Matthew J. Pingree

Incidence of Clinically Significant Percutaneous Spinal Cord Stimulator Lead Migration

To examine the incidence of percutaneous spinal cord stimulator lead migration, given current hardware and surgical technique.

Ultrasound-guided transversus abdominis plane injection with computed tomography correlation: a cadaveric study

Background Ultrasound-guided transversus abdominis plane (TAP) injections are increasingly being used as an alternative to traditional perioperative analgesia in the abdominal region. With the use of a “blind” TAP block technique, these procedures have had variable success in cadaver and in vivo studies. For more accurate injection with the intended medication, ultrasound guidance allows visualization of the correct layer of the abdominal wall planes in which the thoracolumbar nerves reside. Objective To assess the spread of various volumes of contrast placed under live ultrasound guidance into the TAP using computed tomography (CT). Methods Four TAP blocks were performed on 2 fresh frozen cadaver torsos with predetermined contrast volumes of 5, 10, 15, or 20 mL. A CT scan of the cadaver was then performed and interpreted by a musculoskeletal radiologist. This cadaver study was carried out at a tertiary care academic medical center. Results Cranial–caudal spread of injected contrast correlated with increasing injectate volume and was roughly 1 vertebral level (end plate to end plate) for the 5 mL injection and 2 vertebral levels for the 10, 15, and 20 mL injections. However, the degree of injectate spread may be different for live patients than for cadavers. Conclusion This study helps further the understanding of injectate spread following ultrasound-guided TAP injections. Specifically, it suggests that 15 mL provides additional cranial–caudal spread and may be an optimal volume of anesthesia.

Occipital Neuromodulation: Ultrasound Guidance for Peripheral Nerve Stimulator Implantation

We report a case of chronic left‐sided occipital neuralgia in a 21‐year old female patient. The patient in question suffered from chronic greater occipital neuralgia for a duration of many years, which had been refractory to other conservative medical management strategies. Blockade of the greater occipital nerve with local anesthetic was consistently useful in attenuating the patients pain, though the effects were always short lived. Consequently, a successful trial of greater occipital nerve stimulation was undertaken.

Delayed ulnar neuropathy at the wrist following open carpal tunnel release.

Open carpal tunnel release is a common and successful treatment of median neuropathy at the wrist (carpal tunnel syndrome). We report a case of delayed ulnar neuropathy at the wrist with onset 2 months after open carpal tunnel release. Clinical findings, electrophysiological studies, magnetic resonance imaging, and surgical exploration demonstrated ulnar nerve compression at Guyons canal resulting from translocation of the carpal tunnel contents. To our knowledge, this is an unreported complication of open carpal tunnel release that merits wide appreciation. Muscle Nerve, 2005

Ultrasound-guided thoracic facet injections: description of a technique.

The purpose of this study was to describe a technique using ultrasound guidance to perform thoracic facet joint injections.

Incidence of neuropathic pain after radiofrequency denervation of the third occipital nerve

The purpose of this study was to identify the incidence of neuropathic pain occurring after radiofrequency neurotomy of the third occipital nerve (TON). This study was conducted at a teaching hospital from January 1, 2008, to March 31, 2010. With institutional review board approval, Current Procedural Terminology codes were used to identify patients who received radiofrequency ablation (RFA) of the nerves supplying the C2-3 facet joint and the TON. The C3 dorsal ramus provides innervation to the C2-3 facet joint and the suboccipital cutaneous region, and procedures that included ablation to this region were reviewed for complications. Postprocedural data were collected by reviewing follow-up appointment notes and telephone calls. Included were patients who had new neuropathic pain in the distribution of the TON after RFA. They described what they were feeling as burning, tingling, or numbness. All patients who presented with complaints had normal neurologic findings and no secondary cause for their symptoms. The included patient medical records were then reviewed for severity and duration of symptoms and the need for treatment with pain medication. Sixty-four patients underwent C2-3 RFA or TON RFA, and 12 patients were identified as experiencing ablation-induced third occipital neuralgia, an incidence rate of 19%. This finding suggests that patients undergoing RFA of the nerves supplying the C2-3 joint or TON are at risk for postprocedural third occipital neuralgia. This possibility may affect providing informed consent as well as anticipating and managing postprocedural pain.

Ultrasound-guided intra-articular knee injection in an obese patient.

ABSTRACT A 35-yr-old woman was referred to our outpatient clinic for a right intra-articular knee aspiration and injection. She had a medical history notable for lymphedema and morbid obesity (Fig. 1). Her body mass index was recently calculated at greater than 60 kg/m2. She had a history of four previous nonguided knee joint injections performed elsewhere that provided no significant improvement in pain. On physical examination, it was difficult to localize common knee joint bony landmarks, including the medial and lateral borders of the patella (Fig. 2). Consequently we opted to utilize ultrasound guidance for the knee joint injection via the technique described herein. FIGURE 1. Photo of patient’s right knee. FIGURE 2. Patient’s knee x-ray revealing medial compartment narrowing. The skin was palpated to localize the anterior patellar region with the knee flexed to 30 degrees. Using a Philips CX50 ultrasound machine (Philips Electronics, Andover, MA) and standard ultrasound gel, the patella was visualized using a 5-1 MHz curvilinear probe in an anatomic transverse plane. The transducer was then moved proximally until the patella was no longer visualized. As is often visualized in the knee joint of patients with osteoarthritis, a small effusion was seen in the prepatellar pouch between the femur and the quadriceps tendon (Fig. 3). Once an optimal ultrasound image was obtained in this location, the transducer position was marked on the skin. Using strict sterile technique (sterile skin prep, ultrasound probe cover, sterile ultrasound gel, etc.), the knee joint effusion in the suprapatellar pouch was revisualized in an anatomic transverse plane. Local anesthesia was obtained with lidocaine using a 25-gauge 2-in needle under live ultrasound guidance from a lateral to medial transverse approach. Afterward, following the same needle trajectory, a 22-gauge 3.5-in spinal needle was advanced into the knee joint under direct ultrasound visualization (Fig. 4). A total of 8 ml of serosanguineous fluid was aspirated from the knee joint. Afterward, a mixture of corticosteroid and local anesthetic was injected into the knee joint while observing the suprapatellar pouch filling in real time. The patient reported minimal pain during the procedure and complete pain relief immediately after the injection. FIGURE 3. Preinjection labeled ultrasound image. FIGURE 4. Postinjection ultrasound image.

Clinical Efficacy of an Ultrasound-Guided Greater Occipital Nerve Block at the Level of C2

Background and Objectives The purpose of this prospective open-label study was to investigate the analgesic effects of an ultrasound-guided greater occipital nerve (GON) block at the level of C2, as the nerve courses superficially to the obliquus capitis inferior muscle. Methods Patients with a diagnosis of occipital neuralgia or cervicogenic headache were recruited for the study. Ultrasound-guided GON blocks at the level of C2 were performed by experienced clinicians according to a standardized protocol. Numeric rating scale pain scores were recorded preinjection and at 30 minutes, 2 weeks, and 4 weeks after injection. Results A total of 14 injections were performed with a mean procedure time of 3.75 minutes. Anesthesia in the GON distribution was achieved for 86% of patients at 30 minutes postinjection. Compared with baseline, numeric rating scale scores decreased by a mean of 3.78 at 30 minutes (P < 0.001), 2.64 at 2 weeks (P = 0.006), and 2.21 at 4 weeks (P = 0.01). There were no significant adverse events reported during the study period. Conclusions This prospective open-label study demonstrated successful blockade of the GON at the level of C2 using a novel ultrasound-guided technique. Significant reductions in pain scores were observed over the 4-week study period, and no adverse events were reported. The observations from this study provide important preliminary data for future randomized trials involving patients with occipital neuralgia and cervicogenic headache.

Immediate Adverse Events in Interventional Pain Procedures: A Multi-Institutional Study

SETTING Interventional procedures directed toward sources of pain in the axial and appendicular musculoskeletal system are performed with increasing frequency. Despite the presence of evidence-based guidelines for such procedures, there are wide variations in practice. Case reports of serious complications such as spinal cord infarction or infection from spine injections lack appropriate context and create a misleading view of the risks of appropriately performed interventional pain procedures. OBJECTIVE To evaluate adverse event rate for interventional spine procedures performed at three academic interventional spine practices. METHODS Quality assurance databases at three academic interventional pain management practices that utilize evidence-based guidelines [1] were interrogated for immediate complications from interventional pain procedures. Review of the electronic medical record verified or refuted the occurrence of a complication. Same-day emergency department transfers or visits were also identified by a records search. RESULTS Immediate complication data were available for 26,061 consecutive procedures. A radiology practice performed 19,170 epidural steroid (primarily transforaminal), facet, sacroiliac, and trigger point injections (2006-2013). A physiatry practice performed 6,190 spine interventions (2004-2009). A second physiatry practice performed 701 spine procedures (2009-2010). There were no major complications (permanent neurologic deficit or clinically significant bleeding [e.g., epidural hematoma]) with any procedure. Overall complication rate was 1.9% (493/26,061). Vasovagal reactions were the most frequent event (1.1%). Nineteen patients (<0.1%) were transferred to emergency departments for: allergic reactions, chest pain, symptomatic hypertension, and a vasovagal reaction. CONCLUSION This study demonstrates that interventional pain procedures are safely performed with extremely low immediate adverse event rates when evidence-based guidelines are observed.

Sonographically Guided Costotransverse Joint Injections A Computed Tomographically Controlled Cadaveric Feasibility Study

The primary purpose of this study was to describe and validate a novel sonographically guided costotransverse (CTRV) joint injection technique.