scholarly journals Clinical Outcomes of Primary versus Revision Surgery using Arthroscopic Anatomic Glenoid Reconstruction for Anterior Shoulder Instability. (244)

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0035
Author(s):  
Ivan Wong ◽  
Ryland Murphy ◽  
Sara Sparavalo ◽  
Jie Ma

Objectives: Revision surgeries after prior shoulder stabilization are known to have worse outcomes as compared to their primary counterparts. To date, no studies have looked at the utility of arthroscopic anatomic glenoid reconstruction (AAGR) as a revision surgery. The purpose of this study was to assess the clinical outcomes of primary versus revision AAGR for anterior shoulder instability with bone loss. Methods: We performed a retrospective review on consecutive patients with prospectively collected data who underwent AAGR from 2012 to 2018. Patients who received AAGR for anterior shoulder instability with bone loss and had a minimum follow-up of two years were included. Exclusion criteria included patients with rotator cuff pathology, multidirectional instability and glenoid fractures. There were 68 patients (48 primary and 20 revision) who met inclusion/exclusion criteria. Our primary outcome was measured using the Western Ontario Shoulder Instability Index (WOSI) and Disabilities of Arm, Shoulder, Hand (DASH) scores. Secondary outcomes included post-operative complications and post-operative recurrent instability. Results: The primary group showed a significant improvement in most-recent post-operative WOSI from 62.7 to 20.7 (P<0.001, α=0.05) and in DASH from 26.89 to 6.7 (p<0.001, α=0.05). The revision group also showed a significant improvement in WOSI from 71.5 to 34.6 (p<0.001, α=0.05) and in DASH from 39.5 to 17.0 (p<0.05, α=0.05). When comparing between groups, the revision group had worse WOSI scores (34.6) at most recent follow-up compared to the primary group (20.7); p<0.05. The most-recent DASH scores also showed the revision group (17.0) having worse outcomes than the primary group (6.7); p<0.05. Important to note that the minimal clinically important difference (MCID) was met for WOSI (MCID=10.4) but not DASH (MCID=10.83). There were no post-operative reports of instability in either group. For complications, one hardware failure (suture anchor) was seen in the primary group, and two hardware removals were seen in the revision group. Conclusions: While patient reported scores indicated worse outcomes in the revision group, the significant clinical improvement in DASH and WOSI, along with the lack of recurrent instability provides evidence that AAGR is a suitable option for revision patients.

2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110075
Author(s):  
Rachel M. Frank ◽  
Hytham S. Salem ◽  
Catherine Richardson ◽  
Michael O’Brien ◽  
Jon M. Newgren ◽  
...  

Background: Nearly all studies describing shoulder stabilization focus on male patients. Little is known regarding the clinical outcomes of female patients undergoing shoulder stabilization, and even less is understood about females with glenoid bone loss. Purpose: To assess the clinical outcomes of female patients with recurrent anterior shoulder instability treated with the Latarjet procedure. Study Design: Case series; Level of evidence, 4. Methods: All cases of female patients who had recurrent anterior shoulder instability with ≥15% anterior glenoid bone loss and underwent the Latarjet procedure were analyzed. Patients were evaluated after a minimum 2-year postoperative period with scores of the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale. Results: Of the 22 patients who met our criteria, 5 (22.7%) were lost to follow-up, leaving 17 (77.2%) available for follow-up with a mean ± SD age of 31.7 ± 12.9 years. Among these patients, 16 (94.1%) underwent 1.6 ± 0.73 ipsilateral shoulder operations (range, 1-3) before undergoing the Latarjet procedure. Preoperative indications for surgery included recurrent instability with bone loss in all cases. After a mean follow-up of 40.2 ± 22.9 months, patients experienced significant score improvements in the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale ( P < .05 for all). There were 2 reoperations (11.8%). There were no cases of neurovascular injuries or other complications. Conclusion: Female patients with recurrent shoulder instability with glenoid bone loss can be successfully treated with the Latarjet procedure, with outcomes similar to those of male patients in the previously published literature. This information can be used to counsel female patients with recurrent instability with significant anterior glenoid bone loss.


