Krishna Mallik
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 more 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).9
Unilateral ruptures are more common; bilateral ruptures may occur because of 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, about 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.11
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.11
The tendon recieves its blood supply from multiple contributions: branches of the lateral cicumflex femoral artery, the descending geniculate artery, and the medial and lateral superior geniculate arteries.8
The distribution of the blood supply in the tendon is asymmetric8:
The superficial tendon vascular supply is complete 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.4,5
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.7
Rupture can be due to trauma, use of corticosteroids, and systemic diseases (eg, gout, pseudogout, systemic lupus erythematosus, renal failure, hyperparathyroidism, diabetes mellitus).2
Fluoroquinolone antibiotics (eg, ciprofloxacin) also have contributed to tendon weakness.
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.
PATIENT HISTORY AND PHYSICAL FINDINGS
Immediate pain, occasional swelling, subcutaneous hematoma
Occasionally hears or feels a “pop”
Inability to bear weight
Pre-existing pain and symptoms related to quadriceps tendon (tendinitis) 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 may be due to intact retinacula).
Suprapatella gap (ie, 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 (ie, patella of the injured knee more inferior than the contralateral knee) is indicated by loss of proximal extensor mechanism.
IMAGING AND OTHER DIAGNOSTIC STUDIES
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's view, vertical ridging of osteophytes at the quadriceps tendon attachment site
Ultrasound, while 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 tendon sheath of the tendon.1
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 pre-existing pathology.
DIFFERENTIAL DIAGNOSIS
Patella tendon rupture
Quadriceps tendon rupture
Patella femoral contusion
Cartilage contusion
Neural injury
NONOPERATIVE MANAGEMENT
Patients with partial quadriceps tear may be treated nonoperatively.
For the first 6 weeks, the knee is immobilized 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 be non–weight bearing with crutches.
In the first 6 weeks, the 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.
In the last phase, strengthening is emphasized.
Patients can return to activity once full range of motion and strength are restored, usually 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.
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.
Approach
A midline patella incision, centering over the bone–tendon interface, provides access to the tendon repair as well as evaluation and repair of the medial and lateral retinaculae (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 10-cm midline incision is made, centered over the bone–tendon interface.
The superficial layers are retracted to examine the deep tissue layers (TECH FIG 1A).
Hematoma is irrigated.
The medial and lateral retinaculae are evaluated (TECH FIG 1B).
The tendon edge of necrotic and degenerative tissue is débrided to normal-appearing healthy tendon tissue (TECH FIG 1C,D).
Ability to reapproximate tendon ends without undue tension (TECH FIG 1E,F) is confirmed.
Suturing
Using no. 2 or no. 5 nonabsorbable suture, beginning near the lateral free edge of the tendon, a continuous running-type stitch (eg, Krackow stitch, Mason-Allen stitch) is placed, exiting back at the free end of the tendon (TECH FIG 2A).
This is repeated 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 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.
Three longitudinal drill holes, 1 to 1.5 cm apart, are placed, exiting out of the inferior pole of the patella.
Using a suture passer, 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 with patellar tracking and rotation.
The tendon is reduced to the superior pole of the patella, and the sutures are tied with the knee in full extension (TECH FIG 2F).
Knots are buried behind the patellar tendon at the inferior pole.
To complete the repair, no. 0 nonabsorbable sutures are used in interrupted fashion to repair the medial and lateral retinacula (TECH FIG 2G).
Patellar positioning, tracking, and tensioning of the repaired tendon are evaluated.
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.
TECH FIG 1 • Evaluating the deep tissue layers (A) and the medial and lateral retinacula (B). C. Patella retracted inferiorly, demonstrating tear. D. Alice clamps on quadriceps tendon demonstrating mobility of soft tissue. E.Reapproximating the quadriceps tendon to the patella. F. Confirmation that there is no excess tension on reapproximation for tendon repair.
TECH FIG 2 • A. Placement of a 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. 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.
ACUTE TENDON REPAIR AT MUSCULOTENDINOUS AND MIDTENDINOUS AREAS
A straight 10-cm midline incision is made centered over the bone–tendon interface.
Hematoma is irrigated.
The tendon edge of necrotic and degenerative tissue is débrided down to normal-appearing healthy tendon tissue.
Ability to reapproximate tendon ends without undue tension (see Tech Fig 1E,F) is confirmed.
No. 2 or no. 5 nonabsorbable sutures are used for a continuous running stitch to reapproximate both proximal and distal free lateral edges of the tendon (TECH FIG 3A).
Procedure is repeated for the proximal and distal medial edges of the tendon.
Tendon edges are reapproximated by provisionally tensioning sutures together and evaluating knee flexion with patellar tracking and rotation.
The sutures are tied together with the knee in full extension, making sure not to overtension or overlap the reattachment (TECH FIG 3B).
No. 0 nonabsorbable suture is used, if necessary, to reinforce repair with interrupted figure 8 stitches.
To complete the repair, no. 0 nonabsorbable suture is used in interrupted fashion to repair the medial and lateral retinacula.
