A systematic review and meta-analysis of the hip capsule innervation and its clinical implications

Ultrasound-guided suprainguinal fascia iliaca compartment block and early postoperative analgesia after total hip arthroplasty: a randomised controlled trial

BACKGROUND

Hip replacement surgery can be painful; postoperative analgesia is crucial for comfort and to facilitate recovery. Regional anaesthesia can reduce pain and postoperative opioid requirements. The role of ultrasound-guided suprainguinal fascia iliaca block for analgesia after elective total hip arthroplasty is not well defined. This randomised trial evaluated its analgesic efficacy.

METHODS

Consenting participants (134) scheduled for elective primary total hip arthroplasty under spinal anaesthesia were randomly allocated to receive ultrasound-guided fascia iliaca block with ropivacaine 0.5% or sham block with saline. The primary outcome was opioid consumption in the first 24 h after surgery. Additional outcomes included pain scores at 4, 8, 12, and 16 h, opioid-related side-effects (nausea, vomiting, pruritis), ability to perform physiotherapy on the first postoperative day, and physiotherapist-assessed quadriceps weakness.

RESULTS

There were no significant differences in 24-h opioid consumption (block vs sham block, mean difference -3.2 mg oral morphine equivalent, 95% confidence interval -15.3 to 8.1 mg oral morphine equivalent, P=0.55) or any other prespecified outcomes.

CONCLUSIONS

In patients undergoing primary total hip arthroplasty, ultrasound-guided suprainguinal fascia iliaca block with ropivacaine did not confer a significant opioid-sparing effect compared with sham block. There were no differences in other secondary outcomes including pain scores, opioid-related side-effects, or ability to perform physiotherapy on the first postoperative day.

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CLINICALTRIALS

gov (NCT03069183).

Effects of Different Volumes of Ropivacaine for Pericapsular Nerve Group Block on Incidence of Quadriceps Weakness and Analgesic Efficacy Following Hip Arthroplasty: A Randomized Controlled Trial

INTRODUCTION

The pericapsular nerve group (PENG) block has been shown to be an effective approach to alleviating pain and reducing the need for opioids among older adults following hip surgery, with possible motor-sparing effects. No reports to date, however, have described appropriate ropivacaine volumes for use in the context of PENG block. The present prospective randomized controlled study was thus developed to assess the quadriceps muscle strength and analgesic efficacy associated with PENG block performed using three different volumes of 0.33% ropivacaine following general anesthesia in older adults undergoing hip arthroplasty.

METHODS

In this prospective randomized double-blind controlled clinical study, 60 patients were assigned at random to undergo ultrasound-guided PENG block for hip arthroplasty using different volumes of ropivacaine. Specifically, these patients were administered 10 ml (Group A, n = 20), 20 ml (Group B, n = 20), or 30 ml (Group C, n = 20) of 0.33% ropivacaine. Quadriceps muscle strength was evaluated at 6 h post-surgery. Visual analog scale (VAS) scores at rest and with movement were assessed at 4, 6, 12, and 24 h post-surgery. Block duration, adverse event incidence, and patient satisfaction were evaluated at 24 h post-surgery.

RESULTS

Quadriceps motor block incidence rates at 6 h post-surgery in the 10 ml, 20 ml, and 30 ml groups were 5%, 20%, and 75%, respectively. Quadriceps muscle weakness at 6 h post-surgery was significantly more common in the 30 ml group relative to the others (p < 0.001). Patients administered 10 ml 0.33% ropivacaine exhibited significantly higher VAS pain scores at rest and with movement relative to those patients in the 20 ml and 30 ml treatment groups at all time points (p < 0.05). No apparent differences in analgesic efficacy were observed when comparing the 20 ml and 30 ml groups at 4, 6, 12, and 24 h post-surgery. No significant differences in block duration, satisfaction, or adverse event incidence were observed among groups.

