Perceptions of Competition-Based Learning After a Brief Experience at a National Surgical Meeting.

BACKGROUND: Competition-based learning (CBL) facilitates learning through competitions. At the 2022 & 2023 Annual SAGES meetings, we evaluated a CBL experience (TOP GUN Shootout) developed from a modified version of the previously validated TOP GUN Laparoscopic Skills and Suturing Program. The project sought to evaluate the TOP GUN Shootout's (TGS) ability to enhance participant engagement in pursuit of laparoscopic surgical skills. METHODS: Participants competed in the TGS. Their scores (time and errors) were recorded for: Fundamentals of Laparoscopic Surgery Peg Pass, Cup Drop Task, and Intracorporeal Suturing. All participants completed a 10-question satisfaction survey on a 7-point Likert scale, with questions assessing 3 domains: (1) capability/confidence in MIS skill performance prior to the competition; (2) applicability and satisfaction with TGS's capacity to develop MIS skills; and (3) interest in seeking additional MIS training and appropriateness of CBL in MIS training. Descriptive statistics were used to evaluate these areas. RESULTS: Overall, 121 participants completed the TGS, of whom 84 (69%) completed the satisfaction survey. The average age was 32.9 years, 67% were males. On average (+/- SD), participant satisfaction was 5.04 (+/- 2.08) for Domain 1, 6.20 (+/- 1.28) for Domain 2, and 6.58 (+/- .95) for Domain 3. CONCLUSION: Participants described an overall lack of confidence in their MIS skills prior to the 2022-2023 Annual SAGES conference. Participants felt that this brief CBL experience, aided in the development of their MIS skills. Furthermore, this brief CBL experience may inspire learners to seek out further training of their MIS skills.

Effects of potato resistant starch intake on insulin sensitivity, related metabolic markers and appetite ratings in men and women at risk for type 2 diabetes: a pilot cross-over randomised controlled trial.

BACKGROUND: The intake of certain types of resistant starch (RS) has been associated in some studies with increased whole-body insulin sensitivity. This randomised, cross-over pilot trial evaluated the effect of consuming cooked, then chilled potatoes, a source of RS, compared to isoenergetic, carbohydrate (CHO)-containing control foods, on insulin sensitivity and related markers. METHODS: Nineteen adults with body mass index 27.0-39.9 kg m-2 consumed 300 g day-1 RS-enriched potatoes (approximately two potatoes; ~18 g RS) or CHO-based control foods, as part of lunch, evening and snack meals, over a 24-h period. After an overnight fast, insulin sensitivity, CHO metabolism markers, free fatty acids, breath hydrogen levels and appetite were assessed for up to 5 h after the intake of a standard breakfast. The primary endpoint was insulin sensitivity, assessed with the Matsuda index. P < 0.05 (one-sided) was considered statistically significant. RESULTS: Insulin sensitivity was not significantly different between the potato and control conditions. The potato intervention resulted in higher postprandial breath hydrogen (P = 0.037), lower postprandial free fatty acid concentrations (P = 0.039) and lower fasting plasma glucose (P = 0.043) compared to the control condition. Fullness ratings were significantly lower after potato versus control (P = 0.002). No other significant effects were observed; however, there was a trend toward lower fasting insulin (P = 0.077) in the potato versus the control condition. CONCLUSIONS: The results of this pilot study suggest RS-enriched potatoes may have a favourable impact on carbohydrate metabolism and support the view that additional research in a larger study sample is warranted.

Isolation, characterization and molecular identification of a novel aquareovirus that infects endangered fountain darter Etheostoma fonticola.

The fountain darter Etheostoma fonticola (FOD) is a federally endangered fish listed under the US Endangered Species Act. Here, we identified and characterized a novel aquareovirus isolated from wild fountain darters inhabiting the San Marcos River. This virus was propagated in Chinook salmon embryo (CHSE)-214, rainbow trout gonad-2 and fathead minnow cells at 15°C. The epithelioma papulosum cyprini cell line was refractory at all temperatures evaluated. High throughput sequencing technologies facilitated the complete genome sequencing of this virus utilizing ribosomal RNA-depleted RNA extracted from infected CHSE-214 cells. Conventional PCR primer sets were developed for the detection and confirmation of this virus to assist diagnostic screening methods. Phylogenetic analysis suggests this virus belongs to the Aquareovirus A genus. This research provides requisite initial data critical to support hatchery and refugia biosecurity measures for this endangered species.

