Abstract
Four-dimensional computed tomography (4DCT) allows for the assessment of the wrist contact mechanics and kinematics during motion. The purpose of this study was to employ 4DCT to measure the differences in joint surface area (JSA) (3D joint space) at the radioscaphoid, radiolunate, and distal radioulnar joints between a cohort of participants with a distal radius fracture (DRF) and an age-matched cohort of healthy participants. Our results indicated that following a DRF, there was a 20% decrease in JSA at the DRUJ when compared to the healthy (control) cohort. This study demonstrated the use of a non-invasive tool to examine wrist contact mechanics.
Keywords: Wrist fracture, X-ray computed tomography, Outcome measure, Degenerative disease
1. Introduction
Distal radius fractures (DRF) are common orthopedic injuries accounting up to 18% of fractures in the elderly population.1 The incidence of DRFs are expected to increase as the overall population ages and as the life expectancy continues to increase.2 Complications arising from DRFs occur in nearly 35% of patients and are a consequence of either the initial injury or subsequent treatment.3 One of the major complication following closed reduction and casting is DRF malunion, which is seen in up to 33% of cases.4 Malunion is examined using radiographs and can present as a combination of distal radial deformities including radial shortening, dorsal tilt, loss of radial inclination, and/or rotational deformity.5 The long-term consequences of malunion are poorly understood and controversial. Some studies have shown no correlation between anatomically reduced fractures (according to standard radiographic measures such as radial height, radial inclination, and volar tilt) and good functional outcomes or increased patient satisfaction.6,7 While other studies have indicated that radiographic measurements do correlate with functional outcomes.8,9 Challenges in interpreting two-dimensional (2D) static images may contribute to the inconclusive nature of correlating radiographic measures with clinical outcomes. Three-dimensional CT (3DCT) can image the joint in three-dimensions 3D, but statically. Previous studies that have employed this imaging tool to examine the consequence of wrist fractures on joint contact mechanics at the distal radioulnar joint (DRUJ) but were limited to a small case series and short follow-up times of 1 year or less, which may not capture the 3D degenerative changes that occur over time.10
Four-dimensional computed tomography (4DCT) allows 3D volume sequences to be acquired over time while the wrist is in motion.11 Zhao et al. validated the 4DCT technique using the bead-based and bone-based registrations and found the accuracy to be consistent with other static and dynamic image-based kinematic techniques.11 Using 4DCT, we are now able to detect dynamic instabilities that only occur during motion. Therefore, the purpose of this study was to employ a previously developed joint congruency algorithm to determine if there are differences in 3D joint space following a DRF compared to a healthy cohort using a 4DCT approach. Specifically, our first objective was to measure the differences in joint surface area (JSA) (3D joint space) at the DRUJ and radiocarpal joints between a cohort of participants with a DRF and an age-matched cohort of healthy participants. Our second objective was to determine if there were differences in the JSA at different wrist positions (extension and flexion) in the healthy cohort and to determine if these trends were also reflected in the DRF cohort. Our hypothesis was that the measured JSA would decrease following a DRF corresponding to an increase in patient-reported pain and disability, degenerative scores and a decrease in wrist function. We also hypothesized that JSA would vary as a function of position in the radiocarpal joints across extension-flexion, but not in the DRUJ which is largely responsible for pronation-supination.
2. Materials and methods
2.1. Participants
Individuals with a previous DRF treated at a specialized hand and upper extremity centre were identified. These cases were reviewed and subjects meeting the eligibility criteria were contacted to participate in the study. The inclusion criteria were as follows: a healed DRF, a minimum of one-year post-fracture, and the ability to participate in a clinical follow-up visit. The exclusion criteria included 18 years of age or younger at the time of injury, a concomitant injury to the ipsilateral hand or wrist, presence of metal pins/plates, and having a neurological disorder that affected hand function. Seventeen participants were identified and consented to undergo CT imaging and functional testing in addition to completing patient-reported pain and disability questionnaires. Of this group, 14 presented for CT testing, while 3 cancelled their appointments or failed to present. Healthy individuals with no previous wrist fractures in a similar age range were also recruited to participate in the study. These cases were reviewed, and subjects were age-matched to the 11 individuals with a DRF (age matching range is age ± 5 years). Overall, 22 participants (11 individuals with distal radius fractures and 11 healthy controls) were included in this study. Participants were seen for a follow-up assessment by a fellowship-trained Orthopaedic hand surgeon (N.S) at the institution. The study protocol was approved by the ethics review board of the institute and hospital and complied with the Declaration of Helsinki of 1975, revised 2000.
