X-ray evaluation of interferential femoral screw positioning in ACL reconstruction

BACKGROUND: Conjunctival intraepithelial neoplasia has traditionally been found at the limbus in elderly individuals. Recently, this ocular tumor has been observed in younger patients. OBJECTIVE: To investigate the potential association of human immunodeficiency virus infection with the emergence of this atypical presentation of conjunctival intraepithelial neoplasia. DESIGN, SETTING, AND PARTICIPANTS: Records of patients at the Bascom Palmer Eye Institute (Miami, Fla) in whom conjunctival intraepithelial neoplasia was diagnosed between January 1, 1991, and December 31, 1993, were reviewed. Attempts were made to contact those patients younger than 50 years for clinical evaluation and human immunodeficiency virus serologic testing. RESULTS: Conjunctival intraepithelial neoplasia was diagnosed in 73 patients during the study period. Of the nine patients younger than 50 years, six were available for serologic testing. Three (50%) of these individuals were found to be positive for human immunodeficiency virus. CONCLUSION: Human immunodeficiency virus testing and counseling should be considered in patients younger than 50 years in whom conjunctival intraepithelial neoplasia is diagnosed.     

Biomechanical study of nine different tibia locking nails

We have previously found that T22 ([Tyr5, 12, Lys7]-polyphemusin II) exhibits strong anti-human immunodeficiency virus (HIV) activity comparable to that of 3'-azido-2', 3'-dideoxythymidine (AZT). The inhibition mechanism of T22 on HIV-replication has not been elucidated precisely yet, and hence the target molecules of T22 have not been identified. However, our recent research suggested that T22 exerts its effect by blocking virus-cell fusion at an early stage of HIV infection and that T22 might interact with an HIV envelope protein and/or a T-cell surface protein, both of which are critical for HIV infection. In this paper we demonstrated that T22 binds specifically to both gp120 (an envelope protein of HIV) and CD4 (a T-cell surface protein) and that both bindings can be inhibited by an anti-T22 antibody, using biosensor technology (BIAcoreTM) based on the principles of surface plasmon resonance. Linearization by the BIAcoreTM system (BIAlogue software) and nonlinear least squares analysis by curve fitting with exponential equations showed that both interactions have close dissociation constants (approximately 10(-7) M). The present study suggests that T22 inhibits the virus-cell fusion process through binding to both gp120 and CD4.     

Proximal femoral focal deficiency

Proximal femoral focal deficiency (PFFD) is an uncommon congenital defect that involves the femur and acetabulum in varying degrees. It may occur with or without fibular hemimelia and can be unilateral or bilateral in presentation. Children with PFFD and their families are faced with many treatment decisions, both nonsurgical and surgical. Nursing care is central in the care of these children and their families both for psychosocial support and teaching during the decision-making process and for being a patient advocate to help meet postoperative and rehabilitation goals.     

Failure of femoral head fixation: a cadaveric analysis of lag screw cut-out with the gamma locking nail and AO dynamic hip screw

The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under static loading conditions on 12 pairs of cadaveric femoral heads, to establish the failure loads due to screw cut-out for the two implant lag screws. The gamma nail appeared to reduce the tendency to cut-out in the osteoporotic bone (soft) associated with elderly patients in whom these devices are commonly used (p < 0.05). In high density bone (hard) the gamma lag screw also appeared to be stronger, because the DHS showed a tendency to bend. The larger diameter of the gamma nail lag screw resists bending and appears to reduce the risk of cut-out compared with the DHS.     

A simple jig to ease the insertion of distal screws in intramedullary locking nails

Distal locking of closed intramedullary nails can be time consuming and expose the surgeon to unnecessary increased ionization radiation. A simple jig is described which facilitates the insertion of the second distal locking screw, using the first drill hole as a pilot. This tool reduces the operating and the ionizing radiation exposure time.     

A new technique for the distal locking of solid AO unreamed tibial nails

Forty patients with aggressive (intermediate-grade and high-grade) non-Hodgkin's lymphoma (NHL) were treated primarily with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy regimen, and then evaluated for prognostic features. Age, tumor stage, performance status, number of extranodal disease sites and serum concentrations of lactate dehydrogenase (LDH) were considered prognostic features. All the patients treated with the CHOP regimen were grouped into four risk categories, including low (L), low-intermediate (LI), high-intermediate (HI) and high (H) according to the International Prognostic Index. Twenty-one of 23 patients (91.3%) in the L plus LI risk groups and 5 of 17 patients (29.4%) in the H plus HI risk groups had complete response and the difference between these percentages was statistically significant (P<0.001). The overall survival rate (2 yr) of 23 patients in the L+LI risk group was 52.1% and of 17 patients in H+HI risk group was 11.7% and this difference was statistically significant (P<0.05). Our results indicated that the CHOP regimen is not effective in the HI+H risk groups of patients with aggressive NHL. New experimental approaches are needed for these patients.     

