Computed tomography osteoabsorptiometry is reliable for the determination of the subchondral bone mineralization distribution in the rabbit knee.

Rabbits are among the most frequently used animals in osteoarthritis research. It is meanwhile accepted that the subchondral bone plate (SBP) plays a key role in the development of osteoarthritis. The most suitable technique for analyzing subchondral bone mineralization is computed tomography osteoabsorptiometry (CT-OAM). Because CT-OAM has not yet been applied to smaller animals, the purpose of this study is to test the reliability of CT-OAM in the rabbit knee. Another important task in animal experiments is the intra- and interindividual difference of the measurement parameters. Our hypothesis is that there is no difference regarding both the position of the density maxima and the bone mineral density (BMD) of the SBP comparing right and left tibial plateaus of rabbits. For evaluating the reliability, a rabbit knee was examined by computed tomography 6 times at weekly intervals. The subchondral mineralization distribution was measured by means of CT-OAM. Positions of the density maxima and BMD of the SBP were determined in a standardized procedure. Furthermore, both parameters were evaluated in 6 female White New Zealand rabbits. Positions of density maxima and BMD in the SBP in left tibial plateaus were compared with right tibial plateaus. The relative coefficient of variation as a parameter for reproducibility was 1.6% for determining the position of the density maxima and 1.2% for measuring the BMD. The positions of density maxima and relative BMD between right and left tibial plateaus varied only about 2% intraindividually, whereas interindividual variance was about 10%. In conclusion, determination of the position of density maxima as well as BMD of the SBP by means of CT-OAM is reliable and reproducible in the rabbit knee. We recommend using the contralateral limb as control, because intraindividual accordance of the mineralization patterns and of the BMD of the SBP was higher than interindividual accordance.

An evaluation of the efficiency of the use of an anatomical third generation shoulder prosthesis in 102 patients.

PURPOSE OF THE STUDY: In this study a series of 102 cases was reviewed in which a so called third generation shoulder prosthesis had been used. There was an interest in evaluating the quality and efficiency of the outcome. MATERIAL AND METHODS: The patient population consisted of 32 men and 70 women. The mean age was 65.8 years. The mean postoperative follow-up time was 44.5 months. Indication for arthroplasty was all common degenerative and traumatic conditions of the shoulder. All patients were evaluated and analysed prospectively by a standardised protocol. The postoperative investigation consisted of a clinical examination and a radiographic analysis. We used the Constant and the Wülker Score. RESULTS: All patients had a significant improvement in shoulder function independent of the specific indication. The mean postoperative shoulder function attained 88% as measured by the Constant score. With regard to the different indications, the significant improvement was confirmed in each of the groups. Osteoarthritis reached the highest (91%) and rheumatoid arthritis the lowest value (71%). The results of total shoulder arthroplasties was better than in hemi-shoulder arthroplasties (93% versus 86%). CONCLUSIONS: In summary, it could be demonstrated that most indications for shoulder arthroplasty can be successfully treated by using a third generation implant. Total shoulders reach better results in a mid-term follow-up.

Key pinch in healthy adults: normative values.

Intra-individual and inter-individual variations of key pinch strength were analysed in a standardised manner for healthy Caucasian adults (female n = 403; male n = 366) aged between 20 and 95 years. The mean strength was less in women (right 6.6 kg; left 6.1 kg) than in men (right 10.4 kg; left 9.7 kg). Independently of hand dominance or gender, the right side was about 7% stronger. Constitutional variables such as forearm length, forearm circumference and hand size showed a positive correlation with key pinch strength. Since the correlation between age and key pinch was similar in both genders, showing a continuous decrease of strength from the fifth decade of life on, key pinch seems independent from gender-specific hormonal changes. In conclusion, we recommend to side adjust measured values and to include information regarding constitutional characteristics for intra-individual comparison.

[Carpo-metacarpal flexion of the thumb in healthy adults]. / Die Beugefähigkeit im Daumengrundgelenk des gesunden Erwachsenen.

Metacarpophalangeal flexion of the thumb is known to be highly variable. To obtain normative values, active metacarpophalangeal flexion of the thumb was measured bilaterally in healthy Caucasian adults (female n = 403; male n = 366) in a standardized manner. Independent of gender, inter-individual variation was high, ranging between 16 degrees and 90 degrees and showing a continuous decrease with increasing age. Women showed a bigger range of motion than men but in both range of motion was higher on the left thumb (mean 1.4 degrees in women and mean 1.1 degrees in men). No influence of hand dominance was observed. Thus, the healthy contralateral side should be used as parameter of comparison.

