Clinical Orthopaedics and Related Research®

, Volume 471, Issue 6, pp 1970–1981 | Cite as

Must Bilaterality Be Considered In Statistical Analyses of Total Knee Arthroplasty?

  • Young Gon Na
  • Yeon Gwi Kang
  • Moon Jong Chang
  • Chong Bum Chang
  • Tae Kyun Kim
Clinical Research

Abstract

Background

In studies of TKA, treating each knee as an independent case in patients with bilateral TKAs can lead to errors, because patients with bilateral and unilateral TKAs may achieve different levels of function and because the assumption of statistical independence is violated.

Questions/purposes

We determined whether (1) patients undergoing bilateral TKAs have different demographics and preoperative and postoperative function from those undergoing unilateral TKAs, and (2) means, SEs, and p values change substantially based on how the two cases of bilateral TKAs are treated in statistical analyses.

Methods

We retrospectively compared 513 patients undergoing unilateral TKAs and 602 patients undergoing bilateral TKAs regarding demographics (age, gender, BMI), preoperative and 1-year postoperative function (motion arc, American Knee Society score, patellofemoral score, WOMACTM, SF-36). Each case of a bilateral TKA was treated as independent in the reference analyses. Then changes of mean, SEs, and p values were compared with those of the reference method when three other methods of analysis were used: using mean values of both knees, randomly selecting one side, and using a generalized estimating equation.

Results

Patients undergoing bilateral TKAs had higher female predominance (95% versus 90%) and BMI (27.4 versus 26.1 kg/m2) than those undergoing unilateral TKAs. Although patients undergoing bilateral TKAs had worse preoperative function, they achieved comparable function at 1 year. The mean values did not differ considerably depending on the four methods. The SEs and p values of the reference method were generally the smallest, but the differences appeared negligible.

Conclusions

Our analyses suggest bilaterality can be ignored in the analysis of TKA, since postoperative function is comparable between unilateral and bilateral TKAs and the theoretical errors in statistical analysis had little effect on the results.

