Are we putting ourselves in danger? Occupational hazards and job safety for orthopaedic surgeons.

As physicians, we strive to meet the needs of our patients. In doing so, we are often exposed to hazards that have the potential to not only compromise our health, but also our ability to deliver the best possible healthcare. Occupational hazards specific to the field of orthopaedics include infectious organisms, radiation, surgical smoke, chemicals, hazardous noise, musculoskeletal injury, and psychosocial stressors. Even though orthopaedic surgeons acknowledge the risk, most lack in-depth knowledge of the associated long-term harm associated with these hazards and ways of reducing risk of exposure. Orthopaedic surgeons should increase awareness, follow established guidelines, and integrate preventative measures to create the safest possible work environment. It is our hope that by improving our own health, we will be better equipped to address the health concerns of those we serve-our patients.

Two-level cervical disc arthroplasty in patients with Klippel-Feil syndrome: A case report and review of the literature.

BACKGROUND: Klippel-Feil syndrome (KFS) is defined by multiple abnormal segments of the cervical spine with congenital synostosis of two or more cervical vertebrae. KFS patients who demonstrate progressive symptomatic instability and/or neurologic sequelae are traditionally managed with operative decompression and arthrodesis. CASE DESCRIPTION: A 44-year-old female with chronic neck pain and radiculopathy and a C7-T1 KFS presented with adjacent segment degenerative disc disease at the C5-6 and C6-7 levels. She was successfully managed with a two-level cervical disc arthroplasty (CDA). CONCLUSION: Patients with KFS and disease at two contiguous, adjacent levels (e.g., cervical disc disease) may be safely and effectively managed with two-level CDA.

Metabolic factors and post-traumatic arthritis may influence the increased rate of surgical site infection in patients with human immunodeficiency virus following total hip arthroplasty.

BACKGROUND: The impact of CD4+ T-cell count and highly active antiretroviral therapy (HAART) on the rate of surgical site infection (SSI) in patients with human immunodeficiency virus (HIV) undergoing total hip arthroplasty is still unclear. The goals of this study were to assess the rate of perioperative infection at a large tertiary care referral center and to identify risk factors in HIV+ patients undergoing total hip arthroplasty (THA). METHODS: This study was a prospective, observational study at a single medical center from 2000-2017. Patients who were HIV+ and underwent THA were followed from the preoperative assessment period, through surgery and for a 2-year follow-up period. RESULTS: Sixteen of 144 HIV+ patients (11%) undergoing THA developed perioperative surgical site infections. Fourteen patients (10%) required revision THA within a range of 12 to 97 days after the initial surgery. The patients' mean age was 49.6 ± 4.5 years, and the most common diagnosis prompting THA was osteonecrosis (96%). Patients who developed SSI had a lower waist-hip ratio (0.86 vs. 0.93, p = 0.047), lower high density lipoprotein cholesterol (45.8 vs. 52.5, p = 0.015) and were more likely to have post-traumatic arthritis (12.5% vs. 0%, p = 0.008). Logistic regression analysis demonstrated that current alcohol use and higher waist-hip ratio were significant protectors against infection (p < 0.05). No other demographic, medical, immunologic parameters, or specific HAART regimens were associated with perioperative infection. CONCLUSIONS: Immunologic status as measured by CD4+ cell count, HIV viral load, and medical therapy do not appear to influence the development of SSI in HIV+ patients undergoing THA. Metabolic factors and post-traumatic arthritis may influence the increased rate of infection in HIV+ patients following THA.

Electrospun, synthetic bone void filler promotes human MSC function and BMP-2 mediated spinal fusion.

