Relationship between DXA measured systemic bone mineral density and subchondral bone cysts in postmenopausal female patients with knee osteoarthritis: a cross-sectional study : Osteoarthritis cysts and bone mineral density.

BACKGROUND: Individuals with high systemic bone mineral density (BMD) may have an increased risk of incident knee osteoarthritis (OA). Besides that, radiographic osteophytes are strongly associated with BMD. Because of these reasons, the aim of the study was to investigate the possible association between radiological subchondral bone cyst (SBC) grade and systemic BMD and vitamin D status in the postmenopausal female patients with knee OA in a crosss-sectional study. METHODS: This study included of 48 osteoporosis treatment-free postmenopausal patients diagnosed with symptomatic medial compartment knee OA. BMD analysis was performed using dual-energy X-ray absorptiometry (DXA) and serum vitamin D levels were measured after recording patients' findings. Each knee was scanned using computed tomography (CT), and categorical SBC scores were graded for the medial and lateral tibiofemoral (TF) and patellofemoral (PF) compartments and further calculated as compartmental total, total TF and grand total of both TF compartments. SBC scores were analysed with correlation analysis. RESULTS: The patient population was characterized by radiographic joint space narrowing, obesity and low vitamin D status. Median medial total and grand total TF SBC scores were significantly different between the patient groups according to the Kellgren-Lawrence (KL) radiographic grading (p = 0.006 and p = 0.007, respectively). There were no correlations between femoral BMD values and SBC scores. However, positive correlations were detected significantly between L1 - 4 DXA values and TF SBC scores, but not with PF SBC scores (p = 0.005 for the correlation between L1 - 4 BMD and medial compartments total TF SBC score, p = 0.021 for the correlation between L1 - 4 BMD and grand total TF SBC score). No significant correlations were found with Vitamin D levels. CONCLUSIONS: Development of TF OA high-grade SBCs may be linked to systemic bone mass as represented by trabecular bone-rich lumbar vertebrae. The relationship might point to the importance of bone stiffness as an acting factor in knee OA possibly with mechanical energy transfer to the joint.

Pathological fracture increases the risk of unsatisfactory functional results and avascular necrosis in children with proximal femur simple bone cysts.

INTRODUCTION: Proximal femur simple bone cysts (SBCs) are rare in children, but with a risk of pathological fractures and the associated poor outcomes. This study aimed to evaluate the functional and radiographic outcomes of children with proximal femur SBCs. PATIENTS AND METHODS: 38 children with proximal femur SBCs treated surgically at our department, West China hospital, were enrolled in the study. Patients were divided into two groups according to whether pathological fractures presented before treatment. The non-fracture group received treatment of open curettage, cavity electrocauterization, bone grafting, and fixation (proximal femoral plate, intramedullary nail or Kirschner wire). The pathological fracture group received the same procedures of curettage, electrocauterization, grafting, and fixation. Autogenous iliac bone grafting was done in all cases, and the artificial bone was used as a supplementary based on the size of the cavity. Postoperatively, all patients underwent hip spica or similar orthosis immobilization for six weeks and received the same rehabilitation program after the removal of hip spica. Patients were evaluated by two independent observers, including the functional results based on the Ratliff's criteria, avascular necrosis, healing rate based on the Neer scoring system, coxa vara, and premature physeal arrest. We described the good outcome in Ratliff's criteria as "Satisfactory results", and fair and poor outcomes as "Unsatisfactory results." Grade 1 and grade 2 Neer results were termed as failures in treatment, and grades 3 and 4 were considered successes and healing. RESULTS: 38 patients with 38 hips (18 on the left side and 20 on the right side) were evaluated, including 9 females and 29 males, with a mean age of 9.0±2.6 years old (range, 5 to 14 years). There was no significant difference between these two groups in the baseline data of gender, age, side, grafting, staging, and fixation methods. The rate of unsatisfactory functional results in the pathological fractures group was 56.3% (9/16), significantly higher than that in patients without fracture (22.7%, 5/22. p= 0.047). There was also a significant difference in avascular necrosis of the femoral head between the pathological fractures group (7/16) and the group without fracture (2/22, p=0.021). Thirty cases presented with healing, including 13 in the fractures group and 17 in the non-fracture group (p=1.000), and eight cases were graded as failures (2 cases of grade 1 and 6 cases of grade 2). There were also no significant differences between these two groups in premature physeal arrest (2 in fracture group and 1 in non-fracture group, P=0.562), and Coxa vara (3 in the fracture group and 0 in non-fracture group, P=0.066). CONCLUSIONS: Pathological fracture significantly increases the risk of unsatisfactory functional results and avascular necrosis of the femoral head in patients with femoral neck SBCs. Prophylactic treatment and fixation of SBCs in weight bearing proximal femur region is better to manage without complications than managing with pathological fractures.

