[Risedronate: a possible treatment for extraosseous calcification]

A case report of 51 year-old female, diagnosed as CREST syndrome, presenting with an ectopic calcification in the left shoulder joint, which disappeared soon after the start of risedronate. She had been taking steroid and NSAIDs for the past four years, but the pain and the range of motion of her shoulder became worse and restricted progressively during the last three years only to form extraosseous calcification. Laboratory data showed normal renal function, no inflammatory changes, and no abnormalities in calcium and and phosphate metabolism including parathyroid hormone. Risedronate was administered for glucocorticoid-induced osteoporosis. Although the bone turnover markers, such as serum NTX (N-terminal telopeptides of type I collagen) and BSAP (bone specific alkaline phosphate), did not show remarkable changes, the pain disappeared a week later and the range of motion recovered a month later. The X-ray at 6 months risedronate treatment revealed a complete disappearance of the ectopic calcification. Risedronate, probably through a different process from etidronate, could prevent extraosseous calcification.

C-reactive protein and erythrocyte sedimentation rate in patients with heterotopic ossification after spinal cord injury

BACKGROUND/OBJECTIVE

Formation of heterotopic ossification (HO) in soft tissue after spinal cord injury (SCI) is associated with various degrees of inflammation. Recent studies have shown that inhibition of inflammatory reaction with nonsteroidal anti-inflammatory drugs is an effective prevention of HO after SCI. The goal of this study was to monitor the activity of the most widely used indicators of acute inflammation--namely, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)--in patients with HO.

METHODS

In a retrospective study, the results of 37 patients with HO were evaluated. There were 25 patients with tetraplegia and 12 with paraplegia. The age (mean +/- SD) of the patients was 28 +/- 8 years (range = 19-46 years). The patients were admitted to the rehabilitation center 2 to 5 weeks after SCI. HO was confirmed by bone scintigraphy. Blood samples were obtained from the patients at the time of diagnosis of HO and during the therapy. ESR was measured with the Westergren method, and serum CRP was determined by enzyme-linked immunosorbent assay.

RESULTS

In the acute stage of HO, both tests were elevated in all patients. In the later stages when clinical signs and symptoms of inflammation were resolving, both tests showed a gradual decline. When clinical signs and symptoms of inflammation (fever, acute soft tissue swelling, and erythema) were not present, the concentration of CRP was normal in 91.2% of patients, whereas only 17.6% of patients had normal ESR. Mean serum concentrations of CRP were 8.9 +/- 5.6 mg/L in the inflammatory phase and 0.9 +/- 0.6 mg/L in the noninflammatory phase.

CONCLUSION

The data indicate that serum CRP is a useful and more specific test than is ESR for monitoring the inflammatory activity of HO after SCI. The normalization of CRP was seen during the first 3 to 4 weeks of etidronate therapy, indicating a resolution of acute-phase inflammatory reaction.

Colchicine inhibits heterotopic ossification: experimental study in rabbits

BACKGROUND

Heterotopic ossification is a common complication of hip surgery and musculoskeletal or brain trauma.

OBJECTIVES

To confirm by in vivo study that colchicine inhibits osteoblast cell proliferation with marked decrease in tissue mineralization.

METHODS

Heterotopic ossification was induced in three groups of New Zealand white rabbits (females, 6 months old, weight 3-3.5 kg) by injecting 2 ml bone marrow drawn from the iliac crest into their right thigh muscle. To prevent heterotopic ossification, colchicine (0.25 mg/ day) was administered orally for 4 weeks to two groups of adult rabbits: group A (preload group)--1 week preceding bone marrow injection; group B--on day of injection; and group C--control group.

RESULTS

After 4 weeks the rabbits were evaluated by radiographs and ultrasound for evidence of heterotopic ossification. At the end of the study histologic samples were taken from all the thighs. Imaging and histologic studies showed, with statistical significance, almost complete prevention of heterotopic ossification formation in group A (preload) and a marked decrease in group B, when compared with the controls where large new bone had formed at the injection site. These results indicated the inhibitory effects of colchicine on a bone-forming process in soft tissue such as heterotopic ossification.

CONCLUSIONS

The role of colchicine in preventing heterotopic ossification in other bone-forming conditions, such as hip arthroplasty or pelvic trauma, and after brain trauma, remains to be evaluated in a clinical setting.

Radiotherapy vs. nonsteroidal anti-inflammatory drugs for the prevention of heterotopic ossification after major hip procedures: a meta-analysis of randomized trials

PURPOSE

To evaluate the efficacy of radiotherapy (RT) vs. nonsteroidal anti-inflammatory drugs (NSAIDs) in the prevention of heterotopic ossification (HO) after major hip procedures.

METHODS AND MATERIALS

We conducted a meta-analysis of 7 randomized studies (n = 1143) comparing RT with NSAIDs. Data were combined across studies using fixed and random effects models. We conducted separate analyses for clinically significant HO (Brooker Grade 3 and 4) and for any HO (any Brooker grade).

RESULTS

Overall RT tended to be more effective than NSAIDs in preventing Brooker 3 or 4 HO (risk ratio, 0.42; 95% confidence interval [CI], 0.18-0.97) or any HO (risk ratio, 0.75; 95% CI, 0.37-1.71), but with significant between-study heterogeneity for the second analysis. The overall absolute risk difference for Brooker 3 or 4 HO was small (-1.18%; 95% CI, -2.45% to 0.09%). Subgroup analyses showed that early preoperative RT (16-20 hours before surgery) and acetylsalicylic acid were less effective. For postoperative RT, there was a significant dose-response relationship (p = 0.008): 6 Gy of RT was equally effective as NSAIDs, whereas increasing radiation doses were more effective.

CONCLUSIONS

Although absolute differences may be small, postoperative RT is on average more effective than NSAIDs in preventing HO after major hip procedures, and its efficacy is dose dependent.

Pharmacological interventions for treating acute heterotopic ossification

BACKGROUND

Heterotopic ossification (HO) is the formation of mature lamellar bone in soft tissue sites outside the skeleton. HO frequently complicates burns, arthroplasty, fractures, and spinal cord and brain injuries. It can impair joint function.

