Distal radioulnar instability is an independent worsening factor in distal radial fractures

Optimal Positioning for Volar Plate Fixation of a Distal Radius Fracture: Determining the Distal Dorsal Cortical Distance

Distal radius fractures are currently among the most common fractures of the musculoskeletal system. With a population that is living longer, being more active, and the increasing incidence of osteoporosis, these injuries will continue to become increasingly prevalent. When operative fixation is indicated, the volar locking plate has recently become the treatment of choice. However, despite its success, suboptimal position of the volar locking plate can still result in radiographic loss of reduction. The distal dorsal cortical distance is being introduced as an intraoperative radiographic tool to help optimize plate position and minimize late loss of fracture reduction.

Computed tomography for the detection of distal radioulnar joint instability: normal variation and reliability of four CT scoring systems in 46 patients

OBJECTIVES

The diagnosis of distal radioulnar joint (DRUJ) instability is clinically challenging. Computed tomography (CT) may aid in the diagnosis, but the reliability and normal variation for DRUJ translation on CT have not been established in detail. The aim of this study was to evaluate inter- and intraobserver agreement and normal ranges of CT scoring methods for determination of DRUJ translation in both posttraumatic and uninjured wrists.

MATERIALS AND METHODS

Patients with a conservatively treated, unilateral distal radius fracture were included. CT scans of both wrists were evaluated independently, by two readers using the radioulnar line method, subluxation ratio method, epicenter method and radioulnar ratio method. The inter- and intraobserver agreement was assessed and normal values were determined based on the uninjured wrists.

RESULTS

Ninety-two wrist CTs (mean age: 56.5 years, SD: 17.0, mean follow-up 4.2 years, SD: 0.5) were evaluated. Interobserver agreement was best for the epicenter method [ICC = 0.73, 95 % confidence interval (CI) 0.65-0.79]. Intraobserver agreement was almost perfect for the radioulnar line method (ICC = 0.82, 95 % CI 0.77-0.87). Each method showed a wide normal range for normal DRUJ translation. Normal range for the epicenter method is -0.35 to -0.06 in pronation and -0.11 to 0.19 in supination.

CONCLUSION

DRUJ translation on CT in pro- and supination can be reliably evaluated in both normal and posttraumatic wrists, however with large normal variation. The epicenter method seems the most reliable. Scanning of both wrists might be helpful to prevent the radiological overdiagnosis of instability.

Effect of volar angulation of extra-articular distal radius fractures on distal radioulnar joint stability: a biomechanical study

The relationship between increased volar tilt of the distal radius and distal radioulnar joint stability was examined. Distal radioulnar joint stiffness was recorded at 10° intervals from 10° dorsal angulation to 20° of volar angulation from the anatomical position of the radius. Tests were performed with the intact radioulnar ligament and repeated after partial and then complete sectioning of the radioulnar ligament at the ulnar fovea. With the intact radioulnar ligament, distal radioulnar joint stiffness increased significantly at 10° and 20° of volar angulation. Partial sectioning of the radioulnar ligament resulted in an approximate 10% decrease of distal radioulnar joint stiffness compared with the intact state, but distal radioulnar joint stiffness still increased significantly with greater volar tilt. Complete sectioning of the radioulnar ligament significantly decreased distal radioulnar joint stiffness, and increasing the volar tilt did not result in increased distal radioulnar joint stiffness. These results suggest that volar angulation deformities of the distal radius should be corrected to 10° of volar tilt when the triangular fibrocartilage complex is intact. Level of evidence: N/A.

Surgical treatment of acute distal radioulnar joint instability associated with distal radius fractures

This study investigates the question of whether open repair of acute distal radioulnar joint instability at the time of volar plating of distal radius fractures would enable early mobilization of the wrist without the risk of distal radioulnar joint instability. We evaluated 29 patients of mean age 53 years with a distal radius fracture and acute distal radioulnar joint instability who underwent volar plating of the radius combined with surgical repair of the triangular fibrocartilage complex or an ulnar styloid base fracture, followed by active motion exercise of the wrist at 1 week after surgery. At 1 year after treatment, all patients had a stable distal radioulnar joint and grip strength averaged 90% of the normal side. This study demonstrates that surgical repair of the triangular fibrocartilage complex or ulnar styloid fracture followed by early mobilization did not result in distal radioulnar joint instability, and suggests that the surgical treatment of distal radioulnar joint instability may permit early mobilization of the wrist in patients who are considered suitable for rapid rehabilitation after surgery. Type of study: Therapeutic Level IV.

[Carpal lesions associated with dislocated fractures of the distal radius. A systematic screening of 104 fractures using preoperative CT and MRI]

BACKGROUND

The functional outcome of surgically treated dislocated fractures of the distal radius is limited and does not correlate with radiographic results. Additional carpal lesions are assumed to be the cause. This study has evaluated which carpal lesions are associated with dislocated fractures of the distal radius.

MATERIAL AND METHODS

A total of 104 consecutive patients with dislocated fractures of the distal radius were included in the study. The injured wrist was examined by radiography, computed tomography (CT) and magnetic resonance imaging (MRI) to determine additional carpal lesions.

RESULTS

Radiographically 51 of the 104 fractures presented as type A according to the AO classification, 10 as type B and 39 as type C. The CT scan detected that only 5 of the 51 type A fractures were exclusively metaphyseal fractures. All type A fractures were associated with ligamental lesions in MRI.

CONCLUSIONS

The results of the study confirm the hypothesis that every dislocated fracture of the distal radius is a combined carpal trauma associated with additional osseous and/or ligamental lesions.

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.

