Importance of distal radioulnar joint arthroscopy for evaluating the triangular fibrocartilage complex

Do triangular fibrocartilage complex foveal injuries affect the clinical outcome of ulnar shortening osteotomy for ulnar impaction syndrome?

BACKGROUND

Ulnar shortening osteotomy (USO), as its name implies, is used to shorten the ulna. It subsequently tightens the triangular fibrocartilage complex (TFCC) and ulnar wrist. TFCC foveal insertion is a primary stabilizer of the distal radioulnar joint. It is unclear whether USO is effective in TFCC foveal injuries. The purpose of this study was to review the clinical outcomes of ulnar shortening osteotomies with and without TFCC foveal injuries.

METHODS

We retrospectively reviewed patients with ulnar wrist pain treated with USO and wrist arthroscopy including the distal radioulnar joint (DRUJ). Sixty-five patients were included in this study. An algorithm was used to guide surgical decision-making. After arthroscopic confirmation of ulnar impaction syndrome, we performed USO with a locking compression plate (mean length of shortening, 2.7 mm; range, 1-7.5 mm). The flattened TFCC disc due to ulnar shortening was confirmed arthroscopically. If the DRUJ was unstable after USO, we repaired the TFCC foveal insertion.

RESULTS

There were 32 post-traumatic and 33 idiopathic cases. We detected TFCC disc injuries in 34 wrists and TFCC foveal injuries in 33 wrists; both types were found in 15 wrists. TFCC foveal injuries were not significantly correlated with patient age, history of trauma, or clinical outcome. Most patients showed good clinical outcomes; 31 of 65 patients had preoperative DRUJ instability, with a significant number having foveal but not disc injuries.

CONCLUSION

USO achieved reasonable outcomes, even in patients with TFCC foveal injuries. In cases demonstrating ulnar impaction, USO should be prioritized over TFCC repair.

Dry Arthroscopy Distal Radioulnar Joint and Foveal Insertion: Surgical Technique

Background  Arthroscopy of the distal radioulnar joint is considered to be difficult to perform. At this time the integrity of the foveal insertion is indirectly evaluated with a hook test. If a hook test is positive it is inferred that the foveal insertion is torn or incompetent. Description of Technique  The ideal way to evaluate the foveal insertion is by direct visualization and probing. In order to do this, arthroscopic examination of the distal radioulnar joint and foveal insertion is required. The article describes how to reliably perform "dry" arthroscopy of the distal radioulnar joint and foveal insertion using a 1.9 mm arthroscope to accurately assess the triangular fibrocartilage complex and foveal insertion. Patient and Methods  A total of 169 dry DRUJ arthroscopies were performed by the primary author between January 2018 and February 2021. Results  Using this technique, the foveal insertion was successfully visualized in 168 cases (99%). Conclusion  Dry arthroscopy of the DRUJ is a reliable technique to evaluate the integrity of the foveal insertion.

Comparative outcomes between all-inside arthroscopic suture anchor technique versus arthroscopic transosseous suture technique in patients with triangular fibrocartilage complex tear: a retrospective comparative study

Background

Triangular fibrocartilage complex (TFCC) has become an interest over the last few decades, discovering its understanding in anatomy, pathomechanism, biomechanics, and management in treatments. Currently, TFCC does not have a golden standard procedure, and not one surgical procedure is superior to the other. This study is to evaluate the comparative outcomes in TFCC patients that underwent either in all-inside arthroscopic suture anchors or the arthroscopic transosseous suture technique.

Method

From 2017 to 2019, 30 patients were analyzed. Eight patients were in an arthroscopic transosseous group and 22 patients were in an all-inside arthroscopic group. Comparison between patients’ flexion and extension range of motion (ROM), grip strength, and visual analog pain scale (VAS) preoperative and six-month follow-up were analyzed.

Result

There were significant increases in flexion ROM, extension ROM, and VAS between preoperative and postoperative in all-inside arthroscopic and arthroscopic transosseous. Only the all-inside arthroscopic group had a significant increase in grip strength. Postoperative flexion ROM had a significant difference between all-inside arthroscopic and arthroscopic transosseous.

Conclusion

Both the all-inside arthroscopic suture anchor technique and the arthroscopic transosseous suture technique are appropriate treatments to treat patients with TFCC. Both procedures have achieved the ultimate goal of improved longevity and optimal function.

