Patterns of firearm related injury in the elderly: A single institution analysis.

BACKGROUND: Firearm-related violence (FRV) is a public health crisis in the United States that impacts individuals across the lifespan. This study sought to investigate patterns of injury and outcomes of firearm-related injury (FRI) in elderly victims and the impact of social determinants of health on this age demographic. METHODS: A retrospective review of the trauma registry at a large Level I center was performed from 2016-2021. Patients over age 18 were included and FRI was defined by ICD 9 and 10 codes. Comparisons were then made between elderly (age > 65 years) and non-elderly (age 18-64 years) victims. The primary outcome was mortality. Secondary outcomes included hospital and intensive care unit length of stay, in-hospital complications and the impact of distressed community index (DCI) and insurance status on discharge disposition. RESULTS: 23,975 patients were admitted for traumatic injury and 4,133 (6 %) were elderly. Of these, 134 had penetrating injuries and 72 (54 %) were FRI. The elderly patients had a median age of 69y and they were predominantly black (50 %) males (85%). Over 75 % had some form of government insurance compared to less than 20% in non-elderly (p<0.001). 33 % of elderly FRIs were self-inflicted compared to only 4 % in the non-elderly cohort and their overall mortality rate was 25 % versus 15 % in non-elderly with FRI (p = 0.038). The median DCI for the non-elderly victims was 72.3 [IQR 53.7-93.1] compared to 63.7 [IQR 33.2-83.6] in the elderly (p < 0.001), however, over 50 % of elderly victims were living in "at risk" or "distressed" communities. CONCLUSION: FRV is a public health crisis across the lifespan and elderly individuals represent a vulnerable subset of patients with unique needs and public health considerations. While many interventions target youth and young adults, it is imperative to not overlook the elderly in injury prevention efforts, particularly self-directed violence. Additionally, given most elderly victims were on government funded insurance and had a higher likelihood of requiring more costly discharge dispositions, new policies should take into consideration the potential financial burden of FRV in the elderly.

Lower extremity vascular injuries caused by firearms have a higher risk of amputation and death compared with non-firearm penetrating trauma.

OBJECTIVE: Firearm injuries have traditionally been associated with worse outcomes compared with other types of penetrating trauma. Lower extremity trauma with vascular injury is a common presentation at many centers. Our goal was to compare firearm and non-firearm lower extremity penetrating injuries requiring vascular repair. METHODS: We analyzed the National Inpatient Sample from 2010 to 2014 for all penetrating lower extremity injuries requiring vascular repair based on International Classification of Diseases, Ninth Revision codes. Our primary outcomes were in-hospital lower extremity amputation and death. RESULTS: We identified 19,494 patients with lower extremity penetrating injuries requiring vascular repair-15,727 (80.7%) firearm injuries and 3767 (19.3%) non-firearm injuries. The majority of patients were male (91%), and intent was most often assault/legal intervention (64.3%). In all penetrating injuries requiring vascular repair, the majority (72.9%) had an arterial injury and 43.8% had a venous injury. Location of vascular injury included iliac (19.3%), femoral-popliteal (60%), and tibial (13.2%) vascular segments. Interventions included direct vascular repair (52.1%), ligation (22.1%), bypass (19.4%), and endovascular procedures (3.6%). Patients with firearm injuries were more frequently younger, black, male, and on Medicaid, with lower household income, intent of assault or legal action, and two most severe injuries in the same body region (P < .0001 for all). Firearm injuries compared with non-firearm injuries were more often reported to be arterial (75.5% vs 61.9%), to involve iliac (20.6% vs 13.7%) and femoral-popliteal vessels (64.7% vs 39.9%), to undergo endovascular repair (4% vs 2.1%), and to have a bypass (22.5% vs 6.5%; P < .05 for all). Firearm-related in-hospital major amputation (3.3% vs 0.8%; P = .001) and mortality (7.6% vs 4.2%; P = .001) were higher compared with non-firearm penetrating trauma. Multivariable analysis showed that injury by a firearm source was independently associated with postoperative major amputation (odds ratio, 4.78; 95% confidence interval, 2.07-11.01; P < .0001) and mortality (odds ratio, 1.74; 95% confidence interval, 1.14-2.65; P = .01). CONCLUSIONS: Firearm injury is associated with a higher rate of amputation and mortality compared with non-firearm injuries of the lower extremity requiring vascular repair. These data can continue to guide public health discussions about morbidity and mortality from firearm injury.

