Published 4/1/2016

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)

Compartment syndrome—A study published in the Journal of Orthopaedic Trauma (online) attempts to identify radiographic indicators linked to compartment syndrome after tibial fracture. The research team conducted a retrospective review of 978 consecutive adult patients with tibial fracture, 56 of whom had compartment syndrome. They found that the likelihood of compartment syndrome increased by 1.67 per 10 percent increase in the ratio of fracture length to tibial length. In addition, the research team noted that compartment syndrome was most likely to occur with plateau fractures and that compartment syndrome was more likely to develop in Schatzker VI fractures than in any other Schatzker type. Finally, they found that fibular fracture was predictive of compartment syndrome with plateau fractures only and that compartment syndrome was not more likely to develop in segmental fractures than in other shaft fractures.

Ankle—Information published in Foot & Ankle International (online) examines factors linked to postoperative wound necrosis following primary wound closure of open malleolar ankle fracture. The authors reviewed data on 110 patients with open malleolar ankle fractures and found that postoperative wound necrosis occurred in 16 percent (n = 18) of patients. Of those, variables that were independently associated with an increased risk for postoperative wound necrosis included American Society of Anesthesiologists (ASA) class ≥2, Gustilo grade III open injury, and the use of pulsatile lavage at index surgery.

Data from a study published in The American Journal of Sports Medicine (AJSM; March) suggest that intra-articular injections of platelet-rich plasma (PRP) may offer significant clinical improvement in patients with hip osteoarthritis (OA). The authors conducted a randomized, controlled trial of 111 adults aged 18 to 65 years, with hip OA and baseline pain intensity of >20 on a 100-mm visual analog scale (VAS). Patients were assigned to one of three groups: 3 weekly injections of PRP (n = 44), PRP + hyaluronic acid (HA; n = 31), or HA (n = 36). At 2-, 6-, and 12-month follow-up, patients in the PRP cohort had the lowest VAS scores. In addition, Western Ontario and McMaster Universities arthritis index was significantly better among PRP patients compared to other cohorts at 2- and 6-month follow-ups, but not at 12-month follow-up. The authors note that the addition of PRP+HA did not lead to a significant improvement in pain symptoms.

ACL reconstruction (OA)—
A study published in AJSM (online) examines changes in knee OA symptoms and function after anterior cruciate ligament (ACL) reconstruction. The authors conducted a prospective, cohort study of 210 patients who underwent ACL reconstruction, with 168 available at 20-year follow-up. At 20 years, the authors noted that 42 percent of patients had radiographic tibiofemoral OA and 21 percent had radiographic patellofemoral OA. Overall, patients with ACL injuries and other combined injuries were at significantly increased risk of radiographic tibiofemoral OA, compared with those who had an isolated ACL injury. The authors noted a 13 percent increase in radiographic tibiofemoral OA and an 8 percent increase in patellofemoral OA from the 15- to the 20-year follow-up. With the exception of quality of life, they observed a significant deterioration in knee symptoms and function on the Knee Injury and Osteoarthritis Outcome Score subscales and also a decrease in quadriceps muscle strength and hamstring muscle strength.

ACL reconstruction (allograft)—Data from Paper 02 presented at the Specialty Day meeting of the American Orthopaedic Society for Sports Medicine suggest that use of bone-patellar tendon-bone (BPTB) autograft tissue in ACL reconstruction may decrease risk of revision compared to soft-tissue allograft. The researchers reviewed 14,105 patients who had undergone ACL reconstruction using BPTB autograft, hamstring autograft, or soft-tissue allograft. At 3-year follow-up, they found that overall revision rates were 2.5 percent for BPTB, 3.5 percent for hamstring autografts, and 3.7 percent for soft-tissue allografts. In addition, the researchers found that, compared to BPTB autograft, allografts processed with more than 1.8 Mrads irradiation and grafts processed with more than 1.8 Mrads or high pressure chemical processing were at increased risk of revision.

Femoral nerve block—A study published in Clinical Orthopaedics and Related Research (online) compares the use of femoral nerve blocks (FNBs) and periarticular infiltration of liposomal bupivacaine for pain management after total knee arthroplasty (TKA). The research team conducted a retrospective analysis of 1,110 unilateral, primary TKAs performed by 24 surgeons and compared 583 patients treated with an ultrasound-guided FNB against 527 patients treated with liposomal bupivacaine. They found no clinically important difference in pain scores throughout the hospital stay, but noted that patients treated with liposomal bupivacaine consumed very slightly fewer narcotics overall through postoperative day 2 of inpatient hospitalization. Overall, 77 percent (406 of 527) of patients who received liposomal bupivacaine cleared 100 feet of ambulation before discharge, compared to 60 percent (349 of 583) of patients who received FNB. In addition, 94 percent (497 of 527) of patients in the bupivacaine cohort completed stairs, compared with 73 percent (427 of 583) of those in the FNB cohort. Patients who received liposomal bupivacaine were also less likely to experience a fall during the hospital stay than patients treated with FNB.

