AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The patellar tendon ruptures relatively infrequently. However, the complications of an untreated rupture to the extensor mechanism can be extremely disabling. Surgical intervention allows for excellent recovery of motion and strength, provided that the injury is diagnosed in a timely fashion and repaired immediately. The focus of this article is acute patellar tendon ruptures, especially those associated with acute sports-related injuries. Patellar tendon ruptures also can occur as a complication of total knee arthroplasty, anterior cruciate ligament (ACL) reconstruction using the patellar tendon as an autograft,¹ or excision of chronic tendinosis. However, the etiology and treatment in these circumstances are beyond the scope of this article.

Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Arthroplasty
CME Tendinopathy -- From Basic Science to Treatment
Specialty Site Orthopaedics
Orthopaedics News

Related eMedicine topics:
Total Knee Arthroplasty
Complications of Total Knee Arthroplasty
Anterior Cruciate Ligament Pathology

History of the Procedure

In the past, the surgical technique for acute rupture of the patellar tendon was primary suture repair. Augmentation of the repair was believed to be necessary and was achieved using a cerclage of wire, suture, or autogenous graft such as the semitendinosus in order to reinforce the repair. Routinely, the knee was kept locked in extension for up to 6 weeks to prevent undue stress on the repair.

Earlier and more aggressive rehabilitation techniques are now available. Krakow introduced a novel interlocking stitch technique,² and Marder and Timmerman demonstrated that repair alone is equally as durable without augmentation.³

Problem

The patellar tendon serves as the distal extent of the quadriceps insertion. Rupture of the patellar tendon usually occurs at the osseotendinous junction and causes complete derangement of the knee extensor mechanism. This is a disabling injury in the active person, resulting in an inability to actively obtain and maintain full knee extension. If the tendon does not heal properly and at the correct length and tension, knee range of motion and strength can be altered significantly, leading to early fatigue, patellofemoral pain, and, possibly, instability, which can thereby prevent return to preinjury status. Immediate surgical repair is recommended for optimal return of knee function and power.

Frequency

The true incidence of patellar tendon rupture is not known, but it is observed less frequently than rupture of the quadriceps tendon and usually occurs in those younger than 40 years. It is the third most common injury to the extensor mechanism of the knee, following patellar fracture and quadriceps tendon rupture.^{4, 5}

Etiology

Patellar tendon rupture often occurs in the setting of long-standing patellar tendon irritation. The rupture is the final result of chronic tendon degeneration due to repetitive microtrauma. Histopathologically, ruptured tendons studied by Kannus et al demonstrated changes consistent with chronic inflammation and degeneration.⁶

Ruptures also have been known to occur after local injection of corticosteroid near the inferior pole of the patella as treatment for patellar tendinitis (ie, jumper's knee). This complication, first reported in 1969 by Ismail et al⁷ and later elucidated by Kennedy et al,⁸ is probably a result of steroid-induced breakdown of collagen organization and strength. In a series by Kelly et al, nearly 60% of patients who sustained patellar tendon ruptures had received an average of 2-3 steroid injections around the patellar tendon prior to rupture.⁹

Patellar tendon rupture is usually unilateral and is the result of a traumatic athletic injury. The typical mechanism is a sudden eccentric contraction of the quadriceps, usually with the foot planted and the knee flexed as the person falls. However, in the setting of systemic inflammatory disease, diabetes mellitus, or chronic renal failure, bilateral ruptures can occur with lower-energy stress.^{10, 11} Additionally, patellar tendon ruptures can result form a posterior knee dislocation.¹² 

Systemic disorders are related to an increased incidence of tendon ruptures. Pritchard et al found that tendon ruptures in systemic lupus erythematosus (SLE) appear to be associated with extended disease duration, chronic corticosteroid therapy, evidence of steroid-induced musculoskeletal complications, minimal disease activity at the time of rupture, and deforming hand arthropathy.¹³

Inflammatory changes have been noted at the site of rupture in patients with SLE,¹⁴ amyloid deposition has been noted at the site in patients with chronic renal failure undergoing dialysis,¹⁵ and elastosis has been noted in patients with chronic acidosis.¹⁶

Anatomically, the patellar tendon tends to tear in the mid substance in patients with systemic disease, rather than at the osseotendinous junction, as typically occurs in acute traumatic injury. After a tear of the mid substance, tendon repair and rehabilitation can be especially difficult and is exacerbated further by the preexisting comorbid condition.

