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.

Medial Collateral Ligament Reconstruction for Valgus Instability After Total Knee Arthroplasty: A Case Report.

CASE: Medial collateral ligament (MCL) injuries after total knee arthroplasty (TKA) are a rare occurrence. Traditional treatment options include repair and revision to a constrained prosthesis. We present a case of an 80-year-old man who opted for MCL reconstruction in the setting of previous TKA due to late MCL injury from a skiing accident. The presentation, operative techniques, and outcomes of this treatment option are presented. CONCLUSIONS: MCL reconstruction in the setting of TKA can lead to a successful and satisfactory outcome without the need for revision TKA.

Minimizing Surgical Instrument Burden Increases Operating Room Efficiency and Reduces Perioperative Costs in Total Joint Arthroplasty.

BACKGROUND: Optimizing surgical trays to improve operating room efficiency and reduce costs in instrument processing is an under-appreciated strategy for cost containment. This study aimed to assess the economic impact of instrument tray optimization in total joint arthroplasty. METHODS: Thirty-five randomly selected elective primary total knee arthroplasty and total hip arthroplasty performed by 4 fellowship-trained surgeons were analyzed. Type and number of instruments used as well as timing of different steps in the sterilization process were recorded by an independent observer. Using Lean methodology, surgeons identified redundant or underutilized instruments and agreed upon the fewest number needed for each tray. Instrument utilization rates and processing time were analyzed before and after tray modifications. Annual cost savings were calculated based on a processing factor of $0.59-$11.52 per instrument. RESULTS: Only 45.5% of instruments opened for total knee arthroplasty were utilized. After optimization, 28 of 87 (32.2%) instruments were removed and the remainder could be stored in one tray. Mean set-up time decreased from 20.7 to 14.2 minutes, while 40-75 minutes were saved during the sterilization process. For total hip arthroplasty, only 36.0% of instruments were utilized. Using Lean methods, 46 of 112 (41.1%) instruments were removed and tray count was reduced to 2 trays. Mean set-up time decreased from 27.9 to 18.6 minutes, while 45-150 minutes were saved during processing. Average annual savings amounted to $281,298.05. CONCLUSION: Lean methodology can be used to eliminate redundant or underutilized instruments in total joint arthroplasty, improving surgical efficiency and generating substantial cost savings.

Intraoperative Surgeon Administered Adductor Canal Blockade Is Not Inferior to Anesthesiologist Administered Adductor Canal Blockade: A Prospective Randomized Trial.

BACKGROUND: Controlling postoperative pain and reducing opioid requirements after total knee arthroplasty remain a challenge, particularly in an era stressing rapid recovery protocols and early discharge. A single-shot adductor canal blockade (ACB) has been shown to be effective in decreasing postoperative pain. The purpose of the present study is to compare the efficacy of an anesthesiologist administered ACB and a surgeon administered intraoperative ACB. METHODS: Patients undergoing primary total knee arthroplasty were prospectively randomized to receive either an anesthesiologist administered (group 1) or surgeon administered (group 2) ACB using 15 mL of ropivacaine 0.5%. Primary outcomes were pain visual analog scale, range of motion, and opioid consumption. RESULTS: Thirty-four patients were randomized to group 1 and 29 to group 2. Opioid equivalents consumed were equal on postoperative day (POD) 0, 1, and 2. Patients in group 1 had statistically less pain on POD 0, but this did not reach clinical significance and there was no difference in pain on POD 1 or 2. Patients in group 1 had significantly increased active flexion POD 1, but there was no difference in active flexion on POD 0 or 6 weeks postop. There was no difference in patient satisfaction with pain control or short-term functional outcomes. CONCLUSION: Surgeon administered ACB is not inferior to anesthesiologist administered ACB with respect to pain, opioid consumption, range of motion, patient satisfaction, or short-term functional outcomes. Surgeon administered ACB is an effective alternative to anesthesiologist administered ACB.

Intraoperative Ketamine in Total Knee Arthroplasty Does Not Decrease Pain and Narcotic Consumption: A Prospective Randomized Controlled Trial.

BACKGROUND: Multiple studies have demonstrated that ketamine, a glutamate receptor blocker, may decrease postoperative pain in abdominal and orthopedic surgeries. However, its role with spinal anesthesia and total knee arthroplasty (TKA) remains unknown. The purpose of this study is to determine the efficacy of subanesthetic dosing of ketamine during TKA on postoperative pain and narcotic consumption. METHODS: In this prospective, randomized, double-blinded clinical trial, we enrolled 91 patients undergoing primary TKA with spinal anesthesia in a single institution from 2017 to 2018. Patients were randomized to receive intraoperative ketamine infusion at a rate of 6 mcg/kg/min for 75 minutes or a saline placebo. All patients received spinal anesthesia and otherwise identical surgical approaches, pain management, and rehabilitation protocols. Patient-reported visual analog pain scores were calculated preoperatively, postoperative days (POD) 0-7, and 2 weeks. Narcotic consumption was evaluated on POD 0 and 1. RESULTS: There was no difference in average pain between ketamine and placebo at all time points except for at PODs 1 (45 vs 56, P = .041) and 4 (39 vs 49, P = .040). For least pain experienced, patients administered with ketamine experienced a reduction in pain only at POD 4 (22 vs 35, P = .011). There was no difference in maximum pain cohorts at all time points of the study or in-hospital morphine equivalents between the 2 cohorts. CONCLUSION: As part of multimodal pain management protocol, intraoperative ketamine does not result in a clinically significant improvement in pain and narcotic consumption following TKA.

