No difference in the use of revision components and rerevision rate in conversion to total knee replacement following Oxford Partial Knee Microplasty Instrumentation: a registry study of 529 conversions.

BACKGROUND AND PURPOSE: Microplasty Instrumentation was introduced to improve Oxford Mobile Partial Knee placement and preserve tibial bone in partial knee replacement (PKR). This might therefore reduce revision complexity. We aimed to assess the difference in use of revision total knee replacement (TKR) tibial components in failed Microplasty versus non-Microplasty instrumented PKRs. PATIENTS AND METHODS: Data on 529 conversions to TKR (156 Microplasty instrumented and 373 non-Microplasty instrumented PKRs) from the Dutch Arthroplasty Register (LROI) between 2007 and 2019 was used. The primary outcome was the difference in use of revision TKR tibial components during conversion to TKR, which was calculated with a univariable logistic regression analysis. The secondary outcomes were the 3-year re-revision rate and hazard ratios calculated with Kaplan-Meier and Cox regression analyses. RESULTS: Revision TKR tibial components were used in 29% of the conversions to TKR after failed Microplasty instrumented PKRs and in 24% after failed non-Microplasty instrumented PKRs with an odds ratio of 1.3 (CI 0.86-2.0). The 3-year re-revision rates were 8.4% (CI 4.1-17) after conversion to TKR for failed Microplasty and 11% (CI 7.8-15) for failed non-Microplasty instrumented PKRs with a hazard ratio of 0.77 (CI 0.36-1.7). CONCLUSION: There was no difference in use of revision tibial components for conversion to TKR or in re-revision rate after failed Microplasty versus non-Microplasty instrumented PKRs nor in the 3-year revision rate.

Acute femoral fracture does not compromise the outcome of total hip arthroplasty : 5 year results from a single center cohort study in 2,782 patients.

National arthroplasty registries reveal a higher risk of revision for periprosthetic fracture and dislocation after total hip arthroplasty (THA) in patients with a femoral neck fracture compared to those with osteoarthritis (OA). Since these registries may con- tain confounding factors, we conducted a single center cohort study comparing survival and reason for failure between THA for an acute femoral neck fracture and OA using the same hip prosthesis after a minimum follow-up of 2 years. We retrospectively analyzed 2782 patients who had undergone THA with an Accolade TMZF stem and a Trident cup between March 2009 and September 2014. Primary diagnosis before THA was osteoarthritis (OA group : n=2610) or acute femoral fracture (Fracture group : n=172). Patients in both groups were operated on by the same hip surgeons. Effect of diagnosis on THA survival was analyzed using Cox-regression analysis. Chi-square tests were used to illustrate the different reasons for revision between the groups. Mean follow-up was 4.6 years (2-7.6). A total of 100 revisions were performed. The revision risk was comparable between the OA and Fracture group (HR=1.04, 95% CI :0.46-2.39). No differences were found between the OA and Fracture group with respect to the occurrence of periprosthetic fractures (0.8% vs. 0.6%, p=0.71) and revisions for dislocation (0.6% vs. 1.2%, p=0.38). We found no difference in outcome or reason for revision between THA for OA or femoral neck frac- ture. Using an implant with a proven ODEP rating and having experienced hip surgeons carry out the procedures may be more important than the primary diagnosis.

No Learning Curve of the Direct Superior Approach in Total Hip Arthroplasty.

