PREHAB FAI- Prehabilitation for patients undergoing arthroscopic hip surgery for Femoroacetabular Impingement Syndrome -Protocol for an assessor blinded randomised controlled feasibility study.

BACKGROUND: The past decade has seen an exponential growth of minimally invasive surgical procedures. Procedures such as hip arthroscopy have rapidly grown and become the standard of care for patients with Femoroacetabular Impingement Syndrome (FAIS). Although, the results of such procedures are encouraging, a large proportion of patients do not achieve optimal outcomes due to chronicity and deconditioning as a result of delay in diagnosis and increased waiting times amongst other factors. In a recent systematic review and meta-analysis of randomised control trials, moderate certainty evidence supported prehabilitation over standard care in optimising several domains including muscle strength, pain and health related quality of life in patients undergoing orthopaedic surgical interventions. However, the role of prehabilitation in patients with FAI syndrome undergoing hip arthroscopy has received little attention. AIM: To evaluate the feasibility, suitability, acceptability and safety of a prehabilitation programme for FAI to inform a future definitive randomised control trial to assess effectiveness. METHODS: A systematically developed prehabilitation intervention based on a literature review and international consensus will be utilised in this study. A mixed methodology encompassing a two-arm randomised parallel study alongside an embedded qualitative component will be used to answer the study objectives. Patients will be recruited from a tertiary referral NHS centre for young adult hip pathology in the UK. Patient reported outcomes such as iHOT-12, Brief Pain Inventory Scale (Short form), Hospital Anxiety and Depression Scale and Patient Global Impression of Change score will be obtained alongside objective measurements such as Muscle Strength and Star Excursion Balance Test at various time points. Outcome measures will be obtained at baseline (prior to prehabilitation intervention), after prehabilitation before surgery, and at 6 weeks+/- 4 weeks and 6 months +/- 4 weeks (planned primary endpoint for definitive RCT) postoperatively when participants attend the research site for clinical care and remotely at 12 months +/- 4 weeks postoperatively. Mean change and 95% CI, and effect size of outcome measures will be used to determine the sample size for a future RCT. For the qualitative component, in depth face-to-face semi-structured interviews with physiotherapists and focus groups with participants will be conducted to assess the feasibility, suitability, and acceptability of the prehabilitation intervention using a predetermined success criteria. All qualitative data will be recorded, transcribed verbatim and thematically analysed. DISCUSSION: This study will be first of its kind to evaluate a systematically developed prehabilitation intervention for patients with FAIS undergoing hip arthroscopy. This study will provide important preliminary data to inform feasibility of a definitive RCT in the future to evaluate effectiveness of a prehabilitation intervention. TRIAL REGISTRATION: ISRCTN 15371248, 09/03/2023. TRIAL PROTOCOL: Version 2.3, 26th June 2023.

Computer-Assisted Arthroscopic Cam Resection.

Determining the appropriate femoral cam resection during hip arthroscopy for femoroacetabular impingement syndrome is both critical for the patient and challenging for the surgeon. Incomplete bone resection is a leading cause of failed hip arthroscopy, whereas over-resection may increase the risk of femoral neck fracture. The alpha angle is a validated 2-dimensional radiographic measurement used to both diagnose femoroacetabular impingement syndrome preoperatively and to determine resection adequacy postoperatively. Computer-assisted intraoperative guidance systems enhance the accuracy of femoral cam resection, although a preoperative 3-dimensional computed tomography scan may be required. Other systems, such as the HipCheck software (Stryker, Kalamazoo, MI), have been developed to provide intraoperative guidance with live feedback using simultaneous alpha angle measurements overlayed on fluoroscopic images without the requirement for routine preoperative computed tomography. Via intraoperative touchscreen navigation, the surgeon identifies the midpoint of the femoral neck and femoral head. A commercial software program provides real-time alpha angle measurements, as well as enhanced visualization of the femoral cam deformity with an adjustable resection curve. Before the surgeon performs the cam resection, the software provides a template for appropriate resection depth in 6 positions of the hip. Upon completion of the femoral cam resection, the hip is again assessed in the same 6 positions and the alpha angle is assessed to ensure a complete resection.