Distal radio-ulnar joint instability in children and adolescents after wrist trauma

This study retrospectively evaluated the medical records and radiographs of patients younger than aged 25 that were referred for a second opinion due to ulnar-sided wrist pain and persistent distal radio-ulnar (DRU) joint instability. We identified 85 patients with a major wrist trauma before the age of 18. Median age at trauma was 14 years. Median time between trauma and diagnosis of DRUJ instability was 3 years. Sixty-seven patients (79%) had sustained a fracture at the initial trauma. The two most common skeletal injuries related to the DRUJ instability were Salter-Harris type II fractures (24%) and distal radius fractures (19%). In 19 patients (22%), the secondary DRUJ instability was caused by malunion or growth arrest. Eighteen patients (21%) had no fracture; in spite of this, they presented with subsequent symptomatic DRUJ instability. Fourteen of these 18 patients had a triangular fibrocartilage complex (TFCC) tear, confirmed by arthroscopy, open surgery, or magnetic resonance imaging. In conclusion, late DRUJ instability due to wrist fractures or isolated TFCC tears was found to be common in children and adolescents.

LEVEL OF EVIDENCE

IV.

Distal radioulnar joint kinematics in simulated dorsally angulated distal radius fractures

PURPOSE

To examine the effects of dorsal angulation deformities of the distal radius with and without triangular fibrocartilage complex (TFCC) rupture on the 3-dimensional kinematics of the distal radioulnar joint (DRUJ) during simulated active motion.

METHODS

Nine fresh-frozen cadaveric specimens were tested in a forearm simulator that produced active forearm rotation. Dorsal angulation deformities of the distal radius with 10°, 20°, and 30° angulation were created. Changes in the position of the ulna relative to the radius at the DRUJ as a consequence of each dorsal angulation deformity were quantified during simulated active supination in terms of volar, ulnar, and distal displacement of the ulna. Testing was performed initially with the TFCC intact and repeated after complete sectioning of the TFCC at its ulnar insertion.

RESULTS

Increasing dorsal angulation deformities of the distal radius significantly increased volar, ulnar, and distal displacement of the ulna when the TFCC was intact. Sectioning of the TFCC significantly increased volar displacement of the ulna in dorsal angulation deformities. As little as 10° of dorsal angulation significantly increased distal displacement of the ulna with the TFCC intact and resulted in a significant increase in volar, ulnar, and distal displacement of the ulna with sectioned TFCC.

CONCLUSIONS

Dorsal angulation deformities of the distal radius affect the 3-dimensional kinematics of the DRUJ, especially with the TFCC sectioned.

CLINICAL RELEVANCE

The progressive change in DRUJ kinematics with increasing dorsal angulation may partially explain the relationship between the magnitude of dorsal angulation of distal radius fractures and functional outcomes in younger patients. The status of the TFCC should be evaluated carefully, as well as the magnitude of osseous deformity in patients with distal radius fractures and malunions, because changes in DRUJ kinematics caused by dorsal angulation are greater when the TFCC is ruptured.

Radiographic and Arthroscopic Assessment of DRUJ Instability Due to Foveal Avulsion of the Radioulnar Ligament in Distal Radius Fractures

Background As the triangular fibrocartilage complex (TFCC) anchors the distal radius to the ulna via the radioulnar ligament (RUL), a severely displaced distal fragment of the radius may be associated with a foveal avulsion of the TFCC. The purpose of this retrospective study was to assess, radiographically and arthroscopically, the relationship between displacement of the radius, the ulnar styloid, and avulsion of the RUL resulting in distal radioulnar joint (DRUJ) instability. Materials and Methods Twenty-nine wrists of 29 patients with intra- and extra-articular distal radius fractures/malunion who underwent reduction or a corrective osteotomy of the displaced/malunited fracture, and/or wrist arthroscopy, were assessed radiographically and arthroscopically. Radial translation, radial inclination, radial shortening, volar or dorsal tilt, and the presence of an ulnar styloid fracture with more than 4 mm of displacement were measured from the initial films. Radiocarpal arthroscopy was used to assess peripheral lesions of the TFCC, while DRUJ arthroscopy was used to assess the foveal attachment. The relationship between displacement of the distal radius or the ulnar styloid fracture and the TFCC injury, including avulsion of the RUL, was recorded. Results Univariate analysis revealed that increased radial translation, decreased radial inclination, increased radial shortening, and an ulnar styloid fragment radially displaced by more than 4 mm were significant predictors of RUL avulsion at the fovea. Volar or dorsal tilt of the radius and ulnar variance did not correlate with RUL avulsion or TFCC injuries. Multiple logistic regression analysis revealed that radial translation was an independent risk factor of foveal avulsion of the RUL. Conclusions Increased radial translation and radial shortening and decreased radial inclination of the distal fragment can be associated with a foveal avulsion of the RUL. Radial translation can be an independent risk factor of foveal avulsion of the RUL.

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.

In-vivo measurement of distal radio-ulnar joint translation

Distal radio-ulnar joint (DRUJ) instability is increasingly recognised and assessment can be subjective and difficult. Previous research has used cadaveric models or in-vivo with CT, with variable results. A test device was designed to establish normal values of in-vivo DRUJ dorso-palmar translation. Twenty volunteers were recruited. Those with previous wrist/forearm injuries were excluded. The device held the elbow at 90° flexion and neutral forearm rotation, with the distal ulna secured. A dorso-palmar shear force was applied to the distal radius and displacement measured three times on each wrist alternately by the same operator. The mean translation of the DRUJ is 5.5 mm. Same-sided mean measurements for two subjects taken days apart varied by 1 mm. The intra-class correlation coefficient was 0.93. The device is reliable, reproducible and appears to be a simple valid test. Contralateral sides were comparable. It will primarily be a research device to guide clinical practice in DRUJ instability.

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

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

Early prognostic factors in distal radius fractures in a younger than osteoporotic age group: a multivariate analysis of trauma radiographs

Background

Treatment of distal radius fractures in patients of a younger than osteoporotic age is complex, because they often are the result of a high-energy trauma and have intra-articular fractures and associated injuries. As yet no fracture classification exists that predicts outcome. Our aim was to find the earliest possible prognostic factor by testing which radiological parameter on the trauma radiograph would have the greatest impact on clinical outcome in a younger than osteoporotic age group.

