Keywords
Kienböck's disease - lunate avascular necrosis - wrist arthroscopy - scaphocapitate
arthrodesis - partial wrist fusion.
Introduction
Kienböck's disease, described in 1910 by radiologist Robert Kienböck as a lunate chondromalacia,[1]
[2]
[3] represents a real challenge for hand surgeons since the current literature remains
unclear regarding its etiology, natural evolution, and specific treatment.[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
This is a progressive clinical-radiological condition of the wrist involving the lunate
bone, which can fragment and collapse due to avascular necrosis.[2] It mostly affects young, working people,[4] usually at the dominant extremity. Bilateral involvement is rare.[9]
Although Kienböck's disease etiology and pathogenesis remains unknown,[1]
[2]
[4]
[5] several potential causes have been postulated, including repetitive trauma, vascular
changes and lunate anatomical (extravascular) differences as the most studied entities.[1]
[2]
[4]
[5]
Patients often present hand complaints evolving for months[10] which are usually confused with other conditions. Fifty per cent of these patients
have a history of minor trauma.[9] The clinical presentation is characterized by dorsal wrist pain,[2]
[3]
[4]
[5] commonly progressive, and potentially associated to limited hand extension and loss
of hand strength.[5]
A patient with these features requires a correct diagnosis to base a therapeutic proposal
tailored to individual needs. Initial imaging study with simple radiographs (anteroposterior
[AP] and profile [P] images) of the wrist may be sufficient to establish the diagnosis
in patients with advanced Kienböck's disease, but it is of little use in its first
stages, in which wrist synovitis predominates. In these cases, magnetic resonance
imaging (MRI) is critical for diagnosis and differential diagnosis; in addition, MRI
provides fundamental information for therapeutic decisions, especially in assessing
lunate vascular conditions[3] and adjoining structures, like joint cartilage.
Radiologically, characteristic images of the disease have been described both for
the lunate and remaining carpal bones. In 1977, Lichtman et al.[11] described a classification system that has been used in the literature for the last
50 years. This system is centered on simple wrist radiographies detailing the progressive
stages of the disease, which are based mainly on lunate deformities and involvement
of other carpal bones. In 2006, Bain and Begg[12] proposed an arthroscopic classification for Kienböck's disease based on the status
of the midcarpal and radiocarpal joints cartilage. In recent years, these authors
have proposed a new classification method incorporating clinical features and previous
systems in an updated treatment algorithm.[3]
The arthroscopic assessment allows for a better evaluation of the true status of the
lunate and carpal bones joint cartilage regarding the pathophysiological progression
of the intraosseous damage associated with cartilage injury. Arthroscopy can provide
accurate information to base the proper initial or definitive surgical treatment.[8] In addition, it has a fundamental role at the therapeutic decision-making process.
Based on Lichtman and Bain[3]
[7] and considering mainly the lunate bone status and the secondary wrist joint involvement,
a therapeutic scheme can be proposed. Early Kienböck's disease treatment usually aims
a favorable environment for lunate revascularization; in advanced disease, however,
treatment aims to diminish the pain caused by synovitis and to preserve movement.
This paper discusses the arthroscopic technique used for wrist joints diagnosis and
assessment. We also suggest a therapeutic scheme according to the stage of the condition
and describe the arthroscopic techniques most often used in patients with Kienböck's
disease.
Arthroscopic Evaluation of the Wrist with Kienböck's Disease
Arthroscopic Evaluation of the Wrist with Kienböck's Disease
We believe that a comprehensive initial arthroscopic evaluation of the wrist is required
to accurately diagnose its joint status and to indicate the proper treatment for these
patients. This is especially true in more advanced stages since the surgical technique
depends on these findings. We frequently indicate surgery based on the clinical and
imaging evaluation with no previous arthroscopy. In these interventional cases, and
considering our preferences for surgical treatment, the procedure begins with a diagnostic
arthroscopy for joint evaluation and the appropriate operative technique is contingent
on the findings in each case. To do so, we often have a therapeutic scheme focused
on lunate involvement and the general status of the wrist based on the Litchman classification.[12] For the surgical act, we usually try to have all the supplies and instruments required
for different techniques; although there are no substantial differences in such resources,
the surgeon must have the training, experience and versatility in a wide range of
proposed techniques after joint surfaces assessment, which is a critical point for
making decisions about the selected approach.
