Tobin T. Eckel

Microbiology and injury characteristics in severe open tibia fractures from combat.

BACKGROUND: Type III open tibia fractures are common combat injuries. The purpose of the study was to evaluate the effect of injury characteristics and surveillance cultures on outcomes in combat-related severe open tibia fractures. METHODS: We conducted a retrospective study of all combat-related open Gustilo and Anderson (G/A) type III diaphyseal tibia fractures treated at our centers between March 2003 and September 2007. RESULTS: One hundred ninety-two Operation Iraqi Freedom/Operation Enduring Freedom military personnel with 213 type III open tibial shaft fractures were identified. Fifty-seven extremities (27%) developed a deep infection and 47 extremities (22%) ultimately underwent amputation at an average follow-up of 24 months. Orthopedic Trauma Association type C fractures took significantly longer to achieve osseous union (p = 0.02). G/A type III B and III C fractures were more likely to undergo an amputation and took longer to achieve fracture union. Deep infection and osteomyelitis were significantly associated with amputation, revision operation, and prolonged time to union. Surveillance cultures were positive in 64% of extremities and 93% of these cultures isolated gram-negative species. In contrast, infecting organisms were predominantly gram-positive. CONCLUSIONS: Type III open tibia fractures from combat unite in 80.3% of cases at an average of 9.2 months. We recorded a 27% deep infection rate and a 22% amputation rate. The G/A type is associated with development of deep infection, need for amputation, and time to union. Positive surveillance cultures are associated with development of deep infection, osteomyelitis, and ultimate need for amputation. Surveillance cultures were not predictive of the infecting organism if a deep infection subsequently develops. LEVEL OF EVIDENCE: III.

Effect of Teriparatide [rhPTH(1,34)] and Calcitonin on Intertransverse Process Fusion in a Rabbit Model

Study Design. Randomized, double-blinded, placebo controlled animal study. Objective. To evaluate the effect of teriparatide and calcitonin after an intertransverse process spinal fusion in a rabbit model. Summary of Background Data. It is widely recognized that some osteoporosis medications, including bisphosphonates, can interfere with bone healing. Although prescribed frequently in the treatment of osteoporosis, the effect of teriparatide and calcitonin on spinal fusion has not been fully elucidated. We hypothesized that teriparatide, being the only anabolic medication for osteoporosis treatment, would have a beneficial effect on spine fusion. Methods. Fifty-one New Zealand white rabbits underwent a posterolateral L5–L6 intertransverse process arthrodesis using autogenous iliac crest bone graft. The rabbits were randomly divided into 3 groups. All animals received daily subcutaneous injections of group I (n = 17) 1 mL of saline placebo; group II (n = 17) 10 &mgr;g/kg/day of teriparatide; group III (n = 17) 14 IU/animal of calcitonin during the 8-week postoperative period. Postmortem analyses included manual palpation, radiographic, biomechanical, and histologic assessment. Three random 10× fields were examined/graded within the cephalad, middle, and caudal regions of each section (810 fields). Fusion quality was graded using the Emery histologic scale (0–7 based on fibrous/bone content of the fusion mass). Results. Histologic fusion rates for teriparatide averaged 86.7% and was significantly greater than the autograft control group (50%) (P = 0.033). Radiographically, there was a strong trend towards teriparatide being superior to the calcitonin group (85.7% vs. 56.3%, respectively; P = 0.07). The average Emery grading score was 5.99 ± 1.46 SD for the autologous group and 6.26 ± 0.93 SD for the teriparatide group (P = 0.031). Although not significant, the teriparatide group showed less motion in flexion/extension, lateral bending, and axial rotation. Conclusion. Our results suggest that teriparatide enhances spinal fusion while calcitonin has a neutral effect. The teriparatide group had the best histologic fusion rate and Emery scores, while the calcitonin group was similar to the saline controls. Although not significant, the teriparatide group had a strong trend towards superior radiographic fusion over the calcitonin group.

