import { OnePagerSummary, ContentSection, ExamWarning, InfoCardGrid, InfoCard, EvidenceCard, ComparisonTable, VivaScenario, MnemonicCard, ExamCheatSheet, Tab, Tabs } from '@/components/mdx' The **posterolateral corner (PLC)** of the knee is a complex anatomic region consisting of **static** (ligaments) and **dynamic** (musculotendinous) stabilizers that resist **varus** and **external rotation** forces. Understanding PLC anatomy is CRITICAL for successful reconstruction and avoiding common peroneal nerve injury. ### Posterolateral Corner Static Stabilizers **1. LATERAL COLLATERAL LIGAMENT (LCL - PRIMARY VARUS RESTRAINT):** **Anatomy:** - **Origin**: Lateral femoral epicondyle (proximal and posterior to popliteus origin) - **Insertion**: Fibular head (lateral aspect, just posterior to biceps femoris insertion) - **Length**: Mean 69mm (range 60-80mm - LaPrade 2003) - **Function**: **PRIMARY restraint to varus stress** at all knee flexion angles (resists 55-70% of varus load at 0° and 30° - Gollehon 1987) **Biomechanics:** - **Isometric through ROM**: LCL maintains constant length from 0-90° flexion (isometric ligament - ideal for reconstruction) - **Tightest at 0° extension** (maximum varus stability) - **Varus laxity with LCL injury**: 5-10mm at 30° flexion (Grade II), greater than 10mm (Grade III) **2. POPLITEUS TENDON (PRIMARY EXTERNAL ROTATION RESTRAINT):** **Anatomy:** - **Origin**: Popliteal sulcus on lateral femoral condyle (anterior and distal to LCL origin) - **Course**: Runs POSTERIOR and INFERIOR from femur, passes through **popliteal hiatus** (opening in lateral joint capsule) - **Insertion**: Posterior tibia (popliteal line above soleal line) - **Function**: **PRIMARY restraint to external rotation** of tibia (resists 50-60% of external rotation load at 30° - Shahane 1999) **Clinical Significance:** - Popliteus contracts during knee flexion to "unlock" knee (externally rotates femur on fixed tibia) - Injury causes increased external rotation (dial test positive - greater than 10° asymmetry at 30° flexion) **3. POPLITEOFIBULAR LIGAMENT (SECONDARY EXTERNAL ROTATION RESTRAINT):** **Anatomy:** - **Origin**: Popliteus musculotendinous junction (proximal aspect of popliteus muscle belly) - **Insertion**: Fibular styloid (apex of fibular head) - **Function**: Connects popliteus muscle to fibular head, **secondary restraint to external rotation** and **primary restraint to posterior translation of lateral tibial plateau** (Shahane 1999) **Biomechanics:** - Popliteofibular ligament tightens in extension (prevents posterior subluxation of lateral tibial plateau) - Injury contributes to posterolateral rotatory instability (PLRI) - positive dial test at BOTH 30° and 90° flexion **4. ARCUATE LIGAMENT COMPLEX:** **Anatomy:** - **Y-shaped fibrous structure** that reinforces posterior joint capsule - Originates from fibular styloid, fans out to attach to **lateral femoral condyle** (superior limb) and **posterior joint capsule** (medial limb) - Often absent or attenuated (present in only 80% of knees - Seebacher 1982) **Function:** - Contributes to posterior capsular stability - Secondary restraint to varus and external rotation ### Dynamic Posterolateral Stabilizers **1. BICEPS FEMORIS:** **Anatomy:** - **Long head**: Originates from ischial tuberosity - **Short head**: Originates from linea aspera of femur - **Insertion**: Fibular head (lateral aspect) - forms **conjoined tendon** with LCL insertion - **Function**: Dynamic varus and external rotation stabilizer (muscle contraction reinforces LCL function) **Clinical Significance:** - Biceps femoris injury often accompanies LCL tears (conjoined insertion - both avulsed together in severe trauma) **2. ILIOTIBIAL BAND (ITB):** **Anatomy:** - Extension of tensor fascia lata - Inserts on **Gerdy's tubercle** (anterolateral tibial plateau) - Posterior fibers blend with lateral intermuscular septum and superficial capsule **Function:** - Provides anterolateral stability - Secondary varus restraint (when knee in extension) **3. LATERAL HEAD OF GASTROCNEMIUS:** **Anatomy:** - Origin: Posterior lateral femoral condyle (posterior to LCL femoral attachment) - Crosses posterior to lateral joint line **Function:** - Dynamic posterior capsular restraint - May be injured in severe PLC trauma (posterolateral capsule avulsion) ### Neurovascular Anatomy **COMMON PERONEAL NERVE (PRIMARY HAZARD):** **Course:** - Branches from **sciatic nerve** at apex of popliteal fossa (varies: high division in 10-15% of patients - sciatic bifurcates proximal to popliteal fossa) - Descends along **medial border of biceps femoris** in distal thigh - Passes **LATERALLY** across popliteal fossa toward fibular neck - Crosses **fibular neck** 2cm distal to fibular head apex (Flandry 1991) - **DIRECTLY ADHERENT** to fibular neck periosteum (no intervening soft tissue - highest injury risk zone) **Branches:** - **Articular branch** to knee joint (proximal to fibular neck) - **Lateral sural cutaneous nerve** (proximal leg sensation) - **Superficial peroneal nerve** (ankle eversion + dorsolateral foot sensation) - separates at fibular neck - **Deep peroneal nerve** (ankle/toe dorsiflexion + first web space sensation) - separates at fibular neck **Injury Manifestations:** - **Foot drop** (ankle/toe dorsiflexion weakness - tibialis anterior, EHL, EDL, peroneus tertius) - **Weak ankle eversion** (superficial peroneal nerve - peroneus longus/brevis) - **Steppage gait** (high stepping to clear foot) - **Sensory loss**: Dorsum of foot and lateral leg **Protection Strategy:** - **Identify nerve FIRST** before any dissection around fibular head - Palpate nerve as **cord-like structure** 2cm distal to fibular head (crosses fibular neck) - Use blunt dissection ONLY around nerve (sharp dissection risks transection) - Retract nerve ANTERIORLY during fibular head exposure (protects from retractors and drilling) **POPLITEAL VESSELS:** - Lie **MEDIAL** to posterolateral approach (15-20mm medial to fibular head) - Usually NOT at risk with standard posterolateral dissection (stay lateral to neurovascular bundle) - May be injured in severe trauma (knee dislocation, tibial plateau fracture with PLC involvement) **Most vulnerable structure**: The CPN is the SINGLE MOST VULNERABLE structure during posterolateral approach (2-10% iatrogenic injury rate - LaPrade 2008) **Anatomy - why high risk**: - Crosses fibular neck **2cm distal to fibular head apex** (Flandry 1991) - **DIRECTLY ADHERENT** to fibular neck periosteum (no intervening soft tissue) - Lies **ANTERIOR** to biceps femoris tendon at fibular neck level **Surgical protection strategy**: 1. **Identify CPN FIRST** before ANY dissection around fibular head - Palpate as cord-like structure 2cm distal to fibular head - Feel nerve roll under skin with gentle finger pressure 2. **Skin incision POSTERIOR to fibular head** - Avoids nerve which is anterior to biceps at this level 3. **Dissect along POSTERIOR border of biceps femoris** - Nerve lies ANTERIOR to biceps - Staying posterior protects nerve 4. **Use BLUNT dissection only at fibular neck** - Sharp dissection risks transection (nerve adherent to bone) - Never use knife/scissors directly on fibular neck 5. **Retract nerve ANTERIORLY during fibular head work** - Use vessel loop or rubber drain - Protects from retractors and drilling 6. **NEVER drill blind into fibular head** - Nerve 2cm distal - drill penetration risks injury - Always visualize drill trajectory away from nerve **Clinical pearl - difficult cases**: - Unable to palpate nerve (obese, scarred)? Use **nerve stimulator** - Low current (0.5-1.0mA) causes foot dorsiflexion - Confirm nerve location before dissection **CPN injury presentation**: - Foot drop (tibialis anterior 0/5) - Weak toe extension (EHL, EDL 0-2/5) - Sensory loss first web space (superficial peroneal distribution) - Requires immediate