OBJECTIVES: To assess the learning curve of the direct superior approach (DSA) for total hip arthroplasty (THA) and to compare surgical, clinical, and radiological results with a matched control group using the mini posterior approach (MPA). METHODS: A prospective cohort study was performed from October 2016 to May 2017 including our first 52 patients undergoing THA using the DSA. Patients with primary osteoarthritis or osteonecrosis and a body mass index (BMI) < 35 who were eligible for surgery were included. As a control group, 52 patients who underwent the MPA were included, matched based on age, BMI, and ASA classification. In the DSA group, damage to the iliotibial tract and the distal external rotators, including the external obturator and quadriceps femoris muscles, was avoided. Outcome measures were collected, including surgical time, blood loss, postoperative pain, length of stay, implant position, use of walking aids, patient reported outcome measures (PROM), and complications. Unpaired t-tests were used to analyze differences between the DSA and the MPA group in surgical time, blood loss, length of stay, and acetabular and femoral component position. χ2 -tests were used to analyze mobility and the number of complications. Two-way repeated measures ANOVA was used to analyze pain scores and PROM between the DSA and the MPA groups. RESULTS: The mean surgical time of 61 min (SD 8) in the DSA group was longer (P < 0.001) compared to that in the MPA group, 46 min (SD 12). No differences were found in blood loss, postoperative pain, or mean length of stay in the hospital. After 6 weeks, 94% of the patients in the DSA group were able to walk inside their home without walking aids compared to 90% in the MPA group. The mobility scores were not different after follow up of 6 weeks and 1 year (P = 0.12 and P = 0.36 respectively). All PROM improved postoperatively in both the DSA and the MPA group (P < 0.01). Acetabular cup and femoral stem position were not compromised by the DSA. Complications included two Vancouver B2 periprosthetic fractures in the DSA group, of which there was one surgical-related fracture and one fracture after a traffic accident. Complications in the MPA group included one periprosthetic fracture, two hip dislocations, and one ischial neuropathy. No infections or thromboembolic events were observed. The 1-year complication rate was not different between the MPA and DSA groups (P = 0.40). CONCLUSION: The DSA can be safely introduced as no learning curve in the prosthesis position or the complication rate was found.

[The limping child: a red flag for every physician]. / Het mankend kind: een rode vlag voor iedere medicus.

A limping gait pattern in a child is a red flag for every physician until proven otherwise. Among the most common causes are coxitis fugax, infection (septic arthritis, osteomyelitis), Perthes disease, and slipped capital femoral epiphysis, depending on the age of the patient. A high index of suspicion is required because clinical findings are often subtle, and the diagnosis may be present even if initial radiographs are negative. A missed or delayed diagnosis may have devastating consequences. Therefore, this paper describes the main characteristics of different causes of a limping child, based on four typical cases. Tools are provided to recognize each diagnosis. Early referral to a paediatric orthopaedic surgeon is recommended.

Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases.

INTRODUCTION: Surgeon volume of hip arthroplasties is of importance with regard to complication and revision rates in total hip arthroplasty. For hip hemiarthroplasty, the effect of surgeon volume on outcome is far less studied. We analyzed the outcome of hip hemiarthroplasties performed by orthopedic surgeons in a retrospective cohort in different volume categories, focusing on early survival of the prosthesis and complications. METHODS: Between March 2009 and January 2014, 752 hemiarthroplasties were performed for intracapsular femoral neck fracture by 27 orthopedic surgeons in a large Dutch teaching hospital. Surgeons were divided into four groups, a resident group and three groups based on the number of total hip arthroplasties and hemiarthroplasties performed per year: a low-volume (< 10 arthroplasties per year), moderate-volume (10-35 arthroplasties per year), and high-volume groups (> 35 arthroplasties per year). Outcome measures were stem survival using a competing risk analysis, complication rates, and mortality. Chi-square tests were used to compare complication rates and mortality between groups. RESULTS: Patients were followed for a minimum of 2 years or until revision or death. Overall 60% of the patients included had died at time of follow-up. We found comparable stem survival rates in the low-volume group (n = 48), moderate-volume group (n = 201), high-volume group (n = 446), and resident group (n = 57). There were no significant differences between the groups with regard to dislocation rate, incidence of periprosthetic fracture, infection, and mortality. CONCLUSION: Surgeon volume and experience did not influence early outcome and complication rates in hip hemiarthroplasty. Hemiarthroplasty can safely be performed by both experienced hip surgeons and low-volume surgeons.

