The radiographic measurement of ulnar translation

Assessment of Ulnar Carpal Translocation and Carpal Alignment After Volar Plate Fixation With Vascularized Bone Graft for Scaphoid Waist Fracture Nonunions

PURPOSE

Multiple fixation methods with or without vascularized graft have been described to treat scaphoid nonunions. This study aimed to assess the incidence of carpal malalignment and the degree of ulnar carpal translocation after scaphoid volar plate fixation with pedicled vascularized bone graft in scaphoid waist nonunions with humpback deformity.

METHODS

A retrospective cohort study of individuals with recalcitrant scaphoid fracture nonunion treated with volar scaphoid plating and vascularized bone graft was analyzed. All patients had radiographs with the wrist at neutral with clinical follow-up of at least 3 months after surgery. Ulnar subluxation of the carpus was assessed by the change in lunate uncovering and carpal-radial distance before and after surgery.

RESULTS

Seventeen patients were included for analysis. Average age was 26 years with an average follow-up interval of 11.0 months. After surgery, 16 patients (94.1%) had fracture union. Between preoperative and initial postoperative imaging, there was an increase in lunate uncovering (mean difference: 8.8%; 95% confidence interval, 4.6% to 13.1%) and carpal-radial distance (mean difference: 3.3% ulnar shift; 95% confidence interval, 1.1% to 5.4%). After surgery, there was minimal change in lunate uncovering and carpal-radial distance from immediately after surgery to final follow-up.

CONCLUSIONS

Preoperative lunate uncovering was lower than normal values, suggesting an abnormal radial shift of the carpus with a collapsed scaphoid. Postoperative lunate uncovering was similar to normal values, reflecting an ulnar shift of the carpus after operative intervention.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Ulnar Buttress Arthroplasty without Ulnar Stump Stabilization for Giant Cell Tumor of Distal Ulna

Purpose  Reconstruction and stabilization of ulnar stump after distal ulna tumor resection is still a matter of debate. We present the outcomes of ulnar buttress arthroplasty without stabilization of the ulna stump in giant cell tumor of bone (GCTB) of the distal ulna. Methods  Evaluation of functional outcome was performed using Musculoskeletal Tumor Society 93 (MSTS93) score, Modified Mayo Wrist score (MMWS), and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. We also assessed the hand grip strength, range of motion at the wrist, and ulnar carpal translation. Results  The study included 8 patients with Campanacci grade 3 GCTB of the distal ulna with a mean follow-up of 35.5 ± 9.1 months. The mean resection length was 7.7 ± 1.3 cm. The mean hand grip strength on the operated side was noted to be 90 ± 0.04% of the contralateral side. Mean MSTS93 score was 27.9 ± 1.25, mean MMWS was 86.9 ± 4.58%, and the mean DASH score was 4.9 ± 1.67, depicting a good to excellent functional outcome with low degree of disability. No radiocarpal instability, ulnar carpal translation, prominence, or instability of the proximal ulnar stump was noted in any patient. Conclusion  Reconstruction of the distal radioulnar joint using iliac crest bone graft for ulnar buttress without stabilization of the ulnar stump after resection of the distal ulna is an effective reconstruction option with good functional outcome and preservation of good hand grip strength. Level of Evidence  Level IV, Therapeutic study.

Volar Intra-articular Extended Window Approach for Intra-articular Distal Radius Fractures

Distal radius fractures are one of the most common injuries seen globally with increasing use of use of volar plating for surgical treatment. Although it is common to directly visualize the articular surface for most other periarticular fractures, during volar plating of the distal radius the joint is typically not visualized. This is due to concern for carpal instability from disruption of the volar carpal ligaments. When direct visualization of the articular surface is deemed necessary, either to reduce articular fragments or to confirm the quality of reduction, current options include a separate dorsal arthrotomy or arthroscopic assistance. However, biomechanical evidence supports safely performing a volar capsulotomy to visualize the articular surface. We describe the Volar Intra-Articular Extended Window approach, which allows direct visualization of the articular surface through the volar approach to treat distal radius fractures.

