Simple bone cyst: description of 60 cases seen at a Brazilian School of Dentistry and review of international literature

BACKGROUND: The aim of this study was to describe the relative frequency and the main demographic and clinic-radiographic features related to patients diagnosed with Simple bone cyst (SBC) in an Oral Diagnosis Service in Southeast Brazil and present a review and discussion of international literature on this topic. MATERIAL AND METHODS: SBC cases from our service encompassing the period between 1978 and 2017 were selected. In addition, a literature search was performed in the Pubmed/MEDLINE online electronic database published between 1951 and 2019. RESULTS: A total of 2,459 cystic lesions were documented in our service, thus 60 patients were diagnosed with the SBC representing 2.4% of all jaw cystic. Most of cases were asymptomatic. Multiple SBC lesions were seen in two patients (3.4%) and association with cemento-osseous dysplasia was seen in one female patient (1.7%). A total of 793 cases were enrolled in this literature review. CONCLUSIONS: The SBC is an asymptomatic lesion often discovered in routine image exams in young patients. The unilocular, well defined margin with scalloped appearance is characteristic and helps the definition of diagnosis. This review suggests a different epidemiologic trend concerning to the sex and it confirms the posterior region of mandible as the more frequent location. The conservative treatment with limited exploration and curettage remains as the gold-standard treatment

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Lunate subchondral cysts: Are there specific radiologic findings for patients with symptomatic ulnocarpal impaction?

BACKGROUND: There are few clinical studies evaluating the relationship between lunate cysts and symptomatic ulnar impaction syndrome (UIS). The purpose of this study was to investigate the prevalence and relationship between lunate cysts and UIS by comparing data from patients with UIS against those without. MATERIALS AND METHODS: From March 2012 to January 2015, 375 patients who had undergone MRI or CT for reasons other than ulnar-sided wrist pain were classified into the 'asymptomatic group' (Group I). Thirty three patients who had been diagnosed with UIS were classified in the 'UIS group' (Group II). We determined whether any differences were present between the two groups and evaluated prognostic factors for lunate cysts. RESULTS: The prevalence of lunate cysts was significantly higher in Group II but only reached just above 50% (10.4% vs. 57.6%, p < 0.001]. Dorsal-side lunate cysts were more frequent than palmar side in Group I, while Group II had more cysts on the palmar side (74.4% vs. 52.6%, p = 0.001). Logistic regression analysis revealed that UIS and patient age was a significant factor for the presence of lunate cysts (odds ratio: 11.692, p < 0.001; odds ratio: 1.063, p < 0.001, respectively). However, positive ulnar variance or duration of symptom in Group II was not a predisposing factor for lunate cysts (odds ratio: 1.035, p = 0.598; odds ratio: 1.007, p = 0.877, respectively). CONCLUSION: Since positive ulnar variance or duration of symptom did not affect the formation of the lunate cyst and only slightly more than 50% (57.6%) of patients with UIS had a lunate cyst, it seems unlikely that these cysts are a pathognomonic finding. Surgeons can obtain some evidence from lunate cysts on radiographic exams, but care must be taken that this diagnosis is not made hastily or without due consideration.

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.

TREATMENT OF UNICAMERAL BONE CYSTS IN CHILDREN: A COMPARATIVE STUDY.

Unicameral bone cysts (UBC) are benign bone tumor-like lesions. Mostly they are located in the metaphyseal-diaphyseal region of long bones in children and adolescents. The etiology of UBC is still unclear. There is no consensus about the protocol of UBC treatment. The aim of this study was to evaluate the effectiveness of three different techniques for the treatment of UBC. This study included 129 pediatric patients with UBC treated at University Children's Hospital in Belgrade during the 8-year period. The mean follow up was 7.14 years. The following parameters were observed: gender, age, site, length of cyst, cyst index, cortical thickness, presentation of pathologic fracture, healing of cyst, treatment complications and length of hospitalization. These parameters were correlated to three treatment modalities, i.e. intracystic methylprednisolone acetate injection (group 1), curettage with bone grafting (group 2) and osteoinductive procedure using demineralized bone matrix (group 3). We found statistically significant differences in healing of the cysts and length of hospital treatment between groups 1 and 2, and between groups 2 and 3. In conclusion, complete healing of UBC can be achieved only using open surgery procedure. Intracystic methylprednisolone acetate instillation can be considered a good option for initial treatment of UBC.

