Comparison of three surgical treatment options for unicameral bone cysts in humerus.

Treatment of unicameral bone cysts (UBC) in the humerus with drainage screws is scarcely reported in the literature. The aim of this retrospective study was to compare drainage screws and alternative treatment methods with respect to the number of required surgical procedures to achieve sufficient UBC healing, postoperative fractures/recurrences/complications, and radiological outcome. Medical archives of two tertiary orthopedic referral centers were screened for all patients who were treated surgically for humeral UBC in the period 1991-2015 with a histologically/cytologically confirmed diagnosis. Sex, age, all surgical procedures, fractures, complications, recurrences, and the final radiological outcome were compared between patients treated with drainage screws, elastic intramedullary nails, or curettage with optional grafting. The study included 106 operated patients with a mean age of 10.3 years, with a mean follow-up of 5.7 years. The average number of UBC-related surgical procedures in sex-matched and age-matched treatment groups was 2.7 with drainage screws, 2.8 with intramedullary nails, and 3.5 with curettage/grafting (P=0.54). Intramedullary nails (odds ratio 0.20) and older age (odds ratio for each year 0.83) predicted a lower risk of postoperative UBC recurrence. Patients with drainage screws had the highest UBC recurrence rates and the lowest rates of changed initial treatment method. There was no difference between the treatment groups in the postoperative fracture rate, complications, or the final radiological outcome. UBC treatment in the humerus therefore requires approximately three surgical procedures, irrespective of the treatment modality chosen. Adding an elastic intramedullary nail to a humeral UBC cyst may reduce recurrence risk and prevent further fractures. Level of Evidence: Level III - therapeutic retrospective comparative study.

Operative stabilization of the remaining mobile segment in ankylosed cervical spine in systemic onset - juvenile idiopathic arthritis: A case report.

We describe a case of a 19-year-old young man with oligoarthritis type of juvenile idiopathic arthritis, who presented with several month duration of lower neck pain and progressive muscular weakness of all four limbs. X-rays of the cervical spine demonstrated spontaneous apophyseal joint fusion from the occipital condyle to C6 and from C7 to Th2 with marked instability between C6 and C7. Surgical intervention began with anterolateral approach to the cervical spine performing decompression, insertion of cage and anterior vertebral plate and screws, followed by posterior approach and fixation. Care was taken to restore sagittal balance. The condition was successfully operatively managed with multisegmental, both column fixation and fusion, resulting in pain cessation and resolution of myelopathy. Postoperatively, minor swallowing difficulties were noted, which ceased after three days. Patient was able to move around in a wheelchair on the sixth postoperative day. Stiff neck collar was advised for three months postoperatively with neck pain slowly decreasing in the course of first postoperative month. On the follow-up visit six months after the surgery patient exhibited no signs of spastic tetraparesis, X-rays of the cervical spine revealed solid bony fusion at single mobile segment C6-C7. He was able to gaze horizontally while sitting in a wheelchair. Signs of myelopathy with stiff neck and single movable segment raised concerns about intubation, but were successfully managed using awake fiber-optic intubation. Avoidance of tracheostomy enabled us to perform an anterolateral approach without increasing the risk of wound infection. Regarding surgical procedure, the same principles are obeyed as in management of fracture in ankylosing spondylitis or Mb. Forestrier.

Cryopreservation with glycerol improves the in vitro biomechanical characteristics of human patellar tendon allografts.

