Prevalence and Treatment of Osteoporosis Prior to Elective Shoulder Arthroplasty.

INTRODUCTION: The rate of preoperative osteoporosis in lower extremity arthroplasty is 33%. The prevalence of osteoporosis in shoulder arthroplasty patients is inadequately studied. The purpose of this study was to (1) determine the prevalence of osteoporosis in patients undergoing elective shoulder arthroplasty, (2) report the percentage of patients having dual-energy x-ray absorptiometry (DEXA) testing before surgery, and (3) determine the percentage of patients who have been prescribed osteoporosis medications within 6 months before or after surgery. METHODS: This retrospective case series included all adults aged 50 years and older who underwent elective shoulder arthroplasty at a single tertiary care center over an 8-year period. National Osteoporosis Foundation (NOF) criteria for screening and treatment were applied. RESULTS: Two hundred fifty-one patients met the inclusion criteria; 171 (68%) met the criteria for DEXA testing, but only 31 (12%) had this testing within 2 years preoperatively. Eighty patients (32%) met the NOF criteria for receipt of pharmacologic osteoporosis treatment, and 17/80 (21%) received a prescription for pharmacotherapy. DISCUSSION: Two-thirds of elective shoulder arthroplasty patients meet the criteria to have bone mineral density measurement done, but less than 20% have this done. One in three elective shoulder arthroplasty patients meet the criteria to receive osteoporosis medications, but only 20% of these patients receive therapy.

Osteoporosis Is Common and Undertreated Prior to Total Joint Arthroplasty.

BACKGROUND: Osteoporosis is common in total joint arthroplasty (TJA) patients and likely contributes to the increasing incidence of periprosthetic fracture. Despite this, the prevalence of osteoporosis in patients undergoing elective TJA is inadequately studied. We hypothesize that preoperative osteoporosis is underrecognized and undertreated in the TJA population. The purpose of this study is to report preoperative osteoporosis screening rates and prevalence prior to TJA and rates of pharmacologic osteoporosis treatment in the TJA population. METHODS: This is a retrospective case series of 200 consecutive adults (106F, 94M) aged 48-92 years who underwent elective TJA (100 total hip, 100 total knee) at a single tertiary-care center. Charts were retrospectively reviewed to determine preoperative osteoporosis risk factors, prior dual-energy X-ray absorptiometry (DXA) testing, and prior osteoporosis pharmacotherapy. Fracture risk was estimated using the Fracture Risk Assessment Tool and the National Osteoporosis Foundation criteria for screening and treatment were applied to all patients. RESULTS: One hundred nineteen of 200 patients (59.5%) met criteria for DXA testing. Of these 119, 21 (17.6%) had DXA testing in the 2 years prior to surgery, and 33% had osteoporosis by T-score. Forty-nine patients (24.5%) met National Osteoporosis Foundation criteria for pharmacologic osteoporosis treatment, and 11 of these 49 received a prescription for pharmacotherapy within 6 months before or after surgery. CONCLUSION: One quarter of TJA patients meet criteria to receive osteoporosis medications, but only 5% receive therapy preoperatively or postoperatively. This lack of preoperative osteoporosis screening and treatment may contribute to periprosthetic fracture risk.

Crimp length decreases in lax tendons due to cytoskeletal tension, but is restored with tensional homeostasis.

Collagen crimp morphology is thought to contribute to the material behavior of tendons and may reflect the local mechanobiological environment of tendon cells. Following loss of collagen tension in tendons, tenocytes initiate a contraction response that shortens tendon length which, in turn, may alter crimp patterns. We hypothesized that changes in the crimp pattern of tendons are the result of cell-based contractions which are governed by relative tautness/laxity of the collagen matrix. To determine the relationship between crimp pattern and tensional homeostasis, rat tail tendon fascicles (RTTfs) were either allowed to freely contract or placed in clamps with 10% laxity for 7 days. The freely contracting RTTfs showed a significant decrease in percent crimp length on both day 5 (3.66%) and day 7 (7.70%). This decrease in crimp length significantly correlated with the decrease in freely contracting RTTf length. Clamped RTTfs demonstrated a significant decrease in percent crimp length on day 5 (1.7%), but no significant difference in percent crimp length on day 7 (0.57%). The results demonstrate that the tendon crimp pattern appears to be under cellular control and is a reflection of the local mechanobiological environment of the extracellular matrix. The ability of tenocytes to actively alter the crimp pattern of collagen fibers also suggests that tenocytes can influence the viscoelastic properties of tendon. Understanding the interactions between tenocytes and their extracellular matrix may lead to further insight into the role tendon cells play in maintaining tendon heath and homeostasis. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:573-579, 2017.