Defining the Minimal Clinically Important Difference and Patient Acceptable Symptom State for Arthroscopic Anterior Shoulder Stabilization at 2-Year Follow-up

Abstract

Background:

There is a paucity of literature on the short-term clinical significance and patient-reported outcome measures (PROMs) after arthroscopic stabilization for anterior shoulder instability.

Purpose:

(1) To define the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds for arthroscopic anterior shoulder stabilization at a minimum 2-year follow-up. (2) To investigate predictive factors, including preoperative, demographic, and intraoperative variables, for achieving MCID and PASS.

Study Design:

Case-control study.

Methods:

Patients who underwent primary arthroscopic stabilization for anterior-inferior labral tears from March 2018 to December 2021 with a minimum of 2-year follow-up were retrospectively identified through a prospectively maintained institutional database. MCID thresholds were determined by a distribution-based method, while PASS thresholds were established using an anchor-based method. The PROMs analyzed included the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE), Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE), and the Veterans Rand-12 (VR-12) score. Multivariate logistic regression was performed to identify factors associated with achieving MCID and PASS.

Results:

A total of 65 patients were included. The thresholds for MCID achievement and achievement rates were as follows: WOSI, 12.8 (84.6%); SANE, 14.4 (81.5%); PROMIS UE 4.4 (90.8%); VR-12 Physical, 3.9 (76.9%). The thresholds for PASS achievement and achievement rates were as follows: WOSI, 40.2 (80%); SANE, 74.9 (86.2%); PROMIS UE 40.5 (84.8%); VR-12 Physical, 49.9 (83.1%). Symptom duration >6 months was predictive of failing to achieve MCID for the WOSI and PASS for the WOSI and SANE. Preoperative hyperlaxity was predictive of failing to achieve PASS for the WOSI and PROMIS UE. A lower body mass index (BMI) was predictive of achieving PASS for the WOSI, PROMIS UE, and VR-12. The presence of an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion was predictive of failing to achieve PASS for the WOSI and failing to achieve MCID and PASS for the WOSI, PROMIS UE, and VR-12 simultaneously.

Conclusion:

This study defines thresholds for MCID and PASS achievement at a minimum 2-year follow-up for patients undergoing arthroscopic anterior shoulder stabilization. Factors including symptom duration, hyperlaxity, BMI, and ALPSA lesions were found to be predictive of MCID and PASS achievement on multiple PROMs at short-term follow-up.

Keywords

arthroscopic stabilization Bankart repair clinically significant outcomes shoulder instability

The shoulder's inherent functional demands, along with its multiplanar range of motion, make it susceptible to various pathological conditions that result in instability of the glenohumeral joint.¹² Achieving stability necessitates precise coordination between the static and dynamic stabilizers of the joint—including the labrum, glenohumeral ligaments, and the rotator cuff.¹² Instability manifests as either subluxation or dislocation of the humeral head from the glenoid, often resulting in labral tears and associated bone loss of the glenoid or humerus.⁴² While instability can be multidirectional, anterior shoulder instability accounts for >95% of events with an incidence of 23.9 per 100,000 person-years.⁴² The most common causes of anterior shoulder instability are traumatic anterior shoulder dislocations, with higher rates seen in men, contact athletes, and enlisted military personnel.⁴² In cases with subcritical glenoid bone loss or nonengaging Hill-Sachs lesions, arthroscopic stabilization involving an isolated Bankart repair is used to restore function and prevent subsequent dislocations and bone loss.¹³

While functional outcomes and failure rates have been extensively studied,^19,21,30 there is a paucity of literature describing the clinically significant outcomes of patients who successfully undergo arthroscopic stabilization and do not subsequently dislocate. The minimum clinically important difference (MCID) was developed to determine the smallest change in a patient's condition that is clinically significant after an orthopaedic surgery procedure.^23,38 Similarly, the patient acceptable symptom state (PASS) denotes the postoperative level of symptoms and functional state that patients deem to be satisfactory.^8,23 In clinical practice, defining these thresholds is highly relevant as it translates statistical improvements in patient-reported outcome measures (PROMs) into tangible benchmarks of patient success. Whether patients undergoing arthroscopic stabilization for anterior instability achieve these thresholds at the 1-year time point was previously studied by Park et al.^32,33 However, 1-year follow-up is often insufficient to evaluate the outcomes after stabilization procedures, given higher rates of treatment failure or recurrent instability as patients become further removed from the index procedure.^26,30

This study aimed to (1) define the MCID and PASS thresholds for primary arthroscopic stabilization for anterior instability at a minimum 2-year follow-up and (2) determine predictors of MCID and PASS achievement. The authors hypothesized that symptom duration and recurrent frank dislocations before stabilization would predict MCID and PASS achievement.

