Risk Factors for Iliopsoas Tendinopathy After Anterior Approach Total Hip Arthroplasty

Evaluation of Clinical Tests to Diagnose Iliopsoas Tendinopathy

BACKGROUND

Diagnosing iliopsoas tendinopathy is challenging because of nonspecific pain patterns and clinical signs overlapping with those of other hip conditions. Although peritendinous anesthetic injections provide the best diagnostic accuracy, they are invasive and resource intensive. Conventional clinical tests largely focus on hip flexion, potentially overlooking the diagnostic contribution of the muscle's secondary function-external rotation. A newly described hip-external rotation-flexion-ceiling (HEC) test combines the primary function (hip flexion) with the secondary function (external rotation) of the iliopsoas, potentially offering enhanced diagnostic reliability.

QUESTIONS/PURPOSES

This study aimed to (1) determine the diagnostic accuracy of the HEC test and 10 conventional physical examination tests for iliopsoas-related groin pain; (2) detect "good" and "poor" tests for diagnosing iliopsoas tendinopathy based on three diagnostic performance criteria before and after anesthetic injection (mean pain reduction, optimal cutoff value for pain reduction, and area under the curve [AUC]); and (3) rank all tests, based on the same criteria, to identify the best diagnostic tool.

METHODS

In this retrospective study at a high-volume arthroplasty community hospital, we reviewed 48 consecutive fluoroscopy-guided iliopsoas tendon injections performed for persistent groin pain between October 2023 and May 2024. After excluding four patients without any data on the clinical tests performed, a population of 44 participants (mean age 48 ± 15 years; 34% male) remained, which included both native hips (52%) and patients who had undergone THA (48%). Eleven clinical tests-including the novel HEC test and 10 conventional tests (such as resisted hip flexion seated and straight leg raise [SLR] in neutral and external rotation)-were performed before and after a fluoroscopy-guided iliopsoas injection, with an improvement in their characteristic groin pain serving as the diagnostic gold standard. A test was considered "good" if it met all three criteria: (1) a significant mean VAS pain score reduction of ≥ 3 points after injection, (2) a significant optimal cutoff value for pain reduction of ≥ 4, and (3) a significant AUC of ≥ 0.80. A test meeting none of these three criteria was considered "poor." Using the same three criteria, each clinical test with at least 30 valid observations received a ranking position for each criterion, and these three ranks were summed to produce a total score. The test with the lowest total score was deemed the best, followed by the tests with higher scores. Statistical analysis involved estimating sensitivity, specificity, AUC, and optimal cutoff values using receiver operating characteristic curves and the Youden J statistic.

RESULTS

In 82% (36 of 44) of patients who experienced pain reduction after injection and who were diagnosed with iliopsoas tendinopathy, the following tests had the most clinically important pain reduction after infiltration: the HEC test (6.0 ± 2.1; p < 0.001), resisted hip flexion (seated) (5.1 ± 1.3; p < 0.001), and SLR in exorotation (4.9 ± 1.4; p < 0.001). The HEC test demonstrated a sensitivity of 94%, specificity of 88%, and an AUC of 0.99, with a high cutoff (VAS score reduction of 5) outperforming conventional tests. Three tests-including the HEC test, resisted hip flexion (seated), and resisted hip external rotation (seated)-met all three criteria to be classified as "good" tests, whereas the Thomas test, SLR in neutral, and the snapping hip test were deemed "poor" tests. The HEC test was ranked best to detect iliopsoas tendinopathy, followed by the resisted hip flexion (seated), SLR in exorotation, and resisted hip external rotation (seated).

CONCLUSION

The HEC test is an accurate diagnostic maneuver for iliopsoas tendinopathy offering improved sensitivity and specificity compared with conventional tests. Surgeons should consider incorporating the HEC test into routine evaluations of patients with groin pain to enhance diagnostic precision and optimize treatment strategies. Future studies should focus on interobserver reliability and assess the test's performance across diverse patient populations.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Outcomes of Nonoperative Versus Operative Treatment of Iliopsoas Impingement After Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Iliopsoas impingement (IPI) is a rare cause of persistent groin pain after primary total hip arthroplasty (THA). Treatment options include conservative management such as corticosteroid injections into the tendon sheath, iliopsoas tenotomy, and acetabular revision. The purpose of this systematic review is to compare outcomes of nonoperative versus operative treatment options for IPI after THA by assessing symptom resolution rate, patient-reported outcomes (PROs), complications, and revision surgery rate.

