Effect of forced-air warming blanket position in elective lumbar spine surgery: Intraoperative body temperature and postoperative complications.

BACKGROUND: Perioperative hypothermia is linked to multiple postoperative complications including increased surgical bleeding, surgical site infection, myocardial events, and increased length of hospital stay. The purpose of this study is to determine the effects of forced-air warming blanket position, above the shoulders versus under the trunk/legs, on intraoperative core body temperature and perioperative complications in elective lumbar spine surgery. METHODS: After IRB approval, patients were enrolled in a consecutive fashion and randomized to either upper body (Group I) or lower body (Group II) groups. Primary outcomes were intraoperative body temperature, incidence of hypothermia, postoperative complications, and infection. Secondary outcomes included blood loss, operative time, and length of stay. RESULTS: Seventy-four patients were included (Group I, 38; Group II, 36, mean age 60.7 years, 54% of male). Average patient follow-up was 69 ± 33.6 days in Group I and 67 ± 34.6 days in Group II. Average intraoperative body temperature was 35.7 in Group I and 35.8 in Group II (P = 0.27). Incidence of critical hypothermia (T < 35°C) was 18.4% and 11.1% in Groups I and II, respectively (P = 0.52). Incidence of mild hypothermia (T: 35°C-36°C) was 34.2% and 30.56% in Groups I and II, respectively (P = 0.81). Separately, pooled analysis comparing average body temperature and incidence infection demonstrated a relationship between mild hypothermia and infection (P = 0.03). CONCLUSION: Compared to using a lower body Bair Hugger under the patient, using standard upper body Bair Hugger may be associated with increased surgical site infection. Given equivalent body warming, we recommend using the lower body Bair Hugger to avoid infection.

Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis.

OBJECTIVE The inability to significantly improve sagittal parameters has been a limitation of minimally invasive surgery for transforaminal lumbar interbody fusion (MIS TLIF). Traditional cages have a limited capacity to restore lordosis. This study evaluates the use of a crescent-shaped articulating expandable cage (Altera) for MIS TLIF. METHODS This is a retrospective review of 1- and 2-level MIS TLIF. Radiographic outcomes included differences in segmental and lumbar lordosis, disc height, evidence of fusion, and any endplate violations. Clinical outcomes included the numeric rating scale for leg and back pain and the Oswestry Disability Index (ODI) for low-back pain. RESULTS Thirty-nine patients underwent single-level MIS TLIF, and 5 underwent 2-level MIS TLIF. The mean age was 63.1 years, with 64% women. On average, spondylolisthesis was corrected by 4.3 mm (preoperative = 6.69 mm, postoperative = 2.39 mm, p < 0.001), the segmental angle was improved by 4.94° (preoperative = 5.63°, postoperative = 10.58°, p < 0.001), and segmental height increased by 3.1 mm (preoperative = 5.09 mm, postoperative = 8.19 mm, p < 0.001). At 90 days after surgery the authors observed the following: a smaller postoperative sagittal vertical axis was associated with larger changes in back pain at 90 days (r = -0.558, p = 0.013); a larger decrease in spondylolisthesis was associated with greater improvements in ODI and back pain scores (r = -0.425, p = 0.043, and r = -0.43, p = 0.031, respectively); and a larger decrease in pelvic tilt (PT) was associated with greater improvements in back pain (r = -0.548, p = 0.043). For the 1-year PROs, the relationship between the change in PT and changes in ODI and numeric rating scale back pain were significant (r = 0.612, p = 0.009, and r = -0.803, p = 0.001, respectively) with larger decreases in PT associated with larger improvements in ODI and back pain. Overall for this study there was a 96% fusion rate. Fourteen patients were noted to have endplate violation on intraoperative fluoroscopy during placement of the cage. Only 3 of these had progression of their subsidence, with an overall subsidence rate of 6% (3 of 49) visible on postoperative CT. CONCLUSIONS The use of this expandable, articulating, lordotic, or hyperlordotic interbody cage for MIS TLIF provides a significant restoration of segmental height and segmental lordosis, with associated improvements in sagittal balance parameters. Patients treated with this technique had acceptable levels of fusion and significant reductions in pain and disability.

A biomechanical comparison of subscapularis repair techniques in total shoulder arthroplasty: lesser tuberosity osteotomy versus subscapularis peel.

BACKGROUND: The subscapularis peel (SP) and the lesser tuberosity osteotomy (LTO) are 2 common exposure techniques for total shoulder arthroplasty. Although some biomechanical studies have suggested a higher resistance to failure with the LTO, clinical studies have demonstrated no difference in repair failure or tendon healing. We hypothesized that there would be no difference in biomechanically tested repair strength between our SP technique and the previously tested LTO technique. METHODS: Eleven cadaver shoulders were separated into 2 groups: 6 SPs and 5 LTOs. After initial loading for 3000 cycles, the specimens were incrementally loaded to 450 ± 50 N or catastrophic failure. Repair gapping was measured after cyclical loading, and fatigue life was analyzed after incremental loading. RESULTS: There was no significant difference in mean repair gapping between the SP (2.40 ± 0.36 mm; mean ± standard deviation) and the LTO groups (3.10 ± 2.93 mm; P = .57). There was also no difference in the mean number of cycles to failure (6894 ± 956 vs. 6018 ± 1179; P = .14) and mean load to failure (400 ± 79 N vs. 340 ± 91 N; P = .21) between the SP and LTO techniques. However, there was more variability in bead gapping in the LTO group (P < .01). CONCLUSION: No significant differences were found in repair gapping, fatigue failure, and load to failure in comparing the SP and LTO repairs. However, the SP repair demonstrated significantly less variability in repair gapping. These findings suggest that initial fixation biomechanical properties between the 2 constructs are similar in vitro.