Methods

Patient Selection

A retrospective case series was conducted by querying a prospectively collected shoulder instability database from a single institution. All patients presented with symptoms indicative of anterior instability—including frank dislocations or persistent subluxation. A magnetic resonance image and or MR arthrogram showing evidence of an anterior-inferior labral tear was obtained in all patients. Computed tomography imaging was additionally used to confirm the presence or absence of associated glenoid bone loss and for subsequent assessment of an associated Hill-Sachs lesion. The indication for surgery was based on clinical evaluation—including a positive sulcus sign, apprehension, and load-and-shift or relocation tests. An intraoperative examination under anesthesia was performed—including anterior load and shift. Patients with grade 3 anterior instability on examination were defined as having hyperlaxity. Subsequent diagnostic arthroscopy was performed to confirm the diagnosis of an anterior inferior labral tear and to confirm the presence of concomitant pathology—including biceps tenosynovitis, Hill-Sachs lesions, anterior labroligamentous periosteal sleeve avulsion (ALPSA), glenolabral articular disruption (GLAD), glenohumeral ligament disruption, or superior labrum anterior to posterior (SLAP) lesions.

Patients meeting the inclusion criteria had undergone primary arthroscopic stabilization for anterior shoulder instability and had a minimum of 2 years of postoperative follow-up. All procedures were performed by 1 of 6 fellowship-trained attending surgeons (J.C., B.F., A.B.Y., B.J.C., and N.N.V.) between August 2018 and December 2021. The exclusion criteria included revision stabilization procedures; cartilage procedures of the glenoid or humerus; humeral head procedures, including remplissage; glenoid bone loss >10%; glenoid fracture reduction and fixation; concomitant rotator cuff tears; isolated posterior labral or SLAP tears; or glenoid/humeral bony reconstruction procedures (eg, Latarjet or distal tibial allograft). Patients lacking complete baseline PROMs were also excluded. Patients who underwent a revision procedure, such as a Latarjet or distal tibial allograft, before final follow-up were excluded from the analysis to avoid conflating the clinically significant thresholds established in this study with those of a more invasive instability procedure. Institutional review board approval for database querying and patient follow-up was obtained (ORA No. 23110601).

Outcome Measures

An institutional electronic medical record was used to record demographic and intraoperative variables for all study participants. PROMs were assessed pre- and postoperatively and included the Western Ontario Shoulder Instability Index (WOSI) score, Single Assessment Numeric Evaluation (SANE) score, Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE) score, and Veterans Rand-12 (VR) score. A secure electronic platform, Patient IQ, was utilized for PROMs distribution and storage. The MCID was defined as the smallest change in a patient's condition that they can appreciate clinically, while the PASS was defined as the state at which patients considered their level of symptoms and function satisfactory.^11,23,38 The proportion of patients who achieved MCID and PASS for all 4 PROMs evaluated in this study was also noted.

Statistical Analysis

Statistical analysis was performed using R (R Core Team). A 2-tailed, paired Student t test was used to evaluate for statistically significant improvements in PROM scores. The MCID was calculated using a distribution-based approach, defined as half the standard deviation of the difference between baseline and final follow-up PROM scores, in line with established literature.⁴⁶ PASS thresholds were established using an anchor-based approach incorporating the following anchor question: “Taking into account the activities in your daily life, your level of pain, and also your functional impairment, do you feel that the current state of your shoulder is satisfactory?” A receiver operating characteristic analysis was then performed to determine what PROM values were most predictive of satisfactory response to the anchor question. An area under the curve (AUC) of 0.7 to 0.8 was considered acceptable, while AUC values exceeding 0.8 and 0.9 were considered excellent and outstanding, respectively.²⁵ Demographic and intraoperative variables were included in a multivariate regression to evaluate which variables were predictive of achieving MCID or PASS on patient-reported outcome scales at a minimum 2-year follow-up.

Results

A total of 65 patients (74.7% compliance) who underwent primary arthroscopic stabilization for anterior shoulder instability from May 2018 to December 2021 were identified and included in the analysis (Figure 1). The cohort had a mean age of 23.7 ± 8.2 years and was predominantly men (n = 43; 66.1%) with a mean follow-up of 43.8 ± 12.5 months. Over half of the cohort were contact or overhead athletes (n = 39; 60%). The majority of the cohort suffered either a single frank dislocation (n = 14 [21.5%]) or multiple dislocations (n = 30 [46.2%]) before stabilization. Finally, a majority of the cohort reported a traumatic etiology (n = 54 [83.1%]) and had >6 months of symptoms before stabilization (n = 36 [55.9%]). No study participants had glenoid bone loss >10% or off-track Hill-Sachs lesions (Table 1).

Figure 1.

Flow chart of patient inclusion.

