Outcomes of Supplementary Spring Wire Fixation With Volar Plating for Volar Lunate Facet Fragments in Distal Radius Fractures

Abstract

Background

Intra-articular distal radius fractures with small volar lunate facet fragments can be challenging to address with volar plate fixation alone. Volar locked plating with supplementary spring wire fixation has been previously described in a small series but has not been further described in the literature. We hypothesized that this technique can provide adequate fixation for volar lunate facet fragments smaller than 15 mm in length, which are at risk of displacement.

Methods

We completed a retrospective chart review (2015-2019) of patients who underwent volar locked plating with the addition of supplementary spring wire fixation for intra-articular distal radius fractures with a volar lunate facet fragment (<15 mm). Postoperative radiographs were assessed to evaluate union, evidence of hardware failure, escape of the volar lunate facet fragment, and postoperative volar tilt. Clinical outcome was assessed with wrist flexion/extension, arc of pronosupination, and Quick Disabilities of the Arm, Shoulder, and Hand Score (QuickDASH) scores.

Results

Fifteen patients were identified, of which all went on to fracture union. There were no hardware failures or escape of the volar lunate facet fragment at final follow-up. One patient underwent hardware removal for symptoms of flexor tendon irritation. The mean wrist flexion was 59°, wrist extension was 70°, pronation was 81°, and supination was 76°. The mean QuickDASH score was 18.5. The mean postoperative volar tilt was 3.6°.

Conclusions

Supplementary spring wire fixation with standard volar plating provides stable fixation for lunate facet fragments less than 15 mm. This technique is a safe and reliable alternative to commercially available fragment-specific implants.

Introduction

Intra-articular distal radius fractures with small volar lunate facet (VLF) fragments are difficult to address with traditional volar locked plating. ¹ Loss of fixation and volar carpal subluxation can be seen after fixation of these fractures with standard volar plates alone.^2-8 Various methods for fixation of the lunate facet fragment have been described, including loop wiring, arthroscopic-assisted Kirschner wire (K-wire) constructs, tension band constructs, headless compression screws, hook plating, volar rim plates, and fragment-specific implants.^9-15 In 2014, Moore and Dennison ¹⁶ published a series of 9 patients treated with supplementary spring wire fixation in addition to standard volar locked plating. The authors reported that all fractures healed with maintained reduction of the VLF fragment. This technique is promising as it allows the use of standard volar plate implants with the addition of 1 to 3 small K-wires, uses standard surgical approaches and implants, and can address a wide range of comminuted intra-articular fractures of the distal radius. As such, successful application of this technique will allow the surgeon to be able to address a small VLF fragment if found unexpectedly while also not requiring any special hardware beyond a standard volar plate (such as what may be available in a small outpatient surgicenter or resource-restricted environment).

Beck et al ¹ reported that AO type B3 fractures that have a VLF fragment with less than 15 mm available for fixation are at risk of displacement even with an appropriately placed volar plate. While placement of a volar plate distal to the watershed may aid in capturing a small VLF and stabilize the intermediate column, distally positioned implants can be associated with multiple complications, including the potential for increased rates of flexor tendon rupture as well as disruption of the insertion of volar radiocarpal ligaments.^17,18 We hypothesized that using a supplementary K-wire for a spring wire technique for VLF fragments less than 15 mm would provide adequate fixation and prevent escape of the VLF (Figure 1). Outside of the original 9-patient series by Moore and Dennison, ¹⁶ no other study has reported outcomes on supplementary spring wire fixation with volar plating. In this study, we report the outcomes of our series.

Figure 1.

Variants of coronal (a, b) and sagittal (c) three dimensional renderings of a comminuted, intra-articular distal radius fracture with a small volar lunate facet fragment.

Materials and Methods

After obtaining institutional review board approval, we conducted a retrospective chart review of all patients at least 18 years of age with an intra-articular distal radius fracture who underwent operative fixation with a VLF fragment with a volar plate and supplementary K-wire fixation. All cases were performed by a single fellowship-trained hand surgeon at 1 institution from November 2015 to July 2019. Patients with less than 12 weeks of follow-up were excluded.

Fifteen patients were included in the cohort. Patient age, AO fracture classification, length of follow-up, implants used, and additional surgical procedures performed were extracted from the medical record. Radiographic outcomes were assessed with posteroanterior (PA), oblique, and lateral view radiographs of the wrist obtained at postoperative visits. Radiographic union and escape of the VLF were determined on imaging from each patient’s final follow-up visit. Quick Disabilities of the Arm, Shoulder, and Hand Score (QuickDASH) scores and measurements of wrist flexion, wrist extension, pronation, and supination were extracted from the medical record.

