Treatment and Outcomes of Missed Perilunate Dislocations: A Case Series

Background  Perilunate dislocations are devastating injuries that occur relatively rarely, accounting for only 7% of injuries to the carpus. Unfortunately, approximately 25% of these injuries are missed on initial evaluation. Acutely diagnosed perilunate dislocations may be successfully treated with ligament and osseous repair, depending on the injury pattern. Chronic dislocations, however, are primarily treated with salvage procedures. This case series was performed to investigate the outcomes of patients who sustained a perilunate dislocation that was diagnosed in a delayed fashion and look for any treatment patterns that could be more widely applied to future patients. Methods  Patients presenting to a single institution between 2016 and 2018 with a perilunate injury that either presented in a delayed fashion or was missed on initial assessment were identified and their characteristics were evaluated. The surgical management of these patients was assessed as was their postoperative course at their 2-week, 6-week, 3-month, and 6-month clinic follow-up visits. Results  Eight patients were identified with perilunate dislocations that were diagnosed in a delayed fashion. On average, these dislocations were diagnosed 133 days following the date of injury. All patients were males and 7/8 of them were between 17 and 20 years of age at the time of their injury (mean age: 25.5). They were treated with either primary repair, wrist fusion, proximal row carpectomy, or scaphoid excision and four-corner fusion (SEFCF). Both pain and range of motion improved following surgical management of these injuries. Conclusion  Perilunate dislocations are rare injuries that are notorious for being diagnosed late, at which point primary repair is oftentimes no longer feasible. Salvage procedures are able to improve the range of motion and pain of patients who are found to have chronic dislocations. Our case series highlights the importance of treating each missed perilunate injury individually and avoiding a "one-size-fits-all" approach.

Intraosseous Ganglion Spanning the Scaphoid and Lunate: A Case Report

Intraosseous ganglions (IOGs) are actually quite common but one spanning two adjacent carpal bones is uncommon. We report a case with an IOG spanning the scaphoid and lunate, which was treated surgically. A 16-year-old right-handed female noticed left wrist pain that started spontaneously five years previously. Physical findings indicated carpal instability in the left wrist. Posteroanterior radiographs of the left wrist showed small cysts in the lunate and scaphoid, while the lateral radiograph revealed volar flexion of the lunate. Bone curettage was performed using sharp curettes, and due to the physical findings of carpal instability, temporary scapho-trapezoidal joint fixation was done using two Kirchner wires. Two years post-surgery, wrist pain had significantly improved and carpal instability findings disappeared. Computed tomography revealed no obvious collapse of carpal bones and expansion of bone defects in the lunate and scaphoid. Bone formation was observed in the bone curettage area of the scaphoid.

The Effect of Radial Inclination on the Stage of Kienbock Disease at the Time of Initial Diagnosis

BACKGROUND

Negative ulnar variance is a widely accepted risk factor for the development of Kienbock disease (KD). Variation in radial inclination has been proposed as a risk factor, but evidence thus far has been inconclusive. We aim to clarify the relationship between radial inclination and KD.

METHODS

A retrospective analysis of all KD patients from a single institution from 2007 to 2021 was conducted. Radiographs were reviewed to measure anatomic parameters and stage of disease. An exploratory multinomial regression model was created to examine the association of patient age, radial height, ulnar variance, radial inclination, volar tilt, scapholunate angle, duration of symptoms prior to evaluation, history of wrist trauma, and diagnosis of diabetes with stage of disease.

RESULTS

Fifty-seven cases of KD were identified, with a mean duration of disease of 33.3 months. A history of trauma to the wrist was common (53%) and significantly associated with stage of disease at initial presentation. Twenty-seven cases (47%) were stage IIIB or greater. The average initial radial inclination, radial height, and ulnar variance was 21.9°, 10.7 mm, and -1.23 mm, respectively. A multinominal logistic regression model revealed decreased initial radial inclination is associated with Lichtman stage IIIB or greater at the time of initial patient presentation.

CONCLUSIONS

A correlation exists between decreased radial inclination and more advanced KD at presentation, suggesting this may be a risk factor for disease progression. This correlation is strengthened by our finding of decreased ulnar variance being associated with later stage at presentation, which is one of the most widely accepted proposed risk factors for development and progression of disease.

LEVEL OF EVIDENCE

IV.

Palmar Divergent Dislocation of the Scaphoid and Lunate

Teaching Point: Palmar dislocation of the scaphoid and lunate is an extremely uncommon injury that warrants early diagnosis and treatment to avoid complications such as median nerve dysfunction, avascular necrosis, and premature osteoarthritis.

Conservative Management of Kienbock's Disease in a 7-year Old: A Case Report

Background  Kienbock's disease is primarily seen in young adult males but has been recognized in skeletally immature populations as well. Traditional treatment strategies recommend operative treatment but high remodeling potential in children may allow conservative management. Case Description  We present the case of a 7-year-old female with 2 months of atraumatic right wrist pain who was found to have edematous signal change within the lunate on wrist magnetic resonance imaging (MRI) consistent with Kienbock's disease. She was treated with rigid immobilization for 12 weeks and transitioned to custom orthotic splint for another 3 months during activities. At her 6 month follow-up, she reported minimal wrist pain with repeat MRI demonstrating the resolution of lunate edema. Literature Review  Available literature shows a significant portion of patients treated conservatively subsequently require surgical intervention due to unresolved symptoms or progressive disease. Only three cases are reported in the literature where skeletally immature patients were successfully treated with conservative management alone Clinical Relevance  We report the youngest case of Lichtman stage I Kienbock's disease successfully treated with conservative management resulting in clinical and imaging resolution. Younger patients may be able to successfully remodel and recover from Kienbock disease with extended time in conservative management.

Effect of Capitolunate Positioning on Outcomes in Scaphoid Excision and 4-Bone Fusion Patients

BACKGROUND

Scaphoid excision and 4-bone fusion (4BF) is a surgical procedure to treat scapholunate advanced collapse. Some surgeons align the lunate over the capitates, whereas others leave the capitate in its uncovered native position. The capitolunate angle may affect long-term outcomes. This study examined whether postsurgical outcomes differed based on these differences in positioning.

METHODS

A retrospective analysis was performed for patients that underwent a 4BF between 2006 and 2020. Wrist range of motion; pain (0-10); and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were recorded. The width of the capitate, the width of the lunate contacting the capitate, and the capitolunate angle were measured. Pearson correlations and t tests were performed. For t tests of capitolunate uncovering, patients were divided into 2 groups: patients with 0% capitate uncovering and patients with >0% uncovering. For capitolunate angle, the 2 groups were patients with a capitolunate angle of ≤10° and patients with a capitolunate angle of >10°.

RESULTS

There was a significant correlation between capitate coverage and wrist extension, but no correlation for flexion, pain, or DASH scores. Group 1 (0% uncovering) had increased wrist extension and decreased pain compared with group 2 (>0% uncovering). There were no significant correlations or differences in the analyses of capitolunate angle's impact on outcomes.

CONCLUSIONS

In patients undergoing 4BF, those who had the lunate aligned to completely cover the capitate head had improved wrist extension and pain compared with patients where the capitate head was left partially uncovered. Capitolunate angle was not predictive of postsurgical outcomes.

