[Intraoperative parathyroid hormone measurement is the best predictor of postoperative symptomatic hypocalcemia]. / Die intraoperative Parathormonmessung als bester Indikator einer postoperativen symptomatischen Hypokalzämie.

BACKGROUND: The goal of this study is to evaluate risk factors for transient postoperative hypocalcemia (HC) and to define cutoff values for perioperative parathyroid hormone (PTH) and calcium parameters (Ca) to reduce the morbidity of symptomatic HC. MATERIALS AND METHODS: At our tertiary referral hospital (Luzerner Kantonsspital, Switzerland), a total of 353 patients underwent total thyroidectomy between 2006 and 2013 and were analyzed retrospectively in terms of HC risk. The serum values of calcium and PTH were measured at strictly defined time intervals, and patients' symptoms and the necessity of treatments were determined from patients' charts. RESULTS: The prevalence of transient postoperative HC was 43%; however, only 10% of patients were symptomatic. Significant risk factors for serum and symptomatic HC were calcium values (pre-, intra-, 4 h and 1 d postoperative), PTH values (intraoperative, 4 h and 1 d postoperative), and PTH decline. Interestingly, preoperative PTH values, patient age, weight of the thyroid gland, diagnosis, and sex were not significant risk factors. In the ROC analysis ('receiver operating characteristics'), calcium measurement 4 h postoperatively showed the best predictive ability for detecting serum HC, whereas intraoperative PTH measurements were predictive for symptomatic HC. CONCLUSION: Calcium and PTH values as well as PTH decline are significant risk factors for postoperative HC. Preoperatively, only calcium measurement is prognostically significant. Intraoperative PTH measurement is the most reasonable and sensitive factor for early recognition of temporary postoperative HC in the clinical setting.

The characteristics of posttraumatic syringomyelia.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVES: To investigate the characteristics of posttraumatic symptomatic syringomyelia after spinal cord injury (SCI). SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland. METHODS: The patient database was screened for patients diagnosed with posttraumatic syringomyelia. Syrinx characteristics were determined on T2-weighted magnetic resonance images. Binary logistic regression analysis was used to investigate the effects of age, injury level, injury severity and syrinx location on early syrinx formation, syrinx length and syrinx extending cranial to the lesion. RESULTS: The data of 138 patients were analyzed. The majority of the patients (78.3%) suffered from motor and sensory complete SCI (American Spinal Injury Association Impairment Scale (AIS) A). Syringomyelia was diagnosed a median 15.0 years after SCI at a median age of 42 years. The cervical spine was involved in >57% of the patients, and syringomyelia extended over a median seven vertebral levels. Complete SCI (P=0.035) and age (P=0.001) were significant predictors of early syrinx formation. Syringomyelia occurred significantly earlier in older (>30 years) patients (P⩽0.002) and those with complete SCI (P=0.027) compared with younger patients (⩽30 years) and those with incomplete SCI (AIS B-D), respectively. Age, injury level, injury severity (AIS A) and syrinx location did not have any significant (P>0.9) effect on syrinx extending cranially or syrinx length. CONCLUSIONS: Posttraumatic syringomyelia mainly occurs in patients with complete SCI (AIS A) and involves the cervical spine in 6 of the 10 patients. Patients with complete SCI and those age >30 years have an increased risk of syrinx formation within 5 years after injury.

Long-bone fractures in persons with spinal cord injury.

