**Posterior Cruciate Ligament (PCL) Avulsion Fracture Fixation: A Comprehensive Review of Arthroscopic vs. Open Surgical Approaches**
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### **Abstract**
Posterior cruciate ligament (PCL) avulsion fractures, though less common than anterior cruciate ligament (ACL) injuries, represent a significant subset of knee trauma that demands precise diagnosis and timely intervention. These fractures typically occur at the tibial insertion of the PCL and are most prevalent in high-energy trauma or sports-related hyperflexion injuries. Management strategies range from non-operative treatment for minimally displaced fractures to surgical fixation for displaced (>2–3 mm) or unstable injuries. In recent decades, surgical techniques have evolved from traditional open posterior approaches to minimally invasive arthroscopic methods. This review synthesizes current evidence on **arthroscopic versus open fixation** of PCL avulsion fractures, focusing on surgical indications, biomechanical principles, clinical outcomes, complication profiles, and rehabilitation protocols. Emphasis is placed to enhance clinical discoverability and guide evidence-based decision-making for orthopedic surgeons, sports medicine specialists, and trauma teams.
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### **1. Introduction**
The posterior cruciate ligament (PCL) is the primary stabilizer of the knee against posterior tibial translation and plays a critical role in rotational and varus-valgus stability. PCL injuries account for approximately 3% of all knee ligament injuries, with **avulsion fractures at the tibial footprint** representing 20–30% of PCL lesions—particularly in skeletally immature patients and young adults.
Unlike mid-substance PCL tears, which may be managed conservatively, **PCL avulsion fractures often require surgical fixation** when displaced, as nonunion or malunion can lead to chronic posterior instability, gait abnormalities, and early osteoarthritis. The choice between **arthroscopic** and **open surgical fixation** remains a topic of active debate, influenced by surgeon experience, fracture morphology, soft-tissue envelope, and institutional resources.
This article provides a detailed, evidence-based comparison of both techniques, optimized for clinical search intent and designed to answer frequently asked questions from practitioners and patients alike.
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### **2. Anatomy and Biomechanics of the PCL**
The PCL originates from the **medial femoral condyle** and inserts onto the **posterior aspect of the tibial plateau**, just below the articular surface. It consists of two functional bundles:
- **Anterolateral bundle (ALB)**: Tight in flexion
- **Posteromedial bundle (PMB)**: Tight in extension
The tibial insertion is broad and robust, making it susceptible to **bony avulsion** rather than ligamentous rupture in younger patients with strong ligaments and open physes.
Biomechanically, the PCL resists:
- Posterior tibial translation (primary)
- External rotation
- Varus stress
Loss of PCL integrity increases posterior drawer by 8–12 mm and alters knee kinematics, accelerating cartilage wear.
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### **3. Classification of PCL Avulsion Fractures**
The most widely used system is the **Meyers and McKeever classification** (modified by Moore):
- **Type I**: Minimally displaced (<2–3 mm); intact periosteal hinge
- **Type II**: Hinged fragment displaced anteriorly with posterior cortex intact
- **Type III**: Completely displaced fragment (>5 mm)
- **Type IV**: Comminuted or bilateral (rare)
**Surgical indication**: Type II (if unstable), Type III, and Type IV fractures.
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### **4. Indications for Surgical Fixation**
Surgery is recommended when:
- Displacement >2–3 mm on lateral radiograph or CT
- Positive posterior drawer test under anesthesia
- Associated ligamentous or meniscal injuries
- Failure of 2–3 weeks of conservative management in Type II fractures
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### **5. Open Fixation: Techniques and Outcomes**
#### **5.1. Surgical Approaches**
- **Posterior midline incision**: Provides wide exposure but risks neurovascular injury (tibial nerve, popliteal artery).
- **Posterior S-shaped or inverted L-approach**: Better visualization of the posteromedial and posterolateral corners.
- **Direct posterior arthrotomy**: Allows direct reduction and fixation.
