General, spinal or regional anaesthesia does not affect strength performance 6 months after ACL reconstruction

PURPOSE

The recovery of strength is a key element in successfully returning to sports after ACL reconstruction. The type of anaesthesia has been suspected an influential factor in the post-operative recovery of muscle function.

METHODS

In this retrospective analysis, n = 442 consecutive patients undergoing primary isolated ACL reconstruction using a hamstring autograft were analysed by pre- and post-operative isokinetic tests in a single orthopaedic centre. These were subdivided into four cohorts: (1) general anaesthesia (n = 47), (2) general anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 37), (3) spinal anaesthesia (n = 169) and (4) spinal anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 185). Primary outcome was the change from pre- to post-operative isokinetic strength during knee extension and flexion.

RESULTS

Using one-way ANOVA, there was no significant influence of the type of anaesthesia. The main effect of anaesthesia on change in extension forces was not significant, and effect sizes were very small (n.s.). Similarly, the main effect of anaesthesia on change in flexion forces was statistically not significant (n.s.).

CONCLUSIONS

The findings of this study support the interpretation that the type of anaesthesia has no significant effect on the ability to recover thigh muscle strength 6 months after isolated hamstring ACL reconstruction. With regard to the recovery of athletic performance and return-to-sports testing criteria, there is no reason to avoid regional anaesthesia.

LEVEL OF EVIDENCE

III.

Relationship between pre- and post-operative isokinetic strength after ACL reconstruction using hamstring autograft

BACKGROUND

Anterior cruciate ligament (ACL) ruptures are of major concern in sports. As mostly young and active individuals are affected there is an emphasis on the rapid and safe return to sports (RTS). Strengthening the ventral and dorsal thigh muscles is a prerequisite for a successful RTS after ACL reconstruction (ACLR), as persistent muscle weakness may increase the incidence for secondary injuries and impair performance. Aiming to increase evidence on the importance of preoperative muscle strength and the coaching of patients, the purpose of this study is to compare thigh muscle strength pre- and post-operatively after ACLR.

METHODS

We performed a retrospective analysis of 80 patients with primary, isolated ACLR using a four-stranded hamstring autograft. We performed bilateral isokinetic concentric strength measurement (60°/s) before and six months after ACLR. Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q ratio) and the corresponding limb symmetry indices (LSI). Pearson correlations were calculated for pre- and post-surgical values.

RESULTS

The operated as well as the unaffected leg increased maximal knee extension (+ 18% ± 7% p < 0.05; + 11% ± 5% p < 0.05) and flexion torque (+ 9% ± 5% p < 0.05, + 10% ± 6% p < 0.05) throughout the 6 months of rehabilitation. The H/Q ratio remained unaffected (- 2% ± 3% p = 0.93; - 4% ± 4% p = 0.27). LSI of knee extension strength increased significantly (6% ± 3% p < 0.05), while flexion strength remained unaffected (+ 2% ± 4% p = 0.27). Positive correlations underline the interrelationship between the strength pre- and post-surgery for the knee extension (r = 0.788 p < 0.05) and knee flexion strength (r = 0.637 p < 0.05) after ACLR.

CONCLUSIONS

Preoperative leg extension and flexion strength normalized to body mass are strongly correlated to postoperative strength performance after ACLR. Therefore, pre-operative quadriceps and hamstring muscle strength deficits may have a significant negative impact on functional performance following ACLR. This emphasizes the need for intensive preoperative screening and subsequent treatment to achieve the best possible preoperative leg strength before ACLR.

TRIAL REGISTRATION

DRKS00020210 .

Damage of cell envelope of Lactobacillus helveticus during vacuum drying

AIMS

The aim of this study was to gain insight into the inactivation mechanisms of Lactobacillus helveticus during vacuum drying.

