Interdisciplinary consensus statements on imaging of DRUJ instability and TFCC injuries.

OBJECTIVES: The purpose of this agreement was to establish evidence-based consensus statements on imaging of distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) injuries by an expert group using the Delphi technique. METHODS: Nineteen hand surgeons developed a preliminary list of questions on DRUJ instability and TFCC injuries. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panelists consisted of twenty-seven musculoskeletal radiologists. The panelists scored their degree of agreement to each statement on an 11-item numeric scale. Scores of "0," "5," and "10" reflected complete disagreement, indeterminate agreement, and complete agreement, respectively. Group consensus was defined as a score of "8" or higher for 80% or more of the panelists. RESULTS: Three of fourteen statements achieved group consensus in the first Delphi round and ten statements achieved group consensus in the second Delphi round. The third and final Delphi round was limited to the one question that did not achieve group consensus in the previous rounds. CONCLUSIONS: Delphi-based agreements suggest that CT with static axial slices in neutral rotation, pronation, and supination is the most useful and accurate imaging technique for the work-up of DRUJ instability. MRI is the most valuable technique in the diagnosis of TFCC lesions. The main indication for MR arthrography and CT arthrography are Palmer 1B foveal lesions of the TFCC. CLINICAL RELEVANCE STATEMENT: MRI is the method of choice for assessing TFCC lesions, with higher accuracy for central than peripheral abnormalities. The main indication for MR arthrography is the evaluation of TFCC foveal insertion lesions and peripheral non-Palmer injuries. KEY POINTS: • Conventional radiography should be the initial imaging technique in the assessment of DRUJ instability. CT with static axial slices in neutral rotation, pronation, and supination is the most accurate method for evaluating DRUJ instability. • MRI is the most useful technique in diagnosing soft-tissue injuries causing DRUJ instability, especially TFCC lesions. • The main indications for MR arthrography and CT arthrography are foveal lesions of the TFCC.

Kienböck's disease in 2021.

The cause of Kienböck's disease is still unclear. It was initially considered as osteomalacia, before being recognized as avascular necrosis of the lunate. Its functional prognosis is doubtful, given that the progression often leads to wrist degeneration. Conservative treatment does not provide good results in adults; thus surgery is often needed. Certain anatomical factors such as the ulnar variance, configuration of the lunate or orientation of the radial glenoid have turned out not to contribute to necrosis but may contribute to lunate fracture. The lunate's vascularization can be precarious and mostly depends on the capsular arterioles. The lunate is a very mobile bone that participates in wrist movements, both in the radiocarpal joint and especially in the mid-carpal joints during activities of daily living. Radiographs are not the only diagnostic tools. The lunate makes contact with the radius and triangular fibrocartilage complex and is often subjected to high shear loads at the edge of the radius that can cause it to fracture. MRI and arthroscopy can contribute to the assessment. Kienböck's disease is likely an inflammatory, biological venous thrombosis disorder that leads to local damage due to intraosseous compartment syndrome. The basis of surgical treatment is to decompress the lunate to shield it from shear and compression loads. Existing osteotomy procedures will be described and compared to better understand their biomechanical effects. Some osteotomies do not reduce the loads transmitted to the lunate but can reduce the risk of intra-osseous shear. Some osteotomies may place excessive pressure on the lunate on its ulnar side. Some techniques are extra-articular and preserve the capsule's vascularization along with the anatomy of the mid-carpal joint. When the lunate damage is so severe that the bone's viability is compromised, bone grafting or replacement have been proposed. The palliative techniques typically used for wrist degeneration are indicated in the terminal stages. There are currently no effective biological treatments. While the origin of Kienböck's disease is still unknown, we now know that decompression osteotomies, while they do not heal the necrosis, protect the lunate from collapse, which hopefully provides enough time for biological healing to occur.

Volar Ganglion Cyst and Echo-Guided Assistance for the Arthroscopic Removal.

