Dislocation after total hip arthroplasty: a randomized clinical trial of a posterior approach and a modified lateral approach

Posterior Approach and Inferior Capsulotomy in Bipolar Hemiarthroplasty for Femoral Neck Fractures: Comparison with Superior Capsulotomy

Background

Hemiarthroplasty is frequently used to treat displaced femoral neck fractures in elderly patients, but it has a higher risk of postoperative dislocation. We introduced the posterior approach and inferior capsulotomy (PAICO) to enhance joint stability after bipolar hemiarthroplasty for femoral neck fracture. We evaluated whether the PAICO would have a lower dislocation rate than the conventional posterior approach with superior capsulotomy.

Methods

From January 2021 to December 2021, we prospectively recruited 25 patients (25 hips) aged 50 years or older who underwent bipolar hemiarthroplasty for femoral neck fractures due to low-energy trauma as the PAICO group. We compared the PAICO group with a historical control group who had undergone hemiarthroplasty in 7 institutes between 2010 and 2020. The primary endpoint was dislocation within 1 year after the surgery. We compared data from the PAICO group with the data from the historical control group from the Korean Hip Fracture Registry which was carried out in South Korea.

Results

A total of 25 patients (25 hips) were enrolled in the present study; 3,477 patients (3,571 hips) who underwent bipolar hemiarthroplasty were reviewed as the historical control group. In the PAICO group, we observed no dislocation, whereas the dislocation rate in the control group was 1.3%.

Conclusions

In patients with displaced femoral neck fractures, the PAICO approach demonstrated comparable results in operation time and complication rates when compared to bipolar hemiarthroplasty using superior capsulotomy. Notably, there were no observed cases of dislocation among patients who underwent the PAICO approach. We recommend this PAICO approach to surgeons using the posterior approach, hoping to prevent dislocation in bipolar hemiarthroplasty.

Optimization of Acetabular Cup Abduction by Adjusting Pelvic Pitch

Background

The purposes of this study were to determine the accuracy of our cup positioning method and to evaluate the dislocation rate after total hip arthroplasty (THA).

Methods

After positioning the patient in the lateral decubitus position on the operation table, an anteroposterior view of the hip was taken. The pelvic pitch was measured on the X-ray. A positive pitch was defined as the caudal rotation of the upper hemipelvis. Our target abduction of the cup was 43°. We used the cup holder to guesstimate the cup abduction. In a preliminary study, we found that the weight of the cup holder increased the pelvic pitch by 5°. Thus, the target abduction of the cup holder was calculated by a formula: 43° - pelvic pitch - 5°. During the cup insertion, the cup holder was anteverted to the calculated target according to the concept of combined anteversion. We evaluated 478 THAs (429 patients), which were done with the use of the method.

Results

The mean cup abduction was 43.9° (range, 32.0°-53.0°) and the mean error of cup abduction was 2.4° (standard deviation [SD], 2.0°; range, 0.0°-11.0°). The mean cup anteversion was 28.5° (range, 10.0°-42.0°) and the mean error of cup anteversion was 6.7° (SD, 5.2°; range, 0.0°-27.6°). Of all, 82.4% of the cups (394 / 478) were within the safe zone: 30°-50° abduction and 10°-35° anteversion. During 2- to 5-year follow-up, no hip dislocated.

Conclusions

Our adjusting method according to the pelvic pitch can be a reliable option for optimizing the cup abduction in THA.

Which approach of total hip arthroplasty is the best efficacy and least complication?

BACKGROUND

Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function. Approaches of the hip have been exhaustively explored about pros and cons. The efficacy and the complications of hip approaches remains inconclusive. This study conducted an umbrella review to systematically appraise previous meta-analysis (MAs) including conventional posterior approach (PA), and minimally invasive surgeries as the lateral approach (LA), direct anterior approach (DAA), 2-incisions method, mini-lateral approach and the newest technique direct superior approach (DSA) or supercapsular percutaneously-assisted total hip (SuperPath).

AIM

To compare the efficacy and complications of hip approaches that have been published in all MAs and randomized controlled trials (RCTs).

METHODS

MAs were identified from MEDLINE and Scopus from inception until 2023. RCTs were then updated from the latest MA to September 2023. This study included studies which compared hip approaches and reported at least one outcome such as Harris Hip Score (HHS), dislocation, intra-operative fracture, wound complication, nerve injury, operative time, operative blood loss, length of hospital stay, incision length and VAS pain. Data were independently selected, extracted and assessed by two reviewers. Network MA and cluster rank and surface under the cumulative ranking curve (SUCRA) were estimated for treatment efficacy and safety.

RESULTS

Finally, twenty-eight MAs (40 RCTs), and 13 RCTs were retrieved. In total 47 RCTs were included for reanalysis. The results of corrected covered area showed high degree (13.80%). Among 47 RCTs, most of the studies were low risk of bias in part of random process and outcome reporting, while other domains were medium to high risk of bias. DAA significantly provided higher HHS at three months than PA [pooled unstandardized mean difference (USMD): 3.49, 95% confidence interval (CI): 0.98, 6.00 with SUCRA: 85.9], followed by DSA/SuperPath (USMD: 1.57, 95%CI: -1.55, 4.69 with SUCRA: 57.6). All approaches had indifferent dislocation and intraoperative fracture rates. SUCRA comparing early functional outcome and composite complications (dislocation, intra-operative fracture, wound complication, and nerve injury) found DAA was the best approach followed by DSA/SuperPath.

CONCLUSION

DSA/SuperPath had better earlier functional outcome than PA, but still could not overcome the result of DAA. This technique might be the other preferred option with acceptable complications.

The influence of direct anterior approach and postero-lateral approach on wound complications after total hip arthroplasty: A meta-analysis

To date, we have reviewed the synthesis literature critically through four databases: PubMed, Embase, Cochrane Library and Web of Science. Eight relevant studies were examined after compliance with the criteria for inclusion and exclusion, as well as documentation quality evaluation. This report covered all randomised, controlled studies of total hip arthroplasty (THA) comparing the direct anterior approach (DAA) with the postero-lateral approach (PLA). The main result was surgical site infection rate. The secondary results were duration of the operation, length of the incision and VAS score after surgery. The results of the meta-analyses of wound infections in the present trial did not show any statistically significant difference in DAA versus PLA (between DAA and PLA) (OR = 1.42, 95%CI: 0.5 to 4.04, p = 0.51). Compared with PLA, DAA had shorter surgical incision (WMD = -3.2, 95%CI: -4.00 to -2.41; p < 0.001) and longer operative times(WMD = 14. 67, 95%CI: 9.24 to 20.09; p < 0.001). Postoperative VAS scores were markedly lower in DAA compared with PLA within 6 weeks of surgery (p < 0.05), with low heterogeneities(I2  = 0). We found that DAA did not differ significantly from PLA in terms of the risk of wound infection for THA and that the surgical incisions was shorter and less postoperative pain after surgery, even though DAA surgery takes longer.

The Modified Spare Piriformis and Internus, Repair Externus Approach for Hip Arthroplasty

We present the case of an 80-year-old Malaysian gentleman who sustained a displaced intracapsular neck of femur (NOF) fracture and underwent a modified SPAIRE (Sparing Piriformis and Internus, Repair Externus) approach for total hip replacement (THR). The standard approach used in our hospital for THR in NOF fractures is the modified Hardinge approach to the hip. We used this modified SPAIRE approach as this patient lives in a 'Mahjong' center and always sits cross-legged on the floor. Therefore, he is at increased risk of an anterior dislocation. This approach is a modification of the standard SPAIRE approach popularized by the Exeter Hip Unit, United Kingdom. In this report, we describe the modification of the SPAIRE approach that has not been described before and the outcome for this patient.

Evaluation of Comparative Efficacy and Safety of Surgical Approaches for Total Hip Arthroplasty: A Systematic Review and Network Meta-analysis

IMPORTANCE

Each approach for primary total hip arthroplasty (THA) has a long learning curve, so a surgeon's choice to change their preferred approach needs to be guided by clear justifications. However, current evidence does not suggest that any of the THA approaches are more beneficial than others, and the choice of approach is mainly based on the knowledge and experience of the surgeon and individual patient characteristics.

OBJECTIVE

To assess the efficacy and safety associated with different surgical approaches for THA.

DATA SOURCES

A comprehensive search of PubMed, EMBASE, and Cochrane databases from inception to March 26, 2022; reference lists of eligible trials; and related reviews.

STUDY SELECTION

Randomized clinical trials (RCTs) comparing different surgical approaches, including the 2-incision approach, direct anterior approach (DAA), direct lateral approach (DLA), minimally invasive direct lateral approach (MIS-DLA), minimally invasive anterolateral approach (MIS-ALA), posterior approach (PA), minimally invasive posterior approach (MIS-PA), and supercapsular percutaneously assisted total hip arthroplasty (SuperPath), for primary THA.

DATA EXTRACTION AND SYNTHESIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 2 reviewers independently extracted data on study participants, interventions, and outcomes as well as assessed the risk of bias using the Cochrane risk of bias tool and the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation framework. A frequentist framework was used to inform a series of random-effects network meta-analyses.

MAIN OUTCOMES AND MEASURES

The outcomes were hip score (range, 0-100, with higher scores indicating better overall hip condition), pain score (range, 0-100, with higher scores indicating more pain), hospitalization time, operation time, quality of life score, blood loss, cup abduction angle, and cup anteversion angle.

