Guidelines Development Process
Guideline Development Principles
The Guidelines were developed in accordance with the “World Health Organization Handbook
for Guideline Development”[4 ] and the “Appraisal of Guidelines for Guidelines for Research and Evaluation.”[5 ] The guideline report refers to the “Reporting Items for Practice Guidelines in Healthcare.”[6 ]
Guideline Working Group
The guideline working group comprised clinical experts in hand surgery, microsurgery,
orthopaedics, and methodological experts, along with public representatives.
The group, led by two cochairs (one clinical and one methodological), established
five subcommittees: steering group, secretariat, evidence evaluation team, consensus
team, and external review team.
Steering Group
The steering group comprised clinical and methodological professors responsible for
forming subcommittees, managing conflicts of interest, defining the guideline scope,
proposing, and finalizing key questions based on voting, summarizing recommendations
from evidence evaluation, overseeing the guideline development process, and approving
the final guideline.
Secretariat
Secretariat comprised clinical experts responsible for coordinating intersubcommittee
work, drafting the guideline plan, researching clinical issues, organizing consensus
meetings, recording the guideline development process, and submitting the guideline
for publication.
Evidence Evaluation Group
The evidence evaluation group comprised experts in evidence-based medicine, responsible
for structuring clinical questions using the population, intervention, control, and
outcomes principle, searching, evaluating, and grading evidence, and creating evidence
summaries and recommendation tables.
Consensus Group
The consensus group comprised multidisciplinary experts, including clinical experts
in hand surgery, microsurgery, orthopaedics, and methodological experts, representing
diverse countries including Australia, China, India, Japan, Korea, Singapore, and
other Asia-Pacific countries; they voted on key questions and recommendations.
External Review Group
The external review group comprised clinical professors, methodological professors,
and patients with UIS. Their responsibilities included peer-reviewing the final draft
of the Guidelines and providing input on significant risks or issues within the Guideline
scope and recommendations.
Considering the end-users, two patients were included in the Guideline development,
and their input was sought during the external review phase of the final draft.
Evidence Retrieval
The literature search for the Guideline development involved comprehensive searches
across databases such as PubMed, Ovid, Web of Science, Embase, and CNKI. Various types
of articles, including clinical trials, meta-analyses, randomized controlled trials,
reviews, and systematic reviews were considered.
Key search terms included “ulnar impaction syndrome, ” “ulnar positive variance, ”
“ulnar wrist pain,” “triangular fibrocartilage complex,” “conservative treatment,”
“surgical treatment,” “ulnar shortening osteotomy,” “cut,” “transverse,” “oblique,”
“freehand,” “osteotomy guide,” “jig,” “locking plate,” “nonlocking plate,” and “biomechanical,”
“wafer procedure,” “wrist arthroscopy,” “distal metaphyseal ulnar shortening osteotomy,”
“distal radioulnar joint arthritis,” “Sauvé–Kapandji,” “Darrach,” “postoperative,”
“wrist joint fixation,” “rehabilitation,” and others.
During the literature retrieval process, articles with content repetition, inconsistent
information, and inaccessible full text were excluded to ensure the quality and relevance
of the selected literature for online development.
Formation of Key Questions and Recommendations
Formation of Key Questions
A modified Delphi survey method was employed to generate key questions proposed by
the steering group and conducted in two rounds. In the first round, questions with
a support rate of ≥75% were directly accepted. Questions with a support rate of <75%
but ≥50% were modified based on feedback and subjected to a second round of voting.
Questions with a support rate of <50% in the first round were eliminated. In the second
round, only questions with a support rate of ≥75% were included as key questions.
Formation of Recommendations
Similarly, a modified Delphi survey method was used for two rounds to evaluate the
recommendations summarized by the steering group and evidence evaluation team. In
the first round, recommendations with a support rate of ≥75% were directly accepted.
Recommendations with a support rate of <75% but ≥50% underwent modification based
on feedback and a second round of voting. Recommendations with a support rate of <50%
in the first round were eliminated. In the second round, only recommendations with
a support rate of ≥75% were included as key recommendations.
Evidence Level and Recommendations
Clinical evidence was assessed using the Oxford Centre for Evidence-Based Medicine:
Levels of Evidence (March 2009).[7 ] The evidence was categorized into five levels: 1, 2, 3, 4, and 5. Systematic reviews
of randomized controlled trials (RCTs) were assigned the highest level of evidence,
denoted as “Level 1.” Expert opinion without an explicit critical appraisal, or based
on physiology, bench research, or “first principles,” was denoted as “Level 5.” Different
levels of evidence corresponded to different grades of recommendation, as shown in
[Table 1 ].
