Preoperative Pain and Function: Profiles of Patients Selected for Total Knee Arthroplasty

Linking Intra-Articular Inflammatory Biomarkers with Peripheral and Central Sensitization in Late-Stage Knee Osteoarthritis Pain: A Pilot Study

Background/Objectives: To investigate if intra-articular biomarkers relate to peripheral and central sensitization in patients with late-stage knee osteoarthritis (KOA). Methods: A total of 17 (6M, 11F) patients (aged 69 ± 10 years) were assessed for peripheral (pressure pain thresholds (PPT)) and central (temporal summation (TS) and conditioned pain modulation (CPM)) sensitization the day before total knee arthroplasty. Synovial fluid was collected during surgery and assayed for IL-6, IL-8, IL-10, TNF-α, CXCL-10, BDNF, NGF, CCL2, CCL5, VEGF, IL-1RI, MMP-1, MMP-7, IL-1β, and CXCL-9. Associations of biomarkers and their combinations reflecting chronic (CXCL-9) and acute ((CCL2×CXCL-10)/IL-10)) inflammation, cartilage degeneration (MMP-1×MMP-7), and neurotrophy (NGF×BDNF) with PPT, TS, and CPM were analyzed by bivariate correlations and by multiple linear regression analyses corrected for BMI, sex, and age. Results: The medial joint line and the superior medial joint region showed the lowest PPT. Higher acute inflammation related significantly to worse pressure tenderness at the superior medial joint region (R2 = 0.642; p = 0.010). Cartilage degeneration and chronic inflammation were associated with both absolute (R2 = 0.827; p = 0.001) and relative CPM (R2 = 0.882; p < 0.001). Acute inflammation and neurotrophy were related to relative TS at the m. tibialis anterior (R2 = 0.728; p = 0.02). Conclusions: This study demonstrates that increased levels of intra-articular biomarkers of acute inflammation are related to peripheral sensitization and that biomarkers of cartilage degeneration and chronic inflammation are associated with central sensitization. These results may be a stepping-stone toward a better understanding of the working mechanism of peripheral and central sensitization in KOA pain and the development of more targeted therapeutic interventions.

Head-to-head comparison of appropriate use criteria for knee arthroplasty: A multicenter cohort study

Objective

To determine, in a head-to-head comparison, which of two RAND-based knee replacement appropriateness criteria is optimal based on comparison to an externally validated method of judging good versus poor outcome.

Design

Longitudinal data from the Osteoarthritis Initiative (OAI) and the Multicenter Osteoarthritis Study (MOST) were combined to produce a dataset of 922 persons with knee arthroplasty, 602 of which had adequate data for RAND classification and had their surgery within one year prior to a study visit. Data were used to determine appropriateness classification (i.e., Appropriate, Inconclusive, Rarely Appropriate) using modified versions of the first-generation and second-generation Escobar system. Growth curve analyses and multivariable regression were used to compare the two systems.

Results

Neither system associated with the gold standard measure of good versus poor outcome. Distributions of appropriateness categories for the second-generation system were inconsistent with current evidence for knee arthroplasty outcome. For example, 16% of participants were classified as Appropriate and 64% as Rarely Appropriate for pain outcome. Distributions for the first-generation system aligned with current evidence.

Conclusion

The first-generation modified version of the Escobar appropriateness system is superior to the newer version but neither version associated with our gold standard growth curve analyses. Both systems only differentiate between patient classification groups preoperatively and up to ten months following surgery. Reliance on appropriateness criteria to inform long-term outcome is not warranted.

Radiofrequency ablation prior to total knee arthroplasty does not improve post-surgical pain or recovery: a double-blinded, multi-center, randomized clinical trial

Background

Radiofrequency ablation (RFA) targeting the genicular nerves is an effective treatment for knee pain due to osteoarthritis. The aim of this study was to determine the effects of two RFA interventions delivered preoperatively on early postoperative pain management and subjective outcomes after total knee arthroplasty (TKA).

Methods

One hundred forty-three participants were enrolled in this double blinded, sham-controlled prospective randomized trial. Participants assigned at random to traditional RFA (t-RFA) (n=50), cooled RFA (c-RFA) (n=49), or sham (n=44) procedures prior to TKA. Outcomes were recorded at postoperative day 3, week 1, week 2, week 12, month 6, and month 12 following TKA. Primary outcomes included hospital length of stay (LOS), opioid consumption (reported as MEQ, or daily morphine equivalents), time to narcotic cessation (reported in days), and pain scores (reported as NRS, or Numeric Rating Scale). Secondary outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) measures. All side effects and complications were reported. Participants were followed for a year to detect any unexpected side effects.