Table 1

Patient Demographic Characteristics ^a

Outcome	Value	Percentage
Age, years	23.7 ± 8.2
BMI, kg/m²	26.1 ± 4.1
Follow-up, months	43.8 ± 12.5
Sex, male: female
Male	43	66.1
Female	22	33.9
Laterality, right: left
Right	43	66.1
Left	22	33.9
Athlete		13.8
Contact or overhead	39	60
History of dislocations		7.5
Subluxation only	9	13.9
One dislocation event	14	21.5
Multiple dislocations	30	46.2
Traumatic cause
Yes	54	83.1
No	11	16.9
Duration of symptoms, months
<6	29	44.1
>6	36	55.9

Data are presented as n, %, or mean ± SD. BMI, body mass index.

Examination under anesthesia revealed that the majority of patients had either grade 2 (n = 31 [47.7%]) or grade 3 (n = 24 [36.9%]) anterior load or shift. A minority of the cohort had concomitant pathology diagnosed during arthroscopy, including ALPSA (n = 5 [7.7%]), GLAD (n = 3 [5.1%]), humeral avulsion of the glenohumeral ligament (HAGL)/glenoid avulsion of the glenohumeral ligament (GAGL) (n = 4 [6.2%]), and SLAP lesions (n = 5 [7.7%]). A minority of the cohort additionally underwent concomitant biceps tenodesis (n = 11 [17%]) (Table 2).

Table 2

Patient Intraoperative Characteristics ^a

Outcome	Value	Percentage
Anterior instability grade
1	10	15.4
2	31	47.7
3	24	36.9
ALPSA lesion	5	7.7
Bony Bankart	9	13.8
GLAD lesion	3	5.1
Glenohumeral ligament avulsion	4	6.2
SLAP lesion	5	7.7
Biceps tenodesis	11	17

ALPSA, anterior labroligamentous periosteal sleeve avulsion; GLAD, glenolabral articular disruption; SLAP, superior labrum anterior to posterior.

The mean preoperative and postoperative scores for WOSI, SANE, PROMIS UE, and VR-12 Physical scores are outlined in Table 3, with all changes from baseline for all PROMs being statistically significant (P < .001). The MCID thresholds for WOSI, SANE, PROMIS UE, and PROMIS VR-12 Physical were set at 12.8, 14.4, 4.4, and 3.9, respectively, and achievement rates ranged from 76.9% to 90.8%. The PASS thresholds for WOSI, SANE, PROMIS UE, and VR-12 Physical were defined as 40.2, 74.9, 40.5, and 49.9, respectively, and the achievement rates ranged from 80% to 86.2%. MCID was achieved for all 4 PROMs by 61.5% of patients, while 67.7% (n = 44/65) achieved PASS for all PROMs. The AUC across all PASS thresholds ranged from 0.836 to 0.977, indicative of excellent predictive value (Figure 2).²⁵ The VR-12 Mental Score was found to have an AUC <0.70 and was therefore excluded from the analysis of clinically significant thresholds.

Table 3

MCID and PASS Thresholds and Percentage Achievement Among Patients ^a

PROM	Baseline	Follow-up	P	MCID Threshold	Number Achieved	PASS Threshold	Number Achieved (%)
WOSI	53.7 ± 19.9	18.7 ± 22.6	<.001	12.8	55/65 (84.6)	40.2	52/65 (80)
SANE	49.7 ± 25.9	86.3 ± 14.2	<.001	14.4	53/65 (81.5)	74.9	56/65 (86.2)
PROMIS UE	36.3 ± 7.1	52.1 ± 8.9	<.001	4.4	59/65 (90.8)	40.5	55/65 (84.8)
VR 12 P	45.9 ± 7.8	54.8 ± 6.4	<.001	3.9	50/65 (76.9)	49.9	54/65 (83.1)

Data are presented as mean ± SD, unless otherwise indicated. P values indicate the comparison of the mean preoperative score to the mean postoperative score within a given outcome score. Percentages indicate a sample size of 65. MCID, minimal clinically important difference; PASS, patient acceptable symptoms; PROM, patient-reported outcome measure; PROMIS UE: Patient-Reported Outcomes Measurement Information System Upper Extremity; SANE, Shoulder Assessment Numeric Evaluation; VR-12 P, Veterans Rand-12 Items Health Survey Physical Score; WOSI, Western Ontario Shoulder Instability Index.

Figure 2.

ROC for PASS thresholds. PASS, patient acceptable symptoms; ROC, receiver operating curves.

