In addition to the Pearl Diver-based retrospective study by Arshi et al. on one-year complications after outpatient knee replacement, the December 6, 2017 issue of JBJS contains a NSQIP-based retrospective study by Basques et al. that compares 30-day adverse events and readmissions among 1,236 patients who underwent same-day-discharge hip or knee (total or unicompartmental) arthroplasty with an equal number of propensity score-matched patients who were discharged at least 1 calendar day after the procedure.
When analyzing all three procedures together, the authors found no overall between-group differences in the rates of any adverse event (severe or minor) or readmission. However, when authors analyzed individual adverse events, the same-day group had decreased thromboembolic events and increased 30-day reoperations compared to inpatients. Analysis of individual procedures revealed an increased 30-day reoperation rate for same-day total knee arthroplasty (TKA), compared with inpatient TKA. Overall, infection was the most common reason for reoperation and readmission following same-day procedures.
As with the Arshi et al. study, the limitations of the database prevented these authors from accounting for physician or hospital volume. However, they did identify several preoperative patient characteristics that increased the risk of 30-day readmission among same-day patients, and from those findings Basques et al. concluded that “obese patients, older patients [≥85 years of age], and those with diabetes mellitus may not be appropriate candidates for same-day procedures.”
In the December 6, 2017 issue of The Journal, Arshi et al. report on a detailed analysis of a large administrative database, looking specifically at one-year complications associated with outpatient versus standard inpatient knee replacement. This type of analysis is crucial because of the rapidly growing interest in outpatient joint replacement among patients, payers, and the orthopaedic community.
The data convince me that these outpatient procedures should proceed, but with a little more caution. Although the absolute complication rates in both surgical settings were very low, after adjusting for age, sex, and comorbidities, the authors found a higher relative risk of several surgical and medical complications among outpatients—including component failure, infection, knee stiffness requiring manipulation under anesthesia, and deep vein thrombosis.
One important element that is lacking in this analysis is adjustment for surgeon/hospital volume. We know from important work by Katz and others that patients managed at centers and by surgeons with greater volumes of total knee replacement have lower risks of perioperative adverse events.
These results from Arshi et al. are definitely not a call to stop the expansion of outpatient joint replacement protocols. Instead, I think this study should prompt every joint-replacement center to analyze its risk-adjusted inpatient and outpatient outcomes—and to ensure, as these authors emphasize, that outpatients receive the same level of attention to rehabilitation, antibiotic administration, and thromboprophylaxis as inpatients.
Enhancing outpatient knee-replacement protocols will serve local communities well, and the nationwide orthopaedic community will receive further confirmation that outpatient joint replacement is a move in the right direction.
Marc Swiontkowski, MD
An estimated 7 million people living in the US have undergone a total joint arthroplasty (TJA), and the demand for total hip arthroplasty (THA) and total knee arthroplasty (TKA) will almost certainly increase during the next 15 years. But how many people can expect to have an additional TJA after having a first one?
That’s the question Sanders et al. address in their historical cohort study, published in the March 1, 2017 edition of The Journal of Bone & Joint Surgery. They followed more than 4,000 patients who underwent either THA or TKA between 1969 and 2008 to assess the likelihood of those patients undergoing a subsequent, non-revision TJA.
Here’s what they found:
- Twenty years after an initial THA, the likelihood of a contralateral hip replacement was 29%.
- Ten years after an initial THA, the likelihood of a contralateral knee replacement was 6%, and the likelihood of an ipsilateral knee replacement was 2% at 20 years.
- Twenty years after an initial TKA, the likelihood of a contralateral knee replacement was 45%.
- After an initial TKA, the likelihood of a contralateral hip replacement was 3% at 20 years, and the likelihood of an ipsilateral hip replacement was 2% at 20 years.
In those undergoing an initial THA, younger age was a significant predictor of contralateral hip replacement, and in those undergoing an initial TKA, older age was a predictor of ipsilateral or contralateral hip replacement.
The authors conclude that “patients undergoing [THA] or [TKA] can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure in noncognate joints within 20 years of initial arthroplasty.” They caution, however, that these findings may not be generalizable to populations with more racial or socioeconomic diversity than the predominantly Caucasian population they studied.
