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Background The present study used a systematic review to analyse the risk of perioperative injections during arthroscopic reconstruction of the rotator cuff of the shoulder. The questions of interest were whether perioperative local injection increases the infection risk and whether the number of postoperative revisions is increased. Material and Methods A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The keywords used were “shoulder” and “arthroscopy” and “injection” and “risk”. In the course of the study, work that was not also primarily concerned with the reconstruction of the rotator cuff was excluded. English original articles and case series were included that contained at least some arthroscopic reconstructions of the rotator cuff. The risk of bias was determined using the Newcastle-Ottawa Scale. The content of the articles relevant to the research questions was analysed. Results 48 hits were primarily generated. 9 articles corresponded to the inclusion criteria and were analysed. In the 6 studies with details on the injected substances, cortisone was used in 98 – 100% of the cases. The reported infection and revision rates based on insurance data were higher with injection than without. The risk of bias in the studies analysed here was rather low based on the Newcastle-Ottawa Score. The risk of infection after a cortisone injection before, during or after surgery was increased. Injection was associated with infection in up to 8% of cases with injections within two weeks of surgery. The risk of infection was increased by up to 11 times with injections within 4 weeks after the operation. Likewise, the risk of revision surgery after injection was increased, with the time intervals between injection and surgery sometimes differing between studies. Discussion Local infections and to a lesser extent revision surgery are associated with perioperative injections (with cortisone) within 3 months preoperatively and 4 weeks postoperatively. However, there were only database studies of insurance data with several studies from a few centres. Thus, no causal relationships could be proven. Currently, however, the following can be recommended using a cautious approach: The interval between injection with cortisone before surgery should be at least 2 weeks, better 3 months. No cortisone injections should be applied intraoperatively. Postoperatively, cortisone should not be injected for at least 4 weeks. If, in exceptional cases, deviations from these time limits are required, patients should be informed about an increased risk of complications.

The suprascapular nerve can be compromised as a result of a compression syndrome in different locations. A (proximal) compression within the scapular notch can lead to dorsal shoulder pain and simultaneous weakness of the infraspinatus and supraspinatus muscles. By transection of the lig. transversum this compression syndrome can be treated. By means of a systematic review, the present work analyzes the motor recovery potential after arthroscopic decompression.A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The search words used were "suprascapular" and "arthroscopic"; "suprascapular" and "arthroscopy". Based on the evaluated literature, articles in English with at least a partial arthroscopic case series from 4 cases on and a compression syndrome of the suprascapular nerve treated with arthroscopic decompression in the scapular notch were identified. Motor recovery was described by means of EMG, clinical strength and MRI.Primarily 408 hits were generated. Six articles met the inclusion criteria and were further analyzed. The number of arthroscopic cases was between 4 and a maximum of 27. The level of evidence was between III and IV. The majority of the reported clinical results were good. Motor recovery as measured by EMG was observed, recovery of full strength was not achieved in the majority of reported cases (60%), neither was regression of structural (fatty) degeneration of the muscle bellies.Arthroscopic decompression of the suprascapular nerve in the scapular notch provides good clinical results and considerable pain relief. However, in the majority of cases it does not lead to a complete recovery of the strength of the supra- and infraspinatus muscles. Patients should be informed about this. An early decompression after diagnosis in the event of proximal compression within the suprascapular notch combined with beginning EMG or MRI changes appears reasonable. These beginning changes should be further defined. Future studies should develop prognostic criteria for motor recovery. Awareness regarding the diagnosis needs to be improved due to the probably time-dependent irreversibility of resulting muscular weakness.Der N. suprascapularis kann in seinem Verlauf an verschiedenen Stellen komprimiert werden. Ein (proximales) Kompressionssyndrom spezifisch in der Incisura scapulae führt häufig zu dorsalen Schulterschmerzen und zu einer simultanen Kraftabschwächung des Infraspinatus- und Supraspinatusmuskels. Durch Durchtrennung des Lig. transversum kann dieses Kompressionssyndrom behandelt werden. Die vorliegende Arbeit analysiert durch einen systematischen Review das motorische Erholungspotenzial nach arthroskopischer Dekompression.Es wurde eine systematische Durchsicht der Datenbank der U. S. National Library of Medicine/National Institutes of Health (PubMed) und der Cochrane Library unter Anwendung der PRISMA-Checkliste durchgeführt. Als Suchwörter dienten „suprascapular“ und „arthroscopic“; „suprascapular“ und „arthroscopy“. Anhand der evaluierten Literatur wurden Artikel mit zumindest anteiligen arthroskopischen Fallserien ab 4 Fällen bei Kompressionssyndrom mit einer arthroskopischen Dekompression des N. suprascapularis in der Incisura scapulae in englischer Sprache identifiziert. Eine motorische Erholung des Nervs wurde beschrieben anhand von EMG, klinischem Kraftgrad und MRT.Es wurden primär 408 Treffer generiert. Sechs Artikel entsprachen den Einschlusskriterien und wurden weitergehend inhaltlich analysiert. Die arthroskopische Fallzahl lag zwischen 4 und maximal 27. Der Evidenzlevel lag zwischen III und IV. Die berichteten klinischen Ergebnisse waren mehrheitlich gut. Eine motorische Erholung, gemessen mittels EMG, wurde beobachtet, eine Wiedererlangung des vollständigen Kraftgrades in der Mehrzahl der berichteten Fälle nicht (60%), eine Rückbildung von strukturellen (fettigen) Degenerationen der Muskelbäuche ebenso wenig.Die arthroskopische Dekompression des N. suprascapularis in der Incisura scapulae sorgt für klinisch gute Ergebnisse und erhebliche Schmerzerleichterung. Sie führt in der Mehrzahl der Fälle aber nicht zu einer kompletten Erholung des Kraftgrades der Supra- und Infraspinatusmuskulatur. Hierüber sollten Patienten aufgeklärt werden. Eine frühe Dekompression bei klinischer Diagnose bei proximaler Kompression in der Incisura scapulae und leichten Veränderungen im EMG oder MRT erscheint sinnvoll. Diese beginnenden Veränderungen sollten weiter definiert werden. Zukünftige Studien sollten zudem prognostische Kriterien für das Erholungspotenzial des N. suprascapularis entwickeln. Die Awareness hinsichtlich der Diagnose muss wegen der wahrscheinlich zeitabhängigen Irreversibilität der Muskelschwäche erhöht werden.

