Endoscopic Versus Open Surgery for Calcaneal Bone Cysts: A Preliminary Report

Allogenic Cancellous Bone versus Injectable Bone Substitute for Endoscopic Treatment of Simple Bone Cyst and Intraosseous Lipoma of the Calcaneus and Is Intraosseous Lipoma a Developmental Stage of a Simple Bone Cyst?

Simple bone cysts (SBCs) and intraosseous lipoma (IOL) of the calcaneus are rare tumor entities that are primarily diagnosed due to unspecific heel pain, incidental findings, or rarely due to pathological fractures. Compared to traditional open tumor resections, endoscopic resection of these benign tumors aims to minimize surgical morbidity and maximize surgical efficiency without compromising safety. Grafting is regularly performed to reduce the risk of recurrence and stimulate osseous consolidation of the lytic lesion. As the incidence is low and treatment strategies are heterogeneous, there is no clear consensus for the treatment of simple cysts or intraosseous lipomas of the calcaneus. The objectives of this study are (a) to present medium to long-term results after endoscopic resection and grafting with allogenic cancellous bone or bioresorbable hydroxyapatite and calcium sulfate cement, and (b) to add further evidence to the discussion of whether calcaneal SBC and IOL are the same entity at different developmental stages. Between 2012 and 2019, a total of 25 benign bone tumors consisting of 17 SBCs and 8 IOLs were treated by A.T. with endoscopic resection and grafting, comprising the largest cohort to date. For grafting, 12 patients received allogenic cancellous bone (group A) and 13 patients received injectable bone substitute (group B). Pre- and postoperative imaging using plain X-rays and MRI was retrospectively analyzed with a mean follow-up time of 24.5 months to assess tumor size, osseous consolidation (modified Neer classification), and tumor recurrence. A retrospective chart analysis focusing on adverse intra- and perioperative events and other complications associated with the surgical procedure was performed using the modified Clavien-Dindo classification (CD1-3). A total of 12/13 cases with allogenic bone grafting showed a Neer Type 1 osseous healing of the tumorous lesion after endoscopic resection, whereas only 5/11 cases with injectable bone substitute showed sufficient healing (types 1 and 2). There were three recurrent cysts (Neer 4) and two persistent cysts (Neer 3) after using injectable bone substitute. Two CD1 complications were observed in group A (prolonged wound drainage, sural neuritis) and eight complications were observed in group B (6× CD1, 2× CD3). At least two IOLs diagnosed preoperatively using MRI were ultimately identified as SBCs upon histopathologic examination. Allogenic cancellous bone grafting after endoscopic resection of calcaneal SBC or IOL showed a very low rate of complications and no tumor recurrence in our series. On the other hand, depending on the material used, injectable bone substitute showed a high rate of "white-out" (excessive drainage), resulting in multiple complications such as prolonged wound healing, insufficient permanent defect filling, recurrence, and revision surgery. Over time, calcaneal SBC may transform into IOL, exhibiting distinct features of both entities simultaneously during ossoscopy and histopathological analysis.

Pathological fracture of a solitary bone cyst in the calcaneus: a case series and literature review

INTRODUCTION

Solitary bone cysts in the calcaneus (calcaneal bone cysts) are often asymptomatic. Pathological fractures are rare, and few reports are available concerning its risk assessment. Therefore, the indication for operative interventions remains debatable, and further discussion on the treatment of symptomatic cysts and pathological fractures in calcaneal bone cysts is necessary.

MATERIALS AND METHODS

Clinical data of 21 patients with calcaneal bone cysts (16 men and five women) was retrospectively reviewed. The average age was 13.3 (range, 7-23) years. Clinical data, such as concerning symptoms, radiological findings, pathological findings and outcomes, were investigated, and the pathogenesis of symptomatic cysts was studied.

RESULTS

Thirteen cysts were symptomatic, and eight were incidentally discovered. Computed tomography revealed no fracture in 12 cases, microfracture in eight and complete fracture in one. The areas under the curves of the receiver operating characteristic curves calculated to establish an association between cyst size and symptoms and cyst size and pathological fractures (microfracture and complete fracture) were 0.78 and 0.71, respectively. Symptomatic cysts and pathological fractures were associated with the cyst ratio (cyst size/calcaneus ≥ 0.20). On magnetic resonance imaging (MRI), fluid levels were observed in 11 of 21 (52%) patients. At the time of surgery, blood from the haemorrhage was aspirated from 15 of 21 (71%) cysts.