RESULTS

Of 2130 retrieved studies, 63 RCTs including 4859 participants (median [IQR] age, 64.0 [60.3-66.5] years; median [IQR] percentage male, 46.74% [38.64%-54.74%]) were eligible for analysis. Eight surgical approaches were evaluated. For hip score, DAA (mean difference [MD], 4.04; 95% CI, 1.92 to 6.16; moderate certainty), MIS-ALA (MD, 3.00; 95% CI, 0.43 to 5.59; moderate certainty), MIS-DLA (MD, 3.37; 95% CI, 1.05 to 5.68; moderate certainty), MIS-PA (MD, 4.46; 95% CI, 1.60 to 7.31; moderate certainty), PA (MD, 4.37; 95% CI, 1.87 to 6.88; high certainty), and SuperPath (MD, 5.00; 95% CI, 0.58 to 9.42; high certainty) were associated with greater improvement in hip score compared with DLA. DLA was associated with lower decrease in pain score than SuperPath (MD, 1.16; 95% CI, 0.13 to 2.20; high certainty) and MIS-DLA (MD, 0.90; 95% CI, 0.04 to 1.76; moderate certainty). PA was associated with shorter operation times compared with 2-incision (MD, -23.85 minutes; 95% CI, -36.60 to -11.10 minutes; high certainty), DAA (MD, -13.94 minutes; 95% CI, -18.79 to -9.08 minutes; moderate certainty), DLA (MD, -10.50 minutes; 95% CI, -16.07 to -4.94 minutes; high certainty), MIS-ALA (MD, -6.76 minutes; 95% CI, -12.86 to -0.65 minutes; moderate certainty), and SuperPath (MD, -13.91 minutes; 95% CI, -21.87 to -5.95 minutes; moderate certainty). The incidence of 6 types of complications did not differ significantly between the approaches.

CONCLUSIONS AND RELEVANCE

In this study, moderate to high certainty evidence indicated that compared with PA, all surgical approaches except DLA were associated with similar improvements of hip score but longer operation time. DLA was associated with smaller improvement of hip score. The safety of the different approaches did not show significant differences. These findings will help health professionals and patients with better clinical decision-making and also provide references for policy makers.

Combination effect of intraoperative and postoperative intravenous tranexamic acid in hip hemiarthroplasty. A propensity score matched analysis

BACKGROUND

Tranexamic acid (TXA) has been proven to reduce perioperative blood loss and the incidence of allogeneic blood transfusion in total joint arthroplasty (TJA). However, there is limited literature on the use of TXA in patients undergoing hip hemiarthroplasty. Furthermore, combination effect of intraoperative and postoperative intravenous TXA has not been investigated extensively. The purpose of this study was to evaluate this combination effect on hip hemiarthroplasty by a propensity score matched analysis (PSMA).

METHODS

This is a retrospective cohort study involving hip hemiarthroplasty for femoral neck fracture. All patients received 1g intraoperative intravenous TXA. One group also received 1g intravenous TXA 6h after surgery, while the other group did not. Perioperative blood loss, the incidence of allogeneic blood transfusion and venous thromboembolism (VTE) were collected and compared.

RESULTS

209 patients who underwent unilateral hip hemiarthroplasty were included. PSMA resulted in 66 matched pairs in each group. There were no significant differences in perioperative blood loss on postoperative day (POD) # 1, 3, 5 (637.2 ± 285.9 versus 653.6 ± 305.5, 726.6 ± 274.2 versus 676.3 ± 313.2, 795.5 ± 291.2 versus 759.9 ± 328.4), the incidence of allogeneic blood transfusion (9.1% versus 12.1%) and VTE (1.5% versus 1.5%) between the two groups (P value> 05) for up to one year.

CONCLUSION

Intraoperative and postoperative intravenous TXA have no combination effect on reducing perioperative blood loss, the incidence of allogeneic blood transfusion and VTE in patients undergoing hip hemiarthroplasty.

Factors influencing the outcomes of minimally invasive total hip arthroplasty: a systematic review

Introduction

The present systematic review investigated possible factors which may influence the surgical outcome of minimally invasive surgery for total hip arthroplasty (MIS THA).

Methods

In January 2022, the Embase, Google Scholar, PubMed, and Scopus databases were accessed. All the clinical trials investigating the clinical outcome of MIS THA were considered.

Results

Data from 9486 procedures were collected. Older age was moderately associated with greater Visual Analogue Scale (VAS) (P = 0.02) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (P = 0.009) at last follow-up, and shorter surgical duration (P = 0.01). Greater body mass index (BMI) at baseline was moderately associated with greater cup anteversion (P = 0.0009), Oxford Hip Score (OHS) at last follow-up (P = 0.04), longer surgical duration (P = 0.04), increased leg length discrepancy (P = 0.02), and greater rate of infection (P = 0.04). Greater VAS at baseline was weakly associated with greater VAS at last follow-up (P < 0.0001), total estimated blood lost (P = 0.01), and lower value of Harris Hip Score (HHS) (P = 0.0005). Greater OHS at baseline was associated with greater post-operative VAS (P = 0.01). Greater WOMAC at baseline was associated with lower cup anteversion (P = 0.009) and greater VAS (P = 0.02). Greater HHS at baseline was associated with shorter hospitalisation (P = 0.001).

Conclusion

Older age and greater BMI may represent negative prognostic factors for MIS THA. The clinical outcome is strongly influenced by the preoperative status of patients.

Third-Generation Ceramic-on-Ceramic Total Hip Arthroplasty in Patients with Osteonecrosis of the Femoral Head: A 10- to 16-year Follow-up Study

BACKGROUND

Long-term follow-up results of ceramic-on-ceramic (COC) total hip arthroplasty (THA), specifically, in patients with osteonecrosis of the femoral head (ONFH) are unknown. We evaluated (1) clinical results and radiological outcomes, (2) ceramic-related complications: noise and ceramic fracture, (3) osteolysis, and (4) survivorship after alumina COC THA in ONFH patients with longer than 10-year follow-up.

METHODS

From May 2003 to June 2009, 325 ONFH patients (403 hips) underwent primary THAs at our department. Among them, 231 patients (293 THAs) were followed for 10 to 16 (mean, 12.9) years. There were 148 men and 83 women, their mean age at the time of THA was 47.2 years, and their mean body index was 24.0 kg/m2. The postoperative CT scans were done in 160 hips.

RESULTS

Grinding sensation or squeak was noted in 6.8% (20/293), ceramic head fracture occurred in 2.4% (7/293) and acetabular osteolysis developed in 0.7% (2/293). All 7 ceramic fractures occurred in 28-mm short-neck heads. There was no detectable wear or prosthetic loosening, and the 16-year survivorship was 96.0% (95% confidence interval; 93.8% to 98.2%). The mean Harris hip score was 91.7 (range, 84 to 100) points at the final follow-up.

CONCLUSIONS

The 10- to 16-year results of alumina COC THAs were encouraging with an excellent survivorship. However, ceramic fracture and noise still remain matters of concern. We recommend not to use 28-mm short-neck ceramic head to avoid ceramic head fractures.

LEVEL OF EVIDENCE

III.

Cementless Hip Arthroplasty in Patients with Subchondral Insufficiency Fracture of the Femoral Head

BACKGROUND

Subchondral insufficiency fracture of the femoral head (SIFFH) occurs in elderly patients and might be confused with osteonecrosis of the femoral head (ONFH). Subchondral insufficiency fracture of the femoral head is an insufficiency fracture at the dome of the femoral head and has been known to be associated with osteoporosis, hip dysplasia, and posterior pelvic tilt. This study's aims were to evaluate (1) surgical complications, (2) radiological changes, (3) clinical results, and (4) survivorship of THA in patients with SIFFH.

METHODS

From November 2010 to June 2017, 21 patients (23 hips); 5 men (5 hips) and 16 women (18 hips) underwent cementless THA due to SIFFH at our institution. Their mean age was 71.9 years (range, 57 to 86) at the time of surgery, and mean T-score was -2.2 (range, -4.2 to 0.2). The mean lateral center-edge angle, abduction, and anteversion of the acetabulum were 29.9° (range, 14.8° to 47.5°), 38.5° (range, 31° to 45°), and 20.0° (range, 12° to 25°), respectively. The mean pelvic incidence, lumbar kyphotic angle and posterior pelvic tilt were 56.4° (range, 39° to 79°), 14.7° (range, -34° to 43°), and 13.0° (range, 3° to 34°), respectively.

RESULTS

An intraoperative calcar crack occurred in 1 hip. The mean anteversion and abduction of cup were 29.0° (range, 17° to 43°) and 43.3° (range, 37° to 50°), respectively. One patient sustained a traumatic posterior hip dislocation 2 weeks after the procedure, and was treated with open reduction. At a mean follow-up of 35.4 months (range, 24 to 79 months), no hip had prosthetic loosening or focal osteolysis. At the latest follow-up, the mean modified Harris hip score was 79.1 (range, 60 to 100) points, and mean UCLA activity score was 4.2 (range, 2 to 7) points. The survivorship was 95.7% (95% CI, 94.9% to 100%) at 6 years.

CONCLUSIONS

Cementless THA is a favorable treatment option for SIFFH in elderly patients.

LEVEL OF EVIDENCE

3.

High Risk of Neck-liner Impingement and Notching Observed with Thick Femoral Neck Implants in Ceramic-on-ceramic THA

BACKGROUND

Recently, impingement between the femoral stem and ceramic liner, which appears as a notch in the stem neck on radiographs, has emerged as a new complication. However, the proportion of impingement, potential risk factors, and related complications are poorly elucidated.

QUESTION/PURPOSES

In patients who underwent ceramic-on-ceramic (CoC) THA and had at least 10 years of follow-up, we asked: (1) What proportion had radiographic evidence of stem neck-ceramic liner impingement (notching of the stem), and what implant design, implantation factors, or complications such as ceramic fracture or metallosis are associated with impingement? (2) How common are the complications of noise and ceramic fracture? (3) What are the radiologic changes (including fixation of femoral and acetabular components, osteolysis, and heterotopic ossification) and clinical outcomes as determined by the modified Harris hip score (mHHS) for this cohort? (4) What is the survivorship with implant revision as the endpoint and with reoperation for any reason as the endpoint after CoC THA using a thick-neck stem design?

