Radiofrequency ablation prior to total knee arthroplasty does not improve post-surgical pain or recovery: a double-blinded, multi-center, randomized clinical trial

Background

Radiofrequency ablation (RFA) targeting the genicular nerves is an effective treatment for knee pain due to osteoarthritis. The aim of this study was to determine the effects of two RFA interventions delivered preoperatively on early postoperative pain management and subjective outcomes after total knee arthroplasty (TKA).

Methods

One hundred forty-three participants were enrolled in this double blinded, sham-controlled prospective randomized trial. Participants assigned at random to traditional RFA (t-RFA) (n=50), cooled RFA (c-RFA) (n=49), or sham (n=44) procedures prior to TKA. Outcomes were recorded at postoperative day 3, week 1, week 2, week 12, month 6, and month 12 following TKA. Primary outcomes included hospital length of stay (LOS), opioid consumption (reported as MEQ, or daily morphine equivalents), time to narcotic cessation (reported in days), and pain scores (reported as NRS, or Numeric Rating Scale). Secondary outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) measures. All side effects and complications were reported. Participants were followed for a year to detect any unexpected side effects.

Results

Compared with sham controls, t-RFA and c-RFA did not affect inpatient LOS, pain scores, or opioid consumption. There were no reductions in time to opioid cessation, pain scores, or WOMAC scores at any time point post-TKA.

Conclusions

RFA of the genicular nerves prior to TKA did not affect opioid use or time to cessation, pain, or WOMAC scores, following TKA. Current techniques of t-RFA and c-RFA of these specific geniculate nerves preoperatively are not indicated as routine interventions to improve short-term surgical recovery after TKA.

Trial Registration

The trial was registered on ClinicalTrials.gov (NCT02925442).

A systematic review of occipital cervical fusion: techniques and outcomes

Object

Numerous techniques have been historically used for occipitocervical fusion with varied results. The purpose of this study was to examine outcomes of various surgical techniques used in patients with various disease states to elucidate the most efficacious method of stabilization of the occipitocervical junction.

Methods

A literature search of peer-reviewed articles was performed using PubMed and CINAHL/Ovid. The key words “occipitocervical fusion,” “occipitocervical fixation,” “cervical instrumentation,” and “occipitocervical instrumentation” were used to search for relevant articles. Thirty-four studies were identified that met the search criteria. Within these studies, 799 adult patients who underwent posterior occipitocervical fusion were analyzed for radiographic and clinical outcomes including fusion rate, time to fusion, neurological outcomes, and the rate of adverse events.

Results

No articles stronger than Class IV were identified in the literature. Among the patients identified within the cited articles, the use of posterior screw/rod instrumentation constructs were associated with a lower rate of postoperative adverse events (33.33%) (p < 0.0001), lower rates of instrumentation failure (7.89%) (p < 0.0001), and improved neurological outcomes (81.58%) (p < 0.0001) when compared with posterior wiring/rod, screw/plate, and onlay in situ bone grafting techniques. The surgical technique associated with the highest fusion rate was posterior wiring and rods (95.9%) (p = 0.0484), which also demonstrated the shortest fusion time (p < 0.0064). Screw/rod techniques also had a high fusion rate, fusing in 93.02% of cases.

When comparing outcomes of surgical techniques depending on the disease status, inflammatory diseases had the lowest rate of instrumentation failure (0%) and the highest rate of neurological improvement (90.91%) following the use of screw/rod techniques. Occipitocervical fusion performed for the treatment of tumors by using screw/rod techniques had the lowest fusion rate (57.14%) (p = 0.0089). Traumatic causes of occipitocervical instability had the highest percentage of pain improvement with the use of screw/plates (100% improvement) (p < 0.0001).

Conclusions

Based on the existing literature, techniques that use screw/rod constructs in occipitocervical fusion are associated with very favorable outcomes in all categories assessed for all disease processes. For patients requiring occipitocervical arthrodesis for the treatment of inflammatory diseases, screw/rod constructs are associated with the most favorable outcomes, while posterior wiring and onlay in situ bone grafting is associated with the least favorable outcomes. Occipitocervical arthrodesis performed for the diagnosis of tumor is associated with the lowest rate of successful arthrodesis using screw/rod techniques, while posterior wiring and rods have the highest rate of arthrodesis. The nonspecified disease group had the lowest rate of surgical adverse events and the highest rate of neurological improvement.

Complications in the management of Charcot spinal arthropathy

Charcot spinal arthropathy is a relatively rare, destructive process characterized by a cycle of progressive deformity, destruction, and worsening instability as a result of repetitive trauma and inflammation. It may result from nontraumatic as well as traumatic causes. Historically, patients with severe symptomatic instability have been successfully treated with combined anterior and posterior fusion techniques. The long-term outcomes and potential complications, however, have not been well reported. The authors report on 2 such cases of Charcot spinal arthropathy treated surgically, one with a traumatic and one with a nontraumatic etiology. They include the unique pitfalls encountered while treating these patients, as well as their surgical treatments, complications, and long-term results.

