Healthy older adults generate transverse-plane momenta required for 90° turns while walking during the same phases of gait as used in straight-line gait.

BACKGROUND: Generation and regulation (control) of linear and angular momentum is a challenge during turning while walking which may be exacerbated by age-related changes. In healthy older adults, little is known about how momentum is controlled during turns, especially within each phase of gait. Each phase of gait affords unique mechanical contexts to control momenta and regulate balance. In healthy young adults, we found that the transverse-plane linear and angular momenta generation strategies observed within specific phases of gait during straight-line gait were also used during turns. Therefore, in this study, we investigated whether healthy older adults shared similar momentum control strategies specific to each gait phase during straight-line gait and turns. METHODS: Nine healthy older adults completed straight-line gait and 90° leftward walking turns. We compared the change in transverse-plane whole-body linear and angular momentum across gait phases (left and right single and double support). We also compared the average leftward force and transverse-plane moment across gait phases. RESULTS: We found that leftward linear momentum was generated most during right single support in straight-line gait and leftward turns. However, in contrast to straight-line gait, during leftward turns, average leftward force was applied across gait phases, with left single support generating significantly less leftward average force than other gait phases. Leftward angular momentum generation and average moment were greatest during left double support in both tasks. We observed some within-participant results that diverged from the group statistical findings, illustrating that although they are common, these momenta control strategies are not necessary. CONCLUSIONS: Older adults generated transverse-plane linear and angular momentum during consistent phases of gait during straight-line gait and 90° turns, potentially indicating a shared control strategy. Understanding momentum control within each phase of gait can help design more specific targets in gait and balance training interventions.

ChatGPT: A concise Google alternative for people seeking accurate and comprehensive carpal tunnel syndrome information.

Popular artificial intelligence systems, like ChatGPT, may be used by anyone to generate humanlike answers to questions. This study assessed whether ChatGPT version 3.5 (ChatGPTv3.5) or the first five results from a Google search provide more accurate, complete, and concise answers to the most common questions patients have about carpal tunnel syndrome. Three orthopedic hand surgeons blindly graded the answers using Likert scales to assess accuracy, completeness, and conciseness. ChatGPTv3.5 and the first five Google results provide answers to carpal tunnel syndrome questions that are similar in accuracy and completeness, but ChatGPTv3.5 answers are more concise. ChatGPTv3.5, being freely accessible to the public, is therefore a good resource for patients seeking concise, Google-equivalent answers to specific medical questions regarding carpal tunnel syndrome. ChatGPTv3.5, given its lack of updated sourcing and risk of presenting false information, should not replace frequently updated academic websites as the primary online medical resource for patients.

A case-control study: epigenetic age acceleration in psoriasis.

Psoriasis (PsO) is a chronic inflammatory skin condition, often accompanied by psoriatic arthritis (PsA) and linked to various comorbidities and increased mortality rates. This study aimed to explore the relationship between PsO and accelerated biological aging, specifically focusing on epigenetic DNA methylation clocks. Using a matched case-control design, 20 PsO cases were selected along with age, race, and sex-matched 20 controls without PsO from the Skin Disease Biorepository at Brown Dermatology, Inc, Providence, Rhode Island. Blood samples retrieved from both groups were analyzed for DNA methylation, and epigenetic ages were calculated using DNA methylation clocks, including Horvath, Hannum, Pheno, SkinBlood, and Grim ages. Generalized estimation equations were employed to test the differences in epigenetic and chronological ages between PsO cases and controls, as well as within various subgroups in comparison to their respective controls. There were no statistically significant differences in epigenetic ages between PsO cases and controls. However, notably, PsO cases with PsA demonstrated an accelerated PhenoAge, compared to their matched controls. This study represents a pioneering investigation into the potential link between PsO and epigenetic aging, shedding light on the possibility of accelerated epigenetic aging in PsA, possibly associated with heightened inflammatory burden. These findings emphasize the systemic impact of PsA on the aging process, prompting the need for deeper exploration into autoimmune pathways, inflammation, and epigenetic modifications underlying PsO pathogenesis and aging mechanisms. Larger-scale studies with diverse populations are imperative to discern PsO subgroups experiencing accelerated biological aging and decipher the intricate interplay between PsO, inflammation, and aging pathways.

The multidirectional roles of the anterior oblique ligament and dorsoradial ligament of the thumb carpometacarpal joint.

