Classification and treatment of ulnar styloid nonunion

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.

Treatment of type II symptomatic ulnar styloid nonunions with reinsertion of the triangular fibrocartilage complex

PURPOSE

The purpose of this retrospective study was to introduce an alternative technique for the treatment of type II symptomatic ulnar styloid nonunion by the reinsertion of the triangular fibrocartilage complex and the ulnar collateral ligament.

METHODS

Between March 2009 and May 2017, 45 patients (34 males and 11 females) suffering from the nonunion of type II ulnar styloid fractures all underwent the subperiosteal resection of the avulsed fragments and the reinsertion of the TFCC and ulnar collateral ligament. Outcome assessments included the ranges of motion of the wrist, grip strength, pain, and Mayo wrist score. The preoperative and postoperative parameters were compared. A P-value less than 0.05 was considered to be statistically significant.

RESULT

The mean follow-up period was 21.66 ± 7.93 months (range, 12 to 26 months). At the final follow-up, the mean preoperative flexion and extension were 79.32 ± 4.52° and 74.40 ± 4.36° respectively. The mean preoperative pain score, grip strength, and Mayo wrist score were 32.48 ± 4.00; 23.88 ± 8.38 kg, and 77.72 ± 8.31 respectively. The mean postoperative flexion and extension of the wrist were 80.56 ± 6.32° and 75.43 ± 3.12° respectively. The mean postoperative pain score, grip strength, and Mayo wrist score were 12.41 ± 3.27, 26.31 ± 8.30 kg, and 90.71 ± 7.97 respectively. There were significant differences in pain, grip strength, and Mayo wrist score (P < 0.05), but no significant differences concerning the range of motion of the wrist.

CONCLUSION

In the treatment of the nonunion of type II ulnar styloid fractures, the resection of the avulsed fragments followed by the reinsertion of the TFCC and the ulnar collateral ligament with an anchor was a reliable alternative technique, bringing the satisfactory function of the wrist.

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.

Fixed Subluxation of the Distal Radioulnar Joint following Malunion of the Ulnar Styloid Process

Purpose  Recent literature on significance and treatment of ulnar styloid fractures suggest that the ulnar styloid is not the central problem but the radioulnar ligaments and their impact on joint stability. However, specifically displaced ulnar styloid process fractures that secondarily heal in an ectopic position remain a rare situation for which diagnostics and treatment options remain a topic of discussion. Methods  This case series presents four patients with limited supination due to a fixed dorsal subluxation of the distal radioulnar joint (DRUJ). The reason here fore was a significant malunion of ulnar styloid fracture that was addressed by corrective ulnar styloid osteotomy. Three of these osteotomies used three-dimensional (3D) preoperative planning and patient specific guides. Results  All patients presented with a significant displacement of the malunited ulnar styloid fracture (average 32-degree rotation and 5-mm translation). In all four patients, the fixed subluxation of the ulnar head was resolved clinically and radiographically, and the forearm rotation restored after corrective osteotomy of the ulnar styloid and fixation in an anatomical position. Conclusion  This case series presents a very specific subset of patients with nonanatomically healed ulnar styloid fractures responsible for a chronic DRUJ dislocation and limited prosupination and its treatment. Level of evidence  This is a Level IV, therapeutic study.

Relationship of ulna styloid fracture to the distal radio-ulnar joint stability. A clinical, functional, and radiographic outcome study

BACKGROUND

Ulna styloid fracture occurs approximately about 55% of all distal end of radius fractures. However, the clinical and functional outcome of these fractures remains indefinite.

RESULTS

Only 56 patients with distal radius fractures had concomitant ulna styloid fractures. The mean age was 32 years (range: 18-69; SD: ± 12.7). The majority were men. The mean time from injury was 18.7 months (range: 6-84; SD: ± 13.3). The most common was Frykman 2, followed by 6, type 8, and type 4. All were closed fractures; 60.7% were base, and 39.3% were tip fractures. 50% were treated with casting, 48.3% plating, and 1.8% external fixation. The mean period of casting was 7.67 weeks (range: 4-16; SD ± 3.1). The ulna styloid was united in 35.7%. There is no significant difference in the range of movement between those with ulna styloid union and non-union. The Ballottement test and Piano key sign was statistically insignificant between both groups. All the displacements were dorsal except in 1 case. The mean displacement of ulna styloid is 1.88mm (SD±1.08, Range: 0.20-4.60mm). The mean VAS score at rest and work is not statistically significant. The mean grip strength and functional score (DASH) are similar in both groups.

CONCLUSION

Ulna styloid fractures do not contribute to the DRUJ instability and the status of the union of the ulna styloid and the site of the ulna styloid fracture (tip or base) did not have a bearing on the range of movement and functional status of the affected wrist. Temporary DRUJ immobilization might allow TFCC recovery.