Patellar tendon ruptures also can occur following surgery for total knee arthroplasty, procedures using the central third of the patellar tendon as an autograft, or excision of patellar tendinosis.

Related eMedicine topics:
Chronic Renal Failure
Diabetes Mellitus, Type 1
Diabetes Mellitus, Type 2
Systemic Lupus Erythematosus
Total Knee Arthroplasty
Knee Dislocations

Pathophysiology

Unilateral traumatic ruptures of the patellar tendon tend to occur when a violent contraction of the quadriceps is resisted by the flexed knee (eg, while landing after a jump). The estimated force required to disrupt the extensor mechanism has been reported to be as high as 17.5 times body weight. In the flexed knee position, the patellar tendon sustains greater stress than the quadriceps tendon, and the tensile load is much higher at the insertion sites than in the mid substance of the tendon. Therefore, the patellar tendon most commonly ruptures near its proximal end, off the inferior pole of the patella.

Since considerable force is needed to rupture a healthy tendon, it is likely that ruptures occur in areas of preexisting disease.

Clinical

History, physical examination, and standard radiographs typically are adequate for making a diagnosis of acute patellar tendon rupture.

Disruption of the patellar tendon is associated with immediate, disabling pain. Acute rupture frequently results in an immediate 'pop' or tearing sensation. The patient usually notes immediate swelling and difficulty rising and bearing weight following the injury.

On physical examination, diffuse swelling in the anterior knee with ecchymosis, hemarthrosis, and patella alta is observed. Tenderness exists along the anterior knee and retinacula, and a defect at the level of the rupture is usually palpable (Image 1), although significant swelling can make this difficult to appreciate initially. The patella may also feel proximally displaced, compared with the contralateral side.

The patient is usually unable to bear weight, especially in a single-leg stance, and has a tense hemarthrosis. With a tendon rupture extending through the medial and lateral retinacula, active extension is completely lost, and the patient is unable to maintain the passively extended knee against gravity. If the rupture involves only the tendon and the retinacular fibers remain intact, some extension is possible, although an extensor lag is noted.

Occasionally, a deceleration injury can cause a disruption of the extensor mechanism. In this setting, it is also important to assess both the integrity of the meniscal cartilage with palpation of the joint line and the ACL with a Lachman test.¹⁷

If the diagnosis of tendon rupture is delayed, scar tissue may obliterate what previously had been a palpable defect. In this scenario, some degree of active extension may be possible, but with weakness and some degree of extensor lag. Quadriceps atrophy may also be noted, with considerable weakness, especially with weightbearing, stair climbing, and rising from a seated position. The weakness can exist to such a degree that the patient performs a forward thrusting motion of the limb in the swing phase of gait and complains of stance instability.

Related eMedicine topics:
Anterior Cruciate Ligament Injury
Knee, Meniscal Tears (MRI)

INDICATIONS

Section 3 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Early diagnosis and definitive treatment provide the best results. The type of treatment depends predominantly on the extent of the tear. The most common injury involves the acute, complete disruption of the tendon, and subsequent dysfunction of the extensor mechanism. In this setting, surgical repair is the treatment of choice. In general, repair should be performed as soon as possible after the injury to limit the degree of quadriceps atrophy and prevent any contractures that might make the procedure more difficult.

In some situations, a partial tear of the patellar tendon may occur. The patient may be able to maintain full, active extension and normal patellar height. This individual can potentially be treated nonoperatively with immobilization until the tendon has healed. However, one must be certain that the tear is, in fact, partial before initiating this program. An MRI may be useful in this situation (see Workup, Imaging Studies, below).

The chronicity of the tear is another factor that must be considered. After approximately 6 weeks, direct repair becomes challenging, if possible at all, with native tissue. Other techniques may be necessary to establish continuity of the extensor mechanism. Regardless of the timing, repair or reconstruction is still the optimal treatment in a patient who has sustained a patellar tendon tear with subsequent patella alta and extensor mechanism dysfunction.

