0500 Evaluation of the Human Abuse Potential of Single Oral Doses of V117957, a Novel, Highly Potent and Selective Partial Agonist for Nociceptin/Orphanin-FQ Peptide (NOP) Receptors

Introduction

The satisfactory safety/tolerability profile of V117957, an investigational NOP receptor partial agonist, has been previously established in ~200 healthy subjects with maximum doses at 30mg following a single oral administration and 10mg once daily for 2 weeks. V117957 exhibited linear plasma exposures at doses up to 10mg. In patients with insomnia disorder, V117957 demonstrated dose-dependent improvement in sleep efficiency and sleep maintenance between 0.5mg and 10mg as measured by polysomnography and patient diaries. The current study evaluated the abuse potential and safety of V117957 in healthy, nondependent recreational polydrug users with a history of central nervous system (CNS) depressant use.

Methods

The abuse potential of V117957 (1mg, 6mg, 10mg), placebo, and triazolam (0.5mg, 1mg) were assessed in a randomized, double-blind, double-dummy, placebo- and positive-controlled crossover study. Triazolam was utilized as a positive control based on its comparable pharmacokinetic and pharmacodynamic characteristics. V117957 doses (1mg, 6mg, 10mg) were selected to represent therapeutic, mid-range supratherapeutic, and maximum-tolerated supratherapeutic doses, respectively. Subjects were qualified based on pharmacodynamic responses following a single oral 0.75mg triazolam dose. Drug liking was measured through 24 hours, including the primary endpoint of maximum “at the moment” Drug-Liking Visual Analog Scale, as recommended by FDA. Secondary endpoints included Divided Attention Test (DAT) and Choice Reaction Time (CRT).

Results

The positive control (triazolam 0.5mg, 1mg) produced statistically significant greater abuse potential and cognitive/motor impairment versus placebo, which demonstrated study validity. In contrast, V117957 at 1mg was not statistically significantly different from placebo. At the supra-therapeutic doses of 6 and 10mg, V117957 was associated with abuse potential and cognitive/motor impairment greater than placebo, yet similar to those of triazolam 0.5 and 1mg.

Conclusion

Overall, in this valid study, V117957 1mg and placebo were associated with statistically significant lower potential for abuse and reduced cognitive/motor impairment compared with the two supratherapeutic doses of V117957 (6mg, 10mg), and triazolam (0.5mg, 1mg). V117957 1mg met FDA’s statistical criterion for similarity to placebo.

Support

Funded by Imbrium Therapeutics, a subsidiary of Purdue Pharma L.P.

Gemcitabine-based adjuvant chemotherapy in subtypes of ampullary adenocarcinoma: international propensity score-matched cohort study

BACKGROUND

Whether patients who undergo resection of ampullary adenocarcinoma have a survival benefit from adjuvant chemotherapy is currently unknown. The aim of this study was to compare survival between patients with and without adjuvant chemotherapy after resection of ampullary adenocarcinoma in a propensity score-matched analysis.

METHODS

An international multicentre cohort study was conducted, including patients who underwent pancreatoduodenectomy for ampullary adenocarcinoma between 2006 and 2017, in 13 centres in six countries. Propensity scores were used to match patients who received adjuvant chemotherapy with those who did not, in the entire cohort and in two subgroups (pancreatobiliary/mixed and intestinal subtypes). Survival was assessed using the Kaplan-Meier method and Cox regression analyses.

RESULTS

Overall, 1163 patients underwent pancreatoduodenectomy for ampullary adenocarcinoma. After excluding 187 patients, median survival in the remaining 976 patients was 67 (95 per cent c.i. 56 to 78) months. A total of 520 patients (53·3 per cent) received adjuvant chemotherapy. In a propensity score-matched cohort (194 patients in each group), survival was better among patients who received adjuvant chemotherapy than in those who did not (median survival not reached versus 60 months respectively; P = 0·051). A survival benefit was seen in patients with the pancreatobiliary/mixed subtype; median survival was not reached in patients receiving adjuvant chemotherapy and 32 months in the group without chemotherapy (P = 0·020). Patients with the intestinal subtype did not show any survival benefit from adjuvant chemotherapy.

CONCLUSION

Patients with resected ampullary adenocarcinoma may benefit from gemcitabine-based adjuvant chemotherapy, but this effect may be reserved for those with the pancreatobiliary and/or mixed subtype.

