Arthroscopic Rotator Cuff Repair with Double-Row Fixation

Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis

BACKGROUND

Important differences in clinical outcomes likely exist between patients with healed and nonhealed rotator cuff repairs. The survival probability of rotator cuff repairs has not been published in a time-dependent manner up to now.

HYPOTHESES

Recurrent tears occur more frequently in the early postoperative period. Early failures of the repair are a prognostic factor for the long-term outcome.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A series of 107 consecutive patients undergoing arthroscopically assisted mini-open repair of the rotator cuff between 1998 and 2002 were evaluated in a prospective study. Of these, 95 patients finished the study after a maximum follow-up of 11 years. The evaluation included 1 postoperative magnetic resonance imaging scan as well as multiple ultrasonographies and determinations of the American Shoulder and Elbow Surgeons (ASES) and Constant scores at 3 months, 6 months, 1 year, and then yearly with a median follow-up of 96 months.

RESULTS

The overall failure rate was 33% (35 of 107). The survivorship analysis revealed that 74% of all failures occurred atraumatically in the first 3 months and 11% occurred between the third and the sixth month after the repair. The remaining reruptures (14%) happened 2 to 5 years postoperatively and were related to sports activities or direct trauma. The overall clinical results did not deteriorate over time. The parameters healed tendon, rerupture of less than 2 cm(2), and rerupture of more than 2 cm(2) at 6 months were predictors of the gender- and age-adjusted (normalized) Constant score at 84 months (P < .0001).

CONCLUSION

The majority of recurrent tears occurred in the first 3 months after surgical repair. The parameters "recurrent tear" as well as "healed tendon" evaluated at 6 months postoperatively appear to be predictors for the clinical outcomes at 7 years. Efforts to improve healing during the initial 3 months have long-term implications for maintenance of cuff integrity and clinical outcomes.

Bone marrow-derived mesenchymal stem cells transduced with scleraxis improve rotator cuff healing in a rat model

BACKGROUND

Rotator cuffs heal through a scar tissue interface after repair that makes them prone to failure. Scleraxis (Scx) is a basic helix-loop-helix transcription factor that is thought to direct tendon development during embryogenesis. The purpose of this study was to determine if the application of mesenchymal stem cells (MSCs) transduced with adenoviral-mediated scleraxis (Ad-Scx) could improve regeneration of the tendon-bone insertion site in a rat rotator cuff repair model.

HYPOTHESIS

Bone marrow-derived cells transduced with Scx would improve the structure of the healing tendon-bone interface and result in increased tendon attachment strength.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixty Lewis rats underwent unilateral detachment and repair of the supraspinatus tendon. Thirty animals received MSCs in a fibrin glue carrier, and 30 received Ad-Scx-transduced MSCs. Animals were sacrificed at 2 weeks and 4 weeks and evaluated for the presence of fibrocartilage and collagen fiber organization at the insertion. Biomechanical testing was performed to determine the structural and material properties of the repaired tissue. Statistical analysis was performed with a Wilcoxon rank sum test with significance set at P = .05.

RESULTS

There were no differences between the Scx and MSC groups in terms of histologic appearance at 2 weeks. However, the Scx group had higher ultimate stress-to-failure (2.6 ± 0.9 vs 1.7 ± 0.3 MPa; P = .03) and stiffness (8.4 ± 2.9 vs 5.0 ± 1.9 N/mm; P = .01) compared with the MSC group. At 4 weeks, the Scx group had more fibrocartilage (728.7 ± 50.4 vs 342.6 ± 217.0 mm(2); P = .04), higher ultimate load to failure (26.7 ± 4.6 vs 20.8 ± 4.4 N; P = .01), higher ultimate stress to failure (4.7 ± 1.3 vs 3.5 ± 1.0 MPa; P < .04), and higher stiffness values (15.3 ± 3.4 vs 9.3 ± 2.2 N/mm; P < .001) as compared with the MSC group.

CONCLUSION

Mesenchymal stem cells genetically modified with Scx can augment rotator cuff healing at early time points.

CLINICAL RELEVANCE

Biologic augmentation of acutely injured rotator cuffs with Scx-transduced MSCs may improve rotator cuff tendon healing and reduce the incidence of re-tears. However, further studies are needed to determine if this remains safe and effective in larger models.

Effect of shoulder abduction angle on biomechanical properties of the repaired rotator cuff tendons with 3 types of double-row technique

BACKGROUND

After rotator cuff repair, the shoulder is immobilized in various abduction positions. However, there is no consensus on the proper abduction angle.

