Proper component alignment is crucial for a successful total hip arthroplasty (THA). Some studies found safe cup orientations and corresponding stem antetorsions based on a defined desired range of motion (ROM) suitable for activities of daily living. These studies either used complex and time consuming 3D simulations or more simple mathematical formulas which cannot be extended to combined motions. With the method introduced in this work, any arbitrary motion can be applied. The ROM specified as the ROM of the femur relative to the pelvis is transformed into the ROM of the prosthesis neck relative to the cup for each cup orientation. For this transformation, the orientation and design of the stem are considered. The comparison of the neck and cup orientations is done using a 2D mapping of a 3D spherical surface which reduces the complexity of the calculation. We found that the femoral antetorsion as well as the neutral stem flexion and adduction have an influence on the resulting safe zone. The result is not just a combined anteversion but a combined orientation. For validating the plausibility of the algorithm, the resulting safe zones are compared to literature. Same results can be achieved using the same input data. Using this technique, a patient-specific safe zone based on the ROM can be derived and adjusted to the stem orientation.
{"title":"MULTI-DIMENSIONAL RANGE-OF-MOTION-BASED SAFE ZONE FOR PATIENT-SPECIFIC TOTAL HIP ARTHROPLASTY","authors":"Juliana Hsu, M. Fuente, K. Radermacher","doi":"10.29007/VK8V","DOIUrl":"https://doi.org/10.29007/VK8V","url":null,"abstract":"Proper component alignment is crucial for a successful total hip arthroplasty (THA). Some studies found safe cup orientations and corresponding stem antetorsions based on a defined desired range of motion (ROM) suitable for activities of daily living. These studies either used complex and time consuming 3D simulations or more simple mathematical formulas which cannot be extended to combined motions. With the method introduced in this work, any arbitrary motion can be applied. The ROM specified as the ROM of the femur relative to the pelvis is transformed into the ROM of the prosthesis neck relative to the cup for each cup orientation. For this transformation, the orientation and design of the stem are considered. The comparison of the neck and cup orientations is done using a 2D mapping of a 3D spherical surface which reduces the complexity of the calculation. We found that the femoral antetorsion as well as the neutral stem flexion and adduction have an influence on the resulting safe zone. The result is not just a combined anteversion but a combined orientation. For validating the plausibility of the algorithm, the resulting safe zones are compared to literature. Same results can be achieved using the same input data. Using this technique, a patient-specific safe zone based on the ROM can be derived and adjusted to the stem orientation.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"46 1","pages":"54-54"},"PeriodicalIF":0.0,"publicationDate":"2017-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80895611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Olivia Paserin, N. Quader, K. Mulpuri, A. Cooper, E. Schaeffer, A. Hodgson, R. Abugharbieh
Although physical and ultrasound (US)-based screening for congenital deformities of the hip (developmental dysplasia of the hip, or DDH) is routinely performed in most countries, one of the most commonly performed manoeuvres done under ultrasound observation - dynamic assessment - has been shown to be relatively unreliable and is associated with significant misdiagnosis rates, on the order of 29%. Our overall research objective is to develop a quantitative method of assessing hip instability, which we hope will standardise diagnosis across different raters and health-centres, and may perhaps improve reliability of diagnosis. To quantify dynamic assessment, we propose to use the variability in femoral head coverage (FHC) measurements within multiple US scans collected during a dynamic assessment. In every US scan, we use our recently-developed automatic FHC measuring tool which leverages phase symmetry features to approximate vertical cortex of ilium and a random forest classifier to identify approximate location of the femoral head. Having estimated FHC in each scan, we estimate the change in FHC across all the US scans during a dynamic assessment and compare this change with variability of FHC found in previous studies. Our findings - in a dynamic assessment on an infant done by an orthopaedic surgeon, the femoral centre moved by up to 19% of its diameter during distraction, from 55% FHC to 74% FHC. This variability is similar to the variability of FHC in static US scans reported in previous studies, so the variability in FHC readings we found are not indicative of any subluxation or dislocation of the infant9s femoral head. Our clinician9s qualitative assessment concluded the hip to be normal and not indicative of instability. This suggests that our technique likely has sufficient resolution and repeatability to quantify differences in laxity between stable and unstable hips, although this presumption will have to be confirmed in a subsequent study with additional subjects. The long-term significance of this approach to evaluating dynamic assessments may lie in increasing early diagnostic sensitivity in order to prevent dysplasia remaining undetected prior to manifesting itself in early adulthood joint disease.
