Pediatric physeal slide-traction plate fixation for pathological distal femoral fracture caused by unicameral bone cyst in adolescents.

BACKGROUND: Most patients suffering from distal femoral unicameral bone cysts (UBCs) are adolescents that require an early return to normal activities, including school attendance and sports exercises. However, the optimal choice of implants for such patients remains controversial. This study evaluated the application of pediatric physeal slide-traction plate (PPSP) in the treatment of pathological distal femoral fracture caused by UBCs. METHODS: Between Jan 2014 and Jan 2016, 11 (male = 6, female = 5) patients were reviewed retrospectively. Age, sex, operative time, limb-length discrepancy (LLD), and valgus angulation were all recorded for every patient. RESULTS: The average age of 11 patients was 12.2 ± 1.1 years. The operating time was 94.8 ± 7.8 min. The postoperative hospital stay was 5 to 7 days. The epiphyseal morphology in the operative leg was nearly normal. The plate was removed in an average of 19.5 ± 3.1 months. The knee range of motion (ROM) was normal in 9 patients, whereas 2 female patients reported a loss of less than 10 degrees of ROM as compared to the contralateral knee joint. Breakage of plates or refracture did not occur in our cases. All patients had a follow-up of at least 24 months. At the latest follow-up visit, all patients walked without a limp. None of the patients manifested obvious LLD and valgus deformity. CONCLUSION: PPSP combined with curettage and bone grafting allows early mobilization and produces satisfactory outcomes for pathological fracture of distal femur secondary to UBCs in adolescents.

Concentrated Bone Marrow Aspirate May Decrease Postoperative Cyst Occurrence Rate in Autologous Osteochondral Transplantation for Osteochondral Lesions of the Talus.

PURPOSE: To clarify if the use of concentrated bone marrow aspirate (CBMA) would affect both postoperative functional outcomes and magnetic resonance imaging (MRI) outcomes compared with those of autologous osteochondral transplantation (AOT) alone; in addition, to assess the efficacy of CBMA reducing the presence of postoperative cyst formation following AOT in the treatment of osteochondral lesions of the talus. METHODS: Fifty-four (92%) of 59 eligible patients who underwent AOT between 2004 and 2008 were retrospectively assessed at a minimum of 5-year follow-up. Twenty-eight patients were treated with AOT and CBMA (AOT/CBMA group) and 26 patients were treated with AOT alone (AOT-alone group). Clinical outcomes were evaluated using the Foot and Ankle Outcome Scores (FAOS) and Short-Form 12 (SF-12) preoperatively and at final follow-up. Postoperative MRI was evaluated with the modified Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. Cyst formation was also evaluated on postoperative MRI. RESULTS: The mean FAOS and SF-12 significantly improved in both the AOT/CBMA and AOT-alone groups, but there were no statistical differences between groups in FAOS (80.5 vs 75.5, P = .225) and SF-12 (71.1 vs 69.6, P = .756) at final follow-up. Additionally, there was no difference in the mean MOCART score (80.4 vs 84.3, P = .484); however, AOT/CBMA did result in a statistically lower rate of cyst formation (46.4% vs 76.9%, P = .022). No significant differences were found in the mean postoperative FAOS and SF-12 between patients with and without cysts postoperatively. CONCLUSIONS: CBMA reduced postoperative cyst occurrence rate in patients treated with AOT; however, CBMA did not result in significant differences in medium term functional outcomes and MOCART score in patients who underwent AOT. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Understanding Unicameral and Aneurysmal Bone Cysts.

Bone cysts in the pediatric population are often found incidentally on radiographs or after a cyst has created cortical weakness leading to a pathologic fracture. Most bone cysts are benign, are pain free, and resolve spontaneously. The most common bone cyst is unicameral 1-chamber bone cyst, also known as simple bone cyst. General practice pediatricians may be the first to encounter these lesions, and this article aims to help elucidate their incidence, etiology, clinical findings, radiologic findings, and modern treatment approaches. The other differential diagnoses that should be considered, specifically, aneurysmal bone cyst, are also explored. This summary is not all inclusive, and it is recommended that all patients be referred to a pediatric orthopedist.

