Transient osteoporosis of the hip: A case report

We report a case of transient osteoporosis of the hip (TOH) in a 59-year-old man including the clinical presentation, diagnostic studies, management and clinical progress. TOH is a rare self-limiting condition that typically affects middle-aged men or, less frequently, women in the third trimester of pregnancy. Affected individuals present clinically with acute hip pain, limping gait, and limited ranges of hip motion. TOH may begin spontaneously or after a minor trauma. Radiographs are typically unremarkable but MR imaging studies yield findings consistent with bone marrow edema. TOH is referred to as regional migratory osteoporosis if it travels to other joints or the contralateral hip. TOH often resembles osteonecrosis but the two conditions must be differentiated due to different prognoses and management approaches. The term TOH is often used interchangeably and synonymously with transient bone marrow edema.     

8例髋关节暂时性骨质疏松症的临床诊断与治疗

目的探讨髋关节暂时性骨质疏松症（transient osteoporosis of the hip,TOH）的临床表现、诊断、鉴别诊断、治疗及预后。方法2003年8月至2009年8月治疗8例TOH患者,男2例,女6例;年龄22—43岁,平均34．9岁。患者均为单侧发病,左侧5例,右侧3例。患者的患髋均表现有不同程度的突发急性疼痛或渐进性疼痛,同时伴有显著的跛行。患髋内旋轻度受限是主要的体征。症状出现后3—6周,x线片可见股骨头均匀广泛的骨质疏松,MR表现为弥散且一致的等低T1、长T2异常信号,脂肪抑制序列呈高信号。嘱患者在疼痛可忍受的条件下半负重行走,避免出现骨折等并发症;口服二膦酸盐和钙剂;剧烈疼痛时,可口服非甾体类抗炎药物缓解疼痛。结果临床治疗3个月后疼痛明显减轻,10个月后疼痛完全缓解,复查MR示病变完全消失。结论TOH是一种少见的疾病,无原因出现的髋关节疼痛和跛行是主要症状,X线片和MR可分别看到暂时性的骨质疏松和骨髓水肿。此病具有自限性,保守治疗可获得良好的结果,明确诊断是治疗的关键。     

Bilateral Transient Osteoporosis of the Hip in a Young Man

Transient osteoporosis of the hip (TOH) is a rare disorder of unknown cause that is characterized by diffuse bone marrow edema of the femoral neck and head. A case of bilateral TOH occurring in a 32-yr-old man is reported and the radiological findings and bone densitometry that illustrate the natural history of this disorder are presented. The management of this disorder including the possible indications for antiresorptive therapy is reviewed.     

Regional migratory osteoporosis: a case report

We describe a case of regional migratory osteoporosis (RMO) with clinical images clearly illustrating the migratory behavior of this unusual disorder. RMO is a relatively rare disorder that manifests as rapidly developing, self-limiting, reversible osteoporosis typically seen in the lower limbs of middle-aged men. In our case, the lesion was observed migrating not only from the knee to the ankle within the same limb but also within two compartments of the same knee. To our knowledge, this is the first case showing migration of a lesion both within the same joint and to the adjacent joint. We also present computed tomography images showing characteristic spotty bone defects that are rarely described in the literature, along with magnetic resonance imaging scans revealing bone marrow edema in the affected region. Although little is understood about the etiology or treatment of RMO, knowledge of this disorder is mandatory to avoid its misdiagnosis as some other, more aggressive disease, leading to unnecessary treatment.     

Three cases of regional migratory osteoporosis

We examined three patients with regional migratory osteoporosis. Radionucleotide bone scanning and MRI was helpful in the diagnosis of this disease, and all patients recovered with conservative treatment. A biopsy of the femoral head, which was performed in one case, demonstrated bone marrow edema without osteonecrosis. A low intensity area of subchondral bone was observed on a T1-weighted image in two cases, as well as a fracture of the subchondral bone, which might be associated with transient osteoporosis. In one case, the affected region migrated from the medial femoral condyle to the lateral femoral condyle in the same knee joint.     

