Could the tendon degeneration and the fatty infiltration of the gluteus medius affect clinical outcome in total hip arthroplasty?

Fatty infiltration of periarticular muscles in patients with osteonecrosis of the femoral head

PURPOSE

Muscle mass and fatty infiltration can be assessed on computed tomography (CT) images using the cross-sectional area (CSA) and computed tomography attenuation value (CTV). Femoral head collapse in osteonecrosis of the femoral head (ONFH) may affect both values. We investigated factors influencing the CSA and CTV of the periarticular muscles in patients with ONFH.

METHODS

Overall, 101 patients with ONFH with unilateral hip pain (stage 2, 24 patients; stage 3 A, 49 patients; and stage 3B, 28 patients) were included. The CSA and mean CTV of the bilateral gluteus maximus (Gmax), gluteus medius (Gmed), gluteus minimus (Gmin), and iliopsoas (IP) muscles were measured using CT cross-sections. Bilateral comparisons and associations with Japanese Investigation Committee (JIC) stage were analysed. Multiple regression analysis was used to evaluate factors associated with the CSA and CTV.

RESULTS

On the symptomatic side, the CSA was significantly lower for the Gmax, Gmed, and IP, whereas the CTV was significantly lower for all tested muscles (all p < 0.01). The CTV, but not the CSA, of the Gmax, Gmed, and Gmin was significantly associated with the JIC stage severity bilaterally (all p < 0.01). Multiple regression analysis showed significant associations of the CTV with age, sex, and JIC stage (all p < 0.01).

CONCLUSION

Symptomatic ONFH leads to decreased muscle mass and increased fatty infiltration. Femoral head collapse progression is associated with a decrease in the CTV. Periarticular muscle assessment, including on the contralateral side, is important in patients with ONFH, particularly in older women.

Fatty Infiltration of Muscles Influences Short-term Walking Speed after Primary Total Hip Arthroplasty

Objectives

This study aimed to determine the relationship between preoperative fatty infiltration of the lower extremity muscles and walking speed at 2 weeks after total hip arthroplasty (THA).

Methods

This was a single-institution retrospective cohort study. Participants in this study were patients undergoing primary THA. Fatty infiltration in each muscle (bilateral psoas major, gluteus maximus, gluteus medius, gluteus minimus, quadriceps, and triceps surae) was assessed using non-contrast X-ray computed tomography images obtained during a detailed preoperative examination. The outcome of this study was the normal comfortable walking speed at 2 weeks after THA. Decreased walking speed was defined as less than 0.8 m/s (non-decreased group, coded 0; decreased group, coded 1). Multivariate logistic regression analysis was used to analyze the relationship between fatty infiltration of each skeletal muscle and walking speed.

Results

A total of 168 participants were included in the analysis. On the operative side, the analysis identified fatty infiltration of the gluteus medius (odds ratio, 0.95; 95% confidence interval, 0.91-0.99) as a determinant of decreased walking speed after THA. On the nonoperative side, the analysis identified fatty infiltration of the quadriceps (odds ratio, 0.91; 95% confidence interval, 0.83-0.99) as a determinant of decreased walking speed after THA.

Conclusions

In patients undergoing THA, increased fatty infiltration of the gluteus medius on the operative side and the quadriceps on the nonoperative side were associated with decreased walking speed at 2 weeks postoperatively.

MR Imaging Diagnosis of Greater Trochanteric Syndrome

Greater trochanteric syndrome (GTS) is a common condition clinically manifested by pain and tenderness over the greater trochanter. MR imaging plays a pivotal role in investigating the underlying cause of GTS. MR imaging can detect abnormalities not only in symptomatic but also in asymptomatic hips, thereby revealing structural damage in the gluteal tendons and muscles during both clinical and preclinical phases. This review article emphasizes the importance of detailed knowledge of anatomy of the greater trochanter and adjacent soft tissues, along with the imaging appearance of pathology of the abductor tendons and muscles as well as the peritrochanteric bursae.

What Is the Prevalence of Hip Abductor Pathology in Patients Undergoing Total Hip Arthroplasty?

Background

Total hip arthroplasty (THA) is generally considered a successful operation for patients with advanced hip arthritis. Hip abductor pathology can lead to diminished outcomes. The prevalence of hip abductor pathology in patients undergoing THA is not well described.

