The August 2024 Foot & Ankle Roundup360 looks at: ESWT versus surgery for fifth metatarsal stress fractures; Minimally invasive surgery versus open fusion for hallux rigidus; Diabetes and infection risk in total ankle arthroplasty; Is proximal medial gastrocnemius recession useful for managing chronic plantar fasciitis?; Fuse the great toe in the young!; Conservative surgery for diabetic foot osteomyelitis; Mental health and outcome following foot and ankle surgery.
The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes. A retrospective consecutive study of all patients who underwent a rTKA using the fully cemented SMILES rotating hinge prosthesis between 2005 to 2018. Outcome measures included aseptic loosening, reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both prospectively collected local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years.Aims
Methods
Restoration of proximal medial femoral support is the keystone in the treatment of intertrochanteric fractures. None of the available implants are effective in constructing the medial femoral support. Medial sustainable nail (MSN-II) is a novel cephalomedullary nail designed for this. In this study, biomechanical difference between MSN-II and proximal femoral nail anti-rotation (PFNA-II) was compared to determine whether or not MSN-II can effectively reconstruct the medial femoral support. A total of 36 synthetic femur models with simulated intertrochanteric fractures without medial support (AO/OTA 31-A2.3) were assigned to two groups with 18 specimens each for stabilization with MSN-II or PFNA-II. Each group was further divided into three subgroups of six specimens according to different experimental conditions respectively as follows: axial loading test; static torsional test; and cyclic loading test.Aims
Methods
Following a careful in-depth preoperative plan for revision TKA, the first surgical step is adequate exposure. It is crucial to plan your exposure for all contingencies. Prior incisions have tremendous implications and care must be taken to consider their impact. Due to the medially based vascular supply to the skin and superficial tissues about the knee, consideration for use of the most LATERAL incision should be made. It is essential to avoid the development of flaps which may compromise the skin and soft tissue which can have profound implications. Exposure options can be broken down into either PROXIMALLY based techniques or DISTALLY based options. The proximal based techniques involve a medial parapatella arthrotomy followed by the establishment of medial and lateral gutters. An assessment of the ability to evert or subluxate the patella should be made. Care must be taken to protect the insertion of the patella tendon into the tibial tubercle. If the patella is unable to be mobilised, then extension of arthrotomy proximal is performed. If this is not adequate, then consider inside out lateral release. If still unable to mobilise, then a QUAD SNIP is performed. In rare instances, you can connect the lateral release with quad snip resulting in a V-Y quadplasty, which results in excellent exposure. Another option is to employ DISTALLY based techniques such as the tibial tubercle osteotomy technique described by Whiteside. A roughly 8cm osteotomy segment with distal
We studied subchondral intraosseous pressure (IOP) in an animal model during loading, and with vascular occlusion. We explored bone compartmentalization by saline injection. Needles were placed in the femoral condyle and proximal tibia of five anaesthetized rabbits and connected to pressure recorders. The limb was loaded with and without proximal vascular occlusion. An additional subject had simultaneous triple recordings at the femoral head, femoral condyle and proximal tibia. In a further subject, saline injections at three sites were carried out in turn.Objectives
Materials and Methods
The aim of this study was to establish the diagnostic accuracy
of culture of joint aspirate with and without saline injection-reaspiration. This is a retrospective analysis of 580 hip and knee aspirations
in patients who were deemed to have a moderate to high risk of infection,
and who subsequently proceeded to revision arthroplasty over a period
of 12 years. It was carried out at a large quaternary referral centre
where preoperative aspiration is routine.Aims
Patients and Methods
Microindentation has the potential to measure the stiffness of an individual patient’s bone. Bone stiffness plays a crucial role in the press-fit stability of orthopaedic implants. Arming surgeons with accurate bone stiffness information may reduce surgical complications including periprosthetic fractures. The question addressed with this systematic review is whether microindentation can accurately measure cortical bone stiffness. A systematic review of all English language articles using a keyword search was undertaken using Medline, Embase, PubMed, Scopus and Cochrane databases. Studies that only used nanoindentation, cancellous bone or animal tissue were excluded.Objectives
Methods
