Exploring relationships among multi-disciplinary assessments for knee joint health in service members with traumatic unilateral lower limb loss: a two-year longitudinal investigation.

Motivated by the complex and multifactorial etiologies of osteoarthritis, here we use a comprehensive approach evaluating knee joint health after unilateral lower limb loss. Thirty-eight male Service members with traumatic, unilateral lower limb loss (mean age = 38 yr) participated in a prospective, two-year longitudinal study comprehensively evaluating contralateral knee joint health (i.e., clinical imaging, gait biomechanics, physiological biomarkers, and patient-reported outcomes); seventeen subsequently returned for a two-year follow-up visit. For this subset with baseline and follow-up data, outcomes were compared between timepoints, and associations evaluated between values at baseline with two-year changes in tri-compartmental joint space. Upon follow-up, knee joint health worsened, particularly among seven Service members who presented at baseline with no joint degeneration (KL = 0) but returned with evidence of degeneration (KL ≥ 1). Joint space narrowing was associated with greater patellar tilt (r[12] = 0.71, p = 0.01), external knee adduction moment (r[13] = 0.64, p = 0.02), knee adduction moment impulse (r[13] = 0.61, p = 0.03), and CTX-1 concentration (r[11] = 0.83, p = 0.001), as well as lesser KOOSSport and VR-36General Health (r[16] = - 0.69, p = 0.01 and r[16] = - 0.69, p = 0.01, respectively). This longitudinal, multi-disciplinary investigation highlights the importance of a comprehensive approach to evaluate the fast-progressing onset of knee osteoarthritis, particularly among relatively young Service members with lower limb loss.

A Comprehensive, Multidisciplinary Assessment for Knee Osteoarthritis Following Traumatic Unilateral Lower Limb Loss in Service Members.

INTRODUCTION: Knee osteoarthritis (KOA) is a primary source of long-term disability and decreased quality of life (QoL) in service members (SM) with lower limb loss (LL); however, it remains difficult to preemptively identify and mitigate the progression of KOA and KOA-related symptoms. The objective of this study was to explore a comprehensive cross-sectional evaluation, at the baseline of a prospective study, for characterizing KOA in SM with traumatic LL. MATERIALS AND METHODS: Thirty-eight male SM with traumatic unilateral LL (23 transtibial and 15 transfemoral), 9.5 ± 5.9 years post-injury, were cross-sectionally evaluated at initial enrollment into a prospective, longitudinal study utilizing a comprehensive evaluation to characterize knee joint health, functionality, and QoL in SM with LL. Presences of medial, lateral, and/or patellofemoral articular degeneration within the contralateral knee were identified via magnetic resonance imaging(for medically eligible SM; Kellgren-Lawrence Grade [n = 32]; and Outerbridge classification [OC; n = 22]). Tri-planar trunk and pelvic motions, knee kinetics, along with temporospatial parameters, were quantified via full-body gait evaluation and inverse dynamics. Concentrations of 26 protein biomarkers of osteochondral tissue degradation and inflammatory activity were identified via serum immunoassays. Physical function, knee symptoms, and QoL were collected via several patient reported outcome measures. RESULTS: KOA was identified in 12 of 32 (37.5%; KL ≥ 1) SM with LL; however, 16 of 22 SM presented with patellofemoral degeneration (72.7%; OC ≥ 1). Service members with versus without KOA had a 26% reduction in the narrowest medial tibiofemoral joint space. Biomechanically, SM with versus without KOA walked with a 24% wider stride width and with a negative correlation between peak knee adduction moments and minimal medial tibiofemoral joint space. Physiologically, SM with versus without KOA exhibited elevated concentrations of pro-inflammatory biomarker interleukin-7 (+180%), collagen breakdown markers collagen II cleavage (+44%), and lower concentrations of hyaluronic acid (-73%) and bone resorption biomarker N-telopeptide of Type 1 Collagen (-49%). Lastly, there was a negative correlation between patient-reported contralateral knee pain severity and patient-reported functionality and QoL. CONCLUSIONS: While 37.5% of SM with LL had KOA at the tibiofemoral joint (KL ≥ 1), 72.7% of SM had the presence of patellofemoral degeneration (OC ≥ 1). These findings demonstrate that the patellofemoral joint may be more susceptible to degeneration than the medial tibiofemoral compartment following traumatic LL.