2.2. 4DCT imaging
A CT scanner (Revolution CT Scanner, GE Healthcare, Waukesha, Wisconsin, USA) was used to acquire kinematic scans of the distal forearm and hand using a routine wrist scan protocol (80 kV, 125 effective mA, 0.35 s rotation time, axial). The CT scanner imaged a 16 cm volume, configured as 128, 1.25 mm thick slices, repeatedly at 0.35 s intervals over a duration of 24.5 seconds for a total of 70 vol at 2.86 Hz. The voxel size was 0.625 × 0.625 × 1.25 mm. For the purposes of this study, three passes of flexion-extension were performed (terminal extension to terminal flexion was the first pass (25 vol, 8.75 s), terminal flexion to terminal extension was the second pass (25 vol, 8.75 s), and terminal extension to terminal flexion was the third pass (20 vol, 7.0 s), resulting in a total time of 24.5 s per motion and 25 frames of motion per pass. Three passes of motion were obtained to ensure the total range of motion (ROM) was captured if the participant moved too slowly or if they missed the trigger to begin motion at the start of the scan. The first instance of terminal extension-flexion was analyzed in this study. In addition to these kinematic scans, a static scan with the wrist in 30° of supination was acquired (0.35 × 0.35 × 0.625 mm for the scan, 125 mA, 120 kVp). The speed of the scan was approximately 22°/s for extension/flexion. During imaging, the individuals were lying in prone with their arm outstretched inside of the scanner. The total skin dose is 0.2 Gy from the wrist scans.
2.3. Image analysis
In this study, three static phases of the extension/flexion motion were of interest. The 3DSlicer software (version 4.11.0) was used to visualize the frames of data. The three static phases of the extension-flexion motion examined were terminal extension, neutral, and terminal flexion. We analyzed the end states of the extension-flexion motion since previous studies suggested carpal ligaments are more prone to strain and injuries when the wrist is fully extended or flexed.12
The DICOM images (Digital Imaging and Communications in Medicine) obtained from the CT scan were imported into Mimics 21.0 (Materialise, Leuven, Belgium). Three-dimensional reconstructions of the carpus, ulna, and radius were created using a semi-automatic threshold-based segmentation technique to reconstruct the outer most bony surface. A previously developed inter-bone distance algorithm was used to measure relative 3D surface area (JSA) (mm2).13 Briefly, the algorithm calculates minimum inter-bone distances between opposing bone surfaces using a point-to-point distance measurement. Inter-bone distances are displayed using colored proximity maps (0 mm = red, 2 mm = blue). A threshold value of 2.0 mm was selected because it approximately captured the entire articular surface of the joints surrounding the scaphoid and has been previously used to measure articular cartilage in the scaphoid and lunate fossae and along the interfossal ridge. The JSA was defined as the area on the surface of the scaphoid facet that is within 2.0 mm of the opposing surface for the radioscaphoid, radiolunate, and distal radioulnar joints. The JSA was normalized to the individual's total static JSA of the radiocarpal joint articular surface and sigmoid notch of the distal radius. The mean JSA (%) for the healthy and DRF cohorts were reported. The effect of fracture and the effect of the ROM on measured mean percent JSA (inter-bone distances less than 2.0 mm) was examined.
