Transient marrow edema syndrome of the hip: results after core decompression. A prospective MRI-controlled study in 22 patients

Pathological femoral neck fracture in a male patient due to non-simultaneous bilateral transient hip osteoporosis: A case report: Statements and Declarations

We report a case of a 31-year-old man who developed a non-simultaneous bilateral transient hip osteoporosis (THO) complicated with an atraumatic undisplaced pathological femoral neck fracture (FNF) of his left hip. He was successfully treated with internal fixation on the left hip, and a follow-up Magnetic Resonance Imaging evidenced satisfactory resolution on the right side. Diagnosis and management of THO are usually challenging as symptoms before pathological FNFs might be misdiagnosed. This case highlights the importance of suspecting pathological FNFs when pain persists despite conservative treatment. Finally, surgical treatment is strongly recommended if a pathological FNF is confirmed.

Level of evidence

Level IV.

Spontaneous Bone Marrow Edema: Perfusion Abnormalities and Treatment with Surgical Decompression

Bone marrow edema (BME), also termed bone marrow lesions, is a syndrome characterized by bone pain and the appearance of high signal intensity on T2 fat-suppressed and short tau inversion recovery (STIR) MRI sequences. BME can be related to trauma or a variety of non-traumatic diseases, and current treatment modalities include non-steroidal anti-inflammatory drugs (NSAIDS), bisphosphonates, denosumab, extracorporeal shockwave therapy (ESWT), the vasoactive prostacyclin analogue iloprost, and surgical decompression. Spontaneous BME is a subset that has been observed with no apparent causative conditions. It is most likely caused by venous outflow obstruction and intraosseous hypertension. These are mechanistically related to impaired perfusion and ischemia in several models of BME and are related to bone remodeling. The association of perfusion abnormalities and bone pain provides the pathophysiological rationale for surgical decompression. We present a case of spontaneous BME and a second case of spontaneous migratory BME treated with surgical decompression and demonstrate resolution of pain and the high signal intensity on MRI. This report provides an integration of the clinical syndrome, MR imaging characteristics, circulatory pathophysiology, and treatment. It draws upon several studies to suggest that both the bone pain and the MRI characteristics are related to venous stasis, and when circulatory pathologies are relieved by decompression or fenestration, both the bone pain and the MRI signal abnormalities resolve.

Comparison of various treatment modalities for the management of bone marrow edema syndrome/transient osteoporosis in men and non-pregnant women: a systematic review

Transient osteoporosis (TO) or bone marrow edema syndrome (BMES) is a self-limited clinical condition, which affects middle-aged men and women. It can be treated with miscellaneous conservative and surgical measures, which are analyzed in this systematic review.

INTRODUCTION

BMES/TO is a transient clinical entity, which can be treated with various therapeutic modalities. The aim of our study was to assess the efficacy of different therapeutic options for the alleviation of pain and reduction of bone marrow edema (BME) in patients with BMES/TO, as well as to propose a therapeutic algorithm.

METHODS

PubMed, Scopus, Cochrane, and Google Scholar were searched. Eligibility and extraction of studies were conducted by two authors. Methodological quality assessment was carried out with the modified Delphi technique, Methodological Index for Non-Randomized Studies (MINORS) criteria, and Cochrane Collaboration's risk of bias tool. Outcomes that were compared were time of pain resolution, VAS pain scores, and BME regression on magnetic resonance imaging (MRI).

RESULTS

A total of 36 articles (880 patients) were included. Bisphosphonates had higher efficiency in less than 1-month outcomes on pain resolution compared with core decompression (CD), while iloprost was more efficient at 1-3 months compared with bisphosphonates and CD. At 3-6 months, all three of the aforementioned showed equal results on pain resolution, and at a period of 6-12 months, CD and extracorporeal shockwave therapy (ESWT) showed excellent results followed by bisphosphonates and the conservative group (CG) consisting of non-steroidal anti-inflammatory drugs (NSAIDs) and/or analgesics and/or restricted weight bearing. On MRI at 1-3 months, bisphosphonates, iloprost, and CD had relatively the same outcomes on BME resolution, with the least promising being the CG. At 3-6 months, CD seemed to have achieved the best results on the resolution of BME, followed by ESWT, CG, and bisphosphonates group. At 6-12 months, ESWT had the best outcomes compared with the conservative, bisphosphonates, and iloprost groups.

