Detections of Screw Penetration during Volar Plating for Distal Radius Fractures

Optimal screw length in volar locking plate osteosynthesis for distal radius fractures: a systematic review

BACKGROUND

Fractures of the distal radius represent the most common fracture of the upper limb, and can be managed surgically with volar locking plate osteosynthesis (VLPO). Uncertainty remains regarding the optimal length of the distal locking screws. The aim of this study was to determine the optimal VLPO screw length which provided adequate stability while minimizing complications.

METHODS

A systematic review of relevant literature published within Cochrane, PubMed, MEDLINE and Embase, including studies up to April 2020, was performed using the Preferred Reporting Items for Systemic Reviews and Meta-analysis (PRISMA) guidelines. Studies were included if they investigated distal radius fracture fixation with VLPO, screw lengths, complications, and associated imaging.

RESULTS

Search results identified 664 relevant studies, of which 14 studies examining 926 radii were included for review. Synthesis revealed that unicortical locking fixation with screws ~75% the depth of the radius, or 2 mm short of the dorsal cortex, provided equivalent stability to bicortical fixation. The lunate may be used as a proxy to determine radial depth at each quartile column. Inadvertent screw protrusion can be assessed by taking four images intra-operatively; anteroposterior (AP), lateral, 45° supinated and dorsal tangential views (DTVs). Radial shaft screws can have up to 2 mm prominence with no clinical significance.

CONCLUSION

Unicortical locking fixation at least 75% the depth of the distal radius provides equivalent stability to bicortical fixation in extra-articular fractures with lower complication rates. Imaging should be used to confirm that penetration of the dorsal cortex has not occurred.

Influence of training on dorsal tangential radiographic view to detect screw protrusion after anterior plating of the distal radius: a cadaveric study

In this cadaveric study of anterior plating of the distal radius, we aimed to determine the interobserver agreement and diagnostic performance for detecting dorsally protruding screws using the dorsal tangential radiographic view before and after specific training. Without prior instruction, 13 observers interpreted the dorsal tangential view of cadaveric specimens, in which anterior radial plates were placed. After seeing a training video on the dorsal tangential view, they repeated the task. Though we found that accuracy and interobserver agreement was lower than described in some other clinical series, training led to statistically significant improvements of (1) the interobserver agreement on the decision to exchange screws, (2) the self-confidence of the surgeon in obtaining adequate views, and (3) the number of fluoroscopic images required to obtain these views. After training, the number of protruding screws missed was reduced by 36%, but 7% of dorsally protruding screws was still missed.

Diaphyseal Screw Prominence in Distal Radius Volar Plating

Background  Volar plating for distal radius fractures has become common. Screw prominence on the dorsal side from long screws can lead to tendon injury. Methods for detecting screws that penetrate the far cortex involve X-ray or ultrasound. These have focused on the distal row of screws. No studies have addressed screw penetration in the diaphysis. We describe two cases where diaphyseal screws caused symptoms. We then insert screws in the diaphysis of synbones 2 mm longer than measured and determine what angle of pronation or supination was best to detect this on X-ray. Methods  Three synbones were plated using Synthes volar plate. The three diaphyseal screws were drilled perpendicular to the plate, and the depth measured. Cortical 2.4-mm screws were inserted, 2 mm longer than measured. The three synbones were then placed in a custom clamp to measure rotation. Lateral X-rays were taken at 0 degree rotation, and 5, 10, and 15 degrees of supination and pronation. The prominence of each screw was measured using the synapse digital ruler. Results  For the screws that were placed at a neutral angle (perpendicular to the plate) the maximum visualization of the prominent tips occurred around 0 degree rotation. With screws angled 15 degrees ulna, maximum visualization was between 5 and 10 degrees of pronation. With screws angled 15 degrees radial, maximum visualization was between 5 and 10 degrees of supination. Every 5 degrees of rotation changes the profile of the screw by 0.4 mm. Discussion  The diaphysis of the radius becomes approximately trapezoidal distally. Prominent screws that are placed below the "peak" of the trapezoid may appear to be the correct length. Rotating the wrist into pronation or supination to bring the relevant cortex as parallel to the X-ray beam as possible will help to identify if screws are of the correct length. Screws that are prominent in the second compartment may be particularly symptomatic as the tendons here are closely opposed to the bone. We recommend screening for 2 mm diaphyseal screw prominence in neutral, with 10 degrees of pronation and supination.

