What’s New in Hip Surgery

The trend of high-quality publications exploring the orthopaedic management of hip pathology has continued since the last iteration of this Guest Editorial. Common themes of this update include preoperative and perioperative management in total hip arthroplasty (THA), perioperative pain control, and emerging technologies. It is imperative that today's hip surgeon remain knowledgeable about these rapidly expanding topics. Preoperative Considerations in THA Punnoose et al. published the results of a systematic review and meta-analysis involving 48 trials (3,570 patients) comparing prehabilitation with standard preoperative care in adults undergoing orthopaedic procedures1. Pain, muscle strength, function, health-related quality of life, and disease-specific and/or joint-specific outcomes were assessed for THA (among other orthopaedic procedures). In the preoperative setting, there was moderate-certainty evidence favoring prehabilitation in THA over standard care for the outcomes of hip abductor strength and health-related quality of life. In addition, there was low-certainty evidence favoring prehabilitation over standard care for the outcomes of pain and function. At 3 and 12 months postoperatively, there was low-certainty evidence favoring prehabilitation over standard care in THA, with a smaller benefit for patients undergoing THA compared with total knee arthroplasty (TKA). Similarly, in a recent article, Adebero et al. analyzed 28 trials to assess the effectiveness of prehabilitation on outcomes following THA2. Pain, health-related quality of life, strength, range of motion, and function were all significantly improved in patients receiving prehabilitation prior to TKA. In contrast, the trials addressing THA were limited and contradictory. Evidently, prehabilitation may have some role in improving the preoperative status of patients who will undergo THA, whereas the postoperative benefits are less substantial. Prehabilitation may be more useful in patients who undergo TKA than in those who undergo THA based on current evidence, with a potential, but limited, benefit in THA. Perioperative Management Postoperative drainage after hip and knee replacement can be problematic for patients and surgeons. In their secondary analysis of their Australian Orthopaedic Association National Joint Replacement Registry-based study, Sidhu et al.3 examined whether enoxaparin compared with aspirin was associated with increased postoperative wound drainage. In the cluster-randomized, crossover, noninferiority, nested registry trial (CRISTAL4), 31 institutions across Australia examined the prevalence of deep vein thrombosis in patients. Sidhu et al. took the results from 2 of the high-volume centers participating in this trial and examined them for wound complications. The included patients received 100-mg aspirin or 40-mg enoxaparin daily for 35 days after hip replacement and for 14 days after knee replacement. They found that overall persistent wound drainage did not differ (p = 0.40) between groups: 8% for the aspirin group and 9% for the enoxaparin group (odds ratio [OR], 1.2). However, in those patients who underwent a subcuticular closure, persistent wound drainage was observed in 7.7% of patients taking enoxaparin and 2.4% of patients taking aspirin (OR, 3.6; p = 0.009). This difference was not observed in those patients who underwent skin staple closure, and there was no difference in reoperations. The authors did advise caution when interpreting these results given the small sample size and the presence of effect modification by the thromboprophylaxis agent and type of wound closure, which prevented full model analysis. Intraoperative hemostasis remains a topic of discussion. Tranexamic acid (TXA) is widely adopted as a perioperative agent utilized to decrease perioperative blood loss in major orthopaedic operations. In a Cochrane Review, Gibbs et al. aimed to determine which of the commonly utilized perioperative agents (intravenous or oral TXA and recombinant factor VIIa) used in blood loss prevention were effective at reducing bleeding in patients requiring definitive fixation for hip, pelvic, and long-bone fractures5. The authors found that intravenous administration of TXA compared with placebo may reduce the risk of requiring allogenic blood products for 30 days postoperatively (risk ratio [RR], 0.48 [95% confidence interval (CI), 0.34 to 0.69]; 6 randomized controlled trials [RCTs], 457 participants), but with a low degree of certainty due to statistical imprecision. Additionally, the authors were uncertain if topical TXA compared with placebo resulted in fewer transfusions or less all-cause mortality, and they could not analyze factor VIIa because of a lack of evidence. The risk assessment tools for the development of deep vein thrombosis and