Effect of Bone Coverage on Acetabular Implant Stresses in Standard and Dual-Mobility Total Hip Arthroplasty Constructs: A Finite Element Model.

Although mechanical stress in total hip arthroplasty modular head-neck junctions is thought to contribute to the risk of trunnionosis and related metal ion disease in total hip arthroplasty, little is known about mechanical stress in the modular acetabular components. Recent retrieval analyses of dual-mobility constructs have demonstrated corrosion between liner and shell in some dual-mobility acetabular components. The objective of this study was to evaluate acetabular stress as a function of acetabular bone coverage, component modularity, and femoral head diameter. A parametric finite element model was created. The acetabulum was set at 40° of abduction and 15° of anteversion; superolateral bone loss up to 50° was modeled; and 28-mm, 32-mm, 36-mm, and 40-mm head sizes were simulated in stance phase of gait. Fixed polyethylene-bearing, monoblock and modular dual-mobility (MDM) acetabular components were evaluated. For traditional fixed-bearing components, the largest peak stress, 49.5 MPa, was observed with 50° of bone loss and a 28-mm head. The lowest peak stress, 6.3 MPa, occurred with complete bone coverage and a 36-mm head. Peak stress in the MDM construct, 25.1 MPa, concentrated in the chromium-cobalt portion of the construct. Larger head diameters are associated with decreased stress in the acetabular component when bone loss is present. An MDM construct with a stiff inner liner may decrease overall stress in the acetabular construct, but focally increased stress near the rim of uncovered acetabular components may increase the risk of metal-on-metal corrosion. [Orthopedics. 2021;44(5):280-284.].

Increased Load to Failure in Biceps Tenodesis With All-Suture Suture Anchor Compared With Interference Screw: A Cadaveric Biomechanical Study.

PURPOSE: To compare the biomechanical characteristics of a single radially expanding all-suture anchor with an interference screw for open subpectoral long head of biceps tendon (LHBT) tenodesis. METHODS: Eighteen fresh-frozen matched-pair human cadaveric humeri were used for this biomechanical study. The matched pair humeri were randomly assigned into 2 experimental biceps tenodesis groups: conventional interference screw (CIS) or all-suture suture anchor (ASSA). Open subpectoral LHBT tenodesis was then performed and biomechanical testing was performed using a servohydraulic test frame. A preload of 5 N was applied for 2 minutes before cyclic loading. Displacement was recorded at cycle 300 (D300) and cycle 500 (D500) and at ultimate failure. Data recorded included displacement, load to failure, displacement at failure. Paired t test was used for analysis. RESULTS: Decreased displacement was observed for the CIS group at D300 (1.67 ± 0.57 mm vs 3.35 ± 2.24 mm; P = .04), D500 (2.00 ± 0.76 mm vs 3.87 ± 2.20 mm; P = .04), and at failure (5.17 ± 3.05 mm vs 10.76 ± 2.66 mm; P < .001). Load to failure was lower in CIS specimens (170 ± 24.5 N vs 217.8 ± 51.54 N; P = .02). Failure in each case was tendon pullout for all CIS specimens; in ASSA 6 specimens failed as the suture pulled through the tendon, 2 specimens failed by suture breakage. No difference in stiffness was observed between the 2 groups (CIS = 98.33 ± 22.98 N/m vs ASSA = 75.94 ± 44.83 N/m; P = .20). CONCLUSIONS: Our study found that open subpectoral biceps tenodesis performed with an ASSA construct results in increased load to failure as compared with CIS. However, the CIS did demonstrate decreased displacement as compared to ASSA in this cadaveric biomechanical study. CLINICAL RELEVANCE: ASSA and CIS at time zero provide fixation as indicated by the provider intraoperatively for LHBT tenodesis. ASSA, however, does remove less cortical bone than does CIS and therefore produces a smaller stress riser in the proximal humerus. Further testing as to the integrity of ASSA is warranted to determine the integrity of the tenodesis with cyclical loading.

Zoledronic Acid Improves Muscle Function in Healthy Mice Treated with Chemotherapy.

Carboplatin is a chemotherapy drug used to treat solid tumors but also causes bone loss and muscle atrophy and weakness. Bone loss contributes to muscle weakness through bone-muscle crosstalk, which is prevented with the bisphosphonate zoledronic acid (ZA). We treated mice with carboplatin in the presence or absence of ZA to assess the impact of bone resorption on muscle. Carboplatin caused loss of body weight, muscle mass, and bone mass, and also led to muscle weakness as early as 7 days after treatment. Mice treated with carboplatin and ZA lost body weight and muscle mass but did not lose bone mass. In addition, muscle function in mice treated with ZA was similar to control animals. We also used the anti-TGFß antibody (1D11) to prevent carboplatin-induced bone loss and showed similar results to ZA-treated mice. We found that atrogin-1 mRNA expression was increased in muscle from mice treated with carboplatin, which explained muscle atrophy. In mice treated with carboplatin for 1 or 3 days, we did not observe any bone or muscle loss, or muscle weakness. In addition, reduced caloric intake in the carboplatin treated mice did not cause loss of bone or muscle mass, or muscle weakness. Our results show that blocking carboplatin-induced bone resorption is sufficient to prevent skeletal muscle weakness and suggests another benefit to bone therapy beyond bone in patients receiving chemotherapy. © 2019 American Society for Bone and Mineral Research.

