The effect of cyclooxygenase-2 inhibition on analgesia and spinal fusion

Endogenous opiates and behavior: 2005

This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).

The role of COX-2 inhibitors in the treatment of postoperative pain

Postoperative pain requires treatment not only to provide comfort to patients but also to improve postoperative outcome. Anti-inflammatory compounds are an important component of multimodal analgesia in the postoperative period. The newer cyclooxygenase (COX)-2 inhibitors are as effective as classical nonsteroidal anti-inflammatory drugs (NSAIDs) in this setting. However, COX-2 inhibitors offer a number of advantages over NSAIDs when used to treat postoperative pain. These include a reduced incidence of gastrointestinal ulceration and no inhibitory effect on platelet function and thereby a reduced risk of blood loss. Other benefits are less impairment of bone healing and no induction of bronchospasm in patients with aspirin-sensitive asthma. Increased cardiovascular thromboembolic events by COX-2 inhibitors have been reported after coronary artery bypass graft surgery only, but in general, surgery studies the incidence of such complications was comparable to placebo. Overall, COX-2 inhibitors offer a number of advantages over classical NSAIDs in the postoperative pain setting, but require the same caution with regard to renal effects.

The Analgesic Efficacy of Celecoxib, Pregabalin, and Their Combination for Spinal Fusion Surgery: Retracted

BACKGROUND

As optimal pain relief after surgery is difficult to achieve with the use of just one drug, many pain experts advocate the use of two or more classes of medications so as to reduce the side effects from any one drug. In this trial, we assessed the analgesic efficacy of administering perioperative celecoxib, pregabalin, or both after spinal fusion surgery.

METHODS

Eighty patients scheduled to undergo elective decompressive lumbar laminectomy with posterior spinal fusion were randomized to receive oral medications: placebo 1 h before and 12 h after surgery, celecoxib 400 mg 1 h before and celecoxib 200 mg 12 h after surgery, pregabalin 150 mg 1 h before and 12 h after surgery, or a pregabalin/celecoxib combination of 400 mg/150 mg 1 h before and 200 mg/150 mg 12 h after surgery.

RESULTS

The pregabalin/celecoxib group consumed the least patient-controlled morphine. Celecoxib alone or pregabalin alone also reduced opioid use compared with placebo, but not as much as when combined. The pregabalin/celecoxib combination was the most effective treatment for reducing pain both at rest and with movement over the 24-h postoperative time period. Hemodynamics and respiratory rate did not differ among the four treatment groups. Fewer patients experienced nausea in the pregabalin/celecoxib group compared with that in the placebo group.

CONCLUSION

The perioperative administration of the combination of celecoxib and pregabalin improved analgesia and caused fewer side effects, than either analgesic drug alone after spinal fusion surgery.

Does celecoxib have an adverse effect on bone remodeling and ingrowth in humans?

Although celecoxib may provide perioperative pain relief, the effect of the short-term use of celecoxib on bone ingrowth into porous-coated devices has not been previously studied in humans. Bone ingrowth into titanium and tantalum plugs was measured in nine patients who underwent staged bilateral total knee arthroplasty (TKA) and were taking celecoxib as part of a perioperative pain relief protocol. Patients were given tetracycline to measure the mineral apposition rate before and after celecoxib administration. Time zero plugs were implanted and retrieved during the first TKA, and 12 weeks later the contralateral implanted plugs were retrieved at the second TKA. The mineral apposition rate was similar for the titanium (0.97 microm per day) and the tantalum (1.15 microm per day) plugs at 12 weeks as was bone ingrowth (886 microm versus 632 microm, respectively). Celecoxib does not seem to inhibit bone ingrowth or bone formation.

Perioperative medication management for the patient with rheumatoid arthritis

The treatment of rheumatoid arthritis has improved dramatically in recent years with the advent of the latest generation of disease-modifying antirheumatic drugs. Despite these advances, in some patients inflammation is not diminished sufficiently to prevent irreversible musculoskeletal damage, thus requiring surgical intervention to reduce pain and improve function. In these cases, the orthopaedic surgeon frequently encounters patients on a drug regimen consisting of nonsteroidal anti-inflammatory drugs, glucocorticoids, methotrexate, and biologic agents (disease-modifying antirheumatic drugs). Consultation with a rheumatologist is recommended, but the surgeon also should be aware of these medications that could potentially affect surgical outcome. Prudent perioperative management of these drugs is required to optimize surgical outcome. A balance must be struck between minimizing potential surgical complications and maintaining disease control to facilitate postoperative rehabilitation of patients with rheumatoid arthritis.

