Linked kinematic knee balancing in unicompartmental knee arthroplasty.

The traditional approach of restoring a neutral mechanical axis to the lower extremity during total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) has long been favored due its consistency and reproducibility. The kinematic alignment approach, which accounts for the patient's natural knee alignment and is commonly a few degrees varus to the mechanical axis, has gained popularity in recent years as a technique which reestablishes a more anatomic alignment. Linked Anatomic Kinematic Arthroplasty (LAKA), an extension of the kinematic approach that employs computer-assisted surgical (CAS) navigation, can improve the accuracy and precision of kinematic measurements in unicompartmental knee arthroplasties. This article will describe the LAKA technique in UKA and review early clinical outcomes associated with this technique.

Linked Anatomic Kinematic Arthroplasty: A Unique Approach to Balancing in Total Knee Arthroplasty.

Traditional approaches to total knee arthroplasty (TKA) aim to reestablish a neutral mechanical axis of the lower extremity. However, many studies have shown great variation in normal knee anatomy, suggesting that the ideal alignment may not be identical for every patient. Linked Anatomic Kinematic Arthroplasty (LAKA) offers a novel kinematic approach to TKA. Using computer navigation, LAKA technique can optimize the kinematic alignment while ensuring that coronal alignment is kept within standard mechanical ranges. This article will outline the surgical approach to LAKA and briefly review the outcomes of this approach.

Osteochondral Allograft Transplantation in Patients With Osteochondritis Dissecans of the Knee.

BACKGROUND: Osteochondritis dissecans (OCD) of the knee can be difficult to treat. Cartilage restoration techniques are often indicated when the lesion or fragment cannot be salvaged and the patient remains symptomatic. Fresh osteochondral allograft (OCA) transplantation can restore both bone and cartilage defects characteristic of OCD. HYPOTHESIS: We hypothesized that osteochondral allografting is a successful method for treating OCD of the knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study comprised 135 patients (149 knees) who underwent OCA for OCD of the knee (type III or IV) between 1997 and 2013 and had a minimum follow-up of 2 years. The median age was 21 years (range, 12-55 years) and 75.8% of the patients were male. The mean allograft size was 7.3 cm2 (range, 2.2-25 cm2). Evaluation included the following: frequency and type of reoperations; modified Merle d'Aubigné and Postel (18-point) scale; International Knee Documentation Committee (IKDC) pain, function, and total scores; and Knee Society function (KS-F) and knee (KS-K) scores. Clinical failure was defined as revision OCA or conversion to arthroplasty. Graft survivorship was determined. RESULTS: The median follow-up time was 6.3 years (range, 1.9-16.8 years) and 62% of participants had more than 5-year follow-up. Thirty-four of 149 knees (23%) had reoperations, of which 12 (8%) were classified as allograft failures (7 OCA revisions, 3 unicompartmental knee arthroplasties, and 2 total knee arthroplasties). OCA survivorship was 95% at 5 years and 93% at 10 years. Of the 137 knees whose grafts were still in situ at the latest follow-up, the mean modified Merle d'Aubigné and Postel (18-point) score was 16.8; IKDC pain, function, and total scores were 2.1, 8.1, and 82.3; and KS-F and KS-K scores were 95.7 and 94.3, respectively. The majority of patients (95%) reported being satisfied with the outcome of their procedure. CONCLUSION: OCA transplantation was an effective treatment for OCD of the knee, with a low rate of graft failure, significant improvement in pain and function scores, and high patient satisfaction.

The Use of Osteochondral Allograft Transplantation for Primary Treatment of Cartilage Lesions in the Knee.

OBJECTIVE: To assess the outcome of osteochondral allograft (OCA) transplantation as the primary treatment for cartilage injury in patients with no previous surgical treatment. STUDY DESIGN: Case series. Patients were identified in our outcomes database. Patients undergoing primary OCA transplantation with no prior surgical treatment and a minimum of 2 years follow-up were selected. Pain and function were evaluated preoperatively and postoperatively. Patient satisfaction was assessed. Reoperations following OCA transplantation were captured. Failure was defined as revision OCA or conversion to arthroplasty. RESULTS: Fifty-five patients (61 knees) were included in the analysis. The study consisted of 30 males and 25 females (mean age = 32.9 years; range = 15.7-67.8 years). The most common diagnoses for the OCA transplantation were osteochondritis dissecans (44.3%) and avascular necrosis (31.1%). Pain and function improved preoperatively to postoperatively on all outcome scales (P < 0.01). The majority of patients (86%) were "extremely satisfied" or "satisfied." OCA survivorship was 89.5% at 5 years and 74.7% at 10 years. At latest follow-up (mean = 7.6 years; range = 1.9-22.6 years), OCA remained in situ in 50 knees (82%). Eighteen knees (29.5%) had further surgery; 11 OCA failures and 7 other surgical procedure(s). Of the failed knees (mean time to failure = 3.5 years; range = 0.5-13.7 years), 8 were converted to arthroplasty, 2 had OCA revisions, and 1 had a patellectomy. CONCLUSIONS: OCA transplantation is an acceptable primary treatment method for some chondral and osteochondral defects of the knee. Failure of previous treatment(s) is not a prerequisite for OCA transplantation.

The role of immunologic response in fresh osteochondral allografting of the knee.

BACKGROUND: Osteochondral allografting, a restorative treatment option for articular cartilage lesions in the knee, involves transplantation of fresh osteochondral tissue with no tissue matching. Although retrieval studies have not consistently shown evidence of immunologic response, development of anti-human leukocyte antigen class I cytotoxic antibodies has been observed in allograft recipients. HYPOTHESIS: Postallograft antibody formation is related to graft size and may affect clinical outcome. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study retrospectively compared 42 antibody-positive postallograft patients with 42 antibody-negative patients. Groups were matched for age, sex, and body mass index but not intra-articular disease severity. Seventeen patients (20%) were lost to follow-up. Of the remaining 67 patients (33 antibody-positive and 34 antibody-negative), average follow-up time was 50.3 months (range, 24-165 months). Mean age was 38.1 years (range, 15-68 years) with 58% being male. Graft area was categorized as small (<5 cm2), medium (5-10 cm2), or large (>10 cm2). Graft survival and Knee Society function scores were used to measure clinical outcome. RESULTS: Of the 84 patients, 80 had graft area data. Of 27 patients with large graft area, 19 (70%) had positive postoperative antibody screens, compared with 1 of 16 (6%) with small graft area (P < .001). Graft survival rates in the antibody-positive and antibody-negative groups were 64% and 79%, respectively (P = .152). Mean postoperative Knee Society function scores in surviving antibody-positive and antibody-negative groups were 88.3 and 84.6 points, respectively (P = .482). CONCLUSION: Antibody development after fresh, non-tissue-matched osteochondral allograft transplants in the knee appears related to graft size. No difference was observed in clinical outcome between groups. Graft survival is multifactorial, and the effect that the immunologic response has on clinical outcome merits further investigation.

Bilateral pseudogout 8 years after bilateral total knee arthroplasty.

This article presents the clinical features of crystal arthropathy after knee replacement. The current literature on pseudogout and gout after both total and partial knee replacement is summarized. A case of bilateral pseudogout 8 years after initial total knee arthroplasty (TKA) is used to highlight the clinical characteristics and treatment options for this underrecognized condition. Presentation mimicked a late septic joint arthroplasty with sudden onset of pain and effusion. The patient was treated successfully with an arthrotomy, debridement, synovectomy, polyethylene insert exchange, oral steroids, and nonsteroidal anti-inflammatories. There are no other reported cases of bilateral pseudogout after bilateral TKA.