{"title":"QUANTIFYING DYNAMIC ASSESSMENT OF DEVELOPMENTAL DYSPLASIA OF THE HIP","authors":"Olivia Paserin, N. Quader, K. Mulpuri, A. Cooper, E. Schaeffer, A. Hodgson, R. Abugharbieh","doi":"10.29007/ZH41","DOIUrl":"https://doi.org/10.29007/ZH41","url":null,"abstract":"Although physical and ultrasound (US)-based screening for congenital deformities of the hip (developmental dysplasia of the hip, or DDH) is routinely performed in most countries, one of the most commonly performed manoeuvres done under ultrasound observation - dynamic assessment - has been shown to be relatively unreliable and is associated with significant misdiagnosis rates, on the order of 29%. Our overall research objective is to develop a quantitative method of assessing hip instability, which we hope will standardise diagnosis across different raters and health-centres, and may perhaps improve reliability of diagnosis. To quantify dynamic assessment, we propose to use the variability in femoral head coverage (FHC) measurements within multiple US scans collected during a dynamic assessment. In every US scan, we use our recently-developed automatic FHC measuring tool which leverages phase symmetry features to approximate vertical cortex of ilium and a random forest classifier to identify approximate location of the femoral head. Having estimated FHC in each scan, we estimate the change in FHC across all the US scans during a dynamic assessment and compare this change with variability of FHC found in previous studies. Our findings - in a dynamic assessment on an infant done by an orthopaedic surgeon, the femoral centre moved by up to 19% of its diameter during distraction, from 55% FHC to 74% FHC. This variability is similar to the variability of FHC in static US scans reported in previous studies, so the variability in FHC readings we found are not indicative of any subluxation or dislocation of the infant9s femoral head. Our clinician9s qualitative assessment concluded the hip to be normal and not indicative of instability. This suggests that our technique likely has sufficient resolution and repeatability to quantify differences in laxity between stable and unstable hips, although this presumption will have to be confirmed in a subsequent study with additional subjects. The long-term significance of this approach to evaluating dynamic assessments may lie in increasing early diagnostic sensitivity in order to prevent dysplasia remaining undetected prior to manifesting itself in early adulthood joint disease.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"12 1","pages":"62-62"},"PeriodicalIF":0.0,"publicationDate":"2017-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78813861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kimm, Lucas Jauer, C. Hinke, J. Schleifenbaum, R. Poprawe
Due to tumours or bone fractures caused by high mechanical impact, the affected tissue has to be removed. Preserving the physiological mobility after the treatment could prevent stress shielding or overload of the surrounding muscles and ligaments. In case of a critical vertebral body defect, the body and its attached disks have to be removed. Thereafter the adjacent vertebral bodies are braced together resulting in limited physiological spine movability. A flexible implant adapted to and preserving the patient-specific physiological spine mobility would be a desirable solution. Since Ti6Al4V is a common material for medical implants as well as in AM, it is used in this scientific study. Using design methodology tools, a systematic generation of possible solutions is achieved. Furthermore, already existing solid state hinges made of plastics with AM are taken as archetype and their design is adapted to the metal laser powder bed fusion (L-PBF) process. Therefore, an initial geometry design, based on a solid state hinge demonstrator made by TNO was created with Inventor 2016. By abstracting the vertebrae body segment, two contact surfaces, two joints with rotational degree of freedom (DOF) and axial suspension as well as one solid connection could be identified. As a first implant design, the abstracted joints are replaced by the designed hinges. By the application of simulation software tools the flexion behaviour of the solid state hinge can be analysed. Initial results show that the simulation of the flexion behaviour corresponds with the AM specimen. The applied force necessary for bending the specimen depends on the thickness of the struts.
