Klinische Untersuchung des distalen Radioulnargelenks

Advancements in Diagnosis and Management of Distal Radioulnar Joint Instability: A Comprehensive Review Including a New Classification for DRUJ Injuries

Distal radioulnar joint (DRUJ) instability is a complex condition that can severely affect forearm function, causing pain, limited range of motion, and reduced strength. This review aims to consolidate current knowledge on the diagnosis and management of DRUJ instability, emphasizing a new classification system that we propose. The review synthesizes anatomical and biomechanical factors essential for DRUJ stability, focusing on the interrelationship between the bones and surrounding soft tissues. Our methodology involved a thorough examination of recent studies, incorporating clinical assessments and advanced imaging techniques such as MRI, ultrasound, and dynamic CT. This approach allowed us to develop a classification system that categorizes DRUJ injuries into three distinct grades. This system is intended to be practical for both clinical and radiological evaluations, offering clear guidance for treatment based on injury severity. The review discusses a range of treatment options, from conservative measures like splinting and physiotherapy to surgical procedures, including arthroscopy and DRUJ arthroplasty. The proposed classification system enhances the accuracy of diagnosis and supports more effective decision making in clinical practice. In summary, our findings suggest that the integration of advanced imaging techniques with minimally invasive surgical interventions can lead to better outcomes for patients. This review serves as a valuable resource for clinicians, providing a structured approach to managing DRUJ instability and improving patient care through the implementation of our new classification system.

Modified Kapandji technique in pediatric displaced distal radius fractures: results in 195 patients

PURPOSE

The modified Kapandji technique has been proposed for fracture reduction in pediatric displaced distal radius fractures (DDRFs), but evidence is sparse. The purpose of this study was to evaluate our outcomes and complications, critically and systematically, when performing the modified Kapandji technique in pediatric DDRFs. Using this technique since 2011, we asked: (1) What is the quality of fracture reduction using this technique? (2) How stable is fracture alignment with this technique? (3) What are the postoperative complications and complication rates?

METHODS

Retrospective observational study of 195 pediatric patients treated with the modified Kapandji technique. Quality of fracture reduction, fixation type (intrafocal, combined, or extrafocal), and coronal/sagittal angulation were recorded at surgery and healing. Perioperative complications were graded. Patients were stratified by fracture (metaphyseal or Salter-Harris) and fixation type, as well as age (≤ 6 years; 6 to 10 years; > 10 years).

RESULTS

Fracture reduction was 'good' to 'anatomical' in 85% of patients. 'Anatomical' fracture reduction was less frequent in metaphyseal fractures (21% vs. 51%; p < .001). Mean angulation change was higher in metaphyseal fractures in both the sagittal (p = .011) and coronal (p = .021) planes. Metaphyseal fractures showed a higher mean change in sagittal angulation during fracture healing for the 'intrafocal' group. We observed a 15% overall complication rate with 1% being modified Sink Grade 3.

CONCLUSION

The modified Kapandji technique for pediatric DDRFs is a safe and effective treatment option. Metaphyseal fractures that do not involve the physis should be treated with extrafocal or combined wire fixation. Complications that require additional surgical treatment are rare.

LEVEL OF EVIDENCE

Level of evidence IV.

Indications, surgical approach, reduction, and stabilization techniques of distal radius fractures

Distal Radius fractures (DRF) are one of the most common injuries in the upper extremity and incidence is expected to rise due to a growing elderly population. The complex decision to treat patients operatively or conservatively depends on a large variety of parameters which have to be considered. No unanimous consensus has been reached yet, which operative approach and fixation technique would produce the best postoperative functional results with lowest complication rates. This article addresses the available evidence for indications, approaches, reduction, and fixation techniques in treating DRF.

Salvage procedure after malunited distal radius fractures and management of pain and stiffness

Indications for surgical treatment of distal radius fractures (DRF) remain controversial in the literature, especially in elderly patients. Complication rates after operatively treated DRF are low and well documented. These include malunion, degenerative osteoarthritis in the radiocarpal joint and subsequently pain and impaired hand function. If conservative treatment fails then salvage procedures are necessary. This review summarizes the therapeutic options available to treat degenerative osteoarthritis after malunited distal radius fractures, regardless of the initial operative or conservative treatment.

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.

Rehabilitation after distal radius fractures: is there a need for immobilization and physiotherapy?

Although the literature generally agrees that displaced distal radius fractures require surgery, no single consensus exists concerning the length of immobilization and type of post-operative physiotherapeutic rehabilitation program. Palmar locking plate fixation represents a very stable fixation of the distal radius, and was assessed biomechanically in various studies. Surprisingly, most authors report additional immobilization after plate fixation. One reason might be due to the pain caused during active wrist mobilization in the early post-operative stages or secondly to protect the osteosynthesis in the early healing stages preventing secondary loss of reduction. This article addresses the biomechanical principles, current available evidence for early mobilization/immobilization and impact of physiotherapy after operatively treated distal radius fractures.

