Biomedical subjects

J G Seiler

Publications and source records attributed to J G Seiler.

At least 19 recordsLinked to original sources

PubMed2001

Vascular anatomy of the brachioradialis rotational musculocutaneous flap.

The purpose of this 2-part vascular injection study was to (1) determine the sources of blood supply to the brachioradialis muscle and the distance around which the brachioradialis muscle flap may be rotated for local soft tissue reconstruction and (2) determine the fasciocutaneous vascular perfusion territory associated with the vascular pedicle of the brachioradialis muscle flap. Lead oxide injections were administered in 16 fresh frozen human upper extremity amputation specimens to determine the contribution of the isolated radial recurrent artery (RRA) and subsequent 3- and 6-cm segments of radial artery (RA) to a rotational brachioradialis muscle flap. The RRA perfused an average of 41% (range, 20% to 60%) of the brachioradialis muscle length. Selective injection of the RRA and the proximal 3-cm segment of the RA perfused 80% (range, 59% to 100%) of the muscle length, corresponding to more than 90% of muscle volume. Flap rotation consistently provided adequate tissue coverage to the antecubital fossa, the lateral elbow, and the proximal one-third volar forearm. Based on these findings, the fasciocutaneous perfusion territory of the isolated vascular pedicle was quantified by selective India ink injection studies in 10 fresh frozen cadaveric specimens. Consistent fasciocutaneous perfusion occurred directly over the muscle belly. No specimen, however, was perfused greater than approximately 1 cm distal to the musculocutaneous junction. This 2-part study defines the vascular anatomy and local utility of the brachioradialis rotational musculocutaneous flap.

Aged↗

PubMed2000

Flexor tendon grafting to the hand: an assessment of the intrasynovial donor tendon-A preliminary single-cohort study.

We report the results of a pilot study using intrasynovial donor tendons for flexor tendon reconstruction in 8 patients (10 digits) at a mean follow-up time of 3.8 years for neglected or failed primary repair of zone 2 lacerations and for neglected flexor digitorum profundus avulsions. The flexor digitorum longus to the second toe was used as the donor tendon graft. Four patients (4 digits) underwent single-stage reconstruction and 4 patients (6 digits) had multistage reconstruction. The overall patient satisfaction using a standardized visual analog reporting scale was excellent. There was 1 excellent, 1 good, 1 fair, and 1 poor result in the single-stage reconstruction group, including 1 repair site rupture and 1 digit requiring tenolysis. In the multistage reconstruction group there was 1 excellent, 3 good, 1 fair, and no poor results, including 1 digit requiring tenolysis. One patient was lost to follow-up. There was no donor site morbidity. The average active motion recovery was 64% and 56% for single-stage and multistage reconstructions, respectively, and was 73% overall for single digit reconstructions. The results of this pilot study suggest that intrasynovial tendon grafting may offer an improved alternative for tendon grafting to the synovial spaces of the digit.

Adolescent↗

PubMed2000

Influenza A induced rhabdomyolysis resulting in extensive compartment syndrome.

This is a case of influenza A induced rhabdomyolysis resulting in extensive compartment syndrome and acute renal failure in a 10-year-old child. The patient required fasciotomies in all four extremities. Even after fasciotomies were performed, the muscle tissue continued to swell, suggesting a primary myositis. This case emphasizes the importance of considering the diagnosis of compartment syndrome in patients with influenza infection and severe myalgia.

Acute Kidney Injury↗

PubMed2000

Digital flexor sheath: repair and reconstruction of the annular pulleys and membranous sheath.

Rupture or transection of the digital pulley may necessitate repair or reconstruction to treat symptomatic flexor tendon bowstringing. When reconstruction is necessary, intrasynovial tendon grafts may provide superior gliding characteristics when compared with traditional extrasynovial tendon grafts. Lacerations of the membranous portion of the digital sheath and of noncritical annular pulleys usually do not require operative repair.

Biomechanical Phenomena↗

PubMed2000

Iliac crest autogenous bone grafting: donor site complications.

