Robotic-arm assisted versus manual total knee arthroplasty: Functional gait analysis from a randomised controlled trial.

The primary aim of this study was to assess whether measures of functional gait assessment were improved with robotic total knee arthroplasty (rTKA) when compared to manual TKA (mTKA). Gait analysis was performed as part of a randomised controlled trial. Walking and relaxed standing assessments were performed using an instrumented mat system. Spatiotemporal variables included gait cycle parameters, anteroposterior and lateral sway, and plantar pressure ratios. Measurements were recorded at pre-operative baseline and 12 months post-operatively. 100 patients were randomised, 50 to each group. Complete gait cycle data were available for 26 rTKA and 23 mTKA patients. Cadence and walking velocity showed overall improvements following surgery, with no difference between the two groups. In the operated limb, overall step and stride times decreased, while step and stride lengths increased. Subgroup analysis showed reduced propulsion time with rTKA, and decreased foot flat and mid stance times with mTKA. Lateral sway was decreased in the rTKA group. Plantar pressure ratios showed an overall increase in hindfoot loading on the operated limb, with no difference between the two groups. No other significant differences were identified between rTKA and mTKA at 12 months, and limitations may include statistical error. A small sample of the study cohort was followed up; analysis may represent the results of satisfied patients with well-functioning TKA. Further study could incorporate proprioceptive and 3D gait analysis techniques to analyse knee kinetics and kinematics with robotic surgery. Pressure mapping could further subdivide the plantar surfaces to explore any nuances in differential loading.

Ankle Arthroplasty-Does Preoperative Fixed Equinus Affect Patient-Reported Outcomes.

Postoperative sagittal range of motion, in particular degree of dorsiflexion, is critical for satisfactory outcomes in total ankle arthroplasty (TAA). Although there is literature discussing techniques to treat a preoperative fixed equinus we are not aware of any papers presenting patient outcomes. We present patient-reported outcomes for our cohort of patients undergoing TAA with preoperative fixed equinus compared to plantigrade ankles. This is a single surgeon, cohort study of consecutive cases. Cases of primary TAA were identified from a local joint registry which prospectively records Foot and Ankle Outcome Scores (FAOS), Short Form-36 (SF-36), and patient satisfaction. Revision cases or those with inadequate data were excluded. Patients were classified as fixed equinus or neutral based on both preoperative weightbearing lateral radiographs and clinical records. Overall 259 cases were identified, 92 were excluded leaving 167 cases for analysis (mean follow-up 81.7 months), 147 were classified as neutral and 20 fixed equinus. The fixed equinus group were significantly younger (neutral 63.9 vs equinus 52.9, p < .001). Stiffness was the only FAOS domain that was detectibly different at baseline (neutral 36.6 vs equinus 25.6, p = .044). Final FAOS scores, change from baseline and patient satisfaction was the same in all domains for both groups. There was no difference in revision rates. With the numbers available we did not demonstrate a postoperative difference in outcomes for patients with preoperative fixed equinus.

Randomized Controlled Trial Comparing Early Mobilization vs Six Weeks of Immobilization in a Walking Cast Following Total Ankle Replacement.

Rehabilitation for patients after total ankle replacement traditionally involves weeks of immobilization in a plaster cast followed by progressive mobilization. In a small randomized trial, we compared teh outcomes of patients who received a 3-component cementless, unconstrained, mobile-bearing prosthesis and were initially immobilised in a plaster cast for 6 weeks to thoese who received the same prosthesis but were allowed to mobilise early. Gait, clinical, patient-reported, and radiologic outcomes were measured. The study included 20 patients, 10 in the plaster cast group and 10 in the early mobilization group, and the demographics of the groups did not differ significantly. All patients were followed-up for 24 months. There were no significant differences between the 2 groups 2 years after surgery in ankle dorsiflexion, spatiotemporal gait characteristics, American Orthopaedic Foot and Ankle Society ankle-hindfoot scores, Timed Up and Go Test times, WOMAC (pain, stiffness, function) scores, SF-36 (quality-of-life) scores, or patient satisfaction (pain relief, daily-living, recreational activities, and overall) (all p > .05). Bone mineral density decrease of the medial malleolus and increase at middle tibia, calculated with DEXA scans, was significantly better in early mobilization than plaster cast group at one and 2 years postoperatively, but this was also the case preoperatively. The lack of differences in outcomes suggests that early ankle mobilization may be a safe and reliable method to enhance recovery following ankle arthroplasty with a 3-component cementless, unconstrained, mobile-bearing prosthesis. Compared to traditional plaster casting, patients who are engaged in early mobilization after arthroplasty may enjoy similar functional, mobility, quality-of-life, pain relief, activity level, and satisfaction outcomes.

Nonunion Rates in Hind- and Midfoot Arthrodesis in Current, Ex-, and Nonsmokers.

