Intralesional Ethibloc injections in primary aneurysmal bone cysts: an efficient and safe treatment

[Aneurysmal bone cyst of the ulna]

Aneurysmal bone cyst (ABC) accounts for 1 to 4 percent of primary bone tumours. There is a distinct predominance in the 10- to 20-year age group, and it is rare after age 50. Despite its benign character, it is sometimes locally aggressive, and can attain significant size. This was so in the case we report of a patient with an ABC of the ulna.

[Aneurysmal carpal scaphoid cyst. A case report]

Aneurysmal bone cyst is a rare, benign bone tumor and its location in the carpal scaphoid has never been described in the literature. We report a clinical case illustrating this location.

Percutaneous intralesional injection of calcitonin and methylprednisolone for treatment of an aneurysmal bone cyst at C-2

An aneurysmal bone cyst (ABC) is a rare skeletal tumor that accounts for approximately 1% of all bone tumors. A spinal location for an ABC is very rare. Methods for treatment of an ABC include resection, curettage, embolization, and intralesional injection of a variety of agents. The patient in this case was a 9-year-old girl presenting with neck pain who was diagnosed with an ABC involving the C-2 spinal level. Percutaneous intralesional injections of calcitonin and methylprednisolone were performed. Two years and 7 months after the initial injection, a CT scan showed massive bone formation and cortical thickening without a change in the size of the lesion. To the authors' knowledge, this is the third reported case of intralesional injection of calcitonin and methylprednisolone for treatment of an ABC. This method is safe and effective, and is an important alternative to surgery, especially when a surgical procedure is technically difficult or unsafe in high-risk patients.

Aneurysmal bone cyst recurrence in children: a review of 56 patients

BACKGROUND

Aneurysmal bone cysts (ABCs) are benign lesions that are usually treated with intralesional procedures. The clinical behavior of ABCs is reported to be more aggressive in younger patients, with high recurrence rates after surgical treatment by several authors. The purpose of this study was to review longitudinally the demographic data and outcome of current surgical techniques in children with ABC treated at a single institution and to determine the possible risk factors for recurrence, which may be detected at initial examination, including age, presenting complaint, and radiological characteristics.

METHODS

The authors performed a retrospective, pediatric population-based (< or =16 years) analysis of 56 cases of ABCs with more than 2 years' follow-up. The subjects were studied and classified on the basis of their age group (< or =5, 5-10, and >10 years of age). The possible risk factors for recurrence were analyzed initially with Student t test and Pearson chi2 test, then a logistic regression analysis model was used for multivariate analysis.

RESULTS

Nine patients were younger than 5 years, 17 were between 5 and 10 years old, and 30 were older than 10 years. The most frequent location of the lesion was the humerus (11 cases) followed by proximal femur and fibula. Curettage was the most common treatment modality followed by resection. Recurrence of the lesion occurred in 5 children in the younger age group and in 4 children in the older age group. The difference in persistence or recurrence rates based on age (< or =5 years) and previous surgery was statistically significant. In addition, we have found no significant implication of physeal contact and size of the lesion on recurrence.

CONCLUSIONS

The recurrence rates of primary ABC seemed to be higher in younger children. Considering the high cure rates with intralesional procedures even after recurrence, we suggest less aggressive intralesional procedures even in patients with mentioned risk factors; however, the patients' family should be informed about the high probability of recurrence.

Modern concepts of primary aneurysmal bone cyst

INTRODUCTION

Despite the long experience of radiologists, pathologists and orthopaedists with aneurysmal bone cysts (ABC), there is limited knowledge regarding the cause of the lesion and the optimal treatment. The pathogenesis of ABC remains unclear with theories ranging from a post-traumatic, reactive vascular malformation to genetically predisposed bone tumours. Recent genetic and immunohistochemical studies proposed that primary ABC is a tumour and not a reactive tumour-simulating lesion. The chromosomal analyses and some reported familial cases of this osteolytic bone lesion propose a hereditary factor in a presumably multifactorial pathogenesis.

