Osteotomy of the greater trochanter: effect on gluteus medius function.

PURPOSE: Advancement of the greater trochanter alters the function of the gluteus medius muscle. However, with the exception of clinical studies and biomechanical lever arm studies, no publications that analyze the consequences of advancement of the greater trochanter on the muscle function exist. The aim of the study was to analyze the mechanical changes of gluteus medius after osteotomy of the greater trochanter in a lab setting. METHODS: An anatomical study of origin and insertion of the gluteus medius was carried out on four hips. Based on the dissections, a string model was developed dividing the muscle into five sectors. Changes in muscle fiber length were measured for every 10° of flexion, internal and external rotation and abduction with the trochanter in anatomic, proximalized and distalized positions. RESULTS: Distalization of the trochanter leads to an imbalance of muscle action, moving the isometric sector of the muscle anteriorly with more muscle sectors being active during flexion and less during extension. Stretching of the muscle increases passive forces but decreases the force generation capacity of the muscle and at the same time increased muscle fiber excursion may require more energy consumption, which may explain earlier fatigue of the abductor musculature after distalization of the trochanter. For abduction, distalization of the muscle attachment leads to a change in contraction pattern from isometric to isotonic. Optimal balancing and excursion of the muscle is when the tip of the greater trochanter is at level with the hip rotation center. CONCLUSIONS: In hips with high riding trochanter, the optimal position is at the level of the center of hip rotation. Excessive distalization should be avoided. As the conclusions and considerations are based on a lab setting, transfer to clinical practice may not necessarily apply.

[Arthroscopic fracture management in proximal humeral fractures]. / Arthroskopisch unterstütztes Frakturmanagement am proximalen Humerus.

Arthroscopy has become increasingly more established in the treatment of proximal humeral fractures. In addition to the known advantages of minimally invasive surgery fracture and implant positioning can be optimized and controlled arthroscopically and relevant intra-articular concomitant pathologies (e.g. biceps tendon complex and rotator cuff) can be diagnosed and treated. Arthroscopic techniques have proven to be advantageous in the treatment of various entities of greater tuberosity fractures, lesser tuberosity fractures (suture bridging technique) and subcapital humeral fractures (arthroscopic nailing). This article presents an overview on innovative arthroscopic modalities for treating proximal humeral fractures, describes the surgical techniques and the advantages compared to open procedures as well as initial clinical results.

[Technique and value of arthroscopic implant removal in the shoulder]. / Technik und Stellenwert der arthroskopischen Implantatentfernung an der Schulter.

Arthroscopic implant removal involves innovative minimally invasive surgical techniques which offer the advantages of minimally invasive surgery in addition to the possibility of glenohumeral inspection, arthrolysis and treatment of concomitant intraarticular pathologies compared to open surgical procedures. In the following article the surgical techniques and significance of arthroscopic implant removal from the shoulder joint will be described. The first results of a complete arthroscopic plate removal from the humeral head will be described. Compared to the open technique, greater satisfaction of the patients, more rapid pain relief and improvement of the shoulder function in the early postoperative time could be observed. During the follow-up interval the results of the two techniques converge.

[Osteoporotic fractures of the proximal humerus]. / Osteoporotische Frakturen am proximalen Humerus.

Fractures of the proximal humerus are typical osteoporotic fractures of the elderly with an increasing incidence. Computed tomography (CT) with 3D reconstruction plays a more and more decisive role in the diagnostics because of an improved understanding of fractures in 3D images. The resulting correct fracture classification has significance for the decision of the best therapy procedure. Currently an extended version of the Codman classification with its four and more fragments is used to give additive information about varus or valgus dislocation, impression or distraction. The comparison of conservative and operative treatment showed no predominance of one of the procedures, therefore both strategies are justified. An operative treatment is recommended in complex fractures. Thus, early functional mobilization, early self-dependence and return to the activities of daily living are possible. Intramedullary nailing is advised in 2-part fractures, in dislocated multipart fractures locking plating or a primary reverse shoulder arthroplasty with refixation of the tuberosities in patients over 75 years. However, the improved plate and nail systems with polyaxiality, calcar screws, modern plate and nails designs as well as the possibility of arthroscopy-assisted nail implantation or plate removal combined with arthroscopic arthrolysis are innovative.

[Comparison of results after primary and secondary shoulder arthroplasty for proximal humeral fractures]. / Ergebnisvergleich primärer versus sekundärer Frakturprothetik am proximalen Humerus.

