Lindsay R. Miller

Arthroscopic Tissue Culture for the Evaluation of Periprosthetic Shoulder Infection

BACKGROUND Periprosthetic shoulder infections can be difficult to diagnose. The purpose of this study was to investigate the utility of arthroscopic tissue culture for the diagnosis of infection following shoulder arthroplasty. Our hypothesis was that culture of arthroscopic biopsy tissue is a more reliable method than fluoroscopically guided shoulder aspiration for diagnosing such infection. METHODS A retrospective review identified patients who had undergone culture of arthroscopic biopsy tissue during the evaluation of a possible chronic periprosthetic shoulder infection. The culture results of the arthroscopic biopsies were compared with those of fluoroscopically guided glenohumeral aspiration and open tissue biopsy samples obtained at the time of revision surgery. RESULTS Nineteen patients had undergone arthroscopic biopsy to evaluate a painful shoulder arthroplasty for infection. All subsequently underwent revision surgery, and 41% of those with culture results at that time had a positive result, which included Propionibacterium acnes in each case. All arthroscopic biopsy culture results were consistent with the culture results obtained during the revision surgery, yielding 100% sensitivity, specificity, positive predictive value, and negative predictive value. In contrast, fluoroscopically guided glenohumeral aspiration yielded a sensitivity of 16.7%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 58.3%. CONCLUSIONS Arthroscopic tissue biopsy is a reliable method for diagnosing periprosthetic shoulder infection and identifying the causative organism. LEVEL OF EVIDENCE Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Conversion to Reverse Shoulder Arthroplasty: Humeral Stem Retention Versus Revision.

As the volume of shoulder arthroplasty procedures performed in the United States continues to increase, the predicted number of revision shoulder arthroplasties grows even higher. Conversion of failed shoulder arthroplasty to reverse total shoulder arthroplasty has become common. Many commercially available shoulder arthroplasty systems now offer a platform humeral stem that is used for both anatomic shoulder arthroplasty and reverse total shoulder arthroplasty. This study investigated whether retaining the humeral stem offers advantages over revising the humeral stem in conversion of failed shoulder arthroplasty to reverse total shoulder arthroplasty. The study included 26 patients (mean age, 68.46 years) with failed shoulder arthroplasty who underwent conversion to reverse total shoulder arthroplasty with a minimum 2-year follow-up (mean, 34.38 months). Patients who had retention of the humeral stem were compared with those who had stem revision. Humeral stem retention was associated with a significantly shorter operative time (178.92 vs 237 minutes, P=.02). Decreases in blood loss, complications, and length of hospitalization were observed, but the differences were not statistically significant. Minimal differences were observed for patient-reported outcomes. Of patients undergoing humeral stem removal, 21.4% had an intraoperative humeral shaft or tuberosity fracture compared with none in the stem retention group. Humeral stem retention was associated with decreased operative time compared with humeral stem revision in the conversion of failed shoulder arthroplasty to reverse total shoulder arthroplasty. The use of a platform shoulder arthroplasty system may benefit patients with failed shoulder arthroplasty undergoing conversion to reverse total shoulder arthroplasty by avoiding humeral stem revision.

Glenoid version and its relationship to glenohumeral instability and labral tears

BACKGROUND Evidence suggests a relationship between glenoid retroversion and posterior instability, but no literature exists comparing glenoid version referencing the scapular body versus the endosteal vault. This study evaluated glenoid version and its relationship to unidirectional instability and labral tears. METHODS Glenoid version in patients with unidirectional instability or labral tears was measured with magnetic resonance imaging by either the Friedman method or the Poon and Ting method. Analyses of variance followed by independent t tests were used to compare 3 groups: anterior instability or labral tears (anterior pathology group, n = 33); posterior instability or labral tears (posterior pathology group, n = 34); and stable controls (n = 30). The referencing error for 2-dimensional axial images was evaluated for variance by imaging facility. Interobserver and intraobserver reliability scores were calculated. RESULTS With the Friedman method, the posterior pathology group (-9°) was more retroverted than the control group (-4°) (P = .0005) and the anterior pathology group (-5°) (P = .0104) but there was no difference between the control group and anterior pathology group (P = .38). The referencing error in the sagittal plane averaged 23° and varied by facility (P = .0365). The coronal-plane error averaged 1° and did not vary by facility (P = .7180). Intraclass correlation coefficient scores showed good to excellent intrarater and inter-rater reliability. CONCLUSION The posterior pathology group had 5° more retroversion than controls using the Friedman method. Glenoid version using the Poon and Ting method or the Friedman method did not predict anterior instability or labral tears. Axial magnetic resonance images were constructed with a referencing error in the sagittal plane that varied by magnetic resonance imaging facility and has implications for improving 2-dimensional axial imaging protocols.

