John G. Costouros

Static posterior humeral head subluxation and total shoulder arthroplasty

BACKGROUND Static posterior subluxation of the humeral head (PSH) is often associated with glenohumeral arthritis. It may persist following total shoulder arthroplasty (TSA) and lead to accelerated polyethylene wear and glenoid component loosening. The factors which lead to PSH are poorly understood. The purpose of this study was to test the hypothesis that operative correction of glenoid version during shoulder arthroplasty re-centers the glenohumeral joint; therefore, glenoid replacement may be considered even in cases of osteoarthritis associated with posterior humeral head subluxation. METHODS Thirty-three of 124 (27%) consecutive shoulders undergoing primary TSA had static preoperative PSH with a subluxation index of at least 65% determined on standardized computer tomographic scans. Twenty-three of these 33 shoulders were available for clinical and computed tomography follow-up after a minimum of 24 and average of 42 months. Mean preoperative glenoid retroversion was -18 [range, 0 degrees - (-40 degrees)], the subluxation index averaged 71% (range, 65-81%). Glenoid morphology, according to Walch et al, was type B1 in 9 patients, type B2 in 5 patients, and type C in 9 patients. A conventional total shoulder replacement was performed through a deltopectoral interval. Using corrective glenoid reaming, restoration of glenoid version to between 0 degrees and 10 degrees of retroversion was attempted in addition to standard soft tissue release. Humeral head retroversion was replicated from the diseased humeral head as closely as possible. RESULTS PSH was reversed in 21/23 patients following TSA with an average final subluxation index of 50% (range, 40-68%; P = .001). There was no significant correlation statistically between PSH and preoperative or postoperative glenoid version, humeral torsion, glenoid morphology, or acromio-humeral distance. Mean absolute Constant scores improved from 39 to 78 points, age-adjusted Constant scores improved from 49% to 95% and subjective shoulder values improved from 40% to 89%, which were all statistically significant (P < .0001). CONCLUSION PSH is frequently present in shoulders with osteoarthritis. It can be corrected in the majority of shoulders undergoing total shoulder replacement; however, re-centering is not correlated with glenoid version or its correction. LEVEL OF EVIDENCE Level 4; Case series, treatment study.

Total shoulder arthroplasty with an uncemented soft-metal-backed glenoid component

BACKGROUND Loosening associated with cemented polyethylene glenoid components is a major concern following total shoulder arthroplasty (TSA). The purpose of this study was to investigate the clinical and radiographic results associated with use of a novel uncemented soft-metal-backed glenoid component (SMBG), with a minimum follow-up of 2 years. MATERIALS AND METHODS Twenty-two patients (19 women) underwent TSA using a uncemented SMBG. The mean age was 68.5 years (range, 49-84). Mean follow-up was 50 months (range, 24-89). Indications for TSA were primary osteoarthritis (10), post-traumatic osteoarthritis (8), steroid-induced avascular necrosis (2), crystalline arthropathy (1), and arthritis secondary to systemic lupus erythematodes (1). Subjective and objective parameters were assessed. Loosening and polyethylene wear were evaluated. RESULTS Mean absolute Constant scores improved from 29.1 to 65.9 points (P < .001), age- and sex-adjusted Constant scores improved from 40.1 to 87.7% (P < .001), and subjective shoulder values improved from 35% to 75.2% (P < .001). Mean pain scores improved from 4.2 points to 13.1 (P < .001). Three cases had a fractured glenoid component. Only these 3 had a definite loosening. Polyethylene wear was found in 2 cases. CONCLUSION Use of an uncemented SMBG component yields controversial results. Osteointegration appears possible and loosening signs have virtually not been observed. Conversely, the current implant can be associated with a high failure rate (13.6%) because of implant fractures despite short follow-up. As loosening seems absent or minimal but implant stability insufficient, design changes need to be performed and tested in view of solving the implant failure problem while preserving the actually excellent bone-implant interface characteristics.

