Introduction. Ascertaining the etiology of hip pain in young patients can be challenging. Osteoid osteoma about the hip has only been described in case reports and small case series in this sub-population. This study assessed the clinical course, radiologic findings, and treatment approaches in a large series of pediatric osteoid osteoma cases about the hip. Potential diagnostic and treatment pitfalls were identified. Methods. A single-center tertiary care departmental database was queried for all cases of osteoid osteoma seen between Jan 1, 2003 and December 31, 2015. Medical records were reviewed to identify those with lesions identified within or around the hip joint. Clinical, demographic, and radiologic data were analyzed. Results. Fifty children and adolescents (56% female, mean age 12.4 years, range 3–19 years) were identified with osteoid osteoma about the hip. The femoral neck was the most common lesion location (38%), and pain in the hip was the most common presenting chief complaint (60%). Night pain (90%) and symptom relief with NSAIDs (88%) were extremely common, though not universally reported. Sclerosis and/or cortical thickening was visible in 58% of radiographs, though a lucent nidus was visible in only 42%. Thirty patients (60%) underwent MRI, 27 of which were available for review, with focal peri-lesional edema as a universal finding. Amongst intracapsular lesions (n=17, 63%), common findings included medial retinacular thickening (33%), synovitis (45%) and effusion (76%). In the 43 patients (48%) who underwent CT, a diagnostic lucent nidus was a universal finding. Initial alternative diagnoses were recorded in 46% of cases, including, in order of decreasing frequency, femoro-acetabular impingement, minor trauma, hip synovitis, ‘growing pain’, stress fracture, and infection. Abnormal hip range of motion, positive impingement signs, and global synovitis on MRI scan were found to be associated with alternative diagnosis. On multivariate regression analysis, only abnormal hip ROM was independently predictive of alternative diagnosis. Delay in diagnosis of >6 months was seen in 43% of patients. Three patients underwent preceding operative procedures for other hip diagnoses, but had persistent hip pain until the osteoid osteoma was treated. Forty-one patients (82%) ultimately underwent radiofrequency ablation (RFA), and 1 open osteoid osteoma resection was performed. Of those who underwent RFA, 93% achieved complete symptom resolution, with 2 of 3 patients without symptom resolution undergoing revision RFA procedure, 1 of which led to symptom resolution. Complications of treatment included 1 case of deep infection along an RFA track, requiring operative debridement, 1 case of transient weakness and paresthesias in the involved extremity, and 1 case of fracture at the RFA site, requiring ORIF. Conclusions. Alternative andelayed diagnoses are common in osteoid osteoma about the hip, with femoro-acetabular impingement representing the most common alternative initial diagnosis in our series. While varying presenting complaints and nonspecific MRI findings may contribute to diagnostic uncertainty, night pain was present in the vast majority of cases and CT scans provided definitive diagnosis in all patients who received them. As increasing numbers of young, active patients are being evaluated for various causes of hip pain, such as femoro-acetabular impingement, osteoid osteoma should not be overlooked in the differential diagnosis of pain about the hip

Aims. To report our experience with trunnion corrosion following metal-on-polyethylene total hip arthroplasty, in particular to report the spectrum of presentation and determine the mean time to presentation. Patients and Methods. We report the presenting symptoms and signs, intraoperative findings, and early results and complications of operative treatment in nine patients with a mean age of 74 years (60 to 86). The onset of symptoms was at a mean of seven years (3 to 18) after index surgery. Results. Patients presented with a variety of symptoms including pain, limp and rash. The preoperative mean serum cobalt level was 7.1 ppb (2.2 to 12.8) and mean serum chromium level was 2.2 ppb (0.5 to 5.2). Metal artifact reduction sequence (MARS) MRI showed fluid collection and possible pseudotumour formation in five hips, fluid collection in two hips, and synovitis/debris in one hip, with no MRI in one patient. Acetabular revision was performed in three patients, six patients underwent liner and head exchange only. The postoperative metal levels decreased in all patients: mean cobalt 0.5 ppb (0 to 1.8) and mean chromium 0.9 ppb (0 to 2.6) at a mean of five months (3 to 8) postoperatively. Seven patients had good pain relief and no complications at one year. There were two major complications requiring reoperation: acute infection at six weeks, for which the patient required two-stage reimplantation; and recurrent dislocation, for which the patient was revised to a dual mobility component. Conclusion. Trunnion corrosion in metal-on-polyethylene THA has a range of presenting symptoms, and may present later than previously described. A high index of suspicion is warranted, and serum cobalt and chromium levels are recommended for diagnosis. Patients should be counselled about possible postoperative complications. Cite this article: Bone Joint J 2018;100-B:898–902

Aims

Hip resurfacing remains a potentially valuable surgical procedure for appropriately-selected patients with optimised implant choices. However, concern regarding high early failure rates continues to undermine confidence in use. A large contributor to failure is adverse local tissue reactions around metal-on-metal (MoM) bearing surfaces. Such phenomena have been well-explored around MoM total hip arthroplasties, but comparable data in equivalent hip resurfacing procedures is lacking. In order to define genetic predisposition, we performed a case-control study investigating the role of human leucocyte antigen (HLA) genotype in the development of pseudotumours around MoM hip resurfacings.

