Biomechanical characteristics of subscapularis-sparing approach for anatomic total shoulder arthroplasty.

BACKGROUND: A technique for retaining the superior 50% of the subscapularis insertion for anatomic total shoulder arthroplasty has been described. This cadaveric study biomechanically evaluates this subscapularis-sparing approach and compares it with a complete subscapularis release and repair technique to determine whether there is a higher load to failure. MATERIALS AND METHODS: Twelve matched pairs of human cadaveric arms were distributed into 3 test groups. Group 1 consisted of specimens with and without a 100% subscapularis release. Group 2 consisted of specimens with and without an inferior 50% subscapularis release. Group 3 consisted of specimens with either an inferior 50% or 100% release of the subscapularis footprint and repair. All tendon repairs were performed using bone tunnels and sutures. Specimens were biomechanically tested using non-destructive cyclic and tensile failure-inducing loads. RESULTS: In matched pairs, the following comparative results were obtained: native intact subscapularis specimens exhibited a load to failure of 1341.20 ± 380.10 N compared with 380.10 ± 138.79 N in the 100% release specimens (P = .029), native intact subscapularis specimens exhibited a load to failure of 1209.74 ± 342.18 N compared with 744.33 ± 211.77 N in the 50% release specimens (P = .057), and 50% release and repair specimens exhibited a load to failure of 704.62 ± 165.53 N compared with 305.52 ± 91.39 N in the 100% release and repair group (P = .029). CONCLUSION: Preservation of the superior 50% of the subscapularis demonstrates a higher load to failure compared with complete subscapularis release and repair using bone tunnels.

Meniscal Allograft Transplantation: Does Surgical Technique Influence Clinical Outcomes?

PURPOSE OF REVIEW: Meniscal allograft transplantation is intended to address painful knees with symptoms that can be attributed to meniscal deficiency through injury or meniscectomy. Initially viewed as an experimental procedure, refinements in patient selection and surgical technique have led to improved clinical outcomes with wider acceptance. Our intention with this paper is to provide a review of meniscal allograft transplantation, with the focus on the different surgical techniques employed and their influence on outcomes. RECENT FINDINGS: The main debate regarding surgical technique is using bone or only soft tissue for fixation of the meniscal horns. Biomechanical and other basic science studies show improved function and less extrusion when the grafts are secured with bone. However, several clinical studies show no difference in outcomes. Long-term studies have shown improved success with less graft extrusion and may illustrate the important function of bone fixation. Many clinical studies, including those with long-term outcomes, have shown meniscal allografts can decrease patient pain and improve function. It is a technically challenging procedure with good clinical outcomes regardless of the method of graft fixation. Bone fixation provides less extrusion which is associated with improved graft function and decreased rate of joint deterioration. Further study is needed to determine if other methods to decrease extrusion are able to improve graft function and outcomes.

Report of Missed Non-Hodgkin's Lymphoma Presenting as Pathological Tibial Fracture.

Pathological fractures usually occur in patients with known malignancies, though pathological fracture may be the first sign of cancer. Malignant pathological fractures most commonly represent metastatic lung, breast, kidney, thyroid, or prostate cancer and typically occur in the spine, pelvis, femur, and humerus. We present the case of a 71-year-old female with an atraumatic tibial fracture in which further imaging was not pursued. Five months later, she was diagnosed with non-Hodgkin's lymphoma. Pathological proximal tibial fracture is an exceedingly rare presentation of lymphoma; however, diagnostic delay could likely have been avoided if a thorough workup had been pursued. Our case highlights the importance of careful examination of all patients presenting with a low-energy fracture, particularly when constitutional symptoms suggestive of cancer are present. All patients with pathological fractures should receive a thorough physical examination that includes lymph node palpation.

Steroid Injection and Open Trigger Finger Release Outcomes: A Retrospective Review of 999 Digits.