Modern Hip Arthroscopy for FAIS May Delay the Natural History of Osteoarthritis in 25% of Patients: A 12-Year Follow-up Analysis.

BACKGROUND: Little is known about the effect of modern hip arthroscopy on the natural history of femoroacetabular impingement syndrome (FAIS) with respect to joint preservation. PURPOSE: To (1) characterize the natural history of FAIS and (2) understand the effect of modern hip arthroscopy by radiographically comparing the hips of patients who underwent only unilateral primary hip arthroscopy with a minimum follow-up of 10 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between 2010 and 2012, 619 consecutive patients were reviewed from the practice of a single fellowship-trained hip arthroscopic surgeon. Inclusion criteria were FAIS, bilateral radiographic findings of femoroacetabular impingement, primary unilateral hip arthroscopy (labral repair, femoroplasty, or capsular closure), and minimum 10-year follow-up. The preoperative and minimum 10-year postoperative radiographs of patients were evaluated at each time point. Both operative and nonoperative hips were graded using the Tönnis classification or the presence of hip arthroplasty by 2 independent reviewers. Subgroup analyses were performed. RESULTS: A total of 200 hips from 100 patients were evaluated at a mean follow-up of 12.0 years. Preoperatively, 98% and 99% of operative and nonoperative hips were evaluated as Tönnis grades 0 and 1, respectively; 5% of nonoperative hips had worse Tönnis grades than operative hips. The nonoperative hip advanced to a worse Tönnis grade in 48% (48/100) of cases compared with 28% (28/100) among operative hips. At follow-up, Tönnis grades between hips were equal in 70% (70/100) of the cases, the operative hip had a better grade 25% (25/100) of the time, and the nonoperative hip had a better grade 5% (5/100) of the time. Modern hip arthroscopy was associated with a relative risk reduction of 42% in osteoarthritis progression. Impingement with borderline dysplasia, age, preoperative Tönnis grade, and alpha angle >65° were key risk factors in the radiographic progression of osteoarthritis. CONCLUSION: Although the majority of patients (70%) undergoing hip arthroscopy for FAIS did not experience differences between operative and nonoperative hips in terms of the radiographic progression of osteoarthritis, the natural history may be favorably altered for 25% of patients whose Tönnis grade was better after undergoing arthroscopic correction. Modern hip arthroscopy indications and techniques represent a valid joint-preservation procedure conferring a relative risk reduction of 42% in the progression of osteoarthritis. Arthroscopy for mixed patterns of impingement and instability were the fastest to degenerate.

Long-term Outcomes of Primary Hip Arthroscopy: Multicenter Analysis at Minimum 10-Year Follow-up With Attention to Labral and Capsular Management.

BACKGROUND: Hip arthroscopy is rapidly advancing, with positive published outcomes at short- and midterm follow-up; however, available long-term data remain limited. PURPOSE: To evaluate outcomes of primary hip arthroscopy at a minimum 10-year follow-up at 2 academic centers by describing patient-reported outcomes and determining reoperation and total hip arthroplasty (THA) rates. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with primary hip arthroscopy performed between January 1988 and April 2013 at 2 academic centers were evaluated for postoperative patient-reported outcomes-including the visual analog scale, Tegner Activity Scale score, Hip Outcome Score Activities of Daily Living and Sport Specific subscales, modified Harris Hip Score, Nonarthritic Hip Score, 12-item International Hip Outcome Tool, surgery satisfaction, and reoperations. RESULTS: A total of 294 patients undergoing primary hip arthroscopy (age, 40 ± 14 years; 66% women; body mass index, 27 ± 6) were followed for 12 ± 3 years (range, 10-24 years) postoperatively. Labral debridement and repair were performed in 41% and 59% of patients, respectively. Of all patients who underwent interportal capsulotomy, 2% were extended to a T-capsulotomy, and 11% underwent capsular repair. At final follow-up, patients reported a mean visual analog scale at rest of 2 ± 2 and with use of 3 ± 3, a 12-item International Hip Outcome Tool of 68 ± 27, a Nonarthritic Hip Score of 81 ± 18, a modified Harris Hip Score of 79 ± 17, and a Hip Outcome Score Activities of Daily Living of 82 ± 19 and Sport Specific subscale of 74 ± 25. The mean surgical satisfaction was 8.4 ± 2.4 on a 10-point scale, with 10 representing the highest level of satisfaction. In total, 96 hips (33%) underwent reoperation-including 65 hips (22%) converting to THA. THA risk factors included older age, higher body mass index, lower lateral center-edge angle, larger alpha angle, higher preoperative Tönnis grade, as well as labral debridement and capsular nonrepair (P≤ .039). Patients undergoing combined labral and capsular repair demonstrated a THA conversion rate of 3% compared with 31% for patients undergoing combined labral debridement and capsular nonrepair (P = .006). Labral repair trended toward increased 10-year THA-free survival (84% vs 77%; P = .085), while capsular repair demonstrated significantly increased 10-year THA-free survival (97% vs 79%; P = .033). CONCLUSION: At a minimum 10-year follow-up, patients undergoing primary hip arthroscopy demonstrated high satisfaction and acceptable outcome scores. In total, 33% of patients underwent reoperation-including 22% who underwent THA. Conversion to THA was associated with patient factors including older age, higher Tönnis grade, and potentially modifiable surgical factors such as labral debridement and capsular nonrepair.

