Parecoxib impairs early metaphyseal bone healing in rats

Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model

Objectives

Experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) may have negative effects on fracture healing. This study aimed to assess the effect of immediate and delayed short-term administration of clinically relevant parecoxib doses and timing on fracture healing using an established animal fracture model.

Methods

A standardized closed tibia shaft fracture was induced and stabilized by reamed intramedullary nailing in 66 Wistar rats. A ‘parecoxib immediate’ (Pi) group received parecoxib (3.2 mg/kg bodyweight twice per day) on days 0, 1, and 2. A ‘parecoxib delayed’ (Pd) group received the same dose of parecoxib on days 3, 4, and 5. A control group received saline only. Fracture healing was evaluated by biomechanical tests, histomorphometry, and dual-energy x-ray absorptiometry (DXA) at four weeks.

Results

For ultimate bending moment, the median ratio between fractured and non-fractured tibia was 0.61 (interquartile range (IQR) 0.45 to 0.82) in the Pi group, 0.44 (IQR 0.42 to 0.52) in the Pd group, and 0.50 (IQR 0.41 to 0.75) in the control group (n = 44; p = 0.068). There were no differences between the groups for stiffness, energy, deflection, callus diameter, DXA measurements (n = 64), histomorphometrically osteoid/bone ratio, or callus area (n = 20).

Conclusion

This study demonstrates no negative effect of immediate or delayed short-term administration of parecoxib on diaphyseal fracture healing in rats.

Cite this article: G. A. Hjorthaug, E. Søreide, L. Nordsletten, J. E. Madsen, F. P. Reinholt, S. Niratisairak, S. Dimmen. Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model. Bone Joint Res 2019;8:472–480. DOI: 10.1302/2046-3758.810.BJR-2018-0341.R1.

Inter-trabecular bone formation: a specific mechanism for healing of cancellous bone

Background and purpose - Studies of fracture healing have mainly dealt with shaft fractures, both experimentally and clinically. In contrast, most patients have metaphyseal fractures. There is an increasing awareness that metaphyseal fractures heal partly through mechanisms specific to cancellous bone. Several new models for the study of cancellous bone healing have recently been presented. This review summarizes our current knowledge of cancellous fracture healing. Methods - We performed a review of the literature after doing a systematic literature search. Results - Cancellous bone appears to heal mainly via direct, membranous bone formation that occurs freely in the marrow, probably mostly arising from local stem cells. This mechanism appears to be specific for cancellous bone, and could be named inter-trabecular bone formation. This kind of bone formation is spatially restricted and does not extend more than a few mm outside the injured region. Usually no cartilage is seen, although external callus and cartilage formation can be induced in meta-physeal fractures by mechanical instability. Inter-trabecular bone formation seems to be less sensitive to anti-inflammatory treatment than shaft fractures. Interpretation - The unique characteristics of inter-trabecular bone formation in metaphyseal fractures can lead to differences from shaft healing regarding the effects of age, loading, or drug treatment. This casts doubt on generalizations about fracture healing based solely on shaft fracture models.

Periarticular infiltration for pain relief after total hip arthroplasty: a comparison with epidural and PCA analgesia

PURPOSE

Epidural and intravenous patient-controlled analgesia (PCA) are established methods for pain relief after total hip arthroplasty (THA). Periarticular infiltration is an alternative method that is gaining ground due to its simplicity and safety. Our study aims to assess the efficacy of periarticular infiltration in pain relief after THA.

METHODS

Sixty-three patients undergoing THA under spinal anaesthesia were randomly assigned to receive postoperative analgesia with continuous epidural infusion with ropivacaine (epidural group), intraoperative periarticular infiltration with ropivacaine, clonidine, morphine, epinephrine and corticosteroids (infiltration group) or PCA with morphine (PCA group). PCA morphine provided rescue analgesia in all groups. We recorded morphine consumption, visual analog scale (VAS) scores at rest and movement, blood loss from wound drainage, mean arterial pressure (MAP) and adverse effects at 1, 6, 12, 24 h postoperatively.

RESULTS

Morphine consumption at all time points, VAS scores at rest, 6, 12 and 24 h and at movement, 6 and 12 h postoperatively were lower in infiltration group compared to PCA group (p < 0.05), but did not differ between infiltration and epidural group. There was no difference in adverse events in all groups. At 24 h, MAP was higher in the PCA group (p < 0.05) and blood loss was lower in the infiltration group (p < 0.05).

