Patient-specific versus conventional instrumentation for total knee arthroplasty: peri-operative and cost differences.

The role of patient-specific instrumentation in total knee arthroplasty (TKA) is yet to be clearly defined. Current evidence evaluating peri-operative and cost differences against conventional TKA is unclear. We reviewed 356 TKAs between July 2008 and April 2013; 306 TKAs used patient-specific instrumentation while 50 had conventional instrumentation. The patient-specific instrumentation cohort averaged 20.4 min less surgical time (P < 0.01) and had a 42% decrease in operating room turnover time (P = 0.022). At our institution, the money saved through increased operating room efficiency offset the cost of the custom cutting blocks and pre-operative advanced imaging. Routine use of patient-specific TKA can be performed with less surgical time, no increase in peri-operative morbidity, and at no increased cost when compared to conventional TKA.

Popliteal artery injury associated with total knee arthroplasty: trends, costs and risk factors.

Popliteal artery injury is a relatively rare but potentially devastating complication of total knee arthroplasty (TKA). We analyzed the Nationwide Inpatient Sample from 1998 to 2009 to determine the actual incidence, risk factors and consequences of this complication. There were 1,120,508 hospitalizations coded for TKA; of these, 633 (0.057%) were identified as having a popliteal artery injury. The rate of injury remained relatively constant though the number of both TKAs and injuries have risen annually by 0.65% and 0.5%, respectively. Significant risk factors included revision surgery, peripheral vascular disease, weight loss, renal failure, coagulopathy, and metastatic cancer. Consequences were increased hospital charges, length of stay, and mortality rates. Because the rate of popliteal artery injury is not diminishing with time and morbidity and mortality are high, patients should be assessed for known risk factors for popliteal artery injury.

Femoroacetabular impingement: treatment of the acetabular side.

Over the past decade, femoroacetabular impingement (FAI) has become an increasingly recognized pathomechanism that may explain why some hips that were previously considered to have normal morphology fail early in life. Subtle morphologic alterations in the acetabulum or femur, as well as the degree of hypermobility or impact on the hip, affect the potential for joint damage. The most frequent location of FAI is the anterosuperior acetabular rim, and the most critical motion is internal rotation of the hip in flexion. Because medication, activity restrictions, and physical therapy are rarely successful in treating symptoms caused by FAI, surgery has become a mainstay of treatment. Acetabular causes of FAI, called pincer FAI, can be treated by improving hip clearance. Independent of whether local or global overcoverage is present, rim reduction should be combined with labral preservation whenever possible.

Extended retinacular soft-tissue flap for intra-articular hip surgery: surgical technique, indications, and results of application.

Osteotomies of the proximal femur for hip joint conditions are normally done at the intertrochanteric or subtrochanteric level. Intra-articular osteotomies would be more direct and therefore allow a more powerful correction with no or very little undesired side correction. However, concerns about the risk of vascular damage and osteonecrosis of the femoral head have so far basically excluded this technique from practical use. Based on detailed knowledge of the vascular anatomy of the proximal femur, an approach to safely dislocate the femoral head has been described and successfully performed. Experience as well as further studies of femoral head perfusion allowed a substantial extension of this approach, with subperiosteal exposure of the circumference of the femoral neck with constant intraoperative control of the blood supply to the head. Using the extended retinacular soft-tissue flap, four surgical techniques (relative neck lengthening, subcapital realignment in slipped capital femoral epiphysis, true femoral neck osteotomy, and femoral head reduction osteotomy) evolved or became safer with respect to perfusion of the femoral head. The extended retinacular soft-tissue flap offers the technical and biologic possibility for a new class of intra articular procedures. Although meticulous execution of the surgical steps is important, the procedures have a high level of safety for femoral head perfusion.

Alleviation of Cartilage Destruction by Sinapic Acid in Experimental Osteoarthritis.

