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Heterotopic Ossification

Surgical Resection

Surgical resection of HO post SCI is a well established treatment but still somewhat controversial.

Author Year; Country
Research Design
Total Sample Size
Methods Outcome

Hollenberg & Mesfin, 2020; USA
Case Control N=28

Population: SCI with OPLL Group (n=12): Mean age: 59.7 yr; Gender: males=6, females=6; Level of injury: cervical=12; CM with OPLL Group (n=16): Mean age; 55.4 yr; Gender: males=7, females=9; Level of injury: NA.
Intervention: A retrospective chart review was performed for all patients who underwent surgical management for Ossification of the Posterior Longitudinal Ligament (OPLL) OPLL in an academic medical center between November 2006 and July 2019. Patients were categorized into 1 of 2 groups and compared on the basis of their initial presentation: 1) SCI with OPLL or 2) cervical myelopathy (CM) with OPLL.
Outcome Measures: Surgical approach, levels fused/decompressed, estimated blood loss (EBL), postoperative hospital length of stay, surgical complications, American Spinal Injury Association (ASIA) motor score (0-100) and impairment scale.

  1. The most common type of OPLL in both groups was segmental (21, 75%).
  2. The average levels fused/decompressed (p=0.0176), estimated blood loss (p=0.0204), and postoperative length of stay (p=0.0003) were all significantly higher in the SCI with OPLL group.
  3. There were significantly more anterior-only surgical approaches performed in the CM with OPLL group (p=0.0159).
  4. The motor score at admission (P=0.0005) and at latest follow-up (p=0.0003) for the SCI with OPLL group was significantly lower than the CM with OPLL group.
Yang et al. 2017; United States
Case Series

Population: Mean age: 58.25 yr; Gender: males=8; Severity of injury: AIS: A=4, B=3, D=1.
Interventions: Surgical resection, two patients had additional prophylactic radiation, and one had pharmacological prophylaxis.
Outcome Measures: Mortality, healed surgical site.

  1. One of the eight patients died at 9mo post-op.
  2. Six of the eight patients treated for HO healed well, while one had ongoing healing at 6 mo post-op.
Genet et al. 2011; France
Case Series

Population: Mean age: 27.1yr; Gender: males=70, females=16; Mean time since injry: 13.1 mo.
Treatment: Charts of patients who underwent surgical resection for HO were examined.
Outcome Measures: Recurrence of HO.

  1. Most common site of HO was hips (74.4%).
  2. HO recurrence was seen in 5.8% of patients.
  3. Sepsis was a common side effect post-surgery.
  4. Recurrence was not associated with etiology of injury (p=0.46) or sex (p=1.00).
  5. A significant association was found between recurrence and delay until first surgery for SCI (p<0.01).
Schuetz et al. 2005; Switzerland
Case Series

Population: Age range: 47-68 yr; Gender: males=7; Injury etiology: SCI=7; Level of injury: thoracic=1, tetraplegia=2.
Treatment: All patients underwent excision-surgery for removal of HO. Pamidronate was administered IV peri- and post-op, starting at a dose level of 120 mg for 1st 12 hr and gradually increasing for a total of 6-14 days.
Outcome Measures: Prevalence of HO.

  1. No statistical results were reported.
  2. None of the patients treated with pamidronate showed clinical, x-ray or lab signs of HO recurrence or new HO at time of F/U (5-54 mo post-op).
Meiners et al. 1997; Germany
Case Series
NInitial=31 (43 hips); NFinal=29 (41 hips)

Population: Mean age: 37.87 yr; Gender: males=28, females=1; Level of injury: paraplegia=19, tetraplegia=10; Severity of injury: complete 22, incomplete 7; Time since injury range: 17-298 mo; Hip side: L=16, R=23.
Intervention: Resection of HO of the hip via ventral approach. Post-operation: wk 1-irradiation of hip with a linear accelerator; Day 15–passive movement exercises implemented.
Outcome Measures: Range of motion (flexion and extension) pre-, post-, intra-operatively and at follow-up.

  1. Mean range of motion improved from 21.95° pre-operatively to 94.51° intra-operatively, to 82.68° post-operatively (mean=4.2 yr).
Garland & Orwin 1989; USA
Case Series

Population: Mean age=22.5yr; Level of injury: paraplegia=8, tetraplegia=11; Severity of injury: complete=12, incomplete=7.
Intervention: Records of those who underwent hip resection for HO between 1970 and 1985 were reviewed.
Outcome Measures: Range of motion, recurrence rate, and adverse effects.

  1. Of 24 hips operated on, three had similar or less motion when compared with preoperative motion, 15 had 10-39° improvement, and 6 had >40° improvement.
  2. Total recurrence rate was 92% (22 of 24 hips).
  3. A high number of complications, infections and blood loss occurred.
Subbarao et al. 1987; USA
Case Series

Population: Age range: 29-41 yr; Time since injury range: 18-197 mo.
Treatment: Etidronate given 10 days-2 wk preoperatively, medication withheld for immediate postop period (72 hr) and continued for minimum of 3 mo. All patients underwent wedge resection at hip to permit free movement of hip in flexion.
Outcome Measures: Function, range of motion.

