Unicameral (Simple) Bone Cysts

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.

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.

Advanced Unilateral Fibrous Dysplasia of the Scapula: A Rare Clinical Entity and Surgical Challenge

Introduction:

Fibrous dysplasia (FD) is an uncommon benign tumor of bone. Although FD can affect flat bones, it is rare for the scapula to be involved. In addition, little is known about the management of FD when it involves the scapula. We present possibly the first comprehensive case report of the management of advanced unilateral FD of the scapular region.

Case Report:

A 47-year-old male presented to us with pain and swelling over the left shoulder. The swelling was 11 cm × 15 cm × 8 cm and was hard and tender with rough texture. Radiograph showed large homogenous lesion with irregular but well-defined margins and a ground glass appearance. Magnetic resonance imaging scans showed well-defined borders with the expansion of the bone, with intact overlying cortices and endosteal scalloping. Biopsy confirmed the lesion to be FD. An innovative application of an existing surgical technique to minimize the impact of the residual deformity and dead space left after curettage of the scapula was done. The patient had good clinical and functional outcome at 6-month follow-up.

Conclusion:

Surgical exercise in FD is purely on symptomatic basis. In our case, the swelling was causing most discomfort, and we curettaged and compressed the bony swelling which resulted in excellent outcome in this patient.

[Bone cysts-differential diagnosis and therapeutic approach]

The differential diagnosis of cystic lesions of the skeleton is multifarious. Besides patient age, the localization and radiologic morphology provide important information for a closer differentiation. Juvenile and aneurysmal bone cysts represent two frequent entities in growing patients. The fluid content of the cysts helps in distinguishing between juvenile and aneurysmal bone cysts. Whereas juvenile bone cysts contain clear fluid, the content of aneurysmal bone cysts consists of blood combined with solid tissue. With respect to progression, aneurysmal bone cysts show a higher activity than solitary bone cysts. The treatment of juvenile bone cysts usually consists of curettage including filling with bone replacement material. For aneurysmal bone cysts the additional use of adjuvants is recommended. Bone cement is preferably used for filling. It shows favorable properties for prophylaxis of recurrence and facilitates the recognition of relapses. Both juvenile and aneurysmal bone cysts often show recurrences.

Multiloculated solitary (unicameral) bone cyst in a young dog

A 20-month-old female spayed Staffordshire Terrier (22.3 kg) presented to the Orthopedic Surgery Service at North Carolina State University Veterinary Teaching Hospital for evaluation of a 6-week history of toe-touching to nonweight-bearing lameness in the right hind limb. Radiographs of the right stifle revealed a multiloculated lytic lesion of the distal femur, with a large open lytic zone centrally, numerous osseous septations peripherally, and focal areas of cortical thinning and loss. An aspirate of the right distal femoral lesion yielded mildly cloudy serosanguineous fluid. Cytologic examination of the fluid revealed a pleomorphic population of discrete cells that exhibited marked anisocytosis and anisokaryosis and a variable nuclear-to-cytoplasmic (N:C) ratio, which were interpreted as probable neoplastic cells, with few macrophages, and evidence of hemorrhage. Given the clinical signs of pain, lesion size, and concern for malignant neoplasia, amputation of the right hind limb was performed. Histologically, the lesion had undulating walls 1-3 mm thick with a continuous outer layer of dense fibrous tissue and an inner layer composed of reactive cancellous bone with no cortical compacta remaining. Remnants of thin fibrous or fibro-osseous septa projected from the bony wall into the cyst lumen. The final histologic diagnosis was a benign multiloculated solitary (unicameral) bone cyst of the distal right femur. Based on the histopathologic findings, it was speculated that the cells identified on cytology were a mixture of developing osteoclasts, osteoblasts, endothelial, and stromal cells. This is the first report describing the cytologic examination of a solitary bone cyst in veterinary medicine.

