Danish Hip Arthroscopy Registry (DHAR): the outcome of patients with femoroacetabular impingement (FAI)

Relationship of Average Outcomes Scores and Change in Status Requires Further Interpretation Between 1 and 2 Years Following Hip Arthroscopy

BACKGROUND

Previous studies have demonstrated a clinically impactful change in patients between 1 and 2 years after hip arthroscopy. Assessment of differences in patient-specific factors between patients who remain the same and those who change (ie, either improve or decline) could provide valuable outcome information for orthopaedic surgeons treating those patients.

PURPOSE

To identify patients who experienced change in functional status between 1 and 2 years after hip arthroscopy for femoroacetabular impingement syndrome and assess differences in patient-specific factors between those who improved, remained the same, or declined in functional status.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospectively collected data for patients who underwent hip arthroscopy at 1 of 7 centers were analyzed retrospectively at 1 year and 2 years postoperatively. Patients were categorized as "improved,""remained the same," or "declined" between 1- and 2-year follow-up based on the 12-item International Hip Outcome Tool (iHOT-12) minimal clinically important difference (MCID) value. A 1-way analysis of variance was used to assess differences in iHOT-12 scores, age, body mass index (BMI), alpha angle, and center-edge angle (CEA) between groups. Chi-square analyses were used to assess differences in the proportions of male and female patients in the outcome groups.

RESULTS

The study included 753 patients (515 women and 238 men), whose mean ± SD age was 34.7 ± 12 years. Average 1-year (±1 month) and 2-year (±2 months) iHOT-12 scores for all patients were 73.7 and 74.9, respectively. Based on the calculated MCID of ±11.5 points, 162 (21.5%) patients improved, 451 (59.9%) remained the same, and 140 (18.6%) declined in status between 1- and 2-year follow-up. Those who improved between 1 and 2 years had lower 1-year iHOT-12 scores (P < .0005). We found no difference in age, BMI, alpha angle, CEA, or sex between groups (P > .05).

CONCLUSION

Between 1- and 2-year follow-up assessments, 21.5% of patients improved and 18.6% declined in self-reported functional status. Those with iHOT-12 scores indicating abnormal function at 1 year improved beyond the MCID at 2 years follow-up. Thus, any decisions about the failure or success of arthroscopic hip procedures should not be made until at least the 2-year follow-up. Failing to thrive at 1-year follow-up may not accurately predict outcomes at year 2 or beyond. This could potentially decrease the perceived need for revision surgery in patients who do not thrive before 2-year follow-up.

Limited clinical utility of a machine learning revision prediction model based on a national hip arthroscopy registry

PURPOSE

Accurate prediction of outcome following hip arthroscopy is challenging and machine learning has the potential to improve our predictive capability. The purpose of this study was to determine if machine learning analysis of the Danish Hip Arthroscopy Registry (DHAR) can develop a clinically meaningful calculator for predicting the probability of a patient undergoing subsequent revision surgery following primary hip arthroscopy.

METHODS

Machine learning analysis was performed on the DHAR. The primary outcome for the models was probability of revision hip arthroscopy within 1, 2, and/or 5 years after primary hip arthroscopy. Data were split randomly into training (75%) and test (25%) sets. Four models intended for these types of data were tested: Cox elastic net, random survival forest, gradient boosted regression (GBM), and super learner. These four models represent a range of approaches to statistical details like variable selection and model complexity. Model performance was assessed by calculating calibration and area under the curve (AUC). Analysis was performed using only variables available in the pre-operative clinical setting and then repeated to compare model performance using all variables available in the registry.

RESULTS

In total, 5581 patients were included for analysis. Average follow-up time or time-to-revision was 4.25 years (± 2.51) years and overall revision rate was 11%. All four models were generally well calibrated and demonstrated concordance in the moderate range when restricted to only pre-operative variables (0.62-0.67), and when considering all variables available in the registry (0.63-0.66). The 95% confidence intervals for model concordance were wide for both analyses, ranging from a low of 0.53 to a high of 0.75, indicating uncertainty about the true accuracy of the models.

CONCLUSION

The association between pre-surgical factors and outcome following hip arthroscopy is complex. Machine learning analysis of the DHAR produced a model capable of predicting revision surgery risk following primary hip arthroscopy that demonstrated moderate accuracy but likely limited clinical usefulness. Prediction accuracy would benefit from enhanced data quality within the registry and this preliminary study holds promise for future model generation as the DHAR matures. Ongoing collection of high-quality data by the DHAR should enable improved patient-specific outcome prediction that is generalisable across the population.

LEVEL OF EVIDENCE

Level III.

Integrity of the hip capsule measured with magnetic resonance imaging after capsular repair or unrepaired capsulotomy in hip arthroscopy

BACKGROUND

Current literature shows no clear answer on the question how to manage the capsule after hip arthroscopy. Regarding patient reported outcome measures there seems to be no difference between capsular repair or unrepaired capsulotomy.

AIM

To evaluate and compare the integrity of the hip capsule measured on a magnetic resonance imaging (MRI) scan after capsular repair or unrepaired capsulotomy.

METHODS

A case series study was performed; a random sample of patients included in a trial comparing capsular repair vs unrepaired capsulotomy had a postoperative MRI scan. The presence of a capsular defect and gap size were independently evaluated on MRI.

RESULTS

A total of 28 patients (29 hips) were included. Patient demographics were comparable between treatment groups. There were 2 capsular defects in the capsular repair group and 7 capsular defects in the unrepaired capsulotomy group (P = 0.13). In the group of patients with a defect, median gap sizes at the acetabular side were 5.9 mm (range: 2.7-9.0) in the repaired and 8.0 mm (range: 4.5-18.0) in the unrepaired group (P = 0.462). At the muscular side gap sizes were 6.6 mm (range: 4.1-9.0) in the repaired group and 11.5 mm (range: 3.0-18.0) in the unrepaired group (P = 0.857). The calculated Odds ratio (OR) for having a capsular defect with an increasing lateral center-edge (CE) angle was 1.12 (P = 0.06). The OR for having a capsular defect is lower in the group of patients that underwent a labral repair with an OR of 0.1 (P = 0.05).

CONCLUSION

There is no significant difference in capsular defects between capsular repair or unrepaired capsulotomy. Regarding clinical characteristics our case series shows that a larger CE angle increases the likelihood of a capsular defect and the presence of a labral repair decreases the likelihood of a capsular defect.

Five-Year Follow-up After Hip Arthroscopic Surgery in the Horsens-Aarhus Femoroacetabular Impingement (HAFAI) Cohort

Background:

Patients with femoroacetabular impingement syndrome (FAIS) are offered hip arthroscopic surgery to decrease hip pain, improve their function, and decrease development of hip osteoarthritis (OA). Nonetheless, long-term follow-up data are few.

Purpose:

To investigate patient-reported outcomes, clinical tests, reoperations, and radiographic status 5 years after primary hip arthroscopy in patients with FAIS.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 60 patients (age, 36 ± 9 years; 63% female) diagnosed with FAIS were included in the study and followed for 5 years after hip arthroscopy. Follow-up included Copenhagen Hip and Groin Outcome Score (HAGOS); Hip Sports Activity Scale; and clinical tests (flexion, adduction, internal rotation [FADIR]; flexion, abduction, external rotation [FABER]; and psoas muscle/tendon major pain provocation). Radiographic evaluation included lateral joint-space width (LJSW) and Tönnis classification for hip OA. Reoperations and conversion to total hip replacement (THR) were recorded. We calculated the proportion of patients who exceeded the minimal important change (MIC), achieved the Patient Acceptable Symptom State (PASS), and were within the 95% reference interval of age- and sex-matched persons with no hip problems. Changes were investigated using paired t tests.

Results:

Compared with preoperatively, all HAGOS subscales were improved substantially 5 years after surgery (mean, ≥21 points; P < .001), and 67% to 89% of patients reported improvements exceeding MIC. Between 56% and 80% achieved PASS, but only 7% to 24% reached the 95% reference interval for the HAGOS subscales. A total of 36% had a positive FADIR test and 25% had a positive FABER test, which were improvements compared with preoperatively (P < .001 for both). Patients with a positive FADIR test had significantly worse HAGOS subscales. Six patients (10%) had a THR since their primary hip arthroscopy. In the remaining patients, the mean LJSW was decreased (-0.4 mm; P = .043), and hip OA had worsened in 9 patients (23%; P = .003).

Conclusion:

Five years after surgery, the majority of patients experienced HAGOS improvements exceeding MIC while also showing an acceptable PASS. However, clinical tests, participation in physical activities, and quality of life indicated that many patients still experience hip problems.

Registration:

NCT04590924 (ClinicalTrials.gov identifier).

Evaluation of Differences Between Non-Hispanic White and African American Patients With Sports Medicine–Related Hip Disabilities

Background:

Racial disparities within the field of orthopaedics are well-documented in the spinal surgery, knee arthroplasty, and hip arthroplasty literature. Not much is known about racial differences in patients with sports medicine–related hip disabilities.

Purpose:

To investigate whether differences exist between African American and non-Hispanic White (White) patients evaluated for hip disabilities.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We performed a multicenter retrospective cohort study of 905 patients who were evaluated over a 1-year period for hip-related orthopaedic concerns. Patient demographic data, disability characteristics, and hip radiographic findings were obtained from electronic medical records. We also obtained data on whether patients were offered physical therapy, magnetic resonance imaging (MRI), and/or surgery. Comparisons by race and insurance status were evaluated using univariate and multivariate analyses.

Results:

African Americans comprised a significantly lower proportion of the patients evaluated for hip-related disabilities compared with Whites (6.5% vs 93.5%; P < .001). A significantly smaller proportion of African Americans with hip disabilities was recommended for surgery than White patients (35.6% vs 54.6%; P = .007). Cam deformities were more common in White vs African American patients (39.7% vs 23.7%; P = .021), as were labral tears (54.1% vs 35.6%; P = .009). Logistic regression demonstrated that neither race nor insurance status were significant determinants in surgery recommendations. Conversely, race was a determinant of whether an MRI was performed, as White patients were 2.74 times more likely to have this procedure. There were no differences with respect to obtaining an MRI between private and Medicaid insurance.