Epidemiology of Surgical Treatment of Adolescent Sports Injuries in the United States: Analysis of the MarketScan Commercial Claims and Encounters Database.

PURPOSE: To determine whether there is increasing surgical management of adolescent sports injuries and whether the average age of surgical patients is decreasing. METHODS: The Truven Health MarketScan Database was searched from 2008 to 2014 for patients 10 to 19 years of age using the International Classification of Disease, 9th Revision codes and Current Procedure Terminology, 4th Edition, codes for operative treatment for the following conditions: anterior cruciate ligament (ACL) injuries, knee collateral ligament (KCL) injuries, meniscal injuries, Osgood-Schlatter syndrome, and elbow ulnar collateral ligament injuries. Patients identified were characterized by sex, age, year of injury, and type of residence (urban vs rural) based on metropolitan statistical areas. RESULTS: A total of 516,892 patients sustained 1 of the identified injuries, and 133,541 (25.8%) patients underwent a related surgery. KCL and meniscal injuries demonstrated a consistent increase in the rate of surgical intervention (P < .0001). Average age of surgical intervention did not increase or decrease overall for any diagnosis. Female adolescents were more likely to undergo surgery for KCL injuries (adjusted odds ratio [aOR] 1.7, 95% confidence interval [CI] 1.58-1.79, P < .0001), Osgood-Schlatter syndrome (aOR 1.8, 95% CI 1.38-2.39, P < .0001), and ACL injuries (aOR 1.5, 95% CI 1.45-1.52, P < .0001), whereas male adolescents were more likely to undergo surgery for meniscal injuries (aOR 1.3, 95% CI 1.24-1.30, P < .0001) and ulnar collateral ligament injuries (aOR 1.1, 95% CI 1.06-1.23, P < .0005). Patients in rural areas were more likely to undergo surgical intervention for ACL and meniscal injuries (P < .0001) and KCL injuries (P = .02). CONCLUSIONS: We found that surgical treatment of 5 common sports injuries remains stable, with only KCL injuries and meniscal injuries showing an increase in surgical incidence. Average age of surgical intervention did not change significantly over the 7-year time span for any diagnosis. LEVEL OF EVIDENCE: Level IV, Cross Sectional Study.

Surgical Trends in Articular Cartilage Injuries of the Knee, Analysis of the Truven Health MarketScan Commercial Claims Database from 2005-2014.

PURPOSE: To evaluate trends in procedures for the treatment of chondral injuries of the knee using the MarketScan database in the hope that further work can be performed to refine the indications for chondral intervention. METHODS: The MarketScan Research Database was searched using Current Procedure Terminology, 4th edition, codes to identify patients who underwent chondral procedures of the knee from 2005-2014. Combined procedures, including meniscal transplant or osteotomy, were also identified. Patients were characterized by gender, age group and year of initial procedure. A χ2 test was used to evaluate differences in surgical trends between individual patient groups delineated by age and gender. The Cochran-Armitage trend test was used to identify significant differences in surgical trends yearly. RESULTS: Of 148,373,254 unique patients, 520,934 patients underwent a total of 599,119 procedures. Arthroscopy with debridement/shaving of articular cartilage decreased in proportion from 75% of all procedures in 2005 to 51% of all procedures in 2014 (P < .0001). Open osteochondral allograft saw the greatest change during the study period; a higher number of females than males underwent condral procedures (P < .0001). Patients aged 45-54 underwent the most procedures (32.9% of all procedures). A total of 483 patients underwent chondral procedures in conjunction with meniscal transplant with variable incidence during the study period. A total of 1,418 patients underwent chondral procedures in conjunction with osteotomy; cumulative incidence decreased from 4.5 procedures per 1,000,000 patients/year in 2005 to 2.6 procedures per 1,000,000 patients/year in 2014 (P < .0001). CONCLUSIONS: Knee arthroscopy with debridement/shaving of articular cartilage remains the most common procedure performed. Although open allograft and autograft transplantation saw a sustained increase in incidence, the overall incidence of cartilage procedures, as well as those performed with osteotomies, declined. LEVEL OF EVIDENCE: Level IV, cross-sectional study.

Saucerization Versus Complete Resection of a Symptomatic Discoid Lateral Meniscus at Short- and Long-term Follow-up: A Systematic Review.

