Primary Tritanium acetabular components have increased rates of radiolucency associated with inferior clinical outcomes at short-term follow-up

INTRODUCTION

Cementless fixation is the standard for acetabular fixation in primary total hip arthroplasty (THA). There are various surface finishes thought to improve osteointegration, although literature regarding the long-term survival of some of these surfaces is limited. Regardless of design, primary stability is essential to allow for osteointegration. Previous studies have suggested an increased rate of radiolucency and compromised short-term functional outcomes using the Tritanium primary acetabular component (Stryker, Mahwah, NJ). The purpose of this study was to compare the primary Tritanium acetabular component to another contemporary acetabular component as a control group with an established clinical record.

METHODS

444 consecutive, primary THAs performed by a single surgeon from 2008 to 2012 were reviewed. Patients were included if they had a minimum 1-year follow-up. Implant survivorship and modified Harris Hip Scores (mHHS) were recorded for all patients at final follow-up. Radiographs were evaluated by 2 surgeons at 6 weeks, 1 year, and the most recent follow-up for evidence of radiolucency and migration. Components were considered to have evidence of radiographic lucency if they had radiolucency in 2 or more DeLee zones.

RESULTS

198 patients met criteria for inclusion (96 Pinnacle, 102 Tritanium). Average follow-up was 28 (12-72) months. At final follow-up 6.2% of the Pinnacle cups and 29.4% of the Tritanium cups had radiographic evidence of loosening (p < 0.01). The average mHHS for the Tritanium group was 83.1, and 88.4 for the Pinnacle group (p < 0.01). Radiographic evidence of loosening also correlated with a lower mHHS: 75.5 versus 86.4 (p < 0.01). In patients that received Tritanium cups without screw fixation 44.6% showed radiographic evidence of loosening versus 8% that received screw fixation (p < 0.01). In total, 6 patients in the Tritanium group required revision for aseptic loosening of the acetabular component.

CONCLUSIONS

The 30% rate of radiographic loosening in the Tritanium group was significantly higher than the Pinnacle group and correlated with an inferior clinical outcome. Interestingly the use of screw augmentation was protective against radiographic evidence of loosening. This suggests that the Tritanium component may be prone to fibrous in-growth because of inadequate primary stability.

The Efficacy and Safety of Periarticular Injection in Total Joint Arthroplasty: A Direct Meta-Analysis

BACKGROUND

Periarticular injection (PAI) is administered intraoperatively to help reduce postoperative pain and opioid consumption after primary total joint arthroplasty (TJA). The purpose of this study was to evaluate the efficacy and safety of PAI in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine.

METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched for studies published prior to March 2020 on PAI in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of PAI.

RESULTS

Three thousand six hundred and ninety nine publications were critically appraised to provide 60 studies regarded as the best available evidence for an analysis. The meta-analysis showed that intraoperative PAI reduces postoperative pain and opioid consumption. Adding ketorolac or a corticosteroid to a long-acting local anesthetic (eg, ropivacaine or bupivacaine) provides an additional benefit. There is no difference between liposomal bupivacaine and other nonliposomal long-acting local anesthetics. Morphine does not provide any additive benefit in postoperative pain and opioid consumption and may increase postoperative nausea and vomiting. There is insufficient evidence to draw conclusions on the use of epinephrine and clonidine.

CONCLUSION

Strong evidence supports the use of a PAI with a long-acting local anesthetic to reduce postoperative pain and opioid consumption. Adding a corticosteroid and/or ketorolac to a long-acting local anesthetic further reduces postoperative pain and may reduce opioid consumption. Morphine has no additive effect and there is insufficient evidence on epinephrine and clonidine.

Clinical outcomes and survivorship of cementless triathlon total knee arthroplasties: a systematic review

Background

Over the last decade, cementless total knee arthroplasty has demonstrated improved outcomes and survivorship due to advances in technologies of implant design, manufacturing capabilities, and biomaterials. Due to increasing interest in cementless implant design for TKA, our aim was to perform a systematic review of the literature to evaluate the clinical outcomes and revision rates of the Triathlon Total Knee system over the past decade.

Methods

A systematic review of the literature was conducted following PRISMA guidelines for patients who underwent total knee arthroplasty with cementless Triathalon Total Knee System implants. Patients had a minimum of two-year follow-up and data included clinical outcome scores and survivorship data.

Results

Twenty studies were included in the final analysis. The survivability of the Stryker Triathlon TKA due to all causes was 98.7%, with an aseptic survivability of 99.2%. The overall revision incidence per 1,000 person-years was 3.4. Re-revision incidence per 1,000 person-years was 2.2 for infection, and 1.3 for aseptic loosening. The average KSS for pain was 92.2 and the average KSS for function was 82.7.

