Biomedical subjects

James R Sanger

Publications and source records attributed to James R Sanger.

15 recordsLinked to original sources

PubMed2006

Sonographic differentiation of digital tendon rupture from adhesive scarring after primary surgical repair.

PURPOSE: After the surgical repair of finger tendons finger range of motion may be limited by tendon rupture or adhesive scarring. Differentiating tendon rupture from adhesive scarring may be difficult clinically. Digital tendon sonography allows the evaluation of tendon integrity in a dynamic setting. Our objective was to determine if sonography could differentiate tendon rupture from adhesive scarring in patients who have had primary tendon repair. METHODS: A retrospective review was performed of the radiographic, clinical, and surgical records of patients referred for finger sonography over a 2-year period. Twenty-eight digits in 21 patients were evaluated for finger tendon disruption after primary surgical repair. The diagnosis of complete tendon rupture was made when 1 or more of the following was identified: a gap separating the proximal and distal tendon margins, visualization of only the proximal tendon margin, or visualization of only the distal tendon margin. Adhesive scarring was diagnosed if the tendon appeared intact with abnormal peritendinous soft tissue abutting or partially encasing the tendon, with synovial sheath thickening, or with restricted tendon motion during dynamic evaluation. RESULTS: Sonography correctly identified tendon rupture or adhesive scarring in 27 of 28 digits with 1 false-positive case (sensitivity, 100%; specificity, 93%; positive-predictive value, 93%; negative-predictive value, 100%; accuracy, 96%). CONCLUSIONS: Sonography is an accurate modality for differentiating tendon rupture from adhesive scarring in patients with prior surgical tendon repair. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic, Level I.

Adolescent↗

PubMed2005

Neuropathological changes in vibration injury: an experimental study.

Vibration syndrome, a clinical condition arising from chronic use of vibrating tools, is associated with a spectrum of neurovascular symptoms. To date, only its vascular pathology has been extensively studied; we sought to determine what direct neurologic injury, if any, is caused by vibration. Hindlimbs of anesthetized rats were affixed to a vibrating platform 4 h a day for 7 days. Study animals were vibrated with set parameters for frequency, acceleration, velocity, and amplitude; control animals were not vibrated. On day 7, nerves were studied by light and electron microscopy. While light microscopy showed minimal histologic differences between vibrated (n=12) and control (n=12) nerves, electron microscopic changes were dramatic. Splitting of the myelin sheath and axonal damage (e.g., myelin balls and "finger ring") were consistently seen in both myelinated and nonmyelinated axons. Despite relatively short vibration, definite pathology was demonstrated, suggesting that vibration syndrome has a direct neurologic component.

Animals↗

PubMed2005

Vibration-induced disruption of retrograde axoplasmic transport in peripheral nerve.

Hand-arm vibration syndrome (HAVS) results from excessive exposure to hand-transmitted vibration. Whether the peripheral nerve damage characteristic of HAVS is a direct result of vibration or is secondary to vascular insufficiency remains unclear. The purpose of this study was to explore the effect of vibration exposure on axoplasmic transport in peripheral nerves and soleus motor neurons. Sciatic nerves and motor neurons from rats following two 5-h periods of vibration exposure demonstrated disruption in retrograde transport compared to normal. After 10 days of vibration (5 h/day), axoplasmic transport failed to recover within 24-48 h in most rats. This study demonstrates that disrupted axoplasmic transport is an early consequence of short-term vibration exposure. The effects of vibration on axoplasmic transport also appear to be cumulative. This study provides a new biological way to evaluate measures to prevent early vibration injury.

Animals↗

PubMed2005

Functional improvement with digital prosthesis use after multiple digit amputations.