2.4. Radiographic evaluation
Follow-up radiographs (posteroanterior and lateral views) were obtained from each participant in the DRF cohort (follow-up mean: 5 months, range: 3–10 months). Radiographs were used to measure the radial inclination (RI), dorsal angulation (DA), and ulnar variance (volar +, dorsal -) (UV). All measurements were performed by an Orthopedic hand surgery fellow (Y.Z). Overall, the distal radius alignment was determined to be unacceptable if RI < 15°, if DA >10°, or if there was ≥3 mm of UV positive using the guidelines written by the American Society for Surgery of the Hand and used by previous studies.6 Additionally, the follow-up radiographs were classified using the Müller AO classification system.
Evidence of degenerative changes in the radioscaphoid, radiolunate, and DRUJ were assessed by grading the follow-up CT images using the Kellgren and Lawrence (KL) grading scale: 0- None, 1- Doubtful, 2- Minimal, 3- Moderate, 4- Severe.14 Grades were based on the presence of joint space narrowing, osteophytes, sclerosis, and deformity of bone ends.14 The follow-up CT images (coronal views) obtained from each participant in the DRF and healthy cohorts were used to assign KL grades by an Orthopedic hand surgery fellow (M.M.), and to predict long-term degenerative changes (as defined by a grade of greater than 2 on the KL grading scale).
2.5. Functional assessments
After CT scanning, participants in the DRF and healthy cohorts underwent functional tests to examine their grip strength, ROM, and patient-reported pain and disability. The grip strength was recorded using a hand dynamometer. Joint angles across the ROM at the three positions: terminal extension, neutral and terminal flexion were recorded using a goniometer. Lastly, patient-reported pain and disability was quantified using a 15-item Patient-Rated Wrist Evaluation (PRWE) questionnaire which was shown to be a reliable method for individuals who have sustained a DRF injury.
2.6. Statistical analysis
To detect differences in the mean JSA % between health status and joint position, a two-way univariate analysis of variance was conducted (IMB SPSS Statistics software version 25) for each joint of interest (p-value = 0.05 was considered significant). This test examined the interaction between the independent variables of health status (uninjured and injured) and joint positions (terminal flexion, neutral and terminal extension) to the dependent variable of the percent mean JSA at each inter-bone distances (0 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm). To compare the clinical outcomes between the healthy and DRF cohorts, a paired t-test analysis was conducted for grip strength, ROM (static joint angles), degenerative changes, and PRWE scores.
3. Results
Overall, 22 participants (11 individuals with a DRF and 11 healthy controls) were included in this study. The average age of the DRF cohort was 71 ± 16 years (range:60–84 years) with a mean follow-up time of 12 ± 13 years (range:1–47 years) (Table 1). The mean age of the healthy (control) cohort was 68 ± 9 years (range:60–84 years). The DRF cohort consisted of five extra-articular, four intra-articular and one partial DRF (one participant did not have injury films and the fracture was not classified).
Table 1.
Demographic factors and injury characteristics of participants in the DRF cohort (n = 11) and the age-matched healthy cohort (n = 11).
