Early Failure of Primary Total Hip Arthroplasty: Is Surgical Approach a Risk Factor?

A new approach to identify wear regions on bearing surfaces of retrieved endoprostheses

Although total hip replacements (THR) can be considered one of the most successful implantable medical devices in history, wear remains the ultimate challenge in order to further increase clinical success. Wear assessment on retrieved implants is the most reliable way to perform research into failure mechanisms. Therefor the bearing surface of the explant is measured geometrically by coordinate measuring machine (CMM). Wear determination in geometrical data is carried out in 3 steps: (1) identifying the worn area, (2) reconstructing the pre-wear geometry and (3) quantify wear as the difference between worn area and pre-wear geometry. In previous studies, assumptions to pre-wear geometry had been made for wear determination (step 2) and the worn area was identified by deviations between measured data and assumed form. Thus, the original form of the retrieved endoprostheses, including form deviations due to the manufacturing process and implantation, was not considered which leads to uncertainties in the wear computed. This work introduces a method which allows to identify the wear area without making assumptions to the original form. Instead, the curvature of the bearing surface obtained by simple computations on the measurement data is analysed and the edge of the wear region is recognized by its deviation in curvature. The method is applied to a retrieved Metal-on-Metal prosthetic head and the results are compared to those of the well-known method introduced by Jaeger et al., in 2013. With the new approach the wear region is identified more accurately.

The Rise of the Direct Anterior Approach: Trends, Learning Curves, and Patient Characteristics of 63,182 Primary Total Hip Arthroplasties in the Dutch Arthroplasty Register (LROI)

BACKGROUND

The use of the direct anterior approach (DAA) in total hip arthroplasty (THA) has steadily increased in the Netherlands since 2007. The aim of this study was to outline how the DAA has been implemented in the Netherlands. Moreover, we investigated the learning curve of the DAA at a hospital level, and explored patient characteristics of the DAA compared with other approaches and during the learning phase after implementing the DAA.

METHODS

In this population-based cohort study, we included all primary THAs between 2007 and 2020 (n = 342,473) from the Dutch Arthroplasty Register. For hospitals implementing the DAA (n > 20), patients were categorized in 4 experience groups using the date of surgery: 1 to 50, 51 to 100, 101 to 150, or > 150. Subsequently, data from different hospitals were pooled and survival rates were calculated using Kaplan-Meier survival analyses. Adjusted revision rates were calculated using mixed Cox proportional hazard models (frailty).

RESULTS

The use of the DAA gradually rose from 0.2% in 2007 to 41% of all primary THAs in 2020. A total of 64 (56%) hospitals implemented the DAA. However, not all hospitals continued using this approach. After implementation, the 5-year survival rate for the first 50 procedures was significantly lower (96% confidence interval [CI] 95.8 to 97.2) compared to >150 procedures (98% CI 97.7 to 98.1). Multivariable Cox hazard analyses demonstrated a higher risk of revision during the first 50 procedures compared with >150 procedures (hazard ratio 1.6, CI 1.3 to 2.0).

CONCLUSIONS

The use of DAA for primary THA significantly increased. For hospitals implementing DAA, a considerable learning curve with increased revision risk was seen.

A comparison of cemented femoral fixation via anterior versus posterior approach total hip arthroplasty: an analysis of 60,739 total hip arthroplasties

BACKGROUND

Anterior approach total hip arthroplasty (THA) decreases the rate of dislocation but increases femoral-sided complications in the way of periprosthetic fractures and component loosening. A cemented prosthesis may reduce femoral-sided complications and improve the risk:benefit profile of anterior approach THA.

METHODS

Data from the Australian National Joint Replacement Registry were analysed for patients undergoing primary THA via the anterior or posterior approach using a cemented polished femoral stem from January 2015 to December 2021. The primary outcome measure was the cumulative percent revision (CPR) for all causes and CPR for femoral component loosening and fracture. The CPR for the primary outcome measures were compared between the anterior and posterior approach and adjusted for age, sex, ASA score, BMI and femoral head size.

RESULTS

The study included 60,739 THAs with cemented stems (10,742 anterior, 49,997 posterior). The rate of revision of the anterior versus the posterior approach did not significantly differ (HR 0.87 (95% CI, 0.74-1.03), p = 0.100). Anterior approach THA had a significantly higher rate of revision for femoral component loosening (HR 5.06 [95% CI, 3.08-8.30], p < 0.001); and a decreased rate of revision for infection (HR 0.59 [95% CI, 0.43-0.81], p = 0.001) and dislocation/instability (HR 0-3 months 0.48 [95% CI, 0.27-0.83], p = 0.008; HR >3 months 0.30 [95% CI, 0.15-0.61], p < 0.001). There was no difference in the rate of revision surgery for fracture between the 2 approaches (HR 1.01 [95% CI, 0.71-1.43]), p = 0.975).

CONCLUSIONS

There is no significant difference in overall revision rates with cemented femoral fixation performed with an anterior or posterior approach. Cemented fixation performed with the anterior approach partly mitigates femoral complications with no difference in the revision rate for fracture but an increased rate of femoral component loosening.

A Randomized Clinical Trial of Direct Anterior Versus Mini-Posterior Total Hip Arthroplasty: Small, Early Functional Differences Did Not Lead to Meaningful Clinical Differences at 7.5 Years

BACKGROUND

Our previously reported randomized clinical trial of direct anterior approach (DAA) versus mini-posterior approach (MPA) total hip arthroplasty showed slightly faster initial recovery for patients who had a DAA and no differences in complications or clinical or radiographic outcomes beyond 8 weeks. The aims of the current study were to determine if early advantages of DAA led to meaningful clinical differences beyond 5 years and to identify differences in midterm complications.

METHODS

Of the 101 original patients, 93 were eligible for follow-up at a mean of 7.5 years (range, 2.1 to 10). Clinical outcomes were compared with Harris Hip, 12-Item Short Form Health Survey, and Hip Disability and Osteoarthritis Outcomes Scores (HOOS) scores and subscores, complications, reoperations, and revisions.

RESULTS

Harris Hip scores were similar (95.3 ± 6.0 versus 93.5 ± 10.3 for DAA and MPA, respectively, P = .79). The 12-Item Short Form Health Survey physical and mental scores were similar (46.2 ± 9.3 versus 46.2 ± 10.6, P = .79, and 52.3 ± 7.1 versus 55.2 ± 4.5, P = .07 in the DAA and MPA groups, respectively). The HOOS scores were similar (97.4 ± 7.9 versus 96.3 ± 6.7 for DAA and MPA, respectively, P = .07). The HOOS quality of life subscores were 96.9 ± 10.8 versus 92.3 ± 16.0 for DAA and MPA, respectively (P = .046). No clinical outcome met the minimally clinically important difference. There were 4 surgical complications in the DAA group (1 femoral loosening requiring revision, 1 dislocation treated closed, and 2 wound dehiscences requiring debridement), and 6 surgical complications in the MPA group (3 dislocations, 2 treated closed, and 1 revised to dual mobility; 2 intraoperative fractures treated with a cable; and 1 wound dehiscence treated nonoperatively).

CONCLUSIONS

At a mean of 7.5 years, this randomized clinical trial demonstrated no clinically meaningful differences in outcomes, complications, reoperations, or revisions between DAA and MPA total hip arthroplasty.

LEVEL OF EVIDENCE

IV.

No Difference in Revision Rates or Patient-Reported Outcome Measures Between Surgical Approaches for Total Hip Arthroplasty Performed for Femoral Neck Fracture: An Analysis of 5,025 Primary Total Hip Arthroplasties From the New Zealand Joint Registry

BACKGROUND

Total hip arthroplasty (THA) for femoral neck fracture (FNF) can be performed through different surgical approaches. This study compared the revision rates and patient-reported outcome measures by surgical approach.

METHODS

Data from the New Zealand Joint Registry were analyzed for patients undergoing primary THA for FNF from January 2000 to December 2021. A total of 5,025 THAs were performed for FNF; the lateral approach was used in 2,499 (49.7%), the posterior in 2,255 (44.9%), and the anterior in 271 (4.3%). The primary outcome measure was the all-cause revision rate. Secondary outcome measures included revision rates for: dislocation, aseptic femoral component loosening, periprosthetic fracture, and infection. Oxford Hip Scores (OHS) were also collected. Age, sex, body mass index, American Society of Anesthesiologists score, femoral head size, dual mobility use, femoral fixation, and surgeon experience were assessed as potential confounding variables.

RESULTS

There was no difference in the revision rates between lateral and posterior (P = .156), lateral and anterior (P = .680), or posterior and anterior (P = .714) approaches. There was no difference in the reasons for revision between the lateral and posterior approaches or 6-month OHS (P = .712). There was insufficient data to compare the anterior approach.

CONCLUSIONS

There is no difference in the overall revision rates, reasons for revision, or OHS between the lateral and posterior surgical approaches for THA performed for FNF. Insufficient data on the anterior approach is available for an accurate comparison.

LEVEL OF EVIDENCE

Level III.

Radiographic study of direct anterior approach hip arthroplasty: a 10-15 year follow-up of Chinese patients

BACKGROUND

Controversy remains over whether different surgical approaches exert an impact on the component positioning in total hip arthroplasty. We conducted a retrospective study to reveal the long-term position of prostheses in the first group of patients in China who underwent direct anterior hip arthroplasty.

