Effect of femoral stem surface coating on clinical and radiographic outcomes of cementless primary total hip arthroplasty: a patient-matched retrospective study.

PURPOSE: This study aims to determine whether changing the stem coating grants superior outcomes at a minimum follow-up of five years. METHODS: Retrospective review of a consecutive series of primary total hip arthroplasties (THAs) operated by direct anterior approach between 01/01/2013 and 31/12/2014. Two stems were compared, which were identical except for their surface coating; "the Original stem" was fully coated with hydroxyapatite (HA), while "the ProxCoat stem" was proximally coated with plasma-sprayed titanium and HA. Matching was performed. Clinical assessment included modified Harris hip score (mHHS), Oxford hip score (OHS), and forgotten joint score (FJS). Radiographic assessment evaluated alignment, subsidence, pedestal formation, heterotopic ossification, radiolucent lines ≥ 2 mm, spot welds, cortical hypertrophy, and osteolysis. RESULTS: 232 hips received the Original stem and 167 the ProxCoat stem, from which respectively five hips (2.2%) and no hips (0%) underwent revision. Matching identified two groups of 91 patients, with comparable patient demographics. At > five years follow-up, there were no differences in OHS (16 ± 6 vs 15 ± 5; p = 0.075) nor FJS (81 ± 26 vs 84 ± 22; p = 0.521), but there were differences in mHHS (89 ± 15 vs 92 ± 12; p = 0.042). There were no differences in alignment, subsidence, pedestal formation, heterotopic ossification, cortical hypertrophy, and osteolysis. There were differences in prevalence of proximal radiolucent lines (12% vs 0%; p < 0.001) and distal spot welds (24% vs 54%; p < 0.001). CONCLUSION: At a minimum follow-up of five years, this study on matched patients undergoing primary THA found that ProxCoat stems results in significantly fewer radiolucent lines, more spot welds, and less revisions than Original stems, thus suggesting better bone ingrowth.

Satisfactory clinical and radiographic outcomes following revision total hip arthroplasty by direct anterior approach using primary femoral stems at 2-8 years of follow-up.

INTRODUCTION: To report clinical and radiographic outcomes of revision total hip arthroplasty (THA) through the direct anterior approach (DAA) using primary stems. MATERIALS AND METHODS: The authors assessed a consecutive series of revision THAs operated by DAA using primary (cemented and uncemented) stems between 1/1/2010 and 30/06/2017. The initial cohort comprised 47 patients (50 hips), aged 65 ± 10 years with BMI of 25 ± 4 kg/m2. Clinical assessment included modified Harris Hip Score (mHHS) and satisfaction with surgery. Radiographic assessment included radiolucent lines > 2 mm, bone remodelling, cortical hypertrophy, pedestal formation, and osteolysis. Linear regression analyses were performed. RESULTS: Of the 50 hips (47 patients) in the initial cohort, intraoperative complications that did not require re-revision occurred in 5 hips. At a follow-up of > 2 years: 5 hips (10%) were lost to follow-up and 3 hips (6%) required stem re-revision, leaving a final cohort of 42 hips (40 patients). Postoperative complications that did not require re-revision occurred in 4 hips (8%). At 4.3 ± 1.6 years, post-revision mHHS was 89 ± 14 (range 47-100) and 38 patients were satisfied or very satisfied with revision surgery. Bone remodelling was observed in 8 hips (16%), cortical hypertrophy in 6 hips (12%), grade I heterotopic ossification in 7 hips (14%), and grade II in 1 hip (2%). There were no cases of radiolucent lines, pedestal formation, or osteolysis. Regression analyses revealed that post-revision mHHS was not associated with any variable. CONCLUSIONS: Revision THA performed through the DAA using primary stems grants satisfactory clinical and radiographic outcomes at a minimum follow-up of two years.

Criteria for the Operating Room Confirmation of the Diagnosis of Hip Instability: The Results of an International Expert Consensus Conference.