BACKGROUND: The purpose of this retrospective cohort study was to evaluate, compare and discuss the results and complications after primary and secondary shoulder arthoplasty in proximal humeral fractures. PATIENTS AND METHODS: Thirteen consecutive patients (mean 76 years [range, 65-85] years) were at a mean of 29 (8-37) months after primary humeral head replacement (group 1), and 15 patients (mean 74 years [range, 43-80] years) at a mean of 18 (7-36) months after secondary shoulder arthoplasty (n = 8 anatomic prostheses, n = 7 reversed prostheses) due to complications/fracture sequelae (group 2) examined clinically and radiologically according to a standardised follow-up protocol. Patient satisfaction, the simple shoulder test (SST), the American shoulder elbow score (ASES) as well as the Constant score (CS) were assessed, and radiological parameters as well as complications analysed. RESULTS: 85 % of patients in group 1 and 73 % in group 2 were satisfied with the results. The SST did not show a significant difference between both groups. The adjusted ASES did not differ significantly with 70 (27-95)% in group 1 and 73 (28-100)% in group 2, as well as the adjusted CS with a mean of 53 (27-83)% in group 1 and of 49 (27-87)% in group 2. Radiological analysis resulted in a correctly centred prosthesis in 6/13 patients, and healed tuberosities in 7/13 of group 1. In group 2 4/8 anatomic prostheses were centered and 7/8 showed healed tuberosities. In the subgroup of the reversed prostheses 6/7 were centered, 3/7 patients had an inferior "notching". The rate of complications and revisions were 2/13 (15 %) in group 1 and 1/15 (7 %) in group 2. CONCLUSION: In summary, the functional results did not differ significantly between primary and secondary shoulder arthroplasty after proximal humeral fractures. The relatively low expectation of elderly patients is reflected in a high rate of patient satisfaction in spite of moderate functional results. The primary humeral head replacement showed higher rates of complications and revisions compared to secondary arthroplasty.

[Volar locking plating for distal radial fractures. Is osteoporosis associated with poorer functional results and higher complications rates?]. / Winkelstabile Plattenosteosynthese am distalen Radius. Assoziiert eine Osteoporose schlechtere funktionelle Ergebnisse und höhere Komplikationsraten?

BACKGROUND: The purpose of this prospective study was to compare the functional and radiological results and complication rates after locking plate osteosynthesis of unstable distal radial fractures in elderly patients as a function of the bone mineral density (BMD). The hypothesis that reduced BMD is accompanied by poorer function and a higher rate of complications was investigated. PATIENTS AND METHODS: A total of 65 consecutive patients with unstable distal radial fractures, AO 23-A2 (n=1), -A3 (n=29), -C1 (n=2), -C2 (n=28) and -C3 (n=5) were included with a mean age of 69 years (range, 52-86 years). Standardized clinical and radiological follow-up was performed 6 weeks, 3 and 12 months postoperatively. All patients underwent dual x-ray absorptiometry of the contralateral distal radius within 6 weeks postoperatively and 3 groups could be differentiated: group I (n=27) osteoporosis, group II (n=27) osteopenia and group III (n=11) normal BMD. Data on the DASH and QAL scores as well as the range of motion, grip strength and radiological parameters were collected. According to the BMD a detailed analysis of complications was performed. RESULTS: Exemplary the 12 months results of DASH and the range of motion are shown here: the DASH 12 months postoperatively was DASH(total)=6 (0-64) P, DASH(group I)=7 (0-32.5) P, DASH(group II)=11 (1-63) P, DASH(group III)=2 (0-23) P, no significance. The range of motion increased significantly in all 3 groups (except pronation in groups I and III) from 6 weeks to 3 and 12 months postoperatively and 12 months postoperatively showed means for dorsal extension 55° (25-75), palmar flexion 55° (35-75), ulnar abduction 35° (20-45), radial abduction 20° (5-40), supination 90° (60-90) and pronation 85° (65-90) in the total sample. The comparison of DASH and range of motion was not significantly different at each time of follow-up between all 3 groups. A group-specific analysis of implant and BMD dependent complications showed 2/27 (7%) secondary intra-articular screw perforations in group I, 1/27 (4%) in group II and 0/11 in group III. CONCLUSION: The hypothesis that a reduced BMD is accompanied by a poorer function and a higher rate of complications was refuted. Analysis of complications showed a trend to more BMD-dependent complications in the osteoporosis group.