METHODS

Between May 2003 and April 2010, 643 patients underwent primary THA at a tertiary referral hospital. After excluding patients with metal-on-polyethylene and with ceramic-on-polyethylene implants, 621 patients were considered eligible for this study. All patients received the same hemispherical titanium cup, a standard-length tapered titanium stem, and a CoC bearing. Of those, 19% (115) were lost to follow-up before 10 years, and 8% (50) were excluded because they died before the minimum follow-up duration of 10 years, leaving 73% (456) for analysis. Patients had a mean age of 50 ± 14 years and were followed for a median (range) of 13 years (10 to 17). The mean cup abduction was 38° ± 5°, and the mean cup anteversion was 26° ± 7°. To determine the proportion of patients with the neck-liner impingement, we analyzed the plain radiographs of every patient during follow-up to detect notches around the stem. The detection of stem neck notches on the radiographs was reliable (intraobserver reliability: κ = 0.963; p < 0.001 and interobserver reliability: κ = 0.975; p < 0.001). To evaluate factors related to notching, we compared the possible confounding factors including gender, age, BMI, implant position, neck length, and head diameter. Complications such as ceramic fracture, noise, dislocation, and periprosthetic joint infection were recorded. Noise was evaluated via interview and with the Hip Noise Assessment Questionnaire, which assessed the noise qualitatively. For clinical outcome, we assessed the mHHS, which includes pain and function scales (0 [worst] to 100 [best]), every visit. Tilting of at least 4° or migration of at least 4 mm was the criteria for cup loosening; subsidence more than 3 mm, any change in position, or a continuous radiolucent line greater than 2 mm was the criteria for stem loosening. To evaluate osteolysis, we performed CT scans in 57% (262 of 456) of patients. Kaplan-Meier survivorship analysis was performed using the endpoints of survivorship free from implant revision and survivorship free from reoperation for any cause.

RESULTS

The proportion of stem neck notching was 11% (49 of 456). There were no differences in cup abduction and anteversion between hips with notches and those without notches. Notched hips were more likely to have 28-mm than 32-mm heads (90% [44 of 49] versus 70% [285 of 407]; odds ratio 3.77 [95% CI 1.46 to 9.73]; p = 0.004). None of the 49 notched hips had a ceramic head or liner fracture or evidence of metallosis. A ceramic head fracture was reported in 2% (9 of 456); all fractures occurred in 28-mm short neck heads. A ceramic liner fracture occurred in 0.2% (1 of 456), and noise was noted in 6% (27 of 456). Acetabular osteolysis developed in 2% (7 of 456). The mHHS was 91 ± 12 points at the final follow-up. The survivorship free from implant revision was 97% (95% CI 96% to 99%), and the survivorship free from reoperation for any cause was 96% (95% CI 95% to 98%) at 13 years.

CONCLUSION

The proportion of stems with neck-ceramic liner impingement and ceramic component fracture were unacceptably high after the use of a thick-neck stem design, especially when a 28-mm head was used. We have discontinued the use of this stem design and we recommend that such stems should not be used when CoC bearings are used. As these findings might be generalized to other bearing couples, further studies focused on polyethylene liner wear and local metallosis due to thick stem neck are warranted.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is Restoration of Hip Center Mandatory for Total Hip Arthroplasty of Protrusio Acetabuli?

Purpose

While initial fixation using a press-fit of the acetabular cup is critical for the durability of the component, restoration of the hip center is regarded as an attributable factor for implant survival and successful outcome. In protrusio acetabuli (PA), obtaining both restoration of the hip center and the press-fit of the acetabular cup simultaneously might be difficult during total hip arthroplasty (THA). We tested the hypothesis that use of a medialized cup, if press-fitted, will not result in compromise of the implant stability and outcome after cementless THA of PA.

Materials and Methods

A total of 26 cementless THAs of 22 patients with PA were reviewed. During THA, press-fit of the cup was prioritized rather than hip center restoration. A press-fit was obtained in 24 hips. A press-fit could not be obtained in the two remaining hips; therefore, reinforcement acetabular components were used. Restoration of the hip center was achieved in 17 cups; 15 primary cups and two reinforcement components; it was medialized in nine cups. Implant stability and modified Harris hip score (mHHS) between the two groups were compared at a mean follow-up of 5.1 years (range, 2-16 years).

Results

Twenty-six cups; 17 restored cups and nine medialized press-fitted cups, remained stable at the latest follow-up. A similar final mHHS was observed between the restored group and the medialized group (83.6±12.1 vs 83.8±10.4, P=0.786).

Conclusion

Implant stability and favorable results were obtained by press-fitted cups, irrespective of hip center restoration. THA in PA patients showed promising clinical and radiological results.

Distribution and outliers of anteversion of short-length cementless stem

INTRODUCTION

Inadequate stem version might lead to impingement and instability after cementless total hip arthroplasty (THA). We evaluated (1) the distribution of short-stem anteversion, (2) the proportion of stems with an anteversion less than 5° or larger than 25°, (3) combined cup and stem anteversion, and (4) dislocation rate.

MATERIALS AND METHODS

We evaluated the native femoral anteversion and stem anteversion in 340 patients (340 THAs): 144 men and 196 women. Their mean age was 56.2 (22-87) years and mean body mass index was 25.1 (15.2-40.7) kg/m². The femoral neck anteversion was measured on pre-operative CT scan and the stem anteversion was obtained during the operation. The safe zone of the stem anteversion was defined as 5 to 25°.

RESULTS

The femoral neck anteversion ranged from -15 to 61° (mean, 15.0°; SD, ±10.6°). The stem anteversion ranged -7 to 50° (mean, 15.7°; SD, ±9.5°). It was optimal (5-25°) in 71.2% (242/340), insufficient (<5°) in 13.3% (45/340), and excessive (>25°) in 15.6% (53/340). The stem anteversion had a medium correlation with the femoral neck anteversion (correlation coefficient = 0.449). The combined anteversion was 42.0° (range, 35.2-52.3°; SD, ±2.8°). During two to four year follow-up, no hip dislocated.

CONCLUSIONS

Short-length stem had a great variability in the anteversion and considerable portion (28.9%, 98/340) of stems had an anteversion outside the safe zone. Surgeons should be aware of this variability of stem anteversion to compensate for abnormal stem anteversion, which might lead to impingement and instability after THA.

Posterior versus lateral surgical approach: functionality and quality of life after total hip arthroplasty in a matched cohort study

BACKGROUND

One of the most controversial aspects for maximizing outcomes after total hip arthroplasty (THA) remains the surgical approach to the hip joint. The posterior (PA) and lateral approaches (LA) are the two most commonly performed approaches used worldwide, but sparse data are available for their comparison in terms of health-related quality-of-life (HRQoL). The aim of this study was to assess the role of the PA and LA in the HRQoL and hip functionality of patients who underwent primary and elective THA for osteoarthritis, after a minimum 2-year follow-up.

METHODS

One hundred twenty-eight patients (140 THAs: 68 with PA and 72 with LA) were evaluated in a matched cohort study. Data gathered included the body mass index, the American Society of Anesthesiologists score, surgery time, serum creatine phosphokinase (CpK) levels, estimated intraoperative blood loss and intra- or postoperative complications. Preoperatively and at the last follow-up, the activities of daily living, and the instrumental activities of daily living (IADL) scales, the Western Ontario and Mac Master University (WOMAC) Questionnaire, the Harris Hip Score (HHS) and the Visual Analogue Scale (VAS) were used to assess HRQoL and functionality. The Short Form-36 Health Survey (SF-36) Questionnaire was administered at the last follow-up.

RESULTS

Postoperatively, CpK was higher in the LA group compared to the PA (695 ± 648 vs. 447 ± 326 UI/L, p < 0.001). At a mean follow-up of 47 ± 22 months for the LA group and 42 ± 29 months for the PA group, IADL, VAS, HHS and WOMAC scores significantly improved for both groups (all p < 0.001), but PA reported better VAS, residual pain and WOMAC scores (p = 0.002, p = 0.004 and p = 0.018, respectively). The PA group demonstrated a significant higher mental SF-36 subscale values than the LA group (49 ± 13 vs. 42 ± 19, p = 0.001). The LA group showed a higher number of Trendelenburg signs (p = 0.029). On the contrary, the PA group showed a higher number of leg lengthening (p = 0.020); however, most of these cases was less than the clinically significant value of 10 mm (p = 0.738).

CONCLUSIONS

Patients who underwent THA performed with the PA reported greater improvement in HRQoL with lower residual pain, postoperative muscle damage and Trendelenburg signs than those who underwent the LA.

Capsular repair vs capsulectomy in total hip arthroplasty

BACKGROUND

A major complication of total hip arthroplasty is dislocation. The hip joint capsule can be incised and repaired, or can be excised.

SOURCES OF DATA

We performed a systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines focusing on capsular repair and capsulectomy.

AREAS OF AGREEMENT

We identified 31 articles (17 272 patients). Capsular repair produced a lower blood loss (465.2 vs 709.2 ml), and the procedure lasted 102.5 vs 96.08 min in patients who underwent capsulectomy. The patients undergoing capsulectomy experienced a dislocation rate of 3.06%, whereas in the patients undergoing capsular repair, the dislocation rate was 0.65%.

AREAS OF CONTROVERSY

Most studies are retrospective observational studies, with no prospective randomized trials.

GROWING POINTS

Capsular preservation is association with a lower dislocation rate and a lower blood loss. Capsular excision does take statistically less time, but it is uncertain how a 6 min difference is clinically relevant.

