Fixation of distal ulna fractures associated with distal radius fractures using intrafocal pin plate

Comparison of a 2.7-mm and 3.5-mm locking compression plate for ulnar fractures: a biomechanical evaluation

Objectives

Implant prominence after ulnar fracture fixation may be mitigated by the use of lower profile plates. The biomechanical strength and stability of 2.7-mm and 3.5-mm locking compression plates for fixation were compared.

Methods

Two fracture conditions, transverse (N = 10) and oblique (N = 10), were evaluated in an in vitro study. Half of the specimens for each condition were fixed with 2.7-mm plates and the other half with 3.5-mm plates, all fixed with conventional dynamic compression mechanisms. Specimens were loaded under ±2 Nm of cyclic axial torsion, then under 10 Nm of cyclic cantilever bending, and bending to failure. Interfragmentary motion and strain were analyzed to determine construct stability as a function of fracture pattern and plate size.

Results

Interfragmentary motion was significantly larger in all constructs fixed with 2.7-mm plates, compared with 3.5-mm plates (P < 0.01). The 2.7-mm constructs with transverse fractures had the greatest motion, ranging between 5° and 10° under axial rotation and 5.0-6.0 mm under bending. Motions were the lowest for 3.5-mm constructs with oblique fractures, ranging between 3.2 and 4.2 mm under bending and 2°-3.5° for axial rotation. For oblique fractures, the bending moment at ultimate failure was 31.4 ± 3.6 Nm for the 2.7-mm constructs and 10.0 ± 1.9 Nm for 3.5-mm constructs (P < 0.01). Similarly, for transverse fractures, the bending moment was 17.9 ± 4.0 Nm for the 2.7-mm constructs and 9.7 ± 1.3 Nm for the 3.5-mm constructs (P < 0.01).

Conclusions

Although 3.5-mm plates were more effective at reducing fracture motion, they were consistently associated with refracture at the distal-most screw hole under load to failure. By contrast, 2.7-mm plates plastically deformed despite excessive loads, potentially avoiding a subsequent fracture.

Level of Evidence

Level V.

The distal radioulnar joint after distal radial fractures: when and how do we need to treat pain, stiffness or instability?

The importance of distal radioulnar joint problems associated with distal radial fractures is recognized increasingly. But there remains considerable disagreement about how to treat these problems both acutely and chronically. This review outlines the knowledge about the natural history of ulnar-sided wrist problems with distal radials fractures. In particular, the recent increased understanding of the almost inevitable joint instability associated with distal radial fractures is highlighted, including the unreliability of clinical assessment and hence why there has been so much misunderstanding. Provided there is reasonable bony alignment, most ulnar-sided wrist problems can be treated non-operatively initially (typically for over a year) in anticipation of substantial improvement with time. The exception is early marked subluxation of the distal radioulnar joint (DRUJ) blocking forearm rotation, which needs urgent (typically closed) reduction.

Ulna hook plate osteosynthesis for ulna head fracture associated with distal radius fracture

Background

Distal ulna head or neck fracture is commonly associated with distal radius fracture. Treatment of these fractures remains controversial. Plate osteosynthesis is commonly performed. The purpose of this study was to observe clinical and radiological outcomes in ulna hook plate osteosynthesis for distal ulna fracture associated with distal radius fracture.

Materials and methods

This retrospective study between 2010 and 2018 included patients presenting combined displaced distal ulna fracture and distal radius fracture who were treated with ulna hook plate osteosynthesis. Patient evaluation included pain measurement with the visual analog scale, wrist range of motion, grip and pinch strengths, Quick Disabilities of the Arm, Shoulder and Hand (Q-DASH) score, and Mayo wrist score. Preoperative radiographs were reviewed to classify the distal ulna fracture according to Biyani. Bone union was evaluated on postoperative X-rays. At final follow-up, the usual radiographic parameters were measured and distal radioulnar joint (DRUJ) osteoarthritis was assessed.

Results

A total of 48 patients were included. Mean age was 63 years old and mean follow-up was 28 months. According to the Biyani classification, there were 12 type I, 4 type II, 8 type III, and 24 type IV distal ulna fractures. Wrist flexion was 60°, extension 57°, pronation 85°, and supination 80°. Grip strength was 21 kg (86% of the uninjured opposite side). Pinch strength was 6.6 kg (92% of the uninjured opposite side). Clinical scores were very good to excellent, with a mean Q-DASH of 12 and a Mayo wrist score of 90. Discomfort or pain due to the implant that required implant removal was reported in 29%, and was higher in younger patients. Nonunion was observed in two cases and secondary implant displacement in one case. These three cases required secondary intervention with ulna head resection, which was higher in Biyani type IV. DRUJ osteoarthritis was observed in 12 patients (31%) and was higher in older patients.

