BACKGROUND

Postoperative shoulder stiffness (POSS) is a prevalent adverse event after arthroscopic rotator cuff repair (ARCR) that is associated with major limitations in everyday activities and prolonged rehabilitation.

PURPOSE/HYPOTHESIS

The purpose was to develop a predictive model for determining the risk of POSS within 6 months after primary ARCR. We hypothesized that sufficient discrimination ability of such a model could be achieved using a local institutional database.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Consecutive primary ARCRs documented in a local clinical registry between 2013 and 2017 were included, and patients who experienced POSS before the final clinical 6-month follow-up were identified. A total of 29 prognostic factor candidates were considered, including patient-related factors (n = 7), disease-related factors (n = 9), rotator cuff integrity factors (n = 6), and operative details (n = 7). We used imputed data for the primary analysis, and a sensitivity analysis was conducted using complete case data. Logistic regression was applied to develop a model based on clinical relevance and statistical criteria. To avoid overfitting in the multivariable model, highly correlated predictors were not included together in any model. A final prognostic model with a maximum of 8 prognostic factors was considered. The model's predictive accuracy was assessed by the area under the receiver operating characteristic curve (AUC). Internal validation was performed using bootstrapping.

RESULTS

Of 1330 ARCR cases (N = 1330 patients), 112 (8.4%) patients had POSS. Our final model had a moderate predictive ability with an AUC of 0.67. The predicted risks of POSS ranged from 2.3% to 38.9% and were significantly higher in women; patients with partial tears, low baseline passive shoulder abduction, and lack of tendon degeneration; and when no acromioplasty was performed.

CONCLUSION

A prognostic model for POSS was developed for patients with ARCR, offering a personalized risk evaluation to support the future decision process for surgery and rehabilitation.

AIM

The purpose of the trial was to evaluate the efficacy of suprascapular nerve block (SSNB) to relieve the shoulder pain, ameliorate recovery after physiotherapy and reduce disability due to a rotator cuff tendinitis (RCT). A prospective, randomized, comparison cross over investigation was performed in the setting of a large inpatient rehabilitation unit with more than 200 admissions annually.

METHODS

A total of 40 potential study subjects, who complained of shoulder pain from a RCT, were enrolled and randomly assigned to standard rehabilitation treatment plus SSNB (Group A) or to standard rehabilitation treatment alone (Group B). The UCLA shoulder rating scale was used to assess the shoulder mobility on admission and discharge, and to calculate the percentage of potential improvement achieved during rehabilitation (effectiveness). A pain visual analogic scale was used to serially assess pain. At the end of the trial, a self-report questionnaire evaluated whether patients could sleep and achieve activity of day life carry out everyday activities better than they could before treatment.

RESULTS

Forty patients suffering from RCT entered the study. Those receiving nerve block from the beginning of the treatment in addition to standard rehabilitation therapy reported significantly less pain during physiotherapy and better final outcomes. During treatment with SSNBs, patients reported a more significant reduction in the intensity of pain and a better reduction of pain during sleep and rehabilitation exercises in comparison to with the standard therapy alone. A statistically significant inverse correlation was found between shoulder pain and mobility.

CONCLUSIONS

The results indicate that combining nerve block with standard rehabilitative therapy may improve the final outcome of painful RCT. It decreased the severity and frequency of the perceived pain, improved the compliance with physiotherapy, restored more normal sleep patterns, and increased compliance with the rehabilitation program. This result proves to be an effective, safe and inexpensive therapeutic option for patients suffering from painful disabling shoulder tendinitis.

BACKGROUND

Driving is one of the most common everyday tasks and the rotator cuff muscles are the primary shoulder stabilisers. Muscle forces during driving are not currently known, yet knowledge of these would influence important clinical advice such as return to activities after surgery. The aim of this study is to quantify shoulder and rotator cuff muscle forces during driving in different postures.

METHODS

A musculoskeletal modelling approach is taken, using a modified driving simulator in combination with an upper limb musculoskeletal model (UK National Shoulder Model). Motion data and external force vectors were model inputs and upper limb muscle and joint forces were the outputs.

FINDINGS

Comparisons of the predicted glenohumeral joint forces were compared to in vivo literature values, with good agreement demonstrated (61 SD 8% body weight mean peak compared to 60 SD 1% body weight mean peak). High muscle activation was predicted in the rotator cuff muscles; particularly supraspinatus (mean 55% of the maximum and up to 164 SD 27 N). This level of loading is up to 72% of mean failure strength for supraspinatus repairs, and could therefore be dangerous for some cases. Statistically significant and large differences are shown to exist in the joint and muscle forces for different driving positions as well as steering with one or both hands (up to 46% body weight glenohumeral joint force).

INTERPRETATION

These conclusions should be a key consideration in rehabilitating the shoulder after surgery, preventing specific upper limb injuries and predicting return to driving recommendations.

Copyright © 2015. Published by Elsevier Ltd.

Adaptive muscle activation strategies following a massive rotator cuff tear (MRCT) are inadequately understood, and the relationship among muscles during everyday activities has not been considered. Thirteen healthy subjects comprised the control group, and 11 subjects with a MRCT the patient group. Upper limb function was assessed using the Functional Impairment test-hand, neck, shoulder, and arm (FIT-HaNSA). Electromyography (EMG) was recorded from 13 shoulder muscles, comprising five muscle groups, during a shelf-lifting task. Mean FIT-HaNSA scores were significantly lower in MRCT patients (p≤0.001), reflecting a severe functional deficit. In MRCT patients, EMG signal amplitude was significantly higher for the biceps brachii-brachioradialis (p < 0.001), upper trapezius-serratus anterior (p= 0.025), muscle groups and for the latissimus dorsi (p = 0.010), and teres major (p=0.007) muscles. No significant differences in the correlation among muscle groups were identified, pointing to an unchanged neuromuscular strategy following a tear. In MRCT patients, a reorganization of muscle activation strategy along the upper limb kinetic chain is aimed at reducing demand on the glenohumeral joint. Increased activation of the latissimus dorsi and teres major muscles is an attempt to compensate for the deficient rotator cuff. Re-education towards an alternate neuromuscular control strategy appears necessary to restore function.

Copyright © 2012 Orthopaedic Research Society.