AREAS TIMELY FOR DEVELOPING RESEARCH

Appropriately powered randomized clinical trials should be conducted to better define the association between the chosen implants, approach and outcome.

Can we trust combined anteversion and Lewinnek safe zone to avoid hip prosthesis dislocation?

INTRODUCTION

Dislocation is one of the most common complications after primary total hip arthroplasty (THA). Combined anteversion (CA) is currently considered one of the most important measures of stability for THA. Thus, the aim of this study is to determine the association between a correct CA after THA and hip prosthesis dislocation, and to analyze the reliability of the Lewinnek safe zone parameters.

MATERIAL AND METHODS

This is a non-interventional retrospective study, carried out at a tertiary hospital in Spain. 2489 primary THA in 2147 patients between January 2008 and December 2014 were identified. Clinical, biological and radiographic data, including cup inclination and cup and femoral anteversion, were analyzed of all patients who developed a hip prosthesis dislocation.

RESULTS

Thirty-four patients met the eligibility criteria to be analyzed. In 73.5% (25/34) of cases, acetabular anteversion (AV) was correct, with a mean AV of 15.1° ± 9.4°. Femoral anteversion (FA) was considered correct only in 38.2% (13/34) of the dislocated THA, with a mean FA of 8.4° ± 17.2°. Sixteen of these 34 patients (47.0%) presented a correct CA, with a mean CA of 24.2° ± 21.0°. Nineteen hips (55.8%) were within the Lewinnek safe zone. Moreover, eleven patients (32.3%) developed a dislocation even though components were within the Lewinnek safe zone and presented a correct CA.

CONCLUSION

Our findings suggest that even when the THA components are positioned within a correct CA and in the Lewinnek safe zone, hip prosthesis dislocations can occur in a not inconsiderable percentage of the cases. Thus, further radiological and clinical analysis should be done to identify potential reasons for hip prosthesis dislocation.

Preventing ceramic liner fracture after Delta ceramic-on-ceramic total hip arthroplasty

BACKGROUND

The results of total hip arthroplasty (THA) with use of Delta ceramic articulation were successful at medium term follow-up. The use of this newest ceramic has markedly reduced the incidence of ceramic head fractures, but not the incidence of ceramic liner fractures. We tested a hypothesis that the ceramic fractures are prevented by use of a metal shell with 18° inner taper angle and a stem design with a reduced neck geometry.

METHODS

We conducted a prospective multicenter study of cementless THA with use of 32/36-mm Delta ceramic bearing, Exceed ABT metal shell and Taperloc stem. We evaluated ceramic fracture, noise, clinical results, radiological changes and survival rate at a minimum of 5-year follow-up.

RESULTS

From April 2010 to February 2012, 246 patients (274 THAs) were enrolled. Among them, 224 patients (130 men and 94 women, 250 hips) were followed-up for 5-8 years (mean 6.0 years). Ceramic malseating or fracture did not occur in any patient. Eight patients (8 hips, 3.2%) reported noise. Mean Harris hip score was 84 points at the latest follow-up. All acetabular and femoral components had bone-ingrown stability. Two hips were revised due to recurrent dislocation and periprosthetic fracture. The survival rate was 99.6% at 8 years postoperatively.

CONCLUSION

Ceramic fractures can be prevented by a use of (1) 32/36-mm Delta ceramic bearing, (2) metal shell with 18° taper angle, and (2) stem with a reduced neck geometry. However, noise remains a concern of the Delta ceramic bearing.

LEVEL OF EVIDENCE

Therapeutic level II.

Nerve palsy, dislocation and revision rate among the approaches for total hip arthroplasty: a Bayesian network meta-analysis

BACKGROUND

Total hip arthroplasty (THA) is one of the most performed intervention in orthopaedics surgery. Currently, there is no unanimous approval concerning the best approach for THA in terms of nerve palsies, dislocations and further revisions. Hence, a Bayesian network meta-analysis was conducted.

METHODS

The present study was conducted according to the PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of healthcare interventions. The literature search was performed in September 2019. The NMA was performed through the STATA Software/MP routine for Bayesian hierarchical random-effects model analysis.

RESULTS

Data from 10,675 THA were collected. The mean follow-up was 10 months. The anterior approach reported the lowest risk to incur a post-operative dislocation (overall inconsistency P = 0.99). The posterolateral approach reported the lowest risk to incur a nerve palsy (overall inconsistency P = 0.77). The funnel plot revealed a low risk of publication bias. The lateral approach was found to have the lowest risk of resulting in a revision surgery (overall inconsistency P = 0.90).

CONCLUSION

According to our network comparisons, the posterolateral approach for THA represent the favourable exposure with regards to nerve palsy, further dislocations and revision surgeries.

No Clinically Important Differences in Thigh Pain or Bone Loss Between Short Stems and Conventional-length Stems in THA: A Randomized Clinical Trial

BACKGROUND

Short-length stems were developed to reduce bone loss of the proximal femur and potentially decrease the incidence of thigh pain after cementless THA. However, it remains unknown whether short stems indeed reduce bone loss or the frequency of thigh pain.

QUESTIONS/PURPOSES

Is there a difference between short- and standard-length stems in terms of: (1) the frequency or severity of thigh pain, (2) modified Harris hip scores, (3) implant loosening, or (4) bone mineral density as measured by dual-energy x-ray absorptiometry?

METHODS

Between March 2013 and January 2014, three surgeons performed 205 primary THAs. To be eligible, patients needed to be at least 20 years of age, have not undergone previous history of hip surgery, and have no metabolic bone disease. A total of 100 patients were randomized to receive THA either with a short stem (n = 56) or with a standard-length stem (n = 44). Both stems were proximally coated, tapered, cementless stems. Compared with standard stems, short stems typically were 30- to 35-mm shorter. A total of 73% (41 of 56) and 77% (34 of 44) of those groups, respectively, were accounted for at a minimum of 5 years and were analyzed. The presence of thigh pain during activity was evaluated using a 10-point VAS, and the modified Harris hip score was calculated by research assistants who were blinded to the treatment groups. Plain radiographs were taken at 6 weeks, 6 months, and 12 months postoperatively, and every 1 year thereafter; loosening was defined as subsidence > 3 mm or a position change > 3° on serial radiographs. Radiological assessment was performed by two researchers who did not participate in the surgery and follow-up evaluations. Bone mineral density of the proximal femur was measured using dual-energy x-ray absorptiometry at 4 days, 1 year, 2 years, and 5 years postoperatively. The primary endpoint of our study was the incidence of thigh pain during 5-year follow-up. Our study was powered at 80% to detect a 10% difference in the proportion of patients reporting thigh pain at the level of 0.05.

RESULTS

With the numbers available, we found no difference between the groups in the proportion of patients with thigh pain; 16% (9 of 56) of patients in the short-stem group and 14% (6 of 44) of patients in the standard-stem group experienced thigh pain during the follow-up period (p = 0.79). In all patients, the pain was mild or moderate (VAS score of 4 or 6 points). Among the 15 available patients who reported thigh pain, there was no difference between the implant groups in mean severity of thigh pain (4.3 ± 0.8 versus 4.2 ± 0.7; p = 0.78). There were no between-group differences in the short versus standard-length stem groups in terms of mean modified Harris hip score by 5 years after surgery (89 ± 13 versus 95 ± 7 points; p = 0.06). No implant was loose and no hip underwent revision in either group. Patients in the short-stem group showed a slightly smaller decrease in bone mineral density in Gruen Zones 2, 3, and 5 than those in the standard-stem group did; the magnitude of the difference seems unlikely to be clinically important.

CONCLUSION

We found no clinically important differences (and few differences overall) between short and standard-length THA stems 5 years after surgery in a randomized trial. Consequently, we recommend that clinicians use standard-length stems in general practice because standard-length stems have a much longer published track record in other studies, and short stems can expose patients to the uncertainty associated with novelty, without any apparent offsetting benefit.

LEVEL OF EVIDENCE

Level I, therapeutic study.

A Complication-Based Comparison Between the Posterior and Direct Lateral Approaches to Total Hip Arthroplasty: A Single-Center Experience

Introduction

Many approaches to performing total hip arthroplasty (THA) exist, primarily due to an insufficient amount of research that would favor one approach over the other. This study aimed to compare the risk of nerve injury, dislocation, Trendelenburg gait, and stem malposition between the direct lateral and posterior approaches to THA.

Methods

The study was a retrospective cohort study, and it was conducted in King Abdulaziz Medical City. It was directed toward adult patients who underwent THA from November 1, 2003, to November 1, 2018. All figures were obtained through the BESTCare system (ezCareTech, Saudi Arabia). Categorical variables were presented as frequencies and proportions. Quantitative variables were measured as mean and standard deviation. Fisher's exact test was used to compare the risk of complications between the two approaches.

Results

The posterior approach displayed a greater risk of stem malposition (p< 0.001) when compared with the direct lateral approach. However, neither approach showed a higher risk of dislocation, nerve injury, or Trendelenburg gait.

Conclusions

A higher risk of stem malposition was observed in the posterior approach, and there were no remarkable variances between the two approaches in the risk of dislocation, nerve injury, and Trendelenburg gait. Until more meticulous nationwide studies are available to provide evidence that would favor an approach over the other, the choice of surgical approach for THA remains to depend on the patient's characteristics and the surgeon's prior experience. Regardless of the approach, preoperative, intraoperative, and postoperative factors that increase the risk of complications should also be identified and addressed adequately.

Postoperative Failure Frequency of Short External Rotator and Posterior Capsule With Successful Reinsertion After Primary Total Hip Arthroplasty: An Ultrasound Assessment

BACKGROUND

The reinsertion of the short external rotators and posterior capsule to the greater trochanter in the posterolateral approach has been considered an effective strategy to reduce the risk of dislocation. However, during clinical practice, no verification and monitoring of the status of such reinsertions is carried out. The objective of this study is to estimate the frequency of postoperative failure with successful reinsertion of the short external rotator and posterior capsule of the hip through ultrasound after primary total hip arthroplasty (THA) using the posterolateral approach.

