The most common adverse events associated with spine surgery include neurologic injury, infection, re-operation, medical complications, and dural tear.1 Of these, infection is the most frequently studied and reported both in the literature and within healthcare delivery organizations. Infection rates for lumbar spine surgery are frequently reported between 3% to 5% in many studies, but have a wide range depending on the type of procedure performed. Studies have reported an infection rate of 1% or less in single-level micro-discectomy cases (a small decompression procedure for disc herniation with sciatic pain); 3% to 7% in instrumented fusion cases (a stabilization procedure usually involving one to two levels for back pain or instability); 7% to 10% in adult deformity reconstruction (procedures to realign the spine in patients with scoliosis/kyphosis); and greater than 20% in neuromuscular deformity cases.1,2,3,4
In 2011, a total 370,000 discectomy and 498,700 fusion/refusion procedures were performed. Based on conservative estimated infection rates of 1% and 5%, for discectomy and fusion/refusion, respectively, we can estimate there were 28,600 postoperative spine infections. It is unknown what proportion of spinal infection diagnosis-related health care visits this represents. (Reference Table 2.14 PDF [1] CSV [2] and Table 2.19 PDF [3] CSV [4])
Risk factors associated with postsurgical complications and infection following spine surgery include obesity, diabetes, steroid and alcohol use, revision surgery, age, and operative time and blood loss. Postsurgical wound infections can arise from direct inoculation of the wound intra-operatively or indirectly by hematogenous seeding from other sources (ie, spread through the bloodstream). The most frequent organism cultured is Staphylococcus aureus (Staph infection), while gram-negative organisms are more commonly seen in polymicrobial infections (infections involving multiple types of bacteria).1
The most frequently reported symptoms are back pain, fever, and wound drainage, usually within the first 10-20 days of surgery, although latent infections may occur more than one year from surgery.
Superficial infections are frequently managed with oral antibiotics, while deep infections typically require surgical debridement (removal of dead, damaged, or infected tissue) and IV antibiotics. A small percentage of infections may be complicated by large soft tissue defects and compromised host immune systems, requiring extensive and prolonged treatments and surgical procedures.
Although major complications are rare, they are more likely to be seen in patients with complicated cases and have been reported to occur in as many as 28% to 32% of adult deformity cases.1 These include complications that are device-related (2% to 5%), neurologic (1% to 2%), vascular (3% to 4%), medical (>10%), stroke (2%), and include death (0.8%).1,2 Sentinel events (relatively infrequent, clear-cut events that occur independently of a patient's condition), including bowel or peritoneal injury, neurovascular injury, wrong site surgery, and retention of a foreign body, occur in 0.8/1,000 cases.3
Both major complications and sentinel events frequently require further medical interventions, resulting in longer hospitalizations, greater costs, and increased mortality.
Links:
[1] https://www.boneandjointburden.org/docs/T2.14.pdf
[2] https://www.boneandjointburden.org/docs/T2.14.csv
[3] https://www.boneandjointburden.org/docs/T2.19.pdf
[4] https://www.boneandjointburden.org/docs/T2.19.csv