pcl injury keith wolstenholme md, frcsc. pcl anatomy and function pcl travels – from posterior...
TRANSCRIPT
PCL InjuryKeith Wolstenholme MD, FRCSC
PCL Anatomy and Function
• PCL travels– from posterior fovea of tibia (1.5cm inferior to
joint line)– to lateral border of anteromedial femoral condyle– Intrarticular structure
• Restrict posterior tibial translation (esp. at 90º)
• 2º restraint to varus/valgus, external rotation
PCL anatomy
• Average length: 32-38 mm• Cross Sectional Area:
– 31.2 mm2
• 1.5 x that of ACL
• Insertional cross sectional area:– 3x larger than midsubstance– Makes anatomical reconstruction difficult
Blood Supply PCL
•Middle Geniculate
Artery
Anatomy
• Functionally two bundles– Posteromedial
Tightens in extension, loosens in flexion
– Anterolateral (this is one reconstructed in single bundle recons)
• Tightens in flexion, loosens in extension
Anatomy
• Femoral Insertion:– Broad insertion:
• 88° ± 5.5° angle to the roof
– Midpoint of femoral insertion:
• 1 cm proximal to articular cartilage of MFC
Anatomy
• Tibial Insertion:– 1.0 -1.5cm inferior to posterior rim of tibia– PCL facet
Meniscofemoral Ligaments(Originate from Lateral Meniscus)
• Anterior (Humphrey)-74%• May be confused for PCL during arthroscopy
• Posterior (Wrisberg)-69%– Larger – Stronger (as strong as posteromedial bundle)
• *93% of people have at least one present• 17.2% femoral footprint of PCL can be
meniscofemoral ligaments• Provide a variable resistance to posterior stress
at 90º of flexion– Nagasaki AJSM 2006
Epidemiology
• Incidence varies: – 1%-44% of all acute knee injuries depending on severity
and energy (Harner AJSM 1999)
• NFL Combines:– 2% incidence in asymptomatic knees
– (Parolie and Bergfeld, AJSM 1986)
• Lower incidence in sports with less contact
Mechanism
• Hyperflexion with plantarflexed foot• Pretibial trauma in hyperflexed knee• “dashboard” injury (MVA)
+ rotation or varus = PLC injury
**History: not usually “pop” or “tear”
Exam
• Mild to moderate effusion (acute)• Mild limp• Pain in back of knee• Lack ~10-20º of terminal flexion• Chronic PCL tear:
– Difficulty walking up or down inclines
Exam
• Inspection:– Sag compared to other knee
• Quadriceps active drawer test– Knee 90° flexed– Stabilize foot– Fire quads
Exam
• Most accurate: – Posterior drawer test
• 90° flexion – Neutral– Internal rotation– External rotation
• Isolated PCL tear:-less translation with internal
rotation• MCL/POL ligament 2°
stabilizers
Classification
• Grade I: 0-5mm– Tibial plateau anterior to femoral condyle
• Grade II: 5-10mm– Tibial plateau flush with condyle
• Grade III: 5-15mm– Tibial plateau posterior to condyle– Often combined injuries
Imaging
• Should get plain x-rays to look for:– Other injuries– PCL avulsion fracture– Posterior translation on lateral film
• MRI can be used for:– Confirming diagnosis– Assessing other intra-articular pathology
Natural History of PCL Injury
• Geissler et al (AJSM, 93).– 33 acute and 55 chronic patients.– 4X greater chondral injuries and 2X greater meniscal
tears in chronic patients.
• Clancy et al (JBJS, 83) & Keller et al (AJSM, 93)– Higher incidence of medial femoral condyle and
patellofemoral chondrosis.
Nonoperative Treatment
• Indicated for isolated Grade I/II PCL tears– Early ROM exercises– **Quadriceps strengthening
• Counteracts posterior tibial subluxation
– Expect return to play by 3-6 weeks
• Some authors advocate immobilization in extension for isolated grade 3 PCL tears for 2-4 weeks to decrease posterior sag
Non-op results
• Horibe JBJS Br 1995– 22 Isolated PCL injuries in athletes– 15 treated non-operatively with resumption of
sport• 14 returned to previous level of athletic activity
• Fowler AJSM 1987– 13 patients treated non-operatively– All returned to sport by 2.6 yrs post injury
Non op results
• Shelbourne (AJSM, 99).– 133 patients isolated PCL questionnaires– 68 examined @ 5.4 yr follow up.– Laxity did not correlate with outcome.– 1/2 patients returned to sport at same level, 1/3 at
lower level, 1/6 did not return.– Grade III injuries not included.
Surgical Indications
• surgical intervention is recommended for:– the PCL/PLC-deficient knee with >10 mm
increased posterior translation and ≥15° increased external rotation
• Symptomatic Grade III laxity• Displaced bony avulsion fractures
– Matava JAAOS 2009
Surgical techniques / results
• There are NO randomized trials comparing different methods of surgical treatment– Transtibial vs tibial inlay– Single bundle vs double bundle
Current Popular Techniques
• Tibial tunnel
• Tibial inlay
Tibial Tunnel Technique
• Done arthroscopically via 70º scope– PM portal
• C-arm to check guide wire placement• Femoral tunnel via:
– Inside out– Outside in
• If single bundle technique: – recreate AL bundle
Tibial Inlay
• Arthroscopic femoral tunnel placement
• Avoids ‘killer curve’• Open exposure for tibial
inlay technique via Burks approach – (Between medial head of
gastrocnemius and ST)
Burks ApproachWind et al, AJSM 2004
ST
Double-Bundle Reconstruction Technique
• Both AL (90º) and PM (30º) bundles• Achilles tendon allograft commonly used
– Better knee kinematics through full ROM in anatomic study**
– Posterior tibial translation decreased up to 3.5 mm compared to single-bundle reconstruction
• Technically more demanding?
**Harner et al, AJSM 2000
Results (retrospective reviews)
• MacGillivray Arthroscopy 2006– 20 patients, Inlay vs. transtibial – no difference at
minimum 2 years• No difference subjective or objective
• Seon Arthroscopy 2006– 43 patients each group, inlay vs. transtibial – no difference
at minimum 2 years• No difference objective physical exam or radiographic
Watsend J Knee Surg 2009
• Systematic Review• “The generally low methodological quality of
studies on PCL injury shows that caution is required when interpreting results after management of injury to the PCL.
• Firm recommendations on what treatment to choose cannot be given at this time on the basis of these studies”
Conclusions
• PCL is an important restraint to posterior tibial translation
• Most injuries are successfully treated non-operatively
• Refractory or combined injuries are often treated with surgery
• No clear advantage to any one surgical technique