Health resource utilization of labor induction versus expectant management

BACKGROUND

Although induction of labor of low-risk nulliparous women at 39 weeks reduces the risk of cesarean delivery compared with expectant management, concern regarding more frequent use of labor induction remains, given that this intervention historically has been thought to incur greater resource utilization.

OBJECTIVE

The objective of the study was to determine whether planned elective labor induction at 39 weeks among low-risk nulliparous women, compared with expectant management, was associated with differences in health care resource utilization from the time of randomization through 8 weeks postpartum.

STUDY DESIGN

This is a planned secondary analysis of a multicenter randomized trial in which low-risk nulliparous women were assigned to induction of labor at 39 weeks or expectant management. We assessed resource utilization after randomization in 3 time periods: antepartum, delivery admission, and discharge through 8 weeks postpartum.

RESULTS

Of 6096 women with data available, those in the induction of labor group (n = 3059) were significantly less likely in the antepartum period after randomization to have at least 1 ambulatory visit for routine prenatal care (32.4% vs 68.4%), unanticipated care (0.5% vs 2.6%), or urgent care (16.2% vs 44.3%), or at least 1 antepartum hospitalization (0.8% vs 2.2%, P < .001 for all). They also had fewer tests (eg, sonograms, blood tests) and treatments (eg, antibiotics, intravenous hydration) prior to delivery. During the delivery admission, women in the induction of labor group spent a longer time in labor and delivery (median, 0.83 vs 0.57 days), but both women (P = .002) and their neonates (P < .001) had shorter postpartum stays. Women and neonates in both groups had similar frequencies of postpartum urgent care and hospital readmissions (P > .05 for all).

CONCLUSION

Women randomized to induction of labor had longer durations in labor and delivery but significantly fewer antepartum visits, tests, and treatments and shorter maternal and neonatal hospital durations after delivery. These results demonstrate that the health outcome advantages associated with induction of labor are gained without incurring uniformly greater health care resource use.

Translational outcomes in a full gene deletion of ubiquitin protein ligase E3A rat model of Angelman syndrome

Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by developmental delay, impaired communication, motor deficits and ataxia, intellectual disabilities, microcephaly, and seizures. The genetic cause of AS is the loss of expression of UBE3A (ubiquitin protein ligase E6-AP) in the brain, typically due to a deletion of the maternal 15q11-q13 region. Previous studies have been performed using a mouse model with a deletion of a single exon of Ube3a. Since three splice variants of Ube3a exist, this has led to a lack of consistent reports and the theory that perhaps not all mouse studies were assessing the effects of an absence of all functional UBE3A. Herein, we report the generation and functional characterization of a novel model of Angelman syndrome by deleting the entire Ube3a gene in the rat. We validated that this resulted in the first comprehensive gene deletion rodent model. Ultrasonic vocalizations from newborn Ube3am-/p+ were reduced in the maternal inherited deletion group with no observable change in the Ube3am+/p- paternal transmission cohort. We also discovered Ube3am-/p+ exhibited delayed reflex development, motor deficits in rearing and fine motor skills, aberrant social communication, and impaired touchscreen learning and memory in young adults. These behavioral deficits were large in effect size and easily apparent in the larger rodent species. Low social communication was detected using a playback task that is unique to rats. Structural imaging illustrated decreased brain volume in Ube3am-/p+ and a variety of intriguing neuroanatomical phenotypes while Ube3am+/p- did not exhibit altered neuroanatomy. Our report identifies, for the first time, unique AS relevant functional phenotypes and anatomical markers as preclinical outcomes to test various strategies for gene and molecular therapies in AS.

P5430Long term outcomes of patients receiving Implantable Cardioverter Defibrillators in a contemporary implant population in the Essex region of the UK

Introduction

Implantable cardioverter-defibrillators (ICD) reduce the risk of sudden cardiac death in patients who are at risk and amongst among heart failure (HF) patients with a reduced left ventricular ejection fraction (LVEF).

Objective

The aim of this study was to determine the differences in outcomes amongst patients in a contemporary ICD implant population based on primary or secondary indications and an ischaemic or non-ischaemic aetiology. The primary outcome was death or appropriate device therapy for a ventricular arrhythmia. The secondary outcome was inappropriate shock therapy.

Purpose

The study cohort included consecutive patients who had an ICD or CRT-D implanted at a high-volume regional referral centre in Essex between 2014 and 2015. The censor point for follow up was 31/12/2018. Cumulative incidences were analysed by the method of Kaplan–Meier and compared using the log-rank test. In addition, the relationship between several clinical variables were tested in a multivariate Cox model to predict long-term mortality and this is described with hazard ratios (HR) and 95% CI.

Results

407 patients who received ICD treatment were followed up for a mean of 50±4 months. 63% had an Ischaemic cardiomyopathy and 60% had a primary prevention indication. Majority were men (81.5%), mean LVEF was (31±11) and mean age (71±11). The incidence of appropriate ICD therapy at 1-year post ICD insertion was 6.8% in all patients. This was significantly higher in patients with a secondary prevention indication compared to primary prevention (11.7% v 3.6% p=0.015) but similar in ischaemic compared to non-ischaemic patients (7.8% v 5.2% p=0.46). 1.9% patients had an inappropriate shock at 1 year and between group rate was similar. Overall 8.1% of patients did not survive beyond 1-year post implant with a mean time to death of 5.6±3.6 months. The cumulative incidence of the primary end-point at 1 year was similar in ischaemic and non-Ischaemic patients (7.8% v 8.6%; HR: 1.04, 95% CI 0.7–1.5, p=0.83) but was significantly higher at the end of study period in patients with an ischaemic aetiology (32.4% v 21%; HR: 1.59, 95% CI: 1.1–2.4, p=0.024) (Fig.1). In an adjusted Cox Hazard model, appropriate ICD therapy at 1 year (HR: 0.28, 95% CI: 0.17–0.47, p<0.001) and a secondary indication for ICD treatment (HR: 0.47, 95% CI: 0.31–0.73, p=0.001) were strongly associated with long-term mortality.

Figure 1

Conclusions

Our study highlights outcomes in a long-term follow up of ICD patients and in light of the debate around the DANISH trial, we have shown that at 1 year, the benefit of ICD therapy is comparable in non-ischaemic compared to ischaemic cardiomyopathies. Moreover, patients who had an ICD implanted for secondary prevention had a 3-fold mortality benefit at 1 year and had a higher rate of death. Appropriate ICD therapy and a secondary prevention indication predicted long term mortality.

Three phylogenetic groups have driven the recent population expansion of Cryptococcus neoformans

Cryptococcus neoformans (C. neoformans var. grubii) is an environmentally acquired pathogen causing 181,000 HIV-associated deaths each year. We sequenced 699 isolates, primarily C. neoformans from HIV-infected patients, from 5 countries in Asia and Africa. The phylogeny of C. neoformans reveals a recent exponential population expansion, consistent with the increase in the number of susceptible hosts. In our study population, this expansion has been driven by three sub-clades of the C. neoformans VNIa lineage; VNIa-4, VNIa-5 and VNIa-93. These three sub-clades account for 91% of clinical isolates sequenced in our study. Combining the genome data with clinical information, we find that the VNIa-93 sub-clade, the most common sub-clade in Uganda and Malawi, was associated with better outcomes than VNIa-4 and VNIa-5, which predominate in Southeast Asia. This study lays the foundation for further work investigating the dominance of VNIa-4, VNIa-5 and VNIa-93 and the association between lineage and clinical phenotype.

WP1-22 DuraGen™ as an encapsulating material for neural stem cell delivery

Objectives

Achieving neural regeneration after spinal cord injury (SCI) represents a significant challenge. Neural stem cell (NSC) therapy offers replacement of damaged cells and delivery of pro-regenerative factors, but >95% of cells die when transplanted to sites of neural injury. Biomaterial scaffolds provide cellular protective encapsulation to improve cell survival. However, current available scaffolds are overwhelmingly not approved for human use, presenting a major barrier to clinical translation. Surgical biomaterials offer the unique benefit of being FDA-approved for human implantation. Specifically, a neurosurgical grade material, DuraGen™, used predominantly for human duraplasty has many attractive features of an ideal biomaterial scaffold. Here, we have investigated the use of DuraGen™ as a 3D cell encapsulation device for potential use in combinatorial, regenerative therapies.

Methods

Primary NSCs were seeded into optimised sheets of DuraGen™. NSC growth and fate within DuraGen™ were assessed using 3D microscopic fluorescence imaging techniques.

Results

DuraGen™ supports the survival (ca 95% viability, 12 days) and 3D growth of NSCs. NSC phenotype, proliferative capacity and differentiation into astrocytes, neurons and oligodendrocytes were unaffected by DuraGen™.

Conclusions

A ‘combinatorial therapy’, consisting of NSCs protected within a DuraGen™ matrix, offers a potential clinically translatable approach for neural cell therapy.

A longitudinal assessment of periodontal health status in 53 Labrador retrievers

OBJECTIVES

To determine the incidence and rates of progression of gingivitis and periodontitis in Labrador retrievers.

MATERIALS AND METHODS

Fifty-three dogs, aged 1·1 to 5·9 years, had their periodontal health assessed every 6 months for up to 2 years. The extent of gingivitis and periodontitis was measured around the whole gingival margin of every tooth under general anaesthesia.

RESULTS

All dogs had gingivitis at the initial assessment. The majority (64·2%) of tooth aspects had very mild gingivitis. The palatal/lingual aspect of all tooth types was most likely to show bleeding when probed: 63·0% of these aspects had mild or moderate gingivitis. Over 2 years, 56·6% of dogs developed periodontitis and dogs as young as 1·9 years were affected. There was a significant positive correlation between the proportion of teeth with periodontitis and age. In total, 124 teeth (5·7%) developed periodontitis; 88 (71·0%) of these were incisors. The palatal/lingual aspect of the incisors developed the disease first (2·8% of incisor aspects).

CLINICAL SIGNIFICANCE

Periodontitis developed in regions that are difficult to see in conscious dogs implying that detection and treatment of disease requires periodic sedation or anaesthesia.

Bilateral versus unilateral botulinum toxin injections for chronic anal fissure: a randomised trial

BACKGROUND

Botulinum toxin injected into the internal anal sphincter is used in the treatment of chronic anal fissure but there is no standardised technique for its administration. This randomised single centre trial compares bilateral (either side of fissure) to unilateral injection.

METHODS

Participants were randomised to receive bilateral (50 + 50 units) or unilateral (100 units) Dysport® injections into the internal anal sphincter in an outpatient setting. Injection-related pain assessed by visual analogue scale was the primary outcome measure. Secondary outcomes were healing rate, fissure pain, incontinence, and global health scores.

RESULTS

Between October 2008 and April 2012, 100 patients with chronic anal fissure were randomised to receive bilateral or unilateral injections. Injection-related pain was comparable in both groups. There was no difference in healing rate. Initially, there was greater improvement in fissure pain in the bilateral group but at 1 year the unilateral group showed greater improvement. Cleveland Clinic Incontinence score was lower in the unilateral group in the early post-treatment period and global health assessment (EuroQol EQ-VAS) was higher in the unilateral group at 1 year.

CONCLUSIONS

Injection-related pain was similar in bilateral and unilateral injection groups. Unilateral injection was as effective as bilateral injections in healing and improving fissure pain without any deterioration in continence.

Development and validation of a difficulty score to predict intraoperative complications during laparoscopic liver resection

Background

Previous studies have demonstrated that patient, surgical, tumour and operative variables affect the complexity of laparoscopic liver resections. However, current difficulty scoring systems address only tumour factors. The aim of this study was to develop and validate a predictive model for the risk of intraoperative complications during laparoscopic liver resections.

Methods

The prospectively maintained databases of seven European tertiary referral liver centres were compiled. Data from two-thirds of the patients were used for development and one-third for validation of the model. Intraoperative complications were based on a modified Satava classification. Using the methodology of the Framingham Heart Study, developed to identify risk factors that contribute to the development of cardiovascular disease, factors found to predict intraoperative complications independently were assigned points, and grouped into low-, moderate-, high- and extremely high-risk groups based on the likelihood of intraoperative complications.

Results

A total of 2856 patients were included. Neoadjuvant chemotherapy, lesion type and size, classification of resection and previous open liver resection were found to be independent predictors of intraoperative complications. Patients with intraoperative complications had a longer duration of hospital stay (5 versus 4 days; P &lt; 0·001), higher complication rates (32·5 versus 15·5 per cent; P &lt; 0·001), and higher 30-day (3·0 versus 0·3 per cent; P &lt; 0·001) and 90-day (3·8 versus 0·8 per cent; P &lt; 0·001) mortality rates than those who did not. The model was able to predict intraoperative complications (area under the receiver operating characteristic (ROC) curve (AUC) 0·677, 95 per cent c.i. 0·647 to 0·706) as well as postoperative 90-day mortality (AUC 0·769, 0·681 to 0·858).

Conclusion

This comprehensive scoring system, based on patient, surgical and tumour factors, and developed and validated using a large multicentre European database, helped estimate the risk of intraoperative complications.

Rare disruptive variants in the DISC1 Interactome and Regulome: association with cognitive ability and schizophrenia

Schizophrenia (SCZ), bipolar disorder (BD) and recurrent major depressive disorder (rMDD) are common psychiatric illnesses. All have been associated with lower cognitive ability, and show evidence of genetic overlap and substantial evidence of pleiotropy with cognitive function and neuroticism. Disrupted in schizophrenia 1 (DISC1) protein directly interacts with a large set of proteins (DISC1 Interactome) that are involved in brain development and signaling. Modulation of DISC1 expression alters the expression of a circumscribed set of genes (DISC1 Regulome) that are also implicated in brain biology and disorder. Here we report targeted sequencing of 59 DISC1 Interactome genes and 154 Regulome genes in 654 psychiatric patients and 889 cognitively-phenotyped control subjects, on whom we previously reported evidence for trait association from complete sequencing of the DISC1 locus. Burden analyses of rare and singleton variants predicted to be damaging were performed for psychiatric disorders, cognitive variables and personality traits. The DISC1 Interactome and Regulome showed differential association across the phenotypes tested. After family-wise error correction across all traits (FWERacross), an increased burden of singleton disruptive variants in the Regulome was associated with SCZ (FWERacross P=0.0339). The burden of singleton disruptive variants in the DISC1 Interactome was associated with low cognitive ability at age 11 (FWERacross P=0.0043). These results identify altered regulation of schizophrenia candidate genes by DISC1 and its core Interactome as an alternate pathway for schizophrenia risk, consistent with the emerging effects of rare copy number variants associated with intellectual disability.

Differences in trochlear parameters between native and prosthetic kinematically or mechanically aligned knees

INTRODUCTION

Kinematic (KA) and mechanical (MA) alignment techniques are two different philosophies of implant positioning that use the same TKA implants. This might generate differences in the resulting prosthetic trochleae parameters between the two techniques of alignment. Our study aim was to test the following hypotheses : (1) mechanically or kinematically aligned femoral implant understuffs the native trochlear articular surface and poorly restores the native groove orientation, and (2) the orientation of the prosthetic trochlear groove and trochlear fill are different between MA and KA.

METHODS

Three-dimensional models of the femur were made from segmentation of preoperative Magnetic Resonance Imaging scans (MRIs) of ten subjects with isolated medial tibiofemoral osteoarthritis. In-house planning and analysis software kinematically and mechanically aligned a modern cruciate retaining femoral component and determined differences in parameters of the trochlear fit between native and prosthetic trochleae, and between KA and MA prosthetic trochleae.

RESULTS

The MA prosthetic trochleae did not fill (understuffed) the entire length of the native medial facet and the proximal 70% of the native groove and lateral facet, and oriented the trochleae groove 8° more valgus than native. The KA prosthetic trochleae understuffed the proximal 70% of the native trochleae, and had a groove 6° more valgus than native. The KA trochleae understuffed the medial facet distally and oriented the groove 2° less valgus and 3° more internally rotated than the MA trochleae.

CONCLUSION

MA and KA prosthetic trochleae substantially understuff and create a prosthetic groove more valgus compared to native trochlear anatomy, and they also differed between each other regarding trochleae stuffing and groove alignment. Although randomized trials have not shown differences in patellofemoral complications between KA and MA, a femoral component designed specifically for KA that more closely restores the native trochlear anatomy might improve patient reported satisfaction and function.

LEVEL OF EVIDENCE

Level 2 controlled laboratory study.