Table 1
Oxford Centre for Evidence-Based Medicine: levels of evidence (March 2009)
Grades of recommendation
Level of evidence
Content
A
1a
A systematic review (with homogeneity) of RCTs
1b
Individual RCT (with narrow confidence interval)
1c
All of none (met when all patients died before the Rx became available, but some now
survive on it; or when some patients died before the Rx became available, but none
now die on it)
B
2a
A systematic review (with homogeneity) of cohort studies
2b
Individual cohort studies (including low-quality RCT, e.g., <80% follow-up)
3a
A systematic review (with homogeneity) of case-control studies
3b
Individual case-control studies
C
4
Case series (and poor-quality cohort and case-control studies)
D
5
Expert opinion without an explicit critical appraisal, or based on physiology, bench
research or “first principles”
Abbreviation: RCT, randomized controlled trials.
Summary of Key Questions and Recommendations
The summary of key questions and recommendations is displayed in [Table 2 ].
Table 2
Summary of key questions and recommendations
Key questions
Recommendations
1. How is UIS diagnosed?
1.1. Diagnosing UIS involves a comprehensive assessment comprising medical history,
physical examination, and relevant imaging results. UIS should not be considered in
the absence of supportive X-ray and MRI findings (Evidence Level 4, Recommendation
Grade C).
1.2. X-ray and MRI are recommended as the primary imaging modalities for diagnosing
UIS (Evidence Level 4, Recommendation Grade C).
2. Is conservative treatment effective for UIS?
2.1. Conservative treatment is recommended as the primary therapeutic approach for
UIS (Evidence Level 4, Recommendation Grade C).
3. What are the early surgical indications for patients with UIS?
3.1. Early surgical intervention is strongly recommended for patients with UIS experiencing
ulnar-sided wrist pain persisting for 6 months or exhibiting severe clinical symptoms
(Evidence Level 4, Recommendation Grade C).
3.2. Early surgical intervention is recommended for UIS patients with concurrent DRUJ
instability (Evidence Level 4, Recommendation Grade C).
4. What are the considerations when applying USO?
4.1. USO is a precise and recommended standard treatment for UIS (Evidence Level 2b,
Recommendation Grade B).
4.2. Caution is advised when applying USO in cases of DRUJ in reverse oblique sigmoid
(Evidence Level 4, Recommendation Grade C).
4.3. It is recommended to place internal fixation plates on the volar side of the
ulna (Evidence Level 2b, Recommendation Grade B).
5. What kind of plate is recommended to fix the osteotomy during USO surgery?
5.1. Both locking and nonlocking plates are recommended as internal fixation in USO
surgery. (Evidence Level 4, Recommendation Grade C).
6. What is the safe osteotomy length for the wafer/AWP?
6.1. It is recommended to apply wafer/AWP for UIS with the ulnar-positive variance
of <2 mm (Evidence Level 2b, Recommendation Grade B).
6.2. When the anticipated osteotomy length exceeds 3 mm, the use of wafer/AWP is not
recommended (Evidence Level 5, Recommendation Grade D).
7. When should DMUSO be considered?
7.1. Applying DMUSO for anticipated osteotomy lengths of <5 mm in UIS is recommended
(Evidence Level 4, Recommendation Grade C).
7.2. The choice of internal fixation can be determined by the osteotomy method. Preferably,
buried head compression screws are recommended as they lead to fewer postoperative
complications (Evidence Level 4, Recommendation Grade C).
8. What is the role of TFCC repair in treating UIS?
8.1. It is not recommended to solely use TFCC repair for treating UIS (Evidence Level
4, Recommendation Grade C).
8.2. For cases where DRUJ remains unstable after ulnar shortening, it is recommended
to consider concomitant TFCC foveal repair to restore DRUJ stability (Evidence Level
4, Recommendation Grade C).
9. How to treat patients with UIS with severe DRUJ arthritis?
9.1. S–K and Darrach surgeries are both recommended as salvage procedures (Evidence
Level 2a, Recommendation Grade B).
9.2. S–K surgery is more suitable for young and male patients with higher wrist joint
function requirements (Evidence Level 4, Recommendation Grade C).
9.3. Darrach surgery is more suitable for elderly patients with lower joint function
requirements (Evidence Level 4, Recommendation Grade C).
10. How about the postoperative immobilization and rehabilitation strategies for UIS?
10.1. A short-arm orthosis is suggested to be enough for immobilization for 4 weeks
after USO, with rehabilitation exercises commencing after the 4th week (Evidence Level
2b, Recommendation Grade B).
10.2. A 2-week immobilization with a short-arm splint is recommended after a wafer
procedure. Initiating exercises that involve making a fist or engaging in axial stress
training of the wrist is not advised within the first 2 weeks postoperatively (Evidence
Level 2b, Recommendation Grade B).
10.3. For DMUSO, short-arm plaster fixation for 7–10 days, followed by a switch to
a wrist brace, with rehabilitation starting on the 10th postoperative day (Evidence
Level 4, Recommendation Grade C).
Abbreviations: AWP, arthroscopic wafer procedure; DMUSO, distal metaphyseal ulnar
shortening osteotomy; DRUJ, distal radioulnar joint; MRI, magnetic resonance imaging;
S–K, Sauvé–Kapandji; TFCC, triangular fibrocartilage complex; UIS, ulnar impaction
syndrome; USO, ulnar shortening osteotomy.
