Chronic Pain, Hopelessness, and Suicide Risk Among Adult Medical Inpatients

BACKGROUND

Medically ill adults are at elevated risk for suicide. Chronic pain and hopelessness are associated with suicide; however, few studies have examined the interaction between chronic pain and hopelessness in predicting suicide risk among hospitalized adults.

OBJECTIVE

This study aimed to describe the association between chronic pain, hopelessness, and suicide risk, defined as recent suicidal ideation or lifetime suicidal behavior. In addition, we examined the interaction between chronic pain and hopelessness.

METHODS

This was a secondary analysis of a multisite study to validate the Ask Suicide-Screening Questions (ASQ) among adult medical inpatients. Participants reported if they experienced chronic pain that impacted daily life and if they felt hopeless about their medical condition and provided their current pain rating on a 1 to 10 scale, with 10 being the most severe pain. A t-test compared pain severity scores by ASQ outcome. A binary logistic regression model described the association between chronic pain, hopelessness, and suicide risk; parameter estimates are expressed as odds ratios (OR) for interpretation. The interaction between chronic pain and hopelessness was examined in both the transformed (logit) and natural (probability) scales of the generalized linear model.

RESULTS

The sample included 720 participants (53.2% male, 62.4% White, mean age: 50.1 [16.3] years, range = 18-93). On the ASQ, 15.7% (113/720) of patients screened positive. Half (360/720) of the sample self-reported chronic pain. Individuals who screened positive had higher pain rating scores than those who screened negative (t = -4.2, df = 147.6, P < 0.001). Among all patients, 27.2% (196/720) felt hopeless about their medical condition. In the logistic regression model, patients with chronic pain (adjusted OR: 2.29, 95% confidence interval [CI]: 1.21-4.43, P = 0.01) or hopelessness (adjusted OR: 5.69, 95% CI: 2.52-12.64, P < 0.001) had greater odds of screening positive on the ASQ. The interaction effect between pain and hopelessness was not significant in the transformed (B = -0.15, 95% CI: -1.11 to 0.82, P = 0.76) or natural (B = 0.08, 95% CI: -0.07 to 0.23, P = 0.28) scale.

CONCLUSIONS

There were significant independent associations between (1) chronic pain and suicide risk and between (2) hopelessness and suicide risk. Future research should examine the temporality and mechanisms underlying these relationships to inform prevention efforts for medically ill adults.

Utility of Thermal Imaging in Predicting Superficial Infections in Transfemoral Osseointegrated Implants

Background

Superficial infection is a common minor complication of transcutaneous implants that can be challenging to predict or diagnose. Although it remains unclear whether superficial infections progress to deep infections (which may require implant removal), predicting and treating any infection in these patients is important. Given that flap thinning during stage II surgery requires compromising vascularity for stability of the skin penetration aperture, we hypothesized that early skin temperature changes predict long-term superficial infection risk.

Methods

We obtained standardized thermal imaging and recorded surface temperatures of the aperture and overlying flaps 2 weeks postoperatively for the first 34 patients (46 limbs) treated with the Osseointegrated Prosthesis for the Rehabilitation of Amputees transfemoral implant system. We used two-sided t tests to compare temperatures surrounding the aperture and adjacent soft tissues in patients with and without subsequent infection.

Results

During median follow-up of 3 years, 14 limbs (30.4%) developed 23 superficial infections. At patients' initial 2-week visit, mean skin temperature surrounding the aperture was 36.3ºC in limbs that later developed superficial infections and 36.7ºC in uninfected limbs (P = 0.35). In four patients with bilateral implants who later developed superficial infection in one limb, average temperature was 1.5ºC colder in the infected limb (P = 0.12).

Conclusions

Superficial infections remain a frequent complication of transfemoral osseointegration surgery. We did not find differences in early heat signatures between limbs subsequently complicated and those not complicated by superficial infection. Further research should explore more objective measures to predict, diagnose, and prevent infections after osseointegration surgery.

Healthcare Utilization Following Hemipelvectomy or Hip Disarticulation in the Military Health System

INTRODUCTION

Amputations at the hip and pelvic level are often performed secondary to high-energy trauma or pelvic neoplasms and are frequently associated with a prolonged postoperative rehabilitation course that involves a multitude of health care providers. The purpose of this study was to examine the health care utilization of patients with hip- and pelvic-level amputations that received care in the U.S. Military Health System.

MATERIALS AND METHODS

We performed a retrospective review of all patients who underwent a hip- or pelvic-level amputation in the Military Health System between 2001 and 2017. We compiled and reviewed all inpatient and outpatient encounters during three time points: (1) 3 months pre-amputation to 1 day pre-amputation, (2) the day of amputation through 12 months post-amputation, and (3) 13-24 months post-amputation. Health care utilization was defined as the average number of encounter days/admissions for each patient. Concomitant diagnoses following amputation including post-traumatic stress disorder, traumatic brain injury, anxiety, depression, and chronic pain were also recorded.

RESULTS

A total of 106 individuals with hip- and pelvic-level amputations were analyzed (69 unilateral hip disarticulation, 6 bilateral hip disarticulations, 27 unilateral hemipelvectomy, 2 bilateral hemipelvectomies, and 2 patients with a hemipelvectomy and contralateral hip disarticulation). Combat trauma contributed to 61.3% (n = 65) of all amputations. During the time period of 3 months pre-amputation, patients had an average of 3.8 encounter days. Following amputation, health care utilization increased in both the year following amputation and the time period of 13-24 months post-amputation, averaging 170.8 and 77.4 encounter days, respectively. Patients with trauma-related amputations averaged more total encounter days compared to patients with disease-related amputations in the time period of 12 months following amputation (203.8 vs.106.7, P < .001) and the time period of 13-24 months post-amputation (92.0 vs. 49.0, P = .005). PTSD (P = .02) and traumatic brain injuries (P < .001) were more common following combat-related amputations.

CONCLUSIONS

This study highlights the increased health care resource demand following hip- and pelvic-level amputations in a military population, particularly for those patients who sustained combat-related trauma. Additionally, patients with combat-related amputations had significantly higher rates of concomitant PTSD and traumatic brain injury. Understanding the extensive needs of this unique patient population helps inform providers and policymakers on the requirements for providing high-quality care to combat casualties.