The multidirectional biomechanics of the thumb carpometacarpal (CMC) joint underlie the remarkable power and precision of the thumb. Because of the unconfined nature of thumb CMC articulation, these biomechanics are largely dictated by ligaments, notably the anterior oblique ligament (AOL) and the dorsoradial ligament (DRL). However, the rotational and translational stabilizing roles of these ligaments remain unclear, as evidenced by the variety of interventions employed to treat altered pathological CMC biomechanics. The purpose of this study was to determine the effects of sectioning the AOL (n = 8) or DRL (n = 8) on thumb CMC joint biomechanics (rotational range-of-motion [ROM] and stiffness, translational ROM) in 26 rotational directions, including internal and external rotation, and in eight translational directions. Using a robotic musculoskeletal simulation system, the first metacarpal of each specimen (n = 16) was rotated and translated with respect to the trapezium to determine biomechanics before and after ligament sectioning. We observed the greatest increase in rotational ROM and decrease in rotational stiffness in flexion directions and internal rotation following DRL transection and in extension directions following AOL transection. The greatest increase in translational ROM was in dorsal and radial directions following DRL transection and in volar directions following AOL transection. These data suggest the AOL and DRL play complementary stabilizing roles, primarily restraining translations in the direction of and rotations away from the ligament insertion sites. These findings may inform future interventions or implant designs for pathological CMC joints.

The passive biomechanics of the thumb carpometacarpal joint: An in vitro study.

The thumb carpometacarpal (CMC) joint facilitates multidirectional motion of the thumb and affords prehensile power and precision. Traditional methods of quantifying thumb CMC kinematics have been largely limited to range-of-motion (ROM) measurements in 4 orthogonal primary directions (flexion, extension, abduction, adduction) due to difficulties in capturing multidirectional thumb motion. However, important functional motions (e.g., opposition) consist of combinations of these primary directions, as well as coupled rotations (internal and external rotation) and translations. Our goal was to present a method of quantifying the multidirectional in vitro biomechanics of the thumb CMC joint in 6 degrees-of-freedom. A robotic musculoskeletal simulation system was used to manipulate CMC joints of 10 healthy specimens according to specimen-specific joint coordinate systems calculated from computed tomography bone models. To determine ROM and stiffness (K), the first metacarpal (MC1) was rotated with respect to the trapezium (TPM) to a terminal torque of 1 Nm in the four primary directions and in 20 combinations of these primary directions. ROM and K were also determined in internal and external rotation. We found multidirectional ROM was greatest and K least in directions oblique to the primary directions. We also found external rotation coupling with adduction-flexion and abduction-extension and internal rotation coupling with abduction-flexion and adduction-extension. Additionally, the translation of the proximal MC1 was predominantly radial during adduction and predominantly ulnar during abduction. The findings of this study aid in understanding thumb CMC joint mechanics and contextualize pathological changes for future treatment improvement.

Statistical Fragility Analysis of Open Reduction Internal Fixation vs Primary Arthrodesis to Treat Lisfranc Injuries: A Systematic Review.

BACKGROUND: There is a lack of consensus in the use of open reduction internal fixation (ORIF) vs primary arthrodesis (PA) in the management of Lisfranc injuries. Statistical fragility represents the number of events needed to flip statistical significance and provides context to interpret P values of outcomes from conflicting studies. The current study evaluates the statistical fragility of existing research with an outcome-specific approach to provide statistical clarity to the ORIF vs PA discussion. We hypothesized that statistical fragility analysis would offer clinically relevant insight when interpreting conflicting outcomes regarding ORIF vs PA management of Lisfranc injuries. METHODS: All comparative studies, RCTs, and case-series investigating ORIF vs PA management of Lisfranc injuries published through October 5, 2023, were identified. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. Fragility index and continuous fragility index were calculated by the number of event reversals needed to alter significance. Outcomes were categorized by clinical relevance, and median FI and CFI were reported. RESULTS: A total of 244 studies were screened. Ten studies and 67 outcomes (44 dichotomous, 23 continuous) were included in the fragility analysis. Of the 10 studies, 4 studies claimed PA to correlate with superior outcomes compared to ORIF with regard to functional scores and return to function outcomes. Of these 4 studies, 3 were statistically robust. Six studies claimed PA and ORIF to have no differences in outcomes, in which only 2 studies were statistically robust. CONCLUSION: The overall research regarding ORIF vs PA is relatively robust compared with other orthopaedic areas of controversy. Although the full statistical context of each article must be considered, studies supporting PA superiority with regard to functional scores and return to function metrics were found to be statistically robust. Outcome-specific analysis revealed moderate fragility in several clinically relevant outcomes such as functional score, return to function, and wound complications.

A novel large animal model of posttraumatic osteoarthritis induced by inflammation with mechanical stability.