Methods

We assessed 66 patients (34 F) with unilateral fractures of the distal radius from a non-Osteoporotic age group. The median age was 42 years, (10^th -90^th percentile 20–54). Pre-reduction antero-posterior and lateral wrist radiographs were obtained and fracture pattern, radiocarpal joint surface tilt, radial length, radial inclination and ulnar variance were measured. Clinical outcome was assessed with the subjective part as well as the complete modified Gartland and Werley score. Multivariate analysis of those parameters was performed to assess which radiological parameter would best predict outcome.

Results

It was found that post-traumatic ulna + (>2 mm) was the single factor that significantly correlated with a bad outcome. An intra-articular fracture pattern may also be a strong marker; however this was not statistically significant (RR 95% conf interval 0.94 – 20.59).

Conclusions

The present study showed that post-traumatic ulna + is the most important factor in predicting bad outcome in non-osteoporotic patients, but that especially intra-articular fractures and to a lesser extent dorsal tilt may be of importance too.

Dorsal scapholunate ligament injury: a classification of clinical forms

The dorsal scapholunate (SL) ligament may disrupt in variety of ways. Each form of injury requires specific fixation. To investigate the incidence of each type of ligament failure, the records of 45 patients with adequate information, good quality pictures, or videos demonstrating injury characteristics were reviewed. Four types of SL injury were found: type 1 (lateral avulsion from the scaphoid) was the most frequent, present in 19 patients (42%); type 2 (medial avulsion from the lunate) was the least frequent, with 7 cases (16%); type 3 (mid-substance rupture) was found on 9 occasions (20%); and type 4 (partial rupture plus elongation) was observed on 10 occasions (22%). Based on our observations, we submit that an arthroscopically assisted SL capsuloplasty may not be possible in all cases, particularly not when the ligament has avulsed off the bone (60% of the cases), leaving no ligament remnant on one side. Most patients will require ligament reattachment techniques using transosseous sutures, bone anchors, or ligament reconstruction.

Radiographic outcomes of volar locked plating for distal radius fractures

PURPOSE

To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures.

METHODS

We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type.

RESULTS

At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome.

CONCLUSIONS

Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Clinical and radiographic factors associated with distal radioulnar joint instability in distal radius fractures

BACKGROUND

Distal radioulnar joint (DRUJ) instability is an important cause of ulnar-sided wrist pain in distal radius fractures. However, instability is frequently undiagnosed and the clinical and radiographic factors associated with instability are not well understood.

QUESTIONS/PURPOSES

We therefore identified clinical and radiographic factors associated with DRUJ instability in distal radius fractures.

PATIENTS AND METHODS

We retrospectively reviewed all 221 patients who underwent surgical treatment for unstable distal radius fractures from 2007 to 2010. Ten patients (five men and five women) had DRUJ instability by intraoperative manual testing (Group I); these patients had a median age of 52 years. The other 211 patients (81 men and 130 women) (Group II) had a median age of 55 years. Clinical and radiographic data were compared between the groups.

RESULTS

The incidence of open wounds at the wrist and the relative ulnar length measured on the prereduction radiograph were greater in Group I. An open wound at the wrist and positive ulnar variance of 6 mm or greater on the prereduction radiograph increased the risk of DRUJ instability (relative risks = 45 and 17, respectively) in distal radius fractures.

CONCLUSIONS

An open wound at the wrist or positive ulnar variance of 6 mm or greater observed on the prereduction radiograph in patients with distal radius fractures should alert the physician to the possibility of DRUJ instability.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Subluxation-related ulnar neuropathy (SUN) syndrome related to distal radioulnar joint instability

Ulnar neuropathy coexistent with distal radioulnar joint (DRUJ) instability has previously been observed in our practice. The aim of this study was to define this phenomenon and investigate the hypothesis that the cause of this intermittent, positional ulnar neuropathy is related to kinking of the ulnar nerve about the DRUJ. Ulna neuropathy was present in 10/51 (19.6%) of a historical cohort of patients who presented with DRUJ instability. Nine subsequent patients with DRUJ instability and coexistent ulnar neuropathy underwent 3-T magnetic resonance imaging to better understand the mechanism of the observed syndrome. Both 3D qualitative and quantitative analyses were used to assess the presence of nerve 'kinking', displacing the nerve from its normal course and causing nerve compression/distraction in the distal forearm and Guyon's canal. Results of the quantitative analysis were statistically significant (p < 0.05). The clinical features of the condition have been delineated and termed subluxation-related ulnar neuropathy or SUN syndrome. The imaging study was a level II diagnostic study.

The natural course of traumatic triangular fibrocartilage complex tears in distal radial fractures: a 13-15 year follow-up of arthroscopically diagnosed but untreated injuries

PURPOSE

To evaluate the long-term results of a prospective, longitudinal case series of untreated, traumatic triangular fibrocartilage complex (TFCC) tears found in displaced distal radial fractures.

METHODS

Between 1995 and 1997, 51 patients (24 men, 27 women; age, 20-57 y) with a displaced distal radius fracture had wrist arthroscopy to identify associated injuries. Forty-three patients had complete or partial tears of the TFCC, which were not treated. All patients were contacted in 2010, 13-15 years after the injury. One patient had had a TFCC reattachment due to painful distal radioulnar joint instability and was excluded. Thirty-eight patients returned for a radiographic and clinical follow-up that recorded strength, distal radioulnar joint laxity, range of motion, pain scale score, and subjective and objective outcome scores.

RESULTS

After 13-15 years, 17/38 patients were lax in the distal radioulnar joint. The mean grip strength was worse in the patients with a lax distal radioulnar joint (83%, SD 15 of the contralateral side vs 103%, SD 33). The median Gartland and Werley score was 5 (good; range, 0-15) in the lax group compared to 1 (excellent; range, 0-9) in the non-lax group, and the median Disabilities of the Arm, Shoulder, and Hand scores were 14 (range, 0-59) and 5 (range, 0-70) respectively.