The Scope and Distribution of Upper Extremity Nerve Injuries Associated With Combat-Related Extremity Limb Salvage

PURPOSE

Chronic pain and functional limitations secondary to nerve injuries are a major barrier to optimal recovery for patients following high-energy extremity trauma. Given the associated skeletal and soft tissue management challenges in the polytraumatized patient, concomitant nerve injuries may be overlooked or managed in delayed fashion. Whereas previous literature has reported rates of peripheral nerve injuries at <10% in the setting of high-energy extremity trauma, in our experience, the incidence of these injuries has been much higher. Thus, we sought to define the incidence, pain sequelae, and functional outcomes following upper extremity peripheral nerve injuries in the combat-related limb salvage population.

METHODS

We performed a retrospective review of all patients who underwent limb salvage procedures to include flap coverage for combat-related upper extremity trauma at a single institution between January 2011 and January 2020. We collected data on patient demographics; perioperative complications; location of nerve injuries; surgical interventions; chronic pain; and subjective, patient-reported functional limitations.

RESULTS

A total of 45 patients underwent flap procedures on 49 upper extremities following combat-related trauma. All patients were male with a median age of 27 years, and 96% (n = 47) of injuries were sustained from a blast mechanism. Thirty-three of the 49 extremities (67%) sustained associated nerve injuries. The most commonly injured nerve was the ulnar (51%), followed by median (30%) and radial/posterior interosseous (19%). Of the 33 extremities with nerve injuries, 18 (55%) underwent surgical intervention. Nerve repair/reconstruction was the most common procedure (67%), followed by targeted muscle reinnervation (TMR, 17%). Chronic pain and functional limitation were common following nerve injury.

CONCLUSIONS

Upper extremity peripheral nerve injury is common following high-energy combat-related trauma with high rates of chronic pain and functional limitations. Surgeons performing limb salvage procedures to include flap coverage should anticipate associated peripheral nerve injuries and be prepared to repair or reconstruct the injured nerves, when feasible.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Thighplasty at the Time of Stage-1 Bone-Anchored Osseointegration Surgery

Background

For patients with transfemoral amputations and difficulty tolerating conventional socket-based prostheses, osseointegrated (OI) implants have enabled increased prosthetic use, improved patient satisfaction, and shown promising functional outcomes1,2. Although the use of OI implants effectively eliminates the soft-tissue-related challenges that have plagued socket-based prostheses, the presence of a permanent, percutaneous implant imparts a host of new soft-tissue challenges that have yet to be fully defined. In patients undergoing OI surgery who have redundant soft tissue, we perform a thighplasty to globally reduce excess skin and fat, tighten the soft-tissue envelope, and improve the contour of the residual limb.

Description

First, the orthopaedic surgical team prepares the residual femur for implantation of the OI device. After the implant is inserted, the residual hamstrings and quadriceps musculature are closed over the end of the femur, and the subcutaneous tissue and skin are closed in a layered fashion. Although the anatomic location and amount of excess soft tissue are patient-dependent, we perform a standard pinch test to determine the amount of soft tissue that can be safely removed for the thighplasty. Once the proposed area of resection is marked, we proceed with longitudinal, sharp dissection down to the level of the muscular fascia. At this point, we use another pinch test to confirm the amount of soft-tissue resection that will allow for adequate resection without undue tension3. Excess subcutaneous fat and skin are carefully removed along the previously marked incisions, typically overlying the medial compartment of the thigh in the setting of patients with transfemoral amputations. The thighplasty incision is closed in a layered fashion over 1 or 2 Jackson-Pratt drains, depending on the amount of resection.

Alternatives

Depending on the amount of redundant soft tissue, thighplasty may not be necessary at the time of OI surgery; however, in our experience, excess soft tissue surrounding the transcutaneous aperture can predispose the patient to increased shear forces at the aperture, increased drainage, and increased risk of infection4.

Rationale

Although superficial infectious complications are most common following OI surgery, the need for soft-tissue refashioning and excision is one of the most common reasons for reoperation1,5. Our group has been more aggressive than most in our use of a vertical thighplasty procedure to globally reduce soft-tissue motion in the residual limb to avoid reoperation.

Expected Outcomes

Although much of the OI literature has focused on infectious complications, recent studies have demonstrated reoperation rates of 18% to 36% for redundant soft tissue following OI surgery1,5. We believe that thighplasty at the time of OI not only reduces the likelihood of reoperation but may also decrease infectious complications by reducing relative motion and inflammation at the skin-implant interface4,6.

Important Tips

The thighplasty procedure is ideally performed as part of the first stage of the OPRA (Osseointegrated Prosthesis for the Rehabilitation of Amputees) procedure to limit the likelihood of problematic ischemia-related complications.We utilize a confirmatory pinch test both before and throughout the thighplasty procedure to ensure adequate resection without undue tension.The thighplasty excision pattern utilizes a long vertical limb designed to decrease the circumferential laxity of the residual limb. Maximal tension is borne on the vertical limb and not on the transverse extensions, as these are prone to scar widening and distortion of surrounding tissues.Closed-suction drainage is utilized liberally to decrease the likelihood of a symptomatic seroma.

Acronyms and Abbreviations

OI = osseointegratedOPRA = Osseointegrated Prosthesis for the Rehabilitation of AmputeesPVNS = pigmented villonodular synovitisT-GCT = tenosynovial giant-cell tumor.BMI = body mass indexPMH = past medical history.

Heterotopic Ossification Formation in Military Beneficiaries Following Hip- and Pelvic-Level Amputations

INTRODUCTION

Traumatic hip and pelvic level amputations are uncommon but devastating injuries and associated with numerous complications that can significantly affect quality of life for these patients. While heterotopic ossification (HO) formation has been reported at rates of up to 90% following traumatic, combat-related amputations, previous studies included few patients with more proximal hip and pelvic level amputations.

MATERIALS AND METHODS

We conducted a retrospective review of the Military Health System medical record and identified patients with both traumatic and disease-related hip- and pelvic-level amputations performed between 2001 and 2017. We reviewed the most recent pelvis radiograph at least 3 months following amputation to determine bony resection level and the association between HO formation and reason for amputation (trauma versus disease related).

RESULTS

Of 93 patients with post-amputation pelvis radiographs available, 66% (n = 61) had hip-level amputations and 34% (n = 32) had a hemipelvectomy. The median duration from the initial injury or surgery to the most recent radiograph was 393 days (interquartile range, 73-1,094). HO occurred in 75% of patients. Amputation secondary to trauma was a significant predictor of HO formation (χ2 = 24.58; P < .0001); however, there was no apparent relationship between the severity of HO and traumatic versus non-traumatic etiology (χ2 = 2.92; P = .09).

