ACL Tear

Topic updated on 11/28/16 8:36am
  • Incidence
    • ~400,000 ACL reconstructions / year
  • Mechanism is a non-contact pivoting injury
    • video showing ACL tear in elite athlete
  • Often associated with a meniscal tear
    • lateral meniscal tears in 54% of acute ACL tears  
  • Chronic ACL deficient knees associated with
    • chondral injuries
    • complex unrepairable meniscal tears
    • relation with arthritis is controversial
  • Sex-related differences
    • ACL injury more common in female athlete (4.5 :1 ratio) due to 
    • landing biomechanics (conditioning and strength) play biggest role
    • females get ACL injuries at younger age than males
    • females get more ACL injuries on the supporting leg (males get more ACL injuries on the kicking leg)
Sex Differences   
  • BMI
  • Impingement on intercondylar notch, smaller notch
  • Smaller ACL
  • Hypermobility/joint laxity
  • Previous ACL injury
  • Increased knee valgus and extension during landing
  • Decreased knee and hip flexion
  • Fatigue resistance
  • Lower hamstring:quad ratio (more quads dominant)
  • Lower hamstring recruitment
  • Weaker core stability
  • Preovulatory phase of menses (hormones affect coordination)
  • Females on OCP not as affected during this phase
  • collagen production (COL5A1 gene linked to decreased risk of injury in women)
  • ACL Function   
    • provides 85% of the stability to prevent anterior translation of the tibia relative to the femur
    • acts as secondary restraint to tibial rotation and varus/valgus rotation
  • ACL Anatomy
    • 32mm length x 7-12mm width in size
    • goes from LFC to anterior tibia (tibial insertion is broad and irregular and inserts just anterior and between the intercondylar eminences of the tibia)
    • two bundles
      • anteromedial bundle
        • more isometric
        • tight in flexion
      • posterolateral bundle
        • tightest in extension (where it likely contributes greatest to rotational stability)
  • ACL Blood supply
    • middle geniculate artery
  • ACL Innervation
    • posterior articular nerve (branch of tibial nerve)
  • ACL Composition
    • 90% Type I collagen 
    • 10% Type III collagen
  • ACL Strength: 2200 N (anterior)
  • Presentation
    • felt a "pop"
    • pain deep in knee
    • immediate swelling (70%) / hemarthrosis
  • Physical exam
    • effusion
    • quadricep avoidance gait (does not actively extend knee)
    • Lachman's test  
      • most sensitive exam test
      • grading
        • A= firm endpoint, B= no endpoint
        • Grade 1: 3-5 mm translation
        • Grade 2 A/B: 5-10mm translation
        • Grade 3 A/B: > 10mm translation
      • PCL tear may give "false" Lachman due to posterior subluxation
    • Pivot shift   
      • extension to flexion: reduces at 20-30° of flexion
      • patient must be completely relaxed (easier to elicit under anesthesia)
      • mimics the actual giving way event
    • KT-1000 
      • useful to quantify anterior laxity
      • measured with knee in slight flexion and externally rotated 10-30° 
  • Radiographs
    • usually normal
    • Segond fracture (avulsion fracture of the proximal lateral tibia) is pathognomonic for an ACL tear
  • MRI
    • ACL tear best seen on sagittal view
    • bone bruising occurs in more than half of acute ACL tears  
      • middle 1/3 of LFC (sulcus terminalis)
      • posterior 1/3 of lateral tibial plateau
    • subchondral changes on MRI can persist years after injury
  • Nonoperative
    • physical therapy & lifestyle modifications
      • low demand patients with decreased laxity
      • increased meniscal/cartilage damage linked to
        • loss of meniscal integrity
        • frequency of buckling episodes
        • level I and II activity (e.g. jumping, cutting, side-to-side sports, heavy manual labor)
  • Operative
    • ACL reconstruction
      • indications
        • younger, more active patients (reduces incidence of meniscal or chondral injury)
        • children (strongly consider operative as activity limitation is not realistic)
        • older active patients (age >40 is not contraindication if high demand athlete)
        • prior ACL reconstruction failure
      • associated injuries
        • MCL injury
          • allow MCL to heal (varus/valgus stability) and then perform ACL reconstruction
          • varus/valgus instability can jeopardize graft
        • meniscal tear
