Greater trochanteric pain (GTP) is a regional pain syndrome characterized by lateral hip pain and tenderness. Its incidence after total hip arthroplasty (THA) is variable. Bursal inflammation, degenerative changes of the attachment of the gluteal muscles, direct operative trauma and biomechanical disturbance of the operated hip have been discussed as being related to GTP. The diagnosis is purely clinical because radiological and laboratory investigations show no definite pathology. Although most treatment modalities are conservative, some patients may develop refractory complaints leading to surgical intervention. In study I we studied the incidence of GTP in 172 consecutive patients who underwent THA during 2002 at Sundsvall Hospital. Patients with GTP (n=21, incidence 12%) were matched with controls from the same cohort. The THA outcome was assessed using the Western Ontario and McMaster Universities Arthrosis (WOMAC) Index. Trochanteric tenderness was studied using an electronic pressure algometer. We found an association between the occurrence of GTP and postoperative uncorrected lengthening of the operated limb of ≥ one centimetre. The WOMAC index revealed a reduction of the clinical outcome in the GTP group. In Study II we tested the value of using an algometer in the diagnosis of GTP after THA. We measured the pressure-pain threshold (PPT) over the greater trochanter and ilio-tibial band in 18 patients and 18 matched controls. Both groups were evaluated using the visual analogue scale (VAS). We found the algometer to have a good predictive validity and reproducibility. However, there was large inter-individual variability across subjects. The PPT ratio of 0.8 (affected vs. unaffected side) can be used as a cutoff ratio to establish GTP. There was no correlation between PPT measurements and VAS. Because of a low positive predictive value and large inter-individual variability, the pressure algometer has a limited value as a screening tool. In study III we proposed a new surgical treatment for refractory GTP after THA consisting of distal lengthening of the ilio-tibial band (ITB) by Z-plasty under local anaesthesia. This method was used in 12 women between March 2004 and June 2006. The patients were followed up by phone interview 3-4 months postoperatively and by an EQ-5D questionnaire and clinical examination including evaluation with the algometer at 1-3 years postoperatively. We found that the patients‘ quality of life was markedly improved following the operation (EQ-5D = 0.26 preoperatively vs. 0.67 postoperatively; p <0.005). There were no postoperative complications. In study IV we evaluated the accuracy of a commonly used clinical method of LLD measurement (anterior superior iliac spine-medial malleolus) by comparing it to a reliable radiological method (tear drop-lesser trochanter) in 139 patients before and after THA. We found the correlation between the clinical and radiological methods to be weak preoperatively (r=0.21, ICC= 0.33) while the correlation was moderate postoperatively (r= 0.45, ICC=0.62). It is therefore recommended that the radiological method be used to measure leg length discrepancy in patients who undergo THA.