Diagnostic performance of traditional radiographic indices in detection of carpal collapse in Kienböck's disease

Correctly identifying carpal collapse is important for adequate treatment of Kienböck's disease. This study aimed to assess the accuracy of traditional radiographic indices in detecting carpal collapse to differentiate between Lichtman stages IIIa and IIIb. In 301 patients, carpal height ratio, revised carpal height ratio, Ståhl index and radioscaphoid angle were measured on plain radiographs by two blinded observers. As a reference standard, Lichtman stages were determined by an expert radiologist using CT and MR imaging. The interobserver agreement was excellent. In the differentiation between Lichtman stages IIIa and IIIb, measurements of indices showed moderate to good sensitivity (0.60-0.95) and low specificity (0.09-0.69) using normal cut-off values from the literature, while receiver operating curve analysis revealed poor area under the curve (58-66%). Traditional radiographic indices showed poor diagnostic performance in detecting carpal collapse in Kienböck's disease and did not reach sufficient accuracy in the differentiation between Lichtman stages IIIa and IIIb.Level of evidence: III.

Lunate Fracture Morphology in Kienbock's Disease-A Computed Tomography Study

Background  The pathogenesis of Kienbock's disease is poorly understood. The coronal fracture line is acknowledged as a poor prognostic marker in the disease. Other fracture types in the Kienbock's wrist have subsequently been identified. Questions/Purposes  The aim is to study the fracture morphology of the lunate in a cohort of patients using computed tomography. Methods  Patient images were acquired using a set protocol with four-dimensional computed tomography scanning. Images were reviewed by two orthopaedic surgeons and a consultant radiologist. Static and dynamic images were assessed and a fracture map created. The relationship of fracture type to other parameters was then analyzed. Results  Twenty-three patients were included in the study, including 11 males and 12 females, with a mean age of 43 years. Total frequency of fracture lines in the cohort was coronal - 26, proximal subchondral bone plate type - 24, avulsion - 19, sagittal - 16, and distal subchondral bone plate type - 11. There were statistically significantly more proximal than distal subchondral bone plate fractures ( p  = 0.03), and more coronal fractures than distal subchondral bone plate fractures ( p  = 0.01). There were statistically significantly more radiolunate ligament-avulsion types ( p <0.001) than other types. The sagittal fracture line through the lunate approximated closely to the ulnar edge of the capitate and the ulnar edge of the radius. Conclusion  Study on the fracture morphology in the Kienbock's wrist has improved our understanding of the disease pathogenesis. Fracture lines may correspond to loading points, intrinsic and extrinsic ligament avulsions. These fracture types may play a role in disease progression and are important to identify when considering lunate salvage surgery.

Radiographic Scapholunate Interval in the Pediatric Population Decreases in Size as Age Increases

BACKGROUND

Widening of the scapholunate (SL) interval greater than 2 mm is diagnostic of an injury in adults; however, this absolute number cannot be used for skeletally immature individuals due to the ossification of the carpal bones. The purpose of this study was to determine age-appropriate normative values for the radiographic SL interval in the skeletally immature population.

METHODS

Normal pediatric wrist radiographs were identified. The radiographic SL interval was measured as the distance between the scaphoid and the lunate at the mid-joint space between the scaphoid and the lunate, and the SL and capitolunate angles were measured on lateral views. An initial inter-rater reliability assessment was completed with strong inter-rater reliability.

RESULTS

In all, 529 radiographic series of children (276 male), aged 4 to 17 years, were reviewed. A negative linear correlation between chronological age and distance at the mid-joint space was observed. The average values for the radiographic SL interval ranged from 9.07 to 1.57 mm. The average SL and capitolunate angles were 52.0° and 10.6°, respectively. No linear relationship was found between chronological age and SL or capitolunate angle (R = 0.07 and 0.03, respectively).

CONCLUSIONS

The visible radiographic distance between the scaphoid and the lunate decreases with increasing age as the carpal bones ossify. The normative values defined in this study can be used to determine whether a true widening of the SL interval is present in the pediatric population. No linear relationship exists between chronological age and SL or capitolunate angle.

Lunate Revascularization With Temporary Internal Radiocarpal Spanning Fixation for Kienböck Disease

BACKGROUND

The goal in the treatment of stages II and III Kienböck disease is to restore lunate vascularity and halt the progression of avascular necrosis.

METHODS

We report the outcomes for patients with stages II and III Kienböck disease treated with fourth extensor compartment artery vascularized bone grafting and temporary radiocarpal spanning internal fixation. Nine patients with a mean age of 28.8 years were included. Mean clinical and radiographic follow-up were 4.9 and 1.9 years, respectively.

RESULTS

Six patients had no change in Lichtman stage, 2 patients regressed 1 stage, and 1 patient progressed 1 stage. Mean postoperative quick disabilities of the arm, shoulder, and hand (QuickDASH) was 17.4. Mean postoperative visual analogue pain scale (VAS) was 1.8. Patients under age 25 trended toward improved clinical outcomes compared with patients over age 25. Two patients, aged 33 and 65, underwent proximal row carpectomy at a mean 30.5 months postoperatively.

CONCLUSIONS

In conclusion, the use of local vascularized bone graft with temporary internal radiocarpal spanning fixation provides a treatment option with outcomes comparable to existing literature with benefits inherent to internal immobilization.

Long-term Outcomes for Late-Phase Kienböck's Tenoarthroplasty

BACKGROUND

In late Kienbӧck's, the lunate is fully fragmented and nonreconstructible. Replacing the lunate with a pyrocarbon prosthesis preserves load distribution and avoids carpectomy or fusion, but leaves the wrist intrinsically unstable, requiring additional soft-tissue stabilization techniques.

METHODS

Five men and 7 women with a mean age of 43 (±15) years underwent prosthetic replacement of the lunate with dual bundle scaphoid-triquetrum tenodesis for carpal stabilization. The mean follow-up interval from initial surgery was 9.1 (±1.7) years. Outcomes were Disabilities of Arm, Shoulder, and Hand (DASH) score, revision or conversion surgery, and wrist range of motion.

RESULTS

The mean DASH score was 8.9 (±7.1). No patients reported any additional revision or conversion surgery. The mean wrist flexion was 60° (±14°); wrist extension was 45° (±21°).

CONCLUSIONS

Clinical outcomes proved more favorable than anticipated, particularly the self-rated outcomes scores and the absence of any revision or conversion surgery.

The Intercalated Segment: Does the Triquetrum Move in Synchrony With the Lunate?

PURPOSE

To quantify the relative motion between the lunate and triquetrum during functional wrist movements and to examine the impact of wrist laxity on triquetral motion.

METHODS

A digital database of wrist bone anatomy and carpal kinematics for 10 healthy volunteers in 10 different positions was used to study triquetral kinematics. The orientation of radiotriquetral (RT) and radiolunate rotation axes was compared during a variety of functional wrist movements, including radioulnar deviation (RUD) and flexion-extension (FE), and during a hammering task. The motion of the triquetrum relative to the radius during wrist RUD was compared with passive FE range of motion measurements (used as a surrogate measure for wrist laxity).

RESULTS

The difference in the orientation of the radiolunate and RT rotation axes was less than 20° during most of the motions studied, except for radial deviation and for the first stage of the hammering task. During wrist RUD, the orientation of the RT rotation axis varied as a function of passive FE wrist range of motion.

CONCLUSIONS

The suggestion that the lunate and triquetrum move together as an intercalated segment may be an oversimplification. We observed synchronous movement during some motions, but as the wrist entered RUD, the lunate and triquetrum no longer moved synchronously. These findings challenge the assumptions behind models describing the mechanical function of the carpals.

CLINICAL RELEVANCE

Individual-specific differences in the amount of relative motion between the triquetrum and lunate may contribute to the variability in outcomes following lunotriquetral arthrodesis. Variation in triquetral motion patterns may also have an impact on the ability of the triquetrum to extend the lunate, affecting the development of carpal instability.

