High Yield Overview

PRIMARY QUADRICEPS TENDON REPAIR

Suture anchor technique | Sports/Knee Surgery

Mnemonic

LAYERS

Mnemonic

KRACKOW

Critical Danger Structures

Suprapatellar Nerve Branches

Infrapatellar branch of saphenous. Location: Crosses anterior knee medially, can be injured with medial retraction. Injury = numb patch anterior knee (common, usually well-tolerated)

Superior Geniculate Vessels

Arterial branches within tendon. Location: 2-4cm proximal to patellar insertion, within tendon substance. Careful dissection, bipolar cautery. Bleeding obscures field

Femoral Trochlear Cartilage

Articular surface deep to tendon. Location: Visible when knee flexed. Risk with anchor placement too posterior or trans-osseous tunnel exit. Anchor 5mm from articular margin

VMO Insertion (Medial Patella)

Critical for patellar tracking. Location: Medial patella border, oblique fibers. Must repair VMO insertion - failure causes lateral tracking and recurrent instability

Absolute Indications

Complete quadriceps tendon rupture (inability to SLR or extend knee against gravity)
Partial rupture greater than 50% thickness with weak extension
Failed non-operative management of partial rupture
Bony avulsion of quadriceps tendon insertion

Relative Indications

Partial rupture less than 50% with intact SLR (trial conservative first)
High-demand patient with partial tear wanting rapid return
Chronic rupture greater than 6 weeks (may need augmentation)

Timing

Acute repair (less than 2-3 weeks) preferred - better tissue quality, easier repair
Acute repair (less than 6 weeks) still achievable with standard technique
Chronic repair (greater than 6 weeks) - expect retraction, scarring, may need augmentation or V-Y lengthening

Equipment

Positioning

Standard operating table
Bump under ipsilateral hip (neutral rotation)
Knee must flex freely to 90 degrees - test before draping
Sandbags available to maintain knee position during suturing
Thigh tourniquet

Implants

Suture anchors: 3-4 anchors, 5.5mm or 6.5mm diameter
Each anchor loaded with 2 heavy sutures (#2 or #5 FiberWire/Ethibond)
Alternative: knotless anchors (SwiveLock, PushLock) - stronger fixation
Consider suture tape for augmentation in high-risk cases

Instruments

Basic soft tissue set
Army-Navy or Langenbeck retractors
Allis clamps (for tendon traction)
Heavy needle drivers (for thick sutures)
Curved Mayo or Keith needles
Anchor insertion guide and drill
Bipolar cautery

Supplies

Sterile tourniquet (thigh - 250-300mmHg)
Heavy braided suture (#2 Ethibond or #2 FiberWire)
2-0 Vicryl for retinacular repair
Drain (10Fr Hemovac) - optional
Hinged knee brace or cylinder cast materials

Positioning and Preparation

Patient Position: Supine with bump under ipsilateral hip for neutral leg rotation. Tourniquet on upper thigh (inflate to 250-300mmHg). Ensure knee can flex freely to at least 90 degrees - test before draping as this is essential for repair tensioning.

Anaesthesia: General or spinal. Femoral nerve block provides good postoperative analgesia but delays quadriceps assessment.

Surgical Approach: Anterior midline longitudinal approach over quadriceps tendon and superior patella

Surface Landmarks:

Superior pole of patella
Quadriceps tendon (normally taut, will have palpable gap)
VMO bulge (medially)
Proximal extent of rupture (retracted tendon edge)

Operative Technique

Step 1: Incision and Exposure

Midline longitudinal incision from 6-8cm proximal to superior pole of patella, extending to mid-patella (total 10-12cm). Incise through skin and subcutaneous tissue. Identify the rupture site - usually obvious with visible gap and hematoma. May need to extend proximally for chronic tears with retracted tendon.

Key Anatomy: Most ruptures occur 1-2cm proximal to patellar insertion (watershed zone of hypovascularity). 30% are bony avulsions at insertion. Ruptures typically initiate medially at VMO insertion (weakest point) and propagate laterally.

