Posterior versus lateral surgical approach for total hip arthroplasty in adults with osteoarthritis

[Standard and special liner in primary hip arthroplasty : Current study and survey results from the German Arthroplasty Registry (EPRD)]

BACKGROUND

Instability constitutes the main reason for revision hip arthroplasties. Modified polyethylene liners are designed to improve the stability of a hip replacement. In July 2022 The Bone & Joint Journal published a study with data of the German Arthroplasty Registry (EPRD). The study investigated mechanical failure of standard and modified liner designs in primary, cementless total hip arthroplasty. Following the study, the EPRD conducted a survey of German clinics to research the utilization of lipped liners in primary total hip replacement.

METHODS

The liner study included 151,096 primary, elective, cementless total hip arthroplasties. Data from November 2012 to November 2020 were obtained from the EPRD. Standard polyethylene liners were compared with lipped, angulated, offset and angulated/offset inlays. Cumulative incidences for endpoint revision due to mechanical complication were calculated with a competing risk analysis. The influence of other variables was investigated with a multivariate Cox regression. In the following online survey, 237 out of 789 hospitals completed a form.

RESULTS AND CONCLUSION

In our analysis, only offset liners were, compared to standard liners, associated with a reduced risk of mechanical failure in a short to medium follow up. However, the resultant joint reaction force is increased with offset liners due to the lateralization of the hip center of rotation. Thus, the long-term performance of offset liners needs to be observed. Our survey indicated that lipped liners were implanted more often if the posterior approach was used. Moreover, lipped liners were mostly positioned with the elevated rim in the biomechanically less optimal posterior-superior quadrant. To improve stability it is suggested to position the elevated rim in the posterior-inferior quadrant.

Difference in Muscle Strength and Functional Outcome in Direct Lateral Approach versus Posterior Approach in Total Hip Arthroplasty: A Prospective Cohort Study

Background and Purpose

The choice between posterior approach (PA) and direct lateral approach (DLA) for total hip arthroplasty (THA) remains a contentious issue regarding clinical outcome optimization and restoring patient function. Previous studies have evaluated the postsurgical outcomes mostly in the form of Harris hip score (HHS), and the data to objectively measure the postoperative muscle power is scarce. We intend to objectively compare the hip abduction and extension strengths and other functional outcomes with a very simple tool in PA and DLA in the Indian population as most patients do not undergo as intensive rehabilitation in the postoperative period as in the western world.

Materials and Methods

A total of 158 patients underwent THA during the study period, of which 48 met inclusion criteria and only 42 completed 6 months follow-up. Patients were evaluated preoperatively, postoperatively at 2 weeks, 6 weeks, 3 months, and 6 months follow-up. At each visit, muscle strength was tested using a customized sling device mounted on a pulling apparatus fitted on the wall, as well as a pain score (VAS), Harris hip score (HHS), and Short Form Survey (SF-36).

Results

The study showed statistically significant better hip muscle strength at 2 weeks postoperative for leg press test and 2 weeks as well as 6 weeks postoperative for hip abduction strength in the PA. However, no differences were noted during the 3 or 6 months follow-up period among the DLA and PA. The surgical approach used has no effect on VAS, HHS, or SF-36 scorings.

Conclusion

The weak abductor mechanism at 2 and 6 weeks and extension mechanism at 2 weeks in a cohort of DLA in contrast to the PA are seen in the early postoperative period and hence are short-lived muscle weakness. However, there is no effect on VAS, HSS, and SF-36 scores. Therefore, the surgical approach is to be chosen according to the surgeon's expertise.

Lumbar spinal fusion does not increase early dislocation risk in primary total hip arthroplasty through the direct anterior approach

INTRODUCTION

Patients with total hip arthroplasty (THA) and a concomitant lumbar spinal fusion (LSF) might have an increased incidence of revision surgery and postoperative complications such as early THA dislocation. The direct anterior approach (DAA) has gained popularity in THA due to its soft tissue-preserving nature and the relatively low dislocation risk. The purpose of the present study was to examine whether LSF patients undergoing minimally invasive THA through the DAA might have an increased risk of prosthetic-related complications compared to matched-control patients without a LSF.

MATERIALS AND METHODS

Patients who underwent THA through the DAA in our institution from January 2014 to December 2018 were identified. A total of 30 primary THA also underwent LSF within 3 months from the initial operation. These patients were randomly matched (1:3) for sex, age, and body mass index with patients who underwent primary THA in our institution without a history of LSF (control group). Peri and postoperative complications, revisions, radiographic and clinical outcomes were assessed retrospectively.

RESULTS

LSF patients who underwent THA through the DAA did not have an increased risk of prosthetic-related complications compared to matched-control subjects without a LSF (6.6% versus 4.4%, P < 0.05). The functional and radiological outcomes were similar between groups.

CONCLUSION

LSF patients undergoing THA could benefit from the DAA similarly to patients without LSF and without increased rate of early THA dislocation. Although the complex interplay between the lumbar spine and hip in THA patients warrants further investigation, the outcomes of THA through the DAA in LSF patients appear promising.

LEVEL OF EVIDENCE

Retrospective case-control study, III.

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.

Gene correlation network analysis to identify regulatory factors in sciatic nerve injury

BACKGROUND

Sciatic nerve injury (SNI), which frequently occurs under the traumatic hip and hip fracture dislocation, induces serious complications such as motor and sensory loss, muscle atrophy, or even disabling. The present work aimed to determine the regulating factors and gene network related to the SNI pathology.

METHODS

Sciatic nerve injury dataset GSE18803 with 24 samples was divided into adult group and neonate group. Weighted gene co-expression network analysis (WGCNA) was carried out to identify modules associated with SNI in the two groups. Moreover, differentially expressed genes (DEGs) were determined from every group, separately. Subsequently, co-expression network and protein-protein interaction (PPI) network were overlapped to identify hub genes, while functional enrichment and Reactome analysis were used for a comprehensive analysis of potential pathways. GSE30165 was used as the test set for investigating the hub gene involvement within SNI. Gene set enrichment analysis (GSEA) was performed separately using difference between samples and gene expression level as phenotype label to further prove SNI-related signaling pathways. In addition, immune infiltration analysis was accomplished by CIBERSORT. Finally, Drug-Gene Interaction database (DGIdb) was employed for predicting the possible therapeutic agents.

RESULTS

14 SNI status modules and 97 DEGs were identified in adult group, while 15 modules and 21 DEGs in neonate group. A total of 12 hub genes was overlapping from co-expression and PPI network. After the results from both test and training sets were overlapped, we verified that the ten real hub genes showed remarkably up-regulation within SNI. According to functional enrichment of hub genes, the above genes participated in the immune effector process, inflammatory responses, the antigen processing and presentation, and the phagocytosis. GSEA also supported that gene sets with the highest significance were mostly related to the cytokine-cytokine receptor interaction. Analysis of hub genes possible related signaling pathways using gene expression level as phenotype label revealed an enrichment involved in Lysosome, Chemokine signaling pathway, and Neurotrophin signaling pathway. Immune infiltration analysis showed that Macrophages M2 and Regulatory T cells may participate in the development of SNI. At last, 25 drugs were screened from DGIdb to improve SNI treatment.

CONCLUSIONS

The gene expression network is determined in the present work based on the related regulating factors within SNI, which sheds more light on SNI pathology and offers the possible biomarkers and therapeutic targets in subsequent research.

Do Patients With Higher Preoperative Functional Outcome Scores Preferentially Seek Direct Anterior Approach Total Hip Arthroplasty?

Background

There is focus on the direct anterior approach (DAA) for total hip arthroplasty because of perceived postoperative functional improvement. We compared baseline, short-term, and long-term outcomes between the DAA and the posterior approach focusing on baseline function.