METHODS AND RESULTS

Early stationary phase cells of L. helveticus were dried in a vacuum drier. Viability, cell integrity and metabolic activity of cells were assessed over time by plate counts on de Man Rogosa and Sharpe broth agar medium and cytological methods employing fluorescent reagents and nucleic acid stains. The cell envelope damage was visualized by atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FT-IR) was used to indirectly observe changes in cell components during drying. Viability, metabolic activity and cell integrity decreased during vacuum drying, and different inactivation curves, characterized by the loss of ability to resume growth, and cell injuries were found. AFM images showed cracks on the surface of dried cells. Main changes in FT-IR spectra were attributed to the damage in cell envelope.

CONCLUSION

The cell envelope was the main site of damage in L. helveticus during vacuum drying.

SIGNIFICANCE AND IMPACT OF THE STUDY

Inactivation mechanisms of L. helveticus during vacuum drying were partly elucidated. This information is useful for the improvement of the viability of vacuum-dried starter cultures.

Haemodynamic crisis and reversible multiorgan failure caused by HIV post-exposure prophylaxis after needle-stick injury in a health care worker

We report the case of a 59-year-old nurse from our HIV ward who developed a severe haemodynamic crisis with concomitant acute multiorgan failure after initiation of a post-exposure prophylaxis (PEP) with zidovudine/lamivudine (CombivirTM) and lopinavir/ritonavir (KaletraTM) after a needle-stick injury with an HIV-contaminated needle. Although serious and life-threatening adverse effects of post-exposure prophylaxis have been documented in several cases, this is the first report of a severe acute cardiovascular incident following PEP initiation.

[Surgeons learn how to learn. Study of 76,499 herniorrhaphies performed between 1993 and 1997 registered by the chamber of physicians in Westfalia-Lippe]

INTRODUCTION

New techniques require "new" surgeons who are able to apply them safely. The bushfire-like employment of laparoscopic cholecystectomy confronted a community of surgeons totally inexperienced in that technique. Thus, the collective learning curve was paralleled by a temporary increase of postoperative complications. The aim of the following study was to analyze the learning curve for laparoscopic herniorrhaphy with regard to the complication rates during that period.

METHODS

A total of 76,499 questionnaires from the external quality assurance of the Westfalia-Lippe physicians board registered between 1993 and 1997 were analyzed retrospectively. The parameters (duration of the operation and hospitalization, ASA classification, rate of obese patients, intra- and postoperative complications) were analyzed and plotted as a synchronized learning curve of the whole group of surgeons.

RESULTS

As for laparoscopic cholecystectomy, a learning curve was found for laparoscopic herniorrhaphy, which could be attributed to a decreasing duration of the procedures and increasing ASA classification and rate of morbid obese patients while complication rates were kept constantly low. After 9 months of application laparoscopic hernia repair seemed to have been introduced to a new collective of surgeons while learning parameters showed inverse trends for a short period of time. The complication rate of laparoscopic hernia repair was constantly lower than in routine open inguinal hernia repair.

CONCLUSION

Since laparoscopic inguinal hernia repair is a demanding method, surgeons apparently did not forget the lessons learned from the introduction of laparoscopic cholecystectomy as they were able to avoid increasing intra- and postoperative complication rates during their learning curve. Surgeons are learning to learn.

[Does hospital structure influence the outcome of operative treatment of femoral neck fractures?]

Data on 32 007 patients suffering from a medial fracture of the femoral neck have been collected between 1993 and 1999 in a database for external quality assurance organized by the chamber of physicians in Westfalia-Lippe. A statistical analysis (ANOVA, chi-square-test) has been performed to find out whether factors like specialization, annual volume or level of the hospital (primary, secondary or tertiary hospital) influence the outcome.