CONCLUSION

BMES/TO has been treated with many non-standardized measures due to the low number of highly reliable studies. Current literature shows promising results with regard to the reduction of the clinical course of BMES/TO, but further large multicenter randomized controlled trials, as well as standardized radiological and clinical scores, are warranted to acquire evidence-based recommendations on the therapeutic algorithm.

Influence of Vitamin D and C on Bone Marrow Edema Syndrome-A Scoping Review of the Literature

Bone marrow edema syndrome (BMES) is a rare disease with a largely unknown etiology. The aim of this scoping review is to systematically evaluate and combine the available evidence about vitamin D and C and BMES. The analysis of the manuscripts was based on country of origin, number of patients, gender, study type, epidemiology, localization, bone mineral density measurements, vitamin status and therapy. Sixty studies were included. The overall number of patients was 823 with a male-to-female ratio of 1.55:1 and a mean age of 40.9 years. Studies were very heterogeneous and of diverging scientific scope with a weak level of evidence. The hip was the most affected joint, followed by the foot and ankle and the knee; 18.3% of patients suffered from multifocal BMES. Sixteen studies reported on vitamin D levels, resulting in a high prevalence of vitamin D deficiency (47%) and insufficiency (17.9%) among BMES patients. Three BME manuscripts were associated with vitamin C deficiency. Current therapeutic interventions include conservative measures (mainly unloading), various osteoactive drugs and iloprost. In summary, data about BMES in association with vitamin status is limited. A causal relationship between vitamin D or vitamin C status, osteopenia, and BMES cannot be determined from the existing literature.

Arthroscopic procedures could delay the need for a subsequent knee arthroplasty in older patients with end-stage osteoarthritis

BACKGROUND/OBJECTIVE

Arthroscopic surgery in knee osteoarthritis is controversial with many studies refuting its efficacy in recent literature. This study aims to evaluate the mean duration to knee arthroplasty, and the effect of microfracture on the need for subsequent knee arthroplasty in patients above the age of 55 undergoing arthroscopic procedures for osteoarthritis.

METHODS

One hundred and nine consecutive patients with diagnosed osteoarthritis who underwent arthroscopic surgery performed from January 2000 to December 2012 on patients aged 55 years and above by a single surgeon were reviewed retrospectively. Demographic data, age at operation, comorbidities, perioperative details and information of subsequent total knee arthroplasty were collected and analysed.

RESULTS

There were 38 males and 71 females in our study group. The group was predominantly Chinese (51.38%), with hypertension and hyperlipidaemia being the most common comorbidities, each affecting 57.8% of our study cohort. All patients had a preoperative radiograph and a magnetic resonance imaging confirming the diagnosis of osteoarthritis associated with meniscal tears. Fifty-eight knees underwent microfracture along with arthroscopic meniscectomy. The mean follow-up duration was 127.5 months (10.5 years, range: 67-212 months). Twenty three patients (20.91%) underwent knee arthroplasties subsequently, with the mean duration to arthroplasty being 65.0 months (5.5 years, range: 7-166 months). The odds ratio of avoiding knee arthroplasty with microfracture was 1.03 (95% CI = 0.410-2.581).

CONCLUSION

Arthroscopic procedures could possibly delay the need for subsequent knee arthroplasty for approximately 65 months in older patients with osteoarthritis. However, microfracture does not affect the duration between therapeutic arthroscopy and subsequent arthroplasty. Our long-term retrospective study provides an additional step in the understanding of the impact of arthroscopic procedures and a prospective case-control study would be an ideal follow-up to fully justify the application of arthroscopic procedures to delay knee arthroplasty.

Bone Marrow Edema, Clinical Significance, and Treatment Options: A Review

Bone marrow edema (BME) is a descriptive term used to describe high-signal intensity changes detected on magnetic resonance fluid-sensitive sequences that could be attributed to a number of underlying pathologies. Regardless of the cause, physiologic remodeling of the subchondral bone can be limited because of ongoing joint forces, increased focalization of stress, and reduced healing capacity of the subchondral bone. BME is a known prognostic factor associated with pain, dysfunction, and progressive cartilage damage. This review summarizes the current known causes of BMEs, theories related to histopathological changes, and current treatment options including novel biologic surgical options.

