Magnetic resonance imaging (MRI) is increasingly used in the classification and evaluation of osteoarthritis (OA). Many studies have focused on knee OA, investigating the association between MRI-detected knee structural abnormalities and knee pain. Hip OA differs from knee OA in many aspects, but little is known about the role of hip structural abnormalities in hip pain. This study aimed to systematically evaluate the association of hip abnormalities on MRI, such as cartilage defects, bone marrow lesions (BMLs), osteophytes, paralabral cysts, effusion-synovitis, and subchondral cysts, with hip pain. We searched electronic databases from inception to February 2024, to identify publications that reported data on the association between MRI features in the hip joint and hip pain. The quality of the included studies was scored using the Newcastle-Ottawa Scale (NOS). The levels of evidence were evaluated according to the Cochrane Back Review Group Method Guidelines and classified into five levels: strong, moderate, limited, conflicting, and no evidence. A total of nine studies were included, comprising five cohort studies, three cross-sectional studies, and one case-control study. Moderate level of evidence suggested a positive association of the presence and change of BMLs with the severity and progress of hip pain, and evidence for the associations between other MRI features and hip pain were limited or even conflicting. Only a few studies with small to modest sample sizes evaluated the association between hip structural changes on MRI and hip pain. BMLs may contribute to the severity and progression of hip pain. Further studies are warranted to uncover the role of hip MRI abnormalities in hip pain. The protocol for the systematic review was registered with PROSPERO ( https://www.crd.york.ac.uk/PROSPERO/ , CRD42023401233).

BACKGROUND: Individuals with acetabular dysplasia often report hip joint instability, pain, and poor hip-related function. Periacetabular osteotomy (PAO) is a surgical procedure that aims to reposition the acetabulum to improve joint congruency and improve pain and function. We aimed to examine the influence of presurgery clinical measures on functional recovery following PAO and the associations among clinical outcomes after PAO.
METHODS: We screened 49 potential participants, 28 were enrolled, and 23 completed both study visits (pre-PAO and 6 months post-PAO). We evaluated dynamometer-measured hip and thigh strength, loading patterns during a squat and countermovement jump (CMJ), pain intensity, and device-measured physical activity (PA) levels (light, moderate-to-vigorous PA [MVPA], and daily steps). We used linear regression models to examine the influence of muscle strength (peak torque; limb symmetry index [LSI]) and loading patterns before PAO on pain intensity and PA levels in individuals 6 months following PAO. Additionally, we used Pearson correlation coefficient to examine cross-sectional associations among all variables 6 months following PAO.
RESULTS: Lower extremity muscle strength and loading patterns during the squat and CMJ before PAO did not predict pain intensity or device-measured PA levels in individuals 6 months following PAO (p > 0.05). Six months following PAO, higher knee extensor LSI was associated with higher time spent in MVPA (r = 0.56; p = 0.016), higher hip abductor LSI was associated with both lower pain (r = 0.50; p = 0.036) and higher involved limb loading during the squat task (r = 0.59; p = 0.010). Lastly, higher hip flexor LSI was associated with higher CMJ takeoff involved limb loading (r = 0.52; p = 0.021) and higher involved hip extensor strength was associated with higher CMJ landing involved limb loading (r = 0.56; p = 0.012).
CONCLUSIONS: Six months after PAO, higher hip and thigh muscle strength and strength symmetry were associated with lower pain, higher PA levels, and greater normalized limb loading during dynamic movement tasks.

BACKGROUND: Iliacus muscle abscess is an uncommon but potentially life-threatening condition that can present with nonspecific symptoms, posing diagnostic challenges. This case report highlights the importance of considering iliopsoas abscess in patients presenting with fever and hip pain, especially in the absence of obvious risk factors or penetrating trauma. The novelty of this case lies in its atypical presentation mimicking a respiratory viral infection and musculoskeletal injury, impeding accurate diagnosis and appropriate management.
METHODS: A previously healthy 21-year-old female who had a mechanical fall 3 weeks prior presented with fever, right hip pain, and respiratory symptoms, initially suggestive of a respiratory infection and musculoskeletal injury. However, initial investigations revealing a markedly high C-reactive protein (CRP) concentration prompted further computed tomography (CT) imaging of her abdomen and pelvis, which uncovered an iliopsoas abscess presumably stemming from antecedent trauma. Subsequent CT guided aspiration along with culture-sensitive antibiotics led to successful treatment and resolution of her symptoms.
CONCLUSIONS: This case emphasizes the importance of considering iliopsoas abscess as a possible differential, even in young patients without typical risk factors. Markedly elevated inflammatory markers such as CRP concentrations can serve as a vital indicator, directing attention towards the possibility of septicemia or the presence of an occult abscess, facilitating prompt imaging and accurate diagnosis.

