The contribution of the posterolateral capsule to elbow joint stability: a cadaveric biomechanical investigation

Open Posterolateral Ligament Plication and Lateral Ulnar Collateral Ligament Repair in Posterolateral Rotatory Instability of the Elbow Using an All-Suture Construct

Posterolateral rotatory instability of the elbow is the most common form of lateral-sided instability; it is often the result of an injury to the lateral collateral ligament complex involving the lateral ulnar collateral ligament. Recently, the posterolateral capsule of the elbow has been recognized to play a major role in preventing posterolateral rotatory instability, identifying it as an independent ligament of the lateral complex (posterolateral ligament). We present our technique for posterolateral elbow stabilization through plication of the posterolateral ligament associated with repair of the lateral ulnar collateral ligament using an all-suture anchor.

Anconeus Exertional Compartment Syndrome and Posterolateral Rotatory Elbow Instability: A Clinical Association and Rare Cause of Elbow Pain

Background

Anconeus compartment syndrome is a rarely reported compartment syndrome in the anconeus muscle compartment of the forearm. It has anatomic and pathophysiological associations with posterolateral rotatory instability (PLRI) of the elbow.

Purpose

To present the history, management, and outcomes of 4 patients with anconeus compartment syndrome. Secondary aims were to (1) establish normative anconeus pressures and (2) measure the volume of this compartment with and without PLRI in cadavers.

Study Design

Case series; Level of evidence, 4.

Methods

Four patients with clinical signs of anconeus compartment syndrome (2 gymnasts, 1 swimmer, and 1 footballer/weightlifter) were identified over a 3-year period (2015-2017 inclusive). Patient history, sporting activity, physical examination, anconeus compartment pressures, and treatment outcomes were recorded. Manometry of the anconeus compartment in 2 healthy male controls was performed to establish normative compartment pressures. Anconeus volumetric anatomy and the effect of creating PLRI on compartment volume was investigated in 4 cadaveric elbows.

Results

All 4 patients had microtraumatic PLRI, and 2 patients had anconeus hypertrophy. Anconeus compartment pressures at rest and at 2-minutes postexercise were median 28.0 and 67.5 mm Hg, respectively, in the patients and mean 16.5 and 18 mm Hg, respectively, in the controls. Simultaneous fasciotomy and PLRI reconstructive procedures were performed in 2 patients, with outcomes showing full return to competition. Fasciotomy alone was performed in 2 patients to allow return to competition, with both requiring later reconstruction to address PLRI. Cadaver dissection revealed that the anconeus compartment was extremely small and that creation of PLRI reduced the direct volume of the compartment and increased the distance between the anconeus origin and insertion.

Conclusion

Our case series demonstrated that anconeus compartment syndrome can occur in upper limb-dominant athletes in the presence of PLRI and anconeus hypertrophy. Pain is relieved by fasciotomy, but definitive treatment of the underlying instability prevents further symptomatology.

Look for the POLESTAR (POsteroLateral Engagement of Soft Tissue And Radial head) while navigating around elbow dislocation

BACKGROUND

Elbow dislocation is frequently associated with bony and osteochondral posterolateral capitellar lesions that are often under-reported. We aim to examine the radiologic signs of posterolateral lesions on computed tomography (CT).

METHODS

A retrospective analysis of CT scans was performed. Patients were classified into 4 groups: (1) simple elbow dislocation, (2) elbow dislocation with a fracture of the coronoid tip, (3) elbow dislocation with coronoid tip fracture and a radial head fracture inferior or equal to the anterior third, and (4) terrible triad defined as elbow dislocation with concomitant coronoid and radial head fracture with a more important involvement. Patients with a more complex fracture pattern were excluded. The presence of POsteroLateral Engagement of Soft Tissue And Radial head (POLESTAR) patterns was analyzed and subclassified as impaction type or fragmentation type.

RESULTS

Fifty-one CT scans met the inclusion criteria. POLESTAR lesions were identified in 48 cases (94%): 46% impaction-type and 54% fragmentation-type POLESTAR. Analyzing patients from grade 1 to 4, impaction-type POLESTAR was found, respectively, from 40% to 57%, whereas fragmentation type was present from 60% to 43%.

CONCLUSIONS

This study shows a high incidence of POLESTAR lesions (94%) that can be present as impaction type or fragmentation type. Based on our preliminary results, impaction type is more common in grades 3 and 4, whereas fragmentation type is more frequent in grades 1 and 2.

The posterolateral ligament of the elbow: anatomy and clinical relevance

BACKGROUND

The posterolateral capsule was recognized in the past as an important structure for elbow stability but was later disregarded. Two recent biomechanical studies demonstrated its role in preventing posterolateral instability, and thus it should be identified as a distinct ligament: the posterolateral ligament (PLL). This study includes 2 parts: an anatomic study of the PLL's footprint and a collection of 5 cases of pathologic lesions of the PLL.

METHODS

Six cadaveric upper limbs were assessed. The attachments of the PLL were dissected, the footprints were marked and photographed, and the 2-dimensional area and length were measured.

