The anatomy and vascularity of the lunate: considerations applied to Kienböck’s disease

Vascular Supply of the Wrist

The vascular anatomy of the wrist is vital in the development of multiple disorders at the carpus. Understanding this vascular network may prevent iatrogenic injury to the blood supply and can be used by surgeons through vascularized bone grafts. Multiple surgical techniques take advantage of the vascular network. This article reviews the blood supply of the distal radius, ulna, and carpal bones and its clinical implications.

Kienbock's disease: A radiological case report

Kienböck's disease is a condition characterized by avascular necrosis of the lunate. It is also known as lunatomalacia and aseptic or ischemic necrosis of the lunate.

The aim of this work is to summarize and illustrate, through a case diagnosed in our institution, the radiological aspects of this rare entity, which occupy a prominent place in the diagnosis.

A better understanding of this recently described nosological entity and a wide dissemination of its diagnostic criteria, especially by radiologists, should facilitate the diagnosis and treatment of patients.

Kienböck's disease in 2021

The cause of Kienböck's disease is still unclear. It was initially considered as osteomalacia, before being recognized as avascular necrosis of the lunate. Its functional prognosis is doubtful, given that the progression often leads to wrist degeneration. Conservative treatment does not provide good results in adults; thus surgery is often needed. Certain anatomical factors such as the ulnar variance, configuration of the lunate or orientation of the radial glenoid have turned out not to contribute to necrosis but may contribute to lunate fracture. The lunate's vascularization can be precarious and mostly depends on the capsular arterioles. The lunate is a very mobile bone that participates in wrist movements, both in the radiocarpal joint and especially in the mid-carpal joints during activities of daily living. Radiographs are not the only diagnostic tools. The lunate makes contact with the radius and triangular fibrocartilage complex and is often subjected to high shear loads at the edge of the radius that can cause it to fracture. MRI and arthroscopy can contribute to the assessment. Kienböck's disease is likely an inflammatory, biological venous thrombosis disorder that leads to local damage due to intraosseous compartment syndrome. The basis of surgical treatment is to decompress the lunate to shield it from shear and compression loads. Existing osteotomy procedures will be described and compared to better understand their biomechanical effects. Some osteotomies do not reduce the loads transmitted to the lunate but can reduce the risk of intra-osseous shear. Some osteotomies may place excessive pressure on the lunate on its ulnar side. Some techniques are extra-articular and preserve the capsule's vascularization along with the anatomy of the mid-carpal joint. When the lunate damage is so severe that the bone's viability is compromised, bone grafting or replacement have been proposed. The palliative techniques typically used for wrist degeneration are indicated in the terminal stages. There are currently no effective biological treatments. While the origin of Kienböck's disease is still unknown, we now know that decompression osteotomies, while they do not heal the necrosis, protect the lunate from collapse, which hopefully provides enough time for biological healing to occur.

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.

Volar and Dorsal Blood Supply to the Lunate: A Cadaveric Study

Although various studies have proposed vascular and mechanical factors, the etiology of Kienböck disease is unknown. Kienböck theorized that lunatomalacia resulted from traumatic disruption of blood supply and bony nutrition to the lunate. Extraosseous supply to the lunate, as far as volar or dorsal vessels are concerned, is still controversial. This study evaluated the extraosseous nutrient foramina from the dorsal and volar aspects of lunate specimens. A total of 913 specimens from the Hamann-Todd Osteological Collection in Cleveland, Ohio, were examined. The nutrient artery foramina on left and right lunate specimens were examined from dorsal and volar aspects. The number of nutrient artery foramen was tabulated. Age, sex, and race data were collected. Specimens were divided into groups according to the number of nutrient artery foramina, and the dorsal and volar foramina were compared. The average number of foramina on the dorsal aspect of the lunate (1.71) was greater than the volar aspect (1.64), except in specimens younger than 35 years. A greater number of specimens had 3 or more foramina on the dorsal side compared with the volar aspect. Based on this study, there was significant contribution of dorsal arterial vessels to the blood supply of lunate specimens older than 35 years, which contrasts with findings in earlier studies. The disruption of dorsal intercarpal and radiocarpal ligaments leading to the disruption of the dorsal arterial arches may contribute to vascular insufficiency of the lunate and should be evaluated further in the etiopathogenesis of Kienböck disease. [Orthopedics. 2021;44(2):e243-e247.].

