Robotic-Assisted Total Knee Arthroplasty: What are Patients' Perspectives, Understanding and Expectations?

BACKGROUND: The rate of using robotic-assisted total knee arthroplasty (RA-TKA) has increased markedly. Understanding how patients view the role of robotics during total knee arthroplasty (TKA) informs shared decision making and facilitate efforts to appropriately educate patients regarding the risks and benefits of robotic assistance. METHODS: A self-administered questionnaire was completed by 440 potential TKA patients at the time of their surgery scheduling. Participants answered 25 questions regarding RA-TKA, socioeconomic factors, and their willingness to pay (WTP) for RA-TKA. Logistic regressions were used to determine if population characteristics and surgeon preferences influenced the patients' perceptions of RA-TKA. RESULTS: There were 39.7% of respondents who said that they had no knowledge regarding RA-TKA. Only 40.7% of participants had expressed a desire for RA-TKA to be used. There were 8.7% who were WTP extra for the use of RA-TKA. Participants believed that the main 3 benefits of RA-TKA compared to conventional methods were: more accurate implant placement (56.2%); better results (49.0%); and faster recovery (32.1%). The main 3 patient concerns were harm from malfunction (55.2%), reduced surgeon role in the procedure (48.1%), and lack of supportive research (28.3%). Surgeon preference of RA-TKA was associated with patient's willingness to have RA-TKA (odds ratio 4.60, confidence interval 2.98-7.81, P < .001), and with WTP extra for RA-TKA (odds ratio 2.05, confidence interval: 1.01-4.26, P = .049). CONCLUSION: Patient knowledge regarding RA-TKA is limited. Nonpeer-reviewed online information may make prospective TKA candidates vulnerable to misinformation and aggressive advertising. The challenge for orthopaedic surgeons is to re-establish control and reliably educate patients about the proven advantages and disadvantages of this emerging technology.

One Year Later: The Lasting Effect of the COVID-19 Pandemic on Elective Hip and Knee Arthroplasty.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (COVID-19) pandemic has continued to generate notable disruption in elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine whether there is any difference in patient characteristics, revenue, and clinical outcomes in patients undergoing THA and TKA after the start of the pandemic. METHODS: We reviewed a consecutive series of 26,493 patients undergoing primary and revision THA and TKA by 48 surgeons in a single arthroplasty practice. We compared demographics, comorbidities, outcomes, and surgeon revenue from THA and TKA procedures from March 2020 to February 2021 with a prepandemic group undergoing a procedure from March 2019 to February 2020. RESULTS: There was a 20% decline in the volume of all cases in the pandemic group ( 11,688 versus 14,664 , P < 0.001). The postpandemic cohort had shorter length of stay (1.58 versus 1.70 days, P = 0.007), had higher rates of home discharge (98% versus 91%, P < 0.001), and were more likely to have their procedure done at an outpatient facility (21% versus 7%, P < 0.001). Even among patients older than 65 years, more pandemic patients underwent a procedure as an outpatient (19% versus 7%, P < 0.001), with no difference in complications or readmissions. Total surgeon charges and payments declined by 17.6% and 16.3%, respectively, during the pandemic ( P = 0.010). CONCLUSION: Although the COVID-19 pandemic resulted in a notable reduction in surgical volume and revenue loss for our practice, we found a marked shift of arthroplasty patients to outpatient facilities with increased rates of home discharge without compromising patient safety.

Topical Cannabidiol (CBD) After Total Knee Arthroplasty Does Not Decrease Pain or Opioid Use: A Prospective Randomized Double-Blinded Placebo-Controlled Trial.