Kinematic parameters contributing to the production of spin in elite finger spin bowling.

The aim of this study was to identify the key kinematic parameters which contribute to higher spin rates in elite finger spin bowling. Kinematic data were collected for twenty-three elite male finger spin bowlers with thirty kinematic parameters calculated for each delivery. Stepwise linear regression and Pearson product moment correlations were used to identify kinematic parameters linked to spin rate. Pelvis orientation at front foot contact (r = 0.674, p < 0.001) and ball release (r = 0.676, p < 0.001) were found to be the biggest predictors of spin rate, with both individually predicting 43% of the observed variance in spin rate. Other kinematic parameters correlated with spin rate included: shoulder orientation at ball release (r = 0.462, p = 0.027), and pelvis-shoulder separation angle at front foot contact (r = 0.521, p = 0.011). The bowlers with the highest spin rates adopted a mid-way pelvis orientation angle, a larger pelvis-shoulder separation angle and a shoulder orientation short of side-on at front foot contact. The segments then rotated sequentially, starting with the pelvis and finishing with the pronation of the forearm. This knowledge can be translated to coaches to provide a better understanding of finger spin bowling technique.

Relationship between drug burden and physical and cognitive functions in a sample of nursing home patients with dementia.

PURPOSE: The Drug Burden Index (DBI) is a tool to quantify the anticholinergic and sedative load of drugs. Establishing functional correlates of the DBI could optimize drug prescribing in patients with dementia. In this cross-sectional study, we determined the relationship between DBI and cognitive and physical functions in a sample of patients with dementia. METHODS: Using performance-based tests, we measured physical and cognitive functions in 140 nursing home patients aged over 70 with all-cause dementia. We also determined anticholinergic DBI (AChDBI) and sedative DBI (SDBI) separately and in combination as total drug burden (TDB). RESULTS: Nearly one half of patients (48%) used at least one DBI-contributing drug. In 33% of the patients, drug burden was moderate (0 < TDB < 1) whereas in 15%, drug burden was high (TDB ≥ 1). Multivariate models yielded no associations between TDB, AChDBI, and SDBI, and physical or cognitive function (all p > 0.05). CONCLUSIONS: A lack of association between drug burden and physical or cognitive function in this sample of patients with dementia could imply that drug prescribing is more optimal for patients with dementia compared with healthy older populations. However, such an interpretation of the data warrants scrutiny as several dementia-related factors may confound the results of the study.

Surgical Pulmonary Embolectomy: Experience in a Series of 37 Consecutive Cases.

BACKGROUND: Massive pulmonary embolism is a poorly tolerated condition. Treatment options in this condition include anticoagulation and primary reperfusion therapy - systemic thrombolysis, catheter based treatments or surgical embolectomy. There is little data on the relative efficacy of each treatment. METHODS: The preoperative characteristics and outcomes of patients referred for surgical embolectomy between 2000-2014 was reviewed. Echocardiography was performed in the majority of patients before and after surgery. RESULTS: Thirty-seven patients underwent pulmonary embolectomy between 2000-2014. One patient died within 30 days, another before leaving hospital. All other patients were alive at the time of follow-up (survival 94.6% at median 36 months). Median ventilation time was 24hours. Median hospital length of stay was 10.5 days. There was echocardiographic evidence of severe right ventricular strain (increased size and decreased function) before surgery, which was significantly improved to within the normal range by discharge, and follow-up. CONCLUSIONS: Surgical embolectomy is a safe procedure, with low mortality, improved postoperative right ventricular function and pulmonary pressure, and good long-term outcome. Early relief of a large proportion of the clot burden can be life-saving. There should be consideration for its use as an initial treatment strategy in patients with massive or submassive pulmonary embolus with a large burden of proximal clot. A multidisciplinary approach for the treatment of these patients is required.

shRNA-induced saturation of the microRNA pathway in the rat brain.

RNA interference (RNAi) is a powerful strategy for unraveling gene function and for drug target validation, but exogenous expression of short hairpin RNAs (shRNAs) has been associated with severe side effects. These may be caused by saturation of the microRNA pathway. This study shows degenerative changes in cell morphology and intrusion of blood vessels after transduction of the ventromedial hypothalamus (VMH) of rats with a shRNA expressing adeno-associated viral (AAV) vector. To investigate whether saturation of the microRNA pathway has a role in the observed side effects, expression of neuronal microRNA miR-124 was used as a marker. Neurons transduced with the AAV vector carrying the shRNA displayed a decrease in miR-124 expression. The decreased expression was unrelated to shRNA sequence or target and observed as early as 1 week after injection. In conclusion, this study shows that the tissue response after AAV-directed expression of a shRNA to the VMH is likely to be caused by shRNA-induced saturation of the microRNA pathway. We recommend controlling for miR-124 expression when using RNAi as a tool for studying (loss of) gene function in the brain as phenotypic effects caused by saturation of the RNAi pathway might mask true effects of specific downregulation of the shRNA target.

Functional status after lung transplantation in older adults in the post-allocation score era.

This manuscript describes the functional status trajectory of older (age 65 or older) and younger (age 18-64) adults after lung transplantation (LT). After the implementation of the lung allocation score (LAS) in 2005, older adults became the fastest growing subgroup of recipients. Yet the impact of LT on physical function, a main determinant of quality of life in older adults, is unknown. We conducted a retrospective cohort study using United Network for Organ Sharing data on 4805 adults who received a LT during 2005-2009. We divided them into older (≥65; n = 774) and younger (18-64; n = 4031) cohorts. Functional status was measured by Karnofsky performance score (KPS). Mixed models estimated the impact of age group on the rate of functional decline starting at 1 year posttransplantation. We controlled for KPS at transplantation, gender, race, diagnosis, LAS and LT type. Age group was not associated with different rates of decline in KPS over time. On average, recipients who were older, received a single LT, or had a low KPS at transplantation had worse functional status posttransplantation when compared to their counterparts, but rarely reached disability at 48 months. Overall, LT had a positive and durable effect on physical function for both older and younger recipients.

Blood mRNA biomarkers for detection of treatment response in acute pulmonary exacerbations of cystic fibrosis.

BACKGROUND: Acute pulmonary exacerbations accelerate pulmonary decline in cystic fibrosis (CF). There is a critical need for better predictors of treatment response. OBJECTIVE: To test whether expression of a panel of leucocyte genes directly measured from whole blood predicts reductions in sputum bacterial density. METHODS: A previously validated 10-gene peripheral blood mononuclear cell (PBMC) signature was prospectively tested in PBMC and whole blood leucocyte RNA isolated from adult subjects with CF at the beginning and end of treatment for an acute pulmonary exacerbation. Gene expression was simultaneously quantified from PBMCs and whole blood RNA using real-time PCR amplification. Test characteristics including sensitivity, specificity, positive and negative predictive values were calculated and receiver operating characteristic curves determined the best cut-off to diagnose a microbiological response. The findings were then validated in a smaller independent sample. RESULTS: Whole blood transcript measurements are more accurate than forced expiratory volume in 1 s (FEV(1)) or C reactive protein (CRP) alone in identifying reduction of airway infection. When added to FEV(1), the whole blood gene panel improved diagnostic accuracy from 64% to 82%. The specificity of the test to detect reduced infection was 88% and the positive predictive value for the presence of persistent infection was 86%. The area under the curve for detecting treatment response was 0.81. Six genes were the most significant predictors for identifying reduction in airway bacterial load beyond FEV(1) or CRP alone. The high specificity of the test was replicated in the validation cohort. CONCLUSIONS: The addition of blood leucocyte gene expression to FEV(1) and CRP enhances specificity in predicting reduced pulmonary infection and may bolster the assessment of CF treatment outcomes.

Recent advances in the management of transient ischaemic attack: a clinical review.

Transient ischaemic attack (TIA) if untreated carries a high risk of early stroke and is associated with poorer long-term survival. There have been recent advances in the understanding of TIA, its investigations, management and organisation of services for patient care. Clinically, patients are diagnosed TIA if they have transient sudden-onset focal neurological symptoms which usually completely and rapidly resolve by presentation. Patients with residual symptoms should be evaluated as potentially having stroke, if they present within 4.5 h of onset, should be urgently evaluated for their potential eligibility for thrombolysis. TIA patients should receive rapid attention with essential investigations, including brain imaging, electrocardiograph and carotid ultrasound. Immediate administration of an antiplatelet agent is recommended after brain imaging, with subsequent attention to preventing or treating other mechanistic factors. There is emerging evidence that TIA patients can be managed safely in the outpatient setting after initial rapid management in emergency departments as part of a structured clinical pathway supervised by stroke specialists. Clinical systems of management may require approaches individualised to the healthcare setting, while adopting the central aspects of rapid management.

