Prospective investigation of the relationship between dorsal tilt, carpal malalignment, and capitate shift in distal radial fractures

Association of dorsal malunion in distal radius fractures with wrist osteoarthritis: Alterations of bone density and stress-distribution patterns in relation to deformation angles

OBJECTIVE

Distal radius fractures (DRFs) with dorsal malunion increase the risk of osteoarthritis (OA), although the cause of post-DRF OA is yet to be elucidated. To clarify the abnormal effects of a post-DRF dorsal radius deformity, we evaluated the bone density (BD) and stress-distribution patterns of the articular surface in dorsally malunited DRFs.

DESIGN

In 36 cases of dorsally malunited DRFs following extra-articular fractures, we generated three-dimensional computerized models of the malunited distal radius from computed tomography data and extracted the subchondral bones of the radiocarpal joint (RCJ) and distal radioulnar joint (DRUJ). Both BD and stress distribution in the subchondral bones were quantitatively evaluated by comparing the affected and normal sides. Correlations of alterations in high-BD distribution and deformation angles were analyzed.

RESULTS

The center of high-BD distribution from the center of the RCJ in the volar(-)-dorsal(+) direction was dorsal (0.56 ± 0.72 mm) on the affected side compared with the normal side (-0.15 ± 0.63 mm) [95% CI: 0.43, 1.00, P < 0.0001]. The maximum stress distribution was also dorsal on the affected side (2.34 ± 3.52 mm) compared with the normal side (-2.49 ± 1.62 mm) [95% CI: 0.89, 1.79, P < 0.0001]. The alterations in BD and stress distribution correlated with the dorsiflexion and radial deviation angles. In the DRUJ, there was no significant difference in BD between the affected and normal sides.

CONCLUSIONS

In dorsally malunited DRFs, the alignment change of the RCJ resulted in high BD-concentration areas and stress distribution on the dorsal side of the radius, which may constitute a precursor for OA.

Small volar fragment in the lunate fossa leads to volar tilt loss after volar plate fixation for AO/OTA type-C distal radius fracture

OBJECTIVES

The relationship between volar fragment size and postoperative volar tilt loss in complete articular distal radius fracture is not well known. In this study, we measured precise radiological parameters to help identify other factors that might contribute to volar tilt loss.

MATERIAL AND METHODS

We retrospectively reviewed the radiological examinations and charts of 256 patients with distal radial fracture who underwent volar locking plate fixation between March 2014 and July 2022. Radiological parameters were measured based on preoperative CT and immediate postoperative radiographs. Univariate and multivariate linear regression analysis was performed to identify relevant factors associated with volar tilt loss following volar locking plate fixation. The receiver operating characteristic curve was used to identify the cutoff value of the independent parameters.

RESULTS

On univariate analysis, 2 radiologic parameters on preoperative CT (volar fragment length at the lunate fossa, and teardrop angle) and 4 on immediate postoperative X-ray (radial inclination, radial length, capitate shift, and volar tilt) were significantly associated with postoperative volar tilt loss. On multivariate linear regression analysis, the risk of volar tilt loss increased as the capitate moved toward the back of the radial shaft. The cut-off for anteroposterior length in the lunate fossa was 6.5 mm.

CONCLUSIONS

AO/OTA type-C distal radius fractures with <6.5 mm anteroposterior length in the lunate fossa had significantly higher rates of malunion with dorsal deformity. In addition, preoperative teardrop angle <37.2 ° and immediate postoperative volar tilt <3.7º are also predictors of postoperative volar tilt loss.

Change in capitate shift after osteotomy for distal radial fracture malunion

Loss of anterior tilt after a distal radial fracture can lead to carpal malalignment, which may cause functional impairment. The aim of this study was to establish whether distal radial osteotomy for malunion, which primarily restores the dorsal tilt, will also improve carpal malalignment as measured by capitate shift. Radiographs of 67 patients who underwent osteotomy after malunion of a distal radial fracture were reviewed. Measurements of capitate shift and dorsal tilt were recorded. Linear regression modelling was used to assess the relationship between dorsal tilt and capitate shift. Change in capitate shift was strongly associated with change in dorsal tilt following osteotomy. This relationship was maintained on long-term radiographs. Capitate shift is strongly related to dorsal tilt following a distal radial fracture. Correcting the dorsal tilt during an osteotomy, therefore, will improve capitate shift and carpal malalignment. Capitate shift is unrelated to age, sex and is easy to visually assess.Level of evidence: IV.

