Die Arthroskopie des distalen Radioulnargelenks

Reduction Techniques in Volar Locking Plate Fixation of Distal Radius Fractures

Distal radius fractures are the most common upper extremity fracture and volar locking plate fixation has become a common modality for operative management of these injuries over the last 2 decades. However, despite the widespread use of volar locking plates, there remains no comprehensive guide detailing the available reduction techniques using these systems. This review aims to consolidate the reduction techniques from the literature along with the authors' experiences into a blueprint for distal radius fracture reduction when using a volar plate. Techniques described include those with and without use of the plate and with supplementary means of fixation for both extra-articular and intra-articular fracture patterns.

Complications after operatively treated distal radius fractures

In the recent years, treatment of distal radius fractures (DRF) has advanced considerably. Surgical fixation with palmar angular stable plate has gained popularity, due to a reported lower complication rate when compared to dorsal fixation. The type of trauma or injury, surgical procedure and impaired bone quality are all contributors to complications in DRF. The main aim of this review is to summarize the most common complications and possible therapeutic solutions. In addition, strategies for minimizing these complications will be discussed.

Arthroscopic assisted treatment of distal radius fractures and concomitant injuries

Wrist arthroscopy is mainly used to assist fracture reduction and fixation and to diagnose and treat concomitant injuries mainly to the scapholunate (SL), lunotriquetral (LT) ligament and the triangular fibrocartilage complex (TFCC). Arthroscopy is beneficial in improving anatomical reduction of fracture steps and gaps in intra-articular distal radius fractures (DRFs). Yet, the literature that the functional outcome correlates with the use of arthroscopy, is limited. Non-surgical treatment and immobilization is recommended for Geissler grade I-III Sl-ligament injuries, while open reduction, ligament suture and/or K-wire pinning is mandatory for complete ligament tears according to Geissler grade IV. This manuscript describes the current literature and gives insight into the authors' opinions and practice.

[Radiology of the distal radioulnar joint and the ulnocarpal complex]

X-ray images exposed in neutral position and radiocarpally centred are essential in imaging of the distal radioulnar joint (DRUJ). The anatomic orientation of the DRUJ is favourable for acquiring transaxial scans to display its anatomy, subtle derangements, osteoarthritis and intra-articular fractures free from superpositions. The triangular fibrocartilage complex (TFCC) is the most important stabilizer of the DRUJ. Provided that a focused clinical indication is given, high-resolution images are acquired, and an intra-venous or intra-articular contrast-agent is applied, all TFCC structures and destabilizing lesions can be displayed with the use of CT and MRI.

[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.

[Diagnosis and treatment of degenerative disc lesions of the wrist]

BACKGROUND

The triangular fibrocartilage complex (TFCC) widens the radiocarpal joint and takes part in load transmission from the carpus to the forearm. It is thereby prone to degenerative changes. The painful situation that can accompany degeneration is called ulnar impaction.

DIAGNOSIS

Clinical examination helps differentiate between various causes of ulnar-sided wrist pain. Standard X‑rays are needed to determine ulnar variance and stress radiographs can depict narrowing of the ulnocarpal joint space under load. MRI may prove degeneration of the TFCC itself or may indirectly confirm ulnar impaction in the presence of bone marrow edema in the ulnar head or at the proximal ulnar aspect of the lunate.

TREATMENT

If conservative treatment fails to alleviate symptoms, arthroscopy may be indicated. On the one hand, this completes the diagnostic cascade, and, on the other hand, allows decompression of the ulnocarpal joint space by resection of the TFCC with partial resection of the ulnar head (wafer resection). In the case of ongoing pain, ulnar shortening sufficiently alleviates ulnar-sided wrist pain. Thereby, modern standardized operation techniques are safe enough to ensure bone healing at the osteotomy site. The aim of alleviating ulnar-sided wrist pain is mostly achieved if the correct treatment option is chosen.

Treatment of Ulnar Impaction Syndrome with and without Central TFC Lesion

Background  Arthroscopic debridement of the triangular fibrocartilage (TFC) is well accepted in patients with ulnar impaction syndrome with central TFC lesions. Treatment remains controversial, however, when there is no such lesion from radiocarpal view. Purpose  This study assessed the clinical outcome of arthroscopic central TFC resection and debridement and secondary ulnar shortening in patients with ulnar impaction with central TFC lesion compared with patients without TFC lesion. Patients and Methods  Thirty-two consecutive patients with ulnar impaction syndrome were arthroscopically treated, 16 of whom had a central lesion of the TFC that was debrided. In the 16 patients with no lesion from the radiocarpal view, the TFC was centrally resected and debrided to decompress the ulnocarpal joint. Persisting symptoms necessitated ulnar shortening in four patients in each group. Two patients underwent repeat arthroscopic TFC debridement. All patients were examined at 3, 6, and 12 months, and at final follow-up (mean: 1.7 years) following arthroscopy, respectively ulnar shortening or hardware removal. Results  In both groups, pain, Krimmer, and DASH scores significantly improved. Improvements of DASH scores were significantly higher in patients without lesion at 12 months and at final follow-up. For other parameters, no significant difference was found between the two groups. Conclusion  In both situations, with and without central TFC lesion, resection and debridement sufficiently reduced the ulnar-sided wrist pain and improved function in three out of four patients, and therefore qualified as the first-line treatment of ulnar impaction syndrome as arthroscopy is performed, anyway. Those patients who complained of persisting or recurrent ulnar-sided wrist pain finally benefitted from ulnar shortening osteotomy as the secondary procedure. Level of Evidence  Therapeutic III, case-control study.

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.

Anatomical variability and histological structure of the ulnar nerve in the Guyon's canal

OBJECTIVES

The goal of our study was to analyze the prevalence of variations, branching patterns, and histology of the ulnar nerve (UN) in Guyon's canal to address its importance in hand surgery, particularly decompression of the UN.

METHODS

Fifty fresh cadavers were dissected bilaterally, and the nerve in the area of Guyon's canal was visualized. Samples for histology were also taken and prepared. The collected data were then analyzed.

RESULTS

Morphometric measurements of the hands and histological studies were not found to have significant differences when compared by left or right side or by sex. Three major branching patterns were found, with division into deep and superficial UN being the most common (85%). Additional findings included a majority (70%) presenting with a cutaneous branch within the canal and/or with an anastomosis of its distant branches with those of the median nerve (57%).

CONCLUSION

The UN is most commonly found to divide into a superficial and deep ulnar branch within Guyon's canal. However, additional branches and anastomoses are common and should be taken into careful consideration when approached during surgery in the area, particularly during decompression procedures of Guyon's canal.

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.