Intratendinous lesions of the rotator cuff of the shoulder are frequent and may be a distinct clinical entity. Nevertheless, there are only a few publications which deal specifically with this subject. This study analyses the existing literature for the arthroscopic reconstruction of the intratendinous lesion of the supraspinatus tendon, by means of a systematic review, and identifies relevant research questions for future studies.In January 2017, a systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) Database and the Cochrane Library was conducted using the PRISMA checklist. The search words were "supraspinatus" and "interstitial"; "supraspinatus", "tear" and "intratendinous"; "supraspinatus" and "concealed". In the course of the review, articles written in English with at least a partial arthroscopic case series dealing with the reconstruction of the supraspinatus tendon were identified and further analysed.Primarily 70 hits could be generated. Five articles met the inclusion criteria and were analysed in detail. The number of arthroscopic cases ranged between 6 and 33. Level of evidence was IV in all studies. The diagnosis of an intratendinous lesion was made by MR imaging when T2/fat-saturated sequences showed an intratendinous high intensity signal without disruption of the bursal or articular layer. Three different concepts were followed in surgical treatment: opening of the intratendinous lesion from the bursal or articular side or by complete resection of the lesion. The reconstruction was performed with suture anchors in all cases. In the majority of cases, an acromioplasty was also performed. The reported clinical results were mostly good. Healing of the tendon was shown by MR imaging in 81.5 to 100% of cases.After failure of conservative treatment, symptomatic intratendinous lesions of the supraspinatus tendon can be localised intraoperatively and reconstructed after failure of conservative treatment. The expected results are good in the medium term. The evidence level of the studies analysed was low. Future studies should examine the role of alternative conservative and surgical therapies.Intratendinöse Läsionen der Rotatorenmanschette der Schulter treten in relevanter Fallzahl auf und stellen möglichweise eine eigene klinische Entität dar. Dennoch gibt es bislang wenig Fachliteratur, die sich spezifisch hiermit beschäftigt. Die hier vorliegende Arbeit analysiert anhand eines systematischen Reviews die vorhandene Fachliteratur zur arthroskopischen Rekonstruktion der intratendinösen Läsion der Supraspinatussehne und ermittelt relevante Forschungsfragen für zukünftige Studien.Im Januar 2017 wurde eine systematische Durchsicht der Datenbank U. S. National Library of Medicine/National Institutes of Health (PubMed) und der Cochrane Library unter Anwendung der PRISMA-Checkliste durchgeführt. Als Suchwörter dienten „supraspinatus“ und „interstitial“; „supraspinatus“, „tear“ und „intratendinous“; „supraspinatus“ und „concealed“. Anhand der Durchsicht der gefundenen Literatur wurden Artikel mit zumindest anteiligen arthroskopischen Fallserien mit einer Rekonstruktion der Supraspinatussehne in englischer Sprache identifiziert.Es konnten primär 70 Treffer generiert werden. Fünf Artikel entsprachen den Einschlusskriterien und wurden weitergehend inhaltlich analysiert. Die arthroskopische Fallzahl lag zwischen 6 und 33. Die Evidenz betrug ohne Ausnahme Level IV. Die Diagnose wurde kernspintomografisch gestellt, wenn eine intratendinöse Signalanhebung in der Supraspinatussehne in T2-/fettgesättigten Sequenzen ohne Durchbrechung nach bursal oder artikulär zu erkennen war. Drei verschiedene Konzepte wurden in der operativen Behandlung verfolgt: Eröffnung der intratendinösen Läsion von bursal, von artikulär oder Eröffnung durch komplette Resektion des betroffenen Sehnenanteils. Die Rekonstruktion erfolgte jeweils mit Fadenankern. In der Mehrzahl der Fälle wurde zusätzlich eine Akromioplastik durchgeführt. Die berichteten klinischen Ergebnisse waren mehrheitlich gut. Kernspintomografisch gesicherte Einheilungsquoten lagen zwischen 81,5 und 100%.Symptomatische und therapierefraktäre intratendinöse Läsionen der Supraspinatussehne können intraoperativ lokalisiert und rekonstruiert werden. Die zu erwartenden Ergebnisse sind mittelfristig gut. Der Evidenzlevel der analysierten Studien war für das Fachgebiet niedrig. Zukünftige Studien sollten die Rolle alternativer konservativer und operativer Therapieansätze untersuchen.

Background The anterior deltopectoral approach is the standard approach for performing the open Latarjet procedure. Through the use of a more medial and vertical skin incision, the scar can be cosmetically covered by the bra strap in women. We call this incision the bra strap incision. The intention of this study was (1) to elaborate if the bra strap incision is considered beneficial by female patients, (2) to find reproducible landmarks to indicate how the bra strap incision has to be oriented, and (3) to evaluate preliminary clinical results of patients in whom the bra strap incision was used. Methods In 18 patients with a mean follow-up of 21 (range, 12–31) months treated with an open Latarjet procedure through the bra strap incision, the clinical results (scar satisfaction, Constant and Murley score [CMS], and subjective shoulder value [SSV]) were retrospectively analyzed. To assess the typical course of the bra strap, anatomical landmarks were assessed in 100 consecutive female patients as the distance from the bra strap center to (1) the tip of the coracoid process, (2) the superior end of the anterior axillary fold, and (3) the acromioclavicular joint. Results All (18 of 18) patients stated that they would prefer the bra strap incision if the same procedure had to be performed on the opposite shoulder; 16 women were satisfied with the scar. The mean CMS was 83 (range 64–96) points and the mean SSV was 85 (range, 60–100) %. The mean distances from the bra strap center to the acromioclavicular joint, coracoid tip, and axillary fold were 28 (range, 5–60) mm, 15 (range, 2–17) mm, and 30 (range, 2–55) mm. No combination of distance measures and demographic variable revealed a linear relationship. Conclusion This analysis shows that the bra strap incision appears to be highly welcomed by female patients and does not compromise the clinical outcome, when compared to previously published data. However, even though the typical location of the bra strap can be determined, the large variations in the distances make it more preferable to preoperatively mark the incision for optimal placement. Trial registration The study is approved by the Ethical Committee Zurich. (Cantonal Ethical Committee number: ZH-Nr.2017–00891).

To analyse the current scientific evidence regarding the natural history of the clinical and anatomical progression of rotator cuff tears. A broad systematic review of the literature (PubMed database through January 2014) which was guided, conducted and reported according to PRISMA criteria. This article focuses on the rotator cuff tears. Articles had to meet an inclusion criteria. The methodological quality of each study was individually assessed using a recently developed general assessment tool AMQPP (assessing the methodological quality of published papers). Seven articles dealing with rotator cuff tears were included, one of them was a high-quality study. Three papers assessed the natural history and the natural course of rotator cuff rupture directly. The other studies indirectly assessed the natural history with reports on non-operative and operative therapy trends. All of these articles had been published in four different top medical journals according to 2013 ranking. We found no articles which clearly referred to the role of regression to the mean of rotator cuff tears. The development of symptoms and anatomical deterioration are often directly correlated. Spontaneous recovery to normal levels of function has been successfully achieved, and standardised non-operative treatment programmes are an effective alternative to surgery for many patients. Follow-up is necessary to avoid irreparable stage. However, surgery is still favoured by young active people and highly professional persons who need to get fit in a short period of time. Further research is still necessary. The AMQPP score system is simple and reliable. It works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily.

The expected duration of incapacity after arthroscopic shoulder surgery is an important factor for therapy planning. The aim of this study was to analyze the duration of sick leave after arthroscopic shoulder surgery in Germany and to identify factors associated with a longer duration of sick leave. We hypothesized that certain patient-related factors may be associated with a longer duration of sick leave. Routine health care data of all patients insured by one German health insurance company who underwent inpatient arthroscopic shoulder surgery between 2010 and 2012 were included in the analysis of the duration of sick leave in this retrospective cohort study (level III evidence). Comparisons were performed for different arthroscopic surgical procedures using the log-rank test. Possible factors that might be associated with a longer duration of incapacity were analyzed. Sick leave was reported in 303 of 660 cases. The median duration of sick leave was 82 days after subacromial decompression and 157 days after rotator cuff repair (p = 0.004). The duration of sick leave was longer in patients older than 50 years (p = 0.044) and in patients with sick leave that started prior to surgery (p

Correct alignment of the rotation of the femoral component and the flexion gap after total knee arthroplasty is difficult in patients with preoperative leg axis deviation. Inaccuracy may result in problems with the patellofemoral joint and instability, in particular. We examined the influence of the preoperative leg axis on the rotation of the femoral component and the symmetry of the flexion gap after total knee arthroplasty using the tibial-cut-first technique. A retrospective study was carried out of 58 consecutive patients who underwent primary LCS total knee arthroplasty using the tibial-cut-first technique in 2008 based on preoperative full-leg radiographs and the final radiographs taken according to Kanekasu’s technique. The patients were divided into three groups (varus–valgus–neutral) according to their preoperative leg axis. Using the tibial-cut-first technique, a mean neutral rotation of the femoral component of 0.5° and a mean symmetrical flexion gap of −0.7° were achieved. Nevertheless, there was a positive correlation of the preoperative leg axis with the rotation of the femoral component. The differences in the rotation of the femoral component and the flexion gap between the three groups were not significant. The only significant difference between the varus and valgus groups was the extent of rotation of the femoral component, with a slightly greater external rotation of 2.7° in the valgus group. This study suggests that it is possible to achieve correct rotational alignment of the femoral component and a symmetrical flexion gap using the tibial-cut-first technique in patients with a preoperatively deviated leg axis. Therapeutic, Level III.

