CRP and leukocyte-count after lumbar spine surgery: fusion vs. nucleotomy.

BACKGROUND: Despite the fact that C-reactive protein (CRP) levels and white blood cell (WBC) count are routine blood chemistry parameters for the early assessment of wound infection after surgical procedures, little is known about the natural history of their serum values after major and minimally invasive spinal procedures. METHODS: Pre- and postoperative CRP serum levels and WBC count in 347 patients were retrospectively assessed after complication-free, single-level open posterior lumbar interlaminar fusion (PLIF) (n = 150) for disc degeneration and spinal stenosis and endoscopically assisted lumbar discectomy (n = 197) for herniated lumbar disc. Confounding variables such as overweight, ASA classification, arterial hypertension, diabetes mellitus, and perioperative antibiotics were recorded to evaluate their influence on the kinetics of CRP values and WBC count postoperatively. RESULTS: In both procedures, CRP peaked 2-3 days after surgery. The maximum CRP level was significantly higher after fusion: mean 127 (SD 57) (p < 0.001). A rapid fall in CRP within 4-6 days was observed for both groups, with almost normal values being reached after 14 days. Only BMI > 25 and long duration of surgery were associated with higher peak CRP values. WBC count did not show a typical and therefore interpretable profile. CONCLUSION: CRP is a predictable and responsive serum parameter in postoperative monitoring of inflammatory responses in patients undergoing spine surgery, whereas WBC kinetics is unspecific. We suggest that CRP could be measured on the day before surgery, on day 2 or 3 after surgery, and also between days 4 and 6, to aid in early detection of infectious complications.

An animal model to study ACL reconstruction during growth.

Controversy exists in the literature regarding the most appropriate treatment for anterior cruciate ligament (ACL) ruptures in the skeletally immature patient. To study the histological and biomechanical stages following ACL reconstruction during growth, it is necessary to establish an equivalent model to replicate the situation of an immature skeleton. In the present study we evaluated a large animal model of ACL reconstruction during growth using skeletally immature sheep. In contrast to existing models we did not intend to provoke growth disturbances. Instead, we identified those criteria known to be essential to prevent growth disturbances in the human situation and transformed them into an animal model. Applying those criteria to skeletally immature sheep at an age of four months, we performed a fully transphyseal ACL reconstruction of their right knee. The contralateral knee served as a control. The sheep were then sacrificed 3, 6, 12 and 24 weeks after surgery. This animal model is described in detail in the present manuscript. Basic science data are presented in order to 1) make it easier for other research groups to study ACL reconstruction during growth using our model and 2) to improve this model by modifying the one or other detail of the proposed technique. Using this model, remaining open questions concerning ACL reconstruction during growth can be addressed in future studies.