Published 5/1/2016

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)

Shoulder and elbow
UCL reconstruction—
A study published in The American Journal of Sports Medicine (AJSM, March) suggests increasing use of ulnar collateral ligament (UCL) reconstruction over a 10-year period. The authors used the New York Statewide Planning and Research Cooperative System database to identify all UCL reconstructions in New York State from 2002 to 2011. They found that the volume of UCL reconstructions increased by 193 percent during the study period, and the rate per 100,000 population tripled from 0.15 to 0.45. The mean patient age was 21.6 years, and the authors noted a significant increasing trend for UCL reconstruction in patients aged 17 to 18 and 19 to 20 years. In addition, they found a 400 percent increase in concomitant ulnar nerve release/transpositions performed during the study period, representing a significant increase in the frequency of ulnar nerve procedures at the time of UCL reconstruction. The authors argue for an increased educational emphasis on the risks of overuse and throwing injuries and the importance of adhering to preventive guidelines.

RTSA—According to a study published in the Journal of Shoulder and Elbow Surgery (online), reverse total shoulder arthroplasty (RTSA) may be a cost-effective intervention in the surgical treatment of complex proximal humerus fractures. The researchers developed a Markov model to compare the cost-effectiveness of nonsurgical fracture care, hemiarthroplasty (HA), and RTSA for complex proximal humerus fractures. They found that from a payer perspective, RTSA was associated with an incremental cost-effectiveness ratio (ICER) of $8,100/quality-adjusted life-year (QALY); HA was eliminated from payer analysis as a cost-ineffective strategy. However, the researchers noted that HA was cost-effective from a hospital perspective, with the ICER being $36,700/QALY, and RTSA providing incremental effectiveness at $57,400/QALY. Overall, the researchers noted that RTSA was the optimal strategy in 61 percent and 54 percent of payer and hospital probabilistic sensitivity analyses, respectively.

Hip and knee
ACL reconstruction—
Findings from a study published in AJSM (online) suggest that anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction may not be superior to anatomic single-bundle (SB) ACL reconstruction. The authors conducted a randomized, controlled trial of 105 patients aged 18 to 52 years who underwent ACL reconstruction using the DB (n = 53) or SB (n = 52) technique. Preoperatively, no differences were found between cohorts, apart from preinjury Tegner activity level, which was lower in the DB group. At 5-year follow-up of 87 patients, the authors found no statistical differences between cohorts in terms of the pivot-shift test, KT-1000 arthrometer laxity measurements, manual Lachman test, single-legged-hop test, square-hop test, range of motion, Lysholm knee scoring scale, Tegner activity scale, or Knee injury and Osteoarthritis Outcome Score. However, they noted a significant increase of osteoarthritis (OA) within the DB group at 5-year follow-up.

ACL tensioning—Data from a study published in AJSM (online) suggest that measured tensioning of hamstring ACL grafts may not improve clinical outcomes, compared to conventional tensioning. The authors conducted a randomized, controlled trial of 113 patients undergoing primary ACL reconstruction; 55 patients were treated using a measured tensioning device for graft tensioning, and 58 patients were treated with conventional tensioning maneuvers. At baseline and 6-, 12-, and 18-month follow-ups, the authors found no significant differences between cohorts in side-to-side laxity or International Knee Documentation Committee Subjective Knee Evaluation Form and ACL Quality of Life Questionnaire scores.

Novel ACL technique—An article in The New York Times reports on an experimental ACL reconstruction technique performed by physicians at a single center. The research team conducted a pilot safety trial of 20 patients; 10 patients underwent standard ACL reconstruction and 10 patients were treated using bridge-enhanced ACL repair. At maximum 1-year follow-up, the team found no failed repairs, infections, or stiffness among patients in either cohort. Based on its findings, the research team plans to move forward with a larger, randomized trial.

Knee OA—Data from a study conducted in Finland and published in Nature (online) suggest that an algorithm combined with computational modeling may be used to simulate the development of knee OA. The researchers drew baseline data from 1,087 participants in the Osteoarthritis Initiative database and developed a cartilage degeneration algorithm to simulate knee OA progression among overweight patients. At 4-year follow-up, they compared representative subjects from two matched cohorts of patients younger than 65 years: mean body mass index (BMI) 24 kg/m2 and no meniscus or knee injuries, and mean BMI 35 kg/m2 and no meniscus or knee injuries). The algorithm accurately simulated cartilage degeneration as compared to the Kellgren-Lawrence (KL) findings in the high-BMI cohort, while the healthy subject group's joints remained intact. In addition, the algorithm followed the experimentally found trend of cartilage degeneration in the obese group, in which rapid degeneration immediately after initiation of OA was followed by slow or negligible degeneration.