Effect of gadolinium perfusion magnetic resonance imaging on surgeons' management preferences in kienböck's disease. A survey study

In literature, the use of gadolinium perfusion magnetic resonance imaging (GP-MRI) is recommended in Kienböck's disease to evaluate the lunate bone's perfusion. This survey study sought to assess how GP-MRI findings affect the management preferences of hand surgeons. A questionnaire consisting of 11 scenarios differing in ulnar variance, GP-MRI findings and management preferences was developed. The scenarios were designed based on the last published clinical guidelines. The questionnaire was sent to the members of a national hand surgery society consisting of 160 hand surgeons. Sixty-six surgeons completed the questionnaire. The surgeons' preferences changed significantly by ulnar variance in stages II and IIIA, and by GP-MRI in stages I and II. No need for other diagnostic tools was found in any of the scenarios. Management preferences of the study participants related to alterations in ulnar variance and treatment choices in all stages were in accordance with previously published clinical and survey studies. This study showed that GP-MRI findings significantly changed the management preferences of hand surgeons in early stages of Kienböck's disease. There was no significant tendency among the participants to use further assessment tools beyond direct radiography, MRI, and GP-MRI. Given the study results and the literature, we emphasize the limited and well-defined indications of GP-MRI in Kienböck's disease.

Arthroscopic "S"-shaped Ligamentoplasty for Floating Lunate

The concurrence of tears of the scapholunate (SL) and lunotriquetral (LT) ligaments is not unusual and can also occur without an apparent perilunate dislocation. Badia and Khanchandani called this combined lesion a "floating lunate" because the ligamentous attachments on both sides of the lunate are absent and the lunate floats in a neutral position. There have been few published papers referring to the treatment of this kind of instability. In recent years, we have developed an arthroscopic ligamentoplasty for SL instability. However, this procedure is not indicated whether the LT ligament is also damaged. With this current modification, both the strongest portions of the SL and LT ligaments can be reconstructed without opening the joint, thereby avoiding an open approach. We have described this as an "S"-shaped ligamentoplasty, as the graft resembles an "S" as it travels inside the scaphoid, lunate, and triquetrum. The same postoperative early mobilization protocol can be applied to this kind of reconstruction.

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.

Kienböck's disease: Where do we stand?

Avascular necrosis of the lunate, commonly known as Kienböck's disease is a disorder that can lead to carpal collapse and the need for surgeries, which can stabilize the wrist. There are different associations with the disease but the exact etiology is unknown. Kienböck's disease is believed to result from mechanical and vascular factors in genetically predisposed individuals. The newer classification based on advanced wrist arthroscopy and MRI help in a better understanding of the disease, early diagnosis, and treatment. A review of recent literature regarding newer treatment options has shown good results in the early stages of osteonecrosis. This article intends to review an update on the etiopathogenesis, classification, and the current advanced treatment options.

Evaluation for Kienböck Disease Familial Clustering: A Population-Based Cohort Study

PURPOSE

Kienböck disease (KD) is rare and its etiology remains unknown. As a result, the ideal treatment is also in question. Our primary purpose was to test the hypothesis that KD would demonstrate familial clustering in a large statewide population with comprehensive genealogical records, possibly suggesting a genetic etiologic contribution. Our secondary purpose was to evaluate for associations between KD and known risk factors for avascular necrosis.

