Small femoral offset is a risk factor for lateral femoral cutaneous nerve injury during total hip arthroplasty using a direct anterior approach

Meralgia Paresthetica-An Approach Specific Neurological Complication in Patients Undergoing DAA Total Hip Replacement: Anatomical and Clinical Considerations

Introduction: Mini-invasive surgical (MIS) approaches to total hip replacement (THR) are becoming more popular and increasingly adapted into practice. THR via the direct anterior approach (MIS DAA) has become a rather controversial topic in hip arthroplasty literature in the last decades. Our retrospective observational study focuses on the prevalence of one approach-specific complication-lateral femoral cutaneous nerve (LFCN) iatrogenic lesion-and tries to clarify the possible pathogenesis of this injury. Methods: This is a retrospective single-cohort observational single-center and single-surgeon study. Our patient records were searched for the period from 2015 to 2017-after a safe period of time after the learning curve for MIS DAA. All intra- and post-operative lesions of the LFCN were recorded. Lesion of the LFCN was confirmed by a neurological examination. Minimum patient follow-up was 2 years. Results: This study involved 417 patients undergoing single-side THR via MIS DAA. Patients were examined on follow-up visits at 6 weeks, 6 months, 1 year, and 2 years after surgery. There were 17 cases of LCFN injury at the 6 weeks early follow-up visit (4.1%). All cases of clinically presenting LFCN injury resolved at the 2-year follow-up ad integrum. Discussion: Possible explanations of such neurological complications are direct iatrogenic injury, vigorous traction, hyperextension, or extreme external rotation of the operated limb. Use of a traction table or concomitant spinal pathology and deformity also play a role. Prevention involves stepwise adaptation of the approach during the learning curve period by attending cadaver lab courses, rational use of traction and hyperextension, and careful surgical technique in the superficial and deep fascial layers. Dynamometers could be used to visualise the limits of manipulation of the operated limb. Conclusions: Neurological complications are not as rare but questionably significant in patients undergoing THR via the DAA. Incidental finding of LFCN injury has no effect on the functional outcome of the artificial joint. It can lead to lower subjective satisfaction of patients with the operation, which can be avoided with careful education and management of expectations of the patients.

Comparing the Anterior-Based Muscle-Sparing Approach with the Direct Anterior Approach in Hip Arthroplasty: A Systematic Review and Pairwise Meta-Analysis

Background and Objectives: The anterior-based muscle-sparing (ABMS) approach, which utilizes the interval between the tensor fasciae latae posteriorly, offers several advantages, such as the reduced risk of nerve injury and the freedom to choose various implants. Herein, we aimed to compare the outcome of ABMS to the direct anterior (DA) approach using pairwise meta-analysis techniques. Materials and Methods: A systematic search of the MEDLINE (PUBMED), Embase, and Cochrane Library databases was performed for studies published up to 7 June 2023, which compared the ABMS approach with the DA approach for hip arthroplasty. We compared (1) perioperative outcomes (operation time, visual analog scale (VAS) score, total opioid consumption, length of hospital stay (LOS), and the number of patients discharged to their homes); (2) postoperative complications (neuropraxia/nerve injury, dislocation, surgical site infection, intraoperative fracture, and reoperation rate); and (3) implant position (cup inclination, cup anteversion, and stem alignment). Results: Ten studies were eligible for meta-analysis, including 1737 patients who underwent hip arthroplasty with the ABMS approach and 1979 with the DA approach. The pooled analysis showed no differences in all outcome variables, including perioperative outcomes, postoperative complications, and the implant position between the two surgical approaches. Conclusions: In current meta-analysis, the ABMS approach demonstrated comparable results to the conventional DA approach in terms of both clinical and radiologic outcomes as well as postoperative complications. Furthermore, the ABMS approach has the advantage of a broader indication and fewer limitations in terms of the surgical position compared to the DA approach. Therefore, the ABMS approach can be even more beneficial as an option within MSA, surpassing the utility of the DA approach.

