Rotator Cuff Repair

Scott A. Rodeo, MD, FAAOS

Janice Havasy, BS, MD

Claire D. Eliasberg, MD

Camila B. Carballo, PhD, PT

Dr. Rodeo or an immediate family member serves as a paid consultant to or is an employee of Teladoc and has stock or stock options held in Ortho RTI. Neither of the following authors nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter: Dr. Havasy, Dr. Eliasberg, and Dr. Carballo.

INTRODUCTION

Rotator cuff disease comprises a spectrum of disorders ranging from impingement syndrome to tendinopathy to full-thickness rotator cuff tears. The pathophysiology of rotator cuff disease is complex and likely involves a mix of extrinsic factors, such as the presence of a subacromial bone spur or a hypertrophic coracoacromial ligament, as well as intrinsic factors including vascular compromise, age-related degeneration, and repetitive microtrauma. Although nonsurgical treatment may be the first-line approach for the management of rotator cuff disease, patients in whom nonsurgical treatment has failed may require surgical intervention for rotator cuff repair (RCR). Despite advances in surgical techniques, implants, and fixation constructs, incomplete or failed healing following RCR remains a clinically challenging problem. As a result, orthobiologics have become a topic of increasing scientific and clinical interest with regard to RCR.

PLATELET-RICH PLASMA

Platelet-rich plasma (PRP) has been studied as a possible treatment modality in many different orthopaedic pathologies, including both bone and soft tissues. PRP is a collection of autologous blood that has a high concentration of platelets. Although various classification systems have been proposed to describe PRP prepared by different processing techniques, most commonly, PRP can be described as leukocyte rich or leukocyte poor.¹ The rationale for use of PRP is due to the high concentrations of growth factors such as platelet-derived growth factor (PDGF), transforming growth factor beta 1 (TGF-β1), insulinlike growth factor 1, epidermal growth factor, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor.² PRP has also been noted to activate fibroblasts and collagen remodeling, two processes that are relevant to tendon healing and RCR.³ The clinical use of PRP in rotator cuff tendinopathy has been studied in both the nonsurgical and surgical management of rotator cuff tears of all sizes; however, these data are inconclusive on the efficacy of PRP in decreasing the failure rate and biomechanical strength of the repaired tendon.

Current data suggest that PRP lacks efficacy as a nonsurgical management of rotator cuff disease. Kesikburun et al⁴ studied PRP in patients with chronic tendinopathy and found no difference between PRP and control patients in improvement of quality of life, pain, disability, or shoulder range of motion at 1-year follow-up. Similarly, Schwitzguebel et al⁵ demonstrated no difference in tendon healing or clinical scores, when compared with placebo groups. Additionally, this study observed a significantly higher rate of adverse events (pain lasting longer than 48 hours, frozen shoulder, extension of lesion to bursal or articular surface) in the PRP group (54%) compared with control patients (26%).⁵ A systematic review by Hurley et al⁶ includes five randomized controlled trials, totaling 108 patients treated with PRP and 106 control patients and found no significant effect of PRP in the nonsurgical management of rotator cuff disease. However, because of the variability in different PRP formulations and the lack of a large clinical trial to improve external validity in these studies, further rigorous study is required to reach a definitive conclusion on the effectiveness of PRP.

Arthroscopic repair of torn rotator cuffs is a common surgical procedure performed to decrease pain and improve shoulder function. However, contemporary studies demonstrate that incomplete or failed healing occurs in approximately 15% to 20% of patients and can be affected by surgical repair technique and tear characteristics including tear size, degree of retraction, chronicity, and muscle atrophy.⁷,⁸ Although the data are mixed, there are some early data to support the role of PRP in augmentation of rotator cuff tendon healing for small to medium tear sizes. Zhao et al⁹ demonstrated through a meta-analysis involving 742 patients that leukocyte-poor PRP preparations can decrease the retear rates in any sized tear at medium-term and long-term time points. For medium to large rotator cuff tears, augmentation of arthroscopic RCR with leukocyte-poor PRP did correlate to a decrease in retear rate (3.0% in PRP group versus 20.0% of control group, P = 0.032) and a significant
increase in the cross-sectional area of the supraspinatus muscle in the PRP group when compared with control group.¹⁰ In contrast, Castricini et al were not able to show any benefits, with similar results reported by Malavolta et al in 2018.¹¹,¹² Additionally, repeated PRP injections after RCR do not seem to have any effect on early tendon-bone healing.¹³

