Characteristics and outcome of 27 elbow periprosthetic joint infections: results from a 14-year cohort study of 358 elbow prostheses.

Elbow arthroplasty is increasingly performed in patients with rheumatic and post-traumatic arthritis. Data on elbow periprosthetic joint infection (PJI) are limited. We investigated the characteristics and outcome of elbow PJI in a 14-year cohort of total elbow arthroplasties in a single centre. Elbow prosthesis, which were implanted between 1994 and 2007 at Schulthess Clinic in Zurich, were retrospectively screened for infection. PJI was defined as periprosthetic purulence, the presence of sinus tract or microbial growth. A Kaplan-Meier survival method and Cox proportional hazard analysis were performed. Of 358 elbow prostheses, PJI was identified in 27 (7.5%). The median patient age (range) was 61 (39-82) years; 63% were females. Seventeen patients (63%) had a rheumatic disorder and ten (37%) had osteoarthritis. Debridement and implant retention was performed in 78%, followed by exchange or removal of the prosthesis (15%) or no surgery (7%).The relapse-free survival (95% CI) was 79% (63-95%) after 1 year and 65% (45-85%) after 2 years. The outcome after 2 years was significantly better when patients were treated according to the algorithm compared to patients who were not (100% vs. 33%, p <0.05). In 21 patients treated with debridement and retention, the cure rate was also higher when the algorithm was followed (100% vs. 11%, p <0.05). The findings of the present study suggest that the treatment algorithm developed for hip and knee PJI can be applied to elbow PJI. With proper patient selection and antimicrobial therapy, debridement and retention of the elbow prosthesis is associated with good treatment outcome.

[Western Ontario shoulder instability index (WOSI): translation and cross-cultural adaptation for use by German speakers]. / "Western Ontario Shoulder Instability Index" (WOSI) : Ubersetzung und transkulturelle Anpassung für den deutschsprachigen Gebrauch.

BACKGROUND: Outcome assessment after orthopaedic interventions is becoming more and more important. However, there are no disease-specific instruments for patient self-assessment of shoulder instability. The goal of our study was to translate and test the Western Ontario Shoulder Instability Index (WOSI) using a standardised approach. The guidelines of the American Association of Orthopedic Surgeons were used for the translation and cross-cultural adaptation process. MATERIAL AND METHOD: Understanding was tested in 20 healthy subjects, and reliability and validity were quantified in 30 patients with shoulder instability. The quality of the translated version was described using the criteria of homogeneity, reliability, and construct validity. RESULTS: The test-retest reliability of the total score [intraclass correlation coefficient (ICC), 0.87] and of the subscores with the ICC (sports, leisure, and work 0.73; sensitivity 0.81; physical symptoms 0.82; and behaviour 0.90) was high. The internal consistency of the total scale was also high (Cronbach's alpha 0.89). CONCLUSIONS: The WOSI covers a broad range of symptoms and impaired functioning in patients with shoulder instability. The German translation shows good results regarding understanding, homogeneity, reliability, and validity. Therefore, it is a useful instrument for self-assessment in patients with shoulder instability.

Age- and gender-specific normative data of grip and pinch strength in a healthy adult Swiss population.

Assessment of hand strength is used in a wide range of clinical settings especially during treatment of diseases affecting the function of the hand. This investigation aimed to determine age- and gender-specific reference values for grip and pinch strength in a normal Swiss population with special regard to old and very old subjects as well as to different levels of occupational demand. Hand strength data were collected using a Jamar dynamometer and a pinch gauge with standard testing position, protocol and instructions. Analysis of the data from 1023 tested subjects between 18 and 96 years revealed a curvilinear relationship of grip and pinch strength to age, a correlation to height, weight and significant differences between occupational groups. Hand strength values differed significantly from those of other populations, confirming the thesis that applying normative data internationally is questionable. Age- and gender-specific reference values for grip and pinch strength are presented.

The patient-rated wrist evaluation (PRWE): cross-cultural adaptation into German and evaluation of its psychometric properties.