Treatment of a Simple Bone Cyst Using a Cannulated Hydroxyapatite Pin

Simple bone cysts (SBCs) are benign bone tumors. However, the treatment of SBCs remains controversial because of their healing rate and the invasiveness of surgery. The purpose of the present study was to evaluate the treatment of SBCs using a cannulated hydroxyapatite (HA) pin.A total of 43 patients (35 males, 8 females; mean age 12.1 years; age range, 5-22 years) with SBCs were treated with continuous decompression by inserting ceramic HA pins between 1989 and 2014. The SBCs were located in the calcaneus in 23, the humerus in 15, the femur in 3, and the pelvis in 2 cases. In all patients, minimal fenestration of the cyst wall and curettage and multiple drilling in the cyst wall were performed, followed by insertion of the HA pin. The mean follow-up period was 26.6 months. Operating time, healing period, risk factors for recurrence, and the cure rate were evaluated.Healing was achieved without intervention in 38 patients after a mean of 6.4 months. Two patients had persistent small residual cysts, which had no changes after 1 year at the latest follow-up. There were 5 patients with recurrences (humerus 4, femur 1), who were cured by curettage and artificial bone grafting. The final healing rate by cannulation only using an HA pin was 88.2%. On Fisher exact test, age, site of SBCs, and distance from the physis were found to be significantly associated with SBC recurrence (P < 0.05).In the present study, cannulation using an HA pin for SBCs was found to be a useful technique, particularly for calcaneal cysts, because it is a minimally invasive procedure with a high cure rate. In patients <10 years, involvement of the humerus and contact with the growth plate were significant risk factors for SBC recurrence.

Treatment of unicameral bone cyst: systematic review and meta analysis

PURPOSE

Different treatment modalities have been utilized to treat unicameral bone cyst (UBC), but evidence has not been fully described to support one treatment over another and the optimal treatment is controversial. The aim of this quantitative systematic review was to assess the effectiveness of different UBC treatment modalities.

METHODS

We utilized Pubmed to isolate retrospective studies on patients with UBC who received any kind of treatment. The included studies needed to have a minimum sample size of 15 patients, and have provided data on radiographic healing outcome.

RESULTS

Sixty-two articles were selected for the meta-analysis from a total of 463 articles. The cumulative sample size was 3,211 patients with 3,217 UBC, and male to female ratio was 2.2:1. The summary or pool estimate of methylprednisolone acetate (MPA) injection resulted in a healing rate of (77.4 %) that was comparable to bone marrow injection (77.9 %). A higher healing rate was observed with MPA injection when inner wall disruption was performed. The pool estimate of bone marrow with demineralized bone matrix injection was high (98.7 %). UBC healing rate after surgical curettage was comparable whether autograft or allograft was utilized (90 %). UBC treatment with flexible intramedullary nails without curettage provided almost 100% healing rate, while continuous decompression with cannulated screws provided 89 % healing rate. Conservative treatment indicated a healing rate of 64.2, 95 % CI (26.7-101.8).

CONCLUSIONS

Active treatment for UBC provided variable healing rates and the outcomes were favorable relative to conservative treatment. Due to the heterogeneity of the studies and reporting bias, the interpretation of these findings should be handled with caution.

Application of distraction osteogenesis in managing bone cysts

BACKGROUND

Despite the great amount of research concerning bone cysts, there is still no commonly accepted method of treatment. The aim of this study was to evaluate the effectiveness managing bone cyst with hybrid external fixator by distraction osteogenesis.

MATERIALS AND METHODS

Between 1982 and 2009, 25 patients with unicameral (20 patients) and aneurismal (five patients) bone cysts were treated using this method. Eighteen patients had a history of pathological fracture at the same location. Cysts were located in the humerus, femur, tibia, and radius. Median follow-up was 48 (range 31-91) months. Results were evaluated on plain radiographs according to the classification system of Capanna et al. Functional assessment was done using the modified system recommended by Enneking et al.

RESULTS

In our study group of 25 bone cysts, 15 were classified as completely healed and nine as healed with residual radiolucency. Recurrence was observed in one patient. Absence of response to treatment was not observed. All patients had excellent functional outcomes, except one with recurrence who was rated poor.

