Aims. It has been hypothesized that proximal radial neck resorption (PRNR) following press-fit radial head arthroplasty (RHA) is due to
The aim of this study was to analyze how proximal radial neck resorption (PRNR) starts and progresses radiologically in two types of press-fit radial head arthroplasties (RHAs), and to investigate its clinical relevance. A total of 97 patients with RHA were analyzed: 56 received a bipolar RHA (Group 1) while 41 received an anatomical implant (Group 2). Radiographs were performed postoperatively and after three, six, nine, and 12 weeks, six, nine, 12, 18, and 24 months, and annually thereafter. PRNR was measured in all radiographs in the four radial neck quadrants. The Mayo Elbow Performance Score (MEPS), the abbreviated version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the patient-assessed American Shoulder and Elbow Surgeons score - Elbow (pASES-E) were used for the clinical assessment. Radiological signs of implant loosening were investigated.Aims
Methods
Revision surgery of the hip was performed on 114 hips using an extensively porous-coated femoral component. Of these, 95 hips (94 patients) had a mean follow-up of 10.2 years (5 to 17). No cortical struts were used and the cortical index and the femoral cortical width were measured at different levels. There were two revisions for aseptic loosening. Survivorship at 12 years for all causes of failure was 96.9% (95% confidence interval 93.5 to 100) in the best-case scenario. Fibrous or unstable fixation was associated with major bone defects. The cortical index (p = 0.045) and the lateral cortical thickness (p = 0.008) decreased at the proximal level over time while the medial cortex increased (p = 0.001) at the proximal and distal levels. An increase in the proximal medial cortex was found in patients with an extended transtrochanteric osteotomy (p = 0.026) and in those with components shorter than 25 cm (p = 0.008). The use of the extensively porous-coated femoral component can provide a solution for difficult cases in revision surgery. Radiological bony ingrowth is common. Although without clinical relevance at the end of follow-up, the thickness of the medial femoral cortex often increased while that of the lateral cortex decreased. In cases in which a shorter component was used and in those undertaken using an extended trochanteric osteotomy, there was a greater increase in thickness of the femoral cortex over time.
Aims. This study aimed to identify the effect of anatomical tibial component (ATC) design on load distribution in the periprosthetic tibial bone of Koreans using finite element analysis (FEA). Methods. 3D finite element models of 30 tibiae in Korean women were created. A symmetric tibial component (STC, NexGen LPS-Flex) and an ATC (Persona) were used in surgical simulation. We compared the FEA measurements (von Mises stress and principal strains) around the stem tip and in the medial half of the proximal tibial bone, as well as the distance from the distal stem tip to the shortest anteromedial cortical bone. Correlations between this distance and FEA measurements were then analyzed. Results. The distance from the distal stem tip to the shortest cortical bone showed no statistically significant difference between implants. However, the peak von Mises stress around the distal stem tip was higher with STC than with ATC. In the medial half of the proximal tibial bone: 1) the mean von Mises stress, maximum principal strain, and minimum principal strain were higher with ATC; 2) ATC showed a positive correlation between the distance and mean von Mises stress; 3) ATC showed a negative correlation between the distance and mean minimum principal strain; and 4) STC showed no correlation between the distance and mean measurements. Conclusion. Implant design affects the load distribution on the periprosthetic tibial bone, and ATC can be more advantageous in preventing
The October 2023 Shoulder & Elbow Roundup. 360. looks at: Arthroscopic capsular shift surgery in patients with atraumatic shoulder joint instability: a randomized, placebo-controlled trial; Superior capsular reconstruction partially restores native glenohumeral loads in a dynamic model; Gene expression in glenoid articular cartilage varies in acute instability, chronic instability, and osteoarthritis; Intra-articular injection versus interscalene brachial plexus block for acute-phase postoperative pain management after arthroscopic shoulder surgery; Level of pain catastrophizing rehab in subacromial impingement: secondary analyses from a pragmatic randomized controlled trial (the SExSI Trial); Anterosuperior versus deltopectoral approach for primary reverse total shoulder arthroplasty: a study of 3,902 cases from the Dutch National Arthroplasty Registry with a minimum follow-up of five years; Assessment of progression and clinical relevance of