Autogenous bone grafting is often done in orthopaedic surgery for a variety of conditions. The iliac crest is currently the most common donor site for obtaining autogenous bone graft. We searched the literature to summarize reported complications related to the donation of autogenous bone from the iliac crest. Our review revealed reports of arterial injury, ureteral injury, herniation, chronic pain, nerve injury, infection, fracture, pelvic instability, cosmetic defects, hematoma, and tumor transplantation. Currently, autogenous bone grafting is a necessary part of the treatment of various orthopaedic conditions. Obtaining bone from the iliac crest can be associated with significant morbidity. As bone grafting technology emerges, the known complications of the current standard should be weighed against the risk of alternate therapies.

Bone Transplantation↗

PubMed2000

Compartment syndromes of the upper extremity.

Upper extremity compartment syndromes are difficult conditions that are manifest in a myriad of ways. Careful attention to the details of the history and physical examination can assist in the development of a useful working diagnosis. Testing ITPs is the best method available to help confirm the diagnosis. Prompt fasciotomy is effective for diminishing compartment pressure and limiting additional tissue necrosis due to pressure elevation. Unfortunately, a number of characteristics specific to compartment syndrome affect ultimate outcome. Other variables, such as the amount of muscle damage from the initial injury, problems originating from any associated fracture, and soft tissue injury, also significantly affect overall patient outcome.

Compartment Syndromes↗

PubMed1999

Forearm compartment pressures: an in vitro analysis of open and endoscopic assisted fasciotomy.

Pressure reduction for standard open fasciotomy and a novel endoscopic fascial release were compared in experimental conditions of elevated forearm compartment pressures by continuously monitoring intracompartmental pressures in 22 cadaver forearms. Both methods were effective in diminishing tissue pressures. Intracompartmental pressures were reduced to significantly lower levels following open versus endoscopic assisted fasciotomy (2.9 mm Hg vs. 13.2 mm Hg). In the endoscopic group a statistically significant second decrease in pressure was observed after dermatomy, reducing intracompartmental tissue pressures from 13.2 mm Hg to 3.1 mm Hg. The results of this study suggest that endoscopic assisted fasciotomy can reduce elevated tissue pressures, confirming previous findings that fascial release is of primary importance in decreasing intracompartmental tissue pressures. Open fasciotomy, however, gave significantly greater decompression than the endoscopic technique, a difference that may be even more substantial in the clinical setting due to several limiting factors of this in vitro model. Our results also suggest that immediate skin closure following fasciotomy increased tissue pressure and therefore should be avoided.

Aged↗

PubMed1999

Publication rates of abstracts presented at the 1993 annual Academy meeting.

What percent of abstracts presented at the American Academy of Orthopaedic Surgeons annual meeting are submitted, survive peer review, and eventually are published? The answer to this fundamental question is important because many national meeting attendees use the unscrutinized information that is presented to alter their surgical practices. At the 1993 American Academy of Orthopaedic Surgeons meeting, 573 abstracts were presented. After a 5-year period, 44% of abstracts presented were published as papers in a peer reviewed journal. The results suggest that for various reasons, the majority of presented material at the Academy meeting has not been authenticated scientifically to be as accurate as papers that survive the rigors of peer review.

Abstracting and Indexing↗

PubMed1999

Flexor tendon suture methods: a quantitative analysis of suture material within the repair site.

This study compared the cross-sectional area and volume occupied by suture material at the repair site in three common methods of flexor tendon repair. A total of 51 human cadaveric tendons were studied. Zone II flexor digitorum profundus tendon lacerations were created and then repaired using the techniques described by Kessler, Tajima, and Savage. Quantitative cross-sectional area and volumetric measurements of suture material within each repair site were determined using a digital image analysis system. The Tajima repair occupied 27% of the tendon area at the repair site, while the Savage and Kessler repairs occupied 18% and 2%, respectively.

Cadaver↗

PubMed1999

Wrist arthrodesis using a wrist fusion plate.