Patellar positioning, tracking, and tensioning of the repaired tendon are evaluated.
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.
TECH FIG 3 • A. Placement of two sets of continuous running stitches laterally and medially in both the proximal and distal stumps. B. Alignment of four exiting proximal and distal sutures that makes it possible to secure them to each other as tension is applied on the untied suture sets.
CHRONIC TENDON REPAIR
Chronic ruptures have scar tissue present in addition to shortening.
A longitudinal midline incision is used.
The tendon is mobilized by releasing adhesions to the surrounding soft tissues, skin, and underlying femur.
The tendon edges are débrided down to healthy tissue, and scar tissue is removed from the tendon gap.
If the tendon can be reapproximated, it is repaired similarly to an acute repair.
If the tendon cannot be apposed without undue tension, a reinforcement (Scuderi technique) or lengthening (Codivilla technique) procedure is indicated.
Scuderi Technique
The tendon edges are débrided to healthy tissue, and scar tissue is removed from the tendon gap (TECH FIG 4A).
The quadriceps edges are reapproximated and repaired together with interrupted no. 0 nonabsorbable sutures (TECH FIG 4B).
An inverted V is incised through the full thickness of the proximal quadriceps tendon, with the base of the V ending approximately 1 cm proximal to the rupture (TECH FIG 4C).
The apex of the V is folded distally and sutured in place (TECH FIG 4D).
This technique also can be used for acute repairs.10
Codivilla Technique
The tendon edges are débrided to healthy tissue, and scar tissue is removed from the tendon gap (TECH FIG 5A).
The quadriceps edges are apposed and repaired together with interrupted no. 0 nonabsorbable sutures (TECH FIG 5B).
An inverted V is incised through the full thickness of the proximal quadriceps tendon, with the base of the V ending approximately 1 cm proximal to the rupture (TECH FIG 5C).
The apex of the V is folded distally and sutured in place (TECH FIG 5D).
The proximal length of the V is closed longitudinally with interrupted no. 0 nonabsorbable sutures.
If further augmentation is required, autograft or allograft of fascia lata, semitendinosus and gracilis tendons, or Mersilene tape can be used.
TECH FIG 4 • 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.
TECH FIG 5 • A. Following débridement of tendon to healthy tissue, excess tension is placed on the tendon for reapproximation. B. Reapproximate the quadriceps edges and secure with sutures. C. Incision of inverted V through full thickness of quadriceps tendon for the purpose of lengthening the tendon as it is reapproximated. D. Apex of V folded distally and secured, as proximal tendon is closed to each other to allow for lengthening and repair of tendon without excess tension.
POSTOPERATIVE CARE
A long-leg hinged brace with the knee locked in full extension is used for 6 weeks (a long-leg cast may be used for unreliable 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 (ROM) exercises within the parameters of the hinged brace, which usually is set from 0 to 90 degrees.
This flexion amount is the value attained interoperatively 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.
The patient may advance bearing weight without crutches as function returns.
Therapy is continued to achieve full ROM 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).2,9
Chronic repairs are associated with persistent quadriceps weakness and extensor lag.
Older patients often have pre-existing patellafemoral chondromalacia and degeneration, often causing exacerbation of anterior knee pain.5
Recurrence of tendon rupture is rare.
Nearly half of all patients are unable to return to their preinjury activity level.2
COMPLICATIONS
Loss of full knee flexion
Residual weakness of quadriceps
Infection
Wound complications
Patella tilt
Excessive patellofemoral contact stress
Patella baja
Residual extensor lag
REFERENCES
1. Aprin H, Broukhim B. Early diagnosis of acute rupture of the quadriceps tendon by arthrography. Clin Orthop 1985;5:185–190.
2. Gregory K, Chen D, Lock T, et al. Outcomes following repair of quadriceps tendon ruptures. J Orthop Trauma 1998;12:273–279.
3. Insall J, Salvati E. Patella position in the normal knee joint. Radiology 1971;101:101–104.
4. Kannus P, Jozsa L. Histopathological changes preceding spontaneous rupture of a tendon. J Bone Joint Surg 1991;73:1507–1525.
5. Kelly DW, Carter VS, Jobe FW, et al. Patellar and quadriceps tendon ruptures—jumper's knee. Am J Sports Med 1984;12:375–380.
6. Kuivila TE, Brems JJ. Diagnosis of acute rupture of the quadriceps tendon by magnetic resonance imaging. Clin Orthop 1991;262:236–241.
7. McLaughlin HL, Francis KC. Operative repair of injuries to the quadriceps extensor mechanism. Am J Surg 1956;91:651–653.
8. Petersen W, Stein V, Tillmann B. Blood supply of the quadriceps tendon (BlutgefaBversorgung der Quadrizepssehne). Unfallchirurg 1999; 102:543–547.
9. Rasul AT, Fischer DA. Primary repair of quadriceps tendon ruptures. Clin Orthop Rel Res 1993;289:205–207.
10. Scuderi C, Schrey EL. Ruptures of the quadriceps tendon. Arch Surg 1950;61:42–54.
11. 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.