How internal rotation is measured in reverse total shoulder arthroplasty: a systematic review of the literature

Predictive factors influencing internal rotation following reverse total shoulder arthroplasty

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is increasingly used as a treatment modality for various pathologies. The purpose of this review is to identify preoperative risk factors associated with loss of internal rotation (IR) after RTSA.

METHODS

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Ovid MEDLINE, Ovid Embase, and Scopus were queried. The inclusion criteria were as follows: articles in English language, minimum 1-year follow-up postoperatively, study published after 2012, a minimum of 10 patients in a series, RTSA surgery for any indication, and explicitly reported IR. The exclusion criteria were as follows: articles whose full text was unavailable or that were unable to be translated to English language, a follow-up of less than 1 year, case reports or series of less than 10 cases, review articles, studies in which tendon transfers were performed at the time of surgery, procedures that were not RTSA, and studies in which the range of motion in IR was not reported.

RESULTS

The search yielded 3792 titles, and 1497 duplicate records were removed before screening. Ultimately, 16 studies met the inclusion criteria with a total of 5124 patients who underwent RTSA. Three studies found that poor preoperative functional IR served as a significant risk factor for poor postoperative IR. Eight studies addressed the impact of subscapularis, with 4 reporting no difference in IR based on subscapularis repair and 4 reporting significant improvements with subscapularis repair. Among studies with sufficient power, BMI was found to be inversely correlated with degree of IR after RTSA. Preoperative opioid use was found to negatively affect IR. Other studies showed that glenoid retroversion, component lateralization, and individualized component positioning affected postoperative IR.

CONCLUSIONS

This study found that preoperative IR, individualized implant version, preoperative opioid use, increased body mass index and increased glenoid lateralization were all found to have a significant impact on IR after RTSA. Studies that analyzed the impact of subscapularis repair reported conflicting results.

Influence of lateralized versus medialized reverse shoulder arthroplasty design on external and internal rotation: a systematic review and meta-analysis

BACKGROUND

Restoration of external (ER) and internal rotation (IR) after Grammont-style reverse shoulder arthroplasty (RSA) is often unreliable. The purpose of this systematic review was to evaluate the influence of RSA medio-lateral offset and subscapularis repair on axial rotation after RSA.

METHODS

We conducted a systematic review of studies evaluating axial rotation (ER, IR, or both) after RSA with a defined implant design. Medio-lateral implant classification was adopted from Werthel et al. Meta-analysis was conducted using a random-effects model.

RESULTS

Thirty-two studies reporting 2,233 RSAs were included (mean patient age, 72.5 years; follow-up, 43 months; 64% female). The subscapularis was repaired in 91% (n=2,032) of shoulders and did not differ based on global implant lateralization (91% for both, P=0.602). On meta-analysis, globally lateralized implants achieved greater postoperative ER (40° [36°-44°] vs. 27° [22°-32°], P<0.001) and postoperative improvement in ER (20° [15°-26°] vs. 10° [5°-15°], P<0.001). Lateralized implants with subscapularis repair or medialized implants without subscapularis repair had significantly greater postoperative ER and postoperative improvement in ER compared to globally medialized implants with subscapularis repair (P<0.001 for both). Mean postoperative IR was reported in 56% (n=18) of studies and achieved the minimum necessary IR in 51% of lateralized (n=325, 5 cohorts) versus 36% (n=177, 5 cohorts) of medialized implants.

CONCLUSIONS

Lateralized RSA produces superior axial rotation compared to medialized RSA. Lateralized RSA with subscapularis repair and medialized RSA without subscapularis repair provide greater axial rotation compared to medialized RSA with subscapularis repair. Level of evidence: 2A.

Understanding overall shoulder function and health: the value of specific quantitative vs. qualitative shoulder range of motion on patient-reported outcome measures

HYPOTHESIS AND BACKGROUND

It is known that, though widely used, shoulder range of motion (ROM) measurements are not standardized and have a high rate of intra- and interobserver differences. Particularly, the inconsistency in quantitative and qualitative measurements and their relationship to patient-reported outcome measures (PROMs) make shoulder health difficult to determine.

