Background: Hip fractures in the elderly are linked to high morbidity and mortality. Pain control is crucial for improving outcomes, and traditional treatments include paracetamol and opiates. Fascia Iliaca Compartment Block (FICB) is a promising alternative that provides effective analgesia with minimal complications.

Aims: This review aimed to evaluate the efficacy and safety of FICB, as well as its potential to reduce opioid use and the incidence of delirium in hip fracture patients.

Methods: A comprehensive search of Cochrane, Medline, PubMed, and Embase identified relevant studies on FICB in hip fracture patients.

Results: Ten studies, including six randomized controlled trials, three non-randomized studies, and one observational study, were analyzed with 1,520 patients. Seven studies reported significant pain relief after FICB. Six of eight studies found a reduction in opioid consumption, with no complications noted. Results on delirium reduction were inconsistent.

Conclusion: FICB is a safe and effective pain management option for hip fracture patients, offering comparable or superior analgesia to opioids and NSAIDs. It reduces the need for additional analgesics, thus minimizing side effects. The effect of FICB on delirium remains unclear and warrants further research.

Abbreviations: FICB: Fascia-iliaca Compartment Block; LA: Local anaesthetic; RCT: Randomized control study; ED: Emergency department; IM: Intramuscular; IV: Intravenous; LOS: Length of stay; NSAID: Non-steroidal anti-inflammatory drug; NRS: Numerical rating score; PO: Per Oral; SPA: Standard Preoparative analgesia; US: Ultrasound; VAS: Visual Analogue Score

The worldwide population age is steadily increasing and, with it, an increase in the number of hip fractures. Hip fractures are considered a global epidemic in several countries [1]. Research by Cooper et al. [2] projected that the number of global hip fractures would increase from 1.66 million in 1990 to 6.26 million by 2050. The increase in hip fractures with age can be accredited to a decrease in bone mineral mass and an increased risk of falls in the elderly. The incidence of hip fractures is around twice as common in women as in men, with mechanical falls being the most common cause [3]. Hip fractures are associated with high mortality and morbidity rates, including disability and institutionalization [4].  

Adequate pain control is an essential component of hip fracture management. Suboptimal pain control is associated with worse outcomes and increased complications [5]. Historically, patients were given analgesia in the form of a combination of paracetamol, weak opioids and morphine. More recently, regional nerve blocks have emerged as an effective adjunct to traditional methods [5]. The National Institute for Health and Care Excellence (NICE) also recommends the use of nerve blocks to improve patient outcomes.  (6) Fascia Iliaca compartment block (FICB) is a more commonly used regional block technique and was first described by Dalens et al. (7) in 1989. FICB involves administering a large volume of dilute local anaesthetic (LA) into the fascia iliaca compartment, thereby theoretically anaesthetising the femoral, obturator, lateral cutaneous and genitofemoral nerves as well as other elements of the lumbar plexus, as the anaesthetic tracks caudally. Dalens et al. (7) demonstrated that FICB produced a more effective sensory blockade with no complications reported.

FICB has several advantages over other regional blocks and systemic analgesia; the procedure can be performed with ease using the “two-pop” technique or under ultrasound guidance and is safe with no absolute contraindications to be noted. Clotting disorders, allergy to LA, local infection and an un-cooperative patient are relative contraindications [7,8]. Despite the apparent benefits of FICB, its application is still not prevalent.

The scope of this review is to provide an overview of the literature and compare the use of FICB in hip fracture patients with that of conventional analgesia by answering the question “In adult patients (>18 years) with femoral neck fractures, does the administration of a preoperative FICB provide an effective and safe means of analgesia when compared to conventional analgesia?”

The aims of this review were to assess the analgesic efficacy of a preoperative FICB in adult patients with hip fractures, to determine whether FICB is a safe mode of analgesia and to investigate whether FICB can decrease the consumption of conventional analgesia such as opiates and the complications associated with them.

Review Registration
This systematic review was registered on the international prospective register of systematic reviews, PROSPERO with registration number CRD42021232877.

