The influence of articular morphology on non-traumatic degenerative changes of the distal radioulnar joint. A radiographic study

A modified partial wedge-shaped metaphyseal ulnar osteotomy for the treatment of ulnar impaction syndrome with reverse oblique sigmoid notch

We describe a modified metaphyseal ulnar osteotomy to treat ulnar impaction syndrome with a reverse oblique sigmoid notch. Based on a computational analysis of radiographs, a modified wedge metaphyseal ulnar osteotomy was devised with its apex positioned at the ulnar styloid base to avoid impaction between the sigmoid notch and ulnar head. Subsequently, nine patients with ulnar impaction syndrome and a reverse oblique sigmoid notch underwent this operation, combined with arthroscopic exploration and transosseous triangular fibrocartilage complex repair. The mean follow-up was 14 months. All patients achieved bone union within 5 weeks, with no degenerative changes being observed during the follow-up assessments. The final follow-up assessments revealed decreases in ulnar variance and in the scores for Visual Analogue Scale, Quick Disabilities of the Arm, Shoulder and Hand questionnaire and the Patient-Rated Wrist Evaluation. All patients achieved excellent or good grades on the Modified Mayo Wrist Score. This technique is effective in treating the ulnar impaction syndrome with a reverse oblique sigmoid notch.Level of evidence: IV.

Stress distribution pattern in the distal radioulnar joint before and after ulnar shortening osteotomy in patients with ulnar impaction syndrome

Ulnar shortening osteotomy (USO) for ulnar impaction syndrome potentially leads to degenerative changes of the distal radioulnar joint (DRUJ). This study was performed to evaluate the effect of the sigmoid notch morphology on the stress distribution pattern of the DRUJ using computed tomography (CT) osteoabsorptiometry (CT-OAM). We reviewed the pre- and postoperative transverse CT images of 15 wrists that had undergone USO. The examined wrists were classified into two groups based on the sigmoid notch morphology: the linear-type notch (type L) and the curved-type notch (type C). We calculated and statistically compared the percentage of the high-density area (%HDA) in each divided region of the sigmoid notch. In type L, %HDA was significantly larger in the distal-dorsal region of the sigmoid notch before USO. Postoperatively, in type L, no specific regions showed a significantly different %HDA. In type C, %HDA was significantly larger in the distal-volar region of the sigmoid notch before USO. Postoperatively, %HDA of type C was significantly larger in the proximal-volar region. Our results suggest that in patients with ulnar impaction syndrome, morphological evaluation of the sigmoid notch can serve as a predictor of osteoarthritis in the DRUJ with or without USO.

Long-term radiographic outcomes and functional evaluation of ulnar shortening osteotomy in patients with ulnar impaction syndrome and reverse oblique sigmoid notch: a retrospective case series study

BACKGROUND

Ulnar shortening osteotomy (USO) is an effective treatment for ulnar impaction syndrome. However, there have been reports of osteoarthritis (OA) at the distal radioulnar joint (DRUJ) when USO was performed on patients with a reverse oblique sigmoid notch. This study aimed to evaluate the radiographic and functional outcomes following USO in patients with a reverse oblique sigmoid notch.

METHODS

We retrospectively reviewed patients having a reverse oblique sigmoid notch who underwent USO for ulnar impaction syndrome between 2002 and 2013. We evaluated radiographic changes of the DRUJ and functional outcomes of patients.

RESULTS

We enrolled 22 patients (22 wrists) with an average age of 49.6 years and a mean follow-up of 93.2 (range, 36-179; standard deviation [SD], 38.2) months. We found that there were changes in the inclination angle of the sigmoid notch, from an average reverse oblique of 14.9^o (range, 11^o-23^o; SD, 3.4^o) preoperatively to a more parallel 5.1^o (range, 0^o-11^o; SD, 3.2^o) at the final follow-up. The functional results at the final follow-up were good, with a mean visual analogue scale for pain of 0.2 (range, 0-1; SD, 0.4) at rest and 1.3 (range, 0-3; SD, 0.9) during activity, QuickDASH of 15.1 (range, 2.3-34.1; SD, 8.8), and modified Mayo Wrist Score of 91.6 (range, 70-100; SD, 6.4). Seven wrists (31.8%) had changes compatible with OA, but the wrists did not exhibit a significantly worse function when compared to wrists without OA changes, except for supination motion and grip strength.

