Clinical Outcomes After Extracorporeal Shock Wave Therapy for Chronic Plantar Fasciitis in a Predominantly Active Duty Population.

Chronic plantar fasciitis is a common cause of foot pain, with conservative treatment providing relief for most patients. However, because of the common occurrence of this pathology, this leaves many patients dissatisfied. The purpose of the present study was to determine the effectiveness of extracorporeal shock wave therapy (ESWT) to treat chronic plantar fasciitis (PF) in a largely active duty population. A review of 82 patients (115 heels) who had undergone ESWT for chronic PF was performed. Outcome data were obtained by patient telephone interviews. All ESWT was conducted at 24 kV for 2000 shocks. Of the 82 patients (115 heels), 76 (93%; 111 heels) agreed to participate. Their mean age was 42 ± 10 years, with 41 males (54%) and 35 females (46%). The mean follow-up period was 42 ± 22 months. Of the patients, 73.6% were active duty military personnel. The mean preoperative pain score of 7.8 ± 2 had improved to 2.5 ± 2 at the last follow-up visit (p <.0001). Active duty patients reported a mean improvement in pain of 4.8 ± 3 compared with 6.8 ± 3 in non-active duty patients (p = .005). Of the 76 patients, 75 (98%) underwent 1 ESWT session, and 1 (2%) requiring 2 sessions. Overall, 74% of patients rated the outcome of their procedure as either good or excellent, with 87% stating that ESWT was successful. Ten patients (18%) left the military because of continued foot pain, with 76% able to return to running. For patients with chronic PF, these results support the use of ESWT to relieve pain in >85% of patients, with a preponderance for better pain relief in patients who are not active duty military personnel.

Nitinol Staple Use in Primary Arthrodesis of Lisfranc Fracture-Dislocations.

BACKGROUND: Primary arthrodesis of Lisfranc fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion. Nitinol staple use has recently proliferated in midfoot arthrodesis. The purpose of this study is to examine the union rate of primary arthrodesis of acute Lisfranc fracture-dislocations treated with nitinol staples compared with traditional plate-and-screw fixation. The secondary objective is to assess the difference in operative times and reoperation rates. METHODS: Midfoot fracture-dislocations treated with primary arthrodesis by 7 foot and ankle orthopaedic surgeons were reviewed. Of 160 eligible patients, 121 patients (305 joints) met the required 4-month minimum radiographic follow-up. Radiographic outcomes were analyzed at the individual joint level. Each joint was classified as either staples alone (45 patients, 154 joints), staples plus plates and screws (hybrid) (45 patients, 40 joints), or plates and screws alone (31 patients, 111 joints). The primary outcome was arthrodesis union at each joint fused. RESULTS: Nonunion was more common (9.0%, 10/111) among joints fixed with plate and screws than with hybrid (2.5%, 1/40) or staples only (1.3%, 2/154) (P = .0085). Multivariable regression demonstrated that autograft use was independent associated with union (P = .0035) and plate-and-screw only fixation was an independent risk factor for nonunion (P = .0407). Median operating room and tourniquet times were shorter for hybrid (92 and 83 minutes) and staple only (67 and 63 minutes) constructs compared to plate-and-screw only fixation (105 and 95 minutes) (P ≤ .0001 and .0003). There was no difference in reoperation rates among patients with different fixation types. CONCLUSION: We found that use of nitinol compression staple and bone autograft in primary arthrodesis of Lisfranc and midfoot fracture-dislocations was associated with both improved union rates and shorter tourniquet and operative times compared to traditional plate-and-screw fixation techniques. LEVEL OF EVIDENCE: Level III, therapeutic.

Prospective Clinical and Computed Tomography Evaluation of Calcaneus Fractures Treated Through Sinus Tarsi Approach.

