No Clinically Important Difference in Pain Scores After THA Between Periarticular Analgesic Injection and Placebo: A Randomized Trial

Efficacy of Ultrasound-Guided Pericapsular Nerve Group (PENG) Block Combined With Local Infiltration Analgesia on Postoperative Pain After Total Hip Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Trial

BACKGROUND

This study examined whether pericapsular nerve group (PENG) block combined with local infiltration analgesia (LIA) could improve pain management and functional recovery after total hip arthroplasty.

METHODS

All patients were randomly assigned to receive PENG block combined with LIA (PENG group) or sham PENG block and LIA (Sham group). The primary outcome was cumulative morphine consumption within 24 hours after surgery. Secondary outcomes were pain scores on a visual analog scale (VAS); time to first rescue analgesia; cumulative morphine consumption during hospitalization; intraoperative consumption of opioids; postoperative recovery; and postoperative complications.

RESULTS

PENG patients consumed significantly less morphine within the first 24 hours and throughout hospitalization and smaller amounts of intraoperative opioids. There were significantly lower pain scores at rest and during motion within 24 hours in PENG patients. PENG patients took significantly longer until the first rescue analgesia and showed significantly better postoperative rehabilitation. However, the absolute change in morphine consumption and VAS scores did not exceed the reported minimal clinically important differences (morphine consumption: 10 mg; VAS scores: 1.5 at rest and 1.8 during movement). The two groups showed no difference in quadriceps muscle strength and postoperative complications.

CONCLUSION

PENG block combined with LIA could improve postoperative pain relief, reduce opioid use, and enhance recovery in total hip arthroplasty patients, without weakening the quadriceps muscle strength. This work justifies further trials to examine the safety and efficacy of this block and to explore maximal effective volume of local anesthetic for motor-sparing PENG block.

Early Stage Versus Late Stage Periarticular Injection during Unicompartmental Knee Arthroplasty for Postoperative Pain Relief: A Randomized Controlled Trial

Controlling postoperative pain after unicompartmental knee arthroplasty (UKA) is essential to improve patient satisfaction and promote early recovery. The purpose of this study was to investigate the difference in clinical efficacy between early and late stage periarticular injection during UKA for postoperative pain relief. Eighty-four patients meeting the inclusion and exclusion criteria were randomly divided into the early stage periarticular injection group and late stage periarticular injection group by using a random number tables method. The difference between the two groups was that the early stage periarticular injection group received superficial injection before the joint incision, while the late stage periarticular injection group received superficial injection after implantation of the prosthesis. Deep injection and other perioperative conditions of the two groups were controlled identically. The primary outcome of the study was the recovery room immediate visual analog scale (VAS) at rest. The secondary outcomes were the postoperative VAS (at rest) at 3, 6, 9, 12, 18, 24, 48, 72, 96, and 120 hours, drug dosage of rescue analgesia, range of motion (ROM), and complications. The recovery room immediate VAS (at rest) in the early stage periarticular injection group was significantly lower than that of the late stage periarticular injection group (21 ± 24 vs. 32 ± 34 mm, p = 0.018), the average difference of the VAS reached the minimal clinically important difference. No statistically significant difference in postoperative drug dosage of rescue analgesia, ROM, and complications. Preemptive analgesia combined with the early stage periarticular injection can better alleviate postoperative pain than the late stage periarticular injection.

Spinal Compared with General Anesthesia in Contemporary Primary Total Hip Arthroplasties

BACKGROUND

The specific advantages of spinal anesthesia compared with general anesthesia for primary total hip arthroplasty (THA) remains unknown. Therefore, this study aimed to investigate the pain control, length of stay, and postoperative outcomes associated with spinal anesthesia compared with general anesthesia in a large cohort of primary THAs from a single, high-volume academic institution.

METHODS

We retrospectively identified 13,730 primary THAs (11,319 patients) from 2001 to 2016 using our total joint registry. Of these cases, 58% had general anesthesia and 42% had spinal anesthesia. The demographic characteristics were similar between groups, with mean age of 64 years, 51% female, and mean body mass index (BMI) of 31 kg/m 2 . Data were analyzed using an inverse probability of treatment weighted model based on a propensity score that accounted for numerous patient and operative factors. The mean follow-up was 6 years.

