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Biomedical subjects

R Sanders

Publications and source records attributed to R Sanders.

At least 145 records · Page 8Linked to original sources
PubMed1993

Trabeculectomy: effect of varying surgical site.

Trabeculectomy reduces intraocular pressure by fistula formation into a subconjunctival bleb. The operation site traditionally has been at the superior corneo-scleral junction with a failure rate of 10-30%. The causes of trabeculectomy failure can be broadly classified into intraocular, scleral and extraocular. Extraocular factors account for the majority of failures, the main cause being increased subconjunctival fibrosis. Hitherto the effect of varying the site of filtration surgery on intraocular pressure control has not been studied. We therefore carried out a prospective study to evaluate the optimum site for trabeculectomy. Sixty patients were randomised to undergo a superior, nasal or temporal trabeculectomy. Patients who underwent a nasal trabeculectomy had significantly lower intraocular pressures 18 months after surgery (p < 0.05), with 30% having an intraocular pressure of < or = 10 mmHg.

Aged↗
PubMed1993

The beta 4 subunit cytoplasmic domain mediates the interaction of alpha 6 beta 4 integrin with the cytoskeleton of hemidesmosomes.

The alpha 6 beta 4 integrin is structurally distinct from all the other known integrins because the cytoplasmic domain of beta 4 is unusually large and contains four type III fibronectin-like modules toward its C-terminus. To examine the function of the beta 4 cytoplasmic tail, we have expressed full-length and truncated human beta 4 cDNAs in rat bladder epithelial 804G cells, which form hemidesmosome-like adhesions in vitro. The cDNA encoded wild-type beta 4 subunit associated with endogenous alpha 6 and was recruited at the cell surface within hemidesmosome-like adhesions. A recombinant form of beta 4, lacking almost the entire cytoplasmic domain associated with alpha 6, reached the cell surface but remained diffusely distributed. A beta 4 molecule lacking almost the entire extracellular portion did not associate with alpha 6 but was correctly targeted to the hemidesmosome-like adhesions. Thus, the cytoplasmic portion of beta 4 contains sequences that are required and may be sufficient for the assembly of the alpha 6 beta 4 integrin into hemidesmosomes. To localize these sequences we examined the properties of additional mutant forms of beta 4. A truncated beta 4 subunit, lacking the most C-terminal pair of type III fibronectin homology domains, was incorporated into hemidesmosome-like adhesions, but another recombinant beta 4 molecule, lacking both pairs of type III fibronectin repeats, was not. Finally a recombinant beta 4 molecule, which was created by adjoining the region of the cytoplasmic domain including all type III repeats to the transmembrane segment, was efficiently recruited in hemidesmosome-like adhesions. Taken together these results suggest that the assembly of the alpha 6 beta 4 integrin into hemidesmosomes is mediated by a 303-amino acid region of beta 4 tail that comprises the first pair of type III fibronectin repeats and the segment between the second and third repeats. These data imply a function of a specific segment of the beta 4 cytoplasmic domain in interaction with cytoskeletal components of hemidesmosomes.

Animals↗
PubMed1993

Retrograde reamed femoral nailing.

Closed, reamed, antegrade nailing remains the standard of care for femoral shaft fractures. This technique however, may be less attractive in the management of femoral shaft fractures associated with (a) ipsilateral acetabular, pelvis, or femoral neck fractures; (b) polytrauma requiring multiple simultaneous surgical procedures; and (c) pregnancy. We now report on our experience with the retrograde femoral nailing as a treatment option in these situations. Between 4/88 and 10/90, 29 retrograde femoral nailing in 24 patients were attempted. Average age was 29.3 (16-74) years. Five fractures were open. Fracture location was isthmal in 14 and infraisthmal in 15. The comminution was classified according to Winquist and Hansen: I(10), II(7), III(7), and IV(5). Nailing was possible in 28/29 cases. Insertion was made through an extraarticular medial condylar portal. Nail diameter ranged from 10 to 13 mm. An AO Universal Femoral Nail was used in the first 11 cases; all subsequent fractures were stabilized using an AO Universal Tibial Nail because its design appeared better suited to this technique. Follow-up was possible for 25 fractures in 21 patients and averaged 16.0 (range, 11-27); months 23/25 (92%) fractures healed within 12 weeks. No case was associated with an infection, loss of reduction, or nail failure. Knee flexion averaged 122 degrees; only two knees had an extensor lag of > 5 degrees. Intraoperative complications included three cases of crack propagation at the insertion site, and four infraisthmal malreductions (two valgus, two flexion). Based on these results, we feel that retrograde reamed femoral nailing is a suitable alternative to antegrade nailing and should be considered in situations where proximal access is neither possible nor desirable.