Methods

Our institution's arthroplasty registry was queried to identify patients undergoing THA who had preoperative magnetic resonance imaging (MRI) of the hip or pelvis. MRIs were reviewed for presence of abductor (gluteus medius or gluteus minimus) tendon injury. Dysfunction of the abductor musculotendinous units was assessed by grading fatty infiltration of the muscle bellies using the Goutallier/Fuchs classification.

Results

A total of 1090 primary THAs were performed during the study period, and 118 (10.8%) patients had a preoperative MRI of the hip or pelvis ≤12 months prior to surgery. Among the 118 patients who had an MRI, abductor tendon tears were diagnosed in 33 patients (28.0%), and tendinosis was noted in 106 patients (89.8%).

Conclusions

There is a high prevalence of hip abductor pathology in patients presenting for THA. Clinicians should evaluate patients for signs of abductor tendon pathology when presenting for consideration of THA. Careful examination and MRI may be helpful to further evaluate the status of the gluteus minimus and gluteus medius musculotendinous units.

Outcomes of Direct Anterior Total Hip Arthroplasty in Patients Who Have Preoperative Gluteal Tendinopathy and Muscle Tears: A Propensity-Matched Analysis

BACKGROUND

The gluteus medius and minimus muscles play a critical role in hip biomechanics; however, there is a paucity of literature examining the impact of preoperative gluteal pathology on outcomes following total hip arthroplasty (THA). This study compared pain, satisfaction, and functional outcomes among patients who had and did not have preoperative gluteal pathology after direct anterior (DA) THA.

METHODS

Using an institutional total joint registry, patients undergoing DA THA for osteoarthritis between 2010 and 2022 were retrospectively reviewed. Those who had magnetic resonance imaging evidence of gluteal muscle tear or tendinopathy within one year before surgery were propensity-matched on a 1:4 basis by age, sex, body mass index, laterality, year of surgery, and surgeon to patients who had no clinical evidence of abductor pathology. There were 22 patients who had gluteal tears (eight of 22 men, age 63 ± 8.1 years) and 29 who had gluteal tendinopathy (nine of 29 men, age 60 ± 10.4 years) who were respectively matched to 88 and 116 controls and followed for 4.0 ± 2.3 (range, 1.1 to 12.7) years following DA THA. Postoperative outcomes were assessed using a visual analog scale (VAS) at rest, VAS with use, Hip Disability and Osteoarthritis Outcome Score pain, Forgotten Joint Score-12, and modified Harris Hip Score (mHHS). Subsequent injections and reoperations were recorded.

RESULTS

While all achieved excellent outcomes, patients who had gluteal muscle tears experienced less improvement in pain and function compared to controls, trending toward a lower final mHHS score (P = 0.052). Patients who had gluteal tendinopathy reported worse pain, satisfaction, and function than controls according to measures of VAS at rest (P = 0.014), VAS with use (P = 0.003), Hip Disability and Osteoarthritis Outcome Score pain (P = 0.005), Hip Disability and Osteoarthritis Outcome Score (P = 0.003), and mHHS (P = 0.007). Postoperative injections and subsequent hip surgeries were infrequent despite no intraoperative tendon treatment. Key limitations included limited sample size and lack of intraoperative data.

CONCLUSIONS

Patients who had gluteal pathology do well following DA THA; however, gluteal muscle tears and tendinopathies are associated with greater pain, decreased satisfaction, and inferior functional outcomes.

Pre-operative gluteus medius tendon degeneration and its impact on strength and functional ability one year after total hip replacement

OBJECTIVE

Hip osteoarthritis is a common cause of disability and surgery is often unavoidable. Patient satisfaction is high and functional ability improves after surgery. However, residual impairment and pain are common. Degenerative changes in tendons and muscles are probable causes. The aim of this study is to investigate gluteus medius (GMED) tendon degeneration in relation to muscle strength, physical function and walking distance before and one year after total hip replacement.

MATERIAL AND METHODS

In total, 18 patients were examined pre- and post-operatively, of whom 15 were available in the final analysis. Muscle strength, physical function and walking distance were assessed. Tendon biopsies were assessed microscopically, and the total degeneration score (TDS) was calculated.

