Glenoid baseplate orientation in reverse shoulder arthroplasty (RSA) influences clinical outcomes, complications, and failure rates. Novel technologies have been produced to decrease performance heterogeneity of low and high-volume surgeons. This study aimed to determine novice and experienced shoulder surgeon's ability to accurately characterise glenoid component orientation in an intra-operative scenario.

Glenoid baseplates were implanted in eight fresh frozen cadavers by novice surgical trainees. Glenoid baseplate version, inclination, augment rotation, and superior-inferior centre of rotation (COR) offset were then measured using in-person visual assessments by novice and experienced shoulder surgeons immediately after implantation. Glenoid orientation parameters were then measured using 3D CT scans with digitally reconstructed radiographs (DRRs) by two independent observers. Bland-Altman plots were produced to determine the accuracy of glenoid orientation using standard intraoperative assessment compared to postoperative 3D CT scan results.

Visual assessment of glenoid baseplate orientation showed “poor” to “fair” correlation to 3D CT DRR measurements for both novice and experienced surgeon groups for all measured parameters. There was a clinically relevant, large discrepancy between intra-operative visual assessments and 3D CT DRR measurements for all parameters. Errors in visual assessment of up to 19.2 degrees of inclination and 8mm supero-inferior COR offset occurred. Experienced surgeons had greater measurement error than novices for all measured parameters.

Intra-operative measurement errors in glenoid placement may reach unacceptable clinical limits. Kinesthetic input during implantation likely improves orientation understanding and has implications for hands-on learning.

The diagnosis of infection following shoulder arthroplasty is notoriously difficult. The prevalence of prosthetic shoulder infection after arthroplasty ranges from 3.9 – 15.4% and the most common infective organism is Cutibacterium acnes. Current preoperative diagnostic tests fail to provide a reliable means of diagnosis including WBC, ESR, CRP and joint aspiration. Fluoroscopic-guided percutaneous synovial biopsy (PSB) has previously been reported in the context of a pilot study and demonstrated promising results. The purpose of this study was to determine the diagnostic accuracy of percutaneous synovial biopsy compared with open culture results (gold standard).

This was a multicenter prospective cohort study involving four sites and 98 patients who underwent revision shoulder arthroplasty. The cohort was 60% female with a mean age was 65 years (range 36-83 years). Enrollment occurred between June 2014 and November 2021. Pre-operative fluoroscopy-guided synovial biopsies were carried out by musculoskeletal radiologists prior to revision surgery. A minimum of five synovial capsular tissue biopsies were obtained from five separate regions in the shoulder. Revision shoulder arthroplasty was performed by fellowship-trained shoulder surgeons. Intraoperative tissue samples were taken from five regions of the joint capsule during revision surgery.

Of 98 patients who underwent revision surgery, 71 patients underwent both the synovial biopsy and open biopsy at time of revision surgery. Nineteen percent had positive infection based on PSB, and 22% had confirmed culture positive infections based on intra-operative tissue sampling. The diagnostic accuracy of PSB compared with open biopsy results were as follows: sensitivity 0.37 (95%CI 0.13-0.61), specificity 0.81 (95%CI 0.7-0.91), positive predictive value 0.37 (95%CI 0.13 – 0.61), negative predictive value 0.81 (95%CI 0.70-0.91), positive likelihood ratio 1.98 and negative likelihood ratio 0.77.

A patient with a positive pre-operative PSB undergoing revision surgery had an 37% probability of having true positive infection. A patient with a negative pre-operative PSB has an 81% chance of being infection-free. PSB appears to be of value mainly in ruling out the presence of peri-prosthetic infection. However, poor likelihood ratios suggest that other ancillary tests are required in the pre-operative workup of the potentially infected patient.

Our primary objective was to compare healing rates in patients undergoing arthroscopic rotator cuff repair for degenerative tears, with and without bone channeling. Our secondary objectives were to compare disease-specific quality of life and patient reported outcomes as measured by the Western Ontario Rotator Cuff Index (WORC), American Shoulder and Elbow Surgeons (ASES) score and Constant score between groups.

