BACKGROUND: Hip arthroscopy has seen a significant surge in utilization, but complications remain, and optimal functional outcomes are not guaranteed. Artificial intelligence (AI) has emerged as an effective supportive decision-making tool for surgeons. The purpose of this systematic review was to characterize the outcomes, performance, and validity (generalizability) of AI-based prediction models for hip arthroscopy in current literature.
METHODS: Two reviewers independently completed structured searches using PubMed/MEDLINE and Embase databases on August 10, 2022. The search query used the terms as follows: (artificial intelligence OR machine learning OR deep learning) AND (hip arthroscopy). Studies that investigated AI-based risk prediction models in hip arthroscopy were included. The primary outcomes of interest were the variable(s) predicted by the models, best model performance achieved (primarily based on area under the curve, but also accuracy, etc), and whether the model(s) had been externally validated (generalizable).
RESULTS: Seventy-seven studies were identified from the primary search. Thirteen studies were included in the final analysis. Six studies (n = 6,568) applied AI for predicting the achievement of minimal clinically important difference for various patient-reported outcome measures such as the visual analog scale and the International Hip Outcome Tool 12-Item Questionnaire, with area under a receiver-operating characteristic curve (AUC) values ranging from 0.572 to 0.94. Three studies used AI for predicting repeat hip surgery with AUC values between 0.67 and 0.848. Four studies focused on predicting other risks, such as prolonged postoperative opioid use, with AUC values ranging from 0.71 to 0.76. None of the 13 studies assessed the generalizability of their models through external validation.
CONCLUSIONS: AI is being investigated for predicting clinical outcomes after hip arthroscopy. However, the performance of AI models varies widely, with AUC values ranging from 0.572 to 0.94. Critically, none of the models have undergone external validation, limiting their clinical applicability. Further research is needed to improve model performance and ensure generalizability before these tools can be reliably integrated into patient care.
METHODS: Level IV. See Instructions for Authors for a complete description of levels of evidence.

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).

The hip capsule and capsular ligaments play crucial roles in providing hip stability and mobility. Their role in hip pathologies is being increasingly recognized, underscoring the need for thorough imaging evaluation, which is better performed through MRI-arthrography. Various diseases affect the hip capsule directly or indirectly. Improper mechanical loading, as seen in conditions such as femoroacetabular impingement or chondrolabral pathology, can induce capsule thickening, whereas thinning and laxity of the capsule are characteristics of microinstability. Inflammatory conditions, including adhesive capsulitis of the hip, crystal deposition disease, polymyalgia rheumatica, and infections, also lead to capsular changes. Traumatic events, particularly posterior hip dislocations, cause capsule ligament disruption and may lead to hip macroinstability. Friction syndromes can lead to capsular edema due to impingement of the adjacent capsule. Hip arthroscopy can result in various postoperative findings ranging from fibrotic adhesions to focal or extensive capsule discontinuation. Although the significance of hip capsule thickness and morphology in the pathogenesis of hip diseases remains unclear, radiologists must recognize capsule alterations on imaging evaluation. These insights can aid clinicians in accurately diagnosing and effectively managing patients with hip conditions.

Periacetabular osteotomy is the gold standard treatment for acetabular dysplasia. The great variability of acetabular dysplasia requires a personalized preoperative planning improved by 3D reconstruction and computer-assisted surgery. To plan the displacement of the acetabular fragment by a pelvic osteotomy, it is necessary to define a reference plane and a method to characterize 3D acetabular orientation. A scoping review was performed on PubMed to search for articles with a method to characterize the acetabulum of native hips in a 3D reference frame. Ninety-eight articles out of 3815 reports were included. Three reproducible reference planes were identified: the anterior pelvic plane, the Standardization and Terminology Committee plane used in gait analysis, and the sacral base plane. The different methods for 3D analysis of the acetabulum were divided in four groups: global orientation, triplanar measurements, segmentation, and surface coverage of the femoral head. Two methods were found appropriate for reorientation osteotomies: the global orientation by a vector method and the triplanar method. The global orientation method relies on the creation of a vector from the acetabular rim, from the acetabular surface or from successive planes. Normalization of the global acetabular vector would correct acetabular dysplasia by a single alignment maneuver on an ideal vector. The triplanar method, based on angle measurements at the center of the femoral head, would involve correction of anomalies by considering axial, frontal, and sagittal planes. Although not directly fit for reorientation, the two others would help to candidate patients and verify both planning and postoperative result.