RESULTS

A correlation between the TDS and muscle strength was found for the hamstrings, GMED and quadriceps pre- or post-operatively. No correlations were found between the TDS and functional ability. Functional ability and muscle strength improved significantly after surgery.

CONCLUSION

Our results indicate a correlation between tendon degeneration and the muscle strength of the hip and knee in patients with hip OA and one year after THR. To minimise post-operative residual discomfort, rehabilitation programs should probably be modified over time to match the pre- and post-operative needs. Further studies are needed.This study was registered at https://www.researchweb.org/is/vgr/project/279039 (in Swedish).

Gluteal Tendinopathy Is Associated With Lower Patient-Reported Outcome Measures in Total Hip Arthroplasty With a Posterior Approach: A Prospective Cohort Study of 1,538 Patients

BACKGROUND

Gluteal tendinopathy (GT) is found in 20 to 25% of patients undergoing total hip arthroplasty (THA). Despite this, there is a scarcity of literature assessing the association between GT and THA outcomes. The aim of this study was to evaluate whether intraoperative diagnosis of GT negatively affected postoperative outcomes.

METHODS

Consecutive patients undergoing primary THA for osteoarthritis via a posterior approach over 5 years were recruited in a prospective study. Gluteal tendinopathy was assessed and graded at the time of surgery, but not repaired. A total of 1,538 (93%) completed the patient-reported outcome measures (PROMs) at 1 year after surgery and were included in the analysis. The PROMs included the Oxford Hip Score (OHS), Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR), and EuroQol 5-Dimension, and were collected preoperatively and one year after THA.

RESULTS

The gluteal tendons were graded as 4 distinct grades: normal (n = 1,023, 66%), tendinopathy but no tear (n = 337, 22%), partial thickness tear (n = 131, 9%), and full thickness tear (n = 47, 3%). The occurrence of GT was associated with age, body mass index, and sex. There was no significant difference in baseline OHS or HOOS JR scores according to GT grade. As GT grade increased, lower median 1-year OHS (P = .001) and HOOS JR (P = .016) were observed. This association was confirmed by linear regression analysis with 1-year OHS (B = 0.5, 95% CI = -0.9 to -0.1, P = .011) when controlled for age and sex.

CONCLUSIONS

Gluteal tendinopathy was commonly observed and was associated with inferior 1-year PROMs in patients undergoing THA via posterior approach. Increasing degree of tendinopathy was a negative prognostic factor for outcomes and patient satisfaction.

LEVEL OF EVIDENCE

Level 2 (High quality prospective cohort study).

Association of physical activity with fatty infiltration of muscles after total hip arthroplasty

OBJECTIVE

This study aimed to investigate the association between muscle density as an indicator of fatty infiltration of lower extremity muscles and physical activity (PA) after total hip arthroplasty (THA) and identify the patient characteristics with high postoperative PA.

METHODS

This study included 62 female patients who underwent THA for unilateral hip osteoarthritis. Muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles was measured using computed tomography (CT). PA was assessed using University of California, Los Angeles (UCLA) activity scores. CT and UCLA activity score were obtained before and 1 year after THA. The patients were divided into two groups, sufficient (score ≥ 6) and insufficient (score < 6) activity groups, based on their level of PA as determined by their UCLA activity score 1 year after THA. The association of PA with the amount of changes in muscle density was examined with Spearman's rank correlation coefficient. Logistic regression analysis was performed to identify postoperative factors determining PA at 1 year after THA.

RESULTS

Spearman's rank correlation coefficient showed a significantly positive association between recovery in PA and an increase in muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles. Additionally, logistic regression analysis confirmed that postoperative muscle densities of the gluteus maximus and quadriceps muscles were variables determining the PA 1 year after THA.

CONCLUSION

The findings of this study indicated that the improvement of fatty infiltration in lower limb muscles, especially in the gluteus maximus and quadriceps, is likely to promote the increase in postoperative PA.

Asymptomatic Gluteal Tendinosis Does Not Adversely Affect Outcomes of Primary Total Hip Arthroplasty

BACKGROUND

The aim of this study was to compare outcomes after total hip arthroplasty (THA) in patients who have preoperative asymptomatic gluteal tendinosis (aGT) to a control group with no gluteal tendinosis (GT).

