Mako™ Robotic-Arm Assisted Medial Unicompartmental Knee Arthroplasty: Surgical Technique from the Office to the Operating Room.

The utilization of robotic-arm assisted unicompartmental knee arthroplasty (UKA) or partial knee arthroplasty (PKA) for the treatment of medial unicompartmental osteoarthritis has continued to increase. This is in part due to the consistently reproducible accuracy and precision of implant planning, intra-operative ligament balancing software, tracking optimization software, robotic-arm assisted bone preparation, excellent survivorship rates, and improvements in many patient-reported outcomes compared to manual UKA, using the Stryker Mako™ Robotic Partial Knee System (Stryker, Mako Surgical Corp., Mahwah, New Jersey). Training in the utilization of robotic-arm assistance can be time-consuming and comes with an associated learning curve even after the in-person training and coursework is complete, like most procedures. Therefore, our aim was to describe the pre-operative planning and intra-operative surgical technique for using a robotic-arm assisted partial knee system for UKA/PKA in patients who have unicompartmental medial knee osteoarthritis. Specifically, we will discuss: 1) pre-operative planning; 2) operative setup; 3) intra-operative steps; 4) execution of the plan; and 5) trialing, implantation, and final assessments.

Simultaneous Bilateral Total Knee Arthroplasty Becomes Safer after Institution of Optimal Perioperative Management: A Longitudinal Cohort Study.

Simultaneous bilateral total knee arthroplasty (SBTKA) increases the rates of procedure-related complications and mortality compared with unilateral TKA. There are no well-defined guidelines for selecting patients to avoid mortality and proposing an upgrade treatment to decrease complication rates. This study aimed to evaluate whether optimal perioperative management could improve the safety of SBTKA. From 2005 to 2017, 1,166 cases of SBTKA were identified from 14,209 TKA procedures. We retrospectively examined the SBTKA patients' demographics, comorbidity profiles, procedure-related complications, and perioperative management during two time periods. Optimal perioperative workup for managing SBTKA significantly decreased the incidences of major complication from 6.2 to 2.4% (p = 0.001) and minor complications from 28.9 to 21.5% (p = 0.004) during period I and period II, respectively. The efficiency of less tourniquet use along with intraarticular tranexamic acid injection was demonstrated by the decreases of hemoglobin (Hb) change in the first 2 days after surgery (p = 0.005) and blood transfusion requirement (p = 0.035) during the SBTKA. Furthermore, the less tourniquet use group had less thigh pain (visual analog scale decreased from 6.0 to 4.2, p = 0.003), shorter duration of hospital stay (decreased from 7.8 to 7.1, p < 0.001), and lower coagulation time (decrease from 3.5 to 2.9, p < 0.001) than the routine tourniquet use group. Patient's screening must be performed carefully for cardiopulmonary compromise in patients aged >80 years and with an American Society of Anesthesiologists score of 3. Additionally, hospitalists should consider developing methods for the eligibility, testing, and perioperative monitoring of patients who undergo SBTKA with the aim of avoiding complications and improving outcomes.

Twenty-year evaluation of the New Jersey LCS Rotating Platform Knee Replacement.

Clinical results of the initial cemented and cementless series of 233 New Jersey Low Contact Stress Rotating Platform Knee Replacements in 184 patients surviving at least 10 years were analyzed using a strict knee scoring scale. The study showed excellent (46.7%) and good (53.3%) results in primary cemented rotating platform knee replacements, and excellent (68.1%), good (29.8%), and fair (2.1%) results in primary cementless rotating platform knee replacements. Radiographic evaluation at a minimum 10-year follow-up showed stable fixation of all components, no gross migration but significant osteolysis requiring bearing exchange, and bone grafting in three cementless rotating platform knee replacements (1.8%) in three patients who underwent previous surgeries at an average 10.2 years from the index surgery. Survivorship of the patients who underwent primary cemented rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 97.7% at 10 and 20 years. Survivorship of the patients who underwent cementless rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 98.3% at 10 and 18 years.

Ten-year evaluation of cementless Buechel-Pappas meniscal bearing total ankle replacement.

A porous-coated, cementless, congruent-contact, three-piece, meniscal-bearing total ankle replacement was developed and used clinically over a 2- to 10-year period for patients with disabling ankle arthritis. Polished titanium-nitride ceramic-coated Ti6Al4V tibial and talar components with a deep-sulcus trochlear groove and two lateral fixation fins for the talar onlay component were used. The ultra-high-molecular-weight polyethylene (UHMWPe) meniscal bearing congruently conformed to the flat upper tibial component surface and the deep sulcus and cylindrical geometry of the lower talar component surface. Fifty deep-sulcus (Buechel-Pappas) total ankle replacements were implanted in 49 patients. Diagnoses were 8 osteoarthritis (16%), 7 rheumatoid arthritis (14%), 2 avascular necrosis (4%), and 33 post-traumatic arthritis (66%). Ages ranged from 26 to 71 years (mean 49 years). Clinical results using a strict ankle scoring system demonstrated good/excellent results in 88% of cases. Postoperative ankle motion ranged from 12 degrees to 46 degrees total arc (mean 28 degrees), which was similar to the preoperative motion. Revision for malalignment was necessary in two cases (4%). Mechanical complications included one case of meniscal bearing wear (2%) in a patient with post-traumatic arthritis with component malalignment and one case of talar component subsidence (2%) in a patient with avascular necrosis of the talus. No tibial component loosening was seen. Cumulative survivorship using an end point of revision of any component for any reason was 93.5% at 10 years (confidence interval 61-100%).

Primary exchange revision arthroplasty for infected total knee replacement: a long-term study.

Infected knee replacement is a serious complication that requires significant hospital-based resources for successful management. A successful primary exchange revision technique offers decreased morbidity for the patient by eliminating a second major operation and associated hospitalization, which in turn substantially reduces the cost associated with this dreaded condition. Twenty-two consecutive infected primary total knee arthroplasties in 22 patients were treated with primary exchange revision arthroplasties using antibiotic-impregnated cement. The surgical technique consisted of excision of draining sinuses, complete synovectomy, removal of granulation tissue, and debulking of the extensor mechanism. Postoperative treatment consisted of 4 to 6 weeks of parenterally administered antibiotics and 6 to 12 months of orally administered antibiotics. Both gram-positive and gram-negative organisms were treated. At an average follow-up of 10.2 years (range, 1.4 to 19.6 years), 90.9% were free of recurrent infection. Knee scores averaged 79.5, with 85.7% good or excellent results. The physiological classification of the host appeared to influence the outcome of revision. All patients in class A or B (20 knees) had successful eradication of their primary infection after 1-stage revision, whereas the only failure in the group was a physiological class C patient, who eventually expired from ongoing end-organ liver failure. These results compare most favorably with those of delayed-exchange revision arthroplasty while providing a more cost-effective management program.

Failure modes of current total ankle replacement systems.

Methodology for evaluation of total ankle replacements is described. Fusion and its problems are discussed as are those of total ankle joint replacement. Fusion is an imperfect solution because it reduces ankle functionality and has significant complications. Early fixed-bearing total ankles were long-term failures and abandoned. Currently available fixed-bearing ankles have proved inferior to fusion or are equivalent to earlier devices. Only mobile-bearing devices have been shown reasonably safe and effective. One such device, the STAR, has been approved by the Food and Drug Administration after a rigorous controlled clinical trial and is available for use in the United States.

Mobile-bearing knee arthroplasty: rotation is our salvation!

Rotating-platform knee arthroplasties have enjoyed an outstanding clinical history since their introduction in 1978. Mechanical complications requiring further surgery have been identified and include loosening, bearing dislocation, bearing wear, and osteolysis. No structural, metallic failures were reported, although extreme bearing wear was noted to cause metal surface damage sufficient to require revision in isolated cases. Survivorship of primary LCS cemented rotating-platform knee arthroplasties using an endpoint of revision of any component for any reason was 97.7% at the 20-year interval. Survivorship of primary LCS cementless rotating-platform knee arthroplasties using the same endpoint was 98.3% at the 18-year interval.

The infected total knee arthroplasty: just when you thought it was over.

Of the various options available for infected total knee arthroplasties (TKAs), a successful primary-exchange revision technique offers decreased morbidity for the patient by eliminating a second major surgery and associated hospitalization, and substantially reduces the cost associated with this dreaded condition. In 22 infected TKAs treated by a 1-stage revision and followed for an average of 10.2 years (range, 1.4-19.6 years), 90.9% were free of recurrent infection. Knee scores averaged 79.5, with 85.7% good or excellent results. The physiologic classification of the host appeared to influence the outcome of revision. All patients in class A or B (20 knees) had successful eradication of their primary infection after 1-stage revision; 2 physiologic class C patients developed early failure secondary to poor wound healing.

Knee arthroplasty in post-traumatic arthritis.

Post-traumatic arthritis of the knee can involve the tibiofemoral joint, patellofemoral joint, or both joints. In the tibiofemoral articulation, disabling injuries include articular crush, condylar split, shaft involvement, ligamentous injuries, or a combination. In the patella, similar injuries include articular crush, large or stellate displaced fractures, tendon disruption, or a combination. Cementless mobile-bearing knee arthroplasty principles and implants can provide satisfactory long-term results in patients with complex post-traumatic knee arthritis. Primary, resurfacing unicompartmental or total knee implants can be used for articular damage, whereas more complex modular or constrained implants and osteotomies are needed for angular or combined deformities. Bearing exchange revision may be needed for young, active patients within 20 years of their initial arthroplasty.

Long-term followup after mobile-bearing total knee replacement.

Clinical and radiographic analyses and survivorship were done on the initial cementless series of 309 posterior cruciate-retaining meniscal-bearing and rotating-platform New Jersey LCS total knee replacements followed up for 10 to 20 years (mean, 12.4 years). Clinical results in patients surviving at least 10 years using a strict knee scoring scale were similar for posterior cruciate ligament-retaining and posterior cruciate ligament-sacrificing designs. Good to excellent results were seen in 97.9% of primary posterior cruciate-retaining-bearing prostheses and in 97.9% of primary rotating-platform prostheses. Radiographic analysis of minimum 10-year followup radiographs showed generally stable fixation of all components with gross migration seen in one tibial component (0.6%) in a patient with a failed high tibial osteotomy. Significant osteolysis was present requiring bearing exchange and bone grating in three patients with cementless rotating-platform prostheses (1.8%) who had multiple knee surgeries at an average of 10.2 years from the index surgery. Survivorship of the primary cementless posterior cruciate-retaining meniscal-bearing prostheses with an end point of revision for any mechanical reason was 97.4% at 10 years and 83% at 16 years; using an end point of a poor clinical knee score, the survivorship was 98.9% at 10 and 16 years, respectively. Survivorship of the primary cementless rotating-platform prostheses with end points of revision for any mechanical reason or a poor clinical knee score was 98.3% survivorship at 10 and 18 years, respectively. In the current study, no cementless rotating-bearing patella loosened, fractured, or dissociated in patients without prior knee surgery although one cementless rotating-bearing patella (0.6%) in a patient who had multiple knee surgeries wore through the inferior marker wire after 10.8 years, causing metallosis that required revision.

Twenty-year evaluation of cementless mobile-bearing total ankle replacements.

Two consecutive series of patients who had cementless, porous-coated, congruent-contact, mobile-bearing total ankle replacements were evaluated during a 20-year interval using the New Jersey Orthopaedic Hospital ankle scoring scale to determine clinical outcome and overall implant survivorship with revision as an end point. The initial series of 38 patients (40 ankle replacements) using a shallow-sulcus design had diagnoses of: osteoarthritis, seven (17.5%); rheumatoid arthritis, nine (22.5%); posttraumatic arthritis, 21 (52.5%); and failed fusion, three (7.5%). Clinical results after 2-20 years, (mean, 12 years) were 28 (70%) good to excellent, two (5%) fair, and 10 (25%) poor. Postoperative ankle motion ranged from 10 degrees-47 degrees total arc (mean, 25 degrees total arc). The 20-year overall survivorship for the shallow-sulcus design was 74.2%. A second series of 74 patients (75 ankle replacements) using a deep-sulcus design had diagnoses of: osteoarthritis, eight (11%); rheumatoid arthritis, nine (12%); osteonecrosis, three (4%); and posttraumatic arthritis, 55 (73%). Clinical results after 2-12 years, (mean 5 years) were 66 (88%) good to excellent, four (5%) fair, and five (7%) poor. Postoperative ankle motion ranged from 10 degrees-50 degrees total arc (mean, 29 degrees total arc). The 12-year overall survivorship for the deep-sulcus design was 92%.

Two- to 12-year evaluation of cementless Buechel-Pappas total hip arthroplasty.

A unique, straight-stemmed, proximally porous-coated, modular hip arthroplasty system, coated with thin-film (5- to 9-microm), titanium-nitride ceramic, was used clinically in 130 hip arthroplasties in 117 patients who were followed over a 2- to 12-year interval (mean, 6.45 years). Harris Hip Scores demonstrated 82.3% excellent, 15.4% good, 2.3% fair, and 0% poor results. Thigh pain that limited activities of daily living was seen in 0.8% (1 of 130) hips. Kaplan-Meier survival estimates using an endpoint of revision of any component for any reason demonstrated an overall survival of 95.5% during the 12-year interval. Cementless fixation survivorship of the acetabular and femoral components was 98.5% during the 12-year interval.