Exam Pearl

EXAM KEY: Midline incision gives best exposure and minimizes nerve injury. For chronic ruptures (greater than 6 weeks), extend proximally to mobilize retracted quadriceps. Identify torn retinacular edges which guide you to the injury.

Dangers at this step

Inadequate exposure hampers visualization of full tear extent
Incision too far medial risks saphenous nerve branches
Missing partial tears medially or laterally leads to incomplete repair

Step 2: Hematoma Evacuation and Injury Assessment

Evacuate hematoma with suction and copious irrigation. Systematically assess rupture pattern:

Complete vs partial: test each layer independently
Location: intrasubstance (1-2cm above patella) vs bony avulsion
Chronicity: acute (healthy tissue) vs chronic (degenerate, retracted)
Layer involvement: rectus (superficial), VMO/VL (intermediate), VI (deep)

Gently retract patella distally with Langenbeck retractor to visualize proximal tendon edge.

Exam Pearl

EXAM KEY: Complete rupture = discontinuity of ALL three quadriceps layers. Assess EACH LAYER independently. Partial tears often have intact intermediate layer (VMO/VL) maintaining some continuity and ability to SLR weakly. Chronic tears (greater than 6 weeks) have retraction, scarring, tissue degeneration - these need different approach.

Dangers at this step

Missing partial tear laterally (most tears begin medially and propagate)
Underestimating chronic changes (gap may be greater than expected)
Failure to assess tendon quality - degenerative tissue won't hold sutures

Step 3: Proximal Tendon Preparation

Identify proximal tendon stump - may be retracted significantly in chronic tears. Use Allis clamps to grasp tendon for traction. Debride frayed degenerative edges minimally (1-2mm) to create perpendicular edge, but preserve tendon length. Assess tendon excursion by pulling distally with knee at 30-40 degrees.

Tendon Quality Assessment: Healthy tendon is white/pink, glistening, firm. Degenerative tendon is grey, friable, won't hold sutures (needs aggressive debridement or augmentation). Mark tendon layers with marking sutures to maintain orientation.

Exam Pearl

EXAM KEY: Tendon QUALITY is critical predictor of success. Grey, friable tissue won't hold sutures - needs aggressive debridement or augmentation. For acute tears, minimal debridement. Test excursion by pulling tendon distally with knee at 30-40 degrees flexion - if excessive tension (can't approximate without force), may need proximal release or augmentation.

Dangers at this step

Excessive debridement reduces tendon length and increases repair tension
Inadequate debridement leaves degenerative tissue (repair failure)
Loss of layer orientation causes malrotation during repair

Step 4: Patellar Bone Bed Preparation

Use rongeur or curette to remove fibrous tissue and create bleeding bone surface on superior pole of patella (insertion site). Create flat 1-1.5cm width footprint from anterior to posterior cortex. Expose cortical bone but don't penetrate or weaken patella excessively.

Technical Goals: Optimize biology for tendon-to-bone healing. Debride to 'bleeding bone' - punctate bleeding indicates healthy cortex. Mark proposed anchor positions before drilling.

Exam Pearl

EXAM KEY: Goal is optimal tendon-to-bone healing environment. Remove ALL cartilage and fibrous tissue (impedes healing). Roughening with burr increases surface area. Avoid excessive bone removal (weakens patella, fracture risk). Create rectangular footprint matching tendon width.

Dangers at this step

Excessive bone removal weakens patella (fracture risk especially with osteoporosis)
Inadequate debridement (fibrous tissue) impairs healing
Violating articular surface posteriorly with aggressive preparation

Step 5: Suture Anchor Placement

Insert 3-4 suture anchors (5.5mm or 6.5mm) into superior pole of patella:

Position anchors in CORONAL plane, 5mm from articular surface
Space anchors 7-10mm apart transversely
Use anchor insertion guide, drill pilot hole
Insert anchor PERPENDICULAR to bone surface
Each anchor loaded with two heavy sutures (#2 or #5)
Confirm secure fixation - no articular penetration

Anchor Selection: Knotless anchors (SwiveLock, PushLock) provide stronger fixation. Three anchors minimum for standard tear, four for large/chronic tears.

