Robert A. Sershon

Biomechanical Evaluation of Transosseous Rotator Cuff Repair Do Anchors Really Matter

Background: Suture anchor fixation has become the preferred method for arthroscopic repairs of rotator cuff tears. Recently, newer arthroscopic repair techniques including transosseous-equivalent repairs with anchors or arthroscopic transosseous suture passage have been developed. Purpose: To compare the initial biomechanical performance including ultimate load to failure and localized cyclic elongation between transosseous-equivalent repair with anchors (TOE), traditional transosseous repair with a curved bone tunnel (TO), and an arthroscopic transosseous repair technique utilizing a simple (AT) or X-box suture configuration (ATX). Study Design: Controlled laboratory study. Methods: Twenty-eight human cadaveric shoulders were dissected to create an isolated supraspinatus tear and randomized into 1 of 4 repair groups (TOE, TO, AT, ATX). Tensile testing was conducted to simulate the anatomic position of the supraspinatus with the arm in 60° of abduction and involved an initial preload, cyclic loading, and pull to failure. Localized elongation during testing was measured using optical tracking. Data were statistically assessed using analysis of variance with a Tukey post hoc test for multiple comparisons. Results: The TOE repair demonstrated a significantly higher mean ± SD failure load (558.4 ± 122.9 N) compared with the TO (325.3 ± 79.9 N), AT (291.7 ± 57.9 N), and ATX (388.5 ± 92.6 N) repairs (P < .05). There was also a significantly larger amount of first-cycle excursion in the AT group (8.19 ± 1.85 mm) compared with the TOE group (5.10 ± 0.89 mm). There was no significant difference between repair groups in stiffness during maximum load to failure or in normalized cyclic elongation. Failure modes were as follows: TOE, tendon (n = 4) and bone (n = 3); TO, suture (n = 6) and bone (n = 1); AT, tendon (n = 2) and bone (n = 3) and suture (n = 1); ATX, tendon (n = 7). Conclusion: This study demonstrates that anchorless repair techniques using transosseous sutures result in significantly lower failure loads than a repair model utilizing anchors in a TOE construct. Clinical Relevance: Suture anchor repair appears to offer superior biomechanical properties to transosseous repairs regardless of tunnel or suture configuration.

Incidence, Risk Factors, and Sources of Sepsis Following Total Joint Arthroplasty

BACKGROUND Sepsis is a rare but serious complication following total joint arthroplasty (TJA). Common sources include urinary tract infection (UTI), surgical site infection (SSI), and pneumonia. The purpose of this study is to characterize the incidence, risk factors, and sources of sepsis following TJA. METHODS Patients undergoing primary total hip arthroplasty or total knee arthroplasty during 2005-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Independent associations were tested for using multivariate regression adjusting for baseline characteristics. RESULTS A total of 117,935 patients were identified (45,612 undergoing total hip arthroplasty and 72,323 undergoing total knee arthroplasty). Of these, 402 (0.34%) developed sepsis following surgery. Patients who developed sepsis had an elevated mortality rate (3.7% vs 0.1%, P < .001). Among the 402 patients who developed sepsis, 124 (31%) had concomitant UTI, 110 (27%) SSI, and 60 (15%) pneumonia. Twenty-one patients (5%) had multiple infectious sources and 129 patients (32%) had no identifiable source. Independent risk factors for sepsis included greater age, male sex, functional dependence, insulin-dependent diabetes, hypertension, chronic obstructive pulmonary disease, current smoker, and greater operative time. CONCLUSION These findings suggest that the rate of sepsis following TJA is about 1 in 300, and that sepsis is associated with a high risk of mortality. The most common sources of sepsis are UTI, SSI, and pneumonia, potentially accounting for at least two-thirds of cases. The information provided here can be used to guide the diagnostic workup of sepsis in patients following TJA.

Treatment of Osteonecrosis of the Talus

More than 60% of the talar surface area consists of articular cartilage, thereby limiting the possible locations for vascular infiltration and leaving the talus vulnerable to osteonecrosis.Treatment strategies for talar osteonecrosis can be grouped into four categories: nonsurgical, surgical-joint sparing, surgical-salvage, and joint-sacrificing treatments. Nonoperative and joint-sparing treatments include restricted weight-bearing, patellar tendon-bearing braces, bone-grafting, extracorporeal shock wave therapy, internal implantation of a bone stimulator, core decompression, and vascularized or non-vascularized autograft, whereas joint-sacrificing or salvage procedures include talar replacement (partial or total) and arthrodesis.In patients with a Ficat and Arlet grade-I through III osteonecrosis, evidence in favor of a specific treatment is poor, although tibiotalar or tibiotalocalcaneal arthrodesis may represent a suitable salvage operation.