Transient osteoporosis

Transient osteoporosis is characterized primarily by bone marrow edema. The disease most commonly affects the hip, knee, and ankle in middle-aged men. Its cause remains unknown. The hallmark that separates transient osteoporosis from other conditions presenting with a bone marrow edema pattern is its self-limited nature. Laboratory tests usually do not contribute to the diagnosis. Plain radiographs may reveal regional osseous demineralization. Magnetic resonance imaging is used primarily for early diagnosis and monitoring disease progression. Early differentiation from more aggressive conditions with long-term sequelae is essential to avoid unnecessary treatment. Clinical entities such as transient osteoporosis of the hip and regional migratory osteoporosis are spontaneously resolving conditions. However, early differential diagnosis and surgical treatment are crucial for the patient with osteonecrosis of the hip or knee.     

髋部暂时性骨质疏松症发病机制研究进展

髋关节暂时性骨质疏松症(transient osteoporosis of the hip,TOH)被归类为骨髓水肿综合征的一种。TOH既往研究不少,对其发病机制存在争议。近年来随着影像学、病理学、分子生物学等多学科的发展,研究发现该病发病机制较复杂且不明确,本文从神经源性、骨坏死、血管功能异常、软骨下骨折、遗传、区域性加速现象等方面对TOH的相关发病机制的研究进展进行了概括。     

Transient osteoporosis of hip in pregnancy.

Transient osteoporosis in pregnancy is a relatively rare disorder characterized by disabling pain in the hip without prior trauma and by striking radiographic evidence of osteopenia that is limited to the hip. Clinical and radiographic findings regress spontaneously within months after pregnancy and without late sequelae. In this study, we report on a case of a 28-yr-old Caucasian woman who suffered from transient osteoporosis during pregnancy. Nine months later, the patient was asymptomatic and there was resolution of the bone marrow edema pattern seen on the initial magnetic resonance imaging scan of her hip. Follow-up bone densitometry at 1 yr revealed a dramatic increase (12.3%) in bone mineral density of the symptomatic hip. We review the literature and discuss possible mechanisms involved in the pathogenesis of transient osteoporosis in pregnancy.     

"Transient osteoporosis" as a special reversible form of femur head necrosis

There is still controversy whether transient osteoporosis of the hip joint represents a distinct self-limiting disease, or reflects only an early, reversible subtype of non-traumatic osteonecrosis (ON). Transient osteoporosis has several synonyms: algodystrophy of the hip; transient marrow oedema; or bone marrow oedema syndrome--BMOES. Clinical presentation of BMOES shows mechanical hip joint pain, ON risk factors, and a diffuse bone marrow oedema in MR imaging. Histomorphological changes resemble early ON, but with diffuse sufficient repair in BMOES and focal and insufficient repair only at the border of the necrotic lesion in ON. Therefore the clinical course and outcome are significant different, with restitution occurring in BMOES, while progressive destruction of the joint takes place in ON. So far, the preferred treatment strategies are protected weight bearing for BMOES, but operative treatment for ON. In a prospective study of patients with BMOES, the clinical, radiographic, and MRI course of 43 hip joints after core decompression treatment were investigated. All patients showed immediate relief of pain after surgery and the average duration of symptoms with conservative treatment could be dramatically reduced by core decompression from 6 months down to 2 months. There were no perioperative complications. Based on our experience with over 100 BMOES patients, we are convinced that this syndrome represents not a distinct disease but an early reversible subtype of non-traumatic ON. Due to the excellent clinical results of core decompression, we recommend this operative therapeutical concept in patients with painful BMOES.     