BACKGROUND: Nonunion rates in hind or midfoot arthrodesis have been reported as high as 41%. The most notable and readily modifiable risk factor that has been identified is smoking. In 2018, 14.4% of the UK population were active smokers. We examined the effect of smoking status on union rates for a large cohort of patients undergoing hind- or midfoot arthrodesis. METHODS: In total, 381 consecutive primary joint arthrodeses were identified from a single surgeon's logbook (analysis performed on a per joint basis, with a triple fusion reported as 3 separate joints). Patients were divided based on self-reported smoking status. Primary outcome was clinical union. Delayed union, infection, and the need for ultrasound bone stimulation were secondary outcomes. RESULTS: Smoking prevalence was 14.0%, and 32.2% were ex-smokers. Groups were comparable for sex, diabetes, and body mass index. Smokers were younger and had fewer comorbidities. Nonunion rates were higher in smokers (relative risk, 5.81; 95% CI, 2.54-13.29; P < .001) with no statistically significant difference between ex-smokers and nonsmokers. Smokers had higher rates of infection (P = .05) and bone stimulator use (P < .001). Among smokers, there was a trend toward slower union with heavier smoking (P = .004). CONCLUSION: This large retrospective cohort study confirmed previous evidence that smoking has a considerable negative effect on union in arthrodesis. The 5.81 relative risk in a modifiable risk factor is extremely high. Arthrodesis surgery should be undertaken with extreme caution in smokers. Our study shows that after cessation of smoking, the risk returns to normal, but we were unable to quantify the time frame. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Total Joint Replacement of Ankle, Knee, and Hip: How Do Patients Perceive Their Operative Outcomes at 10 Years?

BACKGROUND: Patient-reported outcomes (PROMs) are an integral part of national joint registers in measuring outcomes of operative procedures and improving quality of care. There is lack of literature comparing outcomes of total ankle replacement (TAR) to total knee replacement (TKR) and total hip replacement (THR). The aim of this study was to compare PROMs between TAR, TKR, and THR patient groups at 1, 5, and 10 years. METHODS: Prospective PROMs from patients who underwent a TAR, TKR, or THR procedure between 2003 and 2010 were studied. Patients were divided into 3 groups based on their index joint replacement (hip, knee, or ankle). Patient demographics (age, gender, body mass index), patient-reported outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], 36-Item Short Form Health Survey [SF-36]) and patient satisfaction scores (4-point Likert scale) at follow-up were compared between the 3 groups. RESULTS: Data was available on 1797 THR, 2475 TKR, and 146 TAR patients. TAR patients were younger and reported fewer number of comorbidities. All 3 groups improved significantly from preoperative to 10 years for WOMAC scores (P < .001). For SF-36 scores at 10 years, the THR group (32.2% follow-up) scored the highest for 3 domains (P = .031) when compared to the TKR group (29.1% follow-up). All 3 groups had similar outcomes for 5 of 8 domains; P < .05). For patient satisfaction, the THR group reported overall 95.1% satisfaction followed by 89.8% for the TKR group and 83.9% in the TAR group (42.4% follow-up). CONCLUSION: In this cohort with diminishing numbers over the decade of time the patients were followed up we found that patients are equally happy with functional and general health outcomes from total ankle replacement vs other major lower extremity joint replacement. TAR surgery should be considered as a viable treatment option in this patient group. LEVEL OF EVIDENCE: Level III, retrospective case series.

Radiographic Severity of Arthritis Affects Functional Outcome in Total Ankle Replacement (TAR).

BACKGROUND: It has been previously demonstrated that radiographic severity of arthritis predicts outcome following knee replacement. In certain circumstances, patients may undergo arthroplasty without severe radiographic disease. An example may be the patient with significant chondral damage unsuccessfully treated with arthroscopy. This patient may proceed to joint replacement when their radiographs would not normally merit such intervention. We investigated whether these findings were also applicable to total ankle replacements (TARs). METHODS: We retrospectively reviewed a single-surgeon, single-implant series of 178 TARs in 170 patients. Of them, 124 patients who took part in the hospital joint registry with a minimum 2-year follow-up were included for this study. The radiographic severity of arthritis was graded using the Kellgren-Lawrence classification. Preoperative weight-bearing radiographs were reviewed for severity of arthritis by 2 blinded observers: the first author and an independent colleague from the radiology department. Patients were grouped into 4 subgroups based on degree of severity of radiographic grading for arthritis-A, B, C, and D (for grades 1, 2, 3, and 4 grades, respectively). Data collected included Foot and Ankle Outcome Score (FAOS; pain, function, and stiffness), MOS 36-item Short-Form Health Survey (SF-36) scores, and patient satisfaction scores collected prospectively and at 1 and 2 years postoperation. RESULTS: Groups were similar in terms of demographic data (P > .1) and preoperative FAOS scores (P > .89) for pain, function and stiffness. Group D had the biggest improvement in all domains of FAOS. This reached significance in each domain when compared to group C. No significant differences were demonstrated in SF-36 scores. Overall, 91.1% of patients in group D were satisfied at 2 years, compared with 50.0% of patients in groups A, B, and C (P < .001). In addition, 93.9% of patients in group D felt that their quality of life had been improved by the surgery, compared to 47% of patients with groups A, B, and C (P < .001). Further, 77.3% of patients from group D said they would have the operation again, vs only 52.2% of patients with grade III or less (P = .014). Patients who were "very satisfied" or "somewhat satisfied" postoperatively had an average Kellgren-Lawrence (KL) grade of 3.9 preoperatively. In contrast the "very dissatisfied" and "somewhat dissatisfied" patients had an average KL grade of 2.9 (P < .05). CONCLUSION: Although this study does not explain all of the dissatisfaction in TAR, radiologic severity is an important factor that surgeons must consider when planning how best to treat their patients. There may be a different pathophysiology in this patient group that is not well served by arthroplasty. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Early results of a novel technique: Hindfoot fusion in talus osteonecrosis prior to ankle arthroplasty: A case series.

