Die Möglichkeiten der operativen Rekonstruktion degenerativ veränderter Hüftgelenke sind komplex und vielfältig. Bei den derzeit zur Verfügung stehenden operativen Behandlungsmassnahmen führen die Vor- und Nachteile immer wieder zur Diskussionen und Abwägung der Operationsverfahren. Hierbei stehen sich die rasche postoperative Mobilisierung sowie eine verminderte Rekonvaleszenzzeit mit den diskutierten Nachteilen einer schlechteren Übersichtlichkeit und damit verbundenen Fehlimplantationen gegenüber. Dies und die damit verbundene volkswirtschaftliche Bedeutung sind ein ständiger Ausgangspunkt für das Bemühen den optimalen Zugangsweg zu etablieren. Daher stellte das von Smith-Peterson 1949 publizierte Verfahren einen Meilenstein in der operativen Therapie dar. Hierdurch konnten zum einen die operationstechnischen Vorteile wie auch das volkswirtschaftliche Begehren nach kürzeren postoperativen Verweildauern vereint werden. Die Modifizierung dieses Zugangsweges hat sich bereits in einer großen Anzahl prospektiver Studien als zuverlässiges Rekonstruktionsverfahren etabliert und erfüllt zudem auch die Anforderungen der heutigen Medizin nach ästhetisch schönen Ergebnissen. In der vorliegenden Arbeit wurde eine prospektive Fallstudie des direkten anterioren Zugangs mit einem gesunden Vergleichskollektiv durchgeführt. Mit dem Ziel, die Aktivität ein Jahr postoperativ nach Implantation einer HTEP mit gesunden Probanden zu vergleichen. Von Januar 2009 bis Mai 2011 wurden insgesamt 77 Patienten und 59 Probanden in die Studie aufgenommen. Als Vergleichswerte wurde zum einen die klinische wie auch die radiologische Untersuchung herangezogen. In der klinischen Untersuchung zeigte sich insgesamt ein signifikanter Anstieg der untersuchten Scores im Vergleich mit den präoperativen Ergebnissen bei den Operierten. Im Vergleich zu den Probanden erzielen die Patienten ein Jahr nach HTEP teilweise noch schlechtere Werte in dem Bewegungsumfang und den Aktivitätsniveaus welche mittels der Auswertung des Stepwatches, des TWB und des Arzt-Patienten-Fragebogens erhoben wurden. Die radiologische Bewertung diente zur Feststellung der Positionierung der HTEP. Mit guten Positionierungen durch den direkten anterioren Zugang. Die Bewertung der Funktionalität zwischen den beiden Gruppen erfolgte durch den HHS, XSFMA- D und den Arzt-Patientenfragenbogen. Hierbei konnten ähnliche Ergebnisse, wie bereits oben beschrieben, verzeichnet werden mit guten Werten in der Gruppe der untersuchten Patienten, jedoch einer geringeren Funktionalität im Vergleich zu den Probanden. Die vorliegende Arbeit zeigt, dass der direkte anteriore Zugang die Wiederherstellung eines guten postoperativen Gesundheitszustandes mit erreichen eines hohen postoperativen Aktivitätslevels der Patienten ermöglicht. Ebenso erfüllt dieser Zugangsweg die Anforderungen der heutigen Medizin im Sinne einer schnellen postoperativen Mobilisation. Im Vergleich zu anderen minimal-invasiven Verfahren zeigen sich eine gute Implantierbarkeit, eine gute Positionierung und ein niedriges Komplikationsniveau. Prinzipiell hat der minimal-invasive anteriore Zugang das Potenzial sich als ein Standardverfahren in der operativen Rekonstruktion bei Hüftgelenksersatz zu etablieren, jedoch wäre ein direkter Vergleich mit dem lateralen Zugang erstrebenswert und sollte in weiteren Studien verglichen werden. / Background: The aim of this prospectve study was to evaluate the clinical results one year after total hip arthroplasty performed through a minimally invasive direct anterior approach versus a healthy volunteer group. Methods: 77 patients and 59 probands have been evaltuated applying the Stepwatch activity monitor (SAM), the Harris hip score (HHS), the SF 36, a daliy activity questionnaire (DAQ) and the XSFMA. Results: The average SAM showed significant differences of 5658 steps (patients) compared to 6417 steps (proband) (p=0,011). The same routcome can be seen in the DAQ with 4226 (patients) and 4686 (proband) cycles (p=0,327) respectively. No significant difference occured by using the average HHS reflecting an equal outcome of 90,7 points in the patient group compared to 90.8 points in the proband group (p=0,022). In contrast tot he afore-mentioned HHS, was a significant increase of the XSFMA reported with 10,9 (patients) and 5.0 (proband) (p=0,001). The SF -36 physical component scores were 45.8 (patients) and 50.6 (proband) while the psychometric properties added up to 56.6 (patients) and 55.9 (proband). While the physical component scores (p=0,001) showed a significant difference this couldnt be observed for the psychometric properties (p=0,511). Conclusion: In our study, good results have been obtained after the first year of the total hip arthroplasty, however these are not as beneficial as the outcomes in the healthy volunteer group.