METHODS

A retrospective analysis was performed using data from patients who underwent THA between March 2016 and October 2020. An aGT was diagnosed using hip magnetic resonance imaging (MRI) without clinical symptoms. Patients who had aGT were matched (1:1) to patients without GT on MRI. A total of 56 aGT hips and 56 hips without GT were found using propensity-score matching. Patient-reported outcomes, intraoperative macroscopic evaluation, outcome measurements, postoperative physical examinations, complications, and revisions were compared for both groups.

RESULTS

When compared to preoperative outcomes, both groups demonstrated significant improvements in patients-reported outcomes at the final follow-up. There were no significant differences between both groups for preoperative scores, 2-year postoperative outcome scores, or the magnitude of improvement. Patients in the aGT group were significantly less likely to obtain the MCID for the SF-36 MCS score (50.2 versus 69.3%, P = .034). However, there were no other differences in the rates of meeting the MCID between both groups. The aGT group demonstrated significantly higher rates of partial tendon degeneration of the gluteus medius muscle.

CONCLUSION

Asymptomatic gluteal tendinosis patients who have osteoarthritis and undergo THA may expect favorable patients-reported outcomes at minimum 2-year follow-up. These results were comparable with those of a control group of patients without gluteal tendinosis.

LEVEL OF EVIDENCE

III.

Outcomes analysis of anterior and lateral approach for open repair of hip abductor tendons

BACKGROUND

Gluteal tendons tears are increasingly being recognised as a cause of recalcitrant trochanteric pain, but there is a paucity of robust studies analysing the type of tears, results and predictors of outcome.

METHODS

Patients with gluteal tendon tears resistant to conservative treatment who underwent isolated open repair (IR) or total hip arthroplasty and concomitant repair (THA+repair) with a minimum 1-year follow-up were retrospectively assessed separately. Type of tear, surgical approach, and fixation methods were registered. Complications and postoperative outcomes were analysed: visual analogue scale (VAS) of pain, VAS satisfaction, and activity level. Univariate regressions and multivariable models were developed.

RESULTS

90 cases were included: 62 cases underwent IR and 28 cases THA+repair, with an average follow-up of 3.9 years and 2.6 years, respectively. 13 complications were found (n = 5 IR, n = 8 THA+repair), including 9 re-operations (n = 4 IR, n = 5 THA+repair). Mean VAS pain score was 3.02 (SD 2.74) for the IR and 2.32 (SD 2.43) for THA+repair group. Mean VAS satisfaction was 7.09 (SD 3.07) and 7.68 (SD 2.71) for the IR and THA+repair group, respectively. In the IR group 61.4% returned to all pre-injury activities, whereas in the THA+repair group 79% did. Full-thickness tears had higher VAS pain scores (p = 0.0175), and there was trend (p > 0.05) towards higher complications, re-tears and lower VAS satisfaction in this type of tears in both groups. No statistically significant differences were found in outcomes when comparing THA+repair through direct anterior (DAA) with lateral approach (LA).

CONCLUSIONS

Isolated gluteal tendon repair or THA+repairs seem to be safe procedures with high levels of satisfaction at short- to mid-term follow-up. The presence of a full-thickness tear is a predictor of inferior outcomes.

Evaluating the contribution of fat infiltration in anterior gluteus minimus muscle to walking ability in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty

BACKGROUND

The purpose of this study is to investigate the relationship between gait and fat infiltration in anterior and posterior gluteus minimus in the patients with hip osteoarthritis.

METHODS

Ninety-one female patients who were diagnosed as the unilateral hip osteoarthritis, classified into Kellgren-Lawrence global scoring system grades 3 or 4, and candidate for total hip arthroplasty were retrospectively reviewed. The horizontally cross-sectional regions of interest for the gluteus medius and anterior and posterior gluteus minimus were manually circumscribed in a single transaxial computed tomography image and muscle density of those regions were obtained. The gait was assessed as the step and speed with the 10-Meter Walk Test. The multiple regression analysis was used to compare the step and speed with age, height, range of motion in flexion, the muscle density of anterior gluteus minimus in the affected side, and that of gluteus medius muscle in both affected and unaffected sides.