Peri-prosthetic bone cysts after total ankle replacement. A systematic review and meta-analysis.

BACKGROUND: Periprosthetic cystic osteolysis is a well-known complication of total ankle replacement. Several theories have been proposed for its aetiology, based on individual biomechanical, radiological, histopathology and outcome studies. METHODS: Studies that met predefined inclusion/exclusion criteria were analysed to identify literature describing the presence of peri-prosthetic ankle cystic osteolysis. Quantitative data from the selected articles were combined and statistically tested in order to analyse possible relations between ankle peri-prosthetic bone cysts and specific implant characteristics. RESULTS: Twenty-one articles were elected, totalizing 2430 total ankle replacements, where 430 developed peri-prosthetic cystic osteolysis. A statistically significant association (P<.001) was found between the presence of bone cysts and non-anatomic implant configuration, hydroxyapatite-coating, mobile-bearing and non tibial-stemmed implants. No significant association existed between the type of constraining and the presence of cysts (P>.05). CONCLUSIONS: Non-anatomic, mobile-bearing, hydroxyapatite-coated and non tibial-stemmed total ankle replacements are positively associated with more periprosthetic bone cysts.

Less common manifestations in TSC.

Tuberous sclerosis complex (TSC) is due to pathogenic variants in TSC1 or TSC2 genes resulting in hyperactivation of the mTOR pathway. Many organ systems can be affected, such as brain, skin, eye, heart, bone, kidney, or lung. Typical lesions of TSC usually are those included as major criteria, including angiofibromas, hypomelanotic macules, tubers, subependymal nodules, angiomyolipomas, cardiac rhabdomyomas, and lymphangioleiomyomatosis. However, there are many other manifestations less frequent and/or less well known, many of them not included as clinical diagnostic criteria that are part of the clinical spectrum of TSC. The focus of this review will be on these less common and less well-known manifestations of TSC. Among the rare manifestations, we will discuss some clinical findings including arteriopathy, arachnoid cysts, lymphatic involvement, chordomas, gynecological, endocrine, and gastrointestinal findings. Among the manifestations that are very frequent but much less well known, we find the sclerotic bone lesions. Although they are very frequent in TSC they have been largely overlooked and not considered diagnostic criteria, mainly because they are asymptomatic. However, it is important to know their typical characteristics to avoid misdiagnosing them as metastasis.

Radiological analysis of cystic lesion in osteonecrosis of the femoral head.

PURPOSE: Cystic lesions are a common complication in osteonecrosis of the femoral head (ONFH). This study will discuss the cause of cystic lesion formation and the feature of cystic lesion distribution in ONFH. According to the feature of cystic lesion in ONFH, we will discuss the possible mechanisms of cystic lesions and their  influence on collapse of the femoral head. MATERIALS AND METHODS: We retrospectively gathered 102 ONFH patients (168 hips) from November in 2015 to August in 2016 on China-Japan Friendship Hospital. Three categories of patients' medical information were collected: demographic characteristics, bone cystic lesion location, and pathological finding on CT and MRI imaging (microfracture, collapse, crescent sign). On mid-coronal and mid-axial CT section, the femoral head was divided into four quadrants for locating the cystic lesion. And we classified the location relationship of cystic lesion and sclerosis rim as G1 type, G2 type, and G3 type on coronal CT section. RESULTS: A significant difference was found between ONFH group with cystic lesion and ONFH group without cystic lesion in terms of microfracture (P < 0.001), collapse (P < 0.001), and crescent sign (P < 0.001). Forty-four cystic lesions (70%) are located in anterior hip area and 19 cystic lesions (30%) are located in posterior hip area. There were 14, 24, and seven cystic lesions (31, 53, 16%) locating in lateral, central, and medial pillars of the femoral head. G2 type was the most common pattern of location relationship between cystic lesion and sclerosis rim. CONCLUSION: Cystic lesions are often found near sclerosis rim in ONFH. The femoral head with osteonecrosis complicating by cystic lesions is more likely to accompany microfracture, collapse, and crescent sign which indicate structural instability in the femoral head. Cystic lesion in ONFH plays an important role in aggravating the progression of femoral head collapse. The peak stress from sclerosis rim may be a main factor inducing the formation of cystic lesion in ONFH via an OA-like mechanism.