Variables Predictive of MCID/PASS Achievement

For the WOSI, a higher preoperative score (odds ratio [OR], 1.19 [95% CI, 1.05-0.51]; P = .044) was predictive of achieving MCID, while symptom duration >6 months (OR, 0.08 [95% CI, 0.01-0.56]; P = .032) was predictive of failing to achieve MCID. A lower body mass index (BMI) (OR, 0.74 [95% CI, 0.01-0.92]; P = .012) was predictive of achieving PASS, whereas hyperlaxity (OR, 0.10 [95% CI, 0.01-0.55]; P = .016), symptom duration >6 months (OR, 0.11 [95% CI, 0.01-0.52]; P = .023) and the presence of an ALPSA lesion (OR, 0.01 [95% CI, 0.01-0.75]; P = .004) were predictive of failing to achieve PASS (Tables 4 and 5).

Table 4

Significant Predictors of MCID Achievement in Logistic Regression Analyses ^a

Predictive Variable	OR [95%CI]	P
WOSI
Preop score	1.19 [1.05-1.51]	.044
Symptoms >6 months	0.08 [0.01-0.56]	.032
SANE
Preop score	0.87 [0.77-0.94]	.004
Age	0.84 [0.69-0.96]	.027
PROMIS UE
-	-	-
VR-12 Physical
Preop score	0.84 [0.73-0.94]	.009
All PROMs
Age	0.90 [0.83-0.98]	.013
History of dislocation	5.70 [1.26-26.62]	.032
Symptoms >6 months	0.25 [0.06-0.90]	.045
ALPSA	0.05 [0.01-0.47]	.021

ALPSA, anterior labroligamentous periosteal sleeve avulsion; MCID, minimal clinically important difference; PROMs, patient-reported outcome measures; Preop, preoperative; PROMIS UE: Patient-Reported Outcomes Measurement Information System Upper Extremity; SANE, Shoulder Assessment Numeric Evaluation; VR-12 P, Veterans Rand-12 Items Health Survey Physical Score; WOSI, Western Ontario Shoulder Instability Index.

Table 5

Significant Predictors of PASS Achievement in Logistic Regression Analyses ^a

Predictive Variable	OR [95% CI]	P
WOSI
Symptoms >6 months	0.11 [0.01-0.52]	.023
Hyperlaxity	0.10 [0.01-0.55]	.016
BMI	0.74 [0.56-0.92]	.012
ALPSA lesion	0.01 [0.01-0.75]	.004
SANE
Symptoms >6 months	0.09 [0.01-0.74]	.039
PROMIS UE
BMI	0.63 [0.42-0.83]	.007
Hyperlaxity	0.08 [0.01-0.59]	.026
VR-12 Physical
BMI	0.77 [0.58-0.95]	.027
All PROMs
BMI	0.75 [0.59-0.92]	.012
ALPSA lesion	0.07 [0.01-0.83]	.004

ALPSA, anterior labroligamentous periosteal sleeve avulsion; BMI, body mass index; PASS, patient acceptable symptom state; PROMs, patient-reported outcome measures; Preop, preoperative; PROMIS UE, Patient-Reported Outcomes Measurement Information System Upper Extremity; SANE, Shoulder Assessment Numeric Evaluation; VR 12 P, Veterans Rand 12 Items Health Survey Physical Score; WOSI, Western Ontario Shoulder Instability Index.

For the SANE, a lower preoperative score (OR, 0.87 [95% CI, 0.77-0.94]; P = .004) and younger age (OR, 0.84 [95% CI, 0.69-0.96]; P = .027) were predictive of achieving MCID. A symptom duration >6 months (OR, 0.09 [95% CI, 0.01-0.74]; P = .039) was predictive of failing to achieve PASS (Tables 4 and 5).

For the PROMIS UE, no variables were found to be predictive of MCID achievement. A lower BMI (OR, 0.63 [95% CI, 0.42-0.83]; P = .007) was predictive of achieving PASS, while hyperlaxity (OR, 0.08 [95% CI, 0.01-0.59]; P = .026) was predictive of failing to achieve PASS (Tables 4 and 5).

For VR-12 Physical, a lower preoperative score (OR, 0.84 [95% CI, 0.73-0.94]; P = .009) was predictive of achieving MCID, while a lower BMI was predictive of achieving PASS (OR, 0.77 [95% CI, 0.58-0.95]; P = .027) (Tables 4 and 5).

A younger age (OR, 0.90 [95% CI, 0.83-0.98]; P = .013) and a history of frank dislocation (OR, 5.70 [95% CI, 1.26-26.62]; P = .032) were predictive of achieving MCID for all 4 PROMs, whereas symptom duration >6 months (OR, 0.25 [95% CI, 0.06-0.90]; P = .045) and the presence of an ALPSA lesion (OR, 0.05 [95% CI, 0.01-0.47]; P = .021) were predictive of failing to achieve MCID for all 4 PROMs. A lower BMI (OR, 0.90 [95% CI, 0.83-0.98]; P = .013) was predictive of achieving PASS for all 4 PROMs while the presence of an ALPSA lesion (OR, 0.90 [95% CI, 0.83-0.98]; P = .013) was predictive of failing to achieve PASS for all 4 PROMs (Tables 4 and 5).

