DEFINITION

Quadriceps tendon ruptures result in disruption of the fibers of this tendon, thereby disrupting the extensor mechanism of the knee.

Injury is prevalent in patients older than 40 years old and is more common in men.

Ruptures usually occur transversely through the tendon at a pathologic area approximately 2 cm proximal to the superior pole of the patella, and then progress obliquely into the medial and lateral retinacula based on the amount and duration of force.

Ruptures can occur at the bone-tendon interface (older patients) or at the midtendinous or musculotendinous area (younger patients).10

Unilateral ruptures are more common; bilateral ruptures may occur due to a predisposition from an underlying systemic condition.

Acute repair of the tendon provides a higher rate of return of function.

 

 

ANATOMY

 

The quadriceps tendon consists of the coalescence of the rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius, 3 to 5 cm proximal to the patella, and inserts into the superior pole of the patella.

 

 

The quadriceps tendon averages 8 mm in thickness and 35 mm in width.13 Normal quadriceps tendon layers include three layers:

 

 

Superficial layer, which originates from the posterior fascia of the rectus femoris. Deep layer, which originates from the anterior fascia of the vastus intermedius.

 

Middle layer, which originates from the deep fascia separating the vastus medialis and lateralis from the vastus intermedius.13

 

The tendon receives its blood supply from multiple contributions: branches of the lateral circumflex femoral artery, the descending geniculate artery, and the medial and lateral superior geniculate arteries.9

 

The distribution of the blood supply in the tendon is asymmetric.9

 

 

 

The superficial tendon is well vascularized from the musculotendinous junction to the patella. The deep portion of the tendon has an oval avascular area.

PATHOGENESIS

 

Quadriceps tendon rupture typically occurs through a site of pathologic degeneration in the tendon caused by repetitive microtrauma.3,4

 

Rupture is the result of eccentric contraction of the extensor mechanism against a sudden load of body weight

with the foot planted and the knee flexed.8

 

 

Rupture can be due to trauma, use of corticosteroids, and systemic diseases (gout, pseudogout, systemic lupus erythematosus, rheumatoid arthritis, renal failure, hyperparathyroidism, diabetes mellitus).5 Fluoroquinolone antibiotics (ciprofloxacin) have also contributed to tendon weakness.

 

Prolonged immobilization weakens the tendon, thereby increasing risk of rupture.

 

 

Although rare, ruptures can occur following total knee arthroplasty or aggressive release of lateral retinaculum. Bilateral ruptures typically are the result of systemic medical conditions.

NATURAL HISTORY

 

 

Unrepaired quadriceps tendon rupture can lead to chronic extensor lag and weakness. Long-term rupture may lead to quadriceps fibrosis as well as patella baja.

 

Partial tears can be treated nonoperatively based on the integrity of the extensor mechanism.

 

HISTORY AND PHYSICAL FINDINGS

 

 

Immediate pain, occasional swelling, subcutaneous hematoma Occasionally hears or feels a “pop”

 

Inability to bear weight

 

Sensation of knee “giving away” or buckling

 

 

Preexisting pain and symptoms related to quadriceps tendon (tendinosis) prior to injury Effusion can be indicative of hemarthrosis.

 

Loss of extension (straight-leg raise) indicates lack of continuity of the extensor mechanism (Note: ability to extend knee with a tendon rupture may be due to intact retinacula).

 

Suprapatellar gap (a soft tissue defect proximal to the superior pole of the patella) is indicated by loss of continuity of the extensor mechanism at the quadriceps tendon attachment.

 

Patella baja (patella of the injured knee more inferior than the contralateral knee) is indicated by loss of proximal extensor mechanism.2

 

 

Incomplete rupture—knee may extend when fully supine, however unable to extend from a flexed position Chronic rupture—easily missed

 

Difficulty ambulating

 

Pain—may be nonspecific, typically anterior knee

 

 

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

P.536

 

Plain radiographs (especially lateral view) may demonstrate bony avulsion fractures at the superior patella or soft tissue calcific depositions in chronic tendinosis.

