- 4 segment frx is most difficult to treat & is assoc w/ poorest results;
- vascular supply to the humeral head
- added to problems of three part frx, namely delayed union or non union, is avascular necrosis of the humeral head;
- the classic teaching is that the fragment is devoid of all soft tissue, making AVN certainty, irrespective of treatment;
- as noted by Darder, et al (1993), only 9 of 35 patients w/ four part frxs developed AVN, and further, the results were satisfactory or better in 21/35 patients;
- pathognomic feature is the small, crescentic, proximal articular fragment severed from the antatomic neck of the humerus;
- Four-part displaced proximal humeral fractures: operative treatment using Kirschner wires and a tension band.
- Surgical Treatment:
- if small head fragment is impacted and not acting as a mechanical block to movement, surgery should be avoided, as attempts at open reduction may
destroy any remaining blood supply;
- avulsed abductor mechanism, often in one large fragment consisting of greater & lesser tuberosity w/ intervening long head of biceps tendon, may be
replaced w/o disturbing impacted head;
- formal open reduction:
- relative contra-indications include 4 part frx dislocations, marked comminution, and patients older than 75 years of age;
- performed thru a deltopectoral approach;
- exposure can be facilitated by detaching 2-3 cm of the anterior deloitd from the clavicle;
- long head of the biceps helps to serve as a landmark for reduction;
- shoulder arthroplasty:
- relative indications include 4 part frx dislocations, marked comminution, and patients older than 75 years of age;
- ref: Hemiarthroplasty versus nonoperative treatment of displaced 4-part proximal humeral fractures in elderly patients: a randomized controlled trial.
Open reduction and internal fixation of three- and four-part fractures of the proximal humerus.
Functional Outcomes for Surgically Treated 3- and 4-part Proximal Humerus Fractures
Hemiarthroplasty versus nonoperative treatment of displaced 4-part proximal humeral fractures in elderly patients: a randomized controlled trial