OBJECTIVES: Animal models are needed to reliably separate the effects of mechanical joint instability and inflammation on posttraumatic osteoarthritis (PTOA) pathogenesis. We hypothesized that our modified intra-articular drilling (mIAD) procedure induces cartilage damage and synovial changes through increased inflammation without causing changes in gait. METHODS: Twenty-four Yucatan minipigs were randomized into the mIAD (n=12) or sham control group (n=12). mIAD animals had two osseous tunnels drilled into each of the tibia and femur adjacent to the anterior cruciate ligament (ACL) attachment sites on the left hind knee. Surgical and contralateral limbs were harvested 15 weeks post-surgery. Cartilage degeneration was evaluated macroscopically and histologically. Synovial changes were evaluated histologically. Interleukin-1 beta (IL-1ß), nuclear factor kappa B (NF-κB), and tumor necrosis factor alpha (TNF-α) mRNA expression levels in the synovial membrane were measured using quantitative real-time polymerase chain reaction. IL-1ß and NF-κB levels in chondrocytes were assessed using immunohistochemistry. Load asymmetry during gait was recorded by a pressure-sensing walkway system before and after surgery. RESULTS: The mIAD surgical knees demonstrated greater gross and histological cartilage damage than contralateral (P<.01) and sham knees (P<.05). Synovitis was present only in the mIAD surgical knee. Synovial inflammatory marker (IL-1ß, NF-κB, and TNF-α) expression was three times higher in the mIAD surgical knee than the contralateral (P<.05). Chondrocyte IL-1ß and NF-κB levels were highest in the mIAD surgical knee. In general, there were no significant changes in gait. CONCLUSIONS: The mIAD model induced PTOA through inflammation without affecting gait mechanics. This large animal model has significant applications for evaluating the role of inflammation in PTOA and for developing therapies aimed at reducing inflammation following joint injury.

The Effect of Surgical Duration on Complications and Patient Reported Outcomes in Total Hip Replacement as Evaluated Through Multi-Surgeon Pooled FORCE Registry Data from a Tertiary Care Referral Total Joint Center.

BACKGROUND: The relationship between operative times and patient outcomes in total hip arthroplasty (THA) has not been well defined. METHODS: From January 2016 to December 2019, data were prospectively collected for THA patients in the FORCE-TJR registry and hospital EMR of an academic total-joint center. RESULTS: 1,123 patients were included. Operative times ranged from 36 to 366 minutes, with a mean operative time of 111.26+/-31.37 minutes. Unadjusted GLM showed HOOS pain, ADL, and QoL scores differed across operative times, with patients who had operative times between 106 and 120 minutes having significantly lower pain, higher function, and better quality of life at 12 months, especially compared to patients with operative times < 90 minutes. Patients who had operative times between 106 and 120 minutes had significantly better VR-12 PCS and MCS at 12 months. Although statistically significant, differences were small and did not persist after controlling for within-surgeon effects, patient socio-demographics and baseline patient-reported outcomes, suggesting that patient characteristics or within-surgeon effects may play a more significant role in these patient-reported outcomes than operative time. CONCLUSION: This study showed that among THA patients, operative times were significantly associated with patient-reported outcomes at 12 months post-operatively, but is one of many surgeon and patient-related factors with effect on THA outcome.

Long-Term Bilateral Neuromuscular Function and Knee Osteoarthritis after Anterior Cruciate Ligament Reconstruction.

Neuromuscular function is thought to contribute to posttraumatic osteoarthritis (PTOA) risk in anterior cruciate ligament (ACL)-reconstructed (ACLR) patients, but sensitive and easy-to-use tools are needed to discern whether complex muscle activation strategies are beneficial or maladaptive. Using an electromyography (EMG) signal analysis technique coupled with a machine learning approach, we sought to: (1) identify whether ACLR muscle activity patterns differed from those of healthy controls, and (2) explore which combination of patient outcome measures (thigh muscle girth, knee laxity, hop distance, and activity level) predicted the extent of osteoarthritic changes via magnetic resonance imaging (MRI) in ACLR patients. Eleven ACLR patients 10-15 years post-surgery and 12 healthy controls performed a hop activity while lower limb muscle EMG was recorded bilaterally. Osteoarthritis was evaluated based on MRI. ACLR muscle activity patterns were bilaterally symmetrical and differed from those of healthy controls, suggesting the presence of a global adaptation strategy. Smaller ipsilateral thigh muscle girth was the strongest predictor of inferior MRI scores. The ability of our EMG analysis approach to detect meaningful neuromuscular differences that could ultimately be related to thigh muscle girth provides the foundation to further investigate a direct link between muscle activation patterns and PTOA risk.

Treatment of adult deformity surgery by orthopedic and neurological surgeons: trends in treatment, techniques, and costs by specialty.