Data Sources and Search Strategy
Between December 2020 and February 2021, a comprehensive search for eligible studies was conducted across electronic databases, including COCHRANE, PubMed, Embase, and Medline. The search strategy, based on PICO components, utilized free-text terms, keywords, MeSH terms, and Boolean operators to identify relevant studies. References of selected studies were also screened for eligibility. To minimize bias, the search strategy and results were reviewed and validated by a second reviewer.

Inclusion and Exclusion Criteria
Study selection followed specific inclusion and exclusion criteria, focusing on randomized controlled trials (RCTs), quasi-RCTs (q-RCTs), and observational studies comparing the analgesic efficacy of preoperatively administered FICB to traditional analgesia in adults with isolated hip fractures. Various study designs were included due to an overall lack of available research. Eligible studies were written in English with accessible full texts, and no date restrictions were applied due to the expected scarcity of relevant literature. Traditional analgesia included commonly used methods such as paracetamol, NSAIDs, mild opiates, and morphine, excluding other nerve or regional blocks.

Primary and Secondary Outcomes
The primary outcome for this review was pain relief, as measured by a pain measurement tool, after administration of FICB in adult patients with an isolated hip fracture. Secondary outcomes for this review included the incidence of any adverse effects from FICB administration, additional analgesia consumption, particularly opioids, and incidence of delirium.

Data Collection, Screening and Management
A thorough search for eligible studies was conducted following the established search strategy and inclusion/exclusion criteria. The primary reviewer initially performed the search independently, followed by collaboration with a second reviewer. There were no discrepancies so a third reviewer was not necessary. Titles and abstracts were screened for eligibility, and relevant study details, including PICO components, were documented in a custom Microsoft Excel sheet for data management. Excluded studies and reasons for exclusion were recorded, and duplicates were marked. For unclear cases, full texts were accessed and reviewed. A librarian assisted in obtaining inaccessible full texts. The process is summarized in a PRISMA(9) flow diagram (figure 1).

Data Analysis and Quality Assessment
The data extracted from the included studies was evidently highly heterogeneous. Thus, this data did not lend itself to meta-analysis and a narrative analysis was performed. Quality appraisal of the included studies was guided by the Critical Appraisal Skills Programme (CASP) Tool(10) for both the RCTs and Non-RCTs.

Risk of Bias
The Cochrane risk-of-bias tool for randomised trials (RoB2)[11] was used to assess risk of bias for RCTs while the ROBINS-I [12] tool was used to assess for bias in Non-randomised RCTs, as recommended by the Cochrane Handbook of Systematic Reviews for interventions.

Study Selection
The search identified 174 potentially eligible studies across four databases. After removing 49 duplicates, 125 studies remained. Screening of titles and abstracts excluded 98 ineligible studies. The full texts of the remaining 27 studies (11 from Cochrane, 7 each from Embase and PubMed, and 2 from references) were reviewed, resulting in 10 eligible studies included in the review. Reasons for exclusion included inaccessible full texts (n=6), inappropriate primary outcomes (n=6), absence of a control group (n=3), and incorrect study design (n=2). The process is summarized in figure 1.

Study Characteristics
This review included ten studies published between 2007 and 2020: six RCTs, three non-RCTs, and one observational study. Study populations ranged from 30 to 725 participants, with most dividing intervention and control groups equally, except for one study by Garlich et al. [13], which used a larger historical control group. All studies compared FICB to other analgesia forms, with variations in the type and dose of local anesthetics (bupivacaine, levobupivacaine, and ropivacaine in three studies each, and mepivacaine in one study). Seven studies [14–20] administered a single-dose FICB, tw [21,22] used continuous infusion via a catheter, and one [13] utilized both methods based on the physician's discretion.

Blocks were administered by trained physicians, except in one [14] study where it was unspecified. Single-shot FICB used a landmark technique, while catheter-based methods employed ultrasound guidance. Pain relief was the primary outcome in all studies, measured using respective pain scores. Secondary outcomes varied, and accessory analgesia was reported in all but one [14] study. Study characteristics are detailed in Table 1.

