Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. We previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine. Fourteen patients (6 male, 8 female) were treated between June 2014 and December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12–60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, data suggest that BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

Introduction. Aneurysmal bone cysts commonly found in lower limbs are locally aggressive masses that can lead to bony erosion, instability and fractures. This has major implications in the lower limbs especially in paediatric patients, with potential growth disturbance and deformity. In this case series we describe radical aneurysmal bone cyst resection and lower limb reconstruction using cable transport and syndesmosis preservation. Materials & Methods. Case 1 - A 12-year-old boy presented with a two-week history of atraumatic right ankle pain. An X-ray demonstrated a distal tibia metaphyseal cyst confirmed on biopsy as an aneurysmal bone cyst. The cyst expanded on interval X-rays from 5.5cm to 8.5cm in 9 weeks. A wide-margin en-bloc resection was performed leaving a 13.8cm tibial defect. A cable transport hexapod frame and a proximal tibial osteotomy was performed, with syndesmosis screw fixation. The transport phase lasted 11 months. While in frame, the boy sustained a distal femur fracture from a fall. The femur and the docking site were plated at the same sitting and frame removed. At one-year post-frame removal he is pain-free, with full ankle dorsiflexion but plantarflexion limited to 25 degrees. He has begun graduated return to sport. Results. Case 2 - A 12-year-old girl was referred with a three-month history of lateral left ankle swelling. X-ray demonstrated an aneurysmal bone cyst in the distal fibula metaphysis. The cyst grew from 4.2 × 2.3cm to 5.2 × 3.32cm in 2 months. A distal fibula resection (6.2cm) with syndesmosis fixation and hexapod cable transport frame were undertaken. The frame was in situ for 13 weeks and during this time she required an additional osteotomy for premature consolidation and had one pin site infection. After 13 weeks a second syndesmosis screw was placed, frame removed, and a cast applied. 3 months later she had fibular plating, BMAC and autologous iliac crest bone graft for slow union. At 3 years post-operative she has no evidence of recurrence, is pain-free and has no functional limitation. Conclusions. We describe two cases of ankle syndesmosis preservation using cable transport for juxta-articular aneurysmal bone cysts. This allows wide resection to prevent recurrence while also preserving primary ankle stability and leg length in children. Both children had a minor complication, but both had an excellent final outcome. Cable bone transport and prophylactic syndesmosis stabilization allows treatment of challenging juxta-articular aneurysmal bone cysts about the ankle. These techniques are especially useful in large bone defects

Introduction and Objective. Aneurysmal bone cyst (ABC) of the spine is a locally aggressive benign lesion which can be treated by en bloc resection with wide margin to reduce the risk of local recurrence. To avoid morbidity associated with surgery, selective arterial embolization (SAE) can be considered the first-line treatment for ABCs of the spine. Other emerging treatments for ABCs include bisphosphonates, percutaneous doxycycline, sclerotherapy and Denosumab. In addition, we previously introduced the use of autologous bone marrow concentrate (BMC) injection therapy to stimulate bone healing and regeneration in ABC of the spine. One of the potential advantages of such a method is that surgical treatments are not necessary, thus allowing for both a minimally invasive approach and the treatment of poorly accessible lesions. In this prospective study we described the clinical and radiological outcomes of percutaneous injection of autologous BMC in a series of patients affected by ABCs of the spine and followed for at least one year. Materials and Methods. Fourteen patients (6 male, 8 female) were treated between June 2014 to December 2019 with BMC injection for ABC of the spine. The mean age was 17.85 years. The mean follow up was 37.4 months (range 12– 60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits. Results. Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48±2.36 HU to 161.71±23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up. We also observed that five out of six female patients (83.3%) were less than sixteen years old and four of these (66.7%) were managed with a single dose of BMC injection, while a higher percentage of male patients (6/8, 75%) were more than sixteen years old and more than one injection was administered to them. Conclusions. The results of this study reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE is contraindicated or ineffective. The initial size of the cyst and its localization does not influence the efficacy of the treatment. However, BMC injection could be indicated as treatment of choice for spinal ABC in young adolescent women