PURPOSE: The purpose of this study was to establish an international expert consensus on operating room findings that aid in the diagnosis of hip instability. METHODS: An expert panel was convened to build an international consensus on the operating room diagnosis/confirmation of hip instability. Seventeen surgeons who have published or lectured nationally or internationally on the topic of hip instability were invited to participate. Fifteen panel members completed a pre-meeting questionnaire and agreed to participate in a 1-day consensus meeting on May 15, 2021. A review of the literature was performed to identify published intraoperative reference criteria used in the diagnosis of hip instability. Studies were included for discussion if they reported and intraoperative findings associated with hip instability. The evidence for and against each criteria was discussed, followed by an anonymous voting process. For consensus, defined a priori, items were included in the final criteria set if at least 80% of experts agreed. RESULTS: A review of the published literature identified 11 operating room criteria that have been used to facilitate the diagnosis of hip instability. Six additional criteria were proposed by panel members as part of the pre-meeting questionnaire. Consensus agreement was achieved for 8 criteria, namely ease of hip distraction under anesthesia (100.0% agreement), inside-out pattern of chondral damage (100.0% agreement), location of chondral damage on the acetabulum (93.3% agreement), pattern of labral damage (93.3% agreement), anteroinferior labrum chondral damage (86.7% agreement), perifoveal cartilage damage (97.6% agreement), a capsular defect (86.7% agreement), and capsular status (80.0% agreement). Consensus was not achieved for 9 items, namely ligamentum teres tear (66.7% agreement), arthroscopic stability tests (46.7% agreement), persistent distraction after removal of traction (46.7% agreement), findings of examination under anesthesia (46.7% agreement), the femoral head divot sign (40.0% agreement), inferomedial synovitis (26.7% agreement), drive-through sign (26.7% agreement), iliopsoas irritation (26.7% agreement) and ligamentum teres-labral kissing lesion (13.3% agreement). All experts agreed on the final list of 8 criteria items reaching consensus. CONCLUSION: This expert panel identified 8 criteria that can be used in the operating room to help confirm the diagnosis of hip instability. LEVEL OF EVIDENCE: Level V expert opinion.

Does Cup Position at the High Hip Center or Anatomic Hip Center in THA for Developmental Dysplasia of the Hip Result in Better Harris Hip Scores and Revision Incidence? A Systematic Review.

BACKGROUND: One goal of THA is to restore the anatomic hip center, which can be achieved in hips with developmental dysplasia by placing cups at the level of the native acetabulum. However, this might require adjuvant procedures such as femoral shortening osteotomy. Another option is to place the cup at the high hip center, potentially reducing surgical complexity. Currently, no clear consensus exists regarding which of these cup positions might offer better functional outcomes or long-term survival. QUESTION/PURPOSE: We performed a systematic review to determine whether (1) functional outcomes as measured by the Harris hip score, (2) revision incidence, and (3) complications that do not result in revision differ based on the position of the acetabular cup (high hip center versus anatomic hip center) in patients undergoing THA for developmental dysplasia of the hip (DDH). METHODS: We performed a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, including studies comparing the functional outcomes, revision incidence, and complications of primary THA in dysplastic hips with acetabular cups placed at the high hip center versus those placed at the anatomic hip center, over any time frame. The review protocol was registered with PROSPERO (registration number CRD42020168183) before commencement. Of 238 records, eight comparative, retrospective nonrandomized studies of interventions were eligible for our systematic review, reporting on 207 hips with cups placed at the high hip center and 268 hips with cups at the anatomic hip center. Risk of bias within eligible studies was assessed using the Risk Of Bias In Non-randomized Studies of Interventions tool. Due to low comparability between studies, data could not be pooled, so these studies were assessed without summary effects. RESULTS: Six studies compared Harris hip scores, two of which favored high hip center cup placement and three of which favored anatomic hip center cup placement, although none of the differences between cohorts met the minimum clinically important difference. Five studies reliably compared revision incidence, which ranged from 2% to 9% for high hip center at 7 to 15 years and 0% to 5.9% for anatomic hip center at 6 to 16 years. Five studies reported intra- and postoperative complications, with the high hip center being associated with higher incidence of dislocation and lower incidence of neurological complications. No clear difference was observed in intraoperative complications between the high hip center and anatomic hip center. CONCLUSION: No obvious differences could be observed in Harris hip score or revision incidence after THA for osteoarthritis secondary to DDH between cups placed at the anatomic hip center and those placed at the high hip center. Placement of the acetabular cup in the high hip center may lead to higher risk of dislocation but lower risk of neurologic complications, although no difference in intraoperative complications was observed. Surgeons should be able to achieve satisfactory functional scores and revision incidence using either technique, although they should be aware of how their choice influences hip biomechanics and the need for adjunct procedures and associated risks and operative time. These recommendations should be considered with respect to the several limitations in the studies reviewed, including the presence of serious confounding factors and selection biases, inconsistent definitions of the high hip center, variations in dysplasia severity, small sample sizes, and follow-up periods. These weaknesses should be addressed in well-designed future studies. LEVEL OF EVIDENCE: Level III, therapeutic study.

