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.

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.

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.

Serum Metal Ion Levels Following Total Hip Arthroplasty With Modular Dual Mobility Components.

Dual mobility acetabular components can reduce the incidence of total hip arthroplasty (THA) instability. Modular dual mobility (MDM) components facilitate acetabular component implantation. However, corrosion can occur at modular junctions. Serum cobalt and chromium levels and Oxford scores were obtained at minimum two year follow-up for 100 consecutive patients who had THA with MDM components. Average Oxford score was 43 (range 13-48). Average serum cobalt and chromium values were 0.7 mcg/L (range, 0.0 to 7.0) and 0.6 mcg/L (range, 0.1 to 2.7), respectively. MARS MRI was performed for four patients with pain and elevated serum cobalt levels. Two of these studies were consistent with adverse local tissue reaction. We recommend use of MDM implants in only patients at high risk for dislocation following THA.

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.

The Effect of Implementing a Multimodal Approach on the Rates of Periprosthetic Joint Infection After Total Joint Arthroplasty.

INTRODUCTION: We examined the efficacy of implementing a multimodal program aimed at reducing the incidence of periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) in a mid-size community hospital. METHODS: An infection reduction committee (IRC) was formed at our hospital in November 2010. The IRC consisted of two orthopaedic surgeons, an infectious disease specialist, an internist with extensive experience in perioperative medical management of TJA patients, an anesthesiologist, the hospital infection control nurse, and two additional nurses. Their goals were to 1) evaluate the current incidence of PJI at our institution, compare it with the reported national data, and consider measures already in place directed at preventing PJI; 2) review and routinely evaluate recently published studies or information obtained from continuing medical education events related to PJI to determine if practice changes were warranted (based on intervention efficacy, cost, and safety) and then develop a plan to implement appropriate alterations in perioperative protocols using a multimodal strategy; and 3) evaluate the effect and safety of newly-introduced infection reduction strategies on the incidence of PJI. RESULTS: In 2008, the incidence of PJI at our hospital was 1.0%. By 2013, this rate had reduced to 0.4%. In absolute numbers, in 2009, 20 of 1,150 TJAs developed a PJI in the 12-month period following partial, primary, or revision TJA. In 2013, PJI occurred in only 4 of 1,053 TJA patients. CONCLUSION: We found that formation of an IRC focused on evaluating and implementing strategies to reduce PJI following TJA can be effective.

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.

Modular Polyethylene Inserts for Total Knee Arthroplasty: Can Surgeons Detect 1-mm Thickness Increments?

BACKGROUND: Some manufacturers have introduced polyethylene (PE) inserts in 1-mm increment thickness options to allow for finer adjustments in total knee arthroplasty kinematics. METHODS: Two surgeons with extensive experience performed 88 total knee arthroplasties using implants with 1-mm PE inserts. After trial components were inserted and the optimal PE thickness was selected, the insert was removed and a trial insert size was randomly chosen from opaque envelopes (1-mm smaller, same size, and 1-mm larger). The knee was re-examined and the surgeon determined which size PE had been placed. RESULTS: Surgeons reliably determined insert thicknesses in 62.5% (55 of 88; P = .050) of trials. Surgeons were not able to accurately detect 1-mm incremental changes of trial PE implants on a consistent basis. CONCLUSION: The potential clinical usefulness of this concept should be further evaluated.

Do Standard Surgical Guides Produce Accurate and Precise Femoral Bone Resections During Total Knee Arthroplasty?

PURPOSE: Accurate alignment and balanced flexion and extension gaps are critical elements in achieving a successful outcome following total knee arthroplasty (TKA). The ability to make accurate and precise bone cuts is essential in the creation of balanced gaps. We sought to determine if one type of modern-day standard surgical instrument using an intramedullary rod and posterior referencing produces accurate and precise distal and posterior femoral bone resections. MATERIALS AND METHODS: Seventy-five consecutive patients undergoing TKA were divided into three groups, with 25 patients in each group receiving one of three implant designs: 25 Stryker Triathlon® CR (Stryker, Mahwah, NJ), 25 Zimmer NexGen® Flex CR (Zimmer, Warsaw, IN), and 25 StelKast Proven Gen-FlexTM CR (StelKast, Pittsburgh, PA). Flexion-extension gap matching was determined using only the medial flexion and extension gaps. Accuracy was determined by comparing actual resection thickness to desired resection thickness. "Optimal" accuracy was considered to be within 1.0mm of desired, and "near-optimal" accuracy was considered to be within 2.0mm of the desired resection thickness. Precision was determined by the variability of resection thicknesses within each system. RESULTS: Data demonstrated a lack of accuracy and precision across all three tested systems, with each system resulting in certain unique tendencies. Only one out of 75 cases resulted in optimal resection accuracy with all three cuts (Zimmer). When lowering the threshold to include both optimal and near-optimal (within 2 mm of error) with all three cuts, only one third of Stryker and Zimmer cases and two thirds of StelKast cases achieved this threshold, representing 44% of cases (33/75). CONCLUSIONS: Improvements in instrumentation to increase accuracy and precision may be warranted. Errors in fixation may be due to the instrumentation itself, and altering instrumentation to include less modularity, provide more stable fixation, and more reliably seal the implant on the femur may be of benefit.

