Immunohistochemistry Aids in the Diagnosis of Blastic Plasmacytoid Dendritic Cell Neoplasm in a Patient with Multiple Cutaneous Plaques and Nodules

Introduction/Objective

Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) is a rare hematologic malignancy of plasmacytoid dendritic cell precursors with an estimated incidence of 0.04 cases per 100,000 in the US. Given the cutaneous tropism of BPDCN, it should be differentiated from other CD56+ hematopoietic neoplasms with skin involvement such as CD56+ AML, extranodal NK/T-cell lymphoma, and other T-cell lymphomas.

Methods/Case Report

A 71-year-old male presented to the emergency department with asymptomatic, pink- violaceous plaques/nodules on the trunk for 3 months. One month prior, a dermatologist diagnosed epidermal inclusion cysts that were left untreated. The nodules progressed and a course of steroids prescribed by a primary care physician provided short term improvement before the lesions flared again. Review of systems and vitals were normal. Biopsies of representative lesions sent for histologic examination showed a diffuse dermal infiltrate of small to medium atypical cells with irregular nuclear contours, fine chromatin, one to several nucleoli and scant cytoplasm. Immunohistochemistry showed these cells were positive for CD2, CD4, CD56 and CD45 with strong expression of BCL2 and focal CD123. The cells were negative for CD3, CD20, CD79a, CD8, CD30, ALK-1, MUM-1, CD10, Cyclin- D1, C-MYC, EBER, BCL6, Langerin, Granzyme, TIA1, CD68, CD163, MPO, and Lysozyme. The histology and immunoprofile were consistent with BPDCN. A bone marrow biopsy showed cells with similar morphology and staining pattern, including expression of CD123.Treatment with chemotherapy and Tagraxofusp, was initiated. Within a week, the patient showed near resolution of cutaneous lesions. Repeat bone marrow aspirate and flow cytometry a month later showed no malignant cells.

Results (if a Case Study enter NA)

NA

Conclusion

We present this case as a rare hematologic malignancy with a challenging clinical and histopathologic diagnosis. The histologic findings suggested either a high grade myeloid or lymphoid malignancy. The combination of CD3-/CD56+/CD4+/CD123+ in the lesional cells helped establish the diagnosis of BPDCN, allowing for prompt treatment.

Clinical Outcome of Drug-Eluted Stenting (Zilver PTX) in Patients With Femoropopliteal Occlusive Disease a Single Center Experience

BACKGROUND

Few industry sponsored trials reported satisfactory outcomes in the use of drug-eluting stents (DES) for treatment of femoropopliteal arterial disease. This study analyzed the early/late clinical outcome from a real world single center.

PATIENT POPULATIONS/METHODS

A total of 115 limbs treated with Zilver PTX were analyzed for: major adverse limb event (MALE: above ankle limb amputation/major intervention at 1 year), major adverse events (MAEs; death, amputation, and target lesion thrombosis/reintervention), primary patency (based on duplex ultrasound ± ankle brachial indexes), limb salvage, and amputation free survival rates (AFS) at 1 and 2 years.

RESULTS

Indications included claudication in 32% and critical limb threatening ischemia (CLTI) in 68%. Lesions treated included: superficial femoral artery (SFA) 66%, both SFA and popliteal artery (PA) 19% and PA 15%. Mean lesion length was 21 cm and 68% had total occlusion. 45% were Trans-Atlantic Inter-Society Consensus (TASC) TASC II D lesions and 55% A-C lesions. Mean follow-up was 18.4 months (1-76 months). Perioperative major morbidity rate was 8.7% with 0% mortality. MALE rate at 1 year was 17% (13.5% for claudication vs 19.2% for CLTI, p=0.4499). MAE rate was 30% for claudication versus 52% for CLTI (p=0.0392). Overall primary patency rates at 1 and 2 years were 75% and 54% (86% and 71% for claudication vs 70% and 46% for CLTI, respectively, p=0.0213). Primary patency rates at 1 and 2 years were 94% and 88% for TASC A-C lesions versus 50% and 16% for TASC D lesions (p<0.0001). Overall freedom from MALE rate at 1 and 2 years were 85% and 79% (86% and 86% for claudication vs 84% and 74% for CLTI, p=0.2391). These rates were 96% and 93% for TASC A-C lesions versus 70% and 50% for D lesions, respectively (p<0.0001). Limb salvage rates at 1 and 2 years were 93% and 86% (100% and 100% for claudication vs 89% and 78% for CLTI, p=0.012). Overall AFS rates at 1 and 2 years were 79% and 71% (93% and 82% for TASC A-C vs 59% and 59% for D lesions, p=0.001).

