Infrequent fractures and resilient bone mineral density: bone health in patients with Fanconi anemia.

Not available.

Gonadal function in pediatric Fanconi anemia patients treated with hematopoietic stem cell transplant.

Gonadal dysfunction and reduced fertility are clinical manifestations well described in patients with Fanconi anemia (FA) and following hematopoietic stem cell transplantation (HSCT). It is difficult to differentiate gonadal dysfunction from the primary disease itself or from HSCT procedures. Therefore, it is important to manage expectations about gonadal failure and infertility for all patients with FA, regardless of the HSCT status. We performed a retrospective analysis of 98 pediatric patients with FA who were transplanted between July 1990 and June 2020 to evaluate the incidence of gonadal dysfunction in female and male patients with FA. New-onset premature ovarian insufficiency (POI) was diagnosed in a total of 30 (52.6%) patients. Follicle-stimulating hormone and luteinizing hormone levels were increased in patients diagnosed with POI. Anti- Mullerian hormone levels declined in POI patients after HSCT (r2=0.21; P=0.001). Twenty (48.8%) male patients were diagnosed with testicular failure. Follicle-stimulating hormone levels increased after HSCT even in patients without testicular failure (r2=0.17; P=0.005). Inhibin B levels decreased over time after HSCT in patients with testicular failure (r2=0.14; P=0.001). These data indicate brisk decline in already impaired gonadal function in transplanted children with FA.

Male pediatric, adolescent, and young adult reproductive survivorship.

As pediatric, adolescent, and young adult cancer survival rates increase, emphasis is placed on reducing late effects, including reproductive complications and potential impact to fertility. Male survivors are at risk of abnormalities in sperm, hormone deficiencies, and sexual dysfunction. This can impact one's progression into puberty and ability to have a biological child and impacts quality of life following treatment. Access to reproductive care is important and requires patient assessment and appropriate referral to reproductive specialists. This review addresses reproductive complications associated with therapy, standard-of-care testing, and therapeutic interventions. The psychologic impact on psychosexual functioning is also addressed.

Cemented Femoral Stem Fixation: Back to the Future.

BACKGROUND: Periprosthetic fractures following elective and nonelective hip arthroplasty remain one of the most common modes of early failure. METHODS: This symposium will explore the current role of cemented fixation and periprosthetic fracture, focusing on history and rationale for cemented stem fixation, registry data, and other potential advantages of cemented stem fixation. A meticulous and methodical surgical technique of cemented stem fixation is paramount to the success and will be thoroughly discussed. RESULTS: The role of stem fixation, and its effect on periprosthetic fracture is well-documented in the literature. Yet despite this, the utilization of cemented stem fixation remains low in the United States. This paradox is multifactorial. CONCLUSION: In addition to a notable reduction in the risk of periprosthetic femur fractures, cemented stem fixation has numerous other advantages and is reproducible with a methodical surgical technique.

Mixed manufacturer dual mobility bearing and the Exeter V40 Stem: is it safe? Short-term results in primary and revision hip replacement.

The aim is to review clinical and radiological outcomes for all cases of primary and revision THA, combining a cemented stem (Exeter V40) with a dual mobility component from a different manufacturer (SERF Novae), to evaluate whether concerns regarding mixing components from different manufacturers are justified. We identified 72 hip replacements performed between May 2010 and December 2015 using the SERF Novae dual mobility cup with an Exeter V40 stem, the majority of which were cemented (90%) and revisions (58%). Patients were evaluated clinically and radiologically at a minimum of two years. There were five (6.9%) dislocations; three (4.2%) requiring revision - one of which was an intra-prosthetic disarticulation and two infections. No cases were lost to follow-up and 49 surviving cases were reviewed at a mean of 4.0 (range 1.8-8.1) years following surgery. Pain and functional outcome scores all improved. There were no radiological failures and no revisions for aseptic loosening of stem or cup. The combination of Exeter cemented stem with a dual mobility bearing from a different manufacturer results in acceptable short-term outcomes in terms of hip stability, revision rates and patient-reported measures.

Incidence of thyroid dysfunction in children after HSCT with reduced intensity conditioning (RIC) or myeloablative conditioning (MAC).