Background
The TFCC serves as a crucial mechanical stabilizing structure on the ulnar side of
the wrist. Comprising fibrocartilaginous disk, dorsal and palmar radioulnar ligaments,
ulnolunate ligament, and homologous structures, the TFCC plays a primary role in stabilizing
both the distal radioulnar joint (DRUJ) and the ulnocarpal joint.[8 ]
[9 ]
During daily activities, the carpus load is shared by the radius, ulnar, and TFCC.
Approximately 80% of the carpus load is borne by the radius, while the ulnar and TFCC
handle the remaining 20% of the neutral ulnar variance.[10 ] Ulnar-positive variance occurs when the ulna is longer than the radius, with the
ulnocarpal side experiencing stress proportional to the degree of positive variance.
When ulnar-positive variance exceeds 2.5 mm, stress on the ulnar side can increase
from 20 to 40%.[11 ]
Direct impaction and increased pressure on the ulnar side, resulting from ulnar positive
variance, accelerate TFCC wear and degeneration. This can lead to thinning and even
perforation of the central portion.[12 ] Repetitive impact of the ulnar head on the lunate or triquetrum can cause pathological
changes such as chondromalacia, peeling, bone marrow edema, liquefied cystic changes,
and, in severe cases, necrosis.
It is noteworthy that wrist ulnar pressure also increases during activities such as
pronation, fist clenching, and ulnar deviation.[13 ] A retrospective case study revealed an average ulnar-positive variance of 2 mm during
pronation,[14 ] providing insights into the pathogenesis of UIS in cases without ulnar variance
in static anteroposterior X-ray view.
Question 1: How is Ulnar Impaction Syndrome Diagnosed?
Recommendation 1.1: Diagnosing UIS involves a comprehensive assessment comprising
medical history, physical examination, and relevant imaging results. UIS should not
be considered in the absence of supportive X-ray and magnetic resonance imaging (MRI)
findings (Evidence Level 4, Recommendation Grade C).
Recommendation 1.2: X-ray and MRI are recommended as the primary imaging modalities
for diagnosing UIS (Evidence Level 4, Recommendation Grade C).
Medical History and Physical Examinations
The onset of UIS is typically gradual, with patients complaining of prolonged wrist
ulnar-sided pain after maintaining a specific position. Trauma can also lead to wrist
ulnar-sided pain, prompting medical attention. The ulnocarpal stress test is a sensitive
physical examination. During the examination, the wrist is positioned in full ulnar
deviation. Axial pressure is applied to the wrist joint, while the forearm is passively
rotated through pronation to supination. The examination for UIS typically yields
a positive result in patients with this condition.[15 ] However, a positive result may also be indicative of other issues such as a TFCC
injury (without UIS), scapholunate ligament damage, or isolated arthritis.[16 ] Patients with concurrent TFCC injury may also present positive fovea signs or increased
ulnar-sided pain during rotation. Patients with unstable DRUJ may exhibit tenderness
on the dorsal aspect of the ulnar head and a positive DRUJ ballottement test.[17 ] Positive findings in the lunotriquetral ballottement test may indicate instability
in the midcarpal joint. However, given the numerous conditions causing ulnar-sided
wrist pain (approximately 20),[1 ]
[18 ] a diagnosis based solely on medical history and physical examination is insufficient.
Imaging Examination
Imaging studies should include wrist MRI[17 ] and wrist X-rays.[19 ] Wrist MRI results take precedence, followed by static anteroposterior X-ray views
or prone X-ray views of the wrist. MRI findings should include (1) increased signal
intensity in the lunate, triquetrum, or ulnar head in T2-weighted coronal MRI[20 ] ([Fig. 1A ]) and (2) thinning or perforation of the central portion of the TFCC in T2-weighted
images[21 ] ([Fig. 1A ]). Wrist X-rays typically reveal ulnar positive variance[22 ] ([Fig. 1B ]). Patients without apparent ulnar-positive variance on wrist X-rays should undergo
forearm rotation views to confirm dynamic ulnar impaction. Severe cases with cystic
changes on the ulnar side of the lunate or triquetrum may exhibit circular low-density
shadows on X-rays[20 ] ([Fig. 1B ]).
Fig. 1 (A ) T2-weighted coronal MRI demonstrates increased signal intensity in the lunate (indicated by an arrow ) and thinning and perforation of the central portion of the TFCC (marked by a triangle ). (B ) Ulnar positive variance (demarcated by red lines ) and a low-density shadow in the lunate (indicated by an arrow ) are observed in the anteroposterior view of the X-ray.
Question 2: Is Conservative Treatment Effective for Ulnar Impaction Syndrome?
Recommendation 2.1: Conservative treatment is recommended as the primary therapeutic
approach for UIS (Evidence Level 4, Recommendation Grade C).
