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J G Seiler

Publications and source records attributed to J G Seiler.

At least 37 records · Page 2Linked to original sources
PubMed1997

Assessment of radiolucent lines about the glenoid. An in vitro radiographic study.

UNLABELLED: A study was undertaken to investigate the precision of plain radiographs in the assessment of the width of radiolucent lines and to define parameters for more accurate measurement. A metal-backed glenoid component was inserted into fourteen cadaveric scapulae; the component had a radiolucent spacer at the central post to provide a gap with a known width at the component-bone interface. The specimens were mounted in a custom-designed jig, and initial radiographs were made with the glenoid in neutral version; sequential radiographs then were made, at 5-degree intervals, with the glenoid in 0 to 40 degrees of anteversion and retroversion. Four independent observers with various levels of experience measured the width of the radiolucent lines with use of digital microcalipers. Osteometric analysis demonstrated that normal glenoid version ranged from 3 degrees of anteversion to 13 degrees of retroversion; these values were similar to those reported in previous studies. Radiographic analysis showed that accurate measurement of the width of the gap was dependent on the position of the glenoid. The measured widths of the radiolucent lines were significantly smaller than the known width of the gap when retroversion was 10 degrees or more and when anteversion was 15 degrees or more (p < or = 0.05). Radiolucent lines were not consistently observed on radiographs that were made with the glenoid in more than 20 degrees of anteversion and retroversion. An analysis of interobserver error showed close agreement among the measurements made by the different observers when the glenoid was in 0 and 5 degrees of rotation, with decreased agreement when the glenoid was rotated more than 10 degrees from neutral. CLINICAL RELEVANCE: Inaccurate positioning of the patient and anatomical variation in glenoid version may explain the variability in the reported onsets, progressions, and frequencies of radiographic loosening of glenoid components. The findings of the present study also may help to explain the poor association between clinical and radiographic findings reported for patients who have pain at the site of a total shoulder prosthesis. Radiographs made within 10 degrees of neutral should allow accurate assessment of radiolucent lines about the glenoid.

Aged↗
PubMed1997

Treatment of acquired adult planovalgus deformities with subtalar fusion.

A retrospective review was conducted of isolated subtalar arthrodeses performed on 32 adults (34 fusions) between August 1990 and September 1993. Each fusion was performed using a single large cannulated lag screw through the talar neck. The American Orthopaedic Foot and Ankle Society standard clinical rating system for the ankle and hindfoot was used to assess outcome. Patients answered subjective questions based on the scale. Followup examination was done to evaluate clinically and radiographically each patient's foot and ankle according to the scale. Average patient age was 53 years (range, 27-80 years). Average followup was 30.8 months (range, 16-55 months). Twenty-four patients answered the subjective questions, and the average subjective score was 47 of a maximum 60 points (range, 9-60 points). Clinical data from 17 patients showed an average objective score of 30 of a maximum 34 points (range, 25-34 points). The average total score was 77 of a maximum 94 possible points (range, 34-94 points). Forty-two percent of the patients indicated a 100% improvement, 42% a 75% improvement, and 16% a 50% improvement. Eighty-three percent stated they definitely would have the procedure again. Results indicate that subtalar arthrodesis is an effective treatment for adult patients with pain and disability secondary to acquired planovalgus, posttraumatic, and inflammatory conditions of the hindfoot. In addition, the American Orthopaedic Foot and Ankle Society standard rating system of the ankle and hindfoot corresponds to clinical outcome.

Adult↗
PubMed1997

The Marshall R. Urist Young Investigator Award. Autogenous flexor tendon grafts. Biologic mechanisms for incorporation.

To examine the hypothesis that different types of dense regular connective tissue may have different repair mechanisms within the synovial space, intrasynovial and extrasynovial autogenous donor flexor tendon grafts were placed within the synovial sheaths of the medial and lateral forepaw digits of dogs. Histologic, ultrastructural, biochemical, and biomechanical analyses were done between 10 days and 6 weeks after tendon grafting. Intrasynovial tendon grafts remained viable when transferred to the synovial space and appeared to heal through an intrinsic process with preservation of the gliding surface and improved functional characteristics. Extrasynovial tendon grafts functioned as a scaffolding for the early ingrowth of new vessels and cells. Early cellular necrosis consistently was followed by the ingrowth of fibrovascular adhesions from the periphery. The formation of dense peripheral adhesions, obliterating the gliding surface of the tendon, led to diminished tendon excursion and proximal interphalangeal joint rotation.

Animals↗
PubMed1996

The cutaneous innervation of the palm: an anatomic study of the ulnar and median nerves.