Independent association of joint space narrowing, cyst formation and health-related quality of life of patients with hip osteoarthritis in Japan.

INTRODUCTION: This study clarified individual associations of joint space narrowing (JSN) and radiographic features (RF) of hip osteoarthritis (HOA), i.e., cyst and osteophyte formation and subchondral sclerosis, with quality of life (QOL) in Japanese HOA patients. METHODS: This cross-sectional study comprised 117 Japanese HOA patients (98 women, 17 men; mean age, 61.2 years). We recorded locations and the size of each RF and measured JSN on the acetabular side (Ace) or femoral head (FH). We evaluated pain with the Visual Analog Scale (VAS) and assessed QOL with the physical component summary (PCS) and mental component summary (MCS) of the Medical Outcomes Study Short Form-36. We compared QOL with/without the RF on the Ace, FH or both and analyzed relationships between each RF and VAS, PCS and MCS with linear regression analysis. We assessed independent associations of each RF with PCS and MCS with multiple regression analysis using various independent variables. RESULTS: VAS values with the cyst on the Ace only were significantly lower than those with the cyst at both locations. PCS values with the cyst on the Ace only were significantly higher than those for both locations. Independent associations existed for maximum cyst length on the Ace and FH with VAS and for JSN with PCS, but none existed for MCS. CONCLUSIONS: Our study suggested that the location and the size of the cyst formation were associated with both VAS and QOL in Japanese HOA patients. The JSN was independently associated with the PCS.

Acromegalic arthropathy in various stages of the disease: an MRI study.

BACKGROUND: Arthropathy is a prevalent and invalidating complication of acromegaly with a characteristic radiographic phenotype. We aimed to further characterize cartilage and bone abnormalities associated with acromegalic arthropathy using magnetic resonance imaging (MRI). METHODS: Twenty-six patients (23% women, mean age 56.8 ± 13.4 years), with active (n = 10) and controlled acromegaly (n = 16) underwent a 3.0 T MRI of the right knee. Osteophytes, cartilage defects, bone marrow lesions and subchondral cysts were assessed by the Knee Osteoarthritis Scoring System (KOSS) method. Cartilage thickness and cartilage T2 relaxation times, in which higher values reflect increased water content and/or structural changes, were measured. Twenty-five controls (52% women, mean age: 59.6 ± 8.0 years) with primary knee OA were included for comparison. RESULTS: Both in active and controlled acromegaly, structural OA defects were highly prevalent, with thickest cartilage and highest cartilage T2 relaxation times in the active patients. When compared to primary OA subjects, patients with acromegaly seem to have less cysts (12% vs 48%, P = 0.001) and bone marrow lesions (15% vs 80%, P = 0.006), but comparable prevalence of osteophytosis and cartilage defects. Patients with acromegaly had 31% thicker total joint cartilage (P < 0.001) with higher cartilage T2 relaxation times at all measured sites than primary OA subjects (P < 0.01). CONCLUSIONS: Patients with active acromegaly have a high prevalence of structural OA abnormalities in combination with thick joint cartilage. In addition, T2 relaxation times of cartilage are high in active patients, indicating unhealthy cartilage with increased water content, which is (partially) reversible by adequate treatment. Patients with acromegaly have a different distribution of structural OA abnormalities visualized by MRI than primary OA subjects, especially of cartilage defects.

