Efficacy of non-bridging external fixation in treating distal radius fractures

How Are Radial Height and Radial Shortening Defined in the Treatment of Distal Radius Fractures? A Critical Review

BACKGROUND

Radial height is a radiographic parameter used to guide the treatment of distal radius fractures. However, it is often used synonymously with other terms, and there are substantial discrepancies in its measurement/definition. These discrepancies can alter the measurement of radial height and affect treatment decisions. The purpose of this review is to identify the different definitions of radial height in the literature relevant to distal radius fractures.

METHODS

A literature review was conducted in the PubMed/MEDLINE database from inception to 2022. Full-length, English-language studies that pertained to distal radius fractures and reported radial height as a recorded measurement were included. The method of radial height measurement (definition) was extracted from included studies. Level of evidence was determined by the Oxford Centre for Evidence-based Medicine Levels of Evidence tool.

RESULTS

A total of 385 studies were identified. Of these, 183 (47.5%) did not provide a definition for radial height. Of the studies that defined radial height, 50.9% (103/202) measured radial height from the radial styloid to the distal ulna, 10.9% (22/202) measured from the radial styloid to the distal radius, and 29.2% (59/202) were "other" definitions.

CONCLUSIONS

There is substantial discrepancy in the way that radial height is measured and reported. We advocate for a standardized measurement of radial height (synonymous with radial length) from the radial styloid to the distal ulnar articular surface. Radial shortening is a different measurement and requires comparison with a reference value.

The Role of External Fixation in the Treatment of Distal Radius Fractures

There are numerous internal fixation (IF) options available for distal radius fractures (DRFs). The choice of fixation method depends on factors such as fracture morphology, soft tissue integrity, the patient's clinical status, and the surgeon's training. While volar plate fixation has become the primary approach for addressing these fractures, alternative IF methods like K-wire fixation, fragment-specific fixation, and dorsal bridge plating continue to be effective. Despite the versatility of IF, there are certain clinical situations where prompt and conclusive management through open reduction and internal fixation (ORIF) is not suitable. These instances include the treatment of polytraumatized patients, individuals with compromised soft tissues, or those medically unstable to tolerate lengthy anesthesia. In such cases, proficiency in closed reduction and external fixation (EF) proves invaluable. Being able to identify these clinical scenarios and comprehend the efficacy and safety of EF in addressing DRFs is valuable for any surgeon handling such injuries.

Development of a testing device for external wrist bridging dynamic fixators used for distal radius fractures

BACKGROUND

Stabilization of extra-articular distal radius fractures by wrist joint bridging (WB) dynamic fixation allows for early motion of the wrist, but relies on exact positioning of the device. In fact, physiological movement appeared to be compromised with even distinctly aberrant positioning of such device. To investigate this issue in more detail, we developed an in-vitro testing apparatus suitable for assessing the forces required for flexion and extension of the wrist.

METHODS

The experimental set-up enables the transmission of the translational movement of the traverse of a universal testing machine into the main physiological movement (flexion and extension) of the wrist. An external WB dynamic fixator was assembled to an artificial saw bone wrist model prior and after performing a wedge-shaped osteotomy on the distal radius about 1.5 cm proximal to the joint line, i.e. generation of a fracture model. The functionality of the fixator was evaluated under either condition and the effect of misalignment of the external WB dynamic fixator was quantified by purposeful violation of the manufacture's instructions. Results were statistically analyzed using the generalized linear mixed model.

FINDINGS

Significantly higher loading was noted as the degree of misalignment increased. The normalized force was significantly higher at a misalignment of 20° compared to 10° (10°: 4.13; 20°: 6.93, P < 0.001).

INTERPRETATION

The proposed set-up turned out to allow highly reproducible and sensitive recording of the reaction forces during flexion and extension of the wrist and thus is feasible for the evaluation and comparison of different external WB devices.

Treatment of Distal Radius Fractures with Bridging External Fixator with Optional Percutaneous K-Wires: What Are the Right Indications for Patient Age, Gender, Dominant Limb and Injury Pattern?

The aim of this retrospective study was to evaluate the medium-term clinical and functional outcomes of patients with closed, displaced, and unstable, simple or complex, intra- and extra-articular distal radius fractures (DRFs) treated with a bridging external fixator (BEF) and optional K-wires (KWs). AO classification was used to differentiate the injuries radiographically. Clinical-functional outcomes were evaluated using the Patient-Rated Wrist and Hand Evaluation Score (PRWHE Score) and the Quick Disabilities of the Arm Shoulder and Hand Score (QuickDASH). A total of 269 dorsally displaced fractures of 202 female (75%) and 67 male subjects (25%) were included, with a mean follow-up of 58.0 months. Seventy-five patients (28%) were treated by additional KWs. No differences were found comparing the two groups of patients (BEF vs. BEF + KWs) regarding age, sex, and fracture side (dominant vs. non-dominant). PRWHE and QuickDASH scores were lower in the BEF + KWs group compared to the BEF group (p < 0.0001 and p = 0.0007, respectively). Thus, patients treated with KWs had a better clinical outcome. Beta multivariate regression analysis confirmed that patients of the BEF + KWs group exhibited a better PRWHE score but not a better QuickDASH score. Patients treated by the BEF + KWs with the fracture on the dominant site were characterised by better clinical outcomes. Older patients had a better PRWHE score independently from the treatment. Our findings suggest that the use of BEF for DRFs with optional KWs can be indicated in both young and elderly patients of any gender, independent of limb side and fracture pattern. As the best functional results were achieved in the elderly when KWs were added, the combination of BEF and KWs seems to be mainly indicated for the treatment of DRF, also complex, in the elderly population.