RECONSTRUCTION OF DELAYED UNION AND NONUNION OF THE PROXIMAL ULNA AND OLECRANON
Chaitanya S. Mudgal, MD, and Jesse B. Jupiter, MD
Delayed and / or nonunion of the proximal ulna and the olecranon is extremely uncommon. However, the degree of upper limb dysfunction can be profound. Nonunion has been identified in 5 per cent of all olecranon fractures.
Delayed or nonunion of the proximal ulna and olecranon can limit elbow mobility resulting in inhibition of the ability of the upper limb to place the hand within the volume of a sphere in space. Since the volume of a sphere is proportional to the cube of its radius, any loss of elbow motion leads to a significant loss of reach of the hand.
A fracture of the proximal ulna should be considered to be ununited if there has been no radiographic evidence of union after 6 months. The presence of a displaced or angulated fracture with no clinical or radiographic signs of union with or without the presence of loose or failed hardware, constitutes a nonunion. A delayed union may be considered if there has been some early attempts at union which then seem to have plateaued or the radiographic progress of union is not commensurate with the time period since the fracture.
Irrespective of the definitions of each of these terms, it is optimal to identify a delay in healing and prevent it from developing into a well defined nonunion. The management of a delayed union is similar in numerous aspects to the management of nonunion in this location and as such, these two entities are addressed as one.
A nonunion in this location is often associated with pain, stiffness affecting both the ulnohumeral and forearm articulations, and occasionally instability of the ulnohumeral joint.
Infection should also be considered as a cause of nonunion. The multiply operated elbow increases the risk of underlying infection and this will need to be addressed aggressively, if union is to be achieved.
A stable painfree elbow and forearm are vastly superior to an arthroplasty and every effort should be made to achieve union, when possible. While there is no chronological age demarcation in the decision making process, alternative methods of management may be considered in the elderly.
In patients who have a dysfunctional upper limb due an olecranon or proximal ulnar nonunion, reconstruction with osteosynthesis should be considered, provided they are able to comprehend and follow the treatment and rehabilitation process, have a sensate hand, and functioning motors of adequate strength about the elbow.
The primary goal of reconstructive surgery is both, achievement of bony union as well as restoration of a functional range of motion. The requirements to achieve these goals will be a stable, pain-free, concentric elbow, with congruous articular surfaces, and an intact functioning extensor mechanism and soft tissue envelope.
In the decision making process, several factors play an important role. These are called the ‘critical factors’ and include (a) symptoms, (b) the physiologic age of the patient, (c) the functional abilities and demands of both the patient as well as the affected upper limb, (d) the condition of the soft tissue envelope and extensor mechanism, (e) the size and condition of the proximal fragment as well as the condition of any existing implants, (f) the condition of the articular surface especially following comminuted articular fractures, (g) co-existent problems which may need to be addressed at the time of the reconstruction such as heterotopic ossification, radio-ulnar synostosis, and stiffness and finally (h) the presence of infection. The presence of infection or a poor soft tissue envelope or both may require multiple procedures prior to undertaking a formal bony reconstruction.
This paper outlines the rationale, clinical approach and surgical tactic for the management of proximal ulnar and olecranon nonunions.