Conclusions

This systematic review demonstrated excellent clinical outcomes and survivorship at a mean time of 3.8 years. Additional research is necessary to examine the long-term success of the Stryker Triathlon TKA and the use of cementless TKAs in obese and younger populations.

Level of evidence

III.

Higher Tissue Concentrations of Vancomycin Achieved With Low-Dose Intraosseous Injection Versus Intravenous Despite Limited Tourniquet Duration in Primary Total Knee Arthroplasty: A Randomized Trial

BACKGROUND

Vancomycin use has been suggested in high risk patients undergoing total knee arthroplasty (TKA). Previous literature has shown that a lower dose (500 mg) of vancomycin given by intraosseous regional administration (IORA) achieves tissue concentrations 4-10 times higher than intravenous (IV) administration. There is increasing interest in performing TKA with limited tourniquet inflation time. The purpose of this study is to evaluate whether IORA of vancomycin can achieve effective tissue concentrations with limited tourniquet inflation time.

METHODS

Based on prior power calculations, 24 patients undergoing primary TKA were randomized into 2 groups. Group IV-Systemic received weight-based (15 mg/kg) vancomycin with the tourniquet inflated for cementation only. Group IORA received 500 mg vancomycin via IORA after tourniquet inflation which remained inflated for 10 minutes, then reinflated for cementation only. Vancomycin concentrations from tissue, serum, and drain fluid were compared between the 2 groups.

RESULTS

Median vancomycin concentrations in tissue were significantly higher (5-15 times) at all time points in the IORA group. Concentrations in fat at the time of wound closure, after the tourniquet had been deflated for most of the procedure, were 5.2 μg/g in Group IV-Systemic and 33.1 μg/g in Group IORA (P < .001). Median bone concentrations taken just prior to cementation were 7.9 μg/g in Group IV-Systemic and 21.8 μg/g in Group IORA (P = .006). There were no complications related to IORA.

CONCLUSION

For surgeons who wish to limit tourniquet time and when indicated to use vancomycin, low-dose vancomycin IORA achieves tissue concentrations 5-15 times higher than those achieved by IV administration.

LEVEL OF EVIDENCE

Level 1 therapeutic randomized trial.

Antiseptic Irrigation Solutions Used in Total Joint Arthroplasty: A Critical Analysis Review

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There are limited data that directly compare the efficacy of antiseptic irrigation solutions used for the prevention and treatment of periprosthetic joint infections in orthopaedic procedures; there is a notable lack of prospective data.

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For prevention of periprosthetic joint infections, the strongest evidence supports the use of low-pressure povidone-iodine.

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For the treatment of periprosthetic joint infections, delivering multiple solutions sequentially may be beneficial.

Orthopaedic Residency Applicants' Perspective on Program-Based Social Media

Social media and online resources have been used in graduate medical education for years. In addition to an official residency program website, many orthopaedic surgery programs have an established social media presence to interact, educate, and engage with prospective applicants. The role of social media in orthopaedic surgery has significantly expanded in recent years. Despite its increasing use, the specific impact of social media on orthopaedic surgery residency applicants remains unknown.

Orthopaedic Surgery Away Rotations

Away rotations have become a critical factor for a successful orthopaedic surgery residency match. Away rotations significantly improve an applicant's chance of matching into an orthopaedic residency. Away rotations were limited during the 2020 to 2021 academic year because of the COVID-19 pandemic. During the 2021 to 2022 academic year, the American Association of Medical Colleges coalition recommended students only complete 1 rotation outside their home institution, whereas the American Orthopaedic Association Council of Residency Directors argued that multiple rotations should be allowed. We sought to quantify the impact of these restrictions on orthopaedic surgery applicants during the 2020 to 2021 residency application cycle.

A Plant-Based Dietary Intervention for Preoperative Glucose Optimization in Diabetic Patients Undergoing Total Joint Arthroplasty

Purpose. The purpose of this study was to assess the feasibility and effectiveness of a whole food plant-based diet (WFPBD) to improve day of surgery fasting blood glucose (FBG) among patients with type 2 diabetes (T2D). Patients and Methods. Ten patients with T2D scheduled for a total hip or total knee replacement were recruited. For 3 weeks preceding their surgeries, subjects were asked to consume an entirely WFPBD. Frozen WFPBD meals were professionally prepared and delivered to each participant for the 3 weeks prior to surgery. FBG was reassessed on the morning of surgery and compared with preintervention values. Compliance with the diet was assessed. Results. Mean age of subjects and reported duration of diabetes was 65 and 8 years, respectively, average hemoglobin A1c (HbA1c) was 6.6%, and 6 were women. Mean FBG decreased from 127 to 116 mg/dL (P = .2). Five of the subjects experienced improvement in glycemic control, with an average decline of 11 mg/dL. Conclusion. A WFPBD is a potentially effective intervention to improve glycemic control among patients with T2D during the period leading up to surgery. Future controlled trials on a larger sample of patients to assess the impact of a WFPBD on glycemic control and surgical outcomes are warranted.

