CAM 701144

Patient-Specific Instrumentation (eg, Cutting Guides) for Joint Arthroplasty

Category:Surgery   Last Reviewed:June 2018
Department(s):Medical Affairs   Next Review:June 2019
Original Date:June 2015    

Description
Custom knee implants and patient-specific instrumentation (PSI) have been developed as alternatives to off-the-shelf implants and conventional cutting guides for joint arthroplasty. Custom implants and patient-specific cutting guides are constructed with the aid of preoperative 3-dimensional computed tomography or magnetic resonance imaging scans and proprietary planning software. The goals of custom implants and patient-specific cutting guides are to increase surgical efficiency and to improve implant alignment and clinical outcomes.

The evidence on patient-specific cutting guides and custom knee implants in patients undergoing unicompartmental or total knee arthroplasty (TKA) includes a number of small randomized controlled trials (RCTs) and systematic reviews. Relevant outcomes include symptoms, functional outcomes, quality of life, resource utilization and treatment-related morbidity. The systematic reviews found no significant improvement in implant alignment, with some studies reporting worse alignment with PSI. To date, no functional benefits have been demonstrated. Larger RCTs examining the various PSI systems are in progress, and these systems differ in both planning and manufacturing; therefore, future assessment of PSI should address the specific system used. The evidence is insufficient to determine the effects of the technology on health outcomes.

Background 
Total knee arthroplasty (TKA; also called knee replacement) and unicompartmental knee arthroplasty (UKA) are established treatments for relief from significant, disabling pain caused by advanced arthritis. TKA is considered among the most successful medical procedures in the United States in terms of the degree of improvement in functional status and quality of life. As a result of the success of TKA, the increase in the aging population and the desire of older adults to remain physically active, the incidence of TKA is increasing rapidly. It is projected that by 2030, the demand for knee replacement will approach 3.5 million procedures annually.1 

TKA and UKA are performed by removing the damaged cartilage surface and a portion of underlying bone using a saw guided by templates and jigs. The removed cartilage and bone from the distal femur and proximal tibia are replaced with implants that recreate the surface of the joint. Patellar resurfacing may also be performed. Three-dimensional implant alignment (coronal, sagittal, axial) is considered to be critical for joint articulation and implant longevity. Generally, less than 3° deviation from the rotational or mechanical axis, as determined by a straight line through the center of the hip, knee and ankle on the coronal plane, is believed to minimize the risk of implant wear, loosening, instability and pain.

The placement of conventional cutting guides (templates and jigs) is based on anatomic landmarks or computer navigation (see evidence review 7.01.96). Use of conventional instrumentation has been shown to result in malalignment of approximately one-third of implants in the coronal plane.2 Computer-assisted navigation can significantly reduce the proportion of malaligned implants compared with conventional instrumentation, but has a number of limitations, including a lack of rotational alignment, increased surgical time and a long learning curve. In addition, no studies have demonstrated an improvement in clinical outcomes with computer-assisted navigation compared with conventional instrumentation. 

Custom implants and patient-specific instrumentation (PSI) have been developed as alternatives to off-the-shelf implants and conventional cutting guides, with the goal of improving both alignment and surgical efficiency. A number of patient-specific cutting guides and custom implants (with their associated cutting guides) are currently being marketed (see Regulatory Status section). Custom implants and patient-specific guides are constructed with the use of preoperative 3-dimensional computed tomography (CT) or magnetic resonance imaging (MRI) scans, which are taken about 4 to 6 weeks before the surgery. The images are sent to the planner/manufacturer to create a 3-dimensional model of the knee and proposed implant. After the surgeon reviews the model of the bone and implants, makes adjustments and approves the surgical plan, the manufacturer fabricates the custom knee implants and/or disposable cutting guides. 

The proposed benefits of using patient-specific implants and instrumentation during TKA include improved alignment, decreased operative time, increased patient throughput, fewer instrument trays, reduced risk of fat embolism and intraoperative bleeding (no intramedullary canal reaming), shorter recovery, reduced postoperative pain, reduced revision rate and reduced costs. However, the nonsurgical costs of the procedure may be increased due to the requirement for preoperative CT or MRI, preoperative review of the template and fabrication of the PSI. In addition, the patient-specific template relies on the same anatomic landmarks as conventional TKA and does not take soft tissue balancing into account. Thus, evaluation of this technology should also address the reliability of the cutting guides and the need for intraoperative changes such as conversion to conventional instrumentation.

Regulatory Status 
A number of patient-specific cutting block systems have been cleared for marketing by the U.S. Food and Drug Administration (FDA). An example is the single-use, disposable cutting guides designed and manufactured from patient imaging data (magnetic resonance imaging, computed tomography). The cutting guides are used to aid the surgeon intraoperatively in making the initial distal femoral and the initial proximal tibial bone cuts during TKA surgery. The cutting guides also establish the references for component orientations. Planning systems (eg, from Materialise NV) for the personalized instruments have also cleared for marketing by FDA through the 510(k) process.