Material and methods

Multivariate linear and logistic regression models were used to analyze prospective data on 1457 total hip arthroplasties comparing baseline characteristics, operative time, 90-day reoperation, length of stay (LOS), extended LOS (>3 days), and facility discharge. The Patient-Reported Outcome Measurement Information System-Global Health (PROMIS-10) was used to determine physical component score (PCS) and mental component score (MCS), with clinically significant improvement defined as >5 points. Adjusters included age, sex, race/ethnicity, year, Charlson Comorbidity Index, body mass index, alcohol, and tobacco use.

Results

DAA patients had higher preoperative MCS (DAA 50.4 vs posterior approach 47.4, P < .001), PCS (40.7 vs 38.5, P < .001), and postoperative PCS scores (48.9 vs 46.7, P < .001). There was no difference in mean PCS improvement (8.1 vs 8.2; P = .798) or clinically significant PCS change (P = .963). DAA was associated with shorter LOS by 0.49 days (95% confidence interval [CI] = 0.32-0.65, P < .001), lower odds of extended LOS (odds ratio = 0.33, 95% CI = 0.21-0.50, P < .001), and lower odds of facility discharge (odds ratio = 0.54, 95% CI = 0.37-0.79, P < .001). No difference in operative time (86 vs 87 minutes; P = .812) or 90-day reoperations (1 vs 1%; P = .347) was observed.

Conclusion

DAA patients presented with higher preoperative PCS and MCS scores, yet both groups experienced significant improvement. DAA was associated with decreased LOS and lower odds of extended LOS and facility discharge. There was no difference in operative time or reoperation.

Sex-Specific Difference in Dynamic Balance Following Total Hip Replacement

Background and Objectives

Total hip arthroplasty (THA) is a common surgical procedure in older adults (65 years or older). THA has high patient satisfaction, but little is known about balance and mobility limitations after surgery and if outcomes are sex-specific. This study was aimed to evaluate post-THA asymmetry during unilateral standing and a dynamic balance and reach test and test the hypotheses that balance performance would be decreased on the surgical limb and that balance deficits would be greater in women than in men.

Research Design and Methods

Primary, unilateral THA (70 male, 57 female) patients completed a bilateral 10-s single-leg stance test. Sixty male but only 34 female participants could maintain unilateral balance for 10 s or greater. The cohort who successfully completed the 10-s single-limb stance test then completed a Lower Quarter Y-Balance Test in which the maximum anterior (ANT), posteromedial (PM), and posterolateral reach distances were obtained bilaterally and used to calculate the asymmetry score. All variables were compared using a mixed-model repeated-measures analysis of variance (sex by limb), while independent samples t tests were used to assess sex-specific asymmetry.

Results

Women failed single-leg stance at a higher rate than men (85.7% vs 59.6%; p = .001). Reach distance was different between limbs for all reach directions (p < .004) with greater reach distance on the nonoperative limb for all patients. Men had a greater reach distance in the ANT (p = .004) and PM (p = .006) directions.

Discussion and Implications

These results indicate that post-THA, the operative limb and female patients have greater balance limitations. These results are novel and reveal sex-specific patterns that emphasize the need for sex-specific postoperative rehabilitation programs to improve long-term outcomes, especially in older adults with muscle weakness and balance deficits.

Contemporary posterior surgical approach in total hip replacement: still more reoperations due to dislocation compared with direct lateral approach? An observational study of the Swedish Hip Arthroplasty Register including 156,979 hips

Background and purpose - The direct lateral approach (DLA) and the posterior approach (PA) are the most common surgical approaches in total hip replacement (THR) in Sweden. We investigated how the relationship between surgical approach and risk of reoperation due to dislocation has evolved over time. Patients and methods - Data were extracted from the Swedish Hip Arthroplasty Register from 1999 to 2014. We selected all THRs due to osteoarthritis with head sizes 28, 32, and 36 mm that were performed with either the DLA or the PA. Resurfacing prostheses were excluded. Kaplan-Meier curves for risk of reoperation due to dislocation and all-cause for the 2 surgical approaches were compared for 2 periods (1999-2006 and 2007-2014) up to 2 years postoperatively. We used Cox regression for sex, age, type of fixation, and head size to determine hazard ratios (HR) with DLA set as reference. Results - 156,979 THRs met the selection criteria. In 1999-2006, the PA was associated with increased risk of reoperation due to dislocation (HR 2.3, 95% CI 1.7-3.0) but there was no difference in the risk of all-cause reoperation (HR 1.1, CI 0.9-1.2). In 2007-2014 there was no statistically significant difference in the risk of reoperation due to dislocation (HR 1.2, CI 0.9-1.6) but the risk of all-cause reoperation was lower (HR 0.8, CI 0.7-0.9) for the PA. Interpretation - This study confirms historic reports on the increased risk of early reoperations due to dislocations using the PA compared with the DLA. However, in contemporary practice, the higher risk of reoperation due to dislocation associated with PA has declined, now being similar to that after DLA. We believe improved surgical technique for the PA may explain the results. Surprisingly, the PA was associated with lower risk of all-cause reoperation in 2007-2014. This finding warrants further investigation.

The design of the cemented stem influences the risk of Vancouver type B fractures, but not of type C: an analysis of 82,837 Lubinus SPII and Exeter Polished stems

Background and purpose - In total hip replacements, stem design may affect the occurrence of periprosthetic femoral fracture. We studied risk factors for fractures around and distal to the 2 most used cemented femoral stems in Sweden. Patients and methods - This is a register study including all standard primary Lubinus SPII and Exeter Polished stems operated in Sweden between 2001 and 2009. The outcome was any kind of reoperation due to fracture around (Vancouver type B) or distal to the stem (Vancouver type C), with use of age, sex, diagnosis at primary THR, and year of index operation as covariates in a Cox regression analysis. A separate analysis of the primary osteoarthritis patient group was done in order to evaluate eventual influence of the surgical approach (lateral versus posterior) on the risk for Vancouver type B fractures. Results - The Exeter stem had a 10-times (95% CI 7-13) higher risk for type B fractures, compared with the Lubinus, while no statistically significant difference was noticed for type C fractures. The elderly, and patients with hip fracture or idiopathic femoral head necrosis, had a higher risk for both fracture types. Inflammatory arthritis was a risk factor only for type C fractures. Type B fractures were more common in men, and type C in women. A lateral approach was associated with decreased risk for Type B fracture. Interpretation - Stem design influenced the risk for type B, but not for type C fracture. The influence of surgical approach on the risk for periprosthetic femoral fracture should be studied further.

Perioperative platelet rich plasma (PRP) in total hip arthroplasty through the Hardinge approach: protocol to study the effectiveness for gluteus medius healing

Background

Platelet-rich plasma (PRP) has been used to support tendon regeneration mainly in sports medicine. PRP is a concentrate of platelet-rich plasma proteins derived from whole blood by centrifugation to remove erythrocytes and leukocytes. PRP has high amounts of platelets which may promote healing tendons affected by degenerative conditions. These platelets contain growth factors and are known to facilitate the regeneration of injured tendon structures. Total hip arthroplasty (THA) through the Hardinge approach may leave the patient with impaired gait and poor regeneration of the gluteus medius tendon if the tendon is not reattached properly after closure of the surgical wound.

Methods

The study will be a multicenter, double-blinded and randomized study enrolling 90 patients based on power calculations. The efficacy of perioperative PRP treatment will be assessed by subjective and objective outcome variables. The participants will be randomized (sealed envelope) into either a placebo (saline) or a PRP group (1:1). For subjective outcomes, the Oxford Hip Score (OHS) will be collected before surgery and 3 and 12 months after surgery. The objective measures are findings at magnetic resonance imaging and plain radiographs and recorded values of measured strength.

Discussion

We present the perioperative use and the ways to measure the clinical efficacy of PRP. As PRP may have benefits regarding degenerative tendon regeneration, studies on the use of PRP in hip arthroplasty are warranted to facilitate postoperative recovery.

Trial registration

This study has been approved by the ethics committee of the Hospital District of Southwest Finland and approved by the local institutional research board. The study has been registered in ClinicalTrials.gov (NCT02607462).

