Base Of Styloid Research Articles

Headless screw fixation of unstable ulnar styloid base fractures after distal radial fractures fixation

Ulnar styloid fractures occur frequently concomitant with distal radial fractures. Although unstable distal radial fractures are mostly surgically treated, ulnar styloid fractures are often ignored. Unstable fractures at the base of the ulnar styloid may lead to persistent ulnar pain, due to distal radioulnar joint instability or ulnar styloid non-union.We retrospectively analyzed a single-surgeon cohort series of surgically treated distal radial fractures on how these concomitant ulnar styloid fractures were regarded: indications for surgery and surgical technique with headless screw fixation.119 surgically treated distal radial fractures were assessed. 51 (42.8%) of the surgically treated distal radial fractures had a distal ulnar fracture, and more specifically 23 (19.3%) had a base fracture of the ulnar styloid. 9 (7.6%) of the wrists had a base fracture of the ulnar styloid which was considered after distal radial fracture fixation as persistently unstable, during distal radioulnar joint ballottement translation test. This fracture subtype was immediately treated with headless screw fixation, resulting in all cases in bony union, with a mean active pronation of 85°, a mean active supination of 80° and a clinical stable distal radioulnar joint, with minimal ulnar pain after 6 weeks (mean Visual Analogue Scale 1). After at least 12 months, persistent pain did not occur and mean QuickDASH was 2.5.According to this single-surgeon cohort series, headless screw fixation provides a reliable treatment for unstable base fractures of the ulnar styloid after distal radial fixation.

Distal Radioulnar Joint Instability in Distal Radius Fractures Managed with Volar Locking Plates

Abstract Introduction: Distal radioulnar joint (DRUJ) injuries are the most common cause of residual wrist disability after fractures of the distal radius. There is a lack of consensus regarding the diagnosis of these injuries along with their management when being accompanied by a fracture of the distal radius. The present prospective study aimed to assess the effect of the involvement of DRUJ on the outcome of distal radius fractures. The study also evaluated the role of clinical and radiographic indices in the diagnosis, management and outcome of these injuries. Materials and Methods: This prospective study involved 51 patients aged >18 years with distal radius fractures treated using volar plating. The intra-operative assessment was done clinically using a piano key or ballotment test after fixation of distal radius fracture using K-wire stabilisation. The mean follow-up was 24 months. The patients were all clinically evaluated using the Modified Gartland and Werley scoring system. Radiographically, we calculated the dorsal/volar tilt, radial inclination, radial height and the ulnar variance. Results: A total of 44 patients with distal radius fractures were managed with the volar plate. The mean age was 45 years (range = 18–77; SD = ±13.6). The majority were men. The maximum cases were found to be of 2R3C type of AO/OTA fractures. Axial instability was observed in 12 cases, with 5 having negative and 7 showing positive axial instability. No statistically significant correlation was identified between the instability of the DRUJ and the overall outcome of distal radius fractures treated with volar plating (P = 0.241). However, a significant association was observed between fractures involving the base of the ulnar styloid (US) and the final clinical outcome (P = 0.023). The mean modified Gartland and Werley score was calculated at 6.09 ± 5.36, and 28.9% of cases suffered from loss of dorsiflexion. Conclusion: The present study revealed that it is important to recognise DRUJ instability in both axial and anteroposterior (AP) planes through clinical and radiological parameters. US base fractures cause DRUJ instability and also create a negative impact on the outcome of distal radius fracture fixed with volar plating. Ulnar variance is a good marker for checking instability in the AP plane by ballotment test. We found that in cases of DRUJ instability, fractures of the ulnar base should be examined and fixed if needed.

Should ulnar styloid be fixed following fixation of a distal radius fracture?,

IntroductionFracture 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. MethodsA 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. ResultsAt 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). ConclusionWhile 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.

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.

The effects of incremental ulnar styloid osteotomies on distal radioulnar joint stability: a biomechanical cadaveric study.

