 CHILDREN’S ORTHOPAEDICS

Surgical correction of shoulder rotation deformity in brachial plexus birth palsy LONG-TERM RESULTS IN 118 PATIENTS T. Hultgren, K. Jönsson, F. Roos, H. Järnbert-Pettersson, H. Hammarberg From Karolinska Institute, Stockholm, Sweden

 T. Hultgren, PhD, MD, Consultant Hand Surgeon  K. Jönsson, MD, Research Assistant  F. Roos, MD, Consultant Hand Surgeon  H. Hammarberg, MD, PhD, Consultant Hand Surgeon Karolinska Institute, Department of Clinical Science and Education, Section for Hand Surgery, Södersjukhuset S-118 83 Stockholm, Sweden.  H. Järnbert-Pettersson, PhD, Statistician Karolinska Institute, Department of Clinical Science and Education, Södersjukhuset S-118 83 Stockholm, Sweden. Correspondence should be sent to Mr T. Hultgren; e-mail: tomas.hultgren@ sodersjukhuset.se ©2014 The British Editorial Society of Bone & Joint Surgery doi10.1302/0301-620X.96B10. 33813 $2.00 Bone Joint J 2014;96-B:1411–18. Received 15 January 2014; Accepted after revision 4 July 2014

We present the long-term results of open surgery for internal shoulder rotational deformity in brachial plexus birth palsy (BPBP). From 1997 to 2005, 207 patients (107 females, 100 males, mean age 6.2 (0.6 to 34)) were operated on with subscapularis elongation and/or latissimus dorsi to infraspinatus transfer. Incongruent shoulder joints were relocated. The early results of these patients has been reported previously. We analysed 118 (64 females, 54 males, mean age 15.1 (7.6 to 34)) of the original patient cohort at a mean of 10.4 years (7.0 to 15.1) post-operatively. A third of patients with relocated joints had undergone secondary internal rotational osteotomy of the humerus. A mixed effects models approach was used to evaluate the effects of surgery on shoulder rotation, abduction, and the Mallet score. Independent factors were time (pre-and postsurgery), gender, age, joint category (congruent, relocated, relocated plus osteotomy) and whether or not a transfer had been performed. Data from a previously published short-term evaluation were reworked in order to obtain pre-operative values. The mean improvement in external rotation from pre-surgery to the long-term follow-up was 66.5° (95% confidence interval (CI) 61.5 to 71.6). The internal rotation had decreased by a mean of 22.6° (95% CI -18.7 to -26.5). The mean improvement in the three-grade aggregate Mallet score was 3.1 (95% CI 2.7 to 3.4), from 8.7 (95% CI 8.4 to 9.0) to 11.8 (11.5 to 12.1). Our results show that open subscapularis elongation achieves good long-term results for patients with BPBP and an internal rotation contracture, providing lasting joint congruency and resolution of the trumpet sign, but with a moderate mean loss of internal rotation. Cite this article: Bone Joint J 2014;96-B:1411–18

Brachial plexus birth palsy (BPBP) frequently results in an internal rotation deformity of the shoulder despite an otherwise good neurological recovery.1-3 The internally rotated position of the limb is cosmetically and functionally disturbing.4,5 To bring the hand to the face the shoulder is abducted, elevating the elbow; the so-called trumpet sign,6 and patients may have difficulty with activities of daily living. A number of surgical procedures have been suggested and evaluated,1,7-11 but there are few large studies that have analysed the long-term results of surgery.12-14 In a previous publication, we examined the results for a series of 270 patients with BPBP and shoulder deformity at one year following open surgery.3 In this study we revisit the same series seven years or more after the primary operation, considering longterm functional outcome and re-operation rate. Our interest was whether the surgery continued to provide improved limb mobility over an extended period of time. In addition, we wanted to know if the long-term mobility was

VOL. 96-B, No. 10, OCTOBER 2014

affected by the addition of a latissimus dorsi transfer, the relocated joints remained congruent, how many of the patients with relocated joints required additional surgery and how their mobility compared with the other groups. Finally, we wondered if a reduction of internal rotation in the shoulder affected limb function.