RELEVANT ANATOMY

Section 4 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The patellar tendon is actually a ligament connecting 2 bones, the tibia and the patella. The extensor mechanism of the knee starts proximally as the quadriceps femoris muscle group. Anteriorly, the fibers of the rectus femoris tendon traverse the patella and condense inferior to the patella to insert on the tibial tubercle as the patellar tendon. The fibers of the vastus lateralis expand to the superolateral border of the patella and proximal tibia to form the lateral retinaculum. Similarly, the tendons of the vastus medialis insert into the superomedial border of the patella and tibia to form the medial retinaculum. The retinacula converge into the patellar tendon. Injuries to the tendon usually involve the adjacent retinacula as well, causing dysfunction of the entire extensor hood.

CONTRAINDICATIONS

Section 5 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

With disruption of the extensor mechanism of the knee, no absolute contraindications have been cited for the acute traumatic patellar tendon rupture. Perhaps in the case of an open, grossly contaminated wound, the need for a staged reconstruction following surgical debridements can be entertained. Nonetheless, the need for reestablishment of the extensor mechanism cannot be underestimated.

WORKUP

Section 6 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Lab Studies

• In the circumstance of patellar tendon rupture secondary to systemic disease, such as chronic renal failure, SLE, rheumatoid arthritis, or diabetes, the tendon rupture is rarely the harbinger or the first symptom of the disease. Therefore, although abnormal laboratory values may be found in the face of and consistent with the systemic disease, laboratory studies otherwise are indicated rarely in the workup for patellar tendon rupture.

Imaging Studies

• Plain radiographs
• • Plain radiographs (anteroposterior [AP], lateral, axial) should be obtained in all patients presenting with a traumatic injury to the knee or with a hemarthrosis.
  • Contralateral films should also be obtained as a means for comparison of patellar height.
  • Even if a palpable gap in the extensor mechanism allows for easy recognition of a patellar tendon rupture, radiographs are still necessary to assess for any other concomitant abnormalities.
  • The lateral view is particularly helpful to determine whether a patellar rupture has occurred. The classic finding is patella alta, but one may also notice calcification indicative of chronic patellar tendinosis (Image 2).
  • In addition, the axial view assists in determining whether any preexisting patellofemoral arthritis exists, which may impact the rehabilitative efforts and prognosis.
• Ultrasound
• • High-resolution ultrasound can be useful in the diagnosis of acute and chronic patellar tendon ruptures.
  • Hypoechogenicity is associated with acute tears, while thickening of the tendon at the rupture site and disruption of the normal echo pattern is observed with chronic tears.
  • While this modality is easy to obtain and does not expose the patient to radiation, many do not have the experience to reliably perform or interpret this type of study. Because of this, ultrasound is not used routinely in the United States, although it is used quite frequently in Europe.
• MRI
• • If the diagnosis cannot be established based on clinical and radiographic examination, an MRI is the imaging study of choice.
  • The typical finding is discontinuity of tendon fibers with adjacent hemorrhage or edema.¹⁸

Diagnostic Procedures

• No diagnostic procedure is routinely necessary to identify an acute patellar tendon rupture. If a question or concern exists of an intra-articular fracture or osteochondral injury, the joint can be aspirated to look for fat droplets. The routine use of aspiration and injection is not recommended.

Staging

Blazina, Kerlan, and Jobe described 3 clinical stages of patellar tendonitis (ie, jumper's knee) that culminate with patellar tendon rupture.¹⁹

Initially, the insidious onset of aching in the knee centers over the infrapatellar region and localizes to the inferior pole of the patella. This usually arises after the patient engages in repetitive activity such as jumping, climbing, kicking, or running. During the first stage of the disease, the pain is present only after athletic participation. The pain typically disappears after a period of rest. Sensations of weakness or 'giving way' are transient and never associated with locking or catching.

In the next stage, pain and symptoms occur at the beginning of an activity, disappear after a warm up, and then reappear after completion of the activity. The aching becomes more persistent, and, eventually, the discomfort persists throughout the entirety of the activity, but athletic performance is not significantly impaired.

In the next stage, the symptoms are the same but more prolonged, and performance is definitely impaired. The athlete might even become apprehensive about further participation.

Finally, if the athlete continues with intensive activity despite exacerbation of symptoms, he or she eventually may experience a sudden catastrophic 'giving way,' with pain and inability to actively extend the knee. This coincides with an acute and complete rupture of the patellar tendon.