CONCLUSIONS

As bone cysts are found in long bones in 90-95 % of patients, and taking into account our achieved positive results in almost all patients, we recommend this method of distraction osteogenesis as a treatment option. It is an effective, economical method of treatment, which eliminates deformity and restores bone length, especially in patients with pathologic fractures.

An abnormal bone lesion of the scapula in a collegiate basketball player: a case report

OBJECTIVE

To present the case of a bone lesion of the scapula in a collegiate basketball player.

BACKGROUND

A 19-year-old National Collegiate Athletic Association Division I male basketball player presented with pain in the posterior region of the right shoulder. During practice, he was performing a layup when his arm was forced into hyperflexion by a defender. Evaluation revealed a bone lesion involving the scapular spine and base of the acromion.

DIFFERENTIAL DIAGNOSIS

Acromioclavicular joint sprain, subacromial bursitis, subscapular bursitis, humeral head contusion, acromial fracture.

TREATMENT

The patient was treated for 2 months with therapeutic modalities and rehabilitation exercises. Because of persistent pain and the risk of a pathologic fracture, open surgical biopsy and bone grafting were then undertaken.

UNIQUENESS

Most simple bone cysts affect the proximal humerus and femur, whereas our patient's lesion was in the acromial complex.

CONCLUSIONS

Athletic trainers should be alert to the unusual possibility of bone cysts, which are usually identified incidentally when radiographs are obtained for other reasons. Most simple bone cysts are asymptomatic, but a pathologic fracture can occur with trauma.

Three-part head-splitting proximal humerus fracture through a unicameral bone cyst

Unicameral bone cysts are rare in adults and are most often found incidentally on radiographs. However, they can persist from the adolescent period and may be present in locations that predispose to or exacerbate fractures.This article describes a case of a healthy 40-year-old woman who sustained a proximal humerus trauma that involved a large unicameral bone cyst, resulting in a 3-part head-splitting fracture. The epiphyseal location of the cyst contributed to the severity and extent of the fracture that resulted from a simple fall. Given the age of the patient, open reduction and internal fixation with a locking plate and lag screws was performed. The patient chose open reduction and internal fixation to preserve a hemiarthroplasty procedure in case of future revision. Successful humeral head reconstruction was achieved, and the patient fully recovered. One year postoperatively, the patient underwent arthroscopic debridement to alleviate subjective stiffness and decreased range of motion.Multipart head-splitting fractures require complex repair strategies. The gold standard for the treatment of these injuries is hemiarthroplasty. However, the decision process is difficult in a young patient given the average survival of autoplastic prostheses and the added difficulty of later revision. The current case demonstrates the complexity of decision making resulting from a rare injury in a young, healthy patient and shows that open reduction and internal fixation can provide acceptable reconstruction in such situations.

Mid- and long-term clinical results of surgical therapy in unicameral bone cysts

Background

Unicameral (or simple) bone cysts (UBC) are benign tumours most often located in long bones of children and adolescents. Pathological fractures are common, and due to high recurrence rates, these lesions remain a challenge to treat. Numerous surgical procedures have been proposed, but there is no general consensus of the ideal treatment. The aim of this investigation therefore was to study the long-term outcome after surgical treatment in UBC.

Methods

A retrospective analysis of 46 patients surgically treated for UBC was performed for short and mid-term outcome. Clinical and radiological outcome parameters were studied according to a modified Neer classification system. Long-term clinical information was retrieved via a questionnaire at a minimum follow-up of 10 years after surgery.

