Shinichi Maeno

Fifteen-Year Outcome of Endoscopic Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft for “Isolated” Anterior Cruciate Ligament Tear

Background: Few studies report the long-term results of anterior cruciate ligament rupture and single-incision endoscopic reconstructive surgery. Outcomes are often clouded by concomitant meniscal, chondral, or ligament injuries. Purpose: To determine the 15-year outcomes of anterior cruciate ligament ruptures treated with endoscopic anterior cruciate ligament reconstruction using middle-third patellar tendon autograft. Study Design: Case series; Level of evidence, 4. Methods: Between January 1993 and April 1994, 333 consecutive patients underwent anterior cruciate ligament reconstruction. Patients with associated ligamentous injury requiring surgery, previous meniscectomy, or meniscal injury requiring more than one-third meniscectomy; chondral injury diagnosed at arthroscopy; and an abnormal contralateral knee were excluded. Ninety patients met the inclusion criteria. Outcomes included range of motion, Lachman and pivot-shift tests, instrumented ligament testing, single-legged hop test, Lysholm Knee Score, the International Knee Documentation Committee evaluation, and radiographic assessment. Results: Thirty percent of patients had further anterior cruciate ligament injury. Twenty-four percent of patients (n = 22) sustained contralateral anterior cruciate ligament ruptures, and 8% (n = 7) ruptured the graft (P = .009). Graft rupture was associated with a graft inclination angle <17° (P = .02). Contralateral anterior cruciate ligament rupture was associated with age <18 years at time of primary injury (P = .001). All patients had normal or nearly normal (International Knee Documentation Committee evaluation) Lachman and instrumented testing, and 91% had a negative pivot-shift result. Seventy percent of patients had kneeling pain. Median subjective International Knee Documentation Committee evaluation was 91 of 100. Fifty-one percent of patients had radiographic evidence of osteoarthritis (41% grade B; 10% grade C). Conclusion: Good results are maintained at 15 years after surgery with respect to ligamentous stability, subjective outcomes, and range of motion. Kneeling pain remains a significant problem. Concern remains regarding the incidence of further anterior cruciate ligament injury and the increasing number of patients with radiographic and clinical signs of osteoarthritis despite surgical stabilization.

Five-Year Comparison of Oxidized Zirconium and Cobalt-Chromium Femoral Components in Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND In vitro analysis has shown that oxidized zirconium on ultra-high molecular weight polyethylene has better wear properties than cobalt-chromium on ultra-high molecular weight polyethylene. The purpose of this study was to determine if oxidized zirconium femoral components performed better than cobalt-chromium in vivo and if the use of oxidized zirconium components had clinical adverse effects. METHODS Forty consecutive patients (eighty knees) underwent simultaneous bilateral cruciate-retaining total knee arthroplasty for primary osteoarthritis from January 2002 to December 2003. For each patient, the knees were randomized to receive the oxidized zirconium femoral component, with the contralateral knee receiving the cobalt-chromium component. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index, Knee Injury and Osteoarthritis Outcome Score, Knee Society score, and British Orthopaedic Association patient satisfaction scale. Radiographic outcomes include the Knee Society total knee arthroplasty roentgenographic evaluation and scoring system and measurement of radiographic wear. Patients and assessors were blinded to the treatment groups and results. RESULTS There were no significant differences in clinical, subjective, and radiographic outcomes between the two implants at five days, six weeks, and one, two, or five years postoperatively. At five years following surgery, 38% of the patients preferred the cobalt-chromium knee compared with 18% who preferred the oxidized zirconium knee (p = 0.02) and 44% had no preference. CONCLUSIONS Five-year outcomes after total knee arthroplasty with oxidized zirconium and cobalt-chromium femoral components showed no significant differences in clinical, subjective, and radiographic outcomes. Patients had no preference or preferred the cobalt-chromium prosthesis to the oxidized zirconium prosthesis at the time of the five-year follow-up. There were no adverse effects associated with the use of oxidized zirconium femoral implants.

