Current Understanding of the Regulatory Mechanism of Tooth Root Development and Future Perspectives.

Background: The purpose of this review article is to understand tooth root development and its regulation through evolution and epigenetics as well as future implications involving root regeneration and tissue engineering. Types of Studies Reviewed: we performed a comprehensive PubMed search to review all published studies related to the molecular regulation of tooth root development and regeneration until August 2022. Articles selected include original research studies and reviews. Results: Epigenetic regulation strongly influences dental tooth root patterning and development. One study highlights how genes such as Ezh2 and Arid1a are crucial components in the development of tooth root furcation patterning. Another study shows that loss of Arid1a ultimately leads to shortened root morphology. Furthermore, researchers are utilizing information about root development and stem cells to find alternative treatments in replacing missing teeth through a stem cell-mediated bioengineered tooth root (bio-root). Practical Implications: Dentistry values preserving natural tooth morphology. Presently, implants are the best treatment for replacing missing teeth, but alternative future treatments might include tissue engineering/bio-root regeneration to restore our dentition.

Minimally Invasive Repair of Subacute Achilles Tendon Ruptures: A Report of 2 Cases.

LEVEL OF EVIDENCE: Level IV: Case report.

Biomechanical Comparison of a Novel Method of Tricortical Kirschner Wire Fixation of Distal Chevron Osteotomies of the First Metatarsal Versus Traditional Kirschner Wire and Versus Screw Fixation.

INTRODUCTION: Traditional Kirschner wire (K-wire) stabilization of first metatarsal distal chevron osteotomy involves 1 cortex of fixation; however, unicortical fixation is associated with a high complication rate, including pin migration. A method of K-wire fixation utilizing 3 cortices may be biomechanically superior and potentially equivalent to single-screw fixation. METHODS: Cadaveric specimens fixed with tricortical K-wires were tested in both the physiologic and cantilever conditions against specimens fixed with unicortical K-wires (N = 8) and single screws (N = 9) utilizing matched-pair comparison groups. Differences in physiologic and cantilever fixed/intact stiffness ratio and cantilever failure load were determined. RESULTS: The tricortical fixation specimens had a significantly higher stiffness ratio in cantilever loading than the unicortical fixation specimens (60.50% tricortical, 34.17% unicortical, P = .02) but not in physiologic load (15.34% tricortical, 25.75% unicortical, P = .23). In cantilever failure loading, the tricortical fixation specimens had a significantly higher load to failure than the unicortical fixation specimens (132.81 N tricortical, 58.58 N unicortical, P < .01). Stiffness ratio under physiologic load, cantilever load, and ultimate load to failure were not significantly different between tricortical K-wire and screw-fixation groups. CONCLUSION: Tricortical K-wire fixation for distal chevron osteotomies is biomechanically superior to traditional unicortical K-wire fixation, and equivalent to single-screw fixation. LEVELS OF EVIDENCE: Level V: Cadaver study.

The Legal, Ethical, and Scientific Considerations for Returning Explanted Orthopaedic Hardware to the Patient.

ABSTRACT: Orthopaedic hardware explantation is a multifaceted topic with complex legal, ethical, and scientific aspects that require thorough exploration. Issues of device ownership, explant-induced disease propagation, and potential device resale pose legal risks to providers and health-care institutions. Ethically, implant removal highlights the potential that performing procedures at the request of the patient will incentivize patient compliance and strengthen the patient-surgeon relationship. However, the return of explanted hardware to patients could hinder scientific study and innovation, ultimately limiting advancement in risk reduction and patient outcomes. Continued research into these topics remains paramount to ensure that clinicians and institutions deliver optimal patient care while abiding with legal and ethical imperatives. This article addresses the legal, ethical, and scientific issues that are pertinent to returning an explanted orthopaedic implant to the patient and the potential ramifications of such practice.

Use of Ultrasonically Interdigitated Anchors in Haglund's Deformity Correction Surgery.

Haglund's deformity is a common cause of foot pain, with high success rates of surgical intervention. Because early weightbearing rehabilitation correlates with better surgical results, the integrity of anchors employed in these surgeries needs to be evaluated for proper fixation strength, leading to improved postoperative outcomes. The ultrasonically interdigitated anchor is a biodegradable suture anchor that is melted into bony trabeculae using ultrasound, leaving a small biological footprint and less interference on computed tomography and magnetic resonance imaging scans, without loss of fixation strength. We performed a review of 44 patients aged 26 to 84 years treated with either ultrasonically interdigitated anchors or fully threaded titanium anchors during Haglund's deformity excision. Overall, 7 of 14 patients who received an ultrasonically interdigitated anchor reported raw PROMIS (Patient-Reported Outcomes Measurement Information System) scores averaging 14.3, with an average return to ambulation time of 4.2 weeks. Fifteen of 30 patients receiving a fully threaded titanium anchor reported raw PROMIS scores averaging 9.7, with an average return to ambulation time of 3.5 weeks. We found little difference between the outcomes between the 2 anchors and no massive failures or infections in either group, implying that ultrasonically interdigitated anchors are a viable option for Achilles tendon reattachment during Haglund's deformity repair surgery.Levels of Evidence: Level III: Case control study.

Serial Surgical Debridement and Fixation of Chronic Pelvis Instability Secondary to Pubic Symphysis and Sacroiliac Osteomyelitis: A Case Report.