MATERIALS AND METHODS

The imaging studies, even CT scan and MRI sometimes do not provide clearly diagnostic criteria for the diagnosis of ABC. The radiographically differential diagnosis between ABC and unicameral bone cyst (UBC) is sometimes not clear. Double density fluid level, septation, low signal on T1 images and high intensity on T2 images strongly suggest the bone cyst is an ABC, rather than a UBC.

CONCLUSION

Common methods of treatment vary considerably in the literature. The usual methods of treatment are curettage, resection, intracystic injections and embolization. Biopsy is imperative before any treatment. Ethibloc treatment remains highly controversial. For some authors Ethibloc injection can be recommended as the first-choice treatment excluding spinal lesions. A minimally invasive method by introduction of demineralized bone and autogenous bone marrow is able to promote the self-healing of a primary ABC.

Le kyste osseux anévrismal primitif : quoi de neuf en 2006 ?

The etiology of aneurysmal bone cyst is probably multifactorial. Recent progress in genetics and immunohistochemistry tends to prove that aneurysmal bone cyst is tumor and not a pseudo-tumor. Involvement of chromosomes 17p11-13 or 16q22 has been described. MRI is indispensable. Signs highly suggestive of aneurysmal bone cyst are: well-limited expansive bone lesion, low intensity T1 signal associated with high intensity T2 signal (liquid component), a low intensity peripheral line with enhancement after contrast injection, septal partitioning and fluid levels. Gadolinium injection is informative since it demonstrates the thick regular septal partitioning and the amorphous contents (lack of contrast uptake), a structure which is not seen in any other tumors, particularly malignant tumors. Plain x-ray and MRI contribute well to diagnosis but histological confirmation is always required. The debate on Ethibloc(R) remains open. For certain authors, this technique is an effective safe treatment which can be proposed as a first-line option. Ethibloc(R) should however be reserved for specialized teams because of the serious complications reported in the literature. A new treatment has also been reported to be promising, but further results will be required for confirmation. With this technique demineralized allogenic bone particles associated with autologous bone marrow are implanted in the cyst to achieve an osteogenic effect. This induces the cyst to pass from the destructive resorption phase to the repairing osteogenic phase. Curettage is not necessary. This method, which avoids extensive surgery and blood loss, is well adapted to difficult localizations such as the pelvis.

The dangers of intraosseous fibrosing agent injection in the treatment of bone cysts. The origin of major complications shown in a rabbit model

Direct intraosseous injection of fibrosing agent is widely used in the treatment of aneurysmal bone cysts. The purpose of this study was to evaluate the consequences of fibrosing agent penetrating the medulla of bones. This may be the case when, by mistake, the fibrosing agent is administered into the medulla or when the wall of the cyst ruptures and fibrosing agent is able to drift into the medulla. Twelve rabbits were injected transcutaneously with a fibrosing agent directly into the proximal metaphysis of the tibia. Prior to injection 0.5 ml of liquid-like, bloody, intraosseal tissue was aspirated, then 0.5 ml of fibrosing agent was administered. Fibrosing agent was introduced slowly (20 s) to avoid overpressure. Nine rabbits (75%) died within minutes after the introduction of fibrosing agent. A full body roentgenogram was taken of each rabbit and the animals that died underwent autopsy to find the exact cause of death. Roentgenograms of the chest showed massive multiple pulmonary emboli confirmed in all lethal cases by the autopsy. This animal model was created to draw attention to the dangers of any leakage of the fibrosing agent into the medulla of bones.

