Subject:
Unicondylar Interpositional Spacer as a Treatment of Unicompartmental Arthritis of the Knee
Description:
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IMPORTANT NOTE:
The purpose of this policy is to provide general information applicable to the administration of health benefits that Horizon Blue Cross Blue Shield of New Jersey and Horizon Healthcare of New Jersey, Inc. (collectively “Horizon BCBSNJ”) insures or administers. If the member’s contract benefits differ from the medical policy, the contract prevails. Although a service, supply or procedure may be medically necessary, it may be subject to limitations and/or exclusions under a member’s benefit plan. If a service, supply or procedure is not covered and the member proceeds to obtain the service, supply or procedure, the member may be responsible for the cost. Decisions regarding treatment and treatment plans are the responsibility of the physician. This policy is not intended to direct the course of clinical care a physician provides to a member, and it does not replace a physician’s independent professional clinical judgment or duty to exercise special knowledge and skill in the treatment of Horizon BCBSNJ members. Horizon BCBSNJ is not responsible for, does not provide, and does not hold itself out as a provider of medical care. The physician remains responsible for the quality and type of health care services provided to a Horizon BCBSNJ member.
Horizon BCBSNJ medical policies do not constitute medical advice, authorization, certification, approval, explanation of benefits, offer of coverage, contract or guarantee of payment.
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Interpositional unicondylar spacers are metallic implants that are inserted into the joint space between the affected tibial plateau and femoral condyle. Instead of being fixed, the spacers are held in place by the geometry of the curved implant, ligament tension, and surrounding soft tissue structures. Metallic interpositional unicondylar spacers have been developed as possible alternatives to osteotomy or unicompartmental arthroplasty for treatment of unicompartmental knee arthritis.
While osteoarthritis of the knee typically involves both medial and lateral components, some patients may have signs or symptoms confined to only one compartment, often as a result of specific injury. Initial treatment of uni- and bicompartmental disease is similar, i.e., analgesics, viscosupplementation, and arthroscopic debridement. When patients fail to respond to these more conservative therapies, surgical interventions may be indicated.
Older patients with arthritis typically consider total knee replacement, but may be considered for unicondylar knee arthroplasty. The metal-to-plastic unicondylar prosthesis has both tibial and femoral components but leaves intact both cruciate ligaments, the patellofemoral joint, and the opposite compartment, thus preserving nearly normal knee kinematics. Unicompartmental arthroplasties are typically performed in patients with isolated medial arthritis who are older than 60 years, have a low level of physical activity, and weigh less than 180 lbs.
Younger patients are usually not considered ideal candidates for total knee arthroplasty since they would be expected to need at least one additional total knee replacement in their lifetimes. The preferred option for young patients with unicompartmental disease is high tibial osteotomy. Those with medial compartment disease may also be candidates for unicompartmental arthroplasty or for fixed metallic hemiarthroplasty. MacIntosh and McKeever hemiarthroplasty devices were used primarily between 1950 and 1970, but their use has decreased with the refinement of total knee arthroplasty procedures. These devices require bone cuts that might complicate future arthroplasty procedures.
Metallic interpositional unicondylar spacers have been developed as possible alternatives to osteotomy or unicompartmental arthroplasty. These devices do not require any bone resection or mechanical fixation for proper function. Following debridement and resection of the meniscus, the device is fit to the joint space above the affected tibial plateau and held in place by its geometry, ligament tension, and surrounding soft tissue structures. The uncemented implant adapts to the kinematics of the knee, with a smooth metallic curved surface against which the femur articulates. Preservation of bone is important for the use of interpositional spacers as a bridge procedure in active young adults or for overweight patients who would not be candidates for unicompartmental arthroplasty.
In 2001, a cobalt alloy device, referred to as a "unicondylar interpositional spacer" or "UniSpacer," received clearance for marketing through a U.S. Food and Drug Administration (FDA) 510(k) process as an interpositional arthroplasty device, listing the MacIntosh and McKeever prostheses as predicate devices. The FDA clearance for the UniSpacer device is for "moderate degeneration of the medial compartment of the knee (grade III-IV chondromalacia) with not more than minimal degeneration (grade I-II chondromalacia, no loss of joint space) in the lateral condyle and patellofemoral compartments." The Orthoglide Medical Knee Implant, which received 510(k) approval in 2006, is also indicated for “uncemented use in the treatment of moderate degeneration of the medial compartment of the knee,” but for grade II-IV chondromalacia.
