What Is the Standard Volume to Increase a Cup Size for Breast Augmentation Surgery? A Novel Three-Dimensional Computed Tomographic Approach.

BACKGROUND: Breast augmentation surgery poses many challenges, and meeting the patient's expectations is one of the most important. Previous reports equate 100 cc to a one-cup-size increase; however, no studies have confirmed this between commercially available bras. The aim of this study was to identify the volume increase between cup sizes across different brands and the relationship with implant selection. METHODS: Five bra cup sizes from three different companies were analyzed for their volume capacity. Three methods were used to calculate the volume of the bras: (1) linear measurements; (2) volume measurement by means of water displacement; and (3) volume calculation after three-dimensional reconstruction of serial radiographic data (computed tomography). The clinical arm consisted of 79 patients who underwent breast augmentation surgery from February 1, 2014, to June 30, 2016. Answers from a short questionnaire in combination with the implant volume were analyzed. RESULTS: Across all three brands, the interval volume increase varied between sizes, but not all were above 100 cc. There was some variation in the volume capacity of the same cup size among the different brands. The average incremental increase in bra cup size across all three brands in the laboratory arm was 135 cc. The mean volume increase per cup size was 138.23 cc in the clinical arm. CONCLUSIONS: This article confirms that there is no standardization within the bra manufacturing industry. On the basis of this study, patients should be advised that 130 to 150 cc equates to a one-cup-size increase. Bras with narrower band widths need 130 cc and wider band widths require 150 cc to increase one cup size.

Analysis of the cephalometric changes in the first 3 months after spring-assisted cranioplasty for scaphocephaly.

BACKGROUND: Spring-assisted cranioplasty (SAC) has become an accepted treatment for patients with sagittal craniosynostosis; however, the early effects of springs on skull dimensions have never been assessed with objective measurements in the literature. The present study evaluated the changes in skull dimensions and intracranial volume (ICV) during the first 3 months after SAC for sagittal synostosis. METHODS: Sixteen patients with sagittal synostosis underwent SAC. The cephalic index (CI) and the distance between the spring foot plates were chronologically measured until spring removal at 3 months. Pre- and post-treatment CT scans available for 6 patients were used to assess changes in head shape. Thirteen patients underwent objective aesthetic assessment using pre- and post-operative photographs. Statistical analysis was performed using the linear mixed model for chronological data, t-test statistics for normative data comparisons and Wilcoxon's signed rank test for non-parametric data. RESULTS: For scaphocephalic patients, pre-operative and post-operative CIs were 0.70 and 0.74 (p = 0.001), respectively. Cranial widening towards normative values was observed (p = 0.0005). A continuous expansion in the distance between the spring foot plates was observed over the treatment period. Frontal and occipital angles were not affected by SAC despite apparent clinical improvements in frontal bossing and occipital prominence. CT analysis demonstrated relative reduction in the anterior cranial volume (p = 0.01) and relative expansion of the superior occipital volume (p = 0.03). CONCLUSIONS: Spring expansion was most marked in the hours following spring insertion. The expansion rate reduced to the minimum by day 1 post-operatively. Clinical benefits of SAC resulted from an increase in the bi-temporal width that camouflaged the frontal bossing. Improvement in occipital prominence was due to superior occipital volume expansion, allowing the occiput to remodel to a more rounded shape.

The histological and elemental characterisation of corrosion particles from taper junctions.