We have previously demonstrated a 11% incidence of post-transplant de novo thyroid disease, even with a radiation-free RIC regimen. Following the enactment of a universal late effects screening program at our institution, we compared the outcomes of 108 pediatric hematopoietic stem cell transplant recipients after a RIC regimen (n = 33) to those after a MAC regimen (n = 75) during the same time period. Overall, 10% of subjects developed thyroid dysfunction after HSCT, with a median follow-up of 669 days. Seven subjects had primary hypothyroidism prior to HSCT. Of the thirty-one subjects who received RIC, one (3.2%) developed a new thyroid disorder, compared to the nine of sixty-nine (13.0%) subjects who received MAC (p = .167). No significant associations were seen with donor type, graft-vs.-host disease, or total body irradiation. Nine of the 10 subjects who developed thyroid disease after transplant were asymptomatic. Continued follow-up of this contemporary cohort will further delineate risk factors for post-transplant-associated thyroid dysfunction and better inform discussions of transplant-associated sequelae.

Long-Term Survival of the Cemented Exeter Universal Stem in Patients 50 Years and Younger: An Update on 130 Hips.

BACKGROUND: There is variable evidence regarding survivorship beyond 20 years of total hip arthroplasties in young patients. We report the long-term results of the Exeter cemented hip system in patients ≤50 years at minimum of 20 years. METHODS: Clinical and radiological outcomes of 130 consecutive total hip arthroplasties in 107 patients aged 50 years or younger at primary operation were reviewed; 77% had a diagnosis other than osteoarthritis. All patients were followed at 5-year intervals, no patients were lost to follow-up, and the status of every implant is known. RESULTS: Mean age at surgery was 41.8 (17-50) years. Mean follow-up was 22.0 (20.0-26.1) years. There were 79 hips surviving, 14 hips (11 patients) deceased, and 37 hips revised. Reasons for revision: 29 hips for aseptic cup loosening (26 stems revised using cement-in-cement, three left in-situ); three stems for femoral osteolysis, two related to acetabular polyethylene wear (14.1 and 17.0 years), one with Gaucher's disease (21.1 years); one broken stem (12.9 years); one cup for instability (4.3 years-stem revised using cement-in-cement); and two hips with infection (8.5 and 23.8 years). There were no cases of aseptic loosening of the Exeter stem. There were no radiologically loose stems although eight patients had radiological evidence of loosening of the cemented cup. Survivorship at 22 years was 74.9% for revision for all causes and 96.3% for revision of the stem for aseptic loosening or lysis. CONCLUSION: The Exeter cemented stem has excellent survivorship at minimum 20 years in young patients. Acetabular component survivorship was less favorable, but the advent of highly cross-linked polyethylene may improve this in the long term.

The Exeter Short Revision Stem for Cement-in-Cement Femoral Revision: A Five to Twelve Year Review.

BACKGROUND: Cement-in-cement femoral revision is a proven technique in revision total hip arthroplasty, with excellent results reported using standard-sized Exeter stems. The Exeter 44/00/125 short revision stem was introduced in 2004 to facilitate cement-in-cement revision. The stem is 25-mm shorter and has a slimmer body than standard stems to facilitate adjustment of depth of insertion and stem version. It is not known if this change in stem size affects its long-term performance. We therefore reviewed the outcome of all Exeter short revision stems used for cement-in-cement revision in our unit, with a minimum of 5 years of follow-up. METHOD: One hundred sixty-six cases were performed between 2004 and 2010. Mean follow-up of surviving patients was 8.1 years (range 5.0-11.7). The fate of all 166 hips were known and included in the survival analysis. RESULTS: Median clinical scores improved significantly. Sixteen hips required re-revision (infection 6, loose cup 3, periprosthetic fracture 3, instability 2, stem fracture with chronic infection 1, and pain 1). Kaplan-Meier survival analysis at 10 years revealed 100% survival for aseptic stem loosening, 96.8% survival for stem failure, and 88.9% survival for all causes. CONCLUSION: The Exeter short revision stem performed as well as standard length stems for cement-in-cement revision in this the largest and longest review of their use. Larger registry-based studies may provide additional information on the performance of this stem.

Not all cemented hips are the same: a register-based (NJR) comparison of taper-slip and composite beam femoral stems.