Association Between Chondrolabral Junction Breakdown and Conversion to Total Hip Arthroplasty After Hip Arthroscopy for Symptomatic Labral Tears: Minimum 8-Year Follow-up.

BACKGROUND: Arthroscopic treatment of femoroacetabular impingement (FAI) and symptomatic labral tears confers short- to midterm benefits, yet further long-term evidence is needed. Moreover, despite the physiological and biomechanical significance of the chondrolabral junction (CLJ), the clinical implications of damage to this transition zone remain understudied. PURPOSE: To (1) report minimum 8-year survivorship and patient-reported outcome measures after hip arthroscopy for FAI and (2) characterize associations between outcomes and patient characteristics (age, body mass index, sex), pathological parameters (Tönnis angle, alpha angle, type of FAI, CLJ breakdown), and procedures performed (labral management, FAI treatment, microfracture). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This retrospective cohort study included patients who underwent primary hip arthroscopy for symptomatic labral tears secondary to FAI by a single surgeon between 2002 and 2013. All patients were ≥18 years of age with minimum 8-year follow-up and available preoperative radiographs. The primary outcome was conversion to total hip arthroplasty (THA), and secondary outcomes included revision arthroscopy, patient-reported outcome measures, and patient satisfaction. CLJ breakdown was assessed using the Beck classification. Kaplan-Meier estimates and weighted Cox regression were used to estimate 10-year survivorship (no conversion to THA) and identify risk factors associated with THA conversion. RESULTS: In this study of 174 hips (50.6% female; mean age, 37.8 ± 11.2 years) with mean follow-up of 11.1 ± 2.5 years, the 10-year survivorship rate was 81.6% (95% CI, 75.9%-87.7%). Conversion to THA occurred at a mean 4.7 ± 3.8 years postoperatively. Unadjusted analyses revealed several variables significantly associated with THA conversion, including older age; higher body mass index; higher Tönnis grade; labral debridement; and advanced breakdown of the CLJ, labrum, or articular cartilage. Survivorship at 10 years was inferior in patients exhibiting severe (43.6%; 95% CI, 31.9%-59.7%) versus mild (97.9%; 95% CI, 95.1%-100%) breakdown of the CLJ (P < .001). Multivariable analysis identified worsening CLJ breakdown (weighted hazard ratio per 1-unit increase, 6.41; 95% CI, 3.11-13.24), older age (1.09; 95% CI, 1.04-1.14), and higher Tönnis grade (4.59; 95% CI, 2.13-9.90) as independent negative prognosticators (P < .001 for all). CONCLUSION: Although most patients achieved favorable minimum 8-year outcomes, several pre- and intraoperative factors were associated with THA conversion; of these, worse CLJ breakdown, higher Tönnis grade, and older age were the strongest predictors.

[Risk factors for hip osteoarthritis after arthroscopy in patients with femoroacetabular impingement].