Intraosseous injections of platelet rich plasma for knee bone marrow lesions treatment: one year follow-up

PURPOSE

Cartilage lesions are usually accompanied by subchondral bone alterations or bone marrow lesions (BMLs). BML associated with joint degeneration and cartilage lesions are considered to be predictors of rapidly progressing OA. Currently no existing treatment can fully halt OA progression. One of the approaches is an autologous, biological treatment based on the use of platelet rich plasma (PRP) injections. The purpose of this study is to assess the short-term effectiveness of intraosseous PRP injections, within the BML of individuals affected by OA, in ameliorating pain and improving knee functionality.

MATERIALS AND METHODS

The study involved 17 patients with an average age of 41.7 ± 14.3 years old. OA stage was determined using the Kellgren-Lawrence grading system by performing radiographic scanning of the knee joint before surgical intervention. Patients with K-L grade 3 knee joint OA prevailed. Patient OA history varied between one and nine years (average 5.2 ± 4.5 years). Clinical and functional state of the knee were assessed by pain visual analogue scale (VAS) score, the Western Ontario and McMaster Universities Score (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score (KOOS) which were filled out by patients previous to the surgical procedure at one, three, six and 12 months post-operatively. Before surgery, in addition to standard blood tests, serum cartilage oligomeric matrix protein (COMP) levels were tested for all patients.

RESULTS

Evaluation of preliminary results revealed a statistically significant reduction of pain based on the VAS score. A significant improvement was also observed in the patients' WOMAC score and in the overall KOOS score. Serum marker levels were initially elevated in our experimental patient group compared to the same marker in healthy control respondents, and continued to rise one month and three months following surgery, at six and 12 month the level was similar as at three months.

CONCLUSIONS

In our opinion, first COMP increasing can be caused by injection of platelet rich plasma. It is not adequate to interpret this growth in COMP levels as increased osteochondral degeneration. One year follow-up period showed good quality of life improvement, significant pain reduction, and essential MRI changes. The long-term observation of these cohort of patients combined with an analysis of MRI images is still ongoing.

High-energy focused extracorporeal shock wave therapy for bone marrow edema syndrome of the hip: A retrospective study

The objective of this retrospective study was to evaluate the efficacy of high-energy focused extracorporeal shock wave therapy (HF-ESWT) on painful bone marrow edema syndrome (BMES) of the hip and shorten the natural course of disease.Thirty-four consecutive patients with BMES of the hip were treated with HF-ESWT in our department between August 2017and July 2018. The progression and treatment results of BMES were evaluated by imaging examination and clinical outcomes. The clinical outcomes include hip pain and function which were measured using the visual analog scale (VAS) and Harris hip score (HHS), respectively, and the VAS and HHS of all patients were calculated and evaluated before treatment (s0), at 1 month (s1), 3 months (s2), 6 months (s3)post-treatment. Imaging examination including Pelvic radiographs and frog views and double hip magnetic resonance imaging (MRI) were also obtained and scheduled before treatment, at 1, 3, 6, and the final follow-up post-treatment to exclude avascular necrosis and other pathology.All patients successfully completed the treatment and follow-up. Compared with pretherapy, the pain was alleviated to varying degrees and the HHS was significantly improved, and the VAS was significantly reduced at S1-2 (1- and 3-months post-treatment) after therapeutic intervention (P < .05). The mean improvements were strongly statistically significant between S0 and S1 and between S1 andS2 (P < .0001) and less significant between S2 and S3 (P < .01). The mean improvement between 6 months (S3) and final follow-up (more than 12 months) was not statistically significant. The MRI findings demonstrated that the diffuse BMES in the femoral head and neck disappeared completely.HF-ESWT is a safe, effective, reliable, and noninvasive treatment in patients with painful BMES of the hip, and it can accelerate the recovery of BMES of the hip, shorten the treatment time and course of disease, improve hip joint function and the quality of life of patients.