Risk Factors for the Development of Nerve Palsy Following Primary Total Hip Arthroplasty

Background:

Nerve palsy following total hip arthroplasty (THA) is a complication that worsens the functional prognosis. The present study analyzed the risk factors of nerve palsy following THA.

Methods:

The subjects of this study included 6,123 cases in which primary THA was performed under spinal anesthesia with cementless implants used in the posterolateral approach.

Results:

Fourteen cases (0.22%) developed nerve palsy following THA, all of which involved palsy of the entire peroneal nerve region. The diagnoses included osteoarthritis due to subluxation (n=6), complete hip dislocation (n=3), osteonecrosis of the femoral head (n=2), primary osteoarthritis (n=1), osteoarthritis due to trauma (n=1), and multiple osteochondromatosis (n=1). Recovery from nerve palsy was confirmed in 10 cases; the longest recovery period was three years. A univariate analysis revealed significant differences in the osteoarthritis due to subluxation, osteonecrosis of the femoral head, complete hip dislocation, body weight and body mass index. However, none of the factors remained significant in multivariate analysis. Peroneal (ischiadic) nerve palsy following THA occurred in patients with osteonecrosis of the femoral head, complete hip dislocation, low body weight and a low body mass index. However, there were no cases of nerve palsy after the introduction of THA combined with shortening osteotomy of the femur for complete hip dislocation. patients.

Conclusion:

It is necessary to pay attention to direct pressure in cases of lower body weight and lower BMI because compression of the sciatic nerve during surgery and compression of the fibular head are considered to be risk factors.

Radiographic cup position following posterior and lateral approach to total hip arthroplasty. An explorative randomized controlled trial

The two most common surgical approaches to total hip arthroplasty are the posterior approach and lateral approach. The surgical approach may influence cup positioning and restoration of the offset, which may affect the biomechanical properties of the hip joint.

The primary aim was to compare cup position between posterior approach and lateral approach. Secondary aims were to compare femoral offset, abductor moment arm and leg length discrepancy between the two approaches. Eighty patients with primary hip osteoarthritis were included in a randomized controlled trial and assigned to total hip arthroplasty using posterior approach or lateral approach. Postoperative radiographs from 38 patients in each group were included in this study for measurement of cup anteversion and inclination. Femoral offset, cup offset, total offset, abductor moment arm and leg length discrepancy were measured on preoperative and postoperative radiographs in 28 patients in each group. We found that mean anteversion was 5° larger in the posterior approach group (95% CI, -8.1 to -1.4; p = 0.006), while mean inclination was 5° less steep (95% CI, 2.7 to 7.2; p<0.001) compared with the lateral approach group. The posterior approach group had a larger mean femoral offset of 4.3mm (95% CI, -7.4 to -1.3, p = 0.006), mean total offset of 6.3mm (95% CI, -9.6 to -3; p<0.001) and mean abductor moment arm of 4.8mm (95% CI, -7.6 to -1.9; p = 0.001) compared with the lateral approach group. We found a larger cup anteversion but less steep cup inclination in the posterior approach group compared with the lateral approach group. Femoral offset and abductor moment arm were restored after total hip arthroplasty using lateral approach but significantly increased when using posterior approach.

Comparison of outcome measures and complication rates following three different approaches for primary total hip arthroplasty: a pragmatic randomised controlled trial

BACKGROUND

Total hip arthroplasty is one of the most commonly performed surgical procedures worldwide. There are a number of surgical approaches for total hip arthroplasty and no high-level evidence supporting one approach over the other. Each approach has its unique benefits and drawbacks. This trial aims to directly compare the three most common surgical approaches for total hip arthroplasty.

METHODS/DESIGN

This is a single-centre study conducted at Western Health, Melbourne, Australia; a large metropolitan centre. It is a pragmatic, parallel three-arm, randomised controlled trial. Sample size will be 243 participants (81 in each group). Randomisation will be secure, web-based and managed by an independent statistician. Patients and research team will be blinded pre-operatively, but not post-operatively. Intervention will be either direct anterior, lateral or posterior approach for total hip arthroplasty, and the three arms will be directly compared. Participants will be aged over 18 years, able to provide informed consent and recruited from our outpatients. Patients who are having revision surgery or have indications for hip replacement other than osteoarthritis (i.e., fracture, malignancy, development dysplasia) will be excluded from the trial. The Oxford Hip Score will be determined for patients pre-operatively and 6 weeks, 6, 12 and 24 months post-operatively. The Oxford Hip Score at 24 months will be the primary outcome measure. Secondary outcome measures will be dislocation, infection, intraoperative and peri-prosthetic fracture rate, length of hospital stay and pain level, reported using a visual analogue scale.

DISCUSSION

Many studies have evaluated approaches for total hip arthroplasty and arthroplasty registries worldwide are now collecting this data. However no study to date has compared these three common approaches directly in a randomised fashion. No trial has used patient-reported outcome measures to evaluate success. This pragmatic study aims to identify differences in patient perception of total hip arthroplasty depending on surgical approach.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12617000272392 . Registered on 22 February 2017.

A comparison of the omega and posterior approaches on patient reported function and radiological outcomes following total hip replacement

BACKGROUND

The omega approach represents a modification of the lateral approach to the hip for joint replacement. It was developed to reduce the potential for gluteus muscle dysfunction and thereby improve functional outcome following hip replacement.

METHODS

A cohort of 415 consecutive hip replacements receiving the same type of cemented femoral component were followed up at a mean of three years postoperatively and invited to complete functional outcome and satisfaction scores.

RESULTS

There were no differences between the omega and the posterior approach in terms of post-operative Oxford Hip Score, Short Form-12 score, patient satisfaction and a range of radiographic parameters.

CONCLUSIONS

The omega approach appears to perform equally to the posterior approach in this cohort of patients.

A SIX-WEEK SUPERVISED EXERCISE AND EDUCATIONAL INTERVENTION AFTER TOTAL HIP ARTHROPLASTY: A CASE SERIES

BACKGROUND AND PURPOSE

Most rehabilitation interventions after total hip arthroplasty (THA) are not designed to return patients to high-levels of physical activity and, thus, low levels of physical activity and residual weakness are common. The purpose of this case series was to describe the feasibility and preliminary efficacy of an exercise and education intervention for patients after THA who have already completed formal outpatient physical therapy.

STUDY DESIGN

Case series.

CASE DESCRIPTION

Two participants underwent unilateral THA seven (case A) or eight (case B) months prior to the intervention. Individuals participated in 18 treatment sessions that included progressive aerobic and strengthening exercises and meetings with a health coach. Change in function, strength, and self-reported physical activity were measured. Outcomes 12 months after surgery were compared to a historical cohort of patients after THA.

OUTCOME

There were no adverse events during the intervention. At the end of the intervention, hip and knee strength on the surgical side increased approximately 30% compared to baseline in both cases. Activity level, and recreational performance, including walking up stairs and hiking uphill (case A), and running and golfing (case B), improved by the end of the intervention. Most changes were maintained at follow-up, although hip strength for case B decreased 27% after discharge from the intervention. Outcomes for both cases exceeded historical averages for patients 12 months after THA, with the exception of strength in case B.

DISCUSSION

The exercise intervention was well tolerated and without negative effects in two participants. Both participants increased their ability to complete demanding recreational and sports-related activities, physical activity, and demonstrated improved hip abductor and knee extensor strength. Further research is needed to evaluate the implementation and effectiveness of similar interventions after THA.

LEVEL OF EVIDENCE

Level 4.

The efficacy of modified direct lateral versus posterior approach on gait function and hip muscle strength after primary total hip arthroplasty at 12months follow-up. An explorative randomised controlled trial

BACKGROUND

The lateral and the posterior approach are the most commonly used procedures for total hip arthroplasty. Due to the detachment of the hip abductors, lateral approach is claimed to cause reduced hip muscle strength and altered gait pattern. However, this has not been investigated in a randomised controlled trial. The aim was to compare the efficacy of total hip arthroplasty performed by lateral or posterior approach on gait function and hip muscle strength up to 12months post-operatively. We hypothesised that posterior approach would be superior to lateral approach.