Case reports: Patellar impingement against the tibial component after total knee arthroplasty

Patella baja developed in seven knees in five patients after posterior stabilized total knee arthroplasties when the patella became impinged against the tibial component. Patellar replacement was performed in four knees, and all patients were able to achieve deep flexion postoperatively. The mean followup was 50 months (range, 24-73 months) for these patients. The mean Insall-Salvati ratio changed from 0.87 (range, 0.70-1) immediately postoperatively to 0.66 (range, 0.55-0.84) at followup. Patellar erosion occurred in three knees without patellar replacements, accompanied by pain and reduced range of flexion. The four knees with patellar replacements showed marked erosion of the patellar component or the patella, but all remained asymptomatic. Achieving deep flexion in addition to patella baja was thought to be a key element. Patellar replacement, joint line preservation, shaving the anterior portion of the tibial component, preventing surgically induced patella baja, and careful radio- graphic followup should be considered when deep flexion is achieved in a knee with patella baja after a total knee arthroplasty. Level of Evidence: Prognostic Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Extraarticular Arthroscopy of the Knee

Shinichi Maeno1, Daijo Hashimoto2, Toshiro Otani3, Ko Masumoto4, Itsuki Yuzawa5, Kengo Harato6 and Seiji Saito1 1Department of Orthopedic Surgery, Shioya Hospital of International University of Health and Welfare, Tochigi, 2Department of Surgery, Josai Hospital, Tochigi, 3Keio University Faculty of Nursing and Medical Care, Tokyo, 4Masumoto Clinic, Tokyo, 5Department of Orthopedic Surgery, Terada Hospital, Tokyo, 6Department of Orthopedic Surgery, Kawasaki Municipal Kawasaki Hospital Japan

A Novel Surgical Technique for Patellar Fracture: Application of Extra-articular Arthroscopy With Hanger-Lifting Procedure.

We describe a novel operative technique for patellar fracture. The patient is placed in the supine position for setup of both an image intensifier and arthroscopy. After routine intra-articular inspection with an arthroscope, an extra-articular space including the prepatellar bursa is developed. The space is created with a lifting hanger applied from a portal wherein an arthroscope can then afford both intra- and extra-articular observation of the articular and bony surface of the patella. By use of an image intensifier, the fracture can be treated and fixed in percutaneous fashion with the aid of an arthroscope. This new technique offers surgeons a magnified view of the patella, both intra- and extra-articularly, through a minimally invasive procedure. Although it includes inherent risks and limitations, this new application of arthroscopy would certainly help surgeons to treat patellar fracture.

Factors Affecting Longer Surgical Times in Total Knee Arthroplasty for Obese Patients—A Comparative Study between High- and Nonhigh-Volume Surgeons

Abstract Obesity has a negative influence on surgical times in total knee arthroplasty (TKA). Our purpose in this multicenter study was to compare surgical times between high‐ (HV) and nonhigh‐volume (NHV) surgeons and clarify the important factors affecting longer surgical times in primary TKA for obese patients. A total of 798 knees, average age 75.1 years, were enrolled. All TKAs were done using the same measured resection technique by 25 surgeons at 12 facilities and were divided into three groups based on body mass index (kg/m2) of the patients (Group A: <24.9, Group B: 25‐29.9, Group C: ≥30). Operative techniques including four surgical steps (surgical exposure, bone cutting, trial and fixation of the permanent component, and wound closure) were evaluated both in HV and NHV surgeons. In classifying surgeon volume, HV surgeons had performed >100 TKAs annually for many years, and other surgeons who had performed <100 TKAs annually were defined as NHV surgeons. Patient demographics, surgical details, and surgical times in each phase were compared using nonrepeated measures of analysis of variance and a post hoc Student‐Newman‐Keuls test. A total of 331, 327, 140 TKAs were allocated to Groups A, B, C, respectively. Regarding patient demographics, patients in Group C were younger and had the worst ranges of motion. The longest surgical time was observed in Group C of NHV surgeons (p < 0.05). Concerning each surgical phase, surgeons took much more time in surgical exposure and fixation of the permanent component for obese patients in NHV surgeons (p < 0.05). Our results suggest that younger age and lower range of motion were observed in obese patients, which led to longer surgical times. In addition, NHV surgeons took much time in surgical exposure and fixation of the permanent component for obese patients, while surgical time was similar among groups for HV surgeons.