Ulnar styloid fracture with distal radius fracture

Management of Ulnar Styloid Nonunions

Ulnar styloid fractures commonly occur in the setting of distal radius fractures and often progress to asymptomatic nonunion. Displaced basilar ulnar styloid fractures involving the deep radioulnar ligament attachments may cause distal radioulnar joint (DRUJ) instability. A careful clinical history, physical examination, review of imaging studies, and selected diagnostic interventions are important for confirming the relationship of the ulnar styloid nonunion with ulnar-sided wrist symptoms and/or DRUJ instability. Improved functional and symptomatic outcomes can be achieved with nonunion repair or fragment excision with or without triangular fibrocartilage complex repair, depending on the location and size of the ulnar styloid fracture.

Is it necessary to fix basal fractures of the ulnar styloid after anterior plate fixation of distal radius fractures? A randomized controlled trial

The purpose of this study was to investigate the necessity for surgical fixation of basal fractures of the ulnar styloid without distal radioulnar joint (DRUJ) instability, after stabilization of associated distal radial fractures using an anterior plate. This single-centre, prospective, randomized controlled trial, conducted between 2015 to 2021, included 43 patients in each study arm who were randomized to either fixation (Group A) or non-operative treatment (Group B) of the ulnar styloid. The mean follow-up period was 24 months (SD 5.2) in Group A and 23.9 months (SD 5.5) in Group B. At the final follow-up, patients were evaluated by the Disabilities of the Shoulder, Arm, and Hand (DASH) score, the Modified Mayo Wrist Score (MMWS), the visual analogue scale (VAS) for pain, the grip strength, wrist range of motion. The DASH score was 6 (SD 2.6) in Group A and 6 (SD 2.4) in Group B; the MMWS was 87 (SD 5.6) in Group A and 87 (SD 5.6) in Group B; and the grip strength was 88% (SD 9.4) in Group A and 87% (SD 7.7) in Group B. In conclusion, fixation of basal ulnar styloid fractures is not mandatory if the DRUJ is stable after rigid fixation of the associated fracture of the distal radius.Level of evidence: II.

Residual stability of the distal radioulnar joint following ulnar styloid fracture: influence of the remnant distal radioulnar ligaments

Clinical studies suggest that even untreated basal ulnar styloid fractures may not affect patient outcomes. This may be due to the remaining parts of the distal radioulnar ligament still attached providing sufficient residual stability of the distal radioulnar joint. We tested this hypothesis in a biomechanical cadaveric model. Dorsopalmar translation of the distal radioulnar joint and forearm rotation were measured. Seventeen specimens were tested after a simulated ulnar styloid fracture including the fovea, followed by transection of the remaining palmar (n = 9) or dorsal (n = 8) portions of the distal radioulnar ligament and finally with all remnants transected. Rotation and translation both increased significantly after the final transection compared with the foveal fracture. The increase in translation was larger after transection of the dorsal remnants. We conclude that in an ulnar styloid fracture including the fovea, some ligament components are still attached to the ulnar head, giving residual stability to the distal radioulnar joint.

The Critical Size of Ulnar Styloid Fragment for the DRUJ Stability

Background  Ulnar styloid fractures can be associated with clinically significant instability of the distal radioulnar joint (DRUJ). However, the exact fragment size that results in DRUJ instability is unknown. Purpose  The objective of this study was to determine the critical size of an ulnar styloid fracture that would result in a significant increase in DRUJ translation and forearm rotation. Methods  Eight cadaveric specimens were used to investigate the effects of three different ulnar styloid fracture sizes on DRUJ instability: tip fracture, base fracture, and a fracture including the fovea. Forearm rotation and dorsopalmar DRUJ translation were measured after each sequential increase in fracture size. Results  Relative to the uninjured state, a significant increase in forearm rotation and dorsopalmar translation was found for all three fractures. However, the fovea fracture showed a statistically significant increase in forearm rotation compared with all other fracture types and a statistically significant increase in total dorsopalmar translation compared with the tip fracture. Conclusion  In this study, ulnar styloid fractures involving the fovea resulted in significantly greater DRUJ instability comparted to tip and base fractures alone. This study provides important biomechanical data regarding the critical size of ulnar styloid fractures that result in DRUJ instability and may aid in the surgical decision-making algorithm in these patients.

Should We Repair the Pronator Quadratus in a Distal Radius Fracture with an Ulnar Styloid Base Fracture? A Biomechanical Study

Background  Merits of repairing the pronator quadratus (PQ) to restore distal radioulnar joint (DRUJ) stability after a volar approach remain controversial. Distal radius fractures are often associated with ulnar styloid fractures (USF). When involving the fovea, this USF can lead to a DRUJ instability. The PQ repair may be key in reducing this DRUJ instability. Methods  This study aims to assess the biomechanical role of PQ repair in a cadaveric model of USF. In 17 forearm specimens, a USF including the fovea was executed. Positional changes of the DRUJ in forearm rotation and dorso-palmar (DP) translation were measured with variable loads (0, 2.5, and 5N) applied to the PQ origin. Results  Forearm rotation and DP-translation decreased significantly with PQ loading of 5N, changing on average by 5 degrees and 0.6 mm, respectively. Conclusion  We found a significant decrease in forearm rotation and DP-translation comparing a fully loaded PQ to an unloaded PQ in our cadaveric model.

What's the best surgical repair technique of an ulnar styloid fracture? A biomechanical comparison of different techniques

INTRODUCTION

8-10% of all Ulnar styloid fractures (USF) accompanying distal radius fractures are addressed surgically. The surgical fixation has to counteract forces of translation and rotation acting on the distal radioulnar joint (DRUJ). The different technics used were never compared biomechanically. Our study aims to compare the effects of different techniques of USF fixation on the forearm rotation and the dorsal-palmar (DP)-translation of the DRUJ.

MATERIAL AND METHODS

9 forearm specimens were mounted on a custom testing system. Load was applied for Pronosupination and DP-translation with the forearm placed in neutral position, pronation and supination. The positional change of the DRUJ was measured using a MicroScribe. Six different, sequential conditions were tested in the same specimen: intact, USF and 4 repair techniques (2 K-wire, tension band wiring (TBW), headless compression screw, suture anchor).

RESULTS

The USF significantly increased DP-translation and pronosupination compared to the intact condition. The DP-translation in neutral was reduced significantly with all four techniques compared to the USF condition. TBW and suture anchor also showed a significant difference to the K-wire fixation. In supination only the TBW and suture anchor significantly decreased DP-Translation. The rotational stability of the DRUJ was only restored by the K-wire fixation and the TBW.

CONCLUSIONS

All four USF repair techniques partially restored translational stability; however, only K-wire fixation and TBW techniques restored rotational stability. TBW was biomechanically superior to the other techniques as it restored translational stability and rotational stability.

Distal Radius Fracture and the Distal Radioulnar Joint

In this article, we discuss the incidence and types of injuries to the distal radioulnar joint (DRUJ) that occur in the setting of a distal radius fracture. We review the anatomy of the distal radioulnar joint, which is critical to understanding its biomechanics, and how injury could cause symptomatic incongruency and instability. We highlight how patients with an injury to the distal radioulnar joint might present both at the time of injury and after treatment of a distal radius fracture, the appropriate workup, the available treatment options, and the evidence-based literature.

The Presence and the Location of an Ulnar Styloid Fracture Associated With Distal Radius Fracture Predict the Presence of Triangular Fibrocartilage Complex 1B Injury

PURPOSE

To investigate the correlation between ulnar styloid fracture (USF) associated with distal radius fracture (DRF) and triangular fibrocartilage complex (TFCC) injuries and to elucidate whether the presence or location of an USF in a patient with DRF predicts the presence of traumatic TFCC injuries.

METHODS

From 2005 to 2018, an arthroscopic evaluation was performed to detect TFCC injuries associated with DRF. The presence and location of USFs were evaluated using computed tomography. TFCC injuries were classified in accordance with Palmer's classification. All wrists were divided into group A (DRF without USF) and group B (DRF with USF). The incidence of TFCC injuries in the 2 groups was compared. group B was then divided into 2 subgroups in accordance with the USF location: the tip or middle fracture subgroup and the base fracture subgroup. Data were analyzed with significance set at P < .05.

RESULTS

One hundred thirty-eight patients were enrolled in this study. Group A included 42 wrists in 42 patients, whereas group B included 96 wrists in 96 patients. There were significant differences between the 2 groups regarding the incidence of traumatic TFCC injuries (P = .036) and TFCC 1B injury (P = .002), although there were no differences between the 2 groups regarding age, sex, injured side, direction of displacement, and type of DRF. Within group B, the tip and middle fracture subgroup included 37 wrists in 37 patients, whereas the base fracture group included 59 wrists in 59 patients; a significant difference was observed between the two subgroups regarding the incidences of TFCC 1B injuries (P = .044).

CONCLUSIONS

The presence of USF associated with DRF predicted the presence of frequently occurring traumatic TFCC injury and TFCC 1B injury. Moreover, the location of USFs was a predictive factor for TFCC 1B injury in adults with DRF. On the other hand, traumatic TFCC injury had occurred in adults with DRF, regardless of the presence of USF.

LEVEL OF EVIDENCE

Level IV, Case series.