Evaluation of the efficacy and safety of tranexamic acid for reducing blood loss in bilateral total knee arthroplasty.

Tranexamic acid (TA) has been reported to reduce blood loss after total joint arthroplasty; however, the literature is sparse in evaluating its efficacy in simultaneous bilateral total knee arthroplasty (TKA). In this retrospective study of consecutive patients, TA use in bilateral TKA was associated with a significant reduction in perioperative serum hemoglobin drop, as well as allogeneic blood transfusion needs from 50% to 11% of patients. No autologous blood donation or drains were used. There were no venous thromboembolic events reported. Implementation of a systematic intravenous TA protocol in simultaneous bilateral TKA appears highly effective in reducing transfusion requirements, potentially reducing healthcare resource utilization as well as the morbidity and complications associated with allogeneic blood transfusions.

Revision knee arthroplasty for bone loss: choosing the right degree of constraint.

Revision total knee arthroplasty (TKA) in the setting of bone deficiency requires varied levels of constraint to restore knee stability. However, the outcomes between different levels remain controversial. Clinical outcomes for 183 AORI Type I knees, 168 Type II knees and 124 Type III knees utilizing posterior stabilized (PS), unlinked constrained (UC) or hinged prostheses were evaluated with standardized clinical assessment tools and radiographic results over an average of 7.4 years. PS yielded superior knee scores in AORI Type I patients (P<0.05), UC in Type II and III aseptic patients (P<0.05), and a hinge was preferred in septic Type II or III knees (P<0.05). Revision TKA conducted with increased constraint appears effective in the setting of increased bone deficiency.

Why are total knee arthroplasties failing today--has anything changed after 10 years?

The purpose of this study was to determine the frequency and cause of failure after total knee arthroplasty and compare the results with those reported by our similar investigation conducted 10 years ago. A total of 781 revision TKAs performed at our institution over the past 10 years were identified. The most common failure mechanisms were: loosening (39.9%), infection (27.4%), instability (7.5%), periprosthetic fracture (4.7%), and arthrofibrosis (4.5%). Infection was the most common failure mechanism for early revision (<2 years from primary) and aseptic loosening was the most common reason for late revision. Polyethylene (PE) wear was no longer the major cause of failure. Compared to our previous report, the percentage of revisions performed for polyethylene wear, instability, arthrofibrosis, malalignment and extensor mechanism deficiency has decreased.

Aquacel surgical dressing reduces the rate of acute PJI following total joint arthroplasty: a case-control study.

An effort to prevent PJI has led to the development of antimicrobial dressings that support wound healing. We sought to determine whether Aquacel Surgical dressing independently reduces the rate of acute PJI following TJA. A single institution retrospective chart review of 903 consecutive cases who received the Aquacel Surgical dressing and 875 consecutive cases who received standard gauze dressing was conducted to determine the incidence of acute PJI (within 3 months). The incidence of acute PJI is 0.44% in the Aquacel dressing group compared to 1.7% in the standard gauze dressing group (P = 0.005). Multivariate analysis revealed that use of Aquacel dressing was an independent risk factor for reduction of PJI (odds ratio of 0.165, 95% confidence interval: 0.051-0.533). Aquacel Surgical dressing significantly reduces the incidence of acute PJI.

The 2012 Chitranjan Ranawat award: intraarticular analgesia after TKA reduces pain: a randomized, double-blinded, placebo-controlled, prospective study.

BACKGROUND: Postoperative pain after total knee arthroplasty remains one of the most important challenges facing patients undergoing this surgery. Providing a balance of adequate analgesia while limiting the functional impact of regional anesthesia and minimizing opioid side effects is critical to minimize adverse events and improve patient satisfaction. QUESTIONS/PURPOSES: We asked whether bupivacaine delivered through an elastomeric device decreases the (1) patients' perception of pain after TKA; (2) narcotic consumption; and (3) narcotic-related side effects as compared with a placebo. METHODS: In this prospective, double-blind, placebo-controlled study, all patients received standardized regional anesthesia, a preemptive and multimodal analgesic protocol, and a continuous intraarticular infusion at 5 mL/hour through an elastomeric infusion pump. The patients were randomized to receive either an infusion pump filled with (1) 300 mL of 0.5% bupivacaine, the experimental group (n = 75); or (2) 300 mL of 0.9% normal saline solution, the control group (n = 75). Data concerning postoperative pain levels through a visual analog scale, postoperative opioid consumption, opioid-related side effects, and complications were collected and analyzed. RESULTS: Patients in the experimental group receiving the bupivacaine reported a reduction in pain levels in highest, lowest, and current visual analog scale scores compared with the placebo group on the first postoperative day and highest visual analog scale score on postoperative Day 2 along with a 33% reduction in opioid consumption on postoperative Day 2 and a 54% reduction on postoperative Day 3. CONCLUSION: In patients undergoing TKA, continuous intraarticular analgesia provided an effective adjunct for pain relief in the immediate postoperative period without the disadvantages encountered with other analgesic methods.