Simple and aneurysmal bone cyst: Aspects of jaw pseudocysts based on an experience of Brazilian pathology service during 53 years

BACKGROUND: Jaw pseudocysts are benign osseous lesions of unclear etiology. Among these, the simple bone cyst (SBC) and aneurysmal bone cyst (ABC) are intriguing bone pathologies still rarely studied together. This retrospective study aimed to present the long-term case series of patients with jaw pseudocysts focusing on the clinical, radiographic, and transoperative aspects. MATERIAL AND METHODS: A retrospective case series of patients with SBC and ABC was performed. Clinical, radiographic, and transoperative aspects of both pseudocysts were reviewed from the histopathological archives of 20,469 cases between 1959-2012. All descriptive data were summarized. RESULTS: Of 354 (15.25%) bone pathologies, 54 cases of jaw pseudocysts were found, with 42 (11.86%) SBC and 12 (3.39%) ABC cases. For both lesions, most of the sample were young Caucasian women with an asymptomatic posterior mandible lesion with undetermined time of evolution and none trauma history. A unique radiolucent scalloped lesion presenting an empty cavity were also observed for both conditions. However, some atypical findings were found for SBC including: the expansion of bone cortical, tooth resorption, displacement of the mandibular canal, and recurrence. The absence of painful symptoms and the lack of classical blood-filled cavity were observed in some cases of ABC. CONCLUSIONS: The SBC and ABC are bone pathologies with few retrospective studies, no previous studies on the two conditions, varied nomenclature, and atypical aspects in some cases. Therefore, the knowledge of clinical, imaging, and transoperative features of such pseudocysts are clinically valuable as diagnosis hypothesis of radiolucent lesions of the jaws

Simple and aneurysmal bone cyst: Aspects of jaw pseudocysts based on an experience of Brazilian pathology service during 53 years.

BACKGROUND: Jaw pseudocysts are benign osseous lesions of unclear etiology. Among these, the simple bone cyst (SBC) and aneurysmal bone cyst (ABC) are intriguing bone pathologies still rarely studied together. This retrospective study aimed to present the long-term case series of patients with jaw pseudocysts focusing on the clinical, radiographic, and transoperative aspects. MATERIAL AND METHODS: A retrospective case series of patients with SBC and ABC was performed. Clinical, radiographic, and transoperative aspects of both pseudocysts were reviewed from the histopathological archives of 20,469 cases between 1959-2012. All descriptive data were summarized. RESULTS: Of 354 (15.25%) bone pathologies, 54 cases of jaw pseudocysts were found, with 42 (11.86%) SBC and 12 (3.39%) ABC cases. For both lesions, most of the sample were young Caucasian women with an asymptomatic posterior mandible lesion with undetermined time of evolution and none trauma history. A unique radiolucent scalloped lesion presenting an empty cavity were also observed for both conditions. However, some atypical findings were found for SBC including: the expansion of bone cortical, tooth resorption, displacement of the mandibular canal, and recurrence. The absence of painful symptoms and the lack of classical blood-filled cavity were observed in some cases of ABC. CONCLUSIONS: The SBC and ABC are bone pathologies with few retrospective studies, no previous studies on the two conditions, varied nomenclature, and atypical aspects in some cases. Therefore, the knowledge of clinical, imaging, and transoperative features of such pseudocysts are clinically valuable as diagnosis hypothesis of radiolucent lesions of the jaws.

[Interest of imaging in tumors benign bone in children]. / Intérêt de l'imagerie dans les tumeurs osseuses bénignes chez l'enfant.

