UNASSIGNED: Transient osteoporosis of the hip (TOH) is a poorly recognized self-limiting clinical entity. Due to a lack of awareness among the clinicians, the condition is often misdiagnosed leading to inappropriate treatment, thereby lengthening the time to diagnosis (TTD). In this study, we analyze the delay in TTD of TOH using plain radiographs and present the optimal management strategy.
UNASSIGNED: We retrospectively collected the data of patients who were diagnosed with TOH from March 2017 to March 2022. A total of 10 patients with a mean age of 43.7 years (range 33-56 years) were included in the study. The mean time to presentation from the onset of symptoms was 4 weeks (range 2-8 weeks) Radiologic evaluation with radiographs was sensitive in only 8 patients with osteopenia, whereas magnetic resonance imaging (MRI) was sensitive in all the patients and aided in early diagnosis of TOH. Radiographic evaluation alone leads to a mean delay in TTD of 1.6 weeks (range 0-8 weeks) in our study. All the patients were treated conservatively without any major complications.
UNASSIGNED: Plain radiographs were not sensitive in the early detection of TOH and increased the TTD by 1.6 weeks, however, MRI imaging was found to be highly sensitive and specific in diagnosing TOH.

OBJECTIVE: Transient osteoporosis of the hip (TOH) is an uncommon, typically self-limited diagnosis of uncertain etiology. We hypothesize that TOH represents an underlying subchondral fracture, and a discrete fracture line can often be detected on high-resolution MRI.
METHODS: A retrospective PACS query identified patients meeting imaging criteria for TOH with intense bone marrow edema (BME) in the femoral head on MRI. Those with poor quality studies, other underlying pathologies, or antecedent trauma were excluded. Three musculoskeletal radiologists independently reviewed each case for presence of a definite subchondral fracture line on small field of view (FOV) MR images of the affected hip. Extent of BME, reciprocal acetabular BME, and joint effusion size were also recorded. Binomial logistic regression was performed to determine statistically significant predictors of subchondral fracture.
RESULTS: Fifty patients met inclusion criteria (29 females, 0 pregnant). Mean age was 62±12 years (range 35-84). Average duration of symptoms before MRI was 102±135 days. Ten patients had bone densitometry within 2 years of MRI, six demonstrating osteopenia or osteoporosis. Subchondral fractures were unanimously identified in 44/50 (88%). Interclass correlation coefficient with absolute agreement was 0.73, 95% CI (0.57-0.84), indicating near-excellent agreement. Most cases demonstrated a large joint effusion (23/50, 46%) and acetabular BME (31/50, 62%). Increasing size of joint effusion was a statistically significant predictor of subchondral fracture (p=0.05), with 6.9 higher odds. There was a strong correlation with osteopenia/osteoporosis and fracture (p<0.001).
CONCLUSIONS: Discrete subchondral fractures were identified unanimously on small FOV imaging in the majority of TOH cases.

BACKGROUND: Transient osteoporosis of the hip, or acute bone marrow edema syndrome, is a rare condition characterized by a decrease in bone mineral density of the proximal femur, which resolves with conservative management over 6-24 months. At presentation, the patient complains of sudden onset of localized pain in the hip, which is aggravated by weight-bearing. However, the prevalence and risk factors for this condition are still unclear. Objective: This study aims to identify the prevalence of transient osteoporosis of the hip among patients who present with hip pain and underwent magnetic resonance imaging of the hip.
METHODS: This is a retrospective investigation that involved collecting data from patients\' records in a tertiary hospital in Saudi Arabia. Included candidates were patients who presented with hip pain, had an MRI done between 2016 and 2019 inclusive, and were older than 14 years. The collected data involved the age and gender of patients, the hip\'s affected side, and the diagnosis. Data analysis was executed through SPSS version 26 (IBM Corp., Armonk, NY).
RESULTS: Three hundred and fourteen patients matched our inclusion criteria. The prevalence of transient osteoporosis of the hip was 2.5%. All of them were males and half were above 40 years, 50% had pain in the left side, and 75% had a small joint effusion. The femoral head was the most affected part of the joint in patients with transient osteoporosis of the hip. Among our patients, the most common cause of hip pain was gluteus medius tendonitis (12.9%), where 33.1% of patients with hip pain had normal examination and investigations, and 15.2% had more than one condition. Risk factors for transient osteoporosis of the hip are pain in the left hip joint (p-value=0.023) and an age between 41 and 50 years (p-value=0.012).
CONCLUSIONS: The prevalence of transient osteoporosis of the hip is low, yet it requires confirmation by studies with a more robust design. Males older than 40 years and left-side hip pain are at higher risk.

Physicians are the occupation at risk for Transient Osteoporosis of the Hip. Therefore, sudden hip pain in them should be further evaluated with magnetic resonance imaging. Conservative treatment may help avoid further injury and speed up healing.

Transient osteoporosis of the hip, idiopathic, is a table, beginning with hip pain without a history of trauma, usually self-limiting and seen in middle-aged men and pregnant women. In this case report, a male patient who was admitted because of hip pain and detected transient osteoporosis go the hip was discussed. The purpose of the case presentation is to emphasize the necessity of transient osteoporosis of the hip in the differential diagnosis of sudden onset of hip pain and to review the literature on this subject.