Acetabulum↗
PubMed1993

Ophthalmic disease in patients with unrecognized HIV infection.

HIV disease has a long and relatively asymptomatic incubation period before the onset of AIDS. The ophthalmic manifestations of AIDS are well recognized. Little is known of the incidence or range of ophthalmic disease seen in the latent period of HIV disease. A retrospective analysis of 125 case notes of HIV 1 antibody positive patients was undertaken. Of these, 15 (12%) had previously attended the ophthalmic department, at which stage their HIV status was unknown. Eight patients were diagnosed as being HIV positive within twelve months of attending the ophthalmic department. There was a predominance of ophthalmic infections, as opposed to trauma which is the commonest cause for ophthalmic casualty referral. Some of the ophthalmic presentations seen were the initial presenting sign of HIV disease. There were also cases of serious trauma and a mixture of other ophthalmic diseases. We discuss these ophthalmic findings and their relevance to HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Exposure of the orthopaedic surgeon to radiation.

A prospective study of sixty-five orthopaedic procedures performed with fluoroscopic assistance was undertaken to determine the risk to the primary orthopaedic surgeon with regard to radiation. Radiation was monitored with the use of a universal film badge placed outside the collar of a lead apron, and a gas-sterilized thermoluminescent dosimeter ring worn on each hand. The rings were changed with every operation, but the same film badge was transferred from surgeon to surgeon. The hand dominance of the surgeon, the duration of the operative procedure, the type of operation, and the total time that fluoroscopy had been used were noted. The study was conducted during twenty-one intramedullary nailing procedures (thirteen involving distal locking), forty open reductions with internal fixation (plates and screws), and four external-fixation procedures. All of the badges and rings were submitted for a report regarding radiation exposure. No relationship was found between a ring with a positive reading for exposure to radiation and the duration of the operation. Similarly, there was no correlation between a positive reading and the surgeon's hand dominance. The mean duration of the fluoroscopy was 2.3 minutes for the group for which the rings did not show a positive reading and 4.7 minutes for the group for which the rings did show a positive reading. This was a significant difference (p < 0.0001). There was no positive reading for exposure to radiation from any ring that had been worn during a procedure in which the fluoroscope had been used for less than 1.7 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Nails↗
PubMed1993

The radiologic evaluation of calcaneal fractures.

Although computed tomography (CT) scanning has revolutionized the treatment of calcaneal fractures, simple studies such as Böhler's view still have a role in the diagnosis and management of these fractures. This article reviews the benefits and limitations of these imaging techniques for calcaneal fractures.

Calcaneus↗
PubMed1993

Operative treatment in 120 displaced intraarticular calcaneal fractures. Results using a prognostic computed tomography scan classification.

From January 1987 to September 1990, 132 displaced intraarticular calcaneal fractures were treated operatively using a lateral approach, lag screws, and side plate without bone graft. To evaluate the results, a classification for intraarticular calcaneal fractures was developed, based on standardized coronal and transverse computed tomography (CT) scans of both feet. Type 1 fractures were nondisplaced (and received nonoperative treatment); Type II were two-part or split fractures; Type III were three-part or split depression fractures; and Type IV were four-part or highly comminuted articular fractures. Results were evaluated using the Maryland Foot Score and repeat CT scans. One hundred twenty cases were available for a minimum of one year follow-up evaluation (range, 12-56 months; mean, 29.3 months). Roentgenographic evaluation of calcaneal body dimensions showed restoration of heel height (98%), width (110%), and length (100%) to virtually normal in all cases, regardless of preoperative displacement. Roentgenographically, articular reduction was anatomic in 68 of 79 (86%) Type II fractures, 18 of 30 (60%) Type III fractures, and 0 of 11 (0%) Type IV fractures. Excellent or good clinical results occurred in 58 of 79 (73%) Type II fractures, 21 of 30 (70%) Type III fractures, and one of 11 (9%) Type IV fractures. When excellent and good clinical results were compared by year, a distinct learning curve appeared (1987, 27%; 1988, 54%; 1989, 74%; 1990, 84%). Despite an improved outcome for Type II and III fractures with increasing surgical experience, the results of operative intervention in Type IV fractures were no better, even after four years.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcaneus↗
PubMed1992