OBJECTIVE: To investigate the risk factors of hip osteoarthritis（HOA） after hip arthroscopy in patients with femoro-acetabular impingement（FAI） syndrome, and to reduce and prevent HOA. METHODS: From September 2018 to September 2020, 106 patients with FAI underwent hip arthroscopy, including 40 males and 66 females, aged from 20 to 55 years old with an average age of （33.05±10.19） years old. The mechanism of injury included 51 cases for sports injury, 36 for traffic accidents, and 19 for blunt object injury. The duration of the disease ranged from 5 to 19 days with an average of （12.02±3.69） days. All patients were followed up for 18 months. Patients were divided into HOA group （23 cases） and non-HOA group （83 cases） according to the occurrence of HOA. Multivariate Logistic regression was used to analyze the risk factors of HOA after hip arthroscopy in FAI patients. RESULTS: By univariate analysis, aged from 50 to 70 years old, female, body mass index（BMI）> 30 kg·m-2, physical labor, cam type, postoperative infection, last follow-up hip degree of motion （range of motion, ROM） （flexion, abduction, adduction, internal rotation） and Tönnis grade 1 and above of the HOA group were higher than those of the non-HOA group （P<0.05）, and the relative appendicular skeletal muscle index （RASM） was lower than that of non-HOA group（P<0.05）. By multiple Logistic regression analysis, cam type, BMI>30 kg·m-2, last follow-up hip internal rotation ROM and Tönnis grade 1 were risk factors for HOA after hip arthroscopy in FAI patients （P<0.05）. CONCLUSION: FAI classification, body mass index, hip ROM and Tönnis grade are all related to HOA after hip arthroscopy in FAI patients. Follow-up and intervention should be strengthened in high-risk FAI patients to reduce the occurrence of HOA.

The Effect of Pelvic Incidence on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement and Acetabular Labral Tears.

BACKGROUND: In the setting of femoroacetabular impingement (FAI), decompression osteoplasties reconcile deleterious loading patterns caused by cam and pincer lesions. However, native variations of spinopelvic sagittal alignment may continue to perpetuate detrimental effects on the labrum, chondrolabral junction, and articular cartilage after hip arthroscopy. PURPOSE: To evaluate the effect of pelvic incidence (PI) on postoperative outcomes after hip arthroscopy for acetabular labral tears in the setting of FAI. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective query of prospectively collected data identified patients ≥18 years of age who underwent primary hip arthroscopy for FAI and acetabular labral tears between February 2014 and January 2022, with 3-, 6-, 12-, and 24-month follow-ups. Measurements for PI, pelvic tilt (PT), sacral slope (SS), and acetabular version were obtained via advanced diagnostic imaging. Patients were stratified into low-PI (<45°), moderate-PI (45°≤ PI ≤ 60°), and high-PI (>60°) cohorts. Patient-reported outcome measures (PROMs), clinically meaningful outcomes (ie, minimal clinically important difference, Patient Acceptable Symptom State, substantial clinical benefit, and maximal outcome improvement), visual analog scale (VAS) pain scores, and patient satisfaction were compared across cohorts. RESULTS: A total of 74 patients met eligibility criteria and were stratified into low-PI (n = 28), moderate-PI (n = 31), and high-PI (n = 15) cohorts. Correspondingly, patients with high PI displayed significantly greater values for PT (P = .001), SS (P < .001), acetabular version (P < .001), and acetabular inclination (P = .049). By the 12- and 24-month follow-ups, the high-PI cohort was found to have significantly inferior PROMs, VAS pain scores, rates of clinically meaningful outcome achievement, and satisfaction relative to patients with moderate and/or low PI. No significant differences were found between cohorts regarding rates of revision arthroscopy, subsequent spine surgery, or conversion to total hip arthroplasty. CONCLUSION: After hip arthroscopy, patients with a high PI (>60°) exhibited inferior PROMs, rates of achieving clinically meaningful thresholds, and satisfaction at 12 and 24 months relative to patients with low or moderate PI. Conversely, the outcomes of patients with low PI (<45°) were found to match the trajectory of those with a neutral spinopelvic alignment (45°≤ PI ≤ 60°). These findings highlight the importance of analyzing spinopelvic parameters preoperatively to prognosticate outcomes before hip arthroscopy for acetabular labral tears and FAI.