Femoral neck fracture—A study published in Clinical Orthopaedics and Related Research (CORR, May) suggests that treatment with teriparatide may not decrease risk of revision surgery, improve radiographic signs of fracture healing, or decrease pain, compared to placebo for patients with femoral neck fracture. The authors conducted a prospective, randomized, double-blind, placebo-controlled trial of 157 patients treated with either subcutaneous teriparatide (20 µg/day; n = 78) or placebo (n = 79) for 6 months. At 12-month follow-up, they found no significant difference between cohorts in proportion of patients who underwent revision surgery, proportion of patients who achieved radiographic fracture healing, or in measures of pain control. During the 6-month treatment period, 49 percent of patients in the placebo group reported adverse events, compared to 45 percent in the teriparatide group.

BCR implants—Data from a short-term study published in CORR (online) suggest that bicruciate-retaining (BCR) implants may be associated with reduced survivorship, compared to conventional cruciate-retaining (CR) implants for total knee arthroplasty (TKA). The researchers conducted a therapeutic study of 475 primary TKAs performed by two surgeons. Overall, there were 78 procedures (16 percent) performed with BCR implants, 294 procedures (62 percent) with CR implants, and 103 procedures (22 percent) with anterior-stabilized or more constrained designs as a result of increased deformity and/or ligamentous deficiencies. Among patients for whom information was available at 12-month follow-up, the researchers found that knees in the BCR group had higher rates for all-cause revision as well as irrigation and débridement with component retention, compared to the CR group. In addition, there was a greater proportion of radiolucent lines in the BCR cohort compared with the CR cohort. There were no differences between cohorts in Physical Function Computerized Adaptive Test scores, Global10 scores, or knee range of motion outcomes.

Foot and ankle
According to a study published in Foot & Ankle International (online), increased radiographic severity of arthritis may be associated with increased patient satisfaction following total ankle arthroplasty (TAA). The authors reviewed data on 124 patients who underwent TAA performed by a single surgeon. They found that 91.1 percent of patients determined to be KL grade 4 were satisfied at 2-year follow-up, compared to 50.0 percent of patients who were KL grades 1–3. In addition, 93.9 percent of patients who were KL grade felt that their quality of life had been improved by the surgery, compared to 47 percent of KL grades 1–3 patients. Overall, patients who were "very satisfied" or "somewhat satisfied" postoperatively had an average KL grade of 3.9 preoperatively, while "very dissatisfied" and "somewhat dissatisfied" patients had an average KL grade of 2.9.

Surgical decompression of OPLL—
Findings from a study published in The Journal of Bone & Joint Surgery (March 2) suggest that patients with ossification of the posterior longitudinal ligament (OPLL) who are treated with surgical decompression may have similar outcomes to surgically treated patients with other forms of degenerative cervical myelopathy (DCM). The authors conducted a prospective study of 479 patients with symptomatic DCM; 135 patients (28.2 percent) had radiographic evidence of OPLL and 344 patients (71.8 percent) had other forms of DCM. At 2-year follow-up, they found similar outcomes across cohorts in quality of life, Neck Disability Index, and most Short-Form 36 subscales. The authors did note an increased risk of perioperative complication in the OPLL group, although the relationship did not reach statistical significance.

Sports medicine
Overuse injuries—
A study published in AJSM (online) suggests that highly specialized high school athletes may be more likely to report a history of overuse knee or hip injury. The authors surveyed 302 high school athletes who were classified as low specialization (n = 105), moderate specialization (n = 87), or high specialization (n = 110). They found that athletes in the high- specialization cohort were more likely to report a history of overuse knee injuries (n = 18) compared with moderate- (n = 8) or low-specialization (n = 7) athletes. Overall, athletes who trained in one sport for more than 8 months out of the year were more likely to report a history of knee injuries, overuse knee injuries, and hip injuries.

A study published in the Journal of Orthopaedic Trauma (JOT, April) seeks to assess predictors for pulmonary embolism (PE) in trauma patients. The authors reviewed data on 38,597 trauma patients, 239 of whom had a PE. They identified the following seven statistically significant predictors of PE:

  • age
  • obesity
  • injury from motorcycle accident
  • arrival by helicopter
  • emergency department admission pulse rate
  • admission to intensive care unit
  • injury location, including thorax, abdomen, and lower extremity

The authors note that the model was able to discriminate between predicted and actual PE events with a receiver operating characteristic area under the curve of 0.87. They state that identifying the top 25 percent of high-risk patients predicted 80 percent to 84 percent of PE cases.