Two other interpositional devices have received 510(k) approval, the Oti Unicondular Interpositional Spacer Osteoimplant (2002) and the Knee Interpositional Mini-Repair System (2003), listing the UniSpacer as a predicate device. The Knee Interpositional Mini-Repair System is a patient-specific design, with specifications taken from magnetic resonance scans. These devices are indicated for the uncemented treatment of medial and/or lateral tibial articulating surfaces of the osteoarthritic knee with grade II-IV chondromalacia.
Policy:
(NOTE: For Medicare Advantage, Medicaid and FIDE-SNP, please refer to the Coverage Sections below for coverage guidance.)
Unicondylar interpositional spacer is considered investigational as a treatment of unicompartmental arthritis of the knee.
Medicare Coverage:
There is no National Coverage Determination (NCD) or Local Coverage Determination (LCD) for jurisdiction JL for this service. Therefore, Medicare Advantage Products will follow the Horizon BCBSNJ Medical Policy.
Medicaid Coverage:
For members enrolled in Medicaid and NJ FamilyCare plans, Horizon BCBSNJ applies the above medical policy.
FIDE SNP:
For members enrolled in a Fully Integrated Dual Eligible Special Needs Plan (FIDE-SNP): (1) to the extent the service is covered under the Medicare portion of the member’s benefit package, the above Medicare Coverage statement applies; and (2) to the extent the service is not covered under the Medicare portion of the member’s benefit package, the above Medicaid Coverage statement applies.
[RATIONALE: Two retrospective reports were identified on the use of the UniSpacer. The largest group of patients reported was 71 UniSpacer implants in 67 patients (ages ranged from 38–83 years and weights ranged from 53–168 kg). (Hallock RH and Fell BM, 2003) At 1-year follow-up, 63 patients (66 knees) still had the implant; the 5 failed implants (7%) were converted to total knee arthroplasty for inadequate pain relief. Ten patients (14%) had their implants revised to another size because of persistent pain (n=6) or dislocation (n=4), and 17 patients (24%) required manipulation under anesthesia to correct postoperative arthrofibrosis. The rate of revision at 1 year was 21%, with an additional 24% requiring manipulation due to arthrofibrosis.
Another group reported their experience with 37 UniSpacer implants in 34 patients (ages ranging from 42–75 years) with baseline Knee Society functional and objective rating scales of 69 and 62 points, respectively. (Sisto DJ and Mitchell IL, 2005) At 2-year follow-up, functional and objective ratings had improved by about 10 points; there were no excellent results, 10 had good, 15 had fair, and 12 had poor results. Six of the 12 poor results were due to dislocation, and the 12 were revised to total knee arthroplasty. There was no significant change in average pain scores (preoperative: 22, postoperattive: 26), with complaints of pain during normal walking for 32 knees and activities limited by pain in 15 patients (41% of implants). Persistent postoperative swelling was present in 9 patients. No publications were identified on the use of other FDA-approved uncemented spacers.
A prospective study of 18 consecutive patients with isolated medial compartment osteoarthritis who provided informed consent for insertion of a Unispacer knee implant. Seventeen patients (94%) reported persistent symptoms between 3 and 6 months after surgery. (Bailie AG et al, 2008) At an average 17-month follow-up (range, 3 to 26 months), 12 (67%) patients had required further interventions, and 8 (44%) were classified as implant failures. The authors described these results as “disappointing.”
Based on the lack of controlled trials, combined with the high proportion of failures, revisions and adverse events in the identified retrospective and prospective reports, the use of interpositional unicondylar spacers is considered to be investigational.
Update
An updated search of the MEDLINE database identified 1 prospective study of 18 consecutive patients with isolated medial compartment osteoarthritis who provided informed consent for insertion of a Unispacer knee implant. Seventeen patients (94%) reported persistent symptoms between 3 and 6 months after surgery. (3) At an average 17-month follow-up (range, 3 to 26 months), 12 (67%) patients had required further interventions, and 8 (44%) were classified as implant failures. The authors described these results as “disappointing.” While current data indicate that the unicondylar interpositional spacer does not improve the net health outcome, this technology is in an early stage of research and development. The unicondylar interpositional spacer is considered investigational; the policy statement remains unchanged.
Update
A recent literature search of the MEDLINE database was performed and no new clinical reports were identified.]
