Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Tuesday, October 30, 2018

Olecranon Fractures


Fractures of the olecranon may occur due to a direct blow to the elbow or from a fall onto an outstretched hand. Nondisplaced fractures have less than 2mm of separation and are considered stable. Fracture separation will not increase with elbow flexion. Extensor mechanism is intact and the patient will be able to extend the elbow against gravity. Displaced fractures could be an avulsion, oblique, transverse, comminuted, or dislocated.
Olecranon fracture dislocations can be anterior (transolecranon) or posterior (similar to monteggia fracture dislocation). An examination will show that the patient is unable to extend the elbow with these displaced fracture types. A true lateral view x-ray will clearly show the olecranon fracture. Usually, these fractures are followed by stiffness of the elbow in about 50% of the patients. However, this does not affect the function.
The goal of treatment for olecranon fractures should be restoration of the articular surface, preservation of the continuity of extensor mechanisms, maintain elbow stability, and avoid stiffness of the elbow. Nonoperative treatment is used for nondisplaced fractures and it may be used for some displaced fractures in elderly patients (treat elbow in some flexion with a splint). I would personally use minimally invasive techniques in these patients unless the skin is very bad, or the fracture is very comminuted.
There are three techniques used for surgical treatment: the tension band technique, detach olecranon and reattach triceps, and plate and screw fixation. The tension band technique is only used for transverse fractures with no comminution. K-wires and screws are used, and the surgeon may use either a 6.5mm screw or Kwires for the tension band. When doing the tension band technique, you want to engage the anterior cortex of the ulna. The surgeon should avoid over penetration to avoid affecting the forearm rotation or injuring the anterior interosseous nerve. The surgeon needs to be sure that the pins are not fixing the radius and that after the operation, the patient can perform pronation and supination of the forearm (pull the pins out slightly if needed). The distractive force of the triceps is converted to compression force at the articular surgace, especially when bending the elbow. The drill hole for the K-wire should be positioned about 4-5cm from the fracture which gives enough safe distance so that the fracture will not propagate. Place the tension band wire through the drilled holes before application of the K wires. The surgeon should be sure that the hook to the K-wire is posterior. Make sure that the tension band wire is close to the bone so there is no laxity in the fixation and instability. An intramedullary screw could be used. This screw fixation may need a washer to capture the tension band wire. Intramedullary 6.5mm screw fixation is a reasonable option for fixation but it may need to be supplemented with tension band wires. Never use cancellous screw alone. The tension band technique are for transverse fractures of the olecranon. If fractures comminution is present, change the plan of fixation.

When detaching the olecranon and reattaching the triceps, an excision of the fracture fragment and triceps advancement is used:

  • If the fracture is less than 50%
  • To treat elderly patients (especially if fracture is comminuted)
  • For some nonunions when the fracture is small and cannot be fixed

The surgeon must be sure that the procedure is done with the elbow is stable. If the elbow has ligamentous instability and excision of the fracture fragment is done, this will make the elbow very unstable. The triceps should be attached closer to the articular surface.
Special olecranon plates are available when using a plate and screw fixation technique. The bridge plate and screw fixation technique is used in comminuted, Monteggia, oblique fractures extending to the coranoid, and fracture dislocation. The plate is placed on the tension side of the olecranon (dorsal side). Sometimes, an opening is made through the triceps and the plate is placed against the bone, then suturing the triceps tendon over the plate to avoid hardware prominence.
In summary, if the patient is elderly with a small, comminuted fracture fragment less than 50% of the joint space, excise the fragment, and reattach the triceps tendon to the olecranon. If the olecranon fracture is transverse and proximal to the base of the coranoid process, then use the tension band technique. Use plate fixation for all olecranon fracture scenerios, such comminuted fractures, oblique fractures, unstable fractures, dislocation, or fractures distal to the coranoid process. The typical exam question scenario will discuss a comminuted fracture that should be treated with a plate. You probably need to remove above 20% of the plate fixations due to hardware irritation. Hardware irritation is worse with the tension band surgical treatment (may need to remove in more than 50% of cases).