Our assessment starts with a standardized diagnostic wrist arthroscopy technique for
radiocarpal evaluation using the classic 1-2, 3-4 and 6R portals and then the midcarpal
joint evaluation using the midcarpal ulnar (MCU) and midcarpal radial (MCR) portals.
The main concern at this stage is joint cartilage status assessment. Through the radiocarpal
joint, the quality of the distal radial joint surface in its two pits and the proximal
joint facets of the scaphoid and lunate bones are evaluated. In addition, the intrinsic
scapholunate and lunotriquetral ligament structures, the extrinsic ligaments, and
the triangular fibrocartilage complex are examined. It is important to record specifics
about any lunate cartilage softening (mainly in its most proximal, radial region),
wear with subchondral bone involvement, and lunate fragmentation or overt fracture,
with coronal fractures with the worst prognosis.[13] At the midcarpal joint, emphasis is placed on capitate and scaphoid evaluation for
signs of osteoarthritis; the lunate must be assessed for the same phenomena described
for the radiocarpal joint.
In both joints, it is also very important to evaluate the ligament status in a targeted
manner, looking for any associated instability that could compromise surgical outcomes.
Following a complete evaluation of the midcarpal joint, the patient is classified
according to the Bain and Begg system.[11] This will allow us to indicate the proper surgical technique to be performed.
Therapeutic Decision-Making
Therapeutic Decision-Making
The therapeutic decision making in a patient with Kienböck's disease is complex and
must consider a number of individual factors, including age, functionality, dominance,
work and recreational activities, and concomitant conditions. Patients are usually
young, athletic, workers with important functional requirements.
This is why, when surgery is indicated, we try to perform minimally invasive procedures
that spare healthy structures and mobility as much as possible. The therapeutic goal
is to prevent lunate and carpal bones collapse in the initial stages, to restore the
architecture in advanced stages and to improve function and pain in terminal stages
of the disease.
Therapeutic options include multiple surgical techniques specifically aimed at the
Kienböck's disease stage at the time of the surgical decision, either with early minor
lunate fragmentation and collapse or more advanced degrees of lunate devascularization
and radial and midcarpal joints involvement.
Treatment is aimed at reducing pain, protecting the vulnerable lunate bone, and providing
an ideal environment for revascularization.[3] In more advanced stages, with significant lunate involvement and secondary joint
involvement, the treatment is aimed at reducing pain and trying to preserve some degree
of wrist mobility through techniques such as partial carpal arthrodesis or proximal
carpectomy.[3]
[7] In terminal stages, with advanced wrist involvement, definitive treatment consists
of salvage techniques, such as total wrist arthrodesis or arthroplasty.[3]
On the other hand, it is important to recognize our own technical limitations and
remember that these procedures are complex and require a learning curve to avoid complications
and poor clinical outcomes due to surgical failure.
Management in Early Stages
Management in Early Stages
Early stages refer to those with a structurally undamaged lunate and no cartilage
changes at both the midcarpal and radiocarpal joints. These patients are classified
as stages 0, I and II according to Litchman[12] and stage 0 according to Bain and Begg.[11]
The initial treatment for early stages of the disease consists of no less than 6 weeks
of immobilization and symptomatic pain management followed by a period of rehabilitation.[14] The goal is to stop lunate necrosis evolution and to detect revascularization signs
at an MRI scan ([Figure 1]).
Figure 1 Clinical case of a 32-year-old female patient with dominant limb diagnosed with Kienböck's
disease in stage 0 to I per Lichtman and 0 per Bain/Begg. She was treated with a short
arm cast for 3 months. The previous and final magnetic resonance imaging scans are
shown, revealing lunate vascular changes.
Surgical treatment is indicated to patients with no symptomatic or imaging improvement
even after a prolonged period of immobilization. In such cases, surgery aims to reduce
the load and stress over the lunate bone, with different surgical techniques for mechanical
or biological lunate decompression.