Conclusion:

Compared with White patients, there were differences in both the proportion of African Americans evaluated for hip-related disabilities and the proportion receiving a surgery recommendation. African Americans with sports medicine–related hip issues were also less likely to obtain an MRI. With regard to observed pathology, African American patients were less likely to have cam deformities and labral tears than White patients.

Hip joint motion does not change one year after arthroscopic osteochondroplasty in patients with femoroacetabular impingement evaluated with dynamic radiostereometry

Purpose

Dynamic radiostereometric analysis (dRSA) enables precise non-invasive three-dimensional motion-tracking of bones for assessment of joint kinematics. Hereby, the biomechanical effects of arthroscopic osteochondroplasty of the hip (ACH) can be evaluated in patients with femoroacetabular impingement (FAI).

The aim was to investigate the pre- and postoperative range of motion (ROM) and the CT bone volume removed (BV) after ACH. We hypothesize increase in ROM 1 year after surgery.

Methods

Thirteen patients (6 female) with symptomatic FAI were included prospectively. The patient’s hips were CT-scanned and CT-bone models were created. Preoperative dRSA recordings were acquired during passive flexion to 90°, adduction, and internal rotation (FADIR). ACH was performed, CT and dRSA were repeated 3 months and 1 year postoperatively. Hip joint kinematics before, and 3 months and 1 year after ACH were compared pairwise. The bone volume removal was quantified and compared to change in ROM.

Results

Mean hip internal rotation, adduction and flexion were all unchanged after ACH at 1-year follow-up (p > 0.84). HAGOS scores revealed improvement of quality of life (QOL) from 32 to 60 (p = 0.02). The BV was between 406 and 1783 mm³ and did not correlate to post-operative ROM.

Conclusions

ACH surgery in FAI patients had no impact of ROM at 1-year follow-up. QOL improved significantly. This indicates that the positive clinical effects reported after ACH might be a result of reduced labral stress and cartilage pressure during end-range motion rather than increased ROM.

Level of evidence

Therapeutic prospective cohort study, level II.

Arthroscopic treatment for femoroacetabular impingement syndrome (FAIS) in adolescents—5-year follow-up

To report the minimum 5-year outcome after hip arthroscopy with labral repair in adolescents. From 2011 to 2014, 29 consecutive patients with a mean age 16.3 years (range 12.7–19.8 years) underwent hip arthroscopy treatment for femoroacetabular impingement syndrome. Patient-related outcome measures (PROMs) including modified Harris Hip Score (mHHS), Visual Analog Scale (VAS) for pain and Copenhagen Hip and Groin Outcome Score (HAGOS) were used preoperatively and at follow-up (FU). Percentage of patients achieving minimum clinically important difference (MCID) and substantial clinical benefit (SCB) for mHHS and HAGOS were determined. Mean FU was 6.7 years (range 5–9.6 years), and a 100% FU was accomplished. Significant improvements were seen for all PROMs at FU in patients not having a periacetabular osteotomy (PAO) with VAS pain score improving from mean 62 to 9, mHHS from 58 to 94 and HAGOS improved in all subgroups. For mHHS, SCB changes were achieved by 76% and MCID by 76% of the patients. Percentage of patients achieving MCID for HAGOS subgroups were 81% for pain, 67% for symptoms, 76% for physical function in daily living, 76% for physical function in sport and recreation, 81% for participation in physical activities and 81% for hip-related quality of life. Two patients had revision hip arthroscopy. PAO was later performed in three patients. The risk of further surgery with center edge (CE) bony edge (CEB) <30° was 42% and 0% with CEB ≥30°. Adolescents having hip arthroscopy with labral repair and resection of cam and pincer morphology achieve significant improvements at mean 6.7 years of FU. CEB < 30° increases the risk of further surgery.

Low rate of adverse events in a randomized controlled trial addressing the surgical treatment of femoroacetabular impingement (FAI) syndrome

PURPOSE

The femoroacetabular impingement randomised controlled trial (FIRST) is a multi-center randomized controlled trial (RCT), comparing arthroscopic osteochondroplasty with arthroscopic lavage in adults aged 18-50 years diagnosed with non-arthritic femoroacetabular impingement (FAI) syndrome. The purpose of the present study is to report the prevalence, distribution and severity of adverse events during and within 24-month follow-up period.

METHODS

Of the 220 patients included, 6 were adjudicated as ineligible, for a total of 214 patients included in the final analysis. An independent Adjudication Committee evaluated operatively treated and non-operatively treated adverse events that were related to the hip. Adverse events were also reported directly by each participating clinical site. Continuous variables were reported as mean and standard deviation, categorical variables were reported as counts and percentages.

RESULTS

There were a total of 52 (24.2%, 52/214) adverse events in 46 (21.5%) patients (mean age 34.2 ± 7.9 years, 58.7% male) during the 24-month follow-up. There were 12.6% (27/214) operatively treated adverse events for: hip pain, re-injury of labrum and heterotopic ossification. There were 11.7% (25/214) non-operatively treated adverse events for predominantly: hip pain, hip tendinopathy and hip popping/snapping. Approximately, 87% of adverse events resolved within the 24-month follow-up time.

CONCLUSION

Given the inherent challenges with conducting RCTs, the results of this adverse event study from the FIRST trial demonstrate that it is safe to perform an RCT addressing FAI syndrome.

LEVEL OF EVIDENCE

Level III.

Hip arthroscopy with initial access to the peripheral compartment provides significant improvement in FAI patients

PURPOSE

This study was designed to evaluate the clinical and radiographic results of arthroscopic treatment of femoroacetabular impingement (FAI) using the technique of initial access to the peripheral compartment. It is based on a single surgeon large case series with a minimum of 2 years follow-up.

METHODS

Prospective longitudinal study with consecutive patients. Inclusion criteria were the presence of FAI syndrome that had failed non-operative treatment and had a hip arthroscopy with initial access to the peripheral compartment. Exclusion criteria were previous hip surgery, patients younger than 16 or older than 60 years, Tönnis grade ≥ 2 osteoarthritis, hip dysplasia based on radiographic evidence of LCEA less than 25° and workers compensation cases. One hundred and sixty hips met the inclusion criteria, 84 were female and 70 were male patients (six bilateral cases), with a median age of 36 years (range 16-59).

RESULTS

The median alpha angle correction was 22.6º (range 5.9-46.7) (p < 0.01) and the average LCEA correction when acetabuloplasty was undertaken was 6.5º (range - 1.4-20.8) (p < 0.01). The mean NAHS at baseline was 56.1 (range 16-96) and improved to 83.2 at the last follow up (range 44-100) for the patients that had no additional procedure (p < 0.01). The mean average improvement was 27.7º points (range - 16-73). No iatrogenic labral perforation and no full-thickness chondral damage were recorded during the arthroscopic procedures.

CONCLUSIONS

Favourable outcomes are reported for the arthroscopic treatment of FAI with initial access to the peripheral compartment. The technique is protective against iatrogenic chondral and labral damage, more conservative to the joint capsule, but the mean traction time was relatively long when suture anchors were used. The results are comparable to the classic initial central compartment approach.

LEVEL OF EVIDENCE

Level IV.

Evaluation of outcome reporting trends for femoroacetabular impingement syndrome- a systematic review

PURPOSE

The aim of this systematic review was to evaluate the trends in the literature regarding surgical treatment for femoroacetabular impingement syndrome (FAIS) and to present which patient-reported outcome-measures (PROMs) and surgical approaches are included.

METHODS

This systematic review was conducted with the PRISMA guidelines. The literature search was performed on PubMed and Embase, covering studies from 1999 to 2020. Inclusion criteria were clinical studies with surgical treatment for FAIS, the use of PROMs as evaluation tool and studies in English. Exclusion criteria were studies with patients < 18 years, cohorts with < 8 patients, studies with primarily purpose to evaluate other diagnoses than FAIS and studies with radiographs as only outcomes without using PROMs. Data extracted were author, year, surgical intervention, type of study, level of evidence, demographics of included patients, and PROMs.

RESULTS

The initial search yielded 2,559 studies, of which 196 were included. There was an increase of 2,043% in the number of studies from the first to the last five years (2004-2008)-(2016-2020). There were 135 (69%) retrospective, 55 (28%) prospective and 6 (3%) Randomized Controlled Trials. Level of evidence ranged from I-IV where Level III was most common (44%). More than half of the studies (58%) originated from USA. Arthroscopic surgery was the most common surgical treatment (85%). Mean follow-up was 27.0 months (± 17 SD), (range 1.5-120 months). Between 1-10 PROMs were included, and the modified Harris Hip Score (mHHS) was most commonly used (61%).

CONCLUSION

There has been a continuous increase in the number of published studies regarding FAIS with the majority evaluating arthroscopic surgery. The mHHS remains being the most commonly used PROM.

Femoroacetabular impingement: correlation between imaging parameters, sport activity, and chondral damage

BACKGROUND

Femoroacetabular impingement is characterised by an abnormal contact between the acetabulum and the femoral head-neck junction. Femoroacetabular impingement shows three main clinical frameworks: Pincer-FAI, Cam-FAI and Cam-Pincer mixed form. The aim of the study was to investigate the correlation between femoroacetabular impingement, imaging, activity and chondral damages.

METHODS

Forty-one patients, undergoing arthroscopic chondroartroplasty for Cam and Cam-Pincer mixed form were considered. All patients underwent an X-ray hip evaluation (G1 group), while 15 patients also underwent a pelvis MRI evaluation (G2 subgroup). For G1 patients, the superior-inferior offset ratio and alpha angle were calculated from the X-ray examinations. For G2 patients, the antero-posterior offset ratio was also calculated from pelvis MRI. Chondral damage was classified according to the Outerbridge classification.

RESULTS

The superior-inferior offset ratio and the antero-posterior offset ratio were respectively 0.50 ± 0.23 and 0.33 ± 0.19. The α angle predictive for a chondral damage of IV degree was 81.5°.The chondral damage of the patients suffering from Cam-FAI and Cam-Pincer mixed form were respectively 3.53±0.80 and 3.00±1.41.

CONCLUSIONS

From the results was possible to: - Elaborate two tables providing a reliable indirect calculation of the alpha angle. - Establish an alpha angle cut-off value indicative for a IV degree chondral damage. - Show that Pincer-FAI does not represent an aggravating factor for chondral damage - Show that the level of sports activity was related to the severity of chondral damage. - Show that a physically demanding occupation was not an aggravating factor for chondral damage.

