OBJECTIVE Kyphotic deformity resulting from the loss of cervical lordosis (CL) is a rare but serious complication after cervical laminoplasty (CLP), and it is essential to recognize the risk factors. Previous studies have demonstrated that a greater flexion range of motion (fROM) and smaller extension ROM (eROM) in the cervical spine are associated with the loss of CL after CLP. Considering these facts together, one can hypothesize that an indicator representing the gap between fROM and eROM (gROM) is highly useful in predicting postoperative CL loss. In the present study, the authors aimed to investigate the risk factors of marked CL loss after CLP for cervical spondylotic myelopathy (CSM), including the gROM as a potential predictor. METHODS Patients who had undergone CLP for CSM were divided into those with and those without a loss of more than 10° in the sagittal Cobb angle between C2 and C7 at the final follow-up period compared to preoperative measurements (CL loss [CLL] group and no CLL [NCLL] group, respectively). Demographic characteristics, surgical information, preoperative radiographic measurements, and posterior paraspinal muscle morphology evaluated with MRI were compared between the two groups. fROM and eROM were examined on neutral and flexion-extension views of lateral radiography, and gROM was calculated using the following formula: gROM (°) = fROM − eROM. The performance of variables in discriminating between the CLL and NCLL groups was assessed using the receiver operating characteristic (ROC) curve. RESULTS This study included 111 patients (mean age at surgery 68.3 years, 61.3% male), with 10 and 101 patients in the CLL and NCLL groups, respectively. Univariate analyses showed that fROM and gROM were significantly greater in the CLL group than in the NCLL group (40.2° vs 26.6°, p < 0.001; 31.6° vs 14.3°, p < 0.001, respectively). ROC curve analyses revealed that both fROM and gROM had excellent discriminating capacities; gROM was likely to have a higher area under the ROC curve than fROM (0.906 vs 0.860, p = 0.094), with an optimal cutoff value of 27°. CONCLUSIONS The gROM is a highly useful indicator for predicting a marked loss of CL after CLP. For CSM patients with a preoperative gROM exceeding 30°, CLP should be carefully considered, since kyphotic changes can develop postoperatively.

No abstract

No abstract

No abstract

Study Design: This is a retrospective study. Objective: The objective of this study was to investigate the surgical outcomes of postural instability and its predictors in patients with cervical myelopathy (CM). Summary of Background Data: Although several studies have shown impaired postural stability in CM patients, there remains a paucity of literature examining its surgical outcome. Materials and Methods: Postural stability was assessed using a stabilometer preoperatively, at the early phase (3–6 months postoperatively), and 1-year postoperatively, employing 2 stabilometric parameters: sway area [SwA (cm2): the amount of sway of gravity center assessed by the outer peripheral area of the stabilogram] and sway density [SwD (/cm): the indicator of proprioceptive reflexes calculated by the locus length of the stabilogram per SwA]. Twenty-seven healthy age-matched, sex-matched, and body mass index-matched subjects were recruited as controls. To investigate the predictors of postoperative postural instability, univariate, and multivariate analyses were performed, including demographic data, preoperative neurological symptom severity, radiographic findings, and preoperative stabilometric parameters as independent variables. Results: Altogether, 54 CM patients were included in the present study. SwA was 7.89±0.84, 4.78±0.68, and 4.85±0.49, and SwD was 14.63±0.85, 20.41±1.23, and 19.36±1.40 preoperatively, at the early phase, and 1-year postoperatively, respectively, and significant improvement was found in both parameters postoperatively. However, at all timepoints, these parameters were significantly worse in CM patients than in the healthy subjects (SwA: 2.68±0.24, SwD: 24.91±1.83). Multivariate analyses showed that worse preoperative stabilometric parameters were significantly related to worse postoperative stabilometric parameters. Conclusions: Surgery significantly improved postural stability in CM patients; however, it did not reach the level observed in healthy controls, even postoperatively. A predictor of greater residual postoperative postural instability was a greater level of preoperative postural instability. In CM patients, to achieve better surgical outcome of postural stability, surgical intervention is recommended before the symptoms related to bodily imbalance deteriorate. Level of Evidence: Level III.