The overall aim of this thesis was to evaluate methods for urinary catheter handling in patients undergoing hip surgery. The intention was to gain knowledge in order to provide optimal and cost- effective care regarding urinary catheterisation in this group of patients. In Study I , 45 of the 86 catheterised patients (52%) contracted nosocomial urinary tract infections (UTIs). Diabetes was a risk factor for developing UTI, and cloxacillin as a perioperative antibiotic prophylaxis seemed to offer a certain protection. Study II was a randomised controlled trial on the effect of clamping (n = 55) or not (n = 58) of the indwelling urinary catheter before removal. No significant differences were found between the groups with respect to time to normal bladder function, need for recatheterisation, or length of hospital stay. Study III was a randomised controlled trial among patients with hip fracture and hip arthroplasty, in which the patients were randomised to intermittent (n = 85) or indwelling (n = 85) urinary catheterisation. No significant differences in nosocomial UTIs (9% vs. 12%) or cost-effectiveness were shown. The patients in the intermittent group regained normal bladder function significantly sooner after surgery. Fourteen percent of the patients in the intermittent group did not need any catheterisation. In Study IV , 30 patients were interviewed about their experiences of bladder emptying and urinary catheterisation. The patients’ views were described through the main category ‘An issue but of varying impact’. Both bladder emptying through micturition and bladder emptying through catheterisation were described as convenient, but also as uncomfortable and an intrusion on dignity. The patients were aware of risks and complications of urinary catheterisation. In conclusion, this thesis indicates that UTI is common in hip surgery patients. Clamping of indwelling catheters seems not necessary. There is no preference for either intermittent or indwelling urinary catheterisation according to the results of this thesis, either for the development of nosocomial UTI or, for cost-effectiveness, or from the patient perspective. Nurses should be aware that catheterisation might make the patients feel exposed, and it is essential that their practice reflect the best available evidence.

This study concerned the development and validation of a hardware and software biomeasurement system, which was designed to be used by physiotherapists, general practitioners and other healthcare professionals. The purpose of the system is to detect and assess gait deviation in the form of reduced post-operative range of movement (ROM) of the replacement hip joint in total hip arthroplasty (THA) patients. In so doing, the following original work is presented: Production of a wearable, microcontroller-equipped system which was able to wirelessly relay accelerometer sensor data of the subject’s key hip-position parameters to a host computer, which logs the data for later analysis. Development of an artificial neural network is also reported, which was produced to process the sensor data and output assessment of the subject’s hip ROM in the flexion/extension and abduction/adduction rotations (forward and backward swing and outward and inward movement of the hip respectively). The review of literature in the area of biomeasurement devices is also presented. A major data collection was carried out using twenty-one THA patients, where the device output was compared to the output of a Vicon motion analysis system which is considered the ‘gold standard’ in clinical gait analysis. The Vicon system was used to show that the device developed did not itself affect the patient’s hip, knee or ankle gait cycle parameters when in use, and produced measurement of hip flexion/extension and abduction/adduction closely approximating those of the Vicon system. In patients who had gait deviations manifesting in reduced ROM of these hip parameters, it was demonstrated that the device was able to detect and assess the severity of these excursions accurately. The results of the study substantiate that the system developed could be used as an aid for healthcare professionals in the following ways: · To objectively assess gait deviation in the form of reduced flexion/extension and abduction/adduction in the human hip, after replacement, · Monitoring of patient hip ROM post-operatively · Assist in the planning of gait rehabilitation strategies related to these hip parameters.

