Status quo of operative training in emergency surgery in Germany - results of a survey.

BACKGROUND: Emergencies and emergency surgeries are a central part of everyday surgical care in Germany. However, it is unclear how emergency surgery is practically trained in clinics on a daily basis and what training concept is underlying. Therefore, the aim of this survey study was to capture the status quo of emergency surgical training of German general and visceral surgeons. METHODS: The members of the German Society for General and Visceral Surgery were surveyed online (n = 5281). The questionnaire included demographic data and expertise in surgery and assistance in emergency surgery regarding common emergency surgical operations. In addition, further training measures in emergency surgery and their support by employers were queried. RESULTS: Only complete questionnaires (n = 184, response rate 3.5%) were included in the analysis. Most participants were in training (n = 69; 38%), followed by senior physicians (n = 52; 29%), specialists (n = 31; 17%) and chief physicians (n = 30; 17%). 64% of the participants were employed at university hospitals or maximum care hospitals. Regarding further training opportunities, in-clinic shock room training was most frequently used. Outside of their own clinic, the ATLS course was most frequently mentioned. Operations for cholecystitis and appendicitis as well as emergency stoma procedures are the most common emergency procedures. There was a strong difference in the frequency of operated cases depending on the level of training. For operations to treat acute abdominal traumas (hemostasis of liver and spleen, packing) as well as outside of visceral surgery, only low competence was reported. Over 90% of survey participants consider emergency surgery to be an indispensable core competence. Neither in the old (76%) nor in the new training regulations (47%) is emergency surgery adequately represented according to the participants' assessment. There was a significantly lower prevalence of the "sub-steps concept" in emergency surgery at 38% compared to elective surgery (44%). Important elements of imparting skills in emergency surgery are simulation and courses as well as operative sub-steps, according to the majority of survey participants. CONCLUSION: The results show that general and visceral surgeons in Germany are introduced to emergency surgery too little structured during further training and at specialist level. The survey participants had, as expected, hardly any experience in emergency surgery outside of visceral surgery but surprisingly also little experience in visceral surgical trauma care. There is a need to discuss the future organization of emergency surgical training. Adequate simulation structures and extracurricular courses could contribute to an improvement in this respect.

Rating of camera navigation skills in colorectal surgery.

PURPOSE: In advanced minimally invasive surgery the laparoscopic camera navigation (LCN) quality can influence the flow of the operation. This study aimed to investigate the applicability of a scoring system for LCN (SALAS score) in colorectal surgery and whether an adequate scoring can be achieved using a specified sequence of the operation. METHODS: The score was assessed by four blinded raters using synchronized video and voice recordings of 20 randomly selected laparoscopic colorectal surgeries (group A: assessment of the entire operation; group B: assessment of the 2nd and 3rd quartile). Experience in LCN was defined as at least 100 assistances in complex laparoscopic procedures. RESULTS: The surgical teams consisted of three residents, three fellows, and two attendings forming 15 different teams. The ratio between experienced and inexperienced camera assistants was balanced (n = 11 vs. n = 9). Regarding the total SALAS score, the four raters discriminated between experienced and inexperienced camera assistants, regardless of their group assignment (group A, p < 0.05; group B, p < 0.05). The score's interrater variability and reliability were proven with an intraclass correlation coefficient of 0.88. No statistically relevant correlation was achieved between operation time and SALAS score. CONCLUSION: This study presents the first intraoperative, objective, and structured assessment of LCN in colorectal surgery. We could demonstrate that the SALAS score is a reliable tool for the assessment of LCN even when only the middle part (50%) of the procedure is analyzed. Construct validity was proven by discriminating between experienced and inexperienced camera assistants.

[Diagnostic ability of power measurement of different grip forms for distal median nerve lesion]. / Stellenwert der Kraftmessung verschiedener Greifformen zur Diagnostik der peripheren Medianusläsion.