Precision Medicine for Kienböck Disease in the 21st Century

One of the most popular treatment algorithms for Kienböck disease is based on a progression of successive radiographic changes that was developed in the 1970s. Since then, 2 other important classifications systems have been introduced. One is centered on contrasted magnetic resonance imaging findings and the other, articular cartilage degeneration. All 3 systems have been used, in isolation, to recommend specific treatment modalities. To coordinate all available clinical data and to simplify the treatment selection process, we combined the 3 classification systems into 1 unified classification and treatment algorithm. With the added consideration of some recently introduced surgical options and further knowledge of how Kienböck disease affects children and the elderly, we anticipate that this unified classification system will allow for a more precise and individualized treatment plan.

Association of Lunate Morphology With Progression to Scaphoid Fracture Nonunion

Background: The purpose of our study was to review a series of patients with scaphoid fractures to determine whether there was an association between lunate morphology and progression to delayed union or nonunion when treated operatively or nonoperatively. Secondary aims included evaluation of the relationship between lunate morphology and scaphoid fracture location. Methods: A retrospective review of all patients with a diagnosis of scaphoid fracture was performed at our institution between 2014 and 2017. Medical records and radiographs were evaluated to determine lunate morphology, scaphoid fracture location, treatment, and time to union. Differences between groups were determined using χ² analysis with significance set at P <.05. Multiple logistic regression analyses were used to evaluate scaphoid union in the setting of lunate morphology when controlling for confounders. Results: A total of 169 patients were included; 45.0% (n = 76) of patients had type I lunate morphology, and 55.0% (n = 93) had type II. In all, 64.5% (n = 49) of patients with type I lunate and 68.8% (n = 64) with type II lunate had a fracture at the scaphoid waist. Among all patients with a scaphoid fracture, type II lunates were more likely than type I lunates to progress to nonunion when treated both operatively and nonoperatively (18.3% vs 4.0%, P = .0042). Lunate facet size was not shown to be a significant risk factor for nonunion among patients with a type II lunate (P = .4221). Conclusions: Patients with a scaphoid fracture and type II lunate morphology were more likely to progress to nonunion than patients with a type I lunate.

Kienböck Disease in a 66-Year-Old Man after Distal Ulna Fracture

Kienböck disease after fracture-dislocations around the wrist is a rare occurrence. This case report presents a case of a 66-year-old man who developed Kienböck disease 18 months after his distal ulnar fracture. The patient developed negative ulnar variance after union of the distal ulnar fracture. Nonsurgical treatment was not effective in relieving his pain. Radial shortening osteotomy was performed based on the negative ulnar variance that developed. One year postoperatively, visual analog scale improved to 0, grip strength improved to 25 kg, and flexion-extension arc improved to 150 degrees. The patient achieved satisfactory clinical outcomes. This is a therapeutic level IV study.

Outcomes following Distal Radius Fractures with Preexisting Ulnocarpal Abutment

Background  Due to the commonality of distal radius fractures (DRFs), the potential impact of ulnocarpal abutment (UA) on patient outcomes is significant, whether it developed after or prior to injury. It is, therefore, important to consider whether preexisting UA has any impact on outcomes after an acute DRF. Questions/Purpose  The aims of this study were to determine if differences were present in (1) pain at final follow-up, (2) complications, and (3) unintended operations in patients with DRFs and either without or with preexisting radiographic UA. Methods  A single institution retrospective cohort study comparing patients treated either nonoperatively (43 patients) or operatively (473 patients) for DRFs between 5/1/2008 to 5/1/2018 was performed. Data included demographics, prior wrist pain or surgery, ulnar variance, select treatment data, and presence of pain, complication, or unintended operation by final follow-up. Statistical testing used Fisher's exact test and chi-squared test, with a significance level of 0.05. Results  The prevalence of preexisting UA was 14.0 and 15.6% in the nonoperatively- and operatively treated groups, respectively. In nonoperatively treated patients without or with UA, no differences in pain (37.8 vs. 33.3%, p  = 1.00) or complications were seen (13.5 vs. 50.0%, p  = 0.07). A higher unintended operation rate for nonoperatively treated DRFs with UA, compared with those without, UA was seen (5.4 vs. 50.0%, p  = 0.01). No differences in pain, complications, or unintended operations were seen between those without and with UA in the operatively treated group. Conclusion  Preexisting UA is not associated with pain, complications, or unintended operations after operative treatment of DRFs. Prospective studies further evaluating outcomes in nonoperatively treated DRFs with UA may be beneficial.

Avascular necrosis of the lunate secondary to perilunate fracture dislocation: Case report and review of the literature

This is a 39-year-old male, fell from a bike, left wrist with trans-styloid perilunate fracture dislocation that underwent open reduction internal fixation, 20 months after surgery the patient developed avascular necrosis of the lunate, final wrist fusion was performed secondary to the arthritic changes on the wrist. Anatomic dissection was performed and vascularity of the lunate was identified, its origin is from the volar palmar arch, when dislocated palmarly and more than 90 degrees the vessel is still intact. More than 512 patients with perilunate dislocation and perilunate fracture dislocation are included we identified in the literature transient avascular necrosis of the lunate in nine and seventeen of pure avascular necrosis of the lunate. Concluding that avascular necrosis of the lunate after perilunate dislocation or perilunate fracture dislocation is an infrequent finding especially when the volar ligaments are intact.

The three-dimensional shape symmetry of the lunate and its implications

We studied the three-dimensional (3-D) shape variations and symmetry of the lunate to evaluate whether a contralateral shape-based approach to design patient-specific implants for treatment of Kienböck's disease is accurate. A 3-D statistical shape model of the lunate was built using the computed tomography scans of 54 lunate pairs and shape symmetry was evaluated based on an intraclass correlation analysis. The lunate shape was not bilaterally symmetrical in (1) the angle scaphoid surface - radius-ulna surface, (2) the dorsal side and the length of the side adjacent to the triquetrum, (3) the orientation of the volar surface, (4) the width of the side adjacent to the scaphoid, (5) the skewness in the coronal plane and (6) the curvature of bone articulating with the hamate and capitate. These findings suggest that using the contralateral lunate to design patient-specific lunate implants may not be as accurate as it is intended.

Volar Tilt of the Lunate After Open Reduction Internal Fixation of a Distal Radius Fracture

The pathophysiology of carpal adaptations after fracture of the distal radius is incompletely understood. We report 5 patients who had normal carpal alignment on injury radiographs that developed marked volar angulation of the lunate during recovery from volar plate fixation of a fracture of the distal radius. There were no signs of alteration of the carpal ligaments. Two patients had similar volar tilt on the contralateral side. The cause and optimal treatment of carpal malalignment after restoration distal radial alignment are unclear.

Long-Term Outcome of Surgical Treatment for Kienböck Disease Using an Articular-Based Classification

PURPOSE

The aim of this study was to report the outcomes of surgery using the Bain and Begg articular-based classification for the treatment of Kienböck disease.

METHODS

We identified and followed patients who had surgery for Kienböck disease between 1995 and 2014. Assessment included functional scoring using a modification of the Gartland and Werley score, pain levels, and grip strength.