Introduction. Periprosthetic cyst formation following ankle replacement, requiring revision surgery, has previously been reported. The exact pathogenesis of cyst formation is unclear but considered to be due to a combination of biological and mechanical factors. Our objective was to review the incidence of periprosthetic cyst formation following Mobility ankle replacement and their outcome. Patients and methods. We reviewed all the Mobility ankle replacements performed by the senior author from Oct 2005 till May 2012. Serial radiographs were reviewed to identify the presence of cystic lesions in the tibia or the talus. Results. 124 Mobility ankle replacements were performed in 116 patients during our study period. Average age was 65 years (22 to 88) with male to female ratio of 2:1. Average follow-up was 32 months (7 to 73). Radiographic review of the most recent available radiograph showed cystic changes in the distal tibia in 10 patients (8%). One patient had cystic appearance pre-operatively which was not found to be progressive after replacement. Seven patients were asymptomatic. Three patients presented with ankle pain, which was thought to be due the cyst. One of the symptomatic patients had undergone revision of tibial component and bone grafting of the cyst 32 months after primary surgery. The second patient is awaiting surgery for exploration and possible bone graft (40 months after primary surgery). The 3. rd. patient is awaiting CT scan for further evaluation of the cyst. Conclusion. Our study shows that cystic changes were present in 8% of TAR at medium term review. 70% (7 patients) were asymptomatic and 30% required intervention for being symptomatic. Regular review of the TAR patients is essential to identify the patients who develop cyst formation

Aims. Aneurysmal bone cysts (ABCs) are locally aggressive lesions typically found in the long bones of children and adolescents. A variety of management strategies have been reported to be effective in the treatment of these lesions. The purpose of this review was to assess the effectiveness of current strategies for the management of primary ABCs of the long bones. Methods. A systematic review of the published literature was performed to identify all articles relating to the management of primary ABCs. Studies required a minimum 12-month follow-up and case series reporting on under ten participants were not included. Results. A total of 28 articles meeting the eligibility criteria were included in this review, and all but one were retrospective in design. Due to heterogeneity in study design, treatment, and outcome reporting, data synthesis and group comparison was not possible. The most common treatment option reported on was surgical curettage with or without a form of adjuvant therapy, followed by injection-based therapies. Of the 594 patients treated with curettage across 17 studies, 86 (14.4%) failed to heal or experienced a recurrence. Similar outcomes were reported for 57 (14.70%) of the 387 patients treated with injection therapy across 12 studies. Only one study directly compared curettage with injection therapy (polidocanol), randomizing 94 patients into both treatment groups. This study was at risk of bias and provided low-quality evidence of a lack of difference between the two interventions, reporting success rates of 93.3% and 84.8% for injection and surgical treatment groups, respectively. Conclusion. While both surgery and sclerotherapy are widely implemented for treatment of ABCs, there is currently no good quality evidence to support the use of one option over the other. There is a need for prospective multicentre randomized controlled trials (RCTs) on interventions for the treatment of ABCs. Cite this article: Bone Jt Open 2021;2(2):125–133

Purpose of the study: Cysts are rarely identified in the anterior cruciate ligament; the pathogenic mechanisms involved are poorly understood. We investigated the anatomic and clinical presentation. Material and methods: This retrospective analysis included 24 patients, seven women and seventeen men managed in a single center from 1998 to 2004. Mean patient age was 45 years (range 25–74 years). All patients complained of pain. A preoperative MRI was available for all patients. Mean follow-up was 25 months (range 6–48 months). Arthroscopic procedures were used for 17 patients and the IKDC subjective score was determined preoperatively in all. Radioguided (US or CT) puncture was performed for seven patients associated with corticosteroid injections. Results: On the MRI, there were 16 infiltrating cysts and eight cystic formations. Surgical treatment (n=17) was performed for 13 infiltrative cysts and for four cystic formations. There were two cases of recurrence. Outcome was poor after puncture (two puncture failures, three recurrences and one vascular complication). Discussion: Two forms of cysts of the ACL can be demonstrated by MRI. The clinical presentation may not be different but the therapeutic management should be. The cystic formation is an indication for puncture, with arthroscopic treatment in the event of failure. For infiltrating cysts, complete resection of the cyst during an arthroscopic procedure is indicated, sometimes associated with resection of the ACL. Puncture yields poor results