Background: The traditional lateral extensile approach to the calcaneus allows for excellent visualization but is associated with high wound complication rates. The sinus tarsi approach has been shown to produce similar radiographic outcomes with much lower rates of wound complications. The purpose of this study is to prospectively determine clinical and radiographic outcomes in calcaneus fractures treated with a sinus tarsi approach. Methods: Twenty-nine patients with 30 calcaneus fractures underwent operative fixation through a sinus tarsi approach and were prospectively evaluated. Routine pre- and postoperative radiographs were obtained, in addition to computed tomography (CT) scans at 6 weeks and 12 months after surgery. Patient-reported outcomes including American Orthopaedic Foot & Ankle Society (AOFAS) score, visual analog scale (VAS) pain score, Veterans Rand 12-Item Health Survey (VR-12), and Foot Functional Index (FFI) were recorded. Patients were followed for a minimum of 1 year postoperation. Results: Twenty-one patients with 22 calcaneus fractures completed 1 year of follow-up. At 12 months postoperation, 20 of 22 patients (91%) had 0 to 2 mm of fracture displacement at the posterior facet on CT scans whereas 2 of 22 patients had 2 to 4 mm of fracture displacement. There was no significant change in posterior facet fracture displacement comparing 6-week and 12-month postoperative CT scans (P > .99). Mean postoperative Bohler angle was 26.1 degrees compared to 13.2 degrees preoperatively. All patients had complete union of fracture site. There were no major wound complications. Four of 22 patients (18.2%) had minor wound complications. AOFAS, FFI, and VAS pain scores improved postoperatively but were not found to correlate with Bohler angle or critical angle of Gissane. Conclusion: We found that in select patients excellent anatomic alignment and good clinical outcomes with low wound complication rates can be achieved when fixing calcaneus fractures through the sinus tarsi approach. Level of Evidence: Level II, prospective cohort study.

Special topics.

Concerning the past decade of war, three special topics were examined at the Extremity War Injuries VII Symposium. These topics included the implementation of tourniquets and their effect on decreasing mortality and the possibility of transitioning the lessons gained to the civilian sector. In addition, the training of surgeons for war as well as residents in a wartime environment was reviewed.

Combat Wound Initiative program.

The Combat Wound Initiative (CWI) program is a collaborative, multidisciplinary, and interservice public-private partnership that provides personalized, state-of-the-art, and complex wound care via targeted clinical and translational research. The CWI uses a bench-to-bedside approach to translational research, including the rapid development of a human extracorporeal shock wave therapy (ESWT) study in complex wounds after establishing the potential efficacy, biologic mechanisms, and safety of this treatment modality in a murine model. Additional clinical trials include the prospective use of clinical data, serum and wound biomarkers, and wound gene expression profiles to predict wound healing/failure and additional clinical patient outcomes following combat-related trauma. These clinical research data are analyzed using machine-based learning algorithms to develop predictive treatment models to guide clinical decision-making. Future CWI directions include additional clinical trials and study centers and the refinement and deployment of our genetically driven, personalized medicine initiative to provide patient-specific care across multiple medical disciplines, with an emphasis on combat casualty care.

Combat foot and ankle trauma.

Injury to the lower extremity is common in the current conflicts, often severely affecting the foot and ankle. Secondary to continued surgical advances, many lower extremities are able to undergo limb salvage procedures. However, scoring systems still do not reliably predict which patient will be best served with an amputation or limb salvage. Because of this, limb salvage should be attempted whenever possible, awaiting definitive treatment at a later time. Treatment begins at the time and location of injury with aggressive debridement, with reduction and external fixation of fractures when possible. Serial debridements are often necessary until the traumatic wounds are ready for coverage or closure. Forefoot injuries are treated with varying techniques depending on the location of the injury. Amputation of toes and/or flap coverage is often necessary secondary to tenuous soft tissues. Midfoot injury patterns are complex, possibly requiring arthrodesis, antibiotic spacers, soft tissue coverage, and thin-wire ring external fixation. Hindfoot or calcaneal injuries are often the most difficult to treat, requiring extraordinary efforts to salvage a viable limb. Early reduction of the remaining fragments and percutaneous fixation are often followed by arthrodesis of the subtalar joint. Fractures of the calcaneus requiring free soft tissue coverage frequently lead to amputation. Blast injuries to the lower extremity are severe injuries. They are frequently associated with fractures to multiple levels. Early elective amputation at the level V treatment center is frequently performed. When limb salvage is performed, basic principles must be followed to optimize treatment.

Damage control orthopaedics: an in-theater perspective.