          • perform meniscal repair at same time as ACL reconstruction
          • increased healing rate when repaired at the same time as ACL
        • posterolateral corner injury
          • reconstruct at the same time as ACL or as first-stage of two stage reconstruction
      • outcomes
        • return to play
          • largely influenced by psycholgical, demographic and functional outcomes  
    • ligament "repair" 
      • has high failure rate
    • revision ACL reconstruction
      • indications
        • failure of prior ACL reconstruction
Surgical Techniques
  • Femoral tunnel placement  
    • proper placement    
      • sagittal plane
        • 1-2 mm rim of bone between tunnel and posterior cortex of femur
      • coronal plane
        • tunnel should be placed on lateral wall (9-10 o'clock position) to create more horizontal graft
  • Tibial tunnel placement
    • proper placement
      • sagittal plane
        • center of tunnel entrance into joint should be 10-11mm in front of anterior border of PCL insertion
      • coronal plane
        • tunnel trajectory of < 75° from horizontal
          • obtain by moving tibial starting point halfway between tibial tubercle and posterior medial edge of tibia.
  • Graft placement
    • graft preconditioning
      • can reduce stress relaxation up to 50%
    • graft tensioning 
      • graft tensioning at 20N or 40N had no clinical outcome effects in a level 1 study
  • High tibial osteotomy
    • limb malalignment in both the coronal and sagittal plane must be addressed before or at the same time as ligament reconstruction
  • Revision ACL reconstruction
    • technique post
      • use high strength grafts (quad tendon, hamstring, allograft)
      • use dual fixation (suspension + interference screws)
      • bone grafting (tunnel dilation, decreased bone stock, staged prn)
      • reharvesting BTB contraindicated
    • postoperative
      • conservative rehab
Graft Selection
  • Bone patellar bone autograft post post
    • advantage of autograft
      • using patient's own tissue 
      • most common source of graft
      • faster incorporation
      • less immune reaction
      • no chance of acquiring someone else's infection
    • pros and cons of bone-patella-bone
      • longest history of use, considered the "gold standard"
      • bone to bone healing
      • ability to rigidly fix at the joint line (screws)
      • highest incidence of anterior knee pain (up to 10-30%)  
      • maximum load to failure is 2600 Newtons (intact ACL is 1725 Newtons)
    • complications
      • patella fracture (usually postop during rehab), patellar tendon rupture 
  • Quadruple hamstring autograft
    • technique
      • may be taken from contralateral side in revision situation when allograft is not desirable or available
    • pros and cons
      • smaller incision, less periop pain, less anterior knee pain 
      • fixation strength may be less than Bone-PT-Bone
      • maximum load to failure is approximately 4000 Newtons  
      • decreased peak flexion strength at 3 years compared to Bone-PT-Bone
      • concern about hamstring weakness in female athletes leading to increased risk of re-rupture
    • complications
      • "windshield wiper" effect (suspensory fixation away from joint line causes tunnel abrasion and expansion with flexion/extension of knee)
      • residual hamstring weakness
  • Allograft
    • pros & cons
      • useful in revisions
      • longer incorporation time
      • risk of disease transmission (HIV is < 1:1 million, hepatitis is even greater)
      • increased risk of re-rupture in in young athletes  
        • odds of graft rerupture are 4.3 x higher in allograft for athletes aged 10-19
    • graft processing
      • radiation3 Mrads is required to kill HIV (this however decreases the structural and mechanical properties of the graft)
      • freezing: destroys cells but does not affect strength of graft
  • Quadriceps tendon autograft
    • taken with patella bone plug
    • much less common
Pediatric Considerations
  • Physis
    • < 14 yrs with open physis
    • onset of menarche is best determinant of skeletal maturity in females 
  • Techniques
    • physis-sparing vs. transphyseal
    • no significant difference in growth disturbances between techniques
  • Graft Selection
    • transphyseal soft tissue grafts rarely lead to growth disturbances
  • Instrumentation
    • Factors found to increase physeal injury include: 
