Localized pigmented villo-nodular synovitis of trochanteric bursa.

This is the first report on a localized pigmented villo-nodular synovitis (PVNS or TSGCT) occurring in the trochanteric bursa. Bursal involvement in PVNS is extremely rare. Most often PVNS occurs either as a localized or diffuse lesion in a major synovial joint, such as the knee, ankle joint or hip joint. In principle, all synovial structures can be involved. The case reported here is remarkable regarding the long period between the occurrence of the first symptoms and the final diagnosis as well as the age of the female patient (75 yrs). Therapeutically a complete resection was performed in order to avoid recurrence. More then three years later the patient did well and there has been no evidence of recurrence yet.

Osteochondral Lesions of the Talus: A Review on Talus Osteochondral Injuries, Including Osteochondritis Dissecans.

This is a review on talus osteochondritis dissecans and talus osteochondral lesions. A majority of the osteochondral lesions are associated with trauma while the cause of pure osteochondritis dissecans is still much discussed with a possible cause being repetitive microtraumas associated with vascular disturbances causing subchondral bone necrosis and disability. Symptomatic nondisplaced osteochondral lesions can often be treated conservatively in children and adolescents while such treatment is less successful in adults. Surgical treatment is indicated when there is an unstable cartilage fragment. There are a large number of different operative technique options with no number one technique to be recommended. Most techniques have been presented in level II to IV studies with a low number of patients with short follow ups and few randomized comparisons exist. The actual situation in treating osteochondral lesions in the ankle is presented and discussed.

Osteochondritis Dissecans of Smaller Joints: The Elbow.

This review presents the current understanding of the etiology, pathogenesis, and how to diagnose and treat osteochondritis dissecans (OCD) at the elbow joint followed by an analysis of particular characteristics and outcomes of the treatment. OCD is seen in patients with open growth plates (juvenile OCD [JOCD] and in adults [AOCD] with closed growth plates [adult OCD). The etiology at smaller joints remains as unclear as for the knee. Mechanical factors (throwing activities [capitulum] seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important for the diagnosis. In low-grade and stable lesions, treatment involves rest and different degrees of immobilization until healing. When surgery is necessary, the procedure depends on the OCD stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable while with damaged cartilage, several techniques are used. Techniques such as drilling and microfracturing produce a reparative cartilage while other techniques reconstruct the defect with osteochondral grafts or cell-based procedures such as chondrocyte implantation. There is a tendency toward better results when reconstructive procedures for both the bone and cartilage are used. In addition, comorbidities at the joint have to be treated. Severe grades of osteoarthritis are rare.

Efficient adjustable light couplers of integrated III-V nanowire emitters on silicon waveguides based on ring resonators.

The development of integrated vertical III-V nanowire (NW) stimulated emitters in silicon photonics while achieving an efficient light coupling through vertical III-V NW lasers into horizontal optical silicon waveguides is demanding. This is mainly due to the directionality and contradiction of the simultaneously satisfied low threshold stimulated emission conditions of the vertical NWs and efficient light coupling from the NW emitters into the horizontal silicon waveguide. However, we propose a new, to the best of our knowledge, design by taking advantage of resonating features of ring structures and theoretically demonstrate that an interfacial ring resonator between GaAs NW emitters and the silicon waveguide achieves a coupling efficiency up to about 70% at a given wavelength. We also show that the interfacial resonator enables us to adjust the coupling efficiency from about 10% to over 70%. The adjustable coupling efficiency might also be a solution to compromise between the low threshold stimulated emission of NWs and efficient light coupling for realizing efficient silicon couplers based on integrated III-V NW lasers in silicon photonics. Besides the simple fabrication process compared to counterparts, we believe that the novel structure is promising for future optical on-chip data communication in silicon photonics, and the results are expandable to varying wavelengths and materials.

Osteochondritis Dissecans: Etiology, Pathology, and Imaging with a Special Focus on the Knee Joint.

This article is a review of the current understanding of the etiology, pathogenesis, and how to diagnose and treat knee osteochondritis dissecans (OCD) followed by an analysis of and outcomes of the treatments available. OCD is seen in children and adolescents with open growth plates (juvenile OCD) and adults with closed growth plates (adult OCD). The etiology of OCD lesions remains unclear and is characterized by an aseptic necrosis in the subchondral bone area. Mechanical factors seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important. Regarding treatment, a tremendous number of publications exist. Spontaneous healing is expected unless there is an unstable fragment, and treatment involves rest and different degrees of immobilization until healing. Patients with open physes and low-grade lesions have good results with conservative therapy. When surgery is necessary, the procedure depends on the stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable. When the cartilage is damaged, several techniques can be used. While techniques such as drilling and microfracturing produce reparative cartilage, other techniques reconstruct the defect with additional osteochondral grafts or cell-based procedures such as chondrocyte transplantation. There is a tendency toward better results when using procedures that reconstruct the bone and the cartilage and there is also a trend toward better long-term results when comorbidities are treated. Severe grades of osteoarthrosis are rare.

Is vitamin D insufficiency or deficiency related to the development of osteochondritis dissecans?

PURPOSE: The aetiology of osteochondritis dissecans is still unclear. The aim of this prospective pilot study was to analyse whether vitamin D insufficiency, or deficiency, might be a contributing etiological factor in the development of an OCD lesion. METHODS: The serum level of vitamin D3 in 23 consecutive patients (12 male and 11 female) suffering from a stage III, or stages III and IV, OCD lesion (mostly stage III) admitted for surgery was measured. RESULTS: The patients' mean age was 31.3 years and most of them already exhibited closed epiphyseal plates. In the majority of patients (18/23), a distinct vitamin D3 deficiency was found, two patients were vitamin D3-insufficient and, in three patients, the vitamin D3 level reached the lowest normal value. CONCLUSION: These first data show that a vitamin D3 deficiency rather than an insufficiency may be involved in the development of OCD lesions. Probably, with a vitamin D3 substitution, the development of an advanced OCD stage could be avoided. Further analyses, including morphological analyses regarding a possible osteomalacia, and examination of the PTH and other determinants of the bone metabolism, should be undertaken to either confirm or refute these data. LEVEL OF EVIDENCE: IV.

Pigmented villo-nodular synovitis and giant-cell tumor of tendon sheaths: a binational retrospective study.

AIM: Pigmented villonodular synovitis is rare. Thus, we initiated a retrospective multi-center study regarding symptoms, location, type of disease, type of surgery, number of recurrences, use of adjuvant therapies and functional outcome. RESULTS: Ten centers contributed. Data from 173 patients were sampled. The disease was seen predominantly in joints, less frequently in tendon sheaths and bursae. Patients with articular lesions suffered mainly from the diffuse type. In tendon sheaths, the relation "diffuse versus nodular" was nearly 50 % each, in bursae most often the nodular type was found. Anatomically, mostly the knee was affected. Institutions with more than 20 patients had a lower rate of recurrence than those with less than 20 cases. Regarding the knee, there were less recurrences in joints treated with open synovectomy than in those treated arthroscopically. CONCLUSIONS: Since the rate of recurrence has been rather high, the use of adjuvant treatments (radiosynoviorthesis or radiotherapy) is recommended. In our study, the rate of their application was quite low. Patients who received an adjuvant therapy after primary surgery did not show any recurrence. In 14 % of patients in whom an adjuvant therapy had been used, after at least one recurrence, further recurrences were observed. Functional results were excellent in 84 % of patients. LEVEL OF EVIDENCE: Prognostic multi-center study, Level III.

Osteochondritis dissecans of the tarsal navicular bone: a case report.

Osteochondritis dissecans most often affects the convex articular surfaces of the knee, the elbow, and the ankle joints; other sites of manifestation are very rare. Here we report a case of osteochondritis dissecans of the talonavicular joint affecting the concave part of the tarsal navicular bone in a 22-year-old woman, which was successfully treated by surgery, leading to complete recovery. Early diagnosis and surgery in stages of undamaged cartilage may help to prevent disease progression and the development of disabling osteoarthritis in the physiologically heavily loaded talo-navicular joint.

Modulation of bovine chondrocyte metabolism by free periosteal grafts in vitro.