METHODS

This was a prospective study of 147 patients who presented with a chief complaint of shoulder pain to the orthopedic sports medicine and shoulder clinic of a single fellowship-trained surgeon. Measured by 1 examiner, quantitative ROM measurements were taken with a goniometer and qualitative ROM measured by the anatomic level that the patient could reach. The following PROMs were used as well: American Shoulder and Elbow Surgeons shoulder score, Single Assessment Numeric Evaluation, Shoulder Pain and Disability Index, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand questionnaire, 12-Item Short Form Health Survey, and Patient-Reported Outcomes Measurement Information System pain interference short form 6a (PROMIS 6a). Statistical analysis was performed with SPSS using the Pearson correlation and 2-sample t test. The Benjamini-Hochberg correction was used to determine the P value at which statistical significance was reached to correct for multiple comparisons.

RESULTS

Qualitative internal rotation (IR) (the hand behind back reach test) and qualitative forward flexion (FF) correlated with all goniometer angle measurements and PROMs (both shoulder and general health scores). These qualitative measures proved to be an appropriate proxy for IR and FF goniometer measurements. Qualitative external rotation (ER) was not a good substitute for quantitative ER measurement. Quantitative ER correlated with all PROMs. As ROM increased when measured by quantitative ER, qualitative IR, and qualitative FF, shoulder and general health PROMs incrementally increased as well.

DISCUSSION/CONCLUSIONS

Qualitative IR measurement, the hand-behind-back reach test, is an adequate substitution for IR goniometer angle as well as a strong representation of global shoulder ROM, shoulder health, and general health while factoring in patient age. Qualitative FF measurement is also an appropriate proxy for quantitative FF and represents global shoulder and general health without factoring in age. Quantitative ER, via goniometer angle, is a better assessment of the shoulder than qualitative ER and is a representation of overall shoulder and general health. We recommend the use of quantitative ER, qualitative IR, and qualitative FF measurements to best understand a patient's overall shoulder health and its impact on their overall health.

Prevalence and predisposing factors of neuropathic pain in patients with rotator cuff tears

BACKGROUND

The management of pain in patients with rotator cuff tears can be challenging. Neuropathic pain is reportedly associated with pain occurrence in musculoskeletal diseases. However, to date, few studies have reported on the prevalence of neuropathic pain in patients with rotator cuff tears or identified the factors associated with neuropathic pain in a multicenter study.

METHODS

A total of 391 patients (205 males and 186 females; median age, 67.7 years; range, 27-92 years) with rotator cuff tears were included in this study. The prevalence of neuropathic pain in rotator cuff tears was investigated using the Japanese version of the painDETECT questionnaire for all patients. In addition, factors significantly associated with the occurrence of neuropathic pain were examined using multivariate logistic regression analysis.

RESULTS

Twenty-eight patients (7.2%) were classified into the neuropathic pain group (score ≥19), 97 (24.8%) into the uncertainty regarding neuropathy group (score 13-18), and 266 (68.0%) into the nociceptive pain group (score ≤12). According to the multivariate logistic regression analysis, the independent predictors of neuropathic pain were the VAS score (most severe pain during the past 4 weeks; odds ratio, 1.55; 95% confidence interval [CI], 1.23-2.09) and UCLA shoulder score (odds ratio, 0.81; 95% CI, 0.65-0.97).

CONCLUSIONS

Based on the study findings, the prevalence of neuropathic pain in patients with rotator cuff tear was 7.2%. It is important to investigate the presence or absence of neuropathic pain when treating patients with painful rotator cuff tears, because neuropathy associated with rotator cuff tears may adversely affect patient outcomes.

Discordance between patient-reported and objectively measured internal rotation after reverse shoulder arthroplasty

BACKGROUND

Patient satisfaction after reverse shoulder arthroplasty (RSA) partly relies on restoring functional internal rotation (IR). Although postoperative assessment of IR includes objective appraisal by the surgeon and subjective report from the patient, these evaluations may not vary together uniformly. We assessed the relationship between objective, surgeon-reported assessments of IR and subjective, patient-reported ability to perform IR-related activities of daily living (IRADLs).

METHODS

Our institutional shoulder arthroplasty database was queried for patients undergoing primary RSA with a medialized-glenoid lateralized-humerus design between 2007-2019 and minimum 2-year follow-up. Patients who were wheelchair bound or had a preoperative diagnosis of infection, fracture, and tumor were excluded. Objective IR was measured to the highest vertebral level reached with the thumb. Subjective IR was reported based on patients' rating (normal, slightly difficult, very difficult, or unable) of their ability to perform 4 IRADLs (tuck in shirt with hand behind back, wash back or fasten bra, personal hygiene, and remove object from back pocket). Objective IR was assessed preoperatively and at latest follow-up and reported as median and interquartile ranges.

