iAssist vs. Conventional Instrumentation in Total Knee Arthroplasty

Not Applicable

Completed

Conditions: Avascular Necrosis
Post-traumatic; Arthrosis
Knee Osteoarthritis

Interventions: Procedure: total knee arthroplasty

Registration Number: NCT03111407

Lead Sponsor: Zimmer, GmbH

Brief Summary: The purpose of this prospective study is to evaluate Zimmer® iASSIST™ with respect to radiographic, clinical and economic outcomes and compared to conventional instrumentation in primary total knee arthroplasty (NexGen or Persona knee implants).

Detailed Description: The study design is a prospective, multicenter, comparative outcome study. The study requires each site to obtain IRB (Institutional Review Board) approval prior to study enrollment. All potential study subjects will be required to participate in the Informed Consent Process.

All study subjects will undergo preoperative clinical evaluations prior to their total knee arthroplasty. Investigators will collect clinical data for 12 months. Follow-up clinical visits include 3 and 12 months post-operatively.

The primary endpoint of this study is defined as component alignment as determined using long leg X-Rays. The secondary endpoint will be to evaluate the Knee Society Score, EQ-5D (EuroQol-5Dimensions) scoring system, operating room time, blood loss and complications

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 72

Inclusion Criteria

Patient is male or female
Patient needs a primary total knee replacement using the NexGen LPS Flex or Persona knee implant
Patient is diagnosed with non-inflammatory degenerative joint disease (e.g., osteoarthritis, post-traumatic arthritis, avascular necrosis, etc.)
Patient is over 18 years old
Patient is able to:
- Understand what participation in the study entails and willing to consent (patient or his/her legal guardian) to participate in the study by signing and dating an IRB/EC (ethics committee) approved inform consent form, and
- Follow surgeon/staff instructions, and
- Return for all follow-up evaluations, and
- Able and willing to undergo a preoperative full-leg, standing radiographs and/or CT-scan
Patient meets an acceptable preoperative medical clearance and is free of or treated for cardiac, pulmonary, hematological or other conditions that would pose excessive operative risk.
Patient has a presence of varus or valgus deformity of 15 degrees or less.

Exclusion Criteria

Patient is currently enrolled in an investigational new drug or device study.
Patient has an active infection (including septic knee, distant infection, or osteomyelitis).
Patient has severe hip arthrosis.
Patient has neurological disorders (including, but not limited to Parkinson's disease).
Patient has had a prior ipsilateral unicompartmental knee arthroplasty, TKA, knee fusion or patellectomy.
Patient has hip or knee ankylosis.
Patient has inflammatory joint disease.
Patient has rheumatoid knee arthritis.
Patient has indications of intra- and/or extra-articular deformations that would eliminate or tend to eliminate adequate implant support or prevent the use of an appropriately sized implant, such as polio, history of tibial plateau fracture, etc.
Patient has any metal within 150 mm of the joint line for the operative-side knee.
Patient has knee deformities greater than 15 degrees of fixed varus, valgus, or flexion contracture on initial physical examination.
Female who is pregnant or lactating.
Patient currently involved in any personal injury litigation, medical-legal or worker's compensation claims.
Patient has arterial disease or stents that would exclude the use of a tourniquet.
Patient has insufficient quality or quantity of bone to support the implant due to prior knee surgery (or surgeries), cancer, metabolic bone disease, osteoporosis/osteopenia (diagnosed or treated with medication), active/old/remote infection, etc.
Patient has a mental condition that may interfere with his/her ability to give an informed consent or interfere with his/her ability or willingness to fulfill the requirements of the study.
Patient has a condition that would place excessive demands on the implant (e.g., Charcot's joints, muscle deficiencies, multiple joint disabilities, skeletal immaturity, etc.).
Patient has collateral ligament insufficiency.
Patient has an immunosuppressive disorder (e.g., AIDS, etc.) that would require cytotoxic drugs, corticosteroids, large dose of irradiation, or antilymphocytic serum.
Patient has an existing condition that would, in the opinion of the investigator, compromise participation or follow-up in this study.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
conventional instrumentation	total knee arthroplasty	patients will have primary total knee arthroplasty with the conventional instrumentation.
iAssist group	total knee arthroplasty	patients will have primary total knee arthroplasty with the iAssist. The iAssist Knee System is a computer assisted stereotaxic surgical instrument system to assist the surgeon in the positioning of orthopedic implant system components intra-operatively. It involves surgical instruments and position sensors to determine alignment axes in relation to anatomical landmarks and to precisely position alignment instruments and implant components relative to these axes.

Primary Outcome Measures

Name	Time	Method
Component Alignment	1 year	Assess the differences in component alignment, measured by the mean of radiographs, between iASSIST™ and conventional instrumentation in primary total knee arthroplasty (TKA) procedures.

Secondary Outcome Measures

Name	Time	Method
Knee Society Score Assessment	1 year	Assess the differences in Knee Society Score between iASSIST™ and conventional instrumentation in primary TKA procedures. Higher (and better) score value: 100, lower value: 0. Score 80-100 = Excellent Score 70-79 = Good Score 60-69 = Fair Score below 60 = Poor
Knee Society Score Function	1 year	Knee Society Score function asses 12 months postoperatively between iASSIST™ and conventional instrumentation in primary TKA procedures. Higher (and better) score value: 100, lower value: 0. Score 80-100 = Excellent Score 70-79 = Good Score 60-69 = Fair Score below 60 = Poor
EQ-5D Questionnaire	1 year	Assess the differences in EQ-5D between iASSIST™ and conventional instrumentation in primary TKA procedures at 12 months postoperatively. Comparison of the derived EQ-5D scale and health state between the 2 groups. The EQ-5D questionnaire includes five dimensions (5D): mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. EQ-5D values range from -0.2 to 1 where the negative values correspond to bad health states (states worse than death), and 1.0 corresponds to perfect health.

Trial Locations

Locations (3): Hospital Unviersitario Son Espases
🇪🇸
Palma de Mallorca, Spain
Hospital El Angel, S.A.
🇪🇸
Malaga, Spain
Universitätsklinik Balgrist
🇨🇭
Zurich, Switzerland