| DRF Participants |
Healthy Participants |
|||||||
|---|---|---|---|---|---|---|---|---|
| Participant ID | Gender | Age at Injury | Age at Follow-up | Follow-up time (years) | AO Classification | Participant ID | Gender | Age |
| 1A | Female | 65 | 66 | 1 | 2R3A3 | 1B | Female | 61 |
| 2A | Female | 59 | 73 | 2 | 2R3A2 | 2B | Male | 73 |
| 3A | Female | 58 | 61 | 10 | 2R3C2 | 3B | Male | 57 |
| 4A | Female | 76 | 68 | 8 | 2R3A3 | 4B | Male | 71 |
| 5A | Female | 58 | 84 | 2 | 2R3C2 | 5B | Female | 80 |
| 6A | Female | 63 | 60 | 12 | 2R3C3 | 6B | Female | 56 |
| 7A | Female | 64 | 75 | 13 | 2R3C2 | 7B | Female | 73 |
| 8A | Female | 65 | 77 | 15 | 2R3B1 | 8B | Male | 72 |
| 9A | Male | 15 | 80 | 47 | No injury films | 9B | Female | 76 |
| 10A | Female | 67 | 62 | 10 | 2R3A2 | 10B | Female | 57 |
| 11A | Female | 66 | 77 | 7 | 2R3A2 | 11B | Male | 75 |
Fig. 1 shows the changes in percent mean JSA (inter-bone distances less than 2.0 mm) in each joint for the healthy (n = 11) and DRF (n = 11) cohorts at the A) distal radioulnar joint, B) radioscaphoid joint and C) radiolunate joint. There was a significant difference between the healthy and DRF cohorts for the JSA (%) at the DRUJ (p < 0.05). The largest difference between the healthy and DRF cohorts was observed at terminal wrist flexion with a difference of approximately 20% (19.6 mm2). No significant differences were found for the JSA at the radiolunate (p > 0.05) or at the radioscaphoid joint (p > 0.05) between the healthy and DRF cohorts.
Fig. 1.
Changes in percent mean joint surface area (inter-bone distances less than 2.0 mm) in each joint for distal radius fracture (n = 11) and healthy (n = 11) participants. Bars represent mean and error bars represent standard deviation of the sample.
A) Average Joint Surface Area Percentage for Distal Radioulnar Joint in Healthy and Fracture participants
B) Average Joint Surface Area Percentage for Radioscaphoid Joint in Healthy and Fracture participants
C) Average Joint Surface Area Percentage for Radiolunate Joint in Healthy and Fracture participants.
When comparing the JSA between the wrist positions within each cohort (DRF and healthy cohorts), we found a significant difference at the radiolunate joint (p < 0.05) and at the radioscaphoid joint (p < 0.05) in the healthy cohort. We also found that JSA % at the radiolunate and radioscaphoid joint in the healthy cohort significantly decreased approximately 5% and 10%, respectively, in terminal flexion from the neutral position. In the DRF cohort, the difference was only seen at the radioscaphoid joint (p < 0.05).
The KL grades and colormaps for the DRF and healthy cohorts are listed in Table 2 and we found no significant differences in the degenerative changes when comparing the two cohorts. The DRF cohort demonstrated degenerative changes in the DRUJ (n = 6) and radiocarpal joints (n = 10). The healthy cohort also demonstrated degenerative changes in DRUJ (n = 5) and radiocarpal joints (n = 10). Additionally, seven out of the 11 DRF participants were considered to have unacceptable radiographic distal radius alignment (Appendix 1).
Table 2.
Joint congruency maps for the distal radioulnar, radioscaphoid and radiolunate joints during wrist extension-flexion in a cohort of participants with a DRF (n = 11) and age-matched cohort of healthy participants (n = 11).
The individual's grip strength, static extension and flexion angles, and PRWE scores for the age-matched DRF and healthy cohorts are listed in Table 3. There was a significant difference in grip strength between the DRF cohort (mean = 23 Kg) and healthy cohort (mean = 32 Kg) (p < 0.05). The mean joint angles for the DRF cohort was from flexion of 58° (range: 25°–87°) to extension of 63° (range: 50°–86°) and for the healthy cohort was flexion of 65° (range: 32°–85°) to extension of 65° (range: 55°–75°); no significant differences were found at the terminal flexion or at the terminal extension positions (p > 0.05). Three participants in the DRF cohort and two participants in the healthy cohort had a PRWE score greater than 20.
Table 3.
Functional assessments and patient-reported pain and disability of participants in the DRF cohort (n = 11) and the age-matched healthy cohort (n = 11).