METHODS

Collected were data from 350 patients who underwent direct anterior hip arthroplasty between 2008 and 2013, including demographic information, imaging data, Harris hip scores, and surgical complications. Variables, measured radiographically or by CT, included hip offset, leg length discrepancy, component position, and stability within one week after surgery and at the last follow-up. The data were subjected to statistical analysis by using paired t-tests and Pearson chi-square tests.

RESULTS

Data were harvested by follow-up and self-reported questionnaires. The postoperative follow-up lasted for 13.1 years on average (minimum, 10 years; maximum, 15 years), and the overall survival rate of hip prostheses was 96.3%. The mean Harris score at the final follow-up was 91.8 points. After excluding patients with significant preoperative hip deformities, the incidence of postoperative limb inequality (> 5 mm) was 4.9% at the last follow-up, and the incidence of hip offset discrepancy (> 5 mm) was 14.6%. The overall proportion of the acetabular components located in the Lewinnek safe zone was 77.7%, whereas the proportion of femoral prostheses in the safe zone (< 3° inclination) was 94.0%. Based on the revised data and the last follow-up imaging, the total proportion of acetabular and femoral prostheses with a radiolucence of > 2 mm was 5.1%.

CONCLUSION

Direct anterior approach hip arthroplasty could achieve excellent component positioning and long-term prosthesis survival in patients without severe hip deformities.

Mid-term results of cemented hip arthroplasties through the direct anterior approach in the lateral decubitus position: a retrospective cohort study

BACKGROUND

Reports show a high complication rate when starting with the Direct Anterior Approach (DAA) in a supine position for hip arthroplasty. The DAA with the patient in lateral decubitus position may avoid this problem because it supposedly provides better visibility, especially on the femoral side. However, this approach did show a rather high complication rate during the adoption of the approach at 1 year follow up in our previous report. We were interested what the overall 7 year survival estimate would be and whether improvement could be seen with growing experience.

METHODS

A cohort of patients undergoing total hip arthroplasty right from the start of applying the DAA in lateral decubitus position was analysed.

RESULTS

In total 175 hip prostheses (162 patients) were evaluated. The 7-year survival estimate was 95.1%, 95 CI: 91.8-98.4%. In 6 of 8 revisions there was aseptic loosening of the stem. By dividing the cohort into 3 consecutive groups in time we did not see a significantly improving revision rate.

CONCLUSIONS

In our experience, the adoption of the direct anterior approach in lateral decubitus position caused a relatively low 7-year survival estimate without an apparent decrease with growing experience, however given the low number of cases further research is needed to investigate the long-term risk of adopting a new approach.

Dislocation Following Anterior and Posterior Total Hip Arthroplasty in the Setting of Spinal Deformity and Stiffness: Evolving Trends Using a High-Risk Protocol at a Single Tertiary Center

BACKGROUND

Patients who have spinal stiffness and deformity are at the highest risk for dislocation after total hip arthroplasty (THA). Previous reports of this cohort are limited to antero-lateral and postero-lateral (PL) approaches. We investigated the dislocation rate after direct anterior (DA) and PL approach THA with a contemporary high-risk protocol to optimize stability.

METHODS

We investigated patients undergoing THA who had preoperative biplanar imaging from January-December 2019. Patients were identified using radiographic criteria of spinal-stiffness (<10-degree change in sacral slope from standing to seated) and deformity (flatback deformity with >10-degree difference in pelvic incidence and lumbar lordosis). There were 367 patients identified (181 DA, 186 PL). The primary outcome was dislocation rate at 2-years postoperatively. Risk-factors for dislocation were evaluated using logistic regressions (significance level of 0.05).

RESULTS

There were 6 (1.6%) dislocations in the entire cohort, with low dislocation rates for both DA (0.6%) and PL-THA (2.7%). We observed increased utilization of dual mobility with larger outer head bearings (>38 mm) with PL-THA (34.4 versus 5.0%, P < .01) and conversely increased utilization of 32-mm femoral-heads with DA-THA (39.4 versus 7.0%, P < .001). Surgical approach (PL) was not a significant risk-factor for dislocation (odds ratio: 5.03, P = .15). Patients who had a history of lumbar-fusion had 8-times higher odds for dislocation (OR: 8.20, P = .020).

CONCLUSIONS

To the best of our knowledge, this is the largest series to date evaluating DA and PL-THA in the hip-spine 2B-group. Our results demonstrate lower dislocation rate than expected with either surgical approach using a high-risk protocol.

Clinical application of artificial intelligence-assisted three-dimensional planning in direct anterior approach hip arthroplasty

PURPOSE

The objective of this study was to investigate the efficacy of an artificial intelligence-assisted 3D planning system (AIHIP) in total hip arthroplasty by direct anterior approach and assess the reliability of the AIHIP preoperative program in terms of both interobserver and intraobserver agreement.

METHODS

A retrospective analysis was conducted on patients who underwent unilateral primary THA via direct anterior approach from June 2019 to March 2022. Participants were randomly assigned to receive either the AIHIP system (n = 220) or the 2D template (control group) (n = 220) for preoperative planning. The primary outcome aimed to evaluate the correspondence between the prosthesis selected intro-operation and the one planned preoperatively, as well as to calculate the intraclass correlation coefficient (ICC). Secondary outcomes included operation time, intraoperative blood loss, fluoroscopy times, Harris hip score (HHS), lower limb length difference (LLD), femoral offset (FO), and bilateral femoral offset difference.

RESULTS

No significant differences were observed in gender, age, body mass index (BMI), aetiology, and American Society of Anesthesiologists (ASA) score between the two groups. Both planning methods exhibited good intraobserver agreement for component planning (ICC: 0.941-0.976). Interobserver agreement for component planning was comparable between the two methods (ICC: 0.882-0.929). In the AIHIP group, the accuracy of acetabular cup and femoral stem prosthetics planning significantly improved, with accuracies within the size range of ± 0 and ± 1 being 76.8% and 90.5% and 79.5% and 95.5%, respectively. All differences between two groups were statistically significant (p < 0.05). Patients receiving AIHIP preoperative planning experienced shorter operation times, reduced intraoperative blood loss, fewer fluoroscopy times, and lower leg length discrepancy (LLD) (p < 0.05). Moreover, they demonstrated a higher Harris hip score (HHS) at three days post-surgery (p < 0.05). However, no significant differences were found in femoral offset (FO), difference of bilateral femoral offsets, and HHS at 1 month after the operation.

CONCLUSION

Utilizing AIHIP for preoperative planning of direct anterior approach THA can significantly enhance the accuracy of prosthetic sizing with good reliability, decrease operation time, reduce intraoperative blood loss, and more effectively restore the length of both lower limbs. This approach has greater clinical application value.

Risk factors for intraoperative femoral fractures in cementless bipolar hip arthroplasty for femoral neck fracture in multicenter: The TRON group study

BACKGROUND

Intraoperative femoral fractures are more common in cementless bipolar hip arthroplasty (BHA) for displaced femoral neck fractures than they are in cemented BHA and remain one of the major concerns. This study aimed to investigate the risk factors for intraoperative femoral fractures in cementless BHA.

METHODS

The study included 1,392 patients who underwent cementless BHA for displaced femoral neck fractures from January 2015 to December 2019 in 14 hospitals of the Trauma Research Group. They were divided into two groups according to the presence or absence of intraoperative femoral fractures, and factors associated with intraoperative fractures were statistically examined.

RESULTS

Forty (2.9 %) intraoperative and 28 (2.0 %) postoperative, totally 68 (4.9 %) femoral fractures occurred. The mean age of the patients, presence of opposite-side proximal femoral fracture, approach, and cementless stem design were significantly different between the two groups (P < 0.05). The logistic regression analysis model showed that a fully HA-coated stem (odds ratio, 4.12; 95 % confidence interval, 1.43-11.9) was an independent factor associated with intraoperative femoral fractures.

CONCLUSION

This study investigated the risk factors associated with intraoperative fractures and showed that fully HA-coated stems were an independent factor associated with intraoperative femoral fractures. Surgeons should be cautious in the early stages of introducing fully HA-coated stems.

The Impact of Surgical Approach on 90-Day Prosthetic Joint Infection After Total Hip Replacement - A Population-Based, Propensity Score-Matched Cohort Study

BACKGROUND

Prosthetic joint infection (PJI) is a devastating complication of total hip arthroplasty (THA). This study aimed to determine if the anterior approach (AP) influenced the incidence of early PJI in THA compared to posterior approach (PP).

METHODS

Record linkage was performed between state-wide hospitalization data and a national joint replacement registry to identify unilateral THA performed via the AP or PP. Complete data on 12,605 AP and 25,569 PP THAs were obtained. Propensity score matching (PSM) was undertaken to match covariates between the approaches. Outcomes were the 90-day PJI hospital readmission rate(using narrow and broad definitions) and 90-day PJI revision rate (defined as component removal or exchange).

RESULTS

The raw PJI readmission rate for AP was lower than PP (0.8% versus 1.1%, respectively). In the PSM analysis, there was no statistically significant difference in PJI readmission rate between approaches using narrow or broad definition of PJI readmission. In terms of revision for infection, both methods showed AP had a significantly lower rate than PP, with an adjusted odds ratio (OR) of 0.47 (95% confidence interval (CI) 0.30, 0.75) for the 1:1 nearest neighbor method and 0.50 (95% CI 0.32, 0.77) for the subclassification method.

CONCLUSION

After addressing known confounders, there was no significant difference in the 90-day hospital readmission rate for hip PJI between approaches. There was a significantly reduced 90-day PJI revision rate for AP. The difference in revision may reflect differences in the surgical management of PJI between hip approaches rather than a difference in the underlying rate of infection.