METHODS

A prospective observational study was conducted involving patients with primary total hip arthroplasty via posterolateral approach in which reinsertion of hip's short external rotators and posterior capsule were successful reinserted during surgery from January to December 2019. The status of the reinsertion was assessed with an ultrasound between the 6 and 8 weeks after surgery. Reinsertion failure was considered when the reinserted structures were not fully visualized in the ultrasound during internal and external rotation.

RESULTS

Sixty-eight patients were included in this study (mean age: 58.7 ± 13.8 years; 44.1% (30) women). The incidence of failure of the reinsertion of short external rotators and posterior capsule was 16.2% (n = 11) (95% confidence interval 9.3-26.7). A postoperative increased femoral offset was found more frequently in cases with failure (36.4% vs 17.5%); a similar trend was observed in the leg length discrepancy (36.4% vs 22.8%). However, these differences were not statistically significant (P > .05).

CONCLUSION

Between the 6th and 8th postoperative week, approximately 2 of the 10 short external rotator and posterior capsule reinsertions fail in cases with successful intraoperative repair using absorbable suture. This estimate is comparable and even lower than previous reports.

EVIDENCE LEVEL

II, Prospective Observational Study.

Total Hip Arthroplasty With Trochanteric Ostectomy for Patients With Angular Deformity of the Proximal Femur

BACKGROUND

Total hip arthroplasty (THA) of patients with a proximal femoral deformity is technically demanding. This deformity poses the risk of femoral fracture or perforation; stem malposition; and failed stem fixation. To insert a femoral stem in neutral position with a good fit, we removed the greater trochanter in case of a varus deformity, and the lesser trochanter in case of valgus deformity, while performing THA. We aimed to evaluate stem position, implant stability, clinical results, and radiological changes after THAs using this technique.

METHODS

Fifteen patients (17 hips; 11 varus hips and 6 valgus hips) underwent cementless THA using the trochanteric osteotomy technique in one institution. We evaluated procedure-specific complications: intraoperative femoral fracture, stem malposition, weakness of the abductor power and limp. Modified Harris Hip Score, radiological changes, and the stability of stems were assessed at a mean of 7.1 years of follow-up (range 2.0-15.5).

RESULTS

Femoral fracture occurred during the insertion of the stem in 4 hips. All stems were aligned in neutral position. At the latest follow-up, the mean power of the abductor was 4.3 (range 3-5). Eleven patients had slight limp and 4 patients had moderate limp. All stems had bone-ingrown stability and no stem was revised. The mean modified Harris Hip Score improved from 50 points at the preoperative evaluation to 81 points at the final follow-up.

CONCLUSION

The trochanteric excision enabled neutral insertion of cementless stem in patients with varus/valgus deformity of the proximal femur, and THA using this technique rendered favorable results.

Outcome of Ceramic-on-Ceramic Total Hip Arthroplasty with 4th Generation 36 mm Head Compared to that with 3rd Generation 28 mm Head by Propensity Score Matching

BACKGROUND

With the development of 4th generation ceramic bearing, the large ceramic head is available for ceramic-on-ceramic total hip arthroplasty (THA). This retrospective study aimed to compare the outcomes of ceramic-on-ceramic THA with 4th generation 36 mm head to those with 3rd generation 28 mm head using propensity score matching.

METHODS

We retrospectively reviewed the results of 133 ceramic-on-ceramic THAs with 4th generation 36 mm ceramic head in 129 patients and 133 ceramic-on-ceramic THAs identified from 405 ceramic-on-ceramic THAs with 3rd generation 28 mm head by propensity score matching. There were 83 males and 50 females in both groups with a mean age of 55 years. There was no significant difference in other demographic features except for follow-up period (4.2 years in the 36 mm group and 6.4 years in the 28 mm group, p < 0.001). Clinical and radiological results and occurrence of complication were compared between the two groups.

RESULTS

Harris Hip Score was increased significantly from 46.4 to 92.1 in the 36 mm group and from 46.7 to 93.6 in the 28 mm group. No loosening or osteolysis was observed in the 36 mm group. However, one hip showed radiologic sign of loosening in the 28 mm group. As for complication, postoperative dislocation was more frequent in the 28 mm group (6 in the 28 mm group vs. 0 in the 36 mm group, p = 0.03). Otherwise, there was no significant difference in other results including inguinal pain, squeaking or ceramic fracture.

CONCLUSION

Ceramic-on-ceramic THA with 4th generation 36 mm head significantly reduced postoperative dislocation rate without increasing the rate of inguinal pain, squeaking, or ceramic fracture compared to that with 3rd generation 28 mm head.

The effect of surgical approach in total hip replacement on outcomes: an analysis of 723,904 elective operations from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

Total hip replacement (THR) is clinically and cost-effective. The surgical approach employed influences the outcome; however, there is little generalisable and robust evidence to guide practice.

METHODS

A total of 723,904 primary THRs captured in the National Joint Registry, linked to hospital inpatient, mortality and patient-reported outcome measures (PROMs) data with up to 13.75 years follow-up, were analysed. There were seven surgical approach groups: conventional posterior, lateral, anterior and trans-trochanteric groups and minimally invasive posterior, lateral and anterior. Survival methods were used to compare revision rates and 90-day mortality. Groups were compared using Cox proportional hazards and Flexible Parametric Survival Modelling (FPM). Confounders included age at surgery, sex, risk group (indications additional to osteoarthritis), American Society of Anesthesiologists grade, THR fixation, thromboprophylaxis, anaesthetic, body mass index (BMI) and deprivation. PROMs were analysed with regression modelling or non-parametric methods.

RESULTS

Unadjusted analysis showed a higher revision risk than the referent conventional posterior for the conventional lateral, minimally invasive lateral, minimally invasive anterior and trans-trochanteric groups. This persisted with all adjusted FPM and adjusted Cox models, except in the Cox model including BMI where the higher revision rate only persisted for the conventional lateral approach (hazard rate ratio (HRR) 1.12 [95% CI 1.06,1.17] P < 0·001) and trans-trochanteric approaches (HRR 1.48 [95% CI 1.14,1.91] P = 0.003). PROMs demonstrated statistically, but not clinically, significant differences. Self-reported complications were more frequent with the conventional lateral approach, and the risk of 90-day mortality was higher (HRR 1.15 [95%CI 1.01-1.30] P = 0.029).

CONCLUSIONS

Lateral approaches for THR are associated with worse outcomes, including more deaths and revisions, than the posterior approach. We recommend the posterior approach should be considered the current standard approach for THR. Large well-designed studies are needed to assess any potential benefits from using minimally invasive posterior approaches and the conventional anterior approach.

Implant positioning among the surgical approaches for total hip arthroplasty: a Bayesian network meta-analysis

INTRODUCTION

Although there is anatomical individuality among patients, some standardized requirements for component orientation for total hip arthroplasty (THA) exist. To date, no study has compared implant positioning using a network meta-analysis (NMA). Hence, the purpose of this study was to perform a NMA comparing implant positioning among the various approaches for THA.

METHODS

This study was conducted according to the PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interventions. All randomized (RCT) and non-randomized (nRCT) clinical trials comparing two or more different approaches for THA were considered for inclusion. For the statistical analysis, the STATA Software/ MP, Version 14.1 (Stata Corporation, College Station, Texas, USA) was used. The NMA was performed through a Stata routine for Bayesian hierarchical random-effects model analysis.

RESULTS

We enrolled in the present study, a total of 4060 patients, with a mean of 17.84 ± 16.41 months follow-up. The patient baseline data were very homogeneous across the groups concerning age (P = 0.91), sex (P = 0.52), and BMI (P = 0.83). Concerning the cup anteversion, the anterolateral approach reported the value closest to the reference value. The test for overall inconsistency, however, was not statistically significant (P = 0.30). Concerning cup inclination, the lateral approach reported the value closest to the reference value. The test for overall inconsistency was statistically significant (P = 0.01).

CONCLUSION

The anterolateral approach for total hip arthroplasty detected the best femoral stem alignment and cup anteversion. Data concerning cup inclination detected no sufficient transitivity to draw consistent conclusions.

Disadvantage during Perioperative Period of Total Hip Arthroplasty Using the Direct Anterior Approach: a Network Meta-Analysis

BACKGROUND

The purpose of this study was to analyze complications of complete hip arthroplasty through systematic review and network meta-analysis of comparative studies of direct anterior approach (DAA), anterolateral approach (LA), and posterolateral approach (PA).

METHODS

Prospective randomized controlled trials (RCTs) or quasi-experimental designs evaluating clinical outcomes of DAA, LA, and PA for complete hip arthroplasty are valid if they meet the following criteria: 1) Comparison of clinical outcomes between the three methods for main complete hip arthroplasty (total hip arthroplasty, THA); 2) Compared at least one of the following outcomes: blood loss, operating time, and transfusion volume; 3) Sufficient data were available to extract and pool, i.e., mean reported, standard deviation and number of subjects. A network meta-analysis was used to determine the results of treatment across various surgical approaches. Indirect comparisons between the two surgical approaches was made by borrowing details from the standard comparator (i.e., the posterior approach).

RESULTS

Eight prospective RCTs were included in the meta-analysis of the network. The operation time of the LA was longer than that of PA (standardized mean difference [SMD], 0.96; 95% confidence interval [CI], 0.74-1.18; P < 0.001). DAA also had significantly longer operation time than PA (SMD, 0.45; 95% CI, 0.24-0.66; P < 0.001). However, blood loss of the DAA was the highest compared to other approaches (SMD, 0.60; 95% CI, 0.39-0.82; P = 0.002).

