| 114
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Randomized Clinical Trial |
Period and recruited population: Between January 1999 and December 2001, 91 patients (104 knees) were recruited for the study. One patient had different arthroplasties implanted in each knee.
Preoperative diagnoses and previous surgical procedures: The preoperative diagnosis was primary osteoarthritis in all cases, except for two (one case of osteonecrosis and one of rheumatoid arthritis). Previous surgeries included arthroscopic procedures, medial meniscectomies, and, in one case, anterior cruciate ligament (ACL) reconstruction.
Excluded population: Patients with prior tibial plateau fracture or knee osteotomy were excluded. Chondrocalcinosis was not considered a contraindication, and no patients were excluded based on excess weight.
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight):
St. George Group (Fixed-Bearing): 57 knees in 49 patients; Mean age: 66.7 years; 29 males and 20 females; 26 right knees, 31 left knees; Mean body weight: 83.0 kg
Oxford Group (Mobile-Bearing): 47 knees in 43 patients; Mean age: 64.7 years; 26 females, 17 males; 25 right knees, 22 left knees; Mean body weight: 77.7 kg
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Types of prostheses used: Mobile-Bearing Unicompartmental Knee Prosthesis (Oxford) and the Fixed-Bearing Unicompartmental Knee Prosthesis (St. George).
Clinical indications for surgery: The indications for unicompartmental knee prosthesis were: Incapacitating knee pain with medial compartmental disease; Intact anterior cruciate ligament (ACL) and collateral ligaments; Fixed flexion deformity less than 108 degrees; Minimal subluxation; and correctable varus deformity less than 108 degrees.
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Comparison proposed by the work: The complications and clinical outcomes of the St. Georg Sled, a fixed-bearing unicompartmental knee prosthesis, with the mobile-bearing Oxford unicompartmental knee prosthesis over a two-year postoperative period.
Assessment tools and time of evaluation (preoperative, postoperative, or both): The Bristol Knee Score (BKS) and Oxford Knee Score were used to assess knee function preoperatively, at 8 months, and 2 years postoperatively. Preoperative weight, range of motion, and knee scores for each group were the variables studied. No patients were lost in follow-up, and 88 out of 91 patients attended the 2-year postoperative evaluation.
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Função:
Bristol Knee Score and Oxford Knee Score: At the 2-year follow-up, both socres showed better outcomes for the St. Georg Sled Group (fixed-bearing). There were also more excellent and good results in the St. Georg Sled Group. However, there was no significant difference compared to the Oxford Group (mobile-bearing).
Mean 2 years after post-op Bristol knee score
FB / MB
89 / 84.1
Mean 2 years after post-op Oxford
score
FB / MB
36.5 / 33.4
Mean total pain score (component of Bristol knee score, max=40)
FB / MB
34.9 / 30.7
Mean total function score (component of Bristol knee score, max=27)
FB / MB
23 / 22
Mean of flexion post-op (range of motion)
FB / MB
121.68 / 118.68
Pain:
The pain component of the Bristol Knee Score was significantly better for the St. Georg Sled Group, fixed-bearing (p-value = 0.013).
Postoperative complications and revisions: In the Oxford Group (mobile-bearing), three patients experienced bearing dislocation, and four patients required revisions with an average revision time of 3 years. In the St. Georg Sled Group (fixed-bearing), three patients required revisions with an average revision time of 3.4 years.
Comparative conclusions on quality of life: These results demonstrate that, in the short term, the Oxford mobile-bearing prosthesis has a higher reoperation rate, while the fixed-bearing St. George sled prosthesis achieves better pain relief. The functional scores of both groups were similar.
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| 215
|
Randomized Clinical Trial |
Period and recruited population: Between February 1996 and December 1997, 40 patients who underwent medial unicompartmental knee arthroplasty were recruited and randomly divided into two groups.
Preoperative diagnoses and previous surgical procedures:
Primary osteoarthritis Excluded population:
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight):
Group A - 20 knees in 20 patients; mean age 69.5 years; 8 males and 12 females; 11 left knees; 9 right knees.
Group B - 20 knees in 20 patients; mean age 71 years; 11 males and 9 females; 8 left knees; 12 right knees.
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Types of prostheses used:
Group A -Allegretto, Centerpulse, Baar, Switzerland (Fixed-bearing) and Group B - - AMC-Unicondylar-Knie-Prothese, Alphanorm, Quiershied, Alemanha (Mobile bearing)
Clinical indications for surgery:
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Comparison proposed by the work:
Pre- and postoperative follow-up with clinical and statistical evaluations using scores, with an average postoperative follow-up period of 5.7 years.
