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

Incidence and predictors of dorsal comminution in older adults with low-energy distal radius fracture

PURPOSE

To identify the incidence of dorsal comminution using computed tomography (CT) images and identify predictors of this phenomenon in older adults with low-energy distal radius fractures (DRFs).

METHODS

A total of 150 patients aged > 50 years with fall-induced dorsally angulated DRFs were enrolled in this study. Patients were divided into two groups based on the presence of dorsal comminution, defined as a metaphyseal void of greater than one-third of the maximum posterior to anterior depth of the bone on at least three cuts in the sagittal plane on post-reduction CT images. Data on participants' basic demographics, including age, sex, body mass index (BMI), and AO classification of DRFs, were collected. Bone mineral density (BMD) was assessed using T-scores of the femoral neck, and cortical thickness of the distal radius was determined from plain post-reduction radiographs. Radiological parameters and combined ulnar fractures were measured on plain pre-reduction radiographs.

RESULTS

Among study participants, 91 (61%) had dorsal comminution, whereas 59 (39%) had no dorsal comminution on CT images. Both patient groups were compared based on presence of dorsal comminution, and showed no significant differences in age, sex, BMI, BMD, or cortical thickness on radiographs. However, all radiological parameters were better in the no dorsal comminution group than in the dorsal comminution group, and the proportion of patients with combined ulnar fractures was higher in the dorsal comminution group. In the multivariate analysis, the presence of combined ulnar fractures was the only significant predictor of dorsal comminution (p = 0.029, odds ratio = 2.267, 95% confidence interval: 1.085-4.736).

CONCLUSION

The incidence of dorsal comminution is relatively high in patients with low-energy DRFs aged > 50 years. In particular, the presence of combined ulnar fractures is closely associated with dorsal comminution of DRFs. Thus, surgeons should exercise caution when evaluating this phenomenon.

Distinct patterns of fracture propagation in distal radial fractures and the relationship to the ulnar head

BACKGROUND

The aim was to assess the direction of distal radius fractures and their relationship to the ulnar head.

METHODS

We reviewed the 160 wrist radiographs. The fracture line was measured on the postero-anterior and lateral radiographs relative to the long axis of the forearm and the relationship to the ulnar head.

FINDINGS

PA radiographs: the fracture line ran distal ulnar to proximal radial (ulnar to radial) in 11%, transverse in 74% and distal radial to proximal ulnar (radial to ulnar) in 16%. Lateral radiographs: the fracture line ran distal volar to proximal dorsal in 88%, transverse in two 1% and dorsal to volar in 11%. Radial shift (7.5%) only occurred with ulnar to radial or transverse fractures. The ulnar to radial fracture line started at the proximal end of the ulnar head/distal radio-ulnar joint in 88%. The radial to ulnar fracture line started ended a mean of 2.5 mm proximal to the distal radio-ulnar joint (p < 0.01). The transverse fracture line started at the base of the distal radio-ulnar joint in 53% and proximally in 47%.

INTERPRETATION

There are two distinct coronal patterns: radial to ulnar ending c. 2 mm proximal to the distal radio-ulnar joint; ulnar to radial starting at the proximal distal radio-ulnar joint. There may be third pattern - transverse fractures; these may be variants of the above. Sagittally the main direction is volar to dorsal but 11% are obverse. This is the first description of distinct fracture patterns in extra-articular distal radius fractures. In addition the fracture patterns appear to correlate with different directions of force transmission which fit with our understanding of falling and the relatively uncontrolled impact of the wrist/hand with the ground. These patterns of fracture propagation help understand how the biomechanics of wrist fractures and may enable prediction of collapse.

Should ulnar styloid be fixed following fixation of a distal radius fracture?. Injury 2023;54:110768. [PMID: 37210301 DOI: 10.1016/j.injury.2023.04.055]

INTRODUCTION

Fracture of the base of the ulnar styloid has shown to have higher incidence of TFCC tears and DRUJ instability leading to nonunion and impaired function. Poorer functional outcomes of the distal radius fracture have been attributed to the untreated associated ulnar styloid fractures while some studies have shown no difference. Thus, the treatment remains controversial. However, it has been shown that fractures at the base of the ulnar styloid have a higher incidence of tears in the triangular fibrocartilage complex (TFCC) and instability in the distal radioulnar joint (DRUJ), which can lead to nonunion and impaired function. Despite this, there are currently no studies comparing the outcomes of surgically and conservatively treated patients.