Current treatments of primary aneurysmal bone cysts

The management of aneurysmal bone cyst depends on the age of the patient, the location, extent, aggressiveness and the size of the lesion. In the light of their experience and a review of the literature of 1256 aneurysmal bone cysts, the authors analyzed various treatment modalities. Inactive lesions can heal with biopsy or curettage alone. In active or aggressive lesions, elective treatment usually consists of curettage, whether associated or not with bone grafting and local adjuvants. Aneurysmal bone cyst in young children do not seem more aggressive than in older children. In pelvic locations, the emergence of a few cases of spontaneous healing (even in active or aggressive lesions) encourages the adoption of clinical and radiological supervision for some months after biopsy when possible. In some cases, the localization and extent of the cyst are such that operative treatment is extremely hazardous. Selective arterial embolization has made a considerable contribution towards the therapeutic solution of such cases. For some authors, direct percutaneous Ethibloc injection can be recommended as the first-choice treatment except in spinal lesions. Nevertheless, the complications encountered in some series after percutaneous embolization of aneurysmal bone cyst with Ethibloc should encourage the use of Ethibloc injection not as an initial treatment but as a reliable alternative to surgery.

Aneurysmal bone cysts of the pelvis in children: a multicenter study and literature review

The authors analyzed a series of 15 pelvic aneurysmal bone cysts (9 boys and 6 girls) in children and adolescents who were reviewed with an average follow-up of 50.3 months. Pain and limp were the main symptoms. Four patients had no treatment after the open biopsy. Eleven patients were treated with curettage. Preoperative selective arterial embolization was performed in three cases before curettage. Two recurrences were noted after curettage; recurrences were treated successfully with further curettage. As a result, the authors recommend curettage; more aggressive operative intervention does not appear to be indicated. No major intraoperative vascular complications occurred. Spontaneous healing in a few cases (even in active or aggressive lesions) argues for clinical and radiologic observation after biopsy when possible. In case of a propitious evolution, observation must be continued and surgery might be avoided, but if the lesion increases, treatment must be proposed.

[Aggressive aneurysmal bone cyst of the humerus in a child]

A 9-year-old child presented an aggressive aneurysmal bone cyst of the humerus. Despite multiple treatments (intracystic steroid injections, curettage, Ethibloc injection), the lesion continued to progress. Surgical treatment was undertaken at the age of 19 years and enabled total tumor resection associated with reconstruction with a vascularized fibular flap. Five years later, the patient was free of recurrence. The graft was well integrated and shoulder function was normal. We present the diagnostic difficulties encountered in this case and discuss the therapeutic options. Biopsy is indispensable before instituting treatment.

Percutaneous Ethibloc injection in the treatment of primary aneurysmal bone cysts

The effects of percutaneous Ethibloc (Ethicon/Johnson & Johnson, St-Stevens-Woluwe, Belgium) injection into primary aneurysmal bone cysts were analysed. Two patients with a venous drainage after injection of a medium contrast were excluded. Twelve patients underwent at least one percutaneous injection of Ethibloc. The average follow-up period was 5.1 years. At final follow-up, six patients had complete healing of the cyst, three had partial healing and three, who had no response, were treated by curettage and bone grafting. Complete healing was observed for all the aggressive lesions. No major complications were noted. Ethibloc injection may be performed as a primary treatment of aneurysmal bone cysts if the technique is followed with precision.

Imaging of Patellar Cartilage with a 2D Multiple-Echo Data Image Combination Sequence

OBJECTIVE

We sought to evaluate the diagnostic value of a 2D multiple-echo data image combination (MEDIC) MRI sequence in the detection of patellar cartilage defects.

MATERIALS AND METHODS

Our study included 52 consecutive patients who had knee surgery within 4 months of undergoing an MRI examination including an axial 2D MEDIC (TR/TE, 884/26; flip angle, 30 degrees ) sequence. Cartilage was surgically graded on a 5-point scale: 0, normal; 1, softening or swelling; 2, partial thickness defect; 3, fissuring to the level of the subchondral bone; or 4, exposed subchondral bone. Cartilage was graded on MRI according to a scale that was almost identical to the surgical scale except that grade 1 lesions were defined as signal alteration or swelling of cartilage. Two blinded reviewers independently analyzed patellar cartilage. Sensitivity, specificity, accuracy, and weighted kappa values for interobserver variability were calculated.

