MedSolutions, Inc. Clinical Decision Support Tool Diagnostic Strategies

This tool addresses common symptoms and symptom complexes. Requests for patients with atypical symptoms or clinical presentations that are not specifically addressed will require physician review. Consultation with the referring physician, specialist and/or patient’s Primary Care Physician (PCP) may provide additional insight.

COMPREHENSIVE MUSCULOSKELETAL MANAGEMENT GUIDELINES 

2015 MedSolutions, Inc.

CMM-311 Knee Arthroplasty – Total & Partial MedSolutions, Inc. Clinical Decision Support Tool

Common symptoms and symptom complexes are addressed by this tool. Requests for patients with atypical symptoms or clinical presentations that are not specifically addressed will require physician review. Consultation with the referring physician may provide additional insight.

CPT® (Current Procedural Terminology) is a registered trademark of the American Medical Association (AMA). CPT® five digit codes, nomenclature and other data are copyright 2014 American Medical Association. All Rights Reserved. No fee schedules, basic units, relative values or related listings are included in the CPT® book. AMA does not directly or indirectly practice medicine or dispense medical services. AMA assumes no liability for the data contained herein or not contained herein.

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COMPREHENSIVE MUSCULOSKELETAL MANAGEMENT GUIDELINES

CMM-311~Knee Arthroplasty-Total & Partial CMM-311.1 Definition Knee arthroplasty is a surgical procedure, which attempts to reconstruct or replace a malformed or degenerated knee joint with internal hardware. Total knee arthroplasty (TKA) involves surgical reconstruction or replacement of the entire knee joint as a result of bicompartmental or tricompartmental involvement. Partial knee arthroplasty involves surgical reconstruction or replacement of one joint surface of the knee joint as a result of unicompartmental involvement. Total or partial knee revision involves surgical reconstruction or replacement due to failure or complications of previous knee arthroplasty. The Modified Outerbridge Classification is a system that has been developed for judging articular cartilage injury to the knee. This system allows delineation of varying areas of chondral pathology, based on the qualitative appearance of the cartilage surface, and can assist in identifying those injuries that are suitable for repair techniques. The characterization of cartilage in this system is as follows: o Grade l - Softening with swelling o Grade ll - Fragmentation and fissuring less than one square centimeter (1 cm2) o Grade lll - Fragmentation and fissuring greater than one square centimeter (1 cm2) o Grade lV - Subchondral bone exposed. The Kellgren-Lawrence Grading System is a radiographic grading system that has been developed for describing osteoarthritic changes to the knee. When used, the radiographic findings are typically reported within one of the following categories: o Grade I – Doubtful narrowing of joint space and possible osteophytic lipping o Grade II – Definite osteophytes and possible narrowing of joint space o Grade III – Moderate multiple osteophytes, definite narrowing of joint space,

some sclerosis, and possible deformity of bone contour o Grade IV – Large osteophytes, marked narrowing of joint space, severe sclerosis, and definite deformity of bone contour. Non-surgical care, with regard to the treatment of the knee, is defined as any nonsurgical treatment, which has been demonstrated in the scientific literature as efficacious and/or is considered a standard of care in the treatment of knee pain. The types of treatment involved can include, but are not limited to: relative rest/activity modification, physiotherapy modalities, supervised therapeutic exercise, oral medications, bracing, Page 2 of 11