The ganglion of the wrist is very common but with uncertain prognosis. The arthroscopic resection seems to improve the result compared with open procedure, in decreasing recurrence and morbidity. Volar ganglions are close to the radial artery, the flexor pollicis longus tendon, and even the median nerve. Ultrasonography combined with arthroscopy offers incomparable safety for the resection of volar ganglions. The technical steps of this combined procedure are described, and the first published series are discussed.

Arthroscopically Assisted Eaton-Littler Trapeziometacarpal Ligamentoplasty.

Background Eaton-Littler ligamentoplasty has proven its efficacy in the treatment of trapeziometacarpal (TMC) instability. Description of Technique In this article, we describe the arthroscopically assisted Eaton-Littler ligamentoplasty through two clinical cases. Patients and Methods Arthroscopy is used to accurately place the metacarpal bone tunnel and pass the slip of flexor carpi radialis tendon in the latter. This procedure avoids soft-tissue dissection and could improve the outcome of this well-known surgery. Results The two clinical cases showed good short-term outcome with a decrease of pain and good function. Conclusions Arthroscopy to assist Eaton-Littler TMC ligamentoplasty is technically feasible, allowing a less invasive surgery. A larger prospective controlled study with a longer term outcome is mandatory to assess the real advantages of this modified procedure.

Evaluation of Kienböck's Disease Treated by Camembert Osteotomy at Seven Years.

In Kienböck's disease, radius shortening osteotomy is the most common treatment. The Camembert procedure is a wedge osteotomy that shortens only the radius facing the lunate. Its aim is to offload the lunate by redirecting the compression stress of the grip forces toward the scaphoid. The purpose of this study was to determine if the Camembert osteotomy is effective in improving clinical symptoms and limits lunate collapse. The series include 10 patients who underwent a Camembert osteotomy for Kienböck's disease between 2002 and 2012 (one bilaterally). They are six men and four women, aged 40.6 years. Five patients had an additional ulnar shortening osteotomy if ulnar variance was neutral or positive. The mean follow-up is 7 years. Preoperatively, range of motion, grip strength, pain, and functional scores were poor. All osteotomies healed within 3 months. Extension, ulnar deviation, grip, functional scores improved significantly. In 10 cases, there were improvement in the T1 and T2 signals on the magnetic resonance imaging (MRI). There was no lunate collapse. This series shows good results with no worsening of the lunate shape. There was no ulnocarpal impingement. The Camembert osteotomy proposes to offload the lunate and redirect strains toward the scaphoid. The supposed interest is to protect the lunate from collapse. In this small series, the Camembert osteotomy improved function in patients with early stage Kienböck's disease. MRI aspects improve in most cases and no patients collapsed. Camembert can be used in combination with a Sennwald's ulnar shortening when ulnar variance is neutral or positive. Authors propose this procedure for Lichtman's stages 1-2-3A if there are no cartilage or ligament lesions. This is a Level IV, case series study.

Treatment of the distal radius fractures with percutaneous pinning: evolution to the HK2 system.

Displaced fractures of the distal radius often require reduction and fixation to improve outcome in active patients. The volar locking plate gained ground over pinning, which was the first surgical solution described. But pinning methods have since evolved with fewer complications. The authors present a clinical study of distal radius fracture fixation using the HK2 technique, where subchondral pins are connected to intra-focal pins. The results are satisfactory with a lower complication rate compared to other pinning methods. This technical improvement relaunches the pinning technique, with its two advantages, being faster and significantly cheaper than locking plates, with similar long-term functional results.

Arthroscopic Classification of the Lesions of the Dorsal Capsulo-Scapholunate Septum (DCSS) of the Wrist.

The dorsal capsulo-scapholunate septum (DCSS) is an anatomic structure linking the scapholunate ligament and the dorsal capsule of the wrist. It should be a predynamic scapholunate stabilizer. The authors, using their experience for the extrinsic ligaments testing, suggest an arthroscopic testing of the DCSS. The status could be graded in 4 stages according to the trampoline aspect and to the fiber attachment. They report a preliminary study on a series of 53 arthroscopies made between January 2014 and December 2015 with evaluation of scapholunate ligament instability and DCSS laxity. There is a significant correlation between the lesional stage of the DCSS and the arthroscopic predynamic scapholunate instability stage (P<0.01).