PURPOSE

To assess the effect of shoulder abduction angle on the biomechanical properties of the repaired rotator cuff tendons among 3 types of double-row techniques.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty-two fresh-frozen porcine shoulders were used. A simulated rotator cuff tear was repaired by 1 of 3 double-row techniques: conventional double-row repair, transosseous-equivalent repair, and a combination of conventional double-row and bridging sutures (compression double-row repair). Each specimen underwent cyclic testing followed by tensile testing to failure at a simulated shoulder abduction angle of 0° or 40° on a material testing machine. Gap formation and failure loads were measured.

RESULTS

Gap formation in conventional double-row repair at 0° (1.2 ± 0.5 mm) was significantly greater than that at 40° (0.5 ± 0.3mm, P = .01). The yield and ultimate failure loads for conventional double-row repair at 40° were significantly larger than those at 0° (P < .01), whereas those for transosseous-equivalent repair (P < .01) and compression double-row repair (P < .0001) at 0° were significantly larger than those at 40°. The failure load for compression double-row repair was the greatest among the 3 double-row techniques at both 0° and 40° of abduction.

CONCLUSION

Bridging sutures have a greater effect on the biomechanical properties of the repaired rotator cuff tendon at a low abduction angle, and the conventional double-row technique has a greater effect at a high abduction angle.

CLINICAL RELEVANCE

Proper abduction position after rotator cuff repair differs between conventional double-row repair and transosseous-equivalent repair. The authors recommend the use of the combined technique of conventional double-row and bridging sutures to obtain better biomechanical properties at both low and high abduction angles.

Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome: surgical technique

BACKGROUND

Literature regarding the outcomes of revision rotator cuff repair is limited. The purposes of the present study were to report the tendon repair integrity and clinical outcomes for a cohort of patients following revision arthroscopic rotator cuff repair and to examine factors related to tendon healing and the influence of healing on clinical outcomes.

METHODS

Twenty-one of twenty-nine consecutive revision arthroscopic rotator cuff repairs with a minimum of two years of postoperative follow-up were retrospectively reviewed. Outcomes were evaluated on the basis of a visual analog pain scale, the range of motion of the shoulder, the Simple Shoulder Test, the American Shoulder and Elbow Surgeons score, and the Constant score. Ultrasonography was used to examine repair integrity at a minimum of one year following surgery. Ten shoulders underwent arthroscopic repair of a recurrent single-tendon posterior rotator cuff tear, whereas eleven shoulders had repair of both the supraspinatus and infraspinatus.

RESULTS

The mean age of the twenty-one subjects was 55.6 years; thirteen subjects were male and eight were female. Complete preoperative and postoperative clinical data were available for nineteen subjects after an average duration of follow-up of thirty-three months. Significant improvements were seen in terms of postoperative pain (p < 0.05), the Simple Shoulder Test score (p < 0.05), the American Shoulder and Elbow Surgeons function (p < 0.05) and total scores (p < 0.05), active forward elevation (p < 0.05), and active external rotation (p < 0.05). Postoperative ultrasound data were available for all twenty-one shoulders after a mean duration of follow-up of twenty-five months. Ten (48%) of the twenty-one shoulders had an intact repair. Seven (70%) of the ten single-tendon repairs were intact, compared with three (27%) of the eleven supraspinatus/infraspinatus repairs (p = 0.05). Patient age (p < 0.05) and the number of torn tendons (p = 0.05) had significant effects on postoperative tendon repair integrity. Shoulders with an intact repair had better postoperative Constant scores (p < 0.05) and scapular plane elevation strength (p < 0.05) in comparison with those with a recurrent tear.

CONCLUSIONS

Revision arthroscopic rotator cuff repair results in reliable pain relief and improvement in shoulder function in selected cases. Approximately half of the revision repairs can be expected to be intact at a minimum of one year following surgery. Patient age and the number of torn tendons are related to postoperative tendon integrity. The postoperative integrity of the rotator cuff can have a significant influence on shoulder abduction strength and the Constant score.

Fourier transform infrared spectroscopic analysis of normal and torn rotator-cuff tendons

We have used Fourier transform infrared spectroscopy (FTIR) to characterise the chemical and structural composition of the tendons of the rotator cuff and to identify structural differences among anatomically distinct tears. Such information may help to identify biomarkers of tears and to provide insight into the rates of healing of different sizes of tear. The infrared spectra of 81 partial, small, medium, large and massive tears were measured using FTIR and compared with 11 uninjured control tendons. All the spectra were classified using standard techniques of multivariate analysis.

FTIR readily differentiates between normal and torn tendons, and different sizes of tear. We identified the key discriminating molecules and spectra altered in torn tendons to be carbohydrates/phospholipids (1030 cm−1 to 1200 cm−1), collagen (1300 cm−1 to 1700 cm−1 and 3000 cm−1 to 3350 cm−1) and lipids (2800 cm−1 to 3000 cm−1).