The purpose of this study is to call attention to the diagnosis of spinal cyst caused by lumbar disc herniation. Reviewing a total of 11 cases of lumbar spinal cyst that have been encountered in our spinal practice, we propose our views concerning the pathology of this lesion. The clinical findings of lumbar spinal cyst are identical to those in acute disc herniation such as low back pain and radiculopathy. The characteristics of imaging study are as follows; The magnetic resonance imaging (MRI) demonstrates a relatively large, rounded mass postero-laterally to the vertebral body. These lesions are isointense relative to the intervertebral disc on T1-weighted images and homogeneously hyperintense on T2. A gadolinium -DTPA-enhanced MRI shows a rim-enhancing lesion. A discogram reveals leakage of the contrast medium into the mass. The operative findings demonstrated encapsulated soft tissue masses which contained bloody fluid and small fragments of herniated disc tissue. The pathologic examinations revealed fibrous tissue with hemosiderin deposit in cyst wall and degenerative disc materials with inflammatory cell infiltration. This type of lumbar spinal cyst has been recognized as spinal epidural hematoma in recent years. Wiltse suggested that epidural hematoma may result from tearing of fragile epidural veins due to acute disc disruption. However, MRI characteristics of hematoma are not identical with those with lumbar spinal cyst. It is more likely that the lesions showing the pattern of changes are herniated disc tissue accompanied by hemorrhage and inflammation. If hernial tissue is covered with some membranous susbtance, formation of cystic lesions is understandable. Hence, we hypothesize that lesions, in which lysis liquefaction and absorption of the herniated disc tissue associated with inflammatory response have progressed, and the herniated disc tissue has completely disappeared, may be filled solely with bloody fluid, showing an appearance like cysts

Purpose: First described in 1699, hydatid cyst in a muscle is extremely rare today, even in endemic areas. Material and methods: We report a retrospective series of nine cases of primary hydatid cyst observed between 1985 and 1998. The patients were predominantly women living in a rural area (mean age 37 years), who consulted for an isolated tumefaction of the thigh (left side in 7/9 cases) which had evolved for twelve months on the average without affecting the general health status. Ultrasonography was highly contributive, suggesting the diagnosis in all cases. Hydatic serology was positive in five cases. Computed tomography (n=3) and magnetic resonance imaging (n=2) provided supplementary information. Hydatid cysts were identified in the adductors (n=4), the quadriceops (n==3) and the three compartments (n=1). Results: Surgical treatment was performed in eight patients; en bloc resection of the hydatid cyst with peripheral muscle tissue in six cases and subtotal pericystectomy in two. Clinical and anatomic results are presented at mean six years follow-up. Discussion: We discuss the role of each radiographic examination for the diagnosis and search for extension of hydatid cysts as well as the therapeutic options depending on the clinical course and soft tissue involvement

Background:. Lumbar intraspinal cysts (LICs) are rare incidental MRI findings in back pain. Their space-occupying nature make them plausible factors in both non-specific and radicular back pain. Methods:. Retrospective cohort study of patients with MRI reports of LICs at our center over 5 years. N=26, 13 male, mean age 66 ± 12 years. Results:. LICs originated at levels from L1-S2 (61.5% at L4/5), reaching 17mm. 2. (rapid one year progression in this case). LICs were described as synovial in all but two cases (hemorrhagic cyst; Tarlov perineural cysts). Background degenerative changes were reported in 88.5% of cases. Patients described up to 30-year histories of non-specific back pain. Clinical features of radiculopathy plus concomitant MRI findings were indications for surgical decompression (n=14) and cyst excision (n=13/14). 2 cases of spontaneous LIC resolution, and 2 cases of post-operative complications were identified (inflammatory/scar tissue stenosis). 0% cyst recurrence rate with sustained resolution of symptoms currently stands. Conclusions:. Frequent co-existence of LICs with degeneration implicates the former as a product of osteoarthritic processes, conceivably contributing to patient accounts of chronic non-specific pain. LICs may equally constitute acute direct causes of radiculopathy, owing to their diverse origins and potential to rapidly expand. A role of LICs in axial and radicular pain, independent of other degenerative changes, is supported by symptom alleviation in cases of spontaneous resolution, versus progression with decompression performed without cyst excision (Tarlov cyst), or following novel cyst formation at the level of previous spinal fusion. Whether image-guided aspiration might reduce surgery-related side-effects is a topic for further work

