An interventional study of Persona total knee system and Nexgen total knee system in Osteoarthritis, Knee, sponsored by Zimmer Biomet. Active, not recruiting at 5 sites in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-12.
Sponsored by Zimmer Biomet · Not applicable, Interventional, and Treatment
A multicenter, prospective randomized controlled trial comparing the Persona knee system to the Nexgen knee system in total knee arthroplasty.
Knee replacement is an established treatment for late stage osteoarthritis (OA) of the knee. There is an increasing demand for joint replacement in a younger population. Due to the changing demographics of joint replacement, the population of younger patients are seeking options that not only correct their disease or deformity, but do not limit them in activity. Studies have shown that modern implant designs can potentially improve outcome. Therefore new implants are introduced to the marked with the theoretical benefit of improved implant survival and superior patient reported outcomes. Within Total knee arthroplasty, design changes are introduced in an attempt to improve knee kinematics, functionality and outcome, but those potential improvements need to be evaluated.
The NexGen Total Knee System is a knee replacement system with well a documented performance and has been the device of choice in many institutions. Recently, Zimmer-Biomet have introduced Persona Total Knee system with design changes that include asymmetric tibia plate, increased medial pivoting and more extensive choices in respect to poly thickness, all with the purpose to improve balancing, stability and longevity. Such design changes and proposed benefits need to be evaluated in a prospective clinical trial, with focus on patient safety, satisfaction and implant durability.
The aim is to evaluate intra-operative and postop complications, long-term survivorship and patient reported outcome measures following primary total knee replacement using Persona Cruciate Retaining (CR) total Knee system compared to NexGen Cruciate Retaining (CR) total Knee System.
This project is carried out as a 2-arm randomized controlled single-blinded trial. A total of 314 participants are to be included at 6 centers in Denmark. Participants are seen on an outpatient basis at 3 months and 1 and 2 years postoperatively. After 2-year follow-up the patients will be followed for survivorship through the Danish Knee Arthroplasty Registry.
3,302 studies on the registry are indexed under Osteoarthritis, Knee; 608 are open to participants now.
This study's enrollment of 332 is above the median of 70 across 2,731 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Zimmer Biomet is the lead sponsor of 271 studies on the registry; 28 are open to participants now.
Of its 23 completed or terminated interventional studies of FDA-regulated products, 19 (83%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Patients who received a Persona CR total knee implant
Device: Persona total knee system
Patients who received a NexGen CR total knee implant
Device: Nexgen total knee system
314 participants with knee osteoarthritis set to receive primary total knee arthroplasty will receive either Persona knee or the Nexgen
Also known as: Zimmer Biomet Persona total knee system
314 participants with knee osteoarthritis set to receive primary total knee arthroplasty will receive either Persona knee or the Nexgen
Also known as: Zimmer Biomet Nexgen total knee system
Oxford Knee Score
The OKS is a patient-reported outcome questionnaire that was developed to specifically assess the patient's perspective of outcome following TKA. The OKS consists of twelve questions covering function and pain associated with the knee. To calculate the total score, each question is scored from 0 (worst outcome) to 4 (best outcome) and the sum of all 12 items is reported with a maximum of 48, representing the best score possible. The outcome score can be categorized as Excellent: \> 41; Good: 34 - 41; Fair: 27 - 33; Poor: \< 27
Time frame: 3 months, 1 year and 2 years postoperatively
Oxford Knee Score - Activity & Participation Questionnaire (APQ)
The OKS-APQ is an 8 item questionnaire with each question scored from 0 (worst outcome) to 4 (best outcome). The resulting score is then summed and converted to a score ranging from 0 (worst possible score) to a maximum of 100 (best possible score).
Time frame: 3 months, 1 year and 2 years postoperatively
Forgotten Joint Score (FJS)
The FJS-12 is a patient-reported outcome questionnaire that was developed to specifically assess the patient's level of awareness of the joint during daily activities. The FJS consists of twelve questions covering function and pain associated with the knee. For each question, there is a choice of five answers between never (0), almost never (1), seldom (2), sometimes (3) and mostly (4). All scores are summed up and divided by the number of completed items. This value is then multiplied by 25 and thereafter subtracted from 100. An outcome score of 100 (highest possible score) indicates the lowest level of joint awareness, while a total score of 0 indicates the highest level of joint awareness.
Time frame: 3 months, 1 year and 2 years postoperatively
Patient Satisfaction and Anchoring Questions - Question 1
Patients were asked to answer the following satisfaction/anchoring question: "How are your knee problems now, compared to prior to your operation?"
