Resection interposition arthroplasty of the shoulder affected by inflammatory arthritis

To determine the therapeutic value of resection-interposition arthroplasty (RIAP) of shoulders in rheumatoid or other inflammatory arthritis, 53 patients were reviewed clinically and radiographically after a mean follow-up period of 8.2 +/- 4.3 years (3.5 to 17.5 years). The Constant Score averaged 42.33 +/- 16.2 (12 to 76). Patients with a follow-up period of more than 10 years performed significantly worse than those with shorter follow-up periods. In most cases, radiographs showed a progressive medial displacement and loss of size of the humeral head as well as a decrease of the joint space with time. Abduction proved to be highly dependent on the degree of medial displacement of the humeral head, whereas the Constant Scores correlated with the width of the joint space. Despite initially acceptable postoperative results, outcome at longer follow-up periods worsened as the result of wear of the glenoidal cartilage and osseous resorption of the humeral head, resulting in a progressive medialization of the center of rotation.

The effect of tibial lengthening using the Ilizarov method on the cartilage and the menisci of the knee joint

In order to investigate possible acute damage to the knee joint cartilage and the menisci during tibial lengthening, sixteen young beagle dogs underwent 30% lengthening of the right tibia of 2.5 cm by callus distraction at a distraction rate of twice 0.5 mm per day. A further four dogs comprised the control group with fixator and osteotomy but without lengthening. After a distraction period of 25 days half the dogs were killed (group A) while the other half (eight dogs with limb lengthening and two dogs without) were killed after a further period of 25 days (group B). At the end of the study, the menisci were removed together with three cartilage-bone cylinders from both femoral condyles from the weight-bearing zones as well as from the corresponding tibial condyles. Serial sections from the menisci were stained with haematoxylin and eosin (H&E) and Elastica van Gieson. Sections of the cartilage-bone cylinders were stained with H&E and safranin-O. Cartilage thickness was measured and the glycosaminoglycan content of the joint cartilage was determined using microspectrophotometry. None of the histological preparations obtained from the untreated and distracted sides showed any signs of damage to the cartilage or to the menisci. There were no significant differences between cartilage thickness and proteoglycan content of the untreated side and the lengthened side. Thus, tibial lengthening using the llizarov method does not appear to cause acute damage to the cartilage of the knee joint or to the menisci.

[Endoprosthetic surface replacement of the head of the humerus]

The concept of an endoprosthetic surface replacement of the humeral head differs from that of stemmed endoprostheses. It is the replacement of the destroyed joint surface with reconstruction of the normal anatomy and minimal bone resection. The aim of this prospective study was to evaluate the short-term results of a newly developed cup arthroplasty (Durom-Cup) for the humeral head. In a prospective study, 39 patients with 46 Durom-Cups were evaluated preoperatively and every 3 months postoperatively. The average follow-up was 15 +/- 9 months. The group included 28 shoulders with rheumatoid arthritis, 15 joints with osteoarthritis, and 3 humeral head necroses. The Constant-score and SAS-function score were used. The Constant-score increased from 20.25 +/- 9.06 points preoperatively to 46.62 +/- 14.05 at 3 months, to 48.11 +/- 14.49 at 6 months, and to 55.25 +/- 11.6 at 9 months postoperatively. The Constant-score stayed at this level during further follow-up and was 55.81 +/- 16.31 at 12 months postoperatively. The best results were seen in the group of humeral head necroses with a Constant-score of 71.0 +/- 12.2 compared to 54.66 +/- 13.89 in the group of osteoarthritis and 56.78 +/- 13.33 in patients with rheumatoid arthritis at 12 months postoperatively. The results with the Durom-Cup are encouraging so that cup arthroplasty seems to be a good alternative to stemmed prostheses. The main advantages of the humeral head resurfacing are the bone-preserving fixation and the relatively simple surgical technique.

