High Rate of Concomitant Lumbo-Sacral Spine Pathology in the Setting of Hip Abductor Tendon Repair.

BACKGROUND: Hip abductor deficiency is a common cause of lateral hip pain in middle-aged patients. Identifying upstream muscle denervation originating in the lumbo-sacral spine could potentially impact the management of patients who have abductor deficiency. The purpose of this study was to estimate the prevalence of lumbo-sacral pathology (L4 to S1) in patients undergoing hip abductor tendon repair. METHODS: All cases of primary hip abductor repair performed at a tertiary care center between January 2010 and December 2021 were reviewed. Patients were classified into the following groups: A) Confirmed L4 to S1 disease based on preoperative or perioperative L4 to S1 interventions (i.e., surgery, epidural injections, and/or positive electromyography findings); B) Radiographic evidence on lumbar spine magnetic resonance imaging (MRI) demonstrating nerve compression at L4 to S1; and C) No evidence of L4 to S1 disease. RESULTS: There were 131 cases of primary hip abductor repair that were included. Over 80% of patients were women, who had a mean age of 64 years (range, 20 to 85). There were thirteen patients (9.9%) who underwent concomitant total hip arthroplasty (THA). Of the included patients, 29% (n = 38) were categorized into group A, 12% (n = 16) into group B, and 59% (n = 77) into group C. Patients who had L4 to S1 pathology were older than patients who did not have L4 to S1 pathology (67 versus 61 years, P = 0.004). Of the patients undergoing concomitant THA and hip abductor repair, 54% demonstrated evidence of lumbo-sacral spine pathology. CONCLUSIONS: Over 40% of patients undergoing isolated hip abductor tendon repair and >50% of patients undergoing concomitant hip abductor tendon repair and THA demonstrated evidence of L4 to S1 disease perioperatively. Patients demonstrating symptomatic hip abductor deficiency should be screened for concomitant lower lumbo-sacral spine pathology.

A Consecutive Series of Vancouver B2 Periprosthetic Femur Fractures Treated With Contemporary Monoblock Versus Modular Revision Stems: Clinical and Radiographic Outcomes.

BACKGROUND: Tapered fluted titanium (TFT) stems are the implant design of choice for managing Vancouver B2 periprosthetic femur fractures (PFFs), producing reliable results over the past few decades. The aim of this study was to compare the radiographic and clinical outcomes of Vancouver B2 PFFs treated with contemporary monoblock versus modular TFTs. METHODS: A consecutive series of 113 patients (72 women, 64%, mean age 70 years [range, 26 to 96]) who had a B2 PFF were treated with either a monoblock (n = 42) or modular (n = 71) TFT stem between 2008 and 2021. The mean body mass index was 30 ± 7. The mean follow-up was 2.9 years. A radiographic review was performed to assess leg length and offset restoration, endosteal cortical contact length, and stem subsidence. Kaplan-Meier analyses were used to determine survivorship without revision, reoperation, or dislocation. RESULTS: There was no difference in the restoration of leg length (0.3 ± 8.0 mm) or offset (2.8 ± 8.2 mm) between the monoblock and modular cohorts (P > .05). Mean endosteal cortical contact length (47.2 ± 26.6 versus 46.7 ± 2 6.4 mm, P = .89) and stem subsidence (2.7 ± 3.5 versus 2.4 ± 3.2 mm, P = .66) did not differ. No difference in patient-reported outcome measures (Hip Disability and Osteoarthritis Outcome Score-Joint Replacement; Veterans RAND 12 Item Health Survey Physical and Mental; visual analog score; and Lower Extremity Activity Scale) between the groups was observed. Survivorship at 2 years free from reoperation, revision, and dislocation was 90.4, 90.3, and 97.6%, respectively, for the monoblock cohort; and 84.0, 86.9, and 90.0%, respectively, for the modular cohort. CONCLUSIONS: No significant differences in radiographic or clinical outcomes were observed between patients treated with monoblock or modular TFTs in this large series of B2 PFFs.

