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Background: There has been widespread interest in medical errors since the publication of To Err Is Human: Building a Safer Health System by the Institute of Medicine in 2000. The Patient Safety Committee of the American Academy of Orthopaedic Surgeons has compiled the results of a member survey to identify trends in orthopaedic errors that would help to direct quality assurance efforts.Methods: Surveys were sent to 5540 Academy fellows, and 917 were returned (a response rate of 16.6%), with 53% (483) reporting an observed medical error in the previous six months.Results: A general classification of errors showed equipment (29%) and communication (24.7%) errors with the highest frequency. Medication errors (9.7%) and wrong-site surgery (5.6%) represented serious potential patient harm. Two deaths were reported, and both involved narcotic administration errors. By location, 78% of errors occurred in the hospital (54% in the surgery suite and 10% in the patient room or floor). The reporting orthopaedic surgeon was involved in 60% of the errors; a nurse, in 37%; another orthopaedic surgeon, in 19%; other physicians, in 16%; and house staff, in 13%. Wrong-site surgeries involved the wrong side (59%); another wrong site, e.g., the wrong digit on the correct side (23%); the wrong procedure (14%); or the wrong patient (5% of the time). The most frequent anatomic locations were the knee and the fingers and/or hand (35% for each), the foot and/or ankle (15%), followed by the distal end of the femur (10%) and the spine (5%).Conclusions: Medical errors continue to occur and therefore represent a threat to patient safety. Quality assurance efforts and more refined research can be addressed toward areas with higher error occurrence (equipment and communication) and high risk (medication and wrong-site surgery). [ABSTRACT FROM AUTHOR]

The effect of rofecoxib, a highly selective cyclooxygenase (COX)-2 inhibitor, on the pharmacokinetics of ethinyl estradiol (EE) and norethindrone (NET), two common components of a combination oral contraceptive product, was examined. A double-blind, two-period crossover study was conducted in 18 healthy women who received ORTHO-NOVUM 1/35, a combination of EE (35 microg) and NET (1 mg), concurrently for 14 days with either 175 mg rofecoxib or matching placebo during two consecutive menstrual cycles. Plasma was sampled for EE, NET, sex hormone binding globulin (SHBG), and albumin. The AUC(0-24 h) geometric mean ratio (GMR: rofecoxib/placebo) with corresponding 90% confidence interval (CI) of EE and NET was 1.13 (1.06, 1.19) and 1.18 (1.13, 1.24), respectively. The Cmax GMR of EE and NET was 1.06 (0.98, 1.16) and 1.04 (0.99, 1.09), respectively. In each case, the 90% CIs satisfied the predefined bioequivalence limits of (0.80, 1.25). Measures of SHBG and albumin and routine clinical and laboratory safety parameters showed no clinically meaningful changes. The addition of rofecoxib to the oral contraceptive was not associated with any clinically important changes in EE or NET pharmacokinetics and thus would not be anticipated to influence the efficacy of this contraceptive regimen. [ABSTRACT FROM AUTHOR]

Abstract Background Many older people in long-term care do not receive evidence-based diagnosis or management for heart failure; it is not known whether this can be achieved for this population. We initiated an onsite heart failure service, compared with ‘usual care’ with the aim of establishing the feasibility of accurate diagnosis and appropriate management. Methods A pilot randomised controlled trial which randomised residents from 33 care facilities in North-East England with left ventricular systolic dysfunction (LVSD) to usual care or an onsite heart failure service. The primary outcome was the optimum prescription of angiotensin-converting enzyme inhibitors and beta-adrenergic antagonists at 6 months. Results Of 399 echocardiographically-screened residents aged 65–100 years, 30 subjects with LVSD were eligible; 28 (93%) consented and were randomised (HF service: 16; routine care: 12). Groups were similar at baseline; six month follow-up was completed for 25 patients (89%); 3 (11%) patients died. Results for the primary outcome were not statistically significant but there was a consistent pattern of increased drug use and titration to optimum dose in the intervention group (21% compared to 0% receiving routine care, p=0.250). Hospitalisation rates, quality of life and mortality at 6 months were similar between groups. Conclusions This study demonstrated the feasibility of an on-site heart failure service for older long-term care populations. Optimisation of medication appeared possible without adversely affecting quality of life; this questions clinicians’ concerns about adverse effects in this group. This has international implications for managing such patients. These methods should be replicated in a large-scale study to quantify the scale of benefit. Trial registration ISRCTN19781227 http://www.controlled-trials.com/ISRCTN19781227

Purpose: This study investigated metacarpal fracture occurrences, characteristics, treatments, and return-to-play times for National Football League (NFL) athletes., Methods: NFL players who sustained metacarpal fractures during the 2012 to 2018 seasons were reviewed. All players on the 32 NFL team active rosters with metacarpal fractures recorded through the NFL Injury Database were included. Player age, time in the league, player position, injury setting, injury mechanism, fractured ray, management, and return-to-play were recorded., Results: There were 208 injury occurrences resulting in 1 or more metacarpal fractures, identified in 205 players. Of these, 81 (39%) injuries were operated. Return-to-play data were available for 173 (83%) injured players. The median return-to-play time for all athletes was 15 days (interquartile range, 1-55 days). Of the injured players, 130 (71%) missed time but returned the same season. Within this 130-player subset, 69 (53%) were treated nonsurgically and 61 (47%) operatively with median return-to-play times of 16 days (interquartile range, 6-30 days) and 20 days (interquartile range, 16-42 days) respectively. Eighteen individuals in this 130-player subgroup sustained a thumb metacarpal fracture. The return-to-play time was slower for patients sustaining thumb metacarpal fractures compared to other metacarpal fractures, and was significantly longer (median, 55 days) following nonsurgical treatment of thumb fractures compared with operative intervention (median, 24 days). A regression analysis revealed no trend or difference in return to football with respect to player age, time in the league, injury setting (practice vs game), injury mechanism, articular involvement, multiple concomitant injuries, or player position., Conclusions: Most NFL players who sustain metacarpal fractures miss less than 3 weeks and return to play the same season. The only variables that lessen the return-to-play time are involvement of lesser digit metacarpals and operative intervention for treatment of thumb metacarpal fractures., Type of Study/level of Evidence: Prognostic IV., (Copyright © 2023 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Social interactions define the human experience, but these integral behaviors are disrupted in many psychiatric disorders. Social behaviors have evolved over millennia, and neuromodulatory systems that promote social behavior in invertebrates are also present in mammalian brains. One such conserved neuromodulator, neuropeptide Y (NPY), acts through several receptors including the Y1r, Y2r, and Y5r. These receptors are present in brain regions that control social behavior, including the nucleus accumbens (NAc). However, whether NPY modulates NAc neurotransmission is unknown. Using whole-cell patch-clamp electrophysiology of NAc neurons, we find that multiple NPY receptors regulate excitatory synaptic transmission in a cell-type specific manner. At excitatory synapses onto D1+ MSNs, Y1r activity enhances transmission while Y2r suppresses transmission. At excitatory synapses onto D1- MSNs, Y5r activity enhances transmission while Y2r suppresses transmission. Directly infusing NPY or the Y1r agonist [Leu 31 , Pro 34 ]-NPY into the NAc significantly increases social interaction with an unfamiliar conspecific. Inhibition of an enzyme that breaks down NPY, dipeptidyl peptidase IV (DPP-IV), shifts the effect of NPY on D1+ MSNs to a Y1r dominated phenotype. Together, these results increase our understanding of how NPY regulates neurotransmission in the NAc and identify a novel mechanism underlying the control of social behavior. Further, they reveal a potential strategy to shift NPY signaling for therapeutic gain., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/G689 ).

Injury of the scapholunate ligament (SLL) complex can lead to scapholunate dissociation, characterized by scapholunate interval widening and volar rotary subluxation of the scaphoid. Loss of the mechanical linkage between the scaphoid and lunate results in carpal instability and eventual scapholunate advanced collapse (SLAC) arthropathy. SLL complex injuries vary from acute and traumatic to chronic and degenerative. A staging system can be used to guide treatment options for these injuries on the basis of the reparability of the SLL dorsal band, carpal alignment and malalignment reducibility, and cartilage damage. Preoperative imaging with radiography and MRI is a component of injury staging and aids in planning surgical procedures. If the SLL dorsal band is reparable, then direct primary ligament repair with dorsal capsulodesis or dorsal intercarpal (DIC) ligament transfer can be performed. If the SLL dorsal band is irreparable with normal alignment or reducible malalignment, then reconstruction can be performed. In the setting of irreducible malalignment or SLAC arthropathy, a salvage procedure can be performed. Knowledge of SLL primary repair and various reconstruction techniques is important not only when evaluating postoperative images but also for accurate description of SLL injuries and aiding the surgeon in treatment planning. The authors present the normal anatomy of the SLL complex, a staging classification of SLL injury with radiographic and MRI findings, and common surgical procedures. Special attention is given to the operative techniques and postoperative imaging appearances of primary SLL repair with DIC ligament transfer and modified Brunelli reconstruction. © RSNA, 2021.

Few studies have related the surface electromyogram (EMG) of forearm muscles to two degree of freedom (DoF) hand-wrist forces; ones that have, used large high-density electrode arrays that are impractical for most applied biomechanics research. Hence, we researched EMG-force in two DoFs-hand open-close paired with one wrist DoF-using as few as four conventional electrodes, comparing equidistant placement about the forearm to optimized site selection. Nine subjects produced 1-DoF and 2-DoF uniformly distributed random forces (bandlimited to 0.75 Hz) up to 30% maximum voluntary contraction (MVC). EMG standard deviation (EMGσ) was related to force offline using linear dynamic regression models. For 1-DoF forces, average RMS errors using two optimally-sited electrodes ranged from 8.3 to 9.0 %MVC, depending on the DoF. For 2-DoFs, overall performance was best when training from both 1- and 2-DoF trials, giving average RMS errors using four optimally-sited electrodes of 9.2 %MVC for each DoF pair (hand open-close paired with one wrist DoF). For each model, additional optimally-sited electrodes showed little statistical improvement. Electrodes placed equidistant performed noticeably poorer than an equal number of electrodes that were optimally sited. The results suggest that reliable 2-DoF hand-wrist EMG-force with a small number of electrodes may be feasible., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare condition in which congenital anomalies result in a multitude of defects that affect many systems of the body. These defects can involve the eyes, skin, teeth, and cardiovascular, skeletal, and gastrointestinal systems. There have been many associated abnormalities reported in the literature. An appreciation of the clinical presentation of Goltz syndrome is important because physicians rely heavily on recognition of key physical characteristics in order to help make a diagnosis. In this report, we summarize the clinical findings observed when we were afforded the unique opportunity to interview and physically examine 19 patients, the largest group of individuals with Goltz syndrome brought together in one place to date. The findings are intended to characterize the orthopedic phenotypic manifestations of Goltz syndrome. This collection of data revealed that the most common orthopedic findings were syndactyly (68%), ectrodactyly (68%), leg length discrepancy (57%), and reduction defects of long bones (52%). Nail irregularities were present in 89% of the patients seen., (© 2016 Wiley Periodicals, Inc.)

Purpose: To determine biomechanical differences between a fixed-angle locking volar titanium plate (VariAx; Stryker, Kalamazoo, MI) and a fixed-angle compression locking volar stainless steel plate (CoverLoc Volar Plate; Tornier, Amsterdam, Netherlands) in the fixation of simulated AO C3 distal radius fractures., Methods: Eighteen cadaveric upper extremities (9 matched pairs) with an average age of 54 years were tested. A 4-part AO C3 fracture pattern was created in each specimen. The fractures were reduced under direct vision and fixed with either the fixed-angle locking volar titanium plate or the fixed-angle compression locking volar stainless steel plate. Motion tracking analysis was then performed while the specimens underwent cyclic loading. Changes in displacement, rotation, load to failure, and mode of failure were recorded., Results: The fragments, when secured with the fixed-angle compression locking stainless steel construct, demonstrated less displacement and rotation than the fragments secured with the fixed-angle locking titanium plate under physiological loading conditions. In the fixed-angle compression locking stainless steel group, aggregate displacement and rotation of fracture fragments were 5 mm and 3° less, respectively, than those for the fixed-angle locking titanium group. The differences between axial loads at mechanical failure and stiffness were not statistically significant. The compression locking stainless steel group showed no trend in mode of failure, and the locking titanium plate group failed most often by articular fixation failure (5 of 9 specimens)., Conclusions: The fixed-angle compression locking stainless steel volar plate may result in less displacement and rotation of fracture fragments in the fixation of AO C3 distal radius fractures than fixation by the fixed-angle locking volar titanium plate. However, there were no differences between the plates in mechanical load to failure and stiffness., Clinical Relevance: Fixation of distal radius AO C3 fracture patterns with the fixed-angle compression locking stainless steel plate may provide improved stability of fracture fragments., (Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Background: Varied and fragmented care plans undertaken by different practitioners currently expose surgical patients to lapses in expected care, increase the chance for operational mistakes and accidents, and often result in unnecessary care. The Perioperative Surgical Home has thus been proposed by the American Society of Anesthesiologists and other stakeholders as an innovative, patient-centered, surgical continuity of care model that incorporates shared decision making. Topics central to the debate about an anesthesiology-based Perioperative Surgical Home include: holding the gains made in anesthesia-related patient safety; impacting surgical morbidity and mortality, including failure-to-rescue; achieving healthcare outcome metrics; assimilating comparative effectiveness research into the model; establishing necessary audit and data collection; a comparison with the hospitalist model of perioperative care; the perspective of the surgeon; the benefits of the Perioperative Surgical Home to the specialty of anesthesiology; and its associated healthcare economic advantages., Discussion: Improving surgical morbidity and mortality mandates a more comprehensive and integrated approach to the management of surgical patients. In their expanded capacity as the surgical patient's "perioperativist," anesthesiologists can play a key role in compliance with broader set of process measures, thus becoming a more vital and valuable provider from the patient, administrator, and payer perspective. The robust perioperative databases created within the Perioperative Surgical Home present new opportunities for health services and population-level research. The Perioperative Surgical Home is not intended to replace the surgeon's patient care responsibility, but rather leverage the abilities of the entire perioperative care team in the service of the patient. To achieve this goal, it will be necessary to expand the core knowledge, skills, and experience of anesthesiologists. Anesthesiologists will need to view becoming perioperative physicians as an expansion of the specialty, rather than an abdication of their traditional intraoperative role. The Perioperative Surgical Home will need to create strategic added value for a health system and payers. This added value will strengthen the position of anesthesiologists as they navigate and negotiate in the face of finite, if not decreasing fiscal resources., Summary: Broadening the anesthesiologist's scope of practice via the Perioperative Surgical Home may promote standardization and improve clinical outcomes and decrease resource utilization by providing greater patient-centered continuity of care throughout the preoperative, intraoperative, and postoperative periods.

Unlabelled: The FiberLoop suture has been developed as a double stranded, double-armed suture of FiberWire, but has not been previously studied. This is a comparison study of FiberLoop, FiberWire, and Ethibond., Methods: Six groups of bovine tendons were randomly sorted for testing. They were cut and repaired using FiberWire, FiberLoop, and Ethibond with modified Kessler and modified Krackow repair techniques. A 4-0 core suture was used and tested to failure., Results: Both FiberLoop and FiberWire were significantly stronger than Ethibond regardless of the repair technique used. There was no difference between the nonlocking and locking repair technique in any of the suture groups. However, the nonlocking technique failed by tissue pull through while the locking technique failed by suture breakage., Conclusions: The FiberLoop suture and the FiberWire suture were significantly stronger than the Ethibond suture. Additionally, this study shows that the 4-0 suture is of adequate strength to repair a tendon injury. The double-armed Fiberloop may translate into quicker tendon repairs without sacrificing strength.

Background and Purpose: Improvement in axonal regeneration may lead to the development of longer nerve grafts and improved outcomes for patients with peripheral nerve injury. Although the use of acellular nerve grafts has been well documented (Groves et al, Exp Neurol. 2005;195:278-292; Krekoski et al, J Neurosci. 2001;21:6206-6213; Massey et al, Exp Neurol. 2008;209:426-445; Neubauer et al, Exp Neurol. 2007;207:163-170; Zuo et al, Exp Neurol. 2002;176:221-228), less is known about the ability of neurotrophic factors to enhance axonal regeneration. This study evaluates axonal ingrowth augmentation using acellular, chondroitinase-treated nerve grafts doped with nerve growth factor (NGF)., Methods: Acellular chondroitinase-treated murine nerve grafts were placed in experimental (NGF-treated grafts) and control (carrier-only grafts) rats. Five days after implantation, axonal regeneration was assessed by immunocytochemistry along with digital image analysis., Results: Higher axon count was observed throughout the length of the nerve in the NGF group (P < 0.0001), peaking at 3 mm from proximal repair (P = 0.02). Although the NGF group displayed a higher axon count per slice, the mean diameter of individual NGF axons was smaller (P < 0.0001), potentially consistent with induction of sensory axons (Rich et al, J Neurocytol. 1987;16:261-268; Sofroniew et al, Annu Rev Neurosci. 2001;24:1217-1128; Yip et al, J Neurosci. 1984;4:2986-2992)., Conclusion: The simple technique of doping acellular, chondroitinase-treated nerve grafts with NGF can augment axonal ingrowth and possibly preferentially induce sensory axons.

The purpose of this study was to evaluate the results of excision of the ulnar slip of the flexor digitorum superficialis tendon, with or without A1 pulley release, for the treatment of trigger finger in diabetic patients. We performed a retrospective review with long-term follow-up examinations. Short-term data was obtained on 18 consecutive patients (37 fingers). Long-term information was collected on 14 of these patients (24 fingers) at an average of 48 months after surgery. Short-term follow-up revealed average proximal interphalangeal joint (PIP) flexion of 81 degrees . One patient had slight residual triggering. At long-term follow-up, 93% of patients were completely or very satisfied with the procedure. Total active finger motion averaged 218 degrees , and PIP extension deficit averaged less than 5 degrees . Pinch strength was equal to the contralateral corresponding finger. There were no significant complications. One finger had minimal residual triggering. In conclusion, this procedure is a safe and effective treatment for the often-difficult problem of stenosing flexor tenosynovitis in the diabetic patient.

Symptomatic post-traumatic arthritis affecting the finger CMC joints is less common than might otherwise be expected based on the frequency of injury, especially to the fifth CMC joint. For the fifth CMC joint, the shallow concavoconvex articulation combined with the typical fracture location may provide a protective effect. Non-operative measures are typically successful, except in cases of missed fracture/dislocations and symptomatic joint instability. In these instances, re-construction emphasizes stability first, with an eye toward mobility for the ulnar column. It is common to detect a bony prominence in the region of the dorsal second and third CMC joints during examination of the hand. In most instances, the projection is asymptomatic and likely represents an os styloideum [18]. When painful and unresponsive to nonoperative treatments, this carpometacarpal boss can be excised surgically.

The evidence is clear that anatomic reinsertion is the best treatment for an active, compliant patient with an acute distal biceps rupture or a subacute rupture without significant proximal retraction of the tendon. Patients with partial tears and chronic ruptures require surgical attention when persistently symptomatic. Biceps tenodesis through dual incisions or a single anterior incision is a safe, highly reliable, and effective operation. The posterior interosseous nerve is potentially at risk with either approach. This risk is minimized by avoiding exposure and retraction of the nerve. Heterotopic ossification and subsequent proximal radio-ulnar synostosis are reported complications of the two-incision technique. The incidence of this devastating complication has been reduced, but not eliminated, by using a limited posterior forearm muscle-splitting incision and by not exposing the ulna. It is the authors' belief that a single anterior incision with suture anchor fixation of the distal biceps (in the manner described herein) is the surgical treatment of choice for most distal biceps ruptures. Compared with the two-incision method, the posterior interosseous nerve is at no more risk and the chance of heterotopic ossification is diminished. The secure fixation obtained and the limited surgical exposure required allow for early mobilization and rapid return of function.

