Introduction

A couple of weeks ago, we reviewed a study by Longo et al. on the effectiveness of conservative or surgical management of rotator cuff tears. Repair of the torn rotator cuff tendon is often advocated to restore normal tendon integrity and to achieve full functionality of the shoulder. However, depending on the resource, rotator cuff retear rates may be high, ranging from 11%-94%. Thus, it is unclear whether rotator cuff suturing contributes to functional recovery given these high retear rates. This study undertook a systematic review and meta-analysis to define the incidence of rotator cuff retear rates after surgical treatment at different time points and to identify the main factors influencing the postoperative rotator cuff healing.

Methods

In this systematic review and meta-analysis only level 1 and 2 clinical studies were included. The individual studies enrolled patients with full-thickness rotator cuff tears who underwent surgical repair. Postoperative rehabilitation protocols concerning the immobilization period, passive and active range of motion and strengthening exercises had to be reported. The rotator cuff retear rates, confirmed by postoperative diagnostic imaging, had to be documented as an outcome measure. Only types 4 and 5 of the Sugaya classification were considered as full-thickness rotator cuff tears.

Different subgroups were created to tackle the problem of heterogeneity and the rotator cuff retear rates were calculated as the number of patients with a not healed tendon after surgery to the total number of patients undergoing rotator cuff surgery. The reported odds ratios indicate the probability that a rotator cuff retear occurred after surgery to the probability that it did not occur.

Results

In total 59 studies matched the inclusion criteria and of them, 31 studies were included into the quantitative synthesis since they were of high-quality. The diagnostic imaging follow-up ranged between 1 month and 60 months and revealed that the percentage of rotator cuff retear rates was 15% at 3 months, 21% at 3-6 months, 16% at 6-12 months, 21% at 12-24 months and 16% at follow-up longer than 2 years.

Rotator cuff retear rates and patient-related risk factors

Rotator cuff retear rates were higher when patients were older than 60 years of age. Below 60 years 14.4% showed retears while this was 24.3% in patients older than 60 years. (OR=1.8 (1.5-2.3)).

Patients undergoing surgery for small to medium sized rotator cuff tears had less risk of retears than those with large to massive tears. In the small to medium tears group, 12.5% versus 37% in the large to massive tears group were seen. However, this led to a relatively small but significant odds ratio of 0.3 (0.2-0.5).

In those cases with fatty infiltration, no differences in rotator cuff retear rates compared to those without fatty infiltration was seen. (OR=0.9 (0.4-1.9)). 

Rotator cuff retear rates and postoperative rehabilitation protocol 

The rotator cuff retear rates between those who wore a sling for up to 6 weeks compared to those who were immobilized in a sling for more than 6 weeks revealed no significant differences. OR=1.4 (0.1-1.2)).

Equally when looking at the initiation of passive range of motion exercises, no differences in retears were seen between those who performed early passive (within 7 days post surgery) versus those who performed delayed passive ROM exercises (>7 days) (OR=0.8 (0.7-1.1)). 

Looking at active-assisted ROM revealed that patients who initiated active-assisted ROM before 5 weeks were at higher risk of rotator cuff retears than those who delayed active-assisted ROM. (OR=0.5 (0.4-0.7)). 

Examining full active range of motion exercises before and after 8 weeks revealed that a delay of the initiation beyond 8 weeks was associated with an increased risk of retears (OR=2 (1.3-3.2)). 

The initiation of strengthening exercises before and after 12 weeks was not associated with differences in rotator cuff retear rates. (OR=1.1 (0.8-1.5)). 

Rotator cuff retear rates and surgical techniques

No differences in retears were found between those who underwent arthroscopic versus open/mini-open surgery (OR=1.0 (0.7-1.7)). 

The same was true for when single-row repair was compared to double-row repair (OR=1.3 (0.9-1.9)). 

Single-row repair compared to suture bridge/transosseous repair was compared and revealed that the latter corresponded to a higher retear rate (OR=0.6 (0.4-0.8)). Similarly, this technique was also associated with an increased rotator cuff retear rate when compared to double-row repair (OR=0.5 (0.3-0.7)). 

The injection of platelet-rich plasma (PRP) was associated with a lower retear rate than when PRP was not injected (OR=0.6 (0.4-0.9)). Tendon augmentation also corresponds to a lower retear rate (OR=0.2 (0.1-0.4)). 

Questions and thoughts

This systematic review sheds light on risk factors for rotator cuff retears. Patient-related factors, rehabilitation-related factors, and surgical procedures were examined, and this information can be used to determine the individual patient risk. Subgrouping of risk factors was based upon the rehabilitation protocol of the Multicenter Orthopaedic Outcomes Network Shoulder group (the MOON Shoulder Group). 

The exclusion of moderate and low quality articles may be questioned but leads to conclusions based upon high quality research. By excluding those articles from the meta-analyses the risk factors for rotator cuff retears determined here were based upon high quality and the evidence should not be downgraded. Another strategy could have been to include these studies, but then the risk of inaccuracy, heterogeneity, and publication bias would result in the evidence being downgraded, leaving conclusions based on flawed evidence, and by extension, would not allow for a clear answer to the research question.

Talk nerdy to me

The systematic review was well conducted, according to the PRISMA guidelines and with a thorough search for evidence. Despite this, only English articles were included, which may introduce language bias into the conclusions. 

The inclusion of only level 1 and 2 studies and the inclusion of full-thickness rotator cuff tears into this review promotes homogeneity into the findings. The MOON Group rehabilitation protocol was consulted to stratify the analyses, so the conservative rehabilitation was based on existing and realistic timeframes.

Take home messages

Age, size of rotator cuff tear, starting early active-assisted ROM (within 5 weeks after surgery), delaying full active ROM (beyond 8 weeks) were associated with increased rotator cuff retear rates. Fatty infiltration, immobilization period, the early initiation of passive ROM (within 1 week after surgery), the initiation of strengthening exercises before or after 12 weeks were not associated with an increased incidence of rotator cuff retears

Although we as physiotherapists have no voice in choosing surgical techniques, we should be aware of what repair technique has been used when we start rehabilitation in a patient who had rotator cuff repair. This meta-analysis found an increased rotator cuff retear rate after suture bridge/transosseous repair and a lower risk after the use of PRP and tendon augmentation. No differences in the retear risk between arthroscopy and (mini)open surgery and between single-row versus double-row repair were seen. 

Reference

Longo UG, Carnevale A, Piergentili I, Berton A, Candela V, Schena E, Denaro V. Retear rates after rotator cuff surgery: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2021 Aug 31;22(1):749. doi: 10.1186/s12891-021-04634-6. PMID: 34465332; PMCID: PMC8408924. https://pubmed.ncbi.nlm.nih.gov/34465332/