The measurement of bone mineral density of bilateral proximal humeri using DXA in patients with unilateral rotator cuff tear

Semi-automatic proximal humeral trabecular bone density assessment tool: technique application and clinical validation

PURPOSE

This study aimed to apply a newly developed semi-automatic phantom-less QCT (PL-QCT) to measure proximal humerus trabecular bone density based on chest CT and verify its accuracy and precision.

METHODS

Subcutaneous fat of the shoulder joint and trapezius muscle were used as calibration references for PL-QCT BMD measurement. A self-developed algorithm based on a convolution map was utilized in PL-QCT for semi-automatic BMD measurements. CT values of ROIs used in PL-QCT measurements were directly used for phantom-based quantitative computed tomography (PB-QCT) BMD assessment. The study included 376 proximal humerus for comparison between PB-QCT and PL-QCT. Two sports medicine doctors measured the proximal humerus with PB-QCT and PL-QCT without knowing each other's results. Among them, 100 proximal humerus were included in the inter-operative and intra-operative BMD measurements for evaluating the repeatability and reproducibility of PL-QCT and PB-QCT.

RESULTS

A total of 188 patients with 376 shoulders were involved in this study. The consistency analysis indicated that the average bias between proximal humerus BMDs measured by PB-QCT and PL-QCT was 1.0 mg/cc (agreement range - 9.4 to 11.4; P > 0.05, no significant difference). Regression analysis between PB-QCT and PL-QCT indicated a good correlation (R-square is 0.9723). Short-term repeatability and reproducibility of proximal humerus BMDs measured by PB-QCT (CV: 5.10% and 3.41%) were slightly better than those of PL-QCT (CV: 6.17% and 5.64%).

CONCLUSIONS

We evaluated the bone quality of the proximal humeral using chest CT through the semi-automatic PL-QCT system for the first time. Comparison between it and PB-QCT indicated that it could be a reliable shoulder BMD assessment tool with acceptable accuracy and precision. This study developed and verify a semi-automatic PL-QCT for assessment of proximal humeral bone density based on CT to assist in the assessment of proximal humeral osteoporosis and development of individualized treatment plans for shoulders.

Long-Term Effects of Reproduction and Lactation on the Rat Supraspinatus Tendon and Proximal Humerus

During pregnancy and breastfeeding, women undergo hormonal fluctuations required for fetal development, parturition, and infant growth. These changes have secondary consequences on the maternal musculoskeletal system, increasing the risk for joint pain and osteoporosis. Though hormone levels return to prepregnancy levels postpartum, women may experience lasting musculoskeletal pain. Sex disparities exist in the prevalence of musculoskeletal disorders, but it remains unclear how reproductive history may impact sex differences. Specifically, the effects of both reproductive history and sex on the rotator cuff have not been studied. Pregnancy and lactation affect bone microstructure, suggesting possible impairments at the enthesis of rotator cuff tendons, where tears commonly occur. Therefore, our objective was to evaluate how reproductive history affects sex differences of the supraspinatus tendon and proximal humerus using male, virgin female, and female rats with a history of reproduction (referred to as reproductive females). We hypothesized tendon mechanical properties and humeral bone microstructure would be inferior in reproductive females compared to virgin females. Results showed sex differences independent of reproductive history, including greater tendon midsubstance modulus but lower subchondral bone mineral density (BMD) in females. When considering reproductive history, reproductive rats exhibited reduced tendon insertion site modulus and trabecular bone micro-architecture compared to virgin females with no differences from males. Overall, our study identified long-term changes in supraspinatus tendon mechanical and humeral trabecular bone properties that result following pregnancy and lactation, highlighting the importance of considering reproductive history in investigations of sex differences in the physiology and pathology of rotator cuff injuries.

The Relationship Among Probable SARCopenia, Osteoporosis and SuprasPinatus Tendon Tears in Postmenopausal Women: The SARCOSP Study

We aimed to investigate the relationship among probable sarcopenia, osteoporosis (OP) and supraspinatus tendon (SSP) tears in postmenopausal women. Postmenopausal women screened/followed for OP were recruited. Demographic data, comorbidities, exercise/smoking status, and handgrip strength values were recorded. Probable sarcopenia was diagnosed as handgrip strength values < 20 kg. Achilles and SSP thicknesses were measured using ultrasound. Among 1443 postmenopausal women, 268 (18.6%) subjects had SSP tears. Unilateral tears were on the dominant side in 146 (10.1%) and on the non-dominant side in 55 women (3.8%). In contrast to those without, women with SSP tears had older age, lower level of education, thinner SSP and lower grip strength (all p < 0.05). In addition, they had higher frequencies of hypertension, hyperlipidemia, DM, OP and probable sarcopenia, but lower exercise frequency (all p < 0.05). Binary logistic regression modeling revealed that age [odds ratio (OR): 1.046 (1.024-1.067 95% CI)], hypertension [OR: 1.560 (1.145-2.124 95% CI)], OP [OR: 1.371 (1.022-1.839 95% CI)] and probable sarcopenia [OR: 1.386 (1.031-1.861 95% CI)] were significant predictors for SSP tears (all p < 0.05). This study showed that age, presence of hypertension, probable sarcopenia and OP were related with SSP tears in postmenopausal women. To this end, although OP appeared to be related to SSP tears, SSP tear/thickness evaluation can be recommended for OP patients, especially those who have other risk factors such as older age, higher BMI, hypertension, and probable sarcopenia.

Radiographic Evaluation and Changes in Bone Density of the Humeral Side after Reverse Total Shoulder Arthroplasty

After artificial joint surgery, bone density may decrease around the artificial joint; thus, postoperative bone density evaluation around the artificial joint is crucial. We investigated changes in bone mineral density and performed radiographic evaluation around the stem after reverse shoulder arthroplasty (RSA) surgery in 17 males (18 shoulders) and 19 females (19 shoulders), aged >65 years, with >1-year follow-up. In total, 20 and 17 cases involved massive rotator cuff tears and rotator cuff tear arthropathy, respectively. The Comprehensive Reverse Shoulder System (Standard Ingrowth) was used for all cases and cement was used in eight patients due to bone fragility. We examined lucent lines, loosening, bone resorption, and spot welds in non-cemented cases using plain radiography and postoperative bone density changes around the stem using dual-energy X-ray absorptiometry (DEXA). Lucent lines and bone resorption occurred in 5 (13.5%) and 19 (51.4%) shoulders, respectively. No loosening occurred. Compared to stem bone density at 2 weeks postoperatively, the decrease rate was the largest in the proximal medial humerus. One-year postoperative bone density was not related to sex, age, cement use, or preoperative diagnosis. Higher preoperative bone density was better maintained postoperatively. Furthermore, 1 year post RSA, spot welds were observed in approximately 48.2% of cases at the distal medial portion of the stem coating, and bone resorption occurred in the proximal medial humerus in 43.2% of cases. Therefore, postoperative bone density is related to preoperative bone density, suggesting the importance of maintaining high preoperative bone density.

