Protective effects of polydeoxyribonucleotides on cartilage degradation in experimental cultures.

The capacity of cartilage self-regeneration is considered to be limited. Joint injuries often evolve in the development of chronic wounds on the cartilage surface. Such lesions are associated with articular cartilage degeneration and osteoarthritis. Re-establishing a correct micro/macro-environment into damaged joints could stop or prevent the degenerative processes. This study investigated the effect of polydeoxyribonucleotides (PDRNs) on cartilage degradation in vitro and on cartilage extracted cells. The activities of matrix metalloproteinases 2 and 9 were measured in PDRN-treated cells and in controls at days 0 and 30 of culture. Human nasal cartilage explants were cultured, and the degree of proteoglycan degradation was assessed by measuring the amount of glycosaminoglycans released into the culture medium. The PDRN properties compared with controls were tested on cartilage tissues to evaluate deposition of extracellular matrix. Chondrocytes treated with PDRNs showed a physiological deposition of extracellular matrix (aggrecan and type II collagen: Western blot, IFA, fluorescence activated cell sorting, Alcian blue and safranin O staining). PDRNs were able to inhibit proteoglycan degradation in cartilage explants. The activities of matrix metalloproteinases 2 and 9 were reduced in all PDRN-treated samples. Our results indicate that PDRNs are suitable for a long-term cultivation of in vitro cartilage and have therapeutic effects on chondrocytes by protecting cartilage.

Segmental analysis of motor conduction velocity in distal tracts of tibial nerve: a coaxial needle electrode study.

OBJECTIVE: To describe a new method of segmental analysis of motor nerve conduction velocity (mCV) in the tibial nerve (Tn) tract distal to the upper margin of the tarsal tunnel (TT). METHODS: Compound muscle action potentials (CMAPs) were recorded with a coaxial needle electrode from the flexor hallucis brevis muscle (FHB), to test the medial plantar nerve (MPn), and from the flexor digiti quinti brevis (FDQB) and the first dorsal interosseous (FDI) muscles, to test the superficial and deep branches of the lateral plantar nerve (sLPn and dLPn, respectively). CMAPs were elicited by stimulating at three sites located above (S1) and below (S2) the TT and at the sole of the foot (S3 for MPn and S4 for LPn). RESULTS: In 20 normal subjects the mean mCV in the proximal (S1 to S2) tract was 44.5+/-4.7, 43.5+/-5.9 and 42.6+/-4.2m/s for the MPn, sLPn and dLPn, respectively. The corresponding values in the intermediate tract (S1 to S3/S4) were 40.7+/-5.6, 39.4+/-5.6 and 40.9+/-5.8m/s. CONCLUSIONS: Segmental analysis of mCV in distal Tn can be performed when CMAPs are recorded using a coaxial needle electrode, which prevents simultaneous recording of activity from nearby muscles groups. SIGNIFICANCE: Conventional neurophysiological examination for suspected entrapments in distal Tn usually can not discriminate between a lesion inside the TT or distal to it. The proposed technique, as suggested by the reported results in clinical application, may help to better define the lesion site.

Treatment of late complications of intra-articular calcaneal fractures.

The unfortunately frequent complications of the articular fractures of the calcaneus have a high social impact, because of the frequent and long-lasting disability that they cause. This article discusses the treatment of the late complications of intra-articular calcaneal fractures.

Sinus tarsi syndrome and subtalar joint instability.

Sinus tarsi syndrome is a poorly understood term in the orthopedic world. It is thought of as a painful condition of the sinus tarsi that often responds to corticosteroid injection and is associated with a feeling of instability in the hindfoot. Despite references in the literature, there is no agreement on pathognomonic history, clinical tests, or imaging studies that could help in confirming the diagnosis or establishing the etiology. Some authors relate the clinical condition of sinus tarsi syndrome with instability of the subtalar joint.