Bone Cement Implantation Syndrome (BCIS)

Introduction

Bone CementBone cement is polymethyl methacrylate (PMMA), the same polymer used to make acrylic glass (sold under brand names such as Plexiglas). Implantation Syndrome (BCIS, historically also known as Palacos reaction) is a complication that can occur during both cemented and uncemented arthroplasty that "comprises the occurrence of hypoxaemia, hypotension, unexpected loss of consciousness, or cardiac arrest occurring around the time of cementation, prosthesis insertion, or reduction of the joint in arthroplasty".Bone cement implantation syndrome: a scoping review by Brokke KE et al., DOI: 10.1016/j.bja.2025.05.041

This post summarizes key points of the following two papers:

• Bone cement implantation syndrome: a scoping review by Brokke KE et al., DOI: 10.1016/j.bja.2025.05.041
• Bone Cement and Its Anesthetic Complications: A Narrative Review by Al-Husinat L et al., DOI: 10.3390/jcm12062105

Pathophysiology

The pathophysiology of BCIS is not yet fully understood and likely multicausal. Discussed theories include:

1. Vasodilatation induced by methyl methacrylate (MMA) monomers. (demonstrated only in vitro; not reproducible in vivo)
2. Embolic events due to fat, air, bone marrow, thrombus, mechanical effects, etc. (can occur during both cemented and uncemented prosthesis insertion/reduction)
3. Anaphylactic reaction with histamine release
4. Activation of complement factors C3a and C5a

Severity classification

BCIS is classified according to the severity of symptoms as defined by Donaldson AJ et al.Bone cement implantation syndrome by Donaldson AJ et al., DOI: 10.1093/bja/aen328:

• Grade 1: moderate hypoxaemia (SpO2 < 94%) or hypotension (decrease in systolic blood pressure (SBP) > 20%)
• Grade 2: severe hypoxaemia (SpO2 < 88%) or hypotension (decrease in SBP > 40%) or unexpected loss of consciousness
• Grade 3: cardiovascular collapse requiring CPR

The scoping review by Brokke KE et al. proposes "incorporating a relative MAP decrease in the classification: a 15% decrease for BCIS grade 1 and a 30% decrease for BCIS grade 2."

Risk factors

• Advanced age
• ASA 3 or 4 status
• Osteoporosis or bone metastases
• Pulmonary hypertension, COPD or lung cancer/metastases
• Pre-existing cardiopulmonary or renal impairment

Incidence

Incidence varies greatly between different arthroplasty procedures and studies.What Are the Frequency, Related Mortality, and Factors Associated with Bone Cement Implantation Syndrome in Arthroplasty Surgery? by Rassir R et al., DOI: 10.1097/CORR.0000000000001541 BCIS is more likely to occur in cemented hip hemiarthroplasty or knee arthroplasty, less likely during shoulder arthroplasty or uncemented procedures. Cancer patients can be at particular risk, possibly due to hypercoagulability.

Prevention

• Closely monitor capnography and arterial blood pressure
• Increase FiO2 to 100% before/during cementation (increase oxygen reserve, prevent hypoxic pulmonary vasoconstriction, reduce RV load)
• Maintain normovolemia (ensure good perfusion of right ventricle during increased load)
• Have vasopressors (e.g. noradrenaline, adrenaline) at hand

Surgical prevention includes medullary lavage, retrograde cement insertion, vacuum-mixed cement, etc.