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Biomedical subjects

J R Werther

Publications and source records attributed to J R Werther.

At least 19 recordsLinked to original sources
PubMed2001

Use of the extensor retinaculum as a donor site for bone-ligament-bone grafts.

The recent introduction of bone-ligament-bone grafts for ligament reconstruction in hand surgery has led to a search for suitable graft donor sites. The extensor retinaculum had been suggested, but harvesting details were still lacking. We therefore studied the anatomy of the extensor retinaculum, with radiography and morphometric measurements. Ten cadaver wrists were dissected; the thick portion of the retinaculum and its insertions on the radius in the different extensor compartments were studied. The compartments were wire-marked, and AP radiographs taken of each specimen. The retinaculum spanning the first three compartments was removed with the bony ridges it inserted on, and the inter-ridge retinaculum length was measured. A comparison of our dissections with the radiographs showed that only the radial compartments 1, 2 and 3 had constant bony insertions on both ridges, making them suitable for bone-ligament-bone grafting. The mean compartment length was 11.7 mm (compartment 1), 17 mm (compartment 2) and 7.3 mm (compartment 3) respectively. Thus, the extensor retinaculum can be relied upon to provide bone-ligament-bone grafts from the first three compartments, for possible use in ligament reconstructions in the hand and wrist.

Aged↗
PubMed2001

[Biomechanical evaluation of osteosynthesis with cannulated screws for Ponteau-Colles fractures in a bird model].

INTRODUCTION: The use of cannulated screw without protrusive head in Colles fractures could avoid some of the drawbacks of conventional pinning. In order to compare the mechanical resistance of Kirshner wires versus cannulated screws we designed a animal model of Colles fractures and tested three types of osteosynthesis: A: K-wires, B: Herbert cannulated screw, C: specific cannulated screws. METHOD: After creating a 10 mm defect in three sets of 10 fresh turkey tibia, 3 types of osteosynthesis were done and tested in compression with an Adamel Lhomargy machine: set A: K-wire fixation, set B: Herbert screws fixation and set C: specifics screws fixation. RESULTS: The compression strength needed for failure of the fixations were: for the K-wires (set A): 52 N +/- 17; for the Herbert screws (set B): 93 N +/- 39; for the specifics screws (set C): 160 N +/- 48; (p < 0.0001). DISCUSSION: The use of an animal model makes the experimentation easier and the sampling more homogeneous. In this model, resistance to compression of the cannulated screw was better than K-wires and the specific cannulated screw better than Herbert screw. Therefore clinical trial of osteosynthesis with cannulated screw in Colles fracture could be considered.

Animals↗
PubMed1999

Assessment, documentation, and treatment of a developing facial asymmetry following early childhood injury.

Prepubertal trauma is often implicated as the cause of asymmetric growth of the mandible. A series of photographs taken before and after early childhood injury to the orofacial complex illustrates the development of a three-dimensional dentofacial deformity in a patient. The diagnosis and combined surgical orthodontic treatment plan to correct the facial asymmetry and malocclusion are discussed.

Adult↗
PubMed1998

Changes in nasal tip projection and rotation after septorhinoplasty: a cephalometric analysis.

PURPOSE: This prospective study reports on changes in nasal tip projection and nasal tip rotation before and after septorhinoplasty analyzed cephalometrically. PATIENTS AND METHODS: Forty patients undergoing primary septorhinoplasty were studied prospectively. Lateral cephalometric radiographs taken in the natural head position were obtained before and 6 to 45 months (mean, 17.1) after surgery. In 10 patients, serial radiographs were taken at 6 and 12 months, and in seven patients they were taken at 12 and 24 months after surgery. Nasal tip projection (NTP) was defined as the distance between articulare (Ar) and pronasion (PRN). Nasal tip rotation (NTR) was defined as the change in the angle (N-Ar-PRN) after surgery. A surgical goal to increase, decrease, or maintain NTP and NTR was assigned to each patient before surgery. RESULTS: NTP changed in the desired direction in 16 of 40 patients (40%). NTR changed in the desired direction in 25 of 40 patients (63%). In the patients studied serially, NTP decreased an average 0.7 mm between 6 and 12 months (P = .018), and 0.6 mm between 12 and 24 months (P = .071). CONCLUSIONS: Decreased NTP and NTR were the most easily achieved surgical objectives. Maintaining or increasing NTP is less predictable. Typically, there is a progressive loss of NTP after surgery independent of the surgical goal. Cephalometric analysis is a useful tool to measure changes in NTP and NTR after septorhinoplasty.

Adolescent↗
PubMed1998

Cutaneous approaches to the lower lid and orbit.

In any discussion of surgical exposure, it is important to remember that of chief importance is what is done in the operative field, rather than how the site is exposed. Selection of approach is based on tradeoffs that must be weighed by the surgeon and tailored to the deformity for a given patient. Despite a recent surge in the popularity of the transconjunctival technique, periorbital surgery by a cutaneous approach is still a valid means of access for a variety of esthetic and particularly trauma procedures. There are few solid data comparing the two approaches, and what does exist shows little or no significant difference between them. A cutaneous approach spares the conjunctiva, bypasses transconjunctival-related complications, and eliminates the need for lateral canthotomy for access. The subtarsal lid crease incision appears to offer the benefits of the orbital rim incision with respect to speed, exposure, and low incidence of lid malposition, with cosmetic scar appearance that is comparable to the subciliary incision.

Cicatrix↗
PubMed1998

[Late infection of breast implant, complication of colonic perforation. Review of the literature. Role of preventive treatment].

The authors report a cases of breast implant infection, 40 years after augmentation mammoplasty. The infection developed 6 weeks after colonoscopy complicated by acute peritonitis due to colonic perforation. Bacteroides fragilis, a usual organism of the gastrointestinal tract flora, was identified in the two septic sites (peritoneal and periprosthetic). Contamination of the implant was haematogenous in a context of bacteraemia. Other authors have already suspected this route of contamination without any bacteriological proof. The risk of infection of breast implants is known, but the late infection rate is poorly documented. It is probably very low in view of the rare cases reported in the literature. Breast implants are not at high risk of sepsis, in contrast with prosthetic heart valves. The authors therefore do not recommend any particular preventive treatment in the case of distant infection or dental treatment. Women with breast implants must be informed and reassured: late infection of their implant is possible, but very unlikely. Recognition and prevention of this risk could be based on better long-term follow-up of breast implants.

Aged↗
PubMed1997

Results of reoperation after failed modified condylotomy.

PURPOSE: This retrospective study reports the reoperation rate for failure after modified condylotomy. MATERIALS AND METHODS: A consecutive series from each of two surgeons constituted the study group of 361 joints in 235 patients. Reoperation rates were calculated for all joints and by type of disc displacement. RESULTS: A second operation occurred in 4.2% of all joints. However, the cumulative rate of reoperation was 4.4%, because one of the joints required a third operation. Although the rate of reoperation varied (0% to 6.5%) according to the type of disc displacement, the differences were not statistically significant. All joints requiring reoperation had a displaced disc, and more than half had lost nearly all the joint space gained by the primary operation. CONCLUSION: The rate of reoperation for modified condylotomy is low. Risk factors for reoperation appear to be recurrent or residual disc displacement and loss of joint space after the first operation. Bilateral operation was not a risk factor.

Adolescent↗
PubMed1996

External rhinoplasty approach for repair of posttraumatic nasal deformity.

Up to 50% of patients who have suffered a nasal fracture may seek reconstructive surgery because they are dissatisfied with their appearance and/or ability to breathe. Distortion of native anatomy and dissection planes increases with severity of the injury. The external rhinoplasty approach is a biologically sound technique that offers several advantages over endonasal access for the repair of complex nasal deformities. In 30 consecutive posttraumatic rhinoplasty cases over a 2-year period, 27 (90%) patients underwent correction of their deformities via the external rhinoplasty approach. No technique-specific sequelae were encountered, and all patients were satisfied with their respective result and the healing of the transcolumellar incision. This article reviews the advantages, disadvantages, and contraindications of the external rhinoplasty approach in the posttraumatic patient.

Cartilage↗
PubMed1995

Disk position before and after modified condylotomy in 80 symptomatic temporomandibular joints.

OBJECTIVE: Our primary objective was to determine the frequency of disk reduction after modified condylotomy and whether the type of displacement affected outcome. DESIGN: We classified reducing disk displacements from magnetic resonance images of 80 symptomatic temporomandibular joints before modified condylotomy. Disk position was reassessed after surgery. RESULTS: The disk and condyle typically move in reciprocal directions. The disk was reduced by surgery in 79% of the joints. The rate of reduction varied by the type of displacement, but the differences between the groups were not statistically significant. CONCLUSION: This finding reaffirms that modified condylotomy has a high rate of disk reduction. The unexpected observation that the increase in joint space resulting from the surgery typically permitted a variable degree of spontaneous movement of the disk has implications for the nature of osteoarthrosis and internal derangement and for surgical treatments intended to reduce the risk.

Adolescent↗
PubMed1992

Accelerated endochondral osteoinduction in the absence of bone matrix particles in a rat model system.

Ethanol-precipitated proteins obtained from demineralized rat bone powder (DBP) by 4M guanidine-HCl extraction have been shown to reproducibly induce ectopic endochondral bone formation when subcutaneously implanted in rats in the absence of bone matrix particles. Histologic and biochemical analysis revealed a temporal sequence of chondrocyte differentiation, calcified cartilage formation, neovascularization, osteoblast differentiation, bone formation, osteoclastic bone remodeling, and hematopoietic marrow development that is complete by 21 days. In contrast to previous reports, these results clearly show an osteoinductive response independent of the presence of insoluble extracellular bone matrix. Compared with conventional DBP implants, the guanidine-extractable protein (GE) produces an accelerated and more robust osteoinductive response. Histologically, the initial chondrogenic response at days 6 to 9 is greatly amplified. Alkaline phosphatase specific activity peaks at day 9, several days earlier than for DBP, and is sixfold higher. Calcium accumulation in GE implants at day 12 is fivefold greater than with DBP, and all mineral is localized within the matrix of newly calcified cartilage and new bone. Osteoclasts are up to ninefold more abundant in the rapidly remodeling GE ossicle, making space for hematopoietic marrow. Delivery of GE coprecipitated with inert bone matrix particles was also more effective than DBP, although the response was somewhat attenuated compared with GE alone. Bony filling of 4-mm defects in rat mandibular rami was elicited by 10 mg of GE and followed an endochondral process with increased neovascularization compared with DBP and unimplanted controls. This guanidine-extractable protein fraction should prove useful for inducing quantities of chondrocytes and osteoclasts for in vitro study, and for analysis of osteoinductive requirements.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1986

Analgesic regimens for third molar surgery: pharmacologic and behavioral considerations.

The level of pain following the extraction of impacted third molars was evaluated in 75 patients. Participants were administered acetaminophen 1,000 mg or a placebo before surgery. After surgery, acetaminophen 650 mg was administered either at fixed intervals or as needed to relieve pain. When acetaminophen was administered before surgery, the onset of peak pain was delayed and patient discomfort was decreased 3, 4, and 5 hours after surgery. Patients following the fixed interval regimen after surgery experienced more pain overall and requested the backup narcotic analgesic more frequently. Of the regimens tested, patients preferred the regimen of acetaminophen 1,000 mg administered before surgery with acetaminophen administered as needed for pain after surgery.

Acetaminophen↗