When Verburg et al. designed their randomized clinical trial, published in the June 15, 2016 edition of The Journal of Bone & Joint Surgery, they hypothesized that a mini-midvastus (MMV) approach to total knee arthroplasty (TKA) would yield better outcomes than a conventional approach. However, during short- and mid-term follow-up (up to 5 years postoperatively) on 84 TKAs (42 in each group), the researchers found no relevant clinical or radiographic differences between the two groups, both of which received the same brand of posterior-stabilized implant.
On average, the MMV procedure took 6 minutes longer, and those in the MMV group had better range of motion on postoperative day 3. On the downside, more wound-healing problems such as blisters were observed in the MMV group, especially in large male patients, which the authors attribute to soft-tissue interactions caused by the use of necessarily large components with small incision lengths.
Verburg et al. concluded that “the advantage of the MMV approach was merely a smaller scar,” and they do not recommend MMV or other minimally invasive/quadriceps-sparing approaches for “larger patients or muscular men.”
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.
The two numbers that you’ll want to remember from the computer model-based cost-effectiveness study by McLawhorn et al. in the January 20, 2016 Journal of Bone & Joint Surgery are $13,910 and $100,000. The first number is an incremental cost-effectiveness ratio (ICER). Here, it’s the estimated added cost per quality-adjusted life year (QALY) for morbidly obese patients (BMI ≥35 kg/m2) with end-stage knee osteoarthritis who undergo bariatric surgery two years prior to total knee arthroplasty (TKA), compared with similar patients who undergo immediate TKA.
The $100,000 is the threshold “willingness to pay” (WTP) that the authors used in their evaluation. Willingness to pay reflects the amount society and healthcare payers such as Medicare and private insurers are willing to pay for a patient to accrue one year lived in perfect health.
Here’s another way to view these findings: Morbidly obese patients who undergo TKA are at increased risk for wound-healing problems, superficial and deep infections, early revision, and poor function. The authors estimated that if bariatric surgery reduces the TKA risks in these patients by at least 16%, on average, the combination of bariatric surgery followed by TKA is more cost-effective than immediate TKA alone.
Because the ICER was much less than the WTP in this model, the authors conclude that “bariatric surgery prior to total knee arthroplasty may be a cost-effective option for improving outcomes in motivated patients with a BMI of ≥35 kg/m2 with end-stage knee osteoarthritis.” However, they are quick to add that “decision modeling cannot simulate reality for every clinical situation.” While this rigorously developed model may provide a decision-making framework for surgeons and policymakers, the authors say, “this approach may be impractical for an individual patient…desiring immediate symptomatic relief from knee osteoarthritis.”
Intraoperative injury to the medial collateral ligament (MCL) is a rare but important complication of total knee arthroplasty (TKA). Surgeons face two basic choices when it happens: intraoperatively converting to a more constrained TKA prosthesis, or primary repair of the MCL followed by protective bracing.
The retrospective review by Bohl et al. in the January 6, 2016 edition of The Journal of Bone & Joint Surgery does not compare those options head-to-head, but with an average follow-up of more than 8 years, it provides solid evidence that intraoperative repair followed by bracing is a successful long-term strategy.
The authors followed 45 TKAs that sustained either an intraoperative midsubstance MCL tear or an avulsion; 35 injuries occurred during a cruciate-retaining procedure, and 10 during a posterior-stabilized TKA. At a mean final follow-up of 99 months:
- There were no symptoms on physical examination of coronal-plane instability
- All patients were capable of community ambulation without an assistive device, and
- The mean HSS knee score had increased from 47 preoperatively to 85.
Five knees (11%) required intervention for stiffness. Although the authors emphasize that “in all cases the brace was set to allow full range of motion of the knee,” bracing may nevertheless have promoted stiffness by inhibiting range of motion in a cohort that included large proportions of obese and morbidly obese patients. This particular finding suggests that range-of-motion exercises should be emphasized after similar surgeries.
Whenever the impact of surgeon volume on patient outcomes for technically complex interventions has been assessed, the following correlation has held: the higher the surgeon volume, the better the patient outcomes. Working with us at the University of Washington in 1997, Dr. Hans Kreder was one of the first to observe this relationship in joint replacement surgery.1 Patients whose hip replacement was performed by a “high-volume” surgeon (>10 hip replacements per year) were significantly less likely to die or have an infection or revision than those whose procedure was performed by a “low-volume” surgeon (<2 hip replacements per year). This makes perfect intuitive sense—the more you do something, the better your skill, and the better the result.