exploration if immediate postop **Anatomy**: Popliteal artery and vein lie **15-20mm MEDIAL** to fibular head in popliteal fossa **Safe zone principle**: Stay **LATERAL** to interval between biceps femoris (lateral) and semimembranosus/semitendinosus (medial) **Danger zone**: MEDIAL popliteal fossa - Popliteal artery (deepest structure) - Popliteal vein (superficial to artery) - Tibial nerve (most superficial, lies on vessels) **Surgical strategy**: - Avoid excessive **MEDIAL dissection** beyond popliteal fossa midline - If dissecting medially, stay superficial to deep fascia - Respect biceps-hamstring interval as lateral boundary **Vascular injury recognition**: - Diminished/absent distal pulses - Expanding hematoma - Pulsatile bleeding - Cold, pale foot **Management if suspected vascular injury**: 1. **BEFORE surgery**: Vascular surgery consultation if trauma with diminished pulses 2. **DURING surgery** if artery injured: - IMMEDIATELY control with proximal/distal pressure - Call vascular surgery STAT - Primary repair or interposition graft required 3. **Time is critical**: 10-15% amputation rate if repair delayed greater than 6 hours (ischemia threshold) **Prevention**: - Limit medial dissection to visualization of popliteus muscle - Use blunt dissection near medial structures - Ensure good hemostasis to avoid expanding hematoma ### Patient Positioning **Setup:** - **Supine** position on operating table - **Bump or sandbag** under ipsilateral hip (elevates posterolateral knee - improves access) - **Leg holder or post** at medial thigh (allows knee flexion and varus stress for PLC exposure) - **Alternative**: Lateral decubitus position with affected leg up (better for isolated PLC surgery, but difficult for combined ACL/PLC reconstruction) - **Tourniquet** on proximal thigh (250-280mmHg for 90-120 minutes) - optional (many surgeons avoid tourniquet to allow nerve stimulator use if needed) ### Incision and Superficial Dissection **Skin Incision:** - **Longitudinal incision** from **distal femur to proximal fibular shaft** - **Course**: Centered over fibular head, extends **posteriorly** (NOT directly lateral - avoids common peroneal nerve) - **Proximal extent**: 8-10cm proximal to fibular head (allows LCL femoral attachment exposure) - **Distal extent**: 4-5cm distal to fibular head (exposes fibular neck and peroneal nerve crossing) - **Length**: Typically 12-15cm **Landmarks:** - Palpate **fibular head** (prominent bony landmark on lateral knee) - Palpate **biceps femoris tendon** (posterior to fibular head insertion) - Mark incision **posterior to fibular head** (stays behind nerve which lies anterior to biceps at neck level) **Superficial Dissection:** 1. **Incise skin and subcutaneous tissue** sharply 2. **Identify iliotibial band (ITB)** anteriorly (thick fascial layer) 3. **Identify biceps femoris tendon** posteriorly (palpable cord inserting on fibular head) 4. **Develop plane between ITB (anterior) and biceps femoris (posterior)** - This interval provides access to underlying LCL and lateral joint capsule - ITB pulled anteriorly with retractors, biceps pulled posteriorly ### Deep Dissection - Common Peroneal Nerve Identification (CRITICAL STEP) **STEP 1: PALPATE COMMON PERONEAL NERVE (Before Deep Dissection):** - Use **fingers to palpate cord-like structure** crossing fibular neck 2cm distal to fibular head apex - Roll nerve under fingers (feels like electrical cord - firm, mobile structure) - If unable to palpate (obese patient, scarring): Use **nerve stimulator** at low current (0.5-1.0mA) to locate nerve (stimulation causes foot dorsiflexion) **STEP 2: EXPOSE COMMON PERONEAL NERVE:** - Follow **posterior border of biceps femoris** distally (nerve lies ANTERIOR to biceps at this level) - Dissect along biceps with **blunt technique** (finger dissection or Kittner dissector) - Identify nerve at fibular neck crossing - **DIRECTLY ADHERENT to fibular neck