Routine Patellar Resurfacing During Total Knee Arthroplasty Is Not Cost-Effective in Patients Without Patellar Arthritis.

BACKGROUND: Currently, the decision to resurface the patella is often made irrespective of the presence of patellar arthritis. The purpose of this study is to utilize the existing literature to assess cost-utility of routinely vs selectively resurfacing the patella. METHODS: Prospective randomized studies of patella resurfacing vs non-resurfacing in total knee arthroplasty (TKA) were identified through literature review. Data from these studies represented probabilities of varied outcomes following TKA dependent upon patella resurfacing. Using previously validated utility scores from the McKnee modified Health Utilities Index, endpoint utility values were provided for each potential outcome. RESULTS: Literature review yielded a total of 14 studies with 3,562 patients receiving 3,823 TKAs, of which 1,873 (49.0%) patellae were resurfaced. Persistent postoperative anterior knee pain occurred in 20.9% vs 13.2% (P < .001) and patella reoperation was performed in 3.7% vs 1.6% (P < .001) of unresurfaced and resurfaced patella, respectively. In studies excluding those with arthritic patellae, the incidence of anterior knee pain was equivalent between groups and reoperation decreased to 1.2% vs 0% (P = .06). Patella resurfacing provided marginally improved quality-adjusted life-years (QALY) for both selective and indiscriminate patella resurfacing. When including all studies, the incremental cost per QALY was $3,032. However, when analyzing only those studies with nonarthritic patellae, the incremental cost per QALY to resurface the patella increased to $183,584. CONCLUSION: Patellar resurfacing remains a controversial issue in TKA. Utilizing data from new prospective randomized studies, this analysis finds that routinely resurfacing arthritis-free patellae in TKA are not cost-effective.

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.

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.

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.

Chondroprotection and the prevention of osteoarthritis progression of the knee: a systematic review of treatment agents.

BACKGROUND: Structure-modifying medications or nutraceuticals may be an effective treatment for osteoarthritis. This study identified 12 treatments that may possess chondroprotective properties: oral glucosamine; chondroitin; nonsteroidal anti-inflammatory drugs (NSAIDs); polyunsaturated fatty acids; S-adenosylmethionine; avocado and soybean unsaponifiable fractions; methylsulfonylmethane; vitamins C, D, and E; intra-articular injections of hyaluronic acid; and platelet-rich plasma (PRP). PURPOSE: To perform a systematic review of randomized controlled trials for the effectiveness of each agent in preserving articular cartilage of the knee and delaying the progression of osteoarthritis. STUDY DESIGN: Systematic review; Level of evidence, 2. METHODS: A literature search was performed using PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. Searches were performed using "treatment," "osteoarthritis," and "knee" as keywords. Selection criteria included randomized controlled trials of ≥12 months, with a placebo control, measuring radiographic changes in joint space width, cartilage volume, or radiographic progression of osteoarthritis. The primary outcome was changes in joint integrity measures. RESULTS: A total of 3514 studies were identified from the initial search, 13 of which met inclusion criteria. Treatment with chondroitin sulfate showed a significant reduction in cartilage loss in 3 of 4 studies identified compared with placebo. Two of 3 trials identified for glucosamine also reported significant structural effects relative to placebo. Intra-articular hyaluronic acid was effective in lowering the rate of cartilage loss in only 1 of 3 studies identified versus placebo. Of the 6 studies identified for NSAIDs, vitamin E, and vitamin D, none showed any structural effect compared with placebo. No studies were found that met the inclusion criteria for polyunsaturated fatty acids, S-adenosylmethionine, avocado and soybean unsaponifiable fractions, methylsulfonylmethane, vitamin C, or PRP. CONCLUSION: For patients with or at risk for osteoarthritis, the use of glucosamine and chondroitin sulfate may serve as a nonoperative means to protect joint cartilage and delay osteoarthritis progression. Hyaluronic acid injections showed variable efficacy, while NSAIDs and vitamins E and D showed no effect on osteoarthritis progression. The other agents evaluated had no evidence in the literature to support or refute their use for chondroprotection.

Performance characteristics of broth-only cultures after revision total joint arthroplasty.