Particle-induced osteolysis is the most frequent cause of aseptic loosening after total joint replacement. We performed a study to illuminate the effect of ceramic particles with different diameters and concentrations on the mRNA expression of certain key regulators in particle-induced aseptic osteolysis (RANK, RANKL, OPG, and TNF-alpha) in THP-1 macrophage-like cells. Titanium particles were used as a positive control. RNA was analyzed by quantitative RTPCR. Our results demonstrate that alumina ceramic particles, regardless of particle size, caused only slight upregulations of RANK, TNF-alpha, and OPG mRNA, whose levels were significantly lower in comparison with those of titanium particles (p < 0.05). The continuous increasing tendency to time and particle-dependent mRNA expression of all the parameters stimulated by titanium particles was not found after stimulation with ceramic materials. Even after the concentration of ceramic particles was increased, only a mild upregulation of mRNA expression was found. Furthermore, we observed that the bioinert properties of ceramic particles did not change much in diameters ranging from 0.5 to 1.5 microm. At most of the measuring time points, there was no significant difference between the reactions of the large and small particles in this range. Our results support the theory about the relative bioinert properties of alumina ceramic particles.

BackgroundSerious injuries due to breakdancing have been presented only as singular case reports to date. So far, there have been no comprehensive studies about injuries in this sport.HypothesisProfessional breakdancing might lead to a higher incidence of injuries than amateur training. Wearing safety equipment is correlated with a decreased incidence of injuries and pain.Study DesignDescriptive epidemiology study.MethodsThe retrospective study surveyed 40 breakdance professionals and 104 amateurs by questionnaire.ResultsThere were 1665 injuries and 206 overuse syndromes found in 380 588 hours of training, leading to a loss of 10 970.6 training days. Professionals reported significantly ( P < .001) more injuries and overuse syndromes with significantly more injuries of the wrist ( P < .001), knee ( P < .001), hip/thigh ( P = .003), ankle/foot ( P = .013), and elbow ( P = .033). No significant differences were found in the time lost per injury and the time lost per overuse syndrome. Pain occurred most frequently in the region of the wrist, spine, shoulder, and ankle. A negative correlation between protective gear and injuries or frequency of pain could not be shown.ConclusionBreakdancing must be considered as a potentially high-risk dancing sport. Even with severe injuries, dancers interrupt training only for limited periods of time.Clinical RelevanceBreakdance injuries and overuse should not be underestimated. Physicians should be aware of the common risks in this highly acrobatic kind of dancing.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. While the osteolytic cascade initiated by cytokine release from macrophages has been studied extensively, the involvement of T-lymphocytes in this context is controversial and has been addressed by only a few authors. In a former study we detected that the quantity of T-lymphocytes may be influenced by apoptosis in patients with aseptic loosening. In this study we intended to find out more details about the apoptosis-induced shifting of the T-cell number. We focused our interest on the CD4⁺ and CD8 ⁺ T-cells and their relative ratio. Caspase-3 cleaved was evaluated immunohistochemically to detect apoptotic T-cells in capsules and interface membranes from patients with aseptic hip implant loosening and a varying degree of caspase-3 cleaved expression in CD4⁺ and CD8⁺ T-lymphocytes was detected. Moreover, a relationship between the intensity of the apoptotic reactions and the radiological extent of osteolysis was observed. The number of CD4⁺ cells was decreased in the presence of strong apoptotic reactions, respectively extensive osteolysis, while CD8⁺ cells were affected to a much lower degree. Thus, the CD4⁺/CD8 ⁺ ratio changed from 1.0 in cases with only small areas of periprosthetic osteolysis and minimally intense apoptosis to 0.33 in cases with large areas of osteolysis. This may suggest a causal relationship between the apoptosis-induced shift in the CD4⁺/CD8⁺ ratio and the osteolysis respectively aseptic loosening. It is possible that these findings may lead to a new understanding of particle-induced osteolysis. © Ivyspring International Publisher. All rights reserved.

A considerable number of patients complain about pain after lumbar surgery. The spinal dura mater has been debated as a possible source of this pain. However, there is no information if laminectomy influences the nociceptive sensory innervation of the dura. Therefore, we quantitatively evaluated the density of SP- and CGRP-immunopositive nerve fibers in the dura mater lumbalis in an animal model of laminectomy. Twelve adult Lewis rats underwent laminectomy, in six of them the exposed dura was covered by an autologous fat graft. Further six animals without surgical treatment served as controls. Six weeks after surgery, the animals were perfused and the lumbar dura was processed immunohistochemically for the detection of CGRP- and SP-containing nerve fibers. In controls, the peptidergic nerve fibers were found predominantly in the ventral but rarely in the dorsal dura mater lumbalis. After laminectomy, the density of SP- and CGRP-immunopositive neurons significantly increased in ventral as well as in dorsal parts of the dura. Axonal spines could be observed in some cases at the site of laminectomy. The application of autologous fat grafts failed to inhibit the significant increase in the density of peptidergic afferents. Thus, we have provided the first evidence that laminectomies induce an increase in the density of putative nociceptive SP- and CGRP-immunopositive neurons in the lumbar dura mater ascribable to an axonal sprouting of fine nerve fibers. This effect was not prevented by using autologous fat grafts. It is conceivable that the neuronal outgrowth of nociceptive afferents is a cause of low back pain observed after lumbar surgery.

Objective: It is known that bone mineral density (BMD) and the strength of bone is predicted by body mass. Fat mass is a significant predictor of bone mineral density which correlates with body weight. This suggests that body fat regulates bone metabolism first by means of hormonal factors and second that the effects of muscle and loading are signaling factors in mechanotransduction. Leptin, a peptide hormone produced predominantly by white fat cells, is one of these hormonal factors. The aim of this study was to investigate and measure by micro-CT the different effects of weight-bearing on trabecular bone formation in mice without the stimulation of leptin. Results: Animals with an ad-libitum-diet (Group A) were found to increase body weight significantly at the age of six weeks in comparison with lean mice (Group B). From this point on, the difference increased constantly. At the age of twenty weeks the obese mice were almost twice as heavy as the lean mice. Significant statistical differences are shown between the two groups for body weight and bone mineral density. Examination of trabecular bone (BV/TV, trabecular number (Tb.N.), trabecular thickness (Tb.Th.)) revealed that the only statistically significant difference between the two groups was the Tb.N. for the proximal femur. High weight-bearing insignificantly improved all trabecular bone parameters in the obese mice. Compared with the control-diet Group B, the BV/TV and Tb.N. were slightly higher in the controlled-diet Group A, but not the Tb.Th.. However, correlation was found between Tb.N. and BMD on the one hand and body weight on the other hand. Conclusion: biomechanical loading led to decreased bone mineral density by a decrease in the number of trabeculae. Trabecular thickness was not increased by biomechanical loading in growing mice. Decreased body weight in leptin-deficient mice protects against bone loss. This finding is consistent with the principle of light-weight construction of bone. Differences in cortical and trabecular bone will be examined in later studies. It is not possible to conclude that these results also apply to human beings.