Intraosseous epidermoid cyst of the skull: case study and radiological imaging considerations.

We report an atypical case of an epidermoid cyst associated with a skull defect to emphasize the diagnostic utility of bedside ultrasonography for the evaluation of subcutaneous scalp nodules. A 24-year-old woman presented with what appeared to be a benign cyst on the right parietal scalp. The cyst was first noticed one year prior to presentation and caused only mild irritation. Upon excision of the cyst, a notable calvarial defect was found in the frontoparietal bone and surgical excision was suspended. Head and brain imaging was performed confirming the calvarial defect with mild mass effect on the brain. A neurosurgical consultation was obtained, and the patient underwent craniotomy followed by cranioplasty with titanium plate placement. The histological evaluation confirmed the suspicion of an intraosseous epidermoid cyst. We hope to raise awareness of the potential for intraosseous involvement of otherwise routine scalp nodules and emphasize the utility of bedside ultrasonography as a quick, easy, and benign imaging modality to assist in preoperative evaluation.

Traumatic bone cyst of an anterior mandible with previous symphyseal fracture in a pediatric patient: a rare finding and etiopathologic correlation.

Traumatic bone cysts (TBCs) are uncommon intraosseous lesions, classified as pseudocysts because they lack an epithelial membrane lining. The etiology of a pseudocyst has not been determined. Various hypotheses have been put forward to explain its pathogenesis, of which the traumatic-hemorrhagic theory is the most commonly accepted. Minor trauma, insufficient to cause fracture or iatrogenic injury, is commonly implicated as the stimulus initiating cyst formation. A TBC presenting after jaw fracture has been rarely reported in the literature. This article presents a case of a TBC of the anterior mandible in a child with a previous history of trauma and fracture of the symphysis. The article also reviews the literature to corroborate the possible role of major trauma in the pathogenesis of TBC.

Osteochondrosis Can Lead to Formation of Pseudocysts and True Cysts in the Subchondral Bone of Horses.

Osteochondrosis arises as a result of focal failure of the blood supply to growth cartilage. The current aim was to examine the pathogenesis of pseudocysts and true cysts in subchondral bone following failure of the blood supply to the articular-epiphyseal cartilage complex in horses. Cases were recruited based on identification of lesions (n = 17) that were considered likely to progress to or to represent pseudocysts or true cysts in epiphyseal bone in histological sections and included 10 horses ranging in age from 48 days to 5 years old. Cases comprised 3 warmbloods, 3 Standardbreds, 1 Quarter horse and 1 Arabian with spontaneous lesions and 2 Fjord ponies with experimentally induced lesions. Seven lesions consisted of areas of ischemic chondronecrosis and were compatible with pseudocysts. Two lesions were located at intermediate depth in epiphyseal growth cartilage, 2 lesions were located in the ossification front, 2 lesions were located in epiphyseal bone and 1 lesion was located in the metaphyseal growth plate (physis). Ten lesions contained dilated blood vessels and were compatible with true cysts. In 2 lesions the dilated blood vessels were located within the lumina of failed cartilage canals. In the 8 remaining lesions areas of ischemic chondronecrosis were associated with granulation tissue in the subjacent bone and dilated vessels were located within this granulation tissue. Failure of the blood supply and ischemic chondronecrosis can lead to formation of pseudocysts or dilatation of blood vessels and formation of true cysts in the epiphyseal bone of horses.

Cartilage Thickness and Cyst Volume Are Unchanged 10 Years After Periacetabular Osteotomy in Patients Without Hip Symptoms.