The role of extrinsic ligaments in maintaining carpal stability - A prospective statistical analysis of 85 arthroscopic cases.

Several biomechanical studies have shown that the scapholunate (SL) and lunotriquetral (LT) ligaments are not the only stabilizers of the proximal carpal row. However, no study has yet analyzed the range of ligament lesions leading to instability in vivo. Arthroscopy has been used to assess the condition of the wrist's extrinsic ligaments by palpating and tensioning the various ligament and capsule structures. In this prospective study, this arthroscopic method was used in 85 cases of wrist sprain without static instability to evaluate the correlation between lesions of the intrinsic and extrinsic carpal ligaments and carpal instability. In SL instability, a scapholunate interosseous ligament (SLIL) lesion was statistically correlated with lesions of the long radiolunate ligament (P<0.05). There also was a statistically significant correlation between lesions of the SLIL and the radioscaphocapitate, scaphotrapezial and dorsal intercarpal ligaments. There was a correlation between the stage of SL instability and the number of lax extrinsic ligaments (P<0.05) but not with the severity of the extrinsic ligament lesions. In LT instability, a LT interosseous ligament lesion was statistically correlated with lesions of the dorsal intercarpal ligament (P<0.05). There also was a correlation between the stage of LT instability and the number (P<0.005) and severity (P<0.001) of the extrinsic ligament lesions. Arthroscopy can reveal hidden radiographic instability and can also be used to define the number and severity of injured ligaments. In carpal instability, a lesion of one intrinsic carpal ligament was associated with a lesion of one or more extrinsic ligaments.

A systematic method of arthroscopic testing of extrinsic carpal ligaments: implication in carpal stability.

Several biomechanical studies have shown that the scapholunate and lunotriquetral ligaments are not the only stabilizers of the proximal carpal row. However, no study has yet analyzed the spectrum of ligamentous lesions in vivo, leading to instability. We describe an arthroscopic technique for evaluating the extrinsic carpal ligaments. The testing relies on visualization and palpation of different ligaments. Their integrity is assessed with a 4-stage scale. Radiocarpal arthroscopy enables assessment of the following ligaments: the radiocarpal part of the radio-scapho-capitate, the long radiolunate, the short radiolunate, the ulnolunate, the ulnotriquetral, and the dorsal radiocarpal. Midcarpal arthroscopy enables assessment of the mid part of the radio-scapho-capitate, the triquetrocapitate, the scaphotrapezial, and the dorsal intercarpal. Above assessment is proposed in addition to assessing the articular cartilage, scapholunate, and lunotriquetral ligaments. This method allows a precise arthroscopic assessment of the extrinsic ligaments of the wrist. It could give an important help in the understanding of carpal instability.

Anatomical Description of the Dorsal Capsulo-Scapholunate Septum (DCSS)-Arthroscopic Staging of Scapholunate Instability after DCSS Sectioning.

Background The dorsal capsuloligamentous scapholunate septum (DCSS) is a confluence of the dorsal capsule, the dorsal intercarpal ligament (DIC), and the scapholunate interosseous ligament (SLIOL). It appears to play a role in the stability of the scapholunate articulation. The purpose of this study was to describe the anatomical basis for this structure and to investigate its role in scapholunate instability through sectioning of this structure followed by an arthroscopic and fluoroscopic analysis. Material and Methods In the anatomical part of the study we dissected 3 fresh cadaver wrists to examine the anatomy of the DCSS. In the arthroscopic part of the study we assessed the EWAS grade of SL instability before and after sectioning the DCSS and measured the scapholunate and radiolunate angles fluoroscopically. Results Sectioning the DCSS increased the EWAS grade of SL instability but did not affect the scapholunate gap, the scapholunate angle or radiolunate angle. Conclusion We have demonstrated that there is a distinct structure that is separate from the dorsal capsule, which we have labeled the Dorsal Capsuloligamentous Scapholunate Septum. We believe that the DCSS is a previously unreported secondary stabilizer of the SL joint which may have therapeutic and prognostic implications.