CONCLUSIONS

Amputations at the hip were more common than pelvic-level amputations in this study population, and three-fourths of hip- and pelvic-level amputation patients had radiographic evidence of HO. The rate of HO formation following blast injuries and other trauma was significantly higher compared with patients with non-traumatic amputations.

A Quantitative and Qualitative Literature Analysis of the Orthopedic Surgeons' Experience: Reflecting on 20 Years in the Global War on Terror

INTRODUCTION

After over 20 years of war in the Middle East, orthopedic injuries have been among the most prevalent combat-related injuries, accounting for 14% of all surgical procedures at Role 2/3 (R2/R3) facilities according to the DoD Trauma Registry. To further delineate the role of the deployed orthopedic surgeon on the modern battlefield, a retrospective review was performed highlighting both quantitative and qualitative analysis factors associated with orthopedic surgical care during the war in the Middle East.

METHODS

A retrospective review was conducted of orthopedic surgeons in the Middle East from 2001 to 2021. A comprehensive literature search was conducted using the PubMed and Embase databases using a two-reviewer strategy. Articles were compiled and reviewed using Covidence. Inclusion criteria included journal articles focusing on orthopedic injuries sustained during the Global War on Terror (GWoT) in an adult U.S. Military population. In the event of a conflict, a third author would determine the relevance of the article. For the remaining articles, a full-text review was conducted to extract relevant predetermined quantitative data, and the Delphi consensus method was then utilized to highlight relevant qualitative themes.

RESULTS

The initial search yielded 1,226 potentially relevant articles. In all, 40 studies ultimately met the eligibility criteria. With the consultation of previously deployed orthopedic surgeons at the Walter Reed National Military Medical Center, a retrospective thematic analysis of the 40 studies revealed five themes encompassing the orthopedic surgeons experience throughout GWoT. These themes include unique mechanisms of orthopedic injury compared to previous war injuries due to novel weaponry, differences in interventions depending on R2 versus R3 locations, differences in injuries from those seen in civilian settings, the maintained emphasis on humanitarian aspect of an orthopedic surgeon's mission, and lastly relation of pre-deployment training to perceived deployed success of the orthopedic surgeons. From this extensive review, we found that explosive mechanisms of injury were greatly increased when compared to previous conflicts and were the etiology for the majority of orthopedic injuries sustained. With the increase of complex explosive injuries in the setting of improved body armor and overall survival, R2/3 facilities showed an increased demand for orthopedic intervention including debridement, amputations, and external fixation. Combat injuries sustained during the GWoT differ in the complications, management, and complexity when compared to civilian trauma. "Humanitarian" cases made up a significant number of operative cases for the deployed orthopedic surgeon. Lastly, heterogeneous training opportunities were available prior to deployment (fellowship, combat extremity surgical courses, and dedicated pre-deployment training), and the most commonly identified useful training was learning additional soft-tissue coverage techniques.

CONCLUSION

These major themes indicate an emphasis on pre-deployment training and the strategic positioning of orthopedic surgeons to reflect the changing landscape of musculoskeletal trauma care. Moving forward, these authors recommend analyzing the comfort and perceived capability of orthopedic surgeons in these unique military environments to best prepare for a changing operational format and the possibility of future peer-peer conflicts that will likely lead to a lack of medical evacuation and prolonged field care.

Mini-Open Achilles Tendon Repair: Improving Outcomes While Decreasing Complications

An acute rupture of the Achilles tendon is a traumatic injury that can cause considerable morbidity and reduced function. Nonoperative intervention may put patients at higher risk of rerupture, whereas surgical intervention carries risk of infection, wound complications, and iatrogenic nerve injury. The mini-open Achilles tendon repair technique has been popularized in helping decrease complications. The goal of this study was to examine and compare the functional outcomes and rate of complications in patients treated with a mini-open repair technique versus a traditional open repair for acute Achilles tendon ruptures. A retrospective review was performed of all patients with a complete Achilles tendon rupture that were treated by a single foot and ankle fellowship-trained surgeon. Functional outcome scores were assessed using the American Orthopaedic Foot and Ankle scoring system (AOFAS) and the Achilles Tendon Rupture Score (ATRS). Eighty-one patients with a complete Achilles tendon rupture underwent mini-open repair and 22 patients underwent traditional open repair surgery between 2013 and 2020. The mean follow-up was 38.40 months (range, 12-71). Mean preoperative AOFAS and ATRS improved in the mini-open group from 45.60 and 47.18 respectively, to 90.29 and 87.97 after surgery (p < .05). Mean preoperative AOFAS and ATRS scores for the traditional open repair (n = 22) cohort were 44.02 and 42.27, respectively. Postoperatively, the AOFAS and ATRS scores improved to 85.27 and 86.64 (P value < .05), respectively. There was no statistically significant difference in postoperative ATRS scores. However, the mini-open repair group showed a statistically higher postoperative AOFAS score (90.30) than the traditional open-repair group (85.27) (P value < .05). The overall complication rate for our study was 2.9% (2 mini-open repair and 1 traditional open repair). The complication rate in the mini-open repair group and traditional open repair cohort were 2.4% and 4.5%, respectively (P value > .05). One patient in the mini-open repair cohort (1.2%) reruptured his Achilles tendon 4 months postoperatively. A second patient in the mini-open repair group (1.2%) developed a superficial skin infection and suture irritation. One patient (4.5%) in the traditional open repair group developed a superficial skin infection. There were no sural nerve injuries in our series. The mini-open approach to repair a ruptured Achilles tendon is a viable treatment option to decrease the incidence rate of postoperative complications and rerupture rates while also producing a superior cosmetic result.Level of Evidence: 3 (retrospective cohort study N ≥ 30).

A Longitudinal Perspective on Conversion to Amputation for Combat-Related Extremity Injuries Treated With Flap-Based Limb Salvage

OBJECTIVES

To define the rate and primary drivers behind early and late amputation after flap-based limb salvage in the setting of combat extremity trauma.

DESIGN

Retrospective review.

SETTING

Level II trauma center.

PATIENTS

307 (303 men, 4 women) patients who underwent flap-based limb salvage treatment between 2003 and 2014.

INTERVENTION

We reviewed patient medical records, radiographs, and clinical photographs.

MAIN OUTCOME MEASUREMENTS

Early and late amputation rates, time to amputation, reason for amputation.