CONCLUSIONS

In this 13-15 year, prospective, longitudinal outcome study of the natural course of TFCC tears associated with distal radius fracture, only 1 patient had been operated on for painful instability since the injury. The subjective and objective results did not provide evidence that a TFCC injury would influence the long-term outcome. However, trends were found and, by speculation, the low number of patients in the series and the risk for a type II error could be the cause of absent statistically significance. Larger, preferably prospective, randomized studies are needed to find out whether a more aggressive treatment is beneficial.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic I.

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

PURPOSE

The aim of the study was to examine triangular fibrocartilage (TFCC) injury patterns associated with unstable, extra-articular dorsally displaced distal radius fractures.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Clinical and non-clinical aspects of distal radioulnar joint instability

Untreated distal radioulnar joint (DRUJ) injuries can give rise to long lasting complaints. Although common, diagnosis and treatment of DRUJ injuries remains a challenge. The articulating anatomy of the distal radius and ulna, among others, enables an extensive range of forearm pronosupination movements. Stabilization of this joint is provided by both intrinsic and extrinsic stabilizers and the joint capsule. These structures transmit the load and prevent the DRUJ from luxation during movement. Several clinical tests have been suggested to determine static or dynamic DRUJ stability, but their predictive value is unclear. Radiologic evaluation of DRUJ instability begins with conventional radiographs in anterioposterior and true lateral view. If not conclusive, CT-scan seems to be the best additional modality to evaluate the osseous structures. MRI has proven to be more sensitive and specific for TFCC tears, potentially causing DRUJ instability. DRUJ instability may remain asymptomatic. Symptomatic DRUJ injuries treatment can be conservative or operative. Operative treatment should consist of restoration of osseous and ligamenteous anatomy. If not successful, salvage procedures can be performed to regain stability.

Management of soft-tissue injuries in distal radius fractures

Distal radius fractures account for approximately 15% of all fractures in adults, and are the most common fractures seen in the emergency department. Soft-tissue injuries associated with distal radius fractures may influence strategies for the acute management of the fracture, but also may be a source of persisting pain and/or disability despite fracture healing. This article describes soft-tissue injuries and considerations for treatment associated with distal radius fractures, including injuries to the skin, tendon and muscle, ligaments, the triangular fibrocartilage complex, neurovascular structures, and related conditions such as compartment syndrome and complex regional pain syndrome.

[Unrepaired fracture of the styloid process of the ulna: not a bad treatment result at distal radius fracture]

BACKGROUND

There are well-defined criteria for the treatment of distal radius fractures but the impact of an unrepaired fracture of the styloid process of the ulnar on recovery after operative treatment is uncertain. This study evaluated radiological and functional results after different operative treatment procedures of distal radius fractures in patients with an untreated fracture of the styloid process of the ulna and those without such a fracture.

METHODS

Out of 480 patients with operatively treated distal radius fractures 238 were examined at least 1 year after injury. The fracture of the styloid process of the ulna was not repaired. Three groups (patients without a fracture of the styloid process of the ulna, patients with a tip fracture and those with a basal fracture) were evaluated by multivariate analysis (MANOVA) in order to detect influences of the fracture of the styloid process of the ulna on the radiological and functional results.

RESULTS

Neither the existence nor the location of the fracture of the styloid process of the ulna had a significant effect on the radiological and functional results (p(function)=0,849, p(radiology)=0,330, p(scores)=0,426, MANOVA).

CONCLUSIONS

The repair of a fracture of the styloid process of the ulna is not necessary if reduction and fixation of the distal radius fracture is anatomical and stable.

The biomechanical effect of the distal interosseous membrane on distal radioulnar joint stability: a preliminary anatomic study

PURPOSE

The distal interosseous membrane (DIOM) is a secondary stabilizer of the distal radioulnar joint (DRUJ) and has a considerably variable morphology. The purpose of this study was to investigate whether innate DRUJ stability is influenced by the anatomic variation of the DIOM.

METHODS

Ten fresh-frozen cadaver upper extremities were used in this study. The humerus and the ulna were affixed rigidly to a custom-made apparatus, with the elbow in 90° of flexion. Testing was performed by translating the radius in volar and dorsal directions relative to the ulna, with a 20-N applied force in neutral forearm alignment, 60° pronation, and 60° supination. Total translation of the radius was measured as DRUJ laxity. After the experiment, we investigated anatomic variation of the DIOM, especially regarding the existence of the distal oblique bundle (DOB), which is a notably thick fiber within the DIOM. We compared the DRUJ stability between the groups with and without the DOB.

RESULTS

The DOB was found in 4 of 10 specimens. The group with a DOB demonstrated a significantly greater DRUJ stability in the neutral position than the group without a DOB. In pronated and supinated forearm positions, no significant difference in DRUJ stability was obtained between the groups with and without a DOB.

CONCLUSIONS

Innate DRUJ stability in the neutral forearm position was greater in the group with a DOB than in those without a DOB.

CLINICAL RELEVANCE

This study suggests that considerable variation exists in DRUJ laxity and that it partially depends on anatomical variations of the DIOM.

Radioulnar laxity and clinical outcome do not correlate after a distal radius fracture

Injury to the triangular fibrocartilage complex associated with distal radius fracture may cause symptoms of ulnar instability. Assessed by a radioulnar stress test, increased laxity of the distal radioulnar joint has in two previous studies been depicted to be associated with poorer outcome. This prospective study of 40 adults investigates the correlation of this test with functional outcome as measured by DASH. No clinically significant difference was found in relation to this test at two and five years after injury. Therefore using this test alone to decide whether or not to perform an acute repair of the TFCC cannot be recommended.

