Direct Anterior Approach Total Hip Arthroplasty Using a Morphometrically Optimized Femoral Stem, a Conventional Operating Table, Without Fluoroscopy

A comprehensive analysis on contributing factors for varus or valgus malposition of femoral stems in uncemented total hip arthroplasty via DAA

Background

Varus or valgus malposition of uncemented femoral stems have been described to have detrimental effects for long term implant survival. Various pre- and intra-OP factors have been suggested to be relevant, one of them being the approach to the hip. The aim was to investigate several pre- and intra-OP factors associated with femoral stem malpositioning in a large series of DAA hips.

Methods

A series of 400 consecutive patients (416 hips) who underwent navigated (Brainlab) cementless Total Hip Arthroplasty (THA) in 2022 (Corail or Actis stem DePuy Synthes) via a direct anterior approach (DAA) was analyzed. Preoperative data were collected based on patients' demographics, radiographic information [critical trochanteric angle (CTA), centrum collum diaphyseal (CCD) angle, greater trochanter overhang, femoral neck resection angle, femoral neck resection height and Door classification], and these were correlated with the postoperative stem position. Univariable and multivariable linear regression were carried out to determine significant factors that contribute to varus and valgus stem malalignment.

Results

With the DAA approach, 56.5 % of stems were placed in an optimal neutral position, 38.4 % were in acceptable position of 0.1°-2° varus/valgus and only 5 % had a deviation larger than 2° varus/valgus. The critical trochanteric angle (CTA) was statistically significant in determining varus stem placement whereas centrum collum diaphyseal angle (CCD) was found to affect valgus stem malpositioning. All other factors have shown no relevant effect on stem placement using stepwise regression method.

Conclusion

In DAA, 95 % of stems were found in a varus/valgus position of 2° or less. In pre-operative measurement, only femoral morphology (e.g. CTA & CCD) were found to be relevant, affecting varus/valgus stem malposition. All other tested modifiable and non-modifiable factors had no significant effect. Therefore, pre-OP templating including measurement of CTA and CCD, intra-operative assessment as well as proper operative techniques are paramount to prevent excessive varus/valgus mal-position of femoral stem in DAA.

Impact of intraoperative fluoroscopic beam positioning relative to the hip and pelvis on perceived acetabular component position

Background

Parallax is poorly understood and can mislead surgeons using intraoperative fluoroscopy (IF) to guide cup placement during anterior approach (AA) total hip arthroplasty. The purpose of this study was to examine how changes in fluoroscopic beam positioning in relation to the hip and pelvis affects the projected acetabular image.

Methods

An acetabular component was positioned in an anatomic pelvis model in 45° and 20° of abduction and anteversion, respectively using a computer assisted cup targeting system. Fluoroscopic images were taken at various caudal and cranially directed angles with the fluoroscopic beam centered over the hip then pelvis. In each position, four independent observers measured the abduction and anteversion angles of the projected cup image using the same computer targeting system.

Results

Cup abduction and anteversion measured 43.5° and 19.5° when IF was centered over the hip and 40.5 and 27.5° when centered over the pelvis in the neutral position. Increasing the caudal direction of the beam 20° increased the projected abduction/anteversion angles by approximately 7°/12° and 9°/16° when centered over the hip and pelvis respectively. Increasing the cranial direction of the beam 20° decreased the measured abduction/anteversion angles by roughly 4°/20° and 4°/24° when centered over the hip and pelvis, respectively.

Conclusion

The projected image of the acetabular component can change dramatically depending on fluoroscopic beam position relative to the hip and pelvis. Recognizing the approximate direction and magnitude of change with differing fluoroscopy positions may help surgeons avoid cup malpositioning.

Varus malalignment of short femoral stem not associated with post-hip arthroplasty fracture

INTRODUCTION

Periprosthetic femoral fractures are an increasingly common post-operative complication of total hip arthroplasty (THA). Though varus malalignment is known to increase fracture risk in standard-length femoral stems, varus malalignment is not as well studied in short stems. Therefore, the purpose of this study was to determine if varus malalignment contributes to early periprosthetic fracture risk in a cementless taper-wedged, short femoral stem.

MATERIALS AND METHODS

This retrospective review included 366 consecutive patients (441 THAs) having undergone THA via anterior approach by a single surgeon between July 2014 and December 2016. All patients received the same short, cementless femoral stem. Femoral component angle was measured on 6-week post-THA weight-bearing radiographs, with malalignment defined as a femoral component angle exceeding 0° ± 3°. Periprosthetic femoral fracture and aseptic loosening occurring within 2 years post-THA were recorded.

