Navigated "small implants" in knee reconstruction.

Purpose: At the beginning of this century, unprecedented interest in the concept of using less invasive approaches for the treatment of knee degenerative diseases was ignited. Initial interest in this approach was about navigated and non-navigated knee reconstruction using small implants and conventional total knee arthroplasty.

Methods: To this end, a review of the published literature relating to less invasive compartmental arthroplasty of the knee using computer-based alignment techniques and on soft tissue-dedicated small implants is presented.

A flat all-polyethylene tibial component in medial unicompartmental knee arthroplasty: a long-term study.

Purpose: The aim of this study is to present the clinical and radiological results of a cemented unicompartmental knee arthroplasty (UKA) using a flat all-polyethylene tibial component at long-term follow-up, in a homogeneous group of patients with medial femoro-tibial knee arthritis.

Methods: The study group included 53 knees in 51 patients who were treated between January 1998 and November 1999 using a flat all-polyethylene tibial component. The same surgical technique was used for all patients.

Computer-assisted unicompartmental knee arthroplasty using dedicated software versus a conventional technique.

Purpose: The aim of this study was to retrospectively compare the results of two matched-paired groups of patients who had undergone a medial unicompartmental knee arthroplasty (UKA) performed using either a conventional or a non-image-guided navigation technique specifically designed for unicompartmental prosthesis implantation.

Methods: Thirty-one patients with isolated medial-compartment knee arthritis who underwent an isolated navigated UKA were included in the study (group A) and matched with patients who had undergone a conventional medial UKA (group B). The same inclusion criteria were used for both groups.

Spontaneous patella fracture associated with anterior tibial tubercle pseudarthrosis in a revised knee replacement following knee arthrodesis.

Background: Conversion of a knee arthrodesis to a Total Knee Arthroplasty is an uncommon procedure. Revision Total Knee Arthroplasty in this setting presents the surgeon with a number of challenges including the management of the extensor mechanism and patella.

Case Presentation: We describe a unique case of a 69 years old Caucasian man who underwent a revision Total Knee Arthroplasty using a tibial tubercle osteotomy after a previous conversion of a knee arthrodesis without patella resurfacing.

Computer-assisted total knee arthroplasty after prior femoral fracture without hardware removal.

This study presents a consecutive series of patients who underwent total knee arthroplasty (TKA) after prior distal femoral fracture without hardware removal. The purpose of this study was to determine the effectiveness of computer-assisted TKA in patients with posttraumatic arthritis, specifically those with retained hardware after prior distal femoral fracture. The study group included a consecutive series of 16 patients who had developed posttraumatic knee arthritis after a distal femoral fracture with retention of hardware (group A).

Post traumatic knee arthritis: navigated total knee replacement without hardware removal.

Background: The Authors present the results of a series of navigated total knee replacements (TKR) without hardware removal in patients with post-traumatic arthritis following femoral fractures. The purpose of the paper was to determine the effectiveness of computer-assisted TKR in these patients compared to routine primary implants.

Methods: Sixteen patients with post-traumatic knee arthritis following a distal femoral fracture and retained hardware were included in the study (group I).

An uncommon cause of cemented unicompartmental knee arthroplasty failure: fracture of metallic components.

Purpose: Despite good overall clinical results, unicompartmental knee replacements (UKR) are not without their problems and failures have been reported. The most common causes of UKR failure are component loosening, poor patient selection, poor surgical technique, polyethylene wear and progression of arthritis in other compartments. The purpose of this study is to present a series of atraumatic fractures of metallic components in a UKR treated in a single orthopaedic centre.

Does computer-assisted surgery benefit leg length restoration in total hip replacement? Navigation versus conventional freehand.

Leg length discrepancy following total hip replacement (THR) can contribute to poor hip function. Abnormal gait, pain, neurological disturbance and patient dissatisfaction have all been described as a result of leg length inequality after THR. The purpose of this study was to determine whether the use of computer navigation in THR can improve limb length restoration and early clinical outcomes.

Relationship between cutting errors and learning curve in computer-assisted total knee replacement.

Computer-assisted total knee replacement (TKR) has been shown to improve radiographic alignment. Continuous feedback from the navigation system allows accurate adjustment of the bone cuts, thus reducing errors. The aim of this study was to determine the impact of experience both with computer navigation and knee replacement surgery on the frequency of errors in intraoperative bone cuts and implant alignment.

Leg length discrepancy, dislocation rate, and offset in total hip replacement using a short modular stem: navigation vs conventional freehand.

We present a match-paired study between computer-assisted and freehand techniques using a short modular femoral stem (Metha; B. Braun Aesculap, Tuttlingen, Germany) in total hip replacement (THR). Surgical time, clinical outcome, dislocation rate, limb length, and offset in 44 patients with ideal indication for this more conservative implant were assessed.

Computer-assisted alignment system for tibial component placement in total knee replacement: a radiological study.

In total knee replacement (TKR), regarding tibial component positioning, almost all implants offer both an intramedullary and an extramedullary alignment guide, leaving it up to the surgeon which guide to use. However, early failure in TKR can be caused by incorrect positioning or orientation with poor limb alignment. Recently computer-based alignment systems have been developed to help the surgeon to overcome these complications.

Mini-incision versus mini-incision and computer-assisted surgery in total knee replacement: a radiological prospective randomised study.

The aim of this trial was to compare the radiological results of 74 patients undergoing a mini-invasive total knee replacement (TKR) using either a traditional alignment guide (MIS group) or a computer assisted alignment system (MICA group). All the patients were prospectively randomised to either group and the same implant was used for both groups. At 8 months post-operatively, the frontal femoral component angle (FFC), the frontal tibial component angle (FTC), the hip-knee-ankle angle (HKA) and the sagittal orientation of components (slopes) were evaluated respectively.

Computer-assisted technique versus intramedullary and extramedullary alignment systems in total knee replacement: a radiological comparison.

Malalignment in total knee replacement (TKR) is frequently associated with earlier failure and poor functional results. The authors compare the radiological results achieved in three consecutive series of TKRs using a computer-based alignment system (38 cases), a totally intramedullary alignment system (40 cases) and a totally extramedullary alignment system (37 cases). The frontal-femoral-component angle (FFC), the frontal-tibial-component angle (FTC), the hip-knee-ankle angle (HKA) and the sagittal orientation of the tibial component (slope) were evaluated 12 months after operation.