OBJECTIVES

To determine the efficacy of medications to treat acute HO on radiological, symptomatic, functional impairment, and disability outcomes.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Injuries Group specialised register, the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2004), MEDLINE (1966 to August 2004), EMBASE (1980 to August 2004), CINAHL (1982 to August 2004), other databases, reference lists of articles, and contacted trialists and drug companies. No language restrictions were applied.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials that assessed the efficacy of any medication for treating acute HO (confirmed by bone scintigraphy, radiography, ultrasonography, or biopsy) and which used radiography to grade post-treatment HO severity.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the study quality and extracted data. We analysed two dichotomous outcomes: no progression in HO grade (versus progression) and improvement in HO grade (versus no improvement).

MAIN RESULTS

Two randomised trials comparing disodium etidronate versus placebo were included (Ono 1988; Stover 1976), from which ninety-two participants with spinal cord injury had radiographically-proven HO at baseline. At the completion of the 12 week intervention, the Ono study but not the Stover study, suggested that disodium etidronate was associated with a significantly greater likelihood of successfully preventing the progression of radiographic HO grade, (relative risk (RR) 1.50; 95% confidence interval (CI) I 1.16 to 1.93; and RR 1.48; 95% CI 0.78 to 2.84 respectively) and a significantly greater likelihood of improvement in HO grade (RR 2.78; 95% CI 1.66 to 4.66; and RR 0.71; 95% CI 0.20 to 2.53 respectively). There was evidence of statistical heterogeneity for the latter outcome. Longer term radiographic, clinical or side effect outcomes were unavailable. Data was not pooled due to this heterogeneity and the inadequate duration of follow up.

REVIEWERS' CONCLUSIONS

Given the absence of long term radiographic outcomes in the included studies, there is insufficient evidence to recommend the use of disodium etidronate or other pharmacological agents for the treatment of acute HO. It has been previously suggested that disodium etidronate acts by delaying, rather than preventing, the mineralization of HO, and that mineralization may occur after treatment cessation in many cases, thereby negating the benefit of disodium etidronate on eventual HO grade. Further studies are required to assess all pharmacological treatments for acute HO with sufficient follow-up duration.

[Regulation of calcification by bisphosphonates]

Etidronate, an analogue of first generation of bisphosphonates, has inhibitory actions on mineralization and hydroxyapatite crystal formation, which is therefore used as a drug to treat ectopic ossification in cases with total hip arthroplasty and spinal cord injury. The effect of bisphosphonates to prevent calcification could be associated with the physical property to attach tightly to hydroxyapatite crystals in bone matrix. A recent investigation suggested that bisphosphonates might prevent arterial calcification through a mechanism associated with the enhanced production of parathyroid hormone-related peptide from vascular smooth muscle cells. A derivative of bisphosphonates to inhibit vascular calcification in atherosclerosis is expected and should be developed in the near future.

Prevention of heterotopic ossification after spinal cord injury with COX-2 selective inhibitor (rofecoxib)

STUDY DESIGN

A randomized, prospective, double-blind, placebo-controlled clinical trial.

OBJECTIVES

To determine the effect of COX-2-selective inhibitor on the prevention of heterotopic ossification (HO) after spinal cord injury (SCI).

SETTING

County and University Teaching Hospital, Miami, FL, USA.

METHODS

A total of 76 patients were enrolled in the study. Among them, 39 patients received placebo, and 37 received COX-2-selective inhibitor rofecoxib 25 mg daily for a period of 4 weeks. Prevention was started 3 weeks after spinal cord injury (SCI). In both groups of patients there was similar age as well as the level of SCI and ASIA impairment scale. Two methods were used to diagnose early HO, clinical symptoms and bone scintigraphy. Radiography was used for diagnosis of late stages of HO development.

RESULTS

A significantly lower incidence of HO was found in the rofecoxib group (13.4%) than in the placebo group (33.3%: P<0.05). In patients receiving rofecoxib, there was a 2.5 times lower relative risk of developing HO than in the placebo group (95% CI, 2.3-6). There were no patients who discontinued the study due to adverse effects of medication.

CONCLUSION

Our data suggest that COX-2-selective inhibitor rofecoxib is an effective medication in prevention of HO after SCI.

Comparison of robotic-assisted and manual implantation of a primary total hip replacement. A prospective study

BACKGROUND

Robotic-assisted total hip replacement has become a common method of implantation, especially in Europe. It frequently has been postulated that robotic reaming would result in an improved clinical outcome due to the better fit of the prosthesis, but that has never been demonstrated in a prospective study, to our knowledge. The purpose of this study was to compare robotic-assisted implantation of a total hip replacement with conventional manual implantation.

METHODS

One hundred and fifty-four patients scheduled for total hip replacement were randomly assigned to undergo either conventional manual implantation of an S-ROM prosthesis (eighty patients) or robotic-assisted implantation of such a prosthesis (seventy-four patients). The five-axis ROBODOC was used for the robotic-assisted procedures. Preoperatively as well as at three, six, twelve, and twenty-four months after surgery, the scores according to the Harris and Merle d'Aubigné systems and the Mayo clinical score were determined. Radiographs made at these intervals were analyzed for evidence of loosening, prosthetic alignment, and heterotopic ossification.