Conservative treatment has proven effective for UIS,[23 ]
[24 ] especially during the initial diagnosis, where it should be the preferred option.[2 ] The treatment plan should include splint immobilization and symptomatic pain relief
through medication. The conservative treatment regimen typically involves continuous
splint fixation for 4 weeks and intermittent wear for 2 weeks, followed by 6 weeks
of rehabilitation after the splint removal.[23 ]
For patients experiencing significant ulnar-sided wrist pain, oral nonsteroidal anti-inflammatory
drugs (NSAIDs) can be administered for symptomatic relief. In cases of severe ulnar-sided
pain, especially when NSAIDs are not sufficiently effective, localized pain point
blockade on the ulnar side of the wrist may be considered.[25 ]
Additionally, activities that exacerbate the ulnar load, such as ulnar deviation and
forceful pronation of the wrist, should be minimized.[16 ]
Long-term splint immobilization has improved pain scores (visual analog scale [VAS])
with an overall improvement rate of 51.7%.[24 ] After 6 weeks of splint fixation and an additional 6 weeks of rehabilitation, 59%
of patients achieved a numeric rating scale score of <5, indicating successful conservative
treatment.[23 ] Conversely, 41% of patients with a score of ≥5 were considered conservative treatment
failures. For patients who do not respond positively to conservative treatment, surgical
intervention should be considered.
Question 3: What are the Early Surgical Indications for Patients with Ulnar Impaction
Syndrome?
Recommendation 3.1: Early surgical intervention is strongly recommended for patients
with UIS experiencing ulnar-sided wrist pain persisting for 6 months or exhibiting
severe clinical symptoms (Evidence Level 4, Recommendation Grade C).
Recommendation 3.2: Early surgical intervention is recommended for UIS patients with
concurrent DRUJ instability (Evidence Level 4, Recommendation Grade C).
Conservative treatment for patients with UIS often spans a lengthy period, typically
extending beyond 6 weeks, with a success rate usually <60%.[23 ]
[24 ] Identifying high-risk patients and reducing the time cost of awaiting surgery are
crucial for an early return to daily life.
Case series studies indicate that conservative treatment is often less effective when
wrist joint pain persists without improvement or when wrist joint range of motion
and grip strength are remarkably decreased. A case series followed 16 patients who
underwent ulnar shortening osteotomy (USO) due to UIS. All patients presented with
prolonged ulnar-sided wrist pain accompanied by reduced wrist joint range of motion
and weakened grip strength. Even after 6 months of conservative treatment (wrist joint
bracing and anti-inflammatory medications) with little improvement, all patients achieved
favorable outcomes following USO. Postoperatively, VAS scores, forearm rotation angles,
and grip strength significantly improved, without reported complications.[26 ] Another large-sample case series study also yielded similar findings.[25 ]
Early surgical intervention is recommended for UIS patients with concurrent DRUJ instability.[27 ] In a case series study, surgery was confirmed as a reliable method to improve UIS
with DRUJ instability. Postoperatively, patients reported an average VAS score, Quick
Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score; and Patient-Rated
Wrist Evaluation score of 0.7/10 (range, 0–4), 16.9 (range, 0–48), and 21.9 (range,
16.9–59)—all indicating significant improvements compared with preoperative values.
In this study, 96% of patients perceived themselves as improved through surgery, with
no patients reporting worsened conditions.
Question 4: What are the Considerations When Applying Ulnar Shortening Osteotomy?
Recommendation 4.1: USO is a precise and recommended standard treatment for UIS (Evidence
Level 2b, Recommendation Grade B).
Recommendation 4.2: Caution is advised when applying USO in cases of DRUJ in reverse
oblique sigmoid (Evidence Level 4, Recommendation Grade C).
Recommendation 4.3: It is recommended to place internal fixation plates on the volar
side of the ulna (Evidence Level 2b, Recommendation Grade B).
USO is one of the most common procedures for treating UIS.[12 ] This procedure involves removing a specific length of the ulna to eliminate positive
variance, reduce repetitive grinding impact between the ulna and lunate, alleviate
excessive loading on the ulnocarpal joint, and enhance DRUJ stability.[28 ]
[29 ]
USO involves osteotomy at the distal 1/3 of the ulnar shaft. The advantages of this
extra-articular surgery include not requiring the joint capsule to be opened, avoiding
DRUJ cartilage and joint surface damage, and preserving the intact TFCC structure.[30 ] A case report (n = 32) demonstrated that for patients diagnosed with UIS treated with USO, wrist joint
flexion-extension increased from an average of 82.7 to 101.2 degrees and ulnar-radial
deviation and pronation-supination significantly improved. The wrist joint VAS score
decreased from an average of 7.7 to 1.7.[12 ] Additionally, USO shortens the ulna and increases tension in the joint capsule and
surrounding ligaments, thereby enhancing DRUJ stability.[25 ]
[27 ]
[31 ]
The DRUJ sigmoid notch should be considered before applying USO. A case series of
100 cases and a biomechanical study indicated that the ulnar head may collide with
the distal radial sigmoid notch after USO in Tolat C-type DRUJ (reverse oblique sigmoid),[16 ]
[32 ] increasing contact pressure and leading to DRUJ arthritis. Therefore, caution is
advised when using USO for DRUJ with reverse oblique sigmoid.[33 ]
The influence of the osteotomy type (transverse or oblique) and the osteotomy technique
(freehand or osteotomy guide) on the union rate has been a focal point of debate in
USO procedures. Oblique osteotomy provides a larger contact surface at the osteotomy
ends, which is advantageous for healing. Screws can be inserted perpendicular to the
osteotomy surface to enhance compression at the osteotomy ends. Osteotomy guides theoretically
offer more precise control over the osteotomy length.