BACKGROUND: Periacetabular osteotomy (PAO) may affect cartilage thickness and cyst volume in patients with hip dysplasia. However, as no studies randomizing patients to either PAO or conservative treatment have been performed, to our knowledge, it is unknown if PAO directly affects the development or progression of osteoarthritis in patients with hip dysplasia. QUESTIONS/PURPOSES: We investigated (1) changes of cartilage thickness in the hip after PAO; (2) how many patients had subchondral bone cysts in the acetabulum or femoral head; (3) changes in cyst volume; and (4) patients' hip function and pain after PAO. PATIENTS AND METHODS: In this prospective study, 26 patients (22 women and four men) with hip dysplasia were enrolled with the goal of having MRI of the hip before undergoing PAO and again at 1, 2½, and 10 years after PAO. Of the 26 patients, 17 (65%) underwent complete followup 10 years after PAO, whereas nine could not be included. Of those nine, three had undergone THA, three had substantial hip symptoms, and three were lost to followup. Thickness of acetabular and femoral cartilage and volume of subchondral bone cysts were estimated in the remaining 17 patients. Ten years postoperatively, the patients' Hip disability and Osteoarthritis Outcome Scores (HOOS) were collected. RESULTS: Preoperatively, the mean thickness of the acetabular cartilage was 1.38±0.14 mm compared with 1.43±0.07 mm 10 years postoperatively (p=0.73). The mean thickness of the femoral cartilage preoperatively was 1.37±0.20 mm compared with 1.30±0.07 mm 10 years postoperatively (p=0.24). Seven patients had an increase in cyst volume, six had a decrease, and four had no cysts to start with and remained without cysts. Preoperatively, the median total cyst volume per patient was 6.0 cm3 (range, 1.6-188.3 cm3) compared with 2.9 cm3 (range, 0.7-8.2 cm3) (p=0.18) at 10 years followup. At 10 years, the mean subscores for the HOOS were: pain, 79±16; symptoms, 73±17; activities of daily living, 85±14; sport/recreation, 68±22; and quality of life, 61±19. CONCLUSIONS: Ten years after PAO, approximately 25% of the patients who have the procedure will have substantial hip pain and/or undergo hip arthroplasty. Of the patients who do not have substantial hip pain or an arthroplasty, cartilage thickness appears to be preserved. Future studies are needed to help us decide which patients are most likely to succeed with PAO at long-term followup. LEVEL OF EVIDENCE: Level II, therapeutic study.

TREMs in the immune system and beyond.

Triggering receptors expressed by myeloid cells (TREMs) belong to a rapidly expanding family of receptors that include activating and inhibitory isoforms encoded by a gene cluster linked to the MHC. TREM1 and TREM2 activate myeloid cells by signalling through the adaptor protein DAP12. TREM1 triggers phagocyte secretion of pro-inflammatory chemokines and cytokines, amplifying the inflammation that is induced by bacteria and fungi. TREM2 activates monocyte-derived dendritic cells and regulates osteoclast development. Remarkably, TREM2 deficiency leads to a severe disease that is characterized by bone cysts and demyelination of the central nervous system, which results in dementia, implying that the function of TREM2 extends beyond the immune system.

Prognostic value of p53 protein expression in giant cell tumor of bone.

Giant cell tumor of bone (GCTB) is a benign tumor with a tendency for local recurrence. GCTB may cause lung metastases, and secondary malignant GCTB is rare. Its histological appearance does not predict local aggressiveness and/or the metastatic potential of the tumor. We aimed to investigate the prognostic value of the Ki-67 proliferative index and p53 protein expression in GCTB in predicting local recurrence, lung metastasis, and malignant transformation. We retrospectively reviewed 42 cases of GCTB. The p53 expression was positive in 20 cases. We used 10% as a cut-off value for p53 expression. In 10 cases, there were local recurrences. Lung metastases were found in three cases and malignant transformation was found in one case with classical GCTB located in the sacrum three years following diagnosis. The Ki-67 index was higher in cases with recurrence, but this difference was not statistically significant. Of the recurrent cases, two had no p53 staining while eight had moderate-to-strong staining. The staining was usually weakly positive in the non-recurrent cases. In conclusion, we believe that p53 may be used as a marker for the biological behavior of GCTB.