METHODS

A systematic review following guidelines established by the Preferred Reporting Items for Systematic Reviews and Meta-analyses was performed in the PubMed, Embase, and Cochrane Library databases regarding IPI after THA. Studies were categorized based on the specific treatment modality: conservative treatment (corticosteroid injections), iliopsoas tenotomy, or acetabular revision. There were six studies (151 patients) that evaluated conservative treatment, 21 studies (452 patients) that evaluated iliopsoas tenotomy, and five studies (103 patients) that evaluated acetabular revision as treatment options for IPI after THA.

RESULTS

The mean pre-operative to postoperative Harris Hip Scores (HHS) for the three groups were 64.8 to 78.6 (P = 0.03), 54.9 to 83.1 (P < 0.00001), and 56 to 82.4 (P < 0.00001), respectively. Persistent IPI symptoms were noted in 53.6% (conservative), 17.8% (iliopsoas tenotomy), and 12.6% (acetabular revision) of patients. The complication rate for surgical treatment was 2.3% in the iliopsoas tenotomy group and 15.7% in the acetabular revision group. Revision surgery or additional surgical intervention was required by 16.4% (conservative), 4.5% (iliopsoas tenotomy), and 3.9% (acetabular revision) of patients.

CONCLUSION

Nonoperative management of IPI after THA may fail to provide long-term resolution of symptoms. While iliopsoas tenotomy and acetabular revision both effectively treat IPI after THA, tenotomy has a significantly lower complication rate compared to acetabular revision. Thorough patient counseling is critical when discussing surgical treatment options for persistent symptomatic IPI after THA.

LEVEL OF EVIDENCE

IV.

Safety and outcomes of bikini-incision DAA for hip arthroplasty with large acetabular cups (≥56 mm): A single-surgeon series of 215 cases

INTRODUCTION

This study evaluates complications associated with the bikini-incision direct anterior approach (DAA) total hip arthroplasty (THA) performed by a single surgeon on a standard operating table, with a focus on cases requiring large acetabular cups (≥56 mm). Secondary objectives include assessing clinical outcomes and implant survivorship.

METHODS

A retrospective analysis was conducted on primary bikini-incision DAA THAs performed by a single surgeon between 2013 and 2024. Cases involving acetabular cups ≥56 mm were included, while emergency hip fracture cases and those requiring posterolateral approaches were excluded. Clinical data, radiographs, and Kaplan-Meier survival analysis were used to assess complications, Harris Hip Scores (HHS), and implant survivorship.

RESULTS

This study included 215 THA procedures performed on 210 male patients (mean age 67 years, BMI 28.6), with an average follow-up of 3.9 years. The primary indication was osteoarthritis (88.4%). The mean preoperative HHS was 41.8, which significantly improved to 92.6 postoperatively (p < 0.001). Complications included lateral femoral cutaneous nerve (LFCN) neuropraxia (2.3%), periprosthetic fractures (0.93%), and femoral stem subsidence (0.93%). The revision rate was 0.93%, with Kaplan-Meier analysis indicating a 99% survival rate for the stem and 100% survival for the acetabular cup at the final follow-up.

DISCUSSION

The bikini-incision DAA THA using a standard operating table provides excellent short- to mid-term functional outcomes and implant survivorship for patients requiring large acetabular cups (≥56 mm). The approach is associated with low complication and revision rates, supporting its safety and efficacy in this cohort.

4-year clinical outcomes of anterior acetabular wall reconstruction and cup revision for treatment of anterior acetabular wall defects with iliopsoas tendinopathy following total hip arthroplasty

Purpose:

To assess clinical and radiographic outcomes of anterior acetabular wall reconstruction and cup revision in patients with anterior acetabular wall defects and associated iliopsoas tendinopathy (IPT) following total hip arthroplasty (THA).

Methods:

7 patients with IPT (defined as groin pain that increased with active hip flexion) and pre-revision computed tomography (CT) scans showing anterior acetabular wall defects and cup-iliopsoas impingement were included. During cup revision, an autologous biconvex iliac crest graft was harvested and placed over the anterior acetabular wall defect before press-fitting a revision cup. Cup inclination and anteversion, axial and sagittal cup overhang, and iliopsoas muscle strength (0–5) were evaluated pre- and post-revision. Forgotten joint score (FJS; 0–100), Oxford hip score (OHS; 0–48), hip pain (0–10), satisfaction (0–10), graft osseointegration and resorption were evaluated post-revision.

