ARTHROSCOPY ASSISTED MPFL RECONSTRUCTION

DR.SABYASACHI BARDHANDR.S KUMAR

DR.A.K.GARGDR.K.K.MUKHOPADHYAY

MPFL•Most important static restraint •Extrasynovial ligament•Medial femoral epicondyle to medial patellar edge ; 6-7cm,deep to the distal part of vastas medialis obliqus.

MPFL RECONSTRUCTION

• Proximal realignment for patellar instability • Classical indication of isolated MPFL

reconstruction is post traumatic lateral patellar dislocation having no anterior knee pain.

• Anatomical repair ; Open or arthroscopic

CLINICAL PROFILE

• H/O dislocation of patella…single or multiple episodes

• Patellar translation• Patellar tilt test• Apprehension test• Retropatellar tenderness• Knee ROM & patellar tracking• Q angle

IMAGING

• Standard X ray of knee -AP, Lateral & skyline view

• MRI

CHOICE OF PATIENTS

INDICATIONS• Young• Recurrent dislocation• Painless

CONTRAINDICATIONS• Tight lateral structures• Medial instability• Q angle>20 degs/ genu

valgum are relative contraindications for isolated MPFL reconstruction

OVERVIEW OF STEPS

• Examination under anaesthesia • Diagnostic scopy • Graft harvest • Patellar preparation • Femoral condyle preparation • Graft passage and graft isometry check • Fixation under arthroscopic supervision.

EXAMINATION UNDER ANAESTHESIA

• Patellar stability, translation, and tilt are usually easier to characterize when the patient is anesthetized

• If the patient's symptoms and exam are consistent with excessive lateral retinacular tightness, then consideration should be given to performing a concomitant arthroscopic lateral retinacular release.

PATELLAR TRANSLATION

PATELLAR TILT

DIAGNOSTIC ARTHROSCOPY

• Careful assesment of loose bodies

• Articular surfaces , patella and trochlear surface are carefully examined

• Patellar tracking

SURFACE LANDMARKS

GRAFT HARVEST

• Semitendinous graft

• Standard harvesting technique

PATELLAR TUNNEL

•Make two tunnels of 10mm each the first one just where the obliquity of medial border turns to be straight. •The other one 10mm below that •Each tunnel is about 4mm in diameter •Tunnels are made in divergent fashion

PATELLAR TUNNEL

•Vertical drill holes of the same diameter are made 1 cm from the medial patellar margin in a antero post fashion to connect with the horizontal tunnels. •Once tunnel is made Each end of the graft is passed through .

PASSING THE GRAFT

FEMORAL PREPARATION

•Femoral attachment site of the MPFL is in between medial epicondyle and adductor tubercle •Malposition of the femoral tunnel even 5 mm results in increased graft force . •3cms incision over the medial epicondyl. Adductor tubercle identified. A beath pin is drilled across to the opposite cortex

Between the patellar and femoral incision a dialator is passed to make room for the passage of the graft between the layer 2 and 3.

GRAFT ISOMETRY

• To check the behavior of the graft through a range of motion.

• Done by passing a beath pin through the femoral attachment site and wrapping the graft around it observing the length change behavior of the graft between 30-90 range

• Fixed to femur with Intf screw

FINAL TENSIONING OF GRAFT AND FIXATION

• Most important step dictating the surgical outcome

• Prime importance to avoid graft over tightening.

• Arthroscopic visualisation of patellar tracking confirms that patella is fitting properly in the grove without excessive medial pull.

PATELLAR TRACKING

POST OP PROTOCOL

• Static quadriceps after 24 hrs• Dressing change with lighter dressing after

48hrs.• Knee bending, Heel slides to start after 48 hrs; knee brace at all other times, to attain 90 degs

flexion by 2 wks• Partial weight bearing after 48hrs….full weight

bearing by 6 weeks

RESULTS

• No of patients : 6 (4 females, 2 males) • 16y-37y• One of them is professional dancer and one

elite athlete. • The cause of dislocation was post trauma in all

cases. • None of them had preceding anterior knee pain. • Average follow up period was 11 months

RESULTS

ROM: • All patients had 90 deg flexion by 3 weeks. and

no extension lag by 6weeks. • All patients had no pain and full range of

movement by 6 weeks.

RESULTS

• All of them achieved their pre injury activity level and did not have any apprehension or episode of dislocation during the follow up period.

• One patient had a minor skin infection immediate post op which resolved with antibiotics.

CLINICAL PHOTOGRAPHS

CONCLUSION

MPFL reconstruction is a relatively safe technique with very predictable outcome in

carefully selected subset of patients with recurrent patellar lateral instability.

THANK YOU