CONCLUSIONS

In our study periarticular infiltration was clearly superior to PCA with morphine after THA, providing better pain relief and lower opioid consumption postoperatively. Infiltration seems to be equally effective to epidural analgesia without having the potential side effects of the latter.

Effects of a selective cyclooxygenase-2 inhibitor (celecoxib) on fracture healing in rats

BACKGROUND

Several studies suggested that celecoxib interferes with bone healing while others contradict these findings. This study was conducted to investigate the effects of celecoxib on bone healing in rats femur mold with a dose based on body surface area conversion.

MATERIALS AND METHODS

72 adult female Sprague Dawley rats were randomly divided into three groups after the internal fixation operation of nondisplaced transverse mid diaphyseal fractures of the right femurs. Each group was treated with 1% methylcellulose, celecoxib (21 mg/kg/d) for 1 week, or celecoxib (21 mg/kg/d) for 4 weeks after surgeries respectively. Bone healing scores and callus formation were evaluated by radiographs at 3, 4, 6 weeks after surgeries. Half of these rats were sacrificed for histological analysis at 4 weeks after surgery. The remaining fractured femurs were evaluated by biomechanical tests at 6 weeks after surgery.

RESULTS

The mean radiographic scores for fracture healing of both short and long term groups were lower than that of the control group and the differences among the three groups were statistically significant (P < 0.05) at 3, 4, 6 weeks after surgery. The mean bone trabecula density of both groups was smaller than that of the control group and the differences were also statistically significant (P < 0.05) at 4 week. The maximum load, total energy and stiffness in both the short term and long term groups were significantly decreased compared with those in the control group (P < 0.05) at 6 week.

CONCLUSION

Both short term and long term sustained use of celecoxib in rat models has significantly inhibitory effects on rat fracture healing.

Effects of interleukin-6 ablation on fracture healing in mice

This study examined the impact of an interleukin-6 (IL-6) knockout on fracture healing in terms of histological and biomechanical responses. Following IACUC approval, tibial fractures were produced in 4- to 6-week-old IL-6 knockouts (n = 35) and wild-type mice (n = 36) and harvested along with contralateral limbs at 2 and 6 weeks postsurgery. Histology quantified stage of healing, lymphocyte infiltration, TRAP+ cells, and osteocalcin deposition. Bend testing established maximum load and stiffness. Based on normality assessments, Mann-Whitney U or independent t-tests were used for data analysis using a p-value threshold of 0.05. Stage of healing, lymphocyte infiltration, and osteocalcin deposition were similar for all time points (p ≥ 0.243). TRAP+ cell counts were reduced approximately 10-fold in the knockout at 2 weeks (p = 0.015) but were similar at 6 weeks (p = 0.689). Force-to-failure in knockouts was approximately 40% that of wild-type mice at 2 weeks (p = 0.040) but similar at 6 weeks (p = 0.735). Knockout bone was about 25% less stiff at 2 weeks but approximately 60% stiffer at 6 weeks (p ≥ 0.110). The absence of IL-6 during early fracture healing significantly reduced osteoclastogenesis and impaired callus strength. By 6 weeks, most histological and biomechanical parameters were similar to fractures in wild-type bone.

Reduced morphine consumption and pain intensity with local infiltration analgesia (LIA) following total knee arthroplasty

BACKGROUND AND PURPOSE

Postoperative pain is often severe after total knee arthroplasty (TKA). We investigated the efficacy of the local infiltration analgesia (LIA) technique, both intraoperatively and postoperatively.

METHODS

48 patients undergoing TKA were randomized into 2 groups in a double-blind study. In group A, 400 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine were infiltrated periarticularly during operation. In group P, no injections were given. 21 h postoperatively, 200 mg ropivacaine, 30 mg ketorolac, and 0.1 mg epinephrine were injected intraarticularly in group A, and the same volume of saline was injected in group P. All patients were followed up for 3 months.

RESULTS

Median morphine consumption was lower in group A during the first 48 h: 18 (1-74) mg vs. 87 (36-160) mg in group P. Postoperative pain was lower at rest in group A during the first 27 h, and on movement during the first 48 h, except at 21 h. Time to fulfillment of discharge criteria was shorter in group A than in group P: 3 (1-7) vs. 5 (2-8) days. Patient satisfaction was higher in group A than in group P on days 1 and 7. The unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations.