TREATMENT

Section 7 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Medical therapy

Nonoperative treatment has a limited role in the care of patellar tendon ruptures. For the rare person with a partial patellar tendon tear with maintenance of patellar height, cast or brace immobilization in full extension for 6 weeks followed by a therapy program to regain motion and strength may be appropriate. Progress must be slow to allow for tendon-to-bone healing. Strengthening exercises should be delayed for at least 3 months.

Surgical therapy

Complete tears of the patellar tendon are best addressed with early surgical intervention. This allows the best opportunity for anatomic repair of all the injured structures within the extensor mechanism.

Several techniques have been described for the immediate repair of the acutely ruptured patellar tendon. In general, repair involves suturing the torn tendon through bone tunnels within the patella or tibial tubercle, depending on the location of the disruption. Additionally, retinacular tears are repaired anatomically.

In the unusual case of chronic patellar tendon tears, direct repair may be challenging or impossible. Surgical correction may be performed in stages, depending on the degree of patella alta and peripatellar scarring. Typically, the repair needs augmentation. Alternatively, the patellar tendon can be replaced with allograft or autograft tissue.^{20, 21, 22}

Preoperative details

As with any procedure, both the tissues and the patient must be ready for surgical intervention. The ultimate outcome depends not only on the anatomic repair of the extensor mechanism, but also on the rehabilitative efforts of the patient. It is important to stress in the preoperative period the importance of participating in the postoperative rehabilitative protocol so that maximal range of motion and strength can be achieved.

Patellar tendon ruptures with concomitant retinacular tears (Image 3) commonly result in diffuse swelling and ecchymosis along the anterior knee. Therefore, delaying surgical intervention until the inflammation begins to diminish may be safer. This 4-7 day delay may decrease the risk of wound complications.

Additional issues that should be considered are the extent of pathology within the ruptured tendon, the degree of patella alta, and the possibility of concomitant injuries within the knee. Extensive tendinosis or calcification within the ruptured tendon may compromise the repair. While no study has focused on this issue, the surgeon may choose to excise this pathologic tissue and may subsequently need to supplement the repair with additional tissue. Therefore, the patient and the surgeon must be ready to accept this alternative.

Since anatomic repair is the goal, the surgeon must identify the appropriate patellar height for the injured patient. A radiograph of the contralateral knee can serve as a template intraoperatively to assist in recreating the normal patellar position.

Concomitant injuries to the menisci, articular cartilage, or supporting ligamentous structures may be present. Depending on the location and extent of injury to these structures, additional intervention may be necessary. Therefore, the surgeon must consider this in the preoperative period so that surgical incisions are well planned and material needed for repair or reconstruction is available.²³

Intraoperative details

The patient is positioned supine on the operating table after a regional or general anesthetic is administered. A first-generation cephalosporin typically is administered, since nonabsorbable material is used. The procedure begins with an examination of both knees. Range-of-motion and ligamentous examination is performed to determine whether any motion deficits or concomitant ligamentous injuries are present.

A tourniquet is placed on the involved leg, and typically both legs are cleansed and draped free. After exsanguinating the limb and starting the tourniquet, a straight midline longitudinal incision is made, extending from the superior pole of the patella to the medial aspect of the tibial tubercle. Thick medial and lateral subcutaneous flaps are created to the extent of the retinacular tears.

The torn end of the patellar tendon is then mobilized and minimally debrided of friable tissue. Depending on the location of the tear, the tibial tubercle, inferior pole of the patella, or both are debrided of soft tissue and subsequently decorticated with a curette or bur (Image 5). Troughs are not created. Two No. 5 nonabsorbable sutures are then inserted using a Krackow stitch into each half of the tendon (Image 4). Three parallel tunnels are placed through the patella or tibial tubercle.

The authors advocate the technique recently described by Ong and Sherman of using an ACL tibial tunnel guide during this aspect of the procedure to maneuver the drill more accurately to the desired endpoint (Image 6).²⁴ Using the tunnel guide decreases the risk of violating the articular surface, reduces the number of passes required to obtain an optimal position, minimizes injury to the quadriceps tendon, and eliminates the additional step of retrieving sutures through drill holes.

The drill is then replaced with a Beath pin (Image 7). The inner limbs of each stitch are passed through the central tunnel, and then the outer limbs are passed through the outer tunnels (Image 8). In certain situations, the authors have used suture anchors in both the patella and the tibial tubercle with good results but still favor the use of tunnels at this time.