The purpose of this study was to systematically quantify distal radioulnar joint stability with a cadaveric model, using radiographic and joint contact force measurements. Six fresh-frozen cadavers underwent sequential ulnar styloid osteotomies. Posteroanterior and lateral stress radiographs were obtained and joint contact forces and areas were measured. Posteroanterior radiographs showed a significant increase in the distal radioulnar joint gap after osteotomy of the base of the ulnar styloid. Contact force and contact area measurements were not significantly different. We conclude that fractures that involve the ulnar styloid base should be considered for operative fixation when carrying out open reduction and internal fixation of fractures of the distal radius.

Topographical Anatomy of the Distal Ulna Attachment of the Radioulnar Ligament

The deep component of the distal radioulnar ligament provides translational stability and rotational guidance to the forearm. However, controversy exists regarding the importance of this structure as well as the nature of its attachment to the distal ulna. We aimed to evaluate the topographic anatomy of the distal ulna attachment of both the superficial and the deep components of the radioulnar ligament and to assess the relationship between its internal and its external morphometry. Thirteen human distal ulnae attached by ulnar part of the distal radioulnar ligament were scanned using micro-computed tomography and reconstructed in 3 dimensions. In addition, the distal radioulnar ligaments were examined under polarized light microscopy to determine the histological characteristics of collagen contained within the ligaments. The deep limbs have broad marginal insertions at the fovea, whereas the superficial limbs have a circular and condensed insertion to the ulnar styloid. The center of the deep limb was separated from the base of the ulnar styloid by a mean of 2.0 ± 0.76 mm, and this distance was positively correlated with the width of the ulnar styloid. The mean distance between the center of the ulnar head and the center of the fovea was 2.4 ± 0.58 mm. The proportion of collagen type I was lower in the deep limb than in the superficial limb. This new observation of the footprint of the radioulnar ligament in the distal ulna indicates that the deep limb may serve as an internal capsular ligament of the distal radioulnar joint, whereas the superficial limb as the external ligament. Knowledge of the topographic anatomy of the radioulnar ligament's attachment to the distal ulna may provide a better understanding of distal radioulnar ligament-related pathologies.

High-resolution MRI of the ulnar and radial collateral ligaments of the wrist.

Background Accurate diagnosis of injuries to the collateral ligaments of the wrist is technically challenging on MRI. Purpose To investigate usefulness of high-resolution two-dimensional (2D) and isotropic three-dimensional (3D) magnetic resonance imaging (MRI) for identifying and classifying the morphology of the ulnar and radial collateral ligaments (UCL and RCL) of the wrist. Material and Methods Thirty-seven participants were evaluated using 3T coronal 2D and isotropic 3D images by two radiologists independently. The UCL was classified into four types: 1a, narrow attachment to the tip of the ulnar styloid (Tip); 1b, broad attachment to the Tip; 2a, narrow attachment to the medial base of the ulnar styloid (Base); and 2b, broad attachment to the Base. The RCL was also classified into four types: 1a, separate radioscaphoid and scaphotrapezial ligaments (RS + ST) with narrow scaphoid attachment; 1b, RS + ST with broad scaphoid attachment; 2a, continuous radio-scapho-trapezial ligaments (RST) with narrow scaphoid attachment; and 2b, RST with broad scaphoid attachment. The inter-observer reliability of these classifications was calculated. Results Type 1a was the most common of both collateral ligaments. Of UCL classifications, 31.4% were revised after additional review of multiplanar reconstruction (MPR) images from isotropic data. The inter-observer reliability of UCL classification was substantial (k = 0.62) without MPR, and almost perfect (k = 0.84) with MPR. The inter-observer reliability of RCL classification was almost perfect (k = 0.89). Anatomic delineation between the two sequences was not statistically different. Conclusion The UCL and RCL were each identified on high-resolution 2D and isotropic 3D MRI equally well. MPR allows accurate identification of the UCL attachment to the ulnar styloid.