RESULTS

Patients treated with spinal anesthesia had lower Numeric Pain Rating Scale (NPRS) scores (p < 0.001) and required fewer postoperative oral morphine equivalents (OMEs) at all time points evaluated (p < 0.001). Patients treated with spinal anesthesia also had shorter hospital length of stay (p = 0.02), fewer altered mental status events (odds ratio [OR], 0.7; p = 0.02), and fewer intensive care unit (ICU) admissions (OR, 0.7; p = 0.01). There was no difference in the incidence of deep vein thrombosis (p = 0.8), pulmonary embolism (p = 0.4), 30-day readmissions (p = 0.17), 90-day readmissions (p = 0.18), all-cause revisions (p = 0.17), or all-cause reoperations (p = 0.14).

CONCLUSIONS

In this large, single-institution study, we found that spinal anesthesia was associated with reduced pain scores and OME use postoperatively. Furthermore, spinal anesthesia resulted in fewer altered mental status events and ICU admissions. These data favor the use of spinal anesthesia in primary THAs.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The role for high volume local infiltration analgesia with liposomal bupivacaine in total hip arthroplasty: A scoping review

Introduction

Liposomal bupivacaine has been integrated into clinical practice within many surgical disciplines to reduce post-operative pain and opioid consumption. This novel agent has been utilized in this regard in many subdisciplines of orthopedic surgery. Total hip arthroplasty has significant opioid use post-operatively as compared to many other orthopedic disciplines.

Objectives

The purpose of the present investigation is to summarize the current use of liposomal bupivacaine after total hip arthroplasty and to shed light on the prospect of liposomal bupivacaine to reduce opioid use after total hip arthroplasty. A tertiary purpose is to identify future areas of adjunctive pain measures that can assist in the reduction of opioid use after total hip arthroplasty.

Methods

This IRB-exempt scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist strictly. The literature search was performed in Mendeley. Search fields were varied until redundant. All articles were screened by title and abstract and a preliminary decision to include an article was made. The full-text screening was performed on the selected articles. Any question regarding the inclusion of an article was discussed by three authors until an agreement was reached.

Results

A total of 21 articles were included for qualitative description of the opioid epidemic, opioid overuse in total hip arthroplasty, and risk factors for opioid overuse in total hip arthroplasty. A total of 9 articles were included regarding the use of liposomal bupivacaine in total hip arthroplasty. Several risk factors have been identified for opioid overuse after total hip arthroplasty. These include younger age, an opioid risk tool score of > 7, a higher body mass index, chronic obstructive pulmonary disease, immunodeficiency syndromes, preexisting pain syndromes, peripheral vascular disease, anxiety and mood disorders, and substance abuse disorders. Liposomal bupivacaine reduces postoperative opioid use, patient-reported outcomes, length of stay, and time to ambulation, yet is more expensive than traditional bupivacaine.

Conclusions

Liposomal bupivacaine represents a useful adjunct for multimodal pain strategies in total hip arthroplasty with sufficient evidence to suggest that it may be useful in decreasing postoperative opioid use. The high costs of LB represent a barrier to institutional acceptance of LB into standardized multimodal pain strategies. Further efforts should be aimed toward better understanding the current state of integration of LB into academic and private practice settings, industry movements to decrease the cost, and the role other adjunctive measures may have in reducing post-operative opioid use.

Does the Use of an Intra-Articular Local Anesthetic Injection During Total Hip Arthroplasty Reduce Patient Reported Pain Scores or Patient Opioid Consumption?

BACKGROUND

During primary total hip arthroplasty (THA), some surgeons use an intra-articular injection (IAI) containing 200 mg ropivacaine to target postoperative pain. There is no clear consensus on the efficacy of an IAI alone. The purpose of this study is to evaluate the effect of a 200 mg ropivacaine IAI on pain scores, opioid consumption, and mobility for primary THA patients.

METHODS

We retrospectively reviewed 571 patients who underwent primary THA at a single institution. Patients were grouped according to those who received a 200 mg ropivacaine IAI and those who did not. Primary outcome measures for this study included pain scores, morphine milligram equivalents (MMEs) dosed, distance of ambulation achieved, and time to ambulation.

RESULTS

The intervention group reported higher average pain scores with activity than the control group (P = .024). The intervention group also required higher MMEs. When striated by hour, a statistically significant uptick in pain started at 16 hours (P = .0009) and persisted to 28 hours (P = .032) in patients receiving a 200 mg ropivacaine IAI. This correlated with an increase in MMEs seen at hour 24 through 32 (P = .003 to P = .012). Level of ambulation, time to ambulation, and distance ambulated did not differ between groups. An IAI of 200 mg ropivacaine also appeared to lead to higher pain scores and higher opioid doses in males.

