Genetic and cellular evidence of decreased inflammation associated with reduced incidence of posttraumatic arthritis in MRL/MpJ mice.

OBJECTIVE: To examine the relationship between inflammation and posttraumatic arthritis (PTA) in a murine intraarticular fracture model. METHODS: Male C57BL/6 and MRL/MpJ "superhealer" mice received tibial plateau fractures using a previously established method. Mice were killed on day 0 (within 4 hours of fracture) and days 1, 3, 5, 7, 28, and 56 after fracture. Synovial tissue samples, obtained prior to fracture and on days 0, 1, 3, 5, and 7 after fracture, were examined by reverse transcription-polymerase chain reaction for gene expression of proinflammatory cytokines and chemokines. Synovial fluid and serum samples were collected to measure cytokine concentrations, using enzyme-linked immunosorbent assay. Whole joints were examined histologically for the extent of synovitis and cartilage degradation, and joint tissue samples from all time points were analyzed immunohistochemically to evaluate the distribution of interleukin-1 (IL-1). RESULTS: Compared to C57BL/6 mice, MRL/MpJ mice had less severe intraarticular and systemic inflammation following joint injury, as evidenced by lower gene expression of tumor necrosis factor α and IL-1ß in the synovial tissue and lower protein levels of IL-1α and IL-1ß in the synovial fluid, serum, and joint tissues. Furthermore, after joint injury, MRL/MpJ mice had lower gene expression of macrophage inflammatory proteins and macrophage-derived chemokine (CCL22) in the synovial tissue, and also had reduced acute and late-stage infiltration of synovial macrophages. CONCLUSION: C57BL/6 mice exhibited higher levels of inflammation than MRL/MpJ mice, indicating that MRL/MpJ mice are protected from PTA in this model. These data thus suggest an association between joint tissue inflammation and the development and progression of PTA in mice.

Radiographic outcomes of ring external fixation for malunion and nonunion.

Ring external fixators such as the Ilizarov external fixator (IEF) and Taylor Spatial Frame (TSF) have revolutionized management of limb deformity. This study examines radiographic outcomes for treatment of malunions and nonunions with secondary emphasis on comparing radiographic union rates of TSF and IEF. A retrospective chart and radiograph review was performed. Fifty-four patients were included. Most injuries were in the tibia (96%). Fifty patients (93%) achieved radiographic union, two patients required further fixation, and two patients elected to undergo amputation. The preoperative coronal deformity improved from a mean of 12° (range, 0°-41°) to within 3° anatomic. Sagittal deformity improved from a mean of 11° (range, 0°-49°) to within 5° anatomic with some patients intentionally left in recurvatum to accommodate plantarflexion contractures. Limb length discrepancies were corrected to within 1 cm. Twenty-five patients experienced complications (mostly superficial pin tract infections). No statistically significant differences in the radiographic outcomes of TSF compared to IEF were identified.

Surgical Repair of Posttraumatic Hallux Valgus Deformity in a Collegiate Football Player: A Case Report.

CASE: We report a rare case of posttraumatic hallux valgus in a collegiate football player after an acute medial collateral ligament tear of the first metatarsophalangeal joint. The patient was treated with a modification of the modified McBride technique, using an all-suture anchor for the medial ligamentous complex repair. There was return to sport at 5 months and a Foot and Ankle Outcome Score of 95% at 10 months. CONCLUSION: A modified McBride procedure further modified with the utilization of an all-suture anchor for the medial ligamentous complex repair can result in correction of deformity, pain-free movement and return to sport.

Post-Traumatic Hallux Valgus: A Modified Surgical Technique.

Post-traumatic hallux valgus, a turf toe variant, is a rare, yet limiting injury. According to the literature, the deformity has been associated with acute medial collateral ligament tears, turf toe variant injuries, Lisfranc injury patterns, and first metatarsal fractures. There have been few documented cases of post-traumatic hallux valgus secondary to medial collateral ligament tears, and the treatment has been variable. Some authors have described direct end-to-end repair of the ligament to address the deformity, while others have described a modified McBride bunionectomy involving a Silver bunionectomy, lateral soft tissue release, and medial capsular and ligamentous repair. We propose a modified technique similar to the modified McBride bunionectomy, however, with the use of an all-suture anchor in the medial capsular and ligamentous repair. Our belief is that the all-suture anchor will allow for a stronger repair that will meet the physical demands of everyday ambulation and athletic participation. We used this technique in an individual who had evidence of a medial ligamentous complex injury of the hallux on MRI and failed conservative management. Postoperatively, the patient is immobilized until they can begin working on range of motion, strengthening, and finally to achieve return to full activity and sports.

Relative Age Effect: Beyond the Youth Phenomenon.