and/or injections (steroid and/or viscosupplementation). The UniSpacer is a small, kidney shaped insert made of cobalt chrome for patients with early stage osteoarthritis of the knee. The UniSpacer is said to treat isolated, moderate degeneration of the medial compartment (Grade III-IV chondromalacia) with no more than minimal degeneration (Grade I-II chondromalacia; no loss of joint space) in the lateral condyle or patellofemoral compartment. The proposed goals of UniSpacer surgery are to relieve pain and to improve joint stability by restoring ligament tension and normal knee alignment. CMM-311.2 General Guidelines  The determination of medical necessity for the performance of knee arthroplasty (total or partial) is always made on a case-by-case basis. CMM-311.3 Indications and Non-Indications Partial Knee Arthroplasty  Partial Knee Arthroplasty (Replacement): Partial (unicompartmental) knee arthroplasty is considered medically necessary when all of the following criteria have been met:  Individual has chronic severe, disabling pain for at least 6 months in duration and a documented loss of knee function to the extent which interferes with their ability to carry out their age appropriate activities of daily living and/or their demands of employment; and  Individual demonstrates unicompartmental degenerative arthritis (KellgrenLawrence Grade IV) with joint space narrowing on weight-bearing  radiographs or M o di f i e d Outerbridge Classification Grade IV changes documented by arthroscopy; and  Individual must have intact, stable ligaments, in particular the Anterior Cruciate Ligament; and  Individual’s knee arc of motion (full extension to full flexion) must be greater than 90º ; and  Individual has undergone a reasonable course of non-surgical care.

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 Partial (unicompartmental) knee arthroplasty is considered not medically necessary when any of the following criteria are present:  Individual has severe Grade III or IV patellofemoral joint arthritis (when unicompartmental arthroplasty to be performed is medial or lateral); or  Individual has previously undergone a High Tibial Osteotomy; or  Individual has a tibial or femoral shaft deformity; or  Individual demonstrates radiographic evidence of medial or lateral subluxation; or  Individual demonstrates a flexion contracture greater than 15º; or  Individual demonstrates a varus deformity greater than 15º or a valgus deformity greater than 20º; or  Individual has an inflammatory arthropathy; or  Individual has an active local or systemic infection; or  Individual demonstrates a severe loss of musculature, neuromuscular compromise or vascular deficiency in the affected limb, rendering the procedure unjustifiable; or  Individual demonstrates osteoporosis or other osseous abnormalities which would make the likelihood of a poor outcome more probable; or  Individual demonstrates a severe lack of collateral ligament integrity leading to joint instability.  Based on a lack of scientific evidence of efficacy and safety, bicompartmental knee arthroplasty and bi-unicompartmental knee arthroplasty as an alternative for total knee replacement is considered experimental, investigational or unproven. Total Knee Arthroplasty  Total Knee Arthroplasty (Replacement) is considered medically necessary when all of the following criteria have been met:  Individual has chronic severe, disabling pain for at least 6 months in duration and a documented loss of knee function to the extent which interferes with their ability to carry out their age appropriate activities of daily living and/or their demands of employment; and  Individual demonstrates bicompartmental or tricompartmental degenerative arthritis (Kellgren-Lawrence Grade IV) with joint space narrowing on weightbearing radiographs or Modified Outerbridge Classification Grade IV changes documented by arthroscopy; and  Individual’s knee arc of motion is not limited to 50º or less; and  Individual has undergone a reasonable course of non-surgical care.

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 Total Knee Arthroplasty (replacement) is considered not medically necessary when any of the following criteria are present:  Individual has an active local or systemic infection; or  Individual demonstrates a severe loss of musculature, neuromuscular compromise or vascular deficiency in the affected limb, rendering the procedure unjustifiable; or  Individual demonstrates osteoporosis or other osseous abnormalities which would make the likelihood of a poor outcome more probable; or  Individual demonstrates a severe lack of collateral ligament integrity leading to joint instability; or  Individual demonstrates over 30 degrees of fixed varus or valgus deformity. Total Knee Revision  Total Knee Revision is considered medically necessary when the following criteria have been met:  Individual has previously undergone a partial or total knee arthroplasty and has developed chronic severe, disabling pain and a documented loss of knee function to the extent which interferes with their ability to carry out their age appropriate activities of daily living and/or their demands of employment; and individual demonstrates one of the following: o Fracture or dislocation of the patella; or o Instability of the components; or o Aseptic loosening; or o Infection; or o Periprosthetic fracture; or o Unexplained pain for greater than six (6) months not responsive to non- surgical management.  Total Knee Revision is considered not medically necessary when any of the following criteria are present:  Individual suffers persistent infection; or  Individual demonstrates poor bone quality; or  Individual demonstrates limited quadriceps or extensor function; or  Individual demonstrates poor skin coverage; or  Individual has a poor vascular status. UniSpacer Based on a lack of scientific evidence of efficacy and safety, the use of the UniSpacer Device is considered experimental, investigational or unproven. Page 5 of 11