Inhibition of Chondrocyte and Synovial Cell Death After Exposure to Commonly Used Anesthetics Chondrocyte Apoptosis After Anesthetics

Background: An intra-articular injection of local anesthetics is a common procedure for diagnostic and therapeutic purposes. It has been shown that these agents are toxic to articular cartilage and synovial tissue in a dose- and time-dependent fashion, and in some cases, they may lead to postarthroscopic glenohumeral chondrolysis (PAGCL). However, the role of apoptosis in cell death is still unclear, and the potential role of apoptosis inhibition in minimizing chondrocyte and synovial cell death has not been reported. Purpose: (1) To quantify the degree of apoptotic cell death in chondrocytes and synovial cells exposed to local anesthetics, and (2) to determine whether caspase inhibition could reduce cell death. Study Design: Controlled laboratory study. Methods: Human chondrocytes and synovial cells were expanded in vitro and exposed to normal saline, 0.5% bupivacaine, 0.5% ropivacaine, 1% lidocaine, or 1:1000 epinephrine for 90 minutes. Apoptosis was then detected at 1, 3, 5, and 7 days after exposure using terminal deoxynucleotidyl transferase (TdT)–mediated dUTP nick-end labeling (TUNEL) and immunohistochemistry. Apoptosis was then inhibited using the pan-caspase inhibitor z-vad-fmk. Results were normalized to normal saline controls and analyzed by generalized regression models and pairwise confidence intervals. Results: Analysis of cumulative chondrocyte apoptosis relative to controls after anesthetic exposure demonstrated more than 60% cell death with 0.5% bupivacaine and 1:1000 epinephrine. The greatest chondroprotective effect of caspase inhibition occurred with 0.5% ropivacaine. Similarly, in synovial cells, epinephrine was also very cytotoxic; however, 1% lidocaine induced the most apoptosis. Synovial cells exposed to 0.5% ropivacaine were again most sensitive to protective caspase inhibition. Conclusion: Local anesthetics induce chondrocyte and synovial cell apoptosis in a time-dependent fashion, with peak apoptosis occurring 5 days after exposure. Both chondrocytes and synovial cells are most sensitive to caspase inhibition after exposure to 0.5% ropivacaine. Clinical Relevance: Apoptosis inhibition may be an effective strategy in minimizing chondrocyte and synovial cell death after exposure to anesthetics. Further investigation is clinically warranted.

Inhibition of chondrocyte apoptosis in vivo following acute osteochondral injury

In spite of advances and refinements in surgical technique, the development of post-traumatic arthritis following osteochondral injury remains one of the major unsolved problems faced by orthopedic surgeons. Of particular interest is the possibility that chondrocyte programmed cell death (PCD), or ‘apoptosis’, contributes to the subsequent development of post-traumatic arthritis 1–5 . Recent studies have shown that inhibitors of caspases, key enzymes in the apoptosis pathway, can block chondrocyte PCD in vitro 4–7 . The goal of the presented study was to test the hypothesis that short-term, intra-articular caspase inhibitor treatment can limit chondrocyte PCD in vivo following acute osteochondral injury. Adult New Zealand white rabbits underwent experimental osteochondral injury. One group of rabbits received daily intra-articular injections of the broadspectrum caspase inhibitor Z-VAD-fmk. A control group of rabbits received daily intra-articular injections of vehicle alone. After four days of treatment, the articular cartilage was analyzed for chondrocyte PCD. Treatment with Z-VADfmk resulted in a marked reduction in the percentage of chondrocytes undergoing PCD compared to controls [treated=7.4±1.8%; controls=32.5±8.6% (P<0.0001 by student’s t-test)]. The degree of PCD inhibition was dependent upon the distance from the site of injury, with levels of PCD reduced to background levels in areas beyond 1 mm from the drill hole. These results suggest that the intraarticular administration of PCD inhibitors may be a useful strategy for the treatment of osteochondral injury by limiting the extent of articular chondrocyte loss due to apoptosis. For these experiments, a drill with a cooled 2 mm bit was used to create osteochondral injuries in the hind limb femoral condyles of adult rabbits. The injuries were created in the weight bearing portions of the condyles and penetrated into the subchondral bone. Following surgery, five animals received daily intra-articular injections of the caspase inhibitor Z-VAD-fmk (100 µM in 0.1% DMSO, 0.5 cc; Calbiochem, CA) delivered via an indwelling catheter. A control group of five rabbits received daily intra-articular injections of vehicle alone. The knee tissue was harvested on post-injury day 4, decalcified in EDTA, embedded in paraffin, and then sectioned in the sagittal plane at 5 µm thickness for further analysis. Chondrocyte apoptosis was quantified by TUNEL analysis using the ApopTag ® Direct in situ apoptosis detection kit (Intergen, NY) with DAPI used as a counterstain. Fluorescence images were captured using appropriate filters with an Axiocam digital camera (Zeiss, NJ) at 1 megapixel resolution. Each captured field was subdivided into three ‘Zones’ with Zone 1 encompassing the full thickness of articular cartilage extending from 0 to 0.5 mm away from the drill hole; Zone 2 extending from 0.5 to 1 mm away from the drill hole; and Zone 3 extending from 1 to 1.5 mm away from the drill hole (Fig. 1). Semi-automated data collection and analysis were performed using custom

