To 200,000 m/z and Beyond: Native Electron Capture Charge Reduction Mass Spectrometry Deconvolves Heterogeneous Signals in Large Biopharmaceutical Analytes.

Great progress has been made in the detection of large biomolecular analytes by native mass spectrometry; however, characterizing highly heterogeneous samples remains challenging due to the presence of many overlapping signals from complex ion distributions. Electron-capture charge reduction (ECCR), in which a protein cation captures free electrons without apparent dissociation, can separate overlapping signals by shifting the ions to lower charge states. The concomitant shift to higher m/z also facilitates the exploration of instrument upper m/z limits if large complexes are used. Here we perform native ECCR on the bacterial chaperonin GroEL and megadalton scale adeno-associated virus (AAV) capsid assemblies on a Q Exactive UHMR mass spectrometer. Charge reduction of AAV8 capsids by up to 90% pushes signals well above 100,000 m/z and enables charge state resolution and mean mass determination of these highly heterogeneous samples, even for capsids loaded with genetic cargo. With minor instrument modifications, the UHMR instrument can detect charge-reduced ion signals beyond 200,000 m/z. This work demonstrates the utility of ECCR for deconvolving heterogeneous signals in native mass spectrometry and presents the highest m/z signals ever recorded on an Orbitrap instrument, opening up the use of Orbitrap native mass spectrometry for heavier analytes than ever before.

Reliability and responsiveness of the Swedish short Hip-RSI.

Purpose: The aim of this study was to examine test-retest reliability and responsiveness of the short version (6-item) Hip Return to Sport after Injury (Hip-RSI) scale in patients following hip arthroscopy. Methods: The study included 100 hip arthroscopy patients responding to a digital survey including the short version (6-item) Hip-RSI, International Hip Outcome Tool (short version) (iHOT-12) and RTS status 3, 6 and 9 months following surgery. The Hip-RSI was administered twice at 3-month follow-up. Test-retest reliability was evaluated using intraclass correlation coefficients. Responsiveness was tested by correlations between changes in Hip-RSI and iHOT-12 scores and by comparing change in Hip-RSI scores of patients who progressed on the return to sport (RTS) continuum (from return to any sport to return to performance) to patients who did not, using independent samples t-tests. Results: Hip-RSI was found to have excellent test-retest reliability on the individual (intraclass correlation coefficient, ICC [95% confidence interval, CI]: 0.90 [0.83-0.94]) and group level (ICC [95% CI]: 0.95 [0.91-0.97]) with a standard error of measurement of 5.53 and smallest detectable change of 15.3 on the individual and 2.2 on the group level. Hip-RSI was found responsive to change through positive correlations of changes in scores with changes in iHOT-12 scores from 3 to 6 months (r [95% CI]: 0.51 [0.35-0.65]; p < 0.001) and from 3 to 9 months following arthroscopy (r [95% CI]: 0.61 [0.57-0.79); p < 0.001). Further responsiveness was shown by significant mean changes in scores among patients that progressed on the RTS-continuum (3-6 months: 8.6 [95% CI: 3.8- 13.5); 3-9 months: 12.6 [5.6-19.7]). Conclusion: The short version (6-item) Hip-RSI demonstrated excellent test-retest reliability and responsiveness to change in the evaluation of psychological readiness to RTS following hip arthroscopy. Level of Evidence: Level II.