BACKGROUND: Multimodal analgesia has become the standard of care for pain management following total knee arthroplasty (TKA). Cannabidiol (CBD) is increasingly utilized in the postoperative period. The purpose of this study was to analyze the analgesic benefits of topical CBD following primary TKA. METHODS: In this randomized double-blinded placebo-controlled trial, 80 patients undergoing primary unilateral TKA applied topical CBD (CBD; n = 19), essential oil (EO; n = 21), CBD and essential oil (CBD + EO; n = 21), or placebo (PLA; n = 19) thrice daily around the knee for two weeks postoperatively. This supplemented a standardized multimodal analgesic protocol. Outcomes included visual analog scale (VAS) pain and numeric rating scale (NRS) sleep scores (collected on postoperative day [POD] 0, 1, 2, 7, 14, 42), and cumulative postoperative opioid use (42 days). RESULTS: Demographic characteristics were similar among the four cohorts. Preoperative VAS and NRS scores were similar among groups. The CBD cohort had a higher mean VAS pain score on POD 2 compared to the EO cohort (CBD: 69.9 ± 19.3 versus. EO: 51.0 ± 18.2; P = .013). No statistically significant differences existed for VAS scores at other times, and no statistically significant differences were observed for postoperative NRS sleep scores or postoperative opioid use at any time point. CONCLUSION: Utilization of topical CBD in supplement to multimodal analgesia did not reduce pain or opioid consumption, or improve sleep scores following TKA. These results suggest that the local effects of topical CBD are not beneficial for providing additional pain relief after TKA.

Short Interval Staged Bilateral Total Knee Arthroplasty: Safety Compared to Simultaneous and Later Staged Bilateral Total Knee Arthroplasty.

BACKGROUND: Simultaneous bilateral total knee arthroplasty (sim-BTKA) is reported to be safe in a select group of patients. Patients with symptomatic bilateral knee arthritis who are not candidates for sim-BTKA require staged surgery (stag-BTKA). This study aimed to compare the safety and complications associated with sim-BTKA with stag-BTKA performed at 2 time intervals. METHODS: This retrospective study of prospectively collected data includes bilateral TKA cases performed between 2001 and 2019. A cohort of sim-BTKA (n = 2728) was compared to a cohort of stag-BTKA (n = 1658). The staged group was subdivided according to the interval between surgeries: ≤90 days (early) and ≥91 days (later). Multivariate logistic regression analyses were used to adjust for confounding variables. RESULTS: In-hospital complication rates were lower in both arms of the stag-BTKA groups vs the sim-BTKA. The sim-BTKA group had higher odds ratio of anemia, electrolyte disturbances, pulmonary embolism, and respiratory, urinary, gastrointestinal, and neurological complications. Lower rates of all-cause revision were found in stag-BTKA vs sim-BTKA groups. There was a trend toward revision due to deep infection when increasing the interim before the second stag-BTKA procedure. No differences in complication rates after the second surgery were detected between the early and later stag-BTKA. CONCLUSION: This study demonstrates that sim-BTKA is associated with more complications and revisions when compared to stag-BTKA. Performing the second-stage TKA at 90 days or less after the first TKA is not associated with increased risk of complications. Performing sim-BTKA, simply for convenience, is not warranted and should be reserved for a select group of patient matching specific criteria.

Red Cell Distribution Width: Commonly Performed Test Predicts Mortality in Primary Total Joint Arthroplasty.

INTRODUCTION: Mortality after total joint arthroplasty (TJA) has been thoroughly explored. Short and long-term mortality appear to be correlated with patient comorbidities. Red Cell Distribution Width (RDW) is a commonly performed test that reflects the variation in red blood cell size. This study investigated the utility of RDW, when combined with comorbidity indices, in predicting mortality after TJA. METHODS: Using a single institutional database, 30,437 primary TJA were identified. Patient demographics (age, gender, body mass index (BMI), pre-operative hemoglobin, RDW, and Charlson Comorbidity Index(CCI)) were queried. The primary outcome was 1-year mortality after TJA. Anemia was defined as hemoglobin <12g/dL for women and <13 g/dL for men. The normal range for RDW is 11.5-14.5%. A preliminary analysis assessed the bivariate association between demographics, preoperative anemia, RDW, CCI, and all-cause mortality within 1-year after TJA. A multivariate regression model was conducted to determine independent predictors of 1-year mortality. Finally, ROC curves were used to compare AUC of RDW, CCI and the combination of both in predicting 1-year mortality. RESULTS: The mean RDW was 13.6% ± 1.2. Eighteen percent of patients had pre-operative anemia. The mean CCI was 0.4 ± 0.9. RDW, anemia, CCI, and age were significantly associated with a higher incidence of 1-year mortality. RDW, CCI, age, and male sex were found to be independent risk factors for 1-year mortality. RDW (AUC = 0.68) was a better predictor of mortality compared to CCI (AUC = 0.66). The combination of RDW and CCI (AUC = 0.76) predicted 1-year mortality more accurately than CCI or RDW alone. CONCLUSION: RDW appears to be a useful parameter that, when combined with CCI, can predict the risk for 1-year mortality after TJA.