Surgical Ergonomics and Musculoskeletal Pain in Arthroplasty Surgeons

BACKGROUND

One occupational hazard inherent to total joint replacement surgeons is procedural-related musculoskeletal pain (MSP). The purpose of this study is to identify the prevalence of work-related MSP among arthroplasty surgeons and analyze associated behaviors, attitudes, and beliefs toward surgical ergonomics.

METHODS

A survey was sent to members of the American Association of Hip and Knee Surgeons. The survey included 3 main sections: demographics, symptoms by body part, and attitudes/beliefs/behaviors regarding surgical ergonomics. Pain was reported using the Numeric Rating Scale (0 = no pain, 10 = maximum pain), and well-being was assessed using the Maslach Burnout Inventory.

RESULTS

In total, 586 surgeons completed the survey: 96.1% male and 3.9% female. Most surgeons (96.5%) experience procedural-related MSP. Collectively, surgeons reported an average pain score of 3.7/10 (standard deviation ±1.95). Significant levels of MSP (≥5/10) were most common in the lower back (34.2%), hands (24.8%), and the neck (21.2%). There was a positive association among higher MSP and burnout (P < .001), callousness toward others (P = .005), and decreased overall happiness (P < .001). MSP was also found to have a significant impact on surgeon behavior including the degree of irritability (P < .001), alcohol intake (P < .001), and poor sleep patterns (P < .001).

CONCLUSION

The prevalence of MSP among arthroplasty surgeons is extremely high. This study demonstrates that MSP has a significant impact on career attitudes, lifestyle, and overall surgeon well-being. This study may also contribute to future work to prevent cumulative chronic ailments, disability, and lost productivity of arthroplasty surgeons through promotion of improved ergonomics and risk-reduction strategies.

LEVEL OF EVIDENCE

IV.

Cost-effectiveness of Single vs Double Debridement and Implant Retention for Acute Periprosthetic Joint Infections in Total Knee Arthroplasty: A Markov Model

Background

Periprosthetic joint infection (PJI) is a common cause of revision total knee surgery. Although debridement and implant retention (DAIR) has lower success rates in the chronic setting, it is an accepted treatment of acute PJI, whether postoperatively or with late hematogenous seeding. There are two broad DAIR strategies: single debridement and planned double debridement. The purpose of this study is to evaluate the cost-effectiveness of single vs double DAIR for acute PJI in total knee arthroplasty.

Methods

A decision tree using single or double DAIR as the treatment strategy for acute PJI was constructed. Quality-adjusted life years and costs associated with the two treatment arms were calculated. Treatment success rates, failure rates, and mortality rates were derived from the literature. Medical costs were derived from both the literature and Medicare data. A cost-effectiveness plane was constructed from multiple Monte Carlo trials. A sensitivity analysis identified parameters most influencing the optimal strategy decision.

Results

Double DAIR was the optimal treatment strategy both in terms of the health utility state (82% of trials) and medical cost (97% of trials). Strategy tables demonstrated that as long as the success rate of double debridement is 10% or greater than the success rate of a single debridement, the two-stage protocol is cost-effective.

Conclusions

A double DAIR protocol is more cost-effective than single DAIR from a societal perspective.

A Comprehensive Monetary Analysis of Inpatient Total Hip and Knee Arthroplasties Billed to Medicare by Hospitals: 2011-2017

BACKGROUND

Total joint arthroplasty (TJA) has been a recent target of reimbursement reform. As such, the purpose of this study was to evaluate trends in Medicare reimbursement to hospitals for TJA patients from 2011 to 2017.

METHODS

The Inpatient Utilization and Payment Public Use File was queried for all primary total hip and knee arthroplasty episodes. This file includes all services billed to Medicare via the Inpatient Prospective Payment System. Extracted data included hospital charges and amount paid by Medicare. All data were adjusted for inflation to 2017 US dollars. Multiple linear mixed-model regression analyses were conducted to assess change over time, and geo-modelling was used to represent reimbursement by location.

RESULTS

A total of 3,368,924 primary TJA procedures were billed to Medicare by hospitals from 2011 to 2017 and included in the study. The mean inflation-adjusted Medicare payment to hospitals for DRG 469 decreased from $22,783.66 to $19,604.62 per procedure (-$3179.04; -14.0%; P < .001) and decreased from $13,290.79 to $11,771.54 for DRG 470 (-$1519.25; -11.4%, P = .011) from 2011 to 2017. Meanwhile, the mean charge submitted by hospitals increased by $6483.39 and $5115.60 for DRGs 469 and 470, respectively (+7.4% for 469, +9.3% for 470; P < .001). Medicare reimbursement to hospitals varied by state.

