The July 17, 2019 issue of The Journal features another investigation evaluating patellar resurfacing. Despite much research (see related OrthoBuzz post), this topic remains controversial among many total knee arthroplasty (TKA) surgeons. This study, by Vertullo et al., analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry. The findings suggest that routine resurfacing of the patella reduces the risk of revision surgery for TKA patients.
The authors evaluated more than 136,000 TKA procedures after placing the cases into three groups based on the surgeon’s patellar-resurfacing preference: infrequent (<10% of the time), selective (10% to 90% of the time), or routine (≥90% of the time). All of the cases evaluated utilized minimally stabilized components and cemented or hybrid fixation techniques, and they all were performed by surgeons who completed at least 50 TKAs per year.
The authors found that patients in the infrequent-resurfacing cohort had a nearly 500% increased risk of undergoing subsequent patellar revision during the first 1.5 years after TKA, compared to those in the routine-resurfacing cohort. Even more surprising to me was the finding that patients in the selective-resurfacing cohort had a >300% increased risk of needing a patellar revision within the first 1.5 years, compared to those in the routine-resurfacing cohort. In addition, the risk of all-cause revision was 20% higher in the selective cohort compared to the routine cohort.
What struck me most about this study were the differences between the selective and routine cohorts. One of the arguments against routine resurfacing of the patella is that surgeons should decide intra-operatively, on a patient-by-patient basis, whether the osteochondral health and biomechanics of the native patella warrant resurfacing. The findings of Vertullo et al. seem to call that reasoning into question. Although the results of this study add to the evidence supporting the routine resurfacing of the patella during TKA, I would like to reiterate a proviso from my earlier post on this topic: resurfacing is associated with added costs and an increased risk of potential complications.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Based on available data, it appears that most arthroplasty surgeons in the United States (myself included) usually resurface the patella during total knee arthroplasties (TKAs). This strategy is supported by much of the orthopaedic literature, but there is no universal consensus on which approach is best. Internationally, surgeons in some countries resurface the patella <20% of the time.
Amid this debate, the March 6, 2019 JBJS study by Maney et al. utilizes the New Zealand Joint Registry to shine a little more light on the issue. After analyzing close to 60,000 primary TKAs performed by 203 surgeons, the authors found that patients who underwent knee arthroplasty by surgeons who “usually” (>90% of the time) resurfaced the patella had significantly higher patient-reported Oxford Knee Scores at both 6 months and 5 years postoperatively, compared to those who had their knee replacements performed by surgeons who “selectively” (≥10% to ≤90% of the time) or “rarely” (<10% of the time) resurfaced the patella. However, only 7% of the surgeons in the study fell into the usually-resurface category. That fact, along with the authors’ inability to account for possible confounding patient or surgeon factors, imparts some fragility to the study’s data. Just as (or even more) importantly, the authors did not find any differences in revision rates per 100 component years between the three resurfacing strategies, with >92% survival for all implants at 15 years postoperatively.
This study seems to support previously published data suggesting that resurfacing the patella yields functional outcomes that are at least as good as, if not slightly better than, those with not resurfacing the patella. Still, added costs and potential complications are associated with patellar resurfacing, and these results could also be used to support the strategy of surgeons who do not routinely perform that part of a total knee arthroplasty.
While we still don’t know the “best” strategy, this study adds further credence to the notion that there is not a “wrong” technique when it comes to resurfacing the patella, and surgeons should continue to use whichever technique they feel is best for individual patients.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Here is a summary of selected findings from Level I and II studies cited in the January 20, 2016 Specialty Update on adult reconstructive knee surgery:
Nonsurgical Management and Osteotomy
- A Cochrane database review found that land-based therapeutic exercise programs were modestly beneficial to patients with knee arthritis. Individualized programs were more effective than exercise classes or home-exercise programs.1
- A study comparing intravenous administration of tanezumab versus naproxen and placebo in patients with hip and knee osteoarthritis found that tanezumab effectively relieved pain and improved function at week 16.2
- A comparison of platelet-rich plasma (PRP) injections and hyaluronic acid (HA) injections found both treatments to be equally effective in improving knee function and reducing symptoms as measured by the IKDC subjective score.3
- A study comparing opening-wedge and closing-wedge high tibial osteotomy found that among patients who did not go on to conversion to TKA, there were no between-group differences in clinical or radiographic outcomes at six years of follow-up.
Implants, Instrumentation, and Technique
- A comparison of highly cross-linked and conventional polyethylene in posterior cruciate-substituting TKA found no differences in pain, function, and radiographic outcomes at a mean of 5.9 years.
- A randomized study of 140 patients that compared the use of patient-specific instrumentation (PSI) and conventional instrumentation found no differences in clinical, operative, and radiographic results.4
- In a randomized trial of 200 patients, the use of electromagnetic computer navigation resulted in insignificantly fewer outliers from the target alignment, compared with the use of conventional instrumentation. There were no between-group differences in clinical outcomes.5
- In a prospective randomized trial, the use of computer-assisted navigation during TKA resulted in lower systemic embolic loads, compared with TKA performed using conventional intramedullary instrumentation.
