The Degree of Bacterial Contamination While Performing Spine Surgery

STUDY DESIGN: Prospective experimental study. PURPOSE: To evaluate bacterial contamination during surgery. OVERVIEW OF LITERATURE: The participants of surgery and ventilation system have been known as the most significant sources of contamination. METHODS: Two pairs of air culture blood agar plate for G(+) bacteria and MacConkey agar plate for G(-) bacteria were placed at 3 different locations in a conventional operation room: in the surgical field, under the airflow of local air conditioner, and pathway to door while performing spine surgeries. One pair of culture plates was retrieved after one hour and the other pair was retrieved after 3 hours. The cultured bacteria were identified and number of colonies was counted. RESULTS: There was no G(-) bacteria identified. G(+) bacteria grew on all 90 air culture blood agar plates. The colony count of one hour group was 14.5+/-5.4 in the surgical field, 11.3+/-6.6 under the local air conditioner, and 13.1+/-8.7 at the pathway to the door. There was no difference among the 3 locations. The colony count of 3 hours group was 46.4+/-19.5, 30.3+/-12.9, and 39.7+/-15.2, respectively. It was more at the surgical field than under the air conditioner (p=0.03). The number of colonies of one hour group was 13.0+/-7.0 and 3 hours group was 38.8+/-17.1. There was positive correlation between the time and the number of colonies (r=0.76, p=0.000). CONCLUSIONS: Conventional operation room was contaminated by G(+) bacteria. The degree of contamination was most high at the surgical field. The number of bacteria increased right proportionally to the time.

Cementless Total Hip Arthroplasty with Fourth Generation Ceramic-on-Ceramic Articulation: Minimum Two Years of Follow-up / 대한고관절학회지

PURPOSE: The purpose of this study is to report clinical and radiographic results over a period of two 2 years after cementless total hip arthroplasty (THA) with fourth generation ceramic-on-ceramic articulation. MATERIALS AND METHODS: We studied 22 patients, 23 cases which were followed up for two years among 25 patients, 26 patients who underwent cementless THA with the fourth generation ceramic between April 2009 and December 2009. The average age of the patients was 55.9 years old(22 to 72 years old), and the average follow-up duration was 28 months(24 to 32 months). A clinical evaluation was performed using the Harris hip score (HHS), and radiologic evaluation was based on acetabular cups and osteolysis of the femoral stems, instability, distance, angle, and so on. RESULTS: HHS showed an increase, from 54 for before-surgical treatment, to 91 at the last follow-up. Inguinal pain was observed in one case, and femoral pain was observed in two cases. Stable fixation was achieved in all cases, and no instability, osteolysis, or movement of acetabular cups and femoral stems was observed. CONCLUSION: Clinical and radiological short-term results for use ofthe fourth generation ceramic-on-ceramic cementless THA have favorable so far. Further follow-up study should be performed for evaluation of the long-term results.

Relationship between the Tourniquet Pressure and the Amount of Subcutaneous Bleeding after Total Knee Replacement

PURPOSE: We wanted to evaluate the post-operative amount of subcutaneous bleeding according to the tourniquet pressure during total knee replacement. MATERIALS AND METHODS: We analyzed 136 patients who had undergone total knee replacement at our hospital from March 4th, 2010 to September 16th, 2010. A tourniquet pressure of 250 mm Hg was applied to 69 patients (group I) and a tourniquet pressure of 320 mm Hg was applied to the other 67 patients (group II). Subcutaneous bleeding was evaluated on the 3rd and 6th days after the operations. All of the total knee replacements were performed by a single surgeon. RESULTS: Among the group I patients, subcutaneous bleeding was seen in just 2 patients, yet among the group II patients, there were 32 patients with subcutaneous bleeding on the 3rd day and 33 patients with subcutaneous bleeding on the 6th day. According to the multiple regression analysis, there were no significant differences in ages, the tourniquet time and the orders between the two groups. Group 1 had significantly less subcutaneous bleeding than did group II on the 3rd and 6th days after the operations (p=0.001). CONCLUSION: There was a significant difference of the amount of subcutaneous bleeding amount according to the tourniquet pressure. We were able to decrease the post-operative amount of subcutaneous bleeding after total knee replacement by lowering the tourniquet pressure to 250 mm Hg.