Friday, March 2, 2018

Clay Shoveler’s Fracture


A clay shoveler’s fracture is a stable fracture through the spinous process of the vertebra C6-T1 and typically occurs at the level of C6 or C7. Clay shoveler’s fracture gets its name from the common injury suffered by men diffing deep ditches in Australia during the 1930s.
Powerful hyperflexion of the neck combined with contraction of the paraspinous muscles during shoveling is the typical mechanism of injury. The tremendous force pulls on the spinous process, producing an avulsion fracture.
The fracture is best seen on a lateral view x-ray. There will be a ghost sign on AP view x-rays—double spinal process of C6 or C7, resulting from a displaced fractured spinous process.
Stable fractures can be treated nonoperatively, utilizing a collar and physical therapy.

Friday, January 12, 2018

PIP Dorsal Fracture Dislocation


Proximal interphalangeal (PIP) dorsal fracture dislocations can be challenging in management. In PIP dorsal fracture dislocations, there is an involvement of the articular surfaces of the joint. These injuries are the most disabling PIP joint injuries. A reduction of the middle phalanx on the condyles of the proximal phalanx is the primary goal of treatment. The patient frequently presents with a chronic dorsal subluxation due to delay in seeking treatment or from failed treatment.


85% of motion for grasping objects occurs at the PIP joint. The PIP joint has the largest arc of motion (120 degrees) of the three joints in each digit.

There are three different types of injury:

  1. Hyperextension
  2. Impact Shear
  3. Pylon


In cases of Hyperextension injuries, the size of the fragment can range from a small piece of bone, up to 30% of the joint surface with minimal comminution (usually stable).  In order to provide accurate treatment, the physician will want to test the stability of the fracture and apply a dorsal blocking splint. It is important to observe the lateral view for any subluxation.


Impaction/Shear injuries are produced by an axial load applied to a slightly extended or flexed PIP joint. The middle phalanx is driven over the head of the proximal phalanx with comminution and impaction of the base of the middle phalanx. These injuries are characterized by the loss of the volar plate tether. A 50% loss of the palmar of the middle phalanx base will make the PIP joint unstable. The extensor tendon and superficialis tendon will aggravate the dorsal subluxation. Splints will be inadequate if the injury is not stable. Treatment will include skeletal traction and early range of motion. An open reduction and internal fixation may be necessary if the fragment is large enough. A Palmar Plate Arthroplasty may be considered to advance the palmar plate into the defect. This procedure will support the palmar plate by filling the defect behind it with fracture chips, bone graft, or by a superficialis slip. Chronic impaction/shear cases are a difficult problem and can be treated with an arthrodesis or volar plate arthroplasty.



A pylon fracture results from an axial force that fractures the volar and dorsal articular surfaces with impaction on the central part. A pylon fracture is not a true fracture dislocation and will not have a good outcome. Dynamic external traction should be done in order to help in ligamentotaxis. Early range of motion is important for remodeling of the joint.



Classification of a PIP Dorsal Fracture Dislocation will depend on the degree of involvement of the articular surface.

  • Type I (stable) <30%
  • Type II (tenuous)= 30-50%
  • Type III (unstable) > 50%

Treatment will consist of a Dorsal Extension Blocking Splint if the PIP can be reduced in less than 30% of flexion. If less than 40%, the joint involved and stable. For Type I and Type II fractures, decrease the flexion gradually every week. Type III fractures will require ORIF, volar plate arthroplasty, or hemi-hamate graft (if >40% joint involved and unstable).


With a Hemi-Hamate Graft, the damaged palmar lip of the middle phalanx with a size matched portion of the hamate bone obtained from its distal dorsal articular surface between the 4th and 5th metacarpals. It restores both articular congruity and osseous stability. Extension block pinning is probably a helpful technique. Treatment must provide stable reduction to allow for early mobilization.



Stability of the reduction depends on the size of the avulsed fragment and the amount of ligament remaining attached to the middle phalanx. If less than 40% of the articular segment is avulsed, some of the collateral ligament will be intact. This will keep the reduction stable. If more than 40% of the articular segment has avulsed, only very little or none of the ligament will remain attached to the base of the middle phalanx, rendering the reduction unstable.

Recognizing Subluxation

AP and lateral x-rays are necessary for diagnosis. An AP view will help to recognize impaction fractures.  Subluxation can be missed on x-rays. The physician will want to look for the characteristic “V” sign of diverging joint surfaces, which indicates injury and subluxation.


If a reduction of the avulsion fracture is achieved with less than a 30 degree bend, nonoperative treatment is a good choice. However, if it takes more than 30 degrees of flexion to reduce the fragment, this may be an indication for surgery.