Metaphyseal fixation in revision knee arthroplasty: a systematic review of the literature and meta-analysis of mid-long-term outcomes of metaphyseal sleeves and cones.

Metaphyseal augmentation has in recent years formed a key strategy in management of bone loss in revision knee arthroplasty. There are studies reporting excellent short-term results, however long- term data is lacking. There is also a paucity of studies comparing the most frequently utilised augments, metaphyseal sleeves, and cones. We conducted a systematic review and meta-analysis to evaluate and compare the mid to long term outcomes of metaphyseal cones and sleeves. We conducted systematic search of 4 databases (Medline, Embase, CINALH and PubMed). Seventeen studies were found to be eligible for inclusion of which ten investigated metaphyseal sleeves and the remaining seven investigated cones. Mean follow up across all studies was 6.2 years. The total number of patients included in the studies was 1319 and the number of knees operated on was 1431. We noted a higher revision rate of metaphyseal cones when compared to sleeves 10.85% vs 6.31 (p=0.007). Reoperation rates were also higher in cones compared to sleeves, 13.78% vs 3.68% (p<0.001). Prosthetic joint infection was the most common reason for revision. The difference in conversion rates, based on augment location was statistically significant p=0.019. When undertaking further sub-analysis; there was no statistically significant difference when comparing revision rates of; tibial vs femoral augments p=0.108, tibial vs tibial & femur p=0.54 but a difference was seen between femoral vs tibial & femoral augments p=0.007. Based on our data, metaphyseal sleeves demonstrate significantly lower revision rates compared to metaphyseal cones. However overall, both demonstrate reliable mid to long-term outcomes.

Early clinical and radiological outcomes of a new tapered fluted titanium monobloc revision stem in hip arthroplasty.

PURPOSE: A new fluted, titanium, monobloc stem with a three degree taper has been designed in an attempt to overcome the challenges associated with femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its early clinical and radiographic outcomes. METHODS: This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. Forty-three femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling. RESULTS: Mean follow-up was 24 months (range 8-42 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (> 10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15-22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21-34). No stem fractures were noted within the follow-up period. CONCLUSION: Positive early clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.

The majority of conversion total hip arthroplasties can be considered primary replacements - a matched cohort study.

The success of conversion Total Hip Arthroplasty (THA) among primary THA and revision THA re- mains unclear. We hypothesized that most conversion THAss can be performed using primary implants and will have an uncomplicated post-operative course. Thirty-six patients (23 females, mean age 68,0y) who underwent conversion THA for failed interventions for proximal femur fractures in the period 2006-2018 were matched sequentially against patients of the same sex and age who underwent primary THA or revision THA. Data was collected on implants used, major complications, and mortality. PROMs used included the Western Ontario and McMaster Osteoarthritis Index, Harris Hip Score, Visual Analogue Scale and the EQ-5D Health Questionnaire. Seventy- two percent of patients who underwent conversion THA were treated with primary implants and never suffered from a major complication. PROMs were excellent for this group of patients. The distinction primary / conversion / revision THA could not explain differences in outcomes, however the necessity of using revision implants and the development of major complications could. The majority of conversion total hip arthroplasties can be considered a primary replacement. Predicting outcomes for THA should focus on patient frailty and technical difficulties dealing with infection, stability and loss of bone stock and should discard the conversion versus revision terminology.

Access to hip and knee replacement surgery in patients with chronic diseases according to patient-reported pain and functional status.

BACKGROUND: An increasing number of patients undergoing hip or knee replacement have chronic diseases. It has been suggested that the presence of chronic diseases may affect access to this type of surgery in the English National Health Service (NHS). We examined the access to hip and knee replacement surgery in patients with and without chronic diseases according to preoperative patient-reported pain, functional status and symptom duration. METHODS: We analysed data of 640,832 patients who had hip or knee surgery between 2009 and 2016 in England. Multivariable regression was used to estimate the impact of 11 chronic diseases on severity of joint problems as measured on a scale from 0 to 48 by Oxford Hip (OHS) and Knee Scores (OKS) just before surgery and on likelihood of long-standing joint problems (> 5 years pre-operatively). RESULTS: Patients with chronic diseases reported more severe joint problems than patients without (OHS differences ranged from 1.1 [95% CI 0.93, 1.2] to 2.5 [95% CI 2.3, 2.7] and OKS differences from 0.5 [95% CI 0.3, 0.7] to 2.6 [95% CI 2.4, 2.7] for the 11 chronic diseases) but the differences remain small. When analysed separately, patients with chronic diseases reported both more severe pain and poorer functional status. Six chronic diseases in hip patients and two in knee patients increased the likelihood that they had long-standing joint problems. The severity of joint problems just before surgery increased with the number of chronic diseases (OHS differences; one chronic disease (1.5 [95% CI 1.4, 1.5]) to four or more (5.8 [95% CI 5.6, 6.0])). CONCLUSIONS: Patients with chronic diseases reported more severe joint problems immediately before hip or knee replacement surgery suggesting they have hip or knee replacement later in the course of their joint disease.