{"title":"DESIGN OF FLEXIBLE IMPLANTS FOR PRESERVATION OF PHYSIOLOGICAL MOBILITY EXPLOITING ADDITIVE MANUFACTURING","authors":"M. Kimm, Lucas Jauer, C. Hinke, J. Schleifenbaum, R. Poprawe","doi":"10.29007/JLB9","DOIUrl":"https://doi.org/10.29007/JLB9","url":null,"abstract":"Due to tumours or bone fractures caused by high mechanical impact, the affected tissue has to be removed. Preserving the physiological mobility after the treatment could prevent stress shielding or overload of the surrounding muscles and ligaments. In case of a critical vertebral body defect, the body and its attached disks have to be removed. Thereafter the adjacent vertebral bodies are braced together resulting in limited physiological spine movability. A flexible implant adapted to and preserving the patient-specific physiological spine mobility would be a desirable solution. Since Ti6Al4V is a common material for medical implants as well as in AM, it is used in this scientific study. Using design methodology tools, a systematic generation of possible solutions is achieved. Furthermore, already existing solid state hinges made of plastics with AM are taken as archetype and their design is adapted to the metal laser powder bed fusion (L-PBF) process. Therefore, an initial geometry design, based on a solid state hinge demonstrator made by TNO was created with Inventor 2016. By abstracting the vertebrae body segment, two contact surfaces, two joints with rotational degree of freedom (DOF) and axial suspension as well as one solid connection could be identified. As a first implant design, the abstracted joints are replaced by the designed hinges. By the application of simulation software tools the flexion behaviour of the solid state hinge can be analysed. Initial results show that the simulation of the flexion behaviour corresponds with the AM specimen. The applied force necessary for bending the specimen depends on the thickness of the struts.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"6 1","pages":"21-21"},"PeriodicalIF":0.0,"publicationDate":"2017-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80221221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Computer-assisted orthopaedic surgery (CAOS) has been demonstrated to increase accuracy to component alignment of total knee arthroplasty compared to conventional techniques. The purpose of this study was to assess if learning affects resection alignment using a specific CAOS system. Nine surgeons, each with >80 TKA experience using a contemporary CAOS system were selected. Prior to the study, six surgeons had already experienced with CAOS TKA (experienced), while the rest three were new to the technology (novice). The following surgical parameters were investigated: 1) planned resection, resection parameters defined by the surgeon prior to the bone cuts; 2) checked resection, digitalisation of the realised resection surfaces. Deviations in the alignment between planned and checked resections were compared between the first 20 cases (in learning curve) and the last 20 cases (well past learning curve) within each surgeon. Any significance detected (p 1° difference in means indicated clinically meaningful impact on alignment by the learning phase. Both pooled and surgeon-specific analysis exhibited no clinically meaningful significant difference between the first 20 and the last 20 cases from both experienced and novice surgeon groups. The resections in both the first 20 and the last 20 cases demonstrated acceptable rates of over 95% in alignment ( This study demonstrated that independent of the surgeon9s prior CAOS experiences, the CAOS system investigated can provide an accurate and precise solution to assist in achieving surgical resection goals with no clinically meaningful compromise in alignment accuracy and outliers during the learning phase.
{"title":"DOES LEARNING CURVE AFFECT THE ACCURACY IN RESECTION ALIGNMENT DURING NAVIGATED TOTAL KNEE ARTHROPLASTY","authors":"Y. Dai, C. Hamad, A. Jung, L. Angibaud","doi":"10.29007/rxll","DOIUrl":"https://doi.org/10.29007/rxll","url":null,"abstract":"Computer-assisted orthopaedic surgery (CAOS) has been demonstrated to increase accuracy to component alignment of total knee arthroplasty compared to conventional techniques. The purpose of this study was to assess if learning affects resection alignment using a specific CAOS system. Nine surgeons, each with >80 TKA experience using a contemporary CAOS system were selected. Prior to the study, six surgeons had already experienced with CAOS TKA (experienced), while the rest three were new to the technology (novice). The following surgical parameters were investigated: 1) planned resection, resection parameters defined by the surgeon prior to the bone cuts; 2) checked resection, digitalisation of the realised resection surfaces. Deviations in the alignment between planned and checked resections were compared between the first 20 cases (in learning curve) and the last 20 cases (well past learning curve) within each surgeon. Any significance detected (p 1° difference in means indicated clinically meaningful impact on alignment by the learning phase. Both pooled and surgeon-specific analysis exhibited no clinically meaningful significant difference between the first 20 and the last 20 cases from both experienced and novice surgeon groups. The resections in both the first 20 and the last 20 cases demonstrated acceptable rates of over 95% in alignment ( This study demonstrated that independent of the surgeon9s prior CAOS experiences, the CAOS system investigated can provide an accurate and precise solution to assist in achieving surgical resection goals with no clinically meaningful compromise in alignment accuracy and outliers during the learning phase.