Damage control orthopaedics is well described for civilian trauma. However, significant differences exist for combat-related extremity trauma. Military combat casualty care is defined by levels of care. Each level of care has a specific role in the care of the wounded patient. Because of lack of equipment, austere environments, and significant soft tissue wounds, most combat fractures are stabilized with external fixation even in a stable patient, unlike civilian trauma. External fixation allows for rapid stabilization of fractures and easy access to wounds and requires little shelf stock of implants. Unique situations exist in the care of the combat-injured casualty, which include working in an isolated facility, caring for enemy combatants, large soft tissue wounds, and the need to rapidly transport patients out of the theater of operations.

Lower extremity combat-related amputations.

Since the onset of combat activity in Iraq and Afghanistan, there have been over 1100 major limb amputations among United States service members. With a sustained military presence in the Middle East, continued severe lower extremity trauma is inevitable. For this reason, combat surgeons must understand the various amputation levels as well as the anatomic and technical details that enable an optimal functional outcome. These amputations are unique and usually result from blast mechanisms and are complicated by broad zones of injury with severe contamination and ongoing infection. The combat servicemen are young, previously healthy, and have the promising potential to rehabilitate to very high levels of activity. Therefore, every practical effort should be made to perform sound initial and definitive trauma-related amputations so that these casualties may return to their highest possible level of function.

Multisite Evaluation of a Custom Energy-Storing Carbon Fiber Orthosis for Patients with Residual Disability After Lower-Limb Trauma.

BACKGROUND: The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a custom energy-storing carbon fiber ankle-foot orthosis developed for lower-extremity trauma patients. Studies conducted at the military treatment facility where the IDEO was developed demonstrated benefits of the IDEO when used with the Return to Run Physical Therapy (RTR PT) program. The current study was designed to determine if results could be replicated at other military treatment facilities and to examine whether early performance gains in patient-reported functional outcomes remained at 12 months. METHODS: Study participants included service members who had functional deficits that interfered with daily activities at least 1 year after a traumatic unilateral lower-extremity injury at or below the knee. Participants were evaluated before receiving the IDEO, immediately following completion of RTR PT, and at 6 and 12 months. Agility, strength/power, and speed were assessed using well-established performance tests. Self-reported function was measured using the Short Musculoskeletal Function Assessment (SMFA). The Orthotics and Prosthetics Users' Survey was administered to assess satisfaction with the IDEO. Of 87 participants with complete baseline data, 6 did not complete any physical therapy and were excluded from the analysis. Follow-up rates immediately following completion of the RTR PT and at 6 and 12 months were 88%, 75%, and 79%, respectively. RESULTS: Compared with baseline, improvement at completion of RTR PT was observed in all but 1 performance test. SMFA scores for all domains except hand and arm function were lower (improved function) at 6 and 12 months. Satisfaction with the IDEO was high following completion of RTR PT, with some attenuation at the time of follow-up. CONCLUSIONS: This study adds to the evidence supporting the efficacy of the IDEO coupled with RTR PT. However, despite improvement in both performance and self-reported functioning, deficits persist compared with population norms. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Bioartificial dermal substitute: a preliminary report on its use for the management of complex combat-related soft tissue wounds.

OBJECTIVE: To report our institutional experience with the use of a bioartificial dermal substitute (Integra) combined with subatmospheric pressure [vacuum-assisted closure (VAC)] dressings followed by delayed split-thickness skin grafting for management of complex combat-related soft tissue wounds secondary to blast injuries. DESIGN: Retrospective review of patients treated December 2004 through November 2005. SETTING: Military treatment facility. PATIENTS/PARTICIPANTS: Integra grafting was performed 18 times in 16 wounds at our institution. Indications for Integra placement were wounds not amenable to simple split-thickness skin grafting, specifically those with substantial exposed bone and/or tendon. INTERVENTION: Patients underwent an average of 8.5 irrigation and debridement procedures and concurrent VAC dressings prior to placement of the Integra. Following Integra grafting, all patients were managed with VAC dressings, changed every 3 to 4 days at the bedside or in clinic, with subsequent split-thickness skin grafting an average of 19 days later. MAIN OUTCOME MEASUREMENTS: The mechanism and date of injury, size of residual soft tissue deficit, indication for Integra placement, number of irrigation and debridement procedures prior to Integra placement, days from injury to Integra placement, days from Integra placement to split-thickness skin grafting, and clinical outcome were recorded. RESULTS: Integra placement and subsequent skin grafting was successful in achieving durable and cosmetic definitive coverage in 15 of 16 wounds with two of these patients requiring repeat Integra application. Two patients with difficult VAC dressing placement had early Integra graft failure but successfully healed following repeated Integra application and skin grafting. CONCLUSIONS: Bioartificial dermal substitute grafting, when coupled with subatmospheric dressing management and delayed split-thickness skin grafting, is an effective technique for managing complex combat-related soft tissue wounds with exposed tendon. This can potentially lessen the need for local rotational or free flap coverage.