INTERPRETATION

The local infiltration analgesia (LIA) technique provides excellent pain relief and lower morphine consumption following TKA, resulting in shorter time to home readiness and higher patient satisfaction. There were few side effects and systemic LA concentrations were low.

Parecoxib has non-significant long-term effects on bone healing in rats when administered for a short period after fracture

INTRODUCTION

Selective and non-selective cyclo-oxygenase (COX) inhibitors impair bone healing by inhibiting prostaglandin synthesis. The purpose of this study was to evaluate the long-term effect of parecoxib, a selective COX-2 inhibitor, on bone healing in rats, when it is applied in a pattern similar to clinical treatment patterns, that is, in a high dose and for a short period after bone fracture.

METHOD

Closed non-displaced mid-diaphyseal fractures in the middle of the left femoral shaft were generated in each animal. In the study group, parecoxib sodium (1.06 mg/kg) was administered intra-peritoneally every day for 7 days. In the control group, normal saline was administered intra-peritoneally every day for 7 days. In both groups fracture healing (bone union and callus formation) was evaluated with X-rays 28 and 42 days after surgery.

RESULTS

Bone healing was lower in the study group (60 vs. 80% in the control group 28 days after fracture and 80 vs. 90% 42 days after fracture) but this difference was not statistically significant (P > 0.05).

CONCLUSION

Parecoxib does not have a significant long-term effect on bone healing in rats, when it is administered in a high dose and for a short period after bone fracture.

The use of NSAIDs in pediatric scoliosis surgery - a survey of physicians' prescribing practice

BACKGROUND

Pediatric scoliosis surgery is associated with considerable postoperative pain requiring opioids for analgesia. Nonsteroidal antiinflammatory drugs (NSAIDs) can be used as adjuvants for analgesia; however, the potential of these agents to affect bone healing raises concerns. No large-scale prospective studies have been performed to evaluate the benefit-to-risk ratio of NSAID use after pediatric scoliosis surgery. Given the lack of evidence in the literature, a survey of practice patterns of anesthesiologists from around the world was conducted with respect to the use of NSAIDs after pediatric spinal fusion surgery for scoliosis.

METHODS

One hundred and fourteen anesthesiologists from international academic pediatric hospitals were asked to complete an online survey. After 1 month, nonresponders were sent a second e-mail asking for their participation. All questions were developed specifically for this study.

RESULTS

Out of 80 anesthesiologists who responded 61 were included in the final analysis. Fifty-nine percent routinely use NSAIDs, the most common agents being intravenous ketorolac and oral ibuprofen. The majority of respondents begin to administer NSAIDs within the first three postoperative days for a duration of four or more days. The primary reason for not routinely prescribing NSAIDs was the risk of bone nonunion.

CONCLUSIONS

This survey demonstrates that the practice patterns of pediatric anesthesiologists from around the world with respect to the administration of NSAIDs for the management of postoperative pain after pediatric spinal fusion reflects the conflicting evidence in the literature and the lack of high-quality studies in humans.

Parecoxib and indomethacin delay early fracture healing: a study in rats

Nonsteroidal antiinflammatory drugs (NSAIDs) are used to reduce inflammatory response and pain. These drugs have been reported to impair bone metabolism. Parecoxib, a specific COX-2 inhibitor, exerts an inhibitory effect on the mineralization of fracture callus after a tibial fracture in rats. Decreased bone mineral density (BMD) at a fracture site may indicate impairment of early healing, casting doubt on the safety of using COX-2 inhibitors during the early treatment of diaphyseal fractures. Forty-two female Wistar rats were randomly allocated to three groups. They were given parecoxib, indomethacin, or saline intraperitoneally for 7 days after being subjected to a closed tibial fracture stabilized with an intramedullary nail. Two and 3 weeks after surgery, the bone density at the fracture site was measured using dual energy xray absorptiometry (DEXA). Three weeks after the operation the rats were euthanized and the healing fractures were mechanically tested in three-point cantilever bending. Parecoxib decreased BMD at the fracture site for 3 weeks after fracture, indomethacin for 2 weeks. Both parecoxib and indomethacin reduced the ultimate bending moment and the bending stiffness of the healing fractures after 3 weeks. These results suggest COX inhibitors should be avoided in the early phase after fractures.

Celecoxib does not appear to affect prosthesis fixation in total knee replacement: A randomized study using radiostereometry in 50 patients

BACKGROUND AND PURPOSE

After joint replacement, a repair process starts at the interface between bone and cement. If this process is disturbed, the prosthesis may never become rigidly fixed to the bone, leading to migration-and with time, loosening. Cox-2 inhibitors are widely used as postoperative analgesics, and have adverse effects on bone healing. This could tamper prosthesis fixation. We investigated whether celecoxib, a selective Cox-2 inhibitor, increases prosthesis migration in total knee replacement (TKR).

METHODS

50 patients were randomized to either placebo or celecoxib treatment, 200 mg twice daily, for 3 weeks after TKR (NexGen; Zimmer). Maximum total point motion (MTPM) of the tibial component was measured after 2 years using radiostereometric analysis (RSA). In addition, range of motion, pain, and, subjective outcome were evaluated.

RESULTS

No differences in prosthesis migration, pain scores, range of motion, and subjective outcome were found after 2 years. Confidence intervals were narrow.

INTERPRETATION

It is unlikely that Celecoxib increases the risk of loosening, and it may be used safely in conjunction with TKR.

The effect of parecoxib and indometacin on tendon-to-bone healing in a bone tunnel

Conventional non-steroidal anti-inflammatory drugs (NSAIDs) and newer specific cyclo-oxygenase-2 (cox-2) inhibitors are commonly used in musculoskeletal trauma and orthopaedic surgery to reduce the inflammatory response and pain. These drugs have been reported to impair bone metabolism. In reconstruction of the anterior cruciate ligament the hamstring tendons are mainly used as the graft of choice, and a prerequisite for good results is healing of the tendons in the bone tunnel. Many of these patients are routinely given NSAIDs or cox-2 inhibitors, although no studies have elucidated the effects of these drugs on tendon healing in the bone tunnel.

In our study 60 female Wistar rats were randomly allocated into three groups of 20. One received parecoxib, one indometacin and one acted as a control. In all the rats the tendo-Achillis was released proximally from the calf muscles. It was then pulled through a drill hole in the distal tibia and sutured anteriorly. The rats were given parecoxib, indometacin or saline intraperitoneally twice daily for seven days. After 14 days the tendon/bone-tunnel interface was subjected to mechanical testing.

Significantly lower maximum pull-out strength (p < 0.001), energy absorption (p < 0.001) and stiffness (p = 0.035) were found in rats given parecoxib and indometacin compared with the control group, most pronounced with parecoxib.

Negative effect of parecoxib on bone mineral during fracture healing in rats

BACKGROUND AND PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) are conventional cyclooxygen-ase (cox) inhibitors commonly used in musculoskeletal trauma to reduce the inflammatory response and pain, but they also seem to affect bone metabolism. Parecoxib is a cox inhibitor that selectively inhibits cox-2. Through their selective mechanism of action, these newer drugs are supposed to reduce the gastrointestinal side effects of conventional cox inhibitors. The effects on bone metabolism and healing have, however, not been fully elucidated. Thus, there are reasons for concern regarding the potential negative effects of these drugs on bone metabolism and bone repair. We investigated the effects of short-term administration of parecoxib on bone mineral formation and bone healing in rats.

ANIMALS AND METHODS

26 female Wistar rats were given parecoxib intraperitoneally for 7 days after a closed tibial fracture that was stabilized with an intra-medullary nail, and 26 animals were given saline. At 2, 3, and 6 weeks after surgery bone mineral density (BMD) at the fracture site was measured using dualenergy X-ray absorptiometry (DEXA). 6 weeks after the fracture, 14 rats from the parecoxib group and 16 rats from the placebo group were killed for mechanical testing, and the rest of the animals were killed for tissue analysis. The healing fractures and the intact contralateral tibias were mechanically tested by three-point cantilever bending.

RESULTS

The BMD at the fracture site was calculated as the average of the results after 2,3, and 6 weeks. Mean BMD was lower in the parecoxib group, 0.23 (SD 0.06) g/ cm2, than in the control group, 0.27 (SD 0.05) g/cm2 (p = 0.01). There were no statistically significant differences in mechanical properties of the healing fractures after 6 weeks. However, the study may have lacked sufficient statistical power to determine whether a negative effect on healing had occurred.

INTERPRETATION

No mechanical differences were detected between the control and treatment groups after 6 weeks, but they may have been present earlier in the fracture healing process. Our findings do, however, indicate that parecoxib given postoperatively for a week has a negative effect on mineralization during the early phase of fracture healing.