2021 ◽  
Vol 9 (10) ◽  
pp. 232596712110302
Author(s):  
Sunita R.P. Mengers ◽  
Derrick M. Knapik ◽  
Matthew W. Kaufman ◽  
Gary Edwards ◽  
James E. Voos ◽  
...  

Background: Few studies have compared clinical outcomes between the traditional Latarjet procedure for anterior shoulder instability and the congruent arc modification to the Latarjet procedure. Purpose: To systematically evaluate the literature for the incidence of recurrent instability, clinical outcomes, radiographic findings, and complications for the traditional Latarjet procedure and the congruent arc modification and to compare results of each search. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review and meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies published between January 1990 and October 2020 that described clinical outcomes of the traditional Latarjet and the congruent arc modification with a follow-up range of 2 to 10 years. The difference in surgical technique was analyzed using a chi-square test for categorical variables, while continuous variables were evaluated using a Student t test. Results: In total, 26 studies met the inclusion criteria: 20 studies describing the traditional Latarjet procedure in 1412 shoulders, and 6 studies describing the congruent arc modification in 289 shoulders. No difference between procedures was found regarding patient age at surgery, follow-up time, Rowe or postoperative visual analog scores, early or late complications, return-to-sport timing, or incidence of improper graft placement or graft fracture. A significantly greater proportion of male patients underwent glenoid augmentation using the congruent arc modification versus traditional Latarjet ( P < .001). When comparing outcomes, the traditional Latarjet procedure demonstrated a lower incidence of fibrous union or nonunion ( P = .047) and broken, loose, or improperly placed screws ( P < .001), and the congruent arc modification demonstrated improved outcomes with regard to overall return to sport ( P < .001), return to sport at the same level ( P < .001), incidence of subluxation ( P = .003) or positive apprehension ( P = .002), and revision surgery for recurrent instability ( P = .027). Conclusion: Outcomes after the congruent arc modification proved at least equivalent to the traditional Latarjet procedure in terms of recurrent instability and return to sport, although early and late complications were equivalent. The congruent arc procedure may be an acceptable alternative to traditional Latarjet for the treatment of anterior shoulder instability with glenoid bone loss; however, long-term outcomes of this procedure are needed.


2007 ◽  
Vol 35 (8) ◽  
pp. 1276-1283 ◽  
Author(s):  
Timothy S. Mologne ◽  
Matthew T. Provencher ◽  
Kyle A. Menzel ◽  
Tyler A. Vachon ◽  
Christopher B. Dewing

Background Recent literature has demonstrated that the success rates of arthroscopic stabilization of glenohumeral instability deteriorate in patients with an anteroinferior glenoid bone deficiency, also known as the “inverted pear” glenoid. Purpose This study was conducted to assess the outcomes of arthroscopic stabilization for recurrent anterior shoulder instability in patients with a mean anteroinferior glenoid bone deficiency of 25% (range, 20%-30%). Study Design Cohort study; Level of evidence, 3. Methods Twenty-one of 23 patients (91% follow-up) undergoing arthroscopic stabilization surgery and noted to have a bony deficiency of the anteroinferior glenoid of 20% to 30% were reviewed at a mean follow-up of 34 months (range, 26-47). The mean age was 25 years (range, 20-34); 2 patients were female and 19 were male. All patients were treated with a primary anterior arthroscopic stabilization using a mean of 3.2 suture anchors (range, 3-4). Eleven patients had a bony Bankart that was incorporated into the repair; 10 had no bone fragment and were considered attritional bone loss. Outcomes were assessed using the Rowe score, the American Shoulder and Elbow Surgeons (ASES) Score, the Single Assessment Numeric Evaluation (SANE), and the Western Ontario Shoulder Instability (WOSI) Index. Findings of recurrent instability and dislocation events were documented. Results Two patients (9.5%) experienced symptoms of recurrent subluxation, and 1 (4.8%) sustained a recurrent dislocation that required revision open surgery. The mean postoperative outcomes scores were as follows SANE = 88.1 (range, 65-100; standard deviation [SD] 9.0); Rowe = 85.2 (range, 55-100; SD 14.1); ASES Score = 93.1 (range, 78-100; SD 5.3); and WOSI Index = 398 (82% of normal; range, 30-1175; SD 264). No patient with a bony fragment experienced a recurrent subluxation or dislocation, and mean outcomes scores for patients with a bony fragment were better than those with no bony fragment (P = .08). No patient required medical discharge from the military for his or her shoulder condition. Conclusions Arthroscopic stabilization for recurrent instability, even in the presence of a significant bony defect of the glenoid, can yield a stable shoulder; however, outcomes are not as predictable especially in attritional bone loss cases. Longer-term follow-up is needed to see if these results hold up over time.