Background: Open surgical release of the A1 pulley is the definitive treatment for the common hand condition of trigger finger, or inflammatory stenosing tenosynovitis. Anecdotal evidence among hand surgeons has questioned whether or not recent steroid injection may be related to complications following open trigger finger release, particularly wound infection, but no studies have primarily studied this connection to date. We aimed to determine whether recent steroid injection was associated with postoperative surgical infections. Methods: We performed a retrospective chart review of 780 adult patients who had undergone open trigger finger release of 999 digits by 6 fellowship-trained hand surgeons at three affiliated hospital settings from January 1, 2014, to January 1, 2016. Data on timing of steroid injections relative to surgery, number of steroid injections, concomitant conditions, use of antibiotics, and postoperative complications including infections were gathered. Results: Steroid injection timing relative to subsequent operative intervention correlated with postoperative surgical site infection in trigger finger release. Older age and decreasing days between steroid injection and surgery correlated with infection rates. Other factors found to be associated with infection rates included smoking, use of preoperative antibiotics, and use of lidocaine with epinephrine. The other factors examined did not correlate with infection rates. Conclusions: Steroid injection, smoking, increasing age, lesser number of days between steroid injection and surgery, and use of lidocaine with epinephrine are risk factors for postoperative trigger surgical infections. We recommend careful preoperative counseling regarding higher wound healing risks for smokers, avoidance of steroid injections immediately prior to an operative date, and scheduling operative dates that tend to be greater than 80 days from the date of last steroid injection. We also recommend avoidance of epinephrine in the local anesthetic solution, as this may minimize surgical site infection risks.

Safety and Accuracy of Core Needle Biopsy for Soft Tissue Masses in an Ambulatory Setting.

BACKGROUND: Percutaneous needle biopsy has been found to be a safe and accurate method for the initial investigation of soft tissue masses. The notion exists that needle biopsies should be performed in specialized sarcoma centers, which can place a financial burden on patients without a sarcoma center near their place of residence. There is no consensus in the current literature regarding the diagnostic accuracy and clinical utility of clinic-based percutaneous core needle biopsy performed by community orthopedic surgeons with fellowship training in musculoskeletal oncology. QUESTIONS/PURPOSES: Our primary goal was to determine if office-based core needle biopsy of soft tissue masses could safely yield accurate diagnoses when performed by a community orthopedic surgeon with fellowship training in musculoskeletal oncology. PATIENTS AND METHODS: We retrospectively reviewed the charts of 105 patients who underwent percutaneous core needle biopsy of soft tissue masses in a community clinic. All procedures were performed by one fellowship-trained musculoskeletal oncologist. Accuracy of the initial clinic-based needle biopsy was determined through comparison to the results of pathological analysis of the surgically excised masses. Final data analysis included 69 patients who underwent both clinic-based biopsy and subsequent surgical excision of their masses. RESULTS: We found clinic-based biopsies to be 87.0% accurate for exact diagnosis and 94.2% accurate in determining whether the mass was benign or malignant (p < 0.0001). Minor complications related to the clinic-based biopsy occurred in 5.80% of cases, with no documentation of major complications. CONCLUSIONS: Our results provide evidence that office-based percutaneous biopsy can be administered safely and yield accurate, clinically useful results when performed by a fellowship-trained musculoskeletal oncologist.

Comparing the Efficacy of the Total Stabilizing and Posterior Stabilizing Knee Prostheses in Obese and Preobese Females: A Retrospective Cohort Study.

Obesity is associated with increased surgical complications that may lead to suboptimal total knee arthroplasty (TKA) outcomes. Additionally, females exhibit increased rates of severe, clinical osteoarthritis OA, along with increased ligamentous laxity. Therefore, obese females present a particularly challenging case for TKA with increased joint loads coupled with a propensity for instability. This study retrospectively analyzed knee range of motion and stability of one TKA designs with two different degrees of polyethylene conformity in the obese female population. The implants (Stryker Triathlon total stabilizing [TS] and Stryker Triathlon posterior stabilizing [PS]) differ in their level of constraint, with the TS being more constrained. We hypothesized that the TS implants would be associated with improved functional outcomes in the obese female population, secondary to increased coronal stability to offset the ligamentous laxity. Of 482 knees reviewed, 173 met the inclusion criteria of: female, body mass index (BMI) ≥ 25, receiving TS (N = 93), or PS (N = 8). Primary knee outcome measures were: active flexion, passive flexion, active extension, passive extension, and stability at 0° and 30° flexion. These factors were statistically analyzed at preop, 2-week, 6-week, 3-month, and 1-year time points. Preoperatively, the TS cohort was significantly higher in BMI and knee laxity, potentially starting this cohort at a functional disadvantage. Postoperatively, the TS implant was associated with a statistically significant early improvement in active and passive knee extension. There was no longer any significant difference in knee laxity postop. Our data support the hypothesis that obese females may benefit from the increased stability afforded by the TS design.