BACKGROUND: Transient osteoporosis of the hip (TOH) is a rare and temporary clinical condition characterised by bone marrow edema (BME), severe pain, and functional limitation. It commonly occurs in middle-aged men or in women in the last trimester of pregnancy. TOH usually resolves with conservative therapy but may predispose to hip fracture or progression to avascular necrosis (AVN). Etiology is still unclear, although several pathophysiological mechanisms underpinning this condition has been proposed. We describe the management of an unusual case of TOH occurred in a patient with subclinical hypothyroidism.
METHODS: A clinical case of a 46-year-old man with severe pain in the left anterior thigh is presented. After a comprehensive clinical and radiological approach, a TOH was diagnosed. Moreover, biochemical assessment suggested the presence of subclinical hypothyroidism. After 3 months of treatment with clodronate, physical therapy and hormone replacement therapy (HRT) a significant improvement of clinical and radiological outcomes was observed.
CONCLUSIONS: Several pathological conditions have been related to development of TOH. In our case, we suggested for the first time a role of subclinical hypothyroidism as novel contributory factor for the onset of this condition, providing pathophysiological mechanisms and a scientific rationale for pharmacological treatment.

Bone marrow edema syndrome (BMES) is a highly uncommon, self-limited syndrome of unclear etiology. The syndrome most commonly affects middle-aged men. Magnetic resonance imaging is essential for the diagnosis because of the characteristic pattern of bone marrow edema. The diagnosis of BMES is a challenge for clinicians. Other causes of lower extremity pain, with poor prognosis, must be excluded. We present three cases of BMES. All three patients initially complained of mild lower extremity pain, which progressively deteriorated and led to a severe limitation of their daily activities. They were all treated conservatively by weight-bearing restriction and symptoms resulted within a few months. The aim of the present study is to outline this rare, benign pathology.

Transient osteoporosis is a rare manifestation of acute hip pain which typically resolves with weight-bearing restrictions and pain management. Our case report presents a patient who experienced atraumatic right hip pain a few weeks after an uncomplicated bariatric surgery and was diagnosed with transient osteoporosis of the hip. Her condition resolved after weeks of protected weight-bearing restrictions and nonsteroidal anti-inflammatories. Transient osteoporosis should be considered in the differential diagnosis of hip pain in patients who have undergone previous bariatric surgery.

BACKGROUND: Transient osteoporosis of the hip (TOH) is a poorly understood and forgotten clinical entity. The diagnosis is often delayed, and inappropriate treatment is provided, due to the lack of its awareness among the clinicians.
METHODS: Twelve patients (11 male and one female) within the age group of 35-50 years, were identified retrospectively from the hospital records between July 2011 and June 2015 who had evidence of TOH on clinical and radiological parameters.
RESULTS: All the patients were treated conservatively by nonweight bearing mobilization, anti-inflammatory drugs, bisphosphonates, calcium, and Vitamin D supplements. None of our patients had any symptoms after 6 months of conservative management. The disease did not progress, and there was no evidence of hip joint involvement in any of the cases. Plain radiographs were not diagnostic in the early detection of TOH. Magnetic resonance imaging was found to be highly specific and sensitive in diagnosing TOH. The clinical condition of TOH is characterized by its acute onset of hip pain in middle-aged people, and its symptoms are out of proportion to the radiological findings.
CONCLUSIONS: The TOH is a nondestructive and self-limiting condition of the hip, which responds well to the conservative treatment. We believe that TOH could be a subset of complex regional pain syndrome type 1, as it has many similarities in clinical presentation and management. Awareness of this entity is important to the clinicians for an early diagnosis and to avoid unnecessary treatment for other mimicking conditions.

BACKGROUND: Transient osteoporosis of the hip (TOH) is a self-limiting disorder characterized by bone marrow edema at the femoral head and neck. Patients report pain as moderate or severe at onset; pain gradually subsides at about six months (range four to 12 months). Differential diagnosis of the early stages of osteonecrosis of the femoral head (ONFH) is sometimes difficult. Because hyperbaric oxygen (HBO₂) therapy is effective for reduction of edema in soft tissue injury and early stages of ONFH, we hypothesized that HBO₂ could be effective in TOH for accelerated recovery.
METHODS: Five cases of TOH treated with HBO₂ were clinically evaluated. HBO₂ was started from three to eight weeks after onset and performed four or five times a week, averaging a total of 27.8 ± 4.7 treatments (range 20-32). Clinical features were evaluated repeatedly with clinical examination, subjective evaluation of pain, and imaging methods that included magnetic resonance imaging (MRI) and bone scans.
RESULTS: The average time to return-to-normal hip range of motion was 15.4 ± 7.8 weeks after onset, and relief of subjective pain was 16.6 ± 4.0 weeks. The average time to return-to-normal signal level in MRI was 22.0 ± 2.5 weeks, which was one to two months after relief of subjective pain.
UNASSIGNED: Multiple HBO₂ treatments have the possibility of contributing to recovery acceleration in patients with TOH. However, in this study, we found that HBO₂ treatment did not significantly accelerate the recovery of these five patients with TOH. The use of HBO₂ should therefore be limited to patients in whom the differential diagnosis between TOH and early stage ONFH cannot be established.