CHAPTER 61 • SOFT TISSUE KNEE INJURIES (TENDON AND BURSAE) 361- The quadriceps tendon receives its vascular supply
from an anastomatic network including the lateral cir-
cumflex femoral artery, descending geniculate artery,
and medial/lateral geniculate arteries (Peterson, Stein,
and Tillman, 1999). - There is an avascular region of the deep part of the
quadriceps tendon measuring 1.5 ×3.0 cm. - Ruptures of the quadriceps tendon most typically
occur in patients over 40 years of age and are three
times more frequent than patella tendon ruptures.
Unilateral injuries are up to 20 times more frequent
than bilateral injury (Ilan et al, 2003). - The site of rupture usually occurs through a degener-
ative area within the tendon and seldom occurs in
younger individuals. Systemic disease can lead to
tendon degeneration and predispose to infrequent
bilateral tendon ruptures (Lauerman, Smith, and
Kenmore, 1987).
CLINICAL PRESENTATION
•Pain is often present before rupture. At time of injury
a pop is often heard with an acute onset of pain and
swelling.
- In cases of partial injury or complete injuries that do
not extend to include the retinacular tissue, the patient
may be able to extend and resist gravity with an asso-
ciated extensor lag but in complete injuries this is not
possible.
•A palpable defect at the site of rupture is usually felt
just superior to the proximal pole of the patella. - Plain radiographs often demonstrate patellar baja, an
avulsion of the superior pole of the patella, spurring of
the superior patellar region, or calcification within the
quadriceps tendon. Insall-Salvati ratio less than 0.8
(Aglietti, Buzzi, and Insall, 2001). - Magnetic resonance imaging is useful adjunct study
as it can demonstrate partial ruptures or preexisting
disease within the quadriceps tendon.
TREATMENT
•Partial tears are often responsive to conservative treat-
ment when the patient presents primarily with pain
and has little loss of strength, retaining the ability to
actively extend the knee against gravity.
- Conservative treatment consists of a long leg cylinder
cast in full extension for 4–6 weeks, with progressive
range of motion and strengthening thereafter for par-
tial injuries. - Complete ruptures respond best to immediate surgi-
cal repair in a direct end-to-end fashion after tendon
debridement of necrotic tissue or with transosseous
tunnels through the patella (Rasul and Fischer,
1993).- Chronic rupture involving more significant tendon
retraction often require quadriceps tendon advance-
ment through a tendon Z-plasty or V-Y advancement
technique. Interpositional autograft/allograft tendon
has been utilized with success in this scenario
(Scuderi, 1958). - Success of repair is direct related to the length of time
between injury and the time of surgery, with more
chronic repairs producing less favorable outcomes.
Age is also a factor with better results in younger
patients (Konrath et al, 1998). - Most common complications following surgery or
conservative treatment include decreased quadriceps
strength/function with an associated extensor lag and
lack of knee flexion.
GASTROCNEMIUS RUPTURE- Often referred to as tennis leg.
•Traumatic injury to middle aged athlete presenting as
sudden pain in posterior proximal calf region.
Significant pain, swelling, and ecchymosis usually
occur with 24 h.
•Involves tearing of the medial head of the gastrocne-
mius muscle typically at its musculotendinous junc-
tion (Miller, 1977). - Mechanism of injury combines ankle dorsiflexion in
combination with knee hyperextension.
DIFFERENTIAL DIAGNOSES- Differential diagnoses involve plantaris rupture,
thrombophlebitis, and an acute compartment syn-
drome (Severence and Bassett, 1982). - Magnetic resonance imaging (MRI) remains the
imaging modality of choice. Ultrasound can be
employed to rule out thrombophlebitis. - Can be associated with an acute compartment syn-
drome secondary to swelling.
TREATMENT•Treatment of isolated ruptures of the medial gastroc-
nemius involves compressive wrapping, activity mod-
ification including crutches if necessary, ankle range
of motion, ice, and anti-inflammatory medications
(Gecha and Torg, 1988).