CONCLUSION

During the study period, the mean Medicare reimbursement to hospitals decreased for TJA from 2011 to 2017. Meanwhile, the average charge submitted by hospitals increased. As alternative payment models continue to undergo evaluation and development, these data are important for the advancement of more agreeable reimbursement models in arthroplasty care.

Temporal Analysis of Medicare Physician Reimbursement and Procedural Volume for all Hip and Knee Arthroplasty Procedures Billed to Medicare Part B From 2000 to 2019

BACKGROUND

The purpose of this study was to evaluate trends in annual arthroplasty volume among the Medicare population, as well as assess true Medicare reimbursement to physicians for all hip and knee arthroplasty procedures billed to Medicare since year 2000.

METHODS

The publicly available Medicare Part B National Summary Data File from years 2000 to 2019 was utilized. Collected data included true physician reimbursements for all primary total hip and knee, unicompartmental knee, and revision hip/knee arthroplasty procedures from 2000 to 2019. Monetary data was adjusted for inflation to year 2019 dollars. Change was assessed and compared by procedure type.

RESULTS

From 2000 to 2019, physicians billed Medicare Fee-for-service for 8,363,821 hip and knee arthroplasty procedures. During this time, the annual number of included arthroplasty procedures billed to Medicare increased by 100%. From 2000 to 2019 across all included procedures, the mean physician reimbursement after adjusting for inflation decreased by -$729.82 (-38.9%) per procedure. This varied by procedure type. Unicompartmental knee arthroplasty was the only procedure to experience an increased mean reimbursement when adjusting for inflation, increasing by $241.40 (+16.6%) per procedure from 2000 to 2019.

CONCLUSION

This study demonstrates decreasing Medicare reimbursement to physicians within hip and knee arthroplasty from 2000 to 2019 when adjusting for inflation. This study is important for informing the potential development of more equitable payment models and maintaining access for arthroplasty care moving forward.

Acute or chronic periprosthetic joint infection? Using the ESR ∕ CRP ratio to aid in determining the acuity of periprosthetic joint infections

Introduction: The gold standard for determining the duration of periprosthetic joint infection (PJI) is a thorough history. Currently, there are no well-defined objective criteria to determine the duration of PJI, and little evidence exists regarding the ratio between ESR (mm/h) and CRP (mg/L) in joint arthroplasty. This study suggests the ESR  /  CRP ratio will help differentiate acute from chronic PJI. Methods: Retrospective review of patients with PJI was performed. Inclusion criteria: patients > 18  years old who underwent surgical revision for PJI and had documented ESR and CRP values. Subjects were divided into two groups: PJI for greater (chronic) or less than (acute) 4 weeks and the ESR  /  CRP ratio was compared between them. Receiver-operating characteristic (ROC) curves were evaluated to determine the utility of the ESR  /  CRP ratio in characterizing the duration of PJI. Results: 147 patients were included in the study (81 acute and 66 chronic). The mean ESR  /  CRP ratio in acute patients was 0.48 compared to 2.87 in chronic patients ( p < 0.001 ). The ESR  /  CRP ROC curve demonstrated an excellent area under the curve (AUC) of 0.899. The ideal cutoff value was 0.96 for ESR  /  CRP to predict a chronic ( > 0.96 ) vs. acute ( < 0.96 ) PJI. The sensitivity at this value was 0.74 (95 % CI 0.62-0.83) and the specificity was 0.90 (95 % CI 0.81-0.94). Conclusions: The ESR  /  CRP ratio may help determine the duration of PJI in uncertain cases. This metric may give arthroplasty surgeons more confidence in defining the duration of the PJI and therefore aid in treatment selection.

A Contemporary Classification System of Femoral Bone Loss in Revision Total Hip Arthroplasty

BACKGROUND

Current femoral bone loss classification systems in revision total hip arthroplasty were created at a time when the predominant reconstructive methods used cylindrical porous-coated cobalt-chrome stems. As these stems have largely been replaced by fluted-tapered titanium stems, the ability of these classification systems to help guide implant selection is limited. The purpose of this study was to describe a novel classification system based on contemporary reconstructive techniques.

METHODS

We reviewed the charts of all patients who underwent femoral component revision at our institution from 2007 through 2019. Preoperative images were reviewed, and FBL was rated according to the Paprosky classification and compared to ratings using our institution's NCS. Rates of reoperation at the time of most recent follow-up were determined and compared.