Arthroscopic transosseous anchorless rotator cuff repair reduces bone defects related to peri-implant cyst formation: a comparison with conventional suture anchors using propensity score matching

BACKGROUND

The transosseous anchorless repair (ToR) technique was recently introduced to avoid suture anchor-related problems. While favorable outcomes of the ToR technique have been reported, no previous studies on peri-implant cyst formation with the ToR technique exist. Therefore, this study compared the clinical outcomes and prevalence of peri-implant cyst formation between the ToR technique and the conventional transosseous equivalent technique using suture anchors (SA).

METHODS

Cases with arthroscopic rotator cuff repair (ARCR) between 2016 and 2018 treated with the double-row suture bridge technique were retrospectively reviewed. Patients were divided into ToR and SA groups. To compare clinical outcomes, 19 ToR and 57 SA cases without intraoperative implant failure were selected using propensity score matching (PSM). While intraoperative implant failure rate was analyzed before PSM, retear rate, peri-implant cyst formation rate, and functional outcomes were compared after PSM.

RESULTS

The intraoperative implant failure rate (ToR, 8% vs. SA, 15.3%) and retear rate (ToR, 5.3% vs. SA, 19.3%) did not differ between the two groups (all P>0.05). However, peri-implant cysts were not observed in the ToR group, while they were observed in 16.7% of the SA group (P=0.008). Postoperative functional outcomes were not significantly different between the two groups (all P>0.05).

CONCLUSIONS

The ToR technique produced comparable clinical outcomes to conventional techniques. Considering the prospect of potential additional surgeries, the absence of peri-implant cyst formation might be an advantage of ToR. Furthermore, ToR might reduce the medical costs related to suture anchors and, thereby, could be a useful option for ARCR. Level of evidence: III.

Development of in vitro osteoporosis model in minipig proximal humerus and femur: validation in histological and biomechanical study

BACKGROUND

The minipig has been used for research in various fields of medicine, even in orthopedics. Though previous studies have already suggested other methods to create osteoporotic bone, those methods had some disadvantages for taking time and efforts. Therefore, we aimed to generate osteoporotic proximal humerus and proximal femur of minipig using EDTA solution and validate their properties through dual energy X-ray absorptiometry (DEXA), micro-CT study, histological and biomechanical ways.

METHODS

Six minipigs were used. Out of a total of 12 proximal humerus (PH) and 12 proximal femurs (PF), 6 PH and 6 PF were used as the decalcified group and the opposite side as the non-decalcified group. In vitro decalcification with Ca-chelating agents (0.5 M EDTA solution, pH 7.4) was used. Area BMD (aBMD) was measured using DEXA, Volumetric BMD (vBMD), and microstructure were measured using micro-CT. Universal testing machine was used to measure ultimate load to failure (ULTF). Each group was compared using two types of suture anchors (all-suture anchor, ASA, and conventional screw type anchor, CA).

RESULTS

There was a significant difference in aBMD and cortical thickness (aBMD: decalcified, 0.433 ± 0.073 g/cm2, undecalcified, 0.962 ± 0.123 g/cm2, p < 0.001; cortical thickness: decalcified, 0.33 ± 0.34 mm, undecalcified, 1.61 ± 0.45 mm, p < 0.001). In the case of ASA, the ULTF was significantly lower in the decalcified group (decalcified: 176.6 ± 74.2 N, non-decalcified: 307.7 ± 116.5 N, p = 0.003). In the case of CA, there was no significant difference (decalcified: 265.1 ± 96.0 N, undecalcified: 289.4 ± 114.5 N, p = 0.578).

CONCLUSION

We demonstrated that decalcification with EDTA solution significantly decreased aBMD, vBMD, and cortical thickness. Decalcified minipig bone using EDTA resulted in similar biomechanical properties as osteoporotic human bone with respect to anchor pull-out.

Osteoporosis does not affect bone mineral density change in the proximal humerus or the functional outcome after open reduction and internal fixation of unilateral displaced 3- or 4-part fractures at 12-month follow-up

BACKGROUND

The aim of this prospective study was to investigate bone mineral density (BMD) changes in the proximal humerus of the shoulder during a healing period of 12 months after displaced 3- or 4-part proximal humerus fractures treated with open reduction and internal fixation (ORIF) with an anatomic angular stable locking plate and the influence on fracture healing and functional outcomes.

METHODS

In a prospective multicenter study, 36 patients (29F and 7M, age range: 38-83) with unilateral displaced 3- or 4-part proximal humerus fractures were included for ORIF. Dual-energy x-ray absorptiometry for osteoporosis status was employed. Postoperative and 6-week, 3-, 6-, and 12-month shoulder radiographs and dual-energy x-ray absorptiometry of the shoulder with BMD measures in 4 templated regions of interest (ROIs) were performed. Functional outcomes, Western Ontario Osteoarthritis of the Shoulder index, Constant score, visual analog scale pain (VAS), and 36-Item Short Form Survey, were collected.

RESULTS

A total of 17 of 36 patients had osteoporosis. We found no differences in BMD changes, functional outcomes, radiology, or need for revision surgery between the osteoporosis and nonosteoporosis groups. The BMD values gradually declined from baseline to 3-month follow-up in all 4 ROIs of the operated shoulders. All 4 ROIs in the operated shoulder presented with a reduction in BMD at 3, 6, and 12 months compared with baseline, whereas no significant BMD changes were seen in the healthy shoulder during the study period. The functional outcomes displayed an increase in Constant score from 3 to 12 months, but a decrease in domains of the 36-Item Short Form Survey from preinjury to 12 months (physical functioning, general health, and bodily pain). Preinjury and 12-month Western Ontario Osteoarthritis of the Shoulder index, VAS pain at rest, and VAS pain at activity were comparable.

CONCLUSION

BMD changes appeared swiftly in the proximal humerus, after the treatment of displaced 3- or 4-part fractures with ORIF, particularly affecting the proximal diaphysis of the humerus. Shoulder function was restored to preinjury levels for most of the patients. Osteoporosis may not be regarded as a contraindication for the treatment of displaced 3- or 4-part fractures with ORIF.