Recurring synovitis as a possible reason for aseptic loosening of knee endoprostheses in patients with rheumatoid arthritis

We evaluated histologically samples of synovial tissue from the knees of 50 patients with rheumatoid arthritis (RA). The samples were taken during revision for aseptic loosening. The findings were compared with those in 64 knees with osteoarthritis (OA) and aseptic loosening and in 18 knees with RA without loosening. The last group had been revised because of failure of the inlay or the coupling system of a constrained prosthesis. All the patients had had a total ventral synovectomy before implantation of the primary prosthesis. In all three groups a foreign-body reaction and lymphocellular infiltration were seen in more than 80% of the tissue samples. Deposits of fibrin were observed in about one-third to one-half of the knees in all groups. Typical signs of the reactivation of RA such as rheumatoid necrosis and/or proliferation of synovial stromal cells were found in 26% of knees with RA and loosening, but not in those with OA and loosening and in those with RA without loosening. Our findings show that reactivation of rheumatoid synovitis occurs after total knee replacement and may be a cofactor in aseptic loosening in patients with RA.

Changes in canine skeletal muscles during experimental tibial lengthening

In 24 beagles, lengthening of the right tibia was performed by callus distraction after osteotomy and application of a ring fixator. Distraction was started at the fifth postoperative day, with a distraction rate of 0.5 mm twice per day, and ended after 25 days. A control group of six additional dogs underwent tibial osteotomy and external fixation without distraction. Twelve animals with and three animals without leg lengthening were euthanized immediately after the distraction period of 25 days (Group A); the remaining 15 dogs were euthanized after an additional consolidation phase of another 25 days (Group B). From the distracted right leg and from the left control leg the tibialis anterior muscle, extensor digitorum longus muscle, peroneus longus muscle, and gastrocnemius muscle were removed and studied by means of routine histologic, histochemical, and immunohistochemical analyses, and electron microscopic examination. The muscles of the control group showed no differences between the right and left sides. However, in the other 24 dogs of Groups A and B, the authors saw marked alterations affecting only the lengthened muscles but not the muscles of the control limbs. These changes were highly significant and included muscle fiber degeneration and regeneration, target fibers, central cores, minicores, marked endomysial and perimysial fibrosis, and atrophy of Type 1 and Type 2 fibers. In the consolidation period (Group B) fiber type grouping indicated that reinnervation had occurred. In addition, an increase in satellite cells and myoblasts and proliferation of nuclei were observed. The findings of the current study indicate that leg lengthening results not only in muscle fiber degeneration followed by regeneration and reinnervation but also in formation of new muscle tissue.

Human (Homo sapiens) facial attractiveness in relation to skin texture and color

The notion that surface texture may provide important information about the geometry of visible surfaces has attracted considerable attention for a long time. The present study shows that skin texture plays a significant role in the judgment of female facial beauty. Following research in clinical dermatology, the authors developed a computer program that implemented an algorithm based on co-occurrence matrices for the analysis of facial skin texture. Homogeneity and contrast features as well as color parameters were extracted out of stimulus faces. Attractiveness ratings of the images made by male participants relate positively to parameters of skin homogeneity. The authors propose that skin texture is a cue to fertility and health. In contrast to some previous studies, the authors found that dark skin, not light skin, was rated as most attractive.

Time course of osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide during callus distraction

This study involved 15 patients who were undergoing extremity lengthening by callus distraction. Blood samples and radiographs of the callus distraction segment were obtained before surgery, every 2 weeks during the distraction phase, and every 4 weeks between the end of distraction and removal of the fixator. A digital radiograph analysis system was used to determine the radiographic density of the callus distraction segments. In addition, the serum parameters osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide (PICP) were evaluated. The radiographic density was constant during the distraction phase, but increased logarithmically during the consolidation period. Similar kinetics were observed for osteocalcin, with an average coefficient of correlation between these two parameters of 0.66+/-0.15. PICP levels rose rapidly after surgery and increased further during the consolidation period. Serum levels of bone-specific alkaline phosphatase were not uniform between patients, and there was no correlation to the kinetics of radiographic density or the other serum parameters. The similarity between radiographic density and osteocalcin kinetics, as well as the rapid postoperative increase in PICP, imply that further information may be obtained about osteoneogenesis from the study of these two serum parameters.