Three meta-analyses have conflicting recommendations regarding the use of PRP in RCR, but all cite heterogeneity of the studies as a potential problem and suggest that larger, multicenter studies are required to be able to draw conclusions about the efficacy of this treatment.¹⁴,¹⁵,¹⁶ A principal limitation of PRP studies is the tremendous heterogeneity in different proprietary processes for PRP preparation. Currently used processing techniques produce PRP with widely differing concentration of platelets, ranging from 3 to 15 times higher than normal whole blood, but also differing levels of leukocytes, which potentially may change the inflammatory milieu in the treated tissue after injection.¹⁷ Unfortunately, many studies on PRP use for arthroscopic RCR lack statistical power and have important sources of bias and heterogeneity, so results should be interpreted with caution and should not yet determine clinical practice. It is clear that further studies in the area need to rigorously characterize the biologic activity and composition of PRP to allow identification of the optimal PRP formulation(s) for augmentation of rotator cuff tendon healing.

PATCHES, GRAFTS, AND SCAFFOLDS

Patches and grafts are often used in an effort to augment RCR by supplying additional extracellular matrix as a structural scaffold for healing. Synthetic, allogeneic, and xenogeneic materials have been used. A summary of clinical evidence for the use of grafts for rotator cuff repair¹⁸,¹⁹,²⁰,²¹,²²,²³,²⁴,²⁵,²⁶,²⁷,²⁸,²⁹ is presented in Table 1. Bryant et al¹⁸ used porcine small intestine submucosa as a graft extending over the repaired tendon and reported no statistically significant differences between the graft and no-graft arms of the study in regard to failure rate, Western Ontario Rotator Cuff Index, or postoperative narcotic use. Lederman et al¹⁹ demonstrated an improvement in patient-reported outcomes in patients treated with RCR augmented with porcine dermal matrix; however, there was no control group used in this study. The authors reported a retear rate of 43.9%, which they described as being lower than historical controls.¹⁹ Nicholson et al²¹ found that failure loads were similar between porcine small intestine submucosa, porcine dermal patch, and normal repair of an infraspinatus tear in an ovine model. Xenografts, such as porcine tissues, have fallen out of favor because of high complication rates secondary to severe inflammatory responses, which may be due to the presence of foreign DNA.³⁰,³¹

There has been some success with the use of dermal allografts for RCR augmentation. These materials are also a popular choice for superior capsular reconstruction in the setting of a massive, irreparable rotator cuff tear. Some studies have found functional improvements when dermal allografts are used.³² One example of a commercially available acellular dermal matrix is GRAFTJACKET (Wright Medical Group N.V.).³² Wong et al²² augmented the repair of massive rotator cuff tears in 45 patients with GRAFTJACKET and found that after 2 years of follow-up, these patients improved with few adverse events. Barber et al²³ demonstrated improved American Shoulder and Elbow Surgeons scores and Constant scores, along with a decreased retear rate in patients treated with GRAFTJACKET-augmented RCR compared with RCR alone in a sample of 22 patients. A follow-up study conducted by Johnson et al²⁴ on 14 shoulders demonstrated that 13 of the 14 repaired tendons were intact by 35 months after surgery.

As noted previously, there has been concern over immunogenicity because of residual DNA content from xenografts, and the same concern exists for allografts as well. Many of the commercially available xenografts contain nonnegligible amounts of DNA, even if it is claimed to be acellularized.³³ In addition, it has been established that these grafts and scaffolds have significantly inferior biomechanical properties compared with the native rotator cuff tendon.³³ It also has been shown that there are differences in the graft structure that may affect the ability of progenitor cells to adhere to and proliferate within the graft.³⁴ More high-quality data are required to draw conclusions regarding whether augmentation of RCR with biologic grafts and patches can lead to superior shoulder function and decreased retear rates compared with RCR alone, without an increased immunologically mediated inflammatory response.