RESULTS

Thirty-one patients were operated on for Kienböck disease between 1995 and 2014. Twenty-seven patients were assessed (12 men and 15 women). Mean age at the index procedure was 45.1 years (range, 20-82 years). Median follow-up after the index procedure was 10 years (range, 2-18 years). On the Bain and Begg classification, 5 patients had grade 0, 4 had grade 1, 5 had grade 2a, 10 had grade 2b, 1 had grade 3, and 1 had grade 4. The median pain visual analog scale improved from a preoperative score of 5 (interquartile range [IQR], 5-6) to a postoperative score of 2 (IQR, 0-3). The median functional scores from the modified Gartland and Werley score improved from 67 (IQR, 57.0-78.5) to 97 (IQR, 90.0-97.0). Eighteen out of 20 working patients returned to the same level of work. There was a significant improvement in power grip and tip pinch following surgery. One patient required a secondary salvage procedure. No patient required a full wrist fusion or arthroplasty.

CONCLUSIONS

This study confirms that the Bain and Begg arthroscopic classification and an articular-based approach to Kienböck disease provide a high probability of good long-term relief of pain and a minimal chance of requiring a salvage procedure.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

There is motion between the scaphoid and the lunate during the dart-throwing motion

Scaphoid and lunate mobility has been suggested to be minimal during the dart-throwing motion in studies based on serial computed tomography (CT) scans and cadaver studies. This study analyzes the direct motion between the scaphoid and the lunate during the dart-throwing motion in vivo. We examined nine individuals with standard CT scans of the wrist in radial extension and ulnar flexion. The paired CT scans were analyzed with a volume registration technique. The lunate was registered as fixed and the scaphoid as the mobile element. The motion of the scaphoid relative the lunate between the positions of radial extension and ulnar flexion was measured. There was considerable motion between the scaphoid and the lunate with both a distal to proximal translation and rotation during the dart-throwing motion, regardless of whether the scapholunate ligament was intact or not. These results suggest that aggressive dart-throwing exercises should not be implemented early on during rehabilitation following scapholunate repair.

Limited Carpal Fusion in Kienböck's Disease: Early Results following Scaphocapitate Arthrodesis

Background  Kienböck's disease leading to progressive carpal collapse alters the wrist biomechanics leading to early arthritis and degenerative changes. Out of multiple surgical procedures present, no gold standard has been described. Scaphocapitate arthrodesis (SCA) is limited carpal fusion which shifts the loading axis toward radioscaphoid joint. This study presents the midterm clinical and radiological results of SCA in Kienböck's disease. Materials and Methods  The data were reviewed from January 2016 to December 2017. Lichtman's classification used to stage the disease. Clinical variables were noted for wrist range of motion, grip strength, visual analog scale (VAS) score, quick disabilities of the arm, shoulder, and hand (quickDASH), and patient-rated wrist evaluation (PRWE) scores. Radiographs were evaluated for union, ulnar variance, carpal height ratio, radioscaphoid angle, and scapholunate angle. Results  A total of 11 patients of Stage IIIA and IIIB Kienböck's disease with mean age of 24 years were included in the study with a minimum of 18 months of clinical follow-up. The procedure resulted in decreased ranges of motion but improved grip strength (26.09 ± 4.76 from 19.54 ± 4.63 kgf) and reduced pain with VAS score decreased from 7.36 ± 0.8 to 2 ± 1. Radiographic analysis showed union in all patients, reduced carpal height with a corrected radioscaphoid angle (from 62.12 to 48.3 degrees), and scapholunate angle (from 34 to 26.27 degrees). Discussion  SCA has advantage of technical ease of orientation of the scaphoid and osteosynthesis of only one intercarpal joint with a large contact surface. Coupling the distal and proximal carpal rows results in significant loss of mean wrist range of motion but with improved grip strength, shifting the load away from the radiolunate joint. However, long-term studies are needed for clinical benefits and radiographic signs of radioscaphoid arthritis for the treatment of advanced-stage Kienböck's disease. Level of Evidence  This is a Level IV, retrospective observational study.

Satisfactory function 12 years after triscaphoid arthrodesis for chronic scapholunate ligament injury

Scapholunate ligament (SLL) injury represents a hazard to the wrist and the treatment of these injuries has been the focus of much debate. We performed a long-term follow (>10 years) of triscaphoid arthrodesis for symptomatic chronic SLL injuries in 10 (8 men) patients 37 (22-49) years of age. All arthrodesis healed. One patient was converted to total wrist arthrodesis during the follow-up period, and three had minor additional surgeries. At final follow-up, the patients had reduced active range of motion (AROM, 55%) and grip strength (85%) compared to the opposite side, but reported low Quick Disability of Arm, Shoulder and Hand (QDASH) (11), Patient-Rated Wrist and Hand Evaluation (PRWHE) (25) and visual analog scale (VAS) pain scores (0 and 10 at rest and activity). Radiographs found minimal degenerative changes in four patients, while CT scans demonstrated changes in seven patients, in three of these scaphoid was subluxed on the rim of the radius. The patients working prior to surgery were working at follow-up. A triscaphoid arthrodesis for SLL renders a functional wrist function in most patients for many years and has postponed more extensive surgery like total wrist arthrodesis or wrist arthroplasty. The patients are still young, and the degenerative changes seen especially on CT scans warrants attention.

Relationship of Plasminogen Activator Inhibitor 1 4G/5G Gene Polymorphism and Nontraumatic Lunatum Avascular Necrosis

PURPOSE

Plasminogen activator inhibitor 1 (PAI-1) is a critical enzyme that regulates coagulation and fibrinolytic systems. The aim of this study was to determine the role of PAI-1 4G/5G polymorphism in nontraumatic avascular necrosis of the lunate.

METHODS

The study included 45 patients with Kienböck disease and 45 healthy individuals as a control group. In both groups, genomic DNA was extracted from peripheral blood samples to determine the distributions of PAI-1 4G/5G polymorphism using allele-specific polymerase chain reaction and sequencing.

RESULTS

No statistically significant difference was determined in the distribution of the gene polymorphism between the patient and control groups. We found the 5G/5G genotype to be 1.7 times higher in the control group compared with the patient group. A 1.6-fold increase in the 4G homozygote genotype was identified in the patient group. The patient and control groups were also evaluated for 4G/4G plus 4G/5G and 5G/5G in terms of genotype distribution. No statistically significant difference was found.

CONCLUSIONS

The findings suggest that the PAI-1 4G/4G polymorphism is not a genetic risk for Kienböck disease.

CLINICAL RELEVANCE

This study aimed to reveal the genetic etiology of Kienböck disease.

Functional and radiological results of partial capitate shortening osteotomy in the treatment of Kienböck's disease

This study assessed the functional and radiological results of partial capitate shortening osteotomy in the treatment of Lichtman stage 2 and 3A Kienböck's disease. Nineteen patients who underwent partial capitate shortening osteotomy between 2014 and 2017 were included. Functional and radiological parameters were assessed both pre- and postoperatively. The mean age was 35 years and the mean follow-up was 16 months. Pain scores, wrist range of motion, hand and finger strength, carpal height ratio and lunate height were significantly improved compared with their preoperative values. Sixteen patients were able to return to work. Ten of them had complete and six had partial revascularization. The mean time taken to return to work was 62 days. No vascularity was achieved in three patients who were unable to return to work. Partial capitate shortening osteotomy is effective in the treatment of stage 2 and 3A Kienböck's disease with successful results both functionally and radiologically. Level of evidence: IV.