Modified Alendronate Mitigates Mechanical Degradation of the Rotator Cuff in an Osteoporotic Ovine Model

BACKGROUND

Osteoporosis is an independent risk factor for failure after arthroscopic rotator cuff repair. Since rerupture rates after rotator cuff repair are associated with decreased bone mineral density and bone microarchitecture, adaptations of biomechanical properties of the rotator cuff enthesis in patients with osteoporosis remain unclear. Additionally, the effects of osteogenic therapy carrier drugs used for the treatment of osteoporosis on rotator cuff structure and properties have not been previously documented.

PURPOSE

To investigate the changes to soft tissue biomechanics and insertional structure secondary to osteoporosis with and without an osteogenic therapy carrier (ie, modified alendronate).

STUDY DESIGN

Controlled laboratory study.

METHODS

Biomechanical, histopathological, and microcomputed tomography analyses were performed on 20 shoulders obtained from 10 osteoporotic sheep randomly allocated to modified bisphosphonate (ie, alendronate) or control (ie, osteoporotic without treatment) groups; 6 shoulders from healthy sheep were utilized for comparison purposes.

RESULTS

Tendons from the control group exhibited a 57% decrease in undeformed Young modulus as compared with the healthy group (P = .010). Tendons from the modified bisphosphonate treatment group exhibited a 229% increase in initial Young modulus as compared with the control group (P = .010). Marked changes within the tendon insertional organization were noted in both the control and the modified bisphosphonate treatment group samples as evidenced by increased interdigitation of the bone-mineralized fibrocartilaginous junction. The control samples exhibited a markedly paucicellular insertion, whereas the modified bisphosphonate treated tendons exhibited a hypercellular insertional region as compared with the healthy group. Both groups exhibited significantly (P < .01) decreased bone quality underlying the infraspinatus insertion, as evidenced by all microcomputed tomography outcome parameters.

CONCLUSION

This work illuminates changes to rotator cuff tendon secondary to osteoporosis. Specifically, it revealed decreased tendon modulus and altered insertional structure in the osteoporotic samples. Secondarily, these data revealed increases in tendon modulus accompanied by increased cellularity within the tendon insertion region after systemic modified bisphosphonate injections.

CLINICAL RELEVANCE

Bisphosphonate treatment may have a positive effect on the healing of the enthesis after rotator cuff repair.

Humeral BMD can be Measured With DXA and Is Lower in the Surgical Arm After Total Shoulder Arthroplasty

BACKGROUND

As arthroplasty leads to bone loss, we hypothesized that humeral bone mineral density (BMD) is lower after total shoulder arthroplasty (TSA) in the operative versus non-operative arm. However, there is no clinical approach to measure humeral BMD with dual-energy x-ray absorptiometry (DXA). The purposes of this pilot study were to develop DXA methodology to measure humerus BMD, propose humerus regions of interest (ROIs), compare TSA BMD to the non-operative arm, correlate humeral BMD with standard sites, and evaluate measurement reproducibility.

METHODOLOGY

Thirty-eight adults 1-5 years post-TSA had standard clinical DXA scans plus full humerus scans using the atypical femur fracture feature; precision was assessed in a subset (n = 32). Six custom ROIs were used to measure BMD throughout the humerus. Radius and humeral BMD were compared between arms by paired t-test and correlated ipsilaterally using Pearson's Correlation. Custom ROI BMD precision was assessed using the International Society for Clinical Densitometry (ISCD) advanced precision calculator.

RESULTS

Study included 38 subjects (24M/14F), with mean (SD) age and time post-surgery of 69.6 (7.7) years and 2.5 (1.3) years respectively. BMD was lower (p &lt; 0.01) at all custom humerus sites (3.8% to 8.2%) on the surgical side but not different at radius sites. Humeral BMD correlated positively with ipsilateral ultra-distal and 1/3 radius (r = 0.54 to 0.86; p &lt; 0.05). Custom BMD precision (%CV) ranged from 6.0-16.0%.

CONCLUSIONS

Humerus BMD can be measured using DXA and is lower in the TSA arm. Radius BMD correlated with humeral BMD but was not lower in the surgical arm. BMD precision was worse than usual clinical sites; use of software optimized for the femur is a notable limitation and likely contributes to suboptimal precision. Further study to assess the clinical utility of humeral BMD is needed. Automation and optimization of these measurements should improve precision.

Risk factors of radiographic severity of massive rotator cuff tear

As massive rotator cuff tears progress, various radiographic changes occur; however, the factors associated with radiographic changes remain largely unknown. This study aimed to determine the factors that affect radiographic severity in massive rotator cuff tears using multivariate analyses. We retrospectively reviewed 210 shoulders with chronic massive rotator cuff tears. The dependent variables were superior migration of the humeral head (Hamada grades 2-3), narrowing of the glenohumeral joint (grade 4), and humeral head collapse (grade 5). Baseline variables that were significant in univariate analyses were included in multivariate models. There were 91, 59, 43, and 17 shoulders classified as Hamada grades 1, 2-3, 4, and 5, respectively. Multivariate analysis showed that infraspinatus tear (P = 0.015) and long head of biceps (LHB) tendon rupture (P = 0.007) were associated with superior migration of humeral head. Superior subscapularis tear (P = 0.003) and LHB tendon rupture (P < 0.001) were associated with narrowing of glenohumeral joint. Female sex (P = 0.006) and superior subscapularis tear (P = 0.006) were associated with humeral head collapse. This study identified the rupture of infraspinatus and LHB as risk factors of superior migration of humeral head, and the rupture of subscapularis and LHB and female sex as risk factors of cuff tear arthropathy.

Osteoporosis increases the risk of rotator cuff tears: a population-based cohort study

INTRODUCTION

Osteoporosis has been demonstrated to be a risk factor for rotator cuff retears after surgery; however, no studies have directly investigated the association between osteoporosis and the development of rotator cuff tears. To investigate whether osteoporosis is associated with an increased risk of rotator cuff tears.

MATERIALS AND METHODS

We conducted a population-based, matched-cohort study with a 7-year follow-uTwo matched cohorts (n = 3511 with osteoporosis and 17,555 without osteoporosis) were recruited from Taiwan's Longitudinal Health Insurance Dataset. Person-year data and incidence rates were evaluated. A multivariable Cox model was used to derive an adjusted hazard ratio (aHR) after controlling for age, sex, and various prespecified comorbidities. Age and sex were added in the model to test for interaction with osteoporosis.

RESULTS

Women constituted 88.5% of the cohorts. During follow-up of 17,067 and 100,501 person-years for the osteoporosis and nonosteoporosis cohorts, 166 and 89 rotator cuff tears occurred, respectively. The cumulative incidence of rotator cuff tears was significantly higher in the osteoporosis cohort than in the nonosteoporosis cohort (p < 0.001, log-rank). The Cox model revealed a 1.79-fold increase in rotator cuff tears in the osteoporosis cohort, with an aHR of 1.79 (95% confidence interval, 1.55-2.05). Effect modification of sex and age on rotator cuff tears was not found in patients with osteoporosis.

CONCLUSION

This population-based study supports the hypothesis that compared with individuals without osteoporosis, those with osteoporosis have a higher risk of developing rotator cuff tears.

The role of vitamin D on rotator cuff tear with osteoporosis

BACKGROUNDS

Osteoporosis (OP) is an important risk factor for rotator cuff tears (RCTs). However, the relationship and mechanism between rotator cuff injury and osteoporosis are unclear. Therefore, to investigate association between rotator cuff injury and osteoporosis, and find clinical characteristics, bone mineral density, bone metabolism markers, and nutrient levels in rotator cuff injury patients with or without osteoporosis.

METHODS

One hundred and four cases of patients (RCTs, n=32; RCTs-OP, n=72) who underwent rotator cuff injury and need arthroscopic rotator cuff repair between June 2021 and February 2022, along with the diagnosis of osteoporosis were identified from the dual-energy X-ray bone density screening(DXA). The outcome measure includes clinical characteristics, bone mineral density, bone metabolism markers, vitamins, and amino acids. Multivariable logistic regression analysis was applied to build a predicting model incorporating the feature selected in the least absolute shrinkage and selection operator regression model. Discrimination, calibration, and clinical usefulness of the predicting model were assessed using the C-index, calibration plot, and decision curve analysis. Internal validation was assessed using bootstrapping validation.

RESULTS

OP with RCTs has a lower level of in 25-vitD, osteocalcin (OCN), serum Ca2+, ornithine, diaminocaproic_acid but the high level of Vitamin_B12, PTH, Vitamin_D3,γ_aminobutyric_acid, Vitamin_C and Vitamin_E than RCTs patients without OP. Predictors contained in the prediction nomogram included lumber T score, femur T score, Niacin_B3, and vitamin D, reflecting the combined effect of vitamins on RCTs-related OP progression. The model has good discriminative ability with a C-index of 0.938(95% CI:-1.83-1.39) and good scaling ability. The high C-index value of 0.95 is still achievable with range validation. Analysis of decision curves showed that non-adherence is clinically useful when intervention decisions are at the 14% probability limit of non-adherence.

CONCLUSION

This study supports the hypothesis that lumber T score, femur T score, Niacin_B3, and Vitamin D are valuable prognostic biomarkers on RCTs related OP progression.

WHAT IS KNOWN ABOUT THE SUBJECT

It is found that vitamin D are valuable prognostic biomarkers, reflecting the combined effect of vitamins on RCTs related OP progression.

WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE

These findings also highlight that nutrients condition such as vitamins and amino acids of patients provide a new understanding of the development of RCTs.

Trabecular Bone Score Could Not Predict the Bone Mineral Density of Proximal Humerus

Background

Osteoporosis is an important clinical factor for tendon healing after arthroscopic rotator cuff repair (ARCR). Conventional dual energy X-ray absorptiometry (DXA) of the hip and lumbar spine (LS) does not represent proximal humeral bone mineral density (BMD). Theoretically, direct measurement of the BMD of the proximal humerus is the best method; however, it is not popular and is non-standardized. Therefore, we evaluate whether the trabecular bone score (TBS) using LS DXA would represent proximal humeral BMD.

Methods

Conventional hip and LS DXA and proximal humeral BMD were measured in 212 consecutive ARCR patients, and TBS was calculated using LS DXA. Comparative analysis between the affected and contralateral asymptomatic shoulders was done; moreover, correlation analysis was conducted to evaluate the representativity of TBS for proximal humeral BMD. Regression analysis was performed to elucidate the risk factor of intraoperative suture anchor failure (ISAF).

Results

BMDs of the affected shoulder were significantly lower than those of the contralateral side (all P<0.05). TBS failed to present a strong correlation with proximal humeral BMD (correlation coefficients 0.155–0.506, all P<0.05), and the BMD of the greater tuberosity (GT) of the proximal humerus was revealed to be a sole risk factor for ISAF (odds ratio, 0.01, P=0.020).

Conclusions

TBS and conventional hip and LS DXA did not represent proximal humeral BMD. Furthermore, among the various radiological measurements, the BMD of the GT was a sole risk factor of ISAF. Therefore, further research for the direct measurement of proximal humeral BMD is mandatory to predict proximal humeral focal osteoporosis.

Greater Tuberosity Bone Mineral Density and Rotator Cuff Tear Size Are Independent Factors Associated With Cutting-Through in Arthroscopic Suture-Bridge Rotator Cuff Repair

PURPOSE

To evaluate the correlation between cutting-through at the greater tuberosity (GT) in arthroscopic suture-bridge rotator cuff repair and the bone mineral density (BMD) of the lumbar spine, hip, and ipsilateral GT of the proximal humerus and to evaluate factors and clinical outcomes related to cutting-through.

METHODS

This study prospectively enrolled patients who underwent arthroscopic knotted suture-bridge rotator cuff repair for full-thickness rotator cuff tears between June 2014 and October 2015 and who had undergone dual-energy X-ray absorptiometry cans within 1 month before surgery with a minimum 2-year follow-up. Cutting-through was defined as the occurrence of cortical breakage of the GT just medial to the lateral knotless anchor hole due to the tension of the sutures from the medial anchor, and it was assessed. Clinical and radiologic data were analyzed. Univariate and regression analyses were performed to evaluate factors related to cutting-through.

RESULTS

A total of 78 patients were analyzed. Patients were divided into 2 groups: patients who had cutting-through (46, group I) and patients who did not (32, group II). In an analysis of lumbar spine, hip, and GT BMD, GT BMD was the most effective for predicting cutting-through (area under the receiver operating characteristic curve = 0.94, 95% confidence interval 0.89-0.99). GT BMD (P < .001) and tear size (P = .004) were independent factors for cutting-through. Although a significant difference was found between the 2 groups in terms of age, sex, lumbar spine and hip BMD, fatty infiltration of the supraspinatus and infraspinatus, and atrophy of the supraspinatus, these variables were not independent factors. Clinical and structural outcomes showed no significant difference between the 2 groups, and anchor failure was not identified intraoperatively.

