A comparative study of low-level laser efficacy on autologous activity of PRP injected in knee arthritis, in vivo study

There were many studies that attempt to measure the effect of growth factors of platelets through platelet-rich plasma (PRP) techniques on repairing of different human tissues and their efficiency either by platelets account or measuring the concentrations of growth factors secreted from platelets at various experimental conditions, to get the optimal parameters for platelets functions in healing processes. There were little trails dealing with laser and PRP for accelerating healing process that generally takes two methods, either by studding the stimulation effect of LLLT (low-level laser therapy), by subjecting laser irradiation on injured part and left for a period of time that is necessary for photobiostimulation of cell proliferations, then PRP treatment followed, or by studding the direct effects of laser on PRP factors activity. The objectives of this study are to investigate the indirect and prolonged influence of laser irradiation (650 nm with 100 mW output power) on healing processes of knee joints with induced osteoarthritis (OA), by comparison of radiated and non-radiated PRP on repairing of joint cartilage. In material and methods, we used 9 rats divided in to four groups: C1, control without any treatment, for positive comparisons of healing; C2 and C3, controls with induced OA, left for 14 days, then sacrificed for histological analysis of negative comparisons; and P and L groups that had induced with OA for 14 days and then treated with non-irradiated and radiated PRP, respectively. Preparation of PRP (condensed platelets account with high concentration of growth factors) in order to accelerate repairing processes on induced- osteoarthritis cartilage in rats groups. To estimate the efficacy of photobiostimulation or photobioinhibition on platelets' granules, we determine the absorbance of PRP by spectrophotometer. The technique was based on PRP, as a feature of platelets quantity, that compares the quality of PRP on healing of induced osteoarthritis with and without irradiation of laser, using Wistar rats as a model. The quality of platelets was measured by time required for healing according to histopathological observations and grades of OA. Finally, the results were analyzed statistically using ANOVA test (P = 0.05). Our conclusion was emphasizing the idea of inhibiting the effect of LLLT on growth factors of PRP that is responsible of speed up healing of OA.

[Contemporary use of radiosynoviorthesis in chronic polyarthrtitis]

Radiosynoviorthesis is used for local treatment of recurrent joint effusions, leads to necrosis of inflamed synovium due to beta radiation energy served after intraarticular radionuclide administration. The aim of the therapy is destruction and fibrosis of abnormal, hypertrophic synovial membrane and then full recovery of its normal function after local corticosteroids and systemic modifying drugs failure. Radiosynoviorthesis is effective in different type of peripheral arthritis like rheumatoid arthritis, inflammatory spondyloarthtropaties, gout, chondrocalcinosis, pigmented villo-nodular synovitis, recurrent knee effusion after total joint replacement, idiopathic knee joint effusion, osteoarthritis and secondary prevention of intraarticular bleeding in haemophilia. The absolute contraindications are: pregnancy and breastfeeding, uncontrolled coagulation disorders in haemophilic patients, septic skin changes around area of joint puncture, septic arthritis, raptured Baker's cyst. The commonly used radioisotypes in Europe are: 90Yttrium, 186Rhenium, 169Erbium. The favourable results could be reached on average in 60-80% of treated joints regardless of radionuclide used. The efficacy of radiosynoviorthesis is comparable with surgical synovectomy and in some selected situations both methods could be combined. If the primary failure of radiosynoviorthesis appeared procedure could be repeated, good results are obtained very frequently regardless of poor primary effect. Radiosynoviorthesis is safe, effective, simple and patient-friendly procedure, working fast in different type of arthtritis. The team consisted of rheumatologist, orthopedic surgeon and nuclear medicine specialist is essential for proper indications for local radiation therapy.

Does sequence of graft tensioning affect outcomes in combined anterior and posterior cruciate ligament reconstructions?

BACKGROUND

Controversy persists regarding the protocol for tensioning and securing the grafts in one-stage reconstruction of combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries. Many authors have reported stability examinations and functional results after reconstruction for this relatively rare injury, and the best sequence for tensioning the grafts is not known.

QUESTIONS/PURPOSES

We sought to determine (1) if there are differences in postoperative anteroposterior stability in a protocol of simultaneous tensioning of both grafts and ACL-first fixation compared with a protocol of tensioning and fixation of the PCL first in one-stage reconstruction of combined ACL/PCL injuries; and (2) if there is a difference in postoperative functional outcome scores between the two protocols.

METHODS

Between 2001 and 2011, 29 patients underwent one-stage reconstruction of combined ACL and PCL injuries (the majority with medial collateral ligament [MCL] injuries, posterolateral corner [PLC] injuries, or both, in addition), of whom three patients (10%) were lost to followup before 2 years, and one patient was excluded based on predefined criteria, leaving a total of 25 patients (86%) for retrospective analysis in this report. Fourteen patients underwent one-stage reconstruction of these injuries with tensioning and fixation of the PCL graft first (PCL-first group), and 11 later patients underwent one-stage reconstruction of combined ACL/PCL injuries with simultaneous tensioning of both grafts and fixation of the ACL graft first (simultaneous-tensioning group). During the period in question, the technique used in the PCL-first group was used exclusively for these injuries between August 2001 and August 2008 and that used in the simultaneous-tensioning group was used between September 2008 and August 2011; there was no overlap between groups. The groups were similar in terms of demographics and length of followup. Each patient was assessed for associated injuries, preoperative and postoperative knee stability with anteroposterior stress radiographs, and was evaluated with the Lysholm knee score and International Knee Documentation Committee (IKDC) subjective and objective grading at the last followup after surgery.

RESULTS

At the last followup evaluation, patients treated with simultaneous tensioning and ACL-first fixation showed less instability on side-to-side difference of posterior stress radiography (5±1 mm in the simultaneous-tensioning group versus 6±1 mm in the PCL-first group; effect size, 1.2; 95% confidence interval [CI], 0.5-2.3; p=0.011), but with the numbers available, no difference on anterior stress radiography (3±0.4 mm in the simultaneous-tensioning group versus 3±0.5 mm in PCL-first group; effect size, 0.4; 95% CI, -0.2 to 0.5; p=443). The simultaneous-tensioning group also had higher Lysholm knee scores (87±5 in the simultaneous-tensioning group versus 80±4 in the PCL-first group; effect size, 1.8; 95% CI, -10.9 to -2.7; p=0.001), IKDC subjective scores (68±3 in the simultaneous-tensioning group versus 58±3 in the PCL-first group; effect size, 3.4; 95% CI, -14.2 to -8.6; p<0.001), and IKDC objective grades (p=0.037).

CONCLUSIONS

In one-stage reconstruction of combined ACL and PCL injuries, a protocol of simultaneous tensioning both grafts and fixing the ACL graft first may be worth consideration. Arthroscopic reduction landmarks may prove helpful in this technique but require further validation.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Monte Carlo simulation of skull and knee voxel phantoms for the assessment of skeletal burden of low-energy photon emitters

In case of internal contamination due to long-lived actinides by inhalation or injection pathway, a major portion of activity will be deposited in the skeleton and liver over a period of time. In this study, calibration factors (CFs) of Phoswich and an array of HPGe detectors are estimated using skull and knee voxel phantoms. These phantoms are generated from International Commission of Radiation Protection reference male voxel phantom. The phantoms as well as 20 cm diameter phoswich, having 1.2 cm thick NaI (Tl) primary and 5cm thick CsI (Tl) secondary detector and an array of three HPGe detectors (each of diameter of 7 cm and thickness of 2.5 cm) are incorporated in Monte Carlo code 'FLUKA'. Biokinetic models of Pu, Am, U and Th are solved using default parameters to identify different parts of the skeleton where activity will accumulate after an inhalation intake of 1 Bq. Accordingly, CFs are evaluated for the uniform source distribution in trabecular bone and bone marrow (TBBM), cortical bone (CB) as well as in both TBBM and CB regions for photon energies of 18, 60, 63, 74, 93, 185 and 238 keV describing sources of (239)Pu, (241)Am, (238)U, (235)U and (232)Th. The CFs are also evaluated for non-uniform distribution of activity in TBBM and CB regions. The variation in the CFs for source distributed in different regions of the bones is studied. The assessment of skeletal activity of actinides from skull and knee activity measurements is discussed along with the errors.