CONCLUSIONS

For patients with a reverse oblique sigmoid inclination following USO, we observed that the inclination angle had a tendency to become parallel and some patients developed OA at the DRUJ. However, long-term functional outcomes could still be good. The reverse oblique sigmoid inclination does not seem to be an absolute contraindication for USO.

Morphology at the Distal Radioulnar Joint: Identifying the Prevalence of Reverse Obliquity

Background  Recent advances in the understanding of ulnar-sided wrist pathologies such as ulnar abutment syndrome (UAS) have brought increased attention to the anatomy of the distal radioulnar joint (DRUJ). Previous work established three anatomical variants of the sigmoid notch (parallel, oblique, and reverse oblique). The reverse oblique DRUJ poses theoretical risk of increased contact forces following ulnar shortening osteotomy, a common method of treating UAS. Purpose  As prevalence of reverse oblique morphology has been under-reported, this study aims to better define the prevalence of reverse oblique morphology in the adult population. Methods  Institutional Review Board-approved review of 1,000 radiographs over a 2-year period was performed. Demographic data and radiographic measurements were recorded (ulnar variance, notch inclination, and presence of arthritis). Correlation tests, a test of proportions, a t -test, and linear and logic regression tests were used to examine associations between ulnar variance, sigmoid inclination, sex, age, and presence of arthritis. Results  One thousand radiographs were analyzed revealing prevalence rates of: parallel-68%, oblique-26%, and reverse oblique-6%. Females were significantly more likely to have reverse inclination. No significant correlation was noted for morphology by age. Ulna positive variance was negatively correlated with reverse inclination. DRUJ arthritis was noted in 14% of patients. Higher sigmoid inclination was associated with higher odds of presence of arthritis, adjusting for sex and age. Higher incidence of arthritis was noted among patients with the oblique (20.8%) or reverse oblique (24.6%) compared with parallel (10.5%) morphology. Conclusion  This series of 1,000 radiographs demonstrates a 6% overall prevalence of reverse obliquity. This large dataset allows for better quantification of the prevalence of DRUJ morphologies and determination of correlations that have clinical implications for patients with ulnar-sided wrist pathology. Level of Evidence  This is a Level IV study.

The correlation between shape of the sigmoid notch of the distal radius and the risk of triangular fibrocartilage complex foveal tear

Aims

The aim of this study was to analyze the association between the shape of the distal radius sigmoid notch and triangular fibrocartilage complex (TFCC) foveal tear.

Methods

Between 2013 and 2018, patients were retrospectively recruited in two different groups. The patient group comprised individuals who underwent arthroscopic transosseous TFCC foveal repair for foveal tear of the wrist. The control group comprised individuals presenting with various diseases around wrist not affecting the TFCC. The study recruited 176 patients (58 patients, 118 controls). The sigmoid notch shape was classified into four types (flat-face, C-, S-, and ski-slope types) and three radiological parameters related to the sigmoid notch (namely, the radius curvature, depth, and version angle) were measured. The association of radiological parameters and sigmoid notch types with the TFCC foveal tear was investigated in univariate and multivariate analyses. Receiver operating characteristic curves were used to estimate a cut-off for any statistically significant variables.

Results

Univariate analysis showed that the flat-face type was more prevalent in the patients than in the control group (43% vs 21%; p = 0.002), while the C-type was lower in the patients than in the control group (3% vs 17%; p = 0.011). The depth and version angle of sigmoid notch showed a negative association with the TFCC foveal tear in the multivariate analysis (depth: odds ratio (OR) 0.380; p = 0.037; version angle: OR 0.896; p = 0.033). Estimated cut-off values were 1.34 mm for the depth (area under the curve (AUC) = 0.725) and 10.45° for the version angle (AUC = 0.726).

Conclusion

The proportion of flat-face sigmoid notch type was greater in the patient group than in the control group. The depth and version angle of sigmoid notch were negatively associated with TFCC foveal injury. Cite this article: Bone Joint J 2020;102-B(6):749–754.