2020 ◽  
Vol 48 (13) ◽  
pp. 3316-3321
Author(s):  
Ivan Wong ◽  
Rakesh John ◽  
Jie Ma ◽  
Catherine M. Coady

Background: The all-arthroscopic anatomic glenoid reconstruction technique using a distal tibial allograft avoids damage to the subscapularis muscle and allows repair of the capsulolabral tissue. Purpose: To analyze the clinicoradiologic outcomes of patients who underwent this procedure to treat anterior shoulder instability with glenoid bone loss with a minimum 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: Over 6 years, 73 patients (52 male and 21 female; mean age, 28.8 years) under the care of the same surgeon underwent arthroscopic stabilization with capsulolabral Bankart repair and bony allograft augmentation of the glenoid for recurrent shoulder instability with significant bone loss. Pre- and postoperative patient-reported functional assessment was performed using 2 questionnaires, the Western Ontario Shoulder Instability Index (WOSI) and the Disabilities of the Arm, Shoulder and Hand, and radiological assessment was performed using radiographs and computed tomography scans obtained preoperatively and approximately 1 year later (mean ± SD, 0.9 ± 1.1 years). Results: The mean follow-up was 4.7 ± 1.1 years. The mean pre- and postoperative WOSI scores were 71.1 ± 17.5 and 25.6 ± 21.9, respectively ( P < .001). There were no recurrences of dislocation, although 1 patient had symptoms of subluxation; however, 5 patients had hardware complications that required screw removal. There were no cases of nerve injury. Postoperative computed tomography scans were available for 66 patients. Seven patients were lost to follow-up. The graft union rate was 100%. Overall, graft resorption was <50% in 86% of patients (57/66). Eighteen patients (27%) had no resorption (grade 0), 39 (59%) had <50% (grades 1 and 2), and 9 (14%) had ≥50% (grade 3); however, none had symptoms of instability. The mean alpha angle of the screw between the screw shaft axis and the native glenoid axis was 18.3°± 5.7°. Graft positioning was flush with the glenoid in 61 of 66 patients (92.4%), and vertical positioning was excellent in 64 of 66 patients (97.0%) (3- to 5-o’clock position). Conclusion: Arthroscopic stabilization using distal tibial allograft augmentation resulted in excellent clinicoradiologic outcomes at a 2-year follow-up. This procedure has the advantages of being an anatomic reconstruction that addresses bony and soft tissue instability. However, long-term follow-up studies are necessary for better assessment of outcomes.


2019 ◽  
Vol 47 (12) ◽  
pp. 2795-2802 ◽  
Author(s):  
Matthew T. Provencher ◽  
Liam A. Peebles ◽  
Zachary S. Aman ◽  
Andrew S. Bernhardson ◽  
Colin P. Murphy ◽  
...  