Distal Radius Fracture

Introduction: Distal radius fractures (DRFs) are often accompanied by an associated fracture at the base of the ulnar styloid. The base of the ulnar styloid is an anchor for the deep portion of the Triangular Fibrocartilage Complex (TFCC), which helps to stabilize the distal radio ulnar joint. In our hospital, TFCC injuries and basal ulnar styloid fractures are not primarily operated, but only secondarily in case of symptomatic instability. Objectives: The objective was to test whether the outcome differed between patients with or without a basal ulnar styloid fracture after internal fixation. Methods: Scrutinizing the radiograms of the patients in our prospective register of all DRFs in patients 18 years and older, 65 operated patients were identified having an Arbeitsgemeinschaft für Osteosynthesefragen (AO) type C fracture operated with internal fixation between January 2008 and June 2010. Patients with a simultaneous fracture at the base of the ulnar styloid and patients with unaffected ulnar styloid were invited to a clinical and radiographic examination and evaluated regarding wrist function (Quick Disability of the Arm, Shoulder and Hand [QuickDASH]); Visual Analog Scale (VAS) regarding pain at rest, work, and function; grip strength; range of motion (ROM); and the stability of the distal radio ulnar joint. In all, 45 patients were included; 7 patients declined to participate, and 3 patients could not be reached leaving 35 patients in the study groups. Results: Nineteen patients had a fractured styloid and 16 patients had an intact styloid. The ROM in the ulnar/radial deviation was better (93% vs 79% ( P = .003) in the patients with a fractured styloid compared with the uninjured. There were no differences in QuickDASH, VAS, stability, grip strength, or ROM in supination/pronation or flexion/extension. The mean follow-up time was 27 (15-40) months, and no patients were operated during this time due to distal radio ulnar joint (DRUJ) instability. Conclusion: Fracture at the base of the ulnar styloid did not worsen the outcome of wrist function and pain at medium to long time, in patients with AO type C fracture operated with internal fixation. It thus appears unnecessary to fix a fracture at the base of the ulnar styloid in these patients.

Topographic Anatomy of Distal Radioulnar Ligament Insertion in the Distal Ulna

Background: Insertion of the distal radioulnar ligaments onto the distal ulna is critical to provide translational stability and rotational guidance of the forearm. However, the topographic anatomy of the footprints of these ligaments and their relationships with morphometry of the distal ulna remain unclear. Purpose: We provide a detailed description of the anatomy and the relationships described above in a cadaveric study. Methods: Seventeen human distal ulnas attached by both the superficial and deep limbs of the distal radioulnar ligaments were scanned using micro-computed tomography and reconstructed 3 dimensionally. Results: The deep limbs have narrow marginal insertions just behind the pole of the distal ulna, but the width of the footprint was larger at the fovea than at the peripheral lesion. The superficial limb footprints were the circular and condensed shape. The center of the deep limb was radially distant from the base of the ulnar styloid by a mean of 2.00 ± 0.72 mm, and the distance was positively correlated with the width of the ulnar styloid ( r = .517, P = .030). The mean distance between the center of the ulnar head and the center of the fovea was 2.34 ± 0.62 mm. Conclusions: The deep limb has a narrow marginal insertion just behind the pole of the distal ulna, suggesting its role as the capsular ligament. The center of the fovea is located more radially from the ulnar styloid base. The data provide a better understanding of distal radioulnar ligament-related pathology to perform distal ulnar fixation or ligament repair to recover distal radioulnar joint stability.

Treatment of symptomatic non-unions of the base of the ulnar styloid with plate osteosynthesis.

Therapeutic IV.