Cavernous haemangioma of the nasal bones.

A case report of a cavernous haemangioma arising in the nasal bones is described, together with a discussion of the relevant literature. The condition, although rare, can be reliably diagnosed pre-operatively.

Bone Neoplasms↗
PubMed1992

A comparison of prophylactic, topical and subconjunctival treatment in cataract surgery.

Prophylactic subconjunctival antibiotics and steroids have been used in cataract surgery since the early 1950s. However despite their widespread acceptance, there has, to date, been no direct comparison of subconjunctival and topical routes of administration. We therefore carried out a prospective comparison of the effects of subconjunctival and topical administration of antibiotics and steroids in sixty patients undergoing elective, uncomplicated, extracapsular cataract extraction and posterior chamber lens implantation. The patients were examined by a single observer on the first and third post-operative days and two and six weeks following surgery. The observer was blinded to the patient treatment group. Significantly higher degrees of conjunctival injection and anterior chamber activity were noted in those who received subconjunctival injections compared with those who received topical treatment. There were no significant differences between the two groups in best corrected visual acuity, central corneal oedema, cystoid macular oedema, intraocular pressure and infection. We conclude that prophylactic subconjunctival therapy in uncomplicated cataract surgery is not necessary.

Administration, Topical↗
PubMed1992

The salvage of open grade IIIB ankle and talus fractures.

Between 1983 and 1989, 11 open grade IIIB ankle or talus fractures were treated according to protocol including debridement, temporary placement of antibiotic beads, soft tissue coverage (including seven free vascular tissue transfers), intravenous antibiotics and fusion using an anterior plate, and bone graft. All patients had a minimum of three separate hospitalizations. Each had at least five operative procedures performed with an average of 8.2/patient (range: 5-12). The total in-patient hospital stay averaged 61.6 days (20-107 days) and in patient costs averaged $62,174.43/patient (range: $33,535.06-$143,847.45). Overall hospital cost averaged $1,009.32/day. Follow-up averaged 47.8 months (range 32-85 months), with an average time to union of 4.4 months. Fusion rate and muscle flap success was 100%. Although fusion and eradication of infection in this specific group of patients was possible, significant functional and psychosocial disability remained. Eight of eleven patients had significant pain, difficulty with stairs, and limited ambulation. All changed jobs or were unemployed. Patients with open grade IIIB tibiotalar injuries with significant bone loss may therefore benefit from early amputation. A multicenter randomized clinical outcome study is needed.

Activities of Daily Living↗
PubMed1992

Indirect reduction and percutaneous screw fixation of displaced tibial plateau fractures.

Indirect reduction and percutaneous screw fixation were attempted in 20 displaced tibial plateau fractures in 20 patients. Closed, indirect reduction was successful in 18 fractures; two others, both Schatzker type II fractures, required open reduction. The 18 fractures were followed for an average of 16.2 months (range, 12-24 months). Of the fractures successfully reduced with indirect techniques, 13 were reduced anatomically (72.2%), and five were considered nonanatomic (27.8%). Four of the five fractures with a nonanatomic reduction were type II fractures. Clinically, there were six excellent (33%), 10 good (56%), and two fair (11%) results. No fracture lost reduction; no patient developed an infection. Indirect techniques could effectively reduce only split fragments. Depressed fragments could not be reduced reliably with either ligamentotaxis or percutaneous elevation with a tamp. There was no correlation between radiographic reduction and clinical outcome. It did not matter whether two, three, or four screws were used to stabilize the fracture.