RESULTS

The final data analysis included 426 hips with a mean follow-up time of 32.9 ± 10.2 months. Varus and neutral alignment occurred in 84 (19.6%) and 342 (79.9%) of stems, respectively. Three (0.7%) periprosthetic femoral fractures occurred within 2 years, all occurring in patients with neutrally aligned femoral stems. One (0.2%) stem failed due to aseptic loosening and was malaligned.

CONCLUSION

Despite nearly 20% of stems placed in varus alignment, three of the four early complications occurred in a neutrally aligned stem. Based on these results, forceful intraoperative realignment of a short femoral stem with good initial fixation may present an unnecessary increased risk of intraoperative fracture.

Component placement accuracy of two digital intraoperative fluoroscopy supplementation systems in direct anterior total hip arthroplasty

INTRODUCTION

Intraoperative fluoroscopy (IF) may increase accuracy of component placement when performing direct anterior approach total hip arthroplasty (THA), however, unguided IF continues to produce inconsistent results. Supplementation of IF, with a digital grid (Grid) system or digital overlay (Overlay), may increase component placement accuracy. The purpose of this study was to compare component placement accuracy following THA when IF was supplemented with the Grid or Overlay technique.

MATERIALS AND METHODS

Acetabular abduction and anteversion, with leg length discrepancy (LLD) and global hip offset (GHO) were retrospectively evaluated for unilateral and bilateral THA patients from 6-week post-operative radiographs. Target component placement were GHO and LLD < 10 mm, abduction 45° ± 10° and anteversion 15° ± 10° for Overlay and 17° ± 10° for Grid. Differences between the Overlay and Grid were determined by univariate analyses.

RESULTS

The Overlay and Grid groups included 178 patients (217 hips) and 262 patients (317 hips), respectively. Target placement with the Overlay and Grid was achieved for GHO in 98.3% and 95.7% of cases (p = 0.108), LLD in 100% and 98.4% of cases (p = 0.121), cup abduction in 98.2% and 97.4% of cases (p = 0.384), and cup anteversion in 97.7% and 71.1% of cases (p < 0.001), respectively. Surgical time was significantly longer in Overlay compared to Grid (Unilateral 77.5 ± 14.1 min and 68.8 ± 12.2; p < 0.001; Bilateral 184.6 ± 27.0 min and 165.5 ± 23.1; p < 0.001, respectively).

CONCLUSION

Although no difference was found between the Grid and the Overlay cohorts for LLD, GHO or abduction angle, the Overlay resulted in greater accuracy for acetabular component anteversion angle, with only a slight decrease in surgical efficiency.

Subsidence of a metaphyseal-anchored press-fit stem after 4-year follow-up: an EBRA-FCA analysis

PURPOSE

Uncemented stem migration analysis by EBRA-FCA (Einzel-Bild-Roentgen Analyse, Femoral Component Analyse) has been seen to be a good predictive indicator for early implant failure. In this study, we investigated the migration behavior of a cementless metaphyseal-anchored press-fit stem after 4-year follow-up.

METHODS

Applying a retrospective study design, we reviewed all consecutive patients who between 2012 and 2017 received a cementless Accolade II press-fit stem at our Department. We reviewed medical histories and performed radiological measurements using EBRA-FCA software. EBRA-FCA measurements and statistical investigations were performed by two independent investigators.

RESULTS

A total of 102 stems in 91 patients (female 60; male 31) fulfilled our inclusion criteria. Mean age at surgery was 66.2 (range 24.3-92.6) years. EBRA migration analysis showed a mean subsidence of 1.4 mm (range 0.0-12.0) at final follow-up. The angle between stem and femur axis was 0.5° (range 0.0°-2.8°) after 48 months. No correlations between gender or Dorr types and subsidence were found (p > 0.05). A body mass index > 30 kg/m² showed a significant increase in stem subsidence within the first 6 (p = 0.0258) and 12 months (p = 0.0466) postoperative.

CONCLUSIONS

Migration pattern of the metaphyseal-anchored stem and a low subsidence rate at final follow-up may predict a good long-term clinical result.

TRIAL REGISTRATION

Number: 20181024-1875.

Outcomes of primary total hip arthroplasty using 3D image-based custom stems in unselected patients: a systematic review

To report clinical and radiographic outcomes of primary THA using three-dimensional (3D) image-based custom stems.

This systematic review was performed according to PRISMA guidelines and registered with PROSPERO (CRD42020216079). A search was conducted using MEDLINE, Embase and Cochrane. Clinical studies were included if they reported clinical or radiographic outcomes of primary THA using 3D image-based custom stems. Studies were excluded if specific to patients with major hip anatomical deformities, or if not written in English.