Tissue Engineering and Cell-Based Therapies for Fractures and Bone Defects

Bone fractures and segmental bone defects are a significant source of patient morbidity and place a staggering economic burden on the healthcare system. The annual cost of treating bone defects in the US has been estimated to be $5 billion, while enormous costs are spent on bone grafts for bone injuries, tumors, and other pathologies associated with defective fracture healing. Autologous bone grafts represent the gold standard for the treatment of bone defects. However, they are associated with variable clinical outcomes, postsurgical morbidity, especially at the donor site, and increased surgical costs. In an effort to circumvent these limitations, tissue engineering and cell-based therapies have been proposed as alternatives to induce and promote bone repair. This review focuses on the recent advances in bone tissue engineering (BTE), specifically looking at its role in treating delayed fracture healing (non-unions) and the resulting segmental bone defects. Herein we discuss: (1) the processes of endochondral and intramembranous bone formation; (2) the role of stem cells, looking specifically at mesenchymal (MSC), embryonic (ESC), and induced pluripotent (iPSC) stem cells as viable building blocks to engineer bone implants; (3) the biomaterials used to direct tissue growth, with a focus on ceramic, biodegradable polymers, and composite materials; (4) the growth factors and molecular signals used to induce differentiation of stem cells into the osteoblastic lineage, which ultimately leads to active bone formation; and (5) the mechanical stimulation protocols used to maintain the integrity of the bone repair and their role in successful cell engraftment. Finally, a couple clinical scenarios are presented (non-unions and avascular necrosis—AVN), to illustrate how novel cell-based therapy approaches can be used. A thorough understanding of tissue engineering and cell-based therapies may allow for better incorporation of these potential therapeutic approaches in bone defects allowing for proper bone repair and regeneration.

Free Vascularized Fibular Grafting Improves Vascularity Compared With Core Decompression in Femoral Head Osteonecrosis: A Randomized Clinical Trial

BACKGROUND

Management of osteonecrosis of the femoral head remains challenging. Core decompression and free vascularized fibular grafting are commonly used surgical procedures for treatment of osteonecrosis of the femoral head. Few studies, however, have compared these two procedures in a randomized controlled study, in terms of improved vascularity of the femoral head, progression of disease, or hip scores. QUESTION/PURPOSES: (1) What is the effect of core decompression and fibular grafting on vascularity of the femoral head as measured by single-photon emission CT (SPECT)/CT? (2) Does one of these two methods lead to greater progression of Association Research Circulation Osseous (ARCO) stage as determined by serial MRI? (3) What is the relationship between the change in vascularity of the femoral head and hip function as measured by the Harris hip score (HHS) and progression to THA as an endpoint?

METHODS

A randomized controlled trial was performed between June 2010 and October 2012 at Zhongshan Hospital, Fudan University. During the study period, 51 patients who presented with ARCO Stages I to IIIB bilateral osteonecrosis were potentially eligible for inclusion, and 33 patients were identified as meeting the inclusion criteria and offered enrollment and randomization. Six patients declined to participate at the time of randomization, leaving a final sample of 27 participants (54 hips). Bilateral hips of each patient were randomly assigned to surgical options: one side was treated with core decompression and the contralateral side was concurrently treated with fibular grafting. SPECT/CT examinations were performed to quantify radionuclide uptake to evaluate vascularity of the femoral head before treatment and at 6 and 36 months after surgery. With the numbers available, we found no differences between the groups regarding vascularity at baseline (64% ± 8% core decompression-treated hips versus 64% ± 7% in the fibular-grafted hips; 95% CI, -5% to 5%; p = 0.90). MR images of the hips were obtained before surgery and at 6, 12, 24, and 36 months postoperatively and staged based on the ARCO classification. All patients were assessed clinically before treatment and followed up at 6, 12, 18, 24, 30, and 36 months after treatment using the HHS. We considered a difference in the HHS of 10 as the minimal clinically important difference (MCID). Patient progression to THA was defined as the endpoint for followup. Six patients (22%) were lost to followup.

RESULTS

By SPECT/CT analysis, decompression-treated hips had lower vascularity than fibular-grafted hips at 6 months (68 % ± 6% versus 95% ± 5%; mean difference, -27%; 95% CI, -32% to -23%; p < 0.001) and 36 months (57% ± 4% versus 91% ± 3%; mean difference, -34%; 95% CI, -37% to -32%; p < 0.001). MRI analysis showed no differences between decompression-treated hips and fibular-grafted hips regarding ARCO stage at 12 months (p = 0.306) and 24 months (p = 0.06). Progression of ARCO staging was more severe in the decompression group than the fibular grafting group at 36 months (p = 0.027). The mean HHS was lower in the decompression group than in the fibular grafting group throughout the followup period, although these differences were at or below the MCID of 10 points early on. However, by 18 months, the scores favored fibular grafting (72 ± 4 versus 84 ± 4; mean difference, -13; 95% CI, -15 to -7; p < 0.001), a finding that was maintained at 24, 30, and 36 months. We found no differences between decompression-treated hips and fibular-grafted hips regarding progression to THA at 36 months (two of 21; p = 0.893).