Level of evidence

Level III; retrospective comparative cohort study.

Accuracy of magnetic resonance imaging of the wrist for clinically important lesions of the major interosseous ligaments and triangular fibrocartilage complex; correlation with radiocarpal arthroscopy

OBJECTIVE

To demonstrate the utility of MRI in separating clinically relevant from minor or incidental lesions of the triangular fibrocartilage complex and the major interosseous ligaments in the wrist.

MATERIALS AND METHODS

In this retrospective study, we identified 89 patients and correlated MRI finding with subsequent arthroscopy. Triangular fibrocartilage complex abnormalities have been subdivided into disc lesions-central and radial-or ulnar-sided tears according to MRI appearances and surgical findings as the clinical and surgical approach is very different. Interosseous ligament tears were subdivided into partial or complete, highlighting the principle of recognising surgically relevant lesions.

RESULTS

For simple central to radial tears and perforations of the triangular fibrocartilage complex, MRI was 98.3% accurate. MRI identified all peripheral triangular fibrocartilage complex tears seen at arthroscopy; however, the specificity of 66.7% may reflect partly the use of arthroscopy limited to the radiocarpal joint. MRI proved 95.4% accurate for surgically relevant scapholunate interosseous ligament tears and was highly accurate at separating limited from complete lunotriquetral interosseous ligament tears showing 100% accuracy for complete tears.

CONCLUSIONS

The study shows excellent correlation between MRI and arthroscopic findings that determine surgical relevance with a very high sensitivity for triangular fibrocartilage complex lesions and accurate separation of minor versus surgically relevant ligamentous tears.

Displaced Flap Tears of the Triangular Fibrocartilage Complex: Frequency, Flap Location, and the "Comma" Sign on Wrist MRI

The purposes of this study were to estimate the frequency of displaced triangular fibrocartilage complex (TFCC) tears and to describe their MRI characteristics. The total of 3411 wrist MRI examinations assessed showed 20 displaced TFCC tears in 17 patients (frequency, 0.5%). These flaps were characteristically connected to the TFCC via a pedicle ("comma" sign) in 19 of 20 cases and displaced into the distal radioulnar joint also in 19 of 20 cases. Management implications were considered.

Arthroscopic thermal stabilization for distal radioulnar joint instability: 3 to 19 years follow-up

This retrospective study investigated the clinical outcomes of patients treated for chronic distal radioulnar joint instability with arthroscopic thermal annealing of the superficial radioulnar ligaments, ulnar palmar wrist ligaments, and dorsoulnar wrist capsule using a radiofrequency probe. Sixty patients (62 wrists) were treated over an 18-year period. At mean follow-up of 10 years (range 3 to 19), 30 of 33 patients were satisfied with their surgical outcomes. There were statistically significant improvements in ulnar-sided wrist pain on a visual analogue scale and in distal radioulnar joint stability on the dorsopalmar stress test after surgery compared with preoperative status. The modified Mayo Wrist Score and Quick Disabilities of the Arm, Shoulder, and Hand score of the patients were favourable. Early failure occurred in 11 of 62 wrists. Nine of these 11 wrists needed a secondary procedure. We conclude that arthroscopic thermal shrinkage is effective for the majority of the patients with mild to moderate chronic distal radioulnar joint instability in long-term follow-up. Secondary open ligament reconstruction is an option in the case of early failure.Level of evidence: IV.

[Arthroscopy of the distal radioulnar joint]

OBJECTIVE

The aim of the procedure is to visualize the proximal pouch of the DRUJ, the joint surfaces of the sigmoid notch and the ulnar head, the convexity of the ulnar head and the proximal ulnar side surface of the triangular fibrocartilage complex (TFCC).

INDICATIONS

Arthroscopy of the distal radioulnar joint is applied for the evaluation of joint pathologies in ulnar-sided wrist pain, especially in cases without diagnostic findings in standard X‑rays and MRIs and arthroscopically assisted procedures.

SURGICAL TECHNIQUE

In vertical extension, two portals of the wrist are created on the dorsal side of the DRUJ between the extensor digiti minimi and extensor carpi ulnaris tendons. By insertion of a small joint arthroscope via these portals visualization of the ulnar head, the sigmoid notch, the proximal pouch of the DRUJ and the proximal surface of the TFCC is accomplished.