Meniscus—According to data from a study conducted in Finland and published in the Annals of Internal Medicine (online), resection of a torn meniscus may offer little benefit over sham surgery for the relief of knee catching or occasional locking. The researchers conducted a randomized, double-blind, controlled study of 146 patients who underwent either arthroscopic partial meniscectomy (APM; n = 70) or sham surgery (n = 76). Overall, 32 patients (46 percent) in the APM group and 37 (49 percent) in the sham surgery group reported catching or locking prior to surgery. At 2-, 6-, and 12-month follow-ups, the researchers found that 34 (49 percent) patients in the AMP and 33 (43 percent) in the sham group reported catching or locking, for a risk difference of 0.03. In the subgroup of 69 patients with preoperative catching or locking, the risk difference was 0.07. The researchers state that the study results are only generalizable to knee catching and occasional locking, as few patients reported other mechanical symptoms.

Findings published in Spine (February) suggest that wearing a brace may not negatively impact body image or quality of life (QOL) for female adolescent idiopathic scoliosis (AIS) patients with moderate curve sizes (20°–40°). The research team drew data on 319 participants in the Bracing in Adolescent Idiopathic Scoliosis Trial, 132 of whom participated in a randomized treatment arm and 187 in a preference treatment arm, with 199 brace-treated and 120 observed. Through 2-year follow-up, the research team noted no significant difference between study arms or treatments regarding body image or QOL, based on the Spinal Appearance Questionnaire and the Pediatric Quality of Life Inventory 4.0 Generic Scales. Overall, poorer body image was significantly correlated with poorer QOL regardless of study arm or treatment. The research team found that patients who crossed over to a different treatment and patients with Cobb angles ≥40° had significantly poorer body image, in particular self-body image, compared with those that did not.

Patient safety
The Washington Post reports that 41 signatories from various governmental health departments and universities have petitioned the U.S. Food and Drug Administration (FDA) to add a "black box" warning to opioids and benzodiazepines regarding potential dangers of taking such drugs in combination. The petitioners argue that taking the two types of drugs together can severely depress the respiratory system, and they request that an FDA warning state that taking the drugs in combination "reduces the margin of safety for respiratory depression and contributes to the risk of fatal overdose, particularly in the setting of misuse."

EHRs—A study published in the Journal of Patient Safety (online) suggests that use of electronic health records (EHR) systems may improve safety for surgical patients. The research team conducted a retrospective analysis of patient discharges using data from the 2012 and 2013 Medicare Patient Safety Monitoring System. The sample included patients age 18 years and older who were hospitalized for acute cardiovascular disease, pneumonia, or conditions requiring surgery. Overall, they found that the occurrence rate of adverse events was 2.3 percent, and 13.0 percent of patients were exposed to a fully electronic EHR. After adjustment, they noted that patient exposure to a fully electronic EHR was associated with 17 percent to 30 percent reduced odds of any adverse event.

VTE risk—Data from a study published in Blood (online) suggest that common genetic variants predominantly found in African Americans may increase the risk of venous thromboembolism (VTE). The researchers note that African Americans have been found to be at 30 percent to 60 percent increased risk of VTE compared to other ethnicities. They conducted a genome-wide association study of 578 African-American participants followed by replication of highly significant findings in an independent cohort of 159 African-American subjects. The researchers identified and replicated single-nucleotide polymorphisms (SNPs) on chromosome 20 (rs2144940, rs2567617, and rs1998081) that increased risk of VTE by 2.3-fold. The risk variants occurred more frequently among populations of African descent compared to other ethnic groups.

