An unusual stress fracture of the proximal phalanx of the great toe: A ...

An unusual stress fracture of the proximal phalanx of the great toe: A case
report
G.C. Pitsis* & J.P. Best
Eastern Suburbs Sports Medicine Centre, Sydney, Australia
INTRODUCTION: Stress fracture of the proximal phalanx of the great toe is rare. A medline search was
conducted using the key words “stress fracture” and “great toe” resulting in three specific references. Yokoe and
Mannoji in 1986 published a case series of a sprinter, a Kendo player (Japanese fencer), and a rugby player with
this injury (1). Similarly, Shiraishi and colleagues in 1993 reported 3 cases of this injury in a long distance runner,
a volleyball player, and a soccer player (2). Matsusue and colleagues in 1992 reported this injury in a shot-putter
(3). Interestingly, these stress fractures have only been reported among adolescent athletes. Most stress fractures
were associated with halux valgus deformity.
The pathophysiology involves running and jumping activities inducing vertical ground reaction forces several
times that of body weight. This results in large repetitive truncation forces on the base of the proximal phalanx
from the windlass action of the plantar aponeurosis and muscle action, in addition to axial compressive forces (4).
Hallux valgus is a postulated associated biomechanical predisposing factor to this injury due to the bowstring
effect of extensor hallucis longus and adductor hallucis acting on the great toe. This may increase abduction
forces on the first metatarsophalangeal joint. The resulting tensile strain on the medial collateral ligament and the
medial head of the flexor hallucis brevis may predispose to an avulsion type stress fracture of the medial base of
the proximal phalanx of the great toe (1,2,3,5,6).
It is expected this type of stress fracture would heal with conservative treatment of 4 – 6 weeks non weightbearing
rest. A graduated return to activity over a further 4 – 6 weeks is usually required. Biomechanical factors
need to be addressed appropriately.
CASE REPORT: The patient is a 41-year-old nulliparous non-professional triathlete who was clinically
diagnosed with a stress fracture of the medial base of the proximal phalanx of the left great toe confirmed by x-ray
(Figure 1). Radiologically the stress fracture was undisplaced and involved approximately one third of the articular
surface.
Pain in the left great toe was experienced after progressive moderate increased training load over a 12-week
period leading into a triathlon. This included 20 kilometers of running per week. A mild ache was felt 2 weeks
before competition. After completing the 65-kilometer cycle and 500-meter swim of the triathlon uneventfully,
moderately severe pain was experienced during the first 500 meters of the 4.5-kilometer run. On completion of the
race the patient could not fully weight-bear due to severe pain.
The patient has a past history of multiple stress fractures over the last 4 years including the left fibula in June
1997, the left calcaneus in October 1998, and the right fibula in April 2000, suggesting a low threshold for stress
fractures.
A Dual Energy X-ray Absorptiometry (DEXA) scan in November 1998 revealed osteopenia. At the time of
scanning the patient had 14 months of amenorrhoea. Following treatment with Alendronate (Fosamax), hormone
replacement therapy (Ogen 1.25 mg and Provera 2.5mg), and calcium, follow-up DEXA scans in July 2000 and
May 2001 were normal (Table 1). The patient continues to use hormone replacement therapy and reports normal
menstruation.