All wrist arthrodeses done between 1990 and 1996 using a Synthes wrist fusion plate were reviewed. Independent assessment done by a certified hand therapist included a patient survey, standardized Jebsen-Taylor hand function test and activities of daily living test, and a Buck-Gramcko and Lohmann evaluation. We evaluated 13 wrists in 11 patients. Overall satisfaction was 100% of patients (mean follow-up, 31.5 months; range, 13 to 61 months). Mean preoperative and postoperative pain scores improved from 7.2 to 0.8, respectively, and functional scores improved from 5.0 to a postoperative mean value of 7.4. Jebsen-Taylor scores were virtually identical for fused and uninvolved wrists. There were no pseudarthroses, no plate failures, no tendon ruptures, and no significant postoperative infections; there was a single plate removal because of tenuous skin coverage. Short-term results using a comprehensive assessment of a custom plate designed for wrist arthrodesis show promising clinical outcomes.

Activities of Daily Living↗

PubMed1999

Changes in rat paw perfusion after experimental mononeuropathy: assessment by laser Doppler fluxmetry.

UNLABELLED: This study was performed to determine the changes in perfusion that occur after chronic constriction injury (CCI). Male Sprague-Dawley rats weighing 275-300 g had loosely constricting ligatures placed around the left sciatic nerve. Paw withdrawal latency (PWL) to heat, skin temperature, and skin perfusion (laser Doppler) of the hind paws were measured before and for 30 days after CCI. PWL decreased significantly on the side of the CCI (maximum of 34% decrease on Postoperative Day [POD] 3), then returned to normal over a 20-day period. Skin temperature initially increased on the side of CCI, then decreased with respect to the control limb on PODs 20-30. Despite the initial increase in skin temperature on the side of CCI, skin perfusion significantly decreased immediately after CCI (maximum of 51% decrease on POD 6). The perfusion gradually returned to normal over 20 days. Because return to normal perfusion occurred while the skin temperature became colder than the control side, we conclude that there is no relationship between paw surface temperature and perfusion. IMPLICATIONS: Our data suggest that loss of sympathetic tone in thermoregulatory arteriovenous anastomoses leads to decreased nutritional blood flow to the skin of the affected limb after chronic constriction injury, which is consistent with the findings reported in humans with reflex sympathetic dystrophy.

Animals↗

PubMed1998

The compartments of the hand: an anatomic study.

To determine the nature and number of enclosed myofascial spaces in the hand, an anatomic study that included 21 cadaver hands was conducted using a gelatin injection method. Data were collected from the prepared cross-sections of each specimen. The results showed the thenar space to comprise 2 or more discrete compartments in 52% of the hands. In 76% of the specimens, the hypothenar space demonstrated at least 2 compartments. The adductor pollicis and first dorsal interosseous muscles were discrete compartments in 71% of the hands. The interosseous compartments demonstrated significant variability. The dorsal and palmar interosseous muscles were discrete compartments within the second interosseous compartment in 48% of the hands, within the third interosseous compartment in 67%, and within the fourth interosseous compartment in 33%. Subcompartmentalization of the enclosed myofascial spaces of the hand should be anticipated in cases requiring fasciotomy. Thorough inspection within anatomic areas or generous release of the muscular origin along the metacarpal at the time of fasciotomy is suggested to ensure complete inspection.

Cadaver↗

PubMed1998

The effects of multiple-strand suture methods on the strength and excursion of repaired intrasynovial flexor tendons: a biomechanical study in dogs.