METHODS

Forty-seven patients with primary hip osteoarthritis were randomised to total hip arthroplasty with either posterior or lateral approach and evaluated pre-operatively, 3 and 12months post-operatively using 3-dimensional gait analyses as objective measures of gait function, including Gait Deviation Index, temporo-spatial parameters and range of motion. Isometric maximal hip muscle strength in abduction, flexion and extension was also tested.

FINDINGS

Post-operatively, no between-group difference in gait function was observed. However, both hip abductor and flexor muscle strength improved more in the posterior approach group: -0.20(Nm/kg)[95%CI:-0.4 to 0.0] and -0.20(Nm/kg)[95%CI:-0.4 to 0.0], respectively.

INTERPRETATION

Contrary to our first hypothesis, the overall gait function in the posterior approach group did not improve more than in the lateral approach group. However, in agreement with our second hypothesis, patients in the posterior approach group improved more in hip abductor and flexor muscle strength at 12months. Further investigation of the effect of reduced maximal hip muscle strength on functional capacity is needed. ClinicalTrials.gov. No.: NCT01616667.

Improving patients’ experience and outcome of total joint replacement: the RESTORE programme

Background

Total hip replacements (THRs) and total knee replacements (TKRs) are common elective procedures. In the REsearch STudies into the ORthopaedic Experience (RESTORE) programme, we explored the care and experiences of patients with osteoarthritis after being listed for THR and TKR up to the time when an optimal outcome should be expected.

Objective

To undertake a programme of research studies to work towards improving patient outcomes after THR and TKR.

Methods

We used methodologies appropriate to research questions: systematic reviews, qualitative studies, randomised controlled trials (RCTs), feasibility studies, cohort studies and a survey. Research was supported by patient and public involvement.

Results

Systematic review of longitudinal studies showed that moderate to severe long-term pain affects about 7–23% of patients after THR and 10–34% after TKR. In our cohort study, 10% of patients with hip replacement and 30% with knee replacement showed no clinically or statistically significant functional improvement. In our review of pain assessment few research studies used measures to capture the incidence, character and impact of long-term pain. Qualitative studies highlighted the importance of support by health and social professionals for patients at different stages of the joint replacement pathway. Our review of longitudinal studies suggested that patients with poorer psychological health, physical function or pain before surgery had poorer long-term outcomes and may benefit from pre-surgical interventions. However, uptake of a pre-operative pain management intervention was low. Although evidence relating to patient outcomes was limited, comorbidities are common and may lead to an increased risk of adverse events, suggesting the possible value of optimising pre-operative management. The evidence base on clinical effectiveness of pre-surgical interventions, occupational therapy and physiotherapy-based rehabilitation relied on small RCTs but suggested short-term benefit. Our feasibility studies showed that definitive trials of occupational therapy before surgery and post-discharge group-based physiotherapy exercise are feasible and acceptable to patients. Randomised trial results and systematic review suggest that patients with THR should receive local anaesthetic infiltration for the management of long-term pain, but in patients receiving TKR it may not provide additional benefit to femoral nerve block. From a NHS and Personal Social Services perspective, local anaesthetic infiltration was a cost-effective treatment in primary THR. In qualitative interviews, patients and health-care professionals recognised the importance of participating in the RCTs. To support future interventions and their evaluation, we conducted a study comparing outcome measures and analysed the RCTs as cohort studies. Analyses highlighted the importance of different methods in treating and assessing hip and knee osteoarthritis. There was an inverse association between radiographic severity of osteoarthritis and pain and function in patients waiting for TKR but no association in THR. Different pain characteristics predicted long-term pain in THR and TKR. Outcomes after joint replacement should be assessed with a patient-reported outcome and a functional test.

Conclusions

The RESTORE programme provides important information to guide the development of interventions to improve long-term outcomes for patients with osteoarthritis receiving THR and TKR. Issues relating to their evaluation and the assessment of patient outcomes are highlighted. Potential interventions at key times in the patient pathway were identified and deserve further study, ultimately in the context of a complex intervention.

Study registration

Current Controlled Trials ISRCTN52305381.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 12. See the NIHR Journals Library website for further project information.

Does Surgical Approach Affect Patient-reported Function After Primary THA?

BACKGROUND

Total hip arthroplasty (THA) relieves pain and improves physical function in patients with hip osteoarthritis, but requires a year or more for full postoperative recovery. Proponents of intermuscular surgical approaches believe that the direct-anterior approach may restore physical function more quickly than transgluteal approaches, perhaps because of diminished muscle trauma. To evaluate this, we compared patient-reported physical function and other outcome metrics during the first year after surgery between groups of patients who underwent primary THA either through the direct-anterior approach or posterior approach.

QUESTIONS/PURPOSES

We asked: (1) Is a primary THA using a direct-anterior approach associated with better patient-reported physical function at early postoperative times (1 and 3 months) compared with a THA performed through the posterior approach? (2) Is the direct-anterior approach THA associated with shorter operative times and higher rates of noninstitutional discharge than a posterior approach THA?

METHODS

Between October 2008 and February 2010, an arthroplasty fellowship-trained surgeon performed 135 THAs. All 135 were performed using the posterior approach. During that period, we used this approach when patients had any moderate to severe degenerative joint disease of the hip attributable to any type of arthritis refractory to nonoperative treatment measures. Of the patients who were treated with this approach, 21 (17%; 23 hips) were lost to followup, whereas 109 (83%; 112 hips) were available for followup at 1 year. Between February and September 2011, the same surgeon performed 86 THAs. All 86 were performed using the direct-anterior approach. During that period, we used this approach when patients with all types of moderate to severe degenerative joint disease had nonoperative treatment measures fail. Of the patients who were treated with this approach, 35 (41%; 35 hips) were lost to followup, whereas 51 (59%; 51 hips) were available for followup at 1 year. THAs during the surgeon's direct-anterior approach learning period (February 2010 through January 2011) were excluded because both approaches were being used selectively depending on patient characteristics. Clinical outcomes included operative blood loss; allogeneic transfusion; adverse events; patient-reported Veterans RAND-12 Physical (PCS) and Mental Component Summary (MCS) scores, and University of California Los Angeles (UCLA) activity scores at 1 month, 3 months, and 1 year after surgery. Resource utilization outcomes included operative time, length of stay, and discharge disposition (home versus institution). Outcomes were compared using logistic and linear regression techniques.

RESULTS

After controlling for relevant confounding variables including age, sex, and BMI, the direct-anterior approach was associated with worse adjusted MCS changes 1 and 3 months after surgery (1-month score change, -9; 95% CI, -13 to -5; standard error, 2), compared with the posterior approach (3-month score change, -9; 95% CI, -14 to -3; standard error, 3) (both p < 0.001), while the direct-anterior approach was associated with greater PCS improvement at 3 months compared with the posterior approach (score change, 6; 95% CI, 2-10; standard error, 2; p = 0.008). There were no differences in adjusted PCS at either 1 month or 12 months, and no clinically important differences in UCLA scores. Although the PCS score differences are greater than the minimum clinically important difference of 5 points for this endpoint, the clinical importance of such a small effect is questionable. At 1 year after THA, there were no intergroup differences in self-reported physical function, although both groups had significant loss-to-followup at that time. Operative time (skin incision to skin closure) between the two groups did not differ (81 versus 79 minutes; p = 0.411). Mean surgical blood loss (403 versus 293 mL; p < 0.001; adjusted, 119 more mL; 95% CI, 79-160; p < 0.001) and in-hospital transfusion rates (direct-anterior approach, 20% [17/86] versus posterior approach, 10% [14/135], p = 0.050; adjusted odds ratio, 3.6; 95% CI, 1.3-10.1; p = 0.016) were higher in the direct-anterior approach group. With the numbers available, there was no difference in the frequency of adverse events between groups when comparing intraoperative complications, perioperative Technical Expert Panel complications, and other non-Technical Expert Panel complications within 1 year of surgery, although this study was not adequately powered to detect differences in rare adverse events.