Exam Pearl

EXAM KEY: Suture anchors are modern GOLD STANDARD - faster, biomechanically equivalent to trans-osseous tunnels, LESS patellar fracture risk (less than 2% vs 5-10% with tunnels). Position anchors 5mm from articular surface. Use knotless anchors if available - eliminates knot prominence and provides stronger fixation.

Dangers at this step

Anchor too posterior: articular penetration, chondral damage
Anchor too anterior: pullout from thin cortex
Anchor divergence: loss of fixation strength
Over-drilling/tapping pilot hole: anchor spins without purchase

Step 6: Krackow Suture Placement in Tendon

Pass anchor sutures through proximal tendon using locked KRACKOW technique:

Start at tendon edge
Pass from anterior to posterior
Lock by passing under previous throw
Repeat for 4-6 bites, extending 3-4cm from tendon edge
Each suture should engage ALL three layers (superficial, intermediate, deep)
Use curved Mayo or Keith needles

Alternative: Mason-Allen horizontal mattress pattern with locking loop.

Exam Pearl

EXAM KEY: Krackow (locked whipstitch) provides STRONGEST fixation - 4-6 points of fixation per suture with locking mechanism preventing pullout. Failure load approximately 300N. CRITICAL: engage ALL THREE layers, not just superficial rectus. Use heavy sutures (#2 minimum, #5 ideal).

Dangers at this step

Superficial sutures only (rectus layer): intermediate/deep layer failure
Too few bites (less than 4): inadequate fixation strength
Sutures too close to tendon edge: cheese-wiring and pullout
Unequal suture tension: eccentric force, tendon distortion

Step 7: Repair Tensioning and Knot Tying

CRITICAL: Position knee at 30-40 degrees flexion for tying.

Pull sutures to advance tendon to patellar insertion site. Tie knots sequentially:

Central sutures first (establishes proper tension)
Medial sutures
Lateral sutures

Use surgeon's knots (2-1-1 pattern) with 6-8 throws. Tension so tendon is snugly opposed to bone without excessive compression (allows 1-2mm tendon compression).

Exam Pearl

EXAM KEY: Repair TENSION is the critical decision. Tie at 30-40 degrees flexion (position of maximum extensor force). If tied at 0 degrees, repair too loose at functional flexion. If tied at 90 degrees, too tight at extension. Goal: tendon snugly opposed throughout 0-90 degrees ROM. Test by passively flexing to 90 degrees after tying - should maintain approximation without gapping greater than 3mm.

Dangers at this step

Over-tightening: tendon necrosis, paradoxical gap formation
Under-tightening: gap at flexion, repair failure
Tying with knee extended: repair too loose at functional ROM
Unequal tension: eccentric forces cause lateral patellar tracking

Step 8: Retinacular Repair

Repair torn medial and lateral retinaculum with 2-0 braided absorbable suture (Vicryl) in interrupted figure-of-8 or simple pattern. Start at patellar insertion and work proximally. Ensure VMO insertion is secure.

Technique for Chronic Tears: May need to mobilize adhesions and advance retinacular tissue. Consider imbrication (vest-over-pants overlap) for additional strength.

Exam Pearl

EXAM KEY: Retinacular repair provides 30-40% additional strength to construct - ESSENTIAL, not optional. Most ruptures propagate through retinaculum. Repair BOTH medial and lateral sides. VMO insertion must be secure (critical for patellar tracking). For chronic tears with retraction, advance and imbricate tissue.