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"37 1","pages":"10-10"},"PeriodicalIF":0.0,"publicationDate":"2017-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83731763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-04-01DOI: 10.3389/conf.FBIOE.2016.01.01485
T. Thangarajah, C. Pendegrass, S. Shahbazi, S. Lambert, S. Alexander, G. Blunn
Background Re-attachment of tendon to bone is challenging with surgical repair failing in up to 90% of cases. Poor biological healing is common and characterised by the formation of weak scar tissue. Previous work has demonstrated that decellularised allogenic demineralised bone matrix (DBM) regenerates a physiologic enthesis. Xenografts offer a more cost-effective option but concerns over their immunogenicity have been raised. We hypothesised that augmentation of a healing tendon-bone interface with DBM incorporated with autologous mesenchymal stem cells (MSCs) would result in improved function, and restoration of the native enthesis, with no difference between xenogenic and allogenic scaffolds. Methods Using an ovine model of tendon-bone retraction the patellar tendon was detached and a complete distal tendon defect measuring 1 cm was created. Suture anchors were used to reattach the shortened tendon and xenogenic DBM + MSCs (n=5) and allogenic DBM + MSCs (n=5) were used to bridge the defect. Functional recovery was assessed every 3 weeks and DBM incorporation into the tendon and its effect on enthesis regeneration was measured using histomorphometry. Results By 12 weeks, DBM augmentation resulted in significantly improved functional weight bearing with no failures in either group. Compared to xenogenic DBM, allogenic DBM was associated with significantly higher functional weight bearing at 6 (P=0.047), 9 (P=0.028) and 12 weeks (P=0.009). This was accompanied by a more direct type of enthesis characterised by significantly more fibrocartilage and mineralised fibrocartilage. Xenograft was also associated with an immunogenic reaction despite preoperative decellularisation. Conclusion This study shows that DBM enhances tendon-bone healing and may reduce the high failure rates associated with surgery. An immunogenic reaction, and inferior biomechanical and histological results were also associated with the use of xenograft. Allogenic DBM with autologous MSCs may be a suitable scaffold for the enhancement of tendon-bone healing in the clinical setting. Disclosures Funded by IKC PoC grant awarded by the University of Leeds Ethical approval Granted by the study institution (University College London)
{"title":"TENDON REATTACHMENT USING DEMINERALISED BONE MATRIX AND MESENCHYMAL STEM CELLS","authors":"T. Thangarajah, C. Pendegrass, S. Shahbazi, S. Lambert, S. Alexander, G. Blunn","doi":"10.3389/conf.FBIOE.2016.01.01485","DOIUrl":"https://doi.org/10.3389/conf.FBIOE.2016.01.01485","url":null,"abstract":"Background Re-attachment of tendon to bone is challenging with surgical repair failing in up to 90% of cases. Poor biological healing is common and characterised by the formation of weak scar tissue. Previous work has demonstrated that decellularised allogenic demineralised bone matrix (DBM) regenerates a physiologic enthesis. Xenografts offer a more cost-effective option but concerns over their immunogenicity have been raised. We hypothesised that augmentation of a healing tendon-bone interface with DBM incorporated with autologous mesenchymal stem cells (MSCs) would result in improved function, and restoration of the native enthesis, with no difference between xenogenic and allogenic scaffolds. Methods Using an ovine model of tendon-bone retraction the patellar tendon was detached and a complete distal tendon defect measuring 1 cm was created. Suture anchors were used to reattach the shortened tendon and xenogenic DBM + MSCs (n=5) and allogenic DBM + MSCs (n=5) were used to bridge the defect. Functional recovery was assessed every 3 weeks and DBM incorporation into the tendon and its effect on enthesis regeneration was measured using histomorphometry. Results By 12 weeks, DBM augmentation resulted in significantly improved functional weight bearing with no failures in either group. Compared to xenogenic DBM, allogenic DBM was associated with significantly higher functional weight bearing at 6 (P=0.047), 9 (P=0.028) and 12 weeks (P=0.009). This was accompanied by a more direct type of