Contralateral Injury Research Articles

Protective effect of sildenafil citrate on contralateral testis injury after unilateral testicular torsion/detorsion

OBJECTIVES:This study was designed to investigate prevention of contralateral testicular injury with sildenafil citrate after unilateral testicular torsion/detorsion.METHODS:Thirty‐seven adult male rats were divided into four groups: sham operated (group 1, n = 7), torsion/detorsion + saline (group 2, n = 10), torsion/detorsion + 0.7 mg of sildenafil citrate (group 3, n = 10) and torsion/detorsion + 1.4 mg of sildenafil citrate (group 4, n = 10). Unilateral testicular torsion was created by rotating the right testis 720° in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. After torsion (2 h) and detorsion (2 h) periods, rats were killed.RESULTS:The level of reduced glutathion (GSH) (p<0.05) and the activities of catalase (p<0.01) and glutathione peroxidase (p<0.05) in the contralateral testis from group 2 were significantly lower and nitric oxide (NO) (p<0.05) level in the contralateral testis were significantly higher than those of group 1. Administration of low‐dose sildenafil citrate (group 3) prevented the increases in malondialdehyde and NO levels and decreases in glutathione peroxidase activities and GSH values induced by testicular torsion. However, administration of high‐dose sildenafil citrate (group 4) had no effect on these testicular parameters (p>0.05). Histopathological changes were detected in groups 2, 3 and 4.CONCLUSION:These results suggest that biochemically and histologically torsion/detorsion injury occurs in the contralateral testis following 2‐h torsion and 2‐h detorsion and that administration of low‐dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular tissue.

Is the ‘Crunch Factor’ an Important Consideration in the Aetiology of Lumbar Spine Pathology in Cricket Fast Bowlers?

The 'crunch factor' is defined as the instantaneous product of lateral flexion and axial rotational velocity of the lumbar spine. It was originally implicated in the development of lumbar spine pathology and lower back pain in golfers and, although empirical evidence supporting or refuting the crunch factor is inconclusive, it remains an intuitively appealing concept that requires further investigation, not only in golf, but also in other sports involving hitting and throwing motions. This article considers whether the crunch factor might be instrumental in the aetiology of contralateral lumbar spine injuries sustained by cricket fast bowlers. Based on recent empirical research, it is argued that the crunch factor could be important in cricket fast bowling especially considering that peak crunch factor appears to occur just after front foot impact when ground reaction forces are known to be at their highest. The crunch factor may also occupy an integral role in lower back injuries sustained in other sports involving unilateral overhead throwing (e.g. javelin throwing) and hitting (e.g. tennis serving) actions where the spatial orientation of the arm at release or impact is largely determined by lateral flexion of the trunk and where the transfer of energy and momentum along the kinetic chain is initiated by a rapid rotation of the pelvis. Further research is required to empirically verify the role of the crunch factor in the development of lower back injuries in cricket fast bowling and sports that involve similar lower trunk mechanics. This research programme should ideally be supported by modelling work examining the stresses imposed on bony, disc and joint structures by lateral flexion and axial rotation motions so that their respective contribution to injury can be identified.

Biomechanical Measures during Landing and Postural Stability Predict Second Anterior Cruciate Ligament Injury after Anterior Cruciate Ligament Reconstruction and Return to Sport

Background Athletes who return to sport participation after anterior cruciate ligament reconstruction (ACLR) have a higher risk of a second anterior cruciate ligament injury (either reinjury or contralateral injury) compared with non—anterior cruciate ligament— injured athletes. Hypotheses Prospective measures of neuromuscular control and postural stability after ACLR will predict relative increased risk for a second anterior cruciate ligament injury. Study Design Cohort study (prognosis); Level of evidence, 2. Methods Fifty-six athletes underwent a prospective biomechanical screening after ACLR using 3-dimensional motion analysis during a drop vertical jump maneuver and postural stability assessment before return to pivoting and cutting sports. After the initial test session, each subject was followed for 12 months for occurrence of a second anterior cruciate ligament injury. Lower extremity joint kinematics, kinetics, and postural stability were assessed and analyzed. Analysis of variance and logistic regression were used to identify predictors of a second anterior cruciate ligament injury. Results Thirteen athletes suffered a subsequent second anterior cruciate ligament injury. Transverse plane hip kinetics and frontal plane knee kinematics during landing, sagittal plane knee moments at landing, and deficits in postural stability predicted a second injury in this population (C statistic = 0.94) with excellent sensitivity (0.92) and specificity (0.88). Specific predictive parameters included an increase in total frontal plane (valgus) movement, greater asymmetry in internal knee extensor moment at initial contact, and a deficit in single-leg postural stability of the involved limb, as measured by the Biodex stability system. Hip rotation moment independently predicted second anterior cruciate ligament injury (C = 0.81) with high sensitivity (0.77) and specificity (0.81). Conclusion Altered neuromuscular control of the hip and knee during a dynamic landing task and postural stability deficits after ACLR are predictors of a second anterior cruciate ligament injury after an athlete is released to return to sport.

Erratum to: Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers

Erratum to: Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers

Arthroscopic removal of a plastic soft drink bottle cap in the knee: a case report

We report a rare case of late knee locking after an open knee injury in a polytrauma patient with a pelvic fracture and a contralateral femoral artery injury. Once the life and limb threatening injuries were addressed, debridement and washout of the knee wound was performed. X-rays and subsequent CT revealed only an undisplaced patella fracture. The patient presented 6 months later to a knee surgeon with recurrent locking. An arthroscopy was performed and a 10 mm plastic soft drink bottle cap was retrieved leading to the immediate resolution of symptoms without complications.Open knee injuries require thorough debridement washout and joint assessment. Late locking should raise the suspicion of an intra-articular loose or foreign body. Arthroscopy is an excellent first line tool in the diagnosis and late management of this unusual problem.

ACL injuries: unanswered questions – are there any solutions?

In their article published in this journal, Sward and co-workers [10] discuss the risk factors for an ACL injury after injury to the contra-lateral knee. It is previously known that the risk is higher for injury to the contra-lateral knee after injury to one knee. The reasons are not very well known, but all what is known is discussed in the abovementioned article. The authors found that there is evidence that shows the risk of sustaining a contra-lateral injury is greater than the risk of a first-time ACL injury. This increased risk should be born in mind when athletes return to sports activities after fist-time ACL injury, especially high-level activity. The authors did not find conclusive evidence in terms of risk factors, like female gender, family history of such injury and a narrow intercondylar notch. More likely are changes in biomechanics, i.e. altered kinematics and neuromuscular factors [1, 10]. This article helps us to focus on how to solve the unanswered questions concerning ACL injuries. The answers might not be easy, but an attempt might be as follows. First and foremost, prevention is a key factor [3–5, 8, 9]. Recent studies have focused on preventive measures and some researchers claim that approximately 50%, i.e. every other ACL injury can be prevented (http://www.ostrc.no). Some even claim higher number, up to 80%. This means that preventive measures must be implemented in normal sports training on every day basis. This is often not easy, as coaches will focus primarily on sports training and not prevention. The problem is that prevention takes time, and it must be a normal part of the every day training. Risk factors must be evaluated and judged on an individual level. One such risk factor is ACL injury to the contra-lateral knee. Due to the risk of permanent disability, for instance the development of osteoarthritis in the medium-term, coaches and physicians involved in sports medicine/traumatology should evaluate every such injury in order to prevent another ACL injury [3, 4, 8, 10]. The second solution might be the timing of surgery, when and if surgery is needed [2, 5–7, 9]. Early reconstruction, before additional injuries to the menisci and cartilage is to be preferred. Early ACL reconstruction, i.e. restoration of the ligament before chronic/recurrent pivoting leads to better restoration of kinematics, i.e. normalization of the rotational movement between tibia and femur. In the long run, normal kinematics might reduce the risk of the development of osteoarthritis in the mediumto longterm. The third solution is concerned with the surgical technique [5–7, 9]. A little more than 20 years ago, ACL reconstructive surgery was revolutionized; when ACL reconstructions were converted from wide open to arthroscopic. This was a major step forward, but time has shown that it was not enough. All knees are not alike and ACL reconstructions cannot be standardized. The same surgery cannot be done on all knees. This has led to increased understanding of individualized surgery. Several surgeons perform double-bundle techniques today. But, doublebundle is technically demanding and might sometimes not be indicated, for instance in patients with small knees. The term anatomic ACL reconstruction has also been popularized, even though it is still not well defined what is meant by anatomic. But, the knowledge and understanding is rapidly increasing. We must remember though that doublebundle ACL reconstruction is not necessarily the same as anatomic ACL reconstruction. What anatomic stands for is as exact restitution of the native ACL as possible. This J. Karlsson (&) Department of Orthopaedics, Sahlgrenska University Hospital, Sahlgrenska Academy, Goteborg, Sweden e-mail: jon.karlsson@telia.com

Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers

Rotational stability of the knee has been traditionally difficult to quantify, limiting the ability of the orthopedic community to determine the potential role of rotational laxity in the etiology of anterior cruciate ligament (ACL) injuries. The purposes of this multicenter cohort study were to evaluate the reliability of a robotic axial rotation measurement system, determine whether the uninjured knees of patients that had previous contralateral ACL reconstruction demonstrated different rotational biomechanical characteristics than a group of healthy volunteers, and determine whether knee rotational biomechanical characteristics differ between male and female non-injured limbs in groups of both healthy volunteers and patients with a previous contralateral ACL injury. Fourteen healthy volunteers and 79 patients with previous unilateral ACL injury participated in this study. Patients were tested using a computerized tibial axial rotation system. Only the normal (non-operated) knee data were used for analysis. In order to assess the reliability of the robotic measurement system, 10 healthy volunteers were tested daily over four consecutive days by four different examiners. Rotational laxity and compliance measures demonstrated excellent reliability (ICC=0.97). Patients with a contralateral ACL injury demonstrated significantly increased tibial internal rotation (20.6° vs. 11.4°, P<0.001) and reduced external rotation (16.7° vs. 26.6°, P<0.001) compared to healthy volunteers. Females demonstrated significantly increased internal and external rotation, as well as significantly increased rotational compliance compared with males (P<0.05). Computer-assisted measurement techniques may offer clinicians an accurate, reliable, non-invasive method to select the most appropriate preventative or surgical interventions for patients with increased knee rotational laxity.

The morphological evaluation of ipsilateral and contralateral vasa deferentia in a rat model of unilateral spermatic cord torsion

Spermatic cord torsion is a surgical emergency that requires early intervention to protect the effected testicle. The literature review about this ischemic reperfusion (I/R) injury reveals not only ipsilateral, but also contralateral testicular and epididymal injuries in a broad fashion. However, there is no data about vas deferens injury related with this surgical emergency. The aim of the study is to evaluate the morphological changes of the vas deferens due to testicular I/R injury. Eighteen Wistar-Albino rats were allocated to three groups. Bilateral vasa deferentia of control group (Gr C, n = 6) were harvested without any surgical intervention. The torsion group was subjected to 2 h torsion and 2 h detorsion of the left testicle (Gr T, n = 6) and the third group underwent sham operations (Gr S, n = 6). Bilateral vasa deferentia of Gr T and S were harvested after surgery. The either side of the vas deferens was divided into three equal segments and these regions (adjacent to urinary bladder, medial and adjacent to testicle) were evaluated histopathologically. The electron microscopic evaluation of bilateral vasa deferentia of Gr T revealed different degrees of degeneration on either side. The region adjacent to testicle of the contralateral vas deferens was the most effected segment when compared with the other segments. In the light of these findings, it can be said that testicular I/R injury effects not only testis and epididymis, but also the adjacent vas deferens. This effect seems to be bilateral, like the testis and epididymis injury. Moreover, it mostly seems to depend on the apoptotic processes.

MP-12.10: The Effect of Orchiectomy on Contralateral Testicular Injury after Testicular Torsion in the Rat

MP-12.10: The Effect of Orchiectomy on Contralateral Testicular Injury after Testicular Torsion in the Rat

Outcome after knee dislocation

Knee dislocations are limb-threatening injuries and, if not treated appropriately, may result in significant functional disability. Currently, there is a paucity of high-quality outcome studies in the literature to help guide optimal treatment strategies for these complex injuries [2]. Highlevel studies are extremely difficult to achieve because of the heterogeneity of the study population and the wide variation in injury patterns. Assessing outcomes is equally difficult as a large number of knee dislocation patients sustain polytrauma and may have other ipsilateral and contralateral limb injuries. The literature to date has focused primarily on case series and surgical technique, with very few papers comparing treatment strategies or reporting on outcomes. Even the definition of a knee dislocation, in terms of the number of ligaments ruptured, remains contested. Many authors suggest that a minimum of three ligaments must be disrupted, while others contend that two ruptured ligaments (the PCL-intact knee dislocation) still constitute a dislocated knee. Wide variations in the definition of ‘‘acute’’ reconstruction are also noted, and no standardized functional scoring system has been universally reported. All of these factors make interpretation of the available literature extremely difficult. Several controversies persist regarding treatment of the dislocated knee. Surgical timing, graft selection, repair versus reconstruction of the medial and lateral structures, surgical techniques, and postoperative rehabilitation remain topics of debate. We recently performed a systematic review of the literature and found evidence to support early [\3 weeks] operative intervention of all damaged ligamentous structures compared to nonoperative or delayed intervention. We also found a higher rate of revision for repair as opposed to reconstruction for the fibular collateral ligament (FCL) and posterolateral corner (PLC) [2]. In their prospective level II study [1], the authors found worse outcomes with high-energy compared to low-energy injured knees, and four ligaments compared to two or three ligament-injured knees. No change in outcomes was observed between patients that did or did not sustain neurovascular injury. In addition, they found no difference with acute (\2 weeks) compared to chronic ([2 weeks) surgical intervention. A high level of osteoarthritis (87%) was also found in their series, consistent with previous reports [6]. Surgical techniques and postoperative rehabilitation protocols continue to evolve. A steep learning curve was evident in our own practice with regard to repair and/or reconstruction methods, and over time, we have become less aggressive with early range of motion. In this series, the authors went through similar changes with postoperative rehabilitation and employed numerous surgical techniques for repair and/or reconstruction, in particular for medialand lateral-sided injuries. This indicates the lack of standardization for surgical techniques and the need for better evidence. One of, if not the most important points to highlight is the issue of vascular assessment. We are aware of cases in which an unrecognized complete popliteal artery thrombosis occurred after a knee dislocation. At the time of presentation, radiographs were unremarkable, and the patients had a palpable dorsalis pedis pulse. No further B. A. Levy (&) Department of Orthopaedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA e-mail: Levy.Bruce@mayo.edu

Contralateral deafness post head injury without temporal bone fractures

We report an unusual case of contralateral deafness in a 31-year-old man after an uncomplicated blunt force head injury. The patient was presented with a left-sided head injury and complained of profound deafness in his right ear, dysequilibrium, and vertigo. Pure tone audiogram revealed total sensorineural deafness in the right ear. A high-definition computed tomography scan demonstrated no radiological evidence of bony injuries or a fistula. His dysequilibrium had improved 2 months later, but his vertigo and hearing loss persisted. We will discuss several possible mechanisms of injury that may result in deafness after head injury without bony fractures. The literature has been reviewed. Although deafness is not an uncommon complication of head injuries, its presentation in the contralateral ear in the absence of temporal bone fractures following head injury has not been reported before in the medical literature.

Acute Subdural Hematoma Because of Boxing

To identify factors determining the clinical characteristics and prognosis of acute subdural hematoma (ASDH) arising from boxing injuries by comparing with ASDH due to any nonboxing cause. Two groups were selected for this study: 10 patients with ASDH because of boxing injuries and 26 patients with nonboxer ASDH. All of the patients underwent neurologic examination by neurosurgeons. Primary resuscitation and stabilization as well as operative therapy were performed to all patients according to the European Brain Injury Consortium Guidelines. Two groups were compared in terms of age, the Glasgow Coma Scale at admission, neurologic findings, craniogram and brain computed tomography scan findings, operative findings, and prognosis. As potential prognostic indicators for boxers, the time interval until surgery, the Glasgow Outcome Scale, hematoma thickness, midline shift, and the site of bleeding were analyzed. The characteristics of patients because of boxing injuries are that patients were younger, had lucid interval, and had no cerebral contusion or contralateral brain injury. There was no significant difference in initial Glasgow Coma Scale, hematoma thickness, midline shift, and their prognosis. The most peculiar clinical presentation of boxers' ASDH was that all bleedings were limited from "bridging veins" or "cortical veins." The prognosis of boxers was most closely correlated with the site of bleeding (r2 = 0.81; p = 0.0001) and the midline shift (r2 = 0.67; p = 0.007). Our study shows that ASDH because of boxing is characterized by bleeding from bridging or cortical veins, and that the site of bleeding is a significant determinant of their prognosis.