METHODS

Patients diagnosed with KD were identified by searching medical records from a comprehensive statewide database, the Utah Population Database. This database contains pedigrees dating back to the early 1800s, which are linked to 31 million medical records for 11 million patients from 1996 to the present. Affected individuals were then mapped to pedigrees to identify high-risk families with an increased incidence of KD relative to control pedigrees. The magnitude of familial risk of KD in related individuals was calculated using Cox regression models. Association of risk factors related to KD was analyzed using conditional logistic regression.

RESULTS

We identified 394 affected individuals linked to 194 unrelated high-risk pedigrees with increased incidence of KD. The relative risk of developing KD was significantly elevated in first-degree relatives. There was a significant correlation between alcohol, glucocorticoid, and tobacco use and a history of diabetes, and the diagnosis of KD.

CONCLUSIONS

Familial clustering of KD observed in the Utah Population Database cohort indicates a potential genetic contribution to the etiology of the disease. Identification of causal gene variants in these high-risk families may provide insight into the genes and pathways that contribute to the onset and progression of KD.

CLINICAL RELEVANCE

This study suggests that there is a potential genetic contribution to the etiology of KD and that the disease has a significant association with several risk factors.

Avascular Necrosis of the Lunate Following Reconstruction of the Scapholunate Ligament Using the Scapholunate Axis Method (SLAM)

Various surgical treatment options have been described to address chronic scapholunate dissociation. The Scapholunate Axis Method (SLAM) is a new technique used to reconstruct the scapholunate interosseous ligament. It is biomechanically advantageous compared with other ligament reconstruction techniques but clinical studies are lacking. We describe a previously unreported complication of avascular necrosis of the lunate after the SLAM procedure.

Superselective angiography of the wrist in patients with Kienböck's disease

BACKGROUND

Microvascular problems like increased intraosseous pressure or venous congestion may influence the development of Kienböck's disease. We examined if wrist position modifies the blood flow in the nutrient vessels.

METHODS

Retrospective analysis of 17 patients with Kienböck's disease who had a superselective microangiography of the radial, ulnar and interosseous artery in different wrist positions under general anaesthesia. We analysed the data with Fisher's exact and Wilcoxon-test.

RESULTS

We found vessels that entered the bone, that ended at the bone edge, and that supplied a vascular plexus. The origins were the anterior interosseous artery in 10 of 17 cases, the radial artery in seven cases, and the ulnar artery in five cases. Movement of the wrist could reduce or stop the blood flow. Type of lunate configuration showed no significant influence on the blood supply in neutral position.

CONCLUSION

The radial, ulnar, and anterior interosseous artery contribute to the vascular supply of the lunate bone in different combinations. Wrist movement can reduce blood flow to the lunate bone.

The Effect of Lunate Morphology in Carpal Disorders: Review of the Literature

Variation in lunate morphology can exist based on the absence (Type I) or presence (Type II) of medial facet on the distal articular surface of the lunate that contacts the proximal pole of the hamate. This additional lunatohamate articulation can affect load transmission across the radiocarpal joint and exert an influence on carpal kinematics. A Type II lunate is protective against carpal instability patterns associated with scaphoid nonunions and scapholunate dissociations. It may also play a role in the progression of carpal collapse that occurs in Kienböck disease. This review summarizes the effect of lunate morphology in the outcomes of non-operative and operative treatment of carpal disorders.

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.

Arthroscopic Scapholunate Ligament Reconstruction, Volar and Dorsal Reconstruction

Arthroscopic scapholunate volar and dorsal ligament reconstruction achieves an anatomic reconstruction, avoids an open approach and capsular detachment, and provides a strong construct for early mobilization. Clinical results are discussed. Detailed "surgical tips" and technical modifications are provided.

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.

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.

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.

The effect of lunate morphology in Kienböck disease

PURPOSE

To determine if the absence (type I lunate) or presence (type II lunate) of a medial hamate facet on the lunate affects the radiographic characteristics of patients presenting with Kienböck disease.