Dangers at this step

Inadequate retinacular repair: construct weakness, increased failure risk
Over-tight retinacular repair: limits ROM, causes patellar tilt
Missing lateral retinacular tear (tears propagate medial-to-lateral)

Step 9: Augmentation (High-Risk Patients)

For high-risk patients consider augmentation:

Suture tape (InternalBrace, FiberTape): load anchor with repair sutures AND tape, pass tape superficial to repair, anchor distally - increases failure load 40-60%
Autograft (semitendinosus): weave through repair
Allograft (Achilles or fascia lata): overlay

Indications for Augmentation: Chronic rupture greater than 6 weeks, revision repair, poor tissue quality, high-risk patients (diabetes, CKD, steroids).

Exam Pearl

EXAM KEY: Augmentation indicated for: (1) Chronic rupture greater than 6 weeks with tissue degeneration, (2) Revision after failed primary, (3) High-risk patients, (4) Poor tissue quality intraoperatively, (5) Repair under high tension. Suture tape technique increases failure load by 40-60% in biomechanical studies.

Dangers at this step

Over-reliance on augmentation to compensate for poor primary repair technique
Suture tape irritation if placed too superficially (may need removal)
Allograft: disease transmission risk (rare), delayed incorporation

Step 10: Intraoperative Stability Assessment

Release tourniquet. Test repair:

Full extension: ensure no extensor lag (passively extend knee fully without lifting thigh)
Flexion test: GENTLY flex knee passively to 90 degrees
- Repair should remain intact without gapping
- Feel for loss of resistance (indicates failure)
- If gaps greater than 3mm at 90 degrees - repair too loose, re-tension

Document maximum safe flexion angle achieved for postoperative physiotherapy.

Exam Pearl

EXAM KEY: This is the PROOF of adequate repair. Under anaesthesia: passively extend knee fully (tests for lag). Then flex smoothly to 90 degrees - should feel firm resistance throughout arc. Sudden loss of resistance or visible gapping = repair failure requiring revision. Document safe flexion range for PT protocol.

Dangers at this step

Forced flexion beyond repair capacity causes intraoperative failure
Missing subtle gapping (becomes extensor lag postoperatively)
Testing beyond 90 degrees in borderline repairs: unnecessary risk

Step 11: Closure and Hemostasis

Achieve meticulous hemostasis with bipolar cautery. Close paratenon with 3-0 absorbable suture (provides smooth gliding surface). Consider 10Fr drain if concern for hematoma. Close subcutaneous layer with 2-0 absorbable suture. Skin closure with staples or 3-0 nylon.

Exam Pearl

EXAM KEY: Paratenon closure often forgotten but improves gliding and cosmesis. Drain optional but helpful for 24 hours to prevent hematoma (increases infection risk and adhesions). Meticulous hemostasis essential - inflate/deflate tourniquet to identify bleeders before closure.

Dangers at this step

Hematoma: increased infection risk (2-5%), adhesions, stiffness
Tight closure: skin necrosis, wound breakdown
Drain placed anteriorly: erosion through thin skin

Step 12: Immobilization

Apply sterile dressing. Place knee in hinged brace or cylinder cast LOCKED in FULL EXTENSION (0 degrees). This is MANDATORY.

Postoperative Protocol:

Brace locked at 0 degrees for 4 weeks
Non-weight bearing with crutches
Isometric quadriceps sets from day 1-2
Weeks 4-6: unlock to 30 degrees for supervised PT, re-lock for ambulation
Weeks 6-8: progress to 60 degrees
Weeks 8-12: progress to 90 degrees, start partial weight bearing
Active flexion after 12 weeks
Full ROM by 16-20 weeks
Return to sport: 6-9 months minimum

Exam Pearl

EXAM KEY: Extension immobilization is MANDATORY - prevents load on repair during early healing. Options: hinged brace (preferred - allows wound checks) or cylinder cast (more secure). Continue locked extension for 4-6 weeks, then progressive ROM. NWB minimum 6 weeks. Expect 6-12 months for full recovery.

Dangers at this step

No immobilization: repair failure (nearly certain)
Flexion immobilization: permanent flexion contracture
Over-tight dressing: compartment syndrome risk
Early unrestricted ROM: repair failure (10-20%)

Complications

Complications: Recognition, Prevention, and Management

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

EXAMINER

"A 62-year-old diabetic man stumbles on a step and presents with knee swelling and inability to walk. He cannot straight leg raise. Describe your assessment and management."