Performance and durability of total knee arthroplasty is optimised when bone surfaces are prepared with the knee in neutral varus-valgus alignment in the anteroposterior (AP) plane. For the femur, this means resecting the surface perpendicular to the mechanical axis of the femur, which passes through the center of the femoral head and center of the knee. Because the center of the femoral head is not a reliable landmark during the operation, the distal femoral surface can be resected at 5 degrees valgus to the long axis of the femur using an intramedullary (IM) alignment rod to establish the position of the femur's long axis. The IM rod also provides the landmark for alignment of the femoral component in the flexion-extension position. Tibial alignment is established by cutting the upper surface of the tibia perpendicular to the long axis. An extramedullary (EM) rod easily can span the distance between the centers of the tibial surface at the knee and ankle to establish a reference for upper tibial surface resection via the long axis of the tibia. In cases with femoral deformity or bone disease that prevents use of an IM rod as a landmark for the long axis of the femur, plain film radiographs can be used along with intraoperative measurements and hand-held tools that are readily available in the standard total knee instrument set. Using an AP radiograph taken to include the femoral head and knee: 1.) Mark the centers of the femoral head and knee. 2.) Draw a line to connect the centerpoints. 3.) Mark the high points of the medial and lateral femoral condylar joint surfaces. 4.) Draw a line perpendicular to the mechanical axis that crosses the mark on the high point of the most prominent femoral condyle. This marks the position and alignment of the femoral implant surface. 5.) To measure the distal thickness of the femoral component and adding 10% to account for magnification of the radiograph, mark two points proximal to the two high points of the condyles and draw a line perpendicular through these two points to mark the resection line for the distal femoral surfaces. Less than the thickness of the implant will be resected from the least prominent condyle. 6.) Measure the thickness of bone to be resected and the distance between the bone surface and distal surface line. This distance represents the space between the distal femoral cutting guide and the joint surface of the deficient condyle. 7.) Insert a threaded pin into the bone surface with the measured distance protruding from the surface to set this position. 8.) Seat the distal femoral cutting guide against the protruding pin on the low side and against the surface of the femur on the high side. This aligns the distal femoral cutting guide perpendicular to the mechanical axis of the femur. 9.) Draw the AP axis from the center of the intercondylar notch posteriorly to the deepest point of the patellar groove, and use the combined cutting guide to finish the femur. 10.) Make the anterior, posterior, and
Following a careful in-depth preoperative plan for revision TKR, the first surgical step is adequate exposure. The following steps should be considered: 1.) Prior incisions: due to the medially based vascular supply to the skin and superficial tissues about the knee, consideration for use of the most LATERAL incision should be made. 2.) Avoid the use of flaps which may compromise the skin and soft tissue. 3.) Exposure options can be broken down into: PROXIMALLY based techniques: medial parapatella arthrotomy, establish medial and lateral gutters, eversion or subluxation of the patella, extension of arthrotomy proximal, if unable to “mobilise” patella, consider inside out lateral release, if still unable to mobilise: QUAD SNIP, in rare instances, connect lateral release with quad snip resulting in a V-Y quadplasty, may now turn down for excellent exposure. DISTALLY based techniques: tibial tubercle osteotomy technique described by Whiteside, roughly 8 cm osteotomy segment with distal
Performance and durability of total knee arthroplasty is optimised when bone surfaces are prepared with the knee in neutral varus-valgus alignment in the anteroposterior (AP) plane. For the femur, this means resecting the surface perpendicular to the mechanical axis of the femur, which passes through the center of the femoral head and center of the knee. Because the center of the femoral head is not a reliable landmark during the operation, the distal femoral surface can be resected at 5 degrees valgus to the long axis of the femur using an intramedullary (IM) alignment rod to establish the position of the femur's long axis. The IM rod also provides the landmark for alignment of the femoral component in the flexion-extension position. Tibial alignment is established by cutting the upper surface of the tibia perpendicular to the long axis. An IM rod is not necessary for alignment since the ankle is accessible for reference. An extramedullary (EM) rod easily can span the distance between the centers of the tibial surface at the knee and ankle to establish a reference for upper tibial surface resection via the long axis of the tibia. In cases with femoral deformity or bone disease that prevents use of an IM rod as a landmark for the long axis of the femur, computer-assisted alignment can be helpful to establish the mechanical axis of the femur and to determine the level of resection of the femoral surface to create a plane that is perpendicular to the mechanical axis of the femur and positioned to place the joint surface at the correct level. Whereas this can be done with CT scan or MRI imaging and robotic instrumentation, the cost in time and money is substantial. Rather, plane film radiographs can be used along with intra-operative