Facioscapulohumeral dystrophy is a disabling disease most often affecting the shoulder region. The main problem is instability of the scapula during attempted shoulder elevation and abduction. Scapulothoracic arthrodesis has been suggested as an effective solution for this problem and one approach is use of multifilament fixation [1
]. To assess this approach, we therefore determined (1) fusion rates, (2) changes in active ROM, (3) functional outcome scores, (4) respiratory capacity, and (5) complications. We also evaluated correlation between functional scores.
The major shortcoming of the study is the lack of a control group. However, establishing a control group is difficult for two reasons. First, observing a control group of patients without treatment of such a functionally disabling disorder would be ethically unacceptable. Second, because FSHD is a rare disorder, performing another type of operation to compare the results either would take a long time or diminish the size of an already small group of patients. In addition, a minimum of 2 years followup is relatively short for a progressive neuromuscular disease. The need for validation of the new SFS is another weakness of the study. However, we observed a correlation with the DASH score. Therefore, the score may be used for evaluation of patients with FSHD after validation in larger series.
Our data suggest scapulothoracic arthrodesis using multifilament cables reduced scapular winging and improved function of the shoulder muscles in patients with FSHD. The substantial improvements in clinical parameters in our patients were in accordance with those in previous series (Table ) [1
]. A similar improvement in active shoulder abduction was observed in our patients, whereas the increase in mean forward flexion (73°) was relatively higher compared with values in other series.
Comparison of published series
The decrease in DASH scores (from 34 points to 12 points) indicated patients’ satisfaction. In some other series [1
], ROM and improvement in daily activities without numeric values such as the DASH score were used. A special scoring system for patients with FSHD with scapulothoracic fusion was introduced previously [5
], however that scoring system is less detailed than the SFS.
In addition to the subjective DASH score, clinical results were evaluated using an objective evaluation system. Similar to the DASH score, we observed improvements with this new SFS score. The presence of a strong correlation between DASH and SFS scores led us to assume this new score might be a useful tool for researchers. Special importance is given to shoulder flexion and abduction strengths in this scoring schema, which are affected mainly by the anterior and midportions of the deltoid muscle. Because the deltoid either is spared or affected in late stages of the disorder, severity of deltoid muscle involvement is used as a prognostic parameter. Subjective criteria such as fatigue or pain were not included in the parameters, thus increasing the reproducibility of the score.
After achieving scapulothoracic fusion, the functional capacity of the patient will be affected only by severity of the progression of FSHD. We have not observed any deterioration in the functional results and ROM after an average of 3 years followup. We will continue followup of the patients and evaluate long-term results. Because fusion was achieved in all patients, we do not expect future problems resulting from the fusion. However, FSHD is a progressive disease and if the deltoid and/or trapezius involvement worsens, shoulder functions of patients also might worsen.
Fusing the scapulothoracic articulation is a relatively difficult task compared with most other arthrodesis sites, because both sides of the fusion consist of thin and fragile bones. In some series, revisions for nonunions were reported at 3% to 6% [1
]. The nonunion rate in our series (two of 18 shoulders) may be related to patients who started vigorous activities early during the recommended immobilization period. Both patients with nonunion had successful revision and achieved the same functional levels as the other patients. Some criteria should be considered during selection of a technique for scapulothoracic arthrodesis: (1) fixation strength should provide secure stabilization between the scapula and thorax during the healing period; (2) the complication rate should be low; and (3) routine removal of the implants should not be required. Owing to difficulties in screw fixation of thin bones and the close proximity of the pleura, wire fixation was the preferred method by some authors [12
]. Wires were augmented with plates on the scapular side by others [9
]. The cables we used avoided the need for an augmenting implant such as a plate, as the beads of the cables provided a wide surface contact area, creating a buttress effect, similar to a plate or washers used by other authors [1
]. Loosening and stretching were minimized and stable fixation was achieved. We did not believe it was necessary to use an augmenting implant to protect the medial scapular margin. We recommend shoulder immobilization in the sling for at least 3 months.
Selecting the number of ribs involved in the fusion is controversial [9
]. We fused five consecutive ribs, providing adequate stability in 15 of 18 shoulders. We believe five-level fusion is a practical upper limit for scapulothoracic arthrodesis, because the flat scapula cannot be approximated to the convex thorax at both ends.
Verification of a solid fusion at the arthrodesis site is difficult with clinical examination and direct radiographs. The CT examination with 3-D reconstruction was valuable for this purpose. Therefore we evaluated most patients with 3-D CT.
The scapulothoracic region is prone to perioperative complications. Intraoperative and postoperative complications such as pneumothorax, hemothorax, rib fracture, and scapular fracture have been reported [2
]. In a series of 47 patients operated on using plate-screws and wires, fracture of the scapula and ribs during screw insertion occurred in one patient, bilateral stress fractures of the scapula occurred in one patient 2 years after the operation, and two rib fractures occurred in one patient during followup [9
]. In a series of four shoulders, fused using 16-gauge Luque wires, no complications were observed [12
]. In another study, the authors stabilized the scapula to six consecutive ribs (ribs 2–7) in 12 shoulders using 18-gauge wires and reported one symptomatic nonunion (8.3%) [20
]. Another report revealed a brachial plexus palsy that resolved spontaneously in one patient and there were no complications related to the wire fixation technique, such as rib or scapula fracture or implant failure [2
]. In our series, there were three complications, of which two (11.1%) had revision arthrodesis.
One possible consequence of scapulothoracic arthrodesis is limitation in expansion of the thoracic cage, resulting in reduced pulmonary capacity. Twyman et al. [20
] reported a 21% decrease in the forced vital capacity and a 14% decrease in the forced expiratory volume postoperatively. Others reported they observed no change in pulmonary functions [1
]. We observed no changes in the pulmonary reserve after one-sided scapulothoracic arthrodesis.
A successful scapulothoracic arthrodesis provides satisfactory clinical function in patients with FSHD. Use of multifilament cables for fixation is a reasonable option with a low complication rate.