CONCLUSIONS

Hips that underwent a vascularized fibular grafting procedure fared better than hips receiving core decompression as measured by improved vascularity and less progression of osteonecrosis as measured by ARCO staging. The mean HHS of the fibular-grafted hips was better than that of the decompression-treated hips during the entire postoperative period, but the differences were modest early on, and for the early postoperative period the differences were unlikely to have been clinically important; by 18 months after surgery, the differences probably were clinically important. The mid-term outcomes associated with vascularized fibular grafting seen in our patients are associated with improvements in femoral head vascularity and the potential for bone revitalization.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Extracorporeal shock wave therapy in the treatment of primary bone marrow edema syndrome of the knee: a prospective randomised controlled study

BACKGROUND

The aim of this prospective study was to evaluate the effectiveness of extracorporeal shock wave therapy (ESWT) in normalizing the symptoms and imaging features of primary bone marrow edema syndrome (BMES) of the knee.

METHODS

This study compared the outcomes of ESWT (Group A) (n = 20) and intravenously applied prostacyclin and bisphosphonate (Group B) (n = 20) in the treatment of BMES of the knee in our department between 2011 and 2013. The Visual Analog Scale for pain (VAS, 100 mm), the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the SF-36 scores and MRI scans as well as plain radiographs were obtained before and after therapy between two groups.

RESULTS

Compared with Group B, we found greater improvement in VAS, the WOMAC Osteoarthritis Index and SF-36 score at 1, 3 and 6 months post-treatment in Group A (P < 0.05). Furthermore, MRI scans showed a higher incidence of distinct reduction and complete regression of bone marrow edema at 6 months in Group A (95 vs. 65 %; P = 0.018). The MRI at 1 year follow-up showed complete regression in all patients in Group A. However, two cases in Group B continued to normalize over the subsequent follow-up period.

CONCLUSIONS

ESWT can produce rapid pain relief and functional improvement. It may be an effective, reliable, and non-invasive technique for rapid treatment of BMES of the knee.

TRIAL REGISTRATION

Research Registry UIN 528, September 03, 2015.

Treatment of bone marrow lesions (bone marrow edema)

Bone marrow lesions (BMLs) or using older terminology 'Bone marrow edema' is characterised by excessive water signals in the marrow space on magnetic resonance imaging or ultrasound; BMLs constitute a central component of a wide variety of inflammatory and non-inflammatory rheumatologic conditions affecting the musculoskeletal system: BMLs are not only considered significant sources of pain but also linked to increased disease activity in many musculoskeletal conditions (for example, osteoarthritis, rheumatoid arthritis). The purpose of this review is to summarise current knowledge about the treatment of BMLs, with an emphasis on the clinical and histological features of this entity in inflammatory and non-inflammatory disease. We also try to pair this hypothesis with the apparent beneficial effects of various treatment regimens, mainly within the group of bone antiresorptive drugs (calcitonin, bisphosphonates) on symptoms associated with BMLs.