Results

Compared with sham controls, t-RFA and c-RFA did not affect inpatient LOS, pain scores, or opioid consumption. There were no reductions in time to opioid cessation, pain scores, or WOMAC scores at any time point post-TKA.

Conclusions

RFA of the genicular nerves prior to TKA did not affect opioid use or time to cessation, pain, or WOMAC scores, following TKA. Current techniques of t-RFA and c-RFA of these specific geniculate nerves preoperatively are not indicated as routine interventions to improve short-term surgical recovery after TKA.

Trial Registration

The trial was registered on ClinicalTrials.gov (NCT02925442).

The Prevalence and Predictors of Patient Dissatisfaction 5-years Following Primary Total Knee Arthroplasty

BACKGROUND

Previous studies have evaluated patient dissatisfaction after total knee arthroplasty (TKA) at 1 year, but there is no data about the prevalence of dissatisfaction among TKA patients after prolonged follow-up. The purpose of this study is to determine patient dissatisfaction 5-years after TKA and to identify patient factors predictive of dissatisfaction.

METHODS

Demographic and clinical data on 4402 patients undergoing primary unilateral TKA between 2012 and 2015 were collected prospectively through the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR) comparative effectiveness consortium including diverse community and academic practices distributed across 23 states in the United States. Data collected at 1 year preoperatively and 5 years postoperatively included patient satisfaction (using a 5-point Likert satisfaction scale) and patient-reported outcome measures (PROMs) including the Knee injury and Osteoarthritis Outcome Score (KOOS) and Short-Form health survey (36-item). A univariate analysis of the difference between the satisfied and dissatisfied patients' groups was performed. A multivariate logistic regression model with 95% confidence interval (CI) was used to identify independent predictors of dissatisfaction at 5 years. The regression model was performed after adjusting the following variables: age, gender, body mass index (BMI), Charlson Comorbidity Index (CCI), marital status, smoking, education, and insurance type. The Receiver Operating Characteristic (ROC) analysis was performed with the measurement of area under curve (AUC). Hosmer-Lemeshow goodness of fit test was performed to evaluate the validity of the model.

RESULTS

A total of 12.7% patients (559/4402) reported dissatisfaction 5-years after TKA. Increased BMI, higher CCI, higher Oswestry disability index, and increased number of other painful lower extremities (LE) joints were significantly associated with dissatisfaction. Higher rates of dissatisfaction were present in young patients, patients with less education, and non-White patients. Patient dissatisfaction was significantly associated with poor preoperative and 5-year postoperative PROMs scores and less score improvement from baseline to 5 years (P < .001). The multivariate regression analysis showed that an increased number of other painful LE joints (OR = 1.81; 95% CI (1.14-2.88) (P = .01), increased Oswestry back disability index (OR = 1.40; 95% CI (1.07-1.82) (P = .01), non-White patients (OR = 1.74; 95% CI (1.26-2.40) (P = .001), and minimal preoperative functional disability with KOOS function in daily living (ADL) score ≥70 (OR = 0.64; 95% CI (0.43-0.95) (P = .02) were independent predictive factors for dissatisfaction at 5 years.

CONCLUSION

A total of 12.7% patients reported dissatisfaction 5-years after TKA. Clinical profiles of the satisfied and dissatisfied patients were captured 5-years after TKA with differences in the preoperative demographic and clinical characteristic variables identified. Risk factors for long-term patient dissatisfaction after TKA have been identified and should be considered during shared decision making while planning for TKA. Surgeons should use these identified risk factors to set realistic expectations for patients at an increased risk for dissatisfaction aiming to optimize their outcomes and increase their long-term satisfaction after TKA.

Continuous Lumbar Plexus Block under the Guidance of the "Shamrock Method" Ultrasound: Analgesic Effects and Hemodynamic Effects after Total Knee Arthroplasty in Elderly Patients

Objective

To explore the effect of continuous lumbar plexus block guided by the “Shamrock method” on postoperative analgesia and hemodynamics in elderly patients after total knee arthroplasty (TKA).