Twenty-five fresh-frozen cadaveric hands without obvious deformity were dissected using 3.5x loupe magnification. Median and ulnar nerves were identified in the proximal forearm and dissected distally to the midpalm. Cutaneous branches of median and ulnar nerves were described relative to an incision for carpal tunnel release. The palmar cutaneous branch of the median nerve was present in all 25 specimens. In a single specimen, the palmar cutaneous branch of the median nerve was isolated as it crossed the incision, and in another two specimens, the terminal branches of the nerve were identified at the margin of the incision. In 4 hands, a classic palmar cutaneous branch of the ulnar nerve was found an average of 4.9 cm proximal to the pisiform. In 10 specimens, a nerve of Henle arose an average of 14.0 cm proximal to the pisiform and traveled with the ulnar neurovascular bundle to the wrist flexion crease. In 24 specimens, at least one-usually multiple-transverse palmar cutaneous branch was identified originating an average of 3 mm distal to the pisiform within Guyon's canal. The origin and destination of these nerves was highly variable. In 16 specimens, an incision in the axis of the ring finger would likely have encountered at least one branch of the ulnar-based cutaneous innervation to the palm. Cutaneous branches of the ulnar nerve would be expected to cross the line of dissection frequently during open carpal tunnel release. Decreased levels of discomfort in patients undergoing endoscopic and subcutaneous types of carpal tunnel release may be in part due to the preservation of the crossing cutaneous nerves with these procedures.

Cadaver↗
PubMed1996

Posttraumatic osteonecrosis in a swine model. Correlation of blood cell flux, MRI and histology.

We used a miniature swine femoral neck fracture model to demonstrate the effects of the fracture on blood flow, histologic appearance, MRI signal and the development of posttraumatic osteonecrosis. The fracture was created and internally fixed in the right hip of 11 swine, with the left hip serving as the control. Femoral head blood flow via Laser Doppler Flowmetry and MRI data was examined for the experimental hip preoperatively, postoperatively and at 1, 2, 4 and 8 weeks postfracture. At 8 weeks, the animals were killed and the femoral heads were evaluated. Femoral head blood flow decreased immediately postfracture and continued to diminish with time. MRI signal intensities in the femoral head at 4 and 8 weeks were significantly less when the fixation failed than when it was intact. Histologic grades (0-14 points) and bone densities were 7.6 and 49%, respectively, on the experimental side, compared to 1.6 and 56% on the control side. Histologic grading, bone density values and blood flow data had no relation to changes in MRI signal intensity.

Animals↗
PubMed1996

The pathophysiology of carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is the most frequently encountered peripheral compressive neuropathy. Although the clinical diagnosis and treatment of CTS have been well defined, the pathophysiologic basis still is not understood completely. This article summarizes current thought and research pertinent to the pathophysiology of CTS.

Carpal Tunnel Syndrome↗
PubMed1995

Autogenous intrasynovial and extrasynovial tendon grafts: an experimental study of pro alpha 1(I) collagen mRNA expression in dogs.

On the basis of recent evidence that the healing processes of tendon grafts are donor-tissue specific, in situ hybridization, using a 372 bp cDNA fragment complementary to a portion of pro alpha 1(I) collagen mRNA, was utilized to compare the cellular responses to transplantation exhibited by autogenous intrasynovial and extrasynovial flexor tendon grafts. Intrasynovial and extrasynovial tendons from the hindpaw were transferred to synovial sheaths in the forepaw of 12 mongrel dogs (24 tendons) and treated with immediate controlled passive motion. The tendon grafts were harvested at 2, 4, and 6 weeks, and each was divided into a proximal, central (8 mm), and distal portion. Sections from the central portion were embedded in paraffin and subjected to in situ hybridization, autoradiography, and staining; levels of procollagen mRNA then were assessed by microscopic examination. The two types of tendon grafts exhibited different levels of pro alpha 1(I) collagen mRNA expression at all three time points. Intrasynovial tendon grafts displayed no areas of increased type-I procollagen mRNA at 2, 4, and 6 weeks. The extrasynovial tendon grafts displayed increased surface levels of type-I procollagen mRNA at 2 and 4 weeks; the levels decreased to background levels by 6 weeks. The high levels of procollagen mRNA exhibited by the extrasynovial grafts suggest increased collagen synthetic activity, indicative of a cellular response to injury, whereas the preservation of low levels of expression in the intrasynovial grafts may signify a less inflammatory cellular response.

Animals↗
PubMed1995

The application of the limited contact dynamic compression plate in the upper extremity: an analysis of 114 consecutive cases.

We sought to assess the clinical effectiveness of a new plate design which offers improved biological and biomechanical features, the limited contact dynamic compression (LCDC) plate. We analysed 114 LCDC plates applied consecutively for upper extremity fractures or reconstruction in 94 patients. Three patients were lost to follow-up, leaving 111 plates in 91 patients followed to definitive fracture/osteotomy outcome. Thirty-seven plates were applied for reconstruction in 35 patients, including 11 where standard implants had failed. Fifty-six patients had 74 plates applied for acute fractures including 12 open fractures, 23 multiply injured patients, 26 patients with concomitant fractures and seven associated neurovascular injuries. All patients were followed to definitive outcome. Union was achieved at an average of 10.7 weeks in 105 platings, while three delayed unions eventually united without further intervention, an overall union rate of 108/111, or 97.3 per cent. There were no mechanical failures of the plates or screws. In this large series a union rate of 97.3 per cent with no implant failures confirms its clinical application for traumatic and reconstructive problems in this area. Improved contouring, easier screw placement, decreased interference with cortical bone blood flow and excellent union rates are definite short-term advantages. Theoretical long-term benefits of decreased stress-shielding and lower refracture rates will require longer follow up.

Adolescent↗
PubMed1995

The intrinsic and extrinsic ligaments of the wrist. A correlation of collagen typing and histologic appearance.

20 fresh frozen human wrist specimens were dissected. Gross and histological examination and biochemical evaluation were performed on the intrinsic ligaments (scapho-lunate and luno-triquetral) and extrinsic ligaments (radio-scapho-capitate and radio-lunate). All ligaments were observed to have longitudinal collagen bundles. The intrinsic ligaments had large amounts of fibrocartilage near insertions and no elastin, while the extrinsic ligaments had little fibrocartilage and sparse amounts of elastin. The intrinsic ligaments were noted to have significantly more collagen Type 3 (41%) than the extrinsic ligaments (19%). These findings suggest that structural differences between the intrinsic and extrinsic ligaments of the wrist may in part account for the biomechanical observations that the intrinsic ligaments are stronger and elongate further prior to failure than the extrinsic ligaments.

Cadaver↗
PubMed1995

The flexor digitorum longus: an anatomic and microscopic study for use as a tendon graft.

Recent experimental studies have shown that intrasynovial donor tendons have the capacity to heal with minimal alteration in the gliding surface when grafted to an intrasynovial location. In order to evaluate the flexor digitorum longus of the foot as a potential matched donor tendon for use in flexor tendon grafting, we dissected 15 feet (75 toes) and 10 hands (50 fingers) to determine the intrasynovial lengths of the flexor digitorum longus and flexor digitorum profundus and to determine a method of tendon graft harvest. Specimens were taken from the intrasynovial portion of each tendon for evaluation by light and electron microscopy. The intrasynovial tendons of the hand and foot were similar in vascularity, cellularity, gliding surface, and ultrastructure. The flexor digitorum longus tendon of the foot was a mean length of 12 cm to the area of tendon confluence in the midfoot, which will usually provide enough tendon length for grafting from the distal phalanx to the palm of the hand. Because of the difference in length of the synovial sheaths of the fingers and toes, some extrasynovial tendon will be transferred to the synovial space when a flexor digitorum longus tendon is used.

Cadaver↗
PubMed1995

The second annular pulley: a histologic examination.

The second annular pulley and underlying flexor tendons from 15 fresh frozen fingers were prepared, sectioned transversely and longitudinally and then stained with hematoxylin-eosin, Verhoeff-Van Gieson (Elastin), Masson's trichrome and for the presence of hyaluronic acid. Three discrete layers of the second annular pulley were identified (1) an outer layer, continuous with the membranous sheath, that was richly vascularized; (2) a middle layer, characterized by radially oriented collagen fibrils and significant elastin fibrils; (3) an inner gliding surface, characterized by longitudinally oriented collagen fibrils and modified fibroblasts secreting hyaluronic acid. The three layers of the pulley seem specialized and have developed based on the functional requirements of the pulley apparatus. The outer layer serves as a source of vascular supply and nutrition, the middle layer maintains structural integrity and is organized to efficiently resist flexor tendon bowstringing, and the innermost layer facilitates efficient excursion of the underlying flexor tendons both by the orientation of the collagen fibers and by the secretion of substances that are thought to minimize friction.

Cadaver↗
PubMed1995

Growth factors and canine flexor tendon healing: initial studies in uninjured and repair models.

The role of growth factors in a variety of bone and soft tissue healing processes has been studied extensively in numerous recent models, yet little is known about the specific growth factors that may be playing a role in flexor tendon healing. We used a number of established protein purification techniques and bioassays to isolate and partially characterize a heparin-binding growth factor from unoperated canine tendons. Our data provide evidence that basic fibroblast growth factor, a potent angiogenic growth factor, is present in normal canine intrasynovial flexor tendons. We then studied repaired canine flexor tendons to further elucidate the role of growth factors in the tendon healing process. Heparin-sepharose elution profiles from three repair intervals (3, 10, and 17 days) were graphed and compared to known profiles of isolated growth factors. The three repair intervals demonstrated two elution profile peaks, consistent with varying amounts of platelet-derived growth factor and epidermal growth factor. Although additional experimentation is required to identify definitively the various protein isolates, these data provide compelling evidence that a variety of growth factors are present in uninjured and healing digital flexor tendons.

3T3 Cells↗
PubMed1995

Tire explosion injuries to the upper extremity.

We describe a protocol for treating tire explosion injuries to the hands on the basis of treatment of five cases over a 3-year period at Emory University Hospital. These high-energy wounds frequently require emergent initial debridement and stabilization, followed by complex soft tissue and skeletal reconstruction to maximize function. Data from all cases are summarized to show similarities among these injuries and differences in their response to treatment. We define the stages of treatment, emphasizing prevention, complete assessment, and early intervention, especially for limb-threatening conditions with fasciotomy, revascularization, thorough debridement, and rigid fixation. We also discuss the importance of aggressive therapy, close follow-up, and treatment of late complications. Functional reconstruction was achieved in each case, suggesting that our treatment protocol can be used successfully.

Adult↗