RESULTS

The mean proximal attachment dimensions were a length of 13 mm and an area of 101 mm2, and the mean distal attachment dimensions were 19 mm and 111 mm2, respectively. There were 2 cases of posterolateral elbow pain in professional cricket bowlers, diagnosed radiographically as enthesopathy of the PLL's proximal attachment on the posterior capitellum, probably due to repeated forced hyperextension of the elbow. Both patients were treated by débridement of the posterior capitellum and reattachment of the PLL, with complete resolution of symptoms. In addition, there were 3 cases of clinical posterolateral rotatory instability in young patients. Two athletes had an isolated acute tear of the PLL, and on physical examination, both had positive posterior draw test results but negative pivot-shift test results. Both underwent elbow arthroscopy and repair of the PLL with resolution of symptoms. The third patient had long-standing recurrent elbow instability, following a failed lateral ulnar collateral ligament reconstruction, in the presence of an Osborne-Cotterill lesion. He underwent revision lateral ulnar collateral ligament reconstruction, bone grafting of the bony lesion, and reattachment of the PLL, with complete resolution of symptomatic posterolateral rotatory instability.

CONCLUSIONS

The PLL of the elbow has a significant role in the elbow's posterolateral stability. Its footprints were described, and its clinical significance was demonstrated in cases of elbow instability caused by acute ligament tears and elbow pain due to ligament enthesopathy. Surgeons should be aware of this structure and potential pathology related to its injury.

Evaluation of Surgical Approaches to Management of Traumatic Posteromedial Elbow Instability Syndrome: A Systematic Literature Review Protocol

Posteromedial Instability Syndrome of the Elbow (PMIE) is a condition that arises from injuries to the stabilizing structures of the elbow joint, such as the coronoid process or ulnar lateral collateral ligament. Surgical treatment is commonly performed, but there is uncertainty regarding its results. This systematic review will synthesise the available evidence regarding the efficacy of surgical approaches to PMIE. Published and unpublished primary studies that regard outcomes of patients treated for PMIE, irrespective of approach, will be considered for inclusion. Iterative searches will be performed in the PubMed/MEDLINE, EMBASE, and Cochrane CENTRAL repositories from their inception to May 2023. Grey literature repositories will also be searched. The Cochrane risk of bias tool will be used to assess the quality of eligible interventional studies, while the MINORS tool will be employed for observational studies. If possible, a meta-analysis based on the random-effects model will be conducted. Heterogeneity will be assessed using Cochrane's Q and I2 statistics, and explored through subgroup analyses and sensitivity analyses. Relevant outcomes will include elbow joint functionality as assessed by validated scales, the proportion of patients returning to usual daily life activities, the development of recurrent joint instability in the postoperative period, quality of life and the development of postoperative arthritis. This protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the University of York. Its registration number is CRD42023451516.

Current concepts in the management of "Terrible Triad" injuries of the elbow

Terrible triad injuries of the elbow are complex injuries which can result in long term complications and significant disability. They must be identified correctly, and managed appropriately in order to maximise functional outcomes. A clear understanding of the bony and ligamentous anatomy is essential to plan appropriate surgical reconstruction to provide elbow stability. Urgent reduction of the elbow, followed by 3-dimensional imaging and surgical repair or replacement of the injured structures is the mainstay of treatment in the majority of cases. This review presents a summary of the relevant anatomy and the evidence for the management of these complex injuries.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Elbow

ABSTRACT

In this dynamic protocol, ultrasound examination of the elbow using different maneuvers is described for several/relevant elbow problems. Scanning videos are coupled with real-time patient examination videos for better understanding. The authors believe that this practical guide-prepared by an international consensus of several experts (EURO-MUSCULUS: European Musculoskeletal Ultrasound Study Group and USPRM: Ultrasound Study Group of ISPRM [International Society of Physical and Rehabilitation Medicine])-will help musculoskeletal physicians perform a better and uniform/standard approach.

The radiological findings in complex elbow fracture-dislocation injuries

Elbow fracture-dislocation is a complex injury which can lead to significant bony and soft tissue damage. Surgical intervention is guided towards restoring joint stability, allowing early mobilization and preventing long-term joint stiffness. The most common types are posterolateral, posteromedial, Monteggia type (and variants), and anterior trans-olecranon fracture-dislocations. Posterolateral fracture-dislocation is characterized by a radial head fracture (± anterolateral coronoid fracture) and typically capsuloligamentous disruption (lateral collateral ligaments injury is the most common). A posterolateral fracture-dislocation with radial head and coronoid anterolateral facet fractures is termed a terrible triad injury. In posteromedial fracture-dislocation, there is a fracture of the anteromedial facet of the coronoid, typically with proximal avulsion of the lateral collateral ligaments (± injury to the posterior bundle of the ulnar collateral ligament). Monteggia fracture-dislocation injuries demonstrate proximal ulnar fracture (with possible involvement of the olecranon and the coronoid) and radial head dislocation. These can be divided into apex anterior or apex posterior variants. The latter are commonly associated with radial head fractures and lateral ligamentous injury, and have a worse prognosis. In trans-olecranon fracture-dislocation, there is significant disruption of the greater sigmoid notch and the olecranon, with various involvement of the coronoid and the proximal ulna. The article describes the radiological findings and outlines the management principles in complex elbow fracture-dislocation injuries.