Aims. The aim of this study was to compare the mid-term patient-reported outcome, bone remodelling, and migration of a short stem (Collum Femoris Preserving; CFP) with a conventional uncemented stem (Corail). Methods. Of 81 patients who were initially enrolled, 71 were available at five years’ follow-up. The outcomes at two years have previously been reported. The primary outcome measure was the clinical result assessed using the Oxford Hip Score (OHS). Secondary outcomes were the migration of the stem, measured using radiostereometric analysis (RSA), change of bone mineral density (BMD) around the stem, the development of radiolucent lines, and additional patient-reported outcome measures (PROMs). Results. There were no statistically significant differences between the groups regarding PROMs (median OHS (CFP 45 (interquartile range (IQR) 35 to 48); Corail 45 (IQR 40 to 48); p = 0.568). RSA showed stable stems in both groups, with little or no further subsidence between two and five years. Resorption of the femoral neck was evident in nine patients in the CFP group and in none of the 15 Corail stems with a collar that could be studied. Dual X-ray absorbiometry showed a significantly higher loss of BMD in the proximal Gruen zones in the CFP group (mean changes in BMD: Gruen zone 1, CFP -9.5 (95% confidence interval (CI) -14.8 to -4.2), Corail 1.0 (95% CI 3.4 to 5.4); Gruen zone 7, CFP -23.0 (95% CI -29.4 to -16.6), Corail -7.2 (95% CI -15.9 to 1.4). Two CFP stems were revised before two years’ follow-up due to loosening, and one Corail stem was revised after two years due to chronic infection. Conclusion. The CFP stem has a similar clinical outcome and subsidence pattern when compared with the Corail stem. More pronounced proximal
We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce
Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF. Cite this article:
Proximal femur fractures treatment can involve anterograde nailing with a single or double cephalic screw. An undesirable failure for this fixation is screw cut-out. In a single-screw nail, a tip-apex distance (TAD) greater than 25 mm has been associated with an increased risk of cut-out. The aim of the study was to examine the role of TAD as a risk factor in a cephalic double-screw nail. A retrospective study was conducted on 112 patients treated for intertrochanteric femur fracture with a double proximal screw nail (Endovis BA2; EBA2) from January to September 2021. The analyzed variables were age, sex, BMI, comorbidities, fracture type, side, time of surgery, quality of reduction, pre-existing therapy with bisphosphonate for osteoporosis, screw placement in two different views, and TAD. The last follow-up was at 12 months. Logistic regression was used to study the potential factors of screw cut-out, and receiver operating characteristic curve to identify the threshold value.Aims
Methods
The use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up. Outcomes of 143 procedures undertaken for all indications in 131 patients were reviewed, with subset analysis of those for osteoarthritis (OA) (n = 99). The primary outcome was the Oxford Shoulder Score (OSS) at a minimum of five years. Secondary outcomes were ranges of motion and radiological analysis of humeral radiolucency, rotator cuff failure, and glenoid loosening.Aims
Methods
Multiple secondary surgical procedures of the shoulder, such as soft-tissue releases, tendon transfers, and osteotomies, are described in brachial plexus birth palsy (BPBP) patients. The long-term functional outcomes of these procedures described in the literature are inconclusive. We aimed to analyze the literature looking for a consensus on treatment options. A systematic literature search in healthcare databases (PubMed, Embase, the Cochrane library, CINAHL, and Web of Science) was performed from January 2000 to July 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The quality of the included studies was assessed with the Cochrane ROBINS-I risk of bias tool. Relevant trials studying BPBP with at least five years of follow-up and describing functional outcome were included.Aims
Methods
Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs. In total, 34 patients (13 female, 21 male; mean age 62 years (41 to 79); BMI 29.7 kg/m2 (23.6 to 42.1)) with 38 medial Oxford partial UKAs (20 left, 18 right; 19 cementless, 14 cemented, and five hybrid) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively, and at one and two years postoperatively. Changes in mean osteoblastic activity were investigated using a tracer localization scheme with volumes of interest (VOIs), reported by normalized mean tracer values. A SPECT/CT registration platform additionally explored cortical tracer evolution in zones of interest identified by previous experimental research.Aims
Methods
In 44 consecutive patients, 60 porous-coated anatomic total knee (PCA) prostheses with a porous-coated central tibial stem were implanted without using cement. The clinical results and bony remodelling have been assessed after five years' follow-up. The average Hospital for Special Surgery knee score was 33.1 before operation and 95.7 at the latest follow-up, while the average range of movement improved from 63 degrees to 123 degrees. No subsidence or migration of the components was seen. A radiodense line appeared around the components at six months to one year after the operation and became more dense with time. There was no evidence of bone resorption related to
We enrolled 98 patients (107 hips) with a mean age of 47 years (SD 8.6) into a prospective study of the Madreporic Lord THR; 34 hips had primary and 73 secondary osteoarthritis. After ten years, the survival rate using revision as the endpoint for failure was 70% (±9) for the cup and 98% (±0.3) for the stem. The combined clinical and radiological survival rates were 46% (±11) and 81% (±10), respectively. Osteoporosis due to
Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population. This is a retrospective radiological study conducted in Japan. Radiological assessment was done in accordance with predetermined radiological review protocol. A total of 241 hips were included in the study and 118 hips (49.0%) revealed radiological change from immediately after surgery to one year postoperatively; these 118 hips were eligible for further analyses. Each investigator screened whether either radiolucent lines (RLLs), cortical hypertrophy (CH), or atrophy (AT) appeared or not on the one-year radiograph. Further, three-year radiographs of eligible cases were reviewed to determine changes such as, disappeared (D), improved (I), stable (S), and progression (P). Additionally, bone condensation (BC) was assessed on the three-year radiograph.Aims
Methods
Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes. In this prospective cohort study, radiostereometric analysis (RSA) radiographs were obtained in 24 patients at one day, six weeks, six months, one year, and two years postoperatively. Migration was calculated using model-based RSA. Clinical outcomes were evaluated using the visual analogue scale (VAS), the Oxford Shoulder Score (OSS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) score.Aims
Methods
From 1986 to 1991 we fitted 20 children with endoprostheses after resection of malignant bone tumours of the leg; six have reached skeletal maturity and are the subject of this study. Reconstruction of defects in growing limbs in which the eventual shortening can be predicted requires the use of extendable prostheses. The mean age at operation was 11 years (9.2 to 13.7) and the average follow-up period was 6.3 years (4.3 to 7.6). The diagnosis was osteosarcoma in five patients and Ewing's sarcoma in one. All tumours were Enneking stage-IIB. When seen for follow-up all patients were free from disease. The extendable implants used included the Pafford-Lewis prosthesis and the Kotz Modular Femur Tibia Reconstruction system with a compatible, newly-designed growth module. Telescope-like elongation of the prostheses was performed by insertion of a screwdriver through a small skin incision. Active epiphyseal growth in the adjacent growth plate was preserved by using prosthetic stems with a smooth surface. The mean length gained was 13.15 cm (4.5 to 19.5) requiring 53 planned procedures. Seven revision operations were necessary for complications. Functional evaluation showed excellent and good results in all cases.
Distraction osteogenesis (DO) is a useful orthopaedic procedure employed to lengthen and reshape bones by stimulating bone formation through controlled slow stretching force. Despite its promising applications, difficulties are still encountered. Our previous study demonstrated that pulsed electromagnetic field (PEMF) treatment significantly enhances bone mineralization and neovascularization, suggesting its potential application. The current study compared a new, high slew rate (HSR) PEMF signal, with different treatment durations, with the standard Food and Drug Administration (FDA)-approved signal, to determine if HSR PEMF is a better alternative for bone formation augmentation. The effects of a HSR PEMF signal with three daily treatment durations (0.5, one, and three hours/day) were investigated in an established rat DO model with comparison of an FDA-approved classic signal (three hrs/day). PEMF treatments were applied to the rats daily for 35 days, starting from the distraction phase until termination. Radiography, micro-CT (μCT), biomechanical tests, and histological examinations were employed to evaluate the quality of bone formation.Aims
Methods
The aim of this study was to investigate whether wear and backside deformation of polyethylene (PE) tibial inserts may influence the cement cover of tibial trays of explanted total knee arthroplasties (TKAs). At our retrieval centre, we measured changes in the wear and deformation of PE inserts using coordinate measuring machines and light microscopy. The amount of cement cover on the backside of tibial trays was quantified as a percentage of the total surface. The study involved data from the explanted fixed-bearing components of four widely used contemporary designs of TKA (Attune, NexGen, Press Fit Condylar (PFC), and Triathlon), revised for any indication, and we compared them with components that used previous generations of PE. Regression modelling was used to identify variables related to the amount of cement cover on the retrieved trays.Aims
Methods
There are concerns regarding initial stability and early periprosthetic fractures in cementless hip arthroplasty using short stems. This study aimed to investigate stress on the cortical bone around the stem and micromotions between the stem and cortical bone according to femoral stem length and positioning. In total, 12 femoral finite element models (FEMs) were constructed and tested in walking and stair-climbing. Femoral stems of three different lengths and two different positions were simulated, assuming press-fit fixation within each FEM. Stress on the cortical bone and micromotions between the stem and bone were measured in each condition.Aims
Methods
Although bone cement is the primary mode of fixation in total knee arthroplasty (TKA), cementless fixation is gaining interest as it has the potential of achieving lasting biological fixation. By 3D printing an implant, highly porous structures can be manufactured, promoting osseointegration into the implant to prevent aseptic loosening. This study compares the migration of cementless, 3D-printed TKA to cemented TKA of a similar design up to two years of follow-up using radiostereometric analysis (RSA) known for its ability to predict aseptic loosening. A total of 72 patients were randomized to either cementless 3D-printed or a cemented cruciate retaining TKA. RSA and clinical scores were evaluated at baseline and postoperatively at three, 12, and 24 months. A mixed model was used to analyze the repeated measurements.Aims