A drill hole is then created transversely through the tibial tubercle through which an additional No. 5 nonabsorbable suture is passed. This suture is then passed superiorly within the quadriceps tendon along the superior pole of the patella (Image 9). This is accomplished by passing a 16-gauge spinal needle along the superior pole and then threading the suture through.

Both knees are then positioned in 30° of flexion. The patellar height is measured from the tibial tubercle to the inferior pole of the patella on the noninvolved leg and recreated in the involved leg by increasing tension in the cerclage suture. Once the correct position is obtained, the repair sutures are tied and the knee is reexamined to assess the degree of knee flexion that can be obtained without causing excessive tension on the repair. Alternatively, an intraoperative radiograph can be obtained on the involved knee, prior to tying the repair sutures, and compared with the radiograph of the contralateral knee obtained in the preoperative period.

The repair site is then oversewn with No. 0 absorbable suture to bring the loose ends remaining on the avulsed side over the repair. The retinacular tears are closed with the same suture material but with the knee held in 30º of flexion to limit the possibility of capturing the knee and, thus, limiting motion (Image 10). The wound is then closed in standard fashion, with effort to minimize the amount of grasping of the skin edges. This hopefully further diminishes the risk of wound breakdown in this inflamed tissue. A standard dressing is applied, followed by a self-contained cooling device and hinged knee brace locked in extension.

Situations exist in which acute repair with only sutures is not adequate. This can occur when the patient has a midsubstance tear, has a chronic rupture, or has undergone a previous resection of chronic patellar tendinitis or a recent ACL reconstruction with the use of patellar tendon autograft. In these cases, augmentation or reconstruction may be necessary. Described techniques involve the use of both autograft (hamstrings, fascia lata, central quadriceps tendon) and allograft (Achilles tendon) tissue as well as synthetic material.^{20, 21, 22, 25, 26, 27, 28, 29, 30, 31} Regardless of the material used, these techniques generally involve weaving the supplemental tissue through the native patellar tendon or through bone tunnels within the patella, tibial tubercle, or both.

In the individual with a chronic tear, other factors are involved. Since the patella has been retracted for an extended period, significant scarring may develop, which limits the surgeon's ability to recreate normal patellar height and the ability to regain full knee motion. Adequate mobility can usually be obtained after thorough debridement of the medial and lateral gutters and subperiosteal elevation of the vastus intermedius from the anterior femur. If this is inadequate, a 2-staged reconstruction with preoperative traction with the use of a transverse Steinmann pin placed in the patella can be performed. When the remaining tendon is scarred and attenuated, a Z-lengthening of the quadriceps and Z-shortening of the patellar tendon can be performed. This allows for the sliding of the patella back to the anatomic position. A reconstructive technique as mentioned above then should follow.^{25, 26, 27, 32}

Allograft reconstructive techniques have also been described for care of the chronic patellar tendon rupture.^{28, 33} The procedure involves placement of the bone-block end of the graft into a trough created in the tibial tubercle. The tendinous end is then split and passed through one or more tunnels within the patella and/or encircling the patella medially and laterally.

Postoperative details

The ultimate goal of the surgical repair is the return of normal knee mechanics and strength. To achieve this goal, it is important for the repair to be stable enough to allow for early, controlled range of motion as described by Marder and Timmerman.³

Provided that a stable repair has been achieved, the authors' standard postoperative protocol is described below (see Table).

  Table Standard Postoperative Protocol

For tenuous repairs, whether for acute or chronic tears, a more conservative program is used and tailored to the situation. Generally, strict immobilization is recommended for 6 weeks, followed by range-of-motion exercises. Strengthening exercises are then started approximately 3 months after the repair, followed shortly thereafter by neuromuscular retraining. Return of quadriceps bulk and strength usually is delayed, and return to premorbid athletic activities may take approximately 9-12 months.

Follow-up

After an adequate repair allowing for an aggressive postoperative rehabilitative program, the follow-up care goals, with intervals dated as time after surgery, are as follows:

• 3-5 days - Adequate pain control, decrease in swelling and wound check
• 2 weeks - Active flexion to 45°, full passive extension
• 4 weeks - Active flexion to 90°, maintenance of full passive extension
• 6-8 weeks - Full active flexion
• 3 months - Straight leg raise with no extension lag
• 6 months - Symmetric quadriceps size and strength

COMPLICATIONS

Section 8 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Not infrequently, decreased quadriceps strength and loss of full knee flexion can complicate the overall success of a repair. Prolonged immobilization leads to stiffness. Manipulation under anesthesia or arthroscopic lysis of adhesions may be necessary to improve motion. Occasionally, the decreased range of motion can be attributed to patella baja. This is when the patella lies more distal than normal, which can result when the tendon is relatively shortened by the repair.