Range of motion measurements in the DRF cohort were taken on the injured wrist and were compared to the same side wrist in the healthy cohort.
| DRF Participants |
Healthy Participants |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| ID | Static Extension (°) | Static Flexion (°) | Grip Strength (Kg) | PRWE | ID | Static Extension (°) | Static Flexion (°) | Grip Strength (Kg) | PRWE |
| 1A | 60 | 25 | 14 | 36.5 | 1B | 65 | 80 | 26 | 0 |
| 2A | 50 | 65 | 23 | 10 | 2B | 60 | 70 | 42 | 18 |
| 3A | 50 | 75 | 20 | 5 | 3B | 60 | 70 | 40 | 0 |
| 4A | 70 | 60 | 26 | 26.5 | 4B | 70 | 70 | 43 | 0 |
| 5A | 77 | 55 | 24 | 3 | 5B | 70 | 50 | 19 | 54 |
| 6A | 86 | 66 | 23 | 3.5 | 6B | 75 | 65 | 40 | 0 |
| 7A | 50 | 55 | 28 | 12 | 7B | 55 | 85 | 28 | 0 |
| 8A | 55 | 60 | 30 | 2.5 | 8B | 65 | 75 | 34 | 0 |
| 9A | 55 | 87 | 20 | 0 | 9B | 70 | 70 | 24 | 0 |
| 10A | 60 | 30 | 20 | 0 | 10B | 60 | 50 | 18 | 65 |
| 11A | 75 | 55 | 23 | 41 | 11B | 66 | 32 | 40 | 1 |
| Average | 63 | 58 | 23 | 13 | Average | 65 | 65 | 32 | 13 |
4. Discussion
Our study investigated the use of 4DCT to examine the effect of DRF on JSA at the radioscaphoid, radiolunate, and distal radioulnar joints during wrist flexion and extension. Our first hypothesis was that JSA would decrease following fracture and that there would be an increase in patient-reported pain and disability and a decrease in wrist function. Taken together, we found that following a DRF, there was a 20% decrease in JSA at the DRUJ and a significant decrease in grip strength compared to the healthy cohort. We did not measure any differences in ROM, PRWE or presence of degenerative changes between our two cohorts. This study also demonstrated that joint position affects the JSA at the radioscaphoid and radiolunate joints in the healthy cohort. We did not find similar trends in the DRF cohort and significant differences were found only at the radioscaphoid joint. There was no effect of joint position on the JSA at the DRUJ in either cohorts. This confirmed our second hypothesis that DRFs will alter the mean JSA in the radiocarpal joints at the wrist extension and flexion positions, but not in the DRUJ, which is largely responsible for pronation-supination.
Few studies have investigated the effect of health status on joint congruency following DRFs.10,15 Crisco and colleagues found that the JSA at the DRUJ during forearm rotation significantly decreased by approximately 25% or 56 mm2 in the malunited wrists compared to the contralateral uninjured side.10 Our data followed a similar trend, where JSA at the DRUJ significantly decreased by approximately 20% and 10% at terminal flexion and at terminal extension, respectively, in the DRF cohort compared to the healthy cohort. This previous study only recruited participants with mal-aligned DRFs, examined forearm rotation, and had contralateral wrists as their control group which can explain the larger difference found between the injured and uninjured wrists in their study.10 Recently, our lab examined the effect of DRF on JSA in a cohort of participants who were 8–10 years post-fracture, and found a 20% decrease at the radiolunate joint when the wrist was positioned in static protonation.16
Rainbow and colleagues examined JSA at the radiocarpal and midcarpal joints during extremes of wrist flexion and extension in healthy participants.17 This previous study found the contact areas of the lunate and scaphoid on the radius significantly decreased 39% ± 22% and 66% ± 13%, respectively, when the wrist was in extreme flexion from neutral-grip.17 Additionally, the contact areas of the lunate and scaphoid significantly increased 45% ± 22% and 13% ± 16%, respectively, in extreme extension from neutral-grip.17 This previous study was limited to healthy participants and static positions. Our study also found that JSA at the radiolunate and radioscaphoid joint in the healthy cohort significantly decreased approximately 5% and 10%, respectively, in terminal flexion from the neutral position. Overall, we found significant differences at the radiolunate and radioscaphoid joint in the healthy cohort, when the wrist was fully extended and flexed, indicating that this motion occurs at the radiocarpal joints. We did not find significant differences at the DRUJ at the extension and flexion positions.