Fourteen studies were eligible for inclusion (n = 1936 hips). There was considerable heterogeneity in terms of manufacturer, proximal geometry, coating and length of custom stems. Revision rates ranged from 0% to 1% in the short-term, 0% to 20% in the mid-term, and 4% to 10% in the long-term, while complication rates ranged from 3% in the short-term, 0% to 11% in the mid-term and 0% to 4% in the long-term. Post-operative Harris hip scores ranged from 95 to 96 in the short-term, 80 to 99 in the mid-term, and 87 to 94 in the long-term. Radiographic outcomes were reported in eleven studies, although none reported 3D implant sizing or positioning, nor compared planned and postoperative hip architecture.

Primary THA using 3D image-based custom stems in unselected patients provides limited but promising clinical and radiographic outcomes. Despite excellent survival, the evidence available in the literature remains insufficient to recommend their routine use. Future studies should specify proximal geometry, length, fixation, material and coating, as well as management of femoral offset and anteversion. The authors propose a classification system to help distinguish between custom stem designs based primarily on their proximal geometry and length.

Cite this article: EFORT Open Rev 2021;6:1166-1180. DOI: 10.1302/2058-5241.6.210053

Outcomes of simultaneous bilateral total hip arthroplasty for 256 selected patients in a single surgeon's practice

AIMS

Total hip arthroplasty (THA) using the direct anterior approach (DAA) is undertaken with the patient in the supine position, creating an opportunity to replace both hips under one anaesthetic. Few studies have reported simultaneous bilateral DAA-THA. The aim of this study was to characterize a cohort of patients selected for this technique by a single, high-volume arthroplasty surgeon and to investigate their early postoperative clinical outcomes.

METHODS

Using an institutional database, we reviewed 643 patients who underwent bilateral DAA-THA by a single surgeon between 1 January 2010 and 31 December 2018. The demographic characteristics of the 256 patients (39.8%) who underwent simultaneous bilateral DAA-THA were compared with the 387 patients (60.2%) who underwent staged THA during the same period of time. We then reviewed the length of stay, rate of discharge home, 90-day complications, and readmissions for the simultaneous bilateral group.

RESULTS

Patients undergoing simultaneous bilateral DAA-THA had a 3.5% transfusion rate, a 1.8 day mean length of stay, a 98.1% rate of discharge home, and low rates of 90-day infection (0.39%), dislocation (0.39%), periprosthetic fracture (0.77%), venous thromboembolism (0%), haematoma (0.39%), further surgery (0.77%), and readmission (0.77%). These patients were significantly younger (mean 58.2 years vs 62.5 years; p < 0.001), more likely to be male (60.3% vs 46.5%; p < 0.001), and with a trend towards having a lower mean BMI (27.8 kg/m² vs 28.4 kg/m²; p = 0.071) than patients who underwent staged bilateral DAA-THA.

CONCLUSION

Patients selected for simultaneous bilateral DAA-THA in a single surgeon's practice had a 3% rate of postoperative transfusion and a low rate of complications, readmissions, and discharge to a rehabilitation facility. Simultaneous bilateral DAA-THA appears to be a reasonable and safe form of treatment for patients with bilateral symptomatic osteoarthritis of the hip when undertaken by an experienced arthroplasty surgeon with appropriate selection criteria. Cite this article: Bone Joint J 2021;103-B(7 Supple B):116-121.

Direct anterior approach or posterior approach in total hip arthroplasty: A direct comparative study protocol

BACKGROUND

Two familiar surgical methods, posterior approach (PA) and direct anterior approach (DAA), have been extensively utilized in the treatment of total hip arthroplasty (THA) with similar long-term rates of success. The sufficient sample size and a good clinical trial are urgently needed. Considering the above factors, we implemented a retrospective research to compare the prognosis of patients with primary THA receiving the techniques of PA or DAA.

METHODS

This is an observational retrospective research that prospectively collected information via several surgeons at a center utilizing the 2 above treatment methods for unilateral primary total hip arthroplasty. A review of primary THA performed with DAA or PA between February 2017 and February 2019 was conducted in our hospital. The inclusion criteria contained the degenerative changes in end-stage of hip owing to the rheumatoid arthritis, inflammatory arthritis, and osteoarthritis, as well as the Crowe I and II dysplasia that did not require the enhancement. The primary endpoint was the Harris hip score. The measures of secondary outcome contained the operation time, length of incision, hospital stay, the complications after operation, as well as patient satisfaction. The Statistical Package for Social Sciences version 20.0 was utilizing for the statistical analysis (IBM Corporation, Armonk, NY).

RESULTS

We assumed that the 2 treatment methods possess similar results.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry6008).