CONCLUSIONS

Arthroscopy of the DRUJ is a rarely and not routinely performed procedure for the diagnosis and therapy of ulnar-sided wrist pain. It is technical demanding with a flat learning curve and anatomy-related obstacles. A complete view of the joint is not always accessible. Rare complications are injuries of the extensor digiti minimi tendon, as well as contusion or sectioning of the transverse branch of the dorsal branch of the ulnar nerve. In distinct cases, this procedure offers important additional information about the distal radioulnar joint. The procedure is especially valuable for the detection of proximal TFCC injuries that are missed otherwise.

The Prevalence of Triangular Fibrocartilage Complex Signal Abnormalities on Magnetic Resonance Imaging Relative to Clinical Suspicion of Pathology

PURPOSE

To determine the prevalence of triangular fibrocartilage complex (TFCC) signal changes in patients undergoing magnetic resonance imaging (MRI) of the wrist and its relationship to a clinical suspicion of TFCC pathology. The secondary purpose was to study factors that are associated with TFCC signal changes.

METHODS

In this retrospective study, we looked for any TFCC signal changes in the reports of MRI findings performed during a 3-year period in 1,134 patients. Demographic characteristics, the categorized indications for MRI, and symptoms at the time of the MRI were also retrieved from the medical records. Patients were divided into 6 groups, based on age, to calculate the proportions of TFCC signal changes in the entire cohort and as an incidental finding among patients without a clinical suspicion of TFCC pathology within each age group.

RESULTS

A total of 321 patients (28%) had incidental TFCC signal changes. The prevalence among 18- to 30 year-olds was 19%, and increased to 64% in patients older than 70 years. Multivariable logistic regression analysis demonstrated that an increase in age is significantly associated with having TFCC signal changes on MRI in patients who have a low clinical suspicion of TFCC pathology. The rate of incidental TFCC signal changes steadily increases with age.

CONCLUSIONS

The TFCC signal abnormalities on MRI are more common with increasing age in patients with low clinical suspicion of TFCC pathology. At age 70, more than half of all patients will have TFCC signal changes, and more than 90% are present in patients with a low clinical suspicion of TFCC pathology.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Chronologic and Geographic Trends of Triangular Fibrocartilage Complex Repair

This article shows trends in triangular fibrocartilage complex (TFCC) repair since 1990 by geographic area and year. The repair methods presented in the literature were inside-out, outside-in, all-inside, and open repair. The outside-in technique was reported most often for ulnar-side tears, whereas the inside-out technique was reported most frequently for radial-side tears. Recently, a foveal reattachment technique for ulnar-side tears has garnered attention and has been reported with increasing frequency, especially in Asia, because the deepest portion of TFCC, attached to fovea, plays a key role in stabilizing the distal radioulnar joint. Understanding these trends can help clinicians best treat TFCC tears.

Preventable Repeat Wrist Arthroscopies: Analysis of the Indications for 133 Cases

Background Frequently, patients undergo repeated wrist arthroscopies for single wrist problems. Purpose The purposes of this study were to assess the indications for repeat wrist arthroscopies and to identify potentially preventable procedures. Methods For this retrospective, two-center study, the electronic patient records were examined for patients, who underwent repeat wrist arthroscopy in a 5-year period. The cases were sorted by the underlying pathologies and the causes that necessitated repeat arthroscopies. Results Ulnar-sided wrist pain accounted for 100 (77%) of all 133 revision arthroscopies: 67 of which due to suspected ulnar triangular fibrocartilage complex (TFCC) avulsions, 33 due to ulnar impaction syndromes. Cartilage was reassessed in 22 (17%) wrists. Thereby, insufficient preoperative diagnostics necessitated pure diagnostic before therapeutic arthroscopy in 49 (37%) wrists: 48 of which for TFCC pathologies, one for a scapholunate (SL) ligament lesion. The uncertainty of diagnosis despite previous arthroscopy necessitated 18 (14%) revision arthroscopies: 15 for ulnar TFCC avulsions, 1 for a central TFCC lesion, 2 to reevaluate the SL ligament. Inadequate photo or video documentation of the cartilage necessitated arthroscopic reassessment in 16 (12%) wrists. Conclusion In this series, two out of three revision arthroscopies could potentially have been prevented. Inadequate preoperative diagnostics with the lack of reliable preoperative diagnoses necessitated pure diagnostic arthroscopies for ulnar-sided wrist pain. However, even arthroscopically, the diagnosis of ulnar TFCC avulsions or SL ligament lesions is not trivial. Surgical skills and experience are necessary to detect such lesions. Finally, adequate photo or video documentation may prevent repeated arthroscopic diagnostic procedures. Level of Evidence Level IV.