[Pathologic glenohumeral stress distribution in calcific tendinosis of the supraspinatus]. / Glenohumerale Fehlbeanspruchung bei Tendinosis calcarea der Supraspinatussehne.

AIM: Based on hypothesis that calcific tendonitis of the supraspinatus tendon (CTSSP) could be associated with glenohumeral imbalance, glenohumeral stress distribution was analyzed. METHODS: 26 patient shoulders with CTSSP, unsuccessfully treated by non-operative measures, were examined. A group of 26 macroscopically normal shoulder specimens served as controls. Analysis of glenohumeral stress distribution was indirect evaluating glenoid subchondral bone mineralization by computed tomography osteoabsorptiometry. Density distribution of glenoid subchondral bone mineralization and the position of the two most frequent density maxima were analyzed. RESULTS: Patterns of subchondral mineralization and position of the anterior density maximum were significantly different between both groups. CTSSP mostly presented with a monocentric, anteriorly increased mineralization indicative for a regional increase of stress. The inferior shift of the anterior density maximum demonstrates a parallel shift of glenohumeral stress distribution. CONCLUSION: Mineralization patterns indicate that glenohumeral stress distribution is not physiologic in CTSSP. Moreover, it is comparable with glenohumeral stress distribution as observed in atraumatic antero-inferior glenohumeral instability. Relevance of this observation should be proven for etiology of CTSSP.

[A 19-year-old patient with acute promyelocytic leukemia and knee swelling]. / 19-jährige Patientin mit akuter Promyelozytenleukämie und Knieschwellung.

We report on a case of a 19-year-old female patient with acute promyelocytic leukemia suffering from febrile monarthitis of the right knee during neutropenia after consolidation chemotherapy caused by Geotrichum capitatum. Apparently this infection occurred due to a hematological reactivation since the patient had already developed Geotrichum capitatum fungemia during induction therapy. Under antimycotic therapy with voriconazole, flucytosine, and caspofungin as well as after two arthroscopic synovectomies with cleansing of the right knee, the infection could be controlled and the full clinical function of the knee joint could be preserved.

Coracoid tip position on frontal radiographs of the shoulder: a predictor of common shoulder pathologies?

The coracoacromial arch is a static anterior-superior stabilizer of the humeral head. Thus coracoacromial arch inclination, which varies depending on coracoid tip position, may be related to shoulder pathologies. Therefore, we retrospectively analysed coracoid tip positions in the true anterior posterior view of different shoulder pathologies: reference shoulders (n=27), shoulders with rotator cuff tear (supraspinatus tear n=29; subscapularis tear n=21) and shoulders with anterior glenohumeral instability (traumatic n=17; atraumatic n=14). In supraspinatus tear shoulders, the coracoid tip projected onto inferior glenoid half in 86% of cases (type I coracoid), extending more inferiorly compared with reference group (p=0.0002) or subscapularis tear shoulders (p<0.0001). In contrast, 78% of cases with subscapularis tear show the coracoid tip projected onto the superior glenoid half (type II coracoid). Atraumatic glenohumeral instabilities had a more superior coracoid tip position than traumatic instabilities (p=0.04), but no differences were observed on basis of coracoid type or in comparison with normal controls. We conclude that coracoid tip position is highly variable. Since type I coracoids are predominant in shoulders with supraspinatus tears and type II coracoids in shoulders with subscapularis tears, coracoid tip position may thus provide a simple diagnostic complement for a probable site of rotator cuff tears.

[Dynamic palmar instability of the ulnar head]. / Die dynamische, palmare Ellenkopfinstabilität - Ein Fallbericht -

Despite obvious clinical symptoms, dynamic, palmar instability of the ulnar head remains a diagnostic and therapeutic problem. This is demonstrated by a case of chronic, palmar instability of the ulnar head after a tear of the triangular fibrocartilage complex (TFCC). A concomitant, minimal dorsal angulation of the radius after a fracture in childhood and a general capsulo-ligamentous laxity possibly were predisposing factors. Aspects of diagnostic and therapeutic options are discussed. In our case, due to secondary arthrosis, an arthrodesis of the distal radioulnar joint combined with a stabilization of the TFCC was opted for. Although the patient is painfree and mobile, she complains of a loss of power in supination. This salvage procedure probably could have been avoided by an earlier diagnosis.