Time frame: 3 months, 1 year and 2 years postoperatively
Patient Satisfaction and Anchoring Questions - Question 2
Patients were asked to answer the following satisfaction/anchoring question: "Taking into account all the activities you have during your daily life, your level of pain and functional impairment, do you consider that your current state is satisfactory?"
Time frame: 3 months, 1 year and 2 years postoperatively
Patient Satisfaction and Anchoring Questions - Question 3
Patients were asked to answer the following satisfaction/anchoring question: "If you answered No, i.e. not satisfied to the result would you consider your current state as being so unsatisfactory that you think the treatment has failed?"
Time frame: 3 months, 1 year and 2 years postoperatively
Patient Satisfaction and Anchoring Questions - Question 4
Patients were asked to answer the following satisfaction/anchoring question: "Would you have your knee operated again?"
Time frame: 3 months, 1 year and 2 years postoperatively
EuroQol 5D (EQ-5D) Score
The EQ-5D is a standardized instrument widely used to measure health status. It is a self-reported assessment about the patient's quality of life composed of two parts: a questionnaire and a visual analogue scale (VAS). The questionnaire includes 5 questions referring to mobility, self-care, daily/usual activities, pain/discomfort and anxiety/depression. For EQ-5D-3L, each question can be answered in three ways, indicating no, moderate, or extreme pain. In the derived EQ-5D-3L score, the highest score is 1 and the lowest score is -0.59; negative numbers correspond to a self-assessed health state worse than being dead.
Time frame: 3 months, 1 year and 2 years postoperatively
Radiolucency / Osteolysis
All X-rays were sent to an independent radiographer. Postoperative lucency was determined as presence of radiolucent intervals at the cement-bone interface. Femoral lucency and tibial lucency are reported separately.
Time frame: Immediate postoperative and 3 months, 1 year and 2 years postoperatively
Long-term Survivorship
Registry data at 5, 7 and 10 years postoperatively.
Time frame: 5, 7 and 10 years postoperatively.
| Milestone | Persona CR | NexGen CR |
|---|---|---|
| Started | 157 | 157 |
| Completed | 146 | 145 |
| Not completed | 11 | 12 |
| Withdrew: Received non-study device intraoperatively | 0 | 2 |
| Withdrew: Death | 1 | 0 |
| Withdrew: Withdrawal by subject | 1 | 3 |
| Withdrew: Lost to follow-up | 5 | 4 |
| Withdrew: Adverse event | 4 | 2 |
| Withdrew: Met an exclusion criterion | 0 | 1 |
The OKS is a patient-reported outcome questionnaire that was developed to specifically assess the patient's perspective of outcome following TKA. The OKS consists of twelve questions covering function and pain associated with the knee. To calculate the total score, each question is scored from 0 (worst outcome) to 4 (best outcome) and the sum of all 12 items is reported with a maximum of 48, representing the best score possible. The outcome score can be categorized as Excellent: \> 41; Good: 34 - 41; Fair: 27 - 33; Poor: \< 27
| score on a scale | Persona CR | NexGen CR |
|---|---|---|
| Preoperative | 22.1 ± 6.7 | 22.2 ± 6.5 |
| 3 months | 33.5 ± 7.8 | 32.9 ± 7.9 |
| 1 year | 39.5 ± 7.7 | 38.6 ± 7.6 |
| 2 years | 40.7 ± 7.3 | 40.8 ± 6.6 |
The OKS-APQ is an 8 item questionnaire with each question scored from 0 (worst outcome) to 4 (best outcome). The resulting score is then summed and converted to a score ranging from 0 (worst possible score) to a maximum of 100 (best possible score).
| score on a scale | Persona CR | NexGen CR |
|---|---|---|
| Preoperative | 16.4 ± 19.7 | 15.2 ± 19.4 |
| 3 months | 50.0 ± 30.8 | 49.3 ± 30.5 |
| 1 year | 71.4 ± 30.4 | 64.3 ± 31.9 |
| 2 years | 70.5 ± 31.2 | 69.4 ± 31.0 |
The FJS-12 is a patient-reported outcome questionnaire that was developed to specifically assess the patient's level of awareness of the joint during daily activities. The FJS consists of twelve questions covering function and pain associated with the knee. For each question, there is a choice of five answers between never (0), almost never (1), seldom (2), sometimes (3) and mostly (4). All scores are summed up and divided by the number of completed items. This value is then multiplied by 25 and thereafter subtracted from 100. An outcome score of 100 (highest possible score) indicates the lowest level of joint awareness, while a total score of 0 indicates the highest level of joint awareness.