EXCEPTIONAL ANSWER

This presentation is highly suspicious for complete quadriceps tendon rupture - a surgical emergency in terms of functional outcome. **History**: Mechanism (eccentric quadriceps load with stumble), heard/felt 'pop', immediate instability, unable to bear weight. Risk factors present: age greater than 50 years, diabetes (5x increased rupture risk). Ask about steroid use, kidney disease, gout, previous tendon problems, quinolone antibiotics. **Examination**: - Inspection: suprapatellar swelling/ecchymosis, may see/palpate suprapatellar gap (can be masked by hematoma) - Key tests: Inability to straight leg raise (PATHOGNOMONIC of complete rupture), inability to extend knee against gravity from flexed position - Compare to contralateral side (5-10% bilateral ruptures) - Neurovascular assessment **Imaging**: - X-ray: lateral view shows PATELLA BAJA (Insall-Salvati ratio less than 0.8), look for bony avulsion fragment - MRI: confirms diagnosis, shows extent of tear, assesses tissue quality **Management**: This is a complete rupture requiring surgical repair. I would: 1. **Optimize medically**: check HbA1c, optimize glucose control 2. **Consent**: discuss 10-20% re-rupture risk (higher in diabetics), 15-30% mild extensor lag, 6-12 month recovery, need for strict bracing compliance 3. **Surgical repair**: suture anchor technique with Krackow sutures through tendon engaging all three layers, retinacular repair, consider augmentation given diabetes 4. **Postoperative**: locked extension brace 4-6 weeks, protected rehabilitation protocol **Key Point**: Delay worsens outcomes - acute repair (less than 2 weeks) has best tissue quality and outcomes.

VIVA SCENARIOStandard

EXAMINER

"Describe the anatomy of the quadriceps tendon and explain how this relates to repair technique."

EXCEPTIONAL ANSWER

The quadriceps tendon has a complex THREE-LAYER structure that is critical to understand for successful repair. **Layer Anatomy** (superficial to deep): 1. **Superficial Layer - Rectus Femoris**: - Two heads: straight head (AIIS) and reflected head (superior acetabulum) - Only quadriceps muscle crossing hip AND knee - Forms most superficial portion of tendon - Longest fibers - most prone to retraction 2. **Intermediate Layer - Vastus Medialis and Lateralis**: - VMO: fibers run 55 degrees oblique (critical for patellar tracking) - VL: fibers run 30 degrees oblique - Converge 2-3cm above patella - VMO insertion is WEAKEST POINT - ruptures typically start here 3. **Deep Layer - Vastus Intermedius**: - Lies directly on femur - Shortest fibers - Forms deepest portion of tendon - Often has best tissue quality **Rupture Characteristics**: - Location: Most occur 1-2cm proximal to patellar insertion (watershed zone of hypovascularity) - Initiation: Usually starts MEDIALLY at VMO (weakest point) and propagates laterally - 30% are bony avulsions at patellar insertion **Surgical Implications**: 1. **Must repair ALL three layers** - superficial-only repair (rectus) will fail when intermediate/deep layers pull through 2. **Krackow sutures must engage all layers** - pass needle from anterior to posterior through full tendon thickness 3. **VMO repair critical** - must restore oblique VMO insertion for proper patellar tracking; failure causes lateral maltracking 4. **Layer orientation** - mark layers with sutures to prevent malrotation during repair 5. **Tension assessment** - all layers must be approximated equally; unequal tension causes eccentric forces

VIVA SCENARIOStandard

EXAMINER

"Compare suture anchor fixation versus trans-osseous tunnel technique for quadriceps tendon repair. What are the advantages and disadvantages of each?"

