Revision for instability following reverse total shoulder arthroplasty: outcomes and risk factors for failure.

BACKGROUND: Revision of unstable reverse shoulder arthroplasty (RSA) is significantly challenging, with recurrence rates ranging from 20% to 40%. The purpose of this study was to identify factors associated with recurrent instability. The factors studied included (1) indication for revision RSA (failed primary RSA vs. failed revision RSA), (2) previous attempt at stabilization, (3) mechanism of instability, (4) clinical history of instability, and (5) surgical technique. Outcomes were reported in patients with 2-year follow-up. METHODS: All patients undergoing RSA for instability at our institution were identified. A total of 43 surgical procedures in 36 patients were included. Arthroplasty indication prior to instability (14 failed primary RSAs vs. 22 failed revision RSAs), instances of prior attempts at stabilization (14 patients treated at outside institution), mechanism-of-instability classification, clinical history of instability (17 recurrent and 26 chronic cases), and surgical technique were collected. Stability at final follow-up (minimum, 12 months) and clinical outcomes at 2-year follow-up were assessed. RESULTS: Overall, 32 of 36 patients (89%) required 38 revisions to achieve stability at final follow-up (mean, 53 ± 47 months; range, 12-210 months). On comparison of stability by indication, stability was achieved in 13 of 14 patients (93%) in the failed primary group (mean, 65 ± 59 months; range, 12-210 months) compared with 19 of 22 (86%) in the failed revision group (mean, 45 ± 36 months; range, 12-148 months; P = .365). The average number of procedures per patient was 3 (range, 2-10) in the failed primary group vs. 4.5 (range, 3-7) in the failed revision group (P = .008). Stability was achieved in 12 of 14 patients (86%) with a history of failed stabilization procedures. The most common mechanism leading to persistent instability was loss of compression. Stability was achieved in 14 of 16 patients treated for recurrent instability compared with 18 of 20 treated for chronically locked dislocation (P = .813). Continued instability occurred in 33% of patients who underwent glenoid side-only management, 33% who underwent humeral side-only management, and 10% who underwent bipolar revision tactics. At 2-year follow-up, stability was achieved in 18 of 21 patients, with improvements in the American Shoulder and Elbow Surgeons (ASES) score, forward flexion, abduction, external rotation, and the Simple Shoulder Test score (P = .016, P < .01, P = .01, P < .01, and P = .247, respectively). CONCLUSION: Patients who underwent multiple revisions after failed previous arthroplasty will require more surgical attempts to achieve stability compared with patients who underwent a revision after failed primary RSA. Loss of compression was the most common mechanism of persistent instability. Stabilization was more reliably achieved in cases of recurrent instability than in cases of chronically locked dislocation. Continued instability was noted in one-third of patients who underwent humeral side-only or glenoid side-only revisions and in 10% of those who underwent bipolar revisions. Patients in whom stabilization was successful had improved clinical outcomes.

Outcomes of femoral head allograft for the management of glenoid bone defects in revision reverse shoulder arthroplasty: a case-controlled study.

BACKGROUND: Revision shoulder arthroplasty often requires management of glenoid bone defects. Options include using allograft, harvesting iliac crest autograft, or using augmented metal components. The purpose of this study is to report outcomes of revision shoulder arthroplasty requiring management of glenoid bone defects with femoral head allograft in a large cohort of patients using a single reverse shoulder implant system and compare them to a matched cohort based on the indication for surgery. Outcomes of patients who had successful glenoid reconstruction were compared to those that required a re-revision, and to a control group that was revised without the need for bone graft. METHODS: This was a retrospective review of data collected from 2009 to 2018. There were 36 patients in the bone graft group and 52 in the control group. All patients underwent revision to a reverse shoulder arthroplasty to manage a failed total shoulder arthroplasty (n = 29 and 11), hemiarthroplasty (n = 1 and 24), or reverse shoulder arthroplasty (n = 6 and 17). All patients had a minimum of 2 yr of clinical follow-up. The primary endpoint was survival of baseplate fixation. Secondary outcomes included range of motion and functional outcome scores. Patients that had recurrent baseplate failure and were re-revised were compared to patients with bone graft that did not require additional surgery, and to patients who were revised without the need for bone graft. Patients who required revisions for reasons other than recurrent baseplate failure were also recorded. RESULTS: Five of 36 (14%) patients had recurrent baseplate failure. Mean time to failure was 12 mo. Three of 5 had successful re-implantation of another baseplate. Two of 5 were revised to a hemi arthroplasty after failure of their revisions. Preoperative American Shoulder and Elbow Surgeons scores were 31 in the grafted patients that did not require re-revision, 39 in the grafted patients that required re-revision, and 33 in the control group. Final American Shoulder and Elbow Surgeons scores were 64, 36, and 56, respectively. One patient required revision surgery not related to baseplate failure. There were no baseplate failures in the control group. CONCLUSION: The use of femoral head allograft to manage glenoid bone defects in the revision setting produces predictable improvement in functional outcomes that is not inferior to those in patients revised without bone graft. However, there is a 14% rate of baseplate failure.

