Faculty Bibliography

Recent case studies of surface oxidized zirconium THA heads removed after attempted, closed reduction have shown significant surface damage that has been suggested as potentially deleterious to polyethylene wear. We obtained 4 clinically retrieved specimens, produced well-characterized surface damage on additional heads, and tested them on a hip simulator. After 1 million cycles, the amount of polyethylene wear was related to the extent of surface damage, the most damaged clinical specimen showing more than 50 times more wear than a new head. Although all heads after failed attempted closed reduction(s) should be replaced, surface oxidized zirconium heads are of particular concern; those patients with a successful, simple closed reduction should be monitored for excessive wear

Total shoulder arthroplasty is a common treatment for glenohumeral arthritis. One of the most common failure modes of total shoulder arthroplasty is glenoid loosening, causing postoperative pain, limitation of function, and potentially, the need for revision surgery. The literature has devoted considerable attention to the design of the glenoid component; efforts to better understand the biomechanics of the reconstructed glenohumeral joint and identify factors that contribute to glenoid component loosening are ongoing. This article reviews the current state of knowledge about the glenoid in total shoulder arthroplasty, summarizing the anatomic parameters of the intact glenoid, variations in component design and fixation, the mechanisms of glenoid loosening, the outcomes of revision surgery in the treatment of glenoid component failure, and alternative treatments for younger patients

PURPOSE: To evaluate what effect the angle of screw-in suture anchor insertion has on fixation stability at the suture-tendon interface. METHODS: Supraspinatus tendons from 7 matched pairs of human cadaveric shoulders were split, yielding 4 tendons per cadaver. An experimental rotator cuff tear was created and repaired, using a 5.0-mm diameter screw-in suture anchor. In a staggered, matched pair arrangement, the angle of anchor insertion was varied between 45 degrees (deadman's angle) and 90 degrees to the articular surface. Each repair underwent cyclic loading, and 2 failure points were defined: the first at 3 mm of repair site gap formation and the second at the point of complete failure. The number of cycles to failure was compared between the 2 groups. RESULTS: The mean number of cycles to 3-mm gap formation for anchors inserted at 90 degrees was 380. This was significantly higher than for repairs made with the 45 degrees angle of anchor insertion (mean, 297 cycles). Complete failure occurred at a significantly greater number of cycles with the 90 degrees anchors (mean, 443 cycles) compared with the 45 degrees anchors (mean, 334 cycles). CONCLUSIONS: Compared with anchors placed at the current standard of the deadman's angle of 45 degrees, suture anchors placed at 90 degrees to the junction of the greater tuberosity and the humeral head articular surface provided improved soft tissue fixation in an experimental rotator cuff model. CLINICAL RELEVANCE: The angle of suture anchor insertion into the greater tuberosity during rotator cuff repair has an effect on the soft tissue fixation at the tendon-suture interface

Geriatric hip fracture management requires a specialized treatment algorithm secondary to the complex medical and social needs of this patient demographic. The overall goal of the treatment is early mobilization, in an effort to prevent the complications associated with prolonged recumbency and to return the patient to functional activity. There is near-universal agreement among orthopedic surgeons that fractures about the hip require operative fixation, but surgical management in this patient population brings with it a set of issues that require important consideration. The current article reviews the perioperative considerations associated with geriatric hip fractures and takes an evidence-based look at the complex issues involved in managing these patients

BACKGROUND: Although the exact mechanism of action has yet to be elucidated, recent animal studies have demonstrated chondroprotective and anti-inflammatory properties of hyaluronic acid viscosupplementation. HYPOTHESIS: Intra-articular hyaluronic acid after microfracture improves the quality of the repair leading to a more hyaline-like repair tissue with better defect fill and adjacent area integration. STUDY DESIGN: Controlled laboratory study. METHODS: Full-thickness cartilage defects were created in the weightbearing area of the medial femoral condyle in 36 female New Zealand White rabbits. The defects were then treated with surgical microfracture. Eighteen rabbits formed the 3-month cohort and the other 18 formed the 6-month cohort. Within each cohort, 6 rabbits were randomly assigned to receive 3 weekly injections of hyaluronic acid (group A), 5 weekly injections (group B), or control injections of normal saline (group C). At 3 and 6 months postmicrofracture, the animals were sacrificed and the operative knee harvested. Repair tissue was assessed blinded- both grossly, using a modified component of the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment scoring scale, and histologically, using the modified O'Driscoll histological cartilage scoring system. Comparisons were made with respect to gross and histologic findings between treatment groups at each time point. Effects of each treatment type were also evaluated longitudinally by comparing the 3-month results with the 6-month results. Statistical analysis was performed using unpaired Student t tests with significance defined as P < .05. RESULTS: At 3 months, gross and histologic evaluation of the repair tissue demonstrated that the 3-injection group had significantly better fill of the defects and more normal appearing, hyaline-like tissue than controls (a mean ICRS score of 1.92 vs 1.26; P < .05 and a mean modified O'Driscoll score of 10.3 vs 7.6; P < .02). Specimens treated with 5 weekly injections were not significantly improved compared with controls. At 6 months, the mean gross appearance and histologic scores between the 3 specimen cohorts were not significantly different. However, examination of the entire operative knee demonstrated a significantly greater extent of degenerative changes (synovial inflammation and osteophyte formation) in the control group than in both hyaluronic acid treatment groups (P < .05). CONCLUSION: Supplementing the microfracture technique with 3 weekly injections of intra-articular hyaluronic acid had a positive effect on the repair tissue that formed within the chondral defect at the early follow-up time point. This improvement was not found for the 3-injection group at 6 months or for the 5-injection group at either time point. Additionally, hyaluronic acid supplementation had a possible chondroprotective and anti-inflammatory effect, limiting the development of degenerative changes within the knee joint. CLINICAL RELEVANCE: The adjunctive use of hyaluronic acid appears to hold promise in the treatment of chondral injuries and warrants further investigation

