Volunteer orthopedic surgical trips in Nicaragua: a cost-effectiveness evaluation.

BACKGROUND: Injuries account for a substantial portion of the world's burden of disease and require effective surgical care. Volunteer surgical teams that form partnerships with hospitals help build local surgical capacity while providing immediate care. The purpose of the present study was to evaluate the cost-effectiveness of short orthopedic surgical volunteer trips as a method of reducing the global burden of surgical disease through both surgical and educational interventions. METHODS: Data were collected from a scheduled volunteer trip to Leon, Nicaragua, in January 2011 as part of the Cooperación Ortopédica Americano Nicaraguense (COAN), a 501c3 nonprofit organization established in 2002. Costs are from the COAN provider prospective with an additional analysis to include the Nicaraguan provider variable costs. The total burden of musculoskeletal disease averted from the patients receiving surgical intervention was derived using the disability-adjusted-life-years (DALYs) framework and disability weights from the disease control priority project. The cost-effectiveness ratio was calculated by dividing the total costs by the total DALYs averted. RESULTS: A total of 44.78 DALYs were averted in this study, amounting to an average of 1.49 DALYs averted per patient. The average cost per patient from the COAN provider perspective was $525.64, and from both the COAN and Nicaraguan provider perspective it was $710.97. In the base case, cost-effectiveness was $352.15 per DALY averted, which is below twice the Nicaraguan per capita gross national income ($652.40). CONCLUSIONS: Volunteer orthopedic surgical trips are cost-effective in Nicaragua. Further research should be conducted with multiple trips and with different patient populations to test the generalizability of the results.

Aseptic failure: how does the Compress(®) implant compare to cemented stems?

BACKGROUND: Failure of endoprosthetic reconstruction with conventional stems due to aseptic loosening remains a challenge for maintenance of limb integrity and function. The Compress(®) implant (Biomet Inc, Warsaw, IN, USA) attempts to avoid aseptic failure by means of a unique technologic innovation. Though the existing literature suggests survivorship of Compress(®) and stemmed implants is similar in the short term, studies are limited by population size and followup duration. QUESTIONS/PURPOSES: We therefore compared (1) the rate of aseptic failure between Compress(®) and cemented intramedullary stems and (2) evaluated the overall intermediate-term implant survivorship. METHODS: We reviewed 26 patients with Compress(®) implants and 26 matched patients with cemented intramedullary stems. The patients were operated on over a 3-year period. Analysis focused on factors related to implant survival, including age, sex, diagnosis, infection, aseptic loosening, local recurrence, and fracture. Minimum followup was 0.32 years (average, 6.2 years; range, 0.32-9.2 years). RESULTS: Aseptic failure occurred in one (3.8%) patient with a Compress(®) implant and three (11.5%) patients with cemented intramedullary stems. The 5-year implant survival rate was 83.5% in the Compress(®) group and 66.6% in the cemented intramedullary stem group. CONCLUSIONS: The Compress(®) implant continues to be a reliable option for distal femoral limb salvage surgery. Data regarding aseptic failure is encouraging, with equivalent survivorship against cemented endoprosthetic replacement at intermediate-term followup. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Sensing and actuation technologies for smart socket prostheses.

The socket is the most critical part of every lower-limb prosthetic system, since it serves as the interfacial component that connects the residual limb with the artificial system. However, many amputees abandon their socket prostheses due to the high-level of discomfort caused by the poor interaction between the socket and residual limb. In general, socket prosthesis performance is determined by three main factors, namely, residual limb-socket interfacial stress, volume fluctuation of the residual limb, and temperature. This review paper summarizes the various sensing and actuation solutions that have been proposed for improving socket performance and for realizing next-generation socket prostheses. The working principles of different sensors and how they have been tested or used for monitoring the socket interface are discussed. Furthermore, various actuation methods that have been proposed for actively modifying and improving the socket interface are also reviewed. Through the continued development and integration of these sensing and actuation technologies, the long-term vision is to realize smart socket prostheses. Such smart socket systems will not only function as a socket prosthesis but will also be able to sense parameters that cause amputee discomfort and self-adjust to optimize its fit, function, and performance.

Obliterative airway disease progresses in heterotopic airway allografts without persistent alloimmune stimulus.