CONCLUSION

When performing THA with DAA, we should pay attention to increased operation time and blood loss.

Comparison of Bone Preservation in Elderly Patients with Femoral Neck Fracture After Bipolar Hemiarthroplasty Using Shorter Femoral Stem and Standard Femoral Stem

BACKGROUND

This randomized control study was designed to compare the clinical and radiological outcomes, including periprosthetic bone mineral density (BMD) changes, between the short and standard stems after using cementless hemiarthroplasty in elderly patients with femur neck fractures.

MATERIALS AND METHODS

From January 2013 to May 2017, 151 patients (aged ≥ 65 years) underwent hemiarthroplasties due to femoral neck fractures. Patients were randomized into two groups; 77 patients in Group A implanting the short femoral stem and 74 patients in Group B implanting the standard femoral stem. Clinical and radiographic evaluations were performed in all patients.

RESULTS

75 patients (40 patients in Group A and 35 patients in Group B) completed routine follow-up for a minimum of 2 years. The clinical outcomes, including ambulatory functions and thigh pain, were similar in both groups. All the femoral stems acquired radiologic stability. At postoperative one year, BMD values in Gruen zone (G) seven on the standard stem side were significantly lower than those on the short stem side (P = 0.038). At the second year of follow-up, the BMD values of Group A in G1, G3, G4, and G7 were significantly greater than those of Group B (P = 0.007, 0.032, 0.026, and P < 0.000, respectively).

CONCLUSIONS

Both the clinical outcomes and radiologic stability in both group demonstrated similar results in elderly patients with femoral neck fracture at the latest follow-up. In addition, the periprosthetic BMD of the short femoral stems demonstrated better periprosthetic bone preservation at a minimum of 2 years of follow-up.

LEVEL OF EVIDENCES

Therapeutic Level II.

Use of ceramic-on-ceramic bearing in total hip arthroplasty for posttraumatic arthritis of the hip

PURPOSE

We aimed to evaluate (1) the intraoperative parameters, (2) cup position, (3) complications, (4) long-term results, and (5) the survivorship of cementless total hip arthroplastys (THAs) with use of ceramic bearings in patients with a history of acetabular fracture.

METHODS

We compared 57 THAs in patients, who were treated due to previous acetabular fracture (posttraumatic group), with 57 propensity score-matched THAs in patients, who were operated due to femoral head osteonecrosis (osteonecrotic group), at a minimum of 5-year follow-up.

RESULTS

The operation time was longer ( p = 0.008), and the volume of transfusion was larger ( p = 0.0.23) in the posttraumatic group. The cup abduction (39.4° ± 6.0° vs. 39.7°±4.8°) and anteversion (24.7° ± 8.0° vs. 26.7°±7.7°) were similar between the two groups. There was one dislocation in the posttraumatic group. There was no ceramic fracture in either group. One posttraumatic patient underwent excision of exuberant heterotrophic ossification at 3 years after the arthroplasty. The mean University of California, Los Angeles activity improved from 3.6 to 4.9 points in the posttraumatic group and 3.5 to 5.2 points in the osteonecrotic group. All acetabular cups and femoral stems had bone-ingrown stability. When reoperation for any reason was used as the end point, the 10-year survival rate was 98.3% (95% CI: 95.0-100) in the posttraumatic group and 100% in the osteonecrotic group.

CONCLUSION

In our study, posttraumatic patients had longer operation time and larger volume of transfusion than osteonecrotic patients. However, medium-term results and survivorship were similar with those of osteonecrotic patients.

Hospitalization length, surgical duration, and blood lost among the approaches for total hip arthroplasty: a Bayesian network meta-analysis

Despite the numerous studies, there is no consensus concerning the best approach for total hip arthroplasty (THA), and debates are ongoing. The purpose of this study was to perform a Bayesian network meta-analysis (NMA) comparing several approaches for primary THA. The focus was on peri-operative outcomes: surgical duration, total estimated blood loss, and length of the hospitalization. This Bayesian network meta-analysis was conducted according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of health care interventions. In October 2019, the main databases were accessed. All the clinical trials comparing two or more different approaches for primary THA were assessed. For the methodology quality assessment, the PEDro score was performed. The Software STATA MP was used for the statistical analyses. The NMA was performed through the routine for Bayesian hierarchical random-effects analysis with the inverse variance statistic method for continuous variables. Data from 4843 procedures was analysed. Between patient's demographic, good baseline comparability was found. The comparison total estimated blood loss detected statistically significant inconsistency (P = 0.01). The posterolateral approach reported the lowest value for the surgical duration. The test for overall inconsistency was statistically significant (P = 0.4). The posterolateral approach reported the shortest hospitalization length. The test for overall inconsistency was statistically significant (P = 0.9). The posterolateral approach reported shorter surgical duration and hospitalization length. Concerning the analysis of total estimated blood loss, no significant result was obtained. Data must be considered in the light of the limitations of the present study.

Capsular closure outweighs head size in preventing dislocation following revision total hip arthroplasty

INTRODUCTION

The high dislocation rate following revision total hip arthroplasty (THA) has been shown to be significantly reduced by closing the posterior capsule and by the use of large diameter femoral heads. The relative importance of each of these strategies on the rate of dislocation remains unknown. We undertook a study to determine if increasing femoral head diameter, in addition to posterior capsular closure would influence the dislocation rate following revision THA.

METHODS

We retrospectively reviewed 144 patients who underwent a revision THA. We included all patients who underwent revision THA with closure of the posterior capsule and who had at least a 2-year minimum follow-up. 48 patients had a 28-mm femoral head, 47 had a 32-mm head and 49 patients had a 36-mm femoral head.

RESULTS

At a minimum follow-up of 2 years, there were 3 dislocations. There were no dislocations in the 28-mm group (0%), 2 in the 32-mm group (4%) and 1 in the 36-mm group (2%). Head size alone was not found to significantly decrease the risk of dislocation (28-mm versus 32-mm p = 0.12; 28-mm versus 36-mm p = 0.27; 32-mm versus 36-mm p = 0.40).

CONCLUSION

Both large diameter heads and careful attention to surgical technique with posterior capsular closure can decrease the historically high dislocation rate after revision THA when utilising the posterolateral approach. Capsular closure outweighs the effect of femoral head diameter in preventing dislocation following revision THA through a posterolateral approach.

Effect of articular capsule repair on postoperative dislocation after primary total hip replacement by the anterolateral approach

Objective

Artificial hip dislocation is one of the most serious complications following total hip replacement. This study was performed to assess articular capsule repair in primary total hip replacement with the anterolateral approach (Watson-Jones incision) and its effect on postoperative dislocation.

Methods

Patients who underwent primary total hip replacement by the anterolateral approach in Tongren Hospital of Shanghai Jiao Tong University School of Medicine from June 2007 to June 2014 were retrospectively analyzed. The patients were divided into the repair and dissection groups based on the articular capsule repair status during surgery. Postoperative dislocation rates were compared between the two groups using the chi-squared test.

Results

The repair and dissection groups comprised 137 and 248 patients, respectively. All patients were followed up for 6 months to 5 years (average, 3.75 years). The mean age, sex, disease composition, and follow-up time were not significantly different between the two groups. Early postoperative dislocation occurred in 1 hip (0.7%) in the repair group and 13 hips (5.2%) in the dissection group.

Conclusions

During the anterolateral approach for primary total hip replacement, articular capsule repair may reduce the occurrence of early postoperative dislocation of the hip joint.

Comparative outcomes between collared versus collarless and short versus long stem of direct anterior approach total hip arthroplasty: a systematic review and indirect meta-analysis

INTRODUCTION

Early research shows several advantages of the direct anterior approach (DAA) in THA that claimed to be as effective but less invasive than the posterior approach. However, due to the difficult femoral exposure and possible complications related to femoral preparation, this approach may result in a higher rate of undersized stems when compared to other approaches. The present authors believe that the femoral implant design (collar or collarless stem, short or long stem) in a collared femoral stem may relate to lower rates of stem subsidence and limb length discrepancy (LLD) in mid-term to long-term follow-up when compared to collarless femoral stems. However, currently, there is no consensus as to which femoral implant design is the most suitable for DAA in THA.

METHODS

This systematic review and meta-analysis aim to assess and compare postoperative complications (neurapraxia, wound infection, LFCN, hematoma, artery injury, cup malposition, embolism, fracture and implant loosening) and revision rates due to dislocation, periprosthetic fracture and implant migration after DAA using collared compared to collarless femoral stem and short femoral stem compared to long femoral stem in THA. These clinical outcomes consist of the postoperative complications and revision femoral stem due to neurapraxia, wound, LFCN and LLD. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Relevant studies that reported postoperative complications and revision of either implant were identified from Medline and Scopus from inception to June 6, 2018. Thirty-four studies were included for the analysis of DAA in THA; 23 studies were retrospective cohorts, four studies were prospective cohorts, and seven studies were RCTs. Thirty-one studies and three studies were included for analysis of collarless and collared femoral stems. Twenty-six studies were long femoral stems and eight studies were short femoral stems. Overall, there were 6825 patients (6457 in the collarless group and 368 in the collared group, 4280 in long stem and 2545 in short stem). A total of 469 and 66 patients had complications and revisions in the collarless group, and no patient had complications and revisions in the collared stem group. The total complication and revision rate per patient were 5% (95%CI 3.3%, 7%) and 0.9% (95%CI 0.6%, 1.2%) in all patients. The complication rate and revision rate were 5.7% (95%CI 3.8%, 7.7%) and 0.9% (95%CI 0.6, 1.2) in the collarless group. There was no prevalence of complications and revisions in the collared stem group. The complication rate and revision rate were 10.2% (95%CI 9%, 11.4%), 0.7% (95%CI 0.3%, 1%) and 5.2% (95%CI 3.1, 7.2), 1.5% (95%CI 1%, 2%) in short and long femoral stems, respectively. Indirect meta-analysis shows that collared femoral stem provided a lower risk of complications of 0.02 (95%CI 0.001, 0.30) when compared to collarless femoral stem. Long femoral stems had a lower risk of having complications of 0.57 (95%CI 0.48, 0.68) when compared to short femoral stems. In terms of revision, there is no statistically significant difference in collared femoral stem compared to collarless femoral stem and long femoral stem compared to short femoral stem.