Intractable bone marrow edema syndrome of the hip

There is a need for an effective and noninvasive treatment for intractable bone marrow edema syndrome of the hip. Forty-six patients with intractable bone marrow edema syndrome of the hip were retrospectively studied to compare the short-term clinical effects of treatment with high-energy extracorporeal shock wave therapy vs femoral head core decompression. The postoperative visual analog scale score decreased significantly more in the extracorporeal shock wave therapy group compared with the femoral head core decompression group (P<.05). For unilateral lesions, postoperative Harris Hip Scores for all hips in the extracorporeal shock wave therapy group were more significantly improved than Harris Hip Scores for all hips in the femoral head core decompression group (P<.05). Patients who underwent extracorporeal shock wave therapy also resumed daily activities significantly earlier. Average overall operative time was similar in both groups. Symptoms disappeared significantly sooner in the extracorporeal shock wave therapy group in patients with both unilateral (P<.01) and bilateral lesions (P<.05). Hospital costs were significantly lower with extracorporeal shock wave therapy compared with femoral head core decompression. The intraoperative fluoroscopy radiation dose was lower in extracorporeal shock wave therapy than in femoral head core decompression for both unilateral (P<.05) and bilateral lesions (P<.01). On magnetic resonance imaging (MRI), bone marrow edema improved in all patients during the follow-up period. After extracorporeal shock wave therapy, all patients remained pain-free and had normal findings on posttreatment radiographs and MRI scans. Extracorporeal shock wave therapy appears to be a valid, reliable, and noninvasive tool for rapidly resolving intractable bone marrow edema syndrome of the hip, and it has a low complication rate and relatively low cost compared with other conservative and surgical treatment approaches.

Primary bone marrow oedema syndromes

MRI scanning in patients with rheumatological conditions often shows bone marrow oedema, which can be secondary to inflammatory, degenerative, infective or malignant conditions but can also be primary. The latter condition is of uncertain aetiology and it is also uncertain whether it represents a stage in the progression to osteonecrosis in some patients. Patients with primary bone marrow oedema usually have lower limb pain, commonly the hip, knee, ankle or feet. The diagnosis is one of exclusion with the presence of typical MRI findings. Treatment is usually conservative and includes analgesics and staying off the affected limb. The natural history is that of gradual resolution of symptoms over a number of months. Evidence for medical treatment is limited, but open-label studies suggest bisphosphonates may help in the resolution of pain and improve radiological findings. Surgical decompression is usually used as a last resort.

Transient peripartum osteoporosis of the femoral head in first and third pregnancy

The aim of this article was to present transient peripartum femoral head osteoporosis. This very rare condition occurred twice in our patient-a woman in her 30s. The cases described in the literature were mostly unilateral, with bilateral hip involvement noted much less frequently. In our patient, transient osteoporosis occurred in the third trimester of her first pregnancy in the right hip, her second pregnancy was uncomplicated, and in the third trimester of the patient's third pregnancy, osteoporotic changes were noted in the left hip joint. The patient breastfed her first and third babies only 3 wk each. She breastfed her second baby for 4 mo. The diagnostic workup was based on the clinical examination and radiographic/magnetic resonance imaging, which revealed bone marrow edema, and the dual-energy X-ray absorptiometry scans. The treatment consisted in core decompression of the femoral head (foragé), unloading of the hip using crutches as well as administration of calcitonin and calcium supplements. Complete recovery of the femoral heads was achieved. The follow-up time was 7 yr.

Bone marrow edema syndrome in postpartal women: treatment with iloprost

Bone marrow edema syndrome of the femoral head in pregnant women is a rare disease resulting in disabling coxalgia, beginning in the last 3 months of pregnancy and persisting for several months after parturition. The parenteral administration of the vasoactive drug iloprost constitutes a new approach to the treatment of painful bone marrow edema syndrome of the hip of pregnant women. Six postpartal women (8 hips) with bone marrow edema syndrome of the femoral head were treated with iloprost followed by 3 weeks of partial weight-bearing. Relief from pain, restoration of functional capacity, and normalization of the MRI signal pattern were rapidly achieved, thus avoiding the need for surgical intervention. As the substance is contraindicated in pregnancy, therapy may begin only some days after parturition, with a short discontinuation in breastfeeding.

Persistent anterior hip pain in young adults: current aspects of diagnosis

Persistent anterior hip pain, in young adults, presents a diagnostic and treatment challenge to hip surgeons. Diagnosis, in some cases, is difficult because available diagnostic tools are not very reliable, resulting in a difficult decision making process. This article discusses the possible causes, current knowledge of the condition and outlines a method to approach this difficult problem.

Outcome of painful bone marrow edema of the femoral head following treatment with parenteral iloprost

BACKGROUND

Bone marrow edema (BME) is a common cause of hip pain. The aim of the study was to assess the efficacy of the vasoactive drug iloprost in the treatment of BME of femoral head.