BACKGROUND: Up to 50% of human lung allografts develop chronic rejection manifested as obliterative bronchiolitis (OB). This complication frequently progresses despite maximal immunosuppression, suggesting that, once initiated, factors other than alloimmunity play a role in its progression. In animals, heterotopically transplanted allograft airways develop obliterative airway disease (OAD), an immunologically mediated lesion that is used as a preclinical model of OB. We sought to determine whether OAD would progress even after removal from the alloimmune environment. METHODS: Tracheas from Lewis rats were transplanted subcutaneously into Brown Norway recipients to create allografts. After 7 or 14 days of alloimmune stimulus, these allografts were removed and retransplanted into an isogeneic environment for an additional 21 days. Histology was assessed at each time point, with quantitation of the airway epithelium and intraluminal fibroproliferation. RESULTS: Allografts exposed to 14 days of alloimmune stimulus had a significant loss of airway epithelium compared with grafts exposed to only 7 days ( <0.001). There was little fibroproliferation seen in either of these groups. After retransplantation, the grafts initially exposed to 7 days of alloimmune stimulus had few abnormalities. In contrast, the group exposed initially to 14 days of alloimmunity and retransplanted had near complete obliteration of the lumen with fibroproliferation (96.9% occlusion, =0.001) and absent airway epithelium. CONCLUSIONS: OAD progresses despite removal of alloimmunity if the initial period of alloimmune injury is sufficient. Airway epithelial loss correlated with progression to fibroproliferation, suggesting that the epithelium plays a significant role in the pathogenesis of OB.

Venous Thromboembolism After Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To measure the rate of postoperative venous thromboembolic events (VTE) after spine decompression and fusion procedures. SUMMARY OF BACKGROUND DATA: VTE after spine surgery is a serious complication, but chemoprophylaxis is not without significant risk due to the concern of epidural hematoma. Current literature report widely variable rates of VTE, and have weaknesses in sample size, specificity of diagnosis, and methodological problems with adequate patient follow-up. METHODS: State-level inpatient, ambulatory surgery, and emergency department administrative databases were used to track patients for clinically significant VTE within 90 days of discharge after a spine procedure. RESULTS: Of 357,926 patients enrolled, one-third underwent spine decompression alone, whereas two-thirds received a spine fusion. The overall rate of VTE was 1.37% (95% CI: 1.33-1.41), but varied widely depending on diagnosis, 1.03% for structural degenerative diagnoses to 10.7% for spine infection. Posterior cervical fusion had a higher rate of VTE than anterior cervical fusion, whereas anterior thoracolumbar and lumbosacral fusions had higher rates than the respective posterior approaches. Additional risk factors included patients receiving long spine fusions and having multiple procedures during the hospitalization. Forty percent of VTEs discovered after discharge were diagnosed at a different hospital. CONCLUSION: The rate of spine VTE varies widely depending on diagnosis and procedure. It is important to risk-stratify patients who present for spine surgery to identify patients at increased risk who should be monitored for the development of VTE. It is important to know that nearly half of VTEs that occur after discharge are diagnosed at different hospitals, and thus the primary surgeon may be initially unaware of the complication. These results from a large selection of historical patients may provide a tool for estimating patient risk depending on diagnosis and type of procedure. LEVEL OF EVIDENCE: 2.

Arthroscopic posteromedial capsular release for knee flexion contractures.

Extension deficits of the knee can cause functional limitations in patients after knee surgery or injury. Most frequently, they are treated with manipulations, arthroscopic anterior compartment debridements, or open posterior capsular releases once nonoperative treatment fails. However, an arthroscopic posteromedial capsular release to manage flexion deficits has yet to be studied comprehensively. Arthroscopic posteromedial capsular releases of the knee can result in improved knee motion postoperatively. An arthroscopic posteromedial capsular release involves sectioning the posteromedial capsule at its meniscofemoral portion, midway between its femoral attachment and its posterior horn medial meniscus junction. A review of 15 patients who underwent this operation was performed. Passive knee extension and flexion was measured in patients in the supine position using a goniometer at preoperative evaluations, under anesthesia prior to and immediately after the posteromedial capsular release, and at postoperative follow-up evaluations. The average time from the arthroscopic posteromedial capsular release to the final postoperative follow-up was 24.1 months. Preoperative knee extension averaged 14.7 degrees in 15 patients. The average immediate postoperative knee extension averaged -0.9 degrees. At the final postoperative follow-up, knee extension averaged 0.7 degrees. Overall knee motion improved from an average are of motion of 101.6 degrees-129.4 degrees. Arthroscopic posteromedial capsular releases and the concurrent postoperative rehabilitation program were effective in the treatment of knee extension deficits. The encouraging results of this study compare well to data presented in open posterior capsular release studies. We believe that arthroscopic posteromedial capsular releases are an effective means to address symptomatic knee extension deficits.