measurements and hand-held tools that are readily available in the standard total knee instrument set. Using an AP radiograph taken to include the femoral head and knee: Mark the centers of the femoral head and knee. Draw a line to connect the centerpoints. Mark the high points of the medial and lateral femoral condylar joint surfaces. Draw a line perpendicular to the mechanical axis that crosses the mark on the high point of the most prominent femoral condyle. This line marks the position and alignment of the femoral implant surface. Next, measure the distal thickness of the femoral component and add 10% to account for magnification of the radiograph. Draw a parallel line this distance proximal to the femoral surface line. This is the femoral resection line. Less than the thickness of the implant will be resected from the least prominent condyle. On the low side, measure the thickness of bone to be resected and the distance between the bone surface and distal surface line. Insert a threaded pin into the bone surface with the measured distance protruding from the surface to set this position. Seat the distal femoral cutting guide against the protruding pin and against the surface of the femur on the high side. Resect with the cutting guide fixed perpendicular to the long axis of the femur. This resects the thickness of the implant from the prominent side and resects the prescribed amount from the low side to set the distal cut perpendicular to the mechanical axis of the femur. Draw the AP axis from the center of the intercondylar notch posteriorly to the deepest point of the patellar groove, and use the combined cutting guide to finish the femur. Make the anterior, posterior, and
Use of “CPR” distance has proven clinical utility in stratifying risks of “steep cups” in MOM failures.[1, 4] The CPR indice has been defined as distance between point of intersection of the hip reaction force (Fig. 1: vector-R in contact patch) and closest point on the inner cup rim.[4] However, the CPR indice has limitations. It assumes that, (1) the hip load-vector (R) will be angled 10°-medial in all patients, (2) the contact patch will be same size in all patients, and (3) the contact patch will be invariant with increasing MOM diameter. In contrast it is known from retrieval studies that larger MOM bearings created much larger wear patches.[3] Furthermore, the size of cup wear-patches in MOM bearings can now be estimated with some certainty using simulator wear data.[2] Our objective was to develop an algorithm that would predict (i) contact-patch size for all cup designs and diameters, (ii) determine actual margin of safety (Fig. 1: MOS) for different laterally-inclined cups, and (iii) predict critical test angles for “steep” cup studies in hip simulators. The ‘CPR-distance’ (Fig. 1) is subtended by the CPA angle, but the true margin of safety is the distance from edge of wear patch to cup rim, indicated here by MOS angle. In this algorithm the wear-patch size (CAP angle) is a key parameter, as derived from MOM wear data (Fig. 2). The CAP angles decrease with increasing MOM diameter, as defined by strong linear trend (R=0.998). The key 2nd parameter is cup inclination angle that juxtaposes the wear-pattern to the cup rim (CCI). For hemispherical cups the critical inclination is given by CCI = 90 – CAP/2, where articulation angle ABA = 180o. The cup bearing-surface is typically reduced < 180o(sub-hemispherical profile, instrumentation groove, rim
A 35-year-old female (age 35Yrs) had primary MOM total hip arthroplasty (THA) in 2008. At 8 months this patient postoperatively developed headaches, memory loss, vertigo, and aura-like symptoms that progressed to seizures. At 18 months review, she complained of progressive hip pain, a popping sensation and crepitus with joint motion. This patient weighed 284lbs with BMI of 38.5. Radiographs revealed the cup had 55° inclination, 39° anteversion (Fig. 1). Metal ion concentrations were high (blood: Co=126 mcg/L, Cr= 64mcg/L). Revision was performed in November 2010 A dark, serous fluid was observed, along with synovitis. The implants were well fixed and the femoral head could not be removed; thus the stem was removed by femoral osteotomy. With the head fused on this femoral stem, for the 1. st. time it was possible to precisely determine the habitual patterns of MOM wear relative to her in-vivo function. We investigated (1) size and location of wear patterns and (2) signs of cup-stem impingement to help explain her symptoms developed over 32 months follow-up. The retrieved MOM was a Magnum™ with head diameter 50mm and 50×56mm cup (Biomet). This was mounted on a Taperloc™ lateralized porous-coated stem. Components were examined visually and wear damage mapped by stereo-microscopy, interferometry, CMM, SEM, and EDS. Main-wear zone (MWZ) areas were calculated using standard spherical equations. 1. and centroidal vectors determined. The head-cup mismatch was 427um with the cup revealing a form factor of 228um. The cup showed wear area of 1275mm² that extended up to the cup rim over 150°arc. The cup rim was worn thin over a 90° arc with loss of cup