Early outcomes of patients transferred with ruptured suprarenal aneurysm or dissection

Objective Despite centralisation of the provision of vascular care, not all areas in England and Wales are able to offer emergency treatment for patients with acute conditions affecting the aorta proximal to the renal arteries. While cardiothoracic centres have made network arrangements to coordinate care for the repair of type A dissections, a similar plan for vascular care is lacking. This study investigates early outcomes in patients with ruptured suprarenal aortic aneurysm or dissection (rSRAD) transferred to a specialist centre. Methods Retrospective observational study over a five-year period (2009-2014) assessing outcomes of patients with ruptured sRAD diagnosed at their local hospital and then transferred to a tertiary centre capable of offering such treatment. Results Fifty-two patients (median age 73 years, 32 male) with rSRAD were transferred and a further four died during transit. The mean distance of patient transfer was 35 miles (range 4-211 miles). One patient did not undergo intervention due to frailty and two died before reaching the operating theatre. A total of 23 patients underwent endovascular repair, 9 hybrid repair and 17 open surgery. Median follow-up was 12 months (range 1-43 months). Complications included paraplegia (n = 3), stroke (n = 2), type IA endoleak (n = 4); 30-day and in-hospital mortality were 16% and 27%. For patients discharged alive from hospital, one-year survival was 67%. Conclusions Although the number of patients with rSRAD is low and those who are transferred alive are a self-selecting group, this study suggests that transfer of such patients to a specialist vascular centre is associated with acceptable mortality rates following emergency complex aortic repair.

Do patient-specific instruments (PSI) for UKA allow non-expert surgeons to achieve the same saw cut accuracy as expert surgeons?

INTRODUCTION

High-volume unicompartmental knee arthroplasty (UKA) surgeons have lower revision rates, in part due to improved intra-operative component alignment. This study set out to determine whether PSI might allow non-expert surgeons to achieve the same level of accuracy as expert surgeons.

MATERIALS AND METHODS

Thirty-four surgical trainees with no prior experience of UKA, and four high-volume UKA surgeons were asked to perform the tibial saw cuts for a medial UKA in a sawbone model using both conventional and patient-specific instrumentation (PSI) with the aim of achieving a specified pre-operative plan. Half the participants in each group started with conventional instrumentation, and half with PSI. CT scans of the 76 cut sawbones were then segmented and reliably orientated in space, before saw cut position in the sagittal, coronal and axial planes was measured, and compared to the pre-operative plan.

RESULTS

The compound error (absolute error in the coronal, sagittal and axial planes combined) for experts using conventional instruments was significantly less than that of the trainees (11.6°±4.0° v 7.7° ±2.3º, p = 0.029). PSI improved trainee accuracy to the same level as experts using conventional instruments (compound error 5.5° ±3.4º v 7.7° ±2.3º, p = 0.396) and patient-specific instruments (compound error 5.5° ±3.4º v 7.3° ±4.1º, p = 0.3). PSI did not improve the accuracy of high-volume surgeons (p = 0.3).

CONCLUSIONS

In a sawbone model, PSI allowed inexperienced surgeons to achieve more accurate saw cuts, equivalent to expert surgeons, and thus has the potential to reduce revision rates. The next test will be to determine whether these results can be replicated in a clinical trial.

The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis

INTRODUCTION

Kinematic alignment (KA) technique is an alternative technique for positioning a TKA, which aims a patient-specific implant positioning in order to reproduce the pre-arthritic knee anatomy. Because reliability in implant positioning is of interest to obtain reproducible good functional results, our study tests the hypothesis that the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically aligned femoral component are similar.

METHODS

Preoperative knee magnetic resonance imaging (MRI) and postoperative knee computed tomography (CT) of 13 patients implanted with a KA Persona^® TKA (Zimmer, Warsaw, USA) using manual instrumentation (kinematically-aligned TKA procedure pack^®, Zimmer Biomet, Warsaw, USA) were segmented to create 3D femoral models. The kinematic alignment position of the femoral component was planned on the 3D model created from the preoperative MRI. Differences in the positions of the planned and surgically implanted kinematically-aligned femoral component were determined with in-house analysis software.

RESULTS

The average differences between the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically-aligned femoral component were inferior to 1mm and no statistically significant. In terms of variability, 62% (8/13) of performed implants matched all four positions within 1.5mm, and the maximum difference was 3mm.

CONCLUSION

In this small series, intraoperative kinematic positioning of the femoral component with the specific manual instrumentation closely matched the planned position, which suggests that this technique reliably aligned the flexion-extension axis of the femoral component to the cylindrical axis.

LEVEL OF EVIDENCE

Level 3.