Objectives Circulating mesenchymal stem cells (MSCs) participate in fracture healing and can be used to enhance fracture healing. This study investigated how CD271-selected MSCs travel in circulation and when it is the optimal time to apply MSCs intravenously during fracture healing. Methods Based on the expression of CD271, MSCs were isolated from human bone marrow and labeled with cypate, a near infrared fluorochrome. A unilateral closed fracture was created at the femur in immunodeficient mice. The cypate-labeled MSCs were injected into the tail vein of the mice at days 1 and 3 after fracture, and were tracked by near infrared imaging. The mice were euthanized at 3 weeks after fracture. Immunohistochemistry was performed to detect human MSCs at the fracture sites. Migration of CD271-selected MSCs, under the influence of stem cell derived factor-1 (SDF-1), was assessed in vitro. Results Intravenously injected at day1, but not day 3, after fracture, CD271-selected MSCs accumulated at the fracture sites significantly and that lasted for at least 7 days. All fractures, with or without MSC injections, healed in 3 weeks. Human cells were localized at the fracture sites in mice by immunohistochemistry. CD271-selected MSCs migrated toward the medium contained SDF-1 in vitro. Conclusions After intravenous injection, CD271-selected MSCs were recruited to fracture sites. The stages of fracture healing influenced the homing of culture-expanded MSCs. In mice, an optimal window of intravenous injection of MSCs was around 24 hours after fracture. Clinical Relevance Intravenous application of MSCs may serve as a practical route to deliver stem cells for the treatment of fracture non-union and delayed union. Levels of evidence Level I
Orthopaedic surgeons commonly have the misconception that patients with tibial plateau fractures will likely go on to posttraumatic knee arthritis requiring total knee arthroplasty (TKA). In younger patients, osteochondral allograft (OCA) transplantation is an alternative method to address posttraumatic knee arthritis. The purpose of this study was (1) to identify our institutional failure rate following tibial plateau open reduction and internal fixation (ORIF) (failure was defined as conversion to TKA or OCA); (2) to determine if there are patient- or injury-related risk factors predictive of failure; and (3) to characterize differences between patients treated with TKA versus those treated with OCA transplantation. A 10-year retrospective review was conducted to identify patients treated at our institution with a tibial plateau fracture. Patients included in the final analysis were at least 18 years of age with an articular fracture (AO/OTA 41 B/C). The primary outcome was subsequent ipsilateral OCA or TKA. There were 350 patients (359 tibial plateau fractures) with a mean follow-up of 22.3 months (range, 6-133 months) who met inclusion criteria. Twenty-seven fractures (7.5%) were subsequently converted to a TKA or OCA at an average of 3.75 ± 3.1 years following their initial surgery. Patients who consumed tobacco were 2.3 times more likely to require a joint replacement (confidence interval [CI], 1.0-5.2; = 0.04). Those patients who received an OCAs were significantly younger as compared with their TKA peers, both at time of initial injury (37 vs. 51 years, = 0.02) and at time of surgery (41 vs. 55 years, = 0.009). The joint replacement rate in this study is similar to those studies in the published literature that focused solely on the prevalence of conventional TKA. Tobacco is a risk factor for failure following tibial plateau ORIF. Patients who were treated with an OCA were younger at time of injury and failure.
Patella fractures present some of the more complicated fracture patterns in orthopaedic trauma care. This is partially due to the small size of the fragments but also the articular nature of each fragment. Fixation methods such as cerclage wiring, excision of smaller fragments, and screw fixation of larger fragments all have their own challenges. Our study examined our Level I trauma center's experience with variable angle locked 2.7 mm titanium plates for treatment of comminuted patella fractures or treatment of patellar nonunion. After Institutional Review Board approval, we used billing records to identify 105 patients who had undergone operative management of a displaced patella fracture between January 2011 and December 2015. We reviewed the radiographs of these patients to identify which patients underwent treatment with a mesh plate. We found 16 patients (6 males and 10 females) who had undergone fixation with a mesh plate; mean age was 47 years. Nine patients underwent primary open reduction internal fixation (ORIF) and seven underwent mesh plate fixation for failed ORIF of a patella fracture. The mean visual analog pain score was 2.75 (range, 0-9). The mean range of motion was 1 degree of extension (range, 0-10 degrees) to 110 degrees of flexion (range, 45-135 degrees). All fractures healed. Five patients required hardware removal for pain. This review illustrates the effectiveness of the locking mesh plate in two challenging clinical scenarios: that of patellar nonunion and comminuted fractures that preclude standard fixation methods. Although multiple options exist for patellar fracture fixation, the titanium mesh locking plate can be an effective option for retaining the patella in the setting of comminution. Further comparative studies should be undertaken to determine which method of treatment may be superior in the treatment of these fractures.
Although neurological sequelae after VAI can be devastating, routine screening after cervical spine fracture may not be warranted. Beside cost, our study suggests it is rarely associated with symptoms, and the asymptomatic patient rarely receives treatment due to concomitant injuries. Our study reinforces the need for further research to establish protocols so that patient-appropriate, cost-effective evaluation and treatment can be provided.
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