Long-Term Outcomes of Decompression and Grafting in Acute Pathological Proximal Femur Fractures in Children with Unicameral Bone Cysts: A Retrospective Study Utilizing a 120° Fixed-Angle Low-Contact Locking Pediatric Hip Plate.

BACKGROUND Unicameral bone cysts (UBCs) are benign tumor-like lesions that are the most common cause of pathological proximal femur fracture in children. This study aimed to present the outcomes of acute, unstable, pathological proximal femur fractures secondary to UBCs in children. MATERIAL AND METHODS We retrospectively reviewed data on 12 patients with a mean age of 9.3 years (7-12 years) who were initially treated with decompression and grafting, followed by stabilization using a 120° fixed-angle low-contact locking pediatric plate (LCLPP). The Musculoskeletal Tumor Society (MSTS) scores, Capanna classification of cyst repair, time to union, collodiaphyseal angle (CDA), and limb length discrepancy (LLD) were evaluated. RESULTS The mean follow-up was 33.1 months (range, 13-96 months). The mean union time was 9.5 weeks (8-14 weeks). The mean time for reparation of the cyst was 6.9 months (range 3-9 months). Four patients had Dormans type IB, while the remaining had type IIB fractures. According to the Capanna classification, repairs in 10 cases were grade I and in 2 cases grade II. At the last follow-up, the mean 120.8° of preoperative CDA was corrected to 140.9° (P<0.001) and there was no difference compared to the healthy side (P=0.214). The mean postoperative MSTS score was 97.1% (29.1 points). Two patients experienced LLD at the affected extremities, while the other 10 patients healed without any complications. CONCLUSIONS Fixation of acute unstable fractures secondary to UBCs with a 120° fixed-angle LCLPP is a reliable and successful option after decompression and grafting of the lesion.

Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis.

BACKGROUND: Subchondral bone cysts (SBCs) of the talus are frequently observed in ankle osteoarthritis (OA). It is unclear whether the cysts need direct treatment after correction of the varus deformity in ankle OA. The purpose of this study is to investigate the incidence of SBCs and the change after supramalleolar osteotomy (SMOT). METHODS: Thirty-one patients treated by SMOT were retrospectively reviewed, and 11 ankles had cysts preoperatively. After SMOT without management of the cysts, the evolution of cysts was evaluated on weightbearing computerized tomography (WBCT). The American Orthopaedic Foot and Ankle Society (AOFAS) clinical ankle-hindfoot scale and a visual analog scale (VAS) were compared. RESULTS: At baseline, the average cyst volume was 65.86 ± 60.53 mm3. The number and volume of cysts were reduced dramatically (P＜.05), and the cysts vanished in 6 ankles after the SMOT. The VAS and AOFAS scores improved significantly after SMOT (P＜.001), there was no significant difference between ankles with cysts and without cysts. CONCLUSIONS: The SMOT alone without direct treatment of the SBCs led to a decrease in the number and volume of SBCs in varus ankle OA. LEVEL OF EVIDENCE: Level IV, case series.

Concomitant Subchondral Bone Cysts Negatively Affect Clinical Outcomes Following Arthroscopic Bone Marrow Stimulation for Osteochondral Lesions of the Talus.