Benign bone tumors are more common than malignant tumors in pediatrics. The exostosis (ostéchondrome) is the most common. The different imaging techniques are pivotal in the study of tumors including its standard radiography. The aim of this work is to highlight the interest in imaging the diagnostic management of bone benign tumors in children through a retrospective study of 169 patients. All patients were investigated by plain radiography, scanner supplement with multiplanar reconstruction before and after injection of PDC and / or MRI 1. 5 Tesla was performed according to the indication. The average age is 6 years with a slight male predominance. Clinically, the swelling is present in 35% of cases. The pain in 29% of cases. The most common location is the metaphyseal long bone on: Femur: 25% of cases, humerus: 17% of cases, Tibia: 21% of cases. Main Benign tumors are found exostosis (20. 12%), bone cyst (31. 95%) and osteoblastoma (16, 57%). The imagery is used to specify the topography and extension of the lesion in the bone provide arguments in favor of benign and sometimes in favor of the cause of the injury. The only standard radiograph often provides a diagnosis of certainty in some cases.

Magnetic Resonance Imaging Evidence of Postoperative Cyst Formation Does Not Appear to Affect Clinical Outcomes After Autologous Osteochondral Transplantation of the Talus.

PURPOSE: To identify potential cysts using magnetic resonance imaging (MRI) after autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus (OLTs) as well as to determine the effect of cysts on short-term clinical outcomes. METHODS: Eighty-nine MRI scans of 37 patients who had AOT for an OLT were evaluated. Radiographic variables examined included cyst presence, cyst location, bone edema, and cartilage integrity. Patient clinical variables recorded and examined for association with the presence of a cyst included gender, age, preoperative lesion size, size and number of osteochondral graft used, symptoms reported, and pre- and postoperative Foot and Ankle Outcome Score (FAOS) and Short Form-12 (SF-12) scores measured at final follow-up. RESULTS: Twenty-four patients (64.8%) had MRI evidence of cystic change after AOT for an OLT at a mean MRI follow-up time of 15 months after surgery (range 2-54). Patients with presence of a cyst after surgery were older (mean age, 42.7 years) than those without cysts (mean age, 32.7 years) (P = .041), and among patients with a cyst, older patients more often had involvement of the subchondral plate (57.3 v 36.7 years) (P < .001). No other variables associated with cyst formation had statistical significance. Mean patient FAOS scores increased from 50 (±19) preoperatively to 87 (±8) postoperatively. Mean SF-12 scores increased from 52 (±18) preoperatively to 85 (±6) postoperatively. Patients not identified as having a cyst had lower SF-12 (P = .028) and FAOS (P = .032) preoperative scores and more improvement in SF-12 (P = .006) and FAOS (P = .016) scores than patients with cysts. CONCLUSIONS: Postoperative cyst formation on MRI was found to be a common occurrence after AOT for OLT. Although increasing age was related to increased cyst prevalence, the clinical impact of cyst formation was not found to be significant at short-term follow-up. Continued long-term longitudinal follow-up of postoperative cysts is needed. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Intravertebral pneumatocysts of the cervical spine.

INTRODUCTION: The aim of this study was to investigate the prevalence of intravertebral pneumatocyst (IVP) of the cervical spine by age group, compared with that of intradiscal vacuum (IDV). METHODS: We investigated 500 consecutive patients who underwent cervical computed tomography (CT) from May 2012 to May 2013 for various indications. CT datasets were assessed for the presence of IVPs and IDVs with stratification by age. RESULTS: IVPs of the cervical spine were detected in 8 % (7 of 86 subjects) of patients in their forties or below, 30 % (23 of 75) in their fifties, 49 % (67 of 136) in their sixties, 55 % (76 of 137) in their seventies, and 60 % (40 of 66) in their eighties or over. IDVs of the cervical spine were detected in 6, 25, 48, 54, and 57 %, respectively. Coexistence of both phenomena was identified in 4, 17, 33, 40, and 43 %, respectively. CONCLUSION: IVPs of the cervical spine are a common incidental finding, increasing in prevalence with age and more common than IDV in all age groups.

Clinical characteristics of intraspinal facet cysts following microsurgical bilateral decompression via a unilateral approach for treatment of degenerative lumbar disease.