Sinapic acid (SA) modulates the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in chondrocytes. In order to test the hypothesis that SA is protective against the development of osteoarthritis (OA), primary mouse chondrocytes were treated in vitro with SA and the promoter transactivation activity of heme oxygenase 1 (HO-1), nuclear translocation of Nrf2, and protein expression of HO-1 were assayed. To test the hypothesis in vivo, a destabilization of the medial meniscus (DMM) model was used to induce OA in the knees of mice and SA was delivered orally to the experimental group. The chondrocytes were harvested for further analysis. The expression of HO-1 was similarly upregulated in cartilage from both the experimental mice and human chondrocytes from osteoarthritic knees. SA was found to enhance the promoter transactivation activity of heme oxygenase 1 (HO-1) and increase the expression of Nrf2 and HO-1 in primary chondrocytes. Histopathologic scores showed that the damage induced by the DMM model was significantly lower in the SA treatment group. The addition of a HO-1 inhibitor with SA did not show additional benefit over SA alone in terms of cartilage degradation or histopathologic scores. The expression of TNF-α, IL-1ß, IL-6, MMP-1, MMP-3, MMP-13, ADAMTS4, and ADAMTS5 was significantly reduced both in vitro and in vivo by the presence of SA. Protein expressions of HO-1 and Nrf2 were substantially increased in knee cartilage of mice that received oral SA. Our results suggest that SA should be further explored as a preventative treatment for OA.

Corrigendum to "Delayed diagnosis of catastrophic ceramic liner failure with resultant pelvic discontinuity and massive metallosis" [ARTD 3 (2017) 77-82].

[This corrects the article DOI: 10.1016/j.artd.2016.11.002.].

Delayed diagnosis of catastrophic ceramic liner failure with resultant pelvic discontinuity and massive metallosis.

With newer-generation ceramic components used in total hip arthroplasty, component fracture is a rare complication. However rare, when ceramic component fracture does occur, prompt identification and revision is necessary as delay can lead to dramatic failure with resultant metallosis as the extremely hard ceramic debris abrades remaining components. We present a case of a 70-year-old woman with ceramic liner fracture and an estimated 10-year delay in intervention with failure resulting in pelvic discontinuity and massive metallosis with associated cutaneous manifestation. She was treated with a complex revision and reconstruction and is 2 years postrevision without major complication.

Staged total hip arthroplasty in a patient with hip dysplasia and a large pertrochanteric bone cyst.

Hip arthroplasty in young patients requires thoughtful preoperative planning. Patients with proximal femoral bone loss complicate this planning and may require a staged procedure to optimize implant insertion. We report on a case of a 26-year-old woman with secondary hip arthritis from developmental dysplasia of the hip and a large pertrochanteric bone cyst that was treated with staged total hip arthroplasty. The cyst was decompressed and filled with an osteoconductive and osteoinductive bone graft substitute called EquivaBone. One year later, the patient underwent a successful primary total hip arthroplasty. Fifteen-month follow-up after her hip replacement revealed resolution of postoperative pain and significant functional improvement.

Capsular and pericapsular contributions to acetabular and femoral head perfusion.

BACKGROUND: Capsular and pericapsular vessels are believed to contribute to acetabular and femoral head perfusion, but, to our knowledge, there is no anatomic study to support this theory. The purpose of this study was to describe the vascular anatomy of the hip with particular reference to the contributions of the capsular and pericapsular vessels. METHODS: Twenty fresh cadavers were dissected twenty-four hours after intra-arterial injection of colored silicone. The arteries supplying the hip were followed by careful dissection from their origins outside the pelvis to their terminal branches. Particular attention was paid to the vessels traveling between the acetabulum and the capsule and the femoral head. RESULTS: In all twenty specimens, the hip capsule received blood supply from the superior and inferior gluteal arteries proximally and from the medial and lateral femoral circumflex arteries distally. The contributory vessels entered the capsule peripherally and superficially. The circumflex arteries supplied the anterior capsule. The gluteal arteries supplied the posterior and posterosuperior aspect of the hip capsule, augmented by contributions from the circumflex arteries. Variable anastomoses were found between the gluteal and femoral systems on the capsular surface beneath the gluteus minimus and short hip external rotators. The medial femoral circumflex artery provided the dominant blood supply to the femoral head in eighteen specimens, and the inferior gluteal artery provided the dominant supply in two specimens. CONCLUSIONS: Capsular and pericapsular vessels that contribute to the blood supply of the acetabulum run on the posterior and posterolateral surface of the capsule. The dominant blood supply to the femoral head comes from vessels that approach the joint posteriorly and penetrate the joint near the femoral attachment of the capsule.

Management of bone loss in revision total knee arthroplasty.

Revision total knee arthroplasty presents several complex challenges to the adult reconstructive surgeon, including management of bone loss and ligamentous insufficiency. Bone loss patterns can be anatomically categorized and the surgical treatment can be algorithmically approached based on the bone loss pattern. In this review, we present a simplified, anatomically based classification system of bone loss patterns encountered in total knee arthroplasty. This classification system can help guide the orthopedic surgeon in prosthetic design selection, and the allograft and prosthetic augmentation options in the surgical management of these cases.