The Fragility of Statistically Significant Findings From Randomized Controlled Trials in Hip and Knee Arthroplasty

BackgroundThe Fragility Index (FI) is a method for evaluating the robustness of statistically significant findings from randomized controlled trials (RCTs) beyond the P value in trials with dichotomous outcomes. The FI is defined as the number of patients in one arm of a trial that would have to have a different outcome to change the results of the trial from statistically significant to nonsignificant. This review assessed the FI in arthroplasty RCTs.MethodsA systematic search was conducted in MEDLINE, Embase, and Web of Science for RCTs related to primary total joint arthroplasty (TJA) from 2010 to 2020. Trials with a statistically significant dichotomous primary outcome were included. The FI was calculated using Fisher’s exact test to determine how many events would need to be reversed to change a study from statistically significant to nonsignificant.ResultsA total of 34 RCTs were included. The median sample size was 103 patients (range 24-791). The median FI was 1 (range 0-45), meaning that reversing the outcome of just one patient in either treatment group of each trial would change it from a significant to a nonsignificant result.ConclusionHip and knee arthroplasty RCTs with statistically significant dichotomous outcomes in TJA are fragile. The median FI in TJA is lower than the FI in any of the other previously reported orthopedic subspecialties. Fragility is another reason to be cautious when conducting or interpreting small trials, and to continue to strive toward large trials to answer important questions in TJA.Level of EvidenceLevel I.     

A Prospective Randomized Controlled Trial Comparing Medial-Pivot versus Posterior-Stabilized Total Knee Arthroplasty

BackgroundThe medial-pivot (MP) design for total knee arthroplasty (TKA) aims to restore more natural “ball-and-socket” knee kinematics compared to the traditional posterior-stabilized (PS) implants for TKA. The objective of this study is to determine if there was any difference in functional outcomes between patients undergoing MP-TKA vs PS-TKA.MethodsThis prospective randomized controlled trial consisted of 43 patients undergoing MP-TKA vs 45 patients receiving a single-radius PS-TKA design. The primary outcome was postoperative range of motion (ROM). Secondary outcomes included the Western Ontario and McMaster Universities Arthritis Index, Oxford Knee Score, Knee Society Score (KSS), and radiological outcomes. All study patients were followed-up for 2 years after surgery.ResultsPatients undergoing MP-TKA had comparable ROM at 1 year (114.6° ± 16.3° vs 111.3° ± 17.8° respectively, P = .88) and 2 years after surgery (114.9° ± 15.5° vs 114.9° ± 16.4° respectively, P = .92) compared to PS-TKA. There were also no differences in Western Ontario and McMaster Universities Arthritis Index (26.8 ± 19.84 vs 22.0 ± 12.03 respectively, P = .14), Oxford Knee Score (42.7 ± 8.1 vs 42.3 ± 6.7 respectively, P = .18), KSS clinical scores (82.9 ± 16.96 vs 81.42 ± 10.45 respectively, P = .12) and KSS functional scores (76.2 ± 18.81 vs 73.93 ± 8.53 respectively, P = .62) at 2-year follow-up. There was no difference in postoperative limb alignment or complications.ConclusionThis study demonstrated excellent results in both the single-radius PS-TKA design and MP-TKA design. No differences were identified at 2-year follow-up with respect to postoperative ROM and patient-reported outcome measures.     

Randomized Controlled Trial of Sensor-Guided Knee Balancing Compared to Standard Balancing Technique in Total Knee Arthroplasty

