Background The optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM) has not been defined, and the relative merits of multilevel anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy (2-level or skip 1-level corpectomy) and fusion (ACCF) remain controversial. However, few comparative studies have been conducted on these two surgical approaches. Methods This study retrospectively reviewed the case histories of 120 patients that underwent surgical treatment for 3-or 4-level CSM from July 2003 to June 2008. One hundred and twenty patients (81 male and 39 female) of mean age 58.3 ± 9.8 years (37-78) were included. The study compared perioperative parameters (blood loss, operation times), complications [surgery-related complications (CSF, hoarseness, epidural hematoma, C5-palsy, dysphagia), instrumentation and graft related complications (dislodgement, subsidence)], clinical parameters [Japanese Orthopedic Association (JOA) scores, Neck Dysfunciton Index (NDI) scores], and radiologic parameters (segmental lordosis, fusion rate). Results At a minimum of 2-year follow-up, both ACDF and ACCF groups demonstrated a significant increase in the JOA scores (preoperatively 9.25 ± 1.9 and 8.86 ± 1.9, postoperatively 13.86 ± 1.6 and 13.27 ± 1.8, respectively), segmental lordosis (preoperatively 9.79 ± 3.4 and 9.54 ± 3.0, postoperatively 17.75 ± 2.6 and 14.49 ± 2.5, respectively) and NDI scores (preoperatively 12.56 ± 3.0 and 12.21 ± 3.4, postoperatively 3.44 ± 1.7 and 5.68 ± 2.6, respectively). Six patients (2 dislodgement, 4 subsidence) in ACCF group had instrumentation and graft related-complications and they had no obvious neurological symptoms without a second operation. Blood loss (102.81 ± 51.3 and 149.05 ± 74, respectively, P = 0.000), NDI scores (P = 0.000), and instrumentation and graft related-complications (P = 0.032) were significantly lower in the ACDF group, whereas operation time (138.07 ± 30.9 and 125.08 ± 26.4, respectively, P = 0.021) and segmental lordosis (P = 0.000) were significantly greater in the ACDF group. Other parameters were not significantly different in the two groups. Conclusions Surgical managements of 3-or 4-level CSM by ACDF or ACCF showed no significant differences in terms of achieved clinical symptom improvements, with the exception of better postoperative NDI scores in ACDF. In addition, ACDF is better than ACCF in terms of blood loss, lordotic curvature improvement and instrumentation and graft related-complication rates, with the exception of operation times.

To understand the prevalence of Cryptosporidium infection in rodents in China and to assess the potential role of rodents as a source for human cryptosporidiosis, 723 specimens from 18 rodent species were collected from four provinces of China and examined between August 2007 and December 2008 by microscopy after using Sheather's sugar flotation and modified acid-fast staining. Cryptosporidium oocysts were detected in 83 specimens, with an overall prevalence of 11.5%. Phodopus sungorus, Phodopus campbelli, and Rattus tanezumi were new reported hosts of Cryptosporidium. The genotypes and subtypes of Cryptosporidium strains in microscopypositive specimens were further identified by PCR and sequence analysis of the small subunit rRNA and the 60-kDa glycoprotein (gp60) genes. In addition to Cryptosporidium parvum, C. muris, C. andersoni, C. wrairi, ferret genotype, and mouse genotype I, four new Cryptosporidium genotypes were identified, including the hamster genotype, chipmunk genotype III, and rat genotypes II and III. Mixed Cryptosporidium species/ genotypes were found in 10.8% of Cryptosporidium-positive specimens. Sequence analysis of the gp60 gene showed that C. parvum strains in pet Siberian chipmunks and hamsters were all of the subtype IIdA15G1, which was found previously in a human isolate in The Netherlands and lambs in Spain. The gp60 sequences of C. wrairi and the Cryptosporidium ferret genotype and mouse genotype I were also obtained. These findings suggest that pet rodents may be potential reservoirs of zoonotic Cryptosporidium species and subtypes.

The HDF can be considered an effective and safe alternative procedure compared with ACDF in the treatment of the multilevel CSM, and ACCF should be the last option.

Most of the complications of the three reconstructive techniques subsided gradually after conservative treatment; none of them needed revision surgery. The multilevel ACDF approach has the lowest rate of non-union, but a slightly higher morbidity of the laryngeal nerve-related complication if proximal segments were involved. The long corpectomy approach should be selected prudently because of the high rate of complication.

Study design A retrospective review of prospectively collected data in an academic institution. Objective To evaluate the safety and efficacy of a new type of titanium mesh cage (TMC) in single-level, anterior cervical corpectomy and fusion (ACCF). Methods Fifty-eight patients consecutive with cervical spondylotic myelopathy (CSM) from cervical degenerative spondylosis and isolated ossification of the posterior longitudinal ligament were treated with a single-level ACCF using either a new type of TMC (28 patients, group A) or the traditional TMC (30 patients, group B). We evaluated the patients for TMC subsidence, cervical lordosis (C2-C7 Cobb and Cobb of fused segments) and fusion status for a minimum of 30 months postoperatively based on spine radiographs. In addition, neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) scores. Neck pain was evaluated using a 10-point visual analog scale (VAS). Results The loss of height of the fused segments was less for group A than for group B (0.8 ± 0.3 vs. 2.8 ± 0.4 mm) (p \ 0.01); also, there was a lower rate of severe subsidence (C3 mm) in group A (4 %, 1/28) than in group B (17 %, 5/30) (p \ 0.01). There were no differences in the C2-C7 Cobb and Cobb of fused segments between the groups preoperatively or at final follow-up (p [ 0.05), but the Cobb of fused segments immediately postoperative were significantly less for group B than for group A (p \ 0.01). All patients, however, had successful fusion (100 %, each). Both groups had marked improvement in the JOA score after operation (p \ 0.01), with no significant differences in the JOA recovery ratio (p [ 0.05). The postoperative VAS neck pain scores for group A were significantly less than that for group B (p \ 0.05); severe subsidence was correlated with neck pain. Conclusions The new type of TMC provides comparable clinical results and fusion rates with the traditional TMC for patients undergoing single-level corpectomy. The new design TMC decreases postoperative subsidence (compared to the traditional TMC); the unique design of the new type of TMC matches the vertebral endplate morphology which appears to decrease the severity of subsidencerelated neck pain in follow-up.

Prognostic level III.

Between May 2002 and October 2006, 19 patients (17 men and 2 women; average age 57.2; range 47-71 years) received anterior corpectomy and fusion for severe ossification of the posterior longitudinal ligament (OPLL) in our department. Preoperative radiological evaluation showed the narrowing by the OPLL exceeded 50% in all cases, and OPLL extended from one to three vertebrae. We followed-up all patients for 12-36 months (mean 18 months). The Japanese Orthopaedic Association (JOA) score before surgery was 9.3±1.8 (range 5-12) which significantly increased to 14.2±1.3 (range 11-16) points at the last follow-up (P<0.01). The improvement rate (IR) of neurological function ranged from 22.2-87.5%, with a mean of 63.2%±15.2%. The operation also provided a significant increase in the cervical lordosis and the cord flatting rate (P< 0.01). No severe neurological complication developed. We therefore concluded that anterior decompression and fusion was effective and safe in the treatment of the selected patients, although OPLL exceeded 50% diameter of the spinal canal.

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