Published 4/1/2018

Second Look – Clinical News and Views

These items originally appeared in AAOS Headline News Now, a thrice-weekly enewsletter that keeps AAOS members up to date on clinical, socioeconomic, and political issues, with links to more detailed information. Subscribe at www.aaos.org/news/news.asp (member login required).

Patient safety
VTE risk—
Findings in the Journal of the AAOS (JAAOS; Feb. 15) suggest that rapid increase in international normalized ratio (INR) after warfarin initiation may be associated with increased risk of venous thromboembolism (VTE) in patients who undergo total joint arthroplasty (TJA). Members of the research team conducted a retrospective study of 948 patients (715 total knee arthroplasty [TKA], 233 total hip arthroplasty [THA]), of whom 4.4 percent experienced symptomatic VTE within 30 days postoperatively. They found that change in INR from postoperative day one to postoperative day two was significantly greater among patients with symptomatic VTE compared to those without VTE. The researchers argue that further research should be conducted into the early effects of warfarin therapy.

Aspirin and VTE—Data from a study published in The New England Journal of Medicine (Feb. 22) suggest that extended prophylaxis with aspirin may not significantly differ from rivaroxaban for the prevention of symptomatic VTE following primary TJA. The authors conducted a multicenter, double-blind, randomized, controlled trial of 3,424 patients (THA, n = 1,804; TKA, n = 1,620). All patients received once-daily oral rivaroxaban (10 mg) until postoperative day 5 and then were randomly assigned to continue rivaroxaban or switch to aspirin (81 mg daily) for an additional 30 days after THA or for 9 days after TKA. After 90 days, they found that VTE had occurred in 11 of 1,707 patients (0.64 percent) in the aspirin group and in 12 of 1,717 patients (0.70 percent) in the rivaroxaban group, while major bleeding complications had occurred in eight patients (0.47 percent) in the aspirin group and five patients (0.29 percent) in the rivaroxaban group. Further, clinically important bleeding occurred in 22 patients (1.29 percent) in the aspirin group and in 17 patients (0.99 percent) in the rivaroxaban group.

OR sterile field—A study published in JAAOS (March 1) suggests that single door opening may not defeat positive pressure in the operating room (OR), but simultaneous opening of two doors may allow contaminated air to enter. The researchers used digital manometers to collect pressure data during off-hours at the thresholds of both the outer and the inner substerile doors for six empty ORs used for TJA. They found that positive pressure was not defeated during any door-opening event, and the average time for recovery of initial pressurization regardless of door used was between 14 and 15 seconds. Smoke studies confirmed that no contaminated outside air entered the OR with the opening of a single door. However, outside and potentially contaminated air entered the OR if two doors were open simultaneously.

“Running two rooms”—According to a study in The Journal of Arthroplasty (online), “running two operating rooms” may not compromise patient safety or outcomes for hip or knee arthroplasty procedures. The researchers reviewed information on 16,916 arthroplasties (7,511 THAs and 9,405 TKAs) performed at a single center over an 11-year period. Overall, 7,002 cases (41 percent) were consecutive cases and 9,914 cases (59 percent) were overlapping cases. The researchers found no significant difference across cohorts in 90-day component revision rates or 90-day complication rates.

Smoking and infection—A study published in The Journal of Arthroplasty (online) suggests that smoking may be linked to increased risk of infection following primary hip or knee TJA. The authors conducted a prospective, cohort study of 8,559 primary TJAs (mean patient age: 69.5 years). Overall, 5,722 reported having never smoked, 1,315 had quit smoking, and 1,522 were current smokers. The authors found that incidence rates of infection within the first year for never, former, and current smokers were 4.7, 10.1, and 10.9 cases/1,000 person-years, respectively. Beyond the first year, the authors report that infection risk was similar across cohorts.