Severe Corrosion of Modular Dual Mobility Acetabular Components Identified During Revision Total Hip Arthroplasty.

There has been a significant increase in the use of modular dual mobility (MDM) acetabular cups for primary and revision total hip arthroplasty (THA) secondary to decreased dislocation rate and increased impingement-free range of motion. Mating of dissimilar metals in THA can result in mechanically assisted crevice corrosion, with increased serum metal ion levels and potentially adverse local tissue reaction that can lead to revision surgery. In this case report, we present a patient who had THA using MDM components, and his follow-up laboratory testing showed asymptomatic elevated serum cobalt level. The patient subsequently developed an intraprosthetic dislocation that required revision surgery. At the time of revision, significant corrosion was noted on the backside of the modular acetabular liner and the inner surface of the titanium shell. Serum cobalt levels returned to normal after revision surgery. This case suggests that mechanically assisted crevice corrosion at the modular surface of MDM components does occur. In addition, we believe surgeons should judiciously use MDM technology only for patients at significantly increased risk of dislocation after THA.

After Incision, the Skin Knife Blade Is No More Contaminated Than a Fresh Knife Blade.

INTRODUCTION: The rationale for discarding the skin knife blade and replacing it with another blade for deeper dissection is to prevent bacteria that may be present on the skin from being carried into the deeper layers of the wound. This practice is very controversial because numerous, yet limited, studies exist that support and refute the findings. The purpose of this study was to directly compare the rate of contamination of a skin knife blade with a control blade. METHODS: We took the surface samples using Replicate Organism Detection and Counting plates of 344 knife blades immediately after making skin incision during the following four types of orthopaedic cases: total hip arthroplasty, total knee arthroplasty, lumbar spine surgery, and cervical spine surgery. At the same time, we sampled 344 control blades. The comparison of positives skin versus control, overall and within each subgroup was done using a bivariate two-sample z-test for the equality of proportions. RESULTS: Overall, 35 (5.1%) of the 688 specimens had a positive result. No difference was noted in the rate of positive cultures for the 344 skin blades 4.9% and the 344 control blades 5.2%. No differences were observed in the rate of positive specimens for skin blades (7.4%, 3.4%, 7.7%, and 3.9%) and control blades (2.5%, 4.1%, 7.7%, and 9.2%) for total hip arthroplasty, total knee arthroplasty, C spine, and L spine, respectively. No differences were observed regarding skin prep, room number, case order, room turnover time, or in-room to incision time. Staphylococus species was the predominant bacteria identified. CONCLUSION: We found no evidence to support the theoretical advantage of changing the knife blade after making skin incision to avoid contamination. Contamination rates were the same for both the skin and control blades overall and for all subgroup analysis.

Global Perspectives on Arthroplasty of Hip and Knee Joints.

There is a broad variation of implantation rates, indications, and types of prostheses used for hip and knee joint replacement procedures among different countries. The establishment of national joint registers has improved knowledge and quality of data related to joint implantation. Comparing reports of different national registries is crucial to determine potential variations in practices among surgeons and arthroplasty centers and to identify topics for future analysis. In this report, data from these registries in addition to manufacturer reports were used to evaluate procedure volumes and implants utilization trends of primary and revision total hip and knee replacement around the world.

The Significance of Osteoarthritis-associated Bone Marrow Lesions in the Knee.

Bone marrow lesions of the knee in patients with osteoarthritis (OA-BML) are an important clinical entity that may explain progressive pain, decreased quality of life, and impaired function. MRI of OA-BMLs demonstrates a region of subchondral bone with hyperintense marrow signal on T2-weighted images. Histopathology retrieval studies have demonstrated that these lesions correlate with microdamage of the trabecular bone, and subsequently, this leads to a vicious cycle of subchondral bone attrition, attempts at repair, pain, and progressive deformity. These lesions have also been linked to accelerated loss of adjacent articular cartilage and increases in the severity of knee pain, prompting patients to seek musculoskeletal care and treatment. Multiple studies have also correlated the presence of an OA-BML with an increased probability of seeking knee arthroplasty. Knowledge of these lesions is important in the context that knee OA is both a cartilage-based and bone-based disease. Further study of OA-BMLs may provide opportunities for early intervention and OA disease-modifying treatments.