#### **5.2. Fixation Methods**
- **Cannulated screws** (most common): 3.5–4.0 mm, often with washers
- **Tension band wiring**: For small or comminuted fragments
- **Suture anchors**: In pediatric or osteoporotic bone
#### **5.3. Advantages**
- Direct visualization of fracture
- Precise anatomical reduction
- High initial fixation strength
#### **5.4. Disadvantages**
- Risk of **popliteal neurovascular injury** (reported in 2–8% of cases)
- **Wound complications**: Infection, dehiscence, seroma
- **Postoperative stiffness** due to extensive dissection
- Longer hospital stay and rehabilitation
#### **5.5. Clinical Outcomes**
- Union rates: 90–98%
- Lysholm scores: 85–92 at 2 years
- Residual posterior laxity in 15–20% of cases
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### **6. Arthroscopic Fixation: Techniques and Outcomes**
#### **6.1. Patient Positioning and Portal Placement**
- **Supine position** with leg holder or **prone position** (preferred by many for better access)
- Standard anterolateral (AL) and anteromedial (AM) portals
- Optional **posteromedial (PM)** and **posterolateral (PL)** portals for fragment manipulation
#### **6.2. Reduction Techniques**
- **Suture cerclage**: Using FiberWire or high-strength sutures passed through bone tunnels
- **Screw fixation under arthroscopic guidance**: Using cannulated screws inserted percutaneously
- **Pullout suture technique**: Sutures passed through the fragment and tied over a button or washer on the anterior tibia
#### **6.3. Advantages**
- Minimally invasive
- Lower risk of neurovascular injury
- Reduced postoperative pain and swelling
- Earlier mobilization
- Better cosmetic outcome
#### **6.4. Disadvantages**
- Steep learning curve
- Limited visualization in obese or muscular patients
- Risk of **non-anatomic reduction** if fragment is not adequately visualized
- Potential for hardware irritation if washers are prominent
#### **6.5. Clinical Outcomes**
- Union rates: 88–95%
- IKDC scores: 88–94
- Return to sport: 5–6 months (vs. 7–9 months for open)
- Complication rate: <5% (mainly transient numbness or stiffness)
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### **7. Comparative Evidence: Arthroscopic vs. Open**
| **Parameter** | **Arthroscopic Fixation** | **Open Fixation** |
|--------------|----------------------------|-------------------|
| Operative time | 60–90 min | 90–120 min |
| Blood loss | Minimal | Moderate |
| Hospital stay | Outpatient or 1 day | 2–3 days |
| Union rate | 88–95% | 90–98% |
| Infection rate | <1% | 2–5% |
| Neurovascular injury | Rare | 2–8% |
| Posterior stability (stress radiographs) | Excellent | Excellent |
| Return to work | 6–8 weeks | 10–12 weeks |
| Patient satisfaction | High | Moderate to high |
**Meta-analysis Insight**: A 2023 systematic review (Zhang et al.) of 12 studies (n=342 patients) found **no significant difference in union rates or functional outcomes**, but **arthroscopic fixation had significantly lower complication rates** (OR 0.32, p<0.01).
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### **8. Special Considerations**
#### **8.1. Pediatric Patients**
- Open physes require careful technique to avoid growth disturbance
- Suture-based fixation preferred over screws
#### **8.2. Osteoporotic Bone**
- Use washers or suture anchors to prevent pullout
- Consider bone grafting for comminuted fractures
#### **8.3. Combined Injuries**
- PCL avulsion + ACL tear: Fix PCL first, then ACL reconstruction
- PCL + PLC injury: May require staged or combined approach
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### **9. Rehabilitation Protocol**
**Phase 1 (0–2 weeks)**:
- Knee immobilizer in extension
- Toe-touch weight-bearing
- Quad sets, heel slides
**Phase 2 (2–6 weeks)**:
- Hinged brace (0–90°)
- Progressive weight-bearing
- ROM exercises
**Phase 3 (6–12 weeks)**:
- Full weight-bearing
- Strengthening (hamstrings, quads)
- Stationary bike
**Phase 4 (3–6 months)**:
- Sport-specific drills
- Plyometrics
- Return to play clearance
> ⚠️ **Caution**: Avoid active hamstring contraction before 8 weeks to prevent posterior tibial translation.
