Advanced Orthopaedic Clinic

26/03/2026

25/03/2026

24/03/2026

24/03/2026

24/03/2026

24/03/2026

24/03/2026

Anterior Cruciate Ligament (ACL) Tears
{ Clinical Evaluation and Management }

The ACL is the primary stabilizer preventing anterior translation of the tibia on the femur. It consists of two bundles: the anteromedial (taut in flexion) and the posterolateral (taut in extension).

1. Mechanism of Injury
While contact injuries occur, most ACL tears are non-contact deceleration injuries involving:

Valgus stress and external rotation.

Landing from a jump in hyperextension with internal rotation (common in basketball).

Patient Report: A sudden "pop," acute pain, and "giving way" (instability). It is a leading cause of acute traumatic hemarthrosis (blood in the joint).

2. Physical Examination & Special Tests

Lachman Test (Most Sensitive):
* Performed at 20° of flexion. One hand stabilizes the femur while the other pulls the tibia anteriorly.

Positive: Significant anterior translation and a "mushy" or absent end point.

Note: Ensure the PCL is intact to avoid a false positive from a "posterior sag."

Anterior Drawer Test: * Performed at 90° of flexion. The clinician pulls the tibia forward.

While traditional, it is often less sensitive than the Lachman due to hamstring guarding or meniscal wedging.

Pivot Shift Test: * This identifies functional instability (subluxation-reduction). With the knee in extension, a valgus force and internal rotation are applied while slowly flexing the knee.

Positive: At 20°–40° of flexion, the tibia "clunks" back into place as the IT band transitions from an extensor to a flexor.

3. Imaging : The Segond Fracture
On plain radiographs, look for a Segond fracture—a small avulsion fragment of the lateral proximal tibia. This is considered pathognomonic for an ACL tear and indicates significant anterolateral instability.

4. Treatment Strategies

Non-Operative: Reserved for low-demand patients who do not perform cutting/pivoting. Focuses on intensive rehabilitation. However, neglect can lead to secondary meniscal tears and early-onset osteoarthritis.

Operative (ACL Reconstruction):
Recommended for young, active patients to restore stability.

Graft Choice:
* Autograft (Hamstring or Patellar Tendon): Preferred in young patients due to lower failure rates.
* Allograft (Donor tissue): Often used in older patients (>40) to avoid harvest-site morbidity.
Growth Plates: In children (skeletally immature), "physeal-sparing" techniques are used to avoid leg length discrepancies.

Clinical Pearl:
"The Lachman test is the gold standard for clinical diagnosis because at 20° of flexion, the secondary stabilizers (like the menisci) are less engaged, allowing you to feel the true integrity of the ACL. If you feel a 'soft' end point, the diagnosis is an ACL tear until proven otherwise by MRI."

24/03/2026

Patellar Fractures

Patellar fractures usually result from a direct blow (like a "dashboard injury" in a car crash), a fall onto the knee, or a sudden, forceful contraction of the quadriceps during a stumble.

1. Clinical Presentation
Physical Findings: Look for swelling, localized tenderness, and palpable deformity. Open wounds are common due to the subcutaneous nature of the bone.

Functional Deficit: The patient is typically unable to perform a straight leg raise (SLR). This indicates a disruption of the extensor mechanism.

Differential: It is important to distinguish a fracture from a bipartite patella (a natural anatomical variant where the bone is in two pieces, usually at the outer upper corner), which is typically asymptomatic and has smooth edges on X-ray.

2. Radiological Evaluation
AP and Lateral Views: Used to assess the fracture pattern (transverse, stellate, or vertical) and the amount of displacement.

Skyline View: Helpful for identifying vertical or osteochondral fractures that aren't visible on standard views, though this can be painful for the patient to position.

3. Management Strategies
Non-Operative
Indication: Undisplaced fractures (especially vertical ones) where the patient can still perform a straight leg raise.

Treatment: Immobilization in a hinged knee brace for 6 weeks, allowing full weight-bearing.

Operative (Tension Band Wiring)
Most displaced fractures require surgery to restore the smooth articular surface of the knee joint.

Mechanism: The Tension Band Technique converts the natural "pulling" (distraction) forces of the quadriceps into "squeezing" (compression) forces at the joint surface.

Procedure:
1. Longitudinal K-wires are placed to prevent the fragments from sliding.
2. A stainless steel wire is looped in a figure-of-eight pattern behind the K-wires.
3. As the knee flexes, the wire tightens, pushing the bone fragments together.

Alternative Techniques: For complex (stellate) fractures, surgeons may use cerclage wires (circling the bone) or cannulated screws.

4. Recovery and Rehabilitation
Union Time: On average, the patella takes 6 weeks to unite.

Movement: Post-operatively, a restricted range of motion (usually 0–45°) is permitted in a hinged brace to prevent stiffness while protecting the hardware.

Weight-Bearing: Patients are typically allowed to weight-bear fully in their brace immediately.

Complications: A patellectomy (complete removal of the bone) is a last-resort for "unreconstructable" shattered fractures, but it significantly reduces quadriceps strength.

Clinical Pearl:
"When performing the tension band technique, the figure-of-eight wire must be placed as close to the bone as possible. If it is too superficial in the soft tissue, it won't provide the compression needed, and the hardware is much more likely to irritate the patient's skin later on."

23/03/2026