Promising outcomes of hip mosaicplasty by minimally invasive anterior approach using osteochondral autografts from the ipsilateral femoral head.

PURPOSE: Recent studies demonstrated promising results of mosaicplasty for femoral head osteochondral lesions using posterior and lateral approaches. This study aimed to evaluate outcomes of mosaicplasty using ipsilateral femoral head autografts by minimally invasive anterior approach. The hypothesis was that this surgical technique would grant satisfactory clinical outcomes with considerable improvement of clinical scores. METHODS: A consecutive series of 27 mosaicplasties, to treat osteochondral lesions of the femoral head measuring 1.6 ± 0.7 cm2 (range 0.8-4.0) in patients aged 28.7 ± 7.4 years (range 19-44), was evaluated using the mHHS and WOMAC scores at minimum follow-up of 12 months. All patients were operated by minimally invasive anterior (Hueter) approach and osteochondral plugs were harvested from the non-weight-bearing portion of the femoral head. Adjuvant osteoplasty was necessary for some patients at the acetabulum (n = 3), femur (n = 14) or both (n = 2). RESULTS: Three patients were excluded due to concomitant periacetabular osteotomies or shelf procedures, one patient could not be reached, and another was revised to THA. This left 22 patients for clinical assessment at 39.4 ± 23.2 months (12.0-90.2). Their mHHS improved from 56.3 ± 12.6 to 88.4 ± 9.9, and WOMAC improved from 45.1 ± 16.9 to 80.6 ± 13.0. Two patients (8.4%) underwent arthroscopy at 13 and 30 months to remove painful residual cam-type deformities. Regression analyses revealed that net improvement in WOMAC decreased with lesion size (p = 0.002) and increased with follow-up (p = 0.004). CONCLUSIONS: Hip mosaicplasty using autografts from the ipsilateral femoral head, performed by minimally invasive anterior approach, granted satisfactory outcomes and functional improvements. Caution is, however, advised for lesions > 2 cm2 (diameter > 16 mm) which may be a threshold limit for this procedure. LEVEL OF EVIDENCE: Level IV, Case series.

The Direct Anterior Approach for Total Hip Arthroplasty for Severe Dysplasia (Crowe III and IV) Provides Satisfactory Medium to Long-Term Outcomes.

