Shear fractures of the capitellum.

This case demonstrates a rare injury to the elbow. Shear fractures of the capitellum can be communicated like in this case. Comminution can make treatment difficult. This is a retired woman in her 50s who fell on the left elbow. She has as seen on plain radiographs and 3D reconstruction a comminuted fracture of the capitellum and anterior subluxation of the radial head. Operative fixation requires preservation of the LCL and a LCL sparing lateral approach.

Tips:

1. Kocher LCL sparing lateral approach to the elbow with the incision on the skin 2cm anteriorly compared to the classic approach

2. Preservation of the LCL. Develop interval between anconeus and ECRB/ECRL. Avoid excessive retraction anteriorly over common extensor mass that can damage the radial nerve.

3. Excision of bone fragments that are too small to be fixed. Visualization of the trochlear - capitellum area to avoid medial step-off at the articular surface

4. Anterior to posterior headless screws have better chances of healing of the fracture compared to posterior to anterior. Vascularity of distal humerus is rich and comes from the posterior aspect of the elbow

5. Disadvantage of AP screws is that in case of AVN or non union the screws can became prominent and lead to DJD of the radial head and elbow.

A similar case of a capitellum shear fracture with free fragments in the joint is demonstrated below. Removal of free fragments was performed and the largest fracture was fixed with "minimal drilling" using a threaded K wire to avoid pin migration and a headless compression screw. The patient had a preoperative QuickDASH score of 79 and postoperative QuickDASH score of 0 (0 means no limitation in function). The patient was pain free with full ROM to the elbow at 6 months postoperatively. 

 Preoperative lateral view

 Preoperative AP view showing the comminution

3D reconstruction of the fracture on CT

 6 months postoperatively

 6 months postoperatively, no AVN

 3 months postoperatively

 3 months postoperatively fracture line still visible

3 months postoperatively fracture line still visible

Elbow fractures in the elderly. The Monteggia variant fracture with associated fracture dislocation of the radial head.

This is a 74 y/o F with a fracture dislocation of the radial head and an associated fracture of the proximal ulna. This mechanism represents a variant of the Monteggia fracture pattern. It is preferable to have a low threshold for replacement of the radial head. Fixation of the radial head can be challenging in this age group due to (1) Poor Bone quality (2) Comminution

It should be highlighted that in this injury pattern it is of great importance to reduce the ulnar fracture to the best anatomic position. In situations like in this case the comminution at fracture side can be an obstacle to anatomic reduction. The reasoning behind this recommendation is that the interosseous membrane and ligamentous interconnections of the proximal ulna to the radial head will directly affect the position of the radial head relative to the distal humerus. In other words, if the ulnar fracture is malreduced then the radial head with stay in a malreduced position in the form of subluxation or dislocation that is irreducable in the operating room. Even worse scenarios are when it is reduced in the operating room but it represents an unstable condition and dislocation is  seen later on at the initial postoperative xrays in the office.

In addition, it is important to avoid overstuffing of the radiocapitellar joint by choosing a smaller radial head implant (one size down to the native head) and avoid prominence of the head in relation of the articular surface of the ulna. Overstuffing leads to stiffness, pain and early arthritis.

At 3 months postop the fracture has healed and the patient had ROM of 10-140 flexion with 70 to full supination/pronation

Xrays of this case as shown above.

Proximal humerus fracture dislocation. How to fix

A 64 y/o F non smoker presented with a proximal fracture / anterior shoulder dislocation. At the time of presentation she was neuro-vascularly intact. The mechanism of injury was a mechanical fall on the ground during walking.

Preoperative evaluation demonstrated a fracture of the proximal humerus with an anterior dislocation. In most situations and in the acute settings -ie ER environment- it is difficult to obtain good Grashey x-rays of the shoulder. She had a CT scan that was used to verify the dislocation seen on the scapular Y view (anterior dislocation) and also help with the treatment algorithm ie fixation vs arthroplasty.

Preoperative XRs and CT scan are shown below:

The AP shoulder x-ray is "suspicious" of dislocation based on the overlap of the humeral head to the glenoid (projection). The scapular Y XR demonstates the anterior humeral head dislocation. The CT confirms that there is no head split from the dislocation or fracture and that the head is dislocated anteriorly.

Fixation of the fracture requires

(1) Elimination of the varus inclination

(2) Reduction of the dislocation

(3) Fixation of the greater tuberosity fragment to the head.

Reduction of the dislocation was performed with minimal soft tissue dissection. After the exposure of the fracture site through a deltopectoral approach a heavy Steinman Pin was inserted to the head of the humerus from an anterior to posterior direction. This pin was used for (1) Reduction of the dislocation and manipulation and alignment of the fracture relative to the shaft on the coronal plane. After the reduction two K wires were used for head-to-shaft provisional fixation and one K-wire for greater tuberosity to head fixation.

The construct was finished with a 3.5mm locking plate with the following goals
(1) Restoration of head to neck and shaft angle-Avoid varus or valgus
(2) Verification on the axillary view that the dislocation was reduced
(3) Stable fixation at the medial calcar with no step off ideally with at least one or two calcar locking screws.

Of note if there was a small <25% glenoid bony Bankart lesion then FIXATION IS NOT NECESSARY. Most of the time the postoperative stiffness compensates for the potentially instability. Fixation of the glenoid would contribute to the stiffness that is an associated problem in proximal fracture fixation

Posterior fracture dislocations are approached using the same principles. Most of the time these injuries are the result of seizure disorders. For the young patient with preserved humeral head  (>85%), open reduction and internal fixation (ORIF) may be the treatment of choice, although it remains unclear whether the hemi-arthroplasty or the ORIF is superior in achieving an acceptable outcome without the need for subsequent surgery. Most ORIF cases are revised for AVN, stiffness or failure of the construct. Most hemi-arthroplasties for non healing of the tuberosities, limited motion, instability, or infection. It is desirable to avoid replacement if the anatomy of the proximal humerus can be restored with ORIF and cancellous or cortical bone grafting. An unstable or dislocated hemi-arthroplasty due to uncontrolled seizures is a very difficult problem to treat and the only available option would be a conversion to a reverse shoulder replacement which could also be complicated by instability. Images below demonstrate a case that was approached with ORIF although by radiographic criteria a hemiarthoplasty could have been offered as well.  

 After reduction of the dislocated humeral head it is demonstrated that there is bone loss at the greater tuberosity area. 

 The fibular allograft was placed laterally instead of medially (calcar area) because the bone loss was more severe laterally closer to the greater tuberosity.