OBJECTIVES: This study aimed to characterise and qualitatively grade the severity of the corrosion particles released into the hip joint following taper corrosion. METHODS: The 26 cases examined were CoC/ABG Modular (n = 13) and ASR/SROM (n = 13). Blood serum metal ion levels were collected before and after revision surgery. The haematoxylin and eosin tissue sections were graded on the presence of fibrin exudates, necrosis, inflammatory cells and corrosion products. The corrosion products were identified based on visible observation and graded on abundance. Two independent observers blinded to the clinical patient findings scored all cases. Elemental analysis was performed on corrosion products within tissue sections. X-Ray diffraction was used to identify crystalline structures present in taper debris. RESULTS: The CoC/ABG Modular patients had a mean age of 64.6 years (49.4 to 76.5) and ASR/SROM patients had a mean age of 58.2 years (33.3 to 85.6). The mean time in situ for CoC/ABG was 4.9 years (2 to 6.4) and ASR/SROM was 6.1 years (2.5 to 8.1). The blood serum metal ion concentrations reduced following revision surgery with the exception of Cr levels within CoC/ABG. The grading of tissue sections showed that the macrophage response and metal debris were significantly higher for the ASR/SROM patients (p < 0.001). The brown/red particles were significantly higher for ASR/SROM (p < 0.001). The taper debris contained traces of titanium oxide, chromium oxide and aluminium nitride. CONCLUSION: This study characterised and qualitatively graded the severity of the corrosion particles released into the hip joint from tapers that had corrosion damage.Cite this article: S. Munir, R. A. Oliver, B. Zicat, W. L. Walter, W. K. Walter, W. R. Walsh. The histological and elemental characterisation of corrosion particles from taper junctions. Bone Joint Res 2016;5:370-378. DOI: 10.1302/2046-3758.59.2000507.

Looped suture properties: implications for multistranded flexor tendon repair.

Multiple-strand repair techniques are commonly used to repair cut flexor tendons to achieve initial biomechanical strength. Looped sutures achieve multiple strands with fewer passes and less technical complexity. Their biomechanical performance in comparison with an equivalent repair using a single-stranded suture is uncertain. This study examined the mechanical properties of double-stranded loops of 3-0 and 4-0 braided polyester (Ticron) and polypropylene monofilament (Prolene). Double loops were generally less than twice the strength of a single loop. Ticron and Prolene had the same strengths, but Ticron was stiffer. The 4-0 double loops had significantly higher stiffness than 3-0 single loops. Increasing the size of sutures had a larger relative effect on strength than using a double-stranded suture. However, a double-strand loop had a larger effect on increasing stiffness than using a single suture of a larger equivalent size. Looped suture repairs should be compared with standard techniques using a thicker single suture.

A nitinol "U-Clip" versus sutured arteriovenous anastomosis: local tissue response and intimal hyperplasia development in a sheep model.

OBJECTIVES: This study sought to compare the local tissue response and subsequent volume of intimal hyperplasia (IH) that develops throughout the maturation of an arteriovenous fistula created using continuous/interrupted polypropylene with that of a novel, metal-alloy, penetrating anastomotic clip device. MATERIALS AND METHODS: Forty-six fistulae were created in 23 sheep under a paired design using the nitinol U-Clip (n = 23) in one hind limb and continuous (n = 20) or interrupted (n = 3) polypropylene suture for the other. Animals were killed at 4 (n = 3), 14 (n = 3), 28 (n = 10), 42 (n = 3), and 180 (n = 4) days. Histological sections were evaluated for quantitative histology and immunohistochemistry. RESULTS: Compared with continuous polypropylene, U-Clip specimens demonstrated less intima-media area per unit length (IMA/L), proliferating cells, and tissue necrosis at all time points (MANOVA, F = 9.8-24.1, all p ≤ .005; observed power >82%). Specifically, values of IMA/L were reduced by 5% (p = .97), 37% (p = .02), 33% (p < .01), 9% (p = .42), and 14% (p = .22) at the time points of 4, 14, 28, 42, and 180 days respectively. Proliferating cells were reduced by 75% (p < .01), 72% (p = .03), 76% (p = .03), 27% (p = .31), and 60% (p = .01) and tissue necrosis by 67% (p < .01), 58% (p = .02), 40% (p = .33), 21% (p = .43), 77% (p = .11). In a 28-day comparison between U-Clip and interrupted polypropylene the U-Clip group demonstrated a 4% (p = .65) reduction in IMA/L, 74% (p < .01) in proliferating cells and 49% (p < .05) in tissue necrosis. CONCLUSIONS: These results provide evidence of reduced local tissue necrosis, proliferating cells, and IH, favouring arteriovenous fistulae created using the U-Clip anastomotic device over conventional polypropylene suture techniques most evident over the first 4 weeks.