PURPOSE: To evaluate the in vitro biomechanical characteristics of patellar tendon ligaments (BTB) when stored as fresh frozen or as glycerol cryopreserved allografts. METHODS: Seventy patellar tendons were harvested from 35 cadaveric human donors and randomly assigned into seven groups. Grafts in group FRESH were mechanically tested within 2 h of harvesting. FROZ-3, FROZ-6, and FROZ-9 were deep-frozen to -80 °C for 3, 6, and 9 months, respectively. Grafts in groups CRYO-3, CRYO-6, and CRYO-9 were initially incubated with 10% glycerol in a phosphate-buffered saline for 1 h and then stored in glycerol solution (10% glycerol in PBS) at -80 °C for 3, 6, and 9 months, respectively. Grafts were mechanically tested with two cycling modes (50-250 °N and 150-500 °N) and then loaded to failure. RESULTS: Cryopreserved grafts demonstrated more consistent results and expressed lower elongation rates after both cycling loading protocols compared to their frozen counterparts at all storage times. During load-to-failure analysis, ultimate stiffness levels were predominantly higher (23.9-61.5%) in cryopreserved grafts compared with frozen grafts, and ultimate stress levels were 26% (13.3-47.7%) higher, regardless of the storage time. Moreover, cryopreserved grafts revealed similar ultimate elongation and uniformly higher ultimate stiffness and ultimate stress levels compared to fresh grafts. CONCLUSION: The results of this in vitro study demonstrated superior mechanical properties of cryopreserved grafts compared to frozen grafts within a preservation period of 9 months. Cryopreservation with glycerol solution might be used to further improve the quality of preserved soft-tissue allografts.

Acetylcholinesterase is involved in apoptosis in the precursors of human muscle regeneration.

The best established role of acetylcholinesterase (EC 3.1.1.7, AChE) is termination of neurotransmission at cholinergic synapses. However, AChE is also located at sites, where no other cholinergic components are present and there is accumulating evidence for non-cholinergic functions of this protein. In the process of skeletal muscle formation, AChE is expressed already at the stage of mononuclear myoblast, which is long before other cholinergic components can be demonstrated in this tissue. Myoblast proliferation is an essential step in muscle regeneration and is always accompanied by apoptosis. Since there are several reports demonstrating AChE participation in apoptosis one can hypothesize that early AChE expression in myoblasts reflects the development of the apoptotic apparatus in these cells. Here we tested this hypothesis by following the effect of siRNA AChE silencing on apoptotic markers and by determination of AChE level after staurosporine-induced apoptosis in cultured human myoblasts. Decreased apoptosis in siRNA AChE silenced myoblasts and increased AChE expression in staurosporine-treated myoblasts confirmed AChE involvement in apoptosis. The three AChE splice variants were differently affected by staurosporine-induced apoptosis. The hydrophobic (H) variant appeared unaffected, a tendency towards increase of tailed (T) variant was detected, however the highest, 8-fold increase was observed for readthrough (R) variant. In the light of these findings AChE appears to be a potential therapeutic target at muscle injuries including organophosphate myopathy.

Synaptogenetic mechanisms controlling postsynaptic differentiation of the neuromuscular junction are nerve-dependent in human and nerve-independent in mouse C2C12 muscle cultures.

Acetylcholinesterase (EC 3.1.1.7, AChE) is one of the components of the neuromuscular junction (NMJ). Its expression and targeting in the skeletal muscle fiber is therefore under the control of the mechanisms responsible for the formation of the highly complex structure of this synapse. Recently, it has been demonstrated that myotubes of the C2C12 mouse muscle cell line form highly differentiated pretzel-like postsynaptic accumulations of acetylcholine receptors (AChRs) in the complete absence of the nerve if they are cultured on the laminin coating. This finding questions previously stressed importance of the nerve-derived factors in NMJ synaptogenesis and therefore deserves additional testing. The aim of this paper was to test whether the reported nerve-independency can be demonstrated also in the cultured human muscle meaning that the findings on C2C12 cultures can be extrapolated also to the human muscle. In our experiments aneurally cultured human myotubes failed to form AChR clusters on its surface, no matter if they were grown on normal gelatine or laminin coating. However, when innervated by neurons extending from the rat embryonic spinal cord, human myotubes formed AChR clusters with elaborate topography but strictly on the areas contacted by the nerve. One can hypothesize that higher nerve dependency of the NMJ synaptogenesis in humans in comparison to other species reflects species-specific differences in the organization of movement. Humans have the highest "fractionation of movement" capacity which probably requests different, more nerve-controlled development of the motor system including nerve-restricted development of the neuromuscular contacts.

Continuous decompression of unicameral bone cyst with cannulated screws: a comparative study.