CMM-311.4 Procedure (CPT®) Codes This guideline relates to the CPT® code set below. Codes are displayed for informational purposes only. Any given code’s inclusion on this list does not necessarily indicate prior authorization is required. CPT® 27437

Code Description/Definition Arthroplasty, patella; without prosthesis

27438

Arthroplasty, patella; with prosthesis

27440

Arthroplasty, knee, tibial plateau

27441

Arthroplasty, knee, tibial plateau; with debridement and partial synovectomy

27442

Arthroplasty, femoral condyles or tibial plateau(s), knee

27443

Arthroplasty, femoral condyles or tibial plateau(s), knee; with debridement and partial synovectomy

27445

Arthroplasty, knee, hinge prosthesis (e.g. Walldius type)

27446

Arthroplasty, knee, condyle and plateau; medial OR lateral compartment

27447

Arthroplasty, knee, condyle and plateau; medical AND lateral compartments with or without patella resurfacing (total knee Arthroplasty)

27486

Revision of total knee Arthroplasty, with or without allograft; 1 component

27487

Revision of total knee Arthroplasty, with or without allograft; femoral and entire tibial component

27488

Removal of prosthesis, including total knee prosthesis, methylmethacrylate with or without insertion of spacer, knee

27580

Arthrodesis, knee, any technique

This list may not be all inclusive and is not intended to be used for coding/billing purposes. The final determination of reimbursement for services is the decision of the health plan and is based on the individual’s policy or benefit entitlement structure as well as claims processing rules.

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CMM-311.5 References 1. Altman, R, et al. American College of Rheumatology Subcommittee on Osteoarthritis Guidelines. Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. Arthritis Rheum. 2000;43(9):1905-1915. 2. American Academy of Orthopaedic Surgeons (AAOS). AAOS clinical guideline on osteoarthritis of the knee (phase II). 2003. Available at: http://www.guideline.gov/summary/summary.aspx?doc_id=4584&nbr=3374&ss=6&xl=999. 3. Ang D, Thomas K, Kroenke K. An exploratory study of primary care physician decision making regarding total joint arthroplasty. J Gen Intern Med. 2007 Jan;22(1):74-9 4. Bachmeier C, March L, Cross M, et al. A comparison of outcomes in osteoarthritis patients undergoing total hip and knee replacement surgery. Osteoarthritis Cartilage 2001 Feb;9(2):137-46. 5. Bailie A, Lewis P, Brumby SA et al. The Unispacer knee implant: Early clinical results. J Bone Joint Surg Br. 2008;90(4):446-450. 6. Baldwin J, Rubinstein R. The effect of bone quality on the outcome of in growth total knee arthroplasty. Am J Knee Surg 1996 Sp ring;9(2):45-9; discussion 9-50. 7. Bert J, Gross M, Kline C. Outcome results after total knee arthroplasty: does the patient's physical and mental health improve? Am J Knee Surg 2000 Fall;13(4):223-7. 8. Borus T, Thornhill T. Unicompartmental knee arthroplasty. J Am Acad Orthop Surg. 2008;16(1):918. 9. Bourne R, Rorabeck C, Vaz M, et al. Resurfacing versus not resurfacing the patella during total knee replacement. Clin Orthop 1995 Dec;(321):156-61. 10. Brown T, Diduch D, Moskal J. Component size asymmetry in bilateral total knee arthroplasty. Am J Knee Surg 2001 Spring;14(2):81-4. 11. Bullens P, van Loon C, de Waal Malefijt M, et al. Patient satisfaction after total knee arthroplasty: a comparison between subjective and objective outcome assessments. J Arthroplasty 2001 Sep;16(6):740-7. 12. Callahan C, Drake B, Heck D, et al. Patient outcomes following tricompartmental total knee replacement. A meta-analysis postoperative alignment of total knee replacement. Its effect on survival. JAMA 1994;271(17):1349-57. 13. Callahan C, Drake B, Heck D, et al. Patient outcomes following unicompartmental or bicompartmental knee arthroplasty: A meta-analysis. J Arthroplasty. 1995;10(2):141-150. 14. Christensen C, Crawford J, Olin M, et al. Revision of the stiff total knee arthroplasty. J Arthroplasty 2002 Jun;17(4):409-15. 15. Clark C, Rorabeck C, MacDonald S, et al. Posterior stabilized and cruciate-retaining total knee replacement: a randomized study. Clin Orthop 2001 Nov;(392):208-12. 16. Cohen R, Forrest C, Benjamin J. Safety and efficacy of bilateral total knee arthroplasty. J Arthroplasty 1997 Aug;12(5):497-502. 17. Confalonieri N, Manzotti A, Cerveri P, De Momi E. Bi-unicompartmental versus total knee arthroplasty: A matched paired study with early clinical results. Arch Orthop Trauma Surg. 2008 Aug 12. 18. Deshmukh R, Hayes J, Pinder I. Does body weight influence outcome after total knee arthroplasty? Page 7 of 11