Midterm survival analysis of a cemented dual-mobility cup combined with bone impaction grafting in 102 revision hip arthroplasties.

INTRODUCTION: Revision hip arthroplasty is associated with higher dislocation rates than primary hip arthroplasty. A dual-mobility cup (DMC) can reduce this risk. Another problem is destruction of the acetabulum, induced by aseptic loosening of the prosthesis. Bone impaction grafting (BIG) can be used to reconstruct these defects, but is usually performed with cemented all polyethylene cups. The purpose of this study is to evaluate midterm cup survival and dislocation rate for the combination of BIG and DMC. METHODS: Between 2007 and 2013, 96 patients received 102 DMCs combined with BIG of the acetabulum during revision surgery. These data were first compared with a control group, consisting of 59 cases from the same hospital receiving a cemented all polyethylene cup combined with BIG. In addition, the control group was expanded with 41 cases operated on in 2007 in 'an orthopaedic centre of excellence', resulting in a 'combined control group' of 100 patients. Log-rank tests and chi-square tests were used to compare survival and dislocation rates, respectively. RESULTS: Cumulative survival of the DMC was 95.8% (range 3 months-7 years). This was comparable to the survival in the control groups (96.5% and 94.7%). The dislocation rate of 2.9% (3/102) in the dual-mobility group was lower (p = 0.02) compared to the dislocation rate of 11.8% (7/59) in the control group, but not (p = 0.12) compared to 8% in the combined control group (8/100). CONCLUSIONS: This study shows that combining a DMC with BIG does not compromise outcome in terms of midterm survival of the cup.

The result of transmuscular versus transosseous repair of the posterior capsule on early dislocations in primary hip arthroplasty.

PURPOSE: Dislocation is a concerning complication of the posterolateral approach for total hip arthroplasty (THA). Use of a larger size femoral head and a correct repair of the posterior structures can reduce the risk on dislocation of the hip prosthesis. In this study we investigated if there was a difference in dislocation rate between transmuscular and transosseous repair of the posterior soft tissues with use of 36 mm heads. METHODS: A power analysis showed that with a standardised effect size of 0.3 and p-value of 0.05, each group should include at least 174 patients. A total of 465 consecutive primary THAs with a posterolateral approach were performed in patients with primary osteoarthritis by 3 orthopaedic surgeons. There were 246 patients operated using transmuscular repair, the other 219 by using transosseous repair. All patients were given the same prostheses. RESULTS: Dislocation rate was 1.7% in all patients with at least 1 year follow-up. No significant difference was found in dislocation between both reconstruction techniques. Clinical outcome scores were comparable between the groups. CONCLUSIONS: Transosseous and transmuscular repair were equally effective techniques in closing the posterior soft tissues after THA through the posterolateral approach, without difference in dislocation rate or complication rate.

High complication rate in the early experience of minimally invasive total hip arthroplasty by the direct anterior approach.

BACKGROUND AND PURPOSE: There is growing interest in minimally invasive surgery techniques in total hip arthroplasty (THA). In this study, we investigated the learning curve and the early complications of the direct anterior approach in hip replacement. METHODS: In the period January through December 2010, THA was performed in 46 patients for primary osteoarthritis, using the direct anterior approach. These cases were compared to a matched cohort of 46 patients who were operated on with a conventional posterolateral approach. All patients were followed for at least 1 year. RESULTS: Operating time was almost twice as long and mean blood loss was almost twice as much in the group with anterior approach. No learning effect was observed in this group regarding operating time or blood loss. Radiographic evaluation showed adequate placement of the implants in both groups. The early complication rate was higher in the anterior approach group. Mean time of hospital stay and functional outcome (with Harris hip score and Oxford hip score) were similar in both groups at the 1-year follow-up. INTERPRETATION: The direct anterior approach is a difficult technique, but adequate hip placement was achieved radiographically. Early results showed no improvement in functional outcome compared to the posterolateral approach, but there was a higher early complication rate. We did not observe any learning effect after 46 patients.