Low lumbar burst fractures

BACKGROUND CONTEXT The most common location for burst fractures occurs at the thoracolumbar junction, where the stiff thoracic spine meets the more flexible lumbar spine. With our current military conflicts in Iraq and Afghanistan, we have seen a disproportionate number of low lumbar burst fractures. PURPOSE To report our institutional experience in the management of low lumbar burst fractures. STUDY DESIGN Retrospective review. METHODS We performed a retrospective review of medical records and radiographs for all patients treated at our institution with combat-related injuries and thoracolumbar fractures. We included all patients who had sustained a burst fracture from T12 to L5 and had at least 1-year clinical follow-up. RESULTS Thirty-two patients sustained burst fractures. Nineteen patients (59.4%) had low lumbar (L3-L5) burst fractures, and 12 patients (37.5%) had thoracolumbar junction (T12-L2) burst fractures as their primary injury. Additionally, seven patients sustained less severe burst fractures at an additional level. One patient sustained burst fractures at both upper and lower lumbar levels. Of the low lumbar fractures, 52.6% had evidence of neurologic injury, two of which were complete. Similarly, in the upper lumbar group, 58.2% sustained a neurologic injury, two of which were complete. Twenty-two patients underwent surgical intervention, complicated by infection in 18%. At most recent follow-up, all but one patient with presenting neurologic injury had persistent deficits. CONCLUSION Low lumbar burst fractures are the predominant combat-related spine injury in our current military conflicts. The rigidity offered by current body armor may effectively lower the transition zone that normally occurs at the thoracolumbar junction, thereby, transferring forces into the lower lumbar spine. Increased awareness of this fracture pattern is warranted by all surgeons because of unique clinical challenges associated with its treatment. Although the incidence is increased in the military population, other surgeons may be involved with long-term care of these patients on completion of their military service.

Low lumbar burst fractures: a unique fracture mechanism sustained in our current overseas conflicts

BACKGROUND CONTEXT The most common location for burst fractures occurs at the thoracolumbar junction, where the stiff thoracic spine meets the more flexible lumbar spine. With our current military conflicts in Iraq and Afghanistan, we have seen a disproportionate number of low lumbar burst fractures. PURPOSE To report our institutional experience in the management of low lumbar burst fractures. STUDY DESIGN Retrospective review. METHODS We performed a retrospective review of medical records and radiographs for all patients treated at our institution with combat-related injuries and thoracolumbar fractures. We included all patients who had sustained a burst fracture from T12 to L5 and had at least 1-year clinical follow-up. RESULTS Thirty-two patients sustained burst fractures. Nineteen patients (59.4%) had low lumbar (L3-L5) burst fractures, and 12 patients (37.5%) had thoracolumbar junction (T12-L2) burst fractures as their primary injury. Additionally, seven patients sustained less severe burst fractures at an additional level. One patient sustained burst fractures at both upper and lower lumbar levels. Of the low lumbar fractures, 52.6% had evidence of neurologic injury, two of which were complete. Similarly, in the upper lumbar group, 58.2% sustained a neurologic injury, two of which were complete. Twenty-two patients underwent surgical intervention, complicated by infection in 18%. At most recent follow-up, all but one patient with presenting neurologic injury had persistent deficits. CONCLUSION Low lumbar burst fractures are the predominant combat-related spine injury in our current military conflicts. The rigidity offered by current body armor may effectively lower the transition zone that normally occurs at the thoracolumbar junction, thereby, transferring forces into the lower lumbar spine. Increased awareness of this fracture pattern is warranted by all surgeons because of unique clinical challenges associated with its treatment. Although the incidence is increased in the military population, other surgeons may be involved with long-term care of these patients on completion of their military service.

Does the Zone of Injury in Combat-Related Type III Open Tibia Fractures Preclude the Use of Local Soft Tissue Coverage?

Objectives: Does the large zone of injury in high-energy, combat-related open tibia fractures limit the effectiveness of rotational flap coverage? Design: Retrospective consecutive series. Setting: This study was conducted at Brooke Army Medical Center, Walter Reed Army Medical Center, and National Naval Medical Center between March 2003 and September 2007. Patients/Participants: We identified 67 extremities requiring a coverage procedure out of 213 consecutive combat-related Type III open diaphyseal tibia fractures. Intervention: The 67 Type III B tibia fractures were treated with rotational or free flap coverage. Main Outcome Measures: Flap failure, reoperation, infection, amputation, time to union, and visual pain scale. Results: There were no differences between the free and rotational flap cohorts with respect to demographic information, injury characteristics, or treatment before coverage. The reoperation and amputation rates were significantly lower for the rotational coverage group (30% and 9%) compared with the free flap group (64% and 36%; P = 0.05 and P = 0.03, respectively). The coverage failure rate was also lower for the rotational flap cohort (7% versus 27%, P = 0.08). The average time to fracture union for the free flap group was 9.5 months (range, 5-15.8 months) and 10.5 months (range, 3-41 months) for the rotational flap group (P = 0.99). Conclusions: There was a significantly lower amputation and reoperation rate for patients treated with rotational coverage. Contrary to our hypothesis and previous reports, the zone of injury in combat-related open tibia fractures does not preclude the use of local rotational coverage when practicable.

Biomechanical comparison of 4 different lateral plate constructs for distal fibula fractures.

Background: Displaced lateral malleolar fractures are often treated with reduction and surgical stabilization. However, there has not been a comprehensive laboratory comparison to determine the most appropriate device for treating these patients. This study subjected a range of contemporary lateral fibular plates to a series of mechanical tests designed to reveal performance differences. Methods: Forty fresh frozen lower extremities were divided into 4 groups. A Weber B distal fibula fracture was simulated with an osteotomy and stabilized using 1 of 4 plate systems: a standard Synthes one-third tubular plate with interfragmentary lag screw, a Synthes LCP locking plate with lag screw, an Orthohelix MaxLock Extreme low-profile locking plate with lag screw, or a TriMed Sidewinder nonlocking plate. Controlled monotonic bending and cyclic torsional loading were applied and bending stiffness, torsional stiffness, and fracture site motion were quantified. Resistance to cyclic torsional loading was determined by quantifying the number of loads withstood before excessive rotation occurred. Correlation between bone mineral density and each of the mechanical measures was determined. Results: There was no difference in angulation or bending stiffness between plates. All plates except the LCP showed greater lateral deflection than in the other bending directions. Bending stiffness was lowest in lateral distal fragment deflection for all 4 plates. There was a positive correlation between bone mineral density and bending stiffness for all plate types. There was no difference in fracture site rotation between plate types in internal or external torsion, but internal rotation of the distal fragment consistently exceeded external rotation. Torsional stiffness in external rotation exceeded stiffness in internal rotation in nearly all specimens. LCP plates performed relatively poorly under cyclic torsion. Conclusions: Significant differences in plate performance were not demonstrated. The effects of bone quality variability and differences in interfragmentary screw purchase resulted in data dispersion that confounded absolute ranking of plate performance. Clinical Relevance: Identification of an optimal lateral fibular plating system has the potential to improve the clinical outcome of malleolar fracture fixation, particularly when patient conditions are unfavorable.

Fate of combat nerve injury.

Objective: Assess a cohort of combat-related type III open tibia fractures with peripheral nerve injury to determine the injury mechanism and likelihood for recovery or improvement in nerve function. Design: Retrospective study. Setting: Three military medical centers. Patients and Participants: Out of a study cohort of 213 type III open tibia fractures, 32 fractures (in 32 patients) with a total of 43 peripheral nerve injuries (peroneal or tibial) distal to the popliteal fossa met inclusion criteria and were available for follow-up at an average of 20 months (range, 2–48 months). Main Outcome Measurements: Clinical assessment of motor and sensory nerve improvement. Results: There was a 22% incidence of peripheral nerve injury in the study cohort. At an average follow-up of 20 months (range, 2–48 months), 89% of injured motor nerves were functional, whereas the injured sensory nerves had function in 93%. Fifty percent and 27% of motor and sensory injuries demonstrated improvement, respectively (P = 0.043). With the numbers available, there was no difference in motor or sensory improvement based on mechanism of injury, fracture severity or location, soft tissue injury, or specific nerve injured. In the subset of patients with an initially impaired sensory examination, full improvement was related to fracture location (P = 0.0164). Conclusions: Type III open tibia fractures sustained in combat are associated with a 22% incidence of peripheral nerve injury, and the majority are due to multiple projectile penetrating injury. Despite the severe nature of these injuries, the vast majority of patients had a functional nerve status by an average of 2-year follow-up. Based on these findings, discussions regarding limb salvage and amputation should not be overly influenced by the patients peripheral nerve status. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Calcaneal “Z” Osteotomy Effect on Hindfoot Varus After Triple Arthrodesis in a Cadaver Model