Ligament-Sparing Volar Radiocarpal Arthrotomy During Distal Radius Fracture Repair: Biomechanical Implications on Wrist Stability in a Cadaveric Model

PURPOSE

Distal radius (DR) fracture fixation with volar locked plating typically uses indirect fracture reduction without direct visualization of the articular surface in an attempt to preserve the volar radiocarpal ligaments and prevent iatrogenic radiocarpal instability. This study assessed the biomechanical stability after a volar radiocarpal arthrotomy for direct articular visualization for DR fracture repair compared to a standard trans-flexor carpi radialis approach without arthrotomy in a cadaver model.

METHODS

Ten fresh-frozen upper extremity matched-pair cadaveric specimens were tested. For each pair, one limb underwent trans-FCR approach with a volar arthrotomy that partially sectioned the long and short radiolunate ligaments to visualize the DR articular surface (Group 1). The contralateral limb underwent standard trans-FCR approach without arthrotomy (Group 2). Following capsular repair (Group 1), all specimens (Groups 1 and 2) underwent biomechanical testing, including axial loading (22.2 N, 44.5 N, 89.0 N, 177.9 N), volar translational, and dorsal translation loading (22.2 N, 44.5 N, 89.0 N) to assess carpal stability using both fluoroscopy and motion capture. Ulnar carpal translation was assessed using the Gilula method, measuring radiographic lunate overhang from the ulnar edge of the lunate fossa relative to the full width of the lunate. Dorsal and volar translation were assessed by measuring lunate overhang with respect to the dorsal or volar radial cortex. To simulate fractures with dorsal radiocarpal ligament disruption, the dorsal capsule was sectioned, and the biomechanical comparisons were repeated.

RESULTS

Ulnar translation of the lunate remained below 2 mm for both groups in all testing scenarios. No significant differences were identified in ulnar, volar, or dorsal translation with increasing loads between the groups.

CONCLUSIONS

This volar ligament-sparing radiocarpal arthrotomy did not cause biomechanical radiocarpal instability.

CLINICAL RELEVANCE

This arthrotomy may provide enhanced visualization of the DR articular surface during fracture fixation without causing iatrogenic wrist instability.

Ulnar carpal translation following palmar locking plate fixation for distal radius fractures: a retrospective analysis

BACKGROUND

Concomitant injuries to the radiocarpal ligaments may occur during episodes of distal radius fractures, which may not cause acute subluxation or dislocation but can lead to radiocarpal instability and progress over time. This study aimed to analyze the occurrence of ulnar carpal translation (UCT) after open reduction and internal fixation of distal radius fractures and evaluate the associated factors of UCT.

METHODS

The retrospective study has been done now and includes patients treated between 2010 and 2020 who had undergone reduction and locking plate fixation of distal radius fractures. We assessed radiographs taken immediately after the operation and at 3 months post-operation, enrolling patients with UCT for evaluation. In addition to demographic data, we evaluated radiographic parameters, including fracture pattern, fragment involvement, and ulnar variance. We also assessed the palmar tilt-lunate (PTL) angle to determine associated rotatory palmar subluxation of the lunate (RPSL).

RESULTS

Among the 1,086 wrists, 53 (4.9%) had UCT within 3 months post-operation. The majority of wrists with UCT exhibited normal to minus ulnar variance (49 wrists; mean: -1.1 mm), and 24 patients (45.3%) had concomitant RPSL. Fracture classification was as follows: 19 type A3 (35.8%), 5 type C1 (9.4%), 11 type C2 (20.8%), and 18 type C3 (34.0%). Radial styloid was involved in 20 wrists (37.7%), palmar rim in 18 wrists (34.0%), dorsal rim in 25 wrists (47.2%), and die-punch fractures in 3 wrists (5.7%). Concomitant ulnar styloid fractures were present in 29 wrists (54.7%).

CONCLUSION

This study highlights the potential for UCT to occur following reduction and fixation of distal radius fractures, particularly in cases with a more severe fracture pattern and combined with ulnar minus variance. The high incidence of concomitant RPSL provides further evidence for the possibility of associated radiocarpal ligament insufficiency after distal radius fracture.

The Safety of the Volar Intraarticular Extended Window (VIEW) Approach for Intra-articular Distal Radius Fractures

BACKGROUND

A novel volar approach to intra-articular distal radius fractures has been introduced for treatment of intra-articular distal radius fractures, in which volar extrinsic ligaments are released to create a volar window into the radiocarpal joint (Volar Intraarticular Extended Window [VIEW] approach). Our purpose was to evaluate the safety of VIEW approach for treatment of intra-articular distal radius fractures.

