Complications of Treating Terrible Triad Injury of the Elbow: A Systematic Review

Objective Terrible triad injury of the elbow (TTIE), comprising elbow dislocation with radial head and coronoid process fracture, is notoriously challenging to treat and has typically been associated with complications and poor outcomes. The objective of this systematic review was to summarize the most recent available evidence regarding functional outcomes and complications following surgical management of TTIE. Methods Medline, EMBASE, Cochrane Library, and Google Scholar were searched to identify relevant studies, which were included if they were retrospective or prospective in design, involved participants who had TTIE, and were published in English. Outcomes of interest were functional outcomes and complications. Results Sixteen studies, involving 312 patients, were included in the systematic review. Mean follow up after surgery was typically 25 to 30 months. Mean Mayo elbow performance scores ranged from 78 to 95. Mean Broberg-Morrey scores ranged from 76 to 90. Mean DASH scores ranged from 9 to 31. The proportion of patients who required reoperation due to complications ranged from 0 to 54.5% (overall  = 70/312 [22.4%]). Most of these complications were related to hardware fixation problems, joint stiffness, joint instability, and ulnar neuropathy. The most common complications that did not require reoperation were heterotopic ossification (39/312 [12.5%] patients) and arthrosis (35/312 [11.2%] patients). Conclusions The results of this systematic review indicate that functional outcomes after surgery for TTIE are generally satisfactory and that complications are common. Further research is warranted to determine which surgical techniques optimize functional outcomes and reduce the risk of complications.


Introduction
The combination of elbow dislocation with both radial head and coronoid process fracture is notoriously challenging to treat and, as such, has been termed ''terrible triad'' injury of the elbow (TTIE) [1]. This type of elbow injury is typically due to low or high energy falls onto an outstretched hand, which results in valgus and axial compression of the supinated forearm [2]. This leads to failure of the lateral collateral ligament complex (the medial collateral ligament may also fail), dislocation of the elbow, and consequent fracture of the radial head and coronoid process [2,3]. As a result of these injuries, the elbow is left in an unstable state that invariably requires surgical intervention. Unfortunately, due to the complexity of injury, outcomes have traditionally been poor, with long-term complications including stiffness, pain, arthritis, and joint instability [4].
The aim of surgery in managing TTIE is the restoration of stability of the humeroulnar and humeroradial joints, thus facilitating early postoperative elbow motion to reduce the likelihood of long-term joint stiffness or disability [3,5]. Clearly, to optimize the chances of success, such surgery must adequately account for all three injury components of the terrible triad [3]. Over the years various reports have described surgical management of these fractures, with there being differences in the surgical approach used, the means of fixation, and the type of implant used in cases requiring replacement arthroplasty of the radial head [2,3]. To date, however, there is no consensus as to the optimal means of surgical management. In 2011, Rodriguez-Martin and colleagues [6] published the results of a systematic review summarizing injuring patterns, treatment, and outcomes (including complications) in patients with TTIE. On the basis of findings from five studies included in the review (all published before 2009), the authors made a number of recommendations regarding the management of TTIE. Since publication of Rodriguez-Martin's [6] article, the findings from a considerable number of additional studies on this topic have been published. Such studies clearly reflect the most current treatment practices. As a consequence, we decided to perform a systematic review of the literature to gain a more comprehensive understanding of complications and functional outcomes in patients with TTIE following surgical repair.

Search Strategy
Medline, EMBASE, Cochrane Library, and Google Scholar were searched on 31 July 2013 using combinations of the following search terms: elbow triad terrible, coronoid fracture, radial fracture, elbow fracture, and elbow dislocation.

Study Selection
Studies were considered for inclusion in the review if they involved participants who met the criteria for TTIE (i.e., elbow dislocation, radial head fracture, and coronoid process fracture), and were published in English. Studies were excluded from the review if they included patients with injuries other than TTIE or if they were published in the form of letters, comments, editorials, or case reports. References lists of pertinent articles were hand searched to identify other potentially relevant studies.

Data Extraction
Data were extracted by two independent reviewers who consulted with a third reviewer to resolve any disagreements. The following data/information were extracted from each eligible study: author details, number, sex, and age of patients, length of follow up, Mason classification for radial head fractures [7], Regan-Morrey classification for coronoid fractures [8], functional outcomes (Mayo elbow performance scores [1], Broberg-Morrey scores [9], and Disabilities of the Arm, Shoulder and Hand (DASH) scores [10]), and any complications.

Outcome Measures
The outcomes measures of interest were functional outcomes and complications.

Study Characteristics
The main characteristics of the studies included in the systematic review are summarized in Table 1. All studies, except for that reported by Zeiders and Patel [15], were retrospective in design. The number of patients in the studies ranged from 6 to 40 (total = 312). Most (13 of 16) studies reporting information on patient sex included a majority (.50%) of male patients. Most studies reported that the mean age of patients was 40 to 49 years. The mean length of follow up ranged from 13.6 to 64 months, although 25 to 30 months follow up was most common.

Functional Outcomes
8 of 16 studies included assessment of Mayo elbow performance scores, which ranged (mean) from 78 to 95 (Table 2). Two studies [21,23] reported that mean scores excellent, whereas mean scores in the remainder of the studies were good. Overall, for the studies reporting individual patient results (N = 155 patients), 61 (39%) patients had excellent scores, 66 (43%) had good scores, 23 (15%) had fair scores, and 5 (3%) had poor scores. 7 of 16 studies included assessment of Broberg-Morrey Scores, which ranged (mean) from 76 to 90. Two studies [22,25] reported that mean scores excellent, whereas mean scores in the remainder of the studies were good. Overall, for the studies reporting individual patient results (N = 98 patients), 27 (28%) patients had excellent scores, 39 (40%) had good scores, 24 (24%) had fair scores, and 8 (8%) had poor scores. 8 of 16 studies reported DASH scores, which ranged (mean) from 9 to 31.