PURPOSE: Primary intraspinal facet cysts in the lumbar spine are uncommon, but it is unclear whether cyst incidence increases following decompression surgery and if these cysts negatively impact clinical outcome. We examined the prevalence, clinical characteristics, and the risk factors associated with intraspinal facet cysts after microsurgical bilateral decompression via a unilateral approach (MBDU). METHODS: We studied 230 patients treated using MBDU for lumbar degenerative disease (133 men and 97 women; mean age 70.3 years). Clinical status, as assessed by the Japanese Orthopedic Association (JOA) score and findings on X-ray and magnetic resonance images, was evaluated prior to surgery and at both 3 months and 1 year after surgery. The prevalence of intraspinal facet cysts was determined and preoperative risk factors were defined by comparing presurgical findings with clinical outcomes. RESULTS: Thirty-eight patients (16.5%) developed intraspinal facet cysts within 1 year postoperatively, and 24 exhibited cysts within 3 months. In 10 patients, the cysts resolved spontaneously 1 year postoperatively. In total, 28 patients (12.2%) had facet cysts 1 year postoperatively. The mean JOA score of patients with cysts 1 year postoperatively was significantly lower than that of patients without cysts. This poor clinical outcome resulted from low back pain that was not improved by conservative treatment. Most cases with spontaneous cyst disappearance were symptom-free 1 year later. The preoperative risk factors for postoperative intraspinal facet cyst formation were instability (OR 2.47, P = 0.26), scoliotic disc wedging (OR 2.23, P = 0.048), and sagittal imbalance (OR 2.22, P = 0.045). CONCLUSIONS: Postoperative intraspinal facet cyst formation is a common cause of poor clinical outcome in patients treated using MBDU.

Symptomatic sacroiliac joint disease and radiographic evidence of femoroacetabular impingement.

Symptomatic sacroiliac (SI) joint disease is poorly understood. The literature provides no clear aetiology for SI joint pathology, making evaluation and diagnosis challenging. We hypothesised that patients with documented sacroiliac pain might provide insight into the aetiology of these symptoms. Specifically, we questioned whether SI joint symptoms might be associated with abnormal hip radiographs. We reviewed the pelvic and hip radiographs of a prospectively collected cohort of 30 consecutive patients with SI joint pathology. This database included 33 hips from 30 patients. Radiographic analysis included measurements of the lateral centre edge angle, Tönnis angle, and the triangular index, of the ipsilateral hip. Evidence for retrotorsion of the hemipelvis was recorded. Hips were graded on the Tönnis grading system for hip arthrosis. In this cohort 14/33 (42%) of hips had evidence of significant osteoarthrosis indicated by Tönnis grade 2 or greater and 15/33 (45%) displayed subchondral cyst formation around the hip or head neck junction. In assessing acetabular anatomy, 21% (7/33) had retroversion, 12% (4/33) had a lateral centre edge angle >40° with 3% (1/33) >45°. Tönnis angle was <0° in 27% (9/33). Coxa profunda and acetabuli protrusio were present in 47% (17/33) and 3% (1/33), respectively. When femoral head morphology was assessed, 33% (11/33) showed evidence of cam impingement. Overall, 76% (25/33) had at least one abnormality on their hip radiograph. A significant number of patients meeting strict diagnostic criteria for SI joint pain had radiographic evidence of femoroacetabular impingement (FAI) and hip arthrosis. The clinician should maintain FAI in the differential diagnosis when investigating patients with buttock pain.

Randomized controlled trial of osteoconductive fixation screws for anterior cruciate ligament reconstruction: a comparison of the Calaxo and Milagro screws.