Treatment with Buttress Plate Technique for Symptomatic Ulnar Styloid Base Nonunion

Background  Surgical treatment options for symptomatic ulnar styloid base nonunion can be divided into two groups: styloid excision and styloid fixation methods. Styloid fixation is commonly performed using tension band wiring or distal ulna hook plate. However, these methods are more suitable for large styloids than small ones. For this reason, fixation of small styloids still remains a problem. Purpose  To present the surgical details and results of patients operated using the buttress plate technique, due to the symptomatic ulnar styloid base nonunion. Patients and Methods  In this study, 11 patients who underwent surgery for symptomatic ulnar styloid base nonunion using buttress plate technique were evaluated retrospectively. The patients were evaluated with the help of forearm and wrist range of motion, grip strength, disabilities of the arm, shoulder, and hand (DASH) score and visual analogue pain score. Results  The mean follow-up period was 15 months (range: 13-21 months). Union was achieved in 10 patients. At the final follow-up, the forearm supination and pronation active range of motions were significantly higher than those in the preoperative period, the visual analogue pain score mean value was 0.7 (range: 0-5), and the DASH score mean value was 7 (range: 1-32). Conclusion  We conclude that good results can be achieved with the buttress plate technique in patients with both large and small fragmented ulnar styloid base nonunions and no distal radioulnar joint instability. Level of Evidence  This is a Level IV, therapeutic study.

Open Foveal Repair of the Triangular Fibrocartilage Complex Tears Associated with Symptomatic Ulnar Styloid Non-union

Background: Symptomatic ulnar styloid non-union can be treated by excision of the ulnar styloid fragment. For combined triangular fibrocartilage complex (TFCC) tears, several repair techniques such as arthroscopic repair, open repair to the fracture site or reconstruction using a tendon graft have been introduced. This study reports the technique and outcomes of open foveal repair of the TFCC with excision of the ulnar styloid fragment in patients with symptomatic ulnar styloid non-union and distal radioulnar joint (DRUJ) instability. Methods: Consecutive patients with symptomatic ulnar styloid non-union with TFCC tears and DRUJ instability who underwent excision of the ulnar styloid fragment and open foveal repair of the TFCC were retrospectively reviewed. After excising the ulnar styloid fragment, a capsular window was created between the triquetrum and TFCC, followed by attaching the TFCC to the fovea using three sutures through a bone tunnel from the ulnar cortex to the fovea. Additional ulnar shortening osteotomies were performed in patients with positive ulnar variance and ulnar impaction test. The outcomes were evaluated in terms of DRUJ stability and the Quick Disabilities of the Arm, Shoulder and Hand (DASH) scores. Results: In total, 21 patients with a mean age of 40 were enrolled in the study. All patients demonstrated DRUJ stability at a mean follow-up duration of 14 months. The mean Quick DASH score significantly improved from 18.9 ± 11.7 to 2.5 ± 4.1 (p < 0.05). Eleven patients underwent combined ulnar shortening osteotomies, and no difference in the Quick DASH score was found between patients who underwent ulnar shortening osteotomy and those who did not. Conclusions: This study demonstrates that open foveal repair of the TFCC with ulnar styloid fragment excision is an effective strategy to surgically treat patients with symptomatic ulnar styloid non-union with TFCC tear and DRUJ instability. Level of Evidence: Level III (Therapeutic).

Triangular Fibrocartilage Complex Injuries in Children and Adolescents

Triangular fibrocartilage complex (TFCC) tears can cause ulnar-sided wrist pain in children and adolescents following acute rotational injury or prior distal radius fracture. Surgical treatment, guided by the Palmer classification, is considered after activity modification and occupational therapy. All concomitant wrist pathologies, such as distal radioulnar joint instability, ulnocarpal impaction, and distal radius malunion, must be recognized and addressed at the time of TFCC debridement or repair. This article reviews recent literature guiding clinical evaluation and surgical treatment of children and adolescents with TFCC injuries. The authors' techniques for arthroscopic-assisted outside-in repair of Palmer 1B and 1D tears are described.

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.

[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.

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.

Management of Acute Distal Radioulnar Joint Instability Following a Distal Radius Fracture: A Systematic Review and Meta-Analysis

Purpose

We sought to review the clinical outcomes of conservative and operative treatment options for acute distal radioulnar joint (DRUJ) instability associated with distal radius fractures in adult patients.

Methods

A systematic search of PubMed, MEDLINE, and EMBASE for articles published between 1990 and 2020 involving DRUJ instability associated with distal radius fractures was performed. The primary outcomes analyzed included clinical grip strength; range of motion; the disability of the arm, shoulder and hand (DASH) score; and the modified Mayo wrist score (MMWS).

Results

Of the 531 articles identified in the literature search, 8 met our defined criteria and were included in the final analysis. The cumulative sample size was 258 patients at a mean follow-up of 11.1 months (range, 3–16.9 months). Treatment groups included cast immobilization in supination, K-wire stabilization, and triangular fibrocartilage complex (TFCC) repair. Statistical analysis revealed no difference across groups in active flexion-extension or DASH scores. A significant decrease in grip strength was found in patients who underwent TFCC repair compared with that in those who underwent both cast immobilization (P = .04) and K-wire stabilization (P = .02). Furthermore, we found a significant decrease in active pronation-supination between patients who underwent TFCC repair and those who underwent cast immobilization (P = .03). Patients who underwent TFCC repair were also found to exhibit decreased MMWS as compared with those who underwent K-wire stabilization (P = .05). Overall, persistent DRUJ instability was only found in 4 patients (1.5%), without a significant difference between treatment groups.