PURPOSE: To study the effects of concomitant subchondral bone cysts (SBCs) on prognosis after arthroscopic bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLTs) less than 100 mm2 and to further assess the correlation between cystic OLT area, depth, or volume and postoperative outcomes. METHODS: We retrospectively analyzed consecutive patients with OLTs (<100 mm2) who received BMS between April 2017 and May 2020 with a minimum follow-up of 24 months. Lesion area, depth, and volume were collected on preoperative magnetic resonance imaging. Visual analog scale (VAS), American Orthopedic Foot and Ankle Society, Karlsson-Peterson, Tegner, Foot and Ankle Ability Measure (FAAM)-Activities of Daily Life and Sports scores were assessed before surgery and at the latest follow-up. Additionally, a general linear model (GLM) and a Pearson correlation analysis (PCA) were performed to investigate the effects of concomitant cysts on postoperative results. RESULTS: Eighty-two patients with a mean follow-up of 39.22 ± 12.53 months were divided into non-cyst (n = 45; 39.91 ± 13.03 months) and cyst (n = 37; 38.37 ± 12.02 months) groups. There was no significant difference in the OLT area between the non-cyst and cyst groups (46.98 ± 19.95 mm2 vs 56.08 ± 22.92 mm2; P = .093), but the cyst group showed significantly greater depth (6.06 ± 1.99 mm vs 3.96 ± 1.44 mm; P = .000) and volume (248.26 ± 156.81 mm3 vs 134.58 ± 89.68 mm3; P = .002). The non-cyst group showed significantly more improvement in VAS pain, Karlsson-Peterson, Tegner, and FAAM scores than the cyst group (P < .05). The GLM indicated that SBCs negatively affected VAS pain and Tegner scores (P < .05). For OLTs with cysts, the PCA showed that an area of 90.91 mm2, depth of 7.56 mm, and volume of 428.13 mm3 were potential cutoff values associated with poor outcomes. CONCLUSIONS: The concomitant SBCs negatively affected the prognosis of OLTs after BMS. For OLTs with cysts, an area of 90.91 mm2, depth of 7.56 mm, and volume of 428.13 mm3 were the potential cutoff values associated with poor outcomes after BMS. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Treatments and Sequelae of Pediatric Pathologic Proximal Femur Fractures Due to Benign Bone Cyst.

BACKGROUND: The proximal femur is a common location for pathologic fractures in children, yet there is little published information regarding this injury. The purpose of this study was to investigate the outcomes of pediatric pathologic proximal femur fractures due to benign bone tumors. METHODS: A retrospective review of patients treated for pathologic proximal femur fractures from 2004 to 2018 was conducted. Inclusion criteria were age below 18 years and pathologic proximal femur fracture secondary to a benign bone tumor. Patients were excluded if they had <1 year of follow-up. Medical charts and serial radiographs were reviewed for fracture classification, underlying pathology, treatment, complications, and time to fracture healing. RESULTS: A total of 14 patients were included. Mean age was 6±3 (3 to 11) years, and mean follow-up was 44±21 (22 to 86) months. Index treatment was spica casting in 9/14 (68%) patients, while 5/14 (32%) were treated with internal fixation. Of the 9 patients initially treated with casting, 22% (2/9) required repeat spica casting at a mean of 0.6 months after index treatment, 67% (6/9) required internal fixation at a mean of 20.3 months after index treatment, and 11% (1/9) did not require revision treatment. Eighty-eight percent (8/9) of patients treated with casting required revision treatment compared with 40% (2/5) of those treated with internal fixation (P=0.05). Nonunion occurred after 1 refracture, malunion with coxa vara occurred in 2 fractures, and the remaining 11/14 (84%) fractures had a union at a mean of 4.9±3.0 months All cases of malunion occurred in patients initially treated nonoperatively. There were 19 distinct complications in 10/14 (71%) patients. The incidence of any revision surgery was 64% (9/14). CONCLUSIONS: In this series, pediatric pathologic proximal femur fractures demonstrated prolonged time to union, high incidence of revision surgery (64%), and substantial complication rate (71%). In children with pathologic proximal femur fractures, treatment with internal fixation is recommended as this series showed a 78% failure rate of initial conservative management. LEVEL OF EVIDENCE: Level IV.

Berardinelli Seip Syndrome: A rare case report.

Berardinelli Seip Congenital Lipodystrophy (BSCL) or Congenital Generalized Lipodystrophy (CGL) is one of the four subgroups of lipodystrophy syndrome which is characterized by varying degrees of loss of adipose mass in the body. It is an extremely rare autosomal recessive disorder and commonly reported clinical presentations include muscular hypertrophy, gigantism, hepatomegaly, impaired glucose tolerance, acanthosis nigricans, hypertriglyceridaemia, cardiomyopathy, intellectual impairment, bone cysts and phlebomegaly. We present a case of a 4.5 years old male child born to consanguineous parents, presented with pneumonia. There was history of recurrent diarrhea and chest infection in the past. He had acromegaly like features, hirsutism, firm hepatomegaly, a well defined bone cyst in proximal right femur, pancytopenias with normal bone marrow biopsy report, hypertriglyceridemia and selective IgA deficiency. This is the first case of BSCL, reported in Pakistan with a bone cyst and IgA deficiency. Such patients need to be identified and monitored for complications like diabetes mellitus and hypertrophic cardiomyopathy.