We determined the role of mechanical decompression in the resolution of unicameral bone cyst. A total of 69 children with unicameral bone cysts were treated either by (i) open curettage and bone grafting, (ii) steroid injection or (iii) cannulated screw insertion. During a mean follow-up of 69 months (range, 12-58), the cysts were evaluated by radiological criteria. The healing rates in the three groups were 25, 12 and 29% after the first treatment, and a further 50, 19 and 65% after the second. The study has demonstrated the advantages of the decompression technique for unicameral bone cysts over other treatment modalities studied.

Colloidal 90Y used for radiation synovectomy decreases the viability of chondrocytes in human cadaveric samples.

OBJECTIVE: To analyse the early effect of colloidal 90Y beta irradiation, as used for radiation synovectomy (RSV), on the viability of human chondrocytes in an ex-vivo model. METHODS: Twenty osteochondral plugs (6 mm in diameter) were procured from femoral condyles of an adult male donor and stored in normal saline at 4 degrees C. The cartilage surfaces of 10 plugs were contaminated with colloidal 90Y citrate corresponding to the standard knee RSV dose (185 MBq) matched for the sample size (430 kBq). The remaining 10 plugs served as controls. At days 1, 2, 3, 6 and 13, two osteochondral plugs from each group were stained for viability with live/dead probes and scanned under a confocal laser microscope. The ratios of viable (green channel) and non-viable (red channel) pixels were acquired in four cartilage depth regions and statistically analysed with a regression model. RESULTS: The irradiation did not significantly alter the viable/non-viable pixel ratio during the first 2 days, but longer exposures led to a significant and time progressive reduction from 8.7% (day 3) to 12.5% (day 13). The ratio was less affected deeper in the cartilage, where it increased about 1% for every 100 microm from the surface. CONCLUSIONS: Surface exposure of human cadaveric cartilage to a therapeutic dose of colloidal 90Y decreased chondrocyte viability, expressed as the viable/non-viable pixel ratio, in the early post-irradiation period. The findings established in the ex-vivo simulation may reflect the changes in knee cartilage occurring after RSV therapy.

Radiation exposure of hemophiliacs after radiosynoviorthesis with 186Re colloid.

UNLABELLED: Very limited data are available in the literature on the doses of unwanted radiation that patients receive following treatment with radiosynoviorthesis (RSO). OBJECTIVE: The aim of this study was to assess the radiation exposure after RSO with (186)Re colloid in hemophiliacs. METHODS: This study involved 12 hemophiliacs who were treated for hemophilic joint disease with 14 RSOs by using (186)Re colloid. Whole-body scintigrams were performed 1, 6, and 24 hours and 3 and 7 days after RSO. Measurements, using a whole-body counter, were done immediately after scintigraphy, with the treated joint protected with a lead shield. The cumulative activity of (186)Re in the body and in the lymph nodes was calculated. The distribution of (186)Re in the body was determined by using the values for small colloids as proposed by the International Commission on Radiological Protection (ICRP) Publication 53. The computer code, OLINDA/EXM (Vanderbilt University, Nashville, TN), was used for the calculation of the internal dose. A constant distance of 1 m between the ankle joint and body organs, and of 0.33 m between the elbow or shoulder joint and body organs, was used to calculate the contribution of gamma radiation to the effective radiation dose. RESULTS: The mean effective dose received by hemophiliacs after RSO with (186)Re colloid was 28 +/- 9 microSv/MBq of the activity injected into the joint. The patients received 0.8-3.7 mSv (1.9 +/- 0.8 mSv) owing to the leakage of (186)Re from the treated joint and its retention in the body. The highest doses were established in the spleen (26.0 +/- 10.7 mGy), the liver (17.6 +/- 7.2 mGy), and red marrow (3.0 +/- 0.8 mGy). The contribution of gamma radiation to the effective dose was less than 0.1 mSv in RSO of the ankle, 0.4 mSv in the elbow, and 0.6 mSv in the shoulder-joint treatment. The activity of (186)Re in the regional lymph nodes was noted in 4 of the 14 treatments. In these cases, the estimated average dose received by individual lymph nodes was 14.7 +/- 1.9 Gy. CONCLUSIONS: RSO with (186)Re colloid is a safe treatment method. The effective dose received by patients after RSO by using (186)Re colloid is low, as are the radiation doses to the most exposed organs. If (186)Re is retained in the regional lymph nodes, the lymph node radiation dose would be high.