pulmonary embolism are of particular use to the arthroplasty community. The Caprini score is a commonly used tool to predict the risk of the subsequent development of deep vein thrombosis or pulmonary embolism after a surgical intervention. Arthroplasties themselves automatically result in a patient score that is a minimum of 5 on this scale, and, as such, the effectiveness of this scale as a predictive tool in this population has been questioned. Qiao et al. aimed to answer this question via their study of 7 years of data on venous thromboembolism6. In their study, the authors included 3,807 patients who had undergone preoperative and postoperative ultrasonography on postoperative days 3 to 5, making it the largest study to date. The authors found a strong correlation between a greater Caprini score and venous thromboembolism (r = −0.775; p = 0.003); however, they noted that the receiver operating characteristic (ROC) curve had a poor area under the curve (AUC) of 0.619, confirming that the Caprini score is not prognostic. They determined that a Caprini score of ≥8.5 suggested a high risk of venous thromboembolism and recommended appropriate prophylaxis for high-risk patients. However, it is worth noting that the Youden index associated with their chosen cutoff was 0.175, which indicates only a modest level of effectiveness for a diagnostic test. In addition, 92.4% of the deep vein thromboses were located below the knee and were "muscular," which has debatable clinical importance. The authors confirmed a strong correlation; however, the precise cutoff value for an increased regimen of thromboprophylaxis in the population undergoing arthroplasty remains debated. As the lower-extremity ultrasound scan was performed on postoperative days 3 to 5 and not beyond, deep vein thrombotic events occurring after this would have been missed, which limited the interpretation of the results. Perioperative Pain Control Nerve Blockade There have been numerous high-quality studies recently published on pain control in the perioperative period. Bravo et al. conducted an RCT comparing a pericapsular nerve group block with periarticular anesthetic infiltration after spinal anesthesia7 and found no difference in terms of the quadriceps motor blockade at any time point postoperatively. This was unexpected and was thought to be due to the questionable power of the study to adequately detect the difference and the multifactorial nature of quadriceps weakness in the postoperative period. The periarticular anesthetic infiltration resulted in lower static pain scores at all time intervals postoperatively (range of visual analog scale [VAS] difference, 0 to 2), in addition to lower dynamic pain scores (with adduction) at 3 and 6 hours (VAS difference, 2). There were no differences in opioid requirements in the postoperative period. The authors concluded that the increased success of the periarticular anesthetic infiltration block was due to its coverage of the posterior tissues, which was deficient in the pericapsular nerve group block. Alternatively, some researchers are considering quadratus lumborum blockage as a pain control strategy. Takeda et al.8 compared quadratus lumborum blockage with femoral nerve blockage in their RCT and found no significant difference in cumulative morphine consumption (p = 0.72) or intraoperative morphine consumption (p = 0.26). The authors could not show a clear superiority of quadratus lumborum blockage over femoral nerve blockage with respect to postoperative strength or fall risk. There was a debate in a subsequent letter to the editor regarding concerns over the sample size for that study9. In their RCT, Umeh et al.10 examined quadratus lumborum blockage compared with periarticular anesthetic infiltration in the population undergoing hip arthroscopy but did not find any differences in postoperative opioid consumption (p > 0.05) or a difference in postoperative quadriceps weakness (p = 0.2). As the baseline pain after THA tends to be low and variable, the concern regarding the above studies is that they would be underpowered to detect minor differences in analgesic effect. Oral Pain Medication Oral analgesia to decrease opioid consumption after joint replacement is an attractive adjuvant. Duloxetine has been classified as a selective serotonin and norepinephrine reuptake inhibitor (SSNRI) and has been previously investigated for its action after joint replacement. Azimi et al.11 investigated its postoperative role in their systematic review and meta-analysis of the current high-level evidence. After including 9 Level-I RCTs, the authors determined a significant and moderate decrease in oral morphine milligram equivalents and a lower overall pain level at several time points; however, they called into question the clinical importance of the latter, given that the