Assessment tools and time of evaluation (preoperative, postoperative, or both): The patients were evaluated preoperatively by two independent orthopedists who were not involved in the surgical procedure and were blinded to the type of prosthesis implanted. Additionally, the Knee Society scoring instrument, the G.I.U.M. (Unicompartmental Knee Prosthesis Outcome Score developed by the Italian Orthopaedic UKR’s Users Group), and the Functionality Score were used for comparison..
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Function:
Both in the preoperative and at the last follow-up consultation, no statistically significant differences were detected between the two groups according to the GIUM Score, the Knee Society Score, or the functional evaluation of the patients.
Group A: pre / post
Knee Society: 44,6 / 87.5
Functional: 48.7 / 76.3
GIUM: 51.3 / 73.8
Group B: pre / post
Knee Society: 48.3 / 88.05
Functional: 48.7 / 77.0
GIUM: 52.4 / 75.5
Pain:
Postoperative complications and revisions:
After 18 months, one patient in Group A underwent a revision of the prosthesis due to persistent pain in the tibial component region, with only partial reduction of the pain complaint after the procedure. In one patient from Group B, an intraoperative medial tibial plateau fracture occurred, which was treated with screw fixation before implantation of the tibial component and did not affect the final outcome or postoperative follow-up. One patient with the fixed component had a TVP, but the condition was treated without complications.
There were no cases of superficial or deep infections.
Comparative conclusions on quality of life:
These results demonstrated that despite more extensive usage, it was not possible to detect advantages of the mobile-bearing prosthesis over the fixed-bearing prosthesis in terms of clinical performance and longevity.
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| 316
|
Randomized Clinical Trial |
Period and recruited population:
Between May 2001 and June 2003, 56 knees in 48 patients, 34 males, 14 females, with a mean age of 72 years and a diagnosis of osteoarthritis were randomly assigned to two groups for knee arthroplasty.
Preoperative diagnoses and previous surgical procedures:
Non-inflammatory osteoarthritis of the medial compartment and/or mechanical deformity.
Excluded population:
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight):
Fixed-Bearing Group (Miller/Galante, Zimmer, Warsaw, USA): 28 knees:
19 males, 9 females; Mean age:
70 years; Mean BMI: 27.6
Mobile-Bearing Group (Oxford, Biomet, UK): 28 knees: 20 males, 8 females; Mean age: 74 years; Mean BMI: 26.5
Eight patients received bilateral implants (always with one knee receiving an Oxford implant and the other receiving a Miller/Galante implant).
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Types of prostheses used:
Fixed bearing (Miller/Galante, Zimmer, Warsaw, USA Mobile bearing (Oxford, Biomet, UK)
Clinical indications for surgery:
Non-inflammatory osteoarthritis of the medial compartment, mechanical axial deformity <10° varus or 5° valgus; intact ACL without medial-lateral subluxation; Flexion contracture <15°; Body weight <90 kg.
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Comparison proposed by the work:
Comparison of fixed-bearing and mobile-bearing knee prostheses, with a focus on knee kinematics, tibial component radiolucency, and clinical follow-up over a period of 2 years.
Assessment tools and time of evaluation (preoperative, postoperative, or both):
The comparison was conducted based on the following three criteria:
Kinematic:
1) Internal rotation of the tibia relative to the femur.
2) Anterior-posterior translation of the medial femoral condyle.
3) Anterior-posterior translation of the contact point.
4) Movement of the mobile-bearing.
Radiographic:
Comparison of postoperative radiographs immediately after the procedure with those taken after 2 years.
Alignment assessed through the Hip-Knee-Ankle (HKA) angle.
Radiolucency at the bone-implant interface.
Progression of osteoarthritis in the patellofemoral joint and the lateral component.
Positioning and alignment of the tibial and femoral components.
Clinical:
Independent observers evaluated preoperatively and annually during follow-up using scores such as Knee Society Scores, WOMAC, and SF-36
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Function:
The mobile-bearing prosthesis showed a closer approximation to the normal knee kinematics, with greater and more consistent tibial internal rotation, a more stationary medial femoral condyle, and rollback of the lateral femoral condyle.
It also presented a lower incidence of radiolucency (with increased radiolucency being a possible sign that the fixation quality may be compromised in this group, though longer follow-up time is necessary to confirm this fact).