Weaker Quadriceps Muscle Strength With a Quadriceps Tendon Graft Compared With a Patellar or Hamstring Tendon Graft at 7 Months After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Impaired quadriceps muscle strength after anterior cruciate ligament reconstruction (ACLR) is associated with worse clinical outcomes and a risk of reinjuries. Yet, we know little about quadriceps muscle strength in patients reconstructed with a quadriceps tendon (QT) graft, which is increasing in popularity worldwide. PURPOSE: To describe and compare isokinetic quadriceps strength in patients undergoing ACLR with a QT, hamstring tendon (HT), or bone-patellar tendon-bone (BPTB) autograft. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We included patients with QT grafts (n = 104) and matched them to patients with HT (n = 104) and BPTB (n = 104) grafts based on age, sex, and associated meniscal surgery. Data were collected through clinical strength testing at a mean of 7 ± 1 months postoperatively. Isokinetic strength was measured at 90 deg/s, and quadriceps strength was expressed as the limb symmetry index (LSI) for peak torque, total work, torque at 30° of knee flexion, and time to peak torque. RESULTS: Patients with QT grafts had the most impaired isokinetic quadriceps strength, with the LSI ranging between 67.5% and 75.1%, followed by those with BPTB grafts (74.4%-81.5%) and HT grafts (84.0%-89.0%). Patients with QT grafts had a significantly lower LSI for all variables compared with patients with HT grafts (mean difference: peak torque: -17.4% [95% CI, -21.7 to -13.2], P < .001; total work: -15.9% [95% CI, -20.6 to -11.1], P < .001; torque at 30° of knee flexion: -8.8% [95% CI, -14.7 to -2.9], P = .001; time to peak torque: -17.7% [95% CI, -25.8 to -9.6], P < .001). Compared with patients with BPTB grafts, patients with QT grafts had a significantly lower LSI for all variables (mean difference: peak torque: -6.9% [95% CI, -11.2 to -2.7], P < .001; total work: -7.7% [95% CI, -12.4 to -2.9], P < .001; torque at 30° of knee flexion: -6.3% [95% CI, -12.2 to -0.5], P = .03; time to peak torque: -8.8% [95% CI, -16.9 to -0.7], P = .03). None of the graft groups reached a mean LSI of >90% for peak torque (QT: 67.5% [95% CI, 64.8-70.1]; HT: 84.9% [95% CI, 82.4-87.4]; BPTB: 74.4% [95% CI, 72.0-76.9]). CONCLUSION: At 7 months after ACLR, patients with QT grafts had significantly worse isokinetic quadriceps strength than patients with HT and BPTB grafts. None of the 3 graft groups reached a mean LSI of >90% in quadriceps strength.

Assessment of genome packaging in AAVs using Orbitrap-based charge-detection mass spectrometry.

Adeno-associated viruses (AAVs) represent important gene therapy vectors with several approved clinical applications and numerous more in clinical trials. Genome packaging is an essential step in the bioprocessing of AAVs and needs to be tightly monitored to ensure the proper delivery of transgenes and the production of effective drugs. Current methods to monitor genome packaging have limited sensitivity, a high demand on labor, and struggle to distinguish between packaging of the intended genome or unwanted side-products. Here we show that Orbitrap-based charge-detection mass spectrometry allows the very sensitive quantification of all these different AAV bioprocessing products. A protocol is presented that allows the quantification of genome-packed AAV preparations in under half an hour, requiring only micro-liter quantities of typical AAV preparations with ∼1013 viral capsids per milliliter. The method quickly assesses the integrity and amount of genome packed AAV particles to support AAV bioprocessing and characterization of this rapidly emerging class of advanced drug therapies.

Rapid decline of yearly number of hip arthroscopies in Sweden: a retrospective time series of 6,105 hip arthroscopies based on a national patient data register.

Background and purpose - Hip arthroscopies (HAs) have increased exponentially worldwide and are expected to continue rising. We describe time trends in HA procedures in Sweden (10 million inhabitants) between 2006 and 2018 with a focus on procedure rates, surgical procedures, and patient demographics such as age and sex distribution.Patients and methods - We retrospectively collected data from the Swedish National Patient Register (NPR) for all surgeries including surgical treatment codes considered relevant for HA from 2006 to 2018. Surgical codes were validated through a multiple-step procedure and classified into femoroacetabular impingement syndrome (FAIS) related or non-FAIS related procedure. Frequencies, sex differences, and time trends of surgical procedures and patient demographics are presented.Results - After validation of HA codes, 6,105 individual procedures, performed in 4,924 patients (mean age 34 years [SD 12]) were confirmed HAs and included in the analysis. Yearly HA procedure rates increased from 15 in 2006 to 884 in 2014, after which a steady decline was observed with 469 procedures in 2018. The majority (65%) of HAs was performed in males. Male patients were younger, and surgeries on males more frequently included an FAIS-related procedure.Interpretation - Similar to previous studies in other parts of the world, we found dramatic increases in HA procedures in Sweden between 2006 and 2014. Contrary to existing predictions, HA rates declined steadily after 2014, which may be explained by more restrictive patient selection based on refined surgical indications, increasing evidence, and clinical experience with the procedure.

Improvements After Arthroscopic Treatment for Femoroacetabular Impingement Syndrome in High-Level Ice Hockey Players: 2-Year Outcomes by Player Position.

