Total hip arthroplasty for femoral fractures other than capital physeal fractures in dogs: 14 cases (2012-2020).

OBJECTIVES: The goals of this retrospective study were to assess the clinical and radiographic outcomes in dogs with proximal femoral fractures, other than capital physeal fractures, treated via total hip arthroplasty. MATERIALS AND METHODS: Medical records as well as pre-operative, immediate post-operative and 2 to 3 months post-operative radiographs of 14 dogs with femoral head and neck fractures treated via total hip arthroplasty were reviewed. A Liverpool Osteoarthritis in Dogs questionnaire was completed by owners to assess long-term outcomes. RESULTS: Seven femoral head fractures, and seven femoral neck fractures were included. Four of the femoral head fractures were acute in nature, the three remaining femoral head fractures and all seven femoral neck fracture cases were chronic fractures. Malorientation of the femoral stem was more common in the chronic femoral fracture cases when compared to the acute femoral fracture cases. Two of the acute fracture cases and five chronic fracture cases experienced a change in femoral stem position post-operatively. One femoral fissure fracture occurred and was repaired intraoperatively. One case had a post-operative complication that resulted in implant removal. All dogs had good to excellent owner-perceived outcome. CLINICAL SIGNIFICANCE: Femoral head and neck fractures, and in particular the chronic cases, represented a challenging subset of cases presenting for total hip arthroplasty, resulting in suboptimal stem alignment in many cases. However, clinical outcomes were considered good to excellent in all dogs in the study, indicating that total hip arthroplasty is a viable treatment option for these types of fractures.

Simple ostectomy to address quadriceps impingement caused by distal femoral malunion in four dogs.

Four dogs were evaluated for chronic pelvic limb lameness. Radiographs revealed distal femoral malunion with caudo-proximal displacement, resulting in impingement of the quadriceps from the distal aspect of the proximal femoral segment. All dogs presented with femoral shortening and increased femoral procurvatum when compared with the normal contralateral femur. There was minimal angular or rotational misalignment. Treatment consisted of ostectomy of the fracture segment that was causing quadriceps impingement, with debridement of proliferative fracture callus proximal to the trochlear groove in all dogs. No attempt was made to address sagittal plane deformities. Long-term orthopaedic examination with objective gait analysis in three dogs revealed minimal to no lameness in two and mild residual lameness in one dog. Long-term radiographic analysis revealed fracture-site remodelling with an increase in femoral length and a return of near-normal femoral procurvatum in all dogs. Owner-assessed long-term outcome was excellent in all dogs.

En-bloc femoral cement removal after failure of cemented total hip replacement in two dogs.

In two dogs with periprosthetic infection after total hip replacement, the femoral cement mantle was retrieved by proximal extraction without an invasive osteotomy or cortical fenestration. En-bloc femoral cement removal was performed by injection of polymethylmethacrylate cement into the central mantle void left after stem removal, and by threading a positive profile pin into the newly injected cement. Once the PMMA had polymerized, the pin was withdrawn with the entire mantle attached. This technique should be considered in patients with circumferential deterioration of the femoral bone-cement interface in which the diameter of the femoral isthmus would not obstruct withdrawal of the cement mantle.

Immunolocalization of matrix metalloproteinases in partial-thickness defects in pig articular cartilage. A preliminary report.

BACKGROUND: Partial-thickness defects in mature articular cartilage do not heal spontaneously. Attempts at repair often result in limited integration between the repair tissue and the surrounding cartilage, with formation of chondrocyte clusters adjacent to a zone of cartilage necrosis. In wound repair, spatially and temporally controlled expression of matrix metalloproteinases and their inhibitors have been implicated in proteolytic degradation of damaged extracellular matrix components, but the sequence of events following damage to cartilage is unknown. To determine this sequence, we studied the distribution of matrix metalloproteinases and their inhibitors during early in vivo repair of partial-thickness defects in pig articular cartilage. METHODS: With use of a model that elicits the ingrowth of mesenchymal cells into partial-thickness defects, partial-thickness defects were created in knee joint cartilage. The distributions of matrix metalloproteinase-1, 2, 3, 9, 13, and 14; tissue inhibitors of metalloproteinase-1 and 2; and the neoepitope DIPEN341 specifically generated following matrix metalloproteinase cleavage of aggrecan were determined by immunolocalization of repair tissue and surrounding cartilage excised from immature pigs during the first eight weeks of repair and from adult minipigs at eight days and three weeks. RESULTS: Synthesis of matrix metalloproteinase-13 was usually confined to hypertrophic chondrocytes in immature cartilage and to the radial zone in adult cartilage. Following injury, strong induction of matrix metalloproteinase-13 synthesis was observed in chondrocyte clusters surrounding lesions in all of the animals. The migration of macrophages into defects was prominent at two and eight days, with synthesis and deposition of matrix metalloproteinase-9 onto damaged cartilage matrix and newly synthesized matrix in the defect. The DIPEN341 neoepitope was localized to damaged cartilage matrix at eight days and six weeks, indicating partial degradation of aggrecan. Focal synthesis of matrix metalloproteinase-1, 3, and 14 and of tissue inhibitor of metalloproteinase-1 occurred at later times, suggesting continuous remodeling of the increasingly compact repair tissue. CONCLUSIONS: The expression of matrix metalloproteinase-13 by normal hypertrophic chondrocytes and the induction of synthesis in chondrocyte clusters adjacent to the zone of cartilage necrosis suggest that this enzyme participates in the pericellular proteolysis required for lacunar expansion. The localization of matrix metalloproteinase-9 to damaged cartilage matrix suggested matrix proteolysis, which was confirmed with DIPEN341 localization. Reduced matrix metachromasia persisted and was colocalized with DIPEN341 at six weeks. However, under the conditions investigated, there was only limited proteolytic degradation in the zone of cartilage necrosis. This may render the zone mechanically weakened, thereby contributing to subsequent instability of the region, and may form a barrier to integration of repair tissue with viable cartilage. CLINICAL RELEVANCE: Osteoarthritis initially involves the superficial layers of cartilage. The development of procedures to promote the healing or repair of early defects will have major advantages in terms of disease alleviation as well as economic importance. Identification of the enzymes involved in the early repair of partial-thickness defects in articular cartilage is clinically relevant because proteolysis of damaged matrix has to take place in order for repair tissue to integrate with surrounding healthy cartilage.

Computed tomography for the diagnosis of a lumbosacral nerve sheath tumour and management by hemipelvectomy.

Computed tomography was used to define the gross extent of a lumbosacral plexus nerve sheath tumour in a 10-year-old crossbred dog. The tumour was also visualised ultrasonographically, which enabled a percutaneous biopsy to be taken. Hemipelvectomy was performed to achieve a clean margin of surgical excision.

Radiographic evaluation of acetabular component position in dogs.

OBJECTIVE: To assess the usefulness of standard radiographic projections for determining acetabular cup position and to compare 2 radiographic methods for calculation of the angle of lateral opening of the acetabular cup. STUDY DESIGN: In vitro radiographic study. METHODS: Acetabular components were mounted on a custom-built inclinometer. The effect of varying the angles of lateral opening, inclination, version, and centering of the x-ray beam on the radiographic appearance of the cup was investigated. The angle of lateral opening was calculated trigonometrically after direct measurement and by means of computer-aided image analysis. RESULTS: Using a ventrodorsal radiograph, the computer-aided measurement of angle of lateral opening was accurate to within 5 degrees when the true angle of lateral opening was > or = 40 degrees. In the case of direct measurement, the calculated angle was accurate to within 5 degrees only when the true angle was > or = 60 degrees. An increasing angle of inclination was associated with reduced accuracy of calculation of the angles of lateral opening and version. Standard radiographic assessment of acetabular version and inclination was not found to be clinically useful. The displacement of the x-ray beam, which would cause significant error in the determination of lateral opening, is unlikely to be exceeded in practice. Cup size had no significant effect on the accuracy of the results. CONCLUSIONS: Computer-aided image analysis can be used to calculate angles of lateral opening to within 10 degrees throughout the range of acetabular positions seen in practice and is appropriate for postoperative documentation of cup position. The angles of inclination and version should be interpreted with caution.

Rigid and extreme: a geometric representation of personality disorders in five-factor model space.

Personality disorder rigidity and extremity can be geometrically defined and operationalized within the 5-factor model (FFM) of personality. A series of geometric and substantive assumptions were derived and then tested in samples of college students (N = 1,323) and psychiatric patients (N = 86). Normal and disordered personalities were found to coexist in a variety of regions of the FFM multivariate space. Within regions, the profiles of normal and disordered personalities were very similar in characteristic configuration but notably different in profile variability. Personality-disordered individuals tended to be located in the perimeters or outer regions of the FFM space, as indicated by their longer vector lengths. These findings generalized across 2 measures of personality disorders and across 2 measures of normal personality traits.

Evaluation of risk factors for luxation after total hip replacement in dogs.