Objective: It is known that bone mineral density (BMD) and the strength of bone is predicted by body mass. Fat mass is a significant predictor of bone mineral density which correlates with body weight. This suggests that body fat regulates bone metabolism first by means of hormonal factors and second that the effects of muscle and loading are signaling factors in mechanotransduction. Leptin, a peptide hormone produced predominantly by white fat cells, is one of these hormonal factors. The aim of this study was to investigate and measure by micro-CT the different effects of weight-bearing on trabecular bone formation in mice without the stimulation of leptin. Results: Animals with an ad-libitum-diet (Group A) were found to increase body weight significantly at the age of six weeks in comparison with lean mice (Group B). From this point on, the difference increased constantly. At the age of twenty weeks the obese mice were almost twice as heavy as the lean mice. Significant statistical differences are shown between the two groups for body weight and bone mineral density. Examination of trabecular bone (BV/TV, trabecular number (Tb.N.), trabecular thickness (Tb.Th.)) revealed that the only statistically significant difference between the two groups was the Tb.N. for the proximal femur. High weight-bearing insignificantly improved all trabecular bone parameters in the obese mice. Compared with the control-diet Group B, the BV/TV and Tb.N. were slightly higher in the controlled-diet Group A, but not the Tb.Th.. However, correlation was found between Tb.N. and BMD on the one hand and body weight on the other hand. Conclusion: biomechanical loading led to decreased bone mineral density by a decrease in the number of trabeculae. Trabecular thickness was not increased by biomechanical loading in growing mice. Decreased body weight in leptin-deficient mice protects against bone loss. This finding is consistent with the principle of light-weight construction of bone. Differences in cortical and trabecular bone will be examined in later studies. It is not possible to conclude that these results also apply to human beings.

In 40 patients undergoing total hip arthroplasty with the Mayo femoral stem we studied how preoperative digital templating corresponded to the actual intraoperative choice of implant size, position, offset and restoration of leg length.The preoperatively planned sizes of the components showed a high rate of coincidence with the sizes used intraoperatively [Intraclass Correlation Coefficient (ICC) 0.661-0.810]. However, the agreements in offset and CCD correction were poor (ICC 0.476, 0.253). This could be statistically attributed to the change in the distance from the medial margin of the stem to the medial margin of the medial femoral cortex and the height of osteotomy. The agreement in leg length correction was moderate (ICC 0.583), which was attributed to the change in the hip rotation center and the height of osteotomy.Careful preoperative planning was useful for accurate size choice of the Mayo prosthesis. Factors such as the height of osteotomy and the distance from the medial margin of the stem to the medial margin of the medial femoral cortex in relation to the position of the Mayo stem should be taken into account in order to restore ideal offset and leg length.

Small-animal models are useful for the in vivo study of particle-induced osteolysis, the most frequent cause of aseptic loosening after total joint replacement. Microstructural changes associated with particle-induced osteolysis have been extensively explored using two-dimensional (2D) techniques. However, relatively little is known regarding the 3D dynamic microstructure of particle-induced osteolysis. Therefore, we tested micro-computed tomography (micro-CT) as a novel tool for 3D analysis of wear debris-mediated osteolysis in a small-animal model of particle-induced osteolysis. The murine calvarial model based on polyethylene particles was utilized in 14 C57BL/J6 mice randomly divided into two groups. Group 1 received sham surgery, and group 2 was treated with polyethylene particles. We performed 3D micro-CT analysis and histological assessment. Various bone morphometric parameters were assessed. Regression was used to examine the relation between the results achieved by the two methods. Micro-CT analysis provides a fully automated means to quantify bone destruction in a mouse model of particle-induced osteolysis. This method revealed that the osteolytic lesions in calvaria in the experimental group were affected irregularly compared to the rather even distribution of osteolysis in the control group. This is an observation which would have been missed if histomorphometric analysis only had been performed, leading to false assessment of the actual situation. These irregularities seen by micro-CT analysis provide new insight into individual bone changes which might otherwise be overlooked by histological analysis and can be used as baseline information on which future studies can be designed.

In revision hip replacement surgery cortical strut grafts made of allograft bone are used to augment femoral bone stock and to fix periprosthetic femoral fractures. These struts are made from femoral bone as hemi-cylinders and are fixed to host bone with cerclage wires. We developed an artificial bone substitute for such strut grafts in order to overcome availability restrictions and potential infectious hazards with allograft bone. The partially biodegradable implant consists of a functionally-graded combination of titanium, polylactide, hydroxyapatite, and calcium carbonate. It is made by manual dip-coating of the metal (after chemical surface treatment) into solutions of polylactide with suspended calcium salts. In this way the titanium core is surrounded by an inner layer of slowly biodegradable poly(L-lactide) with calcium carbonate. The part of the implant that is in contact with the bone consists of rapidly biodegradable poly(D,L-lactide), hydroxyapatite and calcium carbonate. This method leads to an implant which is easily adaptable before the implantation to the geometry of the patient's bone when moderately heated (70 degrees C), but has a sufficient mechanical strength to serve as support under physiologic temperatures. The implant is mechanically stable, biocompatible, partially biodegradable, and provides a scaffold for growing bone.

To evaluate the current status of scientific research on the natural history of frozen shoulder as published in the literature. This systematic review was carried out on PubMed data and was guided by PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Articles had to meet inclusion criteria. The quality of the papers was assessed using a newly developed tool, AMQPP (Assessing the Methodological Quality of Published Papers). The AMQPP score was correlated with the level of evidence rating according to the Oxford Centre for Evidence-Based Medicine. Suitable papers were divided into groups according to the shoulder condition on which they reported. This article focuses on the frozen shoulder. Seven articles on frozen shoulder met the inclusion criteria. One article was considered to have level 1 of evidence. Three articles had level 3 and the remaining 3 had level 4. Three papers assessed the natural history and the natural course of different forms of stiff shoulder. The others indirectly assessed the natural history by evaluating therapy trends. None of the articles clearly referred to the role of regression to the mean of frozen shoulder specifically. Spontaneous recovery to normal levels of function is possible and standardised non-operative treatment programmes are an effective alternative to surgery in most cases. However, patients with high risk factors such as diabetes mellitus, and those who suffer chronic symptoms or bilaterally affected, would benefit from early surgery. We also concluded that AMQPP score is simple and straight forward. It works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily. The AMQPP score is still open for further development.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The possible induction of apoptosis has not been addressed in great detail. Thus far, it has been shown that ceramic and polyethylene particles can induce apoptosis of macrophages in vitro. The purpose of this study was to test the hypothesis that wears debris generated from total hip arthroplasty could induce cellular damage and apoptosis in vivo. We therefore determined by immunohistochemical methods if increased expression of p53, an important transcription factor, and BAK and Bcl-2, two important regulators of apoptosis, can be found in interface membranes and capsules of hips with aseptically loose implants. Strongly positive immunohistochemical staining for p53 and BAK was found in peri-implant tissues from patients with aseptic hip implant loosening. Differentiation of various cell types showed that macrophages stained positive for p53 in all capsule and interface specimens. p53 was frequently detected in giant cells. Positive staining of BAK in macrophages and giant cells was seen in all specimens. Some positive reactions were observed in fibroblasts, only two of 19 cases stained for p53 and three cases for BAK within synovial cells. Positive macrophages and giant cells were localized around polyethylene particles. While T-lymphocytes showed a regular BAK-staining, the other leukocytes were negative. Statistical analyses showed significant positive correlations (p < 0.001) between the presence of polyethylene and metal debris and the expression of BAK and p53. Polyethylene particles were surrounded by more positive macrophages and giant cells than were metal particles, indicating that polyethylene debris may be a stronger inductor of cell cycle arrest and apoptosis than metal debris. In this study apoptosis of macrophages, giant cells and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening has been demonstrated in vivo. It is possible that the apoptotic cascade could evolve as a novel therapeutic target to prevent particle-induced osteolysis.