How Many Patients Achieve an Acceptable Symptom State After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? A Cross-sectional Study Including PASS Cutoff Values for the HAGOS and iHOT-33

Background

Hip arthroscopy is a viable treatment for femoroacetabular impingement syndrome (FAIS). Clinically relevant improvements in hip function and pain after surgery are often reported, but it is less clear how many patients achieve an acceptable symptom state (Patient Acceptable Symptom State [PASS]).

Purpose

To investigate the proportion of patients who achieved a PASS 12 to 24 months after hip arthroscopy and to determine the cutoff scores of the 2 recommended and valid patient-reported outcome measures (the subscales of the Copenhagen Hip and Groin Outcome Score [HAGOS] and the International Hip Outcome Tool-33 [iHOT-33]) for which patients are most likely to achieve PASS.

Study Design

Cohort study; Level of evidence, 3.

Methods

Eligible study patients were identified in the Danish Hip Arthroscopy Registry. An electronic questionnaire was used to collect data on PASS, HAGOS, and iHOT-33 12 to 24 months after surgery. PASS was measured using an anchor question. Receiver operating characteristic curve analyses were applied to identify the PASS cutoff values of HAGOS and iHOT-33 scores.

Results

A total of 137 individuals (mean age at surgery, 35.4 ± 9.4 years) were included in the study at a mean follow-up of 18.5 ± 3.2 months after surgery. At follow-up, 64 individuals (46.7%; 95% CI, 38.6-55.1) reported PASS. Higher HAGOS and iHOT-33 values were observed for participants who reported PASS compared with those who did not report PASS (Cohen d ≥ 1.06; P < .001). Cutoff scores for HAGOS subscales (42.5-82.5) and iHOT-33 (67.00) showed excellent to outstanding discriminative ability in predicting PASS (area under the curve, 0.82-0.92).

Conclusion

In total, 46% of individuals having hip arthroscopy for FAIS achieved PASS at 12 to 24 months of follow-up. Patients who achieved PASS had statistically significant and substantially better self-reported hip function compared with those who did not achieve PASS. Cutoff values at HAGOS subscales and iHOT-33 showed excellent to outstanding discriminative ability in predicting patients with PASS.

Clinical outcomes after revision hip arthroscopy in patients with femoroacetabular impingement syndrome (FAIS) are inferior compared to primary procedures. Results from the Danish Hip Arthroscopy Registry (DHAR)

PURPOSE

As many as 10% of primary hip arthroscopies end up with a revision arthroscopy procedure when treating patients suffering from femoroacetabular impingement syndrome (FAIS). In general, revision procedures are indicated because of residual impingement, but only a few studies present outcome data from revision hip arthroscopy after failed FAIS surgical treatment. The purpose of this study was to evaluate clinical outcomes after revision hip arthroscopy in a FAIS cohort and compare outcomes with a primary FAIS hip arthroscopy cohort and describe potential causes of failure after the primary hip arthroscopy. It was hypothesized that subjective outcomes improve after revision hip arthroscopy although outcomes were expected to be inferior to primary hip arthroscopic outcomes.

METHODS

Three-hundred and thirty-one arthroscopic revision hip FAIS patients were included from the Danish Hip Arthroscopy Registry (DHAR). Patient-related outcome measures (PROM's), Copenhagen Hip and Groin Outcome Scores (HAGOS), Hip Sports Activity Scale (HSAS), EQ-5D and Numeric Rating Scale (NRS) pain, were assessed in the study cohort prior to the primary procedure and at revision and at follow-up one year after the revision procedure. These data were compared with 4154 primary hip arthroscopic FAIS patients.

RESULTS

One-year after revision surgery, mean follow-up (in months ± SD): 12.3 ± 1.6, significant improvements (p < 0.05) in all PROMs was demonstrated, but FAIS patients in the primary hip arthroscopic cohort demonstrated significantly higher outcomes, in all PROMs, when compared at one-year follow-up. Scar tissue, residual osseous impingement and insufficient healing of the labral repair were reported as the main reasons for revision surgery. The conversion to total hip arthroplasty was low (6.4%).

CONCLUSION

Revision hip arthroscopy in FAIS patients improves subjective outcomes significantly, although they are poorer than after primary FAIS hip arthroscopy. Main reasons for revision arthroscopy was scar tissue, residual femoroacetabular impingement and insufficient healing of labral repair.

LEVEL OF EVIDENCE

Level III.

Sex Differences in Clinical Outcomes Following Surgical Treatment of Femoroacetabular Impingement

BACKGROUND

Sex-based differences in clinical outcomes following surgical treatment of femoroacetabular impingement remain largely uncharacterized; this prospective, multicenter study evaluated these differences both directly and adjusted for covariates.

METHODS

Hips undergoing surgical treatment of symptomatic femoroacetabular impingement were prospectively enrolled in a multicenter cohort. Patient demographics, radiographic parameters, intraoperatively assessed disease severity, and history of surgical procedures, as well as patient-reported outcome measures, were collected preoperatively and at a mean follow-up of 4.3 years. A total of 621 (81.6%) of 761 enrolled hips met the minimum 1 year of follow-up and were included in the analysis; 56.7% of analyzed hips were female. Univariate and multivariable statistics were utilized to assess the direct and adjusted differences in outcomes, respectively.

RESULTS

Male hips had greater body mass index and larger α angles. Female hips had significantly lower preoperative and postoperative scores across most patient-reported outcome measures, but also had greater improvement from preoperatively to postoperatively. The preoperative differences between sexes exceeded the threshold for the minimal clinically important difference of the modified Harris hip score (mHHS) and all Hip disability and Osteoarthritis Outcome Score (HOOS) domains except quality of life. Preoperative sex differences in mHHS, all HOOS domains, and Short Form-12 Health Survey physical function component score were greater than the postoperative differences. A greater proportion of female hips achieved the minimal clinically important difference for the mHHS, but male hips were more likely to meet the patient acceptable symptom state for this outcome. After adjusting for relevant covariates with use of multiple regression analysis, sex was not identified as an independent predictor of any outcome. Preoperative patient-reported outcome scores were a strong and highly significant predictor of all outcomes.

CONCLUSIONS

Significant differences in clinical outcomes were observed between sexes in a large cohort of hips undergoing surgical treatment of femoroacetabular impingement. Despite female hips exhibiting lower baseline scores, sex was not an independent predictor of outcome or reoperation.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Substantial Loss to Follow-Up and Missing Data in National Arthroscopy Registries: A Systematic Review

PURPOSE

To report follow-up methodologies, compliance, and existing strategies for handling missing data in national arthroscopy registries collecting patient-reported outcome measures (PROMs).

METHODS

Annual reports, EMBASE, and MEDLINE were queried following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to identify national arthroscopy registries reporting follow-up with a validated PROM and sample size greater than 500. Extracted data included weighted compliance in peer-reviewed publications, cumulative compliance throughout the time span of data collection, and missing-data methodologies.

RESULTS

Nine national arthroscopy registries currently collect PROMs, with cumulative rates of follow-up ranging from less than 10% to more than 70%. We identified 36 publications from 5 national registries reporting hip and knee arthroscopies. The weighted mean compliance with PROMs in national registry publications was 56% at 0.5 years, 44% to 59% at 1 year, 40% to 61% at 2 years, 35% to 54% at 5 years, and 40% at 10 years. A missing-data analysis was reported or referenced in 58% of publications.

CONCLUSIONS

In national arthroscopy registries, compliance with 2-year PROMs does not meet traditional follow-up thresholds of 60% or 80% and reporting of missing-data methodologies is inconsistent.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 3: imaging techniques

OBJECTIVES

Imaging diagnosis of femoroacetabular impingement (FAI) remains controversial due to a lack of high-level evidence, leading to significant variability in patient management. Optimizing protocols and technical details is essential in FAI imaging, although challenging in clinical practice. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal consensus techniques driven by relevant literature review. Recommendations on the selection and use of imaging techniques for FAI assessment, as well as guidance on relevant radiographic and MRI classifications, are provided.

METHODS

The Delphi method was used to assess agreement and derive consensus among 30 panel members (musculoskeletal radiologists and orthopedic surgeons). Forty-four questions were agreed on and classified into five major topics and recent relevant literature was circulated, in order to produce answering statements. The level of evidence was assessed for all statements and panel members scored their level of agreement with each statement during 4 Delphi rounds. Either "group consensus," "group agreement," or "no agreement" was achieved.

RESULTS

Forty-seven statements were generated and group consensus was reached for 45. Twenty-two statements pertaining to "Imaging techniques" were generated. Eight statements on "Radiographic assessment" and 12 statements on "MRI evaluation" gained consensus. No agreement was reached for the 2 "Ultrasound" related statements.

CONCLUSION

The first international consensus on FAI imaging was developed. Researchers and clinicians working with FAI and hip-related pain may use these recommendations to guide, develop, and implement comprehensive, evidence-based imaging protocols and classifications.

KEY POINTS

• Radiographic evaluation is recommended for the initial assessment of FAI, while MRI with a dedicated protocol is the gold standard imaging technique for the comprehensive evaluation of this condition. • The MRI protocol for FAI evaluation should include unilateral small FOV with radial imaging, femoral torsion assessment, and a fluid sensitive sequence covering the whole pelvis. • The definite role of other imaging methods in FAI, such as ultrasound or CT, is still not well defined.

The influence of pain catastrophizing and central sensitization on the reported pain after hip arthroscopy

PURPOSE

This study was conducted to investigate whether the pain catastrophizing scale (PCS) and the central sensitization inventory (CSI) are predictive factors for the reported pain after hip arthroscopy.

METHODS

A total of 37 patients undergoing hip arthroscopy for femoroacetabular impingement syndrome and labral tears were prospectively enrolled. All patients completed the PCS and CSI before hip arthroscopy. Postoperative pain was measured with the numeric rating scale (NRS) weekly the first 12 weeks after surgery by electronic diary.

RESULTS

At baseline, univariate analyses showed that both the CSI and PCS were significantly associated with the NRS outcome (p < 0.01). During 12 weeks follow-up, a significant decrease on the NRS was observed (p < 0.01). Univariate analyses showed that both the CSI and PCS were significantly associated with the NRS during follow-up. Multivariate mixed model analysis showed that only the PCS remained significantly associated with the NRS outcome with a ß of 0.07 (95% CI 0.03-0.11, p < 0.01).