Bisphosphonates—Several studies published in JOT (April) examine effects of bisphosphonates on patients with atypical fractures. In the first study, the researchers reviewed data on patients with either periprosthetic fracture or femoral fracture who were seen at one of 15 orthopaedic centers in the United States and Canada over a 10-year period. They found that bisphosphonate use was associated with clinically significant differences in time to union, mortality, and complications.

In a second study, the researchers conducted a retrospective review of 179 patients who underwent surgical treatment of bisphosphonate-related fracture. At mean 17-month follow-up, they found a 12 percent surgical failure rate and a delayed average time to union. In addition, 21 percent of patients experienced contralateral femur fractures within 2 years.

A third study looked at 32 patients with 43 fractures and an average duration of bisphosphonate therapy of 7.57 years. The researchers noted an increasing trend of atypical femur fractures and write that bisphosphonate therapy beyond 7 years may place patients at increased risk for such fractures.

Amputee pain—Data from a pilot study presented at the annual meeting of the Society of Interventional Radiology suggest that use of an image-guided, percutaneous, nerve cryoablation technique may reduce "phantom limb" pain for amputation patients. The researchers treated 10 patients with refractory phantom pain following amputation using percutaneous image-guided (computed tomography and ultrasound) cryoablation of the nerve and/or neuroma in their symptomatic residual limb that corresponded to the distribution of their symptoms. All patients saw mild improvements on Visual Analog Scale and Modified Roland Morris Disability Questionnaire scores at 7-day follow-up, and statistically significant improvements at 45-day follow-up.

Fluoroscopy—Findings from a study published online in JOT suggest low risk of harmful radiation at eye level to primary orthopaedic surgeons during fluoroscopic procedures. The researchers conducted a prospective, comparative study of 131 orthopaedic procedures performed by 26 surgeons. Radiation at eye level was detected in 31 cases. The mean radiation dose detected at the eye level of the primary surgeon was 0.02 mSv, per procedure. Femoral nails and pelvic fixation procedures had a significantly higher mean dose received than other procedure groups. No significant difference in doses received by orthopaedic consultants and trainees was found.

Patient safety
Postoperative infection—
Data from a study published in CORR (online) suggest that intra-articular injection prior to TKA may increase risk of postoperative infection, with shorter time between injection and TKA linked to increased likelihood of infection. The research team reviewed data on 29,603 TKAs (35 percent) treated with injection in the ipsilateral knee before the TKA procedure, and 54,081 (65 percent) treated without injection. Compared to controls, they found increased odds of any postoperative infection or infection resulting in return to the operating room among patients who received injection. In a month-by-month analysis of time between injection and TKA, the research team found the likelihood of infection remained higher for the injection cohort to a duration of 6 months between injection and TKA.

PJI—Findings from a study conducted in New Zealand and published in The Bone & Joint Journal (online) looks at factors that may contribute to prosthetic joint infection (PJI) after TKA, and finds that some modern methods of reducing infection may actually increase infection risk. The researchers obtained data on 64,566 primary TKAs from the New Zealand Joint Registry. At minimum 12-month follow-up, they found that male gender, previous surgery, ligament reconstruction, use of laminar flow, and use of antibiotic-laden cement were significantly associated with revision for PJI. In addition, they noted a trend toward significance with the use of surgical helmet systems at 6-month follow-up. The researchers write that "patient factors remain the most important in terms of predicting early PJI following TKA."

Menopause—Three recent studies look at the issue of menopause and bone loss. A paper presented at the annual meeting of the Endocrine Society looks at serum levels of anti-Mullerian hormone (AMH) and suggests that AMH levels may predict the rate of transmenopausal bone loss and help identify women at risk of most loss.

A second paper presented at the meeting suggests that treatment with the investigational drug abaloparatide may help reduce risk of fracture for postmenopausal women. The authors analyzed data from a randomized, double-blind trial covering 2,463 postmenopausal women with osteoporosis and found that administration of abaloparatide was associated with increases in bone mineral density at the lumbar spine, total hip, and femoral neck.

A study published in JAMA Internal Medicine (online) analyzes longitudinal data on 90,014 women and finds that healthy dietary patterns among postmenopausal women may be associated with improved bone health.

Knee and hip OA—
Authors of a study conducted in Switzerland and published in The Lancet (online) compare the effectiveness of NSAIDs with that of acetaminophen for pain in knee and hip OA and conclude that there is "no role for single-agent paracetamol [acetaminophen] for the treatment of patients with osteoarthritis irrespective of dose." The meta-analysis, which surveyed 74 randomized trials with a total of 58,556 patients, compared results involving dosages of seven different NSAIDs and acetaminophen. The study found that among maximally approved daily doses, diclofenac 150 mg/day and etoricoxib 60 mg/day had the highest probability to be the best intervention, with both having 100 percent probability to reach the minimum clinically important difference.