METHODS

A retrospective review was performed on all patients evaluated at our institution from 2002 to 2010 with a diagnosis of Kienböck disease confirmed on plain radiographs in concert with magnetic resonance imaging (MRI) and/or bone scan. Study groups consisted of patients with type I versus type II lunates, as determined by radiographs, MRI, and/or computed tomography. Measured variables included the modified Lichtman stage on presentation, radioscaphoid angle, presence or absence of a coronal plane fracture of the lunate, modified carpal height, ulnar variance, and ulnar translocation of the carpus at the time of presentation.

RESULTS

A total of 106 wrists were examined, of which 75 were type I (71%) and 31 were type II (29%) lunates. At the time of presentation, there was significantly more advanced disease (stage IIIA or greater) in patients with type I (N = 64, 86%) compared with those with type II lunates (N = 19, 61%). Coronal fractures of the lunate were more prevalent in patients with type I (N = 58, 75%) compared with type II lunates (N = 18, 58%). In the absence of a coronal fracture, radioscaphoid angles were greater in patients with a type I (53°) versus a type II lunate (45°).

CONCLUSIONS

Lunate morphology may affect the severity of Kienböck disease at the time of initial presentation. Type II lunates appear to be protective against coronal fractures and scaphoid flexion deformities. This study provides further evidence that lunate morphology affects carpal pathology and may have implications for treatment options in Kienböck disease.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.

Arthroscopic ligamentoplasty of the dorsal and volar portions of the scapholunate ligament

Classical arthroscopic techniques for scapholunate instability consist of debridement, thermal shrinkage, and percutaneous pinning. Good results are obtained in acute lesions or in chronic partial tears, but they are less predictable when the lesion is complete, because of the poor healing capacity of the scapholunate ligament and because it is not possible to perform an anatomic ligamentous reconstruction with these techniques. Open techniques are thus required for reconstruction, but they damage the soft tissues. We recently published a description and cadaver study of an arthroscopic ligamentoplasty, trying to combine the advantages of arthroscopic techniques (minimally invasive surgery) and open techniques (reconstruction of the ligament). With this approach, it is possible to reconstruct the dorsal scapholunate ligament and the secondary stabilizers while causing minimal damage to the soft tissues and avoiding injury to the posterior interosseous nerve and detachment of the dorsal intercarpal ligament. The current report describes an additional step to this technique with which it is possible to reconstruct the volar portion of the scapholunate ligament. We also describe an early mobilization postoperative protocol that we believe is equally important.

Treatments for acute and old distal radius fracture with lunate dislocation

PURPOSE

Our study was undertaken to determine the correct treatment protocol for distal radius fracture with lunate anterior dislocation.

METHODS

From 2000 to 2007, 58 patients (36 with acute injury and 22 with old injury) with distal radius fracture with lunate anterior dislocation were enrolled in the study. Among acute injury patients, 15 were treated through manipulative reduction and plaster fixation and 21 were treated through minimal invasive poking reduction followed by Kirschner wire and plaster fixation. Among old injury patients, 8 underwent operative reduction of lunate dislocation through the palmar approach and Kirschner wire and plaster fixation, whereas 14 patients underwent operative reduction and fixation through the dorsal approach combined with reparation of the dorsal radiolunate ligament. Lidstrom wrist function scores and the morbidity of lunate necrosis and osteoarthritis were documented and evaluated.

RESULTS

Lidstrom wrist function scores revealed that the rate of excellent and good scores was higher in acute injury patients than in old injury patients (91.7 versus 54.5%, respectively; P = 0.018). The lunate necrosis rate was lower in acute injury patients than in old injury patients (0 versus 27.2%, respectively; P = 0.027). For old injury patients, the lunate necrosis rate was higher in those treated with the palmar approach than in those treated with the dorsal approach (50 versus 14.3%, respectively; P = 0.033).

CONCLUSIONS

The key points for resolving distal radius fracture with lunate dislocation are prompt and precise diagnosis and treatment of lunate dislocation to prevent old lunate dislocation. We recommend that the surgical procedure is performed through the dorsal approach with reparation of the dorsal radiolunate ligament.

