Anatomic relations of the median nerve to the ulnar insertion of the brachialis muscle: safety issues and implications for medial approaches to the elbow joint

[Augmented primary sutures "internal bracing" following ligamentous elbow dislocation]

OBJECTIVE

Aim of surgical treatment is the primary stabilization of the unstable elbow following a ligamentous elbow dislocation.

INDICATIONS

Ligamentous elbow dislocations are typically accompanied by injuries to the surrounding musculature and collateral ligaments of the elbow joint. Surgical treatment is indicated in case of failure of nonoperative therapy, i.e., when a dislocation can only be prevented in immobilization > 90° and pronation of the elbow or an active muscular centering of the elbow fails after 5-7 days.

CONTRAINDICATIONS

Contraindications for a solely "internal bracing" augmented primary suture are generally in the case of accompanying bony injuries in elbow dislocations, extensive soft-tissue injuries, and septic arthritis of the elbow.

SURGICAL TECHNIQUE

The augmented primary suture of the elbow is performed using both a lateral (Kocher or Kaplan) and medial (FCU split) approach to the elbow. After reduction of the elbow, the collateral ligaments are first augmented with high-strength polyethylene suture and fixed in the distal humerus together with another high-strength polyethylene augmentation suture. The extensors and flexors are then fixed to the medial and lateral epicondyle, respectively, using suture anchors.

POSTOPERATIVE MANAGEMENT

The aim of the postoperative management is early functional exercise of the elbow. The elbow is placed in an elbow brace to avoid varus and valgus load.

RESULTS

Between August 2018 and January 2020, a total of 12 patients were treated with an augmented primary suture following unstable ligamentous elbow dislocation. After a mean follow-up of 14 ± 12.7 months, the mean Mayo Elbow Performance Score was 98.5 points with a mean functional arc of 115°. None of the patients reported a recurrent dislocation or persistent instability of the elbow.

Novel Radiographic Indexes for Elbow Stability Assessment: Part A-Cadaveric Validation

INTRODUCTION

Elbow bony stability relies primarily on the high anatomic congruency between the humeral trochlea and the ulnar greater sigmoid notch. No practical tools are available to distinguish different morphotypes of the proximal ulna and herewith predict elbow stability. The aim of this study was to assess inter-observer reproducibility, evaluate diagnostic performance and determine responsiveness to change after simulated coronoid process fracture for three novel elbow radiographic indexes.

METHODS

Ten fresh-frozen cadaver specimens of upper limbs from human donors were available for this study. Three primary indexes were defined, as well as two derived angles: Trochlear Depth Index (TDI); Posterior Coverage Index (PCI); Anterior Coverage Index (ACI); radiographic coverage angle (RCA); olecranon-diaphisary angle (ODA). Each index was first measured on standardized lateral radiographs and subsequently by direct measurement after open dissection. Finally, a type II coronoid fracture (Regan and Morrey classification) was created on each specimen and both radiographic and open measurements were repeated. All measurements were conducted by two orthopaedic surgeons and two dedicated musculoskeletal radiologists.

RESULTS

All three indexes showed good or moderate inter-observer reliability and moderate accuracy and precision when compared to the gold standard (open measurement). A significant change between the radiographic TDI and ACI before and after simulated coronoid fracture was observed [TDI: decrease from 0.45 ± 0.03 to 0.39 ± 0.08 (p = 0.035); ACI: decrease from 1.90 ± 0.17 to 1.58 ± 0.21 (p = 0.001)]. As expected, no significant changes were documented for the PCI. Based on these data, a predictive model was generated, able to identify coronoid fractures with a sensitivity of 80% and a specificity of 100%.

CONCLUSION

New, simple and easily reproducible radiological indexes to describe the congruency of the greater sigmoid notch have been proposed. TDI and ACI change significantly after a simulated coronoid fracture, indicating a good responsiveness of these parameters to a pathological condition. Furthermore, combining TDI and ACI in a regression model equation allowed to identify simulated fractures with high sensitivity and specificity. The newly proposed indexes are, therefore, promising tools to improve diagnostic accuracy of coronoid fractures and show potential to enhance perioperative diagnostic also in cases of elbow instability and stiffness.

LEVEL OF EVIDENCE

Basic science study.

CLINICAL RELEVANCE

The newly proposed indexes are promising tools to improve diagnostic accuracy of coronoid fractures as well as to enhance perioperative diagnostic for elbow instability and stiffness.

Novel Radiographic Indexes for Elbow Stability Assessment: Part B-Preliminary Clinical Study

INTRODUCTION

The coronoid process plays a key-role in preserving elbow stability. Currently, there are no radiographic indexes conceived to assess the intrinsic elbow stability and the joint congruency. The aim of this study is to present new radiological parameters, which will help assess the intrinsic stability of the ulnohumeral joint and to define normal values of these indexes in a normal, healthy population.

METHODS

Four independent observers (two orthopaedic surgeons and two radiologists) selected lateral view X-rays of subjects with no history of upper limb disease or surgery. The following radiographic indexes were defined: trochlear depth index (TDI); anterior coverage index (ACI); posterior coverage index (PCI); olecranon-coronoid angle (OCA); radiographic coverage angle (RCA). Inter-observer and intra-observer reproducibility were assessed for each index.

RESULTS

126 subjects were included. Standardized lateral elbow radiographs (62 left and 64 right elbows) were obtained and analysed. The mean TDI was 0.46 ± 0.06 (0.3-1.6), the mean ACI was 2.0 ± 0.2 (1.6-3.1) and the mean PCI was 1.3 ± 0.1 (1.0-1.9). The mean RCA was 179.6 ± 8.3° (normalized RCA: 49.9 ± 2.3%) and the mean OCA was 24.6 ± 3.7°. The indexes had a high-grade of inter-observer and intra-observer reliability for each of the four observers. Significantly higher values were found for males for TDI, ACI, PCI and RCA.

CONCLUSION

The novel radiological parameters described are simple, reliable and easily reproducible. These features make them a promising tool for radiographic evaluation both for orthopaedic surgeons and for radiologists in the emergency department setting or during outpatient services.

LEVEL OF EVIDENCE

Basic Science Study (Case Series).

CLINICAL RELEVANCE

The novel radiological parameters described are reliable, easily reproducible and become handy for orthopaedic surgeons as well as radiologists in daily clinical practice.