References

  1. 1.
    Aglietti P, Buzzi R, De Felice R, Giron F. The Insall-Burstein total knee replacement in osteoarthritis: a 10-year-minimum follow-up. J Arthroplasty. 1999;14:560–565.PubMedCrossRefGoogle Scholar
  2. 2.
    Angst F, Aeschlimann A, Stucki G. Smallest detectable and minimal clinically important differences of rehabilitation intervention with their implications for required sample sizes using WOMAC and SF-36 quality of life measurement instruments in patients with osteoarthritis of the lower extremities. Arthritis Rheum. 2001;45:384–391.PubMedCrossRefGoogle Scholar
  3. 3.
    Bellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol. 1988;15:1833–1840.PubMedGoogle Scholar
  4. 4.
    Bjorgul K, Novicoff WM, Brevig K, Ahlund O, Wiig M, Saleh KJ. Patients with bilateral procedures can be included in total hip arthroplasty research without biasing results. J Arthroplasty. 2011;26:120–123.PubMedCrossRefGoogle Scholar
  5. 5.
    Brown H, Prescott R. Applied Mixed Models in Medicine. Chichester, England; Hoboken, NJ: John Wiley; 2006.Google Scholar
  6. 6.
    Bryant D, Havey TC, Roberts R, Guyatt G. How many patients? How many limbs? Analysis of patients or limbs in the orthopaedic literature: a systematic review. J Bone Joint Surg Am. 2006;88:41–45.PubMedCrossRefGoogle Scholar
  7. 7.
    Buechel FF Sr. Long-term followup after mobile-bearing total knee replacement. Clin Orthop Relat Res. 2002;404:40–50.PubMedCrossRefGoogle Scholar
  8. 8.
    Bullock DP, Sporer SM, Shirreffs TG Jr. Comparison of simultaneous bilateral with unilateral total knee arthroplasty in terms of perioperative complications. J Bone Joint Surg Am. 2003;85:1981–1986.PubMedGoogle Scholar
  9. 9.
    Callahan CM, Drake BG, Heck DA, Dittus RS. Patient outcomes following tricompartmental total knee replacement: a meta-analysis. JAMA. 1994;271:1349–1357.PubMedCrossRefGoogle Scholar
  10. 10.
    Cohen RG, Forrest CJ, Benjamin JB. Safety and efficacy of bilateral total knee arthroplasty. J Arthroplasty. 1997;12:497–502.PubMedCrossRefGoogle Scholar
  11. 11.
    Cross WW 3rd, Saleh KJ, Wilt TJ, Kane RL. Agreement about indications for total knee arthroplasty. Clin Orthop Relat Res. 2006;446:34–39.PubMedCrossRefGoogle Scholar
  12. 12.
    Farquhar S, Snyder-Mackler L. The Chitranjan Ranawat Award: The nonoperated knee predicts function 3 years after unilateral total knee arthroplasty. Clin Orthop Relat Res. 2010;468:37–44.PubMedCrossRefGoogle Scholar
  13. 13.
    Feller JA, Bartlett RJ, Lang DM. Patellar resurfacing versus retention in total knee arthroplasty. J Bone Joint Surg Br. 1996;78:226–228.PubMedGoogle Scholar
  14. 14.
    Felson DT, Anderson JJ, Naimark A, Walker AM, Meenan RF. Obesity and knee osteoarthritis: the Framingham Study. Ann Intern Med. 1988;109:18–24.PubMedCrossRefGoogle Scholar
  15. 15.
    Fick D, Crane T, Shakespeare D. A comparison of bilateral vs. unilateral total knee arthroplasty mobilised using a flexion regime. Knee. 2002;9:285–289.PubMedCrossRefGoogle Scholar
  16. 16.
    Gelber AC, Hochberg MC, Mead LA, Wang NY, Wigley FM, Klag MJ. Body mass index in young men and the risk of subsequent knee and hip osteoarthritis. Am J Med. 1999;107:542–548.PubMedCrossRefGoogle Scholar
  17. 17.
    Havelin LI, Espehaug B, Vollset SE, Engesaeter LB. The effect of the type of cement on early revision of Charnley total hip prostheses: a review of eight thousand five hundred and seventy-nine primary arthroplasties from the Norwegian Arthroplasty Register. J Bone Joint Surg Am. 1995;77:1543–1550.PubMedGoogle Scholar
  18. 18.
    Hickey BA, Kempshall PJ, Metcalfe AJ, Forster MC. Review of Kinemax total knee replacements performed at the NHS treatment centre, Weston-Super-Mare: five-year results. J Bone Joint Surg Br. 2012;94:510–516.PubMedCrossRefGoogle Scholar
  19. 19.
    Hooper GJ, Hooper NM, Rothwell AG, Hobbs T. Bilateral total joint arthroplasty: the early results from the New Zealand National Joint Registry. J Arthroplasty. 2009;24:1174–1177.PubMedCrossRefGoogle Scholar
  20. 20.
    Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res. 1989;248:13–14.PubMedGoogle Scholar
  21. 21.
    Kalisvaart MM, Pagnano MW, Trousdale RT, Stuart MJ, Hanssen AD. Randomized clinical trial of rotating-platform and fixed-bearing total knee arthroplasty: no clinically detectable differences at five years. J Bone Joint Surg Am. 2012;94:481–489.PubMedCrossRefGoogle Scholar
  22. 22.
    Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis. Ann Rheum Dis. 1957;16:494–502.PubMedCrossRefGoogle Scholar
