Vascular extravasation of injectable bioresorbable bone cement during aspiration and injection of calcaneal bone cyst

Abstract

A 27-year-old woman underwent aspiration and bioresorbable cement injection of a simple bone cyst. During injection, cement was seen on fluoroscopy extravasating into the posterior vein of the ankle. The procedure was immediately stopped, and the patient remained hemodynamically stable. Vascular leakage of bone cement during injection of a bone cyst is rare but can have catastrophic consequences.

Simple bone cysts have been successfully treated for years using aspiration and injection of bioresorbable bone cement.^1,2 Extravasation of bone cement into the bloodstream has been well described in the literature during vertebroplasty procedures.^3,4 As far as we know, there have been no reports of extravasation of injectable bioresorbable bone cement in the bloodstream during procedures on extremities. In this report we describe a case of bioresorbable bone cement extravasating into the bloodstream after a simple aspiration and injection of a calcaneal bone cyst.

CASE REPORT

A 27-year-old woman with a past medical history of reflex sympathetic dystrophy syndrome presented with worsening left heel pain that affected her ability to do her job and was not relieved by nonsteroidal anti-inflammatory drugs or analgesics. Clinical examination showed global tenderness to palpation around the left calcaneus, normal range of motion, and an inability to bear weight. The neurovascular exam was normal.

Radiographs showed a cystic lesion of the left calcaneus (Figure 1a). Computed tomography (CT) showed a cystic lesion located in the body of the left calcaneus adjacent to the subtalar joint consistent with a simple bone cyst (Figure 1b, 1c). Because of the patient’s inability to bear weight and failure of conservative treatment, we performed a fluoroscopically assisted aspiration and injection of the left calcaneal cyst with demineralized bone graft.

Figure 1.

(a) Lateral x-ray view and (b) coronal and (c) sagittal CT views demonstrating a cyst in the body of the calcaneus.

The patient was positioned supine on a radiolucent table. Intraoperative fluoroscopic assistance was utilized to localize the underlying calcaneal cyst (Figure 2a). Bioresorbable bone cement (CERAMENT™) was prepared and mixed for 5 min. The cyst was then aspirated, and the cement was injected into the cyst. Initially the cyst began to fill with cement (Figure 2b). However, shortly after beginning the injection, the cement began to extravasate into the posterior vein of the ankle (Figure 2c). The injection was immediately stopped. The patient remained hemodynamically stable. No further cement was injected at that point.

Figure 2.

Intraoperative fluoroscopic views of the foot showing (a) the cement syringe entering the calcaneal cyst from a lateral approach, (b) the cement being injected into the calcaneal cyst, and (c) cement extravasating into the posterior vein of the ankle.

DISCUSSION

As with any procedure, injection of cement into a simple bone cyst has multiple reported complications. These complications include, but are not limited to, recurrence of cyst, infection, fracture, skin necrosis, and local extravasation into adjacent joints.^2,5,6 In vertebroplasty, embolism of bone cement has been well described,^7,8 including cases of fatal cement embolism,^9,10 with a vascular cement leakage rate of 16% to 26%.^7,11 No studies have measured the rate of cement leakage during extremity procedures.

In our case, bone cement entered the bloodstream but did not embolize to the heart, as far as we know, and did not cause an acute cardiac event. Since it is possible for cement to enter the bloodstream during this type of procedure, it can be reasonably hypothesized that it could embolize to the heart and lung, causing a cardiopulmonary event. The senior author of this report had a case wherein a proximal humerus bone cyst was aspirated and injected with a similar bioresorbable bone cement product (Beta-bsm^®). Shortly after injecting the cement, it embolized to the heart and led to a fatal cardiopulmonary event. It is unknown whether the event was unique to this cement product or whether it could have happened with any injectable cement. It is possible that a fatal cement embolic event has occurred in the treatment of a simple bone cyst but was not reported.

Cement leakage during bone cyst injection procedures seems to be rare, but leakage combined with embolization can have catastrophic consequences. Additional studies are needed to identify patients at risk of cement embolization. When performing these procedures, we recommend properly mixing the cement and not injecting it before it has time to properly harden. We also recommend using fluoroscopy to actively visualize the injection process and look for any extravasation of cement. Before the injection, the anesthesia team should be notified to look for any acute changes in vital signs. If any cement leakage is seen on fluoroscopy, or if the patient experiences acute changes in vital signs, the procedure should be aborted. We also recommend postinjection imaging of the extremity.