enthesis characterised by significantly more fibrocartilage and mineralised fibrocartilage. Xenograft was also associated with an immunogenic reaction despite preoperative decellularisation. Conclusion This study shows that DBM enhances tendon-bone healing and may reduce the high failure rates associated with surgery. An immunogenic reaction, and inferior biomechanical and histological results were also associated with the use of xenograft. Allogenic DBM with autologous MSCs may be a suitable scaffold for the enhancement of tendon-bone healing in the clinical setting. Disclosures Funded by IKC PoC grant awarded by the University of Leeds Ethical approval Granted by the study institution (University College London)","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"58 1","pages":"42-42"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86528496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-01DOI: 10.3389/CONF.FBIOE.2016.01.00836
O. Muratoglu, V. Suhardi, D. Bichara, Sheldon J. J. Kwok, A. Freiberg, H. Rubash, S. Yun, E. Oral
Introduction About 2% of primary total joint replacement arthroplasty (TJA) procedures become infected. Periprosthetic joint infection (PJI) is currently one of the main reasons requiring costly TJA revisions, posing a burden on patients, physicians and insurance companies. 1 Currently used drug-eluting polymers such as bone cements offer limited drug release profiles, sometimes unable to completely clear out bacterial microorganisms within the joint space. For this study we determined the safety and efficacy of an antibiotic-eluting UHMWPE articular surface that delivered local antibiotics at optimal concentrations to treat PJI in a rabbit model. Materials and Methods Skeletally mature adult male New Zealand White rabbits received either two non-antibiotic eluting UHMWPE (CONTROL, n=5) or vancomycin-eluting UHMWPE (TEST, n=5) (3 mm in diameter and 6 mm length) in the patellofemoral groove ( Fig. 1 ). All rabbits received a beaded titanium rod in the tibial canal (4 mm diameter and 12 mm length). Both groups received two doses of 5 × 10 7 cfu of bioluminescent S. aureus (Xen 29, PerkinElmer 119240) in 50 µL 0.9 % saline in the following sites: (1) distal tibial canal prior to insertion of the rod; (2) articular space after closure of the joint capsule ( Fig. 1 ). None of the animals received any intravenous antibiotics for this study. Bioluminescence signal (photons/second) was measured when the rabbits expired, or at the study endpoint (day 21). The metal rods were stained with BacLight ® Bacterial Live-Dead Stain and imaged using two-photon microscopy to detect live bacteria. Hardware, polyethylene implants and joint tissues were sonicated to further quantify live bacteria via plate seeding. Results All control rabbits expired within 7 days ( Fig. 2a). One rabbit in the test group expired at day 7 and another at day 15. All control rabbits had positive bioluminescence (live bacteria), while none of the test rabbits did (Fig 2b). Kidney (creatinine and BUN) and liver functions (ALT and ALP) remained normal for all rabbits. All control rabbits showed positive bacterial culture after sonication, while all test rabbits were negative. Two-photon imaging showed 75±10 % viability for bacteria adhered to the metal rods in the control and no viability in the test group. Discussion This rabbit model showed that vancomycin eluted from UHMWPE is sufficient to eradicate S. aureus in joint space and in between the bone-implant interface of tibial canal. One limitation of this study is the lack of intravenous antibiotic treatment, which is standard clinical practice. In addition, joint infections are often associated with already formed biofilms, which were not tested in this study. However, safety data (normal kidney and liver functions) and complete eradication of S. aureus is an encouraging finding. Conclusion Vancomycin-eluting UHMWPE effectively eliminated bacteria in a rabbit model of acute peri-prosthetic joint infection. This material is promising as
{"title":"VANCOMYCIN-ELUTING ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE TO TREAT PERIPROSTHETIC JOINT INFECTIONS","authors":"O. Muratoglu, V. Suhardi, D. Bichara, Sheldon J. J. Kwok, A. Freiberg, H. Rubash, S. Yun, E. Oral","doi":"10.3389/CONF.FBIOE.2016.01.00836","DOIUrl":"https://doi.org/10.3389/CONF.FBIOE.2016.01.00836","url":null,"abstract":"Introduction About 2% of primary total joint replacement arthroplasty (TJA) procedures become infected. Periprosthetic joint infection (PJI) is currently one of the main reasons requiring costly TJA revisions, posing a burden on patients, physicians and insurance companies. 