      • oblique tunnel position, interference screw fixation, high-speed tunnel reaming, and increasing tunnel diameter (>8mm) 
  • Early postoperative
    • immediate
      • aggressive cryotherapy (ice)
      • immediate weight bearing (shown to reduce patellofemoral pain)
      • emphasize early full passive extension (especially if associated with MCL injury or patella dislocation)
    • early rehab
      • focus rehab on exercises that do not place excess stress on graft 
        • appropriate rehab  
          • eccentric strengthening at 3 weeks has been shown to result in increased quadriceps volume and strength  
          • isometric hamstring contractions at any angle
          • isometric quadriceps, or simultaneous quadriceps and hamstrings contraction
          • active knee motion between 35 degrees and 90 degrees of flexion
          • emphasize closed chain (foot planted) exercises
        • avoid
          • isokinetic quadricep strengthening (15-30°) during early rehab
          • open chain quadriceps strengthening  
  • Injury prevention
    • female athlete
      • neuromuscular training / plyometrics (jump training)
      • land from jumping in less valgus and more knee flexion
      • increasing hamstring strength to decrease quadriceps dominance ratio
    • skier training
      • teach skiers how to fall
    • ACL bracing
      • no proven efficacy except for ACL-deficient skiers
  • Failure due to Tunnel Malposition
    • overview
      • is the most common cause of ACL failure    
      • improper tunnel placement causes failure in 70% 
    • femoral tunnel malposition
      • coronal plane
        • vertical femoral tunnel placement 
          • cause by starting femoral tunnel at vertical position in notch (12 o:clock) as opposed to lateral wall (9 o:clock)
          • will cause continued rotational instability which can be identified on physical exam by a positive pivot shift    
      • sagittal plane
        • anterior tunnel placement    
          • leads to a knee that is tight in flexion and loose in extension
          • occurs from failure to clear "residents ridge"
        • posterior misplacement (over-the-top)
          • leads to a knee that is lax in flexion and tight in extension
    • tibial tunnel malposition
      • sagittal plane
        • anterior misplacement
          • leads to knee that is tight in flexion with impingement in extension 
        • posterior misplacement
          • leads to an ACL that will impinge with the PCL
  • Other cause of failure
    • inadequate graft fixation
      • can be caused by graft-screw divergence >30 degrees 
    • missed diagnosis
      • in combined ACL and PLC injuries, failure to treat the PLC will lead to failure of ACL reconstruction
    • overaggressive rehab
  • Infection
    • septic arthritis
      • Staph aureus most common
      • presentation
        • pain, swelling, erythema, and increased WBC at 2-14 days postop
      • treatment
        • perform immediate joint aspiration with gram stain and cultures 
    • treatment
      • immediate arthroscopic I&D
      • often can retain graft with multiple I&Ds and abx (6 weeks minimum)
  • Loss of motion & arthrofibrosis 
    • preoperative prevention
      • be sure patient has regained full ROM before you operate ("pre-hab")  
      • wait until swelling (inflammatory phase) has gone down to reduce incidence of arthrofibrosis
    • operative prevention
      • proper tunnel placement is critical to have full range of motion
    • postop prevention
      • aggressive cryotherapy (ice)
    • treatment
      • < 12 weeks, then treat with aggressive PT and serial splinting
      • > 12 weeks, then treat with lysis of adhesions / manipulation under anesthesia
  • Infrapatellar contracture syndrome
    • an uncommon complication following knee surgery or injury which results in knee stiffness
    • physical exam will show decreased patellar translation    
  • Patella Tendon Rupture
    • will see patella alta on lateral radiograph 
  • RSD (complex regional pain syndrome)
  • Patella fracture
    • most fx occur 8-12 weeks postop
  • Hardware failure
  • Tunnel osteolysis
    • treat with observation
  • Late arthritis
    • related to meniscal integrity 
  • Local nerve irritation
    • saphenous nerve  
  • Cyclops lesion
    • fibroproliferative tissue blocks extension
    • "click" heard at terminal extension