Severity mapping of the proximal femur: a new method for assessing hip osteoarthritis with computed tomography.

OBJECTIVE: Plain radiography has been the mainstay of imaging assessment in osteoarthritis for over 50 years, but it does have limitations. Here we present the methodology and results of a new technique for identifying, grading, and mapping the severity and spatial distribution of osteoarthritic disease features at the hip in 3D with clinical computed tomography (CT). DESIGN: CT imaging of 456 hips from 230 adult female volunteers (mean age 66 ± 17 years) was reviewed using 3D multiplanar reformatting to identify bone-related radiological features of osteoarthritis, namely osteophytes, subchondral cysts and joint space narrowing. Scoresheets dividing up the femoral head, head-neck region and the joint space were used to register the location and severity of each feature (scored from 0 to 3). Novel 3D cumulative feature severity maps were then created to display where the most severe disease features from each individual were anatomically located across the cohort. RESULTS: Feature severity maps showed a propensity for osteophytes at the inferoposterior and superolateral femoral head-neck junction. Subchondral cysts were a less common and less localised phenomenon. Joint space narrowing <1.5 mm was recorded in at least one sector of 83% of hips, but most frequently in the posterolateral joint space. CONCLUSIONS: This is the first description of hip osteoarthritis using unenhanced clinical CT in which we describe the co-localisation of posterior osteophytes and joint space narrowing for the first time. We believe this technique can perform several important roles in future osteoarthritis research, including phenotyping and sensitive disease assessment in 3D.

How to define subregional osteoarthritis progression using semi-quantitative MRI osteoarthritis knee score (MOAKS).

OBJECTIVE: Recently, the MRI Osteoarthritis Knee Score (MOAKS), a new semi-quantitative magnetic resonance imaging (MRI) scoring tool, was introduced by a panel of experienced researchers in osteoarthritis (OA). The MOAKS is primarily applicable to quantify OA status, since the interpretation of change in the MOAKS features was not described. In order to enable longitudinal evaluation, we propose definitions for progression and improvement of the main MOAKS features. METHOD: Clear definitions for progression and improvement of the main MOAKS features are given in this brief report. 687 baseline and 30 months follow-up MRIs of the knees of 348 overweight and obese middle-aged women, free of OA at baseline, were scored using the MOAKS. Baseline prevalence and the change of MOAKS features after 30 months follow-up, based on our definitions for progression and improvement, are presented. RESULTS: The proposed definitions showed 3% to 23% progression and 0% to 11% improvement in the MOAKS features during the 30 months follow-up. Overall, progression rates were higher in the medial than in the lateral tibiofemoral (TF) joint. Progression of bone marrow lesions (BMLs) and cartilage defects was highest in the patellofemoral (PF) joint. Inter-rater reliability of the MOAKS scores was moderate to nearly perfect (PABAK 0.77-0.88), with high percentage of agreement overall (89-94%). CONCLUSION: This brief report presents definitions for progression and improvement of the main MOAKS features for the longitudinal evaluation of knee OA features on MRI. We advocate uniform usage of the proposed definitions across studies, but welcome suggestions for optimization.

Development and reliability of a multi-modality scoring system for evaluation of disease progression in pre-clinical models of osteoarthritis: celecoxib may possess disease-modifying properties.

