Medial Patellotibial Ligament (MPTL) Reconstruction

1. Introduction

2. Anatomy

• Proximal medial patellar restraints: MPFL + MQTFL (medial quadriceps tendon-femoral ligament)
• Distal medial patellar restraints: MPTL + MPML (medial patellomeniscal ligament)

MPTL Specifics

3. Biomechanics

• The MPFL is the primary static restraint to lateral patellar translation (50-60% of restraining force at 0-30° flexion)
• The MPTL contributes approximately 30% of restraint at 30° of knee flexion
• The MPTL has a primary role in controlling patellar tilt and rotation rather than pure lateral shift (Felli et al., Systematic Review, The Surgeon 2021 - PMID 33121878)
• At early flexion (0-30°), before the patella engages the trochlear groove, both MPFL and MPTL are important
• Combined MPFL + MPTL reconstruction restores patellar balance closer to the native state than MPFL reconstruction alone (Hautamaa et al.)

4. Indications for MPTL Reconstruction

• Rare - mainly described in younger patients / skeletally immature where the tibial attachment is preferred over the femoral epiphyseal area
• Recurrent patellar instability with specific MPTL deficiency

• Recurrent patellar dislocation where isolated MPFL reconstruction has failed
• Patellar instability with predominant tilt/rotation deformity
• High-grade patellofemoral instability (especially with trochlear dysplasia, increased TT-TG)
• Skeletally immature patients (avoids distal realignment procedures that risk physeal injury)
• When medial soft-tissue deficiency is global (both MPFL and distal restraints disrupted)
• Patellar instability with patella alta (MPTL acts as a distal tether)

5. Preoperative Planning

• Plain X-rays: AP, lateral (assess patella alta - Caton-Deschamps, Insall-Salvati ratios), axial/Merchant view (patellar tilt, trochlear morphology)
• MRI: Confirm MPFL/MPTL disruption, assess trochlear dysplasia, articular cartilage status
• TT-TG measurement: On CT/MRI - values >20mm may need concomitant tibial tubercle medialization
• Trochlear dysplasia grading (Dejour classification A-D)

6. Surgical Techniques

Technique 1 - Zaffagnini Technique (Medial Patellar Tendon Transfer)

1. Harvest the medial 1/3 of the patellar tendon with a distally attached bone block at the tibial tuberosity
2. The medial patellar tendon fibers are detached proximally from the patella
3. The harvested strip is then sutured to the anteromedial tibia at the anatomic MPTL tibial footprint (5 mm distal to the joint line, 5-6 mm medial to the tibial center)
4. The proximal end is sutured back to the inferomedial patella
5. This effectively recreates the steep inferomedial course of the MPTL
6. Reported outcomes: 29 knees, good clinical and radiographic outcomes, 14% failure rate at mean 6.1-year follow-up (Zaffagnini et al., KSSTA 2014)

Technique 2 - Combined MPFL + MPTL Reconstruction (Hinckel Technique)

• MPFL reconstructed using quadriceps tendon autograft
• MPTL reconstructed using patellar tendon strip (medial 1/3)
• Both grafts share the inferomedial patellar attachment point
• Femoral fixation (for MPFL) with anchor or tunnel at the anatomic point (proximal to medial epicondyle, posterior to adductor tubercle)
• Tibial fixation (for MPTL) with suture anchor or bone tunnel at the medial tibial tubercle

Technique 3 - Hamstrings Tenodesis

• Gracilis or semitendinosus tendon harvested
• Tendon looped around the inferomedial patella and fixed to the anteromedial tibia
• Used when patellar tendon graft is not preferred
• Good outcomes reported in multiple case series

Technique 4 - Direct Repair (Acute Injury)

• In acute first-time dislocations with identifiable bony avulsion or ligament rupture
• Less commonly used; reconstruction preferred for recurrent instability

7. Key Surgical Steps (Generic MPTL Reconstruction)

1. Patient positioning: Supine with leg free or on leg holder; tourniquet applied
2. Diagnostic arthroscopy (if combined): Assess chondral damage, plica, lateral retinaculum
3. Identify patellar footprint: Inferomedial patella, at the junction of the distal 1/3 and medial border - deep to patellar tendon
4. Identify tibial footprint: 5 mm distal to the tibiofemoral joint line and 5-6 mm medial to the tibial center (medial tibial tubercle)
5. Graft preparation: Harvest chosen graft (medial patellar tendon strip, gracilis, or semitendinosus)
6. Patellar fixation: Suture anchors or transosseous tunnels at the inferomedial patella
7. Tibial fixation: Suture anchor or bone tunnel/staple at the medial tibial tubercle
8. Tensioning: Fix graft at 30-60° of knee flexion with the patella reduced centrally in the trochlear groove - avoid over-tensioning (can cause medial instability)
9. Concomitant procedures as needed: tibial tubercle osteotomy for elevated TT-TG, lateral retinacular release for severe tilt

8. Graft Choices (Felli et al., Systematic Review 2021 - PMID 33121878)

9. Postoperative Rehabilitation

• 0-2 weeks: Brace locked in extension, non-weight-bearing or toe-touch weight bearing, quadriceps sets, SLR
• 2-6 weeks: Progressive weight-bearing, range of motion 0-90°
• 6-12 weeks: Full weight-bearing, progressive ROM to full, closed kinetic chain exercises
• 3-6 months: Strengthening, proprioceptive training, sport-specific exercises
• Return to sport: 6-9 months, guided by functional criteria

10. Outcomes

• Good-to-excellent outcomes in >75% of cohorts across most studies
• Redislocation rate <10% with most techniques
• One outlier study reported an 82% failure rate (technique-specific)
• Combined MPFL + MPTL reconstruction shows no significant advantage over isolated MPFL reconstruction in terms of redislocation, but improves patellar tilt control
• Combined MPFL + MPTL reconstruction is favorable for patellofemoral instability with significant medial soft-tissue deficiency (Aicale & Maffulli, Systematic Review, PMID 33183310)

11. Complications

• Over-tightening: Medial patellar instability, reduced knee flexion, chondral damage
• Under-tightening: Persistent lateral instability, failure
• Stiffness: Most common complication
• Graft failure/redislocation: ~5-10%
• Saphenous nerve injury (inferomedial approach)
• Patella fracture (if transosseous tunnels are poorly placed)
• Patellar tendon weakness/tear (if patellar tendon graft harvested)

Summary Box for Exam

MPTL = distal medial patellar restraint; secondary stabilizer; primary role in patellar tilt/rotation control. Reconstruction indicated in recurrent patellar instability (especially combined with MPFL failure, patella alta, pediatric patients). Zaffagnini technique (medial patellar tendon transfer) is the landmark technique. Graft fixed at 30-60° flexion at the medial tibial tubercle (5 mm distal to the joint line). Outcomes: >75% good/excellent, <10% redislocation.

• Campbell's Operative Orthopaedics 15th Ed (2026) - Extraarticular Ligamentous Structures, p. 2618
• Baumann et al. (2018). Systematic Review, KSSTA. [PMID: 29344696]
• Felli et al. (2021). Anatomy and biomechanics systematic review. [PMID: 33121878]
• Aicale & Maffulli (2020). Combined MPFL+MPTL reconstruction systematic review. [PMID: 33183310]
• Zaffagnini et al. (2014). MPTL reconstruction for patellar instability. KSSTA 22:2491-2498.
• Hinckel et al. (2016). Combined MPFL + MPTL reconstruction. Arthrosc Tech 5(1):e79-84.