RESULTS

Thirteen (18%) of the seventy-four attempted robotic implantations had to be converted to manual implantations as a result of failure of the system. The duration of the robotic procedures was longer than that of the manual procedures (mean and standard deviation,107.1 +/- 29.1 compared with 82.4 +/- 23.4 minutes, p < 0.001). Limb-length equality (mean discrepancy, 0.18 +/- 0.30 compared with 0.96 +/- 0.93 cm, p < 0.001) and varus-valgus orientation of the stem (mean angle between the femur and the shaft of the prosthesis, 0.34 degrees +/- 0.67 degrees compared with 0.84 degrees +/- 1.23 degrees, p < 0.001) were better after the robotic procedures. At six months, slightly more heterotopic ossification was seen in the group treated with robotic implantation. The group treated with robotic implantation had a better Mayo clinical score at six and twelve months and a better Harris score at twelve months; however, by twenty-four months, no difference was found between the groups with regard to any of the three scores. Dislocation was more frequent in the group treated with robotic implantation: it occurred in eleven of the sixty-one patients in that group compared with three of eighty in the other group (p < 0.001). Recurrent dislocation and pronounced limping were indications for revision surgery in eight of the sixty-one patients treated with robotic implantation compared with none of the seventy-eight (excluding two with revision for infection) treated with manual insertion (p < 0.001). Rupture of the gluteus medius tendon was observed during all of the revision operations.

CONCLUSIONS

The robotic-assisted technology had advantages in terms of preoperative planning and the accuracy of the intraoperative procedure. Disadvantages were the high revision rate; the amount of muscle damage, which we believe was responsible for the higher dislocation rate; and the longer duration of surgery. This technology must be further developed before its widespread usage can be justified.

[Biphosphonates in children: present and future]

Biphosphonates are synthetic analogs of the natural pyrophosphate molecule, introduced primarily for the treatment of Paget disease of bone. Their main mechanism of action consisting in an inhibition of osteoclastic activity is critical for treatment of disorders including an increased bone resorption. In childhood osteoporosis (especially osteogenesis imperfecta), hypercalcemia and heterotopic calcifications are the three main situations in which they have been successfully used, with however few follow-up and no controlled studies. The evolution of these compounds generating more potent products, given orally, with limited effect on bone mineralization should allow an extension of their use in pediatric patients. Multicentric studies are now necessary to specify their efficacy and guidelines for use in children.

[Treatment of neurogenic heterotopic ossifications (NHO) in brain injured patients: review of literature]

This article is a review of the literature about treatment of neurogenic heterotopic ossifications (NHO) in brain injured patients, from analysis of the main data bases (Medline, Embase, Reedoc). In spite of the hope they arouse in the seventies, biphosphonates, including etidronate, have not demonstrated their efficiency to inhibit NHO in clinical practice. In fact a very early diagnosis, with the scintigraphic overactivity of the joint area and the increase of serum alkaline phosphatases, must lead to begin passive motion and postures, and may contribute to save functional range of motion. Yet, when joint stiffness or even ankylosis have led to severe functional disorders, surgery with NHO resection is the only way; it looks more reliable to manage it when NHO is mature, after a delay of more than 12 months after the first signs, but earlier operations have been reported without an enhanced risk of recurrence; this surgery must be associated with continuous passive motion for several weeks; radiation therapy and/or non-steroid anti-inflammatory drugs have been proposed in the immediate after-surgery period, but their role is still discussed.

[Digital planimetry for exact assessment of peri-articular ossification]

PROBLEM

Currently, non-steroidal anti-inflammatory drugs (NSAID) and radiation have become established as methods of choice in the prevention of ectopic ossifications after total hip replacement. The most effective doses is still not known exact for both. Conventional classification systems only permit a rough distinction of ossifications, so they cannot be used for an exact quantitative measuring. Further, only a limited number of categories can be distinguished. We wanted to find out whether a quantitative measurement of ossifications can be realized, and if small differences in prophylactic effect can be detected in this way.

METHOD

By computerized digitized planimetry, we measured ossifications of patients after total hip replacement on plain X-rays of the pelvis. We followed 57 patients for up to 2 years after operation. After marking the ossifications they were measured by drawing the outline with a magnifying glass-mouse. We checked all aspects of precision and reproducibility of the measurements and the comparability with an established classification method (Brooker).

RESULTS

The digitized planimetry could be performed on all patients X-rays. It gave a much more differentiated picture compared to the method of Brooker. The method is simple and reproducible, but time consuming.

CONCLUSIONS

Digitized planimetry allows a very exact measurement of ectopic bone formation. Compared to conventional classification systems, it differentiates more subtly. In limited, well controlled studies slight differences of prophylactic methods on ossifications can be evaluated. New developments in X-ray technology will make the handling of this method even easier.

The effect of etidronate on late development of heterotopic ossification after spinal cord injury

Forty patients with spinal cord injury (SCI) and heterotopic ossification (HO) were treated with etidronate and followed after therapy to determine the effects of long-term medication on heterotopic bone formation. Eighteen patients had tetraplegia and 22 had paraplegia. Early diagnosis of HO (positive bone scintigraphy and negative radiographic findings of HO) was established by 3-phase bone scintigraphy using 99m technetium-labeled methylene diphosphonate. All patients underwent treatment with etidronate, first with intravenous administration of 300 mg/day for 3 days followed by an oral administration of 20 mg/kg/day for 6 months. Eleven patients (27.5%) developed radiographic evidence of HO from 1.5 to 6 years after therapy. A low degree of HO was found in these patients; 8 had grade I and 3 had grade II ectopic ossification (Brooker's scale). The analysis of data showed that 2 different types of ectopic bone may form in the later stages after SCI. In 5% of patients, HO was found in the same anatomical site initially and finally, suggesting a "rebound" in mineralization of bone matrix not prevented by the administration of etidronate. The other type of HO was found in the majority of patients (95%) where the localization of HO showed different involvement of joints than initially, indicating de novo appearance of HO following SCI. The data suggest that etidronate given for a prolonged period in higher doses has, in addition to an inhibitory effect on crystal formation, a cellular effect on bone-forming cells.

Early excision of heterotopic bone in the forearm

Five patients undergoing early excision of heterotopic bone in the forearm with radiation therapy and indomethacin were reviewed. Inciting causes of heterotopic ossification included distal biceps tendon repairs, ulna fractures, and a fracture of the radius and ulna. Preoperative forearm rotation arc averaged 17 degrees. Excision was performed at an average of 4 months after injury. Patients were administered 500 to 1,000 cGy of radiation after surgery and received indomethacin for 6 weeks. At an average of 37 months after surgery the forearm rotation arc averaged 136 degrees. All patients had resumed normal activities and had no radiographic recurrence of heterotopic bone or other treatment complications. In the past excision of heterotopic ossification after more than 12 months has been advocated to prevent recurrence. The results of this study suggest that early excision with radiation therapy and indomethacin is a viable option in treating and preventing recurrent heterotopic ossification in the forearm.