- A randomized controlled trial comparing kinematically and mechanically aligned TKA found that kinematic alignment with patient-specific guides provided better pain relief and restored better function and range of motion than mechanical alignment using conventional instruments.6
- A randomized study of selective patellar resurfacing in 327 knees followed for a mean of 7.8 years found higher satisfaction among patients with a resurfaced patella.7
Pain and Blood Management
- A randomized controlled trial comparing femoral and adductor canal blocks found that adductor canal blocks decreased time to discharge readiness without an increase in narcotic consumption.8
- A trial comparing periarticular injections (PAIs) of liposomal bupivacaine with conventional bupivacaine PAI found no between-group differences in VAS pain scores 72 hours postoperatively or in patient narcotic consumption.9
- A double-blinded randomized trial comparing topical versus intravenous administration of tranexamic acid found no significant differences in estimated blood loss or complications.
Rehabilitation and Complications
- A randomized trial of 205 post-TKA patients found no differences in WOMAC scores for pain, function, and stiffness in groups that received telerehabilitation or face-to-face home therapy.
- A randomized trial found that Kinesio Taping helped reduce postoperative pain and swelling and improved knee extension during early postoperative rehabilitation.10
- A trial comparing oral edoxaban and subcutaneous enoxaparin for post-TKA thromboprophylaxis found that edoxaban was the more effective agent. The incidence of bleeding events was similar in both groups.11
- Fransen M, McConnell S, Harmer AR, Van der Esch M, Simic M, Bennell KL.Exercise for osteoarthritis of the knee. Cochrane Database Syst Rev.2015;1:CD004376. Epub 2015 Jan 9.
- Ekman EF, Gimbel JS, Bello AE, Smith MD, Keller DS, Annis KM, Brown MT, WestCR, Verburg KM. Efficacy and safety of intravenous tanezumab for the symptomatic treatment of osteoarthritis: 2 randomized controlled trials versus naproxen. J Rheumatol. 2014 Nov;41(11):2249-59. Epub 2014 Oct 1.
- Filardo G, Di Matteo B, Di Martino A, Merli ML, Cenacchi A, Fornasari P, MarcacciM, Kon E. Platelet-rich plasma intra-articular knee injections show no superiority versus viscosupplementation: a randomized controlled trial. Am J Sports Med. 2015Jul;43(7):1575-82. Epub 2015 May 7.
- Abane L, Anract P, Boisgard S, Descamps S, Courpied JP, Hamadouche M. A comparison of patient-specific and conventional instrumentation for total knee arthroplasty: a multicentre randomised controlled trial. Bone Joint J. 2015 Jan;97-B(1):56-63.
- Blyth MJ, Smith JR, Anthony IC, Strict NE, Rowe PJ, Jones BG. Electromagnetic navigation in total knee arthroplasty-a single center, randomized, single-blind study comparing the results with conventional techniques. J Arthroplasty. 2015Feb;30(2):199-205. Epub 2014 Sep 16.
- Dossett HG, Estrada NA, Swartz GJ, LeFevre GW, Kwasman BG. A randomised controlled trial of kinematically and mechanically aligned total knee replacements: two-year clinical results. Bone Joint J. 2014 Jul;96-B(7):907-13.
- Roberts DW, Hayes TD, Tate CT, Lesko JP. Selective patellar resurfacing in total knee arthroplasty: a prospective, randomized, double-blind study. J Arthroplasty.2015 Feb;30(2):216-22. Epub 2014 Sep 28.
- Machi AT, Sztain JF, Kormylo NJ, Madison SJ, Abramson WB, Monahan AM,Khatibi B, Ball ST, Gonzales FB, Sessler DI, Mascha EJ, You J, Nakanote KA, IlfeldBM. Discharge readiness after tricompartment knee arthroplasty: adductor canal versus femoral continuous nerve blocks-a dual-center, randomized trial.Anesthesiology. 2015 Aug;123(2):444-56
- Schroer WC, Diesfeld PG, LeMarr AR, Morton DJ, Reedy ME. Does extended-release liposomal bupivacaine better control pain than bupivacaine after total knee arthroplasty (TKA)? A prospective, randomized clinical trial. J Arthroplasty. 2015Sep;30(9)(Suppl):64-7. Epub 2015 Jun 3.
- Donec V, Kriščiūnas A.The effectiveness of Kinesio Taping after total knee replacement in early postoperative rehabilitation period. A randomized controlled trial. Eur J Phys Rehabil Med. 2014 Aug;50(4):363-71. Epub 2014 May 13.
- Fuji T, Wang CJ, Fujita S, Kawai Y, Nakamura M, Kimura T, Ibusuki K, Ushida H, Abe K, Tachibana S.Safety and efficacy of edoxaban, an oral factor Xa inhibitor, versus enoxaparin for thromboprophylaxis after total knee arthroplasty: the STARS E-3 trial. Thromb Res. 2014 Dec;134(6):1198-204. Epub 2014 Sep 21.