RESULTS

307 patients accounted for 323 limbs that underwent flap-based limb salvage treatment (187 lower extremities, 136 upper extremities). A total of 58 extremities (18%) initially treated with flap-based limb salvage ultimately underwent amputation at a median of 480 days (IQR, 285-715 days) from injury. Periarticular fractures and lower extremity injuries were risk factors for early and late amputation. Other independent risk factors for early amputation were flap complications and vascular injuries, whereas risk factors for late amputation were fractures that went on to nonunion.

CONCLUSIONS

This study highlights that a subset of patients ultimately require major limb amputation despite having achieved what is initially considered "successful" limb salvage. Flap-related complications, vascular injury, and lower extremity site of injury were associated with early amputation after successful expeditionary efforts at limb preservation. Conversion to late amputation was associated with lower extremity periarticular fractures and fracture nonunion. Chronic pain and persistent limb dysfunction were the most common reasons for late amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Agonist-Antagonist Myoneural Interface in a Transtibial Amputation

Background

The agonist-antagonist myoneural interface (AMI) technique at the time of transtibial amputation involves the use of agonist-antagonist muscle pairs to restore natural contraction-stretch relationships and to improve proprioceptive feedback when utilizing a prosthetic limb1.

Description

Utilizing the standard incision for a long posterior myofasciocutaneous flap, the lateral and medial aspects of the limb are dissected, identifying and preserving the superficial peroneal and saphenous nerve, respectively. The tendons of the tibialis anterior and peroneus longus are transected distally to allow adequate length for the AMI constructs. After ligation of the anterior tibial vessels, the deep peroneal nerve is identified and tagged to create a regenerative peripheral nerve interface (RPNI). The tibia and fibula are cut approximately 15 cm from the medial joint line, facilitating dissection of the deep posterior compartment and ligation of the peroneal and posterior tibial vessels. The tendons of the lateral gastrocnemius and tibialis posterior are transected distally, and the amputation is completed. The extensor retinaculum is harvested from the residual limb along with multiple 2 × 3-cm free muscle grafts, which will be used for the RPNI constructs. The retinaculum is secured to the tibia with suture anchors, and AMI pairs of the lateral gastrocnemius and tibialis anterior as well as the tibialis posterior and peroneus longus are constructed. Separate RPNIs of the major lower-extremity nerves are performed, and the wound is closed in a standard layered fashion.

Alternatives

An isometric myodesis of the gastrocnemius without coaptation of agonist-antagonist muscle pairs can be performed at the time of transtibial amputation.

Rationale

The AMI technique restores natural agonist-antagonist relationships at the time of transtibial amputation to increase proprioceptive feedback and improve prosthetic control. These outcomes contrast with those of a traditional isometric myodesis, which prevents proprioceptive communication from the residual limb musculature to the central nervous system. Additionally, the AMI technique allows for concentric and eccentric muscular contractions, which may contribute to the maintenance of limb volume and aid with prosthetic fitting, as opposed to the typical limb atrophy observed following standard transtibial amputation1,2. With the development and availability of more advanced prostheses, the AMI technique offers more precise control and increases the functionality of these innovative devices.

Expected Outcomes

Early clinical outcomes of the AMI technique at the time of transtibial amputation have been promising. In a case series of the first 3 patients who underwent the procedure, complications were minor and consisted of 2 episodes of cellulitis and 1 case of delayed wound healing1. Muscle activation measured through electromyography demonstrated an improved ability to limit unintended muscular co-contraction with attempted movement of the phantom limb, as compared with patients who underwent a standard transtibial amputation1. Additionally, residual limb volume was maintained postoperatively without the need for substantial prosthetic modifications.

Important Tips

The tendons of the tibialis anterior, peroneus longus, tibialis posterior, and lateral gastrocnemius should be transected as distal as possible to allow adequate length for creation of the AMI constructs.Approximately 2 × 3-cm free muscle grafts are harvested from the amputated extremity for RPNI3.Smooth tendon-gliding through the synovial tunnels should be confirmed before closure. If necessary, muscle debulking can improve gliding and decrease the size of the residual limb.Harvesting the extensor retinaculum for synovial tunnels has been our preferred method, although we acknowledge that other grafts options such as the tarsal tunnel are available1.

Acronyms & Abbreviations

RPNI = regenerative peripheral nerve interfaceAMI = agonist-antagonist myoneural interfaceEMG = electromyographic.

Unsuccessful Osteochondral Allograft Cap to Prevent Overgrowth in a Pediatric Patient with Previous Transtibial Amputation: A Case Report

CASE

This case demonstrates the attempted utilization of an osteochondral allograft for the prevention of bony overgrowth in a patient with fibular hemimelia and previous transtibial amputation with failure of Teflon capping. Additionally, we describe a novel technique to provide additional padding and increase the width of the residual limb using a dermal allograft.

CONCLUSIONS

Bony overgrowth after pediatric amputations is common and often necessitates revision procedures secondary to infection, ulceration, pain, and discomfort with prosthesis use. Our use of an osteochondral allograft cap to prevent bony overgrowth ultimately failed 13 months following the procedure, and further research on various graft options and other treatment modalities is warranted, especially if the proximal fibula is unavailable or there is concern for donor site morbidity associated with harvesting autologous grafts.

Beyond Limb Salvage: Limb Restoration Efforts Following Remote Combat-Related Extremity Injuries Optimize Outcomes and Support Sustained Surgical Readiness

INTRODUCTION

As the combat operational tempo of the military conflicts in Iraq and Afghanistan has declined over the last decade, there has been a decrease in the number of patients requiring acute limb salvage. In their place, a growing population of patients with persistent functional deficits, pain, and inadequate soft tissue coverage stemming from prior limb salvage strategies have returned to our institution seeking revision surgery. Herein, we examine our institution's evolving surgical approach to extremity reconstruction from 2011 through 2019, culminating in the development of our limb restoration concept. We also discuss the impact of this orthoplastic approach on the acute management of complex extremity trauma and its role in providing sustained surgical readiness during interwar years.

MATERIALS AND METHODS

We retrospectively reviewed all limb reconstructive procedures performed at our tertiary care military treatment facility between September 1, 2011 to December 31, 2019 to characterize the trends in extremity reconstruction procedures performed at our institution. Cases were identified as limb restoration procedures if they involved secondary/revision reconstructive procedures designed to optimize function, treat pain, or improve the durability of the injured extremity following initial reconstruction efforts.