Performance of a knotless four-strand flexor tendon repair with a unidirectional barbed suture device: a dynamic ex vivo comparison.

With increased numbers of reports using barbed sutures for tendon repairs we felt the need to design a specific tendon repair method to draw the best utility from these materials. We split 30 sheep deep flexor tendons in two groups of 15 tendons. One group was repaired with a new four-strand barbed suture repair method without knot. The other group was repaired with a conventional four-strand cross-locked cruciate repair method (Adelaide repair) with knot. Dynamic testing (3-30 N for 250 cycles) and additional static pull to failure was performed to investigate gap formation and final failure forces. The barbed suture repair group showed higher resistance to gap formation throughout the test. Additionally final failure force was higher for the barbed suture group compared with the conventional repair group. When used appropriately, barbed suture materials could be beneficial to use in tendon surgery, especially with regard to early loading of the repair site and gap formation.

Poor histological healing of a femoral fracture following 12 months of oestrogen deficiency in rats.

SUMMARY: Fractures in post-menopausal osteoporosis cause significant morbidity; however, animal models for post-menopausal fracture healing lack the effect of ageing. Therefore, we developed a model using aged animals with chronic oestrogen deficiency, which demonstrates inferior fracture repair (decreased healing histologically, bone mineral density and content and strength). This novel model may help develop molecular strategies for osteoporotic fracture repair. INTRODUCTION: The femur is susceptible to damage by both systemic conditions such as osteoporosis and locally by traumatic injury. The capacity for fracture repair decreases with age, while the risk of fracture increases. As studies of osteoporotic fracture healing in rats traditionally use a period of 3 months or less of oestrogen deficiency prior to fracturing, we aimed to establish a osteoporosis model in rats with chronic oestrogen deficiency by 12 months to better mimic human female osteoporosis. METHODS: Seventy female Sprague-Dawley rats (10 weeks old) were ovariectomised or sham operated and housed for 12 months. The right femur was fractured by way of an open osteotomy and fixed with an intramedullary Kirschner wire. Animals were sacrificed at 1, 3 and 6 weeks for radiography, dual-energy X-ray absorptiometry, tensile testing and histology. RESULTS: Bone mineral density and bone mineral content were lower by 60 and 63 %, respectively, (p < 0.05) in the bilaterally ovariectomized (OVX) groups than those in the sham groups at 6 weeks in the right fractured femurs. Maximum breaking force of the OVX group was lower than that of the sham group, with the greatest difference seen at 6 weeks following osteotomy. Histologically, the OVX groups demonstrated a delay in cellular differentiation within the fracture callus and the presence of bone resorption. The sham animals had a superior histological healing pattern with an Allen score of 4 at 6 weeks compared to a score of 1 for the OVX groups (p < 0.01). CONCLUSIONS: Long-term ovariectomy has a deleterious effect on fracture healing in a rodent model.

Biomechanical assessment of a novel tendon junction.

The Pulvertaft weave has been the standard tendon junction technique used both in tendon transfers and tendon grafts. A limitation of this repair is the sequential failure of stabilizing sutures, rather than the tendon. A novel loop weave is described and compared with the Pulvertaft weave in biomechanical performance. Ovine deep flexor and extensor tendons were used to simulate Pulvertaft or loop weaves (n = 11) for tensile testing. The Pulvertaft weaves failed at the stabilizing sutures, whereas the loop weaves repairs failed by longitudinal splitting of the motor tendon. The loop weave demonstrated significantly higher mean initial failure and ultimate strengths. Tensile loads required to elongate the loop weave by 4, 6, and 8 mm were significantly higher, while more displacement was associated with the Pulvertaft repair under the application of 50, 75, and 100 N tensile loads. This study demonstrates favourable biomechanical characteristics of the new loop weave technique.

Wear in alumina-on-alumina ceramic total hip replacements: a retrieval analysis of edge loading.