BACKGROUND: Ice hockey players often undergo arthroscopic treatment for femoroacetabular impingement syndrome (FAIS); however, only a few studies have reported postoperative patient-reported outcomes. It has been debated whether player position is related to FAIS. PURPOSE: To evaluate the change in patient-reported outcome measures (PROMs) in high-level ice hockey players from presurgery to 2 years after arthroscopic treatment for FAIS. The secondary aim was to evaluate differences in outcomes among player positions and whether stick handedness is related to the side of the symptomatic hip. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Ice hockey players undergoing treatment for FAIS between 2011 and 2019 were prospectively included. Preoperative and 2-year follow-up scores were collected for the following PROMs: HAGOS (Copenhagen Hip and Groin Outcome Score), iHOT-12 (12-item International Hip Outcome Tool), EQ-5D (EuroQol-5 Dimensions) and EQ-VAS (EuroQol-Visual Analog Scale), Hip Sports Activity Scale, and visual analog scale for overall hip function. Player position and stick handedness were collected from public sources. Preoperative and follow-up outcomes were compared for the entire cohort and among player positions. RESULTS: The cohort included 172 ice hockey players with a mean age of 28 years, a mean body mass index of 25.6, and a mean symptom duration of 46.3 months. In the 120 players with 2-year follow-up data, there was significant improvement in all PROMs as compared with presurgery: HAGOS subscales (symptoms, 47.5 vs 68.0; pain, 57.0 vs 75.8; activities of daily living, 62.5 vs 81.0; sports, 40.0 vs 64.7; physical activity, 30.9 vs 57.2; quality of life, 32.5 vs 57.8), iHOT-12 (45.2 vs 66.7), EQ-5D (0.59 vs 0.75), EQ-VAS (68.3 vs 73.2), and visual analog scale for overall hip function (49.6 vs 69.2) (P < .0001 for all). At 2-year follow-up, 83% reported satisfaction with the procedure. There was no difference in the improvement in PROMs among player positions. Further, there was no significant relationship between stick handedness and side of symptomatic hip; however, because of the number of bilateral procedures and large number of left-handed shooters, no conclusions could be drawn. CONCLUSION: High-level ice hockey players undergoing arthroscopic treatment for FAIS reported improvements in PROMs 2 years after surgery, regardless of player position.

Adeno-associated virus capsid assembly is divergent and stochastic.

Adeno-associated viruses (AAVs) are increasingly used as gene therapy vectors. AAVs package their genome in a non-enveloped T = 1 icosahedral capsid of ~3.8 megaDalton, consisting of 60 subunits of 3 distinct viral proteins (VPs), which vary only in their N-terminus. While all three VPs play a role in cell-entry and transduction, their precise stoichiometry and structural organization in the capsid has remained elusive. Here we investigate the composition of several AAV serotypes by high-resolution native mass spectrometry. Our data reveal that the capsids assemble stochastically, leading to a highly heterogeneous population of capsids of variable composition, whereby even the single-most abundant VP stoichiometry represents only a small percentage of the total AAV population. We estimate that virtually every AAV capsid in a particular preparation has a unique composition. The systematic scoring of the simulations against experimental native MS data offers a sensitive new method to characterize these therapeutically important heterogeneous capsids.

Psychological readiness is related to return to sport following hip arthroscopy and can be assessed by the Hip-Return to Sport after Injury scale (Hip-RSI).

PURPOSE: Psychological readiness may play an important role in the return to sport (RTS) process following hip arthroscopy (HA), but there are limited tools for the measurement of this construct. The aim of this study was to modify the Swedish version of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale for use in HA patients and evaluate its psychometric properties. METHODS: Content validity of a modified version of the Swedish ACL-RSI (Hip-RSI) was evaluated through 127 HA patient responses and relevance ratings by an expert panel (35 patients, 9 surgeons, 11 physiotherapists). Items with low relevance were omitted. Construct validity was assessed by the association of Hip-RSI scores to hip-related sporting function (HAGOS sport) and quality of life (iHOT12). Hip-RSI scores were compared between patients who had not returned, or returned to sport participation, previous sport, and sport performance. RESULTS: Item reduction resulted in a 6-item Hip-RSI scale with adequate content validity for the target population. Construct validity of the full and the item-reduced scale was demonstrated by correlation to HAGOS sport and iHOT12 (r 0.631-0.752). A gradient increase in Hip-RSI scores was found for patients returning to sport participation, previous sport, and sport performance. CONCLUSION: The short version of the Swedish Hip-RSI is a valid tool for the assessment of psychological readiness to RTS and can be recommended to be used in HA patients. Higher psychological readiness to RTS, assessed by the Hip-RSI, is found with increasing levels of return to sports following HA. LEVEL OF EVIDENCE: III.