OBJECTIVE: To cross-culturally adapt the Patient-Rated Wrist Evaluation form (PRWE) into German (PRWE-G) and to evaluate its reliability and validity. METHODS: A cross-cultural adaptation of the PRWE was carried out, according to established guidelines. 103 patients, who had undergone resection interposition arthroplasty (RIAP) for carpometacarpal osteoarthritis approximately 6.2 years earlier, completed a questionnaire booklet containing the PRWE-G, the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder, and Hand (DASH); they also underwent clinical assessment with the Hand Function Index (HFI, Keitel) and Custom Score including grip and pinch strength tests. The results were used to assess the criterion and construct validity of the PRWE-G. To measure the re-test reliability, 51 patients completed a second PRWE-G within 2 weeks. RESULTS: The test-retest reliability of the PRWE-G was acceptable for the pain and function sub-scales and for the global score, with intraclass correlation coefficients of 0.78-0.87. The PRWE-G showed a high internal consistency (Cronbach's alphas of 0.92-0.97 for the scales and the total score). The typical error of measurement for the global score was 8.1 points, giving a minimal detectable change (MDC95%) of approximately 22.5 points. The PRWE-G scores correlated well with those of the DASH (r=0.82, p<0.001) but less well with those of the physical component summary of the SF-36 (r=0.53, p<0.001) and not at all with the mental component summary scores of the SF-36 (r=0.04, p>0.05). The PRWE-G scores correlated moderately with certain clinical findings of the HFI, Custom Score, and grip/pinch strength tests (r=0.30-0.59, p<0.001). CONCLUSION: The PRWE-G represents a valid and reliable instrument to evaluate self-rated outcome in German-speaking patients with hand and wrist pathology.

Development of a predictive model for estimating the probability of treatment success one year after total shoulder replacement - cohort study.

OBJECTIVE: To Estimate the probability of treatment success 1 year after a total shoulder arthroplasty by developing a model based on preoperative clinical factors. METHOD: Between June 2003 and December 2006, 140 patients undergoing shoulder operations were assessed for age, gender, current rheumatoid arthritis, Short Form (SF) 36 physical and mental sum scores, previous shoulder operations, the Disabilities of Arm, Shoulder and Hand (DASH) symptom and function scores, the Shoulder Pain and Disability Index (SPADI), and insurance status. One year after the operation a Constant score of 80 or more out of 100 indicated successful treatment. Patient variables were analyzed with a logistic regression model augmented in a stepwise manner and bootstrapped 100 times. Variables selected at least 33 times were incorporated into a final model and the Area under the Receiver Operating Characteristics Curve (aROC) was calculated. RESULTS: There were 47/140 (33.6%) successful treatments. The probability of success was reduced in patients with previous shoulder operations (Odds Ratio [O.R.] 0.17, 95% Confidence Interval (95%CI) 0.04-0.85; P=0.03) and older than 75 years (O.R. 0.21, 95%CI 0.05-0.77; P=0.02). The probability of success increased in patients with a higher SF 36 mental sum score (O.R. 1.03, 95%CI 0.96-1.09, P=0.42) and a higher DASH function score (O.R. 1.05, 95%CI 1.02-1.07, P=0.001). The aROC was 0.79 (0.70-0.88) indicating that the model has a high predictive capacity. CONCLUSION: Once validated this model based on four preoperative clinical factors offers a prediction of whether a patient will respond to treatment 1 year after total shoulder arthroplasty.

Key factors for a successful National Arthroplasty Register.

Since the introduction of the first National Arthroplasty Register in Sweden in 1975, many other countries have tried to adopt the successful Scandinavian system. However, not all have overcome the political and practical difficulties of establishing a working register. We have surveyed the current registries to establish the key factors required for an effective database. We have received detailed information from 15 arthroplasty registers worldwide. The legal conditions under which they operate together with the methods of collection and handling of the data differ widely, but the fulfilment of certain criteria is necessary achieve a high degree of completeness of the data to ensure the provision of statistically relevant information.