PURPOSE: Patients who sustain traumatic amputation of multiple fingers suffer both a functional and psychologic loss. Previous studies of prosthesis use for finger amputees have focused primarily on the psychologic benefits. Clinically our group noticed a functional improvement on hand function tests when patients with multiple digit amputations used a prosthesis. Given the expense of multiple finger prostheses we sought to determine if they led to a consistent functional improvement in these patients. METHODS: Ten consecutive patients performed a battery of hand function tests and rated their ability to perform a variety of activities of daily living both with and without their prosthesis using the Disabilities of the Arm, Shoulder, and Hand questionnaire. RESULTS: Our results show a significant improvement in 3-finger-pinch strength and grip strength and a trend of improvement of tip-pinch, lateral-pinch, and grip strength in dynamometer positions 1, 2, 3, and 4 in these patients when tested with and without their prostheses. Function in activities of daily living, as assessed by the Disabilities of the Arm, Shoulder, and Hand questionnaire, was improved globally with prosthesis use. In addition, significant improvement was noted in several specific activities including opening a jar, writing, and turning a key, among others. CONCLUSIONS: These results show that prosthesis use provides a functional benefit to these patients in multiple activities.

Activities of Daily Living↗

PubMed2005

Serratus anterior in vivo contractile force study.

BACKGROUND: A major limitation of functional muscle transfer for facial and intrinsic hand reanimation is the inability to predict the force that will be generated by the transplanted muscle. METHODS: The authors studied the contractile force of the slips of the serratus anterior in situ in 10 patients and tested the gracilis muscle in four subjects as a control. RESULTS: Mean contractile force generated by each serratus slip was 0.178 pound (range, 0.019 to 0.797 pound). This compares favorably with the maximum force generated by smiling (0.307 pound). Muscle strength correlated strongly with age (r = -0.805, p = 0.005). The lowest slip generated less force than those above it (0.133 pound versus 0.191 pound); this difference did not reach statistical significance. When the strength of the lowest slip is compared with the more superior slips as a percentage of total force generated by the slips (to compensate for the effect of age on muscle strength), the lowest slip was significantly weaker (18.6 percent of total force versus 25.5 percent of total force, p = 0.013). Mean contractile force generated by the gracilis was 0.963 pound, significantly different from that generated by a serratus anterior slip (p = 0.009). CONCLUSIONS: Each serratus slip could potentially be used to generate a separate force vector for facial reanimation. Further separation of the flap along preexisting fascial planes may allow generation of up to 10 independent force vectors, making the serratus anterior muscle flap an attractive option for facial reanimation and possibly intrinsic hand muscle reconstruction.

Adolescent↗

PubMed2004

Irrigation pressure and vessel injury during microsurgery: a qualitative study.

Irrigation solution is routinely used in microsurgery. While the anticoagulation solution may aid in anastomotic patency, the direct effect of pressure irrigation can have a detrimental effect on the vessel. An experimental study was performed to determine the effect of irrigation pressure on the vessel wall. Histological evaluation with hematoxylin and eosin (H&E) stain and scanning electron microscopy (SEM) was performed on the arteries of New Zealand white rabbits irrigated with lactated Ringer's solution at pressures of 80 mmHg, 100 mmHg, and 500 mmHg. H&E staining and SEM microscopy demonstrated injury to the endothelial cells and internal elastic lamina at pressures of 100 mmHg or greater. Controlling microsurgical irrigation pressure to less than 100 mmHg may help to avoid vessel injury.

Animals↗

PubMed2004

Ultrastructural analysis of peripheral-nerve regeneration within a nerve conduit.

The purpose of this study was to observe the cellular components of regenerating peripheral nerves within a nerve conduit. Rat sciatic nerves were placed in a silicone conduit with a 5-mm gap between nerve endings. At weekly intervals for 6 weeks, 70-nm sections of nerve tissue from the conduit were obtained for ultrastructural observation. The principal cellular components by the end of the first week were macrophages and fibroblasts. By the end of the second week, both myelinated and unmyelinated nerve fibers began to pass through the entire conduit. By the end of the fifth week, nerve fibers were present at various levels of maturity, with no evidence of inflammatory or immunologic response. By the end of the sixth week, the percentage of nerve fibers was 86 percent of the cellular components. This analysis provides cellular data on which to base additional research regarding functional outcomes when using nerve conduits.