A 1-year analysis. J Arthroplasty 2002 Apr;17(3):315-9. 19. Diduch D, Insall J, Scott W, et al. Total knee replacement in young, active patients. Long-term follow-up and functional outcome. J Bone Joint Surg Am 1997 Apr;79(4):575-82. 20. Dieppe P, Basler H, Chard J, et al. Knee replacement surgery for osteoarthritis: Effectiveness, practice variations, indications and possible determinants of utilization. Rheumatology (Oxford) 1999;38(1):73-83. 21. Elke R, Meier G, Warnke K, et al. Outcome analysis of total knee-replacements in patients with rheumatoid arthritis versus osteoarthritis. Arch Orthop Trauma Surg 1995;114(6):330-4. 22. Escobar A. Quintana JM. Arostegui I. Et al. Development of explicit criteria for total knee replacement. International Journal of Technology Assessment in Health Care. 19(1):57-70, 2003. 23. Escobar A. Quintana J. Bilbao A. et al. Effect of patient characteristics on reported outcomes after total knee replacement. Rheumatology. 46(1):112-9, 2007 Jan. 24. Escobar A. Quintana J. Bilbao A. et al. Responsiveness and clinically important differences for the WOMAC and SF-36 after total knee replacement. Osteoarthritis & Cartilage. 15(3):273-80, 2007 Mar. 25. Ethgen O, Bruyère O, Richy F, et al. Health-related quality of life in total hip and total knee arthroplasty. A qualitative and systematic review of the literature. J Bone Joint Surg Am. 2004 May;86-A(5):963-74 26. Ewald F, Wright R, Poss R, et al. Kinematic total knee arthroplasty: a 10- to 14-year prospective follow-up review. J Arthroplasty 1999 Jun;14(4):473-80. 27. Fortin P, Clarke A, Joseph L, et al. Outcomes of total hip and knee replacement: preoperative functional status predicts outcomes at six months after surgery. Arthritis Rheum 1999 Aug;42(8):1722-8. 28. Fuchs S, Rolauffs B, Plaumann T, et al. Clinical and functional results after the rehabilitation period in minimally-invasive unicondylar knee arthroplasty patients. Knee Surg Sports Traumatol Arthrosc. 2005;13(3):179-186. 29. Geller J, Yoon R, Macaulay W. Unicompartmental knee arthroplasty: A controversial history and a rationale for contemporary resurgence. J Knee Surg. 2008;21(1):7-14. 30. Gill G, Joshi A, Mills D. Total condylar knee arthroplasty. 16- to 21-year results. Clin Orthop 1999 Oct;(367):210-5. 31. Glassman, Andrew, Lachiewicz, et al. Chapter 9 Unicompartmental, Patellofemoral and Bicompartmental Arthroplasty. Orthopaedic Knowledge Update: Hip and Knee Reconstruction 4th ed. 2011. 107 & 109. 32. Griffen T, Maddern G, Rowden N, et al. Unicompartmental knee arthroplasty for unicompartmental osteoarthritis: A systematic review. ASERNIP-S Report; 44. North Adelaide, SA: Royal Australasian College of Surgeons, Australian Safety and Efficacy Register of New Interventional Procedures (ASERNIP) - Surgical; 2005. 33. Griffin F, Scuderi G, Insall J, et al. Total knee arthroplasty in patients who were obese with 10 years follow-up. Clin Orthop 1998 Nov;(356):28-33. 34. Griffin T, Rowden N, Morgan D, et al. Unicompartmental knee arthroplasty for the treatment of unicompartmental osteoarthritis: A systematic study. ANZ J Surg. 2007;77(4):214-221. 35. Harwin S. Patellofemoral complications in symmetrical total knee arthroplasty. J Arthroplasty 1998 Page 8 of 11