Cross-cultural adaptation, reliability and validity of the German Shoulder Pain and Disability Index (SPADI).

OBJECTIVE: To cross-culturally adapt the Shoulder Pain and Disability Index (SPADI) from English into German, and to test the reliability and validity of the German version. METHODS: Cross-cultural adaptation of the SPADI was performed according to international guidelines. One hundred and eighteen patients who had undergone shoulder arthroplasty, on average 4 yr previously, completed a questionnaire booklet containing the German SPADI, the Short Form 36 (SF-36), the Disability of the Arm, Shoulder and Hand (DASH) questionnaire, and the American Shoulder and Elbow Surgeons (ASES) questionnaire for the shoulder to assess SPADI's construct validity. One week later, they completed the SPADI again to assess test-retest reliability. RESULTS: The six-step cross-cultural adaptation procedure revealed no major problems with the content or language. The intraclass correlation coefficients for the individual items of the SPADI were between 0.68 and 0.89, and that for the SPADI total score was 0.94. The SPADI total score showed a correlation of 0.61-0.69 with the SF-36 physical scales, of 0.88 with the DASH and of 0.92 with the ASES. CONCLUSIONS: The German SPADI is a practicable, reliable and valid instrument, and can be recommended for the self-assessment of shoulder pain and function.

S100A4 is expressed at site of invasion in rheumatoid arthritis synovium and modulates production of matrix metalloproteinases.

The metastasis-associated protein S100A4 promotes the progression of cancer by regulating the remodelling of the extracellular matrix. The expression of S100A4 in vivo is shown and the functional role of S100A4 in the pathogenesis of osteoarthritis and rheumatoid arthritisis is explored. The expression of S100A4 in rheumatoid arthritis, osteoarthritis and normal synovial tissues was determined by immunohistochemistry. The expression of matrix metalloproteinase (MMP) mRNA was measured in rheumatoid arthritis and osteoarthritis synovial fibroblasts treated and untreated with S100A4 oligomer by real-time polymerase chain reaction. Levels of released MMPs were confirmed by ELISA in cell culture supernatants. S100A4 protein was expressed in rheumatoid arthritis and osteoarthritis synovial tissues, in contrast with normal synovium. S100A4 up regulated MMP-3 mRNA in rheumatoid arthritis synovial fluid, with a peak after 6 h. This resulted in release of MMP-3 protein. MMP-1, MMP-9 and MMP-13 mRNA were also up regulated in synovial fluid, but with different kinetics. MMP-14 mRNA showed no change. Thus, S100A4 protein is expressed in synovial tissues of patients with rheumatoid arthritis and osteoarthritis in contrast with healthy people. It induces the expression and release of MMP-3 and other MMPs from synovial fluid. The data suggest that S100A4-producing cells could be involved in the pathogenesis of osteoarthritis and rheumatoid arthritis, including pannus formation and joint destruction.

Rupture of the subscapularis tendon (isolated or in combination with supraspinatus tear): when is a repair indicated?

Ruptures of the subscapularis tendon, isolated or combined, are rare, and the treatment modalities are controversial. Of 1345 patients who underwent rotator cuff repair in a 7-year period, 73 had either an isolated rupture of the subscapularis or a subscapularis rupture combined with rupture of the supraspinatus. All reconstructions were performed through a deltopectoral approach. Reinsertion of the subscapularis was combined with reconstruction of the supraspinatus in 32 patients. Of the patients, 63 (86%) were re-examined at a mean follow-up of 35 months. The modified Constant score improved from 62% preoperatively to 91% at follow-up. Isolated or combined reconstructions did not result in significant differences with respect to the Constant score. Of the patients, 62 (98%) were satisfied with the operation. Rerupture was found by ultrasound in 8 subscapularis tendons (13%) and 4 supraspinatus tendons (13%). The rerupture rate showed a significant correlation with the Goutallier stage of fatty degeneration and the interval between injury and operation.

Problematic bone fixation with pyrocarbon implants in proximal interphalangeal joint replacement: short-term results.

