Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal?

Strategies in biologic augmentation of rotator cuff repair: a review

BACKGROUND

Degenerative rotator cuff tears are increasing with the aging population, and healing is not uniform after surgery. Rotator cuffs may show improved healing when biologic factors are added during surgery.

QUESTIONS/PURPOSES

We asked: (1) What cellular processes are involved in normal bone-to-tendon healing? (2) What approaches are being developed in tendon augmentation? (3) What approaches are being developed with the addition of growth factors?

METHODS

We reviewed research in relating to biologic augmentation and cellular processes involved in rotator cuff repair, focusing on animal models of rotator cuff repair and nonrandomized human trials.

RESULTS

Regular bone-to-tendon healing forms a fibrous junction between tendon and bone that is distinct from the original bone-to-tendon junction. Tendon augmentation with cellular components serves as scaffolding for fibroblastic cells and a possible source of growth factors and fibroblastic cells. Extracellular matrices provide a scaffold for incoming fibroblastic cells, although current research does not conclusively confirm which if any of these scaffolds enhance repair owing in part to intermanufacturer variations and the limited human research. Growth factors and platelet-rich-plasma are established in other fields of research and may enhance repair but have not been rigorously tested.

CONCLUSIONS

There is potential application of biologic augmentation to improve healing after rotator cuff repair. However, research in this field is still inconclusive and has not been sufficiently demonstrated to merit regular clinical use. Future human trials can elucidate the use of biologic augmentation in rotator cuff repairs.

Biomechanical comparison of transosseous versus suture anchor repair of the subscapularis tendon

PURPOSE

The purpose of this study was to compare the biomechanical properties of transosseous versus suture anchor repair of the subscapularis tendon. We also performed real-time measurement of contact area and pressure of the repair site under rotational loads.

METHODS

Six paired human cadaveric shoulders were subjected to rotational loading after repair of the subscapularis tendon. Both shoulders were randomized to transosseous or suture anchor repairs. Real-time pressure sensors were placed between the subscapularis tendon and lesser tuberosity. The repair was subjected to cyclical rotational loading and load-to-failure testing.

RESULTS

No significant difference was detected in initial pressurized contact area between transosseous repairs (1.70 +/- 0.99 cm(2), 57.88 +/- 30.02% footprint) and suture anchor repairs (1.08 +/- 0.58 cm(2), 34.26% +/- 17.32% footprint). Under cyclical loading, the conditioning elongation of transosseous repairs (0.64 +/- 0.40 mm) was significantly lower (P < .05) than that of suture anchor repairs (2.38 +/- 1.58 mm). No significant difference was found in mean pressurized contact area between the transosseous repairs (2.72 +/- 1.25 cm(2), 94.2% +/- 37.4% footprint) and suture anchor repairs (2.01 +/- 0.89 cm(2), 65.9% +/- 27.9% footprint). For suture anchor repairs, repair-site contact area was significantly (P < .05) smaller than the area of corresponding native insertional footprints; for transosseous repairs, no significant difference was detected. There were no significant differences in peak pressures between the 2 repairs. In the load-to-failure tensile test, there was no significant difference between transosseous repairs (453.2 +/- 66.1 N) and suture anchor repairs (392.6 +/- 78.0 N).

CONCLUSIONS

Transosseous and suture anchor repairs of the subscapularis tendon have comparable biomechanical properties. Despite increased conditioning elongation in suture anchor repairs, we found no significant differences in mean contact area between the 2 repairs under cyclical loading. The suture anchor repairs do have a smaller contact area than the native insertional area. Real-time pressure and contact area measurements enabled mapping of the repair site throughout cyclical loading.

CLINICAL RELEVANCE

Rotational loading of the subscapularis tendon may provide a more accurate representation of subscapularis tendon injuries. Both techniques showed adequate repair strength; however, neither surgical technique exhibited normal insertional behavior in this time-zero biomechanical study.

Does the literature confirm superior clinical results in radiographically healed rotator cuffs after rotator cuff repair?

PURPOSE

Because recurrent or persistent defects in the rotator cuff after repair are common, we sought to clarify the correlation between structural integrity of the rotator cuff and clinical outcomes through a systematic review of relevant studies.

METHODS

Medline, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and the Cochrane Central Register of Controlled Trials were searched for all literature published from January 1966 to December 2008 that used the key words shoulder, rotator cuff, rotator cuff tear, rotator cuff repair, arthroscopic, integrity, healed, magnetic resonance imaging (MRI), computed tomography arthrography (CTA), and ultrasound. The inclusion criteria were studies (Levels I to IV) that reported outcomes after arthroscopic rotator cuff repair in healed and nonhealed repairs based on ultrasound, CTA, and/or MRI. Exclusionary criteria were studies that included open repair or subscapularis repair and studies that did not define outcomes based on healed versus nonhealed but rather used another variable (i.e., repair technique). Data were abstracted from the studies including patient demographics, tear characteristics, surgical procedure, rehabilitation, strength, range of motion, clinical scoring systems, and imaging studies.

RESULTS

Thirteen studies were included in the final analysis: 5 used ultrasound, 4 used MRI, 2 used CTA, and 2 used combined CTA/MRI for diagnosis of a recurrent tear. Statistical improvement in patients who had an intact cuff at follow-up was seen in Constant scores in 6 of 9 studies; in University of California, Los Angeles scores in 1 of 2 studies; in American Shoulder and Elbow Surgeons scores in 0 of 3 studies; and in Simple Shoulder Test scores in 0 of 2 studies. Increased range of motion in forward elevation was seen in 2 of 5 studies and increased strength in forward elevation in 5 of 8 studies.

CONCLUSIONS

The results suggest that some important differences in clinical outcomes likely exist between patients with healed and nonhealed rotator cuff repairs. Further study is needed to conclusively define this difference and identify other important prognostic factors related to clinical outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review.

Arthroscopic rotator cuff repair: scientific rationale, surgical technique, and early clinical and functional results of a knotless self-reinforcing double-row rotator cuff repair system

BACKGROUND

Rotator cuff repair has shown to improve shoulder function and reduce pain experienced by patients. Successful repairs should have high fixation strength, allow minimal gap formation, maintain stability, and restore normal anatomy and function of the supraspinatus footprint. The purpose of this study is to describe our preferred method for rotator cuff repair using a knotless self-reinforcing double-row system, and to cite biomechanical data rationalizing its use.

METHODS AND MATERIAL

Seventeen of 22 patients were identified as undergoing primary rotator cuff repair with minimum follow-up of 1 year (mean, 535 days; range, 370-939). The average age was 63 (range, 43-79). Data collected included average pain today, average worst pain, Single Assessment Numeric Evaluation (SANE), and patient satisfaction.

RESULTS

For all patients, average pain today and average worst pain decreased and functional scores (SANE) increased. Patient satisfaction was 9.8 out of 10 (range, 7-9). The patients also began rehabilitation earlier and returned to full activities at 4 months.

CONCLUSION

These results indicate that the knotless self-reinforcing double-row repair system is a viable option in treating rotator cuff tears. This system provides improved contact area and restores the native footprint of the tendon leading to better outcomes.

Arthroscopic repair of full-thickness rotator cuff tears: is there tendon healing in patients aged 65 years or older?

PURPOSE

The aim of this study was to assess tendon healing and clinical results of rotator cuff tears (RCTs) repaired arthroscopically in patients aged 65 years or older.