The number of patients electing to undergo total hip arthroplasty (THA) in the United States has been projected to double by the year 2030, with a growing number of these patients below the age of 65 years. This cohort of patients not only desires to return to pain free daily activity, but wishes to participate in recreation and sporting activities. However, many of these patients report pain, impairments, and functional limitations following THA. The number one deficit observed for patients who fail conventional post-operative rehabilitation is persistent weakness of the hip abductor muscles. In order to safely progress these patients back to their desired activity level, appropriate postoperative rehabilitation programs need to be developed. The primary objective of this dissertation was to examine the effectiveness of a hip abductor strengthening program on subjective and objective outcomes following THA. The secondary aims of this study were to document hip muscle activation and lower extremity movement patterns during functional exercises; and to compare shortterm subjective and objective clinical outcomes for subjects following THA compared to controls. Several observations were made from our results. First, the lunge, single leg squat, and step-up and over exercises may be appropriate to include in post-operative rehabilitation programs to transition THA subjects from static strengthening exercises to dynamic activities. Second, subjects at 6- and 12-weeks following THA continue to exhibit strength and functional deficits, which contributes to decreases in activity level. Third, the addition of an exercise program targeting the hip abductor muscles following THA may help to improve subjective and objective outcomes compared to conventional post-operative rehabilitation. Finally, findings from our results are summarized and we propose a model to develop patient-specific rehabilitation programs.

Class of 2017 Abstract / Objectives: The first aim is to assess efficacy of aspirin versus enoxaparin in preventing a venous thromboembolism (VTE) after a total knee arthroplasty (TKA) or total hip arthroplasty (THA) within 30 days after discharge. The second aim is to assess the safety of aspirin versus enoxaparin in preventing major bleeding events after a TKA or THA within 30 days after discharge. Methods: This study was a retrospective cohort study with data obtained from an online Veterans Affairs (VA) hospital database. For analysis, the primary outcome was assessed with a Chi-Square test, and the secondary outcome was reported with descriptive statistics.Results: Results: Demographics for 374 patients (TKA, n = 275; THA, n = 99): 90% male, average age of 65, average body mass index (BMI) of 32, 26% smokers, 72% had a history of hypertension, and 60% had a history of dyslipidemia. VTE events 30 days post-operatively: enoxaparin (n = 2), enoxaparin/aspirin (n = 1), and aspirin (n = 2) (P-value = 0.78). Safety events (major bleeding events): enoxaparin (n = 42), enoxaparin/aspirin (n = 7), and aspirin (n = 4). Conclusions: There was no significant difference between the treatment groups for VTE rate 30 days post- operation. The enoxaparin treatment group had the greatest number of safety events compared to the other groups.

Contexto: O objetivo do estudo foi avaliar a reprodutibilidade intra e interobservador da versão acetabular e femoral da prótese total de quadril. Materiais e métodos: estudo prospectivo incluindo 101 indivíduos submetidos a prótese total de quadril, sendo 114 quadris desde 2008, com imagens de tomografia computadorizada incluindo os componentes acetabular e femoral da prótese e os côndilos femorais. Resultados: Para avaliação intraobservador o coeficiente de correlação interclasse foi para o observador A de 0.99 para versão acetabular e femoral com intervalo de confian- ça (IC) de 0.98-1.00, para o observador B de 0.98 para versão acetabular (IC de 0.97- 0.99) e de 0.88 para versão femoral (IC de 0.83-0.92), para o observador C de 0.98 para versão acetabular (IC de 0.97-0,99) e de 0.83 para versão femoral (IC de 0.76-0.88). Para avaliação interobservador o coeficiente de correlação interclasse foi calculado com as medidas da primeira leitura de cada observador e em seguida da segunda leitura, sendo a primeira leitura da versão acetabular de 0.99 (IC de 0.98-1.00), a segunda leitura da versão acetabular de 0.99 (IC de 0.98-1.00), a primeira leitura da versão femoral de 0.99 (IC de 0.98-1.00), a segunda leitura da versão femoral de 0.96 (IC de 0.94-0.97). Conclusão: Com os resultados obtidos, podemos concluir que as medidas tomográficas de versão acetabular possuem excelente reprodutibilidade tanto inter quanto intraobservador, as medidas de femoral possuem excelente reprodutibilidade interobservador e de boa a excelente reprodutibilidade intraobservador. / Context: The objective of the study was to evaluate the reproducibility intra e interobserver of acetabular and femoral version after total hip arthroplasty. Materials and methods: prospective studying including 101 individuals after total hip arthroplasty, 114 hips since 2008, with computed tomography images including the components of acetabular and femoral prothesis and the femoral condyle. Results: intra-observer coefficient of interclass correlation was 0.99 for observer A for acetabular and