CONCLUSIONS

The preservation of motor function in the 20 ml 0.33% ropivacaine group was superior to that in the 30 ml 0.33% ropivacaine group. Relative to the group that received 10 ml 0.33% ropivacaine during PENG block, those elderly patients administered 20 ml and 30 ml volumes of 0.33% ropivacaine experienced superior postoperative pain relief following hip arthroplasty.

Editorial Commentary: Hip Arthroscopy Pain Management With Surgeon-Administered Pericapusular Injection Is Fast, Safe, Inexpensive, and Effective

Regional pain management after hip arthroscopy is challenging. The hip capsule alone has a complex and highly variable innervation, including contributions from articular branches of the femoral, obturator, accessory obturator, accessory femoral, superior gluteal, accessory superior gluteal, inferior gluteal, sciatic, and posterior femoral cutaneous nerves, nerve to the quadratus femoris, as well as a direct supply from the lumbosacral plexus. Thus, it is unrealistic to expect a traditional peripheral nerve block, including blocks of the proximal lumbar plexus, femoral nerve, and fascia iliaca region to provide thorough hip analgesia without inducing quadriceps weakness that could result in a patient experiencing a fall during the postoperative period. In addition, newer, sensory-only blocks, such as quadratus lumborum or pericapsular nerve group blocks, have not been shown to be superior to simple pericapsular injection (PCI). Hip arthroscopy pain management using surgeon administered PCI is fast, safe, inexpensive, and effective. While not perfect, PCI is the best option among current choices.

Arthroscopic Hip Capsular Repair Improves Patient-Reported Outcome Measures and Is Associated With a Decreased Risk of Revision Surgery and Conversion to Total Hip Arthroplasty

Purpose

To perform a systematic review to assess the effect of capsular repair compared with nonrepair on patient-reported outcome measures (PROMs) and conversion to total hip arthroplasty (THA) after hip arthroscopy in patients with femoroacetabular impingement syndrome.

Methods

We initially searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PubMed databases, as well as ongoing clinical trials (https://clinicaltrials.gov), on December 15, 2022. The eligibility criteria were randomized controlled trials (Level Ⅰ) and prospective comparative studies (Level II) of patients who underwent capsular repair and nonrepair via hip arthroscopy with a minimum follow-up period of 2 years. We registered this protocol a priori on PROSPERO (identification No. CRD42021239306). We assessed the risk of bias using the Methodological Index for Non-randomized Studies (MINORS) appraisal tool.

Results

This review included 5 studies with a total of 639 patients (270 with capsular repair [average age, 35.4 years; 41% female patients] and 369 with nonrepair [average age, 37.3 years; 38% female patients]). In the included studies, surgical procedures consisting of labral repair and pincer or cam osteoplasty were performed via hip arthroscopy. The modified Harris Hip Score was measured in all the included studies, and the standardized mean difference in PROMs for capsular repair versus nonrepair in the included studies was 0.42 (95% confidence interval [CI], 0.20 to 0.63). A sensitivity analysis of randomized controlled trials achieved consistent results (standardized mean difference in PROMs, 0.31; 95% CI, 0.02 to 0.60). Capsular repair was not associated with a reduction in revision surgery (risk difference, -0.02; 95% CI, -0.06 to 0.03; 26 of 270 patients with capsular repair vs 42 of 369 with nonrepair) but was associated with a reduction in conversion to THA (risk difference, -0.05; 95% CI -0.09 to -0.01; 12 of 270 patients with capsular repair vs 38 of 369 with nonrepair). The average Methodological Index for Non-randomized Studies (MINORS) score in the included studies was 20.

Conclusions

Patients who undergo capsular repair in conjunction with other arthroscopic hip preservation techniques have better PROMs and a lower incidence of THA conversion.

Level of Evidence

Level II, systematic review of Level I and II investigations.

