This document discusses extensor mechanism injuries in the knee, focusing on quadriceps and patellar tendon ruptures, including their anatomy, mechanisms of injury, and clinical presentation based on patient demographics. It details management strategies for both conservative and operative treatments, emphasizing the importance of timely surgical intervention for better outcomes. Imaging techniques such as X-rays, ultrasound, and MRI are also outlined, along with the post-operative care and rehabilitation protocols for recovery.

1. Presenter : Dr Yash Oza
Moderator : Dr Ravindra Patil

2. Introduction
• Patients with
• loss of active knee extension
• as a result of trauma
• without signs of a patellar fracture
• may have a disruption of the extensor mechanism.
• Injuries to the extensor mechanism can include
• quadriceps or patellar tendon ruptures,
• patellar dislocations, or
• tibial tubercle avulsions.
Can rule out
with the xray

3. Patellar and Quadriceps Tendon
Rupture
• Anatomy
• Quadriceps femoris muscle has
four parts: rectus femoris, vastus
lateralis, vastus medialis, and
vastus intermedius.
• The quadriceps tendon inserts
onto the base of the patella. Distal
to the patella, it continues as
the patellar ligament.

4. Origins Rectus femoris: anterior
inferior iliac spine, superior
margin of the acetabulum of
hip bone
Vastus medialis: intertrochant
eric line of femur
Vastus lateralis: linea aspera,
greater trochanter of femur
Vastus intermedius: anterior
surface of shaft of femur
Insertions Tuberosity of the tibia (via the
patellar ligament)
Innervation Femoral nerve (L2-L4)
Actions Hip joint: Thigh flexion (rectus
femoris only)
Knee joint: Leg extension

5. • Patellar Tendon
• Average 4mm thick, but
widens to 5-6mm at
insertion in to tibial
tuberosity
• Merges with Medial &
Lateral retinaculum
• Blood Supply
• Fat pad vessels supply
posterior aspect of tendon
via Med. & Lat. Inferior
Geniculate A.
• Retinacular vessels supply
Anterior portion of tendon
via Lat. IG & Recurrent Tibia
A.
• Proximal & distal insertion
area are relatively avascular
and are a common site of
rupture
Patel
lar
tend
on
Lat.IG &
Rec.TA
Med.IG &
Lat.IG
Relatively avascular
Relatively avascular
Ant. Post.

6. • Biomechanics
• Greatest force is applied at 60 degree flexion
• 3-4 times force at @ insertion as compared to
midsubstance
• While climbing stairs forces through patellar tendon is
x3.2 times body weight

7. Mechanism of Injury
• Quadriceps and patellar tendon ruptures are
typically low-energy injuries.
• Typically, the patient sustains a forceful quadriceps
contraction against a fixed or sudden load of full
body weight with the knee in a flexed position.
• In high-energy injuries it may accompany ACL tear
in 12.5% cases.

8. Clinical Presentation
• Age Group commonly involved
• Patellar tendon ruptures : <40 years old
• quadriceps tendon ruptures : >40 years of age
• Quadriceps tendon ruptures occur more commonly
in patients with systemic disease or degenerative
changes.
• Bilateral quadriceps tendon rupture may occur in
patients with systemic illness and obesity. Bilateral
rupture of the patellar tendon can occur but is less
frequent.

9. • History of jumping,squatting or stumbling.
• Pain with an associated tearing or popping
sensation is typical, as is the inability to bear
weight.
• Painful passive knee flexion
• Lack of active knee extension or the inability to
maintain the passively extended knee against
gravity
• Patellar tendon ruptures extend completely through the
retinacular tissue resulting in complete loss of knee
extension.
• In Quadriceps tendon ruptures some extension still may
be possible as whole retinacular tissue is not involved.

10. • Immediately after injury, a defect may be palpable
at the level of the rupture.
• However, when the diagnosis is delayed, the
tendon defect may not be palpable secondary to
consolidation of the hematoma and early scar
formation.
• A traumatic hemarthrosis is common after extensor
mechanism injuries.

11. • History of Prodromal symptoms :
fever, malaise, headache
• In general, healthy tendons do not rupture. Tensile
overload of the extensor mechanism usually leads
to # patella which is considered the weakest link.
• Thus Patellar tendon ruptures have been
considered the end stage of long-standing chronic
tendon degeneration.
• So Prodromal Symptoms are frequently associated
with tendon rupture.
• Complaint of chronic pain is also present at site of
the injury.

