Do Long-Segment Blocking Screws Increase the Stability of Intramedullary Nail Fixation in Proximal Tibia Fractures, Eliminating the "Bell-Clapper Effect?"

OBJECTIVES: To determine change in stiffness and horizontal translation of a geriatric extra-articular proximal tibia fracture model after intramedullary nailing with distal (long)-segment blocking screws versus proximal (short)-segment blocking screws. METHODS: Unstable extra-articular proximal tibia fractures (OTA/AO 41-A3) were created in 12 geriatric cadaveric tibias. Intramedullary nails were locked with a standard construct (4 proximal screws and 2 distal screws). Specimens were then divided into 2 groups (6 matched pairs per group). Group 1 had a blocking screw placed lateral to the nail in the proximal segment (short segment). Group 2 had a blocking screw placed 1 cm distal to the fracture and medial to the nail (long segment). Specimens were then axially loaded and cycled to failure or cycle completion (50,000 cycles). RESULTS: Long-segment blocking screws significantly decreased the amount of horizontal translation at the fracture site compared with short-segment screws (0.77 vs. 2.0 mm, P = 0.039). They also resulted in a greater trend towards greater baseline stiffness, (807.32 ± 216.95 N/mm vs. 583.12 ± 130.1 N/mm, P = 0.072). There was no difference in stiffness after cyclic loading or survival through 50,000 cycles between the long-segment and short-segment groups. CONCLUSION: Long-segment blocking screws added to an intramedullary nail construct resulted in decreased horizontal translation at the fracture site compared with short-segment screws in this model of a geriatric proximal tibia fracture. CLINICAL RELEVANCE: Blocking screws are commonly used to aid in fracture alignment during intramedullary nailing of proximal tibia fractures. Even when not required to attain or maintain alignment, the addition of a blocking screw in either the proximal or the distal (long) segment may help mitigate the "Bell-Clapper Effect" in geriatric patients.

An Injectable Calcium Phosphate Bone Graft Substitute Improves the Pullout Strength of Various Suture Anchor Designs in an Osteoporotic Bone Model.

Purpose: To compare various suture anchor designs with and without calcium phosphate (CaP) augmentation in an osteoporotic foam block model and decorticated proximal humerus cadaveric model. Methods: This was a controlled biomechanical study, consisting of 2 parts: (1) an osteoporotic foam block model (0.12 g/cc; n = 42) and (2) a matched pair cadaveric humeral model (n = 24). Suture anchors selected were an all-suture anchor, PEEK (polyether ether ketone)-threaded anchor, and a biocomposite-threaded anchor. For each study arm, one half the samples were first filled with injectable CaP and the other half were not augmented with CaP. For the cadaveric portion, the PEEK- and biocomposite-threaded anchors were assessed. Biomechanical testing consisted of a stepwise, increasing load protocol for a total of 40 cycles, followed by ramp to failure. Results: For the foam block model, the average load to failure for anchors with CaP was significantly greater when compared with anchor fixation augmented without CaP; the all-suture anchor was 135.2 ± 20.2 N versus 83.3 ± 10.3 N (P = .0006); PEEK was 131 ± 34.3 N versus 58.5 ± 16.8 N (P = .001); and biocomposite was 182.2 ± 64.2 N versus 80.8 ± 17.4 N (P = .004). For the cadaveric model, the average load to failure for anchors augmented with CaP was again greater than anchor fixation without CaP; PEEK anchors went from 41.1 ± 21.1 N to 193.6 ± 63.9 N (P = .0034) and biocomposite anchors went from 70.9 ± 26.6 N to 143.2 ± 28.9 N (P = .004). Conclusions: Augmenting various suture anchors with CaP has shown to significantly increase pull-out strength and stiffness in an osteoporotic foam block and time zero cadaveric bone model. Clinical Relevance: Rotator cuff tears are common in the elderly patients, in whom poor bone quality jeopardizes treatment success. Exploring methods that increase the strength of fixation in osteoporotic bone to improve outcomes in this patient population is important.

Three-Dimensional Scapular Border Method for Glenoid Version Measurements.