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Qbank (59 Questions)

(SBQ07.14) During anterior cruciate ligament (ACL) reconstruction divergence between the graft and screw fixation within the bone tunnel can lead to complications. Which of the following statements regarding graft-screw divergence is true? Topic Review Topic

1. Risk of failure is eliminated using an accessory anteromedial drilling portal
2. Complications occur more commonly with soft tissue grafts
3. Loss of fixation becomes a greater risk if the graft-screw divergence is >30 degrees
4. Excessive graft-screw divergence more commonly occurs during tibial fixation
5. Graft-screw divergence is a common cause of late failure of ACL reconstructions

(SBQ07.37) You are considering performing an anterior cruciate ligament reconstruction on an adolescent female athlete but are concerned about the possibility of a resultant leg length discrepency. Which of the following history or physical findings is most reliable at predicting the amount of growth remaining? Topic Review Topic

1. Cessation of changes in shoe size
2. Onset of menarche
3. Secondary sex characteristics
4. Doubling the child’s height when she was 2 years of age to determine final height
5. Age at which patellar ossification began

(SBQ04.32) In biomechanical testing, which of the following tissues has the highest maximum load to failure? Topic Review Topic

1. Quadruple semitendinosus and gracilis tendons
2. Bone-patellar tendon-bone with a width of 10 mm
3. Bone-quadriceps tendon with a width on 10mm
4. Tibialis tendon allograft
5. Native anterior cruciate ligament (ACL)

(OBQ12.41) A genotype within the COL5A1 gene is associated with a reduced risk of which of the following injuries in women? Topic Review Topic

1. Glenohumeral dislocation
2. Rotator cuff tear
3. Lateral patellar dislocation
4. Anterior cruciate ligament rupture
5. Torn discoid meniscus

(OBQ12.94) Which of the following bone bruise patterns seen on magnetic resonance imaging (MRI) is most consistent with an anterior cruciate ligament (ACL) tear? Topic Review Topic

1. Medial tibial spine and medial femoral condyle
2. Medial facet of patella and lateral femoral condyle
3. Posterolateral tibia and lateral femoral condyle
4. Posterolateral tibia and medial femoral condyle
5. Medial tibial spine and lateral femoral condyle

(OBQ12.249) A 12-year-old female sustained a right knee injury during a high-level gymnastic competition. Physical examination revealed a significant effusion, positive anterior drawer, and 3+ Lachman. She is a Tanner 3 on the scale of physical development. When considering transphyseal reconstruction techniques, which of the following factors has the greatest potential to cause physeal injury in the tibia? Topic Review Topic

1. Vertical transphyseal tunnel position
2. Slow transphyseal tunnel reaming
3. Hamstring autograft
4. Small transphyseal tunnel diameter
5. Horizontal and oblique transphyseal tunnel position

(OBQ11.129) A patient develops infrapatellar contracture syndrome after undergoing ACL surgery. All of the following findings are consistent with this diagnosis EXCEPT? Topic Review Topic

1. Patella infera
2. Decreased patellar mobility
3. Loss of active but not passive flexion
4. Loss of full extension
5. Loss of passive flexion

(OBQ11.215) A 25-year-old male is one year status post anterior cruciate ligament (ACL) reconstruction using patellar bone-tendon-bone (BTB) autograft. He complains of persistent instability with certain activities. His operative dictation notes excellent stability intra-operatively with femoral fixation at the 12 o'clock position. Based on his femoral tunnel position, his history and examination are most likely to reveal which of the following? Topic Review Topic

1. Positive pivot shift test and instability with cutting activities due to failure to reconstruct the posterolateral bundle of the ACL
2. Positive Lachman's test and instability with forward running activites due to failure to reconstruct the anteromedial bundle of the ACL
3. Positive pivot shift test and instability with cutting activities due to failure to reconstruct the anterolateral bundle of the ACL
4. Positive Lachman's test and instability with forward activites due to failure to reconstruct the posteromedial bundle of the ACL
5. Positive pivot shift test and instability with forward running activities due to failure to reconstruct the posterolateral bundle of the ACL

(OBQ11.271) A 23-year-old soccer player suffers an ACL rupture and undergoes reconstruction. Post-operatively she begins a rehabilitation program and her therapist develops a series of knee conditioning exercises to help her regain strength and range of motion. Which of the following exercises places the lowest strain in this patients properly placed ACL graft? Topic Review Topic

1. Isometric hamstring contractions at 60 degrees of knee flexion
2. Isolated quadriceps contractions with the knee at 30 degrees of flexion
3. Simultaneous quadricep and hamstring contractions at 15 degrees of knee flexion
4. Isolated quadriceps contractions with the knee at 15 degrees of flexion
5. Active resisted knee motion from terminal extension to 30 degrees of flexion