Purpose: Radiologists describe cysts of the anterior cruciate ligament (ACL) as a cystic formation of the cruciate tentorium. The estimated prevalence is 0.2 to 1.3% of patients explored by magnetic resonance imaging. The purpose of this study was to better define the clinical symptoms involved by comparing clinical, radiological and pathological findings. Material and methods: Between February 1996 and April 2000, nine men underwent surgery of the anterior cruciate ligament for cysts. Mean age at surgery was 43 years (26) 54). None of the patients had a history of trauma and one patient had undergone medial meniscectomy 12 months earlier due to meniscosis. Pain had been present for six months to seven years and progressed slowly. It was very specifically related to hyperflexion. Five patients exhibited a moderate effusion and five had a painful joint line. The Lachmann was stiff. Single leg stance plain x-rays were normal. Magnetic resonance imaging demonstrated a poorly delimited heterogeneous destructured aspect of the ACL in seven patients. The suggested diagnosis was “partial tear of the ACL or old tear of the ACL”. A perfectly circumscribed cyst was revealed by the MRI in two cases, lying behind the ACL in the tentorium of the notch. The posterior cruciate ligament had a normal aspect in all cases. Results: All patients underwent arthroscopy. The ACL was deorganised, widened and yellow in eight, with a yellow circumscribed nodule on the posterior aspect in one. An impingement between the ACL and the tentorium of the notch was observed in one case. Total synovectomy of the ACL sheath removing part of the ligamentous fibres was performed in eight cases. An isolated cyst was removed in one. Plasty of the notch was performed in one. Pathology reported degenerative dystrophic lesions in eight cases and haemopigmented villonodulary synovitis in one. All patients were reviewed at a mean follow-up of 14 months (8–48). Pain at hyperflexion had completely subsided and there was no hydrarthrosis. The Lachmann was stiff and symmetrical. Conclusion: The term ACL cyst is probably inappropriate because we were unable to find true cystic formations but rather a spontaneous degenerative process. Synovectomy of the sheath gave good clinical results. MRI findings can be a diagnostic pitfall: a destructured aspect of the ACL without a context of trauma should suggest spontaneous degeneration of the anterior cruciate ligament

Treatment of unicameral bone cysts ranges from injections of corticosteroids, bone marrow with allogenic demineralised bone matrix to open bone grafting procedure. These procedures have their own disadvantages in form of infection, fracture, long-term morbidity, repeat procedure and high recurrence rate. We describe here a new, technically simple and safe technique with minimal morbidity and short hospital stay. We treated 2 young children with active bone cyst (that did not heal with pathological fractures in past 18 months) by this technique and in both the cases bone cyst healed without any complications. In patient with active bone cyst at the proximal end of humerus, under image intensifier control distal humerus perforated with 3.5 mm drill and a pre bent 2.5 mm, flexible, intramedullary nail passed into the medullary canal and then to proximal end of bone cyst. Nail now rotated sequentially at 5 mm intervals to destroy the architecture of the cyst completely until no resistance is felt. Wound closed with skin sutures and steristrips. Post operatively both children were comfortable and discharged home next day. In both cases cyst healed uneventfully. Though we have small experience but technique looks very promising

Purpose: Aneurysmal bone cyst is a benign osteodystrophic pseudotumor. It can occur as a primary lesion or develop on a pre-existing lesion. The etiopathogenesis, diagnosis and treatment remain subjects of interest. Material and methods: For this retrospective analysis, we collected 48 peripheral aneurysmal bone cysts over a 27-year period. Most cysts occurred in children, adolescents, or young adults, with a slight female predominance. Imaging included standard x-rays, computed tomography, and for the more recent cases magnetic resonance imaging (MRI). MRI provided new imaging features increasing diagnostic accuracy. Second readings of histology slides enabled establishment of the correct diagnosis in certain cases but differential diagnosis was established only with benign tumours. Surgical treatment predominated. Other treatments included curettage-filling with cancellous bone, resection, resection-reconstruction,curettage-filling with cement. Adjuvant treatments mainly involved use of calcitonin. Therapeutic abstention with surveillance confirmed the possibility of spontaneous regression after biopsy. Curettage-filling with cancellous bone was performed in 58% of cases, giving an Enneking function score of 95.7%. Results: We reviewed outcome at mean 7 years follow-up. There were four recurrent cysts and the mean global Enneking score was 95%. Our series showed the several methods can be used for the treatment of aneurysmal bone cysts, the indication taking into consideration the patient’s age, the location of the lesion and is progression. We propose a therapeutic schema. The role of calcitonin remains to be determined. Conclusion: The diagnosis of bone cysts requires a close collaboration between the surgeon, the radiologist, and the pathologist. The indication for surgery must be made case by case to achieve cure without sequelae

Background. Unicameral bone cysts (UBCs) are difficult to treat and have a high recurrence rate. Their pathogenesis is unknown making targeted therapies difficult. Attributed causes include venous and interstitial fluid obstruction, oxygen free radicals, lysosomal enzymes, prostaglandins and genetic factors. Skeletal stem cells (SSCs) are osteoblast precursors critical to bone formation and cyst fluid may influence their growth, however the association between SSCs and cyst fluid has never been investigated. Aim. To investigate the effect of UBC fluid on SSC growth. Methods. Fluid was aspirated from a UBC in the proximal femur of a nine year old boy and centrifuged to isolate the acellular supernatant. SSCs were harvested from bone marrow of a haematologically normal adult and cultured with graded concentrations of cyst fluid in culture media (0,10,25,50%). Cell growth was assessed by alkaline phosphatase staining, and cytokine levels in the fluid were measured. Results. High levels of cytokines known to be chemo-attractive for cells of the of macrophage-monocyte lineage were found, including Macrophage Chemotactic Protein-1 (1853pg/ml), Monokine Induced by γ-interferon (656pg/ml), Macrophage Inflammatory Protein (MIP)-1α (401pg/ml) and MIP-1β (34pg/ml) suggesting a role of osteoclasts in UBC pathogenesis. Furthermore, SSC growth in vitro was reduced in cyst fluid in a concentration dependent manner. Conclusion. This is the first time altered SSC and osteoprogenitor function has been associated with the fluid of a UBC. A negative effect on osteogenesis was demonstrated, the precise mechanisms of which are under investigation, and macrophage-monocyte chemokines suggest high osteoclast activity. This study has indicated a role of the cyst fluid in limiting osteogenesis and bone turnover, which may explain the high failure rate for current interventions. More patients are needed to validate these findings

Aim: Unicameral bone cysts are difficult to treat as partial cyst healing may reverse and it may be difficult to assess between active and latent types. Materials and Methods: 19 patients with unicameral bone cysts were reviewed with a mean age of 8.5 years (16 males and 3 females). These 19 patients were reviewed over a period of fifteen years and all except one, had an active cyst abutting the growth plate. 18 cases were treated with curettage and burring using a dental burr and six cases were treated with elastic nailing. 12 cases were treated with bone marrow injection either alone or in combination with the above procedures. 2 cases were treated with steroid injections. No cases were bone grafted. Results: The best results were obtained with curettage and burring of the lining of the cysts. Bone marrow injection alone did not produce resolution of any of the cysts. Migration of the cysts away from the growth plate in response to treatment (conversion from active to latent status) was predictive of successful treatment with no symptoms and no further fractures, irrespective of the age of the patient. Conclusion: Successful treatment of unicameral bone cysts can be predicted by the appearance of normal bone formation by the physis and subsequent migration of the cyst away from the growth plate. The association of successful treatment and conversion to latency of the cyst has not previously been reported