RESULTS

Four-hundred and forty-two femoral revisions in 330 patients with a mean follow-up duration of 2.7 years were identified. Femoral type according to Paprosky and NCS were Paprosky I (36, 8.1%), II (61, 13.8%), IIIA (180, 40.7%), IIIB (116, 26.2%), and IV (49 11.1%) and NCS 1 (35, 7.9%), 2 (364, 82.4%), 3 (8, 1.8%), 4 (27, 6.1%), and 5 (8, 1.8%). Of the 353 nonstaged rTHAs, there were 42 cases requiring unplanned reoperation (11.9%), including infection (18, 5.1%), instability (10, 2.8%), femoral loosening (5, 1.4%), and various other causes (9, 2.5%). The NCS was more predictive of reoperation than the Paprosky classification (Fisher's exact test, P = .008 vs P = ns, respectively).

CONCLUSION

We present a novel femoral classification system that can help guide contemporary implant selection.

The Double DAIR: A 2-Stage Debridement with Prosthesis-Retention Protocol for Acute Periprosthetic Joint Infections

Background

Debridement and implant retention (DAIR) has variable success as a treatment for acute periprosthetic joint infection (PJI), with generally poor outcomes reported in the literature¹. Because of the unacceptably high failure rate of DAIR, we implemented a 2-stage debridement protocol that includes the use of high-dose antibiotic beads between stages for the treatment of acute PJI. In 2 previous studies, with an average follow-up of 3.5 years in each study, we reported overall infection-control rates of 87% and 90%^2,3.

Description

Following exposure of the joint, cultures are obtained, and all modular components are removed, scrubbed, and soaked in an antiseptic solution. A thorough irrigation and debridement with complete synovectomy is performed, followed by temporary reinsertion of the original modular parts. High-dose antibiotic cement beads are inserted into the joint, and the joint is closed. Approximately 5 to 6 days later, a second debridement is performed, the beads are removed, and the new modular, sterile components are implanted. The patient is placed on a course of intravenous and, later, oral antibiotics, in addition to a standard postoperative rehabilitation protocol.

Alternatives

Long-term suppressive antibiotic therapy.One-stage DAIR.One-stage exchange arthroplasty.Two-stage exchange arthroplasty.Resection arthroplasty.Amputation.

Rationale

The treatment of acute PJI has historically consisted of a single irrigation and debridement, with exchange of modular parts and retention of the components, followed by intravenous antibiotic therapy. Despite having lower rates of patient morbidity compared with a 2-stage exchange arthroplasty, this more traditional procedure also has a higher rate of failure, with reported rates as high as 60% to 84%^4-12. The utility of component retention continues to be a topic of debate¹³. Alternatives to component retention include both 1- and 2-stage exchange procedures. Although these modalities offer potentially higher rates of infection control, they are associated with substantial patient morbidity, particularly in patients with well-fixed implants^14-16. Furthermore, exchange procedures may result in substantial iatrogenic bone loss, which can be problematic in revision total joint arthroplasty procedures, in which bone stock may already be limited. The double-DAIR protocol offers infection-control rates that are comparable with those of component-exchange procedures, but with the lower patient morbidity associated with component-retention procedures. Furthermore, the double-DAIR procedure provides the added benefit of retaining important bone stock.

Expected Outcomes

The success rate for the double-DAIR procedure has been reproducible, with infection-control rates of 87% and 90% reported in 2 studies from a single cohort at our institution^2,3. These rates represent a substantial improvement compared with a single irrigation and debridement¹, and are on par with those reported for 2-stage exchange arthroplasty procedures^17-21. The infection-control rates of the double-DAIR procedure did not significantly vary depending on whether infection occurred following a total knee or total hip arthroplasty. However, not surprisingly, patients who underwent debridement following a revision procedure had a lower rate of success (77.1% successful infection control) compared with patients debrided following a primary procedure (93.8% successful infection control). We could not demonstrate an association with organism and success or failure of treatment.Although not significant, there was a trend toward an association between the time from symptom onset to initial treatment and infection control (p = 0.07)². Patients with successful infection control underwent the initial debridement an average of 6.2 days after symptom onset, compared with 10.7 days in patients in whom treatment had failed. Several other studies have demonstrated that successful infection control is associated with earlier initial irrigation and debridement^22-27. We strongly support that, in the setting of confirmed acute PJI, prompt initiation of treatment optimizes the chances for successful infection control.

Important Tips

Thorough debridement is key to successful infection control of infection.Antibiotic-loaded bone cement has repeatedly been demonstrated to be safe, and we recommend its use^28-31.Extended oral antibiotics following debridement with component retention can increase infection-free survivorship³².

Intraosseous Regional Administration of Antibiotic Prophylaxis in Total Knee Arthroplasty

Background

Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA), and perioperative antibiotics are commonly administered to try to mitigate the chance of infection. Intraosseous regional administration (IORA) of prophylactic antibiotics during TKA is a method of antibiotic delivery that has been shown to achieve markedly higher tissue concentrations at much lower doses. Other advantages include ease of administration, ability to time the antibiotic delivery with the surgical start time for maximal effectiveness, and less systemic side effects. The concept is similar to a Bier block, except that IORA involves the use of antibiotics instead of local anesthetic to perfuse the limb and is given via intraosseous rather than intravenous access.

