Inpatient versus outpatient shoulder arthroplasty outcomes: A propensity score matched risk-adjusted analysis demonstrates the safety of outpatient shoulder arthroplasty.

OBJECTIVES: Beginning January 1, 2021 total shoulder arthroplasty (TSA) was removed from the Medicare (U.S national healthcare for patients ≥ 65years of age) inpatient-only list. Furthermore, there is limited data comparing outpatient and inpatient TSA among recent contemporary large population databases. This study aimed to analyze shoulder arthroplasty outcomes between inpatient and outpatient procedures at the national level. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was utilized (2015-2019). Cases with a current procedural terminology of 23472 indicative of primary TSA and reverse total shoulder arthroplasty were included (N = 22,452). Outcomes were then analyzed in two approaches: unmatched analysis and propensity score matched risk-adjusted analysis. RESULTS: Overall, 9.7% (N = 2,185) of cases were performed outpatient and 90.3% (N = 20,357) of cases were performed inpatient. The rate of outpatient procedures has been steadily increasing (2015: 8.3%, 2016: 14.7%, 2017: 15.8%, 2018: 26.5%, 2019: 34.6%; P < 0.001). Outpatients were more likely to be male (50.7% vs. 43.7%) and younger (age < 65; 37.0% vs. 27.9%) and less likely to be ASA class 3 or 4 (49.5% vs. 58.3%). Outpatients had fewer comorbidities including obesity (46.1% vs. 51.9%), hypertension (60.5% vs. 67.4%), diabetes (15.1 vs. 18.2%), chronic obstructive pulmonary disease (4.8% vs. 7.0%), bleeding disorders (1.3% vs. 2.5%), or chronic steroid use (3.5% vs. 5.0%; all P < 0.001). In a non-risk matched analysis of outcomes, outpatient procedures displayed lower rates of any adverse event (3.5% vs. 5.3%; P < 0.001), minor adverse events (1.5% vs. 3.0%; P = 0.001), and readmission (2.2% vs. 2.8%; P = 0.025). Following a propensity score matched analysis, two risk matched cohorts of outpatient (N = 2,172) and inpatient (N = 2,172) procedures were identified. Subsequent analysis of outcomes revealed no significant differences in outcome metrics between risk-matched outpatient and inpatient procedures. CONCLUSIONS: From 2015 to 2019, there has been a four-fold increase in the proportion of outpatient shoulder arthroplasty cases in the ACS-NSQIP database. This study shows that outpatient shoulder arthroplasty may be safely performed in a select cohort of patients without increased risk of adverse events. After adjusting for comorbidities, there were no differences in clinical outcomes or rates of adverse outcomes between inpatient and outpatient shoulder arthroplasty. LEVEL OF EVIDENCE: Retrospective Observational Study, Level IV.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND: Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination. METHODS: The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes. RESULTS: 17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections. CONCLUSION: The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.

Blinded Ultrasound Examination of the Subscapularis Following Anatomic Shoulder Arthroplasty.

BACKGROUND: The subscapularis tendon is commonly released during shoulder arthroplasty, and its integrity and repair postoperatively have been shown important to help maximize patient function. However, diagnosing subscapular tendon failure can be difficult with magnetic resonance imaging secondary to metal artifact as well as very costly. PURPOSE: The purpose of this study was to assess the utility of ultrasound imaging in evaluating subscapularis integrity at specific time points following shoulder arthroplasty, in a blinded fashion. Secondarily, we report on the correlation between the condition of the subscapularis and quality-of-life outcome measures. STUDY DESIGN: Prospective case series. METHODS: Ultrasounds were completed preoperatively and postoperatively at 1 week as well as at 1, 3, and 6 months. Each was read by a single musculoskeletal radiologist and categorized as "intact," "torn," or "unclear." Clinical outcome was evaluated using the Western Ontario Osteoarthritis Shoulder (WOOS) index at these same time points. RESULTS: The final study group consisted of 35 procedures in 33 patients (19 females and 14 males, mean age 66 ± 9 years). Three patients had postoperative subscapularis failures that were confirmed in the operating room at the time of repair. Of 24 sonographs categorized as "unclear" in the postoperative period, the majority (n = 12, 50%) were taken at 1 week. Compared to preoperative scores, patients had lower WOOS scores at 1, 3, and 6 months postoperatively (P < .001). Correlation analysis did not reveal an association between the ultrasound readings and the WOOS scores postoperatively. CONCLUSION: The utility of ultrasound examination of the subscapularis tendon following shoulder arthroplasty is limited by timing and may be most useful when used by the physician within clinical context. Significant improvement was noted in disease-specific quality-of-life scores regardless of the status of the subscapularis tendon as read on ultrasound.