Background: Triple arthrodesis involves subtalar, talonavicular, and calcaneocuboid joint fusion and is performed to relieve pain and correct deformity. Complications include malunion resulting in equinovarus and lateral column overload, which can lead to painful callosities and stress fractures. This study quantified the effectiveness of a closing-wedge calcaneal “Z” osteotomy for correction of the varus condition and reduction of abnormal loading of the lateral border of the foot. Methods: Ten fresh-frozen feet were used. Angle meters were attached to the calcaneus and second cuneiform to measure hindfoot and midfoot varus, and pressure sensors were placed under the first and fifth metatarsal heads to document loading of the borders of the foot. Tensile loads were applied to ten extrinsic tendons and the Achilles tendon while an 1187 N axial foot load was applied. Calcaneus and second cuneiform coronal plane angles and medial and lateral plantar pressures were measured initially, after triple fusion-induced varus, and after “Z” osteotomy. Results: The calcaneal “Z” osteotomy had no significant corrective effect, with hindfoot alignment virtually identical before and after the procedure under the described foot loading conditions. Similarly, second cuneiform inclination, representative of midfoot alignment, showed no change from the osteotomy. Medial and lateral peak plantar pressures after calcaneal “Z” osteotomy did not differ from those measured after varus triple fusion. Conclusion: In this cadaver model of varus malunited triple arthrodesis, the closing-wedge calcaneal “Z” osteotomy was ineffective for correction of bone alignment and lateral forefoot overloading under the tested conditions. Clinical Relevance: The results provide additional information on which to base treatment after triple arthrodesis with varus malunion.

Effect of increased weight on ankle mechanics and spatial temporal gait mechanics in healthy controls.

Background: Ankle osteoarthritis has been associated with trauma, instability, and inflammatory arthritis. Limited literature exists examining the effect of body weight on ankle joint loading. The purpose of this study was to examine the relationship between increased weight and gender on ankle kinematics and kinetics. Methods: Fifty-three (28 male, 25 female) subjects were recruited for the study. All subjects underwent a standard level walking gait analysis in four different weight conditions (normal, 10%, 15%, and 20% increased body weight). Testing order was randomized. A series of mixed-factor, repeated-measures analyses of variance (weight by gender) were used to determine statistical differences between the groups (p < .05). Results: Walking speed was not significantly different between gender or weight conditions. No significant differences existed for step length, step time, stride length, swing time, or sagittal plane ankle kinematics and kinetics. A significant increase in plantarflexion moment existed for the males (p < .05). The peak plantarflexion moment increased as weight increased. Single support time (p = .042) was significantly different between the no weight and the 15% and 20% increased weight conditions. In addition, double support time was significantly longer in the males compared with females (p < .001) and significantly increased for each weight condition (p < .001). Conclusion: Increasing weight alters spatial temporal mechanics and sagittal plane ankle kinetics in a healthy control population. The effect of increasing weight appears to be similar between genders. Clinical Relevance: The findings of the present study may be relevant for future studies to assess the role of weight as a potential covariate on postoperative outcomes and gait mechanics.

Gastrocnemius Recession: A Panacea for What Ails the Foot and Ankle

In recent years, there seems to be a trend toward performing large numbers of gastrocnemius recessions for a variety of pathological conditions of the foot and ankle. Whether it be as part of a complex flat or cavus foot reconstruction or to improve dorsiflexion, to offload forefoot pressures when treating diabetic ulcers, or, in the case of this paper, to decrease tension across the Achilles to treat tendinopathy, there is no doubt that the gastrocnemius recession has emerged as a vital tool in the armamentarium of the foot and ankle surgeon. While there are several case series that demonstrate promising results with regard to pain relief after gastrocnemius recession for Achilles tendinopathy1,2, the literature has not been as defined regarding the effect on plantar-flexion strength postoperatively3,4. Some of these limitations include small sample size, retrospective …