Proximal radiolucent lines around fully hydroxyapatite-coated tapered femoral stems: should we be concerned?

INTRODUCTION

Radiolucent lines occasionally develop around the proximal aspect of fully hydroxyapatite (HA)-coated tapered femoral stems after total hip arthroplasty (THA). It was hypothesised that distal wedging of stems may predispose to proximal radiolucent line formation, which may negatively impact clinical outcome.

METHODS

All primary THA performed with a collarless fully HA-coated stem that had a minimum of 1 year of radiographic follow-up were identified in a surgical database (n = 244). Radiographic measures of proximal femoral morphology and femoral canal fill at the middle and distal thirds of the stem were analysed for association with the presence of proximal radiolucent lines. Linear regression was used to explore any association between radiolucent lines and patient reported outcome measures (PROMs), available in 61% of patients.

RESULTS

Proximal radiolucent lines developed in 31 cases (12.7%) at final follow-up. Dorr A femoral morphology and increased canal-fill at the distal ⅓ of the stem correlated with the development of radiolucent lines (p < 0.001). No correlation was observed between pain or PROMs and the presence of proximal radiolucent lines.

DISCUSSION

We observed an unexpectedly high incidence of proximal femoral radiolucent lines about collarless fully HA coated stems. Distal-only implant wedging in Dorr A bone may compromise proximal fixation. Although this finding did not correlate with short-term outcomes, the long-term clinical impact requires further study.

Does Time to Aseptic Failure After Primary Total Hip Arthroplasty Affect Clinical and Patient-Reported Outcomes?

BACKGROUND

Evidence on the effects of time-to-failure from primary total hip arthroplasty (THA) to aseptic first-revision on clinical results and patient-reported outcome measures (PROMs) is scarce. Therefore, we sought to compare demographics, operative times, lengths of stay, discharge dispositions, 90-day readmissions, re-revision rates, mortalities, and PROMs between early and late aseptic THA revisions.

METHODS

This study is a retrospective review of a prospectively collected institutional database of all elective hip procedures. In total, 572 patients who underwent aseptic revision after primary THA from August 2015 to December 2018 were analyzed. Patients were stratified into either early revision (<3-years; n = 176) or late revision (≥3-years; n = 396) cohorts.

RESULTS

Significantly more patients were revised earlier for bone-related (ie, periprosthetic fractures) (22.7% versus 8.3%) or other various complications (19.9% versus 5.8%), whereas more late revisions were performed to treat implant-related failures (6.8% versus 37.1%), respectively. Operative time was significantly shorter in early versus late revisions (133 versus 157 minutes). A significantly higher delta-change/improvement from baseline/preoperative to 1-year postoperative was found for hip disability and osteoarthritis outcome score physical function (HOOS-PS), veterans-RAND-12 physical and mental components (VR-12-PCS and MCS, respectively) of early revisions. However, HOOS-PS and HOOS-Pain at 1-year of follow-up were significantly worse in early revisions.

CONCLUSION

With exception of operative time, time-to-failure had no significant influence on clinical results. Despite greater improvements on PROMs from preoperative to postoperative, patients undergoing early revisions after primary THA perceive significantly higher levels of pain and worse physical functionality at 1-year of follow-up.

Periprosthetic fracture following anterior approach or dislocation after posterior approach: which one is the lesser evil?

INTRODUCTION

The most common approaches in total hip arthroplasty (THA) have different complication profiles; anterior-approach (AA-THA) has an increased risk of periprosthetic fractures (PPF); posterior-approach (PA-THA) is associated with higher dislocation risk. However, the relative severity of one versus the other is unknown. This study aims to compare outcome of patients who suffered PPF after AA-THA with those that sustained dislocation after PA-THA.

METHODS

This is a retrospective, single-center, multi-surgeon, consecutive case-series of primary THA patients. In a cohort of 9867 patients who underwent THA, 79 fulfilled the approach-specific, post-operative complication criteria, of which 44 were PPF after AA-THA and 35 with dislocation after PA-THA (age 67.9 years (range: 38.0-88.1), 58.2% women). Outcome included complication- and revision- rates, and patient-reported outcomes including Oxford Hip Score (OHS).

RESULTS

At 5.8 years follow-up (range: 2.0-18.5), reoperation was more common in the dislocation after PA-THA group (23/35 vs. 20/44; p = 0.072). Change of surgical approach occurred in 15/20 of patients with PPF after AA-THA, but none in those with dislocation after PA-THA. Following re-operation, complication rate was greater in the PPF group (9/20 vs. 4/23; p = 0.049). At latest follow-up, OHS were superior in the PPF after AA-THA group [42.6 (range: 25.0-48.0) vs. 36.6 (range: 21.0-47.0); p = 0.006].

CONCLUSION

Dislocation following PA-THA is more likely to require revision. However, PPF following AA-THA requires more often a different surgical approach and is at higher risk of complications. Despite the increased surgical burden post-operative PROMs are better in the peri-prosthetic fracture group, especially in cases not requiring reoperation.

LEVEL OF EVIDENCE

III, case-control study.

Direct Anterior Approach Total Hip Arthroplasty Is Associated With Reduced 1-Year Mortality and Surgical Complications After Femoral Neck Fracture

BACKGROUND

In some studies, the direct anterior approach (DAA) for elective total hip arthroplasty (THA) is associated with decreased dislocation and greater functional gains compared to the posterior approach (PA), as well as higher functional outcomes compared to the direct lateral approach (LA) at 2 weeks postoperatively. Given the paucity of literature on femoral neck fracture (FNF), we aspired to determine the association between the surgical approach used in THA and outcomes.

METHODS

We conducted a retrospective review of patients undergoing THA for FNF at 9 institutions from 2010 to 2019. Patients who had high-energy injury mechanisms, were nonambulatory prior to injury, had concomitant femoral head or acetabular fractures, or did not reach minimum 1-year follow-up were excluded. The study included 622 THAs, of which 348 (56%) were performed through a DAA, 197 (32%) through a PA, and 77 (12%) through an LA. Postoperative complications and mortalities at 90 days and 1 year were compared between groups. Multivariable logistic regression models were constructed for each outcome of interest.

RESULTS

The DAA was associated with a decreased risk of 90-day dislocation (odds ratio [OR] 0.25; 95% confidence interval [CI] 0.10 to 0.62; P = .01), mechanical revision (OR 0.12; 95% CI 0.02 to 0.56; P = .01), and mortality (OR 0.38; 95% CI 0.16 to 0.91; P = .03) compared to the PA. The DAA was also associated with decreased risk of dislocation (OR 0.32; 95% CI 0.14 to 0.74; P = .01), mechanical revision (OR 0.22; 95% CI 0.08 to 0.65; P = .01), and mortality at 1 year compared to PA (OR 0.43; 95% CI 0.21 to 0.85; P = .02).

CONCLUSION

The DAA for THA after FNF is associated with higher in-hospital medical complications but lower risks of postoperative reoperation and mortality. Postdischarge care may impact this association and needs to be addressed in future studies. The DAA should be used among surgeons experienced with the approach for FNF to minimize complications.

LEVEL OF EVIDENCE

Retrospective cohort, Level III.

Early Practice All-Cause Complications for Fellowship-Trained Anterior Hip Surgeons Are Not Increased When Compared to "Gold Standard" Experienced Posterior Approach Surgeons

BACKGROUND

Increased complication rates have been reported during the learning curve for direct anterior approach (DAA) total hip arthroplasty (THA). However, emerging literature suggests that complications associated with the learning curve may be substantially reduced with fellowship training.

METHODS

Our institutional database was queried to identify 2 groups: (1) 600 THAs comprised of the first 300 consecutive cases performed by 2 DAA fellowship-trained surgeons; and (2) 600 posterolateral approach (PA) THAs, including the most recent 300 primary cases performed by 2 experienced PA surgeons. All-cause complications, revision rates, reoperations, operative times, and transfusion rates were evaluated.

RESULTS

Comparing DAA and PA cases, there were no significant differences in rates of all-cause complications (DAA = 18, 3.0% versus PA = 23, 3.8%; P = .43), periprosthetic fractures (DAA = 5, 0.8% versus PA = 10, 1.7%; P = .19), wound complications (DAA = 7, 1.2% versus PA = 2, 0.3%; P = .09), dislocations (DAA = 2, 0.3% versus PA = 8, 1.3%, P = .06), or revisions (DAA = 2, 0.3% versus PL = 5, 0.8%; P = .45) at 120 days postoperatively. There were 4 patients who required reoperation for wound complications, all within the DAA group (DAA = 4, 0.67% versus PA = 0; P = .045). Operative times were shorter in the DAA group (DAA <1.5 hours = 93% versus PA <1.5 hours = 86%; P < .01). No blood transfusions were given in either group.

CONCLUSION

In this retrospective study, DAA THAs performed by fellowship-trained surgeons early in practice were not associated with higher complication rates compared to THAs performed by experienced PA surgeons. These results suggest that fellowship training may allow DAA surgeons to complete their learning curve period with complication rates similar to experienced PA surgeons.

Direct Anterior Versus Posterior Approach for Total Hip Arthroplasty Performed for Displaced Femoral Neck Fractures

OBJECTIVES

To compare perioperative, 90-day, and 1-year postoperative complications and outcomes between the direct anterior approach (DAA) and the posterior approach for total hip arthroplasty in geriatric patients with displaced femoral neck fractures (FNFs).

DESIGN

Retrospective cohort study.

SETTING

Multicenter Health care Consortium.