Risk of Bias
All ten [13–22] studies were well-structured and were all deemed to have minimal risk of bias [11,12]. Assessments for risk of bias of RCTs (Table 2) and non-RCTs (Table 3) were performed and included in this review, highlighting the reasons for bias.

Four (14,15,19,20) of the six (14,15,19–22) included RCTs were double-blind trials, however, lack of blinding was observed to be a source of bias. This may have been due to the fact that the administration of an FICB is a rather conspicuous procedure, clearly differing from more traditional analgesia such as IV or oral treatment. Additionally, the administration of a placebo FICB raised some ethical concerns so its omission contributed to lack of blinding (21).

Contrary to RCTs, prospective non-RCTs were more susceptible to the Hawthorne effect as both patients and personnel were aware of the intervention. This was highlighted by the considerable level of bias in measurement of outcomes observed in three(13,17,18) of the four non-RCTs included.

Quality assessment of RCTs
Five (14,15,19–21) of the six RCTs addressed clearly focused questions with detailed PICO components, while Hao et al. (22) misrepresented PICO elements by suggesting post-operative delirium was the primary outcome instead of pain relief. Randomization methods were adequate in all six studies, with study groups starting similarly and receiving consistent care. Participant blinding was implemented in all studies except Ma et al. (21), who omitted blinding for ethical reasons, potentially introducing bias. Blinding of personnel was unclear in two studies, raising concerns about possible bias.

All participants were accounted for at study conclusions, except for Hao et al. (22), where two patients were lost to follow-up due to catheter dislodgement. Treatment effects were precisely reported in three studies, and adverse effects were addressed in all but one (Pasquier et al. (19)). Despite these limitations, intervention effects were comprehensively reported in all studies.

Quality Assessment of Non-RCTs
The four non-RCT studies addressed clearly focused questions with detailed PICO components. Three(16–18) studies recruited participants prospectively and measured exposures accurately to minimize bias. In contrast, Garlich et al.(13) compared a historical cohort receiving conventional analgesia to a prospective cohort receiving FICB, potentially influencing participant recruitment and outcome assessment. Bias due to confounding was minimal in all studies, but inadequate documentation of pre-intervention medications and their impact on pain scores was a notable limitation. Three studies were comparable to well-performed RCTs, while Garlich et al.(13) provided strong evidence for evaluating FICB but fell short of RCT comparability.

Primary outcome
Seven studies (14–18,21,22) showed statistically significant reductions in pain scores after administration of an FICB. The study by Wennberg et al. (20) demonstrated significant reductions in pain scores in the FICB group but, after correcting for an imbalance in baseline pain scores, these differences were not retained. Two studies (13,19) did not demonstrate any significant difference in pain scores between intervention and control groups.

Seven(14–20) studies analysed the effects of a single-shot FICB. Of these, five(14–18) exhibited improved pain outcomes which were statistically significant while two(19,20) did not. Conversely, two studies(21,22) followed up the single-shot FICB with a continuous infusion of LA via a catheter. Ma et al.(21) showed statistically significant reductions in pain scores one hour after analgesia, both at rest and on passive movement. Hao et al.(22) also demonstrated significant reductions in pain scores in the first four hours after administration, persisting up until the time of anaesthesia. In their study, Garlich et al.(13) administered a single-shot FICB or an FICB plus an infusion of LA. They did not specify what proportion of patients received either of the two aforementioned options. Nonetheless, they reported no statistically significant differences in pain scores between the intervention and control groups.

Pain at rest was assessed in nine studies(13–15,17–22). Although four studies(13,14,18,22) did not explicitly specify if pain scores were taken at rest, there was no reason to assume otherwise. Only two studies(15,21) provided separate data for pain at rest and on movement. Foss et al.(15) noted a statistically significant improvement in VAS at rest at 60 (p=<0.01) and 180 (p=0.03) minutes and a significant improvement in VAS on movement at 180 minutes. Ma et al. (21) Had similar findings with significant reductions in pain scores at rest (p=0.023) and on passive movement (p=<0.05) at 60 minutes from block.

Timing of pain score assessment was a significant variable. All the included studies assessed pain scores within one hour of block administration. One study(13) only provided an average preoperative pain score despite taking measurements every 4-6 hours. Pain during the first hour after FICB administration was significantly reduced in four studies(14,15,18,21). Beyond the first hour, results varied. Foss et al.(15) demonstrated a significant reduction in pain score at three hours. Both studies by Hanna et al.(16) and Williams et al.(17) found significant reductions in pain scores between two and eight hours after the block was given with Kassam et al.(18) noting reduced pain scores at six and 12 hours. Conversely, despite noting lower pain scores after 15 minutes, Monzon et al.(14) did not observe any significantly reduced pain scores between two and eight hours. Only two studies(16,19) assessed the effect of FICB beyond 12 hours and neither reported significant reductions in pain scores.

Two studies(14,19) compared the efficacy of FICB to regular intravenous (IV) or oral NSAIDs respectively. In both instances, there was no significant difference in pain between the two groups other than a reduction in pain score at 15 minutes seen in the study by Monzon et al.(14).

Secondary outcomes
Eight studies assessed additional analgesia requirements. Six of these(13,15–18,22) demonstrated statistically significant (p=<0.05) reductions in additional analgesic requirements which were universally opiates. In the study by Foss et al.(15), no additional morphine was given to the FICB group whereas a median of 6mg of morphine was given to the control group (p=0.01). Pasquier et al.(19) observed no differences in additional morphine consumption between FICB and control groups with an average of 7mg and 8mg respectively (p=0.63). Findings were similar for Wennberg et al.(20) with no significant differences in additional morphine consumption at two (p=0.36) or six hours (p=0.37).

Seven studies(14–18,21,22) reported on the safety profile of FICB and no serious complications were reported. Foss et al.(15) reported that the control group were more sedated and had a tendency towards lower oxygen saturation. Monzon et al(14) noted four instances of delirium in the IV NSAID group whereas no episodes occurred in the FICB group. The incidence of opioid overdose was assessed in one study(17) whereby the control group receiving standard care showed a significantly more frequent occurrence (7.2% vs 0%; p=0.001). One study(13) could not find any statistical difference in opioid related side effects between the two groups.

Only two studies assessed the incidence of delirium, with conflicting results. Hao et al.(22) report a significantly decreased incidence of post-operative delirium in the FICB group (13.9% vs 35.7%; p=0.018) whereas Garlich et al.(13) could not demonstrate a significant difference in the incidence of delirium between the two groups. A summary of the outcomes of each study is provided in table 4.

Pain Relief
Hip fractures are highly painful injuries, and the most effective analgesia is surgical repair and fixation, ideally performed within 48 hours, as this reduces 1-year mortality by 20% (Klestil et al.)(23). Optimal recovery requires both timely surgery and adequate pain management from the emergency room until the procedure. The NICE guidelines recommend using nerve blocks alongside paracetamol and opioids for additional pain relief while reducing opioid-related side effects. However, the guidelines do not specify which nerve block technique to use, leading to variability in block characteristics (e.g., drug type, dosage, single-shot vs. continuous infusion) and pain assessment timing. This lack of specificity reflects the absence of a clear consensus in the literature on the best method.

Studies(21,22) on continuous infusion of local anesthetics (LA) for pain relief after hip fractures lacked data beyond four hours, making it unclear if this method offers benefits over single-shot FICB. In contrast, studies(17,18) on single-shot FICB demonstrated improved pain scores at 8 and 12 hours, with one study(16) reporting reduced pain scores at 16 and 24 hours, though not statistically significant. These findings suggest that a single-shot FICB with a long-acting LA may provide effective analgesia lasting up to 12 hours.