Pregnancy-related hip diseases: incidence and diagnoses

BackgroundPregnancy-related hip diseases epidemiology has been poorly evaluated. We report our experience of gestational and postpartum hip diseases and evaluate their incidence.Methods(1) Prospective survey: all pregnant or early postpartum women suspected to have hip involvement during their follow-up in an Obstetric unit were referred to a rheumatologist. If clinically confirmed, magnetic resonance imaging (MRI) and additional investigations as needed were performed. This survey had 2 years duration. (2) Retrospective study: all cases of definite (with MRI confirmation) pregnancy-related hip disease referred to our Rheumatology unit during the past 15 years were analyzed.ResultsDuring the 2-year prospective survey, 3 patients (4 hips) of pregnancy-related hip disease were observed over 4900 pregnancies (1 case of transient osteoporosis of the hip (TOH) and 2 cases of occult fracture of the femoral head). During the 15-year retrospective study, 12 patients (17 hips) with hip diseases during pregnancy or early postpartum were identified. There were 6 patients (9 hips) with TOH, 4 patients (6 hips) with occult fracture of the femoral head, 1 patient with osteonecrosis of the femoral head, and 1 coxitis in a patient with ankylosing spondylitis. Differentiating diagnosis between TOH and occult fractures could only be made by MRI. Five of the 6 women with TOH had osteopenia at the lumbar spine at dual energy X-ray absorptiometry (DEXA). The 4 women with occult fractures had either osteopenia or osteoporosis at the lumbar spine.ConclusionHip diseases are infrequent during pregnancy and early postpartum. Transient osteoporosis of the hip and occult stress fractures of the femoral head appear the main causes and those diagnoses justify evaluation for an underlying bone fragility. Osteonecrosis is very rare in this setting.     

Radiological morphology variances of transient osteoporosis of the hip

Background

Although several morphological abnormalities or variances of the hip joint have been proposed to be associated with hip joint degeneration, few studies have investigated any radiological features in patients with transient osteoporosis of the hip (TOH). The purpose of this study is to evaluate the morphological variances of the hip joint in TOH patients radiographically.

Bone Loss and Recovery in Regional Migratory Osteoporosis

Regional migratory osteoporosis (RMO) is a migrating arthralgia of the weight-bearing joints of the lower limb associated with focal osteoporosis. Little information is available on a quantitative assessment of systemic or local osteoporosis. In this study, we report three cases of RMO in which spine, hip and whole body serial assessments of bone mass have been evaluated to outline their extent and time course of changes. Systemic osteoporosis, with a prevalent involvement of the mainly trabecular skeletal sites, was present in all the patients, with T-scores below −2.5 at both the lumbar spine and femoral neck. Bone loss in acute episodes ranged from −75.5% to −14.7% and appeared related to the severity of the episode. In acute episodes the demineralizing process affected the whole limb from the hemipelvis to the foot: the bone loss ranged from −33.6% to −3.5% at sites with prevalent trabecular composition and from −19.1% to −1.1% at sites with prevalent cortical composition. Bone recovery was complete in one episode out of six. In the other five cases, the average residual bone loss was 26% (range 13.9–32.7%). Our observations suggest that RMO occurs in subjects with systemic osteoporosis and densitometric assessment may aid in the clinical management. Received: 12 February 2002 / Accepted: 17 June 2002 Correspondence and offprint requests to: Carlo Trevisan, MD, Clinica Ortopedica, Università degli Studi di Milano Bicocca, Azienda Osp.S.Gerardo, Via Donizetti, 106-20052 Monza (MI), Italy. Tel: +39 039 2332322. Fax +39 039 2302905. e-mail: trevisan@progetto3000.it     

