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

[Osteoarthritis of the wrist]

The term osteoarthritis (OA) of the wrist can be used as an umbrella term for various, often independent areas of OA, as the wrist is made up of several joints. Radiocarpal OA often occurs after untreated ligament injuries, incorrectly healed bone fractures in the carpus or after radius fractures involving the joint. A typical sequence of propagation is known for radiocarpal OA following scapholunate (SL) insufficiency or scaphoid pseudarthrosis. Other causes include inflammation, crystal deposits or bone necrosis. Ulnocarpal arthrosis occurs posttraumatically or primarily when there are differences in levels between the ulna and radius. When treating wrist arthrosis, after conservative measures have been exhausted a surgical procedure should be chosen that enables the best possible load-bearing and residual mobility, considering the surgical risks and individual requirements. During salvage operations, the defective cartilage areas are either fused directly or eliminated using appropriate diverting partial fusions and resection arthroplasty. An accurate analysis of the affected zones is crucial for selecting an appropriate intervention.

Long-term outcome after arthroscopic debridement of Palmer type 2C central degenerative lesions of the triangular fibrocartilage complex

PURPOSE

The purpose of this study was to report long-term objective and patient-reported outcome after arthroscopic debridement of central degenerative triangular fibrocartilage complex (TFCC) lesions.

METHODS

A total of 17 patients with central degenerative TFCC (Palmer type 2C) lesions and ulnar positive variance who were treated by arthroscopic debridement were retrospectively reviewed. Mean follow-up was 8.8 years. Assessment facilitating the Modified Mayo Wrist score (MMWS), the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH score), recording of pain level and of patient satisfaction, and radiological examination were done.

RESULTS

Patients reached a pain level of 1.7 VAS, MMW score of 92, and DASH score of 22. No significant differences could be detected between the operated and the contralateral extremity regarding range of motion and grip strength for all patients. No perioperative complications occurred.

CONCLUSION

Arthroscopic debridement of central degenerative TFCC lesions is safe, reliable, and efficacious even for ulnar positive variance.

LEVEL OF EVIDENCE

Therapeutic IV.

[The ulnocarpal complex : New clinical and radiological considerations]

CLINICAL ISSUE

The triangular fibrocartilage complex (TFCC) is an anatomically complex structure with high demands on spatial and contrast resolution in imaging.

RADIOLOGICAL METHODS

The central, predominantly avascular articular disc can be distinguished from the ligamentous, vascularized periphery. Imaging methods include magnetic resonance imaging (MRI, preferably contrast-enhanced) as well as MR and computed tomography (CT) arthrography.

DIAGNOSTIC INNOVATIONS

While high-resolution MRI represents the standard diagnostic tool for the TFCC in general, arthrographic imaging is particularly useful for assessment of the foveal (proximal) lamina of the TFCC. In radiological reporting, the convergence of the TFCC periphery towards the ulnar styloid process and the ulnar fovea must be considered.

ACHIEVEMENTS

The Palmer classification is suitable for evaluating lesions of the articular disc, whereas the Atzei classification is superior for lesions of the ulnar TFCC insertions.

PRACTICAL RECOMMENDATION

Use of a high-resolution examination technique and anatomy-based image interpretation are important for reliable MRI of the TFCC.

[Fractures of the carpal bones without the scaphoid bone]

With the exception of the relatively frequent fractures of the scaphoid bone, isolated fractures of individual carpal bones are rare. Because these injuries are uncommon and because of the complex anatomy and function of the carpus, treatment of carpal bone fractures can be challenging. Carpal bone fractures generally occur in young, sports active and professional patients, can be easily overlooked in plain radiographs and are frequently associated with ligamentous instability, neurovascular injuries and tendon lesions. Small posttraumatic alterations of the precisely aligned carpal structure can cause chronic pain and functional impairment. Therefore, if a wrist fracture is suspected a thorough clinical examination and appropriate differentiated imaging is always necessary, at the end of which a fracture can be excluded or an appropriate conservative or surgical treatment is initiated, with the aim of restoration of carpal anatomy and function.

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.

[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.

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.