PATIENTS

Seven-hundred and nine patients 60 years or older with acute displaced FNFs between 2009 and 2021.

INTERVENTION

Total hip arthroplasty using either DAA or posterior approach.

MAIN OUTCOME MEASUREMENTS

Rates of postoperative complications including dislocations, reoperations, and mortality at 90 days and 1 year postoperatively. Secondary outcome measures included ambulation capacity at discharge, ambulation distance with inpatient physical therapy, discharge disposition, and narcotic prescription quantities (morphine milligram equivalents).

RESULTS

Through a multivariable regression analysis, DAA was associated with significantly shorter operative time ( B = -6.89 minutes; 95% confidence interval [CI] -12.84 to -0.93; P = 0.024), lower likelihood of blood transfusion during the index hospital stay (adjusted odds ratios = 0.54; 95% CI 0.27 to 0.96; P = 0.045), and decreased average narcotic prescription amounts at 90 days (B = -230.45 morphine milligram equivalents; 95% CI -440.24 to -78.66; P = 0.035) postoperatively. There were no significant differences in medical complications, dislocations, reoperations, and mortality at 90 days and 1 year postoperatively.

CONCLUSION

When comparing the DAA versus posterior approach for total hip arthroplasty performed for displaced FNF, DAA was associated with shorter operative time, lower likelihood of blood transfusion, and lower 90-day postoperative narcotic prescription amounts.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Selective THA-approach use amongst junior surgeons improves safety of introducing the anterior approach: a prospective, multi-surgeon, comparative, study

BACKGROUND

Learning curves associated with independent practice and anterior approach total hip arthroplasty (AA-THA) has been associated with inferior outcome. This study compared outcome of junior, fellowship-trained, surgeons who perform THA through both anterior and posterior (PA) approach, with senior surgeons who perform either AA or PA, to determine whether: 1. Fellowship training and selective practice allows for safe introduction of AA into practice; and 2. Whether selective approach-use influences outcome.

METHODS

This is a prospective, consecutive study comparing the first 800 THAs of two junior, dual-approach, surgeons (AA/PA: 455/345), with 400 THAs cases of two senior, single-approach, surgeons (AA/PA: 200/200), between 2018 and 2020. Most patients were female (54.4%), mean age was 65 years-old (range 19-96) and mean BMI was 29 kg/m2 (range 16-66). Outcome included radiologic measurements (inclination/anteversion and leg-length), complication- and revision rates, and patient-reported outcomes including Oxford Hip Score (OHS).

RESULTS

At 3.1 years (range 2.0-6.8) follow-up, there were 43 complications (3.6%), including 27 re-operations (2.3%); with no difference between junior and senior surgeons for AA-THA (Junior: 8/455 vs. Senior: 3/200; p = 0.355) or PA-THA (Junior: 11/345 vs. Senior: 5/200; p = 0.400). Amongst juniors, there was no difference in complications (AA:8/455 vs. PA:11/345; p = 0.140) and in ΔOHS (AA:20.5 ± 7.7 vs. PA:20.5 ± 8.0; p = 0.581) between approaches.

CONCLUSION

Contemporary training and selective approach-use minimizes the learning curve, allowing junior staff to have equivalent outcome to established, senior surgeons in both AA and PA. We would advocate for selective approach use amongst junior arthroplasty surgeons when introducing the AA into independent practice.

Surgical approach had minor association with femoral stem migration in total hip arthroplasty: radiostereometric analysis of 61 patients after 5-year follow-up

BACKGROUND AND PURPOSE

Total hip arthroplasty (THA) is usually performed using 1 of 3 surgical approaches: direct lateral (DLA), posterior (PA), or anterior (AA). AA is different from DLA and PA owing to limited intraoperative visibility of the femoral canal. This could affect stem positioning and therefore migration. We aimed to perform an exploratory radiostereometric analysis (RSA) study with 3 groups for surgical approach assessing stem migration up to 5 years postoperatively.

PATIENTS AND METHODS

61 patients with unilateral osteoarthritis of the hip were included. 21 patients were allocated to the DLA, 20 to the PA, and 20 to the AA group. All patients received an uncemented, collarless, double-tapered, fully hydroxyapatite-coated Profemur Gladiator stem. Migration was measured with model-based RSA. Baseline RSA was on day 1 postoperatively. The follow-ups were at day 8, at 5 weeks, and at 3, 6, 12, 24, and 60 months after surgery. Generalized linear mixed models were used to analyze maximum total point motion (MTPM) migrations.

RESULTS

Group mean differences in MTPM were 0.4 mm (95% confidence interval [CI] -1.5 to 2.4) for DLA vs. PA, 1.1 mm (CI -1.0 to 3.3) for AA vs. DLA, and 1.6 mm (CI -0.8 to 3.9) for AA vs. PA, when adjusted for sex and age as covariates. 2 stems in the AA group had excessive early migration. For all stems the migrations occurred mainly within 5-week follow-up and then stabilized.

CONCLUSION

At 5-year follow-up, there were no statistically significant differences in stem migration associated with the 3 surgical approaches used in this study.

Do 'Surgeon Champions' and High-Volume Surgeons Have Lower Rates of Periprosthetic Femur Fracture? Perspective from a State-wide Quality Improvement Registry

BACKGROUND

Recently, a state-wide registry identified fracture as a major cause of total hip arthroplasty revision. There were 52.8% of revisions occurring within 6 months (fracture leading cause). Registry sites have a 'Surgeon Champion' who acts as liaison and advocate. This study evaluated the effect of surgeon volume and role of 'surgeon champion' on fracture rates.

METHODS

There were 95,948 cases from 2012 to 2019 queried with peri-implant femoral fractures identified (within 6 months). Funnel plots were generated to compare individual surgeon-specific fracture rates. Surgeons who had a fracture rate below the confidence interval were labeled 'green' (lower than mean), within were 'yellow' (no difference), and above were 'red' (significantly higher).

RESULTS

For all surgeons, 19.6% were red, 72.1% yellow, and 8.3% green. There were 17.2% 'Surgeon Champions' and 6.2% 'Non-Champions' that were green (P=0.01), while 20.7 and 19.3% were red (P=0.82). There was a significant association between volume and performance (P<0.01). No surgeons in the lower two quartiles (<84; 84 to 180 cases), while 4 and 29% of higher-volume surgeons (181 to 404; >404 cases) were green. There was no statistical difference in red status by volume (P=0.53).

CONCLUSION

'Surgeon champions' and high-volume surgeons were more likely to be high performers, but not less-likely to be low performers. Active involvement in quality improvement and/or high-volume was associated with better outcomes, but did not impart complication immunity. 'Green' surgeons should mentor colleagues to help reduce fractures by re-evaluating modifiable factors. Analyzing outcomes to promote quality and decrease complications is paramount.

Penalty for Switching Implants? Assessing the Learning Curve With a Collarless, Tapered Wedge Cementless Femoral Component

Background

Surgeon learning curve associated with a tapered wedge femoral implant as measured by early femoral component subsidence and 90-day risk of reoperation was evaluated.

Methods

The first 451 patients undergoing primary, cementless total hip arthroplasty by a single, fellowship-trained arthroplasty surgeon with a tapered wedge stem design were retrospectively reviewed. Early radiographic femoral component subsidence during the first 6 weeks postoperatively and 90-day reoperations was recorded.

Results

When stratified by approach, there was no association between date of surgery and femoral component subsidence in the posterior approach (P-value for linear trend over time = 0.44). In the direct anterior approach, there was a significant association between date of surgery and early femoral component subsidence (P-value for linear trend over time = 0.01). For both approaches, there was an increase in implanted stem size relative to templated stem size over time (P < .01 and P = .03, respectively). There was no association between the date of surgery and risk of 90-day reoperation (P = .45).

Conclusions

In a single surgeon's initial use of a tapered cementless wedge stem, early femoral component subsidence was not impacted by the surgeon's learning curve when the posterior approach was utilized. Although subsidence was associated with date of surgery in the direct anterior cohort, this was not associated with increased risk of 90-day reoperation. Should a surgeon adopt a new tapered-wedge stem, these findings suggest that the stem is forgiving both in relation to subsidence and 90-day reoperation risk when appropriate surgical technique is utilized.

Comparing dislocation rates by approach following elective primary dual mobility total hip arthroplasty: a systematic review

BACKGROUND

Dual mobility components can be implanted during total hip arthroplasty (THA) for primary osteoarthritis via a direct anterior approach (DAA), anterolateral approach (ALA), direct lateral approach (DLA), or posterior/posterolateral approach (PLA). This review compares dual mobility hip dislocation rates using these approaches for elective primary THA.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for articles published after January 1, 2006 that reported dislocation rates for adult patients after primary THA with dual mobility implants. Articles were excluded if they reported revision procedures, nonelective THA for femoral neck fractures, acetabular defects requiring supplemental implants, prior surgery, or ≤ 5 patients. The primary outcome was hip dislocation rate. Secondary outcomes included infection, Harris Hip Score (HHS), and Postel-Merle d'Aubigné (PMA) score.

RESULTS

After screening 542 articles, 63 met inclusion criteria. Due to study heterogeneity, we did not perform a meta-analysis. Eight studies reported DAA, 5 reported ALA, 6 reported the DLA, and 56 reported PLA. Study size ranged from 41 to 2,601 patients. Mean follow-up time ranged from 6 months to 25 years. Rates of infection and dislocation were low; 80% of ALA, 87.5% of DAA, 100% of DLA, and 82.1% of PLA studies reported zero postoperative dislocations. Studies reporting postoperative HHS and PMA scores showed considerable improvement for all approaches.

