Magnetic resonance evaluation in long term follow up of operated lateral tibial plateau fractures.

BACKGROUND: A lack of data exists on the long-term magnetic resonance imaging (MRI) findings after surgical repair of tibial plateau fractures (TPFs). We evaluated the MRI findings 13 to 31 years after surgical repair of TPFs, focusing especially on the pathological changes in the ligaments, menisci, and cartilage. METHODS: Twenty-three patients with 24 TPFs underwent open reduction and internal fixation with the same fork-shaped surgical plate that was used in our institution until 1999. No patient underwent preoperative or immediately postoperative MRI. The knees of all patients who underwent plate removal were examined by axial, coronal, and sagittal MRI. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and whole-organ magnetic resonance score (WORMS) were determined in all patients. RESULTS: All 24 knees exhibited MRI abnormalities. An unexpectedly high number of pathological changes in the menisci and ligaments were observed. No meniscal or ligamentous injuries were documented at the time of the injury or initial surgery, but meniscal injuries manifested in the long term. MRI in almost all cases showed a damage to the lateral meniscal, the severity of which was related to the degree of tibial plateau widening, but not to the severity of the lateral joint surface impression. The overall condition of the knee joint was satisfactory as measured by the WORMS, and there was a weak correlation between WORMS and KOOS.

Radiographic and clinical results after surgically treated tibial plateau fractures at three and twenty two years postsurgery.

PURPOSE: We examined the development of osteoarthritis (OA) and post-traumatic bone loss after surgery for tibial plateau fractures (TPF). METHODS: Patients who had participated in previous follow-up (FU) examinations after TPF and primary reduction and internal fixation were re-evaluated. At the first FU, a median of three years after the accident (short-term FU), the patients underwent functional assessments and standardised X-rays to grade radiological OA and post-traumatic bone loss. At the second FU, a median of 22 years after the accident (long-term FU), 30 patients were available. An identical protocol was applied, and additional investigations [Knee Injury and Osteoarthritis Outcome Score (KOOS) and magnetic resonance imaging (MRI) of the injured knee] were performed. RESULTS: When the subjective and objective results at first FU were compared with those of the second FU for the same patients, deterioration of symptoms, signs and radiological OA was noted; however, ten patients had no OA even after the long-term FU. Some patients developed post-traumatic bone loss. In 13 of 31 knees, there was little or no radiological evidence of bone loss at the second FU. CONCLUSIONS: The short-term FU examination results after TPF have little prognostic value for the individual patient, as good results may deteriorate over the long run; however, there were some knees with no OA at the long-term FU. This is the first report focusing on post-traumatic bone loss after TPF.

Increased circulating D-lactate levels predict risk of mortality after hemorrhage and surgical trauma in baboons.

Patients with hemorrhagic shock and/or trauma are at risk of developing colonic ischemia associated with bacterial translocation that may lead to multiple organ failure and death. Intestinal ischemia is difficult to diagnose noninvasively. The present retrospective study was designed to determine whether circulating plasma D-lactate is associated with mortality in a clinically relevant two-hit model in baboons. Hemorrhagic shock was induced in anesthetized baboons (n = 24) by controlled bleeding (mean arterial pressure, 40 mmHg), base excess (maximum -5 mmol/L), and time (maximum 3 h). To mimic clinical setting more closely, all animals underwent a surgical trauma after resuscitation including midshaft osteotomy stabilized with reamed femoral interlocking nailing and were followed for 7 days. Hemorrhagic shock/surgical trauma resulted in 66% mortality by day 7. In nonsurvivor (n = 16) hemorrhagic shock/surgical trauma baboons, circulating D-lactate levels were significantly increased (2-fold) at 24 h compared with survivors (n = 8), whereas the early increase during hemorrhage and resuscitation declined during the early postresuscitation phase with no difference between survivors and nonsurvivors. Moreover, D-lactate levels remained elevated in the nonsurvival group until death, whereas it decreased to baseline in survivors. Prediction of death (receiver operating characteristic test) by D-lactate was accurate with an area under the curve (days 1-3 after trauma) of 0.85 (95% confidence interval, 0.72-0.93). The optimal D-lactate cutoff value of 25.34 µg/mL produced sensitivity of 73% to 99% and specificity of 50% to 83%. Our data suggest that elevation of plasma D-lactate after 24 h predicts an increased risk of mortality after hemorrhage and trauma.

Reconstruction of the anterior cruciate ligament: a clinical comparison of bone-patellar tendon-bone single bundle versus semitendinosus and gracilis double bundle technique.

The study hypothesis was that the outcome of semitendinosus gracilis double bundle (STG-DB) anterior cruciate ligament (ACL) reconstruction is advantageous in terms of clinical results and restoration of anterior-posterior and rotational laxity in comparison to bone-patellar tendon-bone single-bundle (PTB-SB) ACL reconstruction. We analysed 41 PTB-SB and 51 STG-DB patients using the Tegner, IKDC and WOMAC scores preoperatively and at a minimum follow-up of two years. At follow-up, there was no significant difference in the clinical scores. The KT 1000 side-to-side measurement showed no significant difference between groups. The STG-DB group was significantly superior in terms of the pivot-shift sign and anterior knee pain. We conclude that the outcome of STG-DB reconstruction in the mid-term was not advantageous in terms of clinical scores and anterior-posterior laxity evaluated by the KT 1000. Nevertheless, the restored rotational laxity measured by the pivot shift test was significantly superior in the STG-DB technique.

