- Discussion:
- comminuted fractures of the entire head;
-
classification:
- type A:
- fracture of the entire radial neck, with the head completely displaced from the shaft;
- type B:
- articular fracture involving the entire head, which consists of more than two large fragments;
- each fragment is completely displaced from the shaft;
- type C:
- fracture with a tilted and impacted articular segment, which must be reduced;
- articular fragments displaced from the shaft.
-
complex fractures:
-
radial head frx & elbow dislocation :
- injury to medial collateral ligament w/ dislocation can be subtle;
- apply valgus stress to judge instability;
-
radial head frx & MCL instability :
-
Essex Lopresti Fracture
- Radiographs:
- proximal translation of the radius;
- it is important to have adequate views of the wrist early on inorder to follow proximal radial translation later on;
- Treatment Options:
- w/ acute longitudinal radioulnar dissociation (
Essex Lopresti Fracture), attempt to preserve radial head;
-
excision of radial head:
- unlike
type II fractures, these fractures do not do well w/ delayed excision;
-
radial head implants:
-
internal fixation:
- AO screws: 1.5, 2.0 or 2.7 mm cortex, depending on size of fragment;
- most often 2.7 mm miniscrews are chosen and are countersunk to avoid screw prominence;
- if a coutnersink is to be used, be sure that the screw is not too long, so as the screw tip does not extend beyond the cortical surface;
- over drilling of the proximal fragment is not required (can result in fragment comminution), especially if the fragment is held in compression during screw insertion;
- for lag screw effect, 2.7 mm drill-gliding hole is made thru the near cortical fragment, which is followed by 2 mm drill hole;
- minicondylar plate;
- indicated if the head requires attachment to the neck;
- consider use of 2.0 or 2.7 mm L-shaped plate;
- Surgical Approach:
-
posterolateral approach: (
Kocher Approach)
- approach the fascial plane between the
ECU and
anconeus muscle
- direct
lateral approach is preferred by some surgeons because it spares the lateral ulnohumeral ligament;
- exposure can be enlarged w/ osteotomy of lateral epicondyle & its reflection anteriorly with the extensor muscle origins;
-
radial nerve is identified in the substance of the
supinator;
- temporary fixation with K wires following reduction;
-
safe zone for implant insertion:
- Complications:
- avascular necrosis:
- may occur following ORIF of comminuted fractures when most of the soft tissue attachements have been stripped;
- when this complication occurs and is symptomatic, a delayed excision may be performed once the capsulo-ligamentous structures have healed;
- non union:
- in the presentation by D. Ring et al (15 th Annual Meeting of Orthopaedic Trauma Association, 1999), the authors noted 7 patients with radial
head non union following ORIF on 70 patients;
- the authors point out that the limited blood supply may lead to the relatively high occurance of non union;
- Case Example:
Comminuted Fractures of the Radial Head. Comparison of Resection and Internal Fixation.
