Heterotopic Ossification Workup
- Author: John Speed, MBBS; Chief Editor: Consuelo T Lorenzo, MD more...
See the list below:
- This test is not specific for HO but is of value in determining the severity of muscle involvement and may be helpful in planning treatment of HO. Rossier and colleagues showed in 1973 that patients with an acute form of HO after SCI have elevated CK levels that correlate with histologic involvement of muscle. Two subsequent studies found CK to be useful in the diagnosis and management of HO. Singh and coauthors reported significantly higher CK levels in patients with HO. Data published by Sherman and colleagues indicated that a higher level of CK ultimately correlates with a more severe form of HO, suggesting more widespread involvement of surrounding muscle.
- These results are promising, because they indicate that CK may reliably predict a higher risk of HO development, can help to predict the severity of a patient's HO, and can be used to follow treatment success.
- The initial stage of HO is manifested by a prominent inflammatory response. This acute reaction is accompanied by changes in levels of cytokines that stimulate the production of acute-phase proteins, one of these being C-reactive protein (CRP).
- A study by Estrores and colleagues indicated that the serum concentration of CRP correlates better than does the erythrocyte sedimentation rate with the inflammatory activity of HO after SCI. In their study, the normalization of CRP in serum was accompanied by a resolution of the inflammation of soft tissue. It seems that administering nonsteroidal anti-inflammatory drugs (NSAIDs) in the early phase of HO, as well as monitoring the serum CRP level, may provide added benefit in reducing the inflammatory reaction that is proposed to be an important factor in HO's genesis.
- The AlkP level, once a commonly used test, is not often employed today.
- In many patients, serum AlkP levels are not elevated in acute HO.
- The elevation can be nonspecific because of associated skeletal injuries or the surgical treatment of fractures.
- The serum AlkP level is of little value in determining the maturity of HO prior to surgical removal.
Bone scintigraphy 
Ideally, the use of diagnostic imaging should focus on the detection of nonmineralized HO, because the presently available medication, etidronate, can inhibit early mineralization. In this respect, bone scintigraphy and ultrasonography are recommended imaging studies for the early diagnosis of HO.
Bone scintigraphy is highly sensitive in the early diagnosis of HO. This is the most commonly used diagnostic study for HO.
Freed and colleagues evaluated the 3-phase bone scan in the detection of HO and found that a marked vascular blush and increased blood pool about the hips preceded the development of clinical HO by 2-4 weeks. The 3-phase bone scan using technetium-99m (99m Tc) diphosphonate is used in diagnosing and monitoring HO.
This is also used in the early diagnosis of HO about the hips. However, no data are available on the diagnostic value of ultrasonography in the diagnosis of HO in other joints (eg, knee, shoulder, elbow).
While plain radiography is highly specific in the diagnosis of HO, this method lacks sensitivity in early diagnosis. Because soft-tissue calcification must occur for radiographic evidence of HO to be present, radiographs are not helpful in the early stages. Radiologic examinations do not show evidence of HO until a flocculent, patchy appearance develops, as calcium is deposited about 7-10 days after the onset of clinical symptoms.
This patchy appearance coalesces and enlarges on subsequent examinations, and by 2-3 months, the boundaries of the HO demarcate with the appearance of mature bone. Radiography, however, is not reliable at assessing the maturity of HO, because more mature areas may hide immature areas.
CT scanning and MRI
Computed tomography (CT) scanning and magnetic resonance imaging (MRI) may be useful in delineating local anatomy prior to resection.
The role of CT scanning and MRI in the evaluation of other aspects of HO has not been well established.
A retrospective study by Bachman et al indicated that CT scanning can be used prior to the excision of HO from the elbow to distinguish the paths of the radial and median nerves and to precisely determine the distance of these nerves from the ossification. In a study of 22 patients who had undergone removal of HO from the elbow, CT scan distinguished the radial nerve from the HO in 21 patients and the median nerve from the HO in 17 cases. The distance of HO from these nerves (3 mm and 9 mm from the radial and median nerves, respectively) was also determined.
Three-dimensional (3D) stereolithography
This can be beneficial in the perioperative management of symptomatic HO. High-resolution CT scanning is used to create models that can assist during HO excision by allowing frequent intraoperative reference that contributes to the avoidance of iatrogenic neurovascular injuries.
See the list below:
- Biopsy has no role in the diagnosis of HO, but it has been considered as a means of helping to determine maturity.
- There is a possible risk of inadequate sampling, because mature and immature HO may be intermixed.
Kaplan FS, Xu M, Glaser DL, et al. Early diagnosis of fibrodysplasia ossificans progressiva. Pediatrics. 2008 May. 121(5):e1295-300. [Medline].
Shafer DM, Bay C, Caruso DM, et al. The use of eidronate disodium in the prevention of heterotopic ossification in burn patients. Burns. 2008 May. 34(3):355-60. [Medline].
Peterson JR, De La Rosa S, Sun H, Eboda O, Cilwa KE, Donneys A, et al. Burn Injury Enhances Bone Formation in Heterotopic Ossification Model. Ann Surg. 2013 May 12. [Medline].
Subbarao JV, Garrison SJ. Heterotopic ossification: diagnosis and management, current concepts and controversies. J Spinal Cord Med. 1999 Winter. 22(4):273-83. [Medline].
Pathophysiology of heterotopic ossification. Orthop Nurs. 2013 May-Jun. 32(3):178-9. [Medline].
Zychowicz ME. Pathophysiology of heterotopic ossification. Orthop Nurs. 2013 May-Jun. 32(3):173-7. [Medline].
Rossier AB, Bussat P, Infante F, et al. Current facts of para-osteo-arthropathy (POA). Paraplegia. 1973 May. 11(1):38-78. [Medline].
Wilson KW, Dickens JF, Heckert R, Tintle SM, Keeling JJ, Andersen RC, et al. Heterotopic ossification resection after open periarticular combat-related elbow fractures. J Surg Orthop Adv. 2013 Spring. 22(1):30-5. [Medline].
Bodley R, Jamous A, Short D. Ultrasound in the early diagnosis of heterotopic ossification in patients with spinal injuries. Paraplegia. 1993 Aug. 31(8):500-6. [Medline].
Snoecx M, De Muynck M, Van Laere M. Association between muscle trauma and heterotopic ossification in spinal cord injured patients: reflections on their causal relationship and the diagnostic value of ultrasonography. Paraplegia. 1995 Aug. 33(8):464-8. [Medline].
Hassard GH. Heterotopic bone formation about the hip and unilateral decubitus ulcers in spinal cord injury. Arch Phys Med Rehabil. 1975 Aug. 56(8):355-8. [Medline].
Downing MR, Knox D, Gibson P, et al. Impact of trochanteric heterotopic ossification on measurement of femoral bone density following cemented total hip replacement. J Orthop Res. 2008 Apr 10. [Medline].
Macfarlane RJ, Ng BH, Gamie Z, et al. Pharmacological treatment of heterotopic ossification following hip and acetabular surgery. Expert Opin Pharmacother. 2008 Apr. 9(5):767-86. [Medline].
Foruria AM, Augustin S, Morrey BF, Sánchez-Sotelo J. Heterotopic ossification after surgery for fractures and fracture-dislocations involving the proximal aspect of the radius or ulna. J Bone Joint Surg Am. 2013 May 15. 95(10):e661-7. [Medline].
Garland DE, Blum CE, Waters RL. Periarticular heterotopic ossification in head-injured adults. Incidence and location. J Bone Joint Surg Am. 1980 Oct. 62(7):1143-6. [Medline].
Singh RS, Craig MC, Katholi CR, et al. The predictive value of creatine phosphokinase and alkaline phosphatase in identification of heterotopic ossification in patients after spinal cord injury. Arch Phys Med Rehabil. 2003 Nov. 84(11):1584-8. [Medline].