The Promising 2-Year Performance of the Patient-Reported Outcomes Measurement Information System in Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

BACKGROUND: Minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds have been previously defined for the Patient-Reported Outcomes Measurement Information System (PROMIS) at 1-year follow-up in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome; however, the MCID and PASS thresholds are yet to be defined for the PROMIS at 2-year follow-up. PURPOSE: (1) To establish MCID and PASS thresholds for the PROMIS Pain Interference (PROMIS-PI) and PROMIS Physical Function (PROMIS-PF) at 2-year follow-up and (2) to correlate PROMIS scores with hip-specific patient-reported outcome measure (PROM) scores. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Patients undergoing primary hip arthroscopy for femoroacetabular impingement syndrome between August and November 2020 with preoperative and minimum 2-year postoperative data were identified. Collected scores included those for the PROMIS-PI, PROMIS-PF, Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), International Hip Outcome Tool-12 (iHOT-12), and visual analog scale (VAS) for pain. MCID thresholds were calculated using the distribution-based method and PASS thresholds using the anchor-based method. Pearson correlation coefficients were used to compare scores between PROMs. RESULTS: A total of 65 patients met the criteria for inclusion (72.3% female; mean age, 36.9 ± 13.5 years; mean body mass index, 26.2 ± 6.0). The mean follow-up was 25.3 ± 3.3 months. Significant preoperative to postoperative improvements were observed for all PROMs (P < .001). MCID thresholds and achievement rates were as follows: HOS-ADL, 10.1 and 75%, respectively; HOS-SS, 13.8 and 79%, respectively; iHOT-12, 14.0 and 67%, respectively; VAS pain, -13.8 and 78%, respectively; PROMIS-PI, -4.7 and 65%, respectively; and PROMIS-PF, 5.8 and 60%, respectively. PASS thresholds and achievement rates were as follows: HOS-ADL, 78.7 and 67%, respectively; HOS-SS, 76.4 and 62%, respectively; iHOT-12, 67.4 and 60%, respectively; VAS pain, 25.5 and 61%, respectively; PROMIS-PI, 57.0 and 65%, respectively; and PROMIS-PF, 45.6 and 58%, respectively. PROMIS-PI scores correlated most strongly with HOS-ADL (r = -0.836), HOS-SS (r = -0.767), and iHOT-12 (r = -0.719) scores and exhibited at least moderate correlations (r≥-0.595) with the other PROM scores. PROMIS-PF demonstrated moderate correlations with all the other PROM scores (r≥-0.586). Strong correlations were seen between the hip-specific PROM scores (r≥-0.745). CONCLUSION: This study defined 2-year MCID and PASS thresholds for the PROMIS-PI and PROMIS-PF and demonstrated moderate to strong correlations between PROMIS scores and hip-specific PROM scores.

Prevalence of hip femoroacetabular impingement deformities in high-level (La Liga) male professional football players.

BACKGROUND: Femoroacetabular impingement (FAI) is considered one of the main causes of hip osteoarthritis in young adults, especially in athletes. In recent years, morphological changes in FAI in the hip have been linked to early and intense sports participation, but studying top-level athlete samples is not easy. This paper presents the prevalence of FAI radiological markers in 120 active white male professional football players in the Spanish First Division League (La Liga) and compares the morphological changes with those of a control group of healthy individuals without significant sport activity. METHODS: The precontract medical evaluation hip X-rays of 120 white male professional football players from four different First Division Spanish football teams were prospectively filed and retrospectively reviewed by a dedicated skeletal radiologist. The footballers' hip X-rays were compared with those of a control group of 80 healthy individuals (age-sex matched) without significant sport activity (obtained from routine work medical checks). RESULTS: The femoral head-neck deformity associated with the Cam type of femoroacetabular impingement was observed in 61.6% of professional football players and only in 11.6% of the control group (p <0.01). The presence of "herniation pit" (11.6%) and os acetabuli (13.3%) also reached statistical significance in the professional football players group. In the other analyzed parameters, no statistically significant differences between the groups were observed. CONCLUSIONS: White professional top-level football players have an increased incidence of abnormal lateral epiphyseal extension ("pistol grip deformity"), os acetabuli and herniation pits.

Pre-operative gait kinematics and kinetics do not change following surgery in adolescent patients with femoroacetabular impingement.

