MPFL Reconstruction for Patellar Instability

Dr SHEKHAR SRIVASTAV Sr.Consultant- Arthroscopy

(Knee & Shoulder) Sant Parmanand Hospital,Delhi

Patellar Instability Incidence Primary Patellar Dislocation- 5.8 / 10000 Recurrence rate – 15 – 44% > 100 surgeries-

-Lateral retinacular release, -Proximal realignment, -Distal realignment, -Trochleoplasty -Combinations

Patellar Stability

Three Imp. Factors -Articular Geometry -Muscle action -Passive soft tissue restrain

Anatomic studies- MPFL contributes 60% of medial restraining force (Desio et al AJSM 1998,conlan et al JBJS1993)

MPFL torn in 94% patients with acute patellar dislocation (Sallay et al AJSM 1996)

Case 1 15 yr old girl Recurrent Instability following trauma Apprehension test- +ve

Surgical Technique - Diagnostic Arthroscopy - Look for any Osteochondral fragment (Loose body) - Look for any Chondral damage - Patellar tracking though Supero-lateral portal

Graft Harvest

Gracilis/ Semi-T Graft – Harvest

Patella Fixation Junction of Upper 1/3rd and lower 2/3rd Should be at the centre- not violating ant. Cortex or articular surface. Tunnel diameter- Minimal to avoid Patellar fracture

Patella fixation

Patella Fixation

Graft fixed in Patella with Anchors

Femoral Tunnels

Schottle’s Insertion Point- 2.5 mm distal to Posterior cortical line intersecting with perpendicular drawn from posterior articular surface of femoral condyle

Femoral Tunnels

Leg

Thigh

Medial

Lateral Wire directed anteriorly and Proximally

Femoral Tunnel

Graft Passage

Graft passed to the medial wound through Tunnel Sub-muscular but Extra Synovial

Graft Passage

Graft Fixation

Fixed in the femoral tunnel at an angle of 30-450 degree and patella centered in trochlear groove Avoid overtightening

Radiographs

Clinical Pictures

Post-op Protocol Ambulation with stick and Knee Brace- 3 wks ROM exer – Next day upto 300 and progress Review every 2 wks,6 wks,3 mnths,6 mnths and yearly thereafter Post-op assessment (Crosby-Insall criteria)

Excellent- No pain,normal activity Good- Occasional pain,discomfort Fair/Poor- Pain,loss of flexion,recurrent

dislocation/subluxation Worse- Pain increased,displacement more

frequent

Caution

Must avoid overtightening- Medial instability Medial patellar arthritis

Patellar fractures Preexisting Chondromalacia

THANK YOU

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