Introduction. The relative age effect (RAE) refers to performance advantage of youth born in the first quarter of the birth year when auditioning for select, age-restricted sports. This advantage conferred to the older athlete is a result of being more physically and emotionally mature, therefore, assumed to be a more advanced player. We hypothesize an RAE exists in Olympic athletes, and this extends across selected categories of athletes (by gender), such as team versus individual sports, winter versus summer athletes, and sports using a ball versus those not using a ball. Methods. We extended the exploration of an RAE beyond specific sports by examining the birth quarter of more than 44 000 Olympic athlete's birthdates, born between 1964-1996. The data were summarized by birth quarter (January 1 to March 31, etc) and presented as percentages and 95% confidence intervals. Results. The fractions of births in the first versus the fourth quarter were significantly different ( P < .001) from each other for the summer and winter Olympians, ball and nonball sports, and team as well as individual sports. Conclusions. The general presence of an RAE in Olympic athletes exists regardless of global classification.

Lisfranc Injuries in the Athlete.

Lisfranc injuries to the tarsometatarsal complex of the midfoot have become increasingly recognized in the athletic population. Regardless of mechanism, any injury that results in instability in the midfoot requires operative stabilization to preserve function and enable return to sport. In this manuscript, the anatomy, etiology, prevalence, current treatment modalities, and clinical outcomes of patients who suffer Lisfranc injuries are reviewed, with a special focus on the unique characteristics surrounding such an injury in an athlete. LEVEL OF EVIDENCE: Level V, expert opinion.

Secondary Arthrodesis After Total Ankle Arthroplasty.

BACKGROUND: While it is thought that stresses through the subtalar and talonavicular joints will be decreased after total ankle replacement (TAR) relative to ankle fusion, progressive arthritis or deformity of these joints may require a fusion after a successful TAR. However, after ankle replacement, it is unknown how hindfoot biomechanics and blood supply may be affected. Consequently, subsequent hindfoot joint fusion may be adversely affected. METHODS: We retrospectively identified a consecutive series of 1001 primary TARs performed between January 1998 and December 2014. We identified patients who underwent a secondary triple, subtalar or talonavicular arthrodesis to treat progressive arthritis or pes planus deformity. Clinical outcomes including pain and functional outcome scores, revision procedures, delayed union, nonunion, complications, and failure rates were recorded. Twenty-six patients (2.6%) required a subtalar (18), talonavicular (3), talonavicular and subtalar (3), or triple arthrodesis (2). Of these patients, 14 (54%) were males with an average age of 63.2 years and a mean 70.9 months follow-up. We then compared these patients to 13 patients who had a subtalar fusion after an ankle arthrodesis. RESULTS: The most common type of fixation used was 2 variable-pitch screws across each joint. Fresh-frozen allograft cancellous chips were the most common supplement to the fusion construct (80.8%). The mean time between TAR and secondary fusion procedure was 37.5 months. Overall, 92.3% of the patients went on to fusion. Two patients (7.7%) had a delayed union and 2 patients had a nonunion (7.7%) and were considered operative failures. There were 3 repeat procedures related to the arthrodesis procedure: 1 conversion of a subtalar to a triple arthrodesis, 1 revision talonavicular fusion, and 1 revision subtalar fusion. The average time to weight bearing after arthrodesis was 8.7 weeks; the mean time to radiographic and clinical fusion was 26.5 weeks. There were no secondary complications associated with the arthrodesis. Pain and functional outcome scores improved significantly. There were no differences in the rates of subsequent fusions among implant choices, though the time to fusion in the mobile-bearing prosthesis was significantly longer than the 2 fixed-bearing prostheses. Compared with the data of 13 patients with prior ipsilateral ankle arthrodeses and subtalar fusions, patients who had an ankle replacement had a higher fusion rate (P = .03) and had a similar time to fusion. CONCLUSION: Hindfoot arthrodesis following a TAR was safe and effective in improving function and pain. Additionally, a hindfoot arthrodesis following a TAR had a higher fusion rate than a subtalar fusion following an ankle arthrodesis. Although the time to healing was relatively long, various hindfoot fusions were used to treat progressive arthritis and deformity with high fusion rates. LEVEL OF EVIDENCE: Level III, comparative case series.

The adult ball-and-socket ankle joint: surgical management of late ankle and subtalar arthritis.

