Sports Medicine: Just the Facts

properties contribute to tendon rupture commonly
occurring at their insertion sites rather than at their
midsubstance (Zernicke, Garhammer, and Jobe, 1997;
Woo et al, 1988).
•Failure usually occurs during rapid eccentric muscu-
lar contraction when markedly higher forces can be
generated as compared to concentric muscular con-
traction (Garrett, Jr, 1988).
•Several metabolic diseases or direct steroid injection
can predispose to tendon rupture. These conditions
include hyperparathryroidism, calcium pyrophos-
phate deposition disease(CPPD), diabetes mellitus,
chronic renal disease, gout, systemic lupus erythe-
matosus, and rheumatoid arthritis (Woo et al, 1988;
Ford and DeBender, 1979).

• Fluoroquinone antibiotic and isoretinoin treatment
  have been associated with pathologic tendon alter-
  ation and increased incidence of tendon rupture
  (Williams et al, 2000; Scuderi et al, 1993).

PATELLAR TENDON RUPTURES

• The patellar tendon receives its blood supply from the
  vessels within the infrapatellar fat pad and retinacular
  structures (Arnoczky, 1985; Scapinelli, 1968).


• The origin and insertion of the patellar tendon are rel-
  atively avascular.


• Ruptures of the patella tendon most typically occur in
  patients less than 40 years of age and are frequently
  associated with sporting activities including football,
  basketball, and soccer (Matava, 1996).


• Ruptures are most common through the tendon–bone
  junction at the distal pole of the patella.


• Histologic examination of rupture tendon often
  demonstrates an area of degeneration thought to pre-
  dispose these patients to injury.


• Previous surgery including total knee arthroplasty,
  anterior cruciate ligament reconstruction using auto-
  graft patellar tendon, and tibial intramedullary nailing
  have been associated with postoperative patellar tendon
  ruptures (Crossett et al, 2002; Bonamo, Krinick, and
  Sporn, 1984; Keating, Orfaly, and O’Brien, 1997).

CLINICAL PRESENTATION

• At time of injury a pop is often heard with an acute
  onset of pain and swelling. Patient usually unable to
  actively extend knee or maintain it in an extended
  position against gravity. Chronic cases present with an
  extensor lag (Matava, 1996).
  •A palpable defect is commonly present just below the
  distal pole of the patella.
  
  
  • Concomittant anterior cruciate ligament injuries are
    not uncommon and should be clinically ruled out.
  
  
  • Plain radiographs often demonstrate a patella alta in
    comparison to the opposite knee using the Insall-
    Salvati Index (Greater than 1.2) (Aglietti, Buzzi, and
    Insall, 2001).
  
  
  • 
    
  
  
  • An osseous fragment is present at times at the distal pole
    of the patella when an avulsion is part of the injury.
  
  
  • Magnetic resonance imaging(MRI) is useful in cases
    where partial injury is suspected.
  
  
  
  

TREATMENT

•Partial tendon injuries can be treated conservatively

by cylinder cast or brace with the leg placed in full

extension for 4–6 weeks followed by progressive

range of motion and strengthening.

• Complete ruptures should be directly repaired on an
  acute basis through transosseous drill holes through
  the patella. Once secured the knee should have at least
  90 °of flexion to avoid overconstraint. Primary repairs
  are often augmented with wire, mersilene tape, suture,
  or autologous hamstring tendon or iliotibial band
  (Larson and Lund, 1986).


• Chronic ruptures can involve proximal patellar migra-
  tion and can often require quadriceps mobilization or
  V-Y advancement in order to restore patellar height.


• Semitendinosus/gracilis augmentation is recom-
  mended in the chronic scenario. Achilles tendon or
  patellar tendon allograft has often been found useful
  to replace/reinforce the reconstruction in chronic situ-
  ations (Hyman, Rodep, and Wickiewicz, 2003).

COMPLICATIONS

•Following surgery include knee stiffness and weak-

ness. Rerupture is rare. Restoration of normal

patellofemoral tracking and height at the time of sur-

gery is essential to achieve optimal results. Residual

weakness of extensor mechanism is more common in

delayed repairs.

QUADRICEPS TENDON RUPTURES

• The quadriceps tendon is a coalescence of tendinous
  portions of the rectus femoris, vastus lateralis, vastus
  intermedius, and vastus medialis muscle.

Insall - Salvati Index =

Length of patellar tendon

Length of patella

×−()Normal value .08 12.

360 SECTION 4 • MUSCULOSKELETAL PROBLEMS IN THE ATHLETE