Description

After standard patient preparation and draping, the tourniquet is inflated and an intraosseous needle is inserted into the proximal medial face of the tibia, just medial and slightly above the level of the tubercle. A large syringe containing the desired antibiotic (typically 500 mg vancomycin suspended in normal saline solution) is connected to the needle and the solution is administered over 1 to 2 minutes. The intraosseous needle can then be removed and the surgical procedure proceeds as it normally would per surgeon preference and technique.

Alternatives

Systemic administration of intravenous antibiotics, vancomycin powder, and antibiotic-impregnated cement are alternative options that can be utilized during TKA.

Rationale

IORA has several distinct advantages over other methods of antibiotic delivery, including the ability to (1) deliver antibiotic directly to the surgical bed and avoid systemic delivery, (2) precisely time and quickly administer antibiotics to achieve highest concentrations at the start of and throughout the surgical procedure, and (3) avoid several common and potentially serious side effects, especially those associated with antibiotics such as vancomycin.

Expected Outcomes

This technique for antibiotic delivery achieves markedly higher tissue concentrations compared with systemic administration, without prolonged preoperative infusion times. Intraosseous delivery optimizes timing and reduces the risk of systemic side effects while simultaneously providing equal or enhanced antibiotic prophylaxis in TKA. This delivery mechanism is especially useful in patients who are at high risk for infection and in the revision TKA setting. Further, there is little to no additional risk and the use of this method does not substantially prolong operative time.

Important Tips

The proximal aspect of the tibia is the optimal injection site because the cortex is thinner in this region, making needle insertion easier. Additionally, the metaphyseal bone allows faster flow rates for the infusion. We have found that insertions made slightly more proximally are easier and have faster flow rates. Of note, although the antibiotic is infused into the tibia, as seen in the attached technique video, intraosseous administration achieves rapid uptake into the vascular tree. Therefore, all tissues distal to the tourniquet, including the femur and patella, will receive this optimal dose as well.We prefer the use of a power driver (EZ-IO; Teleflex); however, manual needles (Cook Medical) can also be utilized. Longer needles are available if needed for obese patients.Flow rates are variable and the infusion typically takes 1 to 2 minutes to complete. If the flow rate is slow, twisting and withdrawing the needle slightly (2 to 4 mm) may increase the rate. This contrasts with the 1 to 2-hour intravenous infusion time required when vancomycin is administered systemically.In our experience, intraosseous injection is still successful in the case of a previous high tibial osteotomy, although the flow rate may be slower.In complex revision cases with compromised proximal tibial bone, the medial malleolus is an alternative site for intraosseous administration.Choice of antibiotic: as vancomycin is difficult to adequately administer intravenously, it is ideally suited for IORA. We have studied and utilized a 500-mg dose of vancomycin suspended in a solution of 140 mL of normal saline solution (prepared by our pharmacy). Of note, we have not found rapid infusion of intraosseous vancomycin to cause red-man syndrome as it would with rapid systemic infusion. This is because of the lower dose of 500 mg and the use of the tourniquet, which keeps the antibiotic in the local tissues about the knee without allowing systemic exposure. All patients, regardless of weight or the size of their limb, receive the dose of 500 mg of vancomycin.As cefazolin does not have the same difficulties with intravenous administration, we continue to use standard intravenous prophylaxis with an appropriate weight-based dose of cefazolin prior to incision.Indications for IORA of vancomycin include clinical scenarios in which vancomycin would be administered intravenously. These indications include revision TKA, obesity (body mass index >40 kg/m²), diabetes, beta-lactam allergy, known colonization with methicillin-resistant Staphylococcus aureus (MRSA), patients coming from institutions with a high prevalence of MRSA, previous ligamentous surgical procedure or osteotomies, and current or recent smokers. IORA can be utilized even in the primary TKA setting if the patient is considered high-risk as defined by the criteria above. We also use IORA during reimplantation following 2-stage exchange for PJI and in patients undergoing irrigation and debridement for acute PJI when the organism has been identified preoperatively.

Routine Type and Screens Are Unnecessary for Primary Total Hip and Knee Arthroplasties at an Academic Hospital

Background

Despite decreasing transfusion rates, routine type and screens are frequently used before primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). The aims of this study were to characterize transfusion rates and identify any factors that affect the likelihood of transfusion to determine if it is safe to discontinue routine preoperative type and screens at an academic hospital.

