Amorphous calcium deposits of the hip joint: current observations and state of the scientific discussion.

INTRODUCTION: As a result of increasing hip arthroscopies, rare pathologies as intra-articular amorphous calcium deposits in the capsule-labral (perilabral) recess can be recognized. There is a lack of publications on this pathology. The largest case series included 18 patients. An association between femoroacetabular impingement syndrome (FAIS) and female sex was observed. Furthermore, a correlation between the size of the calcific deposit and the preoperative hip function score was reported. Our hypothesis was that the data of our patient collective with intraoperative amorphous calcium deposits of the hip joint are comparable to the existing data to confirm previous observations. MATERIALS AND METHODS: From 01/2018 to 08/2020, a total of 714 hip arthroscopies were performed. 12 (1.7%) patients who presented intra-articular amorphous calcium deposits during arthroscopy were included. On radiographs, signs of impingement and osteoarthritis were determined. Characteristics and size of the calcific deposits were examined. Preoperative and at the time of follow-up (23 months), patient-reported outcome scores (PROS) were evaluated. Duration of symptoms, pain medication, comorbidities, and return-to-work were evaluated too. RESULTS: The PROS of the four female and eight male patients improved significantly. The average size of the calcific deposit was 6.9 mm in the anteroposterior radiographs. Separation of the calcific deposit from the acetabular rim was seen in nine cases. No correlation between deposit sizes and PROS was found. Cam morphology was treated in ten cases. All patients returned to work after a median of 7 weeks (2.5-13 weeks). CONCLUSION: Amorphous calcium deposits were found in approximately 1% of all hip joints with indication for hip arthroscopy. They are not consistently associated with gender, intra-articular hip pathologies or comorbidities. The clustered occurrence in cam FAI can be justified solely by the fact that impingement is by far the most common indication for hip arthroscopy.

Prone Apprehension Relocation Test significantly correlates with radiological instability scores of the hip.

Recently, there was a debate about whether borderline dysplastic hips should be treated surgically with hip arthroscopy or periacetabular osteotomy (PAO). Current studies recommend a classification into stable and unstable hips. Therefore, radiological scores have been described in recent years. Likewise, a new clinical stability test with the Prone Apprehension Relocation Test (PART) has been described. However, there has been no correlation between the modern radiological scores and the PART. We prospectively studied a consecutive group of patients who presented to our clinic. The PART and radiological scores were assessed in these patients. We divided the patients into a PART-positive and a PART-negative group and analyzed the associated clinical and radiological findings. Out of 126 patients (126 hips) included, 36 hips (29%) were evaluated as PART positive. There were significantly more females in the PART positive group (P = 0.005). Comparing the PART groups, significant differences (P < 0.0001) were found for the lateral center edge angle (LCEA), Femoro-Epiphyseal Acetabular Roof (FEAR) index, Gothic arch angle (GAA), anterior wall index (AWI), the occurrence of the upsloping lateral sourcil (ULS) and signs of acetabular retroversion. The correlation analysis showed an association between LCEA, FEAR index, GAA, AWI, ULS and the PART. A chi-square automatic interaction detection algorithm revealed that the strongest predictor of positive PART was the GAA. In conclusion, a high correlation between the PART and known radiological instability parameters was found. Consequently, a combination of clinical instability testing and radiological instability parameters should be applied to detect unstable hips.

Accuracy of a patient-specific instrumentation for coronal plane alignment of an anatomic alignment total knee arthroplasty system: A radiographic study.

BACKGROUND: Patient-individualised anatomic alignment in total knee arthroplasty (TKA) requires exact positioning of the tibial and femoral components. Patient-specific instrumentation (PSI) may be advantageous for implantation. However, the role of PSI in the instrumentation of such knee designs has not been investigated. OBJECTIVE: The aim of this study was to investigate the accuracy of a PSI system designed for patient-individualised anatomic alignment. METHODS: Fifty-four patients from a single centre were consecutively enrolled in this study. Patient-specific femoral and tibial cutting guides were manufactured using 3D models from computed tomography (CT) scans. All patients received an anatomic TKA implant design through an extension gap first technique. Postoperative radiography was taken, and implant component alignment and leg alignment were compared to the preoperative planning. RESULTS: Thirty-four patients were evaluable. Mean differences between planned angles values obtained from CT scans and the measured radiographic values were small and not significantly different from zero. CONCLUSIONS: Implantation of an anatomic knee design that allows individual component alignment using PSI is feasible. The percentage of component misalignment in the coronal plane was remarkably low. Whether this leads to clinical benefits requires further verification.

[Hip arthroscopy technique]. / Technik der Hüftarthroskopie.

