The pivotal role of the intermediate fragment in initial operative treatment of olecranon fractures
© von Rüden et al; licensee BioMed Central Ltd. 2011
Received: 20 May 2010
Accepted: 10 February 2011
Published: 10 February 2011
In order to improve initial operative treatment of complex olecranon fractures we searched for new determining details. We assumed that the intermediate fragment plays a decisive role for anatomic restoration of the trochlear notch and consecutive outcome of initial operative treatment.
80 patients operated with diagnosis of complex olecranon fracture were identified in an 8-year-period from trauma unit files at two European Level 1 Trauma Centers. Retrospective review of all operative reports and radiographs/computer-tomography scans identified patients with concomitance of an intermediate fragment. The Patient-Rated Elbow Evaluation Score was calculated for 45 of 80 patients at a minimum of 8 months postoperatively (range 8-84 months).
29 patients were treated with stable internal fixation with figure-of-eight tension band wire fixation and 51 patients with posterior plate osteosynthesis with/without intramedullary screw. An intermediate fragment was seen in 52 patients. In 29 of these 52 patients, the intermediate fragment was described in operative report. 24 of these 29 patients were treated with posterior plate osteosynthesis, and 5 patients with figure-of-eight tension band wiring. Complications included superficial infection (2 patients), secondary dislocation (3 patients) and heterotopic ossifications (1 patient). Functional outcome demonstrated a total PREE score of 9 points on average in 45 of 80 patients.
An extraordinary amount of patients showed an intermediate fragment. Consideration, desimpaction and anatomic reduction of the intermediate fragment are necessary preconditions for anatomic restoration of the trochlear notch. There is no clear benefit for plating versus tension band wiring according to our data. In the operative report precise description of the fracture pattern including presence of an intermediate fragment is recommended.
Approximately 10% of fractures of the adult elbow involve the olecranon process of the proximal ulna and range from simple non-displaced fractures to complex fracture-dislocations of the elbow . The proximal ulna forms a 190 degree arc around the olecranon known as the trochlear notch . Articular surface incongruity of more than 2 mm leads to posttraumatic arthritis . Open reduction and internal fixation is the standard treatment for displaced olecranon fractures . The surgical technique is dependent on a variety of factors including patient factors, the fracture pattern, and the mechanical stability of the osteosynthesis applied to stabilize the fracture . Several treatment options for open reduction and internal fixation have been described, including tension band wiring , plate fixation, triceps advancement after fragment excision, intramedullary locking compression nailing and intramedullary screw fixation. The so called "home run" screw provides excellent fixation of the proximal fragment into the ulna shaft [1, 7–11]. Anatomic reduction and restoration of the joint surface and contour of the trochlear notch is essential for good outcome of olecranon fractures . However, long-term outcome following initial surgical management of complex elbow injuries is unknown . Primary elbow instability and fracture morphology are prognostic factors for elbow function and development of arthritis after operative treatment of olecranon fractures . Fixation or replacement of injured bony elements, ligamentous repair, and hinged fixation may be used to successfully manage complex elbow instability . There are several well-established classifications of olecranon fractures e.g. Mayo and Schatzker-Schmeling classification. Mayo classification type II and III and Schatzker-Schmeling classification type B and D describe an intermediate fragment of the trochlear notch which is frequently seen in comminuted olecranon fractures. Although the intermediate fragment is known to be critical for reconstruction and stabilization of the olecranon structure its importance is not reflected in established classifications.
As a result, fracture analysis lacks identification of the intermediate fragment in the diagnostic work up, operative reports do not describe in detail fracture pattern and presence of the intermediate fragment, and insufficient fracture reduction and unstable fixation techniques using figure-of-eight tension band wire fixation were used in many cases resulting in a high rate of revision surgery. Hypothesis of this study was that the intermediate fragment plays a key role for anatomic restoration of the trochlear notch contour and consecutive outcome of initial operative treatment of complex olecranon fractures.
Soft tissue damage
Results after open reduction and internal fixation of complex olecranon fractures
olecranon fractures (total)
ORIF: tension band wiring
ORIF: plate fixation
Results in patients with and without intermediate fragment
intermediate fragment (IF)
IF described in operative report:
IF not described in operative report:
ORIF: tension band wiring
ORIF: plate fixation
Secondary dislocation: 3/5 patients
Intraarticular positioned screw: 1/24 patients
Superficial infection: 2/29 patients
Heterotopic ossifications: 1/29 patients
In general, closed reduction techniques are not successful for anatomic reduction of the joint surface due to the entrapped intra-articular fracture fragments, especially the intermediate fragment. Various fixation techniques are utilized to restore the joint line and contour of the trochlear notch. Patients with tension band wiring require more frequently a second procedure for removal of symptomatic hardware than patients who underwent a plating procedure . Whereas in olecranon fractures without intermediate fragment figure-of-eight tension band wiring remains presently the "golden standard", it is obsolete in complex olecranon fractures. For stable fixation of these fractures we favour plate osteosynthesis (conventional plate contoured to the posterior surface of the proximal ulna or alternatively pre-contoured locking plate) with an additional intramedullary "home run" screw. Compared with pre-contoured plates conventional plates are more prominent on the olecranon, often difficult to adapt to the bent end of the olecranon, and probably in many fracture patterns not strong enough. Therefore pre-contoured plates are favoured.
As in studies published previously, we did not find in this observation sufficient differences in outcome using the PREE score between patients with posterior plate osteosynthesis and patients with figure-of-eight tension band wire fixation. Data provided in our study do not support that olecranon plating is generally beneficial in complex olecranon fractures with intermediate fragment compared to tension band wiring. Nevertheless, we would announce that utilization of the "home run" screw secures reduction of fracture fragments including alignment of the intermediate fragment to the trochlear face. In the operative report precise description of the fracture pattern including presence of an intermediate fragment is recommended.
Considering the pivotal role of the intermediate fragment in primary operative treatment of multi-fragmentary dislocated olecranon fractures we suggest to include the intermediate fragment into established classifications. In addition to existing classifications of olecranon fractures, the intermediate fragment should be recognized and mentioned separately.
Additional prospective studies with a long-time follow-up are necessary to assess and compare in a standardized way clinical and radiological outcome including detailed evaluation of the restored trochlear notch contour of the proximal ulna after primary operative treatment of olecranon fractures with intermediate fragment.
Written informed consent was obtained from the patient for publication of this report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
The corresponding author is indebted to Professor Otmar Trentz for his support and teaching as director of the Division of Trauma Surgery, University Hospital Zurich, in recent years.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.