Recurrent atlantoaxial instability due to fracture of the posterior C1 ring: a late finding following posterior C1-C2 fusion using the Halifax clamp

Although its use has fallen out of favor, the Halifax interlaminar clamp was used for many years to treat cervical instability through a posterior approach. Numerous complications, the majority of which are related to hardware failure, have been reported with the use of the interlaminar clamps and have led to the development of alternative techniques for posterior fusion, such as transarticular screw fixation. This report presents a case of recurrent atlantoaxial instability due to fracture of the posterior C1 ring that occurred 12 years after a posterior C1-C2 fusion with Halifax clamps. To the authors' knowledge, this is the first case report of symmetric fractures through the posterior C1 ring lateral to the site of the Halifax clamps, resulting in recurrent atlantoaxial instability. This report focuses on the surgical management of this complication and provides a review of the literature that pertains to complications following the use of the Halifax clamp to treat atlantoaxial instability.

Physiology of resuscitation

Ischemia ultimately leads to loss of thermodynamic order in all cells. During ischemia and reperfusion, the influx of Ca2+ ions appears to initiate a number of cell processes, the reversal of which depends on the re-establishment and maintenance of adequate organ perfusion and high energy metabolism. Promising therapeutic approaches for accomplishing these goals include substrate augmentation, inhibition of calcium-activated injury, membrane stabilization, manipulation of the cycloxygenase and lipoxygenase reactions, and the use of free radical scavengers.

Cerebral cortical perfusion during and following resuscitation from cardiac arrest in dogs

Perfusion of the cerebral cortex during closed chest CPR in dogs, generating systolic pressures of 60 to 70 mmHg, is only 10% of pre-arrest blood flow. In contrast, internal cardiac massage produces normal cortical perfusion rates. Following a 20-min perfusion arrest, during pressure controlled reperfusion, cortical flow rates decay to less than 20% normal after 90 min of reperfusion. This appears to be due to increasing cerebral vascular resistance, and is not due to rising intracranial pressure. The post-arrest cortical hypoperfusion syndrome is prolonged with cortical flow remaining below 20% normal up to 18 hr post arrest. The use of a variety of calcium antagonists, including flunarizine, lidoflazine, verapamil, and Mg2+, immediately post-resuscitation maintains cerebral vascular resistance and cortical perfusion at normal levels. A prospective blind trial of the calcium antagonist lidoflazine following a 15-min cardiac arrest in dogs and resuscitation by internal massage, demonstrates amelioration of neurologic deficit in the early postresuscitation period.

Calcium blockers in cerebral resuscitation

Recent studies on cerebral resuscitation following an ischemic anoxic insult suggest that both inadequate reperfusion and direct neuronal death are partially initiated by calcium entry into vascular smooth muscle and neurons. To investigate the effects of calcium blocking agents on cerebral resuscitation, a controlled perfusion arrest model with cardiopulmonary bypass was used. Post-resuscitation regional cerebral cortical blood flow (rCCBF) and intracranial pressures (ICP) were monitored in five control dogs and in 12 study dogs resuscitated after a prolonged (20-minute) cardiac arrest. The resuscitation included dexamethasone and three agents thought to be calcium entry antagonists and to offer potential cerebral protection after complete prolonged cerebral ischemic anoxia. Prearrest rCCBF measured by a thermal dilution method with a thermistor placed on the cerebral cortex was 2.0 +/- 0.6 (S.D.) ml/gm/min on bypass at 100 mm Hg mean arterial pressure. Twenty minutes after resuscitation was begun, the rCCBF in ml/min/gm were: controls 1.1 +/- 0.3; dexamethasone (2 mg/kg) 1.2 +/- 0.4; MgSO4 (100 mg/kg) 1.8 +/- 0.5; verapamil (0.15 mg/kg) 1.9 +/- 0.4; and lidoflazine (1 mg/kg) 1.5 +/- 0.3. Ninety minutes following the beginning of resuscitation the rCCBF were: controls 0.1 +/- 0.1; dexamethasone 0.1 +/- 0.1; MgSO4, 1.7 +/- 0.3; verapamil, 1.9 +/- 0.4; and lidoflazine, 1.5 +/- 0.3 ml/gm/min. Thus the Ca2+ entry antagonists maintained cerebral blood flow at 20 and 90 minutes following a prolonged ischemic anoxic insult. Dexamethasone was no better than control. These data suggest that calcium entry blockers can maintain rCCBF and may have a significant role in cerebral resuscitation following cardiac arrest.