CONCLUSIONS

GT BMD and rotator cuff tear size are independent factors associated with cutting-through at the GT. A dual-energy X-ray absorptiometry scan of the proximal humerus is useful for predicting bone quality before arthroscopic suture-bridge rotator cuff repair.

LEVEL OF EVIDENCE

Level II, Prospective cohort study.

Osteoporosis Screening Is Often Indicated but Overlooked Prior to Rotator Cuff Repair

Purpose

To (1) report the percentage of patients undergoing rotator cuff repair (RCR) who were appropriately screened with dual-energy X-ray absorptiometry testing prior to surgery, if indicated, and (2) determine the percentage of patients properly prescribed osteoporosis medications within 6 months of surgery.

Methods

Consecutive patients aged 50 years or older who underwent elective RCR at a single tertiary-care center over a 1-year period were reviewed. Fracture risk was estimated using the Fracture Risk Assessment Tool (FRAX) with and without bone mineral density. The U.S. National Osteoporosis Foundation (NOF) criteria for screening and treatment were applied. Patients with acute fractures or revision surgery were excluded.

Results

Of the 218 patients included, 129 were women (58.1%). The mean age was 61.5 ± 7.2 years. One hundred thirty-one RCRs (60.1%) occurred within 3 months of injury. A total of 69 patients (31.7%) met the NOF criteria for bone mineral density screening. Of these patients, 23 (33.3%) were appropriately screened with a dual-energy X-ray absorptiometry scan. Primary care providers initiated bone health assessment in 18 of the 23 appropriately screened patients, with orthopaedic providers initiating the workup in 3 patients (13.0%). Thirty-two patients (14.7%) met the NOF criteria for pharmacologic management of osteoporosis. Of these patients, 5 (15.6%) were treated. Patients meeting the medication criteria were older (69.1 ± 7.7 years vs 60.2 ± 6.3 years, P < .001), had a lower body mass index (28.8 ± 6.1 vs 31.5 ± 6.5, P = .028), and had chronic rotator cuff tears (P = .015).

Conclusions

Patients aged 50 years or older undergoing RCR are often not appropriately screened for osteoporosis. Even when appropriately screened, only 15.6% of patients meeting the indications for pharmacologic intervention for bone health optimization were prescribed appropriate medications. Although bone health optimization may or may not affect surgical timing, patient encounters related to rotator cuff tears can be used as an opportunity for providers to initiate osteoporosis screening and treatment protocols.

Level of Evidence

Level IV, therapeutic case series.

Reconstruction of proximal humeral fractures without screws using a reinforced bone substitute

Multi-fragment fractures are still a challenge: current clinical practice relies on plates and screws. Treatment of fractures of the proximal humerus has the intra-operative risk of articular damage when inserting multiple screws. Distal-varus collapse of the head is a frequent complication in osteoporotic patients. The aim of this biomechanical study was to investigate if an Innovative-cement-technique (the screws are replaced by injection of cement) provides the same or better stability of the reconstructed head compared to the Standard-technique (locking screws). A four-fragment fracture was simulated in twelve pairs of humeri, with removal of part of the cancellous bone to simulate osteoporotic "eggshell" defect. One humerus of each pair was repaired either with a Standard-technique (locking plate, 2 cortical and 6 locking screws), or with the Innovative-cement-technique (injection of a partially-resorbable reinforced bone substitute consisting of PMMA additivated with 26% beta-TCP). Cement injection was performed both in the lab and under fluoroscopic monitoring. The reconstructed specimens were tested to failure with a cyclic force of increasing amplitude. The Innovative-cement-technique withstood a force 3.57 times larger than the contralateral Standard reconstructions before failure started. The maximum force before final collapse for the Innovative-cement-technique was 3.56 times larger than the contralateral Standard-technique. These differences were statistically significant. The Innovative-cement-technique, based on the reinforced bone substitute, demonstrated better biomechanical properties compared to the Standard-technique. These findings, along with the advantage of avoiding the possible complications associated with the locking screws, may help safer and more effective treatment in case of osteoporotic multi-fragment humeral fractures.

[Surgical treatment of complex fractures of the upper end of the humerus: a retrospective study of 25 cases]

Les fractures de l’extrémité supérieure de l’humérus posent un problème thérapeutique particulièrement pour les fractures complexes à 3 et 4 fragments. Le but de notre travail est de déterminer l’aspect épidémio-clinique des fractures complexes de l’extrémité supérieure de l’humérus chez l’adulte et d’apprécier les résultats fonctionnels et radiologiques de notre série. Il s’agit d’une série de 25 cas colligés au service d’orthopédie CHU Habib Bourguiba entre 2012 et 2017. Nous avons recensé les données épidémiologiques des patients et les circonstances du traumatisme. Le traitement était de principe chirurgical soit ostéosynthèse par plaque ou clou soit un remplacement prothétique. La réduction a été évaluée sur les radiographies post opératoires. Au recul les résultats fonctionnels ont été évalués par le score de Constant. Notre série comporte 12 hommes et 13 femmes, La moyenne d’âge de nos patients était 55 ans, les accidents de la voie publique étaient notés dans 48%, Les fractures à 4 fragments ont été retrouvées dans 76% des cas. L’ostéosynthèse par plaque vissée a été utilisée dans 40% des cas et l’enclouage antérograde a été réalisé dans 40% des cas. La prothèse a été posée pour 5 patients. Le score de constant moyen était de 65,24 avec des extrêmes allant de 35 à 88. Nous avons noté une consolidation des fractures sans cal vicieux dans 68%. Dans les fractures complexes de l’extrémité supérieure de l’humérus, une ostéosynthèse bien indiquée selon le patient et la fracture et une rééducation post opératoire précoce permettent d’avoir des résultats fonctionnels acceptables.

Intratendinous Injection of Mesenchymal Stem Cells for the Treatment of Rotator Cuff Disease: A 2-Year Follow-Up Study

PURPOSE

To assess the mid-term safety and efficacy of an intratendinous injection of autologous adipose tissue-derived mesenchymal stem cells (AD MSCs) for rotator cuff disease at 2-year follow-up.

METHODS

The first part of the study consisted of 3 dose-escalation groups, with 3 patients each, for the evaluation of safety: low-dose (1.0 × 10⁷ cells), mid-dose (5.0 × 10⁷), and high-dose (1.0 × 10⁸) groups. For the second part, we planned to include 9 patients receiving the high dose for the evaluation of exploratory efficacy. Clinical outcomes were assessed according to pain, range of motion, muscle strength, functional scores, overall satisfaction and function, and presence of failure. Structural outcomes included changes in volume of tendon defects measured using magnetic resonance imaging.