PURPOSE: To compare the outcome of 2 bioabsorbable screws for tibial interference fixation in anterior cruciate ligament reconstruction with reference to rate of absorption, osteoconductive properties, and clinical outcome. METHODS: Patients undergoing primary anterior cruciate ligament reconstruction with hamstring autograft in a single unit were invited to participate in this study. Patients were randomized to receive either the Calaxo screw (Smith & Nephew, Andover, MA) or Milagro screw (DePuy Mitek, Raynham, MA) for tibial fixation. Patients were reviewed with subjective and objective evaluation by use of the International Knee Documentation Committee form, Lysholm score, KT-1000 arthrometry (MEDmetric, San Diego, CA), and clinical examination. Magnetic resonance imaging was performed at 1 year and computed tomography scanning at 1 week and at 6, 12, and 24 months. RESULTS: Sixty patients agreed to participate in the study, with 32 patients randomized to the Calaxo screw and 28 to the Milagro screw for tibial fixation. There was no significant difference in subjective or objective clinical outcome between the 2 groups. At 24 months, 88% of Calaxo screws showed complete screw resorption compared with 0% of Milagro screws (P < .001). Tibial cysts were present in 88% of the Calaxo group and 7% of the Milagro group (P = .001). At 24 months, the mean volume of new bone formation for the Calaxo group was 21% of original screw volume. Ossification of the Milagro screw was unable to be accurately assessed as a result of incomplete screw resorption. CONCLUSIONS: Both screws showed similar favorable objective and subjective outcomes at 2 years. The Calaxo screw resorbed completely over a period of 6 months and was associated with a high incidence of intra-tunnel cyst formation. The Milagro screw increased in volume over a period of 6 months, followed by a gradual resorption, which was still ongoing at 2 years. Both screws were associated with tunnel widening, and neither showed evidence of significant tunnel ossification. We conclude that, despite satisfactory clinical outcomes, the addition of "osteoconductive" materials to bioabsorbable screws is not associated with bone formation at the screw site at 2 years. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Premature cystic lesions in shoulders of elite junior javelin and volleyball athletes: a comparative evaluation using 3.0 Tesla MRI.

BACKGROUND: The purpose of this study was to evaluate clinical and magnetic resonance imaging (MRI) findings in the shoulders of high performance competitive junior javelin athletes and volleyball players. The hypothesis was that structural lesions already exist in young and asymptomatic overhead athletes. METHODS: Thirty-one healthy high performance junior elite athletes were included. Group 1 consisted of 15 male javelin throwers (mean age, 17.7 ± 0.8 years) and group 2 of 16 male volleyball players (16.9 ± 1.0 years). Questionnaire-based interviews, comprehensive clinical examination, and shoulder scoring systems (visual analog scale [VAS] and Constant-Murley Score) were completed. Bilateral shoulder imaging was performed using a 3.0 Tesla MRI. RESULTS: The Constant-Murley Score of group 1 was 95.5 ± 3.6 and 94.7 ± 4.6 points for group 2. Group 1 demonstrated a mean VAS of 0.9 ± 1.6 and group 2 a mean of 0.6 ± 0.8 points. Postero-superior intraosseous cysts of the humeral head were detected in 73.3% of all javelin throwers in the dominant shoulder, but only in 13.3% in the nondominant shoulder (P = .008). In the volleyball group, such cyst formation was rarely seen in 12.5% in the dominant versus 6.3% in the nondominant shoulder (P = .66). CONCLUSION: A high percentage of junior elite athletes already demonstrate osseus signs of overloading especially in the group of javelin athletes, although none had a history of prior shoulder pathology. Therefore, junior overhead athletes might be at risk for the early development of structural lesions at the insertion of the posterior rotator cuff similar to lesions already known for adult athletes, even though they do not present clinical signs of overuse at that age.

Treatment of facet cysts associated with neurogenic intermittent claudication with x-stop.