| score on a scale | Persona CR | NexGen CR |
|---|---|---|
| Preoperative | 14.3 ± 13.7 | 14.1 ± 13.4 |
| 3 months | 42.8 ± 27.8 | 42.6 ± 26.0 |
| 1 year | 60.3 ± 27.8 | 56.2 ± 29.2 |
| 2 years | 65.0 ± 29.0 | 64.3 ± 27.0 |
Patients were asked to answer the following satisfaction/anchoring question: "How are your knee problems now, compared to prior to your operation?"
| Participants | Persona CR | NexGen CR |
|---|---|---|
| 3 months — Better, an important improvement | 109 | 99 |
| 3 months — Somewhat better, but enough to be an important improvement | 31 | 33 |
| 3 months — Very small change, not enough to be an important improvement | 6 | 7 |
| 3 months — About the same | 3 | 4 |
| 3 months — Very small change, not enough to be an important worsening | 2 | 4 |
| 3 months — Somewhat worse, but enough to be an important worsening | 2 | 3 |
| 3 months — Worse, an important worsening | 0 | 0 |
| 3 months — Better, an important improvement + About the same | 1 | 0 |
| 3 months — Very small change,not enough to be an important worsening + Somewhat worse | 0 | 1 |
| 1 year — Better, an important improvement | 123 | 111 |
| 1 year — Somewhat better, but enough to be an important improvement | 16 | 29 |
| 1 year — Very small change, not enough to be an important improvement | 6 | 2 |
| 1 year — About the same | 0 | 1 |
| 1 year — Very small change, not enough to be an important worsening | 2 | 0 |
| 1 year — Somewhat worse, but enough to be an important worsening | 1 | 5 |
| 1 year — Worse, an important worsening | 1 | 3 |
| 1 year — Better, an important improvement + About the same | 0 | 0 |
| 1 year — Very small change,not enough to be an important worsening + Somewhat worse | 0 | 0 |
| 2 years — Better, an important improvement | 118 | 123 |
| 2 years — Somewhat better, but enough to be an important improvement | 18 | 19 |
| 2 years — Very small change, not enough to be an important improvement | 3 | 2 |
| 2 years — About the same | 1 | 0 |
| 2 years — Very small change, not enough to be an important worsening | 1 | 1 |
| 2 years — Somewhat worse, but enough to be an important worsening | 1 | 1 |
| 2 years — Worse, an important worsening | 0 | 1 |
| 2 years — Better, an important improvement + About the same | 0 | 0 |
| 2 years — Very small change,not enough to be an important worsening + Somewhat worse | 0 | 0 |
Patients were asked to answer the following satisfaction/anchoring question: "Taking into account all the activities you have during your daily life, your level of pain and functional impairment, do you consider that your current state is satisfactory?"
| Participants | Persona CR | NexGen CR |
|---|---|---|
| 3 months — Yes | 122 | 119 |
| 3 months — No | 32 | 32 |
| 1 year — Yes | 127 | 132 |
| 1 year — No | 22 | 19 |
| 2 years — Yes | 130 | 137 |
| 2 years — No | 12 | 10 |
Patients were asked to answer the following satisfaction/anchoring question: "If you answered No, i.e. not satisfied to the result would you consider your current state as being so unsatisfactory that you think the treatment has failed?"
| Participants | Persona CR | NexGen CR |
|---|---|---|
| 3 months — Yes | 5 | 1 |
| 3 months — No | 27 | 29 |
| 3 months — No answer provided | 0 | 2 |
| 1 year — Yes | 4 | 8 |
| 1 year — No | 18 | 11 |
| 1 year — No answer provided | 0 | 0 |
| 2 years — Yes | 4 | 4 |
| 2 years — No | 8 | 5 |
| 2 years — No answer provided | 0 | 1 |
Patients were asked to answer the following satisfaction/anchoring question: "Would you have your knee operated again?"
| Participants | Persona CR | NexGen CR |
|---|---|---|
| 3 months — Yes, definitely | 112 | 116 |
| 3 months — Maybe, don't know | 32 | 27 |
| 3 months — No | 10 | 8 |
| 1 year — Yes, definitely | 121 | 119 |
| 1 year — Maybe, don't know | 25 | 25 |
| 1 year — No | 3 | 7 |
| 2 years — Yes, definitely | 114 | 114 |
| 2 years — Maybe, don't know | 22 | 23 |
| 2 years — No | 6 | 10 |
The EQ-5D is a standardized instrument widely used to measure health status. It is a self-reported assessment about the patient's quality of life composed of two parts: a questionnaire and a visual analogue scale (VAS). The questionnaire includes 5 questions referring to mobility, self-care, daily/usual activities, pain/discomfort and anxiety/depression. For EQ-5D-3L, each question can be answered in three ways, indicating no, moderate, or extreme pain. In the derived EQ-5D-3L score, the highest score is 1 and the lowest score is -0.59; negative numbers correspond to a self-assessed health state worse than being dead.