Calculated Decisions: Focused Assessment With Sonography for Trauma (FAST)

Focused Assessment with Sonography for Trauma (FAST) predicts the presence of pericardial or intra-abdominal injury after penetrating or blunt trauma.

Barriers to safe abortion access: uterine rupture as complication of unsafe abortion in a Ugandan girl.

A 15-year-old girl at 18 weeks gestation by the last menstrual period presented to a rural Ugandan healthcare facility for termination of her pregnancy as a result of rape by her uncle. Skilled healthcare workers at the facility refused to provide the abortion due to fear of legal repercussions. The patient subsequently obtained an unsafe abortion by vaginal insertion of local herbs and sharp objects. She developed profuse vaginal bleeding and haemorrhagic shock. She was found to have uterine rupture and emergent hysterectomy was performed. Young and poor women are at high risk of unplanned pregnancy and subsequent mortality during pregnancy and childbirth. Unsafe abortion is a leading and entirely preventable cause of maternal mortality worldwide. Multiple barriers restrict access to safe abortions including social and moral stigma, gender-based power imbalances, inadequate contraceptive use and sexual education, high cost and poor availability, and restrictive abortion laws.

Resource use in pediatric blunt and penetrating trauma.

BACKGROUND: Trauma is one of the leading causes of pediatric morbidity and mortality with significant patient and economic impacts that necessitate constant study. Significant differences in outcomes and resource use exist between blunt and penetrating mechanisms. METHODS: The National Trauma Data Bank was analyzed for patients aged 0-18 y with International Classification of Diseases, 9th Revision injury codes for blunt and penetrating trauma from 2007-2012. Demographic information, causes, treatments, complications, and outcomes were assessed. RESULTS: A total of 748,347 pediatric trauma patients were assessed. Blunt trauma was identified as the cause in 601,898 (80.43%) patients compared with 55,597 (7.4%) patients with penetrating trauma. Blunt trauma patients were younger on average and more likely to be female. Despite having a slightly higher mean injury severity scores, blunt trauma patients had shorter length of stay in the hospital (2.9 versus 4.3 d, P < 0.001), fewer complications (34.8% versus 38.6%, P < 0.001), and a much lower mortality rate (1.3% versus 7.1%, P < 0.001). Blunt trauma patients were more likely to undergo computed tomography scanning but less likely to receive transfusions (1.79% versus 5.5%, P < 0.001) and to undergo exploratory laparotomy (0.9% versus 9.4%, P < 0.001) and thoracotomy (0.07% versus 1.7%, P < 0.001). Variations in outcome and resource use were also noted by age. CONCLUSIONS: Compared with penetrating trauma, blunt trauma is more common and patients have shorter length of stay, less complications, lower mortality, and are less likely to need operative intervention or blood transfusion. Resource use also varied by age.

Use of limited transthoracic echocardiography in patients with traumatic cardiac arrest decreases the rate of nontherapeutic thoracotomy and hospital costs.