Factors that were not found to be predictive of either MCID or PASS achievement included athlete status, traumatic cause, and the presence of a bony Bankart, GLAD, HAGL/GAGL, or SLAP lesion.

Failure Rate and Complications

Seven patients suffered complications that were managed nonoperatively. Four patients had persistent pain on examination that improved with glenohumeral corticosteroid injections. Three patients noted subjective feelings of apprehension postoperatively despite not suffering a frank dislocation or subluxation after initial stabilization.

Three patients underwent subsequent procedures before final follow-up to address persistent pain—including subacromial decompression with distal clavicle excision (n = 1) or biceps tenodesis (n = 2). Two patients suffered recurrent dislocations that were treated nonoperatively at final follow-up. Five patients underwent a bone block or Latarjet procedure and were excluded from the analysis of MCID and PASS thresholds for PROM scores (Figure 1).

Discussion

This study established MCID and PASS thresholds for the WOSI, SANE, PROMIS UE, and VR-12 Physical scores in patients undergoing arthroscopic stabilization for anterior instability, with a minimum 2-year follow-up. Predictive factors for achieving or failing to achieve clinically significant outcomes were investigated. Notably, symptom duration before stabilization, hyperlaxity during examination under anesthesia, and lower baseline BMI and age emerged as predictors of achieving MCID and PASS thresholds. These findings highlight the importance of considering these factors in shared decision-making processes when assessing the potential benefits of arthroscopic stabilization for anterior instability.

This study reports significant improvements in all WOSI, SANE, PROMIS UE, and VR-12 scores, and a 10% (n = 7/70) recurrence rate with a mean follow-up of 43.8 ± 12.5 months, supporting the utility of arthroscopic stabilization in properly selected patients with anterior shoulder instability. Regarding clinical significance, rates of achieving MCID and PASS for individual PROMs ranged from 76.9% to 90.8% and 80% to 86.2%, respectively. The attainment of MCID requires patients to perceive a noticeable change, whereas PASS requires them to find their current symptom level satisfactory.^11,23,38 Lower preoperative scores on the SANE and VR-12, along with higher preoperative scores on the WOSI, were predictive of achieving MCID for those respective scales, which is logical given the distribution-based method used in this study to calculate MCID. Hence, patients with poorer baseline functional scores may anticipate greater improvement after arthroscopic stabilization. Similarly, a history of frank dislocation was predictive of achieving MCID for all PROMs. These results suggest that patients with 1 or more dislocations before stabilization experience greater improvement than those with persistent subluxation alone.

Previous studies have examined clinically significant outcomes for anterior stabilization at the 1-year time point.^18,32,33 In a 2018 study by Park et al,³² a distribution-based MCID of 5.6 for Rowe and 151.9 for WOSI scores was reported in patients undergoing anterior stabilization. While this study aimed to use a normalized WOSI score on a 100-point scale, an MCID of 12.8 for the normalized WOSI score corresponds to an MCID of 268.6 for the raw WOSI score.³⁶ Consequently, an increase from 151.9 to 268.6 was observed from the 1- to 2-year time points in this study. Such increases in MCID across these time frames have been documented in other studies assessing clinically significant outcomes after orthopaedic procedures.^9,44 Furthermore, as MCID was defined as one-half of the standard deviation of the difference in pre- and postoperative scores, the observed increase in MCID can be attributed to an improvement in WOSI scores and continued functional benefit from the 1- to 2-year time points.

A prolonged symptom duration was predictive of failing to achieve MCID for the WOSI and all PROMs, as well as failure to achieve PASS for the WOSI and SANE, aligning with the authors’ hypothesis. Previous research has identified symptom duration, particularly the time between the initial dislocation and surgery, as a risk factor for recurrent instability.^20,28,40 Additionally, symptom duration was predictive of achieving MCID for American Shoulder and Elbow Surgeons (ASES) scores at the 1-year time point in a previous study.³³ It can be argued that patients with chronic instability experience ongoing degeneration of both the labrum and capsule, hindering the ability to achieve a robust repair after stabilization.³⁷ Moreover, chronic instability is associated with glenoid and humeral bone loss, which not only increases the risk of primary stabilization failure but may also contribute to persistent feelings of instability postoperatively without subsequent dislocation.^4,16,35 Dekker et al¹⁴ previously suggested that symptom duration >5 months warrants consideration of a bony procedure or discussion with the patient regarding the heightened risk of stabilization failure. Recent evidence also emphasizes the benefits of prompt intervention in managing first-time dislocations compared with conservative treatment.^1,43 As consensus shifts toward surgical management in first-time dislocations,^6,7,22 evaluating symptom duration and promptly intervening when surgery is indicated are crucial for optimizing outcomes after arthroscopic stabilization.

