Periarticular needle-based therapies can cause periprosthetic knee infections

Comparison of cooled versus conventional radiofrequency treatment of the genicular nerves for chronic knee pain: a multicenter non-inferiority randomized pilot trial (COCOGEN trial)

BACKGROUND

Radiofrequency (RF) treatment of the genicular nerves has the potential to reduce chronic knee pain due to osteoarthritis or persistent postsurgical pain, however, a direct comparison between the two main modalities used, conventional and cooled, is lacking.

METHODS

This double blind, non-inferiority, pilot, randomized controlled trial compared the effects of cooled and conventional RF in chronic knee pain patients suffering from osteoarthritis or persistent postsurgical pain after total knee arthroplasty. Patients were randomized following a 1:1 rate. The primary outcome was the proportion of patients with ≥50% pain reduction at 3 months postintervention. Other outcomes were knee pain, functionality, quality of life, emotional health, and adverse events up to 6 months postintervention. Conventional RF treatment was tested for non-inferiority to cooled in reducing knee pain at 3 months follow-up.

RESULTS

Forty-nine of 70 patients were included, of which 47 completed a 3-month follow-up. The primary outcome was achieved in 4 of 23 patients treated with conventional RF (17%) vs in 8 of 24 with cooled (33%) (p=0,21). Results from the non-inferiority comparison were inconclusive in relation to the non-inferiority margin. There was no statistically significant difference between secondary outcomes. There were no serious adverse events.

CONCLUSIONS

Both conventional and cooled RF treatment reduced pain in the osteoarthritis and persistent postsurgical pain population. This pilot study did not demonstrate statistically significant differences in the proportion of patients experiencing ≥50% pain reduction between techniques. The non-inferiority analysis was inconclusive. These results warrant further research.

TRIAL REGISTRATION NUMBER

NCT03865849.

An Update on Physical Therapy Adjuncts in Orthopedics

Physical therapy is a necessary part of the recovery process after most orthopedic procedures. Effective treatment, patient satisfaction, and financial reimbursement hinge on the successful implementation of both surgical and nonsurgical interventions. Evidence-based practice and open communication between therapists and orthopedic surgeons continue to form the foundation of patient care. The aim of this paper is to familiarize orthopedic surgeons with the relevant data behind some of the recent advances in rehabilitation adjuncts to better address the needs of our patients. Although each intervention has been found to be relatively safe, high-quality evidence is still sparse. Opportunities exist for improved outcomes with further well-designed studies to investigate the role of these therapy modalities among orthopedic patients.

Total Knee Arthroplasty Complicated by Posterior Dislocation of a Polyethylene Insert and Neurovascular Compromise

Dislocation of the polyethylene insert is a rare complication of total knee arthroplasty (TKA), which has only been described in a handful of case reports. Here, we describe a report of a 55-year-old woman presenting 13 months after the primary TKA with signs of neurovascular compromise. A magnetic resonance image showed posterior extrusion of her polyethylene insert causing a mass effect on the gastrocnemius muscle and the popliteal neurovascular bundle. A multidisciplinary team including a joint reconstruction surgeon, vascular surgeon, and nerve specialist performed a revision TKA with peroneal nerve decompression. The polyethylene insert was noted to be dislocated, rotated 90 degrees, and incarcerated in the posterior knee.

Safety and Efficacy of Genicular Nerve Radiofrequency Ablation for Management of Painful Total Knee Replacement: A Systematic Review

Painful total knee replacement (TKR) without an obvious underlying identifiable pathology is not uncommon. Dissatisfaction after TKR can be up to 20%. Different treatment modalities, including non-operative and operative procedures, have been described in the literature. Radiofrequency ablation of genicular nerves (GNRFA) is emerging as a newer treatment modality for painful TKR without an obvious underlying identifiable pathology. Despite a modest number of publications demonstrating the usefulness of GNRFA in managing pain in knee osteoarthritis, the efficacy of GNRFA has not been completely established in the management of residual pain after TKR. This systematic review aimed to analyze all published studies (nine studies) on GNRFA as an option to manage residual pain after TKR. Based on this current systematic review, we noted that GNRFA is a modality to treat post residual pain and patients can anticipate improvement in pain up to three months with minimal complications. This article provides an overview of the currently available knowledge and techniques employed for this procedure, as well as the expected outcome and safety profile of GNRFA in painful TKR.

Intra-Articular Corticosteroid Injection After Total Knee Replacement: Is it Safe?

Recalcitrant pain after total knee replacement (TKR) is sometimes treated with intra-articular steroid injections (IASI), with few studies reporting on the risk of subsequent periprosthetic joint infection (PJI). This is a systematic review to evaluate the incidence and risk of PJI after IASI into a total knee replacement.

We searched online databases using the keywords "total knee replacement," "total knee arthroplasty," "steroids" and "intra-articular injection." A total of 7386 articles (PubMed - 91, Embase - 70, Web of Science - 57, CINAHL - 8, and Google Scholar - 7160) were retrieved on the initial search. After applying exclusion criteria, four articles were included in this review for evaluation and statistical analysis. There were no level one or two studies.

The incidence of infection after IASI at 12 months was 138/6499 or 2.1%, while the incidence of infection rate among controls at 12 months was 158/11256 or 1.4%. A chi-square test showed that the difference in infection rate was significant (p = 0.0002424). A caveat is that simple statistical test results are virtually guaranteed to be statistically significant with large sample size.

IASI into a TKR is not a benign procedure and that may be associated with a significantly increased risk of subsequent periprosthetic joint infection. We, therefore, recommend against IASI into a TKR until better studies can be performed to determine their safety and efficacy.

Effects of Trigger Point Dry Needling for the Management of Knee Pain Syndromes: A Systematic Review and Meta-Analysis

Background: To evaluate the effect of trigger point dry needling alone or as an adjunct with other interventions on pain and related disability in people with knee pain. Methods: Several electronic databases were searched for randomized controlled trials where at least one group received dry needling for knee pain. Studies had to include human subjects and collect outcomes on pain and pain-related disability in musculoskeletal knee pain. Data were extracted by two reviewers. The risk of bias was assessed by the Cochrane Guidelines, methodological quality was assessed with the Physiotherapy Evidence Database (PEDro) score, and the quality of evidence by using the GRADE approach. Standardized mean differences (SMD) were calculated. Results: Ten studies (six patellofemoral pain, two knee osteoarthritis, two post-surgery knee pain) were included. The meta-analysis found moderate effect sizes of dry needling for reducing pain (SMD −0.53, 95% CI −0.87 to −0.19) and improving related disability (SMD −0.58, 95% CI −1.08 to −0.09) as compared to a comparison group at short-term. The main effect was observed for patellofemoral pain (SMD −0.64, 95% CI −1.17 to −0.11). No significant effects were observed at mid- or long-term follow-ups. The risk of bias was generally low, but the heterogenicity and the imprecision of the results downgraded the level of evidence. Conclusion: Low to moderate evidence suggests a positive effect of trigger point dry needling on pain and related disability in patellofemoral pain, but not knee osteoarthritis or post-surgery knee pain, at short-term. More high-quality trials investigating long-term effects are clearly needed.