(OBQ10.223) A collegiate men's basketball point guard undergoes ACL reconstruction with hamstring autograft. One year following reconstruction, he returns to playing and complains of recurrent instability episodes. He has an acute giving way episode on the court and is found to have an effusion and a positive pivot shift. Which of the following is the most likely cause of his injury? Topic Review Topic

1. Improper graft selection
2. Lack of sufficient physical rehabilitation prior to return to basketball
3. Overly aggressive physical rehabilitation during the first 3 months following reconstructive surgery
4. Surgical error in graft tensioning
5. Surgical error in tunnel position

(OBQ10.229) Which of the following exercises should typically be avoided during the initial therapy following ACL reconstruction? Topic Review Topic

1. Light leg press
2. Use of a stair climbing machine
3. Vertical squat with light dumbbells in each hand
4. Seated leg extensions
5. Use of a stationary bike

(OBQ09.26) A 31-year-old male is 1 year status post primary anterior cruciate ligament reconstruction. Despite adequate physical therapy, he has been unable to return to sport due to recurrent instability and elects to proceed with revision surgery. What is the most common reason for failure of his primary ACL reconstruction? Topic Review Topic

1. Unrecognized varus malalignment preop
2. Improper bone tunnel placement
3. Reconstruction with a single bundle
4. Improper graft selection
5. Meniscal injury

(OBQ09.147) Tunnel malposition is thought to be a primary etiology for ACL graft failure. All of the following are true of tunnel position EXCEPT: Topic Review Topic

1. Vertical placement of the femoral tunnel can result in rotational instability and impingement against the PCL
2. Anterior placement of the femoral tunnel can result in elongation of the graft
3. Tibial tunnel placement should be placed posterior to a line extending from Blumenstaat's line when the knee is in full extension
4. Transtibial drilling through a tibia tunnel that is too far anterior can result in a vertical (12:00) graft
5. Transtibial drilling through a tibia tunnel that is too far anterior can result in an oblique (10:30 or 1:30 position) graft

(OBQ08.120) A 25-year-old male undergoes an ACL reconstruction with an ipsilateral bone-patella tendon-bone autograft. At his two week followup he is noted to have complete loss of his extensor mechanism on exam, stable Lachman and posterior drawer tests, and patella alta radiographically. Management should consist of? Topic Review Topic

1. Continued standard ACL rehab protocol
2. Quadraceps tendon repair
3. WBAT in a cylinder cast
4. Patellar tendon repair or reconstruction
5. Revision ACL reconstruction with hamstring autograft

(OBQ08.186) Patients may complain of numbness over the anterolateral aspect of the knee following ACL reconstruction. This is most commonly due to injury of which of the following? Topic Review Topic

1. Suprapatellar branch of the saphenous nerve
2. Infrapatellar branch of the saphenous nerve
3. The common peroneal nerve
4. The superficial femoral nerve
5. The lateral femoral cutaneous nerve

(OBQ08.193) Strategies which focus on increasing patient neuromuscular control are most effective at preventing which of the following female sporting injuries? Topic Review Topic

1. Shoulder dislocations
2. Concussion
3. Anterior cruciate ligament ruptures
4. Frieberg's infarction
5. Patellofemoral instability

(OBQ08.213) When comparing autologous graft options for ACL reconstruction, a hamstring graft is associated with which of the following findings when compared to a patellar tendon graft? Topic Review Topic

1. Decreased tunnel widening
2. Decreased pivot shift
3. Decreased incidence of anterior knee pain
4. Increased knee flexion strength on Cybex testing
5. Increased stability on KT-1000

(OBQ07.66) A 16-year-old high school basketball player sustains a non-contact knee injury when she lands from a rebound. She develops immediate swelling and is noted to have a hemarthrosis. What is the most likely diagnosis? Topic Review Topic

1. MCL tear
2. Medial meniscus tear
3. ACL tear
4. Patellar dislocation
5. Contusion

(OBQ07.87) A patient sustains a knee injury. The MRI image shown in Figure A is indicative of which of the following injuries? Topic Review Topic
FIGURES: A          

1. ACL tear
2. PCL tear
3. Medial meniscus tear
4. Lateral meniscus tear
5. Patellar tendon tear

(OBQ07.155) Increased ACL injury rates in women athletes compared to male athletes may be due to muscular imbalance and relative weakness in which of the following muscle groups? Topic Review Topic