OBJECTIVES: Limited transthoracic echocardiography (LTTE) has been introduced as a hemodynamic tool for trauma patients. The aim of this study was to evaluate the utility of LTTE during the evaluation of nonsurviving patients who presented to the trauma bay with traumatic cardiac arrest. METHODS: Approval by the Institutional Review Board was obtained. All nonsurviving patients with traumatic cardiac arrest who reached the trauma bay were evaluated retrospectively for 1 year. Comparisons between groups of patients in whom LTTE was performed as part of the resuscitation effort and those in whom it was not performed were conducted. RESULTS: From January 2012 to January 2013, 37 patients did not survive traumatic cardiac arrest while in the trauma bay: 14 in the LTTE group and 23 in the non-LTTE group. When comparing the LTTE and non-LTTE groups, both were similar in sex distribution (LTTE, 86% male; non-LTTE, 74% male; P = .68), age (34.8 versus 24.1 years; P= .55), Injury Severity Score (41.0 versus 38.2; P= .48), and percentage of penetrating trauma (21.6% versus 21.7%; P = .29). Compared with the non-LTTE group, the LTTE group spent significantly less time in the trauma bay (13.7 versus 37.9 minutes; P = .01), received fewer blood products (7.1% versus 31.2%; P = .789), and were less likely to undergo nontherapeutic thoracotomy in the emergency department (7.14% versus 39.1%; P < .05). The non-LTTE group had a mean of $3040.50 in hospital costs, compared with the mean for the LTTE group of $1871.60 (P = .0054). CONCLUSIONS: In this study, image-guided resuscitation with LTTE decreased the time in the trauma bay and avoided nontherapeutic thoracotomy in nonsurviving trauma patients. Limited TTE could improve the use of health care resources in patients with traumatic cardiac arrest.

Pyogenic flexor tenosynovitis: assessment and management in the emergency department setting.

Emergency departments are frequently confronted with had infections. Significant morbidity can result from hand infections when they are not appropriately diagnosed or treated. Clinical recognition, proper initial evaluation, and treatment are key to prevent functional deficit or devastated morbidity when confronted with hand infections. Pyogenic flexor tenosynovitis is an orthopedic emergency where health care outcomes depend on timely management, prompt recognition, and appropriate treatment. A case report is presented of a patient with worsening pain of a digit after a penetrating injury. The diagnosis was made on the basis of clinical findings and plain radiography.

Cost-utility analysis of prehospital spine immobilization recommendations for penetrating trauma.

BACKGROUND: The American College of Surgeons' Committee on Trauma's recent prehospital trauma life support recommendations against prehospital spine immobilization (PHSI) after penetrating trauma are based on a low incidence of unstable spine injuries after penetrating injuries. However, given the chronic and costly nature of devastating spine injuries, the cost-utility of PHSI is unclear. Our hypothesis was that the cost-utility of PHSI in penetrating trauma precludes routine use of this prevention strategy. METHODS: A Markov model based cost-utility analysis was performed from a society perspective of a hypothetical cohort of 20-year-old males presenting with penetrating trauma and transported to a US hospital. The analysis compared PHSI with observation alone. The probabilities of spine injuries, costs (US 2010 dollars), and utility of the two groups were derived from published studies and public data. Incremental effectiveness was measured in quality-adjusted life-years. Subset analyses of isolated head and neck injuries as well as sensitivity analyses were performed to assess the strength of the recommendations. RESULTS: Only 0.2% of penetrating trauma produced unstable spine injury, and only 7.4% of the patients with unstable spine injury who underwent spine stabilization had neurologic improvement. The total lifetime per-patient cost was $930,446 for the PHSI group versus $929,883 for the nonimmobilization group, with no difference in overall quality-adjusted life-years. Subset analysis demonstrated that PHSI for patients with isolated head or neck injuries provided equivocal benefit over nonimmobilization. CONCLUSION: PHSI was not cost-effective for patients with torso or extremity penetrating trauma. Despite increased incidence of unstable spine injures produced by penetrating head or neck injuries, the cost-benefit of PHSI in these patients is equivocal, and further studies may be needed before omitting PHSI in patients with penetrating head and neck injuries. LEVEL OF EVIDENCE: Economic and value-based evaluation, level II.