In-flight emergencies—An article in the Canadian Medical Association Journal offers some practical recommendations for healthcare professionals who may be called upon to manage in-flight medical emergencies. Among other things, the writers note the following:

  • The cabin environment will affect patients’ vital signs as well as how to measure them reliably.
  • The working environment should be optimized by creating space, turning on the cabin lights, and recruiting additional help.
  • An in-flight medical kit may be available, and providers should contact ground-based telemedicine support early.
  • Open, two-way communication with airline staff should be maintained to ensure the pilots are in a position to make the safest decisions for all passengers.

Falls—A study published in the Journal of Bone and Mineral Research (JBJS; online) suggests that poor functional performance as assessed by the Short Physical Performance Battery (SPPB) test may be an independent predictor of serious injurious falls in patients admitted to a geriatric hospital. The authors conducted a prospective study of 807 patients who were subjected to an array of functional tests administered by physiotherapists within three days of admission, including SPPB, simplified Tinetti, and Timed Up and Go tests. They found that 329 falls occurred in 189 patients (23.4 percent) during a median hospital stay of 23 days. Overall, there were 161 injurious falls, of which 24 were determined to be serious. The authors note that compared with non-fallers, in-hospital fallers displayed significantly poorer functional performance at admission on all tests, but only SPPB significantly predicted serious injurious falls.

Hip and knee
A research letter in JAMA Surgery (online) examines practice patterns for the use of arthroscopic partial meniscectomy (APM) among older patients in the United States. The researchers reviewed Medicare data on 121,624 knee arthroscopy procedures performed by 12,504 surgeons, and found that APM-only (not associated with a ligament, cartilage, or meniscus repair) procedures comprised 66.7 percent of all knee arthroscopies. They state that among 4,138 high-volume surgeons (n = 4,138), 286 (6.9 percent) never performed APM-only procedures and 518 (12.5 percent) exclusively performed APM-only procedures. The researchers note that multiple randomized clinical trials have “revealed no benefit from [APM] in patients with degenerative meniscal tears compared with exercise and physical therapy,” and write that although APM-only procedures may be appropriate for certain patients with an acute traumatic meniscal tear, such injuries typically occur in younger, nonMedicare patients.

ACL rupture—A study published in AJSM (online) examines long-term outcomes for surgical and nonsurgical treatment approaches to anterior cruciate ligament (ACL) rupture in high-level athletes. The authors conduced a retrospective, pair-matched, follow-up study of 50 high-level athletic patients with ACL rupture treated either surgically with an arthroscopic transtibial bone–patellar tendon–bone technique (n = 25) or nonsurgically with structured rehabilitation and lifestyle adjustments (n = 25). At 20-year follow-up, the authors identified knee osteoarthritis (OA) in 80 percent of the surgical cohort and in 68 percent of the nonsurgical cohort. They found no significant difference across cohorts in functional outcomes or meniscectomy performed. However, 21 patients (84 percent) in the surgical group and 5 patients (20 percent) in the nonsurgical group had a normal or near-normal International Knee Documentation Committee score, pivot-shift test finding was negative in 17 patients (68 percent) in the surgical group and three patients (13 percent) in the nonsurgical group, and the Lachman test finding was negative in 12 patients (48 percent) in the surgical group and one patient (4 percent) in the nonsurgical group.

Joint space narrowing—Data published in The American Journal of Sports Medicine (AJSM; online) looks at predictors of radiographic joint space narrowing in younger patients who undergo ACL reconstruction. The authors conducted a prospective, cohort study of 358 patients aged 33 years or younger who received a sports-related ACL injury and who had never undergone surgery on the contralateral knee. At two- to three-year follow-up, they found that the mean lateral joint space width was 0.11 mm narrower on the ACL-reconstructed knee compared to the contralateral healthy knee. Statistically significant predictors of narrower joint space width on the ACL-reconstructed knee included lateral meniscectomy and a Marx activity score of less than 16 points.

Symptomatic knee OA—A study published in AJSM (online) suggests that lower preoperative Knee injury and Osteoarthritis Outcome Score (KOOS) and SF-36 scores may be linked to increased risk of symptomatic knee OA after ACL reconstruction. The researchers conducted a prospective, case-control study of 72 patients who underwent ACL reconstruction. At 7-year follow-up, they determined that seven patients were symptomatic based on KOOS pain ≤ 72. In multivariate analysis, they found that lower preoperative scores for KOOS sports/recreation and SF-36 mental health were associated with a painful knee, with increased likelihood of 82 percent and 68 percent per 10-unit decrease, respectively. The researchers noted no significant difference in Osteoarthritis Research Society International radiographic score or joint space width between symptomatic and asymptomatic patients.

