Published 10/1/2013

Second Look – Clinical News and Views

Displaced intra-articular calcaneal fractures
According to findings in Journal of Bone & Joint Surgery (JBJS) (Aug. 7), surgical treatment may be superior to nonsurgical treatment of displaced intra-articular calcaneal fractures, but only at long-term follow-up. The authors of the prospective, randomized, controlled trial of 42 patients treated surgically and 40 patients treated nonsurgically found that primary and secondary outcome measures did not differ significantly between the two treatment groups at 1-year follow-up. Among the 58 patients available at 8- to 12-year follow-up, there was a trend toward better scores on the patient-reported primary visual analog scale score for pain and function and the physical component of the SF-36 in the surgical group. The prevalence of radiographically evident posttraumatic subtalar arthritis was lower among patients in the surgical group.

Use of lateral wedge orthotics for knee OA
Findings in the Journal of the American Medical Association (JAMA) (Aug. 21) question the efficacy of lateral wedge shoe insoles for the reduction of knee pain associated with medial osteoarthritis. The meta-analysis of 12 trials covering 885 participants, 502 of whom received lateral wedge treatment, found that the use of orthotics did significantly impact pain levels compared to controls, but such impact was generally limited to studies determined to have a greater risk of bias. Studies that compared the use of orthotics against neutral inserts (for improved blinding) consistently demonstrated no significant or clinically important impact from lateral wedges.

The AAOS Clinical Practice Guideline on Treatment of Osteoarthritis of the Knee covers the use of lateral wedge orthotics and can be found at www.aaos.org/guidelines

Treatment of pediatric upper extremity fractures
A study in the JBJS (Aug. 7) questioned a trend toward more aggressive treatment of pediatric upper extremity fractures. Researchers found that a higher proportion of studies presented at Pediatric Orthopaedic Society of North America and AAOS annual meetings (1993–2012) gave less aggressive or neutral recommendations than those that offered more aggressive treatment recommendations. Only 24 percent of surgical studies and 11 percent of nonsurgical studies recommended more aggressive treatment.

Ion concentrations in MOM HR, THA patients
A study published online in Clinical Orthopaedics and Related Research compared serum ion concentrations in metal-on-metal (MOM) hip resurfacing (HR) patients to those in MOM total hip arthroplasty (THA) patients. The therapeutic study included 25 MOM HR patients, 16 MOM THA patients, and 48 controls. Ion concentrations of cobalt, chromium, and molybdenum in MOM HR patients were higher than those in the control group, and chromium and cobalt release were higher in MOM HR patients than in MOM THA patients. Researchers call for “strict biomonitoring” for patients with MOM implants.

Mobile-bearing UKAs
A study in JBJS (Aug. 7) suggests that cementless fixation may provide improved fixation compared with cemented fixation in mobile-bearing unicompartmental knee arthroplasty (UKA). The randomized, controlled trial of 63 knees (62 patients) who received either cemented (n = 32) or cementless (n = 30) Oxford UKA found that Knee Society functional score and change in the Knee Society functional score were significantly better in the cementless group at 5-year follow-up. The cemented group had significantly more tibial radiolucencies.

Risk factors for infection
A study in the Journal of Orthopaedic Trauma (September) evaluated risk factors for infection after bicondylar tibial plateau fractures. A review of 302 patients who were seen at a single, high-volume, level 1 trauma center (2002–2010) found that deep infection requiring reoperation developed in 43 patients (14.2 percent). Open fracture, smoking, compartment syndrome requiring fasciotomies, and fractures requiring two incisions and two plates were risk factors. Methicillin-resistant Staphylococcus aureus was cultured in 20 (46.5 percent) of the 43 patients with deep infections.

Acute displaced midshaft clavicular fractures
A study in JBJS (Sept. 4) reports on a multicenter, single-blinded, randomized controlled trial involving 200 patients (16 to 60 years old) with acute displaced midshaft clavicular fractures randomized to either primary open reduction and plate fixation or nonsurgical treatment. Although open reduction and plate fixation had a significantly lower risk of nonunion compared with nonsurgical treatment (1 nonunion in the surgical group compared to 16 in the nonsurgical group), when these patients were excluded from functional analyses, researchers found no significant differences in the Constant or Disabilities of the Arm, Shoulder, and Hand (DASH) scores at any time point in the study. Researchers concluded that the cost and associated implant-related complications outweighed the benefits of preventing nonunions and do not support routine use of surgical treatment for these fractures.

Posterior spinal constructs
Findings from a study in Spine (Aug. 15) suggest that the use of cross-links as adjuvants in posterior spinal constructs may be avoidable. The retrospective evaluation of 208 patients who underwent surgery without the use of cross-links (July 2007–July 2011) found that, at average 15-month follow-up, only one demonstrated any rotational instability in follow-up radiographs.

Herniated lumbar disks
Data from a study in Spine (Aug. 1) suggest that lumbar disk herniation (LDH) more commonly results from endplate junction failure (EPJF) than annulus fibrosus (AF) rupture. The prospective, multimodal study of 181 consecutive patients who required microdiskectomy at a single level found that herniated disks had a significantly higher incidence of EPJF than other disks, and LDH due to EPJF was more common than AF rupture. EPJF was radiologically evident as a vertebral corner defect in 30 patients, as rim avulsion in 46 patients, as frank bony avulsions in 24 patients, and as avulsion at both upper and lower endplates in four patients.

BMP in lumbar fusion
A study in Neurosurgery (September) found that the use of bone morphogenetic protein (BMP) in lumbar fusion may be associated with a significantly higher rate of benign neoplasms, but not malignancies. Based on a retrospective database study of 4,698 patients in a propensity score-matched cohort, BMP exposure was associated with a 31 percent increase in the risk of benign tumor diagnoses after adjustment, but there was no significant difference in the rate of cancer diagnoses between BMP patients and non-BMP patients.

Use of chlorhexidine cloths in TKA
A study in the Journal of Arthroplasty (August) examined the economic impact of adding 2 percent chlorhexidine gluconate-impregnated cloths to existing preoperative preparation protocols at a single high-volume arthroplasty center. Data from the National Healthcare Safety Network (NHSN) and other published reports were used to determine a range of surgical site infection rates following total knee arthroplasty (TKA) and the cost per revision procedure. The use of chlorhexidine cloths was associated with a net savings of approximately $2.1 million per 1,000 TKA patients at a single institution, against an estimated cost of $14,000 ($14 per patient). Based on the reported NHSN infection rate, the use of chlorhexidine cloths could save $0.78 billion annually.

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)