Reproducibility of X-rays and CT arthrography in SLAC, SNAC, SCAC wrists

The Effect of Malunited Scaphoid Fractures on Joint Congruency

PURPOSE

Although the consequences of scaphoid nonunion have been well-established, the implications of malunions are not well-known. To date, malunions have mainly been studied with 2-dimensional imaging. The objective of this study was to employ 3-dimensional computed tomography (CT) imaging and inter-bone distance mapping to determine the implications of a scaphoid malunion on 3-dimensional joint surface area (JSA) (a measure of joint contact area) at an average of 7 ± 2 years (range, 4-12 years) after fracture.

METHODS

In 14 subjects with previous unilateral, malunited scaphoid fractures, we measured the 3-dimensional JSA using reconstructed CT bone models of the carpus. The JSA was compared within each individual, comparing images of the wrist collected at the time of fracture (baseline) and 7 years later (follow-up CT scans).

RESULTS

There was a significant increase in the measured JSA (reduced joint space) at the scaphotrapezial (23% increase) and scaphocapitate (13% increase) joints when the baseline and follow-up scans of the wrist were compared. An increased JSA indicates that the 2 opposing surfaces are closer in contact and have a reduced joint spacing reflective of degenerative changes. However, participants in this study showed no radiographic signs of degenerative changes in the wrists at midterm follow-up.

CONCLUSIONS

An increase in JSA was found in patients with a malunited scaphoid in the scaphotrapezial and scaphocapitate joints of the wrist an average of 7 years after injury, but these joint changes were not evident in measured radiographic signs of arthritis.

CLINICAL RELEVANCE

As early as 4 years after injury, the 3-dimensional JSA is significantly increased at the scaphocapitate and scaphotrapezial joints. Future work is needed to determine the implication of this increased in 3-dimensional JSA on the underlying subchondral bone, and to observe these patients for longer to determine whether degenerative changes develop.

SLAC and SNAC Wrist: The Top Five Things That General Radiologists Need to Know

Wrist osteoarthritis (OA) is a common painful condition that affects the patient’s quality of life by limiting the range of wrist motion and grip strength. Wrist OA often results from scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC). Early diagnosis of SLAC and SNAC is crucial because it affects treatment planning. Thus, radiologists should be able to interpret the early imaging findings. This pictorial review discusses the pathophysiology and the clinical symptoms of SLAC and SNAC and presents the imaging findings with emphasis on the proper imaging algorithm. Finally, it focuses on the treatment according to the degenerative status of each of these patterns.

Long-term radiological changes and functional outcomes after proximal row carpectomy: Retrospective study with 3 years' minimum follow-up

INTRODUCTION

The aim of this study was to analyze the radiological changes and determine the clinical and functional outcomes of proximal row carpectomy (PRC) over the long term.

HYPOTHESIS

Radiological changes after PRC occur in every patient while the clinical and functional outcomes remain stable over time.

METHODS

This was a retrospective single-center study of patients who underwent PRC between January 2004 and December 2014. A clinical assessment (range of motion, grip strength), functional assessment (Mayo Wrist score and QuickDASH) and radiographic assessment (radiocapitate osteoarthritis, radiocapitate congruency) was done in every patient at the longest follow-up.

RESULTS

Thirty-one patients were reviewed with a mean follow-up of 97.9 months. The indications for PRC were SLAC (n=10), SNAC (n=5), Kienböck disease (n=9) and other conditions (n=7). The radiocapitate index, which is the radius of curvature of the tip of the capitate divided by the mean radius of curvature of the lunate fossa, went from 0.68 immediately postoperative to 0.74 at the final assessment (p=0.035). The mean flexion/extension arc was 93°. The mean grip strength was 25 kg. The mean QuickDASH was 29 and the mean Mayo Wrist score was 69. Fifteen patients had radiocapitate osteoarthritis. Seven patients (22%) required revision surgery for wrist fusion after a mean of 18.6 months.

CONCLUSION

Radiological adaptation in the radiocapitate joint after PRC was found in this study. PRC is a reliable solution and yields stable outcomes over time for treating radiocarpal osteoarthritis, except in young adults and manual laborers who had a notable early revision rate.

LEVEL OF EVIDENCE

IV - retrospective study.

Clinical and radiological outcomes of 40 cases of SLAC and SNAC wrist treated by four-corner arthrodesis with locking plate

The treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist varies. No clear consensus exists on surgical indications. Scaphoid excision and four-corner arthrodesis with locking plate is one of preferred treatments for these lesions. The purpose of this study was to assess the clinical and radiological outcomes of locking plates for treating SNAC and SLAC wrist after a mean follow-up of 5 years and to compare these outcomes with the results reported in the literature. A retrospective study was conducted in two hospitals, involving 40 patients who underwent scaphoid excision and four-corner arthrodesis with locking plate between January 2006 and September 2016. All patients were reviewed as outpatients with clinical and radiographic measurements. At the last follow-up, the mean pain level on visual analog scale (VAS) was 2.5/10 [0-7] (SD: 1.7). Patients had a mean flexion of 46% and a mean extension of 46% compared to the contralateral side. An 18% gain was observed in grip strength. The mean postoperative QuickDASH score was 30 [0-57] (SD: 15.3). Seventy percent of patients were satisfied with the operation. Complete (all four joint interfaces) joint space fusion was achieved in 55% of patients. Only one patient (2.5%) had no joint fusion. The joint between the lunate and the capitate was fused in 38 patients (95%). Nine patients suffered complications; eight of them required surgical revision (20%). Four-corner arthrodesis with locking plate is a valuable surgical technique for treating SLAC and SNAC wrist because it preserve satisfactory range of motion and grip strength (64% compared to the non-operated side), maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis, as long as the technical challenges of this procedure are mastered.

Adaptive Proximal Scaphoid Implant (APSI): 10-year outcomes in patients with SNAC wrists

Radioscaphoid arthroplasty with the Adaptive Proximal Scaphoid Implant (APSI^®) is an attractive treatment alternative in the short and medium term for patients with early scaphoid non-union advanced collapse (SNAC) wrist. The purpose of our study was to determine the long-term outcomes of this implant in SNAC wrists. All patients who received the implant from October 2002 to October 2010 were included. A clinical and radiographic study was performed. Our case series included 39 patients, of which 33 were contacted, with a mean follow-up of 10 years (5.8-13.4). Most of the patients had stage-1 SNAC wrist (95%). There were nine complications (27%), seven of which required reoperation: implant dislocation (44%) or progression of the carpal degeneration (33%). Ninety-six percent of patients contacted were satisfied or very satisfied with their surgery (although 21% needed a second surgery) with a Mayo Wrist Score of 80/100 and a Patient-Rated Wrist Evaluation of 17.5/100. Wrist strength was 86% of the contralateral side. Flexion-extension range was 101° and pain assessed using a visual analog scale was at 1.2 (0-6). We report satisfactory and lasting results with the APSI^®, similar to those of scaphoid excision with four-corner fusion and proximal row carpectomy. Hence, the APSI^® is a reliable alternative for treating osteoarthritis in SNAC wrists.