The transitory bone marrow edema syndrome of the hip

AIM OF THE STUDY: Since MRI-studies had begun to establish the diagnosis of transitory bone marrow edema syndrome of the hip orthopedic surgeons have tried to integrate this new syndrome into the internationally accepted system of musculoskeletal diseases. Particularly, the relation to non-traumatic osteonecrosis of the femoral head and the possibilities in therapy were investigated in our clinical trial. METHODS: Our clinical trial encompassed 106 patients suffering from the transitory bone marrow edema syndrome diagnosed in our department between the years 1985 and 2000. In order to confirm this diagnosis we used the patients' histories, their clinical courses, MRI studies, scintigraphic bone scans, intraosseal pressure measurements, phlebographies, laboratory data, and histologic specimens. One half of our collective positive for transient bone marrow edema of the hip underwent core-decompression surgery (50 patients), the other half (56 patients) was treated conservatively by analgesic medication combined with restriction of weight-bearing in the affected extremity. RESULTS: Patients positive for transitory bone marrow edema syndrome of the hip are middle-aged individuals with a male to female predominance of 60 : 40. This group has no or only few risk factors usually associated with osteonecrosis of the femoral head. Thus, the missing alcoholic abuse is striking. All patients suffering from transitory bone marrow edema syndrome of the hip recovered completely independent of the therapy we initiated and none of them showed any signs of osteonecrosis. The one half undergoing surgical decompression of the edema by using a 4.5 mm drill experienced an markedly accelerated relief of their clinical symptoms as well as their signal changes on MRI studies. Conventional X-ray pictures and scintigraphic bone scans are not useful for early differentiation between early stages of osteonecrosis and bone marrow edemas. This also accounts for the historical measurements of intraosseal pressure determinations and phlebographies. In contrast to that, MRI studies are effective in early differentiation between osteonecrosis and bone marrow edema syndrome of the hip, especially when contrast medium (gadolinium) is administrated intravenously and fat-suppressed MRI-sequences find use. Beginning osteonecrosis of the femoral head shows a segmental loss of contrast medium, a "double line sign" interface to the intact bone marrow, and only in a few cases they are associated with a huge symptomatic edema. The histologic examination of specimens obtained from 43 patients with transitory bone marrow edema syndrome of the hip revealed no signs of osteonecrosis. CONCLUSION: MRI studies are useful in differentiation between bone marrow edema syndrome of the hip and non-traumatic osteonecrosis of the femoral head in each stage of these two diseases. The thorough differentiation between these two diseases is of extraordinary importance for the clinical work-up of the patients as well as for scientific reasons. The course of primary bone marrow edema is benign as it results in entire recovery. The core decompression surgery offers the chance to shorten the course of the disease.     

Magnetic resonance imaging in diagnosis of transient osteoporosis of the hip.

The results of magnetic resonance (MR) imaging in six patients with transient osteoporosis of the hip were reviewed. Short TR/TE (repetition time/echo time) images demonstrated diffusely decreased signal intensity in the femoral head and intracapsular region of the femoral neck. Increased signal intensity was noted with progressive T2 weighting. Bone biopsies were performed in four patients. Histologic findings were nonspecific and included fat necrosis, marrow edema, increased bone resorption, and reactive bone formation. Repeat MR scans in two patients, performed six and eight months after the initial scans, showed an almost complete return to normal marrow signal. All patients became asymptomatic without bony deformity. In the appropriate clinical setting, MR scanning can aid in the diagnosis of transient osteoporosis as the cause of a painful hip.     

股骨上端骨髓水肿综合征的MRI表现特点

目的：分析股骨上端骨髓水肿综合征的MRI表现特点以提高对该病的认识。方法;回顾性分析10例股骨上端骨髓水肿综合征患者的MRI表现,男6例,女4例;年龄36～57岁,平均41．5岁;病史1周～3个月。临床表现为突然发作的髋部疼痛9例,行走能力及髋关节活动受限7例;全部病例无明显外伤史,女性患者未在孕期。随访3～12个月,症状消失3个月复查MRI后结束随访。结果：MRI主要表现为弥漫性骨髓水肿,累及股骨头、颈、粗隆间,10例13髋中骨髓水肿1级6髋,2级5髋,3级2髋。合并髋关节积液9髋,I级积液6髋,Ⅱ级1髋,III级2髋。治疗3-12个月后患者髋部疼痛症状消失,股骨内MRI信号恢复正常。     

Distinguishing transient osteoporosis of the hip from avascular necrosis.