Polyarticular heterotopic ossification complicating critical illness

A patient with generalized heterotopic ossification (HO) complicating critical illness due to necrotizing pancreatitis is described; data on two other cases with HO are briefly presented. The clinical features, prevention and therapy of HO are discussed. The effect of surgical therapy of the HO in our three patients was good.

Prevention of heterotopic bone formation after total hip arthroplasty: a prospective randomised study comparing postoperative radiation therapy with indomethacin medication

Heterotopic ossification (HO) after total hip arthroplasty is known to be a major complication with an impact on the functional outcome. Efforts have been made to prevent the occurrence of HO by means of either radiation therapy or pharmacotherapy. To date, there are no data available regarding the relative benefit of radiation versus medication with non-steroidal anti-inflammatory drugs. The objective of this study was to compare single-dose 600-cGy radiation therapy with indomethacin medication for their effect on the prevention of heterotopic bone formation after total hip arthroplasty. In all, 154 patients were included in the study. All patients underwent primary total hip arthroplasty due to osteoarthritis. Patients were randomly assigned to three different therapeutic groups. (a) The radiation group received a single radiation dose of 600 cGy between the 2nd and 4th postoperative day. (b) The indomethacin group received an oral application of indomethacin 2 x 50 mg per day from the 1st to 42nd postoperative day. (c) The control group received neither radiation nor indomethacin medication. There were significant group differences (P < 0.001). A least significant difference test (LSD) revealed that the mean of the control group was significantly different from that of the radiation and indomethacin groups. The 13 patients (8.4%) classified Brooker 3 or 4 were all in the control group. Again, this effect was statistically significant (chi-square, P < 0.001). In conclusion, this study demonstrated that both radiation and indomethacin therapy are effective in the prevention of postoperative HO. The choice for either one of the treatments has to be based on availability, contraindications, side-effects, practicability, standardisation and cost. Based on these considerations together with the results of this study, we currently use postoperative radiation with 600 cGy for all patients undergoing primary total hip arthroplasty.

Heterotopic bone formation after joint replacement

Bone formation outside the skeleton, heterotopic ossification (HO), is a common finding on radiographs from patients who have undergone arthroplasty of the hip, knee, shoulder, or elbow. Only a minority (5%-10%) of the patients with HO suffer from any consequence of the condition. However, because of the great number of joint replacements performed, the number of patients with decreased function that can be attributed to HO is significant. The risk for severe HO after total hip arthroplasty is increased in 1) patients who have developed HO after previous surgery, 2) men with hypertrophic osteoarthrosis and, 3) in patients with ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis. The same risk factors are probably valid for other joints as well. Two preventive treatments for HO after hip arthroplasty, nonsteroidal anti-inflammatory drugs and local radiation, are effective and reasonably well documented but are associated with potential side effects. Thus, a treatment protocol to prevent HO must identify the patients at risk for severe HO and recommend them treatment with one of these two modalities. Based on the current literature, we suggest that the patients at risk for severe HO be treated with 1) nonsteroidal anti-inflammatory drugs from the day of surgery for 7-10 days or 2) preoperative (or postoperative) radiation in a single dose.

Heterotopic ossification in non-traumatic myelopathies

Heterotopic ossification (HO) is an important complication of spinal cord and brain injuries but is rarely reported among patients with non-traumatic myelopathies. In a prospective study on medical problems seven (6.04%) among the 114 subjects with non-traumatic myelopathies had heterotopic ossification. All of them had involvement of hip joints. The co-morbid conditions were: urinary tract infection, seven; spasticity, three; pressure sores, five; and deep venous thrombosis, one. The initial diagnosis was often other than heterotopic ossification. Erythrocyte sedimentation rate and serum alkaline phosphatase levels were elevated in all subjects. Following rest and non-steroidal anti-inflammatory drugs, the range of motion improved in two patients. Heterotopic ossification can occur in patients with non-traumatic myelopathies and has risk factors and clinical features similar to patients with traumatic spinal cord injury. A high index of suspicion about this complication is necessary for early diagnosis and prompt intervention.

[Indomethacin--short-term therapy vs. single low dosage radiation for prevention of periarticular ossifications after total hip endoprosthesis]

INTRODUCTION

With a general incidence of about 40% periarticular ossifications (PAO) constitute one of the more frequent complications after total hip arthroplasty. A prospective, randomized therapy--study investigates the prophylactic values of Indomethacin-Short-Term-Therapy and Single-Dose-Radiatio, respectively.

MATERIAL AND METHODS

Consecutive patients for elective, cementless THA were randomized; the Indomethacin-Group (A, n = 31 at the end of the study) was admitted 100 mg Indomethacin/supp. at the day of operation and 3 x 25 mg orally from postoperative day 1 to 10. Other NSAID were not given. The Radiatio-group (B; n = 19) was irradiated by a single dose of 6 Gy within postoperative days 1 to 4; no NSAID were admitted. Follow up was at dismissal and after 6 (NU 1) and 12 (NU 2) months. Incidence and severity of PAO and the clinical objective and subjective results were registered.

RESULTS

Age- and side-distribution as well as the etiologies were comparable in both groups. All patients took part in NU 1 and 90% in NU 2. There were no major differences in the incidence of postoperative PAO in both groups. In 68% (A) and 53% (B), resp., there were no PAO at dismissal and after six months, PAO of Brooker Grade I and II were seen in 30 (A) and 47% (B), resp., PAO of Grade III and IV--those having generally clinical relevance--did not occur at all. These results were confirmed after 12 months. The clinical objective result ameliorated between admission and dismissal by an average of 3.5 points and by another 2 points between dismissal and NU 2.