periosteum** - Use **blunt dissection ONLY** to free nerve from fibular neck (sharp dissection risks transection) - Encircle nerve with **vessel loop or rubber drain** for protection **STEP 3: RETRACT NERVE ANTERIORLY:** - Gently retract nerve ANTERIORLY away from surgical field using vessel loop - **Minimize retraction time** (nerve sensitive to ischemia from prolonged traction) - Release retraction periodically during case (every 20-30 minutes) ### Posterolateral Corner Exposure **After Nerve Protected:** **1. Expose Fibular Head:** - Biceps femoris insertion on fibular head (lateral aspect) identified and protected - LCL insertion on fibular head (posterior to biceps) identified - **Subperiosteal elevation** of soft tissues from fibular head if drilling needed (eg biceps/LCL avulsion repair) **2. Identify LCL:** - **Proximal**: Palpate lateral femoral epicondyle (LCL femoral attachment) - **Distal**: Follow LCL to fibular head insertion (posterior to biceps insertion) - LCL runs in ANTERIOR-TO-POSTERIOR direction (from femoral epicondyle to fibular head) - Assess LCL integrity (palpate for midsubstance tear, femoral avulsion, fibular avulsion) **3. Expose Popliteus Tendon:** - Locate **popliteal hiatus** (opening in lateral joint capsule posterior to LCL) - Popliteus tendon emerges from hiatus, courses to popliteal sulcus on lateral femoral condyle - Use **blunt dissection** to expose popliteus (avoid sharp dissection - risks capsule violation and fluid extravasation) **4. Identify Popliteofibular Ligament:** - Originates from **popliteus musculotendinous junction** (proximal muscle belly) - Inserts on **fibular styloid** (apex of fibular head) - Often attenuated or difficult to identify in acute injuries (merged with hematoma) - May need to define anatomy by identifying fibular styloid insertion then tracing proximally to popliteus ### PLC Reconstruction Techniques **ANATOMIC PLC RECONSTRUCTION (LaPrade Technique - GOLD STANDARD):** **Indications:** - **Grade III PLC injury** (complete tear with varus laxity greater than 10mm at 30° flexion) - **Chronic PLC insufficiency** (varus thrust gait, dial test positive greater than 10° asymmetry) - **Combined with ACL or PCL reconstruction** (60-80% of PLC injuries are multiligament - Fanelli 2005) **Graft Options:** - **Allograft** (most common): Achilles tendon (bone block for fibular head), tibialis anterior, semitendinosus - **Autograft**: Hamstring (if not needed for ACL), quadriceps tendon **Technique (LaPrade Anatomic Reconstruction):** **LCL Reconstruction:** 1. **Femoral tunnel**: Drill 7mm tunnel at anatomic LCL origin on lateral femoral epicondyle (proximal and posterior to popliteus origin) 2. **Fibular tunnel**: Drill 7mm tunnel through fibular head (lateral to anterior - exits anterior fibular neck, AVOIDING peroneal nerve 2cm distal) 3. **Graft passage**: Pass graft (eg semitendinosus allograft) through femoral tunnel (femur to fibula), fix femoral side with interference screw or suspensory button 4. **Tensioning**: Tension graft with knee at 30° flexion, neutral rotation, slight varus stress (restores isometric LCL length) 5. **Fibular fixation**: Fix with interference screw or suture anchor on fibular head **Popliteofibular Ligament Reconstruction:** 1. **Popliteus tunnel**: Drill 7mm tunnel at anatomic popliteus origin in popliteal sulcus (anterior and distal to LCL femoral origin) 2. **Fibular styloid fixation**: Attach graft (separate limb or shared with LCL graft) to fibular styloid using suture anchor or bone tunnel 3. **Graft passage**: Pass graft through popliteus tunnel (posterior to LCL graft - recreates popliteus course) 4. **Tensioning**: Tension with knee 60-70° flexion, neutral rotation (popliteus/popliteofibular tightest in flexion) **Popliteus Tendon Reconstruction (If Needed):** - Drill tunnel from popliteal sulcus to posterior tibia (popliteal line insertion) - Pass graft through tunnel, fix on posterior