Intraoperative blood management in joint replacement surgery.

Interest is growing in blood conservation and avoidance of transfusion in patients undergoing orthopedic surgery, especially in the field of joint replacement. Several methods have proven successful in reducing intraoperative blood loss, which can translate into lessened allogeneic and autologous transfusion requirements. Available techniques include acute normovolemic hemodilution, hypotensive anesthesia, intraoperative blood salvage, specialized cautery, topical hemostatic agents, and pharmacologic agents given in the perioperative period.

Cemented posterior stabilized total knee arthroplasty.

In the development of modern cemented total knee arthroplasty, the posterior stabilized knee prosthesis was designed to substitute for the function of the posterior cruciate ligament. Implant designs include the Insall Burstein posterior stabilized knee and the Legacy posterior stabilized knee. The primary feature of these prostheses is the femoral cam and tibial spine mechanism, which prevents posterior tibial subluxation and enhances knee kinematics.

Hyaluronan therapy: looking toward the future.

Hyaluronan therapy has numerous medical applications, including the treatment of joint arthropathies, wound healing, prevention of postsurgical adhesions, treatment of urinary incontinence, ophthalmic surgery, and tissue augmentation and engineering. Studies have been conducted and are ongoing to evaluate the efficacy of intra-articular hyaluronans in disease modification in osteoarthritis of the knee; efficacy in disease states other than osteoarthritis; as adjunct therapy after joint surgery; and in joints other than the knee--namely the shoulder, hand, hip, temporomandibular joint, spine, foot, and ankle. Preliminary results have been promising and parallel what has been found in treatment of osteoarthritis of the knee.

Intra-articular hyaluronans in knee osteoarthritis: rationale and practical considerations.

Intra-articular hyaluronans are used to treat pain associated with osteoarthritis of the knee. Many controlled clinical studies have demonstrated their efficacy for this indication. The rationale for the use of hyaluronans therapeutically is based on observations that hyaluronic acid is an important component of the synovial fluid acting as a cushion and lubricant for the joint and also serving as a major component of the extracellular matrix of the cartilage, helping to enhance the ability of cartilage to resist shear and maintain a resiliency to compression.

Digital imaging and video: principles and applications.

Digital imaging has provided orthopaedic surgeons with new, powerful tools that offer a multitude of applications. Already integral to several common medical devices, digital images can be used for case documentation and presentation as well as for diagnostic and surgical patient care information. Educational presentation has been transformed by the use of computers and digital projectors.

A quantitative histologic comparison: ACL degeneration in the osteoarthritic knee.

Newer prosthetic total knee arthroplasty (TKA) designs as well as unicondylar TKAs spare the anterior cruciate ligament (ACL). Although success of these procedures requires near normal ACL function, little has been written about the histologic features or the arthritic ACL. This study was designed to histologically evaluate the ACL for microscopic evidence of degeneration.

Routine patellar resurfacing: a viable option.

The literature on routine patellar resurfacing documents that the rate of anterior knee pain after TKA is the same whether the patella is resurfaced or unresurfaced. The complication rate is different in these groups. In patients in whom the native patella is left, the rate of reoperation is approximately 10%.

The impact of femoral component rotational alignment on condylar lift-off.

The surgical technique and implant design influence femoral condylar lift-off in total knee arthroplasty. With the use of the classic method of bone resection and appropriate soft tissue releases, alignment of the femoral component along the transepicondylar axis will create a symmetric and balanced flexion space. This surgical technique will reduce the incidence of condylar lift-off.

Flexion instability in primary total knee replacement.

Although the results of TKR are highly successful at long-term follow-up, failures occur. One of the more frequent causes of failure is instability. In distinction to instability in the medial-lateral plane, AP instability in flexion has been poorly described until recently.

The role of debridement: through small portals.

Arthroscopic debridement represents one option for treatment of the patient with degenerative arthritis of the knee. Numerous procedures, including joint lavage, removal of loose bodies, partial meniscectomy, and techniques to stimulate cartilage repair may be included under this topic. Understanding surgical indications and clinical results requires differentiation of these individual components where possible.

Tibial tubercle osteotomy.

During primary and revision TKA, difficulties with exposure may be due to poor motion, obesity, and patellar baja. To gain accurate component positioning and avoid catastrophic complications with the extensor mechanism, a stepwise approach to optimizing the exposure should be used. In cases where the standard medial parapatellar arthrotomy is inadequate, a quadriceps snip is helpful.

Long-term results of posterior cruciate-substituting total knee arthroplasty.

Posterior cruciate ligament-substituting total knee prostheses have been used extensively since the original posterior-stabilized condylar prosthesis was introduced more than 2 decades ago. The key design principle of this prosthesis was the incorporation of a cam and post mechanism on the femoral and tibial components. This mechanism was intended to function as a mechanical substitute for the posterior cruciate ligament, to optimize prosthesis roll back in flexion, and to avoid flexion instability by preventing posterior subluxation.

The Insall legacy in total knee arthroplasty.

John N. Insall was a pioneer in the field of knee surgery. He was a rare individual who accomplished unparalleled levels of success as a surgeon, designer, and teacher.

Knee: axial instability.

The long term results of total knee replacement are among the most successful of any orthopedic procedure; however, certain patterns of failure have been identified including varus-valgus instability and anterior-posterior instability in flexion. While trauma may cause acute ligamentous injury that results in instability, the majority of cases likely result from intraoperative decisions that result in malalignment and inadequate soft tissue balancing. Failure to restore medial-lateral soft tissue balance with symmetric flexion and extension spaces may result in postoperative instability.

Does modularity affect clinical success? A comparison with a minimum 10-year followup.

A comparison of the clinical and radiographic results of patients with metal-backed monoblock Insall-Burstein I and modular Insall-Burstein II Posterior Stabilized Knee Prostheses was done. The minimum followup was 10 years. The clinical results were comparable with a similar average Hospital for Special Surgery knee score of 85 and 84 points, respectively.