BACKGROUND: Surgeons frequently obtain intraoperative cultures at the time of revision total joint arthroplasty. The use of broth or liquid medium before applying the sample to the agar medium may be associated with contamination and false-positive cultures; however, the degree to which this is the case is not known. QUESTIONS/PURPOSES: We (1) calculated the performance characteristics of broth-only cultures (sensitivity, specificity, positive predictive value, and negative predictive value) and (2) characterized the organisms identified in broth to determine whether a specific organism showed increased proclivity for true-positive periprosthetic joint infection (PJI). METHODS: A single-institution retrospective chart review was performed on 257 revision total joint arthroplasties from 2009 through 2010. One hundred ninety (74%) had cultures for review. All culture results, as well as treatment, if any, were documented and patients were followed for a minimum of 1 year for evidence of PJI. Cultures were measured as either positive from the broth only or broth negative. The true diagnosis of infection was determined by the Musculoskeletal Infection Society criteria during the preoperative workup or postoperatively at 1 year for purposes of calculating the performance characteristics of the broth-only culture. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value were 19%, 88%, 13%, and 92%, respectively. The most common organism identified was coagulase-negative Staphylococcus (16 of 24 cases, 67%). Coagulase-negative Staphylococcus was present in all three true-positive cases; however, it was also found in 13 of the false-positive cases. CONCLUSIONS: The broth-only positive cultures showed poor sensitivity and positive predictive value but good specificity and negative predictive value. The good specificity indicates that it can help to rule in the presence of PJI; however, the poor sensitivity makes broth-only culture an unreliable screening test. We recommend that broth-only culture results be carefully scrutinized and decisions on the diagnosis and treatment of infection should be based specifically on the Musculoskeletal Infection Society criteria. LEVEL OF EVIDENCE: Level IV, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Is it time to include vancomycin for routine perioperative antibiotic prophylaxis in total joint arthroplasty patients?

In an effort to reduce methicillin-resistant Staphylococcus aureus (MRSA) and overall periprosthetic joint infections (PJI), we switched the perioperative prophylactic antibiotic during total knee arthroplasty and total hip arthroplasty from cefazolin to vancomycin in June 2008. We retrospectively reviewed the total and MRSA PJI in 5036 primary total joint arthroplasties, as well as the cure rate of PJI from January 2006 to June 2008 (Ancef Period) and June 2008 to December 2010 (Vanco Period). With vancomycin, total PJI was significantly reduced (1.0%-0.5%) and MRSA PJI (0.23%-0.07%). Periprosthetic joint infections that occurred were more successfully treated with irrigation and debridement only, not requiring spacer (76.9% vs 22.2%). The use of vancomycin as the perioperative prophylactic antibiotic for primary total joint arthroplasties appeared to be effective in decreasing the rate of PJI and may result, when they occur, in infections with less virulent organisms.

Platelet-rich plasma does not reduce blood loss or pain or improve range of motion after TKA.

BACKGROUND: Numerous reports suggest the application of platelet-rich plasma (PRP) during TKA may decrease postoperative bleeding. Because excessive bleeding can increase postoperative pain and inflammation, use of PRP also reportedly decreases the need for narcotics and increases speed of recovery after TKA. Because previous investigations of PRP and TKA reflect a weak level of medical evidence, we sought to confirm these findings. QUESTIONS/PURPOSES: We asked whether an intraoperative application of PRP gel to the deep wound reduced postoperative bleeding after TKA. METHODS: We retrospectively reviewed the charts of all 134 patients who received an intraoperative application of PRP during TKA from November 2009 to April 2010 and all 139 patients undergoing TKA who did not receive PRP between September 2009 to November 2009. Patients' charts were reviewed to identify detailed data, including hemoglobin level, ROM, postoperative narcotic use, and length of hospital stay. Blood loss was determined by the hemoglobin drop on postoperative Day 2. RESULTS: The blood loss between study groups was similar (3.6 g/dL [study] versus 3.8 g/dL [controls]). Differences in passive ROM (88° versus 88°), narcotic requirement (27 versus 32 morphine equivalent), and length of stay (2.4 versus 2.6 days) were also similar. CONCLUSION: We found no clinically important differences in patients who received an intraoperative application of PRP compared with patients who did not receive PRP and therefore could not confirm the findings of previous studies.

Effects of a preoperative femoral nerve block on pain management and rehabilitation after total knee arthroplasty.

The objective of this prospective, randomized, double-blind study was to determine if preoperative administration of a femoral nerve block reduces the amount of morphine needed for postoperative analgesia after total knee arthroplasty (TKA). Forty-two patients undergoing TKA were randomly assigned to receive either a femoral nerve block (0.50% bupivacaine hydrochloride with epinephrine 1:200,000) or matching placebo. Results showed postoperative morphine use was significantly lower in patients who received the nerve block (25.5 vs 37.5 mg, P = .016); however, the 2 groups had similar pain scores and rehabilitative outcomes. In general, a preoperative femoral nerve block is a safe and effective adjunct for decreasing morphine use for post-TKA analgesia.