OBJECTIVE: We sought to develop a comprehensive scoring system for evaluation of pre-clinical models of osteoarthritis (OA) progression, and use this to evaluate two different classes of drugs for management of OA. METHODS: Post-traumatic OA (PTOA) was surgically induced in skeletally mature rats. Rats were randomly divided in three groups receiving either glucosamine (high dose of 192 mg/kg) or celecoxib (clinical dose) or no treatment. Disease progression was monitored utilizing micro-magnetic resonance imaging (MRI), micro-computed tomography (CT) and histology. Pertinent features such as osteophytes, subchondral sclerosis, joint effusion, bone marrow lesion (BML), cysts, loose bodies and cartilage abnormalities were included in designing a sensitive multi-modality based scoring system, termed the rat arthritis knee scoring system (RAKSS). RESULTS: Overall, an inter-observer correlation coefficient (ICC) of greater than 0.750 was achieved for each scored feature. None of the treatments prevented cartilage loss, synovitis, joint effusion, or sclerosis. However, celecoxib significantly reduced osteophyte development compared to placebo. Although signs of inflammation such as synovitis and joint effusion were readily identified at 4 weeks post-operation, we did not detect any BML. CONCLUSION: We report the development of a sensitive and reliable multi-modality scoring system, the RAKSS, for evaluation of OA severity in pre-clinical animal models. Using this scoring system, we found that celecoxib prevented enlargement of osteophytes in this animal model of PTOA, and thus it may be useful in preventing OA progression. However, it did not show any chondroprotective effect using the recommended dose. In contrast, high dose glucosamine had no measurable effects.

Bone cysts in patients with afibrinogenaemia: a literature review and two new cases.

Afibrinogenaemia is an autosomal recessive disease with an estimated prevalence of approximately one in a million. The most common symptoms of afibrinogenaemia are umbilical cord bleeding, bleeding into skin, mouth, muscles, gastrointestinal and genitourinary tracts and the central nervous system. Other recognized complications include; haemarthroses, spontaneous splenic rupture, epistaxis, menorrhagia, recurrent abortion and venous and arterial thromboembolism. Bone cysts have also been described as a rare complication of afibrinogenaemia. The aim of this study was to conduct a systematic literature review, summarize the reported cases and to report two new cases. Three electronic databases were searched for relevant publications: PubMed, Medline and EMBASE. The following search criteria were used: '(bone cysts OR intraosseous haematoma OR intraosseous haemorrhage) AND (afibrinogenaemia OR fibrinogen deficiency)'. The reference lists of the selected papers were searched for more relevant literature. In total, eight patients had bone cysts as complication of afibrinogenaemia and six of them suffered from pain in their extremities. Bone cysts were primarily located in the vicinity of the cortex or trabeculae in the diaphysis of the long bones, especially in the femora, tibiae and humeri. Some were regressive, probably due to reactive bone remodelling. A number of cysts were filled with serosanguinous fluid. It might be useful to check for bone cysts when patients with congenital afibrinogenaemia complain of 'rheumatic' pains in their extremities. Whole body magnetic resonance imaging is the diagnostic imaging technique of choice. Recurrent episodes of pain, but not radiological deterioration, appear to benefit from prophylactic therapy with fibrinogen concentrate.

Evaluation of periprosthetic bone cysts in patients with a Scandinavian total ankle replacement: weight-bearing conventional digital radiographs versus weight-bearing multiplanar reconstructed fluoroscopic imaging.

OBJECTIVE: Periprosthetic bone cysts are a known finding after total ankle replacement (TAR). The significance of cysts is uncertain, but they may threaten the long-term survival of the implant. The aim of this prospective study was to evaluate the diagnostic accuracy of weight-bearing digital radiography compared with 3D weight-bearing multiplanar reconstructed (MPR) fluoroscopic imaging when diagnosing periprosthetic bone cysts in patients who have undergone TAR. SUBJECTS AND METHODS: Forty-two consecutive patients with a Scandinavian Total Ankle Replacement (STAR) were consecutively enrolled and underwent digital radiography and 3D MPR imaging in the same session. All 3D MPR images were interpreted in a blinded fashion, specifically with regard to the presence and extent of periprosthetic bone cysts. Cysts were measured in three planes whenever possible. Interrater and intrarater reliability was assessed by using Cohen kappa test, and comparisons between the two modalities were performed with the Wilcoxon signed-rank and McNemar tests. RESULTS: Significantly more cysts were detected on 3D MPR (74 vs 55) (p = 0.03), with the mean size of cysts detected by 3D MPR significantly larger than that of cysts diagnosed on digital radiography (1545 mm(3) vs 253 mm(3)) (p < 0.0001). Statistical analysis based on the presence or absence of cysts in individual patients did not show a significant difference between 3D MPR and digital radiography (p = 0.23). CONCLUSION: The data imply that cysts are better detected and more accurately measured with 3D fluoroscopic MPR imaging compared with digital radiography, which underestimates not only the presence but also the extent of periprosthetic cysts.