tibia with interference screw - Rarely performed in isolation (usually combined with LCL + popliteofibular reconstruction) **Post-Operative Protocol:** - **Hinged knee brace** locked in extension for 2 weeks - **Partial weight-bearing** (toe-touch) for 6 weeks - **ROM**: 0-90° for first 6 weeks (NO deep flexion - protects popliteus reconstruction) - **Full ROM** at 6-8 weeks, strengthening at 8-12 weeks - **Return to sport**: 9-12 months (ACL timeline if combined) ### Indications for Posterolateral Approach **PLC RECONSTRUCTION (PRIMARY INDICATION):** **Grade III PLC Injury (Operative Indication):** - **Varus laxity**: Greater than 10mm opening at 30° knee flexion vs contralateral (Grade III) - **Dial test**: Greater than 10° external rotation asymmetry at 30° and/or 90° flexion - **External rotation recurvatum test**: Positive (tibia externally rotates and hyperextends vs contralateral) - **Mechanism**: Hyperextension + varus force, dashboard injury (knee hitting dashboard in MVA), sports trauma **Combined Ligament Injuries (60-80% of PLC Injuries):** - **ACL + PLC** (35%): Varus hyperextension injury - **PCL + PLC** (25%): Dashboard injury (posterior force + varus) - **ACL + PCL + PLC** (15%): Knee dislocation - **Reconstruction timing**: SIMULTANEOUS reconstruction (NOT staged - 10% vs 32% failure - Levy 2010) **Grade I-II PLC Injuries (Non-Operative):** - Varus laxity less than 5mm (Grade I) or 5-10mm (Grade II) at 30° flexion - Dial test less than 10° asymmetry - **Management**: Hinged knee brace (blocks varus), physiotherapy for quad/hamstring strengthening (dynamic stabilizers) - **Outcomes**: 80-85% successful with non-operative management (Indelicato 1990) **FIBULAR HEAD FRACTURES:** **Avulsion Fractures (LCL/Biceps Insertion):** - **Large fragment** with LCL/biceps attachment displaced greater than 5mm - ORIF via posterolateral approach - **Fixation**: Lag screws, plate, or suture anchors depending on fragment size - **Outcomes**: 90-95% union with anatomic reduction and stable fixation **Comminuted Fibular Head Fractures:** - Usually part of **Schatzker IV tibial plateau fracture** (lateral plateau split + fibular head) - Posterolateral approach for fibular head fixation, separate approach for tibial plateau (anterolateral or lateral) **COMMON PERONEAL NERVE EXPLORATION:** **Indications:** - **Iatrogenic nerve injury** during knee surgery (immediate post-op foot drop with pre-op intact function) - **Traumatic nerve injury** with knee dislocation or fibular neck fracture (foot drop at presentation) - **Delayed nerve palsy** without recovery by 4-6 months (EMG shows no reinnervation) **Exploration Findings:** - Nerve contusion/neurapraxia (nerve in continuity - most common): **Neurolysis** (free from scar) - Nerve laceration/neurotmesis (complete transection): **Primary repair** (if less than 1cm gap) or **nerve graft** (sural nerve autograft if greater than 1cm gap) **Outcomes:** - Neurolysis (contusion): 80% functional recovery - Primary repair: 60% functional recovery - Nerve graft: 40% functional recovery ### Outcomes by Procedure **Anatomic PLC Reconstruction (LaPrade Technique):** - **Clinical**: Lysholm 88, IKDC 78% normal/nearly normal (LaPrade 2014) - **Objective stability**: Varus laxity 12mm → 2mm, dial test asymmetry 15° → 3° - **Graft failure**: 12% (revision required) - **Return to sport**: 72% return to pre-injury level - **Complications**: 5% transient peroneal nerve palsy (all recovered by 6 months) **Combined ACL + PLC Reconstruction:** - **Simultaneous**: 10% graft failure, Lysholm 87, IKDC 82% normal (Levy 2010) - **Staged**: 32% graft failure (3-fold higher - NOT recommended) **Non-Anatomic PLC Reconstruction (Historical):** - **Biceps tenodesis** or **single-structure reconstruction** (LCL only): 30-40% failure rate - **Abandoned** in favor of anatomic reconstruction (LCL + popliteofibular - LaPrade technique) **Fibular Head Fracture