Spherical ceramic interpositional arthroplasty for basal fourth and fifth metatarsal arthritis.

BACKGROUND: Arthrosis of the fourth and fifth tarsometatarsal joints is difficult to treat. Arthrodesis is both difficult to achieve as well as disabling. Tendon interpositional arthroplasty has been performed with some success. A new technique using ceramic ball interpositional arthroplasty was evaluated. METHODS: Between 2001 and 2003, 13 patients in whom nonoperative treatment had failed had resection arthroplasty of the base of the fourth or fifth metatarsals with ceramic ball interposition (Orthosphere, Wright Medical Technology, Arlington, Tennessee). Patients were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Scale, a visual analogue scale, a satisfaction index, physical examination, and radiographs. RESULTS: At an average 34-months followup, 11 of the 13 patients were available for evaluation. The five men and six women had an average age of 48 years. Seven patients reported a traumatic etiology. Average postoperative AOFAS score was 53 points, an 87% improvement over preoperative values. Visual analogue scale pain improved 42%. All 11 patients were satisfied and would undergo the operation again. One of the patients demonstrated subsidence of the implant into the cuboid but continued to have improvement in symptoms. To date there have been no implant dislocations. Three of the 11 patients had differential injections before surgery. CONCLUSIONS: Lateral column tarsometatarsal interpositional arthroplasty is an effective salvage operation for lateral column midfoot arthrosis and should be considered in this patient population. The use of the ceramic ball allows a technically simple procedure and rapid recovery.

Severe Stage 2: Fuse or Reconstruct.

Stage II posterior tibial tendon dysfunction encompasses a wide range of patients with varying degrees of deformity and function. The spectrum of patients can be difficult to treat with a single surgical approach, as evidenced by the wide range of techniques present in the literature. Severity of the deformity, patient functional level, age, and comorbidities must be considered to determine the best course of treatment. This article examines when fusion versus reconstruction is the appropriate treatment of patients with severe stage II posterior tibial tendon dysfunction and its subclassifications.

Return to Play Following Ankle Sprain and Lateral Ligament Reconstruction.

Ankle sprains are the most common musculoskeletal injury occurring during athletics. Proper initial treatment with supportive pain control, limited immobilization, early return to weight bearing and range of motion, and directed physical therapy are essential for preventing recurrent injury. Reconstruction of the lateral ligaments is indicated for patients with continued instability and dysfunction despite physical therapy. Return to athletic activity should be reserved for athletes who have regained strength, proprioception, and range of motion of the injured ankle. Athletes with a history of an ankle sprain should be prophylactically braced or tapped to reduce risk of recurrent injury.

Solitary epiphyseal enchondromas.