Background and purpose - No difference in outcome has been demonstrated comparing cemented taper-slip and composite beam designs in short-term randomised trials; we assessed outcome differences using a registry analysis. Patients and methods - All cemented stems with > 100 implantations were identified in the National Joint Registry of England and Wales from April 1, 2003 to September 31, 2013 and categorised as taper-slip or composite beam. Survival analyses using Kaplan-Meier and Cox regression were performed. Results - We identified 292,987 cemented arthroplasties, of which 16% (47,586) were composite beam stems, with taper-slip stems making up the remainder (n = 245,401). There was a statistically significant increased chance of revision in the composite beam group compared with the taper-slip group (1.7% vs 1.3%, p < 0.001) but statistically no significant differences of survival estimates (p = 0.06). When the 2 groups were segregated to delineate the most implanted model in each category, the differences became more profound with the most implanted taper-slip stem (Exeter V40) showing statistically and clinically significant superior 8-year survival: 97.9% compared with 97.6% for all other taper-slip; 97.5% for the most implanted composite beam (Charnley cemented stem); and 97.7% for all other composite beam. Interpretation - There was an increased incidence of revision for composite beam stems. The most implanted taper-slip stem demonstrated significant survival advantage vs. all other stems.

Single Ultra-High-Dose Cholecalciferol to Prevent Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation.

Vitamin D deficiency is prevalent among childhood hematopoietic stem cell transplantation (HSCT) recipients and associated with inferior survival at 100 days after transplantation. Achieving and maintaining therapeutic vitamin D levels in HSCT recipients is extremely challenging in the first 3 to 6 months after transplantation due to poor compliance in the setting of mucositis and the concomitant use of critical transplantation drugs that interfere with vitamin D absorption. We sought to evaluate the safety and efficacy of a single, ultra-high-dose of vitamin D given before childhood HSCT to maintain levels in a therapeutic range during the peritransplantation period. Ten HSCT recipients with pretransplantation 25-OH vitamin D (25OHD) level <50 ng/mL and with no history of hypercalcemia, nephrolithiasis, or pathological fractures were enrolled on this pilot study. A single enteral vitamin D dose (maximum 600,000 IU) was administered to each patient based on weight and pretransplantation vitamin D level before the day of HSCT. Vitamin D levels between 30 and 150 ng/mL were considered therapeutic. All patients received close clinical observation and monitoring of 25OHD levels, calcium, phosphate, parathyroid hormone, urine calcium/creatinine ratio, and n-telopeptide for safety and efficacy assessment. The mean age of the study subjects was 5.8 ± 4.9 years, and the mean pretransplantation 25OHD level was 28.9 ± 13.1 ng/mL. All patients tolerated single, ultra-high-oral dose of vitamin D under direct medical supervision. No other oral vitamin D supplements were administered during the observation window of 8 weeks. Three of 10 patients received 400 IU/day of vitamin D in parenteral nutrition only for 5 days during the study window. A mean peak serum vitamin D level of 80.4 ± 28.6 ng/mL was reached at a median of 9 days after the vitamin D dose. All patients achieved a therapeutic vitamin D level of >30 ng/mL. Mean vitamin D levels were sustained at or above 30 ng/mL during the 8-week observation window. There were no electrolyte abnormalities attributed to the ultra-high-dose of vitamin D. Most patients had mildly elevated urine calcium/creatinine ratios during treatment, but none showed clinical or radiologic signs of nephrocalcinosis or nephrolithiasis. Our findings indicate that single ultra-high-oral dose vitamin D treatment given just before HSCT is safe and well tolerated in the immediate peritransplant period in children. Patients in our study were able to achieve and sustain therapeutic vitamin D levels throughout the critical period during which vitamin D insufficiency is associated with decreased overall survival. Larger prospective studies are needed to address the impact of single ultra-high-dose vitamin D treatment on HSCT outcomes.

An Analysis of Reported Cases of Fracture of the Universal Exeter Femoral Stem Prosthesis.

BACKGROUND: Between 1991 and 2008, approximately 80 cases of fracture (neck or stem) have been reported. This study aimed at determining factors predisposing to implant fracture. METHODS: Clinical, surgical, radiological, and retrieval data were collated. Risk factors associated with fracture were categorized to patient related (weight and activity levels), surgical related (poor medial support, component size, and placement), and anatomic/implant related (head size/offset). RESULTS: Data was available on 60 patients (32 stem and 28 neck fractures). Mean patient age at fracture was similar for both neck and stem fractures (69 years, 67 years, respectively). Also, 77% neck and 52% stem fractures occurred in men. Mean weight was 107 kg in neck and 96.5 kg in stem fractures with 68% neck and 38% stem fractures either obese or morbidly obese. Mean time to fracture was 78 months (range, 36-144 months) for neck and 76 months (range, 2-155 months) for stem fractures. 44#2 and 44#3 were the most common sizes associated with neck fractures. Stem fractures occurred more commonly (84%) in the smaller sizes (35.5 to 44#1). Elongated femoral heads were used in 69% neck and 14% stem fractures. CONCLUSION: Neck fractures were most commonly associated with patient-related (increased weight and activity) and implant-related (use of an elongated femoral head) factors. Stem fractures were most commonly associated with correctable surgical-related causes, predominantly secondary to stem undersizing or inadequate medial support (84%).