Biomechanical considerations on a CT-based treatment-oriented classification in radius fractures

A wide range of different classifications exist for distal radius fractures (DRF). Most of them are based on plane X-rays and do not give us any information on how to treat these fractures. A biomechanical understanding of the mechanical forces underlying each fracture type is important to treat each injury specifically and ensure the optimal choice for stabilization. The main cause of DRFs are forces acting on the carpus and the radius as well as the position of the wrist in relation to the radius. Reconstructing the mechanism of the injury gives insight into which structures are involved, such as ruptured ligaments, bone fragments as well as the dislocated osteoligamentous units. This article attempts to define certain key fragments, which seem crucial to reduce and stabilize each type of DRF. Once the definition is established, an ideal implant can be selected to sufficiently maintain reduction of these key fragments. Additionally, the perfect approach is selected. By applying the following principles, the surgeon may be assisted in choosing the ideal form of treatment approach and implant selection.

Ulnar shortening osteotomy as a treatment of symptomatic ulnar impaction syndrome after malunited distal radius fractures

A malunited distal radius fracture can lead to symptomatic ulnar impaction syndrome, which is a common cause for ulnar-sided wrist pain. If conservative treatment fails and symptoms persist after an arthroscopic ulnocarpal debridement, ulnar shortening osteotomy (USO) is the treatment of choice. Since the first USO described by Milch in 1941 after a malunited Colles fracture, many techniques have been described varying in surgical approach, type of osteotomy and osteosynthesis material used. Many studies demonstrated good to very good functional results after USO, reporting, however, a delayed union or non-union rate up to 18%. A modern, low profile, locking plate showed in our short-term study very good functional results and no implant-associated complications, in particular no non-union.

[Palmar radioscapholunate arthrodesis with distal scaphoidectomy]

OBJECTIVE

Radioscapholunate (RSL) arthrodesis with distal scaphoidectomy using an angular stable plate and palmar access in post-traumatic or degenerative osteoarthritis limited to the radiocarpal joint.

INDICATIONS

Osteoarthritis limited to the radiocarpal joint with intact mediocarpal joint after malunited intra-articular distal radius fractures, rheumatoid osteoarthritis, scapholunate advanced collapse (SLAC) up to stage II.

CONTRAINDICATIONS

Mediocarpal osteoarthritis, poor patient compliance, SLAC from stage III, osteitis.

SURGICAL TECHNIQUE

The palmar RSL arthrodesis is performed using the palmar approach between the flexor carpi radialis tendon and the radial artery. After releasing the pronator quadratus muscle, a longitudinal capsulotomy is performed and the radiocarpal joint is inspected. After correction of a volar or dorsal intercalated segmental instability of the lunate, the lunate is temporarily fixed to the scaphoid using a K-wire. The distal quarter of the scaphoid and the palmar rim of the distal radius is resected and the cartilage between the scaphoid, lunate and distal radius is removed. The scaphoid and lunate are temporarily fixed to the distal radius using K‑wires. Under image intensifier control the angular stable low-profile plate (e.g., volar 2.5 Trilock RSL Fusion plate [Medartis® Aptus® Basel, Switzerland]) is fixed to the distal radius in the long-leg hole. The scaphoid and lunate are fixed distally with two screws each. The carpus is pushed distally using a Codeman distractor and the cancellous bone graft is impacted. Finally, the shaft is fixed with angular stable screws.

POSTOPERATIVE MANAGEMENT

Immobilization using a plaster cast or thermoplastic short-arm orthosis for 5 weeks. After 2 weeks, the orthosis can be removed during hand therapy with active wrist and finger exercises. Normal activities permitted after 12 weeks.

RESULTS

Palmar RSL arthrodesis and distal scaphoidectomy using angular stable plate fixation shows a high union rate and pain relief while maintaining good residual mobility of the wrist.

Evaluation of radiological instability signs in the distal radioulnar joint in children and adolescents with arthroscopically-verified TFCC tears

INTRODUCTION

Recent reports in the adult literature reported the use of standardized radiographic measurement techniques to determine distal radioulnar joint (DRUJ) instability. The aim of this study was to evaluate the efficacy and accuracy of (1) the MRI-based modified radioulnar ratio technique and (2) the pisoscaphoid (PiSca) and radioulnar (RaUl) distances in true lateral radiographs in children and adolescents with arthroscopically-verified TFCC tears.