Patients undergoing arthroscopic rotator cuff repair at three sites were randomized to receive either bone channeling augmentation or standard repair. Healing rates were determined by ultrasound at 6 and 24 months post operatively. WORC, ASES, and Constant scores were compared between groups at baseline and at 3, 6, 12 and 24 months post operatively.

One hundred sixty-eight patients were recruited and randomized between 2013 to 2018. Statistically significant improvements occurred in both groups from pre-operative to all time points in all clinical outcome scores (p < 0 .0001). Intention to treat analysis revealed no statistical differences in healing rates between the two interventions at 24 months post-operative. No differences were observed in WORC, ASES or Constant scores at any time-point.

This trial did not demonstrate superiority of intra-operative bone channeling in rotator cuff repair surgery at 24 months post-operative. Healing rates and patient-reported function and quality of life measures were similar between groups.

Tears of the rotator cuff tendons are a very common entity. Despite recent advances in arthroscopic rotator cuff repair, the re-tear rate remains high. Thus, new methods to improve healing rates following rotator cuff repair must be sought. The purpose of this prospective randomized double-blind controlled study is to compare the functional outcomes and healing rates of an adjuvant pre-operative bone microfracture technique prior to arthroscopic cuff repair.

Patients undergoing arthroscopic rotator cuff repair were randomized to receive either a percutaneous bone microfracture of the supraspinatus footprint or a “soft tissue needling” technique, in which the pin was passed through the peripheral edges of the rotator cuff, five-seven days prior to index surgery, under ultrasound guidance. Follow-ups were completed at 3, 6, 12 and 24 months post-operatively. Healing status was determined by ultrasound at 6 and 24 months. The primary objective was to compare the WORC score at 24 months. Secondary objectives included the healing status via ultrasound, the Constant, and the ASES scores. A sample size calculation determined that 90 patients provided 80% power to detect a statistical difference between groups.

Baseline demographic data did not differ between groups. No statistical differences were detected in the WORC outcome at any time points (p=0.47, baseline, p=0.60, 3 months, p=0.79, 6 months, p=0.50, 12 months, p=0.54, 24 months). Healing rates did not differ between groups (P=0.34) and no differences were observed in the ASES or Constant Scores at all time-points. Statistically significant improvements occurred in both groups from baseline to all time points in all clinical outcome scores (p < 0 .0001).

No statistically significant differences in primary or secondary outcomes were identified between pre-operative bone microfracture and soft tissue needling techniques prior to arthroscopic rotator cuff repair. This study does not support pre-operative microfracture as a adjuvant technique prior to arthroscopic cuff repair.

Fractures of the anteromedial facet (AO/OTA 21-B1.1, O'Driscoll Type 2, subtype 3) are associated with varus posteromedial rotational instability of the ulnohumeral joint and early post-traumatic arthritis. The purpose of this study was to examine the stability of plate (locking and non-locking) vs screw constructs in the fixation of anteromedial coronoid facet fractures in a sawbone model.

An anteromedial coronoid facet fracture (AO/OTA 21-B1.1) was simulated in 24 synthetic ulna bones. They were then assigned into 3 fracture fixation groups: non-locking plate fixation, locking plate fixation, and dual cortical screw fixation. An AO 2.0 mm screw and plate system was used for the plate fixation groups and 2.0 mm cortical screws were used for the screw-only group. Following fixation, each construct was potted in bismuth alloy and secured to a servohydraulic load frame. Each construct was cycled in tension and then in compression at 0.5Hz. For both cycling modalities, an incremental loading pattern was used starting at 40 N and increased by 20 N every 200 cycles up to 200N. Fracture fragment displacement was recorded with an optical tracking system. Following cyclic loading each construct was loaded to failure (displacement >2 mm) at 10mm/min.

