Background and purposeThe clinical findings of adverse reaction to metal debris (ARMD) following large-diameter-head metal-on-metal total hip arthroplasty (LDH MoM THA) may include periarticular fluid collections, soft tissue masses, and gluteal muscle necrosis. The ReCap-M2a-Magnum LDH MoM THA was the most commonly used hip device at our institution from 2005 to 2012. We assessed the prevalence of and risk factors for ARMD with this device.Methods74 patients (80 hips) had a ReCap-M2a-Magnum LDH MoM THA during the period August 2005 to December 2006. These patients were studied with hip MRI, serum chromium and cobalt ion measurements, the Oxford hip score questionnaire, and by clinical examination. The prevalence of ARMD was recorded and risk factors for ARMD were assessed using logistic regression models. The mean follow-up time was 6.0 (5.5–6.7) years.ResultsA revision operation due to ARMD was needed by 3 of 74 patients (3 of 80 hips). 8 additional patients (8 hips) had definite ARMD, but revision was not performed. 29 patients (32 hips) were considered to have a probable or possible ARMD. Altogether, 43 of 80 hips had a definite, probable, or possible ARMD and 34 patients (37 hips) were considered not to have ARMD. In 46 of 78 hips, MRI revealed a soft tissue mass or a collection of fluid (of any size). The symptoms clicking in the hip, local hip swelling, and a feeling of subluxation were associated with ARMD.InterpretationARMD is common after ReCap-M2a-Magnum total hip arthroplasty, and we discourage the use of this device. Asymptomatic patients with a small fluid collection on MRI may not need instant revision surgery but must be followed up closely.

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Background: Femoroacetabular impingement (FAI) is a condition known to cause hip pain in young adults. Purpose: To evaluate the efficacy of the surgical correction of FAI via arthroscopic osteochondroplasty with or without labral repair compared with arthroscopic lavage of the hip joint with or without labral repair. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 220 male and female participants aged 18 to 50 years with nonarthritic FAI suitable for surgical treatment were recruited for the trial at 10 clinical centers in Canada, Finland, and Denmark between October 2012 and November 2017, of whom 214 were included in the final analysis. In the osteochondroplasty group, cam- and/or pincer-type lesions were resected using fluoroscopic guidance. In the lavage group, the joint was washed out with 3 L of normal saline. Surgeons were instructed to repair the labrum in both groups if it was mechanically unstable once probed, showing visible displacement or chondrolabral separation. The primary outcome was patient-reported pain (using the 100-point visual analog scale [VAS]) at 12 months. Secondary outcomes included hip function (Hip Outcome Score [HOS] and International Hip Outcome Tool), physical and mental health (12-Item Short Form Health Survey), and health utility (EuroQol–5 Dimensions) at 12 months as well as any reoperations and other hip-related adverse events at 24 months. Results: At 12 months, there was no difference in pain (VAS) between the groups (mean difference [MD], 0.11 [95% CI, –7.22 to 7.45]; P = .98). Also, 88.3% (189/214) of participants had a labral tear, of which 60.3% were repaired. For the secondary outcomes, there were no significant differences between treatment groups, with the exception of the HOS activities of daily living domain in which lavage showed significant improvement compared with osteochondroplasty (MD, –5.03 [95% CI, −10.40 to −0.03]; P = .049). By 24 months, there were significantly fewer reoperations reported in the osteochondroplasty group (8/105) than the lavage group (19/104) (odds ratio, 0.37 [95% CI, 0.15-0.89]; P = .026). The primary reasons for a reoperation included hip pain (15/27; 55.6%) and a reinjury of the labrum (11/27; 40.7%). Conclusion: Both the osteochondroplasty and the lavage groups with or without labral repair for FAI had significantly improved pain or function significantly at 1 year. By 2 years, the reoperation rate was significantly lower in the osteochondroplasty group. Registration: NCT01623843 ( ClinicalTrials.gov identifier)