Heightened glenohumeral capsular laxity on the anterior load-and-shift test was predictive of failing to achieve PASS on the WOSI and PROMIS UE. Hyperlaxity, present in up to 13% of patients sustaining first-time dislocations, carries significant clinical implications for patients undergoing anterior stabilization.¹⁰ Notably, hyperlaxity has been established as a risk factor for treatment failure in Bankart repair, both in primary and revision settings.^5,34,39,41 Consequently, hyperlaxity has been incorporated into composite scores, such as the Instability Severity Index Score, aimed at stratifying patients based on their risk of recurrent instability.³ Grade 3 anterior translation during the load and shift test indicates that the humeral head translates >50% of the glenoid rim and dislocates without spontaneous reduction.²⁴ This suggests that patients with grade 3 translation may have incompetent capsules due to significant shoulder trauma or persistent dislocations. The findings of this study imply that hyperlaxity not only increases the risk of failure but also reduces the likelihood of achieving clinically significant outcomes after anterior stabilization.

BMI was also inversely correlated with achieving PASS for the WOSI, PROMIS UE, VR-12 Physical, and all PROMs. While there is a paucity of literature investigating the influence of BMI on outcomes in arthroscopic stabilization, previous studies have assessed its associations with outcomes of other upper extremity procedures—including rotator cuff repair and shoulder arthroplasty.^15,45,47 Although inconsistent results have been reported in the literature, BMI has been associated with longer operative time and increased risk of complications and reoperation after rotator cuff repair and total shoulder arthroplasty.^15,45,47 A study assessing the effect of BMI on anterior stabilization at the 1-year timepoint found that elevated BMI was associated with longer operative time, a shorter time to complication, and smaller magnitudes of improvement in functional scores.³¹ While concomitant rotator cuff tears were excluded in this study, the authors also noted that patients with elevated BMI were significantly more likely to present with partial rotator cuff tears.³¹ Notably, Park et al³³ found that elevated BMI was predictive of failing to achieve MCID for ASES. These findings are of significant importance, as BMI is a potentially modifiable risk factor that can improve outcomes after arthroscopic stabilization.

The findings of this study also report that the presence of an ALPSA lesion was predictive of failing to achieve PASS for the WOSI, in addition to MCID and PASS for all 4 PROMs. ALPSA lesions involve an avulsion and subsequent medial displacement of the anterior inferior labrum from the glenoid.^2,27 The lesions are a sequelae of chronic instability and have been reported to carry over twice the risk of recurrent instability compared with Bankart lesions, leading to further glenoid and humeral bone loss and cartilage degradation.^17,29 While a previous cohort study comparing outcomes of arthroscopic stabilization for ALSPA and Bankart lesions noted inferior, but insignificant, differences in PROMs,² this study demonstrates that ALPSA lesions significantly influence attainment of clinically significant thresholds. Overall, these findings further support the argument for surgical intervention in first-time dislocations at risk of subsequent dislocations to prevent the development of ALPSA lesions and further shoulder joint degeneration.

Limitations

This study poses several limitations that warrant consideration. Firstly, all procedures were conducted at a single, high-volume institution, which may affect the generalizability of the findings. While this study establishes MCID and PASS values for arthroscopic anterior stabilization, comparisons with 1-year thresholds were limited to the WOSI score because of variability in the adaptation of PROMs. Moreover, the results may be prone to selection bias, as only patients who completed PROMs at a minimum 2-year follow-up were included in the analysis. Inconsistencies in the documentation of the number of dislocation events or arm dominance hindered the inclusion of these factors in the multivariate regression. Furthermore, differences in age, activity level, and severity of labral tearing could potentially confound results after arthroscopic anterior stabilization. Lastly, our sample size of 65 patients may limit the ability to detect smaller differences in certain subanalyses. The inclusion of concomitant pathologies and concurrent procedures introduces some cohort heterogeneity. However, strict exclusion criteria were applied to exclude major confounding procedures and cases with significant humeral and glenoid bone loss, ensuring the cohort accurately reflects the true clinical presentation of patients indicated for primary arthroscopic anterior shoulder stabilization. Furthermore, our use of multivariate regression was specifically designed to control for these variables and isolate their individual impacts on clinical outcomes.

Conclusion

This study defines the thresholds for MCID and PASS achievement at a minimum 2-year follow-up in a cohort of patients undergoing primary arthroscopic anterior shoulder stabilization. Factors such as symptom duration, hyperlaxity, BMI, and ALPSA lesions were found to be predictive of MCID and PASS achievement on multiple PROMs at 2-year follow-up.

Footnotes

Final revision submitted March 8, 2026; accepted March 16, 2026.

