Scaphoid proximal pole ejection in perilunate injury: a case report and pathophysiological hypothesis.

Isolated ejection of the scaphoid proximal pole in perilunate injuries is rare, with only 4 reports in the literature, and does not correspond to the biomechanical situations in the Herzberg or Mayfield classifications. Bone ejection incurs a risk of avascular necrosis despite good osteosynthesis, notably because of precarious vascularization. We present a case of scaphoid proximal pole ejection and a theoretical hypothesis of the biomechanics of this injury. LEVEL OF EVIDENCE: 4.

Lunate loads following different osteotomies used to treat Kienböck's disease: A 3D finite element analysis.

BACKGROUND: One of most accepted principles for treating Kienböck's disease before wrist degeneration settles in is to decompress the lunate by an osteotomy. Several osteotomies have been proposed since 1935. However, they are based on biomechanical hypotheses that are sometimes conflicting: This study compares the decompression effect of radius transverse shortening, radius lateral closing and medial closing wedge osteotomies, capitate shortening - with and without hamate shortening - and a Camembert-type radius wedge osteotomy with and without ulnar head shortening according to Sennwald. METHODS: We built a 3D wrist model using finite elements that included the metacarpal, carpal and forearm bones. All wrist ligaments and Triangular Fibrocartilage Complex were incorporated in the simulation. Load was applied on the metacarpals with the forearm bones fixed. We then applied the different osteotomies to the model. FINDINGS: When load was applied to the wrist, the osteotomies that best unloaded the lunate were the capitate shortening osteotomy combined with hamate shortening and the Camembert osteotomy combined with ulna shortening; the latter was the only osteotomy that completely unloaded the lunate. INTERPRETATION: We think the association of the radius Camembert osteotomy and ulna Sennwald's shortening osteotomy is the most effective procedure to propose in Kienböck's disease.

Lunate fracture healing after partial capitate shortening in Kienböck disease.

BACKGROUND: It is unclear whether lunate fracture types in Kienböck disease correlate with the degree of fracture healing. This study aimed to review the clinical results of stage 3 Kienböck disease treated using partial capitate shortening (PCS) and to evaluate the healing rates of lunate fractures based on the fracture types. METHODS: Twenty-three patients were clinically and radiographically followed up for >2 years after PCS. The preoperative location and postoperative healing of the lunate fracture were evaluated using plain radiography, computed tomography, and/or magnetic resonance imaging. Results were evaluated using the Kienböck scoring system by Nakamura. RESULTS: PCS was clinically effective, demonstrating excellent and good results in 11 and 11 patients, respectively. Pain evaluated using the visual analog scale, wrist extension, flexion motion, and grip strength significantly improved postoperatively (p < 0.01). Fractures were preoperatively detected in all 23 cases. Fracture locations were preoperatively classified into five subtypes based on radiographs: volar pole in five patients, dorsal pole in three, coronal in five, transverse in nine, and ulnar in one. The overall union rate of the lunate fracture was 48%, whereas none of the coronal fractures healed. CONCLUSIONS: PCS was effective in treating stage 3 Kienböck disease. Coronal lunate fractures had a poor healing rate relative to those of the other fracture types. STUDY DESIGN: Clinical, retrospective study.

Bilateral scapholunate widening may have a nontraumatic aetiology and progress to carpal instability and osteoarthritis with advancing age.

It was hypothesized that bilateral widening of the scapholunate gap is relatively common in the absence of trauma and that it progresses to radiological carpal instability and scapholunate advanced collapse. Electronic files of 1000 patients with bilateral X-rays were studied in retrospect. Wide scapholunate gaps were bilaterally present in 67 and unilaterally in 51 patients. Scapholunate advanced collapse was observed in 26 patients; in nine it was in both wrists. A trauma was recorded in less than half of the patients with a bilateral wide scapholunate gap. Patients with bilateral wide gaps were younger if signs of carpal instability or osteoarthritis were absent. Bilateral scapholunate widening may not be caused by an acute trauma, but may lead to carpal instability and degenerative changes with advancing age.