CONCLUSION

The IAI does not appear to reduce postoperative pain scores or MMEs dosed for THA patients. More research is needed to look at the utilization and efficacy of intra-articular ropivacaine, especially focusing on functional outcomes and gender differences.

The impact of ultrasound-guided transmuscular quadratus lumborum block combined with local infiltration analgesia for arthroplasty on postoperative pain relief

STUDY OBJECTIVE

This study aimed to evaluate the efficacy of ultrasound-guided transmuscular quadratus lumborum block (QLB) combined with local infiltration analgesia (LIA) for pain management and recovery in patients who have undergone total hip arthroplasty (THA) via a posterolateral approach.

DESIGN

This was a prospective, randomized controlled trial.

SETTING

We collected data in the preoperative area, operating room, and bed ward.

PATIENTS

A total of 80 patients with American Society of Anesthesiology functional status scores of II-III were included and assigned to two groups, and all 80 patients were included in the final analysis.

INTERVENTIONS

All included patients were randomly assigned to the nerve block (group N) or the control group (group C). Patients in the group N received transmuscular QLB combined with LIA, while patients in the group C received only LIA.

MEASUREMENTS

The primary outcome was postoperative pain during the first active motion: it was measured at six hours after surgery and assessed using a visual analog scale (VAS). Secondary outcomes were the resting VAS scores in the post-anesthesia care unit (PACU) and at 2, 6, 12, 24, 48, and 72 h after surgery; VAS scores during motion at 12, 24, 48, and 72 h after surgery; intraoperative consumption of opioids; postoperative consumption of morphine hydrochloride; frequency of sleep interruption due to pain on the night of surgery; time until the first "walk out of the bed" after surgery; muscle strength of the quadriceps femoris; and postoperative adverse effects.

MAIN RESULTS

Compared to the group C, patients in the group N had significantly lower VAS scores during motion at 6, 12, and 24 h after surgery, as well as lower resting VAS scores in the PACU and at 2, 6, 12, and 24 h after surgery. Patients in the group N also consumed significantly smaller amounts of intraoperative opioids and morphine after surgery. Patients in the group N reported significantly fewer interruptions in sleep due to pain on the night of surgery and were able to "walk out of the bed" significantly earlier than those in the group C. There was no significant difference between the two groups in muscle strength of the quadriceps femoris or incidence of postoperative adverse effects.

CONCLUSIONS

Compared to treatment with LIA alone, ultrasound-guided transmuscular QLB combined with LIA can provide better postoperative pain relief and enhance the recovery of THA patients, since it does not cause quadriceps femoris muscle weakness and is associated with significantly lower need for intraoperative opioids.

PROSPECT guideline for total hip arthroplasty: a systematic review and procedure-specific postoperative pain management recommendations

The aim of this systematic review was to develop recommendations for the management of postoperative pain after primary elective total hip arthroplasty, updating the previous procedure-specific postoperative pain management (PROSPECT) guidelines published in 2005 and updated in July 2010. Randomised controlled trials and meta-analyses published between July 2010 and December 2019 assessing postoperative pain using analgesic, anaesthetic, surgical or other interventions were identified from MEDLINE, Embase and Cochrane databases. Five hundred and twenty studies were initially identified, of which 108 randomised trials and 21 meta-analyses met the inclusion criteria. Peri-operative interventions that improved postoperative pain include: paracetamol; cyclo-oxygenase-2-selective inhibitors; non-steroidal anti-inflammatory drugs; and intravenous dexamethasone. In addition, peripheral nerve blocks (femoral nerve block; lumbar plexus block; fascia iliaca block), single-shot local infiltration analgesia, intrathecal morphine and epidural analgesia also improved pain. Limited or inconsistent evidence was found for all other approaches evaluated. Surgical and anaesthetic techniques appear to have a minor impact on postoperative pain, and thus their choice should be based on criteria other than pain. In summary, the analgesic regimen for total hip arthroplasty should include pre-operative or intra-operative paracetamol and cyclo-oxygenase-2-selective inhibitors or non-steroidal anti-inflammatory drugs, continued postoperatively with opioids used as rescue analgesics. In addition, intra-operative intravenous dexamethasone 8-10 mg is recommended. Regional analgesic techniques such as fascia iliaca block or local infiltration analgesia are recommended, especially if there are contra-indications to basic analgesics and/or in patients with high expected postoperative pain. Epidural analgesia, femoral nerve block, lumbar plexus block and gabapentinoid administration are not recommended as the adverse effects outweigh the benefits. Although intrathecal morphine 0.1 mg can be used, the PROSPECT group emphasises the risks and side-effects associated with its use and provides evidence that adequate analgesia may be achieved with basic analgesics and regional techniques without intrathecal morphine.