CONCLUSIONS

With suitable experience, the direct-anterior approach can be performed with expected results similar to those of the posterior approach. There may be transient and small benefits to the direct-anterior approach, including improved physical function at 3 months after surgery. However, the greater operative blood loss and greater likelihood of blood transfusions, even when the surgeon is experienced, may be a disadvantage. Given some of the kinds of bias present that we found, including loss to followup, the conclusions we present should be considered preliminary, but it appears that any benefits that accrue to the patients who had the direct-anterior approach would be transient and modest. Prospective randomized studies on the topic are needed to address the differences between surgical approaches more definitively.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Preoperative factors associated with postoperative gait kinematics and kinetics after total hip arthroplasty

OBJECTIVE

To determine how patient factors: age, sex, body mass index (BMI), clinical scores and physical exam findings, are associated with gait recovery after total hip arthroplasty (THA).

METHOD

145 subjects, who were evaluated with standard gait analysis, the Harris Hip Score (HHS), and a physical exam including passive range of motion (ROM), hip abductor strength assessment, before and after primary unilateral THA, were identified from an IRB-approved repository. Sagittal plane dynamic ROM and 3D peak external moments were averaged from operated-side normal-speed trials at each visit. We used linear regression analysis to evaluate the association among preoperative clinical factors and postoperative gait, with and without controlling for the influence of preoperative gait variables.

RESULTS

Sagittal and transverse plane moments, and the peak abduction moment seen in early stance, significantly improved after THA (p < 0.001, effect size d = 0.22-1.04). The peak adduction moment did not change significantly (p = 0.646), although the change ranged from -2.7 to + 4.0 %Body weight × height (-80% to +315%). Preoperative gait, clinical factors and patient characteristics predicted up to 33% of the variability in postoperative gait. Notably, greater preoperative abductor strength was associated with higher postoperative adduction and external rotation moments (R = 0.197-0.266, p < 0.05) after adjusting for age, sex, BMI and preoperative gait.

CONCLUSION

Preoperative clinical factors predicted several specific aspects of objectively-characterized postoperative gait function. Physical exam findings can augment the predictive ability of clinical outcome measures, and potentially help guide rehabilitation plans.

Surgical approach in primary total hip arthroplasty: anatomy, technique and clinical outcomes

Total hip arthroplasty (THA) has revolutionized the treatment of hip arthritis. A number of surgical approaches to the hip joint exist, each with unique advantages and disadvantages. The most commonly used approaches include the direct anterior, direct lateral and posterior approaches. A number of technical intricacies allow safe and efficient femoral and acetabular reconstruction when using each approach. Hip dislocation, abductor insufficiency, fracture and nerve injury are complications of THA, although their relative risk varies by approach. Numerous clinical trials have sought to elicit differences in patient-reported outcomes, complication rates and return to function among the surgical approaches. This review outlines some of the technical pearls of performing a THA through either a direct anterior, direct lateral or posterior approach. A literature review outlines the impact of surgical approach on clinical outcomes and clinically relevant complication rates.

A systematic review and meta-analysis of complications following the posterior and lateral surgical approaches to total hip arthroplasty

INTRODUCTION

Total hip arthroplasty is one of the most commonly performed orthopaedic procedures. Despite this, medical evidence to inform the choice of surgical approach is lacking. Currently in the UK, the two most frequently performed approaches to the hip are the posterior and the direct lateral.

METHODS

This systematic review was performed according to Cochrane guidelines following an extensive search for prospective controlled trials published in any language before January 2014. Of the 728 records identified from searches, 6 prospective studies (including 3 randomised controlled trials) involving 517 participants provided data towards this review.

FINDINGS

Compared with the lateral approach, the posterior approach conferred a significant reduction in the risk of Trendelenburg gait (odds ratio [OR]: 0.31, p=0.0002) and stem malposition (OR: 0.24, p=0.02), and a non-significant reduction in dislocation (OR: 0.37, p=0.16) and heterotopic ossification (OR: 0.41, p=0.13). Neither approach conferred a functional advantage. We draw attention to the paucity of evidence and the need for a further randomised trial.

Worse patient-reported outcome after lateral approach than after anterior and posterolateral approach in primary hip arthroplasty. A cross-sectional questionnaire study of 1,476 patients 1-3 years after surgery

BACKGROUND

The surgical approach in total hip arthroplasty (THA) is often based on surgeon preference and local traditions. The anterior muscle-sparing approach has recently gained popularity in Europe. We tested the hypothesis that patient satisfaction, pain, function, and health-related quality of life (HRQoL) after THA is not related to the surgical approach.

PATIENTS

1,476 patients identified through the Norwegian Arthroplasty Register were sent questionnaires 1-3 years after undergoing THA in the period from January 2008 to June 2010. Patient-reported outcome measures (PROMs) included the hip disability osteoarthritis outcome score (HOOS), the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), health-related quality of life (EQ-5D-3L), visual analog scales (VAS) addressing pain and satisfaction, and questions about complications. 1,273 patients completed the questionnaires and were included in the analysis.

RESULTS

Adjusted HOOS scores for pain, other symptoms, activities of daily living (ADL), sport/recreation, and quality of life were significantly worse (p < 0.001 to p = 0.03) for the lateral approach than for the anterior approach and the posterolateral approach (mean differences: 3.2-5.0). These results were related to more patient-reported limping with the lateral approach than with the anterior and posterolateral approaches (25% vs. 12% and 13%, respectively; p < 0.001).

INTERPRETATION

Patients operated with the lateral approach reported worse outcomes 1-3 years after THA surgery. Self-reported limping occurred twice as often in patients who underwent THA with a lateral approach than in those who underwent THA with an anterior or posterolateral approach. There were no significant differences in patient-reported outcomes after THA between those who underwent THA with a posterolateral approach and those who underwent THA with an anterior approach.

Patient-reported outcome is influenced by surgical approach in total hip replacement

The effects of surgical approach in total hip replacement on health-related quality of life and long-term pain and satisfaction are unknown. From the Swedish Hip Arthroplasty Register, we extracted data on all patients that had received a total hip replacement for osteoarthritis through either the posterior or the direct lateral approach, with complete pre- and one-year post-operative Patient Reported Outcome Measures (PROMs). A total of 42 233 patients met the inclusion criteria and of these 4962 also had complete six-year PROM data. The posterior approach resulted in an increased mean satisfaction score of 15 (sd 19) vs 18 (sd 22) (p <  0.001) compared with the direct lateral approach. The mean pain score was 13 (sd 17) vs 15 (sd 19) (p < 0.001) and the proportion of patients with no or minimal pain was 78% vs 74% (p < 0.001) favouring the posterior approach. The patients in the posterior approach group reported a superior mean EQ-5D index of 0.79 (sd 0.23) vs 0.77 (sd 0.24) (p < 0.001) and mean EQ score of 76 (sd 20) vs 75 (sd 20) (p < 0.001). All observed differences between the groups persisted after six years follow-up. Although PROMs after THR in general are very good regardless of surgical approach, the results indicate that some patients operated by the direct lateral approach report an inferior outcome compared with the posterior approach. The large number of procedures and the seemingly sustained differences make it likely these findings are clinically relevant.

Cite this article: Bone Joint J 2014;96-B:590–6.

Classification and surgical approaches to hip fractures for nonsurgeons

The location and type of hip fracture, and the patient's activity level, help to determine the method of surgical repair. Nondisplaced femoral neck fractures are treated with screw fixation. Displaced fractures are treated with arthroplasty. If the patient is very active, the treatment of choice should be total hip replacement, whereas if the patient is less active, the treatment of choice is hemiarthroplasty. Intertrochanteric fractures are classified as stable (treated with a sliding hip screw) or unstable (treated with an intramedullary hip screw). Subtrochanteric fractures are classified as typical or atypical. All subtrochanteric fractures are treated with intramedullary hip screws.