[Resection-interposition arthroplasty in symptomatic hallux valgus: a revision of indication and technique]. / Die Resektions-Interpositions-Arthroplastik bei Hallux valgus: Indikation und Technik im Prüfstand.

AIM: Popularity of resection-interposition-arthroplasty is decreasing due to more specific procedures in hallux valgus surgery. Therefore we analysed the influence of preoperative parameters and technical details to reevaluate this classic procedure. METHOD: In a retrospective, clinical and radiological long-term study (mean 9.6 years) 62 operated feet were examined and the assessed parameters were analysed, with focussing on the negative results. For comparison negative and positive outcome was defined by a hallux-metatarsal-interphalangeal scale (HMIS) and a subjective rating score (SRS). RESULTS: Negative outcome, 34 % according to HMIS and 24 % according to SRS, was characterised in both scoring systems by pain (visual analogue scale), functional deficit (walking distance) and negative cosmetic result (hallux-valgus-angle) (p < 0.01 each). As negative predictive factors we observed an early degenerative arthritis (p < 0.05, HMIS) and a positive metatarsal index (p < 0.05, SRS). Unsatisfactory results were related to an increased resection level of the first phalanx when compared with good results (p < 0.01 in HMIS, p < 0.05 in SRS). CONCLUSION: Resection-interposition arthroplasty in symptomatic hallux valgus seems an inadequate procedure in cases with early arthritis or a positive metatarsal index. However, in accordance with these criteria good results are probable, if resection of the first phalanx does not exceed one third of length.

[The roentgenmorphologic aspects of symptomatic calcifications in patients with calcifying tendinitis of the shoulder: determination of intra- and interobserver variabilities of Gärtner's classification]. / Die röntgenmorphologische Gestalt symptomatischer Verkalkungen bei Tendinosis calcarea der Schulter. Bestimmung der Intra- und Interobservervariabilitäten der Klassifikation nach Gärtner.

AIM OF THE STUDY: The roentgenologic morphology of symptomatic calcified deposits of the rotator cuff can be classified according Gärtner. This classification influences therapeutic procedures and prognosis of clinical outcome in these patients. In the present study intraoberserver-reproducibility and interobserver-reliability of Gärtner's classification were tested. METHODS: Plane radiographs of 100 patients with calcifications of the supraspinatus tendon were classified according the criteria of Gärtner by 6 independent observers twice within 4 months. Intraoberserver-reproducibility and interobserver-reliability were calculated by means of Cohen's kappa-index. RESULTS: kappa-values of intraoberserver-reproducibility had a mean of 0.4208 (SD 0.1299), kappa-values of interobserver-reliability were 0.490 for the first and 0.474 for the second classification. CONCLUSIONS: Determination of intraoberserver-reproducibility gave insufficient to satisfactory results, interobserver-reliability was sufficient. The clinical use of Gärtner's classification to plan therapeutic procedures or to determine clinical prognosis in patients with calcifying tendinitis can be recommended only with limitations.

[The sublabral foramen. Congenital or an acquired variance?]. / Das Foramen sublabrale. Eine angeborene oder eine erworbene Variante?

The sublabral foramen is considered to be a clinically asymptomatic, isolated variant of the anterior-superior capsulo-labral-complex. It may be observed during shoulder arthroscopy and may implicate problems in differential diagnosis of traumatic lesions. In an anatomic study on 89 macroscopically healthy shoulder specimens the age distribution and the incidence in relation to the varying shape of the glenoid as feasible factors of influence for a sublabral foramen (SF) were analyzed in order to elucidate the unknown pathogenesis of SF. In addition histologic sections of three SF samples were obtained. Mean age of the specimens with a sublabral foramen [n=20; 69 (37-84) years] was significantly higher (p=0.04) compared to samples without a sublabral foramen [n=69; 59 (18-94) years]. An increased incidence of a sublabral foramen in relation to a distinct shape of the glenoid could not be established although a prevalence of a glenoid with anterior notch was observed. The results indicate an age-related development of the sublabral foramen,thus in younger patients with an anterior-superior capsulolabral displacement local signs of trauma and involvement of the biceps anchor should be controlled before definitive diagnosis.

[Open surgical procedures in calcifying tendinitis of the shoulder - concomitant pathologies affect clinical outcome]. / Offene Operationsverfahren bei Tendinosis calcarea der Schulter - Begleitpathologien beeinflussen das Operationsergebnis.