Vid operation av primär total höftplastik finns det olika metoder för postoperativ smärtlindring. En tidigare genomförd studie på ett mellansvenskt sjukhus (nedan kallad ”höftprojektet”) visade att ”Local infiltration analgesia” (LIA) initialt minskade postoperativ smärta, underlättade mobilisering samt förkortade vårdtiden, jämfört med spinalt morfin. I denna studie genomfördes en långtidsuppföljning av höftprojektet med mätningar efter 6 respektive 12 veckor. Studiegruppen hade fått LIA vid operationsslutet och kontrollgruppen spinalt morfin. Båda grupperna hade en spinal bedövning under operationen. Denna långtidsuppföljning genomfördes med hjälp av journalgranskning och hade en deskriptiv och jämförande design med en kvantitativ ansats. Studiegruppen bestod av 40 patienter och kontrollgruppen 11 patienter. Studerade variabler var smärta mätt genom Visuell Analog Skala (VAS), behov av analgetika och mobilisering. Resultatet visade att det inte fanns någon signifikant skillnad mellan de båda grupperna när det gäller mobilisering under ett längre perspektiv. Det fanns dock en signifikant skillnad när det gäller smärta efter 3 månader, då studiegruppen uppgav en lägre grad av smärta än kontrollgruppen. / There are several methods for postoperative pain treatment after primary total hip replacement. It was shown in a earlier study at a Swedish hospital (below named as "the hip project") that "Local infiltration analgesia" (LIA) decreased pain, facilitated early postoperative mobility and earlier discharge from the hospital, compared with spinally administered morphine. Present study is a long term follow up of the hip project with two measures at 6 and 12 weeks. The study group was given LIA towards the end of the operation while the control group were given spinal morphine at the induction. Both groups had spinal analgesia during the surgery. The long term follow up was conducted by a comparative design and the data was collected from the patient’s charts and files. The variables were pain measured by Visual Analogous Scale (VAS), need of pain relieves and general mobility. The study group contained of 40 patients and the control group of 11. The result relived no significant differences between the two groups regarding long term mobility. There was, however, a significant difference in pain after 12 weeks; the study group had less pain that the control group.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Όταν οι κλινικοεργαστηριακές πληροφορίες είναι ανεπαρκείς για τη διά- γνωση σηπτικής φλεγμονής επί αρθροπλαστικής ισχίου, η Πυρηνική Ιατρική μπορεί να προσφέρει σημαντικά στη διαφοροδιάγνωση. Σκοπός της παρούσας προοπτικής μελέτης είναι ο έλεγχος της καταλληλότητας του σπινθηρογραφήματος με σημασμένα με 99mΤc μονοκλωνικά Fab-τμήματα αντισωμάτων ποντικού (IMMU-MN3, Leuko- Scan®) ως προς την ακριβή τοπογραφική εντόπιση και διάγνωση περιπροθετικών σηπτικών φλεγμονών επί αρθροπλαστικής ισχίου. Στο διάστημα 1/2001-2/2004 διερευνήθηκαν 21 ασθενείς με 21 αρθροπλαστικές ισχίου (12 ολικές αρθροπλαστικές χωρίς και 3 με τσιμέντο, 2 υβριδιακές αρθροπλαστικές, 3 αρθροπλαστικές διπλής κίνησης και 1 ημιολική) ως προς την πιθανότητα περιπροθετικής λοίμωξης και σηπτικής χαλάρωσης της αρθροπλαστικής. Ο χρόνος παρακολούθησης (follow up) ήταν κατά μέσο όρο 4,4 έτη (2-12). Οι ασθενείς αντιμετωπίσθηκαν με αναθεώρηση της αρθροπλαστικής σε ένα χρόνο (9 ασθενείς, 42,8%), επέμβαση τύπου Girdlestone (8 ασθενείς, 38,1%), χειρουργικό καθαρισμό και ροή-πλύση (3 ασθενείς, 14,3%) και αναθεώρηση της οστεοσύνθεσης με πλάκα-βίδες επί οστεοτομίας βράχυνσης του μηριαίου σε συγγενή πάθηση ισχίου (1 ασθενής, 4,7%). Ο μέσος όρος ηλικίας ήταν 63 έτη (42-78), με αναλογία άνδρες /γυναίκες 8:13. Aπαραίτητες προϋποθέσεις για να συμπεριληφθούν οι ασθενείς στη μελέτη ήταν: 1) Απουσία πιθανής εγκυμοσύνης, 2) Φυσιολογική νεφρική λειτουργία, 3) Μετεγχειρητικό διάστημα μετά την εμφύτευση της πρωτογενούς αρθροπλαστικής του ισχίου μεγαλύτερο από 12 μήνες, 4) Χρονικό διάστημα άνευ λήψεως αντιμικροβιακών φαρμάκων τουλάχιστον 3 εβδομάδων προ της διερεύνησης μέσω LeukoScan® και 5) Παθολογικά αυξημένες τιμές ταχύτητας καθίζησης ερυθρών αιμοσφαιρίων (ΤΚΕ) και C-αντιδρώσας πρωτεϊνης (CRP), επειδή οι φυσιολογικές τιμές ουσιαστικά αποκλείουν την πιθανότητα σηπτικής φλεγμονής επί αρθροπλαστικής ισχίου. Η επιλογή των ασθενών προς διαγνωστική διερεύνηση βασίσθηκε σε ένα «πρωτόκολλο παραγόντων κινδύνου» σε συνδυασμό με την κλινική υποψία της παρουσίας περιπροθετικής λοιμώξεως και σηπτικής χαλάρωσης. Ο έλεγχος των ασθενών περιελάμβανε κλινική αξιολόγηση (Harris Hip Score), κλασική ακτινολογική απεικόνιση και εργαστηριακές εξετάσεις αίματος (απόλυτος αριθμός λευκοκυττάρων, ποσοστιαία αναλογία πολυμορφοπυρήνων ουδετεροφίλων κοκκιοκυττάρων, ταχύτητα καθίζησης ερυθρών αιμοσφαιρίων και C-αντιδρώσα πρωτεϊνη). Κατά τη σπινθηρογραφική διερεύνηση, το 99mTc-Dynamic Bone Scan προηγήθηκε του LeukoScan® λόγω της υψηλής ευαισθησίας του ως προς την ανίχνευση φλεγμονωδών εστιών, το χαμηλό του κόστος και της ισχύουσας διαγνωστικής τακτικής σε αμφίβολες περιπτώσεις οστικής λοίμωξης. Tα ευρήματα του LeukoScan® διαβαθμίστηκαν σε 4 διακριτές κατηγορίες αποτελεσμάτων I-IV (I-άνευ αυξημένης καθήλωσης του ραδιοφαρμάκου, II-αυξημένη πρόσληψη στα μαλακά μόρια και φυσιολογική στο οστούν, III-ίση κατανομή σε μαλακά μόρια και οστούν, IV-μεγαλύτερη πρόσληψη στο οστούν ή μόνο σε αυτό). Οι κατηγορίες I και II αντιπροσωπεύουν αρνητικά LeukoScan®-αποτελέσματα, ενώ οι ΙΙΙ και ΙV θετικά αποτελέσματα. Ακολούθησε ιστοπαθολογική και μικροβιολογική εξέταση διεγχειρητικών δειγμάτων (αξιολογήθηκαν μόνο τα θετικά μικροβιολογικά αποτελέσματα) που ελήφθησαν από προκαθορισμένες περιοχές. Ιστοπαθολογικό κριτήριο περιπροθετικής σηπτικής φλεγμονής αποτέλεσε η ανεύρεση >5 ουδετερόφιλων πολυμορφοπυρήνων κοκκιο- κυττάρων κατά μέσο όρο για κάθε μεγάλο οπτικό πεδίο. Τα ευρήματα του LeukoScan® συσχετίσθηκαν με τα ιστοπαθολογικά και μικροβιολογικά αποτελέσματα και έγινε ονομαστική καταγραφή αληθών και λανθασμένων σπινθηρογραφικών διαγνώσεων. ΑΠΟΤΕΛΕΣΜΑΤΑ: Η προεγχειρητική αξιολόγηση των ασθενών ανέδειξε τους εξής μείζονες παράγοντες κινδύνου: Άλγος ισχίου ή/και άλγος μηρού (21 ασθενείς, 100%), παθολογικές εργαστηριακές εξετάσεις αίματος (21 ασθενείς, 100%), προηγηθείσες χειρουργικές επεμβάσεις (13 ασθενείς, 61,9%), λοίμωξη τραύματος του χειρουργημένου ισχίου (10 ασθενείς, 47,6%) και εστίες λοιμώξεως (9 ασθενείς, 42,8%). O προεγχειρητικός μέσος όρος του υπολογιζόμενου κλινικού Harris Hip Score ήταν 64 βαθμοί, από 28 έως 93 βαθμούς. Η ιστολογική και μικροβιολογική εξέταση των διεγχειρητικών δειγμάτων ανέδειξε την παρουσία περιπροθετικής λοίμωξης σε 17 αρθροπλαστικές, ενώ σε 4 αρθροπλαστικές δεν ανιχνεύθηκε σηπτική φλεγμονή. Η υπολογιζόμενη μέση τιμή των εργαστηριακών παραμέτρων φλεγμονής ήταν σχετικά με τον απόλυτο αριθμό λευκοκυττάρων 8,6 Κ/μl (3,9 – 14,5 Κ/μl), την ποσοστιαία αναλογία των πολυμορφοπυρήνων κοκκιοκυττάρων 64% (39 – 79%), την ταχύτητα καθίζησης ερυθρών αιμοσφαιρίων 56,3 mm (23 – 101 mm ) και την C-αντιδρώσα πρωτεϊνη 6,1 mg/dl (αρνητική τιμή – 40,5 mg/dl). Σε συνδυασμό με τα ιστολογικά και μικροβιολογικά ευρήματα προκύπτει για την ΤΚΕ ευαισθησία ίση με 1, ακρίβεια 0,8 και θετική προγνωστική αξία 0,8. Αντίστοιχα για την CRP προκύπτει ευαισθησία 0,94, ειδικότητα 0,25, ακρίβεια 0,8, θετική και αρνητική προγνωστική αξία 0,84 και 0,5 αντίστοιχα. Έγιναν 15 Dynamic Bone Scan εκ των οποίων 12 αληθώς θετικά, 1 αληθώς αρνητικό και 2 ψευδώς θετικά. Η σπινθηρογραφική διερεύνηση μέσω LeukoScan® που διενεργήθηκε σε 21 ασθενείς, ανέδειξε 17 αληθώς θετικά και 4 αληθώς αρνητικά αποτελέσματα. Στην κατηγορία-III ταξινομήθηκαν 7 θετικά και στην κατηγορία-IV 10 θετικά LeukoScan®. Στην κατηγορία-I ταξινομήθηκε 1 αρνητικό και στη κατηγορία-II 3 αρνητικά LeukoScan®. Από τη στατιστική ανάλυση προκύπτει για το σπινθηρογράφημα οστών τριών φάσεων ευαισθησία ίση με 1, ειδικότητα 0,33, ακρίβεια 0,86, θετική και αρνητική προγνωστική αξία 0,85 και 1 αντίστοιχα. Αντίστοιχα για το 99mTc- Sulesomab όλες οι στατιστικές παράμετροι είναι ίσες με 1. Σε τρεις ασθενείς διενεργήθηκε SPECT/CT-scan χωρίς επιπλέον χορήγηση ραδιοφαρμάκου, προς διερεύνηση της περιοχής των τροχαντήρων και ενισχύθηκε η ταξινόμηση των 99mTc-Sulesomab-ευρημάτων στην εκάστοτε κατηγορία. ΣΥΜΠΕΡΑΣΜΑ: Ακολουθώντας τον προτεινόμενο διαγνωστικό αλγόριθμο με τη σωστή επιλογή των ασθενών, το 99mTc-Sulesomab μπορεί να αποτελέσει σημαντική διαγνωστική επιλογή κατά τη διερεύνηση των σηπτικών φλεγμονών επί αρθροπλαστικών ισχίου, καθώς κάτω από τις παραπάνω προϋποθέσεις παρουσιάζει ευαισθησία, ειδικότητα, ακρίβεια, θετική και αρνητική προγνωστική αξία ίση με 1. Το SPECT/CT-scan προσφέρει διαγνωστικά όταν οι φλεγμονώδεις αλλοιώσεις εντοπίζονται πάνω από το όριο σώματος μηριαίας πρόθεσης-αυχένος μηριαίας πρόθεσης. / AIM: Nuclear Medicine can contribute in differential diagnosis of septic loosening of hip arthroplasty, when the clinical and laboratory findings are not clear. The aim of this study was to determine the ability of scintigraphy with 99mΤc–Sulesomab (LeukoScan®), to diagnose and localize periprosthetic septic lesions in patients with hip arthroplasty. MATERIALS AND METHODS: 21 patients with hip arthroplasty (12 cementless, 3 cemented, 2 hybrid, 3 bipolar total hip arthroplasties and 1 semiarthroplasty) were studied between 1/2001 up to 2/2004, for possible periprosthetic inflammation and septic loosening. The mean follow up period was 4,4 years (2-12). 9 patients (42,8%), were subjected in revision arthroplasty, 8 patients in Girdlestone procedure, 3 patients in surgical debridement and 1 patient, with congenital hip luxation who was primary subjected in femoral shortening osteotomy and fixation with plate and screws, in revision of the fixation. Then mean patient age was 63 years (42-78) and the male to female ratio was 8:13. All patients, in order to be evaluated, had to fulfill the following requirements: 1) absence of pregnancy, 2) normal renal function, 3) 12 months period after the implantation of the primary prosthesis, 4) 3 weeks period free of antibiotic therapy, before the investigation with Leukoscan and 5) abnormal high values of ESR and CRP, since normal values exclude septic loosening. Patients’ selection for diagnostic evaluation was based on a “high risk protocol” in combination with clinical suspicion of periprothetic infection and septic loosening. All patients were clinically evaluated using Harris Hip Score and were investigated with standard x-rays and blood tests, including total white cell number, percentage of neutrophile granulocytes, ESR and CRP. During scintigraphic studies, 99mTc-Dynamic Bone was done before LeukoScan®, because of its high sensitivity for detecting infectious areas, its low cost and the current diagnostic strategy for doubtful cases of bone infection. LeukoScan® findings were classified in four distinct categories I – IV (I – with normal radiopharmaceutical concentration, II – increased uptake in soft tissues and normal in bone, III – equal increased uptake in soft tissues and bone, IV – increased bony uptake). Categories I and II represent negative LeukoScan® findings, while III and IV were classified as positive. Histopathologic and microbiologic tests of intraoperative samples were done (only positive microbiologic tests were evaluated). Histopathologic criterion for periprothetic septic loosening was considered the finding of >5 neutrophile granulocytes per high energy field. LeukoScan® findings were matched with histopathologic and microbiologic results. RESULTS: Patients’ preoperative evaluation revealed the following risk factors: hip or thigh pain (21 patients, 100%), pathologic blood tests (21 patients, 100%), previous operations (13 patients, 61,9%), wound infection (10 patients, 47,6%) and other infectious regions (9 patients, 42,8%). Preoperative Harris Hip Score was 64 points (28 – 93). Histologic and microbiologic tests of intraoperative samples revealed periprothetic infection in 17 cases. Mean value of laboratory tests revealing infection with respect to total white cells number was 8,6 Κ/μl ( 3,9 – 14,5 Κ/μl ), percentage of neutrophile granulocytes 64% (39 – 79%), ESR 56,3 mm (23 – 101 mm) and CRP 6,1 mg/dl. ESR showed a sensitivity of 1, accuracy 0,8 and positive prognostic value 0,8. CRP had 0,94, 0,25 and 0,8 respective values, with positive prognostic value 0,84. 15 Dynamic Bone Scan were done, 12 were classified as positive, 1 true negative and 2 false positive. LeukoScan® were classified as 17 true positive and 4 true negative. 7 true positive tests were classified in category III and 10 in category IV. 1 negative LeukoScan® was classified in category I and 3 in category II. Dynamic Bone Scan showed a sensitivity 1, specificity 0,33, accuracy 0,86, positive and negative prognostic value 0,85 and 1 respectively. 99mTc-Sulesomab showed for all parameters value 1. CONCLUSIONS: Following the appropriate diagnostic algorithm and patient selection, 99mTc-Sulesomab can detect septic loosening, since it shows sensitivity, specificity, accuracy, positive and negative prognostic values of 1. SPECT/CT-scan offers significant diagnostic help when infection is localized above the neck of the femoral component.

Disregard for patient-specific joint-level variability may be related to decreased functional ability, poor implant longevity and dissatisfaction post-TKA. The purpose of this study was to, 1) compare pre and post-implant intraoperative passive knee adduction angle kinematic patterns and characterize the effect of surgical intervention on each pattern, 2) examine the association between passive pre and post-implant knee kinematics measured intraoperatively and dynamic knee kinematics and kinetics pre and post-TKA measured during gait, and 3) compare dynamic post-TKA kinematic and kinetic patterns between patient-specific knee recipients and traditional TKA recipient. Patients received a TKA using the Stryker Precision Knee navigation system capturing pre/post-implant kinematics through a passive range of flexion. One-week prior and 1-year post-TKA patients underwent three-dimensional gait analysis. Knee joint waveforms were calculated according to the joint coordinate system. Principal component analysis (PCA) was applied to frontal plane gait angles, moments and navigation angles. Paired two- tailed t-tests were used to compare principal component (PC) scores between pre and post-implant patterns, and a one-way ANOVA was used to test if post-implant patterns were significantly different from zero. Two-tailed Pearson correlation coefficients tested for associations between navigation and gait PCscores, and an un-paired two-tailed t-test was used to compare PCscores between patient-specific and traditional TKA groups. Six different passive kinematic phenotypes were captured pre-implant. Although some waveform patterns persisted at small magnitudes post-implant (PC1 and PC3: p<0.001), curves remained within the clinically acceptable alignment range through passive motion. A positive correlation was found between navigation adduction angle PC1 and gait adduction moment PC1 pre and post-TKA (p<0.001, r=0.79; p<0.01 r=0.67), and a negative correlation between navigation adduction angle PC1 and gait adduction angle PC1 post-TKA (p=0.03, r=-0.53). The patient-specific group showed significantly lower PC2 scores than the traditional TKA group (p=0.03), describing a lower flexion moment magnitude during early stance phase, possibly representing a functional limitation or non- confidence during gait. These results were an important first step to assess patient- specific approaches to TKA, suggesting possible applications for patient-specific intraoperative kinematics to aid in surgical decision-making and influence functional outcomes.

The "International Classification of Functioning, Disability and Health" (ICF) is a model that classifies health and health-related function. Of the ICF domains, least is known about participation. Although a few measures have been developed in English that tap the construct "Participation", none exist in Spanish. The Reintegration to Normal Living (RNL)-Index is the measure of reference to evaluate participation. The general objective of the present study was to translate, culturally adapt, and assess the psychometric properties the RNL-Index in Spanish for use in Spain. The translation and the cultural adaptation of the RNL-Index consisted of a five-step process, leading to the Spanish version of the RNL-Index (SRNL-Index). Psychometric evaluation consisted of a cross-sectional study design, with a longitudinal design used for test-retest evaluation. Thirty-two subjects with stroke and 36 with total knee arthroplasty completed the SRNL-Index twice, as well as the Six Minute Walk Test (6MWT), the Short-Form 36 Health Survey (SF-36), and for stroke subjects, the Barthel Index (BI). Descriptive statistics, one-way analysis of variance and post-hoc t tests were calculated, as well as Cronbach's alpha, Pearson's, and Intraclass correlation coefficients. The SRNL-Index was found to be internally consistent. Test-retest reliability was quite poor, being moderately low for the TKA sample and moderate for the stroke sample. Discriminant validity was demonstrated by the correlations between the SRNL-Index's Perception of Self and Daily Activity subscales with the Mental and Physical Component Summary scores of the SF-36. The SRNL-Index has convergent validity as shown by the high correlations between of the SRNL-Index and the 6MWT. Known-groups validity was shown in people with stroke grouped by Barthel Index scores, and in both samples when grouped according to gait speed. The SRNL-Index demonstrated acceptable validity and internal reliability for subjects with stroke and total knee arthroplasty. However, further studies are needed to reassess external validity, reliability, and responsiveness in other populations and other Spanish-speaking countries.