CONCLUSION

In DAA THA, collared femoral stem and long femoral stem had decreased complication rates when compared to collarless femoral stem and short femoral stem by both direct and indirect meta-analysis methods. However, in terms of revision rates, there were no differences between all femoral stems (short versus long and collared versus collarless). Prospective randomized controlled studies are needed to confirm these findings as the current literature is still insufficient.

Limping Following Primary Total Hip Replacement: Comparison of 3 Surgical Approaches

Background

Limping following total hip replacement affects clinical outcome and patient satisfaction. The purpose of the present study was to determine the prevalence of limping following the posterior approach, the direct lateral approach, and the modified anterolateral Watson-Jones approach for primary total hip replacement, performed by 1 surgeon.

Methods

We retrospectively reviewed the records for 152 patients who had undergone unilateral primary total hip replacement and assessed the prevalence of limping ≥2 years after surgery as a function of the surgical approach. Patients were divided into 3 groups, according to the surgical approach: (1) 43 patients, posterior approach; (2) 53 patients, direct lateral approach; and (3) 56 patients, modified anterolateral Watson-Jones approach. The mean duration of follow-up was 65.04 months (range, 24 to 117 months). No patients were lost to follow-up.

Results

There were no significant differences between the groups in terms of the limping rates (6.98%, 7.55%, and 3.57% for the posterior approach, direct lateral approach, and modified anterolateral Watson-Jones approach, respectively; p = 0.64). No patient had severe limping. The Harris hip score, the alignment of the acetabular component, and blood loss were not significantly different between the 3 groups. However, operative time was significantly longer for the modified anterolateral Watson-Jones approach (p = 0.001).

Conclusions

The prevalence of limping was similar ≥2 years after primary total hip replacement, irrespective of the surgical approach.

Level of Evidence

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

Early dislocation in primary total hip arthroplasty using a posterior approach with repair of capsule and external rotators

OBJECTIVE

To determine the incidence of dislocation after primary total hip arthroplasty using a posterior approach with repair of capsule and transosseous external rotators.

MATERIAL AND METHOD

Historical cohort study between January 2009 and December 2015 of all the cases of dislocation of primary total hip arthroplasty operated using a posterior approach with repair of capsule and transosseous external rotators. Demographic and clinical data concerning the patient, surgery and dislocation were collected and analyzed. A descriptive analysis and a study of survival and risk function were performed by Kaplan Meier's method considering the appearance of a hip dislocation as the final event.

RESULTS

The incidence of dislocation in our study was 1.2% (23 patients). In our study, the highest probability of dislocation occurred in the first 120 days. Forty-three point 5percent of the dislocated patients needed revision surgery.

CONCLUSIONS

Capsular repair and transosseous reattachment of the external rotators can help to reduce the incidence of dislocation in patients undergoing primary total hip arthroplasty through a posterior approach.

Using Ceramic-on-Ceramic Bearings in Total Hip Arthroplasty Necessitating 44- or 46-mm Metal Shells

Ceramic-on-ceramic articulation shows the lowest wear, with a low incidence of osteolysis. A small cup limits options regarding liner thickness and femoral implant size. The purpose of this study was to evaluate the safety of a 4-mm-thick ceramic liner and the outcomes of cementless total hip arthroplasty using a 44- or 46-mm metal shell and a ceramic-on-ceramic bearing at mid- to long-term follow-up. Between May 2003 and June 2008, 80 patients (88 hips) who had hip osteoarthritis and a hypoplastic acetabulum underwent cementless total hip arthroplasty using a 44- or 46-mm metal shell and a ceramic-on-ceramic bearing. Sixty-eight of these patients (76 hips) were followed for an average of 8 years. The ceramic-related complications, clinical and radiological results, and Kaplan-Meier survivorship of these patients were evaluated. Mean Harris hip score had improved to 88 points (range, 49-100 points) at final follow-up. No ceramic fractures occurred during follow-up. All acetabular and femoral prostheses had bone ingrowth, and there was no measurable wear in any hip. In 1 patient, a radiolucent lesion occurred around the acetabular cup. Two hips underwent revision because of periprosthetic fractures. The survival rates of the acetabular cups and the femoral stems were 100% and 97.4%, respectively. The thin (4 mm) ceramic liner did not increase the risk of ceramic fracture and did not affect the mid- to long-term results and survival of cementless total hip arthroplasty using 44- or 46-mm metal shells. [Orthopedics. 2018; 41(3):e354-e359.].

Mid-Term Survivals After Cementless Bipolar Hemiarthroplasty for Unstable Intertrochanteric Fractures in Elderly Patients

BACKGROUND

Treatment of unstable intertrochanteric fracture in elderly patients remains challenging. The purpose of this prospective study is to determine clinical and radiological results of cementless bipolar hemiarthroplasty using a fully porous-coated stem in osteoporotic elderly patients with unstable intertrochanteric fractures with follow-up over 5 years.

METHODS

From January 2010 to December 2011, we performed 123 cementless bipolar hemiarthroplasties using fully porous-coated stem to treat unstable intertrochanteric fractures in elderly patients with osteoporosis. Clinical and radiographic evaluations were performed.

RESULTS

Fifty-three patients died and 14 patients were lost during the follow-up period. Mean follow-up period was 61.8 months postoperatively. Their mean Harris hip score was 77 points (range 36-100). None of these hips had loosening of the stem or osteolysis. Postoperative complications included nonunion of greater trochanter in 2 hips and dislocation in 2 hips. Two patients were reoperated due to periprosthetic fracture. One patient underwent implant revision due to periprosthetic infection. Thirty-one patients maintained walking activities similar to those before fracture. With follow-up period of 83 months, cumulative survival rates were 97.3% and 99.1% with reoperation for any reason and femoral stem revision as endpoint, respectively.

CONCLUSION

Cementless bipolar hemiarthroplasty using a fully porous-coated stem is a useful surgical treatment option for unstable intertrochanteric fracture in elderly patients with osteoporosis.

A new system of computer-assisted navigation leading to reduction in operating time in uncemented total hip replacement in a matched population

Computer-assisted navigation techniques are used to optimise component placement and alignment in total hip replacement. It has developed in the last 10 years but despite its advantages only 0.3% of all total hip replacements in England and Wales are done using computer navigation. One of the reasons for this is that computer-assisted technology increases operative time. A new method of pelvic registration has been developed without the need to register the anterior pelvic plane (BrainLab hip 6.0) which has shown to improve the accuracy of THR. The purpose of this study was to find out if the new method reduces the operating time. This was a retrospective analysis of comparing operating time in computer navigated primary uncemented total hip replacement using two methods of registration. Group 1 included 128 cases that were performed using BrainLab versions 2.1-5.1. This version relied on the acquisition of the anterior pelvic plane for registration. Group 2 included 128 cases that were performed using the newest navigation software, BrainLab hip 6.0 (registration possible with the patient in the lateral decubitus position). The operating time was 65.79 (40-98) minutes using the old method of registration and was 50.87 (33-74) minutes using the new method of registration. This difference was statistically significant. The body mass index (BMI) was comparable in both groups. The study supports the use of new method of registration in improving the operating time in computer navigated primary uncemented total hip replacements.

A multimodal approach prevents instability after total hip arthroplasty: A 1 year follow-up prospective study

INTRODUCTION

Joint dislocation is one of the most frequent complications after hip arthroplasty. Multiple strategies have demonstrated ability to prevent instability when used in isolation, but the effect when more than one intervention is implemented has not been measured. The purpose of this study is to assess the rate of dislocation after implementation of a protocol of combined strategies for prevention of instability.

MATERIALS AND METHODS

Consecutive patients undergoing primary total hip replacement for hip osteoarthritis between February 2012 and June 2014 were included. A multimodal protocol including patient education, use of large femoral heads, posterior soft-tissue repair, and intraoperative adjustment of limb length and hip offset was applied. Dislocation episodes were documented trough medical records review and a telephonic follow-up at 3 and 12 months after surgery.

RESULTS

During the period of study 331 patients were included, mean age was 66 years and 68.8% were females. Only 0.91% of patients were lost to follow-up. Eighty-nine percent of patients received all interventions. Cumulative dislocation rate at 3 months was 0.60% and 0.90% at 12 months.

CONCLUSIONS

The implementation of a multimodal protocol for prevention of prosthesis instability produces a low rate of dislocation, which compares favorably with benchmarks. We recommend the use of a combination of multiple interventions to prevent this complication.

Trochantoplasty for Total Hip Arthroplasty in Patients With Coxa Vara Deformity

BACKGROUND

In total hip arthroplasty (THA) of hips with coxa vara, the femoral stems might be inserted in a varus alignment. To avoid varus insertion, we designed a technique, which we termed "trochantoplasty." In this procedure, the medial half of the greater trochanter was removed during THA.

METHODS

We evaluated 30 patients (31 hips) who had coxa vara deformity and underwent THA using trochantoplasty at the mean follow-up of 5 years (range, 3-9 years).