How effective is periarticular multimodal drug injection in open elbow arthrolysis? A prospective double-blind randomized controlled trial

BACKGROUND

Evidence on the efficacy and safety of periarticular multimodal drug injection (PMDI) in open elbow arthrolysis (OEA) is limited. This study aimed to investigate differences in postoperative pain, blood loss, and range of motion (ROM) between PMDI vs. no injection among patients undergoing OEA, and the presence of PMDI-related complications.

METHODS

This prospective, double-blind randomized controlled trial included 59 patients who underwent OEA. Patients randomly received PMDI (ropivacaine, epinephrine, ketoprofen) before wound closure or no injection. The primary outcomes were elbow pain over the first postoperative week at rest and during motion, measured using the visual analog scale (VAS). VAS scores were compared to attain the 20-mm threshold values for a minimum clinically important difference. Parecoxib consumption on OEA night and postoperative days (PODs) 1-3 and total consumption during the first postoperative week were recorded. Blood loss was recorded every 24 hours until POD 3. ROM during rehabilitation was measured daily from day 1 to day 7 after surgery, as well as at 3-month follow-up. Medication-related side effects were recorded prospectively.

RESULTS

The mean VAS score showed clinically important differences between PMDI and control groups at rest on OEA night (mean difference [MD], 25 mm; P < .001) and first 3 PODs with motion (POD 1: MD, 28 mm, P < .001; POD 2: MD, 21 mm, P < .001; POD 3: MD, 21 mm, P < .001) but not in other postoperative assessments. Parecoxib consumption was lower in the PMDI group on OEA night and PODs 1-3. Total parecoxib consumption during the first postoperative week was lower in the PMDI group vs. the control group (MD, 148 mg; P < .001). Blood drainage was less in the PMDI group vs. the control group on POD 1 (MD, 38 mL; P = .016) but not on POD 2 (P = .950), POD 3 (P = .259), or total (P = .184). The PMDI group exhibited significantly better ROM during the first 4 PODs than the control group, whereas there was no difference at 3-month follow-up. No medication-related side effects were noted in the PMDI group.

CONCLUSION

PMDI effectively relieves pain and reduces analgesic consumption for OEA patients, without an apparent increase in risks.

Periarticular analgesic injection containing a corticosteroid after total hip arthroplasty may prevent deep venous thrombosis: a retrospective comparative cohort study

BACKGROUND

Of late, periarticular analgesic injection (PAI) has become a common alternative treatment for pain following total hip arthroplasty (THA). However, the systemic effects of PAI containing corticosteroids in patients subjected to THA have not been investigated. This study evaluated the analgesic efficacy and systemic effects of PAI containing a corticosteroid in patients subjected to THA.

METHODS

This single-center, retrospective cohort study enrolled patients undergoing unilateral, primary THA. A total of 197 patients (200 hips) were included in the final analyses, with 87 hips in the PAI group and 113 hips in the control group. Numeric Rating Scale (NRS) and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7. Pearson's correlation coefficients were obtained to assess the correlations between the D-dimer level on POD 7 and each outcome measure on POD 1.

RESULTS

The postoperative white blood cell count (WBC) was significantly higher in the PAI group than in the control group. Postoperative NRS, creatine phosphokinase (CK), and C-reactive protein (CRP) levels were significantly lower in the PAI group. D-dimer levels were significantly lower in the PAI group on POD 7. Postoperative aspartate transaminase (AST), alanine aminotransferase, blood urea nitrogen, and creatinine levels were within reference ranges. D-dimer levels on POD 7 showed a significant negative correlation with WBC on POD 1 (r=-0.4652) and a significant positive correlation with the NRS score and AST, CK, CRP, and D-dimer levels on POD 1 (r = 0.1558, 0.2353, 0.2718, 0.3545, and 0.3359, respectively).

CONCLUSIONS

PAI containing a corticosteroid may be an effective treatment for pain and inflammation after THA, and it does not seem to cause drug-induced liver or kidney injury. Moreover, corticosteroid PAI can may accelerate early ambulation, which prevents the elevation of postoperative D-dimer levels, and may reduce the risk of deep venous thrombosis.

