Updated: 10/4/2016

MPFL Reconstruction - Pediatric and Adolescent

Review Topic

Preoperative Patient Care


Intermediate Evaluation and Management


Obtains focused history and physical

  • history
  • symptoms
  • physical exam
  • recognizes factors that could predict complications or poor outcome


Orders and interprets required diagnostic studies

  • radiographs


Makes informed decision to proceed with operative treatment

  • documents failure of nonoperative management
  • describes accepted indications and contraindications for surgical intervention


Postop: 3-4 Week Postoperative Visit

  • wound check
  • start full range of motion at 4 with progressive quadriceps strengthening, edema control, pain control and gait training
  • continue to use the brace in community setting until adequate quadriceps strength has returned at about 6 weeks
  • diagnose and management of early complications

Advanced Evaluation and Management


Post operative instructions

  • Hinged knee brace locked in extension during ambulation for 4 weeks postoperatively, followed by slow weaning
  • May unlock brace during sitting
  • Gradual increase from touch down weight bearing to full weight bearing over 4 weeks postoperatively


Physical Therapy guidelines

  • Begin PT within one week following surgery
  • Limit knee flexion to 90 degrees for first 6 weeks post operatively
  • Closed chain strengthening per weight bearing restrictions, core, hip abductor strengthening
  • If meeting PT criteria, jogging by 3-4 months postoperatively can be allowed
  • Return to sports activity by 5-6 month postoperatively if meeting PT criteria

Operative Techniques


Preoperative Plan


Preoperative clinical assessment

  • Evaluate gait, lower extremity angular and rotational profile, Q angle, tibial torsion, patella tilt, femoral version, ligamentous laxity (Beighton score), and range of motion
  • Clinical questioning to assess Tanner stage


Preoperative radiographic assessment

  • Radiographs - AP, lateral, and sunrise of the injured knee
  • Assess physeal development, osteochondral injury, trochlear dysplasia, patella alta
  • MRI as indicated
  • More fully characterize osteochondral injuries, trochlear dysplasia, bone edema, location of MPFL injury, associated intraarticular pathologies, and tibial tubercle to trochlear groove distance
  • Angular profile as indicated
  • Full length standing hips to ankles AP radiograph if concern for angular (varus/valgus) malalignment on clinical exam
  • Bone age Xray as indicated
  • PA hand and wrist radiograph if skeletal age unclear on lower extremity radiographs


Examine the knee under anesthesia

  • Range of motion, Ligamentous stability, medial and lateral patellar translation in 25-30 degrees of knee flexion. Compare all exam findings to contralateral side

Room Preparation


Surgical instrumentation

  • Basic arthroscopy set
  • Basic orthopaedic set
  • K-wires
  • Bioabsorbable suture anchor with braided non-absorbable sutures


Room setup and equipment

  • Radiolucent OR table
  • Arthroscopy equipment - smaller patients will benefit from a small arthroscope to minimize iatrogenic cartilage damage
  • C-arm positioned on the opposite side of the injured extremity


Patient positioning

  • Supine
  • Lateral post for valgus stress for arthroscopic procedure
  • Radiolucent triangle under knee

Graft Exposure


Expose the graft

  • Graft exposure and preparation is performed after knee arthroscopy
  • A lateral release in carefully selected patients can be performed if tightness of the lateral retinaculum prevents normal medial patella translation or in cases of abnormal patella tilting
  • Longitudinal incision from superior pole of the medial aspect of patella, extending 5 to 6-cm proximally
  • Full-thickness flaps developed and dissected down to the quadriceps tendon and its insertion on patella


Femoral sided exposure

  • 2-cm longitudinal incision centered over medial epicondyle based on fluoroscopy and palpation
  • Dissection performed distal to physis to level of bone

Graft Preparation


Harvest graft

  • Identify VMO insertion on quadriceps tendon, harvest just lateral to VMO leaving 1-2-mm sleeve of remaining quadriceps tendon medially
  • Harvest an 8-mm by 70-mm full-thickness graft leaving the patella insertion intact
  • If tendon very thick can harvest partial-thickness graft


Place suture in graft

  • Suture the proximal free end of the graft with a whip stitch using a non-absorbable suture to prepare for passage of the graft

Graft Passage


Graft passage

  • Create tunnel for passing graft with large hemostat between the medial retinaculum and the synovium

Graft Tensioning


Identification of femoral insertion of MPFL

  • Use radiolucent triangle to flex knee to around 40 degrees to facilitate lateral radiograph
  • Find the "Schottle point": Identify MPFL insertion on lateral fluoroscopic radiograph 2-mm anterior to posterior cortex of the femur, and 2-mm distal to the posterior origin of the medial femoral condyle, and just proximal to Blumensaat line
  • Anatomic site for the femoral attachment of the MPFL lies a few millimeters distal to the medial aspect of the distal femoral physis
  • Place bioabsorbable suture anchor at this femoral insertion point


Tension the graft

  • Place knee in 30 to 45 degrees of flexion
  • Patella should translate about 10-mm laterally before end point to prevent overtensioning
  • Goal is to maintain the patella tracking centrally in the trochlea without any sign of medial subluxation
  • Provisional placement of pilot stitch
  • Place pilot suture through graft and periosteum of epiphyseal region of distal femur after setting tension of graft
  • Gently range knee through flexion and extension to assess graft tension and patellar position with motion
  • Make adjustments to this pilot stitch as indicated based on improper tensioning
  • Use sutures from previously placed suture anchor to secure graft on the femoral side in the position determined by pilot suture
  • Reinforcement of fixation on femoral side with additional non-absorbable sutures to medial intermuscular septum
  • Place non-absorbable sutures from periosteum of patella into graft
  • Assess patellar tracking through range of knee motion

Wound Closure


Deep closure

  • Quadriceps tendon graft site closed with absorbable vicryl suture


Superficial wound closure

  • Subcutaneous tissues closed with absorbable interrupted suture
  • Skin closed with running subcuticular suture


Dressings and immobilization

  • Place in a locked hinged knee brace in full extension

Postoperative Patient Care


Perioperative Inpatient Management


Write comprehensive admission orders

  • advance diet as tolerated
  • IV fluids
  • pain control
  • physical therapy
  • start active and passive range of motion in a few days to prevent any arthrofibrosis
  • use protected weightbearing with crutches until the patient is comfortable enough to walk in a locked knee brace in full extension
  • restrict range of motion to 0 to 90 degrees for the first 3 to 4 weeks


Discharges patient appropriately

  • pain control
  • schedule follow up in 3-4 weeks
  • wound care

Complex Patient Care


Able to develop a comprehensive preoperative plan that includes options based on intraoperative findings


Please rate topic.

Average 4.0 of 2 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Case ID Date Hospital Faculty CPT Codes
Topic COMMENTS (0)
Private Note