Imaging Findings of Calcaneal Cyst and Lipoma: Can Intraosseous Cyst Changes Into Lipoma With Advancing Age?

OBJECTIVE: Recent studies have indicated that intraosseous lipomas originate from simple bone cysts of the calcaneus. This study evaluates computed tomography (CT) and magnetic resonance imaging (MRI) findings of calcaneal cysts and lipomas in pediatric and adult populations. METHODS: Forty-six patients with bone lesions located in the anterior portion of the calcaneus beneath the talocalcaneal joint, who underwent CT and/or MRI, were enrolled in this study. The imaging characteristics were retrospectively reviewed and compared between the pediatric (aged 18 years or younger; n = 29) and adult (aged 19 years or older; n = 17) groups. RESULTS: On CT images, water/soft tissue attenuation alone was more frequent in the pediatric group than in the adult group (84% vs 13%, respectively; P < 0.01), whereas the combined water/soft tissue and fat attenuation (11% vs 47%, respectively; P < 0.05) and fat attenuation alone (5% vs 40%, respectively; P < 0.05) were less frequent in the pediatric group than in the adult group. On MRI, cystic components alone were more frequent in the pediatric group than in the adult group (88% vs 13%, respectively; P < 0.01), whereas the combined cystic and fat components (8% vs 38%, respectively; P < 0.05) and fat components alone (4% vs 50%, respectively; P < 0.01) were less frequent in the pediatric group than in the adult group. CONCLUSIONS: Calcaneal cysts were more frequent in the pediatric group, whereas calcaneal lipomas were more frequent in the adult group. These results could be additional evidence that intraosseous lipomas originate from simple bone cysts of the calcaneus.

Magnetic Resonance Imaging-Assessed Subchondral Cysts and Incident Knee Pain and Knee Osteoarthritis: Data From the Multicenter Osteoarthritis Study.

OBJECTIVE: To examine whether knee subchondral cysts, measured on magnetic resonance imaging (MRI), are associated with incident knee osteoarthritis (OA) outcomes. METHODS: We used longitudinal data from the Multicenter Osteoarthritis Study, a community-based cohort of subjects with risk factors for knee OA. Participants without a history of knee surgery and/or inflammatory arthritis (i.e., rheumatoid arthritis and gout) were followed up for 84 months for the following incident outcomes: 1) radiographic knee OA (Kellgren/Lawrence grade ≥2), 2) symptomatic radiographic knee OA (radiographic knee OA and frequent knee pain), and 3) frequent knee pain (with or without radiographic knee OA). In a subset of participants, subchondral cysts were scored on baseline MRIs of 1 knee. Multiple logistic regression, with adjustment for participant characteristics and other baseline knee MRI findings, was used to assess whether subchondral cysts were predictive of incident outcomes. RESULTS: Among the participants with knees eligible for analyses of outcomes over 84 months, incident radiographic knee OA occurred in 22.8% of knees with no baseline radiographic knee OA, symptomatic radiographic knee OA occurred in 17.0% of knees with no baseline symptomatic radiographic knee OA, and frequent knee pain (with or without radiographic knee OA) occurred in 28.8% of knees with no baseline radiographic knee OA and 43.7% of knees with baseline radiographic knee OA. With adjustment for age, sex, and body mass index, the presence of subchondral cysts was not associated with incident radiographic knee OA but was associated with increased odds of incident symptomatic radiographic knee OA (odds ratio 1.92 [95% confidence interval 1.16-3.19]) and increased odds of incident frequent knee pain in those who had radiographic knee OA at baseline (odds ratio 2.11 [95% confidence interval 0.87-5.12]). Stronger and significant associations were observed for outcomes based on consistent reports of frequent knee pain within ~1 month of the study visit. CONCLUSION: Subchondral cysts are likely to be a secondary phenomenon, rather than a primary trigger, of radiographic knee OA, and may predict symptoms in knees with existing disease.

Are Fibular Allograft Struts Useful for Unicameral Bone Cysts of the Proximal Humerus in Skeletally Mature Patients?