MATERIALS AND METHODS

We retrospectively assessed lateral wrist radiographs and axial MRI sequences of 18 adolescent patients (22 wrists) who had arthroscopically-confirmed TFCC tears and compared them to similar imaging of a control group of 28 healthy patients (28 wrists). Three raters assessed the images twice in a 2-week interval. Intraclass correlation coefficients (ICCs), unifactorial ANOVA, and ROC analysis were performed with regards to the different radiographic variables.

RESULTS

The interrater ICCs were almost perfect for all measurements except RaUl1, which showed a substantial agreement (0.751) among the three observers. The intrarater ICCs were almost perfect when measuring PiSca and MRI, and substantial to almost perfect for RaUl. Pearson's correlation showed a moderate, positive correlation between PiSca and RaUl distances (r = 0.608; p < 0.001), and a moderate, negative correlation between RaUl distance and MRI shift (r = - 0.486; p = 0.010). When the three core groups (peripheral, central tear, controls) were compared to each other regarding the radiographic instability parameters, only the MRI shift revealed a statistically significant difference (p = 0.003). Comparisons revealed significant differences between patients and controls (p = 0.004) and peripheral tears vs. controls (p = 0.001 and p = 0.010). The ROC analysis revealed a significant AUC only for the MRI (AuC 0.787 and p = 0.002).

CONCLUSIONS

Children and adolescents with peripheral TFCC tears showed significantly increased instability parameters in MRI compared to controls. These measurement techniques are no replacement for a thorough clinical examination but may be helpful for indicating diagnostic wrist arthroscopy in ambiguous cases.

LEVEL OF EVIDENCE

Level III; Diagnostic.

[Reconstruction of the deep fibers of the distal radioulnar ligaments facilitating a tendon graft-Adams' procedure]

GOAL

Anatomical reconstruction of the deep fibers of the distal radioulnar ligaments to stabilise the distal radioulnar joint.

INDICATIONS

Multidirectional instability of the distal radioulnar joint without the possibility for anatomic refixation of the distal radioulnar ligaments.

CONTRAINDICATIONS

General operative contraindications, infection, insufficient soft tissue coverage, osteoarthritis of the distal radioulnar joint, excessive ulna impaction syndrome, osseous deformation.

SURGICAL TECHNIQUE

Dorsal approach to the distal radioulnar joint, preparation of the ulna head, transosseous transfer of tendon graft through the distal ulnar corner of the radius at the sigmoid notch, transfer through the ulnar fovea and transosseous fixation within the ulna head using an interference screw.

POSTOPERATIVE MANAGEMENT

Long arm cast for 4-6 weeks, then Bowers splint for further 4 weeks; optional long arm orthosis without limiting elbow flexion and extension for 4-6 weeks, then Bowers splint for further 4 weeks; starting exercises after 12 weeks.

RESULTS

Reconstruction of the distal radioulnar ligaments using tendon grafts stabilises the distal radioulnar joint with restoration of joint kinematics.

Three-dimensional kinematics of the flexor pollicis longus tendon in relation to the position of the FPL plate and distal radius width

INTRODUCTION

The standard therapy of intra-articular and extra-articular distal radius fractures consists of open reduction and stabilization using palmar osteosynthesis with an angularly stable plate. The integrity of the flexor pollicis longus tendon (FPLT) may be mechanically affected by the plate, with rupture rates between 1 and 12% reported in the literature, occurring during a postoperative time period from 4 to 120 months. The aim of this study was to investigate the position of the tendon in relation to the distal edge of the plate using high-resolution ultrasonic imaging.

MATERIALS AND METHODS

Nineteen patients undergoing osteosynthesis for distal radius fracture in 2015 with the Medartis^® APTUS^® FPL plate were included in this study. Of these, seven dropped out for various reasons. Therefore,  twelve patients with a median age of 52 years (range 24-82 years) were included in the final analysis. High-frequency ultrasound was performed within a median of 28 (range 10-52) weeks by an experienced radiology specialist to locate the FPLT position in two separate wrist positions: (1) wrist held in 0° position and fingers extended and (2) wrist held in 45° of dorsal extension and actively flexed fingers II to V (functional position). For analysis, we used the axial ultrasound videos. Postoperative X-rays and CT scans were included for the analysis, especially the soft-tissue CT scan window for the exact localization of the FPLT.  Dynamic ultrasound scanning was used to localize the FPLT in relation to the plate in 0° and functional position of the hand. Using CT scanning, the position of the plate relative to the bone was determined. In this way, we were able to correlate the functional FPLT position with the osseous structures of the distal radius.