In 2008, the Smith & Nephew Patient Matched Instrumentation (now called Visionaire™ Patient Matched Instrumentation) was the first patient-specific cutting guide to receive FDA clearance for marketing. Other patient-specific cutting guide systems cleared for marketing include:

  • MyKnee® Patient Matched Cutting Blocks (Medacta)
  • Prophecy™Pre-operative Navigation Alignment Guides (Wright Medical Technology)
  • Signature™Planner/Signature Guides (Materialise NV and Biomet)
  • Visionaire Patient Matched Cutting Blocks (Smith & Nephew)
  • TruMatch® Personalized Solutions (DePuy Orthopaedics)
  • X-PSI Knee System (ORTHOsoft)
  • Zimmer® Patient Specific Instruments and Zimmer® Patient Specific Instruments Planner (Materialise NV and Zimmer).

FDA product code: OOG.

Related Policies
70196 Computer-Assisted Musculoskeletal Surgical Naviational Orthopedic Procedure 

Policy
Use of patient-specific instrumentation (eg, cutting guides) for joint arthroplasty, including but not limited to use in unicompartmental or total knee arthroplasty, is INVESTIGATIONAL.

Policy Guidelines  
There are no specific codes for these implants and instrumentation. The joint arthroplasty procedure would be reported using the regular CPT codes for that surgery.

The preplanning for the surgery may involve magnetic resonance (MRI) or CT imaging, which may help to identify these procedures.

Benefit Application
BlueCard/National Account Issues  
State or federal mandates (e.g., FEP) may dictate that all U.S. Food and Drug Administration (FDA)-approved devices, drugs or biologics may not be considered investigational, and, thus, these devices may be assessed only on the basis of their medical necessity.

Rationale  
Assessment of efficacy for new technology involves a determination of whether the technology improves health outcomes. The optimal study design for a therapeutic intervention is a randomized controlled trial (RCT) that includes clinically relevant measures of health outcomes. Intermediate outcome measures, also known as surrogate outcome measures, may also be adequate if there is an established link between the intermediate outcome and true health outcomes. Nonrandomized comparative studies and uncontrolled studies can sometimes provide useful information on health outcomes, but are prone to biases such as noncomparability of treatment groups, the placebo effect and variable natural history of the condition.

A number of RCTs compare patient-specific instrumentation (PSI) versus conventional instrumentation for total knee arthroplasty (TKA). Therefore, this evidence review will focus on systematic reviews and RCTs that address clinical outcomes. The surrogate outcome measure of a reduction in malalignment may be informative to support improvement with the new technology. However, a reduction in the percentage of malaligned implants has not been definitively shown to result in improved clinical outcomes and is, therefore, not sufficient to demonstrate an improvement in clinical outcomes. In addition, because this is a relatively new technology, no long-term studies are currently available that could provide data on revision rates.

Patient-Specific Instrumentation
Systematic Reviews
Systematic reviews published to date have not found an improvement in accuracy or clinically significant decrease in operative time with PSI.

Thienpont et al. included 8 RCTs and 8 cohort studies (total N=1,755 patients) in their 2014 meta-analysis.3 The PSI systems used in the RCTs were Signature(Biomet),4-7 Zimmer Patient Specific Instruments® (Zimmer),8,9,7 TruMatch® (DePuy)10,11,7 and Visionaire (Smith & Nephew).7 This systematic review found no significant difference in the likelihood of mechanical axis malalignment with PSI versus conventional TKA across all studies, or when divided by RCTs (RR [risk ratio], 1.14, p=0.445) and cohort studies (RR=0.70, p=0.289). Alignment of the tibial component was significantly worse in the coronal and sagittal planes when using PSI. For the femoral component, alignment was significantly better in the coronal plane but not in the sagittal plane with PSI. Axial alignment of the tibial and femoral components did not differ significantly between PSI and conventional instrumentation. Funnel plots showed no strong evidence of publication bias.

A 2014 meta-analysis by Fu et al. included 10 RCTs (total N=837 knees) comparing PSI with conventional instrumentation.12 There were no significant differences between the 2 groups for outliers from a neutral mechanical axis or femoral component placement. Malalignment of the tibial component was higher with PSI in both the coronal plane (RR=2.50, p=0.02) and the sagittal plane (RR=1.47, p=0.02). Surgical time was shorter by a modest 3.54 minutes (weighted mean difference) with PSI. A funnel plot showed minimal evidence of publication bias. The 9 comparative studies (2 RCTs) in a 2014 meta-analysis by Voleti et al. used 4 different PSI systems and included 957 knee arthroplasties.13 There was no significant difference between the treatment groups in the percentage of outliers greater than 3 degrees from target alignment (p=0.7), while standard instrumentation had greater accuracy in the mechanical axis (p=0.02). Sagittal alignment, operative time, intraoperative blood loss and cost were similar between groups (p>0.1). 