Our study has shown that FTIR spectroscopy can identify tears of the rotator cuff of varying size based upon distinguishable chemical and structural features. The onset of a tear is mainly associated with altered structural arrangements of collagen, with changes in lipids and carbohydrates. The approach described is rapid and has the potential to be used peri-operatively to determine the quality of the tendon and the extent of the disease, thus guiding surgical repair.

Clinical and structural evaluation of arthroscopic double-row suture-bridge rotator cuff repair: early results of a novel technique

PURPOSE

Assessment of repair integrity and clinical outcome after arthroscopic repair of rotator cuff tears in double-row suture-bridge technique with the use of a new knotless suture-anchor system.

METHODS

The first treated 25 patients with arthroscopic rotator cuff repair in the suture-bridge technique using a novel knotless anchor and chain-link suture system were evaluated. Patients with isolated full-thickness supraspinatus tears were selected. They were followed clinically with functional scores (Constant score, ASES index), visual analog scale (VAS), and instrumentally with Isobex digital strength analyzer preoperatively, at 6 and 14 months postoperatively. The repair integrity was evaluated with MRI at an average of 14 months postoperatively.

RESULTS

Significant improvement of pain, strength, range of motion, and functional scores occurred (P < 0.05). There was a re-tear rate of 20%. The subjective parameters (VAS and ASES Index) showed non-significant (n.s.) differences between the re-tear and intact repair groups, whereas the objective parameters (Constant score, muscle power and active ROM) showed significant differences between both groups (P < 0.05).

CONCLUSION

The functional outcome has improved significantly with this new knotless anchor-chain system and was more superior in shoulders with intact repair, whereas the resulted repair integrity was not better than other types of double-row repair techniques mentioned in the recent literature. However, this early report of the novel technique may show limited power for comparison due to the relatively small sample size.

Factors affecting healing rates after arthroscopic double-row rotator cuff repair

BACKGROUND

Double-row arthroscopic rotator cuff repairs were developed to improve initial biomechanical strength of repairs to improve healing rates. Despite biomechanical improvements, failure of healing remains a clinical problem.

PURPOSE

To evaluate the anatomical results after double-row arthroscopic rotator cuff repair with ultrasound to determine postoperative repair integrity and the effect of various factors on tendon healing.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-eight patients (49 shoulders) who had a complete arthroscopic rotator cuff repair (double-row technique) were evaluated with ultrasound at a minimum of 6 months after surgery. Outcome was evaluated at a minimum of 1-year follow-up with standardized history and physical examination, visual analog scale for pain, active forward elevation, and preoperative and postoperative shoulder scores according to the system of the American Shoulder and Elbow Surgeons and the Simple Shoulder Test. Quantitative strength was measured postoperatively.

RESULTS

Ultrasound and physical examinations were performed at a minimum of 6 months after surgery (mean, 16 months; range, 6 to 36 months) and outcome questionnaire evaluations at a minimum of 12 months after surgery (mean, 29 months; range, 12 to 55 months). Of 49 repairs, 25 (51%) were healed. Healing rates were 67% in single-tendon tears (16 of 24 shoulders) and 36% in multitendon tears (9 of 25 shoulders). Older age and longer duration of follow-up were correlated with poorer tendon healing (P < .03). Visual analog scale for pain, active forward elevation, American Shoulder and Elbow Surgeons scores, and Simple Shoulder Test scores all had significant improvement from baseline after repair (P < .0001).

CONCLUSION

Increased age and longer duration of follow-up were associated with lower healing rates after double-row rotator cuff repair. The biological limitation at the repair site, as reflected by the effects of age on healing, appears to be the most important factor influencing tendon healing, even after maximizing repair biomechanical strength with a double-row construct.

Single versus double-row repair of the rotator cuff: does double-row repair with improved anatomical and biomechanical characteristics lead to better clinical outcome?

PURPOSE

Several techniques for arthroscopic repair of rotator cuff defects have been introduced over the past years. Besides established techniques such as single-row repairs, new techniques such as double-row reconstructions have gained increasing interest. The present article therefore provides an overview of the currently available literature on both repair techniques with respect to several anatomical, biomechanical, clinical and structural endpoints.

METHODS

Systematic literature review of biomechanical, clinical and radiographic studies investigating or comparing single- and double-row techniques. These results were evaluated and compared to provide an overview on benefits and drawbacks of the respective repair type.

RESULTS

Reconstructions of the tendon-to-bone unit for full-thickness tears in either single- or double-row technique differ with respect to several endpoints. Double-row repair techniques provide more anatomical reconstructions of the footprint and superior initial biomechanical characteristics when compared to single-row repair. With regard to clinical results, no significant differences were found while radiological data suggest a better structural tendon integrity following double-row fixation.