Background: It has been postulated that use of a larger femoral head could reduce the risk of dislocation after total hip arthroplasty, but only limited clinical data have been presented as proof of this hypothesis. Methods: From 1969 to 1999, 21,047 primary total hip arthroplasties with varying femoral head sizes were performed at one institution. Patients routinely were followed at defined intervals and were specifically queried about dislocation. The operative approach was anterolateral in 9155 arthroplasties, posterolateral in 3646, and transtrochanteric in 8246. The femoral head diameter was 22 mm in 8691 of the procedures, 28 mm in 8797, and 32 mm in 3559. Results: One or more dislocations occurred in 868 of the 21,047 hips. The cumulative risk of first-time dislocation was 2.2% at one year, 3.0% at five years, 3.8% at ten years, and 6.0% at twenty years. The cumulative ten-year rate of dislocation was 3.1% following anterolateral approaches, 3.4% following transtrochanteric approaches, and 6.9% following posterolateral approaches. The cumulative ten-year rate of dislocation was 3.8% for 22-mm-diameter femoral heads, 3.0% for 28-mm heads, and 2.4% for 32-mm heads in hips treated with an anterolateral approach; 3.5% for 22-mm heads, 3.5% for 28-mm heads, and 2.8% for 32-mm heads in hips treated with a transtrochanteric approach; and 12.1% for 22-mm heads, 6.9% for 28-mm heads, and 3.8% for 32-mm heads in hips treated with a posterolateral approach. Multivariate analysis showed the relative risk of dislocation to be 1.7 for 22-mm compared with 32-mm heads and 1.3 for 28-mm compared with 32-mm heads. Conclusions: In total hip arthroplasty, a larger femoral head diameter was associated with a lower long-term cumulative risk of dislocation. The femoral head diameter had an effect in association with all operative approaches, but the effect was greatest in association with the posterolateral approach. Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

The most common cause of implant failure in joint replacement is aseptic loosening due to particle-induced osteolysis. Bisphosphonates have been shown to be effective against particle-induced osteolysis when administered daily. We investigated the effect of a single subcutaneous dose of a more potent third generation bisphosphonate on particle-induced osteolysis. We utilized the murine calvaria osteolysis model in C57BL/J6 mice. Bone resorption was measured as resorption within the midline suture using Giemsa staining. Twenty-eight mice were used, seven per group. Seven animals were treated with a single dose of zoledronic acid (ZA) directly after surgery and seven animals were treated four days postoperatively. For statistical analysis one-way ANOVA and a Student's t-test were used. Bone resorption was 0.26+/-0.09 mm(2) in animals with particle implantation, 0.14+/-0.05 mm(2) in animals with particle implantation and ZA treatment directly after surgery (p = 0.0047), and 0.15+/-0.05 mm(2) in animals with particle implantation and ZA treatment on the fourth postoperative day (p = 0.006). In conclusion, particle-induced bone resorption was markedly decreased by a single s.c. dose of a third generation bisphosphonate. This important new finding holds great promise, because single dose treatment of particle-induced osteolysis may reduce side effects compared to repeated application of bisphosphonates.

Bearing surface wear and periprosthetic osteolysis due to wear particles are among the most common reasons for joint replacement failure. A murine calvarial model of wear particle-induced osteolysis has been used to identify different biologic factors associated with this problem and to test nonsurgical methods of modulating the host response to particulate debris. This model has utilized titanium particles, however, in clinical practice the most common source of particulate debris is polyethylene particles from bearing surface wear. We now report a calvarial model of wear particle-induced osteolysis based on commercially available polyethylene particles. We found that compared to sham surgery osteoclast recruitment and bone resorption can be induced by introduction of the titanium particles or polyethylene particles. However, bone resorption was significantly higher with polyethylene particles compared to titanium particles (p=0.02). We consider the polyethylene based murine calvarial model of wear particle-induced osteolysis a reliable and clinically relevant tool to understand the host factors and potential pharmacologic interventions that can influence wear debris generated osteolysis. This model might serve as an extension of the well-established titanium based bone resorption model.

Background: A widely variable prevalence of dislocation after total hip arthroplasty has been reported, partly because of varying durations of follow-up for this specific end-point. The effect of demographic factors on the long-term risk of dislocation as a function of time after total hip arthroplasty is not well understood. The purpose of the present study was to determine the risk of dislocation as a function of time after Charnley total hip arthroplasty and to investigate the demographic factors that influence the cumulative risk of dislocation. Methods: Six thousand six hundred and twenty-three consecutive primary Charnley total hip arthroplasties were performed in 5459 patients at one institution between 1969 and 1984. The patients included 2869 female patients and 2590 male patients with a mean age of sixty-three years. All procedures were performed with a 22-mm femoral head, and all femoral and acetabular components were fixed with cement. The patients were followed at routine intervals and were specifically queried about dislocation. The cumulative risk of dislocation was calculated with use of the Kaplan-Meier method. Results: Three hundred and twenty hips (4.8%) dislocated. The cumulative risk of a first-time dislocation was 1% at one month and 1.9% at one year and then rose at a constant rate of approximately 1% every five years to 7% at twenty-five years for patients who were alive and had not had a revision by that time. Multivariate analysis revealed that the relative risk of dislocation for female patients (as compared with male patients) was 2.1 and that the relative risk for patients who were seventy years old or more (as compared with those who were less than seventy years old) was 1.3. Three underlying diagnoses—osteonecrosis of the femoral head, acute fracture or nonunion of the proximal part of the femur, and inflammatory arthritis—were associated with a significantly greater risk of dislocation than osteoarthritis was. Conclusions: The cumulative long-term risk of dislocation after total hip arthroplasty is considerably greater than has been reported in short-term studies. The incidence of dislocation is highest in the first year after arthroplasty and then continues at a relatively constant rate for the life of the arthroplasty. Patients at highest risk are female patients and those with a diagnosis of osteonecrosis of the femoral head or an acute fracture or nonunion of the proximal part of the femur. Level of Evidence: Prognostic study, Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.

Theoretically, micromotion might occur even in stable cement-implant interface conditions. It was hypothesized that smoothing of the matte surfaces of femoral components because of abrasion or corrosion phenomena is a possible consequence of micromotion. Two new and 11 femoral components that were retrieved after 2 to 15 years of stable cement-implant interface conditions were inspected, investigated with light microscopy, and evaluated with surface roughness measurement by a profilometer. No surface changes were observed such as abrasion or corrosion phenomena except at the tip and the collar of the femoral components. The surface roughness was Ra = 1.0 and 1.1 micro m in the new femoral components and Ra (mean) = 0.96 micro m (range; 0.8-1.5 micro m) in the retrieved components. There was no correlation between time in situ and surface roughness as confirmed by regression analysis. These data suggest that significant micromotion was not present at the studied interface.