Rerupture, failure of fixation, or both also can occur, especially in patients who return to athletic endeavors before the tendon is completely healed. The repeat injury may require a revision of the repair. Inadequate placement of the suture repair or failure to recreate the appropriate patellar height can cause patellofemoral pain.

Wound breakdown and infections can occur, as with any other surgical intervention. These complications may be slightly more common in this region because of limited soft tissue along the anterior knee and operating through inflamed tissue. To diminish these potential wound complications, perioperative antibiotics and closed-suction drains can be used, the initial incision can be made through uncompromised skin, and grasping of the skin edges can be kept to a minimum.

OUTCOME AND PROGNOSIS

Section 9 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Immediate surgical repair of the ruptured patella tendon is recommended for optimal return of function. Outcome after repair is closely related to the length of time between injury and repair. If the tendon is repaired immediately, most patients experience nearly full return of knee motion, quadriceps strength, and preinjury activity levels.^{34, 35, 36, 37} Persistent quadriceps atrophy is common but is not considered a complication, as the atrophy does not prevent the return of strength.

Reasonable function can be obtained in most individuals, especially in the acute tendon rupture that is repaired immediately. Multiple authors have attributed an earlier return to preinjury activity to a more aggressive rehabilitation program with an emphasis on earlier range of motion.^{29, 38, 39, 40} Due to the relatively infrequent nature of this injury, the sample sizes in all the studies are rather small, and a meta-analysis has yet to be performed to further delineate the statistical significance of an aggressive rehabilitative protocol. Nonetheless, there appears to be a definite trend toward aggressive postoperative rehabilitation for earlier return to preinjury activity, much like that observed with the repaired Achilles tendon.

FUTURE AND CONTROVERSIES

Section 10 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Definite progress has been made in the surgical technique and clinical care for acute patellar tendon ruptures, including the use of the ACL tibial guide, augmentation with Dall-Miles cables³⁸ or nonabsorbable suture, and aggressive rehabilitation for improved range of motion and strength. In the future, suture anchors may alleviate the need for creating tunnels through the patella and could decrease surgical morbidity by allowing for a smaller incision and more consistent anatomic placement of the torn site onto the patella.⁴¹

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Media file 1:  Patellar tendon rupture. This image depicts the defect within the patellar tendon at the inferior pole of the patella.
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Media file 2:  Patellar tendon rupture. A lateral radiograph of the right knee from a patient with an acute patellar tendon rupture. Note the superior patellar migration as well as the calcification below the inferior pole of the patella. This represents preexisting calcification within the patellar tendon, which likely contributed to the rupture.
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Media file 3:  Patellar tendon rupture. This intraoperative picture depicts a rupture of the patellar tendon from the inferior pole of the patella with associated medial and lateral retinacular tears.
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Media file 4:  Patellar tendon rupture. Two Krackow stitches with number 5 nonabsorbable sutures are sewn through the patellar tendon.
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Media file 5:  Patellar tendon rupture. The inferior pole of the patella is debrided of soft tissue, then decorticated.
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Media file 6:  Patellar tendon rupture. An anterior cruciate ligament tibial tunnel guide is positioned along the anterior half of inferior pole and angled such that the drill exits along the superior pole of the patella. A total of 3 parallel tunnels are created. Note the contralateral knee within the operative field, which later serves as the guide in recreating normal patellar height.
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Media type:  Photo

Media file 7:  Patellar tendon rupture. The Beath pin replaces the drill bit. The suture is then placed through the eyelet.
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Media file 8:  Patellar tendon rupture. All of the suture ends are now along the superior pole of the patella. The inner limbs of the stitches are within the central tunnel while the outer limbs are within the corresponding outer tunnels.
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Media file 9:  Patellar tendon rupture. A cerclage stitch was passed along the superior pole of the patella and through a tunnel within the tibial tubercle. This is now being tensioned to maintain normal patellar height so that the repair sutures can now be tied.
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Media file 10:  Patellar tendon rupture. The repair is now complete with recreation of normal patellar height. The retinacular tears were repaired with absorbable suture with the knee positioned in 30° of flexion.
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REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

