Pettersson, Samuel D.

OBJECTIVE Laminoplasty is a common treatment for cervical spondylotic myelopathy (CSM) and for ossification of the posterior longitudinal ligament (OPLL). However, approximately 21% of patients undergoing laminoplasty develop cervical kyphotic deformity (KD). Because of the high prevalence rate of KD, several studies have sought to identify predictors for this complication, but the findings remain highly inconsistent. Therefore, the authors performed a systematic review and meta-analysis to establish reliable preoperative predictors of KD. METHODS PubMed, Scopus, and Web of Science databases were used to systematically extract potential references. The first phase of screening required the studies to be written in the English language, involve patients treated for CSM and/or OPLL via laminoplasty, and report postoperative cervical KD. The second phase required the studies to provide more than 10 patients and include a control group. The mean difference (MD) and odds ratio (OR) were calculated for continuous and dichotomous parameters. Study quality was evaluated using the Newcastle-Ottawa Scale. CSM and OPLL patients were further assessed by performing subgroup analyses. RESULTS Thirteen studies comprising patients who developed cervical KD (n = 296) and no KD (n = 1254) after receiving cervical laminoplasty for CSM or OPLL were included in the meta-analysis. All studies were retrospective cohorts and were rated as high quality. In the combined univariate analysis of CSM and OPLL patients undergoing laminoplasty, statistically significant predictors for postoperative KD included age (MD 2.22, 95% CI 0.16–4.27, p = 0.03), preoperative BMI (MD 0.85, 95% CI 0.06–1.63, p = 0.04), preoperative C2–7 range of flexion (MD 10.42, 95% Cl 4.24–16.59, p = 0.0009), preoperative C2–7 range of extension (MD −4.59, 95% CI −6.34 to −2.83, p < 0.00001), and preoperative center of gravity of the head to the C7 sagittal vertical axis (MD 26.83, 95% CI 9.13–44.52, p = 0.003). Additionally, among CSM patients, males were identified as having a greater risk for postoperative KD (OR 1.73, 95% CI 1.02–2.93, p = 0.04). CONCLUSIONS The findings from this study currently provide the largest and most reliable review on preoperative predictors for cervical KD after laminoplasty. Given that several of the included studies identified optimal cutoff points for the variables that are significantly associated with KD, further investigation into the development of a preoperative risk scoring system that can accurately predict KD in the clinical setting is encouraged. PROSPERO registration no.: CRD42022299795 ( https://www.crd.york.ac.uk/PROSPERO/ ).

OBJECTIVE A review article assessing all the risk factors reported in the literature for postoperative cerebellar mutism syndrome (pCMS) among children remains absent. The authors sought to perform a systematic review and meta-analysis to evaluate this issue. METHODS PubMed, Embase, and Web of Science were queried to systematically extract potential references. The articles relating to pCMS were required to be written in the English language, involve pediatric patients (≤ 18 years of age), and provide extractable data, which included a comparison group of patients who did not develop pCMS. The quality of the included studies was evaluated using the Newcastle-Ottawa Scale. Data were pooled using RevMan 5.4, and publication bias was assessed by visual inspection for funnel plot asymmetry. The study protocol was registered through PROSPERO (ID: CRD42021256177). RESULTS Overall, 28 studies involving 2276 patients were included. Statistically significant risk factors identified from univariate analysis were brainstem invasion (OR 4.28, 95% CI 2.23–8.23; p < 0.0001), fourth ventricle invasion (OR 12.84, 95% CI 4.29–38.44; p < 0.00001), superior cerebellar peduncle invasion (OR 6.77, 95% CI 2.35–19.48; p = 0.0004), diagnosis of medulloblastoma (OR 3.26, 95% CI 1.93–5.52; p < 0.0001), medulloblastoma > 50 mm (OR 8.85, 95% CI 1.30–60.16; p = 0.03), left-handedness (OR 6.57, 95% CI 1.25–34.44; p = 0.03), and a vermis incision (OR 5.44, 95% CI 2.09–14.16; p = 0.0005). On the other hand, a tumor located in the cerebellar hemisphere (OR 0.23, 95% CI 0.06–0.92; p = 0.04), cerebellar hemisphere compression (OR 0.23, 95% CI 0.11–0.45; p < 0.0001), and intraoperative imaging (OR 0.36, 95% CI 0.18–0.72; p = 0.004) reduced the risk of pCMS. CONCLUSIONS This study provides the largest and most reliable review of risk factors associated with pCMS. Although some risk factors may be dependent on one another, the data may be used by surgeons to better identify patients at risk for pCMS and for intervention planning.