Effect of Perioperative Gabapentin on Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: A Randomized Clinical Trial

Importance Guidelines recommend using gabapentin to decrease postoperative pain and opioid use, but significant variation exists in clinical practice. Objective To determine the effect of perioperative gabapentin on remote postoperative time to pain resolution and opioid cessation. Design, Setting, and Participants A randomized, double-blind, placebo-controlled trial of perioperative gabapentin was conducted at a single-center, tertiary referral teaching hospital. A total of 1805 patients aged 18 to 75 years scheduled for surgery (thoracotomy, video-assisted thoracoscopic surgery, total hip replacement, total knee replacement, mastectomy, breast lumpectomy, hand surgery, carpal tunnel surgery, knee arthroscopy, shoulder arthroplasty, and shoulder arthroscopy) were screened. Participants were enrolled from May 25, 2010, to July 25, 2014, and followed up for 2 years postoperatively. Intention-to-treat analysis was used in evaluation of the findings. Interventions Gabapentin, 1200 mg, preoperatively and 600 mg, 3 times a day postoperatively or active placebo (lorazepam, 0.5 mg) preoperatively followed by inactive placebo postoperatively for 72 hours. Main Outcomes and Measures Primary outcome was time to pain resolution (5 consecutive reports of 0 of 10 possible levels of average pain at the surgical site on the numeric rating scale of pain). Secondary outcomes were time to opioid cessation (5 consecutive reports of no opioid use) and the proportion of participants with continued pain or opioid use at 6 months and 1 year. Results Of 1805 patients screened for enrollment, 1383 were excluded, including 926 who did not meet inclusion criteria and 273 who declined to participate. Overall, 8% of patients randomized were lost to follow-up. A total of 202 patients were randomized to active placebo and 208 patients were randomized to gabapentin in the intention-to-treat analysis (mean [SD] age, 56.7 [11.7] years; 256 (62.4%) women and 154 (37.6%) men). Baseline characteristics of the groups were similar. Perioperative gabapentin did not affect time to pain cessation (hazard ratio [HR], 1.04; 95% CI, 0.82-1.33; P = .73) in the intention-to-treat analysis. However, participants receiving gabapentin had a 24% increase in the rate of opioid cessation after surgery (HR, 1.24; 95% CI, 1.00-1.54; P = .05). No significant differences were noted in the number of adverse events as well as the rate of medication discontinuation due to sedation or dizziness (placebo, 42 of 202 [20.8%]; gabapentin, 52 of 208 [25.0%]). Conclusions and Relevance Perioperative administration of gabapentin had no effect on postoperative pain resolution, but it had a modest effect on promoting opioid cessation after surgery. The routine use of perioperative gabapentin may be warranted to promote opioid cessation and prevent chronic opioid use. Optimal dosing and timing of perioperative gabapentin in the context of specific operations to decrease opioid use should be addressed in further research. Trial Registration clinicaltrials.gov Identifier: NCT01067144

