Humeral Fracture

Fracture/trauma is the next most common problem addressed by shoulder replacement. Snyder reports the rate as 9% (1996), Torchia and associates as 12% (1997), Neer and colleagues as 23% (1982), Sojbjerg and colleagues as 30% (1999), and Rahme and associates as 35% (2001). In fact, repair of the humerus after fracture was the driving reason for the development of the first modem shoulder replacement component (Neer, II 2003) and the first reported series of modern shoulder replacements were done to correct problems caused by humeral fractures (Neer, II1974). 

The modern era of shoulder replacement was ushered in by Dr. Charles Neer, II. In 1953, in response to the relatively poor results of humeral head resection for patients with proximal humeral fractures. Dr. Neer implanted a vital-hum humeral component of his own design in a hemiarthroplasty procedure (Figure 9.4). In 1955, he reported on his first series of 12 pahents treated in this way. 

Malunion of humeral fractures has greater significance the further the fracture is from the shoulder. 

Injuries to the shoulder are reported to account for about for 8%-16% of fractures in children. Falls onto the shoulder are the usual cause of fractures of the clavicle, whilst falls onto the outstretched hand cause proximal humeral fractures. Whilst the mechanisms of injury to the shoulder in children are similar to those in adults, the fracture patterns seen differ as a consequence of the presence of the physes, with physeal separation occurring in preference to dislocation. 

Fig. 17.7a,b. This 12-year-old presented with a completely displaced proximal humeral fracture (a). It was treated conservatively. By 4 months extensive remodelling is present and shoulder function was normal (b)... 

Supracondylar humeral fractures are the commonest fractures in children under the age of 7. Complications are common, with rates of nerve injury reported between 6% and 16% (Lyons et al. 2000), and a high... 

Levy J, et al. The use of the reverse shoulder prosthesis for the treatment of failed hemiarthroplasty for proximal humeral fracture. J Bone Joint Surg Am 2007 89(2) 292-300. 

Palvaxen M, et al. Update in the epidemiology of proximal humeral fractures. Clin Orthop Relat Res 2006 442 87-92. 

Muscle weakness, steroid myopathy, loss of muscle mass, severe arthralgia, vertebral compression fractures, aseptic necrosis of humeral and femoral heads, pathologic fracture of long bones, osteoporosis... 

A 56-year-old 70 kg woman with a Colles fracture received a brachial plexus block at the humeral canal with 0.75% ropivacaine 40 ml using a nerve stimulator (11). The local anesthetic was administered slowly with negative intermittent aspiration. However, 15 minutes later she had two generalized convulsions, which were treated with diazepam. The total venous ropivacaine concentration measured 2 hours after the block was 2.3 gg/ml. 

Integrated . A collection of monoblock and modular cobalt chromium humeral prostheses within a single system. Included are the Kirschner n-C monoblock, and the Atlas modular design. Glenoid components include all-poly UHMWPE keeled and pegged components as well as a metal-backed, screw-fixed design. Components of the system are intended for primary, hemiarthroplasty, total, and fracture use with cemented and press-fit fixation. 

Select . Modular titanium stem humeral prostheses with keeled and pegged UHMWPE glenoid components sterilized by gamma in an oxygen-free environment. Developed with Dr. Wayne Burkhead, it was introduced in 1987. It is intended for primary, hemiarthroplasty, total, and fracture use with cemented fixation. 

GlobaF and GlobaF Advantage and GlobaF FX. Modular cobalt chromium humeral prostheses developed with Drs. Charles Rockwood and Fredrick Matsen, III, and first introduced in 1990. They include UHMWPE keeled and five-pegged glenoid components sterilized by gas plasma. They are intended for primary, hemiarthroplasty, total, and fracture use (FX specifically) with press-fit fixation. 

Foundation and Foundation fracture. Modular titanium stem humeral prostheses with keeled and pegged UHMWPE glenoid components sterilized... 

Modular Shoulder System. A modular titanium stem humeral component with a keeled UHMWPE glenoid component sterilized by EtO. Cobalt chromium, titanium nitrite, and ceramic humeral heads are available as part of the system. It is intended for primary, hemiarfhroplasty, total, and fracture use with press-fit fixation. 

Aequalis and Aequalis Fracture contemporary shoulder prosthesis system components. The noncemented humeral component is shown in (A). An underside view of an indexing offset head, and the proximal stem angle adaptors are shown in (B). An Aequalis fracture prosthesis in a fracture jig to aid in component positioning and reconstruction of the proximal humerus is shown in (C) (images courtesy of Tornier, Stafford, TX). 

The proximal humeral epiphysis arises from two, sometimes three separate ossification centres (Fig. 7.12). The first ossification centre develops medially at about 2 weeks of age and the second ossification centre develops in the greater tuberosity between 6-12 months of age. When the arm is internally rotated, the first appearing medial ossification centre is rotated into a lateral position and can give the false impression of shoulder joint disruption. The rare third centre occurs in the lesser tuberosity in the third year of life, and when visualised on the axillary shoulder view, may be mistaken for a fracture. This ossification centre fuses with the shaft of the humerus at 6-7 years of age. The radiolucent proximal physis of the humerus is tented and in various oblique positions can be mistaken for a fracture (Fig. 7.13). The normal bicipital groove in the proximal humerus may simulate periosteal new bone formation (Fig. 7.14). 

Fig. 7.13a,b. AP (a) and axial (b) views of the proximal humerus showing the normal lucent proximal humeral epiphysis, sometimes mistaken for a fracture (arrows)... 

The radiological interpretation of humeral shaft fractures is usually uncomplicated in comparison to shoulder and elbow injuries. Fractures of the humeral shaft only account for approximately 25% of total injuries to the bone. 

The standard treatment for humeral shaft fractures is non-operative. Gravity can be utilised both to splint the fracture and maintain it in a satisfactory position. A heavy hanging cast applied from just below the shoulder to the hand will apply traction to the injured limb. The muscles of the anterior and posterior compartments of the arm will be stretched and this will align and splint the limb (Fig. 9.12). 

The radial nerve is closely applied to the humeral shaft in its middle and distal thirds. If, following manipulation of mid to lower third displaced fractures, a radial nerve palsy develops in association with soft tissue interposition on radiographs, sur-... 

Fractures of the proximal radius and ulna are most commonly identified in association with distal humeral injuries, and are the result of hyperextension. Mid forearm fractures are typically transverse and the result of either a direct blow or levering force. Forearm fractures in a toddler, though not an infant, may occur as when an arm is raised to protect the face and head. Distal forearm fractures are indistinguishable from those seen as typical accidents in older children who fall on the outstretched arm. The history and mode of presentation are important factors in differentiating abuse from accident. 

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