Adolescent↗
PubMed1992

Analysis of set screw and side-lock connector reliability.

A retrospective review of complications with connectors and lead-to-header interfaces was performed following 649 pacing procedures between 1980 and 1990. There were 88 lead revisions (13.6%), 81 device replacements or modifications (12.5%), and 480 new implants (74%) using devices of five manufacturers. Two basic connector types were studied, one utilizing a set screw and the other using a side-lock compression fitting. The set screw makes electrical contact and mechanically secures the lead connector pin with a set screw insulated by a self-sealing grommet or an integral or separate set screw cover. The side-lock makes electrical contact with an automatic spring mechanism while the plastic lead terminal is secured in the connector block of the pacemaker by a Delrin side-lock compression fitting. Four hundred fifty-nine set screw connector devices were followed for up to 12 years with 14 complications (3.1%) whereas 82 side-lock connector devices were followed for up to 5 years with one complication (1.2%). The set screw and side-lock connectors were reliable over the period of follow-up. Although the complication rate appeared lower with the side-lock, follow-up was shorter and the number of implants smaller. With the leads used in this study, the side-lock proved to be a desirable feature due to simplicity, speed, safety, and ease of use. One limitation is the requirement for a precise IS-1 connector terminal diameter.

Electrodes, Implanted↗
PubMed1992

Stabilization of acetabular fractures in elderly patients.

Eighteen patients who were sixty years or older and had an acute displaced fracture of the acetabulum were managed with open reduction and internal fixation. The average age of the patients was sixty-seven years (range, sixty to eighty-one years). Nine fractures were a result of a motor-vehicle accident, and nine occurred in a fall. Nine patients had multiple associated injuries, and most (sixteen patients) had other complex acetabular fractures. All of the patients had open reduction and internal fixation with either the ilioinguinal approach (thirteen patients) or the Kocher-Langenbeck approach (five patients). All patients were managed postoperatively with early mobilization and physical therapy. All fractures united, and only one patient had a partial loss of reduction. Four patients who had a concentric reduction had a gap of as much as three millimeters in the articular surface due to comminution of the fracture. The complications included two pulmonary emboli, which resolved with anticoagulation, and one undetected intra-articular fragment, which led to an additional operation. No infections or iatrogenic nerve injuries were noted. Seventeen of the eighteen patients were followed for at least two years (average, thirty-one months). These patients had an average Harris hip-score of 90 points postoperatively. The treatment was regarded as having failed in only one patient. Open reduction and internal fixation of selected displaced acetabular fractures in the elderly can yield good results and may obviate the need for early and often difficult total hip arthroplasty.

Acetabulum↗
PubMed1991

Further evaluation of radical surgery following radiotherapy for advanced parotid carcinoma.

A series of 30 patients who have been treated for advanced carcinoma of the parotid gland using radiotherapy followed by radical surgery is presented. Three patients deteriorated during preoperative radiotherapy and remained unfit for surgery; the remaining 27 underwent radical parotidectomy with block dissection of the neck. Twelve patients received additional radiotherapy after operation. Of those patients undergoing surgery, three have been lost to follow-up, 17 have died and seven remain alive; the period of follow-up ranges from 3 to 133 months. Fourteen patients remained free of recurrent disease at death or when last seen, and six patients developed a local recurrence at a medium period of 10.5 (range 3-36) months after surgery. For all 30 patients, the cumulative proportion surviving for 5 years was 30 per cent.

Adult↗
PubMed1991

Microbiological aspects of burns at Mount Vernon Hospital, UK.

Bacterial infection in 100 burned patients over a 10-month period has been studied. The commonest colonizing organism was Staph. aureus (69 per cent), followed by E. coli (35 per cent). Pseud. aeruginosa accounted for only 28 per cent of isolates. The role of the different bacterial species in burns pathology is discussed. Group G haemolytic streptococci were isolated from 10 per cent of patients and caused graft failure in some cases. Only 3 per cent of patients developed septicaemia and all were due to Staph. aureus. Our approach to management of infection in burns, especially the policy on systemic antimicrobial chemotherapy, is described.

Anti-Infective Agents↗