BACKGROUND: We review the surgical management of 4 adult patients with ball-and-socket ankle deformity who developed end-stage subtalar and/or ankle joint arthritis. METHODS: We retrospectively reviewed a series of 4 adult patients with ball-and-socket ankle configurations who underwent surgical treatment for either end-stage tibiotalar or subtalar arthritis, with either subtalar arthrodesis or total ankle replacement (TAR). Clinical outcome, including subjective pain assessment, limitation of activities, and difficulty with shoe wear, were assessed at follow-up. RESULTS: A total of 5 ankles in 4 patients were identified that met the inclusion criteria. There were 3 subtalar arthrodeses in 2 patients and 2 primary TARs in 2 patients. At an average follow-up of 30.5 (range = 17 to 59) months, there were no failures, although 1 patient who underwent TAR was considered an impending failure with aseptic component loosening. Of the 4 patients, 3 resumed normal activity with minimal pain and were very pleased with their overall outcome. CONCLUSION: Standard surgical interventions for ankle and subtalar arthritis, such as total ankle arthroplasty and subtalar arthrodesis, can be successfully performed in patients with ball-and-socket ankles; clinical outcome and survivorship, however, may be inferior to that in patients with normal ankle configurations. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case Series.

Comparison of First- and Second-Generation Fixed-Bearing Total Ankle Arthroplasty Using a Modular Intramedullary Tibial Component.

BACKGROUND: This series reviews the clinical and radiographic outcomes of patients who underwent total ankle replacement (TAR) using first- and second-generations of a modern fixed-bearing prosthesis utilizing a modular intramedullary stem. METHODS: A consecutive series of first- and second-generation primary TARs with modular intramedullary stems were identified. Clinical outcome data were collected prospectively--including visual analog scale for pain, American Orthopaedic Foot & Ankle Society hindfoot-ankle, Short Musculoskeletal Function Assessment, and Short Form-36 scores. Preoperative coronal plane deformity and correction of deformity after TAR were assessed. Complications, subsequent procedures, and failure rates were compared. A total of 193 first- and 56 second-generation patients were identified with a mean follow-up of 3.7 and 2.1 years, respectively. RESULTS: Clinical outcome data reflected significant improvements at 1 year postoperatively, and improvements were maintained at 2-year follow-up for each group. Improvement in visual analog scale scores were significantly better in the second-generation group at 1 year postoperatively, but this was not maintained at 2 years. Mean coronal tibiotalar angles for ankles with preoperative varus or valgus deformities were significantly improved. Correction was maintained until final follow-up, with no significant differences in deformity improvement between groups. The rate of reoperation at 2 years postoperatively on the affected foot or ankle subsequent to the index ankle replacement for patients in the first-generation group (18.5%) was higher compared to the second-generation group (15.9%), but the time until reoperation was not statistically significant (P = .376). The implant failure rate was higher in the first-generation group (6.0%) compared to the second-generation group (2.6%) at 2 years postoperatively, but the time until failure was not significantly different (P = .295). CONCLUSION: Patients who underwent TAR with a first- or second-generation fixed-bearing prosthesis with an intramedullary tibial component demonstrated significant improvements in all measures of pain and function with sustained improvements in coronal plane alignment. The second-generation prosthesis demonstrated slightly better improvements at 1 year and was associated with lower reoperation and implant failure rates. LEVEL OF EVIDENCE: Level II, comparative series.

Silfverskiold's test in total ankle replacement with gastrocnemius recession.

BACKGROUND: For patients undergoing primary total ankle replacement (TAR) with an equinus contracture, gastrocnemius recession may be performed to increase dorsiflexion. We examined whether gastrocnemius recession would significantly increase dorsiflexion even with a negative Silfverskiöld test. METHODS: Data were prospectively collected on a consecutive series of 29 patients who underwent TAR. All were deemed to require lengthening of the posterior soft tissue structures for unacceptable equinus contracture. Once each patient was under anesthesia, Silfverskiöld's test was performed. A digital photograph was taken with the ankle at maximum passive dorsiflexion with the knee at 0 degrees of flexion and again with the knee at 30 degrees of flexion. Strayer gastrocnemius recession was then performed in standard fashion in every patient. After recession, Silfverskiöld's test was again performed with photographs obtained in the same manner. The digital photographs demonstrating the results of the preoperative and postoperative Silfverskiöld's tests in both knee positions were analyzed and the degree of ankle dorsiflexion measured. RESULTS: Regardless of the results of Silfverskiöld's test, after gastrocnemius recession, patients had an average increase of 12.6 ± 1.6 degrees of dorsiflexion with the knee extended compared to the same position preoperatively (P < .0001) and an increase of 10.1 ± 2.0 degrees with the knee flexed (P < .001). In 6 patients Silfverskiöld's test was markedly positive preoperatively; in this group, recession resulted in an average increase of dorsiflexion of 17.8 ± 3.6 degrees with the knee extended (P = .004) and 13.4 ± 5.4 degrees with the knee flexed (P = .055). For the remaining 23 patients with a negative preoperative Silfverskiöld's test, dorsiflexion increased by 11.3 ± 1.6 (P < .0001) and 9.3 ± 2.2 degrees (P = .0003) with the knee extended and flexed, respectively. CONCLUSION: Our data show that a gastrocnemius recession resulted in a significant, reproducible increase in dorsiflexion regardless of the results of the Silfverskiöld test while avoiding potential push-off and plantarflexion weakness associated with an Achilles lengthening. LEVEL OF EVIDENCE: Level IV, case series.