Minimal or Less Invasive Approaches. Limited medial parapatellar incision – 2–3 inch medial incision; Best for unicompartmental implant; patellar visualization poor; Less invasive but limited visualization therefore overall joint inspection is compromised. MIS TKR approaches - Mini midvastus approach popularised by S.B. Haas - Ideal BMI 30 or less; Incision length 10cm; Vastus incision about 2–3cm; Vastus incision beyond 5–6cm places motor branch to VMO at risk; Coupled with downsized cutting blocks, allows predictable ability to perform TKR; Sliding window concept; Patella eversion not necessary. Mid Subvastus approach – 10cm skin incision; Sub vastus dissection up to septum (watch for bleeders!); VERY difficult in muscular males!. Standard Incisions. Standard medial parapatellar approach - Familiar to most surgeons; Medial arthrotomy facilitates exposure for almost all procedures; Can become more extensile by incising the quad tendon further proximal; Release of posteromedial capsule and semi-membraneosus allows exposure posteriorly. Quad snip - Used occasionally in the fixed varus, flexion contracted knee; More commonly used in revisions; Allows patella eversion without risk of distal avulsion; Motor strength appears to return to baseline level postoperatively. V-Y quadriceps turndown - Technique: initial medial parapatellar arthrotomy, an oblique tenotomy angled toward the tendinous portion of the vastus lateralis and then extended distally; The quadriceps segment is than retracted downward to expose the joint; Tenotomy is closed with robust non-absorbable sutures holding the knee in extension; Postoperative flexion is dictated by integrity of repair while flexing knee at time of closure. Disadvantages include extensor lag, as well as effecting ultimate ROM. Tibial tubercle osteotomy a la Whiteside - Medial arthrotomy; Tubercle segment is 6–8cm long, 2cm wide and 1–1.5cm thick; Segment is
At least four ways have been described to determine
femoral component rotation, and three ways to determine tibial component
rotation in total knee replacement (TKR). Each method has its advocates
and each has an influence on knee kinematics and the ultimate short
and long term success of TKR. Of the four femoral component methods,
the author prefers rotating the femoral component in flexion to
that amount that establishes a stable symmetrical flexion gap. This
judgement is made after the soft tissues of the knee have been balanced
in extension. Of the three tibial component methods, the author prefers rotating
the tibial component into congruency with the established femoral
component rotation with the knee is in extension. This yields a
rotationally congruent articulation during weight-bearing and should
minimise the torsional forces being transferred through a conforming tibial
insert, which could lead to wear to the underside of the tibial
polyethylene. Rotating platform components will compensate for any
mal-rotation, but can still lead to pain if excessive tibial insert
rotation causes soft-tissue impingement. Cite this article:
Disruption of the extensor mechanism in total
knee arthroplasty may occur by tubercle avulsion, patellar or quadriceps
tendon rupture, or patella fracture, and whether occurring intra-operatively
or post-operatively can be difficult to manage and is associated
with a significant rate of failure and associated complications.
This surgery is frequently performed in compromised tissues, and
repairs must frequently be protected with cerclage wiring and/or
augmentation with local tendon (semi-tendinosis, gracilis) which
may also be used to treat soft-tissue loss in the face of chronic
disruption. Quadriceps rupture may be treated with conservative
therapy if the patient retains active extension. Component loosening
or loss of active extension of 20° or greater are clear indications
for surgical treatment of patellar fracture. Acute patellar tendon
disruption may be treated by primary repair. Chronic extensor failure
is often complicated by tissue loss and retraction can be treated
with medial gastrocnemius flaps, achilles tendon allografts, and
complete extensor mechanism allografts. Attention to fixing the
graft in full extension is mandatory to prevent severe extensor
lag as the graft stretches out over time.
Over recent years hip arthroscopic surgery has
evolved into one of the most rapidly expanding fields in orthopaedic surgery.
Complications are largely transient and incidences between 0.5%
and 6.4% have been reported. However, major complications can and
do occur. This article analyses the reported complications and makes recommendations
based on the literature review and personal experience on how to
minimise them.
Modification of ordinary jig (angle guide) used for DCS fixation so as to make it more suitable for biological DCS. We have modified the jig used for ordinary DCS fixation so as to make it more suitable for biological DCS. In ordinary DCS jig, the hole for guide wire lies towards one end and the handle is attached at the other end. We have removed the handle and attached it adjacent to hole for guide pin so that the other end is free and can be slided in submuscular plane without actually exposing the whole length of femur. Subsequently, we
The zona conoidea comprises the area of the lateral
trochlear ridge of the humerus. The purpose of this study is to reintroduce
this term ‘zona conoidea’ to the discussion of the human elbow and
to investigate its significance in the development of osteoarthritis
of the elbow. The upper extremities of 12 cadavers were prepared. With the
forearm in neutral, pronation and supination, the distance between
the