 

 

 

Tooth sign6: on Merchant view, vertical ridging of osteophytes at the quadriceps tendon attachment site Ultrasound, although operator dependent and not as specific, may demonstrate a discrete break in the tendon

with abnormal overlying soft tissue.

 

Arthrography is invasive; however, it is positive with extravasation of contrast dye from the suprapatellar pouch and along the sheath of the tendon.1

 

Magnetic resonance imaging (MRI) remains the gold standard in diagnosing partial and complete quadriceps tendon ruptures in addition to associated soft tissue injuries.

 

 

Notable findings include focal tendon discontinuity, increased signal in the tendon, wavy patella tendon as well as possible preexisting pathology.

 

DIFFERENTIAL DIAGNOSIS

 

 

 

 

Patella tendon rupture Quadriceps tendon rupture Patella femoral contusion Cartilage contusion

 

 

Neural injury Patellar fracture

NONOPERATIVE MANAGEMENT

 

Patients with partial quadriceps tear, but functionally intact extensor mechanism, may be treated nonoperatively.

 

For the first 6 weeks, immobilize knee in extension to assist with tendon healing and maintenance of tendon length.

 

 

 

This can be done with a long-leg brace locked in extension or with a long-leg cylinder cast. Patients should initially be non-weight bearing with crutches.

 

Patient may begin isometric straight-leg raises.

 

In the next phase, regaining flexion is emphasized, and the brace is unlocked to allow restoration of normal gait.

 

 

The patient is advanced to full weight bearing once stable range of motion is demonstrated.

 

In the last phase, strengthening is emphasized.

 

Patients can return to activity once full range of motion and strength are restored, typically in 4 months.

 

SURGICAL MANAGEMENT

 

All complete tendon ruptures should be repaired acutely to restore extensor function.

 

Any partial rupture that has progressed to a complete rupture should also be repaired as soon as diagnosed.

 

Preoperative Planning

 

Review all imaging studies.

 

Confirm any associated injuries that will require surgical attention.

 

Early treatment decreases risk of tendon scarring and loss of tissue excursion.

 

Chronic injury may require additional allograft tissue for reconstruction.

 

Positioning

 

 

The patient should be placed supine on the operating table with all bony prominences padded. A bump under the ipsilateral hip can prevent external rotation of the operative leg.

 

If an examination under anesthesia is necessary, care must be taken not to convert a partial tear to a complete rupture.

 

Avoid use of tourniquet as this may inhibit excursion of tendon tissue.

 

Approach

 

A midline patella incision, centering over the bone-tendon interface, provides access to the tendon repair in addition to evaluation and repair of the medial and lateral retinacula (FIG 1).

 

 

 

 

FIG 1 • Planning for a midline longitudinal incision of the knee.

 

TECHNIQUES

• Acute Tendon Repair at the Tendon-Bone Interface

Tendon Preparation

A straight, full-thickness, 10-cm midline incision is made, centered over the bone-tendon interface. Retract superficial layers to examine the deep tissue layers (TECH FIG 1A).

Irrigate hematoma.

Evaluate medial and lateral retinacula (TECH FIG 1B).

Débride tendon edge of necrotic and degenerative tissue to normal-appearing healthy tendon tissue

 

(TECH FIG 1C,D).

 

Confirm ability to reapproximate tendon to bone without undue tension (TECH FIG 1E,F).

Suturing

 

Using no. 2 or no. 5 nonabsorbable suture and beginning near the lateral free edge of the tendon, a continuous running-type stitch (Krackow stitch, Mason-Allen stitch) is placed, exiting back at the free end of the tendon (TECH FIG 2A).

 

Repeat for the medial aspect of the tendon.

 

When completed, there should be four equal strands of sutures exiting the free tendon edge (TECH FIG 2B,C).

 

A trough of fresh bone is made at the superior pole of the patella to assist with tendon reattachment. The trough should not be placed too anteriorly to avoid patellar tilt.

 

Create three longitudinal drill holes 1 to 1.5 cm apart, exiting at inferior pole of the patella.

