Mineral and Bone Consequences of High Dose Denosumab Therapy to Treat an Aneurysmal Bone Cyst, a Child Case Report.

Aneurysmal bone cysts (ABCs) are rare benign pseudotumoral bone lesions with potential aggressive behavior due to the extensive destruction of surrounding bone. Traditionally, these tumors were treated with open surgery, but there is more and more a shift to less invasive procedures. In particular, treatment for spinal ABCs is generally unsatisfactory due to the risk of morbidity, neurological impairment and recurrence, and there is a need for innovative therapies. Denosumab has been reported as a useful treatment in giant cell tumors of bone (GCTB), so its efficacy has been tested also in other fibro-osseus lesions affecting children and adolescents, such as spinal aneurysmal bone cysts. The pediatric literature is limited to case reports and small series, all of which highlight the efficacy of this treatment on lesions growth and associated bone pain. Some of these reports have already reported well known side effects associated with denosumab, such as hypocalcemia at the beginning of the treatment, and rebound hypercalcemia at the discontinuation. The latter seems to be more frequent in children and adolescents than in adults, probably due to the higher baseline bone turnover in children. In addition, the use of denosumab in young patients could affect both bone modeling and remodeling, even if the consequences on the growing skeleton have not been reported in detail. Here we describe the case of a spinal ABC diagnosed in an 8-year old young boy which was not accessible to surgery but responded favorably to denosumab. Our aim is to describe the rapid changes in mineral and bone homeostasis in this patient, that required advice from the experts of the European Reference Network (ERN) for rare bone and endocrine diseases.

A patient with extensive cerebral calcification due to pseudohypoparathyroidism: a case report.

BACKGROUND: Pseudohypoparathyroidism(PHP) is a heterogeneous group of disorders due to impaired activation of c AMP dependant pathways following binding of parathyroid hormone (PTH) to its receptor. In PHP end organ resistance to PTH results in hypocalcaemia, hyperphosphataemia and high PTH levels. CASE PRESENTATION: A 59 year old male presented with a history of progressive impairment of speech and unsteadiness of gait for 1 week and acute onset altered behavior for 1 day and one episode of generalized seizure. His muscle power was grade four according to MRC (medical research council) scale in all limbs and Chovstek's and Trousseau's signs were positive. Urgent non contrast computed tomography scan of the brain revealed extensive bilateral cerebral and cerebellar calcifications. A markedly low ionized calcium level of 0.5 mmol/l, an elevated phosphate level of 9.5 mg/dl (reference range: 2.7-4.5 mg/dl) and an elevated intact PTH of 76.3 pg/l were noted. His renal functions were normal. His hypocalcemia was accentuated by the presence of hypomagnesaemia. His 25 hydroxy vitamin D level was only marginally low which could not account for severe hypocalcaemia. A diagnosis of pseudohypoparathyroidism without phenotypic defects, was made due to hypocalcaemia and increased parathyroid hormone levels with cerebral calcifications. The patient was treated initially with parenteral calcium which was later converted to oral calcium supplements. His coexisting Vitamin D deficiency was corrected with 1αcholecalciferol escalating doses. His hypomagnesaemia was corrected with magnesium sulphate parenteral infusions initially and later with oral preparations. With treatment there was a significant clinical and biochemical response. CONCLUSION: Pseudohypoparathyroidism can present for the first time in elderly resulting in extensive cerebral calcifications. Identification and early correction of the deficit will result in both symptomatic and biochemical response.

Ozonoterapia paravertebral en la patología de la columna vertebral lumbar / Terapia ozônio paravertebral na patologia da coluna lombar / Paravertebral ozone therapy in the pathology of the lumbar spine

