Does sex matter in musculoskeletal health? A workshop report

Incidence of bony Bankart lesions in Sweden: a study of 790 cases from the Swedish fracture register

BACKGROUND

A bony Bankart lesion directly affects the stability of the shoulder by reducing the glenoid joint-contact area. The aim of this study was to report on the epidemiological data relating to bony Bankart lesions in Sweden using the Swedish fracture register. The purpose is to evaluate age and sex distribution in the population with bony Bankart lesions, its impact on treatment strategy and further to analyse patient-reported outcomes.

METHODS

This was an epidemiological descriptive study. The inclusion criteria were all patients with a unilateral bony Bankart lesion registered between April 2012 and April 2019. The patients' specific data (age, sex, type and time of injury, treatment option and patient-reported outcomes) were extracted from the Swedish fracture register database.

RESULTS

A total of 790 unilateral bony Bankart fractures were identified. The majority of the patients were male (58.7%). The median age for all patients at the time of injury was 57 years. Females had a higher median age of 66 years, compared with males, 51 years. Most of the bony Bankart lesions, 662 (91.8%), were registered as a low-energy trauma. More than two-thirds of all treatment registered cases, 509/734 patients (69.3%), were treated non-surgically, 225 (30.7%) were treated surgically, while, in 17 patients (7.5% of all surgically treated patients), the treatment was changed from non-surgical to surgical due to recurrent instability. Surgical treatment was chosen for 149 (35%) of the males and for 76 (25%) of the females. Patient quality of life decreased slightly in both surgically and non-surgically treated groups 1 year after bony Bankart injury.

CONCLUSION

This national register-based study provides detailed information on the epidemiology, choice of treatment and patient-reported outcomes in a large cohort of bony Bankart lesions. Most bony Bankart lesions affected males between 40 and 75 years after low-energy falls and non-surgical treatment dominated.

Sex- and Gender-specific Analysis in Orthopaedic Studies

BACKGROUND

Orthopaedic studies have reported the prevalence of injuries and outcomes after treatment in men and women patients, and although these differences have been recognized, few studies have evaluated for gender-specific injury patterns, disease progression, and treatment outcomes. A thorough understanding of gender-related differences is important to better individualize treatment and improve outcomes.

QUESTIONS/PURPOSES

In this study, we sought (1) to determine the proportion of studies published in six orthopaedic journals that provided sex- or gender-specific analyses in 2016 and whether a difference was found in outcomes between men and women and (2) to evaluate whether this proportion varied across several orthopaedic subspecialty journals or between general orthopaedic journals and subspecialty journals.

METHODS

Six leading orthopaedic surgery journals were selected for review, including two general orthopaedic journals (Journal of Bone and Joint Surgery and Clinical Orthopaedics and Related Research®) and four subspecialty journals (American Journal of Sports Medicine, Journal of Arthroplasty, Journal of Shoulder and Elbow Surgery, and Spine). Journal issues published in the even-numbered months of 2016 were reviewed for clinical randomized controlled, cohort, and case-control studies in which women were a part of the study population. A total of 712 studies evaluating 24,607,597 patients met the criteria and were included in our review of publications from 2016. The selected studies were stratified based on whether gender was a variable in a multifactorial statistical model. Outcomes of interest included the proportion of patients who were women and the presence or absence of a gender-specific analysis. These endpoints were compared between journals.

RESULTS

Overall, 55% (13,565,773 of 24,607,597) of patients analyzed in these studies were women. Only 34% (241 of 712) of the studies published in 2016 included gender as variable in a multifactorial statistical model. Of these, 39% (93 of 241) demonstrated a difference in the outcomes between patients who were men and women. The Journal of Arthroplasty had the greatest percentage of patients who were women (60%, 9,251,068 of 15,557,187) and the American Journal of Sports Medicine had the lowest (44%, 1,027,857 of 2,357,139; p < 0.001). Orthopaedic subspecialty journals tended to include a greater percentage of women (54%) than did general orthopaedic journals (50%; p = 0.04).

CONCLUSION

Currently, it is unclear what percentage of published orthopaedic studies should include a gender-specific analysis. In the current study, more than one-third of publications that performed a gender-specific analysis demonstrated a difference in outcomes between men and women, thereby emphasizing the need to determine when such an analysis is warranted.

CLINICAL RELEVANCE

Future studies should aim to determine when a gender-specific analysis is necessary to improve the management of orthopaedic injuries in men and women. It is important for investigators at the individual-study level to look for every opportunity to ensure that both men's and women's health needs are met by performing appropriate by-sex and by-gender analyses, but not to perform them when they are unnecessary or inappropriate.

Implant Surface Design Regulates Mesenchymal Stem Cell Differentiation and Maturation

Changes in dental implant materials, structural design, and surface properties can all affect biological response. While bulk properties are important for mechanical stability of the implant, surface design ultimately contributes to osseointegration. This article reviews the surface parameters of dental implant materials that contribute to improved cell response and osseointegration. In particular, we focus on how surface design affects mesenchymal cell response and differentiation into the osteoblast lineage. Surface roughness has been largely studied at the microscale, but recent studies have highlighted the importance of hierarchical micron/submicron/nanosurface roughness, as well as surface roughness in combination with surface wettability. Integrins are transmembrane receptors that recognize changes in the surface and mediate downstream signaling pathways. Specifically, the noncanonical Wnt5a pathway has been implicated in osteoblastic differentiation of cells on titanium implant surfaces. However, much remains to be elucidated. Only recently have studies been conducted on the differences in biological response to implants based on sex, age, and clinical factors; these all point toward differences that advocate for patient-specific implant design. Finally, challenges in implant surface characterization must be addressed to optimize and compare data across studies. An understanding of both the science and the biology of the materials is crucial for developing novel dental implant materials and surface modifications for improved osseointegration.

