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.

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.

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.

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.

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.

[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.

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.

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.

Biomechanical stability of an arthroscopic anterior capsular shift and suture anchor repair in anterior shoulder instability: a human cadaveric shoulder model.

It was hypothesized that an arthroscopic Bankart repair with suture anchors supplies sufficient anterior shoulder stability, which cannot be improved by an additional capsular shift. In an experimental biomechanical human cadaver study, we tested ten fresh human cadaver shoulders in a robot-assisted shoulder simulator. External rotation and glenohumeral translation were measured at 0 degrees and 80 degrees of glenohumeral abduction. All measurements were performed under the following conditions: on the non-operated shoulder; following the setting of three arthroscopic portals; following an arthroscopic anterior capsular shift; following a simulated Bankart lesion; and following an arthroscopic Bankart repair. The application of three arthroscopic portals resulted in a significant increase of the anterior (P = 0.01) and antero-inferior translation (P = 0.03) at 0 degrees and 80 degrees abduction, as well as an increase in external rotation at 80 degrees abduction (P = 0.03). Capsular shift reduced external rotation (P = 0.03), but did not significantly decrease translation. Simulating anterior shoulder instability, glenohumeral translation significantly increased, ranging from 50 to 279% of physiological translation. Arthroscopic shoulder stabilization resulted in a decrease of translation in all tested directions to approximately physiologic levels. External rotation in 0 degrees abduction was thus decreased significantly (P = 0.003) to an average of 19 degrees . The study proved that an arthroscopic anterior capsular shift in a cadaveric model decreases external rotation without a significant influence on glenohumeral translation. Arthroscopic shoulder stabilization with suture anchors thus sufficiently restores increased glenohumeral translation, but also decreases external rotation in neutral abduction. An anatomic reconstruction of the Bankart lesion without overconstraining of the antero-inferior capsule should therefore be the aim in arthroscopic anterior shoulder stabilization.

Influence of an infrapatellar fat pad edema on patellofemoral biomechanics and knee kinematics: a possible relation to the anterior knee pain syndrome.

INTRODUCTION: An edema of the infrapatellar fat pad following knee arthroscopy or in case of chronic anterior knee pain syndrome is suspected to increase the patellofemoral pressure by a modification of the patellofemoral glide mechanism. The study was performed to evaluate this hypothesis. MATERIALS AND METHODS: Isokinetic knee extension from 120 degrees of flexion to full extension was simulated on 10 human knee cadaver specimens (six males, four females, average age at death 42 years) using a knee kinemator. Joint kinematics was evaluated by ultrasound sensors (CMS 100, Zebris, Isny, Germany), and retro-patellar contact pressure was measured using a thin-film resistive ink pressure system (K-Scan 4000, Tekscan, Boston). Infrapatellar tissue pressure was analyzed using a closed sensor cell which was implanted inside the fat pad (GISMA, Buggingen, Germany). An inflatable fluid cell was implanted by ultrasound control in the center of the infrapatellar fat pad and filled subsequently with water to simulate a fat pad edema. All parameters were recorded and analyzed from 0 to 5 ml volume of the fluid cell. RESULTS: Simulating a fat pad edema resulted in a significant (P < 0.01) increase of the infrapatellar fat pad pressure (247 mbar at 0 ml to 615 mbar at 5 ml volume). In knee extension and flexion the patella flexion (sagittal plane) was decreased while we did not find any other significant influence of the edema on knee kinematics. During the analysis of the patellofemoral biomechanics, a simulated fat pad edema resulted in a significant (P < 0.05) decrease of the patellofemoral force between 120 degrees of knee flexion and full extension. The contact area was reduced significantly near extension (0 degree-30 degrees) by an average of 10% while the contact pressure was reduced at the entire range of motion up to 20%. CONCLUSION: An edema of the infrapatellar fat pad does not cause an increase of the patellofemoral pressure or a significant alteration of the patellofemoral glide mechanism. Anterior knee pain in case of a fat pad edema may be related to a significant increase of the tissue pressure and possible histochemical reactions.

[Modified technique of trapezius transfer to improve function in brachial plexus palsy]. / Modifizierte Technik der Verpflanzung des Musculus trapezius zur Funktionsverbesserung bei Armplexusschäden.

