Comparison of morphological changes of gluteus medius and abductor strength for total hip arthroplasty via posterior and modified direct lateral approaches

The anatomical course of the sciatic nerve in relation to different approaches in total hip arthroplasty

PURPOSE

Although sciatic nerve (SN) injury is relatively rare, it is a devastating complication after primary and revision total hip arthroplasty (THA). Therefore, precise localization of the SN is essential for arthroplasty surgeons.

METHODS

We dissected 50 hemipelves from formalin-fixed cadavers. The course and location of the sciatic nerve were investigated in relation to different approaches for THA with the help of anatomical landmarks like the greater trochanter (GT), the iliac tubercle, the ischial tuberosity (IschT), the infrapiriform foramen, and the suprapiriform foramen.

RESULTS

We found and exposed the sciatic nerve in all 50 specimens with no sex-specific differences. No SN was encountered up to 22 mm posterior from the GT. The zone affording the highest probability of finding the nerve was posterior to the GT between 32 and 55 mm in 39 (78%) cases, thus defining a danger zone for different approaches for the THA.

CONCLUSION

Special care should be taken with posterior and deep instrument placement between the GT and IschT during THA. Moreover, manipulations in the proximal third of the posterior approach reaching deep and posteriorly should be performed with the utmost care.

The Anatomical Course of the Superior Gluteal Vessel Bundle with Regard to Different Approaches in Total Hip Arthroplasty

BACKGROUND

Iatrogenic vascular injury during total hip arthroplasty (THA) is rare, reported at rates of 0.05 to 0.3%, but a potentially limb-threatening and life-threatening complication. We aimed to describe safe and danger zones for the superior gluteal vessel bundle (SGV bundle) with reference to different THA approaches.

METHODS

There were 27 formalin-fixed cadavers with 49 hemipelves dissected. The course and distribution of the SGV bundle were investigated with the help of anatomical landmarks like the greater trochanter, the iliac tubercle (IT), and the ischial tuberosity.

RESULTS

We found and exposed the SGV bundle in all 49 specimens with no sex-specific differences. No SGV bundle was encountered up to 28 mm from the greater trochanter and up to 16 mm below the IT. The zone with the highest probability of finding the vessels was 25 to 65 mm below the IT in 39 (80%) cases - defining a danger zone (in relation to the skin incision) in the proximal fourth for the direct anterior approach, in the proximal half for the antero-lateral approach, in the proximal fifth for the direct lateral approach, and almost no danger zone for the posterior approach.

CONCLUSIONS

Special care in proximal instrument placement should be taken during THA. When extending one of the surgical approaches, manipulations in the proximal, cranial surgical window should be performed with the utmost care to avoid SGV bundle injury.

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.

Pain and rehabilitation after total hip arthroplasty are approach dependent: results 6 weeks and 2 years after surgery in a multisurgeon, single-center, and prospective cohort study

PURPOSE

The aim of this study was the evaluation of pain, function, and overall satisfaction after total hip arthroplasty (THA) using three different standard surgical approaches (DAA (direct anterior approach), lateral, and posterior approach) 2 years postoperatively. Additionally, we compared the results with recently published results of the same study population 6 weeks postoperatively.

METHODS

In a multisurgeon, prospective, single-center cohort study, a total of initial 188 patients who underwent total hip arthroplasty (THA) between February 2019 and April 2019 were analyzed on pain, function, and satisfaction within the first days, 6 weeks, and 2 years postoperatively according to three different approaches (DAA, lateral, and posterior approach). Our research group recently published results directly and 6 weeks postoperatively. We evaluated the same study collectively 2 years postoperatively and compared the results with the data 6 weeks postoperatively. One hundred twenty-five patients could be included. Outcome parameters for the present study were the pain level according to the visual analogue scale (VAS), the modified Harris hip score (mHHS), and an overall satisfaction scale 2 years postoperatively.