BACKGROUND: Peripheral lesions of the median nerve cause characteristic changes of the grip function of the hand. For evaluating grip force changes, measurement by dynamometers (JAMAR dynamometer and pinch dynamometer) is of high relevance. In this study the ability of grip force measurements of different grip forms was evaluated to discriminate between a simulated median nerve lesion and healthy subjects. MATERIAL AND METHODS: In 21 healthy subjects, the grip force of power grip was measured by the JAMAR dynamometer at the second stage including measurement of force at the fingertips and the thenar by a sensor glove. With a pinch dynamometer the power of palmar abduction, precision grip, pincer grip and pinch grip was determined. Measurements were performed with and without median nerve block at the wrist. RESULTS: In power grip of the JAMAR dynamometer at the second stage a significant reduction of the grip force of 13.4% was found (p < 0.03). The power distribution between the fingers D2-D5 did not change with median nerve block. The most relevant reduction of grip force in median nerve block compared with the healthy control was measured in palmar abduction (72.1%, p < 0.0002), followed by precision grip 31.0% (p < 0.0001), pincer grip 23.6% (p < 0.0004) and pinch grip 18.8% (p < 0.0002). CONCLUSIONS: For the discrimination between healthy subjects and subjects with a median nerve block there was a limited relevance of the measurement of the power grip and force distribution at the fingers by the JAMAR dynamometer. However, the best distinction was observed by dynamometric measurement of other grips than power grip, such as palmar abduction, precision grip, pincer grip and pinch grip. The results could be relevant for the clinical diagnostics and rehabilitation of median nerve lesion, complementing the widespread measurement of the power grip by other grip forms.

Electrophysiology-based quality assurance of nerve-sparing in laparoscopic rectal cancer surgery: Is it worth the effort?

BACKGROUND: After low anterior resection for rectal cancer, visual assessment of pelvic autonomic nerve preservation can be difficult due to the complexity of neuroanatomy, as well as surgery- and patient-related factors. The present study aimed to evaluate nerve-sparing quality assurance using the laparoscopic neuromapping (LNM) technique. METHODS: We prospectively investigated a series of 30 patients undergoing laparoscopic low anterior resection. Nerve-sparing was evaluated both visually and electrophysiologically. LNM was performed using stimulation of pelvic autonomic nerves under simultaneous cystomanometry and processed electromyography of the internal anal sphincter. Urogenital and anorectal functions were evaluated using validated and standardized questionnaires preoperatively, at short-term follow-up, and at mid-term follow-up at a median of 9 months (range 6-12 months) after surgery. RESULTS: One patient reported new onset of urinary dysfunction, and another patient reported new onset of anorectal dysfunction. Of the 20 sexually active patients, five reported sexual dysfunction. Visual assessment by laparoscopy confirmed complete nerve preservation in 28 of 30 cases. For prediction of urinary and anorectal function, LNM sensitivity, specificity, positive and negative predictive value, and overall accuracy were each 100 %. LNM with combined assessment for prediction of sexual function yielded a sensitivity of 80 %, specificity of 93 %, positive predictive value of 80 %, negative predictive value of 93 %, and overall accuracy of 90 %. CONCLUSIONS: LNM is an appropriate method for reliable quality assurance of laparoscopic nerve-sparing.

Midterm functional results of taTME with neuromapping for low rectal cancer.