OBJECTIVE: Increase of shoulder stability. Elimination of inferior subluxation of the humeral head. Increase of active abduction. Better control of the paralyzed arm. Decrease or elimination of shoulder pain. INDICATIONS: Palsy of deltoid and supraspinatus muscles with weak abduction, multidirectional shoulder instability and subluxation of the humeral head after complete neurosurgical therapy (neurolysis, reconstruction of the brachial plexus). No essential active function of the elbow and hand. CONTRAINDICATIONS: Weakness of trapezius muscle. Incomplete rehabilitation after neurosurgical procedure. Stiffness of the glenohumeral joint. Arthritis of the glenohumeral joint. SURGICAL TECHNIQUE: The cranial part of the trapezius muscle is detached from the scapular spine and the clavicle. Its insertion at the acromion is left untouched. The acromion is freed from the scapular spine and the lateral end of the clavicle by oblique osteotomies and then transferred to the proximal humerus. Under maximum tension the deltoid muscle is sutured on top of the trapezius muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the arm in an abduction support (75 degrees of abduction) for 6 weeks. The physiotherapy program starts on the 1st postoperative day with assisted and active training of elbow, hand, and fingers. During the 1st postoperative week, the abduction support is removed for physiotherapy, abduction is maintained during the exercises. After 6 weeks, progressive adduction to remove the abduction support is commenced. RESULTS: The procedure was performed in 104 cases. 80 patients were followed up on average after 2.4 years (0.8-8 years). In all cases, the transfer resulted in an increase of function and in 95% in a decrease of multidirectional shoulder instability. The modification of the original technique in the latest 22 cases was superior in terms of shoulder stability. In all these cases, a decrease of instability was achieved and inferior subluxation was abolished.

[External rotation osteotomy of the humerus for treatment of external rotation deficit in palsies]. / Aussenrotationsosteotomie des Humerus zur Behandlung des lähmungsbedingten Aussenrotationsdefizits der Schulter.

OBJECTIVE: Aim of the procedure is shifting the arc of shoulder rotation for an improved external rotation, reaching a physiological elbow flexion without striking of the lower arm against the thorax; improvement of the activities of daily living because guidance of the hand to the face is possible without any simultaneous evasive movements of the shoulder. INDICATIONS: Palsy of infraspinatus and teres minor muscles after complete neurosurgical therapy (neurolysis, reconstruction of the brachial plexus), which leads to loss of external rotation and an internally rotating posture of the arm. Elbow flexion is hindered because of striking of the lower arm against the thorax, simultaneous abduction and foreward flexion is necessary to guide the hand to the face. CONTRAINDICATIONS: Not completed rehabilitation after a neurosurgical procedure. Stiffness of the glenohumeral joint with insufficient passive overall rotational sector due to additional reduced internal rotation. SURGICAL TECHNIQUE: To improve external rotation by shifting of the arc of rotation, a transverse osteotomy is done in the mid third of the humerus and the distal part of the humerus is rotated outward (30-60 degrees ). A dynamic compression plate is used for osteosynthesis. POSTOPERATIVE MANAGEMENT: Immobilization of the arm in a Gilchrist bandage is necessary for 6 weeks (especially at night). The physiotherapy program starts on the 1st postoperative day with assisted and active training of elbow, hand, and fingers, as well as active external rotation of the shoulder. After 6 weeks, all movements and daily activities are allowed. RESULTS: The procedure was performed in 15 cases, followed up on average after 3 years (0.5-8.7 years). In all cases, the shifted arc of rotation (preoperative 37 degrees deficit of external rotation, postoperative 46 degrees increase) eliminated striking of the lower arm against the thorax on flexion of the elbow. All patients were able to guide their hands to their faces without any simultaneous evasive movements of the shoulder.

[Arthroscopic meniscal repair with bioresorbable implants].

