Through the skin pinning for treating wrist fractures in adults

Background

Broken wrists are fractures at the lower end of the radius, one of the two forearm bones. Typically in older people, these can occur when people put out a hand to break a fall. The broken bones are often pushed apart, resulting in a 'displaced' fracture.

For most broken wrists, the bones can be moved back together (reduced) and held in place without an operation by a plaster cast for a few weeks. When fractures are unstable, the parts do not stay together. Another way of managing broken wrists is to hold the bones back in place with a surgical procedure, such as percutaneous pinning. This involves the insertion of pins or wires through the skin (percutaneous) to hold the bones in a proper position while they heal. In most pinning methods, pins or wires are used to fix the fragments together. In Kapandji pinning, the wires are placed to support the distal (lower end) fragment.

Methods

This is an update of a Cochrane review first published in 2007. We looked at the evidence from randomised controlled trials testing the use of percutaneous pinning or comparing aspects of pinning. Beforehand, we set out the main outcomes: patient-reported function, numbers of participants with any complication and with complications requiring further treatment, grip strength and health-related quality of life. We searched medical databases up to June 2019.

Results of the search

We included 26 randomised studies involving 1946 generally older and female adults with potentially unstable wrist fractures. The studies tested one of 10 comparisons and overall under-reported outcomes. Below, we report only the main outcomes for which evidence was available.

Key results

Eleven trials compared percutaneous pinning with plaster cast immobilisation. We are uncertain whether pinning makes a difference to patient-reported function at six weeks or six months (data from one study). There were no data on the numbers of participants who had any complication. Redisplacement of the fracture resulting in further treatment occurred on average in one of eight people who had cast alone (six studies). Of the surgery-related complications, infection requiring antibiotics and sometimes early wire removal occurred on average in one of 13 people in the pinning group (seven studies). We are uncertain whether there is a difference between the two treatments in the risk of other complications. We are uncertain of the effects of pinning on grip strength at 12 months (four trials) or quality of life at four months (one study).

Of the six studies comparing different techniques of pinning, one compared Kapandji pinning with an across-fracture method. We are uncertain whether Kapandji pinning increases the risk of complications and of the finding of little between-group difference in grip strength.

Two studies compared biodegradable (dissolvable) pins versus metal wires, using two very different pinning techniques. Both found an excess of complications associated with the use of biodegradable material.

Three studies compared burying the wire ends under the skin with leaving them exposed. We are uncertain whether burying wires reduces the risk of superficial infection. However, burying of wires may require more invasive treatment for removal.

Usually, the wrist is placed in a cast after pinning. We are uncertain whether the position of the wrist in the cast makes a difference to the risk of complications or grip strength (one study). Three studies compared early mobilisation after one week with four or six weeks of cast immobilisation. One study using Kapandji pinning reported more complications for early mobilisation but we are uncertain of the effect of early mobilisation on overall complications or grip strength.

No trials tested different methods or timing of pin removal.

Quality of the evidence

All 26 studies had weaknesses that could affect the reliability of their results. We considered that the evidence for all reported outcomes and for all comparisons was low or, usually, very low quality. This means we are unsure of the results.

Conclusions

The review concluded that there is insufficient evidence to inform on the role of percutaneous pinning and associated treatment decisions. While further research is needed, we advise waiting on the results of a large ongoing study comparing pinning with plaster cast treatment.

Authors' conclusions: 

Overall, there is insufficient RCT evidence to inform on the role of percutaneous pinning versus cast immobilisation alone or associated treatment decisions such as method of pinning, burying or not of wire ends, wrist position and duration of immobilisation after pinning. Although very low-quality evidence, the serious complications associated with biodegradable materials is noteworthy. We advise waiting on the results of a large ongoing study comparing pinning with plaster cast treatment as these could help inform future research.

Read the full abstract...
Background: 

Fracture of the distal radius is a common clinical problem. A key method of surgical fixation is percutaneous pinning, involving the insertion of wires through the skin to stabilise the fracture. This is an update of a Cochrane Review published in 2007.

Objectives: 

To assess the effects (benefits and harms) of percutaneous pinning versus cast immobilisation alone and of different methods and techniques of percutaneous pinning, modalities or duration of immobilisation after pinning, and methods or timing of pin or wire removal for treating fractures of the distal radius in adults. Our primary focus was on dorsally displaced fractures.