BACKGROUND: Facet degeneration often leads to the formation of synovial facet cysts. As facet cysts invade the spinal canal, they become a contributing factor to spinal stenosis. Previous studies have demonstrated successful treatment of neurogenic intermittent claudication (NIC), a major symptom of spinal stenosis, with an interspinous process device. PURPOSE: To compare clinical outcomes of patients with and without synovial facet cysts treated with an interspinous process device. STUDY DESIGN: Retrospective review of prospective data of consecutive patients undergoing the X-Stop procedure at an institution. OUTCOME MEASURES: Visual Analog Scale; Oswestry Disability Index; sitting, standing, and walking tolerances; and satisfaction survey. METHODS: Review of all patients from 2006 to 2010 undergoing X-Stop procedure at an institution. Imaging studies were used to identify the presence and measure the size of the facet cysts in 285 patients with a minimum of 6-month follow-up. Comparative clinical outcomes determined if X-Stop is a successful treatment option for patients with NIC in conjunction with synovial facet cysts (<3 mm, ≥3 mm). RESULTS: Fifty-eight of 285 patients (20.4%) were determined to have a synovial cyst as a contributing component of spinal stenosis. Twelve of 58 patients were noted to have a cyst ≥3 mm. The mean follow-up time for patients with and without a facet cyst was 21 months (6-55±12 mo) and 22 months (6-61±12 mo), respectively. The age of the patient at the time of the operation with and without facet cysts was 73 (±10 y). Patients without synovial cysts, with synovial cysts, and cysts ≥3 mm had an average change in Oswestry Disability Index of 15.6, 15.8, and 16.2, respectively. Visual Analog Scale scores were 2.3, 1.8, and 2.3, respectively. In addition, on satisfaction surveys 72.4%, 82.0%, and 77.8% were either very or somewhat satisfied, respectively. Overall complications included 4 spinous process fracture, 4 hematomas, 1 wound infection, and 1 implant migration. CONCLUSIONS: No statistical difference was noted in any of the outcome measures among patients with small facet cysts, large facet cysts, or without facet cysts when treated with an interspinous process device. We can thus conclude that X-Stop is an appropriate treatment consideration for NIC with or without the presence of synovial facet cysts.

Limb shortening in the course of solitary bone cyst treatment--a comparative study.

OBJECTIVE: The aim of this paper is to evaluate the frequency of limb shortening in the course of solitary bone cyst treatment. The correlation between the mode of treatment as well as the occurrence of pathological fracture, cyst location, volume, and locularity were examined. MATERIALS AND METHODS: A retrospective analysis was carried out on 135 patients where 80 underwent curettage and bone grafting and 55 were administered methylprednisolone injection with a mean time to follow-up of 12 years. RESULTS: Based on clinical and radiological evaluation, limb shortening was found in ten patients when the data before and after treatment was compared. Limb shortening ranging from 1 to 5 cm during the course of the treatment was observed: six in humerus, two in femur, two in tibia. Those with epiphyseal changes, magnetic resonance imaging to evaluate the degree of growth plate damage was performed. Patients with and without limb shortening did not differ statistically regarding the applied method of treatment. The cyst volume was significantly larger in the group of patients with limb shortening when compared to the group of patients with no limb shortening. CONCLUSIONS: In patients treated with curettage and bone grafting, the mode of treatment does not increase the frequency of occurrence of iatrogenic limb shortening. In patients with limb shortening, a statistically significant larger volume of the cyst was observed.

Predictive factors for recurrence of simple bone cyst of the proximal humerus.

PURPOSE: To evaluate factors predictive of recurrence following curettage of simple bone cysts (SBCs) in the proximal humerus. METHODS: Records of 29 male and 3 female patients aged 3 to 22 (mean, 11) years who underwent curettage with or without bone grafting for a solitary SBC in the proximal humerus were reviewed. The appearance, size, location, activity level, and fracture pattern of each cyst were recorded. The cyst index indicated the risk of refracture. Recurrence was defined as a refracture or enlargement of the cyst. RESULTS: 31 patients presented with a pathological fracture. The main symptoms were pain (n=30), loss of function (n=22), and mass/swelling (n=15). 25 patients gave a history of trauma. The duration of symptoms was less than one month. 10 patients had recurrence after a mean of 10 (range, 4-27) months; 5 were refractures and another 5 were enlargement of the cysts. Six were treated conservatively and eventually healed, whereas 4 underwent further curettage. Factors predictive of recurrence were patient age 5 years or younger (p=0.014), right-sided cyst (p=0.01), larger cyst (p=0.039), multilocular cyst (p=0.004) and unimpacted fracture (p=0.04). Recurrence was not related to gender, cyst location, or cyst activity level. CONCLUSION: Most SBCs heal even if the fracture is treated expectantly. SBCs should be left alone unless symptomatic. If curettage is performed, grafts or bone substitutes should be used. More aggressive treatment might be necessary for unimpacted fractures to minimise the risk of recurrence.