Methods

A retrospective chart review was performed for all patients who underwent primary THA or TKA in 2019 at an academic institution by a fellowship-trained arthroplasty surgeon. Data on preoperative type and screens, transfusion rates, bleeding disorders, and anticoagulation status were obtained. Patients were considered to have a preoperative type and screen if it was performed within 30 days before surgery.

Results

Overall, 379 patients were included in the study. Of these, 210 underwent primary THA and 169 underwent primary TKA. Four patients received transfusions during their hospitalization for a cumulative transfusion rate of 1.06%. No patients received an intraoperative transfusion. One (0.59%) patient received a postoperative transfusion after TKA, and 3 (1.43%) patients received a postoperative transfusion after THA. The mean preoperative hemoglobin of the 4 transfused patients was 10.8 g/dL.

Conclusions

In summary, performing a preoperative routine type and screen is likely unnecessary at academic medical centers. Consideration for obtaining a type and screen may include complex primary surgeries or when patients have preoperative hemoglobin of less than 11 g/dL. Ultimately, preoperative type and screen should be considered on a case-by-case basis using clinical judgment.

Can a Convolutional Neural Network Classify Knee Osteoarthritis on Plain Radiographs as Accurately as Fellowship-Trained Knee Arthroplasty Surgeons?

BACKGROUND

Osteoarthritis (OA) is the leading cause of disability among adults in the United States. As the diagnosis is based on the accurate interpretation of knee radiographs, use of a convolutional neural network (CNN) to grade OA severity has the potential to significantly reduce variability.

METHODS

Knee radiographs from consecutive patients presenting to a large academic arthroplasty practice were obtained retrospectively. These images were rated by 4 fellowship-trained knee arthroplasty surgeons using the International Knee Documentation Committee (IKDC) scoring system. The intraclass correlation coefficient (ICC) for surgeons alone and surgeons with a CNN that was trained using 4755 separate images were compared.

RESULTS

Two hundred eighty-eight posteroanterior flexion knee radiographs (576 knees) were reviewed; 131 knees were removed due to poor quality or prior TKA. Each remaining knee was rated by 4 blinded surgeons for a total of 1780 human knee ratings. The ICC among the 4 surgeons for all possible IKDC grades was 0.703 (95% confidence interval [CI] 0.667-0.737). The ICC for the 4 surgeons and the trained CNN was 0.685 (95% CI 0.65-0.719). For IKDC D vs any other rating, the ICC of the 4 surgeons was 0.713 (95% CI 0.678-0.746), and the ICC of 4 surgeons and CNN was 0.697 (95% CI 0.663-0.73).

CONCLUSIONS

A CNN can identify and classify knee OA as accurately as a fellowship-trained arthroplasty surgeon. This technology has the potential to reduce variability in the diagnosis and treatment of knee OA.

Screening for Periprosthetic Joint Infections With ESR and CRP: The Ideal Cutoffs

BACKGROUND

The purpose of this study was to (1) determine the sensitivity and specificity of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) when screening for a periprosthetic joint infection (PJI) using the standard MSIS cutoff of 30 mm/h and 10 mg/L, respectively, and (2) determine the optimal ESR and CRP cutoff to achieve a sensitivity ≥95%.

METHODS

We retrospectively analyzed 81 PJI patients and 83 noninfected arthroplasty patients. We calculated the sensitivity and specificity (and 95% confidence intervals) for ESR and CRP at thresholds of 30 mm/h and 10 mg/L, respectively. We determined the optimal cutoff for both ESR and CRP to yield a sensitivity greater than or equal to 95%.

RESULTS

The ESR cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 85.2-97.6%) was 10 mm/h, and the CRP cutoff that resulted in a sensitivity ≥ to 95% (95% CI: 87.1-98.4%) was 5 mg/L. The sensitivity and specificity with a combined ESR and CRP of 10 mm/h and 5 mg/L was 100% (95% CI: 94.1-100%) and 54.7% (95% CI: 46.4-62.3%).

CONCLUSION

When using ESR and CRP as a screening tool with the accepted cutoffs of 30 mm/h and 10 mg/L, there is an unacceptably low sensitivity and a high number of false negatives. Therefore, further recommendation must be given to lowering these thresholds to avoid the devastating morbidity of a missed PJI.

LEVEL OF EVIDENCE

III.

Frequency, Cost, and Clinical Significance of Incidental Findings on Preoperative Planning Images for Computer-Assisted Total Joint Arthroplasty

BACKGROUND

The frequency of incidental findings with computer-assisted total joint arthroplasty (CA TJA) preoperative imaging and their clinical significance are currently unknown.

METHODS

We reviewed 573 patients who underwent primary CA TJA requiring planning imaging. Incidental findings were defined as reported findings excluding those related to the planned arthroplasty. Secondary outcomes were additional tests or a delay in surgery. Associated charges were obtained from our institution's website. Charge and incidence data were combined with TJA volumes obtained from the 2016 National Inpatient Sample to model costs to the healthcare system.