In the study by Liddle et al. in the January 6, 2016 JBJS, the same volume-outcome relationship for knee arthroplasty is confirmed. The relationship is stronger for unicompartmental arthroplasty than it is for total knee arthroplasty (TKA). Again this makes intuitive sense because the “uni” procedure is more dependent on nuanced bone cuts and component placement than TKA, which relies more heavily on the use of guides and jigs.
Does this mean that the end of general orthopaedic surgeons performing joint replacement is at hand? I don’t think so. Many patients will prefer to stay in their community rather than travel to the high-volume surgeon/hospital even after being informed of the volume-outcome relationship. Additionally, joint registries and routine measurement tools now exist that can help lower-volume surgeons monitor their patient outcomes and demonstrate that their results are similar to those of higher-volume surgeons.
Ultimately, all surgeons are responsible for assessing their individual patient outcomes and making that data available for patients who are considering joint arthroplasty.
Marc Swiontkowski, MD
- Kreder HJ, Deyo RA, Koepsell T, Swiontkowski MF, Kreuter W. Relationship between the volume of total hip replacements performed by providers and the rates of postoperative complications in the state of Washington. J Bone Joint Surg [Am] 1997;79(4):485-94.
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 key findings from Level I and II studies cited in the November 18, 2015 Specialty Update on orthopaedic rehabilitation:
- A prospective comparison of patients who received either skilled physical therapy (PT) or a standardized home exercise program after total knee arthroplasty (TKA) found that range of motion and functional outcome were similar in the two groups after two years, but the home program was nearly half the cost of PT.1
- A randomized trial of 198 patients who underwent TKA compared telerehabilitation with face-to-face rehab. After two months, WOMAC and KOOS scores and functional and range-of-motion tests were all noninferior for telerehabilitation.
- A randomized trial of community-dwelling elderly patients who had undergone hip fracture surgery found that an individualized home-based rehab program produced superior functional outcomes, balance, and mobility recovery when compared with a standard, non-structured home exercise program.2
- A claims-data study of 4733 people who underwent hip or knee replacement found a 29% decrease in postoperative acute service utilization among those who had preoperative PT.
- A randomized trial comparing active transcutaneous nerve stimulation (TENS), placebo TENS, and standard care during rehab for TKA found that adding either active or placebo TENS to standard care significantly reduced movement pain in the immediate postoperative period.3
- A randomized study found that in-hospital sling-based range-of-motion therapy had a clinically beneficial effect up to three months after TKA surgery in terms of passive knee flexion range of motion, compared with an in-hospital continuous passive motion protocol.4
- A randomized trial comparing weight-bearing and non-weight-bearing for nonoperative treatment of Achilles tendon ruptures found no significant between-group differences in the Total Rupture Score or heel-rise strength.
- A systematic review and meta-analysis comprising 402 patients who had undergone surgical Achilles tendon repair found that postoperative early weight-bearing and early ankle motion exercises were associated with a lower minor complication rate and greater functional recovery when compared with conventional immobilization.5
- A randomized trial comparing 12 weeks of individualized resistance training to physiotherapy without resistance training in adolescents and young adults with bilateral spastic cerebral palsy found that neither group demonstrated improvements in performance of daily physical activity.6
- A randomized trial of three methods of weight-bearing training (verbal instruction, bathroom scale training, and haptic biofeedback) found that haptic feedback was superior to the other methods at helping patients maintain weight-bearing status.7
Amputation and Prosthetics
- A systematic review of studies comparing rigid versus soft dressings after amputation determined that rigid dressings resulted in significantly shorter time from amputation to fitting of a prosthesis.8
- A randomized trial of phantom pain found that a protocol of progressive muscle relaxation, mental imagery, and phantom exercises yielded more significant reductions in the rate and intensity of phantom pain than a program of standard physical therapy.9
Low Back Pain
- Among patients with low back pain, a three-way randomized trial (standard care, standard care + extensible lumbosacral orthoses, and standard care + inextensible lumbosacral orthoses) found that inextensible lumbar orthoses led to a greater improvement in Oswestry Disability Index scores than the other two approaches.10
- Büker N,,Akkaya S, Akkaya N, Gökalp O, Kavlak E, Ok N, Kıter AE, Kitiş A.Comparison of effects of supervised physiotherapy and a standardized home program on functional status in patients with total knee arthroplasty: a prospective study. J Phys Ther Sci. 2014 Oct;26(10):1531-6. Epub 2014 Oct 28.