BACKGROUND: Information on functional outcomes after laparoscopic-assisted transanal total mesorectal excision (taTME) is limited. This study analyzed the functional results in patients with low rectal cancer. METHODS: Ten consecutive patients (nine males) undergoing electrophysiologically controlled nerve-sparing taTME were investigated prospectively and asked to complete functional questionnaires [the International Prostate Symptom Score (IPSS), International Index of Erectile Function, Female Sexual Function Index, Wexner score, and low anterior resection syndrome (LARS) score]. Bladder function was also assessed according to residual urine volume. Preoperative function was compared to the functional outcome 3 and 6 months, and 9 months if eligible, after stoma closure or surgery in the absence of a diverting stoma. RESULTS: Prior to therapy, urinary and sexual function was impaired in 40 and 60% of patients, respectively. None of the patients developed pathological residual urine volumes after at least unilateral functional pelvic nerve-sparing. Median IPSS was lower than preoperative scores (p > 0.05). Two males with incomplete nerve preservation were considered impotent during a median follow-up of 15 months (range 6-20 months). The female was judged to be sexually inactive. The median Wexner score was 1 (range 0-7) prior to any therapy and increased to 7 (range 0-15) at 6 months (p = 0.029), with 40% of patients categorized as having no LARS and 50% minor LARS. The median LARS score was 28 (range 9-38) at 3 months and 26 (range 9-32) at 6 months (p = 0.165). CONCLUSIONS: Despite a small sample size and confounding factors, data indicate that taTME has the potential to preserve continence, sufficient bowel function, and urogenital function.

Education Team Time Out in Oncologic Visceral Surgery Optimizes Surgical Resident Training and Team Communication-Results of a Prospective Trial.

BACKGROUND: Surgical education is highly dependent on intraoperative communication. Trainers must know the trainee's training level to ensure high-quality surgical training. A systematic preoperative dialogue (Educational Team Time Out, ETO) was established to discuss the steps of each surgical procedure. METHODS: Over 6 months, ETO was performed within a time limit of 3 minutes. Digital surveys on the utility of ETO and its impact on performance were conducted immediately after surgery and at the end of the study period among the staff of the participating disciplines (trainer, trainee, surgical nursing staff, anaesthesiologists, and medical students). The number of surgical substeps performed was recorded and compared with the equivalent period one year earlier. RESULTS: ETO was performed in 64 of the 103 eligible operations (62%). Liver resection (n = 37) was the most frequent procedure, followed by left-sided colorectal surgery (n = 12), partial pancreaticoduodenectomy (n = 6), right-sided hemicolectomies (n = 5), and thyroidectomies (n = 4). Anaesthesiologists most frequently reported that ETO had a direct impact on their work during surgery (90.9%). The influence scores were 46.8% for trainees, 8.8% for trainers, 53.3% for surgical nursing staff and 66.6% for medical students. During the implementation of ETO, a trend towards more assisted substeps in oncologic visceral surgery was seen compared to the corresponding period one year earlier (51% vs.40%; p = 0.11). CONCLUSION: ETO leads to improved intraoperative communication and more performed substeps during complex procedures, which increases motivation and practical training. This concept can easily be implemented in all surgical specialties to improve surgical education.

[Testing of practical surgical teaching at a distance-Experiences with a hybrid OSCE in surgery]. / Prüfung praktisch-chirurgischer Lehre auf Distanz ­ Erfahrungen mit einem Hybrid-OSCE in der Chirurgie.

BACKGROUND: The COVID-19 pandemic has changed medical teaching worldwide. Digital teaching and examinations are successful for cognitive learning objectives, whereas practical skills had to be carried out predominantly in person under strict hygiene standards. AIM: This study presents the opportunities and challenges of using a presence objective structured clinical examination (OSCE) at a distance with digital support. METHOD: Following surgical practical teaching an OSCE was conducted in presence, where students demonstrated practical skills in one room while the examiners were connected via videoconference from another room. Students were surveyed about the OSCE and sustained learning via a standardized online questionnaire after completion of the surgical teaching. Additionally, examiners were surveyed on their experiences. RESULTS: In the online survey 40 students participated (25% of n = 157 students contacted) and 36 completed questionnaires were analyzed. Overall, the implementation of an OSCE even under pandemic conditions was perceived as very positive by the students (92% of students n = 33). In particular, the acquisition of practical skills was rated as very high. For 78% (n = 28) of the students, the acquisition of competencies through the practical examination was particularly sustainable. The vast majority of students and examiners felt safe regarding infection control because of the hygiene concept (92%, n = 33). Overall, 80 students achieved grade 1 (51%), 71 students grade 2 (45.2%) and 6 students grade 3 (3.8%) (grade 1 = very good, grade 6 = very bad). CONCLUSION: Practical examinations are essential for checking practical learning objectives and can be implemented at a distance with a well-developed hygiene concept and digital support.

