Subscapularis integrity and patient-reported outcomes after total shoulder arthroplasty: does time to mobilization matter?

BackgroundMaintaining subscapularis integrity may be a significant variable in optimizing patient outcomes following total shoulder arthroplasty. Multiple factors have been reported in orthopedic literature as a contributor to subscapularis failure. Most surgeons follow a protocol that calls for some period of immobilization. However, time of mobilization and rehabilitation is still a point of discussion, as no consensus currently exists. Our study aimed to compare postoperative outcomes of patients who followed a traditional immobilization protocol to those who underwent rapid mobilization.MethodsA single-blinded, randomized controlled clinical trial was conducted between December 2015 and May 2018. Patients were prospectively enrolled and randomized using a 1:1 random allocation into 2 groups: prolonged immobilization for 4 weeks or rapid mobilization at 1 week. All cases were performed by a single, fellowship-trained shoulder and elbow surgeon with standard pre- and intra-operative protocols. Metallic markers were used to mark the musculotendinous junction of the subscapularis tendon. Postoperatively, patients were notified of their randomization assignment and provided detailed instructions on when to begin mobilization. Patient-reported outcome measures, physical examination, and radiologic assessments were evaluated preoperatively and at 6 weeks, 3 months, 6 months, 12 months, and 32 months postoperatively. Our primary outcome was clinical and radiographic subscapularis failure.ResultsForty-three patients consented with 40 procedures randomized to the 2 cohorts. Among these 40 procedures, there were up to 235 follow-up visits over 32 months. Of the 40 procedures, 2 (5.0%) were complicated with a postoperative tear, both associated with a weak belly test and radiographically confirmed with medialization of the surrogate markers on plain radiographs. No statistically significant difference was seen between the prolonged immobilization and rapid mobilization groups for American Shoulder and Elbow Surgeons shoulder score, Constant Shoulder Score, Visual Analog Scale Score, Simple Shoulder Test Score, and Short-Form Surveys at any follow-up point (all P > .05). On evaluating active forward flexion and external rotation, no statistically significant difference was also appreciated between the 2 groups at any time point (all P > .05).DiscussionOur randomized control trial compared currently accepted protocols to immobilize for 4 weeks following total shoulder arthroplasty using a peel to early mobilization at 1 week and found no statistical and clinical difference in outcomes. However, further study is necessary before a consensus recommendation can be made.     

Is there an association between operative time and length of stay after shoulder arthroplasty?

BackgroundUnderstanding and reducing the length of stay (LOS) after orthopedic procedures has become essential with the implementation of bundled payment reimbursement models. Previous small cohort investigations have identified the risk factors for increased LOS after primary shoulder arthroplasty, such as renal insufficiency, cardiac disease, American Society of Anesthesiologists classification, and operative time >174 minutes.MethodsThe National Surgical Quality Improvement Program database was queried for all primary shoulder arthroplasty cases (Current Procedural Terminology code 23472) between 2008 and 2016, yielding 14,449 total patients. Univariate analysis using linear regression and independent sample t-tests were used to determine associations between LOS and the study variables. The outcome of interest was the association between operative time and LOS using multivariate regression models.ResultsOverall, the mean (±standard deviation) LOS was 2 (±2) days. Simple linear regression demonstrated age, gender, and operative time had significant positive correlations with the length of hospital stay (P < .001). Multivariate analysis showed that after adjusting for patient factors (age, gender, body mass index, and American Society of Anesthesiologists), longer operative times had significant associations with longer hospital stays (β = 0.109, standard error < 0.001, P value < .001).ConclusionThe results demonstrate LOS is associated with age, gender, and operative time. Operative time had the greatest effect on LOS after multivariate analysis. This study highlights the importance of operating room efficiency on healthcare quality and economics after shoulder arthroplasty.Level of evidenceLevel IV; Retrospective Case Series     

Using inertial measurement units to quantify shoulder elevation after reverse total shoulder arthroplasty: a pilot study comparing goniometric measures captured clinically to inertial measures captured ‘in-the-wild’

BackgroundReverse total shoulder arthroplasty (rTSA) is utilized for a variety of indications, but most commonly for patients with rotator cuff arthropathy. This procedure reduces pain, improves satisfaction, and increases clinically measured range of motion (ROM). However, traditional clinical ROM measurements captured via goniometer may not accurately represent ‘real-world’ utilization of ROM. In contrast, inertial measurement units (IMUs) are useful for establishing ROM outside the clinical setting. We sought to measure ‘real-world’ ROM after rTSA using IMUs.MethodsA previously validated IMU-based method for continuously capturing shoulder elevation was used to assess 10 individuals receiving rTSA (1M, 82 ± 5 years) and compared to a previously captured 10 healthy individuals (4M, 69 ± 20 years) without shoulder dysfunction. Control subject data were previously collected over 1 week of continuous use. Patients undergoing rTSA donned sensors for 1 week pre-rTSA, 6 weeks at 3 months post-rTSA following clearance to perform active-independent ROM, and 1 week at 1 year and 2 years post-rTSA. Shoulder elevation was computed continuously each day. Daily continuous elevation was broken into 5° angle ‘bins’ (eg, 0-5°, 5-10°, etc.) and converted to percentage of the total day. IMU-based outcome measures were ROM binned percent (as described previously) and maximum/average elevation each week. Clinical goniometric ROM and patient-reported outcome measures were also captured.ResultsNo differences existed between patient and healthy control demographics. While patients showed improvement in American Shoulder and Elbow Surgeon (ASES) score, pain score, and goniometric ROM, IMU-based average and maximum elevation were equal between control subjects and patients both pre- and post-rTSA. The percent of time spent above 90° was equal between cohorts pre-rTSA, rose significantly at 3 months post-rTSA, and returned to preoperative levels thereafter.DiscussionAlthough pain, satisfaction, and ROM measured clinically may improve following rTSA, real-world utilization of improved ROM was not seen herein. Improvements during the acute rehabilitation phase may be transient, indicating longer or more specific rehabilitation protocols are necessary to see chronic improvements in post-rTSA movement patterns.     

Radiographic outcomes of patients undergoing reverse shoulder arthroplasty using inlay versus onlay components: is there really a difference?

IntroductionAchieving soft tissue tension in RSA occurs by displacement of the humerus from the glenoid. We compared the lateral and inferior humeral displacement of two RSA systems radiographically. Each system utilized a humeral implant with a 135-degree neck-shaft angle and offered lateralized glenospheres. One had an onlay component and the other an inlay. Our primary hypothesis was that an alteration of surgical technique would negate the differences in their geometries radiographically. Secondarily, we sought to determine if a difference in complications or revisions occurred with these different designs.MethodsTwo hundred and eleven patients underwent RSA by a single surgeon with either an inlay or onlay prosthesis over a 2-year period. A true AP Grashey radiograph was utilized to measure: 1) Glenohumeral offset (GHO); 2) Acromiohumeral distance (AHD); 3) Pivot point (PP); 4) Humeral head cut surrogate (HHC) and 5) Humeral Socket Depth (HSD). Complications recorded included postoperative acromial fractures, revision for any reason, instability, and infections.ResultsThere was no significant difference in GHO or AHD between the two groups. There was a difference in PP and HHC between the groups (P < .001). The onlay group had an HHC 1.8 mm larger than inlay. Of the inlay group patients, 66% had their humeral tray placed above the level of the humeral osteotomy.DiscussionA larger HHC in the onlay group and implanting the inlay above the humeral osteotomy negates differences in AHD and GHO.Level of evidenceLevel III; Retrospective Comparative Study