Objective To evaluate the incidence of heterotopic ossification (HO) after single-level Bryan cervical artificial disc replacement, and to identify the relationship between HO and the effectiveness. Methods The cl inical data of 48 patients undergoing single-level Bryan cervical artificial disc replacement between October 2005 and October 2007 were reviewedretrospectively. There were 27 males and 21 females with an average age of 40.5 years (range, 33-51 years), including 8 cases of cervical myelopathy, 27 cases of nerve root cervical spondylosis, and 13 cases of mixed cervical spondylosis with an average disease duration of 10.3 months (range, 2-14 months). The involved segments included C3, 4 in 3 cases, C4, 5 in 6 cases, C5, 6 in 30 cases, and C6, 7 in 9 cases. The outcomes were evaluated using Visual Analogue Scale (VAS) score, the neck disabil ity index (NDI), and cervical range of motion (ROM). According to patients with or without HO, 48 patients were divided into 2 groups (HO group and no HO group). VAS score, NDI, and cervical ROM were compared between 2 groups at 1, 2, 3, and 4 years after operation. Results No severe complication occurred during and after operation in all patients. Forty-eight patients were followed up 48-72 months (mean, 56.6 months). VAS score and NDI were significantly improved when compared with preoperative values at all time points (P lt; 0.05); except at 3 days after operation, no significant difference was found in cervical ROM at the other time points when compared with preoperation (P gt; 0.05). Thirteen patients (27.08%) had HO at 4 years after operation, including 8 cases of grade 1, 3 cases of grade 2, and 2 cases of grade 3. There was no significant difference in VAS score, NDI, and cervical ROM between 2 groups at 1, 2, 3, and 4 years (P gt; 0.05). Conclusion The incidence of HO after single-level Bryan cervical artificial disc replacement is relatively high. However, HO has no effect on the cervical ROM and the effectiveness.
Objective To review the research progress of heterotopic ossification (HO) pathogenesis.Methods Recent articles about HO including the risk factors and pathogenesis were reviewed and comprehensively analyzed. Results The pathogenesis of HO is not completely understood, but the extracellular factors, signaling pathways, and transcription factors in the pathogenesis of HO are understood deeply, such as bone morphogenic protein, Smad signaling, and core binding factor α1/runt-related transcription factor 2, which are probably involved in HO. Furthermore, some related microRNAs are also probably involved in HO. Conclusion The pathogenesis of HO should be further investigated so as to lay a foundation for preventing and treating HO.
Objective To review the basic research and cl inical progress of elbow heterotopic ossification after injury. Methods The recent l iterature concerning heterotopic ossification of the elbow was reviewed. Results Heterotopic ossification was caused by variety of stimul i and conditions. The current methods of prevention and treatment were to improve surgical techniques, to reduce trauma and bleeding, to rinse the area with bone fragments with plenty of salt water, and to use non-steroidal anti-inflammatory drugs. Conclusion Once heterotopic ossification occurred, surgical treatment is unique treatment method, so emphasis is to prevent heterotopic ossification.
Objective To compare heterotopic ossification between femoral head reconstruction and total hip arthroplasty(THA) in patients with ischemic necrosis of femoral head(INFH). Methods Between June 1994 and December 2004, the femoral heads were repaired in 1 005 patients with INFH,the total hip was replaced in 485 patients with INFH. The rate of heterotopic ossification was observed in 74 (Ficat Ⅲ to Ⅳ stages) of 1 005 patients and 80 of 485 patients given THA to compared the results of the two methods. Results These patients were followed up 2 to 10 years(6.5 years on average). The rates of heterotopic ossification were 5.4%(4/74) and 22.5%(18/80), respectively. There was statistically significant difference between two operative methods (Plt;0.01). Conclusion The rate of heterotopic ossification of femoral head reconstruction is lower than that of THA, so femoral head reconstruction is a better operative method for young patients and THA is suitable for old patients.
Objective To review the progress of the research on therelationship between the central nervous system injury and the heterotopic ossification. Methods The recent articles on the central nervous system injury and the heterotopic ossification were extensively reviewed, and the related clinical signs, symptoms, pathogenesis diagnosis, risk factors, prophylaxis, and treatment of the neurogenic heterotopic ossification were investigated. Results The possible mechanism for the neurogenic heterotopic ossification might involve the roles of thebone morphogenetic protein and the basic fibroblast growth factor, which were suggested as mediators in differentiation of the progenitor cells. Sonographic, serum creatine phosphokinase, and C-reactive protein were recommended as the useful screening tools for heterotopic ossification. Colchicine and rofecoxib could be used for the prophylaxis or treatment of heterotopic ossification. Conclusion The research on the neurogenic heterotopic ossification has achieved a great development but further studies in this field are still required.