Intra-articular Corticosteroid Injection Following Total Knee Arthroplasty: Is It Effective?

BACKGROUND: Total knee arthroplasty (TKA) for the majority of patients with severe knee osteoarthritis provides relief of symptoms and improved function. However, there remains a subset of dissatisfied patients despite an unremarkable workup. A corticosteroid injection (CSI) is a commonly used nonsurgical treatment for painful knee osteoarthritis but its efficacy in a replaced knee remains unknown. METHODS: A retrospective chart review identified primary TKA patients who subsequently received a CSI into a replaced knee from 2015 to 2016 by a single surgeon. Patients receiving a CSI underwent clinical examination, laboratory analysis to rule out infection, and radiographic evaluation before CSI. Patient variables were recorded and a patient satisfaction survey assessed the efficacy of the injection. The survey response rate was 70.1%. RESULTS: Of the 129 responders, 82.9% remembered the injection. The average time from index arthroplasty to injection was median 5.3 months (interquartile range, 2.1-23.4) and 30.8% of patients received more than 1 injection (range, 1-5). Overall, 76.6% reported decreased pain, 57.9% reported increased motion, and 65.4% reported long-term decreased swelling. Improvement lasted greater than 1 month for 56.1% of patients, and overall 84.1% reported improvement (slight to great) in the knee following CSI. No patient developed a periprosthetic joint infection (PJI) within 1 year of injection. CONCLUSION: This study suggests that certain patients following TKA may benefit from a CSI. However, this should only be performed once clinical, radiographic, and laboratory examination has ruled out conditions unlikely to improve long term from a CSI.

Periarticular Ropivacaine Cocktail Is Equivalent to Liposomal Bupivacaine Cocktail in Bilateral Total Knee Arthroplasty.

BACKGROUND: This study compares the effectiveness of 2 commonly used periarticular injection formulations: liposomal bupivacaine and bupivacaine (EXP) and ropivacaine, epinephrine, ketorolac, and clonidine (ROP) in patients undergoing bilateral total knee arthroplasty or unicompartmental knee arthroplasty. METHODS: Twenty-six total knee arthroplasty patients (52 knees) and 3 unicompartmental knee arthroplasty patients (6 knees) undergoing simultaneous, bilateral arthroplasty were randomized to receive periarticular injections in a blinded fashion. Even birth year patients were selected for PAI of EXP in the right knee and ROP in the left knee. This was reversed for odd birth years. Visual analog scale pain scores for each knee and patient perceived difference in knee functional recovery were recorded during physical therapy, throughout the hospitalization. RESULTS: There was no difference in visual analog scale pain scores between the EXP and ROP injected knees at any time point during the first 2 days after surgery. Postoperative pain scores averaged 41.9 mm (range 0-100 mm) for EXP and 43.1 mm (range 0-100 mm) for ROP. Patients were unable to detect a difference in the functional recovery between their knees on postoperative day 0, 1, or 2. No complications as a result of either periarticular injection occurred. CONCLUSION: Periarticular injections of EXP and ROP are equally effective after knee arthroplasty and patients do not appreciate differences between knees as determined by pain score or perceived functional recovery during the first 2 days after bilateral knee arthroplasty. This study demonstrates that a liposomal bupivacaine injection does not add an incremental benefit for pain control compared to a less expensive injection formulation.

Radiolucencies surrounding acetabular components with three-dimensional coatings: artifact or real?

