Restoration of native Coronal Plane Alignment of the Knee (CPAK) phenotype is a strategy suggested to achieve better satisfaction. The aim of this study was to investigate the influence of changes in CPAK classification on patient-reported outcome measures (PROMs) and survivorship in a large cohort of manual mechanically aligned (MA) cemented TKAs.

A retrospective analysis of 1062 consecutive cemented TKAs using MA philosophy at a single institution. Pre- and post-operative hip-knee-ankle radiographs were classified using the CPAK classification. Oxford Knee Score (OKS) and patient satisfaction (4-point-Likert scale) were collected prospectively. Implant survival data was obtained from our national arthroplasty database. We compared the outcomes of patients who maintained or changed their CPAK classification following TKA. Satisfaction was analysed using chi-square test, and OKS was analysed using Mann-Whitney test.

Pre-operatively, most patients were CPAK type-I (38.8%). 85.5% of patients changed their CPAK type post-operatively, with CPAK type-V observed in 41.2% of these. Significantly better satisfaction (p=0.033) and OKS (p=0.021) were observed at one-year follow-up in patients who changed CPAK type, although the difference was below OKS minimally important clinical difference. There was no difference in satisfaction (p=0.73) and OKS (p=0.26) at one year between CPAK-V and non-V classifications. Post-operative CPAK type had no correlation with satisfaction and OKS. 12 TKAs (1.1%) were revised within 10 years (3 septic).

In this large cohort of MA-TKA, excellent survivorship was observed at 10 years, with no demonstrable difference in outcome related to the final CPAK phenotype or change in phenotype.

In this RCT the primary aim was to assess whether a short (125mm) Exeter V40 stem offered an equivalent hip specific function compared to the standard (150mm) stem when used for cemented total hip arthroplasty (THA). Secondary aims were to evaluate health-related quality of life (HRQoL), patient satisfaction, stem height and alignment, radiographic loosening, and complications between the two stems.

A prospective multicentre double-blind randomised control trial was conducted. During a 15-month period, 220 patients undergoing THA were randomised to either a standard (n=110) or short (n=110) stem Exeter. There were no significant (p≥0.065) differences in preoperative variables between the groups. Functional outcomes and radiographic assessment were undertaken at 1- and 2-years.

There were no differences (p=0.428) in hip specific function according to the Oxford hip score at 1-year (primary endpoint) or at 2-years (p=0.767) between the groups. The short stem group had greater varus angulation (0.9 degrees, p=0.003) when compared to the standard group and were more likely (odds ratio 2.42, p=0.002) to have varus stem alignment beyond one standard deviation from the mean. There were no significant (p≥0.083) differences in the Forgotten joint scores, EuroQol-5-Dimension, EuroQol-VAS, Short form 12, patient satisfaction, complications, stem height or radiolucent zones at 1 or 2-years between the groups.

The Exeter short stem offers equivalent hip specific function, HRQoL, patient satisfaction, and limb length when compared to the standard stem at 2-years post-operation. However, the short stem was associated with a greater rate of varus malalignment which may influence future implant survival.

Accurate evaluation of lower limb coronal alignment is essential for effective pre-operative planning of knee arthroplasty. Weightbearing hip-knee-ankle (HKA) radiographs are considered the gold standard. Mako SmartRobotics uses CT-based navigation to provide intra-operative data on lower limb coronal alignment during robotic assisted knee arthroplasty. This study aimed to compare the correlation between the two methods in assessing coronal plane alignment.

Patients undergoing Mako partial (PKA) or total knee arthroplasty (TKA) were identified from our hospital database. The hospital PACS system was used to measure pre-operative coronal plane alignment on HKA radiographs. This data was correlated to the intraoperative deformity assessment during Mako PKA and TKA surgery.