Transcatheter aortic valve implantation in the United Kingdom: temporal trends, predictors of outcome, and 6-year follow-up: a report from the UK Transcatheter Aortic Valve Implantation (TAVI) Registry, 2007 to 2012.

BACKGROUND: We assessed trends in the performance of transcatheter aortic valve implantation in the United Kingdom from the first case in 2007 to the end of 2012. We analyzed changes in case mix, complications, outcomes to 6 years, and predictors of mortality. METHODS AND RESULTS: Annual cohorts were examined. Mortality outcomes were analyzed in the 92% of patients from England and Wales for whom independent mortality tracking was available. A total of 3980 transcatheter aortic valve implantation procedures were performed. In successive years, there was an increase in frequency of impaired left ventricular function, but there was no change in Logistic EuroSCORE. Overall 30-day mortality was 6.3%; it was highest in the first cohort (2007-2008), after which there were no further significant changes. One-year survival was 81.7%, falling to 37.3% at 6 years. Discharge by day 5 rose from 16.7% in 2007 and 2008 to 28% in 2012. The only multivariate preprocedural predictor of 30-day mortality was Logistic EuroSCORE ≥40. During long-term follow-up, multivariate predictors of mortality were preprocedural atrial fibrillation, chronic obstructive pulmonary disease, creatinine >200 µmol/L, diabetes mellitus, and coronary artery disease. The strongest independent procedural predictor of long-term mortality was periprocedural stroke (hazard ratio=3.00; P<0.0001). Nonfemoral access and postprocedural aortic regurgitation were also significant predictors of adverse outcome. CONCLUSIONS: We analyzed transcatheter aortic valve implantation in an entire country, with follow-up over 6 years. Although clinical profiles of enrolled patients remained unchanged, longer-term outcomes improved, and patients were discharged earlier. Periprocedural stroke, nonfemoral access, and postprocedural aortic regurgitation are predictors of adverse outcome, along with intrinsic patient risk factors.

Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation Patients Despite Both Standard and Aggressive Supplementation.

We recently reported that more than 70% of pediatric and young adult patients had a vitamin D (VD) deficiency at the time of their hematopoietic stem cell transplantation (HSCT). Moreover, VD deficiency was associated with inferior survival at 100 days after transplantation. The goal of the present study was to evaluate the VD requirements needed to maintain an optimal VD level (30 to 60 ng/mL) during the first 3 months after transplantation using real-time VD monitoring and personalized VD supplementation. We examined 2 cohorts in this study: cohort 1, the "preintervention" cohort (n = 35), who were treated according to National Kidney Foundation guidelines for VD therapy, and cohort 2, the "intervention" cohort (n = 25) who were treated with high-dose VD with an aggressive dosage increase in those who remained VD-insufficient. Results from cohort 1 showed that despite aggressive monitoring and VD supplementation, therapeutic vitamin D levels were difficult to achieve and maintain in HSCT recipients during the early post-transplantation period. Only 43% of cohort 1 achieved a therapeutic VD level, leading to our intervention in cohort 2. Outcomes improved in cohort 2, but still only 64% of cohort 2 patients achieved a therapeutic VD level despite receiving >200 IU/kg/day of VD enterally. The median VD level in patients who did achieve sufficient levels was 40 ng/mL, with only 1 patient in each cohort achieving a supratherapeutic but nontoxic level. These data indicate that standard guidelines for VD replacement are inadequate in HSCT recipients, and further work is needed to define more appropriate dosing in this clinical setting.

Vitamin D Deficiency and Survival in Children after Hematopoietic Stem Cell Transplant.