BACKGROUND: Several 2-dimensional and 3-dimensional surfaces are available for cementless acetabular fixation. Plain radiographs are used to assess osseointegration; however, the radiographs are limited by their inability to capture the bone fixation process occurring over the 3-dimensional cup surface. In this cadaveric study, we compared the bone apposition between 2-dimensional and 3-dimensional cups. METHODS: Both types of cups were implanted in 6 cadavers and pelvic radiographs obtained. Each cup was resected from the pelvis with adequate bone around it, and subsequently embedded in a polymer. Six sections of each cup were obtained to examine the metal and bone interface. Photographs and contact radiograph images were obtained for each section, and these were graded to arrive at percent metal-bone contact values for the cups. RESULTS: On average, <30% of the cups' areas displayed radiolucencies on the pelvic radiographs for both cup types. For the section images and radiographs, there was about 80% aggregate contact between the cups and surrounding bone in both cup types. In the 3-dimensional cups group, some inconsistencies were found between the section photographs and the corresponding radiograph images. The radiolucencies observed on the section radiograph could not always be correlated with metal to bone gap on the section photograph. CONCLUSIONS: Good metal-bone contact (75% + contact area) was observed on both cup types. The inconsistencies found in the 3-dimensional cup group may be because of the interaction of radiographs with the unique porous cup surface resulting in artifactual radiolucencies.

Periarticular Liposomal Bupivacaine Injection Versus Intra-Articular Bupivacaine Infusion Catheter for Analgesia After Total Knee Arthroplasty: A Double-Blinded, Randomized Controlled Trial.

BACKGROUND: Intra-articular bupivacaine hydrochloride (HCl) infusion catheters and periarticular injections of liposomal bupivacaine are often used as postoperative local anesthetics. The purpose of this study was to compare the efficacies of these local anesthetics following total knee arthroplasty. METHODS: This study was a superiority trial with a randomized, controlled, double-blinded design. Patients were randomly assigned to either delivery of bupivacaine HCl by the ON-Q* Pain Relief System pump (n = 96) or by an injection of Exparel (liposomal bupivacaine) (n = 104). The primary outcome of this study was cumulative narcotic consumption on postoperative days 0 through 3. Narcotic consumption data were collected retrospectively from in-hospital records while patients were in the hospital. Following discharge, narcotic consumption data were gathered from patient surveys, as were secondary outcomes measures. RESULTS: We did not identify greater narcotic use in the ON-Q* group compared with the Exparel group (p = 0.641). The mean difference between the groups was 0.5 morphine equivalent (95% confidence interval [CI] = -1.7 to +2.8), with the ON-Q* group consuming an average 10.4 morphine equivalents (95% CI = 8.7 to 12.0) compared with 10.9 (95% CI = 9.3 to 12.5) in the Exparel group. There were no significant differences between groups with regard to any of the secondary measures of pain with the exception of pain while walking and pain with physical therapy (p = 0.019 and p = 0.010, respectively), both of which showed an approximately 1-point difference in favor of the ON-Q* group on a visual analog scale (VAS). There were also no differences in the postoperative side effects, including nausea, constipation, or vomiting, or in the rates of study-related complications, patient satisfaction, or length of hospital stay. CONCLUSIONS: Exparel did not have superior efficacy compared with the ON-Q* Pain Relief System as reflected by narcotic consumption, our primary outcome. There were small significant differences, in favor of the ON-Q* group, in 2 secondary measures of pain during activity, but these approximately 1-point VAS differences are unlikely to be clinically relevant. The choice of a local anesthetic modality should be based on a combination of safety, convenience, and cost considerations. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Catastrophic Femoral Head-Stem Trunnion Dissociation Secondary to Corrosion.

BACKGROUND: Modular femoral heads provide procedural enhancement by allowing accurate restoration of hip offset and limb-length equalization. However, corrosion may lead to adverse local tissue reactions. Severe trunnion corrosion can also lead to femoral head dissociation and catastrophic implant failure following primary total hip arthroplasty. METHODS: We describe 5 cases, from our institution, in which the femoral head became dissociated from the femoral stem trunnion secondary to severe corrosion. Possible causes are evaluated. RESULTS: Demographic commonalities among the 5 patients included a body mass index (BMI) of ≥30 kg/m(2) and male sex. All femoral heads were made of cobalt-chromium alloy and were larger-diameter implants (≥36 mm). Four of the 5 patients had a femoral head that increased the neck length above the default on a so-called standard head and 3 of the 5 had a stem with a 127° neck-shaft angle. CONCLUSIONS: Although dissociation of the femoral head from the femoral trunnion following total hip arthroplasty is exceedingly rare, the prevalence may increase with longer follow-up. The dissociation is likely related to multiple factors, including a BMI of ≥30 kg/m(2), male sex, and corrosion resulting from the use of a larger metal head with a neck length of greater than the default and a stem with high offset. It is critical that surgeons be able to recognize this mode of implant failure and appropriately prepare to remove the femoral component during revision surgery. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Knee Arthroplasty After Subchondroplasty: Early Results, Complications, and Technical Challenges.