MATERIALS AND METHODS

We reviewed 27 patients (19 male, 8 female) with BME of the femoral head. Their mean age was 53.7 +/- 10.8 years. All patients were treated with iloprost, a vasoactive drug that dilates arterioles and venules, reduces capillary permeability and suppresses platelet aggregation. The therapy comprised a series of five infusions with 20 to 50 mug iloprost over 6 h on 5 consecutive days each. Weight bearing was reduced for up to 3 weeks, depending on the severity of symptoms. Pain at rest as well as under stress was assessed with a semi quantitative scale from before and 4 months after therapy. MRI investigations were done before and repeated 4 months after therapy.

RESULTS

At the clinical follow up of four months after therapy, the pain level at rest had diminished by a mean of 58.3% (P < 0.0001). Pain under stress decreased by a mean of 41.9% (P < 0.0001). On MRI, 20 patients had a significant reduction of BME size or complete normalization and 4 showed no change. Worsening of the MRI pattern was found in 3 patients.

CONCLUSION

The authors conclude that the use of parenteral iloprost might be a viable method in the treatment of BME of femoral head.

Rationale for prostaglandin I2 in bone marrow oedema--from theory to application

Introduction

Bone marrow oedema (BME) and avascular osteonecrosis (AVN) are disorders of unclear origin. Although there are numerous operative and non-operative treatments for AVN, pain management in patients with AVN remains challenging. Prostaglandins play an important role in inflammatory responses and cell differentiation. It is thought that prostaglandin I₂ ([PGI₂] or synonoma prostacyclin) and its analogues promote bone regeneration on a cellular or systemic level. The purpose of this study was to assess the curative and symptomatic efficacy of the prostacyclin analogue iloprost in BME and AVN patients.

Method

We are reporting on 50 patients (117 bones) affected by BME/AVN who were treated with iloprost. Pain levels before, during and 3 and 6 months after iloprost application were evaluated by a visual analogue scale (VAS). The short form(SF)-36 health survey served to judge general health status before and after treatment. Harris Hip Score (HHS) and Knee Society Score (KSS) were performed as functional scores and MRI and X-rays before and 3 and 6 months after iloprost application served as objective parameters for morphological changes of the affected bones.

Results

We found a significant improvement in pain, functional and radiological outcome in BME and early AVN stages after iloprost application, whereas patients with advanced AVN stages did not benefit from iloprost infusions. Mean pain level decreased from 5.26 (day 0) to 1.63 (6 months) and both HHS and KSS increased during follow-up. Moreover, the SF-36 increased from 353.2 (day 0) to 560.5 points (6 months). We found a significant decrease in BME on MRI scans after iloprost application.

Conclusions

In addition to other drugs, iloprost may be an alternative substance which should be considered in the treatment of BME/AVN-associated pain.

Transient osteoporosis of the knee

A 52-year-old man presented with a 3-week history of right knee pain, significant enough to prevent weight bearing. There was no history of knee injury or disease. On knee examination, an effusion and medial joint line tenderness was noted. Knee range of motion was full, but painful. Radiographs revealed minor osteoarthritic changes. Laboratory values were within normal limits, including those associated with infection. Magnetic resonance imaging showed decreased signal intensity on T1-weighted images within the medial femoral condyle and corresponding increased signal intensity on T2-weighted consistent with bone marrow edema as well as edema to the adjacent soft tissues. Bone scanning showed increased uptake of radioisotope in the medial femoral condyle. The patient was diagnosed with bone marrow edema syndrome, and managed medically with analgesics and continued non weight-bearing status. At the 1-month follow-up, his symptoms had improved significantly. The patient progressively increased weight bearing as tolerated over the subsequent weeks. At 12-week follow-up, symptoms had completely resolved. Magnetic resonance imaging showed no signal abnormalities in the affected knee. Transient osteoporosis is an uncommon and typically self-limiting condition that can be challenging to diagnose and treat. The clinician must be aware of this entity, as well as its typical course, to prevent unnecessary testing and invasive intervention.