BackgroundDespite advances in total knee arthroplasty (TKA) technology, up to 1 in 5 patients remain dissatisfied. This study sought to evaluate if sensor-guided knee balancing improves postoperative clinical outcomes and patient satisfaction compared to a conventional gap balancing technique.MethodsWe undertook a prospective double-blind randomized controlled trial of patients presenting for elective primary TKA to determine a difference in TKA soft tissue balance between a standard gap balancing (tensiometer) approach compared to augmenting the balance using a sensor-guided device. The sensor-guided experimental group had adjustments made to achieve a balanced knee to within 15 pounds of intercompartmental pressure difference. Secondary outcomes included differences in clinical outcome scores at 6 months and 1 year postoperative, including the Oxford Knee Score and Knee Society Score and patient satisfaction.ResultsThe sample comprised of 152 patients, 76 controls and 76 experimental sensor-guided cases. Within the control group, 36% (27/76) of knees were unbalanced based on an average coronal plane intercompartmental difference >15 pounds, compared to only 5.3% (4/76) within the experimental group (P < .0001). There were no significant differences in 1-year postoperative flexion, Knee Society Score, or Oxford scores. Overall, TKA patient satisfaction at 1 year was comparable, with 81% of controls and experimental cases reporting they were very satisfied (P = .992).ConclusionDespite the use of the sensor-guided knee balancer device to provide additional quantitative feedback in the evaluation of the soft tissue envelope during TKA, we were unable to demonstrate improved clinical outcomes or patient satisfaction compared to our conventional gap balancing technique.     

Social Determinants of Health and Patient-Reported Outcomes Following Total Hip and Knee Arthroplasty in Veterans

BackgroundSocial determinants of health (SDOH) are the conditions in which people are born, grow, live, work, and age. They are associated with disparities in outcomes following total joint arthroplasty (TJA). These disparities occur even in equal-access healthcare systems such as the Veterans Health Administration (VHA). Our goal was to determine whether SDOH affect patient-reported outcome measures (PROMs) following TJA in VHA patients.MethodsPatients scheduled to undergo total hip or knee arthroplasty at VHA Hospitals in Minneapolis, MN, Palo Alto, CA, and San Francisco, CA, prospectively completed PROMs before and 1 year after surgery. PROMs included the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, and their Joint Replacement subscores. SDOH included race, ethnicity, marital status, education, and employment status. The level of poverty in each patient’s neighborhood was determined. Medical comorbidities were recorded. Univariate and multivariate analyses were performed to determine whether SDOH were significantly associated with PROM improvement after surgery.ResultsOn multivariate analysis, black race was significantly negatively correlated with knee PROM improvement and Hispanic ethnicity was significantly negatively correlated with hip PROM improvement compared to whites. Higher baseline PROM scores and lower age were significantly associated with lower PROM improvement. Significant associations were also found based on education, gender, comorbidities, and neighborhood poverty.ConclusionMinority VHA patients have lower improvement in PROM scores after TJA than white patients. Further research is required to identify the reasons for these disparities and to design interventions to reduce them.     

Patellar Denervation in Total Knee Arthroplasty Without Patellar Resurfacing and Postoperative Anterior Knee Pain: A Meta-Analysis of Randomized Controlled Trials

The aim of this meta-analysis was to investigate whether patellar denervation with electrocautery (PD) after total knee arthroplasty (TKA) could reduce the postoperative anterior knee pain (AKP). Five randomized controlled trials (RCTs) with 572 patients and 657 knees were eligible for this meta-analysis. Our results showed that PD was associated with less AKP, lower visual analogue scale (VAS), higher patellar scores and better knee function compared with no patellar denervation (NPD). Complications did not differ significantly between the two groups. The existing evidence indicates that PD may be a better approach, as it improves both anterior knee pain and knee function after TKA. Future multi-center randomized controlled studies with large sample sizes are required to verify the current findings.     

A Randomized Controlled Trial of Intraarticular Ropivacaine for Pain Management Immediately Following Total Knee Arthroplasty

Total knee arthroplasty (TKA) is a commonly performed procedure for the treatment of end-stage arthritis of the knee. Pain control following TKA is difficult to manage in some patients. We examined the use of a postoperative intraarticular injection of 100 mL of 0.2% (200 mg) ropivacaine in a double-blind, prospective, placebo-controlled pilot study to evaluate its use as a pain control modality. All patients received general anesthesia. Postoperatively, patients were placed on intravenous patient-controlled analgesia with morphine. The ropivacaine group showed an early trend in lower visual analog scale (VAS) scores when compared with the placebo group. Patients receiving ropivacaine used a similar amount of narcotics compared with the placebo group. Intraarticular ropivacaine used for pain control after TKA demonstrated no statistically significant difference in lowering VAS scores or narcotic usage; therefore, intraarticular ropivacaine as a single modality is not recommended for effective pain management.     