METHODS

A retrospective study was conducted to analyze the outcomes of intra-articular distal radius fractures associated with base of ulnar fracture treated with distal radius LCP fixation. The study included 14 patients who were treated surgically and 49 patients who were treated conservatively, with a minimum follow-up of 2 years. Radiological parameters such as union and amount of displacement, VAS score for ulnar-sided wrist pain, functional assessment using the modified Mayo score and the quick DASH questionnaire and complications were analyzed.

RESULTS

At the final follow-up, the mean scores for pain (VAS), functional outcomes (modified Mayo score), disability (QuickDASH score), range of motion, and non-union rate were found to be statistically insignificant (p > 0.05) between the surgically treated and conservatively treated groups. However, patients with non-union had statistically significant higher scores for pain (VAS), greater post-operative displacement of the styloid, poorer functional outcomes, and higher disability (p < 0.05).

CONCLUSION

While there was no significant difference in ulnar-sided wrist pain and functional outcomes between the surgically treated and conservatively treated groups, the conservatively treated cases had a higher risk of non-union, which can negatively impact functional outcomes. The amount of pre-operative displacement was found to be a key factor in predicting non-union and can be used as a guide for determining the management of this type of fracture.

The distal radioulnar joint after distal radial fractures: when and how do we need to treat pain, stiffness or instability?

The importance of distal radioulnar joint problems associated with distal radial fractures is recognized increasingly. But there remains considerable disagreement about how to treat these problems both acutely and chronically. This review outlines the knowledge about the natural history of ulnar-sided wrist problems with distal radials fractures. In particular, the recent increased understanding of the almost inevitable joint instability associated with distal radial fractures is highlighted, including the unreliability of clinical assessment and hence why there has been so much misunderstanding. Provided there is reasonable bony alignment, most ulnar-sided wrist problems can be treated non-operatively initially (typically for over a year) in anticipation of substantial improvement with time. The exception is early marked subluxation of the distal radioulnar joint (DRUJ) blocking forearm rotation, which needs urgent (typically closed) reduction.

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.

Ulnar Styloid Fracture Accompanying Distal Radius Fracture Does Not Affect Hand Function, but What About Hand Dexterity?

Introduction  Hand dexterity is not addressed in patients with distal radius fracture (DRF) accompanied with ulnar styloid fracture (USF) in literature. This study aimed to determine whether an associated USF following a DRF has any effect on hand dexterity. Materials and Methods  Patients diagnosed with DRF were included in the study and were divided into two groups according to the USF presence (USF group and non-USF group). Pain, range of motion, Quick-DASH (Quick-Disabilities of the Arm, Shoulder, and Hand), handgrip and pinch strength, Purdue Pegboard test, and Jebsen Taylor Hand Function test were measured in the sixth month. Results  A total of 125 patients, 68 females (54.4%) and 57 males (45.6%) were included in the study. The mean age of the patients was 47.15 ± 13.41 (18-65) years. There were 60 patients (48%) in the USF group and 65 patients (52%) in the non-USF group. No significant difference was found in pain, range of motion, Quick-DASH and handgrip and pinch strength between the groups ( p > 0.05). The hand dexterity tests showed no statistically significant difference between the groups in the sixth month ( p > 0.05). Discussion  Hand function can be determined more accurately by assessing hand dexterity. In this study, it is emphasized that concomitant USF does not lead to poorer hand dexterity.

[Surgical treatment of the ulnar styloid process using an angle-stable hook plate in fractures and symptomatic nonunions]

OBJECTIVE

Anatomical reduction of dislocated fractures using an angle-stable hook plate. Surgical revision of symptomatic nonunions with the aim of bone regeneration.

INDICATIONS

Dislocated fractures of the ulnar styloid process with involvement of the ulnar fovea. Combined fractures with instability of the distal radioulnar joint and symptomatic nonunions.