Background: Patients with recurrent anterior glenohumeral instability after a failed Latarjet procedure remain a challenge to address. Complications related to this procedure include large amounts of bone loss, bone resorption, and issues with retained hardware that necessitate the need for revision surgery. Purpose: To determine the outcomes of patients who underwent revision surgery for a recurrent shoulder instability after a failed Latarjet procedure with fresh distal tibial allograft. Study Design: Case series; Level of evidence, 4. Methods: All consecutive patients who underwent revision of a failed Latarjet procedure with distal tibial allograft were prospectively enrolled. Patients were included if they had physical examination findings consistent with recurrent anterior shoulder instability. Patients were excluded if they had prior neurologic injury, a seizure disorder, bone graft requirements to the humeral head, or findings of multidirectional or posterior instability. History of shoulder instability was documented, including initial dislocation history, duration of instability, number of prior surgeries, examination findings, plain radiographic and computed tomography (CT) data, and arthritis graded with Samilson and Prieto (SP) classification. All patients were treated with hardware removal, capsular release with subsequent repair, and fresh distal tibial allograft to the glenoid. Outcomes before and after revision were assessed according to the American Shoulder and Elbow Score (ASES), Single Assessment Numerical Evaluation (SANE), and Western Ontario Shoulder Index (WOSI) and statistically compared. All patients underwent a CT scan of the distal tibial allograft at a minimum 4 months after surgery. Results: There were 31 patients enrolled (all males), with a mean age of 25.5 years (range, 19-38 years) and a mean follow-up time of 47 months (range, 36-60 months) after revision with distal tibial allograft. Before distal tibial allograft augmentation, the mean percentage glenoid bone loss was 30.3% (range, 25%-49%). All patients after their Latarjet stabilization had recurrent shoulder dislocation (11/31, 35.5%) or subluxation (20/31, 64.5%), and all patients had symptoms consistent with recurrent shoulder instability upon physical examination. Radiographs demonstrated 2 fixation screws in all cases, mean SP grade was 0.5 (range, 0-3), and CT scans revealed that a mean 78% of the Latarjet coracoid graft had resorbed (range, 37%-100%). Patient-reported outcome scores improved significantly pre- to postoperatively for ASES (40 to 92, P = .001), SANE (44 to 91, P = .001), and WOSI (1300 to 310, P = .001). There were no cases of recurrence, and a final CT scan of the distal tibial revision demonstrated a complete union at the glenoid–distal tibial allograft interface in 92% of patients. Conclusion: The majority of the failed Latarjet procedures included in this study had near-complete resorption of the coracoid graft and hardware complications. At a minimum follow-up time of 36 months, patients who underwent revision treatment for a failed Latarjet procedure with a fresh distal tibial allograft demonstrated excellent clinical outcomes and near-complete osseous union at the glenoid-allograft interface. Although patients evaluated with recurrent anterior shoulder instability after a failed Latarjet procedure remain a challenge to address, fresh distal tibial allograft augmentation is a viable and highly effective revision procedure to treat this patient population.


2021 ◽  
pp. 036354652110591
Author(s):  
Ryan R. Wilbur ◽  
Matthew B. Shirley ◽  
Richard F. Nauert ◽  
Matthew D. LaPrade ◽  
Kelechi R. Okoroha ◽  
...  

Background: Athletes of all sports often have shoulder instability, most commonly as anterior shoulder instability (ASI). For overhead athletes (OHAs) and those participating in throwing sports, clinical and surgical decision making can be difficult owing to a lack of long-term outcome studies in this population of athletes. Purpose/Hypothesis: To report presentation characteristics, pathology, treatment strategies, and outcomes of ASI in OHAs and throwers in a geographic cohort. We hypothesized that OHAs and throwers would have similar presenting characteristics, management strategies, and clinical outcomes but lower rates of return to play (RTP) when compared with non-OHAs (NOHAs) and nonthrowers, respectively. Study Design: Cohort study; Level of evidence, 3. Methods: An established geographic medical record system was used to identify OHAs diagnosed with ASI in the dominant shoulder. An overall 57 OHAs with ASI were matched 1:2 with 114 NOHAs with ASI. Of the OHAs, 40 were throwers. Sports considered overhead were volleyball, swimming, racquet sports, baseball, and softball, while baseball and softball composed the thrower subgroup. Records were reviewed for patient characteristics, type of sport, imaging findings, treatment strategies, and surgical details. Patients were contacted to collect Western Ontario Shoulder Instability index (WOSI) scores and RTP data. Statistical analysis compared throwers with nonthrowers and OHAs with NOHAs. Results: Four patients, 3 NOHAs and 1 thrower, were lost to follow-up at 6 months. Clinical follow-up for the remaining 167 patients (98%) was 11.9 ± 7.2 years (mean ± SD). Of the 171 patients included, an overall 41 (36%) NOHAs, 29 (51%) OHAs, and 22 (55%) throwers were able to be contacted for WOSI scores and RTP data. OHAs were more likely to initially present with subluxations (56%; P = .030). NOHAs were more likely to have dislocations (80%; P = .018). The number of instability events at presentation was similar. OHAs were more likely to undergo initial operative management. Differences in rates of recurrent instability were not significant after initial nonoperative management (NOHAs, 37.1% vs OHAs, 28.6% [ P = .331] and throwers, 21.2% [ P = .094]) and surgery (NOHAs, 20.5% vs OHAs, 13.0% [ P = .516] and throwers, 9.1% [ P = .662]). Rates of revision surgery were similar (NOHAs, 18.0% vs OHAs, 8.7% [ P = .464] and throwers, 18.2% [ P > .999]). RTP rates were 80.5% in NOHAs, as compared with 71.4% in OHAs ( P = .381) and 63.6% in throwers ( P = .143). Median WOSI scores were 40 for NOHAs, as compared with 28 in OHAs ( P = .425) and 28 in throwers ( P = .615). Conclusion: In a 1:2 matched comparison of general population athletes, throwers and OHAs were more likely to have more subtle instability, as evidenced by higher rates of subluxations rather than frank dislocations, when compared with NOHAs. Despite differences in presentation and the unique sport demands of OHAs, rates of recurrent instability and revision surgery were similar across groups. Similar outcomes in terms of RTP, level of RTP, and WOSI scores were achieved for OHAs and NOHAs, but these results must be interpreted with caution given the limited sample size.