ORIF:** - **Union rate**: 90-95% with anatomic reduction and stable fixation - **Nonunion**: 5% (usually with inadequate fixation or severe comminution) - **Peroneal nerve injury**: 10-15% at presentation (associated with fracture), 2-5% iatrogenic during surgery ### Intraoperative Complications **1. COMMON PERONEAL NERVE INJURY (2-10% - MOST COMMON):** **Mechanism:** - Direct trauma during nerve dissection from fibular neck (nerve adherent to bone - Flandry 1991) - Excessive traction with retractors (nerve ischemia from prolonged retraction greater than 30 minutes) - Drill penetration through fibular head into nerve 2cm distally - Thermal injury from electrocautery near nerve **Prevention:** - Identify nerve FIRST before any fibular head dissection (palpate as cord 2cm distal to apex) - Use BLUNT dissection ONLY to free nerve from fibular neck (NO sharp dissection) - Retract nerve ANTERIORLY with vessel loop (gentle tension, release periodically) - Avoid drilling distal to fibular head (nerve 2cm away) - NO electrocautery within 1cm of nerve (use bipolar if hemostasis needed near nerve) **Recognition:** - **Intraoperative**: If patient under regional anesthesia with incomplete motor block, loss of foot dorsiflexion during case - **Post-operative**: Foot drop, weak ankle eversion, sensory loss dorsum of foot **Immediate Management:** - **Stop surgery** if nerve injury suspected intraoperatively - **Inspect nerve** - assess for laceration vs contusion - **If laceration**: Primary repair with 8-0 or 9-0 nylon microsurgical sutures (requires microscope or loupe magnification) - **If contusion**: Neurolysis (free from hematoma/scar), complete planned reconstruction, document injury - **If thermal injury**: Debride devitalized nerve segment, consider nerve grafting if greater than 1cm defect **Post-Operative Management:** - **AFO (ankle-foot orthosis)** to prevent foot drop and protect from tripping - **Physical therapy** for ankle strengthening and gait training - **Serial EMG** at 6-8 weeks (signs of reinnervation indicate recovery) - **Nerve exploration** if NO recovery by 4-6 months (revision neurolysis vs nerve grafting) - **Tendon transfer** if no recovery by 12 months (tibialis posterior to dorsum of foot - restores dorsiflexion) **Outcome:** - **Neurapraxia** (mild contusion): 90-95% complete recovery by 6-9 months - **Axonotmesis** (moderate crush): 60-70% recovery by 12 months - **Neurotmesis** (complete transection): Requires repair/graft (40-60% functional recovery) **2. POPLITEAL VESSEL INJURY (Less than 1%):** **Mechanism:** - Excessive medial dissection beyond midline of popliteal fossa - Drill penetration through posterior tibia during popliteus tunnel creation (artery lies on posterior tibia) - Sharp dissection in posterior capsule (artery adherent to capsule medially) **Prevention:** - Stay LATERAL to biceps-semimembranosus interval (popliteal vessels lie MEDIAL) - Use fluoroscopy for popliteus tunnel drilling (ensure drill does NOT penetrate posterior cortex) - Blunt dissection in posterior capsule (avoid sharp dissection medially) **Recognition:** - **Pulsatile bleeding** from surgical field (arterial injury) - **Expanding hematoma** in popliteal fossa - **Loss of pedal pulses** (distal ischemia) **Management:** - **Immediate pressure** on bleeding site (compress with gauze) - **Proximal/distal control** with vascular clamps or tourniquets - **URGENT vascular surgery consultation** - DO NOT attempt repair unless trained - **Primary repair** (if less than 1cm defect) or **reverse saphenous vein graft** (if greater than 1cm defect) - **Fasciotomy** if ischemia time greater than 4-6 hours (compartment syndrome risk) **Outcome:** - Primary repair within 6 hours: 85-90% limb salvage - Delayed repair (greater than 6 hours): 70-75% limb salvage, 10-15% amputation rate ### Postoperative Complications **1. GRAFT FAILURE (12% Anatomic PLC, 32% Staged ACL+PLC):** **Risk