Introducción: la búsqueda de alternativas terapéuticas para la atención al paciente con patología de la columna vertebral es una exigencia social, para lo cual se promueve el uso de la ozonoterapia. Objetivo: caracterizar la respuesta clínica de los pacientes con patología de la columna vertebral tratados con ozonoterapia paravertebral en el Hospital General Docente Dr Agostinho Neto de Guantánamo durante el período comprendido entre los meses de septiembre de 2017 y agosto de 2018. Método: se realizó un estudio observacional, prospectivo y transversal en el servicio de Neurocirugía en 78 pacientes con enfermedades de la columna vertebral, seleccionados intencionalmente y que participaron conscientemente en un preexperimento que consistió en la aplicación de un ciclo de diez sesiones de ozonoterapia por vía paravertebral durante un periodo de dos semanas. Se controlaron las siguientes variables: intensidad del dolor lumbar medida mediante la escala de evaluación analógica; incapacidad funcional evaluada mediante la escala de Oswestry. Resultados. la mayoría de los pacientes transitó a una categoría de dolor inferior y el 80,7 % se evaluó en la categoría leve­moderado después de la ozonoterapia. Esta posibilitó que en el mayor porcentaje disminuyera el grado de incapacidad funcional y la proporción con un grado mínimo de incapacidad función se incrementara en un 46,0 %. Conclusiones: la ozonoterapia paravertebral constituye una alternativa que puede ayudar en el tratamiento conservador del paciente con patología vertebral(AU)

Introduction: the search for therapeutic alternatives for patient care with pathology of the spine is a social requirement, for which the use of ozone therapy is promoted. Objective: to characterize the clinical response of patients with spinal pathologies treated with paravertebral ozone therapy at the Dr Agostinho Neto Guantanamo General Teaching Hospital during the period between September 2017 and August 2018. Method: a observational, prospective and cross-sectional study in the Neurosurgery service in 78 patients with diseases of the spine, intentionally selected and consciously involved in a preexperiment that consisted in the application of a cycle of ten sessions of ozone therapy by paravertebral route, during a period two weeks The following variables were controlled: lumbar pain intensity measured by the analogical evaluation scale; functional disability assessed by the Oswestry scale. Results: the majority of patients went to a lower pain category and 80.7% were evaluated in the mild-moderate category after ozone therapy. This made it possible for the highest percentage to decrease the degree of functional disability and the proportion with a minimum degree of disability function increased by 46.0%. Conclusions: Paravertebral ozone therapy is an alternative that can help in the conservative treatment of patients with vertebral pathology(AU)

Introdução: a busca de alternativas terapêuticas para o cuidado do paciente com patologia da coluna vertebral é uma exigência social, para a qual o uso da ozonioterapia é promovido. Objectivo: para caracterizar a resposta clínica de pacientes com patologia vertebral tratados com terapia de ozono paravertebral no Agostinho Neto Geral Teaching Hospital Dr Guantánamo durante o período de setembro 2017 a Agosto de 2018. Método: foi realizado um estudo de observação, em perspectiva e em corte transversal, no departamento de neurocirurgia em 78 pacientes com doenças da coluna vertebral, seleccionados intencionalmente e conscientemente participaram num preexperimento que consistia na aplicação de um ciclo de dez sessões de terapia de ozono através paravertebral, ao longo de um período duas semanas As seguintes variáveis foram controladas: intensidade da dor lombar medida pela escala de avaliação analógica; incapacidade funcional avaliada pela escala de Oswestry. Resultados: a maioria dos pacientes foi para uma categoria de dor mais baixa e 80,7% foram avaliados na categoria leve-moderada após a terapia com ozônio. Isso permitiu que o maior percentual diminuísse o grau de incapacidade funcional e a proporção com um grau mínimo de incapacidade aumentasse 46,0%. Conclusões: A terapia com ozônio paravertebral é uma alternativa que pode ajudar no tratamento conservador de pacientes com patologia vertebral(AU)

The Effects of Local Anesthesia Administration on Pain Experience During Interventional Spine Procedures: A Prospective Controlled Trial.

OBJECTIVE: It has been postulated that local anesthetic administration may be the most painful part of interventional spine procedures. Despite this, there is a lack of evidence supporting the commonly used traditional technique of anesthetic delivery as part of these procedures. This study tested three hypotheses: 1) alternative method of local anesthesia injection is superior to the traditional method; 2) using the traditional method of injection is not superior to using no local anesthetic; and 3) treatment needle size, anesthetic injection technique, and sedation are associated with pain experienced during procedures. DESIGN: Prospective, multicenter clinical trial of 127 participants who underwent elective bilateral symmetric interventional spine procedures in outpatient spine clinics. METHODS: Primary outcomes were pain scores during and after procedures to examine the influence of anesthetic injection method and treatment needle gauge on pain experience using linear mixed model regression analysis. A post-hoc comparison of estimated marginal mean pain scores was completed on both anesthetic injection method and treatment needle gauge. CONCLUSIONS: The alternative method was superior (P < 0.05) to the traditional method on post procedural pain scores. Injecting local anesthetic with the traditional or alternative method was not superior to using no local anesthetic. Treatment needle size, pain at one inch of treatment needle insertion, and baseline pain were all significantly (P < 0.05) associated with overall procedural pain. Further studies are needed optimize and justify local anesthetic injections for these procedures.