CONCLUSION

Results indicate that both the PCS and CSI are associated with the reported postoperative pain after hip arthroscopy. The PCS and CSI may be useful in daily practice to identify patients that possibly benefit from pain catastrophizing reduction therapy (e.g. counseling) prior to surgery.

LEVEL OF EVIDENCE

IV.

Teamwork in hip preservation: the ISHA 2019 Annual Scientific Meeting

Hip preservation surgery is now an established part of orthopedic surgery and sports medicine. This report describes the key findings of the 11th Annual Scientific Meeting of International Society for Hip Arthroscopy-the International Hip Preservation Society-in Madrid, Spain from 16 to 19 October 2019. Lectures, seminars and debates explored the most up-to-date and expert views on a wide variety of subjects, including: diagnostic problems in groin pain, buttock pain and low back pain; surgical techniques in acetabular dysplasia, hip instability, femoroacetabular impingement syndrome, labral repair and reconstruction, cartilage defects, adolescent hips and gluteus medius and hamstring tears; and new ideas about femoral torsion, hip-spine syndrome, hip capsule surgery, impact of particular sports on hip injuries, registries, robotics and training for hip preservation specialists. Surgeons, sports physicians, radiologists and physiotherapists looking after young people with hip problems have an increasingly sophisticated armoury of ideas and techniques with which to help their patients. The concept of hip preservation has developed incredibly fast over the last decade; now it is clear that the best results can only be achieved by a multidisciplinary team working together. The 2020s will be the decade of 'Teamwork in Hip Preservation'.

Loss to follow-up: initial non-responders do not differ from responders in terms of 2-year outcome in a hip arthroscopy registry

Loss to follow-up in registry studies is a problem due to potential selection bias. There is no consensus on the effect of response rate. The aim of this study was to compare patient-reported outcome measures (PROMs) between responders and initial non-responders (INR) in a hip arthroscopy registry and to examine whether demographics affect the response rate. Data from hip arthroscopies performed at two centres in Gothenburg were collected and the patients were followed up with PROMs. The follow-up was a minimum of 2 years after surgery. All 536 patients who underwent primary hip arthroscopies during 2015 and 2016 and had recorded pre-operative PROMs were included. A total of 396 patients completed the follow-up and were labelled 'Responders' (R) and 107 patients responded after reminders were sent and labelled 'Initial non-responders' (INR). The mean time of follow-up was 24.7 ± 2.9 and 42.5 ± 7.0 months for the R- and INR-group, respectively. There were no differences between the two groups at the follow-up for the Copenhagen Hip and Groin Outcome Score, European Quality of life 5 dimensions questionnaire, EQ-VAS, International Hip Outcome Tool or a visual analogue scale for hip function. A larger proportion of R was satisfied after hip arthroscopy compared with INR (86% versus 70%, P = 0.0003). INR were younger than responders (31.5 ± 12.5 versus 35.6 ± 12.7 years of age). The conclusion of the study was that there were no differences between R and INR at the follow-up across the PROMs except patient satisfaction, where responders were more satisfied.

Importance of Retaining Sufficient Acetabular Depth: Successful 2-Year Outcomes of Hip Arthroscopy for Patients With Pincer Morphology as Compared With Matched Controls

BACKGROUND

Patients with pincer-type femoroacetabular impingement are commonly treated with arthroscopic reduction of acetabular depth as measured by the lateral center-edge angle (LCEA). The optimal amount of rim reduction has not been established, although large resections may increase contact pressures through the hip. A recent publication demonstrated inferior surgical outcomes in patients with acetabular overcoverage as compared with normal acetabular coverage. Casual observation of our database suggested equivalent improvements, prompting a similar analysis.

PURPOSE

To analyze patient-reported outcomes after hip arthroscopy for femoroacetabular impingement in patients with acetabular overcoverage who were matched with controls with normal coverage, as well as to analyze associations with reduction in LCEA.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were collected prospectively from patients with a minimum 2-year follow-up after receiving hip arthroscopy for femoroacetabular impingement by a single surgeon. Cases were reviewed to identify those with pincer-type morphology (LCEA >40°) and matched according to sex, age, chondral damage, and surgery date in a 1:1 ratio with controls with an LCEA of 25° to 40°. The surgical goal was to reduce the LCEA to the upper end of the normal range with minimal rim resection, usually 35° to 37°. Radiographic measurements of coverage, intraoperative findings, procedures, and patient-reported outcomes were recorded, including the 12-Item International Hip Outcome Tool, Non-arthritic Hip Score, Hip Disability and Osteoarthritis Outcome Score, visual analog scale for pain, rates of revision or reoperation, and conversion to total hip arthroplasty.

RESULTS

A total of 114 hips (93 patients) for the pincer group were matched 1:1 from 616 hips (541 patients) for the control group. The pincer group (mean ± SD age, 34.5 ± 12.2 years) did not differ in age, body mass index, or follow-up from controls. LCEA was reduced in both groups pre- to postoperatively: the pincer group from 44.0° ± 2.8° to 34.2° ± 3.5° and the controls from 32.9° ± 3.9° to 31.0° ± 3.0°. No differences in improvement were observed: iHOT-12 improved by 35.7 points in both groups (P = .9 for analysis of variance interaction) and Nonarthritic Hip Score by 22.3 points (P = .6). From all eligible surgical procedures, 2-year follow up rates were 2.5% and 2.6% for the pincer and control cohorts, respectively, and 1.2% and 0.3% for conversion to total hip arthroplasty.

CONCLUSION

Arthroscopic management of acetabular overcoverage can achieve excellent results, equivalent to arthroscopy for other causes of symptomatic femoroacetabular impingement. A key finding was smaller rim resections producing a mean postoperative LCEA of 34.2° with a small standard deviation.

Does failure to meet threshold scores for mHHS and iHOT-12 correlate to secondary operations following hip arthroscopy?

The purpose of this study was to determine (i) if failing to achieve a patient-reported outcome (PRO) threshold at 1 year was associated with secondary operations at minimum 2-year follow-up and (ii)what outcome measure and threshold has the highest association with future surgeries. Inclusion criteria for this study were cases of primary hip arthroscopy between July 2014 and April 2017. Included patients had recorded pre-operative and 1-year post-operative modified Harris Hip Score (mHHS) and 12-item international Hip Outcome Tool (iHOT-12) scores. Patients were classified based on their ability to achieve minimal clinical important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptom state (PASS) for each PRO and the status of secondary operations at minimum 2-year follow-up. The sensitivity, specificity, accuracy, positive likelihood ratio and negative likelihood ratio for these thresholds were calculated. Of 425 eligible cases, 369 (86.8%) had minimum 2-year follow-up. Of the included patients, 28 underwent secondary operations (7.59%), with 14 undergoing secondary arthroscopies (3.79%) and 14 converting to total hip arthroplasty (3.79%). For mHHS, 267 (72.4%), 173 (46.9%) and 277 (75.1%) hips met MCID, SCB and PASS, respectively. For iHOT-12, 234 (63.4%), 218 (59.1%) and 280 (75.9%) hips met the respective thresholds. The highest specificity, sensitivity and accuracy were identified as for iHOT-12 MCID (0.79), iHOT-12 PASS (0.79) and iHOT-12 MCID (0.77), respectively. Patients not attaining MCID and PASS for mHHS and iHOT-12 at 1-year post-operatively are at increased risk of secondary operation. The most accurate threshold associated with secondary operation (0.77) is not achieving iHOT-12 MCID. Level of evidence: retrospective case series: level IV.

Low rate of high-level athletes maintained a return to pre-injury sports two years after arthroscopic treatment for femoroacetabular impingement syndrome

PURPOSE

The aim was to investigate the rate of athletes still active at their pre-injury sports level two years after arthroscopic treatment for femoroacetabular impingement syndrome (FAIS), and examine this between different sports and gender, and its correlation to patient-reported outcome measures (PROMs).

METHOD

High-level athletes planned for arthroscopic treatment for FAIS were included prospectively in a Swedish hip arthroscopy registry between 2011 and 2017, and 717 met the inclusion criteria. Self-reported sporting activity was recorded preoperatively. The subjects answered PROMs, including the HSAS, iHOT-12 and HAGOS pre- and postoperatively.

RESULTS

A total of 551 athletes (median age 26, interquartile range 20-34 years; 23% women) had completed follow-up PROMs, at mean 23.4 ± 7.2 months postoperatively. In total, 135 (24.5%) were active at their pre-injury level of sports at follow-up (RTS^pre). Athletes ≤30 years at time of surgery (n = 366; median age 22 years) had higher rate of RTS^pre (31.4%) compared with athletes > 30 years (n = 185; median age 40 years) (10.8%; p < 0.001). All athletes had improvements in iHOT-12 and HAGOS, two years postoperatively (p < 0.001), while RTS^pre athletes reported significantly better PROMs, pre- and postoperatively, and had greater improvements two years postoperatively, compared with athletes not active at pre-injury level.

CONCLUSION

Only 25% of all high-level athletes and 31% of athletes ≤30 years were still active at their pre-injury sports level two years after arthroscopic treatment for FAIS. Athletes still active had significantly and clinically greater improvement regarding hip symptoms, function and quality of life, as compared with athletes not active at pre-injury level, two years postoperatively.

Mismatch between expectations and physical activity outcomes at six months following hip-arthroscopy: A qualitative study

OBJECTIVE

To explore factors influencing participation in physical activity for young to middle-aged patients at six months post-hip arthroscopy.

DESIGN

Qualitative study.

SETTING

Three specialist surgical centres in Australia.

PARTICIPANTS

Seventeen adults aged 18-50 years.

MAIN OUTCOME MEASURES

Individual semi-structured interviews were undertaken and transcribed verbatum. Inductive analysis of the data was undertaken, with themes identified through an iterative coding process.

RESULTS

Four key themes emerged from the analysis: 1) an evident mismatch between expectations and actual progress of physical activity during the first six months post-arthroscopy; 2) physical activity levels vary widely at six months post-operatively; 3) evidence of suboptimal psychological readiness to return to sport and an associated emotional toll; and 4) the influence of available support and information on post-operative physical activity.