DISCUSSION

The results show that Indomethacin-Short-Term-Therapy as well as Single-Dose-Radiatio with 6 Gy can reliably prevent the occurrence of severe PAO. Both therapeutic concepts therefore can be employed as prophylaxis in primary endoprosthetic operations. The choice between the two procedures will then mainly be determined by given logistic conditions in the clinic, specific contraindications of the patient and financial considerations.

[Prevention of periarticular ossification--with results of a randomized, double-blind study comparing acemetacin versus indomethacin]

We examined the effect of NSAR in the prophylaxis of heterotopic ossifications after hip arthroplasty. During a randomized doubleblind study 59 patients took Indometacin and 60 patients Acemetacin for three weeks after the operation. All of them got a thrombosis prophylaxis with Heparin and a short term antibiotic prophylaxis. The range of ossifications was checked three months after the operation according to Arcq. The proportion of patients with no clinical symptoms (grade 0 or 1) was 92.3% in the indometacin group and 98.2% in the acemetacin group. Because of side effects (mainly gastrointestinal) 7 patients (11.9%) in the indometacin group and 5 patients (8.3%) in the acemetacin group stopped the study. In a previous study we had examined the effect of thrombosis prophylaxis by Heparin on the heterotopic ossifications. These results could now be taken for comparison. According to these results the examined NSAR Indometacin and Acemetacin raised the group of low grade heterotopic ossifications. The higher grades (2 degrees and 3 degrees according to Arcq) were only be seen in less than 5%. That is why we recommend the NSAR (Acemetacin or Indometacin) generally after hip arthroplasty as prophylaxis of heterotopic ossifications.

Prevention of heterotopic ossification after total hip replacement. A prospective, randomised study using acetylsalicylic acid, indomethacin and fractional or single-dose irradiation

We have carried out a prospective, randomised study of prophylaxis for heterotopic ossification (HO) comparing indomethacin for 7 and 14 days, acetylsalicylic acid, and fractional (4 x 3 Gy) or single exposure of 5 or 7 Gy irradiation after operation. We initially had 723 patients (733 hip replacements), but after withdrawals there were 685 hips of which 18.4% developed HO; 14% were grade I, 2.9% grade II and 1.5% grade III of the Brooker classification. We compared the results between these groups with those of a matched control series and found that indomethacin, 2 x 50 mg for 7 and 14 days, and postoperative irradiation of 4 x 3 Gy or 1 x 7 Gy, significantly reduced the development of HO compared with the control group. Patients in the acetylsalicylic acid group and those with a single irradiation of 5 Gy after operation developed significantly more ossification than those in the indomethacin and other irradiation groups. We suggest the use of 2 x 50 mg of indomethacin with mucoprotection for seven days as prophylaxis against HO after total hip replacement for all patients. A single irradiation of 7 Gy is recommended for patients who have developed HO after previous operations or to whom administration of indomethacin is contraindicated.

Prolonged fever and heterotopic ossification in a C4 tetraplegic patient. Case report

Prolonged fever is an uncommon diagnostic problem in a spinal cord injury patient. The underlying causes include recurrent infections, thromboembolic phenomena and central fever. We report a case of heterotopic ossification in a traumatic C4 tetraplegic patient presenting as prolonged fever of 3 months' duration. Treatment with oral indomethacin led to prompt resolution of the fever and acute manifestations of heterotopic ossification. The efficacy of indomethacin in the treatment of heterotopic ossification in spinal cord injury needs to be further confirmed in larger studies.

[Heterotopic ossification and vascular compression]

Heterotopic ossification is common in patients with spinal cord or brain injury. Whereas the articular complications of heterotopic ossification have been well documented, the vascular complications are less well known. We report three cases with vascular compression and discuss the diagnosis and treatment in the light of a review of the literature.

Vocal cords dysfunction resulting from heterotopic ossification in a patient with burns

Limitation of movement of vocal cords developed in a 38-year-old man after he received a 45% second- and third-degree burn with ossification about the cricoarytenoid joints, which indicated that the lesion had been caused by heterotropic ossification. To the best of our knowledge, this is the first report in medical literature of heterotopic ossification as a mechanical cause of vocal cords dysfunction in the patient with critical burns. Diphosphonate (Didronel) treatment has improved the function of the vocal cords after 11 months of therapy.

Rachitic syndrome after disodium etidronate therapy in an adolescent

A 12-year-old patient with a severe traumatic brain injury developed heterotopic ossification (HO) with rapidly decreasing range of motion in multiple joints despite intensive passive range of motion exercises and the use of nonsteroidal antiinflammatory drugs (NSAIDs). His alkaline phosphatase was markedly elevated. Etidronate, 20mg/kg/d was used to control the ossification. After 7 months of continual etidronate use, the patient developed periarticular pain with widened growth plates, suggesting a rachitic syndrome. Serum laboratory panel including calcium, phosphorous, alkaline phosphatase, and vitamin D were normal. After 3 months off etidronate, radiological studies showed growth plate calcification, though not before development of bilateral slipped femoral capital epiphyses. Further improvement and resolution of all complications occurred 5 months after discontinuation of etidronate. Rachitic syndromes secondary to didronel use in a clinical setting has not been previously reported. Other possible causes for a rachitic syndromes were not present. Alternate treatments for children with or at risk for HO should be considered.

[Idiopathic heterotopic ossification]

Three cases of localized, benign heterotopic ossification, occurred in the hip joint region, are presented. The aspects of the pathogenesis, differential diagnosis and prognosis are briefly discussed.

