Bone grafting for periprosthetic bone cysts following total ankle arthroplasty.

Aims: The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan. Methods: We reviewed a total of 37 ankles (34 patients) that had undergone bone grafting for periprosthetic bone cysts. A CT scan was performed one year after bone grafting to check the status of graft incorporation. For accurate analysis of cyst volumes and their postoperative changes, 3D-reconstructed CT scan processed with 3D software was used. For functional outcomes, variables such as the Ankle Osteoarthritis Scale score and the visual analogue scale for pain were measured. Results: Out of 37 ankles, graft incorporation was successful in 30 cases. Among the remaining seven cases, four (10.8%) exhibited cyst re-progression, so secondary bone grafting was needed. After secondary bone grafting, no further progression has been noted, resulting in an overall 91.9% success rate (34 of 37) at a mean follow-up period of 47.5 months (24 to 120). The remaining three cases (8.1%) showed implant loosening, so tibiotalocalcaneal arthrodesis was performed. Functional outcomes were also improved after bone grafting in all variables at the latest follow-up (p < 0.05). The mean incorporation rate of the grafts according to the location of the cysts was 84.8% (55.2% to 96.1%) at the medial malleolus, 65.1% (27.6% to 97.1%) at the tibia, and 81.2% (42.8% to 98.7%) at the talus. Smoking was identified as a significant predisposing factor adversely affecting graft incorporation (p = 0.001). Conclusion: Bone grafting for periprosthetic bone cysts following primary TAA is a reliable procedure with a satisfactory success rate and functional outcomes. Regular follow-up, including CT scan, is important for the detection of cyst re-progression to prevent implant loosening after bone grafting.

Management of Periprosthetic Bone Cysts After Total Ankle Arthroplasty.

Modern improvements in total ankle arthroplasty (TAA) have increased the performance of this procedure for treatment of end-stage ankle arthritis. A common finding after TAA is the formation of periprosthetic bone cysts, which can be clinically silent or result in TAA failure. The exact cause of periprosthetic bones cysts has not been established, but major theories are related to osteolysis secondary to implant wear, micromotion, and stress shielding. Treatment can be nonoperative with clinical observation for small, asymptomatic cysts. Large, progressive, and symptomatic cysts often merit surgical treatment with debridement and grafting, revision TAA, or salvage arthrodesis.

Why do subchondral cysts occur at the medial aspect of the femoral head in hip dysplasia?

INTRODUCTION: Osteoarthritis in dysplastic hips should develop from the lateral side of the acetabulum and the femoral head just below. However, the existence of subchondral cysts located more on the medial side contradicts the weight-loading theory. The aim of this study was to confirm the presence of medial cysts at the femoral head and to investigate the relationship between medial cysts and injuries of the ligamentum teres in hip dysplasia. METHODS: A retrospective analysis was conducted on 257 cases of hip dysplasia. All patients had x-rays and 3-dimensional computed tomographies (3D CT) preoperatively and 123 patients had magnetic resonance arthrographies. A comparison was performed between cases with and without medial cysts according to the severity of damage to the ligamentum teres, the presence of bony spurs around the fovea capitis, and the Tönnis grade. RESULTS: Medial subchondral cysts around the fovea capitis were found in 100 cases. Mild osteoarthritis (Tönnis grade 0 or 1) was present in 89% of cases in the medial cyst group. A significant difference between the groups was observed in the incidence of bony spurs around the fovea capitis (p < 0.05) and injuries of the ligamentum teres (p < 0.05). CONCLUSIONS: The formation of subchondral cysts at the medial femoral head in hip dysplasia may be related to damage in the ligamentum teres. Considering that subchondral cysts develop in early osteoarthritis, the progression of arthritis in hip dysplasia appears to correlate with damage to the ligamentum teres, as well as compressive pressure on the joint.

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.

Proximal Femoral Bone Cyst After Single Screw Fixation for Slipped Capital Femoral Epiphysis: A Case Report.

CASE: An 11-year-old female patient underwent bilateral in situ fixation for slipped capital femoral epiphyses using single, cannulated, stainless steel screws. She presented 12 years later with a large osteolytic lesion of the proximal femur, which only involved 1 side. Histological evaluation showed a foreign-body reaction and synovial lining. Infection was ruled out and dynamic hip screw stabilization, and bone grafting were performed. The bone graft healed, and the hardware was removed to prevent a similar reaction. In retrospect, postoperative radiographs at 7 weeks showed subtle osteolysis along the screw. CONCLUSION: Intra-articular drilling, vertical screw placement into the posterior epiphysis, and the prominent screw head may have led to this unexpected complication.

Post-traumatic cystic lesion following radius fracture: a case report and literature review.