CONCLUSION

Presently published clinical studies cannot emphasize a clearly superior technique at this time. Available biomechanical studies are in favour of double-row repair. Radiographic studies suggest a beneficial effect of double-row reconstruction on structural integrity of the reattached tendon or reduced recurrent defect rates, respectively.

Stem cells genetically modified with the developmental gene MT1-MMP improve regeneration of the supraspinatus tendon-to-bone insertion site

BACKGROUND

Rotator cuffs heal through a scar tissue interface after repair, which makes them prone to failure. Membrane type 1 matrix metalloproteinase (MT1-MMP) is upregulated during embryogenesis in areas that develop into tendon-bone insertion sites.

HYPOTHESIS

Bone marrow-derived stem cells in the presence of the developmental signal from MT1-MMP will drive the healing process toward regeneration and away from scar formation.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixty Lewis rats underwent unilateral detachment and repair of the supraspinatus tendon. Thirty animals received mesenchymal stem cells (MSCs) in a fibrin glue carrier, and 30 received adenoviral MT1-MMP (Ad-MT1-MMP)-transduced MSCs. Animals were sacrificed at 2 weeks and 4 weeks and evaluated for the presence of fibrocartilage and collagen fiber organization at the insertion. Biomechanical testing was performed to determine the structural and material properties of the repaired tissue. Statistical analysis was performed with a Wilcoxon rank-sum test with significance set at P = .05.

RESULTS

There were no differences between the Ad-MT1-MMP and MSC groups in any outcome variable at 2 weeks. At 4 weeks, the Ad-MT1-MMP group had more fibrocartilage (P = .05), higher ultimate load to failure (P = .01), higher ultimate stress to failure (P = .005), and higher stiffness values (P = .02) as compared with the MSC group.

CONCLUSION

Mesenchymal stem cells genetically modified to overexpress the developmental gene MT1-MMP can augment rotator cuff healing at 4 weeks by the presence of more fibrocartilage at the insertion and improved biomechanical strength.

CLINICAL RELEVANCE

Biologic augmentation of repaired rotator cuffs with MT1-MMP-transduced MSCs may reduce the incidence of retears. However, further studies are needed to determine if this remains safe and effective in larger models.

Arthroscopic supraspinatus tendon repair with suture-bridging technique: functional outcome and magnetic resonance imaging

BACKGROUND

The suture-bridging technique is a new arthroscopic technique to repair rotator cuff tears. Biomechanical advantages compared with double-row fixations have been described.

HYPOTHESIS

The authors hypothesized that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fifty-one consecutive patients, with a median age of 62 years (range, 37-76 years), who had undergone an arthroscopic suture-bridging repair of an isolated supraspinatus tendon tear were evaluated in this prospective study 4, 12, and a median of 24 months postoperatively. Subjective and functional outcome was assessed using the simple shoulder test and Constant score. With magnetic resonance imaging 12 months postoperatively, the tendon integrity and potential predictors of failures were evaluated.

RESULTS

The simple shoulder test scores improved significantly from 9 points (range, 1-12 points) at 4 months, to 12 points (range, 1-12 points) at 12 months, and 12 points (range, 5-12 points) at 24 months postoperatively. The Constant score increased significantly from preoperative 64% (range, 37%-92%) to 82% (range, 36%-100%) at 4 months, 96% (range, 49%-100%) at 12 months, and 96% (range, 64%-100%) at 24 months postoperatively. Magnetic resonance imaging 12 months after surgery showed retears in 28.9%. Two different types of retears could be observed: insufficiently healed and medially retorn supraspinatus tendons. The Constant score did not differ significantly between the groups with retears and intact repairs. A patient age of more than 60 years was found to influence tendon healing significantly.

CONCLUSION

The hypothesis, that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation, could not be confirmed. The functional outcome after the new suture-bridging technique was good and comparable with the reported results after double-row repair from the literature. A structural failure of tendon repair was not identical to clinical failure.

Which method of rotator cuff repair leads to the highest rate of structural healing? A systematic review

BACKGROUND

The purpose of rotator cuff repair is to diminish pain and restore function, and this most predictably occurs when the tendon is demonstrated to heal. Recent improvements in repair methods have led to improved biomechanical performance, but this has not yet been demonstrated to result in higher healing rates. The purpose of our study was to determine whether different repair methods resulted in different rates of recurrent tearing after surgery.

HYPOTHESES

We hypothesized that (1) the rotator cuff repair method will not affect retear rate, and (2) the surgical approach will not affect the retear rate for a given repair method.

STUDY DESIGN

Systematic review of the literature.