Is Outpatient Arthroplasty Safe? A Systematic Review.

BACKGROUND: Advances in perioperative care and growing demand for hospital beds have progressively reduced the length of stay in lower limb arthroplasty. Current trends in population demographics and fiscal climate have also added to this change. Individual institutions have reported good outcomes with outpatient hip and knee arthroplasty. Debate remains regarding the safety of this practice, the optimal protocol, and the applicability in different subsections of population. The primary purpose of this review is to assess the complication and reoperation rates of outpatient arthroplasty. METHODS: We performed a systematic review of all papers reporting on 30 and/or 90-day complication rates of outpatient total hip, total knee, and unicondylar knee arthroplasty published from January 1, 2009 to November 1, 2019. Patient demographics, anesthesia, analgesic protocol, selection criteria, and reasons for failed discharge were also extracted. RESULTS: Nineteen manuscripts with a total of 6519 operations between them were analyzed as a part of this systematic review. Mean 90-day readmission rates were 2.3% (range 0%-6%) with 1.61% (range 0%-4%) rate. Overall rate of successful same calendar day discharge was 93.4%. Nausea/dizziness was the most common reason identified (n = 45) for failure of discharge. CONCLUSION: The patients recruited for outpatient joint arthroplasty were younger, more active, and had suffered from less medical comorbidities than the more typical lower limb arthroplasty patient. There are significant differences in the reported complications between the studies reviewed. More research is needed to establish if an outpatient program can produce similar outcomes to a fast-track program. Further research is also needed to establish the optimal perioperative protocols.

The agreement between chronic diseases reported by patients and derived from administrative data in patients undergoing joint arthroplasty.

BACKGROUND: This study examined the agreement between patient-reported chronic diseases and hospital administrative records in hip or knee arthroplasty patients in England. METHODS: Survey data reported by 676,428 patients for the English Patient Reported Outcome Measures (PROMs) programme was linked to hospital administrative data. Sensitivity and specificity of 11 patient-reported chronic diseases were estimated with hospital administrative data as reference standard. RESULTS: Specificity was high (> 90%) for all 11 chronic diseases. However, sensitivity varied by disease with the highest found for 'diabetes' (87.5%) and 'high blood pressure' (74.3%) and lowest for 'kidney disease' (18.8%) and 'leg pain due to poor circulation' (26.1%). Sensitivity was increased for diseases that were given as specific examples in the questionnaire (e.g. 'parkinson's disease' (65.6%) and 'multiple sclerosis' (69.5%), compared to 'diseases of the nervous system' (20.9%)). CONCLUSIONS: Patients can give information about the presence of chronic diseases that is consistent with chronic diseases derived from hospital administrative data if the description in the patient questionnaire is precise and if the disease is familiar to most patients and has significant impact on their life. Such patient questionnaires need to be validated before they are used for research and service evaluation projects.

Comorbidities and the referral pathway to access joint replacement surgery: an exploratory qualitative study.

BACKGROUND: Variation in access to joint replacement surgery has been widely reported but less attention has been given to the impact of comorbidities on the patient journey to joint replacement surgery. There is a lack of consensus amongst healthcare professionals and commissioners about how patients with comorbidities should be referred or selected for joint replacement surgery. It is therefore important to understand the views of healthcare professionals on the management, referral and selection of patients with comorbidities for joint replacement surgery. METHODS: An exploratory qualitative study involving semi-structured interviews with 20 healthcare professionals in England across the referral pathway to joint replacement surgery. They were asked to talk about their experiences of referring and selecting patients with comorbidities for joint replacement surgery. The interviews were audio-recorded and transcribed verbatim. Data analysis followed a thematic analysis approach based on the principles of grounded theory. RESULTS: In general, the presence of comorbidities was not seen as a barrier to being referred or selected for joint replacement but was seen as a challenge to manage the patients' journey across the referral pathway. Each professional group, concentrated on different aspects of the patients' condition which appeared to affect how they managed patients with comorbidities. This implied there was a disagreement about roles and responsibilities in the management of patients with comorbidities. None of the professionals believed it was their responsibility to address comorbidities in preparation for surgery. This disagreement was identified as a reason why some patients seem to 'get lost' in the referral system when they were considered to be unprepared for surgery. Patients were then potentially left to manage their own comorbidities before being reconsidered for joint replacement. CONCLUSIONS: At the clinician-level, comorbidities were not perceived as a barrier to accessing joint replacement surgery but at the pathway-level, it may create an implicit barrier such that patients with comorbidities may get 'lost' to the system. Further study is needed to explore the roles and responsibilities of professionals across the current orthopaedic referral pathway which may be less suitable for patients with comorbidities.