Seventeen pyrocarbon PIP prostheses were implanted into 14 patients, followed prospectively and reviewed clinically. The patients were assessed after a mean follow-up of 20.5 months subjectively by a VAS pain scale and radiographically. Significant pain relief was noted in all patients from a mean of 7.6 pre-operatively to 1.3 at final follow-up. Migration of one, or both, components was observed radiographically in eight joints and radiolucent lines were evident in three more cases. The clinical results of the implants which had migrated were less favourable for range of motion and grip strength than the stable joints of this series, although, statistically, the results were not significant. The number of possibly unstable prostheses in this series raises the question as to whether pyrocarbon is suitable for uncemented pressfit fixation in combination with early functional rehabilitation.

Trichostatin A sensitises rheumatoid arthritis synovial fibroblasts for TRAIL-induced apoptosis.

BACKGROUND: Histone acetylation/deacetylation has a critical role in the regulation of transcription by altering the chromatin structure. OBJECTIVE: To analyse the effect of trichostatin A (TSA), a streptomyces metabolite which specifically inhibits mammalian histone deacetylases, on TRAIL-induced apoptosis of rheumatoid arthritis synovial fibroblasts (RASF). METHODS: Apoptotic cells were detected after co-treatment of RASF with TRAIL (200 ng/ml) and TSA (0.5, 1, and 2 micromol/l) by flow cytometry using propidium iodide/annexin-V-FITC staining. Cell proliferation was assessed using the MTS proliferation test. Induction of the cell cycle inhibitor p21Waf/Cip1 by TSA was analysed by western blot. Expression of the TRAIL receptor-2 (DR5) on the cell surface of RASF was analysed by flow cytometry. Levels of soluble TRAIL were measured in synovial fluid of patients with RA and osteoarthritis (OA) by ELISA. RESULTS: Co-treatment of the cells with TSA and TRAIL induced cell death in a synergistic and dose dependent manner, whereas TRAIL and TSA alone had no effect or only a modest effect. RASF express DR5 (TRAIL receptor 2), but treatment of the cells with TSA for 24 hours did not change the expression level of DR5, as it is shown for cancer cells. TSA induced cell cycle arrest in RASF through up regulation of p21Waf1/Cip1. Levels of soluble TRAIL were significantly higher in RA than in OA synovial fluids. CONCLUSION: Because TSA sensitises RASF for TRAIL-induced apoptosis, it is concluded that TSA discloses sensitive sites in the cascade of TRAIL signalling and may represent a new principle for the treatment of RA.

[Comparison of rheumatic and post-traumatic elbow joints after total elbow arthroplasty. Comprehensive and specific evaluation of clinical picture, function, and quality of life]. / Vergleich des rheumatischen und posttraumatischen Ellenbogengelenks nach Totalprothese. Eine umfassende sowie spezifische Beurteilung von Klinik, Funktion und Lebensqualität.

BACKGROUND: Patients with elbow destruction due to rheumatoid arthritis (RA) or trauma (PT) were compared to population-based normative data and to each other after total elbow arthroplasty. PATIENTS AND METHODS: Pain, function, and biopsychosocial health were multidimensionally assessed by the generic Short Form 36 (SF-36), the condition-specific Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), and the Patient Related Elbow Evaluation form (PREE) instrument and analyzed by uni- and multivariate methods. RESULTS: Compared to normative values, the examined 59 RA patients were significantly affected in the function scales of the SF-36 and in all DASH scales. The 20 PT patients were worse than the norm only in the DASH function. Function was lower in RA than in PT in the SF-36 scales and in the DASH (RA: 44.4, PT: 70.3, p<0.001). This difference was less distinct in the PREE. CONCLUSION: Total elbow arthroplasty led to a pain-free outcome and normal quality of life, but failed to restore complete function. Functional deficits were larger in the RA patients and could also be measured by the SF-36, possibly due to polyarticular affection.

[Early results of NeuFlex silastic implant in MCP arthroplasty]. / Frühresultate des arthroplastischen Grundgelenkersatzes mit der NeuFlex-Silikonprothese.

