Bony increased-offset-reverse shoulder arthroplasty: 5 to 10 years' follow-up

BACKGROUND

Glenoid lateralization has been shown to be the most imortant factor in maximizing passive range of motion and shoulder stability while preventing scapular impingement and notching. We aimed to evaluate mid- to long-term functional and radiologic outcomes after bony increased-offset-reverse shoulder arthroplasty (BIO-RSA) using a Grammont-style (medialized) humeral implant.

METHODS

The study included 143 consecutive shoulders (140 patients; mean age, 72 years) treated with a BIO-RSA for rotator cuff deficiency. A cylinder of autologous cancellous bone graft, harvested from the humeral head, was placed between the reamed glenoid surface and baseplate; fixation was achieved using a long central peg (25 mm) and 4 screws. A large baseplate (29 mm) with a small baseplate sphere (36 mm) was used in 77% of cases, and a Grammont-style (medialized) humeral implant with 155° of inclination was used in all cases. All patients underwent clinical and radiographic assessment at a minimum of 5 years after surgery; in addition, 86 cases (60%) underwent computed tomography scan assessment.

RESULTS

At a mean follow-up of 75 months (range, 60-126 months), the survivorship of the BIO-RSA using revision as an endpoint was 96%. No cases of dislocation or humeral loosening were observed. Overall, 118 patients (83%) were either very satisfied (61%) or satisfied (22%). The adjusted Constant score improved from 40% ± 18% to 93% ± 23%, and the Subjective Shoulder Value improved from 31% ± 15% to 77% ± 18% (P < .001). The humeral bone graft incorporated completely in 96% of cases (137 of 143). Severe inferior scapular notching (grade 3 or 4) occurred in 18% (24 of 136). The risk of postoperative notching correlated to a lower body mass index (P < .05), superior glenosphere inclination (P = .02), and high or flush glenosphere positioning (P = .035).

CONCLUSIONS

BIO-RSA is a safe and effective technique to lateralize the glenoid, providing consistent bone graft healing, excellent functional outcomes, a low revision rate, and a high rate of patient satisfaction. Thin patients (with a low body mass index) and glenosphere malposition (with persistent superior inclination and/or insufficient lowering of the baseplate and sphere) are associated with higher risk of scapular notching.Our data confirm the importance of implanting the baseplate with a neutral inclination (reverse shoulder arthroplasty angle < 5°) and with sufficient glenosphere inferior overhang (>5 mm) in preventing scapular notching. The use of a less medialized humeral implant (135° or 145° inclined) and smaller (25-mm) baseplate (when using a small, 36-mm sphere) should allow reduction in the incidence of scapular notching.

Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion

BACKGROUND

Glenoid deficiency and erosion (excessive retroversion/inclination) must be corrected in reverse shoulder arthroplasty (RSA) to avoid prosthetic notching or instability and to maximize function, range of motion, and prosthesis longevity. This study reports the results of RSA with an angled, autologous glenoid graft harvested from the humerus (angled BIO-RSA).

METHODS

A trapezoidal bone graft, harvested from the humeral head and fixed with a long-post baseplate and screws, was used to compensate for residual glenoid bone loss/erosion. For simple to moderate (<25°) glenoid defects, standardized instrumentation combined with some eccentric reaming (<15°) was used to reconstruct the glenoid and obtain neutral implant alignment. For severe (>25°) and complex (multiplanar) glenoid bone defects, patient-specific grafts and guides were used after 3-dimensional planning. Patients were reviewed with minimum 2 years of follow-up. Mean follow-up was 36 months (range, 24-81 months). Preoperative and postoperative measurements of inclination and version were performed in the plane of the scapula on computed tomography images.

RESULTS

The study included 54 patients (41 women, 13 men; mean 73 years old). Fifteen patients had combined vertical and horizontal glenoid bone deficiency. Among E2/E3 glenoids, inclination improved from 37° (range, 14° to 84°) to 10.2° (range -28° to 36°, P < .001). Among B2/C glenoids, retroversion improved from -21° (range, -49° to 0°) to -10.6° (-32° to 4°, P = .06). Complete radiographic incorporation of the graft occurred in 94% (51 of 54). Complications included infection in 1 and clinical aseptic baseplate loosening in 2. Mild notching occurred in 25% (13 of 51) of patients. Constant-Murley and Subjective Shoulder Value assessments increased from 31 to 68 and from 30% to 83%, respectively (P < .001).

CONCLUSION

Angled BIO-RSA predictably corrects glenoid deficiency, including severe (>25°) multiplanar deformity. Graft incorporation is predictable. Advantages of using an autograftharvested in situ include bone stock augmentation, lateralization, low donor-site morbidity, low relative cost, and flexibility needed to simultaneously correct posterior and superior glenoid defects.

Tibial tubercule osteotomy during medial approach to difficult knee arthroplasties

INTRODUCTION

Osteotomy of the anterior tibial tubercle (TT) is well known as the approach to difficult knees, in particular those with a low patella, but it has a poor reputation.

PATIENTS AND METHODS

This technique was used 21 times in 20 patients (10 males and 10 females) with a mean age of 71 years (range, 42-90 years) for 14 prosthesis revisions (three for septic loosening, 11 for aseptic loosening) and seven knees that had not anteriorly received prior implants (three osteotomies, one synovectomy). The surgical technique included a long (7 cm), thick (>1 cm) fragment retaining its lateral muscle hinge with compression fixation using two screws. In cases with a low patella, the TT was proximally displaced, with amplitude limited by the tibial baseplate. Follow-up was clinical and radiological, lasting a mean 54 months (range, 8-195 months). The clinical results were assessed using the IKS score and the radiological results using the measurement of the patellar index according to the protocol described during the Lyon Knee Days.

RESULTS

The mean preoperative IKS scores were: knee, 57.5±22.4; function, 42.6±21.5 (total, 100±33.9); postoperative scores: knee, 84±11.6; function 65±28 (total, 149±32.9). The joint range of motion increased from 73±34.9 to 88±21.1 for a mean gain of 15±23.1. We found a traumatic nondisplaced tibia fracture around a tibial stem, treated conservatively, two stress fractures of the immediate proximal part overhanging the TT with no consequences, one case of stiffness (not related to the osteotomy), and one case of localized skin necrosis on a knee that had undergone several surgeries (secondary scarring). No cases of malunion or migration of the TT were noted. The mean deliberate proximal migration obtained was 13 mm±6 (range, 8-33 mm). The patellar index increased from 0.18±0.20 (range, -0.39 to 0.57) to 0.33±0.19 (range, -0.13 to 0.60).

DISCUSSION

This series shows that the indications are rare but invaluable, facilitating the approach and most particularly making it possible to modify the position of the patella, thus contributing to increasing the joint range of motion. Fixation with two screws carries no risk of disassembly if the technique is rigorous. Patellar translation is limited by the tibial tray.