 

 

P.537

 

 

 

TECH FIG 1 • Evaluating deep tissue layers (A) and medial and lateral retinacula (B). C. Patella retracted inferiorly, demonstrating tear. D. Alice clamps on quadriceps tendon demonstrating mobility of soft tissue. E. Reapproximating quadriceps tendon to the patella. F. Confirmation of tension-free reapproximation of tendon repair.

 

 

Using a suture passer and beginning at the inferior pole of the patella, each of the four strands of suture is brought longitudinally through the patella (TECH FIG 2D,E).

 

Holding the sutures provisionally, knee flexion is evaluated for patellar tracking and rotation.

 

Reduce the tendon to the superior pole of the patella, and tie sutures with the knee in full extension (TECH FIG 2F).

 

Bury knots posterior to the patellar tendon at the inferior pole.

 

 

 

TECH FIG 2 • A. Placement of continuous running stitch, beginning laterally and exiting back at the free edge of the tendon. B. Four sutures exiting the free edge of the quadriceps tendon. C. Close-up of the four exiting sutures. D. Four sutures from the free edge of the quadriceps tendon brought inferiorly through three longitudinal drill holes in the patella. (continued)

 

 

To complete the repair, use no. 0 absorbable sutures in interrupted fashion to repair the medial and lateral retinacula (TECH FIG 2G).

 

Reevaluate patellar positioning, tracking, and tensioning of the repaired tendon.

 

The position of knee flexion at which tension begins on the repair should be noted because this will determine the amount of maximum knee flexion allowed in postoperative rehabilitation.

 

P.538

 

 

 

TECH FIG 2 • (continued) E. The center two sutures exit through a central drill hole. F. Sutures are secured with their continuous loop mate—first the lateral set followed by the medial set. G. Repair of lateral and medial retinacula.

• Suture Anchors at Tendon-Bone Interface

   

   

  Follow same technique as previously discussed on Tendon Preparation. Create bony trough at superior pole of patella.

   

  Using a small drill bit from the instrument set of suture anchors, make three pilot holes, first starting in the center followed by one at the medial third and another at the lateral third of patella edge.11

   

  Place suture anchors with their respective no. 2 suture in each of three pilot holes, confirming eyelet of anchor is inferior to cortical bone edge.

   

  Begin with central sutures from the central suture anchor.

   

  Make one end of suture longer as this will be used to sew tendon in a continuous running-type stitch, ending back at the free end of the tendon (TECH FIG 3A).

   

   

   

  TECH FIG 3 • A. Placement of three suture anchors: central suture continuous running stitch and tied to itself over anchor eyelet, lateral suture completed running stitch and not yet tied, and medial sutures not yet sewn through tendon edge. B. Placement of three suture anchors with each respective suture sewn in continuous running fashion and tied to itself over eyelet of each suture anchor.

   

   

  Use a free needle, thread long tail of no. 2 suture and sew tendon as listed earlier on Suturing.

   

  Tie both ends of suture together around anchor eyelet, burying knot inferior to patella tendon at the superior pole (TECH FIG 3B).

   

   

   

  Advantages of technique Minimal soft tissue dissection Shorter longitudinal incision

   

  Limited exposure not involving distal pole of patella

   

   

  Decreased wound healing concerns with smaller incision Knots easily buried

   

  Progressive rehabilitation11

   

  Consistent load-to-failure suture anchor characteristics over traditional suture techniques via drill holes11

   

  Possible complications of technique

   

  Anchor pullout in bone of weaker quality

   

   

   

  Suture abrasion at eyelet of anchor7 Patellar fracture

   

• Acute Tendon Repair at Musculotendinous and Midtendinous Areas

   

   

  A straight, full-thickness, 10-cm midline incision is made centered over the bone-tendon interface. Irrigate hematoma.

   

   

  Débride tendon edges of necrotic and degenerative tissue to normal-appearing healthy tendon. Confirm the ability to reapproximate tendon ends without undue tension (TECH FIG 1E,F).

   

  P.539

   

  Nonabsorbable no. 2 or no. 5 sutures are used for a continuous running stitch to reapproximate both proximal and distal free lateral edges of the tendon (TECH FIG 4A).