RESULTS

A total of 443 patients were included (52% female) at a mean follow-up of 4.4 ± 2.3 years. Objective IR improved pre- to postoperatively from L4-L5 (buttocks to L1-L3) to L1-L3 (L4-L5 to T8-T12) (P < .001). Preoperatively reported IRADLs of "very difficult" or "unable" significantly decreased postoperatively for all IRADLs (P ≤ .004) except those unable to perform personal hygiene (3.2% vs. 1.8%, P > .99). The proportions of patients who improved, maintained, and lost objective and subjective IR was similar between IRADLs; 14%-20% improved objective IR but lost or maintained subjective IR and 19%-21% lost or maintained the same objective IR but improved subjective IR depending on the specific IRADL assessed. When ability to perform IRADLs improved postoperatively, objective IR also increased (P < .001). In contrast, when subjective IRADLs worsened postoperatively, objective IR did not significantly worsen for 2 of 4 IRADLs assessed. When examining patients who reported no change in ability to perform IRADLs pre- vs. postoperatively, statistically significant increases in objective IR were found for 3 of 4 IRADLs assessed.

CONCLUSIONS

Objective improvement in IR parallels improvements in subjective functional gains uniformly. However, in patients with worse or equivalent IR, the ability to perform IRADLs postoperatively does not uniformly correlate with objective IR. When attempting to elucidate how surgeons can ensure patients will have sufficient IR after RSA, future investigations may need to use patient-reported ability to perform IRADLs as the primary outcome measure rather than objective measures of IR.

Outcomes of Reverse Total Shoulder Arthroplasty with Latissimus Dorsi Tendon Transfer for External Rotation Deficit: A Systematic Review and Meta-Analysis

BACKGROUND

Latissimus dorsi transfer (LDT) has been purported to restore motion in patients undergoing reverse shoulder arthroplasty (RSA) who have preoperative combined loss of forward elevation (FE) and external rotation (ER). This systematic review summarizes the available evidence for the functional outcomes and complications after RSA with LDT. Furthermore, the effect of implant design and whether a concomitant teres major transfer (TMT) was performed were studied.

METHODS

A systematic review was performed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles reporting on LDT with RSA to restore ER. Our primary outcomes were ER, FE, Constant score, and complication incidence. Secondarily, we reported postoperative internal rotation (IR) and compared ER, FE, and Constant score based on lateralized versus medialized global implant design and whether concomitant TMT was performed.

RESULTS

Nineteen studies were evaluated; functional outcomes were assessed in 16 articles reporting on 258 RSAs (123 LDT, 135 LDT-TMT). Surgical indication was most commonly cuff tear arthropathy and massive irreparable cuff tear. Mean ER was -12° preoperatively and 25° postoperatively, FE was 72° preoperatively and 141° postoperatively. Mean postoperative Constant score was 65. Of 138 patients (8 studies) describing IR, only 25% reported a mean postoperative IR ≥L3. Subanalysis comparing lateralized versus medialized implants and whether TMT was concomitantly performed demonstrated no significant difference in postoperative ER, FE, and Constant score, nor preoperative to postoperative improvement in ER and FE. The complication rate was 14.1% (of 291 shoulders from 16 studies), including tear in the tendon transfer (n = 3), revision tendon repair (n = 1), nerve-related complication (n = 9), and dislocation (n = 9).

CONCLUSIONS

RSA with LDT is a reliable option to restore motion, with a comparable complication rate with standard RSA. The use of medialized versus lateralized implants and whether the TM was concomitantly transferred may not influence clinical outcomes.

LEVEL OF EVIDENCE

Level IV. See Instructions for Authors for a complete description of levels of evidence.

High and low performers in internal rotation after reverse total shoulder arthroplasty: a biplane fluoroscopic study

BACKGROUND

Internal rotation in adduction is often limited after reverse total shoulder arthroplasty (rTSA), but the origins of this functional deficit are unclear. Few studies have directly compared individuals who can and cannot perform internal rotation in adduction. Little data on underlying 3D humerothoracic, scapulothoracic, and glenohumeral joint relationships in these patients are available.

