We aimed to evaluate the temperature around the nerve root during drilling of the lamina and to
determine whether irrigation during drilling can reduce the chance of nerve root injury. Lumbar nerve roots were exposed to frictional heat by high-speed drilling of the lamina in a live
rabbit model, with saline (room temperature (RT) or chilled saline) or without saline (control)
irrigation. We measured temperatures surrounding the nerve root and made histological
evaluations.Aims
Materials and Methods
Objectives. Prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty. Non-contact induction heating of metal implants is a new and emerging treatment for PJI. However, there may be concerns for potential tissue necrosis. It is thought that segmental induction heating can be used to control the thermal dose and to limit collateral
According to the latest report from the German Arthroplasty Registry, aseptic loosening is the primary cause of implant failure following primary hip arthroplasty. Osteolysis of the proximal femur due to the stress-shielding of the bone by the implant causes loss of fixation of the proximal femoral stem, while the distal stem remains fixed. Removing a fixed stem is a challenging process. Current removal methods rely on manual tools such as chisels, burrs, osteotomes, drills and mills, which pose the risk of bone fracture and cortical perforation. Others such as ultrasound and laser, generate temperatures that could cause
Purpose:. Tuberosity healing in hemiarthroplasty for proximal humerus fractures remains problematic. Improved implant design and better techniques for tuberosity fixation have not been met with improved clinical results. The etiology for tuberosity failure is multifactorial; however
Introduction: The curing of polymethylmethacrylate cement is an exothermic reaction, with temperatures reaching 80oC. Thus contact with cement can result in
Bone cement reaches high temperatures while polymerising. Bone has been shown to be sensitive to
The well-fixed cemented femoral stem and surrounding cement can be challenging to remove. Success requires evaluation of the quality of the cement mantle (interface lucency), position of the stem, extent of cement below the tip of the stem and skill with the specialised instruments and techniques needed to remove the stem and cement without perforating the femur. Smooth surfaced stems can usually be easily removed from the surrounding cement mantle with a variety of stem extractors that attach to the trunnion or an extraction hole on the implant. Roughened stems can be freed from the surrounding cement mantle with osteotomes or a narrow high speed burr and then extracted with the above instruments. Following this, the well-fixed cement mantle needs to be removed. Adequate exposure and visualization of the cement column is essential to remove the well-fixed cement without damage to the bone in the femur. This is important since fixation of a revision femoral component typically requires at least 4 cm of contact with supportive cortical bone, which can be difficult to obtain if the femur is perforated or if the isthmus damaged. Proximally, cement in the metaphyseal region can be thinned with a high speed burr, then split radially and removed piecemeal. It is essential to remember that both osteotomes and high speed burrs will cut thru bone easier than cement and use of these instruments poses a substantial risk of unintended bone removal and perforation of the femur if done improperly. These instruments should, as a result, be used under direct vision. Removal of more distal cement in the femur typically requires use of an extended femoral osteotomy (ETO) to allow for adequate access to the well-fixed cement in the bowed femoral canal. An ETO also facilitates more efficient removal of cement in the proximal femur. The ETO should be carefully planned so that it is distal enough to allow for access to the end of the cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation since the straight cement removal instruments cannot negotiate the bowed femoral canal to access the end of the cement column without risk of perforation. An ETO that is too distal makes cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. Cement below the level of the ETO cannot be directly visualised and specialised instruments are necessary to safely remove this distal cement. Radiofrequency cement removal devices use high frequency (ultrasonic) radio waves to melt the cement within the canal. Although cement removal with these devices is time consuming and tedious, they do substantially reduce the chances of femoral perforation. These devices can, however, generate considerable heat locally and can result in
Two protocols for the operative technique and care of the pin-site with external fixation were compared prospectively. There was a total of 120 patients with 46 in group A and 74 in group B. Infection was defined as an episode of pain or inflammation at a pin site, accompanied by a discharge which was either positive on bacterial culture or responded to a course of antibiotics. Patients in group B had a lower proportion of infected pin sites (p = 0.003) and the time to the first episode of infection was longer (p <
0.001). The risk of pin-site infection is lower if attention is paid to avoiding