CONCLUSION

Clinical outcomes after DES (Zilver PTX) in femoropopliteal arterial lesions were satisfactory for TASC A-C lesions but inferior/unsatisfactory for TASC D lesions.

Achilles tendon rupture: what you need to know

Heel pain and a history of a 'pop' or feeling 'something go' are the buzz phrases classically associated with Achilles tendon rupture. However, the diagnosis is often missed in clinical practice because of the assumption that this is a sporting injury suffered only by the young or middle-aged. In a sedentary older patient, the injury may be dismissed as an ankle sprain. If swelling is present but no injury is recalled then deep vein thrombosis is suspected, but Achilles rupture is not. The diagnosis of Achilles tendon rupture is clinical, based on history and examination. Radiological imaging (ultrasound scan) is useful to plan orthopaedic management and exclude concomitant deep vein thrombosis. In most cases, non-operative management with the ankle held plantar flexed in a boot is the current best practice.

Clinical outcome of drug-coated balloon angioplasty in patients with femoropopliteal disease: A real-world single-center experience

BACKGROUND

Several multicenter industry-sponsored clinical trials reported satisfactory results in the use of drug-coated balloons (DCBs) for treatment of femoropopliteal occlusive disease. However, few single-center studies have been published to verify the outcome from real-world experience.

METHODS

In this study, 228 patients treated with DCB angioplasty (Lutonix 0.35; Bard, Tempe, Arizona) were analyzed. Perioperative major adverse events (death, amputation, target lesion thrombosis or reintervention) were calculated. Kaplan-Meier analysis was used to estimate primary patency rates (based on duplex ultrasound with or without ankle-brachial index) and limb salvage rates.

RESULTS

Lesions treated were primarily TransAtlantic Inter-Society Consensus (TASC) type C and D lesions. Indications included claudication (Rutherford classes 2 and 3) in 40% and critical limb ischemia (CLI; Rutherford classes 4 and 5) in 60%. Lesions treated included 61% in the superficial femoral artery, 15% in the popliteal artery, and 24% in both superficial femoral artery and popliteal artery. Mean follow-up was 12.2 months (range, 1-42 months). Overall perioperative morbidity and mortality rates were 13% and 1%. The perioperative major adverse event rate was 3%. Symptom relief (improvement of one Rutherford category or more) was obtained in 64%. Primary patency rates were 56% and 39% at 1 year and 2 years, respectively. Limb salvage rates were 92% and 83% at 1 year and 2 years. Patients with claudication had a lower rate of early perioperative complications (4% vs 19%; P = .001). Symptom improvement was 76% for claudication vs 49% for CLI (P < .001). Overall, major amputation rate was 0% for claudication vs 13% for CLI (P < .001). The primary patency rates at 1 year and 2 years were 59% and 41% for claudication vs 54% and 37% for CLI (P = .307). The assisted primary patency rates at 1 year and 2 years were 72% and 52% for claudication vs 64% and 46% for CLI (P = .223). Primary patency rates at 1 year and 2 years were 82% and 71% for TASC A to C lesions vs 29% and 14% for TASC D lesions (P < .001). Limb salvage rates at 1 year and 2 years were 100% and 100% for claudication vs 85% and 74% for CLI (P < .001).