RESULTS

Patients with higher preoperative risk-factors are treated more often in primary hospitals. These clinics perform conservative treatment significantly more often than tertiary hospitals (6.5 % vs. 3.8 %). Osteosyntheses are performed more often in departments specialized in traumatology (13 %) or tertiary hospitals (16.8 %). Preoperative length of stay was 0.5-0.7 days shorter in these hospitals. There is no significant difference in postoperative complications all together (23.2-25.6 %), but a significantly lower rate in postoperative complications after osteosynthesis performed by departments specialized in traumatology (11.3 % vs. 18.8 %). A volume load of more than 50 cases per year correlates with a significant decline in postoperative complications (22.5 % vs. 28.2 %). Risk adjusted mortality does not show significant differences among the different levels of hospitals.

CONCLUSIONS

There are distinct differences regarding the way of treatment and procedural quality, but not concerning the short-term outcome between hospitals of different levels.

[Femoral neck fracture in the younger patient. Contrast between guideline and management reality--results of external quality assurance in 1,747 follow-up cases]

Between January 1993 and December 1998 26.005 patients with hip fractures underwent treatment in departments of general surgery and traumatology in Westfalia-Lippe, Germany. Data of these patients were reported to the chamber of physicians where a report card system for external quality assurance has been established since 1991. 1.747 patients were between 10 and 60 years of age. Treatment according to the guideline of hip fractures of the German College of Traumatology is compared to treatment in reality.

RESULTS

Conservative treatment declined to 2% in 1998; only 43% of these comparetively young patients were labeled as emergencies. Only 45.4% of all osteosyntheses were performed on the day of hospital admission. Almost 30% of the patients undergo hip replacement as first line therapy. Timing of operation is related to the frequency of operations per department and specialisation: the more operations per year the shorter the length of stay before operation. Early treatment is more likely in departments of traumatology than in departments of general surgery. Lethality and morbidity do not increase with early treatment.

CONCLUSIONS

The reality of treatment of hip fractures does not meet the criteria of the guideline. Further efforts have to be undertaken for the benefit of relatively young patients with hip fractures.

[General practice-relevant conclusions based on 74,400 documented biliary surgery interventions]

A statewide report card system for cholecystectomy as a surgical tracer has been established in Westfalia-Lippe as part of a program of external quality assurance. 74,400 data between 1993 and 1997 were analyzed. Pathologic findings in preoperative diagnostics (sonography, elevated bilirubin) do not lead to therapeutic splitting in a sufficient number of cases. Removal of bile duct stones should happen at the latest during cholecytectomy. Preoperative gastroscopy is performed in just about 40%. Higher rates of morbidity and lethality in the aged favour an early elective operation of symptomatic stones.

[Value of current quality assurance for surgery]

In a quality assurance project in Westfalia-Lippia more than 200,000 data of surgical patients with one of the following tracer diagnoses have been analyzed: inguinal hernia, hip fracture and cholecystectomy. Results of the analysis and improvements in outcome are presented. Further developments in the field of quality assurance are being discussed.

[Risk adjustment in external quality assurance with multivariate analysis]

Surgical clinics throughout Germany are under political and economical pressure. Comparing outcomes across clinics or ranking become more and more popular although there are no generally accepted and scientifically valid methods how to compare. Using original data of the external quality assurance project of the chamber of physicians of Westfalia-Lippia it is shown in this article that comparing raw data is often misleading. Differences in risk factors (case mix) have to be taken into consideration. A model using logistic regression methods to adjust for case mix in legality and morbidity of hip fractures is proposed. A ranking list before and after adjusting for risk factors shows partly dramatic changes. One clinic for example changed from position 97 (out of one hundred) to position 26.

[Evaluation of the tracer diagnosis "femoral neck fracture". A report of 5 years external quality assurance]

A report card system for fractures of the femur neck has been established at the department of external quality assurance of the chamber of physicians of Westphalia-Lippe since 1993. Since then several indicators of good quality have significantly changed: conservative treatment decreased from 6.8% 1993 to 4.2% in 1997, lethality decreased from 6.9% to 5.4%, average length of stay before operation decreased from 2.6 to 2.1 days, the frequency of operations on weekends increased, complications in wound healing increased from 4.9 to 6.0%, cardiopulmonary complications decreased from 11.2% to 7.8%. Between 1993 to 1997 54.3% could be dismissed to their homes; the percentage of patients being sent to rehabilitation facilities after acute care rose from 8.3% in 1993 to 20.1% in 1997. Operative treatment was performed in more than 90% of all fractures in all counties of Westphalia-Lippe. However, there was a wide and significant geographical variation in the choice between osteosyntheses and hip replacement: the percentage of hip replacement differed between 57% and 82% among different counties.

[Results of surgical quality assurance in Westphalia-Lippe--recurrence data in inguinal hernia operation. A coomparison of literature and reality]

The data of 90,289 patients of the quality-control program of the Arztekammer Westfalen-Lippe have been analyzed in regard of the patients age at the time of the primary operation and in case of operation because of recurrent inguinal hernia. In both groups of patients distribution of age was identical in principle but transferred to higher age in recurrent hernia by about 3.4 years thus indicating that recurrent hernia mostly occur early after primary operation. Shouldice method showed decreasing acceptance due to increasing numbers of repair operations by laparoscopy and Lichtenstein's method. This tendency was even more pronounced in case of recurrent inguinal hernia. Obviously the surgeons' selection of methods in inguinal hernia repair is not only influenced by evidence based data since Shouldice repair is reported to be superior in each regard.

[Fractures of the femoral neck--results of an external quality assurance in 32,000 patients]

Between Jan. 1st 1993 and Dec. 31st 1999 data was collected on 31.917 patients with fractures of the femoral neck in a statewide report card system in Westphalia-Lippe. Only 6.3% of patients were younger than 60 years. Ten percent of the population of Germany live in Westphalia-Lippe so that our data can be considered representative of Germany. A significant change was seen in the following indicators of quality: increase of operative treatment 1993 93.2%--1999 96.0% (p < 0.01 Chi Quadrat Test), decrease of mortality 1993 6.9%--1999 5.7% (p < 0.01 Chi Quadrat Test), decrease of cardiopulmonary complications 1993 11.2%--1999 8.4% (p < 0.01 Chi Quadrat Test), decrease of mean length of stay 1993 33.5 days--1999 22.2 days (p < 0.01 one-way-ANOVA), decrease of pre-operative length of stay 1993 2.57 days--1999 1.86 days (p < 0.01 one-way-ANOVA), increase of operative treatment on weekends (p < 0.01 Chi Quadrat Test). 25% of the patients had post-operative complications. Intra-operative complications were rare (1.4%). Only 48.6% of internal fixations were performed on the day of admission. The most frequent operation is hemiarthroplasty and its frequency is still increasing. Total hip replacement was done 34.1% of all cases. More patients are transferred from primary hospitals to rehabilitation facilities following operative procedures: 1993 8.3%; 1999 27.2%.

[Early surgery after hip para-articular femoral fracture. Results of a prospective study of surgical timing in 161 elderly patients]

In a prospective analysis the question should be answered, wether the mortality rate of femur fractures close to the hip joint can be diminished by operating as early as possible. 161 patients elder than 65 years could be included in the study. 86% of the 161 patients were operated upon 24 hours after trauma. The infection rate amounted to 3.4% after endoprothesis and to 1.2% after osteosynthesis. The hospital mortality was 7.4%. More than 85% of the patients could be discharged into the usual domestic surroundings. The rate of systemic complications (25.3%) was similar to the rate reported by the Chamber of Physicians with 26.1%. The hospital length of stay could not be diminished by this concept. By operating as early as possible the patients' request for mobility is fulfilled without running unjustifiable risks regarding mortality and postoperative complications. The mortality rate corresponds to the literature.

[Does quantity mean quality? An analysis of 116,000 patients regarding the connection between the number of cases and the quality of results]

METHODS

Between 1993 and 1998 data of 27,000 patients with hip fractures and 89,000 patients undergoing cholecystectomy were collected by the department of external quality assurance at the chamber of physicians of Westphalia-Lippe. The data were analyzed for the relationship between volume and outcome, specified as mortality and morbidity. Logistic regression was used to adjust the results for demographic and clinical risk factors.