BACKGROUND: Enchondromas originating in the epiphyses of long bones are rare. The purpose of the present study was to evaluate the prevalence as well as the radiographic and clinical characteristics of epiphyseal enchondromas among patients who had been referred to the Armed Forces Institute of Pathology and Walter Reed Army Medical Center. METHODS: We performed a retrospective review of 761 patients who had been referred to our two institutions over an approximately fifty-five-year period and who received a final diagnosis of enchondroma. All lesions had been biopsied, and the pathological diagnosis had been confirmed. Lesions of the hands, feet, or axial skeleton (253 patients) as well as lesions that appeared to originate in the metaphysis or diaphysis (475 patients) were excluded. Only enchondromas of the long bones that originated in the epiphysis were analyzed. The study group included thirty-three patients (twenty male patients and thirteen female patients) with a mean age of 26.7 years, including eleven patients with open physes. We performed additional descriptive analyses with regard to patient age, gender, lesion location, clinical presentation, and treatment as well as an extensive radiographic analysis. RESULTS: The most common locations were the proximal part of the humerus (ten lesions; 30%) and the distal part of the femur (six lesions; 18%). The most common presenting symptom was pain (twenty-three patients). Radiographic analysis demonstrated extensive matrix mineralization in association with twenty-three lesions. Twenty-eight of the thirty-three lesions were geographically well defined; of these, twenty-one had sclerotic borders, and seven did not. Although all lesions were centered and were predominantly located within the epiphysis, twenty of the thirty-three lesions demonstrated radiographic evidence of metaphyseal extension, including four of the eleven lesions in patients with open physes. Twenty-four lesions extended into the subchondral bone. The mean size of the thirty-three enchondromas in greatest radiographic dimension was 2.7 cm (range, 1.1 to 4.9 cm). Twenty-six of the thirty-three lesions were amenable to surgical treatment with curettage with or without bone-grafting, with only one recurrence. With the limited follow-up available, no lesion underwent sarcomatous degeneration. CONCLUSIONS: Epiphyseal enchondromas are rare lesions. Although their biologic behavior appears to mirror that of conventional metaphyseal enchondromas, their proximity to the joint space may lead to more frequent painful symptoms, a propensity for physeal involvement, and the need for earlier definitive surgical intervention.

Osteoporosis and anterior femoral notching in periprosthetic supracondylar femoral fractures: a biomechanical analysis.

BACKGROUND: This biomechanical study was designed to evaluate the predictive ability of dual-energy x-ray absorptiometry, cortical bone geometry as determined with computed tomography, and radiography in the assessment of torsional load to failure in femora with and without notching. METHODS: Thirteen matched pairs of cadaveric femora were randomized into two groups: a notched group, which consisted of femora with a 3-mm anterior cortical defect, and an unnotched group of controls. Each pair then underwent torsional load to failure. The ability of a number of measures to predict femoral torsional load to failure was assessed with use of regression analysis. These measures included dual-energy x-ray absorptiometry scans of the proximal and the distal part of the femur, geometric measures of both anterior and posterior cortical thickness as well as the polar moment of inertia of the distal part of the femur as calculated on computed tomography scans, and the Singh osteoporosis index as determined on radiographs. RESULTS: The torsional load to failure averaged 98.9 N-m for the notched femora and 143.9 N-m for the controls; the difference was significant (p < 0.01). Although several variables correlated with torsional load to failure, distal femoral bone-mineral density demonstrated the highest significant correlation (r = 0.85; p < 0.001). Moreover, multiple regression analysis showed that a combination of distal femoral bone-mineral density and polar moment of inertia calculated with the posterior cortical thickness (adjusted r (2) = 0.79; p < 0.001) had the strongest prediction of torsional load to failure in the notched group. The addition of other measures of cortical bone geometry, proximal femoral bone-mineral density, or radiographic evidence of osteopenia did not significantly increase the model's predictive ability. CONCLUSIONS: Femoral notching significantly decreases distal femoral torsional load to failure and is best predicted by a combination of the measures of distal femoral bone-mineral density and polar moment of inertia. Together, these values account for the amount of bone mass present and the stability provided by the cortical shell architecture.

Reoperation after combat-related major lower extremity amputations.

OBJECTIVE: Complication rates leading to reoperation after trauma-related amputations remain ill defined in the literature. We sought to identify and quantify the indications for reoperation in our combat-injured patients. DESIGN: Retrospective review of a consecutive series of patients. SETTING: Tertiary Military Medical Center. PATIENTS/PARTICIPANTS: Combat-wounded personnel sustaining 300 major lower extremity amputations from Operations Iraqi and Enduring Freedom from 2005 to 2009. INTERVENTION: We performed a retrospective analysis of injury and treatment-related data, complications, and revision of amputation data. Prerevision and postrevision outcome measures were identified for all patients. MAIN OUTCOME MEASUREMENTS: The primary outcome measure was the reoperation on an amputation after a previous definitive closure. Secondary outcome measures included ambulatory status, prosthesis use, medication use, and return to duty status. RESULTS: At a mean follow-up of 23 months (interquartile range: 16-32), 156 limbs required reoperation leading to a 53% overall reoperation rate. Ninety-one limbs had 1 indication for reoperation, whereas 65 limbs had more than 1 indication for reoperation. There were a total of 261 distinct indications for reoperation leading to a total of 465 additional surgical procedures. Repeat surgery was performed semiurgently for postoperative wound infection (27%) and sterile wound dehiscence/wound breakdown (4%). Revision amputation surgery was also performed electively for persistently symptomatic residual limbs due to the following indications: symptomatic heterotopic ossification (24%), neuromas (11%), scar revision (8%), and myodesis failure (6%). Transtibial amputations were more likely than transfemoral amputations to be revised due to symptomatic neuromata (P = 0.004; odds ratio [OR] = 3.7; 95% confidence interval [95% CI] = 1.45-9.22). Knee disarticulations were less likely to require reoperation when compared with all other amputation levels (P = 0.0002; OR = 7.6; 95% CI = 2.2-21.4). CONCLUSIONS: In our patient population, reoperation to address urgent surgical complications was consistent with previous reports on trauma-related amputations. Additionally, persistently symptomatic residual limbs were common and reoperation to address the pathology was associated with an improvement in ambulatory status and led to a decreased dependence on pain medications.