Characterization and Potential Relevance of Randomized Controlled Trial Patient Populations in Total Joint Arthroplasty in the United States: A Systematic Review

BackgroundA substantial number of randomized controlled trial (RCT) studies in total joint arthroplasty (TJA) are published each year in the United States (US). However, it is unknown how closely the demographic and clinical characteristics of these cohorts resemble that of the US patient population undergoing TJA. Thus, the purpose of this systematic review was to evaluate the patient characteristics of published RCTs in TJA in the US and to compare these characteristics against patient cohorts from national patient databases.MethodsRCT studies regarding primary TJA conducted in the US were selected. Key patient demographics were aggregated and compared against demographics characteristics of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality National Inpatient Sample (NIS) and American College of Surgeons National Surgical Quality Improvement Program patient cohorts.ResultsOne hundred and fifty-three RCTs fulfilled the inclusion criteria and were included. The total number of patients in the 153 RCTs was 24,135 patients. The average age of patients in the TJA RCT cohort was 65 years (53-80) while the NIS cohort was 67 years (18-90) (d = 0.21, effect size = small). The average body mass index of the TJA RCT cohort was 30.8 (18.2-37.6) while the National Surgical Quality Improvement Program cohort was 31.9 (14.1-59.6) (d = 0.18, effect size = small). For TJA, effect sizes for age, body mass index BMI, sex, ethnicity, smoking, and diabetes were all small or very small.ConclusionOverall, the US RCT patient cohort for TJA does not differ substantially from the general patient population undergoing TJA in the United States. Differences in demographic and clinical characteristics between the TJA RCT cohort and database cohorts ranged from minimal to small, suggesting that these differences are unlikely to impact clinical outcomes.     

A Meta-Analysis of Patellar Replacement in Total Knee Arthroplasty for Patients With Knee Osteoarthritis

Background

This meta-analysis (MA) aims at comparing the clinical outcomes of resurfacing and nonresurfacing the patella in patients undergoing total knee arthroplasty in the treatment of knee osteoarthritis.

Significant Analgesic Benefits of Perioperative Duloxetine in Patients Who Have Depressive Symptoms Undergoing Total Hip Arthroplasty: A Randomized Controlled Trial

BackgroundMajor symptoms of depression are commonly observed in patients requiring total hip arthroplasty (THA), and this is associated with increased pain scores and opioid consumption. We aimed to investigate the analgesic effect of duloxetine in these high-risk patients.MethodsAmong 263 patients scheduled for primary unilateral THA, 67 patients who scored at least 8 on the 17-item Hamilton Depression Scale (HAMD) were enrolled in this study. Patients were randomized to the duloxetine group (60 mg daily, from the day of surgery to postoperative day 6) or the placebo group. The postoperative visual analog scale (VAS) score during walking, the VAS score during hip flexion, and resting VAS score was measured. Postoperative morphine consumption, hip range of motion (ROM), Harris hip score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function, postoperative length of stay (LOS), and adverse events were recorded.ResultsThe duloxetine group had significantly lower VAS scores during walking and hip flexion from postoperative day 3 to week 3 than the placebo group. With regard to the resting VAS score, duloxetine showed a better analgesic effect from postoperative day 3 to week 2 than placebo. Patients in the duloxetine group had less consumption of morphine. The duloxetine group exhibited better hip function scores, including ROM, HHS, and WOMAC function scores than the placebo group. No significant difference was observed in LOS or adverse events between groups.ConclusionPerioperative short-term duloxetine provides advantages in decreasing pain, reducing morphine consumption, and increasing hip function in THA patients who have depressive symptoms.     