Recent advances in the direct anterior approach to total hip arthroplasty: a surgeon's perspective

INTRODUCTION

The direct anterior approach (DAA) has its origins in the first and oldest approach for hip replacement in the literature, but at the same time it would not be fanciful to suggest its increasing popularity as the latest approach for hip replacement procedures, especially among younger surgeons. However, in a geographical context, the DAA is not considered the major approach in most countries. Moreover, the term DAA encompasses numerous variations in terms of technique.

AREAS COVERED

In this narrative review, we describe our recent experience of advances in the DAA in terms of improved techniques and devices, along with some of its disadvantages. Also, we express our perspective on its future application.

EXPERT OPINIONS

The DAA is established as one of exemplary approaches to THA. The use of fluoroscopy, the traction table, and appropriate soft tissue management has become essential in the DAA for a safe and trouble-free procedure with adequate patient comfort. With the combination of recent technologies such as robotics, three-dimensional preoperative planning, and artificial intelligence (AI)-based surgeon assist systems, we can look forward to the DAA being performed more efficiently in the future.

Nerve Injuries Following Total Hip Arthroplasty: The Influence of Surgical Approach

Nerve injuries following total hip arthroplasty are rare but devastating complications. The most important modifiable risk factor remains the choice of hip approach and surgical technique applied. The risk of nerve injuries is related to technical complexity of the procedure and anatomic variability of the nerves. Surgeons should remain cognizant of inherent risk factors, variations in the course and branching patterns of different nerves, and technical considerations of the surgical approach to mitigate risks. This article reviews the literature on postsurgical nerve injuries following total hip arthroplasty and characterizes the influence of surgical approach on the risk of this complication.

Conversion of a Fused or Ankylosed Hip to Total Hip Arthroplasty: Is the Direct Anterior Approach in the Lateral Decubitus Position an Ideal Solution?

Background

Total hip arthroplasty (THA) using the direct anterior approach (DAA) is becoming increasingly popular due to its potential benefits over the posterolateral approach (PLA). However, few studies have compared the efficacies of these two surgical approaches in hip fusion treatment. This study compared early clinical direct anterior and posterolateral THA outcomes in hip fusion treatment.

Methods

Here, 127 hips (65 DAA, 62 PLA) were retrospectively evaluated. Early postoperative functional outcomes of DAA and PLA groups were assessed using Harris score and Oxford Hip Score (OHS) and standard anteroposterior hip radiographs. Surgical characteristics, perioperative results, and complications within 6 months postoperatively were recorded.

Results

Though baseline values were similar, Harris and OHS scores were better in the DAA group than in the PLA group at 1 and 3 months postoperatively. The average cup anteversion angle was significantly greater in the DAA group than in the PLA group (12.7° vs. 11.1°). More hips undergoing DAA were successfully orientated in both inclination and anteversion angles (46 vs. 32). Early postoperative hip function predictors were preoperative fused hip position, surgical approach, and range of motion. DAA was associated with reduced postoperative blood loss and shorter hospital stays. Furthermore, 14 vs. 8 complications occurred in the DAA vs. PLA group. Lateral femoral cutaneous nerve injuries were observed in eight hips (12.3%) of the DAA group.

Conclusion

For fused or ankylosed hips, THA using DAA in the lateral decubitus position may result in excellent prosthesis positioning and faster postoperative recovery throughout early follow-up vs. PLA.

Direct anterior approach for total hip arthroplasty with patients in the lateral decubitus versus supine positions: A prospective, double-blinded, randomized clinical trial

PURPOSE

The direct anterior approach (DAA) for total hip arthroplasty (THA) can be performed with patients in either in the lateral decubitus or supine position. Prompted by the lack of studies addressing differences between the two positions, this investigation aimed to examine clinical and radiographic outcomes and compare the lateral decubitus versus the supine position for THA using the DAA.

METHODS

Between January 1 and October 1, 2020, 90 patients who underwent primary unilateral THA using the DAA were recruited, with 54 (60%) undergoing THA in the supine position (SP group) and 36 (40%) in the lateral decubitus position (LP group). Technical information, clinical and radiographic outcomes, and patient-reported outcomes, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short-Form-12 (SF-12) were evaluated. All data were subjected to several statistical tests.