Fixed / Mobile
Range of motion: 110 (85–140) / 112 (90–135)
Knee score: 91 / 89
Function score 84 / 85
Pain: After 2 years
Fixed / Mobile
46 / 44
SF-36 score
Preoperative physical: 27 / 29
2 years, physical 37 / 40
2 years, mental 52 / 50
Womac score
Pre 46 / 54
2 years 74 / 79
Postoperative complications and revisions:
Two patients with a mobile-bearing prosthesis require prosthesis revision before two years: one due to infection and the other due to aseptic loosening of the tibial component.
Two patients with 3 prostheses (one mobile-bearing and two fixed-bearing) died from unrelated causes before two years. They were excluded from the final comparison but included in the initial study data.
Comparative conclusions on quality of life:
Both SF-36, Womac, and Knee Society scores improved during the two-year follow-up period with no significant differences between the two groups.
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| 417
|
Randomized Clinical Trial |
Period and recruited population:
Between October 2010 and December 2012, a total of 139 participants were recruited.
Preoperative diagnoses and previous surgical procedures:
Excluded population: Patients with ligament insufficiency, inflammatory arthritis, deformity requiring augmentation, neuromotor diseases, pathologies of the feet, ankles, hips, or contralateral knee causing significant pain or gait alteration, as well as those requiring total knee replacement.
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight): Dividided into two groups:
Fixed-Bearing Group: 69 initial participants; 64 underwent the procedure; 58 were followed for 2 years; 32 males and 26 females; Mean age of 61.8 years
Mobile-Bearing Group: 70 initial participants; 65 underwent the procedure; One patient crossed over from the other group; 54 were followed for 2 years; 28 males and 26 females; Mean age of 62.6 years; Two patients were not followed due to the need for total knee replacement revision.
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Types of prostheses used:
Fixed-Bearing: Surgical technique assisted by a robotic arm using the RESTORIS MCK (MAKO Surgical Corp, Fort Lauderdale, FL) with the MAKO Robotic-Arm Interactive Orthopedic system.
Mobile-Bearing: Conventional surgical technique using the Oxford Phase 3 (Biomet, Warsaw, IN) prosthesis.
Clinical indications for surgery:
Osteoarthritis of the medial compartment of the knee requiring surgery
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Comparison proposed by the work:
Unicompartmental knee prosthesis with robotic-assisted surgical technique and conventional prosthetic technique, performed by one of the three surgeon authors with at least 5 years of experience in independent practice.
Assessment tools and time of evaluation (preoperative, postoperative, or both):
For the comparison, several scores were used, including OKS (Oxford Knee Score), AKSS (American Knee Society Score), Forgotten Joint Score (FJS), Pain Catastrophizing Scale, Pain Visual Analog Scale, Stiffness Visual Analog Scale (SVAS), patient satisfaction, range of motion (ROM), and University of California Los Angeles (UCLA) Activity Scale. Complications and revisions over the 2-year period were also taken into account.
Data collection was performed by an associate/research nurse who was blinded to the group data at the investigative hospital.
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Function:
The SVAS was significantly higher in the manual group, while the ROM was greater in the robotic-assisted surgery group, and both remained consistent after 2 years of follow-up.
Pain: After 2 years
Mobile / Fixed
Pre: 55.1 / 52.7
After 2 years: 5.0 / 3.0
Postoperative complications and revisions:
From the mobile-bearing group, two patients were lost to follow-up due to the need for total prosthesis revision. Regarding the evaluation of survival differences (100% in the assisted group and 96.3% in the conventional group), long-term follow-up is necessary.
Comparative conclusions on quality of life:
At two years, no significant differences were detected by the study’s analysis tools. However, in the subgroup of patients with a preoperative University of California Los Angeles Activity Scale value >5, a higher postoperative mean of the Oxford Knee Score was observed after two years, indicating a possible greater benefit of robotic-assisted surgery for more active patients. Nevertheless, longer follow-up time is required to draw conclusive results.
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| 518
|
Randomized Clinical Trial |
Period and recruited population:
Between January 2014 and November 2015, a total of 62 patients were followed through stereometric analysis by radiography..
Preoperative diagnoses and previous surgical procedures:
Excluded population:
Patients with inflammatory arthritis, contralateral knee prosthesis, disseminated malignancy, severe systemic disease, female patients of childbearing age, and patients unable to provide written consent.
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight):
Mobile-Bearing Group (Oxford UKA): 33 patients, of which 2 did not undergo the procedure (due to no LCA); Mean age of 64 years; 16 males and 17 females; Mean BMI of 29
Fixed-Bearing Group (Sigma UKA): 32 patients, of which 1 did not undergo the procedure and 1 was excluded due to infection 5 weeks after the procedure; Mean age of 61 years; 17 males and 15 females; Mean BMI of 28.