Methods
We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice. Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time.Aims
Methods
Arthroplasty for end-stage hallux rigidus (HR) is controversial. Arthrodesis remains the gold standard for surgical treatment, although is not without its complications, with rates of up to 10% for nonunion, 14% for reoperation and 10% for metatarsalgia. The aim of this study was to analyze the outcome of a double-stemmed silastic implant (Wright-Medical, Memphis, Tennessee, USA) for patients with end-stage HR. We conducted a retrospective review of 108 consecutive implants in 76 patients, between January 2005 and December 2016, with a minimum follow-up of two years. The mean age of the patients at the time of surgery was 61.6 years (42 to 84). There were 104 females and four males. Clinical, radiological, patient reported outcome measures (PROMS) data, a visual analogue score (VAS) for pain, and satisfaction scores were collected.Aims
Methods
Despite its intrinsic ability to regenerate form and function after injury, bone tissue can be challenged by a multitude of pathological conditions. While innovative approaches have helped to unravel the cascades of bone healing, this knowledge has so far not improved the clinical outcomes of bone defect treatment. Recent findings have allowed us to gain in-depth knowledge about the physiological conditions and biological principles of bone regeneration. Now it is time to transfer the lessons learned from bone healing to the challenging scenarios in defects and employ innovative technologies to enable biomaterial-based strategies for bone defect healing. This review aims to provide an overview on endogenous cascades of bone material formation and how these are transferred to new perspectives in biomaterial-driven approaches in bone regeneration. Cite this article: T. Winkler, F. A. Sass, G. N. Duda, K. Schmidt-Bleek. A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering: The unsolved challenge.
This study presents the long-term survivorship, risk factors for prosthesis survival, and an assessment of the long-term effects of changes in surgical technique in a large series of patients treated by metal-on-metal (MoM) hip resurfacing arthroplasty (HRA). Between November 1996 and January 2012, 1074 patients (1321 hips) underwent HRA using the Conserve Plus Hip Resurfacing System. There were 787 men (73%) and 287 women (27%) with a mean age of 51 years (14 to 83). The underlying pathology was osteoarthritis (OA) in 1003 (75.9%), developmental dysplasia of the hip (DDH) in 136 (10.3%), avascular necrosis in 98 (7.4%), and other conditions, including inflammatory arthritis, in 84 (6.4%).Aims
Patients and Methods
The use of trabecular metal (TM) shells supported by augments has provided good mid-term results after revision total hip arthroplasty (THA) in patients with a bony defect of the acetabulum. The aim of this study was to assess the long-term implant survivorship and radiological and clinical outcomes after acetabular revision using this technique. Between 2006 and 2010, 60 patients (62 hips) underwent acetabular revision using a combination of a TM shell and augment. A total of 51 patients (53 hips) had complete follow-up at a minimum of seven years and were included in the study. Of these patients, 15 were men (29.4%) and 36 were women (70.6%). Their mean age at the time of revision THA was 64.6 years (28 to 85). Three patients (5.2%) had a Paprosky IIA defect, 13 (24.5%) had a type IIB defect, six (11.3%) had a type IIC defect, 22 (41.5%) had a type IIIA defect, and nine (17%) had a type IIIB defect. Five patients (9.4%) also had pelvic discontinuity.Aims
Patients and Methods
In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year.Objectives
Patients and Methods
The aim of this study was to determine the stability of a new
short femoral stem compared with a conventional femoral stem in
patients undergoing cementless total hip arthroplasty (THA), in
a prospective randomized controlled trial using radiostereometric
analysis (RSA). A total of 53 patients were randomized to receive cementless
THA with either a short femoral stem (MiniHip, 26 patients, mean
age: 52 years, nine male) or a conventional length femoral stem
(MetaFix, 23 patients, mean age: 53 years, 11 male). All patients
received the same cementless acetabular component. Two-year follow-up
was available on 38 patients. Stability was assessed through migration
and dynamically inducible micromotion. Radiographs for RSA were
taken postoperatively and at three, six, 12, 18, and 24 months.Aims
Patients and Methods
Increasing innovation in rapid prototyping (RP)
and additive manufacturing (AM), also known as 3D printing, is bringing
about major changes in translational surgical research. This review describes the current position in the use of additive
manufacturing in orthopaedic surgery. Cite this article:
Controversy about the use of an anatomical total shoulder arthroplasty
(aTSA) in young arthritic patients relates to which is the ideal
form of fixation for the glenoid component: cemented or cementless.