Efficiency of Hyperbaric Oxygen Therapy in Iatrogenic Spinal Infections.

STUDY DESIGN: Retrospective clinical study. OBJECTIVE: The aim of this study is to reveal the effectiveness of HBO therapy in iatrogenic spinal infections intractable to antibiotic therapy alone. SUMMARY OF BACKGROUND DATA: The efficiency of hyperbaric oxygen (HBO) therapy, which is currently being used in many areas, has been proven in infections in deep and superficial locations and in osteomyelitis. The aim of this study is to reveal effectives of HBO therapy in iatrogenic spinal infections intractable to antibiotic alone therapy. METHODS: HBO therapy was given to 19 cases of iatrogenic spinal infection between 2008 and 2013. Adjuvant HBO therapy was applied to cases that had exhibited no improvement in clinical and laboratory findings despite medical treatment for at least 3 weeks. Several parameters including demographic characteristics, surgical area, etiology and the surgical treatment modality, microbiology (culture material and causative organism), clinical and laboratory results, duration of HBO therapy, and outcome were reviewed. RESULTS: The mean age was 54.6 years (range: 32-75 years). Iatrogenic spinal infections were most frequent in the lumbar region. It occurred after spine instrumentation in 12 cases and after micro-discectomy in 7 cases. The average number of HBO therapy sessions applied was 20.1 (range: 10-40). Wound discharge and clinical and laboratory findings recovered in all cases at the end of the therapy course. No revision or removal of the instrumentation was necessary in the instrumented cases. CONCLUSION: HBO therapy is a treatment modality, which is safe and efficient as an adjuvant therapy in the treatment of infections. It was also seen to be effective in the prevention of revision procedures and instrumentation failures in iatrogenic osteomyelitis cases, which had occurred following spinal instrumentation. LEVEL OF EVIDENCE: 4.

Fluoroscopy-guided infiltration for pain reduction in patients with Baastrup's disease: clinical experience and results.

OBJECTIVE: Baastrup disease refers to degenerative changes of adjacent spinous processes with resultant back pain. The purpose of this study is to assess the safety and efficacy of percutaneous, fluoroscopy-guided infiltrations in a consecutive series of patients suffering from Baastrup disease. MATERIALS AND METHODS: From January 2009 until December 2013, 55 patients suffering from Baastrup disease (diagnosed clinically and by imaging findings) underwent percutaneous, fluoroscopy-guided infiltration. The position of the needle (22-gauge spinal needle) was fluoroscopically verified at the level of interspinous ligament. Then a mixture of long-acting corticosteroid with local anesthetic (1.5/1 cc) was injected. A questionnaire with NVS scale helped in assessing pain relief degree, life quality, and mobility improvement. RESULTS: In the patients of our study, a total of 67 sessions was performed. In 12/55 patients (22%), a second infiltration was performed within 7-10 days apart from the first one. The end point was 1 year post-treatment. Patients were followed 1 week after the first injection for a subsequent treatment and then if asymptomatic re-controlled in 3-6 and 12 months. Comparing the pain scores prior (mean value, 8.18 ± 1.44 NVS units) and after (mean value, 0.62 ± 0.93 NVS units) there was a mean decrease of 7.56 ± 1.68 NVS units (p < 0.001) on terms of pain reduction, effect upon mobility and life quality. There were no clinically significant complications noted in our study. CONCLUSIONS: Fluoroscopy-guided infiltrations seem to be a feasible, efficacious, and safe approach for pain reduction and mobility improvement in patients with Baastrup disease.

Oxygen-ozone therapy for degenerative spine disease in the elderly: a prospective study.

