The mechanism of injury is important determinant of the terrible triad. Mechanism this complex injury can be explained by the following sequence of events. The patient straightened the elbows with forearm supination when he fell from standing height. The axial force transmitted to the ulnohumeral joint contributed to posterior dislocation and led to the radial head and coronoid fractures. In this case, the patient touched the ground first on right side with excessive abduction of the elbow, and the valgus stress drove the fragments of the radial head to the ulnar side and probably caused the MCL injury simultaneously. As initial impact was more on right side that explains more comminution of radial head on right as compared to left elbow. The purposes of treatment of terrible triad injury is to recover the congruency of the elbow joint, restore stability, and allow early joint mobility of the elbow to avoid complications.[3] Both the standard protocols proposed by Pugh et al. for treating the terrible triad of the elbow have consists of restoration of the anatomical structure of humeroradial joint, Reduction and fixation of the coronoid process fracture, Repaired or restoration of joint capsular injuries to the lateral stability of the LCL complex and repairing the MCL when needed.
There are various approaches have been reported to treat the terrible triad of the elbow. We chose a combination of lateral (Kocher approach) and anteromedial approaches, which is less traumatic, more effective for fracture exposure and more directly to check the capsuloligamentous structures. On Radial head is important in giving posterolateral stability of elbow joint. In literature it is suggested that mason type 2 radial head fracture when fixed gives better functional outcome compared to arthroplasty. [4] Therefore, we decided to fix radial head with two Herbert screw to prevent soft tissue irritation because of implant and to give more rigid fixation. But at the same time controversy remains for minimally displaced and small fragment of radial head. Fixation of small fragment remains challenge due to shattering of fragment while passing screw, back-out of implant because of joint forces. Radial head fracture fragment also dictates mode of treatment, as in our case radio-ulnar articulation was not affected, small anterior portion of radial head was excised as it involved difficult to fix. Terrible triad injuries have bone as well as soft tissue component. Soft tissue repair is important to give stability to elbow, MCL and LCL repair is important to stabilize joint and allow functional recovery. [5] A gradual rehabilitation protocol makes sure reasonable elbow range of motion can be achieved and patient returns to functional activity as early as possible. As injury was severe on right side, range of motion was observed less as compared to left. This can be attributed to various factors ranging from soft tissue component to radial head comminution on right side. The most common complication after terrible triad injury is stiffness, in our patient we observed same. Additionally, we did not observe any complication with screw fixation of the radial head fracture that reported in the literature such as loss of forearm rotation, nonunion, and implantation failure.
We report a rare case of bilateral terrible triad of the elbow joints with uncommon mode of injury and treated with different protocols on each side. The combination of 3 D- CT scan study, bio-mechanics and anatomy of fracture fragment dictates surgical plan. The individualized fixation plan along with combination of lateral and anteromedial approaches is a reliable method for the management and good functional outcome can be obtained in such complex rare injuries.