1. Bonamo JJ, Krinick RM, Sporn AA. Rupture of the patellar ligament after use of its central third for anterior cruciate reconstruction. A report of two cases. J Bone Joint Surg Am. Oct 1984;66(8):1294-7. [Medline].
2. Krackow KA, Thomas SC, Jones LC. A new stitch for ligament-tendon fixation. Brief note. J Bone Joint Surg Am. Jun 1986;68(5):764-6. [Medline].
3. Marder RA, Timmerman LA. Primary repair of patellar tendon rupture without augmentation. Am J Sports Med. May-Jun 1999;27(3):304-7. [Medline].
4. Ramseier LE, Werner CML, Heinzelmann M. Quadriceps and patellar tendon rupture. Injury. 2006;37:516-519.
5. Scuderi GS, Easley ME. Quadriceps and patellar tendon disruptions. In: Scott WN, ed. Surgery of the Knee. 3rd ed. WB Saunders Co;2001:1074-1086.
6. Kannus P, Jozsa L. Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients. J Bone Joint Surg Am. Dec 1991;73(10):1507-25. [Medline].
7. Ismail AM, Balakrishnan R, Rajakumar MK, Lumpur K. Rupture of patellar ligament after steroid infiltration. Report of a case. J Bone Joint Surg Br. Aug 1969;51(3):503-5. [Medline].
8. Kennedy JC, Willis RB. The effects of local steroid injections on tendons: a biomechanical and microscopic correlative study. Am J Sports Med. Jan-Feb 1976;4(1):11-21. [Medline].
9. Kelly DW, Carter VS, Jobe FW, Kerlan RK. Patellar and quadriceps tendon ruptures--jumper's knee. Am J Sports Med. Sep-Oct 1984;12(5):375-80. [Medline].
10. Giblin P, Small A, Nichol R. Bilateral rupture of the ligamentum patellae: two case reports and a review of the literature. Aust N Z J Surg. Apr 1982;52(2):145-8. [Medline].
11. Rose PS, Frassica FJ. Atraumatic bilateral patellar tendon rupture, A case report and review of the literature. J Bone Joint Surg Am. Sep 2001;83-A(9):1382-6. [Medline].
12. Ozkan C, Kalaci A, Tan I, Sarpel Y. Bilateral dislocation of the knee with rupture of both patellar tendons. A case report. The Knee. 2006;13:333-336.
13. Pritchard CH, Berney S. Patellar tendon rupture in systemic lupus erythematosus. J Rheumatol. Jun 1989;16(6):786-8. [Medline].
14. Furie RA, Chartash EK. Tendon rupture in systemic lupus erythematosus. Semin Arthritis Rheum. Nov 1988;18(2):127-33. [Medline].
15. Kurer MH, Baillod RA, Madgwick JC. Musculoskeletal manifestations of amyloidosis. A review of 83 patients on haemodialysis for at least 10 years. J Bone Joint Surg Br. Mar 1991;73(2):271-6. [Medline].
16. Finlayson GR, Smith JG Jr, Moore MJ. Effects of chronic acidosis on connective tissue. JAMA. 1964;187:659-662.
17. Costa-Paz M, Muscolo DL, Makino A, Ayerza MA. Simultaneous Acute Rupture of the Patellar Tendon and the Anterior Cruciate Ligament. Arthroscopy. Sept. 2005;21:1143e1-1143e4.
18. Yu JS, Petersilge C, Sartoris DJ, et al. MR imaging of injuries of the extensor mechanism of the knee. Radiographics. May 1994;14(3):541-51. [Medline].
19. Blazina ME, Kerlan RK, Jobe FW, et al. Jumper's knee. Orthop Clin North Am. Jul 1973;4(3):665-78. [Medline].
20. Burks RT, Edelson RH. Allograft reconstruction of the patellar ligament. A case report. J Bone Joint Surg Am. Jul 1994;76(7):1077-9. [Medline].
21. Emerson RH Jr, Head WC, Malinin TI. Reconstruction of patellar tendon rupture after total knee arthroplasty with an extensor mechanism allograft. Clin Orthop. Nov 1990;(260):154-61. [Medline].