METHODS

Between January 2001 and December 2004, 88 patients with a mean age of 70 years (range, 65 to 85 years) had arthroscopic RCT repair. The repair was performed on 54 women (61%). The dominant arm was involved in 72 patients (82%). RCT included more than 2 tendons in 45 cases. Functional outcomes were assessed by use of the Constant score and Simple Shoulder Test. Tendon healing was estimated by use of a computed tomography (CT) arthrogram, which was obtained 6 months postoperatively, and was classified into 3 categories: stage 1, watertight and anatomic healing; stage 2, watertight and partial healing; and stage 3, not watertight and retear.

RESULTS

The mean duration of follow-up was 41 months (range, 24 to 77 months). The mean clinical outcome scores all improved significantly at the time of the final follow-up (P < .01). Computed tomography arthrogram imaging showed 27 shoulders with a stage 1 repair, 20 with a stage 2 repair, and 34 with a stage 3 repair. The retear rate was 42% (34 of 81). The patients with tendon healing stage 1 or 2 had a significantly superior functional outcome in terms of overall scores and strength compared with the stage 3 repairs (P < .01). In our study we had 39 isolated supraspinatus tears (small or medium tears); 11 (28.9%) had a retear (stage 3).

CONCLUSIONS

Arthroscopic repair in patients aged 65 years or older can yield tendon healing resulting in significant functional improvement. Our data suggest that arthroscopic repair can be considered successful for the older patient specifically when the tear is limited to the supraspinatus tendon.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Vascularity of the supraspinatus tendon three months after repair: characterization using contrast-enhanced ultrasound

BACKGROUND

There has been limited in-vivo assessment of rotator cuff vascularity following repair. This study aims to characterize the vascularity of the shoulder 3 months following supraspinatus tendon repair.

METHODS

Twenty-nine patients (average age, 61.4 years) underwent Perflutren lipid microsphere contrast-enhanced shoulder ultrasound examinations 3 months after arthroscopic rotator cuff repair. Each shoulder was scanned at rest and following exercise using linear phased array 9-MHz transducer optimized to detect the contrast agent. Blood flow was quantified off-line using ultrasound imaging quantification and analysis software (QLAB, Philips, Andover, MA). Peak enhancement (vascular volume) and rate of rise (perfusion) were determined for 3 regions of interest: peribursal area, supraspinatus tendon, and anchor site.

RESULTS

Peak enhancement and rate of rise were greatest in the peribursal soft tissue and anchor site. Resting peak enhancement and rate of rise were significantly lower within the tendon compared to the other 2 regions (P < .001). Exercise resulted in increased enhancement and rate-of-rise to all 3 regions, but had a significant predilection towards increasing vascular volume within the peri-bursal region (P = .026).

CONCLUSION

At 3 months following repair, the majority of blood flow to the repair is derived from the peribursal soft tissues and the anchor site. The tendon, particularly those with a defect at 3 months, is relatively avascular. Though limited by inclusion of only a single time point, this study introduces a new technique to quantify vascularity following supraspinatus repairs and suggests that the surrounding vascular milieu may play a role in tendon healing.

LEVEL OF EVIDENCE

Basic Science.

Clinical outcomes of arthroscopic single and double row repair in full thickness rotator cuff tears

BACKGROUND

There has been a recent interest in the double row repair method for arthroscopic rotator cuff repair following favourable biomechanical results reported by some studies. The purpose of this study was to compare the clinical results of arthroscopic single row and double row repair methods in the full-thickness rotator cuff tears.

MATERIALS AND METHODS

22 patients of arthroscopic single row repair (group I) and 25 patients who underwent double row repair (group II) from March 2003 to March 2005 were retrospectively evaluated and compared for the clinical outcomes. The mean age was 58 years and 56 years respectively for group I and II. The average follow-up in the two groups was 24 months. The evaluation was done by using the University of California Los Angeles (UCLA) rating scale and the shoulder index of the American Shoulder and Elbow Surgeons (ASES).

RESULTS

In Group I, the mean ASES score increased from 30.48 to 87.40 and the mean ASES score increased from 32.00 to 91.45 in the Group II. The mean UCLA score increased from the preoperative 12.23 to 30.82 in Group I and from 12.20 to 32.40 in Group II. Each method has shown no statistical clinical differences between two methods, but based on the sub scores of UCLA score, the double row repair method yields better results for the strength, and it gives more satisfaction to the patients than the single row repair method.

CONCLUSIONS

Comparing the two methods, double row repair group showed better clinical results in recovering strength and gave more satisfaction to the patients but no statistical clinical difference was found between 2 methods.

Clinical outcomes of double-row versus single-row rotator cuff repairs

PURPOSE

The purpose of this review was to determine whether there is a difference in the clinical outcome between single-row and double-row rotator cuff repairs.

METHODS

We performed a systematic review of the results of clinical studies investigating and comparing double-row and single-row repair techniques. The articles meeting the inclusion and exclusion criteria were assessed for quality of the study; the results were then reviewed to provide a concise conclusion regarding the clinical outcomes of double-row versus single-row rotator cuff repair.

RESULTS

There were 3 Level I studies and 2 Level II studies comparing the clinical outcomes of double-row and single-row rotator cuff repair. At 1-year follow-up, there was no statistically significant clinical difference between patients who had undergone double-row repair and those who had undergone single-row rotator cuff repair.

CONCLUSIONS

Arthroscopic rotator cuff repairs with double-row repair show no significant difference compared with single-row repair in clinical outcome at 1-year follow-up. Additional prospective, randomized controlled trials are needed with longer-term follow-up to determine whether there is any clinical difference between the 2 techniques.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Does the literature support double-row suture anchor fixation for arthroscopic rotator cuff repair? A systematic review comparing double-row and single-row suture anchor configuration

PURPOSE

The purpose of this study was to compare the clinical outcome of single-row (SR) and double-row (DR) suture anchor fixation in arthroscopic rotator cuff repair with a systematic review of the published literature.

METHODS

We searched all published literature from January 1966 to December 2008 using Medline, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and the Cochrane Central Register of Controlled Trials for the following key words: shoulder, rotator cuff, rotator cuff tear, rotator cuff repair, arthroscopic, arthroscopic-assisted, single row, double row, and transosseous equivalent. The inclusion criteria were cohort studies (Levels I to III) that compared SR and DR suture anchor configuration for the arthroscopic treatment of full-thickness rotator cuff tears. The exclusion criteria were studies that lacked a comparison group, and, therefore, case series were excluded from the analysis.

RESULTS

There were 5 studies that met the criteria and were included in the final analysis: 5 in the SR group and 5 in the DR group. Data were abstracted from the studies for patient demographics, rotator cuff tear characteristics, surgical procedure, rehabilitation, range of motion, clinical scoring systems, and imaging studies.

CONCLUSIONS

There are no clinical differences between the SR and DR suture anchor repair techniques for arthroscopic rotator cuff repairs. At present, the data in the published literature do not support the use of DR suture anchor fixation to improve clinical outcome, but there are some studies that report that DR suture anchor fixation may improve tendon healing.

LEVEL OF EVIDENCE

Level III, systematic review of Levels I to III studies.

Rotator cuff integrity after arthroscopic repair for large tears with less-than-optimal footprint coverage

PURPOSE

The purpose of this study was to evaluate the clinical results and healing status of rotator cuff repairs with less than 50% footprint coverage.

METHODS

During the 18-month period from October 2005 to March 2007, 89 large to massive rotator cuff tears were arthroscopically repaired. Among them, 23 consecutive large to massive rotator cuff tears were repaired completely but with less than 50% of the original footprint. All tears were arthroscopically repaired with suture anchors. Preoperative and postoperative clinical assessments were performed with the Constant score, American Shoulder and Elbow Surgeons score, and pain visual analog scale. The healing status of repaired tendon was evaluated by postoperative magnetic resonance imaging with a focus on tendon integrity, muscle fatty degeneration, and muscle atrophy.