BACKGROUND: Femoroacetabular impingement (FAI) is a condition where the femoral head-neck junction collides with the acetabulum. Open or arthroscopic treatment of FAI aims to increase hip motion while reducing impingement during passive or dynamic movements. RESEARCH QUESTION: What are the biomechanical characteristics of the hip and pelvis in adolescents and young adults diagnosed with FAI syndrome 1) pre-operatively compared to controls and 2) pre- to post-operatively? METHODS: 43 patients with FAI and 43 controls were included in the study. All patients with FAI had cam deformities and underwent unilateral hip preservation surgery (either open or arthroscopic). Pre- and post-operative imaging, patient-reported outcomes, and gait analysis were performed. Joint angles and internal joint moments were evaluated with an emphasis on the pelvis and hip. A comparative analysis was conducted to evaluate the gait patterns before and after surgical treatment, as well as to compare pre-operative gait patterns to a control group. RESULTS: 43 patients with FAI (28 female, 16.5 ± 1.5 yrs) and 43 controls (28 female, 16.0 ± 1.5 yrs) were included. Pre-operative patients with FAI had decreased stride length and walking speed compared to controls, with no significant change following surgery. There were no differences in sagittal and coronal plane hip and pelvis kinematics comparing pre- to post-operative and pre-operative to controls. Pre-operatively, differences in internal hip rotation angle (pre: 3.3˚, post: 3.9˚, controls: 7.7˚) and hip extensor moment (pre: 0.121, post: 0.090, controls: 0.334 Nm/kg) were observed compared to controls with no significant changes observed following surgery. SIGNIFICANCE: Compensatory movement strategies in pelvic and hip motion are evident during gait in patients with FAI, particularly in the sagittal and transverse planes. These strategies remained consistent two years post-surgery. While surgery improved radiographic measures and patient-reported outcomes, gait did not elicit biomechanical changes following surgical treatment.

Editorial Commentary: Female Patients With Lower Body Mass Index Show the Best Outcomes After Hip Arthroscopy, and Arthroscopic Treatment of Femoroacetabular Impingement in Higher-Body Mass Index Female Patients Results in Improved Outcomes.

Which patients will benefit most from hip arthroscopy? Careful patient selection and conservative indications, such as patients with an alpha angle of 60° or greater or a lateral center-edge angle of 40° or greater who fail a trial of conservative treatment, may benefit from hip arthroscopy for femoroacetabular impingement (FAI). In female patients in particular, a lower body mass index (BMI) will predict the most benefit from arthroscopic treatment. That said, patients with a higher BMI can also substantially improve after treatment of FAI. The true art of medicine is determining indications for an individual patient in addition to providing evidence-based counseling and education. We must not forget that sometimes "any improvement" can be a good outcome for a patient who is in pain.

Editorial Commentary: Arthroscopy With Labral Preservation or Reconstruction Plus Capsular Closure Shows Excellent Outcome in Patients With Borderline Hip Dysplasia and is Less Invasive Than Periacetabular Osteotomy.

Borderline developmental dysplasia of the hip (BDDH), or borderline hip dysplasia (BHD), traditionally characterized by a relatively low lateral center-edge angle (LCEA), presents a complex challenge in treatment due to its multifaceted etiology involving instability, femoroacetabular impingement (FAI), or a combination thereof. The optimal approach to managing adult BDDH remains a subject of significant debate. Periacetabular osteotomy (PAO) is considered the preferred treatment for addressing severe acetabular under-coverage, as it rectifies the underlying bony deficiency and promotes stability. However, the treatment of BDDH is less straightforward, particularly with the advancement of hip arthroscopy techniques, specifically labral preservation and capsular management. Given the minimally invasive and rapid postoperative rehabilitation advantage for arthroscopic procedures over open surgeries, numerous attempts have been undertaken in this context. Research has revealed favorable patient-reported outcomes (PROs), low failure rates, and a significant proportion of returning to sports (RTS) after arthroscopic management for patients with BDDH. Although we might in the right direction, Level I evidence studies are needed to comprehensively compare long-term PROs, failure rates, and rates of RTS between arthroscopy and PAO in the treatment of BDDH.