Screening and pathways to maternal mental health care in a South African antenatal setting.

In low-resource settings, a stepped care approach is necessary to screen and provide care for pregnant women with mental health problems. This study sought to identify screening items that were most robust at differentiating women experiencing psychological distress and requiring counselling [assessed by screening with the Edinburgh Postnatal Depression Scale (EPDS) and a Risk Factor Assessment (RFA)] from those with a psychiatric disorder as diagnosed by a psychiatrist. Case records of women in an antenatal mental health service in Cape Town were reviewed. Composite scores and individual items on screening scales (EPDS, RFA) of participants who qualified for counselling (n = 308) were compared to those of participants who were diagnosed with a psychiatric disorder (n = 58). All participants with a psychiatric disorder were diagnosed with either depression or anxiety disorders. These participants had higher mean scores on the EPDS and RFA than those who qualified for counselling (p < 0.01). Logistic regression and ROC analyses suggested that the best items to distinguish women with depression or anxiety from those qualifying for counselling were 'I have felt sad and miserable', 'I am not pleased about being pregnant' and 'I have had serious depression, panic attacks or problems with anxiety before' (sensitivity 0.655, specificity 0.750 for this combination of three items). A small number of items may be useful in screening for mental illness in pregnancy which requires higher levels of care. Such screening may contribute to a more efficient stepped care approach.

Obesity and impaired prohormone processing associated with mutations in the human prohormone convertase 1 gene.

Human obesity has an inherited component, but in contrast to rodent obesity, precise genetic defects have yet to be defined. A mutation of carboxypeptidase E (CPE), an enzyme active in the processing and sorting of prohormones, causes obesity in the fat/fat mouse. We have previously described a women with extreme childhood obesity (Fig. 1), abnormal glucose homeostasis, hypogonadotrophic hypogonadism, hypocortisolism and elevated plasma proinsulin and pro-opiomelanocortin (POMC) concentrations but a very low insulin level, suggestive of a defective prohormone processing by the endopeptidase, prohormone convertase 1 (PC1; ref. 4). We now report this proband to be a compound heterozygote for mutations in PC1. Gly-->Arg483 prevents processing of proPC1 and leads to its retention in the endoplasmic reticulum (ER). A-->C+4 of the intro-5 donor splice site causes skipping of exon 5 leading to loss of 26 residues, a frameshift and creation of a premature stop codon within the catalytic domain. PC1 acts proximally to CPE in the pathway of post-translational processing of prohormones and neuropeptides. In view of the similarity between the proband and the fat/fat mouse phenotype, we infer that molecular defects in prohormone conversion may represent a generic mechanism for obesity, common to humans and rodents.

Activation of LIM-kinase by Pak1 couples Rac/Cdc42 GTPase signalling to actin cytoskeletal dynamics.

Extracellular signals regulate actin dynamics through small GTPases of the Rho/Rac/Cdc42 (p21) family. Here we show that p21-activated kinase (Pak1) phosphorylates LIM-kinase at threonine residue 508 within LIM-kinase's activation loop, and increases LIM-kinase-mediated phosphorylation of the actin-regulatory protein cofilin tenfold in vitro. In vivo, activated Rac or Cdc42 increases association of Pak1 with LIM-kinase; this association requires structural determinants in both the amino-terminal regulatory and the carboxy-terminal catalytic domains of Pak1. A catalytically inactive LIM-kinase interferes with Rac-, Cdc42- and Pak1-dependent cytoskeletal changes. A Pak1-specific inhibitor, corresponding to the Pak1 autoinhibitory domain, blocks LIM-kinase-induced cytoskeletal changes. Activated GTPases can thus regulate actin depolymerization through Pak1 and LIM-kinase.

Increased expression of blood mononuclear cell nitric oxide synthase type 2 in rheumatoid arthritis patients.

Nitric oxide (NO) is an important inflammatory mediator in nonhuman animal models of rheumatoid arthritis (RA). The purpose of the present study was to determine whether blood mononuclear cells from patients with active RA (as compared to control subjects) have higher levels of NO synthase type 2 (NOS2) and produce more NO in vitro. Leukocytes from 25 RA patients and 20 normal subjects were examined. Arthritis activity was assessed by tender and swollen joint counts, duration of morning stiffness, patient assessment of pain, physician and patient global assessment of disease activity, the modified Stanford Health Assessment Questionnaire, and by blood levels of acute phase reactants. Blood mononuclear cell NOS enzyme activity/antigen content and nitrite/nitrate formation in vitro were measured. Blood mononuclear cells from RA patients had increased NOS activity and increased NOS2 antigen content as compared to those from normal subjects, and responded to interferon-gamma with increased NOS expression and nitrite/nitrate production in vitro. NOS activity of freshly isolated blood mononuclear cells correlated significantly with disease activity, as assessed by render and swollen joint counts. Our results demonstrate that patients with RA have systemic activation for NOS2 expression, and that the degree of activation correlates with disease activity. Increased NOS2 expression and NO generation may be important in the pathogenesis of RA.