We describe our experience of oxygen-ozone therapy to treat degenerative spine disease in the elderly. From April 2004 to March 2008 we selected 129 patients with CT and/or MR evidence of spondyloarthrosis and disc degeneration of the lumbar spine. All patients enrolled in the study had contraindications to the administration of commonly used analgesic and anti-inflammatory drugs.Oxygen-ozone therapy was given by CT-guided intraforaminal injection as the first treatment followed by 4 weekly paralumbar infiltrations on an outpatient basis. The full treatment lasted a month. Clinical outcome was assessed 3 months and 1 year after treatment. The good results obtained indicate that oxygen-ozone therapy is an ideal treatment with no side-effects in elderly patients with degenerative spine disease.

Refractory vertebral osteomyelitis due to CTX-M-14-producing Escherichia coli at ertapenem treatment in a patient with a coexisting urinary tract infection caused by the same pathogen.

We report the case of a patient with vertebral osteomyelitis and concurrent urinary tract infection (UTI) in which extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (EC(1)) isolated from urine culture was ciprofloxacin-resistant and ertapenem/imipenem-susceptible. The empirically used oral form of ciprofloxacin was switched to parenteral ertapenem based on the antimicrobial susceptibility. However, vertebral osteomyelitis deteriorated, and despite the disappearance of pyuria and a negative urine culture, ESBL-producing E. coli was isolated from a biopsy of the bony material from the fifth lumbar vertebra (EC(2)) and blood culture (EC(3)) at 10 and 12 days after starting ertapenem, respectively. Ertapenem was switched to imipenem, and defervescence occurred 2 days later; a subsequent blood culture was negative. Genotyping indicated that EC(1), EC(2), and EC(3) were of the same clone, with the ESBL being CTX-M-14. The tested antibiotics had identical minimum inhibitory concentrations against each of these isolates. From the pharmacokinetics/pharmacodynamics points of view, it is reasonable to attribute the ertapenem treatment failure in vertebral osteomyelitis due to ESBL-producing E. coli in this case to the suboptimal ertapenem concentration in the inflammatory bone tissue of the host.

[Botulinum toxin A (BTX-A) point injection for treatment of the third lumbar transverse process syndrome].

OBJECTIVE: To observe clinical therapeutic effect of acupoint injection of botulinum toxin type A (BTX-A) on the third lumbar transverse process syndrome. METHODS: Twenty-five cases of the third lumbar transverse process syndrome were randomly divided into 2 groups, an acupoint-injection group (n=10) and an acupuncture group (n=15). The acupoint-injection group were treated with acupoint injection of BTX-A into tender points at the third lumbar transverse process or surrounding acupoints, and the acupuncture group were treated with acupuncture at the same points as in the acupoint-injection group. Two months later, their therapeutic effects and the time of producing the effect were compared between the two groups. RESULTS: The cured rate and the time of producing the effect were 50.0% and (3.75+/-1.65) days in the acupoint-injection group, and 0, (12.47+/-5.33) days in the acupuncture group, respectively, the former being better than the latter (P<0.05). CONCLUSION: The clinical therapeutic effect of injection of BTX-A on the third lumbar transverse process syndrome is better than that of simple acupuncture.

Current therapeutic strategy in spinal brucellosis.

Brucellosis is a systemic disease and may affect many organ systems. However, musculoskeletal involvement represents 10-85% of the focal complications. Involvement of the spine is one of the most common localized forms of human brucellosis, especially in elderly patients. It is a destructive disease that requires a correct and early diagnosis, and immediate treatment. However, controversy remains over the optimal duration and antimicrobial regimen required for the treatment of spinal brucellosis. Relapses and sequelae are still reported. In recent years, in order to improve outcomes, alternative regimens have been investigated. However, the classical regimen (doxycycline, 100mg twice daily, for at least 12 weeks combined with streptomycin, 1g daily, for the first 2 or 3 weeks) remains the first choice of antibiotic therapy. Alternative therapies (rifampin, fluoroquinolones, co-trimoxazole) should be considered when adverse reactions or contraindications to the above drugs (ototoxicity, nephrotoxicity, pregnancy, etc.) are reported.

[Efficiency of short courses of physiotherapy with the use of energy metabolism regulators in patients with dorsopathy].

The assessment of procedure tolerance, their efficiency at shortening of courses of dorsopathies physiotherapy to 12-14 days made possible to detect presence of unfavorable reactions to treatment in 32% of cases. Regulator of energy metabolism, included in the therapy, assists to good tolerance to shortened courses of dorsopathy rehabilitation (frequency of presence and expression degree of reaction to treatment reduced to 15%), stabilization of energy system in patients' organism, absence of hyper activation and stress of adaptive mechanisms, maintenance of compensatory abilities reserves.