PURPOSE: To evaluate the surgical outcomes of symptomatic discoid menisci after total meniscectomy, saucerization, and suture repair of tears of a discoid meniscus at short- and long-term follow-up. METHODS: A systematic review was conducted using the Pubmed and ScienceDirect databases in adherence with Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines. Short- and long-term follow-up were defined as an average follow-up of <4 years and >4 years, respectively. Pooled quantitative synthesis was performed on studies that reported results of total meniscectomy and saucerization in the same study. A systematic review was performed on studies that reported data on saucerization, total meniscectomy, and/or repair. RESULTS: A total of 19 studies for the short term and 22 for the long term were identified that met inclusion criteria for qualitative review. Of these, 4 short-term and 5 long-term studies were included in the quantitative synthesis. No significant differences in Ikeuchi scores are seen in the short-term studies between saucerization and total meniscectomy; however, the long-term studies did find a statistical difference favoring saucerization (P < .001). The differences noted between the preoperative and postoperative Lysholm scores in the short term were 24.1 (95% conflict of interest: 10.25-37.95) in 3 studies and 22.38 (95% conflict of interest: 17.68-27.07) in the 4 long-term studies for saucerization. Suture repair with saucerization versus saucerization without suture repair revealed a statistical difference in only 1 of 5 studies. CONCLUSIONS: Long-term data demonstrate significantly improved patient reported outcomes in favor of saucerization over total meniscectomy. Suture repair of tears of a lateral discoid meniscus does not demonstrate improved outcomes over partial meniscectomy without repair. Considering the cost of repair and lack of demonstrated improvement, based on the limited available data, we do not recommend repair of the abnormal anatomy in a torn lateral discoid meniscus. LEVEL OF EVIDENCE: Level IV, systematic review.

Patient Outcomes as a Function of Shoulder Surgeon Volume: A Systematic Review.

PURPOSE: To examine surgical complications, length of stay, surgical time, cost, revision rates, clinical outcomes, current surgical trends. and minimum number of cases in relationship to surgeon volume for shoulder arthroplasty and rotator cuff repair. METHODS: We performed a systematic review of studies using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies that met inclusion criteria from January 1990 to January 2016 were included. Inclusion criteria included Level IV evidence or greater, contained specific surgeon volume, and were written in or translated into English. Exclusion criteria included non-English manuscripts, abstracts, and review papers. A written protocol was used to extract relevant data and evaluate study results. Data extracted included volume-specific data pertaining to length of stay, operating time, complications, and cost. RESULTS: A total of 10 studies were included. Seven studies evaluated arthroplasty with 88,740 shoulders, and 3 studies evaluated rotator cuff repair with 63,535 shoulders. Variation was seen in how studies defined low- versus high-volume surgeon. For arthroplasty, <5 cases per year met the criteria for a low-volume surgeon and were associated with increased length of stay, longer operating room time, increased in-hospital complications, and increased cost. Mortality was not significantly increased. In rotator cuff surgery, <12 surgeries per year met the criteria for low volume and were associated with increased length of stay, increased operating room time, and increase in reoperation rate. CONCLUSIONS: Our systematic review demonstrates increased surgical complications, length of stay, surgical time, and surgical cost in shoulder arthroplasty and rotator cuff repair when performed by a low-volume shoulder surgeon, which is defined by those performing <5 arthroplasties and/or <12 rotator cuff repairs per year. LEVEL OF EVIDENCE: Level III, systematic review of Level II and III studies.

The Effect of the Pucker Sign on Outcomes of Type III Extension Supracondylar Fractures in Children.

BACKGROUND: The pucker sign, also called skin tenting, indicates significant displacement of the supracondylar fracture and can be a cause for alarm. The purpose of this study is to compare a cohort of patients with type III supracondylar fractures presenting with a pucker sign to a group without a pucker sign by evaluating neurovascular injury at presentation, need for open reduction, persistent neurovascular injury, range of motion, and carrying angle at final follow-up. METHODS: A retrospective review was performed for Gartland type III extension type supracondylar fractures. Those with a pucker sign were identified and evaluated. Type III supracondylar fractures with a pucker sign were compared with a similar cohort without a pucker sign. RESULTS: In total, 12 patients with a pucker sign at an average age of 5.2 years were evaluated. A total of 11 patients (92%) had diminished or absent pulses, and 2 (17%) had weakness in the median nerve distribution. Nine (75%) patients in this group were transferred to the university hospital. Average time to surgery was 8.9 hours with an average operating time of 25.1 minutes. Open reduction was not needed in any case. At an average follow-up of 4.7 months no patients had persistent neurovascular compromise. Two patients lacked <5 degrees of extension and 1 lacked 10 degrees of extension. One patient lacked 10 degrees of flexion. No patients had a change in carrying angle difference compared with the contralateral side. No statistical differences were observed between the 2 groups. CONCLUSIONS: Pucker sign, in the context of a supracondylar fracture of the humerus, is a soft tissue defect with potential entrapment of median nerve and brachial artery. At a maximum time of 16 hours from injury to surgery we report excellent outcomes and no long-term complications. Using the techniques of gradual traction, and milking the soft tissue, the pucker sign can be eliminated. Closed reduction and percutaneous pinning were performed in all the cases. LEVEL OF EVIDENCE: Level III-retrospective comparative study.