1. Quadriceps
2. Hamstrings
3. Gluteus muscles
4. Adductors
5. Abdominals

(OBQ07.274) Which of the following risk factors is felt to contribute greatest to the higher rate of ACL rupture in female compared to male athletes? Topic Review Topic

1. Body mass index
2. Femoral notch width
3. Generalized ligamentous laxity
4. Neuromuscular factors
5. Limb alignment

(OBQ06.112) A 25-year-old male soccer player twisted his left knee 4 days ago and developed immediate swelling and pain. On exam, he has a 2+ effusion and pain with active range of motion. Passively, he tolerates range of motion from 0-90 degrees. He has difficulty performing a straight leg raise exercise. MRI scan is shown in Figure A. What is the most appropriate initial management for his injury? Topic Review Topic
FIGURES: A          

1. Knee immobilization
2. Physical therapy for range of motion and strength
3. Acute reconstruction followed by mobilization
4. Arthrocentesis to rule out infection
5. Rest, nonsteroidal anti-inflammatories, and follow-up in 4 weeks

(OBQ06.138) Following ACL reconstruction, which of the following tests most closely correlates with patient satisfaction with their reconstructed knee? Topic Review Topic

1. KT-1000 manual maximum value
2. Lachman's test
3. Anterior drawer test
4. Pivot shift test
5. Cybex testing

(OBQ06.177) A patient develops anteromedial pain and altered sensation over the anterolateral infrapatellar region of the knee after autologous hamstring tendon harvest for an ACL reconstruction. Which of the following nerves has been injured? Topic Review Topic

1. Medial retinacular
2. Inferior genicular
3. Saphenous
4. Superficial peroneal
5. Tibial

(OBQ05.28) At what range of motion do seated leg extension exercises place the greatest amount of stress on the anterior cruciate ligament? Topic Review Topic

1. 0 to 30 degrees
2. 30 to 60 degrees
3. 60 to 90 degrees
4. 90 to 120 degrees
5. flexion greater than 120 degrees

(OBQ05.40) During anterior cruciate ligament reconstruction, a graft that is tight in flexion but lax in extension may be due to which technical error? Topic Review Topic

1. Femoral tunnel is too posterior
2. Femoral tunnel is too anterior
3. Femoral tunnel placed at 12:00 position
4. Tibial tunnel is too anterior
5. Tibial tunnel is too medial

(OBQ05.96) Most surgeons prefer to avoid or limit which of the following exercises in the initial post-operative rehabilitation following ACL reconstruction? Topic Review Topic

1. Quadriceps sets
2. Seated leg extensions
3. Straight leg raises
4. Active range of motion
5. Closed chain exercises

(OBQ05.174) A high school girls basketball player sustains a non-contact knee injury and develops an acute hemarthrosis. What is the likelihood that she has an ACL tear? Topic Review Topic

1. 0-15%
2. 15-30%
3. 30-45%
4. 45-60%
5. >60%

(OBQ05.190) The middle genicular artery is the primary blood supply of which of the following structures? Topic Review Topic

1. Medial collateral ligament
2. Lateral collateral ligament
3. Medial meniscus
4. Lateral meniscus
5. Anterior cruciate ligament

(OBQ05.214) All of the following are true regarding excessively anterior femoral tunnel placement during ACL reconstruction EXCEPT? Topic Review Topic

1. It may cause loss of knee flexion
2. It may cause graft over-stretching and failure
3. It is the most common technical error
4. It may cause interference screw divergence
5. It is often due to poor visualization

(OBQ04.9) When evaluating patients that needed revision surgery, what is the most common cause of a failed primary ACL reconstruction? Topic Review Topic

1. Tunnel malposition
2. Obesity
3. Smoking
4. Returning to sport too early
5. Inadequate physical therapy

(OBQ04.19) You are called by a 35-year-old male patient who had ACL reconstruction with hamstring autograft 5 days ago. He reports his knee pain and swelling have significantly increased in the last day, and now it is difficult for him to raise his leg off the bed and is having more difficulty tolerating the CPM machine. Upon questioning he denies fever, chills, or any new trauma to the knee. What is the next step in management? Topic Review Topic