- Salpakoski A, Törmäkangas T, Edgren J, Kallinen M, Sihvonen SE, Pesola M,Vanhatalo J, Arkela M, Rantanen T, Sipilä S. Effects of a multicomponent home-based physical rehabilitation program on mobility recovery after hip fracture: a randomized controlled trial. J Am Med Dir Assoc. 2014 May;15(5):361-8. Epub 2014 Feb 20.
- Rakel BA, Zimmerman MB, Geasland K, Embree J, Clark CR, Noiseux NO,Callaghan JJ, Herr K, Walsh D, Sluka KA. Transcutaneous electrical nerve stimulation for the control of pain during rehabilitation after total knee arthroplasty: A randomized, blinded, placebo-controlled trial. Pain. 2014 Dec;155(12):2599-611.Epub 2014 Sep 28.
- Mau-Moeller A, Behrens M, Finze S, Bruhn S, Bader R, Mittelmeier W. The effect of continuous passive motion and sling exercise training on clinical and functional outcomes following total knee arthroplasty: a randomized active-controlled clinical study. Health Qual Life Outcomes. 2014 May 9;12:68.
- Huang J, Wang C, Ma X, Wang X, Zhang C, Chen L. Rehabilitation regimen after surgical treatment of acute Achilles tendon ruptures: a systematic review with meta-analysis. Am J Sports Med. 2015 Apr;43(4):1008-16. Epub 2014 May 2.
- Bania TA, Dodd KJ, Baker RJ, Graham HK, Taylor NF. The effects of progressive resistance training on daily physical activity in young people with cerebral palsy: a randomised controlled trial. Disabil Rehabil. 2015 Jun 9:1-7. [Epub ahead of print].
- Fu MC, DeLuke L, Buerba RA, Fan RE, Zheng YJ, Leslie MP, Baumgaertner MR, Grauer JN. Haptic biofeedback for improving compliance with lower-extremity partial weight bearing. Orthopedics. 2014 Nov;37(11):e993-8.
- Churilov I, Churilov L, Murphy D. Do rigid dressings reduce the time from amputation to prosthetic fitting? A systematic review and meta-analysis. Ann Vasc Surg. 2014 Oct;28(7):1801-8. Epub 2014 Jun 6.
- Brunelli S, Morone G, Iosa M, Ciotti C, De Giorgi R, Foti C, Traballesi M. Efficacy of progressive muscle relaxation, mental imagery, and phantom exercise training on phantom limb: a randomized controlled trial. Arch Phys Med Rehabil. 2015Feb;96(2):181-7. Epub 2014 Oct 23.
- Morrisette DC, Cholewicki J, Logan S, Seif G, McGowan S. A randomized clinical trial comparing extensible and inextensible lumbosacral orthoses and standard care alone in the management of lower back pain. Spine (Phila Pa 1976). 2014 Oct 1;39(21):1733-42.
The final rule from the Centers for Medicare & Medicaid Services (CMS) regulating “episode-of-care” Medicare payments to hospitals for hip and knee replacements includes a postponed start date of April 1, 2016. The originally proposed implementation date was January 1, 2016.
Approximately 800 hospitals nationwide are subject to the new payment model, which makes hospitals eligible for bonuses or penalties, depending on their quality and cost performance from the day of patient admission to 90 days post-discharge. Based on comments about the initial rule by 400 key stakeholders, CMS also agreed to eliminate penalty payments during the first year of implementation.
Because the CMS model—dubbed Comprehensive Care for Joint Replacement, or CJR—permits gainsharing, individual orthopaedic surgeons could benefit financially if hospitals they are affiliated with receive bonuses. The AAOS commended CMS for revising the methodology for calculating the composite quality score and said that the delayed implementation “adds some flexibility,” but the group is still calling for CMS to “postpose the mandatory implementation feature of the program until at least 85 percent of providers have attained meaningful use [of EHRs] or another metric of infrastructure readiness.”