Oct;13(7):753-62. 36. Hawker G, Wright J, Coyte P, et al. Health-related quality of life after knee replacement. J Bone Joint Surg Am 1998 Feb;80(2):163-73. 37. Hawker G, Guan J, Croxford R, Cet al. A prospective population-based study of the predictors of undergoing total joint arthroplasty. Arthritis Rheum. 2006 Oct;54(10):3212-20. 38. Heck D, Robinson R, Partridge C, et al. Patient outcomes after knee replacement. Clin Orthop 1998 Nov;(356):93-110. 39. Insall J, Dethmers D. Revision of total knee arthroplasty. Clinical Orthopaedics & Related Research 1982;170:123-30. 40. Jones C, Beaupre L, Johnston D, Suarez-Almazor ME. Total joint arthroplasties: current concepts of patient outcomes after surgery. Rheum Dis Clin North Am. 2007 Feb;33(1):71-86. 41. Jones C, Voaklander D, Johnston D, et al. The effect of age on pain, function, and quality of life after total hip and knee arthroplasty. Arch Intern Med 2001 Feb;161(3):454-60. 42. Kellgren J, Lawrence J. Radiological assessment of osteo-arthrosis. Ann Rheum Dis 1957:16:494502 43. Khanna G, Levy B. Oxford unicompartmental knee replacement: Literature review. Orthopedics. 2007;30(5 Suppl):11-14. 44. Konig A, Walther M, Kirschner S, et al. Balance sheets of knee and functional scores 5 years after total knee arthroplasty for osteoarthritis: a source for patient information. J Arthroplasty 2000 Apr;15(3):289-94. 45. Kurtz S, Mowat F, Ong Ket al. Prevalence of primary and revision total hip and knee arthroplasty in the United States from 1990 through 2002. J Bone Joint Surg Am. 2005 Jul;87(7):1487-97. 46. Lingard E, Sledge C, Learmonth I; Kinemax Outcomes Group. Patient expectations regarding total knee arthroplasty: differences among the United States, United Kingdom, and Australia. J Bone Joint Surg Am. 2006 Jun;88(6):1201-7. 47. Liu T, Chen S. Simultaneous bilateral total knee arthroplasty in a single procedure. Int Orthop 1998;22(6):390-3. 48. Mahomed N, Liang M, Cook E, et al. The importance of patient expectations in predicting functional outcomes after total joint arthroplasty. J Rheumatol. 2002 Jun;29(6):1273-9. 49. Mancuso C, Ranawat C, Esdaile J, et al. Indications for total hip and total knee arthroplasties. Results of orthopaedic surveys. J Arthroplasty 1996 Jan;11(1):34-46. 50. Martin S, McManus J, Scott R, et al. Press-fit condylar total knee arthroplasty. 5- to 9-year followup evaluation. J Arthroplasty 1997 Sep;12(6):603-14. 51. Matsueda M, Gustilo R. Subvastus and medial parapatellar approaches in total knee arthroplasty. Clin Orthop 2000 Feb;(371):161-8. 52. McGinty, John B, Burkhart, Stephen S. Operative Arthroscopy. 1 Philadelphia: Lippincott, Williams & Wilking. 2003. 283. eBook 53. Meding J, Ritter M, Faris P, et al. Does the preoperative radiographic degree of osteoarthritis correlate to results in primary total knee arthroplasty? J Arthroplasty 2001 Jan;16(1):13-6. 54. Miyasaka K, Ranawat C, Mullaji A. 10 to 20-year follow-up of total knee arthroplasty for valgus deformities. Clin Orthop 1997 Dec;(345):29-37. Page 9 of 11