  1. All patients at last follow-up could function independently in their wheelchairs except one (was able to function independently in a semi-reclining wheelchair).
  2. Patients had severe restriction of range of motion in involved joints.


A case control study by Hollenberg and Mesfin (2020) assessed the influence of traumatic SCI on the operative management of cervical ossification of the posterior longitudinal ligament (OPLL). A chart review of the medical records of 12 individuals with SCI and 16 individuals with cervical myelopathy (CM) who underwent surgical management for OPLL was performed. It was found that while most patients in both the SCI with OPLL group and the CM with OPLL group showed neurologic improvement after the surgery, patients with SCI had worse postoperative neurologic motor scores compared to those with CM.

The timing for surgical resection continues to split consensus with surgery being conducted once the ectopic bone has completely matured being considered the usual course of action. Despite that, there are growing calls for surgery to be delayed until the patient has fully recovered from their SCI (Gurcan et al. 2013). However, a delay in excision has been found to lead to a series of negative events such as increased risk of fracture, ankylosis, bone loss, and intra-articular lesions (Genêt et al. 2015).

Meiners et al. (1997) reported a case series of 29 individuals (10 with quadriplegia and 19 with paraplegia) who underwent HO resection at the hip followed by irradiation and eventually passive range of motion exercises. Mean hip range of motion increased from 21.95º pre-operatively to 94.51º intra-operatively and 82.68º at four year (mean) follow-up. Garland and Orwin (1989) also reported that HO excision improves range of motion in 19 individuals with SCI. They found that the largest gain of function occurred intra-operatively followed by a large loss of function within the first six months. At final follow-up (six years post-surgery), three of 24 hip joints where HO was surgically excised had similar or less motion when compared with preoperative motion, 15 improved between 10° and 39°, while six showed greater than 40° improvement.Yang et al. (2017) found similar rates of improvement following HO resection. In a case series with eight patients that underwent surgical resection, six healed well, one patient had ongoing healing at 6 months due to a post-operative infection, and one patient died (Yang et al. 2017).

Some studies stress that surgical resection must be followed up by prophylaxis, either radiation therapy, NSAID or bisphosphonates due to high recurrence rates after surgery alone. A case study by Gurcan et al. (2013) investigated the use of surgical resection in a patient with total ankylosis of the right hip following a T8-T9 fracture. Upon excision of the cephalad mass, the patient’s hip could be flexed to 100o and abducted to 30o on the operating table, indicating a successful operation. At post-surgery, the patient completed passive movements of the hip, and was treated with a single dose of radiation (eight Gy) and a prescription for indomethacin with a dosage of 150mg a day. At 12-month follow-up post-surgery, the range of motion in the hip remained preserved with no recurrence of HO or ankylosis.

The effectiveness of surgical excision followed by bisphosphonates was examined in two case series (Schuetz et al. 2005Subbarao et al. 1987). Etidronate treatment post-surgical excision showed that patients were able to function independently in a wheelchair; however, they had severe restrictions in their range of motion (Subbarao et al. (1987). Surgical excision supplemented with pamidronate treatment resulted in no recurrence of HO post-surgery (Schuetz et al. 2005).

Genêt et al. (2015) conducted a review of the literature regarding recurrence rates of HO after surgical excision. A finding of concern was the lack of consensus towards the classification of HO and risk of recurrence and whilst some studies have attempted, the authors point out that these are based on observations and are merely descriptive. Moreover, the review was not able to clarify ideal timing for surgical resection, in part due to disparate rates of recurrence post-surgery. A prominent issue of HO recurrence is the definition of recurrence. Genêt et al. (2015) highlight that some patients are not deemed to have had recurring HO post-surgery if the patient’s functioning is not impaired, and adds that pre- and post-surgical care are not standardized with early rehabilitation such as limb mobilization often being delayed due to inflammation and treated with NSAIDs instead.


There is level 3 evidence (from one case control study; Hollenberg & Mesfin, 2020) that patients with SCI complicated by OPLL may have worse preoperative and postoperative motor function compared to patients with CM and OPLL.

There is level 4 evidence (from four case series: Garland & Orwin 1989Meiners et al. 1997Genet et al. 2011; Yang et al. 2017) that resection of HO about the hip post SCI can dramatically improve restricted hip range of motion; however, post-surgical recurrence and complications are a concern for this treatment.

There is Level 4 evidence (from one case series: Schuetz et al. 2005) that surgical resection combined with pamidronate treatment effectively halts secondary HO progression.

There is level 4 evidence (from one case series: Subbarao et al. 1987) that surgical resection combined with etidronate treatment improves independence with wheelchair use but contributes to reduced range of motion.

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