[Open reconstruction of the rotator cuff]

Biological Augmentation With Subacromial Bursa in Arthroscopic Rotator Cuff Repair

Rotator cuff tears can be associated with significant shoulder dysfunction and pain. Despite improved surgical techniques and new materials for rotator cuff reconstruction, there is no significant reduction in the re-rupture rate. Innovative approaches for enhanced tendon healing are required. The potential of biologically optimized tendon integration has probably been insufficiently explored so far. The existing practice of debridement might eliminate repair tissue and a major source of cells and blood vessels necessary for tendon healing. Biological augmentation may be an option to improve the healing process. The subacromial bursa is a highly proliferative tissue with mesenchymal stem cells capable of differentiating into various cell lines and is easily accessible during rotator cuff repair. We describe the technique of bursal augmentation in arthroscopic double-row SutureBridge repair of a posterosuperior rotator cuff tear with the aim of improving tendon-to-bone healing.

Characterization of bursa subacromialis-derived mesenchymal stem cells

Introduction

The bursa subacromialis (BS) provides the gliding mechanism of the shoulder and regenerates itself after surgical removal. Therefore, we explored the presence of mesenchymal stem cells (MSCs) within the human adult BS tissue and characterized the BS cells compared to MSCs from bone marrow (BMSCs) on a molecular level.

Methods

BS cells were isolated by collagenase digest from BS tissues derived from patients with degenerative rotator cuff tears, and BMSCs were recovered by adherent culture from bone-marrow of patients with osteoarthritis of the hip. BS cells and BMSCs were compared upon their potential to proliferate and differentiate along chondrogenic, osteogenic and adipogenic lineages under specific culture conditions. Expression profiles of markers associated with mesenchymal phenotypes were comparatively evaluated by flow cytometry, immunohistochemistry, and whole genome array analyses.

Results

BS cells and BMSCs appeared mainly fibroblastic and revealed almost similar surface antigen expression profiles, which was CD44⁺, CD73⁺, CD90⁺, CD105⁺, CD106⁺, STRO-1⁺, CD14⁻, CD31⁻, CD34⁻, CD45⁻, CD144⁻. Array analyses revealed 1969 genes upregulated and 1184 genes downregulated in BS cells vs. BMSCs, indicating a high level of transcriptome similarity. After 3 weeks of differentiation culture, BS cells and BMSCs showed a similar strong chondrogenic, adipogenic and osteogenic potential, as shown by histological, immunohistochemical and RT-PCR analyses in contrast to the respective negative controls.

Conclusions

Our in vitro characterizations show that BS cells fulfill all characteristics of mesenchymal stem cells, and therefore merit further attention for the development of improved therapies for various shoulder pathologies.

[Open transosseous reconstruction of the rotator cuff: clinical outcome, influencing factors and complications]

BACKGROUND

Open transosseous rotator cuff reconstruction (RCR) still plays a prominent role in current treatment of rotator cuff tears. This study aimed to examine mid-term and long-term results of clinical outcome, determine influencing factors and analyze complications.

PATIENTS

This retrospective cohort study included 104 Patients following standardized open transosseous RCR. After a mean follow-up period of 38.3 months (range 12-71 months) 88 Patients (89 shoulders) were available for examination. The mean age of Patients at surgery was 57.1 years (range 29-83 years). Standardized clinical examination included sonography and assessment of the absolute, relative and intra-individual constant scores (CS(abs), CS(rel), CS(intra)), Oxford shoulder score (OSS), American shoulder and elbow surgeons' score (ASESS) and single assessment numeric evaluation score (SANES). The level of significance for analysis of variance (ANOVA) was set at p < 0.05 (95% confidence interval).

RESULTS

Mean values and standard deviations (σ) were: CS(abs) = 71 points (σ: 20.3), CS(rel) = 76 points (σ: 20.7), CS(intra) = 86 % (σ: 19.5), OSS(mod) = 77 points (σ: 20.6), ASESS = 73 points (σ: 23.3) and SANES = 72 % (σ: 22.0). Clinical results were superior when the complaints were initiated by trauma (p < 0.05). Patients with massive tears showed inferior results relative to all outcome measures (p < 0.05). Concomitant pathologies even without surgical relevance were associated with inferior outcome (p < 0.05). The factors surgeon, suture material and acromioplasty did not exert a significant influence. Revision surgery was required in 12 out of 89 (13.5 %) cases and re-ruptures occurred in 19.1%.

CONCLUSIONS

Objective and subjective clinical results following open transosseous RCR were comparable to those of previously described open and arthroscopic techniques. Results were superior when the complaints were initiated by trauma. Massive tears and concomitant pathologies even without surgical relevance were associated with inferior clinical outcome. Open or arthroscopic acromioplasty did not add further benefits. A standardized operative procedure led to reproducible results irrespective of the factor surgeon.

Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair

BACKGROUND

The surgical treatment of massive rotator cuff tears (RCT) is still controversial and can be based on a variety of different surgical repair methods. This study investigated the effectiveness of arthroscopic debridement or arthroscopic partial repair in patients with massive RCT.

MATERIALS AND METHODS

This prospective, randomized study involved forty-two patients with massive RCT (fatty infiltration stage 3 or 4) treated with either arthroscopic partial repair or arthroscopic debridement were selected to detect possible differences in functional outcome. Both groups were matched according to age and gender. Patients were examined before, and 16 +/- 3 and 24 +/- 2 months after surgery. The status of the rotator cuff repair was determined using ultrasonographic evaluation.

RESULTS

Regardless of the treatment group, postoperative results demonstrated highly significant improvements compared with preoperative values in most parameters. The overall Constant score in the partial repair group was superior to the outcome in the debridement group (P < 0.01, F = 8.561), according to better results in abduction (P < 0.01, F = 13.249), activity (P < 0.01, F = 21.391) and motion (P < 0.01, F = 4.967). All treatment groups had similar pain relief (P = 0.172, F = 1.802) and satisfaction, reflected in equal values of disabilities of the arm, shoulder and hand (DASH) score (P = 0.948, F = 0.004). Ultrasonography revealed structural failure of the partial rotator cuff repair in 52% at final follow-up.

CONCLUSIONS

During the follow-up period all patients in our series had good or satisfactory outcome after rotator cuff surgery. Regardless of high rates of structural failure of the partial rotator cuff repair, the results of arthroscopic partial rotator cuff repair demonstrated slightly better functional outcome than debridement.