Keywords arthrodesis - wrist joint - wrist
Introduction
Whether for strength or precision activities, functional use of the hand depends on
a stable and painless wrist. Instability and pain imply impairment of function and
require treatment.[1 ] Total wrist arthrodesis (TWA) is a well-established procedure that results in predictable
pain relief and satisfactory function in patients with inflammatory, degenerative,
and post-traumatic pathologies.[2 ]
The main indication for TWA is an active individual who suffers from radiocarpal and
midcarpal arthritis, remaining symptomatic after conservative treatment and has no
indication for procedures that preserve wrist mobility.
Patients undergoing TWA show decreased pain and improved grip strength and quality
of life. It is reasonable to think that pain is one of the causes of the reduced grip
strength of the affected limb and, consequently, it increases the risk of the patient
presenting dysfunction in routine tasks.
The study aims to demonstrate a new evaluation method, which consists of an objective
analysis of handgrip and pinches strength after intra-articular block with anesthetic,
to predict the functional success of TWA and assist its indication. It also can give
the patient a prediction of the outcome of the surgery.
Methods
This study was approved by our institutional review board (CAAE 34609220.6.0000.5440).
The patient and his family were informed that data from the case would be submitted
for publication and gave their consent.
Twenty patients with an indication of total wrist arthrodesis were prospectively evaluated.
Inclusion criteria were patients with posttraumatic wrist arthritis. Exclusion criteria
were patients who lost postoperative follow-up or incomplete information in the medical
record. Thus, only ten patients were eligible for this study. The statistical power
was analyzed and adequated to the sample size, being necessary for ten patients for
a confidence interval of 95% (McNemar's Z-test, 1-Sided).
Functional assessment of the wrist was performed in three moments: (1) before surgery
without joint anesthesia; (2) before surgery under joint anesthesia; (3) and after
at least 12 weeks after the surgical procedure.
Clinical Evaluation
The functional assessment consisted of applying the Visual Analogue Scale (VAE), the
Patient Rated Wrist Evaluation (PRWE) 37, and the Disabilities of the Arm, Shoulder,
and Hand (DASH) 38 (Appendix I and II). The handgrip strength test and three digital
pinches (pulp-pulp, lateral, and tripod) were performed with a pinch meter ([Fig. 1 ]).
Fig. 1 Preoperative assessment. A. Handgrip dynamometer. B. Lateral pinch. C. Tripod pinch.
D. Pulp-pulp pinch.
Radiocarpal Joint Anesthesia
After identifying the Lister's tubercle on the dorsal surface of the radius and, between
the third and fourth extensor compartment, approximately 1cm distal to the tubercle,
a soft spot corresponds to where the needle was inserted into the joint. Then, 5 mL
of 1% lidocaine without vasoconstrictor in the radiocarpal joint of the affected wrist.
Operative Technique
The surgeries were all performed by the same surgeon (second author). The surgical
technique was no different from the one commonly used in the service and widely described
in the literature.[2 ]
[3 ]
[4 ]
Under anesthesia (regional brachial plexus, general inhalation or combined), the affected
wrist was approached through a dorsal longitudinal incision—the extensor retinaculum,
between the 3rd and 4th compartments, was opened. The joint capsule was incised longitudinally,
and Lister's tubercle was resected to be used as a bone graft. The articular surfaces
between the radius, scaphoid, lunate and capitate are carefully removed, avoiding
excessive resection of the cancellous subchondral bone. The low-contact titanium wrist
arthrodesis plate (TechImport®, Rio Claro, São Paulo, Brazil) was placed and fixed
according to the dynamic compression technique.
Postoperative
A volar plaster immobilization was placed after the surgery. The stitches were removed
at 10-14 days; the immobilization was then changed for a wrist orthosis for ten weeks.
During this time, the patient was allowed passive and active finger flexion and extension
and wrist pronation and supination of the forearm. We evaluated the radiographic images
every two weeks, and strength exercises were introduced only after radiographic confirmation
of the arthrodesis consolidation.
A two-tailed p-value of less than 0.05 was considered statistically significant. All
analyses were performed using SPSS for Os X, version 22.0.0 (SPSS, IBM Corp., NY).
Results
Twelve patients who underwent total wrist arthrodesis were included ([Fig. 2 ]). We excluded two of them due to loss of follow-up. The data were obtained through
evaluations of the ten patients. [Table 1 ] includes all the mean strength (in Kgf) measured and consists of an assessment of
the unaffected limb, which presents, on average, more than twice the strength of the
diseased wrist before surgery in the handgrip.
Fig. 2 Total Wrist Arthrodesis. A. Anteroposterior view. B. Lateral view.
