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.

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.

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.

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.

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.

Multicenter trial of an internal joint stabilizer for the elbow.

BACKGROUND: Our primary efficacy objective was to evaluate the effectiveness of the internal joint stabilizer of the elbow (IJS-E) in maintaining concentric location of the elbow during and after removal of the device in the treatment of persistent or recurrent instability after elbow fracture or dislocations, or both. The secondary study objectives were to assess range of motion, Broberg-Morrey functional score, Broberg-Morrey categorical rating, the Disabilities of the Arm, Shoulder and Hand score, and the rate of complications and adverse events after the use of IJS-E. METHODS: Twenty-four patients were studied in a multicenter, nonrandomized, prospective, single-arm study. The IJS-E was used to provide temporary stabilization of the elbow joint and allow a functional range of motion while ligaments and fractures healed. RESULTS: The elbow remained concentrically aligned in 23 of 24 patients. One coronoid-deficient elbow did not maintain concentric reduction. At the last evaluation a minimum of 6 months after device removal, the mean arc of elbow flexion was 119° (range, 80°-150°; standard deviation [SD], 18°), and the mean arc of forearm rotation was 151° (range, 90°-190°; SD, 24°). The mean and median Broberg-Morrey scores were 93 and 97, respectively. Categorically the results were excellent in 14, good in 8, fair in 1, and poor in 1. The mean Disabilities of the Arm, Shoulder and Hand score was 16 (range, 0-68; SD, 18). CONCLUSION: The IJS-E maintains concentric reduction, allows elbow motion, and avoids the inconveniences and pin problems of percutaneous fixation.

The EFCR Approach and the Radial Septum-Understanding the Anatomy and Improving Volar Exposure for Distal Radius Fractures: Imagine What You Could Do With an Extra Inch.

Locked volar plating is the most common surgical procedure to address distal radius fractures. The extended flexor carpi radialis approach continues to be an excellent method for visualizing distal radius fractures and applying a volar plate. A new understanding of the anatomy allows for better visualization and reduction of the many different distal radius fracture patterns surgeons commonly see. Within the extended flexor carpi radialis approach, we describe the radial septum in further detail including the anatomy which comprises the radial septum triangle. Knowledge of this area allows for better visualization, more anatomic reductions, and fewer complications.

Prevent Collapse and Salvage Failures of the Volar Rim of the Distal Radius.

Background Articular fractures of the distal radius may include a small fragment from the volar margin of the lunate fossa: volar marginal fragments (VMFs); these fragments are prone to loss of fixation and avascular necrosis, and often result in wrist subluxation. We present our experience managing acute and delayed VMFs. The first is treated using a hook plate extension to a volar locking plate and the latter using a volar opening wedge osteotomy to redistribute loads on the remaining articular surface. Materials and Methods We retrospectively reviewed the records of all patients treated at our facility with a hook plate extension for a VMF and for patients treated with a volar opening wedge osteotomy. Medical charts were examined for complications and functional results. Technique A hook plate extension was used to fix the VMF when plate buttressing was insufficient. For patients who presented a collapsed and reabsorbed VMF, a volar opening wedge osteotomy was used to reorient the articular surface, restoring joint stability. Results The hook plate extension was successful in managing 19 of the 21 acute VMFs. The volar opening wedge osteotomy provided concentric reduction and improved pain and motion in all treated patients. Conclusion We demonstrated that hook plate fixation of the VMF is an effective means of fixing the acute VMF and that a volar opening wedge osteotomy can be used to salvage a distal radius fracture with a collapsed VMF.

The transverse force experienced by the radial head during axial loading of the forearm: A cadaveric study.

BACKGROUND: When designing a radial head replacement, the magnitude and direction of forces applied across the proximal radio-ulnar joint (PRUJ) and the radiocapitellar joint must be included. These designs often focus on axial loads transmitted to the radial head by the capitellum; however, the radial head also bears a significant transverse force at the PRUJ. Load transmission by the central band of the interosseous ligament induces a force component in a lateral direction perpendicular to the axis of the limb, which is borne by the articular surfaces of the proximal and distal radio-ulnar joints. The objective of this study is to establish the relationship between distally applied axial forces and proximal transverse reaction forces. METHODS: Five cadaveric, human forearms with intact interosseous membranes were used to measure the magnitude of transversely-directed forces experienced by the radial head during axial loading of the forearm at the lunate fossa. A Mark-10 test stand applied a gradual and continuous axial load on the articular surface of the distal radius. A Mark-10 force gauge measured the resultant transverse force experienced by the radial head in the proximal radioulnar joint. Classical mechanics and static force analysis were applied in order to predict lateral force values that would occur when the interosseous ligament is treated as the major load transmitter between the radius and ulna. FINDINGS: Acquired data show that the radial head bears a force in the transverse direction that averages 18% (SD 3.89%) in magnitude of the axial force applied at the wrist. This figure is in close accordance with the predicted value of 22% that was calculated by way of free-body plotting. INTERPRETATION: Physiologic forearm loading results in a clinically significant transverse force component transmitted through the interosseous ligament complex. The existence of transverse forces in the human forearm may explain clinical problems seen after radial head resection and suggest that radial head implants be designed to sustain substantial transverse forces. LEVEL OF EVIDENCE: Basic science study, anatomical.

The management of elbow instability using an internal joint stabilizer: preliminary results.

BACKGROUND: Nonsurgical and surgical treatments such as immobilization, transarticular pinning, and hinged or nonhinged external fixation have been used to treat unstable elbows. These methods all have drawbacks. We thought that a bent Steinmann pin introduced through the axis of ulnohumeral rotation and attached to the ulna could provide an improved method of treatment and that this could result in the development of a proper internal joint fixator that may have widespread application. QUESTIONS/PURPOSES: Does a fully internal hinged fixator crafted intraoperatively by the surgeon from a Steinmann pin for patients undergoing surgery for severe elbow instability result in restoration of range of motion and elbow stability? Does it result in new complications? METHODS: We reviewed the first 10 patients treated with the method for elbow instability. Diagnoses included fracture-dislocations of the elbow that remain unstable after fracture repair and unstable elbows that result from release of contracture or ulnohumeral synostosis. During that time, all patients meeting these criteria who underwent surgery by this surgeon (JLO) were treated with this approach. Charts, radiographs, and therapy notes were assessed at a minimum of 14 months (mean, 32 months; range, 14-59 months); no patients were lost to followup. Data recorded included age, sex, and elbow and forearm range of motion as well as any complications and reoperations that occurred. The absence of elbow instability was determined initially by radiographically observing concentric reduction of the ulnohumeral and radiocapitellar joints and later by radiography plus the absence of clinical signs and symptoms of elbow instability. RESULTS: Mean range of motion at latest followup was flexion 134°, extension -19°, pronation 75°, and supination 64°. All elbows were clinically and radiographically stable. Complications resulting in additional procedures occurred in four patients, including one recurrent deep infection in a patient with a remote history of sepsis, one wound hematoma that resolved after a drainage procedure performed in the office, one prominent implant treated by partial removal, and one patient with heterotopic ossification treated with excision of the heterotopic bone. CONCLUSIONS: This technique restores elbow stability and permits motion without the use of transcutaneous pins. It seems promising for the treatment of patients with severe elbow instability but requires a second procedure for removal. Further investigation is needed to understand its place in the surgeon's toolbox and what drawbacks it may have. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Volar plate fixation of intra-articular distal radius fractures: a retrospective study.

Background Intra-articular fractures of the distal radius represent a therapeutic challenge as compared with the unstable extra-articular fractures. With the recent development of specifically designed internal fixation materials for the distal radius, treatment of these fractures by fragment-specific implants using two or more incisions has been advocated. Purpose The purpose of this study was to investigate the efficacy of a fixed-angle locking plate applied through a single volar approach in maintaining the radiographic alignment of unstable intra-articular fractures as well as to report the clinical outcomes. We only excluded those with massive comminution, as is discussed in greater detail in the text. Patients and Methods This is a multicentered, retrospective study involving three hospitals situated in Spain, Switzerland, and the United States. In the period between January 2000 and March 2006, 97 patients with 101 intra-articular distal radius fractures, including 13 volarly displaced and 88 dorsally angulated fractures were analyzed. Over 80% were C2/C3 fractures, based on the AO classification. 16 open fractures were noted. Results With an average follow-up of 28 months (range 24-70 months), the range of movement of the wrist was very satisfactory, and the mean grip strength was 81% of the opposite wrist. The Disabilities of the Arm, Shoulder, and Hand (DASH) score was 8. The complications rate was < 5%, including loss of reduction in two patients. All fractures healed by 3 months postinjury. Conclusions Irrespective of the direction and amount of initial displacement, a great majority of intra-articular fractures of the distal radius can be managed with a fixed-angle volar plate through a single volar approach. Level IV retrospective case series.