60 research outputs found
Osteochondral transplantation using autografts from the upper tibio-fibular joint for the treatment of knee cartilage lesions
Purpose Treatment of large cartilage lesions of the knee
in weight-bearing areas is still a controversy and challenging topic. Autologous osteochondral mosaicplasty has
proven to be a valid option for treatment but donor site
morbidity with most frequently used autografts remains a
source of concern. This study aims to assess clinical results
and safety profile of autologous osteochondral graft from
the upper tibio-fibular joint applied to reconstruct symptomatic osteochondral lesions of the knee.
Methods Thirty-one patients (22 men and 9 women) with
grade 4 cartilage lesions in the knee were operated by
mosaicplasty technique using autologous osteochondral
graft from the upper tibio-fibular joint, between 1998 and
2006. Clinical assessment included visual analog scale
(VAS) for pain and Lysholm score. All patients were
evaluated by MRI pre- and post-operatively regarding joint
congruency as good, fair (inferior to 1 mm incongruence),
and poor (incongruence higher than 1 mm registered in any
frame). Donor zone status was evaluated according to
specific protocol considering upper tibio-fibular joint
instability, pain, neurological complications, lateral collateral ligament insufficiency, or ankle complaints.
Results Mean age at surgery was 30.1 years (SD 12.2). In
respect to lesion sites, 22 were located in weight-bearing
area of medial femoral condyle, 7 in lateral femoral condyle, 1 in trochlea, and 1 in patella. Mean follow-up was
110.1 months (SD 23.2). Mean area of lesion was 3.3 cm
2
(SD 1.7), and a variable number of cylinders were used,
mean 2.5 (SD 1.3). Mean VAS score improved from 47.1
(SD 10.1) to 20.0 (SD 11.5); p = 0.00. Similarly, mean
Lysholm score increased from 45.7 (SD 4.5) to 85.3
(SD 7.0); p = 0.00. The level of patient satisfaction was
evaluated, and 28 patients declared to be satisfied/very
satisfied and would do surgery again, while 3 declared as
unsatisfied with the procedure and would not submit to
surgery again. These three patients had lower clinical scores
and kept complaints related to the original problem but
unrelated to donor zone. MRI score significantly improved
at 18–24 months comparing with pre-operative (p = 0.004).
No radiographic or clinical complications related to donor
zone with implication in activity were registered.
Conclusions This work corroborates that mosaicplasty
technique using autologous osteochondral graft from the
upper tibio-fibular joint is effective to treat osteochondral
defects in the knee joint. No relevant complications related
to donor zone were registered
Propagation of the blackbody radiation in a periodic metamaterial
Rectification of electromagnetic radiation in gapless materials is a subject of a great engineering interest. Its possible applications are the ultrafast detectors of IR and teraherz radiation, high-efficiency harvesting of the solar radiation and the waste heat, for instance from exothermal industrial processes. All these processes lie in the terahertz or IR region of frequencies. One of the principal limitations of using of rectennas for harvesting electromagnetic radiation is a limited coherence of most possible sources. The authors in their previous paper predicted an enhancement of coherence when a δ-correlated noise modeling blackbody radiation passes through a periodic grating at a distance comparable to Talbot distance LT = δT L2 where L is a period of the lattice and λT=c·h/kBT is a Wien length for the temperature T
Comment on the validity of first-order paraxial theory for electron and ion sources with needle-type or pointed geometry
Derivation of a modified paraxial formalism for two-dimensional trajectories in electron and ion sources of non-simple geometries
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