Pathomechanisms of ulnar ligament lesions of the wrist in a cadaveric distal radius fracture model

BACKGROUND AND PURPOSE

Mechanisms of injury to ulnar-sided ligaments (stabilizing the distal radioulnar joint and the ulna to the carpus) associated with dorsally displaced distal radius fractures are poorly described. We investigated the injury patterns in a human cadaver fracture model.

METHODS

Fresh frozen human cadaver arms were used. A dorsal open-wedge osteotomy was performed in the distal radius. In 8 specimens, pressure was applied to the palm with the wrist in dorsiflexion and ulnar-sided stabilizing structures subsequently severed. Dorsal angulation was measured on digitized radiographs. In 8 other specimens, the triangular fibrocartilage complex (TFCC) was forced into rupture by axially loading the forearm with the wrist in dorsiflexion. The ulnar side was dissected and injuries were recorded.

RESULTS

Intact ulnar soft tissues limited the dorsal angulation of the distal radius fragment to a median of 32(o) (16-34). A combination of bending and shearing of the distal radius fragment was needed to create TFCC injuries. Both palmar and dorsal injuries were observed simultaneously in 6 of 8 specimens.

INTERPRETATION

A TFCC injury can be expected when dorsal angulation of a distal radius fracture exceeds 32(o). The extensor carpi ulnaris subsheath may be a functionally integral part of the TFCC. Both dorsal and palmar structures can tear simultaneously. These findings may have implications for reconstruction of ulnar sided soft tissue injuries.

The use of kinematic and parametric information to highlight lack of movement and compensation in the upper extremities during activities of daily living

A problem that is common to the study of upper limb kinematics and gait analysis is the translation of the evidence from kinematic measurements into easily interpretable information on the status of the patient, such as the amount of compensation or lack of motion. In this study parameters that can be helpful in the rapid and clear identification of limited wrist motion and compensation were derived from kinematic data. A group of six subjects (group A) with no hand impairment, average age 32.5 ys SD 10.7 ys, and another group of five subjects (group B), average age 34.2 ys SD 16.8 ys, having suffered from distal radius fracture were tested during a cyclic activity of daily living. The activity simulated page turning. Thorax, shoulder, elbow and wrist angles were measured during this task using a motion capture system. Corresponding angle ranges were also calculated. The active range of motion (AROM) found for Group B was generally lower than that of Group A, particularly for elbow supination and wrist movements, with wrist flexion/extension statistically smaller for group B (P=0.02). Additional parameters that took into account lack of movements at the wrist and compensation from shoulder elevation, rotation and elbow pronation/supination proved to be more useful at identifying those subjects of group B outside the normative range and can provide clinicians with a rapid and efficient tool that can shorten the analysis process and help make more informed decisions on therapeutic treatments.

Treatment of distal radius fractures

The clinical practice guideline is based on a systematic review of published studies on the treatment of distal radius fractures in adults. None of the 29 recommendations made by the work group was graded as strong; most are graded as inconclusive or consensus; seven are graded as weak. The remaining five moderate-strength recommendations include surgical fixation, rather than cast fixation, for fractures with postreduction radial shortening >3 mm, dorsal tilt >10 degrees , or intra-articular displacement or step-off >2 mm; use of rigid immobilization rather than removable splints for nonsurgical treatment; making a postreduction true lateral radiograph of the carpus to assess dorsal radial ulnar joint alignment; beginning early wrist motion following stable fixation; and recommending adjuvant treatment with vitamin C to prevent disproportionate pain.

Clinical impact of United versus nonunited fractures of the proximal half of the ulnar styloid following volar plate fixation of the distal radius

PURPOSE

Distal radius fractures are often associated with a fracture of the ulnar styloid at its base. This study tested the null hypothesis that there is no difference in outcome between patients with union and nonunion of a fracture of the proximal half of the ulnar styloid 6 months after volar plate fixation of a fracture of the distal radius.

METHODS

A total of 36 consecutive patients with fractures of both distal radius and the proximal half of the ulnar styloid enrolled in 1 of 2 clinical trials evaluating volar plate fixation of the distal radius had no treatment of the ulnar styloid fracture. Six months after surgery, wrist function was assessed using the Mayo wrist score and the Gartland and Werley score system, and arm-specific health status was measured using the Disabilities of the Arm, Shoulder, and Hand questionnaire. Pain was assessed on a 10-point ordinal scale. Nonunion of the fracture of the proximal half of the ulnar styloid was defined as no signs of consolidation on 6-month postoperative radiographs. At the 6-month follow-up, patients were assessed for overall wrist function but not specifically for ulnar-sided wrist problems or stability.

RESULTS

Sixteen ulnar styloid fractures had united, and 20 had not. There were no differences in demographic and injury characteristics. There were no significant differences in motion; strength; Gartland and Werley scores; Mayo scores; Disabilities of the Arm, Shoulder, and Hand scores; or pain scores 6 months after fracture.

CONCLUSIONS

Nonunion of a fracture of the proximal half of the ulnar styloid has no effect on wrist function, pain, and upper extremity-specific health status 6 months after volar plate fixation of a fracture of the distal radius.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Should an ulnar styloid fracture be fixed following volar plate fixation of a distal radial fracture?

BACKGROUND

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.

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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.

The effect of ulnar styloid fractures on patient-rated outcomes after volar locking plating of distal radius fractures

PURPOSE

Ulnar styloid fractures commonly occur with distal radius fractures (DRFs). Ulnar styloid fractures that involve the insertion of the radioulnar ligaments can cause distal radioulnar joint (DRUJ) instability, and the literature suggests that these fractures should be treated with open reduction internal fixation (ORIF). However, in the absence of DRUJ instability, the effects of ulnar styloid fractures are unknown. The purpose of this study is to evaluate the outcome of ulnar styloid fractures without DRUJ instability on patient-rated outcomes after DRF ORIF.