This study aimed to evaluate implant survival of aTSA when used
in patients aged < 60 years with primary glenohumeral osteoarthritis (OA),
and to compare the survival of cemented all-polyethylene and cementless
metal-backed glenoid components. A total of 69 consecutive aTSAs were performed in 67 patients
aged < 60 years with primary glenohumeral OA. Their mean age
at the time of surgery was 54 years (35 to 60). Of these aTSAs,
46 were undertaken using a cemented polyethylene component and 23
were undertaken using a cementless metal-backed component. The age, gender,
preoperative function, mobility, premorbid glenoid erosion, and
length of follow-up were comparable in the two groups. The patients
were reviewed clinically and radiographically at a mean of 10.3
years (5 to 12, Aims
Materials and Methods
The survivorship of contemporary resurfacing arthroplasty of the hip using metal-on-metal bearings is better than that of first generation designs, but short-term failures still occur. The most common reasons for failure are fracture of the femoral neck, loosening of the component, osteonecrosis of the femoral head, reaction to metal debris and malpositioning of the component. In 2008 the Australian National Joint Registry reported an inverse relationship between the size of the head component and the risk of revision in resurfacing hip arthroplasty. Hips with a femoral component size of ≤ 44 mm have a fivefold increased risk of revision than those with femoral components of ≥ 55 mm irrespective of gender. We have reviewed the literature to explore this observation and to identify possible reasons including the design of the implant, loading of the femoral neck, the orientation of the component, the production of wear debris and the effects of metal ions, penetration of cement and vascularity of the femoral head. Our conclusion is that although multifactorial, the most important contributors to failure in resurfacing arthroplasty of the hip are likely to be the design and geometry of the component and the orientation of the acetabular component.
We report on 397 consecutive revision total hip
replacements in 371 patients with a mean clinical and radiological follow-up
of 12.9 years (10 to 17.7). The mean age at surgery was 69 years
(37 to 93). A total of 28 patients (8%) underwent further revision,
including 16 (4%) femoral components. In all 223 patients (56%,
233 hips) died without further revision and 20 patients (5%, 20
hips) were lost to follow-up. Of the remaining patients, 209 (221
hips) were available for clinical assessment and 194 (205 hips)
for radiological review at mean follow-up of 12.9 years (10 to 17.7). The mean Harris Hip Score improved from 58.7 (11 to 92) points
to 80.7 (21 to 100) (p <
0.001) and the mean Merle d’Aubigné and
Postel hip scores at final follow-up were 4.9 (2 to 6), 4.5 (2 to
6) and 4.3 (2 to 6), respectively for pain, mobility and function.
Radiographs showed no lucencies around 186 (90.7%) femoral stems
with stable bony ingrowth seen in 199 stems (97%). The survival
of the S-ROM femoral stem at 15 years with revision for any reason as
the endpoint was 90.5% (95% confidence interval (CI) 85.7 to 93.8)
and with revision for aseptic loosening as the endpoint 99.3% (95%
CI 97.2 to 99.8). We have shown excellent long-term survivorship and good clinical
outcome of a cementless hydroxyapatite proximally-coated modular
femoral stem in revision hip surgery. Cite this article:
We report on the outcome of the Synergy cementless femoral stem
with a minimum follow-up of 15 years (15 to 17). A retrospective review was undertaken of a consecutive series
of 112 routine primary cementless total hip arthroplasties (THAs)
in 102 patients (112 hips). There were 60 female and 42 male patients
with a mean age of 61 years (18 to 82) at the time of surgery. A
total of 78 hips in the 69 patients remain Aims
Patients and Methods
We retrospectively reviewed 44 consecutive patients
(50 hips) who underwent acetabular re-revision after a failed previous
revision that had been performed using structural or morcellised
allograft bone, with a cage or ring for uncontained defects. Of
the 50 previous revisions, 41 cages and nine rings were used with
allografts for 14 minor-column and 36 major-column defects. We routinely
assessed the size of the acetabular bone defect at the time of revision
and re-revision surgery. This allowed us to assess whether host
bone stock was restored. We also assessed the outcome of re-revision
surgery in these circumstances by means of radiological characteristics,
rates of failure and modes of failure. We subsequently investigated
the factors that may affect the potential for the restoration of bone
stock and the durability of the re-revision reconstruction using
multivariate analysis. At the time of re-revision, there were ten host acetabula with
no significant defects, 14 with contained defects, nine with minor-column,
seven with major-column defects and ten with pelvic discontinuity.