Table 1
Handgrip Strenght
Tripod Pinch
Lateral Pinch
Pulp-pulp Pinch
Before Anesthesy
15,57
4,33
5,67
3,63
After Anesthesy
21,00
6,27
7,87
5,33
Post Operative (12 Months)
18,83
5,57
6,47
4,97
Contralateral (unnafected side)
39,17
7,87
9,87
6,47
p-value (Student T-test)
0.002
0.007
0.007
0.006
The handgrip and pinch strength increased after pain relief. In all parameters evaluated,
the most expressive increase in strength occurred under the effect of the anesthetic,
showing a statistical difference when compared to the state before the blockade for
handgrip (Student T-test: p = 0.022), tripod pinch (Student T-test: p = 0.007), lateral
pinch (Student T-test: p =0.007) and pulp-pulp pinch (Student T-test: p = 0.006).
When comparing preoperative evaluations without anesthesia with the results acquired
12 weeks after the surgical procedure, patients showed substantial improvement in
subjective assessment (DASH, PRWE and VAS) with statistical significance (Student
T-test: p < 0.05). It was also possible to confirm the increased handgrip strength
and tripod pinch after surgery concerning preoperative measurements (Student T-test:
p < 0.05). Even with an improvement trend, there was no statistical significance for
pulp-pulp pinch (Student T-test: p = 0.087) and lateral pinch (p = 0.374). These data
are available in [Table 2 ].
Table 2
Case
Pain VAS Preoperative
Pain VAS Postoperative
DASH Preoperative
DASH Postoperative
PRWE Preoperative
PRWE Postoperative
1
7
0
45
27,5
48
38,5
2
2
0
53,3
30
74,5
61,5
3
8
1
96,7
57,5
94
63
4
6
0
40,8
35,8
63
48
5
5
3
61,7
21,7
83,5
43,5
6
6
0
68,3
33,3
82
65,5
7
8
0
73,3
40,8
80
42
8
7
0
70,8
39,2
82,5
55
9
7
0
66,7
22,5
70,5
35
10
3
0
68,3
27,5
63
38.5
p Value[* ]
0.0002
0.0003
0.0008
When comparing the mean strength values found after anesthesia and 12 weeks after
performing total wrist arthrodesis, there was no statistical difference for any of
the items evaluated.
There were no complications reported, and all the TWA presented bone fusion. None
of the patients had suture dehiscence, tendon rupture, nerve damage, superficial or
deep infection or union failure.
Discussion
There were improvements in function and quality of life comparing the preoperative
and postoperative scores (DASH, PRWE and EVA) and correlating handgrip and pinch strength.
Several other studies prove the analgesic effect of this procedure. Other studies
reported a complete decrease in pain after total wrist arthrodesis in 76 to 100% of
cases.[5 ]
[6 ]
[7 ]
[8 ]
[9 ]
[10 ]
[11 ]
[12 ]
Other authors demonstrate the relationship between the decrease in muscle strength,
measured by handgrip strength, with a greater chance of developing incapacity to perform
daily activities, which clarifies the significant functional impact.[13 ]
[14 ]
[15 ]
[16 ]
[17 ]
[18 ]
[19 ]
[20 ]
[21 ]
[22 ]
[23 ]
[24 ]
[25 ]
[26 ]
[27 ]
[28 ]
[29 ]
[30 ] Sauerbier et al.[15 ] measured the grip strength of patients with indication for total wrist arthrodesis
due to post-traumatic arthrosis or Kienbock's disease, showing a 50% reduction concerning
the healthy side. These data are similar to those found in our study, which demonstrated
a mean decrease in grip strength of more than 100% compared to the unaffected side
([Table 1 ]).
The study aimed to establish a predictability factor for functional outcomes based
on the response to the preoperative anesthetic block. The use of anesthetics as a
preoperative evaluation for arthrodesis remains unclear in the literature. Stegeman
et al.[4 ] correlated the joint function after preoperative anesthesia with the functional
outcomes after ankle arthrodesis. They concluded that the anesthetic block was not
valuable as a diagnostic tool since patients that underwent surgery had good functional
results regardless of the result of the anesthetic block.
The main question about total wrist arthrodesis is, “Why is a preoperative test to
evaluate pain relief necessary if that's the goal of the procedure?”. The answer is
that some patients still complain about wrist pain or other symptoms after the total
wrist fusion. There are pain symptoms in the DRUJ (Distal RadioUlnar Joint); there
is residual pain over the 4-5th carpometacarpal joint and thumb basal joint symptoms. Once the wrist arthritis begins,
the progression of carpal degeneration will still occur.
In our evaluation, when comparing preoperative strength averages after anesthetic
blockade with strength averages 12 weeks after the procedure, there was no statistical
difference, showing similarity between the results and a possibility of prediction
of the outcome with a simple procedure.
A limitation of the study was that all patients showed improvement in symptoms and
strength after the anesthetic blockade, thus avoiding the formation of a group to
compare results after arthrodesis. The continuation of the study with a consequent
increase in the number of cases may add this variable.
Conclusion
We conclude that our results could propose a new preoperative assessment protocol
for patients with TWA indication. Patients who present an excellent response to intra-articular
anesthetic infiltration would benefit from the effects of the surgical procedure.
The increase in the sample is essential to establish more reliable parameters.