[Assessment of liberal physician's occupational risks management on the exposure to biological fluids]. / Évaluation des pratiques des médecins libéraux sur la gestion des risques professionnels liés à l'exposition aux liquides biologiques.

INTRODUCTION: During their practice, liberal physicians might have a risk of viral exposure to biological fluids. That risk is well-known in hospitals. The purpose of this study was to measure those occupational risks into their own private practice. METHODS: This observational descriptive transversal multicentral, epidemiological study is based on the information collected from 400 physicians (general practitioners, ENT specialists, dermatologists, pediatricians, rheumatologists and gynecologists), working in own private practice in Lorraine. They received by post a confidential survey consisting of multiple-choice and open questions, asking for their activity, their risks of being exposed to biological fluids, their vaccine coverage and their potentially infectious medical waste (PIMW) management. RESULTS: Among 175 physicians who replied to the survey, 153 did invasive procedures and 58 encountered an accidental blood exposure (ABE). The execution of invasive procedures was the main factor in having an ABE (P=0.0023). Around 89.5 % of the complications were due to percutaneous injuries. Still 30.9 % of the physicians always recapped needles and 40 % hadn't a complementary health cover. More than 82 % were up-to-date on mandatory vaccinations (hepatitis B and diphtheria-tetanus-poliomyelitis). In private practice, 97.6 % of physicians sort out blunt objects (prickly or sharp), which is quite satisfactory in comparison with only 60.5 % of them who sort out soft wastes and 44.6 % of blunt objects at patient's home. CONCLUSION: Even if physician's blunt objects disposal in private practice and their mandatory vaccination are satisfactory, "standard" precautions, safety equipment use and soft wastes disposal can be improved.

Massive posttraumatic bleeding: epidemiology, causes, clinical features, and therapeutic management.

Bleeding typically results as a consequence of derangements of primary hemostasis, secondary hemostasis, or both, and can be dramatically amplified by the presence of other predisposing conditions, especially inherited bleeding disorders. Life-threatening hemorrhages are, however, almost exclusively caused by penetrating wounds, blunt traumas of chest and abdomen, suicide attempts, amputations, bone fractures with concomitant injury to internal organs and blood vessels, and shearing forces from sudden rotation, violent flexion, extension, or deceleration injuries. The pathogenesis of posttraumatic bleeding is complex and multifaceted. The most dramatic phenomenon that always accompanies major hemorrhages is the abrupt and considerable loss of intravascular volume, that further leads to hypovolemic shock, also known as hemorrhagic shock, culminating with peripheral ischemia, especially in those tissues where oxygen delivery is more critical (i.e., central nervous system and myocardium). The mortality rate of severe posttraumatic bleeding can be as high as 50%, especially when an appropriate treatment is not established in a timely manner. The damage control sequence basically entails a four-step approach including damage control surgery, damage control resuscitation with fluid restoration, and hemocomponents administration, as well as correction of the coagulopathy with platelets, antifibrinolytic (e.g., tranexamic acid), and/or procoagulant agents such as fresh frozen plasma, prothrombin complex concentrate, or recombinant-activated Factor VII.

Does payer status matter in predicting penetrating trauma outcomes?