Methods

From January 2020 to December 2020 in our hospital, 98 patients who underwent TKA were selected. Using the random number table method, the patients were divided into two groups: a continuous lumbar plexus block group (group L), with 49 patients, and a continuous femoral nerve block group (group F), with 49 patients. The onset time and maintenance time of motor and sensory nerve blocks in patients were recorded. A visual analogue scale (VAS) was applied to assess the pain severity at 6, 12, 24, and 48 h after the operation. The VAS score (FVAS) was applied to evaluate the pain severity of the patients during 24 and 48 h after the operation and knee joint functional exercise. The levels of hemodynamic indexes such as heart rate, mean arterial pressure, and oxyhemoglobin saturation and the levels of hemorheological indexes such as plasma viscosity, high and low whole blood shear viscosity, fibrinogen, and hematocrit were detected and compared between the two groups immediately after the operation and at 12 h and 48 h after the operation, respectively. The incidence of adverse reactions induced by anesthesia was counted.

Results

The onset time of motor and sensory nerve blocks in group L was lower than that in group F, and the maintenance time was higher than that in group F (P < 0.05). The VAS scores of 6, 12, 24, and 48 h after operation in group L were significantly lower than those in group F (P < 0.05). The FVAS scores of group L at 24 and 48 h after operation were significantly lower than those of group F (P < 0.05). The heart rates of the patients in the two groups were higher at 12 h and 48 h after operation than those immediately after operation (P < 0.05). The heart rates at 12 h and 48 h after operation in group L were lower than those in group F (P < 0.05). The plasma viscosity, high whole blood shear viscosity, and low whole blood shear viscosity in the group L at 12 h and 48 h after operation were lower than those in group F (P < 0.05). There was no significant difference in the incidence of local anesthetic poisoning, nausea, vomiting, urinary retention, pruritus, and other adverse reactions between the two groups (P > 0.05).

Conclusion

The “Shamrock method” ultrasound-guided continuous lumbar plexus block in elderly patients after TKA has good analgesic effect, stable hemodynamics, little influence on hemorheology, and good safety. It is of great value to enhance the surgical effect and promote postoperative rehabilitation.

Cost-effectiveness of duloxetine for knee OA subjects: the role of pain severity

OBJECTIVE

Establish the impact of pain severity on the cost-effectiveness of generic duloxetine for knee osteoarthritis (OA) in the United States.

DESIGN

We used a validated computer simulation of knee OA to compare usual care (UC) - intra-articular injections, opioids, and total knee replacement (TKR) - to UC preceded by duloxetine in those no longer achieving pain relief from non-steroidal anti-inflammatory drugs (NSAIDs). Outcomes included quality-adjusted life years (QALYs), lifetime medical costs, and incremental cost-effectiveness ratios (ICERs). We considered cohorts with mean ages 57-75 years and Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain 25-55 (0-100, 100-worst). We derived inputs from published data. We discounted costs and benefits 3% annually. We conducted sensitivity analyses of duloxetine efficacy, duration of pain relief, toxicity, and costs.

RESULTS

Among younger subjects with severe pain (WOMAC pain = 55), duloxetine led to an additional 9.6 QALYs per 1,000 subjects (ICER = $88,500/QALY). The likelihood of duloxetine being cost-effective at willingness-to-pay (WTP) thresholds of $50,000/QALY and $100,000/QALY was 40% and 54%. Offering duloxetine to older patients with severe pain led to ICERs >$150,000/QALY. Offering duloxetine to subjects with moderate pain (pain = 25) led to ICERs <$50,000/QALY, regardless of age. Among knee OA subjects with severe pain (pain = 55) who are unwilling or unable to undergo TKR, ICERs were <$50,600/QALY, regardless of age.

CONCLUSIONS

Duloxetine is a cost-effective addition to knee OA UC for subjects with moderate pain or those with severe pain unable or unwilling to undergo TKR. Among younger subjects with severe pain, duloxetine is cost-effective at WTP thresholds >$88,500/QALY.

