Citations

AbstractCryopreserved bone allografts(CBA) are susceptible to infection, nonunion, and late stress fracture. Although surgical revascularization by intramedullary implantation of an arteriovenous bundle (AV bundle) generates a neoangiogenic blood supply, there is potential for vascular ingrowth‐mediated bone resorption to weaken the graft. For this reason, we have evaluated changes in CBA mechanical properties of structural tibial allografts with and without surgically induced angiogenesis. Cryopreserved tibia bone allografts were transplanted to reconstruct a 3.5 cm segmental tibial defect in 16 Yucatan mini pigs. Surgical revascularization was performed in half by implantation of a cranial tibial AV bundle, (revascularization group). A control group of identical size had a ligated AV bundle implanted, (ligated group). At 20 weeks micro‐computed tomography (CT) measured bone mineral density (BMD) as well as bone union. Reference point indentation (RPI) compared cortex material properties, and axial compression determined the allotransplant compressive modulus. Seven of eight tibiae in the angiogenesis group were healed at both junction points at 20 weeks. Only four of eight tibiae healed in the ligated control group. There was no significant difference between the revascularization and ligated control groups in BMD and axial compression test. Similarly, RPI parameters were statistically equal. In paired comparisons with contralateral tibias, however, some RPI values were significantly worse in the ligated control group tibiae. This study demonstrates no adverse effect of surgical angiogenesis on cryopreserved structural bone allograft biomechanical properties in a large animal orthotopic segmental tibial defect model. These data suggest the potential value of surgical angiogenesis in clinical limb‐sparing reconstructive surgery.

A multidisciplinary brachial plexus clinic has been a relatively new concept, offering different surgical speciality perspectives on the treatment of brachial plexus injuries. The resulting collaborative effort has proven to be greater than the sum of its parts. In this review, the history, philosophy of care, development/implementation and impact of a creation of a multidisciplinary brachial plexus team at the Mayo Clinic are detailed.

Background: A cohort of patients with traumatic brachial plexus injuries (BPIs) underwent elective amputation following unsuccessful surgical reconstruction or delayed presentation. The results of amputation with and without a myoelectric prosthesis (MEP) using nonintuitive controls were compared. We sought to determine the benefits of amputation, and whether fitting with an MEP was feasible and functional. Methods: We conducted a retrospective review of patients with BPI who underwent elective upper-extremity amputation at a single institution. Medical records were reviewed for demographics, injury and reconstruction details, amputation characteristics, outcomes, and complications. Prosthesis use and MEP function were assessed. The minimum follow-up for clinical outcomes was 12 months. Results: Thirty-two patients with BPI and an average follow-up of 53 months underwent elective amputation between June 2000 and June 2020. Among the cases were 18 transhumeral amputations, 12 transradial amputations, and 2 wrist disarticulations. There were 29 pan-plexus injuries, 1 partial C5-sparing pan-plexus injury, 1 lower-trunk with lateral cord injury, and 1 lower-trunk injury. Amputation occurred, on average, at 48.9 months following BPI and 36.5 months following final reconstruction. Ten patients were fitted for an MEP with electromyographic signal control from muscles not normally associated with the intended function (nonintuitive control). Average visual analog scale pain scores decreased post-amputation: from 4.8 pre-amputation to 3.3 for the MEP group and from 5.4 to 4.4 for the non-MEP group. Average scores on the Disabilities of the Arm, Shoulder and Hand questionnaire decreased post-amputation, but not significantly: from 35 to 30 for the MEP group and from 43 to 40 for the non-MEP group. Patients were more likely to be employed following amputation than they were before amputation. No patient expressed regret about undergoing amputation. All patients in the MEP group reported regular use of their prosthesis compared with 29% of patients with a traditional prosthesis. All patients in the MEP group demonstrated functional terminal grasp/release that they considered useful. Conclusions: Amputation is an effective treatment for select patients with BPI for whom surgical reconstruction is unsuccessful. Patients who underwent amputation reported decreased mechanical pain, increased employment rates, and a high rate of satisfaction following surgery. In amputees with sufficient nonintuitive electromyographic signals, MEPs allow for terminal grasp/release and are associated with high rates of prosthesis use. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The application of autologous fat grafting in reconstructive surgery is commonly used to improve functional form. This review aims to provide an overview of the scientific evidence on the biology of adipose tissue, the role of adipose-derived stem cells, and the indications of adipose tissue grafting in peripheral nerve surgery. Adipose tissue is easily accessible through the lower abdomen and inner thighs. Non-vascularized adipose tissue grafting does not support oxidative and ischemic stress, resulting in variable survival of adipocytes within the first 24 hours. Enrichment of adipose tissue with a stromal vascular fraction is purported to increase the number of adipose-derived stem cells and is postulated to augment the long-term stability of adipose tissue grafts. Basic science nerve research suggests an increase in nerve regeneration and nerve revascularization, and a decrease in nerve fibrosis after the addition of adipose-derived stem cells or adipose tissue. In clinical studies, the use of autologous lipofilling is mostly applied to secondary carpal tunnel release revisions with promising results. Since the use of adipose-derived stem cells in peripheral nerve reconstruction is relatively new, more studies are needed to explore safety and long-term effects on peripheral nerve regeneration. The Food and Drug Administration stipulates that adipose-derived stem cell transplantation should be minimally manipulated, enzyme-free, and used in the same surgical procedure, e.g. adipose tissue grafts that contain native adipose-derived stem cells or stromal vascular fraction. Future research may be shifted towards the use of tissue-engineered adipose tissue to create a supportive microenvironment for autologous graft survival. Shelf-ready alternatives could be enhanced with adipose-derived stem cells or growth factors and eliminate the need for adipose tissue harvest.