Patients and Methods From 1997 to 2009, operations were performed on a consecutive series of 274 patients with unilateral BPBP and an internally rotated shoulder deformity. Open subscapularis elongations and latissimus dorsi to infraspinatus transfers were performed either separately or in combination. Concomitant relocation of an incongruent joint was possible in 97 of 105 (92.4%) of the patients. The indications for surgery, choice of operating procedures and surgical techniques have been described in detail in our previous publication.3 The inclusion criterion for the present study was a minimum follow-up time of seven years 1411

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T. HULTGREN, K. JÖNSSON, F. ROOS, H. JÄRNBERT-PETTERSSON, H. HAMMARBERG

Operated on (274) Lost to follow-up (4) Follow-up at one year (270) Less than seven years post-op (63) Eligible for long-term follow-up (207) Could not come (15) Did not respond (74) Follow-up at > seven years (118) Fig. 1 Flowchart of patient inclusion.

after the initial operation. Ethical approval was granted for the study by the Regional Ethics Committee in Stockholm. Eligible patients were contacted with written information and invited to take part in the study: from a potential cohort of 207 patients, 118 consented to the assessment (Fig. 1). The mean follow-up time was 10.2 years (7.0 to 15.1). The mean age at follow-up was 15.1 years (7.6 to 33.7) and there were 64 females and 54 males. The nerve injury was classified as C5–C6 or C5–C7 in 116 of the examined patients, the inferior trunk was also involved in the remaining two patients. A total of six of the upper trunk group had undergone nerve reconstruction and one of the two patients with lower trunk involvement had the nerve injury reconstructed. Shoulder joint relocation had been achieved in 63 of 66 patients with incongruent joints. There were three failed relocations, which were left subluxed; the remaining 52 joints were congruent. Since the one year follow-up, 23 of the 63 had also required an internally rotating osteotomy of the proximal humerus. The indication for the osteotomy in 18 patients was an active internal rotation of < 30°, causing difficulties in their daily activities. In the other five patients, recurrent intermittent subluxation of the humeral head had started between three and six years after the index operation. The subluxation would occur in extreme internal rotation, sometimes during sleep. A total of three of these five patients also had a posterior stabilisation procedure according to Hawkins and Janda.15 All five joints were stable at the long-term follow-up. We have not seen any other patients in the series with late re-subluxation. Six patients with relocated joints had < 30° of active internal rotation but were not troubled by the restriction and did not desire an osteotomy. Latissimus dorsi transfer was an isolated procedure for an initial eight patients with full passive mobility. Five of these patients subsequently developed a rotational

contracture necessitating a second operation with subscapularis elongation. All eight patients remain in their original subgroup (‘transfer only’) in the statistical analysis. Shoulder mobility (thoraco-humeral movement) and Mallet scores6 were measured pre- and post-operatively, as described in our previous publication.3 We used the modified three-grade Mallet score as described by Birch,16 where each of the five specified movements are graded from 1 to 3, giving an aggregate score of from 5 to 15. The examinations were performed by three surgeons who had not been involved in the primary surgery, two of whom are coauthors (KJ and FR). In order to assess functional impairment due to a limitation of the internal shoulder rotation, the participants were requested to grade their ability to perform three activities: to button and unbutton their shirt or blouse, to put their hand in their trouser pocket, and to wash the opposite axilla without the aid of the good hand. Each activity was given three grades: easy, difficult or impossible. The grades were then compared with the values for internal rotation in order to determine if there was a correlation between the range of internal rotation and impairment of the specified function. Wrist flexion was also analysed as it assists many activities involving internal rotation of the shoulder. Statistical analysis To study any inclusion bias between the re-examined and unexamined groups, we compared their shoulder function at one-year post-surgery, using the independent samples t-test for external rotation, internal rotation and abduction and the Mann-Whitney U test for the Mallet scores. A mixed-effects model approach was used to evaluate the effect of surgery on shoulder function over time, to allow correlation of repeated observations on the same individual. Furthermore, mixed-effects models are able to accommodate missing data and integrate time-varying factors, which are issues in the present study.17 The pre-operative and one-year post-operative values presented all refer to the larger groups of patients examined at those time points.3 The outcome factors studied were external and internal shoulder rotation, shoulder abduction, aggregate and separate movement Mallet scores. Independent factors were: the time points (pre-surgery, post-surgery at one year and at ≥ seven years), gender, age at operation, shoulder joint congruency and whether or not a latissimus dorsi transfer had been performed. The model strategy used to evaluate the effect of surgery has been described before.3 In brief, we first studied unadjusted associations for each independent factor. Two-way interactions between the time point and each of the other four independent factors were tested. If the interaction was significant (p < 0.05), we created a new factor consisting of the combinations of the levels from the original factors. Adjusted associations were then calculated by including all THE BONE & JOINT JOURNAL

SURGICAL CORRECTION OF SHOULDER ROTATION DEFORMITY IN BRACHIAL PLEXUS BIRTH PALSY

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Table I. Mixed-effect model regression analysis of factors associated with active external rotation (°). Estimated means (95% confidence interval) and p-values given for comparison with the reference level (i.e. first factor level). Values have been calculated for the larger groups that were examined pre-operatively (262) and at one year post-operatively (263), and for the smaller group of 118 which was available at seven years post-operatively (64 females, 54 males)) Factor