CONCLUSIONS

This qualitative study has provided in-depth perspectives on recovery after hip arthroscopy. Clear opportunities exist to: 1) help patients develop realistic post-operative goals; 2) provide timely patient education and support; and 3) facilitate an effective transition to desired physical activity.

Despite patient-reported outcomes improve, patients with femoroacetabular impingement syndrome do not increase their objectively measured sport and physical activity level 1 year after hip arthroscopic surgery. Results from the HAFAI cohort

PURPOSE

Patients with femoroacetabular impingement syndrome (FAIS) are young and middle-aged persons living physically active lives including sports activities. However, measurements of the physical activity level before and after hip arthroscopic surgery in patients with FAIS using both self-reported and objective accelerometer-based measures are lacking. Furthermore, comparing patients with a reference group of persons reporting no hip problems and conducting subgroup analyses investigating changes in physical activity level and self-reported outcomes according to pre-surgery activity level may further highlight the activity pattern for patients.

METHODS

Sixty patients with FAIS eligible for hip arthroscopic surgery were consecutively included in a prospective cohort study (HAFAI cohort) together with 30 reference persons reporting no hip problems. Participants completed the Copenhagen Hip and Groin Outcome Score (HAGOS) together with questions regarding their sports activities. Furthermore, participants wore a three-axial accelerometer for five consecutive days during waking hours. The accelerometer-based data were analysed and presented as total activity and type, frequency and duration of activities.

RESULTS

Patients experienced significant and clinically relevant changes in all HAGOS scores. 88% of patients participated in some kind of sports activity 1 year after surgery. Overall, objectively measured physical activity did not change from before to 1 year after surgery. However, subgroup analyses of the most sedentary patients preoperatively revealed significant changes towards a more active pattern. Compared to reference persons, patients performed less bicycling and running.

CONCLUSION

Despite clinically relevant changes in self-reported outcomes, patients did not increase their overall physical activity level 1 year after surgery. Physical activity levels were lower in patients than in the reference group and patients continued bicycling and running less compared with the reference group.

LEVEL OF EVIDENCE

II.

No association between femoral or acetabular angles and patient-reported outcomes in patients with femoroacetabular impingement syndrome-results from the HAFAI cohort

Patients with femoroacetabular impingement syndrome (FAIS) are diagnosed using imaging, but detailed description especially the acetabular shape is lacking and may help give more insight to the pathogenesis of FAIS. Furthermore, associations between patient-reported outcomes (PROs) and the radiological angles might highlight which radiological angles affect outcomes experienced by the patients. Hence, the aims of this study were (i) to describe computer tomography (CT) acquired angles in patients with FAIS and (ii) to investigate the association between radiological angles and the Copenhagen Hip and Groin Outcome Score (HAGOS) in patients with FAIS. Patients scheduled for primary hip arthroscopic surgery for FAIS were included. Based on CT, following angles were measured before and 1 year after surgery; femoral anteversion, alpha, lateral centre edge, acetabular index, anterior sector, posterior sector and acetabular anteversion. All patients completed the HAGOS. Sixty patients (63% females) aged 36 ± 9 were included. One year after surgery, significant alterations in the alpha angle and the acetabular index angle were found. Neither baseline PROs nor changes in PROs were associated with the radiological angles or changes in angles. Since neither changes in CT angles nor baseline scores were associated with HAGOS, the improvements felt by patients must origin from somewhere else. These findings further underlines that morphological changes seen at imaging should not be treated arthroscopically without a patient history of symptoms and clinical findings.

Defining Variations in Outcomes of Hip Arthroscopy for Femoroacetabular Impingement Using the 12-Item International Hip Outcome Tool (iHOT-12)

BACKGROUND

As health care moves toward a value-based payment system, it will be important that patient-reported outcome measures (PROMs) define variations in outcome over a follow-up period that allows a patient to achieve maximal improvement. Although there is evidence to support the use of PROMs to assess postoperative outcomes after hip arthroscopy, there is limited information available to assess for variations in outcome at a 2-year follow-up interval.

PURPOSE

To identify substantial clinical benefit (SCB) and patient acceptable symptom state (PASS) cutoff scores for the 12-item International Hip Outcome Tool (iHOT-12) that define patient status across a spectrum of potential outcomes after hip arthroscopy at a 2-year follow-up interval.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

These data were collected from a research registry of patients having hip arthroscopy for femoroacetabular impingement and/or chondrolabral pathology. On initial assessment and 2 years (±2 months) postoperatively, patients completed the iHOT-12, and categorical self-rating of function. They also completed a visual analog scale of postoperative satisfaction. Receiver operator characteristic analysis was performed to determine absolute SCB iHOT-12 scores associated with an "abnormal,""nearly normal," or "normal" self-report of function, and PASS scores for those reporting at least 50%, at least 75%, or 100% satisfaction with their surgery.

RESULTS

Out of 723 eligible patients, 658 (91%) met the inclusion criteria. The patients consisted of 462 (70%) women and 196 (30%) men, with a mean age of 35.3 years (SD, 13 years) and mean follow-up of 722 days (SD, 69 days). Absolute SCB and PASS iHOT-12 scores ranging from 38 to 86 were accurate in identifying those who had abnormal, nearly normal, and normal self-reported function and were at least 50%, at least 75%, and 100% satisfied with surgery. The areas under the curve were >0.70, with sensitivity and specificity values ranging from 0.78 to 0.92.

CONCLUSION

This study provides absolute SCB and PASS iHOT-12 cutoff scores that can be used to define variations in 2-year (±2 months) outcomes in patients after hip arthroscopy for femoroacetabular impingement and chondrolabral pathology. iHOT-12 scores of 38, 60, and 86 were associated with abnormal, nearly normal, and normal reports of function respectively, with scores of 60, 71, and 86 associated with at least 50%, at least 75%, and 100% satisfaction after surgery, respectively.

A tiered system using substantial clinical benefit and patient acceptable symptomatic state scores to evaluate 2-year outcomes of hip arthroscopy with the Hip Outcome Score

There is no information to define variations in hip arthroscopy outcomes at 2-year follow-up using the Hip Outcome Score (HOS). To offer a tiered system using HOS absolute substantial clinical benefit (SCB) and patient acceptable symptomatic state (PASS) scores for 2-year hip arthroscopy outcome assessment. This was a retrospective review of patients having hip arthroscopy for femoroacetabular impingement and/or chondrolabral pathology. On initial assessment and 2 years (±2 months) post-operatively, subjects completed the HOS activity of daily living (ADL) and Sports subscales, categorical self-rating of function and visual analog scale for satisfaction with surgery. Receiver operator characteristic analysis identified absolute SCB and PASS HOS ADL and Sports subscale scores. Subjects consisted of 462 (70%) females and 196 (30%) males with a mean age of 35.3 years [standard deviation (SD) 13] and mean follow-up of 722 days (SD 29). SCB and PASS scores for the HOS ADL and Sports subscales were accurate in identifying those at a ‘nearly normal’ and ‘normal’ self- report of function and at least 75% and 100% levels of satisfaction (area under the curve >0.70). This study provides tiered SCB and PASS HOS scores to define variations in 2-year (±2 months) outcome after hip arthroscopy. HOS ADL subscale scores of 84 and 94 and Sports subscale scores of 61 and 87 were associated with a ‘nearly normal’ and ‘normal’ self-report of function, respectively. HOS ADL subscale scores of 86 and 94 and Sports subscale score of 74 and 87 were associated with being at least 75% and 100% satisfied with surgery, respectively. Level of evidence: III, retrospective comparative study.

Physical Activity Following Hip Arthroscopy in Young and Middle-Aged Adults: A Systematic Review

Background

Hip arthroscopy is a common surgical intervention for young and middle-aged adults with hip-related pain and dysfunction, who have high expectations for returning to physical activity following surgery. The purpose of this review was to evaluate the impact of hip arthroscopy on physical activity post-arthroscopy.

Methods

A systematic search of electronic databases was undertaken in identifying studies from January 1st 1990 to December 5th 2019. The search included English language articles reporting physical activity as an outcome following hip arthroscopy in adults aged 18-50 years. Quality assessment, data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 234) were assessed for eligibility following screening of titles and abstracts (n = 2086), yielding 120 studies for inclusion. The majority (86%) of the studies were level 4 evidence. One study reported objective activity data. The most frequently occurring patient-reported outcome measure was the Hip Outcome Score-sport-specific subscale (HOS-SS, 84% of studies). Post--arthroscopy improvement was indicated by large effect sizes for patient-reported outcome measures (standard paired difference [95% confidence interval] −1.35[−1.61 to −1.09] at more than 2 years post-arthroscopy); however, the majority of outcome scores for the HOS-SS did not meet the defined level for a patient-acceptable symptom state.

Conclusion

The current level of available information regarding physical activity for post arthroscopy patients is limited in scope. Outcomes have focused on patients’ perceived difficulties with sport-related activities with a paucity of information on the type, quality and quantity of activity undertaken.

Level of Evidence

Level IV, systematic review of Level 2 through to Level 4 studies

Corrections in alpha angle following two different operative approaches for CAM-type femoral acetabular impingement - Ganz surgical hip dislocation vs anterior mini-open

BACKGROUND

Femoroacetabular impingement (FAI) is a predisposing factor for secondary osteoarthritis of the hip joint. The two extensively described impingement mechanisms of FAI are CAM and Pincer-type. Initially managed conservatively, operative intervention should be offered to the persistently symptomatic patient. The measurement of the alpha angle is considered a standard method of assessing the severity of pathology in Cam-type FAI on pre-operative plain radiographs. The radiological correction of the alpha angle has not been previously compared between different surgical approaches. We hypothesize that there is no difference in alpha angle correction between Ganz surgical hip dislocation and the anterior mini-open approach.

AIM

To compare the magnitude of alpha angle correction achieved by using the Ganz surgical hip dislocation and the anterior mini-open approach.

METHODS

This is a retrospective study assessing seventy-nine patients identified in a 5-year period. These patients had preoperative radiographic evidence of FAI and underwent surgery by a single surgeon at our institution, a tertiary care center. Patients with missing radiographic documentation, radiographs with insufficient quality which then precluded accurate measurement of the angle α, a diagnosed congenital condition, isolated type II pathology (Pincer), and history of prior surgery were excluded from the study. Either the Ganz surgical hip dislocation or the anterior mini open approach was used. Postoperative radiographic evaluation of the alpha angle between the two surgical methods was done and corrected for age and gender using two-sample t-tests and Chi-square analyses.

