Corrigendum to "No Significant Differences in Clinical Outcomes Were Observed Between Healed and Unhealed Hip Joint Capsules in Femoroacetabular Impingement Syndrome After Arthroscopy [Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 41, No 9 (September), 2025: pp 3540-3552.e2".

Introduction Patients with intra-articular hip pathology see an average of three clinicians prior to diagnosis. A 2015 study by Rankin et al. suggested femoroacetabular impingement (FAI) syndrome was described in 40% of hip joint pathology. FAI syndrome occurs when irregularities in femoral and acetabular anatomy create abnormal contact forces across the joint, leading to labral and chondral damage. These anatomical irregularities are categorised into three morphologies: cam (an aspherical femur head resulting in superior acetabulum impingement), pincer (over-coverage of the femoral head by the acetabulum) and mixed. This case highlights this tricky diagnosis in a young and active patient. Case description A 28-year-old fit and active man presented with a three-year history of gradually worsening atraumatic right hip pain. He described a constant ache in the anterior aspect of the right hip, occasionally referring to the groin and right knee. He experienced significant morning stiffness of the right hip, lasting approximately 30 minutes. His symptoms were aggravated by prolonged walking and running. He denied lower limb paraesthesia, numbness, incontinence, rashes and was otherwise systemically well. He reported no past medical history, family history and was on no regular medications. He practises yoga a few times a week but has had to stop his recreational running due to his pain. Examination revealed no deformity of the lumbar or sacral spine. There was no swelling, redness, or tenderness on palpation. Range of motion of the right hip was significantly limited, with flexion to 90 degrees, abduction to 30 degrees, external rotation to 25 degrees and internal rotation to 0 degrees (in flexion). Trendelenburg's test was negative. Functional assessment revealed poor pelvic control on right side during single-leg squat and lunge. The modified Thomas test showed tense hip flexors bilaterally, worse on right. FADIR test was strongly positive on the right but all other special tests for the hip, including Laslett’s cluster of sacroiliac provocation tests, were negative. After significant discussion regarding radiation exposure, he was referred for an X-ray pelvis and right hip. This revealed significant widening of both femoral heads and necks, with joint space narrowing with articular sclerosis. This was worse on the right side with femoral osteophyte formation. Appearances were in keeping with bilateral cam morphology, with associated changes in the right hip joint indicative of femoral acetabular impingement. He has since been referred to physiotherapy and orthopaedics to explore management options, whilst encouraged to continue his yoga practise. Discussion A 2014 cross-sectional study by Clohisy et al. reported the average age of FAI syndrome to be 28 years and the Frank et al. 2015 systematic review revealed cam morphology was more prevalent in men and three times more likely in athletes than the general population. This patient exemplifies these demographics. His history and examination contained features typical of FAI syndrome: his description of pain on movement, positive FADIR test, restricted internal rotation restriction, and poor single leg balance. However, classical symptoms of clicking, catching, and locking were not reported. This corroborates with the 2016 Warwick Consensus statement that FAI syndrome diagnosis does not rely on a single symptom or clinical sign. The statement confirms that X-Ray is the initial imaging modality of choice, which includes AP, lateral and Dunn views as was requested in this case. Treatment options to allow our patient to return to running include conservative management with patient education, anti-inflammatory agents, and physiotherapy. The Hoit et al. 2019 systematic review showed that physiotherapy, targeting core stability, proprioception, and correction of hip destabilising imbalances, provided significant improvements in functional outcomes compared to controls without. This supports a trial of physiotherapy before further interventions and commends the patient’s participation in yoga. Evidence for intra-articular injections of corticosteroids, hyaluronic acid or platelet-rich plasma is currently limited and are unlikely to be considered for this patient. Surgery aims to arthroscopically correct anatomical abnormalities. Two RCTs, UK FASHIoN and FAIT, compared surgery and physiotherapy interventions in FAI syndrome patients and showed statistically significant improvement in symptoms and functional outcomes with surgery, particularly in those with cam morphology like our patient. Orthopaedics may offer this option to our patient due to his lack of negative prognostic indicators related to surgery with the exception of his extended duration of symptoms. Key learning points Hip and pelvic pain with morning stiffness in a young adult male is not always inflammatory in nature, and femoroacetabular impingement (FAI) syndrome should be considered in these patients. FAI is associated with pain on movement, positive FADIR test, restricted internal rotation, and poor single leg balance, but clicking/locking is not always described. In primary care where access to MR imaging may be limited, AP, lateral and Dunn view X-rays of the pelvis and femoral neck can help clinch the diagnosis if there is uncertainty Cam morphology of the hip, revealed by X-ray, is more prevalent in men and athletes and has better treatment outcomes with surgery compared to physiotherapy. Referral to a specialist musculoskeletal service is recommended to discuss management options of physiotherapy, intra-articular injections and surgery alongside patient education and anti-inflammatory medication. Discussing the clinical experience of peers evaluating, diagnosing, treating, and monitoring long-term outcomes of similar patients will contribute to the understanding of the rapidly evolving evidence base.

This review explores the scientific evidence for clinical, functional and imaging outcomes after surgical management of Femoroacetabular Impingement (FAI) syndrome, and assesses the methodological quality of the published literature reporting this issue. The medical literature databases of Pubmed, Medline, Ovid, Google Scholar and Embase were searched for articles published in English, Spanish, French and Italian, using a combination of the keywords 'femoro-acetabular impingement syndrome', 'postoperative outcomes', 'open surgery', and 'arthroscopic management'. To address three main questions, we extracted data on demographic features, operative techniques, postoperative rehabilitation regimens, imaging features, pre and postoperative hip scores. Complications and conversion to arthroplasty were also investigated. Thirty-one studies published have reported clinical, functional and imaging outcomes after open and arthroscopic management of FAI syndrome. The modified Coleman methodology score (CMS) averaged 56.2 (range, 30-81). From extracted data, it was shown that arthroscopy, open surgery and arthroscopic surgery followed by mini open surgery are comparable for functional results, biomechanics, and return to sport. Progression of OA and conversion to hip arthroplasty are dependent on preoperative status of cartilage and osteoarthritis and type of management. Debridement and osteoplasty provide better results than debridement only. Significantly improved outcomes have been recorded in patients undergoing labral refixation than resection. The Coleman methodology score showed great heterogeneity in terms of study design and outcome assessment, and generally low methodological quality. Although open and minimally invasive procedures allow athletes to return to professional sports activity, they are contraindicated in patients with severe osteoarthritis and cartilage degeneration.

Current trends in sport and exercise hip conditions: Intra-articular and extra-articular hip pain, with detailed focus on femoroacetabular impingement (FAI) syndrome.

It is unknown if football players with femoroacetabular impingement (FAI) syndrome report worse burden than those with other causes of hip/groin pain, and to what extent this is mediated by cartilage defects and labral tears. Football players with FAI syndrome would report worse burden than other symptomatic players, with the effect partially mediated by cartilage defects and/or labral tears. Cross-sectional study. Level 4. Football (soccer and Australian football) players (n = 165; 35 women) with hip/groin pain (≥6 months and positive flexion-adduction-internal rotation test) were recruited. Participants completed 2 patient-reported outcome measures (PROMs; the International Hip Outcome Tool-33 [iHOT-33] and Copenhagen Hip and Groin Outcome Score [HAGOS]) and underwent hip radiographs and magnetic resonance imaging (MRI). FAI syndrome was determined to be present when cam and/or pincer morphology were present. Cartilage defects and labral tears were graded as present or absent using MRI. Linear regression models investigated relationships between FAI syndrome (dichotomous independent variable) and PROM scores (dependent variables). Mediation analyses investigated the effect of cartilage defects and labral tears on these relationships. FAI syndrome was not related to PROM scores (unadjusted b values ranged from -4.693 (P = 0.23) to 0.337 (P = 0.93)) and cartilage defects and/or labral tears did not mediate its effect (P = 0.22-0.97). Football players with FAI syndrome did not report worse burden than those with other causes of hip/groin pain. Cartilage defects and/or labral tears did not explain the effect of FAI syndrome on reported burden. FAI syndrome, cartilage defects, and labral tears were prevalent but unrelated to reported burden in symptomatic football players.

Patient factors predict severity of hip symptoms to a greater extent than abnormal bony hip morphology in femoroacetabular impingement syndrome

The relationship between kinesiophobia and self-reported outcomes and physical function differs between women and men with femoroacetabular impingement syndrome

The magnitude and location of hip contact force influence the local mechanical environment of the articular tissue, driving remodeling. We used a neuromusculoskeletal model to investigate hip contact force magnitudes and their regional loading patterns on the articular surfaces in those with femoroacetabular impingement (FAI) syndrome and controls during walking. An EMG-assisted neuromusculoskeletal model was used to estimate hip contact forces in eligible participants with FAI syndrome ( n = 41) and controls ( n = 24), walking at self-selected speed. Hip contact forces were used to determine the average and spread of regional loading for femoral and acetabular articular surfaces. Hip contact force magnitude and region of loading were compared between groups using statistical parametric mapping and independent t -tests, respectively ( P < 0.05). All of the following findings are reported compared with controls. Those with FAI syndrome walked with lower-magnitude hip contact forces (mean difference, -0.7 N·BW -1 ; P < 0.001) during first and second halves of stance, and with lower anteroposterior, vertical, and mediolateral contact force vector components. Participants with FAI syndrome also had less between-participant variation in average regional loading, which was located more anteriorly (3.8°, P = 0.035) and laterally (2.2°, P = 0.01) on the acetabulum but more posteriorly (-4.8°, P = 0.01) on the femoral head. Participants with FAI syndrome had a smaller spread of regional loading across both the acetabulum (-1.9 mm, P = 0.049) and femoral head (1 mm, P < 0.001) during stance. Compared with controls, participants with FAI syndrome walked with lower-magnitude hip contact forces that were constrained to smaller regions on the acetabulum and femoral head. Differences in regional loading patterns might contribute to the mechanobiological processes driving cartilage maladaptation in those with FAI syndrome.

The 2016 Warwick Agreement on femoroacetabular impingement (FAI) syndrome was convened to build an international, multidisciplinary consensus on the diagnosis and management of patients with FAI syndrome. 22 panel members...

The hip joint biomechanics of people with femoroacetabular impingement (FAI) syndrome are different from those of healthy people during a double-leg squat. However, information on biomechanics during a single-leg squat is limited. To compare hip joint biomechanics between people with FAI syndrome and people without hip pain during double-leg and single-leg squats. Fourteen people with FAI syndrome (cam, n = 7; pincer, n = 1; mixed, n = 6) and 14 people without hip pain participated in this cross-sectional, case-control, laboratory-based study. Three-dimensional biomechanics data were collected while all participants performed a double-leg and a single-leg squat. Two-way mixed-model analyses of variance were used to assess group-by-task interactions for hip joint angles, thigh and pelvis segment angles, hip joint internal moments, and squat performance variables. Post hoc analyses for all variables with a significant group-by-task interaction were performed to identify between-group differences for each task. There were significant group-by-task interactions for peak hip joint (P = .014, η2 = 0.211) and thigh segment (P = .009, η2 = 0.233) adduction angles, and for peak hip joint abduction (P = .002, η2 = 0.308) and extension (P = .016, η2 = 0.203) internal moments. There were no significant group-by-task interactions for squat performance variables. Biomechanical differences at the hip between people with FAI syndrome and those without hip pain were exaggerated during a single-leg squat compared to a double-leg squat task. Diagnosis, level 4. J Orthop Sports Phys Ther 2019;49(12):908-916. Epub 23 Jul 2019. doi:10.2519/jospt.2019.8356.

Surgical dislocation of the hip is rarely undertaken. The potential danger to the vascularity of the femoral head has been emphasised, but there is little information as to how this danger can be avoided. We describe a technique for operative dislocation of the hip, based on detailed anatomical studies of the blood supply. It combines aspects of approaches which have been reported previously and consists of an anterior dislocation through a posterior approach with a 'trochanteric flip' osteotomy. The external rotator muscles are not divided and the medial femoral circumflex artery is protected by the intact obturator externus. We report our experience using this approach in 213 hips over a period of seven years and include 19 patients who underwent simultaneous intertrochanteric osteotomy. The perfusion of the femoral head was verified intraoperatively and, to date, none has subsequently developed avascular necrosis. There is little morbidity associated with the technique and it allows the treatment of a variety of conditions, which may not respond well to other methods including arthroscopy. Surgical dislocation gives new insight into the pathogenesis of some hip disorders and the possibility of preserving the hip with techniques such as transplantation of cartilage.

Relationships between hip strength and hip biomechanics during running in people with femoroacetabular impingement syndrome

Do currently prescribed exercises reflect contributing pathomechanics associated with femoroacetabular impingement syndrome? A scoping review

Differences in isokinetic hip muscle torque between individuals with femoroacetabular impingement syndrome and pain-free controls: A cross-sectional study.

Background Femoroacetabular impingement (FAI) syndrome may affect gait kinematics differently between males and females. Objectives To investigate whether individuals with FAI syndrome have different hip and pelvic motion during gait, at their preferred speed and a prescribed speed, compared to individuals of the same sex without pain. Methods Twenty-one participants (11 males and 10 females) with FAI syndrome and 41 participants (19 males and 22 females) without hip pain were included in this case-control laboratory study. There were no differences between the 2 groups in age, body mass index, and activity score. Kinematic data for all participants were collected while walking at a preferred speed and at 1.25 m/s. For sex and walking speed, linear regression analyses were used to examine the effect of group and the interaction of group by limb. Results At both speeds, males with FAI syndrome walked with more than 6° less peak hip extension (P≤.018), 5° greater anterior pelvic tilt (P≤.020), and 5° less posterior pelvic tilt (P≤.018) compared to males without hip pain. Females with FAI syndrome walked with 2° less hip extension (P≤.012) and at least 3° more hip adduction (P<.001) in the more painful hip than in the less painful hip at both speeds. Conclusion Males and females with FAI syndrome have different gait alterations when compared to a same-sex comparison group. In males, differences were between groups. In females with FAI syndrome, differences were between the more painful and the less painful limb. J Orthop Sports Phys Ther 2018;48(8):649-658. Epub 22 May 2018. doi:10.2519/jospt.2018.7913.

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