An extended posterior approach to the hip and pelvis for complex acetabular reconstruction that preserves the gluteal muscles and their neurovascular supply

We investigated the detailed anatomy of the gluteus maximus, gluteus medius and gluteus minimus and their neurovascular supply in 22 hips in 11 embalmed adult Caucasian human cadavers. This led to the development of a surgical technique for an extended posterior approach to the hip and pelvis that exposes the supra-acetabular ilium and preserves the glutei during revision hip surgery. Proximal to distal mobilisation of the gluteus medius from the posterior gluteal line permits exposure and mobilisation of the superior gluteal neurovascular bundle between the sciatic notch and the entrance to the gluteus medius, enabling a wider exposure of the supra-acetabular ilium. This technique was subsequently used in nine patients undergoing revision total hip replacement involving the reconstruction of nine Paprosky 3B acetabular defects, five of which had pelvic discontinuity. Intra-operative electromyography showed that the innervation of the gluteal muscles was not affected by surgery. Clinical follow-up demonstrated good hip abduction function in all patients. These results were compared with those of a matched cohort treated through a Kocher-Langenbeck approach. Our modified approach maximises the exposure of the ilium above the sciatic notch while protecting the gluteal muscles and their neurovascular bundle.

Posterior approach and uncemented stems increases the risk of reoperation after hemiarthroplasties in elderly hip fracture patients

BACKGROUND

Hemiarthroplasties are performed in great numbers worldwide but are seldom registered on a national basis. Our aim was to identify risk factors for reoperation after fracture-related hemiarthroplasty in Norway and Sweden.

MATERIAL AND METHODS

A common dataset was created based on the Norwegian Hip Fracture Register and the Swedish Hip Arthroplasty Register. 33,205 hip fractures in individuals > 60 years of age treated with modular hemiarthroplasties were reported for the period 2005-2010. Cox regression analyses based on reoperations were performed (covariates: age group, sex, type of stem and implant head, surgical approach, and hospital volume).

RESULTS

1,164 patients (3.5%) were reoperated during a mean follow-up of 2.7 (SD 1.7) years. In patients over 85 years, an increased risk of reoperation was found for uncemented stems (HR = 2.2, 95% CI: 1.7-2.8), bipolar heads (HR = 1.4, CI: 1.2-1.8), posterior approach (HR = 1.4, CI: 1.2-1.8) and male sex (HR = 1.3, CI: 1.0-1.6). For patients aged 75-85 years, uncemented stems (HR = 1.6, 95% CI: 1.2-2.0) and men (HR = 1.3, CI: 1.1-1.6) carried an increased risk. Increased risk of reoperation due to infection was found for patients aged < 75 years (HR = 1.5, CI: 1.1-2.0) and for uncemented stems. For open surgery due to dislocation, the strongest risk factor was a posterior approach (HR = 2.2, CI: 1.8-2.6). Uncemented stems in particular (HR = 3.6, CI: 2.4-5.3) and male sex increased the risk of periprosthetic fracture surgery.

INTERPRETATION

Cemented stems and a direct lateral transgluteal approach reduced the risk of reoperation after hip fractures treated with hemiarthroplasty in patients over 75 years. Men and younger patients had a higher risk of reoperation. For the age group 60-74 years, there were no such differences in risk in this material.

Primary total hip arthroplasty: health related quality of life outcomes

PURPOSE

The health related quality of life (HRQoL) outcomes of total hip arthroplasty (THA) present a pertinent and clinically important problem in modern orthopaedics. Our goal was to report and compare the health-related outcomes after THA in respect to type of fixation in patients with hip osteoarthritis (H-OA) one year after operation.

METHODS

A total of 145 patients with H-OA who received THA were evaluated. Uncemented and cemented subjects were evaluated using generic measures, i.e. the EQ-5D questionnaire, and the disease-specific measures designed by the authors, i.e. the Total Hip Arthroplasty Questionnaire (THAQ). Obtained data was statistically processed at the level of pain, functionality and general health perception. Patient-reported outcomes were measured differences between pre-operative measures and those at one-year follow-up visit.

RESULTS

Significant improvement in health outcomes was reached in both groups regardless of the type of fixation (p < 0.001). Uncemented fixation exhibited better results for EQ-5DINDEX, pain (p = 0.004) and self-care on EQ-5D (p = 0.043), as well as increased magnitude of change for functionality on THAQ (p = 0.002). However, additional analysis of the subset did not reveal a significant difference between cemented vs. uncemented groups with regard to function on THAQ, but the significant difference on self-care and pain dimensions of EQ-5D remained.

CONCLUSIONS

Uncemented endoprosthesis generally achieved better short-term outcomes in some dimensions. However, painless mobility has been restored in most of the patients, regardless of the fixation type. Both methods reached good clinical outcomes in their respective domains; therefore, we would emphasise prevention of osteoarthritis and the quality of care as the more important predictors of good clinical outcomes.

90-day mortality after 409,096 total hip replacements for osteoarthritis, from the National Joint Registry for England and Wales: a retrospective analysis

BACKGROUND

Death within 90 days after total hip replacement is rare but might be avoidable dependent on patient and treatment factors. We assessed whether a secular decrease in death caused by hip replacement has occurred in England and Wales and whether modifiable perioperative factors exist that could reduce deaths.

METHODS

We took data about hip replacements done in England and Wales between April, 2003, and December, 2011, from the National Joint Registry for England and Wales. Patient identifiers were used to link these data to the national mortality database and the Hospital Episode Statistics database to obtain details of death, sociodemographics, and comorbidity. We assessed mortality within 90 days of operation by Kaplan-Meier analysis and assessed the role of patient and treatment factors by Cox proportional hazards model.

FINDINGS

409,096 primary hip replacements were done to treat osteoarthritis. 1743 patients died within 90 days of surgery during 8 years, with a substantial secular decrease in mortality, from 0·56% in 2003 to 0·29% in 2011, even after adjustment for age, sex, and comorbidity. Several modifiable clinical factors were associated with decreased mortality according to an adjusted model: posterior surgical approach (hazard ratio [HR] 0·82, 95% CI 0·73-0·92; p=0·001), mechanical thromboprophylaxis (0·85, 0·74-0·99; p=0·036), chemical thromboprophylaxis with heparin with or without aspirin (0·79, 0·66-0·93; p=0·005), and spinal versus general anaesthetic (0·85, 0·74-0·97; p=0·019). Type of prosthesis was unrelated to mortality. Being overweight was associated with lower mortality (0·76, 0·62-0·92; p=0·006).

INTERPRETATION

Postoperative mortality after hip joint replacement has fallen substantially. Widespread adoption of four simple clinical management strategies (posterior surgical approach, mechanical and chemical prophylaxis, and spinal anaesthesia) could, if causally related, reduce mortality further.

FUNDING

National Joint Registry for England and Wales.

MAASH Technique for Total Hip Arthroplasty: A Capsular Work

BACKGROUND

Dislocation and leg length discrepancy are major complications following total hip arthroplasty (THA). Many surgical approaches for THA have been described, but none suggest a capsular incision that assures good exposure while maintaining adequate capsule integrity in closure.

PURPOSES

Modified anterolateral approach for stable hip (MAASH) is a modification of the classical Hardinge approach, but specifically preserves the anterior iliofemoral lateral ligament and pubofemoral ligament excising the "weak area" of the capsule, in the so called "internervous safe zone" and introducing the "box concept" for the anterior approach to the hip. This is the main difference of the MAASH approach. This technique can be used as a standard for all THA standard models, but we introduce new devices to make it easier.

METHODS

From November 2007 to May 2012, data were collected for this observational retrospective consecutive case study. We report the results of 100 THA cases corresponding to the development curve of this new concept in THA technique.

RESULTS

MAASH technique offers to hip surgeons, a reliable and reproducible THA anterolateral technique assuring accurate reconstruction of leg length and a low rate of dislocation. Only one dislocation and six major complications are reported, but most of them occurred at the early stages of technique development.

CONCLUSION

MAASH technique proposes a novel concept on working with the anterior capsule of the hip for the anterolateral approach in total hip arthroplasty, as well as for hemiarthroplasty in the elderly population with high dislocation risk factors. MAASH offers maximal stability and the ability to restore leg length accurately.