OBJECTIVE: Restoration of the shape and function of a torn meniscus. INDICATIONS: Complete or large incomplete longitudinal tear of the medial and lateral meniscus close to the base, large flap tear, so-called bucket-handle tear. CONTRAINDICATIONS: Degenerative meniscal tissue. Unstable knee joint without concomitant surgical stabilization. Complex meniscal tear or radial tear. Tear in the central avascular region. Gonarthrosis. Joint infection. Local skin disorders. SURGICAL TECHNIQUE: Visualization of the meniscal tear and revitalization of the tear margins with a meniscal rasp or shaver. Introduction of the implant using the surgical technique required and repair of the tear. Percutaneous trepanation of the meniscal base ("needling") to improve healing. POSTOPERATIVE MANAGEMENT: Full weight bearing only with the knee joint extended in an orthosis until after the 6th postoperative week. Knee flexion up to 30 degrees without weight bearing for the first 2 postoperative weeks with physiotherapy, then up to 60 degrees for another 4 weeks. Short movable knee orthosis with 0-0-90 degrees in the 7th-12th postoperative week. After the 12th postoperative week, continuation of physiotherapy without orthosis, until range of movement has been achieved and the knee-stabilizing muscles have regained their strength. Full sporting capacity after 6 months. RESULTS: The healing rate for meniscal repair with bioresorbable implants is between 86% and 95% and is comparable with the average healing rate for open (84-88%) or arthroscopic suture techniques (98%). Between July 1999 and June 2001, a meniscal tear was treated with Clearfix screws in 65 patients. 60 patients (92%) had a follow-up examination on average 18 months postoperatively. Six patients underwent further arthroscopic surgery as a result of pain (four times healed, twice not healed). Another three patients complained of pain on weight bearing at the follow-up examination and had clinically positive meniscus signs. These patients were then evaluated as "treatment failures". The clinical healing rate was therefore 92% (55 out of 60).

Biomechanical and kinematic influences of a total infrapatellar fat pad resection on the knee.

BACKGROUND: This biomechanical study was performed to evaluate the consequences of total infrapatellar fat pad resection on knee kinematics and patellar contact pressure. HYPOTHESIS: Resection of the infrapatellar fat pad produces significant changes in knee kinematics and patellar contact pressure. STUDY DESIGN: Biomechanical cadaveric study. METHODS: Isokinetic knee extension was simulated on 10 human knee cadaveric specimens (6 men, 4 women; mean age at death, 44 years). Joint kinematics were evaluated by an ultrasound-based 3D motion analysis system, and retro-patellar contact pressure was measured using an electronic pressure-sensitive film. All data were taken before and after resection of the infrapatellar fat pad and statistically analyzed. RESULTS: A total resection of the infrapatellar fat pad resulted in a significant decrease of the tibial external rotation relative to the femur between 63 degrees of flexion and full knee extension (maximum: 3 degrees rotation difference at 0 degrees knee flexion, P = .011), combined with a significant medial translation of the patella between 29 degrees and 69 degrees of knee flexion (range, 0.9-1.3 mm, P = .017-.028). Retro-patellar contact pressure was significantly reduced (from 20% to 25%, P = .008-.021) at all flexion angles. CONCLUSION: A resection of the infrapatellar fat influences patellar biomechanics and knee kinematics. CLINICAL RELEVANCE: The infrapatellar fat pad may have a biomechanical function and may play a role in anterior knee pain syndrome.

Risk evaluation of thermal injury to the cervical spine during intradiscal laser application in vitro.

OBJECTIVE: We aimed to investigate temperature distribution during laser and its possible thermal damage to the neurovascular structures. BACKGROUND DATA: Percutaneous laser disc decompression (PLDD) is now being performed as a minimally invasive intradiscal technique for the operative therapy of non-sequestered herniated cervical discs. As yet, no experimental basic research has been reported with regard to temperature rise and distribution in the cervical region during laser radiation. MATERIALS AND METHODS: An in vitro laser procedure was performed on human cervical intervertebral discs under standardized conditions. A thermo-camera was used to monitor in real-time the zones sensitive to temperature increase. RESULTS: Average intervertebral disc volume was 2000 mm3. With a total energy conduction of 600 Joules, a temperature increase of around 30 degrees C was shown with an initial temperature of 28 degrees C at the posterior longitudinal ligament lying immediately in front of the myelon. The defect volume was less than 1% of the total intervertebral disc volume. CONCLUSION: If, during laser application, the total amount of conducted energy is too high, with an unfavorable position of the fibers in the intervertebral space, there is a risk of thermal damage to the spinal cord and nerve roots.

Reconstructive operations for the upper limb after brachial plexus palsy.