OBJECTIVE: Arthroscopy of the central and peripheral compartment is an obligatory part of hip arthroscopy to evaluate, confirm or find pathologies and their treatment. INDICATIONS: Loose bodies, lesions of the labrum and ligamentum capitis femoris, cartilage damage, femoroacetabular impingement, synovial diseases, initial osteoarthritis, femoral head necrosis (ARCO stage 1-2) and adhesions. CONTRAINDICATIONS: Local infections, bone tumors near the joint, extensive peri-articular ossification, severe arthrofibrosis with peri-articular involvement, advanced osteoarthritis, protrusio acetabuli, advanced femoral head necrosis (from ARCO stage 3-4 extended), recent fracture of the acetabulum and extensive joint capsule tears. SURGICAL TECHNIQUE: Precise positioning of the patient on a fracture table is essential to avoid complications. Central and peripheral compartment arthroscopy requires at least 2, in some cases more than 3 portals. Arthroscopy of the central compartment is carried out under traction by an anterolateral (AL) and anterior portal (A). A posterolateral (PL) portal and distal ventrolateral portal (DVL) may also be required. For peripheral compartment arthroscopy, an anterolateral (AL) and anterior (A), alternatively/additively a proximal ventrolateral portal (PVL) and/or and distal ventrolateral (DVL) portal are established in 45° flexion and no traction of the hip joint. POSTOPERATIVE MANAGEMENT: Mobilization with full weight bearing from the day of the operation, crutches are optional. After stimulating cartilage surgery or autologous chondrocyte transplantation, partial weight bearing of 10 kg on crutches is indicated until the end of postoperative week 6. Physiotherapy with full range of motion allowed, except for labrum refixation, should take place from postoperative day 1. RESULTS: From 01/2010-12/2019, 2815 hip arthroscopies were performed; average patient age 43 (12-81) years. All procedures include a diagnostic arthroscopy of the hip. Two to 5 portals were used. Average operation time was 70 (18-48) min. In 26 cases (0.9%), arthroscopy of the central compartment at a high CE angle was not possible or not performed, even after previous arthroscopy of the peripheral compartment with capsule release. Intraoperative or directly postoperative problems and complications were rare, e.g., damage to the skin/genitals due to contact pressure (0.7%), instrument breakage (0.5%), transient lesions of the pudendus nerve (<1.5%).

Convalescence after arthroscopic capsular release in frozen shoulder.

INTRODUCTION: To determine if arthroscopic capsular release (ACR) shortens duration of illness in frozen shoulder (FS) in comparison to the depicted natural course of 30.1 months and to identify risk factors for persisting complaints. MATERIALS AND METHODS: A consecutive group of 71 shoulders in 70 patients with mean age of 54 (37-74) years with FS were treated by ACR and enrolled in our study with follow-up investigation at 1, 3, 6 and finally 32 (19-49) months postoperatively. RESULTS: Patients had complaints for 8 (3-60) months preoperatively. 8 shoulders (11%) were classified as primary and 63 (89%) shoulders as secondary type FS. 6 patients were lost to follow-up. Relative Constant score increased significantly from 31% before surgery to 103% at last follow-up. 55 patients (85%) achieved subjective remission after 7 (1.5-18) months, postoperatively. Overall duration of illness was 16 (5-72) months. All patients with primary FS achieved remission and all patients with persisting symptoms had secondary FS. CONCLUSION: Duration of illness was shortened by more than 12 months compared with the natural time course defined by Reeves. Secondary FS, especially ac-joint pathologies, previous surgery, diabetes and more than 12 months preoperative illness duration were identified as risk factors for persisting complaints. Hypothesis of worse outcome in secondary FS was confirmed.

Calcifying tendinitis and outlet impingement - Evaluation of the prevalence analyzing radiological and intraoperative criteria.

INTRODUCTION: The question of our study was to evaluate the incidence of coexisting outlet impingement among patients with calcifying tendinitis and a failure of the conservative treatment using intraoperative in addition to radiological criteria.This question is of clinical relevance as there is still a discussion about whether an additional arthroscopic subacromial decompression (ASD) should be performed when arthroscopic removal of the calcific deposits is needed. MATERIALS AND METHODS: From February 2017 to 02/2018, we prospectively enrolled 50 patients who needed shoulder arthroscopy for calcifying tendinitis. We evaluated the x-rays for outlet impingement, measuring the lateral acromial angle (LAA), acromion slope, acromion index (AI) and Bigliani-type of the acromion. During shoulder arthroscopy, we evaluated the acromial undersurface for a bony impingement using a standardized view. If impingement was present, we performed an additional ASD. Before surgery, three months later and at final follow-up 20 months after surgery, we determined the relative Constant Score (rCS). RESULTS: 92.5% of the patients had an intraoperatively confirmed outlet impingement, whereas 82.5% of the patients had a radiological outlet impingement. The sensitivity of the radiographs was 83.8%, the specificity 33.3% when combining all parameters. The mean rCS improved significantly from 45% to 100% at final follow-up. CONCLUSION: Our results show that coexisting outlet impingement is very common in patients with calcifying tendinitis and failure of the conservative treatment. As the radiological diagnosis is uncertain, an intraoperative assessment for impingement is rational and justifies an additional ASD.