90. Sensory recovery after C7 sacrifice for treatment of contra-lateral brachial plexus injury

90. Sensory recovery after C7 sacrifice for treatment of contra-lateral brachial plexus injury

Glucocorticoid Inhibits Bone Regeneration after Osteonecrosis of the Femoral Head in Aged Female Rats

Idiopathic osteonecrosis of the femoral head (ION) is a painful disease of the hip, the pathogenic mechanism of which is still unclear. The most common extraneous factor is steroid treatment. Steroids have inhibiting effects on bone formation and resorption. When bone regenerative treatments are indicated for ION patients who are exposed to steroids, we cannot ignore the effects of corticosteroid itself on bone healing. The aim of this study was to investigate the effects of glucocorticoid on bone regeneration after osteonecrosis of the femoral head in a rat model. Osteonecrosis was induced surgically on the left femoral heads of aged female rats (about 6 months old) on day 0. Methylprednisolone sodium succinate (MPSS) or normal saline was administrated at a dose of 100 mg/kg/day from day 7 to 11. Femoral heads were analyzed histologically. There were no pathological findings in the right femoral heads of the MPSS-treated and saline-treated rats, as control for the contralateral injury. The newly formed bone volume and the osteoclast number were significantly smaller in the MPSS-treated group. The normal bone marrow was regenerated in the saline-treated group, whereas most of the bone marrow space still contained fibroblast-like spindle-shaped cells in the MPSS-treated group on day 42. Alkaline phosphatase-positive cells were only seen in the areas around the regenerated bone marrow cavities. Thus, MPSS inhibits bone formation by suppressing osteoblast proliferation and resorption by suppressing the recruitment of osteoclast precursors. These findings may be useful when designing treatments for ION patients exposed to steroids.

Effect of Naloxone on Oxidative Stress and Testicular Injury due to Spermatic Vessel Ligation of Rat Testis

Aims: Two-stage Fowler-Stephens orchiopexy has been accompanied by testicular atrophy in some cases but neither of the mechanisms responsible for testicular injury are clear, nor is there an effective agent that might prevent this injury. In this study we aimed to investigate the long-term effects of naloxone, a morphine antagonist, on testicular histopathology and oxidative stress after spermatic vessel ligation (SVL) in rats. Methods: 32 prepubertal rats were randomly divided into four equal groups: group 1: control (only bilateral orchiectomies were performed); group 2: sham-operated group; group 3: SVL, and group 4: SVL+naloxone (1 mg/kg twice daily for 1 month). One month postoperatively, bilateral orchiectomies were performed to evaluate histopathologic findings and measurement of malondialdehyde (MDA) and nitric oxide (NO) levels. Results: Considering group 3, left SVL resulted in significant tissue damage in both testes, more severe in the ipsilateral testis. The SVL resulted in a significant increase in testicular MDA levels of both testes in this group (p < 0.05). While the ipsilateral testicular NO levels of groups 2 and 3 were significantly lower than of group 1 (p < 0.05), the contralateral testicular NO levels of all these groups were similar. After naloxone therapy, while there was no significant improvement in ipsilateral testicular histopathology (p > 0.05), the contralateral testicular histopathology improved significantly (p < 0.05). However, naloxone did not change either testicular MDA or NO levels. Conclusions: The SVL led to bilateral testicular injury, and oxidative stress may be a reason for this injury. Naloxone significantly improved contralateral testicular injury without showing any antioxidative effect.

The Contralateral Knee Joint in Cruciate Ligament Deficiency

Background Patients with unilateral ligament deficiency are believed to have altered kinematics of the contralateral knee, increasing the risk of contralateral joint injury. Therefore, the contralateral knees might not be a reliable normal kinematic control. Purpose To compare the in vivo kinematics of the uninjured contralateral knees of patients with anterior or posterior cruciate ligament deficiency with knee kinematics of age-matched patients without joint injury. Study Design Controlled laboratory study. Methods Ten subjects with bilateral healthy knees, 10 patients with acute unilateral anterior cruciate ligament injury, and 10 with acute unilateral posterior cruciate ligament injury participated in this study. Kinematics were measured from 0° to 90° of flexion using imaging and 3-dimensional modeling. Results No significant differences were found across the groups in all rotations and translations during weightbearing flexion (P > .9). Conclusion Patients with unilateral cruciate ligament deficiency did not alter kinematics of the contralateral uninjured knee during weightbearing flexion. In addition, these findings suggest that the included patients with anterior cruciate ligament or posterior cruciate ligament deficiency did not have preexisting abnormal kinematics of the knee. Clinical Relevance As the contralateral joint kinematics of the injured patients were not affected by the ipsilateral ligament injury in the short term, physicians and researchers might use the contralateral knee as a reliable normal kinematic control.

New guidelines for drive-by renal arteriography may lead to an unjustifiable increase in percutaneous intervention

Narrowing of the lumen of the renal artery is termed renal artery stenosis (RAS) and can be a cause of hypertension and chronic kidney disease (CKD).1 When hypertension is caused...

Disease-Specific Gender Differences Among Total Knee Arthroplasty Candidates

Background： Women with knee osteoarthritis are less likely to undergo joint replacement despite greater selfreported disability. The primary aim of the present study was to assess gender differences in the type and magnitude of osteoarthritis-related impairment prior to knee arthrop lasty. Methods： Two hundred and twenty-one knee arthroplasty candidates （ninety-five men and 126 women） and forty-four healthy gender, age, and body mass index-matched individuals were tested. Individuals with contralateral limb injury or abnormality, cardiovascular disease, neurological impairment, and medical conditions limiting activity were excluded. Collected data included Medical Outcomes Study Short Form-36 mental and physical component scores, the Knee Outcome Survey Activities of Daily Living Scale score, knee range of motion, timed up-and-go test time, stairclimb test time, six-minute walk distance, normalized quadriceps strength, and volitional muscle activation. Results： Women in the arthroplasty group had lower Short Form-36 and Knee Outcome Survey scores, longer timed up-and-go test and stairclimb test times, shorter six-minute walk distances, and lower normalized quadriceps strength compared with men. Healthy women had longer stair-climb test times and shorter six-minute walk distances in comparison with healthy men. Between-group comparisons revealed that women in both the control group and the arthroplasty group had reduced normalized quadriceps strength in comparison with men, that healthy women had higher voluntary muscle activation in comparison with healthy men, and that female arthroplasty candidates had lower activation levels in comparison with male candidates. Conclusions： Observed gender differences in strength and function appear to be inherent but are magnified in arthroplasty candidates. Strength and functional decline should be closely monitored in women with knee osteoarthritis to serve as an indicator of worsening condition, and preoperative interventions should reflect these gender-specific impairments.

Disease-Specific Gender Differences Among Total Knee Arthroplasty Candidates

Women with knee osteoarthritis are less likely to undergo joint replacement despite greater self-reported disability. The primary aim of the present study was to assess gender differences in the type and magnitude of osteoarthritis-related impairment prior to knee arthroplasty. Two hundred and twenty-one knee arthroplasty candidates (ninety-five men and 126 women) and forty-four healthy gender, age, and body mass index-matched individuals were tested. Individuals with contralateral limb injury or abnormality, cardiovascular disease, neurological impairment, and medical conditions limiting activity were excluded. Collected data included Medical Outcomes Study Short Form-36 mental and physical component scores, the Knee Outcome Survey Activities of Daily Living Scale score, knee range of motion, timed up-and-go test time, stair-climb test time, six-minute walk distance, normalized quadriceps strength, and volitional muscle activation. Women in the arthroplasty group had lower Short Form-36 and Knee Outcome Survey scores, longer timed up-and-go test and stair-climb test times, shorter six-minute walk distances, and lower normalized quadriceps strength compared with men. Healthy women had longer stair-climb test times and shorter six-minute walk distances in comparison with healthy men. Between-group comparisons revealed that women in both the control group and the arthroplasty group had reduced normalized quadriceps strength in comparison with men, that healthy women had higher voluntary muscle activation in comparison with healthy men, and that female arthroplasty candidates had lower activation levels in comparison with male candidates. Observed gender differences in strength and function appear to be inherent but are magnified in arthroplasty candidates. Strength and functional decline should be closely monitored in women with knee osteoarthritis to serve as an indicator of worsening condition, and preoperative interventions should reflect these gender-specific impairments.

Rapid Changes in Gustatory Function Induced by Contralateral Nerve Injury and Sodium Depletion

The combination of dietary sodium depletion and unilateral chorda tympani (CT) nerve section decreases sodium taste function in the intact CT nerve. However, functional changes have not been examined prior to day 4 postsectioning, even though degenerative and inflammatory responses are robust during that period. Rats received unilateral CT section and/or dietary sodium depletion, accomplished by 2 injections of furosemide and a sodium-restricted diet, on day 0. Surgical controls received sham nerve sectioning. At days 1, 2, 3, or 4, taste responses were recorded from the intact nerve. Functional changes were rapid and unexpected. At day 1 postsectioning, neural responses from the uninjured CT of both control-fed and sodium-depleted animals were reduced. By day 2, however, normal function was restored in control-fed rats, whereas functional deficits persisted in depleted animals. Sodium depletion alone also induced a transient decrease in sodium responses at days 2-3 after furosemide injection. These results demonstrate that distant neural injury can elicit gustatory plasticity regardless of the dietary environment, but normal responses can be restored. We suggest that neutrophils mediate the initial postinjury deficits in taste function, whereas macrophages promote the recovery of normal function.