Variations among methods to measure glenoid version have created uncertainty regarding which method provides the most consistent measurements of morphology. Greater deformity may also make accurate depiction of the native morphology more challenging. This study examined 4 current methods (Friedman, corrected Friedman, Ganapathi-Iannotti, and Matsumura) and an experimental scapular border-derived coordinate system method, to compare measurement inconsistencies between methods and reference systems and assess the impact of glenoid deformity on measured glenoid version. Methods: Three-dimensional scapulae were created from computed tomography (CT) scans of 74 shoulders that had undergone arthroplasty (28 A2, 22 B2, 10 B3, and 14 C glenoids) and 34 shoulders that had not undergone arthroplasty. Glenoid version measurements were made in Mimics using the 4 methods. For the experimental method, scapulae were reconstructed, and 3 orthogonal global coordinate planes (GCPs) were derived from the medial and lateral borders. Version was measured as the angle between the sagittal reference plane and an anterior-posterior glenoid vector. The intraclass correlation coefficient (ICC) was calculated for the Friedman and corrected Friedman methods. Inconsistencies were assessed for all methods using the interquartile range, mean and standard deviation, and repeated-measures analysis of variance. Concordance correlation coefficients (CCCs) were calculated to assess agreement among the methods. Results: Scapular plane-based methods (experimental, Friedman, and corrected Friedman) yielded an average version between -10° and -12°, with average measurement differences among these methods of <2°. Vault methods (Ganapathi-Iannotti and Matsumura) overestimated or underestimated version by an average of 5° to 7° compared with scapular plane-based methods, and showed significant differences of >12° when compared with each other. Scapular plane-based methods maintained consistency with increasing deformity. Conclusions: The other methods of version measurement using the scapular planes as the reference were highly comparable with the corrected Friedman method. However, when the reference plane was the glenoid vault, version measurements were inconsistent with scapular plane-based methods, which is attributed to differences in the reference systems. In surgical planning, the coordinate system utilized will impact version measurements, which can result in variations in the planned surgical solutions. Additionally, as glenoid deformity increases, this variation resulting from the utilization of different coordinate systems is magnified.

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.

Anatomic shoulder arthroplasty with high side reaming versus reverse shoulder arthroplasty for eccentric glenoid wear patterns with an intact rotator cuff: comparing early versus midterm outcomes with minimum 7 years of follow-up.

BACKGROUND: Eccentric glenoid bone loss patterns (B- and C-type glenoid) pose a difficult challenge when performing shoulder arthroplasty. Anatomic total shoulder arthroplasty with preferential high-side reaming (ATSA + HSR) has been an accepted method to treat this problem. Reverse shoulder arthroplasty (RSA) has become an alternative method to manage these cases with eccentric glenoid wear. The purpose of this study was to compare the early 2-year outcomes with the midterm outcomes for patients who underwent ATSA + HSR vs. RSA for eccentric glenoid wear patterns with an intact rotator cuff. MATERIALS AND METHODS: From 2008 to 2014 there were 242 shoulder arthroplasties performed in the setting of eccentric glenoid wear patterns. Of that initial cohort 101 ATSA + HSR and 93 RSA had both 2-year and final follow-up with a minimum of 7 years from surgery. American Shoulder and Elbow Surgeons (ASES) scores, Simple Shoulder Test (SST), range of motion, patient satisfaction, and radiographs were evaluated for each cohort and contrasted at the 2-year follow-up point and last follow-up time point. RESULTS: The average follow-up in the ATSA + HSR cohort was 8.3 years compared with 7.8 years in the RSA cohort. At the 2-year follow-up point, the ATSA + HSR group had better average ASES scores (85 vs. 80 [P < .001]), SST scores (10 vs. 9.6 [P < .001]), forward elevation (162° vs. 151° [P < .001]), external rotation (47° vs. 42° [P < .001]), and internal rotation (IR) (80% full IR vs. 55% full IR [P < .001]). At the 2-year follow-up, 95% of the ATSA + HSR cohort were satisfied compared with 93% in the RSA cohort. At the final follow-up, the RSA group had better average ASES scores (80 vs. 77 [P < .001]) and SST scores (9.4 vs. 8 [P < .001]) and a similar forward elevation (152° vs. 149° [P = .025]). The ATSA + HSR had better external rotation (45° vs. 41° [P < .001]) and IR (74% full IR vs. 54% full IR [P = .005]). Patient satisfaction at the final follow-up had decreased to 82% in the ATSA + HSR group, compared with 95% satisfied in the RSA group. Of the initial ATSA + HSR cohort, 8% of patients had undergone revision compared with 2% in the RSA cohort. CONCLUSION: ATSA with HSR had better outcome scores and range of motion with a similar patient satisfaction rating to RSA at the 2-year point. Over time, the ATSA + HSR results deteriorated, and at the final midterm follow-up, the RSA group had more durable results with better outcome scores, a higher patient satisfaction rating, and a lower revision rate.

Minimally Invasive Anterior Cruciate Ligament With Quadriceps Tendon Graft: A Proximal-to-Distal Harvest Technique.

Recent systematic reviews have shown anterior cruciate ligament reconstruction using quadriceps tendon (QT) grafts to have superior clinical outcomes compared with traditional bone-patella tendon-bone and hamstring tendons grafts. Using minimally invasive techniques to harvest the QT graft can reduce postoperative pain and intraoperative surgical time. This technique is usually performed with a distal-to-proximal approach but often has issues of inadvertently harvesting a graft short of the desired length or causing a hematoma. As an alternative, we introduce a minimally invasive approach with a proximal-to-distal harvest technique that results in better visualization of tissue planes, more consistent graft sizes, lower risk of inadvertent arthrotomy, and reduced risk of hematoma. The minimally invasive QT graft harvest with a proximal-to-distal approach can offer unique advantages over the current standard distal-to-proximal approach.