Kienböck disease

Kienböck disease, or osteonecrosis of the lunate, is a progressive disease process that can lead to wrist pain and dysfunction. Although it was described over 100 years ago, and advances have been made in understanding this disease, the precise etiology remains uncertain. Anatomic, mechanical, vascular, and traumatic factors have been suggested to contribute to the disease. The natural history is unknown, and radiographic and clinical findings do not always correlate. Progress has been made in recognizing the progression of the avascular process and its deleterious effects on wrist mechanics. Initial treatment is nonsurgical, and it remains unclear whether surgical intervention results in improved outcomes over nonoperative treatment. Traditional surgical procedures such as radial shortening osteotomy and proximal row carpectomy have been shown to be reliable treatment options for relieving pain and improving function. Newer procedures such as pedicled bone grafts from the distal radius may improve direct revascularization of the lunate in earlier stages of the disease, potentially arresting the progression of collapse. Additional data are necessary to determine with certainty whether this type of procedure represents an improvement over the traditional treatment alternatives. Kienböck disease remains a challenging problem for hand surgeons.

STUDY OF VASCULAR SUPPLY OF LUNATE AND CONSIDERATION APPLIED TO KIENBÖCK DISEASE

The purpose of this study was to assess vascularity of the lunate by number of foramina and radiography of vessels of the wrist. The genesis of lunatomalacia requires some vascular risk and mechanical predisposition. The findings were correlated with the cause of Kienböck's disease. The vascular foramina were more than two in 91.33% of the lunate. The lunate had consistent dorsal and palmar branches from radial artery. The additional branches from anterior interosseous artery in 72.22% and a branch of palmar inter carpal arch in 69.44% cases contributed in arterial anastomosis on palmar aspect of lunate. The dorsal blood supply was found by anterior interosseous artery in 85.71% of specimens and dorsal branch from dorsal intercarpal arch in 50% of specimens. The blood supply of lunate comes along with various ligaments which may be disrupted due to trauma or strain leading to avascular necrosis. The present observations are suggestive of rich blood supply of lunate in comparison of other investigations. Therefore Kienböck's disease is less common in northern India.

Arthroscopic findings of Kienböck's disease

PURPOSE

Kienböck's disease affects the lunate bone, and osteoarthritic changes progress as the disease advances; however, relatively few studies have reported the arthroscopic findings of Kienböck's disease, and these reports have been in small populations. The purpose of this study was to review arthroscopic findings in a larger population than studied in previous reports.

METHODS

We retrospectively reviewed 57 patients who underwent radial osteotomy for Kienböck's disease after arthroscopy of both the radiocarpal and midcarpal joints. All arthroscopic findings were classified as follows in terms of the location of osteoarthritic changes: lunate fossa of the radius, proximal/distal surface of the lunate bone, and capitate head. Radiological stages were classified according to the modified Lichtman's classification system.

RESULTS

All but two patients had cartilage lesions in the proximal lunate cartilage. Older patients had significantly more cartilage lesions, but radiological stage showed no correlation with the number of cartilage lesions.

CONCLUSIONS

This study demonstrated that the proximal lunate bone was affected in most cases of Kienböck's disease and that older patients had more cartilage lesions.

Arthroscopic ligamentoplasty (bone-tendon-tenodesis). A new surgical technique for scapholunate instability: preliminary cadaver study

We present an anatomical study and description of a new surgical technique for arthroscopic treatment of scapholunate ligament injuries. Five cadaver specimens were used to perform the technique. After arthroscopic surgery, anatomic dissection was performed to measure the distances to critical wrist structures such as the posterior interosseous nerve and the radial artery, and the size and position of the plasty. This arthroscopic technique offers three advantages: soft tissue damage is reduced (avoiding an extensive approach and injury to the secondary stabilizers and reducing scar tissue); injury to the posterior interosseous nerve is avoided (maintaining wrist proprioception and the role of the dynamic stabilizers); and a biotenodesis is made that ensures proper placement, tension and functionality of the flexor carpi radialis ligament reconstruction.