An Anatomic and Biomechanical Comparison of Bankart Repair Configurations.

BACKGROUND: Suture anchor repair for anterior shoulder instability can be performed using a number of different repair techniques, but none has been proven superior in terms of anatomic and biomechanical properties. Purpose/Hypothesis: The purpose was to compare the anatomic footprint coverage and biomechanical characteristics of 4 different Bankart repair techniques: (1) single row with simple sutures, (2) single row with horizontal mattress sutures, (3) double row with sutures, and (4) double row with labral tape. The hypotheses were as follows: (1) double-row techniques would improve the footprint coverage and biomechanical properties compared with single-row techniques, (2) horizontal mattress sutures would increase the footprint coverage compared with simple sutures, and (3) repair techniques with labral tape and sutures would not show different biomechanical properties. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-four fresh-frozen cadaveric specimens were dissected. The native labrum was removed and the footprint marked and measured. Repair for each of the 4 groups was performed, and the uncovered footprint was measured using a 3-dimensional digitizer. The strength of the repair sites was assessed using a servohydraulic testing machine and a digital video system to record load to failure, cyclic displacement, and stiffness. RESULTS: The double-row repair techniques with sutures and labral tape covered 73.4% and 77.0% of the footprint, respectively. These percentages were significantly higher than the footprint coverage achieved by single-row repair techniques using simple sutures (38.1%) and horizontal mattress sutures (32.8%) ( P < .001). The footprint coverage of the simple suture and horizontal mattress suture groups was not significantly different ( P = .44). There were no significant differences in load to failure, cyclic displacement, or stiffness between the single-row and double-row groups or between the simple suture and horizontal mattress suture techniques. Likewise, there was no difference in the biomechanical properties of the double-row repair techniques with sutures versus labral tape. CONCLUSION: Double-row repair techniques provided better coverage of the native footprint of the labrum but did not provide superior biomechanical properties compared with single-row repair techniques. There was no difference in footprint coverage or biomechanical strength between the simple suture and horizontal mattress suture repair techniques. CLINICAL RELEVANCE: Although the double-row repair techniques had no difference in initial strength, they may improve healing in high-risk patients by improving the footprint coverage.

The Effect of Early Range of Motion on Quality of Life, Clinical Outcome, and Repair Integrity After Arthroscopic Rotator Cuff Repair.

PURPOSE: To compare the effect of early versus delayed motion protocols on quality of life, clinical outcomes, and repair integrity in patients who have undergone arthroscopic single-tendon rotator cuff repair. METHODS: This was a prospective, randomized, investigator-blinded clinical trial. Seventy-three patients from a single surgeon's practice who underwent arthroscopic repair of a single-tendon rotator cuff tear were randomized to either an early motion protocol (starting 2 to 3 days after surgery) or a delayed motion protocol (starting 28 days after surgery). The primary outcome measure was the Western Ontario Rotator Cuff index (WORC). Secondary outcome measures included clinical outcome scores, integrity of the repair on 6-month magnetic resonance imaging scans, pain scores, physical examination data, and ultrasonography. Study participants were followed up at 3, 6, and 12 weeks; 6 months; and 1 year postoperatively. RESULTS: There was no statistically significant difference in WORC scores at 6 months (529 ± 472 in delayed group vs 325 ± 400 in early group, P = .08). Mixed-effects analysis indicated the early group maintained lower WORC scores throughout the postoperative period (estimated difference of 191, P = .04). The proportions of patients with tears on the 6-month postoperative magnetic resonance imaging scan were comparable (31% in delayed group vs 34% in early group, P = .78). CONCLUSIONS: There was no difference between the delayed and early motion groups in WORC scores at 6 months after surgery. Early motion was associated with lower WORC scores throughout the postoperative period; however, both groups had a similar trajectory of improvement, suggesting both protocols have the same effect on patient-reported improvement. Although failure rates were similar between the groups, the sample size was not sufficient to support a statement regarding the relation between tear morphology and the rehabilitation protocol. LEVEL OF EVIDENCE: Level II, lesser-quality randomized controlled trial.

