Ponticulus posticus of atlas vertebra

☆ The ponticulus posticus means "little posterior bridge" in Latin. 

☆ Ponticulus posticus occurs due to calcification of the oblique atlanto-occipital ligaments and is known by many names such as Kimerle foramen, foramen arcuale atlantis or arcuate foramen.

☆ It was defined as an abnormal small bony bridge formed between the posterior portion of the superior articular process and the posterolateral portion of the superior margin of the posterior arch of the atlas.

☆ It has a variable morphology, can be complete or incomplete and may be unilateral or bilateral.

☆ Literature reveals a higher incidence in females compared with males and this anomaly was age independent.

☆ The sulcus situated on the posterolateral margin of the atlas forms a groove for the vertebral artery. The vertebral artery (atlantic portion V3 )  passes through this foramen.

Common total hip arthroplasty postoperative radiographic findings and complications around the prosthesis

This image is an annotated X-ray of a total hip arthroplasty (THA) showing common postoperative radiographic findings and complications around the prosthesis. Here's a clear breakdown of each labeled term:

🔶 Heterotopic Ossification:

Definition: Bone formation in soft tissues where bone normally does not exist.

Radiographic finding: Irregular ossification around the joint, usually periarticular.

Clinical note: Common after hip surgery; may restrict motion.

🔶 Stress Shielding:

Definition: Localized bone loss (osteopenia) due to altered load distribution — the metal prosthesis bears more stress than the bone.

Radiographic finding: Thinning of the proximal femoral cortex, especially in the calcar region.

🔶 Aseptic Loosening:

Definition: Failure of the bond between bone and prosthesis without infection.

Radiographic finding: Periprosthetic lucent zones (>2 mm), often progressive, around the stem or cup.

Mechanism: Micromotion and fibrous tissue interface formation.

🔶 Septic Loosening:

Definition: Loosening due to infection.

Radiographic finding: Rapidly progressive lucency with periosteal reaction or bone destruction.

Key distinction: Infection causes aggressive and irregular bone changes compared to aseptic loosening.

🔶 Spot Welding:

Definition: Endosteal bone formation in direct contact with the prosthesis.

Radiographic finding: Localized areas where bone density increases along the stem — indicates good osseointegration (favorable sign).

🔶 Fibrous Membrane:

Definition: Thin fibrous interface (< 2 mm) between bone and prosthesis.

Radiographic finding: Narrow radiolucent line with a thin sclerotic border — often stable and non-progressive.

🔶 Periprosthetic Fracture:

Definition: Fracture of the bone surrounding the prosthesis, usually due to trauma or stress.

Radiographic finding: Commonly occurs near the tip of the femoral stem.

Classification: Often described by the Vancouver classification (location and implant stability).

🔩 Common Fixation Devices Used for AC Joint / Distal Clavicle Surgery

🔩 Common Fixation Devices Used for AC Joint / Distal Clavicle Surgery:

1. Hook Plate – a contoured plate that hooks under the acromion to stabilize the distal clavicle.

Radiographically: long plate along the clavicle with a hook projecting beneath the acromion.

2. Clavicular Locking Plate – low-profile plate with multiple screws along the distal clavicle.

Radiographically: several screws seen linearly along the clavicle.

3. EndoButton / TightRope (Suture-Button Device) – two small metallic buttons connected by a high-strength suture for coracoclavicular ligament reconstruction.

It is a suture-button device used to stabilize the coracoclavicular (CC) joint, typically for severe acromioclavicular (AC) joint separations or distal clavicle fractures. The surgical procedure involves drilling tunnels through the clavicle and coracoid process and then passing a strong suture with two buttons through these tunnels.The buttons are then secured on either side of the bone, effectively mimicking and reinforcing the natural CC ligaments, which holds the clavicle and coracoid together. 

Radiographically: On standard AP or scapular Y views:

Superior button (clavicular side): appears as small, round or rectangular metallic opacity over the superior surface of the distal clavicle. Usually the most visible part (seen end-on).

Inferior button (coracoid side): Often faint or obscured by overlying bone of the coracoid or glenoid. May appear as a second small metallic density inferior to the clavicle, but not always distinct on AP view.

Connecting suture is radiolucent (not seen). Only the buttons are radiopaque.

Double J Ureteric Catheter (DJ Stent)

1. Definition & Purpose:

A Double J stent is a thin, flexible tube placed in the ureter to ensure urine drainage from the kidney to the bladder.

The term “Double J” refers to the curled (J-shaped) ends — one in the renal pelvis and the other in the bladder, preventing migration.

2. Indications:

● Post-ureteric surgery (e.g., pyeloplasty, ureteric reimplantation)

● Obstructive uropathy (stone, tumor, stricture, edema)

● Post-lithotripsy or ureteroscopy

● Urinary leak prevention (after trauma or

 surgery)

3. Imaging Appearance:

Modality Appearance / Key Points

● X-ray KUB : Radiopaque linear tubular structure with curled ends—one in renal pelvis, one in bladder. Verify both ends visible and in correct position.