Use of radiosynovectomy in recurrent warfarin-related haemarthrosis in degenerative arthritis

Radiosynovectomy is a local and minimally invasive radiotherapy for treating various chronic inflammatory arthritis such as rheumatoid arthritis, osteoarthritis and haemophilic arthropathy. In haemophilic arthropathy, it reduces the frequency of haemarthrosis and delays the development of severe joint destruction, which ultimately requires surgical intervention. Its role in warfarin-related haemarthrosis is less clear. Haemarthrosis is an uncommon complication of warfarin use, and anticoagulation may need to be discontinued. We describe yttrium-90 radiosynovectomy use in a 74-year-old man with underlying ischaemic heart disease, atrial fibrillation, previous embolic stroke and recurrent haemarthrosis of an osteoarthritic right knee. Anticoagulation was vital and could not be permanently stopped. Due to continuing anticoagulation, he had multiple hospitalisations with recurrent right knee haemarthrosis. Intraarticular right knee yttrium-90 citrate colloid injection led to a cessation of haemarthrosis for eight months. We examined the available literature for the role of radiosynovectomy in such circumstances.

Extracorporeal shockwave therapy shows chondroprotective effects in osteoarthritic rat knee

PURPOSE

This study investigated the effects of extracorporeal shockwave therapy (ESWT) on the subchondral bone and articular cartilage in the initiation of osteoarthritis of the knee in rats.

METHODS

Anterior cruciate ligament transected (ACLT) osteoarthritis (OA) rat knee model was used in this study. Twenty-seven male Sprague-Dawley rats were divided into three groups. The control group underwent sham surgery without ACLT and received no ESWT. The ACLT group underwent ACLT, but received no ESWT. The ACLT plus ESWT group underwent ACLT and received ESWT immediately after surgery. The evaluation parameters included radiograph, bone mineral density, serum levels of cartilage oligometric protein and osteocalcin, and urinary concentration of C-telopeptide of type II collagen (CTX-II), and histomorphological examination.

RESULTS

At 12 weeks, OA of the knee was radiographically verified in the ACLT group, but very subtle changes were noticed in the control and the ACLT plus ESWT groups. On articular cartilage, the ACLT group showed significant increases in cartilage degradation and chondrocyte apoptosis compared to the control and ACLT plus ESWT groups. The ACLT plus ESWT group demonstrated significant decrease in the cartilage degradation and an increase in chondrocyte activity comparable to the control. In subchondral bone, the ACLT group showed a significant decrease in bone remodeling as compared to the control and ACLT plus ESWT groups. The ACLT plus ESWT group showed significant improvement in bone remodeling comparable to the control.

CONCLUSION

Extracorporeal shockwave therapy shows chondroprotective effect associated with improvement in subchondral bone remodeling in the initiation of ACLT OA knee model in rats.

In vivo CT quantification of trabecular bone dynamics in mice after sciatic neurectomy using monochromatic synchrotron radiation

We demonstrated the capability of in vivo synchrotron radiation CT (SRCT) in analyzing short-term changes in trabecular bone architecture (TBA) and the degree of bone mineralization (DBM) in small animals. Mice underwent unilateral sciatic neurectomy (SN) and sham operation on the contralateral side (SO) at 13 weeks of age. In vivo SRCT scans (11.7-μm cubic voxel) were made of both knees 7 and 17 days (group 1, n = 7) or only 17 days (group 2, n = 6) after surgery. In three mice in group 2, one knee was scanned twice on the same day in different orientations for reproducibility testing. Two scan data sets of the tibial proximal metaphysis acquired at different time points (group 1) or at the same time point (group 2) were registered for detecting differences in volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), connectivity density (Conn.D), and mean DBM (mDBM). The reproducibility test showed small errors of <2.5% in the TBA indexes and <3.0% in mDBM, while mismatched bone regions amounted to >25%. In group 1, Tb.Th increased but Tb.N and Conn.D decreased in both SN and SO; BV/TV and mDBM increased only in SO; accordingly, BV/TV, Tb.Th, and mDBM became lower in SN than in SO. No significant interaction between SN and irradiation was found; the SN effects on TBA and DBM were similar between groups 1 and 2, although synchrotron irradiation led to higher Tb.Th and lower Tb.N in group 1. In conclusion, in vivo SRCT has potential use for detecting short-term bone dynamics of small animals.

Effects of low-intensity swimming on radiation-induced leg contracture in mice

OBJECTIVE

To evaluate the effects of low-intensity swimming on radiation-induced leg contracture.

METHODS

Forty mice were randomly and equally divided into four groups: 1) irradiation; 2) swimming before irradiation; 3) swimming after irradiation; 4) swimming after contracture, and their left hind legs were exposed to gamma irradiation of 60 Gy. The mice were allowed to swim freely for 10 minutes, three times per day. For group 2, the mice were allowed to swim for only 1 week before irradiation. For group 3, the mice were allowed to swim immediately after irradiation until day 130, post-irradiation. For group 4, the mice were allowed to swim after leg contracture happened (on day 30 post-irradiation) until day 130, post-irradiation. The leg lengths and knee joint angles were measured. Leg contracture was defined as the decrease in the hind leg lengths and the knee joint angles of each animal. The ultrastructural changes of gastrocnemius muscles were observed using transmission electron microscopy.

RESULTS

The radiation could result in leg contracture and mitochondrial injury of the muscles. However, the group of swimming immediately after irradiation had less leg contracture and no vacuolar degeneration in the mitochondria, compared with the other groups.

CONCLUSION

Low-intensity swimming that began immediately after the mice were irradiated could effectively prevent the irradiated legs from contracture. Patients with irradiated mastication muscles were recommended to begin mouth-opening exercises immediately after radiotherapy.

Radioprotectant combinations spare radiation-induced damage to the physis more than fractionation alone

PURPOSE

The aim of this study was to determine if fractionation and individual or combinations of radioprotectants could minimize damage to physeal longitudinal growth in an animal model to any greater extent than fractionation alone.

MATERIALS AND METHODS

Sixty-three weanling male Sprague-Dawley rats were randomized into seven equal groups. Five groups received a total 25 Gy radiation exposure in three equal fractions to the right knee with the left as non-irradiated control. For each group, pentoxifylline, misoprostol, and amifostine were given individually and amifostine was also given in combination with each of the other drugs prior to the radiation fractions. One group each received 25 Gy in one or three fractions without radioprotection. At six weeks, limb lengths and histomorphometry were assessed.

RESULTS

The single fraction of 25 Gy caused a mean tibial length discrepancy of 24.4%. Fractionation decreased this to 18.8% (p < 0.001). Beyond fractionation alone, the mean femoral length discrepancies were significantly decreased by each of the added individual and combination radioprotectant drugs (p < 0.0004). The smallest absolute femoral length discrepancy (11%) was achieved with fractionation and the combination of amifostine and misoprostol.

CONCLUSIONS

Radioprotectants may be beneficial in growth plate radioprotection, alone or in combination.

[Radiosynovectomy of the knee--experience thereof]

The aim of the study was the evaluation of 90Y radiosynovectomy performed in chronic exudative knee synovitis. The analyzed material comprised 81 90Y injections made between 2004 and 2008. The circumference of a knee, the volume of removed exudate, the knee mobility, the presence of pain, the temperature of a knee and the presence of floating patella (exudate) were evaluated. The percentage of pain-free patients increased from 12% to 50% after 1 year; an additional 10% of patients reported pain relief. The patient percentage with an increased knee temperature fell from 42% to 31% and the patients percentage with exudates decreased from 76% to 27. No improvement was found with respect to knee circumference. The knee mobility improvement (the patients percentage with full mobility) increased from 25% to 59% one month after the treatment) and exudate volume reduction was found only in the subgroup of patients suffering from pigmented villonodular synovitis. The obtained results permit the conclusion that 90Y radiosynovectomy for chronic exudative knee synovitis is an effective treatment modality; it relieves pain and reduces the patients percentage with exudate and increased knee temperature, and in the subgroup of patients suffering from the pigmented villonodular synovitis improves the knee mobility and reduces the volume of evacuated exudate.