Palmar Capsuloligamentous Plication in Dorsal Capitolunate Instability: Technique and Preliminary Results.

Midcarpal instability (MCI) is a form of the carpal instability nondissociative pattern and can be differentiated into dorsal, palmar, or extrinsic MCI. Dorsal MCI can frequently be observed in adolescent or adult patients due to trauma or hyperlaxity of the palmar intrinsic carpal ligaments. Clinical stress tests and cinematography are capable to depict the ligamentous instability centered around the capitolunate area. We describe a novel technique which aims to address palmar ligamentous hyperlaxity by plication of the radioscaphocapitate, radiolunotriquetral, and arcuate ligaments, thus closing the so-called space of Poirier. This palmar technique has been used in several cases in isolated form or in conjunction with other concomitant procedures. After the floor of the carpal tunnel and thus the palmar ligaments are exposed and the weak spot meticulously verified, 2 or rarely 3 deep FibreWire pulley sutures are used for capsuloligamentous plication. Among 11 patients, 4 cases (5 operated wrists) with isolated capitolunate capsuloligamentous plication were followed at an average of 2.6 years after surgery. The results were excellent with a mean postoperative Disabilities of the Arm, Shoulder and Hand Score of 9.7 (range, 6.9 to 15.0), mean numerical rating scale of 0 at rest and 1 (range, 0 to 2) during stress. All cases stated that they were very satisfied with the result and all would definitely elect to choose the surgery again. Palmar capsuloligamentous plication has been shown to be a quick, relatively easy and reliable procedure to reduce dorsal MCI in our patient cohort.

Arthroscopy-assisted treatment of scaphoid and lunate cysts: Clinical evaluation of 7 cases.

Intraosseous cysts of the carpus are relatively common benign tumors. They are often discovered by chance and can cause wrist pain thereby requiring appropriate management. While conventional open surgical treatment leads to good results, it has certain disadvantages, the main one being postoperative stiffness. Arthroscopic treatment has been proposed as an alternative for lunate cysts. The present study consisted in evaluating the feasibility and outcomes of arthroscopic treatment for lunate and scaphoid cysts. The main objective was to evaluate the postoperative clinical outcomes at 3 and 18 months. The secondary objective was to evaluate the integration of a cancellous bone graft. We conducted a retrospective study of eight patients who underwent surgery between April 2010 and October 2016. Of these, four had a lunate cyst and four had a scaphoid cyst; all cysts had a dorsal operculum. Patients had disabling wrist pain that did not respond to conservative treatment. The diagnosis was confirmed by radiography and either a CT scan or an MRI. Curettage and cancellous grafts were performed under arthroscopic control. The technique was carried out successfully in all cases. One patient was lost to follow-up. At 18 months, postoperative pain was rated at 1.28 on a visual analog scale. The grip strength (measured with a Jamar dynanometer) was 77% when compared to the contralateral side. There was an improvement in joint range of motion, with an average wrist flexion of 67.5° compared to 48.3° preoperatively and an average wrist extension of 71.5° compared to 47.6° preoperatively. The Patient-Rated Wrist Evaluation (PRWE) score decreased from 69.7 to 12.7, which was a significant decrease. A good integration of the cancellous graft was confirmed at 6 months in all cases by CT scan or MRI. Curettage with a cancellous graft of lunate and scaphoid cysts under arthroscopic control is a technique that allows surgeons to obtain satisfactory clinical results with good integration of the graft.

Force Required to Maintain Reduction of a Preexisting Scapholunate Dissociation.