Differences in gait characteristics between total hip, knee, and ankle arthroplasty patients: a six-month postoperative comparison

Background

The recovery of gait ability is one of the primary goals for patients following total arthroplasty of lower-limb joints. The aim of this study was to objectively compare gait differences of patients after unilateral total hip arthroplasty (THA), total knee arthroplasty (TKA) and total ankle arthroplasty (TAA) with a group of healthy controls.

Methods

A total of 26 TAA, 26 TKA and 26 THA patients with a mean (± SD) age of 64 (± 9) years were evaluated six months after surgery and compared with 26 matched healthy controls. Subjects were asked to walk at self-selected normal and fast speeds on a validated pressure mat. The following spatiotemporal gait parameters were measured: walking velocity, cadence, single-limb support (SLS) time, double-limb support (DLS) time, stance time, step length and step width.

Results

TAA and TKA patients walked slower than controls at normal (p<0.05) and fast speeds (p<0.01). The involved side of TAA and TKA patients showed shorter SLS compared to controls at both normal and fast speeds (p<0.01). Regardless of walking speed, the uninvolved side of TAA and TKA patients demonstrated longer stance time and shorter step length than controls (p<0.01). TAA patients showed shorter SLS of the involved side, longer stance time and shorter step length of the uninvolved side compared to the contralateral side at both normal and fast speeds (p<0.001).

Conclusions

Gait disability after unilateral lower-limb joint arthroplasty was more marked for distal than for proximal joints at six months after surgery, with a proximal-to-distal progression in the impairment (TAA>TKA>THA). THA patients demonstrated no gait differences compared with controls. In contrast, TAA and TKA patients still demonstrated gait differences compared to controls, with slower walking velocity and reduced SLS in the involved limb. In addition, TAA patients presented marked side-to-side asymmetries in gait characteristics.

Case report: Painless chronic liner dissociation of a total hip arthroplasty

BACKGROUND

Dislocation or liner dissociation of a total hip prosthesis usually results in pain and discomfort. Although several reports describe chronic dislocation and its treatment, chronic liner dissociation is an unreported complication.

CASE DESCRIPTION

We report an unrecognized dissociation and displacement of the liner of a total hip prosthesis after revision THA. The patient had virtually no pain or functional restrictions. The patient's only complaint was pain on the contralateral side, associated with a leg-length discrepancy. Since the patient had no complaints relative to the liner dissociation we elected not to pursue further treatment. The contralateral pain was treated successfully with a shoe lift.

LITERATURE REVIEW

Chronic dislocation of a THA is a rare complication and we found reports of only seven cases in the literature. We found no reports of chronic liner dissociation.

CLINICAL RELEVANCE

Orthopaedic surgeons should be aware of the possibility of this rare complication. Our case and the literature suggest treatment can be nonsurgical or surgical.

The type of surgical approach influences the risk of revision in total hip arthroplasty: a study from the Swedish Hip Arthroplasty Register of 90,662 total hipreplacements with 3 different cemented prostheses

BACKGROUND AND PURPOSE

The most common surgical approaches in total hip arthroplasty in Sweden are the posterior and the anterolateral transgluteal approach. Currently, however, there is insufficient evidence to prefer one over the other regarding risk of subsequent surgery.

PATIENTS AND METHODS

We searched the Swedish Hip Arthroplasty Register between the years 1992 and 2009 to compare the posterior and anterolateral transgluteal approach regarding risk of revision in the 3 most common all-cemented hip prosthesis designs in Sweden. 90,662 total hip replacements met the inclusion criteria. We used Cox regression analysis for estimation of prosthesis survival and relative risk of revision due to dislocation, infection, or aseptic loosening.

RESULTS

Our results show that for the Lubinus SPII prosthesis and the Spectron EF Primary prosthesis, the anterolateral transgluteal approach gave an increased risk of revision due to aseptic loosening (relative risk (RR) = 1.3, 95% CI: 1.0-1.6 and RR = 1.6, CI: 1.0-2.5) but a reduced risk of revision due to dislocation (RR = 0.7, CI: 0.5-0.8 and RR = 0.3, CI: 0.1-0.4). For the Exeter Polished prosthesis, the surgical approach did not affect the outcome for dislocation or aseptic loosening. The surgical approach had no influence on the risk of revision due to infection in any of these designs.

INTERPRETATION

This observational study shows that the surgical approach affected the risk of revision due to aseptic loosening and dislocation for 2 of the most commonly used cemented implants in Sweden. Further studies are needed to determine whether these results are generalizable to other implants and to uncemented fixation.

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

BACKGROUND

Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention.

METHODS

Using a collection of reviews identified previously, 166 references including a meta-analysis were selected for review. At least one of the primary outcomes in each review was an adverse or unintended event. The nature of the intervention, source of funding, number of individual meta-analyses performed, number of primary studies included in the review, and use of meta-analytic methods were all recorded. Specific areas of interest relating to the methods used included the choice of outcome metric, methods of dealing with sparse events, heterogeneity, publication bias and use of individual patient data.

RESULTS

The 166 included reviews were published between 1994 and 2006. Interventions included drugs and surgery among other interventions. Many of the references being reviewed included multiple meta-analyses with 44.6% (74/166) including more than ten. Randomised trials only were included in 42.2% of meta-analyses (70/166), observational studies only in 33.7% (56/166) and a mix of observational studies and trials in 15.7% (26/166). Sparse data, in the form of zero events in one or both arms where the outcome was a count of events, was found in 64 reviews of two-arm studies, of which 41 (64.1%) had zero events in both arms.

CONCLUSIONS

Meta-analyses of adverse events data are common and useful in terms of increasing the power to detect an association with an intervention, especially when the events are infrequent. However, with regard to existing meta-analyses, a wide variety of different methods have been employed, often with no evident rationale for using a particular approach. More specifically, the approach to dealing with zero events varies, and guidelines on this issue would be desirable.

Bilateral femoral neck fractures resulting from a grand mal seizure in an elderly man with Down syndrome

Simultaneous bilateral hip fractures are exceedingly rare and usually occur following a seizure. To our knowledge, only 22 cases of such injuries have been reported in the literature during the past forty years and the majority of fractures are treated with open reduction and internal fixation. We present a case of a 66-year old man with Down syndrome and severe dementia who was diagnosed with bilateral displaced femoral neck fractures following an epileptic seizure. He was treated with single staged bilateral uncemented monopolar hemi-arthroplasties through lateral Hardinge approaches. The treatment choice was governed by fracture displacement, the lack of pre-existing osteoarthritis, length of time to diagnosis, the patient's age, ambulatory status and mental impairment, with the intention to minimize post-operative complications such as avascular necrosis, non-union and hip dislocation.

Direct anterior approach for total hip arthroplasty using the fracture table

Total hip arthroplasty is a successful procedure for treatment of painful hip arthritides. A large volume of literature is devoted to the patient outcomes and complication profiles of the commonly used surgical approaches to help refine the technique, enhance patient function, and limit cost and patient morbidity. The direct anterior approach has been reported using a fracture table to promote surgical exposure to the proximal femur. This technique is described herein with attention paid to the technical points which facilitate surgical exposure, patient safety, and functional outcome. Following a literature review of recent reports using this procedure are reviewed in context of the reported complications. The results show the direct anterior approach using a fracture table performed by experienced surgeons is an effective technique which provides early postoperative function and reduces the risk of dislocation.

[Avoidance, diagnostics and therapy of nerve lesions after total hip arthroplasty]

Nerve palsy following total hip arthroplasty is a rare complication. Developmental dysplasia of the hip, previous fracture treatment and medical comorbidities are characteristic risk factors. By accurate preparation of the patient and a careful operative technique nerve palsy can be avoided in most cases. Nerve palsy following poor patient positioning during the perioperative period should be avoided by close cooperation with anesthesiologists.In cases of postoperative nerve palsy correct diagnostics should be carried out immediately. Further treatment options should be considered to minimize the damage. For patients with definite nerve palsy, devices such as a foot drop splint are often necessary and should be carried out as soon as possible.