Tension cycling – All constructs in the plated groups (locking and non-locking constructs) survived the cyclic tension loading protocol (to 200N) with maximum fragment displacement of 12.60um and 14.50um respectively. There was no statistical difference between the plated constructs at any load level. No screw-only fixed construct survived the tension protocol with mean force at failure of 110N (range 60–180N).

Compression Testing – All constructs in the plated groups (locking and non-locking constructs) survived the cyclic compression loading protocol (to 200N), while all but one of the screw-only fixation constructs survived. Fracture fragment displacement was significantly greater in the screw-only repair group across all loading levels when compared to the plated constructs. There was no statistically significant difference in fragment motion between the locking and non-locking groups.

Failure Testing – The maximum load at failure in the screw-only group (281.9 N) was significantly lower than locking and non-locking constructs (587.0 N and 515.5N respectively, p <0.05). There was no difference between the locking and non-locking group in mean load to failure or mean stiffness. Screw construct stiffness (337.2 N/mm) was lower than the locking and non-locking constructs (682.9 N/mm and 479.1 N/mm respectively) however this did not reach statistical significance (p=0.051).

Fixation of anteromedial coronoid fractures is best achieved with a plating technique. Locking plates did not offer any advantage over conventional plates. Isolated screw fixation might not provide adequate stability for these fractures which could result in loss of reduction leading to post-traumatic arthrosis or instabilility.

Purpose

Based on anatomic studies, it appears that the short head (SH) and long head (LH) of the distal biceps tendons have discreet distal attachments on the radial tuberosity. The SH attaches distally and therefore may function as a stronger flexor, whereas the LH attaches more proximal and ulnar which would make it a greater supinator. The contribution of each of the two heads to flexion and supination has not yet been defined. The rationale of this study was to directly measure the contribution of the SH and LH of the biceps to elbow flexion and forearm supination and provide biomechanical evidence for what is inferred in the anatomical studies.

Introduction

We aimed to ascertain the oncological outcome of patients undergoing an amputation for sarcoma in our unit.

A primary mode of failure for total elbow arthroplasty is osteolysis caused by wear debris. Loading of the polyethylene components by off-axis bearing loads is the likely cause of this debris. Load transfer at the elbow is affected by many factors, including the state of the radial head. New implant designs provide the option to use the intact, resected, or implant reconstructed radial head. However, the effect of the radial head state on stability and loading has not yet been investigated in these new implant designs.

We postulated that the presence of the native or prosthetic radial head would reduce the wear-inducing loading patterns experienced by the humeral component and improve joint stability compared to when the radial head is resected.

Seven cadaveric upper extremities, amputated at the mid humerus, were tested in a joint motion simulator equipped with an electromagnetic tracking system to quantify motion. Simulated active flexion was tested with the arm in the dependent position. Passive elbow flexion was conducted with the arm in the varus and valgus gravity-loaded orientations. After testing the intact elbow, the collateral ligaments were sectioned and a linked Latitude ulno-humeral joint replacement was performed (Tornier, Stafford, TX). The humeral component was instrumented with strain gauges for measuring varus-valgus bending and internal-external torsion. Ulno-humeral kinematics and humeral component loading were measured when the radial head was intact, resected, and following radial head arthroplasty.

An increase in varus-valgus laxity was noted following replacement of the ulno-humeral joint with the prosthesis (p< 0.05). There was no difference in joint laxity between the intact radial head, radial head excision or radial head arthroplasty (p> 0.05). Torsion moments increased, while bending loads decreased in the humeral component following radial head excision and were restored following radial head arthroplasty (p< 0.05).

No significant effect of radial head state on varus-valgus joint laxity was observed for the linked ulno-humeral prosthesis. In the absence of collateral ligaments, the observed post-operative increase in varus-valgus laxity can be attributed to the difference in laxity between the native joint and the articular components of the linked implant. Load transfer was altered by radial head excision, which may affect the magnitude of bearing wear and the incidence of aseptic loosening. Further studies are required to determine whether these changes in load transfer influence wear of the polyethylene components or implant loosening.