Mitochondrial DNA damage as a potential biomarker of LRRK2 kinase activity in LRRK2 Parkinson's disease.

Leucine-rich repeat kinase 2 (LRRK2) is a promising therapeutic target for the treatment of Parkinson's disease (PD) and LRRK2 kinase inhibitors are currently being tested in early phase clinical trials. In order to ensure the highest chance of success, a biomarker-guided entry into clinical trials is key. LRRK2 phosphorylation, and phosphorylation of the LRRK2 substrate Rab10, have been proposed as target engagement biomarkers for LRRK2 kinase inhibition. However, a pharmacodynamic biomarker to demonstrate that a biological response has occurred is lacking. We previously discovered that the LRRK2 G2019S mutation causes mitochondrial DNA (mtDNA) damage and is LRRK2 kinase activity-dependent. Here, we have explored the possibility that measurement of mtDNA damage is a "surrogate" for LRRK2 kinase activity and consequently of kinase inhibitor activity. Mitochondrial DNA damage was robustly increased in PD patient-derived immune cells with LRRK2 G2019S mutations as compared with controls. Following treatment with multiple classes of LRRK2 kinase inhibitors, a full reversal of mtDNA damage to healthy control levels was observed and correlated with measures of LRRK2 dephosphorylation. Taken together, assessment of mtDNA damage levels may be a sensitive measure of altered kinase activity and provide an extended profile of LRRK2 kinase modulation in clinical studies.

Effects of low- and high-intensity physical exercise on physical and cognitive function in older persons with dementia: a randomized controlled trial.

BACKGROUND: Potential moderators such as exercise intensity or apolipoprotein-E4 (ApoE4) carriership may determine the magnitude of exercise effects on physical and cognitive functions in patients with dementia (PwD). We determined the effects of a 24-week aerobic and strength training program with a low- and high-intensity phase on physical and cognitive function. METHODS: In an assessor-blinded randomized trial, 91 PwD (all-cause dementia, recruited from daycare and residential care facilities, age 82.3 ± 7.0 years, 59 women, Mini-Mental State Examination 20.2 ± 4.4) were allocated to the exercise or control group. In the exercise group, PwD participated in a walking and lower limb strength training program with 12 weeks low- and 12 weeks high-intensity training offered three times/week. Attention-matched control participants performed flexibility exercises and recreational activities. We assessed adherence, compliance, and exercise intensity for each session. We assessed physical (endurance, gait speed, mobility, balance, leg strength) and cognitive (verbal memory, visual memory, executive function, inhibitory control, psychomotor speed) functions with performance-based tests at baseline and after 6, 12, 18, 24, and 36 weeks (follow-up). ApoE4 carriership was determined post-intervention. RESULTS: Sixty-nine PwD were analyzed. Their mean attendance was ~ 60% during the study period. There were no significant effects of the exercise vs. control intervention on endurance, mobility, balance, and leg strength in favor of the exercise group (Cohen's d = 0.13-0.18). Gait speed significantly improved with ~ 0.05 m/s after the high-intensity phase for exercise participants (Cohen's d = 0.41) but declined at follow-up. There were no significant effects of the exercise vs. control intervention on any of the cognitive measures (Cohen's d ~ - 0.04). ApoE4 carriership did not significantly moderate exercise effects on physical or cognitive function. CONCLUSIONS: Exercise was superior to control activities for gait speed in our sample of PwD. However, the training effect provided no protection for mobility loss after detraining (follow-up). There were no beneficial effects of the exercise vs. control group on cognitive function. Exercise intensity moderated the effects of exercise on gait speed. ApoE4 carriership moderated the effect of exercise on global cognition only (trend level). TRIAL REGISTRATION: Netherlands Trial Register, NTR5035. Registered on 2 March 2015.

Localization of p21-activated kinase 1 (PAK1) to pinocytic vesicles and cortical actin structures in stimulated cells.