Limited function due to paralysis following brachial plexus lesions can be improved by secondary operations of the bony and soft tissue. Between April 1994 and December 2000, 109 patients suffering from arm-plexus lesions underwent a total of 144 reconstructive operations guided by our concept of integrated therapy. The average age at the time of surgery was 32 years (range: 15-59). The following operations were performed: shoulder arthrodesis (23), trapezius transfer (74), rotation osteotomy of humerus (9), triceps to biceps transposition (9), transposition of forearm flexors or extensors (8), latissimus transfer (7), pectoralis transfer (1), teres major transfer (1), transposition of flexor carpi ulnaris to the tendons of extensor digitorum (10), and wrist arthrodesis (2). Prospectively, in all patients, the grade of muscle power of the affected upper extremity was evaluated prior to surgery. The follow-up period for all 144 operations was, on average, 22 months (range: 6-74). By means of operative measures, almost all patients obtained an improvement of shoulder function (100%) and stability (>90%), elbow flexion (85%), and hand, finger, and thumb (100%). When muscles malfunction after brachial plexus lesions, one should take into account the individual neuromuscular defect, passive joint function, and bony deformities; different procedures such as muscle transpositions, arthrodeses, and corrective osteotomies can then be performed to improve function of the upper extremity. Each form of operative treatment presents patients with certain benefits and all are integrated into a total treatment plan for the affected extremity.

Osteotomy of the humerus to improve external rotation in nine patients with brachial plexus palsy.

Malfunction of the infraspinatus muscle and teres minor muscle illustrate the typical clinical picture in patients with brachial plexus palsy. The arm hangs down in an inwardly rotated position and elbow flexion is hindered by striking of the lower arm against the thorax. Between 1995 and 2000, we have done external rotational osteotomy of the humerus for nine patients with brachial plexus palsy. The mean age of the patients at the time of operation was 29 years (range 15 to 42). The mean follow-up time was 24 (6 to 69) months. Preoperatively, the patients all had appreciable deficits of external rotation (mean deficit 37 degrees, range 10 degrees to 70 degrees). As a result of osteotomy, external rotation was improved in all patients, the mean increase being 42 degrees (range 25 degrees to 60 degrees). All patients were subjectively content with the improved position of the arm and its function. They were able to move their hands to their faces without striking the lower arm against the chest on elbow flexion, or without compensatory evasive movement of the shoulder.

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.

[Replacement of the Glenoid Using a Reconstruction Socket (EPOCA RECO]. / Endoprothetischer Glenoidersatz mit Rekonstruktionsschale (EPOCA RECO).

OBJECTIVE: Alleviation of pain, restoration of function and active range of motion in the shoulder in case of cuff tear arthropathy. INDICATIONS: Cuff tear arthropathy with an insufficient coracoacromial arch and salvage operation of failed hemiprosthesis or reverse shoulder prosthesis. CONTRAINDICATIONS: Active or chronic infections. Lesions of the plexus. Insufficiency of deltoid muscle or subscapularis muscle. Neurologic diseases. Young active patients. SURGICAL TECHNIQUE: Deltopectoral approach. Resection of the humeral head and removal of the failed implant, respectively. Periarticular arthrolysis with preservation of neurovascular structures. Exposure of the glenoid and three-point fixation of the reconstruction socket (EPOCA RECO) at the glenoid, the acromion and the coracoid process. Cemented fixation of the polyethylene inlay. Cemented or cementless implantation of the humeral stem in 25 degrees retroversion related to the long axis of the forearm. Reconstruction of the subscapularis muscle. POSTOPERATIVE MANAGEMENT: Bedding of the arm in a Gilchrist brace. Passive and active- assisted exercises including continuous passive motion. RESULTS: From 2002 to 2007, a total of 35 reconstruction sockets (EPOCA RECO) were implanted in 34 patients (six men, 28 women - one bilateral implantation was performed at an interval of 8 months in a female patient). Five EPOCA RECO implants had to be removed due to major complications. Three patients died, another three patients refused the follow-up examination. The remaining 23 patients (three men, 20 women, average age at the time of surgery 76 years [64-88 years]) were examined 2 years (4-60 months) postoperatively. The preoperative gender-related Constant Score was 21 and improved significantly (p < 0.001) to 58 postoperatively. The pain was significantly reduced. Range of motion for active elevation, internal and external rotation was improved (preoperatively/ postoperatively): elevation 37.2 degrees/65 degrees; internal rotation 14.8%/50%; external rotation 11.3%/47.5%. All patients would undergo the operation again. Overall, there were five major and two minor complications (complication rate 20%).