CONCLUSIONS

Orthopaedic surgeons should be aware that the cyst ratio is associated with clinical symptoms and pathological fractures. MRI and gross findings revealed haemorrhage in the cystic fluid. In calcaneal bone cysts, repeated microfractures and spontaneous healing might occur.

Management of Calcaneal Cysts in the Pediatric Population: A Review

Cysts of the bone are a common pathology that, although benign, are frequently treated because of their tendency to compromise the integrity of affected bone. Two common entities are unicameral bone cysts and aneurysmal bone cysts. Although these are two distinct pathologies, they are treated similarly and thus will be discussed in tandem. The optimal treatment of calcaneal bone cysts in pediatric patients has long been debated among orthopaedic surgeons because of the relatively small number of cases and varied results within the literature. Currently, there are three lines of thought regarding treatment: observation, injection, and surgical intervention. When considering which course of treatment is best for an individual patient, the surgeon must consider the fracture risk without treatment, the risk of complications with treatment, and the recurrence rate with each treatment approach. There are limited data on pediatric calcaneal cysts specifically. Still, there are much data concerning simple bone cysts of long bones in the pediatric population and calcaneal cysts in the adult population. Because of the lack of literature on the subject, there is a need for a review of the available literature and a consensus on the approach to treating calcaneal cysts in the pediatric population.

Endoscopic curettage and allografting of simple bone cysts of the calcaneus in young soccer players: Report of three cases

Open curettage with bone graft has been the traditionally suggested surgical treatment for the symptomatic simple (or unicameral as they used to be called) calcaneal bone cyst. Less invasive endoscopically assisted treatment with curettage and bone grafting with allograft have recently provided less postoperative morbidity. The aim of the present study is to present our experience with this method in young soccer athletes. Between April 2014 and May 2016 three consecutive young soccer players with symptomatic calcaneal bone cysts underwent endoscopic curettage, and percutaneous injection of demineralized bone matrix allograft. The mean age was 17.3 (16, 17 and 19 years old), and the mean follow-up was 32.1 (range 24-47) months. Both radiographic and functional follow-up, using the AOFAS score, showed good to excellent results. All lesions were radiographically healed. Preoperative AOFAS score (max. 100 pts) was 78.6 ± 4.7, improving to 98.0 ± 4.1. The patients returned to their initial level of sports activities within 18.3 (range 17-19) weeks after surgery. Evidence suggests an earlier return to sports using bone substitutes. However, the present study showed that endoscopic curettage and percutaneous injection of bone allograft is also an excellent treatment option for young athletes with a symptomatic calcaneal bone cyst. LEVEL OF CLINICAL EVIDENCE: 4.

Endoscopic Curettage and Bone Grafting of Intraosseous Ganglion of the Second Metatarsal

Intraosseous ganglion is a benign cystic lesion located in the subchondral region and in the epiphyseal areas of long and short tubular bones. It occasionally extends to the metaphysis and diaphysis regions and rarely involves the metatarsal bone. In this report, a case of intraosseous ganglion of the second metatarsal extending from metaphysis to diaphysis was presented. This presented with dull aching pain of the forefoot dorsum, and the diagnosis was confirmed by magnetic resonance imaging. It was successfully treated by endoscopic curettage and bone grafting without the need of lengthy incision of open surgery. The patient remained asymptomatic and had no evidence of local recurrence 28 months after the surgery. This report demonstrated the feasibility of endoscopic surgery in treatment of extensive intraosseous benign lesion of the metatarsal bone.

Efficacy of Lesion Specific Portals in Endoscopic Treatment of Calcaneal Bone Cyst: A Case Report and Literature Review

Background: Calcaneal bone cysts rarely occur and most of them are known to be benign. Among them, simple bone cysts (SBCs) third most commonly occur in the calcaneus and of the many surgical treatment options, endoscopic curettage is recently gaining popularity among surgeons due to its advantages of minimal invasiveness and optimal visualization. As for portal placement for endoscopy, two lateral portals are considered a standard technique, but no rationale has been established for SBCs with abnormal geometry. This case report suggests an SBC with secondary aneurysmal change located outside the Ward’s triangle, as well as an appropriate endoscopic approach. Case Presentation: An 18-year-old male high school student presented with a main complaint of pain at the hind foot level for the past one year, without significant improvement from conservative treatment. An endoscopic curettage through the lesion specific two posterior portals and bone graft using allogeneic cancellous bone were performed. SBC with a secondary aneurysmal bone cyst was diagnosed on pathology. At a one-year follow-up, the patient was painless and had returned to his regular activities. Physical and radiographic examinations revealed that the lesion was completely healed without any evidence of recurrence. Conclusion: For calcaneal bone cysts located at the posterior aspect of the calcaneus, eccentrically medial and abnormally long anterior-posteriorly, we suggest an endoscopic procedure using lesion specific portals such as two posterior portals.

