Structural integrity of rotator cuff at 16 years following repair: good long-term outcomes despite recurrent tears (2024)

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Abstract

Keywords: cuff integrity, long-term follow-up, mini-open cuff repair, patient-reported outcome measures, rotator cuff repair

Introduction

Rotator cuff tears of the supraspinatus are a common shoulder condition affectingmiddle to older age adults. The aetiology can be traumatic, degenerative or acombination. Presentation is variable with many full-thickness tears beingasymptomatic, whereas others cause pain and weakness.¹ A significant proportion of tears are known to progress in size and largertears are more likely to cause pain and weakness.² Rotator cuff arthropathy is the final consequence of massive rotator cufftear and causes stiffness, pain and weakness.

Rotator cuff repair aims to restore cuff integrity, stop pain and preserve power andmotion. With increasing evidence suggesting that the condition is degenerative, witha genetic predisposition, it is imperative to investigate whether we are able toalter the natural history of this condition by reattaching the tendons tobone.^3–6

The purpose of the present study was to assess the structural integrity of therotator cuff at long-term follow-up following superior cuff repair. The secondaryobjective was to assess clinical outcomes in relation to cuff integrity and identifypossible factors associated with poor structural or clinical outcome.

Materials and methods

Medical Ethics Committee approval was obtained and all study participants providedtheir informed consent. Patients were initially enrolled by the senior surgeon (SNB)over a 4-year period. We have previously reported on the clinical outcomes atmedium- and long-term follow-up from this series.^7,8 Patients presented with pain andweakness of the affected shoulder, with clinical findings suggesting rotator cuffpathology and impingement.

Inclusion criteria were the presence of a reparable supraspinatus, or supraspinatusand infraspinatus, tendon tear. Patients were excluded in the presence ofglenohumeral or acromioclavicular osteoarthritis, biceps degeneration requiringtenodesis or a massive cuff tear (greater than 5 cm).

The presence of a reparable supraspinatus tear was demonstrated on ultrasound in allcases and subsequently confirmed intra-operatively. Tear size was measuredintra-operatively in the sagittal plane at the greater tuberosity and classified assmall (<1 cm), medium (1 cm to 3 cm), large (3 cm to 5 cm and involving two ormore tendons). Massive (>5 cm and involving two or more tendons) tears were excluded.⁹ All operations were performed by the senior surgeon (SNB).

The patient was placed in a lateral position with the arm in traction. Anarthroscopic acromioplasty was performed, including bursectomy. Subsequently, therotator cuff was approached via a small longitudinal mini-open split in the deltoidmuscle attachment to the acromion, taking care not to detach any deltoid muscle fromthe acromion. The greater tuberosity bone was freshened and a rotator cuff-to-bonerepair was performed with use of transosseous Ethibond number-1 suture (Ethicon,Somerville, NJ, USA). The suture was passed through the cuff tendon medially, andthen through the tuberosity bone at the articular margin to emerge lateral to thetuberosity. In general, two separate passes through the bone and tendon were carriedout for each individual ethibond suture. PDS (polydioxanone) number-1 suture(Ethicon) was used for side-to-side tendon repair and was placed to diminish stresson the tendon-to-bone sutures. No transosseous sutures through the lateral cuffmargin or Mason-Allen suture techniques were utilized.

Postoperative rehabilitation was routinely commenced on the first postoperative day.This consisted of pendular exercises with supine passive self-assisted externalrotation and forward elevation. A sling was worn for 3 weeks.

Seventy-nine consecutive patients were initially recruited for follow-up. At the7-year report, this was reduced to 74 as a result of three deaths and two patientsloss to follow-up. By 2010, the number of willing and able participants had droppedto 49. Of those that could not participate with respect to questionnaire completion:11 had died, three had dementia and 16 were completely lost to follow-up. Patientswere asked to complete a subjective self-scoring University of California LosAngeles (UCLA) questionnaire. This included visual analogue pain scores at rest andon activity and patient satisfaction with surgery. The outcome results arecategorically reported as excellent (34 points to 35 points), good (28 points to33 points), fair (21 points to 27 points) or poor (< 20 points).¹⁰

American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test (SST) measureswere also self-assessed. All tests have been validated forself-assessment.^11–13

Patients were invited after their last clinical follow-up to undergo diagnosticultrasound scan (USS) at a University affiliated radiology practice where scans weredual reported by two out of three experienced musculoskeletal radiologists. Adedicated study report sheet was completed assessing the integrity of the cufftendons, long head of biceps, bursal tissue and the presence of fluid about thebursa, joint and long head of biceps. Tears of the cuff were measured in thesagittal plane and classified according to thickness and tendons involved.Twenty-seven shoulders underwent ultrasound in 25 patients (two bilateral). Of the49 patients who were located and completed the self-assessment at this time; 24 didnot undergo USS. The reasons for not attending the USS included inconvenience orother obligations such as work or care giving (n = 6), immobilityand frailty (n = 3), unacceptable distance to imaging centre(n = 5), did not want to participate (n = 2)and no reason given/loss to follow-up (n = 8) (Figure 1).

Results

Full-thickness re-tears (or failure to heal) of the surgically repaired supraspinatuswere noted in 10 shoulders. Nine full-thickness tears were noted at USS and theother was noted during revision surgery. The incidence of full-thickness recurrenttear was 37%. Overall, five re-tears were small, three re-tears were medium and twowere large in size. Only one tear increased in size, from medium to large; theremainder were the same size or smaller.

Two patients required revision repair of the supraspinatus tendon. One patientrequired revision repair 16 months after the primary surgery. The revision surgery,which was for acromioclavicular pain, identified failure of healing in the midportion (< 1 cm, small) of supraspinatus and an identical repair technique wasused again, in addition to arthroscopic resection of the distal clavicle. Thispatient was noted to have an intact cuff on USS at 14 years after revision repair.For the purpose of the present study, this patient was assessed as being a re-tear,despite the cuff being intact on USS, as a result of the need for revision surgery.The other patient underwent revision repair in 2010 by another surgeon (15 yearsafter the initial repair); subsequent USS reported a recurrent 30-mm tear in thesupraspinatus, 10 months after revision (see Supporting information, Table S1).

The mean UCLA score was 30. Excellent or Good outcomes were achieved in 74% and fairoutcomes were achieved in 7%, whereas 18% had a poor UCLA score. The mean ASES scorewas 91.3, the mean SST score was 9.5 and 85% of the patients were satisfied withtheir surgery.

Comparing those with a recurrent tear with those whose supraspinatus was intact, itwas noted that the mean age at surgery was higher in those with re-tear, (57.1versus 50.6, p = 0.12), although this did not reach statisticalsignificance. There was no relationship between re-tear and male and female sex(p = 0.69), arm dominance (p = 1.0) and manualworkers (p = 0.23). Initial tear size was not a predictor ofsubsequent re-tear (p = 0.81). Only one patient in the groupreported smoking at the time of surgery, and there were two patients who haddiabetes. These numbers are too small to warrant formal analysis. Of note, bothdiabetics had intact tendons and the smoker had a partial thickness supraspinatustear.

Those with recurrent tears had a mean UCLA score of 31.7 with nine of 10 patientscategorized as good or excellent. The mean UCLA for those without full-thicknessrecurrent tear was 29.0 (p = 0.52). The mean ASES in the re-teargroup was 95.8 compared to those without full-thickness tear with a mean ASES of88.7 (p = 0.48). The SST scores were also similar(p = 0.73) (Table 2).

Satisfaction was 90% for those with a recurrent tear compared to 82% in those withoutrecurrent tear (p = 1.0).

There was no association between bursal thickening and recurrent tear(p = 0.23). There was no association between bursal thickening,subscapularis tendinopathy, long head of biceps presence/absence or supraspinatustendinopathy and the clinical outcome scores (Table 3).

No workers’ compensation patient had a re-tear (p = 0.06), resultingin 35% of those without recurrent tear being workers’ compensation patients. Themean UCLA for workers’ compensation patients was 31.3 (p = 0.64)and ASES was 97.5 (p = 0.25).

The mean age, UCLA, ASES and SST scores between the USS participants and totalrespondents were very similar, as was patient satisfaction and the re-operationrate.

Logistic regression analysis with re-tear as the outcome was performed. Nostatistically significant association of variables was noted. A logistic regressionmodel was fitted for age and re-tears with a p-value of 0.12 forthe co-efficient of age, which resulted in estimates for the probability of re-tearfor patients of different ages (Figure 2).

Discussion

We consider that this series in the present study represents the longest publishedfollow-up on structural integrity following a common, contemporary, rotator cuffrepair technique.

Only one published series has a longer radiographic follow-up of repair integrity.That study had a magnetic resonance imaging (MRI) follow-up to mean 20 years aftersurgery. Its relevance is diminished as a result of the fully open techniqueutilized with open acromioplasty and the high rate of free tendon graft (78%). A 94%re-tear rate was reported.¹⁴ We found a 37% re-tear rate of supraspinatus at 16.25 years following surgerybased on imaging studies and a 7% re-operation rate. The re-tears in almost halfwere only small and probably not important. Therefore, only 19% had a medium orlarge size retear.

These imaging results are comparable to other previously reported series using moderntechniques. Kluger etal.¹⁵ reported a 33% re-tear rate at 11 years after mini-open cuff repair, with an8.6% re-operation rate. Their technique was similar with transosseous ethibondsutures, although they utilized a lateral row transosseous repair, which the seniorauthor (SNB) now also utilizes. They also used an abduction pillow for 6 weekspostoperatively, whereas the present study used a normal sling for 3 weeks only.

Castagna etal.¹⁶ reported a 38% re-tear rate at 30 months following arthroscopic repair. Theirmean UCLA score was also very similar at 30.8.¹⁶ Oh¹⁷ reported a 31.1% re-tear rate at 29 months and Defranco etal.¹⁸ showed a 40% re-tear rate. A recent meta-analysis cited a mean re-tear rateof 26.6% at a mean of 23 months with a range from 6 months to 118.8 months.¹⁹ The present study reports a mean follow-up of 195 months.

Advancing age has consistently been shown to be an independent predictor of failureof cuff repair integrity.^19–22 Those patients with an intactrepair were a mean of 6.5 years younger at surgery, although this failed to reachstatistical significance.

A recent study with sequential imaging over the first year of recovery has suggestedthat the majority of repair failures occur between 6 weeks and 26 weeks aftersurgery. Their overall re-tear rate was 17% at 1 year with only one of 19 tearsoccurring from 26 weeks to 52 weeks.²³ This is supported by Kluger etal.¹⁵ whose follow-up extended to 11 years. Zumstein²⁴ demonstrated an increase in failure rate from 37% at 3.1 years to 57% at9.9 years following open repair of massive cuff tears.

We have an understanding of the natural history of the rotator cuff. The tearing iscommonly degenerative in nature and its prevalence increases and approaches 46% ofthe population at 70 years of age.²⁵ Small tears can, but do not always progress, and symptomatic tears are morelikely to be to progress and be large.² What has not been established is whether rotator cuff repair can alter thenatural history of cuff integrity. It is clear from the present study that cuffrepair and decompression improves pain and outcome scores in most patients from theshort- to long-term in an enduring fashion. This outcome appears to be independentof the integrity of the cuff providing that re-tears are small to medium. Otherstudies have demonstrated a persisting positive outcome after cuff repair despitestructural failure of the cuff repair.^{17,23,26–30}

It is hoped that repairing the tendon may alter the biological environment and allowhealing of the degenerative tendon. In this long-term follow-up, the failure rate(37%) approaches the population incidence at that age; however, 63% were stillhealed at average of 16.25 years postoperatively. The recurrent tears werepredominantly the same size, or smaller. Only one tear, in an elderly gentleman, hadenlarged over baseline and no patients had progressed to cuff arthropathy. Our studypopulation selects those prone to cuff degeneration and so we remain optimistic thatthis surgery does positively alter the natural progression of rotator cuffdegeneration for the majority of our patients.

There are several limitations to the present study. The large loss to follow-up (48%)was disappointing. Although this clearly represents a potential source of responderbias, the comparison of demographics confirms that the USS participants hadcharacteristics similar to the total population sample. The mean age, UCLA, ASES andSST scores between the USS participants and total respondents were very similar, aswas patient satisfaction and the re-operation rate.

The small sample size makes correlation of variables with outcomes subject to betaerror. The rate of reported smoking was very low, as was the incidence of diabetes.Workers’ compensation patients and manual workers did not have inferior structuralor clinical outcomes, although numbers were too low to draw any conclusion. Wereport individual patient demographics so that they may be incorporated into asubsequent meta-analysis.

Initial tear size was graded intra-operatively but sized by ultrasound on follow-upby three experienced musculoskeletal radiologists and the studies were dual read.USS has been shown to be equivalent to MRI when used in the hands of experiencedoperators. The results were also found to correlate well, although not perfectly,with arthroscopic findings.³¹

Plain radiographs were not taken at follow-up to assess for any arthriticdegenerative change that may have contributed to diminished shoulder function. Ashoulder effusion was only noted in two of the patients and both of them hadexcellent outcome scores. Long head of biceps, subscapularis and bursal ultrasoundfindings were not associated with outcome scores.

Conclusions

Arthroscopic acromioplasty with mini-open supraspinatus cuff repair demonstrates a37% rate of recurrent supraspinatus tear at 16-year follow-up, with 19% medium tolarge tears. Clinical outcome scores and satisfaction with surgery remained high andwere not influenced by cuff integrity or other ultrasound findings in the shoulder.Further long-term monitoring and reporting is needed to document the effects ofrotator cuff surgery.

Supplementary Material

Acknowledgements

This paper has been presented previously by the senior author at the 2017 BESS ASM.We would also like to acknowledge Dr K Sharpe, Statistical Consulting Centre, Schoolof Mathematics and Statistics, University of Melbourne, for his assistance with thepaper.

Declaration of Conflicting Interests

The author(s) declared the following potential conflicts of interest with respect tothe research, authorship, and/or publication of this article: None of the authorsreceived payments or services, either directly or indirectly (i.e. via his or herinstitution), from a third party in support of any aspect of this work. None of theauthors, or their institution(s), have had any financial relationship, in the36 months prior to submission of this work, with any entity in the biomedical arenathat could be perceived to influence or have the potential to influence what iswritten in this work. Also, no author has had any other relationships, or hasengaged in any other activities, that could be perceived to influence or have thepotential to influence what is written in this work.

Funding

The author(s) received no financial support for the research, authorship, and/orpublication of this article.

Ethical review and patient consent

Human Research Ethics Committee, Southern Health, VIC, Australia, issued acertificate of approval (10180B). All patients consented to the anonymous use oftheir personal information at initial recruitment, and prior to participation inthis study.

Level of evidence

Level IV: therapeutic

Supplementary Material

Supplementary material is availabe atjournals.sagepub.com/doi/suppl/10.1177/1758573217738198.

References