However, a meta-analysis involving 37 studies and 1,423 patients showed that in USO
procedures, the nonunion rates were 4.16% for transverse osteotomy and 3.86% for oblique
osteotomy, with no significant differences between the two types. The nonunion rate
for freehand oblique osteotomies was 5.06%, compared with 2.9% for oblique osteotomies
performed with an osteotomy guide. Although the nonunion rate was slightly higher
for freehand procedures, the difference was not statistically significant.[34 ] Therefore, surgeons can choose the osteotomy type and technique based on the patient's
specific condition and personal preference rather than the union rate.
Furthermore, placing the plate on the dorsal side of the ulna more likely results
in postoperative irritation.[35 ] Multiple retrospective cohort studies suggest a postoperative plate removal rate
of 45 to 65% for dorsal plates,[36 ]
[37 ] significantly lower at 25% for palmar plates.[38 ]
Question 5: What kind of Plate is Recommended to Fix the Osteotomy during Ulnar Shortening
Osteotomy Surgery?
Recommendation 5.1: Both locking and nonlocking plates are recommended as internal
fixation in USO surgery (Evidence Level 4, Recommendation Grade C).
Nonlocking and locking plates are the choice of internal fixation. Retrospective analyses
have indicated that the nonunion rates for nonlocking plates in USO procedures range
from 0 to 17.9%, with an average bone healing duration of 8.1 to 41.8 weeks.[39 ]
[40 ]
[41 ]
[42 ]
[43 ]
[44 ]
[45 ] Locking plates have shown a nonunion rate of 0 to 14.3%, with an average bone healing
duration of 7 to 11 weeks.[46 ]
[47 ]
[48 ]
[49 ] Although the nonunion rate and the bone healing duration seem to be extended with
nonlocking plates, drawing statistical conclusions remains difficult. Furthermore,
due to many inconsistencies in definitions of both nonunion and delayed union across
various studies, higher-level clinical research is required to unify these definitions
and assist surgeons in determining the optimal plate type for the USO procedure. Moreover,
biomechanical research about USO has not demonstrated a significant biomechanical
advantage for locking plates over nonlocking plates. The final destructive tests revealed
that axial rotational loading in which the locked plate is constructed failed earlier
than the nonlocked plates.[50 ] Therefore, based on the current evidence, both types of plates can be used in USO
surgery without a preference for one over the other.
Question 6: What is the Safe Osteotomy Length for the Wafer/Arthroscopic Wafer Procedure?
Recommendation 6.1: It is recommended to apply wafer/arthroscopic wafer procedure
(AWP) for UIS with the ulnar-positive variance of <2 mm (Evidence Level 2b, Recommendation
Grade B).
Recommendation 6.2: When the anticipated osteotomy length exceeds 3 mm, the use of
wafer/AWP is not recommended (Evidence Level 5, Recommendation Grade D).
The wafer procedure was first proposed in 1992[51 ] and involves the resection of 2 to 4 mm from the distal end of the ulnar head to
achieve ulnar carpal decompression.[52 ] With the advancement of arthroscopic techniques, the open wafer procedure can now
be completed arthroscopically, known as the AWP.[53 ] Intraoperatively, the 3 to 4 portal is used as the observation portal, and a burr
is placed through the 6R portal, taking advantage of the central perforation of the
TFCC to perform limited resection of the ulnar head. Research indicates that AWP and
open wafer surgery have comparable clinical effectiveness but consensus is lacking
on whether AWP offers a shorter recovery period and lower postoperative complication
rates.[12 ]
[54 ] The choice between open wafer and AWP often depends on the surgeon's expertise.
The safe osteotomy distance for the wafer has not been clearly defined. Multicenter
RCTs with high evidence grades showed that AWP in UIS patients with an average ulnar-positive
variance of ≤2.2 mm achieved satisfactory clinical outcomes comparable to the USO
group. The AWP group had no complications like DRUJ instability or arthritis during
follow-up.[55 ] Another retrospective cohort study demonstrated that AWP is effective for UIS with
an average ulnar-positive variance of 3 mm. Grip strength improvement was better than
the USO group, and the postoperative complication rate was significantly lower than
the USO group.[56 ]
However, a cadaver study indicates that increased ulnar-side pressure is significantly
positively correlated with the length of ulnar head grinding. When the ulnar head
is ground down by 1, 2, and 3 mm, ulnar-side pressure increases by 29, 57, and 86%,
respectively. Once the length of ulnar head removal reaches 4 mm, ulnar-side pressure
doubles,[57 ] and excessive ulnar-side load is a major cause of arthritis.[28 ] Therefore, considering the limited evidence, a 2 mm osteotomy length is considered
safe, but caution is advised when anticipating a 3 mm osteotomy length. When the expected
osteotomy length reaches or exceeds 4 mm, the wafer/AWP should not be used.
