Introduction

Quadriceps and patellar tendon ruptures are relatively uncommon injuries, but proper management is essential given the importance of maintaining knee extensor mechanism function. Quadriceps tendon ruptures are more common than patellar tendon ruptures and occur at an older age, typically greater than 40. The risk factors for rupture are similar between both entities and consist of chronic steroid use, diabetes, renal disease, lupus, gout, hyperparathyroidism, and rheumatoid arthritis. Generally, the mechanism of injury is described as eccentric loading of the tendon against a flexed knee. With increasing flexion angle at the time of injury, more stress is put on the patellar tendon and likely to lead to patellar tendon rupture instead of quadriceps tendon rupture. Early diagnosis and surgical management is of paramount importance to achieve excellent results in complete ruptures (▶Video 39.1).

I. Preoperative

1. 
   

   History

   
   
   
   
   1. 
      

      Past medical history (lupus, rheumatoid, diabetes, gout, hyperparathyroidism).

      
      
   2. 
      

      Medications (chronic steroid use, local steroid injection).

      
      
   3. 
      

      Mechanism of injury (i.e., flexed knee, jumping).

      
      
   4. 
      

      Activities (sports, history of overuse, previous tendinitis).

      
      
   5. 
      

      High index of suspicion (reports of 10–50% missed diagnosis rates).

   
   
2. 
   

   Physical examination

   
   
   
   
   1. 
      

      Quadriceps tendon rupture:

      
      
      
      
      1. 
         

         Palpable defect near proximal pole of patella.

         
         
      2. 
         

         Knee effusion/hemarthrosis.

         
         
      3. 
         

         Tenderness to palpation over quadriceps tendon.

         
         
      4. 
         

         Weakness/pain with resisted knee extension.

         
         
      5. 
         

         Inability to perform straight leg raise with complete rupture.

         
         
      6. 
         

         Patella baja or normal patellar height.

      
      
   2. 
      

      Patellar tendon rupture:

      
      
      
      
      1. 
         

         Palpable defect near inferior pole of patella.

         
         
      2. 
         

         Patella alta.

         
         
      3. 
         

         Pain over patellar tendon.

         
         
      4. 
         

         Knee effusion/hemarthrosis.

         
         
      5. 
         

         Weak knee extension (partial tear).

         
         
      6. 
         

         Inability to perform straight leg raise with complete tear.

   
   
3. 
   

   Anatomy

   
   
   
   
   1. 
      

      Quadriceps tendon:

      
      
      
      
      1. 
         

         Coalescence of rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis.

         
         
      2. 
         

         Forms a tendon 3 cm proximal to the superior pole of the patella.

         
         
      3. 
         

         Distinct layers:

         
         
         
         
         • 
           

           i. Superficial—rectus femoris fibers.

           
           
         • 
           

           ii. Middle—vastus lateralis and vastus medialis fibers.

           
           
         • 
           

           iii. Deep—vastus intermedius fibers in continuity with synovium.

      
      
   2. 
      

      Patellar tendon:

      
      
      
      
      1. 
         

         Continuation of the quadriceps tendon as it envelopes the patella (the largest sesamoid bone) and attaches to the tibial tubercle.

         
         
      2. 
         

         Average thickness of the tendon is 4 mm and increases to 5 to 6 mm at the tibial tubercle.

         
         
      3. 
         

         Tightly invested with the medial and lateral retinacula, so frequently these are torn as well.

   
   
4. 
   

   Imaging

   
   
   
   
   1. 
      

      Quadriceps and patella tendon rupture.

      
      
      
      
      1. 
         

         Anteroposterior and lateral X-ray of the knee.

         
         
         
         
         • 
           

           i. Can show obliteration of quadriceps/patellar tendon shadow.

           
           
         • 
           

           ii. Patella baja or normal in quadriceps tendon ruptures (▶ Fig. 39.1 ).

           

           
           
         • 
           

           iii. Patella alta in patellar tendon ruptures (▶ Fig. 39.2 ).

           

      
      
   2. 
      

      Arthrography:

      
      
      
      
      1. 
         

         Mostly historical with the increased access to MRI.

         
         
      2. 
         

         Injection of contrast material can show extravasation.

      
      
   3. 
      

      Ultrasound:

      
      
      
      
      1. 
         

         Very sensitive and noninvasive.

         
         
      2. 
         

         Can distinguish complete from partial tears.

         
         
      3. 
         

         Downside is that reliability is operator dependent and does not evaluate associated injuries.

      
      
   4. 
      

      MRI:

      
      
      
      
      1. 
         

         High sensitivity, used if suspicion for partial tearing.

         
         
      2. 
         