The Analgesic effect of adding ultrasound-guided pericapsular nerve group block to suprainguinal fascia iliaca compartment block for hip fracture surgery: A prospective randomized controlled trial

BACKGROUND

Both suprainguinal ultrasound-guided fascia iliaca compartment block (FICB) and pericapsular nerve group (PENG) block have been used to treat pain after hip surgery. Motor-sparing PENG block may further expedite early postoperative rehabilitation. This study aimed to compare the analgesic efficacy and recovery outcome of suprainguinal ultrasound-guided FICB alone with FICB combined with PENG block for hip fracture surgery.

METHODS

In this study, 59 elderly patients undergoing hip fracture surgery were randomized to receive either FICB alone or combined FICB + PENG block. The primary outcome was pain score at rest 12 hours after surgery as measured by the numerical rating scale (NRS, 0-10) and secondary outcomes were pain scores at rest and with movement measured at other time points within 48 hours, time to first sit up without pain, rescue morphine requirements, opioid-related side effects, incidence of delirium, in-hospital morbidities and mortality, and length of hospital stay.

RESULTS

Both patient groups had similar demographic profile and postoperative pain scores at rest and with movement. Median NRS pain scores at rest between FICB alone or combined FICB + PENG block at 4, 8, 12, 24, 36 and 48 hours after surgery were 3 versus 3 (P = .31), 3 versus 3 (P = .21) and 3 versus 3 (P = .69), 2 versus 2 (P = .35), 2 versus 3 (P = .17), 3 versus 2 (P = .18) respectively and NRS during movement at 12, 24, 48 hours were 10 versus 8 (P = .30), 6 versus 5 (P = .54) and 3.5 versus 2.0 (P = .64), respectively. There was also no significant difference in the time for patients to first sit up without pain (17.50 vs 19.37 hours vs h; P = .058) or any other secondary outcome measures. The procedure time was, however, significantly longer for the FICB + PENG block (10 vs 5 minutes, P < .001).

CONCLUSION

Addition of ultrasound-guided PENG block to FICB did not improve postoperative analgesic or recovery outcomes in elderly patients undergoing hip fracture surgery.

Microstructural analysis on the innervation of the anterior, medial, and lateral human hip capsule: Preliminary evidence on its neuromechanical contribution

OBJECTIVE

Capsular repair aims to minimize damage to the hip joint capsular complex (HJCC) and subsequent dislocation risk following total hip arthroplasty (THA). Numerous explanations for its success have been advocated, including neuromuscular feedback loops originating from within the intact HJCC. This research investigates the hypothesis that the HJCC contributes to hip joint stability by analyzing HJCC innervation.

METHOD

Twenty-nine samples from the anterior, medial, and lateral aspects of the midportion HJCC of 29 individuals were investigated stereologically and immunohistochemically to identify encapsulated mechanoreceptors according to a modified Freeman and Wyke classification, totaling 11,745 sections. Consecutive slices were observed to determine the nerve course within the HJCC.

RESULTS

Few encapsulated mechanoreceptors were found in the HJCC subregions and overlying tissues across the cohort studied. Of regions studied, no significant regional differences in the density of mechanoreceptors were found. No significant difference in mechanoreceptor density was found between sides (left, 10.2×10-4/mm3, 4.0×10-4 - 19.0×10-4/mm3; right 12.9×10-4/mm3, 5.0×10-4 - 22.0×10-4/mm3; mean, 95% confidence intervals) sexes (female 10.4×10-4/mm3, 4.0×10-4 - 18.0×10-4/mm3; male 11.6×10-4/mm3, 5.0×10-4 - 20.0×10-4/mm3; mean, 95% confidence intervals), nor in correlation with age demographics. Myelinated nerves coursed consistently within the HJCC in various orientations.

CONCLUSION

Sparse mechanoreceptor density suggests that the HJCC contributes to a limited extent to hip joint stabilization. HJCC nerve terminals may potentially contribute to neuromuscular feedback loops with associated muscles to mediate joint stability in tandem with the active and passive components of the joint.