femoral version (IC of 0.98-1.00), for B 0.98 for acetabular version (IC of 0.97-0.99) and 0.88 for femoral version (IC of 0.83-0.92), for C 0.98 for acetabular version (IC of 0.97-0.99) and 0.83 for femoral version (IC of 0.76-0.88). For inter-observer evaluation, the interclass correlation coefficient was calculated with the measurements of the first reading of each observer and the second reading, the first reading of the acetabular version was 0.99 (IC of 0.98-1.00), the second reading of the acetabular version was 0.99 (CI 0.98-1.00), the first reading of the femoral version was 0.99 (CI of 0.98-1.00), the second reading of the femoral version was 0.96 (CI of 0.94- 0.97). Conclusion: With the results obtained, we can conclude that the tomographic measurements of acetabular version have excellent inter- and intraobserver reproducibility, femoral measurements have excellent interobserver reproducibility and good to excellent intraobserver reproducibility.

Ph.D.,Dept. of Orthopaedic Surgery, Faculty of Health Sciences, University of the Witwatersrand, 2009. / Total hip replacement (THR) is an effective method of treatment for patients with hip disability. The procedure is capable of providing long-term functional improvement with excellent control of pain and restoration of function. Sir J Charnley developed a concept of low friction arthroplasty, which was based on use of ultra-high molecular weight polyethylene acetabular and stainless steel femoral components. The components were attached to bone with the use of polymethylmethacrylate (PMMA) bone cement. This concept has been very successful, and is considered the gold standard of THR. Aseptic loosening of the prosthetic components remains the single most important reason for failure of THRs. Wear to the ultra high molecular weight polyethylene (UHMWPE) acetabular cup is a well-known cause of osteolysis and aseptic loosening of the components. Thus, substantial improvement to the wear resistance of UHMWPE could extend the clinical life span of total hip replacements. In an attempt to reduce polyethylene wear and subsequent osteolysis, a method was developed in the early seventies in South Africa to improve polyethylene quality by means of gamma ray cross-linking. The acetabular cup was irradiated with 100 Kilogray in an acetylene environment, which was used as a cross-linking gas material, resulting in improvement of UHMWPE wear resistance. Influenced by the world trend and with the advent of a ceramic bearing surface, the Project of cross-linking was, to a certain extent, forgotten. Patients followed up in the late 1990s, showed minimal or total absence of wear after 15 years or longer. 3 Based on my preliminary studies, and anticipating the world trend of acceptance of cross- link UHMWPE, the aim of this research is to consolidate the results from the largest long term group of patients with acetylene cross-link UHMWPE, to study polyethylene gamma irradiated in the presence of a cross-linking acetiylene gas and the effects of it, in vitro, using a hip simulator. I was planning to communicate with as many patients as possible from the group operated on from 1977 until 1983 in whom cross-link UHMWPE was used. This group of over thousand patients represents the largest group of patients with cross-linked UHMWPE acetabular components in the world, with the longest clinical follow up of over 20 years on average. The first part of the research is a retrospective study: The goal was to contact as many patients as possible who were operated on during the period 1977 to 1983 when cross-linked polyethylene was used. To qualified for the study each patient had to have an early postoperative and the latest follow up radiograph. The radiological study consisted of the radiological measurement of wear. For this purpose the Hip Analysis Suite program was used. This is a software program designed by Dr John M. Martell from the University of Chicago, which is widely used and internationally accepted for that purpose. Image analysis offers significant improvements in reproducibility and accuracy when compared to manual analysis. 4 The final results were compared with results of polyethylene wear in patients in whom conventional UHMWPE was used. For this comparison only patients with acetabular components made from the same UHMWPE material and from the same supplier were used. The conventional UHMWPE is a component of the gold standard of hip replacement surgery. World-wide published follow up studies of 15 years and longer using conventional UHMWPE were compared to the cross-link UHMWPE group. If revision surgery was indicated for whatever reason in patients in with cross-linked UHMWPE acetabular components, the retrieved prosthesis was analyzed. The analysis consisted of examination of the articular surface of the cross-linked acetabular component for micro wear phenomena using a Scanning Electron Microscope (SEM). In order to perform an objective analysis of the retrieved components, two independent laboratories were used, namely: Peterson Tribology Laboratory, Loma Linda University, California, and Biomechanical Laboratory, Faculty of Engineering, University of Pretoria. The analyses were possible thanks to collaboration with Dr Ian Clark from Peterson Tribology Laboratory and Dr NDL Burger in charge of the Biomechanical Laboratory at the Department of Engineering, University of Pretoria