BACKGROUND: Calcium phosphate bone substitutes (CPBS) are commonly used to augment and repair bone voids and defects after fractures around the knee joint. The purpose of this study was to determine whether prior arthroscopic application of a CPBS, for repair of magnetic resonance imaging-identified subchondral fractures associated with osteoarthritis (procedure referred to as subchondroplasty) adversely affected the performance and/or outcome of subsequent knee arthroplasty. METHODS: Twenty-two patients who had arthroscopic repair of a periarticular fracture combined with use of a CPBS who later had knee arthroplasty were identified. Average follow-up for study patients was 23.5 months (range 12-52 months). These patients were matched demographically and for follow-up duration in a 2:1 ratio to a group of control subjects undergoing arthroplasty who had not undergone prior surgery. RESULTS: Technical challenges related to surgical performance, clinical outcomes, and complications were determined for both the groups. At most recent follow-up, study patients had an average Oxford score of 40.6 (range, 25-48) compared with control subjects with an average score of 40.1 (range, 12-48). There was no difference in complications or surgical complexity between groups, and only standard primary components were used. CONCLUSION: The results of our study suggest that prior arthroscopic repair combined with CPBS of periarticular fractures around the knee does not compromise the early outcomes and surgical performance or increase complications related to subsequent arthroplasty. However, longer follow-up of these patients is warranted to confirm that implant durability remains uncompromised.

MRI findings of subchondroplasty of the knee: a two-case report.

Bone marrow lesions observed in magnetic resonance imaging (MRI) have been recognized as a source of knee pain. Subchondroplasty was developed to treat these lesions with a percutaneous injection of calcium phosphate bone substitute into the bone. As subchondroplasty may potentially become a more common procedure in the treatment of knee osteoarthritis, it is important for radiologists to recognize the typical MRI findings and not to confuse them with other pathology. Here we report the MRI findings for two patients following subchondroplasty.

Vascular Complications After Total Knee Arthroplasty-A Single Institutional Experience.

BACKGROUND: Vascular complications during total knee arthroplasty (TKA) are uncommon but potentially devastating. We evaluated cases of vascular complication during TKA in our high-volume, community hospital system. METHODS: Patients were identified by cross-referencing billing codes for TKA with diagnosis codes for vascular complication during the same hospital stay between January 1, 2010 and December 31, 2014. Clinical and radiographic data, time to diagnosis, intervention, and outcomes were collected. RESULTS: We identified 13 vascular complications in 9951 TKAs (0.13%). Average age was 66.2 years (95% CI: 5.55; range: 54.1-87.9), 12 (92.3%) were female, average body mass index was 32.3 (5.17; 20-50), and average Charlson Comorbidity Index was 4.08 (1.03; 2-7). Black females (relative risk = 18.33, 95% CI: 6.20-54.22) were at particularly high risk. Preoperatively, 6 knees exhibited varus coronal malalignment and 2 valgus malalignment (only 1 >15°). None had flexion contracture >10°. Four knees exhibited vascular calcifications on preoperative radiographs. Twelve were diagnosed and treated the same day as index TKA and 1 on postoperative day 2. All underwent interventions: 9 stents, 2 endarterectomies, 1 thrombectomy, and 1 bypass. One patient sustained a peroneal nerve injury; 3 had persistent stiffness postoperatively that improved after manipulation. There were no revision surgeries, further vascular intervention, compartment syndrome, periprosthetic joint infection, amputation, or mortality. CONCLUSION: Incidence of vascular complications at our community-based hospital system is in line with previous reports. Black race and female gender were significant risk factors. Although outcomes were remarkable for a high rate of stiffness and one peroneal neuropathy, the devastating complications of amputation, compartment syndrome, periprosthetic joint infection, or early mortality were not observed.