STUDY DESIGN: Retrospective data analysis. OBJECTIVES: To document fracture characteristics, management and related complications in individuals with traumatic spinal cord injury (SCI). SETTING: Rehabilitation centre for SCI individuals. METHOD: Patients' records were reviewed. Patients with traumatic SCI and extremity fractures that had occurred after SCI were included. Patient characteristics, fractured bone, fracture localisation, severity and management (operative/conservative), and fracture-related complications were extracted. RESULTS: A total of 156 long-bone fractures in 107 SCI patients (34 women and 73 men) were identified. The majority of patients were paraplegics (77.6%) and classified as American Spinal Injury Association Impairment Scale A (86.0%). Only the lower extremities were affected, whereby the femur (60.9% of all fractures) was fractured more frequently than the lower leg (39.1%). A total of 70 patients (65.4%) had one fracture, whereas 37 patients (34.6%) had two or more fractures. Simple or extraarticular fractures were most common (75.0%). Overall, 130 (83.3%) fractures were managed operatively. Approximately half of the femur fractures (48.2%) were treated with locking compression plates. In the lower leg, fractures were mainly managed with external fixation (48.8%). Conservative fracture management was applied in 16.7% of the cases and consisted of braces or a well-padded soft cast. Fracture-associated complications were present in 13.5% of the cases but did not differ significantly between operative (13.1%) and conservative (15.4%) fracture management. CONCLUSION: SCI was associated with simple or extraarticular fractures of the distal femur and the lower leg. Fractures were mainly managed operatively with a low complication rate.

Study participation rate of patients with acute spinal cord injury early during rehabilitation.

STUDY DESIGN: Retrospective observational study. OBJECTIVES: To investigate the study participation rate of patients with acute spinal cord injury (SCI) early during rehabilitation after conveying preliminary study information. SETTING: Single SCI rehabilitation center in Switzerland. METHODS: Newly admitted acute SCI patients receive a flyer to inform them concerning the purpose of clinical research, patient rights and active studies. Upon patient request, detailed study information is given. The rate of patients asking for detailed information (study interest) and the rate of study participation was evaluated from May 2013 to October 2014. Furthermore, the number of patients not withdrawing consent to the utilization of coded health-related data was determined. RESULTS: The flyer was given to 144 of the 183 patients admitted during the observation period. A total of 96 patients (67%) were interested in receiving detailed information, and 71 patients (49%) finally participated in at least one study. The vast majority of patients (that is, 91%) did not withdraw consent for retrospective data analysis. An age over 60 years had a significantly (P⩽0.023) negative effect on study interest and participation, and the consent rate to retrospective data analysis was significantly (P<0.04) lower in patients older than 75 years. Study interest and participation were reduced more than 5 and 14-fold, respectively, in patients older than 60 years. CONCLUSIONS: The relatively low (approximately 50%) study participation rates of acute SCI patients should be considered when planning clinical trials. The recruitment of patients older than 60 years may be reduced substantially.

The effect of arm position and bed adjustment on comfort and pressure under the shoulders in people with tetraplegia: a randomized cross-over study.

STUDY DESIGN: Randomized, within-in participant cross-over study. OBJECTIVE: The purpose of this study was to determine the effect on comfort and pressure of lying with the shoulders and bed in different positions for people with tetraplegia. SETTING: Rehabilitation hospital. METHODS: Twenty people with tetraplegia were tested lying supine with the shoulders and bed in seven different positions. The positions used a combination of three arm and two bed positions. Six of the positions reflected what is commonly recommended in acute spinal cord injury units including a crucifix-type position. The seventh position was selected by participants and reflected their preferred sleeping position. There were five outcomes: general comfort, shoulder comfort, participant choice of preferred position, peak pressure under the shoulders and areal pressure under the shoulders. Pressure was measured using a pressure mapping system and comfort using a visual analogue scale (VAS). RESULTS: The participants reported significantly higher (P<0.01) general comfort and shoulder comfort in their self-selected position compared with all other positions. There was no statistical difference in peak pressure (P=0.15) or areal pressure (P=0.08) under the shoulders between the seven positions. Most participants indicated that they preferred to lie with their shoulders adducted and internally rotated and the hands either by their sides or on their stomachs. CONCLUSION: The position of the shoulders has little effect on pressure but a notable effect on comfort. Participants preferred to sleep with their arms beside their bodies, not with their arms in a crucifix position as commonly advocated.

[Comparison of antifog methods in endoscopy. What really helps]. / Vergleich von Antibeschlagmethoden in der Endoskopie. Was wirklich hilft.

BACKGROUND: The use of a flexible or rigid fiberoptic bronchoscope belongs to the standard repertoire in anesthesiology. Besides a lack of training these procedures may be considerably compromised by endoscopic lens fogging. Several antifogging approaches are commercially available but to date no controlled studies regarding the efficacy of these devices in bronchoscopes exists. The aim of the present study was to compare the efficacy of different commercially available anti-fogging techniques for rigid and flexible bronchoscopes. MATERIALS AND METHODS: The study was performed at the department of anesthesia in a university children's hospital. An artificial airway model was created to simulate in vivo conditions with respect to airflow, temperature and atmospheric moisture. A test picture was inserted into the artificial airway for assuring a standardized view through the bronchoscopes. Antifogging efficacy of two liquid antifog solutions (Ultrastop and Anti-Fog), two antifog wipes (Lina Clear and Reso Clear) and an induction endoscope preheater system (used after one and two induction preheating phases) was assessed by video taping of the bronchoscope view of the test picture. In addition the administration of continuous oxygen airflow of 2 l min⁻¹ through the suction channel of the flexible bronchoscope was tested as an alternative method to prevent lens fogging. All final pictures were rated by 10 staff anesthesiologists who were blinded to the antifog devices used. To assess the clinical relevance of the results, ratings were classified into a 5 grade rating scale (ranging from no visualization of any structure to excellent endoscopic view allowing safe endotracheal intubation). In addition, the failure rate of each anti-fog technique was calculated. RESULTS: A total of 300 endoscopic test pictures were taken and assessed. Using the flexible bronchoscope, the use of anti-fog solution (failure rate 3 %) and Lina Clear wipes (failure rate 4%) showed the best results. In the rigid bronchoscope group Ultrastop solution (failure rate 5 %) and Lina Clear wipes (failure rate 3.5 %) showed superior results. The two-time use of the endoscope preheater system was effective using flexible (failure rate 6 %) and rigid bronchoscopes (failure rate 10 %). The application of a continuous oxygen flow of 2 l/min failed to provide a clear endoscopic view (failure rate 93.5 %). CONCLUSIONS: All commercially available antifog liquids and wipes showed slightly different reduction of lens fogging. However, other factors such as frequency of usage, the type of endoscope, hygiene properties as well as cost-effectiveness might have a substantial impact on the comparison of all tested anti-fog devices. The use of an endoscope preheater system might be a conceivable alternative method to reduce lens fogging despite the higher initial cost. However, the multiple use of the preheater system cannot be recommended at present as additional handling procedures to ensure an appropriate but safe temperature of the endoscopic tip should be provided by the manufacturer. Application of a continuous oxygen flow was shown not to be effective in preventing lens fogging using a flexible fiberoptic bronchoscope.

[Bupivacaine toxicity and propofol anesthesia : animal study on intravascular bupivacaine injection]. / Bupivacaintoxizität und Propofolanästhesie : Tierstudie zur intravasalen Bupivacaininjektion.

BACKGROUND: Several reports have confirmed the efficacy of Intralipid® (containing soya bean oil, egg phospholipids, glycerin and water) in the therapy of systemic local anesthetic intoxication. Pretreatment with Intralipid® shifted the dose-response to bupivacaine-induced asystole in rats. Whether intravenous anesthesia with propofol in the widely used medium chain triglyceride lipid emulsion increases the therapeutic range of systemically administered bupivacaine or not is unknown and was investigated in this study. METHODS: A total of 30 piglets aged 2-6 weeks and weighing 4.5-6.5 kg were randomized into 2 groups and anesthetized with sevoflurane (group S) alone or with propofol 10 mg/kg body weight (BW)/h plus sevoflurane (group PS). After 60 min of steady state anesthesia arterial blood was sampled for assessment of blood gases, acid-base state and triglyceride plasma concentrations. Thereafter bupivacaine 0.125% was continuously infused by an infusion syringe pump through a central venous line at a rate of 4 mg/kg BW/min until invasively measured mean arterial pressure (MAP) was reduced by 50% of initial value. The bupivacaine infusion was stopped, blood for assessment of bupivacaine plasma concentration was drawn and the spontaneous hemodynamic course was observed. Resuscitation was not attempted. Results are presented as median and range. The Mann-Whitney U-test was used to assess differences between the two groups for triglyceride as well as for bupivacaine plasma concentrations measured at MAP 50%. A p-value≤0.05 was considered to be significant. RESULTS: Baseline conditions (arterial blood pH, plasma protein and triglyceride plasma concentrations) did not differ significantly between the two groups. After 1 h of anesthesia, triglyceride plasma concentrations were significantly increased in group PS (median 0.69 mmol/l) compared to the corresponding baseline values (median 0.14 mmol/l; p<0.001) and to the 1 h values of group S (median 0.16 mmol/l; p<0.001). The total amount of bupivacaine administered was 9 mg/kg BW in both groups (6-13 mg/kg BW in group S, 5-13 mg/kg BW in group PS). Resulting bupivacaine plasma concentrations were 180 µmol/l (83-686 µmol/l) in group S and 185 µmol/l (130-465 µmol/l) in group PS. However, the total amount of bupivacaine administered and bupivacaine plasma concentrations at MAP 50% did not reveal statistically significant differences between the two groups but a huge variability of both parameters within each group was observed. None of the 30 piglets spontaneously recovered and they died from pulseless electrical activity or from asystolic cardiac arrest. The time from MAP 50% until cardiac arrest demonstrated a large variability but did not reveal significant differences between the two groups. The time to cardiac arrest was similar in both groups. CONCLUSION: Medium/long chain triglyceride lipid emulsion (50:50) as widely used in propofol solutions did not increase therapeutic safety in cases of intravascular bupivacaine administration in this piglet model.

Closed tracheal suction and fluid aspiration past the tracheal tube. Impact of tube cuff and airway pressure.

BACKGROUND: This study investigated the effect of different tube cuff types and airway pressures on fluid leakage past the tracheal tube cuff during suction with a closed tracheal suction system (CTSS). METHODS: Unlubricated high-volume, low-pressure tracheal tube cuffs made from polyvinylchloride (PVC) and polyurethane (PU) with a size 7.5 mm internal diameter (ID) were placed in a 22 mm ID artificial trachea connected to a test lung and inflated to 25 or 50 cmH2O of cuff pressure. Positive pressure ventilation (PPV) with peak inspiratory pressures of 15, 20 or 25 cmH2O and positive end expiratory pressures (PEEP) of 5 or 10 cmH2O were used. A CTSS catheter (14 Fr) was attached to the tracheal tube and suction was performed for 5, 10, 15 or 20 s with 200 or 300 cmH2O of negative suction pressures. The volume of fluid leaking across the tube cuff at the end of the suction procedure was measured (mL), and the airway pressure was simultaneously recorded. Fluid leakage and airway pressures during different suction conditions were compared using a Kruskal Wallis test and Mann Whitney test (P<0.05). RESULTS: The airway pressure drop during suction was similar for both tube cuffs. The PU tube cuff resulted in significantly less fluid leakage (range 0.00-0.12 mL) than the PVC tube cuff (P<0.001). For the PVC tube cuff, fluid leakage at higher cuff pressures was significantly less (P<0.01).Varying PEEP and PIP did not change the fluid leakage or the drop in airway pressure. CONCLUSION: The use of PU tube cuffs and intermittent transient increases in cuff pressure during suction can effectively reduce fluid leakage past the tracheal tube during closed tracheal suctioning.

Electrocardiographic changes during continuous intravenous application of bupivacaine in neonatal pigs.

BACKGROUND: It is controversial as to whether T-wave elevation is caused by local anaesthetics, epinephrine, or their combination. It has been shown that T-elevation after intravascular injection of a small bupivacaine test dose is caused by epinephrine and not by bupivacaine. The aim of this study was to investigate ECG changes with higher doses of i.v. bupivacaine. METHODS: Thirty neonatal pigs were anaesthetized with sevoflurane and their tracheas intubated and artificially ventilated. Under steady-state conditions, bupivacaine was continuously infused (flow rate 3.2 ml kg(-1) min(-1)) by a syringe infusion pump through a central venous catheter. Group 1 received bupivacaine 0.125%, Group 2 bupivacaine 0.5%. The ECG was continuously printed and subsequently analysed for alterations in heart rate, ventricular de- and repolarization, and arrhythmias at 1.25, 2.5, and 5 mg kg(-1) bupivacaine infused. RESULTS: Sinus rhythm persisted in all pigs. Heart rate decreased progressively in both groups, but this was significantly more pronounced in Group 1. T-wave elevation occurred in 40% and 0% (Groups 1 and 2) at 1.25 mg kg(-1), in 80% and 0% at 2.5 mg kg(-1), and in 93% and 80% at 5 mg kg(-1) bupivacaine infused. There were significant differences between the two groups at 1.25 and 2.5 mg kg(-1) infused. CONCLUSIONS: Higher doses of i.v. infused bupivacaine can cause T-elevation. With slower injection technique, T-elevation can already be detected at lower bupivacaine doses administered.

Effect of tracheal tube cuff shape on fluid leakage across the cuff: an in vitro study.

BACKGROUND: This study compared the fluid leakage in the new 'tapered' shaped against the classic 'cylindrical' shaped tracheal tube cuffs when placed in different sized tracheas. METHODS: The 7.5 mm internal diameter (ID) tracheal tube cuffs-Tapered Seal Guard (TSG), Standard Seal Guard (SSG), Hi-Lo, Microcuff, Ruesch, and Portex Profile-were compared in an in vitro apparatus. Vertical artificial tracheas with 16, 20, and 22 mm ID were intubated, 5 ml clear water was applied above the unlubricated tube cuffs, and fluid leakage was measured up to 60 min. Data of tapered vs non-tapered tube cuffs (16 observations) were compared for each tracheal diameter using the Mann-Whitney test. RESULTS: Median (range) fluid leakage (ml) at 60 min was 2.14 (0.05-4.88), 1.14 (0.00-4.84), and 0.13 (0.00-1.32), respectively, for 16, 20, and 22 mm tracheas in the TSG tube studies when compared with 4.58 (0.44-4.88), 2.21 (0.00-4.81), and 0.00 (0.00-4.81) in the SSG tube and 4.54 (1.54-4.82), 0.90 (0.00-4.49), and 4.85 (4.40-4.99) in the Microcuff tube studies. Leakage in all polyvinylchloride (PVC) tube cuffs was almost complete (5 ml) within 5 min (P<0.001). CONCLUSIONS: The tapered PU tube cuff was as effective as the cylindrical PU cuffs in smaller tracheal diameters and was more efficient than the cylindrical Microcuff PU tube cuff in larger tracheal diameter in preventing subglottic fluid leakage across the tube cuff tested in this in vitro study. PVC tube cuffs leaked much more and faster than PU cuffs.

[Intrathecal opioid medication for perioperative analgesia in severely handicapped children undergoing spinal operations]. / Intrathekale Opioidmedikation zur perioperativen Analgesie bei schwer behinderten Kindern mit Wirbelsäulenoperationen.

PURPOSE OF THE STUDY: Intrathecal opioids have been shown to be safe and effective for postoperative analgesia in healthy children for spinal surgery. The aim of this study was to evaluate the applicability of intrathecal opioids in severely handicapped children scheduled for spinal surgery. METHODS: With hospital ethical committee approval, patients with physical states III and IV of the ASA classification requiring spinal surgery were retrospectively studied. In addition to inhalational anesthesia with sevoflurane or intravenous anesthesia using propofol, morphine 20 microg/kgBW and sufentanil 1.5 microg/kgBW were administered intrathecally before surgery. After surgery an infusion of nalbuphine was started. Need for additional intraoperative and postoperative analgesics, time of extubation, postoperative pain scores and p(a)CO2 values as well as adverse effects were recorded. RESULTS: A total of 28 patients aged from 2.8 to 18.5 years (median 11.6 years) were studied. Immediate tracheal extubation in the operating room was possible in 17 patients and for 11 patients delayed extubation was elected. All patients were extubated within 24 h except for 1 patient who received massive postoperative transfusions. In 26 out of 28 patients (93%) the combination of intrathecal opioids with postoperative nalbuphine provided adequate analgesia. Observed side effects were post-operative nausea and vomiting (PONV), pruritus and moderate hypoventilation. In two patients a change to intravenous morphine therapy was necessary. CONCLUSION: The use of intrathecal opioids for perioperative pain control from spinal fusion in severely handicapped children is feasible. Intrathecal opioids provide adequate postoperative analgesia and allow early extubation without persisting relevant respiratory compromise in most of these patients.

Cuffed endotracheal tubes in children reduce sevoflurane and medical gas consumption and related costs.

BACKGROUND: This study aims to evaluate sevoflurane and anaesthetic gas consumption using uncuffed vs. cuffed endotracheal tubes (ETT) in paediatric surgical patients. METHODS: Uncuffed or cuffed ETT were used in paediatric patients (newborn to 5 years) undergoing elective surgery in a randomized order. Duration of assessment, lowest possible fresh gas flow (minimal allowed FGF: 0.5 l/min) and sevoflurane concentrations used were recorded. Consumption and costs for sevoflurane and medical gases were calculated. RESULTS: Seventy children (35 uncuffed ETT/35 cuffed ETT), aged 1.73 (0.01-4.80) years, were enrolled. No significant differences in patient characteristics, study period and sevoflurane concentrations used were found between the two groups. Lowest possible FGF was significantly lower in the cuffed ETT group [1.0 (0.5-1.0) l/min] than in the uncuffed ETT group [2.0 (0.5-4.3) l/min], P<0.001. Sevoflurane consumption per patient was 16.1 (6.4-82.8) ml in the uncuffed ETT group and 6.2 (1.1-14.9) ml in the cuffed ETT group, P=0.003. Medical gas consumption was 129 (53-552) l in the uncuffed ETT group vs. 46 (9-149) l in the cuffed ETT group, P<0.001. The total costs for sevoflurane and medical gases were 13.4 (6.0-67.3)euro/patient in the uncuffed ETT group and 5.2 (1.0-12.5)euro/patient in the cuffed ETT group, P<0.001. CONCLUSIONS: The use of cuffed ETT in children significantly reduced the costs of sevoflurane and medical gas consumption during anaesthesia. Increased costs for cuffed compared with uncuffed ETT were completely compensated by a reduction in sevoflurane and medical gas consumption.

Electrocardiographic alterations during intravascular application of three different test doses of bupivacaine and epinephrine: experimental study in neonatal pigs.

BACKGROUND: Origin of electrocardiographic (ECG) alterations during intravascular injection of local anaesthetic solutions is controversial. The aim of this study was to elucidate whether epinephrine, bupivacaine or their combination is responsible for ECG alteration. METHODS: Forty-five piglets were randomized into three groups. After induction of general anaesthesia using sevoflurane and peripheral venous cannulation, the trachea was intubated, the lungs were artificially ventilated, and anaesthesia was maintained by sevoflurane. Under steady state 0.2 ml kg(-1) and after 10 min 0.4 ml kg(-1) of one of the following three test solutions was administered i.v.: bupivacaine 0.125% (Group 1), bupivacaine 0.125%+epinephrine 1:200 000 (Group 2), and plain epinephrine 1:200,000 (Group 3). The ECG was analysed for alterations in heart rate and T-elevation. RESULTS: After injection of 0.2 or 0.4 ml kg(-1) test solution, an increase in heart rate of at least 10% was found in none of Group 1 and in all of Groups 2 and 3. After application of 0.2 ml kg(-1) test solution, T-elevation was found in 7% of Group 1 and in 93% of Groups 2 and 3. The injection of 0.4 ml kg(-1) revealed a T-elevation in 27%, 100%, and 100%, respectively, in Groups 1, 2, and 3. CONCLUSIONS: This animal model demonstrated that increases in heart rate and T-elevation in the ECG during i.v. application of a common test dose (0.2 ml kg(-1)) of bupivacaine are caused by epinephrine addition. Whether higher doses of bupivacaine alone can cause similar ECG changes or not requires further studies.