A Comparison of Clinical Outcomes After Total Knee Arthroplasty in Patients Who Have and Do Not Have Self-Reported Nickel Allergy: Matched and Unmatched Cohort Comparisons.

BACKGROUND: The impact of a preoperative self-reported nickel allergy in patients undergoing primary total knee arthroplasty (TKA) remains unclear. The aim of this study was to compare the revision rates and outcomes of patients who have a self-reported nickel allergy undergoing primary TKA to patients who do not have a self-reported nickel allergy. METHODS: Over 5 years, a total of 284 TKAs in patients who have and 17,735 in patients who do not have a self-reported nickel allergy were performed. Revision rates and differences in preoperative and postoperative patient-reported outcome measures, including Knee Osteoarthritis Outcome Score Joint Replacement (KOOS JR), Visual Analog Scale, Lower Extremity Activity Scale, and the Patient-Reported Outcomes Measurement Information System Mental and Physical Scores, were compared. RESULTS: Survivorship free of all-cause revision at 1 year was similar for patients who have and do not have a self-reported nickel allergy (99.5% [95% CI (confidence interval): 98.6 to 100.0] versus 99.3% [95% CI: 99.1 to 99.4]), P = .49). Patients who have a self-reported nickel allergy undergoing primary TKA had no difference in KOOS JR, Visual Analog Scale, or Lower Extremity Activity Scale scores at 6 weeks and 1 year and slightly worse Patient-Reported Outcomes Measurement Information System mental and physical scores at 6 weeks compared to patients who did not have an allergy. Matched analysis revealed no difference in 6-week or 1-year KOOS, JR scores between patients who did and did not have a self-reported nickel allergy when stratified by implant class (nickel-free versus standard cobalt-chromium) (P = .113 and P = .415, respectively). CONCLUSIONS: Patients who have a self-reported nickel allergy can be advised that, on average, their clinical outcome scores will improve similarly to patients who do not have a self-reported nickel allergy, and revision rates will be similar.

A Comparison of Clinical Outcomes After Total Knee Arthroplasty in Patients With Preoperative Nickel Allergy Receiving Cobalt Chromium or Nickel-Free Implant.

BACKGROUND: The role of metal hypersensitivity reactions in total knee arthroplasty (TKA) failure is debated. There is no consensus on whether use of a more expensive nickel-free implant is indicated for patients who have preoperative nickel allergy. The purpose of this study was to examine the outcome of patients who have preoperative nickel allergy receiving nickel-free or cobalt chromium (CoCr) implants. METHODS: This was a retrospective review of 17,798 patients who underwent 20,324 unilateral primary TKAs between 2016 and 2020. Presence of preoperative nickel allergy was determined (n = 282). Patients were divided into 2 cohorts: those receiving (1) nickel-free or (2) CoCr implants. Clinical outcome scores and revision rates were assessed. RESULTS: 243 received a nickel-free implant and 39 received a CoCr implant. There was no significant difference in revision rate between the cohorts. Survivorship free of revision was 94% in the CoCr implant cohort and 98% in the nickel-free implant cohort (P = .9). When comparing clinical outcome scores between cohorts, there was no difference in preoperative, 6-week or 1-year Knee Osteoarthritis Outcome Score Joint Replacement, Visual Analog Scale (VAS), Lower Extremity Activity Scale, Patient-Reported Outcomes Measurement Information System (PROMIS), and Veterans RAND 12-item scores between cohorts. CONCLUSION: In this retrospective cohort study, there was no difference in revision rates or clinical outcomes in patients who had a nickel allergy undergoing primary TKA with CoCr or nickel-free implants. Further studies are needed to determine if nickel allergy is an independent risk factor for worse TKA outcomes in general.

Intraoperative Neurological Monitoring in Lower Limb Surgery for Patients With Mucopolysaccharidoses.