Bone cement in the management of cystic tumour defects of bone at National Orthopaedic Hospital, Igbobi, Lagos.

BACKGROUND: Cystic bony defects are characteristics of bone tumours especially benign ones e.g. Giant cell tumours of bone [GCT] and some metastatic tumours to bone. These patients present late with significant cystic cavities at a time the cost and availability of prosthetic implants to replace these defects sometimes precludes resection. The objective of this study is to evaluate the outcome of filling these defects with bone cement augmented with plate and screw for stability. METHOD: A seven year prospective study was carried out in patients presenting with large cystic bony defects secondary to bone tumours at the oncology unit of the National Orthopaedic Hospital, Igbobi, Lagos. Data such as age, sex, anatomic location of lesions, histological type of tumours, x-ray findings, operation performed with the number of packets of bone cement used to fill the resultant bony defects were retrieved from prepared proforma. The average follow-up was 36 months. RESULT: The proximal tibia and distal femur accounted for 42.9% and 28.6% respectively of the 14 patients studied. Giant cell tumour was the most common histological diagnosis 78.6%. Bone cement was effective in meeting the local requirements of limb salvage, early functional recovery and as a temporising measure until the patients can avail themselves of better options. The complication encountered was that of anaphylactic reaction in 2 scrub nurses. CONCLUSION: Bone cement augmented with appropriate implants has proven valuable as a stop gap in filling large cystic bony defects resulting from tumours.

Prevalence and MRI-anatomic correlation of bone cysts in osteoarthritic knees.

OBJECTIVE: The objectives of this study were to determine the prevalence of cysts in the weight-bearing areas and interspinous bone cysts in tibial plateau specimens derived from knees with advanced osteoarthritis, to perform MRI-anatomic correlation of these cysts, and to define their histologic characteristics. MATERIALS AND METHODS: Forty-two tibial plateau specimens were recovered from patients undergoing total knee replacement surgery for severe osteoarthritis (14 men and 28 women; mean age, 74 years; age range, 58-87 years). The tibial specimens underwent MRI with T1- and T2-weighted MR sequences. No radiographic data were available before MRI. Tibial specimens were sectioned using a high-speed rotating diamond disk into 3-mm-thick slices. MR images and anatomic specimens were analyzed for the presence of cysts in the interspinous and weight-bearing areas. Histologic staining methods included routine Harris hematoxylin stain, trichrome stain, and Alcian blue-PAS stain. RESULTS: Twenty-three (54%) of 42 specimens contained one or more cystic areas, with a total of 30 cystic areas. The cysts were distributed in the weight-bearing area (14/30) and interspinous area (16/30). All cysts seen on the anatomic slices could also be depicted on both MRI sequences. Histologic findings were identical for all noncommunicating cysts and revealed necrotic bone fragments with dead denuclearized cells. The cavities were surrounded by a layer of fibrous connective tissue containing adipocytes and osteoblasts. No evidence of epithelial components was found in the lining of the cavities. CONCLUSION: Interspinous and weight-bearing tibial cysts are common in severe knee osteoarthritis. The cysts contain necrotic bone fragments and are lined by a nonepithelial fibrous wall. Our findings support the hypothesis that interspinous cysts could result from repetitive bone stresses through the cruciate ligaments. Our findings do not support the use of the term "herniation cyst."