Indices for M-mode measurements in dogs usually have been based on the assumption that a linear relationship exists between these measurements and body weight (BW) or body surface area (BSA). The relationships between the geometry of 3-dimensional objects do not support this assumption. The purposes of this study were to retrospectively examine M-mode data from a large number of dogs of varying sizes and breeds that were examined by a large number of ultrasonographers, to use the allometric equation to determine the appropriate BW exponent required to predict these cardiac dimensions, and to determine normal mean values and prediction intervals for common M-mode variables. Linear regression analyses of data from 494 dogs (2.2-95 kg) revealed a good correlation between M-mode measurements and BW after logarithmic transformation of the data (r 2 .55-.88). Most variables were most closely related to an index of body length, BW 1/3 , although the exponent that best predicted diastolic and systolic left ventricular wall thicknesses was closer to 0.25. No variable indexed well to BW or BSA. With these data, appropriate mean values and prediction intervals were calculated for normal dogs, allowing veterinarians to correctly and appropriately index M-mode values. The equations developed from this study appear to be applicable to adult dogs of most breeds.

Indices for M-mode measurements in dogs usually have been based on the assumption that a linear relationship exists between these measurements and body weight (BW) or body surface area (BSA). The relationships between the geometry of 3-dimensional objects do not support this assumption. The purposes of this study were to retrospectively examine M-mode data from a large number of dogs of varying sizes and breeds that were examined by a large number of ultrasonographers, to use the allometric equation to determine the appropriate BW exponent required to predict these cardiac dimensions, and to determine normal mean values and prediction intervals for common M-mode variables. Linear regression analyses of data from 494 dogs (2.2-95 kg) revealed a good correlation between M-mode measurements and BW after logarithmic transformation of the data (r 2 ϭ .55-.88). Most variables were most closely related to an index of body length, BW 1/3 , although the exponent that best predicted diastolic and systolic left ventricular wall thicknesses was closer to 0.25. No variable indexed well to BW or BSA. With these data, appropriate mean values and prediction intervals were calculated for normal dogs, allowing veterinarians to correctly and appropriately index M-mode values. The equations developed from this study appear to be applicable to adult dogs of most breeds.Key words: Canine; Echocardiography; Heart; Reference range. M-mode echocardiography is commonly used to measure linear cardiac dimensions of cardiac chambers, walls, and great vessels. Because adult dogs range in weight from Ͻ2 to Ͼ90 kg, any definition of normal heart size must take into account the variation caused by differences in body size. Consequently, it is important to identify equations that accurately describe the relationships between body size and cardiac dimensions. Several authors have published equations, nomograms, or tables that are intended to be used as reference ranges for M-mode measurements for adult dogs of varying size and breed. [1][2][3][4][5][6][7][8][9][10][11] Critics have questioned the usefulness of some of these reference ranges because of small sample sizes, lack of data points for the extremes of body size, wide prediction intervals, and the use of inappropriate statistical methods. 5,[10][11][12][13][14][15] In addition, many authors have assumed that a linear relationship exists between linear cardiac dimensions and either body weight (BW) or body surface area (BSA), which might not be true. Evidence also has been presented suggesting that a general equation might never be accurate because breed is a factor Davis, CA 95616-8747; e-mail: cccornell@ucdavis.edu. Submitted March 7, 2003; Revised July 1 and October 31, 2003; Accepted December 11, 2003. Copyright that can cause M-mode measurements in dogs of the same weight to differ. 13The statistical methods used to produce the previously mentioned reference ranges were not described in every case, but in 2 studies in which the authors detailed their methods, reference ranges we...

Medial collateral ligament injury during primary total knee arthroplasty is a recognised complication potentially resulting in valgus instability, suboptimal patient outcomes and a higher rate of revision or reoperation. Options for management include primary repair with or without augmentation, reconstruction or immediate conversion to prosthesis with greater constraint, in conjunction with various postoperative rehabilitation protocols. Inconsistent recommendations throughout the orthopaedic literature have made the approach to managing this complication problematic. The objective of this study was to review the available literature to date comparing intraoperative and postoperative management options for primary total knee arthroplasty complicated by recognised injury to the medial collateral ligament. This systematic literature review was prospectively registered with PROSPERO (#CRD42014008866) and performed in accordance with PRISMA guidelines including a PRISMA flow diagram. Five articles satisfied the inclusion criteria. Each was a retrospective, observational cohort or case series with small numbers reported, inconsistent methodology and incompletely reported outcomes. Four of the five studies managing medial collateral ligament injury during total knee arthroplasty (47/84 patients) with direct repair with or without autograft augmentation reported good outcomes with no revision or reoperation required for symptomatic instability over a follow-up period of 16 months to almost 8 years. The fifth study with a follow-up to 10 years and a high rate of conversion to unlinked semi constrained total knee arthroplasty implant (30/37 patients) reported a greater incidence of revision due to instability, in patients in whom the medial collateral ligament injury was directly repaired without added constraint. Overall balance of evidence is in favour of satisfactory outcomes without symptomatic instability following direct repair with or without augmentation of an medial collateral ligament injury recognised intraoperatively during total knee arthroplasty. An implant with greater constraint may have reduced longevity in younger, more active patients through aseptic loosening. In elderly or less mobile patients, and in situations where the medial collateral ligament repair is deemed poor quality or incomplete, an implant with greater constraint would seem prudent. In patients where direct repair with or without augmentation was used, a period of 4-6 weeks of unrestricted rehabilitation in a hinged knee brace should be followed.

We describe four patients who were treated with primary total hip arthroplasty (THA) at two tertiary academic Australian teaching hospitals that experienced premature failure of head-neck trunnions through dissociation of the head-neck taper junction. This retrospective case series has similar clinical presentations and macroscopic pathology with severe head-neck taper junction loss of material, corrosion and early catastrophic failure. It is proposed that the accelerated wear is related to use of varus offset neck in a proprietary beta titanium alloy (Ti-12Mo-6Zr-2Fe or TMZF� Stryker Osteonics, Mahwah NJ, USA) TMZF femoral stem, longer head-neck combination in a relatively active, older, male patient population. In this limited case series presentation was on average 80 months (range 53-92) following index procedure. In three of the four patients, a prodromal period of groin or buttock pain was reported for between 1 week and 2 months prior to acute presentation. Significant metallosis and local tissue damage including gluteal muscle insufficiency was evident. Each stem revised was well fixed. An extended trochanteric osteotomy was required in two of the four cases for stem extraction. We recommend caution and further evaluation on the relationship between TMZF metal alloy and its longevity in higher demand patients with high neck offset, varus stem geometry and large CoCr bearing heads.