One or more of the authors has declared the following potential conflict of interest or source of funding: J.P.S. receives intellectual property royalties from Arthrex, DJO, LLC, and Stryker Corp; serves on the Abstract Review Committee for the American Shoulder and Elbow Surgeons; and serves on the Editorial Board of Arthroscopy. J.C. serves as a board or committee member for the American Orthopaedic Society for Sports Medicine, the Arthroscopy Association of North America, and the International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine; is a paid consultant for Arthrex, Inc, CONMED Linvatec, Ossur, RTI Surgical Inc, and Smith & Nephew; receives hospitality payments from Breg Inc, DePuy Synthes Sales Inc, Joint Restoration Foundation Inc, Medical Device Business Services Inc, Pacira Pharmaceuticals Incorporated, SI-Bone Inc, and Vericel Corporation; receives educational support from Midwest Associates; and serves as a paid presenter or speaker for Smith & Nephew. B.F. receives hospitality payments from AbbVie Inc, Amgen Inc, DePuy Synthes Sales Inc, Linvatec Corp, and Vericel Corp; serves as a board or committee member for the American Orthopaedic Society for Sports Medicine; receives research support from Arthrex, Inc, Smith & Nephew, and Stryker; receives publishing royalties and financial or material support from Elsevier; holds stock or stock options in iBrainTech, Sparta Biopharma, and Zuno Medical; receives educational support from Midwest Associates; serves as a paid consultant for Smith & Nephew and Stryker; and serves on the editorial or governing board of the Video Journal of Sports Medicine. B.J.C. receives research support from Aesculap/B. Braun, Arthrex, Inc, and the National Institutes of Health (National Institute of Arthritis and Musculoskeletal and Skin Diseases [[NIAMS] and Eunice Kennedy Shriver National Institute of Child Health and Human Development [NICHD]); is a paid consultant for Acumed LLC, Arthrex, Inc, Bioventus LLC, DJO LLC, Endo Pharmaceuticals Inc, Ferring Pharmaceuticals Inc, Flexion Therapeutics Inc, Geistlich Pharma North America Inc, and Pacira Pharmaceuticals Incorporated; receives intellectual property royalties from Arthrex, Inc and Elsevier Publishing; serves as a board or committee member for the Arthroscopy Association of North America; serves on the editorial or governing board of the American Journal of Sports Medicine and the Journal of the American Academy of Orthopaedic Surgeons; holds stock or stock options in Bandgrip Inc and Ossio; receives hospitality payments from Encore Medical LP, GE Healthcare, Geistlich Pharma North America Inc, Mallinckrodt LLC, Merck Sharp and Dohme Corporation, Organogenesis Inc, Orthofix Medical Inc, PAVmed Inc, Pinnacle Inc, Pylant Medical, Summit Surgical Corp, Trice Medical Inc, and Zimmer Biomet Holdings Inc; receives other financial or material support from JRF Ortho; receives publishing royalties and financial or material support from Operative Techniques in Sports Medicine; serves as a paid presenter for LifeNet Health and Terumo BCT. N.N.V. receives intellectual property royalties from Arthrex, Inc, Graymont Professional Products IP LLC, Smith & Nephew, and Stryker; receives research support from Arthrex, Inc, Breg, Ossur, Smith & Nephew, and Stryker; is a paid consultant for Medacta USA Inc and Stryker; serves as a board or committee member for the American Orthopaedic Society for Sports Medicine, the American Shoulder and Elbow Surgeons, and the Arthroscopy Association of North America; serves on the editorial or governing board of SLACK Incorporated; receives hospitality payments from Abbott Laboratories, Axonics Inc, Boston Scientific Corp, Foundation Fusion Solutions LLC, IBSA Pharma Inc, Nalu Medical Inc, Nevro Corp, Orthofix Medical Inc, Pacira Pharmaceuticals Incorporated, Relievant Medsystems Inc, Salix Pharmaceuticals, Vericel Corporation, and Vertos Medical Inc; and receives educational support from Medwest Associates and travel and lodging support from Spinal Simplicity LLC.

Ethical approval for this study was obtained from Rush University Medical Center (ORA No.: 23110601-IRB01).

ORCID iDs

Rodrigo Saad Berreta

John P. Scanaliato

Adam B. Yanke

Brian J. Cole

References

Alkhatib

Abdullah

ASA

AlNouri

Ahmad Alzobi

Alkaramany

Ishibashi

Short- and long-term outcomes in Bankart repair vs. conservative treatment for first-time anterior shoulder dislocation: a systematic review and meta-analysis of randomized controlled trials. J Shoulder Elbow Surg. 2022;31(8):1751-1762.