BACKGROUND: Post-traumatic osseous cystic lesions represent a rare complication in children. Usually a post-fracture cyst is a lipid inclusion cyst, which is radiolucent and may be seen adjacent to a healing torus fracture. It is typically asymptomatic and appears just proximal to the fracture line within the area of subperiosteal new bone formation. CASE REPORT: We report a case of post-fracture cyst of the distal radius in an 8 year-old girl with spontaneous resolution. A fat-fluid level within the subperiosteal cystic lesion in MRI is a typical feature of post-traumatic cystic lesion in children. DISCUSSION AND CONCLUSION: MRI or CT scan is sufficient to confirm the diagnosis of post-traumatic cystic lesions without the need for further management other than reassurance and advise that they may occasionally cause discomfort but resolve with time.

A rare case of multiple and huge simple bone cysts in Wilson's disease.

A simple bone cyst is a tumor-like lesion that is not a true neoplasm. It usually presents as a solitary lesion within the proximal humerus and proximal femur. The etiology of simple bone cysts is still to be elucidated. We describe our experience in the successful surgical management of a rare case of two, large-sized, simple bone cysts involving the entire left humerus and right femoral head, respectively, in a 34-year-old male patient with Wilson's disease and concomitant hepatic cirrhosis. We theorized that Wilson's disease could be the cause of the delay or blockage of the natural healing process of the simple long-bone cysts, leading to their abnormal growth and development. To our knowledge, such a combined occurrence of multiple, simple long-bone cysts and Wilson's disease has not been reported in the literature to date.

Clinical Benefit of an Adsorptive Technique for Elderly Long-Term Hemodialysis Patients.

BACKGROUND: With the advancement of technology, a dialysis membrane has been developed to achieve the efficient removal of beta-2 microglobulin (ß2MG), which could not be removed with previous hemodialysis (HD) membranes. Recently, there has been an increase in the population of elderly chronic kidney disease (CKD) patients with chronic inflammation and malnutrition. The optimal extracorporeal circulation treatment for elderly CKD patients is not certain. SUMMARY: We have reported the clinical advantages, such as improvements in nutritional, inflammatory, and hemodynamic conditions, of the adsorptive HD membrane for elderly HD patients. We have also reported that the use of ß2MG adsorption columns improved the symptoms of dialysis-related amyloidosis and the number of bone cysts, which could not be improved by the high-flux hemodialyzer. Both the adsorptive HD membrane and ß2MG adsorption columns remove uremic toxins and inflammatory cytokines via adsorption without aggravating the nutritional condition of these patients. Key Messages: We should reconsider the mechanisms of adsorption, in addition to diffusion and convection, in the extracorporeal circulation treatment of elderly HD patients.

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.

Scaphoid Cysts: Literature Review of Etiology, Treatment, and Prognosis.

Background: Cystic lesions of the carpal bones are rare entities that are infrequently reported in the literature. Scaphoid intraosseous cystic lesions represent a rare subset of carpal bone cysts. This review aims to summarize the available evidence on the evaluation and treatment of scaphoid cystic lesions to help guide clinical management. Methods: Systematic electronic searches were performed using PubMed, Ovid, and Embase databases. Studies included were graded for their risk of bias. Pooled descriptive statistics were performed on incidence, etiology, physical exam findings, treatment, and follow-up. Results: A total of 38 patients representing 41 scaphoid cystic lesions were pooled from 27 articles. Patients presented with wrist pain without fracture (n = 27), pathological fracture (n = 9), swelling only (n = 1), or were asymptomatic (n = 4). Cystic lesions of the scaphoid were initially revealed on imaging with radiographs alone (n = 22), radiographs in combination with computed tomography (CT) (n = 10) or magnetic resonance imaging (n = 6), CT alone (n = 1), or using all 3 modalities (n = 2). Intraosseous ganglia were identified most frequently (n = 31), followed by "bone cyst-like pathological change" (n = 3), unicameral bone cysts (n = 2), aneurysmal bone cysts (n = 2), primary hydatid cysts (n = 2), and cystic like changes post fall (n = 1). Treatment modalities included curettage and bone graft (n = 39) or below-elbow cast (n = 2). On follow-up (average of 21.3 months; n = 40), all patients improved clinically after treatment and were found to have full wrist range of motion without pain (n = 31), slightly reduced grip strength (n = 3), limited range of motion (n = 2), or persistent mild discomfort (n = 2). Conclusions: Scaphoid cystic lesions are most commonly intraosseous ganglia, but can include other etiologies as well. The main presenting symptom is radial wrist pain that usually resolves after treatment. The presence of intracarpal cystic lesions should be considered in the differential diagnosis of wrist pain.

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.

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.

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.

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.

Large tibial geode, which developed several years after a left medial Oxford unicondylar knee arthroplasty, treated with curettage and bone grafting.