Change in the temporal coordination of the finger joints with ulnar nerve block during different power grips analyzed with a sensor glove.

Ulnar nerve injuries can cause deficient hand movement patterns. Their assessment is important for diagnosis and rehabilitation in hand surgery cases. The purpose of this study was to quantify the changes in temporal coordination of the finger joints during different power grips with an ulnar nerve block by means of a sensor glove. In 21 healthy subjects, the onset and end of the active flexion of the 14 finger joints when gripping objects of different diameters was recorded by a sensor glove. The measurement was repeated after an ulnar nerve block was applied in a standardized setting. The change in the temporal coordination of the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints with and without the nerve block was calculated within the same subject. In healthy subjects, the MCP joints started their movement prior to the PIP joints in the middle and ring finger, whereas this occurred in the reverse order at the index and little finger. The DIP joint onset was significantly delayed (P<0.01). With the ulnar nerve block, this coordination shifted towards simultaneous onset of all joints, independent of the grip diameter. The thumb and index finger were affected the least. With an ulnar nerve block, the PIP joints completed their movement prior to the MCP joints when gripping small objects (G1 and G2), whereas the order was reversed with larger objects (G3 and G4). The alterations with ulnar nerve block affected mainly the little finger when gripping small objects. With larger diameter objects, all fingers had a significant delay at the end of the PIP joint movement relative to the MCP and DIP joints, and the PIP and DIP joint sequence was reversed (P<0.01). Based on the significant changes in temporal coordination of finger flexion during different power grips, there are biomechanical effects of loss of function of the intrinsic muscles caused by an ulnar nerve block on the fine motor skills of the hand. This can be important for the diagnosis and rehabilitation of ulnar nerve lesions of the hand.

[DIGITOS-prosthesis for the proximal interphalangeal joint--long-term results]. / DIGITOS-Fingermittelgelenkprothese--Langzeitergebnisse.

Most important methods for the surgical treatment of painful arthritis of the proximal interphalangeal joint are the joint fusion or the implantation of a prosthesis. There are a lot of different models for joint replacement. Sixteen patients received 19 middle joint replacements performed with the DIGITOS-prosthesis between 1996 and 1999. Over a period of seven years, 14 patients with 17 prostheses have been observed prospectively. In the 7-year follow-up, a minimal radiolucent line at the bone-cement junction and huge periarticular osteophytes could be found in every case. No cortical penetration, luxation, or implant fractures were recorded. The preoperative median range of motion was 50 degrees. Postoperatively, there was an improvement to 60 degrees. The range of motion decreased to 50 degrees after one year and to as little as 30 degrees after seven years. Preoperatively, eleven patients had pain with activity and three had pain without activity. During the whole follow-up period there were only two patients who had pain at work. All patients were satisfied with the results of the operation throughout the control period and would choose the same treatment again.

Reliability of the grip strength coefficient of variation for detecting sincerity in normal and blocked median nerve in healthy adults.

In the assessment of hand and upper limb function, detecting sincerity of effort (SOE) for grip strength is of major importance to identifying feigned loss of strength. Measuring maximal grip strength with a dynamometer is very common, often combined with calculating the coefficient of variation (CV), a measure of the variation over the three grip strength trials. Little data is available about the relevance of these measurements in patients with median nerve impairment due to the heterogeneity of patient groups. This study examined the reliability of grip strength tests as well as the CV to detect SOE in healthy subjects. The power distribution of the individual fingers and the thenar was taken into account. To assess reliability, the measurements were performed in subjects with a median nerve block to simulate a nerve injury. The ability of 21 healthy volunteers to exert maximal grip force and to deliberately exert half-maximal force to simulate reduced SOE in a power grip was examined using the Jamar® dynamometer. The experiment was performed in a combined setting with and without median nerve block of the same subject. The force at the fingertips of digits 2-5 and at the thenar eminence was measured with a sensor glove with integrated pressure receptors. For each measurement, three trials were recorded subsequently and the mean and CV were calculated. When exerting submaximal force, the subjects reached 50-62% of maximal force, regardless of the median nerve block. The sensor glove revealed a significant reduction of force when exerting submaximal force (P1 sensor) with (P<0.032) and without median nerve block (P<0.017). An increase in CV at submaximal force was found, although it was not significant. SOE can be detected with the CV at the little finger at using a 10% cut-off (sensitivity 0.84 and 0.92 without and with median nerve block, respectively). These findings suggest low reliability of the power grip measurement with the Jamar® dynamometer, as well as that of the CV for detecting SOE. However, the combination of finger forces including the thenar area and the CV at the little finger could lead to better reliability for detecting feigned reduction of grip strength. The methods were as reliable in subjects with a median nerve block as in healthy subjects.

[Linked Prosthesis for the Proximal Interphalangeal Joint: 17-Year Long-Term Results]. / Gekoppelte Fingermittelgelenksprothese - Verlauf über 17 Jahre.

BACKGROUND/PURPOSE: Joint replacement is a widely used procedure to treat painful osteoarthritis of the proximal interphalangeal joint. From 1996 to 1999, 16 patients received 19 hinged, piston-based DIGITOS prostheses in our department. In 2007, the 7-year clinical course of 14 patients (17 devices) was published in this journal. Now 12 of these patients (15 devices) have been followed with an average history of 17 years, and the preoperative data has been compared with the results after 7 and 17 years, respectively. PATIENTS AND METHODS: The patients were 10 women and 2 men, whose average age at the time of the preoperative examination was 63 (48-69) years. Replacements were performed on the index (6), middle (6), and ring finger (3). There were 14 idiopathic osteoarthritic changes and 1 posttraumatic osteoarthritic change. Follow-up included a clinical (range of motion in the proximal interphalangeal joint, extension lag, pain) and radiological examination. In addition, the DASH score was obtained and the patients were asked whether or not they would undergo the same surgery again. The results after 7 and 17 years were reviewed for statistically significant differences. RESULTS: While there were significant changes regarding extension lag and flexion in the first 7 years after replacement of the proximal interphalangeal joint, only minor changes were observed between 7 and 17 years after surgery. While the prosthesis was in its correct position in the first 2 years after implantation, all prostheses exhibited radiolucent lines after 4 years and periprosthetic osteophytes after 5 years. 17 years after surgery, the radiolucent lines had not increased at all and the osteophytes had increased insignificantly compared with the 7-year findings. None of the patients reported pain; all of them said that they would undergo the same surgical procedure again. CONCLUSION: While there were significant clinical and radiological changes in the first 7 years after replacement of the proximal interphalangeal joint by a linked DIGITOS prosthesis, only minor changes were observed between 7 and 17 years after surgery.

[Simulated Total Wrist Fusion and its Influence on Hand Grip Function]. / Einfluss der simulierten Handgelenksarthrodese auf die Greiffunktion der Hand.