Animals↗

PubMed2004

Detailed neurovascular anatomy of the serratus anterior muscle: implications for a functional muscle flap with multiple independent force vectors.

A functional muscle free flap with multiple muscle segments that could be oriented independently to produce different force vectors would be beneficial in facial reanimation and upper extremity reconstruction. The serratus anterior muscle has this potential because two or more individual muscle slips can be transferred on a single vascular pedicle. Although serratus anterior muscular anatomy has been studied previously, little attention has been given to the intramuscular anatomy. Muscle slips 5 through 9 (and 10, if present) in 50 specimens from 27 cadavers were studied following intraarterial latex injection. Eight specimens were injected with a radiopaque material (latex/diatrizoate/lead mixture) for x-ray delineation of the intramuscular vascular pattern. Slips 5 through 9 are consistently supplied by a single dominant branch of the thoracodorsal artery and innervated by the long thoracic nerve. Dissection revealed that the long thoracic nerve and its branches invariably follow the artery and divide proximal to the corresponding arterial division. There is a consistent vascular pattern to each muscle slip, in which the serratus artery gives rise to common slip arteries, each of which supplies adjacent muscle slips. The mean length of a muscle slip from its origin on the rib periosteum to the division of the common slip artery is 9.6 cm. These findings imply that the slips may be separated to the level of these common slip arteries, with up to five slips transferred on a single neurovascular pedicle and each slip oriented independently to provide multiple muscle force vectors. With these possibilities, the reconstructive surgeon may be able to restore more natural facial animation and better intrinsic muscle function in the upper extremity.

Adolescent↗

PubMed2004

The serratus anterior subslip: anatomy and implications for facial and hand reanimation.

The ideal donor muscle for facial and hand reanimation has yet to be found. Donor muscles commonly used today, such as the gracilis and pectoralis minor, are limited by bulkiness and the number of force vectors they can provide. In the authors' study of 50 fresh cadaver serratus anterior muscles, they further describe neurovascular anatomy of the muscle slip (i.e., the portion of the muscle that inserts on a rib) and subslip (superficial or deep subdivision of the slip after division along a loose areolar plane). All 260 slips could be separated into a deep and a superficial subslip, yielding a total of 520 subslips. A branch of the serratus artery (a terminal branch of the thoracodorsal artery serving the lower five to seven slips of the muscle) and a branch of the long thoracic nerve were identified for each of these. Deep subslips were thinner than superficial subslips, both at the origin of the slip on the rib periosteum (2.4 mm versus 3.0 mm, p < 0.0001) and centrally at the serratus artery (3.3 mm versus 4.0 mm, p < 0.0001). In addition, the subslips of the most inferior slip were thinner than those of more superior slips, both at the origin of the slip (2.3 mm versus 2.8 mm, p < 0.0001) and at the serratus artery (3.0 mm versus 3.8 mm, p < 0.0001). Fine anastomosing vessels were present between the slips and the subslips. The average number of anastomosing vessels present between adjacent slips was 1.7, and 2.1 anastomosing vessels were present between the subslips of a given slip. Given the thinness of these vessels (all less than 0.2 mm) compared with those of the vascular pedicle of the subslip (mean, 0.7 mm; all greater than 0.4 mm), the authors believe these can be safely divided without compromising subslip vascularity. After division of these vessels, a mean length of 9.6 +/- 1.5 cm is available to allow independent orientation of each subslip. When the serratus muscle flap is separated into its component subslips, a maximum of 10 possible force vectors may be transferred on a single vascular pedicle. Subslips are significantly thinner than donor muscles commonly used today. These two advantages offer the potential for significant functional and aesthetic improvement when the serratus anterior muscle flap is used for face and hand reanimation. Mimetic muscles such as the orbicularis oculi and orbicularis oris could possibly be reconstructed in their proper anatomical positions.