RESULTS

All stems were inserted in the neutral position. One Vancouver type 1 periprosthetic femoral fracture occurred after a fall at postoperative 2 months. At the latest follow-up, the mean power of abductor was 4.3 (range, 3-5). Four patients had moderate limp whereas 26 patients had slight limp. The abduction at 90° flexion ranged from 15° to 45° (mean, 35°). There was no revision. All prostheses had bone-ingrown stability without any detectable wear or osteolysis. The mean Harris hip score was improved from 66.9 to 89.4 points.

CONCLUSION

Trochantoplasty can be used to avoid varus insertion of the femoral stem while performing THA in patients with coxa vara deformity without compromising the abductor mechanism.

Mid-term results of the BIOLOX delta ceramic-on-ceramic total hip arthroplasty

Aims

We conducted a prospective study of a delta ceramic total hip arthroplasty (THA) to determine the rate of ceramic fracture, to characterise post-operative noise, and to evaluate the mid-term results and survivorship.

Patients and Methods

Between March 2009 and March 2011, 274 patients (310 hips) underwent cementless THA using a delta ceramic femoral head and liner. At each follow-up, clinical and radiological outcomes were recorded. A Kaplan-Meier analysis was undertaken to estimate survival.

Results

Four patients (four hips) died and 18 patients (20 hips) were lost to follow-up within five years. The remaining 252 patients (286 hips) were followed for a mean of 66.5 months (60 to 84). There were 144 men (166 hips) and 108 women (120 hips) with a mean age of 49.7 years (16 to 83) at surgery. The mean pre-operative Harris Hip Score of 47.1 points improved to 93.8 points at final follow-up. Six patients reported squeaking in seven hips; however, none were audible. Radiolucent lines involving Gruen zones one and/or seven were seen in 52 hips (18.2%). No hip had detectable wear, focal osteolysis or signs of loosening. One hip was revised because of fracture of the ceramic liner, which occurred due to an undetected malseating of the ceramic liner at the time of surgery. One hip was revised for a periprosthetic fracture of the femur, and one hip was treated for periprosthetic joint infection. The six-year survivorship with re-operation for any reason as the endpoint was 99.0% (95% confidence interval 97.8% to 100%).

Discussion

The rate of delta ceramic fracture was 0.3% (one of 286). While ceramic head fracture was dominant in previous ceramic-on-ceramic THA, fracture of the delta ceramic liner due to malseating is a concern. Cite this article: Bone Joint J 2017;99-B:741–8.

Conversion Hip Arthroplasty in Failed Fixation of Intertrochanteric Fracture: A Propensity Score Matching Study

BACKGROUND

Conversion hip arthroplasty is a salvage procedure for failed internal fixation of intertrochanteric fractures. However, the technical difficulties and perioperative morbidity of conversion arthroplasty are uncertain.

METHODS

We compared the type of arthroplasty (total hip arthroplasty or hemiarthroplasty), operative parameters, perioperative morbidity, 1-year mortality, implant stability, and clinical results of 33 conversion hip arthroplasties due to a failed internal fixation of intertrochanteric fracture with those of a matched control group of 33 primary hip arthroplasties due to the same fracture. Propensity score was used for the control matching of gender, age, and body mass index.

RESULTS

Total hip arthroplasty was more frequently performed in the conversion group (10/33) compared to the primary group (3/33) (P = .016). The operation time, perioperative blood loss, amount of transfusion, and risk of femoral fracture during the operation were increased in the conversion group. The overall 1-year mortality was 3% (1 patient) in the conversion group and 9% (3 patients) in the primary group (P = .307). At a mean of 3-year follow-up, there was no significant difference in clinical results and none of the implants were loose in both groups.

CONCLUSION

In patients with failed internal fixation of intertrochanteric fracture, conversion hip arthroplasty should be planned and executed, bearing in mind the increased operative morbidities corresponding to operation time, perioperative blood loss, requirement of transfusion, and intraoperative femoral fracture.

Total hip arthroplasty using a monobloc cementless femoral stem for patients with childhood Perthes’ disease

Aims

Modular or custom-made femoral components have been preferred for total hip arthroplasty (THA) in patients with a history of Perthes’ disease because of the distortion in the anatomy of the proximal femur. However, it has not been established whether a monobloc cementless stem will fit the distorted proximal femur or whether the results of the procedure are satisfactory in this group of patients.

Patients and Methods

We reviewed 68 consecutive patients who had undergone THA for childhood Perthes’ disease between June 2003 and December 2008. There were 35 men and 33 women with a mean age of 48 years (16 to 73) at the time of index arthroplasty. Their mean body mass index was 24.4 (18.3 to 32.9). Of the 68 hips, 32 were classified as Stulberg class III and 36 as class IV. The mean pre-operative shortening of the affected leg was 17.2 mm (5 to 34). The minimum follow-up was five years (mean 8.5 years; 5.2 to 10).

Results

An intra-operative calcar fracture occurred in eight hips (11.8%) and was successfully treated by cerclage wiring. The mean stem version was 14.6° (-2.3 to 30; standard deviation (sd) 7.3). The mean acetabular component abduction was 40.2° (23.7 to 56.0; sd 6.5) and the mean anteversion 28.3° (6.4 to 43.0; sd 7.6), respectively. The mean follow-up was 8.5 years (5.2 to 10). No dislocations occurred and no hips were revised during the course of the study. At final follow-up, the mean Harris Hip Score was 91 points (59 to 100) and the mean University of California, Los Angeles activity score was 3.2 (2 to 8).

Conclusion

Monobloc cementless stems reliably restore the anatomy in Perthes’ disease at THA without the need for custom-made or modular implants. Cite this article: Bone Joint J 2017;99-B:440–444.

New Approach and Stem Increased Femoral Revision Rate in Total Hip Arthroplasty

This study compared the femoral stem revision and loosening rates in primary total hip arthroplasty between 2 different approaches and stem designs. Recent reports comparing the direct anterior approach with either the posterior or lateral approach showed that patients undergoing the direct anterior approach have less pain and an accelerated functional recovery in the early postoperative period. After converting to an anterior approach, the authors observed an increased rate of femoral stem revision. From 2003 to 2009, a posterior or lateral approach was used to insert 514 stems of 2 designs. These cases included the use of an extensively coated cobalt-chrome stem (n=232) or a straight, dual-tapered, proximally porous-coated titanium stem (n=282). In the following years, from 2009 to 2012, 594 short, proximally coated, titanium tapered-wedge stems were inserted through a direct anterior approach. The revision rates of femoral stems inserted through a posterior approach or a lateral approach were compared with those inserted via a direct anterior approach. No stem revisions occurred in the posterior approach group or the lateral approach group, and 5 stems were revised in the anterior approach group for periprosthetic fracture or aseptic loosening (0.8%). Significantly more stem revisions occurred after the use of the new stem design and a direct anterior approach (P=.04).

Evaluation and management of chronic total hip instability

Given the increasing number of total hip arthroplasty procedures being performed annually, it is imperative that orthopaedic surgeons understand factors responsible for instability. In order to treat this potentially complex problem, we recommend correctly classifying the type of instability present based on component position, abductor function, impingement, and polyethylene wear. Correct classification allows the treating surgeon to choose the appropriate revision option that ultimately will allow for the best potential outcome.

Could larger diameter of 4th generation ceramic bearing decrease the rate of dislocation after THA?

BACKGROUND

Fourth generation (Delta) ceramic bearing was developed to reduce dislocation after total hip arthroplasty (THA) by increasing the head diameter. We tested a hypothesis that 32/36 mm Delta ceramic bearing decreases the dislocation rate. We also evaluated ceramic-related complications and early outcome of this thin liner-on-large head ceramic bearing.

METHODS

We performed a prospective study on patients who underwent THA with use of 32/36 mm Delta ceramic bearing. The dislocation rate was compared with the historical dislocation rate of third generation 28 mm ceramic bearing. We also evaluated ceramic fracture, squeak, short-term results and survival. Follow-up period was minimum 2 years.

RESULTS

Between April 2010 and February 2012, we enrolled 250 consecutive patients (278 hips). All patients received cementless prostheses. Four patients (4 hips) who received metal shells ≤ 46 mm and 28 mm heads were excluded. Three patients died and 2 patients were lost within 2 years. The remaining 241 patients (269 hips) were followed for 24-46 months. There were 142 men (161 hips) and 99 women (108 hips) with a mean age of 53.7 years (range, 17-75 years) at the index operation. Dislocation occurred in three hips (1.1%). An old age was a risk factor for dislocation. Ceramic fracture and squeaking did not occur in any patient. Mean Harris hip score was 90.3 points at the latest follow-up. All acetabular and femoral components had bone-ingrowth stability. No hip had detectable wear or osteolysis. The survival was 99.3% in the best case scenario and 97.8% in the worst at 48 months.

CONCLUSIONS

Total hip arthroplasty with use of 32/36 mm Delta ceramic bearing showed lower incidence of hip dislocation compared with 28 mm third generation ceramic bearing. A caution should be paid to prevent a fall in senile patients even though a large head is used. The short-term results of THA with this type of ceramic articulation are encouraging and we did not find any ceramic-related complications.

Combined Anterior and Posterior Approach in Total Hip Arthroplasty for Crowe IV Dysplasia or Ankylosed Hips

We evaluated 70 patients (71 hips) who underwent complex total hip arthroplasty (THA) through the combined anterior and posterior approach. Sixty-five patients (32 dislocated hips and 34 ankylosed hips) were followed-up at a minimum of 3 years (median, 6 years; range, 3-10 years). Seven patients (10.6%), who had transient paresthesia on the anterior thigh, recovered within 3 months. All patients had a good clinical outcome in terms of range of motion, pain and recovery of walking. At the latest follow-up, all prostheses had bone-ingrown stability without any detectable wear or osteolysis. The combined approach allows an excellent exposure of the acetabulum for accurate cup alignment, leg lengthening and mobilization of joint in complex THA without trochanteric osteotomy, excessive abductor release and femoral shortening osteotomy.