BACKGROUND: Although most unicameral bone cysts (UBCs) are either successfully treated or have healed by the time of skeletal maturity, a small proportion of patients will have persistent UBCs beyond the age of skeletal maturity. More reliable methods are needed to treat persistent UBCs in the humerus because these cysts are associated with a high risk of fracture due to thinning of the humeral cortex. In this study, we evaluated whether inserting a fibular strut allograft into the humerus would be associated with healing of the cyst and union of associated pathologic fractures in skeletally mature patients with a UBC of the proximal humerus. QUESTIONS/PURPOSES: (1) How effective is inserting a fibular strut allograft in the healing of proximal humerus UBCs in skeletally mature patients with bone cysts and associated fractures? (2) What are the functional results of this procedure? (3) What complications are associated with this procedure? METHODS: Between 2005 and 2018, we surgically treated 23 skeletally mature patients with persistent humeral UBCs and any of the following indications: a progressive cyst that was not responsive to aspiration and 2 to 3 steroid injections, a cyst with a pathologic fracture, and a cyst at high risk of fracture. Of those, patients with a cyst located in the proximal humerus and a defect length more than 6 cm (n = 18) were considered eligible to be treated with insertion of a fibular strut allograft through a hole created in the greater tuberosity. A further two patients were excluded because they were treated by other surgical methods. From the remaining 16 patients, two patients were lost to follow-up before 2 years and could not be analyzed in this study. Another two patients had incomplete datasets, leaving 12 for analyses in this retrospective study. Three patients presented with a pathologic fracture. Complete filling of the cysts with bone within 24 months was regarded as healing, and after 24 months it was classified as delayed healing. Cyst consolidation with small residual areas of osteolysis was considered healed with residual radiographic appearance. Fracture union was determined by the clear observation of at least three of four cortical views bridged by bone in the radiographic follow-up 3 months after the operation. Fractures in which the cortices were not bridged by bone after 3 months were regarded as a delayed union. The functional outcome of the patients was assessed by the Musculoskeletal Tumor Society (MSTS) scoring system, with a total score ranging from 0 to 30. A higher score was indicative of less pain and better function. MSTS scores were obtained through a chart review by an orthopaedist who was not involved in the care administered. RESULTS: At a median (range) follow-up of 57 months (33 to 87), the cyst was completely healed in nine patients and healed with residual cyst in the remaining three. Union was observed within 3 months in all patients who presented with a pathologic fracture. The median MSTS score of the patients was 30 (28 to 30). No postoperative complications such as persistent pain or re-fracture were observed. CONCLUSION: The primary goal of treating a UBC of the proximal humerus is to prevent fracture of the affected bone; insertion of a fibular strut graft in this study met this goal. Therefore, we believe a fibular strut allograft insertion is worth consideration when treating proximal humeral UBCs in skeletally mature patients. Further studies will be needed to determine whether this approach has benefits compared with other treatment options. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Evaluation of different treatment modalities for fractured and non-fractured simple bone cyst: A single-center review of 68 patients.

ABSTRACT: Simple bone cysts (SBCs) occur most frequently in the proximal aspect of the humerus and femur in growing age and are associated with intercurrent pathological fractures in up to 87%. Therapeutic management of SBCs remains controversial. The aim of this study was to examine the outcome of conservative and various surgical treatment modalities considering the specific anatomic location and integrity of the SBC.In this retrospective study, we analyzed 68 cases of SBCs who underwent a conservative or surgical treatment between 2009 and 2020 with a mean follow-up of 30.1 months. The epidemiological characteristics, complications, clinical, and radiographic outcome after conservative or surgical treatment were assessed.The study includes 50 male (73.5%) and 18 female (26.5%) patients with a mean age of 9.1 years. The most common locations were the proximal humerus (69.2%, n = 47) and femur (16.2%, n = 11). In 43 cases (63.2%; upper limb n = 40, lower limb n = 3) a pathological fracture occurred. Fifty patients (73.5%; upper limb n = 40, lower limb n = 10) underwent a conservative treatment. In 11 cases (16.2.1%; upper limb n = 4, lower limb n = 7) an intralesional curettage and defect reconstruction with bone substitute without stabilization were performed. Five patients (7.3%; upper limb n = 4, lower limb n = 1) received an osteosynthesis, in two cases (2.9%; upper limb 1; lower limb 1) combined with an intralesional curettage and defect reconstruction with bone substitute. All 32 pathological fractures treated conservatively (upper limb n = 31, lower limb n = 1) healed within 6 weeks; 17/43 patients (39.5%) suffered at least one second fracture. After intralesional curettage and defect reconstruction with bone substitute local recurrence was observed in 5/13 cases (38.5%). Spontaneous consolidation, at least partially, was observed in three cases (4.4%) following conservative treatment after fracture. No relevant secondary angular or torsional deformity was observed after treatment.The majority of SBCs can be treated conservatively, especially in the upper extremity. However, if a fracture is completely dislocated, joint affecting, unstable or open, surgical treatment is necessary. Load-dependent pain or the inability to mobilize timely after fracture can necessitate surgical treatment in SBCs affecting the lower extremity. Spontaneous resolution, especially after fracture, can be seen in rare cases.

