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

[Diagnostics and classification of distal radius fractures]

Fractures of the distal radius show a wide spectrum of different fracture patterns. Although standard X‑ray images are sufficient for extra-articular fractures, the exact analysis of intra-articular fractures requires the use of computed tomography (CT) with coronal, sagittal and axial sectional images. The classification is based on the Working Group for Osteosynthesis Questions (AO) criteria. The treatment strategy can be more precisely defined by a CT-based classification. Special attention must be paid to the presence of the key corners, as they have a high risk for primary or secondary dislocation if they not adequately stabilized.

Standard radiographic assessments of distal radius fractures miss involvement of the distal radioulnar joint: a diagnostic study

INTRODUCTION

Distal radius fractures account for one-fifth of all fractures in the emergency department. Their classification based on standard radiographs is common practice although low inter-observer reliabilities and superiority of computer tomography (CT) scanning in evaluation of joint congruency have been reported.

MATERIALS AND METHODS

We retrospectively analyzed 96 displaced distal radius fractures scheduled for open reduction and internal fixation using standard radiographic assessment. The radiographs were classified with the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA), Fernandez and Frykman classifications by three observers and inter-rater reliabilities were calculated. Additional CT scanning was performed in all cases and the following parameters were assessed: radiocarpal joint involvement, fracture extent into the radial sigmoid notch, i.e. the distal radio-ulnar joint, comminution of the metaphysis, and concomitant ulnar styloid fracture. The CT scans were used as a reference standard to determine sensitivity and accuracy of standard radiographic assessment in evaluation of distal radius fractures.

RESULTS

The inter-rater agreement for the AO classification was 35.4%, 68.8% for the Fernandez and 38.5% for the Frykman classification. Fracture extension into the radiocarpal joint was present in 81 cases (84.4%). Sigmoid notch involvement was found in 81 fractures (84.4%). Involvement of both joints was present in 72 cases (75%). The sensitivity of standard radiographs regarding radiocarpal joint involvement was 93.8%. Considering involvement of the distal radio-ulnar joint the false-negative rate using standard radiographs was 61.7% and the test's accuracy for sigmoid notch involvement was 45.8%.

CONCLUSION

This study demonstrates that involvement of the sigmoid notch is frequently missed in standard radiographs. The presented data support the frequent use of CT imaging to allow the holistic illustration of a fracture's complexion and to ensure optimal pre-operative planning.

> 10-year outcome of dislocated radial fractures with concomitant intracarpal lesions as proven by MRI and CT

To clarify the role of concomitant carpal lesions in dislocated distal radius fractures (DRF), 104 consecutive patients with DRF underwent a preoperative morphological examination using CT and MRI. The study was performed between 2004 and 2006 with the aim of recording all types of concomitant carpal lesions as well as their consequences after 1 year. Carpal lesions of different types were found in all treated cases of dislocated DRF. A clinical follow-up 1 year (13.9 ± 6.5 months) after surgical treatment showed no correlation between the carpal lesions and the treatment outcome (previously described by Gologan et al. 2011). A second follow-up study ( > 10 years postoperative, range 11.2 ± 0.9 years) was initiated to find suspected later decompensations of the concomitant carpal lesions. A total of 37 of the original 104 patients could potentially be followed up: 22 patients had passed through both follow-ups and 15 could only be contacted with restrictions. 27 patients had died, 24 patients were excluded due to the presence of dementia or explicit rejection, and 16 patients could no longer be found. Using the Castaing score, the first follow-up after 1 year resulted in an average of 4.95 ± 3.1 points (range 0-12; "good result") and the second follow-up after 10 years in an average of 5.91 ± 2.9 points (range 2-14; "good result"). Again, there were no correlations with the primarily recognized carpal lesions [comparable groups 22 vs 22 (identical patients in both follow-ups); lost to follow-up rate 15.4%]. These results suggest that concomitant carpal lesions are primarily prevalent and detectable in (nearly) all dislocated DRF cases. However, with the usual protection of the wrist and the carpus after surgical treatment of DRF, these lesions often do not decompensate or require treatment, even after 10 years.

[Mediocarpal instability of the wrist]

Typical lesions of the carpal ligaments are mostly found after a fall on the wrist in hyperextension or as complex injuries after severe trauma, e. g. after a fall from a significant height, motorcycle accident or as accompanying lesions in multiple trauma. The typical mechanisms, patterns and diagnostic algorithms are well known for the common ligamentous injuries (e.g. scapholunate, lunotriquetral and perilunate); therefore, consistent diagnostic procedures and adequate therapy are increasingly performed after such lesions, e. g. by early ligament repair or by ligament reconstruction through augmentation. Within appropriate operative treatment, accompanying fractures are also treated and instabilities are addressed by transfixation of joints by Kirschner wires. If followed by immobilization with a cast or stable brace, healing can be achieved in most cases; however, more problems occur if ligamentous lesions or instabilities are not clearly due to a trauma mechanism and more the result of laxity or hypermobile situations due to a congenital predisposition. In such cases, wrist pain is often described and misdiagnosed as the result of overload or tenovaginitis.

1-Year outcome of concomitant intracarpal lesions in patients with dislocated distal radial fractures: a systematic assessment of 78 distal radial fractures

INTRODUCTION

Ligamentous lesions are concomitant to dislocated distal radius fractures in a high percentage. The purpose of this study was to evaluate the relevance of intracarpal lesions.

METHODS

Seventy eight of an original cohort of 104 distal radius fractures (74%) were studied over a follow-up period of one year after surgery with complete data (X-rays, CT, MRI, follow-up X-rays and questionnaire).

RESULTS

Most of our radius fractures (AO 23 type: A 39, B 9, C 30) present additional lesions: 97%. One-year evaluation showed an average Castaing score of 4.5 ± 2.5 points, means a "good" result of a scale of 0-27. Fifty five of seventy eight had an "excellent" or "good" result (<6 points). No patient had more than 12 points ("fair").

CONCLUSIONS

The dislocated distal radial fracture implies severe and complex injury to the whole wrist, mostly concerning intracarpal concomitant lesions (MRI). Surgical therapy of dislocated radius fractures followed by 6 weeks relief through thermoplastic splint seems to be sufficient to achieve good 1-year results. MRI-detectable carpal lesions at the time of the radial fracture are common, but only a few of them seem to decompensate later, give symptoms and became of therapeutic relevance.

[Detection of intrinsic ligament and TFCC lesions of the wrist. Direct versus indirect MRI arthrography]

BACKGROUND

The purpose of this study was to validate the diagnostic value of direct magnetic resonance imaging (dMRI) arthrography and indirect MRI (iMRI) arthrography concerning intrinsic ligament injuries and tears of the triangular fibrocartilage complex (TFCC).

PATIENTS AND METHODS

A randomized prospective trial was conducted with patients who presented with wrist pain potentially due to carpal lesions and 10 patients aged 19-60 years (3 female and 7 male) were included. Between the clinical examination and the diagnostic and therapeutic arthroscopy, dMRI and iMRI arthrography were performed for the diagnostics of injuries of the intrinsic ligaments or the TFCC. The results of dMRI and iMRI arthrography were evaluated by two radiologists blinded to the injuries of the patients and a consensus was reached. The results were compared with the findings obtained by arthroscopy.

RESULTS

In the arthroscopy five lesions of the scapholunate ligament (SL), one of the lunotriquetral ligament (LT) and seven of the TFCC were identified. The sensitivity of iMRI and dMRI for carpal ligament lesions (SL and LT) was low (50 %) whereas the specificity was high (93 %). For injuries of the TFCC the sensitivity (up to 100 %) and the specificity (100 %) were both excellent. The area under the curve (AUC) in the receiver operating characteristics (ROC) analysis was high for TFCC lesions in both dMRI and iMRI arthrography.

CONCLUSION

Indirect MRI arthrography is a suitable method for detection of injuries of the TFCC and intrinsic ligaments of the wrist with good sensitivity and specificity. Despite the low number of patients the results of this study showed that there were no essential differences between dMRI and iMRI arthrography with respect to the diagnostic value for carpal injuries of the wrist.

[Arthroscopy-assisted management of wrist fractures]

Distal radius fractures are the most common fractures in humans and early surgical intervention with modern plating systems is becoming increasingly more established to avoid secondary dislocation. Even fractures with slight dislocations are adequately stabilized and the affinity for surgical intervention and plating procedures is applied to secure these simple fractures. In this aspect the surgical indications are significantly dependent on X-ray examination results. Further diagnostics with respect to ligamentous and soft tissue injury are the exception although the impact energy which creates osseus fractures is sufficient by far to destroy functional soft tissue, cartilage and ligaments. The ongoing development of wrist arthroscopy enables new possibilities especially concerning concomitant articular involvement of distal radius fractures. Arthroscopy-assisted reduction and stabilization as well as minimally invasive soft tissue repair and loose body removal seem to be adequate methods to improve the surgical treatment of distal radius fractures.