Treatment outcomes of the simple bone cyst: A comparative study of 2 surgical techniques using artificial bone substitutes

Surgical Treatment of Proximal Humerus Unicameral Bone Cyst: A Case Report

Unicameral bone cysts (UBCs) are noncancerous, fluid-containing sacs commonly seen in the metaphysis of long bones among young individuals, mainly affecting the proximal humerus and femur. Since they are painless, 80% of patients do not experience any symptoms from UBCs unless it is complicated by a pathological or stress fracture. These patients usually present with no history of trauma, with mild pain, local tenderness, and occasionally swelling. The diagnosis of UBCS can either be an incidental finding or can be made with the help of clinical features, radiographs, and differential diagnoses of UBCs like aneurysmal bone cyst, fibrous dysplasia, enchondroma, eosinophilic granuloma, and intraosseous ganglia can be ruled out. While identifying these cysts is often straightforward, there is ongoing debate regarding the optimal management approach. We report a case of a 16-year-old female with proximal humerus UBC who presented with a pathological fracture of the right proximal humerus. The patient was initially managed conservatively. However, she sustained a refracture at the same site twice over four years. Due to fracture recurrence and residual deformity, it was treated surgically with curettage, bone grafting, and internal fixation. The normal alignment and function of the right upper limb were restored postoperatively.

Treatment and Outcomes of 4,973 Unicameral Bone Cysts: A Systematic Review and Meta-Analysis

» Unicameral bone cysts (UBCs) can increase the risk of pathologic fractures of both long and short bones. Although multiple treatments exist, data are conflicting regarding optimal management.

» We sought to analyze treatment strategies for UBCs and their rates of successful treatment.

» Success rates were analyzed according to treatment modality, with emphasis on filling techniques and/or decompression associated with curettage, and injection compounds.

» Curettage with bone substitute and cyst decompression was identified as a highly successful technique for UBC treatment.

» Decompressing the cyst wall after injection, regardless of the specific compound used, had a greater potential to enhance healing rates.

» The management decision should be individually guided within the patient's context.

High tartrate-resistant acid phosphatase (TRACP 5b) level in cystic fluid is a significant prognostic marker for postoperative recurrence in solitary bone cysts

PURPOSE

The pathogenesis of cystic fluid storage in solitary bone cysts remains unclear. We aimed to compare the results of the biochemical analysis of cystic fluid with clinical findings. We identified a significant marker of postoperative recurrence.

METHODS

Twenty-seven male and eight female patients were studied; the median age at diagnosis was 11 (5-23) years. The mean follow-up period was 60 months (range: 14-146 months). Clinical information including sex, age, affected site, radiological findings of phase (active or latent), surgical procedure, outcome, and biochemical analysis of serum and cystic fluid was obtained.

RESULTS

The 5-year healing rate was 64.0%. Biochemical analysis revealed that total protein and albumin values in the cystic fluid were significantly lower, compared to those in the serum. Levels of bone turnover markers, such as alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b were remarkably elevated in the cystic fluid than in the serum. R values were 0.127, 0.076, and 0.095 for alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b, respectively. Areas under the receiver operating characteristic curves, calculated to assess the association of alkaline phosphatase, bone-specific alkaline phosphatase, and tartrate-resistant acid phosphatase 5b levels in the cystic fluid with postoperative recurrence, were 0.57, 0.51, and 0.70, respectively.

CONCLUSIONS

No clear correlation of bone turnover marker levels between the serum and cystic fluid was observed. The high tartrate-resistant acid phosphatase 5b level in the cystic fluid was associated with postoperative recurrence. The bone resorption caused by osteoclasts is considered to affect postoperative recurrence.

LEVEL OF EVIDENCE

Level IV.

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 ± 0.8 years, 5 male, 6 female) and 27 patients were included in the Triple ESINs group (9.1 ± 2.1 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.

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.

Treatment of simple bone cysts of the humerus by intramedullary nailing and steroid injection

Background

Simple bone cysts (SBCs) are common benign lytic bone lesions in children. This study focused on exploring a clinical treatment method, minimally invasive intramedullary decompression and drainage with elastic stable intramedullary nailing (ESIN) combined with intralesional injections of steroids, and evaluated its effectiveness, complications and morbidity through functional and radiographic outcomes.