Advanced decision-making using patient-reported outcome measures in total joint replacement

Up to one-third of total joint replacement (TJR) procedures may be performed inappropriately in a subset of patients who remain dissatisfied with their outcomes, stressing the importance of shared decision-making. Patient-reported outcome measures capture physical, emotional, and social aspects of health and wellbeing from the patient's perspective. Powerful computer systems capable of performing highly sophisticated analysis using different types of data, including patient-derived data, such as patient-reported outcomes, may eliminate guess work, generating impactful metrics to better inform the decision-making process. We have created a shared decision-making tool which generates personalized predictions of risks and benefits from TJR based on patient-reported outcomes as well as clinical and demographic data. We present the protocol for a randomized controlled trial designed to assess the impact of this tool on decision quality, level of shared decision-making, and patient and process outcomes. We also discuss current concepts in this field and highlight opportunities leveraging patient-reported data and artificial intelligence for decision support across the care continuum.

Translating clinical and patient-reported data to tailored shared decision reports with predictive analytics for knee and hip arthritis

Introduction

New informatics tools can transform evidence-based information to individualized predictive reports to serve shared decisions in clinic. We developed a web-based system to collect patient-reported outcomes (PROs) and medical risk factors and to compare responses to national registry data. The system generates predicted outcomes for individual patients and a report for use in clinic to support decisions. We present the report development, presentation, and early experience implementing this PRO-based, shared decision report for knee and hip arthritis patients seeking orthopedic evaluation.

Methods

Iterative patient and clinician interviews defined report content and visual display. The web-system supports: (a) collection of PROs and risk data at home or in office, (b) automated statistical processing of responses compared to national data, (c) individualized estimates of likely pain relief and functional gain if surgery is elected, and (d) graphical reports to support shared decisions. The system was implemented at 12 sites with 26 surgeons in an ongoing cluster randomized trial.

Results

Clinicians and patients recommended that pain and function as well as clinical risk factors (e.g., BMI, smoking) be presented to frame the discussion. Color and graphics support patient understanding. To date, 7891 patients completed the assessment before the visit and 56% consented to study participation. Reports were generated for 98% of patients and 68% of patients recalled reviewing the report with their surgeon.

Conclusions

Informatics solutions can generate timely, tailored office reports including PROs and predictive analytics. Patients successfully complete the pre-visit PRO assessments and clinicians and patients value the report to support shared surgical decisions.

Electronic supplementary material

The online version of this article (10.1007/s11136-020-02557-8) contains supplementary material, which is available to authorized users.

Changes of Somatosensory Phenotype in the Course of Disease in Osteoarthritis Patients

To investigate sensory changes, physical function (pF), quality of life (QoL) and pain intensity of patients with osteoarthritis (OA) in the natural course of disease, and patients undergoing total joint replacement therapy (TJR) 31 (20 females, mean age 64.6 ± 10.4 years), patients with OA were investigated with questionnaires and quantitative sensory testing (QST) in the area of referred pain at the thigh at baseline and follow-up 22–49 weeks later; changes were analyzed separately for patients with (n = 13) and without TJR (n = 18). In patients without TJR pain intensity, pF, QoL did not improve, and increased pain sensitivity to cold and a stronger loss of detection were observed. In patients after TJR, however, a reduction in mechanical pain sensitivity and allodynia occurred in accordance with a reduction of pain intensity and improvement of functionality while QoL did not improve. Additionally, an increased sensitivity to heat pain and a more pronounced loss of mechanical detection could be observed in this group. TJR seems to stop peripheral pain input leading to a reduction of pain intensity and central sensitization, but surgery-induced sensory changes such as peripheral sensitization and loss of detection occur. Furthermore, TJR has favorable effects on pain intensity and functionality but not QoL.

Influence of severe knee pain, meniscus surgery and knee arthroplasty on physical ability: an observational study of 114 949 adults in the CONSTANCES cohort

BACKGROUND

The knee is one of the major sites of musculoskeletal pain, yet few large-scale studies have evaluated the impact of knee disorders on physical limitations. Our objective was to describe this impact in a large-scale population study.

METHODS

We included subjects of working age from the CONSTANCES cohort, from its inception. Four groups were distinguished according to their medical history: whether they had knee arthroplasty (KA), meniscus surgery, severe knee pain, or none of these. Outcomes assessed for physical limitations were self-reported limitations in the last 6 months due to health problems, limitation on carrying 5 kg on 10 m and a 3-metre length rapid gait speed test (for participants aged >45). Associations between knee groups and patients' characteristics and physical limitations were analysed using logistic regression. Robust associations were deemed relevant if their ORs were higher than 2 and their p value lower than 0.0001.