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Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty.

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Avascular femoral head necrosis in the context of gymnastics is a rare but serious complication, appearing similar to Perthes’ disease but occurring later during adolescence. Based on 3D CT animations, we propose repetitive impact between the main supplying vessels on the posterolateral femoral neck and the posterior acetabular wall in hyperextension and external rotation as a possible cause of direct vascular damage, and subsequent femoral head necrosis in three adolescent female gymnasts we are reporting on.

The transtrochanteric anterior rotational osteotomy (TRO) was developed by Sugioka as a joint-preserving procedure which prevents further deformity by transposing the necrotic area from a site of primary weight-bearing to a secondary area. We performed this procedure for children and young adults with various hip disorders. Between 1994 and 2015 we performed TROs on 12 joints in 12 patients with SCFE (4), pigmented villonodular synovitis (2), septic arthritis (1), FAI (1), hip dysplasia (1), femoral neck fracture (2) and postoperative RAO (1). The mean age at the time of surgery was 21 years (10–43) and the mean follow-up period was 8 years (1–22). The rotational directions of the femoral head were anterior (5) and posterior (7). Clinical assessment was undertaken using the system of Merle d'Aubigné and Postel, grading pain, mobility and walking ability with scores from 0 to 6. Radiographically bone regeneration and OA progression were estimated. The mean clinical score improved from 9.0 to 14.4 at final follow-up. Spur formation of femoral head was observed in 7 patients (58%). OA progression was in two patients (17%) and one patient was converted to THA 22 years after surgery. All cases with osteonecrosis in SCFE and femoral neck fracture showed remarkable bone regeneration. The TRO is a reliable joint-preserving procedure for various hip disorders in children and young adults

Trunnion corrosion in metal-on-polyethylene THA is poorly understood, with multifactorial etiology, and the patients present with “hip pain”. We analysed the presenting symptoms and signs, intraoperative findings and the early results and complications of operative treatment. One surgeon treated 9 patients (6 male, 3 female), mean age 74 years, with the onset of symptoms at a mean of 7 years (range 3–18) after index surgery. The taper size was 12/14 in seven, 14/16 in one, and 6 degree in one hip. The preoperative mean cobalt level was 7.1 ppb (range, 2.2–12.8) and mean chromium level was 2.2 ppb (range, 0.5–5.2). MARS MRI showed fluid collection and pseudotumor in 5, fluid collection only in two, and synovitis/debris in one hip. In one patient, there was no preoperative MRI. There were a myriad of clinical presentations: thigh rash alone in one; diffuse leg pain and hip rash in one; acute pseudo-sepsis in one; iliopsoas tendinitis and diffuse rash in one; trochanteric bursitis in one; groin pain only in one; thigh-buttock pain in two; and diffuse hip pain and limp in one patient. Intraoperatively, 6 patients had liner and ceramic (or oxidized zirconium) head exchange only. Three patients had concurrent acetabular revision: one for broken locking mechanism; one because liner was unavailable, and one had acetabular loosening. The postoperative metal levels decreased in all patients: mean cobalt 0.5 ppb (range, 0–1.8) and mean chromium 0.9 ppb (range, 0–2.6). Seven patients had good pain relief and no complications. There were two major complications requiring reoperation: acute infection at 6 weeks and patient required 2-stage reimplantation; and second patient had recurrent dislocation and was revised to a dual mobility component. Trunnion corrosion in metal-on-polyethylene THA has several clinical presentations, including local skin rash, iliopsoas tendinitis, and other limb dysfunction. There should be a high index of suspicion and serum cobalt/chromium levels are recommended for diagnosis. The patients should be counseled about possible postoperative complications

