Mary Jo Adams

Why are Total Knee Arthroplasties Being Revised

Despite technical improvements, revision rates for total knee arthroplasties (TKAs) remain high. Our goal was to report the reason(s) for revision TKA in a large, current, multicenter series and compare those reasons with previously published reasons. We retrospectively identified 820 consecutive revision TKAs (693 patients, 2000-2012) from our 3 centers and recorded the primary reason for the revision. The top seven reasons for the revision were aseptic loosening (23.1%), infection (18.4%), polyethylene wear (18.1%), instability (17.7%), pain/stiffness (9.3%), osteolysis (4.5%), and malposition/malalignment (2.9%). Comparison with previously published reasons showed fewer TKA revisions for polyethylene wear, osteolysis, instability, and malalignment. These changes may represent improvements in surgical technique and implants.

Efficacy of multimodal perioperative analgesia protocol with periarticular medication injection in total knee arthroplasty: A randomized, double-blinded study

Pain control is necessary for successful rehabilitation and outcome after total knee arthroplasty. Our goal was to compare the clinical efficacy of periarticular injections consisting of a long-acting local anesthetic (ropivacaine) and epinephrine with and without combinations of an α2-adrenergic agonist (clonidine) and/or a nonsteroidal anti-inflammatory agent (ketorolac). In a double-blinded controlled study, we randomized 160 patients undergoing total knee arthroplasty to receive 1 of 4 intraoperative periarticular injections: Group A, ropivacaine, epinephrine, ketorolac, and clonidine; Group B, ropivacaine, epinephrine, and ketorolac; Group C, ropivacaine, epinephrine, and clonidine; Group D (control), ropivacaine and epinephrine. Compared with Group D, Group A and B patients had significantly lower postoperative visual analog pain scores and nurse pain assessment and Group C patients had a significantly greater reduction in physical therapist pain assessment. We found no differences in other parameters analyzed.

Midterm Results with the PFC Sigma Total Knee Arthroplasty System

We prospectively studied 207 consecutive patients (284 knees) undergoing total knee arthroplasty (June 1996 to December 1997) with a cemented tricompartmental Sigma PFC (DePuy Orthopaedics, Warsaw, Ind) total knee arthroplasty via a standard procedure (median follow-up, 87 months). Cruciate-retaining (272 knees, 96%) and cruciate-substituting (12, 4%) implants were used. There was one revision secondary to a ligament disruption after a fall. No implants were radiographically loose or at risk for loosening. Radiolucencies (none>2 mm or progressive) were shown on anteroposterior (7% of medial tibias) and lateral (17% of posterior femora) radiographs. Knee Society pain scores improved significantly (preoperative median, 20 points; postoperative median, 50 points [P<.001]). The PFC Sigma Knee system has excellent midterm durability.

Use of tranexamic acid results in decreased blood loss and decreased transfusions in patients undergoing staged bilateral total knee arthroplasty

Tranexamic acid (TXA) is an antifibrinolytic that reduces blood loss and transfusion rates in total joint arthroplasty. Blood loss and allogenic transfusion rates have not been well studied in patients receiving TXA and undergoing bilateral staged total knee arthroplasty (TKA). The purpose was to evaluate the effect of TXA on blood loss, hemoglobin (Hb) changes, and transfusion in patients undergoing staged bilateral TKA.

Unicompartmental and Total Knee Arthroplasty in the Over 70 Population

This retrospective study compares the short-term outcomes of small-incision unicompartmental knee arthroplasty (41 patients) with standard total knee arthroplasty (TKA) (50 patients) in 91 consecutive patients older than 70 years. Knee Society Scores and range of motion (ROM) were assessed preoperatively, at 6 weeks and 6 months, and through a minimum of 2 years. Postoperative comparisons included blood loss, transfusions, narcotic consumption, length of hospital stay, and complications. While Knee Scores and ROM were similar preoperatively, both were better in the unicompartmental group at each postoperative time interval. Patients with unicompartmental replacements had a much quicker return of function and discontinuation of pain medication. Blood loss was significantly more for the TKA group, as was the need for blood transfusion. None of the unicompartmental patients required transfusion. Narcotic use and length of hospital stay were also significantly less for the unicompartmental group. The overall rate of postoperative medical and surgical complications was similar for the 2 groups, with 1 major complication in each. Overall, the physiologic impact of unicompartmental knee arthroplasty was much less than TKA in this older patient population and resulted in a faster recovery.

Midterm Results of All-Polyethylene Tibial Components in Primary Total Knee Arthroplasty

Our goal was to determine the 7-year survivorship of a total knee arthroplasty system with all-polyethylene tibial components. From June 1996 to December 1997, 129 consecutive patients (177 knees) (>/=70 years old) underwent such primary arthroplasty at 2 centers in the United States. The 88 patients (120 knees) with 7 years or more of follow-up were evaluated radiographically and functionally. Average results included: Knee Society Score, 93.7 points (SD, 8.1); Knee Society function score, 68.9 points (SD, 27.6); range of motion, 119 degrees (SD, 10.9); osteolysis, 0%; stress shielding, 6.6%; progressive radiolucencies, 2.5%; Kaplan-Meier survivorship (revision), 99.4% (95% confidence intervals, 98.2%-100.0%). At midterm follow-up, an all-polyethylene tibial component proved to be an excellent surgical option for total knee arthroplasty in an elderly patient population.

Electromyographic evaluation of the midvastus approach.

Compared with the standard median parapatellar approach, the muscle-splitting midvastus approach to the knee has led to claims of an easier and earlier recovery after total knee arthroplasty, but some investigators have questioned whether the midvastus approach damages the vastus medialis obliquus. We used electromyographic and nerve conduction studies to evaluate whether we could document any such damage. Twenty patients undergoing bilateral total knee arthroplasty were randomized prospectively for the treatment of 1 knee with each of the 2 approaches. Radiographs, electromyographies, nerve conduction studies, range-of-motion tests, and Knee Society function and pain tests were conducted preoperatively and at 6 weeks postoperatively. If the electromyography or nerve conduction tests were abnormal at 6 weeks, the tests were repeated at 12 weeks. At the final follow-up, these studies showed no evidence of muscle denervation. The midvastus approach appears to be a safe alternative for knee arthrotomy for total knee arthroplasty without concerns for damage to the vastus medialis obliquus.

Minimum 5-Year Results in 96 Consecutive Hips Treated With a Tapered Titanium Stem System

We performed total hip arthroplasty with single titanium stem in 96 consecutive, nonselected hips. All patients, regardless of bone type and shape, neck shaft angulation, or age, received the same implant. Patients were followed for a minimum of 5 years, and an independent radiographer evaluated the hips for ingrowth, subsidence, leg-length discrepancy, and remodeling. The average Harris Hip score was 96 points (range, 73-100 points) at final follow-up. Radiographically, all stems were ingrown. No stem had more than 3 mm of subsidence, and there were no leg-length discrepancies more than 5 mm. We concluded that this titanium stem is a versatile option for total hip arthroplasty in patients with a wide variety of demographic and femur characteristics.

Modern Proximally Tapered Uncemented Stems Can Be Safely Used in Dorr Type C Femoral Bone

Cementless femoral fixation has become widely accepted in modern total hip arthroplasty. Treating patients who have a stovepipe-shaped femur (Dorr type C) with cementless implants has traditionally been challenging. We treated 53 consecutive patients (60 hips) who had type C bone with identical tapered, proximally coated implants and postoperative weight bearing as tolerated. At 6 weeks, all 60 hips had radiographically documented bony integration, and at 1 year, there was no evidence of fracture, subsidence, thigh pain, stress shielding, loose stems, or risk of failure. Of those patients, 40 (43 hips) had midterm follow-up (average, 6 years; range, 4-9 years); the findings were the same. We conclude that modern proximally tapered stems can be used with early weight bearing in patients with type C bone.

Medial UKA: Favorable Mid-Term Results in Middle-Aged Patients

In middle-aged patients with knee arthritis, surgical treatment options include arthroscopic procedures, osteotomies, and unicompartmental and total knee arthroplasty. Unicompartmental knee osteoarthrosis is particularly challenging and controversial in such patients. From December 2001 through October 2005, we treated 32 consecutive middle-aged patients (46 to 59 years old) with 40 medial unicompartmental knee arthroplasties. Three patients were lost to follow-up, leaving 29 for our study. There were two reoperations: one for loosening at 3 years, and one for disease progression at 5 years. Implant survival was modeled using Kaplan-Meier survival function with observations censored if lost to follow-up. At the 6-year survivorship in this group, the overall implant survival rate was 94.1% (95% CI, 78.3-98.5). Knee Society scores had improved significantly (p < 0.001). There were no other instances of osteolysis or radiographic failure. We concluded that, at mid-term follow-up, unicompartmental knee arthroplasty provided satisfactory results for this challenging population.