William G. Rodkey

Meniscal regeneration with copolymeric collagen scaffolds In vitro and in vivo studies evaluated clinically, histologically, and biochemically

We sought to create a regeneration template for the meniscal cartilage of the knee to induce complete men iscal regeneration, and to develop the technique for implanting the prosthetic appliance in vivo. We de signed a resorbable collagen-based scaffold and con ducted in vitro and in vivo studies. In vivo, the scaffold was implanted in the knees of immature swine and mature canines and evaluated clinically, histologically, and biochemically. Because the canine stifle joint me niscus is more clinically relevant to the human menis cus, this paper emphasizes those results. We studied 24 mixed breed dogs (14 males and 10 females) with an average weight of 25.5 kg (range, 20 to 35) that were obtained from a USDA-licensed sup plier. The dogs were deemed clinically and radiograph ically skeletally mature. None of the dogs had a preex isting knee joint abnormality. All dogs underwent an 80% subtotal resection of the medial meniscus bilater ally. A collagen template was implanted in one stifle (N = 24). The contralateral side served as a control: 12 dogs had a total resection alone and the other 12 dogs had an immediate replantation of the autologous meniscus. Results were tabulated at 3, 6, 9, and 12 months. At final evaluation, before the animals were euthanized, the results were submitted for statistical analysis as well as histologic and biochemical analyses. The results demonstrated that a copolymeric collagen-based scaf fold can be constructed that is compatible with meniscal fibrochondrocyte growth in vitro and in vivo, that does not inhibit meniscal regeneration in an immature pig, and that may induce regeneration of the meniscus in the mature dog. Although additional studies are necessary to perfect the scaffold and to evaluate the implant in the environ ment of the knee, these studies suggest that effective meniscal regeneration can be supported by an im planted collagen-based scaffold designed to support cellular ingrowth.

Clinical Relevance of Chondral Lesions in the Treatment of the ACL-Deficient Knee: Microfracture Technique

Anterior cruciate ligament (ACL) injuries and chondral defects are commonly associated. These chondral injuries can occur simultaneously with the ACL injury or remotely as a secondary injury from instability in the ACL-deficient knee. The literature does not provide clear direction in the management of this combination of injuries. If a chondral injury is encountered at the time of ACL treatment, we recommend that it be treated either concurrently or separately in a staged procedure. Despite a number of procedures described in the literature for chondral defects, our procedure of choice is microfracture. Microfracture is an economical, straightforward technique with a proven track record. The steps of the procedure and the associated rehabilitation process are critically related to one another, and all steps must be followed as described. The goal is to provide the optimal environment for the body’s own progenitor cells to make the reparative tissue in the defect. Over a course of 30 years, our experience with microfracture has developed and evolved through both basic science and clinical research. We have shown excellent results in treating patients with microfracture when the technique and rehabilitation are followed rigorously.

Acute Anterior Cruciate Ligament Tear Surgery: Repair Versus Reconstruction – When?

Decision making regarding treatment of a patient with an acute injury to the anterior cruciate ligament (ACL) requires careful consideration of the individual patient together with the latest evidence. While nonoperative measures are appropriate for low-demand older patients and those willing to modify their activities, many patients are treated surgically each year in an attempt to restore stability and function to the knee. The patient’s age, skeletal maturity, concomitant injuries, level of activity, and functional goals must be assessed in choosing a particular procedure. In addition, the type of ACL injury (complete vs. partial) and location of the tear (proximal vs. midsubstance vs. distal) must also be determined by physical exam and imaging to make a decision regarding the best treatment. The current evidence supports both ACL reconstruction and repair as viable options in select patient populations in specific situations. Overall, operative management of ACL injuries restores stability to the knee allowing patients to return to activities. While ACL reconstruction is considered by many as the “gold standard,” advances in basic science research over the past decade have offered new options for marrow stimulation and primary repair. In addition, continued clinical research will help determine the long-term outcomes and consequences of each type of treatment.