● CT (non-contrast) : Clearly visualized as a hyperdense linear structure along ureter’s course. Confirms position and checks for obstruction, migration, or encrustation.

● Ultrasound : Echogenic line with posterior shadow; sometimes only proximal/distal curls seen. Used to detect hydronephrosis or stent-related complications.

● Fluoroscopy Used during insertion/removal—real-time visualization of correct coil placement.

4. Correct Position:

● Proximal end: in renal pelvis or upper calyx.

● Distal end: within bladder lumen.

● Shaft follows ureteric path without kinking.

5. Complications & Radiologic Findings:

Complication, Imaging Findings / Notes

● Migration / Malposition Coil seen outside expected area (e.g., proximal coil in ureter or distal coil in urethra).

● Encrustation / Calcification Irregular hyperdense deposits along stent; better seen on CT or X-ray.

● Fragmentation / Fracture Discontinuity of stent; may cause obstruction.

● Infection / Pyelonephritis. In CT displayed as: perinephric stranding and hydronephrosis.

● Forgotten stent : Encrustation, stone formation and  hydronephrosis.

🦵 TYPES OF ACL REPAIR & RECONSTRUCTION TECHNIQUES

🔹 Primary ACL Repair (Direct Repair)

Definition: Reattachment of the torn native ACL to its femoral or tibial footprint, preserving the original ligament.

Indications:

Proximal (femoral-sided) tears

Good tissue quality

Often in acute injuries (<3 weeks old)

Techniques:

Suture anchor repair (reattaching ACL to femoral wall)

Suture augmentation/internal brace (using FiberTape or similar to protect repair during healing)

Examples:

Arthroscopic primary ACL repair with suture anchors (e.g., “BEAR,” “InternalBrace”)

🔹 Biologic-Enhanced ACL Repair

Definition: Augmenting primary repair with biological scaffolds to improve healing.

Types:

BEAR (Bridge-Enhanced ACL Repair): Uses a collagen scaffold saturated with autologous blood to bridge torn ends.

Stem cell or PRP-assisted repair: Under research; aims to enhance ligament healing biologically.

🔹 ACL Reconstruction (Graft-Based Replacement)

When native ACL cannot be repaired (most common), a graft is used to reconstruct it.

a. Autograft Reconstruction

Using patient’s own tissue:

Hamstring tendon graft (most common)

Bone–Patellar Tendon–Bone (BPTB) graft

Quadriceps tendon graft

Each has different pros/cons:

Graft Advantages Disadvantages

Hamstring Smaller incision, less anterior knee pain Slower graft incorporation

BPTB Bone-to-bone healing, strong fixation Anterior knee pain, kneeling discomfort

Quadriceps Good graft size, less donor-site pain May cause temporary extensor weakness

b. Allograft Reconstruction

Uses donor tissue (e.g., Achilles, tibialis anterior)

Pros: shorter surgery, no donor morbidity

Cons: slower incorporation, higher re-tear rate (especially in young athletes)

🔹 Hybrid Techniques

Combination of repair and reconstruction — for example:

Augmented repair + partial graft if some ACL fibers remain intact.

ACL remnant-preserving reconstruction to retain proprioceptive fibers.

🔹 Dynamic Intraligamentary Stabilization (DIS)

Technique: Uses a dynamic spring screw (e.g., Ligamys system) to stabilize ACL during healing.

Goal: Promotes natural healing while preventing anterior tibial translation.

The intramedullary nail

An intramedullary nail is a metal rod inserted into the medullary cavity of a long bone to treat fractures. This surgical procedure stabilizes the bone, acting as an internal splint to help the bone heal and allowing for earlier weight-bearing. Common bones treated with this method include the femur, tibia, and humerus. 

Bile duct

A bile duct is a tube that carries bile from the liver and gallbladder to the small intestine, where it helps digest fats. The system includes both tubes within the liver (intrahepatic) and tubes outside the liver (extrahepatic). Blockages in the bile ducts can lead to health problems, such as gallstones or cancer, causing symptoms like jaundice.

Hallux Valgus

Hallux Valgus, commonly referred to as a bunion, is a complex valgus deformity of the first ray that can cause medial big toe pain and difficulty with shoe wear.

Diagnosis is made clinically with presence of a hallux that rests in a valgus and pronated position. Radiographs of the foot are obtained to identify the severity of the disease and for surgical planning.

Treatment can be nonoperative with shoe modifications for mild and minimally symptomatic cases. Surgical management is indicated for progressive deformity and difficulty with shoe wear. 

Os vesalianum vs os peroneum

The os peroneum is an accessory bone found within the peroneus longus tendon near the cuboid bone, while the os vesalianum is a rare accessory bone located near the base of the fifth metatarsal within the peroneus brevis tendon. The os peroneum is a more common accessory ossicle, whereas the os vesalianum can be confused with an avulsion fracture of the fifth metatarsal. Painful os peroneum syndrome typically involves the peroneus longus tendon, while a symptomatic os vesalianum can cause pain near the base of the fifth metatarsal.