RESULTS

A total of 79 patients met the inclusion and exclusion criteria. Forty-seven males (mean age of 35.3, range 16-53) and 32 females (mean age 36.7, range 16-60) were enrolled. Forty-seven patients underwent the anterior mini-open approach, and 32 underwent the Ganz surgical hip dislocation. There were no significant differences in age between the two surgical groups or in pre- and post-operative alpha angles based on patient gender. The mean pre-operative alpha angle for the Ganz surgical hip dislocation group was 88.0 degrees (SD 12.3) and 99.4 degrees (SD 7.2) for the anterior mini-open group. Mean post-operative angles were 49.9 degrees (SD 4.3) for the Ganz surgical hip dislocation and 43.8 (SD 4.3) degrees for the anterior mini-open group. There was a statistically significant difference in patient’s pre-operative and post-operative angles (P = 0.000) with both surgical approaches.

CONCLUSION

Statistically significant decreases in alpha angle were noted for both surgical techniques, with larger decreases seen in the anterior mini-open group.

Good 5-year outcomes after arthroscopic treatment for femoroacetabular impingement syndrome

PURPOSE

The purpose of the present study was to evaluate the outcome of arthroscopic treatment for femoroacetabular impingement (FAI) syndrome 5 years post-surgery using patient-reported outcome scores (PROMs) validated for a young and active population with hip complaints.

METHODS

Patients were prospectively included in the study. A total of 184 patients [males = 110 (59.8%), females = 74 (40.2%)], with mean age 38.0, underwent arthroscopic treatment for FAI syndrome and were analysed. Preoperatively and at the 5-year follow-up, patients completed a set of self-administered web-based PROMs consisting of the International Hip Outcome Tool (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS), the Hip Sports Activity Scale (HSAS), the EuroQoL-5 Dimension Questionnaire (EQ-5D), the EQ-Visual Analogue Scale (VAS) and the VAS for overall hip function and overall satisfaction. The Wilcoxon signed rank test was used to compare preoperative PROM values with those obtained at the 5-year follow-up.

RESULTS

A comparison of preoperative PROM scores and those obtained at the 5-year follow-up revealed statistically significant improvements for all outcome scores (p < 0.05), except for the HSAS score, which were unchanged; iHOT-12 (42.9 vs 67.2), HAGOS different subscales (50.2 vs 69.6, 55.7 vs 76.1, 59.2 vs 72.3, 41.1 vs 66.4, 30.8 vs 60.2, 31.6 vs 60.4), EQ-5D (0.570 vs 0.742), EQ-VAS (66.6 vs 74.4), HSAS (3.13 vs 3.17) and VAS for overall hip function (47.9 vs 69.2). At the 5-year follow-up, 154 patients reported that they were satisfied with surgery (84.6%). Survivorship at the 5-year follow-up was 86.4%.

CONCLUSION

Arthroscopic treatment for FAI syndrome yields good patient-reported outcome at the 5-year follow-up.

LEVEL OF EVIDENCE

II.

Arthroscopic Femoral Osteochondroplasty With Capsular Plication for Osteochondroma of the Femoral Neck

Osteochondromas of the femoral neck are a rare but challenging problem because of their distal location, which is difficult to access arthroscopically. Traditional methods of osteochondroma resection used invasive open approaches to manage these lesions. More recently, advances in hip arthroscopy have allowed expanded treatment of extra-articular hip conditions with a minimally invasive approach. Reports have described the use of hip arthroscopy for osteochondroma removal; however, surgical techniques for the procedure have yet to be described. We describe a technique for arthroscopic resection of a femoral neck osteochondroma using an extended capsulotomy and osteochondroplasty with subsequent capsular plication. This technique uses contemporary hip arthroscopic techniques and constitutes a safe and effective approach to addressing this rare intra-articular pathology of the hip.

Danish Hip Arthroscopy Registry: predictors of outcome in patients with femoroacetabular impingement (FAI)

PURPOSE

Predictors of outcome after femoroacetabular impingement (FAI) surgery are not well-documented. This study presents data from the Danish Hip Arthroscopy Registry (DHAR) for such analyses. The purpose of this study was to identify predictors of poor outcome after FAI surgery in a Danish FAI population. The primary hypothesis was that older patients, patients with severe cartilage damage and female patients might have inferior outcome results compared with younger patients, patients with minor cartilage damage and male patients.

METHODS

Radiological and surgical data as well as patient-reported outcome measures (PROM) from FAI patients in DHAR between January 2012 and May 2015 were collected. PROMs consisting of Copenhagen Hip and Groin Outcome Score (HAGOS), quality of life (EQ-5D), Hip Sports Activity Scale (HSAS) and Numeric Rating Scale (NRS) pain scores were assessed. The patients were divided into three age groups (< 25, 25-39 and ≥ 40 years). Cartilage injuries were classified according to International Cartilage Repair Society (ICRS) (femoral side) and modified Becks (acetabular side) classifications. A non-parametric statistic method was used to analyze the differences between the preoperative and postoperative PROM values.

RESULTS

Data from 2054 FAI procedures in DHAR was collected. 53% of the procedures were done in female patients. All HAGOS sub-scales, EQ-5D, HSAS and NRS pain (rest and walk) demonstrated significant improvements in all age groups at follow-up. Comparison between age groups demonstrated poorer outcomes in both older age groups when compared with the < 25 years age group at 1- and 2-year follow-ups. Higher degrees of femoral and acetabular cartilage injury did have a negative influence on outcome at follow-up. Comparison between genders demonstrated lower preoperative outcomes in females and lower outcome score (HSAS) 1 and 2 years after FAI surgery.

CONCLUSIONS

Age above 25 and major cartilage injury might negatively affect the outcome of surgery, however, gender could not be identified as a negative predictor of clinical outcome after FAI surgery, but might negatively affect sports participation in females.

LEVEL OF EVIDENCE

III, prospective cohort study.

Demographic and Radiographic Factors Associated With Intra-articular Hip Cartilage Injury: A Cross-sectional Study of 1511 Hip Arthroscopy Procedures

BACKGROUND

Moderate to severe (grade 3-4) hip joint cartilage injury seems to impair function in patients with femoroacetabular impingement syndrome.

PURPOSE

To investigate whether demographic and radiographic factors were associated with moderate to severe hip joint cartilage injury.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients were identified in the Danish Hip Arthroscopy Registry. The outcome variables were acetabular cartilage injury (modified Beck grade 0-2 vs 3-4) and femoral head cartilage injury (International Cartilage Repair Society grade 0-2 vs 3-4). Logistic regressions assessed the association with the following: age (<30 vs 30-50 years); sex; sport activity level (Hip Sports Activity Scale); alpha angle (AA) assessed as normal (AA <55°), cam (55°≤ AA <78°), or severe cam (AA ≥78°); lateral center-edge angle (LCEA) assessed as normal (25°≤ LCEA ≤ 39°), pincer (LCEA >39°), or borderline dysplasia (LCEA <25°); joint space width (JSW) assessed as normal (JSW >4.0 mm), mild reduction (3.1 mm ≤ JSW ≤ 4.0 mm), or severe reduction (2.1 mm ≤ JSW ≤ 3.0 mm).

RESULTS

A total of 1511 patients were included (mean ± SD age: 34.9 ± 9.8 years). Male sex (odds ratio [OR], 4.42), higher age (OR, 1.70), increased AA (cam: OR, 2.23; severe cam: OR, 4.82), and reduced JSW (mild: OR, 2.04; severe: OR, 3.19) were associated (P < .05) with Beck grade 3-4. Higher age (OR, 1.92), increased Hip Sports Activity Scale (OR, 1.13), borderline dysplasia (OR, 3.08), and reduced JSW (mild: OR, 2.63; severe: OR, 3.04) were associated (P < .05) with International Cartilage Repair Society grade 3-4.

CONCLUSION

Several demographic and radiographic factors were associated with moderate to severe hip joint cartilage injury. Most notably, increased cam severity and borderline dysplasia substantially increased the risk of grade 3-4 acetabular and femoral head cartilage injury, respectively, indicating that specific deformity may drive specific cartilage injury patterns in the hip joint.

The association between specific sports activities and sport performance following hip arthroscopy for femoroacetabular impingement syndrome: A secondary analysis of a cross-sectional cohort study including 184 athletes

The main purpose of this secondary analysis was to compare the proportion of athletes with moderate-to-extreme difficulties in eight specific sport activities in athletes with optimal versus impaired sport performance after a hip arthroscopy for femoroacetabular impingement syndrome. Subjects were identified in a nationwide registry and invited to answer a return to sport and performance questionnaire, and the Copenhagen Hip and Groin Outcome Score Sport subscale investigating difficulties in eight specific sports activities (HAGOS sport items) as; none, mild, moderate, severe or extreme. Subjects were divided into two groups based on sport performance (optimal or impaired). The proportion of athletes with none-to-mild versus moderate-to-extreme difficulties in the eight specific sport activities was compared between groups. The association between difficulties in sport activities and sport performance were investigated using logistic regression analysis. One hundred and eighty-four athletes (31 athletes with optimal and 153 athletes with impaired sport performance) were included at a mean follow-up of 33.1 ± 16.3 months. Up to six athletes (<20%) with optimal sport performance had moderate-to-extreme difficulties in sport activities. Contrary, 43–108 athletes (28.1–70.6%) with impaired performance had moderate-to-extreme difficulties in sport activities. Furthermore, moderate-to-extreme difficulties in HAGOS sport items: ‘running as fast as you can’ and ‘kicking, skating etc.’ increased the odds (14.7 and 6.1 times, respectively) of having impaired sport performance. Many athletes with impaired sport performance reported moderate-to-extreme difficulties in sport activities, specifically moderate-to-extreme difficulties in ‘running as fast as you can’ and ‘kicking, skating etc.’ were associated with patients having impaired sport performance.

Quality Assessment of Prospective Cohort Studies Evaluating Arthroscopic Treatment for Femoroacetabular Impingement Syndrome: A Systematic Review

Background

Femoroacetabular impingement (FAI) syndrome is a cause of pain and reduced range of motion in the hip joint. Given the limited number of randomized controlled trials, prospective cohort studies constitute the dominant part of the available prospective evidence evaluating relevant clinical outcomes after arthroscopic hip surgery for FAI.

