PURPOSE: The purpose of this study is to examine the effect of various preoperative risk factors on postoperative complications after paraspinous muscle flap reconstruction of non-healing back wounds. As one of thirteen spinal cord injury centers in the United States, exposure to complicated spinal problems is common. With increasingly complex spine surgeries now performed on a more comorbid patient population, the reconstruction of midline back wounds from these procedures is becoming a frequent dilemma encountered by plastic surgery.
METHODS: An 11-year retrospective office and hospital chart review was conducted between July 1996 and August 2007. All patients who underwent reconstruction using paraspinous muscle flaps during this time period were included. There were 92 patients in the study, representing the largest reported series to-date for this procedure.
RESULTS: Over an 11-year period, 92 patients underwent spinal wound reconstruction using the paraspinous muscle flap technique. Mean length of follow up was 120 days. Wound complications necessitating reconstruction included infection (75/92; 82%), dehiscence (16/92; 17%), seroma (10/92; 11%), and hematoma (6/92; 7%). 23 patients (25%) developed a post-flap wound complication and 15 patients (16%) developed a post-flap wound complication requiring hospital admission. Post-flap complications included infection (12/92; 13%), seroma (11/92; 12%), hematoma (1/92; 1%), and dehiscence (1/92; 1%). Preoperative risk factors and their associated complication rate are described in Table 1. Risk factors associated with a statistically significant (p<.05) increased rate of post-flap wound complication included emergent initial spine surgery, a history of more than two spine surgeries, hypertension, radiation to the wound area, smoking, a history of quadriplegia, and lumbosacral wound location. Malnutrition (albumin<3.5), obesity, chronic steroid use, anemia, and diabetes were not associated with a significantly increased rate of post-flap wound complications. 86/92 (93%) patients undergoing wound reconstruction had initial spine surgery requiring hardware. Patients who retained their hardware (50/86) had significantly fewer post-flap complications compared to patients who had their hardware removed pre-flap (26/86) (14% vs. 31%; p<.001). Patients with retained hardware had a shorter length of stay compared to patients whose hardware was removed (19 vs. 23 days).
CONCLUSION: This patient population possesses multiple comorbidities making complex wound healing difficult. Several specific risk factors are associated with an increased rate of post-reconstruction wound complication. From a plastic surgery perspective, an attempt should be made to salvage hardware with the use of paraspinous muscle flaps, as salvage is associated with fewer post-flap wound complications and a shorter length of stay.

> >Table 1: Odds Ratio and Rate of Complication associated with various preoperative wound healing risk factors