Regional migratory osteoporosis

Regional migratory osteoporosis (RMO) is an uncommon disease characterised by a migrating arthralgia involving the weight bearing joints of the lower limb. The typical imaging findings on radiographs, magnetic resonance imaging, computed tomography and bone scintigraphy are described and illustrated. Men in their fifth and sixth decades of life are most commonly affected. The most common presentation is with proximal to distal spread in the lower limb. The world literature has been reviewed which has revealed 63 documented cases of regional osteoporosis or bone marrow oedema with migratory symptoms. Most of these cases have not been labelled as RMO and therefore the condition is probably under-diagnosed. The radiology of RMO is indistinguishable from transient osteoporosis of the hip (TOH) except for the migratory symptoms and the two conditions are likely to be part of the same spectrum of disease. Systemic osteoporosis is a more recently recognised accompanying feature that hints at an underlying aetiology and an approach to the management of this condition.

Subchondral fracture of the femoral head in healthy adults

Subchondral fracture of the femoral head has been reported to occur as an insufficiency fracture associated with poor bone quality or as a fatigue fracture in young military recruits. Transient osteoporosis of the hip has clinical and imaging findings that resemble those of a subchondral fracture, but it usually occurs in healthy middle-aged people not involved in sports or similar activities. The clinical aspects of five cases of subchondral fracture of the femoral head occurring in four healthy adults without antecedent trauma were evaluated. Of particular interest were whether subchondral fracture of the femoral head could occur without a sudden increase in daily activity and what differences could be detected from the imaging and clinical courses between subchondral fracture of the femoral head and transient osteoporosis of the hip. Three cases of subchondral fracture of the femoral head occurred without an increase in daily activity. The only difference in imaging findings between subchondral fracture of the femoral head and transient osteoporosis of the hip was the existence of a subchondral fracture line seen on magnetic resonance images of a subchondral fracture of the femoral head. The clinical courses of these disorders were similar. These findings suggest transient osteoporosis of the hip and subchondral fracture of the femoral head are subchondral bone injuries of different severity.

LEVEL OF EVIDENCE

Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Transiente Osteoporose und aseptische Femurkopfnekrose

Osteonecrosis of the femoral head usually affects patients in their third to fifth decade of life. Common risk factors are alcohol, nicotine, corticosteroids, hyperlipidaemia and hypercoagulability. Depending on the stage of the osteonecrosis, the diagnosis is confirmed by radiographs, magnetic resonance imaging or scintigraphy. The ARCO classification (Association Research Circulation Osseous), which is based on older classifications recommended by Ficat/Arlet, Steinberg, Koo or Marcus/Enneking, is a valuable prognostic tool for finding an adequate treatment option. Transient osteoporosis of the hip is controversially discussed as a pre-stage of osteonecrosis or a self-limiting condition based on reflex dystrophy. Conservative and operative treatment options are reported in the literature. Recently published data favour core decompression as an effective procedure for early stage osteonecrosis and transient osteoporosis.

Bildgebung der aseptischen Femurkopfnekrose des Erwachsenen

The aim of diagnostic imaging procedures in avascular femoral head necrosis is to provide the patient with a stage-adapted therapy. Therefore, a differentiated diagnostic work-up is needed. Native radiography of the hip in two planes is still the first step. Over the past years, the diagnosis of femoral head necrosis has experienced tremendous improvement due to the use of MRI and CT scans. Because of these improvements the correct stage can be diagnosed early and the appropriate therapy can be initiated immediately. Today, MRI is the most sensitive diagnostic imaging procedure. CT scans can be particularly useful to exclude subchondral fractures. The use of bone scintigraphy is restricted to exceptional cases. In Europe, the ARCO classification of avascular femoral head necrosis has been widely accepted. It is essential here to define subtypes according to the localisation and the extent of the necrosis, because both have major influence on the prognosis of the disease and therefore also for the therapeutic strategy. In this overview, we describe the specific characteristics of the different diagnostic imaging procedures and illustrate them with appropriate imaging material. At the end of the article an algorithm for diagnostic imaging procedures in avascular femoral head necrosis for daily orthopaedic practice is proposed.

MR Imaging of the Hip: Osseous Lesions

Because of the exquisite soft tissue contrast resolution of MR imaging combined with recent technologic developments, a variety of conditions involving the hip joint and adjacent bony structures can be well evaluated using MR imaging, with or without contrast material. Among the different conditions, hip trauma and avascular necrosis are the most frequent indications. Other entities for which MR imaging has proven its usefulness include subchondral fractures, osteochondritis dissecans, transient osteoporosis, bone tumors, inflammatory and infectious processes, and a variety of bone marrow disorders.