Introduction: Chronic global pelvic instability can be due to many different etiologies with infection being an uncommon cause. We present a case of chronic global pelvis instability secondary to osteomyelitis involving both the anterior and posterior ring, a rare and challenging problem with no standard treatment. Case Presentation: A 57-year-old female with a history of intravenous drug use presented with global pelvis instability in the setting of pubic symphysis and posterior sacroiliac osteomyelitis with multiple-associated abscesses. She was managed with serial surgical debridement's X4 and combined anterior and posterior fixation/fusion, with resolution of her infection and instability. Conclusions: This is the first reported case of chronic pelvis instability secondary to anterior and posterior pelvic ring osteomyelitis that was successfully treated with serial debridement and combined anterior and posterior fixation/fusion.

Biomechanical Evaluation of Humerus Fracture After Subpectoral Biceps Tenodesis With Interference Screw Versus Unicortical Button.

PURPOSE: To compare the torsional failure strength of the humerus after subpectoral biceps tenodesis with an interference screw versus a unicortical button in a human cadaveric model. METHODS: Thirteen matched pairs of fresh-frozen human cadaveric upper extremities were randomized to receive either 2.6 × 12 mm unicortical button or 6.25-mm interference screw subpectoral biceps tenodesis. After the procedure, the humeri were loaded into a materials testing machine. The humeri were loaded in external rotation with respect to the elbow at 1.0°/s until failure. Rotation angle to failure, failure torque, energy absorbed, and stiffness were compared by paired t-tests with alpha set at 0.05. RESULTS: Humeri that were fixed with unicortical buttons showed statistically significant higher rotation to failure (26.87 ± 5.83 vs 19.04 ± 3.86°, P < .001), failure torque (54.11 ± 22.01 vs 44.95 ± 17.47 Nm, P < .001), and energy absorbed (883.93 ± 582.28 vs 451.40 ± 216.19 Nm-Deg, P = .002) than humeri fixed with interference screws. CONCLUSIONS: In a cadaveric biomechanical model, at time 0, the use of a 2.7 × 12-mm unicortical button fixation in biceps tenodesis resulted in higher loads required to fracture the humerus when compared with a 6.25-mm interference screw fixation in a torsion model. CLINICAL RELEVANCE: This study demonstrates a significant biomechanical difference with regards to fracture of the humerus, between 2 commonly used fixations methods and implant sizes, interference screw, and unicortical button. The results of this study can aid surgeons in implant selection as well as help to improve patient education prior to surgery.

Minocycline-induced hyperpigmentation in rheumatoid arthritis.

BACKGROUND: Minocycline is recognized as an effective, well-tolerated therapy in rheumatoid arthritis (RA), although its use has been associated with the development of cutaneous hyperpigmentation. OBJECTIVES: To assess the clinical determinants and frequency of minocycline-induced hyperpigmentation in patients with RA. METHODS: A retrospective medical record review of all patients with RA seen in 2 academic rheumatology practices was performed to identify subjects who had received at least 1 month of continuous minocycline therapy. Patient demographics, disease characteristics, medication use, and medication side effects were abstracted from the medical record. Using Cox proportional hazards regression and restricting the analysis to the initial minocycline course, we examined the association of patient factors and concomitant medications with the development of hyperpigmentation. RESULTS: Of 121 patients with at least 1 minocycline course of 30 days or more, 44 (36%) developed documented hyperpigmentation, including 33 during the initial course over a median duration of 9.1 month (range 2.2-77.8 months). Hyperpigmentation was most commonly seen on the upper and lower extremities and the head/neck region. Minocycline-induced hyperpigmentation led to the discontinuation of treatment in 3 patients, with 12 additional patients receiving a dose reduction. Increasing age was the only clinical determinant significantly associated with hyperpigmentation (HR = 1.04; 95% CI 1.00-1.07, P = 0.04). There were no significant associations of sex, weight, concomitant prednisone, or aspirin use with the development of hyperpigmentation. CONCLUSIONS: Minocycline-induced hyperpigmentation is a common complication seen with minocycline use in the treatment of RA, and seems to increase with age.

Prospective study of survival outcomes in Non-Hodgkin's lymphoma patients with rheumatoid arthritis.

PURPOSE: Although preliminary studies suggest that non-Hodgkin's lymphoma (NHL) complicating rheumatoid arthritis (RA) may be a clinically distinct entity compared with that occurring in the general population, studies examining the impact of antecedent RA on survival are limited. In this prospective study, we examined the association of RA with survival in patients with NHL. PATIENTS AND METHODS: Using two large lymphoma registries, we identified patients with evidence of RA preceding NHL. Survival in RA patients was compared with that of controls using proportional hazards regression, adjusting for the effects of age, sex, lymphoma diagnosis-to-treatment lag time, calendar year, International Prognostic Index score, and NHL grade. RESULTS: The frequency of NHL subtypes was similar in RA patients (n = 65) and controls (n = 1,530). Compared with controls, RA patients with NHL had similar overall survival (hazard ratio [HR] = 0.95; 95% CI, 0.70 to 1.30) but were at lower risk of lymphoma progression or relapse (HR = 0.41; 95% CI, 0.25 to 0.68) or death related to lymphoma or its treatment (HR = 0.60; 95% CI, 0.37 to 0.98), but were more than twice as likely to die from causes unrelated to lymphoma (HR = 2.16; 95% CI, 1.33 to 3.50). CONCLUSION: RA is associated with improved NHL-related outcomes, including a 40% reduced risk of death occurring as a result of lymphoma or its treatment and approximately a 60% lower risk of lymphoma relapse or progression compared with non-RA controls. However, the survival advantage gained in RA from the acquisition of lymphomas with favorable prognoses is negated through an increased mortality from other comorbid conditions.