Student Number: 9602675T Master of Science in Physiotherapy. Faculty of Health Sciences / The purpose of the study was to compare the outcome in patients following primary total hip arthroplasty, between those receiving a mobility programme alone, as compared to bed exercises and a mobility programme, at discharge from hospital. Thirty-six patients were randomly allocated to either the control or experimental group using a concealed allocation process. The control group received a programme of supervised bed exercises and were mobilised according to the standard postoperative mobility protocol. The experimental group were mobilised according to standard protocol. On the third/fourth and sixth/seventh day postoperatively, patients were assessed by a blinded assessor on functional ability, pain at rest, and active range of hip flexion and abduction. The results indicated no difference in functional ability (p=0.99), pain at rest (p=0.83) and active range of hip flexion (p=0.19) or abduction (p=0.12), on the seventh/eight day postoperatively, between the control and experimental groups. In conclusion bed exercises appear to offer no additional benefit to patients post THA, during the acute hospitalisation phase. However this should not be extrapolated to THA patients who have prolonged bed rest periods postoperatively.

As progressivas inovações tecnológicas, na área de projeto mecânico, contribuem para a adoção de novos procedimentos cirúrgicos relacionados à ortopedia. Este trabalho trata do projeto, desenvolvimento e fabricação de dispositivos de usinagem e instrumentais cirúrgicos para aplicação em cirurgias de recapeamento da cabeça femoral em humanos e animais, buscando aperfeiçoar tal procedimento no que diz respeito a tecnologias voltadas à modelagem óssea e furação centralizada com a cabeça femoral. Nesse contexto, a relação tempo x precisão foi muito bem explorada, de forma a auxiliar com eficiência os cirurgiões e os pacientes que necessitam dessa cirurgia reduzindo a interferência da habilidade do cirurgião no resultado final da cirurgia. A fresa multilaminar sequencial, criada para usinar a cabeça femoral conforme geometria interna da prótese de recapeamento de quadril é uma importante ferramenta para redução do tempo de cirurgia, uma vez que é necessária a troca de ferramentas durante os procedimentos cirúrgicos como mostrado nesta tese. O instrumental cirúrgico, responsável para o funcionamento correto desses dispositivos de usinagem, é um guia de furação personalizado capaz de alinhar a broca e a fresa durante a modelagem da cabeça femoral, de acordo com o ângulo do colo femoral de cada paciente. Assim, este trabalho trata da concepção, desenvolvimento e fabricação de protótipos de um dispositivo de usinagem e instrumentais cirúrgicos que promovam a usinagem centralizada seguindo o ângulo do colo femoral, redução do tempo de cirurgia e da aplicação cirúrgica com prótese de recapeamento artroplastia de recapeamento canina. Os produtos desenvolvidos nesse trabalho serão nomeados como \"fresa multilaminar sequencial\", \"máscara para furação centralizada\" e \"prótese e instrumentais cirúrgicos para cães\", para a artroplastia de recapeamento de quadril. Com os desenvolvimentos, é esperada uma redução no tempo da cirurgia, bem como um aumento na segurança, possibilitando maior sucesso nesses procedimentos em humanos, bem como trás nova tecnologia para a medicina veterinária. / Progressive technological innovations in the area of mechanical design, contribute to the adoption of new surgical procedures related to orthopedics. This work addresses the design development and manufacture of machining devices and surgical instruments to be used in resurfacing surgeries of the femoral head in humans and animals, seeking to improve this procedure in regards to a new technology related to bone structure for machining and drilling aligned with the femoral head. In this context, the relation time c accuracy was very well explored, in order to assist with efficiency surgeons and patients requiring surgery that reduces the interference on the skill of the surgeon on the surgery outcome. The simultaneous development of the multilaminar-mill, designed to machine the femoral head matching the internal geometry of the resurfacing prosthesis is an important tool for reducing the surgery time, as the tool changes during surgery as shown this thesis. The surgical instrument responsible for the proper operation of these machining devices is a customized guide drill mark capable of aligning the drill and the mill during drilling and milling of the femoral head, according to the angle of the femoral neck of each patient. This work deals with the design, development and manufacturing of a machining device prototype and surgical instruments to promote the centralized machining following the angle of the femur neck the reduction of surgery time and the innovate arthroplasty surgery in humans animals. The products developed in this work are named as \"sequential multilaminar mill\", \"drilling centering mask\" and \"prosthesis and instrumental for dogs\", for hip resurfacing arthroplasty. With the developments, it is expected to reduce the surgical time, as well increasing safety, allowing greater success in these procedures.