Iatrogenic Bone and Soft Tissue Trauma in Robotic-Arm Assisted Total Knee Arthroplasty Compared With Conventional Jig-Based Total Knee Arthroplasty: A Prospective Cohort Study and Validation of a New Classification System.

BACKGROUND: The objective of this study was to compare macroscopic bone and soft tissue injury between robotic-arm assisted total knee arthroplasty (RA-TKA) and conventional jig-based total knee arthroplasty (CJ-TKA) and create a validated classification system for reporting iatrogenic bone and periarticular soft tissue injury after TKA. METHODS: This study included 30 consecutive CJ-TKAs followed by 30 consecutive RA-TKAs performed by a single surgeon. Intraoperative photographs of the femur, tibia, and periarticular soft tissues were taken before implantation of prostheses. Using these outcomes, the macroscopic soft tissue injury (MASTI) classification system was developed to grade iatrogenic bone and soft tissue injuries. Interobserver and Intraobserver validity of the proposed classification system was assessed. RESULTS: Patients undergoing RA-TKA had reduced medial soft tissue injury in both passively correctible (P < .05) and noncorrectible varus deformities (P < .05); more pristine femoral (P < .05) and tibial (P < .05) bone resection cuts; and improved MASTI scores compared to CJ-TKA (P < .05). There was high interobserver (intraclass correlation coefficient 0.92 [95% confidence interval: 0.88-0.96], P < .05) and intraobserver agreement (intraclass correlation coefficient 0.94 [95% confidence interval: 0.92-0.97], P < .05) of the proposed MASTI classification system. CONCLUSION: There is reduced bone and periarticular soft tissue injury in patients undergoing RA-TKA compared to CJ-TKA. The proposed MASTI classification system is a reproducible grading scheme for describing iatrogenic bone and soft tissue injury in TKA. CLINICAL RELEVANCE: RA-TKA is associated with reduced bone and soft tissue injury compared with conventional jig-based TKA. The proposed MASTI classification may facilitate further research correlating macroscopic soft tissue injury during TKA to long-term clinical and functional outcomes.

An Early Report of the Use of a Modular Dual Mobility Articulation in Revision Acetabular Reconstruction.

BACKGROUND: Instability remains one of the main problems after revision hip surgery. The aim of this study was to review the clinical, radiological, and patient-reported outcomes with the use of modular dual-mobility articulation for revision acetabular reconstruction and investigate the risk of fretting corrosion by measuring serum trace metal ion levels. METHODS: Sixty consecutive patients with a minimum of 24-month follow-up after the insertion of a modular dual-mobility (Stryker, Mahwah, NJ) cup at the time of revision hip surgery were identified. Follow-up included clinical and radiological patient review and functional outcome measures, and a subset of patients had their metal ion (cobalt and chromium) levels checked. RESULTS: At the most recent follow-up, 5 patients had died, 3 patients have been revised because of ongoing instability, and 3 patients have had revision surgery due to infection. Overall functional outcome (mean Western Ontario and McMaster Universities Osteoarthritis Indexfunction 76, University of California, Los Angeles 5.6, mean Oxford 74.7, Short Form-12 physical 41.6/mental 53.3) and overall pain relief (mean Western Ontario and McMaster Universities Osteoarthritis Index pain score 78.3) scores were good. The mean satisfaction score was 78 of 100. The median serum trace metal chromium and cobalt levels at the most recent follow-up were 0.4 µg/L (range 0.1-6.1 µg/L) and 0.42 µg/L (range 0.21-9.42 µg/L), respectively. The survival with revision as the end point was 90%. CONCLUSIONS: Dual-mobility cups with modularity represent an excellent option for the patient having revision hip surgery at high risk of instability. This series presents good patient-reported outcome measures and a low complication and revision rate.