Ulnar Shortening Osteotomy: Our Experience

Objective  The objective of the present study was to evaluate the clinical and radiographic results of our series regarding ulnar shortening osteotomy, as well as to briefly review the pathology, indications and surgical options of ulnocarpal conflict. Methods  We performed a retrospective analysis of consecutive patients who were treated with ulnar shortening osteotomy between January 2012 and June 2017 at our hospital. We clinically evaluated pain, articular range of motion, grip strength and functional outcomes using the quick-DASH questionnaire. We radiographically measured the pre- and postoperative ulnar variance and the shortening performed. Results  We identified eight operated patients, and it was possible to evaluate seven of them. Pain decreased in this population (visual analogue scale [VAS] score changed from 7 to 2.6, p  < 0.05), there was a decrease in quick-DASH (64 to 28, p  < 0.05) and we found a decrease in the articular amplitude ∼ 7° for flexion ( p  = 0.2), and of 5.5° for supination ( p  = 0.3), as well as decreasing grip strength to about 86% on the contralateral side ( p  = 0.07). The ulnar variance changed from a mean of + 5.5 mm to - 1.1 mm ( p  < 0.05). Two out of 8 patients (25%) presented plaque-related symptoms and one of them underwent a new intervention to extract the material. Conclusions  Ulnar shortening osteotomy is an effective surgical procedure both in the treatment of ulnocarpal conflict and in the discharge of the ulna. The results presented agreement with other results published in the literature, with good clinical and radiographic results.

Non-traumatic primary and secondary osteoarthritis of the distal radioulnar joint

A retrospective radiographic study was conducted to determine the prevalence and severity of non-traumatic primary and secondary osteoarthritis of the distal radioulnar joint in a group of 718 patients. Non-traumatic primary and secondary osteoarthritis was found in 77 patients (11%) with a mean age of 63 years. In 34 cases it was bilateral. Mild signs of osteoarthritis were present in 53, moderate in 17 and severe in seven patients. The prevalence of primary osteoarthritis was 8.2% and 2.5% had secondary non-traumatic osteoarthritis. The prevalence and severity of the osteoarthritis were similar in women and men. Ulnar wrist pain was associated with osteoarthritis of the distal radioulnar joint in 13% of patients with mild, 35% with moderate and 43% with severe radiological degeneration. Level of evidence: IV.

Distal radioulnar joint configurations in three-dimensional computed tomography in patients with idiopathic ulnar impaction syndrome

We retrospectively reviewed 26 patients diagnosed with idiopathic ulnar impaction syndrome and measured the slopes of the sigmoid notch and ulnar head at their centre using their preoperative three-dimensional computed tomography. We found that the slope of the sigmoid notch and that of the ulnar head were not parallel to each other. There was a significant linear relation between the slope of the ulnar head and the changes in the closest joint space of the distal radioulnar joint at the centre of the sigmoid notch after ulnar shortening. We conclude that the slope of the ulnar head is more strongly correlated with changes in the closest joint space in the distal radioulnar joint than that of the sigmoid notch. Our findings suggest that slope of the ulnar head might be as important a predisposing factor as that of the sigmoid notch for the progression of distal radioulnar joint arthritis after ulnar-shortening osteotomy. We should consider the slopes of both the sigmoid notch and ulnar head before the osteotomy. Level of evidence: IV.

Morphological characteristics of the sigmoid notch of the distal radius affect the stress distribution patterns in the distal radioulnar joint

The aim of this study was to clarify the effects of morphological patterns of the sigmoid notch on the stress distribution across the articular surface of the distal radioulnar joint using a computed tomography osteoabsorptiometry method. Fourteen wrists from 13 patients were classified into two groups according to the type of sigmoid notch, namely the 'C' type and ski-slope sigmoids, and the percentages of high-density areas on the articular surface were quantitatively analysed. The percentage of the high-density area of the dorsal region in the ski-slope sigmoid group was significantly greater than that of the 'C' type sigmoid group (16% vs 4.1%) and of the volar region of the ski-slope sigmoid group (16% vs 2.4%). The results indicate that bony morphological differences in the radial sigmoid notch affect the stress distribution pattern through the distal radioulnar joint.

Arthroscopic resection of an osteochondral loose body in the distal radioulnar joint: A case report

We report a 34-year-old man who presented with ulnar wrist pain, painful click, and locking during forearm rotation following a motorcycle accident. Plain radiographs showed a loose body in the distal radioulnar joint (DRUJ), deformity of the sigmoid notch and ulnar head, and ulnar minus variant. The DRUJ deformity was assumed to be associated with physeal injury of the distal ulna during childhood. Conservative treatment with a splint and oral analgesics for 3 months failed. During DRUJ arthroscopy, osteoarthritic changes were found, and the loose body was resected using DRUJ arthroscopy. Histological examination showed an osteochondral loose body. The patient remained asymptomatic without recurrence or DRUJ instability 2 years postoperatively.

