New concepts in PCL injuries

Khalil Allah Nazem.MDFeb.2013

Feb.2013

Anatomy

Feb.2013

Anatomy

Feb.2013

Anatomy

Feb.2013

• 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.

Biomechanic

Feb.2013

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

Biomechanic

Feb.2013

• 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 tibial subluxation.

Biomechanic

Feb.2013

• 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

Biomechanic

Feb.2013

• Careful exams before operation and gap test during arthroscopy define associated ligaments injuries.

Summery

Feb.2013

Gap test

Feb.2013

• 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 tibial rotation may be due to anterior medial plateau subluxation, medial structure deficiency alone or in combination with the ACL ruptures.

Biomechanic

Feb.2013

• 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 tibial plateau.

• The presence of varus recurvatum in supine and standing is carefully assessed.

Clinical tests

Feb.2013

Clinical tests

Feb.2013

• 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 varus malalignment 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.

Imaging studies

Feb.2013

Posterior stress X-ray

Feb.2013

PCL deficiency treatment

Feb.2013

• 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.

Natural history

Feb.2013

• 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.

Natural history

Feb.2013

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

Non operative treatment

Feb.2013

• 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.

Non operative treatment

Feb.2013

• 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.

Non operative treatment

Feb.2013

• 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

• Mid substance: controversy.• Avulsion or peel- off = good result.• Augmentation of partial PCL tears =

controversial.

Treatment of acute PCL ruptures

Feb.2013

Treatment rationale of acute P.C.L tears

Feb.2013

Feb.2013

Feb.2013

Treatment of chronic P.C.L ruptures

Feb.2013

• Tibial attachment 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.

Operative techniques

Feb.2013

Operative techniques

Feb.2013

Operative techniques

Feb.2013

• 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

Operative techniques

Feb.2013

Operative techniques

Feb.2013

Operative techniques

Feb.2013

• 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).

Operative techniques

Feb.2013