Dislocations of the elbow - An instructional review

Dislocations of the elbow require recognition of the injury pattern followed by adequate treatment to allow early mobilisation. Not every injury requires surgery but if surgery is undertaken all structures providing stability should be addressed, including fractures, medial and lateral ligament insertion and the radial head. The current concepts of biomechanical modelling are addressed and surgical implications discussed.

Current concepts in elbow fracture dislocation

BACKGROUND

Elbow fracture dislocations are complex injuries that can provide a challenge for experienced surgeons. Current classifications fail to provide a comprehensive system that encompasses all of the elements and patterns seen in elbow fracture dislocations.

METHODS

The commonly used elbow fracture dislocation classifications are reviewed and the three-column concept of elbow fracture dislocation is described. This concept is applied to the currently recognised injury patterns and the literature on management algorithms.

RESULTS

Current elbow fracture dislocation classification systems only describe one element of the injury, or only include one pattern of elbow fracture dislocation. A new comprehensive classification system based on the three-column concept of elbow fracture dislocation is presented with a suggested algorithm for managing each injury pattern.

DISCUSSION

The three-column concept may improve understanding of injury patterns and treatment and leads to a comprehensive classification of elbow fracture dislocations with algorithms to guide treatment.

Management of anteromedial coronoid fractures according to a protocol focused on instability assessment provides good outcomes with infrequent need for coronoid fixation

BACKGROUND

Anteromedial coronoid fractures (AMCFs) are associated with persistent elbow instability and post-traumatic arthritis if managed incorrectly. It is unclear exactly which AMCFs require surgical intervention and how to make this decision. The aims of this study were to report outcomes of AMCFs managed using a protocol based on reproduction of instability using radiographic and clinical testing and to ascertain a threshold size of AMCF associated with instability.

METHODS

Forty-three AMCFs were studied. Thirty-two patients formed the primary study group (group A). All were treated using a protocol in which the decision to perform coronoid fixation was based on the presence of radiographic or clinical evidence of instability. Functional outcomes (Oxford Elbow Score), radiographic outcomes, complications, and reoperations were collected, and a receiver operating characteristic curve analysis was performed to assess the optimal coronoid fracture height to recommend coronoid fixation. The results were compared with a historical group of 11 patients with AMCFs not treated according to the protocol (group B).

RESULTS

Of the patients, 23 had an isolated AMCF and 20 had a concurrent radial head injury. Complete nonoperative treatment of the elbow was performed in 16 patients (37%) (11 of 32 [34%] in group A vs. 5 of 11 [45%] in group B, P = .46). In 10 patients (23%), only repair of the lateral collateral ligament was performed (9 in group A and 1 in group B), whereas 8 patients (19%) underwent repair of the lateral collateral ligament and radial head fixation or replacement (6 in group A and 2 in group B). Acute coronoid fixation was performed in 9 patients (21%) (6 in group A and 3 in group B). At a mean follow-up of 20 months (range, 12-56 months), group A showed a significantly better Oxford Elbow Score (42 vs. 31, P = .02), lower complication rate (3 of 32 [9%] vs. 8 of 11 [72%], P < .001), and lower reoperation rate (1 of 32 [3%] vs. 6 of 11 [54%], P < .001) than group B. Persistent instability was found in 6 patients in group B and none in group A. The receiver operating characteristic curve analysis demonstrated 6.5 mm to be the optimal AMCF size for surgery to prevent persistent instability.

CONCLUSION

Patients treated according to a protocol in which preoperative reproduction of instability determined the degree of surgical intervention had good clinical and radiographic outcomes. Our study demonstrated that AMCFs > 6.5 mm are likely to be more unstable and require intervention. If these principles are followed, a specifically defined subset of AMCFs can be treated nonsurgically without adverse outcomes.

Effect of the medial collateral ligament and the lateral ulnar collateral ligament injury on elbow stability: a finite element analysis

Ligaments are the most important stabilizer of elbow. However, the stress of ligaments is hard to measure because of the complex biomechanical environment in the elbow. Our objective was to develop a human elbow finite element model and to validate it by a comparison with previous experimental data. Then several different ligaments injury conditions and elbow flexion were simulated to analyse the elbow instability and to stress the biomechanical consequences. The computational investigation of different effects of ligament constraints of elbow was studied by means of finite element analysis. The stress of the anterior bundle was almost greater than other ligaments in all conditions, which played the most important role during the elbow flexion. The posterior bundle was the secondary stabilizer during flexion after the anterior bundle. The lateral ulnar collateral ligament (LUCL) injury could result in an increase of the ulnar cartilage stress. The anterior bundle and the LUCL were recommended to be repaired in elbow joint dislocations and fractures. This study could help understand the dynamic effects of ligaments on the joint over the entire extension by investigating the tissue stress.