Internal Joint Stabilizer: A Safe Treatment for Traumatic Elbow Instability

Management of Elbow Terrible Triad Injuries: A Comprehensive Review and Update

The "terrible triad" of the elbow, encompassing elbow dislocation, radial head fracture, and coronoid process fracture, remains a formidable challenge in orthopaedic practice. Typically, stabilizing structures in the elbow fail from lateral to medial through a posterolateral rotatory force after a fall onto an outstretched upper extremity. Surgery is often needed to repair the lateral ligamentous complex, replace or fix the radial head, possibly repair the anterior capsule or fix the coronoid, and consider medial repair or application of an internal versus external fixator. However, in some challenging cases persistent instability, complications, and loss of function may occur. Rehabilitation focuses on achieving early range of motion to prevent stiffness which can be common after these injuries. By integrating emerging approaches with established practices, this article aims to guide orthopaedic surgeons toward a fundamental understanding of terrible triad injuries and assist with informed management principles of these complex injuries.

Ulnohumeral Cross-Pinning in the Management of Traumatic Elbow Instability

PURPOSE

Traumatic elbow instability (subluxation and dislocation) represents a challenging clinical entity that can be complicated by persistent intraoperative instability after attempted stabilization or recurrent postoperative instability. Both static and dynamic supplemental stabilization procedures have been described for cases where fracture fixation and ligament repair fail to restore stability. There is a paucity of prior studies involving ulnohumeral cross-pinning (UCP), which is a type of static supplemental stabilization. Our purpose was to assess complications and outcomes after UCP.

METHODS

We reviewed all surgical cases involving primary and revision UCP for traumatic elbow instability at a single center from 2017-2023. Baseline demographics were recorded. Outcomes including radiographs, range of motion, patient-reported outcome measures, and surgical complications were analyzed.

RESULTS

Fourteen patients undergoing UCP were included with a mean follow-up of 27 months. Five cross-pinnings (36%) were performed during revision procedures. Mean visual analog scale (VAS) pain, Disabilities of the Arm, Shoulder, and Hand (QuickDASH), and the Single Assessment Numeric Evaluation (SANE) scores were 2.4, 34, and 69, respectively. The mean flexion-extension and pronation-supination arcs were 114° and 140°, with 85% achieving at least a 100° arc for flexion and forearm rotation. Five patients (36%) had complications, all of which required reoperation. Two complications involved postoperative instability: one radial head subluxation and one radial head dislocation. Both occurred in revision UCP cases indicated for recurrent postoperative instability.

CONCLUSIONS

Ulnohumeral cross-pinning for persistent and recurrent elbow instability results in maintained ulnohumeral joint alignment, functional arcs of elbow range of motion, and acceptable patient-reported outcome measures, particularly in the setting of a primary procedure indicated for persistent intraoperative instability. Ulnohumeral cross-pinning is a reasonable supplemental stabilization procedure for complex elbow instability.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The internal joint stabilizer for elbow instability: current concepts

The management of residual elbow instability is challenging in both acute and chronic injuries. Among the available devices, the hinged external fixator provides an additional joint stabilization while allowing an early motion, but it is clumsy and associated to high rate of pin track complications. To address these issues, an internal joint stabilizer (IJS) has been recently developed. An easier recreation of the axis of rotation coupled to the reduced lever arm of the hinge is the root of the consistent and satisfactory results thus far observed. In addition, the device is more comfortable for the patients being an internal stabilizer. Nonetheless, a second surgery for the device removal is necessary, of which the timing is still not standardized. This current concepts paper describes literature regarding outcomes of the IJS focusing on the rate of maintained radiographic joint reduction, the resultant range of motion, and the associated complication profile.

Comparing internal and external stabilization for traumatic elbow instability: a systematic review

Background

Despite surgical reestablishment of the supporting structures, instability may often persist in traumatic elbow injury. In these cases, a temporary internal or external fixator may be indicated to unload the repaired structures and maintain joint concentricity. Aggregate data are needed to characterize the risk of complication between external fixation (ExFix) and the internal joint stabilizer (IJS) when used for traumatic elbow instability. Our objective was to review the literature to compare the complication profile between external fixation and the IJS.

Methods

A database query was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Population, Intervention, Comparison and Outcome characteristics for eligibility were the following: for patients over 18 years clinical outcomes were compared between an ExFix or the IJS for acute or chronic elbow instability. The Cochran risk of bias in nonrandomized studies of interventions and grades of recommendation, assessment, development, and evaluation framework were compiled for risk of bias and quality assessment.

Results

The rate of recurrent instability was 4.1% in the IJS group (N = 171) and 7.0% in the ExFix group (N = 435), with an odds ratio of 1.93 (95% confidence interval 0.88-4.23). The rate of device failure was 4.4% in the IJS group and 4.1% in the ExFix group. Pin-related complications occurred in 14.6% of ExFix cases. Complications in the IJS group were the following: 1 case of inflammatory reaction, 4 cases of post removal surgical site infection, and 5 symptomatic removals.

Discussion

The literature demonstrates a distinct difference in complication profile between external fixation and the IJS when used as treatment for traumatic elbow instability. Although not statistically significant, the higher rate of recurrent instability following external fixation may be clinically important. The high rate of pin-related complications with external fixation is notable.

The Internal Joint Stabilizer of the Elbow: A Systematic Review of the Clinical and Biomechanical Evidence

Purpose

The goal of surgical management for unstable elbow injuries is the restoration of joint concentricity and stability. After internal fixation, concerns may exist regarding instability or durability of the fixation construct. Historically, these scenarios were treated with options such as transarticular pinning or external fixation. Recently, an internal joint stabilizer (IJS) that allows postoperative mobilization was introduced. Our objective was to systematically review the literature to aggregate the clinical and biomechanical evidence for the IJS of the elbow.

Methods

A systematic review of the PubMed and Google Scholar databases was performed, following the PRISMA guidelines. The search results were narrowed from 2015 through 2023 to coincide with the inception of the device being reviewed.

Results

A total of nine retrospective reports on the IJS (N = 171) cases at a mean follow-up of 10.8 months were included. The pooled rate of implant failure was 4.4%, and recurrent instability was 4.1%. Additionally, the we included seven case reports and two biomechanical reports.

Conclusions

The aggregate literature describes satisfactory clinical outcomes with low rates of recurrent instability and device failure for the IJS of the elbow. The limited biomechanical investigations conclude efficacy for stability profiles.

Clinical relevance

Across a spectrum of unstable elbow cases, the IJS prevented recurrent instability during the early postoperative period. Notably, the device requires an additional procedure for removal, and the long-term impact of the retained devices is currently unclear.

Improved Understanding of Traumatic Complex Elbow Instability

Recent advancements in surgical treatment have improved clinical results in complex traumatic elbow injury. There is increasing recognition that conservative treatment and inadequate surgical fixation carry high risk of substantial morbidity in many of these cases. Recent literature displays improved outcomes in complex elbow instability, in part, because of a more complete comprehension of the injury patterns and fixation methods. Prompt surgical management with stable internal fixation, which permits immediate postoperative mobilization, has been a consistent variable across the reports leading to more satisfactory outcomes. This applies to both acute and chronic cases.