BACKGROUND: Few data exist regarding payer status as a predictor of outcomes in penetrating trauma. This study determined whether insurance status impacts in-hospital complications and mortality in gunshot and stab wound patients at our inner-city, level I trauma center. METHODS: Penetrating trauma admissions from 2005 to 2009 were reviewed for patient demographics, insurance, Injury Severity Score, complications, duration of stay, and mortality. RESULTS: A total of 1,347 penetrating trauma patients were admitted with 652 (48.4%) uninsured. Although uninsured patients were more likely to be male (93.3% vs 89.8%, P = .030), there was no difference in age, ISS, or number of radiologic, operative, or interventional procedures. Uninsured patients had lesser intensive care unit (4.4 vs 3.3 days; P = .049) and total hospital length of stay (10.2 vs 8.3; P = .049). No uninsured patients were placed into a rehabilitation facility at the time of discharge (0.0% vs 1.6%, P < .001). There was no difference in frequency of pulmonary complications, thromboembolic complications, sepsis, urinary tract infection, or wound infections. On multivariate analysis, being uninsured was not an independent predictor of in-hospital complications (1.010, 95% confidence interval 0.703-1.450, P = .959) or mortality (odds ratio 0.905, 95% confidence interval 0.523-1.566, P = .722). CONCLUSION: This is the first study to show that penetrating trauma patients who are uninsured have lesser duration of stay and decreased placement into a rehabilitation facility. Being uninsured added no additional risk of in-hospital complications or mortality.

Follow-up after asymptomatic penetrating thoracic injury: 3 hours is enough.

BACKGROUND: Patients with asymptomatic penetrating thoracic injuries routinely undergo chest radiographs (CXRs) upon emergency department (ED) arrival, and then 6 hours later to exclude delayed pneumothorax (PTX) or hemothorax (HTX). Although previous reports indicate that up to 12% (mean, 3%) of asymptomatic penetrating thoracic injuries are complicated by delayed PTX or HTX, we hypothesized that these events would be detectable after only 3 hours of observation. The purpose of this study was to compare the incidence of delayed thoracic injury at 3 hours and 6 hours using standard CXR. METHODS: A prospective trial of asymptomatic patients with penetrating thoracic injuries was conducted during 36 months. CXRs were performed upon arrival (supine, AP), and at 3 hours (upright, PA/lateral) and 6 hours (upright, PA/lateral). Patients with either injuries detected on initial CXR or cardiopulmonary symptoms were excluded. Findings from 3 hour and 6 hour CXRs were compared. Assuming a delayed PTX or HTX rate of 3%, the probability of detecting at least one delayed event between 3 hours and 6 hours in 100 patients is 95.25%. RESULTS: Of 648 patients with penetrating thoracic injuries, 100 patients both met inclusion criteria and completed the study. Patients were predominantly young (32.5 years +/- 13.3 years [mean +/- SD]) men (75% men) with stab wounds (75% stab wounds, 25% gunshot wounds). The mean length of stay for patients discharged from the ED was 8.8 hours +/- 2.6 hours. Although two patients developed a PTX between arrival and 3 hours, none developed after 3 hours. Patient charges, hospital costs, and radiation exposure were calculated for patients in our proposed study protocol, totaling $2802, $189, and 0.08 mSv, respectively. CONCLUSIONS: No patient in our study population developed a delayed PTX or HTX after 3 hours. Our results suggest that shortening the observation period after asymptomatic penetrating thoracic injuries to 3 hours is safe, cost-effective, minimizes radiation exposure, and may help relieve congested urban EDs.

[Medico-legal assessment of blood accumulation in human abdominal cavity caused by penetrating wounds].

When primary injuries caused by penetrating violence and secondary injuries by faulty medical procedures are both present, it is important to distinguish "avoidable" from "unavoidable" secondary injuries. The primary and "unavoidable" secondary injuries rather than the secondary "avoidable" injuries should be included as evidence for assessment of the degree and grade the injuries. The basic principles to assess blood accumulation after injury have been stated in the seventy-two clause of "The Assessment Criterion of Severe Human Body Injury". However, it dose not distinguish abdominal blood accumulation caused by primary penetrating wounds from that resulted from secondary medical procedures. An amendment to the clause might be necessary.

Excess mortality, length of stay, and costs associated with serious hemorrhage among trauma patients: findings from the National Trauma Data Bank.