CONTRAINDICATIONS

Undisplaced fractures of the ulnar styloid process and asymptomatic nonunions.

SURGICAL TECHNIQUE

Dorsoradial access to the distal ulna between the 6th extensor tendon compartment and the tendon of the flexor carpi ulnaris muscle. Exposition of the fracture/nonunion. In case of nonunions, excision and freshening of the fracture ends. Reduction is carried out using the hooks of the plate, if necessary additional attachment of autologous cancellous bone in case of nonunions. Fixation of the plate over the gliding hole and subsequent filling of the angular stable screw holes.

POSTOPERATIVE MANAGEMENT

Depending on the accompanying injury, immobilization in a forearm plaster splint for 1-2 weeks. Active movement exercises of the fingers from postoperative day 1, if necessary lymph drainage. After bone development, load build-up under ergotherapy guidance.

RESULTS

Bony healing was achieved in 100% of our cases. The surgical treatment of symptomatic nonunions as well as dislocated fractures of the ulnar styloid process using an angle-stable hook plate has proven to be successful.

Relationship between Fracture of the Ulnar Styloid Process and DRUJ Instability: A Biomechanical Study

Background  There has been clinical question in the treatment of ulnar styloid fracture with distal radius fracture, surgical fixation of the styloid fragment, or ignorance of the fragment. We examined relationship between size of the ulnar styloid fracture and distal radioulnar joint (DRUJ) stability biomechanically to answer the above clinical question. Methods  Changes in the dorsopalmar stiffness of the DRUJ after experimentally simulating in four types of ulnar styloid fractures were examined in cadavers. After tip, middle, base-horizontal, and base-oblique type of styloid fractures were made sequentially, changes in dorsopalmar DRUJ stiffness were measured using the MTS machine in the intact wrist, for each fracture, at 60 degrees pronation, neutral, and 60 degrees supination, respectively. Additional cutting of the radioulnar ligament (RUL) at the fovea was also simulated with the base-horizontal fracture. Results  The tip and middle type fractures did not demonstrate significant loss of stiffness compared with the intact. The base-horizontal fracture demonstrated only significant loss of stiffness in the dorsal direction (radius palmar; ulnar dorsal) with forearm in neutral rotation. The base-oblique fracture demonstrated significant loss of dorsopalmar stiffness of the DRUJ. Additional section of the RUL with the base-horizontal fracture induced significant loss of stiffness of the DRUJ compared with the intact. Conclusions  Because the RUL originates from the fovea as well as from the base of the ulnar styloid, these results suggest that DRUJ instability closely correlates with how much of the bony fragment includes the originating portions of the RUL. The findings further suggest that larger base-oblique and base-horizontal fragments with resultant DRUJ instability must be reattached, but that even base-horizontal fragment as well as tip and middle ulnar styloid fragment can be ignored when there is no instability.

Surgical management of ulnar styloid fractures: comparison of fixation with anchor suture and tension band wire

BACKGROUND

Limited reference is available regarding surgical management in symptomatic ulnar styloid fractures with small bony avulsion. The study goal is to report the surgical outcomes using anchor suture fixation with comparison to traditional tension band wire fixation.

METHODS

We retrospectively reviewed the medical records in patients who underwent surgical repair for unilateral ulnar styloid fractures with distal radioulnar instability between 2004 and 2017. A total of 31 patients were enrolled including two kinds of fixation methods. Anchor suture fixation plus distal radioulnar joint pinning was performed in ten patients with tiny avulsion bony fragments (group A); tension band wire fixation was performed in 21 patients with big styloid fracture fragments (group B). Patient characteristics and 2-year treatment outcomes were compared between two groups based on Mayo Modified Wrist Score (MMWS); Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH); visual analog scale (VAS), and surgical complication. Descriptive statistics were used for calculation of key variables; a p value of < 0.05 was considered statistically significant.