METHODS

Between 2003 and 2008, a cohort of DRF patients treated with volar plating was enrolled. Patients with DRUJ instability treated at the time of distal radius ORIF were excluded. Radiographs were evaluated to identify and characterize ulnar styloid fractures. Patient-rated outcomes were measured at 6 weeks, 3 months, 6 months, and 12 months postoperatively using the Michigan Hand Outcomes Questionnaire (MHQ). Regression analysis was performed to determine whether the presence of an ulnar styloid fracture, the size or displacement of the fracture, or the healing status of the fracture was predictive of MHQ scores.

RESULTS

One-hundred and forty-four patients were enrolled; 88 patients had ulnar styloid fractures. During the collection period, DRUJ instability was found intraoperatively in 3 patients; these patients had ulnar styloid ORIF and were not enrolled. The 144 patients with a stable DRUJ after DRF ORIF maintained DRUJ stability after surgery. In these patients, the presence of an ulnar styloid fracture did not affect MHQ scores. Furthermore, the size of the ulnar styloid fracture, the degree of displacement, and the healing status of the ulnar styloid did not affect MHQ scores.

CONCLUSIONS

In patients with a stable DRUJ after DRF ORIF ulnar styloid fractures did not affect subjective outcomes as measured by the MHQ.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.

The Buttazzoni classification of distal radial fractures in adults: interobserver and intraobserver reliability

Despite the fact that distal radial fracture is the commonest fracture, there is a little evidence-based knowledge about the value of its classification to guide management and predict prognosis. The available classification systems are either complicated or weakly applicable in clinical practice. Older's classification is the most reliable, but does not cover all radial fracture types. We evaluated the interobserver and intraobserver reliability of a new classification system which is a modification of Older's classification covering all radial fracture types. Two hundred and thirty-two consecutive adult patients with acute distal radial fractures were blindly evaluated according to the new classification by three orthopedic surgeons twice with 1-year interval. The interobserver reliability was measured using the Fleiss kappa coefficient, and the intraobserver reliability was measured using the Cohen's kappa coefficient. The new classification showed fair to substantial interobserver and intraobserver reliability, i.e., results comparable to the reliability of commonly used classification systems. The reliability was better for younger patients and when evaluation was carried out by hand-surgery-interested orthopedic surgeons. The new classification system is simple, covers all radial fracture types, and has an acceptable reliability. Further studies are needed to judge its ability to direct management and predict prognosis.

Case Studies to Demonstrate the Range of Applications of the Southampton Hand Assessment Procedure

The Southampton Hand Assessment Procedure (SHAP) was devised to assess quantitatively the functional range of injured and healthy adult hands. It was designed to be a practical tool for use in a busy clinical setting; thus, it was made simple to use and easy to interpret. This paper describes four examples of its use: before and after a surgical procedure, to observe the impact of an injury, use with prostheses, and during recovery following a fracture. The cases show that the SHAP is capable of monitoring progress and recovery, identifying functional abilities in prosthetic hands and comparing the capabilities of different groups of injuries.

Effect of an unrepaired fracture of the ulnar styloid base on outcome after plate-and-screw fixation of a distal radial fracture

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Tricalcium phosphate bone substitute in corrective osteotomy of the distal radius

AIM

To evaluate the outcome of using tricalcium phosphate (TCP) as void filler and structural support in corrective opening-wedge osteotomy of the distal radius.

METHODS

A consecutive series of 17 patients with malunited dorsally angulated distal radius fracture underwent corrective osteotomy using plates, screws and TCP blocks. Results were evaluated postoperatively with DASH at 6 months with radiography at 8-12 weeks and 0.5-3.5 years.

RESULTS

Mean DASH score improved from 52 (S.D. 22) preoperatively to 30 (S.D. 22) postoperatively. There was one non-union. There was also a mean loss of radial length of 1.1mm (S.D. 1.0mm) between the first postoperative radiograph and final follow-up. Radiolucent zones were observed around the TCP grafts after 6-8 weeks in 10/14 cases, but could not be statistically correlated with the slight loss of reduction.

CONCLUSIONS

TCP seems to be an alternative to iliac crest bone grafting in corrective osteotomies of the distal radius. The shortening observed over time may be attributable to inflammation induced by the TCP.

Assessment of distal radioulnar joint instability after distal radius fracture: comparison of computed tomography and clinical examination results

PURPOSE

To compare computed tomography (CT) and clinical stress test findings in terms of the assessment of distal radioulnar joint (DRUJ) instability after distal radius fracture.

METHODS

Thirty-four patients with a healed unilateral distal radius fracture were evaluated after a mean follow-up period of 18 months. Stress test and CT were performed to detect DRUJ instability. Three CT methods were used: the modified radioulnar line, the epicenter, and the radioulnar ratio methods. The results of CT assessments were compared with stress test findings using kappa statistics. Relationships between DRUJ instability and the radiographic parameters of volar tilt, radial inclination, and radial shortening were analyzed.

RESULTS

Twelve patients were considered to have DRUJ instability based on the stress test. DRUJ instability was diagnosed in 15, 8, and 11 patients by the modified radioulnar line, the epicenter, and the radioulnar ratio methods, respectively. Reliability analysis of stress test and CT results showed moderate or fair agreement (kappa value: .33 for the modified radioulnar line, .56 for the epicenter, .41 for the radioulnar ratio). DRUJ instability diagnosed by the stress test and by CT showed no statistical correlation with radiographic parameters, but instability determined by CT appeared to be related to dorsal tilt deformity.

CONCLUSIONS

After distal radius fracture, CT assessments of DRUJ instability were found to be influenced by residual deformities, such as dorsal tilt, but not well correlated with stress test findings. Although CT assessments are objective, CT scans primarily show alterations of DRUJ alignment and have several risks of bias in patients with a prior distal radius fracture.

Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation

BACKGROUND

Several techniques have been proposed to measure translation of the distal radioulnar joint on computed tomography scans, but the criteria for diagnosing abnormal subluxation have not been standardized. The aims of this study were to evaluate the reliability of the current methods and to derive normal population values with these methods.

METHODS

Computed tomography scans of forty-five asymptomatic wrists were performed with the hand in supination, neutral, and pronation. Four methods for diagnosing subluxation of the distal radioulnar joint were used: the radioulnar line method; the epicenter method; the radioulnar ratio method; and the subluxation ratio method, which is a modification of the radioulnar line method that involves use of a line perpendicular to the sigmoid notch. Three observers measured all of the scans independently and repeated the measurements three months later to determine the interobserver and intraobserver reliability. All of the measurements for each subject were averaged, and the average was considered to be the normal value for that subject.

RESULTS

Interobserver reliability was best (substantial to almost perfect) with use of the subluxation ratio method. The intraclass correlation coefficients showed substantial to almost perfect reliability of the radioulnar line method, substantial reliability of the radioulnar ratio method, and moderate to substantial reliability of the epicenter method. The intraobserver reliability of all methods was almost perfect. The radioulnar line and subluxation ratio methods always showed the ulnar head to be located outside of the dorsal line in pronation and outside of the volar line in supination. The normal epicenter values indicated that the center of rotation of the distal radioulnar joint fell in the middle half of the sigmoid notch in all positions. The normal ranges derived with the radioulnar ratio method demonstrated larger variation than originally reported.

CONCLUSIONS

This study suggests that the subluxation ratio method is the most useful technique for measuring translation of the distal radioulnar joint as a result of its reliability and simplicity. Substantial variations in normal values derived with the current methods should be considered in a computed tomography evaluation of the distal radioulnar joint in symptomatic patients.

Réparation du pronator quadratus par surjet aller-retour dans la voie de Henry

Repair of the quadratus pronator after osteosynthesis of the distal radius via the Henry approach is generally considered a difficult procedure. The quadratus pronator is a powerful muscle which stabilizes the distal radioulnar joint. The muscle is most often injured in association with distal fracture of the radius. Apposition osteosynthesis appears to be the most appropriate procedure in order to limit loss of reduction, i.e. distal radioular variance, observed in the first postoperative weeks. Tendon complications observed with dorsal approaches and the development of new volar plates with locking screws have offered new prospects for the Henry approach. We propose here a technique for repairing the pronator quadratus with an outward-return running suture using a 2.0 single-strand thread. The technique is designed to redistribute tension along the muscle borders progressively and precisely. Muscle integrity can thus be restored and the flexor system is isolated from the osteosynthesis material.

Surgical treatment of unstable distal radius fractures with volar locking plates

BACKGROUND

Surgical treatment of unstable distal radius fractures does not always yield a satisfactory outcome. The several surgical strategies available have problems associated with them. This study was undertaken to determine if volar locking plate fixation could be useful for treating unstable distal radius fractures.

METHODS

This retrospective follow-up study assessed 24 fractures in 24 patients with unstable distal radius fractures surgically treated with one of three volar locking plate systems. According to the AO classification system, 7 patients had type A3 fractures, 5 patients had type C2 fractures, and the remaining 12 patients had type C3 fractures. Radiographic measurements included volar tilt, radial inclination, and ulnar variance. Clinical outcomes were evaluated by active range of motion of the wrist and forearm, grip strength, Saito's wrist score, and the Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (JSSH version of the DASH).

RESULTS

At the time of final follow-up (5 months minimum) the mean volar tilt was 8.1 degrees , radial inclination was 20 degrees, and ulnar variance was 0.4 mm. Mean wrist extension measured 61 degrees, wrist flexion 55 degrees, radial deviation 23 degrees, ulnar deviation 35 degrees, pronation 87 degrees, and supination 87 degrees. Grip strength recovered to a mean of 84% of the grip strength in the contralateral limb for patients who had injured their dominant hand and to a mean of 73% for patients who had injured their nondominant hand. Saito's wrist score calculations revealed 20 excellent and 4 good results. The mean DASH disability/symptom score was 9.9 points, and the mean DASH work module score was 8.2 points.

CONCLUSIONS

The present study demonstrated that unstable distal radius fractures could be successfully treated with volar locking plate systems.

Predictors of functional outcomes after surgical treatment of distal radius fractures

PURPOSE

Identifying predictors of outcomes is important in anticipating and treating patients with underlying factors that may affect recovery. The predictors of functional outcomes after distal radius fracture (DRF) treatment have not been well defined in the past.

METHODS

This was a prospective cohort study designed to identify predictors of hand outcomes after DRF treatment. The study included consecutive patients with inadequately reduced DRFs who had open reduction and internal fixation with volar plating. Demographic and socioeconomic data were collected at the time of the initial treatment. Outcome data were collected 3, 6, and 12 months after surgery. Outcome evaluation consisted of radiographic measurements and the Michigan Hand Outcomes Questionnaire (MHQ). We hypothesized that the following factors are important predictors of functional outcomes: (1) age, (2) socioeconomic status, (3) severity of fracture pattern, and (4) postsurgical radiographic measurements. Regression models were developed using the overall MHQ score as the outcome variable at 3 months and 1 year after surgery.

RESULTS

Sixty-six patients had data available at 3 months and 49 patients had data available at 1 year. At 3 months after surgery, radiographic incongruity (step + gap) was a significant predictor after controlling for age, fracture type, dorsal-volar tilt angulation, and income. Patients with increased incongruity reported lower MHQ scores (worse functional outcomes). At 1 year after surgery, however, only age and income were significant predictors after controlling for fracture type. Increased age and decreased income were associated with lower MHQ scores.

CONCLUSIONS

After successful surgery and hand therapy, only age and income were significantly associated with long-term outcomes 1 year after surgery. Precise anatomic reduction enhances short-term functional outcomes in DRF treatment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic, Level I.

