Heightened suspicions are an early tool for treatment of postop spinal infections

View early postoperative pain as a red flag. C-reactive protein tests can point out infections.

Issue: April 2007

Maintaining a high level of suspicion may be a surgeon's best weapon against postoperative spinal infections, according to a spine surgeon.

"You have to make that diagnosis with suspicion of the problem and you cannot bury your head in the sand," Todd J. Albert, MD, said during his presentation at the annual meeting of the North American Spine Society.

"Prevention is obviously key. Remember your antibiotics have to be in and they have to be circulating before you cut the skin," he said. If the patient presents with increased pain in the early postoperative period, the first thing you should do is think about infection. "Rule it out and don't miss it," he said. Albert is a member of the Orthopedics Today Editorial Board.

Preventative steps, such as preoperative antibiotics and intraoperative antimicrobial irrigation, can cut down the odds of infection.

"Preoperative antibiotics are critical and have been shown to make a difference," Albert said.

Preoperative antibiotics

He cited a meta-analysis performed by F. Barker, MD, which pooled data from six randomized prospective trials investigating infection in spinal surgeries.

Barker found a 5.9% rate of infection in cases without antibiotics compared to a 2.2% incidence in those treated with antibiotics.

Recent research also points to the potential role of intraoperative irrigation.

Albert cited a prospective, randomized trial conducted by M.T. Cheng, MD, which found no cases of infection in 208 spinal surgeries using diluted Betadine. Yet, the researchers discovered 14 cases of infection in a comparison group of 206 patients treated with saline.

To adequately diagnosis infections, surgeons should be suspicious.

Albert said that most infections occur within 4 weeks postop and surgeons should remain alert to increased pain and wound problems. " In a patient who's had a discectomy and comes in with increasing back pain, your suspicions should be heightened," Albert said.

Diagnosis

He noted that plain films may not aid in the diagnosis of infection and that CT scans may detect infections too late.

"MRI is the best for diagnosis of postoperative infection with hypo-intensity on the T1 and hyper-intensity on T2-weighted imaging," Albert said.

C-reactive protein testing can also point out infections. Albert highlighted a study by B. Meyer, MD, which found a 2.5% rate of infection in 400 patients who underwent microdiscectomy.

Meyer discovered that C-reactive protein testing showed 100% sensitivity and 95.8% specificity for identifying infection.

The numerous surgical options available to treat infection may leave some surgeons questioning the best modality.

"The answer, at least in my hands, is it depends on what the wound looks like," Albert said. "We do a thorough irrigation and debridement and if it looks pretty good, we'll close it.

"In terms of the principles with retained instrumentation — if you can leave the hardware, leave it," he said.

Albert noted that titanium implants do not develop biofilm. "We recommend removal for recurrent infections, late [and] continual recurrent infections or delayed infections with a solid fusion," he said.

Surgical options

Surgeons can successfully treat deep-instrumented infections with washout techniques, antibiotic irrigation and suction systems or vacuum-assisted wound closures.

In a study of 22 infected instrumented cases, M. Weinstein, MD, successfully salvaged 19 cases using a washout method, Albert said. Surgeons are seeing good results with antibiotic irrigation and suction systems, but Albert warned that the procedure is intense.

"It's a lot of work," he said. "It's a mess, but it can be successful."

Broad spectrum

He prefers to use a vacuum-assisted wound closure technique for recurrent infections or cases with unsuccessful primary closure. "It promotes formation of granulations and the wound heals primarily from the inside out," Albert said. The procedure also allows for fewer returns to the OR.

"In terms of medical treatment, antibiotics are imperative for deep infections," Albert said.

He advised surgeons to start with a broad spectrum of treatments and then narrow down to specific antibiotics. He noted that superficial infections usually last 2 weeks, while deep infections can remain for 6 weeks.

For more information:
Albert TJ, Fassett D. Symposium: Complications in spine care management — Early and late infection ... Prophylaxis, medical and surgical management. Presented at the North American Spine Society 21st Annual Meeting. Sept. 26-30, 2006. Seattle.
Todd J. Albert, MD, The James Edwards Professor and Chairman in the department of orthopedic surgery, professor of neurological surgery, Thomas Jefferson University and Hospital, The Rothman Institute, 925 Chestnut St., Philadelphia, PA 19107; 267-339-3500; tjsurg@aol.com. He has no direct financial interest in the products discussed in this article. He is a paid consultant for and receives royalties and speaking arrangements from DePuy Spine, and is on the scientific advisory boards for Trans1, Gentis and K2 Medical.