Intra-articular hyaluronic acid viscosupplementation is gaining popularity as a treatment option in the nonoperative management of patients with osteoarthritis. Recent clinical studies have demonstrated that the anti-inflammatory, anabolic, and chondroprotective actions of hyaluronic acid reduce pain and improve patient function. With evidence mounting in support of the efficacy of this treatment modality for patients with osteoarthritis, its potential use in additional patient populations and for other pathologies affecting the knee is being investigated. The current article reviews the use of intra-articular hyaluronic acid viscosupplementation in the management of knee osteoarthritis and presents the potential for expanding its indications for other joints and alternative patient subpopulations. Additionally, future directions for the use of hyaluronic acid and areas of active research are discussed

BACKGROUND: The Bio-Transfix pin is a biodegradable device used for femoral tunnel anterior cruciate ligament (ACL) graft fixation. Recent clinical studies have suggested the possibility of the pin's postoperative failure. METHODS: This investigation evaluates the initial strength of several Bio-Transfix pin ACL fixations in a simulated femoral tunnel model. The forces generated by five surgeons during simulated ACL graft tensioning were also measured. RESULTS: Average strengths of the pins ranged from 1075 to 2160 N for 10 and 8 mm tunnels, respectively, whereas the maximum surgeon-generated forces were 535 N. CONCLUSIONS: These results imply that initial fracture of the pin itself is unlikely; however, failure of the supporting bone or a decrease in pin strength due to biodegradation could account for early loss of the fixation

PURPOSE: To prospectively compare the efficacy of 2-octylcyanoacrylate (Dermabond; Ethicon Inc, Somerville, NJ) with standard suture repair in the management of nail bed lacerations. METHODS: Forty consecutive patients with acute nail bed lacerations were enrolled in this study. Eighteen patients were randomized to nail bed repair using Dermabond (2-octylcyanoacrylate), and 22 were randomized to standard repair using 6-0 chromic suture. At presentation, demographic information and laceration characteristics were recorded. The time required for nail bed laceration repair with each method was documented, and cosmetic and functional outcomes were assessed at 1, 3, and 6 months after injury. Comparisons between treatment groups were made using unpaired Student's t-tests. RESULTS: The Dermabond repair group was composed of 10 males and 8 females with a mean age of 32.3 years. The suture repair group was composed of 17 males and 5 females with a mean age of 29.5 years. The mean follow-up was 5.1 months (range 4-11 months) and 4.8 months (range 4-11 months) for the Dermabond group and suture group, respectively. There was no difference between the two treatment groups with respect to age, comorbidities, and length of follow-up (p>.05). The average time required for nail bed repair using Dermabond was 9.5 minutes, which was significantly less than that required for suture repair (27.8 minutes) (p<.0003). At each follow-up time point, there was no statistical difference in physician-judged cosmesis, patient-perceived cosmetic outcome, pain, or functional ability between the Dermabond and suture treatment cohorts (p>.05). CONCLUSIONS: Nail bed repair performed using Dermabond is significantly faster than suture repair, and it provides similar cosmetic and functional results. In the management of acute nail bed lacerations, Dermabond is an efficient and effective repair technique. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic I

PURPOSE: To compare the stability of a novel, nonspanning external fixator with a standard volar locked plate for treatment of unstable distal radius fractures. METHODS: A simulated, unstable, extra- articular distal radius fracture was created in six matched pairs of fresh frozen human distal radii. One of each pair was treated with a nonspanning external fixator [Mirza Cross Pin Fixator (CPX), A.M. Surgical Inc. Smithtown, NY] and the other was treated with a volar locked plate [Distal Volar Radial Plate (DVR), Hand Innovations, Miami, FL]. Each specimen was axially loaded in central, dorsal, and volar locations, loaded in cantilever bending in volar to dorsal, dorsal to volar, and radial to ulnar directions and loaded in torsion. Load-displacement curves were generated to determine the construct stiffness for each loading schema, with comparisons made between the two treatment groups. Specimens were then cyclically loaded with 50 N axial loads applied for 1,000 and 10,000 cycles. Measurement of construct stiffness was repeated and comparisons made both between the two treatments and within treatments to their precycling stiffness. RESULTS: There was no significant difference in the mechanical stiffness of the nonspanning external fixator and the volar locking plate after axial loading in any of the loading modalities.Cyclic loads of 1,000 and 10,000 cycles resulted in no significant difference in construct stiffness between the nonspanning external fixator and volar locked plate. However, the nonspanning external fixator demonstrated decreasing stiffness after cyclic loading with 10,000 cycles (p < 0.02). CONCLUSION: This study demonstrated no significant difference in the mechanical stiffness of the CPX nonspanning external fixator and volar locked plate in a cadaveric fracture model. Both constructs appear to be biomechanically equivalent in this experimental model; however, this is only one factor in the choice of fixation device for the management of unstable distal radius fractures

Psoriatic arthritis is a complex, chronic inflammatory disease with both skin and joint involvement. Clinical presentation varies considerably among patients and during the course of the disease. Assessment of patients for psoriatic arthritis requires careful attention to patient history, a focused physical examination, and inspection for characteristic radiographic changes. Although this disease was once thought to be a rare and mild form of arthritis, recent studies have shown that patients with psoriatic arthritis may develop significant disability, with up to 20% of cases demonstrating a rapidly progressive, debilitating clinical course. Orthopedic manifestations of the disease can be severe and can cause significant physical disability. Although surgical intervention for psoriatic arthritis is relatively uncommon, having an understanding of the assessment, available treatment options, and surgical considerations allows for improved outcome in the management of this complex patient population