reduction did not meet the minimal clinically important difference. There was also significant heterogeneity in the results, creating a low certainty of evidence. The authors concluded that the use of duloxetine may reduce the intensity of pain; however, they also concluded that "the current evidence does not support routine use for the sole purpose of reducing post-operative pain" and that its potential opioid-sparing effects must be weighed against the side effects. Meanwhile, in their RCT, Shen et al.12 assessed the impact of TXA on opioid use by comparing oral administration with intravenous administration. The authors enrolled 161 patients and assessed pain in the first 3 days via a VAS score and postoperative tramadol consumption. They also measured C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and interleukin-6 (IL-6) daily for the first 3 days, as inflammatory markers. They found that topical TXA appeared to yield a lower VAS score, as well as lower CRP, ESR, and IL-6 measurements. The results should be interpreted with caution, however, as the differences in the VAS score, CRP, ESR, and IL-6 were minimal, which questions their clinical importance. In addition, preoperative levels were not measured, and spinal anesthesia compared with general anesthesia did not appear to be controlled for. It is plausible that topical TXA may reduce hematoma formation, which, in turn, may decrease postoperative pain and may reduce inflammatory markers; however, more research is required to answer this interesting question. Hip Fracture Management Displaced Femoral Neck Fracture In a recent study by Lynch Wong et al., the rates of postoperative periprosthetic femoral fractures after THA with cemented polished taper-slip stems (0.9%) were higher than with cementless stems (0.7%)13. Of note in this study, male patients with a polished tapered femoral component were 5 times more likely to have a reoperation for postoperative periprosthetic femoral fracture compared with male patients with a cementless stem. The concerns around postoperative periprosthetic femoral fractures with these stems are relatively new and should be monitored closely in future studies, particularly in international registry reports, as categorization by THA versus open reduction and internal fixation (ORIF) may mask the identification of cases. In a recent systematic review and network meta-analysis of 5,703 displaced and nondisplaced femoral neck fractures, Ramadanov et al. demonstrated a superior functional outcome (EuroQol-5 Dimensions [EQ-5D] and Harris hip scores) for both hemiarthroplasty and THA14. The reoperation rate was highest for cannulated screws (9.98 times higher), followed by a dynamic hip screw (5.07 times higher). There was no difference in reoperation rate between hemiarthroplasty and THA. This analysis did not discriminate between displaced and nondisplaced femoral neck fractures and, as such, more focused research is required. However, these results potentially support the use of arthroplasty for all femoral neck fractures, regardless of displacement. Nondisplaced Femoral Neck Fracture Adding to the literature on management of nondisplaced femoral neck fractures, Sattari et al. reported on their results comparing internal fixation and hemiarthroplasty for the management of Garden type-I and II (nondisplaced) femoral neck fractures15. The 6-month Harris hip score (p = 0.009) and the 1-year EQ-5D (p = 0.04) were significantly better in the hemiarthroplasty group. Internal fixation, compared with hemiarthroplasty, also had a higher rate of implant-related complications (20.1% compared with 6.0%; p = 0.0002) and reoperations (20.1% compared with 6.0%; p = 0.0001). Hemiarthroplasty for nondisplaced femoral neck fractures had disadvantages with regard to blood loss and operative duration. Perioperative Interventions in Hip Fracture Management Perioperative optimization is critical in the hip fracture setting. Several recent systematic reviews have focused on this area of clinical interest for this particularly fragile patient cohort. Lewis et al. summarized the evidence from Cochrane Reviews and other systematic reviews of randomized or quasi-randomized trials to assess the perioperative interventions that may lead to reduced blood loss, rates of anemia, and need for blood transfusion in patients with a hip fracture16. This Cochrane Review included results from 36 RCTs involving 3,923 participants. The 2 interventions of interest were TXA and iron. TXA It was determined that TXA, given topically or intravenously, likely reduced the number of patients requiring transfusion by 194 per 1,000. The risk profile of TXA administration was assessed and was found to be minimal to none with regard to deep vein thrombosis (RR, 1.16; 22 studies), pulmonary embolism (RR, 1.01; 9 studies), myocardial infarction (RR, 1.00; 8 studies), stroke (RR, 1.45; 8 studies), or death (RR, 1.01; 10 studies). Iron Based on 2 studies with 403 participants, there was deemed to be little to no difference in outcomes when iron was administered in the perioperative period. The risks of negative outcomes such as transfusion (RR, 0.90), infection (RR, 0.99), and 30-day mortality (RR, 1.06) were similar when intravenous iron was administered compared with when it was not. However, because the iron results were based on only 2 studies, the ability to draw any meaningful conclusions was limited. Postoperative Interventions in Hip Fracture Management Phang et al. reviewed 109 RCTs involving an array of postoperative interventions in patients >65 years of age who sustained a non-pathological hip fracture in which surgical management was adopted17. The following 10 broad categories of intervention were considered: (1) rehabilitation; (2) medication, nutrition, and supplementation; (3) optimization of clinical management; (4) prevention of venous thromboembolism; (5) a multidisciplinary program; (6) osteoporosis or fracture prevention; (7) fall prevention; (8) prevention of postoperative anemia; (9) supported discharge; and (10) other. Each of these categories was further divided into 3 subgroups based on whether the intervention occurred on an inpatient basis, an outpatient basis, or both. The interventions for which only positive outcomes were reported are listed, by category, in Table I. TABLE I - Interventions with Exclusively Positive Outcomes, by Category of Intervention Intervention Inpatient Outpatient Inpatient and Outpatient Rehabilitation Aerobic trainingSpecialized physical rehabilitationWeight-bearing exerciseTreadmill trainingTranscutaneous electrical nerve stimulationSpecialized geriatric rehabilitationProgressive high-intensity trainingIntensive physiotherapyNeurostimulationIndividualized occupational therapyBalance task-specific trainingEarly ambulation Resistance trainingStrength trainingPhysical training and self-efficacyHome physiotherapySelf-efficacy-based exerciseTelerehabilitationWeight-bearing exercise Extended physical therapyIndividualized occupational therapyWeight-bearingCognitive behavioral therapyAccelerated rehabilitation Medication, nutrition, and supplementation Nutritional supportDietetic assistantsGrowth hormoneEssential amino acid supplementationVitamin D Essential amino acid supplementationVitamin D Nutritional support with dietetic counselingBone anabolic drugVitamin D and calciumAnabolic corticosteroidsIntranasal calcitonin Optimizing clinical management Physiotherapy educationManagement of painManagement of postoperative delirium None None Prevention of venous thromboembolism None None Fondaparinux sodiumAntithrombotic agent Multidisciplinary program Orthopaedic and geriatric care Multidisciplinary Intensive geriatric rehabilitationEarly discharge supported by geriatric interdisciplinary team Osteoporosis or fracture prevention None None Primary care and patient empowermentVitamin D and/or calciumOsteoporosis management Fall prevention Multicomponent cognitive behavioral interventionMultidisciplinary care Follow-up call Home assessment visit pre-discharge Postoperative anemia None None None Supported discharge None None Gerontologic advanced practice nurse care Other None Group learning and exerciseMotivational interviewing None Hip Preservation Systematic reviews and meta-analyses have been the focus of several recent hip preservation-themed studies. In their systematic review of mid-term outcomes of labral reconstruction, Curley et al.18 found that there was a trend of improved patient-reported outcomes in all included studies. However, there was significant heterogeneity with respect to approach, reconstruction indications, and allograft choice, which precluded a pooled analysis. The authors also acknowledged that the inclusion of Level-III and IV studies introduced bias to the overall results. Labral reconstruction may offer durable results in carefully chosen patient populations, but the optimal approach could not be determined. Although more commonly studied in knees, Dhillon et al.19 examined how microfracture for chondral defects compared with other cartilage repair methods in the management of femoral acetabular impingement. Six studies were included, all with low levels of evidence. In addition, there was a heterogeneous group of comparative cartilage procedures and lesion sizes. All included studies had moderate bias with respect to confounding and severe bias with respect to measurement of the outcome. Although they concluded that microfracture was not inferior to other methods with respect to patient-reported outcomes, the authors emphasized that the available literature was limited in its ability to address the research question. With regard to