As progressivas inovações tecnológicas, na área de projeto mecânico, contribuem para a adoção de novos procedimentos cirúrgicos relacionados à ortopedia. Este trabalho trata do projeto, desenvolvimento e fabricação de dispositivos de usinagem e instrumentais cirúrgicos para aplicação em cirurgias de recapeamento da cabeça femoral em humanos e animais, buscando aperfeiçoar tal procedimento no que diz respeito a tecnologias voltadas à modelagem óssea e furação centralizada com a cabeça femoral. Nesse contexto, a relação tempo x precisão foi muito bem explorada, de forma a auxiliar com eficiência os cirurgiões e os pacientes que necessitam dessa cirurgia reduzindo a interferência da habilidade do cirurgião no resultado final da cirurgia. A fresa multilaminar sequencial, criada para usinar a cabeça femoral conforme geometria interna da prótese de recapeamento de quadril é uma importante ferramenta para redução do tempo de cirurgia, uma vez que é necessária a troca de ferramentas durante os procedimentos cirúrgicos como mostrado nesta tese. O instrumental cirúrgico, responsável para o funcionamento correto desses dispositivos de usinagem, é um guia de furação personalizado capaz de alinhar a broca e a fresa durante a modelagem da cabeça femoral, de acordo com o ângulo do colo femoral de cada paciente. Assim, este trabalho trata da concepção, desenvolvimento e fabricação de protótipos de um dispositivo de usinagem e instrumentais cirúrgicos que promovam a usinagem centralizada seguindo o ângulo do colo femoral, redução do tempo de cirurgia e da aplicação cirúrgica com prótese de recapeamento artroplastia de recapeamento canina. Os produtos desenvolvidos nesse trabalho serão nomeados como \"fresa multilaminar sequencial\", \"máscara para furação centralizada\" e \"prótese e instrumentais cirúrgicos para cães\", para a artroplastia de recapeamento de quadril. Com os desenvolvimentos, é esperada uma redução no tempo da cirurgia, bem como um aumento na segurança, possibilitando maior sucesso nesses procedimentos em humanos, bem como trás nova tecnologia para a medicina veterinária. / Progressive technological innovations in the area of mechanical design, contribute to the adoption of new surgical procedures related to orthopedics. This work addresses the design development and manufacture of machining devices and surgical instruments to be used in resurfacing surgeries of the femoral head in humans and animals, seeking to improve this procedure in regards to a new technology related to bone structure for machining and drilling aligned with the femoral head. In this context, the relation time c accuracy was very well explored, in order to assist with efficiency surgeons and patients requiring surgery that reduces the interference on the skill of the surgeon on the surgery outcome. The simultaneous development of the multilaminar-mill, designed to machine the femoral head matching the internal geometry of the resurfacing prosthesis is an important tool for reducing the surgery time, as the tool changes during surgery as shown this thesis. The surgical instrument responsible for the proper operation of these machining devices is a customized guide drill mark capable of aligning the drill and the mill during drilling and milling of the femoral head, according to the angle of the femoral neck of each patient. This work deals with the design, development and manufacturing of a machining device prototype and surgical instruments to promote the centralized machining following the angle of the femur neck the reduction of surgery time and the innovate arthroplasty surgery in humans animals. The products developed in this work are named as \"sequential multilaminar mill\", \"drilling centering mask\" and \"prosthesis and instrumental for dogs\", for hip resurfacing arthroplasty. With the developments, it is expected to reduce the surgical time, as well increasing safety, allowing greater success in these procedures.