The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components. Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.Aims
Methods
Total knee arthroplasty (TKA) femoral components are known to wear and roughen with clinical use, and reaction to metal is a well-documented complication of TKA. Ceramic materials are resistant to wear and corrosion, but the surface wear of ceramic femoral components in TKA has not been reported. This study measured the changes in roughness and mass lost from cobalt-chromium (CoCr) femoral components tested in a knee simulator, and compared them to those observed in ceramic components. Six cast CoCr femoral components were tested in a knee simulator bearing against UHMWPE, with high-kinematics/high-load waveforms. Roughness and scratches were measured via optical profilometry. Scratch volume was equated to mass lost from abrasive wear, while nano-particulate wear and corrosion were estimated from the change in the distance of the surface to the depth of the scratches after increasing numbers of cycles. Three magnesia-stabilized zirconia femoral components that had been wear tested to 15 million cycles were compared with the CoCr components.Introduction
Methods
The results of repair and reconstruction of lesions found in the abductor muscles and tendons during posterior approach to primary total hip arthroplasty (THA) were reported in 2018. During the course of this series it became apparent that the extent of damage in the abductor tendons and muscles usually was obscured by the hypertrophic greater trochanteric bursa, especially the deep layer adherent to the greater trochanter and abductor muscles. The purpose of this study was to evaluate the surgeon's ability to see these lesions during standard posterior approach, and also to describe the dissection necessary to fully expose them. A total of 525 patients (525 hips) underwent primary THA through posterior approach between 2009 and 2013. Fifty-four patients had mild chronic damage to the tendon. Forty-one patients had severe damage with major avulsion of the gluteus medius and minimus muscles.Introduction
Patients and Methods
The aims of this study were to assess the exposure and preservation of the abductor mechanism during primary total hip arthroplasty (THA) using the posterior approach, and to evaluate gluteus maximus transfer to restore abductor function of chronically avulsed gluteus medius and minimus. A total of 519 patients (525 hips) underwent primary THA using the posterior approach, between 2009 and 2013. The patients were reviewed preoperatively and at two and five years postoperatively. Three patients had mild acute laceration of the gluteus medius caused by retraction. A total of 54 patients had mild chronic damage to the tendon (not caused by exposure), which was repaired with sutures through drill holes in the greater trochanter. A total of 41 patients had severe damage with major avulsion of the gluteus medius and minimus muscles, which was repaired with sutures through bone and a gluteus maximus flap transfer to the greater trochanter.Aims
Patients and Methods
Complete or nearly complete disruption of the gluteus attachment is seen in 10–20% of cases at the time of total hip arthroplasty (THA). Special attention is needed to identify the lesion at the time of surgery because the avulsion often is visible only after a thickened hypertrophic trochanteric bursa is removed. The purpose of this study was to evaluate a technique designed to restore abductor function by transferring the gluteus maximus to compensate for the deficient medius and minimus muscles. From Jan 1 2009 to Dec 31 2013, 525 primary THAs were performed by the author. After the components were implanted, the greater trochanteric bursa was removed, and the gluteus medius and minimus attachments to the greater trochanter were visualized and palpated. Ninety-five hips (95 patients) were found to have damaged muscle attachments to bone. Fifty-four hips had mild damage consisting of splits in the tendon, but no frank avulsion of abductor tendon from the bone attachment. None had severe atrophy of the abductor muscles, but all had partial fatty infiltration. All hips with this mild lesion had repair of the tendons with #5 Ticron sutures to repair the tendon bundles together, anchored to the greater trochanter. Forty-one hips had severe damage with complete or nearly complete avulsion of the gluteus medius and minimus muscles from their attachments to the greater trochanter. Thirty-five of these hips had partial fatty infiltration of the abductor muscles, but all responded to electrical stimulation. The surface of the greater trochanter was denuded of soft tissue with a rongeur, the muscles were repaired with five-seven #5 Ticron mattress sutures passed through drill holes in the greater trochanter, and a gluteus maximus flap was transferred to the posterior third of the greater trochanter and sutured under the vastus lateralis. Six hips had complete detachment of the gluteus medius and minimus muscles, severe atrophy of the muscles, and poor response of the muscles to electrical stimulation. The gluteus medius and minimus muscles were sutured to the greater trochanter, and the gluteus maximus flap was transferred. Postoperatively, patients were instructed to protect the hip for 8 weeks, then abductor exercises were started.Introduction
Methods
An extensive review of the spinal and arthroplasty
literature was undertaken to evaluate the effectiveness of local
antibiotic irrigation during surgery. The efficacy of antibiotic
irrigation for the prevention of acute post-operative infection
after total joint arthroplasty was evaluated retrospectively in
2293 arthroplasties (1990 patients) between January 2004 and December
2013. The mean follow-up was 73 months (20 to 139). One surgeon
performed all the procedures with minimal post-operative infection. The intra-operative protocol included an irrigation solution
of normal saline with vancomycin 1000 mg/l and polymyxin 250 000
units/l at the rate of 2 l per hour. No patient required re-admission
for primary infection or further antibiotic treatment. Two morbidly obese
patients (two total hip arthroplasties) developed subcutaneous fat
necrosis requiring debridement and one was revised because the deep
capsular sutures were contaminated by the draining subcutaneous
haematoma. One patient who had undergone total knee arthroplasty
had unrecognised damage to the lateral superior geniculate artery
and developed a haematoma that became infected secondarily four
months after the surgery and underwent revision. The use of antibiotic irrigation during arthroplasty surgery
has been highly effective for the prevention of infection in the
author’s practice. However, it should be understood that any routine
prophylactic use of antibiotics may result in resistant organisms,
and the wise stewardship of the use of antibiotics is an important
part of surgical practice. Cite this article:
Bactericidal levels of antibiotics are difficult
to achieve in infected total joint arthroplasty when intravenous antibiotics
or antibiotic-loaded cement spacers are used, but intra-articular
(IA) delivery of antibiotics has been effective in several studies.
This paper describes a protocol for IA delivery of antibiotics in
infected knee arthroplasty, and summarises the results of a pharmacokinetic
study and two clinical follow-up studies of especially difficult
groups: methicillin-resistant Cite this article:
