Patellar Tendon Repair

Why this approach — at MOS

Patellar tendon repair is an urgent procedure that is technically demanding in its simplest components: restoring correct patellar height. The patella must be positioned at its normal height — verified intraoperatively by comparison with the contralateral knee and by fluoroscopic measurement of the Insall-Salvati ratio — before the sutures are tied. If the repair is tensioned with the patella too high (patella alta) or too low (patella baja), the result is abnormal patellofemoral mechanics and poor function.

We use heavy non-absorbable sutures in Krackow locking configuration, with augmentation with fiber tape or heavy Ethibond cerclage when the repair seems at risk of gap formation during rehabilitation. The goal is a repair strong enough to permit early range-of-motion exercises — not just a static construct that holds the tendon but prevents any movement for weeks.

Patients who sustain patellar tendon rupture in Bethesda, Germantown, or anywhere in the Montgomery County area should seek evaluation immediately. Delay in repair is one of the most modifiable factors affecting outcome. We prioritize urgent assessment and scheduling for these injuries.

Who is a candidate?

Indications

• Complete patellar tendon rupture — confirmed by physical examination (inability to extend the knee, palpable gap below the patella, patella riding high on X-ray) and MRI
• All complete patellar tendon ruptures in patients medically fit for surgery — non-surgical management results in permanent extensor mechanism dysfunction

Contraindications

• Partial patellar tendon tear without extensor lag — may be managed conservatively with bracing
• Active infection (repair must be delayed until infection is cleared)
• Medical comorbidities making surgery unsafe

Conservative Treatment First

Partial patellar tendon tears — where some fibers remain intact and the patient retains some ability to extend the knee against gravity — may be managed with a brace in full extension for 6–8 weeks, followed by physical therapy. However, complete ruptures cannot heal reliably without surgery because the tendon ends retract and scar tissue forms rapidly, making delayed repair increasingly difficult. Surgical repair within the first 1–2 weeks of rupture provides the best outcomes; delay beyond 4–6 weeks significantly increases the technical difficulty and reduces the expected outcome of repair.

The procedure

What Is Patellar Tendon Repair?

Patellar tendon repair is surgery that reattaches the patellar tendon — the thick cord connecting the kneecap to the shinbone — after it ruptures. The patellar tendon is essential for extending (straightening) the knee: without it, the patient cannot lift the leg off the ground with the knee straight. Repair is urgent and should be performed within days of the rupture for the best results.

The extensor mechanism of the knee includes the quadriceps muscle, the quadriceps tendon, the patella (kneecap), and the patellar tendon. This chain transmits the force of quadriceps contraction to extend the knee. The patellar tendon connects the inferior pole of the patella to the tibial tubercle and is under enormous tensile load with every step, jump, and stair. Rupture most commonly occurs at the inferior patellar pole — where the tendon inserts into the bone — and is associated with a sudden violent quadriceps contraction against resistance, landing from a jump, or a direct blow.

Patellar tendon ruptures are most common in adults between 30 and 50 years of age and are associated with pre-existing patellar tendinopathy (degenerative weakening of the tendon), prior corticosteroid injections into the tendon, systemic conditions (systemic lupus, chronic kidney disease, hyperparathyroidism), and prior ACL reconstruction using patellar tendon graft. Without repair, the quadriceps cannot extend the knee and the patient cannot walk normally, climb stairs, or rise from a chair.

What Happens During Patellar Tendon Repair?

Patellar tendon repair is performed at the ambulatory surgery center under general or regional anesthesia. The patient is positioned supine. A tourniquet is applied. An incision is made over the front of the knee, exposing the patella and the patellar tendon.

The torn tendon ends are identified and the tissue quality is assessed. Any degenerate or frayed tendon tissue is debrided back to healthy tissue. Heavy non-absorbable sutures are woven through the tendon in a Krackow locking pattern — a technique that distributes suture load evenly and prevents cut-through. The sutures are then passed through tunnels drilled through the inferior pole of the patella (for proximal repairs at the patellar attachment) and tied over the anterior patellar cortex, pulling the tendon firmly back to bone. Alternatively, suture anchors can be used to avoid tunnel drilling.

Tendon-to-bone healing is augmented by roughening the bone surface. An augmentation suture — a heavy wire or tape passed from the tibial tubercle, around the patella, and back — may be used to protect the repair from excessive tension during the healing period while motion is restored.

The wound is closed and the knee is placed in a brace in extension. The patient goes home the same day.

Recovery timeline

Frequently Asked Questions