We analysed 54 alumina ceramic-on-ceramic bearings from total hip replacements retrieved at one centre after a mean duration of 3.5 years (0.2 to 10.6) in situ. These implants were obtained from 54 patients (16 men and 38 women) with a mean age of 67 years (33 to 88) who underwent revision for a variety of reasons. Posterior edge loading was found in the majority of these retrievals (32 out of 54). Anterosuperior edge loading occurred less often but produced a higher rate of wear. Stripe wear on the femoral heads had a median volumetric wear rate of 0.2 mm(3)/year (0 to 7.2). The wear volume on the femoral heads corresponded to the width of edge wear on the matching liner. Anteversion of the acetabular component was found to be a more important determinant than inclination for wear in ceramic bearings. Posterior edge loading may be considered to be a normal occurrence in ceramic-on-ceramic bearings, with minimal clinical consequences. Edge loading should be defined as either anterosuperior or posterior, as each edge loading mechanism may result in different clinical implications.

An arteriovenous fistula model of intimal hyperplasia for evaluation of a nitinol U-Clip anastomosis.

OBJECTIVES: The aim of this study was to create an ovine arteriovenous fistula (AVF) model which would closely replicate a human forearm fistula and use this to quantify the degree of intimal hyperplasia in those created with the U-Clip compared to a conventional sutured anastomosis. MATERIALS AND METHODS: Twenty AVFs were created in 10 Border Leicester-Merino sheep between the superficial femoral artery and vein of each hind limb. On one side the U-Clip and on the other a continuous polypropylene suture was used to perform the anastomosis. The animals were sacrificed at 2 (n = 3), 4 (n = 4), 6 (n = 3) weeks and histological slices were taken of each AVF in cross section to determine the intimal media area per unit length (IMA/L). RESULTS: Intimal hyperplasia (IH) was observed at all time points with one AVF found occluded with thrombus at the time of harvest. The IMA/L was significantly lower in the U-Clip groups by 24% at 2 weeks, 32% at 4 weeks and 23% at 6 weeks (Two-way ANOVA, p = 0.019, observed power = 0.825, time or side p ≥ 0.766, type p = 0.001; Paired t-test, p < 0.001 between matched anastomotic types). Time taken to perform the anastomosis was similar between the two anastomotic techniques (Polypropylene 14(8-18) vs. U-Clip 15.3(11-23) min; p = 0.47). CONCLUSION: This ovine AVF model results in IH similar to that seen in a human AVF. The IH that occurs with the U-Clip is less than that of continuous polypropylene suture.

Intraoperative patellar kinematics following resection of the central one-third of the patellar tendon in the ovine stifle joint.

OBJECTIVES: The bone-patellar tendon-bone complex is routinely harvested for anterior cruciate ligament reconstruction in humans. Patella infera may ensue. However, the contribution from resection of the central one-third of the patellar tendon (PT) to potentially altered patellofemoral kinematics, in addition to those induced by a positional shift of the patella, are yet to be distinguished. Objectives of this study were to characterize changes in intraoperative patellar kinematics and PT length in nine sheep immediately following unilateral resection of the central one-third PT, and again at six, 12 and 24 weeks postoperatively. METHODS: Following implantation of bone-screws into the patella and tibia, electromagnetic receivers were anchored to these, and then passively-induced, unloaded patellar kinematics were captured. Patellar kinematics were referenced to the tibial coordinate frame and analysed using non-parametric tests (Wilcoxon Signed Rank Test). RESULTS: Resection alone did cause significant alteration in kinematics at the time of surgery (p <0.05). Postoperatively, a mean increase in PT length of 2.6 mm was detected in the operated stifles, reflected partly as a net 2.8 mm proximal patellar shift (p <0.001). This was accompanied by a mean net six degree medial shift in the patellar tilt pattern (p <0.001). Significant changes to patellar spin in the latter parts of flexion were also observed (p <0.005). Kinematic and length changes did not recover up to 24 weeks postoperatively. CLINICAL SIGNIFICANCE: The data obtained in this study suggests that both the patellar height and integrity of the PT are important determinants of patellar kinematics in the ovine stifle joint.

Lunate trabecular structure: a radiographic cadaver study of risk factors for Kienböck's disease [corrected].