Current indications for hip resurfacing arthroplasty in 2016

Hip resurfacing arthroplasty (HRA) is an alternative to conventional, stemmed total hip arthroplasty (THA). The best reported results are young, active patients with good bone stock and a diagnosis of osteoarthritis. Since the 1990s, metal-on-metal (MoM) HRA has achieved excellent outcomes when used in the appropriate patient population. Concerns regarding the metal-on-metal bearing surface including adverse local tissue reaction (ALTR) to metal debris have recently lead to a decline in the use of this construct. The current paper aims to provide an updated review on HRA, including a critical review of the most recent literature on HRA.

Low accuracy of interpretation of rotator cuff MRI in patients with osteoarthritis

Background Magnetic resonance imaging (MRI) is considered to be a valuable tool for the diagnosis of rotator cuff tears in patients with severe glenohumeral osteoarthritis who are indicated for total shoulder arthroplasty (TSA). We determined the sensitivity, specificity, and positive predictive value of MRI in diagnosing rotator cuff tears in such patients. Methods MRI reports of 100 patients who had completed a shoulder MRI prior to TSA were reviewed to determine the radiologists’ interpretation of the MRI including the diagnosis, presence of a full-thickness cuff tear, and the presence of atrophy and/or fatty infiltration within the rotator cuff muscle bellies. Operative reports were used as a gold standard to determine whether a full-thickness rotator cuff tear was present. Results Preoperative MRI reports noted 33 of the 100 patients as having a full-thickness rotator cuff tear, 17 of which had multiple tendon tears. 2 of the 33 patients with full tears on MRI were found to have full-thickness tears at surgery. The sensitivity, specificity, and positive predictive value for MRI detection of full-thickness tears were 100%, 68%, and 6% respectively, with a false-positive rate of 32% and an accuracy of 69%. Interpretation The study suggests that although MRI is highly sensitive, it has a low positive predictive value and moderately low specificity and accuracy in detecting full-thickness rotator cuff tears in patients with severe glenohumeral osteoarthritis.

Radial head replacement with a bipolar system: an average 10-year follow-up

BACKGROUND We report the long-term results of a cohort of patients after radial head replacement with a bipolar design and a smooth cementless stem at a mean follow-up of 10.4 years. METHODS Of 17 possible patients from a previous minimum 2-year follow-up study, 16 were available for review. Patients were assessed using clinical and radiographic examination and with standardized outcome measures. Range of motion, stability, and radiographic evaluation of implant loosening and joint degeneration were assessed. Comparisons were performed using the Wilcoxon signed rank test for unequal groups. RESULTS The average follow-up was 10.5 years (range, 8.5-12 years). The median visual analog scale was 1 (range, 0-5), Minnesota Elbow Performance Index was 93 (range, 70-100), and the Disabilities of the Arm, Shoulder and Hand was 7.5 (range, 0-53). Range of motion was decreased on the operative side compared with the nonoperative side for flexion/extension (P = .005) and pronation/supination (P = .015). Grip strength was decreased on the affected side (P = .045). No patients had elbow instability. Significant arthritic changes developed in 2 patients at the ulnohumeral joint. The median cantilever quotient was 0.4 (range, 0.30-0.50). Osteolysis in zones 1 to 7 was found in all but 2 patients. The median stem radiolucency was 0.5 mm (range, 0.2-0.9 mm). No reoperations occurred since our previous report. Implant survival in this cohort was 97%. CONCLUSION Bipolar radial head prosthesis with a smooth cementless stem effectively restores elbow stability and function after comminuted radial head fractures with or without concomitant elbow instability. Our study demonstrates excellent long-term implant survival.

Incidence, Risk Factors, and Clinical Implications of Pneumonia After Surgery for Geriatric Hip Fracture

BACKGROUND Little is known regarding the occurrence of pneumonia after hip fracture surgery. The purpose of this study is to determine the incidence, risk factors, and clinical implications of pneumonia after surgery for geriatric hip fracture. METHODS The American College of Surgeons National Surgical Quality Improvement Program was used to retrospectively study geriatric patients undergoing surgery for hip fracture during 2006-2014. Independent risk factors for developing pneumonia within 30 days of surgery were identified using multivariate regression. RESULTS Of the 29,377 patients meeting inclusion criteria, 13,736 (46.8%) underwent hemiarthroplasty, 9468 (32.2%) intramedullary fixation, 4294 (14.6%) plate and/or screw fixation, 1299 (4.4%) total joint arthroplasty, and 580 (2.0%) percutaneous fixation. In total 1191 patients developed pneumonia, an incidence of 4.1%. The strongest risk factors for pneumonia were male sex, older age (especially ≥90 years), low body mass index, and chronic obstructive pulmonary disease. Patients who developed pneumonia had a higher readmission rate (79.1% vs 8.2%, P < .001), a higher rate of sepsis (16.6% vs 1.7%, P < .001), and a higher mortality rate (29.2% vs 5.7%, P < .001). Among 1602 total mortalities, 348 (17.9%) occurred in patients with pneumonia. CONCLUSION Pneumonia is a serious complication after geriatric hip fracture surgery, which increases the readmission and mortality risks. Evidence-based pneumonia prevention programs should be implemented among high-risk patients-males, patients ≥90 years, body mass index <18.5 kg/m2, and/or patients with chronic obstructive pulmonary disease-to decrease morbidity and mortality.

