Volar Plating: Imaging Modalities for the Detection of Screw Penetration

Cause of Extensor Pollicis Longus Ruptures After Distal Radius Fracture Fixation Using a Volar Plate

BACKGROUND

This research sought to analyze a cohort of patients with extensor pollicis longus (EPL) ruptures after volar locked plating of a distal radius fracture (DRF) to characterize the incidence of ruptures that are unlikely to be related to dorsal screw prominence.

METHODS

This is a retrospective, observational, descriptive cohort study of adults with operative fixation of a closed DRF and an EPL rupture between 2002 and 2022. Eighteen patients with operative fixation using a volar plate of a closed DRF had an EPL rupture. The cohort consisted of 66% women with an average age of 57.5 years. Median follow-up was 14.5 months.

RESULTS

The incidence of EPL rupture was 0.4% (18/4768). The average time from DRF and DRF fixation to EPL rupture was 3.7 and 3.4 months, respectively. Based on the operative record, in 2 of the 18 patients (11%), the rupture was directly attributable to prominent hardware; however, in 4 of the 18 patients (22%), the rupture was not related to prominent hardware, and the cause was indeterminate in 12 patients (67%). Radiologic analysis of those in the indeterminate group demonstrated that 5 of the 12 patients had screws that had a high probability of being prominent.

CONCLUSIONS

The incidence of EPL rupture after volar plating of DRF is between 0% and 1% and usually occurs about 3 months after fixation. Approximately 50% of EPL ruptures are attributable to prominent dorsal screws. Although screw prominence is an important cause of EPL rupture, it is not the sole cause of rupture.

[Standardized reduction and palmar plating of dorsally displaced distal radius fractures for safe and atraumatic reconstruction of the anatomy of the radius]

OBJECTIVE

Standardization of palmar plate osteosynthesis in order to consequently achieve physiologic anatomy of the distal radius end.

INDICATIONS

Unstable dorsally displaced distal radius fractures or fractures that should be treated functionally.

CONTRAINDICATIONS

Severe intraarticular joint depression that cannot be reduced with either a palmar or arthroscopic assisted approach.

SURGICAL TECHNIQUE

Patient in supine position with the forearm supinated on arm table. Radiopalmar incision along the radial border of the flexor carpi radialis tendon. Detachment of the pronator quadratus muscle from radial to ulnar. Gross reduction with eventual correction of a dorsal or radial shift. Placement of the angular stable plate and preliminary fixation with a nonangular stable cortical screw in the long hole at the radius shaft. Fluoroscopic control of axial alignment in the anteroposterior view and of correct distal position of the plate in the lateral view under reduction condition. Placement of one or two angular stable screws at the shaft. Under subtle reduction with flexion, ulnar deviation and axial traction placement of two K‑wires via the holes at the distal edge of the plate. These wires mostly keep reduction maintained while reduction maneuver can be paused. Fluoroscopic control in two planes. Replacement of the wires by distal angular stable screws with the help of the wires as an orientation. In case of insufficient reduction, reduction maneuver can be repeated while the first angular stable screw is locked. Final fluoroscopic control in two planes and ulnar deviation, eventually also in tangential view and clinical testing for stability of the distal radioulnar joint. Wound closure only by skin suture. Application of a sterile dressing and a palmar cast.

POSTOPERATIVE MANAGEMENT

Arm consequently in upright position and active and complete movement of fingers. Palmar below-elbow cast for 2 weeks, then movement of wrist without exertion. After regular radiographic control 4-5 weeks postoperatively, increase of axial load to normal and, if needed, physiotherapy. Clinical control for irritation of tendons by plate or screws after 1 year and eventual plate removal.

Is ultrasound superior to fluoroscopy in distal radius volar fixation?

OBJECTIVES

In volar distal radius fixation, conventional and additional fluoroscopic views could not be sufficient to assess dorsal screw penetration. Ultrasound (US) has been suggested as a technique to improve this assessment. The objective was to determine the agreement between these two explorations in a clinical study. Quantify time-consuming of intraoperative US was the secondary objective.