RESULTS

Nearly 500 limb restoration procedures were performed during the study period. These procedures steadily increased since 2011, reaching a maximum of 120 in 2018. Orthoplastic procedures such as osseointegration, targeted muscle reinnervation, regenerative peripheral nerve interface, agonist-antagonist myoneural interface, and soft tissue resurfacing flap reconstruction accounted for the rise in secondary/revision reconstruction performed during this time period.

CONCLUSION

Limb restoration is a collaborative orthoplastic approach that utilizes state-of-the-art surgical techniques for treating complex extremity trauma. Although limb restoration originally developed in response to managing the long-term sequelae of combat extremity trauma, the concept can be adapted to the acute management setting. Moreover, limb restoration provides military surgeons with a means for maintaining critical war-time surgical skills during the current low casualty rate era. Level of Evidence: V, therapeutic.

Running Following Hip Arthroplasty: A Systematic Review

With improved implants and younger patients undergoing total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA), there are increased expectations to return to high-impact activities. Recommendations regarding return to running following hip arthroplasty remain unclear. A search of the PubMed database was conducted, and all publications referencing running following THA or HRA published between January 1, 2000, and September 1, 2020, were included in the systematic review. Patient demographics, surgical variables, activity measures, and revision rates were recorded for each study. A total of 225 unique citations were identified, of which four manuscripts met the eligibility criteria. Eighty-nine of 121 (73.6%) preoperative runners returned to running postoperatively. All four studies reported mean postoperative UCLA activity scores of at least nine. More patients returned to running following HRA than THA with lower rates of revision. Further research with longer postoperative follow-up is necessary to provide definitive recommendations for running following arthroplasty procedures. (Journal of Surgical Orthopaedic Advances 32(1):001-004, 2023).

Institutional Experience and Orthoplastic Collaboration Associated with Improved Flap-based Limb Salvage Outcomes

BACKGROUND

Flap-based limb salvage surgery balances the morbidity and complexity of soft tissue transfer against the potential benefit of preserving a functional limb when faced with a traumatized extremity with composite tissue injury. These composite tissue injuries are well suited for multidisciplinary management between orthopaedic and plastic surgeons. Thus, it makes intuitive sense that a collaborative, orthoplastic approach to flap-based limb salvage surgery can result in improved outcomes with decreased risk of flap failure and other complications, raising the question of whether this orthoplastic team approach should be the new standard of care in limb salvage surgery.

QUESTIONS/PURPOSES

(1) Is there an association between increased annual institutional volume and perioperative complications to include free and local flap failure (substantial flap viability loss necessitating return to the operating room for debridement of a major portion or all of the flap or amputation)? (2) Is an integrated orthoplastic collaborative approach to managing combat-related traumatic injuries of the extremities individually associated with a decreased risk of flap failure and overall flap-related complications? (3) What other factors, such as location of injury, injury severity score, and initial inpatient length of stay, were associated with flap necrosis and flap-related complications?

METHODS

We performed a retrospective review of the electronic medical records of all patients who underwent flap-based limb salvage for combat-related extremity trauma in the United States Military Health System's National Capital Region between January 1, 2003 and December 31, 2012. In total, 307 patients underwent 330 flap procedures. Of the 330 flaps, 59% (195) were local or pedicled flaps and 41% (135) were free flaps. Patients were primarily male (99% [303]), with a median (interquartile range) age of 24 years old (IQR 21 to 29), and 87% (267 of 307) of injuries were sustained from a blast mechanism. We collected data on patient demographics, annual case volume involving flap coverage of extremities, mechanism of injury, flap characteristics, perioperative complications, flap failure, flap revision, isolated orthopaedic management versus an integrated orthoplastic approach, and other salvage procedures. For the purposes of this study, orthoplastic management refers to operative management of flap coverage with microvascular surgeons present for soft tissue transfer after initial debridement and fixation by orthopaedic surgery. The orthoplastic management was implemented on a case-by-case basis based on individual injury characteristics and the surgeon's discretion with no formal starting point. When implemented, the orthoplastic team consisted of an orthopaedic surgeon and microvascular-trained hand surgeons and/or plastic surgeons. In all, 77% (254 of 330) of flaps were performed using this model. We considered perioperative flap complications as any complication (such as infection, hematoma, dehiscence, congestion, or necrosis) resulting in return to the operating room for re-evaluation, correction, or partial debridement of the flap. We defined flap failure as a return to the operating room for debridement of a major portion of the flap or amputation secondary to complete or near-complete loss of flap viability. Of the flap procedures, 12% (40 of 330) were classified as a failure and 14% (46 of 330) experienced complications necessitating return to the operating room. Over the study period, free flaps were not more likely to fail than pedicled flaps (11% versus 13%; p = 0.52) or have complications necessitating additional procedures (14% versus 16%; p = 0.65).

RESULTS

Our multiple linear regression model demonstrated that an increased number of free flaps performed in our institution annually in any given year was associated with a lower likelihood of failure per case (r = -0.17; p = 0.03) and lower likelihood of reoperation for each flap (r = -0.34; p < 0.001), after adjusting for injury severity and team type (orthoplastic or orthopaedic only). We observed a similar relationship for pedicled flaps, with increased annual case volume associated with a decreased risk of flap failure and reoperation per case after adjusting for injury severity and team type (r = -0.21; p = 0.003 and r = -0.22; p < 0.001, respectively). Employment of a collaborative orthoplastic team approach was associated with decreased flap failures (odds ratio 0.4 [95% confidence interval 0.2 to 0.9]; p = 0.02). Factors associated with flap failure included a lower extremity flap (OR 2.7 [95% CI 1.3 to 6.2]; p = 0.01) and use of muscle flaps (OR 2.3 [95% CI 1.1 to 5.3]; p = 0.02).

CONCLUSION

Although prior reports of combat-related extremity trauma have described greater salvage success with the use of pedicled flaps, these reports are biased by institutional inexperience with free tissue transfer, the lack of a coordinated multiservice effort, and severity of injury bias (the most severe injuries often result in free tissue transfer). Our institutional experience, alongside a growing body of literature regarding complex extremity trauma in the civilian setting, suggest a benefit to free tissue coverage to treat complex extremity trauma with adequate practice volume and collaboration. We demonstrated that flap failure and flap-related complications are inversely associated with institutional experience regardless of flap type. Additionally, a collaborative orthoplastic approach was associated with decreased flap failures. However, these results must be interpreted with consideration for potential confounding between the increased case volume coinciding with more frequent collaboration between orthopaedic and plastic surgeons. Given these findings, consideration of an orthoplastic approach at high-volume institutions to address soft tissue coverage in complex extremity trauma may lead to decreased flap failure rates.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Coracoid or Clavicle Fractures Associated With Coracoclavicular Ligament Reconstruction

BACKGROUND

Coracoclavicular (CC) ligament reconstruction is a commonly performed procedure for high-grade acromioclavicular (AC) joint separations. Although distal clavicle and coracoid process fractures represent potential complications, they have been described in only case reports and small case series.

PURPOSE

To identify the incidence and characteristics of clavicle and coracoid fractures after CC ligament reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The US Military Health System Data Repository was queried for patients with a Current Procedural Terminology code for CC ligament repair or reconstruction between October 2013 and March 2020. The electronic health records, including patient characteristics, radiographs, operative reports, and clinical notes, were evaluated for intraoperative or postoperative clavicle or coracoid fractures. Initial operative technique, fracture management, and subsequent clinical outcomes were reviewed for these patients.

RESULTS

A total of 896 primary CC ligament repairs or reconstructions were performed during the study period. There were 21 postoperative fractures and 1 intraoperative fracture in 20 patients. Of these fractures, 12 involved the coracoid and 10 involved the clavicle. The overall incidence of fracture was 3.81 fractures per 1000 person-years. In 5 patients who sustained a fracture, bone tunnels were not drilled in the fractured bone during the index procedure. A total of 17 fractures were ultimately treated operatively, whereas 5 fractures had nonoperative management. Of the 16 active-duty servicemembers who sustained intraoperative or postoperative fractures, 11 were unable to return to full military duty after their fracture care.

CONCLUSION

Fracture of the distal clavicle or coracoid process after CC ligament repair or reconstruction is a rare but serious complication that can occur independent of bone tunnels created during the index procedure. Fractures associated with CC ligament procedures occurred at a rate of 2.46 per 100 cases. Most patients were ultimately treated surgically with open reduction and internal fixation or revision CC ligament reconstruction. Although the majority of patients with intraoperative or postoperative fractures regained full range of motion, complications such as anterior shoulder pain, AC joint asymmetry, and activity-related weakness were common sequelae resulting in physical limitations and separation from military service.

Is There a Need for Recovery Room Radiographs Following Uncomplicated Primary Total Knee Arthroplasty?

Introduction

Total knee arthroplasty (TKA) is one of the most common orthopedic procedures performed in the United States. Obtaining radiographs in the post-anesthesia care unit (PACU) has been the standard of care at most hospitals. The purpose of this study was to examine the utility and cost-effectiveness of immediate, postoperative radiographs in regards to operative decision-making to prevent complications within 90 days after primary TKA.

Methods

A retrospective review of 4,830 consecutive patients who underwent cemented or uncemented TKA between January 2016 and June 2019 at a large, regional medical center was performed. International Classification of Diseases, Tenth Revision (ICD-10) codes were used to track any readmissions within 90 days of TKA. If readmission was for a mechanical complication, including fracture, dislocation, or component loosening, PACU radiographs were reviewed for any abnormalities that may have prevented readmission.

Results

There were 195 readmissions (195 patients), of which 17 were due to mechanical complications. There was no evidence of fracture or abnormality appreciated on any of the reviewed PACU radiographs by either the reading radiologist or the senior authors. Assuming all fractures were noted on immediate, postoperative radiographs, the cost associated with identifying a single fracture in 2,415 patients was $1,072,260.

Conclusion

Routine radiographs in the recovery room after an uncomplicated primary TKA are not a reliable mechanism for preventing mechanical complications and do not alter patient care.

Is There Value in Pathology Specimens in Routine Total Hip and Knee Arthroplasty?

Background Routine analysis of bone specimens in total joint arthroplasty (TJA) is mandatory at many institutions. The purpose of this study was to determine if mandatory routine TJA specimen analysis alters patient care or if they represent an unnecessary healthcare expenditure. Methods A retrospective review was performed of all primary TJA patients between October 2015 and December 2017 at our institution. Pathology results were reviewed to ascertain the number of concordant, discrepant, and discordant results. A diagnosis was considered concordant if the preoperative and pathologic diagnosis matched, discrepant if the preoperative and pathological diagnosis differed but no change in the patient's plan of care occurred, and discordant if the preoperative and pathologic diagnosis differed and resulted in a change in the patient's plan of care.  Results 3,670 total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures (3,613 patients) met the inclusion criteria and were included in this study. All 3,670 specimens had a concordant diagnosis; there were zero discrepant and zero discordant diagnoses. During the study period, our institution spent $67,246.88 in routine analysis of TJA specimens by a pathologist, with no change in any postoperative patient care plans. Conclusion With bundled payment reimbursement models and hospitals trying to decrease unnecessary expenditures, the present study helps further demonstrate that routine analysis has limited cost-effectiveness due to the low prevalence of alteration in the management of patient care. The decision for pathological analysis should be left at the discretion of the surgeon in order to maximize the cost-efficiency of TJA procedures.

Osseointegration of Extremity Prostheses: A Primer for the Plastic Surgeon

Interest in amputation surgery has increased in conjunction with rising public awareness about amputee care. To date, plastic surgeons have impacted the quality of life and functional potential of amputees through novel strategies for sensory feedback and prosthesis control and various techniques for neuroma treatment and prevention. Osseointegration, which involves the direct skeletal attachment of a prosthesis to bone, has the ability to further maximize amputee function. There exists a critical role for plastic surgeons to help optimize techniques for extremity osseointegration through improved wound care and soft-tissue management. An overview of current osseointegrated prostheses and their associated limitations, and potential avenues through which plastic surgeons can help mitigate these challenges, are discussed in this article.

Bilateral Fractures of Anatomic Medullary Locking Hip Arthroplasty Stems in a Single Patient: A Case Report

Introduction:

Stem fracture is a rare complication of total hip arthroplasty (THA) using fully porous-coated femoral stems. Bilateral fractures in a single patient have not been previously reported.

Case Report:

A 48-year-old female underwent bilateral staged primary THA with fully porous-coated anatomic medullary locking femoral prostheses. She subsequently sustained stem fractures of her right and left prostheses in the 13thand 14thyears after their implantation, respectively.

Conclusion:

The bilateral nature of this rare complication in a single patient supports the notion that stem fracture results from a mismatch between the mechanical stresses encountered in vivo and the structural properties of small-diameter stems. Surgeons should be cognizant of this potential complication when evaluating patients at long-term follow-up with new-onset pain.

Definitive External Fixation for Anterior Stabilization of Combat-related Pelvic Ring Injuries, With or Without Sacroiliac Fixation

BACKGROUND

Combat-related pelvic ring injuries frequently lead to placement of a temporizing external fixation device for early resuscitation and transport. These injuries are commonly complicated by concomitant polytrauma and extensive soft-tissue injuries, which may preclude early internal fixation and lead to prolonged use of external fixation. To date, few studies have reported on the outcomes of definitive external fixation for combat-related pelvic ring injuries.

QUESTIONS/PURPOSES

(1) In patients treated with definitive external fixation after combat-related pelvic ring injuries, how often is the quality of reduction within radiographically acceptable parameters at the end of treatment? (2) What proportion of patients demonstrate local heterotopic ossification after these injuries? (3) What patient- and treatment-related factors are associated with increased complications and pain?

METHODS

We retrospectively studied all patients with pelvic ring injuries treated at a tertiary military referral center from January 2003 to December 2012. In total, 114 patients were identified, 55 of whom maintained an external fixation frame throughout their treatment. During that time, the general indications for definitive external fixation were an open, contaminated pelvic ring injury with a high risk of infection or open urologic injury; confluent abdominal, perineal, and thigh wounds; or comminution of the pubic ramus that would necessitate plate fixation extending up the anterior column in patients with open abdomen or exposure-compromising abdominal wounds. Posterior fixation, either sacroiliac or lumbopelvic, was applied in patients with sacroiliac instability. Of the 55 patients with pelvic ring injuries treated with definitive external fixation (27 open and 28 closed), four underwent hemipelvectomy and construct removal for massive ascending infections and four were lost to follow-up, leaving 47 patients (85%) who were available at a minimum follow-up of 12 months (median 29 months, interquartile range 17-43 months). All 47 patients underwent serial imaging to assess their injury and reduction during treatment. External fixators were typically removed after 12 weeks, except in patients in whom pin-site irritation or infection prompted earlier removal, and all were confirmed to be grossly stable during an examination under anesthesia. Clinical union was defined as the absence of radiographically present fracture lines and stable examination findings under anesthesia when the external fixator was removed. Data on demographics, injury pattern, associated injuries, revision procedures, complications, and final functional outcomes including ambulation status, sexual function, and pain were collected. Pelvic radiographs were reviewed for the initial injury pattern, type of pelvic fixation construct, residual displacement after removal of the frame, and evidence of formation of heterotopic ossification in the pelvis or bilateral hips. Pelvic displacement and diastasis were determined by digital caliper measurement on plain images; malunion was defined as anterior diastasis of the pelvis or vertical incongruity of the hemipelvis greater than 10 mm.

RESULTS

Radiographic malunion after construct removal occurred in eight of 24 patients with open injuries and in five of 23 patients with closed injuries. Heterotopic ossification developed in the pelvis or hips of all 24 patients with open injuries and in two of the 23 patients with closed injuries. In patients with open pelvic ring injuries, concomitant acetabular fractures were associated with pelvic pain at the final follow-up examination (risk ratio 1.9; 95% confidence interval, 1.0-3.5; p = 0.017). No treatment factor resulted in superior functional outcomes. In the closed-injury group, concomitant lower-extremity amputation was associated with improved radiographic final reduction (RR 0.4; 95% CI, 0.2-0.7; p = 0.02). There was no association between radiographic malunion and increased pain (RR 1.9; 95% CI, 0.5-7.0; p = 0.54 for the open group; RR 0.8; 95% CI, 0.7-1.0; p = 0.86 for the closed group).

CONCLUSION

In this series of patients with severe combat-related pelvic ring injuries who were treated anteriorly with definitive external fixation because of a severe soft-tissue injury, high infection risk, or unacceptable physiologic cost of internal fixation, malunion and chronic pelvic pain were less common than previously observed. Prior studies primarily differ in their lack of sacroiliac or lumbopelvic stabilization for posteriorly unstable fracture patterns, likely accounting for much of these differences. There may have been important between-study differences such as extremely severe injuries, concomitant injuries, and study population. Our study also differs because we specifically analyzed a large cohort of patients who sustained open pelvic ring injuries. Future studies should prospectively investigate the ideal construct type and pin material, optimize the length of treatment and assessment of healing, and improve radiographic measures to predict long-term functional outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Delirium: treatment and prevention (part 2)

Delirium management begins with non-pharmacologic interventions and treatment of the underlying causes. There are no FDA-approved medications for delirium-related psychosis and agitation, although numerous agents have been studied. Small sample size, narrow inclusion criteria, lack of placebo controls and variable methodologies limit the generalizability of findings to date. Studies and expert guidelines support the use of antipsychotics for delirium-related psychosis and agitation, and demonstrate comparable efficacy and safety between first- and second- generation agents. Mounting evidence also suggests that antipsychotics and dexmedetomidine are effective in preventing delirium in surgical and mechanically- ventilated patients, respectively.

Delirium: presentation, epidemiology, and diagnostic evaluation (part 1)

Delirium is a highly prevalent and complex neuro- psychiatric disorder marked by attentional dysfunction, disturbances in multiple cognitive domains, and changes in motor behavior, perception, sleep, and thought process. Delirium results from diverse toxic, metabolic, infectious, and structural etiologies and is associated with a number of adverse outcomes. Delirium pathophysiology involves perturbation of multiple neurotransmitter systems. Behavioral presentations of delirium are common and are often misattributed to primary psychiatric processes. Diagnostic assessment of delirium includes thorough physical examination, careful cognitive testing, appropriate metabolic and infectious studies, review of medications, and structural brain imaging and electroencephalography as indicated. Pharmacologic and non-pharmacologic interventions have been documented to reduce the incidence and severity of delirium. Anti- psychotics are the treatment of choice for delirium-related agitation and psychosis.

Physician staffing for the practice of psychosomatic medicine in general hospitals: a pilot study

BACKGROUND

The treatment of psychiatric illnesses, prevalent in the general hospital, requires broadly trained providers with expertise at the interface of psychiatry and medicine. Since each hospital operates under different economic constraints, it is difficult to establish an appropriate ratio of such providers to patients.

OBJECTIVE

The authors sought to determine the current staffing patterns and ratios of Psychosomatic Medicine practitioners in general hospitals, to better align manpower with clinical service and educational requirements on consultation-liaison psychiatry services.