For the reconstruction of destroyed metacarpophalangeal (MP) joints in rheumatoid arthritis, the Swanson silicon spacer is still the golden standard. However, long-term follow-up reveals an increasing number of complications, particularly mechanical failure. In order to deal with these problems a number of new, biomechanically different silicone implants have been designed. Among these, the NeuFlex prosthesis has a preflexed hinge of 30 degrees in relation to the shaft axis, a more palmar lying center of rotation and a rectangular hinge with a collarlike platform against the bony surfaces. In a prospective study, the early results of the first thirteen patients operated with the NeuFlex arthroplasty are reported. All patients suffered from rheumatoid arthritis with destruction of the MP joints. The mean follow-up was 12.3 months. A total of 37 joints were replaced. All patients were female with an average age of 56 years. Postoperative reduction of pain, measured on a visual analog scale with the maximum of 10 (VAS), decreased from 6.6 to 0.7 (p < 0.001). Jamar grip strength improved from 4.2 kg preoperatively to 9.9 kg postoperatively (p < 0.005). Range of motion improved from 37 degrees to 57 degrees (p < 0.0001) as a result of a reduction in active extension deficit which reduced from 35 degrees to 15 degrees postoperatively. Ulnar drift was reduced from 20.2 degrees to 3.4 degrees at follow-up (p < 0.005). Radiological evaluation showed no implant failure, no subsidence, and no signs of inflammatory reaction. Overall the NeuFlex silicone implants show encouraging early results which must be confirmed in the long term.

Analysis of a retrieved delta III total shoulder prosthesis.

A reversed Delta III total shoulder prosthesis was retrieved post-mortem, eight months after implantation. A significant notch was evident at the inferior pole of the scapular neck which extended beyond the inferior fixation screw. This bone loss was associated with a corresponding, erosive defect of the polyethylene cup. Histological examination revealed a chronic foreign-body reaction in the joint capsule. There were, however, no histological signs of loosening of the glenoid base plate and the stability of the prosthetic articulation was only slightly reduced by the eroded rim of the cup.

Discrepancy between mRNA and protein expression of tumour suppressor maspin in synovial tissue may contribute to synovial hyperplasia in rheumatoid arthritis.

OBJECTIVE: To investigate the expression of maspin in RA synovial tissue and compare it with the expression in osteoarthritis (OA) and normal synovial tissue (NS). METHODS: Using specific primers for maspin, a 237 bp fragment was amplified from cDNA obtained from cultured RA, OA, and normal synovial fibroblasts (SF) by RT-PCR. Additionally, mRNA expression levels were determined quantitatively by real time PCR. mRNA expression of maspin was investigated on snap frozen and paraffin embedded synovial tissue sections by in situ hybridisation. Immunohistochemistry was used to identify the cell type expressing maspin. SDS-PAGE and western blotting were performed to evaluate the protein expression in cultured SF. To confirm protein synthesis in situ, immunohistochemistry with specific anti-maspin antibodies was performed in synovial tissue sections of patients with RA. RESULTS: RT-PCR showed expression of maspin in all cDNA samples from cultured SF. Maspin mRNA was found to be decreased in RA SF twofold and 70-fold compared with OA SF and NS SF, respectively. Maspin mRNA was expressed in RA, OA, and normal synovial tissue. Importantly, maspin transcripts were also found at sites of invasion into cartilage and bone. At the protein level, maspin could be detected in RA and, less prominently, OA SF. In RA synovial tissue, maspin protein was detected in only a few synovial lining cells. CONCLUSION: Maspin is expressed intensively in RA SF at the mRNA level, but only slightly at the protein level, possibly owing to down regulation of maspin; this may contribute to the hyperplasia of synovial tissue in RA.

[Endoprosthetic surgery of the elbow]. / Endoprothetik des Ellenbogens.

