Interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults.

Gillespie WJ, Grant I. Cochrane Database Syst Rev 2000;(2):CD000450.

BACKGROUND.
Stress reaction in bone, which may proceed to a fracture, is a significant problem in military recruits and in athletes, particularly long distance runners.

OBJECTIVES.
To evaluate the evidence from controlled trials of treatments and programmes for prevention or management of lower limb stress fractures and stress reactions of bone in active young adults.

SEARCH STRATEGY.
We searched the Cochrane Musculoskeletal Injuries Group Trials Register, The Cochrane Library, MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, Index to UK Theses and the bibliographies of identified articles. Date of last search: December 1997.

SELECTION CRITERIA.
Any randomised or quasi-randomised trial evaluating a programme or treatment to prevent or treat lower limb stress reactions of bone or stress fractures in active young adults.

DATA COLLECTION AND ANALYSIS.
Searching, a decision on inclusion or exclusion, methodological assessment, and data extraction were carried out according to a predetermined protocol included in the body of the review. Analysis using Review Manager software allowed pooling of data and calculation of Peto odds ratios and absolute risk reductions, each with 95% confidence intervals.

MAIN RESULTS.
The use of “shock absorbing” insoles, evaluated in four trials, appears to reduce the incidence of stress fractures and stress reactions of bone (Peto odds ratio 0.47, 95% confidence interval 0. 30 to 0.76). Incomplete data from one trial indicated that reduction of running and jumping intensity may also be effective. The use of pneumatic braces in the rehabilitation of tibial stress fractures significantly reduces the time to recommencing training (weighted mean difference -42.6 days, 95% confidence interval -55.8 to -29.4 days).

REVIEWER’S CONCLUSIONS.
The use of shock absorbing insoles in footwear reduces the incidence of stress fractures in athletes and military personnel. Rehabilitation after tibial stress fracture is aided by the use of pneumatic bracing.

Risk factors for stress fractures.

Bennell K, Matheson G, Meeuwisse W, Brukner P. Sports Med 1999 Aug;28(2):91-122.

Preventing stress fractures requires knowledge of the risk factors that predispose to this injury. The aetiology of stress fractures is multifactorial, but methodological limitations and expediency often lead to research study designs that evaluate individual risk factors. Intrinsic risk factors include mechanical factors such as bone density, skeletal alignment and body size and composition, physiological factors such as bone turnover rate, flexibility, and muscular strength and endurance, as well as hormonal and nutritional factors. Extrinsic risk factors include mechanical factors such as surface, footwear and external loading as well as physical training parameters. Psychological traits may also play a role in increasing stress fracture risk. Equally important to these types of analyses of individual risk factors is the integration of information to produce a composite picture of risk. The purpose of this paper is to critically appraise the existing literature by evaluating study design and quality, in order to provide a current synopsis of the known scientific information related to stress fracture risk factors. The literature is not fully complete with well conducted studies on this topic, but a great deal of information has accumulated over the past 20 years. Although stress fractures result from repeated loading, the exact contribution of training factors (volume, intensity, surface) has not been clearly established. From what we do know, menstrual disturbances, caloric restriction, lower bone density, muscle weakness and leg length differences are risk factors for stress fracture. Other time-honoured risk factors such as lower extremity alignment have not been shown to be causative even though anecdotal evidence indicates they are likely to play an important role in stress fracture pathogenesis.

Less common stress fractures in the foot.

Meurman KO. Br J Radiol 1981 Jan;54(637):1-7.

In a series of 827 stress fractures in soldiers, 15 were found in the first metatarsal, representing 11% of all stress fractures in the metatarsals. All were in the proximal end of the bone. Eight fractures were found in the fourth and four in the fifth metatarsal. In the cuneiform bones three fractures were found, and one in the talus. One fracture was revealed in the lateral sesamoid of the hallux and one in the peroneal bone. Ten patients had stress fractures in other bones too. The radiological appearance and the corresponding stress mechanisms are discussed.