Pronator quadratus pedicled bone graft in the treatment of Kienböck disease: follow-up 2 to 12 years

We inserted a pronator quadratus pedicled bone graft into the avascular lunate with preservation of its corticocartilaginous portion for the treatment of Kienböck disease. Twenty-seven patients (14 men, 13 women; mean age, 42 years (range 17-66 years)) were treated between September 2005 and July 2014 and followed up from 2 to 12 years. Three patients had Lichtman stage II disease, 13 had stage IIIA, and 11 had stage IIIB. Among them, 18 patients showed radiological improvement in lunate morphology. The Lichtman stage was unchanged in 23 patients and aggravated in four patients. The Stahl index was significantly decreased, but grip strength was significantly improved and 18 patients did not have any wrist pain during daily activities. Although our technique did not restore the already changed carpal malalignment, it improved lunate morphology. Clinically, it provided satisfactory pain levels in two-thirds of the patients and grip strength was improved. Level of evidence: IV.

Analysis of Radiographic Relationship between Distal Radius, Ulna, and Lunate

Background  Wrist anatomy variability is associated with differing susceptibility to pathology. For example, a flat radial inclination is associated with Kienbock's disease. Lunate facet inclination (LFI) also exhibits variability. Its relationship with other wrist features is poorly documented. Purposes  We tested the hypothesis that high LFI is associated with increased uncovering of the lunate, negative ulnar variance (UV), and type 2 lunates to balance forces across wrists. Methods  In total, 50 bilateral and 100 unilateral wrist posteroanterior radiographs were reviewed. Lunate type, lunate uncovering index (LUI), lunate tilting angle (LTA), UV, and sigmoid notch angle (SNA) were measured, and correlation with LFI was assessed on 150 right wrist radiographs followed by an assessment of differences based on lunate morphology. Symmetry of 50 bilateral wrists was assessed. Results  There was no correlation of LFI with lunate morphology, LUI, and LTA. There was a low correlation of LFI with SNA and UV. There was an inverse relationship between UV and SNA. Wrists with type 2 lunates had more oblique sigmoid notches and higher LTA in comparison to wrists with type 1 lunates. Side-to-side comparison revealed strong correlation except for LUI, which exhibited moderate correlation. Conclusions There is no correlation between LFI, LUI, and lunate morphology. Type 2 lunates are associated with higher LTA and more oblique SNA. Wrists were symmetrical. Clinical Relevance  Factors other than lunate morphology are essential in balancing forces across wrists. A better understanding of soft tissue and other factors will improve the understanding of wrist biomechanics and pathology. Contralateral wrist radiographs can guide reconstructive surgery.

Differences in the Rotation Axes of the Scapholunate Joint During Flexion-Extension and Radial-Ulnar Deviation Motions

PURPOSE

To determine the location of the rotation axis between the scaphoid and the lunate (SL-axis) during wrist flexion-extension (FE) and radial-ulnar deviation (RUD).

METHODS

An established and publicly available digital database of wrist bone anatomy and carpal kinematics of 30 healthy volunteers (15 males and 15 females) in up to 8 different positions was used to study the SL-axis. Using the combinations of positions from wrist FE and RUD, the helical axis of motion of the scaphoid relative to the lunate was calculated for each trial in an anatomical coordinate system embedded in the lunate. The differences in location and orientation between each individual axis and the average axis were used to quantify variation in axis orientation. Variation in the axis location was computed as the distance from the closest point on the rotation axis to the centroid of the lunate.

RESULTS

The variation in axis orientation of the rotation axis for wrist FE and RUD were 84.3° and 83.5°, respectively. The mean distances of each rotation axis from the centroid of the lunate for FE and RUD were 5.7 ± 3.2 mm, and 5.0 ± 3.6 mm, respectively.

CONCLUSIONS

Based on the evaluation of this dataset, we demonstrated that the rotation axis of the scaphoid relative to the lunate is highly variable across subjects and positions during both FE and RUD motions. The range of locations and variation in axis orientations in this data set of 30 wrists shows that there is very likely no single location for the SL-axis.

CLINICAL RELEVANCE

Scapholunate interosseous ligament reconstruction methods focused on re-creating a standard SL-axis may not restore what is more likely to be a variable anatomical axis and normal kinematics of the scaphoid and lunate.

Closed Limb Fractures With Compromised Vascularization: A Narrative Review

Vascular compromised fractures typically result in a high rate of healing complications, such as avascular necrosis, nonunion, delayed union, and arthritis, which severely affect a patient's function and quality of life. The purpose of this review was to identify and describe the epidemiology and available treatment options for the most well-known vascular compromised closed fractures. The injuries discussed in detail in this review were scaphoid, lunate, femoral neck, and talar fractures. Current evidence suggests that optimal treatment for vascular compromised fractures is dependent on the degree of fracture displacement and comminution, and the patient's post-injury functional demands, age, and bone quality. Conservative efforts generally include casting or splinting with a period of immobilization. Surgery is indicated for substantially displaced fractures, patients who require higher functional demands and an earlier return to activity, or if complications occur following nonoperative treatment; however, operative intervention is typically performed for femoral neck fractures regardless of the amount of displacement. Various surgical techniques exist, though internal fixation with screws is a common procedure among these injuries and can be used in combination with other implants, such as plating or Kirschner wires (k-wires), when needed. Severe fracture comminution, poor bone quality, or arthritis can contraindicate the use of screws and more invasive intervention will be required. Bone grafting is done in some cases to enhance vascularity. Salvage procedures exist for patients who develop severe complications, but these will permanently alter the anatomy of the injured area and should be considered a last resort.

Partial Capitate Shortening Osteotomy and Its Impact on Lunate Revascularization: Mid-Term Results

Background

Treatment of Kienböck disease is still a clinical challenge. The treatment used in each instance is decided according to stage of the disease at presentation. Good clinical and radiological results could be obtained with partial capitate shortening osteotomy. However, mid-term results of this technique and its effect on lunate revascularization are not well known.

Objectives

The aim of this study was to report our results of partial capitate shortening osteotomy in the treatment of stage II and IIIA Kienböck disease.

Methods

Ten patients were enrolled in the study with a mean age of 37.7 years old (standard deviation [SD] = 9.6). Patients were evaluated clinically in terms of range of motion, DASH and VAS scores, satisfaction with the outcome, and grip/tip/palmar/key pinch strength compared to the contralateral side. Radiological evaluation consisted of Lichtman staging on plain radiographs and lunate revascularization on magnetic resonance imaging (MRI) at both preoperative and postoperative evaluations.

Results

The mean duration of follow-up was 55.2 (SD = 24) months. The mean DASH and VAS scores were 14.3 (SD = 6.7) and 1.5 (SD = 1.3), respectively. For patient satisfaction, the mean score was 3.6 (SD = 0.6). The Lichtman stage of 7 patients remained unchanged. Lunate revascularization was detected with MRI in 6 patients.

Conclusions

Although the number of patients in the study prevents more strict conclusions, our results are promising, and the technique presented offers minimally but observable lunate revascularization and high success rates in preventing the progression of the disease.

Increased perfusion in dynamic gadolinium-enhanced MRI correlates with areas of bone repair and of bone necrosis in patients with Kienböck's disease

BACKGROUND

Osteonecrosis of the lunate, Kienböck's disease, can lead to fragmentation of the lunate, carpal collapse, and severe osteoarthritis. Since the etiology of Kienböck's disease is impaired circulation, a diagnostic method capable of assessing perfusion would be valuable. Recent studies have suggested that dynamic contrast-enhanced (DCE) MR examinations at 3 T can assess perfusion in healthy carpal bones.

PURPOSE

To evaluate the use of DCE-MR for assessing perfusion in the lunate bone in patients with Kienböck's disease. Furthermore, to compare perfusion with histopathology with a focus on bone viability.

STUDY TYPE

Prospective case-control study.