   

  Procedure is repeated for the proximal and distal medial edges of the tendon.

   

   

   

  TECH FIG 4 • A. Placement of two sets of continuous running stitches laterally and medially in both the proximal and distal stumps. B. Alignment following tying of four exiting proximal and distal sutures.

   

  Provisionally reapproximate tendon edges by tensioning sutures together and evaluating knee flexion for patellar tracking and rotation.

   

  Tie sutures together with the knee in full extension, making sure not to overtension or overlap the reattachment (TECH FIG 4B).

   

  If necessary, use no. 0 nonabsorbable suture to reinforce repair with interrupted figure-8 stitches.

   

  To complete the repair, use no. 0 absorbable suture in interrupted fashion to repair the medial and lateral retinacula.

   

  Reevaluate patellar positioning, tracking, and tensioning of the repaired tendon.

   

  The position of knee flexion at which tension on the repair begins should be noted because this will determine the amount of maximum knee flexion allowed in postoperative rehabilitation.

• Repair of Chronic Tendon Rupture

 

 

Chronic ruptures typically present with scar tissue in addition to shortening. Use same longitudinal midline incision.

 

 

Mobilize tendon by releasing adhesions to the surrounding soft tissues, skin, and underlying femur. Débride tendon edges to healthy tissue, and remove scar tissue from the tendon gap.

 

If the tendon can be easily reapproximated, repair similarly to an acute repair.

 

If the tendon cannot be reapproximated without undue tension, a reinforcement (Scuderi technique) or lengthening (Codivilla technique) procedure is indicated.

Scuderi Technique

 

 

 

Débride tendon edges to healthy tissue, and remove scar tissue from the tendon gap (TECH FIG 5A). Reapproximate tendon edges and repair with interrupted no. 0 nonabsorbable sutures (TECH FIG 5B). An inverted V is incised through the full thickness of the quadriceps tendon, with the base of the V ending approximately 1 cm proximal to the rupture (TECH FIG 5C).12

 

The apex of the V is folded distally and sutured in place (TECH FIG 5D).12

 

This technique can also be used for acute repairs.10

 

 

P.540

 

 

 

TECH FIG 5 • A. Proximal tendon edge following débridement of scar tissue. B. Apposition and repair of quadriceps tendon to distal quadriceps stump. C. Incision of inverted V through full thickness of proximal quadriceps tendon. D. Apex of V folded distally and secure in place.

Codivilla Technique

 

Débride tendon edges to healthy tissue, and remove scar tissue from the tendon gap (TECH FIG 6A).

Reapproximate tendon edges and repair with interrupted no. 0 nonabsorbable sutures (TECH FIG 6B).

An inverted V is incised through the full thickness of the quadriceps tendon, with the base of the V ending approximately 1 cm proximal to the rupture (TECH FIG 6C).

 

TECH FIG 6 • A. Following débridement of tendon to healthy tissue, excess tension is placed on tendon for reapproximation. B. Reapproximate quadriceps edges and secure with sutures. C. Incision of inverted V through full thickness of quadriceps tendon in order to lengthen the tendon as it is reapproximated. D. Apex of V folded distally and secured as proximal tendon is closed side to side, enabling lengthening and repair of tendon without excess tension.

The apex of the V is folded distally and sutured in place (TECH FIG 6D).

The proximal length of the V is closed side to side longitudinally with interrupted no. 0 nonabsorbable sutures.

If further augmentation is required, autograft or allograft of fascia lata, semitendinosus, or gracilis tendons can be used.

 

 

 

PEARLS AND PITFALLS
	Proper diagnosis ▪ Complete history and physical examination Review of radiographs and MRI     Medial or lateral patellar tilt ▪ Anatomic and balanced repair of medial and lateral retinacula     Excessive patellofemoral ▪ Avoid excessive shortening of the extensor mechanism. contact stress     Patella baja ▪ Avoid overtightening of the tendon repair.     Superior patellar tilt ▪ Avoid anterior reattachment of tendon to the superior pole of the patella.     Tourniquet ▪ Use of tourniquet can bind quadriceps tissue and limit tendon mobility. If used, first pull tendon distally prior to placing tourniquet at most proximal position.

 

 

 

 

POSTOPERATIVE CARE

P.541

 

A long-leg hinged brace with knee locked in full extension is used for 6 weeks (a long-leg cast may be used for unreliable or noncompliant patients).

 

The patient is instructed to observe toe-touch weight bearing for the first 1 to 2 weeks followed by weight bearing as tolerated with crutches during the remainder of the 6-week period.

 

Compliant patients can begin range-of-motion exercises within the parameters of the hinged brace, which usually is set from 0 to 90 degrees.

 

 

The flexion range is the number attained intraoperatively following complete repair to determine when tension begins stressing the repair.

 

At 6 weeks, the long-leg hinged brace is unlocked gradually to full flexion.

 

Once 90 degrees of knee flexion is achieved and quadriceps strength is sufficient, use of the brace can be discontinued.

 

As function returns, the patient may advance bearing weight without crutches.

 

Therapy is continued to achieve full range of motion and quadriceps strength.

OUTCOMES

Following acute quadriceps tendon repair and rehabilitation, most patients achieve normal gait, regain full quadriceps strength, and regain satisfactory flexion (some knee flexion may be lost owing to tendon shortening during débridement of necrotic tissue for repair).5,10

Chronic repairs can be associated with persistent quadriceps weakness and extensor lag. Older patients often have preexisting patellofemoral chondromalacia and degeneration, possibly exacerbating anterior knee pain.4

Recurrence of tendon rupture is rare.

Nearly half of all patients are unable to return to their preinjury activity level.5

 

 

COMPLICATIONS

Loss of full knee flexion

Residual weakness of quadriceps Infection

Wound complications Patellar tilt

Excessive patellofemoral contact stress Patella baja

Residual extensor lag

 

Rerupture of tendon

 

 

REFERENCES

1. Aprin H, Broukhim B. Early diagnosis of acute rupture of the quadriceps tendon by arthrography. Clin Orthop 1985;(195):185-190.

    

    

2. Insall J, Salvati E. Patella position in the normal knee joint. Radiology 1971;101:101-104.

    

    

3. Kannus P, Józsa L. Histopathological changes preceding spontaneous rupture of a tendon. J Bone Joint Surg 1991;73:1507-1525.

    

    

4. Kelly DW, Carter VS, Jobe FW, et al. Patellar and quadriceps tendon ruptures—jumper's knee. Am J Sports Med 1984;12:375-380.

    

    

5. Konrath GA, Chen D, Lock T, et al. Outcomes following repair of quadriceps tendon ruptures. J Orthop Trauma 1998;12:273-279.

    

    

6. Kuivila TE, Brems JJ. Diagnosis of acute rupture of the quadriceps tendon by magnetic resonance imaging. Clin Orthop 1991;262:236-241.

    

    

7. Lighthart WA, Cohen DA, Levine RG, et al. Suture anchor versus suture through tunnel fixation for quadriceps tendon rupture: a biomechanical study. Orthopedics 2008;31:1-6.

    

    

8. McLaughlin HL, Francis KC. Operative repair of injuries to the quadriceps extensor mechanism. Am J Surg 1956;91:651-653.

    

    

9. Petersen W, Stein V, Tillmann B. BlutgefaBversorgung der Quadrizepssehne [Blood supply of the quadriceps tendon]. Unfallchirurg 1999;102:543-547.

    

    

10. Rasul AT, Fischer DA. Primary repair of quadriceps tendon ruptures. Results of treatment. Clin Orthop Relat Res 1993;(289):205-207.

     

     

11. Richards DP, Barber FA. Repair of quadriceps tendon ruptures using suture anchors. Arthroscopy 2001;18:556-559.

     

     

12. Scuderi C, Schrey EL. Ruptures of the quadriceps tendon. Arch Surg 1950;61:42-54.

     

     

13. Zeiss J, Saddemi SR, Ebraheim NA. MR imaging of the quadriceps tendon: normal layered configuration and its importance in cases of tendon rupture. Am J Roentgenol 1992;159:1031-1034.