22. Williams RJ 3rd, Brooks DD, Wickiewicz TL. Reconstruction of the patellar tendon using a patella-quadriceps tendon autograft. Orthopedics. Jun 1997;20(6):554-8. [Medline].
23. Futch LA, Garth WP, Folsom GJ, Ogard WK. Acute Rupture of the Anterior Cruciate Ligament and Patellar Tendon in a Collegiate Athlete. Arthroscopy. Jan. 2007;23:112e1-112e4.
24. Ong BC, Sherman O. Acute patellar tendon rupture: A new surgical technique. Arthroscopy. Nov 2000;16(8):869-70. [Medline].
25. Ecker ML, Lotke PA, Glazer RM. Late reconstruction of the patellar tendon. J Bone Joint Surg Am. Sep 1979;61(6A):884-6. [Medline].
26. Evans PD, Pritchard GA, Jenkins DH. Carbon fibre used in the late reconstruction of rupture of the extensor mechanism of the knee. Injury. Jan 1987;18(1):57-60. [Medline].
27. Mandelbaum BR, Bartolozzi A, Carney B. A systematic approach to reconstruction of neglected tears of the patellar tendon. A case report. Clin Orthop. Oct 1988;(235):268-71. [Medline].
28. McNally PD, Marcelli EA. Achilles allograft reconstruction of a chronic patellar tendon rupture. Arthroscopy. Apr 1998;14(3):340-4. [Medline].
29. Larson RV, Simonian PT. Semitendinosus augmentation of acute patellar tendon repair with immediate mobilization. Am J Sports Med. Jan-Feb 1995;23(1):82-6. [Medline].
30. Miskew DB, Pearson RL, Pankovich AM. Mersilene strip suture in repair of disruptions of the quadriceps and patellar tendons. J Trauma. Oct 1980;20(10):867-72. [Medline].
31. Levy M, Goldstein J, Rosner M. A method of repair for quadriceps tendon or patellar ligament (tendon) ruptures without cast immobilization. Preliminary report. Clin Orthop. May 1987;(218):297-301. [Medline].
32. Takebe K, Hirohata K. Old rupture of the patellar tendon. A case report. Clin Orthop. Jun 1985;(196):253-5. [Medline].
33. Wascher DC, Summa CD. Reconstruction of chronic rupture of the extensor mechanism after patellectomy. Clin Orthop. Dec 1998;(357):135-40. [Medline].
34. Hsu KY, Wang KC, Ho WP, Hsu RW. Traumatic patellar tendon ruptures: a follow-up study of primary repair and a neutralization wire. J Trauma. May 1994;36(5):658-60. [Medline].
35. Kuechle DK, Stuart MJ. Isolated rupture of the patellar tendon in athletes. Am J Sports Med. Sep-Oct 1994;22(5):692-5. [Medline].
36. Larsen E, Lund PM. Ruptures of the extensor mechanism of the knee joint. Clinical results and patellofemoral articulation. Clin Orthop. Dec 1986;(213):150-3. [Medline].
37. Siwek CW, Rao JP. Ruptures of the extensor mechanism of the knee joint. J Bone Joint Surg Am. Jul 1981;63(6):932-7. [Medline].
38. Shelbourne KD, Darmelio MP, Klootwyk TE. Patellar tendon rupture repair using Dall-Miles cable. Am J Knee Surg. Winter 2001;14(1):17-20; discussion 20-1. [Medline].
39. Matava MJ. Patellar Tendon Ruptures. J Am Acad Orthop Surg. Nov 1996;4(6):287-296. [Medline].
40. West JL, Keene JS, Kaplan LD. Early Motion After Quadriceps and Patellar Tendon Repairs. American Journal of Sports Medicine. Feb. 2008;36:316-323.
41. Bushnell BD, Weinhold PS, Creighton RA. The Use of Suture Anchors in Repair of the Ruptured Patellar Tendon. American Journal of Sports Medicine. Sept. 2006;34:1492-1499.
42. Ravalin RV, Mazzocca AD, Grady-Benson JC, Nissen CW, Adams DJ. Biomechanical comparison of patellar tendon repairs in a cadaveric model. American Journal of Sports Medicine. 2002;30:469-473.

Article Last Updated: Jun 12, 2008