Artificial joint replacement has found a firm place in orthopaedic surgery since its first introduction in the late 1960s. While the initial fixed bearing implants tended to progress to early loosening, the development of so-called "sloppy joints" has seen a major advance in the survival and success rate of this arthroplasty. The surgical approach and technique have also been modified in such a way as to allow a complete ventral release of a flexion contracture, while at the same time preserving the integrity of the extensor mechanism. In this way, the improvement of the biomechanics of the implant combined with diligent surgical technique have enhanced this procedure dramatically. Between 1978 and 1999, 305 GSB 3-type prosthesis were implanted, with the underlying pathologies being rheumatoid arthritis (77%), posttraumatic arthritis (21%) and degenerative arthritis (2%). The range of motion could be significantly improved from the pre-operative state for extension as well as flexion. This was even more obvious in the rheumatoid than in the posttraumatic situation. The survival rate for this type of implant was 90% at 10 years, with the implants after rheumatoid surgery faring somewhat better than those of the posttraumatics. Alternative treatment options, such as resection arthroplasty, distraction arthroplasty, or arthrodesis, are nowadays employed only in rare cases where a previous infection, personal preference or an inability by the patient to co-operate in a rehabilitation program have to be considered. The overall functional results of these types of treatments seem to be inferior to that of elbow arthroplasty. Therefore, this procedure is recommended not only for advanced degenerative and rheumatoid pathologies, but also in cases of posttraumatic arthrosis.

New perspectives on taste and primate evolution: the dichotomy in gustatory coding for perception of beneficent versus noxious substances as supported by correlations among human thresholds.

In various environments where primates are presently observed, as well as in forests and savannas which have been inhabited by australopithecines and early hominids, there are (or there have been presumably) categories of substances eliciting taste signals associated with stereotyped responses. Such is the case for various soluble sugars of fruits and nectars, attracting consumers, and for several plant compounds in which bitter or strongly astringent properties have a repulsive effect. The occurrence of such classes of tasty substances among natural products appears to be related to the evolutionary trends that shaped primate sensory perception (for detecting either beneficent or potentially noxious substances) in the context of a long history of coevolution between animals and plants. Here, we present original psychophysical data on humans (412 individuals aged 17-59 years) as an analogy with which to test recent evidence from electrophysiology in nonhuman primates (Hellekant et al. [1997] J. Neurophysiol. 77:978-993; Danilova et al. [1998] Ann. N.Y. Acad. Sci. 855:160-164) that taste fibers can be grouped into clusters of "best-responding fibers" with two more specific clusters, one for sugars and one for quinine and tannins. The collinearity found between human taste responses (recognition thresholds) for fructose and sucrose, as well as for quinine and tannins, is presented and discussed as another evidence of the two-direction evolutionary trend determining taste sensitivity. Salt perception appears to be totally independent of these trends. Accordingly, the appreciation of a salty taste seems to be a recent culturally learned response, and not a primary taste perception. The very existence of primary tastes is discussed in the context of evolutionary trends, past and present.

Taste thresholds and suprathreshold responses to tannin-rich plant extracts and quinine in a primate species (Microcebus murinus).

Theories of plant chemical defenses discriminate between quantitative digestibility reducers (e.g., tannins) and qualitative toxins (e.g., alkaloids). Since the differential effect on taste of these compounds is poorly known, we recorded ingestive responses of a primate species, Microcebus murinus, to four tannin-rich plant extracts and to quinine, by using the behavioral method of the "two-bottle test." The efficiency of tannic extracts at precipitating protein was measured with the blue BSA method. Inhibition taste thresholds for tannins added to a moderately sweet solution varied between 0.25 and 2 g/l. The threshold for quinine hydrochloride was 0.32 g/l. The profiles of the response/concentration curves established for these astringent and bitter substances were similar, with maximal inhibition of consumption occurring for near-threshold concentrations. The large amounts of quinine required to deter this small-bodied species from feeding were unexpected, given its unspecialized frugivorous/insectivorous diet. We propose that the taste responses of Microcebus to tannins have been shaped in relation to the widespread occurrence of efficient polyphenols in food plants, while low responsiveness to quinine reflects a low risk of ingesting toxic alkaloids when feeding on ripe fruits and insects.