RESULTS

There were no preoperative differences in baseline characteristics between the LP and SP groups, which were also similar in terms of operative duration, length of hospital stay, and blood loss. Radiographic assessment confirmed satisfactory positioning of the prosthesis in both groups. There were no significant differences in terms of CK-MB and hemoglobin levels, Harris Hip Score, WOMAC, UCLA, visual analog scale score, and SF-12. The incidence of complications in the LP group was lower than in the SP group.

CONCLUSION

Total hip arthroplasty performed via DAA in the LP and SP groups yielded excellent clinical outcomes, although the incidence of complications in the former was lower than in the latter.

Incidence of lateral femoral cutaneous nerve lesions after direct anterior approach primary total hip arthroplasty - a literature review

INTRODUCTION

Lesions of the lateral cutaneous femoral nerve are a reported complication of the direct anterior approach (DAA) for total hip arthroplasty (THA). Little is known about the incidence rates of this lesion. The goal of this study was to answer the following questions: (1) Is the true incidence rate of LFCN lesions after DAA THA known? (2) What are the reasons for the wide range of reported incidence rates in the literature? (3) Are surgeons increasingly aware of the significance of LFCN lesions?

METHODS

A US Medical Library of Medicine database search was performed for DAA THA. In total, 1261 search results were screened for reported LFCN lesions.

RESULTS

Forty-five studies were included reporting LFCN lesions rates of 0-83%. Subgroup analysis for studies with (group A, 6 studies, n=1113 cases) and without (group B, 39 studies n=16,741) primary focus on the LFCN lesions was performed. Incidence in group A ranged from 14.8-81% (mean 31%) and 0-83% (mean 3.8%) in group B. The difference between the groups was significant (p=0.005). No uniform and time sensitive definition of postoperative LFCN lesions was found in the literature. An analysis of the publication year and the discovered incidence rate showed an increase of incidence rates [rs=0.521 (p<0.001, two-tailed)] over time.

CONCLUSION

Despite the absence of a uniform definition: LFCN lesions after DAA THA are a frequent and, in the past, often underestimated complication.

LEVEL OF EVIDENCE

IV; systematic review of level II to level IV studies.

Does surgical body position influence the risk for neurovascular injury in total hip arthroplasty? A magnetic resonance imaging study

BACKGROUND

Neurovascular injury is a critical complication in total hip arthroplasty (THA). However, neurovascular geographic variations around the hip joint in different body positions have not been examined. This study investigated the differences in hip neurovascular geography in the supine and lateral positions using magnetic resonance imaging (MRI).

HYPOTHESIS

The neurovascular geography of the hip is influenced by differences in surgical body position.

PATIENTS AND METHODS

This was a single-center prospective study of 15 healthy volunteers enrolled between January 2018 and March 2019. Each subject's bilateral hips were scanned with a 3-T MRI scanner in both the supine and lateral positions. In T1-weighted axial images at the level of the hip center, the anterior and posterior acetabular edges were defined as reference points at which retractors are commonly placed during surgery. We measured the distance between the anterior acetabular edge and the femoral nerve (dFN), femoral artery (dFA), and femoral vein (dFV), as well as that between the posterior acetabular edge and the sciatic nerve (dSN). The primary outcome measures were the distances in both the supine and lateral positions.

RESULTS

dFN, dFA, and dFV in the supine and lateral positions (mm, mean±standard deviation) were 25.8±5.6 and 32.4±6.4 (p<0.0001), 25.7±4.5 and 32.2±5.0 (p<0.0001), and 26.5±4.8 and 32.3±5.1 (p<0.0001), respectively. Most of these elements moved anteromedially in the lateral position compared to the supine position. There was no significant difference in dSN between the supine and lateral positions (23.7±4.9 and 24.5±6.5 (p=0.46).

DISCUSSION

THA in the supine position may be accompanied by a higher risk of femoral neurovascular injury than that in the lateral position. The application of our findings could reduce the risk of femoral neurovascular injury during THA.