Pharmacologic agents in fracture healing

Bone fractures are a known risk of athletic participation and can result in significant lost playing time. A variety of medications have been investigated in animal studies regarding their effects on fracture healing. Parathyroid hormone and the bisphosphonates may have future uses in the prevention and treatment of athletic-related stress fractures and acute fractures. Nonsteroidal anti-inflammatory drugs have been implicated in effecting fracture healing in some animal models, but little clinical evidence supports these findings. Large randomized clinical trials are needed to further delineate the role of these and other drugs and their effects on fracture healing.

COX-2 has a Critical Role During Incorporation of Structural Bone Allografts

Nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit cyclooxygenase (COX) activity, reduced pain and are commonly used in patients with skeletal injury. In this article we will also present data to show that selective COX-2 inhibitor delays allograft healing and incorporation. In contrast, local delivery of prostaglandin E2 (PGE2) enhanced bone formation at cortical bone graft junction. A 4-mm mid-diaphyseal segmental femoral defect was created and then repaired by frozen bone allograft of the same size. A 22-gauge metal pin was placed in the intramedullary cavity to stabilize the bone graft. Healing was evaluated weekly by X ray and by a semiquantitative histomorphometric analysis at 5 weeks postsurgery. Celecoxib (25 mg/kg/day) and Ketorolac (4 mg/kg/day) were administered daily for 2 weeks or 5 weeks. PGE2 was infused locally at a dose of 800 nmol/kg per day via osmotic minipump for 4 weeks. Inhibition of cyclooxygenase by daily administration of the Celecoxib or Ketorolac for 5 weeks reduced new bone ingrowth by about 60% (P < 0.05). The percentage of bony bridging in both drug-treated groups was significantly decreased at 5 weeks. Temporal administration of Celecoxib for 2 weeks also significantly reduced bone formation by 45% and withdrawal of the Celecoxib only led to slight recovery of bone formation at the graft side. In contrast to the inhibitory effects of NSAIDS, PGE2 infusion at the cortical bone junction increased bone formation by about twofold. These results demonstrated that COX-2 is essential for bone allograft incorporation. Furthermore, our data support the notion that COX-2-dependent PGE2 produced at the early stage of bone healing is prerequisite for efficient skeletal repair.

Practical management: nonsteroidal antiinflammatory drug (NSAID) use in athletic injuries

Nonsteroidal antiinflammatory drugs (NSAIDs) are frequently used in the treatment of acute athletic injuries, often for analgesic purposes as the evidence to support enhanced healing is limited. However, the current evidence on NSAID use in athletic injury is slowly growing. On the basis of animal models and limited human studies, some practical management guidelines can be drawn to assist the sports physician. Specifically, NSAIDs are not recommended in the treatment of completed fractures, stress fractures at higher risk of nonunion, or in the setting of chronic muscle injury. The only exception may be very short-term use (eg, a few days) for analgesic purposes only. Judicious use of NSAIDs may be more appropriate in the management of acute ligament sprains, muscle strains, tendinitis, and eccentric muscle injury. However, length of treatment should always be kept as short as possible, with consideration of the specific type of injury, level of dysfunction, and pain.

High dose nonsteroidal anti-inflammatory drugs compromise spinal fusion

PURPOSE

Although nonsteroidal anti-inflammatory drugs (NSAIDs) provide benefit to patients following spinal fusion surgery, their routine administration has remained controversial due to concerns about possible deleterious effects on bone healing. The goal of this retrospective study was to assess the incidence of non-union following the perioperative administration of ketorolac, celecoxib, or rofecoxib.

METHODS

We retrospectively analyzed the data of 434 patients receiving perioperative ketorolac (20-240 mg.day(-1)), celecoxib (200-600 mg.day(-1)), rofecoxib (50 mg.day(-1)), or no NSAIDs in the five days following spinal fusion surgery.

RESULTS

There were no significant differences in the incidence of non-union among the groups that received no NSAIDs (11/130; 8.5%), celecoxib 5/60; 8.3%), or rofecoxib (9/124; 7.3%). In contrast, 23/120 of patients (19.2%) that received ketorolac had a higher incidence (P < 0.001) of non-union compared to non-NSAID users. However, only 3/50 patients (6%) receiving low-dose ketorolac (< or = 110 mg.day(-1)) resulted in non-union which was not significantly different from non-NSAID users. Patients administered higher doses of ketorolac (120-240 mg.day(-1)) resulted in a higher incidence (P < 0.0001) of non-union (20/70; 29%) compared to non-NSAID users. For those patients developing non-union, there was a higher incidence comparing smokers vs non-smokers (P < 0.0001) and one level fusion vs two level fusions (P < 0.001).

CONCLUSIONS

This study revealed that the short-term perioperative administration of celecoxib, rofecoxib, or low-dose ketorolac (< or = 110 mg.day(-1)) had no significant deleterious effect on non-union. In contrast, higher doses of ketorolac (120-240 mg.day(-1)), history of smoking, and two level vertebral fusions resulted in a significant increase in the incidence of non-union following spinal fusion surgery.