RESULTS

This study enrolled 19 patients (9 for the first part and 10 for the second part) with partial-thickness rotator cuff tears. There were no treatment-related adverse events at minimum 2-year follow-up. Intratendinous injection of AD MSCs reduced shoulder pain by approximately 90% at 1 and 2 years in the mid- and high-dose groups. The strength of the supraspinatus, infraspinatus, and teres minor significantly increased by greater than 50% at 2 years in the high-dose group. Shoulder function measured with 6 commonly used scores improved for up to 2 years in all dose groups. Structural outcomes evaluated with magnetic resonance imaging showed that the volume of bursal-sided defects in the high-dose group nearly disappeared at 1 year and did not recur at up to 2 years. No failures-defined as the performance of any kind of shoulder surgery or return of the Shoulder Pain and Disability Index score to the preinjection level-occurred during follow-up.

CONCLUSIONS

This study showed continued safety and efficacy of an intratendinous injection of AD MSCs for the treatment of partial-thickness rotator cuff tears over a 2-year period through regeneration of tendon defects.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

In vitro effects of alendronate on fibroblasts of the human rotator cuff tendon

Background

Bone mineral density of the humeral head is an independent determining factor for postoperative rotator cuff tendon healing. Bisphosphonates, which are commonly used to treat osteoporosis, have raised concerns regarding their relationships to osteonecrosis of the jaw and to atypical fracture of the femur. In view of the prevalence of rotator cuff tear in osteoporotic elderly people, it is important to determine whether bisphosphonates affect rotator cuff tendon healing. However, no studies have investigated bisphosphonates’ cytotoxicity to human rotator cuff tendon fibroblasts (HRFs) or bisphosphonates’ effects on rotator cuff tendon healing. The purpose of this study was to evaluate the cytotoxicity of alendronate (Ald), a bisphosphonate, and its effects on HRF wound healing.

Methods

HRFs were obtained from human supraspinatus tendons, using primary cell cultures. The experimental groups were control, 0.1 μM Ald, 1 μM Ald, 10 μM Ald, and 100 μM Ald. Alendronate exposure was for 48 h, except during a cell viability analysis with durations from 1 day to 6 days. The experimental groups were evaluated for cell viability, cell cycle and cell proliferation, type of cell death, caspase activity, and wound-healing ability.

Results

The following findings regarding the 100 μM Ald group contrasted with those for all the other experimental groups: a significantly lower rate of live cells (p < 0.01), a higher rate of subG1 population, a lower rate of Ki-67 positive cells, higher rates of apoptosis and necrosis, a higher number of cells with DNA fragmentation, higher caspase-3/7 activity (p < 0.001), and a higher number of caspase-3 positive staining cells. In scratch-wound healing analyses of all the experimental groups, all the wounds healed within 48 h, except in the 100 μM Ald group (p < 0.001).

Conclusions

Low concentrations of alendronate appear to have little effect on HRF viability, proliferation, migration, and wound healing. However, high concentrations are significantly cytotoxic, impairing cellular proliferation, cellular migration, and wound healing in vitro.

All-Suture Anchor Settling After Arthroscopic Repair of Small and Medium Rotator Cuff Tears

BACKGROUND

All-suture anchors are increasingly being used in rotator cuff repair. However, there are debates on the micromotion of all-suture anchors.

PURPOSE

To perform rotator cuff repair on patients with rotator cuff tears and different shoulder bone mineral densities (BMDs) and investigate (1) where the anchor is located under the cortex, (2) if there is any anchor migration settling during follow-up, and (3) if structural outcome differs according to shoulder BMD.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We retrospectively investigated 88 patients who underwent arthroscopic single-row repair for small- to medium-sized rotator cuff tears (age [mean ± SD], 58.8 ± 7.1 years) from 712 cases of rotator cuff tendon repair between November 2015 and February 2018. Inclusion criteria were as follows: use of an all-suture anchor; preoperative shoulder BMD; and magnetic resonance imaging (MRI) conducted preoperatively, 2 days after surgery, and 10 months after surgery. Patients were excluded from the study if they underwent open rotator cuff repair (n = 118), got surgery with a double-row technique (n = 178), underwent surgery with anchors other than the all-suture type (n = 273), received anchor insertion in sites other than the greater tuberosity owing to concomitant procedures such as biceps tenodesis and subscapularis repair (n = 29), did not take preoperative shoulder BMD (n = 15), had more than a large-size tear (n = 6), and were lost to follow-up (n = 5). After compression of the all-suture anchor during surgery, the strands were pulled multiple times to ensure that the anchor was fixed onto the bone with appropriate tension. BMD was measured before surgery. Depth to anchor (DA), anchor settling, and repaired rotator cuff integrity were measured with MRI. Patients were categorized into 3 groups: group A (BMD, <0.4 g/cm²; n = 31), group B (BMD, 0.4-0.6 g/cm²; n = 32), and group C (BMD, >0.6 g/cm²; n = 25). A total of 65 patients had follow-up MRI. On the basis of rotator cuff tendon integrity, patients were categorized into either a sufficient thickness group (group S, Sugaya classification grade II or lower; n = 44) or an insufficient thickness group (group I, Sugaya classification grade III or higher; n = 21).

RESULTS

On time-zero MRI, the DA differed significantly among groups (group A, 3.62 ± 2.02 mm; group B, 5.18 ± 2.13 mm; group C, 6.30 ± 3.34 mm) (P = .001). The DA was deeper in patients with a higher BMD at time zero (r = 0.374; P = .001), but the DA did not differ at follow-up MRI (mean, 10.3 months after surgery). On follow-up MRI, anchor settling tended to increase with deeper time-zero DA (r = 0.769; P < .001). Anchor settling was significantly different among groups (group A, 1.33 ± 1.08 mm; group B, 2.78 ± 1.99 mm; group C, 3.81 ± 2.19 mm) (P = .001). The proportion of patients with sufficient thickness in each group did not show a statistical difference (group A, 70.8%; group B, 72.7%; group C, 57.9%) (P = .550).

CONCLUSION

In conclusion, this study confirmed that the postoperative site of anchor insertion in arthroscopic single-row rotator cuff repair with all-suture anchors was located farther from the cortex in patients with higher shoulder BMD and closer to the subcortical bone in patients with lower BMD. On follow-up MRI, no further settling occurred past a certain distance from the cortex, and there was no significant difference in anchor depth or integrity of the rotator cuff tendon based on shoulder BMD. Therefore, minimal settling in the all-suture anchor did not show clinical significance.