LEVEL OF EVIDENCE

III; prospective diagnostic case control study.

Preoperative ultrasound to map the three-dimensional anatomical distribution of the lateral femoral cutaneous nerve in direct anterior approach for total hip arthroplasty

Background

The postoperative complaints of hypoesthesia or a burning sensation due to lateral femoral cutaneous nerve (LFCN) injury in patients are not yet solved. The present study aimed to identify the three-dimensional (3D) distribution of LFCN using preoperative ultrasound and evaluate the rate of injury in direct anterior approach for total hip arthroplasty.

Methods

A total of 59 patients (28 males and 31 females, age 69.0 ± 4.6 years, BMI 24.7 ± 3.0 kg/m²) were randomly allocated to the ultrasound group and 58 patients (28 males and 30 females, age 68.5 ± 4.5 years, BMI 24.8 ± 2.8 kg/m²) were in the control group. Surgeons received the data of 3D distribution of LFCN only in the ultrasound group before surgery with respect to the direction, the depth on the skin, and the length to tensor fasciae latae (TFL). The anatomical characteristics of LFCN in the surgical region were summarized. At 1 and 3 months of post surgery, the rate of LFCN injury and abnormal sensitive area was evaluated in both groups.

Results

There was a significant consistency in gender, age and BMI of these two groups (P > 0.05). Based on the data from the ultrasound group, over 90% of patients had one or two branches of LFCN. LFCN always courses in the fascia layer, the depth ranged from 6.8 ± 2.6 (3.0–12.0) mm to 11.1 ± 3.4 (4.0–17.0) mm and depended on the thickness of the subcutaneous fat, and length was 3.3 ± 4.6 (− 5.0–10.0) mm at proximal part and − 2.7 ± 4.7 (− 10.0–8.0) at distal end to the medial edge of TFL. Both the rate of LFCN injury and abnormal sensory area in the ultrasound group was significantly lower than those in the control group (3.4% vs. 25.9%, P = 0.001, at 1 month; 3.4% vs. 22.4%, P = 0.005, at 3 months).

Conclusions

LFCN mostly courses along the medial border of TFL in the fascia layer. The 3D distribution of LFCN using preoperative ultrasound mapping could help the surgeons to evaluate the risk of injury preoperatively and decrease the rate of injury during the operation. However, some branch injuries, especially for the fan type LFCN, could not be avoided.

Bikini Incision Increases the Incidence of Lateral Femoral Cutaneous Nerve Injury in Direct Anterior Approach Hip Arthroplasty: A Prospective Ultrasonic, Electrophysiological, and Clinical Study

BACKGROUND

Lateral femoral cutaneous nerve (LFCN) injury has been widely reported as one of the most common complications of direct anterior approach (DAA) hip arthroplasty. Bikini incision is considered to increase the incidence of this complication.

METHODS

A prospective randomized study was conducted after including ninety-nine bikini and ninety-six longitudinal incision DAA cases from May to November 2020. The occurrence of LFCN was examined using ultrasound before and after surgery. The recovery of injury symptoms was evaluated by continuous clinical follow-up until six months, and the patients were treated with mecobalamin and/or celecoxib. Sensory conduction velocity and sensory action potential amplitude of the LFCN were measured after surgery in symptomatic patients.

RESULTS

Eighty five (43.6%), sixty seven (34.4%), and forty three (22.0%) cases of LFCN were of the anterior trunk, posterior trunk, and fan types, respectively, before surgery. All one hundred ninety five patients completed the follow-up period. Fifty-seven patients had symptoms of LFCN injury, including thirty six and twenty one patients in the bikini group and longitudinal group, respectively, with significantly different incidence rates (36.4% and 21.9%, respectively; P < .05). Of these, thirty two (56.1%), thirteen (22.8%), and twelve (21.1%) cases were of the anterior trunk, posterior trunk, and fan types, respectively. Sensory conduction velocity and sensory action potential amplitude significantly decreased after surgery in both groups (P < .05). Seventeen cases showed reduction of symptoms within three months. Forty six cases showed self-recovery within six months and eleven cases showed persistent symptoms at the final follow-up.

CONCLUSION

Bikini incision DAA hip arthroplasty may increase the incidence of LFCN injury, and the anterior trunk distribution type is most likely to be affected. (Clinical Trial Registration Number: CHICTR2000035107).

Fatty muscle infiltration of the hip lateral rotator muscles following direct anterior minimally invasive total hip arthroplasty

INTRODUCTION

There is no consensus as to the best surgical approach to use when doing total hip arthroplasty (THA). There has been renewed interest in recent years in so-called anatomic minimally invasive direct anterior approaches (DAA). However, their reduced impact has not been confirmed with imaging data. This led us to carry out a prospective study to 1) evaluate fatty infiltration (FI) of muscles around the hip joint and 2) analyze how this FI changes over time.

HYPOTHESIS

THA done by the DAA induces FI of the anterolateral muscles around the hip adjacent to the approach.

MATERIAL AND METHODS

A continuous case series of THA by DAA using a traction table was done by a single experienced surgeon. MRI images (GE Optima* MR360 1.5T) were taken preoperatively, then at 3 months and 1 year after the THA surgery. Muscle FI was classified as described by Goutallier by an independent radiologist on all the muscles around the hip joint. A Wilcoxon test was used to compare the preoperative MRI data to the data at 3 months and 1 year postoperative.

RESULTS

Sixty-nine MRI examinations were done in 23 patients. Two were not interpretable because the patient moved during the preoperative acquisition. No intraoperative or postoperative complications were reported. None of the patients had hip pain or limped at 1 year postoperative. The FI was significantly worse from the preoperative MRI to the 3-month postoperative MRI (p=0.02) and 1-year MRI (p=0.0007) in the internal obturator muscle and at 1 year in the piriformis muscle (p=0.04). There was no significant difference for the other muscles. The rectus femoris, superior and inferior gemellus muscles and the quadratus femoris could not be analyzed.

DISCUSSION

Our hypothesis was not confirmed, although we had a paradoxical finding of muscle FI in the posterior lateral rotator muscles not the anterolateral muscles after THA by DAA. These lesions may be secondary to detachment or denervation of these muscles when elevating the femur to prepare the femoral canal or insert the stem.

LEVEL OF EVIDENCE

IV; Prospective case series.

The direct anterior approach for simultaneous bilateral total hip arthroplasty: a short-term efficacy analysis

Purpose

Compared to the posterior approach (PA), the direct anterior approach (DAA) can achieve better clinical outcomes for total hip arthroplasty (THA). The purpose of this study was to investigate whether the same advantages associated with the DAA could be attained in patients undergoing simultaneous bilateral THA.

Method

We retrospectively reviewed 89 patients who underwent one-stage bilateral THA through the DAA (group A, n = 46) and through the PA (group B, n = 43) between June 2015 and November 2017 at our institution. The patients were followed up for a minimum of 1 year. There were no significant differences in gender, age, body mass index (BMI), preoperative hemoglobin level, preoperative Harris hip score (HHS), and preoperative visual analogue scale (VAS) score between the two groups (P > 0.05 for all).

Results

The incision length, operation time, intraoperative blood loss, blood transfusion volume, and the length of stay (LOS) were significantly less in group A than in group B (p < 0.05). The surgery-related complications were not significantly lower in group A (5.43%) than in group B (10.47%) (χ² = 2.209, p = 0.112). In 46 cases in group A, one hip had an acetabular anteversion higher than normal value. In both groups, one hip developed aseptic loosening. The HHS was significantly higher in group A than in group B 1, 3, 12 month(s) after operation (p < 0.05). The VAS was significantly lower in group A than in group B 1, 3, 12 month(s) after operation. Against the simple Likert scale, comprehensive satisfaction was significantly higher in group A (97.8%, 45/46) than in group B (76.7%, 33/43) (χ² = 9.119, p = 0.003).

