Comparative Study of Total Knee Arthroplasty Using a Customized-patient Specific Instrument System.

Patient-specific instrumentation (PSI) has been introduced in total knee arthroplasty (TKA) as a new technology for improving accuracy in restoration of the alignment and biomechanics of the lower limb. PSI in TKA refers to custom-made cutting jigs manufactured according to the patient's anatomic configuration of distal femur and proximal tibia based on preoperative magnetic resonance imaging (MRI) or computed tomography (CT) scans. MRI- and CT-based PSI systems are available from various manufacturers for preoperative planning. MRI offers precise visualization of articular cartilage without the risk of radiation exposure, but it is expensive and requires long scan times. In contrast, CT enables accurate identification of the contour of the femur and tibia at short scan times, but it does not provide information on the cartilage thickness and carries the risk of radiation exposure. As a result, there is a possibility of some discrepancy between the thickness of bone resection proposed by MRI- or CT-based PSI system and the actual thickness of bone cut. Although PSI has been the focus of study in many recent researches, there has been no clinical study comparing MRI-based and CT-based PSI systems in preoperative planning. Therefore the investigators questioned whether the MRI-based PSI that reflects the cartilage layer would provide more precision in TKA than the CT-based PSI. The purpose of this study was to investigate the accuracy of MRI-based PSI and CT-based PSI in predicting bone resection thickness in TKA.

Study Overview

• Status: Unknown
• Conditions: Osteoarthritis, Knee; Arthroplasty, Replacement, Knee
• Intervention / Treatment: Device: Patient specific instrumentation (MRI); Device: Patient specific instrumentation (CT)

• Study Type: Interventional
• Enrollment (Actual): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 134-090
    • Kyung Hee University Hospital at Gangdong

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Of the patients who had been scheduled for TKA for the treatment of primary osteoarthritis only with varus deformity, those who had been waiting 6 weeks for TKA using an MRI-based or CT-based PSI system and had consented to the relatively new technique were enrolled in the study.

Exclusion Criteria:

• Patients with primary osteoarthritis with valgus deformity, rheumatoid arthritis, hemophilic arthritis, posttraumatic arthritis, other inflammatory arthritis, or a history of previous high tibial osteotomy were excluded from the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: patient specific instrumentation (MRI); MRI based patient-specific instrumentation	Device: Patient specific instrumentation (MRI)
Active Comparator: patient specific instrumentation (CT); CT based patient-specific instrumentation	Device: Patient specific instrumentation (CT)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The absolute differences (mm) between the planned resection thickness and the actual resection thickness in the femur and the tibia.	After bone resection using a patient-specific cutting jig, the actual thickness of resected bone was measured in 0.1 mm increments by the Vernier caliper (B.Braun-Aesculap, Tuttlingen, Germany) and compared with the planned resection thickness preoperatively using the PSI program.In the MRI group, the intraoperative cutting thickness was compared directly with the preoperatively planned thickness, whereas the presumed thickness of cartilage (2 mm) was added to actual thickness of resected bone from the lateral condyles in the CT group. Finally, the thickness of saw blade (1.27-mm) was added to every resected bone in all cases.	intraoperative time

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
radiographic assessment	The mechanical axis (MA) of the lower extremity and the coronal and sagittal alignments of the femoral and tibial components were measured on the anterior and lateral weight-bearing radiographs of the knee and the lower extremity orthogram before the surgery and 6 weeks after the surgery. The measurements were performed using a picture-acquiring communication system (PACS, Infinitt Healthcare, Seoul, Korea), and the data were recorded to one decimal place.	postoperative 6 weeks

Collaborators and Investigators

• Sponsor: Kyung Hee University Hospital at Gangdong
• Investigators: Principal Investigator: Kang-Il Kim, MD,PhD, Kyung Hee University Hospital at Gangdong

Study record dates

Study Major Dates

• Study Start: February 1, 2011
• Primary Completion (Actual): September 1, 2012

Study Registration Dates

• First Submitted: July 13, 2015
• First Submitted That Met QC Criteria: July 14, 2015
• First Posted (Estimate): July 16, 2015

Study Record Updates

• Last Update Posted (Estimate): July 16, 2015
• Last Update Submitted That Met QC Criteria: July 14, 2015
• Last Verified: July 1, 2015

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: KHNMC 2011-058