Since wafer/AWP prevents issues such as osteotomy, nonunion, internal fixation irritation,
and internal fixation removal, it has lower potential complications and reoperation
rates.[30 ] Thus, within the safe osteotomy range, wafer surgery can be considered an alternative
to USO.[37 ] This is particularly advantageous for UIS patients with Tolat C-type DRUJ reverse
oblique sigmoid.[55 ]
Question 7: When Should Distal Metaphyseal Ulnar Shortening Osteotomy Be Considered?
Recommendation 7.1: Applying DMUSO for anticipated osteotomy lengths of <5 mm in UIS
is recommended (Evidence Level 4, Recommendation Grade C).
Recommendation 7.2: The choice of internal fixation can be determined by the osteotomy
method. Preferably, buried head compression screws are recommended as they lead to
fewer postoperative complications (Evidence Level 4, Recommendation Grade C).
The DMUSO technique was first detailed by Slade in 2007,[58 ] although there is still no consensus on its indications and contraindications.[59 ] A case series study involving 43 patients found that DMUSO,[60 ] with over 6 months of follow-up, demonstrated satisfactory clinical outcomes for
ulnar-positive variance within 5 mm. It significantly improved grip strength and dorsal
extension angle of the wrist. However, evidence for ulnar-positive variance at or
≥5 mm is currently lacking, even though a cadaveric study suggests that DMUSO may
have a similar or longer osteotomy distance compared with USO.[61 ] Researchers observed that DMUSO was more effective than USO in relieving pain and
Quick-DASH scores were higher.[62 ] Additionally, due to the distal location of the osteotomy in DMUSO, it reduced the
separation and traction effects of the interosseous membrane on the osteotomy ends.
With a rich blood supply in the distal metaphysis, DMUSO required a shorter healing
time and had a lower nonunion rate compared with USO.[59 ] Currently, no reported evidence has regarded contraindications for DMUSO based on
a search of multiple databases.
For DMUSO fixation, either buried head compression screws (wedge osteotomy) or ulnar
distal plates (transverse osteotomy) can be chosen based on the osteotomy's morphology.
Both fixation methods can achieve good bone healing results. A case report using ulnar
distal plate fixation revealed that, despite 4% of patients experiencing delayed healing
due to early postoperative activity, satisfactory healing results were eventually
achieved. About 32% of patients experienced internal fixation irritation postoperatively,
resulting in a secondary internal fixation removal surgery approximately 7 months
later but the subsequent modification of the plate significantly reduced the incidence
of postoperative internal fixation irritation.[28 ] Conversely, buried head compression screws had rare reports of postoperative internal
fixation irritation and secondary surgery for removal. The fixation method is flexible,
allowing either retrograde fixation from the ulnar head cartilage surface to the distal
end or antegrade fixation from the ulnar shaft to the ulnar head. The number of screws
can be a single or double fixation.[58 ]
[59 ]
[63 ] A cadaver study indicated that two antegrade screws provided the highest resistance
to rotation stability while avoiding damage to the joint surface caused by internal
fixation.[63 ]
[64 ]
Question 8: What is the Role of Triangular Fibrocartilage Complex Repair in Treating
Ulnar Impaction Syndrome?
Recommendation 8.1: It is not recommended to solely use TFCC repair for treating UIS
(Evidence Level 4, Recommendation Grade C).
Recommendation 8.2: For cases where DRUJ remains unstable after ulnar shortening,
it is recommended to consider concomitant TFCC foveal repair to restore DRUJ stability
(Evidence Level 4, Recommendation Grade C).
Patients with UIS frequently have concomitant TFCC injuries. Current clinical studies
confirm that performing only TFCC debridement and repair does not effectively alleviate
ulnar-sided wrist pain in patients with confirmed UIS. A case series involving 163
patients found that approximately 25 to 30% of patients with UIS who underwent only
TFCC debridement and repair needed subsequent USO treatment within 3.6 months postoperatively.[65 ] A retrospective cohort study involving 72 cases reported that repairing TFCC alone
could provide short-term ulnar-positive variance improvement. However, over time (average
follow-up of 26.8 weeks), ulnar-positive variance tended to worsen again,[66 ] accompanied by ulnar-sided wrist pain. In contrast, ulnar shortening surgery effectively
improved clinical symptoms in patients with UIS. An analysis revealed that for patients
with UIS with TFCC central perforation or radial edge tears that cannot be sutured
and repaired, performing only USO achieved clinical results comparable to USO combined
with TFCC debridement. No significant differences in postoperative hand function scores,
grip strength, and pain relief were observed between the two groups.[67 ] Even in patients with UIS with minor TFCC injuries and DRUJ instability, most of
them achieved significant improvement in DRUJ stability through USO.[68 ] The mechanism has been elucidated quite clearly.[29 ]
[69 ] For patients with persistent DRUJ instability after shortening, a combined procedure
is needed to repair the TFCC foveal to restore DRUJ stability.[28 ]
[68 ]
Specialists must note that some patients present with ulnar-sided wrist pain, DRUJ
instability, and ulnar-positive variance in clinical practice. Moreover, primary UIS
should be differentiated from secondary ulnar-positive variance due to DRUJ instability.