Unicameral bone cysts: general characteristics and management controversies.

Unicameral bone cysts are benign bone lesions that are often asymptomatic and commonly develop in the proximal humerus and femur of skeletally immature patients. The etiology of these lesions remains unknown. Most patients present with a pathologic fracture, but these cysts can be discovered incidentally, as well. Radiographically, a unicameral bone cyst appears as a radiolucent lesion with cortical thinning and is centrally located within the metaphysis. Although diagnosis is frequently straightforward, management remains controversial. Because the results of various management methods are heterogeneous, no single method has emerged as the standard of care. New minimally invasive techniques involve cyst decompression with bone grafting and instrumentation. These techniques have yielded promising results, with low rates of complications and recurrence reported; however, prospective clinical trials are needed to compare these techniques with current evidence-based treatments.

Adverse reactions of artificial bone graft substitutes: lessons learned from using tricalcium phosphate geneX®.

BACKGROUND: Artificial bone graft substitutes are widely used to fill bony defects after curettage of benign tumors. We sought to evaluate the efficacy of one such bone graft substitute, geneX®, which contains tricalcium phosphate and calcium sulphate; however, during the course of this study we observed a high number of complications. QUESTIONS/PURPOSES: The primary aim of this prospective series was assessment of the effectiveness of geneX® concerning resorption profile and bone healing and remodeling after surgery. We present the types and frequencies of complications observed in patients treated for bone tumors by curettage and filling the defect using geneX®. METHODS: We planned to study 40 patients; however, after enrollment of the first 31 patients, the study was stopped as a result of serious complications. There were 20 female and 11 male patients with a mean age at surgery of 40 years (range, 6­71 years). Plain radiographs were obtained at different intervals during followup and CT scans were obtained 6 and 12 months postoperatively. Complications were assessed using a 5-point scale according to Goslings and Gouma. RESULTS: Five of the 31 patients (16%) had complications develop after surgery. In three cases, a sterile inflammation adjacent to the geneX® occurred, with delayed wound healing in two patients and local pain. In the third patient, geneX® produced moderate to severe skin damage in the area of the scar, needing revision surgery. In two other patients, inflammatory cystic formations developed in the soft tissues with sizes up to 15 cm, which gradually reduced in size with time. Overall, there were four Grade 1 complications and one Grade 2 according to Goslings and Gouma. CONCLUSIONS: We concluded from this series of patients that geneX® causes soft tissue inflammation and pain with its use. Based on this experience we believe that this type of bone substitute should not be used in the treatment of bony defects. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Desmoplastic fibroma of the rib with cystic change: a case report and literature review.

Desmoplastic fibroma (DF) is a rare, locally aggressive, solitary tumor microscopically composed of well-differentiated myofibroblasts with abundant dense collagen deposition. The most common sites are the long tubular bones and mandible. To our knowledge, only five cases of DF in the ribs have been reported. Here, we report a case of DF in this rare location with unusual radiological findings. A 40-year-old man presented with a 4-year history of swelling of the right chest wall. Radiographs revealed a mass at the right 9th rib, and computed tomography demonstrated a mass of 14 × 12 × 8 cm at the right 9th rib with expanded cystic change and marked calcification that appeared to have arisen from the bone. Open biopsy suggested DF. Total excision was performed, and the chest wall was reconstructed. The surgical specimen was a yellowish tumor with multilocular cystic change containing a viscous liquid. The tumor was composed of a proliferation of less-atypical spindle-shaped cells in a collagenous background. The cystic change was observed in the extra-osseous lesion. No ß-catenin cytoplasmic/nuclear accumulation was detected, and no ß-catenin or GNAS genetic mutations were detected. A final diagnosis of DF was made on the basis of the pathological and radiological findings. The patient was successfully treated with total excision of the tumor with no evidence of recurrence 6 months after surgery.