PURPOSE: To determine the force required to maintain reduction of Geissler grade 4 scapholunate dissociations during physiological wrist motions. METHODS: Fresh-frozen cadaveric wrists with Geissler grade 4 scapholunate dissociations were identified by arthroscopy. Following reduction, a load cell was attached to measure the force across the scapholunate joint at a neutral position and during 4 different wrist motions re-created using a servohydraulic wrist simulator, including a large flexion-extension motion (FEM), small and large dart-thrower's motions (DTMs), and a large DTM with ulnar offset. RESULTS: Five wrists with isolated preexisting scapholunate interosseous ligament (SLIL) tears were analyzed. The force required to maintain reduction was significantly greater in extension than in flexion during the large FEM and large DTM with ulnar offset. The forces were significantly larger in this study of preexisting SLIL dissociations compared with results from a prior study of acutely sectioned SLILs. In addition, forces to maintain reduction during DTMs were significantly less than forces during FEMs. Finally, a set of 3 wrists with preexisting scapholunate and lunotriquetral interosseous ligament (LTIL) tears were identified and had significantly decreased forces to maintain reduction at maximum extension and had decreased maximal forces during a cycle of motion compared with the wrists with isolated SLIL tears. CONCLUSIONS: The forces required to maintain reduction of a Geissler grade 4 wrist are higher than forces after acutely sectioned SLIL. The forces are greater in extension than in flexion and less during the DTM compared with the FEM. Wrists with both SLIL and LTIL tears required less force to maintain reduction than those with isolated SLIL tears. CLINICAL RELEVANCE: This study helps determine the strength of reconstruction required to maintain reduction of a Geissler grade 4 scapholunate dissociation.

Treatment of chronic scapholunate dissociation with tenodesis: A systematic review.

Scapholunate (SL) instability is the most common dissociative carpal instability condition. It is the most frequent cause of wrist osteoarthritis, defined as scapholunate advanced collapse or SLAC wrist. Familiarity with the SL ligament complex is required to understand the various features of SL instability. Damage to the SL interosseous ligament is the main prerequisite for SL instability; however the extrinsic, palmar and dorsal ligaments of the carpus also come into play. When more than 6 weeks has passed since the initial injury event, SL instability is considered chronic because ligament healing is no longer possible. Before osteoarthritis sets in and when the SL instability is still reducible (scaphoid can be reverticalized), ligament reconstruction surgery is indicated. Since the end of the 1970s, various ligament reconstruction or tenodesis techniques have been described. These techniques are used in cases of chronic, dynamic or static reducible SL instability, when no repairable ligament stump and no chondral lesions are present. The aim is to correct the SL instability using a free or pedicled tendon graft to reduce pain while limiting the loss of mobility and protecting against osteoarthritis-related collapse in the long-term. We will perform a systematic review of the various tenodesis techniques available in the literature.

The effect of screw trajectory for the reduction and association of the scaphoid and lunate (RASL) procedure: a biomechanical analysis.

The purpose of this study was to determine if screw placement in the reduction and association of the scaphoid and the lunate (RASL) procedure affected the ability of the scapholunate joint to withstand force. After completely disrupting of the scapholunate ligament in 29 fresh-frozen cadaveric wrists, we placed the RASL screw either distal or proximal to the lateral aspect of the dorsal ridge of the scaphoid and into the dorsal or volar aspect of the lunate. Specimens were subjected to repeated cycles of transcarpal axial force, mimicking clenched-fist loading, until failure. Screw placement distal to the lateral aspect of the dorsal scaphoid ridge was significantly associated with failure when examined manually, radiographically (1.8 vs. 0.5 mm) and using real-time motion capture (diastasis: 1.6 vs. 0.4 mm; Euler angle: 4.5 ° vs. 0.8 °). The lateral aspect of the dorsal ridge is a reliable radiographic landmark on the scaphoid and provides surgeons with a convenient starting point to achieve the most biomechanically stable RASL construct, and, therefore, enhances the potential for an optimal clinical outcome.

Impact of scapholunate dissociation on human wrist kinematics.

Neither the complex motions of the scapholunate joint, nor the kinematic changes that occur as a result of injury to it, are fully understood. We used electromagnetic tracking within affected bones to evaluate the physiologic motions in the planes of flexion and extension, and of radial and ulnar deviation of human cadaver wrists, before and after complete transection of the scapholunate ligaments. Despite individual variance between each wrist, we were able to establish a pattern in the changes that occurred after scapholunate ligament injury. During the motions examined, the scaphoid showed an increase in translational deviation in almost all motion axes. In contrast, the movement of the lunate seemed to be impaired, especially in radial-ulnar deviation.

Perilunate fracture-dislocations: clinical and radiological results of 21 cases.