443 consecutive Mako knee arthroplasties were performed between November 2019 and December 2021. Weightbearing HKA radiographs were done in 56% of cases. Data for intraoperative coronal plane alignment was available for 414 patients. 378 knees were aligned in varus, and 36 in valgus. Mean varus deformity was 7.46° (SD 3.89) on HKA vs 7.13° (SD 3.56) on Mako intraoperative assessment, with a moderate correlation (R= 0.50, p<0.0001). Intraoperative varus deformity of 0-4° correlated to HKA measured varus (within 3°) in 60% of cases, compared to 28% for 5-9°, 17% for 10-14°, and in no cases with >15° deformity. Mean valgus deformity was 6.44° (SD 4.68) on HKA vs 4.75° (SD 3.79) for Mako, with poor correlation (R=0.18, p=0.38).

In this series, the correlation between weightbearing HKA radiographs and intraoperative alignment assessment using Mako SmartRobotics appears to be poor, with greater deformities having poorer correlation.

Abstract

We reviewed 87 patients who underwent revision anterior cruciate ligament (ACL) reconstruction. The incidence of meniscal tears and degenerative change was assessed and related to the timing from primary ACL graft failure to revision ACL reconstruction. Patients were divided into either an early group (revision surgery within 6 months of graft failure) or a delayed group. Degenerative change was scored using the French Society of Arthroscopy system. There was a significantly higher incidence of articular cartilage degeneration in the delayed group compared to the early group (53.2% vs 24%, p < 0.01, Mann- Whitney U test). No patients in the early group had advanced degenerative change (SFA grades 3 or 4), compared with 12.9% of patients in the delayed group. There was no significant difference in the incidence of meniscal tears between the two groups. In conclusion, the findings of the study support the view that patients with a failed ACL reconstruction and symptomatic instability should have an early revision reconstruction procedure carried out to minimise the risk of articular degenerative change.

Introduction: In the past, displaced radial neck fractures have been treated either by excision, prosthetic replacement or internal fixation with a plate and screws. More recent studies have investigated less invasive fixation constructs using two crossed obliquely orientated screws within the radial neck. A new ‘tripod’ technique using three crossed screws has been proposed and was tested to evaluate whether it has at least equivalent stiffness and strength to fixation with a T-plate.

Methods: Twenty composite sawbones with an axially stable simulated radial neck fracture were fixed either with the tripod technique (three crossed 2.3mm screws) or with a 2.3mm T-plate. The specimens were tested for stiffness at 10 N load in three directions (anteroposterior (AP), ulnar-radial (UR) and eccentric axial (EA)) and load to yield and ultimate failure. The modes of failure of fixation were also evaluated.

Results: The tripod had significantly higher stiffness than the T-plate in AP loading (168 N/mm vs 95 N/mm, p=0.006) and trended to superior stiffness in UR loading (121 N/mm vs 77 N/mm, p=0.06). Both constructs were highly stiff in EA compression (513 N/mm vs 638 N/mm). The strength to yield and failure was significantly higher for the tripod in both AP loading (yield: 432 N vs 36 N, failure: 467 N vs 143 N, p< 0.001) and UR loading (yield: 444 N vs 36N, failure: 444N vs 76 N, p< 0.001). The T-plates failed by screw cut-out and subsequent plastic deformation of the plate. The tripod constructs did not fail at the load required to cause brittle fracture in the sawbone specimen, remote to the site of fixation.

Conclusions: The tripod technique is a biomechanically sound construct for the fixation of axially stable radial neck fractures and thus further clinical research to evaluate the clinical application of this technique is justified.

Introduction: Foot and ankle involvement in rheumatoid arthritis is common. Pain and disability secondary to planovalgus deformity and the arthritic process are difficult to control with conservative measures. Arthroplasty of the ankle is associated with high failure rates and does not completely correct the deformity. Arthrodesis of the hindfoot is a good option to alleviate pain, correct the deformity and improve functional ability, however has not been well reported in the literature.

Aims: To determine change in quantitative measures of patient health, pain and functional ability following hindfoot arthrodesis in patients with rheumatoid arthritis, and to assess patient satisfaction postoperatively.