Editorial Commentary: Physical Therapy Alone May Not Successfully Treat Patients With Hip Pain and Large α Angles or Decreased Femoral Anteversion Combined With Femoroacetabular Impingement Syndrome.

Understanding the relation between spinopelvic (lumbopelvic) tilt and femoracetabular impingement syndrome (FAIS) is complex, and determining the optimal patient parameters that lead to successful nonoperative management is vital. Physical therapy (PT) focusing on core and posterior chain strengthening is often successful. PT can change the posterior tilt of the pelvis by 5° to 10°, allowing increased range of motion (ROM) and decreased impingement of the hip. However, PT does not change cam anatomy. Thus, PT alone may not sufficiently increase ROM in patients with cam-type impingement and large α angles or limited femoral anteversion. Pelvic compensation may lead to successful nonoperative management of FAIS, but not in all patients. Large-cam, high-flexion athletes with chronic hip pain should try PT. Yet, while some patients with large cam lesions may improve without surgery if femoral version and/or pelvic tilt ROM can be increased, surgery should not be excessively delayed in patients with poor prognostic factors for nonoperative management.

Editorial Commentary: Younger Patients With Hip Femoroacetabular Impingement Syndrome and a Superolateral Cam Lesion Location May Require Aggressive Treatment to Prevent Post-Arthroscopy Total Hip Replacement.

Hip femoroacetabular impingement syndrome is observed in 47% to 74% of patients with hip pain. Femoroacetabular impingement syndrome may result in osteoarthritis. It is well known that cam lesion volume and hip alpha angle are critical parameters determining patient outcomes. Recent research shows that a superolateral cam lesion location increases risk of hip arthroplasty at 5 years, and that this is more common in younger patients. The clinical relevance is that we may need to more aggressively treat superolateral cam lesions in younger patients, pending additional research to determine whether location is destiny.

Editorial Commentary: Small Labral Size on Magnetic Resonance Imaging Is an Indication for Labral Reconstruction in the Setting of Revision Hip Arthroscopy.

Revision hip arthroscopy is an increasingly common procedure as rates of primary hip arthroscopy rise. Etiologies for symptom recurrence may include residual femoroacetabular impingement, cam over-resection, labral pathology, chondral wear, adhesions, and instability. This has spawned sophisticated surgical techniques in hip arthroscopy including labral reconstruction. Indications for labral reconstruction in the revision setting obviously include labral deficiency. In addition, in the absence of other obvious reasons for failure of the primary procedure, a labral reconstruction should be considered for diminutive labra. The ability to predict labral size before surgery based on magnetic resonance imaging can be invaluable.

Editorial Commentary: Capsule Repair Is Necessary at the Conclusion of Arthroscopy to Optimize Return to Full Activity.

Hip capsulotomy and capsule repair have minimal effect on joint kinematics during activities of daily living. With low demands placed on the hip, the hip capsule may provide little to no role on hip stability or microinstability. But the majority, if not all, patients undergoing hip arthroscopy are not content with only resuming basic activities of daily living. Seeking to optimize the hip joint to its maximum capacity should be the goal. Capsule repair is necessary in most to achieve that goal.

Increased Duration and Intensity of Physical Activity Are Associated With Increased Pain in Individuals With Femoroacetabular Impingement Syndrome: An Ecological Momentary Assessment Study.

OBJECTIVE: To investigate the relation between accelerometer-measured physical activity and real-time pain in individuals with femoroacetabular impingement syndrome (FAIS). We tested the hypothesis that increased duration of high intensity activity would contribute to momentary increases in pain. DESIGN: Observational study. SETTING: Participants' natural, day-to-day environment. PARTICIPANTS: Population-based sample of 33 individuals with unilateral FAIS. Important eligibility criteria included no concomitant hip disorders or previous hip surgery. Key sociodemographic features include that all participants were required to have a smartphone. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Duration and intensity of physical activity as measured by a waist-worn accelerometer, and instantaneous pain reported in real-time smartphone-based ecological momentary assessment surveys. Physical activity variables included each person's average sedentary time, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) in the 90 minutes proceeding all pain surveys as well as fluctuation in sedentary, LPA, and MVPA above or below average prior to each individual survey. RESULTS: Linear mixed models revealed that the significant predictors of pain included fluctuation in sedentary time (B=-0.031, P<.001), average LPA (B=0.26, P=.035), and the interaction between fluctuation in LPA and fluctuation in MVPA (B=0.001, P<.001). Fluctuation in sedentary time above a person's average was associated with lower pain, while average LPA and fluctuations above average in both LPA and MVPA were associated with higher pain. CONCLUSIONS: These results suggest that individuals with FAIS can engage in health-enhancing MVPA but should focus on avoiding concurrent increase above average in both high intensity and LPA in the same 90-minute period. Future work is warranted testing the efficacy of such an approach on pain. Additionally, given that high levels of LPA may arise from a host of socioeconomic factors, additional research is needed to disentangle the effect of LPA on pain in FAIS.