BACKGROUND: Perilunate dislocations and fracture-dislocations are a subcategory of the carpal instability complex. Herein, we report our university hospital experience with this complex injury. The goal of our study was to find predictive factors and quantify the development of arthritis and lunate necrosis. We tried to measure the impact of arthritis on hand function. METHODS: Between January 2000 and December 2014, 21 patients underwent surgery for perilunate dislocations and perilunate fracture-dislocations of the wrist in our tertiary university center. Mean patient age was 29.3 ± 10.0 years (range 18-49 years). All displacements were posterior. They were reviewed both clinically and radiologically. RESULTS: Complications included misdiagnosed Essex-Lopresti-like lesion in one case, insufficient reposition of the carpus in two cases (LT in one case, SL in one case), and iatrogenic injury to the radial artery immediately sutured in one case. All 3 cases underwent a second procedure with satisfactory outcome. After a mean follow-up of 112 ± 60 months (range 12-210 months), the average Cooney score was 80 ± 19 (range 50-125). The mean PRWE score was 10 ± 8 (range 0-25). The mean DASH score was 40 ± 13 (range 30-75 months). Mean pain on load, measured with VAS was 1.1 ± 1.6; Clinical examination assessed a mean wrist extension/flexion of 42.4° ± 17.2°/48.4° ± 15.2°. Mean wrist ulnar/radial deviation was, respectively, 22.9° ± 11.3°/15.3° ± 7.0°. Mean pro/supination was, respectively, 75.2° ± 11.5°/76.3° ± 8.1°. Mean pinch strength was 9.4 ± 2.2 kg (87.4 ± 17.7% of the contralateral side). Mean power strength was 41.9 ± 9.9 kg (76.2 ± 19.2% of the contralateral side). Two patients had a scaphoid non-union identified on their most recent imaging. The mean carpal height ratio was 0.53 ± 0.05 (range 0.44-0.65). All except one patient developed arthritis: Grade 1 in 11 patients, Grade 2 in 3 patients, and Grade 3 in the remaining 6 patients. Age, length of follow-up, and loss of reduction were significantly associated with wrist arthritis (p < 0.001). Lunate avascular necrosis assessed by magnetic resonance imaging was present in 6 patients: Stage 2 in 4 patients, Stage 3a in 1 patient, and Stage 3b in the remaining patient. All these patients' intraoperative findings showed lesion of the cartilage of the radial side of the lunate. However, the small number of patients who developed lunate necrosis did not allow satisfactory statistical analysis. CONCLUSIONS: This retrospective study demonstrates good functional results despite the high rate of radiological wrist arthritis. Age, length of follow-up, and loss of reduction were significantly associated with wrist arthritis in our series.

Evaluation of the performance of three tenodesis techniques for the treatment of scapholunate instability: flexion-extension and radial-ulnar deviation.

Chronic scapholunate ligament (SL) injuries are difficult to treat and can lead to wrist dysfunction. Whilst several tendon reconstruction techniques have been employed in the management of SL instability, SL gap reappearance after surgery has been reported. Using a finite element model and cadaveric study data, we investigated the performance of the Corella, scapholunate axis (SLAM) and modified Brunelli tenodesis (MBT) techniques. Scapholunate dorsal and volar gap and angle were obtained following virtual surgery undertaken using each of the three reconstruction methods with the wrist positioned in flexion, extension, ulnar deviation and radial deviation, in addition to the ulnar-deviated clenched fist and neutral positions. From the study, it was found that, following simulated scapholunate interosseous ligament rupture, the Corella technique was better able to restore the SL gap and angle close to the intact ligament for all wrist positions investigated, followed by SLAM and MBT. The results suggest that for the tendon reconstruction techniques, the use of multiple junction points between scaphoid and lunate may be of benefit. Graphical abstract The use of multiple junction points between scaphoid and lunate may be of benefit for tendon reconstruction techniques.

Ten-Year Minimum Follow-Up of 4-Corner Fusion for SLAC and SNAC Wrist.