Treatment of haematogenous pyogenic vertebral osteomyelitis by single-stage anterior debridement, grafting of the defect and posterior instrumentation.

Anterior debridement, grafting of the defect and posterior instrumentation as a single-stage procedure is a controversial method of managing pyogenic vertebral osteomyelitis. Between 1994 and 2005, 37 patients underwent this procedure at our hospital, of which two died and three had inadequate follow-up. The remaining 32 were reviewed for a mean of 36 months (12 to 66). Their mean age was 48 years (17 to 68). A significant pre-operative neurological deficit was present in 13 patients (41%). The mean duration of surgery was 285 minutes (240 to 360) and the mean blood loss was 900 ml (300 to 1600). Pyogenic organisms were isolated in 21 patients (66%). All patients began to mobilise on the second post-operative day. The mean hospital stay was 13.6 days (10 to 20). Appropriate antibiotics were administered for 10 to 12 weeks. Early wound infection occurred in four patients (12.5%), and late infection in two (6.3%). At final follow-up, the infection had resolved in all patients, neurological recovery was seen in ten of 13 (76.9%) and interbody fusion had occurred in 30 (94%). The clinical outcome was excellent or good in 30 patients according to Macnab's criteria. This surgical protocol can be used to good effect in patients with pyogenic vertebral osteomyelitis when combined with appropriate antibiotic therapy.

Electro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog.

A non-ambulatory dog with tetraparesis following a pain episode that had evolved over 2 months was submitted for medical treatment and diagnosed with intervertebral disk disease at C3-C4 and dorsal extradural compression at C1-C2 and C3-C4 using myelography and computed tomography. The dog experienced ambulation recovery after 15 days of treatment with only electroacupuncture and Chinese herbal medicine, with marked improvement occurring after only 10 treatments. Six months of followup demonstrated that the dog was stable and had no recurrence of symptoms. Therefore, it was concluded that the combination of electroacupuncture and Chinese herbal medicine was responsible for motor rehabilitation.

Electro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog

A non-ambulatory dog with tetraparesis following a pain episode that had evolved over 2 months was submitted for medical treatment and diagnosed with intervertebral disk disease at C3-C4 and dorsal extradural compression at C1-C2 and C3-C4 using myelography and computed tomography. The dog experienced ambulation recovery after 15 days of treatment with only electroacupuncture and Chinese herbal medicine, with marked improvement occurring after only 10 treatments. Six months of followup demonstrated that the dog was stable and had no recurrence of symptoms. Therefore, it was concluded that the combination of electroacupuncture and Chinese herbal medicine was responsible for motor rehabilitation.

Nonsurgical management of low back pain and lumbar disk degeneration.

Lumbar disk degeneration is a ubiquitous and complex phenomenon. The etiology varies widely and may be dificult to identify. Many techniques have been proposed to manage the pain and disability resulting from disk degeneration. Medicines, bed rest, orthotics, physical therapy, chiropractics, selective injections, and intradiskal electrothermal therapy have been used. Some of these therapies have been more successful than others, but most have at least some role in the current techniques of helping patients deal with this syndrome. How best to use these tools in conjunction with patient education is critical to success.

Alendronate, vitamin D, and calcium for the treatment of osteopenia/osteoporosis associated with HIV infection.