BACKGROUND: There are reports of spinal cord injury (SCI) occurring after lower extremity (LE) surgery in children with mucopolysaccharidoses (MPS). Intraoperative neurological monitoring (IONM) has been adopted in some centers to assess real-time spinal cord function during these procedures. The aim of this investigation was to review 3 specialty centers' experiences with MPS patients undergoing LE surgery. We report how IONM affected care and the details of spinal cord injuries in these patients. METHODS: All pediatric MPS patients who underwent LE surgery between 2001 and 2018 were reviewed at 3 children's orthopaedic specialty centers. Demographic and surgical details were reviewed. Estimated blood loss (EBL), surgical time, positioning, use of IONM, and changes in management as a result of IONM were recorded. Details of any spinal cord injuries were examined in detail. RESULTS: During the study period, 92 patients with MPS underwent 252 LE surgeries. IONM was used in 83 of 252 (32.9%) surgeries, and intraoperative care was altered in 17 of 83 (20.5%) cases, including serial repositioning (n=7), aggressive blood pressure management (n=6), and abortion of procedures (n=8). IONM was utilized in cases with larger EBL (279 vs. 130 mL) and longer operative time (274 vs. 175 min) compared with procedures without IONM. Three patients without IONM sustained complete thoracic SCI postoperatively, all from cord infarction in the upper thoracic region. These 3 cases were characterized by long surgical time (328±41 min) and substantial EBL (533±416 mL or 30.5% of total blood volume; range, 11% to 50%). No LE surgeries accompanied by IONM experienced SCI. CONCLUSIONS: Patients with MPS undergoing LE orthopaedic surgery may be at risk for SCI, particularly if the procedures are long or are expected to have large EBL. One hypothesis for the etiology of SCI in this setting is hypoperfusion of the upper thoracic spinal cord due to prolonged intraoperative or postoperative hypotension. IONM during these procedures may mitigate the risk of SCI by identifying real-time changes in spinal cord function during surgery, inciting a change in the surgical plan. LEVEL OF EVIDENCE: Level III-retrospective comparative series.

What Proportion of Orthopaedic Surgery Residency Programs Have Accessible Parental Leave Policies, and How Generous are They?

BACKGROUND: Parental leave during graduate medical education is a component of wellness in the workplace. Although every graduate medical education program is required by the Accreditation Council for Graduate Medical Education (ACGME) to have a leave policy, individual programs can create their own policies. The ACGME stipulates that "the sponsoring institution must provide a written policy on resident vacation and other leaves of absence (with or without pay) to include parental and sick leave to all applicants." To our knowledge, a review of parental leave policies of all orthopaedic surgery residency programs has not been performed. QUESTION/PURPOSES: (1) What proportion of orthopaedic surgery residency programs have accessible parental (maternity, paternity, and adoption) leave policies? (2) If a policy exists, what financial support is provided and what allotment of time is allowed? METHODS: All ACGME-accredited orthopaedic surgery residency programs in 2017 and 2018 were identified. One hundred sixty-six ACGME-accredited allopathic orthopaedic surgery residency programs were identified and reviewed by two observers. Reviewers determined if a program had written parental leave policy, including maternity, paternity, or adoption leave. Ten percent of programs were contacted to verify reviewer findings. The search was sequentially conducted starting with the orthopaedic surgery residency program's website. If the information was not found, the graduate medical education (GME) website was searched. If the information was not found on either website, the program was contacted directly via email and phone. Parental leave policies were classified as to whether they provided dedicated parental leave pay, provided sick leave pay, or deferred to unpaid Family Medical Leave Act (FMLA) policies. The number of weeks of maternity, paternity, and adoption leave allowed was collected. RESULTS: Our results showed that 3% (5 of 166) of orthopaedic surgery residency programs had a clearly stated policy on their program website. Overall, 81% (134 of 166) had policy information on the institution's GME website; 7% (12 of 166) of programs required direct communication with program coordinators to obtain policy information. Further, 9% (15 of 166) of programs were deemed to not have an available written policy as mandated by the ACGME. A total of 21% of programs (35 of 166) offered designated parental leave pay, 29% (48 of 166) compensated through sick leave pay, and 50% (83 of166) deferred to federal law (FMLA) requiring up to 12 weeks of unpaid leave. CONCLUSIONS: Although 91% of programs meet the ACGME requirement of written parental leave policies, current parental leave policies in orthopaedic surgery are not easily accessible for prospective residents, and they do not provide clear compensation and length of leave information. Only 3% (5 of 166) of orthopaedic surgery residency programs had a clearly stated leave policy accessible on the program's website. Substantial improvements would be gained if every orthopaedic residency program clearly outlined the parental leave policy on their residency program website, including compensation and length of leave, particularly in light of the 2019 American Board of Orthopaedic Surgery changes allowing time away to be averaged over the 5 years of training. CLINICAL RELEVANCE: Parental leave policies are increasingly relevant to today's trainees []. Applicants to orthopaedic surgery today value work/life balance including protected parental leave [].