Assessment of anthropometric, systemic, and lifestyle factors influencing bone status in the legs of spinal cord injured individuals.

The aim of the present study was to assess the influence of muscle spasms, systemic or lifestyle factors on bone mass and geometry of the femur and the tibia in people with long-standing spinal cord injury (SCI). Fifty-four motor complete SCI people with paralysis duration of between 5 and 50 years were included in the study. Spasticity was measured by means of the Ashworth scale. Distal epiphyses and mid shafts of the femur, tibia, and radius were measured by peripheral quantitative computed tomography. From the epiphyseal scans, trabecular and total bone mineral density (BMDtrab and BMDtot) were calculated, and from the shaft scans, cortical BMD (BMDcort), total and cortical cross-sectional area (CSAtot and CSAcort), and muscle cross-sectional areas (CSAmus) were determined. Personal characteristics, anthropometric, as well as life-style factors, were assessed by means of a questionnaire. A Spearman correlation matrix was produced with measured data. Correlation coefficients exceeding 0.3 were tested for significance by performing linear regression for parametric data and ANOVA for non-parametric data. Subjects with higher spasticity scores had significantly larger CSAmus in the upper and lower leg. Both spasticity and CSAmus were found to be significantly related to BMDtrab and BMDtot of the distal epiphysis of the femur and to CSAcort of the femoral shaft. In the lower leg, bone parameters of the tibia were found to be strongly related to corresponding bone parameters of the radius, which suggests a systemic origin. No significant relationships were found between bone parameters and any of the life-style factors. The extent of bone loss caused by disuse of the lower extremities in people with long-standing SCI is influenced by systemic factors. Additionally, spasticity has a positive effect on bone parameters of the femur.

Relationship between the duration of paralysis and bone structure: a pQCT study of spinal cord injured individuals.

The aim of the present study was to describe bone loss of the separate compartments of trabecular and cortical bone, as well as changes in bone geometry of a large number of spinal cord injured (SCI) individuals. Eighty-nine motor complete spinal cord injured men (24 tetraplegics and 65 paraplegics) with a duration of paralysis of between 2 months and 50 years were included in the study. Distal epiphyses and midshafts of the femur, tibia, and radius were measured by peripheral quantitative computed tomography. The same measurements were performed in a reference group of 21 healthy able-bodied men of the same age range. In the femur and tibia, bone mass, total and trabecular bone mineral density (BMDtot and BMDtrab, respectively) of the epiphyses, as well as bone mass and cortical cross-sectional area of the diaphyses, showed an exponential decrease with time after injury in the spinal cord injured subjects. The decreasing bone parameters reached new steady states after 3-8 years, depending on the parameter. Bone mass loss in the epiphyses was approximately 50% in the femur and 60% in the tibia, while the shafts lost only approximately 35% in the femur and 25% in the tibia. In the epiphyses, bone mass was lost by reducing BMD, while in the shaft bone mass was lost by reducing cortical wall thickness, a process achieved by endosteal resorption advancing at a rate of about 0.25 mm/year within the first 5-7 years after injury. Except for a slight transient decrease in cortical BMD of the femoral and tibial shaft during the first 5 years after the spinal cord lesion, cortical BMD of the spinal cord injured subjects was found to be at reference values. Bone parameters of the radial epiphysis in paraplegic subjects showed no deficits compared to the reference group. Furthermore, a trend for an increased radial shaft diameter suggests periosteal apposition as a consequence of increased loading of the arms.