Does Distal Radio-ulnar Joint Configuration Affect Postoperative Functional Results after Ulnar Shortening Osteotomy?

Background

Reverse oblique distal radio-ulnar joint (DRUJ) configuration is assumed to show inferior postoperative results in ulnar-shortening osteotomy due to osteoarthritis, as the joint force pressure in the DRUJ may be increased. An evaluation and comparison of the postoperative functional results with regard to clinical and radiographic signs of arthritis among different DRUJ configurations was carried out retrospectively.

Methods

Sixty-two patients after ulnar shortening osteotomy were included. The minimum follow-up was 5 years. Preoperative x-rays were assessed for the DRUJ configuration according to the Tolat classification, whereas postoperative radiographs were evaluated with regard to signs of osteoarthritis using the Kallgren-Lawrence-Score. Functional results were evaluated using the disabilities of the arm, shoulder and hand (DASH) and Mayo Wrist Score and measuring range of motion and grip strength.

Results

Significantly better functional results were found in patients with parallel configuration of the DRUJ (Tolat type 1 configuration) with regard to DASH score, grip strength, and supination compared with nonparallel configurations. In the Tolat type 1, configurated DRUJ mean DASH score was 9 compared with 18 in the Tolat type 2 and 3 groups. Apart from supination, no differences were observed in range of motion among groups.

Conclusion

Although long-term postoperative range of motion failed to display statistically significant differences between DRUJ configurations except for supination, better results regarding grip strength and DASH scores were seen in a parallel-aligned DRUJ configuration. Although onset of osteoarthritis does not seem to become apparent within the observation period, nonparallel aligned configuration predisposes to inferior results.

Morphological Associations between the Distal Radioulnar Joint and the Lunate

Background  Variations in morphology of the carpal bones have been described. Their implication in wrist disease and specific kinematic features has been recognized, and a better knowledge of these variations is essential. Questions/Purpose  To radiographically determine any association between the morphological variations of the distal radioulnar joint (DRUJ) and the lunate bone. Materials and Methods  Radiographs of 100 wrists of patients presenting to the emergency department with wrist pain and referred to our outpatient clinic were retrospectively reviewed for DRUJ inclination, ulnar variance, and radiocarpal and midcarpal morphology of the lunate. Results  There were 51 females and 49 males, mean age 51.2 years (range: 21-94). There was a statistically significant association between the DRUJ inclination and the morphology of the radiocarpal side of the lunate ( p  < 0.001). The mean values of ulnar variance changed according to DRUJ inclination and the radiocarpal side of the lunate ( p  < 0.001) but not according to the midcarpal side of the lunate. There was no significant association between the morphology of the DRUJ and the midcarpal side of the lunate or between the midcarpal and the radiocarpal morphology of the lunate. Conclusion  This study demonstrated a statistically significant association at the radiocarpal level between the DRUJ inclination, ulnar variance, and the morphology of the lunate. No association was found with the morphology of the midcarpal side of the lunate. Accordingly, a classification of these carpal associations is proposed, highlighting seven main wrist configurations. Clinical Relevance  These associations can guide future studies of wrist kinematics.

The influence of cartilage thickness at the sigmoid notch on inclination at the distal radioulnar joint

AIMS

The aims of this study were: firstly, to investigate the influence of the thickness of cartilage at the sigmoid notch on the inclination of the distal radioulnar joint (DRUJ), and secondly, to compare the sensitivity and specificity of MRI with plain radiographs for the assessment of the inclination of the articular surface of the DRUJ in the coronal plane.

PATIENTS AND METHODS

Contemporaneous MRI images and radiographs of 100 wrists from 98 asymptomatic patients (mean age 43 years, (16 to 67); 52 male, 53%) with no history of a fracture involving the wrist or surgery to the wrist, were reviewed. The thickness of the cartilage at the sigmoid notch, inclination of the DRUJ and Tolat Type of each DRUJ were determined.

RESULTS

The assessment using MRI scans and cortical bone correlated well with radiographs, with a kappa value of 0.83. The mean difference between the inclination using the cortex and cartilage on MRI scans was 12°, leading to a change of Tolat type of inclination in 66% of wrists. No reverse oblique (Type 3) inclinations were found when using the cartilage to assess inclination.