2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0017
Author(s):  
Anthony C. Egger ◽  
Sam Broida ◽  
S. Clifton Willimon ◽  
Thomas Austin ◽  
Crystal A. Perkins

INTRODUCTION: The treatment of adolescent shoulder instability can be a challenging problem, with multiple patient and radiographic risk factors for recurrent instability. Although glenoid bone loss has been well described, humeral bone loss has gained more recent attention. The purpose of this study is to evaluate the incidence and clinical outcomes of “off track” shoulder lesions and their association with clinical outcomes. METHODS: A retrospective IRB approved study was performed to identify patients less than 19 years of age treated with isolated arthroscopic anterior labral repair for unidirectional shoulder instability. Radiographic measurements of glenoid diameter, % glenoid bone loss, glenoid track, hill-sachs interval (HIS), HS/glenoid track ratio, and intact anterior articular angle (IAAA) were performed for all patients with magnetic resonance imaging (MRI). All patients were contacted at final follow-up to collect outcome scores (PASS and SANE scores, activity level). A multivariable logistic regression analysis was performed to identify predictors of revision surgery or subjective instability (RI). RESULTS: 86 patients were identified to meet inclusion criteria and 69 of these patients, 53 males and 16 females with a median age of 16 years [15, 17], had minimum 1-year clinical follow-up and were included in assessment of clinical outcomes and multivariable analysis. 12 patients (17%) had revision surgery and 10 patients had subjective instability without revision (14%) In univariate analysis (Table 1), patient height was the only patient factor which was significantly different between the revision/instability (RI) cohort and the non-revision/instability (NRI) cohort. All 86 patients were included in radiographic analysis. Intra- and inter-rater reliability (ICCs) for radiographic measurements are presented in table 2. Agreement was good and excellent for all measurements with the exception of inter-rater reliability of IAAA. Multivariable regression analysis demonstrated that HS/glenoid track ratio was not a predictor for RI. PASS and SANE scores at final follow-up were significantly lower in the RI cohort (79.5 and 70) respectively) as compared to the NRI cohort (94 and 90 respectively), p<0.001. 42 patients (69%) returned to the same or higher level of sports following surgery and this was no different between RI and NRI cohorts. CONCLUSIONS: 31% of adolescent patients in our cohort experienced RI following arthroscopic bankart repair and this was associated with inferior PASS and SANE scores. Off-track lesions were not predictive of failure with primary repair.