RESULTS

Mean overall satisfaction 2 years postoperatively was 9.7 ± 1 (3-10). Satisfaction was significantly better for the DAA than for the lateral approach (p = 0.005). There were no significant differences between the lateral and posterior approaches (p = 0.06) and between the DAA and the posterior approaches (p = 0.11). In total, the mean pain level was 0.4 ± 0.9 (0-5) at 6 weeks and 0.5 ± 1.1 (0-7) at 2 years postoperatively (p = 0.3). Regarding the different approach groups, pain levels 6 weeks and 2 years postoperatively were significantly lower for the DAA than for the lateral approach (p = 0.02). There were no significant differences between DAA and posterior approach (p = 0.05) and the lateral and posterior approach (p = 0.26). The mean mHHS significantly increased from 84.7 + 14.5 (37.4-100) 6 weeks to 95 + 12.5 (23.1-100.1) 2 years postoperatively (p < 0.0001). Regarding the different approaches, mHHS was significantly higher for the DAA than for the lateral approach (p = 0.03). Differences between the DAA and the posterior approach (p = 0.11) and between the lateral and posterior approaches (p = 0.24) were insignificant.

CONCLUSION

At 2 years postoperative, DAA showed significantly better overall satisfaction, pain level, and mHHS than the lateral approach. The differences between DAA and the posterior approach and lateral and posterior approaches were insignificant. Whether the superior results of the DAA to the lateral approach persist over a longer period must be clarified by further studies.

STUDY DESIGN

Prospective cohort study, level of evidence 2.

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.

Superior Transverse Atraumatic Reconstruction (STAR) approach provides a better-compared outcome to standard Direct Superior Approach (DSA): a matched, prospective comparative single-surgeon study

INTRODUCTION

The Direct Superior Approach (DSA) is a muscle-sparing hip approach that does not protect the piriformis and the other short external rotators. We present a DSA modification we named STAR (Superior Transverse Atraumatic Reconstruction), which has DSA advantages but always preserves piriformis. Our study compared the early postoperative, radiological, and functional results of patients undergoing primary total hip arthroplasty (THA) through the STAR approach with a matched DSA group performed by a senior surgeon.

METHODS

Each group, DSA, and STAR included 200 elective primary unilateral THAs performed by the surgeon between 2016-2017 and 2020-2021, respectively. Patients were included in both groups using the same inclusion criteria. Both groups were matched for age and sex. The same postoperative pain management, chemoprophylaxis, and physiotherapy protocols were followed in both groups. Two independent orthopaedic surgeons performed the clinical and radiological follow-up.

RESULTS

The STAR group had significantly lower mean incision length (p = 0.042) and hospital stay (p = 0.002) than the DSA group. The mean intraoperative blood loss (p = 0.085) and the need for blood transfusion (p = 0.228) were less for the STAR than the DSA group. The mean postoperative functional scores improvement was significantly higher for the STAR than the DSA group at the end of the first and third postoperative months.

CONCLUSIONS

The STAR approach offers earlier functional improvement, shorter hospital stay and less transfusion need than DSA for patients undergoing primary THA. Both approaches showed a limited complication risk and an outstanding acetabular and femoral access enabling the procedure.

Pain and rehabilitation after total hip arthroplasty are approach dependent: a multisurgeon, single-center, prospective cohort study

PURPOSE

The aim of this study was to assess perioperative pain and mobilization after total hip arthroplasty (THA) using three different surgical approaches.

METHODS

This was a multisurgeon, prospective, single-center cohort study. A total of 188 patients who underwent hip arthroplasty (THA) between February 2019 and April 2019 were analyzed according to the surgical approach used (direct anterior, lateral, and posterior approach). Outcome parameters were the daily walking distance during the inpatient stay, the pain level according to the visual analog scale (VAS) at rest and motion during the inpatient stay and at 6-week follow-up and the modified Harris Hips Score (mHHS) preoperatively and at 6 weeks.

RESULTS

The walking distance within the groups increased significantly during the inpatient stay (p < 0.001). The DAA and posterior approach patients had a significantly longer walking distance than the lateral approach patients on the third postoperative day (DAA vs. lateral, p = 0.02; posterior vs. lateral 3, p = 0.03). DAA and posterior approach patients reported significantly less pain during motion on the third postoperative day and at 6-week follow-up than the lateral approach patients (3 postoperative day: DAA vs. lateral, p = 0.011; posterior vs. lateral, p = 0.04; 6 weeks control: DAA vs. lateral, p = 0.001; Posterior vs. lateral 3, p = 0.005). The mHHS demonstrated significant improvement within each group. However, lateral approach patients reported significantly less improvement than the DAA and posterior approach patients (DAA vs. lateral, p = 0.007; posterior vs. lateral, p = 0.021).

CONCLUSION

This study analyzed perioperative pain progression and short-term rehabilitation after THA according to the different surgical approaches. Direct anterior and posterior approaches have shown comparable improvements in pain, walking distance, and mHHS. Whether this effect persists over a longer period of time must be clarified in future studies.

