Genet et al.

2011

France

D&B=18

Case series

N= 86

Population: 86 SCI patients; 81%  SCI male; Mean age: 27.1 years old; Mean Delay from CNS damage to surgery : 13.1months.

Treatment: Charts of patients who underwent surgical resection for HO were examined.

1. Most common site of HO is 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).

Garland & Orwin 1989
USA
Downs & Black score=14
Case series
N=19

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

1. 3 of 24 hips operated on 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 was present.

Meiners et al. 1997
Germany
Downs & Black score=12
Case Series
Initial N=31 (43 hips); Final N=29 (41 hips)

Population: Mean age = 37.87 yrs; Gender: males = 28, females = 1; Level of injury: paraplegia = 19, tetraplegia = 10; Severity of injury: complete 22, incomplete 7; Time since injury = 17-298 months; 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: ROM – flexion & extension; pre-operatively, post-operatively, intra-operatively & @ follow-up.

1. Mean ROM pre-operatively = 21.95°.
2. Mean ROM intra-operatively = 94.51°.
3. Mean ROM at follow-up (M=4.2yrs) = 82.68°.

Schuetz et al. 2005
Switzerland
Downs & Black score=9
Case Series
N=7

Population: SCI: Age = 47-68 yrs; Gender: males = 7; Level of injury: thoracic = 1, tetraplegia = 2.
Treatment: All pts 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 hrs and gradually increasing for a total of 6-14 days.
Outcome Measures: Prevalence of HO.

No statistical results reported

1. None of the pts treated with pamidronate showed clinical, x-ray or lab signs of HO recurrence or new forming HO at time of F/U 5-54 months post-op.

Subbarao et al. 1987 USA
Downs & Black score=8
Case Series
N=5

Population: SCI: Age = 29-41 yrs; Time since injury = 18-197 mths.
Treatment: Didronel given 10 days – 2 wks preoperatively, medication withheld for immediate postop period (72 hrs) and continued for min. of 3 mos.  All 5 pts underwent wedge resection at hip to permit free movement of hip in flexion.
Outcome Measures: Effects of treatment.

1. All pts at last F/U were able to function independently in their wheelchairs except one but was able to function independently in a semireclining W/C.
2. Pts had severe restriction of ROM in involved joints.