55. Mont M, Stuchin S, Paley D, et al. Different surgical options for monocompartmental osteoarthritis of the knee: High tibial osteotomy versus unicompartmental knee arthroplasty versus total knee arthroplasty: Indications, techniques, results, and controversies. Instr Course Lect. 2004;53:265283. 56. Montin L, Leino-Kilpi H, Suominen T, Lepistö J. A systematic review of empirical studies between 1966 and 2005 of patient outcomes of total hip arthroplasty and related factors. J Clin Nurs. 2008 Jan;17(1):40-5. 57. Murray, Goodfellow, O’Connor, et al. Unicompartmental knee: manual for surgical techniques. Biomet. 2004; 1-40. 58. Nazarian D, Mehta S, Booth Jr R. A comparison of stemmed and unstemmed components in revision knee arthroplasty. Clin Orthop 2002 Nov;(404):256-62. 59. Ontario Ministry of Health and Long-Term Care, Medical Advisory Secretariat (MAS). Total knee replacement. Health Technology Literature Review. Toronto, ON: MAS; June 2005. 60. O'Rourke M, Callaghan J, Goetz D, et al. Osteolysis associated with a cemented modular posterior cruciate-substituting total knee design : five to eight year follow-up. J Bone Jt Surg Am 2002 Aug;84-A(8):1362-71. 61. Orthopedic Network News. 2002 hip and knee implant review. CMS MedPar www.OrthopedicNetworkNews.com. 62. Pandit H, Beard D, Jenkins C, et al. Combined anterior cruciate reconstruction and Oxford unicompartmental knee arthroplasty. J Bone Joint Surg Br. 2006;88(7):887-892. 63. Parvizi J, Seel M, Hanssen A, et al. Patellar component resection arthroplasty for the severely compromised patella. Clin Orthop 2002 Apr;(397):356-61. 64. Pennington D, Swienckowski J, Lutes W, Drake G. Lateral unicompartmental knee arthroplasty: Survivorship and technical considerations at an average follow-up of 12.4 years. J Arthroplasty. 2006;21(1):13-17. 65. Pereira D, Jaffe F, Ortiguera C. Posterior cruciate ligament-sparing versus posterior cruciate ligament sacrificing arthroplasty. Functional results using the same prosthesis. J Arthroplasty 1998 Feb;13(2):138-44. 66. Peyron J. Osteoarthritis. The epidemiologic viewpoint. Clin Orthop 1986;213:13-9. 67. Quintana J, Escobar A, Arostegui I, et al. Health-related quality of life and appropriateness of knee or hip joint replacement. Arch Intern Med. 2006 Jan 23;166(2):220-6. 68. Quintana J. Arostegui I. Escobar A. et al.Prevalence of knee and hip osteoarthritis and the appropriateness of joint replacement in an older population. Archives of Internal Medicine. 168(14):1576-84, 2008 Jul 28. 69. Ranawat C, Luessenhop C, Rodriguez J. The press-fit condylar modular total knee system. Fourto- six-year results with a posterior-cruciate-substituting design. J Bone Jt Surg Am 1997 Mar;79(3):342-8. 70. Rand J, Gustilo R. Comparison of inset and resurfacing patellar prostheses in total knee arthroplasty. J Orthop Surg 1996;4(1):13-22. 71. Rodriguez J, Saddler S, Edelman S, et al. Long-term results of total knee arthroplasty in class 3 and 4 rheumatoid arthritis. J Arthroplasty 1996 Feb;11(2):141-5. Page 10 of 11