Clinical Outcomes of Explosion Injuries to the Hand.

PURPOSE: The purpose of this study is to report clinical outcomes in a cohort of 12 patients with explosion injuries to the hand. METHODS: Twelve male patients with a mean age of 42.4 years (SD, 7.2) were examined at a mean of 54 months after sustaining explosion injuries to the hand. All patients underwent primary reconstruction and early soft tissue coverage within 72 hours after their injuries. Total active range of motion and moving 2-point discrimination in each digit were recorded along with hand injury severity score (HISS), disability of the arm, shoulder, and hand (DASH) score, and American Medical Association (AMA) impairment ratings. RESULTS: For digits saved, the average total active motion at final follow-up was 215 degrees (SD, 66.5). Twenty-two digits had 6-mm 2-point discrimination, and 17 digits had 8- to 10-mm 2-point discrimination. Eight of the 12 patients had secondary procedures. We found a strong correlation between initial HISS and DASH scores at final follow-up. There was also a strong correlation between AMA impairment rating and DASH scores. CONCLUSIONS: Early reconstruction provides protective sensation and preserves some function after explosion injuries. Preoperative HISS correlates with the long-term functional outcome as measured by DASH scores. For this group of patients, postinjury AMA impairment ratings also correlate with functional outcomes for the upper extremity.

Digital artery flow hemodynamics: An ultrasonographic study.

BACKGROUND: There is a lack of data regarding the baseline hemodynamic blood flow parameters of the wrist and digits. Therefore, we aimed to quantify the digital and radial artery blood flow parameters using ultrasound and assess the influence of patient characteristics on hemodynamics. METHODS: We analyzed ultrasonographic data from 25 patients (50 hands) between October 2019 and December 2021. Variables of interest included dimensions of the radial artery and index finger (IF) ulnar and radial digital arteries at the palmodigital crease and their corresponding flow parameters. We compared variables among men and women and patients with and without diabetes using Wilcoxon Rank Sum test. RESULTS: Our cohort consisted of 18 women (36 hands) and three participants with diabetes (six hands). The mean diameter of the IF radial digital artery was 7 mm, and that of the ulnar digital artery was 10 mm. The average peak systolic velocity for the radial digital artery was 21.31 cm/sec, and for the ulnar digital artery, it was 30.03 cm/sec. Comparing men and women, the only significant difference found was in the time-averaged mean velocity for the ulnar digital artery (men:5.66 cm/sec vs. women:9.68 cm/sec, P = 0.02) and volume of flow for the ulnar digital artery (men:10.87cc/min vs. women:18.58cc/min, P = 0.03). We found no differences in blood flow parameters comparing participants with and without diabetes. CONCLUSION: These data provide a baseline measurement of digital flow hemodynamics that can be used in future studies to model vascular flow after replantation.

Projected Savings Associated with Lowering the Risk of Total Hip Arthroplasty Revision Due to Dislocation in Patients with Spinopelvic Pathology.