Lipoma arborescens; successfully treated by yttrium-90 radiosynovectomy

Although radiosynovectomy (RS) applications have been carried out for many years, clinical indications of this non-invasive procedure is thought to be limited probably due to the lack of information of clinicians. Clinicians' preferential indication for RS is the treatment-resistant synovitis of individual joints, i.e. despite systemic pharmacotherapy and intra-articular steroid injections. We present here a case of "lipoma arborescens" treated by yttrium-90, which is a rare intra-articular lesion characterized by villous proliferation of the synovial membrane and hyperplasia of subsynovial fat. The results of clinical, biochemical and hematological examinations, magnetic resonance (MR) imaging, arthroscopy and histological analysis have shown that the etiology was lipoma arborescens in a female patient, aged 36 having swelling and sometimes associating pain at her right knee for 4 years. We have applied to our patient's right knee RS with 185 MBq yttrium-90 colloid together with 40 mg of methylprednisolone acetate, although in our literature survey we have not met any similar case being treated with such indication. Even a year after the application, the patient has absolutely benefited from the treatment clinically, and this was also confirmed by comparative MR images (pre- and post-treatment). Consequently, we consider that Y-90 treatment might be applicable in suitable cases with lipoma arborescens.

Radiation synovectomy with 90Y colloid in the therapy of recurrent knee joint effusions in patients with inflammatory joint diseases

The aim of this study was to assess the effectiveness of radiation synovectomy (RSV) in the treatment of recurrent joint effusions, using 90Y in patients with chosen inflammatory joint diseases. The group of treated patients consisted of 30 people. Qualification for the treatment was based on clinical assessment, three-phase bone scintigraphy (BS3) and biochemical analysis. Intra-articular injection of 90Y was performed. Biochemical analysis was repeated after 48 h, 4 and 24 weeks, whereas BS3 was repeated after 24 weeks. Changes in the second phase of BS3 were assessed visually, using a four-degree scale and in the third phase, semiquantitatively with J/B ratio. The changes in the blood pool phase before RSV were 3.4 +/- 0.6 and after the therapy 2.00 +/- 0.8 (P < 0.001). The J/B ratio was: before RSV 2.58 +/- 08; after treatment 2.09 +/- 0.9 (P < 0.05). RSV is an effective method to treat recurrent effusions in patients with RA and SPA.

[Effectiveness evaluation of knee joint 90Y radiosynovectomy]

INTRODUCTION

Chronic knee synovitis with effusion, because of the special role of knee joint is an important therapeutic problem. This leads to searching for new treatment modalities. One of them is radiosynovectomy based on anti-proliferative and anti-inflammatory activity of ionizing radiation. It is made using 90Y mainly (high energy of beta [electrons] radiation [2.2 MeV], large average penetration in soft tissues [3.6 mm] and long physical half-life [2.7 days]).

MATERIAL AND METHOD

Analyzed material is comprised of 30 patients (33 treatments) suffering from proliferative synovitis of knee joint treated by radiosynovectomy using intra-articular injection of 6 mCi 90Y. In 20 cases the reason of disease was non-specific reactive arthritis, in 5 rheumatoid arthritis, in 3 villonodular synovitis, in 3 psoriasis and in 2 ulcerative colitis. Symptoms duration varied from 3 to 144 months (mean 43). A knee circumference at the treatment day varied from 33.5 cm to 49 cm (mean 41). The operation was based on knee biopsy, evacuation of exudate and delivery of 6 mCi of colloid 90Y. Follow up ranged up to 14 months (mean 4.4). Patients were examined 2 weeks, 1, 3, 6 and 12 months after treatment. During examination a knee circumference was measured, a knee mobility, temperature and patella floating symptom were examined. Pain in treated region was assessed and amount of exudate was measured.

RESULTS

A knee circumference and exudate amount enlarged during following controls, and compared between the treatment day and the last control did not differ significantly (41 vs. 41.6 cm and 43 vs. 42.5 ml respectively) but number of biopsies decreased. A percentage of patients with impaired knee mobility also did not change (59% vs. 58%). Probably, it was caused by resignation from control examination when symptoms disappeared. A percentage of patients without pain relief decreased from 43.5% 2 weeks after treatment to 20% one year later and a patient percentage with complete pain relief increased from 8.5% to 60%. A patient percentage with increased knee temperature and with floating patella decreased significantly (54 vs. 25% and 83 vs. 48% respectively).

CONCLUSIONS

Obtained results do not allow to form univocal conclusions regarding effectiveness of 90Y radiosynovectomy. The decreasing biopsies number, decreasing percentage of patient with increased knee temperature and with floating patella; increased percentage of patients with analgetic effect and with total pain relief show a necessity of renewed evaluation of this treatment modality on the base of bigger patients number and longer and more precise observation.

Associated risk factors of knee osteoarthritis: a population survey in Taiyuan, China

BACKGROUND

Since knee osteoarthritis (KOA) is one of the common diseases, identification of its associated risk factors is of preventive significance. This investigation was designed to investigate the prevalence of KOA in Taiyuan, and identify the associated risk factors of KOA.

METHODS

A population sample was surveyed of 2188 adults aged from 35 to 64 years, living in 6-story buildings without elevators. The protocol of Asia Pacific League of Associations for Rheumatology (APLAR) Community Oriented Program for Control of Rheumatic Diseases (COPCORD) core questionnaire was implemented. The data on knee pain and KOA were collected and analyzed. Variables such as sex, age, body mass index (BMI), waist circumference (WC), education level, and smoking history, were included in binary logistic regression model for further analysis.

RESULTS

The prevalence rates of knee pain and KOA were 13.6% and 10.9%, respectively, significantly higher than those in Shantou of south China and similar to those in Beijing of north China. The prevalence of KOA was significantly higher in women than in men (18.3% versus 8.7% and 15.1% versus 6.3%), with a tendency of increase with age. The prevalence was increased more obviously in women after 40 years old and in men after 45 years old. BMI in KOA group was significantly higher than that in non-KOA group. Binary Logistic regression revealed that age, sex, and BMI were significantly associated with KOA, whereas no significant correlation was seen between KOA and other factors such as climbing stairs, WC, time length of occupation service, education level, smoking history and religious belief.

CONCLUSION

Geography, age, sex, and BMI might be the risk factors of KOA, but climbing stairs, WC, time length of occupation service, education level, smoking history and religious belief are not correlated with KOA. Prevention of KOA should be initiated before the middle-age, especially in female adults, and weight control is necessary. Other factors might also contribute to the development of KOA, but further study is needed to elucidate the role of these factors.

Mid-IR laser ablation of articular and fibro-cartilage: a wavelength dependence study of thermal injury and crater morphology

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate areas of collateral thermal injury and crater morphology for evidence of wavelength-dependent effects on the ablation of articular cartilage and fibro-cartilage (meniscus) using selected mid-IR wavelengths produced by a free electron laser.

STUDY DESIGN/MATERIALS AND METHODS

Two types of cartilage, articular cartilage and fibro-cartilage were used in the study. The wavelengths (lambda) evaluated were 2.79, 2.9, 6.1, and 6.45 microm generated by a free electron laser (FEL) using a 4 microseconds macropulse configuration. The zone of thermal injury and crater morphology produced by laser ablation were examined by light microscopy following standard histologic processing.

RESULTS

The zone of thermal injury and crater morphology created in cartilage by the FEL at selected mid-IR wavelengths were examined as a function of incident radiant exposure. Ablation using lambda = 6.1 microm provided the largest crater size for both articular and fibro-cartilage at all radiant exposures. For the zones of collateral thermal injury in articular cartilage, lambda = 6.1 microm produced the least thermal injury at the radiant exposure of 7.6 J/cm2. When the radiant exposure is increased to 20.4 J/cm2, both lambda = 6.1 and 6.45 microm produced less thermal injury than the ablation using lambda = 2.79 and 2.9 microm. The greatest amount of collateral thermal injury was produced by lambda = 2.79 microm for both tissue types.

CONCLUSIONS

The results demonstrate that crater depth and collateral thermal injury produced in articular cartilage and fibro-cartilage are wavelength-dependent with 6.1 microm providing the largest craters at all radiant exposures. The least amount of thermal injury was created in articular cartilage using lambda = 6.1 microm at the radiant exposure of 7.6 J/cm2. Both 6.1 and 6.45 microm wavelengths demonstrated similar amount of thermal injury at 20 J/cm2 that was less than lambda = 2.79 and 2.9 microm at similar fluences. These observations are explained based on the absorption by water and protein in the tissue types studied. It is further observed that the use of crater dimensions may not provide a reliable estimate for the amount of tissue removal provided by an ablation procedure.

Serious complications after radiosynoviorthesis. Survey on frequency and treatment modalities

AIM

Radiosynoviorthesis using intraarticular injection of beta-emitting radiocolloids is increasingly performed throughout Europe in patients with inflammatory joint disease. It is a cost-effective and safe treatment, local complications are very rare with only eight cases mentioned in the literature so far. No recommendations for therapy of tissue necrosis, infection or thromboembolism after radiosynoviorthesis are available.