Results:

Pre-revision cup inclination was 43.7 ± 9.4°, anteversion was 30.4 ± 10.5°, axial overhang was 6.6 ± 7.9 mm, and sagittal overhang was 14.2 ± 4.8 mm. Immediate post-revision cup anteversion was 33.0 ± 7.9°, inclination was 45.3 ± 5.1°, while there was no axial or sagittal overhang. At 60.3 ± 5.6 (52–70) months follow-up, 6 of 7 patients were available for assessment (1 patient had died). Iliopsoas muscle strength increased from 3.9 ± 0.7 to 4.6 ± 0.9, FJS was 77.5 ± 32.8, OHS was 40.3 ± 12.8, hip pain on VAS was 0.2 ± 0.4 at rest and 2.3 ± 2.6 during activities. Patient satisfaction with surgery was 8.3 ± 2.3, but 1 patient was dissatisfied and reported persistent hip pain. Last follow-up CT scans were available for 4 of 7 patients, with 3 showing osseointegrated grafts and no graft resorption.

Conclusions:

Anterior acetabular wall reconstruction and cup revision resulted in satisfactory clinical outcomes at a minimum follow-up of 4 years in 5 of 7 cases. Most patients fully recovered their iliopsoas muscle strength, had minimal to no pain, excellent FJS, and an osseointegrated acetabular wall graft.

Endoscopic Iliopsoas Fractional Lengthening as a Treatment for Refractory Iliopsoas Impingement After Total Hip Arthroplasty Shows Favorable Functional Outcomes With No Impact on Range of Motion

PURPOSE

To report the minimum 2-year clinical outcomes of endoscopic iliopsoas fractional lengthening (IFL) in patients with recalcitrant iliopsoas tendinitis after total hip arthroplasty (THA).

METHODS

Data were prospectively collected from 2014 to 2020 for patients who underwent IFL after primary THA as part of our institutional hip outcomes registry. Patients were included if they had completed the following patient-reported outcomes preoperatively and at minimum 2-year follow-up: modified Harris Hip Score and visual analog scale score. Preoperative and postoperative data were available for the International Hip Outcome Tool 12 score, and patient satisfaction was analyzed. Patients included in the study reported irritation of the iliopsoas tendon after cementless THA, refractory to conservative treatment methods. IFL was recommended after a workup that included ruling out infection and aseptic loosening, as well as a positive response to an iliopsoas guided diagnostic injection.

RESULTS

Seventeen patients were included in the study. The mean age at IFL was 56.42 years (range, 30.17-81.29 years). The mean interval between THA and IFL was 2.72 years (range, 0.25-8.34 years). There was a significant improvement in all evaluated patient-reported outcomes, and a high percentage of patients met the minimal clinically important difference for the modified Harris Hip Score (14, 82.35%), International Hip Outcome Tool 12 score (11, 91.66.00%), and visual analog scale score (16, 94.12%) (P < .05). Furthermore, 15 patients (88.2%) reported a positive response to the patient acceptable symptom state anchor question. No impact on preoperative versus postoperative active range of motion was observed, and no patient reported weakness at the latest follow-up (P > .05). Preoperative flexion was 106.33° (range, 85.0°-120.0°), and postoperative flexion was 106° (range, 90°-120°).

CONCLUSIONS

Endoscopic IFL yielded significant improvements in functional outcomes with high patient satisfaction at minimum 2-year follow-up, with no reported complications. This procedure did not have a significant negative impact on hip range of motion.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Hip Flexor Muscle Activation During Common Rehabilitation and Strength Exercises

Background/Objectives: The iliopsoas muscle plays an essential role in lumbopelvic and hip anterior stability, which is particularly important in the presence of limited osseous acetabular coverage anteriorly as in hip dysplasia and/or hip micro-instability. The purpose of this systematic review is to (1) describe iliopsoas activation levels during common rehabilitation exercises and (2) provide an evidence-based exercise progression for strengthening the iliopsoas based on electromyography (EMG) studies. Methods: In total, 109 healthy adult participants ranging from ages 20 to 40 were included in nine studies. PubMed, CINAHL, and Embase databases were systematically searched for EMG studies of the psoas, iliacus, or combined iliopsoas during specific exercise. The Modified Downs and Black Checklist was used to perform a risk of bias assessment. PROSPERO guidelines were followed. Results: Nine studies were included. Findings suggest that the iliopsoas is increasingly activated in ranges of hip flexion of 30-60°, particularly with leg lowering/raising exercises. Briefly, >60% MVIC activity of the iliopsoas was reported in the active straight leg raise (ASLR) in ranges around 60° of hip flexion, as well as with supine hip flexion and leg lifts. In total, 40-60% MVIC was found in exercises including the mid-range of the ASLR around 45° of hip flexion and lifting a straight trunk while in a hip flexed position. Conclusions: The findings suggest that exercises in increased hip flexion provide greater activation of the iliopsoas compared to exercises where the trunk is moving on the lower extremity. Iliopsoas activation can be incrementally progressed from closed to open kinetic chain exercises, and eventually to the addition of external loads. The proposed exercise program interprets the results and offers immediate translation into clinical practice.