Surgical options for mechanical decompression include distal radius wedge osteotomy
and capitate shortening osteotomy, both with good long-term clinical outcomes.[15] We do not perform these routine techniques in these patients, and we prefer biological
decompression procedures.
There are two techniques for lunate biological decompression: the forage-type lunate
decompression and the metaphyseal decompression of the distal radius described by
Illarramendi et al.,[16] who reported good long-term outcomes.[17] We routinely perform this latter technique, either alone or associated with a vascularized
graft in Lichtman stage II. Through a bone window in the lateral border of the distal
radius, the metaphyseal cancellous bone is compressed with a spoon towards the distal
radial walls. This would produce an increase in the revascularization potential of
the lunate due to the local activation of reparative factors resulting in focused
hyperemia and neovascularization stimulation. It is a simple, reproducible procedure
that does not alter the normal anatomy of the wrist.
As previously mentioned, in patients with Lichtman stage II, we suggest the distal
radial vascularized graft technique along with the decompression procedure.[18] We use a dorsal graft under the 4-5 extensor compartment and protect it with a short
arm cast and a scaphocapitate Kirschner wire for 6 weeks ([Figure 2]). Our series of seven patients followed-up for 3 years yielded good outcomes, with
100% revascularization, immediate pain reduction, mobility range improvement and activities
resuming.
Figure 2 Surgical technique to obtain a vascularized graft from the 4-5 extensor compartment.
The graft and its pedicle, the perforation in the recipient lunate and the surgical
outcome are shown. The postoperative anteroposterior radiograph of the wrist shows
the scaphocapitate guidewire protected with a Kirschner wire and a short arm cast
for 6 weeks.
In summary, patients in stages 0, I and II are conservatively treated for 2 to 3 months.
In case of medical treatment failure, we suggest a metaphyseal decompression technique
for patients in stages 0 and I and its association with a vascularized graft for patients
in stage II.
Management in Intermediate Stages
Management in Intermediate Stages
Intermediate disease consists in Lichtman stage IIIA, with complete lunate involvement
but sparing the remaining carpal bones and with no wrist collapse.
In these patients, arthroscopy is essential to assess the lunate joint cartilage status
and indicate the proper surgical treatment. In patients classified as Bain and Begg
stage 1, we indicate a proximal carpectomy. This is an infrequent scenario and we
usually find some distal radial joint damage which contraindicates this technique.
For these patients, who correspond to Bain and Begg stage 2a, we propose a scaphocapitate
arthrodesis as the technique of choice.
Scaphocapitate arthrodesis was initially described as an open technique[7]
[19] for scaphoid nonunion management. It transfers the load to the radial column, decompressing
the damaged central column. It can be performed when the lunocapitate joint facet
is compromised, a stage in which proximal carpectomy is contraindicated and with few
therapeutic options.
In recent years, arthroscopic partial carpal arthrodesis techniques have been developed[2]
[3]
[5]
[6]
[7]
[8] with the advantages of being minimally invasive and less associated with soft tissue
damage.[8] Scaphocapitate arthrodesis may be performed with arthroscopic assistance and its
associated advantages. The arthroscopic technique is described under “Surgical Technique
for Scaphocapitate Arthrodesis with Arthroscopic Assistance”.
Management in Advanced Stages
Management in Advanced Stages
Patients with Lichtman stages IIIA, IIIB and IIIC and joint involvement 2-4 per the
Bain and Begg classification are considered advanced cases. In these patients, since
both the radiocarpal and midcarpal joints are affected, therapeutic options are limited,
and partial fusions are considered the treatment of choice.
We suggest the technique of scaphocapitate arthrodesis with arthroscopic assistance
for these patients. We believe that this is an effective technique to reduce painful
symptoms while allowing for some range of mobility of the wrist.
Surgical Technique for Scaphocapitate Arthrodesis with Arthroscopic Assistance
Wrist positioning and traction are performed according to the standard arthroscopy
technique. A 2.7-mm optics with 30° angulation is required. Diagnostic arthroscopy
must be wet and performed with no ischemia because surgical arthrodesis can be demanding
and must not exceed 120 minutes. Epinephrine in a 1:1000 dilution is injected directly
at the portals, with no intra-articular drug injection. After diagnostic arthroscopy,
limb ischemia is performed using a proximal tourniquet at 100 mm Hg above the patient's
systolic pressure. At this phase, we suggest a mixed approach, using wet arthroscopy
with free fluid rinse (connected to two bags of Ringer Lactate solution, 6 L each),
and dry arthroscopy according to the surgical step.