BACKGROUND CONTEXT: Surgery to correct adult spinal deformity (ASD) is performed by both neurological surgeons and orthopedic surgeons. Despite well-documented high costs and complication rates following ASD surgery, there is a dearth of research investigating trends in treatment according to surgeon subspeciality. PURPOSE: The purpose of this investigation was to perform an analysis of surgical trends, costs and complications of ASD operations by physician specialty using a large, nationwide sample. STUDY DESIGN/SETTING: Retrospective cohort study using an administrative claims database. PATIENT SAMPLE: A total of 12,929 patients were identified with ASD that underwent deformity surgery performed by neurological or orthopedic surgeons. OUTCOME MEASURES: The primary outcome was surgical case volume by surgeon specialty. Secondary outcomes included costs, medical complications, surgical complications, and reoperation rates (30-day, 1-year, 5-year, and total). METHODS: The PearlDiver Mariner database was queried to identify patients who underwent ASD correction from 2010 to 2019. The cohort was stratified to identify patients who were treated by either orthopedic or neurological surgeons. Surgical volume, baseline characteristics, and surgical techniques were examined between cohorts. Multivariable logistic regression was employed to assess the cost, rate of reoperation and complication according to each subspecialty while controlling for number of levels fused, rate of pelvic fixation, age, gender, region and Charlson Comorbidity Index (CCI). Alpha was set to 0.05 and a Bonferroni correction for multiple comparisons was utilized to set the significance threshold at p ≤.000521. RESULTS: A total of 12,929 ASD patients underwent deformity surgery performed by neurological or orthopedic surgeons. Orthopedic surgeons performed most deformity procedures accounting for 64.57% (8,866/12,929) of all ASD operations, while the proportion treated by neurological surgeons increased 44.2% over the decade (2010: 24.39% vs 2019: 35.16%; p<.0005). Neurological surgeons more frequently operated on older patients (60.52 vs 55.18 years, p<.0005) with more medical comorbidities (CCI scores: 2.01 vs 1.47, p<.0005). Neurological surgeons also performed higher rates of arthrodesis between one and six levels (OR: 1.86, p<.0005), three column osteotomies (OR: 1.35, p<.0005) and navigated or robotic procedures (OR: 3.30, p<.0005). Procedures performed by orthopedic surgeons had significantly lower average costs as compared to neurological surgeons (orthopedic surgeons: $17,971.66 vs neurological surgeons: $22,322.64, p=.253). Adjusted logistic regression controlling for number of levels fused, pelvic fixation, age, sex, region, and comorbidities revealed that patients within neurosurgical care had similar odds of complications to orthopaedic surgery. CONCLUSIONS: This investigation of over 12,000 ASD patients demonstrates orthopedic surgeons continue to perform the majority of ASD correction surgery, although neurological surgeons are performing an increasingly larger percentage over time with a 44% increase in the proportion of surgeries performed in the decade. In this cohort, neurological surgeons more frequently operated on older and more comorbid patients, utilizing shorter-segment fixation with greater use of navigation and robotic assistance.

Transcriptomic changes in porcine articular cartilage one year following disruption of the anterior cruciate ligament.

To determine the transcriptomic changes seen in early- to mid-stage posttraumatic osteoarthritis (PTOA) development, 72 Yucatan minipigs underwent transection of the anterior cruciate ligament. Subjects were randomized to no further intervention, ligament reconstruction, or ligament repair, followed by articular cartilage harvesting and RNA-sequencing at three different postoperative timepoints (1, 4, and 52 weeks). Six additional subjects received no ligament transection and provided cartilage tissue to serve as controls. Differential gene expression analysis between post-transection cartilage and healthy cartilage revealed an initial increase in transcriptomic differences at 1 and 4 weeks followed by a stark reduction in transcriptomic differences at 52 weeks. This analysis also showed how different treatments genetically modulate the course of PTOA following ligament disruption. Specific genes (e.g., MMP1, POSTN, IGF1, PTGFR, HK1) were identified as being upregulated in the cartilage of injured subjects across all timepoints regardless of treatment. At the 52-week timepoint, 4 genes (e.g., A4GALT, EFS, NPTXR, ABCA3) that-as far as we know-have yet to be associated with PTOA were identified as being concordantly differentially expressed across all treatment groups when compared to controls. Functional pathway analysis of injured subject cartilage compared to control cartilage revealed overarching patterns of cellular proliferation at 1 week, angiogenesis, ECM interaction, focal adhesion, and cellular migration at 4 weeks, and calcium signaling, immune system activation, GABA signaling, and HIF-1 signaling at 52 weeks.

Gait-phase specific transverse-plane momenta generation during pre-planned and late-cued 90 degree turns while walking.

Turning while walking is ubiquitous and requires linear and angular momenta generation to redirect the body's trajectory and rotate towards the new direction of travel. This study examined strategies that healthy young adults used during each gait phase to generate transverse-plane momenta during pre-planned and late-cued 90° turns. During leftward turns, we expected that momenta would be generated most during the gait phases known to generate leftward linear and angular momenta during straight line gait. We found distinct roles of gait phases towards generating momenta during turns that partially supported our hypotheses. Supporting one hypothesis, the change in transverse-plane angular momentum and average moment were greater during double support with the left foot in front vs. other gait phases. Also, the change in leftward linear momentum and average leftward force were greater during right single support vs. other gait phases during straight-line gait and late-cued turns. However, during pre-planned turns, the average leftward force was not significantly greater during right single support vs. other gait phases. Overall, transverse-plane angular momentum generation during turns is similar to its generation during straight-line gait, suggesting that healthy young adults can leverage momenta control strategies used during straight-line gait during turns.

Dorsal Subluxation of the First Metacarpal During Thumb Flexion is an Indicator of Carpometacarpal Osteoarthritis Progression.