MATERIAL AND METHODS

A prospective descriptive study was performed. Thirty patients with a surgical distal radius fracture were treated with volar fixation by five consultant surgeons in a level I Trauma Centre. Final intraoperative fluoroscopic views: AP, lateral, 20º tilted lateral and Dorsal Tangential views (DTV) were performed assessing for dorsal screw protrusion. Then, ultrasound was performed to reassess dorsal cortex integrity. Those protruding screws were registered and changed.

RESULTS

A total of 153 screws were examined. Four protruding screws were observed with no multiple protruding screws in the same fixation. Intraoperative ultrasound detected a dorsal screw protrusion in one fixation, assessed as correct by radiological projections. Almost perfect agreement was found between DTV and US examination k = 0.83 (p < 0.001). The mean surgical time was 63 ± 20.3 min while the addition of the ultrasound, supposed an average of 4 ± 1 min more.

CONCLUSION

Ultrasound did not show a clinically significant improvement in the assessment dorsal screw penetration in distal radius fixation. A high agreement was observed between US and the described fluoroscopic views. The addition of intraoperative US was a non-significant time-consuming procedure.

Anatomic Risks with Overpenetration of the Volar Locking Plates' Proximal Holes

Background  Volar locking plate fixation (VLP) is commonly used to treat distal radius fractures (DRF). Risk of dorsal compartment injury with distal screw hole fixation has been studied; however, the risk with proximal screw hole fixation is not well studied. Purpose  The goal of this study was to investigate the risk of dorsal structure injury from the screw holes proximal to the two distal rows. Methods  Nine cadaveric forearms were used. After volar distal radius exposure, a long VLP was applied. Kirschner wires were placed through the most proximal holes into the dorsal compartments. The extensor structures penetrated were noted and tagged with hemoclips. The distance from the dorsal cortex to the structures was measured. Results  The abductor pollicis longus (APL) and extensor pollicis brevis (EPB) muscle bodies were only penetrated; no tendons were penetrated. Proportion of muscle penetration increased with the more proximal screw holes. EPB was more likely to be penetrated distally and APL proximally; both were injured at holes 2 and 3. The extensors were 2 mm from the dorsal cortex of the radius on average; this did not decrease with compression of the forearm. Conclusions  This is the first study to examine the anatomic risk of extensor structure injury with VLP proximal screw hole penetration. No extensor tendons were penetrated by these proximal screw holes; first dorsal compartment muscle bellies may be irritated with overpenetration. Our findings suggest that proximal VLP screws do not need to be downsized if they are not over 2 mm prominent.

Is tendinitis in volar plating related to the dorsally protruding screw length and its compartment?

OBJECTIVES

The aim of this study was to evaluate the relationship between the length of the protruded screws from the dorsal cortex and extensor tendon damage in all compartments.

PATIENTS AND METHODS

Between May 2020 and April 2021, a total of 29 patients (13 males, 16 females; mean age: 52.3±13.0 years; range, 30 to 78 years) who were operated and followed in our clinic for AO A2 and A3 distal radius fractures were included in this prospective study. Surface ultrasound (US) imaging was made to the dorsal sides of both wrists of the operated patients at different timepoints postoperatively. The length of screws with radius dorsal cortex penetration and the presence of tendinitis were recorded.

RESULTS

In 15 of 23 patients, the presence of 29 protruding screws was accompanied by tendinitis and, in eight patients, no tendinitis was observed, despite the partial protrusion of screws. A statistically significant correlation was found between the screw protrusion and presence of tendinitis (p<0.05). The number of protruding screws and tendinitis were seen mostly in the second compartment. There was a statistically significant correlation between the protruding screw length of >1.6 mm and the presence tendinitis (p<0.05).