1 Currently used drug-eluting polymers such as bone cements offer limited drug release profiles, sometimes unable to completely clear out bacterial microorganisms within the joint space. For this study we determined the safety and efficacy of an antibiotic-eluting UHMWPE articular surface that delivered local antibiotics at optimal concentrations to treat PJI in a rabbit model. Materials and Methods Skeletally mature adult male New Zealand White rabbits received either two non-antibiotic eluting UHMWPE (CONTROL, n=5) or vancomycin-eluting UHMWPE (TEST, n=5) (3 mm in diameter and 6 mm length) in the patellofemoral groove ( Fig. 1 ). All rabbits received a beaded titanium rod in the tibial canal (4 mm diameter and 12 mm length). Both groups received two doses of 5 × 10 7 cfu of bioluminescent S. aureus (Xen 29, PerkinElmer 119240) in 50 µL 0.9 % saline in the following sites: (1) distal tibial canal prior to insertion of the rod; (2) articular space after closure of the joint capsule ( Fig. 1 ). None of the animals received any intravenous antibiotics for this study. Bioluminescence signal (photons/second) was measured when the rabbits expired, or at the study endpoint (day 21). The metal rods were stained with BacLight ® Bacterial Live-Dead Stain and imaged using two-photon microscopy to detect live bacteria. Hardware, polyethylene implants and joint tissues were sonicated to further quantify live bacteria via plate seeding. Results All control rabbits expired within 7 days ( Fig. 2a). One rabbit in the test group expired at day 7 and another at day 15. All control rabbits had positive bioluminescence (live bacteria), while none of the test rabbits did (Fig 2b). Kidney (creatinine and BUN) and liver functions (ALT and ALP) remained normal for all rabbits. All control rabbits showed positive bacterial culture after sonication, while all test rabbits were negative. Two-photon imaging showed 75±10 % viability for bacteria adhered to the metal rods in the control and no viability in the test group. Discussion This rabbit model showed that vancomycin eluted from UHMWPE is sufficient to eradicate S. aureus in joint space and in between the bone-implant interface of tibial canal. One limitation of this study is the lack of intravenous antibiotic treatment, which is standard clinical practice. In addition, joint infections are often associated with already formed biofilms, which were not tested in this study. However, safety data (normal kidney and liver functions) and complete eradication of S. aureus is an encouraging finding. Conclusion Vancomycin-eluting UHMWPE effectively eliminated bacteria in a rabbit model of acute peri-prosthetic joint infection. This material is promising as ","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"53 1","pages":"26-26"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90828709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-02-01DOI: 10.26226/morressier.57bda142d462b80290b4cb92
D. Campbell, K. Sharpe, R. Cohen
Introduction Cementless tapered wedge stems have shown excellent results over the last decade. Distal potting with inadequate proximal fit, as well as failure to achieve biologic fixation has led to thigh pain, loosening and implant failure. To support a variety of patient morphologies a novel tapered wedge stem was designed with reduced distal morphology, maximizing the proximal contact of the grit blasted surface. The objective of the study was to analyze the clinical outcomes of this stem design. Methods Three hundred and nineteen patients enrolled into prospective, post-market multicenter studies received a novel tapered wedge stem. Clinical and patient-reported outcomes including the Harris Hip Score (HHS), Lower Extremity Activity Scale (LEAS), Short Form 12 (SF12), and Euroqol 5D Score (EQ-5D) were evaluated preoperative through two years postoperative. Results Demographics of the study population include 53.3% male patients with a mean age of 62.4 ± 9.3 years and BMI of 29.8 ± 4.5. To date, there has been one incidence of thigh pain (0.3%) and a 0.63% aseptic revision rate. Kaplan-Meier survivorship analysis for the population at two years postoperative estimated 97.87% with 95% CI (93.98% – 99.25%) survivorship to all cause revision ( Figure 1 ). Statistically significant improvements in pain, function, and quality of life were seen initially at six weeks postoperative and continued through one year in all of the clinical and patient reported outcome measures ( Figure 2 ). Conclusion A novel tapered wedge stem was designed to maximize proximal fit medially and laterally across a variety of patient morphologies. Radiographic studies have shown the stem design has significantly better canal fit compared to older tapered wedge designs. The current study exhibits low incidence of thigh pain and revisions, with improvements in function, pain and quality of life after hip arthroplasty with this tapered wedge stem.
在过去的十年中，无水泥锥形楔形阀杆取得了很好的效果。远端植入与近端配合不足，以及未能实现生物固定导致大腿疼痛、松动和植入物失败。为了支持各种患者的形态，设计了一种新型锥形楔形茎，其远端形态减少，最大限度地增加了磨砂表面的近端接触。本研究的目的是分析该系统设计的临床结果。方法纳入前瞻性、上市后多中心研究的319例患者接受了新型锥形楔形茎。临床和患者报告的结果包括Harris髋关节评分(HHS)、下肢活动量表(LEAS)、Short Form 12 (SF12)和Euroqol 5D评分(EQ-5D)在术前至术后两年进行评估。结果研究人群中男性占53.3%，平均年龄62.4±9.3岁，BMI 29.8±4.5。迄今为止，有一例大腿疼痛发生率(0.3%)和0.63%的无菌修复率。术后两年人群Kaplan-Meier生存分析估计为97.87%，95% CI(93.98% - 99.25%)的全因修正生存率(图1)。从统计上看，术后6周疼痛、功能和生活质量得到显著改善，所有临床和患者报告的结果测量持续了一年(图2)。结论设计了一种新型锥形楔形柄，可以最大限度地近端配合各种患者的内侧和外侧形态。放射学研究表明，与较老的锥形楔形设计相比，根管设计具有更好的根管配合度。目前的研究显示，采用锥形楔柄髋关节置换术后，大腿疼痛和修复的发生率较低，功能、疼痛和生活质量均有改善。