Short- and medium-term results of the thrust plate prosthesis in patients with polyarthritis

The thrust plate prosthesis is an implant with metaphyseal fixation to the proximal femur, which leaves the diaphyseal bone untouched. Therefore, this implant is preferred in younger patients. It is dependent on good bone quality in the proximal femur. Because the bone quality is reduced in patients with polyarthritis, this kind of endoprosthesis may have a higher failure rate than conventional stemmed endoprostheses in these patients. Therefore, in patients with polyarthritis, even short- and medium-term results of the thrust plate prosthesis should be analyzed. In all, 47 thrust plate prostheses were implanted in 42 patients with polyarthritis (29 with rheumatoid arthritis, 6 with juvenile chronic arthritis, and 7 with spondylarthritis) and followed prospectively. The average age at operation was 40.8+/-10.7 years. Each patient was clinically and radiologically examined preoperatively, 3 and 6 months after the operation, and at the end of each postoperative year. The mean follow-up was 26.1+/-10.7 months. The clinical findings were evaluated using the Harris hip score. Radiologically, 8 different zones of the thrust plate prosthesis were analyzed for radiolucencies. During the 1st year, the Harris hip score rose continuously from the preoperative average of 42.4+/-6.5 points to 78.8+/-10.3 points 3 months postoperatively, 82.3+/-9.8 points 6 months postoperatively, and 86.8+/-10.1 points 1 year after the operation. The subsequent examinations showed Harris hip score remained at the same level. Five patients (5 joints, 10.6%) had to undergo a revision of the thrust plate prosthesis due to aseptic loosening in 3 and septic loosening in 2. Six prostheses (12.6%) showed radiolucencies, mostly below the thrust plate in zones 1 and 2. Two of them were certainly radiologically loose, which raised the failure rate to 7 of 47 (14.8%). The thrust plate prosthesis improves function and alleviates pain in patients with polyarthritis to a satisfactory degree. Concerning the failure rate, this type seems to yield slightly worse results than cementless stemmed endoprostheses in the same patient group. Due to the preservation of the diaphyseal bone of the femur and the possibility of an unproblematic change to a stemmed endoprosthesis, the thrust plate prosthesis can be recommended for younger patients with polyarthritis.

How urine analysis reflects oxidative stress--nitrotyrosine as a potential marker

Enhanced oxidant stress involved in the pathogenesis of cardiovascular (heart failure, atherosclerosis, ischemia-reperfusion injury), neurodegenerative (M. Alzheimer), metabolic (hypercholesterolemia, diabetes) and inflammatory disorders is mimicked by non-intermittent therapy with nitrovasodilators. We used this latter therapy model to study urinary 3-nitrotyrosine (n-tyr) excretion as a potential biomarker that may reflect the enhanced generation of reactive oxygen species. Namely, free or protein-bound n-tyr is formed in the organism by nitration of tyrosine (residues) via peroxynitrite (reaction product of NO&z.ccirf; and O(2)(-)&z. ccirf;). Free n-tyr content was analyzed by gas chromatography in urine obtained from healthy human subjects under a nitrite-limited diet during a two-day non-intermittent transdermal administration of glyceroltrinitrate (GTN; 0.4 mg/h) with or without vitamin C (Vit-C; 55 microg/kg/min) as antioxidant. Concomitant with the development of complete vascular tolerance (loss of dilator action), a progressive increase in urinary n-tyr excretion (up to 186+/-9 microg/day) was demonstrated in volunteers given GTN only. In contrast, when Vit-C was added, the GTN-induced increases in urinary n-tyr content were significantly suppressed (up to 130.20+/-6.91 microg/day), whereas Vit-C alone even decreased urinary n-tyr content (down to 34.00+/-5.66 microg/day), which was below control values (56.0+/-3.4 microg/day). Thus, urinary n-tyr may serve as a biomarker to detect changes in oxidant stress and thereby to evaluate the efficacy of therapeutic interventions aimed at reducing oxidant stress under various pathophysiological conditions.