The treatment approaches for these conditions differ. Primary UIS requires high signal
intensity, thinning, or even central perforation of the TFCC that can usually be identified
on MRI. If ulnar-positive variance is caused by DRUJ instability, patients typically
have a clear history of trauma. MRI commonly shows no obvious signal changes in the
ulnar-positive variance, and TFCC injuries are more concentrated in the ulnar-sided
fovea, rather than central perforations. A case series study involving 140 patients
reported that TFCC deep support injuries could increase ulnar-positive variance by
0.56 mm. After restoring DRUJ stability through repair, the ulnar-positive variance
was reduced from 0.56 to 0 mm.[70 ] Therefore, detailed history taking, thorough physical examination, and careful image
interpretation are essential.
Question 9: How to Treat Patients with Ulnar Impaction Syndrome with Severe Distal
Radioulnar Joint Arthritis?
Recommendation 9.1: Sauvé–Kapandji (S–K) and Darrach surgeries are both recommended
as salvage procedures (Evidence Level 2a, Recommendation Grade B).
Recommendation 9.2: S–K surgery is more suitable for young and male patients with
higher wrist joint function requirements (Evidence Level 4, Recommendation Grade C).
Recommendation 9.3: Darrach surgery is more suitable for elderly patients with lower
joint function requirements (Evidence Level 4, Recommendation Grade C).
Darrach and S–K surgeries are currently the two most widely used salvage procedures
for wrist joint function restoration.[71 ] In patients with severe DRUJ arthritis, limited forearm rotation in UIS, where USO
and wafer procedures fail to alleviate symptoms such as pain, grip strength, and reduced
joint mobility, Darrach surgery involving the removal of the entire ulnar head[72 ] or S–K surgery, which includes partial osteotomy of distal ulnar and DRUJ fusion,[73 ] becomes necessary to improve forearm rotation function and wrist pain.
Darrach surgery involves the complete removal of the ulnar head to alleviate wrist
pain caused by arthritis. However, due to the loss of ulnar head support, complications
such as volar or dorsal instability of the radiocarpal joint, ulnar deviation of the
wrist joint, and impingement between the residual ulna and the radial aspect may occur.[74 ]
With a deeper understanding of TFCC, researchers have realized the importance of preserving
TFCC for maintaining DRUJ stability. S–K surgery, by retaining the ulnar head and
TFCC along with surrounding ligamentous structures, provides better rotational and
axial stability compared with Darrach.[74 ] However, due to DRUJ fusion, postoperative complications such as delayed healing,
nonunion, or pseudoarthrosis increase, resulting in a higher overall complication
rate compared with Darrach. Additionally, when ulnar shortening exceeds 5 mm, it may
induce painful instability of the ulnar stump.[75 ] Currently, the management of painful instability of the ulnar stump involves ulnar
head replacement[76 ] or DRUJ replacement.[77 ]
A retrospective analysis involving 1,267 patients demonstrated that surgeons were
more inclined to perform S–K surgery on younger and male patients.[78 ] Patients undergoing S–K surgery were 5 to 18 years younger than those undergoing
Darrach surgery.[79 ]
[80 ]
[81 ]
[82 ] This preference might be attributed to the fact that S–K surgery preserves ulnar
structures, maintaining ulnar stress transmission and considering grip strength improvements.
Conversely, Darrach surgery is more common in females aged over 56 years, aiming to
avoid several complications associated with S–K surgery. A systematic review of 47
studies found that both S–K and Darrach surgeries significantly improved forearm rotational
mobility; however, the return-to-work rate was notably higher for S–K surgery (86
vs. 63%).[71 ]
Question 10: How about the Postoperative Immobilization and Rehabilitation Strategies
for Ulnar Impaction Syndrome?
Recommendation 10.1: A short-arm orthosis is suggested to be enough for immobilization
for 4 weeks after USO, with rehabilitation exercises commencing after the 4th week
(Evidence Level 2b, Recommendation Grade B).
Recommendation 10.2: A 2-week immobilization with a short-arm splint is recommended
after a wafer procedure. Initiating exercises that involve making a fist or engaging
in axial stress training of the wrist is not advised within the first 2 weeks postoperatively
(Evidence Level 2b, Recommendation Grade B).
Recommendation 10.3: For DMUSO, short-arm plaster fixation for 7 to 10 days, followed
by a switch to a wrist brace, with rehabilitation starting on the 10th postoperative
day (Evidence Level 4, Recommendation Grade C).