Effect of Perioperative Active Body Surface Warming Systems on Analgesic and Clinical Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Inadvertent perioperative hypothermia is a common complication of surgery, and active body surface warming (ABSW) systems are used to prevent adverse clinical outcomes. Prior data on certain outcomes are equivocal (ie, blood loss) or limited (ie, pain and opioid consumption). The objective of this study was to provide an updated review on the effect of ABSW on clinical outcomes and temperature maintenance.

METHODS

We conducted a systematic review of randomized controlled trials evaluating ABSW systems compared to nonactive warming controls in noncardiac surgeries. Outcomes studied included postoperative pain scores and opioid consumption (primary outcomes) and other perioperative clinical variables such as temperature changes, blood loss, and wound infection (secondary outcomes). We searched Ovid MEDLINE daily, Ovid MEDLINE, EMBASE, CINHAL, Cochrane CENTRAL, and Web of Science from inception to June 2019. Quality of evidence (QoE) was rated according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Subgroup analysis sought to determine the effect of preoperative + intraoperative warming versus intraoperative warming alone. Metaregression evaluated the effect of year of publication, use of neuromuscular blockers, anesthesia, and surgery type on outcomes.

RESULTS

Fifty-four articles (3976 patients) were included. Pooled results demonstrated that ABSW maintained normothermia compared to controls, during surgery (30 minutes postinduction [mean difference {MD}: 0.3°C, 95% confidence interval {CI}, 0.2-0.4, moderate QoE]), end of surgery (MD: 1.1°C, 95% CI, 0.9-1.3, high QoE), and up to 4 hours postoperatively (MD: 0.3°C, 95% CI, 0.2-0.5, high QoE). ABSW was not associated with difference in pain scores (<24 hours postoperatively, moderate to low QoE) or perioperative opioid consumption (very low QoE). ABSW increased patient satisfaction (MD: 2.2 points, 95% CI, 0.9-3.6, moderate QoE), reduced blood transfusions (odds ratio [OR] = 0.6, 95% CI, 0.4-1.0, moderate QoE), shivering (OR = 0.2, 95% CI, 0.1-0.4, high QoE), and wound infections (OR = 0.3, 95% CI, 0.2-0.7, high QoE). No significant differences were found for fluid administration (low QoE), blood loss (very low QoE), major adverse cardiovascular events (very low QoE), or mortality (very low QoE). Subgroup analysis and metaregression suggested increased temperature benefit with pre + intraoperative warming, use of neuromuscular blockers, and recent publication year. ABSW seemed to confer less temperature benefit in cesarean deliveries and neurosurgical/spinal cases compared to abdominal surgeries.

CONCLUSIONS

ABSW is effective in maintaining physiological normothermia, decreasing wound infections, shivering, blood transfusions, and increasing patient satisfaction but does not appear to affect postoperative pain and opioid use.

Addition of corticosteroid to periarticular injections reduces postoperative pain following total hip arthroplasty under general anaesthesia: a double-blind randomized controlled trial

Aims

Although periarticular injection plays an important role in multimodal pain management following total hip arthroplasty (THA), there is no consensus on the optimal composition of the injection. In particular, it is not clear whether the addition of a corticosteroid improves the pain relief achieved nor whether it is associated with more complications than are observed without corticosteroid. The aim of this study was to quantify the safety and effectiveness of cortocosteroid use in periarticular injection during THA.

Methods

We conducted a prospective, two-arm, parallel-group, randomized controlled trial involving patients scheduled for unilateral THA. A total of 187 patients were randomly assigned to receive periarticular injection containing either a corticosteroid (CS group) or without corticosteroid (no-CS group). Other perioperative interventions were identical for all patients. The primary outcome was postoperative pain at rest during the initial 24 hours after surgery. Pain score was recorded every three hours until 24 hours using a 100 mm visual analogue scale (VAS). The primary outcome was assessed based on the area under the curve (AUC).

Results

The CS group had a significantly lower AUC postoperatively at 0 to 24 hours compared to the no-CS group (AUC of VAS score at rest 550 ± 362 vs 392 ± 320, respectively; mean difference 158 mm; 95% confidence interval (CI) 58 to 257; p = 0.0021). In point-by-point evaluation, the CS group had significantly lower VAS scores at 12, 15, 18, 21, 24, and 48 hours. There were no significant differences in complication rates, including surgical site infection, between the two groups.

Conclusion

The addition of corticosteroid to periarticular injections reduces postoperative pain without increasing complication rate following THA.