RESULTS

Low-grade cartilage lesions predominated in our study group. When grade 2 or higher was considered the threshold for relevance, the sensitivity, specificity, and accuracy for the MEDIC sequence was as high as 79%, 82%, and 81%, respectively. Increasing the threshold of relevance to grade 3 increased the sensitivity, specificity, and accuracy to as high as 83%, 91%, and 90%, respectively. Interobserver agreement for the MEDIC sequence was good (weighted kappa = 0.68).

CONCLUSION

The 2D MEDIC sequence performs comparably to previously described sequences optimized for cartilage imaging such as the 3D double-echo steady-state or 3D spoiled gradient-recalled sequences with good interobserver agreement, high sensitivity, and excellent specificity for revealing low- to intermediate-degree cartilage defects.

Reconstruction d'une phalange totale par greffe chondrale libre non vascularisée après échec de sclérothérapie d'un kyste anévrysmal

We treated an eleven year-old boy for an aneurysmal bone cyst of the middle phalanx of the long finger. Diagnosis was established after total curettage. The tumor involved the whole phalanx and grew steadily after two attempts at sclerotherapy (with absolute alcohol and Ethibloc). After two years, en-bloc resection had to be performed, and raised the problem of reconstructing a complete finger phalanx with its proximal and distal epiphyses. A free cartilaginous graft from the non-ossified iliac crest was shaped to the exact dimensions of the phalanx and set in its place, with minimal damage to the surrounding tissues during dissection and fixation. By six months an almost normal range of motion was achieved in the PIP (10 to 90 degrees ) and DIP (5 to 30 degrees) joints and radiographs showed complete metaplasia of the chondral graft into an ossified phalanx at 20 months follow-up. The joint spaces also remodelled, and this was confirmed with MRI scanning. Reports on partial replacement of diaphysis or epiphyses in the digits are discussed, but the only valid comparison of total phalanx replacement is free toe phalanx grafting. We did not choose this solution in a normal hand because of the length discrepancy between finger and toe phalanges. This case shows that, in this particular paediatric situation, the free non-vascularised transfer of a chondral graft restored excellent function, with remodelling of the phalanx and joint spaces of the finger.

Recurrence of aneurysmal bone cysts in young children: a multicentre study

Some authors have reported that the clinical and pathologic behaviour of aneurysmal bone cysts (ABCs) is more aggressive in younger patients and that younger patients have more tumour recurrence. The authors carried out a retrospective, multicentred paediatric population-based analysis of 21 patients (14 boys and seven girls), 5 years of age or younger, with primary ABCs. Only patients with a minimum follow-up of 2 years were included. The most common operation was curettage (14 cases). Methylprednisolone acetate injection was used in two cases (failure in the initial diagnosis before biopsy) with negative results. An Ethibloc (Ethnor Laboratories/Ethicon, Norderstedt, Germany) injection was employed in four cases. There were five recurrences. Three lesions recurred once, one lesion recurred three times and one recurred six times. These recurrences occurred in two cases after methylprednisolone acetate injection, after Ethibloc (Ethnor Laboratories/Ethicon) injection (one case) and, after curettage (two cases). ABCs in children, 5 years of age or younger, do not seem to be more aggressive than in older children. Curettage is a surgical procedure that can be used even in young children. Of course, recurrence is always possible but the recurrence rate is not unacceptable. More aggressive operative intervention does not appear to be indicated.

MR arthrography of the hip: diagnostic performance of a dedicated water-excitation 3D double-echo steady-state sequence to detect cartilage lesions

OBJECTIVE

The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine.

MATERIALS AND METHODS

In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined).

RESULTS

At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55).

CONCLUSION

The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.