POPULATION

Fourteen patients with Kienböck's disease and a control group of 19 healthy subjects. Field Strength: 3 T with T₁ -weighted fat-saturated contrast-enhanced gradient echo series.

ASSESSMENT

Features of the enhancement curves from the DCE-MR examinations, time to peak (TTP), maximum slope (MS), and maximum enhancement (ME) assessed by a radiologist. Six of 14 patients were surgerized with lunate excision, allowing comparison between features of the enhancement curves and histopathology.

STATISTICAL TESTS

Mann-Whitney U-test. P < 0.05 was considered a statistically significant difference.

RESULTS

Patients with Kienböck's disease showed significantly higher and faster perfusion parameters compared with the control group, the mean value of the TTP in patients was 126.73 sec, in controls 189.79 sec (P = 0.024), ME in patients 173.55 AU, in controls 28.46 AU (P < 0.001), and MS in patients 5.04 AU, in controls 1.06 AU (P < 0.001). When compared with histopathology, increased perfusion was seen in areas of bone formation but also in necrosis. Areas of normal bone showed low perfusion.

DATA CONCLUSION

DCE-MRI at 3 T can diagnose altered perfusion in patients with Kienböck's disease. Increased perfusion cannot definitely be used as a marker of bone viability.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:481-489.

Changes in Scaphoid and Lunate Position and Loading at Two Wrist Pushup Positions

BACKGROUND

Scapholunate interosseous ligament (SLIL) injury following a fall on an outstretched hand may lead to carpal instability and in some cases require long-term rehabilitation following repair. Rehabilitation, especially in athletes, may include pushups, but little is known as to what type of pushup may be safer.

OBJECTIVE

To determine biomechanical differences between two pushup positions (neutral or extended).

METHODS

Six fresh cadaver wrists with pre-existing SLIL damage were uni-axially loaded in neutral and extension in order to simulate two different pushup styles. The motions of the scaphoid and lunate in relation to the radius were measured. The dorsal, proximal, and volar insertion sites of the SLIL were identified and, using the collected kinematic data, gap distances were calculated for each site.

RESULTS

Gap distance between the proximal SLIL insertion points was significantly greater in neutral than in extension. There was a trend that the dorsal and volar SLIL insertion points were also greater in neutral than in extension. After the wrist was extended 90o, the scaphoid extended 70.1o and the lunate extended 28.6o compared to their positions with the wrist in neutral.

CONCLUSION

The larger gap distances between the scaphoid and lunate in neutral suggest that a neutral style pushup could put higher forces on a wrist with pre-existing SLIL damage and may thus hinder recovery for a person with a repaired SLIL. A pushup in extension, in these injured wrists, may be less detrimental.

Capitate and Lunate Morphology in Normal Wrist Radiographs-A Pilot Study

BACKGROUND

Morphology may provide the basis for the understanding of wrist mechanics.

METHODS

We used classification systems based on cadaver dissection of lunate and capitate types to evaluate a normal database of 70 wrist radiographs in 35 subjects looking for associations between bone shapes. Kappa statistics and a log-linear mixed -effects model with a random intercept were used.

RESULTS

There were 39 type-1, 31 type- 2 lunates, 50 spherical, 10 flat and 10 V-shaped capitates. There was a significant difference in lunate and capitate shape between the hands of the same individual p <0.001. This may be due to different loads on the dominant vs. nondominant hands in the same individual.

CONCLUSION

Further study to better understand the development of radiographic parameters of the midcarpal joint may aid in our understanding of the morphology and mechanics of the wrist.

Carpal Pronation and Supination Changes in the Unstable Wrist

Background  Little is known about changes in scaphoid and lunate supination and pronation following scapholunate interosseous ligament (SLIL) injury. Information on these changes may help explain why some SLIL reconstructions have failed and help in the development of new techniques. Purpose  To determine if following simulated SLIL injury there was an increase in scaphoid pronation and lunate supination and to determine if concurrently there was an increase in the extensor carpi ulnaris (ECU) force. Materials and Methods  Scaphoid and lunate motion were measured before and after sectioning of the SLIL and two volar ligaments in 22 cadaver wrists, and before and after sectioning of the SLIL and two dorsal ligaments in 15 additional wrists. Each wrist was dynamically moved through wrist flexion/extension, radioulnar deviation, and a dart-throwing motion. Changes in the ECU force were recorded during each wrist motion. Results  Scaphoid pronation and lunate supination significantly increased following ligamentous sectioning during each motion. There were significant differences in the amount of change in lunate motion, but not in scaphoid motion, between the two groups of sectioned ligaments. Greater percentage ECU force was required following ligamentous sectioning to achieve the same wrist motions. Conclusion  Carpal supination/pronation changed with simulated damage to the scapholunate stabilizers. This may be associated with the required increases in the ECU force. Clinical Relevance  In reconstructing the SLIL, one should be aware of the possible need to correct scaphoid pronation and lunate supination that occur following injury. This may be more of a concern when the dorsal stabilizers are injured.

Morphological Associations between the Distal Radioulnar Joint and the Lunate

Background  Variations in morphology of the carpal bones have been described. Their implication in wrist disease and specific kinematic features has been recognized, and a better knowledge of these variations is essential. Questions/Purpose  To radiographically determine any association between the morphological variations of the distal radioulnar joint (DRUJ) and the lunate bone. Materials and Methods  Radiographs of 100 wrists of patients presenting to the emergency department with wrist pain and referred to our outpatient clinic were retrospectively reviewed for DRUJ inclination, ulnar variance, and radiocarpal and midcarpal morphology of the lunate. Results  There were 51 females and 49 males, mean age 51.2 years (range: 21-94). There was a statistically significant association between the DRUJ inclination and the morphology of the radiocarpal side of the lunate ( p  < 0.001). The mean values of ulnar variance changed according to DRUJ inclination and the radiocarpal side of the lunate ( p  < 0.001) but not according to the midcarpal side of the lunate. There was no significant association between the morphology of the DRUJ and the midcarpal side of the lunate or between the midcarpal and the radiocarpal morphology of the lunate. Conclusion  This study demonstrated a statistically significant association at the radiocarpal level between the DRUJ inclination, ulnar variance, and the morphology of the lunate. No association was found with the morphology of the midcarpal side of the lunate. Accordingly, a classification of these carpal associations is proposed, highlighting seven main wrist configurations. Clinical Relevance  These associations can guide future studies of wrist kinematics.

Medium-term outcome of closed radial wedge osteotomy of the distal radius for Preiser disease with concomitant Kienböck disease: Two case reports and a literature review

RATIONALE

Idiopathic avascular necrosis of the scaphoid or lunate bone are known as Preiser disease and Kienböck disease, respectively. Although there are reports of avascular necrosis involving more than one carpal bone, concurrent idiopathic avascular necrosis of the scaphoid and lunate bones is rare, with only five cases reported in the English literature (including the two herein). Although the optimum treatment for Preiser disease with concomitant Kienböck disease has not been established, our cases underwent closed radial wedge osteotomy based on the evidence of satisfactory outcomes for treating Kienböck disease. We report the medium-term results of closed radial wedge osteotomy of the distal radius in two cases of Preiser disease with concomitant Kienböck disease.

PATIENT CONCERNS

We presented two patients with concomitant Preiser and Kienböck diseases. Although both smoked cigarettes, neither had any other risk factors; there was no history of trauma, although both women had jobs that required relatively heavy or repetitive manual labor.

DIAGNOSES

Two patients were diagnosed by radiographs and magnetic resonance imaging of the wrists.