Trauma is a serious injury or shock to the body from violence or crash and is an important and growing global health risk. Using 2000 to 2004 data from a comprehensive trauma registry, we estimated the prevalence of serious blunt and penetrating trauma-related hemorrhage among patients admitted to U.S. trauma centers along with excess in-hospital mortality, length of hospital stay, and inpatient costs. There were 65,750 patients with blunt trauma and 12,992 patients with penetrating trauma included in our analyses. Of patients sustaining blunt trauma, 7.6 per cent had serious hemorrhage; 18.8 per cent of patients sustaining penetrating trauma had serious hemorrhage. In-hospital mortality rates were significantly (P < 0.05) higher for patients with serious hemorrhage than for patients without (24.9 per cent versus 8.4 per cent for blunt; 23.4 per cent versus 4.2 per cent for penetrating). Patients with serious hemorrhage had adjusted mean excess lengths of stay of 0.4 days for blunt trauma and 2.7 days for penetrating trauma (P < 0.05); adjusted excess costs were $296 per day for patients sustaining blunt trauma and $637 per day for patients sustaining penetrating trauma (P < 0.05). In both blunt and penetrating trauma cases, serious hemorrhage is significantly associated with excess mortality, longer hospital stays, and higher costs.

A prospective study of post-traumatic biliary and pancreatic fistuli. The role of expectant management.

BACKGROUND: Biliary or pancreatic fistulae occur frequently after operative repair of liver or pancreatic injuries. The existing literature is based on a few retrospective series. The objective of this prospective study is to evaluate the clinical course and efficacy of non-operative treatment of biliary fistuli (BF) and pancreatic fistuli (PF) post-traumatic fistulae. STUDY DESIGN: Patients who following a trauma Laparotomy, developed BF or PF were prospectively followed during a 38-month period (June 1999-August 2001). Demographics, injury type and severity, fistula characteristics and daily output, complications, interventions and cost were recorded. Optimal nutrition, wound management, and control of infection were priorities in fistula management. A fistula was considered completely healed if the patient was on regular diet and the output was zero for at least 48 h. RESULTS: Of 160 patients (injury severity score: 21 + 10) with trauma laparotomy for a liver or pancreatic injury, nineteen patients (12%) developed a fistula (11 BF, 8 PF). No patient died. Infections occurred in 45% (5/11) of BF patients and 50% (4/8) of PF patients. Only two patients required an operation, one for biliopericardium and one more for a pancreatic pseudo-cyst. Fistula management was responsible for more than half of the hospital stay and cost. Patients with PF had longer hospital stays (44 + 28 days) and charges (US dollars 345,000 + 218,000) than patients with BF (22 + 12 days and US dollars 103,000 + 61,000, respectively). CONCLUSIONS: Most post-traumatic BF and PF can be managed non-operatively. BF resolves earlier than PF. Both entities are responsible for substantial increases in hospital length of stay and charges.

FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma.

OBJECTIVE: To evaluate the FAST (focused assessment with sonography in trauma) examination for determining traumatic pericardial effusion and intraperitoneal fluid indicative of injury in patients with penetrating anterior chest trauma. METHODS: An observational prospective study was conducted over a 30-month period at an urban level I trauma center. FAST was performed in the emergency department by emergency physicians and trauma surgeons. FAST results were recorded before review of patient outcome as determined by 1 or more of the following: thoracotomy, laparotomy, pericardial window, cardiologic echocardiography, diagnostic peritoneal lavage, computed tomography, and serial examinations. RESULTS: FAST was undertaken in 32 patients with penetrating anterior chest trauma: 20 (65%) had stab wounds, and 12 (35%) had gunshot wounds. Sensitivity of FAST for cardiac injury (n = 8) in patients with pericardial effusion was 100% (95% confidence interval, 63.1%-100%); specificity was 100% (95% confidence interval, 85.8%-100%). The presence of pericardial effusion determined by FAST correlated with the need for thoracotomy in 7 (87.5%) of 8 patients (95% confidence interval, 47.3%-99.7%). One patient with a pericardial blood clot on cardiologic echocardiography was treated nonsurgically. FAST had 100% sensitivity for intraperitoneal injury (95% confidence interval, 63.1%-100%) in 8 patients with views indicating intraperitoneal fluid but without pericardial effusion, again with no false-positive results, giving a specificity of 100% (95% confidence interval, 85.8%-100%). This prompted necessary laparotomy in all 8. CONCLUSIONS: In this series of patients with penetrating anterior chest trauma, the FAST examination was sensitive and specific in the determination of both traumatic pericardial effusion and intraperitoneal fluid indicative of injury, thus effectively guiding emergent surgical decision making.

