Therapeutic implications of the radiographic "drop sign" following elbow dislocation

Posterior (Boyd) approach to terrible triad injuries

Background

A ‘terrible triad injury of the elbow’ (TTIE) refers to an injury pattern involving posterior dislocation of the ulnohumeral joint, fracture of the radial head, and fracture of the coronoid process of the ulna. It is a complex injury to the elbow joint and can result in long-term elbow instability, pain, stiffness, and arthritis. In specific cases, it may be treated conservatively, but in most circumstances, surgical stabilization is advised.

The ‘drop sign’ is an objective static radiographically measured ulnohumeral distance of ≥4 mm seen intraoperatively and postoperatively. Although controversial, it may portend postoperative instability and arthritis. The senior author repairs these injuries in a standardized fashion through a modified Boyd rather than a lateral approach. Our aim was to assess the number of cases demonstrating an intraoperative drop sign after surgical treatment of a TTIE with this approach.

Methods

We retrospectively analyzed 22 consecutive patients with 23 acute TTIEs. These injuries were treated by a single surgeon using a modified Boyd (posterior) approach to the elbow. Intraoperative image intensifier x-rays were analyzed by the two authors to assess for a ‘drop sign’.

Results

None of the 23 cases had ‘drop signs’ on intraoperative imaging after stabilization. No patient has redislocated, underwent reoperation, or had symptoms of instability at follow-up.

Conclusion

None of our patient cohort had an intraoperative ‘drop sign’ after standardized stabilization for a TTIE injury using a modified Boyd approach.

Rehabilitation of Elbow Instability

The elbow is the second most commonly dislocated major joint in adults with estimated incidence of 5 dislocations per 100,000 persons per year. A comprehensive understanding of elbow anatomy and biomechanics is essential to optimize rehabilitation of elbow injuries. This allows for implementation of a systematic therapy program that encourages early mobilization within a safe arc of motion while maintaining joint stability. To optimize outcomes, close communication between surgeon and therapist is necessary to allow for implementation of an individualized rehabilitation program. This article reviews key concepts that enable the clinician to apply an evidence-informed approach when managing elbow instability.

Fractures of the proximal ulna: current concepts in surgical management

Fractures of the proximal ulna range from simple olecranon fractures to complex Monteggia fractures or Monteggia-like lesions involving damage to stabilizing key structures of the elbow (i.e. coronoid process, radial head, collateral ligament complex).

In complex fracture patterns a computerized tomography scan is essential to properly assess the injury severity.

Exact preoperative planning for the surgical approach is vital to adequately address all fracture parts (base coronoid fragments first).

The management of olecranon fractures primarily comprises tension-band wiring in simple fractures as a valid treatment option, but modern plate techniques, especially in comminuted or osteoporotic fracture types, can reduce implant failure and potential implant-related soft tissue irritation.

For Monteggia injuries, the accurate anatomical restoration of ulnar alignment and dimensions is crucial to adjust the radiocapitellar joint.

Caution is advised if the anteromedial facet (anatomical insertion of the medial collateral ligament) of the coronoid process is affected, to avoid posteromedial instability.

Radial head reconstruction or replacement is essential in Monteggia-like lesions to restore normal elbow function.

The postoperative rehabilitation programme should involve active elbow motion exercises without limitations as early as possible following surgery to avoid joint stiffness.

Cite this article: EFORT Open Rev 2019;4:1-9. DOI: 10.1302/2058-5241.4.180022.

Surgical Technique for Arthroscopic Lateral Collateral Ligament Repair

Introduction

Arthroscopic repair of the lateral collateral ligament (LCL) complex in patients who have posterolateral rotatory instability after an unstable elbow dislocation, with or without an intra-articular fracture, is an alternative treatment for restoring stability of the elbow and obtaining successful clinical and radiographic results.

Indications & Contraindications

Step 1 Computed Tomography CT Magnetic Resonance Imaging MRI and Preoperative Planning

Obtain radiographs and CT and MRI scans to make an accurate analysis of the fracture patterns and develop an understanding of soft-tissue comorbidities.

Step 2 Position the Patient and Place the Portals

Place the patient in the lateral decubitus position and create proximal anteromedial, proximal anterolateral, anterolateral, and radial head portals as working portals and a posterior soft-spot portal as a viewing portal for the repair of the LCL complex.

Step 3 Diagnostic Arthroscopy

Identify concomitant radial head and coronoid fractures, and confirm the LCL-complex tear intraoperatively.

Step 4 Management of Concomitant Injuries

Treat intra-articular fractures arthroscopically before the LCL-complex repair.

Step 5 Arthroscopic LCL-Complex Repair Video 1

After soft-tissue debridement using the soft-spot portal as a viewing portal and the proximal anterolateral portal as a working portal, decorticate the footprint of the humeral attachment of the LCL complex with use of a shaver or burr and then make a modified Mason-Allen stitch using a needle, fixing the suture with a knotless anchor, to achieve a stable elbow joint.

Step 6 Postoperative Management

After postoperative immobilization of the elbow for 2 to 3 days, instruct the patient to perform passive exercises, returning to a full range of motion at 4 to 6 weeks after surgery, and typically returning to full activity at 3 months after the operation.

Results

To date, arthroscopic LCL-complex repair has produced excellent results, with all 13 patients in our original study reporting complete resolution of the elbow instability and demonstrating a negative result on the lateral pivot-shift test¹⁵.