Intravenous disodium etidronate therapy in spinal cord injury patients with heterotopic ossification

The goal of the present study was to use intravenous etidronate in the acute phase of heterotopic ossification (HO) in an attempt to achieve a high initial drug concentration at the site of the active ectopic ossification. The study included 27 consecutive patients with an acute onset of HO after spinal cord injury (SCI). The three-phase bone scan was used to confirm clinical diagnosis of HO. Disodium etidronate (Didronel) 300 mg was administered intravenously daily for 3 to 5 days. In 20 patients there was a rapid (1-2 days) decrease of soft tissue swelling (p < 0.01) with no side effects associated with the intravenous administration. In seven patients there was minimal or no improvement of edema after intravenous etidronate. In these patients deep vein thrombosis was found in the affected limbs. The effect of high dose etidronate on HO was determined in the group of 13 patients with positive clinical and scintigraphic finding of an acute HO, but negative radiographic studies. After intravenous administration of etidronate for 3 days (300 mg/day) the drug was continued orally with 20 mg/kg/day for 6 months. A placebo was not used in this study. In eight patients there was no radiographic evidence of HO after therapy while two patients had minimal ossifications. In three patients therapy was interrupted and all developed HO in 1-2 months.

Prevention of heterotopic ossification (HO) after total hip replacement: randomized high versus low dose radiotherapy

In a prospectively randomized study 60 hips at high risk for heterotopic ossification (HO) received prophylactic radiotherapy (RT). Randomization was performed between a low dose (LD-RT) of 5 x 2 Gy (arm A: 32 patients) and a high dose (HD-RT) of either 10 x 2 Gy (arm B1; 8 patients) or 5 x 3.5 Gy (arm B2; 20 patients). Relevant patient and risk factors were equally distributed in both treatment arms. 4 (7%) patients developed treatment failures. A short delay of RT after postoperative day (POD) 4 was significantly correlated with failure (p < 0.001). The results suggest no difference in prophylactic efficacy between LD-RT and HD-RT treatment. 2/19 (11%) patients receiving additional diphosphonates and 2/18 (11%) on no medication failed RT treatment, but none on indomethacin did so. In conclusion, immediate postoperative RT has been shown to be an effective prophylactic treatment.

[Experimental study on the spinal lesions in hyperostotic mouse (twy/twy): special reference to the pathogenesis of the ossification of the spinal ligaments and to the action of ethane-1-hydroxy-1, 1-diphosphonate (EHDP)]

The hyperostotic changes in the spine of the twy mouse and the action of ethane-1-hydroxy-1, 1-diphosphonate (EHDP) on those hyperostotic changes were studied histomorphometrically. The periosteal bone formation and the endosteal bone resorption in the anterior cortex of the vertebral bodies of the twy mouse continued even after maturation, resulting in the anterior cortex shifting to the anterior direction. In parallel with these changes, calcification in the enthesis (to which spinal ligaments and the outer layer of disc fibrosis are attached) continued, ending in ankylosis of the whole spine. It was similar to a membranous ossification. Moreover calcification in these regions was most sensitively inhibited by EHDP and reappeared as soon as the discontinuation of EHDP. These findings showed that the pathogenesis of the twy mouse was the hyperostosis which continued even after maturation in the genetical region of a membranous ossification, especially in the enthesis. Further they appeared to be similar to the initial changes in ankylosing spinal hyperostosis or the ossification of the spinal ligaments. In addition, our results provided evidence for the usefulness of EHDP in the twy mouse.

Nonsteroidal anti-inflammatory drugs for prevention of heterotopic ossification after total hip arthroplasty

Nonsteroidal anti-inflammatory drugs (NSAID) have been proven highly effective as prophylaxis for periarticular heterotopic ossification (HO) following total hip arthroplasty (THA) both when given to patients considered to be at risk for this complication, and in consecutive double-blind studies. Treatment with a standard dosage for 10 days starting on the day of surgery seems to be adequate for the prophylactic effect. Furthermore, NSAID are effective in preventing recurrence of HO after resection.

The suppression of heterotopic ossification after total hip arthroplasty

In a double-blind prospective randomised study we examined the effects of Diclofenac on heterotopic ossification after hip arthroplasty. Either the drug, or a placebo, was given by mouth to 158 patients in doses of 3 x 50 mg for 6 weeks. Diclofenac resulted in highly significant improvement (p less than 0.0001 versus controls) without severe side-effects. Heterotopic ossification decreased from 55% in the placebo to 15%. Significant degrees of heterotopic ossification did not occur with the drug. Movement of the hip was considerably increased after operation. We recommend Diclofenac prophylaxis against heterotopic ossification after hip operations in view of the serious clinical effects of this complication and its quoted incidence of 15% to 80%.

Deep venous thrombosis associated with heterotopic ossification

The differential diagnosis of the swollen lower extremity in the patient with spinal cord injury includes deep venous thrombosis, fracture, cellulitis, joint sepsis, heterotopic ossification, hematoma formation, and neoplasm. A patient with an asymmetrically swollen limb who was found to have concurrent ipsilateral acute deep venous thrombosis and active heterotopic ossification is described. The diagnostic workup included various laboratory and radiologic studies. Therapy included anticoagulation with heparin and warfarin. To treat the heterotopic ossification, indomethacin, etidronate, and graded range of motion were used. We learned from this patient and several similar cases that acute deep-venous thrombosis and active heterotopic ossification may occur concurrently, and therapeutic anticoagulation did not lead to bleeding within or around the area of active heterotopic ossification. The possibility of a relationship between heterotopic ossification and deep venous thrombosis is presently being studied at our institution.

[Prevention of periarticular ossification following endoprosthetic hip replacement using postoperative irradiation]

