Do preoperative factors and implant design features influence humeral stem extraction efforts?

BACKGROUND: Variations in humeral component designs in hemiarthroplasty and anatomic total shoulder arthroplasty cases can impact the degree of difficulty during a revision surgery that necessitates the removal of the humeral stem. However, no metric exists to define stem extraction effort nor to identify associated factors that contribute to extraction difficulty. The purpose of this study is to describe a method to quantify stem extraction difficulty and to define features that will impact the effort during stem removal. METHODS: This was a retrospective review of 58 patients undergoing revision of hemiarthroplasty or anatomic total shoulder arthroplasty requiring stem extraction. Each included patient had existing preoperative radiographic examination, an intraoperative video of the stem removal process, and explants available for analysis by 3 surgeons. The following factors were assessed for the impact on extraction difficulty: (1) preoperative features such as cement use, fill of proximal humerus, and stem design features; (2) intraoperative data on extraction time and bone removal; and (3) postoperative findings related to extraction artifacts (EAs). A scoring system was established to distinguish easy (Easy group) and difficult (Difficult group) stem removal cases and further used to identify the features that may affect intraoperative difficulty of stem removal. RESULTS: The Difficult group accounted for 26% (15/58) of the study population with an 18-minute average stem extraction time, average EA count of 69, and 35 mm of bone removed. The Easy group accounted for 74% (43/58) of patients, with a 4-minute average extraction time, average EA count of 23, and 10 mm of bone removed. Logistic regression model was able to correctly classify 82% of the cases, explaining 26.7% of the variance in humeral stem removal with cement and proximal coating variables. The likelihood of cemented stem removal being difficult is 5 times greater compared to an uncemented stem, and having proximal coating doubles the likelihood of a difficult stem removal compared to cases with no coating. CONCLUSIONS: Quantifying stem extraction difficulty is possible with intraoperative video as well as explant analysis. Preoperative features of the fixation type and specific features of stem design such as proximal coating will impact difficulty of stem extraction.

Improved mechanical fixation of an all-polyethylene glenoid reduces postoperative radiolucent lines.

BACKGROUND: The rationale for advances in implant design is to improve performance in comparison to their predecessors. The purpose of this study was to compare a newer, self-pressurizing peripheral peg glenoid to a traditional polyethylene pegged glenoid through biomechanical evaluation and a retrospective radiographic and clinical review. METHODS: Three testing conditions (uncemented, partially cemented, and fully cemented) were chosen to assess the 2 component designs in a foam block model. The number of hammer hits to seat the component, amount of time to seat the component, and resistance-to-seat were collected. The implants were then cyclically loaded following ASTM F2028-17 testing standard. Clinically, postoperative radiographs of patients with a self-pressurized glenoid component (n = 225 patients) and traditional glenoid component (n = 206 patients) were evaluated for radiolucent lines and glenoid seating at various timepoints. Clinical outcomes (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, and visual analog scale pain scores) and complications were recorded. The presence of radiolucent lines at the bone-cement interface was evaluated using the Modified Franklin Grade and the Lazarus grade. RESULTS: The self-pressurizing glenoid design required significantly more hammer hits than traditional glenoid designs in all groups tested (P < .029). Moreover, the self-pressurizing design had significantly more resistance-to-seat than traditional components in both the uncemented and partially cemented group (P < .002). No difference in resistance-to-seat was found between designs in the fully cemented group. The uncemented and partially cemented groups did not survive the full 50,000 cycles; however the self-pressurizing design had significantly less motion than the traditional design (P < .001). No differences between component designs were found in the fully cemented group at 50,000 cycles. The self-pressurizing glenoid component had 0.005% radiographic radiolucent lines, and the traditional glenoid component had 45% radiographic radiolucent lines, with 38% of the radiolucencies in the traditional glenoid component group being defined as grade E. There were no progressive radiolucencies, differences in clinical outcomes, or complications at 2 years postoperatively. CONCLUSION: In the fully cemented condition, the 2 component designs had comparable performance; however, the differences in designs could be better observed in the uncemented group. The self-pressurizing all-polyethylene design studied has superior biomechanical stability. Clinically, the improved stability of the glenoid component correlated with a reduction of radiolucent lines and will likely lead to a reduction in glenoid component loosening.

Calcium Phosphate Bone Void Filler Increases Threaded Suture Anchor Pullout Strength: A Biomechanical Study.

PURPOSE: To compare the response to cyclical loading and ultimate pull-out strength of threaded suture anchor with and without calcium phosphate bone void filler augmentation in a polyurethane foam block model and in vitro proximal humerus cadaveric model. METHODS: This controlled biomechanical study consisted of 2 parts: (1) preliminary polyurethane foam block model, and (2) in vitro cadaveric humeri model. The preliminary foam block model intended to mimic osteoporotic bone using a 0.12 g/mL foam material. Half of the foam block models were first filled with injectable calcium phosphate bone substitute material (CP-BSM), whereas the other half were not augmented with CP-BSM. Each specimen was then instrumented with a threaded suture anchor. The same technique and process was performed in a matched cadaveric humeri model. Testing then consisted of a stepwise, increasing axial load protocol for a total of 40 cycles. If the anchor remained intact after cyclic loading, the repair was loaded to failure. The number of completed cycles, failure load, and failure modes were compared between groups. RESULTS: Average pull-out strength for suture anchor with CP-BSM in the osteoporotic foam block model was significantly higher at 332.68 N ± 47.61 compared with the average pull-out strength of suture anchor without CP-BSM at 144.38 N ± 14.58 (P = .005). In the matched cadaveric humeri model, average pull-out strength for suture anchor with CP-BSM was significantly higher at 274.07 N ± 102.07 compared with the average pull-out strength of suture anchor without CP-BSM at 138.53 N ± 109.87 (P = .029). CONCLUSIONS: In this time zero, biomechanical study, augmentation of osteoporotic foam block and cadaveric bone with calcium phosphate bone substitute material significantly increases pull-out strength of threaded suture anchors. CLINICAL RELEVANCE: Considering concerns about suture anchor pull-out from osteoporotic bone, augmentation with calcium phosphate bone substitute material increases load to failure resistance.