RESULTS

Based on Gaulke classification, there were five subtypes in group A and three subtypes in group B. Incidence of concomitant distal radius fractures was significantly higher in group B; other patient characteristics including age, sex, injury side, and time to surgery showed no significant difference. Outcome assessment regarding MMWS, QuickDASH, and VAS was comparable between two groups. Bone-related complications including nonunion, DRUJ subluxation, and styloid resorption were analyzed; the difference was not significant. Incidence of implant-related complications including migration and secondary removal surgery was significantly higher in group B (p = 0.021).

CONCLUSION

Surgical fixation in symptomatic ulnar styloid fractures yields comparable treatment outcomes in both fracture patterns. Implant-related complication with secondary removal surgery is more common in tension band wire group. Anchor suture fixation is a feasible option for tiny styloid avulsion fragments with limited surgical complication.

Identification of a novel three-column classification for double-column die-punch fractures of the distal radius

The present study aimed to classify double-column die-punch fractures of the distal radius according to imaging data, and to evaluate their clinical features. A retrospective analysis of imaging data derived from 498 patients diagnosed with a double-column die-punch fracture of the distal radius was performed. The fractures were divided into those with middle-column avulsion with fracture of the radial-column articular surface (type I), those with middle-column collapse with fracture of the radial-column articular surface (type II), those with middle-column collapse with fracture of epiphysis of the radial column (type III) or mixed-type fractures (type IV). The intra- and inter-observer consistency between assessors was analyzed with kappa statistics. The patients with double-column die-punch fractures of the distal radius were followed up. There were 21 cases of type I fracture, 135 cases of type II fracture, 130 cases of type III fracture and 212 cases of type IV fracture. The intra-observer kappa coefficient ranged from 0.810–0.861, whereas the inter-observer kappa coefficient range was 0.830–0.876, with high consistency. Following 13 months of follow-up, the patients were assessed for functional recovery of the wrist and hand using the Gartland-Werley scoring system. The analysis indicated that in 95.78% of the patients, wrist function was rated as excellent or good (n=477), while in 4.22% of patients it was rated as fair (n=21), mainly due to the development of post-traumatic arthritis of the wrist following inappropriate therapy. All of the cases were type IV and type III fractures. These data demonstrated the application of a novel classification system named the Three-Column Classification, used to classify double-column die-punch fractures of the distal radius. This method reflected the mechanisms and severity of the fractures, conforming to the principle of AO fracture classification. Furthermore, it exhibited high consistency and may provide reference values for clinical diagnosis, treatment and prognostic evaluation.

Factors associated with the decision for operative versus conservative treatment of displaced distal radius fractures in the elderly

BACKGROUND

The treatment of senile distal radius fractures had not been clearly defined. The objective of this study was to identify the factors associated with the decision for operative treatment of displaced distal radius fractures in patients aged over 55 years.

METHODS

Data of 318 patients with displaced distal radius fractures were collected on patient-, fracture- and surgeon-related characteristics that were plausibly related to the decision for operation. Mean comparisons or chi-squared test were used for univariate analysis of the above-mentioned factors, and then multiple logistic regression was used to identify factors associated with the decision for operation.

RESULTS

Univariate analysis showed that age, osteoporosis, Charlson score, associated orthopaedic injuries requiring surgery, Orthopaedic Trauma Association (AO) and Fernandez classification, radial height, volar tilt, volar/dorsal comminution, ulnar variance, intra-articular displacement/step-off, associated distal radioulnar joint instability or radiocarpal joint dislocation and subspecialty of treating surgeons had statistically significant association with operative intervention. In the multivariate analysis, the predictors of operative intervention were younger patient age (P = 0.028), associated orthopaedic injuries requiring surgery (P = 0.020), higher AO classification (P = 0.037), higher Fernandez classification (P = 0.041), radial shortening >5 mm (P = 0.020), volar tilt > -10° (P = 0.020), volar/dorsal comminution (P = 0.020), ulnar variance >5 mm (P = 0.023), intra-articular displacement/step-off >2 mm (P = 0.004), associated distal radioulnar joint instability or radiocarpal joint dislocation (P = 0.047) and treatment by an upper extremity specialist (P = 0.038).

CONCLUSION

The decision for surgery was predominantly influenced by the characteristics and severity of the fracture. Patients' age and treatment by an upper extremity specialist were also significant factors associated with a higher likelihood of operative intervention.