CONCLUSION

These data revealed that when measuring the inclination of the DRUJ using cartilage, reverse oblique inclinations might not exist. The data suggest that performing an ulna shortening osteotomy might be reasonable even in distal radioulnar joints where the plain radiographic appearance suggests an unfavourable reverse oblique inclination in the coronal plane. We recommend using MRI to validate radiographs in those that appear to be reverse oblique (Tolat Type 3), as the true inclination might be different, thereby removing one possible contraindication to ulnar shortening. Cite this article: Bone Joint J 2017;99-B:369-75.

Intra-articular Fractures of the Sigmoid Notch of the Distal Radius: Analysis of Progression to Distal Radial Ulnar Joint Arthritis and Impact on Upper Extremity Function in Surgically Treated Fractures

Background Studies have established an increased risk of radiocarpal joint posttraumatic arthritis in patients with displaced intra-articular fractures of the distal radius, although this phenomenon has yet to be evaluated in the distal radioulnar joint (DRUJ). Purpose We hypothesized that patients with displaced intra-articular fractures of the sigmoid notch would have a higher prevalence of DRUJ arthritis and greater upper extremity dysfunction after operative treatment of distal radius fractures compared with fractures without sigmoid notch involvement. We also hypothesized that the degree of sigmoid notch incongruity would be correlated with the grade of DRUJ arthritis and the severity of upper extremity dysfunction. Patients and Methods A retrospective review was conducted on surgically treated patients with distal radius fractures with pre- and/or postoperative computed tomography (CT) scans. Patients were divided into groups based on presence or absence of fracture extension into the sigmoid notch. Within the sigmoid notch group, postoperative CT scans were used to measure sigmoid notch fracture step-off and diastasis (mm), as well as volar or dorsal DRUJ subluxation (%). Patients were administered Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaires and radiographs were obtained to grade DRUJ arthritis using the Kellgren-Lawrence (KL) radiographic criteria. Results Thirty-three patients were included (19 with sigmoid notch involvement and 14 without) with an average radiographic follow-up of 6.3 years (range: 3.5-10.1 years). DASH scores were available for all patients, and radiographic follow-up was available in 24 patients (73%). A trend toward higher grade of DRUJ arthritis and poorer average DASH was found in those with sigmoid notch involvement, but was not statistically different. In the sigmoid notch group there were poorer DASH scores in patients with coronal step-off > 1.0-mm (p < 0.05). There were no significant correlations between sigmoid notch step-off, diastasis or DRUJ subluxation and either KL grade of arthritis or DASH scores. Conclusion Fractures involving the sigmoid notch did not appear to have a greater prevalence of DRUJ posttraumatic arthritis in operatively treated patients at greater than 6 years of follow-up. Postoperative sigmoid notch step-off, diastasis or DRUJ subluxation had a minimal effect on upper extremity function, but fractures with a coronal step-off of > 1.0-mm exhibited higher levels of upper extremity dysfunction. Level of Evidence Prognostic, Level III-Case control.

Ulnar Shortening Osteotomy After Distal Radius Fracture Malunion: Review of Literature

Malunion of distal radius fracture is often complicated with shortening of the radius with disturbed radio- ulnar variance, frequently associated with lesions of triangular fibrocartilage complex and instability of the distal radioulnar joint. Positive ulnar variance may result in wrist pain located in ulnar part of the joint, limited ulnar deviation and forearm rotation with development of degenerative changes due to the overloading that occurs between the ulnar head and corresponding carpus. Ulnar shortening osteotomy (USO) is the standard procedure for correcting positive ulnar variance. Goal of this procedure is to minimize the symptoms by restoring the neutral radio - ulnar variance. In this paper we present a variety of surgical techniques available for ulnar shorthening osteotomy, their advantages and drawbacks. Methods of ulnar shortening osteotomies are divided into intraarticular and extraarticular. Intraarticular method of ulnar shortening can be performed arthroscopically or through open approach. Extraarticular methods include subcapital osteotomy and osteotomy of ulnar diaphysis, which depending on shape can be transverse, oblique, and step cut. All of those osteotomies can be performed along wrist arthroscopy in order to dispose and treat possibly existing triangular fibrocartilage complex injuries. At the end we described surgical procedures that can be done in case of ulnar shorthening osteotomy failure.