BACKGROUND: The direct anterior approach (DAA) is increasingly used for total hip arthroplasty (THA). Although the DAA can reduce pain, recovery time, and dislocations in nondysplastic hips, few studies report its results in patients with severe dysplasia. We aimed to evaluate outcomes of primary THA through the DAA with cup placement at the true acetabulum in hips with severe dysplasia. METHODS: We retrospectively evaluated 23 consecutive patients (29 hips) who underwent THA by DAA for osteoarthritis secondary to Crowe III-IV dysplasia. Surgical procedures were performed on a traction table, and the acetabular cup was placed in the true acetabulum. Patients were assessed clinically (complications, modified Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Hip Score) and radiographically (radiolucencies, subsidence, leg length discrepancies, cup inclination, and cup coverage) at a minimum of 2 years. RESULTS: One patient (2 hips) died with original implants (at 13 and 14 years), 3 patients (3 hips) were revised due to wear-induced loosening (at 14, 16, and 18 years), and there were no dislocations or infections. The remaining 19 patients (24 hips) were assessed at 8.4 ± 4.7 years (range 2-20); 2 patients (2 hips) had complications that required reoperation without implant removal. The modified Harris Hip Score improved from 32 ± 9 to 94 ± 7, Western Ontario and McMaster Universities Osteoarthritis Index from 46 ± 18 to 90 ± 7, and Oxford Hip Score was 56 ± 4. Patients were very satisfied (90%) or satisfied (10%). Limb length discrepancy was 2.5 ± 9.0 mm. CONCLUSION: THA through the DAA with cup placement at the true acetabulum provides satisfactory mid to long-term clinical and radiographic outcomes compared to other approaches for hips with severe dysplasia. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Treatment of Hip Microinstability with Arthroscopic Capsular Plication: A Retrospective Case Series.

Purpose: Hip microinstability is defined as hip pain with a snapping and/or blocking sensation accompanied by fine anatomical anomalies. Arthroscopic capsular plication has been proposed as a treatment modality for patients without major anatomic anomalies and after failure of properly administered conservative treatment. The purpose of this study was to determine the efficacy of this procedure and to evaluate potential predictors of poor outcome. Materials and Methods: A review of 26 capsular plications in 25 patients was conducted. The mean postoperative follow-up period for the remaining patients was 29 months. Analysis of data included demographic, radiological, and interventional data. Calculation of pre- and postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis) index was performed. Pre- and postoperative sports activities and satisfaction were also documented. A P<0.05 was considered significant. Results: No major complications were identified in this series. The mean pre- and postoperative WOMAC scores were 62.6 and 24.2, respectively. The WOMAC index showed statistically significant postoperative improvement (P=0.0009). The mean satisfaction rate was 7.7/10. Four patients with persistent pain underwent a periacetabular osteotomy. A lateral center edge angle ≤21° was detected in all hips at presentation. We were not able to demonstrate any difference in postoperative evolution with regard to the presence of hip dysplasia (P>0.05), probably because the sample size was too small. Conclusion: Capsular plication can result in significant clinical and functional improvement in carefully selected cases of hip microinstability.

Cerclage wire or positional cortical screw for the treatment of intraoperative calcar fractures during primary total hip arthroplasty? A biomechanical study.

BACKGROUND: During primary total hip arthroplasty, intra-operative calcar fractures have been historically treated with cerclage wires. However, interfragmentary screw fixation technique can possibly achieve the same results with technical advantages. The aim of this biomechanical study was to assess stability of calcar fractures fixed using interfragmentary screw technique compared to a traditional cerclage system specifically in context of total hip arthroplasty. METHODS: Thirty-two periprosthetic fractures were reduced using either a single cerclage cable or an intracortical positional screw perpendicular to the fracture line. Axial and torsional load testing was terminated after experimental model failure. FINDINGS: No significant difference was obtained for all output parameters when comparing cerclage wires versus interfragmentary screw fixation respectively. Load at failure: 8043 ± 712 N vs 7425 ± 854 N (p = 0.115). Load at calcar fracture propagation: 6240 ± 2207 N versus 6220 ± 966 N (p = 0.668). Maximum stiffness before failure: 617 ± 115 N/mm vs 839 ± 175 N/mm (p = 0.100) and stiffness at calcar fracture propagation reached 771 ± 153 Nmm vs 886 ± 129 N/mm (p = 0.197). Torque to failure levels obtained were 59.4 ± 7.1 N*m vs 60.9 ± 12.0 N*m (p = 0.908). Torque to calcar fracture propagation, 51.6 ± 6.1 N*m vs 48.5 ± 9.8 N*m (p = 0.298). Torsional stiffness at failure, 0.38 ± 0.03 N*m\deg. vs 0.43 ± 0.13 N*m\deg. (p = 0.465). Torsional stiffness at calcar fracture propagation were 0.37 ± 0.03 N*m\deg. vs 0.45 ± 0.17 N*m\deg. (p = 0.462). INTERPRETATION: The strength of fixation and stability of the implant were similar for both techniques. In the synthetic bone model tested, using an interfragmentary screw conveyed similar stability to the constructs in the management of an intra-operative medial calcar fractures. Thus, potentially giving surgeons an alternative option for intraoperative fracture fixation during primary total hip arthroplasty.