Twenty patients were examined by standard radiography and roentgen stereophotogrammetric analysis (RSA) during a two-year period after total hip arthroplasty. Eleven of the acetabular components migrated cranially and three femoral components migrated distally. This migration was most rapid during the first four months after operation. Our findings support the possibility that mechanical loosening is initiated by
Fatigue fractures which originate at stress-concentrating voids located at the implant-cement interface are a potential cause of septic loosening of cemented femoral components. Heating of the component to 44°C is known to reduce the porosity of the cement-prosthesis interface. The temperature of the cement-bone interface was recorded intra-operatively as 32.3°C. A simulated femoral model was devised to study the effect of heating of the component on the implant-cement interface. Heating of the implant and vacuum mixing have a synergistic effect on the porosity of the implant-cement interface, and heating also reverses the gradients of microhardness in the mantle. Heating of the implant also reduces porosity at the interface depending on the temperature. A minimum difference in temperature between the implant and the bone of 3°C was required to produce this effect. The optimal difference was 7°C, representing a balance between maximal reduction of porosity and an increased risk of
We studied the various drill bits available for engineering purposes, and compared them with standard orthopaedic drill bits, using continuous temperature recording at 0.5 mm, 1.0 mm and 1.5 mm from the edge of a 2.5 mm hole as it was drilled in fresh cadaver human tibia. We found that some commercially available drill bits performed better than their orthopaedic equivalents, producing significantly less
The risk of postoperative complications after resection of soft-tissue sarcoma in the medial thigh is higher than in other locations. This study investigated whether a vessel sealing system (VSS) could help reduce the risk of postoperative complications after wide resection of soft-tissue sarcoma in the medial thigh. Of 285 patients who underwent wide resection for soft-tissue sarcoma between 2014 and 2021 at our institution, 78 patients with tumours in the medial thigh were extracted from our database. Information on clinicopathological characteristics, preoperative treatment, surgical treatment (use of VSS, blood loss volume, operating time), and postoperative course (complications, postoperative haemoglobin changes, total drainage volume, and drainage and hospitalization durations) were obtained from medical records. We statistically compared clinical outcomes between patients whose surgery did or did not use VSS (VSS and non-VSS groups, respectively).Aims
Methods
Electromagnetic induction heating has demonstrated in vitro antibacterial efficacy over biofilms on metallic biomaterials, although no in vivo studies have been published. Assessment of side effects, including thermal necrosis of adjacent tissue, would determine transferability into clinical practice. Our goal was to assess bone necrosis and antibacterial efficacy of induction heating on biofilm-infected implants in an in vivo setting. Titanium-aluminium-vanadium (Ti6Al4V) screws were implanted in medial condyle of New Zealand giant rabbit knee. Study intervention consisted of induction heating of the screw head up to 70°C for 3.5 minutes after implantation using a portable device. Both knees were implanted, and induction heating was applied unilaterally keeping contralateral knee as paired control. Sterile screws were implanted in six rabbits, while the other six received screws coated with Aims
Methods
The well-fixed cemented femoral stem and surrounding cement can be challenging to remove. Success requires evaluation of the quality of the cement mantle (interface lucency), position of the stem, extent of cement below the tip of the stem and skill with the specialised instruments and techniques needed to remove the stem and cement without perforating the femur. Smooth surfaced stems can usually be easily removed from the surrounding cement mantle with a variety of stem extractors that attach to the trunnion or an extraction hole on the implant. Roughened stems can be freed from the surrounding cement mantle with osteotomes or a narrow high speed burr and then extracted with the above instruments. Following this, the well fixed cement mantle needs to be removed. Adequate exposure and visualization of the cement column is essential to remove the well-fixed cement without damage to the bone in the femur. This is important since fixation of a revision femoral component typically requires at least 4cm of contact with supportive cortical bone, which can be difficult to obtain if the femur is perforated or if the isthmus damaged. Proximally, cement in the metaphyseal region can be thinned with a high speed burr, then split radially and removed piecemeal. It is essential to remember that both osteotomes and high speed burrs will cut thru bone easier than cement and use of these instruments poses a substantial risk of unintended bone removal and perforation of the femur if done improperly. These instruments should, as a result, be used under direct vision. Removal of more distal cement in the femur typically requires use of an extended femoral osteotomy (ETO) to allow for adequate access to the well-fixed cement in the bowed femoral canal. An ETO also facilitates more efficient removal of cement in the proximal femur. The ETO should be carefully planned so that it is distal enough to allow for access to the end of the cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation since the straight cement removal instruments cannot negotiate the bowed femoral canal to access the end of the cement column without risk of perforation. An ETO that is too distal makes cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. Cement below the level of the ETO cannot be directly visualised and specialised instruments are necessary to safely remove this distal cement. Radiofrequency cement removal devices (OSCAR) use high frequency (ultrasonic) radio waves to melt the cement within the canal. Although cement removal with these devices is time consuming and tedious, they do substantially reduce the chances of femoral perforation. These devices can, however, generate considerable heat locally and can result in
The causes of a stiff elbow are numerous including: post-traumatic elbow, burns, head injury, osteoarthritis, inflammatory joint disease and congenital. Types of stiffness include: loss of elbow flexion, loss of elbow extension and loss of forearm rotation. All three have different prognoses in terms of the timing of surgery and the likelihood of restoration of function. Contractures can be classified into extrinsic and intrinsic (all intrinsic develop some extrinsic component). Functional impairment can be assessed medicolegally; however, in clinical practice the patient puts an individual value on the arc of motion. Objectively most functions can be undertaken with an arc of 30 to 130 degrees. The commonest cause of a Post-traumatic Stiff elbow is a radial head fracture or a complex fracture dislocation. Risk factors for stiffness include length of immobilisation, associated fracture with dislocation, intra-articular derangement, delayed surgical treatment, associated head injury, heterotopic ossification. Early restoration of bony columns and joint stability to allow early mobilisation reduces incidence of joint stiffness. Heterotopic ossification (HO) is common in fracture dislocation of the elbow. Neural Axis trauma alone causes HO in elbows in 5%. However, combined neural trauma and elbow trauma the incidence is 89%. Stiffness due to
During revision hip surgery, damage to the sciatic nerve is due most commonly to excessive tension. While the nerve is strong in tension and is able to tolerate this remarkably, it is sensitive to lateral compression against angled structures and it is likely that tension causes injury by such pressure. In a personal series of 441 revision hip procedures, sciatic nerve injury occurred in 9 recognised cases:. 2 were complete with no useful recovery. 2 were severe with some incomplete recovery. 3 were predominantly lateral popliteal with incomplete recovery. 2 were transient and clinically fully recovered. In only two of these were the cause and the time of injury identifiable. In these cases, pain was not a serious feature but in eight separate medico-legal cases, burning pain of variable distribution has been the most serious complaint. Medical negligence has been successfully sustained on the grounds of res ipsa locitur. Regrettably, patients must be given informed consent with yet another potential hazard being listed. We have found that in normal individuals the range of straight leg raising varies between 30 and 90 degrees. Towards the limit of this range the nerve is tight and a crude cadaveric test indicated a tension force of 40 newtons! In an athlete this may be extreme and yet the nerve does not complain. Excluding direct compression (e.g. by a retractor) and
Injection of PMMA bone cement into fractured vertebral bodies has been used clinically and proved to be effective. However, there are concerns about
Introduction: Knee arthroscopy is one of the most commonly performed orthopaedic procedures. All orthopaedic surgeons have heard anecdotal stories of
Hallux valgus (HV) presents as a common forefoot deformity that causes problems with pain, mobility, footwear, and quality of life. The most common open correction used in the UK is the Scarf and Akin osteotomy, which has good clinical and radiological outcomes and high levels of patient satisfaction when used to treat a varying degrees of deformity. However, there are concerns regarding recurrence rates and long-term outcomes. Minimally invasive or percutaneous surgery (MIS) has gained popularity, offering the potential for similar clinical and radiological outcomes with reduced postoperative pain and smaller scars. Despite this, MIS techniques vary widely, hindering comparison and standardization. This review evaluates the evidence for both open Scarf and Akin osteotomy and newer-generation MIS techniques. Fourth-generation MIS emphasizes multiplanar rotational deformity correction through stable fixation. While MIS techniques show promise, their evidence mainly comprises single-surgeon case series. Comparative studies between open and MIS techniques suggest similar clinical and radiological outcomes, although MIS may offer advantages in scar length and less early postoperative pain. MIS may afford superior correction in severe deformity and lower recurrence rates due to correcting the bony deformity rather than soft-tissue correction. Recurrence remains a challenge in HV surgery, necessitating long-term follow-up and standardized outcome measures for assessment. Any comparison between the techniques requires comparative studies. Surgeons must weigh the advantages and risks of both open and MIS approaches in collaboration with patients to determine the most suitable treatment. Cite this article: