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Biomedical subjects

G Herzberg

Publications and source records attributed to G Herzberg.

At least 19 recordsLinked to original sources
PubMed2005

Three-dimensional in vivo displacements of the shoulder complex from biplanar radiography.

The goal of this study was to adapt roentgen photogrammetry to in vivo studies of shoulder skeletal motion during arm elevation in the scapular plane. Numerous in vitro and in vivo studies have been published describing shoulder bone movements. They involve plain radiographic measurements and utilize a three-dimensional (3D) approach. Measurements are either direct using pins implanted in bones, or indirect recording points on medical images. Roentgen photogrammetry locates points in space from two projections obtained from two different radiographic incidences. The technique has been applied in vivo by implanting metallic balls in bones. However, to be used as a standard clinical procedure, the technique must be adapted to be less invasive. In vivo photogrammetric reconstruction of known points in 3D space requires that the subject is strictly motionless between the successive radiographic exposures or that the exposures are obtained simultaneously. Methods used in this study were developed to allow subsequent exposures to be used for analysis. Numerical tools have been developed to align the two projections of a point in 3D space which have moved slightly between two successive exposures. The standard photogrammetric technique is completed by geometric modeling of the shoulder complex and humerus, and by the control of their mutual proximity at the level of joints. Bones are modeled as a set of simple volumes linked together using geometric shapes described by shape parameters. The coincidence between real bone contours and radiographic projections of the modeled bone gives the values of the shape parameters and the accurate location in space. Results focus on two different topics: errors related to the use of roentgen photogrammetry with successive exposures, and results obtained by applying roentgen photogrammetry to the in vivo shoulder complex. Results describing shoulder bone and joint displacements are presented for comparison with previously published results. The technique of roentgen photogrammetry can successfully be applied to patients. The radiographic protocol is simple, and data can be obtained easily and quickly from the digitized films. The data obtained from asymptomatic shoulders compared favorably with published values. Future research will focus on comparisons between kinematics of the symptomatic and asymptomatic contralateral limbs in volunteers.

Clavicle↗
PubMed2004

[Primary Swanson metacarpophalangeal joint arthroplasty in major hand traumas. A report of two cases at 14 years follow-up].

In major hand injuries, destroyed joints may be treated by joint transfer, arthroplasty or fusion with or without temporary external fixation. Four immediate digital metacarpophalangeal joint Swanson implants in two patients with amputation or devascularizated near-amputation were reviewed with a 14 years follow-up. No infection was noted. Prostheses were stable with a 31 degrees active range of motion and grip strength was 42% of the opposite side. Functional results were "useful" with patients satisfaction. In one patient, heavy manual worker, implants were replaced fourteen years after trauma because of recent pain on one joint and implants fragmentation. The other patient was painless. Immediate Swanson arthroplasty in major hand injuries may be an alternative in metacarpophalangeal joints destruction.

Adult↗
PubMed2003

Coronal fractures of the proximal scaphoid: the proximal ring sign.

We present two coronal fractures of the proximal scaphoid which were both missed in the acute stage as interpretation of initial radiographs was difficult. In both cases, recognition of the so-called "Proximal Ring Sign" on the PA ulnar deviation radiographs may have helped diagnosis. CT scans were necessary to fully demonstrate the fractures. Open reduction and internal fixation, performed 2 and 4 months after the injury, resulted in union in both cases.

Adult↗
PubMed2002

Acute dorsal trans-scaphoid perilunate fracture-dislocations: medium-term results.

The purpose of this study was to investigate the medium-term results (mean follow-up, 8 years) of a series of 14 trans-scaphoid dorsal perilunate fracture-dislocations treated operatively at an average of 6 days following injury. Eleven underwent open reduction and internal fixation through a dorsal approach. Combined palmar and dorsal approaches were used in only three cases, for open reduction and internal fixation in two and proximal row carpectomy in one. The Mayo wrist score revealed five excellent, three good, five fair and one poor result. The average score was 79% (range 55-95%). All internally fixed scaphoids healed and no lunate or scaphoid fragment avascular necrosis with collapse was observed. Carpal alignment was satisfactory in most cases. Post-traumatic radiological midcarpal and/or radiocarpal arthritis were almost always observed at follow-up, but this did not correlate with the Mayo wrist score.

Adolescent↗
PubMed2001

Anatomical basis of latissimus dorsi and teres major transfers in rotator cuff tear surgery with particular reference to the neurovascular pedicles.

Musculotendinous transfers (MTT) of latissimus dorsi (LD) and teres major (TM), either in isolation or combination, have recently been advocated to treat irreparable rotator cuff tears. The purpose of this study was to (1) review the anatomy of the LD and TM neurovascular pedicles, and (2) undertake experimental MTT to humeral insertions of either supraspinatus or infraspinatus to evaluate tension on their nutrient arteries in six positions of the arm. Twenty-six shoulders were studied, 22 of which had previously been injected with red latex. Gross dissection, using 4.3 x magnification when necessary, was followed by one MTT for each shoulder (11 LD, 6 TM, 9 combined). The anatomy of the LD and TM neurovascular pedicles was consistent with classic descriptions in 85% of cases; "medialisation" of the thoracodorsal artery was observed in 4 specimens. Tension on the teres major artery was not observed in 15 isolated or combined MTTs, while tension on the thoracodorsal artery in at least one arm position was observed in 60% of 20 isolated or combined MTTs. Three factors were found to be associated with tension: medialisation of the thoracodorsal artery, fixation onto the supraspinatus insertion, and 90 degrees abduction combined with internal rotation. The results suggest that tension on the thoracodorsal artery is possible under certain circumstances when an isolated LD or combined MTT is performed to treat irreparable rotator cuff tear.

Adult↗
PubMed1999

Human hand allograft: report on first 6 months.

BACKGROUND: Long-term survival of animal limb allografts with new immunosuppressant combinations and encouraging results of autologous limb replantations led us to believe that clinical application of hand transplantation in human beings was viable. METHODS: On Sept 23, 1998, we transplanted the right distal forearm and hand of a brain-dead man aged 41 years on to a man aged 48 years who had had traumatic amputation of the distal third of his right forearm. The donor's arm was irrigated with UW organ preservation solution at 4 degrees C, amputated 5 cm above the elbow, and transported in a cool container. We dissected the donor limb and the recipient's arm simultaneously to identify anatomical structures. Appropriate lengths of viable structures were matched. Transplantation involved bone fixation, arterial and venous anastomoses (ischaemic time 12.5 h), nerve sutures, joining of muscles and tendons, and skin closure. Immunosuppression included antithymocyte globulins, tacrolimus, mycophenolic acid, and prednisone. Maintenance therapy included tacrolimus, mycophenolic acid, and prednisone. Follow-up included routine post-transplant laboratory tests, skin biopsies, intensive physiotherapy, and psychological support. FINDINGS: The initial postoperative course was uneventful. No surgical complications were seen. Immunosuppression was well tolerated. Mild clinical and histological signs of cutaneous rejection were seen at weeks 8-9 after surgery. These signs disappeared after prednisone dose was increased (from 20 mg/day to 40 mg/day) and topical application of immunosuppressive creams (tacrolimus, clobetasol). Intensive physiotherapy led to satisfactory progress of motor function. Sensory progress (Tinel's sign) was excellent and reached the wrist crease (20 cm) on day 100 for the median and ulnar nerves, and at least 24 cm to the palm by 6 months when deep pressure, but not light touch sensation, could be felt at the mid palm. INTERPRETATION: Hand allotransplantation is technically feasible. Currently available immunosuppression seems to prevent acute rejection. If no further episode of rejection occurs, the functional prognosis of this graft should be similar to if not better than that reported in large series of autoreconstruction.

Adenosine↗
PubMed1999

A new radiographic method for evaluation of the position of the carpus in the coronal plane: results in normal subjects.

The methods used to quantify pathological variations of the position of the carpus in the coronal plane, mainly ulnar translation of the carpus from trauma or rheumatoid disease, are often difficult to use in arthritic or postsurgical wrists; moreover, they require the measurement of the whole length of the third metacarpal. The aim of this study was to determine a reliable and easy-to-use index to analyse the position of the carpus in the coronal plane. One hundred PA X-rays of normal wrists were studied, of which 56 presented with a medial hamate facet of the lunate. An index of position of the carpus in the coronal plane is defined as the ratio of orthogonal distances from [1] the most medial point of the distal radius and [2] the most medial point of the capitate to the long axis of the radius: its mean value being 1.06 (+/- 0.13) in this series of normal wrists. The index is influenced by the presence of a medial hamate facet of the lunate, but is not dependent on the ulnar head and radial styloid process, nor on the length of the third metacarpal. To help to define the usefulness of the index in quantifying the different types of ulnar carpal translations in clinical practice, further studies are required.

Adult↗
PubMed1999

[The first transplantation of a hand in humans. Early results].

The first hand allograft was performed on September 23, 1998. The right distal forearm and hand of a brain dead donor was transplanted to a 48 year old recipient who had undergone a traumatic amputation of the distal third of his right forearm. The donor's arm was irrigated with organ preservation solution (UW) and transported to Lyon in a cool container. Two teams simultaneously dissected the donor's limb and the recipient's stump to identify anatomical structures. Transplantation involved bone fixation, arterial and venous anastomoses, nerve sutures, joining of the muscles and tendons, and skin closure. Immunosuppression consisted of anti-lymphocyte, polyclonal and monoclonal antibodies, tacrolimus, mycophenolic acid, and prednisone. Mild clinical and histological signs of rejection occurred at week 9 after surgery. They disappeared with adjustments of the immunosuppressant doses. Seven months after surgery the patient was in good general condition. Intensive physiotherapy led to satisfactory progress of motor function. Sensory progress is excellent, reaching the fingertips. A longer follow-up is necessary to appreciate the final result. In the absence of further rejection, the functional prognosis of the graft should be similar to that reported after successful autoreconstruction.

Adenosine↗
PubMed1999

[What is "ethical weighing" in animal testing?]

Ethical justification of legally required testing procedures with respect to pain, suffering or harm inflicted on animals are frequently being trivialised to meaningless phrases with a predictable outcome. Most applicants will not realise what kind of burdens they are placing upon ethics as an instrument for justification. Also, in ethical theory "defensibility" of animal testing is much less rigorously contemplated as it is, or would be, in comparable human testing. For these reasons, the article presented is critically investigating judicial and legal interpretations of the term "ethical weighing". In cases where true progress for the cause of animals becomes evident it chooses a rather unusual route based on the ground work of other scientists. The centre of attention is not given to more or less fictions cost/benefit calculations or point-systems but rather to the moral self- examination or possible self-justification of the scientist, meaning: a true reflection on ethics.

Journal Article↗
PubMed1999

[Anatomical study of the interosseous membrane of the forearm].

The authors have dissected 20 forearms of human cadavers to study anatomy and some functions of the IOM. The fibers bundles of the IOM were arranged in one plane descending obliquely and distally from the radius to insertion to the ulna. Central band of the IOM was easily found and was thick. It's a resistant ligament for longitudinal stability of the radius. Now, it's important to know anatomical alignment of the IOM because ultrasound imaging can be used for diagnosis of its rupture or elbow injuries and in a early future, surgical methods of repair or reconstruction of IOM will be developed.

Forearm↗
PubMed1998

[Resistance of the the coraco-clavicular ligaments to traction: clinical application].

One method for treating chronic incapacitating acromioclavicular dislocation is to resect the external extremity of the clavicle and to stabilise the stump by ligamentoplastic procedures, using the coracoclavicular ligament. The purpose of this work was to evaluate the mechanical quality of the ligamentoplastic approach. Twelve fresh cadavers, average age 80 years, were studied. The samples taken were 24 coracoclavicular ligaments, 24 coraco-acromial ligaments, 9 tendons from the palmaris longus muscle and 9 iliotibial tracts. The ligaments removed were tested in a Instron traction machine at a speed of 10 cm/mn. The mechanical properties of the coracoclavicular and coraco-acromial ligaments were studied. For comparison, those of the tendon of the palmaris longus muscle and the iliotibial tract were also studied. The results show the pre-rupture resistance of the coraco-acromial ligament to be 50% lower than that of the trapezoid and conoid parts of the coracoclavicular ligaments taken together. These results suggest the validity of ligamentoplastic treatment using the coraco-acromial ligament, but that reinforcement, using a tendon from the palmaris longus muscle or a piece of the iliotibial tract, may also be necessary, especially for subjects taking part in sports or with well-developed musculature.

Acromioclavicular Joint↗
PubMed1996

Thiamine, riboflavin, folate, and vitamin B12 status of infants with low birth Weights receiving enteral nutrition.

The purpose of the present study was to monitor the vitamin status of 14 low-birth-weight (LBW) infants (< 1,750 g birth weight) at 2 weeks and an additional four infants at 3 weeks who were receiving an enteral formula providing 247 micrograms/100 kcal thiamine, 617 micrograms/100 kcal riboflavin, 37 micrograms/100 kcal folate, and 0.55 micrograms/100 kcal vitamin B12. The mean birth weight of the 18 infants was 1,100 +/- 259 g, and mean gestational age was 29 +/- 2 weeks. Weekly blood, 24-h urine collections, and dietary intake data were obtained. For thiamine, red blood cell (RBC) transketolase activity was within the normal range for all infants. For riboflavin, RBC glutathione reductase activity was normal for all infants except one. We calculated from intake and urinary excretion data that these infants require 225 micrograms/100 kcal thiamine and 370 micrograms/100 kcal riboflavin, respectively. Mean plasma folate levels were 21 +/- 11 ng/ml at 2 weeks and 18 +/- 5 ng/ml at 3 weeks. RBC folate levels were 455 +/- 280 ng/ml at 2 weeks and 391 +/- 168 ng/ml at 3 weeks. All folate blood values were normal, except for one subject with an elevated level (59 ng/ml). Vitamin B12 plasma values were 737 +/- 394 pg/ml at 2 weeks and 768 +/- 350 pg/ml at 3 weeks, and all values were normal except for three infants with elevated values. In conclusion, appropriate vitamin status was maintained during this short observational period, during administration of this enteral formula; however, riboflavin concentrations in the enteral feed may be excessive.

Birth Weight↗
PubMed1993

Perilunate dislocations and fracture-dislocations: a multicenter study.

A series of 166 perilunate dislocations and fracture-dislocations from 7 centers was retrospectively studied. The diagnosis was missed initially in 41 cases (25%). A classification system was presented. The perilunate fracture-dislocations were more frequent than the perilunate dislocations at a ratio of two to one. The displacement was dorsal in 161 cases (97%) and palmar in only 5 (3%). The dorsal transscaphoid perilunate fracture-dislocations represented 96% of the dorsal perilunate fracture-dislocations and 61% of the whole series. The clinical and radiologic outcome of 115 perilunate dislocations and fracture-dislocations with at least 1 year and an average of 6 years 3 months of follow-up was studied. Open injury and delay of treatment had an adverse effect on clinical results, whereas anatomical type had less influence. In cases treated early, the clinical results were satisfactory but the incidence of post-traumatic arthritis was high (56%). In the dorsal perilunate dislocation group of pure ligamentous injuries and in the dorsal transscaphoid group, the best radiologic results were observed after open reduction and internal fixation. In the latter group, the fixation of the scaphoid alone was not always sufficient and left occasionally scapholunate dissociation, lunotriquetral dissociation, ulnar translation of the carpus, or other carpal collapse patterns. The initial appraisal of both the osseous and ligamentous pathology was very important.

Adult↗
PubMed1993

Intraoperative histopathologic nerve examination in brachial plexus injury.

A new method of indirect intraoperative evaluation of axonal quality in a proximal nerve stump by immediate observation of the myelin sheath is presented. Using this method in 18 cases of brachial plexus injuries, the proximal stumps of particular roots or trunks were classified as unfavorable, favorable, or fair. This histologic grading was compared to the clinical result obtained after surgical repair of these nerves in the corresponding territory. In three cases, the proximal stump of the brachial plexus root was sacrificed because of an unfavorable grade, and a nerve transfer was performed: the results were useful in two cases and "academic" in one case. Among 12 cases with favorable histologic grades, nine were associated with useful function and three were "academic". Among three cases with a fair histologic grade, two were associated with an "academic" result and one was useful in a nine-year-old child. Retrospective comparison with classic examination after axon staining showed that intraoperative histopathologic grading was somewhat too optimistic in six cases and was relevant in 12 cases. This method may be helpful in choosing proper methods for brachial plexus repair. A normal or almost normal histopathologic condition in the proximal stump of the nerve is mandatory for obtaining a useful clinical result after repair.

Adolescent↗
PubMed1993

Career self-efficacy in occupational therapy practice.

Career expectations contribute to job satisfaction, which ultimately affects personnel retention. This paper focuses on a current trend in career literature: career self-efficacy, judgments about the efficacy of one's career choice and adjustment. Career self-efficacy is relevant to occupational therapy in that therapists are leaving the profession because of unmet career expectations. This paper explores Bandura's self-efficacy theory (the basis of career self-efficacy) and discusses the authors' experience in clinical practice and education relating the application of career self-efficacy to occupational therapy. Suggested methods for enhancing career self-efficacy include the implementation of a professional development course based on Bandura's self-efficacy theory; incorporation of self-efficacy content into the professional theory and practice courses; clinical supervision that creates realistic self-perceptions of performance during the field-work experience; and transitional programs for entry-level practitioners that identify and explore personal career expectations and support for the experienced practitioner.

Humans↗