Results

Forty-six patients (17 female, 29 male) with a mean age of 10.0 ± 4.8 years and with histopathologically confirmed diagnosis of UBC were included. Pathological fractures were observed in 21 cases (46%). All patients underwent surgery for UBC (35 patients underwent curettage and bone grafting as a primary therapy, 4 curettage alone, 3 received corticoid instillation and 4 decompression by cannulated screws). Overall recurrence rate after the first surgical treatment was 39% (18/46), second (17.4% of all patients) and third recurrence (4.3%) were frequently observed and were addressed by revision surgery. Recurrence was significantly higher in young and in male patients as well as in active cysts. After a mean of 52 months, 40 out of 46 cysts were considered healed. Prognosis was significantly better when recurrence was observed later than 30 months after therapy. After a mean follow-up of 15.5 ± 6.2 years, 40 patients acknowledged clinically excellent results, while five reported mild and casual pain. Only one patient reported a mild limitation of range of motion.

Conclusions

Our results suggest satisfactory overall long-term outcome for the surgical treatment of UBC, although short-and mid-term observation show a considerable rate of recurrence independent of the surgical technique.

Distance from the growth plate and Its relation to the outcome of unicameral bone cyst treatment

BACKGROUND

Interventions to treat unicameral bone cysts vary. Nonetheless, regardless of the intervention modality, the outcome is not certain. The purpose of this study was to determine if the distance between the growth plate and the cyst can be used to predict the outcome of the treatment.

METHODS AND MATERIALS

Retrospectively, we assessed the outcome of 39 interventions in nineteen children that were performed between 1994 and 2003. Seventeen different modalities of treatment were employed. There were three female and sixteen male patients. The average age was 8 years. Nine cysts were in the greater trochanter area, three were in the femoral capital area and seven were in the proximal humerus. According to the cyst's distance from the growth plate, at the intervention time, there were 18 cases within less than 2 cm and 21 cases of more than 2 cm.

RESULTS

Complete healing was achieved in 10 children (employing seven different modalities). In nine of them, the cysts were more than 2 cm away from the growth plate. In one child, the cyst was within less than 2 cm of the growth plate, however, treatment here involved epiphyseodesis.

DISCUSSION

This study confirmed that, regardless of intervention modality, complete healing was not achievable in those cysts that are within less than 2 cm of an active growth plate. Complete healing was possible in those cysts that are more than 2 cm away from the growth plate.

CONCLUSION

The 2-cm distance from the growth plate could be used as a predictor of treatment outcome of unicameral bone cysts.

Case report: unicameral bone cysts in a young patient with acquired generalized lipodystrophy

We report the case of a 13-year-old boy with bilateral distal femoral unicameral bone cysts (UBCs) associated with acquired generalized lipodystrophy. As opposed to congenital generalized lipodystrophy, cystic bone lesions in acquired generalized lipodystrophy are rare. After radiographic and histologic confirmation of the UBCs, we performed percutaneous intramedullary decompression, curettage, and grafting. UBCs can be an important manifestation of acquired generalized lipodystrophy. Cystic bone lesions appear to be less common in acquired generalized lipodystrophy than in congenital generalized lipodystrophy, and intramedullary adipose tissue loss may be a predisposing factor for the development of bone lesions in patients with acquired generalized lipodystrophy. When evaluating a patient with lipodystrophy, doctors should recognize the clinical course may include the development of UBCs.

Unicameral bone cyst of the humeral head: arthroscopic curettage and bone grafting

Arthroscopic surgery has improved greatly over the past decade. Treatment of various juxta-articular disorders around the shoulder have benefited from endoscopic approaches. Cystic lesions of the shoulder on the scapular side have been treated in this way. This article describes a case of a 29-year-old patient with a unicameral bone cyst on the posterior aspect of the humeral head. Arthroscopic visualization using an accessory posteroinferior portal localized the cyst through the bare area of the humeral head. A cannulated burr was used to create an opening through the cortical wall between the cyst and the joint, and a careful curettage was performed. The cavity was filled with a demineralized bone matrix enriched with autologous blood packed into an arthroscopic cannula and delivered through the accessory portal. The patient reported pain relief immediately postoperatively and at follow-up. This case demonstrates the feasibility of arthroscopic treatment of a simple bone cyst of the humeral head. We believe that the knowledge of the juxta-articular anatomy allows the applications of scope-assisted procedures to be expanded, maximizing the results of a technique that allows a shorter recovery and less painful rehabilitation.