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Horizon BCBSNJ Medical Policy Development Process:
This Horizon BCBSNJ Medical Policy (the “Medical Policy”) has been developed by Horizon BCBSNJ’s Medical Policy Committee (the “Committee”) consistent with generally accepted standards of medical practice, and reflects Horizon BCBSNJ’s view of the subject health care services, supplies or procedures, and in what circumstances they are deemed to be medically necessary or experimental/ investigational in nature. This Medical Policy also considers whether and to what degree the subject health care services, supplies or procedures are clinically appropriate, in terms of type, frequency, extent, site and duration and if they are considered effective for the illnesses, injuries or diseases discussed. Where relevant, this Medical Policy considers whether the subject health care services, supplies or procedures are being requested primarily for the convenience of the covered person or the health care provider. It may also consider whether the services, supplies or procedures are more costly than an alternative service or sequence of services, supplies or procedures that are at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of the relevant illness, injury or disease. In reaching its conclusion regarding what it considers to be the generally accepted standards of medical practice, the Committee reviews and considers the following: all credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, physician and health care provider specialty society recommendations, the views of physicians and health care providers practicing in relevant clinical areas (including, but not limited to, the prevailing opinion within the appropriate specialty) and any other relevant factor as determined by applicable State and Federal laws and regulations.
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Index:
Unicondylar Interpositional Spacer as a Treatment of Unicompartmental Arthritis of the Knee
Interpositional Spacer, Unicondylar
Spacer, Interpositional Unicondylar
UniSpacer
OrthoGlide Medical Knee Implant
Unicondylar Interpositional Spacer Osteoimplant
Knee Interpositional Mini-Repair System
References:
1. Hallock RH, Fell BM. Unicompartmental tibial hemiarthroplasty: early results of the UniSpacer knee. Clin Orthop Relat Res 2003; (416):154-63.
2. Sisto DJ, Mitchell IL. UniSpacer arthroplasty of the knee. J Bone Joint Surg Am 2005; 87(8):1706-11.
3. Bailie AG, Lewis PL, Brumby SA et al. The Unispacer knee implant: early clinical results. J Bone Joint Surg Br 2008; 90-B(4):446-450.
4. Catier C, Turcat M, Jacquel A, et al. The Unispacer unicompartmental knee implant: its outcomes in medial compartment knee osteoarthritis. Orthop Traumatol Surg Res 2011 Jun;97(4):410-7.
5. Kock FX, Beckmann J, Lechler P, et al. The 2-year follow-up results of a patient-specific interpositional knee implant. Orthopade 2011 Dec;40(2):1103-10.
6. Bianchi G, Sambri A, Sebastiani E, et al. Is unicondylar osteoarticular allograft still a viable option for reconstructions around the knee? Knee 2016 Aug;23(4):692-7.
7. Witjes S, Gouttebarge V, Kuijer PP, et al. Return to Sports and Physical Activity After Total and Unicondylar Knee Arthroplasty: A Systematic Review and Meta-Analysis. Sports Med 2016 Feb;46(2):269-92.
8. UpToDate. Overview of surgical therapy of knee and hip osteoarthritis. Literature review current through July 2016. Topic last updated December 4, 2015.
9. Mandl LA, Martin GM. Overview of surgical therapy of knee and hip osteoarthritis. In: UpToDate, Tugwell P, Curtis MR (Eds), UpToDate, Waltham, MA. (Accessed on August 5, 2017.)
10. Goetz J, Baeurle M, Dullien S, Grifka J, Koeck F, Baier C. Postural Stability after Unicondylar Knee Arthroplasty and Patient-Specific Interpositional Knee Spacer. PubMed Biomed Res Int. 2017;2017:5836025. doi: 10.1155/2017/5836025. Epub 2017 Jul 13.
11. Mandl LA, Martin GM. Overview of surgical therapy of knee and hip osteoarthritis. In: UpToDate, Hunter D, Curtis MR (Eds), UpToDate, Waltham, MA. (Accessed on July 23, 2020.)
Codes:
(The list of codes is not intended to be all-inclusive and is included below for informational purposes only. Inclusion or exclusion of a procedure, diagnosis, drug or device code(s) does not constitute or imply authorization, certification, approval, offer of coverage or guarantee of payment.)
CPT*
HCPCS
* CPT only copyright 2020 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.
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Medical policies can be highly technical and are designed for use by the Horizon BCBSNJ professional staff in making coverage determinations. Members referring to this policy should discuss it with their treating physician, and should refer to their specific benefit plan for the terms, conditions, limitations and exclusions of their coverage.
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