AIM OF THE STUDY: Open surgical removal of calcifications in chronic courses of calcifying tendinitis of the shoulder can be combined with acromioplasty. Independent of the surgical procedure not all patients achieve satisfactory surgical results. The aim of the study was to investigate whether preoperatively known epidemiologic, social, clinical and radiologic factors or intraoperative findings might influence the therapeutic outcome. METHODS: Following diagnostic arthroscopy, open removal of the calcifications was done as an isolated procedure (group A, n = 12) or combined with open acromioplasty (group/B, n = 24). Follow-up was 33 months for both groups. RESULTS: Clinical outcomes were comparable in both groups (Group A, 74.9 points; Group B 73.4 points, Constant-Murley score) and independent of gender, age, profession, duration of anamnesis, hospital-stay period, follow-up period, dominance of arm, preoperative Constant-Murley score, calcification morphology and size and acromial type. 20 patients in total achieved a clinical outcome of

[Mineral analysis of roentgenologically defined calcifications in patients with chronic calcifying tendinitis of the rotator cuff]. / Mineralogische Analyse röntgenologisch definierter Verkalkungen bei Patienten mit chronischer Tendinosis calcarea der Rotatorenmanschette.

AIM: Extracorporeal shockwave application (ESWA) is in clinical use to promote disintegration of symptomatic calcifications of the rotator cuff of the shoulder. However, disintegration of roentgenologically comparable calcifications of the rotator cuff is not always successfull. It is known from urologic stone lithotripsy that the susceptibility for disintegration of stone-like concrements depends on their mineral content. Therefore, in the present investigation the relative contents of calcium and phosphorus in rotator cuff calcifications were determined. METHOD: 39 surgically removed rotator cuff calcifications were analyzed by means of atomic emission spectrometry. RESULTS: The relative content of calcium of the rotator cuff calcifications was found to be 22.3 % +/- 5.7 % (mean +/- SD; 6.8 % - 32.4 %), that of phosphorus as 10.5 % +/- 2.4 % (2.7 % - 14.4 %). The data neither depend on the gender of the patients nor on their age at the time point of surgical removal of the rotator cuff calcifications. CONCLUSION: Roentgenologically comparable calcifications of the rotator cuff demonstrated distinct individual differences concerning the relative contents of calcium and phosphorus. The present results may serve as the first indication that the susceptibility of rotator cuff calcifications for disintegration may depend on their relative contents of calcium and phosphorus.

The relation between primary osteoarthritis of the trapeziometacarpal joint and supernumerary slips of the abductor pollicis longus tendon.

We have studied whether accessory abductor pollicis longus slips inserting into the thenar eminence or trapezium influence the incidence and severity of trapeziometacarpal joint osteoarthritis. The right first extensor compartment of 73 cadavers was dissected and trapeziometacarpal degeneration was graded macroscopically. The main abductor pollicis longus tendon which inserted at the metacarpal base was accompanied by supernumerary APL slips in 96% of cases. Thenar or trapezial slips occurred frequently but coexisted in only one case. The incidence of trapeziometacarpal arthritis was not influenced by the number of accessory slips or whether they inserted onto the thenar eminence or the trapezium.

Junctional adhesion molecule interacts with the PDZ domain-containing proteins AF-6 and ZO-1.

We have identified the PDZ domain protein AF-6 as an intracellular binding partner of the junctional adhesion molecule (JAM), an integral membrane protein located at cell contacts. Binding of AF-6 to JAM required the presence of the intact C terminus of JAM, which represents a classical type II PDZ domain-binding motif. Although JAM did not interact with the single PDZ domains of ZO-1 or of CASK, we found that a ZO-1 fragment containing PDZ domains 2 and 3 bound to JAM in vitro in a PDZ domain-dependent manner. AF-6 as well as ZO-1 could be coprecipitated with JAM from endothelial cell extracts, demonstrating the association of the endogenously expressed molecules in vivo. Targeting of JAM to sites of cell contacts could be affected by the loss of the PDZ domain-binding C terminus. Full-length mouse JAM co-distributed with endogenous AF-6 in human Caco-2 cells at sites of cell contact independent of whether adjacent cells expressed mouse JAM as an extracellular binding partner. In contrast, truncated JAM lacking the PDZ domain-binding C terminus did not co-distribute with endogenous AF-6, but was restricted to cell contacts between cells expressing mouse JAM. Our results suggest that JAM can be recruited to intercellular junctions by its interaction with the PDZ domain-containing proteins AF-6 and possibly ZO-1.