The aetiology of Kienböck's disease is unknown. Ulnar variance and lunate shape are possible mechanical risk factors. This study assessed the trabecular structure in 29 cadaveric lunates using microCT and correlated this with ulnar variance and lunate shape on plain radiographs and with bone density assessed using conventional CT. The bony trabeculae within the lunate were shown to run almost perpendicular to the proximal and distal joint surfaces in the coronal plane; these trabeculae met the subchondral bone at an angle between 72-102 degrees. In lunates whose proximal and distal articular surfaces are not parallel, the trabecular orientation may be less able to resist compressive forces and more susceptible to fracture.

3-Fluted orthopaedic drills exhibit superior bending stiffness to their 2-fluted rivals: clinical implications for targeting ability and the incidence of drill-bit failure.

Non-perpendicular drilling of bone is commonplace in orthopaedic surgery. In the absence of drill-jigs and guides, the drill-tip is prone to skiving along the bone. Skiving can alter the position of the intended hole or result in damage to surrounding tissues. We hypothesised that the acute point-angle and increased flexural rigidity of 3-fluted drills - in certain clinical scenarios - can increase a surgeons' ability to accurately position a hole. This study examined differences in drill-tip geometry (point-angle) and mechanical properties (flexural rigidity) between 2.8mm diameter 2-fluted and 3-fluted surgical drills. Our results show that the 3-fluted design offers a significant improvement over the 2-fluted design not only in terms of accuracy; at 15 degrees and 30 degrees approach angles the 3-fluted drill skived significantly less than the 2-fluted drill in the hands of our surgeon, but also in the range of permissible approach angles; the 3-fluted drill was able to drill at a 45 degrees approach angle with skiving equivalent to that experienced by the 2-fluted drill at 15 degrees . Mechanical testing showed that bending stiffness (N/mm) of the 3-fluted drill (9.5+/-2.1N/mm) is more than double that of the 2-fluted drill (3.5+/-0.6N/mm) during operation. Computer modeling of the drills supported this finding and demonstrated that bending stiffness (I X) for the 2-fluted drill varies dynamically during operation whilst remaining constant for the 3-fluted drill. Our study confirms a correlation between mechanical properties, point-geometry and targeting capability for surgical drills. Increased I X of 3-fluted drills may account for the clinical prevalence of rotational bending failure amongst 2-fluted drills.

The anatomically difficult primary total hip replacement: medium- to long-term results using a cementless odular stem.

This prospective study presents the ten-year (5 to 16) clinical and radiological results of 55 primary total hip replacements (THR) using a cementless modular femoral component (S-ROM). All patients had a significant anatomical abnormality which rendered the primary THR difficult. The mean Harris hip score was 36 (12 to 72) pre-operatively, 83 (44 to 100) at five years, and 85 (45 to 99) at ten years. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and short-form (SF)-12 scores were recorded from the year 2000. The mean SF-12 score at five years after surgery was 45.24 (22.74 to 56.58) for the physical component and 54.14 (29.20 to 66.61) for the mental component. By ten years the SF-12 scores were 42.86 (21.59 to 58.95) and 51.03 (33.78 to 61.40), respectively. The mean WOMAC score at five years post-operatively was 25 (0 to 59), and at ten years was 27 (2 to 70). No femoral components were radiologically loose, although five had osteolysis in Gruen zone 1, three had osteolysis in zone 7, and two showed osteolysis in both zones 1 and 7. No osteolysis was observed around or distal to the prosthetic sleeve. No femoral components were revised, although three hips underwent an acetabular revision and two required a liner exchange. At a mean of ten years' follow-up the S-ROM femoral component implanted for an anatomically difficult primary THR has excellent clinical and radiological results.

Influence of surgical preparation on the in-vivo response of osteochondral defects.

