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We present a case of revision Swanson wrist arthroplasty staged via a wrist fusion in a patient with rheumatoid arthritis. Due to extensive bone loss in the rheumatoid patient, it may not be possible initially to revise a wrist arthroplasty; however after fusion with a bone graft to regain bone stock we have demonstrated that this is possible. It may even be possible to convert such a fusion to a total wrist arthroplasty.

We report a case of a patient with rheumatoid arthritis undergoing revision surgery 30 years after primary metacarpophalangeal joint arthroplasty using a Swanson implant. Removal and replacement of the implant were successfully performed, and the patient was satisfied with the revision surgery.

The advantages of using multiple joint sparing antegrade intramedullary wiring for displaced, transverse and short oblique fractures of the small long bones of the hand has been well documented. This technique provides stable three-point fixation and permits early range of motion exercises to prevent hand stiffness. But in some revision cases where there is a breach or deficiency of subchondral bone due to previous intramedullary wiring or in old neglected juxta articular fractures of the metacarpal, proximal phalanx or middle phalanx with disuse osteopenia, there is a high chance of inadvertent joint penetration with intra medullary wiring, inspite of using blunt tipped bent K wires. This could happen intraoperatively or later in the follow up due to collapse of the fracture ends. We describe an innovative fixation technique which ensures stable fixation, no joint penetration and enables early range of motion to prevent hand stiffness.

Wrist arthroplasty is becoming more commonplace, with various implant choices available. The Motec (Swemac Orthopaedics AB, Linköping, Sweden) cementless ball-and-socket system is being increasingly utilised and is designed for the distal component to be implanted into the third metacarpal. However, distal component failure is a recognised complication. We outline our experience with the revision of this component into the second metacarpal. This technical note is presented through our experience of two patients who underwent revision arthroplasty for the management of peri-prosthetic fracture of the third metacarpal. This technique has demonstrated a safe and viable solution to this complication, achieving good anatomical centre of rotation, function, range of movement and patient satisfaction.

Level of Evidence: Level V (Therapeutic)

Background: Wrist arthroplasty is increasingly offered to patients with symptomatic wrist arthritis as an alternative to wrist arthrodesis. The purpose of this study was to present our outcomes with the ReMotion™ wrist arthroplasty in a consecutive series of patients with wrist arthritis from non-inflammatory conditions.

Methods: Thirteen (eight women, nine dominant wrists) patients, 68 (44–85) years of age with advanced radiocarpal arthritis due to SLAC/SNAC (11) and Kienbock disease (2) had a ReMotion™ (Stryker, Michigan, USA) wrist arthroplasty implanted, and were prospectively followed for 7 (4–9) years. The outcome measures included patient-rated wrist and hand evaluation (PRWHE) score, disabilities of the arm, shoulder and hand questionnaire (QuickDASH) score, visual analogue pain score (0–10) on the radial and ulnar aspect of the wrist at rest (VASrR/VASuR) and activity (VASrA/VASuA), active wrist range of motion (AROM) including flexion, extension, ulnar and radial deviation, pronation and supination and grip and key-pinch strength measured preoperatively and at yearly follow-ups by independent hand therapists.

Results: Six patients had ten re-operations during the follow-up including four revisions to a new arthroplasty. Four were considered loose at follow-up. A significant reduction in PRWHE (63 to 12), radial pain at activity (6 to 1) and increased pronation (85° v 90°) was observed.

Conclusions: We found a high complication and reoperation rate, two out of 13 had no complications or reoperations. The ReMotion™ arthroplasty should be used with caution in non-inflammatory wrist patients and the patients followed closely. A high reoperation and revision rate can be expected, and surgeons familiar with revision arthroplasty procedures should perform the surgery.

Level of Evidence: Level II (Therapeutic)

In this paper, we survey recent work on the use of abduction as a knowledge-based reasoning technique for analyzing software specifications. We present a general overview of logical abduction and describe two abductive reasoning techniques, developed from the logic and expert system communities. We then focus on two applications of abduction in software engineering, namely, analysis and revision of specifications. Specifically, we discuss and illustrate, with examples, how the above two abductive reasoning techniques can be deployed to reason about specifications, detect errors, such as logical inconsistencies, provide diagnostic information about these errors, and identify (possible) changes to revise incorrect specifications. We then conclude with a discussion of open research issues.

A symbolic calculus named as the R-calculus is built to revise the defects of axiomatic systems mechanically when some counterexamples are found. The R-calculus consists of the rules of logical connective symbols and logical quantifier symbols of first order languages. The concept of reachability, soundness and completeness of the R-calculus are introduced. The basic theorem of software testing based on the R-calculus is also introduced to help mechanizing model checking.