Cite this article: Bone Joint J 2020;102-B(10):1297–1302.

Comparison of Early-Stage and Late-Stage Periarticular Injection for Pain Relief After Total Hip Arthroplasty: A Double-Blind Randomized Controlled Trial

BACKGROUND

No randomized controlled trial has investigated a more optimal timing of periarticular injection for pain relief after total hip arthroplasty.

METHODS

The study included 140 patients, and these patients were randomly allocated to the early-stage (periarticular injection was performed just before arthrotomy, and placebo was injected after implantation) or late-stage (placebo was injected just before arthrotomy, and periarticular injection was performed after implantation) injection groups. Other perioperative interventions were similar in all participants. The prespecified primary outcome was postoperative pain score at the recovery room.

RESULTS

The visual analog scale score at the recovery room of the early-stage injection group was significantly lower than that of the late-stage injection group (30 ± 28 vs 46 ± 30 mm; 95% CI, -25 to -5 mm; P = .0022), and this difference reaches a minimal clinically important difference level of 10 mm. No differences were observed with regard to complication rate.

CONCLUSION

Early-stage periarticular injection during total hip arthroplasty provided better postoperative pain relief than late-stage periarticular injection without elevating complication rate.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

The efficacy of intraoperative periarticular injection in Total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Periarticular injection (PAI) is a regional analgesia method performed in total hip arthroplasty (THA) for postoperative pain relief. However, its efficacy and safety is still inconclusive. Therefore, we conducted this meta-analysis to assess the safety of PAI and to determine if PAI provides better pain relief and reduce the consumption of opioids after THA.

METHODS

We searched PubMed, Web of Science, Embase and the Cochrane Library comprehensively. Only randomized control trials were included in our meta-analysis. Eleven studies that compared the efficacy of PAI with the control group were included. The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines and Jadad score were applied to assess the quality of the included studies. We used the recommendations by the Cochrane Collaboration to reduce bias and to ensure our results were reliable and veritable.

RESULTS

Our analysis demonstrated that PAI was more effective than the control group with a lower visual analog scale (VAS) score during rest at 24 h (P = 0.003), 48 h (P = 0.002), and VAS score with activity at 24 h (P = 0.04). There was also less amount of opioid consumption (P = 0.01). There were no differences in length of hospital stay (P = 0.526) and postoperative nausea rate (P = 0.153).

CONCLUSION

Compared with the control group, PAI showed better pain relief and less amount of opioid consumption after THA. Our meta-analysis suggests that PAI is a safe and effective multimodal analgesia technique that can be used for THA.

Early stage periarticular injection during total knee arthroplasty may provide a better postoperative pain relief than late-stage periarticular injection: a randomized-controlled trial

PURPOSE

This study was performed to determine whether periarticular injection performed in the early stage of total knee arthroplasty (TKA) could provide a better postoperative pain relief than periarticular injection performed in the late stage of TKA. The hypothesis was based on the concept that analgesic intervention before the onset of noxious stimuli would be associated with less postoperative pain.

METHODS

A total of 105 participants were randomly assigned to receive superficial injection just prior to arthrotomy (early stage periarticular injection group) or superficial injection after implanting the prosthesis (late-stage periarticular injection group) in patients undergoing unilateral TKA with 1:1 treatment allocation. In both groups, deep injection was performed according to the same schedule (just prior to implanting prosthesis). The solution consisted of 300 mg of ropivacaine, 8 mg of morphine, 40 mg of methylprednisolone, 50 mg of ketoprofen, and 0.3 mg of epinephrine mixed with normal saline to a final volume of 60 mL. All surgeries were managed under general anesthesia without any regional blocks. Registry-specified primary outcome was postoperative pain score at rest measured at the recovery room using a 100-mm visual analog scale (VAS). The VAS score was compared between two groups and assessed to reach the reported threshold values for the minimal clinically important difference (MCID) of 10 mm for the postoperative VAS score.

RESULTS

The VAS score at the recovery room was significantly lower in the early stage periarticular injection group than the late-stage periarticular injection group (23 ± 25 mm versus 39 ± 34 mm, respectively; 95% confidence interval 4-28 mm; p = 0.0078). The mean difference in the primary outcome fulfilled the MCID value.

CONCLUSIONS

Bringing forward the timing of periarticular injection may provide significant and clinically meaningful improvement in pain following TKA under general anesthesia.

LEVEL OF EVIDENCE

I.