Conclusions

This study suggests functional advantages of certain treatment modalities over others, with the range of motion being highest in patients who underwent cast immobilization and grip strength being highest in patients who underwent K-wire stabilization. However, the mean DASH scores showed no difference across all groups, calling into question the clinical need to pursue operative treatment via K-wire stabilization or TFCC repair over conservative treatment via cast immobilization. This study will hopefully serve as a foundation for future prospective studies to help improve and standardize treatment algorithms in patients with DRUJ instability and distal radius fractures.

Type of study/level of evidence: Therapeutic II.

[Osseous variations in radiological diagnostics of the wrist]

CLINICAL/METHODICAL ISSUE

The carpal joint is one of the most complex joints in the body comprising multiple bones that allow flexibility while simultaneously providing stability. Variations in osseous structures that may be either cause or result of pathological changes may make radiological reporting challenging. Only the knowledge of important osseous variations allows a reliable assessment of carpal imaging studies.

STANDARD RADIOLOGICAL METHODS

The standard imaging technique for evaluation of osseous carpal structures is conventional radiography, which is followed by computed tomography (CT) and-under special circumstances-magnetic resonance imaging (MRI). Other imaging methods such as sonography or nuclear medicine studies do not play a significant role in clinical routine.

METHODICAL INNOVATIONS

Apart from continuous reduction in effective radiation dose, there have been no significant methodical improvements in the past decade regarding imaging of osseous carpal structures in clinical routine.

PRACTICAL RECOMMENDATIONS

As the initial diagnostic procedure, conventional radiography usually allows a safe and reliable diagnosis of osseous structures. Unclear or discrepant imaging findings between clinical and imaging assessment should initiate further imaging, preferably with CT. Only for certain questions or to reduce effective radiation dose in children MRI studies should be performed in clinical routine.

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.

Factors predictive for union of basal fracture of the ulnar styloid process after distal radial fracture fixation using a volar locking plate

BACKGROUND

Some basal ulnar styloid fractures (USFs) achieve union without surgical fixation when accompanying distal radius fractures (DRFs) are treated via placement of volar locking plates (VLPs). The purpose of this study was to seek factors predictive of such healing through the retrospective case-control study.

METHODS

We evaluated 203 patients who received VLPs to treat DRFs in our institute from March 2010 to February 2018; Group 1 contained "union" patients and Group 2 contained "nonunion" patients. Basic demographic, radiological, and operative variables were compared. At the final follow-up (at least 2 years postoperatively), pain was scored using a visual analog scale (VAS). Scores on the Disabilities of the Arm, Shoulder, and Hand (DASH) instrument; grip strengths; and demerit points of the Gartland and Werley system were compared between groups.

RESULTS

Group 1 consisted of 58 patients and Group 2 consisted of 147 patients. Univariate analysis showed that age, bone mineral density (BMD), and Gaulke USF classification significantly differed between groups (all p < 0.05). Multivariate analysis showed that BMD (p < 0.001, odds ratio [OR] = 0.214, 95% confidence interval [95% CI] = 0.126-0.363) and Gaulke classification (p < .001, OR = 0.092, 95% CI = 0.034-0.250) were significantly associated with USF union, which was significantly higher in patients with mean BMD ≥ -0.12 (the cutoff value) and type IIC USFs. However, postoperative clinical outcomes at the final follow-up did not differ significantly between groups (all p > 0.05).

CONCLUSIONS

Approximately 30% (58/205) of basal USFs associated with DRFs united after VLPs alone were placed to treat the DRFs. BMD ≥ -0.12 independently predicted union. Type IIC USFs exhibited more union than other fracture types. Additional surgical fixation of a basal USF accompanied by a DRF treated via VLP placement may be unnecessary, especially if BMD is good and fracture type is IIC.

LEVEL OF EVIDENCE

Level III, Case-control study.

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.

[Effects of ulnar styloid and sigmoid notch fractures on postoperative wrist function of patients with distal radius fracture]

OBJECTIVE

To study the effects of ulnar styloid and sigmoid notch fractures on postoperative wrist function in patients with distal radius fracture.

METHODS

In total, 139 patients treated for distal radius fracture in the Department of Orthopedic Trauma at Peking University People's Hospital from Jan. 2006 to June 2016 were selected for outpatient follow-ups. Evaluation was based on Sartiento's modification of the Gartland and Werley scores. Efficacy was assessed with wrist pain as the focus.

RESULTS

The excellent and good efficacy rate was 97.1% (excellent: n=107, 77.0%; good: n=28, 19.4%; and fair: n=4, 2.9%). Gender, age, and whether the ulnar styloid fracture achieved union did not significantly impact the scores (P>0.05). The scores of the basal fracture group were significantly different (P=0.001). Internal fixation of ulnar styloid fracture was associated with a significant difference in scores (P=0.005). The effect of sigmoid notch fracture was also associated with a significant difference in scores (P=0.024). This study included 22 cases of ulnar wrist pain, and the overall incidence of ulnar wrist pain was 15.8%. Gender, age, whether the ulnar styloid fracture achieved union, and whether internal fixation was conducted for ulnar styloid fracture and sigmoid notch fracture had no significant effect on the occurrence of ulnar wrist pain (P>0.05). The incidence of ulnar wrist pain was higher in basal fractures than that in tip fractures. Among ulnar styloid fractures, the union rate of basal fracture was higher than that of tip fractures. The union rates of basal fracture and tip fracture were significantly different (P<0.001). Basal fractures were significant risk factors for ulnar wrist pain (P=0.028). Basal fracture of the ulnar styloid group and sigmoid notch fracture group had poor wrist function scores. Wrist function score improved significantly after internal fixation of ulnar styloid fracture. The incidence of ulnar wrist pain was higher in basal fracture group. The union rate in basal fracture group was higher than in tip fracture group.