The limitations of our study include a small series of participants and the use of a convenience sample (no preference for mild or severe mal-alignment). Having a larger homogenous sample of DRFs with similar unacceptable radiographic parameters may further delineate differences in JSA. It is also important to remember that the JSA metric is not a direct measure of cartilage contact since cartilage is poorly imaged with CT. Perhaps if we had used the contralateral wrist as a control, we may be able to get a more accurate correlation when comparing the JSA and functional outcomes. Unfortunately, this had to be weighed against the increased radiation exposure for the participants. Despite these limitations, our study demonstrated the feasibility of using 4DCT to acquire images and apply a previously developed joint congruency algorithm to non-invasively characterize the effects of a wrist injury on the in vivo wrist biomechanics during active extension-flexion. Future studies need to consider obtaining ROM scans of other wrist injuries and more complex movements that involve multiple planes since wrist movements are rarely planar during activities of daily living.
Declaration of competing interest
None.
Acknowledgements
The authors would like to acknowledge the Bone and Joint Institute who provided funding for this project. Additionally, all authors do not have any professional or financial affiliations that may be perceived to have biased the presentation.
Footnotes
All authors have made substantial contributions to research design, acquisition analysis and interpretation of data. Additionally, all authors have participated in manuscript preparation and approved the final version.
Appendix. 1Radiographic measurements taken at long-term follow-up (mean: 5 months, range: 3–10 months). Radiographic alignment measurements included radial inclination (RI), dorsal angulation (DA), ulnar variance (mm)- measured from the line tangential to the lunate fossa and perpendicular to the radial shaft compared to the line tangential to the distal articular surface of the ulna. Positive variance (+) is when the ulna is longer than the tangential line from the lunate fossa while negative variance (-) is when the ulna is shorter than the tangent (UV). Unacceptable radiographic measurements were RI <15°, DA >10° and UV ≥ 3 mm
| DRF Participant | RI | DA | UV |
|---|---|---|---|
| 1A | 12 | 8.5 | 1 mm+ |
| 2B | 21.9 | 11.2 | 2 mm+ |
| 3A | 20.6 | 30.2 | 4 mm+ |
| 4A | 19.5 | 2.9 volar | 1 mm+ |
| 5A | 23.5 | 14.2 volar | 0 |
| 6A | 26.7 | 5.4 volar | 3 mm + |
| 7A | 27.6 | 25 | 3 mm + |
| 8A | 18 | 4.1 | 0 |
| 9A | 21.3 | 6.3 | 1 mm+ |
| 10A | 17.3 | 25.9 | 6 mm+ |
| 11A | 25 | 3.1 volar | 1 mm+ |
References
- 1.Nellans KW, Kowalski E, Chung KC. The Epidemiology of Distal Radius Fractures. 2012. doi:10.1016/j.hcl.2012.02.001. [DOI] [PMC free article] [PubMed]
- 2.Diaz-Garcia R.J., Oda T., Shauver M.J., Chung K.C. A systematic review of outcomes and complications of treating unstable distal radius fractures in the elderly. J Hand Surg Am. 2011;36(5):824–835. doi: 10.1016/J.JHSA.2011.02.005. e2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Sharma H., Khare G.N., Singh S., Ramaswamy A.G., Kumaraswamy V., Singh A.K. Outcomes and complications of fractures of distal radius (AO type B and C): volar plating versus nonoperative treatment. J Orthop Sci. 2014 doi: 10.1007/s00776-014-0560-0. [DOI] [PubMed] [Google Scholar]