Background: Free functioning muscle transfer is a reconstructive option to restore elbow flexion in brachial plexus injuries. The authors determined the impact of body mass index, age, and location of distal tendon attachment on elbow flexion strength after free functioning muscle transfer in traumatic brachial plexus injury patients. Methods: A retrospective review of patients who underwent free functioning muscle transfer for elbow flexion as part of their brachial plexus injury reconstruction with a minimum 2-year follow-up were evaluated. Outcomes assessed included elbow flexion strength (British Medical Research Council grade) and change in Disabilities of the Arm, Shoulder and Hand questionnaire and visual analogue scale pain scores. Results: One hundred six patients met inclusion criteria. The average age was 32 years, and the average body mass index was 27.1 kg/m2; 56.5 percent of patients achieved M3 or greater muscle grade using the authors’ strict modification of the British Medical Research Council scale. Disabilities of the Arm, Shoulder and Hand questionnaire scores improved from 45.7 to 38.8 (p < 0.05). Visual analogue scale pain scores decreased, but this trend did not obtain significance. Age and body mass index both had a significant negative impact on final free functioning muscle transfer grade (p < 0.05). Use of a distal tendon insertion led to improved muscle grade outcomes, with targeting of wrist extension being superior to finger flexion (p < 0.05). Simultaneous musculocutaneous nerve grafting did not significantly alter final elbow flexion strength. Conclusions: Increasing age and body mass index both imparted a deleterious effect on free functioning muscle transfer muscle grade. Distal muscle targets had better strength outcomes than when the biceps tendon was used. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Abstract Background Some surgeons advocate for concomitant proximal row carpectomy (PRC) with total wrist arthrodesis (TWA), though there are limited data to support or oppose this view. Questions/Purposes Does concomitant PRC improve rates of union, revision, hardware loosening, hardware failure, and hardware removal in TWA? Patients and Methods A retrospective cohort study of patients who underwent TWA with and without concomitant PRC between January 2008 and December 2018 was undertaken. Patients were included if they underwent TWA using a dorsal spanning plate. Patients were excluded if they underwent partial wrist arthrodesis, revision TWA, or TWA with nondorsal spanning plate fixation. Results A total of 183 wrists in 180 patients were included in the study, 96 (52.5%) in the TWA only and 87 (47.5%) in the TWA + PRC groups. Median clinical and radiographic follow-up was 18.0 months (3.0–133.0 months) in the TWA + PRC group and 18.5 months (2.0–126.0 months) in the TWA only group (p = 0.907). No difference in nonunion (TWA + PRC: 13/87 [14.9%], TWA only: 18/96 [18.8%], odds ratio: 0.76, p = 0.494), revision (TWA + PRC: 5/87 [5.75%], TWA only: 8/96 [8.33%], hazard ratio [HR]: 0.73, p = 0.586), loosening (TWA + PRC: 4/87 [4.60%], TWA only: 6/96 [6.25%], HR: 0.74, p = 0.646), failure (TWA + PRC: 5/87 [5.75%], TWA only: 4/96 [4.17%], HR: 1.55, p = 0.530), and removal (TWA + PRC: 12/87 [13.8%], TWA only: 16/96 [16.7%], HR: 0.84, p = 0.634) were identified. Conclusion Concomitant PRC might not improve rates of union or diminish complications in patient undergoing TWA. The role of PRC and the rationale for its use in TWA need to be individualized and discussed with patients prior to surgery. Level of Evidence This is a Level IV, therapeutic study.