Morphometric analysis of canine skeletal muscles following experimental callus distraction according to the Ilizarov method

Muscle fiber diameter and fiber-type distribution were analyzed during callus distraction. The right tibia in 24 beagles was lengthened 2.5 cm by callus distraction after osteotomy and application of a ring fixator. Distraction was started at the fifth postoperative day, at a rate of two times for 0.5 mm per day. Twelve dogs that underwent limb-lengthening and three dogs in the control group that did not undergo limb-lengthening were killed at the end of the 25-day distraction phase (group A). The remaining dogs (12 that underwent limb-lengthening and three that did not) were killed after an additional consolidation period of 25 days (group B). The tibialis anterior, extensor digitorum longus, peroneus longus, and gastrocnemius muscles were removed from the right limb (which had undergone distraction) and the left control side of each animal. Crosscut cryostat sections were stained by adenosine triphosphatase at pH 4.3 and 9.4 to determine the size and distribution of types I and II fibers. Morphometric analysis of the muscle fibers was performed by a computer-assisted two-point technique. On the lengthened side, the muscles revealed marked atrophy affecting predominantly type-II fiber in the dogs in group A and affecting both fiber types in dogs in group B. Fiber density increased in both groups. In addition, fiber-type grouping indicative of reinnervation was obvious in group B. Fiber-type distribution in the dogs in group B showed a shift toward type I in the tibialis anterior (p = 0.043) and extensor digitorum longus (p = 0.034) muscles and a shift toward type II in the gastrocnemius (p = 0.038). The data show that tension-stress during tibial lengthening leads to atrophy of type-II fiber, reflecting disuse of muscle fiber in the distraction period as well as neurogenic atrophy followed by the reinnervation processes. Furthermore, the data are consistent with the occurrence of histoneogenesis during limb-lengthening resulting in an increase in fiber density.

Changes in canine peripheral nerves during experimental callus distraction

In 24 beagles, lengthening of the right tibia was performed by callus distraction after osteotomy and application of a ring fixator. Distraction was started the fifth day after surgery with a distraction rate of 0.5 mm twice per day and ended after 25 days. A control group of six additional dogs underwent tibial osteotomy and external fixation without distraction. Twelve animals with leg lengthening and three animals without leg lengthening were sacrificed immediately after the distraction period of 25 days (Group A), the remaining 15 dogs were sacrificed after an additional consolidation phase of another 25 days (Group B). From the distracted right leg and from the left control side of each animal, the tibial and peroneal nerves were removed and studied by means of morphometric analysis of semithin sections and electron microscopic study. The authors reported only minor alterations of the myelinated nerve fibers consisting in relatively thin myelinated remyelinating nerve fibers, single axon degeneration, or macrophages. There was no axonal sprouting. In contrast, electron microscopic study disclosed signs of late Wallerian degeneration and axonal regeneration of the nonmyelinated axons. Morphometric analysis of the peroneal nerves revealed a significant increase of fiber density and a reduced mean axon and fiber diameter in the consolidation period (Group B). Similar changes were found in the tibial nerves in Group A and disappeared in the consolidation phase (Group B). These features indicate that callus distraction leads to moderate degenerative changes, followed by repair mechanisms, almost complete recovery, and some nerve fiber growth.

[Partial and total joint replacement in femur head necrosis]

In literature, the results of hip arthroplasty in patients with avascular osteonecrosis of the femoral head vary. The main reason may be the nonhomogeneous patient groups concerning etiology of the femoral head necrosis (FHN). Analyzing the results of hip endoprosthesis in relation to the etiology of FHN leads to the assumption that steroid-induced FHN and FHN with underlying systemic bone diseases (renal osteodystrophy, sickle-cell hemoglobinopathy) have the highest loosening rates. Diseases with immunosuppressive medication and sickle-cell hemoglobinopathy have the highest risk of joint infection. Therefore etiology plays an important role in the long-term results of hip endoprostheses in FHN. Modern cement techniques of the second generation and new non-cemented total hip endoprostheses seem to have better results than older prostheses and cement techniques. We followed-up 52 non-cemented thrust plate prostheses in 45 patients with FHN, prospectively, for at least 2 years (3.7 +/- 1.6 years). The revision rate was 9.6% (two aseptic loosenings in one patient with renal osteodystrophy and one patient with alcohol abuse, as well as three late infections in one patient with alcohol abuse and two patients with renal osteodystrophy). Additionally, five prostheses showed radiologic lines of a minimum of 2 mm. Future studies with longer follow-up are needed to find out whether these prosthetic designs with proximal fixation of the femoral component preserving the diaphysial bone have advantages in young FHN patients.