METHOD

Program directors of seven academic Psychosomatic Medicine (PM) programs in the Northeast were surveyed to establish current staffing patterns and patient volumes. Survey data were reviewed and analyzed along with data from the literature and The Academy of Psychosomatic Medicine (APM) fellowship directory.

RESULTS

Staffing patterns varied widely, both in terms of the number and disciplines of staff providing care for medical and surgical inpatients. The ratio of initial consultations performed per hospital bed varied from 1.6 to 4.6.

CONCLUSION

Although staffing patterns vary, below a minimum staffing level, there is likely to be significant human and financial cost. Efficient sizing of a PM staff must be accomplished in the context of a given institution's patient population, the experience of providers, the presence/absence and needs of trainees, and the financial constraints of the department and institution. National survey data are needed to provide benchmarks for both academic and nonacademic PM services.

Buprenorphine maintenance therapy hinders acute pain management in trauma

Buprenorphine is a mixed opiate receptor agonist-antagonist growing in popularity as an office-based treatment for opioid-dependent patients. It has high affinity, but only partial agonism at the micro-opioid receptor resulting in a ceiling analgesic effect. At higher doses, buprenorphine potentiates antagonism at the kappa-opioid receptor. These properties make buprenorphine an effective maintenance treatment for opioid-dependent patients. These same properties, however, can interfere with the management of acute pain in patients on maintenance buprenorphine therapy. We present a case of a young multisystem trauma patient in whom adequate analgesia could not be achieved due to buprenorphine treatment before and through the early course of admission. Discontinuation of buprenorphine allowed for appropriate pain management and successful analgesia. Further education of acute care clinicians about buprenorphine pharmacology and careful selection of patients for buprenorphine maintenance therapy are needed to avoid delays of pain control in trauma patients.

Buprenorphine Maintenance Therapy Hinders Acute Pain Management in Trauma

Buprenorphine is a mixed opiate receptor agonist-antagonist growing in popularity as an office-based treatment for opioid-dependent patients. It has high affinity, but only partial agonism at the μ-opioid receptor resulting in a ceiling analgesic effect. At higher doses, buprenorphine potentiates antagonism at the κ-opioid receptor. These properties make buprenorphine an effective maintenance treatment for opioid-dependent patients. These same properties, however, can interfere with the management of acute pain in patients on maintenance buprenorphine therapy. We present a case of a young multisystem trauma patient in whom adequate analgesia could not be achieved due to buprenorphine treatment before and through the early course of admission. Discontinuation of buprenorphine allowed for appropriate pain management and successful analgesia. Further education of acute care clinicians about buprenorphine pharmacology and careful selection of patients for buprenorphine maintenance therapy are needed to avoid delays of pain control in trauma patients.

Münchhausen Syndrome Simulating Acute Aortic Dissection

A young adult man presented to the emergency department reporting a convincing story for acute aortic dissection, a disorder in which diagnostic evaluations should occur in parallel with pharmacologic management. Transesophageal echocardiography demonstrated normal cardiac and aortic structures. Additional history was notable for extensive travel across numerous medical facilities with associated misrepresentation of his diagnosis and treatment. The patient was willing to undergo unpleasant and invasive procedures and succeeded at least once in the past to deceive clinicians to the point of performing a median sternotomy. The intentional presentation of false information leading to unnecessary treatments is consistent with Münchhausen Syndrome.

Preliminary study of the relationship between thyroid status and cognitive and neuropsychiatric functioning in euthyroid patients with Alzheimer dementia

OBJECTIVE

To investigate whether variations within normal ranges of thyroid functioning are related to cognitive and neuropsychiatric functioning in Alzheimer disease (AD).

BACKGROUND

Mild alterations of thyroid hormone levels, even in the normal range, are associated with changes in mood and cognitive functioning in older, nondemented adults, and lower concentrations of thyroid hormones have been shown to be associated with an increased risk for cognitive decline. Less is known about the relationship between thyroid hormone levels and cognitive and neuropsychiatric dysfunction in AD.

METHOD

Twenty-eight euthyroid patients with AD on donepezil underwent evaluation of thyroid status, including measures of thyroid-stimulating hormone (TSH) and free thyroxine (FT4), and cognitive and neuropsychiatric assessment with the Alzheimer's Disease Assessment Scale, Neuropsychiatric Inventory, and Visual Analog Mood Scales.

RESULTS

Correlational analyses indicated statistically significant associations between FT4 concentrations and self-reported feelings of fear and fatigue. Fear and fatigue were negatively correlated with FT4. There were no significant relationships between thyroid hormones and cognition and other depressive and anxiety symptoms.

CONCLUSIONS

Results of this preliminary study support a relationship between thyroid status and neuropsychiatric symptoms in euthyroid individuals with AD, with lower concentrations of FT4 associated with fear and fatigue.

Repetitive self-injurious behavior: a neuropsychiatric perspective and review of pharmacologic treatments

The phenomenology, pathophysiology, and psychopharmacology of repetitive self-injurious behavior (rSIB) are reviewed. Although numerous neurotransmitter systems are thought to be involved in the initiation and maintenance of rSIB, the majority of clinical studies attend to the role of serotonin or endogenous opioids. This focus has emerged from a conceptualization of rSIB as a problem of impulse control (primarily mediated by serotonin) and/or as a maladaptive pain-related behavior (ultimately mediated by opioids). A developmental perspective of rSIB is emphasized, highlighting the biased prevalence of rSIB among patients with mental retardation and severe personality disorders and the significance of critical developmental events leading to pathology in "pedagogical" neural circuits. A novel typology is offered in an effort to better match interventions with rSIB subtypes. Achievement of this ultimate goal however, must await further research.

Differential tolerance is induced in T cells recognizing distinct epitopes of myelin basic protein

Experimental allergic encephalomyelitis (EAE) is induced by T cell-mediated immunity to central nervous system antigens. In H-2u mice, EAE is mediated primarily by T cells specific for residues 1-11 of myelin basic protein (MBP). We demonstrate that differential tolerance to MBP1-11 versus epitopes in MBP121-150 is induced by expression of endogenous MBP, reflecting extreme differences in stability of peptide/MHC complexes. The diverse MBP121-150-specific TCR repertoire can be divided into three fine specificity groups. Two groups were identified in wild-type mice despite extensive tolerance, but the third group was not detected. Activated MBP121-150-specific T cells induce EAE in wild-type mice. Thus, encephalitogenic T cells that escape tolerance either recognize short-lived peptide/MHC complexes or express TCRs with unique specificities for stable complexes.