Sports Medicine: Just the Facts

CHAPTER 66 • LOWER EXTREMITY STRESS FRACTURE 393

return to athletics (Volpin et al, 1990). If a fracture is

present, orthopaedic consultation is usually indicated.

FEMORALDIAPHYSIS

• The femoral diaphysis are relatively common but
  often misdiagnosed as muscle or tendon injuries. In a
  study of college athletes, an incidence of 20.6%
  femoral diaphysis stress fractures was found
  (Johnson, Weiss, and Wheeler, 1994; Lombardo and
  Benson, 1982; Hershman, Lombardo, and Bergfeld,
  1990).


• MRI shows typically periosteal as well as bone
  marrow edema involving the medial aspect of the
  proximal femur at the junction of the proximal and
  middle thirds of the femoral disphysis (Bergman and
  Fredericson, 1999; Hershman, Lombardo, and
  Bergfeld, 1990).
  •Physical examination may reveal local tenderness,
  with normal hip range of motion. Hopping on the
  affected side will typically reproduce pain in the
  involved bone. The fulcrum test can be helpful in
  localizing the anatomic site of involvement (Johnson,
  Weiss, and Wheeler, 1994).

PATELLA

• Stress fracture of the patella is a rare injury that occurs
  in jumping sports. It may have an insidious or acute
  onset (Fredericson, Bergman, and Matheson, 1997).


• The clinical findings are localized tenderness over the
  patella. Most patellar stress fractures are of the trans-
  verse type. These may be confused radiographically
  with bipartite patella; however, a patella fracture line
  tends to be more oblique than the bipartite patella.

TIBIA

POSTERIOR-MEDIAL

• The many athletes, particularly runners, with stress
  fracture of the tibia present with gradual onset of pain
  along the medial border of tibia aggravated by exer-
  cise. Pain may occur with walking, at rest or even at
  night (Fredericson et al, 1995).


• It is often difficult to clinically distinguish the more
  severe tibial stress reaction or fracture from the more
  common medial tibial stress or shin splint syndrome
  (tibial periostitis). A recent study concluded that the
  periostitis (seen as periosteal edema on MRI) may be
  the initial injury on a spectrum that if allowed to
  progress may evolve into a more serious bone injury
  (Fredericson et al, 1995; Mubarak et al, 1982).


• The physical examination findings such as localized
  tibial tenderness and pain with direct or indirect (at a
  distance from the site of tenderness) percussion over

the involved bone help distinguish that from more

common medial tibial stress syndrome (shin splint)

(Fredericson et al, 1995).

• The pain is occasionally aggravated by testing muscle
  strength actively, particularly in those muscles that
  have origins on the posterior medial border including
  the soleus (best tested by repetitive toe raises), poste-
  rior tibialis, and flexor digitorum longus.


• It is also important to evaluate the runner’s lower
  extremity alignment as well as mechanical gait, such
  as excessive foot pronation, hindfoot and forefoot
  varus increasing stress to the tibia during running.
  Thus, many athletes benefit from a foot orthosis to
  help control pronation (Bergman and Fredericson,
  1999; Fredericson et al, 1995).
  •A temporary cessation of running is essential to allow
  for bony remodeling and repair. This can range from
  a few days to three weeks for a minor injury to 12
  weeks for a severe injury with frank cortical fracture.
  If there is pain with daily activities a pneumatic tibial
  brace can be used for immobilizing distal and midtib-
  ial injuries (Fredericson et al, 1995).

ANTERIOR-MID-TIBIA

• A typical stress fracture of the anterior cortex of the
  midtibia occur almost exclusively in athletes perform-
  ing jumping and leaping activities. These fractures
  occur on the tension side of bone and are thus prone
  to delayed union, nonunion, or even complete fracture
  (Orava and Hulkko, 1984).


• The cortical transverse lesion is known as the dreaded
  black line for its propensity to nonunion or even pro-
  gression to a complete fracture that may displace
  (Orava and Hulkko, 1984).


• These patients require treatment in a nonweightbear-
  ing braces for 6 to 8 weeks. Surgical excision and bone
  grafting or placement of an intramedullary rod is indi-
  cated after 3 to 6 months of failed closed management.

TIBIALPLATEU

• Stress reaction and fractures occur less frequently in
  the medial tibial plateau than in the tibial diaphysis.
  Furthermore, medial tibial plateau stress injuries are
  often misdiagnosed as per anserinus tendinitis or bur-
  sitis (Harolds, 1981).


• If radiographs are positive at presentation, they typi-
  cally show a linear transverse region of sclerosis 2- to
  3-mm wide in the medial plateau close to the level of
  the epiphyseal scar.


• An MRI examination may demonstrate bone marrow
  edema of the medial tibial plateau before radiographic
  sings appear, with periosteal edema present and some-
  times presence of a fracture line (Bergman and
  Fredericson, 1999).