Periacetabular osteotomy with intraoperative computer-assisted modalities: a systematic review.

The role of intraoperative computer-assisted modalities for periacetabular osteotomy (PAO), as well as the perioperative and post-operative outcomes for these techniques, remains poorly defined. The purpose of this systematic review was to evaluate the techniques and outcomes of intraoperative computer-assisted modalities for PAO. Three databases (PubMed, CINAHL/EBSCOHost and Cochrane) were searched for clinical studies reporting on computer-assisted modalities for PAO. Exclusion criteria included small case series (<10 patients), non-English language and studies that did not provide a description of the computer-assisted technique. Data extraction included computer-assisted modalities utilized, surgical techniques, demographics, radiographic findings, perioperative outcomes, patient-reported outcomes (PROs), complications and subsequent surgeries. Nine studies met the inclusion criteria, consisting of 208 patients with average ages ranging from 26 to 38 years. Intraoperative navigation was utilized in seven studies, patient-specific guides in one study and both modalities in one study. Three studies reported significantly less intraoperative radiation exposure (P < 0.01) in computer-assisted versus conventional PAOs. Similar surgical times and estimated blood loss (P > 0.05) were commonly observed between the computer-assisted and conventional groups. The average post-operative lateral center edge angles in patients undergoing computer-assisted PAOs ranged from 27.8° to 37.4°, with six studies reporting similar values (P > 0.05) compared to conventional PAOs. Improved PROs were observed in all six studies that reported preoperative and post-operative values of patients undergoing computer-assisted PAOs. Computer-assisted modalities for PAO include navigated tracking of the free acetabular fragment and surgical instruments, as well as patient-specific cutting guides and rotating templates. Compared to conventional techniques, decreased intraoperative radiation exposure and similar operative lengths were observed with computer-assisted PAOs, although these results should be interpreted with caution due to heterogeneous operative techniques and surgical settings.

Surgical Technique and Case Series of Total Hip Arthroplasty with the Hueter Anterior Approach for Crowe Type-IV Dysplasia.

BACKGROUND: Total hip arthroplasty (THA) is being increasingly performed via the Hueter anterior approach (HAA), which has proven benefits with nondysplastic hips; however, little has been published on its outcomes with dysplastic hips, where it can provide better acetabular exposure. We describe our technique for THA via the HAA in hips with Crowe type-IV developmental dysplasia and report the mid-term outcomes of cases that were performed over 5 consecutive years. METHODS: We retrospectively evaluated a continuous series of 8 hips (6 patients) with Crowe type-IV dysplasia; the patient ages ranged from 44 ± 20 years (range, 17 to 65 years) at the index THA. All of the patients received uncemented implants via the HAA on a traction table to restore the hip center of rotation to the true acetabulum. Femoral head autografts (FHAs) were used to increase acetabular coverage in 6 hips, and subtrochanteric shortening osteotomies (SSOs) were performed in 5 hips. Patients were assessed clinically and radiographically at a minimum follow-up of 2 years. RESULTS: There were no revisions, deaths, dislocations, or infections. Two hips (25%) had intraoperative complications, and 1 hip (13%) had a postoperative complication that required reoperation without implant removal. All of the hips were assessed clinically and radiographically at 4 ± 1 years (range, 2 to 6 years). The modified Harris hip score (mHHS) improved from 33 ± 7 to 90 ± 7, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) improved from 53 ± 14 to 89 ± 6; the postoperative leg-length discrepancy was 3.2 mm (range, -10 to 20 mm). None of the hips had osteolysis or radiolucent lines of >2 mm. CONCLUSIONS: THA via the HAA on a traction table for hips with Crowe type-IV dysplasia yielded satisfactory mid-term outcomes. Both FHA and SSO can be adequately performed via the HAA to help restore the hip center of rotation to the true acetabulum. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Femoroacetabular impingement treatment using arthroscopy and anterior approach.