| score on a scale | Persona CR | NexGen CR |
|---|---|---|
| Preoperative | 0.500 ± 0.272 | 0.516 ± 0.272 |
| 3 months | 0.765 ± 0.190 | 0.778 ± 0.173 |
| 1 year | 0.840 ± 0.201 | 0.840 ± 0.173 |
| 2 years | 0.868 ± 0.187 | 0.866 ± 0.197 |
All X-rays were sent to an independent radiographer. Postoperative lucency was determined as presence of radiolucent intervals at the cement-bone interface. Femoral lucency and tibial lucency are reported separately.
| Participants | Persona CR | NexGen CR |
|---|---|---|
| Immediate postoperative : Tibial lucency | 0 | 0 |
| Immediate postoperative : Femoral lucency | 1 | 2 |
| 3 months : Tibial lucency | 3 | 9 |
| 3 months : Femoral lucency | 7 | 9 |
| 1 year : Tibial lucency | 6 | 16 |
| 1 year : Femoral lucency | 14 | 22 |
| 2 years : Tibial lucency | 14 | 16 |
| 2 years : Femoral lucency | 21 | 20 |
Registry data at 5, 7 and 10 years postoperatively.
Results for this outcome have not been posted.
Collected over From study start up to 2 years post-operatively. Non-serious events are listed at a 1% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Persona CR | 1/156 (0.6%) | 23/156 (14.7%) | 16/156 (10.3%) |
| NexGen CR | 0/155 (0%) | 28/155 (18.1%) | 20/155 (12.9%) |
| Event | Persona CR | NexGen CR |
|---|---|---|
| Contralateral Knee ReplacementSurgical and medical procedures | 3/156 | 5/155 |
| ArythmiaCardiac disorders | 0/156 | 4/155 |
| Knee StiffnessMusculoskeletal and connective tissue disorders | 0/156 | 3/155 |
| CancerNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 2/156 | 3/155 |
| Infection (non-knee)Gastrointestinal disorders | 0/156 | 2/155 |
| Knee PainMusculoskeletal and connective tissue disorders | 0/156 | 2/155 |
| Shortness of Breath/DyspneaRespiratory, thoracic and mediastinal disorders | 0/156 | 2/155 |
| Respiratory InfectionRespiratory, thoracic and mediastinal disorders | 2/156 | 0/155 |
| Knee InstabilitySurgical and medical procedures | 2/156 | 0/155 |
| Myocardial InfarctionCardiac disorders | 0/156 | 1/155 |
| Event | Persona CR | NexGen CR |
|---|---|---|
| Knee PainMusculoskeletal and connective tissue disorders | 6/156 | 9/155 |
| Contralateral Knee ReplacementSurgical and medical procedures | 0/156 | 4/155 |
| Delayed Wound HealingSkin and subcutaneous tissue disorders | 1/156 | 2/155 |
| EffusionBlood and lymphatic system disorders | 1/156 | 2/155 |
| Knee SwellingMusculoskeletal and connective tissue disorders | 2/156 | 2/155 |
| Knee Pain Due to FallMusculoskeletal and connective tissue disorders | 2/156 | 0/155 |
| Knee StiffnessMusculoskeletal and connective tissue disorders | 2/156 | 1/155 |
| Cancer DiagnosisNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 1/156 | 1/155 |
| Flexion ContractureMusculoskeletal and connective tissue disorders | 1/156 | 1/155 |
157 patients were enrolled and randomized to each group, but 3 cases were excluded intraoperatively: 2 in the NexGen group and 1 in the Persona group.
| Age, Continuous(years) | Persona CR | NexGen CR | Total |
|---|---|---|---|
| Mean | 68.1 ± 8.2 | 67.7 ± 9.0 | 67.9 ± 8.6 |
| Sex: Female, Male(Participants) | Persona CR | NexGen CR | Total |
|---|---|---|---|
| Female | 99 | 90 | 189 |
| Male | 57 | 65 | 122 |
| Race and Ethnicity Not Collected(Participants) | Persona CR | NexGen CR | Total |
|---|---|---|---|
| Count of participants | — | — | 0 |
| Region of Enrollment(participants) | Persona CR | NexGen CR | Total |
|---|---|---|---|
| Denmark | 156 | 155 | 311 |
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