The classification and treatment of heterotopic ossification about the elbow and forearm

Successful treatment of HO about the forearm and elbow relies on a working understanding of the risk factors, the pathophysiology and pathoanatomy, and the potential role for reconstructive procedures. These elements must be combined with a certain degree of flexibility in the approach to patients with a wide range of individual needs. Class I HO should be managed primarily with close observation, serial radiographs, and appropriate physical therapy regimens. The temporal relationship between the insult and the appearance of HO may modify the approach. When HO is noted within the first 6 weeks, use of anti-inflammatory agents is recommended; if the patient has developed limiting ectopic bone in the past, consideration should be given to a single dose of radiotherapy. In the 6-week to 3-month period, therapy is conducted to maintain full motion and an anti-inflammatory agent continued or started. We have not observed initial HO appearance after the third month. Class IIA HO can involve the anterior or posterior aspects of the elbow joint, or both. These groups are further divided into those limited by soft tissue (muscle and capsular contracture) and those blocked by bone (coronoid extension, humeroradial, humeroulnar, blocked olecranon fossa). The anterior group limited by soft tissue is addressed by capsulotomy, releases, and lengthenings. This group requires careful neurolysis and protection of vascular structures. For anterior bony bridges, resection is combined with capsulotomy. The location of the forearm "insertion" site of the new bone dictates alternative procedures such as interposition or radial head resection. The condition of the joint is usually preserved in these cases, but arthroplasty must always be considered when injury has led to joint derangement. Posteriorly, limitations in motion are caused by a contracted scarred triceps, capsular contracture, or bony impingement and synostosis. Treatment requires posterior capsular release and triceps tenolysis. Bridging bone is excised, the olecranon partially excised, and the olecranon fossa reestablished. Attempts should be made to preserve the fat pad of the olecranon fossa, which can act as an effective interposition material. Although characterized by limited pronosupination, class IIB HO can be located in any of the six distinct anatomic sites previously outlined. Simple resection, with or without interposition, is useful for a majority of the HO that is coincident with the interosseous membrane, but the areas at the proximal and distal extent of the forearm may demand special procedures to restore motion.(ABSTRACT TRUNCATED AT 400 WORDS)