Outcomes After Total Ankle Replacement in Association With Ipsilateral Hindfoot Arthrodesis.

BACKGROUND: Ipsilateral hindfoot arthrodesis in combination with total ankle replacement (TAR) may diminish functional outcome and prosthesis survivorship compared to isolated TAR. We compared the outcome of isolated TAR to outcomes of TAR with ipsilateral hindfoot arthrodesis. METHODS: In a consecutive series of 404 primary TARs in 396 patients, 70 patients (17.3%) had a hindfoot fusion before, after, or at the time of TAR; the majority had either an isolated subtalar arthrodesis (n = 43, 62%) or triple arthrodesis (n = 15, 21%). The remaining 334 isolated TARs served as the control group. Mean patient follow-up was 3.2 years (range, 24-72 months). RESULTS: The SF-36 total, AOFAS Hindfoot-Ankle pain subscale, Foot and Ankle Disability Index, and Short Musculoskeletal Function Assessment scores were significantly improved from preoperative measures, with no significant differences between the hindfoot arthrodesis and control groups. The AOFAS Hindfoot-Ankle total, function, and alignment scores were significantly improved for both groups, albeit the control group demonstrated significantly higher scores in all 3 scales. Furthermore, the control group demonstrated a significantly greater improvement in VAS pain score compared to the hindfoot arthrodesis group. Walking speed, sit-to-stand time, and 4-square step test time were significantly improved for both groups at each postoperative time point; however, the hindfoot arthrodesis group completed these tests significantly slower than the control group. There was no significant difference in terms of talar component subsidence between the fusion (2.6 mm) and control groups (2.0 mm). The failure rate in the hindfoot fusion group (10.0%) was significantly higher than that in the control group (2.4%; p < 0.05). CONCLUSION: To our knowledge, this study represents the first series evaluating the clinical outcome of TARs performed with and without hindfoot fusion using implants available in the United States. At follow-up of 3.2 years, TAR performed with ipsilateral hindfoot arthrodesis resulted in significant improvements in pain and functional outcome; in contrast to prior studies, however, overall outcome was inferior to that of isolated TAR. LEVEL OF EVIDENCE: Level II, prospective comparative series.

Impact of perioperative allogeneic and autologous blood transfusion on acute wound infection following total knee and total hip arthroplasty.

BACKGROUND: Patients undergoing total hip or knee arthroplasty frequently receive blood transfusions. The relationship between transfusion and the risk of infection following total joint arthroplasty is unclear. In this study, we sought to examine the impact of allogeneic and autologous transfusion on the risk of acute infection following total hip and total knee arthroplasty. METHODS: We performed a retrospective study of consecutive primary total knee arthroplasties and total hip arthroplasties. Patients who had a reoperation for suspected infection within three months after the arthroplasty were identified. Differences in risk factors were assessed across transfusion groups: no transfusion, autologous only, and allogeneic exposure (allogeneic with or without additional autologous transfusion). Backward-stepwise logistic regression analysis was used to compare reoperations (as outcomes) between cases with and those without allogeneic exposure. Prespecified covariates were body mass index, diabetes, an American Society of Anesthesiologists (ASA) score of >2, preoperative hematocrit, and total number of units transfused perioperatively. RESULTS: We identified 3352 patients treated with a total hip or knee arthroplasty (1730 total knee arthroplasties and 1622 total hip arthroplasties) for inclusion in the study. Transfusion was given in 1746 cases: 836 of them had allogeneic exposure, and 910 had autologous-only transfusion. There were thirty-two reoperations (0.95%) for suspected infection. Between-group risk-factor differences were observed. The mean age and the rates of diabetes, immunosuppression, ASA scores of >2, and bilateral surgery were highest in the allogeneic group, as were estimated blood loss, surgery duration, and total number of units transfused (p < 0.001). In the unadjusted analyses, the rate of reoperations for suspected infection was higher in the cases with allogeneic exposure (1.67%) than in those without allogeneic exposure (0.72%) (p = 0.013). Autologous-only transfusion was not associated with a higher reoperation rate. However, multivariable logistic regression demonstrated that the total number of units transfused (p = 0.011) and an ASA score of >2 (p = 0.008)-but not allogeneic exposure-were significantly predictive of a reoperation. CONCLUSIONS: Perioperative allogeneic transfusion was associated with a higher rate of reoperations for suspected acute infection. However, patients with allogeneic exposure had increased infection risk factors. After adjustment for the total number of units transfused and an ASA score of >2, allogeneic exposure was not significantly predictive of a reoperation for infection.

Advanced technology paths to global climate stability: energy for a greenhouse planet.

Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.