RESULTS

Of the 114 949 individuals, 99 052 (86.2%) were in the 'no pain and no surgery' group, 14 740 (12.8%) were in the severe knee pain group, 1019 (0.89%) had meniscus surgery and 138 (0.12%) had KA. Severe knee pain and KA groups showed a similar profile (they were less at work, reported more deterioration in their health and had more limitations).

CONCLUSION

Almost 14% of the sample had knee disorders. Subjects reporting severe knee pain or who had KA reported more important physical limitations then subjects who reported neither severe knee pain nor knee surgery.

Impact of Resilience on Outcomes of Total Knee Arthroplasty

BACKGROUND

Resilience, defined as the ability to bounce back from stress, has been suggested as a predictor of surgical outcomes. The purpose of this study is to examine the relationship between resilience and patient-reported outcomes following primary elective total knee arthroplasty (TKA). We hypothesized that patients exhibiting greater preoperative resilience would report better outcome scores.

METHODS

A prospective cohort of 153 patients (74 male, 79 female) undergoing primary elective TKA completed questionnaires preoperatively and at 3 and 12 months following their index procedure. The validated Brief Resilience Scale was used to evaluate resilience. Hierarchical multiple linear regression was used to analyze the effect of resilience on KOOS-JR (Knee Injury and Osteoarthritis Outcome Score JR) and PROMIS-10 (Patient-Reported Outcomes Measurement Information System) outcome scores.

RESULTS

At 12 months, the change in the coefficient of determination (R²) attributable to preoperative resilience was 0.101 (P < .001) and 0.204 (P < .001) for physical and mental health, respectively. Although there was expected improvement in KOOS-JR scores following TKA, the effect of baseline resilience for this outcome was not significant. When evaluating resilience measured concurrently, there was significant correlation with both 3-month and 12-month KOOS-JR and PROMIS-10 outcome scores.

CONCLUSION

Preoperative resilience is a significant predictor of overall physical and mental health outcomes at both 3 and 12 months. Greater concurrent resilience predicted better scores across all outcomes. These findings suggest that major elective surgery, like other traumatic events, can cause a change in resilience. Although functional improvements after TKA are expected, those patients who exhibit greater resilience at baseline are more likely to report an improved quality of life.

A Comprehensive Review of Stem Cells for Cartilage Regeneration in Osteoarthritis

Osteoarthritis (OA) is an age related joint disease associated with degeneration and loss of articular cartilage. Consequently, OA patients suffer from chronic joint pain and disability. Weight bearing joints and joints that undergo repetitive stress and excessive 'wear and tear' are particularly prone to developing OA. Cartilage has a poor regenerative capacity and current pharmacological agents only provide symptomatic pain relief. OA patients that respond poorly to conventional therapies are ultimately treated with surgical procedures to promote cartilage repair by implantation of artificial joint structures (arthroplasty) or total joint replacement (TJR). In the last two decades, stem cells derived from various tissues with varying differentiation and tissue regeneration potential have been used for the treatment of OA either alone or in combination with natural or synthetic scaffolds to aid cartilage repair. Although stem cells can be differentiated into chondrocytes in vitro or aid cartilage regeneration in vivo, their potential for OA management remains limited as cartilage regenerated by stem cells fails to fully recapitulate the structural and biomechanical properties of the native tissue. Efficient tissue regeneration remains elusive despite the simple design of cartilage, which unlike most other tissues is avascular and aneural, consisting of a single cell type. In this article, we have comprehensively reviewed the types of stem cells that have been proposed or tested for the management of OA, their potential efficacy as well as their limitations. We also touch on the role of biomaterials in cartilage tissue engineering and examine the prospects for their use in cell-based therapies.

Early recovery following lower limb arthroplasty: Qualitative interviews with patients undergoing elective hip and knee replacement surgery. Initial phase in the development of a patient-reported outcome measure

AIMS AND OBJECTIVES

To explore the patients' perspective of surgery and early recovery when undergoing lower limb (hip or knee) arthroplasty.

BACKGROUND

Lower limb arthroplasty is a commonly performed procedure for symptomatic arthritis, which has not responded to conservative medical treatment. Each patient's perspective of the surgical process and early recovery period impacts on their quality of life.

DESIGN

Open, semistructured qualitative interviews were used to allow for a deeper understanding of the patient perspective when undergoing a hip or knee arthroplasty.