12. • Risk factor for Quadriceps/Patellar Tendon Rupture
• Rheumatoid
• SLE
• Diabetes –( Patellar Tendon more association)
• Chronic Renal Failure
• Systemic corticosteroid therapy
• Anabolic steroid use with Heavy Exercise –( Quadriceps
Tendon more association)
• Local steroid injection
• Chronic patellar tendonitis
• Fluoroquinolone antibiotics

13. Imaging
• Xray
• An AP and lateral plain radiograph
should be obtained in all patients.
• Patellar Tendon Rupture :
• The unopposed pull of the
quadriceps muscle will result in
proximal migration of the patella.
• Patella alta - position of the patella is
considered higher than normal
• position of the patella superior to
Blumensaat's line on the lateral
radiograph
• Insall-Salvati Index - normal value
between 0.8-1.2 . If the ratio is
higher than there is patella alta

14. Blumensaat's
line should extend to
inferior pole of the
patella at 30 degrees
of knee flexion
Blumensaat line is a line
which corresponds to the
roof of the intercondylar
fossa of the femur as seen
on a lateral radiograph of
the knee joint.

15. • Xray findings suggestive of a quadriceps tendon
rupture include
• obliteration of the quadriceps tendon shadow,
• a suprapatellar mass,
• suprapatellar calcific densities
• an inferiorly displaced patella.

16. Degenerative spurring (“tooth sign”), as seen on a lateral
view, may indicate significant changes in the quadriceps
mechanism

17. •USG
• High-resolution ultrasonography has been
recognized as an effective method of
examining the patellar and quadriceps
tendons in both acute and chronic
injuries.
• Routinely done method to confirm
diagnosis.

18. • MRI is very effective but expensive, method of
diagnosing.
• It is not recommended in the evaluation of most
suspected extensor mechanism injuries, but may
be helpful in patients with neglected tears or
partial tendon injuries or high-energy injury.
Normal
Quadriceps Rupture Patellar Tendon Rupture

19. Initial Management
• RICE
• A traumatic hemarthrosis is common after
tendon ruptures.
• Ice, compression, elevation, and anti-
inflammatory medications can be used to treat
local symptoms.
• Role of Knee aspiration
• no studies have shown a benefit for knee aspiration in
these injuries,
• aspiration of a tense hematoma WAS considered to
reduce pain and promote recovery.

20. Treatment Options :
Conservative & Operative
Indication Relative Contraindication
• Incomplete ruptures
are usually managed
conservatively if full
active extension is
present
• If Medically unfit for
surgery
• Open injury
• Extensor lag
• Loss of knee extensor
function
Conservative Treatment

21. Conservative Treatment
• The limb is initially immobilized with the knee in full
extension for 4 to 6 weeks,
• after which, protected range of motion and
strengthening are begun.
• Initially, flexion of greater than 90 degrees is
avoided to reduce stress on the tendon.
• Restrictions are removed once the patient achieves
good quadriceps muscle control and is able to
perform a straight-leg raise without discomfort.

22. • Nonsurgical management of a complete quadriceps
or patellar tendon rupture generally yields poor
results
• long-term disability in gait and weakness.
• Untreated complete ruptures will result in
ambulation with a stiff-knee gait or circumduction
to allow the foot to clear the ground during the
swing phase of gait.
• Patients will also complain of knee buckling and
difficulty in climbing stairs.
• And Loss of extensor mechanism function is an
indication for surgery.
Outcome of conservative treatment

23. Operative Treatment
• Operative treatment is indicated for all tendon
ruptures in which extensor mechanism function is
compromised.

24. Patient positioning
• Supine positioning
• A small bump under the hip is helpful for external
rotation of the limb
• Another small bump that can be
• moved below the knee for slight flexion or
• under the ankle for knee extension

25. Surgical Approach
• An extensile straight midline
incision
• inferior patella to 5 cm
proximal to the quadriceps
tendon rupture
• superior patella to the tibial
tubercle for patellar tendon
ruptures.
5cm

26. Acute v/s Chronic Tendon Tear
• In acute cases end-to-end repair is possible
• But in chronic cases there is a large defect
preventing apposition of ends
• In quadriceps rupture >2weeks , a gap of 5cm is
formed due to muscle retraction.
• Various muscle release or lengthening procedures
may be required in chronic cases.

