Anchoring of a mental nerve stimulator for treatment of facial neuropathic pain: a case illustration.

INTRODUCTION: Mental nerve stimulation is recognised as a treatment option for neuropathic facial pain. Historically however, lead migration across the mobile temporomandibular joint has prevented this procedures utility. METHODS: We describe a new method of insertion and anchoring of a mental nerve stimulator for the management of refractory neuropathic pain in the distribution of the mental nerve. We anchored the stimulator lead to the mandibular body. RESULTS: Significant analgesic effect was achieved and no lead migration had occurred at 1 year post-operatively. CONCLUSIONS: This report describes in detail the procedure of mental nerve stimulator insertion, with a novel technique of mandibular anchoring of the lead.

Development of a Multivariate Prediction Model for Successful Oswestry Disability Index Changes in L5/S1 Anterior Lumbar Interbody Fusion for Degenerative Disc Disease.

OBJECTIVE: Lower back pain associated with degenerative disc disease (DDD) is a leading cause of disability worldwide. Anterior lumbar interbody fusion (ALIF) has been shown to be effective for treating refractory DDD, but it remains unclear which patients may benefit most from the procedure. This study aims to develop a predictive model for clinical success in L5/S1 ALIF for DDD. METHODS: A retrospective cohort study of 68 patients with refractory DDD who underwent L5/S1 ALIF was performed. Clinical success was defined as an improvement in Oswestry Disability Index (ODI) of 20 points postoperatively. Exploratory analyses were performed on 16 preoperative clinical and radiographic parameters, followed by a multivariate logistic regression. Evaluation of the predictive model was performed. RESULTS: After exploratory analyses, 4 parameters were suitable for inclusion in the multivariate model. Workers' compensation status (odds ratio [OR], 0.02; 95% confidence interval [CI], 0.001-0.262; P = 0.004) and preoperative ODI (OR, 1.13; 95% CI, 1.05-1.23; P = 0.002) were statistically significant parameters. Furthermore, posterior disc height and disc depth contributed significantly to the model variance (OR, 0.69, 95% CI, 0.44-1.09 and OR, 0.97, 95% CI, 0.81-1.15, respectively). The model had a sensitivity of 81.5%, specificity of 83.3%, C-statistic of 0.921, and a calibration plot similar to the 45° reference line. CONCLUSIONS: This analysis confirms workers' compensation and low preoperative ODI as risk factors for successful L5/S1 ALIF performed for DDD. It also identifies novel prognostic factors, namely posterior disc height and disc depth. This model can aid in patient counseling and selection in the management of L5/S1 DDD.

Load Sharing and Endplate Pressure Distribution in Anterior Interbody Fusion Influenced by Graft Choice.

BACKGROUND: Cage subsidence is a known complication of spinal fusion. Various aspects of cage design have been investigated for their influence on cage subsidence, whereas the potential contribution of graft material to load sharing is often overlooked. We aimed to determine whether graft in the aperture affects endplate pressure distribution. METHODS: The pressure distributions of a polyetheretherketone interbody cage with 3 different aperture graft conditions were evaluated: empty, demineralized bone matrix, and supercritical CO2-treated allograft bone crunch (SCCO2). RESULTS: Graft materials contributed as much as half the load transmission for SCCO2, whereas demineralized bone matrix contributed one third. Endplate areas in contact with the cage demonstrated decreased areas within the highest-pressure spectrum with SCCO2 graft materials compared with empty cages. CONCLUSIONS: Graft choice plays a role in reducing peak endplate pressures. This finding is relevant to implant subsidence, as well as graft loading and remodeling.