Risk factors for infection and amputation following open, combat-related calcaneal fractures.

BACKGROUND: High-energy open calcaneal fractures are severe injuries complicated by high rates of infection, uncertain functional outcomes, and frequent need for later amputation. METHODS: We conducted a retrospective review of 102 consecutive combat-related open calcaneal fractures. Patient demographics, injury mechanisms, fracture and wound characteristics, associated fractures, and methods of fracture fixation were reviewed to determine risk factors for eventual amputation or infection. RESULTS: Eighty-nine patients, with a mean age of twenty-six years, sustained 102 open calcaneal fractures (thirteen bilateral). After a mean follow-up of four years (range, five to ninety-two months), 42% (forty-three limbs) underwent amputation. A delayed amputation (more than twelve weeks from the time of injury) was performed in 15% (fifteen) of 102 open calcaneal fractures. In a multivariate Cox proportional-hazards survival model with time to amputation as the end point, the blast mechanism of injury, plantar wound location, larger size of open wound (in square centimeters), and escalating Gustilo and Anderson classification types (p < 0.05 for all) were predictive of eventual amputation. At the time of the final follow-up, patients who had undergone amputation had lower visual analogue scale scores for pain (2.1 compared with 4.0; p < 0.0001) and higher Tegner activity levels (5.4 compared with 3.5; p < 0.0001) than limb salvage patients. CONCLUSIONS: Lower-extremity amputation following open calcaneal fractures is predicted by the injury mechanism, wound location and size, and open fracture type and severity. After short-term follow-up, patients with open calcaneal fractures eventually requiring amputation exhibit improved pain and activity levels compared with patients with continued, ostensibly successful limb salvage.

Comparison of functional outcomes following bridge synostosis with non-bone-bridging transtibial combat-related amputations.

BACKGROUND: The prevalence of penetrating wartime trauma to the extremities has increased in recent military conflicts. Substantial controversy remains in the orthopaedic and prosthetic literature regarding which surgical technique should be performed to obtain the most functional transtibial amputation. We compared self-reported functional outcomes associated with two surgical techniques for transtibial amputation: bridge synostosis (modified Ertl) and non-bone-bridging (modified Burgess). METHODS: A review of the prospective military amputee database was performed to identify patients who had undergone transtibial amputation between June 2003 and December 2010 at three military institutions receiving the majority of casualties from the most recent military conflicts; two of those institutions, Walter Reed Army Medical Center and National Naval Medical Center, have since been consolidated. Short Form-36, Prosthesis Evaluation Questionnaire, and functional data questions were completed by twenty-seven modified Ertl and thirty-eight modified Burgess isolated transtibial amputees. RESULTS: The average duration of follow-up after amputation (and standard deviation) was 32 ± 22.7 months, which was similar between groups. Residual limb length was significantly longer in the modified Ertl cohort by 2.5 cm (p < 0.005), and significantly more modified Ertl patients had delayed amputations (p < 0.005). There were no significant differences between groups with regard to any of the Short Form-36 domains or Prosthesis Evaluation Questionnaire subsections. CONCLUSIONS: The modified Ertl and Burgess techniques offer similar functional outcomes in the young, active-duty military population managed with transtibial amputation.