Randomized Controlled Trial of Radiographic and Patient-Assessed Outcomes Following Fixed Versus Rotating Platform Total Knee Arthroplasty

This prospectively blinded randomized controlled study evaluated the difference in the functional and radiological outcomes in patients who received a press-fit condylar Sigma cemented cruciate-substituting total knee arthroplasty with either a rotating platform (RP) or a fixed bearing (FB). There were 51 joints in 49 patients: 24 joints in the RP group (mean follow-up, 43 months) and 27 joints in the FB group (mean follow-up, 40 months). At baseline, there was no significant difference in age, body mass index, preoperative diagnosis, Charnley class, range of motion, clinical and functional scores, between the RP and FB groups. At mid-term follow up both the RP and FB give equivalent results, but patients with the RP tended to have a higher activity level score.     

Systematic Review and Meta-Analysis of Intrawound Vancomycin in Total Hip and Total Knee Arthroplasty: A Continued Call for a Prospective Randomized Trial

BackgroundPeriprosthetic joint injection (PJI) is a rare, but life-altering complication of total joint arthroplasty (TJA). Though intrawound vancomycin powder (IVP) has been studied in other orthopedic subspecialties, its efficacy and safety in TJA has not been established.MethodsPubMed and MEDLINE databases were used to identify studies utilizing IVP in primary and revision total hip (THA) and knee arthroplasty (TKA). Postoperative PJI data were pooled using random effect models with results reported as odds ratios (ORs) and 95% confidence intervals (CIs). Studies were weighted by the inverse variance of their effect estimates.ResultsOverall, 16 of the 1871 studies identified were pooled for final analysis, yielding 33,731 patients totally. Of these, 17 164 received IVP. In aggregate, patients who received IVP had a decreased rate of PJI (OR 0.46, P < .05). Separately, TKA and THA patients who received IVP had lower rates of PJI (OR 0.41, P < .05 and OR 0.45, P < .05, respectively). Aggregate analysis of primary TKA and THA patients also revealed a decreased PJI rate (OR 0.44, P < .05). Pooled revision TKA and THA patients had a similar decrease in PJI rates (OR 0.30, P < .05). Although no publication bias was appreciated, these findings are limited by the low-quality evidence available.ConclusionWhile IVP may reduce the risk of PJI in primary and revision TJA, its widespread use cannot be recommended until higher-quality data, such as that obtained from randomized control trials, are available. This study underscores the continued need for more rigorous studies before general adoption of this practice by arthroplasty surgeons.     

Repeat Doses of Dexamethasone up to 48 Hours Further Reduce Pain and Inflammation After Total Hip Arthroplasty: A Randomized Controlled Trial

BackgroundThe optimal dose regimen of dexamethasone in total hip arthroplasty (THA) is unclear. This study was conducted to compare the effects among 1-dose, 2-dose, and 3-dose dexamethasone in THA.MethodsOne hundred fifty patients were randomized to receive a single preoperative dose of 10-mg dexamethasone (group A, 50 patients), or another dose of 10-mg dexamethasone 24 hours later (group B, 50 patients), or another 2 doses of 10-mg dexamethasone 24 and 48 hours later (group C, 50 patients). The primary outcome was postoperative pain level. The use of analgesic and antiemetic rescue; incidence of postoperative nausea and vomiting; C-reactive protein and interleukin-6 levels; range of motion; and complications were also compared.ResultsThe dynamic pain scores were lower for groups B and C compared to group A on postoperative days 2 and 3. Such difference was also detected between groups B and C on postoperative day 3. C-reactive protein and interleukin-6 levels were lower in groups B and C than in group A at 48 and 72 hours postoperatively. Such difference was also observed between groups B and C at 72 hours postoperatively. Patients in groups B and C had reduced rescue analgesic use, and improved range of motion compared to patients in group A. There were no differences among 3 groups regarding the rescue antiemetic use, postoperative nausea and vomiting occurrence, and complications.ConclusionAdditional administrations of dexamethasone after THA could provide sustained pain relief and inflammatory control. Besides, the 3-dose regimen was more effective than the 2-dose regimen in terms of the analgesic and anti-inflammatory effects.Level of EvidenceI     