Patient-reported outcomes in total hip arthroplasty for patients with anatomically contoured femoral heads

INTRODUCTION

Iliopsoas tendinitis after total hip arthroplasty (THA) has become more prevalent with the increased use of large-diameter femoral heads impinging on native surrounding tissues. Anatomically contoured heads (ACH) are soft-tissue-friendly femoral heads created to minimise this issue. This retrospective study assesses iliopsoas tendinitis prevalence and re-operations in primary THAs with ACH, while determining the minimal clinically important difference (MCID) achievement and improvement with 5 patient-reported outcome measures (PROMs).

METHODS

We conducted a retrospective analysis of 53 ACHs from January 2020 to July 2023. Patients who completed Hip Injury and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF SF-10a), PROMIS Global Health (GH)-Mental, or PROMIS GH-Physical, and pain score questionnaires were identified. PROM scores were collected preoperatively and at 3-month and 1-year postoperative intervals. Comparisons using chi-square and ANOVA tests were applied.

RESULTS

The rates of achieving MCID and improvement within the first year were (69.2 vs. 76.9%) for PROMIS GH-Physical, (38.5 vs. 46.2%) for PROMIS GH-Mental, (71.4 vs. 92.9%) for HOOS-PS, (80.0 vs. 80.0%) for PROMIS PF SF-10a, and (74.0 vs. 91.7%) for pain scores. PROM scores at 3 months and 1 year significantly varied across all categories, except for PROMIS GH-Mental. No patients had iliopsoas tendinitis, dislocations, or re-operations.

DISCUSSION

ACH implants may alleviate anterior hip pain, while maintaining comparable strength and bio-compatibility to conventional femoral heads. This study underscores the early safety and potential of ACH implants in reducing iliopsoas tendinitis and impingement.

Can Patients Who Have Low-Grade Hip Osteoarthritis Expect the Same Outcome After Total Hip Arthroplasty Compared to Those Who Have End-Stage Osteoarthritis? - A Matched Case-Control Study

BACKGROUND

Total hip arthroplasty (THA) is an effective procedure for patients with end-stage hip osteoarthritis (OA). In addition, when hip preservation surgery is no longer indicated due to the presence of early or mild arthritic changes, THA can also be considered. Whether these patients can expect the same outcome after THA as patients who have end-stage OA remains unclear. The goal of this study was to compare the clinical outcomes after THA of patients who have low-grade OA versus a matched cohort with end-stage OA.

METHODS

This is a retrospective, single-center, multisurgeon case-control study in a high-volume referral center. Based on a cohort of 2,189 primary anterior approach THAs (1,815 patients), 50 low-grade OA cases were matched 1:1 by age, sex, and body mass index to 50 controls who have end-stage OA. Patient-reported outcome measures (PROMs) were Hip Disability and Osteoarthritis Outcome Scores and Short Form-36.

RESULTS

No significant differences in preoperative PROMs between low-grade and end-stage OA patients were found, except for 36-item Short Form Survey pain (33.0 versus 41.0; P = .045). In both groups a significant improvement of all PROMs was found postoperatively. However, all Hip Disability and Osteoarthritis Outcome Scores were significantly lower in the low-grade OA group compared to the end-stage OA group. In the group with low-grade OA, a significantly lower percentage of patients achieved the minimal clinically important difference and substantial clinical benefit after THA compared to the group with end-stage OA.

CONCLUSIONS

Patients who have low-grade OA can expect substantial clinical improvement after THA. However, the improvement is lower compared to patients who have end-stage OA. A thorough understanding of the factors that may lead to inferior clinical outcomes is imperative to improving the indications for THA in individuals who have low-grade OA.