Pitfalls & Challenges

Arthroscopic Lateral Collateral Ligament Repair

BACKGROUND

Lateral ulnar collateral ligament injury following unstable elbow dislocation can induce posterolateral rotatory instability that requires surgery. The aim of this study was to determine the effectiveness of arthroscopic repair of the lateral collateral ligament (LCL) complex in an unstable elbow joint.

METHODS

The study group consisted of 13 patients who experienced posterolateral rotatory instability after an unstable elbow dislocation with an injury to the lateral ulnar collateral ligament. The diagnosis was confirmed with computed tomography (CT), magnetic resonance imaging (MRI), and physical examination. The patients underwent arthroscopically assisted surgery between May 2011 and January 2013 and were followed for a minimum of 18 months postoperatively. Coronoid and/or radial head fractures combined with the ligament injury were treated through an arthroscopic technique. Range of motion, pain, outcomes according to the Mayo Elbow Performance Score (MEPS) and Nestor grading system, and surgical complications were evaluated. CT and MRI were performed at 3 months postoperatively, and isometric muscle strength was measured at the time of final follow-up.

RESULTS

At the time of final follow-up, at a minimum of 18 months, all 13 patients reported complete resolution of the instability and average (and standard deviation) extension of 3° ± 1°, flexion of 138° ± 6°, supination of 88° ± 5°, and pronation of 87° ± 6. The mean MEPS was 92 points and, according to this validated outcome score, the results were rated as excellent in 12 patients and good in 1 patient. According to the Nestor grading system, the results were rated as excellent in 11 patients and good in 2. Complete healing was seen on the 3-month follow-up MRI in 12 patients; however, 1 patient had mild widening of the radiocapitellar joint space with incomplete healing but no instability symptoms. All patients demonstrated normal strength on elbow flexion, extension, pronation, and supination at the final follow-up visit.

CONCLUSIONS

Arthroscopic repair of the LCL complex in patients with posterolateral rotatory instability after an unstable elbow dislocation, with or without an intra-articular fracture, is an alternative treatment option for restoring elbow stability and achieving satisfactory clinical and radiographic results.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Limited Medial and Lateral Approaches to Treat Stiff Elbows

Open arthrolysis is an effective way to treat elbow stiffness. However, previous approaches led to significant surgical trauma. The goal of the current study was to evaluate the outcome of open arthrolysis with limited medial and lateral approaches combined with hinged external fixation to treat elbow stiffness. A total of 18 patients (18 elbows) with elbow stiffness were retrospectively reviewed. The same inclusion and exclusion criteria were used for all patients. Preoperatively, the mean flexion arc was 43°±28° and the mean Mayo Elbow Performance Score was 62 points. Limited medial and lateral approaches were used to provide safe and complete arthrolysis. The other protocols included ulnar nerve transposition, medial epicondyle osteotomy, radial head resection, ligament repair, and hinged external fixation. Patients were encouraged to begin early rehabilitation 24 hours after surgery. At a mean follow-up of 20 months, the flexion arc improved to 130°±11° and the mean Mayo Elbow Performance Score was 97 points (15 excellent, 3 good). One patient had elbow instability, but function met the requirements of his daily life. Transient ulnar nerve palsy without infection occurred in 4 patients. With limited medial and lateral approaches, elbow stiffness can be treated effectively with open arthrolysis. This method is trauma controlled. Furthermore, a hinged external fixator can provide sufficient and safe rehabilitation. The use of open arthrolysis with limited medial and lateral approaches combined with hinged external fixation is an effective and safe method to treat elbow stiffness.

Arthrolysis combined with reconstruction for treatment of terrible triad injury with a poor outcome after surgical as well as conservative intervention

INTRODUCTION

The treatment of terrible triad injury with a poor outcome after intervention has not been successful thus far. The purpose of this study was to evaluate the efficacy of arthrolysis and reconstruction in the treatment of terrible triad injury with a poor outcome after surgical as well as conservative intervention.

MATERIALS AND METHODS

Twelve patients (12 elbows) with the diagnosis of terrible triad injury were respectively reviewed. All the 12 patients had elbow dysfunction after conservative and surgical treatment of the terrible triad injury. Preoperatively, the flexion arc and forearm rotation were 36.7° ± 28.5° and 51.3° ± 43.4°, respectively, and the Mayo Elbow Performance Score was 56.3 points. The mean interval between the primary injury and our surgical treatment was 6.6 months. Our surgical intervention included elbow arthrolysis, ulnar nerve transposition, radial head replacement, coronoid process and ligament repair, and hinged external fixation. Patients were encouraged to participate in rehabilitation training 24 h after surgery.

RESULTS

The mean follow-up duration was 20.1 months; the flexion arc and forearm rotation were 122° ± 18° and 140° ± 20°, respectively, and the mean Mayo Elbow Performance Score was 94.6 points (9 excellent, 3 good). Concentric stability was restored in all elbows. Complications included superficial pin tract infection (1), heterotopic ossification (3), and ulnar nerve palsy (1); the ulnar nerve symptoms had improved at the last follow-up.

CONCLUSIONS

The combination of open arthrolysis and reconstruction performed at a mean interval of 6-month posttrauma can restore functional mobility in cases of terrible triad injury with a poor outcome after surgical as well as conservative intervention. Thus, it may be an effective alternative for the treatment of the poor outcome terrible triad injury. We recommend early functional rehabilitation with adherence to the guidelines for hinged external fixation.