CONCLUSION

The overall effect of surgical treatment of distal radius fracture is satisfactory. Ulnar styloid basal fracture and sigmoid notch fracture are risk factors for postoperative wrist dysfunction in patients with distal radius fracture, and the basal fracture is one of the risk factors of ulnar wrist pain. The union rate of ulnar styloid basal fractures is better than that of tip fractures. Internal fixation of ulnar styloid fracture can improve wrist function.

Impact of Ulnar Styloid Fractures on the Treatment Effect of Distal Radius Fractures with Volar Plate Fixation: A Case Control Study

BACKGROUND

There is a controversy regarding whether ulnar styloid fractures affect the efficacy of treatment of distal radial fractures. The purpose of this study was to investigate whether ulnar styloid fractures impact wrist joint function in patients without distal radioulnar joint instability, after distal radial fracture fixation using a volar plate.

MATERIALS AND METHODS

Seventy-five patients with a distal radial fracture were treated using a volar plate between February 2010 and February 2016 (33 men and 42 women; mean age 40.9 ± 9.4 years). Forty-four patients had ulnar styloid fractures (Group A) and 31 patients did not (Group B). There were no differences between the two groups with regard to sex, age, course of the disease and fracture type (P > 0.05).

RESULTS

The mean follow-up time was 21 months. There were no differences between the groups in palmar tilt, radial inclination and radial length when the distal radial fractures had healed (P > 0.05). At the final follow-up visit, the two groups were similar in terms of wrist motion range, and grip and pinch strength (P > 0.05). The Gartland-Werley scores were 13 for excellent, 26 for good, 3 for fair and 2 for poor (excellence rate 89%) for Group A, and 10 for excellent, 17 for good, 2 for fair and 2 for poor (excellence rate 87%) for Group B. The difference between the two groups was not significant (Z = - 0.097, P = 0.922).

CONCLUSION

After open reduction and plate fixation of distal radial fractures, if stability of the distal radioulnar joint is achieved, untreated ulnar styloid fractures have no impact on wrist joint function.

Early and late fixation of ulnar styloid base fractures yields different outcomes

Background

The role of surgical fixation of ulnar styloid fractures remains a subject of debate. The purpose of this study was to compare the surgical outcomes following early and late intervention.

Methods

We retrospectively reviewed 28 patients who underwent surgical repair for unilateral ulnar styloid fractures with distal radioulnar instability between 2004 and 2014. Surgical fixation was performed within 3 months of injury in 13 patients (group A) and beyond 3 months in 15 patients (group B). Patient characteristics and functional outcomes were compared between the two groups. The outcome survey consisted of QuickDASH score, grip strength, range of motion, pain score based on the visual analog scale, and surgical complications. Descriptive statistics were calculated for key variables. A p value of < 0.01 was considered statistically significant.

Results

Patient characteristics including age, sex, injured side, dominant side injury, and concomitant distal radius fracture showed no significant differences between the two groups. Time to surgery averaged 1.1 months in group A and 12.3 months in group B. Significantly better outcomes were found in group A than in group B, including QuickDASH scores (4.4 ± 5.9 vs. 12.9 ± 9.9) and grip strength (37.4 ± 5.1 vs. 29.1 ± 5.9 kg). Significantly better range of motion was found in group A than in group B with respect to supination (81.9° ± 4.3° vs. 75° ± 8.5°), extension (84.6 ± 4.3 vs. 76.7 ± 6.5), and flexion (80.4° ± 3.8° vs. 72° ± 4.1°). The difference was not significant in case of pronation (78.8° ± 3° vs. 74.3° ± 5.9°) and with respect to pain scores (0.6 ± 0.7 vs. 1.3 ± 1).

Conclusion

Both osseous and soft tissue lesions need to be fully addressed in ulnar styloid fractures. Early detection and surgical repair yielded better outcomes. Higher complication rates in late-treated fractures show that surgeons should select surgical candidates and modalities properly.

Anthropometric and clinical analysis of the distal ulna and extensor carpi ulnaris tendon using MRI

OBJECTIVE

To investigate the ulnar groove (UG), extensor carpi ulnaris (ECU) tendon, and ulnar styloid process (USP) parameters in asymptomatic individuals without ulnar-sided wrist abnormalities, to determine whether these values can be anthropometric markers of age and gender and identify their correlations for use in clinical decision-making.

MATERIALS AND METHODS

The MRI T1W axial, T2W sagittal, coronal PW and DESS sequences were evaluated in 100 cases (62 women). The UG width, depth and groove opening angle (GOA), ECU tendon width and thickness, and USP base width and length were measured.