Purpose

To assess the methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI and to determine whether there has been an improvement in methodological quality over time.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic literature search was performed in PubMed, Embase (OvidSP), and the Cochrane Library. Included studies were clinical prospective cohort studies of primary arthroscopic surgery for cam and/or pincer morphology FAI. Methodological quality was assessed with the Methodological Index for Non-randomized Studies (MINORS). The mean MINORS score for studies published during the first 5 years of the period was compared with those published during the last 5 years to evaluate methodological improvement over time. The methodological quality of randomized controlled trials was also assessed with the Coleman Methodology Score.

Results

The search yielded 53 studies. There were 34 noncomparative studies, 15 nonrandomized comparative studies, and 4 randomized controlled trials. The included studies were published between 2008 and 2017. The mean ± SD MINORS score for noncomparative and comparative studies was 10.4 ± 1.4 of 16 possible and 18.7 ± 2.0 of 24 possible, respectively. The mean Coleman Methodology Score for randomized controlled trials was 79.0 ± 7.0 of 100 possible.

Conclusion

The methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI is moderate for comparative and noncomparative studies. Common areas for improvement include unbiased assessment of study endpoints and prospective sample-size calculations. Despite an increase in the number of published studies, an improvement in methodological quality over time was not observed.

Health-Related Quality of Life After Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review and Meta-analysis

CONTEXT

Hip pain from femoroacetabular impingement (FAI) can impair health-related quality of life (HRQL) but can be treated via hip arthroscopy techniques.

OBJECTIVE

To systematically assess the HRQL outcomes after arthroscopic management of FAI.

DATE SOURCES

Three online databases (EMBASE, PubMed, and Ovid [MEDLINE]) were searched for relevant literature from database inception until June 2018 and screened by 2 reviewers independently and in duplicate.

STUDY SELECTION

Level I to IV English studies that investigated HRQL outcomes after hip arthroscopy were included. Data for generic and hip-specific HRQL outcomes were collected. Mean differences were plotted in a forest plot when possible.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

A total of 29 studies were included for assessment. Of the 6476 patients (6959 hips), the mean age was 32 years (range 9-79 years) and 50.7% were female. Significant improvements were reported in all studies assessing generic HRQL outcomes, including the 12-Item Short Form Health Survey (range of mean postoperative scores, 82.2-89.8), and EuroQOL-5D scores (range of mean postoperative scores, 0.74-0.87) between 12 and 24 months postoperatively. Significant improvements were similarly identified in the hip-specific HRQL outcomes scores, with the majority of studies also reporting improvement between 12 and 24 months postoperatively. Mean improvement in International Hip Outcome Tool-33 scores from preoperative values to postoperative values ranged from 22.7 to 43.2 ( I2 = 44%), for studies with follow-up between 12 and 24 months.

CONCLUSION

Hip arthroscopy can lead to significant improvement in generic and hip-specific HRQL outcomes at 12 to 24 months postoperatively in patients with FAI who do not have advanced hip osteoarthritis. Confirmatory, high-quality, prospective studies are warranted to compare this observed improvement with other treatment modalities for FAI and to determine long-term outcomes.

Prior arthroscopic treatment for femoro-acetabular impingement does not compromise hip arthroplasty outcomes: a matched-controlled study with minimum two-year follow-up

BACKGROUND

Femoro-acetabular impingement (FAI) is known as a predisposing factor in the development of osteoarthritis of the hip. In order to treat this condition, hip arthroscopy is considered as the gold standard in recent years. The number of performed hip arthroscopies has risen immensely. However, a number of patients with poor outcome after hip arthroscopy will require further surgical intervention, sometimes even conversion into THR (total hip replacement). The purpose of this study was to analyze whether outcomes of THR are affected by prior hip arthroscopy in these patients.

METHODS

Patients who underwent a THR following an ipsilateral hip arthroscopy were matched to a control group of THR patients with no history of prior ipsilateral hip surgery. Matching criteria were age, sex, body mass index, implants used, and surgical approach. Modified Harris Hip Score, surgical time, presence of heterotopic ossification, and post-operative complication were prospectively compared at a minimum two year follow-up.

RESULTS

Thirty-three THR after hip arthroscopy patients were successfully matched to control patients. There was no significant difference in mHHS between both groups (FAI treatment group 92.8 vs. control group 93.8, p = 0.07). However, FAI treatment group showed a lower mHHS score pre-operatively (48 vs. 60, p = 0.002). There was no significant difference in surgical time and post-operative complication rate. No heterotopic ossification could be found.

CONCLUSION

A prior hip arthroscopy has no affect to clinical outcomes of subsequent THR.

Is hip muscle strength normalised in patients with femoroacetabular impingement syndrome one year after surgery?: Results from the HAFAI cohort

OBJECTIVES

Little is known about hip function after hip arthroscopic surgery in patients with femoroacetabular impingement syndrome. Hence, the aim of the study was (1) to investigate changes in hip muscle strength from before to one year after hip arthroscopic surgery, (2) to compare patients with a reference group.

DESIGN

Cohort study with a cross-sectional comparison.

METHODS

Before and after hip arthroscopic surgery, patients underwent hip muscle strength testing of their hip flexors and extensors during concentric, isometric and eccentric contraction in an isokinetic dynamometer. Reference persons with no hip problems underwent tests at a single time point. Participants completed completed the Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire and physical capacity (stair climbing loaded and unloaded, stepping loaded and unloaded and jumping) tests.

RESULTS

After surgery, hip flexion strength improved during all tests (6-13%, p<0.01) and concentric hip extension strength improved (4%, p=0.002). Hip flexion and extension strength was lower for patients than for reference persons (9-13%, p<0.05) one year after surgery. Higher hip extension strength after surgery was associated with better patient reported outcomes. Patients, who were unable to complete at minimum one test of physical capacity, demonstrated significantly weaker hip muscle strength. Compared with their healthy counterparts, female patients were more impaired than male patients.

CONCLUSIONS

One year after surgery, patients improved their maximal hip muscle strength. When compared to reference persons, maximal hip muscle strength was still impaired.

Patient-Reported Outcomes Within the First Year After Hip Arthroscopy and Rehabilitation for Femoroacetabular Impingement and/or Labral Injury: The Difference Between Getting Better and Getting Back to Normal

BACKGROUND

The Copenhagen Hip and Groin Outcome Score (HAGOS) was recently found valid, reliable, and responsive for patients undergoing hip arthroscopy. However, it is currently unknown to what degree patients undergoing hip arthroscopy improve and/or normalize their HAGOS result within the first year after surgery.

PURPOSE

First, to use HAGOS to evaluate clinical outcomes at 3, 6, and 12 months after hip arthroscopy for femoroacetabular impingement (FAI) and/or labral injury and compare the HAGOS results with the modified Harris Hip Score (mHHS). Second, to explore how many patients would (a) improve to a degree of minimal clinical importance (MIC) and (b) obtain scores within the reference intervals of healthy controls.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

From September 2011 to March 2014, 97 consecutive patients [56 females (mean age, 38 years; range, 17-60 years) and 41 males (mean age, 37 years; range, 19-59 years)] underwent first-time hip arthroscopy for FAI and/or labral injury. Standardized postoperative rehabilitation instructions were provided. HAGOS (0-100 points) and mHHS (0-100 points) values were obtained preoperatively and again postoperatively at 3, 6, and 12 months. Furthermore, 158 healthy controls, matched on age and sex, were included to obtain HAGOS and mHHS reference values for comparison. Minimal important change was determined by using the 0.5 SD of the baseline values for HAGOS and mHHS.

RESULTS

Improvements for all HAGOS subscales and mHHS results were seen at 3 months ( P < .001). Further improvements were seen only for HAGOS Sport and Recreation (Sport/Rec) and Participation in Physical Activities (PA) subscales between 3 and 12 months ( P < .05) but not for HAGOS Pain, Symptoms, Activities of Daily Living (ADL), or Hip-Related Quality of Life (QOL) subscales or the mHHS. Furthermore, on HAGOS Sport/Rec, PA, and QOL subscales, patients reached scores of only 54 to 70 points 1 year after surgery. At the individual level, up to 70% of the patients experienced minimal important improvements during the first year after surgery, but only up to 38% and 36% of patients reached a score within the reference interval of HAGOS and mHHS, respectively.

CONCLUSION

Statistically and clinically relevant improvements in HAGOS and mHHS results after hip arthroscopy and rehabilitation can be seen at 3 months and up to 1 year. However, specific HAGOS subscales suggest that a patient's ability to function and participate in sport and physical activity is still markedly reduced 1 year after surgery. Furthermore, the majority of patients undergoing hip arthroscopy cannot expect to reach the level of the healthy population on self-reported pain and function within the first year after surgery.

Return to Sport and Performance After Hip Arthroscopy for Femoroacetabular Impingement in 18- to 30-Year-Old Athletes: A Cross-sectional Cohort Study of 189 Athletes

BACKGROUND

A recent systematic review found that 87% of athletes return to sport after hip surgery for femoroacetabular impingement syndrome. However, the proportion of athletes returning to preinjury sport at their preinjury level of sport is less clear.

PURPOSE

The main purpose of this study was to determine the rate of athletes returning to preinjury sport at preinjury level including their associated sports performance after hip arthroscopy for femoroacetabular impingement syndrome. Furthermore, self-reported hip and groin function was investigated.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Eligible subjects were identified in the Danish Hip Arthroscopy Registry. A self-reported return to sport questionnaire was used to collect data after hip arthroscopy. If athletes reported they were engaged in preinjury sport at their preinjury level, the associated sports performance and participation were assessed as either (1) optimal sports performance including full sports participation; (2) impaired sports performance, but full sports participation; or (3) impaired sports performance including restricted sports participation. Self-reported hip and groin function was assessed for all athletes by use of the Copenhagen Hip and Groin Outcome Score.

RESULTS

The study included 189 athletes (mean ± SD age at follow-up, 26.9 ± 3.4 years) at a mean ± SD follow-up of 33.1 ± 16.3 months after surgery. At follow-up, 108 athletes (57.1%) were playing preinjury sport at preinjury level, whereas the remaining 81 athletes (42.9%) failed to return to preinjury sport at preinjury level. Of the 108 athletes engaged in their preinjury sport at preinjury level at follow-up, 32 athletes (29.6%) reported optimal sports performance including full sports participation, corresponding to 16.9% of the study sample. Better self-reported hip and groin function was observed in athletes who were engaged in preinjury sport at preinjury level compared with athletes who were not.