The development of heterotopic ossification (HO) after total hip replacement or other surgical hip procedures can considerably impair the functional result and quality of life in up to 73% of all patients. Predisposing high risk factors for heterotopic ossification are severe pre-intra- and/or postoperative hip trauma, previous development of ipsi- and/or contralateral heterotopic ossification, hypertrophic osteoarthritis, active rheumatoid spondylarthritis as well as male sex. Over the past two decades a variety of surgical, pharmaceutical and radiotherapeutic prophylactic measurements have been proposed and tested in clinical trials. Since June 1988, we have treated 77 patients or 80 hips respectively with prophylactic irradiation. Individual risk factors included severe coxarthrosis grade IV, ipsi- or contralateral heterotopic ossification and severe hip trauma. As of July 1991 60 patients with a minimum follow-up of six months could be analyzed using clinical and radiological scoring systems. The patients had been prospectively randomized in two different treatment arms: 32 patients were treated with low dose (LD), five times 2 Gy daily fractions to a total dose of 10 Gy, whereas 28 patients were treated with high dose (HD), ten times 2 Gy (eight patients) or five times 3.5 Gy (20 patients). Operative procedures and individual risk factors were equally distributed in both groups. 23 patients (38% received indometacin three times 25 mg for six weeks, 19 patients (32%) diphosphonate EHDP 20 mg/kg body weight and 18 patients (30%) had no additional medication. 56/60 (93%) patients developed no significant heterotopic ossification and/or remained without impairment of their postoperative radiological and clinical hip status according to the applied Brooker and Harris Scores. Only 4/60 (7%) patients demonstrated treatment failures developing postoperative worsening one grade of Brooker score in two patients and two and three grades of Brooker score in the two others. Only 1/49 patients experienced a treatment failure, when radiotherapy had been initiated before and at postoperative day 4 compared to 3/11 patients initiated after postoperative day 4 (p less than 0.001). 3/32 patients (9.4%) in the LD group and 1/28 (3.6%) in the HD group were scored as treatment failures (nonsignificant). Radiotherapy treatment duration and additional medication had no impact on the outcome. In conclusion postoperative radiotherapy has shown high efficacy in prevention of heterotopic ossification as long as the treatment is initiated within the first four days after surgery. With respect to acute toxicity postoperative radiotherapy seems to be without any competition compared to surgical and pharmaceutical approaches including corticoid, diphosphonate and nonsteroid antiphlogistic drugs.

Etidronate for hypercalcemia of malignancy and osteoporosis

The biphosphonates are becoming well established as effective agents for the treatment of metabolic bone diseases. Etidronate disodium is the only biphosphonate approved by the U.S. Food and Drug Administration. Accepted indications for etidronate therapy are symptomatic Paget's disease, heterotopic ossification and hypercalcemia of malignancy. An unapproved, but apparently successful use is treatment of postmenopausal osteoporosis. Both oral and intravenous preparations are available. Newer biphosphonates, which may be more efficacious and less toxic than etidronate, are being studied.

[The importance of magnesium in orthopedics. VI. The importance of magnesium in the treatment of ectopic calcification and ossification]

In a five-year investigation the authors demonstrate their results with Mg treatment in 54 patients with ectopic calcifications and ossifications. Based on the results of experimental work, where the inhibiting action of Mg ions on calcium phosphate precipitation was proved in vitro as well as in vivo, the authors treated by means of local MgSO4 injections and oral administration of Mg lactate 17 patients with ossifying myositis, 16 with calcareal bursitis, 4 patients with paraosteoarthropathy of the elbow after craniocerebral injuries, 6 calcifications of the hip joint after operations and 5 calcifications in the insertions of tendons and ligaments. In all instances diminution to complete disappearance of the calcificates and ossificates was observed. The authors achieved also very favourable functional results. In the majority of patients the mobility in adjacent joints was restored. Clinical experience indicates that Mg prevents the development or suppresses further growth of ectopic calcifications and ossifications. During the formation of the ossificate, which is still immature, Mg causes diminution and sometimes complete absorption of the immature bone.

[Diphosphonates. Current trends and therapeutic prospects]

Diphosphonates are compounds characterized by a P-C-P bond. They are thus analogs of pyrophosphate and can be useful for treating several bone diseases. The authors synthetically review the mechanism of action of these drugs and their most important clinical applications. The authors finally mention the interesting therapeutic possibilities deriving from the development of new members of this class.

Indomethacin: an adjunct to surgical excision of immature heterotopic bone formation in a patient with a severe head injury. A case report

This case reports heterotopic ossification which produced ankylosis around the hip joint in a young adult treated with steroids for moderate cognitive defects secondary to brain trauma. It is associated with a high recurrence rate, especially if the bone is immature. The patient's heterotopic bone was surgically excised nine months post-injury, augmented with six weeks of indomethacin, and followed for three years.

Resection of heterotopic ossification and Didronel therapy--regaining wheelchair independence in the spinal cord injured patient

Ankylosis of the joints secondary to heterotopic ossification in the spinal cord injured is not uncommon. Five patients had ankylosis of the hip and knee joints which limited their ability to function in their wheelchairs. They underwent eight resections to improve their functional capabilities. All patients were treated pre- and postoperatively with disodium etidronate (EHDP, DIDRONEL). The average interval from injury to surgery was nine years nine months and the average interval from surgery to follow-up was two years three months. With clearly defined goals, proper patient selection, good pre- and postoperative management and intense rehabilitation combined with Didronel, optimum functional results were achieved.

Effects of ethylhydroxydiphosphonate (EHDP) on heterotopic ossification

The effect of EHDP medication was studied in 25 patients in whom heterotopic ossifications around the hip (19 cases) and elsewhere were resected. EHDP seemed to have a favorable effect on prevention of reossification and on function, particularly when ectopic ossifications were resected after total hip replacement. In all the patients, EHDP administration postponed mineralization of osteoid.

[Sternocostoclavicular hyperostosis: a report of nineteen cases with special reference to its etiology and treatment]

Nineteen patients with sternocostoclavicular hyperostosis were reviewed retrospectively. Of particular interest were their responses to antibiotics and prostaglandin inhibitors. The prostaglandin inhibitors relieved the pain within four weeks in 16 of 18 patients. In most cases, however, the inhibitors gradually became less effective. Oral antibiotics were more effective than the inhibitors in relieving the pain in 8 of 10 patients who were given antibiotics. Pustulosis palmaris et plantaris, commonly associated with sternocostoclavicular hyperostosis, diminished after antibiotic therapy as did the chest pain in most cases. The similarities between age and sex distribution, and the responses to antibiotics of the patients with sternocostoclavicular hyperostosis and those with pustulosis suggest that these disorders have a common etiology, and that the pustulosis may represent "bacterid reaction", and the hyperostosis may also be a manifestation of a systemic reaction to a focal infection.