INTERVENTIONS

A non-surgical strategy of splint immobilization and analgesia was not effective, and surgery was ultimately required.

OUTCOMES

Satisfactory medium-term results were achieved with closed radial wedge osteotomy of the distal radius in both cases. Although there was imaging evidence of progression of dorsal intercalated segmental instability deformity, neither of the patients was symptomatic and both declined salvage surgery.

LESSONS

We compare our cases and treatment strategy with others reported in the literature. Our cases suggest that closed radial wedge osteotomy of the distal radius is a safe and relatively straightforward means of treating patients with this rare combination of wrist disorders, and appears to obviate the need for more extensive salvage procedures.

Radius Core Decompression for Kienböck Disease Stage IIIA: Outcomes at 13 Years Follow-Up

PURPOSE

This study was designed to analyze the long-term clinical and radiological outcomes of a series of patients with Kienböck disease stage IIIA treated with radius core decompression.

METHODS

This retrospective study included 15 patients with Kienböck disease (Lichtman stage IIIA) who underwent distal radius metaphyseal core decompression between 1998 and 2005 and who were followed-up for at least 10 years. At the last follow-up, the patients were evaluated for wrist range of motion and grip strength. The overall results were evaluated by the modified Mayo wrist score and visual analog scale pain score. We also compared the radiological changes between the preoperative and the final follow-up in their Lichtman classification and the modified carpal height ratio.

RESULTS

The mean follow-up period was 13 years (range, 10-18 years). Based on the modified Mayo wrist score, clinical results were excellent in 6 patients, good in 8 patients, and poor in 1 patient who required a proximal row carpectomy as revision surgery. The mean preoperative pain according to the visual analog scale was 7 (range, 6-10) and was 1.2 (range, 0-6) at the final follow-up. Compared with the opposite side, the average flexion/extension arc was 77% and the grip strength was 80%. All patients, except 1, returned to their original employment. At the final follow-up, 3 patients had decreased modified carpal height ratio, 12 remained unchanged. Radiographic disease progression according to the Lichtman classification to stages IIIB to IV occurred in only 2 wrists. There were no complications related to the core decompression.

CONCLUSIONS

In this limited series, the radius core decompression demonstrated favorable long-term results and could be considered as a surgical alternative for stage IIIA of Kienböck disease.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Biomechanical Evaluation of Carpal Kinematics during Simulated Wrist Motion

Background Flexion and extension of the wrist is achieved primarily at the radiocarpal and midcarpal joints. Carpal kinematics have been investigated, although there remains no consensus regarding the relative contribution of each bone to wrist motion. Purpose To determine the kinematics of the scaphoid, lunate, and capitate during unconstrained simulated wrist flexion/extension and to examine the effect of motion direction on the contribution of each bone. Materials and Methods Seven cadaveric upper extremities were tested in a passive wrist simulator with 10N tone loads applied to the wrist flexors/extensors. Scaphoid, lunate, and capitate kinematics were captured using optical tracking and analyzed with respect to the radius. Results Scaphoid and lunate motion correlated linearly with wrist motion (R² = 0.99, 0.97). In extension, the scaphoid and lunate extended 83 ± 19% and 37 ± 18% relative to total wrist extension (p = 0.03, 0.001), respectively. In flexion, the scaphoid and lunate flexed 95 ± 20% and 70 ± 12% relative to total wrist flexion (p = 1.0,0.01) , respectively. The lunate rotated 46 ± 25% less than the capitate and 35 ± 31% less than the scaphoid. The intercarpal motion between the scaphoid and lunate was 25 ± 17% of wrist flexion. Conclusion The scaphoid, lunate, and capitate move synergistically throughout planar wrist motion. The scaphoid and lunate contributed at a greater degree during flexion, suggesting that the radiocarpal joint plays a more critical role in wrist flexion. Clinical Relevance The large magnitude of differential rotation between the scaphoid and lunate may be responsible for the high incidence of scapholunate ligament injuries. An understanding of normal carpal kinematics may assist in positioning carpal bones during partial wrist fusions and in developing more durable wrist arthroplasty designs.

Flexor Tendon Rupture Due to Previously Undiagnosed Kienböck Disease: A Case Report

BACKGROUND

Spontaneous flexor tendon rupture is rare and most common in the little finger. The pathogenesis of spontaneous tendon ruptures is unclear but may occur through attrition or mechanical abrasion over a bony prominence. Kienböck disease is avascular necrosis of the lunate, with an unknown etiology.

METHODS

We present a case of spontaneous rupture of flexor digitorum profundus due to Kienböck disease, which we believe is the first recorded case of flexor tendon rupture attributable to osteonecrosis of the lunate.

RESULTS

The patient underwent single-stage reconstruction of FDP and regained a good range of motion at the affected DIPJ.

CONCLUSIONS

This case illustrates the the importance of plain radiographs in the assessment of a patient presenting with spontaneous flexor tendon rupture in the hand to exclude bony pathology as a cause.

Kienböck Disease: A New Algorithm for the 21st Century

Background It has been over 100 years since the initial description of avascular necrosis of the lunate. Over the last two decades, there has been the introduction of advanced information regarding the etiology, natural history, classification, and treatment options for lunate osteonecrosis. There have been new classifications developed based on advanced imaging, perfusion studies of lunate viability, and arthroscopic assessment of the articular cartilage. Purpose This article brings together a new treatment algorithm, incorporating the traditional osseous classification system (Lichtman) with the perfusion/viability classification (Schmitt) and the articular cartilage classification (Bain). Methods We have developed a new algorithm to manage Kienböck avascular necrosis of the lunate. This new algorithm incorporates the current concepts of the diseased lunate and its effects on the remainder of the wrist. Conclusion For patients with a good prognosis and in the earliest stages, the "intact lunate" is initially protected utilizing nonoperative measures. If this fails, then appropriate lunate unloading procedures should be considered. If the lunate is "compromised" then it can be reconstructed with a medial femoral condyle graft or proximal row carpectomy (PRC). With the further collapse of the lunate, the wrist is then also compromised, with the development of secondary degeneration of the central column articulation. The "compromised wrist" will have functional articulations, which allows motion-preserving procedures to be utilized to maintain a functional wrist. With advanced disease (Kienböck disease advanced collapse), the wrist is not reconstructable, so only a salvage procedure can be performed. Other than these objective pathoanatomical factors, the final decision must accommodate the various patient factors (e.g., age, general health, lifestyle, financial constraints, and future demands on the wrist) and surgeon factors (skill set, equipment, and work environment).

Microstructural study of the lunate in stage III Kienböck's disease with micro-computed tomography imaging

Seventeen fresh lunates with stage III Kienböck's disease were scanned with micro-computed tomography. Four regions of interest were selected to measure trabecular parameters, which were compared with those from normal lunates. Within the three regions in the distal surface, there was more compact trabecular bone in the middle region when compared with the palmar and dorsal regions. In the central part, the trabeculae of the Kienböck's lunates were much thicker than those in normal lunates. The diameters of the palmar nutrient foramina of the Kienböck's lunates were significantly smaller than those in normal lunates. In affected lunates, the bony disruptions were mostly located in the palmar or dorsal areas, which were shown from trabecular bone structure analysis to be structurally weaker. This leads to separation of the distal part of the fractured bone, disruption of the blood supply, poor bone remodelling and proneness to secondary fracture and eventual collapse.