INTRODUCTION: To review the circumstances surrounding the misdiagnosis of transient osteoporosis of the hip (TOH) as avascular necrosis (AVN) and to increase physician awareness of the prevalence and diagnosis of this condition in young men, we reviewed a series of cases seen in the orthopedic unit at St. Michael's Hospital, University of Toronto. METHODS: We studied the charts of patients with TOH referred between 1998 and 2001 with a diagnosis of AVN for demographic data, risk factors, imaging results and outcomes. RESULTS: Twelve hips in 10 young men (mean age 41 yr, range from 32-55 yr) were identified. Nine men underwent magnetic resonance imaging (MRI) before referral, which showed characteristic changes of TOH. All 10 patients were referred for surgical intervention for a diagnosis of AVN. The correct diagnosis was made after reviewing patients' charts and the scans and was confirmed by spontaneous resolution of both symptoms and MRI findings an average of 5.5 months and 7.5 months, respectively, after consultation. CONCLUSIONS: Despite recent publications, the prevalence of TOH among young men is still overlooked and the distinctive MRI appearance still misinterpreted. Symptoms may be severe but resolve over time with reduced weight bearing. The absence of focal changes on MRI is highly suggestive of a transient lesion. A greater level of awareness of this condition is needed to differentiate TOH from AVN, avoiding unnecessary surgery and ensuring appropriate treatment.     

Transient osteoporosis of the navicular bone in a runner

Introduction Transient osteoporosis or the bone marrow oedema syndrome is described as a self-limiting disorder. Transient osteoporosis usually affects only one bone, predominantly the proximal femur. Involvement of the foot is rare and often overlooked. A disorder of the navicular bone of the foot can be found twice in the literature.Materials and methods We report a case of transient osteoporosis of the navicular bone of the foot in a 20-year-old, female, top-level track athlete (400 m sprinter) treated with alendronate, and a review of the literature.Results The therapeutic options are limited, frequently consisting of non-specific, symptomatic therapy. Some authors report favourable results with core decompression, while others have reported good results with a conservative regime of symptomatic treatment and avoidance of weight-bearing until the clinical and radiological changes have resolved. In the described case, the patient had a favourable result after a short course of treatment with alendronate. She experienced almost immediate pain reduction and presented a complete resolution of the abnormal signal intensity on MRI.Conclusion This rapid result makes the use of alendronate seem promising in athletes with transient osteoporosis, permitting an early return to high-level activities.     

Differences in Site-Specific Fracture Risk Among Older Women with Discordant Results for Osteoporosis at Hip and Spine: Study of Osteoporotic Fractures

To examine the fracture pattern in older women whose bone mineral density (BMD) T-score criteria for osteoporosis at hip and spine disagree, hip and spine BMD were measured in Study of Osteoporotic Fractures participants using dual energy X-ray absorptiometry (DXA). Hip osteoporosis was defined as T-score ≤−2.5 at femoral neck or total hip, and spine osteoporosis as T-score ≤−2.5 at lumbar spine. Incident clinical fractures were self-reported and centrally adjudicated. Incident radiographic spine fractures were defined morphometrically. Compared to women with osteoporosis at neither hip nor spine, those osteoporotic only at hip had a 3.0-fold age- and weight-adjusted increased risk for hip fracture (95% confidence interval [CI]: 2.4–3.6), and smaller increases in risk of nonhip nonspine (hazard ratios [HR] = 1.6), clinical spine (odds ratio [OR] = 2.2), and radiographic spine fractures (OR = 1.5). Women osteoporotic only at spine had a 2.8-fold increased odds of radiographic spine fracture (95% CI: 2.1–3.8), and smaller increases in risk of clinical spine (OR = 1.4), nonhip nonspine (HR = 1.6), and hip fractures (HR = 1.2). Discordant BMD results predict different fracture patterns. DXA fracture risk estimation in these patients should be site specific. Women osteoporotic only at spine would not have been identified from hip BMD measurement alone, and may have a sufficiently high fracture risk to warrant preventive treatment.     

Increased perfusion of the femoral head in transient bone marrow edema syndrome

The pathophysiology of transient bone marrow edema syndrome is not known. Ischemia has been suggested as the pathophysiologic factor, because the histologic findings are similar to those of early stage osteonecrosis. Angiographic studies of osteonecrotic femoral heads have shown arterial interruption and impaired perfusion. The current report describes the angiographic and scintigraphic findings of transient bone marrow edema syndrome of the hip in a 45-year-old man. The nutrient arteries were dilated, and the femoral head perfusion was increased compared with the unaffected contralateral side. These findings suggest that a vasomotor response plays a role in the pathogenesis of transient bone marrow edema syndrome. The disease might be a reversible process after temporary ischemia of the femoral head.