Patients undergoing different surgeries for UIS have varying durations of joint immobilization
and different timings for rehabilitation. USO is the most commonly used procedure;
however, its severe complication, nonunion, occurs at a rate of 4 to 18%.[25 ]
[34 ]
[83 ] Nonunion of fractures is a complex outcome influenced by multiple factors. It is
difficult to make immediate predictions during or right after surgery. There is also
no consensus on whether early plaster, brace, or orthosis fixation postoperatively
can truly reduce the incidence of fracture nonunion after USO. A case series involving
106 patients indicates that early long-arm plaster fixation can effectively reduce
rotational stress on the fracture ends, promoting fracture healing.[84 ] This involves wearing a long-arm plaster for the first 2 weeks and a long-arm thermoplastic
orthosis for the next 2 to 4 weeks, with wrist flexion/extension exercises starting
from the 2nd week and forearm rotation exercises starting after the 6th week. Refixation
was performed in six patients (6%) because of nonunion. They also reported that six
patients were not smokers. The reason for nonunion was not clearly clarified in the
“Discussion” section. Another multicenter RCT demonstrates that short-arm plaster
is sufficient for post-USO fixation.[55 ] In this study, a short, below-elbow orthosis was used for 2 weeks and switched to
another thermoplastic orthosis for 2 weeks, with digital exercises immediately after
the surgery and wrist joint rehabilitation training starting from the 4th week. Ultimately,
all patients showed significant improvements in wrist joint mobility and joint function
scores, without nonunion or joint stiffness.[55 ] Some reports also advocate early functional exercises, with incomplete short plaster
fixation for 12 days and the initiation of rehabilitation exercises after plaster
removal, showing no cases of nonunion.[85 ] However, an issue of nonunion has also been reported with too early activity. A
retrospective cohort study involving 40 patients reported that immediate wrist movement
after the USO resulted in a 10% rate of nonunion.[86 ] Based solely on the current evidence available, a definitive recommendation regarding
early immobilization after the USO surgery cannot be established. Therefore, for early
fixation following USO, we have used the term “suggest.” Regardless of the chosen
fixation method, early active movement is advocated for all nonfixed joints postoperatively.
This not only avoids impacting bone healing[85 ] but also promotes reduced swelling.[48 ]
Notable differences were observed in postoperative immobilization strategies across
various studies referring to wafer procedures. A retrospective case report involving
12 patients indicated that initiating immediate postoperative wrist rotational and
flexion-extension rehabilitation exercises resulted in a 58% rate of pain relief.[86 ] Conversely, a retrospective cohort study involving 33 patients found that immobilizing
the wrist with a volar splint for 10 days postwafer surgery yielded an average VAS
score of <1.[30 ] Thus, although the wafer procedure does not require a union process, a short-term
postoperative cast is deemed necessary. Another retrospective case report of 12 patients
who began rotational exercises and forceful gripping after the 1st week of postwafer
surgery showed a 67% improvement rate in the VAS score.[87 ] Another retrospective analysis involving 26 patients reported that adopting a 2-week
immobilization period followed by the commencement of rehabilitation exercises starting
in the 3rd week postoperatively resulted in an 84.6% improvement rate in the VAS score.[88 ] Therefore, rehabilitation exercises involving forceful gripping within the 1st week
postoperatively may potentially result in negative effects on pain improvement.
An RCT with a sample size of 60 utilized a 4-week postoperative short-arm cast immobilization
strategy followed by rehabilitation exercises. The postoperative wafer group saw a
reduction in VAS scores from an average of 6.5 preoperatively to 0.7 postoperatively,
with grip strength on the affected side improving from 66 to 87% compared with the
unaffected side.[55 ] Another retrospective cohort study implemented a postoperative strategy that involved
a 2-week fixation with a short-arm plaster cast, followed by an additional 4-week
immobilization using a thermoplastic splint. Rehabilitation training aimed at restoring
joint mobility was encouraged beginning in the 3rd week. It was not until the 7th
week that exercises such as making a fist and axial loading were initiated. This approach
resulted in an 84.6% improvement rate in pain outcomes.[89 ] While there are longer immobilization strategies exceeding 6 weeks, the absence
of case data precludes comparison.[63 ]
Due to richer blood supply in the distal metaphysis, the probability of postoperative
nonunion was lower in DMUSO than in USO,[90 ] requiring a shorter fixation time and earlier intervention in wrist joint rehabilitation.
A case series (n = 8) indicates that after DMUSO, wearing a long-arm plaster for 7 to 10 days, patients
can switch to a removable splint for protection and begin hand function rehabilitation
training, achieving 85 to 99% of wrist joint flexion, extension, and rotational mobility
at 13 months postoperatively compared with the unaffected side. The grip strength
increased to 88% of the healthy side afterward. No nonunion occurred postoperatively.[59 ] Another case series, with a sample size of 43 patients, reported that patients were
immobilized postoperatively using a sugar-tong splint for 3 weeks. Following the removal
of the splint, rehabilitation exercises were initiated. A statistically significant
improvement in patients' grip strength was observed, which increased on average from
77% of the healthy side preoperatively to 87% of the healthy side afterward. The range
of motion in wrist extension also showed statistically significant improvement (from
63.1 degrees preoperatively to 69.1 degrees postoperatively). The successful union
was achieved as expected postoperatively in all patients.[60 ]
