Archive | January 2019

Full-Thickness Cartilage Defects More Predictive of Future TKA than Joint-Space Narrowing

Many older patients present to orthopaedic surgeons with clinical knee pain suggestive of osteoarthritis (OA) but with little or no radiographic evidence of disease. And a substantial proportion of those patients do not respond adequately to the recommended, first-line nonsurgical treatment approaches to knee OA. A prognostic study by Everhart et al. in the January 2, 2019 issue of The Journal of Bone & Joint Surgery helps explain why that might be.

The authors evaluated baseline knee radiographs and MRIs from >1,300 older adults (mean age of 61 years) who were enrolled in the Osteoarthritis Initiative, a multicenter observational cohort study with a median of 9 years of follow-up data. They sought to determine independent risk factors for progression to total knee arthroplasty (TKA) among this cohort, all of whom showed Kellgren-Lawrence grade 0 to 3 OA on knee radiographs. MRIs taken at baseline revealed that 38% of those patients had a full-thickness knee-cartilage defect. After the authors adjusted for various confounders (including age, weight, and symptom severity), they found that regardless of radiographic grade, the presence of a full-thickness cartilage defect was a strong independent risk factor for subsequent TKA. Moreover, patients with a defect ≥2 cm2 had twice the risk of arthroplasty compared with patients with defects <2 cm2.

According to the authors, the findings highlight the “greater importance of full-thickness cartilage loss over radiographic OA grade as a determinant of OA severity, specifically regarding the risk of future knee arthroplasty in older adults.” In his commentary on this study, Drew A. Lansdown, MD emphasizes that Everhart et al. “do not advocate for the routine use of MRI in the diagnosis of knee osteoarthritis,” but he says the findings “do suggest that early MRI may have a diagnostic role for patients who are not responding as expected to nonoperative measures.” Noting that the patients in this cohort would probably not be ideal candidates for current cartilage-restoration procedures, Dr. Lansdown encourages further research focused on identifying “patient-specific factors that can match patients with the treatment…that will provide the greatest likelihood of symptom relief and functional improvement.”

Unexplained Pain After TKA? Duloxetine Might Help

Somewhere between 10% and 15% of patients are unsatisfied with their outcome after primary total knee arthroplasty (TKA). In some cases, dissatisfaction is related to poor range of motion, but more often it is related to residual—or even intensified—pain in the knee several weeks after surgery.

In the January 2, 2019 issue of The Journal, Koh et al. report the results of a prospective randomized trial assessing the effects of duloxetine (Cymbalta) in TKA patients who were screened preoperatively for “central sensitization.” In central sensitization, a hyperexcitable central nervous system becomes hypersensitive to stimuli, noxious and otherwise.

Koh et al. randomized 80 centrally sensitized patients (mean age of 69 years), 40 of whom received a multimodal perioperative pain management protocol plus duloxetine, and 40 of whom received the multimodal protocol without duloxetine. During postoperative weeks 2 through 12, patients taking duloxetine reported better results in terms of pain and functional and emotional outcome measures than those not receiving the drug. Patients in the duloxetine group expressed greater satisfaction with pain control (77% vs 29%) and daily activity (83% vs 52%) at postoperative week 12, compared with those in the control group.

This research represents an important advance in identifying and treating patients who are prone to poor outcomes after TKA. The concept of central sensitization is relatively new to the orthopaedic community, and this pharmacologic intervention is likely to be just the first among many that will help these patients. I think it is probable that other, nonpharmacological interventions will eventually be as or even more successful in helping TKA patients with central sensitization. Koh et al. make a valuable  contribution in this article by educating us as to the neurophysiologic basis of this condition, and their work should pave the way for more important research in this area.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Self-Reported Marijuana Use Is Associated with Increased Use of Prescription Opioids Following Traumatic Musculoskeletal Injury

Full Article
Cannabinoids are among the psychoactive substances considered as alternatives to opioids for the alleviation of acute pain. We examined whether self-reported marijuana use was associated with decreased use of prescription opioids following traumatic musculoskeletal injury.

Complications Following Overlapping Orthopaedic Procedures at an Ambulatory Surgery Center

Full Article
Overlapping surgery occurs when a single surgeon is the primary surgeon for >1 patient in separate operating rooms simultaneously. The surgeon is present for the critical portions of each patient’s operation although not present for the entirety of the case. While overlapping surgery has been widely utilized across surgical subspecialties, few large studies have compared the safety of overlapping and nonoverlapping orthopaedic surgery.