The mechanisms through which the small GTPases Rac1 and Cdc42 regulate the formation of membrane ruffles, lamellipodia, and filopodia are currently unknown. The p21-activated kinases (PAKs) are direct targets of active Rac and Cdc42 which can induce the assembly of polarized cytoskeletal structures when expressed in fibroblasts, suggesting that they may play a role in mediating the effects of these GTPases on cytoskeletal dynamics. We have examined the subcellular localization of endogenous PAK1 in fibroblast cell lines using specific PAK1 antibodies. PAK1 is detected in submembranous vesicles in both unstimulated and stimulated fibroblasts that colocalize with a marker for fluid-phase uptake. In cells stimulated with PDGF, in v-Src-transformed fibroblasts, and in wounded cells, PAK1 redistributed into dorsal and membrane ruffles and into the edges of lamellipodia, where it colocalizes with polymerized actin. PAK1 was also colocalized with F-actin in membrane ruffles extended as a response to constitutive activation of Rac1. PAK1 appears to precede F-actin in translocating to cytoskeletal structures formed at the cell periphery. The association of PAK1 with the actin cytoskeleton is prevented by the actin filament-disrupting agent cytochalasin D and by the phosphatidylinositol 3-kinase inhibitor wortmannin. Co-immunoprecipitation experiments demonstrate an in vivo interaction of PAK1 with filamentous (F)-actin in stimulated cells. Microinjection of a constitutively active PAK1 mutant into Rat-1 fibroblasts overexpressing the insulin receptor (HIRcB cells) induced the formation of F-actin- and PAK1-containing structures reminiscent of dorsal ruffles. These data indicate a close correlation between the subcellular distribution of endogenous PAK1 and the formation of Rac/Cdc42-dependent cytoskeletal structures and support an active role for PAK1 in regulating cortical actin rearrangements.

Directed movement of latex particles in the gynoecia of three species of flowering plants.

The secretory matrix of the stylar-transmitting tract of angiosperms has been characterized as a nutrient medium for the growth of pollen tubes, acting to guide tubes to the ovules. When nonliving particles (latex beads) were artificially introduced onto the transmitting tracts of styles of Hemerocallis flava, Raphanus raphanistrum, and Vicia faba, they were translocated to the ovary at rates similar to those of pollen tubes. Direct observations were made on the movement of individual beads along the secretory epidermis in the style and ovary of Vicia faba. The transmitting tract may play an active role in extending tube tips to their destination in the ovary.

Inhibition of myosin light chain kinase by p21-activated kinase.

p21-activated kinases (PAKs) are implicated in the cytoskeletal changes induced by the Rho family of guanosine triphosphatases. Cytoskeletal dynamics are primarily modulated by interactions of actin and myosin II that are regulated by myosin light chain kinase (MLCK)-mediated phosphorylation of the regulatory myosin light chain (MLC). p21-activated kinase 1 (PAK1) phosphorylates MLCK, resulting in decreased MLCK activity. MLCK activity and MLC phosphorylation were decreased, and cell spreading was inhibited in baby hamster kidney-21 and HeLa cells expressing constitutively active PAK1. These data indicate that MLCK is a target for PAKs and that PAKs may regulate cytoskeletal dynamics by decreasing MLCK activity and MLC phosphorylation.

Comparison of short-term complications between unilateral and single-session bilateral surgery for medial patellar luxation in small/medium breed dogs.

OBJECTIVES: To compare the short-term complications of unilateral versus single-session bilateral medial patellar luxation surgery in small dogs. MATERIALS AND METHODS: The medical records of dogs weighing less than 13∙6 kg that underwent medial patellar luxation surgery were reviewed. Dogs were included in one of two groups based on the type of surgery performed (unilateral or single-session bilateral). Postoperative patellar luxation grade and complications were compared between the groups. RESULTS: Two hundred and fifty-one dogs were included. In the bilateral treatment group, there was less improvement in patellar luxation grade and postoperative medial patellar luxation grade was higher. The frequency of major complications was higher in the bilateral group (23%) compared with the unilateral group (12%). CLINICAL SIGNIFICANCE: Single-session bilateral medial patellar luxation surgery was associated with a higher complication rate compared to unilateral surgery in this non-randomised observational study. Staged rather than single-session bilateral surgery should be considered in dogs with bilateral medial patellar luxation to improve clinical outcome and reduce the chance of major complications.