CONCLUSIONS

Patients undergoing primary THA with dual mobility implants rarely experience postoperative dislocation, regardless of surgical approach. Additional studies directly comparing DAA, ALA, DLA, and PLA are needed to confirm these findings.

Large Femoral Heads and Select Dual-Mobility Bearings Are Associated With Reduced Instability in Contemporary Posterior Approach Total Hip Arthroplasty

BACKGROUND

Postoperative dislocation is considered the main drawback of posterior approach total hip arthroplasty (THA). Thinner highly cross-linked polyethylene and dual-mobility bearings allow maximizing femoral head diameter per a given cup size. This study evaluated dislocation rates as large femoral head bearings were introduced into a practice over an 11-year period.

METHODS

A total of 1,511 consecutive primary THAs were retrospectively reviewed. Demographics, implant sizes, femoral head-acetabular cup ratio, and dislocation status were collected from the electronic medical record. Data were evaluated using time series analysis techniques as larger femoral heads, thinner polyethylene liners, and dual-mobility bearings were introduced. The cohort was 57% women with mean age and body mass index of 62 years (range, 13 to 93) and 31 kg/m² (range, 13 to 54), respectively.

RESULTS

The overall dislocation rate was 0.98%. Use of femoral head sizes ≥ 40 millimeters increased from 4% in the years 2010 to 2016 to 51% in the years 2017 to 2021, correlating with a 50% reduction in dislocation rate from 1.4% to 0.7% (P = .279). Also, no dislocations occurred in patients who had dual-mobility bearings or ≥ 40-millimeter femoral heads (P = .007). Twelve of 14 dislocations occurred in cases with head-cup ratio < 0.7 (P = .013). Thirteen of 14 dislocations were in women (P = .005).

CONCLUSION

Maximizing the femoral head diameter per given cup size correlated with a decrease in dislocation rate in modern posterior approach THA. Furthermore, these results suggest that dual-mobility articulations should be reserved for high-risk patients or patients in whom a 40-millimeter femoral head is not possible.

LEVEL OF EVIDENCE

IV-consecutive case series; no control group.

Acetabular Total Hip Arthroplasty Revision: A Summary of Operative Factors, Outcomes, and Comparison of Approaches

BACKGROUND

Revision total hip arthroplasty (THA) presents a greater risk to patients than primary THA, and surgical approach may impact outcomes. This study aimed to summarize acetabular revisions at our institution and to compare outcomes between direct anterior and posterior revision THA.

METHODS

A series of 379 acetabular revision THAs performed from January 2010 through August 2022 was retrospectively reviewed. Preoperative, perioperative, and postoperative factors were summarized for all revisions and compared between direct anterior and posterior revision THA.

RESULTS

The average time to acetabular revision THA was 10 years (range, 0.04 to 44.1), with mechanical failure (36.7%) and metallosis (25.6%) being the most prevalent reasons for revision. No differences in age, body mass index, or sex were noted between groups. Anterior revision patients had a significantly shorter length of stay (2.2 versus 3.2 days, P = .003) and rate of discharge to a skilled nursing facility (7.5 versus 25.2%, P = .008). In the 90-day postoperative period, 9.2% of patients returned to the emergency department (n = 35) and twelve patients (3.2%) experienced a dislocation. There were 13.2% (n = 50) of patients having a rerevision during the follow-up period with a significant difference between anterior and posterior approaches (3.8 versus 14.7%, respectively, P = .049).

CONCLUSION

This study provides some evidence that the anterior approach may be protective against skilled nursing facility discharge and rerevision and contributes to decreased lengths of stay. We recommend surgeons select the surgical approach for revision THA based on clinical preferences and patient factors.

Comparison of periprosthetic joint infection rates in the direct anterior approach and non-anterior approaches to primary total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Periprosthetic joint infection is a serious complication and devastating mode of failure of total hip arthroplasty. Various surgical approaches exist for total hip arthroplasty, including the increasingly popularised direct anterior approach. There is no clear consensus on which approach is least associated with periprosthetic joint infection. The objective of this meta-analysis was to compare the rate of periprosthetic joint infection between surgical approaches to primary total hip arthroplasty for osteoarthritis.

METHODS

A search of 3 electronic databases (PubMed/MEDLINE, Embase, and Cochrane Library) was conducted for relevant studies up to June 2020 with a defined list of inclusion and exclusion criteria. Randomised controlled trials and longitudinal studies reporting periprosthetic joint infection rates after primary total hip arthroplasty for osteoarthritis were included based on surgical approach. Data extraction was completed, and a meta-analysis was then performed using OpenMeta[Analyst] software.

RESULTS

A total of 24,407 hips were included for meta-analysis with an overall PJI incidence of 0.57%. The incidence rate for periprosthetic joint infection was 0.77% in the direct anterior approach group and 0.44% in the non-anterior approach group. The use of an anterior approach for a total hip arthroplasty was associated with an increased risk for periprosthetic joint infection (odds ratio = 1.404; 95% confidence interval, 0.711-2.771; p = 0.03).

CONCLUSIONS

The direct anterior approach to total hip arthroplasty may be associated with a significantly increased risk for periprosthetic joint infection compared to non-anterior approaches, even though the overall rate was still small. This should be considered by orthopedic surgeons when choosing the surgical approach.

Periprosthetic joint infection rates across primary total hip arthroplasty surgical approaches: a systematic review and meta-analysis of 653,633 procedures

INTRODUCTION

Evidence demonstrates comparable clinical outcomes across the various surgical approaches to primary total hip arthroplasty (THA). However, high-quality contemporary data regarding periprosthetic joint infection (PJI) risk between direct anterior approach (DAA) and other (THA) approaches is lacking. This systematic review and meta-analysis evaluated PJI rates reported in the literature between the DAA and other approaches.

MATERIALS AND METHODS

Five online databases were queried for all studies published from January 1st, 2000 through February 17th, 2021 that reported PJI rates between DAA and other surgical approaches. Studies reporting on primary THAs for osteoarthritis (OA) and that included PJI rates segregated by surgical approach were included. Articles reporting on revision THA, alternative THA etiologies, or minimally invasive techniques were excluded. Mantel-Haenszel (M-H) models were utilized to evaluate the pooled effect of surgical approach on infection rates. Validated risk of bias and methodological quality assessment tools were applied to each study. Multiple sensitivity analyses were conducted to evaluate the robustness of analyses.

RESULTS

28 articles reporting on 653,633 primary THAs were included. No differences were found between DAA cohorts and combined other approaches (OR: 0.95; 95% CI 0.74-1.21; p = 0.67) as well as segregated anterolateral approach cohorts (OR: 0.82, 95% CI 0.64-1.06; p = 0.13). However, DAA patients had a significantly reduced risk of infection compared to those undergoing posterior (OR: 0.66, 95% CI 0.58-0.74; p < 0.0001) and direct lateral (OR: 0.56, 95% CI 0.48-0.65; p < 0.00001) approaches.

CONCLUSION

The DAA to primary THA had comparable or lower PJI risk when compared to other contemporary approaches. The results of the most up-to-date evidence available serve to encourage adult reconstruction surgeons who have already adopted the DAA. Additionally, orthopaedic surgeons considering adoption or use of the direct anterior approach for other reasons should not be dissuaded over theoretical concern for a general increase in the risk of PJI.

LEVEL OF EVIDENCE

Level III.

Intraoperative Imaging in Total Hip Arthroplasty Is Cost-Effective Regardless of Surgical Approach

BACKGROUND

Component positioning in total hip arthroplasty (THA) may be improved with utilization of intraoperative imaging. The purpose of this study is to determine if intraoperative imaging during THA is cost-effective.

METHODS

A break-even analysis was used as a model for cost-effectiveness, which incorporates cost of imaging (including direct charges and the additional time required for imaging), rate of revision surgery, and cost of revision surgery, yielding a final revision rate that needs to be achieved with use of intraoperative imaging in order for its use to be cost-effective. Absolute risk reduction (ARR) is determined by the difference between the initial revision rate and final revision rate.

RESULTS

At an anticipated institutional cost of $120 and requiring 4 additional minutes, intraoperative fluoroscopy would be cost-effective if the baseline rate of revision due to component mispositioning (0.62%) is reduced to 0.46%. Intraoperative flat plate radiographs ($127) are cost-effective at an ARR of 0.16%. Cost-effectiveness is achieved with lower ARR in the setting of lower imaging costs ($15, ARR 0.02%), and higher ARR with higher imaging costs ($225, ARR 0.29%). ARR for cost-effectiveness is independent of baseline revision rate, but varies with the cost of revision procedures.

CONCLUSION

At current revision rates for component malpositioning, only 1 revision among 400 THAs needs to be prevented for the utilization of fluoroscopy (or 1 in 385 THAs with flat plate imaging), to achieve cost-effectiveness.

Causes of Early Hip Revision Vary by Age and Gender: Analysis of Data From a Statewide Quality Registry

BACKGROUND

While total hip arthroplasty (THA) is extremely successful, early failures do occur. The purpose of this study was to determine the cause of revision in specific patient demographic groups at 3 time points to potentially help decrease the revision risk.

METHODS

Data for cases performed between 2012 and 2018 from a statewide, quality improvement arthroplasty registry were used. The database included 79,205 THA cases and 1,433 revisions with identified etiology (1,584 in total). All revisions performed at <5 years from the primary THA were reviewed. Six groups, men/women, <65, 65-75, and >75 years, were compared at revision time points <6 months, <1 year, and <5 years.