PURPOSE: Autologous chondrocyte transplantation (ACT) is an established method in cartilage repair. Although long-term results show durable repair of isolated cartilage defects, some problems still remain. Since hypertrophy of the transplanted periosteum is a common problem, alternatives for periosteum are in demand. Periosteal grafts have been reported to stimulate neochondrogenesis via paracrine effects. The objective of this study was to evaluate the modulation of chondrocyte metabolism by periosteal grafts in vitro. METHODS: Periosteal explants and articular chondrocytes obtained from slaughtered adult cattle were co-cultured in a newly established perfusion system. The experimental groups were: 1. monocultured chondrocytes; 2. chondrocytes cultured with synovial supernatants; 3. chondrocytes cultured with periosteal supernatants; 4. chondrocytes co-cultured with periosteal explants. RESULTS: Chondrocyte proliferation, evaluated by measuring total DNA content, was prolongated by periosteal and synovial explants. Immunocytochemical staining of collagen type II was stronger in monoculture than in co-culture. Protein biosynthetic activity estimated by [³H]-proline incorporation, as well as extracellular matrix deposition for collagen type II, were reduced by periosteal and synovial explants. Additionally, co-culturing led to a decrease in aggrecan synthesis and release. The inhibiting effects were significantly stronger when cellular chondrocyte-periosteal cross-talk was made possible via paracrine effects. CONCLUSIONS: The results of our study suggest a catabolic effect of periosteal explants on isolated chondrocytes in vitro. Further investigations are necessary whether periosteum in ACT is dispensable.

Treatment of osteochondritis dissecans of the femoral condyle with autologous bone grafts and matrix-supported autologous chondrocytes.

The objective of this study was to determine the clinical outcome of combined bone grafting and matrix-supported autologous chondrocyte transplantation in patients with osteochondritis dissecans of the knee. Between January 2003 and March 2005, 21 patients (mean age 29.33 years) with symptomatic osteochondritis dissecans (OCD) of the medial or lateral condyle (grade III or IV) of the knee underwent reconstruction of the joint surface by autologous bone grafts and matrix-supported autologous chondrocyte transplantation. Patients were followed up at three, six, 12 and 36 months to determine outcomes by clinical evaluation based on Lysholm score, IKDC and ICRS score. Clinical results showed a significant improvement of Lysholm-score and IKDC score. With respect to clinical assessment, 18 of 21 patients showed good or excellent results 36 months postoperatively. Our study suggests that treatment of OCD with autologous bone grafts and matrix-supported autologous chondrocytes is a possible alternative to osteochondral cylinder transfer or conventional ACT.

Longitudinal long-term results of surgical treatment in patients with osteochondritis dissecans of the femoral condyles.

In a longitudinal study, we performed a second follow-up examination on patients suffering from osteochondritis dissecans at the femoral condyles 10 years after a first follow-up, which had been performed 10 years after surgical treatment. Results (clinical score; radiological signs of OA) were analysed depending on the stage of the epiphyseal plate at the time of surgery, the used surgical procedure was divided into retrograde and anterograde procedures, and removal of loose bodies depending on the stage of the lesion. The analysis clearly exhibited that JOCD patients demonstrated better results than AOCD patients. The clinical score obtained after 10 years improved significantly with time, particularly for JOCD patients. Overall, when a retrograde procedure had been used in cases with an intact cartilage layer clinical results were better than those obtained in patients in whom an anterograde procedure with restoration of the joint surface or simple removal of the loose fragments had been performed. After a mean follow-up of 20 years the mean OA-stage was 0.27 in JOCD patients, whereas in AOCD patients a mean OA-stage of 1.55 was detected. Worst OA-changes were detected in patients in whom acrylic glue had been used for refixation of the loose bodies.

Differential enhancement of collagen crosslink excretion in cases of osteosarcoma and chondrosarcoma.

Hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) are markers of collagen absorption and LP is specific for collagen type I in bone. In the present study we evaluated the concentration of HP and LP in urine of patients with osteosarcoma ( n=20; age range 16-49 years) and chondrosarcoma ( n=15; age range 18-70 years). The values were compared with those obtained from 74 healthy controls (age range 16-83 years). The range and upper limit of normal values (HP(max) and LP(max)) were measured in our control group. High performance liquid chromatography (HPLC) was used to determine concentrations of HP and LP (nmol/mmol creatinine). The average urinary HP concentrations were significantly increased in patients with osteosarcoma ( p=0.001) and chondrosarcoma ( p<0.001), whereas HP remained within the normal range in approximately half of the patients. The average urinary LP concentrations were not increased in osteosarcoma and chondrosarcoma patients as compared with the control group. Further studies in a large group of patients are necessary to evaluate whether HP might be a valuable marker of prognosis, and if its urinary concentration can be correlated to tumour burden.