Preoperative Hounsfield Units Predict Pedicle Screw Loosening in Osteoporotic Patients Following Short Segment Lumbar Fusion.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: (1) To determine if vertebral HU values obtained from preoperative CT predict postoperative outcomes following 1-3 level lumbar fusion and (2) to investigate whether decreased BMD values determined by HU predict cage subsidence and screw loosening. SUMMARY OF BACKGROUND DATA: In light of suboptimal screening for osteoporosis, vertebral computerized tomography(CT) Hounsfield Units(HU), have been investigated as a surrogate for bone mineral density(BMD). METHODS: In this retrospective study, adult patients who underwent 1-3 level posterior lumbar decompression and fusion(PLDF) or transforaminal lumbar interbody and fusion(TLIF) for degenerative disease between the years 2017-2022 were eligible for inclusion. Demographics and surgical characteristics were collected. Outcomes assessed included 90-day readmissions, 90-day complications, revisions, patient reported outcomes(PROMs), cage subsidence, and screw loosening. Osteoporosis was defined as HU of ≤110 on preoperative CT at L1. RESULTS: We assessed 119 patients with a mean age of 59.1, of whom 80.7% were white and 64.7% were nonsmokers. The majority underwent PLDF(63%) compared to TLIF(37%), with an average of 1.63 levels fused. Osteoporosis was diagnosed in 37.8% of the cohort with a mean HU in the osteoporotic group of 88.4 compared to 169 in non-osteoporotic patients. Although older in age, osteoporotic individuals did not exhibit increased 90-day readmissions, complications, or revisions compared to non-osteoporotic patients. A significant increase in the incidence of screw loosening was noted in the osteoporotic group with no differences observed in subsidence rates. On multivariable linear regression osteoporosis was independently associated with less improvement in visual analog scale(VAS) scores for back pain. CONCLUSIONS: Osteoporosis predicts screw loosening and increased back pain. Clinicians should be advised of the importance of preoperative BMD optimization as part of their surgical planning and the utility of vertebral CT HU as a tool for risk stratification. LEVEL OF EVIDENCE: 3.

Reference Managers.

Reference Managers (RMs) are software applications designed to build web-based libraries to organize, annotate, and reference literature when compiling a research study. With an ever-increasing volume of literature, RMs not only serve to centralize information but also allow seamless in-text citation and 1-click bibliography creation, with the ability to format each citation based on target journal specifications. There are many different RMs available for utilization; some of the most popular are EndNote, Zotero, Mendeley, and Paperpile. Each of these aforementioned applications has its own pros and cons, which this paper aims to summarize, though authors should take their individual research needs into consideration when deciding on their preferred reference manager.

Risk of noise-induced hearing loss in the spine surgeon.

Background: Occupation-related noise-induced hearing loss (NIHL) has both negative economic and quality of life implications. The risk spine surgeons undertake in regards to NIHL during operative intervention is unknown. Governing bodies, including the National Institute for Occupational Safety and Health, have recommended exposure limits not to exceed 85 decibels (dB) over 8 hours. The purpose of this study is to characterize noise exposure to spine surgeons in the operating room (OR). Methods: Prospective collection of intraoperative recordings of spinal surgeries (cervical and thoracic/lumbar) was undertaken. Data gathered included procedure, operative duration, presence of background music, and noise information. Noise information included maximum decibel level (MDL), Peak level (LCPeak), Equivalent continuous sound pressure level, time weighted average (TWA), dose, and projected dose. Noise measurements were compared with baseline controls with and without music (empty ORs). Results: Two hundred seven noise recordings were analyzed. One hundred eighteen of those being spinal surgeries, 49 baseline recordings without music, and 40 with music. Maximum decibel level reached a maximum value of 111.5 dBA, with an average amongst surgical recordings of 103 dBA. Maximum decibel level exceeded 85 dBA in 100% of cases and was greater than 100 dBA in 78%. The maximum LCPeak recorded was 132.9 dBC with an average of 120 dBC. Furthermore, the average dose was 7.8% with an average projected dose of 26.5%. The highest dose occurred during a laminectomy at 72.9% of daily allowable noise. Maximum projected dose yielded 156% during a 3-level anterior cervical discectomy and fusion. Conclusions: Spine surgeons are routinely exposed to damaging noise levels (>85 dBA) during operative intervention. With spine surgeons often performing multiple surgeries a day, the cumulative risk of noise exposure cannot be ignored. The synergistic effects of continuous and impact noise places spine surgeons at risk for the development of occupation-related NIHL.