Vitamin D has endocrine function as a key regulator of calcium absorption and bone homeostasis and also has intracrine function as an immunomodulator. Vitamin D deficiency before hematopoietic stem cell transplantation (HSCT) has been variably associated with higher risks of graft-versus-host disease (GVHD) and mortality. Children are at particular risk of growth impairment and bony abnormalities in the face of prolonged deficiency. There are few longitudinal studies of vitamin D deficient children receiving HSCT, and the prevalence and consequences of vitamin D deficiency 100 days after transplant has been poorly studied. Serum samples from 134 consecutive HSCT patients prospectively enrolled into an HSCT sample repository were tested for 25-hydroxy (25 OH) vitamin D levels before starting HSCT (baseline) and at 100 days after transplantation. Ninety-four of 134 patients (70%) had a vitamin D level < 30 ng/mL before HSCT, despite supplemental therapy in 16% of subjects. Post-transplant samples were available in 129 patients who survived to day 100 post-transplant. Vitamin D deficiency persisted in 66 of 87 patients (76%) who were already deficient before HSCT. Moreover, 24 patients with normal vitamin D levels before HSCT were vitamin D deficient by day 100. Overall, 68% of patients were vitamin D deficient (<30 ng/mL) at day 100, and one third of these cases had severe vitamin D deficiency (<20 ng/mL). Low vitamin D levels before HSCT were not associated with subsequent acute or chronic GVHD, contrary to some prior reports. However, severe vitamin D deficiency (<20 ng/mL) at 100 days post-HSCT was associated with decreased overall survival after transplantation (P = .044, 1-year rate of overall survival: 70% versus 84.1%). We conclude that all pediatric transplant recipients should be screened for vitamin D deficiency before HSCT and at day 100 post-transplant and that aggressive supplementation is needed to maintain sufficient levels.

Growth hormone improves short stature in children with Diamond-Blackfan anemia.

BACKGROUND: Diamond-Blackfan anemia (DBA), an inherited marrow failure syndrome, has severe hypoplastic anemia in infancy and association with aplastic anemia, MDS/leukemia, and other malignancies. Short stature is present in most patients. Isolated cases have demonstrated improved growth on growth hormone (GH) therapy. PROCEDURES: GH treatment data were obtained from 19 children with DBA (6 at our site and 13 from Genentech). Control data from 44 non-GH treated children were provided by Diamond Blackfan Anemia Registry. Annual growth velocity (GV) and height-for-age Z-scores (HAZ) were compared between groups and for up to 4y of GH treatment. RESULTS: Constructed DBA-specific male and female height-for-age charts for non-GH treated patients revealed short stature compared to CDC norms. GH-treated patients had significantly lower HAZ prior to treatment initiation compared to non-GH-treated controls. Among GH-treated patients, GV significantly improved in the first two years relative to pre-treatment. HAZ significantly improved in each of 4y of GH therapy compared to baseline. After 2y of therapy, HAZ for GH-treated patients were not significantly different from controls, demonstrating successful catch-up growth. CONCLUSIONS: GH treatment in children with DBA improves both GV and HAZ during treatment sustained for up to 4y. Very short children with DBA can be treated successfully with GH to restore stature to levels comparable to less affected patients. DBA height charts are useful tools for assessing age-specific growth in this typically short population. Careful consideration of individualized benefit of GH therapy versus risk is important in view of long-term underlying ∼5% malignancy risk in DBA.

Mortality following hip arthroplasty--inappropriate use of National Joint Registry (NJR) data.

Mortality following hip arthroplasty is affected by a large number of confounding variables each of which must be considered to enable valid interpretation. Relevant variables available from the 2011 NJR data set were included in the Cox model. Mortality rates in hip arthroplasty patients were lower than in the age-matched population across all hip types. Age at surgery, ASA grade, diagnosis, gender, provider type, hip type and lead surgeon grade all had a significant effect on mortality. Schemper's statistic showed that only 18.98% of the variation in mortality was explained by the variables available in the NJR data set. It is inappropriate to use NJR data to study an outcome affected by a multitude of confounding variables when these cannot be adequately accounted for in the available data set.

Management of periprosthetic joint infection after total hip arthroplasty using a custom made articulating spacer (CUMARS); the Exeter experience.

Periprosthetic joint infection (PJI) after THA is a major complication with an incidence of 1%-3%. We report our experiences with a technique using a custom-made articulating spacer (CUMARS) at the first of two-stage treatment for PJI. This technique uses widely available all-polyethylene acetabular components and the Exeter Universal stem, fixed using antibiotic loaded acrylic cement. Seventy-six hips were treated for PJI using this technique. Performed as the first of a two-stage procedure, good functional results were commonly seen, leading to postponing second stage indefinitely with retention of the CUMARS prosthesis in 34 patients. The CUMARS technique presents an alternative to conventional spacers, using readily available components that are well tolerated, allowing weight bearing and mobility, and achieving comparable eradication rates.