Background: Total hip replacement (THR) with post-operative surveillance is recommended for debilitating osteoarthritis (OA). Using self-reported pain, function or walking performance is one alternative to address increasing surveillance demands. Objective: A cross-sectional cohort study to evaluate the associations of pain, function and performance with two radiographic markers of potential THR failure. Participants: 110 patients, median 6 years after THR surgery for OA. Methods: Questionnaires assessed demographics, co-morbidity, arthritis severity, pain, pain catastrophizing, and functional status. Performance was measured using the six minute walk test. THR outcome was assessed radiographically. Results: Few patients had pain, functional impairment or radiographic markers of potential THR failure. A larger percentage of patients with some intermittent pain (10.7 versus 8.6%) and pain iii after walking performance (40.0 versus 27.6%) had higher wear, but these differences were not significant. Conclusion: Measures of pain are potentially important for larger studies aiming to develop alternative methods of post-operative surveillance.

Background: Total hip replacement (THR) with post-operative surveillance is recommended for debilitating osteoarthritis (OA). Using self-reported pain, function or walking performance is one alternative to address increasing surveillance demands. Objective: A cross-sectional cohort study to evaluate the associations of pain, function and performance with two radiographic markers of potential THR failure. Participants: 110 patients, median 6 years after THR surgery for OA. Methods: Questionnaires assessed demographics, co-morbidity, arthritis severity, pain, pain catastrophizing, and functional status. Performance was measured using the six minute walk test. THR outcome was assessed radiographically. Results: Few patients had pain, functional impairment or radiographic markers of potential THR failure. A larger percentage of patients with some intermittent pain (10.7 versus 8.6%) and pain iii after walking performance (40.0 versus 27.6%) had higher wear, but these differences were not significant. Conclusion: Measures of pain are potentially important for larger studies aiming to develop alternative methods of post-operative surveillance.

The most common cause for revision total hip replacement surgey is aseptic loosening of the acetabular component. This thesis explores the effect of three techniques to improve the depth and quality of cemented acetabular component fixation in primary total hip replacement. This may have beneficial effects on the longevity of cemented acetabular components and reduce the rate of revision surgery for aseptic loosening. Aims: 1. Determine the effect of the rim cutter on cement pressure during cup insertion. 2. Examine the effect of the rim cutter on cement penetration distance. 3. Evaluate the effect of bone grafting of the acetabular notch. 4. Determine the effect of iliac suction during cement pressurisation. 5. Compare the behaviour of bone cement with Play Dough. Materials and Methods: 1. Sawbones hemi pelvis models were fitted with pressure transducers at the rim and apex of the acetabulum. Peak pressure was measured upon insertion of cups with different flange sizes and when the acetabulum was prepared with the rim cutter. 2. Foam cavities were used to measure the depth of cement penetration when the same cups and rim cutter were used. 3. Hemi pelvis models were modified to simulate bone grafting of the acetabular notch. Again, pressure sensors were mounted at the apex and rim of the acetabulum. Intra-acetabular cement pressure was compared with native acetabulae. 4. A back bleeding model of the acetabulum was fitted with a suction catheter. The effect on cement penetration into cancellous bone was measured compared with no suction. 5. Play Dough pressurisation and penetration into hemi pelvises and foam was compared to bone cement. Results: 1. Significant increase in peak apex and rim pressures when flanged cup inserted into an acetabulum prepared with the rim cutter compared with both flanged and unflanged cups alone. 2. Significant increase in cement penetration at the rim of the acetabulum when rim cutter used and flanged cup inserted when compared with flanged and unflanged cups alone. 3. Significant increase in intra-acetabular pressure when cement pressurised in presence of simulated acetabular notch bone grafting compared with normal acetabulae. 4. Significant increase in cement penetration distance when suction used compared with no suction. 5. Significant differences in the flow characteristics between bone cement and Play Dough. Conclusion: The authors recommend preparation of the acetabular rim with the rim cutter and bone grafting of the acetabular notch to improve the depth and uniformity of the cement mantle in cemented primary THA. Play Dough at room temperature is not a suitable substitute for bone cement in in-vitro cementing studies.