METHODS

Individuals >1-year postoperative to rTSA were imaged with biplane fluoroscopy in resting neutral and internal rotation in adduction poses. Subjects could either perform internal rotation in adduction with their hand at T12 or higher (high, N = 7), or below the hip pocket (low, N = 8). Demographics, the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and scapular notching grade were recorded. Joint orientation angles were derived from model-based markerless tracking of the scapula and humerus relative to the torso. The 3D implant models were aligned to preoperative computed tomography models to evaluate bone-implant impingement.

RESULTS

The Simple Shoulder Test was highest in the high group (11 ± 1 vs. 9 ± 2, P = .019). Two subjects per group had scapular notching (grades 1 and 2), and 3 high group and 4 low group subjects had impingement below the glenoid. In the neutral pose, the scapula had 7° more upward rotation in the high group (P = .100), and the low group demonstrated 9° more posterior tilt (P = .017) and 14° more glenohumeral elevation (P = .047). In the internal rotation pose, axial rotation was >45° higher in the high group (P ≤ .008) and the low group again had 11° more glenohumeral elevation (P = .058). Large rotational differences within subject groups arose from a combination of differences in the resting neutral and maximum internal rotation in adduction poses, not only the terminal arm position.

CONCLUSIONS

Individuals who were able to perform high internal rotation in adduction after rTSA demonstrated differences in joint orientation and anatomic biases versus patients with low internal rotation. The high rotation group had 7° more resting scapular upward rotation and used a 15°-30° change in scapular tilt to perform internal rotation in adduction versus patients in the low group. The combination of altered resting scapular posture and restricted scapulothoracic range of motion could prohibit glenohumeral rotation required to reach internal rotation in adduction. In addition, inter-patient variation in humeral torsion may contribute substantially to postoperative internal rotation differences. These data point toward modifiable implant design and placement factors, as well as foci for physical therapy to strengthen and mobilize the scapula and glenohumeral joint in response to rTSA surgery.

Computer-assisted analysis of functional internal rotation after reverse total shoulder arthroplasty: implications for component choice and orientation

PURPOSE

Functional internal rotation (IR) is a combination of extension and IR. It is clinically often limited after reverse total shoulder arthroplasty (RTSA) either due to loss of extension or IR in extension. It was the purpose of this study to determine the ideal in-vitro combination of glenoid and humeral components to achieve impingement-free functional IR.

METHODS

RTSA components were virtually implanted into a normal scapula (previously established with a statistical shape model) and into a corresponding humerus using a computer planning program (CASPA). Baseline glenoid configuration consisted of a 28 mm baseplate placed flush with the posteroinferior glenoid rim, a baseplate inclination angle of 96° (relative to the supraspinatus fossa) and a 36 mm standard glenosphere. Baseline humeral configuration consisted of a 12 mm humeral stem, a metaphysis with a neck shaft angle (NSA) of 155° (+ 6 mm medial offset), anatomic torsion of -20° and a symmetric PE inlay (36mmx0mm). Additional configurations with different humeral torsion (-20°, + 10°), NSA (135°, 145°, 155°), baseplate position, diameter, lateralization and inclination were tested. Glenohumeral extension of 5, 10, 20, and 40° was performed first, followed by IR of 20, 40, and 60° with the arm in extension of 40°-the value previously identified as necessary for satisfactory clinical functional IR. The different component combinations were taken through simulated ROM and the impingement volume (mm³) was recorded. Furthermore, the occurrence of impingement was read out in 5° motion increments.

RESULTS

In all cases where impingement occurred, it occurred between the PE inlay and the posterior glenoid rim. Only in 11 of 36 combinations full functional IR was possible without impingement. Anterosuperior baseplate positioning showed the highest impingement volume with every combination of NSA and torsion. A posteroinferiorly positioned 26 mm baseplate resulting in an additional 2 mm of inferior overhang as well as 6 mm baseplate lateralization offered the best impingement-free functional IR (5/6 combinations without impingement). Low impingement potential resulted from a combination of NSA 135° and + 10° torsion (4/6 combinations without impingement), followed by NSA 135° and -20° torsion (3/6 combinations without impingement) regardless of glenoid setup.

CONCLUSION

The largest impingement-free functional IRs resulted from combining a posteroinferior baseplate position, a greater inferior glenosphere overhang, 90° of baseplate inclination angle, 6 mm glenosphere lateralization with respect to baseline setup, a lower NSA and antetorsion of the humeral component. Surgeons can employ and combine these implant configurations to achieve and improve functional IR when planning and performing RTSA.

LEVEL OF EVIDENCE

Basic Science Study, Biomechanics.

Accuracy of Blueprint software in predicting range of motion 1 year after reverse total shoulder arthroplasty

HYPOTHESIS AND BACKGROUND

Blueprint 3-dimensional computed tomography software has a functionality that predicts impingement-free range of motion (ROM) with determination of the limits of ROM at which bone and/or prosthetic impingement occurs. To our knowledge, only 1 previously published study has assessed the ability of Blueprint software to predict actual postoperative ROM after reverse total shoulder arthroplasty (RTSA). The hypotheses of this study were that (1) mean Blueprint-predicted impingement-free ROM would be statistically similar to the mean actual ROM 1 year after RTSA and (2) there would be a correlation between Blueprint-predicted impingement-free ROM and the actual ROM 1 year after RTSA.

MATERIALS AND METHODS

A retrospective review of patients who underwent Blueprint planning prior to undergoing RTSA from March 2017 through May 2021 was performed. At 1-year follow-up, flexion, external rotation at the side, abduction, external rotation in the abducted position, internal rotation in the abducted position, and internal rotation behind the back were measured. The preoperatively predicted flexion, extension, abduction, external rotation, and internal rotation were recorded using Blueprint software. The group 1 analysis examined the predicted vs. actual ROM of all 127 patients regardless of whether intraoperative component modifications were made. The group 2 analysis examined the predicted vs. actual ROM of only the patients who did not undergo intraoperative changes that would affect the preoperative ROM prediction (n = 97). The group 3 analysis examined the predicted vs. actual ROM of group 2 combined with the 30 patients who underwent post hoc Blueprint planning modifications to account for the changes made intraoperatively (combined sample size of 127).

RESULTS

Of the 141 patients, 127 (90%) were available for 1-year follow-up. When the mean values of all 3 groups were examined, the actual ROM and predicted ROM were statistically significantly different (P < .0001) for flexion, external rotation, abduction, abduction-external rotation, and abduction-internal rotation. In group 1, a very weak or poor correlation was found between predicted internal rotation and actual abducted internal rotation (r = 0.19, P = .04). For all other ROM metrics in groups 1, 2, and 3, there were no correlations between predicted and actual ROM (P ≥ .07).

CONCLUSIONS

In its current state, preoperative Blueprint 3-dimensional computed tomography planning software is unable to accurately predict ROM 1 year after RTSA.

A pilot-study focusing on internal rotation after reverse total shoulder arthroplasty using the Activities of Daily Living which require Internal Rotation (ADLIR) score

Background

Loss of internal rotation remains an issue after reverse total shoulder arthroplasty (RTSA). Our goal is to define the expected functional internal rotation after RTSA using the Activities of Daily Living which require Internal Rotation (ADLIR) score in a homogenous population of patients treated with RTSA.

Methods

35 patients with a minimum follow-up of two years after RTSA were evaluated using the ADLIR and Constant-Murley questionnaires. A correlation between the ADLIR and Constant score was investigated and the internal validity of the ADLIR score used in a RTSA patient population was measured using Cronbach's alpha coefficient. The impact of internal rotation on the total rotational arc of motion was defined.

Results

Excellent results were recorded for both the Constant score (79 ± 18) and ADLIR score (88 ± 16). Pearson's correlation coefficient was r = 0,84 (p-value <0,001). The ADLIR score showed a high reliability for all questions.

Conclusions

The ADLIR score has proven to be a useful addition in the post-operative evaluation of patients treated with RTSA. Further studies are needed to investigate the evolution of the ADLIR score from pre- to postoperatively in order to determine the clinical and predictive value of this score.

Level of evidence

Level IV - Observational study.

Factors associated with improvement or loss of internal rotation after reverse shoulder arthroplasty

BACKGROUND

Internal rotation (IR) with reverse total shoulder arthroplasty (rTSA) can be unpredictable. Identifying the factors associated with loss of or improved IR could aid preoperative patient counseling. This study quantifies the change in IR experienced by rTSA patients with nonfracture indications and identifies the patient, implant, and operative factors associated with IR loss or gain at 2-year minimum follow-up.