BACKGROUND: Scapholunate advanced collapse (SLAC) of the wrist is the most common degenerative condition of the wrist. Four-corner fusion (4CF) is performed as salvage surgery, though there is limited information on its long-term results. We hypothesized that 4CF is a durable surgery with good clinical long-term function. METHODS: A retrospective chart review of patients undergoing 4CF as well as an interview and recent radiographs were obtained. Patients with a follow-up period of less than 10 years were excluded. Long-term evaluation included standard wrist radiographs, wrist range of motion, and the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. Radiographs were evaluated and described by the Kellgren-Lawrence classification. RESULTS: Four hundred eighty-nine wrists underwent a 4CF for SLAC wrist from 1982 to 2003. Twelve patients (15 wrists) were available for follow-up. Average age at surgery was 49.1 years (range, 25-67 years). Average follow-up postsurgery was 18 years (11-27). Scapholunate advanced collapse was the etiology in 13 wrists and scaphoid nonunion advanced collapse in 2 wrists. Average extension/flexion arc was 68.6° (0°-96°), and radial/ulnar deviation arc was 32.9° (0°-5°). QuickDASH scores averaged 7.8 (range, 0-32.5), with only 1 score above 16. Seventy-three percent of radiographs showed minimal to moderate joint destruction, and 27% showed severe joint destruction. CONCLUSIONS: Scaphoid excision and 4CF remains a reliable procedure for patients with advanced wrist arthritis. Functional results were good at long-term follow-up despite radiographic changes in the radiolunate joint in 73% of patients. Patient satisfaction was high, and functional impairment was low.

Risk Factors of Lunate Collapse in Kienböck Disease.

PURPOSE: Not all patients with Kienböck disease progress to collapse of the lunate and carpal malalignment, but it is difficult to determine which patients are at risk. We aimed to identify demographic or anatomical factors associated with more advanced stages of Kienböck disease. METHODS: We included all 195 eligible patients with Kienböck disease and available preoperative posteroanterior and lateral radiographs. We compared the mean age, sex distribution, mean ulnar variance, radial height, radial (ulnarward) inclination, palmar tilt, anteroposterior distance, and lunate type among the different Lichtman stages of Kienböck disease and performed ordinal logistic regression analysis. RESULTS: We found that patients with more negative ulnar variance had more advanced stages of Kienböck disease (adjusted odds ratio, 1.4). An increase in age was also independently associated with a higher Lichtman stage of Kienböck disease (adjusted odds ratio, 1.02). CONCLUSIONS: Our findings suggest that more negative ulnar variance may be related to a greater magnitude of lunate collapse in Kienböck disease. Additional long-term study is needed to confirm the longitudinal relationship of negative ulnar variance with progressive Kienböck disease. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Radiological degenerative changes in the distal radioulnar joint after ulnar shortening osteotomy in patients with idiopathic ulnar impaction syndrome: Analysis of factors affecting degenerative lesions.

PURPOSE: To identify factors influencing overall radiologic changes in the distal radioulnar joint after ulnar shortening osteotomy (USO) in patients with idiopathic ulnar impaction syndrome. MATERIALS AND METHODS: A total of 310 patients who had undergone USO between May 2007 and December 2013 were included in this retrospective case-control study. The patients were classified into two groups (with or without radiologic findings of new arthritic changes), after which the following factors were analyzed: 1) demographic factors; 2) radiologic aspects, including ulnar variance (UV), morphological DRUJ type (classified according to Tolat et al.), and union period after USO; and 3) operative aspects, including the triangular fibrocartilage complex degeneration type, use of a parallel double-blade saw, type of plate used for fixation, and plate position on the volar or dorsal ulnar surface. RESULTS: Group 1 (no arthritic changes) consisted of 243 patients, whereas Group 2 (arthritic changes) consisted of 67 patients. Univariate and multivariate analyses showed that the presence of lunate cystic changes, amount of shortening, and the union period were significantly associated with newly developed arthritic changes in the distal radioulnar joint (DRUJ) after USO. The morphological DRUJ type was not a significant factor. Arthritic changes were significantly more prevalent in patients with a shortening amount >4.5 mm and a union period <3.25 months. CONCLUSIONS: Radiologic arthritic changes after USO, were associated with the presence of cystic changes in the lunate, a shortening amount (>4.5 mm), and early bony union (<3.25 months). TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic level III.