Retro-Odontoid and Retro-C2 Body Pseudotumor, Pannus, and/or Cyst. A Study Based on Analysis of 63 Cases.

OBJECTIVE: The potential significance of relationship of atlantoaxial instability with retro-odontoid pseudotumor, pannus, and/or cyst (RPC) is analyzed. METHODS: We searched the database of patients with craniovertebral junction-related instability treated by atlantoaxial fixation from January 2000 to March 2020. We identified 63 patients in whom there was an RPC in the region posterior to the odontoid process or posterior to the posterior aspect of the C2 body. RESULTS: The RPC was solid in 10 patients, predominantly cystic in 39 patients, and had both solid and cystic components in 14 patients. The vertical dimension of the RPC varied from 4.5 to 10.5 mm (average, 7.9 mm) and the transverse dimension ranged from 2 to 5.2 mm (average, 3.4 mm). In 51 patients, the RPC was in the midline and in 9 patients, it was eccentric in location. In 38 patients, there was erosion of the C2 body adjoining the RPC. Analysis of investigations showed that in 100% of patients, the dome of the RPC was in line with the most susceptible point of potential bone compression of neural structures. The RPC was eccentric in location in 9 patients presenting with torticollis. RPC indicated the presence of atlantoaxial instability even when there were no other positive and validated radiologic indicators. After atlantoaxial stabilization, the RPC spontaneously regressed or disappeared. Direct resection of the RPC was neither performed nor was necessary in any case. CONCLUSIONS: RPCs are secondary consequences of atlantoaxial instability and need not be primarily addressed by surgical resection. Their location suggests that they might have a neural protective function.

Synthetic Bone Graft Substitute for Treatment of Unicameral Bone Cysts.

BACKGROUND: Treatments for unicameral bone cysts (UBCs) have high documented failure rates (27% to 63%) because of recurrence or persistence of the cyst, similar to nonoperative management. Recent evidence suggests that filling of the defect with a synthetic bone graft substitute (SBGS) supports the weakened cortex and promotes new bone growth. A calcium sulfate, brushite, calcium phosphate, composite graft material (PRODENSE, Wright Medical, Memphis, TN) has been evaluated as a substitute for autogenous or allogenous graft in animal and human studies. The purpose of this study was to compare the rates of revision surgery in patients treated for UBCs with an SBGS compared with historical treatments with allograft or autologous bone marrow aspirate. METHODS: The authors reviewed 27 of 33 patients (age, 6 months to 21 years) an average of 121 months (range, 32 to 228) after filling of a UBC with an injection of SBGS (n=18) versus allograft or autologous bone marrow aspirate (n=9) between June 2008 and December 2017. Six patients with no follow-up were excluded. Groups did not differ in age at surgery, sex (19/27 male), history of pathologic fracture (22/27), or previous treatments (11/27). The primary outcome was the rate of revision surgery. Secondary outcomes included revision surgery-free survival as evaluated by the log-rank test, rate of postoperative fracture, persistent cysts, continued pain, and/or growth disturbance at the final follow-up. RESULTS: Seven of 9 patients treated with allograft or autograft underwent revision surgery for postoperative pathologic fracture (n=2) or resorption of the graft (n=5) compared with 2 of 18 patients injected with the SBGS, both treated for graft resorption. The use of SBGS was associated with a decreased need for revision surgery over all time periods (hazard ratio, 0.14; 95% confidence interval, 0.03-0.05). There was no significant difference between postoperative fracture (2/18 vs. 2/9), persistent cyst (7/18 vs. 5/9), pain (0/18 vs. 2/9), or growth disturbance (1/18 vs. 3/9). CONCLUSIONS: Treatment of UBCs with SBGS may decrease reoperation rates. Initial radiographic appearance after SBGS treatment shows solid structural support, followed by new bone formation. This appearance may lead to a less aggressive approach in considering revision surgery. LEVEL OF EVIDENCE: Level III-retrospective comparative study investigating the results of treatment.