Randomized Controlled Trials
Additional RCTs, published after the search dates of the systematic reviews, have compared PSI and conventional instrumentation. One RCT of 112 patients found no significant improvement in alignment with use of the Signature Personalized Patient Care System.14 Another RCT with 50 patients found no significant improvement in Knee Society Scores (KSS) at a minimum 6-month follow-up and an increase in the percentage of outliers with TruMatch® PSI (47% vs. 6%, p<0.000).15 It was also reported that PSI was abandoned during surgery in 7 of 22 knees (31.8%) because of possible malalignment. In 55%, the surgeon adjusted the joint space by increasing the bone (vs. 23% of control knees), and a different size of implant than planned was needed in 41% of PSI procedures. A 2014 publication reported clinical outcomes from 40 patients randomized to Zimmer® PSI or conventional instrumentation; alignment data had previously been reported and was included in the systematic reviews.9,16 Similar scores were obtained for the 2 groups for gait parameters and patient-reported outcomes (KSS, Knee Injury and Osteoarthritis Outcome Score, and 12-Item Short-Form Health Survey) at 3-month follow-up. In 2015, an RCT of 60 patients found no benefit in alignment, gait, function or quality of life after PSI for unicompartmental knee arthroplasty.17 

Ongoing and Unpublished Clinical Trials
Some currently unpublished trials that might influence this policy are listed in Table 1.

NCT No. Trial Name Planned Enrollment Completion Date
Ongoing

NCT02186587

CT-navigated, Patient-specific Custom Total Knee Replacement Versus Standard Total Knee Replacement: Comparison With a Marker-less Gait Analysis System and Validated Outcome Scores

115 Dec 2015

NCT01696552

Patient-specific Positioning Guides (PSPG) Technique Versus Conventional Technique in Total Knee Arthroplasty - a Prospective Randomized Study

200 May 2020

NCT01117571a

A Prospective, Multi-Center Study to Evaluate the ConforMIS iUni® G2 Unicompartmental Knee Resurfacing Device

120 Dec 2020

NCT02096393

A Prospective, Randomised Control Trial Assessing Clinical and Radiological Outcomes of Patient Specific Instrumentation In Total Knee Arthroplasty

100 Dec 2024

NCT 02494544a

A Prospective, Randomized, Multicenter Study to Evaluate the ConforMIS iTotal® (CR) Knee Replacement System Versus Off-the-Shelf Replacement

800 Aug 2025
Unpublished

NCT01876654

  64 Jun 2014

NCT02128464

Comparison of Customized Cutting Block (Visionaire) and Conventional Total Knee Arthroplasty: A Prospective Randomized Control Trial

100 Dec 2014

NCT02002624

RCT Multicenter Comparison of Patient-Specific Versus Conventional Instrumentation in Primary TKA

140 Completed Jul 2013

NCT01483066a

A Prospective, Randomized, Post-market, Multi-center Study and Cost-effectiveness Analysis of ShapeMatch Technology A Prospective, Randomized, Post-market, Multi-center Study and Cost-effectiveness Analysis of ShapeMatch Technology

150 Suspended Dec 2014

NCT: national clinical trial.
a Denotes industry-sponsored or cosponsored trial.

Summary of Evidence
The evidence on patient-specific cutting guides and custom knee implants in patients undergoing unicompartmental or total knee arthroplasty (TKA) includes a number of small randomized controlled trials (RCTs) and systematic reviews. Relevant outcomes include symptoms, functional outcomes, quality of life, resource utilization and treatment-related morbidity. The systematic reviews found no significant improvement in implant alignment, with some studies reporting worse alignment with PSI. To date, no functional benefits have been demonstrated. Larger RCTs examining the various PSI systems are in progress, and these systems differ in both planning and manufacturing; therefore, future assessment of PSI should address the specific system used. The evidence is insufficient to determine the effects of the technology on health outcomes.

Practice Guidelines and Position Statements
No guidelines or position statements that mention custom cutting guides or blocks for TKA were identified.

U.S. Preventive Services Task Force Recommendations
Not applicable.

