Critical analysis of triceps-reflecting anconeus pedicle (TRAP) approach for operative management of intra-articular distal humerus fractures

In the operative management of intra-articular distal humerus fractures, optimal approach that not only allows good visualization and stable fixation of the entire fracture geometry but also affords aggressive postoperative elbow rehabilitation with minimal complications is critical to achieve a consistently good results in these challenging fractures. Though numerous approaches have been described in the literature, namely Bryan Morrey triceps reflecting, Triceps splitting, paratricipital, triceps reflecting anconeus pedicle (TRAP) and olecranon osteotomy; there is no agreement on ideal approach for these fractures with minimal complications. Hence we envisaged to conduct a study on the critical analysis of TRAP approach for the management of intra-articular AO type C distal humerus fractures with the purpose of studying the feasibility of the approach in affording adequate exposure and fixation of the entire fracture geometry and allowing aggressive postoperative elbow rehabilitation. We also report our short term clinical, functional and radiological outcome using this approach in AO type C distal humerus fractures.Fifteen cases (age group 16-57 years; mean 31.8 years) with AO type C fractures, < 1 month old, were treated using TRAP approach and principle based parallel plating technique as described by O'Driscoll. Eleven fractures were AO type C3; 3 were C2 and one was C1. Grade 2 or more open fractures, pathological fractures, fractures with open physis and associated vascular injuries were excluded. The mean interval between injury and surgery was 7 days (range 3-26 days). Cases with a minimum follow-up of 6 months (range 9-14 months) were included in the final analysis. All cases were mobilized after postoperative day 3 on the heels of pain with active assisted elbow flexion and passive elbow extension 6 weeks after which splint was discarded. The patients have been assessed clinically with use of the Mayo Elbow Performance Score (MEPS) and radiographically.All fractures united without loss of fixation, fracture displacement, hardware failure or bone grafting. One postoperative ulnar nerve palsies that was surgically explored recovered partially subsequently. Two superficial infections responded to surgical debridement and had final excellent outcome. Wound complications not requiring secondary surgical procedures like postoperative hematoma, superficial skin dehiscence and necrosis over tip of olecranon was seen in 4 cases that eventually healed uneventfully. Heterotopic ossification was seen in 2 cases (1 each of Brooker grade 3 and 1). Three cases had clinically evident (MRC grade 3 or less) triceps weakness. One case needed retightening of 1 distal screw following backout (MEPS 90). The mean MEPS was 85 points. Six cases have excellent, 4 cases had good and 5 cases have fair outcome.TRAP approach allows adequate fracture visualization and stable fracture fixation even in comminuted AO type C3 fracture of the distal humerus, with the advantage of intact olecranon that does serve as a template around which critical intra-articular fracture reduction is afforded. The approach permits aggressive postoperative elbow rehabilitation without elbow instability. However, wound related complications and residual triceps weakness may be of concern in some cases. Accurate and strong reattachment of the reflected extensor mechanism is absolutely critical for postoperative elbow rehabilitation and good functional outcome.