Subchondral bone cysts regress after correction of malalignment in knee osteoarthritis: comply with Wolff's law.

PURPOSE: The purpose of this study is to discuss the mechanical function of subchondral bone cysts and its relationship with Wolff's law. METHODS: One hundred forty symptomatic knees (120 patients) with osteoarthritis were subjected to MRI before high tibial osteotomy (HTO). Subchondral bone cysts (SBCs) were detected on 72 knees of these 140 knees. SBCs, bone marrow lesion (BML), and hip-knee-ankle (HKA) axis were measured by using validated methods. After HTO, the evolution of cysts was evaluated on MRI performed with a five year follow-up on the 72 knees with pre-operative cysts. RESULTS: At baseline, 70 (97%) of these 72 knees had a BML surrounding the SBCs; the maximum cyst volume was 874 mm3 and the average cyst volume 9. 6 ± 4.1 mm3. In the subregions where cysts were present, adjacent cartilage was still present without full thickness defects. The mean pre-operative hip-knee-ankle angle was 7.3 ± 3 degrees (0° to 14°) of varus and differed significantly (p = 0.01) between the 68 knees without cysts (average 3 ± 2 degrees) and the 72 knees with cysts (average 9.2 ± 4 degrees). Five years after HTO, the number of cysts had decreased, the maximum cyst volume was 532 mm3, and the average cyst volume was 6.3 ± 2.8 mm3. CONCLUSION: Regression of subchondral bone cysts may be related to restoration of an appropriate load at the subchondral bone. With applying poroelasticity to bone mechaincs, this finding may suggest that SBCs and BMLs may be a physiological adaptation to mechanic overload. More basic research is needed to prove this matter.

Peroneal neuropathy caused by an extraneural ganglion cyst in the supracondylar area of the femur: A case report.

RATIONALE: Peroneal neuropathy is the most common type of peripheral neuropathy in the lower extremities. The peroneal nerve is usually compressed at the lateral aspect of the fibular head. Compression by ganglion cysts are one of the numerous underlying etiologies for peroneal nerve neuropathy and are most frequently located around the fibular neck and proximal tibiofibular joint. To the best of our knowledge, this is the first report of an extraneural ganglion cyst located at the level of the distal thigh that resulted in compressive peroneal neuropathy. PATIENT CONCERNS: We report a case of a 56-year-old man with sudden onset of left foot drop and gait disturbance caused by an extraneural ganglion cyst located in the popliteal fossa. DIAGNOSIS: Electrodiagnosis (EDX) suggested a peroneal nerve lesion. Subsequently, diagnostic ultrasonography (USG) revealed a cystic mass located within the left side of the supracondylar area of femur. Further magnetic resonance imaging confirmed that the mass was located at the proximal of popliteal fossa. INTERVENTIONS: Surgical excision was performed using a direct posterior approach. The cystic mass was compressing the common peroneal nerve, and was carefully and completely removed ensuring that all nerve branches were protected. OUTCOMES: A histopathologic evaluation confirmed the diagnosis of a ganglion cyst. There were no postoperative complications. Two months after the surgery, follow-up USG revealed no evidence of cyst recurrence or residual lesions. Six months after the surgery, the ankle dorsiflexor motor power improved and he experienced less pain and hypoesthesia. LESSONS: Physicians should bear in mind that the peroneal neuropathy can occur because of the ganglion cyst in the distal thigh. The thorough evaluation of EDX and USG is crucial for the early diagnosis and surgical intervention, although there is no abnormal finding around the fibular neck.

Is elastic stable intramedullary nail a good choice for pathological fractures of the proximal femur due to simple bone cyst in pediatric population?

Pathological fracture of the proximal femur represents a challenging situation for orthopedic surgeons because of the high risk of non-union, varus union, and avascular necrosis (AVN) of the femoral head. This study aims to investigate the efficacy of ESINs for the treatment of proximal femoral fractures caused by simple bone cysts (SBCs).All the patients with a diagnosis of proximal femoral fracture secondary to SBC treated with ESINs combined with bone grafting between January 2008 and January 2018, were analyzed retrospectively.In all, 11 patients were included in the Double ESINs group (5.1 ±â€Š0.8 years, 5 male, 6 female) and 27 patients were included in the Triple ESINs group (9.1 ±â€Š2.1 years, 11 male, 16 female). There was no significant difference between the 2 groups concerning the patients demographic parameters, including sex and affected side. However, the age in the Double group was significantly younger than those in the Triple group (P < .001). All patients in both groups displayed excellent outcomes according to the Musculoskeletal Tumor Society Score (MSTS), and there was no significant difference between the 2 groups at a 12-month follow-up evaluation (P = .10). As for the Capanna classification (1 + 2), there was no significant difference between these 2 groups (P = .24). In the Triple ESINs group, 24 (88.9%) patients were categorized in Capanna 1 and 2, whereas all patients in Double ESINs were Capanna 1 and 2. Overall, the success rate was 92%.ESINs combined with bone grafting is a successful strategy for proximal femoral fractures caused by SBCs in the pediatric population.

Injectable calcium sulfate vs mixed bone graft of autologous iliac bone and allogeneic bone: Which is the better bone graft material for unicameral bone cyst in humerus?

Unicameral bone cyst (UBC) is a benign fluid-filled lesion, mainly located in the metaphyses of long bones in children and adolescents. Elastic stable intramedullary nail (ESIN) is adopted in our institute for UBCs since 2010, and bone grafting was performed simultaneously. This study aims to evaluate the efficacy of ESIN decompression combined with different bone graft materials.All patients with the diagnoses of UBCs of the humerus, treated with ESINs and bone grafting between January 2010 and June 2018, were analyzed retrospectively. The bone grafting included injectable calcium sulfate, a mixture of the autologous iliac bone and allogeneic bone. All patients were categorized into 2 groups: ICS (injectable calcium sulfate) group and MIX (a mixture of the autologous iliac bone and allogeneic bone, ratio: 1:3) group. All the information was collected from the Hospital Database.In all, 17 patients (8.8 ±â€Š2.3-year-old, male 8, female 9) in the ICS group and 19 patients (8.9 ±â€Š1.9-year-old, male 10, female 9) in the MIX group were included in this study. Patients in both groups were followed up for more than 2 years (average, 3.4 ±â€Š1.3 years). No recurrence was observed in either group. There was no significant difference between the two groups concerning the patient's demographic parameters, including sex, age, and affected side. All patients in both groups displayed excellent and good shoulder function, and there was no significant difference between the 2 groups (P = .29). As for the Capanna classification, there was no significant difference between these 2 groups (P = .78).Intramedullary nailing has the advantage of a minimally invasive procedure, immediate stability, and continuous decompression. ICS showed similar results as a mixture of the autologous iliac bone and allogeneic bone.

Unusual osteolitic intraosseous ganglion cyst of the medial tibial condyle in a patient affected by mild osteoarthritis of the knee.

Bone lesion of the proximal tibia are common findings; depending on the site, age of the patient and symptoms a carefull differential diagnosis must be carried out. We present the case of  a 60 years old active patient presenting at our clinic with atraumatic  knee pain. X-Rays performed revealed an osteolitic lesion of the medial tibial condyle; MRI  highlighted a lobulated cystic lesion of the medial tibial condyle without evidence of interruption of the suchondral bone. The cavity appeared with low signal intensity on T1 weighted images and with a high signal intensity on T2 images  The tissue obtained from the incisional biopsy macroscopically revealed a clear, yellowish gelatinous and mucinous material; the microscopical hystological exam confirmed a cystic area of the lesion; the lumen contained some dense, fibrous matherial with focal mucoid degeneration, while the wall  was composed of a fibrous tissue with rare ossification and calcification.  Clinical history, imaging and histhological findings lead to a certain diagnosis of an intraosseous ganglion cyst. We decided to surgically treat the lesion with courettage and bone grafting with allograft;the anterior part of the deep medial collateral ligament was used to avoid the leakage of the transplanted bone. With limitations concerning the short follow up, we obtained an optimal result in terms of patients satisfaction; this result is mainly related to the relief of the pain and the possibility for the patient to return to his activities. An accurate follow up must be carried out to verify the integration of the allograft.