Factors:** - Non-anatomic reconstruction (single-structure - LCL only) - Staged reconstruction for combined ACL/PCL + PLC injuries (varus/rotatory laxity overloads ACL/PCL graft) - Inadequate graft tensioning (over-tightened or under-tightened) - Early return to pivoting sports (before 9-12 months) - Non-compliance with rehabilitation protocol (early weight-bearing, excessive ROM) **Diagnosis:** - **Recurrent varus laxity**: Greater than 10mm at 30° flexion - **Dial test**: Greater than 10° asymmetry at 30° and/or 90° flexion - **Functional instability**: Varus thrust gait, giving way during pivoting - **MRI**: Graft discontinuity, fluid signal within graft (graft rupture or stretching) **Management:** - **Revision PLC reconstruction**: Remove failed graft, revise tunnels (may need to reposition if non-anatomic), new graft (allograft typically used for revision) - **Address combined instabilities**: If ACL/PCL also loose - revise ALL ligaments simultaneously (NOT staged) - **Longer rehabilitation**: 12 months minimum before return to sport (revision grafts slower to incorporate) **Outcome:** - Revision anatomic PLC reconstruction: 70-75% good outcomes (lower than primary 85-90%) - Multiple revisions (greater than 2): 50-60% good outcomes (diminishing returns with each revision) **2. PERSISTENT ROTATORY INSTABILITY (10-15%):** **Mechanism:** - Non-anatomic reconstruction (LCL only without popliteofibular ligament - incomplete external rotation restraint) - Missed combined ligament injuries (ACL/PCL not reconstructed - overloads PLC reconstruction) - Graft stretching (over time - gradual laxity increase) **Clinical Manifestation:** - **Dial test remains positive**: 10-15° asymmetry at 30° and/or 90° flexion - **Varus laxity normal**: Less than 5mm at 30° flexion (LCL graft intact) - **Functional symptoms**: Difficulty with cutting/pivoting, instability sensation **Management:** - **If LCL-only reconstruction**: Revision with anatomic technique (add popliteofibular ligament reconstruction - LaPrade technique) - **If combined ligament laxity**: Address ACL/PCL laxity (reconstruct deficient ligaments) - **If mild instability** (5-10° dial test asymmetry): Non-operative management with bracing and activity modification (avoid pivoting sports) **Outcome:** - Revision with anatomic technique: 70% improvement in rotatory stability - Non-operative management: 60% able to return to low-demand activities (avoiding pivoting sports) **3. STIFFNESS (5-10%):** **Mechanism:** - Prolonged immobilization (brace locked in extension greater than 2 weeks) - Aggressive early ROM (violates healing popliteus/popliteofibular ligament - tightens in flexion) - Capsular adhesions (arthrofibrosis) - Concomitant procedures (ACL/PCL reconstruction increases stiffness risk) **Clinical Manifestation:** - **Flexion contracture**: Unable to achieve full extension (0°) - most common - **Loss of flexion**: Less than 120° flexion (normal 130-140°) **Prevention:** - Balanced rehabilitation: Gentle ROM 0-90° for first 6 weeks, gradual progression to full ROM by 8-12 weeks - Early mobilization: Remove brace at 2 weeks, start passive ROM (avoid locked brace greater than 2 weeks) - Avoid aggressive stretching in first 6 weeks (protects healing ligaments) **Management:** - **Physical therapy** (first-line): Progressive ROM exercises, joint mobilization, stretching - **Manipulation under anesthesia (MUA)**: If flexion less than 90° at 3 months despite therapy - **Arthroscopic lysis of adhesions**: If MUA fails or arthrofibrosis confirmed on MRI (thick fibrotic tissue in notch/suprapatellar pouch) **Outcome:** - Physical therapy: 70-80% achieve functional ROM (0-120°) within 6 months - MUA: 60-70% achieve functional ROM (additional 20-30° flexion gain) - Lysis of adhesions: 50-60% achieve functional ROM (difficult salvage procedure)

Posterolateral Approach to Knee (Fibular Head)

Posterolateral Approach to Knee (Fibular Head)