Adolescent↗

PubMed2003

Return to work outcomes after work-related hand trauma: the role of causal attributions.

PURPOSE: This study examined the relationship between workers' judgments of responsibility for their accidents (causal attributions) and work-site avoidance after work-related injuries. METHODS: Ninety-two hand-injured workers referred for psychologic treatment of posttraumatic stress and depressive symptoms were assessed for their beliefs about the cause(s) of their accidents. Causal attributions were obtained before and after psychologic intervention. RESULTS: Workers who blamed coworkers or equipment for their injuries were more likely to resist returning to former work activities than workers who judged themselves responsible for their accidents. In addition those with relatively minor injuries were as much at risk for work-site avoidance as those with more severe injuries. Age, gender, and length of employment with current employer were unrelated to avoidance. CONCLUSIONS: These results suggest the importance of causal attributions as potential predictors of work-site avoidance after traumatic work-related hand injuries, and support the risk for psychologic symptom development after less-severe injuries.

Absenteeism↗

PubMed2002

A modified end-to-side method for peripheral nerve repair: large epineurial window helicoid technique versus small epineurial window standard end-to-side technique.

This study evaluated 2 end-to-side nerve repair techniques for ability to induce nerve sprouting and muscular recovery. Twenty-four rats underwent identical surgeries. The helicoid method of neurorrhaphy was used on the left (large epineurial window) side and the standard end-to-side (small epineurial window) repair on the right side of each rat to repair the peroneal nerve. The helicoid configuration markedly increases the area from which axons can sprout into the recipient nerve. At 11 months after surgery, axons were counted in donor and recipient nerves, and muscle moist weight of the extensor digitorum longus (EDL) and tetanic force were measured. Muscle volume, tetanic force, and moist weight of EDL muscles were significantly higher on the left side (helicoid) than on the right (end-to-side). Histologic analysis and nerve axon counting of the recipient peroneal nerve showed significantly more regenerative nerves on the left than on the right. There were no significant differences between sites above and below the repair site in the donor tibial nerve in regard to mean number of nerve fibers. Helicoid nerve repair can entice more nerve fiber sprouts from the intact donor nerve, improve muscular recovery, and maintain donor nerve health.

Anastomosis, Surgical↗

PubMed2002

Nerve repair at different angles of attachment: experiment in rats.

Sixteen rats underwent two procedures to test the efficacy of oblique vs. transverse nerve repair. On the left, the peroneal nerve was transected at an oblique angle (30-degree) with subsequent oblique end-to-end repair performed. On the right, the peroneal nerve was transected at a transverse angle (90-degree) with subsequent end-to-end repair. At 3.5 months postoperatively, the moist muscle weight of the extensor digitorum longus (EDL) and tetanic force were measured, and axons were counted in donor and recipient nerves. Muscle volume, tetanic force, and moist weight of EDL muscles were statistically significantly higher on the left side (oblique) than on the right (transverse). Histologic analysis with nerve axon counting of the recipient peroneal nerve revealed significantly more regenerated nerve fibers on the left than on the right. The authors concluded that oblique nerve repair enhances nerve-fiber sprouting from the proximal donor nerve by increasing the coapted surface area, thus improving muscle recovery.

Animals↗

PubMed2002

Anterolateral thigh fasciocutaneous island flaps in perineoscrotal reconstruction.