FINDINGS

Multiple regression analysis for step revealed that the muscle density of anterior gluteus minimus in the affected side and height were the independent predictors for step (R² = 0.389, p < 0.001). That for speed identified the muscle density of anterior gluteus minimus in the affected side as the only factor determining speed (R² = 0.287, p < 0.001).

INTERPRETATION

The fatty infiltration of anterior gluteus minimus muscle in affected side can be a predictor for the gait in in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

Sarcopenia Is Associated with an Increased Risk of Postoperative Complications Following Total Hip Arthroplasty for Osteoarthritis

Sarcopenia is a state of catabolic muscle wasting prevalent in geriatric patients. Likewise, osteoarthritis is an age-related musculoskeletal disease affecting patients with similar demographics. Late-stage hip osteoarthritis is often treated with total hip arthroplasty (THA). As sarcopenia influences the surgical outcomes, this study aimed to assess the impact of sarcopenia on the outcomes of THA. A 1:3 matched case-control study of sarcopenic to control patients was performed using a large national database. In total, 3992 patients were analyzed. Sarcopenic patients undergoing THA were more likely to experience dislocation (odds ratio (OR) = 2.19, 95% confidence interval (CI) 1.21-3.91) within 1 year of THA. Furthermore, sarcopenic patients had higher urinary tract infection rates (OR = 1.79, CI 1.32-2.42) and a greater risk of 90-day hospital readmission (hazard ratio (HR) = 1.39, CI 1.10-1.77). Sarcopenic patients experienced more falls (OR = 1.62, CI 1.10-2.39) and fragility fractures (OR = 1.77, CI 1.34-2.31). Similarly, sarcopenic patients had higher day of surgery costs (USD 13,534 vs. USD 10,504) and 90-day costs (USD 17,139 vs. USD 13,394) compared with the controls. Ultimately, sarcopenic patients undergoing THA experience higher rates of postoperative complications and incur greater medical costs. Given the potential risks, orthopedic surgeons may consider treating or reducing the severity of sarcopenia before surgery.

Risk factor investigation for hip dislocation after periacetabular tumour resection and endoprosthetic reconstruction via thin-slice CT-based 3D model

AIMS

Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation.

METHODS

A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables.

RESULTS

The dislocation rate was 13.9% (n = 17). The hip COR was found to be significantly shifted anteriorly and inferiorly in most patients in the dislocation group compared with the non-dislocation group. Three independent risk factors were found to be related to dislocation: resection of gluteus medius (odds ratio (OR) 3.68 (95% confidence interval (CI) 1.24 to 19.70); p = 0.039), vertical shift of COR > 18 mm (OR 24.8 (95% CI 6.23 to 128.00); p = 0.001), and sagittal shift of COR > 20 mm (OR 6.22 (95% CI 1.33 to 32.2); p = 0.026).

CONCLUSION

Among the 17 patients who dislocated, 70.3% (n = 12) were anterior dislocations. Three independent risk factors were identified, suggesting the importance of proper restoration of the COR and the role of the gluteus medius in maintaining hip joint stability.Cite this article: Bone Joint J 2022;104-B(10):1180-1188.

Asymptomatic gluteal tendinosis does not influence outcome in arthroscopic treatment of femoroacetabular impingement syndrome

PURPOSE

To compare outcomes after arthroscopy in FAIS patients with preoperative asymptomatic gluteal tendinosis (GT) to a control group with no gluteal tendinosis.

METHODS

A retrospective analysis was performed using data from FAIS patients who had arthroscopy between 2016 and 2018. Asymptomatic GT was diagnosed using hip MRI without clinical symptoms. Patients with asymptomatic GT were 1:1 propensity-score matched to patients without GT. Patient-reported outcomes (HOS-ADL, iHOT-12, mHHS), VAS scores, radiographic measures, performed procedures, complications, and revision surgery were compared and analyzed for both groups.

RESULTS

A total of 105 asymptomatic GT hips and 105 hips without GT were found using propensity-score matching. When compared to preoperative levels, both groups demonstrated significant improvements in PROs and VAS scores at the final follow-up. Besides, there were no significant differences in preoperative scores, final outcome scores, or score improvements between the groups. Patients in the GT group were significantly less likely to achieve the MCID for the VAS score (72.4% vs 83.8%, p = 0.045). However, there were no other differences in the rate of meeting the PASS and MCID between the study and the control groups.