ObjectiveTo compare the efficacy of selective cyclooxygenase 2 (COX2) inhibitor and non-selective COX2 inhibitor drugs in prevention of heterotopic ossification in rats model so as to provide reference for clinical drugs selection of heterotopic ossification prevention. MethodsFifty male Sprague Dawley rats, 6 to 8 weeks old, weight (190.0±8.5) g, were selected; the right Achilles tendon was cut off to induce ectopic bone formation. The rats were randomly divided into 5 groups (n=10):on the 1st day after modeling, celecoxib was given in groups A[2 mg/(kg·d)] and B[10 mg/(kg·d)], indomethacin in groups C[(2 mg/(kg·d) and D[10 mg/(kg·d)], and 2 mL of saline in group E for 10 weeks. The general condition of rats was observed after operation. At 5 and 10 weeks after operation, X-ray films of the right lower limb were taken to observe new bone formation. At 10 weeks after operation, the right Achilles tendon tissue was harvested for histological observation. Based on X-ray and histological results, heterotopic ossification was assessed. Immunohistochemical staining was used to evaluate COX2 and bone morphogenetic protein 2 (BMP-2) expression levels in local Achilles tendon. ResultsDuring the experiment, 5 rats died (2 in group B, 1 in group C, and 2 in group D), the other rats survived to the end of the experiment. General observation of Achilles tendon tissue showed that the tendon tissue volume of group B was the smallest, with soft texture and no cartilage-like tissue; the tendon tissue volume of group E was the biggest, with hard texture and cartilage-like tissue. The incidence of heterotopic ossification was 80.0% (8/10), 25.0% (2/8), 88.9% (8/9), 50.0% (4/8), and 100% (10/10) in groups A-E respectively at 10 weeks after operation; significant differences were found between groups B, D and group E (P=0.002,P=0.023) and between groups B and C (P=0.015), but no significant difference was found among the other groups (P>0.05). COX2 expression level in groups B and D was significantly lower than that in group E (P<0.05), but no significant difference was found among the other groups (P>0.05); BMP-2 expression level in group B was significantly lower than that in groups A, C, and E (P<0.05), but no significant difference was found among the other groups (P>0.05). ConclusionCelecoxib at a dose of 10 mg/(kg·d) can effectively reduce the incidence of heterotopic ossification in rats.
ObjectiveTo explore the value of matrix metalloproteinase 9 (MMP-9) in predicting the occurrence of heterotopic ossification by observing the expression of MMP-9 in heterotopic ossification of the early trauma rat model. MethodsA total of 132 male Sprague Dawley rats, aged 4-5 weeks, weighing (135.0±6.5) g, were randomly divided into experimental group and control group (n=66). In experimental group, the Achilles tendon was cut off and clamped to prepare heterotopic ossification model; in control group, only Achilles tendon was exposed by making a incision. The general condition of the rats was observed after operation; at 2, 3, 4, 5, 6, 7, and 8 days after operation, the Achilles tendon tissue was harvested for gross observation, histological observation, and immunohistochemical staining observation; the serum and Achilles tendon tissue were harvested to detect the expressions of MMP-9 protein and mRNA by ELISA and RT-PCR. The X-ray films at 5 and 10 weeks and histological examination at 10 weeks after operation were used to observe heterotopic ossification. ResultsAll rats survived to the end of the experiment. The Achilles tendon had no significant change in control group at each time point, showing normal tendon structure. In experimental group, the hardness of Achilles tendon tissue gradually increased with the time; there were a large number of irregular connective tissue and cartilage cells; and immunohistochemical staining for MMP-9 was positive results. The MMP-9 protein and mRNA expression levels of experimental group were significantly higher than those of the control group at each time point (P < 0.05). MMP-9 protein and mRNA expression levels of experimental group showed an increasing tendency (P < 0.05). According to the results of X-ray films and histological observation, heterotopic ossification occurred at 10 weeks after operation in experimental group, but no heterotopic ossification was observed in control group. ConclusionIn early heterotopic ossification of rat Achilles tendon, the expression of MMP-9 increases significantly, indicating that it has reference significance in predicting heterotopic ossification.
ObjectiveTo summarize the research progress of heterotopic ossification of the elbow joint after trauma. MethodsThe recent domestic and foreign literature concerning heterotopic ossification of the elbow joint after trauma was analysed and summarized. ResultsThe mechanism of heterotopic ossification of the elbow joint after trauma is mainly related to bone morphogenetic protein signal transduction disorder. Now there are many treatments of heterotopic ossification, including non-surgical treatment, prevention, and surgical treatment. Non-surgical treatment and prevention mainly aim at patients who have no elbow heterotopic ossification or who have mild limited elbow motion because of elbow heterotopic ossification after trauma, including drug therapy, radiation therapy, Chinese medicine therapy, and rehabilitation treatment. For patients with invalid non-surgical treatment, choosing surgical treatment is a must. Surgical treatment includes surgical resection, arthroscopic resection, and joint replacement, priority should be given first to surgical resection. ConclusionHeterotopic ossification of the elbow joint is common and there is not a recognized standard treatment, comprehensive use of non-surgical treatment and surgical treatment is the future direction.
ObjectiveTo explore the role and significance of hypoxia inducible factor lα (HIF-lα) and hypoxia microenvironment in the pathogenesis of post-traumatic heterotopic ossification by detecting the expression of HIF-lα in rat model of heterotopic ossification after Achilles tenotomy. MethodsA total of 140 male Sprague Dawley rats, aged 8-10 weeks, and weighing (210.1±10.6) g, were randomly divided into experimental group (n=70) and control group (n=70). In experimental group, the Achilles tendon was cut off and clamped to prepare post-traumatic heterotopic ossification model; in control group, only Achilles tendon was exposed. The general condition of rats was observed after operation, and at 2, 3, 4, 5, 6, 7, 8, 10, 12, and 14 days after operation, the Achilles tendon tissue was harvested from 6 rats for gross observation, histological observation, and immunohistochemical staining observation, and real-time fluorescence quantitative PCR and Western blot were used to detect the expressions of HIF-lα gene and protein at different time points in 2 groups. The X-ray films were taken and histological examination was done at 10 weeks after operation to evaluate the formation of heterotopic ossification. ResultsDuring the experiment, 1 rat died in experimental group at 3 days after operation, and the other rats survived to the end of the experiment. Gross and histological staining showed that the Achilles tendon had no obvious change, with normal tendon structure in control group at each time point. In experimental group, atrophy and necrosis of Achilles tendon stump were observed, with infiltration of inflammatory cells; and the hardness of Achilles tendon tissue gradually increased with the time; there were a large number of irregular connective tissue and cartilage cells. When compared with control group, the HIF-lα mRNA and protein expressions were significantly increased in experimental group at each time point (P < 0.05). Immunohistochemical staining showed that HIF-lα was positive in experimental group. According to the results of X-ray films and histological examination at 10 weeks after operation, heterotopic ossification was found in experimental group, but no heterotopic ossification in control group. ConclusionThe expression of HIF-lα significantly increases at early stage of post-traumatic heterotopic ossification after Achilles tenotomy, suggesting that the local hypoxia microenvironment plays an important role in the pathogenesis of heterotopic ossification.
ObjectiveTo evaluate the mid-term clinical and radiological results of dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease in Chinese population.MethodsBetween April 2010 and June 2011, 25 patients with single-segmental degenerative cervical disc disease underwent DCI replacement. Visual Analogue Scale (VAS), Japanese Orthopaedic Association (JOA) scores, Neck Disability Index (NDI) and 36-Item Short Form Health Survey Questionnaires (SF-36) were used for evaluation of neurological function and pain severity, before and after operation, and during follow-up period. Radiographic evaluation included range of motion (ROM) of C2–7, surgical segments and adjacent level, intervertebral height of the surgical segments, migration, subsidence of the implant and heterotopic ossification (HO).ResultsThe mean follow-up period was 72.3 months (ranged from 68 to 78 months). The VAS, JOA, NDI, and SF-36 mental and physical component summaries improved significantly after surgery (P<0.05) and remained stable over the whole observation period. The ROM (flexion/extension) and intervertebral height at the level treated with DCI remained at the first 2 years and partly reduced at the final follow-up. ROM for C2–7 and adjacent levels maintained during the follow-up period. DCI subsidence was observed in 11 segements, and 9 segements appeared heterotopic ossification.ConclusionsClinical efficacy of DCI arthroplasty improves and maintaines during the mid-to-long period of follow-up. HO formation is a common phenomenon, leading a dramatic decrease of ROM at index level and recurrence of neurological symptoms. Rate of implant subsidence and migration is relatively high, leaving a potential risk of symptom at index level and adjacent segment degeneration. It suggests that for patients with degenerative cervical disc disease, total disc replacement or anterior cervical discectomy and fusion is still the first choice instead of DCI arthroplasty.