New concepts in PCL injuries

1. New concepts in PCL injuries Khalil Allah Nazem.MD Feb.2013 Feb.2013

2. Anatomy Feb.2013

3. Anatomy Feb.2013

4. Anatomy Feb.2013

5. Biomechanic • Femoral attachment location of a graft determines the graft tibiofemoral separation distance with knee flex- ext. • On the femur prox-distal location of a graft has a greater effect on the attachment separation distance than the ant-post location. • Fibers of femoral PCL attachment progressively loading from distal to proximal with increasing knee flexion. Feb.2013

6. Biomechanic • The PCL is a primary restraint to posterior tibialtranslation throughout knee flexion ,with the exception of small increase in posterior translation with full extension when PLS is cut. Feb.2013

7. Biomechanic • The PLS represent one of the most important secondary restraints in posterior translation and has a major effect on the lateral tibiofemoral compartment translation. • Clinically it is advantageous to reconstruct the PCL before the loss of these secondary restraints. Otherwise the PCL graft is placed under greater forces because the secondary restraints are not able to share a portion of the load in resisting posterior tibialsubluxation. Feb.2013

8. Biomechanic • In chronic cases with loss of secondary restraints new papers recommended reconstruction of these structures during PCL reconstruction. • Loss of PLS and PMS increase lateral and medial joint opening in valgus and varus test and PCL and ACL become primary restraint against varus and valgus . • If these structures are not reconstruct ACL and PCL become primary restraint and under load →failure Feb.2013

9. Summery • Careful exams before operation and gap test during arthroscopy define associated ligaments injuries. Feb.2013

10. Gap test Feb.2013

11. Biomechanic • There are two primary restraints to external tibial rotation the PLS at low flexion and PLS + PCL at high flexion angles. Injury to FCL and PLS produces an increase in external tibial rotation and a posterior subluxation of the lateral tibial plateau. • Abnormal external tibialrotation may be due to anterior medial plateau subluxation, medial structure deficiency alone or in combination with the ACL ruptures. Feb.2013

12. Clinical tests • Medial posterior tibiofemoral step- off on PDT in 90o flexion (partial or complete), MRI is not always accurate for diagnosing partial PCL tears. • Arthrometer is useful but verifying with lateral stress view is more correct. • The integrity of the ACL is determined by Lachman and PST. Medial and lateral ligament insufficiency are determined by varus and valgus stress test at 0o and 30o . • The tibiofemoral rotation dial test at 30 and 90o is done to determine whether increases in external tibial rotation exist with posterior subluxation of the lateral tibialplateau. • The presence of varusrecurvatum in supine and standing is carefully assessed. Feb.2013

13. Clinical tests Feb.2013

14. Imaging studies • AP, lat (30o flexion), WB PA (45o), axial view during initial exams .Posterior stress X-ray (20 pounds) in 90o flexion. The difference more than 8mm indicates complete PCL rupture • Medial or lateral stress X-ray of both knees (20P) • Alignment standing view. • If the varusmalalignment is not corrected, there is a risk that a PCL or ACL graft may fail because of the varus thrusting forces and concurrent increased lateral joint opening, producing high graft tension loads. Feb.2013

15. Posterior stress X-ray Feb.2013

16. PCL deficiency treatment Feb.2013

17. Natural history • Minimal symptoms many years later (traditional). • Significant DJD in 80% if treated after 4 years. • Most reports consider the problem of functional instability and few emphasize the potential for DJD, however functional instability may not be the major symptom of an isolated PCL deficiency. Pain,aching during activity and effusion may be the result of articular cartilage degeneration, which often begins several years before X-ray changes. Feb.2013

18. Natural history • PCL deficiency has more deleterious effect in a varus-angled knee with associated loss of medial meniscus and in particular larger athletes desiring a return to strenuous athletes. • Treatment of PCL injuries is perhaps the most controversial current topic in knee surgery primarily because of unknown natural history. Feb.2013

19. Non operative treatment • Historically most studies indicate that grade I, II injuries respond well to non operative treatment, at least at short term Feb.2013

20. Non operative treatment • The commonly quoted criteria for non operative treatment include. • PDT less than 10mm. • Less than 5o abnormal rotary laxity. • No significant valgus- varus abnormal laxity. • 85% of these patient return to sport activities regardless of the grade of laxity. • Despite these encouraging report it is clear that not all knee of isolated PCL deficiency do well. More recent longer term studies have shown knee function tends to deteriorate over time and complain pain with walking long distance, standing, climbing and squatting, knee stiffness and giving way. Feb.2013

21. Non operative treatment • PCL deficiency →posterior subluxation →increase load in P-F and medial compartment and lateral compartment less affected. • Patients treated non operatively should be observed closely for symptoms of DJD or functional deterioration. Feb.2013

22. After extensive experience with operative and non operative treatment Shelbourne recommended for all acute isolated grade I and most grade II non operated method • In high demand isolated grade II or more laxity Acute PCL repair or reconstruct recommended • In chronic isolated PCL deficiency with residual grade II or greater that is symptomatic Other associated injuries such as meniscal or condral damage are identified that may account for the symptoms. If symptoms related to PCL and relieved with PCLD brace PCL reconstruction recommended • Result of stability and symptom free and prevention of DJD after PCL reconstructive is not reliable . Feb.2013

23. Treatment of acute PCL ruptures • Mid substance: controversy. • Avulsion or peel- off = good result. • Augmentation of partial PCL tears = controversial. Feb.2013

24. Treatment rationale of acute P.C.L tears Feb.2013

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27. Treatment of chronic P.C.L ruptures Feb.2013

29. Operative techniques • Tibialattachment techniques • Arthroscopic all inside • Open tibial inlay • All inside: simple, faster, dangerous, in multiple ligament injury • Exceptions for all inside is avulsions of PCL and revisions with bone defect in tibial attachment . • Open tibial inlay: place a tibial inlay graft securely in the tibial attachment site. Use when only PCL is ruptured provide ideal graft fixation and early healing (QT-PB). • All inside has the disadvantage of graft abrasion. Feb.2013

30. Operative techniques Feb.2013

31. Operative techniques Feb.2013

32. Operative techniques • PCL femoral attachment (2tunnel versus I tunnel) • Outside- in is prefer especially when bone plug used for tibial attachment • One in 4 o’clock and another in one o’clock ,4 is 1-1.5cm shorter. This technique allows determining the ideal knee flexion position for graft fixation • In one tunnel: rectangular femoral slot technique is prefer to one large tunnel Feb.2013

33. Operative techniques Feb.2013

34. Operative techniques Feb.2013

35. Operative techniques • Single strand versus two strands PCL graft construction • It appears that there are sound theoretical reasons to warrant a two strand PCL reconstruction when clinically feasible. These conditions includes isolated PCL reconstruction (good time). Feb.2013