Conclusion

In patients who underwent simultaneous bilateral THA, DAA could significantly relieve pain, accelerate the functional recovery of hip joint and improve the satisfaction more than PA. In clinical practice, however, more attention should be paid to strict compliance to operative indications and the prevention of early complications. The long-term effectiveness warrants further observation.

ALDI (Anterior Lateral Decubitus Intermuscular) approach to the hip: Comprehensive description of the surgical technique with operative video

The direct anterior approach to the hip is judged to be difficult and even after many solutions, such as special operating tables, have been proposed to perform it, in some reports the complication rate remains high. The complications reported are nerve lesions, dislocation, muscles damages, intraoperative fractures. We describe a modification of the anterior approach, undertaken keeping the patient in lateral decubitus, in order to gain a better range of leg movement and a significant reduction of the force applied to the retractors, the technique was named ALDI (anterior lateral decubitus intermuscular) approach. The surgeon starts behind the patient as in all the other traditional approaches, to maintain unchanged the acetabular view and the dexterity in cup implantation. For the femoral preparation, he moves in front of the patient to have a better visualization. In a series of 150 patients, with a mean operative time of 51.38minutes (range, 40-112), we had no intraoperative fractures, one (0.6%) lateral femoral cutaneous nerve temporary neurapraxia, one (0.8%) posttraumatic dislocation four years after the operation and, no revisions for aseptic loosening or infection. At the 5 years follow-up, the mean Oxford Hip score was 45.2 (range, 38-48; SD 2.6), the mean Harris Hip Score was 96,7 (range, 76-100; SD 2.8), and the mean UCLA score was 7 (range, 5-10; SD 1.4). The possibility to always obtain the optimal position of the surgical window with reduced tension on the muscles, and the unchanged initial surgeon position, could make the ALDI approach the ideal technique for the surgeons that decide to perform an anterior approach.

Laparoscopic-Assisted Intra-Abdominal Section of the Lateral Femoral Cutaneous Nerve for Meralgia Paresthetica Following Anterior Hip Arthroplasty

BACKGROUND

Meralgia paresthetica, a pain syndrome that is caused by injury to the lateral femoral cutaneous nerve, is a well-documented complication after anterior hip arthroplasty (THA). Traditional treatment of this peripheral nerve entrapment syndrome can be complicated in patients who have had THA via an anterior approach owing to the presence of scar in the postoperative bed.

CASE DESCRIPTION

In a 70-year-old man, we performed a novel laparoscopic-assisted intra-abdominal approach to treat meralgia paresthetica in the setting of previous anterior THA.

CONCLUSIONS

Minimally invasive intra-abdominal treatment of meralgia paresthetica following anterior THA results in durable pain relief. This approach is a helpful alternative to traditional techniques of decompression or section of the lateral femoral cutaneous nerve below the inguinal ligament.

Leg length discrepancy after total hip arthroplasty: Can leg length be satisfactorily controlled via anterior approach without a traction table? Evaluation in 56 patients with EOS 3D

BACKGROUND

Leg length discrepancy (LLD) occurs in about 25% of cases after total hip arthroplasty (THA) and adversely affects function if greater than 10mm. When using the direct anterior approach (DAA), limb length control is considered easier with a standard operating table than with a traction table. However, this assumption has not been confirmed. More specifically, no studies have used EOS imaging, which is currently the reference for assessing limb length. The objectives of this retrospective study were: (1) to use EOS imaging to determine whether THA via the DAA on a standard table allowed satisfactory limb length control; (2) whether LLD was associated with other parameters such as age, gender, body mass index (BMI), or side; and (3) to compare clinical score values between patients with and without LLD.

HYPOTHESIS

The DAA without a traction table allows satisfactory limb length control as assessed using 3D EOS imaging.

MATERIAL AND METHODS

This retrospective descriptive study included 56 patients who underwent primary THA via the DAA between March 2013 and June 2014. LLD was measured on pre- and post-operative EOS images, using sterEOS™ 3D software. Age, gender, BMI, and side of THA were collected. The 12-item Short Form score, Harris Hip Score, and Postel-Merle d'Aubigné score were determined to look for radio-clinical correlations.