EXCEPTIONAL ANSWER

Both techniques achieve equivalent functional outcomes, but suture anchors have become the modern gold standard due to several advantages. **Suture Anchor Technique**: *Advantages*: - **Lower patellar fracture risk**: less than 2% vs 5-10% with tunnels - **Faster operative time**: no tunnel drilling, simpler passage - **Less bone removal**: preserves patellar integrity - **Knotless options available**: SwiveLock/PushLock provide stronger fixation, no knot prominence - **Biomechanically equivalent**: similar pullout strength (approximately 300N) - **Easy revision**: can add more anchors if needed *Disadvantages*: - **Cost**: anchors more expensive than suture alone - **Anchor pullout**: risk in osteoporotic bone - **Articular penetration**: if placed too posteriorly - **Learning curve**: proper positioning critical **Trans-Osseous Tunnel Technique**: *Advantages*: - **Lower cost**: only suture required - **Familiar technique**: traditional, well-established - **No implant**: useful if infection concern - **Reliable fixation**: suture tied over bone bridge *Disadvantages*: - **Higher patellar fracture risk**: 5-10% (main concern) - **Longer operative time**: drilling tunnels time-consuming - **Stress risers**: tunnels create weak points - **Articular risk**: posterior tunnel exit can damage cartilage - **Knot prominence**: sutures tied anteriorly may irritate **Clinical Decision Making**: - **Standard cases**: Suture anchors preferred (lower fracture risk) - **Osteoporotic bone**: Consider tunnels (anchor pullout risk) or augmentation - **Revision surgery**: May combine both techniques - **High-risk patients** (diabetes, CKD): Consider augmentation with either technique **Technical Pearls**: - If using anchors: 3-4 anchors, 5mm from articular surface, each with 2 heavy sutures - If using tunnels: 3 pairs (6 total), space greater than 7mm apart, avoid thin patella

Quadriceps Tendon Repair - Exam Summary

High-Yield Exam Summary

References

Ciriello V, Gudipati S, Tosounidis T, et al. Clinical outcomes after repair of quadriceps tendon rupture: a systematic review. Injury. 2012;43(11):1931-1938.
Saragaglia D, Pison A, Rubens-Duval B. Acute and old ruptures of the extensor apparatus of the knee in adults (excluding knee replacement). Orthop Traumatol Surg Res. 2013;99(1 Suppl):S67-76.
Konrath GA, Chen D, Lock T, et al. Outcomes following repair of quadriceps tendon ruptures. J Orthop Trauma. 1998;12(4):273-279.
Ramseier LE, Werner CM, Heinzelmann M. Quadriceps and patellar tendon rupture. Injury. 2006;37(6):516-519.
Lighthart WA, Cohen DA, Levine RG, Parks BG, Boucher HR. Suture anchor versus suture through tunnel fixation for quadriceps tendon rupture: a biomechanical study. Orthopedics. 2008;31(5):441.
Hart ND, Wallace MK, Scovell JF, Krupp RJ, Cook C, Wyland DJ. Quadriceps tendon rupture: a biomechanical comparison of transosseous equivalent double-row suture anchor versus transosseous tunnel repair. J Knee Surg. 2012;25(4):335-339.
Boudissa M, Roudet A, Rubens-Duval B, Chaussard C, Saragaglia D. Acute quadriceps tendon ruptures: a series of 50 knees with an average follow-up of more than 6 years. Orthop Traumatol Surg Res. 2014;100(2):213-216.
Ilan DI, Tejwani N, Keschner M, Leibman M. Quadriceps tendon rupture. J Am Acad Orthop Surg. 2003;11(3):192-200.
Swamy GN, Nanjayan SK, Yallappa S, Bishnoi A, Pickering SA. Is ultrasound diagnosis reliable in acute extensor tendon injuries of the knee? Acta Orthop Belg. 2012;78(6):764-770.
Yepes H, Tang M, Morris SF, Stanish WD. Relationship between hypovascular zones and patterns of ruptures of the quadriceps tendon. J Bone Joint Surg Am. 2008;90(10):2135-2141.

Primary Quadriceps Tendon Repair with Suture Anchor Technique