BACKGROUND: The purpose of this study was to evaluate the clinical outcome of a two staged approach of subtalar arthrodesis followed by TAR for patients with ankle arthritis and AVN talus. METHODS: Out of total 210 TARs performed at our institute; 7 patients underwent a two staged procedure between 2006 and 2010. All patients had over 3 years of follow up (except one). The clinical results were assessed using AOFAS, WOMAC, SF-36 and patient satisfaction scores. RESULTS: The mean follow up was 3 years. There was significant improvement in AOFAS and WOMAC (pain and stiffness) from pre-op to 3 years post-op (P<0.05). SF 36 scores improved from pre-op to 3 years post-op for 6/8 domains. 5 patients were satisfied at 3 years for overall surgical outcomes, 4 were satisfied with pain relief. Radiological signs of talar subsidence were noted in 2 patients at year 1. This did not progress at 3 years and did not deteriorate clinical outcome. CONCLUSION: We recommend our two staged approach to deal with this difficult clinical problem. We believe this approach is safe for TAR surgery where talar vascularity and bone quality is questionable leading to reduced talar subsidence, ischaemic pain and improvement in longevity of TAR. LEVEL OF EVIDENCE: Evidence IV (Retrospective case series).

Two-year outcomes of MOBILITY Total Ankle Replacement.

BACKGROUND: There is little literature on patient-reported outcomes following total ankle replacement in patients with osteoarthritis, posttraumatic osteoarthritis, and rheumatoid arthritis. We compared the differences in demographic data and clinical and patient-reported outcomes among patients with those types of arthritis who underwent total ankle replacement performed with use of the MOBILITY Total Ankle System. METHODS: Patients were divided into three groups based on the preoperative diagnosis of type of arthritis. We analyzed patient demographic data, American Orthopaedic Foot & Ankle Society (AOFAS) scores, and patient-reported outcomes as measured with use of the Foot and Ankle Outcome Score (FAOS), the 36-item Short-Form (SF-36) Health Survey, and patient-satisfaction scores, collected preoperatively and at one and two years postoperatively. RESULTS: The study included 106 consecutive patients who underwent total ankle replacement between March 2006 and December 2009. The posttraumatic osteoarthritis group, which had twenty-eight patients, was significantly younger (mean age, 54.8 yrs; p < 0.05) than the other groups; the rheumatoid arthritis group, which had twenty-two patients, had a significantly lower mean body mass index (24.5 kg/m(2); p < 0.05); and the osteoarthritis group, which had fifty-six patients, had a higher proportion of males (41 males; p < 0.05). The posttraumatic osteoarthritis group reported better scores for two of the eight domains of the SF-36 preoperatively. At one year postoperatively, the posttraumatic osteoarthritis group and the rheumatoid arthritis group had better FAOS results regarding pain than those of the osteoarthritis group, and the posttraumatic osteoarthritis group also reported better scores for the general health domain of the SF-36. At two years, the posttraumatic group continued to show significantly higher scores for the general health domain of the SF-36. There was no significant difference between the groups in terms of the AOFAS scores, other FAOS results, or the patient-satisfaction scores at one and two years postoperatively. CONCLUSIONS: Our findings suggest that early outcomes after total ankle replacement for patients with posttraumatic osteoarthritis are comparable with those for patients with osteoarthritis and rheumatoid arthritis.

Metal-on-metal total hip arthroplasty.

The effects of elevated levels of metal ions in patients who have undergone metal-on-metal total hip arthroplasty are not fully understood. The effects of femoral head size on serum metal-ion levels have been the subject of conflicting reports, and further investigation is needed to evaluate the impact of acetabular and femoral component alignment. The conduct of clinical trials of metal-on-metal total hip arthroplasties has been inadequate as few investigators have used a randomized controlled design to compare metal-on-metal bearings with other bearing surfaces. Additional clinical research needs to include appropriate validated patient-reported outcome measures, activity monitoring, and health economics.