INTRODUCTION: Synthetic bone grafts are often used to achieve a well-consolidated fusion mass in spinal fusion procedures. These bone grafts function as scaffolds, and ideally support cell function and facilitate protein binding. OBJECTIVE: The aim was to characterize an electrospun, synthetic bone void filler (Reb) for its bone morphogenetic protein (BMP)-2 release properties and support of human mesenchymal stem cell (hMSC) function in vitro, and its efficacy in promoting BMP-2-/bone marrow aspirate-(BMA)-mediated posterolateral spinal fusion (PLF) in vivo. METHODS: BMP-2 release kinetics from Reb versus standard absorbable collagen sponge (ACS) was determined. hMSC adhesion and proliferation on Reb was tested using cell counting, fluorescence microscopy and MTS. Cell osteogenic differentiation was quantified via cellular alkaline phosphatase (ALP) activity. For in vivo analysis, 18 Lewis rats were treated during PLF surgery with the following groups: (I) Reb + BMA, (II) Reb + BMA + BMP-2 and (III) BMA. A safe, minimally effective dose of BMP-2 was used. Fusion consolidation was followed for 3 months using radiography and micro-CT. After sacrifice, fusion rate and biomechanical stiffness was determined using manual palpation, biomechanical tests and histology. RESULTS: In vitro, BMP-2 release kinetics were similar between Reb versus ACS. MSC proliferation and differentiation were increased in the presence of Reb. At 3 months post-surgery, fusion rates were 29% (group I), 100% (group II), and 0% (group III). Biomechanical stiffness was higher in group II versus I. Micro-CT showed an increased bone volume and connectivity density in group II. Trabecular thickness was increased in group I versus II. H&E staining showed newly formed bone in group II only. CONCLUSIONS: Reb possesses a high protein binding affinity and promotes hMSC function. Combination with BMA and minimal dose BMP-2 allowed for 100% bone fusion in vivo. This data suggests that a minimally effective dose of BMP-2 can be used when combined with Reb.

Anti-Inflammatory Peptide Attenuates Edema and Promotes BMP-2-Induced Bone Formation in Spine Fusion.

Recombinant human bone morphogenic protein-2 (BMP-2)-loaded absorbable collagen sponges (ACS) have been successfully used to enhance bone formation and to induce spinal fusion in humans. However, side effects, such as soft tissue edema and inflammation, have been reported. NEMO binding domain peptide (NBD) inhibits activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a central regulator of immune response. In this study, we investigated NBD's potential to reduce BMP-2-induced soft tissue inflammation without affecting BMP-2-mediated spinal fusion in rat. For evaluation of soft tissue inflammation, ACS containing BMP-2, BMP-2+NBD, NBD, or ACS only were implanted into intramuscular paraspinal sites of 32 rats. At day 2 postsurgery, edema formation at the implant sites was assessed using magnetic resonance imaging. T2-weighted relaxation time (T2-RT) values were increased in the BMP-2 group compared with BMP-2+NBD, NBD, and ACS groups. No difference in T2-RT values was detected between BMP-2+NBD versus NBD and ACS controls. Postsacrifice, histological analysis of the implant-surrounding zones showed increased mononuclear cell infiltration in the BMP-2 group compared with BMP-2+NBD and controls. The presence of BMP-2 increased relative NF-κB binding and gene expression of inflammatory markers, interleukin (IL)1ß, IL6, IL18, and chemokine ligand (CCL)2 and CCL3 compared with controls. In the BMP-2+NBD group, cytokine expression was blocked. No differences were found between BMP-2+NBD and control groups. For evaluation of spinal fusion, posterolateral intertransverse lumbar fusion procedures were performed on 16 rats. ACS were loaded with BMP-2 or BMP-2+NBD. After sacrifice at week 12, microcomputed tomographic assessment of the fusion site detected a higher bone volume and reduced trabecular spacing in the BMP-2+NBD group compared with BMP-2. Histological analysis did not show any differences in newly formed bone microarchitecture. In summary, addition of NBD to BMP-2-loaded ACS reduces BMP-2-induced soft tissue edema formation and mononuclear cell infiltration, diminishes NF-κB binding, and thus blocks transcription of NF-κB-regulated cytokines in rat. Furthermore, NBD stimulates bone formation in BMP-2-mediated spinal fusion, possibly through crosstalk of the NF-κB pathway with other pathways. The results of this study might provide the basis to develop new therapeutic bone grafting approaches with combinatory administration of BMP-2 and NBD for spinal fusion.