Sherman AL, Williams J, Patrick L, et al. The value of serum creatine kinase in early diagnosis of heterotopic ossification. J Spinal Cord Med. 2003. 26(3):227-30. [Medline].
Estrores IM, Harrington A, Banovac K. C-reactive protein and erythrocyte sedimentation rate in patients with heterotopic ossification after spinal cord injury. J Spinal Cord Med. 2004. 27(5):434-7. [Medline].
Banovac K. The effect of etidronate on late development of heterotopic ossification after spinal cord injury. J Spinal Cord Med. 2000 Spring. 23(1):40-4. [Medline].
Freed JH, Hahn H, Menter R, et al. The use of the three-phase bone scan in the early diagnosis of heterotopic ossification (HO) and in the evaluation of Didronel therapy. Paraplegia. 1982 Aug. 20(4):208-16. [Medline].
Bachman DR, Kamaci S, Thaveepunsan S, et al. Preoperative nerve imaging using computed tomography in patients with heterotopic ossification of the elbow. J Shoulder Elbow Surg. 2015 Mar 11. [Medline].
Lindeque BG, Fleming ME, Waterman SS, Lewandowski LR, Chi BB. Use of 3-dimensional stereolithographic polymer models for heterotopic ossification surgical excision. Orthopedics. 2013 Apr 1. 36(4):282-6. [Medline].
Bradleigh LH, Perkash A, Linder SH, et al. Deep venous thrombosis associated with heterotopic ossification. Arch Phys Med Rehabil. 1992 Mar. 73(3):293-4. [Medline].
Varghese G, Williams K, Desmet A, et al. Nonarticular complication of heterotopic ossification: a clinical review. Arch Phys Med Rehabil. 1991 Nov. 72(12):1009-13. [Medline].
Banovac K, Williams JM, Patrick LD, et al. Prevention of heterotopic ossification after spinal cord injury with indomethacin. Spinal Cord. 2001 Jul. 39(7):370-4. [Medline].
Banovac K, Williams JM, Patrick LD, et al. Prevention of heterotopic ossification after spinal cord injury with COX-2 selective inhibitor (rofecoxib). Spinal Cord. 2004 Dec. 42(12):707-10. [Medline].
Choi WJ, Lee JW. Heterotopic ossification after total ankle arthroplasty. J Bone Joint Surg Br. 2011 Nov. 93(11):1508-12. [Medline].
Klaassen MA, Pietrzak WS. Platelet-rich plasma application and heterotopic bone formation following total hip arthroplasty. J Invest Surg. 2011. 24(6):257-61. [Medline].
Genet F, Ruet A, Almangour W, et al. Beliefs relating to recurrence of heterotopic ossification following excision in patients with spinal cord injury: a review. Spinal Cord. 2015 Feb 17. [Medline].
Strauss JB, Chen SS, Shah AP, et al. Cost of radiotherapy versus NSAID administration for prevention of heterotopic ossification after total hip arthroplasty. Int J Radiat Oncol Biol Phys. 2008 Jan 28. [Epub ahead of print]. [Medline].
Strauss JB, Wysocki RW, Shah A, Chen SS, Shah AP, Abrams RA, et al. Radiation therapy for heterotopic ossification prophylaxis afer high-risk elbow surgery. Am J Orthop (Belle Mead NJ). 2011 Aug. 40(8):400-5. [Medline].
Hoff P, Rakow A, Gaber T, Hahne M, Sentürk U, Strehl C, et al. Preoperative irradiation for the prevention of heterotopic ossification induces local inflammation in humans. Bone. 2013 Apr 6. [Medline].
Sautter-Bihl ML, Liebermeister E, Nanassy A. Radiotherapy as a local treatment option for heterotopic ossifications in patients with spinal cord injury. Spinal Cord. Jan 2000. 38(1):33-6.
Banovac K, Gonzalez F, Renfree KJ. Treatment of heterotopic ossification after spinal cord injury. J Spinal Cord Med. 1997 Jan. 20(1):60-5. [Medline].