Telogen effluvium: hair loss after spinal cord injury

A 26-year-old man sustained a C5 complete spinal cord injury (SCI) and displayed hysteric behavior which continued into the fourth month of hospitalization. Four months after injury, sudden loss of scalp hair was noted, consistent with psychogenic telogen effluvium. Other causes of hair loss were ruled out. During the sixth month, peak hair loss was noted over the back of the head. Four months after peak shedding, the loss of young club hairs was no longer observed. Recovery was complete seven months after peak loss, leaving a smaller permanent area of diffuse hair loss over the occiput. This pattern of hair loss has not been described previously in association with SCI.

Correlation between ossification and inflammation using a rat experimental model

In seronegative spondylarthropathies both inflammation and ossification can be demonstrated. Inflammation is a hallmark of diseases associated with antigen HLA-B27 in ankylosing spondylitis, Reiter's syndrome, and acute uveitis. Ossification is traditionally considered the end product of inflammation, but clinical examination does not show that this is always the case in man. The relationship between inflammation and ossification is not demonstrated in experiments on spinal involvement in adjuvant arthritis in the rat. Using that experimental model, we tested the efficacy of 3 nonsteroidal antiinflammatory drugs (indomethacin, naproxen, and phenylbutazone) given at dosages comparable to those employed in clinical practice, but at a lower level than those used by drug companies in animals. Results show that the drug exhibiting almost no antiinflammatory activity in the rat at the dosage used, phenylbutazone, was the most powerful inhibitor of ossification. Another mechanism of local osteogenesis must be sought to explain such a phenomenon.

Diphosphonate treatment for heterotopic ossification in spinal cord injury patients

Nine patients who had spinal cord injury and were receiving diphosphonate therapy for established neurogenic heterotopic ossification in 14 hips were followed up for an average of 14 months. Diphosphonate therapy at a dosage of 10 mg/kg/day when prescribed an average of 26 days after diagnosis did not prevent radiographically evident progression of heterotopic ossification. The interval of one to 30 days between clinical diagnosis and institution of diphosphonate treatment did not appear to affect the duration of radiographic progression or the final radiographic grade at maturity. Disodium etidronate therapy did not prevent the appearance of heterotopic ossification in three previously unaffected hips, although the final radiographic grade was mild. The radiographic progression of heterotopic ossification averaged 5.3 months. No clinically detectable side effects were attributable to the medication at the dosage prescribed after an average of 14 months of therapy. Due to the radiographic progression noted in patients who received 10 mg/kg/day, diphosphonate has been increased to dosages of 20 mg/kg for six months after early diagnosis.

The effect of indomethacin on para-articular ectopic ossification following total hip arthroplasty

Three patients exhibiting Grade III para-articular ectopic ossification following bilateral hip arthroplasty were successfully treated by excision of the bone and small-dose, short-term indomethacin therapy. Based on these results, a preliminary study was performed to determine the effect of indomethacin used prophylactically in patients who were predisposed to ectopic ossification and were undergoing total hip arthroplasty. Of a retrospective control group of 24 hips with extensive bilateral osteoarthritis, 63% were found to develop ectopic ossification following arthroplasty compared to 17% of a similar group treated with indomethacin (p less than 0.001). The ectopic ossification in the indomethacin-treated group possibly was of lesser severity (Grade I) than that encountered in the control group.

The effects of long-term administration of ethane-1-hydroxy-1, 1-diphosphonate on osteoarthrosis and heterotopic ossification in the mouse knee joint

Ethane-1-hydroxy-1, 1-diphosphonate (EHDP) was administered weekly for up to 15 months in either a high (50 mg/kg body weight) or low (5 mg/kg body weight) dose to the males of an inbred strain of mouse (SRT/ORT) which suffers from a high incidence of osteoarthrosis of the knee joint accompanied by extensive periarticular soft-tissue metaplasia forming cartilage and bone. The diphosphonate had two effects. In both doses it caused a reduction in the level of bone resorption. In high doses it caused a partial inhibition of mineralization resulting in the deposition of uncalcified osteoid. The diphosphonate did not influence the incidence or severity of the articular degeneration. The development of periarticular sort-tissue metaplasia was not halted by the EHDP although its form was slightly modified in the high dose. In both treated groups the proximal end of the tibia developed into an abnormal club shape as a result of interference with the normal turnover of bony spicules in the metaphyses. High-dose mice given 85Strontium as a tracer for calcium had much lower radioactivity in their bones than did the low dose and control mice.

Heterotopic ossification following hip replacement or spinal cord injury. Two clinical studies with EHDP

We report two double-blind, placebo-controlled studies of the effects of disodium etidronate (EHDP) on the incidence and severity of heterotopic ossification following total hip arthroplasty or spinal cord injury. The large placebo groups in these studies allowed the estimation of the incidence of heterotopic ossification in these patient populations. Heterotopic ossification occurred in 65% of patients after hip replacement and in the majority of these within 15 weeks. Clinically significant ossification occurred in 19% of affected patients. The incidence of heterotopic calcification after spinal cord injury was less (35%) but followed a similar natural history. Treatment with EHDP reduced the incidence and severity of lesions both at the time of stopping EHDP and up to 9 months after treatment.

Clinical features of 22 cases with "inter-sterno-costo-clavicular ossification". A new rheumatic syndrome

We present 22 cases with inter-sterno-costoclavicular ossification. Clinical and pathological findings show that abnormal ossification observed in this situation is due to non-suppurative chronic inflammation of the soft tissues around the sterno-costo-clavicular region such as the costo-clavicular ligament. We have classified X-ray findings into three stages according to the extent of the ossification; localized, generalized, and hyperostotic, and show that the disease progressed in this sequence. A considerable number of the patients showed abnormal X-ray findings in the spine or the sacro-iliac joint. Frequent association of pustulosis palmaris et plantaris was noted in this disease. Most of the cases were treated effectively with anti-inflammatory drugs, but a few cases required surgical resection of the ossified mass with the clavicle or the first rib in order to relieve the severe pain.