Factors affecting internal rotation after reverse shoulder arthroplasty.

BACKGROUND: The limitation or loss of internal rotation (IR) after the surgery is a major problem in reverse shoulder arthroplasty (RSA). The particular factors associated with postoperative IR remain unclear. We aimed to analyze the predictors of IR after RSA. METHODS: We included primary RSA patients with the following implants and a minimum of 1-year follow-up: Wright Aequalis (n = 25), DJO Encore (n = 29), Biomet Comprehensive (n = 40), and Exactech Equinoxe (n = 29). Age, sex, dominant hand, primary diagnosis, implant type, preoperative critical shoulder angle, pre- and postoperative acromiohumeral distance, lateral offset of implant, glenosphere inclination, peg-glenoid rim distance (PGRD), glenosphere overhang, scapular notching, subscapularis (SSc) repair, pre- and postoperative ROM, and functional scores were assessed. IR was assessed using a 10-point scale based on the following anatomical levels: from the greater trochanter to the buttocks (2 points), from the sacrum to L4 (4 points), from L3 to L1 (6 points), from T12 to T8 (8 points), and from T7 to T1 (10 points). Univariable and multivariable analyses were performed to identify the factors affecting the IR after RSA. RESULTS: One hundred twenty-three shoulders (123 patients) with a mean follow-up of 30.59 ± 19.55 (range, 12-83) months were evaluated. In the univariable analysis, preoperative diagnosis [odds ratio (OR) = 0.243, P = 0.001], implant type (P = 0.002), PGRD (OR = 1.187, P = 0.003), and preoperative IR (P < 0.001) were found to be factors associated with postoperative IR. Preoperative IR was the only factor associated with postoperative IR in the multivariable analysis (P < 0.001). Patients with preoperative IR scores of 10 or 8 points showed significantly better IR after RSA than those with preoperative IR scores of 2 or 4 points (10 points vs. 2 or 4 points; OR = 15.433, P = 0.002, 8 points vs. 2 or 4 points; OR = 6.078, P < 0.001). CONCLUSION: Preoperative IR was the only independent factor for IR after RSA. Patients with excellent preoperative IR had better postoperative IR than those with poor preoperative IR. Preoperative diagnosis, implant type, SSc repair, implant lateralization, glenosphere inferior placement, and scapular notching were not identified as independent predictors of IR after RSA in our sample size.

Evaluation of analgesic efficacy and opioid sparing effect of pregabalin after arthroscopic rotator cuff repair surgery: A retrospective cohort study.

BACKGROUND: Considering the adverse effects of opioids, it is essential to minimize their consumption for postoperative pain control. Studies have reported the opioid sparing effects of pregabalin, with conflicting results. Evidence for administering pregabalin in a multimodal regimen after arthroscopic rotator cuff repair surgery is limited. METHODS: A total of 64 patients who underwent arthroscopic rotator cuff repair were enrolled in the cohort, and their data were retrospectively analyzed to evaluate the ability of pregabalin for postoperative analgesia and opioid sparing. The pregabalin group (n = 32) received additional pregabalin 75 mg for 2 weeks from the day before the surgery with the standard pain medications; in contrast, the control group (n = 32) was prescribed the standard pain medications alone. The total volume of patient-controlled anesthesia, doses of oral oxycodone and intravenous morphine as rescue analgesics, number of adverse events, and patient satisfaction based on the numeric rating scale (0-10) were assessed. Further, we used the visual analog scale for evaluating pain and function for 6 months in each group. RESULTS: Total patient-controlled anesthesia volume, number of patient-controlled anesthesia attempts on the day of surgery, and total oral oxycodone consumption were significantly lower in the pregabalin group. Visual analog scale scores for pain and function showed no significant differences. Although the total number of adverse effects (nausea, vomiting, dizziness, dry mouth, urinary retention, itching sense, or constipation) was higher in the pregabalin group than in the control group, the difference was not statistically significant. CONCLUSION: Our multimodal regimen with pregabalin significantly reduced opioid consumption with similar adverse effects. However, there was no significant difference in the pain score. We recommend pregabalin as an additional analgesic for arthroscopic rotator cuff repairs, especially for medium to large sized tears.

Biomechanical comparison of three 2.7-mm screws and two 3.5-mm screws for fixation of simple oblique fractures in human distal fibulae.

BACKGROUND: Fixation of simple oblique fractures of short tubular bones with only inter-fragmentary screws is simple and clinically useful. This study compared the biomechanical properties of fixation using three 2.7-mm mini-screw and two conventional 3.5-mm lag screw constructs for simple oblique fractures of the distal fibula in human osteoporotic bone. METHODS: Simple oblique fractures of the distal fibula at the level of the syndesmosis were simulated in 15 paired fresh frozen ankles, and the calcaneal bone mineral density was measured in each. Fixation with either three 2.7-mm mini-screws (new system) or two 3.5-mm cortical screws (conventional system) was performed in each pair of ankles. The sample size for each type of stress (cantilever bending stress, five pairs; external rotational load to failure, 10 pairs) was calculated before the test. The biomechanical variables (maximal failure load and construct stiffness) of the two fixation groups were compared using a non-inferiority test method with a pre-specified non-inferiority margin. FINDINGS: The bone mineral density of the calcaneus was assessed as osteoporotic based on reference values for 20- to 29-year-old healthy Koreans. The new system was not inferior to the conventional system in terms of the tested biomechanical properties. The construct failure was initiated from the distal-most screw hole in the anterior cortex. INTERPRETATION: Fixation with only three 2.7-mm mini-screws provided biomechanical stability comparable to two 3.5-mm cortical screws for simple oblique osteoporotic fractures in the distal fibula under one-shot stress. Mini-screw application for this common fracture might extend the scope of surgical indications for the screws-only fixation method.

A polymer-supported Cinchona-based bifunctional sulfonamide catalyst: a highly enantioselective, recyclable heterogeneous organocatalyst.

The design, synthesis, and catalytic application of a highly enantioselective and indefinitely stable polymer-supported Cinchona-based bifunctional sulfonamide is reported.