Proximal and distal femoral centralizers in modern cemented hip arthroplasty

Third generation cementing techniques using intramedullary restrictors, low porosity cement with pressurization, lavage, and cement-stem bond enhancement do not prevent implant malalignment and inadequate cement mantle thickness. This has led to the development of modular proximal and distal centralizers to control the alignment of the femoral component and maintain an adequate thickness of the cement, thereby theoretically decreasing the rate of aseptic loosening. A retrospective analysis was performed of 100 primary cemented centralized femoral components. At an average followup of 5.7 years (range, 4-8 years), the average Harris Hip Score was 90. There were no cases of aseptic loosening, osteolysis, or impending failure. Ninety-one percent of femoral stems were implanted with satisfactory alignment with an optimal cement thickness. However, six distal centralizers and one proximal centralizer fractured at the time of insertion and voids frequently were seen in and around the distal centralizer. Although centralizers improve prosthesis alignment and cement mantle thickness, the long term effects of centralizer fracture and distal cement voids need to be observed to determine if centralizers improve previous implant survival.     

Patients treated for nonunions with plate and screw fixation and adjunctive locking nuts

Locking nuts were used as an adjunct to plate fixation in 48 procedures in 44 patients. All the procedures were done by one surgeon during a 4-year period. The patients in this study were treated for nonunion or malunion and thus had difficult technical problems, such as cortical defects or holes left from previous hardware. The use of standard implants were generally unreliable for additional fixation. The locking nuts were used as a cortical substitute in 26 instances, to create a fixed angle relationship between the plate and the screw in 14 instances, to elevate the plate off the bone to help increase vascularity in five instances, and to increase purchase in severely osteoporotic bone in three instances. Complete followup was obtained on 43 of the 44 patients. Forty of the 43 patients achieved complete union after their reconstructive procedure. Three patients had continued nonunions with eventual hardware failure and required reoperation. The use of the locking nuts enabled the surgeons to obtain stable fixation at the time of reoperation with eventual union of all of the ununited bones. The success of the use of this implant is best gauged by the fact that the surgeon could place screws effectively where cortical defects existed, allow improved purchase in osteoporotic bone, and create a fixed angle plate screw relationship that would have been difficult to do without the locking nuts.     

Mechanical failure of the intramedullary hip screw in a subtrochanteric femoral fracture

The Gamma nail, an implant specifically designed for intertrochanteric and subtrochanteric femoral fractures, has been criticized for its high risk of secondary shaft fractures. A modified design, the intramedullary hip screw has recently been introduced to correct this complication. We present a case of mechanical failure of this new implant that occurred in a pathological subtrochanteric fracture. The centering sleeve of the implant became loose and migrated while the head screw penetrated the acetabulum. Refixation was successful.     

Proximal femoral osteotomy as the primary operation for young adults who have osteoarthrosis of the hip

We report the results of proximal femoral osteotomy that was performed to treat osteoarthrosis in twenty-three consecutive young adults (twenty-five hips) who had a mean age of thirty-eight years (range, eighteen to fifty-three years). The mean duration of follow-up was seven years (range, two to twelve years). With conversion to a total hip replacement as the end point, the rate of survival at twelve years was 67 per cent (95 per cent confidence interval, 37 to 88 per cent). Four hips (16 per cent) were converted to a total hip replacement at a mean of eight years after the osteotomy. For the patients who did not have conversion to a total hip replacement, the mean score for pain, according to the system of Merle d'Aubigné and Postel as modified by Charnley, improved from 3.4 points preoperatively to 5.1 points postoperatively, the mean score for walking ability improved from 3.9 to 4.7 points, and the mean score for range of motion improved from 3.2 to 4.2 points. These results compare favorably with those following other forms of operative treatment of osteoarthrosis of the hip in young adults. In addition, the osteotomy does not preclude subsequent replacement arthroplasty if one is necessary.     

Forming independent components via temporal locking of reconstruction architectures: a functional model of the hippocampus

To investigate whether the degree of differentiation in feline mammary carcinoma (FMC) can indicate the post-surgical survival time (PST), tumours were surgically resected from 55 cats and histologically graded according to a method derived from human breast cancer studies. One year after the resection, 26 cats (47.3%) were alive while 29 (52.7%) had died as a consequence of FMC. Formalin-fixed, paraffin wax-embedded sections stained with haematoxylin and eosin were used to classify the FMCs initially, according to the WHO system. Histological grading was then performed on the basis of three main features: degree of tubule formation, nuclear and cellular pleomorphism, and accurate mitotic count obtained from a defined area. Immunohistochemical examination with an anti-actin antibody was used for the accurate detection of "in situ" carcinomas. Age and histological type were not significantly correlated with the PST. Seven tumours (12.7%) were graded as well-differentiated carcinoma (WDC; grade I), 33 (60%) as moderately differentiated carcinoma (MDC; grade II), and 15 (27.3%) as poorly differentiated carcinoma (PDC; grade III). The tumour-related death rates after the first post-surgical year were 0 in cats with WDC, 14 (42.4%) in those with MDC, and 15 (100%) in those with PDC. Six cats with tumours showing extensive myoepithelial differentiation were all alive after 1 post-surgical year. The grading system seemed to have a good predictive value in respect of grades I and III of FMC but not for grade II. Myoepithelial differentiation may be relevant to clinical prognosis in FMC.     

Dose variation at bone/titanium interfaces using titanium hollow screw osseointegrating reconstruction plates

PURPOSE: To evaluate dose variations at bone/titanium interfaces in an experimental model designed to simulate postoperative radiotherapy in patients with mandibular reconstructions using a titanium hollow-screw osseointegrating reconstruction plate (THORP) system. MATERIALS AND METHODS: The model consisted of a 25 x 25 x 10 mm3 block of fresh bovine femoral diaphysis, to the surface of which a segment of THORP system reconstruction plate was fixed by means of a solid titanium screw 4 mm in diameter and 10 mm in length. Using specially designed thermoluminescent dosimeters (TLD) 2 mm in diameter and 0.13 mm in thickness, dose measurements were carried out at four distances from the screw axis (0.1, 0.3, 0.6, and 1 mm). 60Co and 6-MV photon beams were used at incidences both perpendicular and parallel ("axial") to the screw axis. RESULTS: For 6-MV X-ray beams incident perpendicular to the screw axis, the maximum dose enhancement (due to backscatter) and the maximum dose reduction (due to attenuation) at the bone/titanium interface were 5% (+/- 2%) and 6% (+/- 2%), respectively. The corresponding values for 60Co beams were 6% (+/- 5%) and 10% (+/- 5%). For the axial incidences, a maximum dose enhancement of 5-7% was noted for both 6-MV X-rays and 60Co for beams incident on the surface containing the THORP plate segment, whereas beams incident on the opposite surface induced only a very small dose enhancement (2-3%). CONCLUSION: Using a new experimental model, TLD measurements showed only marginally significant dose variations at bone/titanium interfaces around THORP screws, all measured values being very close to the uncertainty limits (+/- 5%) associated with the method. For both 60Co and 6-MV beams, dose variations appeared smaller for axial than for perpendicular incidences. Because photon beams used in head and neck cancer treatment are most often directed parallel to the screw axes, these results suggest that failures of prosthetic osseointegration are unlikely to be explained by an overdosage at the bone/titanium interface.     

Difficulty in removal of certain intramedullary nails

Intramedullary nailing is the most common treatment for displaced diaphyseal fractures of the femur and tibia. Gerhard Küntscher introduced the technique of intramedullary nailing to clinical practice in the 1940s, and this method has been the focus of many authors with regard to indications, technique, complications, and outcome. The five cases presented here represent a complication not often reported in recent years: the difficulty in removing an intact intramedullary nail. Inspection of the interlocking nails in four of the cases presented reveals a specific design characteristic: the cross sectional design of the nail prevents the distal, unslotted end of the nail from being extracted from the medullary cavity. This problem is preventable by a change in nail design or the development of absorbable implants.     

All-inside anterior cruciate ligament reconstruction using semitendinosus tendon and soft threaded biodegradable interference screw fixation

A modification of anterior cruciate ligament (ACL) reconstruction using a minimally invasive and endoscopic all-inside technique is presented. Both the femoral and tibial socket are approached through the joint so that there is no open tibial tunnel, which otherwise often causes significant pain and discomfort during early rehabilitation. The autologous semitendinosus tendon is harvested with a bone plug attached to its tibial insertion. The triple-stranded semitendinosus tendon is looped around the adjacent bone plug and fixed at the original tibial attachment site of the ACL using a soft threaded biodegradable poly-(D,L-lactide) interference screw. The screw is inserted endoscopically in an inside-out direction. In the femoral socket the graft is fixed without a bone plug directly to the tunnel wall using the biodegradable screw. The free part of the graft is thus not longer than the intra-articular distance, which may increase stiffness of the construct.     