BACKGROUND: Wrist fusion is still a common treatment for patients with advanced stage arthritis. Since patients are often intimidated by the functional limitations, we intended to evaluate the influence of the lack of wrist motion in different positions on the dynamic grip function and the grip strength of the hand. METHODS: We simulated wrist fusion in 20° extension and 20° flexion and evaluated the following grip types: fist closure, 2 different power grips, pinch grip and precision grip. A TUB sensor glove was used, which allowed us to dynamically record the range of motion (ROM) of the finger joints as well as grip strength. Nineteen healthy subjects participated and all types of grips were performed using a standardised protocol with and without simulated wrist fusion. RESULTS: Lack of wrist motion in 20° extension had no relevant effect on the fingers' ROM, grip speed or strength. Simulated fusion in 20° flexion also had no influence on ROM or grip speed, rejecting our hypothesis that a tenodesis effect of the extensors in flexion would decrease ROM in the finger joints and grip speed. However, we were able to show a significant decrease of grip strength in flexion compared with extension or healthy wrists. The decrease averaged between 23 and 42% of healthy values, depending on the grip type. There was no change in strength distribution among the fingers. CONCLUSION: We didn't find any impact of lack of wrist motion on finger movement during forceful hand grip at normal speed. However, a significant loss of grip strength in flexed position of the wrist joint should be considered in patients with an indication for bilateral wrist fusion.

[Predictive value of the HISS-scoring system for estimation of trauma severity and the time off work after hand injuries]. / Einschätzung der Verletzungsschwere sowie der Dauer der Arbeitsunfähigkeit bei Handverletzungen mit dem HISS-Bewertungsschema.

BACKGROUND: The estimation of the time off work depending on the injury pattern and severity is of major interest in the treatment of hand injuries. The predictive value of the HISS score (Hand Injury Severity Scoring System) was evaluated. MATERIAL AND METHODS: According to this score, 184 work-related injuries (1999 to 2002) were analyzed prospectively, excluding injuries of both hands. The median age was 37.9 years (18 to 65 years), 11 % of the patients were female. RESULTS: A significant correlation was established between the HISS score and the time off work (p < 0.0001, r = 0.51). The score also correlated with the degree of work incapacity (p < 0.0001). CONCLUSION: Our data confirm the predictive value of the HISS score for the early estimation of the time off work resulting from hand injuries. However, the estimation is limited to injuries distal to the wrist.

Correlation of bone mineral density with strength and microstructural parameters of cortical bone in vitro.

The aim of this study was to evaluate the influence of microstructural parameters, such as porosity and osteon dimensions, on strength. Therefore, the predictive value of bone mineral density (BMD) measured by quantitative computed tomography (QCT) for intracortical porosity and other microstructural parameters, as well as for strength of cortical bone biopsies, was investigated. Femoral cortical bone specimens from the middiaphysis of 23 patients were harvested during total hip replacement while drilling a hole (dia. 4.5 mm) for the relief of the intramedullary pressure. In vitro structural parameters assessed in histological sections as well as BMD determined by quantitative computed tomography were correlated with yield stress, and elastic modulus assessed by a compression test of the same specimens. Significant correlations were found between BMD and all mechanical parameters (elastic modulus: r = 0.69, p < 0.005; yield stress: r = 0.64, p < 0.005). Significant correlations between most structural parameters assessed by histology and yield stress were discovered. Structural parameters related to pore dimensions revealed higher correlation coefficients with yield stress (r = -0.69 for average pore diameter and r = -0.62 for fraction of porous structures, p < 0.005) than parameters related to osteons (r = 0.60 for osteon density and average osteonal area, p < 0.005), whereas elastic modulus was predicted equally well by both types of parameters. Significant correlations were found between BMD and parameters related to porous structures (r = 0.85 for porosity, 0.80 for average pore area, and r = 0.79 for average pore diameter in polynomial regression, p < 0.005). Histologically assessed porosity correlated significantly with parameters describing porous structures and haversian canal dimensions. Our results indicate a relevance of osteon density and fraction of osteonal structures for the mechanical parameters of cortical bone. We consider the measurement of BMD by quantitative computed tomography to be helpful for the estimation of bone strength as well as for the prediction of intracortical porosity and parameters related to porous structures of cortical bone.

Predictive value of bone mineral density and morphology determined by peripheral quantitative computed tomography for cancellous bone strength of the proximal femur.