Surgical Technique

All patients were placed supine, and a proximal arm pneumatic tourniquet was placed. A trans-flexor carpi radialis (FCR) approach to the distal radius was used. A 7-cm incision was made over the FCR. The extra-articular fracture was visualized and the radial column provisionally reduced under fluoroscopic guidance and held with temporary K-wires through the radial styloid. Depending on the details of each individual case and its associated fragments, additional K-wires were often used for temporary fixation. A dental pick was often used to aid in reduction of the lunate facet fragment. Once a satisfactory reduction was obtained, a 0.035-in K-wire was placed through the fragment into the proximal dorsal cortex (Figure 2). The K-wires were also used as a reduction tool in some cases, being passed into the fragment itself and then used as a joystick to manipulate the position of the fragment. Once the fragment was in satisfactory position, the wire was then passed into the dorsal cortex to secure it in place. The K-wire was then bent to fit the contour of the volar distal radius in situ or removed, and a prebent wire was then placed. The size and stability of the VLF fragment dictated the number of wires that were used. The volar plate was then placed over the bent wire or wires and secured in the appropriate position. Following confirmation of satisfactory screw and plate position on fluoroscopy, the wound was irrigated and closed. Patients were placed into a removable wrist brace for a period of 2 weeks.

Figure 2.

(1) Lateral view of a distal radius fracture with a small displaced volar lunate facet fragment. (2) A 0.035-in Kirschner wire (K-wire) is placed into the displaced volar lunate facet fragment. (3) Using the K-wire as a reduction aid, the volar lunate facet fragment is reduced, and the K-wire is advanced into the main dorsal distal fragment. (4) The K-wire is then contoured to the volar cortex. (5) The volar locked plate is then fixed to the radial shaft with K-wire secured beneath the plate. (6) The intermediate column is then reduced to the plate with a Weber clamp. (7a, 7b) Anteroposterior and lateral views of the construct after final screw fixation.

Results

Fifteen patients with a mean age of 50 years (range: 32-80 years) were evaluated. The mean follow-up was 37 weeks (range: 12-156 weeks). Nine patients were women and 6 were men, with a mean age of 50 years (range: 32-80 years). Radiographs demonstrated union in all patients. No patients had subsequent escape of the VLF fragment, volar subluxation of the carpus, loss of reduction of the articular surface, or implant failure. The mean volar tilt on lateral radiograph was 3.0° ± 8.1°. The postoperative mean wrist flexion was 59° ± 22°, the mean wrist extension was 70° ± 16°, the mean pronation was 80° ± 5°, and the mean supination was 76° ± 10° (Table 1). QuickDASH was performed in all 15 patients, with a mean score of 18.5 (range: 12-26) at final follow-up. The mean time from injury to surgical intervention was 12 days (range: 5-29 days).

Table 1.

Patient Data.

Case	Age/Sex	Fixation	Length of follow-up, wk	Wrist F/E	Wrist P/S	QuickDASH score
1	52/F	Volar plate with 1 spring wire pin	47	30/60	85/80	23/11
2	43/F	Volar plate with cancellous chips, 2 spring wire pins	22	90/90	90/90	17/11
3	34/F	Volar plate with 1 spring wire pin	12	80/90	70/80	13/11
4	45/F	Volar plate with 1 spring wire pin	23	70/90	90/90	15/11
5	34/M	Volar plate with 1 spring wire pin	17	60/70	80/80	17/11
6	48/M	Volar plate with 1 spring wire pin	55	85/85	80/80	13/11
7	25/M	Volar plate with 1 spring wire pin	19	90/90	80/90	14/11
8	80/F	Volar plate with 1 spring wire pin	156	45/57	85/70	17/11
9	76/M	Volar plate with 2 spring wire pins	47	45/70	75/50	12/11
10	42/F	Proximal volar plate with 3 spring wire pins	28	60/70	80/80	15/11
11	76/M	Volar plate with cancellous chips, 2 radial styloid K-wires, 1 spring wire pin	45	60/70	80/70	24/11
12	32/M	Volar plate with cancellous chips, 2 spring wire pins	26	50/50	80/80	19/11
13	55/F	Volar plate with 2 spring wire pins	26	40/55	75/70	25/11
14	33/F	Volar plate with 1 spring wire pin	14	70/60	80/70	26/11
15	75/F	Volar plate with cancellous chips, 3 spring wire pins	12	15/45	80/70	27/11

Note. M = male; F = female; P/S = pronation/supination; F/E = flexion/extension; QuickDASH = Quick Disabilities of the Arm, Shoulder, and Hand Score.

The right wrist was injured in 10 patients and the left in 5. Twelve cases were AO classification type C, with the remaining 3 cases being type B. All patients had an independent VLF fragment less than 15 mm, and all fractures were closed. Fourteen patients underwent fixation with the Acu-Loc 2 volar plating system (Acumed, Hillsboro, Oregon) and 1 patient with a 2.4-mm variable angle locking compression plate (Synthes, West Chester, Pennsylvania). A single K-wire was used to fix the lunate facet fragment in 9 patients, 2 K-wires in 4 patients, and 3 K-wires in 2 patients. Cancellous allograft was used in 4 patients. The decision to use allograft was made on a case-by-case basis by the fellowship-trained hand surgeon depending on whether a bone defect was present after reduction was obtained intraoperatively.