BACKGROUND: Osteopenia and osteoporosis are frequent complications of HIV infection and/or its treatment. Alendronate is the only bisphosphonate approved for the treatment of osteoporosis in men and women. We conducted a 48-week prospective, randomized, open-label study to evaluate the effects of alendronate, vitamin D, and calcium supplementation on bone mineral density (BMD) in patients with HIV infection. METHODS: Thirty-one HIV-infected subjects with lumbar spine BMD t-scores less than -1.0 on antiretroviral therapy for a minimum of 6 months were randomized to receive (n = 15) or not to receive (n = 16) 70 mg of alendronate weekly for 48 weeks. All subjects received calcium (1000 mg daily as calcium carbonate) and vitamin D supplementation (400 IU daily). The study was powered to detect 3% changes in BMD in the lumbar spine within arms at 48 weeks. RESULTS: Thirty-one patients were enrolled; most were male, with an average length of HIV infection of 8 years. Eighty-four percent had an HIV RNA load below 400 copies/mL, with a current median CD4+ T-cell count of 561 cells/mm3 (median nadir CD4 cell count of 167 cells/mm). At baseline, the median t-score in the lumbar spine was -1.52 and the median t-score in the hip was -1.02. Alendronate in combination with vitamin D and calcium increased lumbar spine BMD by 5.2% (95% confidence interval [CI]: 1.3-6.4) at 48 weeks compared with an increase of 1.3% (95% CI: -2.4 to 4.0) in subjects receiving vitamin D and calcium alone. One subject discontinued treatment in each arm. There were no serious adverse events. CONCLUSIONS: Alendronate, vitamin D, and calcium are safe and potentially useful in the treatment of osteopenia/osteoporosis associated with HIV infection.

Retrospective case series on patients with chronic spinal pain treated with dextrose prolotherapy.

OBJECTIVES: To determine the clinical benefits of dextrose prolotherapy in patients with chronic spinal pain. DESIGN: Retrospective case series. SETTING/LOCATION: During the first 2 years at an outpatient prolotherapy clinic. SUBJECTS: One hundred and seventy-seven (177) consecutive patients with a history of chronic spinal pain completed prolotherapy treatment and were followed for a period ranging from 2 months to 2.5 years. INTERVENTIONS: Patients were treated with a proliferant solution containing 20% dextrose and 0.75% xylocaine. One half milliliter (0.5 mL) of proliferant was injected into the facet capsules of the cervical, thoracic, and lumbar spine, or combinations of the three areas. The iliolumbar and dorsal sacroiliac ligaments were also injected in patient with low back pain. Injections were typically done on a weekly basis for up to 3 weeks. A set of three injections was repeated in 1 month's time if needed. OUTCOME MEASURES: Level of pain, and improvement in activities of daily living were measured on a five-point scale. Improvement in ability to work was also assessed. RESULTS: Ninety-one percent (91.0%) of patients reported reduction in level of pain; 84.8% of patients reported improvement in activities of daily living, and 84.3% reported an improvement in ability to work. Women required on average, three more injections than men. Cervical spine response rates were lower than thoracic or lumbar spine. No complications from treatment were noted. CONCLUSIONS: Dextrose prolotherapy appears to be a safe and effective method for treating chronic spinal pain that merits further investigation. Future studies need to consider differences in gender response rates.

Development of a New Zealand white rabbit model of spinal pseudarthrosis repair and evaluation of the potential role of OP-1 to overcome pseudarthrosis.

STUDY DESIGN: Posterolateral lumbar fusions were performed in nicotine-exposed, New Zealand white rabbits. Animals that developed a pseudarthrosis were then regrafted with no graft, autograft, or osteogenic protein-1 (OP-1). OBJECTIVES: To establish a model of pseudarthrosis repair and to evaluate the ability of OP-1 to induce fusion in this model. SUMMARY OF BACKGROUND DATA: OP-1 has been shown to have a 100% fusion rate in an established rabbit fusion model, even in the presence of nicotine, which is known to inhibit fusion. METHODS: Forty-four New Zealand white rabbits underwent posterolateral lumbar fusion with iliac crest autograft. To maximize the incidence of pseudarthroses, nicotine was administered to all rabbits. At 5 weeks, the spines were explored, and all pseudarthroses were redecorticated and grafted with no graft, autograft, or OP-1. At 10 weeks, the rabbits were killed and fusions masses were assessed with manual palpation, radiography, computed tomography, and/or histology. RESULTS: Nine rabbits (20%) were lost to complications. Thirty-four (94%) had pseudarthroses on exploration at 5 weeks. By manual palpation at 10 weeks, 1 of 10 (10%) pseudarthroses that received no graft fused, 5 of 12 (42%) pseudarthroses that received autograft fused, and 9 of 11 (82%) pseudarthroses that received OP-1 fused. Computed tomography and histology further characterized the fusion masses. CONCLUSIONS: This study establishes a model for treatment of pseudarthroses. OP-1, which has previously been shown to have 100% fusion rate in animal models, outperformed autograft and induced fusion in 82% of rabbits.