Search strategy: 

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, trial registers, conference proceedings and reference lists of articles up to June 2019.

Selection criteria: 

Randomised or quasi-randomised controlled clinical trials involving adults with a fracture of the distal radius, which compared percutaneous pinning with non-surgical treatment or different aspects of percutaneous pinning. Our main outcomes were patient-reported function at the short term (up to three months), medium term (three up to 12 months) and long term (greater than 12 months); overall numbers of participants with complications requiring secondary treatment and any complication; grip strength and health-related quality of life at 12 months.

Data collection and analysis: 

At least two review authors independently performed study screening and selection, 'Risk of bias' assessment and data extraction. We pooled data where appropriate and used GRADE for assessing the quality of evidence for each outcome.

Main results: 

We included 21 randomised controlled trials (RCTs) and five quasi-RCTs, involving 1946 generally older and female adults with dorsally displaced and potentially or evidently unstable distal radial fractures. Trial populations varied but the majority of studies reported mean ages in the sixth decade or older. All trials were at high risk of bias, invariably performance bias - which for most trials reflected the impracticality of blinding care providers or participants to treatment allocation - and often detection bias and selective reporting bias. Allocation concealment was secure in one trial only. All trials reported outcomes incompletely. The studies tested one of 10 comparisons. In the following, we report on those of the main outcomes for which evidence was available. No subgroup analysis, such as by pinning methods, was viable.

Eleven heterogeneous trials involving 917 participants compared percutaneous pinning with plaster cast immobilisation after closed reduction of the fracture. The quality of the evidence was very low for all reported outcomes. Thus, we are uncertain if percutaneous pinning compared with plaster cast alone makes any difference to patient-reported function, measured using the DASH questionnaire, at six weeks or six months (incomplete data from one trial). Overall numbers of participants with complications were not reported. Redisplacement resulting in secondary treatment occurred on average in 12% (range 3.3% to 75%) of participants treated by cast alone (six trials) whereas pin tract infection requiring antibiotics and, often, early wire removal, occurred on average in 7.7% (range 0% to 15%) of pinning group participants (seven trials). We are uncertain whether pinning makes a difference to the incidence of complex regional pain syndrome, reported in four studies. Although two studies found finger stiffness after cast removal was less common after pinning (20% versus 36%), the treatment implications were not reported. Other reported complications were mainly surgery-related. Based on incomplete data or qualitative statements from only four studies, we are uncertain of the effects of pinning on grip strength at 12 months. We are uncertain if percutaneous pinning compared with plaster cast alone makes any difference to patient-reported quality of life at four months (one study).

Five comparisons of different pinning methods were made by six trials in all. One of these trials, which reported results for 96 participants, compared Kapandji intrafocal pinning (2 or 3 wires) with early mobilisation versus trans-styloid fixation (2 wires) with six weeks cast immobilisation. We are uncertain whether Kapandji pinning slightly increases the risk of superficial radial nerve symptoms or complex regional pain syndrome, or whether it makes a difference in grip strength at 12 months (very low-quality evidence).

Two small trials using two distinct pinning techniques compared biodegradable pins versus metal pins in 70 participants. Although very low-quality evidence, the extra demands at surgery of insertion of biodegradable pins and excess of serious complications (e.g. severe osteolytic reactions) associated with biodegradable material are important findings.

Three poorly-reported trials involving 168 participants compared burying of wire ends versus leaving them exposed. We are uncertain whether burying of wires reduces the incidence of superficial infection (very low-quality evidence). There is low-quality evidence that burying of wires may be associated with a higher risk of requiring more invasive treatment for wire removal.

Four small trials compared different types or duration of postoperative immobilisation. Very low-quality evidence of small between-group differences in individual complications and grip strength at 17 weeks, means we are uncertain of the effects of positioning the wrist in dorsiflexion versus palmar flexion during cast immobilisation following pinning of redisplaced fractures (one trial; 60 participants). Three small heterogeneous trials compared cast immobilisation for one week (early mobilisation) versus four or six weeks after percutaneous pinning in 170 people. Although we note one trial using Kapandji pinning reported more complications in the early group, the very low-quality evidence means there is uncertainty of the effects of early mobilisation on overall and individual complications, or grip strength at 12 months.

No trials tested different methods for, or timing of, pin/wire removal.