Fixing fractures of the ulnar styloid in distal radius fractures

The majority of distal radius fractures are associated with an ulnar styloid fracture [1-3]. There is solid evidence in the literature that this association may ultimately affect the clinical outcome causing instability, disability, and pain in the distal radioulnar joint (DRUJ) [2,4-7]. The main reasons for the worse outcome are: (1) DRUJ instability, (2) impingement with the triquetrum, and (3) Extensor Carpi Ulnaris (ECU) tenosynovitis. Because of its close association with the Triangular Fibrocartilage Complex (TFCC), fractures of the ulnar styloid might indicate possible TFCC disruption with subsequent DRUJ instability [4,8,9]. Studies on the clinical relevance of ulnar styloid fractures have produced conflicting results. However, when considering size and displacement of the fracture, May et al [2] found that, after distal radius fracture stabilization, a fracture through the base of the ulnar styloid that involves most part of the TFCC attachment and stays in a deviated more radial position (2 mm or more) indicates DRUJ instability. In an ulnar styloid fracture model, Shaw et al [4] found that K-wire fixation of the ulnar styloid fracture restored stability to the DRUJ regardless the integrity of other supporting structures. Bone fragments resulting from non-union could also provoke irritation and pain [5,10] due to impingement with the triquetrum [11]. Twenty-six percent of ulnar styloid fractures develop non-union [12]. From those, just a few becomes symptomatic [5]. If the DRUJ is stable, simple removal of the fragment usually solves the problem [5,11]. Extensor carpi ulnaris tendon impingement caused by malalignment of a fibrous nonunion may also be responsible for a poor clinical outcome. [13,14]. This condition is rarely found after a distal radius fracture and it is successfully treated with excision of the bony prominence and reconstruction of the floor of the sixth compartment. Hence, fixation of a small sized ulnar styloid in the acute setting of a distal radius fracture is probably unnecessary. As the results of treatment of chronic instability of DRUJ following a distal radius fracture are more unpredictable [4], it is advisable to take all measures in the acute setting to prevent this complication. Therefore, fixation of the ulnar styloid is indicated when there are large sized fragments that persist deviated after stabilization of the radius or when the distal radioulnar joint is grossly unstable. Immobilization with a sugar tong splint for four weeks or until proper healing is necessary when the surgeon chooses not to fix a reduced ulnar styloid large fragment that is acceptably reduced.

Triangular fibrocartilage complex injury accompanied by distal radius fracture

Triangular fibrocartilage complex injury accompanied by distal radius fracture

Anatomy and Clinical Relevance of the Ulnocarpal Ligament

Anatomy and Clinical Relevance of the Ulnocarpal Ligament

Fracture articulaire du radius distal avec fragment de fossette lunarienne retourné, à propos de 4 cas : intérêt du traitement chirurgical par voie antéro-médiale

IntroductionIntra-articular distal radial fractures in young subjects occur in severe trauma. Articular reduction needs to be anatomical. We report four cases with the particularity of having a 90° or 180° rotated lunate fossa. Our goal is to bring out the positive aspects of surgical procedure by volar medial approach and to assess long-term functionnal and radiological results. Material and methodsOur study focused on four men whose average age was 27 (age range from 19 to 43). The fractures were type IV according to Melone's classification. The associated lesions included: one fracture of the base of the ulnar styloid, one fracture of the distal quarter of the ulnar diaphysis and one scapho-lunate diastasis. We used a volar medial approach between the flexors tendons and the ulnar bundle in order to pin the fragment of lunate fossa. The rest of the radial epiphysis was pinned after a 5mm skin incision. In two cases, this pinning was complemented with a brachial-antebrachial-palmar cast and in the other two cases with an external fixator. ResultsThe follow-up period averaged 68.8 (18 to 115) months, all the patients were clinically examined through antero-posterior, lateral and dynamic X-rays. The objective results assessed according to Green and O’Brien's criteria, later modified by Cooney, were as follows: two very good, one good, one average. The X-rays showed consolidated fractures. According to Knirk and Jupiter's classification of arthritis, we had three grades 0, one of which showed a subchondral sclerosis of the lunate fossa, and one grade 3. Discussion and conclusionImaging with simple radiographs is not sufficient and needs to be complemented with CT scan. Our approach allows for direct access to the fragment of the lunate fossa and easier visualization of the distal radioulnar, compared to Henry's approach, thereby avoiding excessive traction of the median nerve. Type d’étudeNiveau IV.

THE BEAUTY OF STABILITY: DISTAL RADIOULNAR JOINT STABILITY IN ARTHROSCOPIC TRIANGULAR FIBROCARTILAGE COMPLEX REPAIR

The triangular fibrocartilage complex (TFCC) has an important role in the stability of the distal radioulnar joint (DRUJ) stability. We designed a new method of TFCC tear repair that has satisfactory post-operative DRUJ stability. From May 2004 to August 2010, 14 patients who underwent this operation were reviewed. The average post-operative follow-up period was 8.2 months; 66.7% of the patients with TFCC tear in sigmoid notch had clinical DRUJ instability, while only 50% of tear in fovea and 16.7% of tear in base of ulnar styloid had clinical DRUJ instability. Transosseous suture via inside-outside technique was used for repair. At the final follow-up, all 14 patients have soft end point with < 5 mm translations of the DRUJ shown by the stress test. Based on this small sample with satisfactory outcome assessed by the Mayo modified wrist score and DRUJ stability, we recommend TFCC tear in sigmoid notch, which has a higher chance of DRUJ instability, to be repaired by transosseous suture.