Orocraniofacial findings and dental management of a pediatric patient with Dubowitz syndrome.

Dubowitz syndrome is a rare genetic condition characterized by microcephaly, dysmorphic facial features and delayed general growth. It is transmitted through autosomal recessive inheritance. The purpose of this report is to describe the oral, craniofacial and systemic characteristics of a 7-year 11-month-old boy with Dubowitz syndrome and the dental management provided. The pediatric dentist should possess the ability to recognize this rare alteration, to provide dental treatment and to refer for the necessary medical and multidisciplinary treatment.

Orofacial findings and dental management of Williams-Beuren syndrome.

Williams-Beuren syndrome is a rare congenital disorder involving the cardiovascular system, mental retardation, distinctive facial features, and tooth anomalies. The aim of the present report is to show a 10-year-old girl with Williams-Beuren syndrome, her general and orofacial clinical characteristics and the dental management.

Cytomegalovirus excretion in children attending day-care centers.

BACKGROUND: Healthy children attending day-care centers (DCC) may excrete cytomegalovirus (CMV) frequently. Mothers of children excreting CMV are at higher risk for acquiring this infection than mothers of children not excreting CMV. Despite the increased attendance to DCC by children there is a lack of information regarding CMV infection in Mexico. METHODS: Prospective determination of CMV excretion in saliva of children attending public and private DCC. Three saliva samples were collected during a 2-month follow-up period from participating children and the presence of CMV was determined by viral culture. Demographic features of children and DCC type were taken into account when comparing children with and without CMV excretion. RESULTS: One hundred fifty-two children participated in the study (84 from public and 68 from private DCC). Overall, 17 (11.2%) children excreted CMV during the study period. Excretion rates varied between DCC from 3.1 to 31.3%. Children from private DCC were as likely to excrete CMV as children from public DCC. There were no demographic or clinical features of children associated with viral excretion. CONCLUSIONS: CMV was excreted on an average of 11.2% children attending DCC. The type of DCC or other demographic features were not associated with the likelihood of CMV excretion. CMV seronegative mothers of children who attend DCC need to be aware of the possibility of CMV acquisition and transmission in DCC.

Recurrent lingual abscess.

Lingual abscess is an unusual condition but it may become a life-threatening entity. It presents as a very painful swelling of the tongue that, in its early stages, can be managed by antibiotic treatment. When the airway is obstructed, drainage is required by an open incision or aspiration with a large bore needle. We report a case who consulted on two occasions for a lingual abscess, which opened spontaneously. Due to the rarity of recurrent cases, the causes, diagnosis and treatments will be reviewed.

Intraoral findings and other developmental conditions in Mexican neonates.

PURPOSE: The objective of this study was to investigate the prevalence of intraoral findings and other minor developmental malformations in newborns from San Luis Potosi, Mexico. METHODS: Study subjects were neonates born in San Luis Potosi Morones Prieto Hospital between September 1989 and February 1990. All subjects are examined at this hospital within 20 hours of birth. Premature babies or those requiring intensive care were excluded. Examinations are performed by a team consisting of a geneticist, an oral pathologist, 2 dentists, and an oral surgeon using mirrors, tongue blades, and a flashlight. RESULTS: The team examined 2,182 neonates and found a frequency of 99% for congenital oral cysts, 2% for natal teeth, 11% for ankyloglossia, 8% for commissural lip pits, and 54% for congenital vascular malformations. The male/female ratios for ankyloglossia and natal teeth were 1.5:1 and 1:2.3, respectively. CONCLUSIONS: Babies born at the same hospital demonstrated a high rate of oral cysts, natal teeth, ankyloglossia, and commissural lip pits.

Manifestaciones orales y manejo de un paciente pediátrico con esclerodermia localizada: revisión de literatura y reporte de un caso / Oral manifestations and management of localized scleroderma in childhood: Review of the literature and case report

La esclerodermia es una rara enfermedad que afecta los tejidos de origen mesenquimatoso y ectodérmico. Se caracteriza por la aparición de alteraciones inflamatorias y vasculares, además de esclerosis en la piel y órganos de los sistemas respiratorio, cardiovascular y gastrointestinal. El propósito del presente reporte es describir el caso de una niña de 4 años con esclerodermia localizada, sus manifestaciones clínicas, datos epidemiológicos y sugerencias de manejo odontológico de los pacientes pediátricos con esta rara enfermedad.

Scleroderma is a rare disorder that affects mesenchymal and ectodermal tissues. It is characterized of vascular and inflammatory alterations and sclerosis in the skin and organs of respiratory, cardiovascular and gastrointestinal systems. The purpose of this report is to describe the case of a 4 year old girl with localized scleroderma, its clinical manifestations, epidemiological data and recommendations of dental management for the pediatric patients with this rare disease.