The Exeter-Trident THA with ceramic-on-ceramic-bearings: 10-year outcomes in 275 total hip arthroplasties.

AIMS: This study reports on the Exeter-Trident total hip arthroplasty (THA) using an alumina ceramic-on-ceramic bearing with 10-year clinical and radiographic follow-up. PATIENTS AND METHODS: Between January 2001 and January 2006, 275 THAs were performed. Mean age at surgery was 52.7 (17-86) years, with 84 patients (33.6%) aged <50 years. The primary outcome was all-cause construct survival at minimum 10 years. Secondary outcomes included functional and noise scores. Radiographs were compared between baseline and latest follow-up and assessed for component loosening, migration and lysis. RESULTS: No patient was lost to follow-up. Mean follow-up for surviving patients was 12.5 (9.5-15.6) years. Kaplan-Meier survival for all-cause revision was 94.0% (95% CI, 90.5-97.5) at 14.3 years. 2 patients had a femoral component fracture. All scores improved significantly at latest follow-up. HSS-NQ for 247 hips (90.2%) at mean 9.1 (7.0-14.4) years post implantation showed most hips (93.1%) reported no more than occasional noise. At minimum 5 years, radiolucency around the acetabular component was observed in 2 hips (0.8%), and lysis at the interface in 1 hip (0.4%). On the femoral side, endosteal lysis was observed in 7 hips. CONCLUSIONS: The Exeter-Trident THA with alumina ceramic-on-ceramic bearings performed well in this population. Patients are at low risk of revision in the first decade. However, there is a small risk of stem fracture as a late complication and some patients experience significant noise.

Multifocal Insulinoma as the Unique Presenting Feature of Multiple Endocrine Neoplasia Type 1 in an Adolescent.

INTRODUCTION: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited disorder defined by the presence of two of the following endocrinopathies: primary hyperparathyroidism, anterior pituitary tumors, and duodenopancreatic neuroendocrine tumors (NETs). NETs, which can secrete hormones including insulin, gastrin, and glucagon, among others, are common in patients with MEN1 and are a major cause of morbidity and premature death. NETs are more common later in life, with very few cases described in children. Here, we describe a unique case of an adolescent with multifocal pancreatic NETs as the single presenting feature of MEN1. CASE PRESENTATION: A 13-year-old healthy male presented with severe weakness, altered mental status, and syncope in the setting of a venous blood glucose (BG) of 36 mg/dL. Workup showed an elevated insulin level (14 µIU/mL) when BG was 39 mg/dL with positive response to glucagon, concerning for hyperinsulinism. Diazoxide and chlorothiazide were started but not well tolerated secondary to emesis. Three suspected NETs were identified by magnetic resonance imaging and 68-Ga DOTATATE PET-CT imaging, including the largest, a 2.1 cm mass in the pancreatic head. A fourth mass in the pancreatic tail was identified via intraoperative ultrasound. All lesions were successfully enucleated and excised, and glucose levels normalized off diazoxide by post-op day 2. While the primary lesion stained for insulin and somatostatin by immunofluorescence (IF), consistent with his clinical presentation, the additional tumors expressed glucagon, somatostatin, pancreatic polypeptide, and chromogranin A but were negative for insulin. Genetic testing confirmed a pathogenic heterozygous mutation in MEN1 (c.969C>A, p.Tyr323). He had no other signs of MEN-associated comorbidities on screening. DISCUSSION/CONCLUSION: This case demonstrates that young patients with MEN1 can present with multifocal NETs. These NETs may have polyhormonal expression patterns despite a clinical presentation consistent with one primary hormone. Our patient had clinical symptoms and laboratory evaluation consistent with an insulinoma but was found to have four NETs, each with different IF staining patterns. Advanced preoperative and intraoperative imaging is important to identify and treat all present NETs. Moreover, serum hormone levels pre- and posttreatment could help evaluate whether NETs are actively secreting hormones into the bloodstream or simply expressing them within the pancreas. Finally, this case highlights the importance of genetic testing for MEN1 in all young patients with insulinomas.

Revision of metal-on-metal hip replacements with dual-mobility bearings and acetabular component retention.

Aims: In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods: Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results: In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion: In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications.