A systematic review of oncological outcomes after nipple-sparing mastectomy for breast cancer.

Nipple-sparing mastectomy is an alternative to skin-sparing mastectomy in select patients. Increasing evidence supports its use in the setting of breast cancer, however concerns still exist regarding oncological safety. The aim of this systematic review was to evaluate long-term oncological outcomes of patients who underwent nipple-sparing mastectomy for breast cancer. A systematic review of the literature was performed to evaluate oncological outcomes in patients with breast cancer who underwent nipple-sparing mastectomy. Five major databases (PubMed, Embase, Scopus, Web of Science and Cochrane) were searched. The review included all original articles published in English reporting long-term oncological outcomes. 2334 studies were identified. After applying inclusion and exclusion criteria, 17 retrospective studies involving 7107 patients were included. The indication for nipple-sparing mastectomy was invasive carcinoma in 6069 patients (85.4%) and in situ disease in 1038 (14.6%). Median follow up was 48 months (range 25-94). The weighted mean rates of local recurrence and recurrence involving the nipple-areola complex were 5.4% (0.9-11.9) and 1.3% (0-4.9), respectively. The weighted mean distant failure rate was 4.8% (1.5-23.0). Therapeutic nipple-sparing mastectomy is oncologically safe in select patients with breast cancer.

Double-loop cerclage resists greater loads for more cycles than twist and single-loop cerclage.

OBJECTIVE: To compare the mechanical performance of cerclage secured with twist, single-loop, and double-loop knots subjected to cyclic loading. STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Twist, single-loop and double-loop cerclage configurations of 1.0 mm wire. METHODS: The peak load resisted by each cerclage type was determined (n = 6). Cerclage were loaded cyclically to 80%, 60%, 40%, or 20% of its peak load (n = 8 per load level). The number of cycles until each cerclage loosened (residual tension <10 N) was recorded. RESULTS: All wires that failed did so by loosening. Twist cerclage cycled to 390 N and 290 N loosened within the first 10 cycles, and, when cycled to 100 N, they loosened by 250 cycles. All twist knots loosened by untwisting. Single-loop cerclage cycled to 320 N loosened within 10 cycles. At 240 N, 5 single-loop cerclage resisted 250 cycles before loosening. At 160 N, 2 of the 8 single-loop cerclage did not loosen by 100 000 cycles. When cycled to 640 N, one of the double-loop cerclage did not loosen following 500 000 cycles. When cycled to 480 N, 3 of the 8 wires did not loosen. CONCLUSION: Double-loop cerclage will be tighter and are better able to resist cycling than twist or single-loop cerclage. CLINICAL SIGNIFICANCE: Use of double-loop cerclage to stabilize bone fragments or prevent fissure propagation can be expected to provide greater resistance to loosening than twist or single-loop cerclage, both initially and with repeated loading.

Real-Time Feedback to Enhance the Teaching of Wire Tying.

Teaching the art of wire tying is difficult because the instructor is not able to gauge the effectiveness of the final product. The impact of an incorrect technique is usually not evident. Also, the instructor does not have a way to demonstrate the different levels of tension generated by different wire knotting techniques, nor their differing abilities to resist a load that a patient may apply. In this paper, a device is described that can provide real-time feedback on wire tension generated during knot tying, and how particular knots resist an applied distraction. This device has been used to deliver a live demonstration to reinforce lecture material, and in small group teaching exercises, where real-time feedback enhances skills and understanding. A stepwise training schedule for surgery residents structured as an entrustable professional activity is proposed.

Use of Top Hat Audience Response Software in a Third-Year Veterinary Medicine and Surgery Course.

Audience response devices are useful tools that can improve student engagement and learning during instructional sessions. The purpose of this article is to describe our experience with a new cloud-based application known as Top Hat, which includes audience response tools in its application suite. The software was used in a multi-specialty, multi-instructor medicine and surgery course in the third year of a veterinary curriculum. In addition to standard multiple-choice and short-answer questions, Top Hat has several unique question types and methods of displaying the responses given. These include displaying free-text responses in a word cloud format and a "click-on-target" question type that allows students to indicate their response by clicking on a location within an image. Responses for this latter question type are displayed in a heat map format. A discussion tool is also available, which allows students to respond, read other students' responses in real time, and then reply again if warranted. This feature also supports drawing-based responses. The variety of question types was very useful in keeping students engaged during teaching sessions, giving this application several advantages over systems that are limited to multiple-choice questions only. In addition, the application allowed rapid identification of areas of student knowledge and misunderstandings, which facilitated the direction of further discussion and clarification of important learning issues.

Influence of wire configuration on resistance to fragment distraction of tension bands placed in a greater trochanteric osteotomy model.

OBJECTIVE: To determine the influence of wiring configurations on initial tension and resistance to tensile loads in tension band constructs without the contributions of Kirschner-wire stabilization. STUDY DESIGN: Experimental study. SAMPLE POPULATION: A solid brass femur model manufactured on the basis of computed tomography of a normal right femur of a 30-kg dog modified by transection of the greater trochanter and placement of two pins that did not cross the simulated osteotomy. METHODS: Four tension band configurations were applied to the metal trochanteric osteotomy model: figure-of-eight with one twist (OT), figure-of-eight with two twists (TT), dual interlocking single loop, and double loop (DL). Configurations were tested under both monotonic loading (n = 8 per configuration) and incremental cyclic loading (n = 8 per configuration). Initial tension after tying, residual tension remaining after each cycle, and failure load at 2 mm of displacement (considered equivalent to clinical failure) were compared between configurations. RESULTS: The initial tension and the load to 2 mm of displacement were lower for OT wires compared with TT wires. The DL was the strongest and most stable configuration, generating 2.3 to 3.5 times greater initial tension, maintaining a greater percentage of residual tension under incremental cyclic loads, and resisting 2.0 to 2.4 times greater load before failure at 2 mm. Failure load was highly correlated with initial tension. CONCLUSION: Wire configurations reaching greater initial tension, such as the DL, allowed constructs to resist higher tensile loads. CLINICAL IMPACT: Wire configurations allowing higher initial tension may be warranted when tension bands are expected to sustain high tensile loads.

Tibial Plateau Leveling Osteotomy Plate Contouring and Proximal Load Screw Angulation Affect Osteotomy Compression.

OBJECTIVE: To evaluate the effect of contouring a tibial plateau leveling osteotomy (TPLO) plate, the associated angulation of the dynamic compression plate (DCP) hole relative to the long axis of the tibia, and angulation of the screw relative to the DCP hole on the osteotomy compression generated by load screws in a TPLO model. STUDY DESIGN: In vitro biomechanical study. STUDY POPULATION: Polyoxymethylene (POM) rod and synthetic cortical bone substitute model (n = 9). METHODS: The distal portion of a Slocum TPLO plate was attached to a horizontally positioned POM rod that was connected to a load cell. A segment of synthetic cortical bone substitute was attached to the end mount of the testing frame and adjusted to conform to the angle of the proximal portion of the TPLO plate. A 3.5 mm cortical bone screw was inserted in the proximal DCP hole and tightened to 1.5 Nm. The peak longitudinal load (N) was recorded. Screw insertion and data collection were repeated for proximal plate angles of 0-40° at 5° increments. RESULTS: A significant increase in the compression generated was observed as the plate angle was increased from 0° to 10°. The compression ceased to significantly increase until the plate was bent more than 20°, after which a significant decrease in compression was noted. A marked reduction in the compression generated occurred at plate angles greater than 30°. CONCLUSION: Angulation of the DCP hole and screw insertion angle can have deleterious effects on the magnitude of osteotomy compression.

Relationship between mechanical thresholds and limb use in dogs with coxofemoral joint oa-associated pain and the modulating effects of pain alleviation from total hip replacement on mechanical thresholds.

OBJECTIVES: To compare von Frey mechanical quantitative sensory thresholds (mQSTvF ) between pelvic limbs in dogs before unilateral total hip replacement (THR) surgery; to correlate ground reaction forces (GRF) with mQSTvF ; to assess changes in mQSTvF after THR surgery. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n = 44). METHODS: mQSTvF and GRF measured using a pressure sensitive walkway were evaluated before, and 3, 6, and 12 months after, unilateral THR. Measurements were recorded from the affected (operated) pelvic limb (APL) and the non-operated pelvic limb (NPL). Random effects analysis and forwards stepwise linear regression models were used to evaluate the influence of time since surgery and patient factors on mQSTvF thresholds. RESULTS: There were no significant correlations between mQSTvF data and age, bodyweight or the GRF variables. Preoperative mQSTvF measured at the APL and NPL did not differ (P = .909). mQSTvF thresholds increased significantly after 12 months in NPL (P = .047) and APL (P = .001). In addition to time, APL mQSTvF values were significantly affected by sex (higher in males, P = .010) and body condition score (higher in leaner dogs, P = .035) and NPL mQSTvF values by sex (P = .038). CONCLUSION: Successful unilateral THR results in decreased central sensitization after 12 months.

Biomechanical evaluation of the influence of an intramedullary pin on the stability of a feline ilial fracture model stabilized with a bone plate.

OBJECTIVE: To compare the mechanical properties of feline ilial fractures stabilized with either a plate (P), or a plate and IM pin (P + P). STUDY DESIGN: Mechanical study. SAMPLE POPULATION: Cadaveric cat pelvii (n = 10). METHODS: Feline ilial fractures (n = 20) stabilized with either P or P + P were subjected to 100 nondestructive load cycles, then loaded to failure. Deformation after cycling, yield load and displacement, stiffness and load at 2 mm of displacement were compared between groups. RESULTS: There were no significant differences between groups for any of the parameters. Variability of data was much larger for the P + P group. CONCLUSIONS: No biomechanical advantage was demonstrated. The P + P constructs were not significantly stronger than plates alone in this acutely loaded cadaveric model.

Prevalence of radiographic appendicular osteoarthritis and associated clinical signs in young dogs.

This study aimed to determine the prevalence of osteoarthritis (OA) and associated clinical signs in young dogs. Owners of dogs aged 8 months-4 years from a single practice, were contacted in random order, to participate in a general health screen. Clinical and orthopedic examinations were performed. Each joint was scored for pain reactions (0-4). Orthogonal radiographs of all joints were made under sedation. Each joint was scored for radiographic OA (rOA) severity on an 11-point scale. Clinical OA (cOA) was defined as an overlap of rOA and joint pain in ≥ 1 joint. Owners completed OA questionnaires. The owners of 123 dogs agreed to participate. Overall, 39.8% (49/123) of dogs had rOA in ≥ 1 joint, and 16.3% (20/123) or 23.6% (29/123) dogs had cOA, depending on the cut-off value of joint pain; moderate (2), or mild (1), respectively. Owners of dogs with cOA observed signs of impairment in approximately 30% of cases. Only 2 dogs with cOA were receiving OA pain management. The most commonly affected joints in descending order of frequency were elbow, hip, tarsus, and stifle. Radiographically visible OA is common in young dogs, and 40-60% of dogs with rOA had cOA. However, OA-pain appears underdiagnosed and undertreated in young dogs.

Resistance to subsidence of an uncemented femoral stem after cerclage wiring of a fissure.

OBJECTIVE: To compare: (1) the force required to initiate subsidence, and (2) the relative subsidence, of femoral stems implanted into intact femora, and then into the same femora in which an induced fissure had been stabilized by cerclage. STUDY DESIGN: In vitro, mechanical study. SAMPLE POPULATION: Femora (n=9) from 9 dogs. METHODS: Femora were prepared for implantation of an uncemented stem. Stems were implanted with continuous and impact loading. After axial loading until a fissure occurred, the stems were extracted, and the fissure stabilized with double-loop cerclage. Stems were reimplanted, and reloaded to failure. RESULTS: Mean±SD load to initiate subsidence in intact femora was 1706±584 N compared with 2379±657 N for cerclaged bones (P=.002). Mean relative subsidence of intact femora was 3.99±2.09 mm compared with 1.79±2.99 mm for cerclaged bones (P=.091). CONCLUSIONS: The load to initiate subsidence is increased in femora that have fissured, then have been stabilized with double-loop cerclage, when compared with intact femora. The relative subsidence is not different between intact and stabilized specimens.

Comparison of body weight distribution, peak vertical force, and vertical impulse as measures of hip joint pain and efficacy of total hip replacement.

OBJECTIVE: To determine whether there is a difference between the ability of peak vertical force (PVF), vertical impulse (VI), and percentage body weight distribution (%BW(dist) ) in differentiating which leg is most affected by hip joint pain before total hip replacement (THR) surgery, and for measuring changes in limb use after THR surgery. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n = 47). METHODS: Ground reaction force (GRF) data were collected using a pressure-sensitive walkway the day before THR surgery and at ∼3, 6, and 12 months postoperatively. PVF and VI expressed as a percentage of body weight (%PVF, %VI), and %BW(dist) were recorded. Regression models performed separately for each outcome were used for statistical analysis. RESULTS: When comparing limb use between the affected limb (AP) and the nonaffected limb (NP) preoperatively, differences between limbs were statistically significant when evaluated using PVF (P = .023), VI (P = .010), and %BW(dist) (P = .012). When evaluating the magnitude of absolute and percentage change difference in AP limb use preoperatively versus postoperatively, differences were statistically significant when evaluated using PVF (P < .001 and P = .001, respectively), VI (P = .001 and P < .001) and %BW(dist) (P < .001 and P < .001). CONCLUSION: There appeared to be no difference in the sensitivity of VI, PVF, and %BW(dist) for evaluating limb use before and after THR.

Evolution of coronary artery calcification in patients with chronic kidney disease Stages 3 and 4, with and without diabetes.

BACKGROUND: The purpose of this study was to report the evolution of coronary artery calcification (CAC) in subjects with chronic kidney disease Stages 3 and 4 comparing those with and without diabetes. We previously reported prevalence in the same population. METHODS: CAC was measured using multi-slice computer tomography. We prospectively followed up 103 patients for 2 years, 49 with diabetes and 54 without diabetes. Demographic, routine biochemistry, calcification inhibitors and bone mineral density data were collected and analysed. Evolution of CAC was defined as those with a difference of ≥ 2.5 U between baseline and final square root CAC scores. RESULTS: There were more progressors in the group with diabetes, 24 compared to 12 in the group without diabetes (P= 0.004). When diabetes was present, CAC progressed equally in men and women. Risk factors for evolution of CAC included age, baseline CAC score and serum phosphate levels. Baseline CAC score, phosphate and body mass index were independent predictors for the increase of CAC score during the study period. Severity of CAC was greater in the diabetes group (median CAC score at baseline in the group with diabetes 154 increased to 258 2 years later, P < 0.001). CONCLUSIONS: Evolution of CAC is greater in older patients and those with diabetes, where the gender advantage of being female is lost. Serum phosphate level, despite being within the normal range and virtually no use of phosphate binders, was also a risk factor. Further studies are required to determine the levels of serum phosphate required to minimize cardiovascular risk.

Defining the rate of, and factors influencing, radiographic progression of osteoarthritis of the canine hip joint.

BACKGROUND: This study aimed to define the rate of progression of radiographic osteoarthritis (OA) of the canine hip joint and to describe factors affecting this progression. METHODS: Dogs that underwent unilateral total hip replacement (THR) were reviewed for the evaluation of radiographic appearance of the non-operated hip joint over time. Standard extended ventrodorsal hip radiographs were taken preoperatively and postoperatively. All images were anonymized, randomized and scored using three different methods. The mean daily change between evaluations was calculated in each individual dog, and the effect of sex, age, body weight, open/closed status of the proximal femoral physis, preoperative severity of OA, time after surgery and their interactions, were investigated as potential influencing factors. RESULTS: After reviewing the medical records, 163 dogs (468 images) met the inclusion criteria. Consistent across the three scoring systems, radiographic progression of OA was greater in younger (open physis) and spayed female dogs. A subset of seven patients (4.3%) had a faster progression of OA and was considered outliers. No dog was rated as outlier by all three scoring systems. CONCLUSION: The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

In vitro evaluation of a low-modulus mesh canine prosthetic hip stem.

OBJECTIVE: To compare an electron beam melting-processed (EBMP) low-modulus titanium alloy mesh stem with a commercial cobalt-chromium (CC) stem in a canine cadaver model. SAMPLE POPULATION: 9 pairs of cadaver femora. PROCEDURES: EBMP stems of 3 sizes were placed in randomly chosen sides of femora (left or right) and CC stems in opposite sides. Stem impaction distances were recorded. Five strain gauges were attached to the femoral surface to record transverse tensile (hoop) strains in the femur during axial loading. Constructs were axially loaded 4 times to 800 N and 4 times to 1,600 N in a materials testing machine. Axial stiffness of constructs and bone surface strains were compared between EBMP and CC constructs. RESULTS: Stems were impacted without creating femoral fissures or fractures. Stem impaction distances were larger for EBMP stems than for CC stems. Mean axial stiffness of EBMP constructs was lower than mean axial stiffness of CC constructs. Subsidence did not differ between groups. Bone strains varied among strain gauge positions and were largest at the distal aspect of the stems. At a load of 1,600 N, bones strains were higher in CC constructs than in EBMP constructs for 2 of 4 medial strain gauges. CONCLUSIONS AND CLINICAL RELEVANCE: EBMP stems were successfully impacted and stable and led to a focal decrease in bone strain; this may represent an acceptable option for conventional or custom joint replacement.

Item generation and design testing of a questionnaire to assess degenerative joint disease-associated pain in cats.

OBJECTIVE: To determine the items (question topics) for a subjective instrument to assess degenerative joint disease (DJD)-associated chronic pain in cats and determine the instrument design most appropriate for use by cat owners. ANIMALS: 100 randomly selected client-owned cats from 6 months to 20 years old. PROCEDURES: Cats were evaluated to determine degree of radiographic DJD and signs of pain throughout the skeletal system. Two groups were identified: high DJD pain and low DJD pain. Owner-answered questions about activity and signs of pain were compared between the 2 groups to define items relating to chronic DJD pain. Interviews with 45 cat owners were performed to generate items. Fifty-three cat owners who had not been involved in any other part of the study, 19 veterinarians, and 2 statisticians assessed 6 preliminary instrument designs. RESULTS: 22 cats were selected for each group; 19 important items were identified, resulting in 12 potential items for the instrument; and 3 additional items were identified from owner interviews. Owners and veterinarians selected a 5-point descriptive instrument design over 11-point or visual analogue scale formats. CONCLUSIONS AND CLINICAL RELEVANCE: Behaviors relating to activity were substantially different between healthy cats and cats with signs of DJD-associated pain. Fifteen items were identified as being potentially useful, and the preferred instrument design was identified. This information could be used to construct an owner-based questionnaire to assess feline DJD-associated pain. Once validated, such a questionnaire would assist in evaluating potential analgesic treatments for these patients.

Evaluation of a midhumeral block of the radial, ulnar, musculocutaneous and median (RUMM block) nerves for analgesia of the distal aspect of the thoracic limb in dogs.

OBJECTIVE: To evaluate a technique for midhumeral peripheral nerve blockade in the dog. STUDY DESIGN: Cadaveric technique development; in vivo placebo-controlled, prospective crossover study. ANIMALS: Canine cadavers (n=38) and 8 clinically healthy, adult hound dogs. METHODS: A technique for peripheral block of the radial, ulnar, musculocutaneous, and median nerves (RUMM block) was evaluated using cadaver limbs. Eight purpose-bred, research dogs were anesthetized; a RUMM block was performed on each thoracic limb. One limb from each dog randomly received 0.5% bupivacaine and the opposite limb was assigned to receive sterile saline solution as a control. After recovery from anesthesia, skin sensation at selected dermatomes was evaluated for 24 hours using a mechanical stimulus. Weight-bearing, conscious proprioception, and withdrawal reflex were also evaluated. One month after initial testing, each dog was reanesthetized and each limb received the opposite treatment. RESULTS: Sensory thresholds were significantly increased over baseline measurements when compared with control limbs for all nerves. Complete sensory block was achieved in radial (15/16), ulnar (3/16), musculocutaneous (8/16), and median (11/16) nerves, using a mechanical stimulus of analgesia. Complete simultaneous block of all nerves was only obtained in 1 of 16 limbs. CONCLUSION: RUMM block resulted in desensitization of the skin in the associated dermatomes for 4-10 hours. Complete sensory block of the dermatomes supplied by the radial nerve was most consistent. CLINICAL RELEVANCE: RUMM block may be an effective technique to provide adjunctive analgesia for dogs undergoing surgery of the distal aspect of the thoracic limb.