BACKGROUND: Tibial geodes are rare, and usually reported in association with rheumatoid arthritis. This case study reported the rare occurrence of a tibial geode in association with a left unicondylar knee arthroplasty (UKA). The patient, a 55-year-old male, was initially pleased with his UKA, which was performed at another institution. However, just over one year after the operation he began experiencing pain and discomfort. He did not present to the current institution until he was six years after UKA. This pain was movement and weight bearing related, although he still managed to maintain an active lifestyle working as a builder. After several years of follow-up, a computed tomography (CT) scan showed a significant increase in size of the geode. METHODS: The patient initially did not want to undergo further surgery, as he was self-employed, but it was decided, in conjunction with the patient, that it was time to operate because the stability of the prothesis was in question. Transcortical and retrograde curettage of the geode was performed and one and a half femoral head allografts were used to fill the geode. RESULTS: Follow-up since the operation showed good infilling of the geode and bone remodelling, with resolution of symptoms at 12 months. CONCLUSIONS: This case report was the first to report a symptomatic tibial geode in close association with UKA, which did not lead to revision surgery to total knee arthroplasty (TKA), but instead was successfully treated with currettage and bone grafting.

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.

Subchondral Bone Degradation After Microfracture for Osteochondral Lesions of the Talus: An MRI Analysis.

BACKGROUND: Microfracture is the most common cartilage-reparative procedure for the treatment of osteochondral lesions of the talus (OLTs). Damage to the subchondral bone (SCB) during microfracture may irreversibly change the joint-loading support of the ankle, leading to reparative fibrocartilage degradation over time. PURPOSE: To investigate the morphological change in the SCB after microfracture for OLT by developing a novel magnetic resonance imaging (MRI) scoring system specifically for evaluating the SCB. Furthermore, this study assesses the influence of the morphological changes of the SCB on clinical outcomes based on the new score. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Forty-two patients who underwent microfracture for OLT were included. An SCB Health (SCBH) scoring system was developed according to the amount of edema, subchondral cyst diameter, and qualitative and thickness change in the SCB, with a total score of 12 indicating normal SCB. MRI was obtained postoperatively from 6 months to 1 year, 1 to 2 years, 2 to 4 years, and 4 to 6 years. The Foot and Ankle Outcome Score (FAOS) was evaluated preoperatively and at 2 years and final follow-up. RESULTS: The mean patient age was 38.4 ± 15.6 years, with a mean follow-up of 51.7 ± 22.8 months. The mean FAOS improved significantly from 57.8 ± 14.4 preoperatively to 84.3 ± 7.2 at 24 months ( P < .001) and decreased to a final mean value of 77.1 ± 12.6 ( P < .001). The mean SCBH score decreased from 8.6 ± 1.9 preoperatively to 7.1 ± 1.8 on the first follow-up MRI ( P < .001) and significantly decreased to 5.9 ± 2.3 on the fourth follow-up MRI ( P < .001). Subchondral cysts were noticeably worse at the fourth follow-up MRI than at the first and second ( P < .001, P = .006, respectively). There was a positive correlation between the final FAOS and the SCBH score on the third and fourth follow-up MRI ( r = 0.55, P < .001; r = 0.70, P < .001, respectively), but no correlation was found on the first and second follow-up. CONCLUSION: The SCBs following microfracture for OLT were not restored at midterm follow-up. There was a significant decrease of the overall SCBH score over time. Noticeably, subchondral cysts deteriorated over time consistently. In addition, the SCBH score at midterm follow-up was positively correlated with clinical outcomes. Lasting morphological changes in the SCB may be indicative of longer-term failure of the microfracture procedure.

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.

[First results with a resorbable MgYREZr compression screw in unstable scaphoid fractures show extensive bone cysts]. / Erste Ergebnisse mit einer resorbierbaren MgYREZr-Kompressionsschraube bei der instabilen Kahnbeinfraktur zeigen eine massive Zystenbildung.

Osteosynthesis with headless compression screws is an established treatment option for unstable scaphoid fractures. Common implants are made of titanium alloy or steel and usually remain in place. Due to implant density and ferromagnetic properties, artefacts are common in postoperative imaging procedures, e.g. MRI. Now resorbable implants made of magnesium alloy (MgYREZr) have become available. They have biomechanical properties equivalent to human bone and may be used as an alternative to the nonresorbable screw systems.5 patients with acute scaphoid fractures were treated with a double-threaded screw made of MgYREZr. The fractures included three type A2 fractures, one type B2 fracture, and one type B3 fracture. All patients underwent clinical and radiological follow-up postoperatively, 6 weeks, 3 and 6 months and 1 year after surgery. ROM, gross grip strength and pain (VAS) were documented. The Modified Mayo Wrist Score was used. Standard X-rays of the wrist were taken preoperatively and at all follow-up visits. A CT scan was performed at least before and three months after surgery. In all X-rays malunion, resorption of the implant, implant loosening, cysts and bone healing (bridging trabecular structures) were described.All patients had a very good wrist score (95-100 points) after one year. There were no clinical complications. However, the X-rays revealed extensive resorption cysts in 3 out of the 5 patients. It was only after 6 months that the fractures were consolidated enough to allow physical work. Due to this considerable osteolysis, we did not include any further patients. Due to the observed extensive bone cysts and the long time period for bone healing, MgYREZr compression screws are currently not recommended for clinical use in scaphoid fractures. Further fundamental research is necessary.