Background: Some patients have a dislocation for the first time many years after a total hip arthroplasty, but little is known about the risk factors and outcomes associated with late dislocation. The purposes of this study were (1) to determine the prevalence of late dislocation after total hip arthroplasty, (2) to characterize demographic and other factors associated with such late dislocations, and (3) to report the outcomes of such late dislocations. Methods: Between 1969 and 1995, 19,680 primary total hip arthroplasties were performed in 15,964 patients at our institution. According to a prospective surveillance protocol, the patients were followed routinely at regular intervals and were specifically queried at each time-point about whether (and, if so, when) the hip had dislocated. First dislocations that occurred five years or more after the operation were defined as late dislocations. Results: Five hundred and thirteen (2.6%) of the 19,680 hips dislocated. Of the 513 hips, 165 (0.8% of the entire cohort; 32% of the dislocated hips) first dislocated five or more years after the primary arthroplasty. The median time until the occurrence of these late dislocations was 11.3 years (range, five to 24.9 years) after the operation. Late dislocation was more frequent than early dislocation in women (p = 0.03), and late dislocation was associated with a younger age at the time of the primary total hip arthroplasty (median, sixty-three years) than was early dislocation (median, sixty-seven years) (p = 0.02). Clinical factors associated with late dislocation included previous subluxations without dislocation in twenty patients, a substantial episode of trauma in eleven patients, and onset of marked cognitive or motor neurologic impairment in eleven patients. Radiographically, the late dislocation occurred in association with polyethylene wear of >2 mm in eighteen hips, with implant loosening with migration or a change in position in eight, and with initial malposition of the acetabular implant (anteversion of 30d or abduction of >55d) in thirty. Late dislocation recurred in ninety (55%) of the 165 hips and was treated with a reoperation in fifty-five hips (33% of the hips with late dislocation; 61% of the hips with recurrent dislocation). Conclusions: Late dislocation is more common than was previously thought. Several separate processes, some distinct from those associated with early dislocation, can lead to late dislocation. Late dislocation can occur in association with a long-standing problem with the prosthesis that manifests late (such as malposition of the implant or recurrent subluxation), it can occur in association with a new problem (such as neurologic decline, an episode of trauma, or polyethylene wear), or it can occur in association with any combination of these factors. The likelihood of the first late dislocation recurring is high.

This autopsy study analyzed the migration of polyethylene wear debris adjacent to uncemented femoral components with circumferential porous coating. Five femoral specimens retrieved at autopsy from 3 patients were investigated. Two stems were 40% porous coated, 2 were 80% porous coated, and 1 was 100% porous coated. The implants' time in situ ranged from 53 to 132 months (average, 94.8 months). All patients were followed clinically and radiographically until death. Radiographically, 3 of the stems were bone ingrown with proximal bone loss, 1 stem was mainly fibrous encapsulated, and 1 stem was completely fibrous encapsulated. Histologic examination of bone adjacent to the middle and distal sections of the femoral implant revealed no polyethylene wear debris or granulation tissue in any of the specimens. In 2 bone-ingrown cases, a small number of polyethylene particles and small areas of granulation tissue were present at the proximal level. This granulation tissue, however, did not cause major osteolysis. The findings in this study imply that circumferential porous coating of cementless femoral components could prevent distal migration of polyethylene wear debris along the bone-implant interface in both bone-ingrown and fibrous-encapsulated femoral implants.

A 62-year-old female patient showed radiographic signs of severe linear wear of the acetabular component six years after cementless total hip arthroplasty. This suggested wear-through of the acetabular liner with secondary wear of the titanium shell. At revision surgery wear-through of both the inlay and the acetabular shell were confirmed. Despite meticulous debridement serum titanium levels remained elevated for more than 12 months. Wear-through of a polyethylene acetabular liner with secondary wear of the titanium shell can lead to increased titanium serum levels. Titanium serum levels can remain highly elevated despite revision surgery.

STUDY DESIGN Retrospective case report. PURPOSE This case demonstrates that paraplegia can develop due to chylous leakage into the spinal canal without obvious retroperitoneal or intrathoracic involvement. BACKGROUND INFORMATION This clinical presentation of chylous leakage has not been reported previously. RESULTS A 61-year-old female with osteoporosis suffered a pathologic fracture of the vertebral bodies T12 and L1 and developed partial paraplegia two weeks later. Imaging showed expansive pooling of intraspinal fluid without intrathoracic or retroperitoneal involvement. A blood-tinged fluid was aspirated from dorsal. Repeated surgery by a posterior approach with drainage of the fluid did not improve the patient's condition, so she was finally transferred to our hospital. Under the suspected diagnosis of lymphatic leakage a scintiscan with 123I-iodinephenylpentadekanacid-marked cream verified the presumption of a lymph fistula at the level of T12/L1, originating from the thoracic duct. By permanent draining of the posterior fistula without suction and strict intravenous alimentation the fluid production decreased continuously and finally ceased completely. Simultaneously, the neurologic state improved gradually without returning to normal completely. CONCLUSIONS This case demonstrates that paraplegia can develop due to chylous leakage into the spinal canal without obvious retroperitoneal or intrathoracic involvement. This differential diagnosis should be kept in mind when treating patients with abundant fluid drainage into or from the spinal canal.

We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yielded no pathological findings. Overnight the neurological deficits decreased without therapy and were finally no longer detectable. We speculate that during the administration of the local anaesthetic a depot formed, localised in the medial femoral intermuscular septa, which was leaked after first mobilisation. To our knowledge no similar case has been published up to now. We conclude that patients who are treated with a nerve block should be informed and physician should be aware that delayed neurological deficits are possible.

Background Periprosthetic osteolysis is a major cause of aseptic loosening in joint arthroplasty. This study investigates the impact of CT (calcitonin) deficiency and CT substitution under in-vivo circumstances on particle-induced osteolysis in Calca -/- mice. Methods We used the murine calvarial osteolysis model based on ultra-high molecular weight polyethylene (UHMWPE) particles in 10 C57BL/6J wild-type (WT) mice and twenty Calca -/- mice. The mice were divided into six groups: WT without UHMWPE particles (Group 1), WT with UHMWPE particles (Group 2), Calca -/- mice without UHMWPE particles (Group 3), Calca -/- mice with UHMWPE particles (Group 4), Calca -/- mice without UHMWPE particles and calcitonin substitution (Group 5), and Calca -/- mice with UHMWPE particle implantation and calcitonin substitution (Group 6). Analytes were extracted from serum and urine. Bone resorption was measured by bone histomorphometry. The number of osteoclasts was determined by counting the tartrate-resistant acid phosphatase (TRACP) + cells. Results Bone resorption was significantly increased in Calca -/- mice compared with their corresponding WT. The eroded surface in Calca -/- mice with particle implantation was reduced by 20.6% after CT substitution. Osteoclast numbers were significantly increased in Calca -/- mice after particle implantation. Serum OPG (osteoprotegerin) increased significantly after CT substitution. Conclusions As anticipated, Calca -/- mice show extensive osteolysis compared with wild-type mice, and CT substitution reduces particle-induced osteolysis.

