Total hip arthroplasty (THA) is performed under general anesthesia (GA) or spinal anesthesia (SA). The first objective of this study was to determine which patient factors are associated with receiving SA versus GA. The second objective was to discern the effect of anesthesia type on short-term postoperative complications and readmission. The third objective was to elucidate factors that impact the effect of anesthesia type on outcome following arthroplasty. This retrospective cohort study included 108,905 patients (median age, 66 years; IQR 60-73 years; 56.0% females) who underwent primary THA for treatment of primary osteoarthritis in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database during the period of 2013-2018. Multivariable logistic regression analysis was performed to evaluate variables associated with anesthesia type and outcomes following arthroplasty. Anesthesia type administered during THA was significantly associated with race. Specifically, Black and Hispanic patients were less likely to receive SA compared to White patients (White: OR 1.00; Black: OR 0.73; 95% confidence interval [CI] 0.71-0.75; Hispanic: OR 0.81; CI, 0.75-0.88), while Asian patients were more likely to receive SA (OR 1.44, CI 1.31-1.59). Spinal anesthesia was associated with increased age (OR 1.01; CI 1.00-1.01). Patients with less frailty and lower comorbidity were more likely to receive SA based on the modified frailty index ([mFI-5]=0: OR 1.00; mFI-5=1: OR 0.90, CI 0.88-0.93; mFI-5=2 or greater: OR 0.86, CI 0.83-0.90) and American Society of Anesthesiologists (ASA) class (ASA=1: OR 1.00; ASA=2: OR 0.85, CI 0.79-0.91; ASA=3: OR 0.64, CI 0.59-0.69; ASA=4-5: OR 0.47; CI 0.41-0.53). With increased BMI, patients were less likely to be treated with SA (OR 0.99; CI 0.98-0.99). Patients treated with SA had less post-operative complications than GA (OR 0.74; CI 0.67-0.81) and a lower risk of readmission than GA (OR 0.88; CI 0.82-0.95) following THA. Race, age, BMI, and ASA class were found to affect the impact of anesthesia type on post-operative complications. Stratified analysis demonstrated that the reduced risk of complications following arthroplasty noted in patients treated with SA compared to GA was more pronounced in Black, Asian, and Hispanic patients compared to White patients. Furthermore, the positive effect of SA compared to GA was stronger in patients who had reduced age, elevated BMI, and lower ASA class. Among patients undergoing THA for management of primary osteoarthritis, factors including race, BMI, and frailty appear to have impacted the type of anesthesia received. Patients treated with SA had a significantly lower risk of readmission to hospital and adverse events within 30 days of surgery compared to those treated with GA. Furthermore, the positive effect on outcome afforded by SA was different between patients depending on race, age, BMI, and ASA class. These findings may help to guide selection of anesthesia type in subpopulations of patients undergoing primary THA.
The management of periprosthetic distal femur fractures is an issue of increasing importance for orthopaedic surgeons. Because of the expanding indications for total knee arthroplasty (TKA) and an aging population with increasingly active lifestyles there has been a corresponding increase in the prevalence of these injuries. The management of these fractures is often complex because of issues with obtaining fixation around implants and dealing with osteopenic bone or compromised bone stock. In addition, these injuries frequently occur in frail, elderly patients, and the early restoration of function and ambulation is critical in these patients. There remains substantial controversy with respect to the optimal treatment of periprosthetic distal femur fractures, with some advocating for Locked Plating (LP), others Retrograde Intramedullary Nailing (RIMN) and finally those who advocate for Distal Femoral Replacement (DFR). The literature comparing these treatments, has been infrequent, and commonly restricted to single-center studies. The purpose of this study was to retrospectively evaluate a large series of operatively treated periprosthetic distal femur fractures from multiple centers and compare treatment strategies. Patients who were treated operatively for a periprosthetic distal femur fracture at 8 centers across North America between 2003 and 2018 were retrospectively identified. Baseline characteristics, surgical details and post-operative clinical outcomes were collected from patients meeting inclusion criteria. Inclusion criteria were patients aged 18 and older, any displaced operatively treated periprosthetic femur fracture and documented 1 year follow-up. Patients with other major lower extremity trauma or ipsilateral total hip replacement were excluded. Patients were divided into 3 groups depending on the type of fixation received: Locked Plating, Retrograde Intramedullary Nailing and Distal Femoral Replacement. Documented clinical follow-up was reviewed at 2 weeks, 3 months, 6 months and 1 year following surgery. Outcome and covariate measures were assessed using basic descriptive statistics. Categorical variables, including the rate of re-operation, were compared across the three treatment groups using Fisher Exact Test. In total, 121 patients (male: 21% / female: 79%) from 8 centers were included in our analysis. Sixty-seven patients were treated with Locked Plating, 15 with Retrograde Intramedullary Nailing, and 39 were treated with Distal Femoral Replacement. At 1 year, 64% of LP patients showed radiographic union compared to 77% in the RIMN group (p=0.747). Between the 3 groups, we did not find any significant differences in ambulation, return to work and complication rates at 6 months and 1 year (Table 1). Reoperation rates at 1 year were 27% in the LP group (17 reoperations), 16% in the DFR group (6 reoperations) and 0% in the RIMN group. These differences were not statistically significant (p=0.058). We evaluated a large multicenter series of operatively treated periprosthetic distal femur fractures in this study. We did not find any statistically significant differences at 1 year between treatment groups in this study. There was a trend towards a lower rate of reoperation in the Retrograde Intramedullary Nailing group that should be evaluated further with prospective studies. For any figures or tables, please contact the authors directly.
Patients with longstanding hip fusion are predisposed to symptomatic degenerative changes of the lumbar spine, ipsilateral knee and contralateral hip The aim of this study was to determine the functional results and complications in patients undergoing hip fusion conversion to total hip replacement, performed or supervised by a single surgeon. Twenty-eight hip fusions were converted between 1996 and 2016. Mean follow up was 7 years (3 to 18 years). The reasons for arthrodesis were trauma 11, septic arthritis 10, and dysplasia 7. The mean age at conversion was 52.4 years (26 to 77). A trochanteric osteotomy was performed in all hips. Uncemented components were used. A constrained liner was used in 7 hips. Heterotopic ossification prophylaxis was not used in this series. HHS improved a mean of 27 points (37.4 pre-op to 64.3 post-op). A cane was used in 30% of patients before conversion and 80% after. Heterotopic ossification occurred in 12 (42.9%) hips. There was 2 peroneal nerve injuries, 1 dislocation, 1 GT non-union and 1 infection. There have been 5 revisions; 2 for aseptic loosening, 1 for infection, 1 for recurrent dislocation and 1 for leg length discrepancy. Conversion of hip fusion to hip replacement carries an increased risk of heterotopic ossification and neurological injury. We advise prophylaxis against heterotropic ossification. When there is concern about hip stability we suggest that the use of a constrained acetabular liner is considered. Despite the potential for complications, this procedure had a high success rate and was effective in restoring hip function.
The effect of using thicker liners in primary total knee arthroplasty (TKA) on functional outcomes and aseptic failure rates remains largely unknown. As such, we devised a multicenter study to assess both the clinical outcomes and survivorship of thick vs thin liners after primary TKA. A search of our institutional databases was performed for patients having undergone bilateral (simultaneous or staged) primary TKA with similar preoperative and surgical characteristics between both sides. Two cohorts were created: thick liners and thin liners. Outcomes collected were as follows: change in Knee Society Score (DKSS), change in range of motion, and aseptic revision. Ad hoc power analysis was performed for DKSS (α ¼ 0.05; power ¼ 80%). Differences between cohorts were assessed.Introduction
Methods
Patellar dislocation is a serious complication leading to patient morbidity following total knee arthroplasty. The cause can be multifactorial. Extensor mechanism imbalance may be present and result from technical errors such as malrotation of the implants. We performed a retrospective study assessing the outcomes of revision surgery for patellar dislocation in patients with component malrotation in both primary and revision total knee arthroplasty. Patient demographics, etiology of dislocation, presurgical deformity, intraoperation component position, complications, reoperation and knee society scores were collected.Background
Methods
The aim of this study was to assess the effects of transferring patients to a specialized arthroplasty centre between the first and second stages (interstage) of prosthetic joint infection (PJI) of the knee. A search of our institutional database was performed to identify patients having undergone two-stage revision total knee arthroplasty (TKA) for PJI. Two cohorts were created: continuous care (CC) and transferred care (TC). Baseline characteristics and outcomes were collected and compared between cohorts.Aims
Patients and Methods
Recent analyses of failure mechanisms continue to show aseptic loosening as the predominant mechanism of total knee arthroplasty (TKA) failure. Evaluation for aseptic loosening begins with careful assessment of plain films radiographs, however the utility of examining lucent lines under a cemented tibial tray remains unclear. The purpose of this study is to examine the distribution of lucent lines under cemented tibial components on single-series anteroposterior (AP) and lateral plain radiographs and to determine their significance in the prediction of aseptic loosening found during revision TKA surgery. Retrospective chart and radiographic review of all patients that underwent revision TKA between 2001–2014 at a single academic hospital center. Revision TKA for periprosthetic fracture, stem fracture, implant dissociation and periprosthetic joint infection were excluded. The most recent pre-revision surgery AP and lateral knee radiographs were assessed by two fellowship trained adult reconstruction surgeons blinded to patient demographics and intraoperative details. Lucent lines under the tibia tray defined as >2mm were documented according to the new KSS radiographic scoring system. Demographic details and the surgeon's assessment whether the tibia tray was loose intraoperatively were extracted from chart review and the operative note, respectively. Univariate and multivariable logistic regression modeling was used to predict the outcome of aseptic loosening. Between 2001 and 2014, 312 revision TKAs were performed that met our inclusion criteria. Of these, 84 (26.9%) had intraoperative loose tibia trays. We observed a significantly increased risk of aseptic tibia loosening among older patients at time of surgery (odds ratio [OR] 1.05, 95% CI 1.02, 1.08). Posterior stabilised primary TKA components conferred a significantly decreased risk of aseptic tibia loosening (OR 0.36, 95% 0.21, 0.60). On an AP radiograph, after adjustment for other zones, the presence of a lucent line in zone 1, 2 or 3 were all significantly associated with tibia loosening, OR 7.35, 8.69 and 22.26 (p<0.0001) respectively. On a lateral radiograph, after adjustment for other zones, the presence of a lucent line in zone 1, 2 or 3 were all significantly associated with tibia loosening, OR 12.89, 18.03, and 11.63 (p<0.004) respectively. The complete absence of lucent lines under a tibia tray on an AP or lateral radiograph were associated with 96% (CI 0.02, 0.07) and 95% (CI 0.02, 0.09) reduced odds of aseptic tibia loosening. Careful examination of lucent lines under a tibia component can be highly predictive of aseptic loosening. The areas associated with highest risk of tibia loosening occur in zone 3 on the AP radiograph (medial or lateral to the keel) and zone 2 on the lateral radiograph (posteriorly). The risk of loosening in the absence of lucent line findings on plain films is significantly low.
This study reports the clinical outcome of reconstruction
of deficient abductor muscles following revision total hip arthroplasty
(THA), using a fresh–frozen allograft of the extensor mechanism
of the knee. A retrospective analysis was conducted of 11 consecutive
patients with a severe limp because of abductor deficiency which
was confirmed on MRI scans. The mean age of the patients (three
men and eight women) was 66.7 years (52 to 84), with a mean follow-up
of 33 months (24 to 41). Following surgery, two patients had no limp, seven had a mild
limp, and two had a persistent severe limp (p = 0.004). The mean
power of the abductors improved on the Medical Research Council
scale from 2.15 to 3.8 (p <
0.001). Pre-operatively, all patients
required a stick or walking frame; post-operatively, four patients
were able to walk without an aid. Overall, nine patients had severe
or moderate pain pre-operatively; ten patients had no or mild pain
post-operatively. At final review, the Harris hip score was good in five patients,
fair in two and poor in four. We conclude that using an extensor mechanism allograft is relatively
effective in the treatment of chronic abductor deficiency of the
hip after THA when techniques such as local tissue transfer are
not possible. Longer-term follow-up is necessary before the technique can be
broadly applied. Cite this article:
The purpose of this study was to identify factors
that predict implant cut-out after cephalomedullary nailing of intertrochanteric
and subtrochanteric hip fractures, and to test the significance
of calcar referenced tip-apex distance (CalTAD) as a predictor for
cut-out. We retrospectively reviewed 170 consecutive fractures that had
undergone cephalomedullary nailing. Of these, 77 met the inclusion
criteria of a non-pathological fracture with a minimum of 80 days
radiological follow-up (mean 408 days; 81 days to 4.9 years). The
overall cut-out rate was 13% (10/77). The significant parameters in the univariate analysis were tip-apex
distance (TAD) (p <
0.001), CalTAD (p = 0.001), cervical angle
difference (p = 0.004), and lag screw placement in the anteroposterior
(AP) view (Parker’s ratio index) (p = 0.003). Non-significant parameters
were age (p = 0.325), gender (p = 1.000), fracture side (p = 0.507),
fracture type (AO classification) (p = 0.381), Singh Osteoporosis
Index (p = 0.575), lag screw placement in the lateral view (p =
0.123), and reduction quality (modified Baumgaertner’s method) (p = 0.575).
In the multivariate analysis, CalTAD was the only significant measurement
(p = 0.001). CalTAD had almost perfect inter-observer reliability
(interclass correlation coefficient (ICC) 0.901). Our data provide the first reported clinical evidence that CalTAD
is a predictor of cut-out. The finding of CalTAD as the only significant
parameter in the multivariate analysis, along with the univariate
significance of Parker’s ratio index in the AP view, suggest that
inferior placement of the lag screw is preferable to reduce the
rate of cut-out. Cite this article:
Restoration of bone loss is a major challenge of revision TKA surgery. It is critical to achieve of a stable construct to support implants and achieve successful results. Major bone defects of the femoral and/or tibia (AORI type IIB/III) have been reconstructed using impaction grafting, structural allografts or tumor prostheses. The major concerns with structural allograft are graft resorption, mechanical failure, tissue availability, disease transmission, considerable surgical skill required and prolonged operative time. Porous tantalum metaphyseal cones, are becoming the established method of choice to correct large bone defects with several recent studies demonstrating promising results. The high coefficient of friction of these implants provides structural support for femoral and tibial components. The high degree of porosity has excellent potential for bone ingrowth and long-term biologic fixation. Several published series, although with relatively small cohorts of patients, have reported good short-term results with trabecular metal cones for major femoral and tibial bony defects in revision TKA. In a recent study, 16 femoral and 17 tibial cones were reviewed at an average follow up of 33 months (range, 13 to 73 months) the mean Knee Society Score improved from 42 pre-operatively to 83 at last follow up with an improvement of the functional score from an average of 34 to 66 (p<0.0001). Radiological follow up revealed no evidence of loosening or migration of the constructs. No evidence of complications were noted in correlation with the use of trabecular metal cones.
Peri-prosthetic distal femoral fractures around total knee replacement is a highly complex reconstructive challenge, particularly in the presence of bone comminution and poor bone quality in elderly patients. With the incidence of peri-prosthetic fractures ranging from 0.3% to 2.5%, this is becoming a common problem. Older patients with concomitant medical issues have a very limited tolerance for prolonged immobilisation. It is the author's practice to revise, rather that attempt to fix, peri-prosthetic fractures of the knee which are very close to the femoral or tibial implants, particularly when associated with osteoporosis and comminution. When compared to fracture fixation, distal femoral replacement has significantly shorter operative time, less blood loss, and shorter hospital stay. Patients have been shown to recover faster, have fewer complications, and left hospital sooner. The general assumption has been that the use of a distal femoral replacement prosthesis is cost prohibitive in revision total knee settings, however, initial differences in the price of the prosthesis are more than offset by a shortened hospital stay and a more rapid return to pre-fracture level of function.
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:
The use of ilioischial cage reconstruction for
pelvic discontinuity has been replaced by the Trabecular Metal (Zimmer,
Warsaw, Indiana) cup-cage technique in our institution, due to the
unsatisfactory outcome of using a cage alone in this situation.
We report the outcome of 26 pelvic discontinuities in 24 patients
(20 women and four men, mean age 65 years (44 to 84)) treated by
the cup-cage technique at a mean follow-up of 82 months (12 to 113)
and compared them with a series of 19 pelvic discontinuities in
19 patients (18 women and one man, mean age 70 years (42 to 86))
treated with a cage at a mean follow-up of 69 months (1 to 170).
The clinical and radiological outcomes as well as the survivorship
of the groups were compared. In all, four of the cup-cage group
(15%) and 13 (68%) of the cage group failed due to septic or aseptic
loosening. The seven-year survivorship was 87.2% (95% confidence interval
(CI) 71 to 103) for the cup-cage group and 49.9% (95% CI 15 to 84)
for the cage-alone group (p = 0.009). There were four major complications
in the cup-cage group and nine in the cage group. Radiological union
of the discontinuity was found in all successful cases in the cup-cage
group and three of the successful cage cases. Three hips in the
cup-cage group developed early radiological migration of the components,
which stabilised with a successful outcome. Cup-cage reconstruction is a reliable technique for treating
pelvic discontinuity in mid-term follow-up and is preferred to ilioischial
cage reconstruction. If the continuity of the bone graft at the
discontinuity site is not disrupted, early migration of the components
does not necessarily result in failure. Cite this article:
Total knee replacement (TKR) is one of the most
common operations in orthopaedic surgery worldwide. Despite its
scientific reputation as mainly successful, only 81% to 89% of patients
are satisfied with the final result. Our understanding of this discordance
between patient and surgeon satisfaction is limited. In our experience,
focus on five major factors can improve patient satisfaction rates:
correct patient selection, setting of appropriate expectations,
avoiding preventable complications, knowledge of the finer points
of the operation, and the use of both pre- and post-operative pathways.
Awareness of the existence, as well as the identification of predictors
of patient–surgeon discordance should potentially help with enhancing
patient outcomes. Cite this article:
Down’s syndrome is associated with a number of
musculoskeletal abnormalities, some of which predispose patients
to early symptomatic arthritis of the hip. The purpose of the present
study was to review the general and hip-specific factors potentially
compromising total hip replacement (THR) in patients with Down’s
syndrome, as well as to summarise both the surgical techniques that
may anticipate the potential adverse impact of these factors and
the clinical results reported to date. A search of the literature
was performed, and the findings further informed by the authors’
clinical experience, as well as that of the hip replacement in Down
Syndrome study group. The general factors identified include a high
incidence of ligamentous laxity, as well as associated muscle hypotonia
and gait abnormalities. Hip-specific factors include: a high incidence
of hip dysplasia, as well as a number of other acetabular, femoral
and combined femoroacetabular anatomical variations. Four studies
encompassing 42 hips, which reported the clinical outcomes of THR
in patients with Down’s syndrome, were identified. All patients
were successfully treated with standard acetabular and femoral components.
The use of supplementary acetabular screw fixation to enhance component
stability was frequently reported. The use of constrained liners
to treat intra-operative instability occurred in eight hips. Survival
rates of between 81% and 100% at a mean follow-up of 105 months
(6 to 292) are encouraging. Overall, while THR in patients with
Down’s syndrome does present some unique challenges, the overall
clinical results are good, providing these patients with reliable
pain relief and good function. Cite this article:
In this retrospective study we evaluated the
proficiency of shelf autograft in the restoration of bone stock
as part of primary total hip replacement (THR) for hip dysplasia,
and in the results of revision arthroplasty after failure of the primary
arthroplasty. Of 146 dysplastic hips treated by THR and a shelf
graft, 43 were revised at an average of 156 months, 34 of which
were suitable for this study (seven hips were excluded because of
insufficient bone-stock data and two hips were excluded because
allograft was used in the primary THR). The acetabular bone stock
of the hips was assessed during revision surgery. The mean implant–bone
contact was 58% (50% to 70%) at primary THR and 78% (40% to 100%)
at the time of the revision, which was a significant improvement
(p <
0.001). At primary THR all hips had had a segmental acetabular
defect >
30%, whereas only five (15%) had significant segmental
bone defects requiring structural support at the time of revision.
In 15 hips (44%) no bone graft or metal augments were used during
revision. A total of 30 hips were eligible for the survival study. At a
mean follow-up of 103 months (27 to 228), two aseptic and two septic
failures had occurred. Kaplan-Meier survival analysis of the revision
procedures demonstrated a ten-year survival rate of 93.3% (95% confidence
interval (CI) 78 to 107) with clinical or radiological failure as
the endpoint. The mean Oxford hip score was 38.7 (26 to 46) for
non-revised cases at final follow-up. Our results indicate that the use of shelf autografts during
THR for dysplastic hips restores bone stock, contributing to the
favourable survival of the revision arthroplasty should the primary
procedure fail. Cite this article:
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:
Secondary degenerative changes of the knee are a well recognized complication of Giant Cell Tumor (GCT). Osteoarthritis (OA) may be a consequence of the lesion itself or its treatment. Total Knee Arthroplasty (TKA) is a treatment option for end stage knee arthritis. In the current study we describe the short term follow up of three patients that underwent TKA for treatment of GCT related OA between 2006–2007. The records of 180 consecutive patients treated for giant cell tumor of the knee between 1989 and 2007 in our institution were reviewed. Three patients were identified that had total knee arthroplasty following treatment of giant cell tumor of the knee, confirmed by tissue biopsy. The review included all clinical notes, pathology and operative reports. Outcomes were assessed based on knee scores and functional scores calculated according to the clinical rating system of The Knee Society, with the assignment of a maximum of 100 points for each. Patient ages range from 29–75 years of age. Assessment occurred pre-operatively as well as post-operatively at six weeks, three months, six months and then yearly. The development of osteoarthritis with severe knee pain was the primary indication for performing TKA.Purpose
Method
Two-stage re-implantation after infection of Total Knee Arthroplasty (TKA), remains the gold standard to which other forms of treatment should be compared. The primary purpose of this study was to determine the rates of failure and functional outcome of two stage revision TKA for treatment of infection comparing cemented posterior stabilized compared to constrained condylar implants. The study group included 25 consecutive patients who had two stage revision TKA to treat infection with an average follow up of 3.25 1.5 years (range 2–6). In all patients the diagnosis of infection was made using standard serum parameters as well as aspiration for joint fluid analysis. Eight patients had posterior stabilized TKAs and 17 patients with had constrained condylar TKAs. Clinical evaluation included the Knee Society Knee Scores (KSKS) at each follow-up visit as well as a detailed record of any difficulties or complications.Purpose
Method
Infection following total knee arthroplasty is a devastating complication, requiring considerable effort on the part of the surgeon to eradicate the infection and restore joint function. Two-stage revision is the standard of care in the treatment of peri-prosthetic infection, using a temporary antibiotic-impregnated spacer between procedures. However, controversy remains concerning the use of static versus dynamic spacers, as well as the spacer material. The purpose of this study was to evaluate the clinical outcomes and complications of two-stage revision total knee arthroplasty in patients treated with a metal-on-polyethylene articulating spacer, as compared to those treated with a static antibiotic-impregnated cement spacer at the same centre. Twenty-seven knees in patients with a mean age of 65 years (range, 40 to 80 years) were treated with two-stage revision of an infected total knee arthroplasty using a metal-on-polyethylene dynamic prosthetic spacer fixed with antibiotic-impregnated cement. Clinical outcomes were evaluated using maximum active knee range of motion, as well as modified Knee Society knee scores and incidence of re-infection at a minimum one-year follow-up. The results were compared to those achieved at similar follow-up in 10 patients treated with a static cement spacer. Demographic profile as measured by age and gender, and pre-operative Knee Society scores and range of motion were similar between the two groups.Purpose
Method
A deficient abductor mechanism leads to significant morbidity and few studies have been published describing methods for reconstruction or repair. This study reports the reconstruction of hip abductor deficiency using human allograft. All patients were identified as having deficient abductor mechanisms following total hip arthroplasty through radiographic assessment, MRI, clinical examination and intra-operative exploration. All patients underwent hip abductor reconstruction using a variety of human allografts including proximal humeral, tensor fascia lata, quadriceps and patellar tendon. The type of allograft reconstruction used was customized to each patient, all being attached to proximal femur, allograft bone adjacent to host bone, with cerclage wires. If a mid-substance muscle rupture was identified an allograft tendon to host tendon reconstruction was performed.Introduction
Methods
Revision hip arthroplasty with massive proximal femoral bone loss remains challenging. Whilst several surgical techniques have been described, few have reported long term supporting data. A proximal femoral allograft (PFA) may be used to reconstitute bone stock in the multiply revised femur with segmental bone loss of greater than 8 cm. This study reports the outcome of largest case series of PFA used in revision hip arthroplasty. Data was prospectively collected from a consecutive series of 69 revision hip cases incorporating PFA and retrospective analyzed. Allografts of greater than 8 cm in length (average 14cm) implanted to replace deficient bone stock during revision hip surgery between 1984 and 2000 were included. The average age at surgery was 56 years (range 32–84) with a minimum follow up of 10 years and a mean of 15.8 years (range).Introduction
Methods
The literature indicates that the tibial component in total knee arthroplasty (TKA) should be placed in internal rotation not exceeding 18 to the line connecting the geometrical center of the proximal tibia and the middle of the tibial tuberosity. These landmarks may not be easily identifiable intraoperatively. Moreover, an angle of 18 is difficult to measure with the naked eye. The angle at the intersection of lines from the middle of the tibial tuberosity and from its medial border to the tibial geometric center was measured in 50 patients with normal tibia. The geometric center was determined on an axial CT slice at 10mm below the lateral tibial plateau and transposed to a slice at the level of the most prominent part of the tibial tuberosity. Similar measurements were performed in 25 patients after TKA in order to simulate the intra operative appearance of the tibia after making its proximal resection.Purpose
Method
The purpose of this study was to determine the functional outcome, imaging and complications of conversion of hip fusion to uncemented total hip replacement. The study group comprised eighteen patients who had undergone conversion of unilateral hip fusion to total hip replacement between 1996 and 2007. There were five men and 13 women. The diagnosis prior to fusion was traumatic injury in eight patients, developmental dysplasia in three patients, and septic arthritis in seven patients. Four of the patient who had septic arthritis in childhood had spontaneous hips fusion while the other underwent surgical arthrodesis. The mean age at the time of conversion was 53 years (range, 21–77) and the mean time between fusion and conversion to hip replacement was 33 years (range, 11–60). Mean follow up was five years (range 2–15 years). Data was collected by retrospective review of a prospective database. Uncemented acetabular components were used in all cases and uncemented femoral components were used in all but two patients. In three patients with abductor and soft tissue deficiency an intraoperative decision was made to use a constrained acetabular liner.Purpose
Method
Surgical training is based on an apprenticeship model. This training can be divided broadly into three main categories: practical skills, knowledge and decision making. The operating room is the nexus of a large part of surgical teaching. The supervising surgeon imparts both practical teaching as well as didactic information to the trainee during surgical procedures. A large amount of decision making skills are also acquired in the OR. Indeed, a large part of the surgical teams time is spent in the operating room which makes it an ideal educational environment. Bench model training is one teaching modality whereby the novice surgeon is taught surgical skills on life-like models. This practice enhances and accelerates the ability of the trainee to acquire fundamental, technical and surgical skills in the operating room. Whether bench model training provides an advantage on the ability of the trainee to acquire knowledge and decision making skills is unknown. Based on the motor learning theories, it is hypothesized that bench-model training will allow junior residents to be more interactive than trainees lacking similar active hands-on training. In this study, we examined whether bench model training provides an advantage on the ability of the trainee to acquire knowledge and decision making skills. 30 junior surgical residents from various surgical divisions, with minimal knowledge of technical, procedural and cognitive skills related to the ulna bone fixation (primary task), were recruited in this study. 15 residents, randomly assigned, were given instructions and the benefit of practice on a bench model, and 15 were given instructions but not the chance to practice the skill on a bench model. All residents, while tested for their accuracy and time taken for ulna fixation (secondary task, decision making skills), were also verbally taught information on different aspects of primary bone healing. This information was evaluated by a multiple-choice test (knowledge acquisition).Purpose
Method
Case logs have been utilized as a means of assessing residents surgical exposure and involvement in cases. It can be argued that the degree of involvement in operative cases is as important as absolute number of cases logged. A log which contains accurate information on actual participation in surgical cases in addition to self reported competency, is a powerful tool in obtaining a true reflection of surgical experience. Thus a prerequisite for a valuable log is the ability to perform an accurate self-assessment. Numerous studies have shown mixed results when examining residents ability to perform self-assessment on varying tasks. The purpose of the study was to examine the correlation between residents self-assessment and staff surgeons evaluation of surgical involvement and competence in performing primary hip and knee arthroplasty surgery. Self assessment data from 65 primary hip and knee arthroplasty cases involving 17 residents and 17 staff surgeons (93% response rate) was analyzed. Interobserver agreement between residents self perception and staff surgeons assessment of involvement was evaluated using the Intraclass Correlation Coefficient (ICC). An assessment of competency was performed utilizing a categorical global scale and evaluated with the Kappa statistic (k). Furthermore, a structured surgical skills assessment form was piloted as an objective appraisal of resident involvement and comparisons were made to resident and staff perception.Purpose
Method
The treatment of substantial proximal femoral
bone loss in young patients with developmental dysplasia of the
hip (DDH) is challenging. We retrospectively analysed the outcome
of 28 patients (30 hips) with DDH who underwent revision total hip
replacement (THR) in the presence of a deficient proximal femur,
which was reconstructed with an allograft prosthetic composite.
The mean follow-up was 15 years (8.5 to 25.5). The mean number of
previous THRs was three (1 to 8). The mean age at primary THR and
at the index reconstruction was 41 years (18 to 61) and 58.1 years
(32 to 72), respectively. The indication for revision included mechanical
loosening in 24 hips, infection in three and peri-prosthetic fracture
in three. Six patients required removal and replacement of the allograft
prosthetic composite, five for mechanical loosening and one for
infection. The survivorship at ten, 15 and 20 years was 93% (95%
confidence interval (CI) 91 to 100), 75.5% (95% CI 60 to 95) and
75.5% (95% CI 60 to 95), respectively, with 25, eight, and four
patients at risk, respectively. Additionally, two junctional nonunions
between the allograft and host femur required bone grafting and
plating. An allograft prosthetic composite affords a good long-term outcome
in the management of proximal femoral bone loss in revision THR
in patients with DDH, while preserving distal host bone.
Primary total hip arthroplasty in patients with osteoarthrosis secondary to developmental hip dysplasia is often more complex due to anterolateral acetabular bone deficiency. Femoral head (shelf) autograft provides a non-immunogenic, osteoconductive lateral support with the potential for enhanced bone stock should revision surgery be required. The technique has been shown in other series to give reliable early results but may be complicated by graft revascularisation and collapse. As yet, no study has assessed shelf grafts long term or quantified the need for further bone graft at revision surgery. This study aims to assess initial graft union rate; quantify long term graft resorption and; quantify the need for further bone graft in the patients requiring revision surgery. A retrospective analysis of a single surgeon's series of 31 THR in 25 patients was conducted. Post-operative, biplanar radiographic analysis was performed at 3 and 6 months and annually thereafter for a mean of 14 years (range 8-18). Grafts were assessed for union, resorption and displacement. Intra-operative necessity for bone graft at revision surgery was recorded. Union, osseous 93%, fibrous 7%. No grafts displaced. In 71% less than one-third of the graft resorbed, in 29% one-third to one-half resorbed and in no grafts did greater than a half resorb. Of 10 patients revised, 2 required bone graft for inadequate bone stock. Femoral head autograft allows effective acetabular coverage with excellent rates of union, minimal graft resorption in the long term and improves bone stock in revision surgery.
We report the use of porous metal acetabular
revision shells in the treatment of contained bone loss. The outcomes of
53 patients with
Pelvic discontinuity with associated bone loss is a complex challenge in acetabular revision surgery. Reconstruction using ilio-ischial cages combined with trabecular metal acetabular components and morsellised bone (the component-cage technique) is a relatively new method of treatment. We reviewed a consecutive series of 26 cases of acetabular revision reconstructions in 24 patients with pelvic discontinuity who had been treated by the component-cage technique. The mean follow-up was 44.6 months (24 to 68). Failure was defined as migration of a component of >
5 mm. In 23 hips (88.5%) there was no clinical or radiological evidence of loosening at the last follow-up. The mean Harris hip score improved significantly from 46.6 points (29.5 to 68.5) to 76.6 points (55.5 to 92.0) at two years (p <
0.001). In three hips (11.5%) the construct had migrated at one year after operation. The complications included two dislocations, one infection and one partial palsy of the peroneal nerve. Our findings indicate that treatment of pelvic discontinuity using the component-cage construct is a reliable option.
The purpose of this study was to ascertain the radiographic results of the modified extended trochanteric sliding osteotomy (ETSO), performed by the senior author. The main feature of the ETSO is preservation of the posterior 1cm of greater trochanter and its attached external rotators. Results with this particular osteotomy for revision hip arthroplasty have not been previously reported. We reviewed forty-eight ETSOs in forty-six patients that underwent revision hip arthroplasty from March 2000 to March 2006. Nineteen osteotomies were for femoral revision alone, and twenty-nine osteotomies were performed for femoral and acetabular revision. All but six (12.5%) had cortical strut augmentation of the osteotomy. The length of the osteotomy, the length of distal fit, the number of wires used were recorded and their relation to union of the osteotomy and femoral stem loosening were investigated. The rate of ETSO union in this study was 91.3%. Four osteotomies were not united and this was associated with femoral stem subsidence and loosening requiring femoral stem revision in three cases. The rate of femoral stem loosening requiring revision was 8.3%. The length of the osteotomy did not correlate with femoral stem loosening, but a distal fit of less than 9cm was highly significant(p=0.001) with regards to loosening. The use of cortical struts was not protective against osteotomy non-union or femoral stem loosening. Osteotomy union was shown to be dependant on a well fixed (p<
0.0001) and stable stem (p<
0.0001). Three patients dislocated postoperatively (6.5%), and only one of these required revision surgery. The modified extended trochanteric osteotomy has a low rate of dislocation and a reliable rate of union. We have shown that a well fixed and stable stem is critical to successfully obtaining union of the osteotomy.
Rapid advances in computer-assisted surgery (CAS) have lead to increasing integration of this technology into the orthopaedic training environment. The real-time feedback provided by CAS improves performance; however, it may be detrimental to learning. The primary purpose of this study is to determine if the form of feedback provided by computer-assisted technology (concurrent visual feedback) compromises the learning of surgical skills in the trainee. Forty-five residents and senior medical students were randomised to one of three training groups and learned technical skills related to total hip replacement. The “Conventional Training” (CT) group self-determined acetabular cup position and were then corrected with traditional hand-over-hand repositioning. The “Computer Navigation” (CN) group used CAS to self-determine cup position. The “Knowledge of Results” (KR) group self-determined cup position and when satisfied used CAS for optimal repositioning. Outcomes (accuracy and precision of cup placement in abduction and anteversion, and time to position) were assessed in a pre-test, ten minute and six week retention and transfer tests. All retention and transfer tests were performed without CAS. There were no differences between the groups at pre-test. All groups demonstrated an improvement in accuracy and precision of abduction angle and version angle determination during training (p <
0.001). The CN group demonstrated significantly better accuracy and precision in early training (p <
0.05), and better precision throughout training (p <
0.05). While the CN group demonstrated a decrease in precision during transfer testing it was not found to differ significantly from the other groups. No significant degradation in performance was observed between immediate and delayed testing for any group suggesting no negative effects of the tested training modalities on learning. In this study the concurrent augmented feedback provided by CAS resulted in improved early performance without a compromise in learning, however, further investigation is required to ensure CAS does not compromise trainee learning. Until this issue is clarified, educators need to be aware of this potential effect.
Notching of the anterior femoral cortex during total knee arthroplasty is thought to be a possible risk factor for subsequent periprosthetic femoral fracture. Understanding the stress pattern caused by notching may help the orthopedic surgeon reduce the risk of fracture. A validated, three dimensional, finite element model of the femur using gait loads has been used to analyze the stress concentrations caused by anterior femoral cortex notching. Three factors that increase these stresses were identified. The notch depth, radius of curvature, and its proximity to the end of the femoral prosthesis influence the state of stress in the surrounding bone. The purpose of this study was to characterize the stress concentration caused by anterior femoral notching during total knee replacement (TKR) in order to determine when a patient is at risk for a periprosthetic fracture of the femur. We concluded that notches greater than 3 mm with sharp corners located directly at the proximal end of the femoral implant produced the highest stress concentrations and may lead to a significant risk of periprosthetic femur fracture. One complication that can occur during TKR is notching of the anterior femoral cortex which results in a stress concentration. It is important to characterize this stress riser in order to determine when a stemmed femoral component should be used to minimize the risk of fracture. Three factors that affected the stress concentration were identified. First, increasing the notch depth lead to significant increased stress concentrations. When the depth was greater than 3 mm, local stresses increased markedly. Second, the radius of curvature was found to be inversely related to stress concentration. As the radius decreased, the local stress increased. Third, the proximity of the notch to the prostheses affected the stress concentration. Notches that were 1 mm proximal to the implant resulted in much larger stresses than those that were 10 mm away. A validated, three dimensional finite element model of a femur subjected to a gait loading pattern was used to characterize the stress concentration caused by anterior femoral notching. The results compared well to previous work reported in the literature.