CONCLUSION

Dorsal cortex screw protrusions in the application of volar plate for distal radius fractures can cause tendinitis. Screw protrusions occur more frequently in the second compartment and the development of tendinitis in this compartment is associated with a screw length of >1.6 mm. Screw penetration can be easily identified with intraoperative US to prevent tendinitis and potential tendon ruptures.

Extensor Tendon Injury After Volar Locking Plating for Distal Radius Fractures: A Systematic Review

Distal radius fractures are common orthopedic injuries. Treatment has varied historically, but volar locking plating currently predominates. Although flexor tendon injury is a well-studied complication of this operation, extensor tendon injury is less well studied. The purpose of this review is to search the literature and present the epidemiology, presentation, and treatment of this complication. The Cochrane, EMBASE, PubMed, and SCOPUS databases were searched for the terms "volar" + "radius" + ("plate" OR "plating") + "extensor." Ninety final studies were included for analysis in this review. The incidence of extensor tendon rupture varies from 0% to 12.5%; the extensor pollicis longus is most commonly ruptured. The presentation and management of extensor tendon injury after injury, intraoperatively, and postoperatively are summarized. Radiographic views are described to detect screw prominence and minimize intraoperative risk. Extensor tendon injury after volar locking plate for distal radius fractures is an uncommon injury with several risk factors including dorsal screw prominence and fracture fragments. Removal of hardware and tendon transfers or reconstruction may be necessary to prevent loss of extensor mechanism.

Comparison of a ceiling-mounted 3D flat panel detector vs. conventional intraoperative 2D fluoroscopy in plate osteosynthesis of distal radius fractures with volar locking plate systems

Objectives

To compare intraoperative 3D fluoroscopy with a ceiling-mounted flat panel detector in plate osteosynthesis of distal radius fractures (AO/OTA 2R3C1.2) with volar locking plate systems to conventional 2D fluoroscopy for detection of insufficient fracture reduction, plate misplacement and protruding screws.

Methods

Using a common volar approach on 12 cadaver forearms, total intraarticular distal radius fractures were induced, manually reduced and internally fixated with a 2.4 distal radius locking compression plate. 2D (anterior-posterior and lateral) and 3D (rotational) fluoroscopic images were taken as well as computed tomographies. Fluoroscopic images, Cone Beam CT (CBCT), 360° rotating sequences (so called “Movies”) and CT scans were co-evaluated by a specialist orthopedic surgeon and a specialist radiologist regarding quality of fracture reduction, position of plate, position of the three distal locking screws and position of the three diaphyseal screws. In reference to gold standard CT, sensitivity and specifity were analyzed.

Results

“Movie” showed highest sensitivity for detection of insufficient fracture reduction (88%). Sensitivity for detection of incorrect position of plate was 100% for CBCT and 90% for “Movie.” For intraarticular position of screws, 2D fluoroscopy and CBCT showed highest sensitivity and specifity (100 and 91%, respectively). Regarding detection of only marginal intraarticular position of screws, sensitivity and specifity of 2D fluoroscopy reached 100% (CBCT: 100 and 83%). “Movie” showed highest sensitivity for detection of overlapping position of screws (100%). When it comes to specifity, CBCT achieved 100%. Regarding detection of only marginal overlapping position of screws, 2D fluoroscopy and “Movie” showed highest sensitivity (100%). CBCT achieved highest specifity (100%).

Conclusion

As for assessment of quality of fracture reduction and detection of incorrect position of plate as well as overlapping position of the three diaphyseal screws CBCT and “Movie” are comparable to CT – especially when combined. Particularly sensitivity is high compared to standard 2D fluoroscopy.

3D virtual pre-operative planning may reduce the incidence of dorsal screw penetration in volar plating of intra-articular distal radius fractures

Purpose

To evaluate the effect of three-dimensional virtual pre-operative planning (3DVP) on the incidence of dorsal screw penetration after volar plating of distal radius fractures.