Arner

Cooper

Elrick

, et al. Outcomes of arthroscopic anterior labroligamentous periosteal sleeve avulsion lesions: a minimum 2-year follow-up. Am J Sports Med. 2022;50(6):1512-1519.

Balg

Boileau

The instability severity index score. A simple pre-operative score to select patients for arthroscopic or open shoulder stabilisation. J Bone Joint Surg Br. 2007;89(11):1470-1477.

Bedrin

Owens

Slaven

, et al. Prospective evaluation of posterior glenoid bone loss after first-time and recurrent posterior glenohumeral instability events. Am J Sports Med. 2022;50(11):3028-3035.

Boileau

Villalba

Héry

Balg

Ahrens

Neyton

Risk factors for recurrence of shoulder instability after arthroscopic Bankart repair. J Bone Joint Surg Am. 2006;88(8):1755-1763.

Boone

Arciero

RA.

First-time anterior shoulder dislocations: has the standard changed?

Br J Sports Med. 2010;44(5):355-360.

Bottoni

Wilckens

DeBerardino

, et al. A prospective, randomized evaluation of arthroscopic stabilization versus nonoperative treatment in patients with acute, traumatic, first-time shoulder dislocations. Am J Sports Med. 2002;30(4):576-580.

Chahal

Van Thiel

Mather

, et al. The patient acceptable symptomatic state for the modified Harris Hip Score and Hip Outcome Score among patients undergoing surgical treatment for femoroacetabular impingement. Am J Sports Med. 2015;43(8):1844-1849.

Chahla

Kunze

Tauro

, et al. Defining the minimal clinically important difference and patient acceptable symptom state for microfracture of the knee: a psychometric analysis at short-term follow-up. Am J Sports Med. 2020;48(4):876-883.

10.

Chiang

Wang

Liu

Chen

TH.

Arthroscopic posteroinferior capsular plication and rotator interval closure after Bankart repair in patients with traumatic anterior glenohumeral instability—a minimum follow-up of 5 years. Injury. 2010;41(10):1075-1078.

11.

Copay

Subach

Glassman

Polly

Schuler

TC.

Understanding the minimum clinically important difference: a review of concepts and methods. Spine J. 2007;7(5):541-546.

12.

Cuéllar

Ruiz-Ibán

Cuéllar

Anatomy and biomechanics of the unstable shoulder. Open Orthop J. 2017;11:919-933.

13.

DeFroda

Bokshan

Stern

Sullivan

Owens

BD.

Arthroscopic Bankart repair for the management of anterior shoulder instability: indications and outcomes. Curr Rev Musculoskelet Med. 2017;10(4):442-451.

14.

Dekker

Peebles

Bernhardson

, et al. Risk factors for recurrence after arthroscopic instability repair—the importance of glenoid bone loss >15%, patient age, and duration of symptoms: a matched cohort analysis. Am J Sports Med. 2020;48(12):3036-3041.

15.

De Martino

Gulotta

. The effect of obesity in shoulder arthroplasty outcomes and complications. Orthop Clin North Am. 2018;49(3):353-360.

16.

Dickens

Slaven

Cameron

, et al. Prospective evaluation of glenoid bone loss after first-time and recurrent anterior glenohumeral instability events. Am J Sports Med. 2019;47(5):1082-1089.

17.

Dumont

Golijanin

Provencher

MT.

Shoulder instability in the military. Clin Sports Med. 2014;33(4):707-720.

18.

Foong

Zeng

Goh

Hao

Lie

DTT

Chang

PCC

. Determining the minimal clinically important difference on the Oxford Shoulder Instability Score in patients undergoing arthroscopic Bankart repair for shoulder instability. Orthop J Sports Med. 2022;10(1):23259671211060023.

19.

Fox

Drain

Rai

, et al. Increased failure rates after arthroscopic Bankart repair after second dislocation compared to primary dislocation with comparable clinical outcomes. Arthroscopy. 2023;39(3):682-688.

20.

Hardy

Sabatier

Laboudie

, et al. Outcomes after Latarjet procedure: patients with first-time versus recurrent dislocations. Am J Sports Med. 2020;48(1):21-26.

21.

Hoyt

Roach

Kilcoyne

Dickens

JF.

Predictors of failure of arthroscopic Bankart repair. Oper Tech Orthop. 2020;30(3):100819.

22.

Jakobsen

Johannsen

Suder

Søjbjerg

JO.

Primary repair versus conservative treatment of first-time traumatic anterior dislocation of the shoulder: a randomized study with 10-year follow-up. Arthroscopy. 2007;23(2):118-123.

23.

Kvien

Heiberg

Hagen

KB.

Minimal clinically important improvement/difference (MCII/MCID) and patient acceptable symptom state (PASS): what do these concepts mean?

Ann Rheum Dis. 2007;66 suppl 3(suppl 3):iii40-41.

24.

Lizzio