The Etiology and Pathogenesis of Kienböck Disease

Kienböck disease is a condition that typically occurs in the "at-risk" patient, in the "at-risk" aspect of the proximal condyle of the "at-risk" lunate. In the active male, repetitive loading causes the stress fracture that commences in the single layer proximal subchondral bone plate. The lunate fracture commences at the point the lunate cantilevers over the edge of the distal radius, and then takes on the shape of the radius. We postulate that the stress fracture violates the parallel veins of the venous subarticular plexus-leading to localized venous hypertension and subsequent ischemia and edema of the fatty marrow. The increased osseous compartment pressure further potentiates the venous obstruction, producing avascular necrosis. If the fracture remains localized, it can heal or settle into a stable configuration, so that the wrist remains functional. Fractures of the subchondral bone plate produce irregularity of the lunate articular surfaces and secondary "kissing lesions" of the lunate facet and capitate, and subsequent degeneration. The lunate collapses when the fracture is comminuted, or there is disruption of the spanning trabeculae or a coronal fracture. The secondary effect of the lunate collapse is proximal migration of the capitate between the volar and dorsal fragments, producing collapse of the entire central column. The proximal carpal row is now unstable, and is similar to scapholunate instability, where the capitate migrates between the scaphoid and lunate. The scaphoid is forced into flexion by the trapezium, however, degeneration of the scaphoid and scaphoid facet only occurs in late disease or following failed surgery. In Kienböck disease, the secondary effects of the collapsing lunate are a "compromised" wrist, including: deformity and collapse of the central column, degeneration of the central column (perilunate) articulations, proximal row instability (i.e., between the central and radial columns), and degeneration of the radial column.

Bilateral Legg-Calve-Perthes Disease and Kienbock's Disease in a Child With Factor V Leiden Thrombophilia: A Case Report

Background: The etiology of multifocal osteonecrosis is not definitively known; however, hypercoagulable state is a very plausible cause. Methods: We present an unusual case of a 12-year-old boy with a history of Legg-Calve-Perthes disease presenting with right wrist pain who was subsequently diagnosed with Kienbock's disease. The finding of multifocal osteonecrosis prompted testing for a hypercoagulable state that was positive for Factor V Leiden thrombophilia. A thorough literature review using Medline database was conducted to investigate associations between inherited hypercoagulable states and multifocal osteonecrosis. Results: Our literature review identified 2 similar cases of multifocal osteonecrosis associated with a hypercoagulable disorder in adult patients. There were no reports among the pediatric patient population. Meta-analysis has demonstrated a potential link between Legg-Calve-Perthes disease and Factor V Leiden thrombophilia. Conclusions: This study offers further evidence to support the theory that multifocal osteonecrosis may be linked to a hypercoagulable state. Patients presenting with multifocal osteonecrosis should undergo screening for hypercoagulable states. Further investigation is needed to ascertain the potential benefit of prophylactic anticoagulation in patients with a known hypercoagulable state and multifocal osteonecrosis.

Microstructural study of the lunate in stage III Kienböck's disease with micro-computed tomography imaging

Seventeen fresh lunates with stage III Kienböck's disease were scanned with micro-computed tomography. Four regions of interest were selected to measure trabecular parameters, which were compared with those from normal lunates. Within the three regions in the distal surface, there was more compact trabecular bone in the middle region when compared with the palmar and dorsal regions. In the central part, the trabeculae of the Kienböck's lunates were much thicker than those in normal lunates. The diameters of the palmar nutrient foramina of the Kienböck's lunates were significantly smaller than those in normal lunates. In affected lunates, the bony disruptions were mostly located in the palmar or dorsal areas, which were shown from trabecular bone structure analysis to be structurally weaker. This leads to separation of the distal part of the fractured bone, disruption of the blood supply, poor bone remodelling and proneness to secondary fracture and eventual collapse.

Carpal tunnel syndrome associated with Kienböck disease

We retrospectively reviewed 12 patients (3 men and 9 women, with a mean age of 72 years) who were surgically treated for carpal tunnel syndrome associated with Kienböck disease. All patients except 1 were incidentally diagnosed with Kienböck disease and had little or no wrist pain. Radiographic tests revealed advanced Kienböck disease in all patients. Intraoperative findings indicated that the site of maximum compression on the median nerve was located at the level of the carpal tunnel inlet in 11 patients, and the volar dislocated fragment of the lunate was located proximally adjacent to the floor of the carpal tunnel inlet. This disorder is most prevalent in elderly women, and even advanced Kienböck disease can present without wrist pain. Our findings suggest that palmar protrusion of the lunate may be the primary cause of carpal tunnel syndrome associated with Kienböck disease.

Kuhlmann vascularized bone grafting for treatment of Kienböck's disease: a case report

Treatment of Kienböck's disease has historically been determined by staging, ulnar variance, and presence or absence of arthritic changes. With the advent of newer techniques of vascularized bone grafting, the status of the cartilage shell of the lunate has become another factor that can influence the procedure performed. The purpose of this article is to describe the technique of Kuhlmann vascularized bone graft for Kienböck's disease. In addition, the indications, contraindications, and outcomes are described.

In Vivo High-Resolution Trabecular Microstructure of Kienböck Lunate before and after Radial Shortening: A Case Report

We report a patient with stage IIIB Kienböck disease treated with radial shortening where preoperative and sequential postoperative imaging were done using in vivo high-resolution peripheral quantitative micro-computed tomography (micro-CT) scan. Sequential in vivo micro-CT scan analysis of a target zone of the Kienböck lunate of this patient demonstrated early signs of lunate remodeling (bone trabecular densification) at 5-month follow-up suggesting an ongoing healing process. These early remodeling micro-CT scan signs were confirmed at 5 years' follow-up as well.

Kienböck Disease: Moving Forward

Over the past decade, a plethora of new information has been reported regarding etiology, natural history, classification, and treatment options for lunate osteonecrosis. New disease classifications have been described based on advanced imaging determination of lunate viability as well as a cartilage-based arthroscopic classification. Here we review the newest literature regarding Kienböck disease and present a new treatment algorithm that incorporates the traditional osseous classification system with a perfusion/viability classification and an articular cartilage-based classification.

Long-Term Outcomes of Radial Osteotomy for the Treatment of Kienböck Disease

Background Kienböck disease is an aseptic necrosis of the lunate of unknown etiology, prevalent in young adults. Treatment aims to lower forces on the lunate, decrease pain and improve function. We conducted a retrospective evaluation of the 10-year clinical and radiological outcomes of radial osteotomy as a treatment for Kienböck disease. Materials and Methods We analyzed pain, grip strength, wrist range of motion (ROM), radiological carpal geometry, and staging of osteoarthritic changes over a 10-year period, postosteotomy, for 18 patients. The Mayo wrist score was used as an overall measure of outcome. Technique Outcomes for two types of osteotomies were included, a step-cut osteotomy with fixed screws and an updated technique of two linear transverse osteotomies with volar locking plates. For cases with negative ulnar variance, resection of the radius was included to obtain a final ulnar variance of -1 to 0 mm. For positive ulnar variance, the goal was to obtain a correction of radial inclination of 10 to 15 degrees. Results Improvements in pain, ROM, and grip strength were maintained over the 10-year follow-up, without radiological improvement in geometry (carpal height ratio and Stahl index). Mild osteoarthritic changes were identified in 33% of patients, with no effect on clinical results. Degree of cartilage damage determined postoperative grip strength improvement. The Mayo wrist score at the final follow-up was excellent in one patient, good in nine, and fair in eight. Conclusions Radial osteotomy provides reasonable and long-term clinical benefits. Preoperative arthroscopic evaluation of cartilage damage can inform treatment decisions.