FICB was directly compared to several regimens of opioids namely, morphine(15), tramadol(21) and fentanyl(22). In all instances, significant improvement in pain was observed in the FICB groups, both at rest and on movement, suggesting that FICB may provide superior analgesia to opioids. FICB was also compared to NSAIDs in one study by Monzon et al.(14). They demonstrated that FICB provided more effective analgesia within the first 15 minutes but between 2-8 hours, pain relief was similar in the FICB group to the IV NSAID group. This data suggests that FICB is similarly effective at providing pain relief in hip fractures as NSAIDs, however, the adverse effects of NSAIDs, including an increased risk of fracture(24), are well documented in the literature and thus, FICB may be a more appealing approach.

Of note, none of the included studies referred to any non-pharmacological means of analgesia, such as traction or urinary catheterisation (to decrease need for mobilisation) that may or may not have been used and this may have caused some bias. These findings are in keeping with several other systematic reviews in the literature by Steenberg et al(25)., Wan et al.(26), and Pinson et al.(8)

Minimisation of opioid consumption
Despite their several side-effects, opioids remain the mainstay of pain management in hip fracture patients. Indeed, the eight studies (13,14,16–20,22) in this review assessing additional analgesia requirements all measured opioid consumption. In the elderly, physiological changes such as increased adipose tissue can lead to delayed elimination of drugs, including opioids, and thus their adverse effects can be exaggerated (27).

At least four other reviews(5,25,26,28) have reported that FICB significantly reduced the need for additional opioid administration. This is in keeping with the findings of this review where six(13,15–18,22) out of eight studies reported decreased opioid requirements. Contrarywise, Pasquier et al.(19) noted that total morphine consumption was similar in both intervention and control groups but one should note that both groups received only small doses of morphine and that all patients were given regular doses of acetaminophen. Wennberg et al.(20) did not find a significant difference in morphine consumption although they administered a low dose of ropivacaine in their blocks which may have affected their results. Although the studies in this review each have their own limitations, the data is very compelling and serves a strong indicator that FICB is very effective in minimising additional opioid consumption as well as any resultant complications.

Incidence of Delirium
Delirium is a common complication in elderly hip fracture patients, particularly after surgery. Major risk factors include prior cognitive impairment, male gender, advanced age, and morphine usage, with morphine increasing the risk of delirium by over threefold according to a systematic review by Yang et al.(29), though the data showed significant variability. Cognitive screening has been suggested as part of standard care for these patients. The impact of FICB on delirium is unclear, with one study(29) showing reduced delirium incidence while another(13) did not, potentially due to differences in patient selection (e.g., inclusion of patients with dementia). Regardless, patients with dementia should still receive appropriate analgesia, including FICB, if deemed effective.

Safety and adverse effects of FICB
The safety of FICB has been widely documented throughout the literature and it is universally regarded as a safe procedure(14,16,17,26). This review has corroborated this as none of the included studies reported any serious adverse outcomes. Of note, the personnel administering the block ranged from regional anaesthesia team members to junior anaesthetists with basic training. The wide variety of staff performing blocks indicates that FICB is a simple and safe procedure that may be administered with minimal training and sparse complications. Conversely, one could speculate that FICB may be more effective if administered by anaesthetists rather than junior staff.

This review demonstrates that FICB provides similar, and sometimes superior, pain relief for hip fractures compared to traditional systemic analgesia, without serious adverse outcomes. FICB is best used as part of a tailored pain management plan rather than in isolation. A key benefit of FICB is its ability to reduce opioid consumption, which is beneficial for patient outcomes and mortality. FICB is a safe, easy-to-perform procedure that can be quickly administered in emergency settings with readily available equipment. It offers comparable or superior analgesia to opioids and NSAIDs, with a better safety profile. Moreover, FICB reduces the need for additional analgesia, thereby minimizing drug-related side effects. Although the role of FICB in reducing delirium remains unclear, its potential benefit, particularly by reducing opioid use, is promising. Future research should focus on standardized treatment protocols and randomized controlled trials (RCTs) to compare single-shot versus continuous FICB for longer-lasting pain relief.