Keywords
ulnar shortening osteotomy - ulnar impaction syndrome - triangular fibrocartilage
complex - chondromalacia
Ulnar impaction syndrome was described by Friedman and Palmer[1] as degenerative changes of the ulnar aspect of the wrist in patients with positive
ulnar variance either static or dynamic. The chronic load between the ulnar head,
the triangular fibrocartilage complex (TFCC), and the ulnar carpus results in cartilaginous
lesions of the lunate and ulnar head, lunatotriquetral ligament disruption, and degeneration
of the TFCC.[2]
[3]
[4]
Ulnar impaction syndrome is either idiopathic or secondary. In patients with congenital
or dynamic positive ulnar variance with wrist pronation and forceful grip with no
history of fracture or premature physael arrest, the condition is termed idiopathic.
Patients suffering from ulnar impaction syndrome report ulnar-sided wrist pain exacerbated
by forearm rotation or ulnar deviation of the wrist during daily activities.[5]
The characteristic plain radiographic findings associated with idiopathic ulnar impaction
syndrome include positive ulnar variance and radiographic carpal chondromalacia, evidenced
by cortical sclerosis or subchondral changes consistent with cystic changes in the
ulnar head, ulnar corner of the lunate, and/or radial corner of the triquetrum.[5]
[6] Progressive abutment of the ulnocarpal junction may result in progressive cartilaginous
erosions of the lunate and ulnar head, lunatotriquetral ligament disruption, and degeneration
of the TFCC.[2]
[3]
[4]
Ulnar shortening osteotomy is the method of choice to decompress the ulnocarpal joint
to relieve the symptoms of ulnar impaction by restoring neutral or negative ulnar
variance.[4]
[6] A variety of surgical techniques have been described, with the goal of optimizing
the ulnar variance. This article reports the outcomes of ulnar shortening osteotomy
using a dynamic compression system after creation of an oblique ulnar diaphyseal osteotomy
in a freehand technique and placing the plate on the ulnar surface of the ulna to
avoid disturbing the muscle originating from the volar or dorsal surface of the ulna
and making use of the flat ulnar surface which accommodate the plate with minimal
soft tissue dissection.
Materials and Methods
After review approval, we performed a retrospective review of patients diagnosed with
ulnar impaction syndrome. We identified 38 patients who have ulnar shortening osteotomy
with locked dynamic compression plate at our institution between 2010 and 2014. Inclusion
criteria includes patient with positive ulnar variance of at least 2 mm, with evidence
of ulnar impaction lesions on magnetic resonance imaging like chondromalacia of the
lunate, triquetrum with failure of conservative treatment over a period of 6 months.
Patient with secondary ulnar impaction syndrome, that is, malunited distal radius
(three cases) or Madelung's deformity (two cases), were excluded. Six patients were
excluded from the study either because of associated secondary pathology which was
operated (four cases) or they do not show up in the follow-up clinics (two cases).
A total of 27 patients were included in this study, 19 females and 8 males. The average
age was 50 (18–79, SD 15) years. The dominant hand was affected in 18 patients. The
mean follow-up period was 30 (12–47) months.
We performed wrist arthroscopy for all the patients immediately before the osteotomy
to evaluate the condition of the TFCC, the lunatotriquetral interosseous ligament,
and the condition of the lunate and triquetrum articular surfaces. The osteotomy was
done using the freehand technique and the ulnar shortening plate was placed on the
ulnar surface of the ulna. The patients were immobilized after surgery in a short
arm splint for 6 weeks, and physiotherapy was performed on the patients out of the
splint from day 1, including rotational movement postoperatively.
Subjective and objective assessment includes visual analog scale (VAS) pre- and postoperatively
in which 0 represented no pain and 10 represented severe pain. The Disabilities of
the Arm, Shoulder, and Hand (DASH) questionnaire was used to evaluate the upper extremity
function pre- and postoperatively.
Active range of motion (ROM) included wrist flexion/extension for the affected and
contralateral limbs and forearm pronation/supination for the affected and contralateral
limbs.
Grip strength (Jamar Hydraulic Hand Dynamometer, Jamar Technologies) was evaluated
for both limbs, without correction for hand dominance. These measures were recorded
for the 27 patients who maintained regular follow-up appointments. Intraoperative
information or postoperative complications was also retrieved from the patient database.
Radiological assessment of the forearm with wrist joint in two views was performed
after 6 to 18 weeks and at final follow-up. We assessed the consolidation and nonunion
rate radiologically. We also analyzed complication of the surgery.
Variations in the outcome within the study group were assessed statistically using
one-way analysis of variance (ANOVA). Statistical significance was accepted at p < 0.05 level (StatPlus: statistical analysis program for Mac OS, Version 2009).