Laser Sintered Porous Ti-6Al-4V Implants Stimulate Vertical Bone Growth

The objective of this study was to examine the ability of 3D implants with trabecular-bone-inspired porosity and micro-/nano-rough surfaces to enhance vertical bone ingrowth. Porous Ti-6Al-4V constructs were fabricated via laser-sintering and processed to obtain micro-/nano-rough surfaces. Male and female human osteoblasts were seeded on constructs to analyze cell morphology and response. Implants were then placed on rat calvaria for 10 weeks to assess vertical bone ingrowth, mechanical stability and osseointegration. All osteoblasts showed higher levels of osteocalcin, osteoprotegerin, vascular endothelial growth factor and bone morphogenetic protein 2 on porous constructs compared to solid laser-sintered controls. Porous implants placed in vivo resulted in an average of 3.1 ± 0.6 mm³ vertical bone growth and osseointegration within implant pores and had significantly higher pull-out strength values than solid implants. New bone formation and pull-out strength was not improved with the addition of demineralized bone matrix putty. Scanning electron images and histological results corroborated vertical bone growth. This study indicates that Ti-6Al-4V implants fabricated by additive manufacturing to have porosity based on trabecular bone and post-build processing to have micro-/nano-surface roughness can support vertical bone growth in vivo, and suggests that these implants may be used clinically to increase osseointegration in challenging patient cases.

Prospective, Longitudinal Evaluation of Gender Differences After Total Hip Arthroplasty

Temporal trends in survivorship, patient-reported outcomes, and activity levels following total hip arthroplasty were compared between 61 men and 127 women. Overall implant survivorship was excellent for both genders. Similar functional improvements were found between men and women out until 5 years. Some gender differences were observed: men had a faster time to functional recovery and higher preoperative Short-Form 12-item survey mental component scores, whereas women had a significant improvement in Short-Form 12-item survey mental component scores. Increased understanding of these differences by patients and surgeons, combined with gender-based interventions, may further advance outcomes for these patients.

Sex differences in factors influencing recovery from arthroscopic knee surgery

BACKGROUND

Many factors affect recovery from arthroscopic partial meniscectomy, including patient sex. However, sex differences in time to maximal recovery of knee function and factors influencing differential rates of recovery are unknown.

QUESTIONS/PURPOSES

We determined (1) preoperative sex differences, (2) sex differences in rate and extent of recovery through 1 year postoperatively, and (3) clinical and fitness variables that could explain potential sex differences in recovery from partial meniscectomy.

PATIENTS AND METHODS

The study sample consisted of 180 patients undergoing arthroscopic partial meniscectomy. Sex, age, body mass index, history of prior injury, length of time between knee injury/impairment and surgical evaluation, weekly exercise frequency, and self-reported fitness were assessed preoperatively, and extent of osteoarthritis was recorded postoperatively. We used the Tegner-Lysholm scale to assess knee function preoperatively and postoperatively at weeks 1, 3, 8, 16, 24, and 48 followups.

RESULTS

Females had worse knee function and delayed maximal recovery, requiring 1 year, compared with males, who required only 4 months. History of prior knee injury and lower self-reported fitness were associated with slower recovery in females but not in males. Osteoarthritis was associated with slower recovery but not related to sex. Body mass index, length of time between injury/impairment and surgical evaluation, and weekly exercise frequency did not influence rate of recovery.

CONCLUSIONS

Females have delayed recovery after arthroscopic partial meniscectomy. Prior knee injury and self-reported low fitness are associated with delayed recovery for females but not for males.

Donor sex and age influence the chondrogenic potential of human femoral bone marrow stem cells

OBJECTIVE

Damaged articular cartilage does not heal well and can progress to osteoarthritis (OA). Human bone marrow stem cells (BMC) are promising cells for articular cartilage repair, yet age- and sex-related differences in their chondrogenesis have not been clearly identified. The purpose of this study is to test whether the chondrogenic potential of human femoral BMC varies based on the sex and/or age of the donor.

DESIGN

BMC were isolated from 21 males (16-82 years old (y.o.)) and 20 females (20-77 y.o.) during orthopaedic procedures. Cumulative population doubling (CPD) was measured and chondrogenesis was evaluated by standard pellet culture assay in the presence or absence of transforming growth factor beta 1 (TGFbeta1). Pellet area was measured, and chondrogenic differentiation was determined by Toluidine blue and Safranin O-Fast green histological grading using the Bern score and by glycosaminoglycan (GAG) content.

RESULTS

No difference in CPD was observed due to donor sex or age. The increase in pellet area with addition of TGFbeta1 and the Bern score significantly decreased with increasing donor age in male BMC, but not in female BMC. A significant reduction in GAG content per pellet was also observed with increasing donor age in male BMC. This was not observed in female BMC.

CONCLUSIONS

This study showed an age-related decline in chondroid differentiation with TGFbeta1 stimulation in male BMC, but not in female BMC. Understanding the mechanisms for these differences will contribute to improved clinical use of autologous BMC for articular cartilage repair, and may lead to the development of customized age- or sex-based treatments to delay or prevent the onset of OA.