RESULTS

There were obvious and significant differences between subgroups based on demographics and time points (P < .0001). Seven hundred and fifty-six (53%) of all revisions occurred within 6 months. The most common etiologies within 6 months (756 revisions) were fracture (316, 41.8%), dislocation/instability (194, 25.7%), and infection (98, 12.9%). At this early time point, the most common revision cause was fracture for all age/gender-stratified groups, ranging from 27.6% in young men to 60% in older women. Joint instability became the leading cause for revision after 1 year in all groups.

CONCLUSION

This quality improvement project demonstrated clinically meaningful differences in the reason for THA revision between gender, age, and time from surgery. Strategies based on these data should be employed by surgeons to minimize the factors that lead to revision.

Anterior-Based Approaches to Total Hip Arthroplasty: Beyond the Learning Curve

BACKGROUND

Anterior-based approaches for total hip arthroplasty (THA) have gained popularity over the last decade. At our institution, anterior-based approaches are preferentially utilized, including both anterior-based muscle-sparing (ABMS) and direct anterior (DA) for primary THA. As there are higher complication rates during the transition to an anterior approach, we compared the outcomes and complications between ABMS and DA approaches beyond the learning curve.

METHODS

A retrospective study of all ABMS and DA primary THA patients performed at a single institution was performed, excluding the first 100 anterior cases done by any surgeon. In total, 813 DA and 378 ABMS THA cases were included. Demographics, complications, and patient-reported outcomes (PROMIS and HOOS) were obtained for each patient.

RESULTS

There was a 4.5% overall complication rate (4.1% in DA and 5.6% in ABMS, P = .248), with the most common complication being infection at 1.7% (1.5% vs 2.1%, P = .423). A revision was performed in 3.4% of cases overall (1.8% aseptic, 1.6% septic). There was no difference in complication rates between approaches. Length of surgery was shorter for ABMS (94.5 vs 116.0 minutes, P < .001). Both DA and ABMS had significant improvements in PROMIS and HOOS Jr. scores, without any significant difference between the groups.

CONCLUSIONS

Anterior-based approaches for primary THA demonstrated excellent clinical results and low complication rates overall. Beyond the learning curve, excellent results can be obtained with either ABMS or DA approach for primary THA.

Acetabular defect management and revision arthroplasty via the direct anterior approach

OBJECTIVE

Acetabular revision arthroplasty and osseous defect management through the direct anterior approach (DAA) with or without proximal extension.

INDICATIONS

Aseptic or septic component loosening, periacetabular osseous defects, pelvic discontinuity, intrapelvic cup protrusion, anterior pseudotumors, iliopsoas tendonitis, polyethylene wear or iliopsoas abscess.

CONTRAINDICATIONS

Clinically relevant gluteal tendon lesions, active infection, morbid obesity, large abdominal pannus, ASA (American Society of Anesthesiologists) score > III, inguinal skin infection.

SURGICAL TECHNIQUE

Electrocautery dissection is recommended to dissect the Hueter interval and to debulk pericapsular scar tissue. At all times during capsular debulking, it should be made sure not to damage the iliopsoas tendon or the neurovascular bundle. A stepwise releasing sequence can facilitate dislocation of the prosthesis. Most cases can be revised via the standard DAA but certain circumstances require an intra- or extrapelvic extension. Access to the anterior gluteal surface of the ilium can be provided using a "tensor snip". More posterior access is provided by the extensile extrapelvic approach described by Smith-Petersen. The intrapelvic Levine extension offers access to the entire visceral surface of the ilium and large parts of the anterior column.

POSTOPERATIVE MANAGEMENT

Patient revised via the intra- or extrapelvic extension and patients suffering from extensive soft tissue or osseous defects should undergo postoperative weight-bearing restrictions with 20 kg for 6 weeks.

RESULTS

Based on our studies, there is no limitation on the type of acetabular implant that can be used in DAA revision arthroplasty. Moreover, virtually all types of periacetabular osseous defects can be managed through the approach and its extensions. Acetabular revision arthroplasty via the DAA and its extensions is safe and can result in good midterm results.

A conservative approach to dislocation following total hip arthroplasty: a review of 8606 hips

PATIENTS AND METHODS

We present the data on 8606 total hip arthroplasty (THA) procedures carried out in 7818 patients through a posterior approach between 1998 and 2017.

RESULTS

218 hips (2.5%) suffered at least 1 dislocation with dislocation rates declining from 6.2% from 1998 to 2002 to 1.5% from 2003 to 2017. Overall, 92 hips (1.06%) required revision surgery but of these, only 5 (0.06%) had a full revision of both components with the remaining 87 requiring intervention only on the acetabular side. None have had a pseudo-arthrosis; none were left dislocated and all remain stable to date.

CONCLUSIONS

In patients who have a second dislocation within 3 months of their primary surgery we recommend a spica or long leg cylinder cast to reduce the need for revision surgery. We propose an algorithm to manage instability with less aggressive operative treatment in this often-elderly patient population with the potential for less physiological insult and significant cost savings.

Anterolateral minimally invasive hip approach offered faster rehabilitation with lower complication rates compared to the minimally invasive posterior hip approach-a University clinic case control study of 120 cases

INTRODUCTION

The surgical approach used in total hip arthroplasty (THA) has been identified as a factor affecting the outcome. In our University Hospital, the posterior surgical approach is the gold standard. The Rottinger approach is an anterolateral approach which is truly minimally invasive, as it does not vertically cut any muscle fibers. The objective of this study was to determine the difference in surgical outcomes between the posterior hip approach and the Rottinger approach which was newly adopted at our Hospital.

METHODS

In a retrospective study, a total of 120 patients underwent THA; 60 patients using the Rottinger approach by the young consultant surgeon and another 60 patients using the standard posterior approach by the senior orthopaedic surgeon. Patients have been controlled for age, gender, and ASA grades. All preoperative demographic data showed no significant difference between the control and study groups. The following parameters were analyzed: incision length, duration of the surgery, intraoperative blood loss, WOMAC index, Harris Hip Score, range of motion at 3 and 12 months after surgery, time of quitting the crutches, and willingness for the contralateral hip arthroplasty.

RESULTS

WOMAC index, surgical time, and incision lengths have been without significant difference in both approaches. Intraoperative blood loss was significantly lower in the Rottinger group (CI:  - 10.903,  - 0.064). Harris Hip score was significantly higher (CI: 4.564, 12.973) in the Rottinger group at 3 months, but similar (CI:  - 3.484, 2.134) at 12 months follow-up. At 3 months, active flexion and extension were significantly higher in the Rottinger group (CI: 0.595, 8.239; 2.487, 4.480, respectively), and active abduction and passive adduction (CI:  - 5.662,  - 0.338;  - 6.290,  - 1.410, respectively) in the posterior approach group. Patients in the Rottinger approach group on average quit crutches 3 weeks earlier and had no postoperative dislocations compared to 2 dislocations in the control group.

CONCLUSION

The Rottinger approach offered faster rehabilitation with less need for crutches and with lower complication rates.

Direct Anterior Approach for Primary Total Hip Arthroplasty Lowers the Risk of Dislocation Compared to the Posterior Approach: A Single Institution Experience

BACKGROUND

One purported benefit of the direct anterior approach (DAA) for total hip arthroplasty (THA) is a lower rate of postoperative dislocation.

METHODS

An institutional database was used to identify 8840 primary THAs performed from 2003 to 2020 including 5065 (57%) performed using the DAA and 3775 (43%) performed via the posterior approach (PA). Direction and mechanism of dislocation were determined from chart review. Outcomes were compared using Kaplan-Meier survivorship with dislocation as the endpoint and a Cox multivariate regression was used to investigate factors associated with dislocation. The mean follow-up was 1.7 ± 2.0 years for the DAA and 3.1 ± 3.3 years for the PA.

RESULTS

The 0.5% (26/5065) incidence of dislocation among DAA hips was significantly less than the 3.3% (126/3775) among PA cases (P < .001). The majority of dislocations were posterior (DAA 57%, PA 79%) and occurred during activities of daily living (DAA 82%, PA 77%). Five-year survivorship was significantly higher for the DAA group compared to the PA group (99.1% vs 95.4%, P < .001). Dislocation risk was 4.9 times higher for the PA compared to the DAA (hazard ratio = 4.9, 95% confidence interval = 3.2-7.5, P < .001). Increasing head diameter reduced the risk (hazard ratio = 0.70, 95% confidence interval = 0.57-0.86, P < .001). The 0.2% incidence (10/5065) of revision for instability among the DAA group was significantly lower than the 1.1% (43/3775) rate for the PA group (P < .001).

CONCLUSION

Compared to primary THAs performed with the PA, DAA cases had a lower risk of dislocation, higher survivorship with dislocation as an endpoint, and a lower risk of revision for instability in this single institution cohort.

Early failure of an uncemented femoral stem, as compared to two other stems with similar design, following primary total hip arthroplasty performed with direct anterior approach

INTRODUCTION

An increased risk of early femoral component loosening has been reported using the direct anterior approach (DAA) compared with other common surgical approaches. However, long-term data are scarce. The purpose of this study is: (1) to determine the incidence of early femoral loosening in a high volume, single surgeon's practice utilising the DAA approach; and (2) to examine the effect of stem design and type of coating on aseptic loosening in the early and mid-term postoperative period.