RESULTS

In all cases, the FPLT was positioned closer to the volar distal edge of the FPL plate in functional position than in 0° position. In four cases, the FPLT did not touch the plate at all and was shown to shift diagonally from radio-volar in ulno-dorsal direction during wrist movement from 0° to functional position, similarly to the sliding of the tendon in the assumed physiological motion sequence. In these cases, in the functional position the center of the FPLT was positioned slightly ulnarly of the center of the distal radius (i.e., less than 50% of the distal radius width measured from the radial border of DRUJ), and positioned more ulnarly than in all other cases (i.e., in which the FPLT came into contact with the plate). In the remaining two-thirds of the cases (eight patients), the FPLT touched the plate during wrist movement from 0° to functional position, shifted in dorsal direction and slid into the plate indentation, irrespective of whether the tendon entered the indentation from the radial or the ulnar side, and independent of the ulnoradial position of the plate. No signs of tendinopathy of the FPLT were found in any of the cases.

CONCLUSION

The results show that the indentation of the Medartis^® APTUS^® FPL plate reduces the tendon-plate contact and ideally even prevents it entirely. In particular, ulnar positioning of the plate lowers the risk of tendon-plate contact. If the FPLT touches the plate, the tendon pulls into the plate indentation, thus lowering the contact. Consequently, the Soong criteria are not applicable when a FPL plate is used.

Mid-term outcome (11-90 months) of the extensor retinaculum flap procedure for extensor carpi ulnaris tendon instability

INTRODUCTION

The aim of our study was the assessment of the mid-term outcome of patients treated with a pediculated extensor retinaculum flap for extensor carpi ulnaris (ECU) tendon subluxation including postoperative tendon stability control.

MATERIALS AND METHODS

Twelve patients treated with an extensor retinaculum flap for symptomatic ECU tendon instability were retrospectively evaluated. Follow-up examinations included functional and radiologic assessment. The range of motion, grip strength, DASH score, PRWE score, Krimmer score and subjective satisfaction were recorded. A rotation-movie MRI was conducted before and after surgery to visualize tendon displacement.

RESULTS

Wrist extension was 65.8° (SD 10.0°), flexion 64.2° (SD 12.2°), radial deviation 15.8° (SD 6.0°), ulnar deviation 32.1° (SD 7.2°), pronation 82.5° (SD 9.4°) and supination 85.0° (SD 9.0°). Mean grip strength was 30.5 kg (SD 8.9 kg). Six patients presented an excellent, four a good, one a fair and one a poor result on the Krimmer score. The DASH and PRWE scores showed a mean of 24.2 (SD 25.1) and 32.2 (SD 29.4) points. MRI showed a dislocation (n = 7) or subluxation (n = 5) of the ECU tendon preoperatively. Five patients showed an unchanged displacement pattern postoperatively.

CONCLUSION

The pediculated extensor retinaculum flap as a treatment for a symptomatic ECU instability shows good to excellent results and a high subjective satisfaction independent of postoperative ECU tendon displacement.

Early complications and radiological outcome after distal radius fractures stabilized by volar angular stable locking plate

INTRODUCTION

Distal radius fractures (DRF) are the most common fractures of the upper extremities. The incidence is expected to continue rising in the next years due to the increased life expectancy. Palmar locking plate stabilizing has since become the standard treatment for dorsally displaced DRF with a complication rate of 8-39% reported in the literature. Main aim of this study was to investigate the incidence of complications after DRF stabilization using palmar angular stable locking plate.

METHODS

A retrospective medical records review conducted from January 2013 to December 2016 included a total of 392 patients with DRF, that were stabilized using palmar angular stable locking plate and showed a minimum follow-up of 3 months. The group comprised 259 female and 133 male patients with a mean follow-up interval of 11 months (range 3-52 months). All recorded complications were documented. Range of motion (ROM) in extension, flexion, supination, pronation, radial- and ulnar deviation of the last follow-up was noted. Age was divided into younger than 65 years (< 65 years) and older than 65 years (≥ 65 years). The primary, immediate postoperative and final checkup radiographs were scrutinized for alignment and intra-articular step-off.

RESULTS

A total of 51 (13%) early and 17 late (4%) complications were recorded in 392 patients. The most common complications included carpal tunnel syndrome (3%), complex regional pain syndrome (3%) and loss of reduction (2%). Of the 68 complications, only 25 (6%) were directly related to the plate. 73% of all complications occurred in AO type C fractures. Patients without complications showed a significantly better ROM in extension, flexion, pronation and supination than patients with complications. No significant differences in incidence of complications, ROM or loss of reduction could be found between patients over and under 65 years of age. Gender and type of immobilization showed no significant influence on the complication rate.

CONCLUSIONS

Stabilization of DRF by palmar angular stable locking plate is a safe form of treatment. In the majority of the cases a good clinical and radiological outcome with no complications was documented. Gender and type of immobilization had no impact on the complication rate and an age over 65 years is not associated with an increased risk for complications or restricted ROM.