Electromyographically evident changes in skeletal muscles during tibial lengthening in dogs using the Ilizarov method

Twenty-four beagle dogs underwent a lower leg lengthening on the right side of 2.5 cm at a distraction rate of 2 times 0.5 mm per day using a circular fixator system. After a latency phase of 5 days and a distraction phase of 25 days, 12 dogs (30-day dogs) underwent electromyography (EMG) of the gastrocnemius muscle on the lengthened and on the control side. The remaining half of the dogs underwent EMG after a consolidation phase of 25 days following the end of distraction (55-day dogs). During every EMG, at least 20 different muscle potentials were analyzed, and the duration, amplitude, and number of phases were determined of each individual potential. The 30-day dogs had significantly longer potential phases on the lengthened side and insignificantly smaller amplitudes compared with the control side. Furthermore, we observed a slightly larger number of polyphasic potentials on the distraction side. In the 55-day dogs, no significant differences were observed in the various parameters between the lengthened and the control side. Comparing 30- and 55-day dogs, the duration of the potentials on the distraction side was not significantly shorter in the 55-day dogs, and the amplitude significantly higher. These findings could indicate combined neurogenous and myopathic alterations of the muscles during the early distraction phase which will be compensated during the later distraction period and the consolidation phase by reparative and reinnervation processes, leaving no lasting functional damage.

A new approach for extracellular spin trapping of nitroglycerin-induced superoxide radicals both in vitro and in vivo

Anti-ischemic therapy with nitrates is complicated by the induction of tolerance that potentially results from an unwanted coproduction of superoxide radicals. Therefore, we analyzed the localization of in vitro and in vivo, glyceryl trinitrate (GTN)-induced formation of superoxide radicals and the effect of the antioxidant vitamin C and of superoxide dismutase (SOD). Sterically hindered hydroxylamines 1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine (CP-H) and 1-hydroxy-4-phosphonooxy-2,2,6,6-tetramethylpiperidin (PP-H) can be used for in vitro and in vivo quantification of superoxide radical formation. The penetration/incorporation of CP-H or PP-H and of their corresponding nitroxyl radicals was examined by fractionation of the blood and blood cells during a 1-h incubation. For monitoring in vivo, GTN-induced (130 microg/kg) O2*- formation CP-H or PP-H were continuously infused (actual concentration, 800 microM) for 90 to 120 min into rabbits. Formation of superoxide was determined by SOD- or vitamin C-inhibited contents of nitroxide radicals in the blood from A. carotis. The incubation of whole blood with CP-H, PP-H, or corresponding nitroxyl radicals clearly shows that during a 1-h incubation, as much as 8.3% of CP-H but only 0.9% of PP-H is incorporated in cytoplasm. Acute GTN treatment of whole blood and in vivo bolus infusion significantly increased superoxide radical formation as much as 4-fold. Pretreatment with 20 mg/kg vitamin C or 15,000 U/kg superoxide dismutase prevented GTN-induced nitroxide formation. The decrease of trapped radicals after treatment with extracellularly added superoxide dismutase or vitamin C leads to the conclusion that GTN increases the amount of extracellular superoxide radicals both in vitro and in vivo.

[Behavior of soft tissue structures in surgical leg lengthening]

Experimental animal studies and clinical investigations show three processes going on during extremity lengthening with the Ilizarov-method. At first degenerative changes including cell necroses in the muscles, the nerves and the tendons [corrected] occur as well as denervation of muscle fibers resulting in neurogenous muscle atrophies. These alterations are followed by reperative and regenerative processes as well as the reinnervation of the denervated muscle fibers. Secondly histoneogenesis occur which leads to a high increase of tissue-specific cells and a growth of the muscles, tendons and vessels. Therefore tensile-stress is an important factor of tissue growth. Thirdly adaptive processes proceed during leg lengthening. For example the high biosynthetic activity during tissue growth seems to indicate an increase of vasa vasorum.