Purpose: In the United States (US), total hip arthroplasty (THA) is the most common hospital inpatient operation among Medicare beneficiaries and is ranked fourth when considering all payers. Spinopelvic pathology (SPP) is associated with an increased risk of THA revision (rTHA) due to dislocation. Several strategies have been proposed to mitigate the risk of instability in this population, including use of dual-mobility implants, anterior-based surgical approaches, and technology-assistance (digital 2D/3D pre-surgical planning, computer navigation, and robotic assistance). For primary THA (pTHA) patients with SPP who subsequently undergo rTHA due to dislocation, we aimed to estimate (1) target population size; (2) economic burden; and (3) 10-year projected savings to the US payer of lowering the risk of rTHA due to dislocation among pTHA patients with SPP. Methods: A budget impact analysis from the US payer perspective was undertaken using published literature; American Academy of Orthopaedic Surgeons American Joint Replacement Registry 2021 Annual Report; Centers for Medicare & Medicaid Services MEDPAR 2019; and National (Nationwide) Inpatient Sample (NIS) 2019. Expenditures were inflation-adjusted to 2021 US dollars using the Medical Care component of the Consumer Price Index. Sensitivity analyses were performed. Results: The target population size in 2021 was estimated at 5040 (range, 4830-6309) for Medicare (fee-for-service plus Medicare Advantage) and 8003 (range, 7669-10,018) for all-payer. Annual rTHA episode-of-care (through 90 days) expenditures for Medicare and all-payer were $185 million and $314 million, respectively. Using a 4.14% compound annual growth rate from NIS, the estimated number of applicable rTHA procedures that will be performed from 2022-2031 was 63,419 Medicare and 100,697 all-payer. With each 10% reduction in relative risk of rTHA due to dislocation, Medicare and all-payer could save $233 million and $395 million, respectively, over a 10-year period. Conclusion: Among pTHA patients with spinopelvic pathology, a modest reduction in the risk of rTHA due to dislocation could achieve substantial cumulative savings to payers while improving healthcare quality.

A Review of the Lateral Patellofemoral Joint: Anatomy, Biomechanics, and Surgical Procedures.

The lateral patellofemoral joint soft tissues contain key structures that surround and balance the joint. These structures can affect joint tracking, stability, and force distribution. It is important to understand the lateral patellofemoral anatomy and biomechanics, and their relationship with patellofemoral instability, anterior knee pain, and osteoarthritis. Lateral-sided surgical procedures such as lateral release, lateral retinacular lengthening, and partial lateral patellar facetectomy can be useful in the treatment of such patellofemoral problems.

Cost Reduction for Knee-Spanning External Fixation in the Staged Treatment of Tibial Plateau Fractures: A Practical Intervention.

OBJECTIVE: To determine whether an educational intervention affects surgeon implant decision making measured by total implant costs for temporizing a knee-spanning external fixation construct. DESIGN: A total of 24 cases were prospectively collected after an educational intervention and matched to 24 cases before intervention using Schatzker classification and by surgeon. SETTING: A single Level 1 trauma center. PATIENTS/PARTICIPANTS: Forty-eight patients with Schatzker II-VI tibial plateau fractures. INTERVENTION: Education session to create transparency with component pricing and to provide 3 clinical cases of Orthopaedic Trauma Association/AO 41-C3 (Schatzker VI) with accompanying images and fixator construct costs. Total implant costs displayed in the session ranged from $2354 to $11,696. OUTCOME MEASUREMENT: External fixator construct cost. RESULTS: The mean cost of constructs in the postintervention group was $4550.20 [95% confidence interval (CI) $3945.60-$5154.00], which was significantly different compared with the preintervention group cost of $6046.75 (95% CI = $5309.54-$6783.97, P = 0.003). After 1 year, the total implant costs of external fixation constructs were reduced by an average of almost $1500 per patient. CONCLUSION: An educational intervention created a reduction in the average total implant construction costs for temporary knee-spanning external fixation in the treatment of tibial plateau fractures. Surgical implant selection and cost variance remain an ideal area to improve value for patients and hospitals. Empowering surgeons with knowledge regarding implant prices is a critical part of working toward the cost reductions of external fixation constructs.