RESULTS

The risk-adjusted probability of death from cholecystectomy was 89% higher in the group of small volume clinics (less than 30 procedures per year) than in the group of large volume clinics (more than 120 procedures per year) (odds ratio 1.89; 95% CI 1.19-3.00). Mortality from hip fractures was 33% higher (odds ratio 1.33, 95% CI 1.09-1.63) for the group of small volume clinics (less than 15 procedures per year) than the group of large volume clinics (more than 45 procedures per year). Among the group of small volume hospitals were some with excellent results, but they are more likely to be found in the group of large volume hospitals. On the other hand there were some departments with poorer results in the group of large hospitals.

CONCLUSIONS

There is no threshold for good results. In general there is an inverse relationship between volume and outcome. High volume, though, is not a substitute for good results. It is not possible to infer good quality from high volume alone. Small-volume departments should document quality of care and results thoroughly.

[Fracture of femoral neck: analysis of the results of external quality assurance. A report on 22,556 patients]

Since 1993 a report card system for fractures of the neck of the femur has been established in the Department of External Quality Assurance of the Chamber of Physicians of Westphalia-Lippe. Several indicators of good quality have changed significantly since then: conservative treatment decreased from 6.8 % in 1993 to 4.2 % in 1997, lethality decreased from 6.9 % to 5.4 %, average length of stay decreased from 30.9 days to 24.9 days, average length of stay before operation decreased from 2.6 to 2.1 days, the frequency of operations on weekends increased, complications in wound healing increased from 4.9 to 6.0 %, and cardiopulmonary complications decreased from 11.2 % to 7.8 %. Between 1993 and 1997, 54.3 % were dismissed to go home; the percentage of patients sent to rehabilitation facilities after acute care rose from 8.3 % in 1993 to 20.1 % in 1997. The most frequent and still increasing procedure was implantation of hemiprosthesis/bipolar prosthesis (from 38.8 % in 1993 to 41.0 % in 1997) followed by total hip replacement (decreasing from 37.4 % in 1993 to 34.2 % in 1997). Operative treatment was performed in more than 90 % of all fractures in all counties of Westphalia-Lippe. However, there was a wide and significant geographical variation in the choice between osteosynthesis and hip replacement: the percentage of hip replacements differed between 57 % and 82 % among different counties. Average length of stay before the operative procedure for patients undergoing reduction and rigid internal fixation of the fracture is still too long (1.6 days in 1997).

[Cystic liver tumor resembling echinococcosis]

The hepatobiliary cytadenoma or -carcinoma is a cystic, multilocular, intrahepatic tumor in the liver affecting mainly middle-aged people. In most cases hepatobiliary cystadenomas or -carcinomas cannot be definitely differentiated by sonography and CT from other cystic lesions in the liver. Resection of the tumorous parts of the liver as early as possible is essential for the prognosis for the patients because malignant transformation of the lesions might occur.

[Hepatocellular carcinoma in Germany. Epidemiology, etiology, clinical aspects and prognosis in 100 consecutive patients of a university clinic]