RESULTS

Overall, 262 patients (45.7%) had at least 1 incidental finding, 144 patients (25.1%) had 2, and 65 (11.3%) had 3. The most common finding types were musculoskeletal (MSK, 67.7%), digestive (19.5%), cardiovascular (4.9%), and reproductive (4.7%). Also, 9.3% of patients had at least 1 non-MSK incidental finding. Both MSK and non-MSK incidental findings were more common with total hip arthroplasty compared to total knee arthroplasty (67.9% vs 42.2%, P < .0001, and 15.4% vs 8.3%, P < .05, respectively). Further testing was required in 6 cases (1.0%); 1 case required delay in surgery (0.2%). Using the 2016 volume of TJA procedures and assuming a 10%, 15%, and 25%, utilization rate of image-based CA TJA, the annual cost of additional testing was $2.7 million (95% confidence interval, $1.1-$6.3 million), $4.1 million ($1.6-$9.5 million), and $6.9 million (95% confidence interval, $2.7-$15.8 million), respectively.

CONCLUSION

Incidental findings are relatively common on planning images. Stakeholders should be aware of the hidden costs of incidental findings given the increasing popularity of image-based CA TJA.

Minimum Clinically Important Difference: Current Trends in the Orthopaedic Literature, Part I: Upper Extremity: A Systematic Review

BACKGROUND

The minimum clinically important difference (MCID) attempts to define the patient's experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of MCID calculation. Subsequently, we hope that the information presented here will help practitioners to better understand the MCID and to serve as a guide for future efforts to calculate the MCID. The first part of this review focuses on the upper-extremity orthopaedic literature. Part II will focus on the lower-extremity orthopaedic literature.

METHODS

A review was conducted of the 2014 to 2016 publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery. Only clinical science articles utilizing patient-reported outcome measure (PROM) scores were included in the analysis. A keyword search was then performed to identify articles that calculated or referenced the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. MCID utilization in the selected articles was subsequently characterized and recorded.

RESULTS

The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 52 (40.3%) of 129 were related to the upper extremity, 5 (9.6%) of 52 independently calculated MCID values, and 47 (90.4%) of 52 used previously published MCID values as a gauge of their own results. MCID values were considered or calculated for 16 PROMs; 12 of these were specific to the upper extremity. Six different methods were used to calculate the MCID. Calculated MCIDs had a wide range of values for the same PROM (e.g., 8 to 36 points for Constant-Murley scores and 6.4 to 17 points for American Shoulder and Elbow Surgeons [ASES] scores).

CONCLUSIONS

Determining useful MCID values remains elusive and is compounded by the proliferation of PROMs in the field of orthopaedics. The fundamentals of MCID calculation methods should be critically evaluated. If necessary, these methods should be corrected or abandoned. Furthermore, the type of change intended to be measured should be clarified: beneficial, detrimental, or small or large changes. There should also be assurance that the calculation method actually measures the intended change. Finally, the measurement error should consistently be reported.

CLINICAL RELEVANCE

The MCID is increasingly used as a measure of patients' improvement. However, the MCID does not yet adequately capture the clinical importance of patients' improvement.

Patellar osteolysis after total knee arthroplasty with patellar resurfacing: a potentially underappreciated problem

Osteolysis of the patella following total knee arthroplasty is both uncommon and poorly described in the literature. We describe 3 cases of total knee arthroplasty with patella resurfacing that later presented with anterior knee pain with patellar osteolysis without evidence of patellar implant failure: 2 males and 1 female patient, all with bilateral knee osteoarthritis. Osteolysis of the patella was identified radiographically between 2 and 16 years from the index procedure. We theorize that high pressures across the patella-femoral joint, in obese or muscular patients, may play a role in the formation of these patellar osteolytic lesions. We suspect that the prevalence of this phenomenon is under-recognized in the literature and may increase with longer term follow-up and awareness.

Tourniquet Use in Total Knee Arthroplasty

Tourniquet use in total knee arthroplasty has become a controversial topic. There are several benefits of its use including improved visualization, decreased blood loss, shorter operative times, and improved antibiotic delivery. Conversely, there are several significant downsides associated with tourniquet use including postoperative pain, neuromuscular injuries, wound complications, reperfusion injury, increased risk of thrombosis, patellar tracking issues, delayed rehabilitation including decreased postoperative range of motion, and its negative effect on patients with vascular disease. However, objectively, the literature does not definitively push us toward or away from the use of a tourniquet. Furthermore, several alternatives have been developed to help mitigate some of the adverse effects associated with its use. This article summarizes the evidence for and against tourniquet use and provides an evidence-based approach to help guide surgeons in their own practice.