Diagnostic Use of Magnetic Resonance Imaging and Magnetic Resonance Arthrography for Intra-Articular Pathologies of the Hip Joint. / Diagnostischer Einsatz von Magnetresonanztomografie und -arthrografie bei intraartikulären Hüftpathologien.

INTRODUCTION: In no other country magnetic resonance imaging (MRI) is as frequently used as in Germany. The study's aim is to analyse a daily referral procedure for hip MRI in German healthcare and to estimate ineffective costs for the healthcare system. MATERIAL AND METHODS: Over one year 203 consecutive MRIs of the hip joint were analysed retrospectively. Referrals were reviewed for their indications, e.g. prevalence of MRIs to detect intra-articular pathologies in the German population was estimated with data of three health insurances. RESULTS: No indication was noted on 21% of the referrals to MRI. On 66% of the referrals a reasonable indications could be identified. There were more uncertainties of the indications for arthrographies. Collecting data concerning the prevalence of MRI for intra-articular hip pathologies is difficult due to the lack of precise diagnosis and procedure coding. The expendable costs caused by MRI of the hip joint amount from 800,000 to 2.4 million € during a one year period. DISCUSSION: Medical referrals should be used thoroughly for communication between referrers and radiologists. Contribution of the letter of referral to health economics is underestimated. To improve estimation of prevalences in the diagnostics of intra-articular hip pathologies, precise diagnosis and procedure codings are needed.

Ultrasound is as reliable as plain radiographs in the diagnosis of cam-type femoroacetabular impingement.

INTRODUCTION: In the diagnosis of femoroacetabular impingement (FAI), plain radiographs are accepted as the initial imaging method. However, there is no consensus regarding the optimal lateral view, and radiographs can underestimate the asphericity of the head-neck junction. Our research question was if ultrasound has at least the same reliability as X-ray and can be used as an alternative or additional method in the initial imaging of FAI. MATERIALS AND METHODS: Forty patients with a median age of 39 years were consecutively included after diagnosis of cam-type FAI on magnetic resonance imaging (MRI). All patients underwent radiography involving a plain anteroposterior-view, frog-leg lateral view, and ultrasound of the hip joint in the ventral longitudinal section at 20° internal rotation. Parameters measured by MRI, radiographs, and ultrasound were the alpha angle, anterior offset, offset ratio, and anterior femoral distance. RESULTS: No significant difference between the alpha angle on MRI (64.8°), the frog-leg view (66.3°), or ultrasound (65.6°) could be detected. Comparable correlation was found between the alpha angle on MRI and the frog-leg lateral view (r = 0.73; p < 0.0001) and between the alpha angle on MRI and sonograms (r = 0.77; p < 0.0001). The intra-class correlation coefficient for measurements using ultrasound was 0.81-0.98, and using radiographs was 0.83-0.99, with the exception of measurements involving the anterior offset on the frog-leg lateral view (0.61 and 0.64). CONCLUSIONS: Ultrasound is as reliable as plain radiographs in the diagnosis of cam-type FAI and can serve as an alternative or additional method in initial imaging.

Patients With Impingement Syndrome With and Without Rotator Cuff Tears Do Well 20 Years After Arthroscopic Subacromial Decompression.

PURPOSE: To present the long-term outcome of arthroscopic subacromial decompression (ASD) for patients with impingement syndrome with or without rotator cuff tears as well as with or without calcific tendinitis in a follow-up of 20 years. METHODS: We included 95 patients after a mean follow-up of 19.9 (19.5 to 20.5) years. All patients underwent ASD, including acromioplasty, resection of the coracoacromial ligament, and coplaning without cuff repair. The Constant score was used to assess the functioning of the shoulder. In addition, we defined a combined failure end point of a poor Constant score and revision surgery. RESULTS: Revision surgery was performed in14.7% of the patients. The combined end point showed successful results in 78.8% of all cases. All patients with isolated impingement syndrome achieved successful results. Those with partial-thickness tears had successful outcomes in 90.9% of all cases, and patients with full-thickness tears had successful outcomes in 70.6% of all cases. The tendinitis calcarea group showed the poorest results, with a 65.2% success rate. CONCLUSIONS: Our long-term results show that patients with impingement syndrome who received ASD, including acromioplasty, resection of the coracoacromial ligament, and coplaning do well 20 years after the index surgery. ASD without cuff repair even appears to be a safe, efficacious, and sustainable procedure for patients with partial rotator cuff tears. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Ultrasonography can quantify the extent of osteochondroplasty after treatment of Cam-type femoroacetabular impingement.

PURPOSE: Surgical resection of femoroacetabular Cam impingement (cam-FAI) is now a generally accepted treatment, producing adequate hip score increases. Insufficient resection at the head-neck junction is the main reason for revision. The anterolateral region of the head-neck junction is visualized only suboptimally by radiography, which can be inadequate for monitoring resection results postoperatively. Our aim was to investigate the extent of Cam resection by ultrasonography (US) and determine if there is any correlation with clinical outcome. METHODS: Altogether, 40 consecutive patients (mean age 39 years) were enrolled in this prospective study following arthroscopic Cam resection. All patients underwent standardized US examination in the ventral longitudinal section at 20° external rotation, neutral position, and 20° internal rotation the day before arthroscopy and two days afterward. Alpha angle, anterior offset, offset ratio, and anterior femoral distance were measured on sonograms. Hip Disability and Osteoarthritis Outcome Score (HOOS) and Western Ontario and McMaster University Index of Osteoarthritis (WOMAC) were conducted the day before surgery and 6 weeks postoperatively (at the earliest). RESULTS: Alpha angle was significantly smaller on postoperative US in all hip joint positions. At 20° internal rotation, the alpha angle decreased from 65.6 to 36.9° (p < 0.0001). All but two (5%) patients had alpha angles <50°. Anterior offset increased significantly on US in neutral position and at 20° internal rotation. HOOS and WOMAC increased significantly. No correlation was found between measurements for Cam-FAI and the scores. CONCLUSIONS: US may be a useful tool for monitoring Cam-FAI resection results postoperatively.

Biomechanical analysis for primary stability of shoulder arthrodesis in different resection situations.

BACKGROUND: Only very few publications dealing with shoulder arthrodesis after bone resection procedures and no biomechanical studies are available. The presented biomechanical analysis should ascertain the type of arthrodesis with the highest primary stability in different bone loss situations. METHODS: On 24 fresh cadaveric shoulder specimens three different bone loss situations were investigated under the stress of abduction, adduction, anteversion and retroversion without destruction by the use of a material testing machine. In each of the testings a 16-hole reconstruction plate was used and compared to arthrodesis with an additional dorsal 6-hole plate. FINDINGS: The primary stability of shoulder arthrodesis with a 16-hole reconstruction plate after humeral head resection could be increased significantly if an additional dorsal plate was used. However, no significant improvement with the additional plate was detected after resection of the acromion. Of all investigated forms, arthrodesis after humeral head resection with additional plate showed the highest and arthrodesis after humeral head resection without additional plate showed the lowest force values. The mean values for forces achieved in abduction and adduction were considerably higher than those in anteversion and retroversion. INTERPRETATION: There are no consistent specifications of arthrodesis techniques after resection situation available, thus the presented biomechanical testings give important information about the most stable form of arthrodesis in different types of bone loss. These findings provide an opportunity to minimize complications such as pseudarthrosis for a satisfying clinical outcome.

Evaluation of Cam-type femoroacetabular impingement by ultrasound.

PURPOSE: In the diagnosis of femoroacetabular impingement (FAI), magnetic resonance imaging (MRI) and X-ray are widely accepted methods for detection. When evaluating the hip head-neck junction using MRI, oblique axial sequences are required. However, the construction and analysis of these images are restricted to specialist radiologists and surgeons in the field of hip joint MRI. This study sought to investigate whether ultrasound, a simple and inexpensive method, can be used as a reliable tool for diagnosing Cam-type FAI. METHODS: Forty patients, with a mean age of 39 years (range, 18-61 years), were consecutively included in this prospective study, following a diagnosis of Cam-type FAI on an oblique axial MRI. All patients underwent ultrasound examination in the ventral longitudinal section at 20° external rotation, neutral position and 20° internal rotation. The alpha angle, anterior offset, offset-ratio, and anterior femoral distance (AFD) were measured using MRI and ultrasound. RESULTS: No significant differences were detected between the alpha angle on MRI and that using ultrasound in the neutral position or in 20° internal rotation, with strong correlations observed between these parameters (r = 0.67 for neutral position, r = 0.77 for 20° internal rotation). The Pearson's correlation coefficient for the alpha angle on MRI and the ratio of AFD/anterior offset on ultrasound in internal rotation was 0.76 (p < 0.0001). CONCLUSIONS: The results show strong correlations between MRI and ultrasound measurements in patients with Cam-type FAI. Consequently, ultrasound may provide a useful tool for the early diagnosis of Cam-type FAI in daily practice.