STUDY DESIGN

Prospective cohort study, level of evidence, 2.

Simultaneous versus staged bilateral total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Total hip arthroplasty is a common orthopedic surgery for treating primary or secondary hip osteoarthritis. Bilateral total hip replacement could be performed in a single stage or two separate stages. Each surgical procedure's reliability, safety, and complications have been reported controversially. This study aimed to review the current evidence regarding the outcomes of simultaneous and staged bilateral total hip arthroplasty.

METHODS

We conducted a meta-analysis using MEDLINE, EMBASE, Web of Science, and Scopus databases. Eligible studies compared complications and related outcomes between simultaneous and staged bilateral THA. Two reviewers independently screened initial search results, assessed methodological quality, and extracted data. We used the Mantel-Haenszel method to perform the meta-analysis.

RESULTS

In our study, we included 29,551 patients undergoing simBTHA and 74,600 patients undergoing stgBTHA. In favor of the simBTHA, a significant reduction in deep vein thrombosis (DVT) and systemic, local, and pulmonary complications was documented. However, we evidenced an increased pulmonary embolism (PE) and periprosthetic fracture risk in simBTHA. In the simBTHA, total blood loss, length of hospital stay, and total cost were lower.

CONCLUSION

This meta-analysis shows that simultaneous bilateral THA accompanies fewer complications and lower total cost. Well-designed randomized controlled trials are needed to provide robust evidence.

Earlier functional recovery and discharge from hospital for THA patients operated on via direct superior compared to standard posterior approach: a retrospective frequency-matched case-control study

BACKGROUND

The direct superior hip approach (DSA) has been less researched than other approaches in the literature. We retrospectively compared the early postoperative and functional outcomes of patients with hip osteoarthritis undergoing total hip arthroplasty (THA) via DSA with a matched control group using a standard posterior approach (SPA).

METHODS

The DSA group comprised 100 THAs performed via DSA by a senior surgeon between January 2018 and May 2019. Patients with primary osteoarthritis and ASA score ⩽3 who were eligible for surgery were included. The DSA group was compared to a matched cohort of 100 patients operated on with a SPA in the same period by another chief surgeon. Patients were matched for age, sex, and ASA score. All patients received the same postoperative chemoprophylaxis, pain management and physiotherapy. 2 independent attending arthroplasty surgeons assessed the incision length, operative time, blood loss, hospital stay, and complications. VAS, HHS, and HOOS scores were also evaluated for a year postoperatively.

RESULTS

Mean incision length and hospital stay were significantly lower in the DSA group. DSA patients had non-significantly lower intraoperative blood loss, transfusion needs, and postoperative pain than SPA patients. Mean operation time and complication rate did not differ between groups. The DSA group demonstrated significantly greater functional scores than the SPA group at the first postoperative month. No differences in scores were recorded following the third month.

CONCLUSIONS

The DSA approach may provide earlier functional recovery and hospital discharge for THA patients compared with SPA. DSA was equivalent to SPA concerning pain and blood loss, showing minimal complication rates.

Fragility fracture following total hip arthroplasty

BACKGROUND

While periprosthetic fractures following total hip arthroplasty (THA) are a well-known phenomenon for orthopedic surgeons, fragility fractures following THA are also a significant, though less studied, concern. Furthermore, patients who have undergone THA have several additional risk factors for fragility fractures, including motor weakness, bone atrophy, and limping. The aims of this study were to evaluate the incidence of fragility fractures following THA and to clarify the characteristics of these fractures.

METHODS

This study included 5678 primary THA procedures in 4589 female patients. This study evaluated body morphology data, disease type leading to THA, Japanese Orthopaedic Association hip score, range of motion of the hip joint, and medical history. Distal radius and patella fractures were defined as fragility fractures. Risk factors for fragility fractures after THA were calculated by comparing the fragility fracture group with the non-fracture group.

RESULTS

Fifty-three fragility fractures were confirmed in 53 patients (distal radius fracture: 32 fractures in 32 patients, patella fracture: 21 fractures in 21 patients). In the univariate analysis, the following eight risk factors for fragility fractures were significantly different between the groups: height, weight, follow-up period, developmental dysplasia of the hip, primary osteoarthritis, abduction before THA, internal rotation before THA, and external rotation before THA. Medical histories were not significantly different between the groups. There was no difference in any study factor and in the time of occurrence between the radius fractures and patella fractures analyzed as fragility fractures.