1. Ice, NSAIDS, elevation, compression wrap and restart therapy once symptoms improve
2. Go to the ER immediately for knee aspiration with gram stain and cultures
3. Increase CPM use to 10 hours a day
4. Call the office staff in the morning to schedule an appointment
5. Start physical therapy visits once daily

(OBQ04.56) An 18-year-old athlete is now 3 months out from anterior cruciate ligament reconstruction. He has been unable to obtain full extension of the knee. His range of motion is from 12° to 125° compared to 0° to 140° on the contralateral knee. He has no effusion, no pain at rest, and a stable Lachman’s test. He is having difficulty ambulating without crutches. What is the most common technical error which can account for these findings? Topic Review Topic

1. Femoral tunnel drilled too anteriorly
2. Failure to cycle the knee prior to final tibial fixation
3. Femoral tunnel drilled too vertically
4. Tibial tunnel drilled too vertically
5. Tibial tunnel drilled too anteriorly

(OBQ04.91) A 30 year-old tennis player sustains the injury seen in Figure A and is considering nonoperative treatment of this injured structure. With nonoperative treatment, which of the following additional findings correlate most closely with the development of future arthritis? Topic Review Topic
FIGURES: A          

1. Grade IIB Lachman
2. Presence of pivot shift
3. Tenderness over MCL origin without opening on valgus
4. Positive Ober test
5. Painful pop on McMurray test

(OBQ04.174) Which of the following factors concerning ACL reconstruction has demonstrated definitive evidence of adverse effect on clinical outcomes? Topic Review Topic

1. Center of tibia tunnel placement in-line with the posterior aspect of the anterior horn of the lateral meniscus
2. Horizontal femoral tunnel placement (10 or 2 o’clock position)
3. Femoral tunnel placement anterior to the lateral intercondylar ridge
4. One-incision instead of two-incision tunnel drilling technique
5. Tibial tunnel is parallel and posterior to Blumenstaat's line when knee is fully extended

(OBQ04.212) A 16-year-old female volleyball player presents 1 week after sustaining a knee injury while landing from a jump. There was an audible popping sound at the time of injury and she developed swelling later that evening. On physical examination, the surgeon applies a valgus force to the fully extended and internally rotated knee. As the knee is then brought into flexion, a loud clunk occurs at 30° of flexion. Which of the following patterns of bone contusion shown on MRI in Figures A-E is most likely to be evident on this patient's MRI? Topic Review Topic
FIGURES: A   B   C   D   E  

1. Figure A
2. Figure B
3. Figure C
4. Figure D
5. Figure E

(OBQ04.240) In laboratory testing of quadrupled hamstring grafts (doubled over semitendinosis and gracilis), all of the following statements are true EXCEPT: Topic Review Topic

1. Two equally tensioned semitendinosus strands have an average of 220 percent of the strength of one semitendinosus strand
2. Single semitendinosis strand has a higher tensile strength than a single gracilis strand
3. All strands of a hamstring graft must be equally tensioned to achieve optimum biomechanical properties
4. Quadrupled grafts have tensile properties that are higher than 10mm patellar-ligament grafts
5. Quadrupled hamstring grafts have lower tensile strength than the native ACL

(OBQ04.246) A 23-year-old soccer player sustains an anterior cruciate ligament (ACL) tear and is scheduled for reconstruction. He has questions regarding the use of autografts. Which of the following statements is true regarding bone-patellar tendon-bone (BTB) autograft in comparison to quadrupled hamstring autograft for ACL reconstruction? Topic Review Topic

1. BTB autograft is biomechanically stronger than quadrupled hamstring autograft
2. BTB autograft shows less evidence of post-operative pivot shift
3. Quadrupled hamstring autograft shows lower rate of graft failure
4. BTB shows higher incidence of anterior knee pain
5. Quadrupled hamstring autograft shows lower incidence of knee hardware removal

(OBQ04.258) The saphenous nerve is most likely to be injured with which of the following steps during an anterior cruciate ligament (ACL) reconstruction with hamstring autograft? Topic Review Topic

1. Incision for an anteromedial portal with the knee flexed
2. Incision for an anteromedial portal with the knee extended
3. Incision for an accessory medial portal the with knee flexed
4. Hamstring harvest with the knee extended
5. Tibial tunnel aperture fixation with the knee at 30 degrees of flexion