Conclusions

Ulna hook plate fixation gives good clinical results and a high rate of fracture union, but complications are common. Implant irritation is a frequent complication, especially in young patients, and often requires implant removal.

Level of evidence: IV

Does Simultaneous Fixation of Both Distal Radius and Distal Ulnar Fractures Improve Outcomes? A Retrospective Cohort Study

Introduction: Distal metaphyseal ulnar fractures are often found in conjunction with distal radius fractures. However, there is no consensus on optimal management. The purpose of this study was to determine whether simultaneous fixation of both distal radius and distal ulnar fractures would improve outcomes. Materials and Methods: Patients treated for distal radial fractures over a 4-year period at our trauma center were identified, and their medical records were analyzed. Twenty-three patients met the inclusion criteria for this study. All radius fractures were fixed using a volar locking plate. Fourteen ulnar fractures were treated with surgical fixation, and nine were treated conservatively. Data were collected on patient demographics, mechanism of injury, whether it was a closed or open fracture, Gustilo classification, AO/OTA classification, immobilization period, follow-up period, and type of treatment. Physical findings comprising the active range of motion and grip strength and radiological findings, including the ulnar variance compared to the healthy side and bone union, were evaluated. Clinical outcomes were assessed using the quick Disabilities of the Arm, Shoulder, and Hand scores. Results: There was no significant difference between the groups in the quick Disabilities of the Arm, Shoulder, and Hand scores, but the arc of dorsi-palmar flexion was more restricted in the operative group than in the conservative group. Other results were not significantly different between the two groups. Discussion: Fixation of distal metaphyseal ulnar fractures can be challenging, and several studies have shown the validity of conservative treatments. This supports the view that if the distal radius fracture is anatomically and rigidly fixed, distal metaphyseal ulnar fractures can be successfully managed conservatively. Conclusion: Our results did not show any merit in the simultaneous fixation of both distal radius and distal ulnar fractures. Thus, needless surgery should be avoided.

Finite element analysis of different locking plate fixation methods for the treatment of ulnar head fracture

Background

Ulnar head fractures are increasingly higher with the growing proportion of the elderly people. Failure to achieve a stable anatomic reduction of ulna head fracture may lead to a distal radioulnar joint (DRUJ) dysfunction and nonunion of the distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. Hence, the purpose of this study is to use finite element analysis to explain the advantages and disadvantages of ulnar-side locking plate fixation compared with dorsal-side locking plate fixation and its screw arrangement in the treatment of ulnar head fractures.

Methods

FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. 20 N axial compression, 50 N axial compression, 1 N∙m torsion moment, 1 N∙m lateral bending moments, and 1 N∙m extension bending moments. Under these conditions, values of the von Mises stress (VMS) distribution of the implant, peak VMS, the relative displacement of the head and shaft fragments between the fracture ends and the displacement and its direction of the models were investigated.

Results

The stress values of ulnar-side plates were lower than those of dorsal-side plates. And the ulnar-plate fixation system also has smaller maximum displacement and relative displacement. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw.

Conclusions

In conclusion, our study indicated that ulnar-side locking plates resulted in a lower stress distribution in the plate and better stability than dorsal-side locking plates for ulnar head fracture fixation. Adding an additional screw to the ulnar head could increase the stability of the fixation system and provide an anti-torsion function. This study requires clinical confirmation of its practicality in the treatment of ulnar head fractures. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

Image classification for Die-punch fracture of intermediate column of the distal radius

OBJECTIVE

The aim of the study was to analyze the imaging findings of Die-punch fracture of intermediate column of the distal radius, and to explore the clinical application value of image classification.

METHODS

The clinical data of 45 patients who were admitted to our hospital from May 2010 to October 2016 were analyzed retrospectively. All patients met the inclusion criteria for Die-punch fracture. X-ray and CT scan were performed to examine the fracture, and the results were assessed by two doctors in a double blind method. Finally, the image classification of Die-punch fracture was formulated.

RESULTS

According to the imaging features of Die-punch fracture, it was divided into four types: type I (dorsal type, 15 cases), type II (volar type, 8 cases), type III (splitting type, 10 cases), type IV (collapsed type, 12 cases). The accuracy rate of CT was 100% (45/45). The misclassification rate of X-ray was 15.6% (7/45) and the missed diagnosis rate was 11.1% (5/45).

CONCLUSIONS

CT examination could accurately diagnose Die-punch fracture and perform preoperative image classification.