METHODS

Using a standardized questionary, 260 nuclear medicine physicians and 20 medical liability insurances were asked for the kind and frequency of complications after radiosynoviorthesis between 1998 and 2003. The survey was terminated after nine months with a response of only 25.7%.

RESULTS

A total of 53 severe complications were documented (28 necroses, 12 thromboses, 13 joint infections). Eight other complications were seen but difficult to correlate directly with radiosynoviorthesis. Tissue necroses from yttrium-90 were successfully treated by surgical excision and closure of the defect. Rhenium-186-induced ulcers healed by hyperbaric oxygen therapy in two cases. Lesions from erbium-169 showed restoration by conservative treatment. Thromboembolic events happened after radiosynoviorthesis in joints of the lower limb only, mostly treated by conventional anticoagulation. Intraarticular infections showed restoration after intraarticular antibiotics in the majority of cases.

CONCLUSION

Severe complications after radiosynoviorthesis seem to be rare. However, because of the low return rate, a reliable frequency cannot be calculated. Nevertheless, important advices regarding treatment concepts can be taken from our data.

Pulsed electromagnetic fields reduce knee osteoarthritic lesion progression in the aged Dunkin Hartley guinea pig

An experimental in vivo study was performed to test if the effect of Pulsed Electromagnetic Fields (PEMFs) on chondrocyte metabolism and adenosine A2a agonist activity could have a chondroprotective effect on the knee of Dunkin Hartley guinea-pigs of 12 months with spontaneously developed osteoarthritis (OA). After a pilot study, 10 animals were randomly divided into two groups: PEMF-treated group (6 h/day for 3 months) and Sham-treated group. Microradiography and histomorphometry were performed on the entire articular surface of knee joints used in evaluating chondropathy severity, cartilage thickness (CT), cartilage surface Fibrillation Index (FI), subchondral bone plate thickness (SBT) and histomorphometric characteristics of trabecular epiphyseal bone. The PEMF-treated animals showed a significant reduction of chondropathy progression in all knee examined areas (p<0.05). CT was significantly higher (p<0.001) in the medial tibia plateaus of the PEMF-treated group when compared to the Sham-treated group. The highest value of FI was observed in the medial tibia plateau of the Sham-treated group (p<0.05). Significant lower values were observed in SBT of PEMF-treated group in comparison to Sham-treated group in all knee examined areas (p<0.05). The present study results show that PEMFs preserve the morphology of articular cartilage and slower the progression of OA lesions in the knee of aged osteoarthritic guinea pigs. The chondroprotective effect of PEMFs was demonstrated not only in the medial tibial plateau but also on the entire articular surface of the knee.

Reradiosynoviorthesis of the Knee

The aim of this study was to compare the treatment results between radiosynoviorthesis and reradiosynoviorthesis of knees. Before the radiosynoviorthesis, an ultrasonography, X-ray, and three-phase bone scintigraphy were done. The treatment effect can be expected if a synovitis is proved by these examinations. To knees, 200 MBq of the yttrium citrate was injected for the first radiosynoviorthesis or for reradiosynoviorthesis. After an application, it is possible to do the scintigraphic examination, when information about a tracer distribution in joints is obtained. The treatment effect was evaluated by the clinical examination, the ultrasonography, and the three-phase bone scintigraphy with some lapse of time. If the effect of the radiosynoviorthesis was not satisfying, it could be repeated no sooner than 6 months later. Among our patients we had a high percentage of the repeated radiosynoviorthesis. The authors applicated the yttrium citrate to 1243 knees. A rate between single radiosynoviorthesis and reradiosynoviorthesis was 11:8. Repeated radiosynoviorthesis were as effective as the initial ones, and their repeated use does not decrease the expected therapeutic effect.

Evaluation of 90Y phosphate particles as a possible radiation synoviorthesis agent

BACKGROUND

90Y is one of the radioisotopes used extensively for therapy due to its favourable nuclear characteristics. Particles and colloids incorporating 90Y are being used for radiation synovectomy, especially in European countries.

METHODS

In our present work, 90Y phosphate particles were prepared and evaluated for use in radiation synovectomy. The radioactive particles were prepared by reacting carrier added 90YCl3 with phosphoric acid.

RESULTS

The radiolabelling yield obtained was >95%. The particles were found to be stable in saline for up to 7 days of study at 37 degrees C. Particle size analysis of inactive yttrium phosphate showed that most of the particles were in the size range of 2-20 microm. Biodistribution studies carried out by intra-articular injection of the particles into the knee joints of rats showed that approximately 99% of the particles were retained in the joints with negligible radioactivity in the major organs even at 48 h post-injection. Scintigraphic studies in rabbit showed that >99% of the radioactive particles were retained in the knee joint even at 96 h post-injection. No significant radioactivity above background was detected in the blood.

CONCLUSION

The promising results warrant further studies on 90Y phosphate particles for use in radiation synovectomy.

Thermal Damage Prediction for Collagenous Tissues Part I: A Clinically Relevant Numerical Simulation Incorporating Heating Rate Dependent Denaturation*

Subablative thermotherapy is frequently used for the treatment of joint instability related diseases. In this therapy, mechanically deformed collagenous tissues are thermally shrunk and the stability of the tissue is re-established. In this research, the thermal damage fields generated by three different clinical heating modalities (monopolar and bipolar radio frequency and Ho:YAG laser) are compared numerically using finite element analysis. The heating rate dependent denaturation characteristics of collagenous tissues are incorporated into the model using experimental data from in vitro experimentation with rabbit patellar tendons. It is shown that there are significant differences among the thermal damage profiles created by these modalities, explaining the main reason for the discrepancies reported in the literature in terms of the efficacy and safety of each modality. In the complementary paper, the accuracy of the model presented here is verified by in vitro experimentation with a model collagenous tissue and by quantifying the denaturation-induced birefringence change using Optical Coherence Tomography and Magnetic Resonance Imaging.

Microbubble-enhanced ultrasound exposure promotes uptake of methotrexate into synovial cells and enhanced antiinflammatory effects in the knees of rabbits with antigen-induced arthritis

OBJECTIVE

To evaluate whether microbubble-enhanced ultrasound (US) treatment promotes the delivery of methotrexate (MTX) into synovial cells and the enhanced antiinflammatory effects of intraarticular MTX therapy in a rabbit arthritis model.

METHODS

Arthritis was induced in both knees of 53 rabbits by immunization with ovalbumin. MTX including a microbubble agent was then injected into the left and right knee joints, and the right knees were exposed to US (MTX+/US+ group), while the left knees were not (MTX+/US- group). The knee joints were evaluated histologically in 7 rabbits at 5 time points up to day 56. Quantitative gene expression of interleukin-1beta (IL-1beta) in synovial tissue was measured on days 7 and 28. Eight rabbits were used for the measurement of MTX concentration in synovial tissue 12 hours after treatment. To evaluate the effect of microbubble-enhanced US treatment in the absence of MTX, only the microbubble agent was injected into the left and right knee joints of 10 rabbits with or without US exposure, and these animals were evaluated histologically on days 7 and 28.

RESULTS

The MTX concentration in synovial tissue was significantly higher in the MTX+/US+ group than in the MTX+/US- group. Synovial inflammation was less prominent in the MTX+/US+ group compared with the MTX+/US- group, judging from the results of the histologic evaluation and the gene expression levels of IL-1beta in synovial tissue. It also appeared that microbubble-enhanced US exposure itself did not affect inflammation.

CONCLUSION

Microbubble-enhanced US exposure promoted the uptake of MTX into synovial cells, which resulted in enhancement of the antiinflammatory effects of the intraarticular MTX injection. These results suggest that application of this technique may have clinical benefit.

Our first clinical experience with radiosynoviorthesis by means of (166)Ho-holmium-boro-macroaggregates

BACKGROUND

In this paper, we evaluate the therapeutic and adverse effects of the application of 166-holmium-boro-macroaggregates (HMBA) in radiosynovectomy (RSO) of the knees. We assessed the efficacy and safety of (166)Ho-HBMA in a prospective clinical trial in patients suffering from chronic synovitis.

MATERIAL AND METHODS

An effective component of radiopharmaceutical (166)Ho-boro-macroaggregates is radionuclide (166)Ho which has both beta-emission and gamma-emission. The physical half-life time of 166 Ho is 26.8 hours. After application of the radiopharmaceutical into a joint cavity, the effect of beta-emission causes radiation necrosis of pathologically changed (inflamed) synovial membrane. From 15th April 2005, we have started RSO of knees by means of new radiopharmaceutical (166)Ho-boro-macroaggregates in patients with gonarthrosis, rheumatoid arthritis, chronic synovitis, psoriatic arthritis, gout arthropathy. Seventeen intra-articular injections were performed in fifteen patients receiving a mean activity of 972 MBq (range: 904-1,057 MBq) (166)Ho-HMBA. The patients were hospitalized for three days. Side effects were evaluated during hospital stay and after 6-8 weeks. Static scintigraphy of knee joints and measurements of blood radioactivity were performed. Therapeutic effects were evaluated after 6-8 weeks.

RESULTS

In 2 hours and 2 days after application, we proved, by means of knee and inguinal scintigraphy, only insignificant radiopharmaceutical leakage from the joint cavity to the inguinal lymph nodes in four patients. In treated patients, no serious adverse effects occurred. Nine patients were without complaints; 4 patients had slight knee exsudation and 2 patients had great exsudation. Therapeutic effects after 6-8 weeks were as follows: 2 patients were without pain, 9 with lower pain, 3 with the same pain and 1 patient with increased pain. Joint motion was improved in 7 patients, remained the same in 7 patients and was impaired in 1 patient. Analgesics consumption was lower in 5 patients, the same in 9 patients and greater in 1 patient. Knee exsudation was absent in 2 patients, lower in 4 patients, the same in 6 patients and greater in 3 patients.

CONCLUSIONS

We proved only insignificant radiopharmaceutical leakage from the joint cavity to the inguinal lymph nodes. Six patients had early slight or great radiation synovitis. The possible cause could be rather high applicated activity. One can take into consideration its reduction. Therapeutic effects can be precisely evaluated after a longer time interval than was possible for us (6-8 weeks after RSO). (166)Ho-boro-macroaggregates can extend the scale of clinically used radiopharmaceuticals for RSO. This paper is presented in the scope of the first stage of clinical evaluation of synovectomy application of holmium-boro-macroaggregates.

Cutaneous radiation necrosis as a complication of yttrium-90 synovectomy

Radiation synovectomy is an effective method of treatment of chronic synovitis in patients with conditions such as rheumatoid arthritis, haemophilic synovitis and pigmented villonodular synovitis. This case demonstrates one of the potential complications of this procedure in a 46 year old man treated with bilateral radiation synovectomy for haemophilic synovitis. Cutaneous radiation necrosis is a known but rare complication of this procedure and this case is reported to demonstrate this known complication and to highlight that appropriate technique is required to avoid this.

Is corticosteroid coinjection necessary for radiosynoviorthesis of patients with hemophilia?

PURPOSE

Radiation synovectomy is frequently combined with intraarticular corticosteroid injection in the treatment of rheumatoid arthritis to reduce local inflammation and lymphatic clearance of radiocolloid. However, this practice is not universally accepted because corticosteroids have local and systemic toxicity such as osteonecrosis and cartilage damage and whether simultaneous corticosteroid injection together with radiocolloids is necessary in other forms of chronic synovitis like patients with hemophilia remains to be determined.

MATERIALS AND METHODS

In this study, we performed radiosynoviorthesis in 14 joints of 12 patients with hemophilia with chronic knee synovitis without corticosteroid coadministration and measured radiocolloid leakage from the joint space. Five mCi Y-90 radiocolloid was injected under local anesthesia and the needle was flushed with additional lidocaine injection instead of corticosteroid. The joint was then manipulated through a full range of extension and flexion to distribute the particles homogeneously throughout the joint space. The joint was then splinted for 48 hours to minimize leakage from the joint space. After the immobilization period, radiocolloid leakage was evaluated using a gamma camera with a 20% window centered over the maximum Bremsstrahlung photopeak of Y-90. Regions of interest were drawn to the injection site on the knee joint and to the ipsilateral inguinal lymph node area. Leakage of radiocolloid was calculated by dividing the background-corrected counts/pixel at the inguinal region by the counts/pixel at the injection site.

RESULTS

One of 12 patients who had knee arthroplasty was previously found to have a high amount of leakage. In this patient, 70% of radiocolloid at the injection site drained into the pelvic lymph nodes. In the remaining 11 patients, no lymph nodes were visualized in the groin area and the measured average leakage for these patients was 2.3% (range, 0-13).

CONCLUSION

We concluded that in cases of appropriate particle size and strict immobilization of knee joints, leakage of radiocolloid was minimal and steroid coinjection might not be necessary for radiosynoviorthesis of patients with hemophilia with chronic knee synovitis.

Sutureless avascular meniscal repair with a photoactive naphthalimide compound: a preliminary animal study

PURPOSE

The purpose of this study was to evaluate the ability of 2 new photoactive naphthalimide compounds to repair a lesion in the avascular zone of the meniscus.

TYPE OF STUDY

In vivo animal study.

METHODS

Ten Barbados sheep were used as the animal model. Under anesthesia, the left knee joint was opened and 2 identical lesions were produced in the avascular zone of the medial meniscus. The posterior horn lesion was left alone and used as the control and the lesion in the anterior horn was repaired using the photoactive laser technique. The photoactive laser technique involved placing small amounts of a naphthalimide compound into the lesion and then irradiating the site with a laser (457 nm and 1.8 W/cm2) for 6 minutes. Two different versions of the naphthalimide compound were produced and divided between the 10 animals. The joint was then flushed with normal saline and closed in layers with resorbable sutures. Four animals were euthanized at the end of 1 month and 6 animals were euthanized at the end of 3 months. After death, the medial meniscus was exposed, dissected free, and then placed in 10% buffered formalin for histologic preparation and staining.

RESULTS

At 1 month, the control lesions grossly showed no repair and the photochemically repaired lesions appeared to be bonded. The photochemically repaired lesions showed some bridging by an eosinophilic amorphous-appearing substance. The previous cleft within the fibrocartilaginous structure had disappeared, and early formation of connective tissue fibers was identified. However, some reduction in cellularity was seen in these tissue sections. At 3 months, again the control lesions did not show any repair response, while the photochemically repaired lesions showed results similar to the animals at 1 month, but with a less consistent pattern of tissue bonding and remodeling. The reduced tissue cellularity was still noted. There was no discernible difference between the naphthalimide compounds.

CONCLUSIONS

These preliminary results demonstrate the potential usefulness of this photochemical bonding for the treatment of avascular meniscal lesions. Additional research will be necessary to fully understand the mechanism of this repair and optimize its use before any human trials.

CLINICAL RELEVANCE

This is a preliminary animal study investigating the short-term in vivo effects of a novel photochemical compound for the repair of meniscal lesions. This repair may someday be valuable in the repair of avascular meniscal lesions.

Characterization of the ideal candidate for knee radiosynoviorthesis treatment in patients with rheumatoid arthritis

OBJECTIVES

(1). To identify the main parameters that positively influence the outcome of knee radiosynoviorthesis (RSO) in patients with rheumatoid arthritis (RA) and (2). to determine the ideal candidate for this procedure.

METHODS

We considered 80 knees (in 57 patients) that had undergone follow-up for at least 5 years and/or prosthesis implantation after RSO treatment. The parameters evaluated included age, gender, oligo-articular or polyarticular involvement, disease progression, radiological joint damage (Larsen scale), instability and/or axial deviation, body mass index (BMI), and psychological motivation for prosthesis implantation.

RESULTS

Knee Larsen stage IV, presence of instability-axial deviation, disease progression, psychological motivation to the surgical replacement and BMI higher than the 85th percentile were associated with a negative outcome for RSO (prosthesis implantation).

CONCLUSIONS

The ideal candidate for the RSO treatment is a patient with a low Larsen stage, no instability and/or axial deviation and a BMI below the 85th percentile. A patient's psychological motivation for the treatment should be evaluated before the RSO procedure.