Lythrum salicaria L., purple loosestrife, an invasive Eurasian perennial, is degrading wetlands across temperate North America. Chemical, physical, and mechanical methods failed to provide long-term control. Therefore, four host-specific insect species (two leaf feeders, a root feeder, and a flower feeder) were introduced as biological control agents. To increase the availability of adults of the root feeding weevil Hylobius transversovittatus Goeze for field releases, we developed a semiartificial diet. Suitability of different diet formulations (varying vitamin mixes, salt mixes, antimicrobials, water content, root content) and temperatures for larval development were evaluated. We also monitored how rearing on artificial diet and the number of larvae per container affected larval development time, larval survival, adult weight, and incidences of deformities. Rearing larvae on artificial diet reduced development time from 1-2 yr to 2-3 mo. Larval development was fastest and survival rates highest under constant temperatures of 25 degrees C. Hatch rate and larval survival decreased if eggs were surface sterilized. Using FABCO antimicrobials could not prevent fungal contamination; use of methyl paraben and sorbic acid was successful in suppressing fungal and bacterial growth throughout larval development time to <10%. The moisture content of the diet did not significantly affect larval survival, development, or adult weight. Decreasing the proportion of purple loosestrife roots in the diet reduced adult weight and the proportion of larvae completing development, and increased development time; no larvae were able to complete development in root-free diet. With an increase in the number of larvae per cup, survival rates were reduced. The experiments revealed a female biased sex ratio: females consistently developed faster and were heavier than males. Incidence of adult deformities was consistently below 5%. Increased availability of adults for field release as a result of mass production using the semiartificial diet will accelerate the biocontrol program targeting purple loosestrife. We are able to produce several hundred weevils per week and have adapted the diet to rear other root-feeding weevils.

Purple loosestrife, Lythrum salicaria L., an invasive Eurasian perennial, is degrading wetlands across temperate North America. Because conventional control methods have proven ineffective, current emphasis is on the introduction and release of host-specific biological control agents. To increase the availability of control agents for distribution and thus the potential for faster control, mass rearing techniques for 2 leaf beetles, Galerucella calmariensis L. and G. pusilla Duftschmidt, were developed under greenhouse and field conditions. To evaluate the success of various rearing techniques on the number of beetles produced and the effect of these methods on offspring quality, female fecundity, larval development, and adult survival were monitored. Survival of adults maintained at 4 degrees C was approximately 60% and was independent of the type of material used for storage, duration of overwintering, and number of beetles per container. Survival rates increased with increasing numbers of dry stems offered as an overwintering substrate. Females in smaller cages had significantly higher oviposition rates, and with an increase in the number of beetles per cage, female fecundity doubled. Continuous rearing in the greenhouse reduced female fecundity. Allowing beetles to overwinter significantly improved fecundity and rearing efficiency, independent of whether beetles overwintered in a controlled environment or in the field. Field rearings consistently produced 2-5 times more offspring with higher survival than greenhouse rearings.

The distal radio-ulnar joint (DRUJ) is often the site of persistent symptoms after malunion of distal radius fractures. These malunions alter load transfer across the ulnocarpal joint, disturb DRUJ kinematics, and result in joint incongruity at the sigmoid notch. Treatment of distal radius malunions must not only correct position of the radial platform and joint incongruity but also restore anatomic relationship at the DRUJ. A systematic approach to the surgical reconstruction of these multiplanar deformities using clinical and radiographic parameters is outlined.

Devitalized extracts from cultured human osteosarcoma cells (Saos-2) can induce ectopic bone formation. The ability of an extract from Saos-2 cells to stimulate healing of an operatively created four-millimeter defect in the femoral diaphyses of rats was compared with that of collagen and that of autogenous bone graft. Forty adult rats were randomized into four groups of ten each. In Group 1 (controls), no material was placed in the defect; in Group 2, the defect was filled with pure bovine collagen; in Group 3, it was filled with autogenous graft obtained by morseling of the resected segment of the femur; and in Group 4, it was filled with ten milligrams of extract from Saos-2 cells that was mixed with an equal amount of bovine collagen. Five rats from each group were killed at four weeks and the remaining five, at eight weeks. Each femoral defect was analyzed radiographically and histologically for osseous healing. There was no evidence of healing at either four or eight weeks in Groups 1 and 2. Although there was some new-bone formation in Group 3, none of the defects had united at eight weeks. There was early, almost complete union in all five four-week specimens in Group 4 and complete healing of the defect in four of the five rats assessed at eight weeks. The Saos-2 cell extract was found to be the most effective agent, promoting union by mature lamellar bone within eight weeks.

Saos-2 cultured human osteosarcoma cells contain an extractable bone inducing agent that can induce heterotopic bone in the muscle of Nu/Nu mice. A semipurified GuHCl extract of Saos-2 cells also can promote healing and complete bony union in otherwise non-healing surgically induced defects of rat femur. Northern blot analyses indicate expression of mRNAs for bone morphogenetic proteins (BMP)-1, 2, 3, 4, 6 and transforming growth factor beta (TGF beta) in Saos-2 cells, and BMP-2, 3, 4, 5, 7 and TGF beta in nonosteoinductive U20S human osteosarcoma cells. Saos-2 cells exceeded U20S cells in expression levels of BMP-1, 3, 4 and TGF beta, whereas U20S cells expressed higher levels of BMP-2, 6 and also expressed trace amounts of BMP-5 and 7 not seen in Saos-2 cells. The authors hypothesize that Saos-2 cells contain an optimal admixture of known bone growth factors plus possible other unknown components that, acting alone or in combination with bone morphogenetic protein and/or TGF beta, can induce bone. Although bone inducing agent-induced heterotopic bones have half lives of only a few weeks, the reparative bone induced by bone inducing agent in femoral defects gives every indication of being permanent and self-sustaining. This suggests a fundamental difference between heterotopic and orthotopic osteoprogenitor cells with those involved in orthotopic bone repair more closely resembling the committed or determined osteoprogenitor cells of marrow as described by Friedenstein.

Release of the transverse carpal ligament is commonly performed and highly successful in the treatment of carpal tunnel syndrome; however, complications do occur and may be broadly classified as errors in diagnosis and surgical technique. Complications range from incomplete division of the transverse carpal ligament to adherence of the flexor tendons. Awareness of possible coexistent diagnoses and treatment complications is important in avoiding and managing complications.

The response of canine lumbar vertebral bone to the application of a stiff transpedicular screw-plate implant from the third to the fifth lumbar vertebra, without arthrodesis, was investigated. Five groups of six dogs each were studied: dogs that had not had an operation (control group); dogs that had had a sham operation, with survival periods of three and six months; and dogs that had received an implant, with survival periods of three and six months. The results were the same in specimens from the control group and the group that had had a sham operation. In the groups that had received an implant, dual-photon absorptiometry revealed an insignificant decrease in bone-mineral content at the bypassed fourth lumbar segment (17 per cent at three months and 12 per cent at six months). When the data for the three and six-month intervals were pooled, the mean decrease in bone-mineral content of 14 per cent was significant. Histomorphic study yielded similar results; the mean decrease in bone-mineral content for the pooled three and six-month specimens was significant (16 per cent). Losses were similar for the ventral and dorsal columns. Histomorphometric analysis also showed a significant (13 per cent) loss of bone-mineral content at the adjacent caudad (sixth lumbar) vertebra for the pooled three and six-month groups. The results of the methods of analysis of loss of bone-mineral content correlated strongly. Under these experimental conditions, a stiff spinal implant caused loss of bone-mineral content of the bypassed vertebral segment, although the loss was less than anticipated and did not increase between three and six months.

We have previously reported that insulin binding is decreased in the olfactory bulb of both heterozygous (Fa/fa) and obese (fa/fa) Zucker rats. In the present study, we measured insulin binding in membranes prepared from the olfactory bulb, cerebral cortex, and hypothalamus of control (Fa/Fa) Wistar Kyoto rats; "fatty" (fa/fa) Wistar Kyoto rats; and phenotypically lean (Fa/?) Wistar Kyoto rats. Insulin binding was decreased in all brain regions, as well as the liver of the obese Wistar Kyoto fa/fa rats. Additionally, insulin binding was decreased in the liver and brain membranes from the Fa/? Wistar Kyoto rats. As most of the Fa/? rats were probably carriers of one 'fa' gene, but the population was only slightly hyperinsulinemic, we conclude that--as in the Zucker rat--it is the presence and expression of the 'fa' gene rather than downregulation which results in the decreased insulin binding. Thus, regulation of the brain insulin receptor appears to be independent of plasma or cerebrospinal fluid insulin levels.