Effects of Ulnar Styloid Fractures on Unstable Distal Radius Fracture Outcomes: A Systematic Review of Comparative Studies

Purpose  In this literature review, functional outcomes such as Disability of Arm, Shoulder and Hand (DASH) score and the visual analog scale (VAS) of pain along with clinical outcomes such as range of movement and grip strength of treated distal radius fractures (DRF) accompanied with ulnar styloid fractures (USF) will be compared with those with isolated DRF. Materials and Methods  We analyzed articles from MEDLINE, Embase, and CINAHL that met our predetermined inclusion and exclusion criteria as per the Preferred Reporting Items for Systematic Reviews and Meta-analysis statements. This resulted in the identification of 464 articles with 18 potentially eligible studies of which 6 were included at the full-text screening stage. The primary outcomes were wrist pain, range of motion, functional outcome and satisfaction, such as VAS, and the DASH questionnaire along with radiological assessment and incidence of complications. Results  These studies involved 796 participants with DRF and 806 wrists with DRF; 444 (55%) of DRF had an associated USF. Three studies did not report any statistically significant difference in DASH scores between the DRF patients with or without USF. Two studies reported worse DASH scores in the group with associated USF. Wrist pain was reported to be statistically significantly worse in patients with associated USF in two studies. Grip strength did not exhibit a statistically significant difference in any groups in four studies. On assessing the range of motion of the wrist and forearm, only one study reported a statistically significant difference in flexion at 2 years follow-up, with less flexion in patients with USF. Conclusion  This review suggests that there is no significant correlation between a USF and the functional and clinical outcomes of DRF treatment, albeit wrist pain and less flexion were reported in some studies to be associated with USF. There is a need for more robust evidence from large randomized controlled trials to specifically look at the effects of fixation versus nonfixation of USF on DRF, or large prospective cohort studies assessing DRF with and without USF, with a minimum of 12 months follow-up. Level of Evidence  Level II-therapeutic.

Ulnar Styloid Base Fractures Cause Distal Radioulnar Joint Instability in a Cadaveric Model

BACKGROUND

The deep portion of the distal radioulnar ligaments (DRUL) inserts on the ulnar fovea and is the most important stabilizer of the distal radioulnar joint (DRUJ). Ulnar styloid base fractures that include the ulnar fovea may cause DRUJ instability.

METHODS

DRUJ stability in pronosupination was evaluated in 12 fresh-frozen upper extremities (4 female) aged 52 to 68 years (mean: 58.8 years) using a custom fixture, which allowed free rotation of the radius around the fixed ulna. Optical motion capture was used to record rotation of the radius with respect to the ulna. Each specimen was subjected to 3 N m of torque in both supination and pronation under 4 conditions: intact, ulnar styloid osteotomy with disruption of the foveal insertion of the DRUL, ulnar styloid fixation, and DRUL transection. Group differences were compared using a 1-way repeated-measures analysis of variance and Tukey multiple comparison post hoc tests.

RESULTS

When compared with the intact condition, both ulnar styloid osteotomy and DRUL transection significantly increased mean pronation (by 9.40° and 15.21°, respectively) and supination (by 9.05° and 17.42°, respectively) of the forearm. Screw fixation only significantly reduced pronation compared with osteotomy (by 2.62°). Screw fixation did not significantly affect supination.

CONCLUSIONS

Ulnar styloid fractures that disrupt the fovea cause instability of the DRUJ in pronation and supination under 3 N m of torque in a cadaveric model. Screw fixation of ulnar styloid base fractures achieves anatomic reduction; however, it only partially returns rotational stability acutely to the DRUJ and only during pronation.

Supination and Pronation Strength Deficits Persist at 2-4 Years after Treatment of Distal Radius Fractures

Forearm rotation is a key function in the upper extremity. Following distal radius fracture, residual disability may occur in tasks requiring forearm rotation. The objectives of this study are to define pronation and supination strength profiles tested through the range of forearm rotation in normal individuals, and to evaluate the rotational strength profiles and rotational strength deficits across the testing range in a cohort of patients treated for distal radius fracture associated with an ulnar styloid base fracture. In a normative cohort of 29 subjects the supination strength profile showed an increasing linear relationship from supination to pronation. Twelve subjects were evaluated 2-4 years after anatomical open reduction and volar plate fixation of a distal radius fracture. The injured wrist was consistently weaker (corrected for hand dominance) in both supination and pronation strength in all testing positions, with the greatest loss in 60 degrees supination. Mean supination strength loss across all testing positions was significantly correlated with worse PRWE scores, highlighting the importance of supination in wrist function.

Distal ulna fractures

In isolation, distal ulna fractures are rare. They are often found in conjunction with distal radius fractures, and the complexity of the interaction of the distal ulna with the radioulnar joint and triangular fibrocartilage complex makes understanding and treatment of distal ulna fractures challenging. Fixation of distal ulna fractures can be problematic owing to comminution making reduction challenging. A thin soft tissue can lead to hardware prominence and necessitate implant removal. In this Current Concepts article, we review the anatomy, pathology, and treatment of distal ulna fractures as well as potential complications and salvage procedures.

Distal radius fractures: current concepts

Despite the frequency of distal radius fractures, the optimal treatment remains without consensus opinion. A trend toward increased distal radius fracture open reduction and internal fixation has been identified, with biomechanical and clinical studies suggesting treatment advantages of certain fixation methods over others. Well-controlled patient trials are still missing to lend objective findings to management algorithms. This article reviews the literature over the past 5 years to guide our management regarding this common upper-extremity injury.