Evaluation of midcarpal capitate contact mechanics in normal, injured and post-operative wrists.

BACKGROUND: Scapholunate ligament injury is a commonly occurring carpal ligament injury. Pathology associated with scapholunate ligament injury depends on several factors such as the time after injury, type of injury (instability) and the development of osteoarthritis. The aim of this study was to investigate and compare contact mechanics in the lunocapitate and scaphocapitate joints in the normal, injured (scapholunate dissociation) and repaired (postoperative) wrist. METHODS: Four human subjects with scapholunate ligament dissociation participated in this study. MR images of normal (contralateral), injured and postoperative wrists were obtained during relaxed condition and during active light grasp. Relaxed MR images were used to construct model geometry (bones with cartilage) for the capitate, lunate and scaphoid. Kinematic transformations were obtained by using image registration between the unloaded and functionally loaded image sets. Joint surface contact mechanics were then calculated. FINDINGS: All contact measures (contact force, pressure, mean pressure and area) tended to increase with injury in both articulations. A significantly higher contact area was found in the injured scaphocapitate joint compared to normal. A significant increase in peak pressure was observed in the postoperative state compared to normal. INTERPRETATION: Injury to the scapholunate ligament increased contact measures, suggesting a risk for onset of osteoarthritis in both the scaphocapitate and lunocapitate joints. Surgical repair appeared to restore most measures of contact mechanics to near normal values, more so for the lunocapitate joint when compared to scaphocapitate joint. The elevated postoperative peak pressures indicate the difficulty to fully restore joint mechanics.

Changes in Wrist Motion After Simulated Scapholunate Arthrodesis: A Cadaveric Study.

PURPOSE: A high incidence of nonunion and relatively poor outcomes with prior fixation techniques has precluded scapholunate (SL) arthrodesis as a standard treatment for SL instability. Our purpose was to determine the impact on range of motion (ROM) of simulated SL arthrodesis via headless screw fixation. METHODS: We performed baseline wrist ROM for 10 cadaveric wrists using a standardized mounting-and-weights system. Extension, flexion, radial deviation, ulnar deviation, dart-thrower's extension, and dart-thrower's flexion were assessed. Two 3.0-mm headless compression screws were inserted across the SL joint to simulate SL arthrodesis. Goniometric measurements and fluoroscopic imaging were repeated to assess ROM differences after simulated SL arthrodesis. We assessed SL angle and gap during testing to ensure there was no significant motion between the scaphoid and lunate, thus confirming stable simulated fusion. Differences in ROM were compared between baseline and simulated SL arthrodesis using paired t tests. RESULTS: Mean SL angle remained constant between pre- and post-arthrodesis imaging (47° ± 6° vs 46° ± 4°) and did not change during post-arthrodesis ROM testing, indicating a stable simulated fusion. Compared with baseline, SL arthrodesis had a statistically significant reduction in maximum flexion of 6° and 9° based on fluoroscopy and goniometry, respectively, in dart-thrower's extension of 5° and 9° based on fluoroscopy and goniometry, respectively, and in dart-thrower's flexion of 6° for both fluoroscopy and goniometry. No other ROMs after simulated SL arthrodesis were significantly different compared with baseline. CONCLUSIONS: The effects of simulated SL arthrodesis on radiocarpal and midcarpal motion compare favorably with motion after SL soft tissue repair and other reconstructive techniques that have been previously reported. The statistically significant decreases in wrist flexion and dart-thrower's extension-flexion after simulated SL arthrodesis are of questionable clinical importance. CLINICAL RELEVANCE: These results may support reconsidering SL arthrodesis as a viable treatment option for acute or chronic SL instability with regard to apparent minimal adverse effects on functional wrist ROM.

The Role of Lunate Morphology on Scapholunate Instability and Fracture Location in Patients Treated for Scaphoid Nonunion.