Association Between Radiographic and Clinical Outcomes Following Distal Radial Fractures: A Prospective Cohort Study with 1-Year Follow-up in 366 Patients

BACKGROUND

Several studies of distal radial fractures have investigated final displacement and its association with clinical outcomes. There is still no consensus on the importance of radiographic outcomes, and published studies have not used the same criteria for acceptable alignment. Previous reports have involved the use of linear or dichotomized analyses.

METHODS

The present study included 438 patients who were managed with either reduction and cast immobilization or surgery for the treatment of distal radial fractures. Radiographic outcomes were determined on the basis of radiographs that were made 3 months after the injury. Clinical outcome was determined on the basis of the QuickDASH (an abbreviated version of the Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire) score, range of motion, and grip strength at 1 year after the injury. Nonlinear relations were analyzed with cubic splines.

RESULTS

Three hundred and sixty-six patients (84%) had both radiographic and clinical follow-up. Seventy patients were lost to follow-up. The mean age was 57 years (range, 18 to 75 years), and 79% of the patients were female. Dorsal tilt was the radiographic parameter that was most strongly associated with the QuickDASH score, grip strength, and range of motion. We found nonlinear relations. Clinical outcomes were found to worsen with increasing dorsal tilt, with the cutoff value being approximately 5°.

CONCLUSIONS

We found that clinical outcomes following distal radial fractures have a nonlinear relationship with dorsal tilt, with worse outcomes being associated with increasing dorsal tilt. The decline in clinical outcome starts at 5°, but there is unlikely to be a noticeable difference in capability as measured with the QuickDASH until 20° of dorsal tilt (based on the minimum clinically important difference) in a population up to 75 years old.

LEVEL OF EVIDENCE

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

Is Capitate Shift Reliable as a Single Indicator for Failure of Non-operative Management in Distal Radius Fractures?

Background Distal radius fractures (DRFs) are the most commonly treated fracture; however, their treatment remains controversial. There is significant variation in the rate of surgical intervention related to a lack of consensus regarding the displacement threshold for surgery. Although studies have advocated that carpal malalignment is the most important radiographic parameter for surgical correction, it is rarely considered in general clinical practice and remains poorly studied. Recently, capitate shift was identified as the most useful measure of carpal malalignment, and a capitate shift threshold of -5.98 mm was proposed to indicate surgical intervention. This study aimed to investigate if this threshold is associated with the failure of non-operatively managed DRFs and should be used as a threshold for primary surgical intervention. Methodology A retrospective analysis was performed of all adult patients who underwent closed manipulation and cast immobilisation for DRFs in a UK district general hospital between September 2021 and February 2022. Capitate shift was measured on initial post-casting radiographs using the validated capitate-to-axis-of-radius distance (CARD) by a junior surgeon. The outcome measure was the failure of conservative management, which was defined as the need for repeat intervention (i.e., cast reapplication or surgical fixation) following closed reduction and cast immobilisation. Results A total of 64 patients with 65 DRFs (16 (25%) male, 49 (75%) female) were included in the study. The mean age was 66.6 years (SD = 17.9, 95% CI = 62.2 to 70.9). The mean capitate shift was -1.51 mm (SD = 5.05, 95% CI = -0.28 to -2.73) in all cases (n = 65). The failure rate of DRFs with an 'unacceptable' capitate shift (i.e., equal or less than -5.98 mm) compared to those with an 'acceptable' capitate shift (i.e., greater than -5.98 mm) was 16.7% versus 3.8% (p = 0.09). Conclusions The study concluded that there was no significant association between a capitate shift threshold of -5.98 mm and failure of non-operatively managed DRFs. Given the ease of use and reliability of capitate shift, we advocate for multicentre large cohort studies to identify a threshold for surgical intervention and establish its association with functional outcomes.