Η αναθεώρηση μιας ολικής αρθροπλαστικής ισχίου λόγω χαλάρωσης του μηριαίου τμήματος της αποτελεί μια πρόκληση ακόμα και για πεπειραμένους χειρουργούς. Η άσηπτη χαλάρωση συνήθως σχετίζεται με κάποιο βαθμό οστικής απώλειας. Διερευνήσαμε εάν η πρόθεση Zweymüller SLR-Plus ®, μαζί με την βιολογική αναδόμηση με αλλομοσχεύματα του ελλειμματικού οστικού περιβάλλοντος του μηριαίου, θα επιτύγχανε επιβίωση, οστεοενσωμάτωση και σταθερότητα παρόμοια ή και καλύτερη από άλλες προθέσεις που χρησιμοποιούνται στη βιβλιογραφία για αναθεώρηση του μηριαίου τμήματος ΟΑΙ. Εξετάσαμε αναδρομικά 69 επιλεγμένους ασθενείς (70 ισχία) οι οποίοι υποβλήθηκαν σε αναθεώρηση του μηριαίου τμήματος με χρήση του SLR-Plus ® στειλεού σε μια περίοδο 10 ετών. Οι ενδείξεις για την αναθεώρηση περιελάμβαναν άσηπτη και σηπτική αποτυχία της βιολογικής στερέωσης, εσφαλμένη εμφύτευση, και περιπροθετικό κάταγμα. Επτά ασθενείς πέθαναν και τέσσερις χάθηκαν κατά το διάστημα παρακολούθησης. Πενήντα οκτώ από τους 69 ασθενείς (59 ισχία) ήταν διαθέσιμοι σε μέσο χρονικό διάστημα 8,3 ± 2,7 χρόνια (εύρος, 4-14 ετών) μετά τη χειρουργική επέμβαση αναθεώρησης. Υπήρχαν 14 άνδρες και 44 γυναίκες (μέση ηλικία, 69 έτη, εύρος, 42-89 ετών). Τέσσερις μηριαίες προθέσεις (7%) αναθεωρήθηκαν ξανά. Η 10ετής επιβίωση της πρόθεσης λαμβάνοντας ως αιτία αναθεώρησης την άσηπτη χαλάρωση ήταν 95% (95% C.I.: 86% -98%). Δεν παρατηρήθηκε περιπροθετική οστεόλυση του μηριαίου γύρω από την πρόθεση και 91% των SLR-Plus στειλεών εμφανίστηκε ακτινολογικά σταθερό είτε μέσω οστεοενσωμάτωσης είτε μέσω ινώδους στερέωσης. Με βάση τα στοιχεία επιβίωσης, πιστεύουμε ότι η χρήση του SLR-Plus® στειλεόυ είναι μια αξιόπιστη λύση για τους ασθενείς που υποβάλλονται σε χειρουργική επέμβαση αναθεώρησης ΟΑΙ, με απώλεια οστικής μάζας στο κεντρικό τμήμα του μηριαίου. / Revision after failed THA resulting from loosening of the femoral component can be challenging even for experienced surgeons. Aseptic loosening usually is associated with some degree of bone loss. We asked whether the Zweymüller SLR-Plus®, along with allograft reconstruction of the deficient femoral bone stock, would provide survivorship, osseointegration, and stability similar to or better than previously reported implants for femoral revision. We retrospectively reviewed 69 selected patients (70 hips) who underwent revision of the femoral component using the SLR-Plus® stem during a 10-year period. The indications for revision included aseptic and septic failure of biologic fixation, incorrect implantation, and periprosthetic fracture. Seven patients died and four were lost to followup. Fifty-eight of the 69 patients (59 hips) were available at a mean 8.3 ± 2.7 years (range, 4–14 years) after revision surgery. There were 14 men and 44 women (mean age, 69 years; range, 42–89 years). Four stems (7%) were rerevised. With rerevision for aseptic reasons, the survival at 10 years was 95% (95% confidence interval, 86%–98%). No femoral periprosthetic osteolysis occurred around the stem and 91% of stems appeared stable radiographically (osseointegration, fibrous). Based on the survival data, we believe the SLR-Plus® stems are reliable for patients undergoing hip revision surgery with central bone loss.