Faculty Bibliography

PURPOSE: To compare the biomechanical performance of medial row suture placement relative to the musculotendinous junction (MTJ) in a cadaveric transosseous equivalent suture bridge (TOE-SB) double-row (DR) rotator cuff repair (RCR) model. METHODS: A TOE-SB DR technique was used to reattach experimentally created supraspinatus tendon tears in 9 pairs of human cadaveric shoulders. The medial row sutures were passed either near the MTJ (MTJ group) or 10 mm lateral to the MTJ (rotator cuff tendon [RCT] group). After the supraspinatus repair, the specimens underwent cyclic loading and load to failure tests. The localized displacement of the markers affixed to the tendon surface was measured with an optical tracking system. RESULTS: The MTJ group showed a significantly higher (P = .03) medial row failure (5/9; 3 during cyclic testing and 2 during load to failure testing) compared with the RCT group (0/9). The mean number of cycles completed during cyclic testing was lower in the MTJ group (77) compared with the RCT group (100; P = .07) because 3 specimens failed in the MTJ group during cyclic loading. There were no significant differences between the 2 study groups with respect to biomechanical properties during the load to failure testing. CONCLUSIONS: In a cadaveric TOE-SB DR RCR model, medial row sutures through the MTJ results in a significantly higher rate of medial row failure. CLINICAL RELEVANCE: In rotator cuff tears with tendon tissue loss, passage of medial row sutures through the MTJ should be avoided in a TOE-SB RCR technique because of the risk of medial row failure.

BACKGROUND: The results of open and arthroscopic instability repairs have been shown to be equivalent in recent literature. PURPOSE: To compare the time to recurrence (TTR) of instability and disease-specific outcome measures in patients undergoing open and arthroscopic Bankart repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients with recurrent traumatic anterior shoulder instability and a Bankart lesion on diagnostic arthroscopy underwent either open Bankart repair (OB) or arthroscopic Bankart and suture capsulorrhaphy (ABSC) using suture anchors. There was a minimum follow-up of 24 months. The primary outcome measures included Western Ontario Shoulder Instability Index (WOSI) score and time to recurrence of instability (dislocation or subluxation). Rowe score, Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and Short Form-12 (SF-12) score were also compared. RESULTS: A total of 82 shoulders in 80 patients (ABSC, n = 58; OB, n = 24) were evaluated at a mean of 39 months postoperatively. There were 4 clinical failures in the OB group (4 dislocations) and 7 clinical failures in the ABSC group (2 dislocations and 5 subluxations; P = .72 vs OB). The mean time to recurrence of postoperative instability was significantly shorter in the ABSC group (12.6 +/- 2.7 months) compared with the OB group (34.2 +/- 12 months; P = .04). The WOSI score in the OB group (265 +/- 48.1) was better but not statistically significantly compared with the ABSC group (449.8 +/- 63.8; P = .06). CONCLUSION: The time to recurrence of instability after open Bankart repair is significantly longer compared with arthroscopic Bankart repair. CLINICAL RELEVANCE: Delayed time to recurrence after open Bankart repair suggests that the open technique may be more suited to withstand the high stress and demands of a heavy-duty profession (contact athletes and heavy manual labor).

The long head of biceps tendon (LHBT) is frequently involved in rotator cuff tears and can cause anterior shoulder pain. Tendon hypertrophy, hourglass contracture, delamination, tears, and tendon instability in the bicipital groove are common macroscopic pathologic findings affecting the LHBT in the presence of rotator cuff tears. Failure to address LHBT disorders in the setting of rotator cuff tear can result in persistent shoulder pain and poor satisfaction after rotator cuff repair. Tenotomy or tenodesis of the LHBT are effective options for relieving pain arising from the LHBT in the setting of reparable and selected irreparable rotator cuff tears.

The long head of biceps tendon (LHBT) is a well-recognized cause of anterior shoulder pain. Tenotomy or tenodesis of the LHBT is an effective surgical solution for relieving pain arising from the LHBT. Cosmetic deformity of the arm, cramping or soreness in the biceps muscle, and strength deficits in elbow flexion and supination are the three most common adverse events associated with tenotomy of the LHBT. Complications associated with tenodesis of the LHBT include loss of fixation resulting in cosmetic deformity, residual groove pain, pain or soreness in the biceps muscle, infection, stiffness, hematoma, neurologic injury, vascular injury, proximal humerus fracture, and reflex sympathetic dystrophy.