RESULTS

For gender, the cut-off, sensitivity, specificity and accuracy values were 8.58 mm, 67, 68 and 66%, respectively, for UG width; 5.3 mm, 53, 68 and 62%, respectively, for ECU width; and 6.4 mm, 55, 74, and 67%, respectively, for USP length. There was no difference concerning age. The tendon width was 63% of the UG width and depth was approximately 51% out of the UG. UG depth was correlated with GOA and tendon thickness (p < 0.001 and 0.03, respectively); UG width with GOA, tendon thickness, and USP base width and length (p = 0.005, 0.01, 0.016, and 0.02, respectively); tendon width-thickness with USP base width and length (p = 0.05); and US base width with US length (p < 0.001).

CONCLUSION

The gender differences in distal ulnar measurements can be beneficial for surgery and forensic science. UG is wider than ECU tendon, and this is the cause of normal subluxation. Therefore, rather than deepening UG, surgeons should focus on tendon sheath abnormalities as a physiological solution.

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.

Functional outcomes of distal radius fractures with and without ulnar styloid fractures: a meta-analysis

The aim of this meta-analysis was to compare the functional outcomes of patients with a distal radius fracture with and without a concomitant fracture of the ulnar styloid process. A systematic literature search was performed to identify all studies comparing patients with a distal radius fracture with and without an ulnar styloid process fracture. The initial search revealed 511 articles, of which 12 articles with a total of 2243 patients were included; 1196 patients with and 1047 patients without an ulnar styloid process fracture. A statistically significant mean difference of 3.40 points (95% CI 1.33-5.48) in the Disability of the Arm, Shoulder, and Hand score was found in favour of patients without an ulnar styloid process fracture. This difference is less than 10 and therefore not clinically important. No significant difference was found in Patient-Rated Wrist Evaluation scores, range of motion, grip strength, visual analogue scale pain scores, ulnar-sided wrist pain and distal radio-ulnar joint instability between patients with and without an ulnar styloid process fracture after 1 year of follow-up. Moreover, no significant differences were found between ulnar styloid base and nonbase fractures.

LEVEL OF EVIDENCE

I.

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.

Arthroscopic Management of Ulnocarpal Impaction Syndrome and Ulnar Styloid Impaction Syndrome

Both ulnocarpal impaction syndrome and ulnar styloid impaction syndrome can produce ulnar wrist pain. The definition and clinical differentiation are explained. The relevant anatomy, biomechanics, causes, diagnosis, and arthroscopic treatments, as well as the surgical indications, techniques, and outcomes of these syndromes are discussed in detail.

Does concomitant ulnar styloid fracture and distal radius fracture portend poorer outcomes? A meta-analysis of comparative studies

PURPOSE

An ulnar styloid fracture often occur in association with a distal radial fracture. Whether an ulnar styloid fracture interfere with the results of a distal radial fracture still remains controversial. The aim of this study was to analyse the effects of an accompanying ulnar styloid fracture on clinical outcomes in patients with distal radial fractures.

METHODS

A meta-analysis of published studies comparing outcomes of distal radial fractures with an ulnar styloid fracture versus isolated distal radial fractures was performed. Outcomes of function results, radiological evaluation, and patient reported scores were analyzed.

RESULTS

Ten studies including 1403 distal radius fractures were identified fitting inclusion criteria. There was no significant difference in wrist motion, grip strength, radial height, volar angle, ulnar variance, pain score, PRWE score, or SF-36 score for distal radial fractures associated with an ulnar styloid fracture versus isolated distal radial fractures. In final follow up, patients with associated an ulnar styloid fracture had lower radial inclination and higher DASH scores. But there was no significant clinical difference. In addition, we found there was no significant difference of outcomes between union and non-union ulnar styloid fractures.

CONCLUSIONS

Based on this meta-analysis, we suggest that an associated ulnar styloid fracture does not affect the outcomes of a distal radial fracture and clinicians should be caution in electing operative treatment for patients with an ulnar styloid fracture.

MR imaging of the traumatic triangular fibrocartilaginous complex tear

Triangular fibrocartilage complex is a major stabilizer of the distal radioulnar joint (DRUJ). However, triangular fibrocartilage complex (TFCC) tear is difficult to be diagnosed on MRI for its intrinsic small and thin structure with complex anatomy. The purpose of this article is to review the anatomy of TFCC, state of art MRI imaging technique, normal appearance and features of tear on MRI according to the Palmar's classification. Atypical tear and limitations of MRI in diagnosis of TFCC tear are also discussed.

Metaphyseal Versus Diaphyseal Ulnar Shortening Osteotomy for Treatment of Ulnar Impaction Syndrome: A Comparative Study

PURPOSE

To compare the clinical and radiographic outcomes and complication rates of diaphyseal and metaphyseal ulnar shortening osteotomies for the treatment of ulnar abutment syndrome.

METHODS

We performed a retrospective study comparing 35 patients who underwent either a metaphyseal (n = 14) or diaphyseal (n = 21) osteotomy. Radiographic and clinical outcomes were compared. Complication rates including infection, hardware removal, and reoperations were also assessed.