Isokinetic study of the impact of styloid fracture with a volar plate osteosynthesis on pronosupination strength

styloid; – group 2: patients without fracture of the ulnar styloid or just a tip fracture. A control group (Group 3) was composed of six healthy patients without history of trauma of the wrist. All the patients were tested bilaterally for isokinetic and isometric pronation and supination strength. Clinical outcomes such as grip strength, range of motion, Mayo Clinic Wrist score (MWS), DASH score and Lidstrom classification were evaluated by an independent observer and correlated with isokinetic results. Statistical analysis was performed with Kruskall-Wallis test and Wilcoxon test (P < 0.05). Results.– There were no significant differences in range of motion; grip strength; MWS and DASH scores and isometric strength of pronation and supination. Isokinetic evaluation showed a significant decrease of the supination strength between group 1 compared to group 2 and 3 at 458/s (P < 0.01). Discussion.– This study suggests that fracture of the base of the ulnar styloid has no effect on upper extremity specific questionnaires. However, a significant decrease in isokinetic supination force is expected. More specific health questionnaires may confirm the clinical effect of this loss of strength. Consequently, more aggressive treatment for the ulnar styloid may be proposed in case of fracture of the radius associated with ulna in young and active patients.

Patterns of triangular fibrocartilage complex (TFCC) injury associated with severely dorsally displaced extra-articular distal radius fractures

The aim of the study was to examine triangular fibrocartilage (TFCC) injury patterns associated with unstable, extra-articular dorsally displaced distal radius fractures. Twenty adult patients with an Arbeitsgemeinschaft für Osteosynthesefragen (AO), type A2 or A3, distal radius fracture with an initial dorsal angulation greater than 20° were included. Nine had a tip fracture (distal to the base) of the ulnar styloid and 11 had no such fracture. They were all openly explored from an ulnopalmar approach and TFCC injuries were documented. Eleven patients also underwent arthroscopy and intra-articular pathology was recorded. All patients had TFCC lesions of varying severity, having an extensor carpi ulnaris subsheath avulsion in common. Eighteen out of 20 also displayed deep foveal radioulnar ligament lesions, with decreasingly dorsal fibres remaining. The extent of this foveal injury could not be appreciated by radiocarpal arthroscopy. Severe displacement of an extra-articular radius fracture suggests an ulnar-sided ligament injury to the TFCC. The observed lesions concur with findings in a previous cadaver study. The lesions follow a distinct pattern affecting both radioulnar as well as ulnocarpal stabilisers.

Wrist Arthrodesis for Brachial Plexus Palsy Using an External Fixator and a Cannulated Screw (Ioannina Technique)

To present a new technique for wrist arthrodesis and review its treatment outcomes in 33 patients with brachial plexus palsy. 26 men and 7 women (mean age, 26 years) with global brachial plexus palsy underwent wrist arthrodesis using an external fixator and a cannulated screw. All surgeries were performed under local anaesthesia by a single senior surgeon. An external fixator was applied to the radius and the metacarpal of the index finger. The articular surfaces of the radius, scaphoid, lunate, and capitate were debrided, and a cannulated screw inserted from the base of the radial styloid to the carpo-metacarpal joint of the ring finger. Cancellous allografts mixed with demineralised bone matrix were added to the decorticated wrist bones. The external fixator was removed at week 8 and the wrist protected with a short-arm splint until solid wrist fusion. All patients achieved wrist fusion after a mean of 14 (range, 12-16) weeks. Two patients had delayed fusion and slight wrist instability, because the shorter screw was embedded in the cancellous bone and not self-tapped to the cortex. Fusion was achieved after replacement with a longer screw. No patient developed a superficial or deep wound infection; 2 developed pin track infections. All patients were satisfied with the outcome and able to perform simple daily activities after one year. Our new technique for wrist arthrodesis is less invasive. Blood loss, the risk of postoperative infection, and adhesions at the extensors are decreased.