Does Greater Body Mass Index Increase the Risk for Revision Procedures Following a Single-Level Minimally Invasive Lumbar Discectomy?

Study Design. Retrospective analysis of a prospectively maintained surgical registry. Objective. To examine the association between body mass index (BMI) and the risk for undergoing a revision procedure following a single-level minimally invasive (MIS) lumbar discectomy (LD). Summary of Background Data. Studies conflict as to whether greater BMI contributes to recurrent herniation and the need for revision procedures following LD. Patients and surgeons would benefit from knowing whether greater BMI is a risk factor to guide the decision whether to pursue an operative versus non-operative treatment. Methods. Patients undergoing a single-level MIS LD were retrospectively identified in our institutions prospectively maintained surgical registry. BMI was categorized as normal weight (<25 kg/m2), overweight (25–30 kg/m2), obese (30–40 kg/m2), or morbidly obese (≥40 kg/m2). Multivariate analysis was used to test for association with undergoing a revision procedure during the first 2 postoperative years. The model was demographics, comorbidities, and operative level. Results. A total of 226 patients were identified. Of these, 56 (24.8%) were normal weight, 80 (35.4%) were overweight, 66 (29.2%) were obese, and 24 (10.6%) were morbidly obese. A total of 23 patients (10.2%) underwent a revision procedure in the first 2 postoperative years. The 2-year risk for revision procedure was 1.8% for normal weight patients, 12.5% for overweight patients, 9.1% for obese patients, and 25.0% for morbidly obese patients. In the multivariate-adjusted analysis model, BMI category was independently associated with undergoing a revision procedure (P = 0.038). Conclusion. These findings indicate that greater BMI is an independent risk factor for undergoing a revision procedure following a LD. These findings conflict with recent studies that have found no difference between obese and non-obese patients in regards to risk for recurrent herniation and/or revision procedures. Patients with greater BMI undergoing LD should be informed they could have an elevated risk for revision procedures. Level of Evidence: 4

Classifying femoral bone deficiency: Picking the right tool for the job

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in preoperative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. We have developed a classification of femoral deficiency and an algorithmic approach to femoral reconstruction is presented.Type I: Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision.Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component.Type IIIA: The metaphysis is severely dam...

The Role of the Superior Labrum Following Biceps Tenodesis in Glenohumeral Kinematics and Stability (SS-07)

Introduction At the present time, little is known about the role a torn superior labrum plays in glenohumeral (GH) kinematics and stability following biceps tenodesis (BT). The current biomechanical study evaluated the contribution a type II SLAP lesion has on GH translation in the presence of a BT, asking two questions: Does a type II SLAP tear require fixation following BT, and if so, which of two repair techniques is superior? Methods Baseline GH translation data was collected from 15 intact cadaveric shoulders using a custom shoulder testing apparatus. Anterior (n=5) and posterior (n=10) type II SLAP tears were created, and translation testing was repeated. BT was then performed for each specimen, with re-evaluation of translation post-procedure. Finally, repair of the type II SLAP lesion was performed utilizing one of two suture anchor constructs for the posterior SLAP (two single-loaded vs. one double-loaded anchor) and one suture anchor construct for the anterior SLAP (two single-loaded anchors), followed by repeat translation testing. Comparisons were made between the translation data for each group. Results Both anterior and posterior type II SLAP lesions led to increases in anterior and posterior GH translation compared to baseline. In the presence of a posterior SLAP lesion, anterior and posterior translation increased significantly to 85.7% (5.2mm to 9.6mm) and 54.8% (5.4mm to 8.4mm), respectively. Anterior SLAP lesions led to a significant increase in anterior translation of 72.8% (4.3mm to 7.5mm) and a 37.8% non-significant increase in posterior translation (7.1mm to 9.8mm). BT for both types of SLAP improved translation stability, reducing anterior translation in the presence of a posterior tear from 9.6mm to 7.7mm and posterior translation in the presence of an anterior tear from 9.8mm to 8.0mm, although these values were not significant. For anatomic repair with either 2 single-loaded anchors or 1 double-loaded anchor, posterior SLAP repair improved anterior translation to 0.0% and 22.1% of baseline, respectively. For anterior tears, anatomic repair led to a posterior translation 11.6% of baseline. All repairs did not differ significantly from baseline. Conclusion Biceps tenodesis shows no deleterious effect on glenohumeral kinematics and stability in the presence of a SLAP lesion. Thus, BT can be a useful revision procedure for patients with persistent pain following SLAP repair. Additionally, no significance was found between the two repair constructs.