Impact of Diaphyseal Cortical Thickness on Functional Outcomes After Arthroscopic Rotator Cuff Repair

PURPOSE

To study the influence of combined cortical thickness (CCT) of the proximal humerus on arthroscopic rotator cuff tear repair outcomes.

METHODS

The study included 210 patients who underwent arthroscopic repair of full-thickness supraspinatus tears. An independent reviewer measured CCT on preoperative radiographs, and patients were evaluated postoperatively at 3, 6, 12, and 24 months. Functional outcome was assessed with the Constant shoulder score (CSS), Oxford shoulder score (OSS), and University of California at Los Angeles Shoulder rating scale (UCLASS). The patients were divided based on CCT: ≥4 mm (higher CCT) and <4 mm (lower CCT). Univariate analysis and multivariate linear regressions were applied to study the effect of higher CCT on functional scores.

RESULTS

At 6 months' follow-up, CSS and UCLASS were higher in the patients with higher CCT (mean ± standard deviation, 59 ± 17 vs 54 ± 14, P = .020; and 30 ± 5 vs 28 ± 5, P = .020, respectively). At 12 months' follow-up, CSS, UCLASS, and OSS were higher in the patients with higher CCT (71 ± 13 vs 65 ± 14, P = .002; 30 ± 5 vs 28 ± 5, P = .009; and 15 ± 6 vs 18 ± 7, P = .001, respectively). At 24 months' follow-up, CSS and OSS were higher in the patients with higher CCT (74 ± 11 vs 69 ± 13, P = .006; and 14 ± 4 vs 16 ± 8, P = .041, respectively).

CONCLUSION

We conclude that although a higher CCT is not associated with clinically significant differences in functional outcomes, further studies examining postoperative imaging as well as perioperative optimization of bone mineral density may yield valuable results regarding the impact of CCT on cuff healing and functional outcomes.

LEVEL OF EVIDENCE

III (retrospective comparative therapeutic trial).

The Association of Osteoporosis and Bisphosphonate Use With Revision Shoulder Surgery After Rotator Cuff Repair

PURPOSE

To examine any association between osteoporosis and the failure of arthroscopic rotator cuff repair (ARCR) leading to revision surgery and to investigate whether the use of bisphosphonates had any influence on the observed associations.

METHODS

Patients who underwent ARCR with a diagnosis of osteoporosis were identified from the PearlDiver database and stratified according to whether there was a filled prescription for a bisphosphonate in the perioperative period. Patients with osteoporosis who underwent ARCR with bisphosphonate use were compared with age- and sex-matched patients who underwent ARCR with osteoporosis without a prescription for a bisphosphonate within 1 year of surgery and patients who underwent ARCR without a diagnosis of osteoporosis and no bisphosphonate use. The primary outcome measure was ipsilateral revision rotator cuff surgery, including revision repair, debridement for a diagnosis of a rotator cuff tear, or reverse shoulder arthroplasty. A multivariable logistic regression analysis was used to control for patient demographic characteristics and comorbidities during comparisons.

RESULTS

We identified 2,706 patients, including 451 in the bisphosphonate study group; 902 in the osteoporosis, no-bisphosphonate control group; and 1,353 in the non-osteoporosis control group. Patients with osteoporosis, including those to whom bisphosphonates were prescribed, had a significantly higher rate of revision rotator cuff surgery (6.58%) than patients without osteoporosis (4.51%) (odds ratio, 1.60; 95% confidence interval, 1.30-1.97; P = .008). No significant difference in the rate of revision surgery was found between patients with osteoporosis using bisphosphonates (6.65%) and age- and sex-matched patients with osteoporosis not using bisphosphonates (6.54%, P = .718).

CONCLUSIONS

By using an administrative database, this study was able to show a substantial difference in the revision surgery rate after ARCR in patients with osteoporosis compared with matched controls.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Adaptation of the proximal humerus to physical activity: A within-subject controlled study in baseball players

The proximal humerus is a common, yet understudied site for osteoporotic fracture. The current study explored the impact of prolonged physical activity on proximal humerus bone health by comparing bone properties between the throwing and nonthrowing arms within professional baseball players. The proximal humerus in throwing arms had 28.1% (95% CI, 17.8 to 38.3%) greater bone mass compared to nonthrowing arms, as assessed using dual-energy x-ray absorptiometry. At the level of the surgical neck, computed tomography revealed 12.0% (95% CI, 8.2 to 15.8%) greater total cross-sectional area and 31.0% (95% CI, 17.8 to 44.2%) greater cortical thickness within throwing arms, which contributed to 56.8% (95% CI, 44.9 to 68.8%) greater polar moment of inertia (i.e., estimated ability to resist torsional forces) compared to nonthrowing arms. Within the humeral head and greater tubercle regions, throwing arms had 3.1% (95% CI, 1.1 to 5.1%) more trabecular bone, as assessed using high-resolution magnetic resonance imaging. Three-dimensional mapping of voxel- and vertex-wise differences between arms using statistical parametric mapping techniques revealed throwing arms had adaptation within much of the proximal diaphysis, especially the posterolateral cortex. The pattern of proximal diaphysis adaptation approximated the pattern of strain energy distribution within the proximal humerus during a fastball pitch derived from a musculoskeletal and finite element model in a representative player. These data demonstrate the adaptive ability of the proximal humerus to physical activity-related mechanical loads. It remains to be established how they translate to exercise prescription to improve bone health within the proximal humerus; however, they provide unique insight into the relationship between prolonged loading and skeletal adaptation at a clinically relevant osteoporotic site.

Surgical Considerations in Managing Osteoporosis, Osteopenia, and Vitamin D Deficiency During Arthroscopic Rotator Cuff Repair

Osteopenia and osteoporosis are common in older adults and are associated with increased risk of fragility fractures. Vitamin D deficiency caused by chronic disease, poor nutrition, and inadequate sun exposure affects bone quality. Chronic rotator cuff tears can deteriorate the bone mineral density of the greater tuberosity and have been linked to reduced anchor pullout strength and high re-tear rate after repair especially in older patients with larger tear size. This article summarizes the current evidence on rotator cuff tear and bone quality and provides treatment strategies for rotator cuff repair in patients with poor bone quality.

Effects of Estrogen-Deficient State on Rotator Cuff Healing

BACKGROUND

Rotator cuff retears after surgical repair are a concern, despite advances in operative techniques, but few studies have investigated the effects of the estrogen-deficient state on tendon-to-bone healing at the repair site.