One patient had supplemental fixation in the form of additional K-wire fixation through the radial styloid to address an additional radial styloid fragment. One patient had a concomitant carpal tunnel release for preoperative carpal tunnel symptoms. One patient underwent open reduction internal fixation for an ipsilateral scaphoid fracture, in addition to closed treatment of an ipsilateral capitellum fracture. One patient had an ipsilateral distal ulna fracture that was not surgically addressed. One patient underwent closed reduction percutaneous pinning for third, fourth, and fifth carpometacarpal dislocations and an associated third metacarpal fracture.

One patient underwent hardware removal after reporting symptoms of flexor tendon tenosynovitis 8 months postoperatively. Hardware removal was uneventful, and symptoms resolved. There were no other complications related to distal radius fracture fixation.

Discussion

Our series supports the findings of Moore et al that supplementary spring wire fixation with volar plating provides adequate fixation for distal radius fractures with VLF fragments less than 15 mm in length. All 15 patients we treated and evaluated postoperatively went on to union without escape of the VLF fragment. QuickDASH scores and range of motion outcomes demonstrate that these patients returned to functional use of the extremity without significant deficit. One of 15 patients (6.7%) required hardware removal for symptoms of flexor tenosynovitis. This rate is less than the implant removal rate (as high as 10%) reported in a large series of patients treated with a standard volar plate fixation for a distal radius fracture. ¹⁹ No additional modalities such as external fixation or dorsal ulnar corner pinning were used in our series, which had been cited in the prior description of this technique as a possible explanation for the excellent results. However, it is important to note that all patients in their series sustained AO type C3 fractures, and it potentially represented a more severe cohort of injuries than our study.

Although using a volar locked plate with supplemental K-wire fixation is a reliable method by which to achieve union for this fracture pattern, other techniques have been described. Minato et al ⁹ reported a loop-wiring technique for thin volar marginal fragments. Using a combined volar and dorsal approach, they describe using 2 K-wires drilled at the tip of the reduced VLF fragment into the dorsal cortex. Two bone tunnels were made proximal to the K-wires, and a 0.028-in soft wire was passed through the tunnels and tightened dorsally. This technique benefits from rotational stability from the K-wires and compressive forces at the articular surface from the loop wire construct. However, the technique is technically challenging, and the K-wires have the potential to back out over time. Harness ¹² reviewed 5 patients with VLF fragments that were addressed with a range of techniques, including independent headless compression screws, independent cortical screws, and a tension band construct where a 26-gauge dental wire was wrapped around supplementary K-wires placed through the unstable fragment. Although independent screw fixation is low profile and familiar to many surgeons, a volar ulnar approach is often required for optimal visualization and screw trajectory. Kachooei et al ¹⁴ reported on 7 patients who underwent fixation with a volar rim plate. They did not report any cases of loss of reduction, although this requires having this hardware available. O’Shaughnessy et al reported a series of 26 wrists with volar marginal rim fractures that were treated with fragment-specific volar hook plates. There were no cases of loss of reduction, although 4 patients underwent hook plate removal for symptomatic hardware and, like other descriptions, required special commercially available hardware. ¹³ These less frequently used specialty implants can also be more expensive, especially when compared with K-wire fixation and standard volar locked plating implants.

The supplementary spring wire technique avoids many of the issues encountered when using other fixation techniques. The technique is easily integrated with fixation of other fragments with standard volar plates through a trans-FCR approach (or extended approach). This allows the surgeon to use this method even if the presence of a small VLF is not identified on preoperative imaging and does not require the use of any specialty plates. The supplementary wires are secured by the overlying plate, preventing them from backing out and becoming symptomatic (Figure 3). K-wire fixation allows for fixation in the distal-most aspect of the fragment while sparing the volar radiocarpal ligaments, and the low profile of the final construct limits potential surrounding soft tissue irritation. Finally, surgeons are familiar with working with K-wires, and this technique is technically simple and easily adoptable into practice.

Figure 3.

(a) Injury posteroanterior (PA), (b) lateral and (c) postfixation PA, and (d) lateral radiographs of a comminuted, intra-articular distal radius fracture with a small volar lunate facet fragment.

Note. Two Kirschner wires were used to provide supplemental fixation into the volar lunate facet fragment.

Our study should be viewed in the context of its limitations. The sample size reported is small. Furthermore, this is a single-surgeon study of a relatively rare fracture pattern, and thus we do not have an alternative fixation method to which we can compare. In addition, we report a mean follow-up of 37 weeks, which may be insufficient to capture late complications related to surgery, particularly flexor tendon irritation. However, 37-week mean follow-up should be sufficient to capture many important outcomes including loss of reduction and hardware failure. ²⁰

This larger series study supports that supplementary K-wire fixation for distal radius fractures with small VLF fragments is reliable for achieving union with a low rate of complication and can be scaled to all settings, regardless of resource limitations.