CONCLUSIONS

Clinical outcomes after DCB angioplasty in femoropopliteal lesions were inferior to what has been reported in previous studies, particularly for TASC D lesions. Further investigation from real-world experience with long-term follow-up is needed to confirm these results.

Getting It Right First Time: the national survey of surgical site infection rates in NHS trusts in England

INTRODUCTION

Surgical site infections are associated with increased morbidity and mortality in patients. The Getting It Right First Time surgical site infection programme set up a national survey to review surgical site infection rates in surgical units in England. The objectives were for frontline clinicians to assess the rates of infection following selected procedures, to examine the risk of significant complications and to review current practice in the prevention of surgical site infection.

METHODS

A national survey was launched in April 2017 to assess surgical site infections within 13 specialties: breast surgery, cardiothoracic surgery, cranial neurosurgery, ear, nose and throat surgery, general surgery, obstetrics and gynaecology, ophthalmology, oral and maxillofacial surgery, orthopaedic surgery, paediatric surgery, spinal surgery, urology and vascular surgery. All participating trusts prospectively identified and collected supporting information on surgical site infections diagnosed within the six-month study period.

RESULTS

Data were received from 95 NHS trusts. A total of 1807 surgical site infection cases were reported. There were variations in rates reported by trusts across specialties and procedures. Reoperations were reported in 36.2% of all identified cases, and surgical site infections are associated with a delayed discharge rate of 34.1% in our survey.

CONCLUSION

The Getting It Right First Time surgical site infection programme has introduced a different approach to infection surveillance in England. Results of the survey has demonstrated variation in surgical site infection rates among surgical units, raised the importance in addressing these issues for better patient outcomes and to reduce the financial burden on the NHS. Much work remains to be done to improve surgical site infection surveillance across surgical units and trusts in England.

A systematic review of short metaphyseal loading cementless stems in hip arthroplasty

AIMS

Short-stemmed femoral implants have been used for total hip arthroplasty (THA) in young and active patients to conserve bone, provide physiological loading, and reduce the incidence of thigh pain. Only short- to mid-term results have been presented and there have been concerns regarding component malalignment, incorrect sizing, and subsidence. This systematic review reports clinical and radiological outcomes, complications, revision rates, and implant survival in THA using short-stemmed femoral components.

MATERIALS AND METHODS

A literature review was performed using the EMBASE, Medline, and Cochrane databases. Strict inclusion and exclusion criteria were used to identify studies reporting clinical and radiological follow-up for short-stemmed hip arthroplasties.

RESULTS

A total of 28 studies were eligible for inclusion. This included 5322 hips in 4657 patients with a mean age of 59 years (13 to 94). The mean follow-up was 6.1 years (0.5 to 20). The mean Harris Hip Score improved from 46 (0 to 100) to 92 (39 to 100). The mean Oxford Hip Score improved from 25 (2 to 42.5) to 35 (12.4 to 48). The mean Western Ontario & McMaster Universities Osteoarthritis Index improved from 54 (2 to 95) to 22 (0 to 98). Components were aligned in a neutral coronal alignment in up to 90.9% of cases. A total of 15 studies reported component survivorship, which was 98.6% (92% to 100%) at a mean follow-up of 12.1 years.

CONCLUSION

Short-stemmed femoral implants show similar improvement in clinical and radiological outcomes compared with conventional length implants. Only mid-term survivorship, however, is known. An abundance of short components have been developed and used commercially without staged clinical trials. Long-term survival is still unknown for many of these components. There remains tension between innovation and the moral duty to ensure that the introduction of new implants is controlled until safety and patient benefit are demonstrated. Implant innovation and subsequent use should be driven by proven clinical outcomes, rather than market and financial forces, and ethical practice must be ensured. Cite this article: Bone Joint J 2019;101-B:502-511.

Does lateral lift-off occur in static and dynamic activity in a medially spherical total knee arthroplasty? A pulsed-fluoroscopic investigation

OBJECTIVES

The medially spherical GMK Sphere (Medacta International AG, Castel San Pietro, Switzerland) total knee arthroplasty (TKA) was previously shown to accommodate lateral rollback while pivoting around a stable medial compartment, aiming to replicate native knee kinematics in which some coronal laxity, especially laterally, is also present. We assess coronal plane kinematics of the GMK Sphere and explore the occurrence and pattern of articular separation during static and dynamic activities.

METHODS

Using pulsed fluoroscopy and image matching, the coronal kinematics and articular surface separation of 16 well-functioning TKAs were studied during weight-bearing and non-weight-bearing, static, and dynamic activities. The closest distances between the modelled articular surfaces were examined with respect to knee position, and proportions of joint poses exhibiting separation were computed.

RESULTS

Overall, 1717 joint poses were analyzed. At a 1.0 mm detection threshold, 37 instances of surface separation were observed in the lateral compartment and four medially (p < 0.001). Separation was activity-dependent, both laterally and medially (p < 0.001), occurring more commonly during static deep flexion in the lateral compartment, and during static rotation in the medial compartment. Lateral separation occurred more frequently than medial during kneeling (7/14 lateral vs 1/14 medial; p = 0.031) and stepping (20/1022 lateral vs 0/1022 medial; p < 0.001). Separation varied significantly between individuals during dynamic activities.

CONCLUSION

No consistent association between closest distances of the articular surfaces and knee position was found during any activity. Lift-off was infrequent and depended on the activity performed and the individual knee. Lateral separation was consistent with the design rationale. Medial lift-off was rare and mostly in non-weight-bearing activities.Cite this article: S. Key, G. Scott, J.G. Stammers, M. A. R. Freeman†, V. Pinskerova, R. E. Field, J. Skinner, S. A. Banks. Does lateral lift-off occur in static and dynamic activity in a medially spherical total knee arthroplasty? A pulsed-fluoroscopic investigation. Bone Joint Res 2019;8:207-215. DOI: 10.1302/2046-3758.85.BJR-2018-0237.R1.

The incidence of carotid in-stent stenosis is underestimated ≥50% or ≥80% and its clinical implications

BACKGROUND

The incidence of carotid in-stent stenosis has been reported to vary between 1% and 30%. Most published studies have short follow-up, which may lead to underestimation of the incidence of in-stent stenosis. This study analyzed the incidence of ≥50% and ≥80% in-stent stenosis using validated duplex ultrasound criteria and its clinical implications.

METHODS

This is a retrospective analysis of prospectively collected data of 450 carotid artery stenting (CAS) procedures (February 6, 2001-December 19, 2016). All patients had postoperative carotid duplex ultrasound examination, which was repeated at 1 month, 6 months, and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate rates of freedom from ≥50% in-stent stenosis (internal carotid artery peak systolic velocity of ≥224 cm/s) and ≥80% in-stent stenosis (internal carotid artery peak systolic velocity of ≥325 cm/s), freedom from reintervention, and survival.

RESULTS

The mean age was 68.3 years, with a mean follow-up of 40.3 months. A total of 201 patients (45% [201/450]) had CAS for symptomatic disease. Primary CAS was done in 291 patients (65%); in the remaining 35%, CAS was done for postcarotid endarterectomy (CEA) stenosis. A total of 101 patients (23%) had ≥50% late carotid in-stent stenosis, and of these, 33 (7.4%) had ≥80% in-stent stenosis. Nineteen patients (4.3%) developed late transient ischemic attack and three (0.7%) late stroke. Twenty-three (5.2%) patients had late reintervention. Rates of freedom from ≥50% in-stent stenosis in the whole series were 85%, 79%, 75%, 72%, and 70% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥50% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were not statistically significant (P = .540). The rates of freedom from ≥80% in-stent stenosis for the whole series were 96%, 95%, 93%, 90%, and 89% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥80% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were also not statistically significant (P = .516). Rates of freedom from reintervention were 98%, 96%, 93%, 93%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively, and there were no significant differences between primary CAS and CAS for post-CEA stenosis (P = .939). The overall late survival rates were 99%, 97%, 96%, 94%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years.

CONCLUSIONS

The incidence of ≥50% in-stent stenosis is relatively high; however, the rates of ≥80% stenosis and late neurologic events are low. Longer follow-up of patients with ≥50% carotid in-stent stenosis may yield higher incidence of ≥80% stenosis.

Use of Online Health Information by Geriatric and Adult Emergency Department Patients: Access, Understanding, and Trust

OBJECTIVE

The objective was to characterize geriatric patients' use of online health information (OHI) relative to younger adults and assess their comfort ith OHI compared to health information (HI) from their physician.

METHODS

This was a prospective cross-sectional survey study of adult emergency department (ED) patients. The survey assessed patients' self-reported use of OHI in the past year and immediately prior to ED visit and analyzed differences across four age groups: 18-39, 40-64, 65-74, and 75+. Patients' ability to access, understand, and trust OHI was assessed using a 7-point Likert scale and compared to parallel questions regarding HI obtained from their doctor. Patient use of OHI was compared across age groups. Comfort with OHI and HI obtained from a doctor was compared across age groups using the Kruskal-Wallis test. Comparisons between sources of HI were made within age groups using the Wilcoxon signed-rank test.

RESULTS

Of 889 patients who were approached for study inclusion, 723 patients (81.3%) completed the survey. The majority of patients had used OHI in the past year in all age groups, but older patients were less likely to have used OHI: age 18-39, 90.3%; 40-64, 85.3%; 65-74, 76.4%; and 75+, 50.7% (p < 0.001). The youngest patients were most likely to have used OHI prior to coming to the ED, 47.1%, 28.3%, 17.1%, and 8.0% (p < 0.001). Older patients were more likely to have an established doctor-18-39, 79.4%; 40-64, 91.1%; 65-74, 97.5%; and 75+ 97.4% (p < 0.001)-and were more likely to have contacted their doctor prior to their ED visit: 36.7, 40.2, 46.7, and 53.5% (p = 0.02). The oldest patients were most likely to find HI more accessible from their doctor than the Internet, while the youngest patients found HI more accessible on the Internet than from their doctor. Regardless of age, patients noted that information from their physician was both easier to understand and more trustworthy than information found on the Internet.

CONCLUSION

Although many older patients used OHI, they were less likely than younger adults to use the Internet immediately prior to an ED visit. Despite often using OHI, patients of all age groups found healthcare information from their doctor easier to understand and more trustworthy than information from the Internet. As health systems work to efficiently provide information to patients, addressing these perceived deficiencies may be necessary to build effective OHI programs.

Abstract P6-11-01: CDK2 inhibition prevents ERpS294 and restores the ability of tamoxifen to induce regression in breast tumors expressing mutant ESR1

This abstract was withdrawn by the authors.

Hepatitis C virus among genitourinary clinic attenders in Scotland: unlinked anonymous testing

Our objective is to gauge the prevalence of hepatitis C virus (HCV) antibodies among a population at risk of contracting sexually transmitted infections (STIs) and, thus, the efficiency with which the virus is transmitted sexually. The investigators undertook an unlinked anonymous HCV antibody testing study of residual syphilis serology specimens taken from attenders of genitourinary clinics in Glasgow, Edinburgh and Aberdeen during 1996/97. The results were linked to non-identifying risk information. Anti-HCV prevalences among non-injecting heterosexual men and women, and non-injecting homosexual/bisexual males ranged between 0 and 1.2%; the only exception to this was a 7.7% (4/52) prevalence among homosexual/bisexual males in Aberdeen. The overall anti-HCV prevalence for homosexual/bisexual males was 0.6% (4/668), for heterosexual males 0.8% (32/4135), for heterosexual females 0.3% (10/3035) and for injecting drug users 49% (72/148). Only 3 (all female) of the 46 non-injectors who were antibody positive were non-UK nationals or had lived abroad. HCV antibody positive injectors were less likely to have an acute STI and more likely to know their HCV status than non-injectors; no differences in these parameters were found between positive and negative non-injectors on anonymous HCV antibody testing. Our findings are in keeping with the prevailing view that HCV can be acquired through sexual intercourse but, for most people, the probability of this occurring is extremely low. Interventions to prevent the spread of HCV should be targeted mainly at injecting drug user (IDU) populations.

The Dentin Matrix Protein 1 (Dmp1) is Specifically Expressed in Mineralized, but not Soft, Tissues during Development

Dentin Matrix Protein 1 ( Dmp1) was originally identified from dentin. However, its expression and function in vivo are not clear. To clarify these two issues, we have generated mice carrying a truncated Dmp1 gene by using gene targeting to replace exon 6 with a lacZ gene. Northern blot analysis shows the expected 5.8-kb Dmp1-lacZ fusion transcript and loss of the wild-type 2.8-kb Dmp1 transcript, confirmed by a lack of immunostaining for the protein. Using heterozygous animals, we demonstrate that Dmp1 is specific for mineralized tissues. Not previously shown, Dmp1 is also expressed in pulp cells. Dmp1-deficient embryos and newborns display no apparent gross abnormal phenotype, although there are a modest expansion of the hypertrophic chondrocyte zone and a modest increase in the long bone diameter. This suggests that DMP1 is not essential for early mouse skeletal or dental development.

UKCC staff set for showdown with ralph

The management dispute at nursing's regulatory body is expected to enter its final phase later this week, with eight senior staff set to issue an official grievance against Registrar Colin Ralph.

Comparison of time to undetectable HIV viral load in the first 16 weeks after the start of three and four antiretroviral regimens

The aim of this paper is to compare the time to a viral load <50 copies/mL of three or four antiretroviral therapy (ART) regimens among ART naïve patients within the first 16 weeks after the start of treatment. A retrospective study was carried out on ART naïve patients who started HAART between 1 January 1999 and 1 January 2004. ART naïve patients with a viral load >5.3 log10 copies/mL at the time of treatment were routinely started on four ART regimens in one of the HIV centres in Edinburgh. These patients were compared with ART naïve patients with viral load >5.3 log10 copies/mL at the time of start of three ART regimens in the other centre within the study period. During the study period, of 93 ART naïve patients with a viral load >5.3 log10 copies/mL, 56 and 37 commenced four drug and three drug regimens, respectively. Patients in each group were matched for their age, prevalence of HCV, median age, and median viral load at the start of therapy; however, patients on three drug regimens had significantly lower CD4 counts ( P<0.01). The median time to undetectable viral load was 13.5 weeks for three and four drug regimens ( P>0.05). By the time of undetectable viral load, there was no difference in the CD4 count of patients on three or four drug regimens. Similar proportions of immunosuppressed patients on three and four ART regimens had undetectable viral load within the first 16 weeks of therapy.

Heterosexual men and women with HIV test positive at a later stage of infection than homo- or bisexual men

The current strategy of offering HIV testing to individuals with known risk has had no impact on the reduction in the number of patients diagnosed with immune suppression of infection. A prospective observational study to compare the baseline CD4+ T-cell counts in HIV-infected homosexual/bisexual men, intravenous drug users, heterosexual men and women diagnosed in GUM/RIDU and that of patients diagnosed during routine maternal screening for HIV between December 1999 and January 2003 was carried out at the Departments of Genitourinary Medicine (GUM), Regional Infectious Disease Unit (RIDU) and Obstetrics in Edinburgh.

Late presentation was defined as positive HIV test with baseline CD4+ T-cell count of less than 200 cells/mL.

During the study period, 189 patients tested in GUM/RIDU setting and 13 screened women were diagnosed with HIV infection. Thirty-four percent of the former and 38% of the latter group had CD4+ T-cell count of less than 200 cells/mL by the time of diagnosis. Heterosexual individuals contributed to 78% of HIV tests in the GUM/RIDU setting. Amongst the 78 HIV-infected heterosexual individuals diagnosed in GUM/RIDU 45% were late presenters. Significantly fewer homosexual men were late presenters. There was no difference between the proportion of late presenters amongst women screened at the antenatal (5/13) compared to heterosexual patients diagnosed in GUM/RIDU (35/78). A significant number of HIV infected heterosexual patients are late presenters in the HIV testing at GUM/RIDU. HIV screening programmes for heterosexual individuals in any medical encounter may reduce the number of late presenters.

Can a total knee arthroplasty be both rotationally unconstrained and anteroposteriorly stabilised? A pulsed fluoroscopic investigation

OBJECTIVES

Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with flexion, and total knee arthroplasty (TKA) prostheses have been designed on this basis. Recent work, however, has proposed that at a position of between 0° and 120° the medial femoral condyle does not move anteroposteriorly whereas the lateral femoral condyle tends, but is not obliged, to roll back - a combination of movements which equates to tibial internal/ femoral external rotation with flexion. The aim of this paper was to assess if the articular geometry of the GMK Sphere TKA could recreate the natural knee movements in situ/in vivo.

METHODS

The pattern of knee movement was studied in 15 patients (six male: nine female; one male with bilateral TKAs) with 16 GMK Sphere implants, at a mean age of 66 years (53 to 76) with a mean BMI of 30 kg/m(2) (20 to 35). The motions of all 16 knees were observed using pulsed fluoroscopy during a number of weight-bearing and non-weight-bearing static and dynamic activities.

RESULTS

During maximally flexed kneeling and lunging activities, the mean tibial internal rotation was 8° (standard deviation (sd) 6). At a mean 112° flexion (sd 16) during lunging, the medial and lateral condyles were a mean of 2 mm (sd 3) and 8 mm (sd 4) posterior to a transverse line passing through the centre of the medial tibial concavity. With a mean flexion of 117° (sd 14) during kneeling, the medial and lateral condyles were a mean of 1 mm (sd 4) anterior and 6 mm (sd 4) posterior to the same line. During dynamic stair and pivoting activities, there was a mean anteroposterior translation of 0 mm to 2 mm of the medial femoral condyle. Backward lateral condylar translation occurred and was linearly related to tibial rotation.

CONCLUSION

The GMK Sphere TKA in our study group shows movements similar in pattern, although reduced in magnitude, to those in recent reports relating to normal knees during several activities. Specifically, little or no translation of the medial femoral condyle was observed during flexion, but there was posterior roll-back of the lateral femoral condyle, equating to tibiofemoral rotation. We conclude that the GMK Sphere is anteroposteriorly stable medially and permits rotation about the medial compartment.Cite this article: Professor G. Scott. Can a total knee arthroplasty be both rotationally unconstrained and anteroposteriorly stabilised?: A pulsed fluoroscopic investigation. Bone Joint Res 2016;5:80-86. DOI: 10.1302/2046-3758.53.2000621.

Physiologically Based Models in Regulatory Submissions: Output From the ABPI/MHRA Forum on Physiologically Based Modeling and Simulation

Under the remit of the Ministerial Industry Strategy Group (MISG), the Association of the British Pharmaceutical Industry (ABPI) and Medicines and Healthcare products Regulatory Agency (MHRA) hosted a meeting to explore physiologically based pharmacokinetic modeling and simulation, focusing on the clinical component of regulatory applications. The meeting took place on 30 June 2014 with international representatives from industry, academia, and regulatory agencies. Discussion topics were selected to be complementary to those discussed at an earlier US Food and Drug Administration (FDA) meeting. This report summarizes the meeting outcomes, focusing on the European regulatory perspective.