BACKGROUND: Measurable changes in patients with progression of thumb carpometacarpal (CMC) osteoarthritis (OA) include joint space narrowing, osteophyte formation, subluxation, and adjacent-tissue changes. Subluxation, an indication of mechanical instability, is postulated as an early biomechanical indicator of progressing CMC OA. Various radiographic views and hand postures have been proposed to best assess CMC subluxation, but 3D measurements derived from CT images serve as the optimal metric. However, we do not know which thumb pose yields subluxation that most indicates OA progression. QUESTIONS/PURPOSES: Using osteophyte volume as a quantitative measure of OA progression, we asked: (1) Does dorsal subluxation vary by thumb pose, time, and disease severity in patients with thumb CMC OA? (2) In which thumb pose(s) does dorsal subluxation most differentiate patients with stable CMC OA from those with progressing CMC OA? (3) In those poses, what values of dorsal subluxation indicate a high likelihood of CMC OA progression? METHODS: Between 2011 and 2014, 743 patients were seen at our institutions for trapeziometacarpal pain. We considered individuals who were between the ages of 45 and 75 years, had tenderness to palpation or a positive grind test result, and had modified Eaton Stage 0 or 1 radiographic thumb CMC OA as potentially eligible for enrollment. Based on these criteria, 109 patients were eligible. Of the eligible patients, 19 were excluded because of a lack of interest in study participation, and another four were lost before the minimum study follow-up or had incomplete datasets, leaving 86 (43 female patients with a mean age of 53 ± 6 years and 43 male patients with a mean age of 60 ± 7 years) patients for analysis. Twenty-five asymptomatic participants (controls) aged 45 to 75 years were also prospectively recruited to participate in this study. Inclusion criteria for controls included an absence of thumb pain and no evidence of CMC OA during clinical examination. Of the 25 recruited controls, three were lost to follow-up, leaving 22 for analysis (13 female patients with a mean age of 55 ± 7 years and nine male patients with a mean age of 58 ± 9 years). Over the 6-year study period, CT images were acquired of patients and controls in 11 thumb poses: neutral, adduction, abduction, flexion, extension, grasp, jar, pinch, grasp loaded, jar loaded, and pinch loaded. CT images were acquired at enrollment (Year 0) and Years 1.5, 3, 4.5, and 6 for patients and at Years 0 and 6 for controls. From the CT images, bone models of the first metacarpal (MC1) and trapezium were segmented, and coordinate systems were calculated from their CMC articular surfaces. The volar-dorsal location of the MC1 relative to the trapezium was computed and normalized for bone size. Patients were categorized into stable OA and progressing OA subgroups based on trapezial osteophyte volume. MC1 volar-dorsal location was analyzed by thumb pose, time, and disease severity using linear mixed-effects models. Data are reported as the mean and 95% confidence interval. Differences in volar-dorsal location at enrollment and rate of migration during the study were analyzed for each thumb pose by group (control, stable OA, and progressing OA). A receiver operating characteristic curve analysis of MC1 location was used to identify thumb poses that differentiated patients whose OA was stable from those whose OA was progressing. The Youden J statistic was used to determine optimized cutoff values of subluxation from those poses to be tested as indicators of OA progression. Sensitivity, specificity, negative predictive values, and positive predictive values were calculated to assess the performance of pose-specific cutoff values of MC1 locations as indicators of progressing OA. RESULTS: In flexion, the MC1 locations were volar to the joint center in patients with stable OA (mean -6.2% [95% CI -8.8% to -3.6%]) and controls (mean -6.1% [95% CI -8.9% to -3.2%]), while patients with progressing OA exhibited dorsal subluxation (mean 5.0% [95% CI 1.3% to 8.6%]; p < 0.001). The pose associated with the most rapid MC1 dorsal subluxation in the progressing OA group was thumb flexion (mean 3.2% [95% CI 2.5% to 3.9%] increase per year). In contrast, the MC1 migrated dorsally much slower in the stable OA group (p < 0.001), at only a mean of 0.1% (95% CI -0.4% to 0.6%) per year. A cutoff value of 1.5% for the volar MC1 position during flexion at enrollment (C-statistic: 0.70) was a moderate indicator of OA progression, with a high positive predictive value (0.80) but low negative predictive value (0.54). Positive and negative predictive values of subluxation rate in flexion (2.1% per year) were high (0.81 and 0.81, respectively). The metric that most indicated a high likelihood of OA progression (sensitivity 0.96, negative predictive value 0.89) was a dual cutoff that combined the subluxation rate in flexion (2.1% per year) with that of loaded pinch (1.2% per year). CONCLUSION: In the thumb flexion pose, only the progressing OA group exhibited MC1 dorsal subluxation. The MC1 location cutoff value for progression in flexion was 1.5% volar to the trapezium , which suggests that dorsal subluxation of any amount in this pose indicates a high likelihood of thumb CMC OA progression. However, volar MC1 location in flexion alone was not sufficient to rule out progression. The availability of longitudinal data improved our ability to identify patients whose disease will likely remain stable. In patients whose MC1 location during flexion changed < 2.1% per year and whose MC1 location during pinch loading changed < 1.2% per year, the confidence that their disease would remain stable throughout the 6-year study period was very high. These cutoff rates were a lower limit, and any patients whose dorsal subluxation advanced faster than 2% to 1% per year in their respective hand poses, were highly likely to experience progressive disease. CLINICAL RELEVANCE: Our findings suggest that in patients with early signs of CMC OA, nonoperative interventions aimed to reduce further dorsal subluxation or operative treatments that spare the trapezium and limit subluxation may be effective. It remains to be determined whether our subluxation metrics can be rigorously computed from more widely available technologies, such as plain radiography or ultrasound.

