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Study Design: Histologic changes in the intervertebral disc were evaluated by light and electron microscopy after an intradiscal injection of methylprednisolone acetate., Objective: To evaluate the histologic changes that occur in the disc after an intradiscal injection of cortico steroids., Summary of Background Data: Several orthopedic surgeons have managed lumbar disc herniation with intradiscal steroid injection. Few studies have addressed the histologic changes after this treatment., Methods: Thirty rabbits were surgically treated. Rabbits were divided into two groups. Group A: 25 rabbits underwent intradiscal steroid injections. Methylprednisolone acetate was injected into the L3-L4 disc, whereas methylprednisolone sodium succinate was injected into the L4-L5 disc. Physiologic saline was injected into the L5-L6 disc as a control. Groups of five rabbits were killed 1 day, 1, 4, 12, and 24 weeks after the injection and subjected to microscopic evaluation. Group B: Another five rabbits underwent an injection of polyethylene glycol 4000, a vehicle for methylprednisolone acetate, into the L3-L4 and L4-L5 discs. All five rabbits were killed 24 weeks after the injection and subjected to microscopic evaluation., Results: Group A: Light microscopic evaluation showed tissue in the nucleus pulposus, and the inner layer of the anulus fibrosus had degenerated in the methylprednisolone acetate group killed 24 weeks after the injection. Matrix vesicles, an indication of primary tissue calcification, were observed by electron microscopy. In the methylprednisolone sodium succinate group and saline group, however, no histologic changes were observed. Group B: Degeneration of the nucleus pulposus and primary tissue calcification were observed in the discs of all rabbits., Conclusions: Methylprednisolone acetate and its vehicle polyethylene glycol cause degeneration and primary calcification in discs.

The introduction of microdiscectomy to lumbar spine surgery has resulted in a significant decrease in postoperative pain and length of hospital stay. Intraoperative application of long-acting local anesthetic agents has been used for many general and neurosurgical procedures for the management of postoperative pain. In addition, many surgeons routinely use intraoperative corticosteroids during lumbar discectomy to reduce traumatic nerve root inflammation. However, the efficacy of intraoperative long-acting local anesthetic agents and corticosteroids for reduction of postoperative discomfort has not been reported for lumbar discectomy. This study evaluated 32 patients at a university-based Veterans Administration hospital undergoing lumbar microdiscectomy. All 32 patients presented with radicular symptoms and had radiographic confirmation of a herniated nucleus pulposus. These patients were divided into three groups. Group 1 (12 patients) received 160 mg intramuscular Depo-Medrol (methylprednisolone acetate) and 250 mg intravenous Solu-Medrol (methyl-prednisolone sodium succinate) at the start of the operation. A macerated fat graft soaked in 80 mg Depo-Medrol was placed over the affected nerve root following discectomy. In addition, 30 ml of 0.25% bupivacaine was infiltrated into the paraspinal musculature at skin incision and during closure. Group 2 (10 patients) received 30 ml of 0.25% bupivacaine infiltrated into the paraspinal musculature at skin incision and at closure. In this group of patients, a saline-soaked fat graft was placed over the affected nerve root. Group 3 (10 patients) acted as a control group, undergoing lumbar microdiscectomy without corticosteroids or bupivacaine. Patients receiving bupivacaine and corticosteroids (Group 1) had a statistically significantly shorter hospital stay (1.4 days) compared to the control group (4.0 days) (p = 0.0004, Mann-Whitney U-test). Patients in Group 1 required less postoperative narcotic analgesia than the other groups. Finally, a larger percentage of patients in Group 1 reported complete relief of back and radicular pain on postoperative Day 1 compared to other groups. Postoperative complications and functional outcome were not different between the groups. These results indicate that the combination of long-acting anesthetic agents and corticosteroids can reduce postoperative discomfort and subsequently the length of postoperative hospital stay.

The efficacy of intramuscular methylprednisolone acetate in maintaining the antinauseant effect of intravenous methylprednisolone sodium succinate was assessed in a prospectively-randomized, double-blind, crossover-design trial. Of 150 patients entered, 127 were evaluable. There was no statistically significant difference between methylprednisolone acetate and saline placebo, although patient preferences slightly favoured the methylprednisolone acetate for nausea, vomiting, and overall effectiveness.

Acutely ill asthmatic patients treated in the usual fashion in an emergency room setting and discharged within six hours were studied to determine whether therapy with a single injection of a repository corticosteroid (methylprednisolone sodium acetate) could be as effective as a tapering course of oral corticosteroids in decreasing asthma symptomatology and relapse within seven days. Seventeen patients (18 episodes of asthma) formed the study population. Eight episodes occurred in patients who received depot methylprednisolone (group 1) and ten episodes in patients who received oral corticosteroid treatment (group 2). All patients in both groups improved following emergency room treatment. Relapse occurred in two of ten patients in group 2 and none in group 1. Symptoms attributable to asthma recurred in significantly more patients in group 2 than in group 1 (9 vs 0, p less than .01). Side effects from therapy with corticosteroids were rare. This study indicates that intramuscular repository corticosteroids are at least as effective as oral corticosteroids in the management of the acute asthmatic outpatient, with a distinct advantage with regard to patient compliance.

The absolute bioavailability and pharmacokinetic parameters of two methylprednisolone formulations (methylprednisolone sodium succinate and methylprednisolone acetate) were determined in five dogs. Plasma concentrations of methylprednisolone, methylprednisolone sodium succinate, and methylprednisolone acetate were measured by sensitive and specific high-performance liquid chromatographic methods. After intravenous methylprednisolone sodium succinate administration, methylprednisolone was released rapidly but the extent of availability was rather low (43.6%). This has been tentatively explained in terms of its subsequent single-pass metabolism in the liver, i.e., hepatic hydrolysis of methylprednisolone sodium succinate followed by immediate hepatic elimination of the released methylprednisolone. After intramuscular administration of methylprednisolone acetate, its absorption was slow (half-time of absorption, 69.04 h) and the availability of the released methylprednisolone was low (42.7%). Therapeutic implications of these results are discussed, especially those which are relevant to shock therapy.