Tolerance to nitrates with enhanced radical formation suppressed by carvedilol

Enhanced oxidant stress occurs under many pathophysiologic conditions (e.g., inflammation) and can be induced and mimicked by continuous nitrate therapy, eliciting increases in platelet activity, enhanced formation of reactive oxygen species (ROS), and impaired nitrate-induced vasorelaxation. Analysis was performed of effects of coinfusion of glycerol trinitrate (GTN) either with a carvedilol metabolite with antioxidant properties or with antioxidant vitamin C (Vit-C) on various hemodynamic parameters during enhanced oxidant stress associated with nitrate tolerance. Carvedilol metabolite (BM910228: 4.5 microg/kg/min) or Vit-C (55 microg/kg/min) was coadministered with GTN (1.5 microg/kg/min) for 5 days in chronically instrumented dogs. Changes in coronary diameters (CD) and other hemodynamic parameters were continuously monitored, as well as changes in platelet function. At the beginning of GTN treatment, CD increased by 9.8 +/- 0.4% and progressively declined to basal control values within 3 days. However, with additional antioxidant protection either with BM910228 or with Vit-C, the GTN-induced increase in CD was maintained (8.6 +/- 0.4% or 10.5 +/- 0.6%) and remained elevated for the entire infusion period. The thrombin-stimulated intracellular Ca2+ concentrations of platelets remained nearly unchanged during Vit-C or BM910228 in contrast to the increase with GTN. The basal cyclic guanosine monophosphate (cGMP) contents of platelets after GTN coadministered with BM910228 or with Vit-C increased on day 1 to 233 or to 250% versus control and remained at that level. Additional in vitro tests with xanthine oxidase-induced oxidant stress resulted in a more or less pronounced scavenging of O2- radicals by BM920228, Vit-C, or superoxide dismutase (SOD). Coadministration of carvedilol metabolite BM910228 or of Vit-C along with GTN suppressed noxious effects of GTN-induced oxidant stress such as increased platelet activity and impaired nitrate-induced vasorelaxation.

Behavior of blood vessels during lower-leg lengthening using the Ilizarov method

Using a ring fixator, lengthening of the right lower leg by 2.5 cm at a distraction rate of 2 x 0.5 mm per day was performed in 24 beagle dogs. After a postoperative latency period of 5 days and a distraction phase of 25 days, half the dogs were killed (30-day group). The remaining half were killed after a second interval of 25 days (55-day group). After the experiment, the anterior tibialis artery and vein with their supporting vessels, as well as the lesser saphenous vein of both the lengthened right side and the control side were excised and examined histologically, histomorphometrically, and electron microcopically. No morphologic changes of the vascular walls and no increase of collagenous or elastic fibers could be found. The histomorphometric evaluations showed a significant increase in the number of vasa vasorum in the dogs of both the 30- and 55-day groups. No significant difference in thickness of the vascular wall, tunica media, and adventitia could be observed between the lengthened and the control side in both dog groups. It seems that blood vessels can adapt to continuous tension during callus distraction without suffering structural damage and are the least limiting factor concerning distraction speed, distraction rhythm, and distraction length during callus distraction.

Biomechanical properties of tendons during lower-leg lengthening in dogs using the Ilizarov method

Ten dogs were provided with a circular fixator. Segment resection of the fibula and tibial osteotomy in the right lower leg was performed. 5 days after surgery, a lengthening of the right lower leg by 2.5 cm was performed on 6 dogs using a distraction rate of 0.5 mm, twice per day. 3 dogs with leg lengthening and 2 dogs of the control group without leg lengthening were sacrificed at the end of the distraction phase of 25 days and the remaining dogs after another 25 days. Postmortally the tendons of the tibialis anterior, extensor digitorum longus, peroneus longus and the achilles tendon were taken from the operated right side and the left non-operated control side and were examined biomechanically in cyclic tests. The control group without lengthening showed no changes in the biomechanical properties in the tendons of either side nor in those of the unlengthened left side of the operated dogs. In contrast the biomechanical tests revealed a marked decrease of the elastic modulus, an increase of distraction length and an increase of modulus reduction on the lengthened side compared to the non-operated left side.