Impact of tibial and femoral tunnel position on clinical results after anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to correlate anatomic and nonanatomic tibial and femoral tunnel positions after anterior cruciate ligament (ACL) reconstruction with clinical outcome by use of bone-patellar tendon-bone (BPTB) single-bundle (SB) and semitendinosus-gracilis (STG) double-bundle (DB) techniques. METHODS: The 3-dimensional computed tomography scans of 53 patients' knees (27 BPTB-SB and 26 STG-DB) were prepared and measured by 2 examiners according to their tibial and femoral tunnel positions. We evaluated these radiologic constructions and measurements by use of the Cohen κ interobserver and intraobserver coefficient for 2 observers. Patients undergoing both techniques were divided into anatomic and nonanatomic reconstructions according to the findings of Zantop and Petersen. We correlated anatomically and nonanatomically reconstructed patients with clinical outcome by the Tegner score, Western Ontario and McMaster Universities Osteoarthritis Index score, International Knee Documentation Committee score, KT-1000 arthrometer (MEDmetric, San Diego, CA), and pivot-shift test in both techniques. RESULTS: The radiologic constructions and measurements of 53 computed tomography scans were achieved with a good agreement of interobserver and intraobserver coefficients for 2 observers. We found significantly superior clinical outcome in anatomic ACL reconstructions in both techniques in terms of higher clinical scores (Tegner and International Knee Documentation Committee), higher anterior posterior stability, and less pivot shift. We observed the best outcome in anatomic STG-DB reconstructions. CONCLUSIONS: This investigation showed that better clinical results are associated with anatomic ACL reconstructions. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Rinsing-suction reamer attenuates intramedullary pressure increase and fat intravasation in a sheep model.

BACKGROUND: Reamed intramedullary nailing causes an increase of intramedullary pressure. A new rinsing-suction reamer (RSR) can reduce this problem, and it was evaluated in animal experiments in comparison with the AO reamer (AOR) to see its effects on intramedullary pressure and fat intravasation. METHODS: Reamed intramedullary nailing was performed in 14 sheep using the RSR or AOR. The following parameters were evaluated: intramedullary pressure, hemodynamics, blood tests, lung histology, and radiographs of the femur that was operated on. RESULTS: Intramedullary pressure during reaming was significantly (p < 0.001) lower with RSR (9 mm, 34 mm Hg; 9.5 mm, 4 mm Hg; 10 mm, 1 mm Hg) than AOR (9 mm, 750 mm Hg; 9.5 mm, 292 mm Hg; 10 mm, 138 mm Hg). There was a significantly (p < 0.05) higher increase of pulmonary resistance in AOR (from 144 +/- 84 dyne x s x cm to 391 +/- 169 dyne x s x cm) than in RSR (from 137 +/- 51 dyne x s x cm to 258 +/- 105 dyne x s x cm) after nailing and less intravenous fat measured in RSR (0.9; AOR, 2.9; p < 0.05) at all stages of reaming, at nail insertion (RSR, 0.3; AOR, 2.7; p < 0.05), and 30 seconds after nail insertion (RSR, 0.2; AOR, 1.1; p < 0.05) proved by the Gurd test. Pco2 increased (p < 0.05) in AOR (AOR, 36 +/- 5 vs. 40 +/- 7 mm Hg; RSR, 33 +/- 4 vs. 32 +/- 3 mm Hg) and pH dropped significantly (AOR, 7.49 +/- 0.06 vs. 7.45 +/- 0.05; RSR, 7.53 +/- 0.04 vs. 7.54 +/- 0.04; p < 0.05). Semiquantitative histologic analysis proved a significant higher pulmonary fat load in AOR (13.1 +/- 13.4) versus RSR (3.9 +/- 1.5, p = 0.00002). CONCLUSION: Because we found only a minimal increase of the pulmonary arterial pressure as a sign of pulmonary embolism, we conclude that by using the RSR, the systemic side effects caused by intravasation of medullary content during reaming could be reduced as far as possible.

[Alternatives to laboratory animals in microsurgical training]

Aim of this present literature-study is to show the possibilities of reduction and replacement of laboratory animals in education and training in microsurgical techniques. Laboratory animals have been the standard model for a microsurgical unit. In the last years some publications about the use of alternatives to laboratory animals can be found. Microsurgical techniques are used in almost all surgical disciplines and so there is an enormous importance for the clinical work. Because of the increasing sensibility of the public animal welfare has a higher rank now. Furthermore ethical viewpoints are more important for research, science, and medical and biomedical education. The necessity of laboratory animals for education and training in microsurgical techniques is discussed. Furthermore there are alternatives to laboratory animals described.