Volar Plating: Imaging Modalities for the Detection of Screw Penetration

Background  Volar plating for distal radius fractures exposes the risk of extensor tendon rupture, mechanical problems, and osteoarthritis due to protruding screws. Purposes  The purpose of this review was to identify the best intraoperative diagnostic imaging modality to identify dorsal and intra-articular protruding screws in volar plating for distal radius fractures. Methods  The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed for this review. In vitro and in vivo studies that analyzed the reliability, efficacy, and/or accuracy of intraoperatively available imaging modalities for the detection of dorsal or intra-articular screw protrusion after volar plating for distal radius fractures were included. Results  Described additional imaging modalities are additional fluoroscopic views (pronated views, dorsal tangential view [DTV], radial groove view [RGV], and carpal shoot through [CST] view), three-dimensional (3D) and rotational fluoroscopies, and ultrasound (US). For detection of dorsal screw penetration, additional fluoroscopic views show better results than conventional views. Based on small (pilot) studies, US seems to be promising. For intra-articular screw placement, 3D or 360 degrees fluoroscopy shows better result than conventional views. Conclusion  Based on this systematic review, the authors recommend the use of at least one of the following additional imaging modalities to prevent dorsal protruding screws: CST view, DTV, or RGV. Tilt views are recommended for intra-articular assessment. Of all additional fluoroscopic views, the DTV is most studied and proves to be practical and time efficient, with higher efficacy, accuracy, and reliability compared with conventional views. Level of Evidence  The level of evidence is Level III.

How effective is skyline view for avoiding dorsal cortex penetration in volar plate fixation of intra-articular and dorsal cortex comminuted distal radius fractures

OBJECTIVES

The incidence of osteosynthesis is increased by volar anatomic plate used for treatment of distal radius fractures and this increases the incidence of wrist extensor tendon irritation, a postoperative complication of the aforementioned surgical technique. The purpose of this study; was to evaluate the intraoperative skyline view which is commonly used to prevent dorsal cortex penetration of distal screws during the surgical treatment of intra-articular distal radius fractures with comminuted dorsal cortex with CT (computed tomography) scanning to determine its effectiveness. In the literature review, no other study focused on similar fracture types was found.

METHODS

52 patients with a minimum follow-up of 13 months were included in the study. These patients were operated by two different national board certified surgeons. One of the surgeons unlike the other, adopted intraoperative skyline view method. X-ray and CT scans which were performed preoperative and postoperative first day, were evaluated by a senior author with a blind evaluation method. Fractures were classified according to AO/OTA (Orthopaedic Trauma Association) classification and postoperative dorsal cortex penetrations were registered.

RESULTS

Intra-articular distal radius fractures with comminuted dorsal cortex (AO/OTA 2R3C2, C3) were detected in 25 of the patients and no significant difference between two groups for the distribution of these patients was found. The CT scan of 14 patients showed dorsal cortex screw penetration and this rate was significantly higher in the group, in which intraoperative skyline view was not used (p > 0,05). In the postoperative CT examination, the most common dorsal cortex penetration was related to the 4th distal screw (42.9%) which were inserted the nearest ulnar hole of plate.

CONCLUSION

The insertion of a distal screw 2 mm (millimeter) shorter than the length measured with the help of skyline view is considered to be a more effective method than other intraoperative methods for preventing dorsal cortex penetration. In addition, more comprehensive studies are required in order to recommend the mono-cortex fixation, in which distal screws measuring 4 mm shorter are used.

"Island-shape" Fractures of Lister's tubercle have an increased risk of delayed extensor pollicis longus rupture in distal radial fractures: After surgical treatment by volar locking plate

PURPOSE

Weperformed a retrospective case-control study to explore the hypothesis that conditions adjacent to Lister's tubercle (LT) in patients with distal radial fractures (DRFs) exhibiting dorsal comminution would influence the extent of the delayed extensor pollicis longus (EPL) rupture.

METHODS

Among patients treated by volar locking plates (VLPs) were placed between March 2011 and December 2015, 314 met inclusion/exclusion criteria and were analyzed. We designated group 1 as the "EPL rupture" and group 2 as the "no EPL rupture". Basic demographic data, radiological findings, and operative variables were evaluated. The fracture patterns around LT were classified as follows: type I, no fracture line/fragment in LT or the EPL groove (third compartment); type IIA, a fracture of LT or the EPL groove with displacement <2 mm; type IIB, a fracture of LT or the EPL groove with displacement >2 mm; and type III, the presence of an island-shaped fracture fragment of LT (isolated free fragment of LT).

RESULTS

EPL ruptures were found in 18 patients (5.7%). The basic demographic parameters did not differ significantly among the groups. Clinically, neither the time to surgery nor the type of VLP used (of three different types) was not significantly associated with EPL rupture, nor was arthroscopically assisted reduction. In terms of radiological variables, the overall ratio of intra-to-extra-articular fractures did not differ among the groups. However, the fracture type significantly affected the extent of the rupture (P < 0.001), the odds ratio of which increased significantly in the fracture order IIA, IIB, and III, compared to type I (91.9, 220.1, and 342.06, respectively).

CONCLUSIONS

The extent of delayed EPL rupture after treatment of DRFs by VLPs was associated with the fracture pattern around the LT. Especially, an island-shaped LT fracture was associated with a high rupture risk because callus formation narrowed the EPL groove.

LEVEL OF EVIDENCE

Therapeutic Level III.