Background and purposePopulation-based registry data from the Nordic Arthroplasty Register Association (NARA) and from the National Joint Register of England and Wales have revealed that the outcome after hip resurfacing arthroplasty (HRA) is inferior to that of conventional total hip arthroplasty (THA). We analyzed the short-term survival of 4,401 HRAs in the Finnish Arthroplasty Register.MethodsWe compared the revision risk of the 4,401 HRAs from the Register to that of 48,409 THAs performed during the same time period. The median follow-up time was 3.5 (0–9) years for HRAs and 3.9 (0–9) years for THAs.ResultsThere was no statistically significant difference in revision risk between HRAs and THAs (RR = 0.93, 95% CI: 0.78–1.10). Female patients had about double the revision risk of male patients (RR = 2.0, CI: 1.4–2.7). Hospitals that had performed 100 or more HRA procedures had a lower revision risk than those with less than 100 HRAs (RR = 0.6, CI: 0.4–0.9). Articular Surface Replacement (ASR, DePuy) had inferior outcome with higher revision risk than the Birmingham Hip Resurfacing implant (BHR, Smith & Nephew), the reference implant (RR = 1.8, CI: 1.2–2.7).InterpretationWe found that HRA had comparable short-term survivorship to THA at a nationwide level. Implant design had an influence on revision rates. ASR had higher revision risk. Low hospital procedure volume worsened the outcome of HRA. Female patients had twice the revision risk of male patients.

Level III, therapeutic study.

Background and purposeThe role of pelvic incidence in hip disorders is unclear. Therefore, we undertook a literature review to evaluate the evidence on that role.MethodsA search was carried out on MEDLINE, SCOPUS, CENTRAL, and CINAHL databases. Quantitative analysis was based on comparison with a reference population of asymptomatic subjects.ResultsThe search resulted in 326 records: 15 studies were analyzed qualitatively and 13 quantitatively. The estimates of pelvic incidence varied more than 10 degrees from 47 (SD 3.7) to 59 (SD 14). 2 studies concluded that higher pelvic incidence might contribute to the development of coxarthrosis while 1 study reported the opposite findings. In 2 studies, lower pelvic incidence was associated with a mixed type of femoroacetabular impingement. We formed a reference population from asymptomatic groups used or cited in the selected studies. The reference comprised 777 persons with pooled average pelvic incidence of 53 (SD 10) degrees. The estimate showed a relatively narrow 95% CI of 52 to 54 degrees. The 95% CIs of only 4 studies did not overlap the CIs of reference: 2 studies on coxarthrosis, 1 on mixed femoroacetabular impingement, and 1 on ankylosing spondylitisInterpretationWe found no strong evidence that pelvic incidence plays any substantial role in hip disorders. Lower pelvic incidence may be associated with the mixed type of femoroacetabular impingement and hip problems amongst patients with ankylosing spondylitis. The evidence on association between pelvic incidence and coxarthrosis remained inconclusive.

. Purpose:  To analyse the accuracy of corneal flap thickness created in laser‐assisted in situ keratomileusis (LASIK) using the Moria Model 2 (M2) single‐use head 90 microkeratome. Methods:  The corneal thickness of 300 (266 myopic and 34 hyperopic) eyes of 150 patients was measured by ultrasonic pachymetry preoperationally and intraoperationally after flap cut. The Moria M2 single‐use head 90, intended to create a flap with a thickness of 120 µm, was used in all eyes. The right eye was always operated first and the left eye second, using the same blade. Results:  Mean corneal flap thickness was 115.4 µm (standard deviation [SD] 12.5) in the two eyes, 115.7 µm (SD 12.4, range 73–147 µm) in right eyes and 115.1 µm (SD 12.6, range 74–144 µm) in left eyes. Mean horizontal flap diameter was 9.1 mm (SD 0.2) and mean hinge length 4.1 mm (SD 0.1). There were no free flaps, incomplete flaps or flaps with buttonholes in the study. Occasional iron particles were observed in three (1.0%) eyes. Conclusions:  As with most microkeratomes, the single‐use head 90 microkeratome cut thinner flaps than were intended. The range of the cuts was relatively wide. However, thin flaps did not increase the rate of flap‐related complications. The difference between the first and second eyes was not significant.

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