CONCLUSIONS

This study revealed that there are significant preoperative factors of fragility fractures following THA. These factors will serve as useful data for THA treatment strategies, preoperative explanations, and future studies.

Overview of Methods to Quantify Invasiveness of Surgical Approaches in Orthopedic Surgery—A Scoping Review

Background

There is a trend toward minimally invasive and more automated procedures in orthopedic surgery. An important aspect in the further development of these techniques is the quantitative assessment of the surgical approach. The aim of this scoping review is to deliver a structured overview on the currently used methods for quantitative analysis of a surgical approaches' invasiveness in orthopedic procedures. The compiled metrics presented in the herein study can serve as the basis for digitization of surgery and advanced computational methods that focus on optimizing surgical procedures.

Methods

We performed a blinded literature search in November 2020. In-vivo and ex-vivo studies that quantitatively assess the invasiveness of the surgical approach were included with a special focus on radiological methods. We excluded studies using exclusively one or multiple of the following parameters: risk of reoperation, risk of dislocation, risk of infection, risk of patient-reported nerve injury, rate of thromboembolic event, function, length of stay, blood loss, pain, operation time.

Results

The final selection included 51 articles. In the included papers, approaches to 8 different anatomical structures were investigated, the majority of which examined procedures of the hip (57%) and the spine (29%). The different modalities to measure the invasiveness were categorized into three major groups “biological” (23 papers), “radiological” (25), “measured in-situ” (14) and their use “in-vivo” or “ex-vivo” was analyzed. Additionally, we explain the basic principles of each modality and match it to the anatomical structures it has been used on.

Discussion

An ideal metric used to quantify the invasiveness of a surgical approach should be accurate, cost-effective, non-invasive, comprehensive and integratable into the clinical workflow. We find that the radiological methods best meet such criteria. However, radiological metrics can be more prone to confounders such as coexisting pathologies than in-situ measurements but are non-invasive and possible to perform in-vivo. Additionally, radiological metrics require substantial expertise and are not cost-effective. Owed to their high accuracy and low invasiveness, radiological methods are, in our opinion, the best suited for computational applications optimizing surgical procedures. The key to quantify a surgical approach's invasiveness lies in the integration of multiple metrics.

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.

Functional characteristics associated with hip abductor torque in severe hip osteoarthritis

BACKGROUND

Hip abductor weakness due to the progression of hip osteoarthritis (OA) commonly causes poor functional mobility. The hip abductor strength has also been identified as a clinically relevant factor for successful functional outcomes after total hip arthroplasty.

OBJECTIVES

This study aimed to examine the functional characteristics related to hip abductor torque in patients with hip OA.

DESIGN

A cross-sectional survey study.

METHODS

One hundred and eight female patients with severe unilateral hip OA participated in this study. Hip abductor torque and pain were measured. The muscle cross-sectional area (CSA) and skeletal muscle density (SMD) of the gluteal muscles were also measured using computed tomography. To identify the hip parameters associated with hip abductor torque, multiple regression analysis was performed. The healthy model included the CSA and SMD of gluteus maximus, gluteus medius, and gluteus minimus; range of motion in hip abduction; age; and body mass index. The affected model included hip pain in addition to the healthy model.

RESULTS

In the affected limb, multiple regression analysis identified pain and angle of hip abduction as factors that determine hip abductor torque (Adjusted R² = 0.39). In contrast, our analysis identified CSA and SMD of the gluteus medius and SMD of the gluteus minimus as the significant variables related to hip abductor torque in the healthy limb (Adjusted R² = 0.40).

CONCLUSION

The findings of this study indicated that it is necessary to consider that hip pain may inhibit muscle exertion and contraction while training to improve the hip abductor torque in the affected limb.

Histological and ultrastructural degenerative findings in the gluteus medius tendon after hip arthroplasty

Background

Despite gluteus medius (GMED) tendinosis being relatively common, its presence in association with hip osteoarthritis (OA) or total hip arthroplasty (THA) is not well studied. It was hypothesized that more tendon degeneration would be found in patients with OA of the hip and in those that had undergone THA than that in a control group.