         Useful to determine tear location for surgical planning or diagnosis of concomitant injuries.

         
         
      3. 
         

         High cost, not necessary for most cases.

II. Treatment

1. 
   

   Initial and definitive management

   
   
   
   
   1. 
      

      Quadriceps tendon tear:

      
      
      
      
      1. 
         

         Partial tendon tear with no functional deficit:

         
         
         
         
         • 
           

           i. Can be treated closed, or nonoperatively.

           
           
         • 
           

           ii. Immobilize in full extension with brace for 6 weeks, followed by physical therapy.

           
           
         • 
           

           iii. Aggressively treat effusion due to quadriceps deactivation by using ice, compression, anti-inflammatories, ± aspiration.

           
           
         • 
           

           iv. Discontinue brace once quadriceps strength has been regained.

         
         
      2. 
         

         Complete tear or partial with functional deficit:

         
         
         
         
         • 
           

           i. Immediately immobilize in extension.

           
           
         • 
           

           ii. Ice, compression, and aspiration may help pain and quadriceps deactivation; however, there is no proven benefit from aspiration.

           
           
         • 
           

           iii. Poor results with nonsurgical management.

           
           
         • 
           

           iv. Outcomes are better with surgical fixation within 2 to 3 weeks.

           
           
         • 
           

           v. Delayed surgical repair results in increased complications and less satisfactory results.

           
           
         • 
           

           vi. Many surgical methods have been described with no clear benefit of one or the other and is dependent on location of tear.

      
      
   2. 
      

      Patellar tendon rupture:

      
      
      
      
      1. 
         

         Partial tendon tear with intact extensor mechanism:

         
         
         
         
         • 
           

           i. Can be treated closed, or nonoperatively.

           
           
         • 
           

           ii. Immobilize in full extension 2 to 4 weeks followed by range-of-motion (ROM) exercises at 4 to 6 weeks.

           
           
         • 
           

           iii. Rest, ice, elevation, compression, and aspiration can improve early pain and ROM; however, these controversies remained unresolved.

         
         
      2. 
         

         Complete tear or partial tear with functional deficits:

         
         
         
         
         • 
           

           i. Immobilize in full extension immediately.

           
           
         • 
           

           ii. Aspiration, ice, and compression remain controversial with regard to benefit.

           
           
         • 
           

           iii. Early surgical planning is important as these cannot be managed nonoperatively.

           
           
         • 
           

           iv. These injuries require timely surgical repair to avoid retraction or complications associated with delayed treatment.

           
           
         • 
           

           v. Several techniques have been described based on location of tear, including use of patellar drill holes and suture anchors.

   
   
2. 
   

   Surgical approaches

   
   
   
   
   1. 
      

      Quadriceps tendon rupture—midline incision centered over the quadriceps tendon.

      
      
      
      
      1. 
         

         Create full thickness flaps to expose entire tendon.

         
         
      2. 
         

         Evacuate hematoma and debride free edges of the tendon.

      
      
   2. 
      

      Patellar tendon rupture—midline incision based from mid-patella to the tibial tubercle.

      
      
      
      
      1. 
         

         Create full-thickness flaps to expose tendon and likely ruptured retinaculum (▶Fig. 39.3 ).

         

         
         
      2. 
         

         Evacuate hematoma and clean free edges of tendon (▶ Fig. 39.4 ).

         

         
         
      3. 
         

         If avulsion of distal pole of patella, clean free bone edge.

   
   
3. 
   

   Fixation techniques

   
   
   
   
   1. 
      

      Quadriceps tendon rupture:

      
      
      
      
      1. 
         

         Midsubstance tearing—primary end-to-end repair with nonabsorbable sutures.

         
         
      2. 
         

         Osteotendinous junction tearing of the quadriceps tendon.

         
         
         
         
         • 
           

           i. Two nonabsorbable sutures passed in a Krackow fashion leaving four free strands in the distal stump (▶ Fig. 39.5a ).

           

           
           
         • 
           

           ii. Roughen the superior pole of the patella to promote bone–tendon healing.

           
           
         • 
           

           iii. Drill three parallel 2-mm paths in the longitudinal axis of the patella and pass the lateral and medial strands through the lateral and medial drill holes.

           
           
         • 
           

           iv. The two central strands are passed through the middle drill hole and each side is tied on the inferior pole.

           
           
         • 
           

           v. Close the retinaculum and take the knee through ROM to ensure appropriate patellar tracking.

           
           
         • 
           

           vi. Newer techniques involve the use of suture anchors due to simplicity and shorter operative time.

           
           
         • 
           

           vii. Scuderi quadriceps turndown of fascia lata graft used for augmentation if repair is tenuous.

