Search PubMed⌕ Search

Biomedical subjects

J R Sanger

Publications and source records attributed to J R Sanger.

108 records · Page 6Linked to original sources

Warm ischemic damage to the epiphyseal growth plate: a rabbit model.

Warm ischemic growth plate damage was produced in the hindlimbs of 33 New Zealand white rabbits, who were 7 weeks old, by isolating the knee joint on a popliteal vascular pedicle. Zero, 3, 7, and 12 hours of warm ischemia were produced by pedicle occlusion. The 0- and 3-hour ischemic groups showed mild growth disturbances related to the surgical model and were not statistically different at 90 days postoperatively. The 7- and 12-hour ischemia groups showed severe growth disturbances and were statistically different from the 0- and 3-hour groups at all periods measured (p less than 0.05). Large central growth plate lesions were apparent by histologic examination. Twelve hours of ischemia produced a histologic picture identical to growth plate infarction. Increased warm ischemic time correlated with more severe growth retardation and evidence of increased damage to the central area of the growth plate histologically.

Animals↗

The anterior tibial artery flap: anatomic study and clinical application.

Satisfactory replacement of skin defects over the lower leg remains a difficult problem. Various forms of coverage, including, local rotation flaps, muscle flaps, and fascial and free flaps, have their specific indications and inherent disadvantages. In this work, a new axial skin flap based on perforating vessels in the territory of the anterior tibial artery is described. A series of 50 lower leg dissections was carried out in 25 fresh cadavers after latex injection into the femoral artery. Detailed studies of the cutaneous distribution of the anterior tibial artery showed that three main arteries perfuse the anterior lateral portion of the lower leg. The superior lateral peroneal artery and the inferior lateral peroneal artery interseptal cutaneous perforators arise at an average of 25.6 and 17.2 cm from the lateral malleolus, respectively. The superior lateral peroneal artery was present in 100 percent of the specimens, whereas the inferior lateral peroneal artery was present in 70 percent of the specimens. In their course, they give several muscular branches to the peroneus longus and brevis prior to perforating the fascia and arborizing in the subcutaneous tissues of the anterolateral portion of the leg. The average external diameter was 1.6 cm for the superior and 1.4 cm for the inferior lateral peroneal artery. The superficial peroneal nerve accessory artery is the third artery which contributes to the skin of the lower leg. It arises from the superior lateral peroneal artery in 30 percent of cases, from the inferior lateral peroneal artery in 40 percent, and from both in 30 percent. The artery runs along with the superficial peroneal nerve and gives several cutaneous perforators along its descending course. Several cutaneous axial flaps can be fashioned around this anatomy. The operative technique along with demonstrative clinical cases is presented followed by pertinent discussion.

Arteries↗

MR imaging of the carpal tunnel: normal anatomy and preliminary findings in the carpal tunnel syndrome.

MR imaging was performed through the carpal tunnel in 18 wrists of nine normal volunteers and compared with cryomicrotome sections from cadaver wrists. MR reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. The tendons were separated from each other by their tendon sheaths, and this allowed for identification of the various tendons. Anatomic variations encountered in the normal volunteers included anomalous positioning of the origin of the lumbrical muscles within the carpal tunnel in two, persistent median arteries in two, and interposition of the median nerve between the flexor pollicis longus and the superficial flexor tendon to the index finger in one. Preliminary observations in 10 wrists of patients with carpal tunnel syndrome include segmental and diffuse swelling of the median nerve in six, distortion of the nerve in one, and thickening of the tendon sheaths in one. We conclude that MR imaging accurately and reliably displays the normal anatomy of the carpal tunnel and can detect morphologic changes in patients with carpal tunnel syndrome.

Adult↗

Pseudo-anterior interosseous nerve syndrome.

The anterior interosseous nerve syndrome (AINS) is well known. A case is presented that had electromyographic findings limited to the distribution of the anterior interosseous nerve. A small area of sensory loss and slight asymmetry of amplitudes noted on median nerve conduction studies were inconsistent with an AIN syndrome. An antecubital level partial median nerve compromise primarily involving the bundles that form the anterior interosseous nerve was surgically noted. This case illustrates that localization of a peripheral nerve lesion must include consideration of the internal topography of peripheral nerves.

Electromyography↗

The vascular supply to the proximal interphalangeal joint.

Four methods were used to identify the vascular branches that supply the proximal interphalangeal joint in 55 cadaver fingers. They were intra-arterial injection of radiopaque dyes, microscopic dissections of the arterial system, selective injection of specific branches followed by sectioning of the joints and examination of the areas stained, and histologic sectioning. Our studies show that the major branches of the digital artery to the joint arise from the dorsal aspect of the vessel, while smaller branches that run to the soft tissue arise from the palmar side. Three branches supply the proximal interphalangeal joint. The first arises 1.5 to 2.5 cm proximal to the joint and divides into branches to the dorsal skin, the bone proximally, the vincular system, the lateral surface of the joint, and the palmar plate. The other two branches arise distal to the joint space; the first has branches to the palmar aspect of the joint of the middle phalanx and the vincular system. The most distal of the three perfuses the dorsal surface of the joint.