  23. 23.
    Kelly MA, Clarke HD. Long-Term Results of Posterior Cruciate-Substituting Total Knee Arthroplasty. Clin Orthop Relat Res. 2002;404:51–57.PubMedCrossRefGoogle Scholar
  24. 24.
    Kim JM, Moon MS. Squatting following total knee arthroplasty. Clin Orthop Relat Res. 1995;313:177–186.PubMedGoogle Scholar
  25. 25.
    Kim TK, Chang CB, Kang YG, Kim SJ, Seong SC. Causes and predictors of patient’s dissatisfaction after uncomplicated total knee arthroplasty. J Arthroplasty. 2009;24:263–271.PubMedCrossRefGoogle Scholar
  26. 26.
    Kim YH, Choi YW, Kim JS. Simultaneous bilateral sequential total knee replacement is as safe as unilateral total knee replacement. J Bone Joint Surg Br. 2009;91:64–68.PubMedGoogle Scholar
  27. 27.
    Kim YH, Sohn KS, Kim JS. Range of motion of standard and high-flexion posterior stabilized total knee prostheses: a prospective, randomized study. J Bone Joint Surg Am. 2005;87:1470–1475.PubMedCrossRefGoogle Scholar
  28. 28.
    Koh IJ, Kim TK, Chang CB, Cho HJ, In Y. Trends in use of total knee arthroplasty in Korea from 2001 to 2010. Clin Orthop Relat Res. 2012 Oct 4. [Epub ahead of print].Google Scholar
  29. 29.
    Lane GJ, Hozack WJ, Shah S, Rothman RH, Booth RE Jr, Eng K, Smith P. Simultaneous bilateral versus unilateral total knee arthroplasty: outcomes analysis. Clin Orthop Relat Res. 1997;345:106–112.PubMedCrossRefGoogle Scholar
  30. 30.
    Liang K-Y, Zeger SL. Longitudinal data analysis using generalized linear models. Biometrika. 1986;73:13–22.CrossRefGoogle Scholar
  31. 31.
    Lie SA, Engesaeter LB, Havelin LI, Gjessing HK, Vollset SE. Dependency issues in survival analyses of 55,782 primary hip replacements from 47,355 patients. Stat Med. 2004;23:3227–3240.PubMedCrossRefGoogle Scholar
  32. 32.
    Lohmander LS, Gerhardsson de Verdier M, Rollof J, Nilsson PM, Engstrom G. Incidence of severe knee and hip osteoarthritis in relation to different measures of body mass: a population-based prospective cohort study. Ann Rheum Dis. 2009;68:490–496.PubMedCrossRefGoogle Scholar
  33. 33.
    Lozano Calderon SA, Shen J, Doumato DF, Zelicof S. Functional outcomes in high-function-demand patients after total knee arthroplasty. Orthopedics. 2012;35:e681–690.Google Scholar
  34. 34.
    Mancuso CA, Ranawat CS, Esdaile JM, Johanson NA, Charlson ME. Indications for total hip and total knee arthroplasties: results of orthopaedic surveys. J Arthroplasty. 1996;11:34–46.PubMedCrossRefGoogle Scholar
  35. 35.
    March LM, Cross M, Tribe KL, Lapsley HM, Courtenay BG, Cross MJ, Brooks PM, Cass C, Coolican M, Neil M, Pinczewski L, Quain S, Robertson F, Ruff S, Walter W, Zicat B; Arthritis C.O.S.T. Study Project Group. Two knees or not two knees? Patient costs and outcomes following bilateral and unilateral total knee joint replacement surgery for OA. Osteoarthritis Cartilage. 2004;12:400–408.PubMedCrossRefGoogle Scholar
  36. 36.
    McMahon M, Block JA. The risk of contralateral total knee arthroplasty after knee replacement for osteoarthritis. J Rheumatol. 2003;30:1822–1824.PubMedGoogle Scholar
  37. 37.
    Memtsoudis SG, Ma Y, Gonzalez Della Valle A, Mazumdar M, Gaber-Baylis LK, MacKenzie CR, Sculco TP. Perioperative outcomes after unilateral and bilateral total knee arthroplasty. Anesthesiology. 2009;111:1206–1216.PubMedCrossRefGoogle Scholar
  38. 38.
    Mont MA, Mitzner DL, Jones LC, Hungerford DS. History of the contralateral knee after primary knee arthroplasty for osteoarthritis. Clin Orthop Relat Res. 1995;321:145–150.PubMedGoogle Scholar
  39. 39.
    Park KK, Chang CB, Kang YG, Seong SC, Kim TK. Correlation of maximum flexion with clinical outcome after total knee replacement in Asian patients. J Bone Joint Surg Br. 2007;89:604–608.PubMedCrossRefGoogle Scholar
  40. 40.
    Park MS, Kim SJ, Chung CY, Choi IH, Lee SH, Lee KM. Statistical consideration for bilateral cases in orthopaedic research. J Bone Joint Surg Am. 2010;92:1732–1737.PubMedCrossRefGoogle Scholar
  41. 41.
    Poolman RW, Kerkhoffs GM, Struijs PA, Bhandari M, International Evidence-Based Orthopedic Surgery Working Group. Don’t be misled by the orthopedic literature: tips for critical appraisal. Acta Orthop. 2007;78:162–171.PubMedCrossRefGoogle Scholar
  42. 42.
    Powell RS, Pulido P, Tuason MS, Colwell CW Jr, Ezzet KA. Bilateral vs unilateral total knee arthroplasty: a patient-based comparison of pain levels and recovery of ambulatory skills. J Arthroplasty. 2006;21:642–649.PubMedCrossRefGoogle Scholar