Multifunctional antibiotic- and zinc-containing mesoporous bioactive glass scaffolds to fight bone infection

Bone regeneration is a clinical challenge which requires multiple approaches. Sometimes, it also includes the development of osteogenic and antibacterial biomaterials to treat the emergence of possible infection processes arising from surgery. This study evaluates the antibacterial properties of gelatin-coated meso-macroporous scaffolds based on the bioactive glass 80%SiO₂-15%CaO-5%P₂O₅ (mol-%) before (BL-GE) and after being doped with 4% of ZnO (4ZN-GE) and loaded with both saturated and the minimal inhibitory concentrations of one of the antibiotics: levofloxacin (LEVO), vancomycin (VANCO), rifampicin (RIFAM) or gentamicin (GENTA). After physical-chemical characterization of materials, release studies of inorganic ions and antibiotics from the scaffolds were carried out. Moreover, molecular modelling allowed determining the electrostatic potential density maps and the hydrogen bonds of antibiotics and the glass matrix. Antibacterial in vitro studies (in planktonic, inhibition halos and biofilm destruction) with S. aureus and E. coli as bacteria models showed a synergistic effect of zinc ions and antibiotics. The effect was especially noticeable in planktonic cultures of S. aureus with 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and in E. coli cultures with LEVO or GENTA. Moreover, S. aureus biofilms were completely destroyed by 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and the E. coli biofilm total destruction was accomplished with 4ZN-GE scaffolds loaded with GENTA or LEVO. This approach could be an important step in the fight against microbial resistance and provide needed options for bone infection treatment. STATEMENT OF SIGNIFICANCE: Antibacterial capabilities of scaffolds based on mesoporous bioactive glasses before and after adding a 4% ZnO and loading with saturated and minimal inhibitory concentrations of levofloxacin, vancomycin, gentamicin or rifampicin were evaluated. Staphylococcus aureus and Escherichia coli were the infection model strains for the performed assays of inhibition zone, planktonic growth and biofilm. Good inhibition results and a synergistic effect of zinc ions released from scaffolds and antibiotics were observed. Thus, the amount of antibiotic required to inhibit the bacterial planktonic growth was substantially reduced with the ZnO inclusion in the scaffold. This study shows that the ZnO-MBG osteogenic scaffolds are multifunctional tools in bone tissue engineering because they are able to fight bacterial infections with lower antibiotic dosage.

Treatment of simple bone cysts using endoscopic curettage: a case series analysis

Background

Endoscopic curettage is considered applicable for the treatment of simple bone cysts with the expectation that it might be less invasive than open curettage. In this study, we investigated the efficacy of endoscopic curettage for the treatment of simple bone cysts. The goal was to investigate the incidence of cyst recurrence and bone healing after endoscopic curettage. Moreover, complications and functionality at the final follow-up were evaluated.

Methods

From 2003 to 2014, 37 patients with simple bone cysts underwent endoscopic curettage. Twenty-four were male and 13 were female, with a mean age of 14.7 years. Endoscopic curettage was performed with the support of an arthroscope via 7–8 mm holes penetrated by cannulated drills with a small incision. The cysts underwent curettage using angled curettes, rongeurs, and an electrical shaver until the normal bone was observed in the medullary cavity. To investigate the bone healing after endoscopic curettage, we evaluated the consolidation of the cyst at the final evaluation (Modified Neer Classification) and the time to solid union after operation, which was defined as the sufficient thickness of the cortical bone to prevent fracture and allow physical activities.

Results

Recurrence occurred in seven patients (18.9%). A log-rank analysis revealed that contact with the physis was associated with recurrence (p = 0.006). Among 31 patients (83.7%), the consolidation of cyst was considered healed at the final X-ray follow-up period, and in these patients, the mean time taken for solid union of cortical bone thinning was 4.0 months (standard deviation, 2.4). With regard to major complications of endoscopic curettage, a transient radial nerve palsy and two postoperative fractures occurred. The former problem was managed conservatively and the latter problems by transient internal fixation; these problems were managed without any further complications. All patients had a good postoperative function.

Conclusions

Endoscopic curettage might be a useful alternative as it is a minimally invasive procedure for the treatment of simple bone cysts. Considering the relatively smaller size of this study, further investigation should be necessary for deducing the reliable conclusion.