Total Knee Arthroplasty Using Bicruciate-Stabilized or Posterior-Stabilized Knee Implants Provided Comparable Outcomes at 2 Years: A Prospective,Multicenter, Randomized,Controlled, Clinical Trial of Patient Outcomes

Background

The bicruciate-stabilized (BCS) knee arthroplasty was developed to replicate normal knee kinematics. We examined the hypothesis that patients with osteoarthritis requiring total knee arthroplasty (TKA) will have better functional outcome and satisfaction with the BCS implant compared with an established posterior cruciate-stabilized implant.

Contemporary Total Hip and Total Knee Arthroplasty Results in Patients with Hemochromatosis

BackgroundHemochromatosis can result in metabolic bone pathology (due to excessive iron absorption) and degenerative joint disease, leading to total joint arthroplasties. The aim of this study is to analyze the survivorship, complications, radiographic results, and clinical outcomes of patients with hemochromatosis who received either a total hip arthroplasty (THA) or a total knee arthroplasty (TKA).MethodsWe identified 34 lower extremity arthroplasties in 29 patients with hemochromatosis performed between 2000 and 2016. There were 17 primary THAs in 15 patients and 17 primary TKAs in 14 patients. Mean age at arthroplasty was 63 years with 76% being male. The mean body mass index was 28 kg/m². Mean follow-up was 5 years.ResultsThe survivorship free from any revision for THAs was 94% at 10 years. One patient was revised for aseptic loosening of the femoral stem at 6 months. In THA patients, no infections, no other complications, and no radiographic evidence of aseptic loosening were identified. Harris Hip Scores improved from a mean of 55 preoperatively to 94 postoperatively (P < .001). The survivorship free from any revision for TKAs was 100% at 10 years. Two patients (12%) developed acquired idiopathic stiffness postoperatively; no infections were identified. There was no radiographic evidence of aseptic loosening in any TKA. Knee Society Scores improved from a mean of 61 preoperatively to 94 postoperatively (P < .001).ConclusionThis study found excellent survivorship, significant improvements in clinical outcomes, and a very low complication profile for both THA and TKA in patients with hemochromatosis.     

Periarticular Injection of Liposomal Bupivacaine Offers No Benefit Over Standard Bupivacaine in Total Knee Arthroplasty: A Prospective,Randomized, Controlled Trial

Background

Periarticular injection of liposomal bupivacaine has been adopted as part of multimodal pain management after total knee arthroplasty (TKA).

Multimodal Nutritional Management in Primary Total Knee Arthroplasty: A Randomized Controlled Trial

Background

This study aims at evaluating the effectiveness of a new multimodal nutritional management (MNM) on albumin (ALB) transfusion, the incidence of electrolyte disorders, blood loss, perioperative levels of ALB and electrolyte, length of hospital stay (LOH), and complications in patients following total knee arthroplasty without tourniquet.

The Fragility of Tourniquet Use in Total Knee Arthroplasty: A Systematic Review of Randomized Controlled Trials