METHODS

The literature was systematically searched to find articles reporting imaging study assessment of structural healing rates after rotator cuff repair, with data stratified according to tear size. Retear rates were compared for transosseous (TO), single-row suture anchor (SA), double-row suture anchor (DA), and suture bridge (SB) repair methods, as well as for open (O), miniopen (MO), and arthroscopic (A) approaches.

RESULTS

Retear rates were available for 1252 repairs collected from 23 studies. Retear rates were significantly lower for double-row repairs when compared with TO or SA for all tears greater than 1 cm and ranged from 7% for tears less than 1 cm to 41% for tears greater than 5 cm, in comparison with retear rates for single-row techniques (TO and SA) of 17% to 69% for tears less than 1 cm and greater than 5 cm, respectively. There was no significant difference in retear rates between TO and SA repair methods or between arthroscopic and nonarthroscopic approaches for any tear size.

CONCLUSION

Double-row repair methods lead to significantly lower retear rates when compared with single-row methods for tears greater than 1 cm. Surgical approach has no significant effect on retear rate.

Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome

BACKGROUND

Literature regarding the outcomes of revision rotator cuff repair is limited. The purposes of the present study were to report the tendon repair integrity and clinical outcomes for a cohort of patients following revision arthroscopic rotator cuff repair and to examine factors related to tendon healing and the influence of healing on clinical outcomes.

METHODS

Twenty-one of twenty-nine consecutive revision arthroscopic rotator cuff repairs with a minimum of two years of postoperative follow-up were retrospectively reviewed. Outcomes were evaluated on the basis of a visual analog pain scale, the range of motion of the shoulder, the Simple Shoulder Test, the American Shoulder and Elbow Surgeons score, and the Constant score. Ultrasonography was used to examine repair integrity at a minimum of one year following surgery. Ten shoulders underwent arthroscopic repair of a recurrent single-tendon posterior rotator cuff tear, whereas eleven shoulders had repair of both the supraspinatus and infraspinatus.

RESULTS

The mean age of the twenty-one subjects was 55.6 years; thirteen subjects were male and eight were female. Complete preoperative and postoperative clinical data were available for nineteen subjects after an average duration of follow-up of thirty-three months. Significant improvements were seen in terms of postoperative pain (p < 0.05), the Simple Shoulder Test score (p < 0.05), the American Shoulder and Elbow Surgeons function (p < 0.05) and total scores (p < 0.05), active forward elevation (p < 0.05), and active external rotation (p < 0.05). Postoperative ultrasound data were available for all twenty-one shoulders after a mean duration of follow-up of twenty-five months. Ten (48%) of the twenty-one shoulders had an intact repair. Seven (70%) of the ten single-tendon repairs were intact, compared with three (27%) of the eleven supraspinatus/infraspinatus repairs (p = 0.05). Patient age (p < 0.05) and the number of torn tendons (p = 0.05) had significant effects on postoperative tendon repair integrity. Shoulders with an intact repair had better postoperative Constant scores (p < 0.05) and scapular plane elevation strength (p < 0.05) in comparison with those with a recurrent tear.

CONCLUSIONS

Revision arthroscopic rotator cuff repair results in reliable pain relief and improvement in shoulder function in selected cases. Approximately half of the revision repairs can be expected to be intact at a minimum of one year following surgery. Patient age and the number of torn tendons are related to postoperative tendon integrity. The postoperative integrity of the rotator cuff can have a significant influence on shoulder abduction strength and the Constant score.

Biomechanical and biologic augmentation for the treatment of massive rotator cuff tears

Recent studies have reported that massive rotator cuff tears do not heal as predictably as, and may have diminished clinical outcomes compared with, smaller rotator cuff tears. An improved understanding of the biologic degeneration and the biomechanical alterations of massive rotator cuff tears should provide better strategies to optimize outcomes. The approach to patients with massive rotator cuff tears requires careful assessment of the patient and the extent of rotator cuff degeneration to determine the appropriate treatment. For a rotator cuff tear that is repairable, the goal is to produce a tension-free, anatomical repair that restores the footprint using soft tissue releases and various suturing techniques, including double-row, transosseous-equivalent suture bridges or the rip-stop stitch. For irreparable cuff tears, the surgeon may elect to proceed with 1 of 2 approaches: (1) palliative surgical treatment-that is, rotator cuff debridement, synovectomy, biceps tenotomy, tuberoplasty and/or nonanatomical repair with partial repair; or (2) salvage treatment with various tendon transfers. Even though the biomechanical constructs for rotator cuff repairs have been improved, the integrity of the repair still depends on biologic healing at the tendon-to-bone junction. There has been much interest in the development of a scaffold to bridge massive rotator cuff tears and adjuvant biologic modalities including growth factors and tenocyte-seeded scaffolds to augment tendon-to-bone healing. The treatment of rotator cuff disease has improved considerably, but massive rotator cuff tears continue to pose a challenging problem for orthopaedic surgeons.