Comparison of Time to Recurrence of Instability After Open and Arthroscopic Bankart Repair Techniques.

BACKGROUND: The results of open and arthroscopic instability repairs have been shown to be equivalent in recent literature. PURPOSE: To compare the time to recurrence (TTR) of instability and disease-specific outcome measures in patients undergoing open and arthroscopic Bankart repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients with recurrent traumatic anterior shoulder instability and a Bankart lesion on diagnostic arthroscopy underwent either open Bankart repair (OB) or arthroscopic Bankart and suture capsulorrhaphy (ABSC) using suture anchors. There was a minimum follow-up of 24 months. The primary outcome measures included Western Ontario Shoulder Instability Index (WOSI) score and time to recurrence of instability (dislocation or subluxation). Rowe score, Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and Short Form-12 (SF-12) score were also compared. RESULTS: A total of 82 shoulders in 80 patients (ABSC, n = 58; OB, n = 24) were evaluated at a mean of 39 months postoperatively. There were 4 clinical failures in the OB group (4 dislocations) and 7 clinical failures in the ABSC group (2 dislocations and 5 subluxations; P = .72 vs OB). The mean time to recurrence of postoperative instability was significantly shorter in the ABSC group (12.6 ± 2.7 months) compared with the OB group (34.2 ± 12 months; P = .04). The WOSI score in the OB group (265 ± 48.1) was better but not statistically significantly compared with the ABSC group (449.8 ± 63.8; P = .06). CONCLUSION: The time to recurrence of instability after open Bankart repair is significantly longer compared with arthroscopic Bankart repair. CLINICAL RELEVANCE: Delayed time to recurrence after open Bankart repair suggests that the open technique may be more suited to withstand the high stress and demands of a heavy-duty profession (contact athletes and heavy manual labor).

Anatomic and Biomechanical Comparison of Traditional Bankart Repair With Bone Tunnels and Bankart Repair Utilizing Suture Anchors.

BACKGROUND: Traditional Bankart repair using bone tunnels has a reported failure rate between 0% and 5% in long-term studies. Arthroscopic Bankart repair using suture anchors has become more popular; however, reported failure rates have been cited between 4% and 18%. There have been no satisfactory explanations for the differences in these outcomes. HYPOTHESIS: Bone tunnels will provide increased coverage of the native labral footprint and demonstrate greater load to failure and stiffness and decreased cyclic displacement in biomechanical testing. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-two fresh-frozen cadaveric shoulders were used. For footprint analysis, the labral footprint area was marked and measured using a Microscribe technique in 6 specimens. A 3-suture anchor repair was performed, and the area of the uncovered footprint was measured. This was repeated with traditional bone tunnel repair. For the biomechanical analysis, 8 paired specimens were randomly assigned to bone tunnel or suture anchor repair with the contralateral specimen assigned to the other technique. Each specimen underwent cyclic loading (5-25 N, 1 Hz, 100 cycles) and load to failure (15 mm/min). Displacement was measured using a digitized video recording system. RESULTS: Bankart repair with bone tunnels provided significantly more coverage of the native labral footprint than repair with suture anchors (100% vs 27%, P < .001). Repair with bone tunnels (21.9 ± 8.7 N/mm) showed significantly greater stiffness than suture anchor repair (17.1 ± 3.5 N/mm, P = .032). Mean load to failure and gap formation after cyclic loading were not statistically different between bone tunnel (259 ± 76.8 N, 0.209 ± 0.064 mm) and suture anchor repairs (221.5 ± 59.0 N [P = .071], 0.161 ± 0.51 mm [P = .100]). CONCLUSION: Bankart repair with bone tunnels completely covered the footprint anatomy while suture anchor repair covered less than 30% of the native footprint. Repair using bone tunnels resulted in significantly greater stiffness than repair with suture anchors. Load to failure and gap formation were not significantly different.

Inter-rater agreement of the Goutallier, Patte, and Warner classification scores using preoperative magnetic resonance imaging in patients with rotator cuff tears.

PURPOSE: The purpose of this study was to determine the interobserver reliability of 3 commonly used classification systems in describing preoperative magnetic resonance imaging (MRI) studies of patients undergoing surgery for full-thickness rotator cuff tears. METHODS: Thirty-one patients who underwent arthroscopic rotator cuff repair and had preoperative MRI studies available were selected over a 2-year period. Three board-certified shoulder surgeons independently reviewed these images. Each was instructed in the published method for determining the Patte score on the T2 coronal images, supraspinatus and infraspinatus atrophy on the T1 sagittal images as described by Warner et al., and the Goutallier score of fatty infiltration of the supraspinatus on the T1 coronal/sagittal images. Statistical analysis was then performed to determine the interobserver agreement using the κ statistic, with the level of significance set a priori at P < .01. RESULTS: None of the classification systems studied yielded excellent or high interobserver reliability. The strongest agreement was found with the Patte classification assessing tendon retraction in the frontal plane (κ = 0.58). The Goutallier classification, which grades fatty infiltration of the supraspinatus, showed moderate interobserver agreement (κ = 0.53) when dichotomized into none to mild (grades 0, 1, and 2) and moderate to severe (grades 3 and 4). Muscle atrophy of both the supraspinatus and infraspinatus yielded the worst interobserver reliability, with only 28% agreement. CONCLUSIONS: The Goutallier, Patte, and Warner MRI classification systems for describing rotator cuff tears did not have high interobserver reliability among 3 experienced orthopaedic surgeons. Fatty infiltration of the supraspinatus and tendon retraction in the frontal planes showed only moderate reliability and moderate to high reliability, respectively. These findings have potential implications in the evaluation of the literature regarding the preoperative classification of rotator cuff tears and subsequent treatment algorithms. LEVEL OF EVIDENCE: Level III, diagnostic agreement study with nonconsecutive patients.

A biomechanical analysis of gap formation and failure mechanics of a xenograft-reinforced rotator cuff repair in a cadaveric model.

HYPOTHESIS: Failure rates of rotator cuff repairs are reported to be as high as 90%, in part because of gap formation at the repair site that occurs before healing. The purpose of this study was to evaluate whether the application of an extracellular matrix (ECM) graft (Conexa; Tornier, Edina, MN, USA) to a rotator cuff repair will decrease the gap formation at the tendon-bone interface and increase the ultimate load to failure over control specimens by mechanically sharing load with the repair in a cadaveric model. METHODS: Six pairs of human cadaveric shoulders were used to test ECM-reinforced and unreinforced rotator cuff repairs for repair-site gapping, ultimate load, failure mode, and load-sharing capabilities of the ECM patch under both cyclic and monotonic loading. RESULTS: The gap formation under cyclic loading was reduced by 40% for the reinforced specimens compared with the control group (1.3 ± 0.6 mm vs 2.1 ± 0.5 mm, P < .05) The load at 5-mm gap formation was significantly higher for the reinforced group (389 ± 71 N) compared with the control group (307 ± 33 N) (P < .05). The ultimate load to failure was significantly higher for the ECM-reinforced group compared with the control group: 429 ± 69 N versus 335 ± 57 N (P < .05). The ECM graft was estimated to share 35% of the load applied to the tendon repair. CONCLUSIONS: Application of an ECM graft to a rotator cuff repair decreased tendon gapping and increased load to failure by load sharing in a human rotator cuff repair model.

Human tendon cell response to 7 commercially available extracellular matrix materials: an in vitro study.