Methods: 24 consecutive additive hindfoot arthrodeses were performed by a single surgeon on 22 patients with rheumatoid arthritis. Patients were assessed preoperatively using the Short Form-12 Health Survey (SF-12), Manchester-Oxford Foot Questionnaire (MOXFQ) and pain scores. These assessments were repeated at 6 and 12 months postoperatively, with an additional satisfaction questionnaire.

Results: There was a marked and sustained improvement in the post-operative SF-12, MOXFQ and pain scores, with 71% of patients reporting no pain at 12 months. 19 out of 22 patients reported being satisfied or very satisfied with the operation. Bony union was achieved in all patients, both on clinical and radiological criteria. Most patients returned to normal footwear, some with slight modification to facilitate a more normal gait cycle.

Conclusions: This study shows that additive hindfoot arthrodesis can be a very effective procedure in the management of moderate to severe ankle and hind-foot disease in rheumatoid arthritis. Patients should be counselled regarding the considerable recovery period; however significant improvement in the patient’s general health, foot function and pain can be expected.

Whilst clinical pathways have reduced the length of inpatient stay (LOS) and costs associated with total hip replacement (THR), it would be useful to be able to predict which factors affect the LOS following THR. In this way units could improve patient flow, and thus increase efficiency, by optimising case loads and staffing levels in all related departments. We hypothesised that there were pre-operative factors that will predict the length of inpatient stay following a unilateral primary THR.

Prospective data from 2302 patients who underwent primary unilateral THR for osteoarthritis during a nine-year period from January 01 1998 were included. The relationship between each prospectively recorded factor and LOS was analyzed separately using t-tests or Pearson correlation. Multiple linear regression was used to analyze the effect of each significant factor adjusted for others.

Length of stay varied from 3 to 58 days, with a mean of 8.1 and a median of 7.0. The pre-operative factors that were not significantly associated with the LOS were BMI, Scottish Index of Multiple Deprivation, disabling knee, back or contra-lateral hip pain. A number of pre-operative factors were found to be highly significant predictors of LOS when subjected to univariate analysis, but not significant after multivariate analysis. These were smoking, heart disease, diabetes, pre-operative aspirin, pre-operative haemoglobin and overall Short Form (SF-36) score. Pre-operative factors that were significantly associated with LOS after adjusting for the effect of others were age, sex, pre-operative NSAIDs, consultant surgeon, combined function/activity dimension to Harris hip score, general health perception (GHP) dimension of SF-36, the day of the week and the year of surgery.

Younger age, male sex, higher combined Harris hip function and activity score, higher GHP dimension of SF-36 score and NSAID use are all significantly associated with reduced length of inpatient stay following primary THR for osteoarthritis.

A new ‘tripod’ technique using three crossed screws to stabilise radial neck fractures has been proposed and this technique was tested in vitro to evaluate whether it has at least equivalent stiffness and strength to fixation using a T-plate.

Twenty composite sawbones with an axially stable simulated radial neck fracture were fixed either using the tripod technique (three crossed 2.3mm screws) or with a 2.3mm T-plate and screws. The specimens were tested for stiffness at 10 N load in three directions (antero-posterior (AP), ulnar-radial (UR) and eccentric axial (EA)) and load to yield and ultimate failure. The modes of failure of fixation were also evaluated.

The tripod had significantly higher stiffness than the T-plate in AP loading (168 N/mm vs 95 N/mm, p=0.006) and trended to superior stiffness in UR loading (121 N/mm vs 77 N/mm, p=0.06). Both constructs were highly stiff in EA loading (513 N/mm vs 638 N/mm). The strength to yield and failure was significantly higher for the tripod in both AP loading (yield: 432 N vs 36 N, failure: 467 N vs 143 N, p< 0.001) and UR loading (yield: 444 N vs 36N, failure: 444N vs 76 N, p< 0.001). The T-plates failed by screw cut-out and subsequent plastic deformation of the plate. The tripod constructs did not fail at the load required to cause brittle fracture in the sawbone specimen, remote to the site of fixation.

The tripod technique is a biomechanically sound construct for the fixation of axially stable radial neck fractures and thus further research to evaluate the clinical results of this technique is justified.