When bone defects at re-revision were compared with those at the
previous revision, there was restoration of bone stock in 31 hips, deterioration
of bone stock in nine and remained unchanged in ten. This was a
significant improvement (p <
0.001). Morselised allografting
at the index revision was not associated with the restoration of
bone stock. In 17 hips (34%), re-revision was possible using a simple acetabular
component without allograft, augments, rings or cages. There were
47 patients with a mean follow-up of 70 months (6 to 146) available
for survival analysis. Within this group, the successful cases had
a minimum follow-up of two years after re-revision. There were 22 clinical
or radiological failures (46.7%), 18 of which were due to aseptic
loosening. The five and ten year Kaplan–Meier survival rate was
75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with
aseptic loosening as the endpoint. The rate of aseptic loosening
was higher for hips with pelvic discontinuity (p = 0.049) and less
when the allograft had been in place for longer periods (p = 0.040). The use of a cage or ring over structural allograft bone for
massive uncontained defects in acetabular revision can restore host
bone stock and facilitate subsequent re-revision surgery to a certain
extent. Cite this article:
An understanding of the remodelling of tendon is crucial for the development of scientific methods of treatment and rehabilitation. This study tested the hypothesis that tendon adapts structurally in response to changes in functional loading. A novel model allowed manipulation of the mechanical environment of the patellar tendon in the presence of normal joint movement via the application of an adjustable external fixator mechanism between the patella and the tibia in sheep, while avoiding exposure of the patellar tendon itself. Stress shielding caused a significant reduction in the structural and material properties of stiffness (79%), ultimate load (69%), energy absorbed (61%), elastic modulus (76%) and ultimate stress (72%) of the tendon compared with controls. Compared with the material properties the structural properties exhibited better recovery after re-stressing with stiffness 97%, ultimate load 92%, energy absorbed 96%, elastic modulus 79% and ultimate stress 80%. The cross-sectional area of the re-stressed tendons was significantly greater than that of stress-shielded tendons. The remodelling phenomena exhibited in this study are consistent with a putative feedback mechanism under strain control. This study provides a basis from which to explore the interactions of tendon remodelling and mechanical environment.
Bone preservation and physiological distribution of forces on the proximal femur are key elements in introducing a successful uncemented total hip replacement. In order to achieve this, in the mid 1990s, we developed an ultra short proximal loading custom-made component with a lateral flare, a high femoral neck osteotomy and without a diaphyseal stem. We report the outcome of 129 custom-made hydroxyapatite-coated uncemented short femoral components inserted into 109 patients between June 1995 and May 2004. The mean age of the patients was 51 years (21 to 71) and the mean follow-up was eight years (4.9 to 14.1). Bone behaviour around the implant was studied on the post-operative radiographs. The mean Harris hip score improved from 44 (8 to 66) pre-operatively to 95 (76 to 100) at final follow-up. The Western Ontario MacMaster University Osteoarthritis index was 93 of 100 at final review. None of the patients reported thigh pain. A total of five hips were revised, three for polyethylene liner exchange and two for complete revision of the acetabular component. No femoral components were revised. The radiological changes in the proximal femur were generally good, as evidenced by spot welds both on the medial and lateral aspects of the femur. No component migrated. The presence of a lateral flare and use of a high osteotomy of the femoral neck provided good clinical and radiological results. The absence of a diaphyseal portion of the stem did not impair stability.
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which fixation in each zone can
be obtained are discussed. The authors suggest that solid fixation
should be obtained in at least two of the three zones and emphasise
the importance of pre-operative planning and implant selection. Cite this article:
Revision total hip arthroplasty (THA) is challenging
when there is severe loss of bone in the proximal femur. The purpose
of this study was to evaluate the clinical and radiographic outcomes
of revision THA in patients with severe proximal femoral bone loss
treated with a fluted, tapered, modular femoral component. Between
January 1998 and December 2004, 92 revision THAs were performed
in 92 patients using a single fluted, tapered, modular femoral stem
design. Pre-operative diagnoses included aseptic loosening, infection
and peri-prosthetic fracture. Bone loss was categorised pre-operatively
as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic
fracture. The mean clinical follow-up was 6.4 years (2 to 12). A
total of 47 patients had peri-operative complications, 27 of whom
required further surgery. However, most of these further operations
involved retention of a well-fixed femoral stem, and 88/92 femoral
components (97%) remained Revision THA in patients with extensive proximal femoral bone
loss using the Link MP fluted, tapered, modular stem led to a high
rate of osseointegration of the stem at mid-term follow-up. Cite this article:
We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p <
0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.
Cementless femoral stems are currently preferred
for total hip replacement (THR) in the United States. Improvements
in stem design, instrumentation and surgical technique have made
this technology highly successful, reproducible, and applicable
to the vast majority of patients requiring a THR. However, there
are ongoing developments in some aspects of stem design that influence
clinical results, the incidence of complications and their inherent adaptability
in accommodating the needs of individual patients. Here we examine
some of these design features. Cite this article:
The outcome at ten years of 100 Freeman hip stems (Finsbury Orthopaedics, Leatherhead, United Kingdom) retaining the neck with a proximal hydroxyapatite coating in a series of 52 men (six bilateral) and 40 women (two bilateral), has been described previously. None required revision for aseptic loosening. We have extended the follow-up to 20 years with a minimum of 17 years. The mean age of the patients at total hip replacement was 58.9 years (19 to 84). Six patients were lost to follow-up, but were included up to their last clinical review. A total of 22 patients (22 hips) had died, all from causes unrelated to their surgery. There have been 43 re-operations for failure of the acetabular component. However, in 38 of these the stem was not revised since it remained stable and there was no associated osteolysis. Two of the revisions were for damage to the trunnion after fracture of a modular ceramic head, and in another two, removal of the femoral component was because of the preference of the surgeon. In all cases the femoral component was well fixed, but could be extracted at the time of acetabular revision. In one case both components were revised for deep infection. There has been one case of aseptic loosening of the stem which occurred at 14 years. This stem had migrated distally by 7.6 mm in ten years and 8.4 mm at the time of revision at which stage it was found to be rotationally loose. With hindsight this component had been undersized at implantation. The survivorship for the stem at 17 years with aseptic loosening as the endpoint was 98.6% (95% confidence interval 95.9 to 100) when 62 hips were at risk. All remaining stems had a satisfactory clinical and radiological outcome. The Freeman proximally hydroxyapatite-coated femoral component is therefore a dependable implant and its continued use can be recommended.
Our aim was to compare polylevolactic acid screws
with titanium screws when used for fixation of the distal tibiofibular
syndesmosis at mid-term follow-up. A total of 168 patients, with
a mean age of 38.5 years (18 to 72) who were randomly allocated
to receive either polylevolactic acid (n = 86) or metallic (n =
82) screws were included. The Baird scoring system was used to assess
the overall satisfaction and functional recovery post-operatively.
The demographic details and characteristics of the injury were similar
in the two groups. The mean follow-up was 55.8 months (48 to 66).
The Baird scores were similar in the two groups at the final follow-up.
Patients in the polylevolactic acid group had a greater mean dorsiflexion
(p = 0.011) and plantar-flexion of the injured ankles (p <
0.001).
In the same group, 18 patients had a mild and eight patients had
a moderate foreign body reaction. In the metallic groups eight had
mild and none had a moderate foreign body reaction (p <
0.001).
In total, three patients in the polylevolactic acid group and none
in the metallic group had heterotopic ossification (p = 0.246). We conclude that both screws provide adequate fixation and functional
recovery, but polylevolactic acid screws are associated with a higher
incidence of foreign body reactions. Cite this article:
This study reviewed the results of a cementless anatomical femoral component to give immediate post-operative stability, and with a narrow distal section in order not to contact the femoral cortex in the diaphysis, ensuring exclusively metaphyseal loading. A total of 471 patients (601 hips) who had a total hip replacement between March 1995 and February 2002 were included in the study. There were 297 men and 174 women. The mean age at the time of operation was 52.7 years (28 to 63). Clinical and radiological evaluation were performed at each follow-up. Bone densitometry was carried out on all patients two weeks after operation and at the final follow-up examination. The mean follow-up was 8.8 years (5 to 12). The mean pre-operative Harris hip score was 41 points (16 to 54), which improved to a mean of 96 (68 to 100) at the final follow-up. No patient complained of thigh pain at any stage. No acetabular or femoral osteolysis was observed and no hip required revision for aseptic loosening of either component. Deep infection occurred in two hips (0.3%) which required revision. One hip (0.2%) required revision of the acetabular component for recurrent dislocation. Bone mineral densitometry revealed a minimal bone loss in the proximal femur. This cementless anatomical femoral component with metaphyseal loading but without distal fixation produced satisfactory fixation and encourages proximal femoral loading.