Mild Acid Elution and MHC Immunoaffinity Chromatography Reveal Similar Albeit Not Identical Profiles of the HLA Class I Immunopeptidome.

To understand and treat immunology-related diseases, a comprehensive, unbiased characterization of major histocompatibility complex (MHC) peptide ligands is of key importance. Preceding the analysis by mass spectrometry, MHC class I peptide ligands are typically isolated by MHC immunoaffinity chromatography (MHC-IAC) and less often by mild acid elution (MAE). MAE may provide a cheap alternative to MHC-IAC for suspension cells but has been hampered by the high number of contaminating, MHC-unrelated peptides. Here, we optimized MAE, yielding MHC peptide ligand purities of more than 80%. When compared with MHC-IAC, obtained peptides were similar in numbers, identities, and to a large extent intensities, while the percentage of cysteinylated peptides was 5 times higher in MAE. The latter benefitted the discovery of MHC-allotype-specific, distinct cysteinylation frequencies at individual positions of MHC peptide ligands. MAE revealed many MHC ligands with unmodified, N-terminal cysteine residues which get lost in MHC-IAC workflows. The results support the idea that MAE might be particularly valuable for the high-confidence analysis of post-translational modifications by avoiding the exposure of the investigated peptides to enzymes and reactive molecules in the cell lysate. Our improved and carefully documented MAE workflow represents a high-quality, cost-effective alternative to MHC-IAC for suspension cells.

Resolving heterogeneous macromolecular assemblies by Orbitrap-based single-particle charge detection mass spectrometry.

We demonstrate single-particle charge detection mass spectrometry on an Orbitrap for the analysis of megadalton biomolecular assemblies. We establish that the signal amplitudes of individual ions scale linearly with their charge, which can be used to resolve mixed ion populations, determine charge states and thus also determine the masses of individual ions. This enables the ultrasensitive analysis of heterogeneous protein assemblies including immunoglobulin oligomers, ribosomes, proteinaceous nanocontainers and genome-packed adeno-associated viruses.

Site-specific functionality and tryptophan mimicry of lipidation in tetraspanin CD9.

Lipidation of transmembrane proteins regulates many cellular activities, including signal transduction, cell-cell communication, and membrane trafficking. However, how lipidation at different sites in a membrane protein affects structure and function remains elusive. Here, using native mass spectrometry we determined that wild-type human tetraspanins CD9 and CD81 exhibit nonstochastic distributions of bound acyl chains. We revealed CD9 lipidation at its three most frequent lipidated sites suffices for EWI-F binding, while cysteine-to-alanine CD9 mutations markedly reduced binding of EWI-F. EWI-F binding by CD9 was rescued by mutating all or, albeit to a lesser extent, only the three most frequently lipidated sites into tryptophans. These mutations did not affect the nanoscale distribution of CD9 in cell membranes, as shown by super-resolution microscopy using a CD9-specific nanobody. Thus, these data demonstrate site-specific, possibly conformation-dependent, functionality of lipidation in tetraspanin CD9 and identify tryptophan mimicry as a possible biochemical approach to study site-specific transmembrane-protein lipidation.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018.

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

High prevalence of hip and groin problems in professional ice hockey players, regardless of playing position.

PURPOSE: The prevalence of hip and groin problems in professional male ice hockey is unknown and suspected to differ between playing positions. The purpose of this study was to explore potential differences in the seasonal prevalence of hip and groin problems between playing positions in male elite ice hockey players and to explore the relationship between symptom duration and hip and groin function at the beginning of the new season. METHODS: Male ice hockey players [n = 329 (92 goalkeepers, 93 defensemen, 144 forwards), Mean age (SD): 24 (5)] from the professional leagues in Sweden responded to an online survey. The survey assessed presence of hip and groin problems (time loss and non-time loss) and symptom duration (categorized into 0, 1-6, or > 6 weeks) in the previous season, and current self-reported hip and groin function (Copenhagen Hip and Groin Outcome Score). RESULTS: During the previous season, 175 players (53.2%) had experienced hip and groin problems. Non time loss problems were experienced by 158 (48%) and time loss problems were experienced by 97 (29.5%) players. No significant differences between playing positions were found. Self-reported function differed significantly between players with different symptom duration and more disability was reported among players with longer symptom duration (p ≤ 0.002). CONCLUSION: Regardless of playing position, hip and groin problems were prevalent in male ice hockey players. Players with hip and groin problems during the previous season had significantly worse hip and groin function in the beginning of the new season, and longer symptom duration was associated with more disability. LEVEL OF EVIDENCE: III.

Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain: consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018.

The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.

Hip Function 6 to 10 Months After Arthroscopic Surgery: A Cross-sectional Comparison of Subjective and Objective Hip Function, Including Performance-Based Measures, in Patients Versus Controls.

BACKGROUND: Little is known about hip-related function, mobility, and performance in patients after hip arthroscopic surgery (HA) during the time that return to sports can be expected. PURPOSE: To evaluate measures of subjective and objective hip function 6 to 10 months after HA in patients compared with healthy controls and to compare objective function in the HA group between the operated and nonoperated hips. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 33 patients who had undergone HA (mean, 8.1 ± 2.6 months postoperatively) and 33 healthy participants matched on sex, age, and activity level were compared regarding subjective hip function (Copenhagen Hip and Groin Outcome Score [HAGOS]) and objective function including hip range of motion (ROM; flexion, internal rotation, and external rotation), isometric hip muscle strength (adduction, abduction, flexion, internal rotation, and external rotation), and performance-based measures: the Y Balance Test (YBT), medial and lateral triple-hop test, and Illinois agility test. Group differences were analyzed using independent-samples t tests. Paired-samples t tests were used for a comparison of the operated and nonoperated hips. Standard effect sizes (Cohen d) were provided for all outcomes. RESULTS: The HA group reported worse subjective hip function than the control group (HAGOS subscores: d = -0.7 to -2.1; P ≤ .004). Objective measures of hip ROM (d = -0.5 to -1.1; P ≤ .048), hip flexion strength (d = -0.5; P = .043), and posteromedial reach of the YBT (d = -0.5; P = .043) were also reduced in the HA group, although there were no significant differences between groups regarding the remaining objective measures (d = -0.1 to -0.4; P ≥ .102 to .534). The only significant difference between the operated and nonoperated hips in the HA group was reduced passive hip flexion (d = -0.4; P = .045). CONCLUSION: Patients who had undergone HA demonstrated reduced subjective hip function compared with controls 6 to 10 months after surgery, when return to sports can be expected. While most objective strength and performance test results were comparable between the HA and control groups at 6 to 10 months after surgery, the HA group presented with impairments related to hip mobility and hip flexion strength. No consistent pattern of impairments was found in operated hips compared with nonoperated hips.

Worse self-reported outcomes but no limitations in performance-based measures in patients with long-standing hip and groin pain compared with healthy controls.

PURPOSE: This study aimed to evaluate patient-reported outcomes as well as lower extremity and trunk muscle function in patients with long-standing hip and groin pain, in comparison with matched, healthy controls. It was hypothesized that patients with long-standing hip and groin pain would report more deficiency on the Copenhagen Hip and Groin Outcome Score (HAGOS) and have worse outcomes on performance-based measures than healthy controls. METHODS: Nineteen patients with long-standing hip and groin pain and 19 healthy, activity level-, age-, gender-, and weight-matched controls were assessed with the HAGOS for self-reported outcomes, and a parallel squat (w/kg), single-leg triple jump (cm), single-leg rise (n), barbell roll-out (% of height), and plank test (s) for performance-based measures. Independent sample t test was performed to assess between-group differences. The paired t test was used to analyse between-limb differences in unilateral performance tasks. RESULTS: The patients had worse scores than the controls in all HAGOS subscales (p ≤ 0.001), while no statistically significant differences were observed for any performance measure between groups or between symptomatic and non-symptomatic limbs. CONCLUSIONS: Despite significant self-reported functional limitations on the HAGOS, there were no significant differences between groups in performance-based strength or power measures. The results of this study highlight the need to identify performance-based measures, sensitive to functional deficiencies in patients with long-standing hip and groin pain in order to complement the clinical picture obtained by patient-reported outcomes such as the HAGOS. LEVEL OF EVIDENCE: III.