What Is the Natural History of Asymptomatic Pseudotumors in Metal-on-metal THAs at Mid-term Followup?

BACKGROUND: The risk of early revision because of pseudotumors in patients who have undergone large-head metal-on-metal (MoM) total hip arthroplasty (THA) is well documented. However, the natural history of asymptomatic pseudotumors or of MoM articulations without pseudotumors is less well understood. The aim of our study was to investigate the natural history of primary MoM THA at mid-term followup. QUESTIONS/PURPOSES: The purposes of this study were: (1) Did previously detected pseudotumors persist or worsen in asymptomatic patients at mid-term followup; and if so, did any of them require revision THA? (2) Did new pseudotumors form in asymptomatic patients at mid-term followup? (3) What happened to serum trace metal ions at mid-term followup? (4) Were postoperative patient-reported outcome measures (PROMs) maintained at mid-term followup? METHODS: Seventy-one patients who underwent a MoM THA using a Metasul LDH implant with a Durom acetabular cup and an M/L Taper stem between September 2005 and October 2008 were reviewed. All patients for this study were part of two previously published studies from our early followup. Data from the previous studies were used for comparison only. Two of the 71 patients (2.8%) were lost to followup. The mean age at operation was 56 years (range, 34-68 years). There were 24 female patients. All patients had serum trace metal ions testing, ultrasound imaging, and PROMs at a mean 3.5 years (early followup) after the index operation (range, 3-5 years) and delayed followup at a mean 7 years (range, 6.5-9 years). The indication to undertake revision THA was based on clinical evaluation and not solely on the investigation results. RESULTS: Twenty-three of 71 patients (32%) had a positive ultrasound scan for pseudotumor at early followup. Of these, eight patients underwent revision THA (11% of MoM THA or 35% of patients with an early positive ultrasound scan). The mean time between positive ultrasound scan and revision surgery was 13 months (range, 5-22 months). Of the remaining 15 patients with pseudotumor noted on early ultrasound, 12 had persistent pseudotumor, two resolved, and one was lost to followup. Six patients (13%) with a normal ultrasound scan at early followup showed new ultrasound findings at delayed followup. Of these, four (8%) were conclusively diagnosed as pseudotumor and one was revised. Serum trace metal ion increased at mid-term followup in the seven cases that showed an increase in volume of pseudotumor. Of the five patients in whom the volume of pseudotumor decreased on ultrasound at mid-term followup, three showed a decrease in serum trace ions levels, whereas two showed an increase. New-onset pseudotumors at mid-term followup was associated with an increase in serum trace metal ions at mid-term followup only in two of six cases. PROMs at mid-term followup of patients in this study remain high. CONCLUSIONS: At mid-term followup, approximately 35% of patients who develop an early pseudotumor undergo revision arthroplasty, whereas the remaining are asymptomatic. The incidence of new-onset ultrasound findings suggestive of pseudotumors at mid- to long-term followup is approximately 8% and these require continued surveillance. LEVEL OF EVIDENCE: Level II, prognostic study.

The Outcomes Following Revision of Monoblock Metal on Metal Acetabular Components for Painful Micromotion in the Absence of Adverse Local Tissue Reaction to Metal.

BACKGROUND: Revision hip arthroplasty for metal-on-metal arthroplasty (MOMA) in the presence of an adverse local tissue reaction (ALTR) has been associated with compromised outcomes. We hypothesized that revision of MOMA for painful micromotion of the cup, in the absence of ALTR, would have a more favorable outcome. METHODS: We reviewed our database for Durom acetabular shell revision with minimum 24 months (24 months to 8 years) follow-up. Patients with a diagnosis of painful micromotion in the absence of pseudotumor was identified. RESULTS: At mid-term follow-up, 71 patients had undergone revision of a Durom MOMA. Twenty-seven of these (38%) were for painful micromotion (9 total hip arthroplasty, 18 hip resurfacing) of the cup alone. Following revision surgery, all patients reported resolution of the preoperative pain, as well as satisfactory outcome measures (mean scores: The Western Ontario and McMaster Universities Arthritis Index [WOMAC] 84.6, oxford hip score 84.7, Short Form Health Survey (SF-16) 51, University of California, Los Angeles (UCLA) 7.3). Radiologically, all cases demonstrated osseointegration of the revision shells; 1 case had zone-3 radiolucency that was nonprogressive. One patient had a dislocation treated by closed reduction at 10 weeks. CONCLUSION: Revision MOMA for painful micromotion of the shell in the absence of ALTR is not similar to revision for ALTR and is associated with predictable improvement in pain and quality of life.

Midterm Outcome of Avon Patellofemoral Arthroplasty for Posttraumatic Unicompartmental Osteoarthritis.

BACKGROUND: Patellofemoral arthroplasties have been successfully used in the management of isolated patellofemoral joint (PFJ) osteoarthritis (OA). We hypothesized that in posttraumatic PFJ OA, isolated unicompartmental arthroplasty should be associated with reliable pain relief, patient satisfaction, and functional outcome at midterm follow-up. METHODS: Fifty-one Avon PFJ (Stryker, Mahwah, NJ) isolated unicompartmental arthroplasties (47 patients; 29 men, 18 women) were identified at a mean follow-up of 7.1 years (range, 5-11 years). The average age at surgery was 57 years (range, 37-69 years). RESULTS: All patients reported excellent pain relief, satisfaction, and functional outcomes. Median Oxford Knee Score was 38 at latest follow-up with a significant improvement from preoperative scores (P < .0005). There were 2 revisions: 1 for pain and 1 for progression of OA. The probability for survival (Kaplan-Meyer analysis) with revision as end point was 96.1%. CONCLUSION: The study has shown good midterm results for Avon PFJ (Stryker, Mahwah, NJ) system in posttraumatic PFJ OA, at midterm follow-up in a relatively young patient cohort.

Fusion of the First Metatarsophalangeal Joint: Precontoured or Straight Plate?

Precontoured, low-profile plates with fixed dorsiflexion angles are becoming increasingly popular for first metatarsophalangeal joint fusion. We have concerns that the routine use of a precontoured plate can lead to excessive clinical dorsiflexion. The aim of our study was to investigate the relationship between the first metatarsophalangeal joint dorsiflexion intramedullary angle and the angle formed at the dorsal cortices where the plate is applied. We hypothesized that the dorsal cortical angle was significantly less dorsiflexed than the intramedullary angle. We measured both angles on lateral weightbearing radiographs of 40 consecutive individuals presenting with forefoot symptoms. The results demonstrated that the mean dorsal cortical angle was significantly smaller (mean 0.2° plantarflexion) compared with the intramedullary angle (mean 10.6° dorsiflexion; p < .001). The interobserver and intraobserver reliability of both the intramedullary and the dorsal cortical measurements was very good. In conclusion, the dorsal cortical angle is, on average, 10.8° smaller than the intramedullary angle, with a mean angle of almost 0°. This finding should be considered when selecting plates for first metatarsophalangeal joint fusion.

The Role of Dual-mobility Cups in Total Hip Arthroplasty.

It is often challenging to address instability risks when dealing with complex primary total hip arthroplasty and revision hip surgery. The implant-related options available to surgeons to deal with the risks of instability include femoral head size, femoral neck length/offset, component orientation, and the use of constrained articulations. Dual-mobility articulations have long been used in Europe in the setting of a potential or proven unstable hip; this type of articulation is now available in North America after regulatory approval. However, a dual-mobility articulation has its own unique advantages and disadvantages. Before choosing this implant option, the arthroplasty surgeon needs to be fully informed of the design concept, the surgical technique, the advantages, the disadvantages, and the literature surrounding the use of a dual-mobility articulation.

Single-Stage Hip and Knee Exchange for Periprosthetic Joint Infection.

Periprosthetic joint infections following hip and knee arthroplasty are challenging complications for Orthopaedic surgeons to manage. The single-stage exchange procedure is becoming increasingly popular with promising results. At our Institute we have demonstrated favourable or similar outcomes compared to the 'gold-standard' two-stage exchange, and other published single-stage results. The aim of this study is to describe the patient selection criteria and perioperative steps in a single-stage exchange for hip and knee arthroplasty undertaken at our Institute. The outlined protocol can be performed using standard debridement, attention to detail and well-recognised reconstructive techniques.

Patients' expectations surrounding revision total hip arthroplasty: a literature review.