Peripheral quantitative computed tomography (pQCT) is an established diagnostic method for assessment of bone mineral density in the diagnosis of osteoporosis. However, the capacity of structural parameters of cancellous bone measured by high-resolution computed tomography remains to be explored. In 33 patients, bone mineral density (BMD) of the proximal femur was measured in vitro by pQCT using cylindrical biopsies from the intertrochanteric region harvested before the implantation of an artificial hip joint. By digital image analysis of CT scans, parameters derived from histomorphometry describing the microarchitecture of cancellous bone were measured. The biopsies were also loaded to failure by an uniaxial compression test to determine the biomechanical parameters, Young's modulus, strength, and maximum energy absorption (E(max)). Strong correlations were found for BMD vs. mechanical parameters (r = 0.73 for Young's modulus, r = 0.82 for strength, and r = 0.79 for E(max); p < 0.001, n = 29). The morphological parameters, bone volume per trabecular volume (BV/TV), apparent trabecular thickness (app.Tb.Th), apparent trabecular separation (app.Tb.Sp), and trabecular number (Tb.N), correlated significantly with all mechanical parameters. The combination of morphological parameters with BMD in a multivariate regression model led to an overall, but only moderate, increase in R(2) in all cases. Our data confirm the high predictive value of BMD for the mechanical competence of cancellous bone of the intertrochanteric region. However, quantification of cancellous bone structure by image analysis of CT scans may provide additional qualitative information for the analysis of bone strength.

Prediction of cortical bone porosityIn Vitro by microcomputed tomography.

The high importance of intracortical porosity for mechanical strength of cortical bone has been established. The contribution of other parameters of microstructure such as osteon dimensions for strength is in discussion. The aim of this study was to evaluate the predictive value of microcomputed tomography (µCT) for porosity and other microstructural parameters of cortical bone in cortical bone biopsies. Femoral cortical bone specimens from the middiaphysis of 24 patients were harvested during the procedure of total hip replacement at the location where normally one hole (Ø 4.5 mm) for the relief of the intramedullary pressure is placed.In vitro intracortical porosity and bone mineral density (BMD) measurements by µCT were compared with structural parameters assessed in histological sections of the same specimens. A strong correlation was found between intracortical porosity measured by µCT and histological porosity (r=0.95,P<0.0001). Porosity measured by µCT was also a strong predictor for other parameters describing dimensions of porous structures. BMD-1 was associated with osteonal area (r=-0.76,P<0.0001). We consider the measurement of porosity by µCT as a very potent procedure for assessing intracortical porosity and parameters related to porous structures of cortical bone nondestructivelyin vitro.

Photophysical properties of the ground and triplet state of four multiphenylated [70]fullerene compounds.

The particular chromophoric structure of C(70)Ph(10), which consists of two cage-centered π-electron systems, makes its photophysical properties an exception to those found for other phenylated [70]fullerenes C(70)Ph(2n) (n=2-4). For these other C(70)Ph(2n) species, their intrinsic photophysical properties undergo smooth transitions as a function of n.

Functional treatment of physeal and periphyseal injuries of the metacarpal and proximal phalangeal bones.

BACKGROUND/PURPOSE: Hand fractures are common injuries in infants. Complications are rare because of potent remodeling dimension and rapid healing of growing bone. There is limited remodeling capacity for angular and rotational deformity so displaced fractures often require open reduction and internal fixation. METHODS: The authors present a splint system for a protected reduction and mobilization program of displaced proximal phalanx and metacarpal fractures. The custom-molded 2-component thermoplastic splint allows motion of the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. It has been developed to allow bone healing and recovery of motion at the same time. In this study, the authors evaluated the clinical and radiologic results of a series of 11 consecutive infants with displaced metacarpal fractures and 13 displaced proximal phalanx fractures who received functional treatment. RESULTS: Fracture consolidation and full active motion was achieved simultaneously in 4 weeks in 21 children; 2 infants required physiotherapy, and 1 child was lost to follow-up. No further growth abnormality was seen within a 12-month observation period. CONCLUSION: When there is no damage of soft tissue the functional mobilization program can lead to good results treating displaced physeal and periphyseal hand injuries of proximal phalanx and metacarpal fractures. J Pediatr Surg 36:611-615.

Predictive value of bone mineral density and Singh index for the in vitro mechanical properties of cancellous bone in the femoral head.

OBJECTIVE: The purpose of this study was to assess the validity of two methodically different radiological parameters, bone mineral density and Singh Index, for the prediction of mechanical properties in femoral cancellous bone. DESIGN: Coherence between in vitro evaluation of mechanical properties and bone mineral density on a femoral bone slice, combined with clinical determination of Singh Index on ordinary X-rays. BACKGROUND: It is accepted that bone densitometry yields excellent prediction of mechanical bone quality, but is considered to be an expensive and not widely available method for routine diagnostics in clinical practice. In contrast, determination of Singh Index is an inexpensive and simple technique, but its predictive value for bone mechanics is still controversially discussed. METHODS: We used cortically confined bone slices from 33 femoral heads. Bone mineral density was measured using quantitative computed tomography. Strength and elastic modulus were assessed by mechanical testing in up to 39 circular positions on each slice. Singh Index was evaluated on ordinary X-rays of the hip by two independent readers. RESULTS: Bone mineral density showed strong correlations with strength (r=0.86) and good correlations with elastic modulus (r=0.68). Singh Index correlated well with strength (r=0.70), but only moderately with elastic modulus (r=0.52). CONCLUSIONS: The strong validity of bone mineral density in predicting mechanical bone quality was confirmed. Singh Index assessment permits a rough estimation of mechanical strength in particular and can therefore be used for first estimations of mechanical bone quality, provided that readings were performed by experienced clinicians. RELEVANCE: Reduced mechanical bone quality induces an increase in fracture risk. Whenever performed, bone mineral density measurement allows an excellent evaluation of the mechanical properties of cancellous bone in the hip and can be recommended for screening evaluations. The assessment of Singh Index on ordinary X-rays of the hip is an inexpensive and simple method, and allows a rough estimation of the mechanical quality of the femur. However, due to its subjective character, its predictive value for the mechanical quality of bone in individual patients remains uncertain.

Prediction of strength of cortical bone in vitro by microcomputed tomography.

OBJECTIVE: The aim of this study was to evaluate the predictive value of bone mineral density and intracortical porosity measured by microcomputed tomography for the strength of cortical bone biopsies. DESIGN: Experimental study comparing the predictive value of bone mineral density and of intracortical porosity determined in vitro by microcomputed tomography for the mechanical properties of cortical bone cylinders. BACKGROUND: The assessment of cortical bone strength might be relevant for the prediction of fracture risk or the choice of suitable therapy strategies in orthopaedic surgery. The predictive value of cortical density for the mechanical properties is discussed controversially. The relevance of intracortical porosity measured by histomorphometry has been established, but the predictive value of porosity determined by microcomputed tomography remains to be explored. METHODS: Femoral cortical bone specimens from the mid diaphysis of 24 patients were harvested during total hip replacement procedure at the location, where a diaphyseal hole (diameter 4.5 mm) was drilled in order to reduce the intramedullary pressure. In vitro intracortical porosity and bone mineral density measurements by microcomputed tomography were compared with strength and elastic modulus assessed by a compression test transverse to the Haversian systems of the same specimens. RESULTS: Significant negative correlations were found between porosity measured by microcomputed tomography scans and yield stress, stiffness and elastic modulus (P<0.001), however, the positive correlations between bone mineral density and mechanical parameters were stronger (P<0.0001). The mechanical parameter best predicted by mineral density as well as by porosity was yield stress (r=0.72,P<0.0001;r=-0.64,P<0.001). CONCLUSIONS: Bone mineral density determined by microcomputed tomography imaging in vitro may be a potent method to predict mechanical properties of cortical bone non-destructively. The application in vivo remains to be explored.