Single-Shot Lumbar Erector Spinae Plane Block in Total Hip Replacement: A Randomized Clinical Trial

BACKGROUND

Lumbar erector spinae plane block (ESPB) has been proposed to relieve pain after total hip replacement (THR), but high-quality evidence is scarce.

METHODS

This double-blinded (patient and assessor) randomized clinical trial, performed in 2 tertiary centers in Hong Kong, recruited patients undergoing primary unilateral THR under general anesthesia (GA) who received either single-shot ESPB at L1 (treatment arm) or no block (control arm). Patients were followed up on the first day postoperatively. We hypothesized that compared to no block, a single-shot lumbar ESPB at L1 would reduce postoperative fentanyl use and postoperative pain scores. Primary outcomes were intravenous fentanyl use at 12 and 24 hours postoperatively, along with pain intensity in numeric rating scale (0-10) at rest and upon movement on the first day postoperatively. Per-protocol analysis was performed. Mann-Whitney U test was used to compare the outcomes between both groups, and median difference was derived from the Hodges-Lehmann estimator.

RESULTS

Seventy-one patients were randomized (n = 36 in treatment arm, n = 35 in control arm). The median amount of fentanyl consumed at 12 hours postoperatively was 210 (quartiles, 140.5-363) μg for the ESPB group and 165 (quartiles, 77.5-330.5) μg for the control group, while at 24 hours postoperatively, it was 409 (quartiles, 221-636.5) μg for the former and 349 (quartiles, 114-626.5) μg for the latter. The median differences in fentanyl consumption 12 and 24 hours postoperatively were 39 μg (95% confidence interval [CI], -40 to 116; P = .463) and 41 μg, respectively (95% CI, -83.5 to 199.5; P = .474), which were statistically insignificant. The median pain score at rest was 3 for both the ESPB group (quartiles, 0-5) and the control group (quartiles, 0-4.5), while upon movement, it was 7 for both the former (quartiles, 6-8) and the latter (quartiles, 4.5-8.5). The median difference in pain scores between both groups was 0 at rest (95% CI, -1 to 1; P = .890) and upon movement (95% CI, -1 to 1; P = .509).

CONCLUSIONS

This trial did not demonstrate that ESPB at L1 improved analgesia following THR.

A Preliminary Analysis of a Modified Anterior Approach to Hip Pericapsular Neurolysis for Inoperable Hip Fracture Using the IDEAL Framework

Introduction: With an increasingly ageing population, there is a growing impact of fragility hip fracture on the healthcare system and on society as a whole. Oral and injectable analgesics are often insufficient whilst traction and regional blocks do not allow patients to be discharged easily. While the conventional approach of ultrasound-guided anterior hip pericapsular neurolysis can help a lot of inoperable hip fracture patients to relieve their fracture pain and facilitate subsequent nursing care, enormous technical challenges are encountered in some cases. In this retrospective case study, we evaluated the overall pain and functional outcomes of our modified approach of anterior hip pericapsular neurolysis for inoperable hip fractures using the IDEAL framework. Method: This retrospective case series studied patients with acute inoperable hip fracture who received the modified approach of anterior hip pericapsular neurolysis from January 2018 to June 2019 according to the IDEAL recommendations. The modified approach consisted of pericapsular nerve group (PENG) injection, iliopsoas plane infiltration, and the sagittal approach of obturator nerve articular branches (ONAB) injection. Subsequent alcohol neurolysis would be performed in the same setting if there were positive diagnostic blocks. Assessments were carried out on post-intervention day 5. The primary outcome was pain intensity during hip flexion at 80 degrees in the recumbent position and during gentle hip internal and external rotation using an appropriate pain scoring tool. The secondary outcomes were the range of tolerable hip flexion and occurrence of any lower limb neurological deficit because of the procedure. Interim outcomes were also briefly evaluated. Results: Among the 74 patients who were reviewed in the study period, the median dynamic pain at hip flexion 80° (p < 0.001) and on gentle hip external and internal rotation (p < 0.001) was significantly reduced from a composite score of 3 (severe pain) to 1 (mild pain) on post-intervention day 5 after the modified approach of hip neurolysis. This translated to 72% of patients achieving satisfactory pain control, which was defined as a composite pain score of ≤1 on hip flexion at 80°. Functionally, the mean range of tolerable hip flexion significantly improved from 39.7° at baseline to 74° on post-intervention day 5 (p < 0.001). Transient and reversible hypotension was seen in about 10% of the patients. No other major procedural adverse event was noted. Interim follow-up at 4−6 months post-intervention revealed that more than 95% of patients continued to have satisfactory dynamic pain control (i.e., composite pain score ≤ 1). According to the IDEAL classification, this study could be ranked as stage 2a (development). Conclusions: Our findings suggested that anterior hip pericapsular neurolysis using a modified approach could offer consistent and satisfactory analgesic and functional benefits to a majority of patients with inoperable hip fractures during the interim of the fracture healing process, and it was potentially safer than the conventional approach. This technique might have achieved its readiness to proceed to the next stage of research according to the IDEAL framework.