RESULTS

The mean follow-up period was 30.2 months (range, 24 to 41 months). At final follow-up visits, American Shoulder and Elbow Surgeons score, Constant score, and score on pain visual analog scale were found to have improved significantly from 40.1, 35.9, and 57.7 to 82.4, 86.6, and 12.3, respectively (P < .01). The overall retear rate was 45.5% (10 cases). However, clinical results showed no difference between the retear group and no retear group. Furthermore, rerupture size was smaller than original tear size in all 10 patients, and no significant progression of fatty degeneration or muscle atrophy of rotator cuff muscles was observed.

CONCLUSIONS

Less-than-optimal coverage of the original greater tuberosity footprint during arthroscopic repair of large to massive rotator cuff tears was found to be associated with a relatively high retear rate (45.5%). However, clinical results improved significantly, and no significant difference was observed in the clinical results between the retear and no retear groups.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Incidence and treatment of postoperative stiffness following arthroscopic rotator cuff repair

PURPOSE

The purpose of this study was to determine the incidence of clinically significant postoperative stiffness following arthroscopic rotator cuff repair. This study also sought to determine the clinical and surgical factors that were associated with higher rates of postoperative stiffness. Finally, we analyzed the result of arthroscopic lysis of adhesions and capsular release for treatment of patients who developed refractory postoperative stiffness 4 to 19 months (median, 8 months) following arthroscopic rotator cuff repair.

METHODS

A retrospective review of a consecutive series of arthroscopic rotator cuff repairs was conducted. During a 3-year time period, the senior author (S.S.B.) performed 489 arthroscopic rotator cuff repairs. The operative indications, technique of the rotator cuff repair, and the rehabilitation protocol were essentially unchanged during this time period. Demographic data, comorbid medical conditions, rotator cuff tear description, technique of repair, and concomitant surgical procedures were evaluated for their effect on stiffness. All office evaluations were reviewed to determine the pre- and postoperative motion, pain scores, functional strength, and patient satisfaction. Patients who were dissatisfied because of the development of postoperative stiffness underwent secondary arthroscopic lysis of adhesions. The final result of the secondary lysis of adhesions and capsular release were analyzed.

RESULTS

In total, 24 patients (4.9%) were dissatisfied with the result of their procedure because of the development of postoperative stiffness, which was more likely (P < .05) to develop in patients with Workers' Compensation insurance (8.6%), patients younger than 50 years of age (8.6%), those with a coexisting diagnosis of calcific tendonitis (16.7%) or adhesive capsulitis (15.0%) requiring additional postoperative therapy, partial articular-sided tendon avulsion (PASTA) type rotator cuff tear (13.5%), or concomitant labral repair (11.0%). Patients with concomitant coracoplasty (2.3%) or tears larger in size and/or involving more tendons were less likely (P < .05) to develop postoperative stiffness. Among 90 patients positive for selected risk factors (adhesive capsulitis, excision of calcific deposits, single-tendon repair, PASTA repair, or any labral repair without a concomitant coracoplasty), 12 (13.3%) developed postoperative stiffness (P < .001). This overall clinical risk factor combined with Workers' Compensation insurance identified 16 of the 24 cases resulting in a sensitivity of 66.7% and a specificity of 64.5%. All 24 patients who experienced postoperative stiffness elected to undergo arthroscopic lysis of adhesions and capsular release, which was performed from 4 to 19 months (median, 8 months) after the rotator cuff repair. During second-look arthroscopy, 23 patients (95.8%) were noted to have complete healing of the original pathology. Following capsular release, all 24 patients were satisfied with the overall result of their treatment.

CONCLUSIONS

In a series of 489 consecutive arthroscopic rotator cuff repairs, we found that 24 patients (4.9%) developed postoperative stiffness. Risk factors for postoperative stiffness were calcific tendinitis, adhesive capsulitis, single-tendon cuff repair, PASTA repair, being under 50 years of age, and having Workers' Compensation insurance. Twenty-three of 24 patients (95.8%) showed complete healing of the rotator cuff. Arthroscopic release resulted in normal motion in all cases.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Correlations of isokinetic measurements with tendon healing following open repair of rotator cuff tears

The aim of this study was to investigate the correlation of tendon integrity following open cuff repairs with functional and isokinetic strength measurements. Twenty-six shoulders of 25 patients were included in this study. At the final follow-up, 14 repairs (53.8%) were intact and 12 repairs (46.2%) had failed on magnetic resonance imaging (MRI). Mean UCLA score at latest follow-up was 28.5 and mean Constant score was 80.3. Constant scores were found to be significantly low for the failed group. Age was found to be significantly related to failed repair. Fatty infiltration stage in the failed repair group was significantly high, and a strong positive correlation for both groups existed pre and postoperatively. When both groups were compared, the failed group was found to have significantly low measurements at extension and internal rotation. Despite high failure rates, functional results were satisfactory. Increased age and fatty infiltration stage decrease success.

Impingement syndrome of the shoulder following double row suture anchor technique for arthroscopic rotator cuff repair: a case report

Introduction

Arthroscopic repair of the rotator cuff is a demanding surgery. Accurate placement of anchors is key to success.

Case presentation

A 38-year-old woman received arthroscopic repair of her rotator cuff using a double row suture anchor technique. Postoperatively, she developed impingement syndrome which resulted from vertical displacement of a suture anchor once the shoulder was mobilised. The anchor was removed eight weeks following initial surgery and the patient had an uneventful recovery.

Conclusion

Impingement syndrome following arthroscopic repair of the rotator cuffs using double row suture anchor has not been widely reported. This is the first such case where anchoring has resulted in impingement syndrome.

Massive rotator cuff tears in patients younger than 65 years. Epidemiology and characteristics

Currently, there is little information on the clinical, radiographic and electric profile of patients younger than 65 years of age with large rotator cuff tear. According to our hypothesis, massive rotator cuff tear, when discovered after recent traumatism, do not provide typical radiographic findings and suprascapular nerve impairment in large rotator cuff tears is uncommon. This is a prospective, descriptive, multicenter study of a series of 112 patients younger than 65 years, including 66 males and 46 females with extensive or massive cuff tear. Duration of symptoms was less than 6 months in 28 cases and secondary to trauma in 57 cases. Patients had loss of elevation or external rotation or both in 57 cases. An electromyogram (EMG) of suprascapular nerve was performed in 50 cases. A higher incidence of advanced fatty infiltration of the infraspinatus muscle (>stage 2 according to Goutallier) was observed in case of long-term symptomatology or in the absence of known trauma. Traumatic status was commonly found in patients with functional deficit in shoulder elevation, thus reporting a significantly lower Constant score (p<0.0001). Patients with both loss of shoulder elevation and external rotation had a significantly narrower subacromial space (5 mm versus 7.2 mm). No significant relationship could be established between electric impairment and massive cuff tear. According to the present study, in case of traumatic context and recent symptomatology, subacromial height and fatty infiltration of the infraspinatus muscle are better prognostic factors despite a pseudoparalytic shoulder. Repair should thus be considered. Moreover, the interest of a preoperative suprascapular nerve EMG is questionable.

The effect of the angle of suture anchor insertion on fixation failure at the tendon-suture interface after rotator cuff repair: deadman's angle revisited

PURPOSE

To evaluate what effect the angle of screw-in suture anchor insertion has on fixation stability at the suture-tendon interface.

METHODS

Supraspinatus tendons from 7 matched pairs of human cadaveric shoulders were split, yielding 4 tendons per cadaver. An experimental rotator cuff tear was created and repaired, using a 5.0-mm diameter screw-in suture anchor. In a staggered, matched pair arrangement, the angle of anchor insertion was varied between 45 degrees (deadman's angle) and 90 degrees to the articular surface. Each repair underwent cyclic loading, and 2 failure points were defined: the first at 3 mm of repair site gap formation and the second at the point of complete failure. The number of cycles to failure was compared between the 2 groups.

RESULTS

The mean number of cycles to 3-mm gap formation for anchors inserted at 90 degrees was 380. This was significantly higher than for repairs made with the 45 degrees angle of anchor insertion (mean, 297 cycles). Complete failure occurred at a significantly greater number of cycles with the 90 degrees anchors (mean, 443 cycles) compared with the 45 degrees anchors (mean, 334 cycles).

CONCLUSIONS

Compared with anchors placed at the current standard of the deadman's angle of 45 degrees, suture anchors placed at 90 degrees to the junction of the greater tuberosity and the humeral head articular surface provided improved soft tissue fixation in an experimental rotator cuff model.

CLINICAL RELEVANCE

The angle of suture anchor insertion into the greater tuberosity during rotator cuff repair has an effect on the soft tissue fixation at the tendon-suture interface.

A prospective therapeutic comparison of simple suture repairs to massive cuff stitch repairs for treatment of small- and medium-sized rotator cuff tears

PURPOSE

The purpose of this study was to compare the massive cuff stitch (MCS) with the simple stitch in terms of integrity at 2 years after surgery when used to repair small-sized to medium-sized full-thickness rotator cuff tears.

METHODS

Seventy-one patients underwent arthroscopic repair of full-thickness rotator cuff tears between December 2004 and June 2006. The tear sizes ranged from 0.5 to 1.5 cm. The mean patient age was 53 years (range, 40 to 69 years), and the mean follow-up time was 33 months (range, 24 to 41 months). Group I (n = 35) underwent MCS repair, and group II (n = 36) underwent simple stitch repair. Results were analyzed by use of the Wilcoxon signed rank test and the Mann-Whitney test. Follow-up ultrasound was performed 24 to 41 months after repair.

RESULTS

All patients showed improvements in the visual analog scale for pain, activities of daily living, and University of California, Los Angeles scores (P < .05), but there were no significant differences in scores between groups (P > .05). The satisfaction rating was similar for group I (4.7) and group II (4.3) (P > .05). The failure (retear) rate was significantly lower in group I (14.3%) than in group II (27.8%) (P < .05).

CONCLUSIONS

The clinical outcomes between the MCS and simple stitch were not significantly different, but the MCS was superior to the simple stitch in maintaining repair integrity on ultrasound evaluation after arthroscopic repair of small-sized to medium-sized full-thickness rotator cuff tears.

LEVEL OF EVIDENCE

Level III, prospective therapeutic comparative study.

Massive rotator cuff tears in patients younger than 65 years. What treatment options are available?

Management of massive rotator cuff tears is a therapeutic challenge in patients younger than 65 years, particularly if still working. According to our hypothesis, choice of the most appropriate treatment option mainly depends on the patient's functional status and on two predictive factors: height of the subacromial space and fatty muscle infiltration. This is a retrospective, multicenter study of a series of 296 patients younger than 65 years, including 176 males and 120 females with extensive or massive cuff tear. Patients had loss of elevation or external rotation or both in 162 cases. Four types of management of massive rotator cuff tear were performed in this study: anatomical watertight repairs, palliative treatments and partial repairs, watertight repairs using flaps or cuff prostheses and reverse shoulder prostheses. At follow-up, the Constant score (65.6+/-3.4) and active elevation (147.7 degrees +/-32 degrees) had significantly improved. Active external rotation with elbow at the side, and acromiohumeral interval (AHI) were unchanged. Work-related injuries, previous surgeries and complications were correlated with a poorer Constant score. At follow-up, the anatomical repair sub-group had a significantly better Constant score than the three other treatment groups but involved patients with unchanged AHI and a low degree of fatty infiltration of the infraspinatus muscle. The reverse shoulder prostheses sub-group showed better outcomes in terms of function benefits. The presence of a long biceps was correlated with the use of a palliative treatment. In the light of the results and literature, an approach to treatment is suggested related to the functional capacity of patients, the AHI and the degree of fatty infiltration of the infraspinatus and subscapularis muscles.

The factors affecting the clinical outcome and integrity of arthroscopically repaired rotator cuff tears of the shoulder

Background

The purpose of this study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repair, and to analyze the factors affecting the integrity of arthroscopically repaired rotator cuff tears of the shoulder.

Methods

One hundred sixty-nine consecutive shoulders that underwent arthroscopic rotator cuff repair, had a postoperative MRI evaluation and were followed for at least two years were enrolled in this study. The mean age was 57.6 years (range, 38 to 74 years) and the mean follow-up period was 39 months (range, 24 to 83 months).

Results

The rotator cuff was completely healed in 131 (77.5%) out of 169 shoulders and recurrent tears occurred in 38 shoulders (22.5%). At the last follow-up visit, the mean score for pain during motion was 1.53 (range, 0 to 4) in the completely healed group and 1.59 (range, 0 to 4) in the group with recurrent tears (p = 0.092). The average elevation strength was 7.87 kg (range, 4.96 to 11.62 kg) and 5.25 kg (range, 4.15 to 8.13 kg) and the mean University of California at Los Angeles score was 30.96 (range, 26 to 35) and 30.64 (range, 23 to 34), respectively (p < 0.001, p = 0.798). The complete healing rate was 87.8% in the group less than 50 years of age (49 shoulders), 79.4% in the group over 51 years but less than 60 years of age (68 shoulders), and 65.4% in the group over 61 years of age (52 shoulders, p = 0.049); it was 96.7% in the group with small-sized tears (30 shoulders), 87.3% in the group with medium-sized tears (71 shoulders), and 58.8% in the group with large-sized or massive tears (68 shoulders, p = 0.009). All of the rotator cuffs with a global fatty degeneration index of greater than two preoperatively had recurrent tears.

Conclusions

Arthroscopic repair of full-thickness rotator cuff tears led to a relatively high rate of recurrent defects. However, the minimum two-year follow up demonstrated excellent pain relief and improvement in the ability to perform the activities of daily living, despite the structural failures. The factors affecting tendon healing were the patient's age, the size and extent of the tear, and the presence of fatty degeneration in the rotator cuff muscle.

Complete removal of load is detrimental to rotator cuff healing

HYPOTHESIS

This study evaluated the effect of the mechanical environment on the healing rotator cuff by paralyzing the supraspinatus muscle in the operative shoulder of a rat model of rotator cuff injury and repair.

METHODS

Unilateral shoulders of rats underwent a supraspinatus injury and repair. Botulinum toxin A was used to paralyze the muscle after repair. Postoperatively, 1 group was immobilized and 1 group was allowed free range of motion. Saline-injected, casted rats were used as the control group. Repairs were evaluated histologically, geometrically, and biomechanically.

RESULTS

Specimens from the saline-injected rats had greater scar volume and cross-sectional area of the repair compared with the paralyzed groups. Structural properties were increased in the saline group compared with the paralyzed groups. Free range of motion (ie, uncasted group) resulted in modest improvements in biomechanical properties but did not obviate the effect of paralysis.

CONCLUSIONS

Complete removal of load was detrimental to rotator cuff healing, especially when combined with immobilization.

