Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

External hip protectors prevented hip fractures in nursing home patients

ACP J Club. 1993 July-Aug;119:20. doi:10.7326/ACPJC-1993-119-1-020


Source Citation

Lauritzen JB, Petersen MM, Lund B. Effect of external hip protectors on hip fractures. Lancet. 1993 Jan 2;341:11-3.


Abstract

Objective

To evaluate the effectiveness of external hip protectors in preventing hip fractures in residents of a nursing home.

Design

Randomized controlled trial of 11 months duration.

Setting

Nursing home in Copenhagen, Denmark.

Patients

665 residents (66% ≥ 80 y, 67% women) living in a nursing home because of aging and inability to care for themselves at home. A third of the residents were cognitively impaired. Patients in the study who died during follow-up were replaced with new arrivals.

Intervention

10 of the 28 wards in the nursing home were randomized to receive external hip protectors. The ratio of treatment to control wards was chosen on the basis of the cost of the hip protectors. The treatment group included 247 residents (167 women), and the control group (no hip protectors) included 418 residents (277 women). The hip protector was fixed in special underwear and was designed to divert a direct impact away from the greater trochanter during falls from standing heights. 2 wards in each of the treatment and control groups were selected at random, and all falls in those wards were recorded.

Main outcome measures

Hip and nonhip fractures.

Main results

8 of 247 residents (3%) in the treatment group and 31 of 418 residents (7%) in the control group fractured a hip (Table). None of the 8 residents in the treatment group who had a hip fracture was wearing the external hip protector at the time of the fracture. 15 residents (6%) in the treatment group and 27 residents (7%) in the control group had a nonhip fracture (absolute difference, 1%). All 15 nonhip fractures in the treatment group were to upper limbs. Among the 116 residents in the fall registration study, 154 falls occurred (64 falls among 45 residents [1.42 falls per resident] in the treatment group and 90 falls among 71 residents [1.27 falls per resident] in the control group) during 11 months of observation. The estimated incidence of falls in the nursing home was 1448 per 1000 residents per year. 20% of these falls produced a direct impact on the hip.

Conclusion

External hip protectors were effective in preventing hip fractures in nursing-home residents.

Source of funding: Not stated.

For article reprint: Dr. J.B. Lauritzen, Department of Orthopaedic Surgery U 2161, Rigshospitalet, University of Copenhagen, Blegdamsveij 9, DK-2100 Copenhagen, Denmark. FAX 45-35-322628.


Table. External hip protectors to prevent hip fractures in nursing home patients

Outcome at 1 month Hip protectors No hip protectors RRR (95% CI) NNT (CI)
Hip fractures 3.2% 7.4% 56% (9 to 79) 24 (13 to 183)

*Abbreviations defined in Glossary; RRR, NNT, and CI calculated from data in article.


Commentary

Hip fracture prevention remains a formidable problem as the incidence of hip fractures continues to increase. Attempts at prevention have focused on bone mineral density (BMD); however, falls are a more important cause of hip fracture than is decreased BMD (1). Recent studies have shown that the potential energy of falls resulting in hip fracture is of a magnitude greater than the average force required to fracture the elderly proximal femur in vitro (2040 newtons) (2). This finding suggests that active energy-absorbing actions by the faller, and passive protection such as hip pads, may prove more effective for preventing hip fractures than efforts aimed at slowing the rate of bone loss in elderly persons. This rationale has led to the design of hip-padding systems to absorb the energy of a fall.

The study by Lauritzen and colleagues is the first randomized clinical trial of a hip-padding system. By randomizing entire wards of the nursing home to receive either the polypropylene-plastozote protector or no protector, the possibility exists that unplanned, concurrent precautions were implemented (e.g., restraint use), biasing results in favor of hip-pad efficacy. The comparable rate of falls among treatment and control patients indirectly militates against this. Nevertheless, because the control group was older, it is possible that higher fracture rates could be explained on the basis of lower BMD in this group.

Poor compliance with the intervention (only 24%) underlines the need for more acceptable pads that can be worn comfortably and discreetly. As the technology of trochanteric padding systems improves and further clinical trials are done, a more acceptable pad will emerge. Given the high rate of hip fractures among the elderly population, this intervention clearly deserves careful evaluation.

Douglas P. Kiel, MD, MPH
Harvard Medical SchoolBoston, Massachusetts, USA


References

1. Hayes WC, Myers ER, Morris JN, et al. Impact near the hip dominates fracture risk in elderly nursing home residents who fall. Calcif Tissue Int. 1993;52:192-8.

2. Lotz JC, Hayes WC. The use of quantitative computed tomography to estimate risk of fracture of the hip from falls. J Bone Joint Surg [Am]. 1990;72:689-700.


Editors Note:

This study has been updated (1) confirming the results of the orginal study.

1. Eckman A, Mallmin H, Michaëlsson K. Ljunghall S. External hip protectors to prevent osteoporotic hip fractures. Lancet. 1997;350:563-4.