Chronic hepatitis C and B are the main causes of hepatocellular carcinoma (HCC) worldwide. Little is known about the etiology of HCC in Germany which is regarded as a low-prevalence area for viral hepatitis C (HCV) and B (HBV). To assess the etiologic factors of HCC in Germany we have retrospectively analyzed the records of 100 consecutive patients with hepatocellular carcinoma in our clinic. HCC-patients with documented status on HCV/HBV-infection and daily alcohol intake (n = 55) had HCV antibodies in 53%, HBs-Ag in 20%, isolated chronic alcohol abuse in 11% and genetic hemochromatosis in 2%. In 13% of the HCC-patients no risk factor could be identified. Coinfections with HCV and HBV were not observed. Liver cirrhosis was present in 90% of the HCC-patients. In histologically confirmed HCC (n = 71) serum alpha-fetoprotein level was normal (< 8.5 ng/ml) in 20%, moderately elevated (8.5-300 ng/ml) in 48% and considerably elevated (> 300 ng/ml) in 32% of the patients. Only 31% of all patients presented with small single lesions (< or = 5 cm) without evidence for extrahepatic metastases or portal vein thrombosis. Only 30% of the HCC-patients could be treated with a curative intention (28 hepatic resections, one orthotopic liver transplantation). Patients who underwent resection had cumulative 6-month, 1-year, 2-year and 3-year survival rates of 83.8%, 65.9%, 54.3% and 24.8% respectively. Median survival time after resection was 24.8 months compared with 5.8 months in symptomatically treated patients with unresectable HCC (n = 39). Patients with hepatitis C-associated HCC were significantly older than patients with hepatitis B-associated HCC (mean values: 63.2 vs. 54.2 years). Frequency of cirrhosis, tumor stage, alpha-fetoprotein level and prognosis did not differ between groups. In conclusion hepatocellular carcinoma was predominantly associated with chronic HCV-infection. Most patients presented with normal or moderately elevated serum AFP-levels. Prognosis was poor even after hepatic resection.

Safety of a low-dosage Filgrastim (rhG-CSF) treatment in non-neutropenic surgical intensive care patients with an inflammatory process

OBJECTIVE

To evaluate the effect and safety of a low dose Filgrastim treatment in surgical intensive care patients.

DESIGN

Prospective, clinical study.

SETTING

Surgical intensive care unit (ICU) in a university hospital.

PATIENTS

Ten patients with the systemic inflammatory response syndrome (SIRS) and ten patients with sepsis were included in the study.

INTERVENTIONS

Filgrastim was given intravenously at 1.0 microgram/kg for 3 days, followed by 0.5 microgram/kg for 4 days.

MEASUREMENTS AND RESULTS

Filgrastim treatment increased leukocyte counts and plasma levels of G-CSF. Cytokine levels (IL-6 and IL-8) decreased in the first 3 days of treatment. None of the SIRS patients developed sepsis or multiple organ failure and none of the patients died. In the sepsis group four patients died. No adverse side effects were observed, especially no attenuation of lung injury.

CONCLUSIONS

Low-dosage Filgrastim treatment in ICU patients is safe. Whether the observed changes of the inflammatory response can be attributed to Filgrastim has to be clarified in further randomized trials.

Scanning electron microscopic comparison between the thrombogenic properties of heparinized and non-heparinized vena cava catheters. A long-term study

In an experimental comparative study on rabbits, the efficacy of the reduction of surface thrombus formation was investigated using heparinized central venous catheters compared with non-heparinized. Up to a central indwelling period of ten days, there was a reduction of the thrombus layer thickness on the heparinized catheters of 80% (with a trial duration of three days this was as much as 90%). The action of the stabilized surface heparin, which leads to a substantial thromboresistance, is complex in nature. 1) By intensified adsorption of plasma proteins in the early phase (proteins consist of antithrombin III, factor IX, X and XI), there is very much less thrombocyte adhesion and aggregation on the heparinized catheter surfaces. 2) The externally orientated negative net charge of the heparin shows a similar effect. 3) If there is thrombocyte adhesion despite this, further heparin effects become more prominent. Thus the release of ThF 3 and ADP, which leads to aggregation, is markedly inhibited. On the other hand, this leads to easier dissolution of already aggregated thrombocytes and on the other to a reduction of the catalytic thrombocyte surface for the plasma clotting factors. 4) This effect is supported by the increased adsorption of antithrombin III onto the control surface. 5) Finally there is also an inhibitory effect of heparin on the activated Stuart-Prower factor. Local thrombosis on the venous catheter surface can thus be effectively reduced by local therapy, without greater risks for the intensive care patient.