-
Diagnostic radiocarpal arthroscopy: A diagnostic arthroscopy is performed as previously described. In these patients,
we expect to find a fragmented lunate with damaged joint cartilage ([Figure 3A]). The scaphoid is expected to be intact, as well as the scaphoid facet of the distal
radius. The scapholunate ligament, which is usually injured, must be visualized. It
is important to visualize the radioscaphocapitate (RSC) ligament, which must be intact
for this technique. We suggest a wet arthroscopy for this stage to better visualize
all the structures requiring evaluation.
-
Diagnostic midcarpal arthroscopy: Midcarpal portals are used to visualize the midcarpal joint cartilage. In this stage,
the lunate is usually fragmented and there is evident damage to the joint cartilage
([Figure 3B]). The proximal pole of the capitate presents obvious signs of chondromalacia ([Figure 3C]) and a complete scapholunate lesion is often present. This step is performed under
wet arthroscopy.
-
Arthroscopic fragmentation of the lunate and partial lunectomy: Using a 2.9-mm burr and a 2.9-mm shaver, the lunate is fragmented and partially resected.
This is done through both joints using the midcarpal and radiocarpal portals. The
lunate is partially removed since this approach does not allow for a complete resection.
With the shaver, the scapholunate and lunotriquetral ligaments are also resected,
leaving a space in the place of the lunate. It is important to perform the lunectomy
using a mixed arthroscopy, interspersing dry and wet phases for proper joint cleaning
and to reduce the heat generated by the instruments.
-
Scaphoid and capitate cartilage denudation: An accessory radial midcarpal portal (MCR-A) is made over the scaphoid and used as
a “working portal”. With the optics at the MCU, we work through the MCR and MCR-A
portals and the scaphocapitate joint cartilage is completely denuded using the burr
and shaver. At this stage, it is important to have an adequate flow of intra-articular
solution for cleaning and dissipating the heat generated. Since there is a space in
the first carpal row due to the previous excision of the lunate, it is possible to
pass the optics through the radiocarpal portals for visualization and to use the midcarpal
portals as working portals.
-
Complete lunate resection through the 3-4 portal: Traction is released, and the limb is horizontally positioned on the table with the
hand in pronation. The 3-4 portal is enlarged through a mini-open approach of sufficient
size to pass a gouge-type forceps ([Figures 4] and [5]). Through it, the previously fractionated lunate is completely resected, and, under
fluoroscopy, we ensure complete bone excision and the absence of intra-articular free
bone fragments.
-
Bone graft extraction and Illarramendi technique: A 3-cm approach is made on the lateral aspect of the distal radius by blunt dissection
between the first and second extensor compartments. Bone can be accessed protecting
structures at risk. A cortical window is carved into the distal radial metaphysis
and a cancellous graft is extracted with a spoon. Next, a metaphyseal decompression
of the distal radius is performed as described by Illarramendi et al[12] ([Figure 6]).
-
Stabilization with guidewires: Under fluoroscopic view, two scaphocapitate guidewires were implanted in a parallel
arrangement in the same position headless compression screws were subsequently fixed
for future arthrodesis. Screw guidewires are used; we used a 3.0-mm distal screw and
a 2.4-mm proximal screw. After placing both guidewires in the correct position, they
are completely withdrawn from the capitate, leaving them only at the scaphoid thickness.
-
Arthroscopic assistance for bone graft provision: The limb is repositioned for traction and an arthroscopy of the midcarpal joint is
repeated. Through the MCR and MCR-A, the previously loaded morselized graft is introduced
into an arthroscopic sleeve similar to the one used at the previously denuded scaphocapitate
space ([Figures 7] and [8]).