72. Rolston L, Bresch J, Engh G, et al. Bicompartmental knee arthroplasty: A bone-sparing, ligamentsparing, and minimally invasive alternative for active patients. Orthopedics. 2007;30(8 Suppl):7073. 73. Saldanha K, Keys G, Svard U, et al. Revision of Oxford medial unicompartmental knee arthroplasty to total knee arthroplasty - results of a multicentre study. Knee. 2007;14(4):275-279. 74. Saleh K, Dykes D, Tweedie R, et al. Functional outcome after total knee arthroplasty revision: a metaanalysis. J Arthroplasty 2002 Dec;17(8):967-77. 75. Santaguida P, Hawker G, Hudak P, et al. Patient characteristics affecting the prognosis of total hip and knee joint arthroplasty: a systematic review. Can J Surg. 2008 Dec;51(6):428-36 76. Schiphof D, Boers M, Bierma-Zeinstra S. “Differences in descriptions of Kellgren and Lawrence grades of knee osreoarthritis” Ann Rheum Dis 2008:67:1034-1036 77. Schonberg M, Marcantonio E, Hamel M. Perceptions of physician recommendations for joint replacement surgery in older patients with severe hip or knee osteoarthritis. J Am Geriatr Soc. 2009 Jan;57(1):82-8. Epub 2008 Nov 21. 78. Schroder H, Berthelsen A, Hassani G, et al. Cementless porous-coated total knee arthroplasty: 10year results in a consecutive series. J Arthroplasty 2001 Aug;16(5):559-67. 79. Scott R. UniSpacer: Insufficient data to support its widespread use. Clin Orthop. 2003;(416):164166. 80. Sisto D, Mitchell I. UniSpacer arthroplasty of the knee. J Bone Joint Surg Am. 2005;87(8):17061711. 81. Stickles B, Phillips L, Brox W, et al. Defining the relationship between obesity and total joint arthroplasty. Obes Res 2001 Mar;9(3):219-23. 82. Walton N, Jahromi I, Lewis P, et al. Patient-perceived outcomes and return to sport and work: TKA versus mini-incision unicompartmental knee arthroplasty. J Knee Surg. 2006;19(2):112-116. 83. Washington State Department of Labor and Industries. UniSpacer Coverage Decision. Coverage Decisions for Medical Technologies and Procedures. Olympia, WA: Washington State Department of Labor and Industries; 2005. Available at: http://www.lni.wa.gov/ClaimsIns/Providers/Treatment/CovMedDev/SpecCovDec/UniSpacer.asp 84. Washington State Department of Labor and Industries. Criteria for knee surgery. Medical Treatment Guidelines. Olympia, WA: Washington State Department of Labor and Industries; December 2003. 85. Wright J, Coyte P, Hawker G, et al. Variation in orthopedic surgeons' perceptions of the Indications for and outcomes of knee replacement. Can Med Assoc J 1995;152:687-97. 86. Zhang W, Moskowitz R, Nuki G, et al. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis Cartilage. 2008;16(2):137-162.

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