The effects of therapeutic vs. high-intensity ultrasound on the rabbit growth plate

Six of 6-week-old NZ rabbits underwent ultrasound treatment using a therapeutic dose (0.5 W/cm(2)) and other six were treated with a higher dose (2.2 W/cm(2)) to the lateral aspect of the left knee joint for 20 min per day and a total of six weeks. The right knee joint served as a control. The goal of this study is to see if the therapeutic dose and high dose (approximately 45-fold therapeutic dose) will have toxic effects on the physis. Histological review appeared normal growth plate in the therapeutic group. In the high dosage group three of six cases displayed flattening of the distal femoral epiphysis and wedging of the proximal tibial plateau and indistinct growth plate lines. It is of interest to note that there are opening radiolucent area in the lateral aspect on the femoral metaphysis in five of six cases, where bone resorption has taken place. Histological results showed that there are disordered arrays of the cartilaginous cells in the proliferative zone. The height of the lateral physis in the high dose group is not only greater than that in the therapeutic dose (1083.8 vs. 500.3 micro m), but also greater than that in their contralateral control (530.7 micro m) (P<0.05). This short-term study demonstrates that high dose ultrasound has profound pathologic effects in growing bone. Therapeutic doses of ultrasound do not have an adverse effect on bone growth in the short-term follow-up.

188Re-tin-colloid as a new therapeutic agent for rheumatoid arthritis

Radiation synovectomy is a useful treatment modality in patients with refractory synovitis. We have developed a 188Re-tin-colloid as a new radiopharmaceutical agent and investigated its efficacy and safety in patients with rheumatoid arthritis. Radiation synovectomy was performed using 188Re-tin-colloid in 22 knees from 21 rheumatoid arthritis patients refractory to intra-articular corticosteroid injection. The efficacy and safety of administration of 370-1110 MBq of 188Re-tin-colloid were evaluated after 1, 3, 6, 9 and 12 months. Pain intensity on a visual analogue scale decreased significantly 12 months after therapy (mean+/-SD: 68.0+/-26.1 mm vs. 25.1+/-23.4 mm; P=0.0001 by the paired t-test). Pain decreased in 19 cases (86.3%), joint tenderness improved in 14 cases (63.6%) and joint swelling was reduced in all cases (100%). 188Re-tin-colloid was safe. The residual activity of 188Re in the blood was 0.077%+/-0.25% of the injected dose. The radioactivity of 188Re in the urine was 0.14%+/-0.13% of the injected dose. Transient reactive synovitis was observed in 18 cases (81.8%). No clinical side-effects or abnormalities in leucocyte count, platelet count, liver function tests or urine analysis were observed in any patient. In conclusion, in this first study of radiation synovectomy using 188Re-tin-colloid for patients with rheumatoid arthritis, the treatment resulted in the improvement of arthritis and was well tolerated.

Comparison of Tc-99m HIG and three-phase Tc-99m MDP bone scintigraphy for evaluating the efficacy of Yttrium-90 silicate radionuclide synovectomy

PURPOSE

The aim of this study was to compare Tc-99m human immunoglobulin (HIG) and three-phase Tc-99m MDP bone scintigraphy for the assessment of the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.

MATERIALS AND METHODS

Fifteen patients with rheumatoid arthritis and chronic persistent synovitis in 23 knee joints had radionuclide synovectomy with Y-90 silicate. The patients underwent imaging before and 3, 6, 9, and 12 months after therapy using clinical evaluation, Tc-99m HIG scintigraphy, and three-phase Tc-99m MDP bone scintigraphy.

RESULTS

In the 13 of 23 knee joints that showed successful clinical results with Y-90 therapy, the Tc-99m HIG index values obtained 3 months after radionuclide synovectomy were significantly lower than the pretreatment index values (P < 0.001). In the same 13 joints, the Tc-99m MDP index values (in the blood-pool and delayed phases) before and 3 months after therapy were statistically similar. Six months after injection, these values were significantly lower in both the blood-pool (P < 0.001) and late (P < 0.05) phases in all 13 joints. In the other 10 of 23 knee joints that did not respond to treatment, the Tc-99m MDP and Tc-99m HIG index values were statistically similar before and after Y-90 therapy.

CONCLUSIONS

Based on these findings, Tc-99m HIG scintigraphy appears to be a valuable method that complements clinical assessment of the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis, starting in the early post-treatment period. However, three-phase Tc-99m MDP bone scintigraphy may be valuable in the late postsynovectomy period.

Does yttrium radiosynovectomy increase the risk of cancer in patients with rheumatoid arthritis?

OBJECTIVE

To study the long term risk of cancer in patients with rheumatoid arthritis (RA) who have been treated with yttrium.

METHODS

The medical record numbers of 1228 patients with RA who were admitted to hospital in 1979-85 were identified in the database of Jyväskylä Central Hospital. Radiosynovectomy of the knee joint was performed in a total of 143 patients using yttrium-90 silicate during the years 1970-85, while 1075 did not receive yttrium radiosynovectomy; 10 received yttrium treatment later than 1985 and were excluded from the analysis. The Finnish Cancer Registry database was used to examine whether the subjects had cancer during the follow up from 1979 until the end of 1999.

RESULTS

Nine cases of cancer were found among the patients who had received yttrium, whereas the expected number based on the incidence among the population in the region was 14.9. The standardised incidence ratio of cancer was 0.6 (95% confidence interval (CI) 0.3 to 1.1) for the patients who received yttrium, and 1.1 (95% CI 0.9 to 1.3) for the patients who did not receive yttrium.

CONCLUSIONS

Yttrium treatment did not increase the risk of cancer.

Monopolar thermal treatment of symptomatic anterior cruciate ligament instability

Patients with anterior cruciate ligament instability resulting from incomplete tears or elongation in continuity without ligament detachment historically have been treated conservatively or by graft replacement. The literature is sparse regarding alternative treatments. The current study presents experience using monopolar thermal repair on 28 consecutive knees with partial anterior cruciate ligament tears all symptomatically unstable. All lesions were less than 6 months old (average, 77 days; range, 7-180 days) and with a difference of 6 mm or more (average, 9 mm; range, 6-13 mm) when comparing both knees using KT-1000 evaluation. Incomplete tears of the anterior cruciate ligament were seen at arthroscopic evaluation. The rehabilitation protocol included use of a brace for at least 6 weeks and progressive weightbearing. A 2-year minimum followup (range, 24-35 months) was done in all patients following the International Knee Documentation Committee guidelines. The overall outcome was normal or nearly normal in 96% of the patients. One failure occurred at 8 weeks. Twenty-six knees had a KT-1000 difference between 0 and 2 mm (average, 1.9 mm). Because thermal application causes death to some of the cells directly treated, it should be taken into account in selection and application. Immediately after thermal use, the anterior cruciate ligament, although thicker and tighter, is at first weaker than normal. Rehabilitation and compliance are critical during early ligament healing. This procedure seems to be a reasonable alternative to anterior cruciate ligament grafting in selected patients.

Preparation of 153Sm-chitosan complex for radiation synovectomy

A samarium 153-chitosan complex was prepared by simply mixing acidic solutions of chitosan and (153)SmCl(3). When a solution of this complex was injected into the knee joints of rabbits, minimal extra-articular leakage was observed. This can be attributed to the rapid change in the pH of the complex solution from acidic to neutral, resulting in the formation of gel followed by the subsequent retention in the administered site. Thus, the complex solution represents a promising candidate for radiation synovectomy.

Histologic study of effects of radiation synovectomy with Rhenium-188 microsphere

Rhenium-188 microsphere is a relatively new radiation synovectomy agent developed for the treatment of rheumatoid arthritis. It has been shown that the levels of unwanted extra-articular radiation are negligible with this agent. A histologic study was conducted to assess the effect of radiation synovectomy on synovium and articular cartilage after intra-articular injection of various doses of Re-188 microspheres into the knee joints of rabbits. Intra-articular injection of Re-188 microspheres into rabbit knee joints resulted in mild reactive inflammation and thrombotic occlusion of vessels which subsided rapidly. Sclerosis of subsynovium could be seen 12 weeks after injection. No evidence of damage to articular cartilage was noted. There was no significant difference in the articular pattern after injection of 0.3 or 0.6 mCi Re-188 microspheres. This study suggests that a treatment dose of Re-188 microspheres causes transient inflammation of synovium without any detectable damage to the articular cartilage of knee joint.

Calculation of electric fields induced in the human knee by a coil applicator

Calculations are presented of the induced electric fields and current densities in the cartilage of the knee produced by a coil applicator developed for applying pulsed magnetic fields to osteoarthritic knees. This applicator produces a sawtooth-like magnetic field waveform composed of a series of 260-micros pulses with a peak to peak magnitude of approximately 0.12 mT in the cartilage region. The simulations were performed using a recently developed 3 dimensional finite difference frequency domain technique for solving Maxwell's equations with an equivalent circuit model. The tissue model was obtained from the anatomically segmented human body model of Gandhi. The temporal peak electric field magnitude was found to be -153 mV/m, averaged within the medial cartilage of the knee for the typical dB/dt excitation levels of this coil. The technique can be extended to analyze other excitation waveforms and applicator designs.