METHODS

A total of 1978 primary rTSA patients were analyzed from an international database of a single rTSA prosthesis to quantify IR at 2 years' minimum follow-up. rTSA patients were divided into 2 cohorts based on their preoperative IR score, with group 1 patients having less active IR as defined by a preoperative IR score ≤3 and group 2 patients having greater active IR as defined by a preoperative IR score ≥4 (ie, L5 or higher). For both group 1 and 2 patients, univariate and multivariate analyses were performed to quantify the risk factors associated with IR loss after rTSA.

RESULTS

Overall, 58.9% of rTSA patients experienced IR improvement and 17.0% lost IR after rTSA. The occurrence of IR loss or gain was dependent on preoperative IR score, as 73.2% of group 1 patients improved IR and only 40.1% of group 2 patients improved IR, whereas 31.0% of group 2 patients lost IR and only 6.3% of group 1 patients lost IR after rTSA. Numerous risk factors for IR loss were identified. For group 1 patients, male sex (P = .004, odds ratio [OR] = 2.056), tobacco usage (P = .004, OR = 0.348), larger humeral stem diameter (P = .008, OR = 0.852), and not having subscapularis repaired (P = .002, OR = 2.654) were significant risk factors for IR loss. For group 2 patients, male sex (P = .005, OR = 1.656), higher body mass index (P = .002, OR = 0.946), a diagnosis other than osteoarthritis (P < .001, OR = 2.189), nonaugmented baseplate usage (P < .001, OR = 2.116), and not having subscapularis repaired (P < .001, OR = 3.052) were significant risk factors for IR loss.

CONCLUSION

The majority of patients improve IR after rTSA in the nonfracture setting. rTSA patients with substantial IR prior to surgery had a greater probability for losing IR compared to patients with poor preoperative IR. Numerous risk factors for IR loss were identified; these risk factors are useful for counseling patients considering rTSA, as some patients are more likely to lose IR than others.

Accelerated versus standard physical therapy in patients with transtendinous rotator cuff repair: a propensity-matched cohort study

BACKGROUND

Partial-thickness rotator cuff tears that remain symptomatic despite conservative management can be repaired operatively through a transtendinous approach. Although transtendinous repairs have been linked to superior long-term biomechanical outcomes compared with other surgical techniques, they are classically associated with early postoperative stiffness and a slower rate of recovery.

PURPOSE

To examine the impact of expediting the physical therapy (PT) regimen after transtendinous repair on postoperative range of motion and complications.

METHODS

The first 61 patients to receive accelerated PT after transtendinous repair were compared with a historical cohort of 61 patients who underwent standard postoperative management. The patients were propensity matched on age, sex, smoking status, and biceps procedure performed at the time of rotator cuff repair. Primary outcome measures included active range of motion (AROM) in forward flexion, abduction, external rotation, and internal rotation at 2 weeks, 6 weeks, 3 months, and 6 months postoperatively. Secondary outcome measures included development of severe stiffness or symptomatic rotator cuff retear at 1-year follow-up. Patients with full-thickness tears and those undergoing revision surgery or tear-completion and repair were excluded.

RESULTS

The accelerated PT cohort showed significantly increased AROM at 6 weeks and 3 months postoperatively. At 6 weeks, AROM in forward flexion (137.0° vs. 114.9°; P < .001), abduction (126.1° vs. 105.3°; P = .009), and external rotation (51.7° vs. 36.5°; P = .005) were all significantly higher in the accelerated PT cohort. A similar increase was seen at 3 months, with superior forward flexion (147.5° vs. 134.0°; P = .01) and external rotation (57.7° vs. 44.0°; P = .008) in patients who received accelerated PT. Severe postoperative stiffness was significantly less common in the accelerated PT cohort (3.3% vs. 18.0%; P = .02), and there were no symptomatic retears (0.00%) in the accelerated PT cohort as compared with 1 symptomatic retear (1.64%) in the standard PT cohort (P = 1.00).

CONCLUSION

Accelerated PT after transtendinous rotator cuff repair is associated with significant improvement in AROM at 6 weeks and 3 months postoperatively. Further, the early motion may help obviate the development of severe postoperative stiffness without any evidence of higher rotator cuff retear rates.