Comparison of plain x-rays and computed tomography for assessing distal radioulnar joint inclination

PURPOSE

To compare the inclination of the distal radioulnar joint (DRUJ) on computed tomography (CT) and plain radiography (XR) in order to assess the effect of narrowing the range of inclination used in the original Tolat classification system to identify potentially problematic reverse oblique DRUJs.

METHODS

Two independent investigators compared the angle of inclination and Tolat type on matched wrist XRs in the coronal plane and CTs of the same patients with normal DRUJs. The degree of agreement between XR and CT was determined. Inter- and intra-observer reliabilities were calculated. The prevalence of the 3 inclination types of the DRUJs using Tolat's definition was recorded. Their original quantitative definition of the parallel Tolat type 1 DRUJ included all DRUJs with a measured inclination of ±10°. We noted and compared the resultant changes in prevalence of the different DRUJ types after narrowing the inclination range to ±5° and ±3°.

RESULTS

Highly significant correlation between CT and XR measurements were found for both observers. Despite this, the limits of agreement between CT and XR in determining the sigmoid notch inclination was -9° to 11° (±2° standard deviations from the mean difference). When measured from the CTs and using Tolat's original algorithm, the prevalence of Tolat type 1 DRUJ was 47% (N = 34), type 2 was 51% (N = 37), and type 3 was 1% (N = 1). These percentages changed to 7% (N = 5) for type 1, 78% (N = 56) for type 2, and 15% (N = 11) for type 3 when applying narrower ranges of inclination.

CONCLUSIONS

Narrowing the range of sigmoid notch inclination that defines type 1 (parallel) DRUJs when using CT provided a more accurate representation of the morphological types. It revealed an increased number of potentially problematic type 3 DRUJs. However, the statistical limits of agreement between CT and XR suggested that high-resolution 3-dimensional imaging is required to apply the new algorithm.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Ulnar shortening osteotomy for ulnar-sided wrist pain

Background The purpose of ulnar shortening osteotomy is literally to shorten the ulna. It can tighten the triangular fibrocartilage complex (TFCC), ulnocarpal ligaments, and interosseous membrane. Nowadays, this method is used to treat ulnar-sided wrist pain, for which we have also started to use a treatment algorithm. The purpose of this study was to review the long-term and clinical results based on our algorithm. Materials and Methods We retrospectively reviewed 30 patients with ulnocarpal impaction syndrome after a minimum follow-up of 5 years (Group A) and then retrospectively evaluated 66 patients with recalcitrant ulnar wrist pain treated based on our algorithm (Group B). Description of Technique Ulnocarpal abutment was confirmed arthroscopically. The distal ulna was approached through a longitudinal incision between the extensor carpi ulnaris and flexor carpi ulnaris. We performed a transverse resection of the ulna fixed with a small locking compression plate. The contralateral side served as the reference for the length of shortening (mean, 2.4 mm; range, 1-5 mm). Disappearance of ulnar abutment was then confirmed again arthroscopically. Results (Group A) Most patients showed good long-term clinical results. About half of the patients showed a bony spur at the distal radioulnar joint (DRUJ), but the clinical results did not significantly correlate with presence of bony spurs. Radiological parameters wre not related to the presence of bony spurs. (Group B) Twenty-four of the 66 patients investigated prospectively underwent an ulnar shortening osteotomy, with all showing good clinical results at 18 months postoperatively. Conclusions Ulnar shortening osteotomy can change the load of the ulnar side of the wrist and appears useful for ulnar-sided wrist pain in the presence of ulnar impaction. Level of evidence IV.

Clinical, radiographic, and arthroscopic outcomes after ulnar shortening osteotomy: a long-term follow-up study

PURPOSE

Previous studies have investigated the long-term outcomes of ulnar shortening osteotomy (USO) in the treatment of ulnocarpal abutment syndrome (UCA), but none have used arthroscopic assessments. The purpose of this study was to investigate the long-term clinical outcomes of USO with patient-based, arthroscopic, and radiographic assessments.

METHODS

We retrospectively reviewed 30 patients with UCA after a minimum follow-up of 5 years, with arthroscopic evaluations at the time of both USO and plate removal. We confirmed the initial diagnosis of UCA by radiography and arthroscopy. Mean age at the time of index surgery was 37 years. Mean duration of follow-up was 11 years (range, 5-19 y). We obtained Disabilities of the Arm, Shoulder, and Hand and Hand20 self-assessments postoperatively for all patients. Bony spur formation was evaluated postoperatively from plain radiographs.