The February 2013 Oncology Roundup360 looks at: proximal fibular tumours; radiotherapy-induced chondrosarcoma; mega-prosthesis; CRP predictions of sarcoma survival; predicting survival in metastatic disease; MRI for recurrence in osteoid osteoma; and a sarcoma refresher
The Gamma nail is frequently used in unstable
peri-trochanteric hip fractures. We hypothesised that mechanical failure
of the Gamma nail was associated with inadequate proximal three-point
fixation. We identified a consecutive series of 299 Gamma nails
implanted in 299 patients over a five-year period, 223 of whom fulfilled
our inclusion criteria for investigation. The series included 61
men and 162 women with a mean age of 81 years (20 to 101). Their fractures
were classified according to the Modified Evans’ classification
and the quality of fracture reduction was graded. The technical
adequacy of three points of proximal fixation was recorded from
intra-operative fluoroscopic images, and technical inadequacy for
each point was defined. All patients were followed to final follow-up
and mechanical failures were identified. A multivariate statistical
analysis was performed, adjusting for confounders. A total of 16
failures (7.2%) were identified. The position of the lag screw relative
to the lateral cortex was the most important point of proximal fixation,
and when inadequate the failure rate was 25.8% (eight of 31: odds
ratio 7.5 (95% confidence interval 2.5 to 22.7), p <
0.001). Mechanical failure of the Gamma nail in peri-trochanteric femoral
fractures is rare (<
1%) when three-point proximal fixation is
achieved. However, when proximal fixation is inadequate, failure
rates increase. The strongest predictor of failure is positioning
the lateral end of the lag screw short of the lateral cortex. Adherence
to simple technical points minimises the risk of fixation failure
in this vulnerable patient group. Cite this article:
To quantify and compare peri-acetabular bone mineral density
(BMD) between a monoblock acetabular component using a metal-on-metal
(MoM) bearing and a modular titanium shell with a polyethylene (PE)
insert. The secondary outcome was to measure patient-reported clinical
function. A total of 50 patients (25 per group) were randomised to MoM
or metal-on-polyethlene (MoP). There were 27 women (11 MoM) and
23 men (14 MoM) with a mean age of 61.6 years (47.7 to 73.2). Measurements
of peri-prosthetic acetabular and contralateral hip (covariate)
BMD were performed at baseline and at one and two years’ follow-up.
The Western Ontario and McMaster Universities osteoarthritis index
(WOMAC), University of California, Los Angeles (UCLA) activity score,
Harris hip score, and RAND-36 were also completed at these intervals.Objectives
Methods
Trabecular metal (TM) augments are a relatively
new option for reconstructing segmental bone loss during acetabular
revision. We studied 34 failed hip replacements in 34 patients that
were revised between October 2003 and March 2010 using a TM acetabular
shell and one or two augments. The mean age of the patients at the
time of surgery was 69.3 years (46 to 86) and the mean follow-up
was 64.5 months (27 to 107). In all, 18 patients had a minor column
defect, 14 had a major column defect, and two were associated with
pelvic discontinuity. The hip centre of rotation was restored in
27 patients (79.4%). The Oxford hip score increased from a mean
of 15.4 points (6 to 25) before revision to a mean of 37.7 (29 to
47) at the final follow-up. There were three aseptic loosenings
of the construct, two of them in the patients with pelvic discontinuity.
One septic loosening also occurred in a patient who had previously
had an infected hip replacement. The augments remained stable in
two of the failed hips. Whenever there was a loose acetabular component
in contact with a stable augment, progressive metal debris shedding
was evident on the serial radiographs. Complications included another
deep infection treated without revision surgery. Good clinical and
radiological results can be expected for bone-deficient acetabula
treated by a TM cup and augment, but for pelvic discontinuities
this might not be a reliable option. Cite this article:
Stems improve the mechanical stability of tibial
components in total knee replacement (TKR), but come at a cost of stress
shielding along their length. Their advantages include resistance
to shear, reduced tibial lift-off and increased stability by reducing
micromotion. Longer stems may have disadvantages including stress
shielding along the length of the stem with associated reduction
in bone density and a theoretical risk of subsidence and loosening, peri-prosthetic
fracture and end-of-stem pain. These features make long stems unattractive
in the primary TKR setting, but often desirable in revision surgery
with bone loss and instability. In the revision scenario, stems
are beneficial in order to convey structural stability to the construct
and protect the reconstruction of bony defects. Cemented and uncemented
long stemmed implants have different roles depending on the nature
of the bone loss involved. This review discusses the biomechanics of the design of tibial
components and stems to inform the selection of the component and
the technique of implantation.
Most surgeons favour removing forearm plates
in children. There is, however, no long-term data regarding the complications
of retaining a plate. We present a prospective case series of 82
paediatric patients who underwent plating of their forearm fracture
over an eight-year period with a minimum follow-up of two years.
The study institution does not routinely remove forearm plates.
A total of 116 plates were used: 79 one-third tubular plates and 37 dynamic
compression plates (DCP). There were 12 complications: six plates
(7.3%) were removed for pain or stiffness and there were six (7.3%)
implant-related fractures. Overall, survival of the plates was 85%
at 10 years. Cox regression analysis identified radial plates (odds
ratio (OR) 4.4, p = 0.03) and DCP fixation (OR 3.2, p = 0.02) to
be independent risk factors of an implant-related fracture. In contrast
ulnar plates were more likely to cause pain or irritation necessitating
removal (OR 5.6, p = 0.04). The complications associated with retaining a plate are different,
but do not occur more frequently than the complications following
removal of a plate in children.