Arthroscopic-assisted repair of triangular fibrocartilage complex foveal avulsion in distal radioulnar joint injury

BACKGROUND

Disruption of the triangular fibrocartilage complex (TFCC) foveal insertion can lead to distal radioulnar joint (DRUJ) instability accompanied by ulnar-sided pain, weakness, snapping, and limited forearm rotation. We investigated the clinical outcomes of patients with TFCC foveal tears treated with arthroscopic-assisted repair.

MATERIALS AND METHODS

Twelve patients underwent foveal repair of avulsed TFCC with the assistance of arthroscopy between 2011 and 2013. These patients were followed up for an average of 19 months (range 14-25 months). The avulsed TFCC were reattached to the fovea using a transosseous pull-out suture or a knotless suture anchor. At the final followup, the range of motion, grip strength and DRUJ stability were measured as objective outcomes. Subjective outcomes were assessed using the Visual Analog Scale (VAS) for pain, patient rated wrist evaluation (PRWE), Disabilities of the Arm, Shoulder and Hand questionnaire (DASH score) and return to work.

RESULTS

Based on the DRUJ stress test, 5 patients had normal stability and 7 patients showed mild laxity as compared with the contralateral side. Postoperatively, the mean range of pronation supination increased from 141° to 166°, and the mean VAS score for pain decreased from 5.3 to 1.7 significantly. The PRWE and DASH questionnaires also showed significant functional improvement. All patients were able to return to their jobs. However, two patients complained of persistent pain.

CONCLUSIONS

Arthroscopically assisted repair of TFCC foveal injury can provide significant pain relief, functional improvement and restoration of DRUJ stability.

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.

Update TFCC: histology and pathology, classification, examination and diagnostics

The TFCC is a crucial stabilizer of the DRUJ. Based on its superficial and deep fibers, the TFCC guarantees unrestricted pronation and supination which is essential for performing sophisticated tasks. The ability to perform complex movements is of uppermost importance for hand function. Therefore, a functional intact TFCC is a prerequisite in this context. The articular disc of the TFCC is a fibrocartilaginous extension of the superficial zone of hyaline articular cartilage which arises from the radius. The peripheral 10-40 % of the TFC is vascularized. Degeneration of the articular disc is common with increasing age. Even though the central part of the articular disc is avascular, potential regeneration of lesions could be detected. The Palmer and Atzei classifications of TFCC lesions are complementary. TFCC innervation is based on different nerves. There is a high variability. A diligent clinical examination facilitates specific tests which help to allocate symptoms to the pathology. Therefore, a thorough clinical examination is not dispensable. Wrist arthroscopy remains the "gold standard" for diagnosing TFCC pathologies despite technical progress in imaging modalities. MR arthrography may have the potential to become a real alternative to wrist arthroscopy for diagnosing TFCC pathologies with technical progress in the future.

[Standard wrist arthroscopy: technique and documentation]

OBJECTIVE

Minimally invasive approach to the wrist in order to diagnose and treat different wrist pathologies.

INDICATIONS

Diagnosis of unclear chronic pain syndromes, cartilage status, intra-articular ligament structures as well as post-traumatic and inflammatory conditions of the wrist. Treatment of ulnar impaction syndrome, dorsal ganglia and also in fracture treatment and various different wrist interventions.

CONTRAINDICATIONS

Soft tissue infections around the wrist, severe scarring may impede access to the joint.

SURGICAL TECHNIQUE

Supine position with the forearm upright and in neutral position, the elbow flexed by 90°, axial traction of 3-4 kg. Superficial stab incision, blunt preparation through joint capsule, insertion of optic through 3-4 portal and probe through 4-5 portal, and radial and ulnar midcarpal portals, respectively. Either sodium chloride, CO2 or air is used as arthroscopy medium. Diagnostic round with standardized examination of all parts of the joint. Standardized written and high quality photo and/or video documentation to facilitate understandability of the findings.