Joint laxity—According to a study in JBJS (Feb. 21), generalized joint laxity may have an adverse effect on stability and functional outcomes for patients undergoing ACL reconstruction. Members of the research team conducted a retrospective review of 163 patients who underwent unilateral ACL reconstruction. They found an increased likelihood of meniscectomy, graft rupture, and contralateral ACL rupture among a cohort of patients with generalized joint laxity, although differences in proportions and cumulative rupture rates did not reach significance. However, at eight-year follow-up, the researchers found that patients with generalized joint laxity displayed less stability and poorer functional outcomes. “Generalized joint laxity should be considered a risk factor for poor outcomes after ACL reconstruction,” the researchers write.

Pain-related responses—Findings published in Clinical Orthopaedics and Related Research (online) suggest that surgeons should consider certain pain-related responses when assessing patients prior to TKA. The authors conducted a cross-sectional analysis of 384 TKA patients with moderate to high levels of pain catastrophizing. They found that higher guarding scores and higher pain catastrophizing were associated with worse Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, while no adaptive responses were associated with improved WOMAC pain or physical performance scores. The authors note that maladaptive responses were also more consistently associated with worse self-reported and performance-based measure scores, but adaptive responses did not associate with better scores. “Future intervention-based research should target this trio of maladaptive pain responses to determine if intervention leads to improvements in postsurgical health outcomes,” the authors write.

Cam lesion—Findings published in JBJS (Feb. 7) suggest that cam lesion may have a greater impact on hip flexion range of motion (ROM) than on hip internal rotation. The authors conducted a prospective, cohort study of 220 patients (440 hips) who presented with unilateral or bilateral hip pain. They found that femoral version was a stronger independent predictor than cam lesion of internal rotation ROM. Conversely, the presence of a cam lesion was associated with a significant decrease in the passive hip flexion ROM, with no additional effects linked to degree of femoral version. The authors note that passive hip internal rotation ROM in neutral flexion/extension and with the hip in 90° of flexion were maximized among patients with femoral anteversion, and decreased significantly with each incremental decrease in femoral version.

FAI—A study published in AJSM (online) compares arthroscopic surgery to nonsurgical management for femoroacetabular impingement (FAI). The authors conducted a randomized, controlled trial of 80 patients aged 18 to 60 years, of whom 73 (91.3 percent) were active-duty members of the military. Patients in the rehabilitation cohort were treated with a 12-session physical therapy (PT) program within three weeks of enrollment in the study, while patients in the surgical cohort underwent surgery at a mean four months after enrollment. At two-year follow-up, the authors noted statistically significant improvement in both groups in Hip Outcome Score and International Hip Outcome Tool, but the mean difference was not significant across cohorts. Two patients assigned to the surgery group did not undergo surgery and 28 patients in the rehabilitation group ended up undergoing surgery. However, a sensitivity analysis of “actual surgery” to “no surgery” did not change the outcome.

Shoulder and elbow
Rotator cuff repair—
Findings in AJSM (online) suggest that treatment with platelet-rich plasma (PRP) may be linked to improved outcomes for rotator cuff repair. The researchers conducted a meta-analysis of 18 randomized, controlled trials covering 1,147 patients. Compared to controls, they found that use of PRP was associated with significantly decreased rates of incomplete tendon healing for all tears combined, incomplete tendon healing in small-medium tears, and incomplete tendon healing in medium-large tears. In addition, at 30-day follow-up, the researchers found that PRP was linked to significant improvements in Constant score and visual analog scale (VAS) score for pain compared to controls. However, the researchers write that use of platelet-rich fibrin (PRF) was not linked to similar improvements, and was associated with significantly longer surgical times.

