Successful reverse total shoulder replacement in a patient with Apert syndrome

Introduction

Apert syndrome, first described in the literature by a French pediatrician Eugene Apert, is a rare congenital form of acrocephalodactyly with autosomal dominant inheritance. ¹ Classically, this syndrome is characterized by craniosynostosis, midface hypoplasia, and symmetrical syndactyly of hands and feet resulting from embryonic anomalies during the third week of gestation. It is also associated with a variety of abnormalities of the viscera, involving the neurological, genitourinary, and cardiorespiratory systems. ²

Glenohumeral manifestations of Apert syndrome include glenoid dysplasia, an oblong humeral head with a prominence of the greater tuberosity, acromial prominence, and inferior subluxation of the glenohumeral joint.^3–5 This pathological anatomy results in progressive degenerative changes, synchondrosis, and restriction in shoulder joint mobility, particularly in flexion and abduction. ⁶ While surgical options for the accompanying deformities of the feet and spine are described, interventions for shoulder pathology are not well defined.^4,6,7 Joint replacement surgery could offer such patients pain relief and improved function.^8,9 Reverse total shoulder arthroplasty is yet to be described in Apert syndrome and this case report presents the outcome in a 48-year-old male.

Case report

A 48-year-old air-conditioning electrician presented with severe pain and stiffness in his right shoulder. He reported many years of progressive symptoms, affecting his activities of daily living and increasingly limiting his job performance. The patient was diagnosed with Apert syndrome at birth and had a history of multiple surgeries for craniofacial, hand, and foot deformity correction associated with Apert syndrome, but was otherwise healthy.

Examination revealed global shoulder tenderness. The movement was mainly scapulothoracic, with 80 degrees forward flexion, 80 degrees abduction, external rotation in adduction to 30 degrees, and internal rotation to the level of the sacrum, with pain in all directions. Deltoid contraction and control were present. The patient was neurovascularly intact.

Radiographs (Figure 1(a)–(c)) demonstrated a dysplastic glenohumeral joint with severe degenerative changes, pathognomonic anteversion of the glenoid with far medial subluxation of the humerus and an abnormal, deformed “oblong” humeral head. Computed tomography (CT) scan confirmed the complex glenoid dysplasia, with humeral head subluxation medial to the coracoid, in close proximity to the neurovascular structures, coracoid thinning and neoarticulation with the humerus (Figure 2(a)–(c)). Significant osteophyte formation, subchondral sclerosis, and cysts were noted, as well as multiple loose bodies.

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Figure 1.

(a) Grashey anteroposterior view of the right shoulder, demonstrating dysplasia of the joint with classical medialization of joint and subcoracoid neoarticulation. (b) Neer view of the right shoulder, dysplasia. (c) Internal rotation view of right shoulder, dysplasia with locked movement.

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Figure 2.

(a) Parasagittal CT right shoulder. (b) Paraaxial CT right shoulder. (c) 3D reconstruction of the right shoulder.

The patient was initially managed non-operatively. Analgesia options were limited by adverse reactions to opioid medications. A trial of two corticosteroid injections resulted in no relief of pain or improvement in function. A suprascapular nerve block provided only temporary relief in pain before symptoms returned. After two years of severe, worsening shoulder pain refractory to non-operative treatment, a joint decision was made to pursue operative management. The primary goals of surgery were to alleviate pain and improve range of movement. He underwent a Zimmer Biomet Comprehensive reverse total shoulder replacement, with an uncemented baseplate and stem (Figure 3(a) and (b)). The deltopectoral approach was challenging, requiring careful preparation deep and medial to the conjoint tendon for adequate visualization. A thin intact subscapularis was peeled off. In situ humeral osteotomy was necessary, due to the degenerative hyper-congruence and extreme rigidity of the glenohumeral joint. Adequate baseplate positioning and screw fixation in the glenoid vault was achieved. Care was taken not to overtighten the chronically contracted joint. Intraoperative stability testing confirmed no impingement and a good range of motion.

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Figure 3.

(a) Grashey anteroposterior view of the right shoulder, post-operative well-centered reverse total shoulder replacement. (b) Neer view of the right shoulder, well-centered reverse total shoulder replacement.

Post-operative recovery was routine and uneventful, with hospital discharge at three days post-operatively. At a 6-week follow-up, the patient's resting and movement pain had significantly improved. At the 2-year follow-up, the range of motion and function was superior to pre-operative. At a 2-year follow-up, the range of motion was 90 degrees forward flexion, and 90 degrees abduction, with the same degree of external and internal rotation as pre-operative. At the 2-year follow-up, his recorded constant score was 62 out of 100, his ASES score was 92 out of 100, and his DASH score was 5 out of 100. No clinical or radiological complications were noted and both patient and surgeon were satisfied.

Discussion

To our knowledge, this is the first reported implantation of a reverse total shoulder replacement to address glenoid dysplasia in a patient with Apert syndrome. Treatment of the congenital dysplastic glenoid is challenging. Humeral head resurfacing is reported to offer short-term pain relief and function, with variable patient satisfaction. ¹⁰ Long-term results are scarce with the largest case series including only 20 patients. Allen et al. ¹¹ reported outcomes at a mean of 6 years with a high rate of complication including progression of pain, component loosening, and revision surgery. Treatment of anteromedial dysplastic glenoid morphology may have similar complications when anatomical resurfacing total joint constructs are used.^11,12 Sheth et al. ¹³ compared total shoulder arthroplasty and hemiarthroplasty at 2 years on dysplastic glenoids and reported equal outcomes. However, the dysplastic groups they reported were of Walch C-type glenoid morphology, rather than the typical complex dysplasia of Apert syndrome. ¹³ In Apert's syndrome, total shoulder replacement or hemiarthroplasty could be considered, but pre-existing anteromedial subluxation of the dysplastic glenohumeral joint would likely result in progressive glenoid erosion. The adaptability of a reverse humeral baseplate, with or without metal augments, offers more reliable fixation at the glenoid implant interface and the higher degree of implant constraint could provide joint stability and symptomatic relief. ¹⁴

Our case suggests that despite early developmental synchondrosis of the glenohumeral joint, reverse total shoulder replacement may be a viable surgical treatment that provides excellent pain relief and improvement of function in the presence of adequate deltoid muscle function.

Conclusion

The literature guiding the treatment of shoulder pathology in Apert syndrome is scarce. Reverse total shoulder replacement may be a viable surgical treatment option in older patients who have failed non-operative treatment. As with all reverse total shoulder replacements, an innervated and functioning deltoid muscle is mandatory. Surgery is technically challenging due to grossly abnormal glenoid and humeral head positioning, and pre-operative 3D planning is recommended with the surgeon to consider the use of patient-specific instrumentation.