METHODS

A retrospective review of 1650 consecutive patients (1800 hips) who underwent total hip arthroplasty (THA) using the DAA between August 2011 and December 2017 was conducted at our institution. 3 types of uncemented femoral stems (Quadra-S, Avenir, TwinSys), with similar design, but different coating, were implanted. Patients were evaluated clinically and radiologically at 4 weeks, 3 months, 1 year, and annually thereafter.

RESULTS

After a mean follow-up of 46.4 months, the total incidence of revision for aseptic loosening was 0.44% (n = 8). All loose stems were Quadra-S, failing to achieve osseointegration, for an overall incidence of 0.96% (p = 0.002). None of the other stems were loose. Radiolucent lines around the proximal stem portion were visible in 75 Quadra-S stems (4.1%) on radiographs taken at 1 year postoperatively and continued to deteriorate at the latest follow-up.

CONCLUSIONS

In this specific cohort of patients, the increased rate of femoral stem aseptic loosening was implant-related and was attributed only to a specific type of femoral stem (Quadra-S). No relation to other factors was proven suggesting that the surface characteristics of this femoral stem and the lack of bioactive coating are responsible for the observed early femoral failures. These findings should be confirmed by additional registry work and larger population sample sizes are needed to evaluate the prosthesis performance after implantation through the DAA.

Revision Risk in a Cohort of US Patients Younger Than 55 Undergoing Primary Elective Total Hip Arthroplasty

BACKGROUND

As indications for elective total hip arthroplasty (THA) expand to younger patients, we sought to (1) compare revision risk following primary elective THA in patients <55 years at the time of their THA to patients aged ≥65 years and (2) identify specific risk factors for revision in patients <55 years.

METHODS

A Kaiser Permanente's total joint replacement registry was used to conduct a cohort study including primary elective THA patients aged ≥18 (2001-2018). In total, 11,671 patients <55 years and 53,106 patients ≥65 years were included. Multiple Cox regression was used to evaluate cause-specific revision risk, including septic revision, aseptic loosening, instability, and periprosthetic fracture. Stepwise Cox regression was used to identify patient and surgical factors associated with cause-specific revision in patients <55 years.

RESULTS

Patients <55 years had a higher risk of septic revision (hazard ratio [HR] = 1.30, 95% confidence interval [CI] = 1.02-1.66), aseptic loosening (HR = 2.60, 95% CI = 1.99-3.40), and instability (HR = 1.35, 95% CI = 1.09-1.68), but a lower risk of revision for periprosthetic fracture (HR = 0.36, 95% CI = 0.22-0.59) compared to patients aged ≥65 years. In the <55 age group, risk factors for septic revision included higher body mass index, drug abuse, and liver disease. Hypertension, anterior approach, and ceramic-on-ceramic were associated with aseptic loosening. White race, American Society of Anesthesiologists classification ≥3, smoker, paralysis, posterior approach, ceramic-on-ceramic, and smaller head diameter were associated with instability.

CONCLUSION

Identified risk factors varied depending on the cause for revision. Although septic revisions were related to patient characteristics, more modifiable factors, such as implant or surgical approach, were associated with revision due to aseptic loosening and instability.

LEVEL OF EVIDENCE

III.

The Effect of Surgical Approach and Femoral Prosthesis Type on Revision Rates Following Total Hip Arthroplasty: An Analysis of the Most Commonly Utilized Cementless Stems

BACKGROUND

Compared with other total hip arthroplasty (THA) approaches, the anterior approach has an increased rate of revision for femoral-sided complications, and certain stems may increase this risk. The present study aimed to assess the outcome of THA by surgical approach, according to the femoral stem utilized in the procedure.

METHODS

Data from the Australian Orthopaedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis via the anterior or posterior approach with use of 1 of 5 of the most common cementless femoral stems from January 2015 to December 2019. The primary outcome measures were the cumulative percent revision (CPR) for all causes and for femoral stem loosening and fracture. The CPR was compared between THAs performed via the anterior and posterior approaches for all stems and for each individual femoral stem, as well as between individual femoral stems for each approach.

RESULTS

The study included 48,716 THAs performed with use of cementless stems, of which 22,840 utilized an anterior approach and 25,876 utilized a posterior approach. There was no difference in the all-cause CPR between the anterior and the posterior approach, but the anterior approach had a higher CPR for loosening (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.48 to 2.69; p < 0.001) and fracture (HR, 1.78; 95% CI, 1.34 to 2.35; p < 0.001). There was apparent variation in the CPR across the different cementless stems when an anterior approach was utilized. The Quadra-H (Medacta) had a higher all-cause CPR when compared with the Polarstem (Smith & Nephew; HR, 1.49; 95% CI, 1.16 to 1.91; p = 0.002) and Corail (DePuy Synthes; HR, 1.31; 95% CI, 1.00 to 1.70; p = 0.0478). Variation was less apparent with the posterior approach.

CONCLUSIONS

THAs performed via the anterior approach had higher rates of revision for femoral stem loosening and fracture, with greater variation in outcomes between individual stems.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Radiographic assessment of the dynasty biofoam acetabular component with a minimum 2 years follow-up

INTRODUCTION

Acetabular components utilising novel ultraporous metal matrices have been recently introduced into clinical practice with improved interference fit, decreased stress shielding, and hope for more reliable osseointegration. 1 such example is the Dynasty Biofoam cup, which has been in clinical use for over a decade but has few reports documenting its clinical and radiographic performance.

METHODS

A single-centre retrospective study was performed evaluating 96 Dynasty Biofoam acetabular components implanted between March 2010 and August 2014 with minimum 2-year radiographic follow-up. Patients that received components for revision surgery or that had early complications postoperatively (femur fracture, prosthetic infection) were excluded. Biofoam patients were compared to 96 patients that received the Trident PSL acetabular component and were matched for age, gender, and BMI. Patient reported outcomes, component position and radiographic features of cup loosening, including radiolucent lines and sclerosis were compared among groups.

RESULTS

Patient-reported outcomes at 2 years were similar among groups. Cup anteversion was similar but inclination was significantly greater in the Biofoam group (p = 0.006). A significantly greater number of Biofoam components exhibited 2-zone (27.2%) and 3-zone (12.0%) radiolucencies compared to 0% of the Trident shells (p < 0.05). 2 Biofoam cups were revised for aseptic loosening compared to no Trident cups (p = 0.49).

DISCUSSION

Despite adequate implant survivorship, over a quarter of Biofoam cups had 2 or more radiolucent zones in early follow-up. Longer follow-up is needed to determine if the aseptic revision rate for this cup will increase.

Reduction of Periprosthetic Proximal Femur Fracture in Direct Anterior Total Hip According to Stem Design

The direct anterior approach (DAA) is gaining popularity in primary total hip arthroplasty (THA). Although DAA has demonstrated many advantages over other surgical approaches, periprosthetic femur fractures (PPFF) rates continue to be higher. Femoral stem designs that allow for easier insertion via a DAA may contribute to the higher rates of fracture seen in this approach. Certain stem designs and fixation methods may reduce the risk of PPFF via a DAA in primary THA.

Is Surgical Approach for Primary Total Hip Arthroplasty Associated With Timing, Incidence, and Characteristics of Periprosthetic Femur Fractures?

BACKGROUND

Periprosthetic femur fractures (PFF) involving primary total hip arthroplasty (THA) remain a significant concern. The purpose of this study was to evaluate the effect of surgical approach during primary THA on early PFF with respect to fracture timing, incidence, radiographic parameters, and surgery-related factors.

METHODS

A retrospective review of all patients with PFF during or after primary THA from 2011 to 2019 was conducted at a single, urban academic institution. Of the study cohort of 11,915 patients, 79 patients with PFF were identified (0.66%). Direct anterior (DA), posterior anterior (PA), and laterally based (LA) cohorts were formed based on the surgical approach. PA and LA groups were combined to form a nonanterior (NA) cohort. Radiographic parameters, surgical factors, and fracture mechanism were analyzed.

RESULTS

The incidence of fracture across approaches was 0.70% (33/4707; DA), 0.63% (35/5600; PA), and 0.68% (11/1608; LA) (P = .97). Time from THA to fracture was significantly shorter in the DA cohort (12.5 ± 14.1 days) than the NA cohort (48.2 ± 120.6 days) (P = .05). Postoperatively identified, atraumatic PFFs were more common in the DA cohort (78.3%, 18/23) than the NA cohort (51.6%, 16/31) (P = .045). There were no differences between groups in radiographic or other clinical parameters.

CONCLUSION

Patients who underwent DA THA have significantly shorter time to PFF and were more often identified postoperatively with an atraumatic mechanism than patients who underwent NA approaches. The known difficulty in femoral exposure and stem placement with the DA approach may play a role in contributing to a higher rate of intraoperative or early postoperative PFF.

Does the Surgical Approach Influence the Canal Fill of the Proximal Femur for Hip Arthroplasty?

Background

Choosing the right size of the stem is crucial for uncemented hip arthroplasty. Undersizing can lead to early loosening, peri-prosthetic fracture due to femoral implant insertion, and/or osteointegration failure. The main objective of this study was to find a correlation between the surgical approach and the intramedullary prosthetic canal fill ratio (CFR) of the uncemented femoral implant. The hypothesis of this work was that the surgical approach does not influence the stem sizing during hip arthroplasty.

Methods

In this consecutive series, we analyzed the radiological images of 183 patients who underwent primary hip arthroplasty with 4 different surgical approaches. Dimensions of the implant were evaluated by radiographic measurement of the CFR. In order to assess the shape of the femur, we measured the canal flare index on the preoperative radiographs, and the canal calcar ratio was also measured to establish the shape of the femur according to Dorr's classification.