Fluid collections in amputations are not indicative or predictive of infection.

BACKGROUND: In the acute postoperative period, fluid collections are common in lower extremity amputations. Whether these fluid collections increase the risk of infection is unknown. QUESTIONS/PURPOSES: The purposes of this study were to determine (1) the percentage of patients who develop postoperative fluid collections in posttraumatic amputations and the natural course of the collection; (2) whether patients who develop these collections are at increased risk for infection; and to ask (3) are there objective clinical or radiologic signs that are associated with likelihood of infection when a fluid collection is present? METHODS: We performed a review of all 300 patients injured in combat operations who sustained at least one major lower extremity amputation (at or proximal to the tibiotalar joint) and were treated definitively at our institution between March 2005 and April 2009. We segregated the groups based on whether cross-sectional imaging was performed less than 3 months (early group) after closure, greater than 3 months (late group) after closure, or not at all (control group, baseline frequency of infection). Our primary study cohort where those patients with a fluid collection in the first three months. The clinical course was reviewed and the primary outcome was a return to the operating room for irrigation and débridement with positive cultures. For those patients with cross-sectional imaging, we also collected objective clinical parameters within 24 hours of the scan (white blood cell count, maximum temperature, presence of bacteremia, tachycardia, oxygen desaturation), extremity examination (presence of erythema, warmth, and/or drainage), and characteristics of the fluid collections seen (size of the fluid collection, enhancement, complexity (simple versus loculated), surrounding edema, skin changes, tract formation, presence of air, and changes within the bone itself). The presence of a fluid collection on imaging was analyzed to determine whether it was associated with infection. We further analyzed clinical parameters, objective physical examination findings at the extremity, and characteristics of the fluid collection to determine if there were other parameters associated with infection. RESULTS: Over half (55%) of the limbs demonstrated fluid collection in the early postoperative period and the prevalence decreased in the late group (11%; p = 0.001). There was no association between the presence of a fluid collection and infection. However, there was an association between objective clinical signs at the extremity (erythema and/or drainage) and infection (p < 0.001) in our primary study cohort. CONCLUSIONS: Fluid collections are common in combat-related amputations in the immediate postoperative period and become smaller and less frequent over time. In the absence of extremity erythema and wound drainage, imaging of a residual limb to evaluate for the presence of a fluid collection appears to be of little clinical use.

From the radiologic pathology archives: ewing sarcoma family of tumors: radiologic-pathologic correlation.

The Ewing sarcoma family of tumors includes osseous Ewing sarcoma, extraskeletal Ewing sarcoma, primitive neuroectodermal tumor, and Askin tumor. They share a karyotype abnormality with translocation involving chromosomes 11 and 22. Histologically, these lesions demonstrate crowded sheets of small round blue cells. Imaging features of osseous Ewing sarcoma often suggest the diagnosis, with aggressive long-bone destruction in the metadiaphysis of an adolescent or young adult and an associated soft-tissue mass. Focal areas of cortical destruction are frequent, allowing continuity between the intraosseous and extraosseous components. This continuity is also commonly seen as subtle channels extending through the cortex at computed tomography or magnetic resonance (MR) imaging, a finding that reflects the underlying pathologic appearance. Extraskeletal Ewing sarcoma commonly demonstrates a nonspecific radiologic appearance of a large soft-tissue mass affecting the paraspinal region or lower extremity. Askin tumor represents extraskeletal Ewing sarcoma involving the chest wall. Imaging typically reveals a large pleural-based mass and associated pleural effusion. Treatment of these tumors is usually a combination of neoadjuvant chemotherapy followed by surgical resection, which may be supplemented with radiation therapy. Imaging, particularly MR, is also vital to evaluate response to neoadjuvant therapy, direct surgical resection, and detect local recurrence or metastatic disease.