      
      
   2. 
      

      Patellar tendon rupture:

      
      
      
      
      1. 
         

         Midsubstance tearing.

         
         
         
         
         • 
           

           i. Two nonabsorbable sutures passed in a Bunnell or a Krackow fashion.

           
           
         • 
           

           ii. Tension can be approximated intraoperatively with use of a lateral knee X-ray and comparison of patellar height to the contralateral side.

           
           
         • 
           

           iii. Once the correct tension is obtained, the tear can be oversewn with nonabsorbable suture in a simple fashion.

         
         
      2. 
         

         Osteotendinous junction tear at the patella:

         
         
         
         
         • 
           

           i. Two nonabsorbable sutures passed in a Krackow fashion.

           
           
         • 
           

           ii. These are passed through three vertical bone tunnels in the patella in similar fashion as described above (▶ Fig. 39.5b ).

           
           
         • 
           

           iii. Sutures are tied on the superior pole of the patella (▶ Fig. 39.6 ).

           

           
           
         • 
           

           iv. Tension can be compared by taking a lateral knee X-ray and matching patellar height to contralateral limb X-ray.

           
           
         • 
           

           v. Once correct tension is obtained, the tear can be oversewn with nonabsorbable suture in a simple fashion (▶ Fig. 39.7 ).

           

           
           
         • 
           

           vi. Augmentation with Mersilene Tape (Ethicon, United States) or number 5 Mersilene suture using medial to lateral drill holes near the tubercle and through the patella or quadriceps tendon insertion to relieve tension off the repair is becoming more historical.

           
           
         • 
           

           vii. Use of suture anchors has been shown to be stronger in cadaveric studies, but reports of higher rerupture rates clinically have called this into question.

   
   
4. 
   

   Complications

   
   
   
   
   1. 
      

      Quadriceps tendon repair:

      
      
      
      
      1. 
         

         Loss of ROM is the most common complication.

         
         
      2. 
         

         Patella fracture from osseous tunnels.

         
         
      3. 
         

         Rerupture of quadriceps tendon.

      
      
   2. 
      

      Patellar tendon repair:

      
      
      
      
      1. 
         

         Recurrent hemarthrosis requiring drainage.

         
         
      2. 
         

         Wound complications and infections.

         
         
      3. 
         

         Tendon rerupture.

         
         
      4. 
         

         Patella baja with decreased ROM from overtensioning.

         
         
      5. 
         

         Patella fracture from osseous tunnels.

   
   
5. 
   

   Rehabilitation

   
   
   
   
   1. 
      

      Quadriceps tendon repair:

      
      
      
      
      1. 
         

         Postoperatively, the knee is placed into a locked knee brace and allowed to weight-bear in full extension.

         
         
      2. 
         

         ROM typically begins around 4 to 6 weeks post-op.

         
         
      3. 
         

         Therapy focuses on ROM and quadriceps strengthening.

         
         
      4. 
         

         Brace is typically removed around 12 weeks when good quadriceps function is regained and the patient is able to perform a straight leg raise.

      
      
   2. 
      

      Patellar tendon repair:

      
      
      
      
      1. 
         

         Touchdown weight bearing in extension with crutches postoperatively—Many surgeons may allow immediate weight bearing with the knee locked in extension.

         
         
      2. 
         

         Isometric hamstring exercises begin day 1.

         
         
      3. 
         

         Active flexion and passive extension 0 to 45 degrees begin at week 2.

         
         
      4. 
         

         Active knee extension begins at 3 weeks.

         
         
      5. 
         

         Full weight bearing in extension begins at week 6 if it was previously restricted.

         
         
      6. 
         

         Recent studies reported higher complications and failure rates of both quadriceps and patellar tendon repairs with prolonged immobilization.

   
   
6. 
   

   Outcomes

   
   
   
   
   1. 
      

      Quadriceps tendon repair outcomes:

      
      
      
      
      1. 
         

         Early surgical repair results in more satisfactory outcomes in ROM and strength. Multicenter studies have reported successful outcomes between 83 and 100% with good to excellent results and return to activity.

         
         
      2. 
         

         Delay of surgical repair of 2 weeks post injury yielded good results, but 4-, 12-, and 14-week delays had unsatisfactory results.

         
         
      3. 
         

         Up to 85% of patients are able to return to previous occupation, but may lose up to 12% of quadriceps strength, and up to 10 degrees of motion.

      
      
   2. 
      

      Patellar tendon repair outcomes:

      
      
      
      
      1. 
         

         Repair within 7 days has shown 80% excellent and 16% good results.

         
         
      2. 
         

         Delayed repair is associated with longer quadriceps atrophy.