capsular repair, Kaplan et al.20 also conducted a systematic review to determine how the management of the hip capsule during hip arthroscopy for femoral acetabular impingement influences patient-reported outcome measures or re-revision surgery. The 4 included studies all represented Level-III evidence, and a pooled analysis was not possible given their heterogeneity. The authors found similar patient-reported outcome measures in the capsular repair group compared with the group that did not undergo capsular repair. The authors also found that an unrepaired capsule appeared to yield greater rates of re-revision hip arthroscopies (range, 15.4% to 25.5%) compared with a repaired capsule (range, 3.1% to 15.4%). However, the authors suggested that this result should be interpreted with caution, given the degree of heterogeneity and bias within the included studies that may have led to confounding and spurious results. Periprosthetic Joint Infection (PJI) There has been considerable on the of prior to and the results have been answer this et performed a meta-analysis of the available They included 28 on hip and knee of which were Level-III and IV evidence, for 2 studies. There were patients pooled from the population undergoing hip The authors found an overall rate of in the group and in the control group (p = to an increased risk of infection was not found in the population undergoing knee The authors also found that a within 3 months prior to hip or knee arthroplasty increased the risk of infection compared with p = [95% to However, the authors that the results should be interpreted with caution given the lack of and heterogeneity in the included studies, and they suggested that the current of literature could not adequately answer this question. They recommended caution on the of with respect to but called for evidence to adequately address this question. address and an RCT by et al. examined whether the infection rate after hemiarthroplasty compared with at In their superiority patients were enrolled to or of and The authors found an infection rate of for the group and for the group. After their model was they found a risk difference for deep surgical infection in the standard group of to and an of to p = when compared with the group. these results with studies on the however, this study has the largest sample In a study for in THA, et al. conducted a controlled study comparing intravenous administration prior to skin with of in of into the greater at the time of skin They noted when patients were given via there was a significant reduction in all and and acetabular had higher levels of in the group compared with the intravenous however, only the levels in the acetabular a significant difference. The study was not to if this resulted in a clinically infection risk. and in THA The of is the in recent orthopaedic because of its of complications to As a has the use of femoral in a positive impact on hip et al. published results from in which were At a range of to did not and there was no clinically importance difference in between those patients who required a reoperation or any and those who did not. In some the was as as The of the ability to use femoral which, in turn, the and hip et al. also published the results of femoral within a acetabular component or They reported at mid-term and rates were all In a network et al. demonstrated that of or had a and all of them were superior to This study confirmed higher rates for and on compared with and on There were smaller and inferior Harris hip scores when or on were used compared with all other In femoral and acetabular are the standard of care in THA. Femoral The of fixation of the femoral in THA can between cemented and stems include the polished taper-slip and In a recent RCT, et al. analyzed polished taper-slip cemented femoral of which were to a group and were to a outcomes were deemed between the 2 outcomes were also and the in the group with the was reported to be in greater compared with the group. of femoral that may to stems is femoral ratio by et al. the impact that a low greater can have in femoral With a femoral ratio of the risk of can be as high as The risks of include femoral et al. reported an increased risk of cemented or cementless femoral fracture (OR, [95% to p with and this should be in Hip Rehabilitation The of rehabilitation has been In their study, et al. compared rehabilitation with a program in patients undergoing THA or The authors found significantly improved scores for (p health-related quality of (p = (p = and (p = at 10 However, the authors on the overall small effect size as well as the of patients who were undergoing THA and patients who were undergoing TKA that analysis As such, further research is required to answer this interesting question. 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