Biomechanical assessment of lateral ulnar collateral ligament repair and reconstruction with or without internal brace augmentation.

BACKGROUND: Surgical treatment of posterolateral rotatory instability (PLRI) using primary repair or reconstruction of the lateral collateral ligament complex have proven inconsistent. This study aimed to test the hypothesis that augmentation of LUCL repair or palmaris longus tendon reconstruction using a suture tape augmentation would be associated with less rotational displacement and greater torque load to failure (LTF) compared with nonaugmented constructs. METHODS: Cadaveric elbows (n = 12 matched pairs) were used. Baseline stiffness and displacement values were obtained. The LUCL was transected followed by repair alone, repair with augmentation, reconstruction with palmaris longus graft, or reconstruction with augmentation. Specimens were retested including torque LTF. Paired t tests were performed to assess the biomechanical effects of augmentation. RESULTS: Augmentation was associated with higher LTF than repair and reconstruction alone (P = .008 and .047, respectively). Displacement was less with augmentation in reconstruction groups (P = .048) but not in repair groups. Suture tape augmentation maintained rotational stiffness better than repair alone (P = .01). Although reconstruction with augmentation maintained rotational stiffness better than nonaugmented reconstruction, the differences were not statistically significant (P = .057). Mode of failure for repair alone was predominantly suture pulling through repaired ligament. Augmented repairs primarily failed at the anchor-bone interface. Modes of failure for both reconstruction groups were similar, including graft tearing and/or slipping at the anchor. CONCLUSION: When positioned in neutral forearm rotation and 90o of flexion to simulate postoperative conditions, augmentation of LUCL repair or tendon reconstruction using suture tape is associated with better resistance to rotational loads compared with nonaugmented repair or reconstruction, while maintaining near-native rotational stiffness.

The risk of deep vein thrombosis in total joint patients compared to orthopaedic trauma patients: Need for new prevention guidelines.

BACKGROUND: The development of Deep Vein Thrombosis (DVT) is a major concern following orthopaedic surgery. No study has yet to compare the rate and risk factors for DVT between total joint and orthopaedic trauma patients. To evaluate if DVT prophylaxis for trauma should differ from total joints, we explored the rate and risk factors for DVT between both cohorts. METHODS: Using a CPT code search from 2005 to 2013 in the ACS-NSQIP database, 150,657 orthopaedic total joint patients and 44,594 orthopaedic trauma patients were identified. DVT complications, patient demographics, preoperative comorbidities, and surgical characteristics were collected for each patient. A chi-squared test was used to compare the risk factors for DVT between orthopaedic trauma and total joint patients. A multivariable logistic regression model was built to adjust for comorbidities for each cohort. RESULTS: The rate of DVT diagnosis in the total joint population was 0.8% (N = 1186) and 0.98% (N = 432) in the orthopaedic trauma population (p = 0.57). After controlling for individual comorbidities, dyspnea, peripheral vascular disease, and renal failure were significant risk factors for DVT in total joint patients (p < 0.05), whereas age, ascites and steroid use were significant risk factors for DVT in orthopaedic trauma patients (p < 0.05). CONCLUSIONS: Historically, the risks for DVT in total joints have been emphasized, yet based on our results, the incidence of DVT is the same for orthopaedic trauma. However, the risk factors varied. It is therefore important to consider specialty-specific DVT prophylaxis for orthopaedic trauma patients in order to improve care and reduce postoperative complications.