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The posterior compartment is exposed with use of posterior central and lateral portals. Small incisions can be performed to visualize and protect the ulnar nerve before performing the next steps. The triceps muscle is elevated from the HO with use of a switching stick or a retractor through an additional posterior portal. The HO is usually resected starting from distal to proximal, with the shaver in the posterior central portal and the arthroscope in the posterior lateral portal. Before completing the procedure, it is important to obtain radiographic or fluoroscopic confirmation of complete removal of the HO.
Chronic HO (>6 months) can be removed arthroscopically, but sometimes, depending on the hardness of the metaplastic bone, it is not easy to obtain complete removal.
The proximal radioulnar synostosis can also be removed arthroscopically, with the radial nerve being protected with a retractor, by working around the radius anteriorly and using the distal biceps tendon as anatomical landmark.
In some cases, particularly those in which extensile HO is close to neurovascular structures, the use of a combination of arthroscopic and open techniques can be used to improve the safety of the procedure. In such cases, preoperative imaging is advised to assess the extent and location of HO and its relationship with the neurovascular structures.
Perioperative Strategies (Open or Arthroscopic)
Perioperative radiotherapy (700 rads seems to be the best choice), cryo-compression, immediate continuous passive motion, and assisted active motion are some of the suggested strategies to reduce the risk of recurrence and to obtain the best outcomes. Doxycycline and prednisone administration are currently administered to reduce the proinflammatory cytokines.
Outcomes
The reported outcomes of HO excision in terms of the recovery of a functional range of motion seem to be good, but the overall rate of complications (e.g., recurrence, fracture, infection, nerve palsies, wound complications) is around 20%. The rate of reoperation (including repeat excision of HO and nerve transposition) is around 10%4. The outcomes seem to be related to several factors, such as the extent of the HO, the timing of surgical excision (from 3 to 6 months), associated neurological contracture, and patient compliance with postoperative rehabilitation programs.
Conclusions
Excision of HO and release of soft-tissue contracture require knowledge of anatomy. Precise preoperative planning with use of radiographs, CT scans, and MRI scans is necessary in order to define not only the extent and location of the HO but also the joint congruency and associated bone deformity as well as the distance between the HO and neurovascular structures. The aim of the surgical procedure is to restore a functional range of motion and stability of the elbow. The choice of surgical technique (open, arthroscopic, or combined) is related to the extent and anatomical location of the HO, particularly with respect to its relationship with the neurovascular structures around the elbow. Salvage procedures such as interposition arthroplasty or total elbow arthroplasty are indicated in cases of irrecoverable joint incongruencies or bone deformities with progressive arthritic changes.
References
1. Hastings 2nd H, Graham TJ. The classification and treatment of heterotopic ossification about the elbow and forearm. Hand Clin 1994;10:417–37. 2. Davis EL, Davis AR, Gugala Z, Olmsted-Davis EA. Is heterotopic ossification getting nervous?: The role of the peripheral nervous system in heterotopic ossification. Bone. 2018;109:22–27. 3. Moore-Lotridge SN, Li Q, Gibson BHY, et al. Trauma-Induced Nanohydroxyapatite Deposition in Skeletal Muscle is Sufficient to Drive Heterotopic Ossification. Calcif Tissue Int. 2019;104(4):411–425. 4. Lee E.K , Namdari S, Hosalkar H.S, Keenan M.A, Baldwin K.D Clinical Results of the Excision of Heterotopic Bone Around the Elbow: A Systematic Review J Shoulder Elbow Surg 2013 May;22(5):716- 22. doi: 10.1016/j.jse.2012.11.020. 5. Ectopic ossification about the elbow Morrey BF, Harter G.D chapter 31 in The Elbow and its Disorders Morrey BF, Sanchez-Sotelo J eds Saunders–Elsevier 2009
CURRENT CONCEPTS
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