The effect of a local application of fibroblast growth factor-2 on tendon-to-bone remodeling in rats with acute injury and repair of the supraspinatus tendon

METHODS

We investigated the effect of application of fibroblast growth factor (FGF)-2 on the tendon-to-bone remodeling of repaired supraspinatus tendon in rats subjected to bilateral detachment. FGF-2 (100 mg/kg) in a fibrin sealant or sealant alone was applied on the right and left shoulders, respectively. Twelve animals each at 2, 4, and 6 weeks after surgery were sacrificed for histological analysis (n = 5) and biomechanical Q1 testing (n = 7).

RESULTS

Histologically, at 2 weeks, FGF-treated specimens had significantly higher tendon-to-bone insertion maturing scores then untreated specimens (P < .002). At 4 and 6 weeks, the scores of FGF-treated and untreated specimens were similar (P > .05). Biomechanically, FGF-treated specimens were stronger at 2 weeks (P = .001); at 4 and 6 weeks, both specimens exhibited similar strength (P > .05).

CONCLUSIONS

The initial tendon-to-bone remodeling was accelerated by a local application of FGF-2. This may represent a clinically important improvement in rotator cuff repair.

Rotator cuff repair augmentation in a canine model with use of a woven poly-L-lactide device

BACKGROUND

Despite advances in surgical treatment options, failure rates of rotator cuff repair have continued to range from 20% to 90%. Hence, there is a need for new repair strategies that provide effective mechanical reinforcement of rotator cuff repair as well as stimulate and enhance the intrinsic healing potential of the patient. The purpose of this study was to evaluate the extent to which augmentation of acute repair of rotator cuff tendons with a newly designed poly-L-lactide repair device would improve functional and biomechanical outcomes in a canine model.

METHODS

Eight adult, male mongrel dogs (25 to 30 kg) underwent bilateral shoulder surgery. One shoulder underwent tendon release and repair only, and the other was subjected to release and repair followed by augmentation with the repair device. At twelve weeks, tendon retraction, cross-sectional area, stiffness, and ultimate load of the repair site were measured. Augmented repairs underwent histologic assessment of biocompatibility. In addition, eight pairs of canine cadaver shoulders underwent infraspinatus injury and repair with and without device augmentation with use of identical surgical procedures and served as time-zero biomechanical controls. Eight unpaired, canine cadaver shoulders were included as normal biomechanical controls.

RESULTS

At time zero, repair augmentation significantly increased the ultimate load (23%) (p = 0.034) but not the stiffness of the canine infraspinatus tendon repair. At twelve weeks, the poly-L-lactide scaffold was observed to be histologically biocompatible, and augmented repairs demonstrated significantly less tendon retraction (p = 0.008) and significantly greater cross-sectional area (137%), stiffness (26%), and ultimate load (35%) than did repairs that had not been augmented (p < 0.001, p = 0.002, and p = 0.009, respectively).

CONCLUSIONS

While limiting but not eliminating tendon repair retraction, the augmentation device provided a tendon-bone bridge and scaffold for host tissue deposition and ingrowth, resulting in improved biomechanical function of the repair at twelve weeks.

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.

Open versus two forms of arthroscopic rotator cuff repair

There have been technologic advances in the methods for repairing torn rotator cuffs. We compared the clinical and structural outcomes of three different forms of rotator cuff repair with up to 24 months' followup. We wished to assess how surgical technique affected clinical outcomes and see how these correlated to repair integrity. Three cohorts of patients had repair of a symptomatic rotator cuff tear using (1) an open technique (n = 49); (2) arthroscopic knotted (n = 53); or (3) arthroscopic knotless (n = 57) by one surgeon. Standardized patient- and examiner-determined outcomes were obtained preoperatively and at 6 weeks, 3 and 6 months, and 2 years postoperatively. Ultrasound studies were performed with a validated protocol at 6 months and 2 years postsurgery. Clinical outcomes were similar with the exception that the arthroscopic groups had, on average, 20% better American Shoulder and Elbow Surgeons scores than the open group at 6 months and 2 years. Retear correlated with tear size and operation time and occurred more frequently after open repair (39%) than after arthroscopic knotted (25%) and arthroscopic knotless (16%) repair. An intact cuff on ultrasound corresponded to better results for supraspinatus strength, patient outcomes, and rotator cuff functional ability.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Rotator cuff repair fluid extravasation characteristics are influenced by repair technique

BACKGROUND

This study evaluates rotator cuff repair fluid extravasation characteristics for different rotator cuff repair techniques.

METHODS

Eight fresh-frozen cadaveric shoulders were dissected free of soft tissues, with the glenohumeral joint capsule and rotator cuff muscles being left intact. A custom fluid infusion device was used to deliver fluid at constant pressure into the glenohumeral joint. The shoulders were tested in conditions of (1) intact rotator cuff, (2) supraspinatus tear, (3) repaired supraspinatus tear with a single-row technique, and (4) repaired supraspinatus tear with a double-row suture bridge technique.

RESULTS

The volume per minute of saline solution extravasation for single-row repair and double-row suture bridge repair was 48.53 mL/min and 11.73 mL/min, respectively, at 2 psi; 73.3 _ 24.1 mL/min and 24.5 _ 19.7 mL/min, respectively, at 3 psi; and 95.2 _ 22.6 mL/min and 39.2 _ 23.8 mL/min, respectively, at 4 psi. There was a statistically significant greater fluid extravasation for the single-row repair compared with the double-row suture bridge repair at all 3 pressures tested (P < .05).

CONCLUSION

Single-row rotator cuff repair exposes the healing zone to greater extravasation of fluid compared with double-row suture bridge repair. Therefore, double-row repair potentially enhances rotator cuff healing.

LEVEL OF EVIDENCE

Controlled laboratory study.

Prospective analysis of arthroscopic rotator cuff repair: subgroup analysis

BACKGROUND

The rotator cuff registry was established to evaluate prospectively the effectiveness of arthroscopic rotator cuff repair. The purpose of the present study is to report the preliminary data at the 1- and 2-year time point and perform subgroup analysis to identify factors that may affect outcome.

METHODS

A total of 193 patients underwent all-arthroscopic repair of a rotator cuff tear and met the inclusion criteria and 127 (65.8%) completed 2-year follow-up. The outcome measurements included physical examination, manual muscle testing, the American Shoulder and Elbow Surgeons (ASES) score, and ultrasonography.

RESULTS

The pre-operative ASES score was 52.37 +/- 24.09 and improved to 83.88 +/- 19.28 at 1 year (P < .0001) and 92.65 +/- 11.36 at 2 years (P < 0.0001). The percent healing for all patients was 64.10% at 3 months and 64.34% at 1 year (P = .4080). At 2 years, there was a significant increase in the percentage of healed tendon at 75.42% compared to the 3-month (P (1/4) .0001) and 1-year (P = 0.0332) time points. Patients with intact tendons had an ASES score of 93.9 +/- 10.2 compared to tendon defects with a score of 88.0 +/- 15.6 (P = .0623). Gender, tear size, and acromioclavicular joint involvement have a significant effect on ASES score. Rotator cuff characteristics such as tear size, biceps pathology, acromioclavicular joint pathology, and tissue quality have a significant effect on postoperative tendon integrity.

CONCLUSION

Arthroscopic rotator cuff repair demonstrates significant improvement in clinical outcomes and good rate of healing by postoperative ultrasound. Longer-term studies are necessary to determine the efficacy over time.