Surgical Technique
An ulnar incision of 8 cm long is made starting 5 cm proximal to the ulnar head, opening
the fascia between flexor and extensor carpi ulnaris muscle, and identifying the ulnar
surface of the ulna without disturbing the muscle origin from the volar or dorsal
surface of the ulna ([Fig. 1]). The locked plate is applied on the ulnar surface of the ulna and the plate orientation
is confirmed using fluoroscopy ([Fig. 2]). Distal locked screws are drilled and inserted in the first and third hole, and
two proximal cortical screws are applied in the proximal aspect of the gliding hole
without tightening the screw to the far cortex ([Fig. 3]).
Fig. 1 Approach and exposure of the ulna.
Fig. 2 Application of the ulnar osteotomy plate.
Fig. 3 The osteotomy site is well marked.
The osteotomy level is identified and marked and the plate is temporarily removed.
Minimal dissection is performed and muscle fibers are removed from the osteotomy site,
and Homan's test is applied to protect the volar and dorsal soft tissue ([Figs. 4] and [5]). Osteotomy is done at the previously marked level with cooling and the amount of
bone removed depended on the preoperative measurements ([Fig. 6]). The plate is reapplied and the previously drilled distal locking screws are inserted,
and then the proximal placed screws are reinserted without tightening. A reduction
clamp is used to close the osteotomy ([Fig. 7]), and then the most proximal cortical screw is tightened ([Fig. 8]). And then the insertion of the proximal and distal screws is completed. At the
end, the lag screw is drilled and inserted at 60° angle across the osteotomy site
([Fig. 9]). The amount of shortening achieved is confirmed using fluoroscopy ([Figs. 10], [11A–C], and [12]), and closed in layers and a forearm slab applied.
Fig. 4 Distal osteotomy.
Fig. 5 Proximal osteotomy.
Fig. 6 Osteotomy site after removal of the bone.
Fig. 7 Compression of the osteotomy site.
Fig. 8 Insertion of the proximal and distal screws.
Fig. 9 Application of the lag screw.
Fig. 10 Preoperative X-ray showing ulnar impaction.
Fig. 11 (A–C) Intraoperative X-ray after osteotomy.
Fig. 12 Postoperative X-ray.
Results
12 palmer 2C tears, 5 2D, 5 2B, 3 2E and two patients 2A are shown in [Tables 1] and [2]. These injuries were treated with arthroscopic debridement followed by the ulnar
shortening osteotomy.
Table 1
Arthroscopic palmer classification
|
Palmer classification
|
Number of patients
|
|
IIA
|
2
|
|
IIB
|
5
|
|
IIC
|
12
|
|
IID
|
5
|
|
IIE
|
3
|
Table 2
Outerbridge stage of lunate chondromalacia through arthroscopy
|
Outerbridge staging
|
Number of patients
|
|
I
|
5
|
|
II
|
14
|
|
III
|
5
|
|
IV
|
3
|
The mean VAS improved from 7 (range, 3–10; SD, 2) preoperatively to 3 (range, 0–10;
SD, 3) postoperatively. Function measured with the DASH score had improved from 45
(range, 20–71; SD, 14) to 18 (range, 0–62; SD, 18) ([Table 3]).
Table 3
Clinical outcomes after ulnar shortening osteotomy
|
Preoperative mean, range, and SD
|
Postoperative mean, range, and SD
|
p-Value
|
|
Ulnar variance
|
2.5 (2–4.2; 0.6)
|
0.3 (0–1; 0.4)
|
<0.05
|
|
VAPS
|
7(3–10; 2)
|
3 (0–10; 3)
|
<0.05
|
|
DASH score
|
45 (20–71; 14)
|
18(0–62; 18)
|
<0.05
|
Abbreviations: DASH score, Disabilities of the Arm, Shoulder, and Hand score; VAPS,
visual analog pain score; SD, standard deviation.
The average ROM in flexion and extension was 95% of the contralateral side and in
forearm rotation, and the average range of pronation was 96% of the contralateral
side and in supination was 93% of the contralateral side ([Table 4]).
Table 4
Postoperative range of motion compared with the opposite side
|
Postoperative
|
Contralateral (%)
|
|
Wrist flexion
|
65°
|
95%
|
|
Wrist extension
|
70°
|
95%
|
|
Forearm pronation
|
82°
|
96%
|
|
Forearm supination
|
78°
|
93%
|
Mean grip strength at last follow-up was 87% compared with the contralateral side
(range, 30–100%).
Mayo wrist score showed 12 excellent, 7 very good, 3 satisfactory, and 4 poor results.
The amount of ulnar shortening was between 2 and 4 mm. The operation time for the
ulnar shortening osteotomy was 39 minutes in average (range, 31–50; SD, 4).
Note that 23/27 of our patients were satisfied with the results and would agree to
do the operation once more. No patient in our study group has to change his job or
preoperative activities.