Introduction: Increasingly, clinical pathways and fast-track protocols are reducing hospital in-patient stay following elective joint replacement surgery. In order to improve efficiency in our unit, we undertook a prospective observational study to identify pre–and peri-operative factors associated with increased length of stay.

Methods: From our prospective primary hip arthroplasty database we analysed data from 2678 consecutive patients over a 9-year period from 1998–2007. Patients were excluded who had bilateral hip replacement, died within 30 post-operative days, or had surgery for a diagnosis other than primary osteoarthritis. This left 2302 patients who were analysed using multiple logistic regression analysis

Results: Length of stay varied from 3 to 58 days, with a mean of 8.1 days, and median 7 days. After multivariate analysis, factors that were found to be significantly associated with shorter length of stay were younger age (p< 0.001), male sex (p< 0.001), more recent year of admission (p=0.008), regular non-steroidal anti-inflammatory medication (p< 0.001), lower Harris Hip Score (p< 0.001), and higher General Health Perception dimension score on SF-36 questionnaire (p< 0.001). In addition, the absence of blood transfusion during admission (p< 0.001) and absence of post-operative urinary catheter (p< 0.001) were also associated with shorter length of stay. The following factors, in particular, were not found to be significantly associated with increased length of stay: obesity, diabetes, smoking, medical comorbidity, other disabling joint condition, use of wound drain post-operatively.

Conclusions: We have identified a number of pre-operative factors that predict likely length of stay in a large cohort of patients undergoing primary hip replacement. This data could be used in the future for resource allocation and to improve efficiency in this significant area of healthcare.

Introduction: Acetabular introducers have an inbuilt inclination of 45 degrees to the shaft. With the patient in the lateral position the operator aims to align the introducer shaft to vertical to implant the acetabulum at 45 degrees. We examined if a bulls-eye spirit level attached to an introducer improved the accuracy of implantation.

Methods: A small circular bulls-eye spirit level was attached to the handle of an acetabular introducer directly over the shaft. A sawbone hemipelvis was fixed to a horizontal, flat surface. A cement substitute was placed in the acetabulum and subjects asked to implant a polyethylene cup into the acetabulum, aiming to obtain an angle of inclination of 45 degrees. Two attempts were made with the spirit level dial masked and two attempts made with it unmasked. The distance of the air bubble from the spirit level’s centre was recorded by a single assessor. The angle of inclination of the acetabular component was then calculated. Subjects included a city hospital’s Orthopaedic consultants and trainees.

Results: Eighteen subjects completed the study, with no significant difference in performance between consultants and trainees. Accuracy of acetabular implantation when using the unmasked spirit-level improved significantly in all grades of surgeon. With the spirit level masked, 11 out of 36 attempts were accurate at 45 degrees, 19 attempts ‘closed’ (< 45degrees) and 6 were ‘open’ (> 45 degrees). With the spirit level visible, all subjects achieved an inclination angle of exactly 45 degrees on both attempts. The mean difference between masked and unmasked implantation angle was 0.94 degrees (95% CI 0.64 to 1.24, p< 0.0001).

Discussion: A simple device attached to the handle of an acetabular introducer can significantly improve the accuracy of implantation of a cemented cup into a saw-bone pelvis in the lateral position. This technique may be easily transferable into an in-vivo study

Study Purpose: To investigate whether the use of reinfusion drains and post-operative autogenous blood transfusion reduces the rate of allogeneic blood transfusion after primary total knee replacement in our unit.

Methods: A prospective audit was carried out over a 14-week period. Patients received either a reinfusion drain, a suction drain or no drain according to surgeon preference. Post-operative allogeneic blood transfusion criteria were based on clinical indication rather than an absolute haemoglobin level.

Results:127 consecutive patients underwent total knee replacement during the study period. Patients were matched between the three groups for age, medical co-morbidity, DVT prophylaxis, and implant used.

Conclusion: The use of reinfusion drains did not significantly reduce the requirement for post-operative allogeneic blood transfusion. This directly contrasts much of the published literature.