Addressing the Central Band in Acute and Chronic Essex-Lopresti Injury: A Case Report and Technique Description.

CASE: A 34-year-old man was acutely treated with radial head arthroplasty and central band repair following Essex-Lopresti injury. A 38-year-old man presented with chronic longitudinal instability following failed radial head arthroplasty, which was performed for failed fixation. Treatment with revision radial head arthroplasty and central band reconstruction restored longitudinal stability. CONCLUSION: We have a low threshold to repair the central band in acute Essex-Lopresti injury with sufficient evidence of disruption. Nearly all chronic cases require central band reconstruction to restore longitudinal stability. We do not temporarily pin the DRUJ, and distal ulnar shortening is rarely indicated.

The Contribution of the Distal Oblique Band to Distal Radioulnar Joint Stability.

PURPOSE: The distal radioulnar joint (DRUJ) is supported by an array of dynamic and static stabilizers, of which the triangular fibrocartilage complex (TFCC) is the most important, and the distal interosseous ligament is next in importance. The distal oblique band (DOB) is an identifiable component of the distal interosseous ligament, found in a subset of the population. Our objective was to determine the contribution of the DOB to DRUJ stability in the presence of a disrupted TFCC. METHODS: Twenty-three above-elbow specimens were prepared by removing the TFCC and the DRUJ joint capsule, preserving the distal interosseous ligament and the pronator quadratus. Cadavers were stratified into two groups-those with, and those without a DOB. A bone plate and screws were attached to the ulna; then, a transverse load was applied to failure, creating a diastasis between the radius and ulna. RESULTS: The group with a DOB had a mean load at failure of 160.7 ± 46.5 N. The group without a DOB had a mean load at failure of 148.0 ± 26.3 N. Stiffness prior to failure was 16.9 N/mm in the group with a DOB and 12.4 N/mm in the group without a DOB. CONCLUSIONS: The current results indicate that the DOB may not substantially contribute to DRUJ stability in the presence of a disrupted TFCC. CLINICAL RELEVANCE: Stability of the DRUJ after TFCC injury may not be substantially improved by the presence of a DOB. Thus, the clinical importance of DOB reconstruction remains unclear.

A Medial Approach That Provides Ample Exposure of the Coronoid for Fracture Management.

We describe a medial approach to the coronoid where the flexor-pronator mass is released from its humeral origin by creating a proximally based tendinous flap. This technique facilitates access to the coronoid, preservation of the medial collateral ligament origin, and repair of the flexor-pronator mass. This approach has utility for all coronoid fracture variations but especially the O'Driscoll anteromedial subtype 3, which includes fractures of the sublime tubercle, the anteromedial facet, and the coronoid tip.

Unstable Middle Phalanx Base Fractures Treated With an Internal Joint Stabilizer: Preliminary Results.

BACKGROUND: Unstable fractures of the base of the middle phalanx are notorious for causing chronic loss of proximal interphalangeal (PIP) joint function, and they remain a challenge for the hand surgeon. We report on a temporary intraoperatively constructed internal joint stabilizer for unstable PIP joint injuries. METHODS: Across 2 institutions, a retrospective chart review was performed for cases with acute presentation of pilon fracture or fracture-dislocation of the base of the middle phalanx which were surgically treated with an internal joint stabilizer. Information collected included time from injury to surgical intervention, time from implantation to device removal, complications, and preoperative and postoperative range of motion. RESULTS: Seven patients met the inclusion criteria with a mean age of 51 (range: 24-72) years and a mean follow-up of 29 (range: 11-72) months. After removal of the fixator, the mean arc of PIP joint motion was 8° to 88° (range: 0°-100°). There were no infections, no hardware loosening or failures, and no revision procedures. CONCLUSION: The current findings are comparable to the results for dynamic external fixators. An internal joint stabilizer for unstable injuries to the base of the middle phalanx provides satisfactory functional outcomes, allows early postoperative motion, and mitigates the routine complications which may arise with external fixation.

Flexor Carpi Radialis Tendon Insertion Onto the Trapezial Ridge: An Anatomic Description.

Purpose: The flexor carpi radialis (FCR) tendon is often involved in surgical procedures of the hand and wrist. The FCR tendon may be mobilized from the trapezium during distal radius fracture fixation, for tendon transfer, and during carpometacarpal joint procedures. There is a paucity of literature describing the anatomy of the FCR insertion onto the trapezial ridge. We analyzed the insertional characteristics of the FCR onto the trapezium. Methods: Forty-two fresh-frozen cadaveric wrists were dissected using the extended FCR approach through the FCR tendon sheath. The length of the fibrous portion of the FCR insertion onto the trapezial ridge was measured from proximal to distal using a digital caliper. Results: FCR insertion onto the trapezium was present in all specimens. The mean length of the FCR insertion was 11.8 ± 4.14 mm. The character of the tissue quality varied across specimens. Conclusions: These results demonstrate the commonality of the FCR fibers that insert onto the trapezium. The length and tissue quality of this insertion varied across specimens. Clinical relevance: Understanding the complex anatomy of the hand and wrist facilitates surgical planning and intraoperative techniques. The FCR tendon insertion onto the trapezium is an important component of exposure for the volar approach to the distal radius and surgical management of thumb carpometacarpal joint arthritis.

Acute on Chronic Distal Radius Fracture: A Case Series and Technique Description.

Purpose: Distal radius fractures are the most common fractures in adults. Because of the prevalence of these injuries, patients may present with a repeat distal radius fracture on the same wrist through the site of a malunion. We clinically refer to this as an acute on chronic distal radius fracture. In this setting, the restoration of acceptable alignment can be challenging. There is little guidance in the literature for the management of these fractures. We report our experience with acute on chronic distal radius fractures. The secondary fracture plane was used to correct the prior deformity, and the construct was fixated with a fixed angle volar locking plate. Methods: Records of patients with malunion of the distal radius who experienced an acute fracture of the ipsilateral distal radius were reviewed. Inclusion required treatment with open reduction internal fixation using a distal fragment first technique and a volar locking plate through the extended flexor carpi radialis approach. Clinical outcomes and complications were collected. Results: Across 13 patients, the mean follow-up term was 13 months (range, 6-40 months). Radiographic union was noted in all patients. The mean visual analog scale score for pain was 1.8, and the mean Quick Disabilities of the Arm, Shoulder, and Hand score was 21.9. There were no recorded complications. Conclusion: Our results and described technique provide reproducible guidance for the management of acute on chronic distal radius fractures. These cases can be managed using the secondary fracture plane, a distal fragment first technique, and a volar locking plate to correct the preexisting deformity. Type of study/level of evidence: Therapeutic IV.

Classification and Management of Failed Fixation of the Volar Marginal Fragment in Distal Radius Fractures.

Greater understanding of specific fracture patterns following distal radius fractures has arisen with the advent of volar plating. The volar marginal fragment (VMF) is a small peripheral piece of bone which is critical to carpal stability. Failure to achieve good fixation of the VMF can result in volar subluxation of the carpus and distal radioulnar joint instability. Due to its small, distal nature, this fragment can be easily missed and difficult to fix. Loss of reduction of the VMF following operative fixation presents specific challenges and surgical considerations dictated by patient characteristics and timing. Our goal of this review is to present a classification system for these failed VMFs which can help guide surgical treatment as well as expected outcomes.

Assessment and Management of Acute Volar Rim Fractures.

The volar rim of the distal radius is the only bony restraint to volar carpal subluxation. Higher loads across the volar rim require stable and rigid fixation to maintain reduction and allow healing while rehabilitation begins. Volar marginal fragments are not amenable to buttressing by fixed angle volar locking plates. Appropriate management of volar marginal fragments comprises two steps-recognition of their presence and rigid anatomical repair. The best opportunity for success in the presence of a volar marginal fragment is its adequate initial treatment. The purpose of this review is to reinforce the importance of a complete preoperative and intraoperative evaluation of distal radius fractures. Volar marginal fragments can easily be overlooked even following initial reduction and fixation. Understanding the relevant anatomy and loading parameters can facilitate intraoperative decisions on approach and fixation, which are integral to achieving optimal clinical outcomes.

Surgical Management of Acute on Chronic Distal Radius Fractures: Correcting Malunion Deformities Through the Secondary Fracture Plane.

It is challenging to restore the clinically acceptable alignment of the distal radius after an acute on chronic fracture or after a secondary fracture occurring after malunion of a primary distal radius fracture. In cases of insignificant primary deformity, restoration to the primary deformity may suffice to obtain a successful clinical result. A borderline acceptable primary radial deformity can be unacceptable after the second injury, resulting in functional disability. If surgery is indicated, the surgeon must contend with both primary and secondary deformities to restore proper distal radius anatomy. We present our technique to correct both primary and secondary distal radius deformities through the new or secondary fracture plane.

Tips and Tricks in the Management of Distal Radius Fractures.

Distal radius fractures are common. Volar plating is a valuable approach for many fractures. There are also difficult fractures that require careful attention to the exposure and technique for successful volar plating. Classic approaches, such as external fixation with additional percutaneous reduction and pinning or bone graft and fragment-specific fixation, remain valuable especially when volar plating is not applicable. The main objectives are to review the intricacies of volar plating and the use of external fixation with distal radius fractures. This also includes an understanding of the associated injuries that are present with these fractures and the expected outcome of these injuries relative to the distal radius fracture. First, the challenges with volar locked plating as well as many tips and tricks to help with reduction and stabilization of these fractures are reviewed. Second, the benefits and tips and tricks of external fixation are discussed. Finally, the management of common combined injuries with distal radius fractures is reviewed.

Mitigation of Triceps Avulsion Fracture After Proximal Ulna Plate Fixation.

OBJECTIVES: Triceps avulsion fractures have become an increasingly common postoperative complication of olecranon fracture repair with proximal ulna plate (PUP) fixation. The purpose of this study is to create an efficient, reproducible mechanism to mitigate this issue. METHODS: Ten matched pair cadaveric specimens underwent a complete transverse osteotomy to simulate an olecranon fracture, followed by fracture reduction with a PUP. One arm from each pair underwent an additional augmented suture repair, where the triceps tendon was sutured directly to the plate. A custom jig was used to hold the specimen in position and apply a tensile force on the triceps until mechanical failure. RESULTS: All control specimens (without augmented suture repair) failed through a full-thickness triceps avulsion fracture at an average force of 967.7 N. The augmented suture-repaired specimens failed at an average force of 1204.3 N through partial avulsion fractures, widening of the osteotomy site, and triceps ruptures. CONCLUSIONS: Our study demonstrated that an augmented suture repair of PUP fixation for olecranon fractures is a simple and effective way to significantly increase fixation strength and change the potential failure mechanism.

Flexor Carpi Radialis Brevis Resection for Treatment of a Distal Radius Fracture: A Case Report.

The flexor carpi radialis brevis (FCRB) is an anomalous muscle of the forearm that is only present in 3.5 to 8.6% of the population. In the case of volar plating of distal radius fractures, the FCRB inhibits proper fracture exposure and thus hinders proper reduction. A 78-year-old female presented with right distal radius fracture which necessitated internal fixation. Following mobilization and retraction of the flexor carpi radialis tendon, an anomalous muscle belly was identified as the FCRB. With continued difficulty in exposure and fracture site reduction, resection of the FCRB was performed. The patient was able to return to her activities of daily living without pain and demonstrated no appreciable functional deficit. This case report demonstrates a distal radius fracture where FCRB resection was used, resulting in no detrimental clinical outcomes.

Effect of Ulnar Head Offset on Distal Radioulnar Joint Stability.

PURPOSE: A complete ulnar head replacement may be indicated in cases of distal radial ulnar joint (DRUJ) dysfunction to address bony pathology in lieu of using a constrained total DRUJ prosthesis. Complete ulnar head implants are simple, but they may be unstable if soft tissue tension is not adequately restored. We hypothesized that incorporating an increased offset in the complete ulnar head replacement would lead to increased tension on the distal oblique interosseous ligament, increased contact force at the DRUJ, and improved joint stability. METHODS: Using a specially designed jig, we measured instability by comparing displacement under load (stiffness) of the DRUJ in 10 cadaveric specimens under 4 different conditions: (1) intact, (2) native head after excision of the triangular fibrocartilage complex, (3) replacement of the ulnar head with a standard offset ulnar head, and (4) replacement of the ulnar head with an increased offset ulnar head. No soft tissue repair was done. We measured anteroposterior displacement under load with maximum translation of 10 mm or maximum loads of 50 N. We tested all specimens with the forearm positioned in neutral, supination, and pronation. RESULTS: Excising the triangular fibrocartilage complex decreased the average stiffness of the DRUJ to 46% of the intact state, creating a simulated state of DRUJ instability. Replacing the ulnar head with the standard offset head increased average stiffness to 54% of the intact state. Increasing the ulnar head offset with the simulated total ulnar head replacement increased average stiffness to 77% of the intact state. CONCLUSIONS: An increased offset ulnar head replacement improves DRUJ stability compared with a standard anatomic offset ulnar head replacement. CLINICAL RELEVANCE: Understanding DRUJ morphology and offset is important in the treatment of DRUJ arthritis and instability.

Biomechanical Factors in Stability of the Forearm.

In the forearm, ligaments and joints act in unison to facilitate placement of the hand in 3-dimensional space and transmit loads across the upper extremity. Intricate, effective forearm stabilizers facilitate physiologic motions and restrict abnormal ones. The proximal radioulnar joint, interosseous ligament complex, and distal radioulnar joint work together to ensure the forearm is stable. Each ligament and joint is designed to leverage its biomechanical advantages. Damage destabilizes the synergy of the forearm and results in debilitating injury patterns. Physicians need to understand how all these structures work together to be able to quickly diagnose and treat these forearm injuries.

Intraoperative radiographic method of locating the radial head safe zone: the bicipital tuberosity view.

HYPOTHESIS: The proximal radius is asymmetrical, is mostly articular, and rotates through a large arc of motion. Because of these anatomic factors, there is limited space for hardware. This is magnified in the setting of complex fractures. The portion of the radial head where a radial head plate can be placed without compromising forearm motion has been termed the "safe zone." We hypothesized that the bicipital tuberosity could be used as a reproducible intraoperative fluoroscopic landmark to confirm radial head plate position in the safe zone. METHODS: Seventeen cadaveric radii were evaluated. First, the anatomic safe zone was identified using the method previously described by Caputo et al. A proximal radial plate was then placed in the center of this safe zone. The relationship of the plate to the tuberosity was evaluated, and the angle from the point of the greatest tuberosity profile to the center of the safe zone was measured. RESULTS: The maximum profile of the bicipital tuberosity is 166° ± 10° from the center of the safe zone as described by Caputo et al. By use of radiographic imaging, a radial head plate placed directly opposite the bicipital tuberosity will be within the safe zone. This position can be ascertained fluoroscopically with an anteroposterior view of the proximal forearm, in which the surgeon rotates the forearm into full supination. The plate should be placed opposite the bicipital tuberosity as seen on the greatest profile at maximum supination. With this method, the plate will be consistently placed within the safe zone. CONCLUSION: The bicipital tuberosity can be used as a consistent radiographic anatomic landmark to ensure proximal radial plate placement within the safe zone. If the proximal radial head plate is placed 166° ± 10° opposite the bicipital tuberosity, a landmark easily identified on intraoperative imaging, the implant will be in the safe zone and will not impinge on the ulna in rotation.

The Parallelogram Effect: The Association Between Central Band and Positive Ulnar Variance.

PURPOSE: Ulnar impaction syndrome is a poorly understood degenerative wrist condition characterized by symptoms of pain thought to be caused by increased loads between the ulnar head and the carpals. Radiographic evaluation often reveals an ulnar-positive wrist. We hypothesize that progressive elongation of the central band of the forearm interosseous ligaments changes the longitudinal radial-ulnar relationships, resulting in an ulnar-positive wrist. The objective of the study was to identify a relationship between the loss of integrity of the forearm interosseous ligaments and increased ulnar variance. METHODS: Six cadaveric human forearms were used to measure displacement of the radius relative to the ulna during axial loading of the lunate fossa of the radius. Radial heights were measured in supination and pronation under a 5-lbF (22-N) preload. Gradual axial loads were applied up to 50 lbF (222N); the resultant axial displacement was measured in supination and pronation. All measurements were evaluated with the interosseous ligament intact and repeated with the central band cut. RESULTS: With an applied 5-lbF preload, cutting the central band increased ulnar variance by 3.02 ± 0.80 mm in supination and by 2.15 ± 0.79 mm in pronation. In supination, when the loads were increased from the 5-lbF preload to 50 lbF, the radius displaced 2.1 times further after the central band was cut (3.00 mm) compared with the group with the intact forearm construct (1.41 mm). In pronation, when the loads were increased from the 5-lbF preload to 50 lbF, the radius displaced 1.8 times further when the central band was cut (2.84 mm) than with the intact forearm construct (1.57 mm). CONCLUSIONS: Because of a parallelogram effect, the radius shifted proximally under a 5-lbF preload, creating an ulnar-positive wrist relationship. Dynamic loading of the forearm after ligament excision resulted in significant additional radial displacement relative to the intact forearm. CLINICAL RELEVANCE: Deficiency in the ligamentous restraints of the central band leads to positive ulnar variance, which could be a factor (among others) that contributes to idiopathic ulnar impaction syndrome.