Synthetic grafts are made from polypropylene, polycarbonate polyurethane, and poly-l-lactic acid and are usually biomechanically superior to biologic grafts and carry a lower risk of generating an immunogenic reaction.³⁵ Polycarbonate polyurethane does not demonstrate any inflammatory reaction while supporting tissue ingrowth; however, tissue integration does not replicate native collagen fibril longitudinal orientation.³⁶ A retrospective study conducted by Ciampi et al²⁵ with 36-month follow-up reported on 152 patients in three groups (open RCR only, open RCR with collagen patch, and open repair with polypropylene patch) to determine the efficacy of biologic versus synthetic grafts. These authors found a significantly higher University of California, Los Angeles (UCLA) shoulder rating scale and lower retear rates in patients treated with synthetic grafts when compared with both control patients and biologic grafts.²⁵ Additionally, the authors reported significantly improved range of motion (elevation in the scapular plane) and abduction strength in the polypropylene patch group.²⁵ A 2014 study of 18 patients treated with RCR with augmentation with
a poly-l-lactic acid bioabsorbable patch reported intact repairs in 83% of patients at 12 months and 78% of patients at 42 months after surgery.²⁶ Ten patients treated with open RCR augmented with polycarbonate polyurethane patch had a 90% intact rate at 12 months with no adverse events recorded.²⁷ Audenaert et al²⁸ studied the use of polyester mesh to bridge gaps between rotator cuff insertion point and tendon in 41 patients and found that the Constant and Murley scores improved and patients experienced pain relief, with 2 patients experiencing moderate to severe pain and 4 patients with structural failure. Nada et al²⁹ described a case series using polyester grafts for arthroscopic repair of massive rotator cuff tears in 21 individuals and found that 90.5% of individuals had intact repairs at 36 months, with a mean patient satisfaction score of 90%.²⁹ The authors also reported significant improvements in abduction strength and range of motion (flexion, abduction, external rotation, and internal rotation) when comparing patients’ preoperative and postoperative scores; however, there was no control group in this study for comparison.²⁹ In summary, although there are a few small studies that suggest that synthetic grafts may have potential for improved outcomes and function in the setting of RCR, these studies are limited by their retrospective nature and midterm follow-up data. Prospective randomized controlled studies are necessary to improve clinical confidence in the efficacy of synthetic scaffolds for augmentation of massive RCRs.

TABLE 1 Summary of Clinical Evidence for the Use of Grafts in Rotator Cuff Repair

Xenografts
*Examples:* porcine SIS, porcine dermal matrix
Reference	Year	Graft Type	Results
Schlegel et al²⁰	2021	Bovine Achilles tendon-derived collagen implant	New tissue fill-in on MRI in 100% of intermediate-grade tears and 95% of high-grade tears; no control group
Bryant et al¹⁸	2016	Porcine SIS	No differences in failure rate, WORC index scores, or postoperative narcotic use compared with nongraft control groups
Lederman et al¹⁹	2016	Porcine dermal matrix	Retear rates of 43.9%; no control group
Nicholson et al²¹	2007	Porcine dermal matrix; porcine SIS	No differences in failure loads at 24 weeks after ovine infraspinatus repair between suture repair, SIS, and dermal matrix groups
*Conclusions:* Porcine-derived xenografts have fallen out of favor because of little evidence of efficacy, high complication rates, and the potential for robust inflammatory/immunogenic responses due to the presence of porcine DNA. In contrast, relatively favorable results have been reported using a resorbable bovine Achilles tendon-derived collagen implant.
Allografts
*Examples:* Human dermal allografts
Reference	Year	Graft type	Results
Wong et al²²	2010	Acellular dermal matrix	Improved postoperative outcomes scores; no control group
Barber et al²³	2012	Acellular dermal matrix	Improved ASES and Constant scores and decreased retear rate in patients with dermal allografts compared with nongraft controls
Johnson et al²⁴	2020	Acellular dermal matrix	93% of tendons repaired with dermal allograft were intact 35 months postoperatively
*Conclusions:* Use of dermal allografts may result in some functional improvements and lower retear rates compared with rotator cuff repairs without dermal allograft. However, dermal allografts may have inferior biomechanical properties compared with the native rotator cuff tendon. Additionally, differences in graft structure may affect the ability of progenitor cells to adhere to/proliferate within the graft.
Synthetic grafts
*Examples:* Polypropylene, polycarbonate polyurethane, poly-l-lactic acid
Reference	Year	Graft type	Results
Ciampi et al²⁵	2014	Polypropylene patch	Lower retear rates (17% versus 41% in control) and improved functional outcomes in synthetic patch group
Proctor²⁶	2014	Poly-l-lactic acid patch	78% of repairs intact at 42 months postoperatively; no control group
Encalada-Diaz et al²⁷	2011	Polycarbonate polyurethane patch	10% retear rate at 12 months postoperatively; no control group
Audenaert et al²⁸	2006	Polyester mesh	3 of 41 patients had new tear at latest follow-up; no control group
Nada et al²⁹	2010	Polyester graft	90.5% of patients had intact repair at 36 months postoperatively; no control group
*Conclusions:* Synthetic grafts may be biomechanically stronger than biologic patches and carry a lower risk of generating an inflammatory or immunogenic reaction. Although there are some early promising results, most of the literature is composed of small case series without control groups.
ASES = American Shoulder and Elbow Surgeons, SIS = small intestine submucosa, WORC = Western Ontario Rotator Cuff Index