Arteries↗

Retardation of finger growth after injury to the flexor tendons.

The absence of any part of the total mechanical force (i.e., flexor tendons) may be responsible for retardation of bone growth during a child's growth phase. The cause of retardation may be dedifferentiation of cartilage cells at the epiphyseal plate. Four cases in which unrepaired flexor tendons in digits caused retardation of growth illustrate this possible phenomenon. We feel that this is not a well recognized problem and thus deserves mention to stimulate further study. We believe that meticulous primary repair in children is desirable not only to preserve function, but also to prevent growth disturbances.

Age Factors↗

A new microvascular clamp for the production of experimental ischemia.

A new microvascular clamp was developed from inexpensive and readily available materials. This clamp, when properly applied, can provide many hours of vessel occlusion with minimal damage to the vessel intima. This clamp has important applications in producing prolonged experimental ischemia without significant vessel damage and thrombosis. This clamp produced less vessel damage when compared with a standard microvascular clamp for prolonged periods of clamping.

Animals↗

Determining the recipient site for a sensory island pedicle.

When performing a sensory island transfer for restoration of sensibility to an area of pinch, one must be accurate in determining the recipient site. We present a simple and precise means of determining the recipient site for a sensory island transfer by ink-blotting the areas of contact of the thumb and index finger.

Amputation, Traumatic↗

The comparative strengths of internal fixation techniques.

The strengths of internal fixation techniques have been compared by transecting human cadaver metacarpals, reducing and fixing the fractures, and then applying forces to mechanically bend the bone during simulated flexion. Kirschner wires alone, intraosseous wire loops with and without Kirschner wires, and bone plates were tested. Intraosseous loops were tested in three configurations, each with four different wire gauges. Intraosseous loops were stronger than Kirschner wires. Right-angle loops were the best of the intraosseous configurations. The addition of a Kirschner wire strengthened the best dorsopalmar intraosseous loops but not the best right-angle loops. Dorsal bone plates were comparable with the best intraosseous loop configurations of 26-gauge wire.

Fracture Fixation, Internal↗

Aquaplast for nasal splinting.

A nasal splint ideally should be sturdy, moldable, light, easy to apply, and inconspicuous. Plaster, dental compound, and aluminum are currently used but each has limitations. We have found that Aquaplast, a material softened by immersion in hot water, more closely conforms to the qualities of the ideal nasal splint. Aquaplast is sturdy, light, thin, very moldable, easy to apply, and allows for passage of air and moisture.

Female↗

The hand table for pediatric microsurgery.

The technique using the hand table for positioning of infants for microsurgical procedures of the lower extremity is presented. With this technique, the surgeon and assistant are able to sit directly opposite each other with their arms in stable resting position.

Child↗

Lateral arm free flap in oral cavity reconstruction: a functional evaluation.

By use of sophisticated techniques now available from the science of Speech Pathology, we can now document, quantify, and critically analyze the surgeon's reconstructive efforts in the oral cavity. Using these methods, we have evaluated the neurotized lateral arm free flap in six patients receiving oral reconstruction. Two of these are reported in detail. This study has provided a protocol that results in the objective analysis of swallowing, articulation, and range of tongue motion and sensation. All of these tests can be routinely performed by a speech pathologist to document both operative performance as well as patient progress in speech and swallowing. It would appear that we have quantified evidence that the neurotized lateral arm free flap may represent a significant step forward in reducing the morbidity of total and subtotal glossectomy by providing a truly functional reconstruction.

Adult↗

Hyperbaric oxygen therapy and squamous cell carcinoma cell line growth.

Hyperbaric oxygen (HBO) promotes tissue healing by increasing oxygenation. Therefore, HBO therapy is clinically useful for some patients who have undergone major cancer resection and/or radiotherapy to the head and neck. For individual patients, however, there might be undetected viable tumor present at the time of therapy. This study was performed to determine if increased tissue oxygen had a measurable effect on the growth of squamous carcinoma xenotransplants which had been derived from head and neck cancers. After the successful growth of two well-established human squamous cell carcinoma cell lines (183 and 1483), each tumor was transplanted into 20 mice. Every mouse received four transplants of 10(6) cells. Ten mice with 40 xenotransplants in each group were treated with HBO daily for 90 minutes at a pressure of 2 atm, whereas the other 10 formed the control group. The mice transplanted with cell line 1483 were treated for 21 days; mice transplanted with cell line 183 were treated for 28 days. The tumor weight, volume, and histology were evaluated. No significant difference was found between experimental groups. This study suggests that increased tissue oxygen neither significantly increases nor decreases the growth of squamous cell carcinoma.

Animals↗

Management of the mandible in oral cancer.

Modern head and neck surgery has focused on patient rehabilitation and restoration of form and function in the treatment of oral cancers. An important aspect of that process has been the conservation of the mandible in tumor ablation and the reconstruction of the mandible if segmental resection is indicated. This article outlines the science and clinical data behind rim mandibulectomy and the mandibular osteotomy and "swing" to gain access to tumors of the posterior tongues and pharynx. Additionally, the various methods of reconstruction of the mandible in use today as well as the advantages and disadvantages of each are addressed.

Algorithms↗