References 

  1. Kurtz S, Ong K, Lau E, et al. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. Apr 2007;89(4):780-785. PMID 17403800
  2. Blue Cross and Blue Shield Association Technology Evaluation Center. Computer-assisted navigation for total knee arthroplasty. Technology Assessment Feb 2007;Volume 22, Tab 10. PMID 18411501
  3. Thienpont E, Schwab PE, Fennema P. A systematic review and meta-analysis of patient-specific instrumentation for improving alignment of the components in total knee replacement. Bone Joint J. Aug 2014;96-B(8):1052-1061. PMID 25086121
  4. Boonen B, Schotanus MG, Kerens B, et al. Intra-operative results and radiological outcome of conventional and patient-specific surgery in total knee arthroplasty: a multicentre, randomised controlled trial. Knee Surg Sports Traumatol Arthrosc. Oct 2013;21(10):2206-2212. PMID 23928929
  5. Roh YW, Kim TW, Lee S, et al. Is TKA using patient-specific instruments comparable to conventional TKA? A randomized controlled study of one system. Clin Orthop Relat Res. Dec 2013;471(12):3988-3995. PMID 23907610
  6. Silva A, Sampaio R, Pinto E. Patient-specific instrumentation improves tibial component rotation in TKA. Knee Surg Sports Traumatol Arthrosc. Mar 2014;22(3):636-642. PMID 23989707
  7. Victor J, Dujardin J, Vandenneucker H, et al. Patient-specific guides do not improve accuracy in total knee arthroplasty: a prospective randomized controlled trial. Clin Orthop Relat Res. Jan 2014;472(1):263-271. PMID 23616267
  8. Chareancholvanich K, Narkbunnam R, Pornrattanamaneewong C. A prospective randomised controlled study of patient-specific cutting guides compared with conventional instrumentation in total knee replacement. Bone Joint J. Mar 2013;95-B(3):354-359. PMID 23450020
  9. Parratte S, Blanc G, Boussemart T, et al. Rotation in total knee arthroplasty: no difference between patientspecific and conventional instrumentation. Knee Surg Sports Traumatol Arthrosc. Oct 2013;21(10):2213-2219. PMID 23942938
  10. Chotanaphuti T, Wangwittayakul V, Khuangsirikul S, et al. The accuracy of component alignment in custom cutting blocks compared with conventional total knee arthroplasty instrumentation: prospective control trial. Knee. Jan 2014;21(1):185-188. PMID 23999209
  11. Hamilton WG, Parks NL, Saxena A. Patient-specific instrumentation does not shorten surgical time: a prospective, randomized trial. J Arthroplasty. Sep 2013;28(8 Suppl):96-100. PMID 23910821
  12. Fu H, Wang J, Zhou S, et al. No difference in mechanical alignment and femoral component placement between patient-specific instrumentation and conventional instrumentation in TKA. Knee Surg Sports Traumatol Arthrosc. Jun 11 2014. PMID 25026931
  13. Voleti PB, Hamula MJ, Baldwin KD, et al. Current data do not support routine use of patient-specific instrumentation in total knee arthroplasty. J Arthroplasty. May 27 2014;29(9):1709-1712. PMID 24961893
  14. Kotela A, Kotela I. Patient-specific computed tomography based instrumentation in total knee arthroplasty: a prospective randomized controlled study. Int Orthop. Jun 28 2014;38(10):2099-2107. PMID 24968788
  15. Woolson ST, Harris AH, Wagner DW, et al. Component alignment during total knee arthroplasty with use of standard or custom instrumentation: a randomized clinical trial using computed tomography for postoperative alignment measurement. J Bone Joint Surg Am. Mar 5 2014;96(5):366-372. PMID 24599197
  16. Abdel MP, Parratte S, Blanc G, et al. No benefit of patient-specific instrumentation in TKA on functional and gait outcomes: a randomized clinical trial. Clin Orthop Relat Res. Mar 7 2014;472(8):2468-2476. PMID 24604110
  17. Ollivier M, Parratte S, Lunebourg A, et al. The John Insall Award: No Functional Benefit After Unicompartmental Knee Arthroplasty Performed With Patient-specific Instrumentation: A Randomized Trial. Clin Orthop Relat Res. Mar 20 2015. PMID 25791446 

Coding Section

Codes Number Description
CPT   No specific code – see Policy Guidelines
ICD-9 Procedure    
ICD-9 Diagnosis   Investigational for all diagnoses
HCPCS    
ICD-10-CM (efffective 10/01/15)   Investigational for all diagnoses
  M17.0-M17.9

Osteoarthritis of the knee code range

ICD-10-PCS (effective 10/01/15)   ICD-10-PCS codes are only used for inpatient services. There is no specific ICD-10-PCS code for this procedure.
Type of Service    
Place of Service    

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross and Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

"Current Procedural Terminology© American Medical Association.  All Rights Reserved" 

History From 2015 Forward     

06/07/2018 

Annual review, removing " custom implants" from policy statement, updating title, regulatory status and references. 

06/12/2017 

Annual review, no change to policy intent. 

06/07/2016 

Annual review, no change to policy intent. Updating background, description, regulatory status, rationale and references.

06/18/2015

NEW POLICY


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