We had six complications. Three patients suffered irritation from plate prominence
at 1 year. One showed nonunion and revision was done. Two patients complained of persistent
ulnar-sided wrist pain. After exclusion of the nonunion case, the average time to
union after ulnar shortening osteotomy was 8 weeks (range, 6–18 weeks).
Discussion
In this series, we obtained excellent clinical outcomes in ulnocarpal impaction syndrome
with our technique. The postoperative ROM was not less than 95% of the contralateral
side. The VAS improved from average of 7 preoperatively to 3 postoperatively, with
16/26 (60%) of patients reporting to have no or very mild pain ([Table 5]).[7] Many techniques of ulnar shortening osteotomy were described by different authors,
with variations in the location, orientation of the osteotomy, and variation in plate
positioning regarding size and location. The standard method is performing diaphyseal
osteotomy, but several authors reported good results with metaphyseal osteotomy as
well, reporting better union rates and less soft tissue irritation.[8]
[9]
[10]
Table 5
Comparison with other studies in the literature
|
No
|
Follow-up (mo)
|
Nonunion (n)
|
Plate removal
|
Flexion
|
Extension
|
Pronation
|
Supination
|
Grip strength (kg)
|
|
Our study
|
27
|
30
|
1 (2.5)
|
3(11%)
|
58°
|
64°
|
82°
|
78°
|
23
|
|
Ahsan et al[17]
|
30
|
8
|
2 (7%)
|
4(13%)
|
74°
|
65°
|
77°
|
73°
|
26
|
|
Das De et al[20]
(Dorsal plating)
|
16
|
12
|
0 (0%)
|
1(6%)
|
68°
|
68°
|
79°
|
76°
|
31
|
|
Das De et al[20]
(Volar plating)
|
18
|
12
|
2 (11%)
|
6(33%)
|
68°
|
59°
|
70°
|
73°
|
20
|
Diaphyseal osteotomies have the advantage of improving radioulnar stability because
of the tensioning effect on the distal interosseous ligament.[11] Oblique,[12] transverse,[13] and step-cut osteotomy have been described.[8]
Rayhack et al[14] showed a significantly shorter time to union with oblique osteotomy. Wehbé and Cautilli[15] reported similar healing times with a transverse osteotomy.
Most studies reported using 3.5-mm or similarly sized plates.[7]
[8]
[12]
[14]
[16] Chun and Palmer[12] recommended dorsal plate placement, whereas others advocate volar plate placement.[13]
[16]
In this study, we present a technique with ulnar plate placement, with the advantage
of minimal soft tissue dissection, which might have a positive effect on healing in
addition to minimizing the operation time. Our average operation time was minimized
the irritation of the flexor carpi ulnaris and ulnar sided flexor digitorum profundus
tendons, the postoperative grip strength.
Another advantage is to minimize the possible screw irritation of the volar or dorsal
muscle mass by the application of the plate on the ulnar surface.
Although volar plate application is recommended by several authors,[13]
[16] painful hardware irritation was found. In the study of Ahsan et al,[17] 4 of 30 (13%) patients required plate removal. Loh et al[4] in a review of 22 patients did plate removal for 7 patients (32%). Chen and Wolfe[16] reported that 8/18 (44%) of the patients requested plate removal. Pomerance[18] removed plates in 14 of 40 patients (35%), and Lauder et al[19] reported 4 cases (24%) of plate removal in a cohort of 17 patients. Not only can
the volar plate application cause scarring and soft tissue irritation of the muscle
mass but it can also cause persistent neuropathic changes of the dorsal sensory branch
of the ulnar nerve which can require revision surgery.
In this study, we had only three cases of plate removal (11%), which is of lower percentage
compared with the former studies and no case of ulnar nerve neuropathy was reported.
Another advantage is to use the anatomical flat surface of the ulna at this location,
which can easily accommodate the ulnar shortening compression plate with slight contouring
to increase compression.
The incidence of nonunion after ulnar shortening osteotomy has been reported in up
to 13% cases in a study by Koppel et al.[21] In another study, Rayhack et al[14] reported one case of nonunion in a cohort of 17 patients (6%). Ahsan et al,[17] in his study, reported nonunion after ulnar shortening osteotomy in 2/30 (7%) of
his patients. In this study, we had only one case of nonunion in the 38 cases identified
(2.5%).
One limitation of this study is the small sample size. Another limitation is the absence
of a control group. The patients in this study had persistent ulnar-sided wrist pain
with radiographic evidence of positive ulnar variance and ulnar impaction lesions.
These patients' symptoms were refractory to conservative therapy. However, as discussed
by McBeath et al,[22] symptomatic improvement following ulnar shortening osteotomy cannot be definitively
attributed to the surgical intervention, as it may be the natural course of the illness,
or the placebo effect. That is why a randomized, controlled trial with a larger patient
population is needed to distinguish between surgical and nonsurgical techniques.