Factor level

Patients (%)

Unadjusted

Adjusted 1

Adjusted 2

Adjusted 3

* Interaction time age

Pre-operative, < 2 years

51 (18.9)

Reference

Reference

Reference

Reference

Time point

Pre-operative

270

Reference

Gender

Age group

Joint category

Transfer procedure

Interaction time* joint

Interaction time*transfer

Post-operative one yr

270

83.8 (79.3 to, 88.3) p < 0.001

Post-operative ≥ 7 yrs

118

66.5 (61.5 to 71.6) p < 0.001

Female

142 (52.6)

Reference

Reference

Reference

Reference

Male

128 (47.4)

-2.6 (-9.7 to 4.6) p = 0.48

-2.0 (-5.8 to 1.9), 0.32

-1.9 (-5.8 to 2.0) p = 0.33

-1.9 (-5.7 to 2.0) p = 0.34 Reference

< 2 yrs

51 (18.9)

Reference

Reference

2 to 19 yrs

215 (79.6)

5.7 (-3.2 to 14.7), 0.21

5.2 (-3.6 to 10.7), 0.67

5.6 (0.1 to 11.0) p = 0.046

≥ 20 yrs

4 (1.5)

-26.2 (-59.6 to -7.2) p = 0.12

-26.3 (-44.1 to -8.5) p = 0.004

-25.7 (-43.5 to -7.9) p = 0.005

Congruent

165 (61.1)

Reference

Reference

Relocated no osteotomy

82 (30.4)

-8.0 (-16.0 to 0.0) p = 0.045

-10.8 (-15.4 to -6.2) p < 0.001

-10.3 (-14.8 to -5.7) p < 0.001

Relocated plus osteotomy

23 (8.5)

-4.3 (-16.1 to 7.4) p = 0.47

-11.3 (-18.4 to -4.1) p = 0.02

-11.2 (-18.3 to -4.1) p = 0.002

Elongation only

177 (65.6)

Reference

Reference

Reference

Elongation plus transfer

76 (28.1)

-4.9 (-13.1 to 3.2) p = 0.24

-7.4 (-11.9 to -2.8) p = 0.02

-7.4 (-12.0 to -2.8) p = 0.02

Transfer only

17 (6.3)

-6.3 (-21.1 to 8.5) p = 0.41

-12.3 (-20.4 to -4.2) p = 0.03

-12.3 (-20.5 to -4.2) p = 0.03

2 to 19 yrs

215 (79.6)

23.0 (14.8 to 31.1) p < 0.001

≥ 20 yrs

4 (1.5)

9.6 (-16.4, 35.6) p = 0.47

Post-operative one yr, < 2 yrs

51 (18.9)

115.3 (105.9 to 124.7) p < 0.001

2 to 19 yrs

215 (79.6)

100.1 (92.0 to 108.1) p < 0.001

20 yrs

4 (1.5)

53.3 (29.2 to 77.5) p < 0.001

Post-operative ≥ 7 yrs, < 2 yrs

29 (10.7)

81.2 (70.3 to 92.0), p < 0.001

2 to 19 yrs

89 (33.0)

88.1 (79.7 to 96.6) p < 0.001

≥ 20 yrs

0 Reference

Reference

Reference

Pre-operative, congruent

165 (61.1)

Relocated no osteotomy

82 (30.4)

-25.7 (-32.7 to -18.8) p < 0.001

Reference

Relocated plus osteotomy

23 (8.5)

-23.9 (-35.2 to -12.7) p < 0.001

Post-operative one yr, congruent

165 (61.1)

72.8 (67.5 to 78.2) p < 0.001

Relocated no osteotomy

82 (30.4)

73.6 (67.0 to 80.3) p < 0.001

Relocated plus osteotomy

23 (8.5)

82.9 (72.3 to 93.6) p < 0.001

Post-op ≥ 7 yrs, congruent

55 (20.4)

60.2 (53.4 to 67.0) p < 0.001

Relocated no osteotomy

40 (14.8)

59.5 (51.9 to 67.0) p < 0.001

Relocated plus osteotomy

23 (8.5)

45.0 (35.0 to 55.0) p < 0.001

Pre-operative, elongation only 177 (65.6) Elongation plus transfer

Reference

Reference

Reference

Reference

Reference

76 (28.1)

-8.3 (-15.5 to -1.0) p = 0.025 -8.0 (-21.3 to -5.2), 0.23

Transfer only

17 (6.3)

Post-operative one year, elongation only

177 (65.6)

85.2 (79.6 to 90.7) p < 0.001

Elongation plus transfer

76 (28.1)

75.1 (68.2 to 82.0) p< 0.001

Transfer only

17 (6.3)

63.7 (51.3 to 76.2) p