No clinical difference between large metal-on-metal total hip arthroplasty and 28-mm-head total hip arthroplasty?

PURPOSE

We aimed to test the claim of greater range of motion (ROM) with large femoral head metal-on-metal total hip arthroplasty.

METHODS

We compared 28-mm metal-on-polyethylene (MP) total hip arthroplasty with large femoral head metal-on-metal (MM) total hip arthroplasty in a randomised clinical trial. ROM one year postoperatively was determined in 50 patients. Mean head sizes were 28 mm (MP) and 48 mm (MM).

RESULTS

After one year, the large head MM group showed greater improvement in internal rotation (14 degrees) than the 28 mm group (seven degrees).There were no significant differences in the absolute values of postoperative internal rotation, external rotation, flexion, extension, abduction and abduction.

CONCLUSIONS

Absolute postoperative range of motion did not differ between the two groups. The improvement in internal rotation was greater after large femoral head metal-on-metal total hip arthroplasty. It is however questionable whether this difference is clinically relevant.

Effect of surgical approach for total hip replacement on hip function using Harris Hip scores and Trendelenburg's test. A retrospective analysis

OBJECTIVE

A retrospective analysis of osteoarthritis patients undergoing primary hip arthroplasty, to assess which surgical approach produces the best functional results at one-year post-operatively, using common clinical scoring systems and tests. The aim of this study was to compare the anterolateral and the posterior approaches to total hip arthroplasty using Harris Hip scores and Trendelenburg's test by looking at pre-operative results and comparing them to post-operative results.

METHODS

Data from 3416 consecutive cases were extracted from a multicentre database, maintained by the Tayside Arthroplasty Audit Group (TAAG) situated in Tayside, using only patients who had undergone a primary hip arthroplasty and had a clinical diagnosis of osteoarthritis.

RESULTS

Analysis showed that there was statistically significant difference between the two approaches for Harris Hip score (p = 0.0344), Harris Hip function score (p = 0.0035) and Trendelenburg Test (p =< 0.00001). The posterior approach showed larger improvements in Harris Hip scores. There was an increased incidence of dislocation in the posterior approach group (6.9%) but an increased incidence of Trendelenburg gait in anterolateral approach group (5.7%). It was found that patients who suffered a dislocation had similar functional outcomes for both groups with no statistical difference.

CONCLUSIONS

These results suggest that there may be benefit in using a posterior approach to primary total hip arthroplasty but due to limitations of the data within this study further more detailed research is required.

Short-term outcome after posterior versus lateral surgical approach for total hip arthroplasty - A randomized clinical trial

Purpose

Currently, total hip replacement (THR) is most commonly performed via a posterior or a direct lateral approach, but the impact of the latter on the invention's outcome has yet not been quantified.

Methods

We compared the short-term outcome of cementless THR using the both approaches in a prospective, randomized controlled trial. 60 patients with unilateral osteoarthritis were included. Outcome assessment was performed one day before surgery and one week, four weeks, six weeks and 12 weeks after surgery, respectively, using the Harris Hip score as primary objective.

Results

We found no significant difference in the intraindividual Harris Hip Score improvement at the pre-and three months post-operative assessments between both treatment groups (p = 0.115). However, Harris Hip scores and most functional and psychometric secondary endpoints showed a consistent tendency of a slightly better three months result in patients implanted via the posterior approach. In contrast a significant shorter operating time of the direct lateral approach was recorded (67 minutes versus 76 minutes, p < 0.001).

Conclusion

In our opinion this slightly better short-term functional outcome after posterior approach is not clinical relevant. However, to make definitive conclusions all clinical relevant factors (i.e. mid- to long-term function, satisfaction, complication rates and long-term survival) have to be taken into account. Level of evidence: I - therapeutic

The elderly were under-represented in osteoarthritis clinical trials

OBJECTIVES

Osteoarthritis is the most common disease affecting joints in the elderly. We aimed to evaluate if elderly patients are properly represented in clinical trials of diverse osteoarthritis interventions.

STUDY DESIGN AND SETTING

Clinical trials of osteoarthritis interventions were retrieved from Cochrane Library systematic reviews (2006, issue 2). We examined the age distribution of the trial participants and eligibility criteria.

RESULTS

We analyzed data from 219 eligible trials from 18 systematic reviews. The average mean age of the participants was 63 years. Only 13 trials (6.4%) had a mean age between 71 and 80 years and only one trial had a mean age exceeding 80 years. Among trials where the age range of participants was available or could be approximately inferred, we estimated that 66 (38%) trials had not included any patients over 80 years old. Only 23 trials specifically excluded patients over 70 based on reported eligibility criteria, but 168 trials excluded patients with various comorbidities and 142 trials excluded patients receiving other specific treatments.

CONCLUSIONS

Elderly patients are considerably under-represented in clinical trials of osteoarthritis. This causes an important deficit in the utility, relevance, and generalizability of trial results for this very common condition.

Acetabular orientation: anterolateral approach in the supine position

The anterolateral approach in the supine position provides excellent visualization of the acetabulum. The main advantage of the approach, a low dislocation rate, has been demonstrated in the literature, while the purported disadvantage of abductor dysfunction has not been clearly delineated in the literature. The technique requires meticulous attention to preservation of the gluteus medius and minimus tendons. Impingement and dislocation are avoided by careful attention to the preparation of acetabulum, critical assessment of the implanted components, and intraoperative trialing. Leg lengths are assessed through direct palpation of the malleoli. Routine use of postoperative hip precautions is not necessary when this approach is utilized. The anterolateral approach in the supine position allows for a reproducible result with a low dislocation rate.

LEVEL OF EVIDENCE

Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

THE INFLUENCE OF THE SURGICAL APPROACH CONCERNING DISLOCATION IN TOTAL HIP ARTHROPLASTY

Objectives: Our primary aim was to evaluate the occurrence of dislocation of non-cemented total hip arthroplasty, when using the posterior and the direct lateral approaches. Methods: We performed a comparative retrospective study with 232 patients submitted to non-cemented total hip arthroplasty, due to the diagnosis of primary or secondary osteoarthritis. The posterior approach was used in 105 patients while direct lateral approach was used in 127 patients. There was only one prosthesis model and the same rehabilitation program and post-operative care was used for all patients. We checked the occurrence of dislocation, the acetabular positioning and also the size of the components. Results: There was only one case of dislocation, treated with closed reduction successfully. This was a 47 year-old female, submitted to direct lateral approach. The mean follow-up time for both groups was 23.7 months, ranging from six to 42 months. Conclusion: The authors conclude that the prevalence of total hip arthroplasty dislocation is similar for both approaches, and educational measures besides the use of a higher femoral offset seem to reduce the risk of this complication.

Obesity is a major risk factor for prosthetic infection after primary hip arthroplasty

The incidence of obesity and the number of hip arthroplasties being performed in Australia each year are increasing. Although uncommon, periprosthetic infection after surgery can have a devastating effect on patient outcomes. We therefore asked whether obesity correlated with periprosthetic infection after primary hip arthroplasty. We further asked whether variables such as patient comorbidities, operative time, blood transfusions, use of drains, and cementation practices correlated with periprosthetic infection. We hypothesized obesity was an independent risk factor for the development of acute periprosthetic infection after primary hip arthroplasty. We reviewed 1207 consecutive primary hip arthroplasties separating patients into four weight groups, normal, overweight, obese, and morbidly obese, and compared for incidence of periprosthetic infection between the groups. We observed a considerably higher infection rate in obese patients; the correlation was independent of patient comorbidities such as diabetes and cardiovascular disease. We also observed a correlation between infection rates and using a posterior approach in obese patients. The incidence of periprosthetic infection was not influenced by operative time, transfusion requirements, use of drains, and cementation practices. In this series, obesity was an independent risk factor for acute periprosthetic infection after primary hip arthroplasty.

LEVEL OF EVIDENCE

Level II, prognostic study.