Methods

One hundred patients were included between 2016 and 2019 and were included into 4 groups; the patients were undergoing revision surgery in two groups and primary THA in the other two groups; 22 patients had previously undergone primary THA through a direct lateral approach (involving sectioning of the GMED tendon), 24 patients had previously undergone primary THA through a posterior approach (leaving the GMED tendon intact), 29 patients had primary hip OA, and 25 patients who suffered a femoral neck fracture served as controls. Biopsies from the GMED tendon were obtained at the time of the primary THA or the hip revision surgery. The tendon biopsies were examined ultrastructurally and histologically.

Results

Ultrastructurally, the direct lateral and posterior revision groups had statistically significantly more collagen fibrils with smaller diameters compared with the fracture and primary THA groups. Moreover, the direct lateral revision group had more collagen fibrils with smaller diameters compared with the posterior revision group.

Histologically, the direct lateral revision group had a higher total degeneration score (TDS) compared with the primary hip OA group.

Conclusions

The GMED tendon shows more ultrastructural degeneration in patients who undergo hip revision arthroplasty than in patients with primary OA of the hip and control patients, who had suffered a femoral neck fracture. Furthermore, patients who had previously undergone primary THA through a direct lateral approach revealed more histological GMED tendon degeneration than patients who suffer primary hip OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02434-1.

MARS MRI assessment of fatty degeneration of the gluteal muscles in patients with THA: reliability and accuracy of commonly used classification systems

INTRODUCTION

Fatty degeneration of the gluteal muscles on metal artefact reduction sequence (MARS) MRI has been shown to correlate with poor functional outcomes, particularly in patients with total hip arthroplasty (THA). Standardized, reliable classification systems that permit assessment of fatty gluteal infiltration are needed for clinical decision making. This study aimed to compare the reproducibility and accuracy of commonly used MRI classification systems for fatty gluteal atrophy in THA patients.

METHODS

MARS magnetic resonance images of 82 patients with unilateral THA were analysed by three independent trained observers. The readers evaluated fatty degeneration of the gluteus minimus, gluteus medius, and gluteus maximus according to 3 widely used classification systems: Goutallier, Quartile, and Bal and Lowe. Interobserver and intraobserver repeatability were determined using the weighted Kappa test. Quantitative evaluation of the proportion of intramuscular fat based on MR signal intensities was obtained and represented the gold standard.

RESULTS

Mean interobserver agreement for the Quartile classification system (0.93) was higher compared with Goutallier classification system (0.87) and the Bal and Lowe classification system (0.83; range 0.79-0.88; p = 0.04). Intraobserver repeatability was significantly higher for the Quartile classification system (weighted kappa 0.91, 0.89, 0.85) compared with the Bal and Lowe classification system (weighted kappa 0.83, 0.77, 0.75; p < 0.01) and Goutallier classification system (weighted kappa 0.83, 0.77, 0.75; p = 0.04). Agreement with the gold standard measurements was significantly higher in the Quartile classification system (0.88, 0.84, 0.81) compared with the Goutallier classification system (0.80, 0.77, 0.78; p = 0.02) and Bal and Lowe classification system (0.76, 0.74, 0.73; p < 0.01).

DISCUSSION

This study directly compared three clinically used MRI classification systems for fatty gluteal muscle atrophy in THA patients. Our findings demonstrate that although all three classification systems demonstrate good reproducibility and accuracy, the Quartile classification system is superior to the others in terms of intraobserver reliability and accuracy to quantify fatty gluteal degeneration in THA patients.

A systematic review and meta-analysis of the hip capsule innervation and its clinical implications

Detailed understanding of the innervation of the hip capsule (HC) helps inform surgeons' and anaesthetists' clinical practice. Post-interventional pain following radiofrequency nerve ablation (RFA) and dislocation following total hip arthroplasty (THA) remain poorly understood, highlighting the need for more knowledge on the topic. This systematic review and meta-analysis focuses on gross anatomical studies investigating HC innervation. The main outcomes were defined as the prevalence, course, density and distribution of the nerves innervating the HC and changes according to demographic variables. HC innervation is highly variable; its primary nerve supply seems to be from the nerve to quadratus femoris and obturator nerve. Many articular branches originated from muscular branches of the lumbosacral plexus. It remains unclear whether demographic or anthropometric variables may help predict potential differences in HC innervation. Consequently, primary targets for RFA should be the anterior inferomedial aspect of the HC. For THA performed on non-risk patients, the posterior approach with capsular repair appears to be most appropriate with the lowest risk of articular nerve damage. Care should also be taken to avoid damaging vessels and muscles of the hip joint. Further investigation is required to form a coherent map of HC innervation, utilizing combined gross and histological investigation.