Patients With Modular-Neck Total Hip Arthroplasty: A Brief Five-Year Follow-Up Study

BACKGROUND

We have previously reported the early clinical results of a modular-neck stem identifying an early 2-year revision rate of 13% due to neck-stem corrosion. This report updates our findings to a midterm mean follow-up of 5 years.

METHODS

This is a consecutive retrospective review of 186 modular-neck hips in 175 patients with a mean follow-up period was 60.1 ± 22.9 months (range 24-100). We reviewed clinical findings, routine radiographs, detailed imaging (metal artifact reduction software-magnetic resonance imaging, ultrasound), and serum ion levels of cobalt and chromium. We performed a survival analysis with the endpoint defined as revision total hip arthroplasty due to neck-stem corrosion.

RESULTS

We revised 41 hips (22.0%) for neck-stem corrosion. Clinical symptoms (groin pain ± local swelling) were consistently present in those that came for revision. Mean serum cobalt ion levels increased as time passed in all patients. Detailed image findings showed that larger fluid collections and local soft tissue masses were seen predominately in symptomatic patients. However, 14% of patients who underwent revision did not have positive magnetic resonance imaging or ultrasound findings. The survival rate was 87% (95% confidence interval 81-92) at 3 years postoperatively and 72% (95% confidence interval 64-80) at 7 years postoperatively.

CONCLUSION

The revision rate for this modular-neck stem due to neck-stem corrosion at mid-term follow-up almost doubled in comparison to previous short-term results. It seems reasonable to consider clinical follow-up alone as symptoms, rather than blood testing for ion levels, seem to be the defining characteristic of failure.

Predictors of Perioperative Vancouver B Periprosthetic Femoral Fractures Associated With the Direct Anterior Approach to Total Hip Arthroplasty

BACKGROUND

There is an association between intraoperative and postoperative femoral fractures and the direct anterior approach (DAA) to total hip arthroplasty (THA). The purpose of our study is to identify risk factors for Vancouver B fractures and to establish a predictable timeline for when these occur.

METHODS

We retrospectively identified patients with Vancouver B periprosthetic femoral fractures (n = 49) after 11,509 elective primary cementless THA procedures through the DAA between 2012 and 2018 at a single institution. Fracture patients were matched to nonfracture patients (n = 267) by date of surgery and surgeon. Clinical and radiographic factors were collected for multivariable analysis to identify predictors of fracture.

RESULTS

Periprosthetic Vancouver B femoral fracture incidence was 0.4%. 48 (98%) fractures were postoperative. Fractures occurred at an average of 44 days after surgery (range: 1 to 653 days) with >85% of fractures occurring in the first 6 weeks postoperatively. Significant variables predictive of fracture included >3 degrees valgus and >5 degrees varus coronal stem malalignment, Dorr B and C femoral geometry, lower canal flare index (2.75 vs 3.20), advanced age, increased comorbidities, greater stem canal fill, and right-sided procedures.

CONCLUSION

Despite an overall low rate of Vancouver B perioperative periprosthetic femoral fractures, it is a devastating complication that typically presents within the first 6 weeks after DAA THA surgery. The risk is increased in patients with unfavorable proximal femoral geometry, coronal stem malalignment, advanced age, increased comorbidities, and right-sided procedures.

Are physical therapy pain levels affected by surgical approach in total hip arthroplasty? A randomized controlled trial

The main objective of this study was to evaluate the difference in pain levels during postoperative physical therapy pathways in patients who underwent a cement less total hip replacement either through a muscle sparing direct anterior approach (DAA), or the classic trans-gluteal lateral approach (LA). One hundred and twelve (112) patients were randomized into two equal groups. Baseline values of myoglobin levels were acquired prior to surgery and repeated at 6 hours postoperatively as a biomarker for muscle damage. Pain levels during the first passive and consecutive 3 active physical therapy sessions were noted using a visual analogue-numeric scale (VAS). Pain levels were also acquired at 6 weeks, 3 months, 6 months and 1 year, following a 20-meter (65.6 feet) walking test. Postoperative myoglobin (ng/mL) levels were significantly higher (p< 0.05) in the LA group (335.05±83.54) then the DAA group (237.71±57.54). Pain levels were significantly lower (p<0.001) in the DAA group for both passive (2.5±1.45 vs. 4.28±2.19) and active physical therapy sessions and there was a positive correlation between postoperative myoglobin levels and pain levels until 6 postoperative weeks. There was no significant difference in demographics between the two groups except for gender distribution. The direct anterior approach’s main advantage of being a minimally invasive muscle sparing technique is showing a better rehabilitation experience with lower pain levels during passive and active physical therapy when compared to the classic trans-gluteal lateral approach.