Frog glue enhances rotator cuff repair in a laboratory cadaveric model

SUMMARY

Rotator cuff tendons are typically reattached to the proximal humerus using transosseous sutures or suture anchors. Their primary mode of failure is at the tendon-bone interface. We investigated the addition of a novel adhesive secreted from a species of Australian frog (Notaden bennetti) to different methods of rotator cuff repair. We hypothesized that the addition of frog glue would increase the strength of the repaired rotator cuff construct. Three techniques were used to repair 42 fresh frozen sheep infraspinatus tendons with a mattress stitch configuration: transosseous sutures; 2 traditional metallic suture anchors with 1 suture per anchor, and 2 knotless metallic anchors with 1 suture per anchor. In each group, 7 shoulders were repaired with the addition of frog glue to the infraspinatus "footprint," whereas 7 were used as control with no adhesive. Failure occurred in all constructs at the tendon-bone-suture interface. Repair with suture anchors was stronger than with sutures through bone (P < .05). Frog glue significantly increased the load to failure, total energy required for failure, and maximum energy at failure in all repair techniques (P < .01). A 2-fold increase occurred in load to failure of the 2 common anchor types (143 +/- 8 and 165 +/- 20 N). The load to failure for the transosseous repair (86 +/- 8 N) increased 1.7-fold. The addition of an adhesive to the tendon-bone-suture interface significantly enhances ultimate load and total energy required to failure in 3 types of rotator cuff repair. The unique properties of this frog glue (strong, flexible and sets in water) may ultimately lead to its use as an adjunct to rotator cuff repair in humans.

LEVEL OF EVIDENCE

Basic science study.

Indications for surgery in clinical outcome studies of rotator cuff repair

Full-thickness tears of the rotator cuff are common, but there is no clear consensus regarding indications for rotator cuff surgery. Because some patients with full-thickness rotator cuff tears who are asymptomatic or symptomatic can be successfully treated nonoperatively, clinical outcome studies of rotator cuff repair should describe the subjects in detail to allow appropriate interpretation of the results. However, we hypothesized the indications for surgery are poorly described in outcome studies of rotator cuff surgery. We undertook a detailed literature review over 11 years of six major orthopaedic journals to assess whether the indications for surgery were described adequately in studies of rotator cuff repair. Eighty-six papers fit the criteria for the study and were reviewed. Limitations of activities of daily living (31%), failure of nonoperative treatment (52%), duration of nonoperative treatment (26%), and history of nocturnal pain (16%) were reported in a minority of papers overall. The patients' characteristics and indications for surgery were not described in a majority of clinical outcome studies of rotator cuff repair. It is important for these factors to be considered and reported because, without this information, the reasons for and results of rotator cuff repair are difficult to interpret.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Single-row versus double-row arthroscopic rotator cuff repair: a prospective randomized clinical study

PURPOSE

The purpose of this study was to compare the clinical outcome of arthroscopic rotator cuff repair with single-row and double-row techniques.

METHODS

Eighty patients with a full-thickness rotator cuff tear underwent arthroscopic repair with suture anchors. They were divided into 2 groups of 40 patients according to repair technique: single row (group 1) or double row (group 2). Results were evaluated by use of the Disabilities of the Arm, Shoulder and Hand (DASH) and Work-DASH self-administered questionnaires, normalized Constant score, and muscle strength measurement. On analyzing the results at a 2-year follow-up, we considered the following independent variables: baseline scores; age; gender; dominance; location, shape, and area of cuff tear; tendon retraction; fatty degeneration; treatment of biceps tendon; and rotator cuff repair technique (anchors or anchors and side to side). Univariate and multivariate statistical analyses were performed to determine which variables were independently associated with the outcome. Significance was set at P < .05.

RESULTS

Of the patients, 8 (10%) were lost to follow-up. Comparison between groups did not show significant differences for each variable considered. Overall, according to the results, the mean DASH scores were 15.4 +/- 15.6 points in group 1 and 12.7 +/- 10.1 points in group 2; the mean Work-DASH scores were 16.0 +/- 22.0 points and 9.6 +/- 13.3 points, respectively; and the mean Constant scores were 100.5 +/- 17.8 points and 104.9 +/- 21.8 points, respectively. Muscle strength was 12.7 +/- 5.7 lb in group 1 and 12.9 +/- 7.0 lb in group 2. Univariate and multivariate analysis showed that only age, gender, and baseline strength significantly and independently influenced the outcome. Differences between groups 1 and 2 were not significant.

CONCLUSIONS

At short-term follow-up, arthroscopic rotator cuff repair with the double-row technique showed no significant difference in clinical outcome compared with single-row repair.

LEVEL OF EVIDENCE

Level I, high-quality randomized controlled trial with no statistically significant differences but narrow confidence intervals.

Comparative evaluation of the tendon-bone interface contact pressure in different single- versus double-row suture anchor repair techniques

The aim of the study was to evaluate the time zero contact pressure over a defined rotator cuff footprint using different repair and stitch techniques in an established sheep model. Forty fresh-frozen sheep shoulders were randomly assigned to five repair groups: single-row repair using simple stitches (SRA-s), single-row repair using horizontal mattress stitches (SRA-m), and single-row repair using arthroscopic Mason-Allen stitches (SRA-ama). Double-row repair was either performed with a combination of simple and horizontal mattress stitches (DRA-sm) or with arthroscopic Mason-Allen/horizontal mattress stitches (DRA-amam). Investigations were performed using a pressure-sensitive film system. The average contact pressure and pressure pattern were measured for each group. Contact pressure was lowest in SRA-m followed by SRA-s. SRA-ama showed highest contact pressure of all single-row treatment groups (P < 0.05). DRA-amam presented the highest overall contact pressure (P < 0.05), whereas DRA-sm exerted contact pressure equal to that of SRA-ama. Both double-row techniques showed the most expanded pressure pattern. Average contact pressures for the more complex single- and double-row techniques utilizing arthroscopic Mason-Allen stitches were greater than were those of the repair techniques utilizing simple and horizontal mattress stitches. However, the contact pattern between the anchors could be increased by using the double-row technique, resulting in more footprint coverage compared to patterns utilizing the single-row techniques. These results support the use of the more complex arthroscopic Mason-Allen stitches and may improve the environment for healing of the repaired rotator cuff tendon.

Prognostic factors affecting anatomic outcome of rotator cuff repair and correlation with functional outcome

PURPOSE

To analyze the relationship between functional outcomes and postoperative cuff integrity (anatomic outcome), and to reveal the factors affecting outcomes of rotator cuff repair.

METHODS

Seventy-eight patients who had undergone repair of full-thickness rotator cuff tear received both computed tomographic arthrography (CTA) and functional evaluation a minimum of 1 year after surgery. The mean follow-up period was 19.6 months (range, 12 to 39 months). Anatomic outcome was evaluated by CTA. Functional outcomes were evaluated by visual analogue scale (VAS) for pain and satisfaction with the operation, Constant score, simple shoulder test (SST), and American Shoulder and Elbow Surgeons (ASES) score. Various clinical and structural factors were included for statistical analysis.

RESULTS

All patients displayed significant improvement in all functional evaluations at the final visit. Functional outcome did not correlate with anatomic outcome (P > .05). A few variables did relate to functional outcome: female or old age statistically correlated with the score of SST, and the size of the tear correlated with the ASES score (P < .05). The retear was influenced by age, fatty degeneration of the cuff muscles, and the size of tear. Fatty degeneration of the infraspinatus was the most independent predictor of anatomic outcome on multivariate regression analysis.

CONCLUSIONS

Rotator cuff repair brought significant functional improvement. However, the functional outcome did not correlate with the anatomic outcome. The fatty degeneration of the infraspinatus muscle served as an independent predictor of the postoperative integrity of the rotator cuff.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Do outcomes differ after rotator cuff repair for patients receiving workers' compensation?

Comparisons of outcomes after rotator cuff repair between Worker's Compensation Board (WCB) recipients and nonrecipients generally do not consider patient, injury, and shoulder characteristics. We compared preoperative differences between WCB recipients and nonrecipients and determined the impact on their 6-month postoperative outcome. We evaluated a prospective cohort of 141 patients with full-thickness rotator cuff tears, 36 of whom (26%) were WCB recipients, preoperatively and 3 and 6 months after rotator cuff repair. Their mean age was 54.0 +/- 10.4 years (standard deviation) and 102 (72%) patients were male. Shoulder range of motion, Western Ontario Rotator Cuff (WORC) index, and American Shoulder and Elbow Surgeons' score were used to evaluate outcomes. We performed regression analyses to control for baseline differences in age, baseline scores, smoking status, symptom duration, injury type, and associated biceps disorder between WCB recipients and nonrecipients. WCB recipients were younger and more likely to smoke, have a traumatic injury, and undergo surgery within 6 months of injury. WCB recipients had lower recovery for all outcomes when these differences were not considered but when differences were accounted for, only 6-month WORC scores were lower in WCB recipients. Clinicians should consider preoperative characteristics before concluding WCB recipients experience less recovery after surgical repair.

LEVEL OF EVIDENCE

Level I, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material

The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P < 0.001). The ultimate tensile strength in double-row specimens was significantly higher than in others (P < 0.001). There was no significant variation in using different suture material (P > 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

Clinical and structural results of partial supraspinatus tears treated by subacromial decompression without repair

Patients with primary impingement and articular sided partial tears of the supraspinatus are often treated by subacromial decompression without repair, if the extent of the tear is estimated to be below 50% of tendon thickness. It has been questioned whether repair of these cuff lesions is necessary, because these tears could progress to full thickness tears with deteriorating clinical results. Our hypothesis was that subacromial decompression without repair of the supraspinatus tendon leads to significant clinical improvement for patients with grade I and II articular sided tears without progression to a full thickness tear on a regular basis. 46 consecutive patients (av. Age 59.2 years, range 33-76.6 years) were retrospectively reviewed after an average follow up of 50.3 months (36-86 months). 26 patients (43.5%) had a grade I tear according to Ellman, which was left alone, 20 patients suffered from a grade II tear, which was debrided. Clinical outcome was assessed with the ASES Score and ultrasound evaluation was performed on all patients to detect possible progression to a full thickness tear. The average ASES Score significantly improved from 37.4 to 86.6 points (p < 0.0001). The mean postoperative Constant Score was 87.6 points. Only three patients (6.5%) progressed to a full thickness tear detectable on ultrasound examination. Only one of these patients had a poor result with an ASES Score of 35 points, the other two were very satisfied and had an ASES score above 90 points. 8 patients showed no more signs of partial tearing on ultrasound and these patients had an average ASES Score of 93.1 points. Overall clinical outcome was rated excellent in 35 cases (76.1%), good in 5 (10.9%), average in 2 (4.3%) and poor in 4 (8.7%). Our results indicate that good and excellent results can be achieved mid- to long term by acromioplasty without repair of the rotator cuff in articular sided partial tears grade I and II. These results reach almost 95% of the value of a healthy shoulder. A better result on ultrasound examination was associated with a superior clinical outcome, while progression to a full thickness tear was rare.

Prospective analysis of arthroscopic rotator cuff repair: prognostic factors affecting clinical and ultrasound outcome

The purpose of this study was to identify potential predictors of function and tendon healing after arthroscopic rotator cuff repair that will enable the orthopaedic surgeon to determine which patients can expect a successful outcome. Between 2003 and 2005, the Arthroscopic Rotator Cuff Registry was established to collect demographic, intraoperative, functional outcome, and ultrasound data prospectively on all patients who underwent primary arthroscopic rotator cuff repair. At total of 193 patients met the study criteria, and 127 (65.8%) completed the 2-year follow-up. The most significant independent factors affecting ultrasound outcome were age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.02-1.14; P = .006) and tear size (OR, 2.29; 95% CI, 1.55-3.38; P < .001). After adjustment for age and tear size, the intraoperative factors found to be significantly associated with a tendon defect were concomitant biceps procedures (OR, 11.39; 95% CI, 2.90-44.69; P < .001) and acromioclavicular joint procedures (OR, 3.85; 95% CI, 1.46-10.12; P = .006). In contrast to the ultrasound data, the functional outcome variables, such as satisfaction (OR, 3.92; 95% CI, 2.00-7.68; P < .001) and strength (OR, 10.05; 95% CI, 1.61-62.77; P = .01), had a greater role in predicting an American Shoulder and Elbow Surgeons score greater than 90. The progression from a single-tendon rotator cuff tear to a multiple-tendon tear with associated pathology increased the likelihood of tendon defect by at least 9 times, and therefore, earlier surgical intervention for isolated, single-tendon rotator cuff tears could optimize the likelihood of ultrasound healing and an excellent functional outcome.

Repair integrity and clinical outcome after arthroscopic rotator cuff repair using single-row anchor fixation: a prospective study of single-tendon and two-tendon tears

This prospective study determined whether single-row anchor fixation would reliably improve clinical outcome and maintain structural integrity after arthroscopic repair of single-tendon and 2-tendon rotator cuff tears. In 39 patients, 21 shoulders had single-tendon tears and 18 had 2-tendon tears. Mean follow-up was 38 months (minimum, 24 months). A standardized assessment was done preoperatively and postoperatively at yearly intervals. Postoperative magnetic resonance imaging (MRI) was performed at a minimum 1-year follow-up. Mean forward elevation, pain, satisfaction, and American Shoulder and Elbow Surgeons scores significantly improved for both groups (P < .01). Postoperative MRI examinations showed 19 cuffs (90%) were intact for single-tendon tears and 15 (83%) were intact for 2-tendon tears. A recurrent tear on postoperative MRI was significantly correlated with the intraoperative finding of asymmetric retraction. Arthroscopic rotator cuff repair using single-row anchor fixation resulted in significant improvements in clinical outcome and reliable repair integrity for both single-tendon and 2-tendon tears.

Single-row modified mason-allen versus double-row arthroscopic rotator cuff repair: a biomechanical and surface area comparison

PURPOSE

The purpose of this study was to compare the time-zero biomechanical strength and the surface area of repair between a single-row modified Mason-Allen rotator cuff repair and a double-row arthroscopic repair.

METHODS

Six matched pairs of sheep infraspinatus tendons were repaired by both techniques. Pressure-sensitive film was used to measure the surface area of repair for each configuration. Specimens were biomechanically tested with cyclic loading from 20 N to 30 N for 20 cycles and were loaded to failure at a rate of 1 mm/s. Failure was defined at 5 mm of gap formation.

RESULTS

Double-row suture anchor fixation restored a mean surface area of 258.23 +/- 69.7 mm(2) versus 148.08 +/- 75.5 mm(2) for single-row fixation, a 74% increase (P = .025). Both repairs had statistically similar time-zero biomechanics. There was no statistical difference in peak-to-peak displacement or elongation during cyclic loading. Single-row fixation showed a higher mean load to failure (110.26 +/- 26.4 N) than double-row fixation (108.93 +/- 21.8 N). This was not statistically significant (P = .932). All specimens failed at the suture-tendon interface.

CONCLUSIONS

Double-row suture anchor fixation restores a greater percentage of the anatomic footprint when compared with a single-row Mason-Allen technique. The time-zero biomechanical strength was not significantly different between the 2 study groups. This study suggests that the 2 factors are independent of each other.