RESULTS

There were no differences in patient characteristics, ulnar variance, or pain and functional scores between groups. Metaphyseal osteotomy surgery time was shorter (45.5 vs 71.7 minutes) and resulted in greater ulnar shortening (4.8 vs 3.4 mm) compared with diaphyseal osteotomies. At an average 19.2-month follow-up, metaphyseal osteotomies were associated with greater improvement in pain and Quick-Disabilities of the Arm, Shoulder, and Hand questionnaire scores. The need for implant removal was the same in both groups. There were no complications in either group.

CONCLUSIONS

Results from this study suggest that metaphyseal osteotomies are a safe and effective alternative to diaphyseal osteotomies for the management of ulnar abutment syndrome. Although improved surgical time and postoperative outcomes are encouraging, further large-scale and properly powered studies with long-term outcomes will help characterize the benefit of one technique over another. Ultimately, the decision between a metaphyseal and diaphyseal osteotomy may be surgeon preference.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

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

The purpose of this prospective case series was to assess the efficacy of plate osteosynthesis using a low profile distal ulna plate for the management of persistently symptomatic non-unions of the base of the ulnar styloid. Six consecutive patients underwent resection of the non-union and plate osteosynthesis with a 2.0 mm distal ulna hook plate. Post-operative measurements of mean pain scores, QuickDASH scores, grip strength, and range of motion parameters showed significant improvements compared with the pre-operative values. No complications were reported at a mean follow-up of 25 months. The present study presents an alternative method for treating symptomatic ulnar styloid non-unions that provides stable fixation with low risk of implant removal.

LEVEL OF EVIDENCE

Therapeutic IV.

Differences in the Treatment of Distal Radius Fractures by Hand Fellowship Trained Surgeons: A Study of ABOS Candidate Data

PURPOSE

The management of distal radius fractures differs based on the nature of the fracture and the experience of the surgeon. We hypothesized that patients requiring surgical intervention would undergo different procedures when in the care of a surgeon with subspecialty training in hand surgery as compared with surgeons with no subspecialty training in hand surgery.

METHODS

We queried the ABOS database for case log information submitted for part II of the ABOS examination. Queries for all codes involved with distal radius fracture management were combined with associated codes for the management of median nerve neuropathy, triangular fibrocartilage complex tears, ulnar shaft, and styloid fractures. Hand fellowship trained orthopedic surgeons were compared with those completing other fellowships and non-fellowship trained orthopedic surgeons during their board collection period.

RESULTS

During the study period, 2,317 orthopedic surgeons reported treatment of 15,433 distal radius fractures. Of these surgeons, 411 had hand fellowship training. On a per surgeon basis, fellowship trained hand surgeons operatively treated more multifragment intra-articular distal radius fractures than their non-hand fellowship trained counterparts (5.3 vs 1.2). Additional procedures associated with the management of distal radius fractures were also associated with the fellowship training of the treating surgeon.

CONCLUSIONS

Among orthopedic surgeons taking part II of the ABOS certifying examination, differences exist in the type, management, and reporting of distal radius fractures among surgeons with different areas of fellowship training.

CLINICAL RELEVANCE

This study describes the association of hand surgery fellowship training on the choice of intervention for distal radius fractures and associated conditions.

Imaging of Sports-related Hand and Wrist Injuries: Sports Imaging Series

Hand and wrist injuries are common occurrences in amateur and professional sports and many of them are sport-specific. These can be divided into two categories: traumatic injuries and overuse injuries. The aim of this article is to review the most common hand and wrist sports-related lesions. Acute wrist injuries are predominantly bone fractures, such as those of the scaphoid, hamate hook, and ulnar styloid. Ligament lesions are more challenging for radiologists and may lead to carpal instability if undiagnosed. Overuse wrist injuries are mainly represented by tendinous disorders, with De Quervain syndrome and extensor carpi ulnaris tendon disorders being the most common among them; however, there are other possible disorders such as impaction syndromes, stress fractures, and neurovascular lesions. Finally, finger lesions, including closed-tendon injuries (mallet and boutonniere injuries, jersey finger, and boxer's knuckle), flexor pulley injuries, and skier's thumb, should also be detected. (©) RSNA, 2016 Online supplemental material is available for this article.

Clinical DRUJ instability does not influence the long-term functional outcome of conservatively treated distal radius fractures

OBJECTIVE

The presence of distal radioulnar joint (DRUJ) instability remains often unnoticed initially, but may worsen functional outcome of distal radius fractures (DRF). The aim of this study was to evaluate the influence of concurring clinical DRUJ instability on the outcome of conservatively treated DRF.

METHODS

In a retrospective cohort study, all unilateral, conservatively treated DRF patients were invited for physical examination, CT scan of both wrists and filling out questionnaires. Static and dynamic DRUJ instability were clinically tested.

RESULTS

Forty-nine DRF patients with a mean follow-up of 4.2 years (SD 0.5) were assessed. Seventeen patients tested positive for DRUJ instability. No differences were found in baseline characteristics between the DRUJ stable and unstable group. Apart from wrist flexion, no statistical significant differences in outcome was found between patients with and without DRUJ instability.

CONCLUSION

The presence of clinical DRUJ instability does not seem to affect functional outcome of conservatively treated distal radius fractures at long-term follow-up.