Sigmoid notch osteotomy for posttraumatic dorsal dislocation of the distal radioulnar joint: A case report

Instability of the distal radioulnar joint (DRUJ) is associated most commonly with injury to the soft-tissue restraints of that joint, particularly the triangular fibrocartilage complex. The dorsal rim of the sigmoid notch, however, also plays an important role as a bony restraint to dorsal subluxation. We report a case of posttraumatic dorsal dislocation of the DRUJ associated with a depressed fracture of the dorsal rim of the sigmoid notch. This was treated with soft-tissue release and corrective osteotomy of the dorsal rim of the sigmoid notch to restore DRUJ stability and congruency.

Arthroscopic management of distal radius fractures

Arthroscopy has the advantage of providing a direct and accurate assessment of the articular surfaces and detecting the presence of injuries associated with distal radius fractures. Current indications, although numerous and potentially expanding, also are controversial. This report presents a global view of the current status of arthroscopy in the management of distal radius fractures. The rationale of arthroscopic treatment, the available evidence, and finally the diagnosis and treatment are discussed.

Traitement des fractures du radius avec assistance arthroscopique

The orthopaedic surgeons cannot predict the functional results after a distal intra articular radius fracture. The intra-articular incongruity of more than 1 mm is associated with the development of secondary osteoarthrosis. The wrist arthroscopy became an essential help for the reduction of these fractures. The hand is normally in an upright position with a traction of approximately 4-5 kg which facilitates the reduction of the extra-articular fracture component. It is possible to use a technique of horizontal traction. The arthroscopy allows the reduction and control of the fixing of the various fragments, but also the treatment associated lesions associated. One randomized study, which compared 34 arthroscopically treated fractures with 48 openly treated, concluded that the arthroscopy-treated group had better outcome, better reduction, better grip strength and better range of motion than the openly treated group. The treatment of intra articular distal radius fractures with arthroscopic assistance is thus the guaranteeing of the most anatomical reduction of articular surface. It allows the diagnosis and the treatment of the associated lesions, decreases the peripheral fibrous scars of soft tissues by avoiding initially extensive approaches and finally gives better functional results.

Imaging of Ulnar-Sided Wrist Pain

Ulnar-sided wrist pain has long been a diagnostic problem, partly because of the complex anatomy and many possible causes of pain in this region. This article discusses anatomy, pathophysiology, and imaging appearance of the more common causes, including tears of the triangular fibrocartilage complex, disorders of the distal radioulnar joint, tears of the lunotriquetral ligament, disorders of the extensor carpi ulnaris tendon, disorders of the pisotriquetral joint, the impingement and impaction syndromes, and ulnar wrist masses. Along with clinical history and physical examination, imaging is important in evaluation of ulnar-sided wrist pain. Conventional radiographs, conventional arthrography, CT, MRI, and MR arthrography are useful modalities that are often used in concert to help guide diagnosis and treatment.

Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint

PURPOSE

Laboratory studies evaluating the importance of the stabilizing structures of the distal radioulnar joint (DRUJ) largely have been limited to static design. Clinically, dynamic loading seems to be an important component of DRUJ instability. This study was designed to evaluate the influence of dynamic loading on the stability of the DRUJ with foveal versus styloid triangular fibrocartilage complex (TFCC) disruptions in a laboratory setting.

METHODS

Twelve fresh-frozen cadaveric upper-extremity specimens were tested using a dynamic simulator to study the contributions of the 2 ulnar insertions of the TFCC to the dynamic stability of the DRUJ. The specimens were tested in 3 loading conditions (no load, agonist loading, antagonist loading) in 3 different states of the TFCC (intact, foveal disruption, styloid disruption).

RESULTS

Without load no significant differences were found for the different conditions of the TFCC. Under loaded conditions the foveal insertion had a greater effect on stability than did the styloid insertion. Under agonist loading significant differences were found during supinating and pronating motions. With antagonist loading a significant difference was found only during supination.

CONCLUSIONS

The study results support the clinical impression that dynamic loading is an important component of DRUJ instability and that disruption of the foveal TFCC insertion into the foveal region of the distal ulna can produce instability.

Distal radius fractures: a comparison of tension band wiring versus ulnar outrigger external fixation for the management of distal radioulnar instability

PURPOSE

To retrospectively compare the results of immobilization of the forearm in supination with the results of tension band fixation of the ulnar styloid in 35 patients with distal radius fractures, fracture of the base of the ulnar styloid, and distal radioulnar joint instability treated with external fixation.

METHODS

Thirty-five patients with fractures of the distal radius, fracture of the base of the ulnar styloid, and unstable distal radioulnar joint had external fixation with adjunctive percutaneous pins and allograft bone to reduce and stabilize the distal radius fracture anatomically. Only those patients with an associated ulnar styloid base fracture displaced over 2 mm with gross distal radioulnar joint instability relative to the contralateral wrist were included in this study. Group 1 consisted of patients in whom the ulnar styloid base fracture was treated with conventional tension band wiring techniques. Group 2 patients were treated with a supplemental outrigger from the external fixator to the ulna and locked in 60 degrees of forearm supination. Groups 1 and 2 had an average follow-up period of 40 and 36 months, respectively.

RESULTS

Group 2 had significantly better supination than group 1. In terms of functional outcome it was found that there was no significant difference for the Disabilities of the Arm, Shoulder, and Hand and the Gartland and Werley scores between the 2 treatment groups. There was a lower rate of complications and fewer secondary procedures were required in group 2. The incidence of distal ulna resection was 4 of the 35 patients (2 patients in each group).

CONCLUSIONS

Our results indicate that patients in whom the ulnar styloid can be reduced and maintained in supination can be treated effectively with fixed supination outrigger external fixation. This method resulted in a statistically significant improvement in supination and a lower rate of distal radioulnar joint complications, and it required fewer secondary procedures.