Should an Ulnar Styloid Fracture Be Fixed Following Volar Plate Fixation of a Distal Radial Fracture?

Ulnar styloid fractures often occur in association with distal radial fractures. The purpose of this study was to determine whether an associated ulnar styloid fracture following stable fixation of a distal radial fracture has any effect on wrist function or on the development of chronic distal radioulnar joint instability. One hundred and thirty-eight consecutive patients who underwent surgical treatment of an unstable distal radial fracture were included in this study. During surgery, none of the accompanying ulnar styloid fractures were internally fixed. Patients were divided into nonfracture, nonbase fracture, and base fracture groups, on the basis of the location of the ulnar styloid fracture, and into nonfracture, minimally displaced (< or =2 mm), and considerably displaced (>2 mm) groups, according to the amount of ulnar styloid fracture displacement at the time of injury. Postoperative evaluation included measurement of grip strength and wrist range of motion; calculation of the modified Mayo wrist score and Disabilities of the Arm, Shoulder and Hand score; as well as testing for instability of the distal radioulnar joint at a mean of nineteen months postoperatively. Ulnar styloid fractures were present in seventy-six (55%) of the 138 patients. Forty-seven (62%) involved the nonbase portion of the ulnar styloid and twenty-nine (38%) involved the base of the ulnar styloid. Thirty-four (45%) were minimally displaced, and forty-two (55%) were considerably (>2 mm) displaced. We did not find a significant relationship between wrist functional outcomes and ulnar styloid fracture level or the amount of displacement. Chronic instability of the distal radioulnar joint occurred in two wrists (1.4%). An accompanying ulnar styloid fracture in patients with stable fixation of a distal radial fracture has no apparent adverse effect on wrist function or stability of the distal radioulnar joint.

Effect of an Unrepaired Fracture of the Ulnar Styloid Base on Outcome After Plate-and-Screw Fixation of a Distal Radial Fracture

The impact of an unrepaired fracture of the ulnar styloid base on recovery after internal fixation of a fracture of the distal part of the radius is uncertain. We evaluated a series of patients with an internally fixed fracture of the distal part of the radius to test the hypothesis that there is no difference in wrist motion or function scores between those with an untreated fracture of the ulnar styloid base and those with no ulnar fracture. Two cohorts of seventy-six matched patients, one with a fracture of the ulnar styloid base and the other with no ulnar fracture, were retrospectively analyzed by examining data gathered in a prospective study of plate-and-screw fixation of distal radial fractures. Patients were matched for age, sex, AO fracture type, and injury mechanism. The two cohorts were analyzed for differences in motion, grip strength, pain, the Gartland and Werley score, the DASH (Disabilities of the Arm, Shoulder and Hand) score, and the SF-36 (Short Form-36) score at six, twelve, and twenty-four months postoperatively. In a second analysis, sixty-four patients with <2 mm of displacement of a fracture of the ulnar styloid base were compared with forty-nine patients with greater displacement. Differences between cohorts and within cohorts over time were determined with use of regression analysis and the likelihood ratio test. No significant differences were found between patients with an unrepaired fracture of the ulnar styloid base and those with no ulnar fracture at any of the follow-up intervals. However, a trend was observed toward less grip strength at six months (71% [of that on the contralateral side] compared with 79%; mean difference, -8% [95% confidence interval=-15.3% to -0.6%]; p=0.03) and less flexion (54 degrees compared with 59 degrees ; mean difference, -5 degrees [95% confidence interval=-11.7 degrees to -0.8 degrees ]; p=0.02) and ulnar deviation (32 degrees compared with 36 degrees ; mean difference, -4 degrees [95% confidence interval=-7 degrees to -0.1 degrees ]; p=0.05) at twenty-four months after surgery in patients with an untreated fracture of the ulnar styloid base. There were no significant differences with regard to any tested outcome measure between the patients with >or=2 mm of displacement of an unrepaired fracture of the ulnar styloid base and those with less displacement. An unrepaired fracture of the base of the ulnar styloid does not appear to influence function or outcome after treatment of a distal radial fracture with plate-and-screw fixation, even when the ulnar fracture was initially displaced >or=2 mm.