METHODS

A retrospective chart review was performed for 13 patients with intra-articular distal radius fractures treated operatively with the VIEW surgical technique using an intra-articular window in the volar capsule to aid in reduction and fixation. Postoperative radiographs were reviewed to assess for ulnocarpal translocation by assessing lunate uncovering and radial-carpal distance.

RESULTS

Thirteen patients were treated with the VIEW approach with mean follow-up of 28 weeks (range, 7-67 weeks; SD, 18 weeks). The mean postoperative lunate uncovering was 34.6% (SD, 7.7%) and mean radial-carpal distance was 4.6 mm (SD, 1.5 mm). Postoperatively, mean intra-articular step-off was 0.9 mm (SD, 1.2 mm) and mean intra-articular gap was 1.2 mm (SD, 1.0 mm). No patients reported clinical symptoms of wrist instability.

CONCLUSIONS

Using the VIEW approach during a volar approach to intra-articular distal radius fractures is safe and does not lead to carpal instability. Surgeons can consider using the approach when direct visualization of the articular surface may be beneficial for reduction or fixation.

LEVEL OF EVIDENCE

Therapeutic IV.

Bridge plating in the setting of radiocarpal instability: Does distal fixation to the second or third metacarpal matter? A cadaveric study

BACKGROUND

Radiocarpal dislocations are rare but potentially devastating injuries. Poorer outcomes are associated with inadequate or lost reduction, such as ulnar translocation, but no consensus exists on the ideal fixation technique. Dorsal bridge plate fixation has been described for various settings in the treatment of complex distal radius fractures and can be fixed distally to the second or third metacarpal, but its application for radiocarpal dislocations has not been established.

AIM

To determine whether distal fixation to the second or third metacarpal matters.

METHODS

Using a cadaveric radiocarpal dislocation model, the effect of distal fixation was studied in two stages: (1) A pilot study that investigated the effect of distal fixation alone; and (2) a more refined study that investigated the effect of described techniques for distal and proximal fixation. Radiographs were measured in various parameters to determine the quality of the reduction achieved.

RESULTS

The pilot study found that focusing on distal fixation alone without changing proximal fixation results in ulnar translocation and volar subluxation when fixing distally to the second metacarpal compared with the third. The second iteration demonstrated that anatomic alignment in coronal and sagittal planes could be achieved with each technique.

CONCLUSION

In a cadaveric radiocarpal dislocation model, anatomic alignment can be maintained with bridge plate fixation to the second metacarpal or the third metacarpal if the described technique is followed. When considering dorsal bridge plate fixation for radiocarpal dislocations, the surgeon is encouraged to understand the nuances of different fixation techniques and how implant design features may influence proximal placement.

Dumontier group 2 radiocarpal fracture-dislocation: The results of open reduction and fixation without volar ligament repair

INTRODUCTION

The radiocarpal fracture-dislocations are a spectrum of severe injury involving both the bony and ligamentous structures that stabilise the wrist joint. The aim of this study was to analyse the outcome of open reduction and fixation without volar ligament repair for Dumontier group 2 radiocarpal fracture-dislocation and to evaluate the incidence and clinical relevance of ulnar translation and advanced osteoarthritis.

PATIENTS AND METHODS

We retrospectively reviewed 22 patients with Dumontier group 2 radiocarpal fracture-dislocation treated in our institute. Clinical and radiological outcomes were recorded. Postoperative visual analogue scale (VAS) score for pain, Disabilities of the Arm, Shoulder and Hand Outcome Measure (DASH), and Mayo modified wrist scores (MMWS) were collected. Furthermore, extension‒flexion and supination‒pronation arcs were collected by reviewing chart, either. We divided the patients into two groups according to the presence or absence of advanced osteoarthritis, and presented the differences in the pain, disability, wrist performance, and range of motion between the two groups. We performed the same comparison between the patients with and those without the ulnar translation of the carpus.

RESULTS

There were sixteen men and six women with a median age of 23 years (range, 20‒48 years). The median follow-up period was 33 months (range, 12-149 months). The median VAS, DASH and MMWS were 0 (range 0-2), 9.1 (range, 0-65.9) and 80 (range, 45-90), respectively. The median flexion‒extension and pronation‒supination arcs were 142.5° (range, 20°‒170°) and 147.5° (range, 70°‒175°), respectively. Ulnar translation was recognised in four patients and the development of advanced osteoarthritis was noted in 13 patients during the follow-up period. However, neither was highly correlated with functional outcomes.