BACKGROUND: Snapping hip syndrome (SHS) is characterized by snapping sensation and pain and affects up to 10% of the general population. External snapping hip syndrome (ESHS), the most common form, is often due to repetitive movements in sports or anatomical predispositions. Conservative treatment includes physiotherapy and corticosteroid injections, while surgery is considered if conservative measures fail. Open surgical techniques carry several risks, while modern arthroscopic techniques offer less invasive options, such as endoscopic iliotibial band release (ITB) and gluteus maximus tenotomy.
METHODS: A systematic review was conducted adhering to the PRISMA guidelines. Relevant studies were searched in four databases: Pubmed, Scopus, Embase, and Medline. The selected articles were evaluated according to the criteria of levels of evidence. The Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) was used to analyze the retrospective studies. This paper was registered in the International Prospective Registry of Systematic Reviews (PROSPERO).
RESULTS: Out of 9 included studies, 403 patients with 689 hips underwent endoscopic treatment. ITB release and his variations were the main surgical techniques. Gluteus maximus tenotomy was also used in some studies. Postoperative rehabilitation protocols varied. Patients generally experienced significant improvements in symptoms and functional outcomes, with low rates of recurrence (1.02%) and revision (0.15%). Complications were minimal.
CONCLUSIONS: Endoscopic treatment of ESH shows favorable results, improving functional outcomes and returning patients to pre-injury activity levels. Long-term efficacy and costeffectiveness need to be evaluated, emphasizing the importance of large-scale prospective randomized trials to clarify surgery\'s benefits in refractory ESH cases.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) presents challenges in clinical management due to its chronic nature and uncertain etiology. Historically attributed to greater trochanteric bursitis, current understanding implicates abductor tendinopathy as the primary cause. Diagnosis usually involves a clinical examination and additional tests such as imaging and provocative testing. Surgical intervention may be considered for cases refractory to conservative therapy, with endoscopic techniques gaining ground over open procedures.
METHODS: A systematic review was conducted adhering to the PRISMA guidelines. Relevant studies were searched in four databases: Pubmed, Scopus, Embase, and Medline. The selected articles were evaluated according to the criteria of levels of evidence (LoE). The Coleman methodology score (mCMS) was used to analyze the retrospective studies. This systematic review was registered in the International Prospective Registry of Systematic Reviews.
RESULTS: Surgical success rates ranged from 70.6-100%, significantly improving pain and function. Complications were generally mild, mainly hematomas and seromas, while recurrence rates were low. However, limitations such as the retrospective design and the absence of control groups warrant cautious interpretation of the results.
CONCLUSIONS: Endoscopic surgery emerges as a promising option for refractory GTPS, offering effective symptom relief and functional improvement. Despite limitations, these results suggest a favorable risk-benefit profile for endoscopic procedures. Further research is needed, particularly prospective randomized trials, to confirm these findings and optimize surgical techniques to improve patient outcomes.

Radiofrequency ablation (RFA) of the articular branches of the femoral and obturator nerves (the innervation of the anterior capsule of the hip) is an emerging treatment for chronic hip pain. Body mass index (BMI) greater than 30, older age, large acetabular/femoral head bone marrow lesions, chronic widespread pain, depression, and female sex increase the risk of developing hip pain. Chronic hip pain is a common condition with a wide range of etiologies, including hip osteoarthritis (OA), labral tears, osteonecrosis, post total hip arthroplasty (THA), post-operative dislocation/fracture, and cancer. The most common and well studied is hip OA. Management of chronic hip pain includes conservative measures (pharmacotherapy and exercise), surgery, and percutaneous procedures such as RFA. While surgery is effective, those whose medical comorbidities preclude surgery, those who do not wish to have surgery, and those whose pain persists after surgery (11-36% of patients) could benefit from RFA. Because of the aforementioned circumstances, hip RFA is often a palliative intervention. Hip RFA is an effective treatment, one recent retrospective study of 138 patients found 69% had >50% pain relief at 6 months. The most frequent adverse event reported for hip RFA is pain from needle placement. No serious bleeding events have been reported, despite the valid concern of the procedure\'s proximity to vasculature. This descriptive review details the pathophysiology of hip pain, its etiologies, its clinical presentation, conservative management, the anatomy/technique of hip RFA, hip RFA efficacy, and RFA adverse events.