CONCLUSION

It was demonstrated in this study that FAIS patients with asymptomatic gluteal tendinosis can expect to experience similar good short-term patients-reported outcomes as compared with patients without gluteal tendinosis.

LEVEL OF EVIDENCE

III.

Development of a clinical prediction rule to identify physical activity after total hip arthroplasty

OBJECTIVE

To develop clinical prediction rule (CPR) of physical activity at 1-year after total hip arthroplasty (THA).

DESIGN

Retrospective cohort study.

SETTING

University hospital with orthopedic surgery.

PARTICIPANTS

The study group included 321 patients (56 men) who underwent primary THA.

INTERVENTION

Not applicable.

MAIN OUTCOMES MEASURES

The data collected included age, body mass index, clinical score from the questionnaires, hip pain, range of motion, muscle strength, and Physical functions (10-Meter Walk Test, Timed Up and Go test and Sit-to-stand). Patients were classified into sufficient and insufficient activity groups based on their University of California, Los Angeles (UCLA) activity score 1 year after THA. Variables measured preoperatively and at 3 weeks postoperatively were analyzed using univariate and multivariate methods to derive CPR for physical activity.

RESULTS

A CPR was developed using the following five factors and cut-offs: age, ≤70.5 years; preoperative UCLA activity score, ≥3.5; preoperative hip abduction strength, ≥0.54 Nm/kg; preoperative knee extension strength, ≥1.04 Nm/kg; and 10-Meter Walk Test, ≤8.49 s at 3 weeks after surgery. The presence of four of the five factors predicted a sufficient physical activity level at 1-year, with a positive likelihood ratio of 5.94 and probability of 85.4%. The presence of five predictor variables increased the probability of sufficient physical activity after THA to 94.7%.

CONCLUSION

This study developed a CPR for physical activity at 1-year after THA. Having four or more of the five measurements were useful indicators for predicting of physical activity at 1 year postoperatively.

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.

Asymptomatic Gluteal Tendinopathies Negatively Impact Outcomes of Total Hip Arthroplasty: A Propensity Score-Matched Study

BACKGROUND

The purpose of this study is to compare outcomes after total hip arthroplasty (THA) in patients with preoperative asymptomatic gluteus medius and minimus (GMM) pathology to a control group with no GMM pathology.

METHODS

Patients undergoing THA for osteoarthritis between August 2012 and March 2018 were retrospectively reviewed. Asymptomatic GMM pathology was considered as the presence of gluteal tendinopathy diagnosed by magnetic resonance imaging (MRI) without the following clinical symptoms: Trendelenburg gait or test, abductor weakness, and lateral thigh tenderness. Patients with asymptomatic GMM pathology were matched (1:1) to patients without GMM pathology on MRI. Two-year data were collected on patient-reported outcomes including Harris Hip Score, Forgotten Joint Score, pain, and satisfaction. Postoperative clinical examination, radiographic measures, complications, and revisions for both groups were reviewed.

RESULTS

Fifty cases of asymptomatic GMM pathology were successfully matched to 50 hips without GMM pathology on MRI. Patients with asymptomatic GMM pathology demonstrated significantly worse outcomes regarding 2-year Harris Hip Score (86.24 vs 92.39, P = .04), VAS for pain (1.82 vs 0.98, P = .05), and patient satisfaction (7.69 vs 9.16, P = .002). The study group exhibited significantly higher rates of lateral hip pain postoperatively. Two cases (4%) in the control group underwent a revision THA and 4 cases (8%) in the study group underwent revision THA.

CONCLUSION

In patients undergoing THA for osteoarthritis, those with asymptomatic GMM pathology experience inferior 2-year postoperative patient-reported outcomes compared to a matched group. This finding should raise awareness surrounding this important pathology's negative impact on surgical outcomes, thus warranting increased vigilance, and possibly justifying concomitant treatment, even in cases of asymptomatic GMM tears.

LEVEL OF EVIDENCE

Level III - Retrospective comparative prognostic study.