Imaging characteristics of lesser tuberosity osteotomy after total shoulder replacement: a study of 220 patients

BACKGROUND The lesser tuberosity osteotomy (LTO) has been gaining popularity as a method of exposing the glenohumeral joint during total shoulder replacement, whereby a small fragment of bone is removed from the lesser tuberosity, thus preserving the subscapularis tendon. To date, no large, randomized studies have reported evaluations of LTO healing and healing rates. METHODS We reviewed the radiographs and available computed tomography images of 362 patients who underwent a total shoulder arthroplasty by the same surgeon between 2006 and 2012. The integrity of the LTO site was graded as not seen, bony union, nondisplaced nonunion, and displaced nonunion. The smoking status of patients was also assessed. RESULTS Of 362 patients investigated, 220 had a minimum of 6 months of radiographic follow-up. The LTO site was not seen in 37 patients; of the remaining 183, 159 patients (86.89%) demonstrated bony union, 8.80% of whom were smokers; 16 patients (8.74%) demonstrated nondisplaced nonunion, 6.3% of whom were smokers; and 8 patients (4.3%) demonstrated displaced nonunion, 25.0% of whom were smokers. Overall, 19 of the 24 nonunions were in male patients (79.1%) and 5 were in female patients (20.8%). CONCLUSIONS This is the first large-scale study to report the healing rate of LTOs. LTO healing is best assessed on radiographs; if nondisplaced or displaced nonunions are suspected, computed tomography can be a helpful additional examination. The number of radiographs where there is a lack of adequate visualization of the LTO site raises important questions about definitive radiographic evaluation using current techniques.

Transtendon, Double-Row, Transosseous-Equivalent Arthroscopic Repair of Partial-Thickness, Articular-Surface Rotator Cuff Tears

Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patients remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears. Direct visualization of the reduction of the retracted articular tendon layer to its insertion on the greater tuberosity is the key to the procedure. Linking the medial-row anchors and using a double-row construct provide a stable repair that allows early shoulder motion to minimize the risk of postoperative stiffness.

Long Head of the Biceps Tendon Allis Clamp Evaluation Technique

Disorders of the long head of the biceps brachii are a common finding in conjunction with other causes of shoulder pathology. Nonoperative means as first-line treatment are often successful; however, surgery can be indicated for refractory tendinopathy. There is debate as to the best surgical treatment of the long head of the biceps tendon (LHBT) with different types of arthroscopic and open techniques. The decision on what treatment option to perform is often made at the time of surgery after arthroscopic evaluation of the LHBT. Certain examples of tendon disease are easily visible intra-articularly; however, a large portion of the tendon is not intra-articular and not readily viewed during routine arthroscopy. This study describes a simple arthroscopic technique for evaluation of an increased portion of the LHBT using an Allis clamp. The clamp is inserted through the anterior portal, placed around the LHBT, and rotated such that the tendon is wrapped around itself, bringing the distal tendon into the joint for arthroscopic viewing. This procedure is a routine part of our assessment of the LHBT during arthroscopy.

Value and Reverse Total Shoulder Arthroplasty: The Boston Shoulder Institute Perspective

Healthcare delivery is undergoing a fundamental shift from traditional fee-for-service reimbursement toward a system focused on the creation of patient-centric value. Orthopedic surgeons will face increasing pressure to justify therapeutic interventions through expected improvements of clinical outcomes at lower costs. Consequently, increasing useof the reverse total shoulder arthroplasty in this environment necessitates a critical analysis of its economic value.