Prediction of traumatic wound infection with a neural network-derived decision model.

The objective of this study was to develop and validate a decision model, using an artificial neural network, that predicts infection in uncomplicated, traumatic, sutured wounds. The study was a prospective, cohort study of all patients presenting to the emergency department of a county teaching hospital with uncomplicated wounds that required suturing. In evaluating and treating wounds, emergency medicine (EM) faculty and residents, resident physicians in primary-care specialties, and supervised medical students on EM clerkships followed a standardized wound-management protocol. Clinicians estimated the likelihood of subsequent infection using a 5-point scale. Wound healing was followed until sutures were removed. Wound outcome data were collected by medical personnel blinded to the initial prediction. Student's t-tests and Pearson's chi-square statistic were used to identify independent predictors that served as input variables. Wound infection was the single output variable. Neural network analysis was used to assign weights to input variables and derive a decision equation. A total of 1,142 wounds were analyzed in the study. The overall infection rate was 7.2%. The most predictive factors for wound infection were wound location, wound age, depth, configuration, contamination, and patient age. To derive a decision equation for the model, the network was trained on data from half of the subjects and tested on the remainder. When used as a diagnostic test for wound infection, the decision model had a sensitivity of 70%, as compared to 54% for physicians, and a specificity of 76%, as compared to 78% for physicians. We conclude that through the use of combinations of 7 clinical variables available at the time of initial wound management, a neural network-derived decision model may be used to identify uncomplicated, traumatic wounds at higher risk for infection.

Assessment of specific mRNA levels in cartilage regions in a lapine model of osteoarthritis.

Osteoarthritis (OA) is the most common form of arthritis and patients with meniscal and ligament injuries of the knee are at high risk to develop the disease. The purpose of this study was to evaluate molecular and structural changes occurring in four articular cartilage (AC) regions from the knees of anterior cruciate ligament (ACL)-transected rabbits at 3 and 8 weeks post-surgery. Rabbit AC from the lateral and medial femoral condyles (LFC and MFC) as well as from the medial and lateral tibial plateau (MTP and LTP) were processed for histology and for semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for a subset of relevant molecules (collagen II, aggrecan. biglycan, decorin, fibromodulin, MMP-1, -3, -13, and TIMP-1). While the most severe histological changes were observed in the MTP starting as early as 3 weeks post-ACL transection based on Mankin scores, histological examination demonstrated a progression of osteoarthritic changes in the MFC from 3 to 8 weeks post-surgery. In contrast, very few changes were observed within both the LFC and LTP, and these changes did not worsen with increasing time after surgery. The water content increased significantly in the MFC at 8 weeks post-ACL transection and at both 3 and 8 weeks post-ACL transection in the MTP. Significant decreases in DNA content were observed for the MFC, LTP and MTP at 8 weeks post-ACL transection. Total RNA yields from the MFC and MTP were significantly elevated at 8 weeks post-ACL transection, while in the lateral compartment total RNA was unchanged following ACL transection. Analysis of mRNA levels for a subset of matrix molecules, proteinases and proteinase inhibitors, by RT-PCR demonstrated significant region-specific changes at the mRNA level following ACL transection. These results show that following ACL transection, complex molecular, as well as structural changes occur early in cartilage and that the observed changes are both region-specific and time-dependent.