Orthopaedics Unplugged

Concomitant Injuries associated with ACL Rupture:
1. Medial side: Unhappy triad
2. Lateral side: Lateral quartet

Mayfield Classification of Carpal Instability:
Stage 1: Scapho-lunate dissociation (Terry Thomas sign)
Stage 2: Perilunate dislocation
Stage 3: Midcarpal dislocation
Stage 4: Lunate dislocation (spilled teacup sign)

Significance of Watershed Line of Distal Radius:
- It is a surgical landmark lying distal to pronator quadratus and used for positioning a volar locking plate.
- It is 2 mm proximal to ulnar side joint line and 10-15 mm proximal to radial side joint line.
- Plate positioned distal to this line will lead to abrasion and subsequent tear of flexor tendons, most commonly being FPL.

Various Lateral-column shortening procedures used in Neglected or Recurrent CTEV:
1. Litchtblau procedure
2. Goldner procedure
3. Enucleation of Cuboid
4. Dilwyn-Evans procedure

Post-operative Radiographic Assessment of Hip Arthroplasty:
1. Leg length
2. Horizontal centre of rotation
3. Vertical centre of rotation
4. Acetabular Inclination
5. Femoral stem positioning
6. Acetabular anteversion
7. Cement Mantle
Note- every parameter is assessed on AP view except for acetabular anteversion which is measured on a lateral radiograph.

Interposition/ Fascial Athroplasty of Elbow:

It is a type of intervention to treat degenerative elbow conditions in patients who have a contra-indication to implant placement. It involves resurfacing of olecranon and humeral condyle followed by interposition of fascia lata (retrieved from thigh) over the humeral condyle. Widely used in developing countries.

Dorsal Horizon View:

- This newly described dorsal tangential view provides a more complete visualization of the triangular distal radius cortex, particularly at Lister’s tubercle, allowing for a more accurate assessment of screw protrusion.

- Obtained by supinating the forearm, hyperflexing the wrist, and aiming the beam of the image intensifier along the long axis of the radius.

PCL Balancing during Fixed bearing Cruciate Retaining TKR
POLO test: Pull-out Lift-off test
Pull-out test: Used to assess the knee for flexion laxity. With the trial components in place, the knee is flexed 90 degrees. The surgeon then tries to pull out the tibial component from underneath the femur. If the knee fails the pull-out test, thicker inserts are tried until pull-out no longer is possible.

Lift-off Test: With the same trial components in place, the knee is flexed between 80 and 100 degrees. If the PCL is too tight, it will pull the femur posteriorly on the tibia where the posterior condyles impinge on the posterior lip of the tibial insert, pushing it down in back with lift-off in front.
Causes of lift-off other than tight PCL:
-If the lift-off test is performed with the patella everted and the knee has a tight quadriceps mechanism.
-Failure to clear the posterior femur of uncapped bone or retained osteophytes.

GILULA Lines: used for assessing normal carpal alignment in AP view wrist.
Line I: drawn along the proximal convex curvature of the scaphoid, lunate and triquetrum.
Line II: drawn along the distal concave curvature of the scaphoid, lunate and triquetrum.
Line III: drawn along the proximal convex curvature of the capitate and hamate.

Triangular Fibro-Cartilage Complex (TFCC): It has 6 components namely-
– Central articular disc
– Dorsal and volar radioulnar ligaments
– Ulnar collateral ligament
– Meniscus homologue
– ECU Tendon sheath
– Ulnocarpal ligaments

Provocative tests for suspected TFCC injury-
1. Ulnocarpal impaction maneuver: It is performed by ulnarly deviating the wrist, applying an axial load, and flexing and extending the wrist. Pain with or without a “click” is a positive test.

2. Piano-key test: It is performed by applying a dorsal-to-volar load across the DRUJ. Evidence of DRUJ instability is a positive test.

AORI Classification of Bone defects in Revision TKR:
(Anderson Orthopaedic Research Institute)