Results

No significant difference was found between the surgical approach and the CFR measured at 4 different levels (CFR 1, 2, 3, and 4) on the postoperative radiograph. When the shape of the femur was assessed by canal flare index, there was no significant difference in implant, whether the femur had a stovepipe canal shape or a champagne-fluted canal shape.

Conclusion

This study showed that the surgical approach in hip arthroplasty does not influence the canal fill. Therefore, the surgical approach does not factor in undersizing the femoral implant. Despite some difficulties in the exposure of the medullary shaft described by some authors, the anterior approach is not a risk factor for undersizing an anatomical femoral stem.

Level of evidence

4

Short stem hip arthroplasty via the minimally invasive direct anterior approach

OBJECTIVE

Tissue-sparing, minimally invasive hip arthroplasty via the direct anterior approach (DAA) using a partially neck-preserving, calcar-guided short stem.

INDICATIONS

Primary and secondary osteoarthritis of the hip due to developmental dysplasia, femoroacetabular impingement, femoral head necrosis or trauma sequelae.

CONTRAINDICATIONS

Severe osteoporosis, active infection, American Society of Anesthesiologists (ASA) > III, large metaphyseal bone defects, severe metaphyseal deformities, Dorr type C femur.

SURGICAL TECHNIQUE

Supine position on a standard operating table without extension device. Classic DAA skin incision or bikini incision distal to the inguinal fold. Blunt dissection entering the Hueter interval. Capsulotomy with capsule preservation or partial capsulectomy. Intraoperatively, it is crucial to adhere to the preoperatively planned angle and height of the femoral neck osteotomy. During femoral head removal and acetabular preparation, care must be taken to avoid iatrogenic damage to the remaining neck. After cup positioning, femoral access is achieved by release of superior capsular structures. During opening of the medullary canal and broaching, femoral torsion and axis have to be taken into account for correct rotational and axial alignment. Femoral broaches are inserted in an ascending series of sizes until the last broach is firmly lodged and is in direct contact with the antero-medial femoral neck cortex. Fluoroscopic control in two planes to check for femoral anatomic and overall offset and assess whether the implant is adequately seated with cortical support at the calcar, the distal lateral and the dorsal cortex. Implantation of the definitive implants, local infiltration analgesia and wound closure.

RESULTS

Between 1/2011 and 12/2016 60 patients (24 female, 36 male; mean age 44 years) were treated with a partially neck-preserving short stem via the described approach. Seven patients underwent a bi-lateral procedure. Thus, 67 procedures were analysed in this retrospective cohort study. Mean follow-up was 70 months (range 28-93). The median Harris Hip Score was 48 (range 11-88) preoperatively and 98 (range 80-100) postoperatively.

CONCLUSION

The minimally invasive implantation of a partially neck-preserving stem via DAA provides a safe technique with good to excellent clinical results in the mid-term.

Intraoperative Complications and Early Return to the Operating Room in Total Hip Arthroplasty Performed Through the Direct Anterior and Posterior Approaches. An Institutional Experience of Surgeons After Their Learning Curve

BACKGROUND

Proponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA).

METHODS

A total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year.

RESULTS

Intraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02).

CONCLUSION

This comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.

Primary total hip arthroplasty via the direct anterior approach in the lateral decubitus position : surgical technique, learning curve, complications, and early results

AIMS

The direct anterior approach (DAA) for total hip arthroplasty (THA) has potential advantages over other approaches and is most commonly performed with the patient in the supine position. We describe a technique for DAA THA with the patient in the lateral decubitus position and report the early clinical and radiological outcomes, the characteristics of the learning curve, and perioperative complications.

METHODS

All primary DAA THAs performed in the lateral position by a single surgeon over a four-year period from the surgeon's first case using the technique were identified from a prospectively collected database. Modified Harris Hip Scores (mHHS) were collected to assess clinical outcome, and routine radiological analysis was performed. Retrospective review of the medical records identified perioperative complications, the characteristics of the learning curve, and revisions.

RESULTS

A total of 257 patients were included in the study. Their mean age was 60 years (SD 9.0). A total of 164 (64%) were female. The mean mHHS improved significantly from 52.1 (SD 16.2) preoperatively to 94.4 (SD 11) at a follow-up of one year (p < 0.001), with 212 of 225 patients (94%) achieving a minimal clinically important difference (MCID) (> 8 points). Radiological evaluation showed a mean leg length discrepancy of 2.6 mm (SD 5.9) and a mean difference in femoral offset of 0.2 mm (SD 4.9). A total of 234/243 acetabular components (96.3%) were positioned within Lewinnek's safe zone. Analysis of operating time, blood loss, the position of the components, and complications did not identify a learning curve. A total of 14 patients (5.4%) had a major perioperative complication and three (1.2%) required revision THA. There were no major neurovascular complications and no dislocations.

CONCLUSION

We have described and analyzed a surgical technique for undertaking DAA THA in the familiar lateral decubitus position using a routine operating table, positioning devices, and instrumentation, and shown that it can be performed safely and effectively under these circumstances. Cite this article: Bone Joint J 2021;103-B(7 Supple B):53-58.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

Background

There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m² and age of 72 years, and 60% of whom were female.

Results

We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m², tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001).

Conclusions

Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient.

Level of Evidence

IV.

Instability After Total Hip Arthroplasty and the Role of Advanced and Robotic Technology

Instability remains the leading cause of reoperation following total hip arthroplasty (THA). In this article, the risk factors for instability after THA are reviewed, including patient-related characteristics, surgical techniques, positioning of implants, and the role of advanced technology and robotics as a platform that may reduce the incidence of instability.

Managing Hip-Spine Concepts in the Direct Anterior Approach With Use of Fluoroscopy

BACKGROUND

The spinopelvic relationship in regard to total hip arthroplasty has become a topic of increasing interest in recent years. Hip arthritis and a stiff lumbar spine create a situation where the spinopelvic junction has decreased mobility, which in turn increases the risk of instability after total hip arthroplasty as the femoral acetabular joint must undergo increased motion. Regardless of the approach, surgeons should be aware of the risk of instability in patients with a stiff spinopelvic junction and the necessary modifications to component positioning to avoid postoperative instability. As many direct anterior approach surgeons use fluoroscopy for intraoperative navigation, anterior approach surgeons must also understand how to best use this technology to improve component positioning.

METHODS

In this article, we address the basic concepts surrounding spinopelvic stiffness, the intraoperative component adjustments necessary for optimizing stability, and how to appropriately use fluoroscopy for navigation in the direct anterior approach.

CONCLUSIONS

Appropriate use of intraoperative fluoroscopy includes understanding the impact of parallax and distortion, properly recreating the patient's standing functional pelvic plane intraoperatively and adjusting the cup's target position based on a preoperative understanding of the patient's spinopelvic motion.

Bilateral Total Hip Arthroplasty in the Setting of Developmental Dysplasia of the Hip and Extreme Hip Flexion Requirements due to Phocomelia

Phocomelia is a rare congenital birth defect marked by hypoplastic or markedly absent limbs. Developmental dysplasia of the hip (DDH) is a congenital disorder with a failure of the native acetabulum to provide complete coverage over the femoral head. The secondary osteoarthritis that develops from DDH is technically challenging for orthopedic surgeons because of distorted anatomy. The present case describes the diagnosis of Crowe 3 DDH in a phocomelia patient with hyperflexion requirements who successfully underwent staged bilateral total hip arthroplasty via a direct anterior approach. It highlights the utility of preoperative computerized tomography and intraoperative computer navigation to assist in implant placement. Recognizing difficult arthroplasty cases in advance is imperative as these cases may require great expertise and more extensive surgical planning.

Short stem total hip arthroplasty with the direct anterior approach demonstrates suboptimal fixation

PURPOSE

Short stems use has increased substantially despite variable results reported in the literature. The purpose of this study was to report the rate of complications using a short stem implanted through the direct anterior approach (DAA), and to evaluate mid-term clinical and radiological results focusing on femoral stem fixation.

METHODS

Between April 2009 and November 2014, 698 elective total hip arthroplasties (THAs) were performed using a fully hydroxyapatite-coated short stem (AMIStem-H®). The mean age was 65.7 years (SD 12.6). Patients were invited for clinical and radiological evaluation, and to complete patient-reported outcomes questionnaires at two and five years after surgery. The mean follow-up was 6.2 years (range 2-9.73 years).

RESULTS

During the study period, 59 (8.5%) patients died and 24 (3.4%) were lost to follow-up. There were six (0.9%) dislocations and 12 (1.7%) fractures, seven occurred intra-operatively. Twenty-nine (4.2%) THAs required revision surgery. Eleven THAs were revised for aseptic loosening of the stem at a mean 4.9 years (1.2-7.3 years). Five years after surgery, radiographs of 324 THAs (324/425 eligible = 76.2%) were available. Stem subsidence ≥ 2 mm was present in 42 cases (12.9%), proximal radiolucencies in 101 hips (31.5%), cortical thickening in 52 (16.0%), and a pedestal in 219 (67.6%). An Engh score between - 10 and 0 was associated with lower HHS pain subscore (p = 0.005), a higher risk of stem revision for aseptic loosening (18.8% vs. 2.7%; p = 0.008), and was more frequent in younger patients with ASA score 1.

CONCLUSION

Patients presenting radiological alterations at five years had an increased risk of revision for aseptic stem loosening and also inferior clinical results. Our study warrants further continued scrutiny of mid- and long-term survivorship of the AMIStem-H®, with radiological results at five years indicating suboptimal fixation of the stem in younger and active patients.