Dynamic joint stiffness in individuals with femoroacetabular impingement syndrome pre- and post-hip arthroscopy.

BACKGROUND: Patients with hip-related pain often fail to return to their desired level of activity following hip arthroscopy. Lasting biomechanics alterations may be one potential explanation. Dynamic joint stiffness assesses the mechanistic controls of the lower limb during high impact movements, and thus, may provide valuable clinical targets to improving movement and optimizing return to activity after surgery. METHODS: Twenty-five participants (13 females) with hip-related pain underwent 3D motion capture during a drop jump task before surgery and six months post-operatively. Nineteen healthy controls (9 females) were collected for comparison. Sagittal plane dynamic joint stiffness was calculated during the initial landing phase. Baseline and 6-month dynamic joint stiffness data were compared 1) between males and females with hip-related pain and 2) between individuals with hip-related pain and controls using Wilcoxon Signed-Rank and Mann Whitney U tests. Sexes were analyzed separately. FINDINGS: From baseline to 6 months post-operatively, females with hip-related pain demonstrated decreased dynamic ankle stiffness (2.26 Nm/deg. [0.61] to 1.84 Nm/deg. [0.43]) (p = .005) and males with hip-related pain demonstrated increased dynamic hip stiffness (2.73 [0.90] to 3.88 [1.73]) (p = .013). There were no differences in dynamic stiffness at any joint between individuals with hip-related pain at either timepoint when compared to controls (p ≥ .099). INTERPRETATION: Females and males with hip-related pain may demonstrate unique changes in dynamic joint stiffness after surgery, indicating return to activity may follow different trajectories for each sex. Additional work should examine the relationship between hip joint stiffness and treatment outcomes and identify additional movement-related rehabilitation targets.

Current concepts in the diagnosis and management of Os Acetabuli.

PURPOSE: The aim of this review is to appraise the current evidence on the epidemiology, pathophysiology, diagnosis and management of os acetabuli. METHODS: A scoping review was conducted according to the Joanna Briggs Institute guidelines. A systematic search was performed on Medline (PubMed), Embase and Cochrane Library. Inclusion criteria comprised observational and interventional studies and review articles published in the English language that focused on patients with os acetabuli according to the PRISMA extension of scoping reviews checklist using the terms 'Os Acetabuli' or 'os acetabula' or 'acetabular ossicles'. A narrative synthesis of results was undertaken, and the included articles were divided into (i) definition, (ii) aetiology, (iii) diagnosis and imaging and (iv) management of os acetabuli. RESULTS: 107 articles were screened, with 22 meeting the eligibility criteria. A total of 8836 patients were considered, of which 604 had os acetabuli. The mean age was 32.8 years. The prevalence of os acetabuli ranged from 3.4 to 7.7%, with a higher prevalence in males compared to females. True os acetabuli was defined as an unfused secondary ossification centre along the acetabular rim. The aetiology of os acetabuli is thought to be secondary to acetabular dysplasia and/or femoroacetabular impingement. Standard of care for management of symptomatic os acetabuli is considered to be arthroscopic excision unless the excision results in acetabular undercoverage and/or instability, in which case, fixation is recommended. CONCLUSIONS: Successful management of os acetabuli depends on understanding the pathology and treating the underlying cause rather than treating the os acetabuli in isolation. Future work needs to focus on establishing clear diagnostic criteria, consensus on definition and an evidence-based treatment algorithm.