Does the pronator-sparing approach improve functional outcome, compared to a standard volar approach, in volar plating of distal radius fractures? A prospective, randomized controlled trial

BACKGROUND

This study aimed to compare functional outcomes of a volar plate osteosynthesis for distal radius fractures (DRF) performed with either a standard volar approach (SVA), which required detachment of the pronator quadratus muscle, or a pronator-sparing approach (PqSA).

MATERIALS AND METHODS

This prospective randomized controlled study included 106 patients scheduled for volar plate osteosyntheses. Patients were allocated to either the SVA group (n = 53) or the PqSA group (n = 53). Patients were blinded to treatment until completion of the study. The primary outcome measure was the Patient-Rated Wrist Evaluation (PRWE). Secondary outcome parameters were the Disabilities of the Arm, Shoulder, and Hand (DASH) score and the Modified Mayo Wrist Score (MMWS). Follow-up examinations were performed at 8 weeks and 3, 6, and 12 months postoperatively.

RESULTS

Overall, 91 patients were included in the final analysis: 48 in the SVA group and 43 in the PqSA group. The two cohorts were not significantly different in demographic characteristics, including age, sex, injuries on the dominant side, type of injury, and fracture classification. We found significant differences between groups at 6 months in the mean PRWE (SVA: 12.3 ± 10.4, PqSA: 18.9 ± 14.11 points) and in the mean DASH score (SVA: 12.3 ± 11.9, PqSA: 19.3 ± 16.7 points), which favoured the SVA. We found no significant differences between groups in the MMWS or in the PRWE and DASH scores at any other time points.

CONCLUSIONS

This randomized comparative clinical trial failed to demonstrate that a volar plate osteosynthesis performed with a PqSA could improve the outcome, compared to the SVA, in patients with DRF.

LEVEL OF EVIDENCE

II Trial registration Comparison of Two Volar Plating Systems for Distal Radius Fractures, ClinicalTrials.gov (NCT03474445), registered 22 March 2018, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03474445?cond=radius&cntry=AT&draw=2&rank=1.

Ulnar variance in distal radial fractures: assessment and interpretation

We explored patterns of shortening of the distal radius and investigated the effect of displacement on 'ulnar variance' in 250 patients with distal radial fractures. A small number of patients (5%) had a fracture that resulted in true shortening. Thirty-two per cent had fractures that appeared short, but lateral radiographs revealed that the articular surface was tilted, with either the anterior or dorsal rim of the articular surface being proximal to the distal ulna but the other rim was distal to it. We recommend initial assessment of variance on lateral radiographs. If the anterior and dorsal rims of the distal radial articular surface are proximal to the distal ulna, then true shortening is present and lengthening and stabilization, to hold the radius distracted, should be considered. If only one rim is proximal to the distal ulna, then correction of the tilt will lessen the apparent positive variance.Level of evidence: IV.

Scaphoid alignment in dorsally displaced distal radial fracture: a radiographic study

We aimed to establish if fracture reduction will correct scapholunate angle in dorsally displaced distal radial fractures and to identify the relationship with other measures of distal radial position and carpal alignment. Radiographs of 131 patients with a distal radial fracture and of 50 patients with normal radiographs were reviewed. We measured the scapholunate, radiolunate, capitolunate and metacarporadial angles on the lateral views. Linear regression modelling showed that all parameters measured were significantly associated with scapholunate angle on the first radiograph following injury. Scapholunate angle increased following distal radial fracture. Reduction of the fracture improved scapholunate angle, and this was most strongly related to change in dorsal tilt. We conclude that scaphoid flexion is likely to compensate for the dorsal tilt of the lunate as an attempt to counter its dorsal tilt, and to stabilize the wrist to maintain hand function.Level of evidence: IV.