Evidence
Alert

Plaster cast is as good as surgery for a broken scaphoid bone in the wrist, SWIFFT trial finds

Fractures of the scaphoid bone in the wrist are among the most common broken bone injuries. Traditionally, they have been healed by immobilising the wrist in a plaster cast but over the last two decades, surgeons have increasingly fixed the injury in surgery, by putting a small screw across the break.

However, before this study, there was little research into which method has the best outcome for patients and is most cost-effective.

The Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) compared the two ways of treating the break. It found that healing was similar with either approach but the surgical option was significantly more expensive.

What’s the issue?

The scaphoid is the small bone on the thumb side of the wrist. Breaks across its midpoint, or waist, account for most fractures.

A broken scaphoid bone is usually a straightforward injury. But if it is does not repair normally, arthritis may develop in the wrist. Young active men are the most likely to sustain this injury and could have arthritis in the wrist for the rest of their lives.

Immobilising the wrist in a plaster cast for 6-10 weeks is generally sufficient for full healing. But since the late 1980s, surgeons have increasingly operated to repair the break with a tiny headless screw. This surgery was carried out because doctors thought that, with a shorter time in plaster, patients could return to work and normal activities more quickly.

The outcomes from surgery versus plaster cast have never been comprehensively compared in terms of speed of healing, complications and pain for the patient, or cost effectiveness.

What’s new?

The SWIFFT study included 439 mostly male patients aged 32-39 years. Half (219) had surgery, and half (220) had a plaster cast put on their wrist.

The procedures were carried out by experienced surgeons and consultants across 31 NHS hospitals in England and Wales between July 2013 and July 2016.

The study concluded that cast immobilisation is as effective as surgical fixation. It found little difference in outcomes from both procedures:

  • after six months, and again at a year, there was no significant difference in pain, grip or wrist movement between the two groups
  • regardless of the approach taken, very few people had a break that did not heal
  • medical complications leading to stiffness or numbness were more common after surgery
  • after a year, the surgery group reported 15.6 days of lost employment, compared with 18.2 days in the plaster cast group.

The study also compared costs. It found the cost of surgery to the NHS was £2,350, compared to £727 for plaster cast treatment. The researchers concluded that a plaster cast should be used as first-line treatment. Surgery to fix the scaphoid with a screw should be carried out only if the fracture does not heal in a cast.

Why is this important?

The risks of surgery in relatively young and healthy men are low. Even so, the move to using plaster casts first would reduce risks further. It would also reduce the costs of treatment.

Researchers say their findings are timely, as there is an increasing trend towards surgery to fix a broken scaphoid bone in the wrist.

Many of those sustaining a wrist fracture were not aware of implications such as arthritis if the bone is not promptly and properly healed.

What’s next?

The study has had an immediate impact. Even during the SWIFFT trial, there was a shift back from surgery to simply treating with a plaster cast.

The findings are being incorporated into UK and Canadian guidelines for treating broken wrists. In the US, surgeons now may have to justify surgery rather than plaster cast.

Remaining questions include how the techniques compare in treating less common types of scaphoid fractures, or those with more displacement of the broken bones.

The current group of patients will be assessed five years after their initial treatment to look at longer term outcomes of arthritis and pain.

You may be interested to read

The full paper: Dias J, and others. Surgical fixation compared with cast immobilisation for adults with a bicortical fracture of the scaphoid waist: the SWIFFT RCT. Health Technol Assess 2020;24:1-270

An infographic depicting the SWIFFT study findings

Dy CJ, and others. An Epidemiologic Perspective on Scaphoid Fracture Treatment and Frequency of Nonunion Surgery in the USA. HSS Journal. 2018;14:245–50.

Li H, and others. Surgical versus nonsurgical treatment for scaphoid waist fracture with slight or no displacement: A meta-analysis and systematic review. Medicine. 2018;97:e13266

Garala K, and others. The epidemiology of fractures of the scaphoid. Bone Joint J. 2016;98:654–659

Funding

This study was funded by the NIHR Health Technology Assessment Programme.

Commentaries

Study author

With scaphoid waist wrist breaks, fixation with a screw was increasing across the UK, Europe and America. This study was important to compare surgery with plaster cast to identify what is best for the patient. From a function and pain point of view, there are no differences. Meanwhile, a health economic evaluation showed that fixing was much more expensive than treating in a cast.

The overall findings, which are being incorporated into the UK guidelines, were what we anticipated. Other studies have been very small, but this had more than 200 patients in each group and was well-placed to answer this question.

Joe Dias, Professor of Hand and Orthopaedic Surgery, University of Leicester and University Hospitals Leicester

Orthopaedic nurse

This study found the same outcomes in both groups long term; the small benefit seen in the surgery group at 6 weeks was not meaningful. These are important findings that suggest a move away from the surgical approach, an important consideration in these COVID challenging times where operating theatre resources and availability are more restricted.

Clare-Louise Sandell, Specialist Orthopaedic Nurse, Isle of Wight NHS Trust

Conflicts of Interest

Several authors have received funding from various pharmaceutical companies and charities.