POSTOPERATIVE MANAGEMENT

Forearm cast for 1 week, limited load for 2 more weeks, then load is increased to normal.

Prevalence of triangular fibrocartilage complex abnormalities regardless of symptoms rise with age: systematic review and pooled analysis

BACKGROUND

Triangular fibrocartilage complex abnormalities seem to be more common with age, but the degree to which this is so, and the degree to which the presence of an abnormality is associated with symptoms, are topics of controversy.

QUESTIONS/PURPOSES

We wished to perform a systematic review to determine the prevalence of triangular fibrocartilage complex abnormalities, and to determine if the prevalence of abnormalities are greater with increasing age. In addition, we stratified age groups based on symptoms.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library through August 15, 2013. Studies that reported triangular fibrocartilage complex abnormalities by age were included. Fifteen studies including 977 wrists met our criteria and reported a total of 368 (38%) triangular fibrocartilage complex abnormalities. Eight studies included symptomatic patients; the remainder studied cadavers (six studies) or asymptomatic volunteers (one study). Patients were divided into four age groups (< 30, 30-49, 50-69, and 70 years and older) for pooled analysis, comparing the proportions of patients with and without abnormalities between groups using chi-square analysis. We also evaluated the proportions after stratifying each age group by symptoms.

RESULTS

Overall, the prevalence of triangular fibrocartilage complex abnormalities increased with age, from 27% (80/301) in patients younger than 30 years to 49% (130/265) in patients 70 years and older (p < 0.001), odds ratio (OR), 2.7, 95% CI, 1.9-3.8 (p < 0.001). In asymptomatic patients, triangular fibrocartilage complex prevalence abnormality increased from 15% (24/159) to 49% (129/263) in the same age groups (p < 0.001), OR, 5.4, 95% CI, 3.3-8.9 (p < 0.001). For symptomatic patients prevalence ranged from 39% (56/142) to 70% (14/20) in patients between 50 and 69 years old (p < 0.034), OR, 3.6, 95% CI, 1.3-9.9 (p < 0.014).

CONCLUSION

Triangular fibrocartilage complex abnormalities are common in symptomatic and asymptomatic wrists, and they are increasingly common with age. As in all situations where abnormalities are so common that they may be incidental, we need (1) a reliable and accurate method for determining whether these abnormalities are the cause of symptoms; and (2) evidence that treatment of these abnormalities improves symptoms better than placebo.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

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.

Simple debridement has little useful value on the clinical course of recalcitrant ulnar wrist pain

The purpose of this study was to evaluate treatment results following arthroscopic triangular fibrocartilage complex (TFCC) debridement for recalcitrant ulnar wrist pain. According to the treatment algorithm, 66 patients (36 men and 30 women with a mean age of 38.1 years (15 to 67)) with recalcitrant ulnar wrist pain were allocated to undergo ulnar shortening osteotomy (USO; n = 24), arthroscopic TFCC repair (n = 15), arthroscopic TFCC debridement (n = 14) or prolonged conservative treatment (n = 13). The mean follow-up was 36.0 months (15 to 54). Significant differences in Hand20 score at 18 months were evident between the USO group and TFCC debridement group (p = 0.003), and between the TFCC repair group and TFCC debridement group (p = 0.029). Within-group comparisons showed that Hand20 score at five months or later and pain score at two months or later were significantly decreased in the USO/TFCC repair groups. In contrast, scores in the TFCC debridement/conservative groups did not decrease significantly. Grip strength at 18 months was significantly improved in the USO/TFCC repair groups, but not in the TFCC debridement/conservative groups. TFCC debridement shows little benefit on the clinical course of recalcitrant ulnar wrist pain even after excluding patients with ulnocarpal abutment or TFCC detachment from the fovea from the indications for arthroscopic TFCC debridement.

Various patterns of traumatic triangular fibrocartilage complex tear

We demonstrate various patterns of traumatic triangular fibrocartilage complex (TFCC) tears including some atypical that cannot be categorized under Palmer's classification. TFCC traumatic tears in 173 wrists were examined arthroscopically or macroscopically and divided into disk tears (subdivided into four types: slit tear, flap tear, horizontal tear and tear within the distal radioulnar joint) and peripheral tears (subdivided into six types: ulnocarpal ligament tear, dorsal tear, radial tear, ulnar styloid tear, foveal tear and distal radioulnar ligament tear). Combinations of these types were found in 32 wrists. Wrist arthroscopy revealed various traumatic TFCC tears that do not come under Palmer's classification; therefore establishment of a new classification for traumatic TFCC tears seems to be warranted.

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.

Diagnostic accuracy of magnetic resonance imaging and magnetic resonance arthrography for triangular fibrocartilaginous complex injury: a systematic review and meta-analysis

BACKGROUND

Triangular fibrocartilaginous complex (TFCC) tears are common sources of ulnar-sided wrist pain and resultant functional disability. Diagnosis is based on the history and clinical examination as well as radiographic evidence of a TFCC central perforation or a radial/ulnar tear. The purpose of this study was therefore to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) in the detection of TFCC injury in the adult population.

METHODS

Published and unpublished literature databases were searched. Two-by-two tables were constructed to calculate the sensitivity and specificity of MRI or MRA investigations against arthroscopic outcomes. Pooled sensitivity and specificity values and summary receiver operating characteristic curve evaluations were performed. The methodological quality of each study was assessed with use of the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) tool.

RESULTS

Twenty-one studies were included in the review, and these series included a total of 982 wrists. On meta-analysis, MRA was superior to MRI in the investigation of full-thickness TFCC tears, with a pooled sensitivity of 0.75 and a pooled specificity of 0.81 for MRI compared with 0.84 and 0.95, respectively, for MRA. MRA and MRI performed at greater field strengths were reported to have greater sensitivity and specificity than those performed at lower field strengths. There were insufficient data to assess the diagnostic test accuracy for partial-thickness TFCC tears.

CONCLUSIONS

Given its acceptable diagnostic test accuracy, it is recommended that MRA, rather than MRI, be performed in when there are questions about the diagnosis and subsequent management of patients with ulnar-sided wrist pain.

Predictors of distal radioulnar joint instability in distal radius fractures

PURPOSE

A tear of the triangular fibrocartilage complex (TFCC) is the most frequent soft tissue injury associated with fractures of the distal radius, and repair of the deep ligamentous portion of the TFCC is considered when the tear contributes to instability of the distal radioulnar joint (DRUJ). The purpose of this prospective cohort study was to identify predictors of DRUJ instability accompanying unstable distal radius fractures.

METHODS

Between 2002 and 2007, we prospectively treated 163 consecutive patients with unstable distal radius fractures with the volar locking plating system. Complete radioulnar ligament tears representing DRUJ instability were present in 11 of 163 distal radius fractures. We tested univariate associations between DRUJ instability and potential predictors and conducted multivariate analysis to establish independent predictors of instability. We applied receiver operating characteristics curves within the significant risk factors to determine threshold values.

RESULTS

In univariate analyses, only the radial and sagittal translation ratios of the fracture site were significant predictors of DRUJ instability. Multivariate logistic regression analysis confirmed that the radial translation ratio, which corresponds to a normalized DRUJ gap, was a significant risk factor. According to the receiver operating characteristics curve for the radial translation ratio, the area under the curve was 0.89. A cutoff value of 15% for the radial translation ratio showed the highest diagnostic accuracy rate.

CONCLUSIONS

A radiographic finding of a normalized DRUJ gap on posteroanterior views was the most important predictor to identify DRUJ instability accompanying unstable distal radius fractures. The relative risk of instability increases by 50% when the ratio of DRUJ widening increases by 1%.

ULNAR-SIDED WRIST PAIN DUE TO ISOLATED DISK TEAR OF TRIANGULAR FIBROCARTILAGE COMPLEX WITHIN THE DISTAL RADIOULNAR JOINT: TWO CASE REPORTS

Wrist arthroscopy has been successfully used with many modifications and improvements. However, distal radioulnar joint (DRUJ) arthroscopy is still uncommon. We experienced 2 cases of ulnar-sided wrist pain due to isolated triangular fibrocartilage complex (TFCC) disk tear within the DRUJ. DRUJ arthroscopy in these cases showed horizontal tear and fibrillation of TFCC disk without TFCC tear at the radiocarpal joint. Foveal attachment was intact in both cases. These were treated with debridement, which relieved pain after surgery and achieved good functional recovery. Although DRUJ arthroscopy is technically difficult, it is mandatory for making a diagnosis and treating ulnar-sided wrist pain.