Recurrent anterior shoulder instability—According to a study in AJSM (online), fresh distal tibia allograft (DTA) reconstruction and the Latarjet procedure may offer similar outcomes for recurrent anterior shoulder instability. The researchers conducted a prospective, matched cohort study of 100 patients who underwent shoulder stabilization, 50 of whom were treated with DTA and 50 of whom were treated with Latarjet. At minimum two-year follow-up (range: 24 to 111 months), they found that patients in both cohorts experienced significant improvement in all outcome scores after surgery. The researchers found no significant differences across cohort in postoperative VAS, American Shoulder and Elbow Surgeons, Western Ontario Shoulder Instability Index, or Single Assessment Numeric Evaluation scores. They note, however, that patients in the Latarjet group had superior Simple Shoulder Test outcomes. There were five complications, three of which required reoperation, in each cohort.

Foot and ankle
Achilles tendon rupture—
A study published in Foot and Ankle International (online) suggests that male sex may be associated with increased risk of rerupture and failure of nonsurgical treatment of acute Achilles tendon rupture. The researchers retrospectively reviewed information on 210 patients diagnosed with acute Achilles tendon rupture and who underwent eight weeks of nonsurgical treatment with functional rehabilitation. They found that 15 patients sustained a rerupture and six patients otherwise failed treatment. The researchers write that male sex was associated with both rerupture and failed nonsurgical treatment for any reason.

A study in The Spine Journal (January) suggests that American Society of Anesthesiologists (ASA) physical status classification and patient age may help identify risk of perioperative adverse outcomes following posterior lumbar fusion (PLF) as well as other, more difficult to implement indices. The authors reviewed prospectively collected data on 16,495 patients who underwent elective PLF and compared the discriminative ability of ASA, modified Charlson Comorbidity Index, and modified Frailty Index, as well as demographic factors including age, body mass index, and gender for perioperative adverse outcomes following PLF. They found that the most predictive comorbidity index was ASA and the most predictive demographic factor was age. Of those, age was most discriminative for three out of six adverse outcomes, and ASA was the most predictive for one out of six adverse outcomes. The authors write that the combination of ASA and age “resulted in improvements in discriminative ability over the individual components for five of the six outcome variables.

Hyperkyphosis—According to a study in Menopause (online), menopausal hormone therapy (HT) may help reduce risk of hyperkyphosis in elderly women. The authors reviewed data on 1,063 women (mean age: 83.7 years) participating in the Study of Osteoporotic Fractures. They found that 46 percent of participants were characterized as never users of HT, 24 percent remote past users, 17 percent intermittent users, and 12 percent continuous users. After adjustment, the authors found that the mean Cobb angle was 2.8° less in continuous and remote past HT users compared with never users, while intermittent users did not differ from never users in degree of kyphosis.

Delayed surgery—
A study in the Journal of Orthopaedic Trauma (JOT; March) suggests that early surgery may be linked to reduced risk of mortality for older hip fracture patients. The researchers reviewed data on 720 hip fracture surgery patients aged 66 years or older and found that 159 (22 percent) died within one year. They noted a linear relationship between surgical timing and one-year mortality: Each 10-hour delay in surgery was significantly associated with a five percent increase in one-year mortality. The researchers suggest that hip fractures be treated urgently in a manner similar to other time-sensitive pathologies such as stroke and myocardial ischemia.

Unstable intertrochanteric hip fracture—Findings from a study published in JOT (February) suggest that use of a cephalomedullary nail (CMN) for treatment of unstable intertrochanteric hip fractures may offer improved outcomes compared to sliding hip screw (SHS) with or without a trochanteric stabilization plate (TSP). Members of the research team reviewed prospectively collected data on 3,230 patients who met inclusion criteria. Among them, 2,474 patients were treated with SHS, 158 patients were treated with SHS plus TSP, and 598 patients were treated with CMN. At 12-month follow-up, the researchers found no significant difference across cohorts in functional outcome. However, patients treated with CMN displayed significantly lower 12-month mortality rates, and the highest revision rate was seen among patients treated with SHS alone.