PURPOSE

We evaluated the effect of the estrogen-deficient state on tendon-to-bone healing after rotator cuff repair in an ovariectomized rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Female Sprague Dawley rats underwent detachment and immediate repair of the supraspinatus tendon. Surgery was performed in 24 rats at 4.5 weeks of age 17 weeks after ovariectomy (OVX group) and in 24 age-matched control rats without ovariectomy (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks after surgery for biomechanical and histological evaluations of reattachment. Bone mineral density (BMD) at the insertion site and cancellous bone in the humeral head was assessed by micro-computed tomography.

RESULTS

BMD was significantly lower both at the insertion site and in cancellous area in the OVX group than in the control group at weeks 2 to 12. Ultimate load to failure, ultimate stress, linear stiffness, and the Young modulus were significantly lower in the OVX group than in the control group at 2 and 4 weeks, but the difference was no longer significant at 8 and 12 weeks. At 2 and 4 weeks, relatively immature granulation tissue was observed in the OVX group compared with the control group. At 8 and 12 weeks after surgery, there were differences in the tendon-bone interface in the 2 groups: Direct insertion with well-established chondroid tissue was seen in the control group, and indirect insertion without chondroid tissue was seen in the OVX group. Consistently, the amount of chondroid tissue was greater and collagen organization was better in the control group than in the OVX group. Cells expressing cathepsin K were significantly more numerous both at the insertion site and in cancellous bone in the OVX group than in the control group.

CONCLUSION

The estrogen-deficient state by ovariectomy, compared with control rats, led to decreased biomechanical properties and poor development of chondroid tissue that influenced the repair of the tendon insertion after surgery.

CLINICAL RELEVANCE

Agents that modulate bone metabolism might improve tendon-to-bone healing in patients with an estrogen-deficient state, such as postmenopausal women who undergo rotator cuff surgery.

Humeral bone resorption after anatomic shoulder arthroplasty using an uncemented stem

BACKGROUND

Bone resorption around the femoral stem after total hip arthroplasty is a well-known phenomenon. However, only a few studies have evaluated bone resorption after shoulder arthroplasty. This study investigated the prevalence of humeral bone resorption after different shoulder arthroplasty procedures.

METHODS

The study included 147 shoulders that underwent total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with an uncemented humeral stem from November 2008 to May 2015 and were monitored for more than 1 year. The prevalence of humeral bone resorption and risk factors were investigated.

RESULTS

The most advanced grade of bone resorption, grade 0, occurred in 21 shoulders (14.3%). Grade 1 bone resorption occurred in 10 (6.8%), grade 2 in 28 (19.0%), grade 3 in 61 (41.5%), and grade 4 in 27 (18.4%). High occurrence of bone absorption was observed in zones 1, 2, and 7. Grade 4 bone resorption did not occur in zones 3 and 5. HHR, on-growth type stem coating, and occupation ratio were significant independent risk factors for grade ≥3 bone resorption, whereas female sex and HHR were significant independent risk factors for grade 4.

CONCLUSION

Bone resorption was observed in 126 shoulders (85.7%), and full-thickness cortical bone resorption occurred in 27 shoulders (18.4%). Bone resorption was frequently observed at the greater tuberosity, lateral diaphysis, and calcar region (zones 1, 2, and 7). Significant risk factors included female sex, HHR with rotator cuff reconstruction, on-growth type stem coating, and high occupation ratio of the implant.

Supraspinatus detachment causes musculotendinous degeneration and a reduction in bone mineral density at the enthesis in a rat model of chronic rotator cuff degeneration

BACKGROUND

To evaluate biological strategies that enhance tendon-bone healing in humans, it is imperative that suitable animal models accurately reproduce the pathological changes observed in the clinical setting following a tear. The purpose of the present study was to investigate rotator cuff degeneration in a rat, as well as assess the development of osteopenia at the enthesis following tendon detachment.

METHODS

Eighteen female Wistar rats underwent unilateral detachment of the supraspinatus tendon. Specimens were retrieved at 4 weeks (n = 6), 6 weeks (n = 6) and 9 weeks (n = 6) postoperatively for histological analysis and peripheral quantitative computer tomography.

RESULTS

Three weeks following tendon detachment, there was a significant increase in the modified Movin score, characterized by a loss of muscle mass, fatty infiltration, an increase in musculotendinous cellularity, loss of normal collagen fibre structure/arrangement, rounded tenocyte nuclei and an increase in the number of vascular bundles. This was accompanied by a reduction in bone mineral density at the tendon insertion site. After 3 weeks however, these changes were less prominent.

CONCLUSIONS

The rotator cuff tendon-muscle-bone unit in a rat model 3 weeks after detachment of supraspinatus represents a valid model for investigating rotator cuff degeneration.

Vitamin D and the immunomodulation of rotator cuff injury

Tendon-to-bone healing after rotator cuff repair surgery has a failure rate of 20%–94%. There has been a recent interest to determine the factors that act as determinants between successful and unsuccessful rotator cuff repair. Vitamin D level in patients is one of the factors that have been linked to bone and muscle proliferation and healing, and it may have an effect on tendon-to-bone healing. The purpose of this article is to critically review relevant published research that relates to the effect of vitamin D on rotator cuff tears and subsequent healing. A review of the literature was conducted to identify all studies that investigate the relationship between vitamin D and tendon healing, in addition to its mechanism of action. The data were then analyzed in order to summarize what is currently known about vitamin D, rotator cuff pathology, and tendon-to-bone healing. The activated metabolite of vitamin D, 1α,25-dihydroxyvitamin D₃, affects osteoblast proliferation and differentiation. Likewise, vitamin D plays a significant role in the tendon-to-bone healing process by increasing the bone mineral density and strengthening the skeletal muscles. The 1α,25-dihydroxyvitamin D₃ binds to vitamin D receptors on myocytes to stimulate growth and proliferation. The form of vitamin D produced by the liver, calcifediol, is a key initiator of the myocyte healing process by moving phosphate into myocytes, which improves function and metabolism. Investigation into the effect of vitamin D on tendons has been sparse, but limited studies have been promising. Matrix metalloproteinases play an active role in remodeling the extracellular matrix (ECM) of tendons, particularly deleterious remodeling of the collagen fibers. Also, the levels of transforming growth factor-β3 positively influence the success of the surgery for rotator cuff repair. In the tendon-to-bone healing process, vitamin D has been shown to successfully influence bone and muscle healing, but more research is needed to delve into the mechanisms of vitamin D as a factor in skeletal tendon health and healing.