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Types of prostheses used:
Mobile bearing (Oxford UKA)
Fixed bearing (Sigma UKA)
Clinical indications for surgery:
Patients above 18 years of age eligible for unicompartmental knee prosthesis according to the criteria established by Murray et al. (1998) and DePuy International (2009).
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Comparison proposed by the work:
The unicompartmental knee prostheses implanted by two experienced orthopedic surgeons using minimally invasive techniques. During the surgery, tantalum beads measuring 4-6 mm were implanted in the femoral and tibial periprosthetic regions for subsequent RSA.
Assessment tools and time of evaluation (preoperative, postoperative, or both):
Radiostereometric analysis (RSA) was performed on postoperative day one and subsequently at 4, 12, and 24 months. All RSA data were analyzed using the same system, and patients with fewer than 3 visible markers were excluded from the analysis.
In addition to RSA, the study also utilized the Oxford Knee Score and a general health questionnaire (RAND-36) to assess overall health. Furthermore, the strength of the thigh extensors was evaluated, with both lower limbs being tested preoperatively and again after 24 months.
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Function:
Oxford Knee Score
MB / FB
Pre: 26 / 28
4 months: 38 / 37
12 months: 42 / 41
24 months: 40 / 41
Pain: Após 2 anos
RAND-36
MB / FB
Pre: 65 (44) / 72 (38)
4 months: 77 (38) / 87 (32)
12 months: 85 (36) / 81 (34)
24 months: 87 (32) / 91 (23)
Postoperative complications and revisions:
Mobile-bearing: 02 patients did not undergo the procedure (absence of ACL).
Fixed-bearing: 01 patient did not undergo the procedure, and 01 patient was excluded due to infection 5 weeks after the procedure.
Comparative conclusions on quality of life: No statistically significant or clinically relevant differences were observed. There was recovery of function and strength of the extensor muscles, with no noted changes between the limbs after 24 months of follow-up, and good fixation was observed during the same period.
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| 619
|
Randomized Clinical Trial |
Period and recruited population: From September 2015 to February 2017, a prospective, randomized, parallel, and single-center study was conducted with 180 patients
Preoperative diagnoses and previous surgical procedures: Medial compartmental knee osteoarthritis was performed
Excluded population: (i) Patients with lateral compartment knee osteoarthritis, knee arthroplasty in the contralateral knee, inflammatory arthritis, and disseminated malignancies such as AIDS, syphilis, and hepatitis B; (ii) Severe systemic diseases, such as rheumatoid arthritis and malignancies; (iii) Revisional arthroplasty and postinfection cases; (iv) Female patients of childbearing age; (v) Patients unable to provide written informed consent.
Division of the comparison groups and characteristics of each group (sex, number of patients, mean
age, mean body weight):
78 men and 102 women, with an overall mean age of 63.3 ± 6.9 years, divided as follows:
MB: 60 patients, mean age of 63 years, mean BMI of 24
FB: 60 patients, mean age of 63 years, mean BMI of 24
TKA: 60 patients (data not used in this review as it concerns total knee replacement).
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Types of prostheses used:
Unicompartmental knee prosthesis with fixed or mobile bearing, or total knee arthroplasty.
Mobile: Oxford phase 3 MB UKA
Fixed: Link FB UKA
Total: Depuy Sigma PFC PFC TKA
Clinical indications for surgery:
The inclusion criteria were:
(i) Patients aged between 50 and 80 years at the time of recruitment, with clinical and radiographic evidence (including anteroposterior and lateral knee radiographs and knee computed tomography [CT]) of non-lateral compartment knee osteoarthritis, with Kellgren-Lawrence X-ray classification levels 2-4.
(ii) Competent and willing to participate in the study.
(iii) Absence of signs of any severe neurological disorders.
(iv) Provided informed consent for the treatment and testing program.
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Comparison proposed by the work:
A similar perioperative management and fast-track surgery program were implemented for all patients. Knee scores at the 3-year follow-up after the operation, as well as the clinical outcomes of these three patient groups, were recorded, investigated, and compared.
Various parameters were also recorded, investigated, and compared, including operative time, intraoperative bleeding, time to the first walk without crutches, independent stair ascent and descent after the operation, postoperative complications, and a series of knee scores.