Comparison between surgery and physiotherapy in the treatment of small and medium-sized tears of the rotator cuff: A randomised controlled study of 103 patients with one-year follow-up

In order to compare the outcome from surgical repair and physiotherapy, 103 patients with symptomatic small and medium-sized tears of the rotator cuff were randomly allocated to one of the two approaches. The primary outcome measure was the Constant score, and secondary outcome measures included the self-report section of the American Shoulder and Elbow Surgeons score, the Short Form 36 Health Survey and subscores for shoulder movement, pain, strength and patient satisfaction. Scores were taken at baseline and after six and 12 months by a blinded assessor. Nine patients (18%) with insufficient benefit from physiotherapy after at least 15 treatment sessions underwent secondary surgical treatment. Analysis of between-group differences showed better results for the surgery group on the Constant scale (difference 13.0 points, p - 0.002), on the American Shoulder and Elbow surgeons scale (difference 16.1 points, p < 0.0005), for pain-free abduction (difference 28.8 degrees , p = 0.003) and for reduction in pain (difference on a visual analogue scale -1.7 cm, p < 0.0005).

Shoulder activity level in the preoperative assessment of patients with rotator cuff tears

The purpose of this study was to investigate shoulder activity level in preoperative assessment of shoulder function and health-related quality of life (QoL) for patients with rotator cuff tears. One hundred and six patients with rotator cuff tears were prospectively evaluated using the following outcome instruments: the Shoulder Activity scale, the Constant scale, the Simple Shoulder Test, and the Short Form-36v2 (SF-36v2). Clinical and structural data, including patients' demographics, comorbidities, duration of symptoms, shoulder contracture, and tear size, were collected and analyzed. We determined that the shoulder activity level was associated with gender, medical comorbidities, and age. Females had lower activity level, worse scores for health-related QoL, and longer duration of symptoms than males. Patients who had severe comorbidities had lower shoulder activity scores and worse SF-36v2 scores compared to patients who did not have such comorbidities. The patient age correlated with the shoulder activity level, but did not have significant correlation with the duration of symptoms and shoulder function. The shoulder activity level was related to patient gender, general health status and age; therefore, further investigation is warranted to determine if the activity level can be used as a prognostic variable relating to outcome in the treatment of rotator cuff tears.

Arthroscopic rotator cuff repair: prospective evaluation with sequential ultrasonography

BACKGROUND

Recent studies have demonstrated predictable healing after arthroscopic rotator cuff repair at a single time point, but few studies have evaluated tendon healing over time.

HYPOTHESIS

Rotator cuff tears that are intact on ultrasound at 1 time point will remain intact, and clinical results will improve regardless of healing status.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The Arthroscopic Rotator Cuff Registry was established to determine the effectiveness of arthroscopic rotator cuff repair with clinical outcomes using the American Shoulder and Elbow Surgeons score and ultrasound at 1 and 2 years, postoperatively. Patients were assigned to 1 of 3 groups based on ultrasound appearance: group 1, rotator cuff tendon intact at 1 and 2 years (n = 63); group 2, rotator cuff tendon defect at 1 and 2 years (n = 23); group 3, rotator cuff tendon defect at 1 year but no defect at 2 years (n = 7).

RESULTS

The ultrasound appearance was consistent at 1 and 2 years for 86 of the 93 patients (92.5%). The patients in group 1 had a significantly lower mean age (57.8 +/- 9.8 years) than the patients of group 2 (63.6 +/- 8.6 years; P = .04). Group 2 had a significantly greater rotator cuff tear size (4.36 +/- 1.6 cm) than group 1 (2.84 +/- 1.1 cm; P = .00025). Each group had a significant improvement in American Shoulder and Elbow Surgeons scores from baseline to 2-year follow-up. CONCLUSION All intact rotator cuff tendons at 1 year remained intact at 2 years. A small group of patients with postoperative imaging did not appear healed by ultrasound at 1 year but did so at 2 years. Patients demonstrated improvement in American Shoulder and Elbow Surgeons shoulder scores, range of motion, and strength, regardless of tendon healing status on ultrasound.

Evaluation of glenoid capsulolabral complex insertional anatomy and restoration with single- and double-row capsulolabral repairs

BACKGROUND

The purpose of this study was to evaluate the normal glenoid insertional anatomy of the anterior-inferior capsulolabral complex and to compare the ability of a single-row repair and a double-row suture bridge repair to restore the insertional anatomy.

METHODS

Eight fresh frozen cadaver shoulders were dissected and the native glenoid insertion of the anterior-inferior capsulolabral complex was digitized. Bankart lesions were created, the shoulders were randomized to receive either the standard single-row suture anchor repair or a double-row suture bridge repair, and the insertion repair sites were then digitized.

RESULTS

The single-row repair recreated 42.3% of the native footprint surface area while the double-row repair recreated 85.9%. The double-row repair was significantly larger and recreated significantly more of the native footprint compared with single-row repair (P < .01).

CONCLUSION

Double-row repair of the capsulolabral complex reestablishes the native insertional footprint on the anterior inferior glenoid better than a single-row repair.

LEVEL OF EVIDENCE

Basic science study.

Biomechanical evaluation of knotless anatomical double-layer double-row rotator cuff repair: a comparative ex vivo study

BACKGROUND

The layered configuration of the rotator cuff tendon is not taken into account in classic rotator cuff tendon repair techniques.

HYPOTHESIS

The mechanical properties of (1) the classic double-row technique, (2) a double-layer double-row (DLDR) technique in simple suture configuration, and (3) a DLDR technique in mattress suture configuration are significantly different.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-four sheep shoulders were assigned to 3 repair groups of full-thickness infraspinatus tears: group 1, traditional double-row repair; group 2, DLDR anchor repair with simple suture configuration; and group 3, DLDR knotless repair with mattress suture configuration. After ultrasound evaluation of the repair, each specimen was cyclically loaded with 10 to 100 N for 50 cycles. Each specimen was then loaded to failure at a rate of 1 mm/s.

RESULTS

There were no statistically significant differences among the 3 testing groups for the mean footprint area. The cyclic loading test revealed no significant difference among the 3 groups with regard to elongation. For the load-to-failure test, groups 2 and 3 showed no differences in ultimate tensile load when compared with group 1. However, when compared to group 2, group 3 was found to have significantly higher values regarding ultimate load, ultimate elongation, and energy absorbed.

CONCLUSION

The DLDR fixation techniques may provide strength of initial repair comparable with that of commonly used double-row techniques. When compared with the knotless technique with mattress sutures, simple suture configuration of DLDR repair may be too weak. Knotless DLDR rotator cuff repair may (1) restore the footprint by the use of double-row principles and (2) enable restoration of the shape and profile.

CLINICAL RELEVANCE

Double-layer double-row fixation in mattress suture configuration has initial fixation strength comparable with that of the classic double-row fixation and so may potentially improve functional results of rotator cuff repair.

Rotator cuff tears: pathology and repair

By virtue of its anatomy and function, the rotator cuff is vulnerable to considerable morbidity, often necessitating surgical intervention. The factors contributing to cuff disease can be divided into those extrinsic to the rotator cuff (most notably impingement) and those intrinsic to the cuff (age-related degeneration, hypovascularity and inflammation amongst others). In an era of emerging biologic interventions, our interventions are increasingly being modulated by our understanding of these core processes, many of which remain uncertain today. When we do intervene surgically, the techniques we employ are particularly challenging in the context of the tremendous pace of advancement. Several recent studies have shown that arthroscopic repair gives similar functional results to that of mini-open and open procedures, with all the benefits of minimally invasive surgery. However, the 'best' repair construct remains unknown, with wide variations in surgeon preference. Here we present a literature review encompassing recent developments in our understanding of basic science in rotator cuff disease as well as an up-to-date evidence-based comparison of different techniques available to the surgeon for cuff repair.

A prospective randomized clinical trial comparing arthroscopic single- and double-row rotator cuff repair: magnetic resonance imaging and early clinical evaluation

BACKGROUND

Double-row arthroscopic rotator cuff repair has become more popular, and some studies have shown better footprint coverage and improved biomechanics of the repair.

HYPOTHESIS

Double-row rotator cuff repair leads to superior cuff integrity and early clinical results compared with single-row repair.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Forty patients were randomized to either single-row or double-row rotator cuff repair at the time of surgical intervention. Patients were followed with clinical measures (UCLA, Constant, WORC, SANE, ASES, as well as range of motion, internal rotation strength, and external rotation strength). Magnetic resonance imaging (MRI) studies were performed on each shoulder preoperatively, 6 weeks, 3 months, and 1 year after repair.