2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110018
Author(s):  
Emilio Calvo ◽  
Gonzalo Luengo ◽  
Diana Morcillo ◽  
Antonio M. Foruria ◽  
María Valencia

Background: Limited evidence is available regarding the recommended technique of revision surgery for recurrent shoulder instability. Only 1 previous study has compared the results of soft tissue repair and the Latarjet technique in patients with persistent shoulder instability after primary surgical stabilization. Purpose/Hypothesis: To evaluate the results of revision surgery in patients with previous surgical stabilization failure and subcritical glenoid bone defects, comparing repeated Bankart repair versus arthroscopic Latarjet technique. The hypothesis was that Latarjet would be superior to soft tissue procedures in terms of objective and subjective functional scores, recurrence rates, and range of movement. Study Design: Cohort study; Level of evidence, 3. Methods: Included were 45 patients (mean age, 29.1 ± 8.9 years) with subcritical bone loss (<15% of articular surface) who had undergone revision anterior shoulder instability repair after failed Bankart repair. Of these, 17 patients had arthroscopic Bankart repair and 28 had arthroscopic Latarjet surgery. Patients were evaluated at a minimum of 2 years postoperatively with the Rowe score, Western Ontario Shoulder Instability Index, and Subjective Shoulder Value. Subluxation or dislocation episodes were considered failures. Results: No statistically significant differences were found between groups in age, sex, sporting activity, preoperative Rowe score, or the presence of hyperlaxity or bony lesions. At revision arthroscopy, 20 shoulders showed a persistent Bankart lesion, 13 a medially healed labrum, and 6 a bony Bankart. In 6 patients, no abnormalities were present that could explain postoperative recurrence. In the Bankart repair group, 7 patients underwent isolated Bankart procedures; in the remaining 10 cases, a capsular shift was added. No significant differences were found between the Bankart and Latarjet groups in outcome scores, recurrence rate (11.8% vs 17.9%, respectively), or postoperative athletic activity level. The mean loss of passive external rotation at 0° and 90° of abduction was similar between groups. Conclusion: Arthroscopic Latarjet did not lead to superior results compared with repeated Bankart repair in patients with subcritical glenoid bone loss and recurrent anterior shoulder instability after Bankart repair.


2021 ◽  
pp. 036354652110182
Author(s):  
Craig R. Bottoni ◽  
John D. Johnson ◽  
Liang Zhou ◽  
Sarah G. Raybin ◽  
James S. Shaha ◽  
...  

Background: Recent studies have demonstrated equivalent short-term results when comparing arthroscopic versus open anterior shoulder stabilization. However, none have evaluated the long-term clinical outcomes of patients after arthroscopic or open anterior shoulder stabilization, with inclusion of an assessment of preoperative glenoid tracking. Purpose: To compare long-term clinical outcomes of patients with recurrent anterior shoulder instability randomized to open and arthroscopic stabilization groups. Additionally, preoperative magnetic resonance imaging (MRI) studies were used to assess whether the shoulders were “on-track” or “off-track” to ascertain a prediction of increased failure risk. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A consecutive series of 64 patients with recurrent anterior shoulder instability were randomized to receive either arthroscopic or open stabilization by a single surgeon. Follow-up assessments were performed at minimum 15-year follow-up using established postoperative evaluations. Clinical failure was defined as any recurrent dislocation postoperatively or subjective instability. Preoperative MRI scans were obtained to calculate the glenoid track and designate shoulders as on-track or off-track. These results were then correlated with the patients’ clinical results at their latest follow-up. Results: Of 64 patients, 60 (28 arthroscopic and 32 open) were contacted or examined for follow-up (range, 15-17 years). The mean age at the time of surgery was 25 years (range, 19-42 years), while the mean age at the time of this assessment was 40 years (range, 34-57 years). The rates of arthroscopic and open long-term failure were 14.3% (4/28) and 12.5% (4/32), respectively. There were no differences in subjective shoulder outcome scores between the treatment groups. Of the 56 shoulders, with available MRI studies, 8 (14.3%) were determined to be off-track. Of these 8 shoulders, there were 2 surgical failures (25.0%; 1 treated arthroscopically, 1 treated open). In the on-track group, 6 of 48 had failed surgery (12.5%; 3 open, 3 arthroscopic [ P = .280]). Conclusion: Long-term clinical outcomes were comparable at 15 years postoperatively between the arthroscopic and open stabilization groups. The presence of an off-track lesion may be associated with a higher rate of recurrent instability in both cohorts at long-term follow-up; however, this study was underpowered to verify this situation.


Sign in / Sign up

Export Citation Format

Share Document