Late lateral femoral condyle fracture after anterior cruciate ligament reconstruction. A case report

Inter-individual differences in brain-immune interactions have been demonstrated previously in mice using lateralization as a behavioral trait of population heterogeneity. Lipopolysaccharide (LPS), which is known to induce neurochemical, neuroendocrine, and immune responses depending on lateralization, is also able to induce sickness behavior, via the production of interleukin-1 (IL-1). The objective of this study was to determine whether lateralization can influence the behavioral response to LPS and to IL-1. To test this hypothesis, adult female C3H mice, previously selected for paw preference in a food reaching task, were injected intraperitoneally (i.p.) with 0.75 microg LPS or 0.75 microg recombinant IL-1beta. Sickness induced by these molecules was measured by depressed social behavior, increased immobility, loss of body weight, and reduced food intake during the 6 h following injection. LPS-induced sickness was similar in right- and left-pawed mice. In contrast, IL-1-induced sickness behavior was dependent on behavioral lateralization. IL-1-induced depression of social investigation was more pronounced in right-pawed mice than in left-pawed animals. Likewise, IL-1-induced immobility was more important in right-pawed mice. There was a similar trend for food intake to be lower and loss of body weight to be higher in right-pawed mice than in left-pawed animals. These results demonstrate that right-pawed mice are more sensitive to IL-1-induced sickness than left-pawed animals. They extend our previous data showing a greater susceptibility to stress of right-pawed animals. The existence of inter-individual differences in the reactivity to stress or immune activation may be useful to study the mechanisms of the various strategies used by an individual in response to environmental aggressions.     

Permanent loss of finger nails from sensitization and reaction to acrylic in a preparation designed to make artificial nails

Six years ago a patient suffered a severe allergic reaction from sensitization to methyl methacrylate in a mixture of materials designed to make artificial nails. There was marked erythema, edema, and pain of the eponychial and paronychial tissues with persistent paresthesia of the finger tips. Gradual destruction of the nail plates developed and since no regrowth of the nails resumed in six years, the loss of the finger nails is found to be permanent.     

Proximal femoral fractures in patients over 75 years. Vital and functional prognosis of a cohort of 78 patients followed during 2.5 years

PURPOSE OF THE STUDY: The purpose of this study was to highlight factors influencing vital and functional prognosis at 2.5 years of elderly people being treated for a proximal femoral fracture. MATERIAL: The study was based on 78 patients more than 75 years old admitted to the orthopedic department for emergency treatment. After post-operative care, patients were transferred to a geriatric readaptation unit. The average patient age at the time of surgery was 85 years. METHODS: This was a retrospective study. Survival graphs were established for the entire population as well as for the sub-populations characterized by a studied parameter. Mortality factors were compared via a univariable analysis. A multivariable logistical regression analysis isolated the factors explaining mortality at 12, 18, and 30 months and survival at 30 months, as well as factors explaining functional prognosis at 1 year. RESULTS: The overall mortality rate was 41 per cent, 48.5 per cent of deaths occur within the first year. Factors which are harmful for vital prognosis are the following: high degree of dependence before the fracture, the existence of a neuropsychiatric pathology, and age factor (more than 85 years). 61.5 per cent of surviving patients were independent for daily activities. 77 per cent of surviving patients lived in their usual place of residence. Factors which were harmful for functional prognosis were the following: type of the fall, symptomatic of an underlying pathological state, and existence of a neuropsychiatric pathology. Nutrition was also a predictive factor concerning the patient's out come. DISCUSSION: The average age of the studied population was higher than in most studies in literature. The treatment is mainly based on hip arthroplasty. The group of patients of over 85 have the highest mortality rate. However, a better survival rate at 18 months has been observed for patients older than 90 years. The delay before surgical care was significantly negative if longer than 6 days. However, a delay of 3 to 6 days was not significantly harmful for survival. Within the studied population, the maximum autonomy gain was observed during the first 6 months. The type of non-accidental fall, symptomatic of an associated pathology, was a factor for functional prognosis which has not been often mentioned. So was the biological deficit of nutrition. Social status acted as an indicator of functional status evolution. CONCLUSION: Therapeutic choices can only be guided by assessments of patients' vital and functional prognosis. A sophisticated or even expensive device should be demanded for patients with favorable prognosis. For patients with precarious functional and vital prognosis, priority should be given to less invasive techniques with immediate walking. The cost of the device should be correlated with patient's functional investment.