Early Diet Liberalization After Anterior Lumbar Interbody Fusion Improves Postoperative Recovery.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: The objective of this study was to assess the impact of diet liberalization on short-term outcomes in patients undergoing anterior interbody lumbar fusion (ALIF). METHODS: A retrospective review was performed for patients undergoing ALIF at our tertiary care center institution from 2010 to 2022. Electronic medical records were reviewed for demographics, surgical characteristics, and 90-day postoperative outcomes. RESULTS: We included 515 patients in this study with 102 patients receiving a full diet on the same day as their operation. All other patients had a delay of at least 1 day (average 1.6 days) until a full diet was provided. This group was found to have a higher rate of postoperative ileus (10.2% vs 2.9%) and urinary retention (16.0% vs 3.9%). The readmission rate and percent of patients presenting to the emergency department within 90 days postoperatively were similar. On multivariate regression analysis, same-day, full-diet patients had decreased odds of developing urinary retention (OR = .17) and a shorter length of hospital stay (Estimate: -.99). Immediate full diet had no impact on the development of ileus (OR: .33). CONCLUSIONS: An immediate postoperative full diet following an anterior approach to the lumbar spine was not found to be associated with an increased risk of postoperative ileus in patients deemed appropriate for early diet liberalization. Moreover, an early full diet was found to reduce length of hospitalization and risk of postoperative urinary retention. Reconsideration of postoperative diet protocols may help optimize patient outcomes and recovery.

Evidence-Based Medicine and Observational Studies.

Evidence-based medicine drives medical decision-making in the modern era, which has historically favored randomized control trials. Despite their notoriety, randomized control trials have multiple disadvantages when applied to spinal surgery. Observational studies are popular in spinal surgery literature and are seen in various forms, such as retrospective studies and prospective cohort studies. For researchers, learners, and practicing spine surgeons, this paper describes options for study design when applied to spinal surgery.

Techniques for Improving Electronic Survey Response Rate.

Electronic surveys are readily utilized for the conduction of orthopedic research and are commonly plagued by decreased response rates as compared with more conventional telephone and paper surveys. Given the rise of electronic survey usage and technological implementation into medical research, this paper aims to summarize factors both intrinsic and extrinsic which can increase survey completion in the clinical setting.

Utilization of In-Hospital Orthopaedic Spine Consultations: Evaluating the Impact of Health Care Policy.

Access to specialty and private practice providers has been a divisive policy issue over the last decade, complicated by the conflict between a reduction in government-funded health care reimbursement and the need for health care providers to sustain a financially sound practice. This study evaluates the orthopedic spine consult service at an academic tertiary care center at 2 separate time points over a 5-year period to better understand the impact of decreasing orthopedic reimbursement rates and the increasing prevalence of federally supported medical insurance on the access to specialty care. In total 500 patients in 2017 and 480 patients in 2021 were included for the final analysis. A higher percentage of consults in 2021 came from the emergency department (74.0% versus 60.4%, P < 0.001); however, the emergency department saw fewer spinal cord injuries (11.9% versus 21.4%, P < 0.001), and the spinal cord injuries were less severe (3.1% versus 6.2% Association Impairment Scale A or B, P = 0.034). A smaller percentage of patients in 2021 went on to receive orthopedic spine surgery following consultation (35.2% versus 43.8%, P = 0.007), and those receiving surgery had an operation performed farther out from the initial consultation (4.73 versus 4.09 days, P < 0.001). Additionally, fewer patients with Medicare insurance (23.5% versus 30.8%) and more patients with Medicaid insurance (20.2% versus 12.4%) were seen in 2021 compared with 2017 (P = 0.003). Overall, this study found an increased proportion of Medicaid patients seen by the spine consult service but a decrease in the acuity of consults. Measures to improve access to health insurance under the Affordable Care Act have revealed the complexity of this issue in health care. This study's findings have demonstrated that while more patients did have insurance coverage following the Affordable Care Act, they still face a barrier to accessing outpatient orthopedic spine providers.

Lateral approach to the lumbar spine: The utility of an access surgeon.

Background: Lateral lumbar interbody fusions (LLIFs) utilize a retroperitoneal approach that avoids the intraperitoneal organs and manipulation of the anterior vasculature encountered in anterior approaches to the lumbar spine. The approach was championed by spinal surgeons; however, general/vasculature surgeons may be more comfortable with the approach. Objective: The objective of this study was to compare short-term outcomes following LLIF procedures based on whether a spine surgeon or access surgeon performed the approach. Materials and Methods: We retrospectively identified all one- to two-level LLIFs at a tertiary care center from 2011 to 2021 for degenerative spine disease. Patients were divided into groups based on whether a spine surgeon or general surgeon performed the surgical approach. The electronic medical record was reviewed for hospital readmissions and complication rates. Results: We identified 239 patients; of which 177 had approaches performed by spine surgeons and 62 by general surgeons. The spine surgeon group had fewer levels with posterior instrumentation (1.40 vs. 2.00; P < 0.001) and decompressed (0.94 vs. 1.25, P = 0.046); however, the two groups had a similar amount of two-level LLIFs (29.9% vs. 27.4%, P = 0.831). This spine surgeon approach group was found to have shorter surgeries (281 vs. 328 min, P = 0.002) and shorter hospital stays Length of Stay (LOS) (3.1 vs. 3.6 days, P = 0.019); however, these differences were largely attributed to the shorter posterior fusion construct. On regression analysis, there was no statistical difference in postoperative complication rates whether or not an access surgeon was utilized (P = 0.226). Conclusion: Similar outcomes may be seen regardless of whether a spine or access surgeon performs the approach for an LLIF.

Sagittal alignment in operative degenerative lumbar spondylolisthesis: a scoping review.

Background: The benefit of surgical intervention over conservative treatment for degenerative lumbar spondylolisthesis (DLS) patients with neurologic symptoms is well-established. However, it is currently unclear what breadth of available evidence exists on regional and global sagittal alignment in DLS surgery. As such, the purpose of the current study is to conduct a scoping review to map and synthesize the DLS literature regarding the current radiographic assessment of sagittal spinal alignment in DLS surgery. Methods: A comprehensive search of the MEDLINE, EMBASE and Cochrane databases from January 1971 to January 2023 was performed for all DLS studies examining sagittal spinal alignment parameters with DLS surgery according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review (PRISMA-ScR) protocol. Results: From 2,222 studies, a total of 109 studies were included, representing 10,730 patients with an average age of 63.0 years old and average follow-up of 35.1 months postoperatively. Among included studies, 93 (85%), were largely published in the last decade and predominantly represented retrospective cohorts 70 (64%) or case series 22 (20%). A common theme among the reporting of radiographic parameters in the included investigations was the assessment of the magnitude and/or maintenance of a radiographic change postoperatively, with 92 (84%) studies reporting these findings. The majority of studies focused on index DLS level [33 (30%) studies] or lumbar spine radiographic imaging [33 (30%) studies] only. Thirty-seven (34%) studies reported spinopelvic parameters, with only 13 (12%) of included studies assessing 36-inch standing lateral radiographs and overall alignment. Conclusions: There is increasing prevalence of investigations assessing sagittal spinal alignment parameters in DLS surgery. Although, there is an increasing prevalence of studies investigating sagittal spinal alignment parameters in DLS surgery the quality of the currently available literature on this topic is of overall low evidence and largely retrospective in nature. Additionally, there is limited analysis of global sagittal spinal alignment in DLS suggesting that future investigational emphasis should prioritize longitudinally followed large prospective cohorts or multi-centre randomized controlled trials. Attempts at standardizing the radiographic and functional outcome reporting techniques across multi-centre investigations and prospective cohorts will allow for more robust, reproducible analyses of significance to be conducted on DLS patients.

The Impact of Unexpected Billing in Spine Surgery and How the Price Calculator Can Improve Patient Care.

STUDY DESIGN: Survey study. OBJECTIVE: The objective of this study was to determine the impact of unexpected in-network billing on the patient experience after spinal surgery. SUMMARY OF BACKGROUND DATA: The average American household faces difficulty paying unexpected medical bills. Although legislative efforts have targeted price transparency and rising costs, elective surgical costs continue to rise significantly. Patients are therefore sometimes still responsible for unexpected medical costs, the impact of which is unknown in spine surgery. METHODS: Patients who underwent elective spine surgery patients from January 2021 to January 2022 at a single institution were surveyed regarding their experience with the billing process. Demographic characteristics associated with unexpected billing situations, patient satisfaction, and financial distress, along with utilization and evaluation of the online price estimator, were collected. RESULTS: Of 818 survey participants, 183 (22.4%) received an unexpected in-network bill, and these patients were younger (56.7 vs. 63.4 y, P <0.001). Patients who received an unexpected bill were more likely to feel uninformed about billing (41.2% vs. 21.7%, P <0.001) and to report that billing impacted surgical satisfaction (53.8% vs. 19.1%, P <0.001). However, both groups reported similar satisfaction postoperatively (Likert >3/5: 86.0% vs. 85.5%, P =0.856). Only 35 (4.3%) patients knew of the price estimator's existence. The price estimator was reported to be very easy or easy (N=18, 78.2%) to understand and very accurate (N=6, 35.3%) or somewhat accurate (N=8, 47.1%) in predicting costs. CONCLUSIONS: Despite new regulations, a significant portion of patients received unexpected bills leading to financial distress and affecting their surgical experience. Although most patients were unaware of the price estimator, almost all patients who did know of it found it to be easy to use and accurate in cost prediction. Patients may benefit from targeted education efforts, including information on the price estimator to alleviate unexpected financial burden.

Patients With Low Resilience Scores Have Significantly Worse Postoperative Outcomes After Anterior Cruciate Ligament Reconstruction Than Patients With Normal or High Resilience Scores.

Purpose: To evaluate the relationship between patient resilience and patient-reported outcome measures (PROMS) after primary anterior cruciate ligament (ACL) reconstruction. Methods: Patients who underwent an ACL reconstruction by a single surgeon between January 2012 and June 2020 were identified by an institutional query using Current Procedural Terminology codes. Patients were included if they (1) underwent a primary ACL reconstruction and (2) had a minimum of 2 years' follow-up. Data were retrospectively collected regarding demographics, surgical details, visual analog scale (VAS) scores, and 12-item short form survey (SF-12) scores. Resilience scores were obtained via the Brief Resilience Scale questionnaire. Stratification into low (LR), normal (NR), and high resilience (HR) was based on standard deviation from mean Brief Resilience Scale score to determine differences in PROMS between groups. Results: One-hundred eighty-seven patients were identified by the institutional query. Of the 187 patients, 180 met inclusion criteria. Seven patients underwent revision ACL reconstruction and were excluded from the study. One-hundred three patients (57.2%) completed the postoperative questionnaire and were included. Patients in the NR group and HR group had significantly greater postoperative SF-12 scores (P < .001) and lower postoperative VAS pain scores (P < .001) when compared with those of the LR group. This trend was again shown with breakdown of the SF-12 into physical and mental aspects, each of which were significantly greater in either the NR group or HR group when compared with the LR group (P < .001). Overall, 97.9% and 99.0% of patients had changes in their SF-12 total and VAS pain scores respectively that exceeded the minimal clinically important difference for the cohort. Conclusions: Patients with lower resilience scores have worse PROMs and increased pain than patients with greater resilience at a minimum of 2-year follow-up after ACL reconstruction. Level of Evidence: Level IV, prognostic case series.

The Effect of Preoperative Exposure to Benzodiazepines on Opioid Consumption After One and Two-level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Investigate the relationship between preoperative benzodiazepine exposure and postoperative opioid use in patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion (ACDF). BACKGROUND: Little is known about the effect of preoperative benzodiazepine exposure on postoperative opioid use in spine surgery. PATIENTS AND METHODS: Patients undergoing primary 1 or 2-level ACDF at a single institution from February 2020 to November 2021 were identified through electronic medical records. The prescription drug monitoring program was utilized to record the name, dosage, and quantity of preoperative benzodiazepines/opioids filled within 60 days before surgery and postoperative opioids 6 months after surgery. Patients were classified as benzodiazepine naïve or exposed according to preoperative usage, and postoperative opioid dose and duration were compared between groups. Regression analysis was performed for outcomes that demonstrated statistical significance, adjusting for preoperative opioid use, age, sex, and body mass index. RESULTS: Sixty-seven patients comprised the benzodiazepine-exposed group whereas 90 comprised the benzodiazepine-naïve group. There was no significant difference in average daily morphine milligram equivalents between groups (median: 96.0 vs 65.0, P = 0.11). The benzodiazepine-exposed group received postoperative opioids for a longer duration (median: 32.0 d vs 12.0 d, P = 0.004) with more prescriptions (median: 2.0 vs 1.0, P = 0.004) and a greater number of pills (median: 110.0 vs 59.0, P = 0.007). On regression analysis, preoperative benzodiazepine use was not significantly associated with postoperative opioid duration [incidence rate ratio (IRR): 0.93, P = 0.74], number of prescriptions (IRR: 1.21, P = 0.16), or number of pills (IRR: 0.89, P = 0.58). CONCLUSIONS: While preoperative benzodiazepine users undergoing primary 1 or 2-level ACDF received postoperative opioids for a longer duration compared with a benzodiazepine naïve cohort, preoperative benzodiazepine use did not independently contribute to this observation. These findings provide insight into the relationship between preoperative benzodiazepine use and postoperative opioid consumption. LEVEL OF EVIDENCE: Level III.

Associating Outcomes After Hip Arthroscopy With Patient Resilience.

Background: Higher patient resilience has been shown to be associated with improved patient-reported outcome measures (PROMs) at 6 months after hip arthroscopy. Purpose: To examine the relationship between patient resilience and PROMs at minimum 2 years after hip arthroscopy. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were 89 patients (mean age, 36.9 years; mean follow-up, 4.6 years). Patient demographics, surgical details, and preoperative International Hip Outcome Tool-12 (iHOT-12) and visual analog scale (VAS) pain scores were collected retrospectively. Postoperative variables were collected via a survey and included the Brief Resilience Scale (BRS), Patient Activation Measure-13 (PAM-13), Pain Self-efficacy Questionnaire-2 (PSEQ-2), VAS satisfaction, and postoperative iHOT-12, and VAS pain scores. Based on the number of standard deviations from the mean BRS score, patients were stratified as having low resilience (LR; n = 18), normal resilience (NR; n = 48), and high resilience (HR; n = 23). Differences in PROMs were compared between the groups, and a multivariate regression analysis was performed to assess the relationship between pre- to postoperative change (Δ) in PROMs and patient resilience. Results: There were significantly more smokers in the LR group compared with the NR and HR groups (P = .033). Compared with the NR and HR groups, patients in the LR group had significantly more labral repairs (P = .006), significantly worse postoperative iHOT-12, VAS pain, VAS satisfaction, PAM-13, and PSEQ-2 scores (P < .001 for all), and significantly lower ΔVAS pain and ΔiHOT-12 scores (P = .01 and .032, respectively). Regression analysis showed significant associations between ΔVAS pain and NR (ß = -22.50 [95% CI, -38.81 to -6.19]; P = .008) as well as HR (ß = -28.31 [95% CI, -46.96 to -9.67; P = .004) and between ΔiHOT-12 and NR (ß = 18.94 [95% CI, 6.33 to 31.55]; P = .004) as well as HR (ß = 20.63 [95% CI, 6.21 to 35.05]; P = .006). Male sex was a significant predictor of ΔiHOT-12 (ß = -15.05 [95% CI, -25.42 to -4.69]; P = .006). Conclusion: The study results indicate that lower postoperative resilience scores were associated with significantly worse PROM scores, including pain and satisfaction, at 2 years after hip arthroscopy.

A Scoping Review of Injuries in Amateur and Professional Men's Ice Hockey.

