Calcium sulphate has been used extensively as a bioabsorbable
bone substitute for 90 years. Its advantages include its low cost, ready availability and unlimited supply, lack of donor site morbidity, use as a delivery vehicle for other compounds (especially
antibiotics), inherent osteoconductive properties (based on a structure similar to bone), and its proven safety record. We sought to determine the evidence-based medical studies (prospective and/or randomized clinical trials) that support the use of
calcium sulphate as a bioabsorbable
bone substitute. At the present time, the majority of reports are basic science investigations, animal studies, and retrospective clinical reviews of varying degrees of quality. Multiple retrospective reviews reveal that
calcium sulphate is an effective void-filler in contained bony defects such as metaphyseal voids after impacted
fracture reduction (calcaneus, tibial plateau), simple
bone cysts, or posttraumatic defects. Three case series examining the use of
calcium sulphate in the treatment of bone nonunions revealed a significant failure rate, suggesting that this material, used in isolation, is not optimal to promote union in that setting. A low but consistent complication rate, specifically serous drainage from the
wound as the
calcium sulphate absorbs, has been reported. This complication is higher when the material is used in higher volumes (greater than 20 mL) or in subcutaneous bones (tibia, ulna). There is some Level I to II evidence (one randomized trial, one case-control study, one prospective cohort study) that
antibiotic-impregnated bioabsorbable
calcium sulphate has the potential to reduce the number of procedures and surgical morbidity associated with the surgical treatment of chronic
osteomyelitis and infected nonunion while maintaining a high rate of
infection eradication.
Calcium sulphate remains an inexpensive, safe, reliable bone void filler that can also serve as a absorbable delivery vehicle for
antibiotics or other compounds. Further high-quality randomized and prospective clinical trials are required to define the role of
calcium sulphate in modern orthopaedics.