Introduction. Uncertainties in the management of patients with MOM hip implants continue to be a problem for all surgeons. Guidelines vary and do not fully define or quantify thresholds. We aimed to assess the differences in decision-making amongst an international community of six specialist orthopaedic institutions. Methods. Five international tertiary referral orthopaedic units (one UK, two USA, and two European) were invited to participate. Each unit organised an MDT panel consisting of 2 or more hip surgeons and a musculoskeletal radiologist. All units discussed the same 10 patients. A full clinical dataset was provided including blood test and all imaging. Differences in the interpretation of findings, management decision and rationale for decisions were compared between institutions. Results. Asymptomatic patients with metal ions below 7ppb and intra-articular synovitis were collectively treated with monitoring and repeat ion measurement. Symptomatic patients with similar findings were recommended revision surgery by all units. Raised metal ions and a cystic pseudotumour on imaging that is palpable clinically was also consistently recommended revision surgery. Moderate symptoms (OHS 30), 2B pseudotumour, and moderate metal ions (cobalt 5.5ppb) were seen as an indication for revision in 5 units, however the reverse is seen if the patient had several co-morbidities. Further to this, rising blood metal ions (6 to 7.5ppb) was recommended surgery by 4 units, and watchful waiting in 2 units. Rising blood metal ion levels (6ppb to 10ppb) and a small fluid collection on MRI in asymptomatic patients was recommended clinical review and repeat metal ions by 3 units, repeat MRI by 1 unit and revision for suboptimal implant position by the remaining 2 units. Conclusion. Moderate symptoms, blood metal ions and cystic pseudotumours led to inconsistent agreement between institutions. Coordinated international guidance and MDT panel discussions are recommended to improve consensus in decision-making

The differential diagnosis of the painful total hip arthroplasty (resurfacing or total hip) includes infection, failure of fixation (loosening), tendinitis, bursitis, synovitis, adverse local tissue reaction (ALTR) to cobalt-chromium alloys, and non-hip issues, such as spinal disorders, hernia, gynecologic, and other pelvic pain. Assuming that the hip is the source of pain, the first level question is prosthetic or non-prosthetic pain generator? The second level prosthetic question is septic or aseptic? The third level question (aseptic hips) is well-fixed or loose? ALTR is best diagnosed by cross-sectional imaging. Successful treatment is dependent on correct identification and elimination of the pain generator. Treatment recommendations for ALTR and taper corrosion are evolving

We describe a prospective study of 328 patients undergoing arthroscopy of the hip. Arthrography, CT or MRI was performed when clinically indicated. A preoperative diagnosis was reached in 174 patients (53%), while the remaining 154 were diagnosed as having ‘idiopathic hip pain’. In seven patients, access to the hip was inadequate. Arthroscopy altered the diagnosis in 176 hips (53%). The new primary diagnoses were osteoarthritis (75 patients), osteochondral defects (34), torn labra (23), synovitis (11) and loose bodies (9). In 172 hips (52%) an operative procedure was undertaken. In the remaining 84 patients (26%), arthroscopy neither changed the diagnosis nor provided surgical treatment. Arthroscopy of the hip is considered to be of value in assessing and treating the adult patient with pain in the hip of uncertain cause

Aims

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

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To present a surgically relevant update of trunnionosis.

Objectives

Legg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

Aims

There are many guidelines that help direct the management of patients with metal-on-metal (MOM) hip arthroplasties. We have undertaken a study to compare the management of patients with MOM hip arthroplasties in different countries.

Objectives

This study aimed to characterise and qualitatively grade the severity of the corrosion particles released into the hip joint following taper corrosion.

Objectives

The purpose of this study was to compare the thickness of the hip capsule in patients with surgical hip disease, either with cam-femoroacetabular impingement (FAI) or non-FAI hip pathology, with that of asymptomatic control hips.

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The aims of this study were to compare the diagnostic test characteristics of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI) alone, and ultrasound combined with MARS-MRI for identifying intra-operative pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients undergoing revision surgery.

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To determine ten-year failure rates following 36 mm metal-on-metal (MoM) Pinnacle total hip arthroplasty (THA), and identify predictors of failure.

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21.

The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis.

We reviewed the clinical outcome of arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement performed between August 2005 and March 2009 in a series of 40 patients over 60 years of age. The group comprised 26 men and 14 women with a mean age of 65 years (60 to 82). The mean follow-up was 30 months (12 to 54).

The mean modified Harris hip score improved by 19.2 points (95% confidence interval 13.6 to 24.9; p < 0.001) while the mean non-arthritic hip score improved by 15.0 points (95% confidence interval 10.9 to 19.1, p < 0.001). Seven patients underwent total hip replacement after a mean interval of 12 months (6 to 24 months) at a mean age of 63 years (60 to 70). The overall level of satisfaction was high with most patients indicating that they would undergo similar surgery in the future to the contralateral hip, if indicated. No serious complications occurred.

Arthroscopic femoral osteochondroplasty performed in selected patients over 60 years of age, who have hip pain and mechanical symptoms resulting from cam femoroacetabular impingement, is beneficial with a minimal risk of complications at a mean follow-up of 30 months.