BackgroundPhysicians utilize P-values to interpret clinical trial data and guide patient-care decisions. Fragility analysis assesses the stability of statistical findings in relation to outcome event reversals. This study assessed the statistical fragility of recent randomized controlled trials (RCTs) investigating tourniquet use in total knee arthroplasty (TKA).MethodsWe queried PubMed, EMBASE, and MEDLINE for RCTs comparing outcomes in TKA based on tourniquet use. Fragility index (FI) and reverse fragility index (reverse FI) were calculated – for significant and nonsignificant outcomes, respectively – as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) was calculated by dividing the FI or reverse FI by the sample size. Median overall FI and FQ were calculated for all included outcomes, and sub-analyses were performed by reported significance. The literature search yielded 23 studies reporting 91 total dichotomous outcomes.ResultsOverall median FI was 4 with an interquartile range (IQR) of 3 to 6. Overall median FQ was 0.0476 (IQR 0.0291 to 0.0867). A total of 11 outcomes were statistically significant with a median FI and FQ of 2 (IQR 1.5 to 5) and 0.0200 (IQR 0.0148 to 0.0484), respectively. There were 80 outcomes that were nonsignificant with a median reverse FI of 4 (IQR 3 to 6). Loss to follow-up was greater than the median FI in 17.6% of outcomes.ConclusionAltering a small number of outcomes is often sufficient to reverse findings in RCTs evaluating tourniquet use in TKA. We recommend including fragility analyses to increase reliability in the interpretation of study conclusions.     

Relationships Between Preoperative Mental Health and Improvements in Patient-Reported Outcomes After Total Hip and Knee Arthroplasty

BackgroundPoor preoperative mental health has been associated with worse outcomes after total hip (THA) and total knee arthroplasty (TKA). To fully understand these relationships, we assessed post-THA and post-TKA improvements in patient-reported mental and joint health by preoperative mental health groups.MethodsElective cases (367 THA, 462 TKA) were subgrouped by low (<25th percentile), middle (25th-74th), and high (≥75th) preoperative mental health, using Veterans RAND 12-Item Health Survey Mental Component Summary (MCS) scores. In each subgroup, we assessed the relationship between preoperative MCS and 1-year postoperative change in mental and joint health. Pairwise comparisons and multivariable regression models were applied for THA and TKA separately.ResultsMedian postoperative mental health change was +14.0 points for the low-MCS THA group, +11.1 low-TKA, +2.0 middle-THA and TKA, −4.0 high-THA, and −4.9 high-TKA (between-group differences P < .001). All MCS groups had improved median joint health scores, without significant between-group differences. Preoperative mental health was negatively associated with mental health improvements in all groups (B = −0.94 - −0.68, P < .001-P = .01) but with improvements in joint health only in the low-THA group (B = −0.74, P = .02). Improvements in mental and joint health were positively associated for low and middle (B = 0.61-0.87, P < .001), but not for high-MCS groups, with this relationship differing for the low versus high group.ConclusionPatients who have low preoperative mental health experienced greater postoperative mental health improvement and similar joint health improvement compared to patients who have high preoperative mental health. Findings can guide subgroup-targeted surgical decision-making and preoperative counseling.     

Substantial Preoperative Work Is Unaccounted for in Total Hip and Knee Arthroplasty

BackgroundThe Centers for Medicare and Medicaid Services has recently designated the codes for total hip and knee arthroplasty as misvalued and has asked the Relative Value Scale Update Committee (RUC) to review the work required to perform these procedures. Although other studies have reported time spent on perioperative and postoperative care, time spent on coordinating and performing preoperative care is not included in current RUC methodology and has yet to be addressed in literature.MethodsWe prospectively tracked a consecutive series of 438 primary total hip arthroplasty and total knee arthroplasty patients by one of the 5 surgeons over a 3-month period. Each clinical staff member tracked the amount of time to perform each preoperative care task from the last clinic visit until day of surgery. Data were analyzed separately between providers and ancillary medical staff.ResultsAlthough the current RUC review includes 40 minutes of preservice time on the day of surgery, surgeons spent an average of an additional 43.2 minutes while physician assistants and nurse practitioners spent an additional 97.9 minutes per patient on preoperative care prior to that time. Ancillary medical staff spent a mean of 110.2 minutes per patient. The most common tasks include preoperative phone calls, templating and surgical planning, and preoperative patient education classes.ConclusionSurgeons and advanced practice providers spend nearly 2 hours per arthroplasty patient on preoperative care not accounted for in current RUC methodology. As readmissions, hospital stay, and complication rates continue to decline, Centers for Medicare and Medicaid Services should consider the substantial work required during the preoperative phase to allow for these improved outcomes.