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AAOS Now

Published 6/1/2010

Second Look— Clinical News and Views

If you missed these Headline News Now items the first time around, AAOS Now gives you a second chance to review them. Headline News Now—the AAOS thrice-weekly, online update of news of interest to orthopaedic surgeons—brings you the latest on clinical, socioeconomic, and political issues, as well as important announcements from AAOS.

FieldTurf may be safer than grass
A study published in the American Journal of Sports Medicine (AJSM) (April) finds that FieldTurf—an artificial surface designed to replicate certain characteristics of natural grass—may, in some cases, be a safer surface for athletes than natural grass. In a cohort study of 24 universities over three competitive seasons (564 collegiate football games), 230 games were played on FieldTurf and 235 games were played on natural grass. Of 2,253 documented injuries, 1,050 occurred on FieldTurf, and 1,203 on natural grass. A multivariate analysis found significantly lower incidence rates of minor injuries, substantial injuries, and severe injuries on FieldTurf versus natural grass. The findings may only be generally applicable to a collegiate level of competition, however, and the investigation is ongoing.

Detecting pelvic fractures with CT scans
According to a study presented at the annual meeting of the American Roentgen Ray Society, computed tomography (CT) scans may detect pelvic fractures more accurately than standard radiography. A retrospective evaluation of 132 pelvic fracture patients at a single center using CT and radiography found that 48 percent of pelvic injuries were not detected using radiographs. The authors recommend against ordering additional radiographs once a CT scan has confirmed diagnosis of a pelvic fracture.

Biomaterial could promote cartilage regeneration
According to data published online in the Proceedings of the National Academy of Sciences (PNAS), a completely synthetic bioactive biomaterial has the potential to be used therapeutically to promote cartilage regeneration. A co-assembly system of peptide amphiphile (PA) molecules was used to form nanofibers for cartilage regeneration. Growth factor release studies showed that passive release of transforming growth factor ß-1 (TGFß-1) was slower from PA gels containing the growth factor binding sites, and in vitro experiments indicated that the materials support the survival and promote the chondrogenic differentiation of human mesenchymal stem cells.

ACTH, Depo-Medrol, and osteonecrosis of the hip
A study published online in PNAS finds that adrenocorticotropic hormone (ACTH) may protect against methylprednisolone acetate- (Depo-Medrol-) induced osteonecrosis of the femoral head. Compared to controls, rabbits injected with ACTH had significantly reduced osteonecrosis after treatment with glucocorticoids. The therapeutic response may arise from enhanced osteoblastic support and ACTH stimulation of vascular endothelial growth factor. ACTH is largely responsible for maintaining the fine vascular network that surrounds highly remodeling bone.

Bone health may be established at an early age
A study presented at the Experimental Biology 2010 conference suggests that long-term skeletal health may be established during infancy or earlier. Piglets who were fed either a calcium-rich diet or a calcium-deficient diet during the first 18 days of life had no differences in terms of blood markers of calcium status and growth. But many mesenchymal stem cells in the calcium-deficient piglets appeared to have been already programmed to become fat cells instead of bone-forming osteoblast cells, suggesting that the calcium deficiency had predisposed the animals to having bones that contained more fat and less mineral.

Treating carpal tunnel with PCTR or mini-OCTR
A study comparing outcomes of carpal tunnel treatments in the Journal of Hand Surgery (JHS) (March) finds that percutaneous carpal tunnel release (PCTR) and mini-open carpal tunnel release (mini-OCTR) offer similar neurologic recovery, but PCTR leads to less postoperative morbidity and earlier return of function.

An outcomes assessment of 65 women (74 hands) with idiopathic carpal tunnel syndrome—29 women (35 hands) treated using ultrasonically guided PCTR and 36 women (39 hands) treated with ultrasonically guided mini-OCTR—found no significant differences in neurologic recovery between the groups at 3, 6, 13, 26, 52, and 104 weeks (p < 0.05). However, the PCTR group had significantly less pain, greater grip and key-pinch strengths, and significantly better satisfaction scores at 3 and 6 weeks (p < 0.05), and less scar sensitivity at 3, 6, and 13 weeks (p < 0.05).

Surgical total wrist options cost-effective for RA patients
Total wrist arthroplasty (TWA) and total wrist arthrodesis are both cost-effective procedures for treating patients with rheumatoid arthritis (RA), according to data in JHS (March). A time trade-off utility survey of 49 RA patients who were recruited as part of an ongoing prospective study, along with a random national sample of 109 hand surgeons and rheumatologists, found that patients and physicians both showed a preference for surgical management over nonsurgical management. The incremental cost per additional expected quality-adjusted life-year (QALY) gained for TWA over nonsurgical management was calculated to be $2,281, and the incremental cost per QALY gained with TWA over total wrist arthrodesis was $2,328, which is substantially less than the national standard of $50,000/QALY deemed acceptable for adoption.

Osteochondral allografting for osteonecrosis?
According to a study in Clinical Orthopaedics and Related Research (April), osteochondral allografting may be a reasonable salvage option for corticosteroid-associated osteonecrosis of the femoral condyles, particularly among young, active patients, enabling them to defer or avoid total knee arthroplasty. An evaluation of 22 patients (28 knees) who underwent osteochondral allografting for high-grade, corticosteroid-associated osteonecrosis found that mean International Knee Documentation Committee (IKDC) pain scores improved from 7.1 to 2.0, mean IKDC function scores from 3.5 to 8.3, and mean Knee Society function scores from 60.0 to 85.7. Patients ranged in age from 16 to 44 years and had a mean follow-up of 67 months. The mean graft surface area was 10.8 cm2 (range 5 to 19 cm2). The overall graft survival rate was 89 percent (25 of 28).

Reconstruct FCL and PLC after multiligament knee injuries
According to data in AJSM (April), single-stage reconstruction of the fibular collateral ligament (FCL) and posterolateral corner (PLC) may be a more reliable option than repair followed by delayed cruciate ligament reconstruction for multi-ligament knee injuries. The cohort study of 28 patients (28 knees; 10 repair, 18 reconstruction) with multiligament knee injuries treated by a single surgeon between May 2005 and February 2007 found that four repairs (40 percent) had failed by a mean 34-month follow-up, and one reconstruction (6 percent) had failed by a mean 28-month follow-up (p = 0.04). A regression analysis showed no effect on failure based on age, sex, injury mechanism, time to surgery, interval between stages, total number of ligaments injured, or location of tear.

Mid-term outcomes similar for CC, CP hips
According to data published in the Journal of Arthroplasty (April), there is no significant difference in mid-term outcomes between THA patients who receive alumina ceramic-on-ceramic (CC) articulation and those who receive ceramic on ultra high molecular weight polyethylene articulation (CP). The prospective, randomized trial involved 55 patients (56 hips; mean age, 42.2 years; range, 19 to 56 years) who received uncemented components and a 28-mm alumina head with randomization of the acetabular liner. No differences in outcome scores were found at up to 10 years follow-up (median, 8 years; range, 1 to 10 years). Wear was identified in 32 of 33 CP hips, but in only 12 of 23 CC hips. Mean wear in the CP group was 0.11 mm per year versus 0.02 mm per year in the CC group (p < 0.001).