RESULTS

We detected triangular fibrocartilage complex (TFCC) disc tear in 13 wrists arthroscopically at the time of USO. Of these, 10 showed no evidence of TFCC disc tear at second-look arthroscopy. The remaining 17 cases showed no TFCC disc tear at either first- or second-look arthroscopy. Follow-up radiography revealed that bony spurs at the distal radioulnar joint had progressed in 13 wrists. Disabilities of the Shoulder, Arm, and Hand and Hand20 scores did not significantly correlate with the presence of bony spurs or TFCC disc tears. Range of motion decreased significantly with age only. Lower grip strength correlated with bony spur and lower radial inclination. Triangular fibrocartilage complex tear, male sex, and advanced age were associated with lower Disabilities of the Shoulder, Arm, and Hand and Hand20 scores.

CONCLUSIONS

Ulnar shortening osteotomy achieved excellent long-term results in most cases. Most TFCC disc tears identified at the initial surgery had healed by long-term arthroscopic follow-up. We suggest that UCA with a TFCC disc tear is a good indication for USO.

Sonographically guided distal radioulnar joint injection: technique and validation in a cadaveric model

Distal radioulnar joint (DRUJ) disorders are uncommon but important causes of ulnar-sided wrist pain and disability. Fluoroscopically guided injections may be performed to diagnose or treat DRUJ-related pain or as part of a diagnostic arthrogram. Sonographic guidance may provide a favorable alternative to fluoroscopic guidance for distal DRUJ injections. This report describes and validates a sonographically guided technique for DRUJ injections in an unembalmed cadaveric model. An experienced clinician used sonographic guidance to inject diluted colored latex into the DRUJs of 10 unembalmed cadaveric specimens. Subsequent dissection by a fellowship-trained hand surgeon confirmed accurate injections in all 10 specimens. Two cases of ulnocarpal flow, indicative of triangular fibrocartilage injury, were noted during injection and subsequently confirmed during dissection. Clinicians should consider using sonographic guidance to perform DRUJ injections when clinically indicated. Further research should explore the efficacy of sonographically guided DRUJ injections to treat patients with painful DRUJ syndromes or to evaluate the triangular fibrocartilage complex in patients with ulnar wrist pain syndromes.

Normal ultrasound anatomy of the triangular fibrocartilage of the wrist: a study on cadavers and on healthy subjects

PURPOSE

To report the normal sonographic anatomy of the triangular fibrocartilage (TFC) of the wrist in cadavers and volunteers.

METHOD

Five hands from cadavers were examined sonographically before and after wrist dissection, during which the TFC was marked with surgical wires. Twenty volunteers without wrist limitation or pain, and without any history of wrist disease or inflammatory arthritis (mean age, 26 years (range,19-45 years) were also examined.

RESULTS

Sonograms showed that the meniscus and the TFC were clearly separated. The meniscus appeared as a triangular structure that was homogeneous and slightly hyperechoic. Compared with the meniscus, the TFC appeared hypoechoic. The same patterns were observed for cadavers and volunteers. In 3 volunteers (15%), the TFC was not visualized.

CONCLUSIONS

Using high-resolution ultrasound systems, the TFC can be separated from meniscus. However, visualization of the TFC remains limited due to its deep location and the presence of acoustic shadowing from bony structures.

Factors affecting results of ulnar shortening for ulnar impaction syndrome

Although ulnar shortening osteotomy is the most frequently performed operation for ulnar impaction syndrome, little attention has been given to detect certain preoperative factors affecting clinical outcomes of this procedure. We asked whether preoperative factors influenced the postoperative score of ulnar shortening osteotomy combined with arthroscopic debridement of the triangular fibrocartilage complex. We retrospectively reviewed 51 patients (53 wrists) with ulnar impaction syndrome treated with this procedure. There were 28 males and 23 females ranging in age from 14 to 67 years (mean, 37.5 years). The minimum followup was 12 months (mean, 26.3 months; range, 12-95 months). At last followup, we determined a modified Mayo wrist score for each patient. Preoperative factors affecting the clinical score were identified using multiple regression analysis. The clinical score ranged from 40 to 100 points (mean, 84.5 points). A long duration of symptoms and workers' compensation predicted worse clinical scores. We recommend considering these two factors when deciding whether to perform this procedure.