One of the main problems after total knee arthroplasty is pain in the patellofemoral joint, which in some cases leads to revision surgery. Rotation of the femoral component has a significant influence on the path followed by the patella within the patellofemoral joint. We examined the influence of rotation of the femoral component after total knee arthroplasty on patellar tilt. We retrospectively analysed the radiographs of 48 patients who underwent primary LCS total knee arthroplasty without patella resurfacing and without lateral release. Rotation of the femoral component was determined using Kanekasu's technique and patellar tilt assessment according to Laurin on Merchant's views. This radiographic study confirmed a highly significant correlation between external rotation of the femoral component and a decrease in patellar tilt following TKA. Furthermore, we found a highly significant correlation between pre- and postoperative patellar tilt angle.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to evaluate the DNA damage repair capacity of macrophages in patients with aseptic hip loosening by determination of ERCC1. Moreover, we wanted to elucidate if the potency of the DNA-repair mechanisms correlates with the survival of joint implants. For this purpose we compared the immunohistochemical ERCC1 expression in capsules and interface membranes of patients with loosening of a hip replacement in the first 10 years after implantation with those in patients with late loosening. In analogy with ERCC1 studies on cancer in humans we calculated the semi-quantitative H-score by multiplying the staining intensity with the proportion score of positive stained macrophages. The level of ERCC1 reaction in the specimens taken from patients with early aseptic loosening (mean H-score 0.57) was clearly lower in comparison with those from patients undergoing exchange hip arthroplasty later than 10 years after surgery (mean H-score 2.24). We determined an H-score for ERCC1 expression of 1 as a cutoff point giving a sensitivity and specificity of 100% for identification of early aseptic loosening after less than 10 years. In summary, lower levels of ERCC1 were found in patients with early aseptic loosening compared to patients with aseptic loosening later than 10 years.

Background: Micro-structural changes associated with ultra high molecular weight polyethylene particle (UHMWPE) induced osteolysis, the most frequent cause of aseptic loosening, have been intensively investigated in the mammalian calvarian model by histomorphometry and micro-computed tomography. However, little is known regarding the serological changes that occur during this process. Methods: Serological parameters for bone metabolism [calcium, phosphate, osteocalcin (OCN), deoxypyridinoline (DPD)/creatinine, alkaline phosphatase, osteoprotegerin and receptor activator of nuclear factor-κB] were analyzed in this animal model for particle induced osteolysis. Ten C57BL/6 mice were divided at random into sham operated and UHM-WPE implanted groups. Blood and urine samples were collected prior to and at 14 days after surgery. Results: Implantation of UHMWPE lead to a significant decrease in bone volume (p=0.027). Both groups (sham/UHMWPE) showed a significant increase in calcium (p=0.004/p=0.027) and phosphate (p=0.001/p=0.001), without correlation to particle implantation. Significantly higher concentrations of DPD/creatinine (p=0.034) and OCN (p=0.022) were found after implantation of UHM-WPE. In addition, parameters could not be correlated to particle induced osteolysis. Conclusions: DPD can be regarded as a valuable parameter for detecting UHMWPE induced osteolysis in the calvarian model. Further studies of serum parameters should focus on the clinical relevance in aseptic prosthetic loosening. Clin Chem Lab Med 2010;48:1641–6.

Plain radiography, bone scintigraphy, digital subtraction arthrography and various other techniques can be used to evaluate loosening of hip replacements. These methods are associated with radiation exposure and some of them have an increased morbidity. Furthermore, in some cases the results are not conclusive.The osteoclast biomarkers tartrate-resistant acid phosphatase 5b (TRAP 5b) and C-terminal telopeptides of type I collagen (CTX) in serum taken from 12 patients with aseptic loosening were measured. Serum samples from 24 other patients, 12 with an intact arthroplasty and 12 without any kind of joint replacement, served as control groups.The serum level of CTX was increased in comparison to the control groups, but the differences were not significant. In contrast, the increase in TRAP 5b in patients with aseptic loosening was highly significant (P0.001). A TRAP 5b value of 3.365 U/L was determined as a cut-off value, giving a sensitivity of 83.3% and specificity of 91.7% to differentiate the patients with aseptic loosening from those with an intact arthroplasty. Measurement of serum TRAP 5b may be a clinically relevant assay for monitoring patients after arthroplasty.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. Earlier studies demonstrated apoptotic macrophages, giant cells, fibroblasts and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening. The aim of the current study was to determine in a murine calvarial model of wear particle-induced osteolysis whether inhibition of apoptosis using the pan-caspase inhibitor BOC-D-FMK reduces aseptic loosening. Healthy 12-week-old male C57BL/6J mice were treated with UHMWPE particles and received a daily peritoneal injection of BOK-D-FMK, respectively only buffer at a dose of 3 mg/kg of body weight for 12 days until sacrifice. Bone resorption was measured by histomorphometry, micro CT (computed tomography) and TRAP-5b serum analysis. Apoptosis was measured using caspase-3 cleaved staining. The results demonstrated that UHMWPE particles induced stronger apoptotic reactions in macrophages and osteoblasts and increased bone resorption in non-specifically treated mice, whereas peritoneal application of BOC-D-FMK significantly counteracted these adverse particle-related effects. We think that in particle-induced osteolysis apoptosis is pathologically increased, and that failure to reduce the quantity of apoptotic bodies leads to an up-regulation of proinflammatory cytokines, which may be responsible for the induction of osteolysis. We showed for the first time in vivo that a reduction in apoptosis leads to a significant reduction in particle-induced osteolysis. Clinically, the apoptotic cascade could become an interesting novel therapeutic target to modulate particle-induced osteolysis.

The purpose of this study was to elucidate if the adiponectin level correlates with the survival of joint replacements. Current data indicates that adiponectin regulates lipid and glucose metabolism and acts anti-inflammatory and anti-apoptotic. We compared the value of adiponectin in serum taken from patients with early loosening in the first 10 years after implantation with serum from patients with late loosening and from patients without any kind of arthroplasty. Adiponectin was measured using a human Adiponectin ELISA test kit. Serum levels of adiponectin were significantly (p < 0.001) lower in patients with a short hip arthroplasty survivorship of up to 10 years (4.10 mg/microL) in comparison with those from patients undergoing exchange hip arthroplasty later than 10 years after primary surgery (10.86 mg/microL). We speculate that increased adiponectin serum levels may be associated with increased survival of hip replacements by reducing wear particle-induced inflammatory reactions and promoting clearance of apoptotic cell remnants. In conclusion, patients with low levels of adiponectin may have a significantly higher risk for early aseptic loosening when compared with patients with a high level.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to identify various apoptosis-related pathways in the cellular response to wear debris. Fas receptor, BAK and caspase-3 cleaved were evaluated immunohistochemically in capsules and interface membranes from patients with aseptic hip implant loosening. Moreover, we investigated local cellular proliferation, documented by the presence of Ki-67, to evaluate the proportion of apoptosis in relation to the proliferation in the different cells. We detected a strong expression of caspase-3 cleaved, Fas and BAK in macrophages, giant cells and T-lymphocytes. The fibroblasts showed caspase-3 cleaved and BAK, but no Fas staining. Demonstrated by Ki-67 staining, we found increased proliferation of macrophages and fibroblasts. Statistical analysis showed a significant positive correlation (p0.001) between the above mentioned results and the presence of wear debris. The intensity of apoptosis and proliferation differed, depending on the extent of osteolysis. Overall, four different patterns of immunoreactivity were identified. We think, however, that in particle-induced osteolysis apoptosis is pathologically increased - a phenomenon also seen in other diseases. In these instances, the number and degree of apoptotic reactions are so great that the resulting cell remains cannot be completely removed. This leads to an increased excretion of fibrogenic mediators that could be responsible for increased proliferation of fibroblasts in spite of the increased apoptosis. Moreover, it leads to an increased excretion of cytokines which could be responsible for the activation of osteoclasts.

The treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). The purpose of this study was to evaluate the clinical and radiological outcome of revision THA using jumbo cups for acetabular reconstruction after applying the bone-grafting technique. We studied 17 patients with acetabular defects ranging from Type 2A to Type 3A according to Paprosky's classification. According to the AAOS-score twelve patients were classified as Type II and five patients as Type III. Uncemented press-fit cups with an outer diameter larger than 64 mm were used in all cases. Fifteen patients received morselized bone allografts. In eight patients an additional screw fixation was necessary. The mean follow-up period was 82 months (range 33-149). The mean Harris Hip Score was preoperatively 62 and at the time of the last follow-up examination 83 points (p = 0.007). Two acetabular components failed, one due to aseptic loosening and another one due to septic loosening. There was a trend of displacement of the femoral head centre towards the infero-lateral position after using jumbo cups that approached statistical significance (p = 0.065). Closure of acetabular defects of Types 2A to 3A according to Paprosky's classification and type II to III according to the AAOS-score respectively can be satisfactorily accomplished using jumbo cups after applying the bone-grafting technique.

This study investigates the impact of α-CGRP on bone metabolism after implantation of polyethylene particles. α-CGRP knockout mice showed less osteolysis compared with wildtype mice. The local neurogenic microenvironment might be a crucial factor in particle-induced osteolysis. Introduction: Periprosthetic osteolysis is the major reason for aseptic loosening in joint arthroplasty. This study aimed to investigate the potential impact of α-calcitonin gene–related peptide (α-CGRP) deficiency on bone metabolism under conditions of polyethylene particle–induced osteolysis. Materials and Methods: We used the murine calvarial osteolysis model based on polyethylene particles in 14 C57BL 6 mice and 14 α-CGRP–deficient mice divided into four groups of 7 mice each. Groups 1 (C57BL/J 6) and 3 (α-CGRP knockout) received sham surgery, and groups 2 (C57BL/J 6) and 4 (α-CGRP knockout) were treated with polyethylene particles. Qualitative and quantitative 3D analyses were performed using μCT. In addition, bone resorption was measured within the midline suture by histological examination. The number of osteoclasts was determined by counting the TRACP+ cells. Calvarial bone was tested for RANKL expression by RT-PCR and immunocytochemistry. Results: Bone resorption was significantly reduced in α-CGRP–deficient mice compared with their corresponding wildtype C57BL 6 mice as confirmed by histomorphometric data (p < 0.001) and μCT (p < 0.01). Osteoclast numbers were significantly reduced in group 3 and the particle subgroup compared with group 1 (p < 0.001). We observed a >3-fold increase of basal RANKL mRNA levels within group 1 compared with group 3. Additional low RANKL immunochemistry staining was noted in groups 3 and 4. Conclusions: In conclusion, α-CGRP knockout mice did not show the expected extended osteolysis compared with wildtype mice expressing α-CGRP. One of the most reasonable explanations for the observed decrease in osteolysis could be linked to the osteoprotegerin (OPG)/RANK/RANKL system in α-CGRP–deficient animals. As a consequence, the fine tuning of osteoclasts mediating resorption in α-CGRP–null mice may be deregulated.

A 62-year-old female patient showed radiographic signs of severe linear wear of the acetabular component six years after cementless total hip arthroplasty. This suggested wear-through of the acetabular liner with secondary wear of the titanium shell. At revision surgery wear-through of both the inlay and the acetabular shell were confirmed. Despite meticulous debridement serum titanium levels remained elevated for more than 12 months. Wear-through of a polyethylene acetabular liner with secondary wear of the titanium shell can lead to increased titanium serum levels. Titanium serum levels can remain highly elevated despite revision surgery.

Does the pressfit anchorage of cementless acetabular cups depend on the roughness of the pole? To answer this question the primary pressfit of two cementless acetabular cups which differ only with regard to the roughness of their poles were compared by means of finite elements analysis.It was assumed that the material properties of bone are homogeneous, isotropic and linearly elastic. Material-specific values of cancellous bone with three different bone densities were used. Assumption of isotropy represents an approximation.Comparison of the two prosthesis designs revealed that both designs/shapes cause similar patterns of bone deformation and tension.It can therefore be concluded that with regard to pressfit anchorage the prosthesis with milled polar surface is according to FEA mechanically equivalent to the prosthesis with non-milled polar surface.

Anteroposterior pelvic radiographs are routinely used to monitor cup orientation in total hip arthroplasty (THA). Analysis of planar radiographs leads to a certain degree of measurement error for the cup anteversion (AV). With the current study, we wanted to clarify whether planar radiography can be used for accurate evaluation of the THA position. The postoperative orientation of pelvic implants in 42 patients was analyzed according to five documented mathematical algorithms using planar radiographs. Postoperative computed tomography (CT) pelvis scans were available for all patients. A CT-based navigation system was used to determine AV. The comparison showed that all five formulas presented substantial variations for the AV angle. Of these, Widmer’s algorithm presented the smallest difference compared to the CT. Misinterpretation of postoperative planar radiographs is a common problem in THA. Planar radiographs are too imprecise for exact evaluation of the correct cup AV after THA. CT-based analysis may be necessary if exact values are required.

Alterations of the key regulators of osteoclastogenesis, receptor activator of NF-kappaB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) have been implicated in wear particle-induced osteolysis, the most common cause for implant failure in total joint replacements. This study investigated the effect of exogenous OPG on ultra-high-molecular-weight polyethylene (UHMWPE) particle-induced osteolysis. The murine calvarial osteolysis model was utilized in 28 C57BL/6J mice randomized to four groups. Group I underwent sham surgery only, group II received UHMWPE particles, and group III and IV particles and subcutaneous OPG starting from day 0 (group III) or day 5 (group IV) until sacrifice. After 2 weeks, calvaria were prepared for histology and histomorphometry. Bone resorption was measured within the midline suture using Giemsa staining and osteoclast numbers were determined using TRAP staining. UHMWPE particle implantation resulted in grossly pronounced osteoclastogenesis and bone resorption. Both immediate and delayed treatment with OPG counteracted these particle-induced effects significantly, suppressing osteoclast formation and bone resorption (p < 0.001 and p < 0.001, respectively). In conclusion, exogenous OPG markedly suppressed UHMWPE particle-induced osteolysis in a murine calvarial model. This important finding underscores the crucial significance of the OPG-RANKL-RANK signaling in wear particle-induced osteolysis. Exogenous OPG may prove an effective treatment modality for wear debris-mediated periprosthetic osteolysis after total joint arthroplasty.

The value of plain radiographs, digital subtraction arthrography and radionuclide arthrography was analysed in 23 cases of failed total knee arthroplasty. The preoperative diagnosis was compared with the intraoperative assessment. Sensitivity, specificity and the positive and negative predictive value for assessing a loose component were determined separately for the femoral and tibial components. At revision we found 13 loose femoral and 12 loose tibial implants. In eight cases both components were unstable. Plain radiography had a sensitivity of 77% for loosening of the femoral and 83% for the tibial component; digital subtraction arthrography 77% for the femoral and 8% for the tibial component and radionuclide arthrography 31% and 8%. The specificity for plain radiography was 90% for the femoral and 72% for the tibial implant. For subtraction arthrography it was 50% and 82% and for subtraction arthrography 70% and 82%. Radiography had the highest positive and negative predictive values for both components compared with the other two techniques. As a diagnostic tool to detect implant loosening, plain radiography is the most effective in this study. Subtraction arthrography and radionuclide arthrography are not suitable for use as routine methods for detection of total knee arthroplasty loosening.