Cost and Cost Driver Analysis of Anterior Cruciate Ligament Reconstruction Using Time-Driven Activity-Based Costing: Bone-Tendon-Bone Autograft Versus Hamstring Autograft.

As health care transitions toward value-based care, orthopaedics has started to implement time-driven activity-based costing (TDABC) to understand costs and cost drivers. TDABC has not previously been used to study cost drivers in anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to use TDABC to (1) calculate bone-tendon-bone (BTB) and hamstring ACLR total costs of care and (2) evaluate the impact of graft choice and other factors on ACLR costs. Methods: Data were collected from electronic medical records for primary ACLR from the institutional patient-reported outcome registry between 2009 and 2016 in 1 ambulatory surgery center. Patients receiving allograft, revision ACLR, or concomitant meniscal repair or ligament reconstruction were excluded. The total cost of care was determined using TDABC. Multivariate regression analysis was conducted between ACLR cost and group characteristics. Results: A total of 328 patients were included; 211 (64.3%) received BTB autograft and 117 (35.7%) received hamstring autograft. The mean cost was $2,865.01 ± $263.45 (95% confidence interval: $2,829.26, $2,900.77) for BTB ACLR versus $3,377.44 ± $320.12 ($3,318.82, $3,436.05) for hamstring ACLR (p < 0.001). Operative time was 103.1 ± 25.1 (99.7, 106.5) minutes for BTB ACLR versus 113.1 ± 27.9 (108.0, 118.2) minutes for hamstring ACLR (p = 0.001). The total implant cost was $270.32 ± $97.08 ($257.15, $283.50) for BTB ACLR versus $587.36 ± $108.78 ($567.44, $607.28) for hamstring ACLR (p < 0.001). Hamstring graft (p = 0.006) and suspensory fixation on the femoral side (p = 0.011) were associated with increased costs. Conclusions: The mean cost of care and operative time for BTB autograft ACLR are less than those for hamstring autograft ACLR. Operative time, implant choice, and graft choice were identified as modifiable cost drivers that can empower surgeons to manage primary ACLR costs while maximizing the value of the procedure. Level of Evidence: Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

External Fixation Characteristics Drive Cost of Care for High-Energy Tibial Plateau Fractures.

OBJECTIVE: To determine the total cost for a 30-day episode of care for high-energy tibial plateau fractures and the aspects of care associated with total cost. DESIGN: Time-driven activity-based costing analysis. SETTING: One Level 1 adult trauma center. PATIENTS: One hundred twenty-one patients with isolated, bicondylar tibial plateau fractures undergoing staged treatment were reviewed. PRIMARY OUTCOME: Total cost. RESULTS: A total of 85 patients were included and most sustained Schatzker VI fractures (n = 66, 77%). All patients were treated with biplanar external fixation before definitive fixation. A total of 26 patients (31%) were discharged to skilled nursing facilities, and 37 patients (43%) were not discharged between procedures. Total cost for a 30-day episode of care was $22,113 ± 4056. External fixation components ($5952, 26.9%), length of hospital stay ($5606, 25.4%), discharge to skilled nursing facility (SNF) ($3061, 13.8%), and definitive fixation implants ($2968, 13.4%) contributed to the total cost. The following were associated with total cost: patient discharged to SNFs (P < 0.001), patient remaining inpatient after external fixation (P < 0.001), days of admission for open reduction internal fixation (ORIF) (P = 0.005), days spent with external fixation (P < 0.001), days in a SNF after ORIF (P < 0.001), and external fixation component cost (P < 0.001). CONCLUSIONS: External fixation component selection is the largest contributor to cost of a 30-day episode of care for high-energy bicondylar tibial plateau fractures. Reduction in cost variability may be possible through thoughtful use of external fixation components and care pathways. LEVEL OF EVIDENCE: Economic analyses Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Role of Triangular Fibrocartilage Complex in Axial Stability of the Forearm.