Giant synovial cyst is commonly seen in association with rheumatoid arthritis. The Baker’s cyst around the knee is the commonest example but it has also been described at the elbow and hip. The possibility of a synovial cyst around the hip is unfamiliar to most clinicians including those who regularly deal with inguinal swellings and those specialising in musculoskeletal conditions. This is often overlooked as a cause of symptoms in inguinal area and lower limb. We present a report on two patients in whom abnormal pulsatile masses in the groin caused diagnostic difficulty. Patients were initially admitted under vascular surgeons with a clinical diagnosis of aneurysm. Ultrasound examination was useful in excluding aneurysm. Detailed clinical examination revealed painful restricted hip movements and an X–ray showed evidence of arthritis in hip joint. CT Scan confirmed it to be a synovial cyst. Computed Arthrotomogram or Arthrography showed communication of the cyst with hip joint. Synovial cysts and iliopsoas bursa enlargement may be more common than previously reported. They may present as a pulsatile mass due to close proximity to femoral vessels and should be considered as a differential diagnosis in patients with unusual inguinal swelling

Aim: The purpose of this study was to describe the prevalence, recurrence rate and disease-free interval of aneurysmal and juvenile bone. Methods: A analysis of 141 cases of cystic bone lesions recorded in the Vienna Bone Tumor Registry between 1970 and 2000 was performed. 73 aneurysmal and 68 juvenile bone cysts were registered. 128 (92%) cases were managed by intralesional curettage and adjunctive chemical cautery with phenol followed by bone grafting. Seven cases (4%) were treated by single curettage, in four cases (2.8%) a marginal enbloc resection was performed and two (1.2%) cases were treated by intracystic injections of methylprednisolone acetate. All patients were followed up for a mean of 36 months (range, seven to 144 months) with frequent clinical and radiological examination. Results: The annual prevalence of aneurysmal bone cyst was between 0 and 1.238 per 105 individuals and for juvenile bone cyst between 0 and 0.963. The median age was 11.1 years (range 1– 19.7 years) with a male to female ratio of 1:1.81 for aneurysmal bone cyst and 10.4 years (range 0.5–19.9 years) and a rate of 1:1.96 for juvenile bone cyst. The cumulative probability of a survival without months after surgery was 0.83 (95% confidence interval, 0.77 to 0.90) for aneurysmal bone cyst and 0.79 (95% confidence interval, 0.69 to 0.90) for juvenile bone cyst. Conclusion: We think that the intralesional curettage with additional phenol induced cautery followed by bone grafting provides excellent results and is a successful and sufficient procedure in the therapy of these non-neoplastic bone lesions

Aim: To evaluate the role of selective arterial embolization of Aneurysmal Bone Cyst of the mobile spine (C1-L5). Ten to 35% of aneurysmal bone cyst arises from the mobile spine. The course of the disease depends on the aggressiveness of the tumor, as well as the treatment. No previous series analyses this aspect. Methods: Fourteen cases of Aneurysmal Bone Cyst of the mobile spine were retrospectively reviewed. All charts, radiographs, and images were reviewed allowed for oncologic and surgical staging of these cases. The mean follow-up was 3,5 years (2,5y Ð 11y) and the mean age at diagnosis was 22 years. Lumbar and cervical spine was more frequently involved (5 cases cervical and 5 lumbar). Histologic diagnosis was obtained in all cases. A slow and gradual onset of pain was the constant symptom. In all cases an arterial study was performed and in thirteen cases a selective arterial embolization (SAE) was performed. Six of them were repeated Results:Only two patients shows complete ossiþcation of the cyst without surgery (T10 and T1) and was curative. All the others patients received surgical treatment (curettage or en bloc excision) In three of them a recurrence of disease was diagnosed 6, 8 and 12 months later. Two of the most recent cases shows a little lityc area without symptoms Conclusions: Selective arterial embolization seems NOT be sufþcient to obtain ossiþcation of Aneurysmal Bone Cyst o mobile spine

We report a case of an aneurysmal cyst localized in the patella of a 37-year-old man. The lesion was secondary to a chondroblastoma at six years follow-up after initial curettage and bone graft. It were no recurrence. Treatment of aneurysmal cysts depends on the degree of articular involvement. We made a detailed study of 11 cases of this rare localization of aneurysmal cysts reported in the literature