-
Scaphocapitate screws fixation: The traction device is removed, and the limb is horizontally positioned with the
wrist in pronation. Using the fluoroscope, the passage of the scaphocapitate guidewires
is completed and both arthrodesis screws are implanted. As previously mentioned, we
use a 3.0-mm distal and a 2.4-mm proximal headless screws. The correct positioning
of screws and the graft is checked under fluoroscopy ([Figure 9]).
Figure 3 Diagnostic arthroscopic images during scaphocapitate arthrodesis. A) Visualization
of the lunate fragmentation from the radiocarpal joint. The arrow shows a cartilage
flap at the proximal lunate. B) Lunate joint cartilage damage visualized through the
midcarpal joint. C) Capitate joint cartilage damage seen through the midcarpal joint.
S = Lunate, C = Capitate, T = Triquetrum.
Figure 4 Scheme for lunate complete resection through a mini-open approach at the 3-4 portal.
Figure 5 Mini-open approach for lunate extraction.
Figure 6 Intraoperative radiographic image of the distal radius graft and Illarramendi technique.
Figure 7 Scheme for scaphocapitate arthrodesis with two cannulated headless screws and a morselized
graft.
Figure 8 Arthroscopic image from the introduction of a morselized graft into the scaphocapitate
space.
Figure 9 Fluoroscopic view of the scaphocapitate arthrodesis with screws.
Postoperative Rehabilitation
A removable wrist immobilizer is used for 2 weeks (until suture removal) and then
a molded short arm cast is placed for 4 weeks. At 6 weeks, initial consolidation is
assessed in a CT scan. If bone bridges are detected, the patient is referred to kinesiotherapy.
Rehabilitation is performed until accepted functional ranges are recovered and there
is no pain.
This technique has yielded good clinical-imaging outcomes in a series of six operated
patients. All presented with complete consolidation, significant pain improvement
and joint ranges preservation ([Figure 10]).
Figure 10 Follow-up of a patient submitted to a scaphocapitate arthrodesis with arthroscopic
assistance 6 months ago. Joint ranges and the pre- and postoperative radiographs are
shown.
We believe that scaphocapitate arthrodesis is an effective technique in reducing pain
symptoms and allowing limb function in these patients. In contrast to the open technique,
arthroscopic assistance has the advantage of being a minimally invasive procedure,
reducing associated soft tissues damage, improving postoperative rehabilitation, and
providing better cosmetic results.[8]
Management in Terminal Stages
Management in Terminal Stages
Patients with complete lunate involvement and carpal collapse (Lichtman stage IV)
are considered terminal cases. For them, surgical management consists of salvage surgeries.
We propose arthrodesis or total wrist arthroplasty as the proper surgical options
for these patients. The objective in these cases is clearly to reduce pain and regain
limb function.
Conclusion
Kienböck's disease represents a challenge for hand surgeons because it is a complex
condition that generates wrist pain and loss of function in young, mainly working
people who require timely treatment to achieve the best clinical outcomes.[2]
[4]
[5] Advanced stages, with generalized carpal osteoarthritis, are often managed with
salvage surgeries such as wrist arthroplasty or total wrist arthrodesis.[4]
[7]
[11] For earlier stages, there is no consensus on the best treatment and the literature
describes different surgical techniques to reduce the pain caused by synovitis and
destruction while trying to preserve as much function as possible.[7]
[11]
In this context, partial carpal arthrodesis seems to be a proper option with good
outcomes reported in the literature.[2]
[3]
[4]
[5]
[6]
[7]
[8]
[11] Scaphocapitate arthrodesis reduces the load on the middle column by transferring
it to the radial column, thereby reducing pain while preserving some degree of wrist
mobility.[7]
Ho et al.[8] describe different types of arthroscopic partial carpal fusions with good clinical
outcomes and suggest this method as optimal for patients with limited carpal osteoarthritis
who wish to preserve function. Although it is a demanding technique, it has a low
rate of complications and high rates of union, with consolidation times comparable
to those obtained with open techniques.
We propose a therapeutic scheme according to the Lichtman and Bain/Begg classification
systems ([Figure 11]).
Figure 11 Surgical treatment scheme proposed by the authors according to lunate and wrist involvement.
* SC = Scaphocapitate.