BACKGROUND:Irreparable rotator cuff (RC) tears without arthritis is a challenging clinical problem in young adults. Reverse total shoulder arthroplasty (RTSA) has been proposed as one of the surgical treatment options for this condition. METHODS:In this review, we discuss the current understanding of the role of RTSA for the management of irreparable RC tears without arthritis based on authors personal experience and available scientific literature. RESULTS:Reverse total shoulder arthroplasty (RTSA) is a constrained arthroplasty system that can allow the deltoid and remaining rotator cuff to substitute for the lost function of irreparable RC. Furthermore, the pain relief is consistent with often a dramatic improvement in patient comfort, shoulder function and stability. In patients with pseudoparalysis of the shoulder without advanced arthritis, RTSA effectively restores forward elevation above the shoulder but may not dramatically improve external (ER) or internal rotation (IR). However, due to concerns over implant longevity, caution has to be exercised when using RTSA for symptomatic irreparable RC tears with preserved active forward elevation (AFE) and in patients less than 65 years of age. CONCLUSION/CONCLUSIONS:RTSA is a reasonable surgical option for irreparable rotator cuff repair without arthritis. However, caution should be exercised when offering RTSA to young patients and patient without pseudoparalysis because they can have a higher complication and dissatisfaction rate. In addition, longevity of RTSA and subsequent need for revision surgery remains a significant concern in this population.

"Ex vivo" regional gene therapy using lentiviral (LV) vectors to over-express bone morphogenetic protein 2 (BMP-2) is an effective way to enhance bone healing in animal models. Here, we evaluated two different "ex vivo" approaches using either "same day" rat bone marrow cells (SDRBMCs) or cultured rat bone marrow cells (C-RBMCs), both transduced with a LV based two-step transcriptional activation system overexpressing GFP (LV-TSTA-EGFP), to assess the fate of the transduced cells and the safety of this approach. The transduced cells were implanted in femoral defects of syngeneic rats. Animals were sacrificed at 4, 14, 28 and 56 days after surgery (n=5 per group). Viral copies were detectable in the defect site of SD-RBMC group and gradually declined at 8w (5 log decrease compared to 4d). In the C-RBMC animals, there was a 2-4 log decline in the viral copy numbers at 2w and 4w, but at 8w there was a relative rise (about 100 fold) in the number of the viral vectors in the defect site of 4 (out of 5) animals compared to the previous time points. For both gene transfer approaches, the pattern of tissue distribution was non-specific and no histological abnormalities were noted in either group. In summary, we demonstrated that the LV-TSTA transduced cells remain in the defect site for at least 56 days, though the numbers decreased over time. There were no consistent findings of viral copies in internal organs which is encouraging with respect to the development of this strategy for use in humans.

Biological therapies that can augment tendon to bone healing are desirable for the management of clinical conditions such as failed rotator cuff (RC) repair, chronic retracted RC tears, and RC tears in a compromised host (smokers, chronic medical conditions including diabetes). Bone marrow aspirate and platelet-rich plasma are 2 autologous biological therapies that are currently being used clinically to augment tendon to bone healing. The indications for this biological therapy, its efficacy, duration, dosage, and optimum cellular concentration are in the process of evolution and require continued ongoing investigations for further optimization. In this technique article, we describe the biological basis and our technique for the preparation and use of platelet-rich plasma and bone marrow aspirate for augmentation of RC repair

There exists a range of surgical and non-surgical approaches to the treatment of both acute and chronic tendon injuries. Despite surgical advances in the management of acute tears and increasing treatment options for tendinopathies, strategies frequently are unsuccessful, due to impaired mechanical properties of the treated tendon and/or a deficiency in progenitor cell activities. Hence, there is an urgent need for effective therapeutic strategies to augment intrinsic and/or surgical repair. Such approaches can benefit both tendinopathies and tendon tears which, due to their severity, appear to be irreversible or irreparable. Biologic therapies include the utilization of scaffolds as well as gene, growth factor, and cell delivery. These treatment modalities aim to provide mechanical durability or augment the biologic healing potential of the repaired tissue. Here, we review the emerging concepts and scientific evidence which provide a rationale for tissue engineering and regeneration strategies as well as discuss the clinical translation of recent innovations.

Systemic administration of a sclerostin neutralizing antibody (Scl-Ab) has been shown to enhance fracture callus density and strength in several animal models. In order to further evaluate the potential of Scl-Ab to improve healing in a bone defect model,we evaluated Scl-Ab in a 3mm femoral defect in young male outbred rats. Scl-Ab was given either continuously for 6 or 12 weeks after surgery or with 2 weeks of delay for 10 weeks. Bone formation was assessed by radiographs, micro-CT, and histology. Complete bony union was achieved in only a few defects after 12 weeks of healing (Scl-Ab treated 5/30, vehicle treated 1/15). micro-CT evaluation demonstrated a significant increase in the BV/TV in the defect in the delayed treatment group (65%, p<0.05), but a non-significant increase in the continuous group (35%, p = 0.11) compared to control. However, both regimens induced an anabolic response in the bone proximal and distal to the defect and in the un-operated femurs. We demonstrate that treatment with Scl-Ab can enhance bone repair in a bone defect and in the surrounding host bone, but lacks the osteoinductive activity to heal it. This agent seems to be most effective in bone repair scenarios where there is cortical integrity.