CLINICAL RELEVANCE

Surface area and biomechanical strength of fixation are 2 independent factors in the outcome of rotator cuff repair. Maximizing both factors may increase the likelihood of complete tendon-bone healing and ultimately improve clinical outcomes. For smaller tears, a single-row modified Mason-Allen suture technique may provide sufficient strength, but for large amenable tears, a double row can provide both strength and increased surface area for healing.

Biomechanical comparison of single-row arthroscopic rotator cuff repair technique versus transosseous repair technique

This study determined the effect of tear size on gap formation of single-row simple-suture arthroscopic rotator cuff repair (ARCR) vs transosseous Mason-Allen suture open RCR (ORCR) in 13 pairs of human cadaveric shoulders. A massive tear was created in 6 pairs and a large tear in 7. Repairs were cyclically tested in low-load and high-load conditions, with no significant difference in gap formation. Under low-load, gapping was greater in massive tears. Under high-load, there was a trend toward increased gap with ARCR for large tears. All repairs of massive tears failed in high-load. Gapping was greater posteriorly in massive tears for both techniques. Gap formation of a modeled RCR depends upon the tear size. ARCR of larger tears may have higher failure rates than ORCR, and the posterior aspect appears to be the site of maximum gapping. Specific attention should be directed toward maximizing initial fixation of larger rotator cuff tears, especially at the posterior aspect.

Arthroscopic debridement of massive irreparable rotator cuff tears

PURPOSE

The purpose of this study was to evaluate clinical and radiologic results of arthroscopic debridement of massive irreparable rotator cuff tears.

METHODS

Thirty-one patients (mean age, 70.6 years) were retrospectively reviewed for a mean of 47 months (range, 24 to 69 months) after arthroscopic debridement of an irreparable rotator cuff tear. Operative treatment included biceps tenotomy in 24 cases (77.4%). No acromioplasty was performed to maintain the coracoacromial arch. Clinical outcome was assessed by use of the American Shoulder and Elbow Surgeons (ASES) and Constant scores, as well as measurement of abduction strength and elbow flexion strength compared with the contralateral side at final follow-up. Preoperative and follow-up radiographs were evaluated for acromiohumeral distance and grade of osteoarthritis according to the Samilson-Prieto classification.

RESULTS

The mean ASES score was significantly improved from 24.0 to 69.8 points at follow-up. Scores for pain were reduced from 7.8 to 2.9 points on a visual analog scale ranging from 0 to 10 points. The age- and gender-adjusted Constant score was 72.2%. Radiologic analysis showed progression of osteoarthritis in 10 cases (32.3%); this had no influence on the ASES score. Acromiohumeral distance decreased from 8.3 to 7.0 mm. Biceps strength was 6.1 kg on the operated side and 6.3 kg on the contralateral side. Abduction strength was significantly lower on the operated side at 2.6 kg versus 3.7 kg on the contralateral side. No complication related to the procedure was reported.

CONCLUSIONS

For elderly patients with low functional demands, arthroscopic debridement in combination with biceps tenotomy is a safe procedure and leads to significant functional improvement without loss of biceps strength. Progression of osteoarthritic changes cannot be prevented, but no influence on the clinical result could be shown.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Heat shock protein and apoptosis in supraspinatus tendinopathy

Heat shock proteins (HSPs) are often upregulated following oxidative and other forms of stress. Based on reports of excessive apoptosis in torn supraspinatus tendon and mechanically loaded tendon cells, we hypothesized heat shock proteins may be present in rodent and human models of tendinopathy due to their central role in caspase dependent apoptotic cell signaling. We used a running rat supraspinatus tendinopathy overuse model with custom microarrays to investigate the process at a genetic level. Additionally torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from 10 patients undergoing arthroscopic stabilization surgery and evaluated using semiquantative RT-PCR and immunohistochemistry. We identified substantial upregulation of heat shock proteins and apoptotic genes in the rodent model. We further confirmed increased levels of heat shock protein and apoptotic regulatory genes in human supraspinatus and subscapularis tendon. This finding suggests heat shock proteins play a role in the cascade of stress-activated programmed cell death and degeneration in tendinopathy and may provide a novel target in preventing tendinopathies.

Loss of rotator cuff tendon-to-bone interface pressure after reattachment using a suture anchor

The purpose of this study was to examine the tendon-to-bone interface pressure, contact area, and force after reattaching a tendon to bone by use of a suture and suture anchor. Repairs were made in 8 ovine shoulders in vitro, by use of 3 suture types in each: Ethibond, polydioxanone, or Orthocord. A Tekscan pressure sensor was placed between the tendon and bone and monitored for 1 hour after the repair. The principal finding was a significant loss of approximately 60% of the contact parameters immediately after the suture was tied, followed by further significant loss over the next hour to a mean of only 14% of the initial readings. We concluded that pressure measurement systems that only record the initial maximum pressure would yield overly optimistic results for the actual repair pressure after the repair is completed. The Tekscan system, however, allowed us to monitor pressure reductions that occurred both during and after the repair.

Biomechanical evaluation of rotator cuff repairs in a sheep model: suture anchors using arthroscopic Mason-Allen stitches compared with transosseous sutures using traditional modified Mason-Allen stitches

BACKGROUND

The optimal method for rotator cuff repair of the shoulder is not yet known. The aim of this study was to compare the time-dependent biomechanical properties of the traditional open transosseous suture technique and modified Mason-Allen stitches (group 1) versus the double-loaded suture anchors technique and so-called arthroscopic Mason-Allen stitches (group 2) in rotator cuff repair.

METHODS

Eighteen adult female sheep were randomized into two groups: in an open approach in which the released infraspinatus tendon was repaired with group 1, and with group 2. Animals were sacrificed at 6, 12, or 26 weeks; shoulders were harvested and magnetic resonance imaging was performed. Eight untreated contralateral shoulders served as controls. Tendons of 16 additional unpaired cadaver shoulder joints of adult female sheep were identically treated for analysis at time zero. In a biomechanical evaluation all specimens were loaded to failure at a constant displacement rate using a standard universal testing machine. The load-to-failure and stiffness of the healed bone-tendon interface were calculated.

RESULTS

Magnetic resonance imaging analysis showed cuff integrity in all cases, and no evidence of foreign body reaction to the anchors. Load-to-failure and stiffness data did not indicate any significant difference between the two treatment groups, neither at 6 weeks nor at 12 or 26 weeks. However, at time zero the group 2 had a higher load-to-failure in comparison to the group 1 (P<0.010), but there was no difference for the stiffness (P<0.121).

CONCLUSIONS

This in vivo study showed that, postoperatively, the group 2 technique provides superior stability and after healing would gain strength comparable to the group 1 technique.

Biological augmentation of rotator cuff tendon repair

A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due to abnormal or insufficient gene expression and/or cell differentiation at the repair site. Techniques to manipulate the biologic events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive growth factors and BMP-12 on tendon-to-bone healing. Magnetic resonance imaging and histology showed increased formation of new bone and fibrocartilage at the healing tendon attachment site in the treated animals, and biomechanical testing showed improved load-to-failure. Other techniques with potential to augment repair site biology include use of platelets isolated from autologous blood to deliver growth factors to a tendon repair site. Modalities that improve local vascularity, such as pulsed ultrasound, have the potential to augment rotator cuff healing. Important information about the biology of tendon healing can also be gained from studies of substances that inhibit healing, such as nicotine and antiinflammatory medications. Future approaches may include the use of stem cells and transcription factors to induce formation of the native tendon-bone insertion site after rotator cuff repair surgery.