OBJECTIVE: To identify risk factors for luxation after canine total hip replacement (THR). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: 256 client-owned dogs that underwent THR. METHODS: Patient data surveyed included signalment, body weight, diagnosis, prior hip surgery, implant size, intraoperative complications, and angle of lateral opening of the acetabular component. RESULTS: Postoperative complications were recorded in 20 cases (7.8%). The most common complication was dorsal luxation which occurred in 12 dogs (4.7%). The interval between joint replacement and luxation ranged from 1 to 116 days (mean, 44 days). In 1 case, luxation was attributable to failure of the repair of an intraoperative fracture of the greater trochanter. Excluding this case, the mean angle of lateral opening in those dogs that sustained luxation was 62 degrees (range, 46 degrees - 75 degrees). The mean angle of lateral opening overall was 48 degrees (range, 18 degrees - 76 degrees). The angle of lateral opening was the only factor that had a statistically significant effect on whether luxation occurred (P = .035). Acetabular revision, performed primarily to reduce the angle of lateral opening, was performed in 8 dogs and successfully prevented subsequent luxation. CONCLUSION: Luxation of the prosthesis is substantially under the control of the surgeon. It is recommended that the acetabular cup be inserted at an angle of lateral opening of 35 degrees to 45 degrees. In those cases of THR luxation in which an inappropriate angle of lateral opening is identified, acetabular revision arthroplasty generally results in a good clinical outcome.

Metacarpal fractures associated with pancarpal arthrodesis in dogs.

OBJECTIVE: To report the prevalence of third metacarpal bone fractures after dorsal plating for pancarpal arthrodeses in dogs and to identify predisposing factors. STUDY DESIGN: Retrospective clinical study. ANIMALS: Fifty-four client-owned dogs. METHODS: Pancarpal arthrodesis was performed using dorsally applied 2.7- or 3.5-mm bone plates. Medical records and radiographs were retrospectively evaluated to identify those dogs with metacarpal bone fractures after pancarpal arthrodesis and to determine the angle of arthrodesis, the percentage of the third metacarpal bone covered by the bone plate, and the percentage width of the bone occupied by the screw. Radiological evidence of arthrodesis at follow-up examination 6 weeks postoperatively was recorded. Long-term results were obtained by telephone follow-up with the owners. All lame dogs were evaluated clinically and radiographically. RESULTS: Metacarpal fractures occurred in 6 of 54 dogs. One of these dogs had a stress fracture of the third metacarpal 10 months after implant removal and was not included in the statistical analysis. Fractures occurred through the distal screw hole in four dogs and involved two metacarpal bones (III and IV) in two dogs. The median ratio of bone screw diameter-to-metacarpal bone diameter was the same for dogs with metacarpal bone fractures and those with no fractures (44%), and the median angles of arthrodesis were 8 degrees and 7 degrees. These values were not statistically significant. The percentage length of the metacarpal bone covered by the plate was 53% (no fracture) compared with 46% (fracture), and this difference was statistically significant (P = .035). CONCLUSIONS: Screw diameter was not implicated as a predisposing factor for metacarpal bone fracture in dogs undergoing pancarpal arthrodesis using a dorsally applied dynamic compression plate. The length of the metacarpal bone covered by the bone plate did affect the frequency of metacarpal fracture, with fewer fractures occurring when greater than 53% of the bone length was covered by the dynamic compression plate. CLINICAL RELEVANCE: When performing pancarpal arthrodesis with a dorsally applied bone plate, it is recommended that at least 50% of the length of the third metacarpal bone should be covered by the plate.

Personality disorders and the five-factor model: a test of facet-level predictions.

We tested predicted relationships (Widiger, 1993; Widiger, Trull, Clarkin, Sanderson, & Costa, 1994) between personality disorder scores and facets of the five-factor model, and evaluated the relative benefits of facet-level analyses over domain-level analyses. Data from 614 undergraduates indicated: (a) 63% of the predicted facet relationships were significant, although many unpredicted relationships also emerged; (b) facet-level analyses did not yield substantially stronger effect sizes than domain-level analyses; but (c) facet-level analyses provided much better discrimination between personality disorders than domain-level analyses. Facets of the openness to experience domain also helped discriminate between personality disorders, which is in contrast to previous domain-level findings that openness is not important.

A test of models of personality disorder configuration.

In this study, the authors examined the degrees to which various models of personality disorder (PD) configuration are consistent with the primary data sets from clinical and community samples reported in the recent literature. Factor analyses were conducted on PD intercorrelation matrices, and the loading matrices were rotated to maximum possible fit with target matrices representing the PD configuration models. There was little support for the interpersonal circle or other circular orderings of PDs, or for T. Millon's (1990, 1996) biosocial learning theory. There was moderate support for the Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV; American Psychiatric Association, 1994) dimensions, for C. R. Cloninger's (1987) tridimensional theory, and for S. Torgersen and R. Alnaes's (1989) decision tree. There was consistent, stronger support for the 5-factor model (T. A. Widiger, T. J. Trull, J. F. Clarkin, C. Sanderson, & P. T. Costa, 1994) and for an empirically derived 7-factor model by C. R. Cloninger and D. M. Svrakic (1994).

Arthrodesis of the tarsometatarsal joint using a laterally applied plate in 10 dogs.

The efficacy of tarsometatarsal arthrodesis using a laterally applied plate was evaluated retrospectively in 10 dogs (11 joints). Arthrodesis was performed to manage a tarsometatarsal subluxation in two hocks; in the other cases, the tarsometatarsal subluxation was accompanied by tarsal or metatarsal fractures. The average period to referral was 15 days and all dogs had been managed with previous external coaptation of the affected limb. Arthrodesis was achieved in all the joints following initial surgery. Implant removal was indicated in three dogs which remained intermittently lame. Implants were left in situ in the remaining seven dogs. After an average follow-up period of 28 months, all dogs had resumed normal activity. Seven dogs were reported to be completely sound, one was stiff after rest following vigorous exercise and two had an intermittent mild lameness following strenuous exercise.

The big five factors of personality and their relationship to personality disorders.

Articles examining the relationship between the Big Five factors of personality and personality disorders (PDs) are reviewed. A survey of these studies indicates that there is some agreement regarding the relationship between the Big Five and PDs. However, the level of agreement varies and may be a function of instrumentation, the method of report, or how data have been analyzed. Future research should consider the role of peer-ratings, examine the relationship between PDs and the first-order factors of the Big Five, consider dimensions over and above the Big Five as predictors of PDs.

Repair of femoral trochanteric osteotomy in the dog.

The records and radiographs of 24 dogs that underwent femoral trochanteric osteotomy repair were reviewed. Osteotomy repair was performed with either a pin and tension band wire or a lag screw technique. Significant clinical complications associated with the osteotomy were identified in one dog (4 per cent) six weeks after surgery, although abnormal radiographic changes were evident in 15 dogs (62 per cent). The method of repair did not influence healing and there were comparable radiographic complication rates. It is concluded that femoral trochanteric osteotomy is not associated with significant clinical problems, despite a high incidence of abnormal radiographic findings.

Correlational structure of the MCMI-III personality disorder scales and comparisons with other data sets.

We examine the correlational structure of the personality disorder (PD) scales from the MCMI-III (Millon, 1994) among 614 college students. The correlation matrix from our nonclinical sample was highly similar to the clinical sample matrices reported by Millon (1994). Further analyses revealed that the correlation matrices from a variety of MCMI data sets are generally similar to one another, but are only moderately similar to PD correlation matrices based on other assessment techniques. PD correlation matrices based on different assessment techniques are generally not very similar to one another. Two-, 3-, and 4-factor solutions for the MCMI-III PD scales are reported and provide a framework for integrating apparently conflicting findings from previous work. The 4-factor solution was most meaningful and was consistent with the 5-factor model of PD.

Factor structure of the Beck Hopelessness Scale.

The factor structure of the Beck Hopelessness Scale (BHS; Beck & Steer, 1988) was examined among 411 outpatients (male = 132, female = 272, unknown = 7). Varimax-rotated principal-components analysis extracted three factors greater than unity that accounted for 40.4%, 6.9%, and 5.6% of the variance. Because the structure was invariant across factor rotations and levels of hopelessness severity, it is concluded that the BHS consists of three factors (Expectations of Success, Expectations of Failure, and Future Uncertainty).

Do trophectoderm and inner cell mass cells in the mouse blastocyst maintain discrete lineages?

The extent to which trophectoderm (TE) and inner cell mass (ICM) lineages in the mouse blastocyst remain distinct during the period from the commencement of cavitation up until 48 h later in culture was investigated. Fluorescent latex microparticles were used to label exclusively all TE cells in nascent blastocysts and the position of labelled progeny in cultured blastocysts was examined by disaggregation, by serial sectioning and by whole-mount analyses. The results indicate that, in most blastocysts (80-90%), TE and ICM lineages are entirely separate during this period while in the remainder lineage crossing is limited usually to only one or two cells of either tissue.