Femoroacetabular impingement (FAI) has been identified as a common cause of hip pain in young adults. However, treatment is not well standardized. We retrospectively reviewed 97 patients (100 hips) who underwent osteochondroplasty of the femoral head-neck for FAI using a mini-open anterior Hueter approach with arthroscopic assistance. The mean age of the patients was 33.4 years. The labrum was refixed in 40 hips, partially excised in 39 cases, completely excised in 14 cases, and left intact in seven. Six patients were lost to followup, leaving 91 (94 hips) with a minimum followup of 28.6 months (mean, 58.3 months; range, 28.6-104.4 months). We assessed patients clinically using the nonarthritic hip score (NAHS). One patient had a femoral neck fracture 3 weeks postoperatively. At the last followup, the mean NAHS score increased by 29.1 points (54.8 +/- 12 preoperatively to 83.9 +/- 16 points at last followup). Eleven hips developed osteoarthritis and subsequently had total hip arthroplasty. The best results were obtained in patients younger than 40 years old with a 0 Tönnis grade. Refixation of the labrum did not correlate with a higher NAHS score (87 +/- 11 with refixation versus 82 +/- 19 points without) at the last followup. The technique for FAI treatment allowed direct visualization of the anterior femoral head-neck junction while avoiding surgical dislocation, had a low complication rate, and improved functional scores.

Capsulotomy first: a novel concept for hip arthroscopy.

Capsulotomy during hip arthroscopy improves the mobility of arthroscopic instruments and helps gain greater access to key areas of the hip. During the past decade, its use has expanded dramatically as the complexity of hip arthroscopy has advanced. We report a novel approach for hip arthroscopy that consists of performing an extra-articular capsulotomy under endoscopic control before exploration of the hip joint. The principle of this new concept is to replicate an anterior Hueter approach of the hip joint. We describe the surgical technique and discuss its advantages compared with conventional hip arthroscopy techniques using either a peripheral- or central-compartment starting point. This new approach is easy to master, can be performed with a 30° optic system, does not require fluoroscopic assistance, allows a reduction in both the force and duration of traction, and reduces the risk of labral or chondral damage.

Revision total hip arthroplasty performed through the Hueter interval.

Revision total hip arthroplasty through the direct anterior approach is technically challenging but offers some advantages in exposure of the acetabulum. This study presents a retrospectively reviewed consecutive series of fifty-one patients who underwent revision total hip arthroplasty through the anterior approach utilizing various extensions of this technique. The anatomic approach is discussed as well as problems as encountered in our series.

Anterior femoroacetabular impingement.

Anterior femoroacetabular impingement is a mechanical hip disorder defined as abnormal contact between the anterior acetabular rim and the proximal femur. The typical patient is a young man who practices a martial art that involves kicking. Mechanical groin pain is the main presenting symptom. Passive flexion and internal rotation of the hip replicates the pain. The range of internal rotation is often limited. Imaging studies show a non-spherical femoral head or overhang of the anterior acetabular rim. Computed arthrotomography or magnetic resonance arthrography visualize focal damage to the anterosuperior labrum and sometimes to the acetabular cartilage. Discontinuing the activity associated with the harmful hip movement is the main treatment. However, arthroplasty and removal of damaged labral tissue may be required. Surgical outcomes correlate negatively with the severity of the cartilage lesions.

Two-stage surgical procedure for treating pelvic malunions.

When surgically treated, pelvic-ring deformities due to post-traumatic malunions in adults usually require invasive three-stage (prone/supine/prone or supine/prone/supine) procedures. A standardised two-stage prone/supine procedure was developed by the authors. Technical points and first clinical results are presented. Malunuions related to Tile B and C types of fracture were successfully corrected.