CONCLUSION

The current study postulated that ulnar translation might occur following treatment for Dumontier group 2 lesions, whereas injury was predominantly caused by rotational force. Therefore, radiocarpal instability should be recognized during the operation. However, the clinical relevance of ulnar translation and wrist osteoarthritis needs to be assessed in further comparison studies.

Volar Lunate Facet Fractures of the Distal Radius: Fracture Mapping Using 3D CT Scans

Background  Fractures of the distal radius involving the lunate facet at the volar articular surface are unstable injuries and are usually managed operatively. Management of these fractures is challenging as our understanding of the exact fracture characteristics and associated injuries to the carpus is poor. Purpose  This study aims to define the anatomy and associated injuries of lunate facet fractures using three-dimensional computed tomography (CT) scans and fracture mapping techniques. Methods  A consecutive series of CT wrists was analyzed to identify intra-articular fractures involving the lunate facet at the volar distal radius. Fractures were mapped onto standardized templates of the distal radius using previously described fracture mapping techniques. We also identified instabilities of the carpus including volar carpal translation, ulnar translocation, scapholunate diastasis, and distal radioulnar joint (DRUJ) instability. Results  We present 23 lunate facet fractures of the distal radius. The lunate facet fragment displaces in a volar and proximal direction and the lunate always articulates with the displaced fragment. The smaller fragments displace a greater amount, in a volar direction, with pronation. The fracture tends to occur between the origin of the short and long radiolunate ligaments. Conclusion  Lunate facet fractures are frequently comprised of osteoligamentous units of the distal radius involving the short and long radiolunate ligaments and the radioscaphocapitate ligament. Assessment and management of volar carpal subluxation, scapholunate instability, ulnar translocation, and DRUJ instability should be considered. Clinical relevance  Our mapping of these fractures contributes to our understanding of the anatomy and associated instabilities and will aid in surgical planning and decision making.

Volar Marginal Rim Fractures of the Distal Radius Have a Higher Rate of Associated Carpal Injuries-A Comparative Cohort Study

Background  Volar marginal rim distal radius fractures can be challenging due to volar instability of the carpus. The associated carpal injuries, however, have not previously been reported. Purpose  The aim of this study was to compare volar marginal rim fractures to other distal radius fractures to determine if there is any association with other carpal injuries. If so, do these injuries lead to further instability and fixation failure? Materials and Methods  A retrospective radiological review of 25 volar marginal rim fractures was conducted. This was compared with a comparison cohort of 25 consecutive intra-articular distal radius fractures not involving the volar marginal rim. All radiographs were reviewed for associated carpal injuries, including carpal and ulnar styloid fractures, scapholunate instability, and carpal translocation. Results  Volar marginal rim fractures had a significantly higher incidence of associated carpal injuries per patient (2.52 vs. 1.64), scapholunate diastasis (36 vs. 12%), and carpal dislocation (80 vs. 48%). The fixation chosen was more likely to involve a volar rim-specific plate (44 vs. 0%). Following surgical fixation, the volar marginal rim fractures had a significantly higher incidence of carpal instability (56 vs. 24%), failure of fixation (24 vs. 0%), and revision surgery (12 vs. 0%). Conclusions  Volar marginal rim fractures have significantly more carpal injuries, scapholunate instability, and volar carpal instability, compared with other distal radius fractures. Despite the use of volar rim-specific plating, volar marginal rim fractures have a significantly higher incidence of persistent carpal instability, including scapholunate instability, ulnar translocation, volar subluxation, failure of fixation, and revision surgery. Level of Evidence  This is a level III, retrospective review.

Kinematics of the wrist in Kienböck's disease: a four-dimensional computed tomography study

We studied the kinematics of 20 wrists affected by Kienböck's disease using four-dimensional computed tomography (4-D-CT) scanning. Degenerative changes progressed from the lunate facet to the scaphoid fossa at the radiocarpal articulation, then involved the midcarpal joint. Lunate fracture types included coronal (14/20), sagittal (10/20) and ligament attachment-types (8/20). Findings specific to dynamic scanning included the nutcracker phenomenon (12/20), anterior radiolunate impingement (7/20), internal instability of the lunate (6/20), ulnar styloid triquetral impingement (3/20) and dynamic proximal row instability (2/20). Ulnocarpal translocation was found in 4/20 cases. Dynamic 4-D-CT has helped us to identify a subset of pathology in Kienböck's disease on assessment of static imaging. Better understanding of these phenomena can improve our understanding of symptoms and may help direct surgical treatment.Level of evidence: IV.

Safety of Releasing the Volar Capsule During Open Treatment of Distal Radius Fractures: An Analysis of the Extrinsic Radiocarpal Ligaments' Contribution to Radiocarpal Stability

PURPOSE

The contribution of the extrinsic radiocarpal ligaments to carpal stability continues to be studied. Clinically, there is a concern for carpal instability from release of the volar extrinsic ligaments during volar plating of distal radius fractures in which the integrity of the dorsal ligaments may be unknown. The primary hypothesis of this study was that serial sectioning of radiocarpal ligaments would lead to progressive ulnar translation of the carpus.

METHODS

We studied the stabilizing roles of the radioscaphocapitate (RSC), short radiolunate (SRL), long radiolunate (LRL), and dorsal radiocarpal (DRC) ligaments. We sequentially sectioned these ligaments in 2 groups of 5 matched pairs and measured the motion of the scaphoid and lunate with the wrist in passive neutral alignment, radial deviation, ulnar deviation, and simulated grip. Displacement of the lunate in the radioulnar plane was used as a surrogate for carpal translation. The groups differed only by the order in which the ligaments were sectioned.

RESULTS

In the intact state, the lunate translated ulnarly during simulated grip and radial deviation, whereas radial translation, relative to its position under resting tension, was observed during ulnar deviation. With serial sectioning, the lunate displayed increased ulnar translation in all wrist positions for both groups 1 and 2. The magnitude of ulnar translation exceeded 1 mm after sectioning the LRL plus RSC along with either the DRC or the SRL.

CONCLUSIONS

Sectioning of either the DRC or SRL ligaments along with release of the RSC and LRL ligaments leads to notable although minimal (<2 mm) ulnar lunate translation.

CLINICAL RELEVANCE

Isolated sectioning of individual radiocarpal ligaments, such as for visualization of the articular surface of the distal radius, leads to minimal ulnar translation. Because prior clinical work found no clinical complications after volar capsule release, it is posited that translation less than 2 mm creates subclinical changes in carpal mechanics.

Perilunate Injury with Concomitant Short Radiolunate Ligament Disruption: Prevalence and Surgical Outcomes-"An Unusual Perilunate Injury Variant"

Background  In the classic description of perilunate injuries, the short radiolunate ligament (SRL) remains intact. Objective  This study was aimed to determine the occurrence of SRL disruptions with perilunate injuries and review the clinical and radiographic outcomes after surgical management. Patients and Methods  A retrospective review was conducted for patients who sustained a perilunate injury and a concomitant disruption of the SRL at a single-level-1 trauma center between January 2013 and January 2017. Patients with the combined injury pattern were compared with those with perilunate injury alone without SRL injury during the study period. Outcome measures included pain scores (visual analogue score), wrist and forearm range of motion, patient's return to their former occupation, and multiple radiographic parameters. Results  Twenty-seven patients were treated operatively for a perilunate injury. Eight of these patients (30%) were found to have associated disruption of the SRL. When compared with patients with perilunate injury alone, these patients had a lower rate of return to work (57% [4 of 7] vs. 92% [12 of 13]), a significantly longer mean length of time to return to work (5.9 vs. 3.8 months), and a higher rate of associated upper extremity injury (75% [3 of 8] vs. 16% [3 of 19]. Conclusion  Combined SRL disruption and perilunate dislocation or fracture dislocation represent a high-energy variant from the classic description of a perilunate injury. A heightened awareness for this combined injury pattern should be maintained when treating patients with perilunate injuries. Level of Evidence  This is a Level III, prognostic study.