BACKGROUND: To determine the association between lunate morphology and the scapholunate instability using radiographic images, and investigate the association between lunate morphology and scaphoid fracture location. METHODS: Between January 2003 and December 2011, we retrospectively evaluated the plain radiographs and computed tomography (CT) images of 70 patients who underwent surgical intervention for a scaphoid nonunion, in order to determine the association between lunate type (I or II) and scapholunate instability or scaphoid fracture location. We determined the scaphoid fracture location using the fragment ratio and measured the radiolunate angle and capitate-triquetrum (C-T) distance. RESULTS: A type II lunate was present in 68.6% (48 of 70 cases). Mean fragment ratio of fracture location was 50.6% in the type II lunate group and 56.2% in the type I lunate group (p = 0.032). Sixteen of the 70 patients had dorsal intercalated segmental instability (DISI) deformities. Nine of 22 cases showed DISI deformity in type I lunate and 7 of 48 cases showed DISI deformity in type II lunate (p = 0.029). However, there were no significant differences between the presence of DISI deformity and fracture location (p = 0.15). Morphologic comparisons by both plain radiography and CT indicated a mean C-T distance in the type I lunate group (22 cases) of 2.3 mm and 5.0 mm in the type II lunate group (48 cases). The C-T distances were significantly correlated with lunate morphology (p = 0.001). CONCLUSIONS: A type II lunate was associated with low incidence of DISI deformity and proximal location of fracture in patients presenting with a scaphoid nonunion.

Fixed Lunate Flexion Deformity in Distal Radius Fractures.

Carpal malalignments in malunion of distal radius fracture are considered as an adaptive response of the carpus to loss of normal architecture of the distal radius. This condition leads to mechanical overload, ligament attenuation and progressive dynamic instability around the wrist joint. Radial corrective osteotomy is suggested as a treatment option of carpal malalignment after distal radius malunion. In radiocarpal malalignment, the lunate is usually observed in flexion in contrast to its extension posture in the more common midcarpal malalignment. We report two cases of fixed lunate flexion deformity after a distal radius fracture, in which reduction and fixation of fresh fracture or corrective osteotomy of malunion were not successful. Arthritic changes were observed in the radiolunate joint on arthroscopy. Thus, fixed flexion deformity of the lunate might be associated with posttraumatic arthritic change in the radiolunate joint.

Scapholunate kinematics of asymptomatic wrists in comparison with symptomatic contralateral wrists using four-dimensional CT examinations: initial clinical experience.

OBJECTIVES: Using four-dimensional CT scan (4DCT), we aimed at showing the kinematics of scapholunate (SL) interval in asymptomatic wrists in comparison with symptomatic contralateral wrists with inconclusive radiographic findings. METHODS: This is an IRB approved, HIPPA compliant, retrospective study. Patients suspected of SL interosseous ligament (SLIL) injuries were referred for further evaluation of chronic wrist pain (>3 months). Twelve wrists (11 subjects) with chronic symptoms and inconclusive plain radiographs and 10 asymptomatic wrists (in 10 different subjects) were scanned using 4DCT. The minimum SL interval was measured during three wrist motions: relaxed-to-clenched fist, flexion-to-extension, and radial-to-ulnar-deviation. Changes were recorded using double-oblique multiplanar reformation technique. RESULTS: We extracted the normal limits of the SL interval as measured by dynamic CT scanning during active motion in asymptomatic wrists. In asymptomatic wrists, the average SL interval was observed to be smaller than 1 mm during all motions. In symptomatic wrists, during exams performed with clenched fist (SL interval (mean ± SD) = 2.53 ± 1.19 mm), extension (2.54 ± 1.48 mm) or ulnar deviation (2.06 ± 1.12 mm), the average SL interval was more than 2 mm. In contrast to symptomatic wrists, no significant change in SL interval measurements was detected during wrist motions in asymptomatic wrists. There was a mild to moderate correlation between SL interval change and presence/absence of symptoms (point-biserial correlation coefficients: 0.29-0.55). CONCLUSION: In patients with wrist pain suspicious for SLIL injury and inconclusive radiographs, SL interval increase can be detected with 4DCT in the symptomatic wrist compared to the asymptomatic wrist.