Surgery versus chemonucleolysis for herniated lumbar discs. A prospective study with random assignment

The results of removal of a disc hernia at the L4/L5 level were compared with those obtained by the injection of 4000 IU (2 ml) of chymopapain (Discase) in 29 consecutive patients randomly selected for either treatment. All exhibited severe incapacitating sciatica, and all had a myelogram demonstrating a definite disc hernia. The two groups of patients did not differ significantly with regard to age, sex, or length of history. The total time of general anesthesia was significantly shorter for the injected patients by 20 minutes (p less than 0.01), as was the length of hospitalization, by three days (p less than 0.05). Within five months, eight of the patients receiving chymopapain injections had to be operated on because of unrelieved symptoms. All had definite disc herniae, and in four, a free fragment was found. All patients were seen at the time of dismissal from the hospital and at six and 12 months after operation by an independent observer. Comparisons made at these intervals, following either surgery or chymopapain injection with or without subsequent surgery, did not reveal any significant differences, but the short-term results following either treatment alone significantly (p less than 0.01) favored the surgical approach.     

The Effect of Impact Loading on Rabbit Knee Joints

Eighteen mature male Whiteland rabbits received repetitive impulse loads slightly larger than body weight (4 kp) through one knee joint for periods from 1 to 6 weeks. Mechanical compression of subchondral bone cores from impacted tibiae showed progressive increased deformation under a constant force. Cartilage degeneration occurred concurrently with alterations in the mechanical properties of the subchondral bone. The cartilage degeneration may be explained by: (i) the deleterious effect of repetitive mechanical compression, (ii) the decreased mechanical support of the underlying subchondral bone.     

Visualization of regenerating sciatic nerve fibres by neurofilament immunohistochemistry

Regeneration of injured sciatic nerve in rats was studied with an immunohistochemical technique visualizing neurofilaments in nerve fibres as well as S-100 protein in Schwann cells. Outgrowing axons with delicate sprouts could be demonstrated along pathways formed by Schwann cells. In contrast, axons which had stopped growing or were degenerating showed bulb-like swellings in their terminal parts. The use of immunohistochemical techniques offers advantages over conventional neurohistochemical staining methods, enabling more detailed observations of nerve regeneration mechanisms in animals.