Assessment tools and time of evaluation (preoperative, postoperative, or both):
The following scores were used:
Hospital for Special Surgery Knee Score (HSS)
Western Ontario and McMaster Universities Index (WOMAC)
Pontuação da Knee Society (KSS)
Visual Analog Scale (VAS)
Oxford Knee Score (OKS)
Maximum knee flexion angle
Forgotten Joint Score (FJS)
Follow up exceeding 36 months
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Function:
Overall, there was no significant difference in all knee scores and maximum knee flexion angles between the MB UKA and FB UKA groups.
Pain: After 3 years
WOMAC
Pre: MB - 47,5 / FB - 47.5
3 years: 91
VAS
Pre: MB - 9.0 / FB - 9.0
3 years: 1.0
Postoperative complications and revisions:
There was one case of the original dislocation of the bearing in the MB UKA group. In the FB UKA group, one patient had femoral component dislocation caused by a fall injury, and another patient lost their life in a car accident.
Comparative conclusions on quality of life:
This study indicates that there are no significant differences, with similar Knee Scores between patients with MB and FB. A randomized control study using radiostereometric analysis at the 2-year follow-up showed that both groups have good fixation of the tibial components and both demonstrate good clinical progress.
The groups also showed significant improvement in pain and function, evolving significantly up to 12 months postoperatively.
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| 720
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Randomized Clinical Trial |
Period and recruited population:
A total of 54 patients were recruited during the period from September 2015 to December 2019.
Preoperative diagnoses and previous surgical procedures:
Patients with idiopathic or secondary osteoarthritis of the medial femoral compartment of the knee.
Excluded population:
The exclusion criteria were: (1) age < 80 years; (2) revi sion arthroplasty; (3) previous surgery of the affected knee (except meniscectomy); (3) uncontrolled systemic disease; (5) patient unable to understand the nature of the present study
Division of the comparison groups and characteristics of each group (sex, number of patients, mean age, mean body weight):
FB PKA Persona Partial Knee (PPK)
group: 25 patients; mean age 82.3 ± 2.0; 23 women and 2 men.
MB PKA Oxford: 29 patients; mean age 81.9 ± 1.0; 25 women and 4 men.
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Types of prostheses used:
The first group received FB PKA Persona Partial Knee (PPK) ® (Zimmer Biomet, Warsaw, Indiana, USA);
The second received MB
PKA Oxford with Microplasty instrumentation (Zimmer Biomet, Warsaw, Indiana, USA).
Clinical indications for surgery:
Patients with idiopathic or secondary osteoarthritis of the medial femoral compartment of the knee; Varus or valgus deformity < 3°; Knee flexion > 100°; Flexion contracture < 10°; Integrity of cruciate and collateral ligaments.
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Comparison proposed by the work:
The patients were assessed at T0 (preoperative), T1 (1 year post-surgery), and T2 (3 years post-surgery).The hypothesis of the current study was that MB implants would perform better than FB implants in PKA in octogenarians.
Assessment tools and time of evaluation (preoperative, postoperative, or both):
Using visual analogue scale (VAS), Knee Society Score (KSS), and Oxford Knee Score (OKS). Additionally, data on implant survival and range of motion (ROM) were collected. Furthermore, the following radiographic parameters were measured: Varus/valgus of the femoral component; Varus/valgus of the tibial component; Anteroposterior slope.
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Function:
No difference between FB and MB in KSS, and OKS.
KSS
Pre: FB 37.3 ± 8.2 / MB 37.1 ± 9.6 (p=0.9)
3 year: FB 90.8 ± 5.5 / MB 90.9 ± 4.9 (p=0.9)
OKS
Pre: FB 21.8 ± 3.7 / MB 21.2 ± 3.7 (p=0,05)
3 year: FB 43.8 ± 1.7 / MB 43.8 ± 1.7
Pain:
No difference between FB and MB in VAS.
VAS
Pre: FB 7.4 ± 1.2 / MB 7.4 ± 1.5 (p=0.9)
3 year: FB 1.4 ± 0.9 / MB 1.5 ± 0.9 (p=0.8)
Postoperative complications and revisions:
At last follow-up (3 years), FB group reported three failures caused by aseptic loosening. Four failures were observed in the MB cohort: two for bearing dislocation and two for aseptic loosening. The Kaplan–Meier Curve found no differences in implant survivorship.
Comparative conclusions on quality of life:
According to the main findings of the present clinical trial, MB implants performed similar to FB in PKA in octogenarians. The FB group demonstrated shorted surgical time. No difference was found in patient reported outcome measures, ROM, implant positioning, and survivorship.
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BEST PROSTHESIS FOR UNICOMPARTMENTAL KNEE ARTHROSIS: FIXED OR MOBILE?
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