We thank Dr. Price and colleagues for their interest and the opportunity to further clarify our approach to the internal rotation contractures that develop in so many of these children. It was our frustration with methods similar to those he describes that led us to explore and develop the arthroscopic approach. Approximately 70% of children that present with internal rotation contractures will have glenohumeral deformity(1, 2). The children with centered glenohumeral joints that the correspondents allude to represent a minority. For the majority with advanced contractures and deformity, there is increasing evidence that the described surgical method does not consistently relocate the glenohumeral joint and may impede optimal skeletal development.

Birch and van der Sluijs, have independently reported on yet another method of releasing the subscapularis, one that releases it from its insertion aiming for a step lengthening of the tendon while preserving the anterior capsule (when possible)(3, 4). Both of these authors reported that in severe contractures it is not possible to achieve reduction of the glenohumeral joint without releasing the anterior capsule, (15 out of 19 of van der Sluijs’ series). In addition, Dr. Birch postulates that in many instances, excessive retroversion compels an external rotation contracture once the glenohumeral joint is reduced. For retroversion greater than 40°, he recommends an internal rotational osteotomy as part of the same procedure (70 out of his 183 reported cases)(4). Another recent study by Bae and Waters demonstrated that procedures that avoid the anterior capsule fail to result in glenohumeral remodeling(5), further establishing that extra-articular procedures are incompletely effective in such cases. So the question becomes, for children with severe contractures and/or those with advanced glenohumeral deformity, do surgeons that do not address the subscapularis tendon and the underlying joint capsule consistently achieve a complete release that will allow glenohumeral remodeling? The foregoing studies and our own suggest not.

It is not clear why the correspondents compare attempted arthroscopic release of an extra-articular structure such as the Achilles tendon to our procedure, but contrary to his intention, this comparison does highlight the appeal of minimizing surgical trauma with percutaneous and arthroscopic approaches. The comparison also brings to light the reality that most caretakers of these children have considerable expertise in areas other than shoulder surgery (neurosurgery, plastic surgery, hand and pediatric orthopaedics). Only surgeons experienced in shoulder arthroscopy should consider this form of management. Our program, and others that have adopted the arthroscopic approach, combine the efforts of a hand/peripheral nerve surgeon and shoulder specialist to address the complexity of many of these problems.

As discussed in our paper, the existing literature is woefully inadequate in describing the loss of internal rotation that comes from any method of treatment and we need better methods to quantify and document this concern. This is certainly true of the clinical results published by the correspondents and all other clinical series that employ similar methodology. It is somewhat ironic that our attempt to deal with this issue candidly has become a point of vulnerability in a field that has, until recently, skirted the issue. It is a mistake to think that children who receive a release of the subscapularis from its origin have normal subscapularis function. The truncated and atrophied subscapularis muscle can be seen on MRI and corresponds to a limitation of active internal rotation on clinical examination. In fact, loss of internal rotation in some of our earlier open cases exceeded that seen in many of our arthroscopic cases. Yes, it is true that we would opt for improved internal rotation in nearly all of our patients. The state of the art, however, does not, at present, offer these children a perfect solution that provides for a complete range of motion in all directions with normal glenohumeral development. We concur with Dr. Birch et al. that a contemporary surgical approach must achieve glenohumeral reduction for children with skeletal remodeling potential, and then restore the functional orientation of the arm if needed. This can be done by open or arthroscopic means, in one or more operations.

References:

1. Pearl, M.L. and B.W. Edgerton, Glenoid deformity secondary to brachial plexus birth palsy. J Bone Joint Surg Am, 1998. 80(5): p. 659-67.

2. Pearl, M.L., et al., Comparison of arthroscopic findings with magnetic resonance imaging and arthrography in children with glenohumeral deformities secondary to brachial plexus birth palsy. J Bone Joint Surg Am, 2003. 85-A(5): p. 890-8.

3. van der Sluijs, J.A., et al., Treatment of internal rotation contracture of the shoulder in obstetric brachial plexus lesions by subscapular tendon lengthening and open reduction: early results and complications. J Pediatr Orthop B, 2004. 13(3): p. 218-24.

4. Kambhampati, S.B., et al., Posterior subluxation and dislocation of the shoulder in obstetric brachial plexus palsy. J Bone Joint Surg Br, 2006. 88(2): p. 213-9.

5. Waters, P.M. and D.S. Bae, Effect of tendon transfers and extra- articular soft-tissue balancing on glenohumeral development in brachial plexus birth palsy. J Bone Joint Surg Am, 2005. 87-A(2): p. 320-5.

To The Editor:

We congratulate the authors for demonstrating the potential for glenohumeral remodeling in children with brachial plexus birth injuries. We appreciate their attempts to clarify the surgical indications for tendon transfer versus release of the internal rotation contracture. However, we take issue with their belief that arthroscopic release adds anything and believe it may, in fact, be somewhat inadequate. The authors state that “releasing the subscapularis from its origin failed in one in five children.” The authors do not clarify whether those failures were in patients with posterior dislocation/subluxation or in patients in whom the humeral head was centered. When the glenohumeral joint is centered, we have never encountered such failures. In children with longstanding subluxation or dislocation, we have taken an individualized approach. After our subscapular slide, we release tight structures anteriorly, including intramuscular lengthening of the pectoralis, partial release of the coracobrachialis tendon, partial coracoidectomy, and/or release of the coracohumeral ligament. Using this approach, we have never failed to achieve equivalent full external rotation of the affected shoulder. We do not immobilize the patients in full external rotation postoperatively for fear of overstretching these structures and causing too much weakness and loss of internal rotation power. We wonder whether the authors are immobilizing their patients postoperatively in too much external rotation.

Finally, we see no logic in doing releases through the arthroscope. One would not release a heel cord contracture with ankle arthroscopy. In addition to risk to the axillary nerve (their patient lost 40 degrees of elevation), four of their patients “had severe functional loss of external rotation and thus prompted consideration of additional intervention such as internal rotation osteotomy.” Alain Gilbert has abandoned anterior release at the insertion of the subscapularis for this very reason (1). We believe anterior tenotomy of the subscapularis renders too much functional loss of internal rotation.

Because 5 of 33 patients (15%) had a serious complication, we feel this approach must be reconsidered.

The author(s) of this letter to the editor did not receive payment or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author(s) are affiliated or associated.

Reference:

1. Gilbert A. Personal communication. February 2003 at the Seventh Workshop on Obstetric Brachial Plexus Lesions, Heerlen, THE NETHERLANDS.