BACKGROUND: Revision total hip arthroplasties (RTHA) are associated with a higher complication rate than primary total hip arthroplasties (THA), and therefore it is important for patients to have realistic expectations regarding outcomes. The aim of this literature review was to gather and summarize the available evidence on patients' expectations following RTHA. METHODS: A literature search was conducted in PubMed, PsycINFO, Cochrane, Google Scholar, Web of Science and Embase from inception to November 2023. Articles assessing patient expectations for RTHA were included. Methodological quality was assessed by two independent reviewers using the National Heart, Lung and Blood Institute (NIH) study quality assessment tool for observational cohort and cross-sectional studies. A qualitative analysis was performed involving the summarization of study characteristics and outcomes. RESULTS: The search strategy generated 7,450 references, of which 5 articles met the inclusion criteria. Methodological quality scores ranged from 7-10. Patients had high expectations concerning future walking ability, pain and implant longevity relative to actual postoperative outcomes. A significant positive correlation was found between fulfilled expectations of pain and walking ability and patient satisfaction (r = 0.46-0.47). Only two studies assessed the fulfillment of patient expectations. Great variability was seen in the measurement of expectations. CONCLUSION: Patients undergoing RTHA appeared to have high expectations for pain and functionality compared to postoperative outcomes. However, there was a paucity of high-quality data in this area, limiting the accuracy of the conclusion. Further research is needed, that emphasizes developing a sound theoretical framework for expectations, allowing for the consistent implementation of valid measurement tools for patient expectations.

A prospective randomized controlled trial comparing CT-based planning with conventional total hip arthroplasty versus robotic arm-assisted total hip arthroplasty.

Aims: Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA. Methods: This prospective randomized controlled trial (RCT) included 60 patients with symptomatic hip osteoarthritis undergoing conventional THA (CO THA) versus robotic arm-assisted THA (RO THA). Patients in both arms underwent pre- and postoperative CT scans, and a patient-specific plan was created using the robotic software. The COR, combined offset, acetabular orientation, and leg length discrepancy were measured on the pre- and postoperative CT scanogram at six weeks following surgery. Results: There were no significant differences for any of the baseline characteristics including spinopelvic mobility. The absolute error for achieving the planned horizontal COR was median 1.4 mm (interquartile range (IQR) 0.87 to 3.42) in RO THA versus 4.3 mm (IQR 3 to 6.8; p < 0.001); vertical COR mean 0.91 mm (SD 0.73) in RO THA versus 2.3 mm (SD 1.3; p < 0.001); and combined offset median 2 mm (IQR 0.97 to 5.45) in RO THA versus 3.9 mm (IQR 2 to 7.9; p = 0.019). Improved accuracy was observed with RO THA in achieving the desired acetabular component positioning (root mean square error for anteversion and inclination was 2.6 and 1.3 vs 8.9 and 5.3, repectively) and leg length (mean 0.6 mm vs 1.4 mm; p < 0.001). Patient-reported outcome measures were comparable between the two groups at baseline and one year. Participants in the RO THA group needed fewer physiotherapy sessions postoperatively (median six (IQR 4.5 to 8) vs eight (IQR 6 to 11; p = 0.005). Conclusion: This RCT suggested that robotic-arm assistance in THA was associated with improved accuracy in restoring the native COR, better preservation of the combined offset, leg length correction, and superior accuracy in achieving the desired acetabular component positioning. Further evaluation through long-term and registry data is necessary to assess whether these findings translate into improved implant survival and functional outcomes.

Successful fixation of an intertrochanteric fracture after hip resurfacing arthroplasty using cannulated screws.

We report a case of successful treatment of a high, stable intertrochanteric fracture (type 1) in a 59-year-old man. He sustained the injury 8 years after the resurfacing procedure. The fracture was fixed using three 6.5-mm cannulated screws, and he has returned to his normal level of activities 8 months after the fixation. We have shown that fixation with cannulated screws may be an acceptable option for treatment of high trochanteric fractures where a stable anatomical reduction can be obtained. We have also included a review of the literature for other reported surgical treatment options of this complication.

Bone loss during revision of unicompartmental to total knee arthroplasty: an analysis of implanted polyethylene thickness from the National Joint Registry data.

Using the National Joint Registry (UK) database, we compared the thickness of polyethylene (PE) and the level of constraint used during primary total knee arthroplasty (TKA) versus the revision of unicondylar knee arthroplasty (UKA) to TKA. A total of 251,803 TKA procedures and 374 revision UKA-TKA procedures between 2003 and 2009 were reviewed. The commonest PE size used in TKA was 10mm, compared to 12.79 mm in the revision group. The use of constrained knee implant was required in 2.15% of primary TKA and 4.19% of UKA to TKA revisions. The revision of UKA to TKA is a more complex procedure compared to primary TKA, with a higher incidence of using constrained implants and thicker PE inserts. These findings may be useful for surgeons in their decision making.