  43. 43.
    Ranstam J. Problems in orthopedic research: dependent observations. Acta Orthop Scand. 2002;73:447–450.PubMedCrossRefGoogle Scholar
  44. 44.
    Restrepo C, Parvizi J, Dietrich T, Einhorn TA. Safety of simultaneous bilateral total knee arthroplasty: a meta-analysis. J Bone Joint Surg Am. 2007;89:1220–1226.PubMedCrossRefGoogle Scholar
  45. 45.
    Reuben JD, Meyers SJ, Cox DD, Elliott M, Watson M, Shim SD. Cost comparison between bilateral simultaneous, staged, and unilateral total joint arthroplasty. J Arthroplasty. 1998;13:172–179.PubMedCrossRefGoogle Scholar
  46. 46.
    Ritter MA, Carr KD, Keating EM, Faris PM. Long-term outcomes of contralateral knees after unilateral total knee arthroplasty for osteoarthritis. J Arthroplasty. 1994;9:347–349.PubMedCrossRefGoogle Scholar
  47. 47.
    Ritter MA, Harty LD, Davis KE, Meding JB, Berend M. Simultaneous bilateral, staged bilateral, and unilateral total knee arthroplasty: a survival analysis. J Bone Joint Surg Am. 2003;85:1532–1537.PubMedGoogle Scholar
  48. 48.
    Robertsson O, Ranstam J. No bias of ignored bilaterality when analysing the revision risk of knee prostheses: analysis of a population based sample of 44,590 patients with 55,298 knee prostheses from the national Swedish Knee Arthroplasty Register. BMC Musculoskelet Disord. 2003;4:1.PubMedCrossRefGoogle Scholar
  49. 49.
    Schwarzer G, Schumacher M, Maurer TB, Ochsner PE. Statistical analysis of failure times in total joint replacement. J Clin Epidemiol. 2001;54:997–1003.PubMedCrossRefGoogle Scholar
  50. 50.
    Shah K, Smith J, Jones B, Hullin M. Bilateral total knee replacement under a single anaesthetic, using a cementless implant is not unsafe. Knee Surg Sports Traumatol Arthrosc. 2007;15:269–275.PubMedCrossRefGoogle Scholar
  51. 51.
    Shetty GM, Mullaji A, Bhayde S, Chandra Vadapalli R, Desai D. Simultaneous bilateral versus unilateral computer-assisted total knee arthroplasty: a prospective comparison of early postoperative pain and functional recovery. Knee. 2010;17:191–195.PubMedCrossRefGoogle Scholar
  52. 52.
    Sofat R, Ramkumar U, Wellsted D, Parmar H. Is there a difference between the ability to kneel after unilateral and bilateral total knee replacement? Acta Orthop Belg. 2006;72:578–582.PubMedGoogle Scholar
  53. 53.
    Urban MK, Chisholm M, Wukovits B. Are postoperative complications more common with single-stage bilateral (SBTKR) than with unilateral knee arthroplasty: guidelines for patients scheduled for SBTKR. HSS J. 2006;2:78–82.PubMedCrossRefGoogle Scholar
  54. 54.
    Vaidya SV, Patel MR, Panghate AN, Rathod PA. Total knee arthroplasty: limb length discrepancy and functional outcome. Indian J Orthop. 2010;44:300–307.PubMedCrossRefGoogle Scholar
  55. 55.
    Ware JE Jr, Sherbourne CD. The MOS 36-item short-form health survey (SF-36): I. Conceptual framework and item selection. Med Care. 1992;30:473–483.PubMedCrossRefGoogle Scholar
  56. 56.
    Waters TS, Bentley G. Patellar resurfacing in total knee arthroplasty: a prospective, randomized study. J Bone Joint Surg Am. 2003;85:212–217.PubMedGoogle Scholar
  57. 57.
    Worland RL, Jessup DE, Clelland C. Simultaneous bilateral total knee replacement versus unilateral replacement. Am J Orthop (Belle Mead NJ). 1996;25:292–295.Google Scholar
  58. 58.
    Zeni JA Jr, Snyder-Mackler L. Clinical outcomes after simultaneous bilateral total knee arthroplasty: comparison to unilateral total knee arthroplasty and healthy controls. J Arthroplasty. 2010;25:541–546.PubMedCrossRefGoogle Scholar
  59. 59.
    Zhang Y, Glynn RJ, Felson DT. Musculoskeletal disease research: should we analyze the joint or the person? J Rheumatol. 1996;23:1130–1134.PubMedGoogle Scholar
  60. 60.
    Zhang Y, Xu L, Nevitt MC, Aliabadi P, Yu W, Qin M, Lui LY, Felson DT. Comparison of the prevalence of knee osteoarthritis between the elderly Chinese population in Beijing and whites in the United States: The Beijing Osteoarthritis Study. Arthritis Rheum. 2001;44:2065–2071.PubMedCrossRefGoogle Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2013

Authors and Affiliations

  • Young Gon Na
    • 1
  • Yeon Gwi Kang
    • 1
  • Moon Jong Chang
    • 1
  • Chong Bum Chang
    • 1
    • 2
  • Tae Kyun Kim
    • 1
    • 2
  1. 1.Joint Reconstruction CenterSeoul National University Bundang HospitalSeongnam-siRepublic of Korea
  2. 2.Department of Orthopaedic SurgerySeoul National University College of MedicineSeoulRepublic of Korea

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