Extensor mechanism lesions after total knee arthroplasty

Sergio LoscosR1 COT

Hospital Universitari Sagrat Cor

▫Quadriceps tendon▫Periprosthetic patellar fractures▫Patellar tendon

Incidence Etiology Treatment

Extensor apparatus

Quadriceps tendon rupture

• Incidence: 0,1-1,1%

• Etiological factors:▫Traumatic episodes

(hyperflexion)

▫Technique Excessive bony resection Malalignment prosthesis Lateral release Patellar resurfacing Excision fat pad

▫ Individual Body mass index Osteoporosis DM, AR Metalosis

http://www.orthopaedicsone.com

Quadriceps tendon rupture• Treatment (surgery: 76,5%)

▫Partial: immobilization in knee extension 6-8 weeks

▫Complete or lag of 20º extension: surgery Acute

Transosseous fixation (1st election) Anchors prox. patella (few evidence) Direct suture (rerupture 40%)

Chronic: Reconstruction (graft) Autograft: semitendinosus/gracilis Allograft: Achilles tendon Synthetic: Dacron/Marlex

Suture nonabsorbible (Fiberwire, Ethibon, Arthrex, Naples, FL infull extension)

+ immobilization 6 weeks

Cons

erva

tive

Surg

ery

1.Quadriceps tendon rupture2. Suture weaved through quadriceps tendon using Krackow Technique #5 Ethibon 3. Parallel drill holes made through patella4. Sutures tied over bone bride - note that knee is in full-extension5. The repair is reinforced with #1 ethibon suture

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Transosseous fixation at patellaAcute quadriceps tendon rupture

Patellar tendon rupture• Incidence: 1%• Etiological factors: same as quadriceps• Treatment (surgery 98,6%), no conservative

▫ Acute Partial▫Direct suture (mid-substance tear)

Complete or inst. TTA/Patella▫ Transosseous fixation (TTA/Patella)▫Anchors (TTA/Patella distal)

▫ Chronic: Reconstruction (graft) Allograft: Achilles tendon with calcaneous bone block Gastrocnemius transposition Complete allograft extensor reconstruction Synthetic: Dacron/Marlex

http://www.orthopaedicsone.com

Supplemental autograft reconstruction

(semitendinosus/gracilis/tibialis anterior)

+

http://www.orthopaedicsone.com

Transosseous fixation at patella

Acute proximal patellar rupture

The patella tendon rupture from inferior pole of patella is identifiedHeavy, non-absorbable suture (#5 ethibond or fiberwire) is utilized for the repair. Parallel drill holes are made through the patella using 2.0-mm drill bit

Parallel drill holes made

through patella

Primary repair is attempted with suture tied over bone

bridge

http://z0mbie.host.sk/Patella-Fractures-and-Extensor-Mechanism-Injuries.html

Supplemental autograft reconstruction +

Chronic patellar ruptureAchilles tendon allograft reconstruction

http://www.orthopaedicsone.com

Osteotomy is performed below the tibial tubercle using

oscillating saw:rectangular/trapezoidal cavity 2.5 cm long by 1.5 cm wide by

1cm deep

The calcaneal bone is prepared to snugly fit into osteotomy site

Two 3.5-mm screws are utilized to stabilize allograft

into the tibia.The Achilles tendon is draped over the native

patella tendon, patella and quadriceps tendon. The allograft tendon is then

sutured the native extensor mechanism

Final repair using non-absorbable

suture

Periprosthetic patellar fractures• Incidence: 1%

• Etiological factors:▫Technique

Excision fat pad Lateral release Patellar resurfacing

▫Gender (men)▫Traumatic episodes

• Classification (Ortiguera and Berry)▫Type I▫Type II: extensor rupture▫Type III: loose component

z0mbie.host.sk

Periprosthetic patellar fractures• Treatment (surgery: 28,1% cases)

▫Type I: immobilization (excellent results)

▫Type II: extensor apparatus repair + internal fixation/patellectomy

▫Type III Good stock bone: revision Poor stock bone: component removal/patellectomy

Cons

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Surg

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ConclusionQuadriceps tendon rupture Patellar tendon rupture Periprosthetic patellar fx.

Partial Complete or lag ext. > 20º

Conservative (immobilization)

Surgery Surgery

Type I Type II/III

SurgeryConservative

(immobilization )

Acute Chronic

Repair•Transosseous fixation patella•Anchors prox. patella•Direct suture

Reconstruction:•Autograft•Allograft•Synthetic

Acute Chronic

• Partial: direct suture• Complete: - Transosseous fixation (TTA/patella) - Anchors (TTA/ dist.patella)

Supplemental autograft reconstruction (semitendinosus/gracilis/tibialis anterior)

+

Reconstruction:•Autograft•Allograft (Achilles) •Synthetic