Methods

The postoperative recovery of 18 children who suffered from SBCs of humerus was evaluated (mean follow-up, 40 months) from January 2009 to December 2016. These patients (11 males, 7 females; 8 in the left, 10 in the right; mean age, 10.9 years old) were treated with minimally invasive intramedullary decompression and drainage with ESIN combined with intralesional injections of steroids. The diagnosis was based on not only pre-operative typical medical images (X-rays/CT/MRI) but also surgical findings and pathological diagnosis. Radiological and functional outcomes were evaluated according to Capanna and Musculoskeletal Tumor Society (MSTS) score. The interclass differences were analyzed by t-test.

Results

According to Capanna and MSTS criteria, after treatment, 14 patients made full recoveries which was presented by all the cysts filled with bone tissue, and 4 patients made partially recoveries, which were presented by cystic spaces partially filled with low density bone. All the cysts responded to treatment method, and there was no cyst recurrence. All except 2 patients had good functional results. One of the two patients had irritation of the end of the nail and one patient had a valgus deformity.

Conclusions

Treatment for SBCs of humerus by minimally invasive intramedullary decompression and drainage with ESIN combined with intralesional injections of steroids is safe, effective and convenient. The clinical effect is satisfactory and worth popularizing.

Current Trends and Variations in the Treatment of Unicameral Bone Cysts of the Humerus: A Survey of EPOS and POSNA Members

BACKGROUND

A variety of treatment methods have so far been described for unicameral bone cysts (UBC). However, to the best of our knowledge, no particular consensus has yet been reached on when to operatively treat a patient with a humeral UBC. Therefore, members of the European Pediatric Orthopedic Society (EPOS) and Pediatric Orthopedic Society of North America (POSNA) were surveyed to characterize current treatment preferences.

METHODS

An online electronic questionnaire was sent out to all registered EPOS and POSNA members. The survey comprised 45 questions related to the diagnosis, treatment, and follow-up characteristics of patients with UBCs of the humerus. Particular questions related to the nonoperative or surgical treatment of pathologic proximal humerus and humeral shaft fractures were also included.

RESULTS

In total, 444 participants (132 EPOS and 292 POSNA members) responded, of whom 400 were actively involved in UBC treatment. The preferred diagnostic modalities to confirm the diagnosis of a UBC in the humerus were radiographs (88%), MRI in cases of questionable diagnosis (58%) or CT scan (8%). For painless UBCs 67% prefer no treatment at all except when the fracture risk is deemed high (then 53% recommend surgery); 71% of respondents would treat painful UBCs with surgery. Most common surgical techniques comprise curettage (45%), artificial bone substitutes (37%), corticosteroid injection (29%), or intramedullary stabilization (eg, rodding; 24%).Fractured, nondisplaced and mildly displaced proximal humerus UBCs and mildly displaced pathologic humerus shaft fractures are all preferably treated nonoperatively (94%, 91%, 83%, respectively). Severely displaced pathologic proximal humerus fractures are treated less often conservatively (36%) than surgically (40%), and severely displaced humerus shaft fractures are preferably treated surgically (63%) by intramedullary stabilization (60%).

CONCLUSIONS

There is great variation among EPOS and POSNA members with regards to the diagnosis and treatment of UBCs in the humerus. Although some consensus on general treatment principles is seen, specific surgical treatment indications vary.Prospective randomized-controlled studies are needed to evaluate the outcomes of the different surgical approaches compared with nonoperative strategies.

LEVEL OF EVIDENCE

Level V-expert opinion.

Comparison of curettage and bone grafting combined with elastic intramedullary nailing vs curettage and bone grafting in the treatment of long bone cysts in children

To compare the efficacy of curettage and bone grafting combined with elastic intramedullary nailing (EIN) vs curettage and bone grafting in the treatment of long bone cysts in children and to clarify the necessity of using EIN in the treatment of bone cysts.Sixty-two patients were involved in this study from Jan. 2009 to Sept. 2017 (43 males, 19 females; 27 humeri, 35 femurs); the patients were assigned to an EIN group, comprising 30 patients who underwent curettage and bone grafting combined with EIN, or to a non-elastic intramedullary nailing (NEIN) group, comprising 32 patients who underwent curettage and bone grafting alone. The prognosis of the 2 groups was assessed with reference to the standard of Capanna.No statistically significant differences in sex, age, location, activity, pathological fracture, cyst volume, operative time and intraoperative blood loss were found between the 2 groups (P > .05). The effective rate was 90.0% in the EIN group and 68.8% in the NEIN group, and the difference was statistically significant (P < .05).Compared to simple curettage and bone grafting, curettage and bone grafting combined with EIN treatment can significantly improve the prognosis of children with bone cysts. It is recommended that EIN be added to bone cyst curettage and bone grafting.