This study was designed to determine the effects of in vivo multistrand, multigrasp suture techniques on the strength and gliding of repaired intrasynovial tendons when controlled passive motion rehabilitation was used. Twenty-four adult mongrel dogs were divided into 4 groups and their medial and lateral forepaw flexor tendons were transsected and sutured by either the Savage, the Tajima, the Kessler, or the recently developed 8-strand suture method. The tendon excursion, joint rotation, and tensile properties of the repaired tendons were evaluated biomechanically at 3 and 6 weeks after surgery. It was found that neither time nor suture method significantly effected proximal and distal interphalangeal joint rotation or tendon excursion when the 4 techniques were compared to each other. Normalized load value (experimental/control) was significantly affected by both the suture method and the amount of time after surgery, however. The Savage and 8-strand repair methods had significantly greater strength than did the Tajima method at each time interval (p < .05 for each comparison). In addition, the 8-strand method had significantly greater normalized load values than did the Savage method at each time interval (p < .05 for each comparison). Normalized stiffness (experimental/control) for the 8-strand repair method was significantly greater than that for the Tajima and Savage methods at 3 and 6 weeks after surgery (p < .05). In addition, the normalized stiffness values for the 6-week groups was significantly greater than those for the 3-week groups (p < .05). It was concluded that the method of tendon suture was a significant variable insofar as the regaining of tendon strength was concerned and that the newer low-profile 8-strand repair method significantly expands the safety zone for the application of increased in vivo load during the early stages of rehabilitation.

Animals↗

PubMed1998

Flexor tendon-pulley interaction after annular pulley reconstruction: a biomechanical study in a dog model in vivo.

The excursion resistance between the canine flexor digitorum profundus tendon and A2 pulley was compared after pulley reconstruction using tendon grafts of either intrasynovial or extrasynovial origin at 10 days, 3 weeks, and 6 weeks after surgery. The changes over time in the underlying flexor digitorum profundus tendon after pulley reconstruction were also evaluated. The excursion resistance for both types of pulley reconstruction was significantly greater than that of the control group at all time periods. The excursion resistance of the extrasynovial tendon graft reconstruction was greater than that of intrasynovial pulley reconstruction at all time periods. In conclusion, pulley reconstruction with intrasynovial tendon grafts may facilitate tendon gliding after surgery.

Animals↗

PubMed1998

Reconstruction of the flexor pulley. The effect of the tension and source of the graft in an in vitro dog model.

Flexor pulleys in the hindpaw digits of twenty-eight adult mixed-breed dogs were reconstructed in order to investigate the influence, on the reconstruction, of the source of the autogenous tissue (intrasynovial compared with extrasynovial tendon) and the tension applied during the repair. The ipsilateral peroneus longus tendon was used to reconstruct the A2 pulley with an around-the-bone technique in twenty-one digits; the graft was sutured at a tension of 0.49, 0.98, and 1.96 newtons in seven digits each. The flexor digitorum profundus tendon of an adjacent digit was used to reconstruct the A2 pulley, at a tension of 0.98 newton, in seven additional digits. The contralateral digits were used as controls for all twenty-eight treated digits. The digits were tested in a custom apparatus designed to measure the frictional force generated between the reconstructed pulley and the tendon beneath it. The frictional force did not differ significantly (p > 0.5) among the three groups repaired with peroneus longus tendon; however, the average value was more than five times that produced in the contralateral, control digits. The average frictional forces created by the flexor digitorum profundus grafts were similar to those in the contralateral, control digits. Reconstruction with the flexor digitorum profundus at a tension of 0.98 newton produced significantly less frictional force (p < 0.05) than that produced by the peroneus longus graft at the same tension. This in vitro model of reconstruction of the A2 pulley demonstrated that tendon from an intrasynovial source (the flexor digitorum profundus) produced less frictional resistance to gliding of the tendon than did tendon from an extrasynovial source (the peroneus longus). This result is consistent with previously published findings that intrasynovial tendons may make better grafts than extrasynovial tendons for the reconstruction of gliding flexor tendons because of decreased friction and better healing qualities. Intrasynovial tendons may also make better grafts for the reconstruction of flexor pulleys.

Animals↗

PubMed1997

Tensile properties of canine intrasynovial and extrasynovial flexor tendon autografts.

This study compared the biomechanical properties of intrasynovial and extrasynovial flexor tendon autografts in an adult canine model. Flexor digitorum profundus (FDP) tissue from the fifth toe of the hindpaw was harvested and transplanted as an intrasynovial graft to the second toe of the left forepaw of each animal. Peroneus longus tendon from the lateral compartment of the hind leg served as the source for the extrasynovial graft that was transplanted to the fifth toe of each dog's left forepaw. The second and fifth FDP tendons of the right forepaw constituted the respective contralateral controls. Postoperatively, each animal underwent a regimen of daily controlled passive mobilization. Three and 6 weeks after grafting, 6 animals were euthanized and their grafts evaluated for gliding function and tensile properties. Results reveal significantly greater angular rotation of the proximal interphalangeal joint in the digits that received intrasynovial grafts relative to those that received transplanted extrasynovial tendon at both 3 and 6 weeks postoperatively. The linear stiffness of the tendons receiving extrasynovial graft significantly exceeded that of the intrasynovial group. These findings correlated with histologic data that postoperative adhesions existed in the specimens with an extrasynovial graft. In addition, the extrasynovial tendon graft complex exhibited significantly higher ultimate loads than intrasynovial tendon graft complex at 6 weeks.

Animals↗

PubMed1997

Biomechanical effects of operative nerve mobilization and transposition in a canine ulnar nerve model.

The purpose of this study was to evaluate the effects that operative mobilization and transposition of the ulnar nerve have on both neural excursion and mechanical properties. Twelve dogs underwent ulnar nerve transposition and postoperative casting. Four animals were killed at 3 weeks and four animals were killed at 6 weeks. Four animals had their casts removed at 3 weeks, were allowed to ambulate, and were killed at 6 weeks. Operated and contralateral control nerves were compared. Neural excursion was measured near the elbow and 12 cm proximally. The nerves were harvested and their mechanical properties determined. Repeated measures analysis of variance revealed significant differences in longitudinal excursion between control and experimental groups at both sites. Ultimate strain, ultimate strength, and modulus were significantly reduced in the experimental groups. No differences were seen in cross-sectional area or stiffness between control and experimental groups. Analysis revealed no independent effect of the rehabilitation method. Results of this study indicate that significant changes in neural excursion, ultimate strain, ultimate strength, and modulus occur following ulnar nerve mobilization and transposition and that these changes persist throughout the early postoperative period.

Analysis of Variance↗

PubMed1997

Suture methods for flexor tendon repair. A biomechanical analysis during the first six weeks following repair.

This review describes the evolution of recently developed multi-strand, multi-grasp flexor tendon suture techniques. Analyses of digital angular joint rotation, tendon excursion, and ultimate tensile load at the time of repair and at three and six weeks following repair allowed comparison of a variety of innovative grasping and non-grasping multi-strand techniques. The first series of experiments describes an analysis of the Tajima, Tsuge, Savage, Kessler, double loop locking suture, and recently developed eight-strand suture techniques at the time of repair. The Tajima, Savage, and eight-strand repair methods were found to have statistically significant improved gliding function compared to those methods that featured external knots (Kessler and Tsuge) and methods that tended to bunch at the repair site (double loop locking suture). With regard to ultimate tensile load, the eight-strand repair was found to have the greatest strength (69N) of all tested methods (p < 0.05). The second series of experiments examined the Tajima, Kessler, Savage, and eight-strand suture methods at three and six weeks following tendon repair. A high percentage of failure within the Kessler repairs precluded their inclusion for final comparative analysis. The results for the remaining three techniques were normalized (experimental/control) to allow inter-group comparison. For intrasynovial tendon repair gliding function, all prepared specimens were found to have significantly less tendon excursion, proximal interphalangeal joint rotation, and distal interphalangeal joint rotation than their respective controls. However, no statistical differences were noted in gliding function between the Tajima, Savage, and eight-strand repair at three and six weeks (p < 0.05). Ultimate tensile testing ascertained that the eight strand method demonstrated significantly greater strength at three (52.6N) and six (70.9N) weeks than both the Tajima and Savage techniques (p < 0.05), while the Savage repair had significantly greater strength than the Tajima repair (p < 0.05). On the basis of these findings, we suggest that early controlled active motion protocols be devised using the multi-strand multi-grasp techniques, as exemplified by the eight strand tendon repair method, in an effort to achieve consistently improved results for intrasynovial flexor tendon repairs.

Animals↗