Periprosthetic fracture management after hip arthroplasty is complicated by poor bone stock and loose femoral components. Using a prospective database, thirty-five fractures treated by proximal femoral allograft reconstruction were identified. Patients treated between 1989–2000 with minimum two- year results, were reviewed at a mean of 3.8 years. Twenty-six fractures were acute, and nine had failed previous treatment. Union of the PFA was achieved in all but five cases (83%). In twenty-eight cases (78%) no further surgery was required and patient ambulation was pain free. When conventional treatment is not possible, the use of a PFA provides encouraging results. Periprosthetic femoral fracture treatment is complicated by comminution, bone loss, and potentially loose femoral components. Treatment can include cast-braces, internal fixation, revision arthroplasty or the use of proximal femoral allograft composites (PFA). This study reports on thirty-five fractures treated with a PFA between 1989–2000. Five patients were lost and twelve patients (33%) were deceased. Follow-up averaged 3.8 years (range 0.1–11.3) with minimum two-year results in surviving patients. Six patients had either Rheumatoid arthritis or DDH with very narrow femoral canals. There were twenty-three acute fractures, five failures of non-operative management, four failures of ORIF and two fractured femoral stems. Fractures were classified by the Vancouver system with: B1–7%, B2–30%, B3–43% and C-20%. Prefracture functional scores revealed that 30% of patients had significant functional impairment and were awaiting revision arthroplasty. Patients had had an average of two previous surgical procedures (range 1–4). The mean length of the PFA was 14cm and union between graft and host bone was achieved in all but five cases (83%). Resorption of the graft was seen in eight cases (27%), lucent lines in six cases (20%) and implant migration in four cases (13%). Post revision arthroplasty Harris Hip and SF-36 scores revealed substantial disability in this patient group. Twenty-eight cases (73%) were deemed successful with patients not requiring further surgery and enjoying pain free ambulation. In fractures with unstable femoral components and inadequate bone stock or very narrow femoral canals few options are available. This technique provides encouraging results and a viable option when conventional treatment is not possible.
Notching of the anterior femoral cortex during total knee arthroplasty is thought to be a possible risk factor for subsequent periprosthetic femoral fracture. Understanding the stress pattern caused by notching may help the orthopedic surgeon reduce the risk of fracture. A validated, three dimensional, finite element model of the femur using gait loads has been used to analyze the stress concentrations caused by anterior femoral cortex notching. Three factors that increase these stresses were identified. The notch depth, radius of curvature, and its proximity to the end of the femoral prosthesis influence the state of stress in the surrounding bone. The purpose of this study was to characterize the stress concentration caused by anterior femoral notching during total knee replacement (TKR) in order to determine when a patient is at risk for a periprosthetic fracture of the femur. We concluded that notches greater than 3 mm with sharp corners located directly at the proximal end of the femoral implant produced the highest stress concentrations and may lead to a significant risk of periprosthetic femur fracture. One complication that can occur during TKR is notching of the anterior femoral cortex which results in a stress concentration. It is important to characterize this stress riser in order to determine when a stemmed femoral component should be used to minimize the risk of fracture. Three factors that affected the stress concentration were identified. First, increasing the notch depth lead to significant increased stress concentrations. When the depth was greater than 3 mm, local stresses increased markedly. Second, the radius of curvature was found to be inversely related to stress concentration. As the radius decreased, the local stress increased. Third, the proximity of the notch to the prostheses affected the stress concentration. Notches that were 1 mm proximal to the implant resulted in much larger stresses than those that were 10 mm away. A validated, three dimensional finite element model of a femur subjected to a gait loading pattern was used to characterize the stress concentration caused by anterior femoral notching. The results compared well to previous work reported in the literature.
Periprosthetic fracture management after hip arthroplasty is complicated by poor bone stock and loose femoral components. Using a prospective database, thirty-five fractures treated by proximal femoral allograft reconstruction were identified. Patients treated between 1989–2000 with minimum two- year results, were reviewed at a mean of 3.8 years. Twenty-six fractures were acute, and nine had failed previous treatment. Union of the PFA was achieved in all but five cases (83%). In twenty-eight cases (78%) no further surgery was required and patient ambulation was pain free. When conventional treatment is not possible, the use of a PFA provides encouraging results. Periprosthetic femoral fracture treatment is complicated by comminution, bone loss, and potentially loose femoral components. Treatment can include cast-braces, internal fixation, revision arthroplasty or the use of proximal femoral allograft composites (PFA). This study reports on thirty-five fractures treated with a PFA between 1989–2000. Five patients were lost and twelve patients (33%) were deceased. Follow-up averaged 3.8 years (range 0.1–11.3) with minimum two-year results in surviving patients. Six patients had either Rheumatoid arthritis or DDH with very narrow femoral canals. There were twenty-three acute fractures, five failures of non-operative management, four failures of ORIF and two fractured femoral stems. Fractures were classified by the Vancouver system with: B1–7%, B2–30%, B3–43% and C-20%. Prefracture functional scores revealed that 30% of patients had significant functional impairment and were awaiting revision arthroplasty. Patients had had an average of two previous surgical procedures (range 1–4). The mean length of the PFA was 14cm and union between graft and host bone was achieved in all but five cases (83%). Resorption of the graft was seen in eight cases (27%), lucent lines in six cases (20%) and implant migration in four cases (13%). Post revision arthroplasty Harris Hip and SF-36 scores revealed substantial disability in this patient group. Twenty-eight cases (73%) were deemed successful with patients not requiring further surgery and enjoying pain free ambulation. In fractures with unstable femoral components and inadequate bone stock or very narrow femoral canals few options are available. This technique provides encouraging results and a viable option when conventional treatment is not possible.
Fresh osteochondral allografts were used to repair post-traumatic osteoarticular defects in 92 knees. At the time of grafting, varus or valgus deformities were corrected by upper tibial or supracondylar femoral osteotomies. A survivorship analysis was performed in which failure was defined as the need for a revision operation or the persistence of the pre-operative symptoms. There was a 75% success rate at five years, 64% at ten years and 63% at 14 years. The failure rate was higher for bipolar grafts than for unipolar and the results in patients over the age of 60 years were poor. The outcome did not depend on the sex of the patient and the results of allografts in the medial and lateral compartments of the knee were similar. Careful patient selection, correction of joint malalignment by osteotomy, and rigid fixation of the graft are all mandatory requirements for success. We recommend this method for the treatment of post-traumatic osteochondral defects in the knees of relatively young and active patients.