Complications
The complications reported in the studies included in the systematic review are summarized in Table 3. The proportion of patients who required reoperation ranged from 0 to 54.5%, with most studies reporting that approximately 30% of patients experienced the need for reoperation. No patients required reoperation in 3 studies [15,16,23]. Overall, 70 of 312 (22.4%) patients experienced complications requiring reoperation. Complications requiring reoperation were typically because of problems related to hardware/fixation, joint stiffness, joint instability, or ulnar neuropathy. There were few instances of wound infection. The following is a brief summary of the results from studies in which .1 patient experienced the same complication. Leigh et al. [24] reported that 2 of 23 (8.7%) patients experienced symptomatic nonunion of the radial head and neck or were unable to regain a functional range of motion despite .6 months of rehabilitation. Garrigues et al. [22] reported that 3 of 40 (7.5%) patients experienced limited flexion, residual instability, or had an oversized radial prosthesis. Seijas et al. [18] reported that 3 of 18 (16.7%) experienced dislocation and that 2 of 18 (11.1%) patients experienced Essex-Lopresti lesions. Winter et al. [17] reported that 2 of 13 (15.4%) patients experienced a lack of appropriate physiotherapy necessitating lateral arthrolysis. Lindehovius et al. [25] reported that 2 of 18 (11.1%) patients experienced joint stiffness or ulnar neuropathy. Forthman et al. [26] reported that 4 of 22 (18.2%) patients experienced ulnar neuropathy and that 3 of 22 (13.6%) patients experienced joint stiffness. Egol et al. [14] reported that 2 of 37 (5.4%) patients experienced joint stiffness. Pugh et al. [12] reported that 4 of 36 (11.1%) patients experienced limited range of motion and that 2 of 36 (5.6%) patients experienced radioulnar synostosis. Ring et al. [11] reported that 5 of 11 (45.4%) patients experienced redislocation.
The most common complications that did not require reoperation were heterotopic ossification (reported by 39 of 312 [12.5%]

Discussion
In this systematic review, we examined functional outcomes and complications after surgical repair of TTIE. A total of 16 studies, almost exclusively retrospective in design, involving more than 300 patients were found to be eligible for inclusion in our review.
Overall, functional outcomes were satisfactory, whereas complications (including both those requiring reoperation and those not requiring reoperation) were relatively common.
We found that functional outcomes, as determined by assessing Mayo elbow performance, Broberg-Murray, and/or DASH scores were consistently satisfactory. Indeed, with regards to Mayo elbow performance and Broberg-Murray scores, approximately 70% or more of patients had good to excellent scores. Further, less than 10% of patients had poor scores. The findings of our systematic review are consistent with those of an earlier systematic review of studies published before 2009, in which the majority of Mayo elbow performance and Broberg-Murray scores were excellent or good [6]. Hence, application of current surgical strategies/ technology would appear to have maintained, rather than  increased, the proportion of patients experiencing positive outcomes after management of TTIE. Further refinement of surgical/ management strategies in the future will hopefully decrease the proportion of patients who experience fair or poor outcomes. Although a relatively high proportion of patients had satisfactory functional outcomes, many patients experienced complications, including ulnar neuropathy, elbow joint stiffness, heterotopic ossification, and arthrosis. Indeed, overall, slightly less than onethird of patients required reoperation due to complication(s), typically due to instability or stiffness-related problems. There was no clear chronological trend in the occurrence of complications i.e., the rate of complications did not obviously decrease with time/presumable advances in management strategies/technology. This is despite the publication of an algorithm for the surgical management of TTIE and excellent review on the topic by Mathew et al. in 2009 [2]. Interestingly, 3 studies did not report that any patients required reoperation for the management of complications [15,16,23]. Two of these studies [16,23], however, included a small number (#16) of patients. The other study, reported by Zeiders and Patel [15] involved 32 patients who were operated on following preoperative planning using three-dimensional computerized tomographic reconstruction and use of a treatment algorithm. Several patients in this study experienced heterotopic ossification; however, there was no mention of any complications requiring reoperation. This is unusual for a study involving a relatively (for this injury) large number of patients. In general, the continuing high rate of complications experienced by patients after surgical management of TTIE is concerning and signifies that further refinement of surgical approaches and preoperative and postoperative management are needed.
Our systematic review has several limitations that should be considered when interpreting the findings. Firstly, all except for 1 study [15] were retrospective in design. As such, the overall strength of evidence from these studies is not of the highest quality. Evidence from additional prospective studies would be welcome. Secondly, although our review included a relatively large number of studies (N = 16), the overall number of patients was not particularly high at just over 300. Although results from larger scale studies would provide more definitive evidence, such studies are unlikely to occur because terrible triad injuries of the elbow are not sufficiently common. Finally, the studies included in our review lacked homogeneity in a number of areas. Surgical approaches and management varied between studies, as did type of radial head and coronoid fractures, and the length of follow up. These differences may have affected both functional outcomes and complications to some extent. We must emphasize, however, that despite the lack of homogeneity, the overall results were quite compelling in that functional outcomes were consistently satisfactory for most patients and that complications were common.
In summary, the results of this systematic review indicate that most patients experience satisfactory functional outcomes following surgery for TTIE. Unfortunately, a relatively high proportion of patients continue to experience complications after surgery that often requires reoperation. Further refinements in surgical techniques and pre and postoperative management are needed to reduce complications.