This study reviews the evidence for point-of-care ultrasound (POCUS) for the detection of hip effusion in children presenting to the emergency department with atraumatic limp or hip pain. A scoping review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review (PRISMA-ScR) guideline. PubMed, EMBASE, and the Cochrane Library databases were searched from January 2000 to October 2025. All study designs were considered. The primary outcome was diagnostic accuracy of POCUS for hip effusion, and key secondary outcomes included provider characteristics and clinical integration. Data were also charted across study, participant, and ultrasound characteristics. Thirteen studies met inclusion criteria: 3 prospective studies, 9 retrospective cohorts, and 1 case report. Studies predominately evaluated diagnostic accuracy of POCUS performed by emergency medicine physicians with variable training compared with radiology performed ultrasound, feasibility of POCUS guided hip arthrocentesis, and explored its integration into clinical decision rules. Diagnostic accuracy was high, with reported sensitivity ranging from 80% to 98% and specificity from 91% to 98%. This scoping review demonstrates that there is growing evidence that hip POCUS is a useful clinical tool for evaluation of pediatric patients presenting to the emergency department with atraumatic limp or hip pain. It has been shown to be accurate when performed by emergency physicians after variable training. Further research is required with large prospective multicenter studies to explore patient-centered outcomes and validate diagnostic pathways that incorporate POCUS.

Osteochondromas are the most common benign bone tumors, but pelvic involvement is rare. We present a case of an iliac osteochondroma manifesting with atypical hip pain, adding to the limited literature on pelvic osteochondromas and highlighting the diagnostic and management challenges of such cases in an athletic population. A 28-year-old male presented with progressive right greater trochanteric area pain, predominantly nocturnal and exacerbated by running and football but absent during cycling. Physical examination and ultrasound revealed no abnormalities. CT and MRI revealed a pedunculated osseous mass arising from the anterosuperior ilium with cortical and medullary continuity, consistent with osteochondroma. MRI demonstrated a thin cartilage cap (< 2 cm) and local irritation of the iliopsoas. Analgesic therapy, sacroiliac joint injection, and physiotherapy failed to provide relief. After discussion in a multidisciplinary oncology board, the patient underwent en bloc excision. Prognosis was considered favorable given the absence of aggressive imaging features. This case emphasizes that nocturnal hip pain and activity-dependent symptom modulation in a recreational athlete are atypical for the far more common musculotendinous causes of hip pain and should prompt clinicians to consider underlying osseous pathology. Further, it illustrates the importance of multimodality imaging in osteochondromas for accurate characterization and supports the role of multidisciplinary tumor boards in guiding management of rare benign bone tumors.

Osteonecrosis of the femoral head (ONFH) remains a challenging condition in orthopaedics[1]. Free vascularized fibular grafting (FVFG) theoretically has the potential to restore blood supply to the femoral head and enhance mechanical stability within the femoral head. This method has shown promising clinical outcomes in hip preservation. Previous studies have utilized the anterolateral approach to the hip for this surgical procedure. Here, we report a minimally invasive technique utilizing the direct anterior approach for debridement and bone grafting, requiring a shorter fibular graft and simplifying the procedure. This method holds potential as an effective treatment option for early to mid-stage femoral head necrosis[2].

Transient osteoporosis of pregnancy (TOP) is a rare condition that typically presents during the third trimester as unexplained lower limb joint pain, most commonly involving the hip. We report an uncommon case of TOP affecting both ankles and provide a literature review of previously reported cases involving the ankle. A 31-year-old Japanese woman developed bilateral ankle pain in the second trimester of pregnancy without any history of trauma. She presented to the orthopedic outpatient clinic in the postpartum period, and her radiographs revealed bilateral diffuse osteopenia, which brought her to our rheumatologic department. Additional radiographic evaluation of the spine and hips showed no evidence of osteopenia. Magnetic resonance imaging of the right ankle, which was obtained for worsening pain, demonstrated bone marrow edema. Blood tests, which evaluated inflammatory markers and alkaline phosphatase, and a musculoskeletal ultrasound were unremarkable. The patient's symptoms gradually resolved with conservative management, including vitamin D supplementation, intermittent use of nonsteroidal anti-inflammatory drugs, and rest. At three months postpartum, radiographs showed partial improvement of osteopenia, whereas MRI still demonstrated bone marrow edema. Follow-up radiographs at eight months demonstrated resolution of the patient's osteopenia, which was consistent with a diagnosis of TOP. We also reviewed previously reported cases of TOP affecting the ankles, identifying eight cases in total. Clinicians should consider the possibility of TOP in pregnant or postpartum women presenting with unexplained joint pain in the lower limbs, including the ankles, even when the pain appears during the second trimester of pregnancy. TOP carries a risk of fracture, making timely and appropriate conservative management essential. Although based on a single case, these findings may indicate that radiographs could reflect recovery earlier than MRI, and may be useful as a follow-up imaging modality in TOP affecting the ankles.

This study compared the volume of acetabular bone resection between an anatomically designed cementless ceramic-on-ceramic hip resurfacing arthroplasty (H1HR) and metal-on-metal hip resurfacing (Birmingham Hip Resurfacing; BHR). We hypothesized that the anatomical design of the H1 cup would reduce the need for medialization to avoid rim overhang, thereby preserving acetabular bone stock. A retrospective three-dimensional simulation study was performed in 12 hips with osteoarthritis and femoral head size ≥ 48 mm. H1HR and BHR were virtually implanted using 3D planning software to minimize the risk of groin pain. The primary outcome was the volume of acetabular bone resection. Secondary outcomes included the position of the cup relative to the native hip centre and the cup non-coverage ratio. H1 cups required a mean volume of acetabular bone resection of 11 cm3, while BHR cups required 17 cm3. This 35% reduction was statistically significant. H1 cups had less medialization (-1 mm vs. -6 mm), superior displacement (-1 mm vs. -2 mm), and posterior displacement (-1 mm vs. -3 mm). The mean cup non-coverage ratio was not significantly different (10% vs. 8%). The anatomically designed H1HR achieved a significant 35% reduction in acetabular bone resection compared with BHR. This substantial volume of bone preservation was primarily attributed to the design enabling cup placement with minimal medialization, without increasing the cup non-coverage ratio. Although further validation in cadaveric or postoperative imaging studies is needed, H1 may be a promising option for bone preservation, particularly for young, active patients who might require future revision surgery.