LEVEL OF EVIDENCE

Level III; Retrospective Cohort Comparison; Treatment Study.

Using machine learning to predict internal rotation after anatomic and reverse total shoulder arthroplasty

BACKGROUND

Improvement in internal rotation (IR) after anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty is difficult to predict, with rTSA patients experiencing greater variability and more limited IR improvements than aTSA patients. The purpose of this study is to quantify and compare the IR score for aTSA and rTSA patients and create supervised machine learning that predicts IR after aTSA and rTSA at multiple postoperative time points.

METHODS

Clinical data from 2270 aTSA and 4198 rTSA patients were analyzed using 3 supervised machine learning techniques to create predictive models for internal rotation as measured by the IR score at 6 postoperative time points. Predictions were performed using the full input feature set and 2 minimal input feature sets. The mean absolute error (MAE) quantified the difference between actual and predicted IR scores for each model at each time point. The predictive accuracy of the XGBoost algorithm was also quantified by its ability to distinguish which patients would achieve clinical improvement greater than the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient satisfaction thresholds for IR score at 2-3 years after surgery.

RESULTS

rTSA patients had significantly lower mean IR scores and significantly less mean IR score improvement than aTSA patients at each postoperative time point. Both aTSA and rTSA patients experienced significant improvements in their ability to perform activities of daily living (ADLs); however, aTSA patients were significantly more likely to perform these ADLs. Using a minimal feature set of preoperative inputs, our machine learning algorithms had equivalent accuracy when predicting IR score for both aTSA (0.92-1.18 MAE) and rTSA (1.03-1.25 MAE) from 3 months to >5 years after surgery. Furthermore, these predictive algorithms identified with 90% accuracy for aTSA and 85% accuracy for rTSA which patients will achieve MCID IR score improvement and predicted with 85% accuracy for aTSA patients and 77% accuracy for rTSA which patients will achieve SCB IR score improvement at 2-3 years after surgery.

DISCUSSION

Our machine learning study demonstrates that active internal rotation can be accurately predicted after aTSA and rTSA at multiple postoperative time points using a minimal feature set of preoperative inputs. These predictive algorithms accurately identified which patients will, and will not, achieve clinical improvement in IR score that exceeds the MCID and SCB patient satisfaction thresholds.

Perioperative Clopidogrel (Plavix®) Continuation in Shoulder Arthroplasty: Approach Cautiously

Background

Methods

Results

Conclusion

Relationship between postoperative integrity of subscapularis tendon and functional outcome in reverse shoulder arthroplasty

HYPOTHESIS AND BACKGROUND

The role of the subscapularis in reverse shoulder arthroplasty (RSA) remains controversial. Studies have shown that subscapularis repair has no significant influence on the functional outcomes of patients. However, few studies have assessed the postoperative integrity of the subscapularis tendon after RSA. The aims of this study were to investigate the postoperative healing of the subscapularis after RSA via ultrasound and to evaluate the relationship between tendon integrity and functional outcomes. We hypothesized that subjects with a healed subscapularis after RSA would have higher Constant scores and better internal rotation (IR) than those without a healed subscapularis.

METHODS

This was a retrospective review of all patients who underwent primary RSA with subscapularis tenotomy repair performed by a single surgeon with a minimum 2-year follow-up period. The inclusion criteria were (1) primary RSA and (2) complete intraoperative repair of the subscapularis tenotomy if the tendon was amenable to repair. The total Constant score and active and passive range of motion were measured preoperatively and at every postoperative visit. IR was further subcategorized into 3 functional types (type I, buttock or sacrum; type II, lumbar region; and type III, T12 or higher). The integrity of the subscapularis on ultrasound at 2 years was reported using the Sugaya classification. The correlation between subscapularis integrity and functional outcomes including functional IR was evaluated.

RESULTS

A total of 86 patients (mean age, 73 ± 7.4 years; age range, 50-89 years) were evaluated. The mean postoperative Constant score for all patients significantly improved from 38 points to 72 points (P < .001) at last follow-up (mean, 3.3 years). There was significant improvement in all Constant score functional subscales and in terms of range of motion. The rate of sonographic healing of the subscapularis was 52.6%. There was no difference in Constant scores between "intact" and "failed" tendon repairs; however, intact tendons demonstrated significantly better IR with no difference in external rotation (P < .01).