Scaphoid translation measurements in normal wrists

The purpose of this study was to establish a normal measure of scaphoid position in the radioulnar plane in standard neutral, radial and ulnar deviation posteroanterior radiographs. This measurement may allow indirect evaluation of the radiocarpal ligaments and comparison between normal and pathologic states (following radius fractures, perilunate dislocations). Measurements were trialed on 74 normal wrist radiographs and 25 cadaver wrists. We evaluated the distance between the radial styloid and the scaphoid and corresponding scaphoid width. The ratio of distance/width at the mid styloid level (0.35, imprecision SD = 0.1) had the lowest random error and is therefore the most precise measurement of true scaphoid translation. This measurement is independent of scapholunate ligament integrity and may provide a better assessment of the radiocarpal component of ulnar translational instability. Abnormal movement of the scaphoid in the radioscaphoid joint likely reflects ligamentous injury. Identifying and addressing these injuries may prevent the development of arthritis.

Accurate quantitative measurement of lunate uncovering ratio--is Gilula's semiquantitative test reliable?

The Gilula's test suggests the presence of ulnocarpal translation when 50% or more of the lunate lies medial to the ulnar edge of radius. The purpose of this study was to examine the reliability of this semiquantitative test as there was inconsistency between the previous publications in regarding 50% as the cutoff value for the normal lunate uncovering ratio (LUR). We utilized the Picture Archiving and Communication System to investigate radiographs of 299 normal adult wrists and emphasized defined radiographic landmarks for accurate quantitative measurement. Our mean LUR was 35%(SD8) with a range of 8 to 49%. Therefore we re-affirmed the reliability of the Gilula's test since none of our normal wrists had a LUR of 50% or greater.

Perilunate dislocations and fracture dislocations

Perilunate dislocations and fracture dislocations are high-energy injuries that can result in pain, stiffness, weakness, or disability if inappropriately treated. Prompt recognition and surgical treatment with anatomic reduction of carpal malalignment improve the likelihood of optimal, long-term clinical success and patient satisfaction. The progressive development of radiographic evidence of arthrosis is common but has not been shown to consistently correlate with worse patient function and outcomes.

Traumatic ulnar translocation of the carpus: early recognition and treatment

This study evaluated the clinical outcomes and radiographic features of surgically treated traumatic ulnocarpal translocation in nine patients (ten cases). All ligament and fracture repairs were completed within 2 months of injury. Seven cases were examined at a mean of 6.5 years, and information in three cases was obtained from medical records at a mean of 13 months after injury. At final evaluation, the mean disabilities of the arm, shoulder, and hand score was 6 (range, 0-16), and the mean Mayo modified wrist score was 76 (range, 40-100). Ulnocarpal translocation was evident in nine of the injured wrists, six of which showed arthritis, and in four of the uninjured wrists. Ulnar variance measured negative in nine cases and neutral in one case. Pre-existing medial alignment of the carpus and ulnar minus variance may predispose to traumatic ulnocarpal translocation. Early injury repair does not assure restoration of radiocarpal alignment or prevent joint deterioration; however, these changes do not always portend a suboptimal result.

Scaphoid and lunate translation in the intact wrist and following ligament resection: a cadaver study

PURPOSE

To determine the amount of scaphoid and lunate translation that occurs in normal cadaver wrists during wrist motion, and to quantify the change in ulnar translation when specific dorsal and volar wrist ligaments were sectioned.

METHODS

We measured the scaphoid and lunate motion of 37 cadaver wrists during wrist radioulnar deviation and flexion-extension motions using a wrist joint motion simulator. We quantified the location of the centroids of the bones during each motion in the intact wrists and after sectioning either 2 dorsal ligaments along with the scapholunate interosseous ligament or 2 volar ligaments and the scapholunate interosseous ligament.

RESULTS

In the intact wrist, the scaphoid and lunate statistically translated radially with wrist ulnar deviation. With wrist flexion, the scaphoid moved volarly and the lunate dorsally. After sectioning either the dorsal or volar ligaments, the scaphoid moved radially. After sectioning the dorsal or volar ligaments, the lunate statistically moved ulnarly and volarly.

CONCLUSIONS

Measurable changes in the scaphoid and lunate translation occur with wrist motion and change with ligament sectioning. However, for the ligaments that were sectioned, these changes are small and an attempt to clinically measure these translations of the scaphoid and lunate radiographically may be limited. The results support the conclusion that ulnar translocation does not occur unless multiple ligaments are sectioned. Injury of more than the scapholunate interosseous ligament along with either the dorsal intercarpal and dorsal radiocarpal or the radioscaphocapitate and scaphotrapezial ligaments is needed to have large amounts of volar and ulnar translation.