Skull clamps—FDA has issued a safety communication regarding neurosurgical head holder (skull clamp) systems. Between January 2009 and January 2016, the agency received more than 1,000 medical device reports associated with slippage or movement of a skull clamp before and/or during surgical procedures, resulting in more than 700 injuries. The reports describe unintended patient movement during surgical procedures that resulted in injuries including skull fractures, facial injuries, lacerations, and hematoma. Additionally, unintended patient movement has compromised procedures dependent upon head immobilization, causing inaccurate stereotaxic navigation and delayed, prolonged, or halted surgical procedures. An FDA review of medical literature and analysis of currently available data suggests that device slippage is not specific to any manufacturer or brand of device. The causes of skull clamps slipping before and/or during surgical procedures are multifactorial and may include device performance, device application, patient-specific characteristics, and lack of maintenance. The agency states that some risks can be mitigated through device placement considerations, proper use, and proper device maintenance.

ADHD medications—Research presented at the AAOS Annual Meeting suggests that children and adolescents treated with psychotropic drugs for attention deficit hyperactivity disorder (ADHD) may be at risk for reduced bone mineral density (BMD). The authors reviewed data on 5,315 patients aged 8 to 17 years whose bone health was measured using dual-energy x-ray absorptiometry scans. They conservatively estimated that the difference in standardized BMD measures between the ADHD medication group and the nonmedicated group ranged from -0.4855 for total femoral, -0.4671 for femoral neck, and -0.3947 for lumbar.

Shoulder and elbow
A study published in the Journal of Shoulder and Elbow Surgery (online) examines the efficacy of AAOS appropriate use criteria (AUC) in determining the appropriateness of treatment options for full-thickness rotator cuff tears (RCTs). The researchers entered information on 134 patients with full-thickness RCTs into the AAOS web-based AUC application and compared with actual treatments and outcomes at 32- and 48-week follow-ups. They noted excellent agreement between AAOS AUC recommendations and actual treatment administered, with administered treatment considered "appropriate" for 79 percent of patients, "may be appropriate" for 19 percent, and "rarely appropriate" for 2 percent. The researchers found that response to previous treatment, ASA Physical Status Classification, and presence of muscle atrophy or fatty infiltration were the only variables that significantly and independently predicted discordance between actual treatment and the AUC recommendation.

RCT—Data from a study published in The Journal of Bone & Joint Surgery (Feb. 17) suggest that a patient's mental health may influence patient-reported pain and function among patients with full-thickness RCTs. The researchers conducted a prospective study of 169 patients with full-thickness RCTs. They found that Short Form-36 Mental Component Summary had the strongest correlation with the VAS for shoulder pain and shoulder function, the Simple Shoulder Test, and American Shoulder and Elbow Surgeons score. The researchers note that tear severity only correlated with the VAS for shoulder function and that tear severity did not correlate with other scores in bivariate correlations.

A study published online in The Journal of Bone and Elbow Surgery (online) suggests that patients who undergo reverse total shoulder arthroplasty (RTSA) may be more likely to return to sports than those who undergo hemiarthroplasty (HA). The authors conducted a retrospective review of 102 RTSA and 71 HA patients at a single center. Average patient age at surgery was 72.3 years for RTSA and 65.6 years for HA. Compared to HA patients, the authors found that at minimum 1-year follow-up, patients who underwent RTSA had improved VAS scores, returned to sports at a significantly higher rate, and were more likely to be satisfied with their ability to play sports. The authors also noted that HA patients were more likely to have postoperative complaints compared to RTSA patients. Overall, female sex, age <70 years, surgery on the dominant extremity, and a preoperative diagnosis of arthritis with rotator cuff dysfunction were predictors of a higher likelihood of return to sports for patients undergoing rtsa compared with those undergoing ha.>

ACL—Data from Scientific Poster P434, presented at the 2016 AAOS Annual Meeting, suggest that female soccer players who undergo ACL reconstruction and return to sport may be at increased risk of graft re-tear and contralateral ACL injury than female athletes who do not play soccer. The researchers reviewed data on 180 patients (90 soccer players and 90 non–soccer players) who underwent primary ACL reconstruction following an athletic-related injury. At mean 5.8-year follow-up, they found that soccer players had more second ACL injuries, including both graft failures (11 percent vs. 1 percent) and contralateral ACL tears (17 percent vs. 4 percent), compared to athletes who did not play soccer.

Concussion—Findings presented at the annual meeting of the Association of Academic Physiatrists suggest that native language could affect performance on a sideline concussion screening test. The research team tracked eye movements of 54 individuals given the King-Devick concussion screening test, 27 of whom were native English speakers and 27 for whom English was a second language. They found that nonnative English speakers displayed significantly slower response times compared to native English speakers. The research team states that ideally, preseason baselines should be established for all athletes to help account for performance changes, but argues that language "should be considered and factored into the interpretation."