Pain and functional outcomes of the sacroiliac joint after platelet-rich plasma injection: a descriptive review.

The purpose of this manuscript is to highlight and review the status of literature regarding efficacy of platelet-rich plasma (PRP) in the treatment of sacroiliac joint (SIJ) dysfunction. A review of the literature on PRP interventions on the SIJ or ligaments was performed. Seven studies had improvements in their respective primary end point and demonstrated a strong safety profile without any serious adverse events. Only five articles demonstrated clinical efficacy of >50% in their primary outcome measures. There appears to be inconsistent and insufficient evidence for a conclusive recommendation for or against SIJ PRP. There is a need for adequately powered well-designed, standardized, double-blinded randomized clinical trials to determine the effectiveness of PRP in SIJ-mediated pain.

Spinal Accessory and Suprascapular Nerve Injury After Human Bite.

ABSTRACT: This is a unique clinical case of spinal accessory and suprascapular nerve injury related to a human bite not yet described elsewhere. The case emphasizes the importance of considering local trauma of the posterior triangle of the neck in case of shoulder weakness with electrophysiologic evidence of combined spinal accessory and suprascapular nerve injury.

First human experience with autologous Schwann cells to supplement sciatic nerve repair: report of 2 cases with long-term follow-up.

OBJECTIVE Long-segment injuries to large peripheral nerves present a challenge to surgeons because insufficient donor tissue limits repair. Multiple supplemental approaches have been investigated, including the use of Schwann cells (SCs). The authors present the first 2 cases using autologous SCs to supplement a peripheral nerve graft repair in humans with long-term follow-up data. METHODS Two patients were enrolled in an FDA-approved trial to assess the safety of using expanded populations of autologous SCs to supplement the repair of long-segment injuries to the sciatic nerve. The mechanism of injury included a boat propeller and a gunshot wound. The SCs were obtained from both the sural nerve and damaged sciatic nerve stump. The SCs were expanded and purified in culture by using heregulin ß1 and forskolin. Repair was performed with sural nerve grafts, SCs in suspension, and a Duragen graft to house the construct. Follow-up was 36 and 12 months for the patients in Cases 1 and 2, respectively. RESULTS The patient in Case 1 had a boat propeller injury with complete transection of both sciatic divisions at midthigh. The graft length was approximately 7.5 cm. In the postoperative period the patient regained motor function (Medical Research Council [MRC] Grade 5/5) in the tibial distribution, with partial function in peroneal distribution (MRC Grade 2/5 on dorsiflexion). Partial return of sensory function was also achieved, and neuropathic pain was completely resolved. The patient in Case 2 sustained a gunshot wound to the leg, with partial disruption of the tibial division of the sciatic nerve at the midthigh. The graft length was 5 cm. Postoperatively the patient regained complete motor function of the tibial nerve, with partial return of sensation. Long-term follow-up with both MRI and ultrasound demonstrated nerve graft continuity and the absence of tumor formation at the repair site. CONCLUSIONS Presented here are the first 2 cases in which autologous SCs were used to supplement human peripheral nerve repair in long-segment injury. Both patients had significant improvement in both motor and sensory function with correlative imaging. This study demonstrates preliminary safety and efficacy of SC transplantation for peripheral nerve repair.

Safety of Autologous Human Schwann Cell Transplantation in Subacute Thoracic Spinal Cord Injury.

The rationale for implantation of autologous human Schwann cells (SCs) in persons with subacute spinal cord injury (SCI) is based on evidence that transplanted SCs are neuroprotective, support local axonal plasticity, and are capable of myelinating axons. A Phase I clinical trial was conducted to evaluate the safety of autologous human SC transplantation into the injury epicenter of six subjects with subacute SCI. The trial was an open-label, unblinded, non-randomized, non-placebo controlled study with a dose escalation design and standard medical rehabilitation. Participants were paraplegics with neurologically complete, trauma-induced spinal lesions. Autologous SCs were cultured in vitro from a sural nerve harvested from each participant and injected into the epicenter of the spinal lesion. Outcome measures for safety were protocol compliance, feasibility, adverse events, stability of neurological level, absence of detectable mass lesion, and the emergence of clinically significant neuropathic pain or muscle spasticity no greater than expected for a natural course cohort. One year post-transplantation, there were no surgical, medical, or neurological complications to indicate that the timing or procedure for the cell transplantation was unsafe. There were no adverse events or serious adverse events related to the cell therapy. There was no evidence of additional spinal cord damage, mass lesion, or syrinx formation. We conclude that it is feasible to identify eligible candidates, appropriately obtain informed consent, perform a peripheral nerve harvest to obtain SCs within 5-30 days of injury, and perform an intra-spinal transplantation of highly purified autologous SCs within 4-7 weeks of injury.

The Use of Autologous Schwann Cells to Supplement Sciatic Nerve Repair With a Large Gap: First in Human Experience.