{"title":"A NOVEL TAPERED WEDGE STEM: MULTICENTRE CLINICAL OUTCOMES STUDY","authors":"D. Campbell, K. Sharpe, R. Cohen","doi":"10.26226/morressier.57bda142d462b80290b4cb92","DOIUrl":"https://doi.org/10.26226/morressier.57bda142d462b80290b4cb92","url":null,"abstract":"Introduction Cementless tapered wedge stems have shown excellent results over the last decade. Distal potting with inadequate proximal fit, as well as failure to achieve biologic fixation has led to thigh pain, loosening and implant failure. To support a variety of patient morphologies a novel tapered wedge stem was designed with reduced distal morphology, maximizing the proximal contact of the grit blasted surface. The objective of the study was to analyze the clinical outcomes of this stem design. Methods Three hundred and nineteen patients enrolled into prospective, post-market multicenter studies received a novel tapered wedge stem. Clinical and patient-reported outcomes including the Harris Hip Score (HHS), Lower Extremity Activity Scale (LEAS), Short Form 12 (SF12), and Euroqol 5D Score (EQ-5D) were evaluated preoperative through two years postoperative. Results Demographics of the study population include 53.3% male patients with a mean age of 62.4 ± 9.3 years and BMI of 29.8 ± 4.5. To date, there has been one incidence of thigh pain (0.3%) and a 0.63% aseptic revision rate. Kaplan-Meier survivorship analysis for the population at two years postoperative estimated 97.87% with 95% CI (93.98% – 99.25%) survivorship to all cause revision ( Figure 1 ). Statistically significant improvements in pain, function, and quality of life were seen initially at six weeks postoperative and continued through one year in all of the clinical and patient reported outcome measures ( Figure 2 ). Conclusion A novel tapered wedge stem was designed to maximize proximal fit medially and laterally across a variety of patient morphologies. Radiographic studies have shown the stem design has significantly better canal fit compared to older tapered wedge designs. The current study exhibits low incidence of thigh pain and revisions, with improvements in function, pain and quality of life after hip arthroplasty with this tapered wedge stem.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"22 1","pages":"59-59"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89023349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-01DOI: 10.1016/j.arthro.2017.08.161
A. Younger, J. Ngai, M. Penner, A. Veljkovic, K. Wing, H. Wong
{"title":"RESOURCE UTILISATION AFTER SURGERY FOR END-STAGE ANKLE ARTHRITIS: COMPARISON BETWEEN ANKLE REPLACEMENT, OPEN AND ARTHROSCOPIC ANKLE FUSION","authors":"A. Younger, J. Ngai, M. Penner, A. Veljkovic, K. Wing, H. Wong","doi":"10.1016/j.arthro.2017.08.161","DOIUrl":"https://doi.org/10.1016/j.arthro.2017.08.161","url":null,"abstract":"","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"47 1","pages":"27-27"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80078941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-10-01DOI: 10.1302/1358-992X.98BSUPP_16.BORS2016-038
R. MacLeod, M. Whitehouse, H. Gill, E. Pegg
Femoral head collapse due to avascular necrosis (AVN) is a relatively rare occurrence following intertrochanteric fractures; however, with over thirty-thousand intertrochanteric fractures per year in England and Wales alone, and an incidence of up to 1.16%, it is still significant. Often patients are treated with a hip fixation device, such as a sliding hip screw or X-Bolt. This study aimed to investigate the influence of three factors on the likelihood of head collapse: (1) implant type; (2) the size of the femoral head; and (3) the size of the AVN lesion. Finite element (FE) models of an intact femur, and femurs implanted with two common hip fixation designs, the Compression Hip Screw (Smith & Nephew) and the X-Bolt (X-Bolt Orthopaedics), were developed. Experimental validation of the FE models on 4 th generation Sawbones composite femurs (n=5) found the peak failure loads predicted by the implanted model was accurate to within 14%. Following validation on Sawbones, the material modulus (E) was updated to represent cancellous (E=500MPa) and cortical (E=1GPa) bone, and the influence of implant design, head size, and AVN was examined. Four head sizes were compared: mean male (48.4 mm) and female (42.2 mm) head sizes ± two standard deviations. A conical representation of an AVN lesion with a lower modulus (1MPa) was created, and four different radii were studied. The risk of head collapse was assessed from (1) the critical buckling pressure and (2) the peak failure stress. The likelihood of head collapse was reduced by implantation of either fixation device. Smaller head sizes and greater AVN lesion size increased the risk of femoral head collapse. These results indicate the treatment of intertrochanteric fractures with a hip fixation device does not increase the risk of head collapse; however, patient factors such as small head size and AVN severity significantly increase the risk.