This study presents the authors' experience using the anterolateral thigh fasciocutaneous flap for complex perineal and scrotal reconstruction. Anterolateral thigh fasciocutaneous island flaps were performed in seven patients between January and June of 2000 (six male, one female; mean age, 52 years; age range, 9 to 72 years). Four of the seven patients had scrotal or perineal defects after multiple debridements for Fournier's gangrene. Two of these four had exposed testicles. Three flaps were used for recurrent ischial ulcers. A true septocutaneous perforator (type 1) running between the rectus femoris and the vastus lateralis muscles was found in only two patients. In four patients, the cutaneous perforators were found to be intramuscular, originating from the descending branch (type 2). In the other patient, the musculocutaneous perforator originated from the lateral circumflex femoris artery independently (type 3). In these cases, intramuscular dissections were performed to follow each perforator to its main trunk. Mean follow-up was 8 months (range, 5 to 10 months), and all flaps survived. Three patients developed minor wound dehiscence in the posterior aspect of the perineal wound because of fecal contamination and skin maceration. Both wounds healed secondarily. Scrotal reconstruction with the anterolateral thigh flap gave an excellent aesthetic result. The authors conclude that the anterolateral thigh flap is a reliable flap for perineoscrotal reconstruction.

Adolescent↗

PubMed2002

The vascular supply of the extended tensor fasciae latae flap: how far can the skin paddle extend?

The vascular supply of the tensor fasciae latae flap and of the lateral thigh skin was studied in 10 cadavers to evaluate whether the lateral thigh skin toward the knee could be incorporated into an extended tensor fasciae latae flap. Within each cadaver, vascular injection of radiopaque material preceded flap elevation in one limb and followed flap elevation in the contralateral limb. Flaps raised after vascular injection were examined radiographically to evaluate the vascular anatomy of the lateral thigh skin independent of flap elevation. When vascular injection was made into the profunda femoris, the upper two-thirds of the flaps was better visualized than the distal third. When the injection was made into the popliteal artery, the vasculature of the distal third of the flaps was better visualized. Flaps raised before vascular injection were examined radiographically to delineate the anatomical territory of the vascular pedicle that had been injected. In these flaps, consistent cutaneous vascular supply was only seen in the skin overlying the tensor fasciae latae muscle, confirming that musculocutaneous perforators are the predominant means by which the pedicle of the tensor fasciae latae flap supplies the skin of the lateral thigh. Extended tensor fasciae latae flaps were elevated bilaterally in one cadaver, and selective methylene blue injections were made into the lateral circumflex femoral artery on one side and into the superior lateral genicular artery on the contralateral side. Methylene blue was observed in the proximal and distal thirds of the skin paddles, respectively, leaving unstained midzones. The vascular network of the lateral thigh skin could be divided into three zones. The lateral circumflex femoral artery and the third perforating branches of the profunda femoris artery perfuse the proximal and middle zones of the lateral thigh skin, respectively. The superior lateral genicular artery branch of the popliteal artery perfuses the distal zone. The middle and distal zones meet 8 to 10 cm above the knee joint, where the skin paddle of the tensor fasciae latae flap becomes unreliable. These data indicate that if the aim is to incorporate the skin over the distal thigh in an extended tensor fasciae latae flap without resorting to free-tissue transfer, then either a carefully planned delay procedure or an additional anastomosis to the superior lateral genicular artery is required.

Adult↗

PubMedDate not supplied

Acute tarsal tunnel syndrome following partial avulsion of the flexor hallucis longus muscle: a case report.

An acute posterior tibial nerve compression from a partially ruptured flexor hallucis longus (FHL) muscle is reported. This etiology for acute tarsal tunnel syndrome has not been previously described. A 17-year-old male sustained multiple injuries in a motor vehicle accident, including a tibial shaft fracture and a posterior medial right ankle laceration of the same limb. The injured limb had no sensation on the plantar aspect of the foot and heel, decreased active great toe flexion, and associated leg pain. Exploration of the posterior tibial nerve for presumed laceration revealed the nerve to be intact, but compressed in a tense tarsal tunnel from a retracted partially ruptured flexor hallucis longus tendon. Decompression of the tunnel and resection of the devascularized muscle resulted in complete neurologic recovery.

Acute Disease↗