Slot-type fractures of the scapula at New Kingdom Tell El-Amarna, Egypt

Amarna is the archaeological representation of Akhetaten, the short-lived Egyptian capital city of Akhenaten (reign 1352-1336BCE).Five adult males excavated from the South Tombs Cemetery (STC) (total n>400) at Amarna exhibit slot-type fracture lesions of the scapula, and two of these lesions exhibit evidence of active bone remodeling at the time of death.The lesions in question are described and a full differential diagnosis is considered.The differential diagnosis rules out atrophic perforations, scapular foramina, tumors, and occupational and accidental trauma.Given the location, morphology, and surrounding bony changes, these lesions are consistent with sharp force trauma, specifically stabbing.These lesions most likely represent the consequence of corporal punishment in the form of "strokes" accompanied by "open wounds" known from Egyptian literature for punishment of a wide range of civil and criminal activities.Alternatively, several pigs at Amarna show similar wound morphologies of the cranium and scapulae, which have been interpreted by other authors to represent ritualized punishment of the god Seth, who is often represented as a pig.The lesions described here are consistent in morphology and positioning with the swine examples, and may represent further, cross-species, evidence of ritualized punishment at the ancient capital city.

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.

Imaging Findings of the Distal Radio-Ulnar Joint in Trauma

Traumatic lesions of the distal radio-ulnar joint (DRUJ) occur frequently in conjunction with fractures of the distal radius. They are a common cause of pain and limited range of motion after distal radial fractures. Due to the complex anatomy they are however often ignored or underappreciated. Distal radial fractures and luxations of the DRUJ often disturb the normal curvature of the radial notch and cause damage to the cartilage of this joint. The growth of the radius may be disrupted, resulting in a positive ulnar variance, and possibly give rise to complications such as ulnar abutment and motion restriction.

Ulnar styloid fractures – sometimes barely visible on plain film – may give rise to symptomatic bony pseudarthrosis, dislocation and laceration of the tendon of the m. extensor carpi ulnaris and a rare posttraumatic deformity of the ulnar epiphysis. Also the possibility of lesions at the adjacent triangular fibrocartilage complex and the joint capsule should be kept in mind.

This paper presents a pictorial review of the complex functional anatomy and pathologic conditions of this joint and emphasises why the DRUJ should be evaluated independently and thoroughly. The merit of each imaging modality is mentioned.

A correction article relating to Fig. 2 and Fig. 27 can be found here: http://dx.doi.org/10.5334/jbr-btr.966

Prophylactic corticosteroid injection in ulnar wrist pain in distal radius fracture

BACKGROUND

Ulnar sided wrist pain is one of the most common complications of distal radius fractures. The simplest method for decreasing pain for this affliction is corticosteroid injection. The present study was designed to assess the effect of corticosteroid injection in the prevention of ulnar sided wrist pain.

MATERIALS AND METHODS

In this clinical trial patients with distal radius fractures scheduled for closed reduction and percutaneous pin fixation were divided into control and corticosteroid groups. In the corticosteroid group, the patient received a single betamethasone injection in the dorsoulnar side of the wrist before reduction, while the control group received placebo. The patients were to be followed for at least 6 months.

RESULTS

82 patients were followed for 6 months. At the end of the 3 months followup the difference between the two groups about the number of individuals without ulnar sided wrist pain was statistically significant (P = 0.038), so that less patients in the control group were painless, while this was not the case in the 6 months followup (P = 0.507), but in the both time frames the mean grip power, visual analog pain score and the disabilities of the arm, shoulder and hand (DASH) score showed statistically significant difference between the two groups, so that the corticosteroid groups demonstrated greater power grip and less scores in pain and DASH (P < 0.05).

CONCLUSION

Based on the findings of the present study it seems that prophylactic corticosteroid injection will be associated with a decrease in the severity of wrist pain in patients with acute distal radius fractures. With regard to the decrease in the number of painless individuals, it seems that the decrease is not persistent. Overall the need for a study with longer followup is obvious.

Ulnar styloid process nonunion and outcome in patients with a distal radius fracture: a meta-analysis of comparative clinical trials

PURPOSE

There is no consensus on the relation between ulnar styloid process nonunion and outcome in patients with distal radius fractures. The aim of this study was to analyze whether patient-reported outcome is influenced by the nonunion of the accompanying ulnar styloid fracture in distal radius fracture patients.

METHODS

A meta-analysis of published studies comparing outcomes after distal radius fractures with a united versus a non-united ulnar styloid process was performed. In addition, if provided by the authors, the raw data of these studies were pooled and analysed as one study. The outcome measures of the analyses included patient-reported outcome, functional outcome, grip-strength, pain, and distal radioulnar joint (DRUJ) instability.

RESULTS

Data from six comparative studies were included, concerning 365 patients with a distal radius fracture. One hundred and thirty-five patients with an ulnar styloid union were compared with 230 patients with a nonunion of the ulnar styloid. No significant differences were found between groups regarding any outcome measure.

CONCLUSION

Based on this meta-analysis, there is no relation between the nonunion of the ulnar styloid process and function in patients with a distal radius fracture.

The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna

OBJECTIVE

The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities.

CONCLUSION

The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.