Purpose: Many surgical techniques have been described for the treatment of pathological fractures due to aggressive unicameral bone cysts in order to varying rates of success and incomplete healing or recurrence. Many Authors suggested curettage and bone grafting as effective treatment in case of active lesion in children 8 – 12 years old, adjacent to the physis with width of the lesion exceeds that of the adjacent physis and recurrence or persistence. Due to invasive nature of operation this method non is preferred by several Authors : we preferred minimally invasive treatment consisting closed reduction and flexible with titanium rod (Nancy)intramedullary fixation for low operative morbidity whether for the fracture or for the cyst; in case of recurrence of the cyst the closed curettage of the cyst with arthroscopic technique can be applied successful. Methods: Between 2002–2004 40 aggressive unicameral cysts were observed as pathologic fractures in patients between 5–15 years old in these cases there was a significant loss of bone stock. The site of involvement was in 33 patients the metadiaphysis of humerus, in 7 the femur; radiograms reveal expanding lesion in metaphyseal-diaphyseal site with cortex tinned from its inner surface and erosion with infraction with displacement. The parents were informed about contextual presence of two lesions: the fracture and cyst. The proposed internal fixation with Nancy titanium rods heals the first and might heal the second lesion ; in case of failure this method do not exclude another possibility of treatment as arthroscopic curettage. The Nancy flexible intramedullary fixation was performed with retrograde access 3 0 4 mm. diameter. Two nails with “ Eiffel Tower” construction were inserted by two miniportals 1 centimetres far from the physis. Follow up of treated lesion was made with periodic x rays performed every 45 days. Results: In 36 patients after a 2-year period of observation the cyst has completely or incompletely healed but with a sufficient bone stock in the remainder four cases the arthroscopic procedure was performed. Curettage of cystic wall by trimmer blade and multiple miniportals 4,5 millimetres is the best way to treat all the cyst. In all the cases we used the standard optical cannula 30°. Conclusions: In conclusion minimally invasive treatment by Nancy rods and artrhoscopy can be effective because assure high incidence of favourable results by decompression-scaffolding of the lesions, the patient quickly recover natural life and school attendance

The nature of the Aneurysmal Bone Cyst (ABC) is still controversial among benign tumor, often identifiable in the “aggressive” form (Enneking stage 3) or pseudotumoral lesion. It is well known instead the very high risk of intraoperative bleeding, indicating a strongly unfavorable relationship between the surgical morbidity and the nature of the disease. Recently, excellent results have been obtained in the treatment of ABC by repeated arterial embolizations (SAE), without any surgery, while initial experiences with administration of denosumab and doxycycline are still under study. This study presents the results of our initial experience in the treatment of vertebral ABC through the use of concentrated autologous mesenchymal stem cells (MSCs). Two teenagers aged 15 years, male, and 14 years, female, came to our attention both with diagnosis of ABC in C2 vertebra which was histologically confirmed. They were both neurologically intact, the girl complained of neck pain. The arteriography showed in both cases close relationships between the pathological ABC vascularization and the vertebral and cervical ascending arteries, making treatment by selective arterial embolization unsuitable. After discussion with the parents of patients, we jointly decided to undertake the treatment by direct injection of MSCs preceded, in the same operative session, by harvesting from the iliac crest of 60 cc of bone marrow (by needle aspiration) and its separation with the use of concentration system Res-Q ™ 60 BMC. In the second case the treatment was repeated two times at distance of 4 months. The clinical and radiological follow-up is to of 30 months from the first treatment in both cases. In the first case the presence of newly formed bone within the ABC appeared as a clear sign of recovery just a month after the first treatment and increased gradually, until the cyst appeared completely ossified one year after the treatment, with associated disappearance of the pain. In the second case an initial sclerotic peripheral margin appeared after the second treatment and later ossification progressed, concurrently with the disappearance of the pain. Treatment with selective serial arterial embolization is considered effective in the treatment of ABC even if not without risks, mainly related to the frequent and repeated exposure to ionizing radiation. Furthermore, in a certain percentage of cases the procedure is not technically executable, especially for the presence of arteries afferent to the medullar vascularization. Inconsistent results were obtained with other procedures: the injection of calcitonin, steroid, alcoholic solutions, or the use of sclerosing substances. Radiation therapy, though very effective, it is not considered the first choice. Recently, promising results have been achieved by the injection of mononuclear cells derived from bone marrow in the treatment of Aneurysmal Bone Cyst. Based on the early results obtained in the two cases described, the injection of MSCs can be considered a valid alternative in the treatment of vertebral ABCs untreatable by embolization