Did the dislocation risk after primary total hip arthroplasty decrease over time? A meta-analysis across six decades.

BACKGROUND: While continuous optimization is attempted to decrease the incidence of dislocation after total hip arthroplasty (THA), dislocation remains a major complication. This meta-analysis aims to analyze the evolution of the dislocation risk after primary THA over the decades and to evaluate its potential publication bias. PATIENTS AND METHODS: A systematic search was performed according to the PRISMA guidelines for this meta-analysis in the literature published between 1962 and 2020. MEDLINE, Cochrane and Embase databases were searched for studies reporting the dislocation risk and length of follow-up. Studies that reported on revision rates only and did not mention separate dislocations were excluded. All study designs were eligible. Study quality was assessed by existing quality assessment tools adjusted for arthroplasty research. Overall risk and yearly dislocation rates were calculated and related to historical time frame, study design, sample size and length of follow-up. RESULTS: In total, 174 studies were included with an overall moderate quality. In total there were 85.209 dislocations reported in 5.030.293 THAs, showing an overall dislocation risk of 1.7%, with a median follow-up of 24 months. The overall dislocation risk classified per decade decreased from 3.7% in 1960-1970 to 0.7% in 2010-2020. The yearly dislocation rate decreased from 1.8 to 0.7% within these same decades. There was no significant correlation between the reported dislocation risk and the duration of follow-up (p = 0.903) or sample size (p = 0.755). The reported dislocation risk was higher in articles with registry data compared to other study designs (p = 0.021). CONCLUSION: The dislocation risk in THA has been decreasing over the past decades to 0.7%. Non-selective registry studies reported a higher dislocation risk compared to studies with selective cohorts and RCTs. This indicates that the actual dislocation risk is higher than often reported and 'real-world data' are reflected better in large-scale cohorts and registries.

Concomitant ankle instability has a negative impact on the quality of life in patients with osteochondral lesions of the talus: data from the German Cartilage Registry (KnorpelRegister DGOU).

PURPOSE: The purpose of this study was to compare patients with osteochondral lesions of the talus (OCLT) with and without concomitant chronic ankle instability (CAI). METHODS: Data from the German Cartilage Registry (KnorpelRegister DGOU) for 63 patients with a solitary OCLT were used. All patients received autologous matrix-induced chondrogenesis (AMIC) for OCLT treatment. Patients in group A received an additional ankle stabilisation, while patients in group B received AMIC alone. Both groups were compared according to demographic, lesion-related, and therapy-related factors as well as baseline clinical outcome scores at the time of surgery. The Foot and Ankle Ability Measure (FAAM), the Foot and Ankle Outcome Score (FAOS), and the Numeric Rating Scale for Pain (NRS) were used. RESULTS: Patients in group A were older compared to group B [median 34 years (range 20-65 years) vs. 28.5 years (range 18-72 years)]; the rate of trauma-associated OCLTs was higher (89.7% vs. 38.3%); more patients in group A had a previous non-surgical treatment (74.1% vs. 41.4%); and their OCLT lesion size was smaller [median 100 mm2 (range 15-600 mm2) vs. 150 mm2 (range 25-448 mm2)]. Most OCLTs were located medially in the coronary plane and centrally in the sagittal plane in both groups. Patients in group A had worse scores on the FAOS quality-of-life subscale compared to patients in group B. CONCLUSION: Patients with OCLT with concomitant CAI differ from those without concomitant CAI according to demographic and lesion-related factors. The additional presence of CAI worsens the quality of life of patients with OCLT. Patients with OCLT should be examined for concomitant CAI, so that if CAI is present, it can be integrated into the treatment concept. LEVEL OF EVIDENCE: IV.