Instability after reverse total shoulder arthroplasty

BACKGROUND This study evaluated patients with and without a prosthetic dislocation after reverse total shoulder arthroplasty (RTSA) to identify risk factors for instability. METHODS Dislocation and nondislocation cohorts were established for analysis in 119 patients who had undergone RTSA at our institution between 2011 and 2014. Preoperative history and parameters pertaining to RTSA design were evaluated for correlation with instability. A logistic regression model was used to analyze independent predictors. RESULTS Eleven patients (9.2%) demonstrated instability in the early postoperative period. Dislocations occurred at an average of 8 weeks postoperatively (range, 3 days-5 months). The mean follow-up of all patients was 28 months (range, 6-106 months). Postoperative instability was associated with male gender, history of prior open shoulder surgery, and preoperative diagnoses of fracture sequelae, particularly proximal humeral or tuberosity nonunion. Absence of subscapularis repair was an independent predictor of instability. In addition, 5 of the 11 patients (45%) in the instability cohort sustained a second dislocation requiring another operation. CONCLUSIONS Redislocation after revision surgery for the initial dislocation was an unexpected and alarming finding. Treatment for the initial dislocation event by placement of a thicker polyethylene insert was inadequate in 45% of patients of our cohort and required another revision with a larger glenosphere and thicker humeral inserts. Initial instability after RTSA must be carefully managed, especially in the revision and post-traumatic setting. Exchange to a thicker polyethylene insert only carries a higher risk of recurrent instability.

Simultaneous bilateral resection total shoulder arthroplasty with anatomic antibiotic cement spacer retention

Periprosthetic shoulder infection (PSI) is a challenging problem that may lead to shoulder pain, dysfunction, and even death. The reported incidence of infection after shoulder arthroplasty ranges from 0% to 4%.7,14,16 Recent developments have improved our ability to diagnose and to treat this condition. To date, there is no consensus on the optimal treatment of patients with PSI. To our knowledge, no reports of simultaneous bilateral resection total shoulder arthroplasty (TSA) and cement spacer placement exist in the literature. We report one such case with a 25-month follow-up.

Is Ultrasound Guidance Needed for Shoulder Injections

MJ is a 44-year-old teacher who has had right lateral shoulder pain for 5 weeks. The pain developed acutely after he played a pickup game of basketball. He initially presented to his primary care physician, who suspected an acute rotator cuff injury and prescribed naproxen, 500 mg twice daily, along with physical therapy. MJ has completed 4 weeks of appropriate therapy focusing on scapular retraction exercise, pectoralis stretching, and rotator cuff strengthening. He experienced no relief from the therapy or medication, so his primary care physician obtained a shoulder magnetic resonance (MR) arthrogram, which demonstrated thickening of the subacromial-subdeltoid bursa, suggestive of bursitis, and a type I superior labral anterior to posterior (SLAP) lesion. MJ was sent to you for further evaluation and treatment. He currently has a 7 out of 10 level of pain over the anterolateral shoulder that is worse when he performs overhead maneuvers and sleeps on his right side. Upon physical examination he has no tenderness to palpation but experiences pain during active range of motion testing, particularly with internal rotation and abduction, respectively. He also has a positive Hawkins-Kennedy test, Neer sign, and O’Brien test. He has difficulty deciding whether his characteristic pain is reproduced more by the impingement maneuvers or labral maneuver. Neurovascularly, he is intact. You discuss treatment options, and given the failure of conservative treatments thus far, he wishes to pursue a corticosteroid injection in the subacromial bursa. He recently saw a commercial on TV featuring an injection that was performed with ultrasound guidance and asks if ultrasound guidance should be used to perform his injection. Dr Jonathan Finnoff will argue that ultrasound guidance should be used for the injection, and Dr John Costouros will argue that ultrasound guidance is not needed.