Background The triangular fibrocartilage complex (TFCC) provides stability to the wrist and disruption of this complex can result in axial instability which can lead to ulnocarpal abutment. Purpose This article determines the individual contributions of the volar radioulnar ligament (VRUL), dorsal radioulnar ligament (DRUL), and foveal attachment of the TFCC to longitudinal stability of the forearm under axial load. Materials and Methods Eighteen cadaveric specimens were randomly assigned into three groups representing the component of the TFCC to be initially transected: VRUL, DRUL, and foveal attachment. Prior to transection, posterioranterior radiographs of the wrist were obtained at 0, 44.5, and 90 N of axial load. Serial transection of the TFCC components were performed with radiographs obtained at each of the aforementioned loads. Ulnar variance was assessed with two-way repeated measures analysis of variance and paired t -tests. Results Transection of the foveal attachment demonstrated a significant change in ulnar variance of 1.5 and 0.6 mm under 45 and 90 N of load, respectively. At 0 N of load, there was no significant change in ulnar variance between an intact wrist and a wrist with all three ligaments transected; however, a significant change in ulnar variance, 1.0 mm, was observed under 90 N of load. Conclusion The foveal attachment of the TFCC provides the largest contribution to axial stability. Clinical Relevance The TFCC provides axial stability to the wrist and disruption of the TFCC may result in change in ulnar variance observed on an axial loaded wrist radiograph.

The Effect of Axial Loading on Ulnar Variance.

Background Forearm rotation results in change in ulnar variance. Axial loading of the wrist is required to maintain daily activities. Change in ulnar variance during axial loading has not been investigated previously. Purpose To measure the change in ulnar variance on axially loaded wrists. Patients and Methods We examined 21 asymptomatic individuals and 24 patients with unilateral ulnar-sided wrist pain. All patients underwent standard neutral posteroanterior wrist radiographs without load and under axial loading on bilateral wrists. Axial loading was standardized at 18.1 kgf using an analog weight scale. A magnetic resonance (MR) arthrogram was obtained only in patients with ulnar-sided wrist pain. Beighton flexibility score was recorded on healthy volunteers. Change in ulnar variance between 0 and 18.1 kgf was compared for each wrist among all subjects. A correlation was sought between the change in ulnar variance, MR arthrogram findings, and physical examination. Results In individuals without wrist pain, on average, 0.4 mm increase in ulnar variance was measured between 0 and 18.1 kgf. There was no difference between the dominant and nondominant side. No correlation was found with increasing age. In contrast, patients with ulnar-sided wrist pain displayed an average increase of 0.8 mm in ulnar variance. Compared with the contralateral wrist, more than 1 mm increase in ulnar variance was correlated with intra-articular pathologies including dorsoulnar ligament disruption, central triangular fibrocartilage complex (TFCC) perforation, and foveal detachment. Conclusion Compared with contralateral side, more than 1 mm increase in ulnar variance is suggestive of longitudinal instability or TFCC pathology. Level of Evidence Level II, diagnostic.

Cool Mist Irrigation Improves Heat Dissipation during Surgical Bone Drilling.

Objective High-speed drilling generates heat in small cavities and may pose a risk for neurovascular tissues. We hypothesize that a continuous pressurized cold mist could be an alternative approach for better cooling during drilling of bone to access cranial lesions. This study aims to examine this idea experimentally. Design Ex-vivo drilling tests with controlled speed, feed, and depth were performed on cortical bone samples. Thermocouples were embedded underneath the drilling path to compare the temperature rises under mist cooling (at 3°C, < 300 mL/h) and flood irrigation (at 22°C, > 800 mL/h). Results A significant difference exists between these two systems (p value < 0.05). The measured temperature was ∼ 4°C lower for mist cooling than for flood irrigation, even with less than a third of the flow rate. Conclusion Experimental data indicate the capability of mist cooling to reduce heat generation while simultaneously enabling flow reduction and targeted cooling. An improved field of view in an extremely narrow access corridor may be achieved with this technology.