METHODS

Following ethical approval, 30 patients were interviewed between August and November 2016 during the perioperative period while undergoing an elective hip or knee arthroplasty (n = 30). The interviews were performed between the day of surgery and a nine-week postoperative clinic appointment. Data were analysed using an in-depth narrative thematic analysis method. NVivo qualitative data analysis software was used.

RESULTS

Seven main themes evolved from the interviews: "improving function and mobility", "pain", "experiences of health care", "support from others", "involvement and understanding of care decisions", "behaviour and coping" and "fatigue and sleeping".

CONCLUSIONS

The early postoperative recovery period is of vital importance to all surgical patients. This is no different for the orthopaedic patient. However, identifying key self-reported areas of importance from patients can guide clinical focus for healthcare professionals.

RELEVANCE TO CLINICAL PRACTICE

To have specific patient-reported information regarding key areas of importance during the perioperative phase is invaluable when caring for the orthopaedic surgical patient. It gives insight and understanding in to this increasing population group. This study has also served as a starting point in the development of a questionnaire which could be used to assess interventions in the lower limb arthroplasty population. These results will influence both items and content of the questionnaire.

Postoperative Anteroposterior Laxity Influences Subjective Outcome After Total Knee Arthroplasty

BACKGROUND

We hypothesized that postoperative anteroposterior (AP) stability of the knee correlates with patient-reported clinical outcome and knee function after total knee arthroplasty (TKA).

METHODS

This study enrolled 110 knees in 81 patients after TKA. AP laxity was measured with a KS Measure Arthrometer at 30°, 60°, and 90° flexion, which was confirmed with a goniometer. We assessed knee pain and function by using the Knee Society Function Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Correlations among AP translation values and KOOS subscale scores (pain symptom, activities of daily living, and knee-related quality of life), KSS, and range of motion (ROM) were analyzed.

RESULTS

The mean follow-up period for the assessment of the KOOS was 4.4 ± 2.2 years (range, 1.1-11.5 years). Twenty-five knees had posterior-stabilized fixed-bearing TKA, and 85 knees had posterior-stabilized mobile-bearing TKA. The mean KSS functional score and mean ROM were 96.3 ± 5.7 (range, 75-100) and 121.6° ± 14.4° (range, 90°-145°), respectively. The mean AP laxity was 4.5 ± 2.2 mm, 3.6 ± 1.9 mm, and 3.0 ± 1.9 mm at 30°, 60°, and 90° knee flexion, respectively. A significant inverse association was observed between AP laxity at 60° knee flexion and KOOS pain (P = .02^∗, R² = 0.05), but no significant association was found between AP laxity and other KOOS subscale score, KSS, and ROM.

CONCLUSION

We found that the AP laxity at 60° knee flexion in this study significantly correlated with patient-reported pain. The observed AP laxity can be considered as a register of normal AP translations after arthroplasty.

Does Addition of Multimodal Periarticular Analgesia to Adductor Canal Block Improve Lengths of Stay, Pain, Discharge Status, and Opioid Use After Total Knee Arthroplasty?

BACKGROUND

Postoperative pain after total knee arthroplasty (TKA) can be burdensome. Multiple methods of pain control have been used, including adductor canal block (ACB) and multimodal periarticular analgesia (MPA). These two techniques have been studied have proven to be efficacious separately. The purpose of this study was to compare: (1) lengths of stay (LOS), (2) pain level, (3) discharge status, and (4) opioid use in TKA patients who received ACB alone vs patients who received ACB and MPA.

METHODS

A single surgeon database was reviewed for patients who had a TKA between January 2015 and April 2016. Patients who received ACB with or without MPA were included. This yielded 127 patients who had a mean age of 63 years. Patients were grouped into having received ACB alone (n = 52) and having received ACB and MPA (n = 75). Patient records were reviewed to obtain demographic and end point data (LOS, pain, discharge status, and opioid use). Student t test and chi-squared test were used to compare continuous and categorical variables respectively.

RESULTS

There were no significant difference in mean LOS (P = .934), pain level (P = .142), discharge status (P = .077), or total opioid use (P = .708) between the 2 groups.

CONCLUSION

There was no significant difference in LOS, pain levels, discharge status, and opiate requirements between the 2 groups. ACB alone may be as effective as combined ACB and MPA in TKA patients for postoperative pain control. Larger prospective studies are needed to verify these findings and to improve generalization.