Treatment of Osteoporosis With Anabolic Agents and the Risk of Primary Bone Cancers: A Study of 44,728 Patients Treated With Teriparatide and Abaloparatide.

INTRODUCTION: Bone anabolic agents can benefit orthopaedic patients perioperatively and improve outcomes after fragility fractures. However, preliminary animal data raised concern for the potential development of primary bony malignancies after treatment with these medications. METHODS: This investigation examined 44,728 patients older than 50 years who were prescribed teriparatide or abaloparatide and compared them with a matched control group to evaluate risk of primary bone cancer development. Patients younger than 50 years with a history of cancer or other risk factors of bony malignancy were excluded. A separate cohort of 1,241 patients prescribed an anabolic agent with risk factors of primary bone malignancy, along with 6,199 matched control subjects, was created to evaluate the effect of anabolic agents. Cumulative incidence and incidence rate per 100,000 person-years were calculated as were risk ratios and incidence rate ratios. RESULTS: The overall risk of primary bone malignancy development for risk factor-excluded patients in the anabolic agent-exposed group was 0.02%, compared with 0.05% in the nonexposed group. The incidence rate per 100,000 person-years was calculated at 3.61 for the anabolic-exposed patients and 6.46 for control subjects. A risk ratio of 0.47 ( P = 0.03) and incidence rate ratio of 0.56 ( P = 0.052) were observed for the development of primary bone malignancies in patients undergoing treatment with bone anabolic agents. Among high-risk patients, 5.96% of the anabolic-exposed cohort developed primary bone malignancies and 8.13% of nonexposed patients developed primary bone malignancy. The risk ratio was 0.73 ( P = 0.01), and the incidence rate ratio was 0.95 ( P = 0.67). CONCLUSION: Teriparatide and abaloparatide can safely be used for osteoporosis and orthopaedic perioperative management without increased risk of development of primary bone malignancy.

Long-term functional and structural outcome of rotator cuff repair in patients 60 years old or less.

Background: The long-term outcomes of rotator cuff repair (RCR) have not been well studied. The purpose of this study was to evaluate long-term functional and structural outcomes after RCR in younger patients. Methods: A total of 49 patients (34 [69%] male) with a mean age of 51 ± 6 years were evaluated preoperatively, and at short- and long-term follow-ups (minimum 15 years). There were 13 (27%) small, 17 (35%) medium, 14 (29%) large, and 5 (10%) massive tears. 15 (31%) had an acute repair of a traumatic tear. Long-term evaluation included physical examination, plain radiographs, ultrasound, and patient reported outcome measures (PROMs) (visual analog scale pain, Disability of Arm, Shoulder and Hand, Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and Short Form-36). Statistical analysis was performed to determine associations between preoperative and intraoperative factors and long-term functional and structural outcome. Results: There were significant improvements in the mean short- and long-term PROMs compared to preoperatively that exceeded reported minimal clinically important differences and substantial clinical benefits. There was a slight decrease in the PROMs from the short-term to long-term follow-up. Male sex and traumatic rotator cuff tears were associated with better long-term outcomes. The number of medical co-morbidities was associated with worse long-term outcomes. Smaller initial tear size was associated with better long-term outcomes. There were 15 (31%) full thickness and 9 (18%) partial thickness recurrent rotator cuff tears, 17 (35%) had rotator cuff tear arthropathy (2 Hamada grade 1, 15 Hamada grade 2), 5 (10%) had revision surgery (2 revision RCR, 2 anatomic total shoulder, and 1 reverse total shoulder), and 13 (26%) had subsequent contralateral RCR. There were weak correlations between the presence of arthropathy and DASH (r = 0.34; P = .02) and visual analog scale pain (r = 0.29; P = .049). There were no significant correlations between the structural outcomes (recurrent rotator cuff tear, recurrent full thickness tear, acromiohumeral space, and critical shoulder angle,) and the PROMs. Discussion and Conclusion: Long-term follow-up of RCR in this relatively young patient cohort demonstrated substantial and durable patient reported functional outcome and improvement despite considerable structural deterioration. This suggests that while RCR does not arrest the progression of rotator cuff disease it may delay this progression and that patients adapt to the structural changes as they age.