RESULTS

Mean anteroposterior tear size by MRI was 1.8 cm. A mean of 2.25 anchors for single row (SR) and 3.2 for double row (DR) were used. There were 2 retears at 1 year in each group. There were 2 additional cases that had severe thinning in the DR repair group at 1 year. The MRI measurements of footprint coverage, tendon thickness, and tendon signal showed no significant differences between the 2 repair groups. At 1 year, there were no differences in any of the postoperative measures of motion or strength. At 1 year, mean WORC (SR, 84.8; DR, 87.9), Constant (SR, 77.8; DR, 74.4), ASES (SR, 85.9; DR, 85.5), UCLA (SR, 28.6; DR, 29.5), and SANE (SR, 90.9; DR, 89.9) scores showed no significant differences between groups.

CONCLUSIONS

No clinical or MRI differences were seen between patients repaired with a SR or DR technique.

Differential suture loading in an experimental rotator cuff repair

BACKGROUND

Repairs of large rotator cuff tears often fail to heal. A possible factor in these failures is excessive tension in the repair sutures, causing them to pull through the tendon.

HYPOTHESIS

Arm positions encountered during early rehabilitation after cuff repair can dramatically increase the relative tension in the different sutures of the cuff repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

In a cadaver model, a 4-suture supraspinatus repair was carried out with transosseous sutures. After the repair, the arm was placed in 12 different positions. The tension in each suture was monitored using individual load cells.

RESULTS

When the arm was externally rotated relative to the plane of the scapula, the tension in the anterior suture was over 10 times that in the posterior suture (P < .001). When the arm was internally rotated, the tension in the posterior suture was over 10 times that in the anterior suture (P < .0005). When the arm was in neutral rotation, there was no significant difference in the suture tension.

CONCLUSIONS

This study is the first report of direct suture tension measurement after a model rotator cuff repair. In this model, 30 degrees of either internal or external rotation of the arm in relation to the plane of the scapula created substantial imbalances in the tension between the most anterior and most posterior sutures of a supraspinatus repair, regardless of the position of abduction.

CLINICAL RELEVANCE

Avoiding external rotation stretching during the healing of supraspinatus repairs may prevent tension overload in the critical anterior suture.

An in vitro analysis of the mechanical properties of 16 arthroscopic knots

The purpose of this study was to determine the biomechanical characteristics of 16 arthroscopic knots and to determine if locking knots have superior loop security compared to non-locking knots. Sixteen knot types were tied in arthroscopic fashion and tested on a materials testing system. Knots were cyclically loaded to 30 Newtons (N) for 20 cycles and then loaded to failure at 1.25 mm/s. Ten samples of each knot were tied using both #2 Ethibond and #1 PDS II. Load to ultimate failure, load to clinical failure, post-cyclic stiffness, cyclical elongation, ultimate displacement, loop security, and mode of failure were determined for each knot. Nicky's Knot and the French Knot were most consistently ranked within the top five knot types for each of the biomechanical parameters. Locking knots did not improve loop security over non-locking knots.

The pathogenesis and surgical treatment of tears of the rotator cuff

This review discusses the pathogenesis and surgical treatment of tears of the rotator cuff.

A biomechanical comparison of 2 technical variations of double-row rotator cuff fixation: the importance of medial row knots

BACKGROUND

Previous studies have shown comparable biomechanical properties of double-row fixation versus double-row fixation with a knotless lateral row. SutureBridge is a construct that secures the cuff with medial row mattress suture anchors and knotless lateral row fixation of the medial suture ends. Recent completely knotless constructs may lead to lesser clinical outcomes if the construct properties are compromised from lack of suture knots.

HYPOTHESIS

A completely knotless construct without medial row knots will compromise the biomechanical properties in both cyclic and failure-testing parameters.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six matched pairs of cadaveric shoulders were randomized to 2 groups of double row fixation with SutureBridge: group 1 with medial row knots, and group 2 without medial row knots. The specimens were placed in a materials test system at 30 degrees of abduction. Cyclic testing to 180 N at 1 mm/sec for 30 cycles was performed, followed by tensile testing to failure at 1 mm/sec.

RESULTS

Data included cyclic and failure data from the materials test system and gap data using a video digitizing system. All data from paired specimens were compared using paired Student t tests. Group 1 had a statistically significant difference (P < .05) for gap formation for the 1st (3.47 vs 5.05 mm) and 30th cycle (4.22 vs 8.10 mm) and at yield load (5.2 vs 9.1 mm). In addition, there was a greater energy absorbed (2805 vs 1648 N-mm), yield load (233 vs 183.1 N), and ultimate load (352.9 vs 253.9 N) for group 1. The mode of failure for the majority (4/6) of group 2 was lateral row failure, whereas all group 1 specimens failed at the clamp.

CONCLUSION

Although lateral row knotless fixation has been shown not to sacrifice structural integrity of this construct, the addition of a knotless medial row compromises the construct leading to greater gapping and failure at lower loads.

CLINICAL RELEVANCE

This may raise concerns regarding recently marketed completely knotless double row constructs.