PURPOSE: To evaluate the response of human tenocytes in culture to 7 commercially available extracellular matrix (ECM) patches. METHODS: Four samples of each ECM were incubated in human tenocyte cultures by use of standard methods. Cell adhesion, cell proliferation, and cellular production of type I and type III collagen, decorin, and scleraxis were measured for each sample according to established experimental methods. Histologic samples were examined to measure the migration of the tenocytes into the ECM. RESULTS: Tenocytes adhered more to samples of layered submucosal pig intestine than the 6 other ECM materials (P < .002). Tenocytes proliferated more and produced more matrix proteins when cultured on ECM derived from unaltered dermal specimens of human or porcine origin (P < .001). Cells were not seen to have migrated into the matrix of any ECM sample. CONCLUSIONS: Human tenocytes reacted most favorably to dermal ECM samples that were not chemically cross-linked by the manufacturer. Less favorable responses of the human cells were seen when cultured with equine or synthetic ECM, which showed favorable biologic responses in nonhuman models. Cellular migration into the matrix of the ECM is a complex process and cannot be replicated in this model entirely. CLINICAL RELEVANCE: The results of this study suggest that dermal ECM may more favorably react with human tendon tissue than ECM of other origins. This may have great relevance as research continues in the field of augmenting surgical soft-tissue repair.

Biomechanical and radiographic analysis of partial coracoclavicular ligament injuries.

BACKGROUND: A spectrum of acromioclavicular joint injuries may exist between type II acromioclavicular joint disruption (coracoclavicular strain) and type III acromioclavicular joint injuries (coracoclavicular disruption). This may help explain the variability in outcomes seen in patients with type II acromioclavicular injuries. HYPOTHESIS: Injury to either the conoid or trapezoid ligaments would lead to instability of the acromioclavicular joint after complete acromioclavicular joint injury. A secondary hypothesis was that the resulting instability could be recognized with Zanca radiographs. STUDY DESIGN: Controlled laboratory study. METHODS: The acromioclavicular ligaments were sectioned in 40 cadaveric shoulder specimens. Ten intact specimens were loaded to failure to evaluate the normal failure patterns of the coracoclavicular ligaments. Thirty specimens then had either the conoid or trapezoid ligament sectioned after creation of complete acromioclavicular joint injury. Preinjury and postinjury radiographs and stability testing quantified the effect of coracoclavicular joint injury on acromioclavicular joint stability. RESULTS: During failure testing, the conoid always failed first. Sectioning of the conoid led to significant increases in posterior and superior displacement on radiographs and with materials testing. Sectioning of the trapezoid led to significant increases in posterior displacement for materials testing and superior displacement on radiographs. CONCLUSION: Sectioning of the acromioclavicular ligaments in conjunction with partial disruption of the coracoclavicular ligament complex led to significant changes in both radiographic and mechanical measures of acromioclavicular stability. The conoid fails first when a load is applied to the coracoclavicular complex in a superior direction. CLINICAL RELEVANCE: Zanca radiograph may detect incomplete injury to the coracoclavicular ligaments associated with acromioclavicular disruption.

The use of intra-articular hylan G-F 20 in the treatment of symptomatic osteoarthritis of the shoulder: a preliminary study.

BACKGROUND: While hylan G-F 20 is an approved therapy for the treatment of knee osteoarthritis, there are few reports of its use in shoulder osteoarthritis. HYPOTHESIS: Hylan G-F 20 can reduce pain and improve function in patients with glenohumeral osteoarthritis. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty consecutive patients with idiopathic glenohumeral osteoarthritis who failed to respond to standard conservative measures were enrolled. Patients received 3 weekly intra-articular hylan G-F 20 injections in their affected shoulder and completed a visual analog scale for pain, the UCLA score, and the Simple Shoulder Test at baseline and at 1, 3, and 6 months after the third injection. RESULTS: Of the 30 patients, 3 withdrew during the washout period before treatment; the remaining patients (17 men and 10 women) had an average age of 62 years. The mean baseline visual analog scale score was 54, UCLA score was 15.7, and Simple Shoulder Test score was 5.7 (of 12 possible "yes" responses). At the 6-month follow-up, hylan G-F 20 significantly improved visual analog scale (mean 30, P < .001), UCLA (mean 24, P < .001), and Simple Shoulder Test (7.6 "yes" responses, P < .001) scores. More patients slept comfortably after treatment (56%) versus before treatment (15%). Nine patients had a visual analog scale improvement >40 points after 6 months. No device-related adverse events were observed. CONCLUSION: Hylan G-F 20 may have a beneficial therapeutic effect on some symptomatic patients with glenohumeral osteoarthritis.