue tension.


Author(s):  
Antonio Klasan ◽  
Mei Lin Tay ◽  
Chris Frampton ◽  
Simon William Young

Abstract Purpose Surgeons with higher medial unicompartmental knee arthroplasty (UKA) usage have lower UKA revision rates. However, an increase in UKA usage may cause a decrease of total knee arthroplasty (TKA) usage. The purpose of this study was to investigate the influence of UKA usage on revision rates and patient-reported outcomes (PROMs) of UKA, TKA, and combined UKA + TKA results. Methods Using the New Zealand Registry Database, surgeons were divided into six groups based on their medial UKA usage: < 1%, 1–5%, 5–10%, 10–20%, 20–30% and > 30%. A comparison of UKA, TKA and UKA + TKA revision rates and PROMs using the Oxford Knee Score (OKS) was performed. Results A total of 91,895 knee arthroplasties were identified, of which 8,271 were UKA (9.0%). Surgeons with higher UKA usage had lower UKA revision rates, but higher TKA revision rates. The lowest TKA and combined UKA + TKA revision rates were observed for surgeons performing 1–5% UKA, compared to the highest TKA and UKA + TKA revision rates which were seen for surgeons using > 30% UKA (p < 0.001 TKA; p < 0.001 UKA + TKA). No clinically important differences in UKA + TKA OKS scores were seen between UKA usage groups at 6 months, 5 years, or 10 years. Conclusion Surgeons with higher medial UKA usage have lower UKA revision rates; however, this comes at the cost of a higher combined UKA + TKA revision rate that is proportionate to the UKA usage. There was no difference in TKA + UKA OKS scores between UKA usage groups. A small increase in TKA revision rate was observed for high-volume UKA users (> 30%), when compared to other UKA usage clusters. A significant decrease in UKA revision rate observed in high-volume UKA surgeons offsets the slight increase in TKA revision rate, suggesting that UKA should be performed by specialist UKA surgeons. Level of evidence III, Retrospective therapeutic study.


2021 ◽  
Vol 103-B (8) ◽  
pp. 1367-1372
Author(s):  
Kevin D. Plancher ◽  
Jasmine E. Brite ◽  
Karen K. Briggs ◽  
Stephanie C. Petterson

Aims The patient-acceptable symptom state (PASS) is a level of wellbeing, which is measured by the patient. The aim of this study was to determine if the proportion of patients who achieved an acceptable level of function (PASS) after medial unicompartmental knee arthroplasty (UKA) was different based on the status of the anterior cruciate ligament (ACL) at the time of surgery. Methods A total of 114 patients who underwent UKA for isolated medial osteoarthritis (OA) of the knee were included in the study. Their mean age was 65 years (SD 10). No patient underwent a bilateral procedure. Those who had undergone ACL reconstruction during the previous five years were excluded. The Knee injury Osteoarthritis Outcome Score Activities of Daily Living (KOOS ADL) function score was used as the primary outcome measure with a PASS of 87.5, as described for total knee arthroplasty (TKA). Patients completed all other KOOS subscales, Lysholm score, the Western Ontario and McMaster Universities Osteoarthritis Index, and the Veterans Rand 12-item health survey score. Failure was defined as conversion to TKA. Results Survivorship at ten years was 97% in both the ACL-deficient and ACL-intact groups. The mean survival was 16.1 years (95% confidence interval (CI) 15.3 to 16.8) for the ACL-deficient group and 15.6 years (95% CI 14.8 to 16.361) for the ACL-intact group (p = 0.878). At a mean of nine years (SD 3.5) in the ACL-deficient group, 32 patients (87%) reached the PASS for the KOOS ADL. In the ACL-intact group, at a mean of 8.6 years (SD 3) follow-up, 63 patients (85%) reached PASS for the KOOS ADL. There was no significant difference in the percentage of patients who reached PASS for all KOOS subscales and Lysholm between the two groups. Conclusion PASS was achieved in 85% of all UKAs for KOOS ADL, similar to reports for TKA. Fixed-bearing, medial, non-robotically-assisted UKA resulted in 97% survival at ten years in both the ACL-deficient and ACL-intact groups. There was no significant difference in all outcomes between the two groups. Understanding PASS will allow better communication between surgeons and patients to improve the surgical management of patients with single compartment OA of the knee. This study provides mid- to long-term data supporting the use of PASS to document outcomes following UKA. PASS was met in more than 85% of patients with no differences between ACL-deficient and ACL-intact knees at a mean follow-up of nine years. Cite this article: Bone Joint J 2021;103-B(8):1367–1372.


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