CONCLUSION

The healing rate of the subscapularis following RSA was only 52.6%. IR function in patients with an intact subscapularis at 2 years after RSA was significantly better than in patients with failed or absent tendon repairs. Primary repair of reparable subscapularis tendons during RSA should be strongly considered.

Comparing patient-reported outcome measures and physical examination for internal rotation in patients undergoing reverse shoulder arthroplasty: does surgery alter patients' perception of function?

BACKGROUND

The purpose of this study was to evaluate how patients treated with reverse shoulder arthroplasty (RSA) achieve internal rotation (IR) using video assessment and to compare this to patient-reported outcome measures (PROMs).

METHODS

We reviewed 215 preoperative and 657 postoperative videos (3-78 months) for 215 patients who underwent primary RSA, performing IR using the modified vertebral level method. Their functional motion pattern was then grouped into 3 types: type I, could not reach behind their back; type II, able to reach to at least waist level, with assistance; and type III, able to reach to a minimum of waist level in an uninterrupted fashion. Patients completed functional questions (put on a coat, wash back, tuck in a shirt, and manage toileting) and a diagram of perceived IR. Patients' functional motion types were compared to PROM answers. Pre- and postoperative scores were also compared to assess the effect of surgery on patients' perception of IR function.

RESULTS

Patients undergoing RSA will achieve IR in 3 distinct motion patterns. Analysis of self-reported IR indicated statistically significant difference between the 3 functional types of IR (P < .001). Patient-perceived IR was not significantly different between the 3 studied IR functional types (P = .076) in the analysis of preoperative measures but was significantly different in the postoperative setting (P < .001).

CONCLUSION

Patients attempt IR in 3 distinct functional motion patterns. The improvement of IR after RSA is measured better by patient questionnaires than by physical examination.

Adjusting Implant Size and Position Can Improve Internal Rotation After Reverse Total Shoulder Arthroplasty in a Three-dimensional Computational Model

BACKGROUND

Efforts during reverse total shoulder arthroplasty (RSA) have typically focused on maximizing ROM in elevation and external rotation and avoiding scapular notching. Improving internal rotation (IR) is often overlooked, despite its importance for functional outcomes in terms of patient self-care and hygiene. Although determinants of IR are multifactorial, it is unable to surpass limits of bony impingement of the implant. Identifying implant configurations that can reduce bony impingement in a computer model will help surgeons during preoperative planning and also direct implant design and clinical research going forward.

QUESTIONS/PURPOSES

In a CT-modeling study, we asked: What reverse total shoulder arthroplasty implant position improves the range of impingement free internal rotation without compromising other motions (external rotation and extension)?

METHODS

CT images stored in a deidentified teaching database from 25 consecutive patients with Walch A1 glenoids underwent three-dimensional templating for RSA. Each template used the same implant and configuration, which consisted of an onlay humeral design and a 36-mm standard glenosphere. The resulting constructs were virtually taken through ROM until bony impingement was found. Variations were made in the RSA parameters of baseplate lateralization, glenosphere size, glenosphere overhang, humeral version, and humeral neck-shaft angle. Simulated ROM was repeated after each parameter was changed individually and then again after combining multiple changes into a single configuration. The impingement-free IR was calculated and compared between groups. We also evaluated the effect on other ROM including external rotation and extension to ensure that configurations with improvements in IR were not associated with losses in other areas.

RESULTS

Combining lateralization, inferiorization, varus neck-shaft angle, increased glenosphere size, and increased humeral anteversion resulted in a greater improvement in internal rotation than any single parameter change did (median baseline IR: 85° [interquartile range 73° to 90°]; combined changes: 119° [IQR 113° to 121°], median difference: 37° [IQR 32° to 43°]; p < 0.001).

CONCLUSION

Increased glenosphere overhang, varus neck-shaft angle, and humeral anteversion improved internal rotation in a computational model, while glenoid lateralization alone did not. Combining these techniques led to the greatest improvement in IR.

CLINICAL RELEVANCE

This computer model study showed that various implant changes including inferiorization, varus neck-shaft angle, increased glenosphere size, and increased humeral anteversion can be combined to increase impingement-free IR. Surgeons can employ these currently available implant configurations to improve IR when planning and performing RSA. These findings support the need for further clinical studies validating the effect of implant configuration on resultant IR.