Background: Orthopaedic injuries are common in ice hockey at all levels and can result in physical and psychological adverse effects on these athletes. Purpose: Primarily, to summarize published data on orthopaedic hockey injuries at the junior through professional level. Secondarily, to characterize the literature based on anatomic site injured, return-to-play rates, cause/mechanism of injury, time lost, and treatments used. Study Design: Scoping review; Level of evidence, 4. Methods: PubMed, EMBASE, Cochrane library, and SCOPUS were searched using the terms "hockey" and "injuries" using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and 4163 studies involving orthopaedic injuries were identified. Our inclusion criteria consisted of accessible full-text articles that evaluated orthopaedic injuries in men's ice hockey athletes of all levels. We excluded case reports and articles evaluating women's ice hockey injuries, as well as those evaluating nonorthopaedic injuries, such as concussions; traumatic brain injuries; and facial, dental, and vascular injuries, among others. Studies were divided based on level of play and anatomic site of injury. Level of evidence, year published, country of corresponding author, method of data collection, incidence of injury per athlete-exposure, and time lost were extracted from each article. Results: A total of 92 articles met the inclusion criteria and were performed between 1975 and 2020, with the majority published between 2015 and 2020. These were divided into 8 anatomic sites: nonanatomic-specific (37%), intra-articular hip (20.7%), shoulder (9.8%), knee (8.7%), trunk/pelvis (7.6%), spine (7.6%), foot/ankle (6.5%), and hand/wrist (2.2%). Of these studies, 71% were level 4 evidence. Data were obtained mostly via surveillance programs and searches of publicly available information (eg, injury reports, player profiles, and press releases). Conclusion: This scoping review provides men's hockey players and physicians taking care of elite ice hockey athletes of all levels with a single source of the most current literature regarding orthopaedic injuries. Most research focused on nonanatomic-specific injuries, intra-articular hip injuries, knee injuries, and shoulder injuries, with the majority having level 4 evidence.

Does the Surgical Correction of Tibial Torsion with Genu Varum Produce Outcomes Similar to Those in Varus Correction Alone?

The aim of this article is to study the relationship between tibia vara and external tibial torsion in adults. The following questions were asked: (1) what is the incidence of rotational deformity in patients with genu varum and (2) do patients who undergo correction of tibial torsion with genu varum have similar outcomes to those who undergo simple tibia vara correction? In this study, 69 patients (138 limbs) underwent bilateral proximal tibial osteotomy for the correction of genu varum. Patients with simple coronal plane deformity (varus alone) were treated with either a monolateral external fixator or a hexapod frame. Those with concomitant external tibial torsion were treated with circular external fixation. The primary outcome was the ability to achieve the desired correction of alignment in the coronal, sagittal, and axial planes. Secondary outcomes included a postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) and a routine patient satisfaction questionnaire. The incidence of tibial torsion among the entire group of patients with bilateral tibia vara was 46% and overwhelmingly external in direction. The two groups had some significant differences in demographics with torsion patients tending to be younger and thinner. The final mechanical axis deviation and medial proximal tibial angle values for both groups did not differ significantly (p = 0.956). The postcorrection thigh-foot axis was not significantly different between the two groups (p = 0.666). Time to union was not significant (p > 0.999). KOOS was not different between the two groups in symptoms, pain, activities of daily living, and return to sport. There was a difference in the quality of life score between the two groups (p = 0.044). There was no difference between the two groups regarding the patient questionnaire. Based on the finding of this analysis, the incidence of rotational malalignment with genu varum is close to 50%. The recognition of this close association with external tibial torsion deformity may allow for further insights into the role of rotation in varus deformity-related knee pathology and treatment. Patients can expect nearly identical outcomes from this surgery.

First Reported Case of Hemopericardium Related to Dabigatran Use Reversed by New Antidote Idarucizumab.

Dabigatran, the first novel oral anticoagulant (NOAC) with a reversal agent, heralded a paradigm shift in the treatment of nonvalvular atrial fibrillation. The potential for life-threatening hemorrhagic events with the use of NOACs has been highly debated since the effectiveness of reversal agents such as idarucizumab is based primarily on pharmacologic data. It is known that cancer patients are at an increased risk of bleeding with anticoagulation, though specific studies demonstrating the risks or efficacy of NOACs in this population are lacking. We provide the first report of hemopericardium resulting in multiorgan failure related to dabigatran use that was successfully reversed by idarucizumab in a man with prostate cancer on chemotherapy.