RESULTS

Of the 56 patients, 15 (26.8%) had an LLD >10mm before THA and 12 (21.4%) after THA. Limb length equality was restored in 7 patients with 1 with a shorter and 1 with a longer limb before THA. In 5 patients with equal limb length before THA, the operated limb was lengthened after THA, by a mean of 8.92mm (range, 5.8-10.8mm). Thus, in all, 5/56 (8.9%) patients experienced a detrimental change in limb length due to the surgery. No statistically significant differences were found between patients with and without LLD regarding age, gender, BMI, side, or clinical scores.

DISCUSSION

Although the frequency of LLD after THA in our study was consistent with earlier reports, our results show that good limb length control can be obtained via the DAA with a standard operating table. Thus, 7 of the 11 patients with a shorter limb and 1 of 4 with a longer limb before THA had equal limb lengths after THA, and only 8.9% of patients experienced a detrimental increase in limb length after THA. The DAA without a traction table allows satisfactory intra-operative limb length control based on visualisation of anatomical landmarks (antero-superior iliac spines and medial malleoli). This technique is therefore valuable for limiting the risk of LLD. When combined with 3D EOS planning, it may increase the accuracy of limb length adjustment.

LEVEL OF EVIDENCE

IV, retrospective study with no control group.

Preoperative ultrasound to identify distribution of the lateral femoral cutaneous nerve in total hip arthroplasty using the direct anterior approach

Introduction: Recently, the branching pattern of the lateral femoral cutaneous nerve (LFCN) named Fan type has been reported that LFCN injury cannot be avoided in surgical dissections that use the direct anterior approach to the hip joint in the cadaveric study. We hypothesized that the Fan type can be identified by ultrasound The aim of this study was to investigate whether LFCN injury occurs in DAA-THA in cases identified as the Fan type based on preoperative ultrasound of the proximal femur.

Methods: Ultrasonography of the proximal femur on the surgical side was performed before surgery and the LFCN distribution was judged as the Fan type or Non-Fan type. A self-reported questionnaire was sent to the patients at two months after surgery, and the presence or absence of LFCN injury was prospectively surveyed.

Results: After application of exclusion criteria, 45 hips were included. LFCN injury was observed after surgery in 9 of the 10 patients judged as the Fan type based on the ultrasound of the proximal femur (positive predictive value: 90%), and no LFCN disorder was actually observed in 25 of the 26 patients judged as Non-Fan type (specificity: 96.2%).

Conclusions: To prevent injury of the LFCN in patients judged as the Fan type on the ultrasound test before surgery, the risk of direct injury of the LFCN may be reduced through the approach in which an incision is made in the fascia which is opposite to the radial spreading, i.e., between the sartorius and tensor fasciae latae muscles or slightly medial from it.

[Short-term effectiveness analysis of one-stage bilateral total hip arthroplasty by direct anterior approach]

Objective

To compare the effectiveness of one-stage bilateral total hip arthroplasty by direct anterior approach (DAA) and by posterolateral approach, and to investigate the application value of DAA in one-stage bilateral total hip arthroplasty.

Methods

The clinical data of 65 patients who underwent one-stage bilateral total hip arthroplasty by DAA or posterolateral approach between June 2010 and November 2015 were analyzed retrospectively. DAA was used in 34 cases (group A) and posterolateral approach was used in 31 cases (group B). There was no significant difference in the gender, age, body mass index, preoperative hemoglobin level, etiology, disease duration, preoperative Harris score, and preoperative visual analogue scale (VAS) score between 2 groups ( P>0.05) with comparability. The incision length, operation time, intraoperative blood loss, total blood transfusion volume, hospitalization time, early postoperative complications, Harris score, and VAS score were recorded and compared between 2 groups. The simple Likert scale method was applied to evaluate the patient satisfaction, and the imaging evaluation was used.

Results

The incision length, operation time, intraoperative blood loss, total blood transfusion volume, and hospitalization time of group A were significantly less than those of group B ( P<0.05). The patients were followed up 15-48 months (mean, 25.3 months) in group A and 12-51 months (mean, 27.6 months) in group B. The overall incidence of complications related to surgery in group A (10.29%) was significantly lower than that of group B (19.35%) ( χ²=8.769, P=0.023). The acetabular anteversion and abduction angle were in the normal range of 2 groups except 1 hip (1.47%) of group A had a higher acetabular anteversion than normal value. Unstable fixed prosthesis happened in 1 hip of groups A and B respectively, and the remaining femoral calcar had no obvious bone resorption and fixed stably. The Harris score and VAS score at each time point after operation of 2 groups were significantly improved when compared with preoperative scores ( P<0.05), and the differences between the time points after operation were also significant ( P<0.05). The Harris score at 1 and 3 months after operation and the VAS score at 3 days after operation of group A were significantly better than those of group B ( P<0.05), but no significant difference was found at last follow-up between 2 groups ( P>0.05). According to the simple Likert scale method to analyze patient satisfaction, comprehensive satisfaction of group A (97.1%, 33/34) was significantly higher than that of group B (67.7%, 21/31) ( χ²=10.343, P=0.001).

Conclusion

The application of DAA in one-stage bilateral total hip arthroplasty can significantly relieve the pain, accelerate the recovery of hip joint function, and improve the patient satisfaction. But in clinical application, more attentions should be paid to strictly grasp the indications and prevent the early complications. The long-term effectiveness needs to be further observed.

[Effect of Jumbo cups for total hip arthroplasty revision on femoral offset and hip center of rotation]

Objective

To investigate the change of the femoral offset and hip center of rotation (COR) after using Jumbo cups in total hip arthroplasty (THA) revision.

Methods

The clinical data of 23 patients who underwent THA revision using Jumbo cups between January 2010 and May 2015 were retrospectively analyzed. Morselized bone graft was performed on 8 cases, morselized bone graft combined with structural bone graft on 10 cases. There were 10 males and 13 females, aged 65.4 years on average (range, 51-77 years). The disease duration was 1-24 years (mean, 8.57 years). The reasons for revision included aseptic loosening in 21 cases and periprosthetic infection in 2 cases. The Harris hip score and visual analogue scale (VAS) were 43.04±5.05 and 5.70±0.97 before operation respectively. According to the Paprosky acetabular defect classification, there were 5 cases of type I, 5 cases of type II A, 3 cases of type II B, 6 cases of type II C, and 4 cases of type III A. The X-ray films showed that the femoral offset was (40.65±4.09) mm for normal side and was (44.04±5.08) mm for affected side at preoperation, showing significant difference ( t=4.098, P=0.000). Ten patients underwent femoral offset reconstruction (43.48%) but 13 patients did not (56.52%) before operation. The COR was reconstructed in 10 cases (43.48%); COR elevation was observed in 11 cases (47.83%), and COR decline in 2 cases (8.69%) before operation.

Results

Primary healing of incision was obtained in all patients, with no complication of infection, vascular injury, deep vein thrombosis, dislocation of the joint, or fracture around prosthesis. All the patients were followed up 12-76 months (mean, 22.48 months). The Harris hip score and VAS were 82.09±4.53 and 0.74±0.62 at 1 year after operation respectively, showing significant differences when compared with preoperative scores ( t=37.831, P=0.000; t=22.318, P=0.000). The X-ray films showed that the femoral offset was (43.87±3.57) mm for affected side at 1 year after operation, showing no significant difference when compared with preoperative one ( t=0.250, P=0.805), but significant difference was found between affected side and normal side ( t=5.591, P=0.000). The femoral offset was restored in 16 patients (69.57%) and was not restored in 7 patients (30.43%) after operation. The COR was restored in 15 patients (65.22%) and was not restored in 8 patients (34.78%).

Conclusion

Using Jumbo cups or combined with morselized or structural bone graft is effective in restoring hip COR and femoral offset at the maximum limit in THA revision, with good short-term outcome and improved stability of acetabular prosthesis.