Biomechanical Analysis of Superior and Anterior Precontoured Plate Fixation Techniques for Neer Type II-A Clavicle Fractures.

OBJECTIVE: There are limited biomechanical data supporting the use of anterior or superior-lateral precontoured clavicle plates for the treatment of displaced Neer type II-A clavicle fractures. The objectives of this study were as follows: (a) compare noncontoured versus precontoured superior plating; (b) compare use of locking versus nonlocking screws in the lateral fragment for superior precontoured plates; and (c) compare superior versus anterior precontoured plates with locking lateral fragment screws. METHODS: The following constructs were tested on a synthetic clavicle model simulating a Neer type II-A fracture: (a) superior precontoured plate with locking (SUP-L, n = 6); (b) superior precontoured plate with nonlocking (SUP-NL, n = 8); (c) anterior precontoured plate with locking (ANT-L, n = 7); and (d) superior noncontoured locking compression plate (SUP-LCP, n = 6). Constructs were subjected to cyclical cantilever loads. Construct stiffness and survival (cycles to failure) were documented. Mann-Whitney U tests were performed for group-wise statistical comparison (α = 0.05) of data. RESULTS: The SUP-L construct was significantly stiffer than both SUP-LCP and ANT-L constructs (P < 0.02). The SUP-NL construct was stiffer than the SUP-L (P = 0.03) construct. Both SUP-L and ANT-L precontoured constructs survived longer than the noncontoured SUP-LCP construct (P < 0.022). The SUP-L construct survived longer than the SUP-NL (P = 0.013) and the ANT-L (P = 0.008) constructs. CONCLUSIONS: Superior precontoured plates yielded biomechanically superior constructs compared with anterior precontoured and superior noncontoured plates. Using locking screws in the lateral fragment over nonlocking screws may improve overall superior precontoured plate construct survivability. However, our results were limited to a synthetic biomechanical model and require further investigation to establish a clinical correlation.

Role of Subscapularis Repair on Muscle Force Requirements with Reverse Shoulder Arthroplasty.

Concomitant repair of the subscapularis with reverse shoulder arthroplasty (rTSA) is controversial. To evaluate the biomechanical impact of subscapularis repair with rTSA, a cadaveric shoulder controller quantified the muscle forces required to elevate the arm during scapular abduction with the elbow flexed at 90°. The results of this study demonstrate that concomitant subscapularis repair with rTSA creates a biomechanically unfavorable condition during arm elevation. Specifically, repair of the subscapularis significantly increased the force required by the deltoid and posterior rotator cuff and also significantly increased the joint reaction force relative to when the subscapularis was not repaired. These results also demonstrated that both the 42 mm Grammont and 42 mm Equinoxe® rTSA prostheses significantly decreased the mean force required by the posterior rotator cuff and also significantly decreased the mean joint reaction force over the range of motion relative to the native joint with a rotator cuff tear (supraspinatus). As the posterior rotator cuff is often compromised in patients undergoing rTSA, patients may not be able to sustain these elevated forces in the infraspinatus and teres minor required to counteract the adduction and internal rotation moments generated by the subscapularis during activities of daily living. Similarly, the elevated posterior deltoid force and joint reaction loads could be deleterious to the long-term life of the prosthesis and can also increase the risk of loosening and fractures. For all these reasons, rTSA functional outcomes may be compromised if the subscapularis is repaired.