Radiation prophylaxis for heterotopic ossification of the knee

Heterotopic ossification (HO) occurs in 42% of patients who have undergone total knee arthroplasty. Bone formation usually is found in the quadriceps expansion and causes minimal to no symptoms. Specific therapy usually is unnecessary, but cases have been reported in which manipulation under anesthesia or revision arthroplasty has been required. We report a small series of 5 patients (6 knees) who have undergone surgical intervention for HO of the knee with radiotherapy given postoperatively for prophylaxis against future HO. Although this series is small, it appears that the use of prophylactic radiation may reduce recurrence after resection of symptomatic HO after total knee arthroplasty. Further investigation is required to confirm these preliminary findings.

Salvage of the exposed irradiated knee joint with free tissue transfer

Extremity radiation results in substantial complications in 6% to 10% of patients and includes fracture, edema, pain, fibrosis, neuropathy, arterial thrombosis, joint immobility, soft-tissue necrosis, and chronic infection. Chronic ulceration and infection of an irradiated joint is considered a particularly challenging problem for the reconstructive surgeon, and results of surgical management of these complications have not been reported previously in the medical literature. Two patients are presented with large ulcerated and necrotic radiation wounds of the knee, with chronic contamination, osteomyelitis, and involvement of the joint space. Both patients were treated successfully with debridement and coverage with free tissue transfer. They obtained stable, healed wounds, became pain free, and were able to ambulate on long-term follow-up. Adherence to principles established previously for the management of radiation-induced ulcers on other parts of the body not involving joint spaces (namely, thorough wound debridement and coverage with nonirradiated, well-vascularized tissue) can allow successful extremity salvage even in the presence of joint exposure, contamination, and osteomyelitis.

Radiation synovectomy using 165Dy ferric-hydroxide and oxidative DNA damage in patients with different types of arthritis

Radiation synovectomy is an effective treatment for chronic synovitis refractory to pharmacological treatment in patients with rheumatoid or seronegative arthritis. Concerns persist about possible radiation-induced cytogenetic damage after radiation synovectomy leading to recommendations to use this technique only in the elderly. Micronucleus (MN) frequency in lymphocytes and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8OHdG) as an indicator of cellular oxidative DNA base damage are biomarkers of radiation-induced cytogenetic damage. The course of both biomarkers was studied in patients with different types of chronic synovitis undergoing radiation synovectomy with very short-lived 165Dy-ferric-hydroxide (DFH).

METHODS

Radiation synovectomy of the knee was performed in 13 men and 12 women (mean age, 44+/-15 y) using a mean activity of 9.48+/-1.65 GBq 165Dy-DFH in 27 consecutive treatments. MN frequency in lymphocytes and urinary excretion of 8OHdG, measured by high-performance liquid chromatography, were assessed before and 4 (MN only) and 20 h after radiation synovectomy.

RESULTS

Urinary excretion of 8OHdG in patients (in micromol/mol creatinine; pretreatment mean, 3.1+/-3.4; median, 2.27) was not significantly different from that in healthy volunteers (mean, 2.0+/-1.2; median, 1.87) and not altered by radiation synovectomy (post-treatment mean, 2.5+/-1.5; median, 2.04, NS). An increase in 8OHdG levels after radiation synovectomy of more than 1 SD was found in only 1 patient, who experienced leakage to the lymph nodes but who already had elevated urinary 8OHdG levels before treatment. The frequency of MN/500 binucleated cells (BNCs) was slightly lower in patients (pretreatment mean, 4.3+/-2.6; median, 4.25) than in healthy volunteers (mean, 5.4+/-2.3; median, 5.3) and did not significantly change after therapy, either (4-h post-treatment mean, 3.9+/-2.1, median, 3.8; 20-h post-treatment mean, 4.1+/-2, median 3.8 MN/500 BNC). In 22 of 27 treatments, no leakage to nontarget organs could be monitored, whereas leakage to the local lymph nodes and the liver was detected after 5 treatments.

CONCLUSION

Radiation synovectomy using 165Dy-DFH causes no significant radiation burden to most patients as indicated by the absence of adverse changes in levels of biomarkers of cytogenetic damage and a low incidence of leakage. These data suggest that the risk of malignancy may not be elevated.

[Activity leakage and radiation exposure in radiation synovectomy of the knee: influence of different therapeutic modalities]

In rheumatic diseases, radiation synovectomy is a reliable method. Meanwhile, radiation synovectomy is an outpatient therapy. In addition, combination with arthroscopic synovectomy is an increasing therapeutic modality. In comparison to the hitherto inpatient modality, a greater lymphatic emigration of the radionuclide and, therefore, a higher radiation exposure is possible. In 35 patients we found radionuclide emigration in 17 cases by whole body scintigraphy, resulting in a 50%-percentile with 68.27%-confidence interval of 1.8 (0.45-4.78)% of the injected yttrium-90-activity. Comparison of 3 groups with the above mentioned therapy modalities resulted in no statistical difference (p>0.05). Because of the found radionuclide emigration, a radiation dose of 0. 1 (0.05-0,18) mSv in women and 0.2 (0.1-0.38) mSv in men was calculated. For lymph nodes, liver, spleen and whole body radiation doses of 619 (154-1644) mSv, 62 (15-165) mSv, 62 (15-165) mSv and 37 (9-99) mSv were calculated. Gonadal radiation dose can be neglected and the morbidity rate for tumors because of the whole body radiation dose is low with a value of 0.4 per thousand. Therefore, radiation synovectomy can be used unlimited by patients age and independent of the therapeutic modality.

[The effects of low-dose Co-60 irradiation on the course of aseptic arthritis in a rabbit knee joint]

PURPOSE

Numerous clinical observations demonstrate the efficacy of low radiation doses in the treatment of painful osteoarthritis. Experimental investigations remain scarce. We investigated the effects of locally daily 5 times 1.0 Gy 60-Co irradiation on an artificially induced aseptic gonarthritis in rabbits.

MATERIAL AND METHODS

Three separate experiments (EV) were performed (10 rabbits per experiment, 5 treated/5 controls; duration: EV1: 18 days; EV2: 6 days; EV3: 29 days). An aseptic arthritis in the right knee joint of rabbits was induced by intraarticular injection of 0.5 ml papain solution (3%, 30,000 USP/mg) on day 0. The arthritic knee joint of the anesthesized animals was irradiated daily from day 1 to 5 with 5 times 1.0 Gy. The controls were sham-irradiated under the same conditions. The time course of arthritis in treated animals and sham-treated controls was evaluated by clinical, laboratory-chemical and histological criteria. The clinical investigation was performed daily, the puncture of the knee-joints was carried out several times in EV1, and at the end of experiments in EV2 and EV3. At the end of the observation period, animals were killed and the knee joints excised for histological analysis.

RESULTS

The intraarticular injection of papain caused a peracute inflammatory response in all animals. After 1 week the chronic stage was reached, and the experimental arthritis resolved slowly within several weeks. Local irradiation accelerated the decrease of inflammatory joint swelling, being significant by day 4. On day 6 the volume of synovial fluid in irradiated knee-joints was significantly smaller. The morphometric data indicated a reduction in thickness of synovial membrane, a decrease in number of synovial cell layers, and a decrease in distance between capillaries and the synovial membrane surface following irradiation of arthritic joints. Due to considerable individual variability, the morphometric data partially did not reach statistically significance.

CONCLUSION

The experiments provide evidence for an antiphlogistic effect of irradiation with 5 times 1.0 Gy in vivo. They support the clinical observations of the efficacy of anti-inflammatory radiotherapy.

The effect of radiofrequency energy on the ultrastructure of joint capsular collagen

This study evaluated the effect of radiofrequency energy on the histological and ultrastructural appearance of joint capsular collagen. Femoropatellar joint capsular specimens from adult sheep were treated with one of three treatment temperatures (45 degrees C, 65 degrees C, and 85 degrees C) with a radiofrequency generator or served as control in a randomized block design. Twenty-four specimens (n = 6) were processed for histological examination as well as ultrastructural analysis using transmission electron microscopy. A computer-based area determination program was used to calculate the area affected in histological samples. Histological changes consisted of thermal tissue damage characterized by collagen fiber fusion and fibroblastic nuclear pyknosis at all application temperatures with clear demarcations between treated and untreated tissue. Mean tissue affected ranged from 50.4% for 85 degrees C to 22.5% for 45 degrees C. There was a strong correlation between treatment temperature and percent area affected (P < .001, R2 = .65). Ultrastructural alterations included a general increase in cross-sectional fibril diameter and loss of fibril size variation with increasing treatment temperature. Longitudinal sections of collagen fibrils showed increased fibril diameter and the loss of cross-striations in the treated groups. Thermally induced ultrastructural collagen fibril alteration is likely the predominant mechanism of tissue shrinkage caused by application of radiofrequency energy.