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### **10. Complications**
| **Complication** | **Arthroscopic** | **Open** |
|------------------|------------------|--------|
| Nonunion | 2–5% | 2–4% |
| Infection | <1% | 2–5% |
| Stiffness | 5% | 10–15% |
| Neuropraxia | Rare | 2–8% |
| Hardware irritation | 3% | 5% |
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### **11. Future Directions**
- **Navigation-assisted arthroscopy** for precise screw placement
- **Biodegradable implants** to avoid hardware removal
- **3D-printed patient-specific guides** for complex fractures
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### **12. Conclusion**
Both **arthroscopic and open fixation** of PCL avulsion fractures yield excellent union and functional outcomes when performed by experienced surgeons. However, **arthroscopic fixation offers superior safety, faster recovery, and lower morbidity**, making it the preferred approach in most cases—especially for Type II and III fractures in young, active patients. Open fixation remains valuable for **severely comminuted (Type IV) fractures** or when arthroscopic expertise is unavailable. Shared decision-making, based on fracture pattern, patient factors, and surgeon skill, is key to optimal outcomes.
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### **Frequently Asked Questions (FAQs)**
**Q1: What is a PCL avulsion fracture?**
A: A bony fragment pulled off the back of the tibia where the posterior cruciate ligament attaches, usually due to a fall or sports injury.
**Q2: Do all PCL avulsion fractures need surgery?**
A: No—only if displaced >2–3 mm or unstable. Non-displaced fractures heal well with bracing.
**Q3: Is arthroscopic fixation better than open surgery?**
A: For most cases, yes—it’s less invasive, safer, and allows faster recovery with similar healing rates.
**Q4: How long does recovery take after PCL avulsion surgery?**
A: Full recovery takes 6–9 months. Most patients walk without crutches by 6–8 weeks.
**Q5: Can you walk with a PCL avulsion fracture?**
A: With a brace and crutches, yes—but weight-bearing depends on displacement and surgical fixation.
**Q6: What happens if a PCL avulsion is not treated?**
A: Chronic knee instability, pain, early arthritis, and difficulty with stairs or running.
**Q7: Is physical therapy necessary after surgery?**
A: Absolutely—rehab is critical to restore strength, motion, and stability.
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### **References**
1. **Moore, T. M.** (1982). *Posterior cruciate ligament avulsion fractures*. Clin Orthop Relat Res, (167), 133–136.
2. **Meyers, M. H., & McKeever, F. M.** (1959). *Fracture of the intercondylar eminence of the tibia*. J Bone Joint Surg Am, 41(8), 1437–1442.
3. **Zhang, Y., et al.** (2023). *Arthroscopic vs. open fixation for PCL avulsion fractures: A systematic review and meta-analysis*. Arthroscopy, 39(4), 1125–1134. https://doi.org/10.1016/j.arthro.2022.10.012
4. **Kumar, D., et al.** (2021). *Arthroscopic pullout suture fixation of PCL avulsion fractures: Mid-term outcomes*. Knee Surg Sports Traumatol Arthrosc, 29(8), 2678–2685.
5. **Sharma, H., et al.** (2020). *Open posterior approach for PCL avulsion: Complications and outcomes*. J Orthop Trauma, 34(5), e162–e167.
6. **LaPrade, R. F., et al.** (2019). *Anatomy and biomechanics of the posterior cruciate ligament*. Sports Health, 11(2), 131–139.
7. **Gwinner, C., et al.** (2018). *Arthroscopic fixation of tibial PCL avulsion fractures using suture anchors*. Arch Orthop Trauma Surg, 138(6), 827–833.
8. **American Academy of Orthopaedic Surgeons (AAOS).** (2022). *Management of PCL Injuries: Clinical Practice Guideline*.
9. **Tibor, L. M., & Sekiya, J. K.** (2016). *Arthroscopic management of PCL avulsion fractures*. Oper Tech Sports Med, 24(3), 123–129.
10. **Wang, J. H., et al.** (2015). *Comparison of arthroscopic and open reduction internal fixation for PCL avulsion fractures*. Orthop J Sports Med, 3(11), 2325967115613452.