Surgical technique of a radial wedge "camembert" osteotomy in Kienböck disease.

The main accepted principle to treat Kienböck disease is to decompress the lunate. Radius shortening is the most used technique. Three transverse osteotomies of the radius are described: neutral shortening osteotomy, lateral closing wedge osteotomy, and medial closing wedge osteotomy. Shortening the radius decompress the lunate and more or less the scaphoid. This deviates axial constraints toward ulna and triangular fibrocartilage complex. But the ulnar wrist is not able to support important axial constraints. The authors propose a solution to decompress only the lunate and not the scaphoid. This solution deviates axial constraints toward the scaphoid, which is naturally the most capable bone to support it. The authors describe a new radial nontransverse decompression wedge osteotomy. It allows to shorten the radius in front of the lunate. The fixation is done with a dorsal staple. To complete lunate decompression, authors propose to associate a metaphysal ulnar oblique shortening, essentially if ulnar variance is neutral or positive. The preliminar results on 10 cases are presented.

An objective method to measure cell survival by computer-assisted image processing of numeric images of Petri dishes.

This work establishes an objective method to measure cell clonogenic survival by computer-assisted image processing using images of cell cultures fixed and stained in Petri dishes. The procedure, developed by Samba Technologies, consists of acquiring Petri dish pictures with a desktop scanner and analysing them by computer, using algorithms based on the 'top hat' filter. The results from the automated count for the cell line SQ20B are compared with those found by two observers, before and after normalization of the counting. After normalization, the shape of the survival curves of the 'manual' counting of the Petri dishes shows a good correlation between both observers. The software enables the small visible differences in count between observers to be eliminated. The comparison between the absolute number of colonies shows an increased difference between the two manual scorings that can be as great as 67 colonies, whereas the difference between the two automated counts is never greater than 8 colonies. These results demonstrate that the 'manual' count is inter- and intraobserver variable, whereas the automatic count performs reproducible cell colony counts, thereby minimizing user-generated bias. The large amount of data produced also gives information about cell and colony characteristics. Thus, this computer-assisted method has considerably improved the reliability of our statistical results.

Overexpression of the mouse Fas gene in human Hep3B hepatoma cells overcomes their resistance to Fas-mediated apoptosis.

BACKGROUND/AIMS: Fas-induced apoptosis is one of the main forms of apoptosis occurring in hepatocytes. We have previously demonstrated that the human hepatoma cell line Hep3B is resistant to Fas-mediated apoptosis. In this study, we investigated whether the human Fas receptor itself, or the Fas transduction pathway was responsible for the resistant phenotype. METHODS: Clones of Hep3B cells overexpressing the mouse Fas gene (Hep3B(mfas)) were generated by transfection, and apoptosis was studied by (i) chromatin condensation and nuclear fragmentation, (ii) flow cytometry, (iii) DNA fragmentation and (iv) poly (ADP-ribose) polymerase cleavage. RESULTS: Use of the species-specific and agonistic anti-mFas monoclonal antibody (JO2), showed that the mFas receptor was correctly routed to the plasma membrane of Hep3B(mfas) cells. Using the four above-mentioned criteria, we demonstrated that JO2 triggered mFas-mediated apoptosis of Hep3B(mfas), but not of Hep3B(pCi) cells (transfected with an empty vector). CONCLUSIONS: Our data show (i) that the Fas signaling pathway can be completed when a functional mFas receptor is expressed in Hep3B cells, and thus, (ii) that the death-inducing signaling complex components and the effector caspases are functional in Hep3B cells. Moreover, they suggest that the Fas subunits are not pre-assembled at the cell membrane before receptor-ligand interaction.