Radiochemical synovectomy

Radiochemical synovectomies have been used for nearly fifty years for the treatment of persistent monoarticular synovitis refractory to antiinflammatory drugs, disease modifying drugs, and intraarticular corticosteroids. It is a therapeutic alternative to surgical synovectomy. There are controversies concerning safety, choice of appropriate agent, and logistics of administration. These concerns are discussed in addition to reviewing some of the more recent trials examining the efficacy of radiochemical synovectomy. It is clear that in properly selected patients this procedure is safe and beneficial.

Monitoring of the biodistribution and biokinetics of dysprosium-165 ferric hydroxide with a shadow-shield whole-body counter

Radiation synovectomy is indicated when conventional pharmacological treatment of chronic synovitis has proved insufficient. In these cases dysprosium-165 ferric hydroxide (DFH) has been demonstrated to be clinically effective. After application of the agent, blood activity measurements and monitoring of activity distribution by gamma camera imaging over the local lymph nodes and the liver are commonly performed for control of possible leakage. In addition, we have used a shadow-shield whole-body counter with a profile facility to evaluate the biokinetics and biodistribution of 165Dy-DFH. Fifteen intra-articular injections were performed in 13 patients who received a median activity of 6.8 GBq (range 0.5-9.9 GBq) 165Dy-DFH. Activity profiles were obtained with the whole-body counter 2, 4 and 6 h after injection of 165Dy-DFH. The doses to non-target organs were calculated using the software MIRDOSE 3. In 10 of 15 treatments, absence of any leakage could be demonstrated. The effect of scattered rays could be observed in 14 measurements. In three patients small amounts of activity could be detected in the urinary bladder and in three patients activity was detected in the local inguinal lymph nodes, while no leakage could be detected by camera imaging. In these cases the individual doses to the bladder were 15 Gy, 65 mGy and 50 mGy, and those to the lymph nodes, 0.54 Gy, 0.89 Gy and 2.41 Gy. The whole-body counter also enabled the monitoring of activity profiles related to more complex pathological structures. In conclusion, using a whole-body counter activity leakage could be detected with much higher sensitivity than by using a gamma camera. The biodistribution of 165Dy-DFH could be determined, and leakage could be localised and related to organs. These results encourage the use of a whole-body counter to identify the site and extent of activity leakage.

[Arthroscopic synovectomy and radiosynoviorthesis]

Both procedures, radiosynoviorthesis and arthroscopic synovectomy, are well established in the local treatment of rheumatically deformed joints. By combining the two minimal invasive procedures one can increase the radicality and still decrease traumatization. A prospective study by Herresthal indicates the superiority of the combined therapy over the single nuclide therapy of knee joints in rheumatoid arthritis. This is due to the lesser traumatization as compared to the open synovectomy and to the possibility to remove fibrinous plaques which may impair the efficiency of radiosynoviorthesis. Histology, method and the respective indications regarding the joints of the upper and lower limbs are discussed.

Comparison of the efficacy of nonsurgical synovectomy (synoviorthesis) and joint lavage in knee osteoarthritis with effusions

OBJECTIVE

Radioactive or chemical synovectomy (synoviorthesis) is widely used as local therapy for inflammatory joint disease in France. The objective of this retrospective study was to compare the efficacy of osmic acid or radiation synovectomy with that of joint lavage for the treatment of knee osteoarthritis with effusions.

PATIENTS AND METHODS

All study patients met American College of Rheumatology criteria for knee osteoarthritis, which was symptomatic despite conservative therapy including local corticosteroid injections. Fifty-four patients were treated by synoviorthesis (osmic acid, n = 16; yttrium 90, n = 76) and 45 by joint lavage (total 67 lavages).

RESULTS

Thirty two per cent of the patients in the synoviorthesis group had a good or excellent outcome after six months. Results were better with yttrium 90 than with osmic acid. Improvements were most marked in patients with chondrocalcinosis. Efficacy was negatively correlated with the femorotibial lesions but not with the patellofemoral lesions. Patients with knee alignment disorders had poorer outcomes. In the joint lavage group, 30% of the knees showed improvements after three months and results were significantly better after three and six months when the lavage was followed by an injection of triamcinolone hexacetonide. No side effects were recorded.

CONCLUSION

Our data suggest that chemical or radiation synovectomy or joint lavage followed by injection of a delayed-action steroid may be useful for the treatment of knee osteoarthritis with chronic or recurrent effusions.

Treatment of antigen-induced arthritis in rabbits by the intra-articular injection of methylprednisolone, 90Y or chlorambucil

Rabbits with a bilateral antigen-induced arthritis were injected intra-articularly (i.a.) in one joint with methylprednisolone (1 mg), 90Y (18.5 MBq) or chlorambucil (1 mg) as a single dose. The severity of arthritis was determined by measuring joint swelling and skin surface temperature, macroscopic and histological changes in the joint being assessed 8 weeks after induction of arthritis when the rabbits were killed. Methylprednisolone injected at the time of antigen challenge or 3 weeks later caused a reduction in joint swelling and temperature (P < 0.05) for 1 to 6 weeks after injection. 90Y had an initial proinflammatory effect lasting several days, but later caused a modest reduction in joint swelling for up to 4 weeks (P < 0.05). Eight weeks after induction of arthritis, neither methylprednisolone nor 90Y-treated joints showed any significant reduction in erosion or histopathology compared with control arthritic joints. Chlorambucil injected 1 week after antigen challenge caused a rapid reduction in joint swelling which was maintained for the duration of the study. Joint surface temperature was reduced to a lesser extent. Eight weeks after induction of arthritis, chlorambucil-treated joints showed a decrease (P < 0.05) in all of the parameters of disease pathology assessed. Treatment with chlorambucil intra-articularly was clearly more effective than with methylprednisolone or 90Y at the doses employed and deserves further study as a potential treatment for chronic synovitis.

Long-lasting tolerance of articular cartilage after experimental intraoperative radiation in rabbits

In experimental intraoperative irradiation, 18 adult rabbits received a single, 50-Gy dose of x-radiation at a unilateral knee joint, and subsequent changes in the articular cartilage were examined over a 15-month period by histology, scanning electron microscopy, and autoradiography. Although the subchondral bone showed histologically typical findings of osteonecrosis three to nine months postirradiation, the articular cartilage revealed no obvious degenerative changes during the entire study period. Scanning electron microscopy revealed normal collagen architecture in the irradiated cartilage for as long as 15 months postirradiation. Autoradiography demonstrated active RNA synthesis by the irradiated chondrocytes during the same period. These results indicate that articular cartilage tissue tolerates intraoperative radiotherapy without sustaining serious degenerative changes, unless possible collapse or contracture disturbs its biomechanical integrity. The survival of articular cartilage can be advantageous for this type of limb-salvage surgery in the treatment of malignant bone tumors around a synovial joint.

Interleukin 2 (IL 2) inhibitor in rheumatoid synovial fluid: correlation with prognosis and soluble IL 2 receptor levels

A soluble activity inhibiting over 50% of the CTLL-2 cell line response to recombinant human interleukin 2 (IL 2) was found in 17 of 29 (59%) rheumatoid synovial fluids. To study the prognosis value of this activity, 16 rheumatoid synovial fluids were collected before a radiation synovectomy of the knee with 7 mCi of 90Yt. Patients with a good clinical result after the synovectomy had a lower IL 2 inhibitory activity than those with a bad or incomplete result (P less than 0.01). Levels of inhibitory activity and of soluble IL 2 receptors were correlated with each other and with the response of the synovitis to the radiation synovectomy. These results extend the clinical usefulness of soluble IL 2 receptor measurements and indicate a correlation between the immune activation of the rheumatoid synovitis and its clinical activity.

[Effect of local laser irradiation on the morphological and ultrastructural changes in the joint tissues in experimental arthritis]

The authors studied the results of the effect of local laser irradiation on the tissues of joints in experimental arthritis induced in rabbits. Laser irradiation suppressed the immunopathological process in the synovial membrane of joints and enhanced destruction of cartilage.