Radiofrequency Ablation of the Trochanteric Branches of the Femoral Nerve for the Treatment of Greater Trochanteric Syndrome

Background

Approximately 10–15% of the population over the age of 60 suffers from hip pain. Greater trochanteric pain syndrome (GTPS) is one of the most common diagnoses in patients with chronic hip pain, includes a number of disorders, and has a broad differential diagnosis. Conservative managements of GTPS, including pharmacologic interventions, physical therapy, chiropractic intervention, acupuncture, and more invasive techniques, such as intra-articular injections, commonly fail to provide patients with sufficient, long-term relief. While radiofrequency ablation (RFA) has been used to treat intra-articular hip pain in the past, there is little evidence for the feasibility of RFA for managing patients with GTPS. This case series builds on previous evidence that cooled radiofrequency ablation (CRF) of the trochanteric branch of the femoral nerve may offer patients with GTPS effective, safe, and lasting pain improvement.

Cases

A series of eight patients with GTPS underwent CRF of the nervus females to the trochanter. CRF procedures were either targeted at the left, right, or bilateral nerves.

Conclusion

This case series provides additional evidence for the safety and effectiveness of CRF of the nervus femoralis to the trochanter for offering long-term pain relief in patients with GTPS. All patients experienced at least two months of relief, with most patients experiencing ongoing relief from the procedure.

Posterior hip pericapsular neurolysis (PHPN) for inoperable hip fracture: an adjunct to anterior hip pericapsular neurolysis

BACKGROUND

The development of anterior hip neurolysis has made an appreciable impact on the management of patients with inoperable hip fracture. Nonetheless, suboptimal analgesic benefit was still observed in some patients. We therefore developed a novel posterior hip pericapsular neurolysis (PHPN) to complement anterior hip neurolysis in inoperable hip fracture.

METHODS

In this retrospective review, we analyzed patients who responded suboptimally (defined as composite pain score moderate or higher on hip flexion 80°) to the anterior hip neurolysis from July 2019 to March 2021. The patients received additional PHPN if the composite pain score was suboptimal. The percentage of patients with dynamic composite pain scores on hip flexion to 80° and on gentle hip external and internal rotation on post-intervention day 5 was then evaluated.

RESULTS

Among the 70 patients who were reviewed in the study period, 20 patients who partially responded to anterior hip neurolysis received an addition of diagnostic posterior hip pericapsular block. Eighteen patients were the positive responders and PHPN was then performed. Among the PHPN recipients, a high percentage with satisfactory dynamic pain control was observed with 78% on hip flexion 80° and 83% on hip external/internal rotation on day 5 following the intervention. No procedural adverse event was noted.

CONCLUSIONS

While most patients responded satisfactorily to anterior hip neurolysis, we concluded PHPN could be an effective adjunct to manage suboptimal pain control after anterior hip neurolysis in inoperable hip fracture.

TRIAL REGISTRATION NUMBER

NTWC/REC/21061.