The Oblique Proximal Interlocking Screw for Intramedullary Nailing Proximal Tibial Fractures: Is It Safe? / 대한정형외과학회잡지

PURPOSE: We tried to reveal radiographic clues for the possibility of damages to the important structures, including the peroneal nerve and the anterior tibial artery, caused by a proximal interlocking screw with a medial to lateral oblique direction (ObML-PIS). MATERIALS AND METHODS: The length of the proximal tibiofiular joint (PTFJ) was measured from the tip of the fibular head to the end of PTFJ on the simple oblique radiographs of 22 cases of tibial intramedullary (IM) nailing. The center (O) of the IM nailing, from the tibial anterior cortex at the level of insertion of an ObML-PIS, was measured on the simple lateral radiographs. The angle POA (P: a point 10 mm anterior from the anterior fibular border, A: a point on the tangent line from the O point to the posteromedial cortex of the fibula) was measured on the MR axial view of 60 cases, and within this angle an ObML-PIS could injure the important anatomical structures. Transverse and 45-degree oblique diameters of the proximal tibia on the MR axial view were also measured. RESULTS: The PTFJ length was 18.5+/-3.3 mm and the O point was located at 15.3+/-3.4 mm posterior from the tibial anterior cortex. The angle POA was 21.4+/-6.2-67.8+/-6.7 degrees with medial to lateral oblique directions. The transverse diameter of the proximal tibia was 58.0+/-5.8 mm and the 45-degree oblique diameter was 50.7+/-6.2 mm. CONCLUSION: Special caution may be needed when we use an ObML-PIS because it is located at the level distal from the end of the PTFJ and within the POA angle, and the peroneal nerve and anterior tibial artery can possibly be severed.

Treatment for Periprosthetic Supracondylar Femur Fractures Following Total Knee Arthroplasty -Comparative Study of Retrograde Intramedullary Nailing and Locking Compression Plate Fixation-

PURPOSE: The purpose of this research is to compare the clinical and radiological results of retrograde intramedullary nailing and locking compression plate fixation. Both of these are surgical procedures for the treatment of periprosthetic supracondylar femur fractures that occur subsequent to total knee arthroplasty. MATERIALS AND METHODS: The subject population consisted of 23 cases: there were 10 cases that underwent retrograde intramedullary nailing fixation (group 1) and 13 cases that underwent use of a locking compression plate (group 2), and in both groups supracondylar femur fracture subsequent to total knee replacement occurred during the period between January 2004 and December 2008. The range of joint motion, the Hospital for Special Surgery (HSS) knee score, the tibio-femoral angle and the time to achieve bone union in each group were comparatively analyzed. RESULTS: The mean range of the knee joint motion decreased from 124.5degrees to 116.2degrees in group 1, and from 118.2degrees to 110.1degrees in group 2. The mean HSS knee score declined from 84.4 points to 75.8 points in group 1, and from 82.3 points to 79.0 points in group 2. The mean tibio-femoral angle changed from 6.3degrees eversion to 5.8degrees in group 1, and from 6.1degrees to 7.2degrees in group 2. The mean time to achieving bone union was 2.7 months in group 1 and 3 months in group 2. CONCLUSION: Both retrograde intramedullary nailing and locking compression plate fixation, as surgical procedures for the treatment of periprosthetic supracondylar femur fractures that occur subsequent to total knee replacement, allow solid fixation and early resumption of joint movement without any statistically significant differences between the two procedures. So, both procedures appear to be good methods of treatment.

Precautions Against Infection Following Posterior Spinal Fusion Based on Types of Infection and Risk Factors / 대한척추외과학회지

STUDY DESIGN: This is a retrospective preparative study and prospective study OBJECTIVE: We instituted and verified the precautions against postoperative spinal infection. SUMMARY OF THE LITERATURE REVIEW: Postoperative infection comes from contamination during the operation and various strategies have been recommended to prevent it. MATERIALS AND METHODS: 583 cases that underwent instrumented posterior spinal fusion during two years (group I), were reviewed to discover the risk factors, and intraoperative cultures were done to detect the contamination routes and the causative microorganisms for the next 4 months. Six precautions, based on the results, were instituted. We analyzed 354 cases that underwent operation in the following year (group II) using the precautions. RESULTS: Twenty cases (3.4%) were infected in group I and the types of infection were superficial wound infection (4 cases), deep wound infection (4 cases), osteomyelitis around the interbody space (7 cases), osteomyelitis around the pedicle screws (4 cases) and a combination of wound infection and osteomyelitis around the pedicle screws (1 case). Infections happened more frequently in the cases of interbody fusion (p=0.034), revision (p=0.087) and those done in the summer season (p=0.025). S. epidermidis, as the causative bacteria, was cultured from both the operation environments and wounds. Six precautions based on the preliminary results were instituted as follows; irrigation method reformation, delayed opening of instruments, turning-off local air conditioners, changing of gowns before instrumentation, local bone irrigation and limited indications for interbody fusion. After implementation, two cases (0.6%) of infection developed in group II (p=0.002, odds ratio=0.160; 95% confidence interval = 0.037 to 0.688). CONCLUSION: Wounds, grafted bones or instruments can be contaminated under longer-time exposure to operating room air and so produce interbody or pedicle osteomyelitis without wound infection. The precautions were effective to decrease the postoperative infection rates following posterior spinal fusion.