Methods

A cross-sectional diagnostic imaging study was performed. Twenty out of 50 patients were randomly selected from our index prospective cohort (IPC): a prior study evaluating dorsal tangential views (DTVs) in reducing dorsal screw penetration in internal fixation of intra-articular distal radius fractures using post-operative CT scans to quantify screw protrusion. Pre-operative CTs from this cohort were now used for 3DVP by three experienced orthopaedic trauma surgeons (supplementary video). 3DVP was compared with the corresponding post-operative CT for assessing screw lengths and incidence of dorsal penetration. The Wilcoxon Signed Ranks test was used to compare screw lengths and the Fishers’ exact for incidence of penetration.

Results

Three surgeons performed 3DVP for 20 distal radius fractures and virtually applied 60 volar plates and 273 screws. Median screw length was shorter in the 3DVP when compared to IPC: 18 mm (range, 12–22) versus 20 mm (range, 14–26) (p < 0.001). The number of penetrating screws was 5% (13/273 screws) in the 3DVP group compared to 11% (10/91 screws) in the IPC (p = 0.047). Corresponding to a reduction in incidence of at least one dorsally penetrating screw in 40% of patients in the IPC group, to 18% in the 3DVP group (p = 0.069).

Conclusion

Three-Dimensional Virtual Pre-Operative Planning (3DVP) may reduce the incidence of dorsally penetrating screws in patients treated with volar plating for intra-articular distal radius fractures.

Level of evidence

II, diagnostic imaging study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01800-2.

Radiography of the Distal Radius

Imaging of the distal radius is of paramount importance in diagnosing injuries, indicating patients for operative or nonoperative treatment, and appropriately following patients for associated injuries and complications. Plain radiographs and fluoroscopy are the dominant imaging modalities in all settings because they are readily available and provide valuable information about the osseous structures and any instrumentation. Computed tomography can offer more information about implant placement and the level of comminution of the articular surfaces but is more expensive and exposes patients to higher doses of radiation. Magnetic resonance imaging is less commonly used but is useful for occult fractures and other associated injuries. Ultrasonography is gaining popularity in evaluating implant placement, especially regarding tendon impingement and subsequent tendon injury.

A Prospective Cohort Study on Accuracy of Dorsal Tangential Views to Avoid Screw Penetration With Volar Plating of Distal Radius Fractures

OBJECTIVE

To assess diagnostic performance of dorsal tangential views (DTVs) to detect dorsal screw protrusion in clinical practice.

DESIGN

Prospective cohort study.

SETTING

Level-1 trauma center.

PATIENTS

Fifty consecutive patients undergoing volar plating for 50 distal radius fractures were prospectively included.

INTERVENTION

Fluoroscopic DTVs were routinely obtained, and screw revision was documented. Multiplanar reconstructions of postoperative CTs allowed for detection and quantification of dorsal screw penetration using reproducible measuring techniques.

MAIN OUTCOME MEASUREMENTS

Diagnostic performance (sensitivity, negative predictive value, positive predictive value, and accuracy) of DTV.

RESULTS

Intraoperatively, in 16 of 50 patients (32%), screws were revised based on DTV, with 13 of 218 screws (6.0%) being revised due to dorsal prominence. One screw was changed because DTV showed it was in the distal radioulnar joint. Postoperatively, in 10 patients (20%), the computed tomography revealed 12 additional screws penetrating ≥1 mm with an average of 1.8 mm (range 1.0-4.5 mm). DTV had a sensitivity of 52%, a negative predictive value of 95%, and accuracy of 95%. No ≥1-mm protruding screw remained in the third compartment.

CONCLUSIONS

In one-third of our patients, the incidence of protruding screws that can cause iatrogenic extensor tendon rupture was reduced by obtaining additional DTVs. Although DTV reduces the incidence of dorsal screw penetration considerably, this study reveals limited sensitivity. Therefore, one should keep in mind that dorsal screw penetration may go unnoticed on DTVs, and proper surgical technique remains paramount of DTV.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.