Insufficient donor nerve graft material in peripheral nerve surgery remains an obstacle for successful long-distance regeneration. Schwann cells (SCs) can be isolated from adult mammalian peripheral nerve biopsies and can be grown in culture and retain their capacity to enhance peripheral nerve regeneration within tubular repair strategies in multiple animal models. Human Schwann cells (hSCs) can be isolated, expanded in number, and retain their ability to promote regeneration and myelinate axons, but have never been tested in a clinical case of peripheral nerve injury. A sural nerve biopsy and peripheral nerve tissue from the traumatized sciatic nerve stumps was obtained after Food and Drug Administration (FDA) and Institutional Review Board (IRB) approval as well as patient consent. The SCs were isolated after enzymatic digestion of the nerve and expanded with the use of heregulin ß1 (0.1 µg/ml) and forskolin (15 mM). After two passages the Schwann cell isolates were combined with sural nerve grafts to repair a large sciatic nerve defect (7.5 cm) after a traumatic nerve injury. The sural nerve and the traumatized sciatic nerve ends both served as an excellent source of purified (90% and 97%, respectively) hSCs. Using ultrasound and magnetic resonance imaging (MRI) we were able to determine continuity of the nerve graft repair and the absence of tumor formation. The patient had evidence of proximal sensory recovery and definitive motor recovery distal to the repair in the distribution of the tibial and common peroneal nerve. The patient did experience an improvement in her pain scores over time. The goals of this approach were to determine the safety and clinical feasibility of implementing a new cellular repair strategy. In summary, this approach represents a novel strategy in the treatment of peripheral nerve injury and represents the first reported use of autologous cultured SCs after human peripheral nerve injury.

The use of allograft and recombinant human bone morphogenetic protein for instrumented atlantoaxial fusions.

BACKGROUND: Iliac crest autograft is the historic gold standard for bone grafting, but is associated with a significant patient morbidity. Fusion rates of C1-C2 up to 88.9% using allograft and 96.7% using autologous iliac crest bone graft can be achieved when combined with rigid screw fixation. We sought to determine our fusion rate when combining allograft with recombinant human bone morphogenetic protein-2 (rh-BMP2) and rigid screw fixation. METHODS: We reviewed our experience using allograft, bone morphogenetic protein (rh-BMP2) and screw fixation of C1-C2 in 52 patients and examined indications, surgical technique, fusion rates, and complications. In 28 patients, corticocancellous allograft pieces were laid along decorticated bone after a C2 neurectomy was performed. In 24 patients, unicortical iliac crest allograft was precision-cut to fit between the C1 lamina and C2 spinous processes. RESULTS: Fifty-two C1-C2 fusions were performed with allograft, rh-BMP2, and rigid screw fixation. There were 25 female and 27 male patients ranging in age from 6 to 92 years (mean, 65.8 years). Operative indications included trauma (56%), degenerative disease (21%), rheumatoid arthritis (15%), congenital anomalies (6%), and synovial cyst (2%). The mean follow-up was 23.9 ± 2.1 months (range, 2-55 months). The mean dose of rh-BMP2 used for all patients was 4.5 mg (range, 2.2-12 mg). In patients who achieved sufficient follow-up, 100% achieved solid fusion: 45/50 Lenke A, 5/50 Lenke B. There were no known complications attributable to the use of rh-BMP2. CONCLUSIONS: The use of small doses of rh-BMP2 added to allograft in addition to rigid screw fixation is a safe and highly effective means of promoting a solid fusion of the atlantoaxial complex and spares the patient the morbidity of iliac crest harvest.

Automatic classification of motor unit potentials in surface EMG recorded from thenar muscles paralyzed by spinal cord injury.

Involuntary electromyographic (EMG) activity has only been analyzed in the paralyzed thenar muscles of spinal cord injured (SCI) subjects for several minutes. It is unknown if this motor unit activity is ongoing. Longer duration EMG recordings can investigate the biological significance of this activity. Since no software is currently capable of classifying 24h of EMG data at a single motor unit level, the goal of this research was to devise an algorithm that would automatically classify motor unit potentials by tracking the firing behavior of motor units over 24h. Two channels of thenar muscle surface EMG were recorded over 24h from seven SCI subjects with a chronic cervical level injury using a custom data logging device with custom software. The automatic motor unit classification algorithm developed here employed multiple passes through these 24-h EMG recordings to segment, cluster, form global templates and classify motor unit potentials, including superimposed potentials. The classification algorithm was able to track an average of 19 global classes in seven 24-h recordings with a mean (+/-SE) accuracy of 89.9% (+/-0.98%) and classify potentials from these individual motor units with a mean accuracy of 90.3% (+/-0.97%). The algorithm could analyze 24h of data in 2-3 weeks with minimal input from a person, while a human operator was estimated to take more than 2 years. This automatic method could be applied clinically to investigate the fasciculation potentials often found in motoneuron disorders such as amyotrophic lateral sclerosis.