Study Finds Metal Pins No Better Than Plaster Cast For Broken Wrists

A new study has found that using metal K-wires, commonly known as “pins,” to hold broken carpal bones in place while they heal, is no better than a traditional cast cast.

The study was published in the journal BMJ.

Wrist fractures are common, especially in older women. If the bone fragments have dislodged (displaced from their normal position), they often require “manipulation” followed by either surgery to insert metal wires or plates, or a molded bandage as a nonsurgical alternative to hold the bones in position while they heal.

Surgery is costly and risky for the patient, while a molded cast is cheaper but may not provide the same functional outcome.

To find out which of these treatments is best, researchers tracked the progress of 500 adults with a displaced wrist fracture at 36 NHS hospitals between January 2017 and March 2019. Patients were randomly assigned to receive a cast (255) or surgical K-wire fixation (245) after manipulation of their fracture. Their average age was 60 and 417 (81 percent) were women. The primary (primary) outcome measure was the patient’s Wrist Evaluation (PRWE) at 12 months, which included questions about pain, function, and disability and gave an overall score from 0 (best) to 100 (worst).

Other (secondary) outcomes were PRWE scores at three and six months, quality of life, and complications, including the need for later surgery.

A total of 395 (79%) patients completed follow-up. While both groups improved over the 12-month period, there was no statistically significant difference in PRWE scores at three, six, or 12 months (mean score 21.2 in the cast group versus 20.7 in the with K-spoke). Health-related quality of life also showed a similar recovery pattern in both groups over time, and again the difference was not significant.

However, one in eight patients who received a cast required later surgery for loss of fracture position in the first six weeks after injury, compared with one patient in the K-wire group. Other complications were rare, with no evidence of difference between the two groups (28 in the cast group versus 22 in the K-wire group).

The researchers acknowledged some limitations, including the fact that neither the treating physicians nor the participants could be blind to the interventions. However, they say this was a large study involving adults of all ages, and the results are based on validated patient-reported outcomes, reflecting care provided in the healthcare system.