27. Suture repair through bone tunnel
• Passage of two heavy non-absorbable sutures into the tendon.
• Three parallel drill holes are then created from superior to
inferior through the patella.
• The sutures are passed through the drill holes and tied at the
inferior patella
REPAIR OF ACUTE RUPTURE OF THE QUADRICEPS TENDON
• Tensioning of suture to allow 90
to 100 degrees of passive flexion
has been recommended.
• The tendon should be repaired
adjacent to the articular surface
because if sutured to anterior
surface it will lead to tilting of
the patella.

28. Codivilla tendon lengthening and repair of quadriceps tendon
• An inverted V is cut through the full thickness of the proximal segment of the
quadriceps tendon
• A triangular flap is split into 2 part
• Anterior part of one third of its thickness and
• a posterior part of two thirds.
• Anterior part of the flap is turned distally and is sutured.
REPAIR OF CHRONIC RUPTURE OF THE QUADRICEPS TENDON

29. • The cylinder cast or knee brace for 6 weeks.
• Weight bearing with crutches is allowed at 3 weeks.
• After Cast removal range of knee motion from 0 to
60 degrees; the range is increased 10 to 15 degrees
each week.
• An aggressive strengthening program is essential
for good functional recovery.
POSTOPERATIVE CARE FOLLOWING
QUADRICEPS TENDON REPAIR :

30. SUTURE REPAIR OF ACUTE PATELLAR
TENDON RUPTURE
• The site of the tear (proximal, midsubstance,
or distal) will dictate the preferred surgical
repair technique.
• Most patellar tendon ruptures occur at the
insertion on the inferior pole of the patella as
an avulsion.
• It is done by passage of 3 heavy non-
absorbable sutures into the tendon.
• 4 parallel drill holes are then created from
inferior to superior in the patella.
• The sutures are passed through the drill holes
and tied at the superior pole of the patella.

31. If the patellar tendon is extensively
frayed, 2 running interlocking non-
absorbable sutures can be used to secure
the tendon.
• Use a suture retriever or Beath pin to
thread the suture strands through 3-
mm drill tunnels,
• one horizontally into the tibial tubercle
• two vertically into the patella
*If secure fixation cannot be obtained
with this method, augment the repair
with the semitendinosus or gracilis
tendon.
MERSILENE LOOP TENDON REPAIR
(ACUTE)

32. RUPTURES THROUGH THE SUBSTANCE
OF THE TENDON
• The tendon is split in 3 bundles. (2 with
long arm directed upwards & 1 downwards)
• Running interlocking sutures placed in
bundles
• 2 parallel vertical holes drilled in the patella
& 1 transverse hole drilled in the tibial
tuberosity.
• Sutures are passed through holes & tied.
• Repair the individual bundles side-to-side
after appropriate tendon length is
determined.
*If needed place a circumferential tension
suture of non-absorbable box wire.
(ACUTE)

33. SUTURE ANCHOR REPAIR OF PATELLAR
TENDON RUPTURE
• For proximal avulsion of the tendon
from the patella, place three suture
anchors equidistant along the inferior
pole of patella.
• Pull the suture through the anchor eyelet
Pass the one suture arm down and back
of the tendon stump in a locking Krackow
fashion, and pull the another arm to
reduce the tendon & Tie each suture
securely.
• For distal avulsion of the tendon, the
same procedure is used but the suture
anchors are placed in the tibial tubercle
(ACUTE)

34. POSTOPERATIVE CARE following repair
of acute patellar tendon repair
• Weight bearing is allowed with the knee braced in
full extension.
• Range of Motion is progressed as tolerated, with
the goal of
• 90 degrees of flexion by 4 to 6 weeks and
• full motion by 10 to 12 weeks.
• Isometric quadriceps contractions can be done
immediately after surgery,
• Progressing to straight-leg raises start at 6 weeks.
• Full return to activities after 6 months.

35. TREATMENT OF CHRONIC
RUPTURE OF PATELLAR TENDON
In chronic cases patella is retracted proximally
and may require extensive surgical release to draw it
distally to the appropriate level.
Before surgery, lateral radiographs of the
uninvolved extremity should be obtained with the
knee flexed to 45 degrees to evaluate patellar height;
• These are compared with radiographs of the
involved knee during surgery to determine the
appropriate tendon length.

36. • Preoperative traction through a
K-wire placed transversely in the
patella was used
• But, better results can be
obtained with proximal release
of scar tissue and a modified
Thompson quadricepsplasty, if
necessary.
• Modified Thompson
quadricepsplasty is a Z-plasty
lengthening of the rectus
femoris tendon

37. If sufficient patellar
tendon is left for
repair,
augmentation with
the
semitendinosus or
gracilis tendon
may be indicated.
If the rupture is
several months old,
an allograft can be
used, and an
Achilles tendon
allograft is used.

38. ACHILLES TENDON ALLOGRAFT FOR
CHRONIC PATELLAR TENDON RUPTURE
• Use an oscillating saw to make a slot in
Tibial tuberosity
• Contour the bone attached to the Achilles
tendon to fit flush in the slot
• Split the Achilles tendon graft into three
branches, the central branch should be 8 to
9 mm in diameter.
• Central arm of graft is placed through 9 mm
longitudinal tunnel and then through
vertical slit in quadriceps tendon.
• Tunnel is placed centrally to avoid
penetration of articular cartilage.
• Graft is secured with multiple sutures.

39. POSTOPERATIVE CARE.
• Apply cylindrical cast post-OP. At 10 to 14 days, the cast
is removed for wound evaluation.
• A cylinder cast or locked brace is worn for 4 to 6 weeks.
• At 4 to 6 weeks, after removing cast Active and passive
range-of-motion exercises are begun.
• Weight bearing to tolerance with crutches is allowed
until sufficient motion and strength is gained.
• A progressive strengthening and range-of-motion
exercise program is essential to regain function.

40. HAMSTRING (SEMITENDINOSUS AND GRACILIS)
AUTOGRAFT AUGMENTATION FOR CHRONIC PATELLAR
TENDON RUPTURE
Technique for one-stage delayed reconstruction of patellar tendon.
A, Steinmann pin through transverse hole in patella is used for distal traction.
B, Proximally divided semitendinosus and gracilis tendons are placed through
holes and fixation wire is inserted.
C, With patella in normal position, fixation wire is secured and gracilis and
semitendinosus tendons are sutured to each other.

41. HAMSTRING AUTOGRAFT AUGMENTATION FOR
CHRONIC PATELLAR TENDON RUPTURE
A, Z-shortening of patellar tendon
and Z-lengthening of quadriceps
tendon.
B, Tack sutures are placed in tendons
after confirming patellar height
C&D, a transverse hole in patella is
made Semitendinosus and gracilis
tendons are harvested with tendon
stripper and sutured together.
E, Tendons are passed through
transverse hole in patella and sutured
together and also to underlying
patellar tendon.

42. POSTOPERATIVE CARE.
• At 2 weeks, the cast is removed for wound
evaluation and a new cylinder cast or locked brace
is applied.
• At 6 weeks, vigorous straight-leg raising with
weights and active flexion exercises are instituted.

43. Outcome
ACUTE QUADRICEPS TENDON REPAIR
• good to excellent results in 80% to 100% of
operatively treated quadriceps tendon ruptures
• Many different techniques of primary repair have
been described and no single technique has
demonstrated superiority.
• The only factor that has been associated with
inferior results is delay in timing of surgical repair of
greater than 2 to 3 weeks.

44. CHRONIC QUADRICEPS TENDON REPAIR
• Overall, less satisfactory than repair of an acute
tear
• Residual functional deficits present in most
patients.
• Some reported good to excellent results in patients
treated with their modification of the Codivilla
lengthening technique.
• More than half delayed repairs lost between 10 and
20 degrees of full active extension at final follow-up
in few studies.

45. ACUTE PATELLAR TENDON REPAIR
• Most series have reported between 70% and 100% good to
excellent results.
• The majority of patients who undergo early primary repair
achieve a functional range of motion and normal quadriceps
strength.
• Persistent quadriceps muscle atrophy commonly occurs, but
has not been correlated with loss of strength.
• No relationship has been demonstrated between the
configuration of the rupture, the method of repair, and clinical
outcome.
• An early repair within 2 to 3 weeks of injury is the only factor
that has been associated with better outcomes.
• In patients treated within 7 days ,96% had good to excellent
results.
• Patients with multiple injuries may have contributed to the
slightly lower success rate in some series.

46. CHRONIC OR NEGLECTED PATELLAR TENDON
RUPTURE
• A vey few series recommended preoperative
traction to overcome the contracted quadriceps
muscle so that the tendon ends could be re-
approximated.
• Results have generally been less satisfactory
compared to acute repair.