Expression and distribution of acetylcholinesterase among the cellular components of the neuromuscular junction formed in human myotube in vitro.

The results of our recent investigations on the expression and distribution of acetylcholinesterase (EC. 3.1.1.7, AChE) in the experimental model of the in vitro innervated human muscle are summarized and discussed here. This is the only model allowing studies on AChE expression at all stages of the neuromuscular junction (NMJ) formation in the human muscle. Since it consists not only of the motor neurons and myotubes but also of glial cells, which are essential for the normal development of the motor neurons, NMJs become functional and differentiated in this system. We followed AChE expression at various stages of the NMJ formation and in the context of other events characteristic for this process. Neuronal and muscular part were analysed at both, mRNA and mature enzyme level. AChE is expressed in motor neurons and skeletal muscle at the earliest stages of their development, long before NMJ starts to form and AChE begins to act as a cholinergic component. Temporal pattern of AChE mRNA expression in motor neurons is similar to the pattern of mRNA encoding synaptogenetic variant of agrin. There are no AChE accummulations at the NMJ at the early stage of its formation, when immature clusters of nicotinic receptors are formed at the neuromuscular contacts and when occasional NMJ-mediated contractions are already observed. The transformation from immature, bouton-like neuromuscular contacts into differentiated NMJs with mature, compact receptor clusters, myonuclear accumulations and dense AChE patches begins at the time when basal lamina starts to form in the synaptic cleft. Our observations support the concept that basal lamina formation is the essential event in the transformation of immature neuromuscular contact into differentiated NMJ, with the accumulation of not only muscular but also neuronal AChE in the synaptic cleft.

Radiosynoviorthesis for treatment of hemophilic hemarthrosis--Slovenian experience.

UNLABELLED: Radiosynoviorthesis is a well-accepted method for the treatment of recurrent hemarthrosis in hemophilic patients. OBJECTIVES: The aims of our study were to evaluate the effectiveness of radiosynoviorthesis in patients suffering from hemophilic hemarthrosis, to determine the effect of treatment on antihemophilic factor consumption, and to assess the patient's satisfaction with radiosynoviorthesis. METHODS: Between 2001 and 2003, 26 radiosynoviortheses were done in 21 hemophilic patients; in 4 patients the treatment was repeated, and in 1 patient two joints were treated. 90Y colloid was used for the knee joint, and 186Re colloid was used for ankle, shoulder, and elbow radiosynoviorthesis. RESULTS: The bleeding frequency decreased by at least 50% in 53% of patients in the year after radiosynoviorthesis, as compared to the year prior to the therapy. Considering only those patients who had at least 12 bleedings into the treated joints in the year preceding the therapy, the bleeding frequency decreased by at least 50% in 62% of these patients. In this group, the consumption of the antihemophilic factor was notably reduced (on average, by 25,800 I.U./year). All patients reported that the treated joint was much better or better than before the radiosynoviorthesis. CONCLUSION: Radiosynoviorthesis is an effective method for the treatment of hemophilic hemarthrosis, particularly in patients with frequent intra-articular bleedings. The antihemophilic factor consumption was markedly reduced only in patients with frequent joint bleeding. Radiosynoviorthesis is well accepted by patients suffering from hemophilic hemarthrosis.

Modelling the state of bone cysts by statistical analysis of intensities of x-ray images.

The subject of this article is the state of a benign bone disease. The principle aim of this study is the construction of a statistical model for estimating the otherwise unobservable variable for the state of the disease. The distribution of intensity of X-ray images of the affected part and the healthy part of the bone are evaluated. Quantiles of both distributions are used in the estimation of a multinomial logit model by which the variable for the state of the disease is quantified.