Defining residual radial translation of distal radius fractures: a potential cause of distal radioulnar joint instability

BACKGROUND

Instability of the distal radioulnar joint (DRUJ) is a complication that can occur following distal radius fracture or malunion. We have observed that residual radial translation of the distal radius, relative to the radial shaft, may be a causal factor of DRUJ instability, even once the traditional radiographic parameters (volar tilt, radial inclination, and ulnar variance) have been restored. Residual radial translation of the distal fragment may cause detensioning of the distal interosseous membrane (IOM) and pronator quadratus with poor apposition between the ulnar head and sigmoid notch. This may potentially lead to persistent instability of the ulnar head following internal fixation. Residual radial translation deformity is at risk of being overlooked by the wrist surgeon as there is no existing radiographic parameter that accurately measures this deformity.

PATIENTS AND METHODS

In this study, 100 normal wrist radiographs were reviewed by three fellowship-trained orthopedic surgeons to develop a simple and reproducible technique to measure radial translation.

RESULTS

Utilizing the method described, the point of intersection between the ulnar cortex of the shaft of the radius and the lunate left a mean average of 45.48% (range 25–73.68%) of the lunate remaining on the radial side. In the majority of cases more of the lunate resided ulnar to this line. High levels of agreement with inter-rater (intraclass coefficients = 0.967) and intra-rater (intraclass coefficients = 0.79) reliability was observed.

CONCLUSIONS

The results of this study can be used to define a normal standard against which residual radial translation can be measured to assess the reduction of distal radius fractures. This new parameter aids in the development of surgical techniques to correct residual radial translation deformity. In addition, awareness and correction of this potential malreduction at the time of surgery may decrease the need for other procedures on the ulnar side of the wrist to improve DRUJ stability, such as ulnar styloid fixation, TFCC repair, or ligamentous grafting [corrected].

Transstyloid perilunate fracture-dislocations of the carpus, a review of two cases

Transstyloid perilunate fracture-dislocations of the carpus resulting from a force in an ulnar-to-radial direction are rare injuries. We present two cases of transstyloid perilunate fracture-dislocations of the carpus, one of which dislocated palmarly and was accompanied with fractures of the triquetrum and the ulnar styloid. The treatment algorisms are described and a satisfactory reduction is the goal for optimal functional recovery.

The incidence of ulnocarpal complaints after distal radial fracture in relation to the fracture of the ulnar styloid

Two hundred distal radial fractures, with a mean follow up of 20 months (range 6-49), were divided into three groups according to the presence and healing status of an ulnar styloid fracture. The patients underwent both clinical and radiological examination and completed two different questionnaires. One hundred and one, of 200 distal radial fractures, were associated with an ulnar styloid fracture. Forty-six of these developed an ulnar styloid nonunion. The authors encountered significantly higher pain scores (ulnar sided pain p = 0.012), a higher rate of DRUJ instability (p = 0.032), a greater loss of motion and grip strength (p = 0.001), and a poorer clinical outcome in cases with an ulnar styloid fracture, but no differences were apparent when those with healed ulnar styloid fractures or ulnar styloid nonunions were compared (p > 0.05). The investigators propose that the incidence of ulnocarpal complaints following distal radial fracture depends on the presence but not the healing status of an ulnar styloid fracture.

The effects of dorsally angulated distal radius fractures on distal radioulnar joint stability: a biomechanical study

Relationship between dorsal tilt of the distal radius and distal radioulnar joint stability was examined. Stiffness in dorsopalmar displacement of the radius (distal radioulnar joint stiffness) was recorded at 10° intervals until 30° of dorsal angulation from 10° of palmar tilt. Tests were repeated after partial sectioning of the radioulnar ligament, then after complete sectioning of the radioulnar ligament. All data were compared with control (intact triangular fibrocartilage complex, 10° of palmar tilt). The distal radioulnar joint stiffness in dorsal translation decreased significantly with dorsal tilt 10° and 20° in pronation. Partial sectioning of the radioulnar ligament indicated a decrease of the distal radioulnar joint stiffness in the dorsal translation at neutral tilt to 20° of dorsal tilt in the neutral position and in pronation. Distal radioulnar joint stiffness decreased significantly in both dorsal and palmar translations in all forearm positions at 10° and 20° of dorsal tilt. From these findings, the dorsal angulation of the radius should be corrected to less than 10° of dorsal tilt.

T.A.C.' pin fixation for basal ulnar styloid fractures associated with distal radius fractures

Distal radius fractures often accompany ulnar styloid fractures. As basal ulnar styloid fractures sometimes result in symptomatic nonunion causing distal radioulnar joint instability, surgical intervention should be considered as a method of treatment. However, conventional methods of internal fixation for ulnar styloid involving tension band wiring and pinning often causes irritation of hardware, and required further surgery. We performed T.A.C.' pin fixation for basal ulnar styloid fractures associated with distal radius fractures in 24 patients. X-rays showed union at an average of 6.8 weeks postoperatively in all but 1 case, which resulted in asymptomatic fibrous nonunion. Irritation from the hardware was recognized in 3 cases, but soon disappeared after recutting or removal of the pin. At the final follow-up, no symptoms involving ulnar wrist pain or distal radioulnar instability were noted. T.A.C.' pin fixation for basal ulnar styloid is a useful method and rarely requires further surgery compared with conventional methods.