CONCLUSION

Fifty-seven percent of athletes returned to preinjury sport at their preinjury level. This is considerably lower than a previously reported return to sport rate of 87% and may reflect that the present study used a clear and strict definition of return to sport. Of note, only one-third of athletes who returned to preinjury sport at preinjury level reported their sports performance to be optimal, corresponding to 16.9% of the study sample. Better self-reported hip and groin function was observed in athletes who were playing preinjury sport at preinjury level compared with athletes who were not.

Time Required to Achieve Minimal Clinically Important Difference and Substantial Clinical Benefit After Arthroscopic Treatment of Femoroacetabular Impingement

BACKGROUND

Minimal clinically important difference (MCID) defines the minimum degree of quantifiable outcome improvement that a patient perceives as the result of an intervention or in the process of healing. Substantial clinical benefit (SCB) defines the amount of quantifiable outcome improvement that is needed for a patient to feel substantially better. Little is known about when clinically significant outcome improvement is achieved.

PURPOSE

To investigate the time-dependent nature of MCID and SCB after hip arthroscopy for femoroacetabular impingement (FAI).

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

An institutional hip preservation registry was queried. The modified Harris Hip Score, Hip Outcome Score, and 33-item International Hip Outcome Tool (iHOT-33) were administered to patients undergoing hip arthroscopy for FAI. Follow-up times for outcome measures were classified into 3 periods: 5 to 11 months (6 months), 12 to 23 months (1 year), and 24 to 35 months (2 years). Cumulative probabilities for achieving MCID and SCB were calculated with Kaplan-Meier survival curve analysis and interval censoring. A Weibull parametric regression analysis evaluated the odds of achieving earlier MCID.

RESULTS

A total of 719 patients undergoing primary hip arthroscopy were included. The mean ± SD age was 32.5 ± 10.5 years, and the majority were female (n = 380, 52.9%). Across all 4 outcome instruments, patients had the highest probability for achieving MCID and SCB by the 6-month postoperative period. The iHOT-33 demonstrated the highest probability for capturing MCID and SCB improvement at each of the 3 periods, with 76.0%, 84.8%, and 93.6% achieving MCID by 6 months, 1 year, and 2 years, respectively. Similarly, the probabilities of achieving SCB on the iHOT-33 were as follows: 57.1%, 68.0%, and 71.7%. A similar trend was demonstrated across other outcome tools. Older male patients and those with Outerbridge classification 1 to 4 (vs grade 0) had a significantly increased risk for taking a longer time to achieve MCID and SCB. Additionally, patients with higher preoperative outcome scores took a longer time to achieve MCID and SCB.

CONCLUSION

At least half of patients treated with hip arthroscopy for FAI achieve MCID and SCB within the first 6 months after the procedure. However, clinically significant outcome improvement continues to be attained until 2 years postoperatively. Female patients, younger individuals, and those without chondral defects achieve faster clinical outcome improvement. These findings can be helpful for establishing shared decision-making aids and follow-up guidelines for arthroscopic treatment of FAI.

Experience and outcome data of the British non-arthroplasty hip registry

INTRODUCTION

The non-arthroplasty hip registry (NAHR) is a United Kingdom national register that monitors the efficacy of hip preservation surgery. We aim to highlight early experiences of incorporating the NAHR into our practice at a tertiary centre.

METHODS

Between December 2013 and February 2015, 381 patients were identified on the NAHR database that had undergone non-arthroplasty hip surgery. Patient-related outcome measures EuroQuol 5D-5L (EQ-5D) and the International Hip Outcome Tool 12 (iHOT-12) were recorded at baseline and 6 months.

RESULTS

The 289 arthroscopic surgeries showed a statistical significant difference (p<0.05) in iHOT-12 for both males (45.21-65.07) and females (34.57 to 55.53), and in EQ-5D for both males (0.59-0.75) and females (0.56-0.65). The 92 open procedures showed a statistical significant difference (p<0.05) in both iHOT-12 (31.71-62.42) and EQ-5D (0.54-0.68).

CONCLUSIONS

Overall our results from the NAHR indicate hip preservation surgery is effective at relieving pain and improving quality of life in the short term.

Multicentre study on capsular closure versus non-capsular closure during hip arthroscopy in Danish patients with femoroacetabular impingement (FAI): protocol for a randomised controlled trial

INTRODUCTION

Hip arthroscopy has become a standard procedure in the treatment of hip joint pain not related to osteoarthritis or dysplasia in the young and active patient. There has been increasing focus on the contribution of the hip capsule to function and on stability following hip arthroscopy. It has been suggested that capsular closure after hip arthroscopy may prevent microinstability and macroinstability of the hip joint and reduce revision rate. However, it remains unknown whether capsular closure should be performed as a standard procedure when performing hip arthroscopies, especially in patients without additional risk factors for instability such as hypermobility or dysplasia of the hip. We hypothesised that capsular closure will lead to a superior outcome in hip arthroscopy for femoroacetabular impingement syndrome (FAIS) compared with non-capsular closure.

METHODS AND ANALYSIS

In this randomised controlled, multicentre trial, 200 patients scheduled for hip arthroscopy for FAIS will be cluster randomised into one of two groups (group I: hip arthroscopy without capsular closure, group II: hip arthroscopy combined with capsular closure). Inclusion criteria are: age between 18 years and 50 years and FAIS according to the Warwick agreement. Exclusion criteria are: previous hip surgery in either hip, previous conditions of Legg-Calvé-Perthes or slipped capital femoral epiphysis, malignant disease, recent hip or pelvic fractures, arthritis, Ehlers-Danlos or Marfan disease, recent (within 6 weeks) application of intra-articular corticosteroids, language problems of any kind, and radiological signs of osteoarthritis, acetabular dysplasia or acetabular retroversion. Surgery will be performed in Denmark at four centres by four surgeons, all performing an interportal capsulotomy and closure with at least two absorbable sutures. Patients in both groups, who are blinded for the intervention, will receive the same standardised rehabilitation programme. As primary outcome scores, HAGOS (sport) will be used with HAGOS (symptoms, pain, function in daily living, participation in physical activities and hip and/or groin-related quality of life), Hip Sports Activity Scale, short validated version of the International Hip Outcome Tool, EQ-5D, Visual Analogue Scale for pain, complications and reoperation rate as secondary outcome tools. Using HAGOS (sport) as primary outcome parameter the power analysis required a minimum of 84 individuals per group. Together with a clinical examination performed by the patient's surgeon 1 year after surgery, patient reported outcome measures will be completed preoperatively, as well as at 3 months, 1 year, 2 years and 5 years postoperatively. In addition, adverse effects will be recorded.

ETHICS AND DISSEMINATION

The study is approved by the Central Denmark Region Committee on Biomedical research ethics. The results of this study will be presented at national and international congresses and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03158454; Pre-results.

Similar views on rehabilitation following hip arthroscopy among physiotherapists and surgeons in Scandinavia: a specialized care survey

PURPOSE

The rising number of hip arthroscopies (HA) is leading to increasing numbers of patients requiring post-surgical rehabilitation; however, evidence regarding post-operative rehabilitation is currently limited. The purpose of the study was to describe and compare current rehabilitation strategies and views among surgeons and physiotherapists in Scandinavia.

METHODS

Scandinavian surgeons and physiotherapists experienced with HA and post-surgical rehabilitation were asked to complete an online survey. Ninety clinicians (28 surgeons, 62 physiotherapists) responded.

RESULTS

Both professions mostly rated physiotherapy as very or extremely important in the rehabilitation process. The majority advocated criteria-based or combined criteria- and time-based progression. Expected rehabilitation timelines were reported with large intra-professional variation but general inter-professional agreement. However, compared with physiotherapists surgeons expected fewer weeks on crutches and faster return to competitive sport. Surgeons more often reported use of evidence-based self-reported outcomes while physiotherapists more often evaluated readiness for return to play.

CONCLUSIONS

Among surgeons and physiotherapists, physiotherapy is considered very important following HA. Generally, very similar views were held between professions. Surgeons expected reduced time on crutches and to return to competitive sports than physiotherapists. Surgeons also used evidence-based self-reported outcomes to a higher degree than physiotherapists. Being the first study to provide an overview on currently applied rehabilitation strategies following HA, results of this study may guide much needed, future research on the rehabilitation process following HA.

LEVEL OF EVIDENCE

IV.

Dynamic radiostereometric analysis for evaluation of hip joint pathomechanics

BACKGROUND

Dynamic RSA (dRSA) enables non-invasive 3D motion-tracking of bones and may be used to evaluate in-vivo hip joint kinematics including hip pathomechanics such as femoroacetabular impingement (FAI) and the biomechanical effects of arthroscopic cheilectomy and -rim trimming (ACH). The study aim was to evaluate the kinematic changes in the hip joint after ACH.

METHODS

Seven non-FAI affected human cadaveric hips were CT-scanned and CT-bone models were created. dRSA recordings of the hip joints were acquired at five frames/s during passive flexion, adduction to stop, and internal rotation to stop (FADIR). ACH was performed and dRSA was repeated. dRSA images were analyzed using model-based RSA. Hip joint kinematics before and after ACH were compared pairwise. The volume of removed bone was quantified and compared to the postoperative range of motion (ROM).

RESULTS

Mean hip internal rotation increased from 19.1 to 21.9° (p = 0.04, Δ2.8°, SD 2.7) after ACH surgery. Mean adduction of 3.9° before and 2.7° after ACH surgery was unchanged (p = 0.48, Δ-1.2°; SD 4.3). Mean flexion angles during dRSA tests were 82.4° before and 80.8° after ACH surgery, which were similar (p = 0.18, Δ-1.6°, SD = 2.7). No correlation between volume of removed bone and ROM was observed.

CONCLUSIONS

A small increase in internal rotation, but not in adduction, was observed after arthroscopic cheilectomy and -rim trimming in cadaver hips. The hip flexion angle of the FADIR test was reproducible. dRSA kinematic analysis is a new and clinically applicable method with good potential to evaluate hip joint kinematics and to test FAI pathomechanics and other surgical corrections of the hip.