{"title":"HOW DO IMPLANT TYPE, HEAD SIZE AND AVN LESION SIZE AFFECT THE LIKELIHOOD OF FEMORAL HEAD COLLAPSE FOLLOWING HIP FIXATION?","authors":"R. MacLeod, M. Whitehouse, H. Gill, E. Pegg","doi":"10.1302/1358-992X.98BSUPP_16.BORS2016-038","DOIUrl":"https://doi.org/10.1302/1358-992X.98BSUPP_16.BORS2016-038","url":null,"abstract":"Femoral head collapse due to avascular necrosis (AVN) is a relatively rare occurrence following intertrochanteric fractures; however, with over thirty-thousand intertrochanteric fractures per year in England and Wales alone, and an incidence of up to 1.16%, it is still significant. Often patients are treated with a hip fixation device, such as a sliding hip screw or X-Bolt. This study aimed to investigate the influence of three factors on the likelihood of head collapse: (1) implant type; (2) the size of the femoral head; and (3) the size of the AVN lesion. Finite element (FE) models of an intact femur, and femurs implanted with two common hip fixation designs, the Compression Hip Screw (Smith & Nephew) and the X-Bolt (X-Bolt Orthopaedics), were developed. Experimental validation of the FE models on 4 th generation Sawbones composite femurs (n=5) found the peak failure loads predicted by the implanted model was accurate to within 14%. Following validation on Sawbones, the material modulus (E) was updated to represent cancellous (E=500MPa) and cortical (E=1GPa) bone, and the influence of implant design, head size, and AVN was examined. Four head sizes were compared: mean male (48.4 mm) and female (42.2 mm) head sizes ± two standard deviations. A conical representation of an AVN lesion with a lower modulus (1MPa) was created, and four different radii were studied. The risk of head collapse was assessed from (1) the critical buckling pressure and (2) the peak failure stress. The likelihood of head collapse was reduced by implantation of either fixation device. Smaller head sizes and greater AVN lesion size increased the risk of femoral head collapse. These results indicate the treatment of intertrochanteric fractures with a hip fixation device does not increase the risk of head collapse; however, patient factors such as small head size and AVN severity significantly increase the risk.","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"14 1","pages":"38-38"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84083902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-07-01DOI: 10.6092/UNIBO/AMSDOTTORATO/7704
M. Cavallo, M. Maglio, A. Parrilli, L. Martini, E. Guerra, S. Pagani, M. Fini, R. Rotini
Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting is currently the procedure of choice because of high osteogenic potential and resistance against reabsorption. Disadvantages of this procedure include limited availability of donor sites, clinical difficulty in handling, and a failure rate exceeding 10%. Allografts are often used for massive bone loss, but since only the marginal portion is newly vascularized after the implantation non healing fractures are often reported, along with a graft reabsorption. To overcome these problems, some studies in literature tried to conjugate bone graft and vascular supply, with encouraging results. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization. In fact, bone marrow contains not only hematopoietic stem cells (HSCs) and MSCs as a source for regenerating tissues but also accessory cells that support angiogenesis and vasculogenesis by producing several growth factors. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold. Twenty-four New Zealand male white rabbits (2500–3000 g) were divided into 2 groups, each consisting of 12 animals. Surgeries were performed as follow: −Group 1 (#12): allogenic bone graft (left radius) / allogenic bone graft + vascular pedicle + autologous bone marrow concentrate (right radius) −Group 2 (#12): sham operated (left radius)/ allogenic bone graft + vascular pedicle (right radius) For each group, 3 experimental time: 8, 4 and 2 weeks (4 animals for each time). The bone used as graft was previously collected from an uncorrelated study. An in vitro evaluation of bone marrow concentrate was performed in all cases, and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed in all cases. The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications such as infection or intolerance to the procedure were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement, with a good and healthy residual bone. immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice tim
{"title":"VASCULARISED HOMOLOGOUS BONE GRAFT AND BONE MARROW NUCLEATED CELLS TRANSPLANTATION TO ENHANCE ANGIOGENESIS IN THE REPAIR OF CRITICAL SIZE BONE DEFECT: AN ANIMAL STUDY","authors":"M. Cavallo, M. Maglio, A. Parrilli, L. Martini, E. Guerra, S. Pagani, M. Fini, R. Rotini","doi":"10.6092/UNIBO/AMSDOTTORATO/7704","DOIUrl":"https://doi.org/10.6092/UNIBO/AMSDOTTORATO/7704","url":null,"abstract":"Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting is currently the procedure of choice because of high osteogenic potential and resistance against reabsorption. Disadvantages of this procedure include limited availability of donor sites, clinical difficulty in handling, and a failure rate exceeding 10%. Allografts are often used for massive bone loss, but since only the marginal portion is newly vascularized after the implantation non healing fractures are often reported, along with a graft reabsorption. To overcome these problems, some studies in literature tried to conjugate bone graft and vascular supply, with encouraging results. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization. In fact, bone marrow contains not only hematopoietic stem cells (HSCs) and MSCs as a source for regenerating tissues but also accessory cells that support angiogenesis and vasculogenesis by producing several growth factors. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold. Twenty-four New Zealand male white rabbits (2500–3000 g) were divided into 2 groups, each consisting of 12 animals. Surgeries were performed as follow: −Group 1 (#12): allogenic bone graft (left radius) / allogenic bone graft + vascular pedicle + autologous bone marrow concentrate (right radius) −Group 2 (#12): sham operated (left radius)/ allogenic bone graft + vascular pedicle (right radius) For each group, 3 experimental time: 8, 4 and 2 weeks (4 animals for each time). The bone used as graft was previously collected from an uncorrelated study. An in vitro evaluation of bone marrow concentrate was performed in all cases, and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed in all cases. The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications such as infection or intolerance to the procedure were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement, with a good and healthy residual bone. immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice tim","PeriodicalId":15048,"journal":{"name":"Journal of Bone and Joint Surgery-british Volume","volume":"37 1","pages":"80-80"},"PeriodicalIF":0.0,"publicationDate":"2016-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80920997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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