BACKGROUND: Obturator hernias are rare, occur mainly in slender people and predominantly in females. Underlying pathology of the obturator hernia is a weakening of the obturator membrane. The obturator hernia is situated between the pubic and ischial bones and is therefore clinically occult. Patients predominantly present with symptoms of bowel obstruction, but can also present with sensory disturbance, leg pain and hip pain. Due to the usually delayed diagnosis, the obturator hernia is associated with increased morbidity and mortality.
METHODS: A 71-year-old female patient with hip pain underwent a protracted diagnostic work-up and was referred to the surgical department by the treating orthopedic surgeon. An incarcerated obturator hernia with a fistula in the adductor ligament was finally diagnosed via CT. The operation included laparoscopic reduction, hernia repair, open small bowel segment resection, local surgical exploration, lavage and antibiotic treatment. The primary hernia repair was performed by direct suture due to the contamination, and a post-primary mesh repair was indicated. However, after complete recovery and no remaining symptoms, the patient refused this despite the indication for definitive laparoscopic hernia repair.
CONCLUSIONS: Hip pain can have multiple causes. Taking physical characteristics into account can lead to the correct diagnostic pathway. The CT scan revealed the fistula which led to the laparoscopic surgery. Due to the intestinal damage and contamination, the surgical steps were adapted.
CONCLUSIONS: Obturator hernias should be considered as a reason for atypical symptoms in slender, older patients. Adequate surgical management can be chosen after correct diagnosis.

BACKGROUND: The Movethehip trial investigates the effectiveness of an exercise and patient education intervention for adults with acetabular dysplasia. The intervention involves eight tailored one-to-one sessions with trained providers who employ supportive feedback tools. The present protocol reports a planned process evaluation, which aims to determine how the intervention functions by examining the implementation of the intervention (process, dose and reach), its acceptability, mechanisms of change and the influence of contextual factors.
METHODS: Two hundred trial participants aged 18-50 years will be recruited from a University Hospital in Denmark and randomised to the intervention or control group. Approximately ten providers will deliver the intervention. The process evaluation adopts a concurrent mixed-methods design. The implementation will be assessed using self-report questionnaires (at baseline and 6-month follow-up), training records and semi-structured focus group interviews with intervention providers (n = 10) and healthcare managers (n = 4-6). The mechanisms of change will be explored through semi-structured one-to-one interviews (at baseline and 6-month follow-up) with 15-20 purposefully sampled participants and by measuring changes in health outcomes (self-reported pain, physical functioning and quality of life completed at baseline and at 3- and 6-month follow-up). Additionally, change will be measured through an explorative examination of associations between dose and change in health outcomes, applying simple linear regression models. The acceptability of the intervention and the influence of contextual factors will be explored through one-to-one participant interviews and focus group interviews with 4-6 healthcare managers. The interviews will focus on expectations, experiences, events, personal understandings and interaction with interpersonal and organisational aspects. Interview data will be analysed using theoretical thematic analyses, and findings will be merged with quantitative data and reported jointly on a theme-by-theme basis.
CONCLUSIONS: The process evaluation conducted as part of the MovetheHip trial will illuminate how the intervention functions, and if the intervention is proven effective, the findings of the evaluation will contribute to pinpoint how the intervention may be optimised to facilitate future up-scaling and implementation.
BACKGROUND: The MovetheHip protocol was approved by the Committee on Health Research Ethics in the Central Denmark Region. ClinicalTrials, NCT04795843. Registered on 20 March 2021.

Calcific tendinitis of the rectus femoris is rare. This clinical report presents five cases of management of calcific tendinitis of the rectus femoris. Between July 2018 and March 2023, five patients visited our institution, where they were treated for calcific tendinitis of the rectus femoris. All patients presented with severe acute hip pain. Radiographs, computed tomography, magnetic resonance imaging, and an ultrasound examination of the hip showed calcification outside the joint, suggesting calcific tendinitis of the rectus femoris. All patients were orally administered 200 mg cimetidine and nonsteroidal anti-inflammatory drugs twice daily. A pain-free status was achieved in 2 weeks on average. Calcium deposits disappeared in three patients and decreased in two. Symptoms did not recur. Furthermore, no recurrence or enlargements in calcium deposits were observed. It appears to be an effective treatment for calcific tendinitis of the rectus femoris; however, the underlying mechanisms of action of cimetidine on calcific tendinitis have not yet been elucidated in detail.

OBJECTIVE: To evaluate the actual change in clinical hip pain and hip migration after operation for non-ambulatory flaccid neuromuscular (NM) scoliosis and investigate whether there is an association between hip migration and coronal/sagittal pelvic tilt (CO-PT/SA-PT).
METHODS: This retrospective, single-center, observational study evaluated a total of 134 patients with non-ambulatory flaccid neuromuscular scoliosis who underwent surgery performed by a single surgeon between 2003 and 2020, with at least 2 years of follow-up period. Operation procedures were conducted in two stages, beginning with L5-S1 anterior release followed by posterior fixation. Radiologic parameters were measured at preoperative, immediate postoperative, and last follow-up periods with clinical hip pain and clinical hip dislocation events.
RESULTS: The significant improvements occurred in various parameters after correction surgery for NM scoliosis, containing Cobb\'s angle of major curve and CO-PT. However, Reimer\'s hip migration percentage (RMP) was increased on both side of hip (High side, 0.23 ± 0.16 to 0.28 ± 0.21; Low side, 0.20 ± 0.14 to 0.23 ± 0.18). Hip pain and dislocation events were also increased (Visual analog scale score, 2.5 ± 2.3 to 3.6 ± 2.6, P value < 0.05; dislocation, 6-12). Logistic regression analysis of the interactions between ΔRMP(High) and the change of sagittal pelvic tilt (ΔSA-PT) after correction reveals a significant negative association. (95% CI 1.003-1.045, P value = 0.0226).
CONCLUSIONS: In cases of non-ambulatory flaccid NM scoliosis, clinical hip pain, and subluxation continued to deteriorate even after correction of CO-PT. There was a relationship between the decrease in SA-PT, and an increase in hip migration percentage on high side, indicating the aggravation of hip subluxation.

Myositis ossificans (MO) is a benign condition where bone forms within muscles due to increased activity of the periarticular tissues. Trauma is the most common cause. Nontraumatic MO is exceedingly rare. We present a rare instance of nontraumatic MO affecting the hip in a 32-year-old patient. The patient had a known case of seizure disorder and also had a history of a cerebrovascular accident (CVA). Despite the absence of trauma or known predisposing factors, the patient developed a sizable mass in the left hip, causing pain and restricted range of motion (ROM). Surgical excision of the mass was successful, resulting in complete removal and subsequent improvement in hip function and pain relief during postoperative recovery. Histopathological examination confirmed the diagnosis of MO. The patient\'s ROM normalized, and there were no signs of recurrence at the one-year follow-up. This case highlights the importance of recognizing MO in hip pain cases without trauma. Timely surgery through the approach described effectively removes the mass, preventing recurrence without compromising vital structures. It showcases a successful multidisciplinary approach for rare musculoskeletal conditions, offering valuable insights into similar cases.

OBJECTIVE: To (i) investigate the goals and expectations of participants enrolled in a clinical trial of physiotherapist-led treatment for femoroacetabular impingement (FAI) syndrome and (ii) explore associations between their expectations and self-reported hip burden and kinesiophobia. METHODS: Data from 150 participants with FAI syndrome who participated in a clinical trial were analysed. Participants described their most important treatment goal and the expectation of achieving this goal throughout physiotherapy treatment. The International Hip Outcome Tool (iHOT-33) subscales were used to assess self-reported hip burden. The Tampa Scale for Kinesiophobia was used to assess kinesiophobia. Participants goals were qualitatively analysed using content analysis. Linear regression was used to explore associations between patient expectations and iHOT and Tampa Scale for Kinesiophobia scores. RESULTS: Participants with FAI syndrome reported goals relating to exercise (52%), improving activities of daily living quality (23%), improving physical function (15%), and reducing pain (10%). Negative expectations regarding physiotherapist-led treatment were reported by 68% of participants. Those with negative expectations reported worse scores for the iHOT-Total score (mean difference = 12 points, 95%CI = [4 to 19]), and iHOT-Symptoms (14 points, [7 to 21]) and iHOT-Social (11 points, [2 to 21]) subscales compared to those with positive expectations. Treatment expectations were not associated with iHOT-Sport, iHOT-Job, and Tampa Scale for Kinesiophobia scores (p > 0.05). CONCLUSION: Patients with FAI syndrome had a generally negative expectation of physiotherapist-led treatment. There was a mismatch between patients\' goals and current treatment approaches. Participants with FAI syndrome and negative expectations reported worse quality of life, symptoms, and social concerns than those with positive expectations.

BACKGROUND: Physical therapist-led treatment programs are recommended for patients with femoroacetabular impingement (FAI) syndrome. Views of people with FAI syndrome regarding such interventions are currently unknown, including perceptions of potential barriers and facilitators to participation and adherence to exercise programs.
OBJECTIVE: To explore participant perceptions of physical therapist-led programs for FAI syndrome, including barriers and facilitators for accessing physical therapy, and adhering to a rehabilitation program.
METHODS: Our qualitative study used semi-structured interviews to explore the perceptions of patients with FAI syndrome undertaking physical therapy-led treatment, where treatment was ceased due to Coronavirus Disease 2019 (COVID-19). The interview topic guide was informed by the Theoretical Domain Framework. Interviews were transcribed verbatim and data categories were developed using inductive thematic analysis. Themes were discussed between researchers until consensus was reached.
RESULTS: Fourteen participants (mean age: 30 years) with a range of physical activity backgrounds undertook interviews. We identified four key themes, 1) Patients believed their hip pain was caused by structural damage worsened through exercise; 2) Barriers and facilitators on the feasibility of physical therapist-led programs; 3) Participants held beliefs regarding the importance of adjunct treatments to exercise; and 4) Impact of FAI syndrome on physical activity participation.
CONCLUSIONS: People with FAI syndrome believe they have structural damage which leads to their hip pain and are often afraid to exercise due to fear of causing more damage to their hip. Our findings suggest that people with FAI syndrome want clear education about exercise, imaging, and expectations of cost and duration of treatment.