- 4.Cole J.M., Obletz B.E. Comminuted fractures of the distal end of the radius treated by skeletal transfixion in plaster cast. An end-result study of thirty-three cases. J Bone Joint Surg Am. 1966;48(5):931–945. [PubMed] [Google Scholar]
- 5.Lichtman D.M., Bindra R.R., Boyer M.I. Treatment of distal radius fractures. J Am Acad Orthop Surg. 2010 doi: 10.5435/00124635-201003000-00007. [DOI] [PubMed] [Google Scholar]
- 6.Anzarut A., Johnson J.A., Rowe B.H., Lambert R.G.W., Blitz S., Majumdar S.R. Radiologic and patient-reported functional outcomes in an elderly cohort with conservatively treated distal radius fractures. J Hand Surg Am. 2004;29(6):1121–1127. doi: 10.1016/j.jhsa.2004.07.002. [DOI] [PubMed] [Google Scholar]
- 7.Jaremko J.L., Lambert R.G.W., Rowe B.H., Johnson J.A., Majumdar S.R. Do radiographic indices of distal radius fracture reduction predict outcomes in older adults receiving conservative treatment? Clin Radiol. 2007;62(1):65–72. doi: 10.1016/j.crad.2006.08.013. [DOI] [PubMed] [Google Scholar]
- 8.McQueen M., Caspers J. Colles fracture: does the anatomical result affect the final function? J Bone Joint Surg Br. 1988;70(4):649–651. doi: 10.1302/0301-620X.70B4.3403617. http://www.ncbi.nlm.nih.gov/pubmed/3403617 [DOI] [PubMed] [Google Scholar]
- 9.Kodama N., Takemura Y., Ueba H., Imai S., Matsusue Y. Acceptable parameters for alignment of distal radius fracture with conservative treatment in elderly patients. J Orthop Sci. 2014;19(2):292–297. doi: 10.1007/s00776-013-0514-y. [DOI] [PubMed] [Google Scholar]
- 10.Crisco J.J., Moore D.C., Marai G.E. Effects of distal radius malunion on distal radioulnar joint mechanics—an in vivo study. J Orthop Res. 2007;25(4):547–555. doi: 10.1002/jor.20322. [DOI] [PubMed] [Google Scholar]
- 11.Zhao K., Breighner R., Holmes D. A technique for quantifying wrist motion using four-dimensional computed tomography: approach and validation. J Biomech Eng. 2015;137(7) doi: 10.1115/1.4030405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Lee D.J., Elfar J.C. Carpal ligament injuries, pathomechanics, and classification. Hand Clin. 2015;31(3):389–398. doi: 10.1016/j.hcl.2015.04.011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Lalone E.A., McDonald C.P., Ferreira L.M., Peters T.M., King G.W., Johnson J a. Development of an image-based technique to examine joint congruency at the elbow. Comput Methods Biomech Biomed Eng. 2013;16(3):280–290. doi: 10.1080/10255842.2011.617006. [DOI] [PubMed] [Google Scholar]
- 14.Kellgren J.H., Lawrence J.S. Radiological assessment of osteo-arthrosis. Ann Rheum Dis. 1957;16:494–502. doi: 10.1136/ard.16.4.494. 0003-4967 (Print) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Gammon B., Lalone E., Nishiwaki M., Willing R., Johnson J., King G.J.W. Arthrokinematics of the distal radioulnar joint measured using intercartilage distance in an in vitro model. J Hand Surg Am. 2017 doi: 10.1016/j.jhsa.2017.08.010. [DOI] [PubMed] [Google Scholar]
- 16.Lalone E.A., MacDermid J., King G., Grewal R. The effect of distal radius fractures on 3-dimensional joint congruency. J Hand Surg Am. 2020 doi: 10.1016/j.jhsa.2020.05.027. [DOI] [PubMed] [Google Scholar]
- 17.Rainbow M.J., Kamal R.N., Leventhal E. In vivo kinematics of the scaphoid, lunate, capitate, and third metacarpal in extreme wrist flexion and extension. J Hand Surg Am. 2013;38(2):278–288. doi: 10.1016/j.jhsa.2012.10.035. [DOI] [PMC free article] [PubMed] [Google Scholar]