OBJECTIVE: Understanding the mechanisms of hip disease, such as osteoarthritis (OA), is crucial to advance their treatment. Such hip diseases often involve specific morphological changes. Genetic variations, called single nucleotide polymorphisms (SNPs), influence various hip morphological parameters. This study investigated the biological relevance of SNPs correlated to hip morphology in genome-wide association studies (GWAS). The SNP-associated genes were compared to genes associated with OA in other joints, aiming to see if the same genes play a role in both hip development and the risk of OA in other lower limb joints.
METHODS: A systematic literature review was conducted to identify SNPs correlated with hip morphology, based on the Population, Intervention, Comparison, Outcome, and Study (PICOS) framework. Afterwards, Gene Ontology (GO) analysis was performed, using EnrichR, on the SNP-associated genes and compared with non-hip OA-associated genes, across different databases.
RESULTS: Reviewing 49 GWAS identified 436 SNPs associated with hip joint morphology, encompassing variance in bone size, structure and shape. Among the SNP-associated genes, SOX9 plays a pivotal role in size, GDF5 impacts bone structure, and BMP7 affects shape. Overall, skeletal system development, regulation of cell differentiation, and chondrocyte differentiation emerged as crucial processes influencing hip morphology. Eighteen percent of GWAS-identified genes related to hip morphology were also associated with non-hip OA.
CONCLUSIONS: Our findings indicate the existence of multiple shared genetic mechanisms across hip morphology and OA, highlighting the necessity for more extensive research in this area, as in contrast to the hip, the genetic background on knee or foot morphology remains largely understudied.

Conventional radiography is regularly used to evaluate complications after total hip arthroplasty. In various recent consensus meetings, however, plain radiographs of a potentially infected hip joint have been judged as being only relevant to exclude diagnoses other than infection. Solid data on radiographic presentations of periprosthetic joint infection (PJI) are scarce. As a result, the prognostic value of radiological features in low-grade PJI remains uncertain. The present review article aims to present an overview of the available literature and to develop ideas on future perspectives to define the diagnostic possibilities of radiography in PJIs of the hip. The primary outcome of interest of this systematic review was the radiologic presentation of periprosthetic joint infections of the hip. As secondary outcome of interest served the sensitivity and specificity of the radiologic presentation of periprosthetic joint infections. Of the included articles, 26 were reviews, essays, or case reports and only 18 were clinical studies. Typical radiologic abnormalities of PJI were a periosteal reaction, a wide band of radiolucency at the cement-bone or metal-bone interface, patchy osteolysis, implant loosening, bone resorption around the implant, and transcortical sinus tracts. The frequency of their occurrence is still inadequately defined. A deeper understanding of the underlying causes and the relation between microorganisms to radiologic abnormalities can probably help clinicians in the future to diagnose a PJI. This is why further research shall focus on the radiographic features of PJI.

UNASSIGNED: Hip pain is a common concern among athletes. With gluteal tendinopathy, femoroacetabular impingement, and osteoarthritis predominating sports medicine and musculoskeletal practices, less common etiologies may be overlooked. Complex pelvic anatomy and variable pain referral patterns may make identifying an accurate diagnosis challenging. Employing a systematic approach to evaluation and having a thorough understanding of hip region anatomy are essential. A potentially overlooked cause of anterolateral hip pain is iliotibial band origin tendinopathy. Patients often present with pain around the anterolateral hip and tenderness to palpation at the anterolateral iliac crest. While patients with iliotibial band origin tendinopathy usually respond to nonsurgical intervention, there is little literature to guide evaluation and treatment, highlighting a gap in the recognition of this condition. The purpose of this narrative review is to describe the anatomy of the proximal iliotibial band origin, outline the clinical diagnosis and imaging findings of ITBOT, and summarize current treatment options.