Cartilage has an extremely poor capacity to heal, which has lead to intensive research into biomaterials and tissue engineering for the purpose of regenerating cartilage in vivo. Many of these techniques have shown great promise in vitro; however, the results do not always carry across to the in-vivo scenario. Healthy cartilage autografts often do not integrate with the adjacent cartilage, suggesting that cartilage is rarely capable of healing even under ideal conditions. It is hypothesized in this study that the surgical creation of defects in cartilage causes significant damage to the adjacent tissues, leading to further degradation of the cartilage and poor outcome for the repair in general. This study compares the healing response of osteochondral defects created with either a punch or a drill in the weight-bearing region of the sheep knee at 4 and 26 weeks following surgery. The use of a drill to create the defect creates a more aggressive inflammatory response at 4 weeks compared with a punch. However, by 26 weeks, defects created with a punch scored higher on the O'Driscoll cartilage grading scale. Tissue damage at the time of surgery plays an important part in the sequence of events for healing of cartilage defects. This knowledge will help to characterize and refine the ovine model for cartilage regeneration and may have an influence on surgical technique and instrumentation for clinical cartilage repair.

BMP-7 and CBFA1 in allograft bone in vivo bone formation and the influence of gamma-irradiation.

An initial study showed that morselized human bone grafts were osteoconductive and osteoinductive when implanted in nude rat tibial window defects, and 25 kGy of gamma-irradiation significantly reduced those properties. The mechanism of the osteoinductivity and the influence of gamma-irradiation required further investigation. In this study we assessed the paraffin sections of seven morselized human bone grafts implanted into rat tibial defects for 3 weeks after being treated with 0, 15, or 25 kGy gamma-radiation respectively. Osteoclast-like cell counting and protein expressions of bone morphogenetic protein-7 (BMP-7), core binding factor alpha1 (CBFA1), and proliferating cell nuclear antigen (PCNA) were investigated and the positive signals were quantitatively analyzed. More new bone formation was observed in the 0 and 15 kGy groups compared with 25 kGy groups. The newly formed bones were found mainly from the intact cortex into the defects bridged by the implanted grafts. A dense staining of BMP-7 and CBFA1 was noted in the osteoblast-like cells in those areas. The BMP-7 and CBFA1 staining was also seen in the cells surrounding the implanted grafts in the centre areas of the defects in distance from the intact cortex. Quantitative analysis of immunohistochemical staining of the centre areas of the defects showed that gamma-irradiation (15 and 25 kGy) significantly reduced the expression of CBFA1 and BMP-7. In conclusion, morselized human bone grafts may contain some factors, which induced osteoblast lineage differentiation and bone formation and gamma-irradiation damages those bone inducing factors.

Effect of suture material on gap formation and failure in type 1 FDP avulsion repairs in a cadaver model.

BACKGROUND: An in vitro cyclical testing simulating a passive mobilisation protocol was used to compare repair of flexor digitorum profundus tendon with modified-Bunnell two-strand pullout technique using a monofilament (Prolene), braided polyester (Ethibond) and a synthetic polyfilament ensheathed by caprolactan (Supramid) sutures. METHODS: Eighteen fresh-frozen cadaveric fingers were randomly divided into three repair groups (n = 6); modified-Bunnell technique with 3/0 Prolene, Ethibond or Supramid. After repair, specimens were cyclically loaded from 2 to 15N at 5N/s, for a total of 500 cycles. Gap formation at the tendon-bone interface was assessed every 100 cycles. Samples were tested to failure at the completion of 500 cycles. FINDINGS: All sutures held in all specimens during cyclic testing. The gap formation after 500 cycles was greatest with Prolene suture (6.8 mm, SD 1.2) followed by Supramid suture (4.0 mm, SD 1.1) and Ethibond suture (1.7 mm, SD 1.7) (P < 0.05). Repairs with Supramid displayed higher failure load (52.7 N, SD 5.5) as compared to Prolene (37.6N, SD 4.7) (P = 0.001) but not compared to Ethibond (44.9 N, SD 7.1). The failure loads between Prolene and Ethibond did not differ (P = 0.130). INTERPRETATION: Gap formation with Ethibond was significantly lower compared to Supramid and Prolene. The four strand nature of the Supramid repair was superior to Prolene but did not differ compared to Ethibond with respect to failure load. Prolene is the least favourable suture when considering gap formation and failure load, while Ethibond is the most favourable.