Comparison of Humeral-Head Replacement with Glenoid-Reaming Arthroplasty (Ream and Run) Versus Anatomic Total Shoulder Arthroplasty: A Matched-Cohort Study.

BACKGROUND: Glenoid component failure is a major concern after anatomic total shoulder arthroplasty (aTSA). Ream and run (RnR) is an alternative procedure that may avoid glenoid-related complications. The purpose of this study was to compare outcomes of RnR versus aTSA in younger patients with advanced glenohumeral osteoarthritis. METHODS: This was a retrospective matched-cohort study of 110 patients who underwent aTSA and 57 patients who underwent RnR; patients were <66 years of age and had a minimum of 2 years of follow-up. Propensity matching was performed using 21 preoperative variables. Pre- and postoperative patient-reported outcome measures (PROMs) and health-related quality-of-life (HRQoL) scores, satisfaction with outcome, and revision data were analyzed. Mixed-effects models examined the association of preoperative variables with outcomes. RESULTS: Thirty-nine patient pairs were matched. All patients were male, with a mean age of 58.6 ± 7.3 years and a mean follow-up 4.4 ± 2.3 years. The aTSA cohort had better final Simple Shoulder Test (SST) and American Shoulder and Elbow Surgeons (ASES) scores. However, in the mixed-effects model analysis, arthroplasty type was not associated with outcome. At 2 years postoperatively, a significantly greater percentage of aTSA patients achieved the substantial clinical benefit (SCB) for the ASES (100% versus 79.2%; p = 0.01) and the minimal clinically important difference (MCID) (89.7% versus 75%; p = 0.02) for the visual analog scale (VAS) for pain. At >5-year follow-up, there were no significant differences between the cohorts in the percentage who achieved the MCID, SCB, or patient acceptable symptom state (PASS) for the ASES, SST, and VAS for pain. Three patients underwent revision arthroplasty for pain after RnR, at a mean of 1.9 ± 1.7 years. Two patients underwent revision arthroplasty for glenoid loosening at 9.2 and 14 years after aTSA. CONCLUSIONS: RnR and aTSA had comparable outcomes in most analyses. The greater early revision rate after RnR should focus attention on optimizing patient selection and postoperative management. Revision for glenoid loosening is a concern among younger and active patients. Longer-term study is needed to better understand the relative benefits and disadvantages of these procedures. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Supplementary Fixation Improves Stability of Intra-Articular Distal Radius Fractures Managed With a Spanning Plate.

PURPOSE: Previous studies evaluating weight bearing of distal radius fractures treated through dorsal spanning bridge plates used extra-articular fracture models, and have not evaluated the role of supplementary fixation. We hypothesized that supplementary fixation with a spanning dorsal bridge plate for an intra-articular wrist fracture would decrease the displacement of individual articular pieces with cyclic axial loading and allow for walker or crutch weight bearing. METHODS: Thirty cadaveric forearms were matched into 3 cohorts, controlling for age, sex, and bone mineral density. An intra-articular fracture model was fixed with the following 3 techniques: (1) cohort A with a dorsal bridge plate, (2) cohort B with a dorsal bridge plate and two 1.6-mm k-wires, and (3) cohort C with a dorsal bridge plate and a radial pin plate. Specimens were axially loaded cyclically with escalating weights consistent with walker and crutch weight-bearing with failure defined as 2-mm displacement. RESULTS: No specimens failed at 2- or 5-kg weights, but cohort A had significantly more displacement at these weights compared with cohort B. Cohort A had significantly more failure than cohort C. Both cohort A and cohort B had significantly more displacement at crutch weight bearing compared with cohort C. The supplementary fixation group had significantly lower displacement at crutch weight-bearing compared with cohort A in all gaps. Survival curves demonstrated the fixation cohort to survive higher loads than the nonfixation group. CONCLUSION: There was significantly less displacement and less failure of intra-articular distal radius fractures treated with a spanning dorsal bridge plate and supplementary fixation. Our model showed that either type of fixation was superior to the nonfixation group. CLINICAL SIGNIFICANCE: When considering early weight-bearing for intra-articular distal radius fractures treated with a spanning dorsal bridge plate, supplementary fixation may be considered as an augmentation to prevent fracture displacement.

Short-term clinical and radiographic outcomes in patients treated with a modern intramedullary nailing system for 2-part proximal humerus fractures.