Comparison of iliopsoas tendonitis after hip resurfacing arthroplasty and total hip arthroplasty: A case-controlled investigation using a validated simulation

Iliopsoas tendonitis, typically caused by impingement with the acetabular cup, occurs in up to 18% of patients after total hip arthroplasty (THA) and up to 30% of patients after hip resurfacing arthroplasty (HRA). We have developed a simulation for detecting iliopsoas impingement and validated it in a previous study of THA patients. However, due to the difference in incidence between HRA and THA, this study had two aims. First, to validate the simulation in a cohort of HRA patients and, second, to comparethe results of the HRA and THA patients to understand any differences in their etiology. We conducted a retrospective search in an experienced surgeon's database for HRA patients with iliopsoas tendonitisand control patients without iliopsoas tendonitis, resulting in two cohorts of 12 patients. Using CT scans, 3D models of the each patient's prosthetic and bony anatomy were generated, landmarked, and simulated. Regarding validation of the simulation for HRA patients, impingement significantly predicted the probability of iliopsoas tendonitis in logistic regression models and the simulation had a sensitivity of 83%, specificity of 100%, and an AUC ROC curve of 0.95. Unexpectedly, the HRA cohort exhibited less impingement than the THA cohort. Our novel simulation has now been demonstrated to detect iliopsoas impingement and differentiate between the symptomatic and asymptomatic cohorts in investigations of THA and HRA patients. This tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis.

Satisfactory mid-term clinical outcomes of endoscopic tenotomy for iliopsoas tendinopathy following total hip arthroplasty

PURPOSE

To report 5-year outcomes of endoscopic iliopsoas tenotomy in patients with iliopsoas tendinopathy following total hip arthroplasty (THA) and determine whether clinical scores are associated with cup position.

METHODS

Patients who underwent endoscopic iliopsoas tenotomy for iliopsoas tendinopathy following THA (2014-2017) were contacted. Indications for endoscopic iliopsoas tenotomy after THA were groin pain during active hip flexion, exclusion of other causes of groin pain, and no pain relief after 6 months of conservative treatment. Pretenotomy cup inclination and anteversion were measured on radiographs; axial and sagittal cup overhang were measured on computed tomography (CT) scans. Oxford hip score (OHS), modified Harris hip score (mHHS), and groin pain were assessed.

RESULTS

The initial cohort comprised 16 men (17 hips) and 31 women (32 hips), aged 60.7 ± 10.6 years. Cup inclination and anteversion were, respectively, 46.2 ± 6.2° and 14.6 ± 8.4°, while axial and sagittal cup overhang were, respectively, 4.4 ± 4.0 mm and 6.9 ± 4.5 mm. At ≥5 years follow-up, four hips underwent cup and stem revision, two underwent isolated cup revision and one underwent secondary iliopsoas tenotomy. OHS improved by 23 ± 10 and mHHS improved by 31 ± 16. Posttenotomy groin pain was slight in 20.0%, mild in 17.5% and moderate in 12.5%. Regression analyses revealed that net change in mHHS decreased with sagittal cup overhang (β = -3.1; 95% confidence interval [CI] = -4.6 to -1.7; p < 0.001), but that there were no associations between cup position and net change in OHS.

CONCLUSIONS

Endoscopic iliopsoas tenotomy provides good mid-term clinical outcomes in patients with iliopsoas tendinopathy following THA. Furthermore, improvements in mHHS were found to decrease with increasing sagittal cup overhang, in cases for which adequate preoperative imaging was available.

LEVEL OF EVIDENCE

Level IV.

High-resolution ultrasound in the evaluation of the adult hip

This paper reviews ultrasound of the hip, which is a commonly requested examination for symptomatic hip issues. This includes both intra-articular and extra-articular causes of hip pain. Ultrasound is easily accessible, lacks radiation exposure, and allows for evaluation of the contralateral hip as well as assessment of dynamic maneuvers. Ultrasound can be used to guide interventional procedures. Ultrasound of the hip can be challenging due to the deep location of structures and complex anatomy. Typically, high-frequency transducers are used to examine the hip, however the choice of ultrasound transducer depends on the patient's body habitus, with lower frequency transducers required to penetrate deep structures in obese patients. It is important to have an approach to ultrasound of the hip which includes assessment of the anterior, lateral, posterior, and medial aspects of the hip. The technique and relevant anatomy of each of these compartments are discussed as well as the use of Doppler examination of the hip. Several dynamic maneuvers can be performed to help determine the cause of hip pathology in various locations, and these are described and illustrated. Ultrasound is useful for guided procedures about the hip, and these indications will be reviewed.