OBJECTIVES: The optimal surgical treatment of displaced proximal humerus fractures (PHFs) remains controversial. There are advocates for both open reduction and internal fixation with plate and screws (ORIF) and intramedullary nailing (IMN). The purpose this study was to evaluate the early-term clinical and radiographic outcomes of IMN for isolated, displaced 2-part surgical neck PHFs using a modern, straight nail system and to determine the effect of preoperative patient and fracture characteristics on outcome. METHODS: This was a case series of 23 patients with displaced 2-part surgical neck PHFs who were treated with ORIF using a straight IMN with minimum follow-up of 1 year (mean 2.5 years [range, 1.1-4.6]). Patients were identified retrospectively and contacted for measurement of active range of motion (AROM) and patient reported outcome measures (PROMs) including the American Shoulder and Elbow Surgeons (ASES) score, Oxford Shoulder Score (OSS), and Single Assessment Numeric Evaluation (SANE), EuroQol-5D (EQ-5D), and Visual Analog Scale Pain score (VAS Pain). Plain radiographs were evaluated to assess the quality of the reduction and failure of fixation. Complications and reoperations were identified. RESULTS: Reduction was anatomic in 12 (52%) patients, acceptable in 9 (39%), and 2 (9%) were malreduced. There were no differences in reduction quality based on sex (p = 0.37), age at surgery (p = 0.68), calcar comminution (p = 0.68), number of screws in the head (p = 0.99), or medial hinge disruption (p = 0.06). At final follow-up, the mean ASES score was 92 ± 10, OSS was 45 ± 4, SANE was 93 ± 7, EQ-5D of 0.85 ± 0.17, and VAS Pain was 0 ± 1. The mean active forward flexion was 143° ± 16°, active external rotation was 68° ± 20°, and internal rotation was T11 ± 4 vertebrae. Two (9%) patients underwent reoperation and 2 (9%) patients experienced clinical failure not requiring reoperation. CONCLUSIONS: Straight IMN is a reliable treatment for displaced 2-part surgical neck PHFs with excellent radiographic and clinical outcomes in early follow-up. The implant facilitated anatomic or acceptable alignment of the fracture in the vast majority of patients.

Hydrogel treatment for idiopathic osteoarthritis in a Dunkin Hartley Guinea pig model.

The study objective was to determine if intraarticular injections of an extracellular matrix (ECM) powder and blood composite (ECM-B) would have a significant impact on post-operative gait parameters without eliciting adverse cartilage changes or severe lymphatic reactions in an idiopathic osteoarthritis (OA) model. Twenty-one Dunkin Hartley Guinea pigs received an intraarticular injection of ECM-B in each knee and were split into sub-groups for gait assessment and post-harvest knee evaluations at 1 week (n = 5), 2 weeks (n = 5), 4 weeks (n = 5), or 8 weeks (n = 6). The results were compared with a control group (n = 5), which underwent bilateral injections of phosphate-buffered saline (PBS), gait measurements at 1, 2, 4, and 8 weeks, and post-mortem knee evaluation at 8 weeks post-injection. Hind limbs and popliteal lymph nodes were collected at the Week 8 endpoint and underwent histological analysis by a veterinary pathologist. Significant improvement in hind limb base of support was observed in the ECM-B group compared to the control group at Week 4 but was no longer significant by Week 8. No significant differences were observed between control and ECM-B groups in hind limb cartilage, synovium, or popliteal lymph node histology at Week 8. In conclusion, administration of an ECM-B material may improve gait for a limited time without significant adverse effects on the cartilage, synovium, or local lymph nodes.

Bone morphological changes of the trapezium and first metacarpal with early thumb osteoarthritis progression.

BACKGROUND: Thumb carpometacarpal osteoarthritis is characterized by osteophyte growth and changes in the curvature of the articular surfaces of the trapezium and first metacarpal. The aim of this longitudinal study was to quantify in-vivo bone morphology changes with osteoarthritis progression. METHODS: The study analyzed an observational dataset of 86 subjects with early thumb osteoarthritis and 22 age-matched asymptomatic controls. CT scans of subjects' affected hands were acquired at enrollment (year 0), and at 1.5, 3, 4.5, and 6-year follow-up visits. Osteoarthritic subjects were classified into stable and progressive groups, as defined by osteophyte volume and the rate of osteophyte growth. Trapezium height, width, and volar facet recession, along with first metacarpal volar beak recession and recession angle, were quantified. FINDINGS: Mean trapezium width increased 12% over six years in the progressive osteoarthritis group. Trapezium volar recession of the progressive osteoarthritis group was significantly greater than stable at enrollment (P < 0.0001) and year 6 (P < 0.0001). The first metacarpal volar beak of the progressive osteoarthritis group recessed significantly faster than stable (P = 0.0004) and control (P = 0.0003). In year 6, volar beak surfaces in subjects with progressive osteoarthritis were flatter with reduced curvature, measuring -8.7 ± 4.0 degrees, compared to the stable osteoarthritis (P < 0.0001) and control groups (P = 0.0003), which maintained nominal curvatures, measuring 0.7 ± 2.5 and 0.2 ± 3.2 degrees, respectively. INTERPRETATION: Our results demonstrate significant recession and reduction in the angle of the first metacarpal volar beak in progressive osteoarthritis. Flattening of the first metacarpal volar beak may have important associations with carpometacarpal joint contact and loading migrations, further propagating osteophyte formation and bony remodeling. This work highlights the volar beak of the first metacarpal as a region of morphology change with disease.